X 531 Bnnlc LA- ^ CQFmiCHrr deposit. ^ FOOD INSPECTION AND ANALYSIS. FOR THE USE OF PUBLIC ANALYSTS, HEALTH OFFICERS, SANITARY CHEMISTS, AND FOOD ECONOMISTS. ALBERT E. LEACH, S.B., Late Chief of the Denver Food and Drug Inspection Laboratory, Bureau of Chemistry, U. S. Department of Agriculture; Late Chief Analyst of the Massachusetts State Board of Health. REVISED AND ENLARGED BY ANDREW L. WINTON, Ph.D., Chief of the Chicago Food and Drug Inspection Laboratory, Bureau of Chemistry] U. S. Department of Agriculture. THIRD EDITION, FIRST THOUSAND. TOTAL ISSUE, FIVE THOUSAND. NEW YORK: JOHN WILEY & SONS. London: CHAPMAN & HALL, Limited. "^V Copyright, 1904, 1909. BY ALBERT E. LEACH. First Edition Entered at Stationers' Hall. Copyright, 1913. BY Mrs. MARTHA T. LEACH. THE SCIENTIFIC PRESS nOBERI OHUMMOND AND COMPANY * > BROOKLYN, N. Y. (gC!.A332386 ^ Affectionately Dedicated to the Memory of former Analyst of the Massachusetts State Board of Health, whose lovable personality and sterling integrity were a constant inspiration during many years of close companionship to THE AUTHOR. ^ PREFACE TO THIRD EDITION. The period since the appearance of the second edition has been, in America, one of steady progress in food science as compared with the period of special activity, stimulated by federal legislation, immediately preceding and the pioneer period, in which the author was a prominent figure, that led to the pubhcation of the first edition. Without changing the general plan of the work, which ought ever to remain as a monument to the author's remarkable grasp of the subject, new matter equivalent to about 80 pages, not including some 40 pages changed in the last thousand of the second edition, and 12 new cuts, have been added. The size of the work, however, has been increased but 47 pages, as much antiquated matter has been replaced by new, thus per- forming a double service to the reader. Among the new features are improved general methods and apparatus for the determination of moisture, ash, and arsenic, modern apparatus for the Babcock test, processes for the detection of foreign fat in dairy prod- ucts, methods for the determination of ammonia and acidity in meat, and of sugars in cereal products, correction of Munson and Walker's sugar table, new methods for vinegar analysis (including glycerine determina- tion), schemes for the separation of food colors, a subchapter on formic acid (recently introduced as a preservative), methods for the analysis of lemon and orange oils, a summary of analyses of authentic samples of vanilla extract, and a complete revision of the final chapter on fruit and vegetable products with new sections on tomato ketchup, dried fruits, pre- serves (including maraschino cherries), fruit juices, and non-alcoholic car- bonated beverages. In the final chapter are included descriptions of recent methods for the determination of tin, vegetable acids, and habit- forming drugs, and for the detection of saponin, also microscopical methods for the detection of spoilage. The text of the Federal Pure Food Law, as amended during the present year, and of- the Meat Inspection Law, are added for ready reference as an Appendix. Vi PREFACE. The substantial work of Dr. T. B. Osborne in the subchapter on proteins and of Dr. W. D. Bigelow in the chapter on meats, both intro- duced in the second edition, appear unchanged in the present edition, and grateful acknowledgment, previously expressed by the author, is here repeated. The revision has been carried out with the generous assistance of Dr. Kate Barber Winton and of a number of chemists whose methods, duly credited, appear in the text. A. L. W. Chicago, III., November, 191 2. PREFACE TO FIRST EDITION. In the preparation of the present work, the requirements of the public analyst are mainly kept in view, as well as of such officials as naturally cooperate with him in carrying out the provisions of the laws dealing with the suppression of food adulteration in states and municipalities. To this end special prominence is given to the nature and extent of adul- teration in the various foods, to methods of analysis for the detection of adulterants, and to some extent also to the machinery of inspection. While the analyst may not in all cases have directly to deal with the minuticB of food inspection, his work is so closely allied therewith that this branch of the subject is of vital interest and importance to him. Indeed, in many smaller cities one official often has charge of the entire work, combining the duties of both inspector and analyst. Endeavor has been made, furthermore, to deal with the general com- position of foods, and to give such analytical processes as are likely to be needed by the sanitary chemist, or by the student who wishes to determine the proximate components of food materials. It has beer, thought best to include brief synopses of processes of manufacture or preparation of certain foods and food materials, in cases where impurities might be suggested incidental to their preparation. In view of the fact that Massachusetts was the pioneer state to adopt, over twenty years ago, a practical system of food and drug inspection, and for many years was the only state to enjoy such a system, no apology is perhaps needed for more frequent mention of Massachusetts methods and customs than those of many other states, in which the food laws are now being enforced with equal zeal and efficiency. Considerable attention has been paid in the following pages to the use of the microscope in food analysis. Of the figures in the text illus- Viu PREFACE. trating the microscopical structure of powdered tea, coffee, cocoa, and the spices, fifteen have been reproduced from the admirable drawings of Dr. Josef Moeller, of the University of Graz, Austria. Acknowledg- ment is gratefully given Dr. Moeller for his kind consent to their use. The photomicrographs in half-tone, forming the set of plates at the end of the volume, were all made in the author's laboratory, and may be divided into three classes: ist, illustrations of powdered pure foods and food products, as well as of powdered adulterants; 2d, types of adulterated foods, chosen from samples collected from time to time in the routine course of inspection; and 3d, photographs of permanently mounted sections of foods and adulterants. While recent works covering the whole field of general food analysis are comparatively few, the number of treatises, monographs, government bulletins, and articles scattered through the journals, dealing with special subjects relative to food and its inspection, is surprisingly large, and from a painstaking review of these much information has been culled, for which it has been the author's intention at all times to give credit. Special mention should here be made of the valuable publications of the U. S. Department of Agriculture, both the bulletins issued from Washington, and those from the various experiment stations, an ever- increasing number of which are becoming engaged in human food work. The author has freely drawn from these sources, and especially from the data and material furnished by his coworkers in the recent and still pending labor of preparing food methods for the Association of Official Agricultural Chemists, and he wishes to extend his thanks to all of them for their assistance. Appreciation is also expressed for the care and discrimination shown by Mr. L. L. Poates in the preparation of the cuts. Thanks are especially due to Mr. Hermann C. Lythgoe, Assistant Analyst of the Massachusetts State Board of Health, for his invaluable cooperation, and to Dr. Thomas M. Drown for helpful hints and suggestions. Boston, Mass., July i, 1904. TABLE OF CONTENTS. CHAPTER I. Food Analysis and Official Control 1-13 Introductory, i. Food Analysis from the Dietetic Standpoint, 2. Systematic Food Inspection; Functions of the State Analyst; Standards of Purity; Na- ture of Analytical Methods, 3-5. Adulteration of Food, 5. Misbranding, 6. A Typical System of Food Inspection, 6-9. Practical Enforcement of the Food Laws; Publication; Notification; Prosecution, 10. References on Food Inspection and Ofiicial Control, 11. CHAPTER 11. The Laboratory and its Equipment 14-38 Location, 14. Floor; Lighting; Benches, 15. Hoods, 16. Sinks and Drains, 17. Steam and Electricity; Suction and Blast, 19. Apparatus, 20- 25. Reagents, 26-35. Equivalents of Standard Solutions; 36-37. Indica- tors, 38. References on Laboratory Equipment, Reagents, etc., 38. CHAPTER III. Food, its Functions, Proximate Components, and Nutritive Value 39-52 Nature and General Composition of Food; Fats, 39. Protein, and Classification of Nitrogenous Bodies, 40. Proteins, their Subdivisions, Occur- rence, and Characterstic Tests, 40-45. Amino Acids, etc., 45. Alkaloids; Nitrates; Ammonia; Lecithin; Carbohydrates and their Classification, 46. Organic Acids; Mineral or Inorganic Materials; Fuel Value of Food; Bomb Calorimeter, 47-48. References on Dietetics and Economy of Food, 49. CHAPTER IV. General Analytical Methods S3-80 Expression of Results, 53-54. Preparation of Sample, 55. Specific Gravity; Methods and Apparatus, 55-60. Determination of Moisture, 61. Deter- mination of Ash, 62^63. Continuous Extraction with Volatile Solvents, 63-68. Separation with Immiscible Solvents, 68. Determination of Nitrogen, 69-73. X TABLE CF CONTENTS. PAGE Determination of Free Ammonia; Determination of Amide Nitrogen, 74. Determination of Carbohydrates, 74. Poisoned Foods, 74. Detection and Determination of Arsenic, 74-77. Colorometric Analysis, 77. Tintometer, 78. References on General Food Analysis, 79. CHAPTER V. The Microscope in Food Analysis 81-99 Microscopical vs. Chemical Analysis, 81. Technique of Food Microscopy, 82. Apparatus and Accessories, 82-84. Preparation of Vegetable Foods for Microscopical Examination, 85. Miscroscopical Diagnosis, 86. Vegetable Tissues and Cell Contents, under the Microscope, 87-90. Microscopical Reagents, 90-93- Microchemical Reactions, 90-93. Photomicrography; Appurtenances and Methods, 93-98. References on the Microscope in Food Analysis, 98. CHAPTER VI. The Refractometer 100-123 Butyro-refractometer, loi. Refractometer Heater, 102. Manipulation, 102-104. Equivalents of Refractive Indices and Butyro-refractometer Read- ings, 105-106. Temperature Correction, 107. Abbe Refractometer, 108. Construction; Manipulation, 109-111. Immersion Refractometer, 111-112. Manipulation, T13-115. Equivalents of Refractive Indices and Immersion Refractometer Readings, 116-119. Strength of Solutions by Refractometer 120. Temperature Corrections, 121. References on the Refractometer, 122. CHAPTER VII. Milk and Milk Products 124-210 Composition and Characteristics of Milk, 124. Milk Sugar; Milk Proteins, and other Nitrogenous Bodies, 125. Milk Fat; Citric Acid; Composition of the Ash, 126-127. Fore Milk and Strippings, 128. Colostrum; Frozen Milk; Fermentations of Milk, 129. Analysis of Milk, 130. Specific Gravity, 131-133. Total Solids, 132. Ash, 134. Fat, by Extraction, by Centrifugal, and by Re- fractometric Methods, 134-144. Proteins; Casein, 145. Albumin; Other Nitrogenous Bodies, 146. Milk Sugar, by Optical Methods, 147-149, by Fehling's Solution, 149-151. Relation between the Various Milk Constituents; Calculation by Formulae, 151-153. Acidity, 153. Boiled Milk, 155. Modi- fied Milk and its Preparation, 155-157. Prepared Milk Foods, Milk Powders, and Artificial Albuminous Foods, 157-159. Koumis, 158. Kephir, 159. Milk Adulteration and Inspection; Milk Standards, 159-161. Forms of Adulteration, and Variation in Standard, 161-162. Rapid Approximate Methods of Examination, 163-164. ' E.xamination of Milk Serum; Constants, 164-168. Systematic Routine Examination, 168. Analytical Methods for Solids, Fat, and Ash, 170-173. Added Foreign Ingredients, 173. Coloring Matters and their Detection, 174-177. Preservatives, their Relative Efficiency TABLE OF CONTENTS. xi and their Detection, 177-185. Added Cane Sugar, and Starch, 185. Added Condensed Milk; Analysis of Sour Milk, 186. Condensed Milk; Composition, Standards, Adulteration, 186-188. Methods of Analysis, 188-191. Calculation of Fat in Original Milk, 192. Cream; Composition, Standards, Adulterants, Foreign Fat, 193-195. Analyt- ical Methods, 195-198. Ice Cream; Standard, Fillers, 198-199. Analytical Methods, 199-201. Cheese; Composition, Varieties, 202. Standards; Adulteration, 203-204. Anal>1:ical Methods, 204, 205. Separation and Determination of Nitrogenous Bodies, 206, 207. Lactic Acid; Milk Sugar; Foreign Fat, 207. References on IMilk and its Products, 208. CHAPTER VIII. Flesh Foods 211-260 Meat; Structure and Composition, 211. Proximate Components of the Common Meats, 212-217. Meat Inspection, 217. Standards, 218. Meat Preservatives, 218. Curing, 219. Use of Antiseptics; EfTect of Cooking, 220. Canned Meats, 221. Sausages, 223-224. Analytical Methods, 225. Fats of Meats, 226-227. Classification, Separation, and Determination of Nitrog- enous Bodies, 226-231. Determination of Gelatin, 231. Determination of Nitrates, 232. Preservatives and their Detection, 232. Starch in Sausages, 233. Horseflesh in Sausages, and its Detection, 234-238. Muscle Sugar, 238. Coloring Matters and their Detection, 238-239. Detection of Frozen Meat, 239- Meat Extracts; Character and Standards, 240-241. Composition, 242-244. Meat Juices, 245. Miscellaneous Meat Preparations, 246. Methods of Analysis, 246-249. Separation of Nitrogenous Compounds, 249-253. Acidity,- 253. Preservatives; Glycerol, 254. Fish; Struct 're, Composition, and Methods of Analysis, 254-255. Crus- taceans and Mollusks, 256. Floating of Shellfish; Preservatives in Fish and Oysters; Colors, 257. Concentrated Foods for Armies and Campers, 257. References on Flesh Foods, 258. CHAPTER LX. i^GGS 261-270 Nature and Composition, 261. The Egg White and its Nitrogenous Com- pounds, 262. Preparation of Albumin; The Egg Yolk and its Composition, 263. Composition of the Ash, 264. . Analytical Methods; Determination of Lecithin, 265. Preservation of Eggs, 266. Cold Storage Eggs, 267. Physical Methods of Examination, 267. Opened Eggs; Desiccated Eggs, 268. Egg Substitutes, 269. Custard Powders, 270. References on Eggs, 270. Xll T^BLE OF CONTENTS. CHAPTER X. PAGE Cereals and their Products, Legumes, Vegetables, and Fruits 271-364 Composition of Cereals, Vegetables, Fruits, and Nuts, 271-276. Methods of Proximate Analysis, 276-279. Carbohydrates of Cereals, 279. Starch; Detection, Varieties, Classification, Microscopical Examination, 279-283. Starch Determination, by Direct Acid Conversion and by Diastase Methods, 283-284. Sugars, 284-285. Cellulose; Crude Fiber, 285. Pentosans and their Determination, 285-294. Separation and Determination of the Carbohydrates of Cereals, 295-296. Proteins of Cereals and Vegetables; Separation and Methods of Analysis, 296-298. Proteins of Wheat, their Separation and Determination, 298-300. Proteins of Other Cereals and Vegetables, 300-301. Ash of Cereals and Vegetables; Scheme for Ash Analysis, 301-305. Sulphur; Chlorine, 305. Micros- copy of Cereal Products, 306-311. Flour; Milling, 311. Composition, 312. Damaged Flour; Ergot, 313. Adulteration, 314. Alum; Bleaching, 315. Inspection and Analysis; Fine- ness, 316. Color, Absorption, and Dough Tests, 317. Expansion of Dough. 318.' Baking Tests, 317-319. Proximate Constituents; Ash, 319. Gluten; Protein; Acidity, 320. Detection of Bleaching; Nitrites, 321. Bamihl Gluten Test, 322. Bread; Composition; Varieties, 323-325. Methods of Examination, 325- 326. Adulteration of Bread; Alum, 326. Cake, 327. Leavening Materials; Yeast, 327. Compressed Yeast; Dry Yeast, 328. Composition and Microscopical Examination, 329. Yeast Testing; Available Carbon Dioxide, 330. Starch in Compressed Yeast, 331. Chemical Leavening Materials; Baking Powders, their Classification and Composition, 332-334. Adulteration, 334. Cream of Tartar and its Adultera- tion, 335. Analysis of Baking Chemicals, 336. Carbon Dioxide, 336-33Q. Tartaric Acid, 339-343. Starch, 343. Aluminum Salts, 344. Lime; Potash; Soda, 345. Phosphoric Acid; Sulphuric Acid; Ammonia; Arsenic, 346. Semolina, Macaroni, and Edible Pastes; Noodles, 347-348. Adulteration,- Analytical Methods; Lecithin-Phosphoric Acid, 349. Colors, 349-352. Shredded Wheat, 352. Prepared Cereal Breakfast Foods; Nature and Composition, 352-354. Analyt- ical Methods, 354. Infants' and Invalids' Foods, 354. Classification, 355. Composition, 356. Diaberic Foods, 357-358. Analydcal Methods, 359-360. References on Cereals, Vegetables, etc., 361. References on Leavening Materials, 364. CHAPTER XL Tea, Coffee, and Cocoa 365-407 Tea; Varieries, Method of Manufacture, Compositions, 365-368. Analytical Methods, 368. Extract; Tannin, 370-372. Thein, or Caffeine, 372-374- Adul- teradon and Detection of Adulterants; Facing, 374. Spent Leaves, 375. Foreign Leaves; Stems and Fragments, 376. Added Astringents; Tea Tablets, 377. Microscopical Structure, 378. Coffee; Nature, Composition, Effect of Roasting, 379-381. Substitutes and Adulterants, 382. Analytical Methods; Caffetanic Acid, 382-383. TABLE OF CONTENTS. xiii PAGB Caffeine, 384. Adulteration; Imitation Coffee; Coloring, 384. Glazing; Methods, 385. Microscopical Examination, 386. Chicory; its Microscopical Structure, 386-388. Composition of Chicory, and its Determination in Coffee, 389. Date Stones; Hygienic Coffee; Substitutes, 390-392. Cocoa and Cocoa Products; Composition, Methods of Manufacture, 392- 395. Theobromine and Nitrogenous Substances, 396. Milk Chocolate; Com- pounds, 397. Analytical Methods, 398. Starch; Sucrose; Lactose, 399. Theobromine and Caffeine, 400-401. Adulteration, and Standards of Purity, 402. Addition of Alkali, Microscopical Structure, 403-404. Cocoa Shells; Added Starch, Sugar, Fat and Colors, 405. References on Tea, Coffee, and Cocoa, 406. CHAPTER XII. Spices 408-470 Methods of Proximate Analysis Common to all the Spices, 408. Moisture; Ash;' Ether, and Alcohol Extract; Nitrogen; Starch; Crude Fiber; Volatile 0113,409-411. Microscopical Examination, 412. Spice Adulterants, 412-413. Cloves; Composition, 412-415. Tannin, 415. Microscopical Examination, 416. Clove Stems, 417. Adulteration and Standard of Purity; E.xhausted Cloves, 418. Cocoanut Shells, 419. Allspice; Composition, 420. Tannin Equivalent, 421. Microscopical Structure, 422-423. Adulteration and Standard of Purity, 424. Cassia and Cinnamon; Composition, 424-425. Microscopical Structure, 426-427. Adulterants; Standard, 428. Foreign Bark, 428. Pepper; Composition, 428-432. Nitrogen Determination, 432. Piperin, 433. Microscopical Examination, 433-434. Adulteration and Standards, 435. Pepper Shells and Dust, 435. Olive Stones, 436. Buckwheat, 437. Long Pepper, 438. Red Pepper; (Cayenne, Paprika, etc.). Nature; Varieties: Composition, 439-441; Microscopical Structure, 441-443. Adulteration, 443-445. Added Oil in Paprika, 445. Ginger; Composition, 445-446. Exhausted Ginger, and its Detection, 447- 448. Microscopical Structure, 449. Adulteration and Standard, 450. Turmeric; Composition, 450. Microscopical Structure, 451. Detection, 443- Mustard; Composition, Preparation, 453-456. Mustard Oil Determina- tion, 457. Microscopical Structure, 458. Adulteration and Standards; Charlock, 459-460. Coloring Matter, 460. Prepared Mustard; Composition, Adulteration, 460. Analytical Methods, 461. Nutmeg and Mace; Composition of Nutmeg, 462-463. Microscopical Struc- ture of Nutmeg; Adulteration; Standard of Purity, 464. Composition of Mace, 465. Microscopical Structure; Adulteration; Standard, 466. Bombay or Wild Mace and its Detection, 467. Macassar Mace, 468. References on Spices, 468. XIV TABLE OF CONTENTS. CHAPTER XIII. PAGB Edible Oils and Fats 471-564 Nature and Properties, 471. Fatty Acids, 471-472. Saponification, 472. Analysis; Rancidity; Judgment as to Purity; Filtering, Weighing, and Measuring Fats, 473. Specific Gravity, 474-476. Viscosity, 477. Melting- point, 480. Reichert-Meissl Process for Volatile Fatty Acids, 481-482. Po- lenske Number, 483. Soluble and Insoluble Fatty Acids, 484-486. Saponifica- tion Number, 486. Iodine Absorption Number; Hiibl's Method, 487-490. Hanus's Method, 491. Wijs's Method, 492. Bromine Apsorption Number, 492-493. Thermal Tests, 493. Maumene Test, 494. Bromination Test, 494- 497. The Acetyl Value, 497-498. The Valenta and Elaidin Tests, 499. Free Fatty Acids, 500. Titer Test, 500-501. Unsaponifiable Matter, 501. Cholesterol and Phytosterol, 502. Separation and Crystallization, 503-506. Bomer's Phytosterol Acetate Test, 507. Constants of Edible Oils and Fats, 508-509. Parraffin; Microscopical Examinaltion of Oils and Fats, 510. Olive Oil, 511. Composition and Adulteration, 512. Standards, 513. Tests for Adulteration, 513-515. Cottonseed Oil, 516. Bechi's Test, 517. Hal- phen's Test, 518. Sesame Oil, 518. Adulterants and Tests, 519. Rape Oil, 520. Tests, 521. Corn Oil, 521. Sitosterol, 522. Peanut Oil, 522. Adul- terants; Renard's Method, 523. Bellier's Method, 524. Mustard Oil, 525. Poppyseed Oil, 526. Sunflower Oil, 526. Rosin Oil, 527. Cocoanut Oil, 528. Cocoa Butter; Tallow^, 529. Butter, 529. Composition, 530. Effects of Feeding, 531. Analytical Methods, 531. Water, 531-533. Fat, 533. Ash; Casein; Milk Sugar; Lactic Acid; Salt, 534. Standard Butter Fat, 535. Adulteration, 535. Colors, 535-537. Preservatives, 538-539. Renovated or Process Butter, 540. Oleomargarine; Manufacture, 541. Coloring; Detection of Palm Oil, 542. Adulterants; Healthfulness, 543. Distinction from Butter, 544. Distin- guishing Tests for Butter, Process Butter, and Oleomargarine, 546. Butyro- refractometer, 546-548. Reichert-Meissl Number; Specific Gravity; Foam Test, 549. Milk Test, 550. Curd Tests, 551. Microscopical Examination, 552-553- Foreign Oils, 554. Lard, 554. Composition; Lard Oil, 555. Compound Lard; Standards; Adulteration, 556. Foreign Oils, 557. Microscopical Examination, 557-558. Analysis of Lard and Lard Substitutes, 559. Effects of Feeding, 560. References on Edible Oils and Fats, 561. References on Butter, 562. Refer- ences on Lard, 563. CHAPTER XIV. Sugar and Saccharine Products 565-652 Nature and Classification, 565. Cane Sugar; Standard, 566. Sugar Cane; Manufacture of Cane Sugar, 567. Composition of Cane Sugar Products, 568. Sugar Beet; Manufacture of Beet Sugar, 569. Refining Sugar; Maple Pro- ducts, 750. Compositions, Standards, and Adulteration of Maple Products, 571-572. Sorghum, 573. Grape Sugar, 573. Levulose; Malt Sugar, 574. Dextrin; Commercial Glucose, 575. Standards and Healthfulness of Glucose, 576. Milk Sugar; Raffinose, 577. TABLE OF CONTENTS. XV PAGB The Polariscope and Saccharimetry. 578-583. Comparison of Scales and Normal Weights, 583. Specific Rotary Power; Birotation, 584. Analysis of Cane Sugar and its Products; Tests for Sucrose, 585. Moisture; Ash; Non-sugars; Sucrose Determination by Polariscope, 586-587. Inversion; Clerget's Formula, 588. Detection and Determination of Invert Sugar, 589. Ultramarine in Sugar; Copper Reduction, 590. Volumetric Fehling Process, 591-592. Gravimetric Fehling Methods, 593. Defren-O'SuUivan Method, 594-597. Munson and Walker Method, 598-607. Allihn Method; Elec- trolytic Apparatus 608-612. Sucrose Determination by Fehling Solution, 612. Analysis of Molasses and Syrups, 613. Solids; Ash; Polarization, 613- 620. Double Dilution Method of Polarizing; Rafiinose Determination, 620. Adulteration of Molasses and Standards, 621. Glucose Determination, 621- 624. Ashing Saccharine Products, 624. Tin Determination, 625. Separation and Determination of Various Sugars, 625-626. Analysis of Maple Products, 627. Moisture; Ash; Malic Acid Value, 627. Lead Number, 628. Hortvet Number, 628-630. Sy's Method, 630. Analysis of Glucose; Polarization Formulae, 630-631. Dextrin; Ash; Sulphurous Acid, 632. Arsenic, 633. Honey; European, 633. Canadian; American; Hawaiian, 634-635. Adulteration, 636-638. Analysis of Honey; Moisture; Ash; Polarization, 639. Reducing Sugars; Levulose; Dextrose; Sucrose; Dextrin, 640. Acids; Glucose, 641. Invert Sugar; Distinction of Honeydew from Glucose, 642. Confectionery; Standard; Adulteration; Colors, 645. Analysis of Con- fectionery; Mineral Adulterants, 646. Ether Extract; Paraffine, 647. Starch; Polarization, 648. Alcohol; Colors; Arsenic, 649. References on Sugars, 650. CHAPTER XV. Alcoholic Beverages 653-758 Alcoholic Fermentation, 653. Alcoholic Liquors and State Control, 654. Liquor Inspection, 655-656. Analytical Methods common to all Liquors; Specific Gravity, 657. Detection and Determination of Alcohol, 657-660. Alcohol Tables, 661-674. The Ebulioscope, 675-676. Extract; Ash; Arti- ficial Sweeteners, 677. Fermented Liquors; Cider, 678. Manufacture and Composition, 678-681. Adulteration, 682. Perry, 683. Wine, 684. Classification of Wines, 685. Composition and Varieties, 686-689. Standards, 689-691. Adulteration, 691-695. Analytical Methods for Wine; Extract; Acidity, 696. Extract Table, 697-699. Tartaric Acid, 701. Malic Acid, 702. Sugars; Glycerin, 703. Tannin, 704. Foreign Colors, 704-706. Malt Liquors; Beer, 707. Varieties of Beer and Ale, 708. Composition, 709. Malt and Hop Substitutes, 710. Adulteration and Standards, 711. Malted vs. Non-malted Liquors, 712. Preservatives; Arsenic, 713. Tem- perance Beers, 714. Analytical Methods, 714. Alcohol, 715. Extract, 715- 722. Original Gravity, 722-724. Sugars; Dextrin; Glycerine; Acids, 724. Protein; Phosphoric Acid, 725. Carbon Dioxide, 726. Bitter Principles, 726- 727. Arsenic, 728. Malt Extract, 729. XVI TABLE OF CONTENTS. PAGE Distilled Liquors; Standards for Spirits, 730. Fusel Oil, 731. Whiskey, 731. Manufacture, 731-732. Standards, 733-734. Composition, 734-737. Adultera- tion, 738. Brandy; Manufacture; Composition, 739. Standards, 740. Adul- teration, 741. Rum; Composition, 742. Standards, 742-743. Gin; Composi- tion, 744. Analytical Methods for Distilled Liquors; Extract; Acids; Esters; Aldehydes, 745. Furfural, 746. Fusel Oil, 746-749. Methyl Alcohol, 749-752. Caramel, 752-753. Opalescence Test, 753. Liqueurs and Cordials, 754. Analysis of Liqueurs, 755. References on Alcoholic Beverages; on Beer, 756. References on Cider and Wine, 757; on Distilled Liquors, 758. CHAPTER XVI. Vinegar 759-781 Acetic Fermentation; Varieties of Vinegar, 759. Manufacture and Compo- sition, 760-761. Cider Vinegar, 760. Wine Vinegar, 761. Malt Vinegar, 762. Spirit, Glucose, and Molasses Vinegars, 763. Wood Vinegar, 764. Analytical Methods; Density; Extract; Ash; Phosphoric Acid, 764. Nitrogen; Acidity, 765. Alcohol; Mineral Acids, 766. Malic Acid, 767. Lead Precipitate, 768. Potassium Tartrate; Sugars, 769. Pentosans, 770. Glycerine, 770-772. Adulteration of Vinegar; Standards, 772-773. Artificial Cider Vinegar, 774. Character of Residue and Ash, 774-775. Character of Sugars, 776. Tests, 777. Composition of Artificial Cider Vinegars, 778. Detection of Adulterants, and Mineral Impurities, 779-780. References on Vinegar, 780. CHAPTER XVII. Artificial Food Colors 782-820 Extent of Use; Objectionable Features, 782. Toxic Effects, 783. Harmful Mineral Colors, 784. Harmful Organic Colors, 785. Harmless Mineral Colors; Harmless Organic Colors, 786-788. Use of Colors in Confectionery, 788. Vegetable Colors, 789-791. Special Tests; Orchil; Logwood; Turmeric, 791. Caramel; Indigo, 792. Cochineal, 792. Mineral Pigments; Prussian Blue, 792. Ultramarine; Lead Chromate, 793. Coal-tar Colors, 793. Allowed Colors, 794. Detection in Food;'. Basic and Acid Dyes; Wool Dyeing, 795. Double Dyeing Method, 796. Vegetable Colors on Wool; Extraction of Colors by Immiscible Solvents, 797. Separation with Ether, 798. Special Tests, 799. Classification and Identification of Coal-tar Dyes; Rota's Scheme, 799-804. Direct Identification of Colors, 805. Table of Reactions for Colors on the Fiber, 806-813. Reagents, 814. Separation and Identification of Allowed and Acid Colors, 814. Price's Scheme, 815. Mathewson's Tables, 816-8180 Analysis of Colors, 818. Solubility Tables, 818. References on Colors, 819. CHAPTER XVIII. Food Preservatives 821-849 Preservation of Food, 821. Regulation of Antiseptics, 822. Commercial Food Preservatives, 823. Formaldehyde, 824. Determination in Preservatives, 825. Detection in Food, 826. Determination, 827. Boric Acid; Determination in TABLE OF CONTENTS. xvil Preservatives, 827. Detection in Foods, 828. Determination, 829-830. Salicylic Acid;. Detection, 831. Determination, 832. Benzoic Acid, 833. Detection, 834- 835. Determination, 835-839. Sulphurous Acid, 839. Detection; Determina- tion, 840. Formic Acid; Detection, 841. Determination, 842. Fluorides, Fluo- silicates, Fluoborates, S43-844. Beta-Napthhol; Detection, 845. Asaprol or Abrastol, 845. Detection, 846. References on Preservatives and their Use in Food, 846. CHAPTER XIX. Artificial Sweeteners 850-856 Extent of Use; Saccharin, 850. Detection of Saccharin, 851. Determination, 852. Dulcin; Detection, 853. Determination of Dulcin, 854. Glucin, 855. References on Artificial Sweeteners, 855. CHAPTER XX. Flavoring- Extracts and their Substitutes 857- Vanilla Extract. 857. Vanilla Bean, 857. Composition, 858. Vanillin; Exhausted Vanilla Bean, 859. Composition of Vanilla Extract, 859-861. Tonka Bean, 860. Coumarin; Standards; Adulteration of Vanilla Extract, 862. Arti- ficial Extracts, 863. Detection of Artificial Extracts, 864. Determination of Vanillin and Coumarin, 865-867. Tests for Coumarin; Vanillin and Coumarin under the Microscope; Normal Lead Number, 867. Acetanilide, 868. Glycerin; Alcohol; Caramel, 869. Limits; Colors, 870. Lemon Extract, 870. Standards, 870. Adulteration, 871. Analytical Methods; Determination of Lemon Oil, 872-875. Alcohol; Total Aldehydes. 875. Citral, 877. Methyl Alcohol; Colors, 878. Solids; Ash; Glycerin; Examination of Lemon Oil, 879. Constants of Lemon and other Oils, 880. Citral, Citronellal, and other Adulterants, 881. Lemon Oil; Analytical Methods; Density; Refrac- tion; Rotation; Citral, 882. Aldehydes; Physical Constants; Pinene; Alcohol, 883. Orange Extract, 884. Almond Extract, 884. Benzaldehyde; Standard, 885. Adulteration; Analytical Methods; Determination of Benzaldehyde, 886. Nitro- benzol, 887. Distinction and Separation from Benzaldehyde; Artificial Benzal- dehyde; Alcohol; Hydrocyanic Acid, 888. Wintergreen Extract; Standards, 889. Adulteration; Determination of Wintergreen Oil; Peppermint Extract; Pepper- mint Oil, 890. Standards; Analytical Methods; Spearmint Extract, 891. Spice Extracts; Standards, 892. Analytical Methods, 893-894. Rose Extract; Stand- ards; Determination of Rose Oil, 895. Imitation Fruit Flavors, 895-897. Deter- mination of Esters, 898. References on Flavoring Extracts, 898. CHAPTER XXI, Vegetable and Fruit Products 900-964 Canned Vegetables and Fruits; Method of Canning, 900-901. Composition, 902. Decomposition and Detection of Spoiled Cans, 902. Gases from Spoiled , Xviii TABLE OF CONTENTS. Cans, 903. Metallic Impurities, 904. Action of Fruit Acids on Tin Plate, 905- 908. Salts of Lead, 908. Salts of Zinc and Copper, 909-910. Salts of Nickel; Toxic Effects of Metallic Salts, 911. Preservatives; Soaked Goods, 912. Analyt- ical Methods; Proximate Analysis; Lead in Tin Alloy, 913. Tin, Copper, Lead, Zinc, and Nickel, 914-919. Ketchup, 919. Standards; Process of Manufacture, 919. Composition; Decayed Material; Refuse, 920. Foreign Pulp; Preservatives; Colors; Analytical Methods; Solids, 921. Sand; Sugars, 922. Citric and Lactic Acids, 923. Micro- scopic Examination, 924-925. Pickles, 925-926. Adulteration, 926. Horseradish, 927. Preserv^es, 927. Fruit Butter; Mince Meat, 927-928. Pie EilHng; Maraschino Cherries, 928-929. Jams and Jellies, 930. Composition; Adulteration, 931-934. Compounds; Imitations, 936. Analytical Methods; Solids, 936. Ash; Acidity; Protein, 937, Sugars, 938-940. Glucose; Dextrin, 940. Alcohol Precipitate; Organic Acids, 941. Citric Acid; Colors; Preservatives; Sweeteners, 942. Starch; Gelatin; Agar-agar; Apple Pulp, 943. Fruit Tissues, 944. Dried Fruits, 944. Lye Treatment; Sulphuring; Moisture; Spoilage, 945. Zinc; Analytical Methods, 946. Fruit Juices, 946-947. Grape Juice, 947. Sweet Cider; Lime Juice, 948. Analytical Methods; Acidity; Tartaric and Malic Acids, 949-950. Citric Acid, 951. Fruit Syrups, 952. , Non-Alcoholic Carbonated Beverages, 952. Soda Water, 952-953. Syrups, 953. Bottled Beverages; Sweeteners, 954. Acids; Preservatives; Colors; Foam Pro- ducers; Habit-forming Drugs, 955. Analytical Methods; Solids; Ash; Acids; Sugars; Flavors; Colors; Preservatives; Sweeteners; Alcohol, 956. Saponin, 956-958. Caffein; Cocaine, 958-961. References on Vegetable and Fruit Products, 961. APPENDIX. The Food and Drugs Act, 965. The Meat Inspection Law, 969. TABLE OF CON TENTS J XIX PLATES I-XL. Photomicrographs of Pure and Adulterated Foods and of Adulterants. Cereals: Barley, I. Buckwheat, II, III. Corn, III, IV. Oat, IV, V. Rice, V, VI. Rye, VI, VII. Wheat, VIII. Legumes: Bean, IX. Lentil, IX, X. Pea, X, XL Miscellaneous Starches: Potato; Arrowroot; Tapioca, XII. Turmeric; Sago, XIII. Coffee, XIV, XV. Chicory, XV, XVI. Cocoa, XVI, XVII. Tea, XVIII. Spices: Allspice, XVIII, XIX. Cassia, Cinnamon, XX-XXII. Cayenne, XXII- XXIV. Cloves; Clove Stems, XXIV-XXVII. Ginger, XXVII-XXIX. Mace, XXIX. Nutmeg, XXX. Mustard, XXXI-XXXIII. Pepper, XXXIII-XXXVI. Spice Adulterants: Olive Stones; Cocoanut Shells, XXXVI. Elm Bark; Sawdust; Pine Wood, XXXVII. Edible Fats: Pure Butter; Renovated Butter; Oleomargarine, XXXVIII. Lard Stearin, XXXIX. Beef Stearin, XL, FOOD INSPECTION AND ANALYSIS. CHAPTER I. FOOD ANALYSIS AND OFFICIAL CONTROL. INTRODUCTORY. The general subject of food analysis, in so far as the public health is concerned, is to be considered from two somewhat different standpoints: first, from the outlook of the government, state, or municipal analyst, whose mission it is to ascertain whether or not the food may properly be con- sidered pure or free from adulteration; and second, from the point of view of the food economist, whose aim is to determine its actual composition, and nutritive value. The one protects against fraud and injury, the other furnishes data for the arrangement of dietaries and for an intelligent conception of the role which the various nutrients play in the metabolism •of matter and energy in the body. The two fields are as a rule distinct each from the other, often involving, in the examination of the food, different methods of procedure. Official Control of Food. — In view of the importance of the consideration of food with reference to its purity, an ever-increasing number of states have realized the necessity of protecting their citizens from the unscrupu- lous manufacturers who in various lines are seeking to produce cheaper or inferior articles of food in close imitation of pure goods. Many of the states have laws in accordance with which the sale of such impure or adulterated foods is made a criminal offense, and some, but not all of these, are provided with public analysts and other officers to enforce these laws and punish the offenders. Numerous communities are awake to the importance of municipal control of such commonly used articles of food as milk, butter, and vinegar, and in many cases have machinery of their own for rcgulatino; the sale of these foods. 2 FOOD INSPECTION AND ANALYSIS. Since January i, 1907, the federal government has been actively en- gaged in the enforcement of the national food law of June 30, 1906, through the Bureau of Chemistry of the U. S. Department of Agriculture. In addition to the central laboratories of this Bureau at Washington, upw^ards of 20 branch laboratories have been established in the principal cities of the United States to enforce the provisions of the national lav^ which regu- lates interstate commerce in foods, as well as their manufacture and sale in the territories and the District of Columbia, and their importation from foreign countries. Food Analysis from the Dietetic Standpoint. — The study of the prin- ciples of dietetics has been given increased attention during the last decade in the curricula of many of the technical schools and colleges. Much has been accomplished by certain of the state experiment stations working as a rule in connection with the United States Department of Agriculture along this line. Investigations of this character are especially valuable, and are indeed rendered necessary by the general tendency of the modern physician to regard the hygienic treatment of disease, especially with reference to the matter of diet, as often of far greater importance than the mere administering of drugs. The food economist studies the varying conditions of age, sex, occupa- tion, environment, and health among his fellow men, with a view to show- ing what foods are best adapted to supply the special requirements of various classes. The quantity and proportion of protein, fat and carbo- hydrates, or of fuel value best suited for the daily consumption of a given class or individual having been determined, dietaries are made up from various food materials to supply the need with reference as far as possible to the taste and means of the consumer. Experiments are made on families, clubs, or individuals, representing various typical conditions of life, and extending over a given period, dur- ing which records are kept of the available food materials on hand and received during the term of the experiment, as well as of those remaining at the end. In the case of individuals, additional records may be kept of the amount and composition of the urine and feces. From such data the physiological chemist calculates the amount of nutrients utihzed, and studies the metabolism of material in the human body. Up to this point no very extensive apparatus is required, but if in addition the income and outgo of heat and energy are to be studied, which are important to a complete investigation of the economy of food in the body, the student will require a respiration calorimeter and its appurte- FOOD ANAL YSIS AND OFFICIAL CONTROL. 3 nances. The calorimeter is so constructed that an individual may be confined therein for a term of days under close observation and with carefully regulated conditions. Such an equipment involves a large expenditure and is to be found in but few laboratories. It is not the purpose of the present work to go beyond the strictly chemical or physical processes involved in making the analyses by which the proximate components of the foods are determined. For more com- plete information in the field of dietary studies and the metabolism of matter and energy in the body, the student is referred especially to the investigations of Atwater and his coworkers, as pubhshed in the annual reports of the Storrs Experiment Station at Middletown, and in the bulle- tins of the U. S. Department of Agriculture, Office of Experiment Stations, a list of which is given at the end of Chapter III. Commercial Food Analysis. — The proper preparation of food products has long ceased to be carried on by the hap-hazard rule-of-thumb methods that formerly prevailed. Now in the manufacture of many prepared foods and condiments, especially on a large scale, it has become a necessity to use scientific processes, rendered possible only by the employment of skilled chemists. In fact it is coming to be more and more common for food manufacturers to establish chemical laboratories in connection with their works, in the interests both of economy and of improved production. Frequently disputed points arise in the enforcement of the food laws that render the services of the private food analyst of great importance both to manufacturer and dealer. Thus a wide field is open to the analyst of foods outside the domain of the government or state laboratory, either in connection with the large food manufacturing plants directly, or m private laboratories for experimental research, or for analytical control work. SYSTEMATIC FOOD INSPECTION. Functions of the Official Analyst. — The public analyst is employed by city, state, or government to pass judgment on various articles of food taken from the open market by purchase or seizure, either by himself or by duly authorized collectors employed for the purpose. The sole object of his examination is to ascertain whether or not such articles of food con- form to certain standards of purity fixed in some cases by special law, and in others by common usage or acceptance. Such a public analyst need not concern himself with the dietetic value of the food or whether it is of high or low grade. It is for him to determine simply whether it is genuine or 4 FOOD INSPECTION AND ANALYSIS. adulterated within the meaning of the law, and, if adulterated, how and to what extent. Aside from his skill as a chemist, it is often necessary for him to possess other no less important qualifications, chief among which are his ability to testify clearly and concisely in the courts, and to meet at any time the most rigid kind of cross-examination, it being of the utmost importance that he understand thoroughly the nature of evidence. Standards of Purity for Food Products.* — Under an act of Congress approved Alarch 3, 1903, standards of purity for certain articles of food have been established as official standards for the United States by the Secretary of Agriculture. The earlier of these standards were formulated under the Secretary's direction by a committee of the Association of Official Agricultural Chemists. Later, however, a joint committee of that asso- ciation and of the Association of State and National Food and Dairy Departments has had charge of this work. Standards have been and are being thus adopted, covering the entire range of food products. r Nature of the Analytical Methods Employed. — Usually but a small percentage of the samples submitted for examination are actually adulter- ated. The analyst should, therefore, adopt for economy in time the quickest possible reliable processes for separating the pure from the impure, so that most of his attention may be devoted to the latter. The nature of the processes by which this is done varies with the foods. Experience soon enables one to judge much by even, the characteristics of taste, appearance, and odor, though such superficial indications should be used with discretion. One or two simple chemical or physical tests may often suffice to establish beyond a doubt the purity of the sample, after which no further attention need be paid to it. A sample failing to conform to the tests of a genuine food must be carefully examined in detail for impurities or adulterants. While in most cases usage or experience suggests the forms of adulteration peculiar to various foods, the analyst should be on the alert to meet new conditions constantly arising. His methods are largely qualitative, since technically he need only show in most cases the mere presence of a forbidden ingredient, though for the analyst's own satisfaction he had best deter- mine the amount, at least approximately. In reporting approximate quantitative results in court, especially when they are calculated from assumed or variable factors, or when they are the result of judgment based on the appearance of the food under * U. S. Dept. of Agric, 0£F. of Sec, Circ. 19. FOOD ANALYSIS AND OFFICIAL CONTROL. 5 the microscope, the analyst should always be conservative in his figures by expressing the lowest or minimum amount of the adulterant, so as to give the defendant the benefit of any doubt. When exact standards are fixed by law, as in the case of total soli Js or fat in milk, for example, there is of course great necessity for preciseness in quantitative work. A full analysis of an adulterated food beyond establishing tlie nature and amount of the adulteration is entirely unnecessary, and in most instances adds nothing to the strength of a contested case, as twenty years' experience in the enforcement of the food laws in Massachusetts has shown. The responsibility resting upon the analyst is not to be lightly con- sidered, when it is realized that his judgment and findings constitute the basis on which court complaints are made, and the payment of a fine or even the imprisonment of the defendant may be the result of his report. Therefore he should be sure of his ground, knowing that his results are open to question by the defendant. Where court procedure is apt to be involved, a safe rule is for the analyst to consider himself the hardest person to convince that his tests are unquestionable, making every possible confirmatory test to strengthen his position and consulting all available authorities before expressing his opinion; and finally, after being fully convinced that a sample is adulterated, and having so alleged, let him adhere to his statements and not waver in spite of the most rigid cross- examination to which he may be subjected. While each state or municipality has its own peculiar code of regula- . tions and restrictions concerning the duties of the analyst and other officials, these rules are in the main very similar. For instance, it is usually neces- sary, excepting in the case of such a perishable food as milk, for the analyst to reserve a portion of a sample before beginning the analysis, which sample, in the event of proving to be adulterated, shall be sealed, so that in case a complaint is made against the vendor, the sealed sample may, on application, be dehvered to the defendant or his attorney. Adulteration of Food. — Except in special cases a food in general is deemed to be adulterated if anything has been mixed with it to reduce or lower its quality or strength; or if anything inferior or cheaper has been substituted wholly or in part therefor; or if any valuable constituent has been abstracted wholly or in part from it ; or if it consists wholly or in part of a diseased, decomposed, or putrid animal or vegetable sub- stance; or if by coloring, coating, or otherwise it is made to appear of greater value than it really is; or if it contains any added poisonous 6 FOOD INSPECTION AND ANALYSIS. ingredient. These provisions briefly expressed are typical of the general food laws adopted by most states and by the government, though the verbiage may differ. Laws covering compound foods and special foods var)' widely with the locality. As to the character of adulteration, nine out of ten adulterated foods are so classed by reason of the addition of cheaper though harmless ingredients added for commercial profit, rather than by the addition of actually poisonous or injurious substances, though occasional instances of the latter are found. Authentic instances of actual danger to health from the presence of injurious ingredients are extremely rare, so that the question of food adulteration should logically be met largely on the ground of its fraudu- lent character. Indeed the commoner forms of adulteration are restricted to a comparatively small number of food products, the most staple articles of our food supply, such as sugar and the cereals, eggs, fresh meat, fresh vegetables and fruit being rarely subject to adulteration. Misbranding. — Under the federal food law and the laws of many of the states misbranding constitutes an offense as well as adulteration. By misbranding is meant any untrue or deceptive statement or design on the label of a food package, either regarding the nature of the contents, or of the place of manufacture or name of manufacturer. One of the com- monest forms of misbranding consists in the incorrect statement of weight or measure. Extravagant and untrue claims as to nutritive value have hitherto constituted a frequent form of misbranding. A Typical System of Food Inspection. — The efficiency of a system of public food inspection is greatly enhanced if the business part of the work, including the bookkeeping and attending to the outside public, be done wholly through some person other than the analyst, as, for example, a health officer, to whom the collectors of samples and the analyst may report independently as to the results of their work, and whose duty it is to determine what shall be done in cases of adulteration. In this way the analyst knows nothing of the data of collection nor the name of the person from whom the sample was purchased, so that he can truthfully state in court that his analysis was un- biased. Suppose, for example, that three collectors are employed to purchase samples of food for analysis, their duties being to visit at irregular intervals different portions of a state or municipality. Each collector keeps a book in which he enters all data as to the collection of the sample, includ- FOOD AN/iLYSIS AND OFFICIAL CONTROL. Fig. I. — Inspectors' Lockers. Insuring safe legal delivery of samples collected by tiire& inspectors. Each locker has a door in the rear accessible, from an anteroom, to the in« specter holding key to that locker only. FOOD INSPECTION AND AN A LYSIS. Fig. 2. — ^Inspectors' Lockers. Front View. The lockers are accessible to the analyst in the laboratory by a single sliding-sash front, provided with a spring lock. The removable sliding-racks are convenient for returning clean sample bottles. FOOD ANALYSIS AND OFFICIAL CONTROL. 9 ing the name of the vendor, assigning a number to each sample, which number is the only distinguishing mark for the analyst. One collector may use for this purpose the odd numbers in . succession from i to 9999, the second the even numbers from 2 to 10,000, while the third may use the numbers from 10,000 up. Each of the two former would begin with a lettered series, as, for instance, A, numbering his samples i A, 3A, 5A, 7A, etc., or 2A, 4A, 6A, etc., till he reached 10,000, then beginning on series B and so on. If the analyst is to be kept in ignorance of the brand or manufacturer in the case of package goods, the collector must remove from the original package sufficient of the sample for the needs of the analyst, and deliver it to the latter in a plain package, bearing simply the name under which the article was sold and the number. Such precau- tions are, however, not always practicable and depend largely on local regulations. The analyst reports the result of the analysis of each sample with the number thereof on a librar)^ card, with appropriate blanks both for data of analysis and for data of collection, the latter to be filled by the collector from his book after the analyst has handed in the card with the data of analysis. This system of recording and reporting analyses has been successfully used for years by the Department of Food and Drug Inspection of the Massachusetts State Board of Health. Legal Precautions. — The laboratory of the public analyst should preferably be provided with a locker for each collector, to which access may be had only by that collector and the analyst, so that in the absence of the latter, or when circumstances are such that the samples cannot be delivered to him personally, there may be such safeguards with respect to lock and key as to leave no question in the courts as to safe deUvery and freedom from accidental tampering. With such a system it is un- necessary for the collector to place under seal the various samples sub- mitted for analysis. Unless such lockers or their equivalent are employed, it is best to carefully seal all samples. Such a system of lockers for use with three collectors is shown in Figs. I and 2. The same careful attention should afterwards be given to keep the specimens in a secure place both before and during the process of analysis, and to label with care all precipitates, filtrates, and solutions having to do with the samples, especially when several processes are being simultaneously conducted, in order that there may be no doubt whatever as to their identity. The importance of precautions of this kind in connection with court work can hardly be too strongly emphasized. lo FOOD INSPECTION AND /ANALYSIS. Practical Enforcement of the Food Law. — In the case of foods actually found adulterated, there are three practical methods of suppressing their further sale, viz., by publication, by notification, and by prosecution. These may be separately employed or used in connection with each other, accord- ing to the powers conferred by law on the commission, board, or official having in charge the enforcement of the law, and according to the dis- cretion of such official. Publication. — Under the laws of some states, the only means of pro- tecting the people lies in pubhshing lists of adulterated foods with their brands and manufacturers' names and addresses in periodical bulletins or reports. Sometimes it is considered best to publish for the informa- tion of the pubhc lists of unadulterated brands as well, and, again, it is held that only the offenders should thus be advertised. Such pubhcation, by keeping the trade informed of the blacklisted brands and manufacturers, certainly has a decidedly beneficial effect in reducing adulteration, and involves less trouble and expense than any other method. It is obviously an advantage, however, in addition to this to be able in certain extreme cases to use more stringent methods when necessary. Notification and Prosecution. — The adulteration of food is best held in check in locahties where under the law cases may be brought in court and are occasionally so brought. The mere power to prosecute is in itself a safeguard, even though that power is not frequently exercised. Under a conservative enforcement of the law, actual prosecution should be made as a last resort. Neither the number of court cases brought by a food commission nor the large ratio of court cases to samples found adulterated are criteria of its good work. Except in extreme cases, it is frequently found far more effective to notify a violator of the law, especially if it is a first offense, giving warning that subsequent infraction will be followed by prosecution. Such a notification frequently serves to stop all further trouble at once and with the minimum of expense. Instances are frequent in Massachusetts where, by such simple notifica- tion, widely distributed brands of adulterated foods have been immediately withdrawn from sale. Massachusetts was the first of all the states to enact pure-food legisla- tion, and since the year 1883 has had a well-established system of inspection, prosecuting cases under its laws through the Food and Drug Department of the State Board of Health. Cases are brought in court with practically no expense for legal services. Complaints are entered by FOOD ^Nyl LYSIS AND OFFICIAL CONTROL. II the collector, or, as he is termed, inspector, who makes complaint not in his official capacity, but as a citizen who under the law has been sold a food found to be adulterated, and who is entitled to conduct his own case, whicti he does with the aid of the analyst and such other witnesses as he may see fit to employ. Experience is readily acquired by the inspector in conducting such cases in the lower police or municipal courts, where they are first tried, and years ago the services of legal counsel in Massa chusetts were dispensed with as superfluous.* Statistics in the annual reports of the Massachusetts Board show with what uniform success these trials have been conducted. \^liile more often settled in the lower courts, occasional appeal cases are carried tc the superior courts, where the services of the regular district attornej^ are of course availed of in prosecuting the case. Such a system as the above, while admirable for a state or city after long experience in the enforcement of food laws in the courts, is obviously impracticable with newly established systems of state food inspection. REFERENCES ON FOOD INSPECTION AND OFFICIAL CONTROL. Abbott, S. W. Food and Drug Inspection. Article in Reference Handbook of the Medical Sciences, Vol. 3, pp. 162-180. N. Y., 1902. Andrews, O. W. Public Health Laboratory Work and Food Inspection. London, 1901. BiGELOW, W. D. Foods and Food Control. U. S. Dept. of Agric, Bur. of Chem., Bui. 69, rev. Food Legislation for the Year Ending June 30, 1907. Ibid., Bui. 112. Pure Food Laws of European Countries. U. S. Dept. of Agric, Bur. of Chem., Bui. 61. BucHKA, K. VON. Die Nahrungsmittelgesetzgebung im Deutschen Reiche. Berlin, 1901. Chapin, C. V. Municipal Sanitation in the United States. Providence. Kenwood, H. R. Public Health Laboratory Work. London, 1904. Leach, A. E. Character and Extent of Food and Drug Adulteration in Massachu- setts and the System of Inspection of the State Board of Health. Tech. Quar- terly, March, 1900. Moor, C. D. Suggested Standards of Purity for Foods and Drugs. London, 1902. Neuteldt, C. a. Der Nahrungsmittelchemiker als Sachverstandiger. Berlin, 1907. * Where such a practice is in vogue an intelligent inspector must of course be chosen with reference to his ability to do this court work. The food laws are few and simple, as are also the court decisions rendered under them, so that it is no great task for the inspector to become much more familiar with them than the average general lawyer whom he meets i in court and who not infrequently consults the inspector for information regarding these laws. 12 FOOD INSPECTION /IND ANALYSIS. PoLiN ET Labit. Examen des Aliments suspects. Paris, 1892. Tucker, W. G. Food Adulteration: Its Nature and Extent and How to Deal with It. Med. Rev. of Rev's, Oct., 1903. Vachee, F. The Food Inspector's Handbook. London, 1893. Wedderburn, a. J. Reports on Extent and Character of Food and Drug Adulteration in the United States. U. S. Dept. of Agriculture, Div. of Chem., Bulletins 25, 32, and 41. Wiley, H. W. Foods and Their Adulteration. Philadelphia, 1907. WuRZBURG,' A. Die Nahrungsmittelgesetzgebung im Deutschen Reiche. Leipzig, 1903. The British Food Journal, London, 1899 et seq. Food and Sanitation, London, 1892-1900 (discontinued August, 1900). Journal of the Sanitary Institute, 1892 et seq. Revue International des Falsifications, Amsterdam, 1888 ct seq. The American Food Journal, Chicago, 1906 et seq. The Food Law Bulletin, Chicago, 1907 et seq. Biennial Reports of the Idaho Dairy, Food and Oil Commission, 1903 et seq. Veroffentlichungen des kaiserlichen Gesundheitsamtes. Berlin, 1877 et seq. Arbeiten aus dem kaiseslichen Gesundheitsamtes. Berlin, 1886 et seq. Reports of the Local Government Board of England, 1877 et seq. Reports of the Paris Municipal Laboratory, 1882 and 1885. Reports of the Canton Chemists of Switzerland, 1890 et seq. Annual Reports of the Massachusetts State Board of Health, 1883 et seq. Monthly Bulletins of the Massachusetts State Board of Health. Annual Reports of the Conn. Agric. Exp. Station on Food Products, 1896 et seq. Annual Reports of the Ohio Dairy and Food Commissioner, 1890 et seq. Annual Reports of the New Jersey Dairy Commissioner, 1886 et seq. Annual Reports of New Jersey Laboratory of Hygiene, Chemical Dept., 1903 et seq. Annual Reports of the Michigan Dairy and Food Department, 1893 et seq. Monthly Bulletins of the Michigan Dairy and Food Department, Aug., 1895 et seq. Biennial Reports of the Minnesota Dairy and Food Commissioner. Annual Reports of the Wisconsin Dairy and Food Commissioner, 1890 et seq. Annual Reports of the Penn. Board of Agriculture, 1894 et seq. Annual Reports of the Illinois State Food Commissioner, 1899 et seq. Biennial Reports of the New Hampshire State Board of Health, 1902 et seq. Quarterly Bulletins of the New Hampshire State Board of Health, 1902 et seq. Annual Reports of the North CaroUna State Board of Agriculture on Food Products, 1900 et seq. Bulletins of the North Dakota Experiment Station. Annual Reports and Monthly Bulletin of the Indiana State Board of Health, 1905 et seq. Official Inspections of the Maine Agricultural Experiment Station. FOOD AN /I LYSIS AND OFFICIAL CONTROL. 13 Annual Reports of the Wyoming State Dairy Food and Oil Commission, 1904 et seq. Quarterly Bulletins of the Vermont State Board of Health. Annual Reports of the South Dakota Food and Dairy Commission, 1901 et seq. Proceedings and Methods of Analysis of the Association of Official Agricultural Chemists, published as bulletins of the U. S. Department of Agriculture, Bureau of Chemistry. Proceedings of the National Association of State Dau-y and Food Departments, 1902 et seq. CHAPTER II. THE LABORATORY AND ITS EQUIPMENT. Location. — The selection of a location for a food laboratory cannot always be made solely with reference to its needs and its convenience, but it is more often subject to economic conditions beyond the analyst's control. Under very best conditions, such a laboratory should be situated in a building designed from the start exclusively for chemical or biological and chemical work. Almost any well-lighted rooms in such a building can be readily adapted for the purpose. When, however, as is frequently the case, rooms for such a laboratory are provided in municipal, govern- ment, or office buildings, in which for the most part clerical work is done, the problem of adequately utilizing such rooms so that they may not at the same time prove offensive to or interfere with the comfort of other occupants of the building is sometimes difficult. It is obvious that base- ment rooms in such a building, as far as ventilation is concerned, are less readily adapted for the requirements in hand than are those of the top floor, though, if the light is good and there are abundant and well-arranged ventilating-shafts, such rooms may be made to serve every purpose. In the basement one may most easily obtain water, gas, and steam, and dispose of wastes without annoyance to one's neighbors. When, how- ever, it is possible to do so, rooms on the top floor of an office building should be utilized for a food laboratory, for in such rooms the problems of lighting, heating and ventilating are comparatively simple and may usually be solved without regard to other occupants. In such a case ample provision must be made, preferably through shafts which are readily accessible for water-, gas-, steam-, and soil-pipes passing down below. The actual equipment of the food laboratory depends of course largely on its particular purpose; and while it is manifestly impossible to do other- wise than leave the details to the individual taste and needs of the analyst, 14 THE LABORATORY AND ITS EQUIPMENT. 15 modified by the means at his disposal, a few general suggestions regarding important essentials may prove helpful. These imply a fairly hberal though not extravagant outlay, with a view to saving both time and energy by convenient surroundings well adapted to the work in hand. At the same time equally satisfactory work is possible under simpler conditions than those described. Floor. — The best material for the floor of the working laboratory is asphalt. Such a floor is firm but elastic, is readily washed by direct appHcation of running water, if necessar}', and resists well the action of ordinary reagents. An occasional thin coating of shellac with lampblack applied with a brush gives the asphalt floor a smooth, hard surface and may be applied locally to cover spots and blemishes. Lighting. — The lighting of the rooms, if on the top floor, is best effected by both wall windows and skylights. North windows furnish the best light for the microscope; the skylight, when available, is the ideal light for the -balance and for general laboratory work. Ventilation by forced draft is a great convenience. For this purpose an exhaust-fan driven by an electric motor and controlled in speed by a fractional rheostat is admirable. Such a fan had best be located in a small closed compartment or closet near the centre of the series of rooms designed to be ventilated by it, and this closet should have directly over the fan an outlet -shaft passing through the roof of the building. With such a system, a series of branching air-ducts should radiate from the fan closet, conveniently arranged either above or along the ceihng and communicat- ing with the various hoods, closets, and rooms near the top. Benches. — The working benches should have wooden or glazed tile tops. White glazed tile, if properly laid, furnish a very clean, sanitary, and resistant surface, besides being often convenient for color tests. If laid on a plank surface, cement should not be applied directly, as it swells the wood before drying out and results in a loose and often uneven surface. Cement may be avoided altogether and the tiles after first soaking in oil may be laid in putty directly on the wood. Tiles may be laid in cement by first covering the plank surface with cheap tin plate, overlapping the edges and securing by tacks. This prevents swelling of the wood. The tin may be covered to advantage with cheap paint. The tiles may then be embedded in a layer of cement spread over the tin surface. Soft encaustic glazed tiles commonly used for wall finish are not as 1 6 FOOD INSPECTION AND ANALYSIS. effective as hard floor tiles, since the former crackle and lose color wheii subjected to heat. If the hard floor tiles can be specially glazed, they make by far the most satisfactory and enduring surface. When wooden bench tops are used they may be treated to advantage by staining with the following solutions: Solution I. loo grams of anilin hydrochloride, 40 grams of ammonium chloride, 650 grams of water. Solution 2. 100 grams of copper sulphate, 50 grams of potassium chlorate, 615 grams of water. Apply solution i thoroughly to the bare wood and allow it to dry; then apply 2 and dry. Repeat these applications several times. Wash with plenty of hot soap solution, let dry and rub well with vaseline. It is claimed that wood so treated is rendered fire-proof and is not acted on by acids and alkalies. When the finish begins to wear, an application of hot soap solu- tion or vaseline will bring back the deep black color. The benches should naturally be located with reference to best light from skylights or windows. Gas and water outlets, sinks and waste-pipes should be conveniently arranged with reference to the working benches, as well as suitable provisions for air-blast and exhaust, while in the space be- neath the benches such drawers, cupboards, and receptacles as are required should be provided. A clear bench width of 24 inches is ample for most work; if wider there is a temptation to allow apparatus to accumulate at the back. At the back of the bench and within easy reach, a raised narrow shelf should be provided to be used exclusively for common desk reagents. This again should not be so wide as to allow the accumulation of useless bottles. A narrow raised guard or beading at the edge of the reagent shelf prevents the bottles from accidently slipping off. Hoods. — Closed hoods with sliding sash fronts are almost indispensable. These hoods should be directly connected with the ventilating shafts or pipes, or with the air-ducts that radiate from the exhaust-fan closet, when such a system is jirovided. Gas outlets inside the hoods are neces- sary. When there is a good draft, either natural or forced, a hooded top over the working bench, such as that shown in Fig. 3, is quite as efficient as a closed hood for most purposes. This is best made of galvanized iron, painted on the outside and treated on the inside with a preparation of graphite ground in oil. Here are best carried out all the processes involving the giving off of fumes and gases, which, if the ventilation is efficient, should pass directly up the flues and not come out in the room. THE LABORylTORY AND ITS EQUIPMENT. ^7 Sinks and Drains. — The sinks should preferably be of iron or porce- lain. If iron, they should at frequent intervals be treated with a coat of Fig. 3. — ^Hooded Top of Galvanized Iron over Working-bench, Connected with Ventilating Air-ducts. asphalt varnish. A great convenience is a hooded sink (Fig. 4) in which foul-smelling bottles, or vessels giving off noxious or offensive fumes FOOD INSPECTION AND ANALYSIS. or gases, may be rinsed under the tap while completely closed in. Open- work rubber mats at the bottom of the sinks help to insure against break- age. Open plumbing of simplest design should be used, and a multi- plicity of traps should be avoided. Sinks may be variously located for Fig. 4. — A Hooded Sink. An injector-like arrangement of steam and cold-water pipes furnishes water of any desired temperature. convenience v^^ithout regard to situation of soil-pipes, if the floor is thick enough to allow an open drain with sufficient pitch to flow readily. Such open drains are much more readily cleaned than closed pipes, and are best constructed by splitting a lead pipe and laying it in an iron box which is sunk into the floor. The edges of the lead pipe are rounded over those of the box as in Fig. 5, filling the joints with hydraulic cement, and the top of the drain is covered by a series of readily removable iron plates THE L/l BORA TORY AND ITS EQUIPMENT. 19 flush with the top of the floor. Waste-pipes from sinks, stiU-condensers, refrigerators, and various forms of apparatus involving flowing water may be led into this drain, holes being drilled in the iron cover for their insertion. Steam and Electricity. —These are useful but not indispensable. Steam, when avaflable, may be used to advantage for boiling ether or benzine in connection with continuous fat-extraction apparatus, for furnishing the motive power for driving the Babcock centrifuge, for heating water- baths and hot closets, and, in connection with cold water, to furnish a Fig. 5. — Section of Open Drain-pipe in Floor. supply of hot water when wanted at the sink. The latter application is illustrated in Fig. 4. If electricity is used for lighting, it may also be applied in a variety of useful ways in the laboratory, as, for instance, for heating coils or electric stoves, for electrolysis, and for running small motors, which in turn may be employed for driving centrifuges, shaking apparatus, ventilating- fans, air-pumps, etc. Suction and Blast. — If the water-pressure is ample, both air-pressure and exhaust for blast-lamps, vacuum filtration, and other purposes are readily available through the agency of the various devices used in con- nection with the flow of water, as, for instance, the Richards pump. When, however, the water pressure is insufficient, other means must be employed for furnishing these much-needed requisites. Fig. 6 illustrates a simple and almost noiseless pressure and exhaust pump run by a i-H.P. electric motor, which with the pressure-equahzing tank and the appropriate connections are mounted on a light wheel truck, and readily movable to any part of the laboratory. By simply screwing the plug into an 20 FOOD INSPECTION AND /INALYSIS. electric-light outlet, either suction or blast may be had at will, depending on the position of a knife-edge switch which determines the direction of the current. By means of a fractional rheostat the speed may be varied and the pressure thus controlled. Fig. 6. — Portable Pressure- and Exhaust-pump Run by Electric Motor. Useful for blast- lamps, vacuum filtration, etc. APPARATUS. The laboratory is of course to be supplied with the usual assortment of test-tubes, flasks, beakers, evaporating and other dishes of porcelain, platinum and glass, funnels, casseroles, crucibles, mortars, burettes, pipettes, graduates, rubber and glass tubing, lamps, ring-stands and various supports, clamps and holders, the nature, number, and sizes of which are determined by individual requirements. Special forms of apparatus peculiar to certain processes of analysis or to the examination of special foods will be described in their appropriate connection. The following apparatus of a general nature may be regarded as indispensable for the proper fitting out of the food laboratory: Balances. — These should include (i) an open pan balance for coarse weighing, having a capacity up to i kilogram and sensitive to o.i gram, with a set of weights; and (2) an analytical balance, enclosed in a case, sensitive to .0001 gram under a load of 100 grams, with an accurate set of non-corrosive weights. The short-beam analytical balance is prefer- THE LABORATORY AND ITS EQUIPMENT. 21 able for quick work, and as constructed by the best modern makers leaves nothing to be desired. The Water-hath.— ^Thh is such an important accessory to the food analyst that it should, if possible, be specially designed to meet his require- FiG. 7. — ^Water-bath, Enclosed in Hood, with Sliding-sash Front. ments, though the ordinar}^ copper baths, supported on legs and designed to be heated by gas-burners, as kept in regular stock by the dealers, will sometimes serve the purpose. For nearly all moisture determinations the platinum dishes described on page 133 and the somewhat larger wine-shells of 100 cc. capacity are most used, and for this purpose the top of the bath should have plenty of openings of the right size for these. A very economical construction of bath admirably adapted for the food analyst's use is shown in Fig. 7, being the form employed by the writer. 22 FOOD INSPECTION y4ND ANALYSIS. The size and number of openings are determined by the number of samples to be simultaneously analyzed. A steam coil within the body of the bath serves to boil the water. Fig. 7 also shows the hood for carrying off the steam and fumes, the sliding front of which is furnished with a hasp and a padlock, so that it may always be kept locked by the analyst whenever he is temporarily absent from the laboratory. This is a useful precaution, when the residues left thereon are from samples which are to form subjects for possible prosecution in court later. Steam, if available at all seasons of the year, or electric immersion Fig. 8. — Freas Electrically Heated Drying Oven with Accurate Temperature Control. coils furnish a ready means of heating the bath. In the absence of both steam and electricity, the bath must be boiled by gas burners. The Drying-oven. — Water ovens heated by gas and steam ovens have the disadvantage that the drying cell seldom reaches a temperature above 98° C. The electric oven shown in Fig. 8 obviates this difficulty, the regulator permitting of adjustment so that full 100°, as well as any desired temperature, can be attained. Fig. 9 shows an asbestos-covered, jacketed air-oven, heated by a gas burner, with an efficient form of gas- pressure regulator. The Water-still. — An efficient still should be provided, capable of supplying the laboratory with an ample quantity of pure water for analyti- cal purposes. Fig. 10 illustrates a compact form of still, which is particu- larly economical in view of the fact that a single stream of inflowing cold THE LABORATORY AND ITS EOUIPMENT. water first serves to cool the condenser, and, rising, becomes vaporized in the boiler directly connected with the condenser at the top. This apparatus is capable of distilling six gallons of water in twelve hours. Fig. 9. — Asbestos-covered Air-oven, with Gas-pressure Regulator. The list of indispensable requisites in addition to the above should include the following: Continuous Extraction Apparatus (Figs. 20, 21, and 22). Apparatus for Nitrogen Determination (Figs. 26, 27a, and 2'jb). Apparatus for Distilling Various Food Products (pp. 71 and 660), A Babcock or other Milk-fat Centrifuge (Figs. 11 and 45). A Butyro Refractometer (Fig, 38). An Immersion Refractometer (Fig. 42). A Microscope and its Appurtenances (Chapter V). A Polariscope and its Accessories (Figs. 102, 103, and 104). Apparatus for Specific Gravity Determination (Figs. 14, 15, 16, and 17). Apparatus for the Determination of Carbon Dioxide (Fig. 71). Apparatus for the Determination of Melting-points (Fig, 93). Marsh Arsenic Apparatus (Fig. 28). Electrolytic Apparatus (Fig. no). Separatory Funnels (Figs. 24 and 25). Following is a hst of apparatus and appliances which, while not in- dispensable, are convenient and at times desirable : 24 FOOD INSPECTION AND AN /t LYSIS. A Spectroscope, either of the direct-vision variety for the pocket, or the Kirschoff & Bunsen style on a stand. Spectroscope Cells, parallel-sided, for observation of absorption spectra. A Photomicrographic Camera and Appurtenances'^ (pp. 96 to 98). A Muffle Furnace, gas (Fig. 3) or, preferably, electric (Fig. 19). Fig. 10. — ^A Convenient Laboratory Water-still with Earthenware Receptacle, Provided with Faucet and Glass Gauge. An Incinerator for a Large Number of Residues (Fig. 52). An Ehullioscope (Fig. 113). An Assay Balance, for weighing arsenic mirrors to o.oi mg. An Abbe Refractometer (Fig, 39). A Schreiner Colorimeter (Fig. 30). A Lovibond Tintometer (p. 78). * A photographic dark room is also necessary if photomicrographic work is to be done* THE LABORATORY AND ITS EQUIPMENT. 25 A Universal Cenirijuge. — This convenient apparatus merits a separate brief description, being useful for a wide variety of purposes, such as breaking up ether- and other emulsions, quickly settling out precipitates, and roughly estimating chlorides, sulphates, phosphates, etc., by the volume of the precipitate in graduated tubes. Various-sized aluminum frames, carrying hinged shields, are interchangeably adjustable to the Fig. II. — The Universal Centrifuge. Driven by an electric motor. spindle of a vertical electric motor.* The smallest frame has shields adapted to hold two graduated glass tubes of 15 cc. capacity (see Fig. 11). This is for the quantitative estimation of small precipitates and the quick settling of sediments. A medium-sized and large frame carry tubes of 80 cc. and 120 cc. capacity respectively. A frame is also provided with shields adapted for various-sized beakers to be used in settling pre* cipitates. The various types of centrifuges used for the Babcock test (P- 137) ^^^y 3-lso be used for general work. * In the absence of electricity a vv^ater-motor may be used. 26 FOOD INSPECTION ^ND ^N^LYSIS. t P^ Ph P5 ^ ci Ov h 00 Pi o fO ITi M 00 CMO -t o 00 o S fe s |o ^ o:? Si J£^-S g?^ , 'n o vo ^ o wS 1?^ do 6 6 6 d Wffi 6W "00 .... o°;S ■^■^ -0^ o oo .o O Cr-S S >0 ^«^ T)T-,vO O "^ n . c3 ■ " , " C Jp C)0 vO .jj_q"SO .odo'cO^'-OO . Ntot:^-,*^ 00 t^ O O. t "O rj- ■^OOCJ^^N^ ^OtNOO'^r-r^. H4 00 M .d tu 'ji; 00 CO r^QO oo o- !3 ooo ►-"m."'2'H'-< dddddddd ■u 2 "i • ^: c^ b-d ^ &::::::: (i- oo^p, o,. .---.. O -^ 0000 ■^6 ^5: Sue 2u 0) 1/3 S22 0) o g O ooQ 2-^ ouffi E ^ "=« ^^ ^.a ^ o I- Ji-H_" V- o I- o 1- •2'S S 01=! O , . . . »« W ^ ^ lU .>^ • g O'-' •■X O .Si O X »ooQ M «2;uQ O 00 q o o- P.O. o o P.P> Kg u Kw -R t o o "1 o <; C t^ U-1 N M Oo5 Co 6' O O "= M « co^t/lvO t^oO 0\0 i-t N rc^w^vO t^oC 0>0 "33 h9, .; CO iB '-B E_ E ^ =1 THE L/1BOR/1TORY /tND ITS EQUIPMENT. 27 Q.^ w| 2*3 o-d "•d • a , o-d . osq ffi ^feK ±! O o lo v! 1/1 d d =( oi a- C/DC/2t/3" .2 Vc '^ ~, ^Z M « ro .■£z „ ZBo "gZ ax sao g-8 tflT) '^ mS ° o « D ^ M 6 a . ci o O^- f_ o . -^ (uUao ^ is " ".S •rts ^ OJ ^ n ed c 01 •rt b a; > :d Sjffi';; _ o ^''G O'o I- 1; 0! "* o :3 „ o S N " E'-^ <^0 '" "W 3.3 s O - p p-d-^ 'f o 3.2 « o <-d-3-" s:2 m'd h !2 C d c-d oj S 2 >, p<; p.g M^ 1) 60 •~ 60 O «>o W in « ^ o ^^ >< K, .^ 0) 60 !< r- t? 60 C/D ■* TjZ C ..-rt O (S o o-j; iH oh o Qomo m c pi •dO, ZQJfeQZ ts'ta.2 "".2 Jr 1- oJr o QuwQw c5;4 q d d ffiw 04? cam rt-d !2S cs ^ S E- 13^- oft- ftp. •S3 33 rt- o^ ^^ gft ^ 9. Cd rn " dj: .«-d •d"u ■c: : cfl 03 rt mm m 00 M C -0 t^ r^ t SE .P-d n O 3a ■" 60 c 01 2 ?;- c T) ^ c a u J3 "« E ^ a V- r>.oO 00 00 28 FOOD INSPECTION /IND ANALYSIS. H n ^ 0) c . .s 4) (D rl W ^ 5 =i ^ 0) "" a CD Wc 1 IS te C in o Q,M 3 o w ° "I'd O Hi ?s= o ca--^ .2'd-d OQcrt UccO 13.2 -2 u oi; c OmQw ^ ^ ^O Om q q u-Jo -d »^B" pJ t5 c; c^ cij GJ CTJ nj uoou c3 a; •C'C o o -5? ^. ^ ;=i;:i .ii^^ ^,0 r^oo O O 3 S-^S-fl OOPWW 0*0'OiO\0\ O-O'O^O^Q'OOO lO t^OO o* o THE LABORATORY AND ITS EQUIPMENT. 29 So 0) 3 J- 1- P-cH O CO S"?.'^ "rt '5 .Si « c S, O •> J- (U o -^ 3 M H_ «! Oj ^ M fLi+J bp ft U - OJ a,, lu ,9 ,'- rt u (n 2W CO O Hcocfi be &o ft O. w 01 3 ^ o ►^ % o ftiS ■!-> ■ (0 IfC •c- „, rt C >< ft' C.2 M-1 3 "^ bO ^- Si 0) C OOK •S i. ^.S 2 O i3 - •p.fl S ** P- - - - bc B 43" f-^ ^ lAvO r^oo o> o >- 30 FOOD INSPECTION AND ANALYSIS. £3 .s o> w « ■d X'a l-c>7 +1 •o ?^ 3 T-W & w m CU (U r; MM-t3 ol (A So 2 IT'S S "Oo -d pi C C i^z.:^e 8 dSd^- Ol ssolve tion cc. liter, 13 0) a Q rt, pawed COW ^ 'S^ o iJ °.o & q W) c wm bo bo ■3.2 ^ C'^u > a^wR o ^.o.-2 SCO :3 '^ qZS ft ^ E •gftfto; n! 4> dj 4J "3- .2 rt.2 rt.S'S.^ 3.2 S S3 C S 3 >, 3 >, 3 v3 >>^ >,^ >'^- Oc«Q20' u MQMQwuc^iQc 1- c 1- Z U 2 Co « 3 2 SO qOc«: o9 J3 JD O O E S v:; ^3 j= c- ^^ o o-g 1%. gXl o" - O - u •a -.2 C rt.2. - - -d-d 3 O r^-^ino I^CO CO 0\O r^oo 0« 32 FOOD INSPECTION AND ANALYSIS. hi'a:2 •c ^ P a! c c^ ^ ° ao .t. — ^ fi "U ■^ i^l c -^ ,„.2* .2 -oS" ■a 'Bi <; <: ii:s Sffiw 6 J5 P.0 p^ .a _, jj a" o C .5^-^ o c O S as Ji";'^ o rt J! CO ;U g ft m 4d « S " S^^'i^. M M M be Ji ctf 03 cd cii c ft P-P-O-l^ 1) a; uj 0) „ C/2 MC/}M< •ccd CO ^ Pi < H w w Pli I to W O < !" c..ti o3'S «5 c n! rt G M rt 01 n! a (U 1* o t/J o ^ d aJ Ecu "^ "" .X! gS d^ rt ■^ M £ c ■ 5 >-^ "2x ;:; ^ r^ ^ O •S " S^ 0) 0) ^ C ^^ o o o o 0.'-3 QQ w u o .6 KM qo r, -Sffi 2 6Q ■^ CSS t;S ^ "5.2 d nlTJ d.2 m ■" to m "^ m ■" >>^ >, >.-5 >.— Vi O *- ^- ^ t- O OC0OO O a -C u ^ t^ 11 I) 3 S2 O 0- 00 be "3 E C c S 3 a o tfl nl fe C/3 OJ 0) b -MO) c^ S ^£ 5 in o o O " a-- O ^ k '-•2 ^r, 00 0\ ii ni M Oi OC fn °~B'o r^ c s"^ " " • c c c d ■.2 .0 _o :_2 3 _2 C -o •o-c •"s •G •a "o (U 0) a. . t/1 lU in bo "5i 3 — C t3 • ^^ ts c!:S .2 ^-o (U P "o 5-2 ii °3s 2 iS.2 ni 1. c c £ X. o O i-i •a >. C a ■■rt d e c c "c c : £ C CI •5 D c c □ c 'S c > '- £ c C! ? Cl! •« M- e E5 '^ -a E -•& (U c c X c c 'l- 'c > 1 •c c c E 4- •c 'e c C K2 cu cL,a< 0- •fl -«~ ■" Cl, OiMM tSl d 2; V - « r-) rr UIO r^oo Ov O '-' N r*^ ^ lAO X 0\ 0\ Ov Ov ON ^ O Oi OS 0\00 ooooo " ^ c " " M n " 5 "5 ■> f 5 <» ) f - " ' i THE LABORATORY AND ITS EQUIPMENT. 35 REAGENTS. The foregoing list includes the general reagents used in carr)ang out the processes treated of in this volume, together with their strength, mode of preparation when necessar}', and other data. Reagents, especially those constantly employed, should be assigned to regular places on the shelves, and sho.uld invariably be kept in place when not in use. Among the standard solutions for volumetric work, none is more frequently of service in the food labora- tory than a tenth-normal solution of sodium hydrox- ide, and a large supply of this reagent, carefully standardized, should be at all times conveniently at hand. Besides being useful for standardizing tenth- normal solutions, it is constantly needed for deter- mining various acids in food products, such as milk, vinegar, butter, Hme juice, cream of tartar, liquors, and many others. Time is well spent in carefully ad- justing this solution to its exact tenth-normal value, thus simpUfying the calculation of results. A large stock bottle (say of two gallons capacity) containing the standard tenth-normal sodium hydroxide, is con- veniently mounted with a side-tube burette in con- nection, in some such manner as shown in Fig. 12. A small connecting side bottle contains a strong solution of sodium hydroxide (reagent No. 240) through which the air that enters the large bottle is passed, thus depriving it of CO2. In this manner the standard solution may readily be kept of unvarying strength for a year or more. Fig. 12.— Stock Bot- tle of Tenth-normal Alkali. 36 FOOD INSPECTION AND ANALYSIS. EQUIVALENTS OF STANDARD SOLUTIONS. No. 31. Decinormal Sulphuric Acid. One cc. is equivalent to Ammonia gas NH3 0.0017 gram. Ammonia NH,OH 0.0035 Ammonium carbonate (NH J2CO3 o. 0046 (NHj^COsjHoO 0.0057 Calcium carbonate CaCOg. — 0.0050 Calcium hydroxide Ca(OH)2. 0.0037 " oxide CaO 0.0028 Lead acetate Pb(C2H302)2,3H20 0.0189 Magnesia MgO o . 0020 Magnesium carbonate MgC03 0.0042 Nitrogen N 0.0014 Potassium acetate * KC2H3O2 o . 0098 bicarbonate KHCO3 o.oioo bitartrate * KHC^HPe 0.0188 carbonate KjCOg 0.0069 citrate* K3CeH507,H20 0.0106 hydroxide KOH 0.0056 and sodium tartrate . KNaC^H^08,4H20 0.0141 Sodium acetate NaC2H302,3H20 0.0136 benzoate * NaC^HjOj 0.0144 bicarbonate NaHCOg 0.0084 borate NaoB^O^jioHjO 0.0191 carbonate NajCOg 0.0053 " Na2C03,ioH20 0.0143 hydroxide NaOH o . 0040 salicylate* NaC7H503 0.0160 No. 241. Decinormal Sodium Hydroxide Solution. One cc. is equivalent to Acid, acetic H,C2H302 0.0060 gram. " boric H3BO3 0.0062 " citric HjCeH.O^HaO 0.0070 ** hydrobromic HBBr 0.0081 " hydrochloric HCl 0.00365 " hydriodic HI 0.012S ' ' lactic HC3H5O3 o . 0090 " malic C^HgOj 0.0067 " nitric HNO3 0.OC63 " oxalic HjC^O^-H^O 0.0063 „ , , . TT T^r^ \ to form KoHPO.with ) phosphoric H3PO,-^ phenolphthalein f °-°°^9 ., , , . .. ^^ S to form KHoPO.with ) " phosphoric H,PO '1 . , " r o.oogS ^ ' ■* M methyl orange ) " sulphuric HjSO^ 0.0049 " tartaric HoC^HjOe 0.0075 Potassium bitartrate KHC^H^Oe 0.0188 Sodium borate NagB^OyjioHjO 0.00955 * To be ignited. THE LABORATORY AND ITS EQUIPMENT. 37 No. 142. Decinormal Iodine Solution. One cc. is eriuivalent to Arsenious oxide AsjOg 0.00495 gram. Potassium sulphite K2S03,2H20 0.0097 Sodium bisulphite NaHSOg 0.0052 " sulphite, Na2S03,7H20 0.0126 " thiosulphate Na2S203,5H20 0.0248 Sulphur dioxide SO2 0.0032 Sulphurous acid H2SO3 0.0041 No. 245. Decinormal Sodium Thiosulphate Solution. One cc. is equivalent to Bromine Br o . 0080 gram. Chlorine CI 0.00355 " Iodine I 0.01266 " Iron (in ferric salts) Fe 0.0056 " No, 230. Decinormal Silver Nitrate Solution.* One cc is equivalent to Ammonium bromide NH^Br 0.0098 gram. " chloride NH^Cl 0.00535 ". Chlorine CI 0.00355 " Cyanogen (CN)2 0.0052 " Hydrocyanic acid HCN with indicator 0.0027 " ,-. _^_ ( to formation of precip- ) HCN J . r 0.0054 ( itate ' ^^ Hydrobromic acid HBr 0.0080 " Potassium bromide KBr 0.0119 " " chloride KCl 0.00745 " " cyanide KCN with indicator 0.0065 " ,, ,, T^^--. ( to formation of precip-) ,. KCN -^ . ^ f o.oi^o I itate ..f -^ Sodium bromide NaBr 0.0103 " " chloride NaCl 0.005S5 " No, 201. Decinormal Potassium Bichromate Solution.! One cc. is equivalent to Ferrous carbonate FeCO^ 0.0116 gram. Ferric oxide FcjOj 0.0080 " Ferrous oxide FeO 0.0072 " " sulphate FeSO^ 0.0152 " " FeSO,,7H20 0.027S " Iron (ferrous) Fe 0.0056 " No. 220. Decinormal Potassium Permanganate Solution. One cc. is equivalent to Oxalic acid H2C20^,2H20 0.0063 gi''ini» and to same weights for iron salts as given under N/io K2Cr207. * Use potassium chromate solution as an indicator, or add till precipitate appears. t Use a freshly prepared solution of potassium ferricyanide as an mdicator, applying a drop of titrated solu- ^tion to a drop of indicator on a white surface. 38 FOOD INSPECTION AND ANALYSIS. The following table from Talbot * shows the reactions of the com- mon indicators used in acidimetry: Indicator. Reaction with Acids. „ ^- 1 Use with Reaction j Carbonic .,;^'h Acid in Cold Alkalies. 1 v,„i^t.on. Use with Carbonic Acid in Hot Solution. Use with Ammonium Salts. Use with Organic Acid. Litmus Red Pink Colorless Purple-red Purple-red Yellow Yellow Blue Yellow Pink Blue Blue Pink Red Unreliable Reliable Unreliable Unreliable Reliable Unreliable Unreliable Reliable Unreliable Reliable Reliable Reliable Reliable Reliable Reliable Rehable Unreliable Reliable Reliable Unreliable Reliable Reliab.3 Methyl orange. . . Plienolphthalein. . Lacmoid Cochineal Rosolic acid Alizarine Unreliable Reliable Unreliable ( ?) Unreliable Unreliable^ Reliable * Talbot, Quantitative Analysis, page 75. j- Reliable with oxalic acid. REFERENCES ON LABORATORY EQUIPMENT, REAGENTS, ETC. Adriance, j. S. Laboratory Calculations. New York, 1897. ArKiNSON, E. Suggestions for the Establishment of Food Laboratories. U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 17. C\)HN, A. J. Tests and Reagents, Chemical and Microscopical, known by their Authors' Names. New York, 1903. K ENWOOD, H. R. Public Health Laboratory Work. The Hygienic Laboratory. Phila- delphia, 1893. Ejiauch, C. Testing of Chemical Reagents for Purity. London, 1903. Lunge, G., and Hurter, F. Alkali-maker's Handbook. London, 1891. Mayrhofer, j. Instrumente und Apparate zur Nahrungsmittel Untersuchung. Leipzig, 1894. Mercks 1907 Index. Merck & Co., New York. Schneider, A. Reagents and Reactions known by the Names of their Authors. 1897. S'JTTON, F. Volumetric Analysis. 8th Ed. Philadelphia, 1900. TlORPE, T. E. Dictionary of Applied Chemistry. London, 1912. CHAPTER III. FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, AND NUTRITIVE VALUE. Nature and General Composition. — Food is that which, when eaten, serves by digestion and absorption to support the functions and powers of the body, by building up the material necessary for its growth and by supplying its wastes. The raw materials that constitute our food- supply are not all available for nourishment, but often contain a propor- tion of inedible or refuse matter, which it is customar\' to remove before eating, such as the bones of fish and meat, the shells of clams and oysters, eggshells, the bran of cereals, and the skins, stones, and seeds of fruits and vegetables. The proximate components which make up the edible portion of food include in general water, fat, various nitrogenous bodies consisting chiefly of proteins, carbohydrates, organic acids, and mineral matter. Of these water is hardly to be considered as a nutrient, though it plays an important part in nearly all foods as a diluent and solvent. •The fats, proteins, and carbohydrates all contribute in varying degree to the supply of fuel for the production of heat and energy. Besides this universal function, the fats and the carbohydrates serve especially to fur- nish fatty tissue in the body, while the proteins are the chief source of muscular tissue. Liebig's classification of foods into nitrogenous, or flesh formers, and non-nitrogeneous, or heat generators, is now no longer accepted as strictly logical, in view of the well-known fact that the nitrogenous materials, besides building up the body, aid in supplying the wastes and yielding energy, and may even be converted into fats or carbohydrates, while the non-nitrogenous aid in furnishing tissue growth in addition to serving as fuel. The Fat of Food. — Fats are the glycerides of the fatty acids, the characteristics of the various edible fats and oils being treated of under 39 40 FOOD INSPECTION AND ANALYSIS. their appropriate headings elsewhere. Fat in human food is supplied by milk and its products, by the adipose tissue of meat, and in slight extent by the oil of cereals and by the edible table oils. The term "ether extract" is sometimes used in stating the results of the analysis of foods and this includes other substances than fat which when present are extracted by ether, such as chlorophyl and other coloring matters, lecithin, alkaloids, etc. Nitrogenous compounds and their Classification.— These sub- stances may for convenience be grouped as follows: A Proteins, B Amino-acids and Amides, C Alkaloids, D Nitrates, E Ammonia, and F Lecithin. A. Proteins. — This term includes a large number of nitrogenous bodies consisting, according to our present knowledge, essentially of combinations of a-amino-acids and their derivatives. Proteins in one form or another exist in nearly all natural foods both animal and vegetable. The terms "proteids" or "albuminoids "were formerlyused genericallyas synonymous with "protein" to include all nitrogenous bodies of this group, but recently a joint committee on protein nomenclature of the American Physiological Society and the American Society of Biological Chemists recommended that the word "pro teid" be abandoned; that "protein" be used to designate the entire group; and that the word "albuminoids" be restricted to a sub- group of proteins. A committee of the Physiological Society of England also made the same recommendation as to the. use of the term protein. The classification and most of the definitions here given are those adopted by the American committee.* Proteins available for food are supplied chiefly by the flesh of meat and fish, by milk, cheese, and eggs, and in the vegetable kingdom by seeds, nuts, and vegetables, especially the legumes. The proportion of crude protein, often designated merely as "protein," is commonly estimated by multiplying by 6.25 the percentage of nitrogen found in the material analyzed. This is done on the assumption that all of the nitrogen present in the substance belongs to protein containing 16 per cent of nitrogen. There is no marked distinction in chemical constitution between animal and vegetable proteins, although some of the types have as yet been found only in one or the other kingdom. All proteins are insoluble in pure alcohol or in ether. A few arc soluble in water but most arc not. Nearly all are soluble in very dilute acids or alkalies, while all are decomposed by' boiling with concentrated mineral acids or concentrated caustic alkalies. All proteins are la;vo-rotary with polarized light. * Am. Jour. Phys., 21, 1908, p. xxvii. FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 41 ' Qualitative Test for Proteins. — Xanthoproteic Reaction. — Concen- trated nitric acid added to a solution of a protein may or may not form a precipitate. It, however, produces a yellow coloration on boiling. Addi- tion of ammonia in excess turns the precipitate or liquid yellow or orange. Millon's Reaction. — Millon's reagent No. 184, page 30, when added to a protein solution produces a white precipitate, which becomes brick-red on heating. Sodium chloride prevents the reaction. Various organic substances are precipitated by Millon's reagent, but these precipitates do not turn red on heating. Biuret Reaction. — If a solution of a protein in dilute sulphuric acid be made alkaline with potassium or sodium hydroxide and very dilute copper sulphate be added, a reddish to violet coloration is produced, similar to that formed if biuret* be treated in the same way, hence the name. An excess of copper sulphate should be avoided lest its color obscure that of the reaction. In solutions which are strongly colored this reaction is of little use unless modified as follows: A considerable quantity of the dilute copper sulphate solution is added to the solution made alkaline with a large excess of potassium hydroxide, and then solid potassium, hydroxide is dissolved to almost complete saturation in the solution. The miixture is then shaken with about one half .its volume of strong alcohol. On standing the alcohol separates as a clear layer of a violet or crimson color if proteins are present. I. THE SIMPLE PROTEINS. — Protein substances which yield only a- amino acids or their derivatives on hydrolysis. Although no means are at present available whereby the chemical individuahty of any protein can be established, a number of simple pro- teins have been isolated from animal and vegetable tissues which have been so well characterized by constancy of ultimate composition and uniformity of physical properties that they may be treated as chemical individuals until further knowledge makes it possible to characterize them more defi- nitely. (a) Albumins. — Simple proteins soluble in pure water and coagulable by heat. Examples. — Seralbumin of blood and other animal fluids; lactalbumin of milk; leucosin of the seeds of wheat, rye, and barley; legumelin of legu- minous seeds. * Biuret is the substance formed by heating urea to 160° according to the following reaction: 2CON2H, = CjOjNjHs + NH3. Urea Biuret Ammonia 42 FOOD INSPECTION AND ANALYSIS. Coagulation. — Animal albumins usually coagulate at about 75°; ■vegetable albumins at about 65°. Miscellaneous Reactions, — Very dilute acids precipitate albumins with the aid of heat. Nitrate of mercury (in dilute nitric acid) precipitates albumins from their solutions; also Mayer's solution acidified with acetic acid. They are precipitated by saturation with ammonium sulphate. These reactions are not, however, characteristic of the group. (b) Globulins. — Simple proteins insoluble in pure water, but soluble in neutral solutions of salts of strong bases with strong acids. Examples. — Myosin of muscle substance; legumin of leguminous seeds; amandin of almonds. Qualitative Tests. — Globulins are precipitated from their solution by dialysis or dilution. Albumins are not thus precipitated. (c) Glutelins. — Simple proteins insoluble in all neutral solvents, but readily soluble in very dilute acids and alkalies. Examples. — Glutenin of wheat is the only well defined protein of this group. (d) Prolamins. — Simple proteins soluble in relatively strong alcohol (70-80 per cent), but insoluble in water, absolute alcohol, and other neutral solvents. Examples. — Gliadin of wheat; zein of maize; hordein of barley. Found as yet only in the seeds of cereals. The use of appropriate prefixes will suffice to indicate the origin of compounds of sub-classes a, b, c, and d, as for example: ovoglobulin, myalbumin, etc. (e) Albuminoids. — Simple proteins which possess essentially the same chemical structure as the other proteins, but are characterized by great insolubility in all neutral solvents. Examples. — Keratins of hair, nails, hoofs, horn, feathers, etc.; elastin of connective tissues; collagen of connective tissues and cartilage; fibroin and sericin of raw silk. No albuminoids have yet been discovered in plants. Gelatin is usually regarded as an albuminoid but does not come strictly within the requirements of the above definition. It is an artificial deriva- tive of collagen and is formed from it by boiling with water or subjecting to steam under pressure. It is prepared from bones and other animal parts, and is insoluble in cold, but soluble in hot water. When the hot water solution containing one per cent or more of gelatin cools, it forms a jelly. By prolonged boiling the gelatinizing power is lost. Aqueous solutions are strongly laevo-rotary. FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 43 Gelatin in common with most proteins is precipitated from its solution by mercuric chloride, picric acid, and tannic acid. It is readily distin- guished from soluble proteins, in that it is not precipitated from its solution by lead acetate, nor by most of the metallic salts that throw down proteins. (f) Histones. — Soluble in water and insoluble in very dilute ammonia, and, in the absence of ammonium salts, insoluble even in an excess of ammonia; yield precipitates with solutions of other porteins, and acoagu- lum on heating, which is easily soluble in very dilute acids. On hydrolysis they yield a large number of amino-acids, among which the basic ones predominate. Examples. — Thymus histone. Not found in plants. (g) Protamins. — Simpler polypeptides than the proteins included in the preceding groups. They are soluble in water, uncoagulable by heat, have the property of precipitating aqueous solutions of other proteins, possess strong basic properties, and form stable salts with strong mineral acids. They yield comparatively few amino-acids, among which the basic amino-acids greatly predominate. Examples. — Salmin, clupein, and other protamins of fish spermatozoa. Not found in plants. II. Conjugated Proteins.— Substances which contain the protein molecule united to some other molecule or molecules otherwise than as a salt. (a) Nucleoproteins. — Compounds of one or more protein molecules with nucleic acid. Examples. — The nucleins formed by pepsin digestion. (b) Glycoproteins. — Compounds of the protein molecule with a sub- stance or substances containing a carbohydrate group other than a nucleic acid. Examples. — Mucins; ovomucoid; ovalbumin. (c) Phosphoproteins. — Compounds of the protein moiCCule with some yet undefined phosphorus-containing substance other than a nucleic acid or lecithins. Examples. — Casein of milk; vitellin of egg yolk. (d) Haemoglobins. — Compounds of the protein molecule with haematin or some similar substance. Example. — Oxyhaemoglobin of red blood corpuscles, (e) Lecithoproteins. — Compounds of theprotein molecule with lecithins, (lecithans, phosphatides). Examples. — Lecithalbumin ; lecithin-nucleovitellin. 44 FOOD INSPECTION AND ANALYSIS. III. Derived Proteins. 1, Primary Protein Derivatives. — Derivatives of the protein mole- cule, apparently formed through hydrolytic changes which involve only slight altterations of the molecule. (a) Proteans. — Insoluble products which apparently result from the incipient action of water, very dilute acids or enzymes. Examples. — Edcstan; blood librin; insoluble myosin. (b) Metaproteins. — Products of the further action of acids or alkalies, whereby the molecule is so far altered as to form products soluble in very weak acids and alkalies, but insoluble in neutral fluids. Examples. — Acid albumin; alkali albumin. This group will thus include the familiar "acid proteins" and "alkali proteins," not the salts of proteins with acids. (c) Coagulated Proteins. — Insoluble products which result from (i) the action of heat on their solutions, or (2) the action of alcohol on the protein. Examples. — Albumin coagulated by heat or alcohol. 2. Secondary Protein Derivatives. Products of the further hydro- lytic cleavage of the protein molecule. (a) Proteoses. — Soluble in water, uncoagulated by heat, and precipi- tated by saturating their solutions with ammonium or zinc sulphate. As thus defined this term does not strictly cover all the protein deriva- tives commonly called proteoses, e.g. heteroproteose and dysproteose. Subdivision of the Proteoses. — According to the proteins from which they are derived the proteoses may be designated albumose, from albumin, globulose, from globulin, vitellose, from vitellin, caseose, from casein, etc. Proteoses are suhdiy'ided into proto-proteose ^ soluble in water (both cold and hot) or in dilute salt solutions, but precipitated by saturation with salt; hetero-proteose, insoluble in water, and deutero- proteose, soluble in water, but not precipitated by saturation with salt. Vegetable proteoses are sometimes called phyt-albumoses. Qualitative T^5/5.— Besides responding to the biuret reaction (p. 41) proteoses are precipitated by nitric acid, the precipitate being soluble on heating, but reappearing on coohng, Proto-proteose is precipitated from its solution by mercuric chloride and copper sulphate ; hetero-proteose is precipitated by mercuric chloride, but not by copper sulphate. (b) Peptones. — Soluble in water, uncoagulated by heat, and not pre- cipitated by saturating their solutions with ammonium sulphate. FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 45 Qualitative Tests. — Besides giving the biuret reaction, peptones are precipitated from their solution by tannic acid, picric acid,phosphomolybdic acid, and by sodium phosphotungstate acidified by acetic, phosphoric, or sulphuric acid. Peptones are the only soluble proteins not precipitated by saturation with ammonium sulphate. The following tabic, showing the reaction of proteoses and peptones, is due to Halliburton:* Variety of Protein. Hot and Cold Water. Hot and Cold Saline Solutions, e.g., io% NaCl. Satura- tion with NaCl or MgS04. Satura- tion with (NH4)2S04 Nitric Acid. Copper Sulphate. Precipitated in cold; pre- cipitate dis- solves with heat and re- Precipi- tated appears on cooling Ditto Precipi- tated This reaction occurs only in presence of excess of salt Not pre- cipitated Not pre- cipitated Not pre- cipitated Copper Sulphate and Caustic Potash. Proto- albumose Hetero- albumose Deutero- albumose Peptone Soluble Insoluble; i.e. precipitated by dialysis from saline solutions Soluble Soluble Soluble Soluble; part- ly precipita- ted, but not c o a g ulated o n heating to 6s° C. Soluble Soluble Precipi- tated Precipi- tated Not pre- cipitated Not pre- cipitated Precipi- tated Precipi- tated Precipi- tated Not pre- cipitated Rose-red color (biu- ret reac- tion) Ditto Ditto Ditto (c) Peptides. — Definitely characterized combinations of two or more amino-acids, the carboxyl group of one being united with the amino group of the other, with the elimination of a molecule of water. The peptones are undoubtedly peptides or mixtures of peptides, the latter term being at present used to designate those of definite structure. B. AMINO-ACIDS, Amides, and Allied products. — Under this head are included products derived from acids or bases, the radicles of which replace one or more of the hydrogen atoms in ammonia. The most common bodies of this class occuring in food products are: (i) Cholin (C5HJ5NO2), found in the muscular tissue of cattle and in yolk of eggs, also in certain fungi. (2) Betaine (CjH^^NOo), found in certain mollusks, as, for instance, the mussel, in putrefying fish, and (in the vegetable kingdom) in beets and hops. It is formed by the oxidation of cholin. (3) Asparagin (C4HgN203), found in the shoots of asparagus, lettuce, peas and beans, and in the root of the marshmallow. It may be crystal- * Chemical Physiology and Pathology, page 131. 46 FOOD INSPECTION AND ANALYSIS. lized out from the expressed juice of the asparagus shoots by evaporation, after having removed the albumin by coagulation (by boiling) and by filtration.* Asparagin when heated with alkalies forms ammonia, and with acids forms ammonium salts. Freshly prepared copper hydroxide is dissolved by an aqueous solution of asparagin by the aid of heat. If sections of vegetable tissues containing asparagin are placed in alcohol, crystals of asparagin are formed in such a manner as to be detected under the microscope. t Closely allied to the amides are the flesh bases of meat, chief among which are creatin (C4HaN302), creatinin (C4H7N3O), derived from crea- tin by the action of mineral acids and existing in some fish, carnin (C^HgN.Og), and xanthin {CJl^S^^). C. Alkaloidal Nitrogen. — Alkaloids do not naturally occur in foods, with the exception of tea, coffee, and kola-nuts, which contain caffeine, and cocoa, which contains theobromine. D. Nitrogen as Nitrates. — Foods in their natural condition rarely contain nitrates. Meats cured with saltpetre furnish the most common instance of nitrates in food. Nitrates are tested for by extracting the sample with water, and treating the extract with ferrous sulphate and sulphuric acid in the usual manner. E. Nitrogen as Ammonia. — Ammonia occurs very sparingly in food, unless the latter has undergone some form of decomposition. In ripened cheese and in sour milk one sometimes finds it in minute quan- tities. Its presence is tested for by distilling the finely divided sample in water free from ammonia, and testing the distillate with Nessler's reagent. F. Lecithin.— This substance (C44H90NPO9) is a . phosphorized fat, and forms a part of the cell material in certain animal and vegetable foods. It is found in considerable quantity in the yolk of egg, and, in traces, in cereals, peas, and beans. It is a yellowish-white solid, soluble in ether and alcohol. Treated with water it swells up, forming an opales- cent solution or emulsion, from which it is precipitated by salts of the alkali metals. The Carbohydrates and their Classification.— The carbohy- drates supplied by food are milk sugar and the various sugars, starches, and gums from plant juices, cereals, fruits, and vegetables. Carbohy- drates are generally understood as being compounds of carbon, hydrogen, and oxygen, the last two elements being present in the proportion in * Zeits. fiir analytische Chemie, 22, page 325. t Wiley, Principles of Agric'l Analysis, Vol. III. p. 427. FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 47 which they occur in water„ They are cHvided into three jnain classes, as follows : A. The Glucose Group, or Monosaccharids (CeHizOg), including dextrose, levulose, and galactose. B. The Cane Sugar Group, or Disaccharids (C12H22O11), including cane sugar, milk sugar, and maltose. C. The Cellulose Group (CeHjoOj), including starch, cellulose, dex- trin, gums, etc. Closely allied to the carbohydrates, if not actually belonging to them, are inosite (CgHijOg), occurring in muscular tissue, and pectose, found in green fruits and vegetables. The Organic Acids. — These acids are minor though important constituents of foods. From their conversion into carbonates within the body, they are useful in furnishing the proper degree of alkalinity to the blood and to the various other fluids, besides being of particular value as appetizers. They exist in foods both in the free state and as salts. Acetic acid is supplied by vinegar; lactic acid by milk, fresh meat, and beer; citric, malic, and tartaric acids by the fruits. Mineral or Inorganic Materials. — These substances occur in food in the form of chlorides, phosphates, and sulphates of sodium, potas- sium, calcium, magnesium, and iron, and are furnished by common salt, as well as by nearly all animal and vegetable foods. The inorganic salts are necessary to supply material for the teeth and bones, besides having an important place in the blood and in the cellular structure of the entire body. Fuel Value of Food. — In order to express the capacity of foods for yielding heat or energy to the body, the term fuel value is commonly used. By the fuel value of a food material is meant the amount of heat expressed in calories equivalent to the energy which we assume the body could obtain from a given weight of that food material, if all of its nutritents were thoroughly digested, a calorie being the amount of heat required to raise a kilogram of water 1° C. This definition applies to what is known as the large calorie, which is one thousand times as large as the small calorie. Large calories are meant wherever the term occurs in this volume. The fuel value, or, as it is sometimes called, "heat of combustion," may be determined experimentally with a calorimeter, or may be calculated by means of factors based on the result of many experiments showing the mean values for protein, fats, and carbohydrates. The Bomb Calorimeter.* — This apparatus in its most approved form, * U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 21, pp. 120-126. 48 FOOD INSPECTION AND ANALYSIS. Fig. 13, consiste of a water-tight, cylindrical, platinum lined, s^eel bombj adapted to hold in a capsule the substance whose heat is to be determined, and containing also oxygen under pressure. This bomb is immersed in water contained in a metal cylinder, which is in turn placed inside of concentric cylinders containing alternately air and water. The heat for igniting the substance is supplied by the electric current passing through wires to the interior of the bomb and acting upon a cleverly devised mechanism therein. The heat developed by the ignition is measured by Fig. 13. — Bomb Calorimeter of Hempel and Atwater the rise in temperature of the water surrounding the bomb, as indicated by a very delicate thermometer graduated to hundredths of a degree, certain corrections being made, as, for instance, for the heat absorbed by the metal of the apparatus. A mechanical stirrer serves to equalize the temperature of the water surrounding the bomb. Calculation 0} Fuel Value. — By reason of its great expense the calo- rimeter is beyond the reach of many laboratories, and on this account the expression of fuel values by calculation is the most common method em- ployed. For this the factors of Rubner are generally used, in accordance with which the amount of energy in one gram of each of the three principal FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 49 classes of nutrients are, for carbohydrates 4.1, for protein 4.1, and for fats 9.3. Expressed in pounds, each pound of carbohydrate or protein has a fuel value of i860 calories, while each pound of fat has a fuel value of 4220 calories. REFERENCES ON DIETETICS AND ECONOMY OF FOOD. \lbu, a., u. Neuberg, C. Mir.eralstoffwechsel. Berlin, 1906. Armsby, H. p. The Principles of Animal Nutrition. New York, 1903. Atwater, W. O. Dietaries in Public Institutions. Yearbook of U. S. Dept. of Agric, 1901, page 393. Food and Diet. Yearbook of U. S. Dept. of Agric, 1894, page 357. Principles of Nutrition and Nutritive Value of Food. Farmer's Bulletin, 142. Bellows, A. J. The Philosophy of Eating. Boston, 1867. Burnet, R. W. Foods and Dietaries. Phil., 1893. Bryant, A. P. Some Results of Dietary Studies in the United States. Yearbook of U. S. Dept. of Agric, 1898, page 439. Chittenden, R. H. The Nutrition of Man. New York, 1907. Physiological Economy in Nutrition. New York, 190/J. Halliburton, W. D. Text -book of Chemical Physiology and Pathology. London, 1891. Hammarsten, O. A Text-book of Physiological Chemistry. New York, 191 2. Hutchinson, Robt. Food and the Principles of Dietetics. New York, 1901. Jaffa, M. E. The Study of Human Foods and Practical Dietetics. Cal. Exp. Sta. Bui. no. Knight, J. Food and its Functions. London, 1895. •LuSK, G. The Science of Nutrition. Philadelphia and London, 1910. Neumeister, a. Lehrbuch der physiologische Chemie. 1897. Pavy, F. W. a Treatise on Food and Dietetics. London, 1874. Richards, E. H. The Cost of Living as Modified by Sanitary Science. New York, 1900. The Cost of Food: A Study in Dietaries. New York, 1901. Rubner, M. Die Gesetze des Energieverbrauchs bei Ernahrung. Leipzig, 1902. Sherman, H. C. Chemistry of Food and Nutrition. New York, 191 1. Strohmer, F. Die Ernahrung des Menschen. Thompson, W. G. Practical Dietetics. New York, 1895. TowNSHEND, S. H. The Relation of Food to Health. St. Louis, 1897. True, A. C, and Milner, R. D. Development of Nutrition Investigations of the Dept. of Agric. Yearbook of U. S. Dept. of Agric, 1899, page 403. Storrs Exp. Station Annual Reports, 1888 et seq. Dietetic and Hygienic Gazette. Hygienische Rundschau. Revue de la Soc. Scientifique d'Hygiene Alimentaire, 1904 et seq. Zeitschrift FxJR Physiologische Cheihe, 1877 et seq. 5 2 FOOD INSPECTION yIND ANALYSIS. Also the following bulletins of the Office of Experiment Stations, U. S. Department of Agriculture. Eul. 21. Methods and Results of Investigations on the Chemistry and Economy of Food. By W. O. Atwater. Pp. 222. Bui. 28. (Revised edition.) The Chemical Composition of American Food Materials. By W. O. Atwater and A. P. Bryant. Pp. 87. Bui. 29. Dietary Studies at the University of Tennessee in 1895. By C. E. Wait, with comments by W. O. Atwater and C. D. Woods. Pp. 45. Bui. 31. Dietary Studies at the University of Missouri in 1895, and Data Relating to Bread and Meat Consumption in Missouri. By H. B. Gibson, S. Calvert, and D. W. May, with comments by W. O. Atwater and C. D. Woods. Pp. 24. Bui. 32. Dietary Studies at Purdue University, Lafayette, Ind., in 1895. By W. E. Stone, with comments by W. O. Atwater and C. D. Woods. Pp. 28. Bui. 35. Food and Nutrition Investigations in New Jersey in 1895 and 1896. By E. B. Voorhees. Pp. 40. Bui. 37. Dietary Studies at the Maine State College in 1895. By W. H. Jordan. Pp, 57- Bui. 38. Dietary Studies with Reference to the Food of the Negro in Alabama in 1895 and 1896. Conducted with the cooperation of the Tuskegee Normal and Industrial Institute and the Agricultural and Mechanical College of Alabama. Reported by W. O. Atwater and CD. Woods. Pp. 69. Bui. 40. Dietary Studies in New Mexico in 1895. By A. Goss. Pp. 23. Bui. 44. Report of Preliminary Investigations on the Metabolism of Nitrogen and Carbon in the Human Organism with a Respiration Calorimeter of Special Construction. By W. O. Atwater, C. D. Woods, and F. G. Benedict. Pp. 64. Bui. 45. A Digest of Metabolism Experiments in which" the Balance of Income and Outgo was Determined. By W. O. Atwater and C. F. Langworthy. Pp. 434. Bui. 46. Dietary Studies in New York City in 1895 and 1896. By W. O. Atwater and C. D. Woods. Pp. 117. Bui. 52. Nutrition Investigations in Pittsburg, Pa., 1894-1896. By Isabel Bevier. Pp. 48. Bui. 53. Nutrition Investigations at the University of Tennessee in 1896 and 1897. By C. E. Wait. Pp. 46. Bui. 54. Nutrition Investigations in New Mexico in 1897. By A. Goss. Pp. 20. Bui. 55. Dietary Studies in Chicago in 1895 and 1896. Conducted with the coopera- tion of Jane Addams and Caroline L. Hunt, of Hull House. Reported by W. O. Atwater and A. P. Bryant. Pp. 76. Bui. 56. History and Present Status of Instruction in Cooking in the Public Schools of New York City. Reported by Mrs. Louise E. Hogan, with an introduction by A. C. True, Ph.D. Pp. 70. Bui. 63. Description of a New Respiration Calorimeter and Experiments on the Conservation of Energy in the Human Body. By W. O. Atwater and E. B. Rosa. Pp. 94. Bui. 68. A Description of Some Chinese Vegetable Food Materials and their Nutri- tive and Economic Value. By W. C. Blasdale. Pp. 48. FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC 51 Bui. 69. Experiments on the Metabolism of Matter and Energy in the Human Body. By W. O. Atwater and F. G. Benedict, with the cooperation of A. W. Smith and A. P. Bryant. Pp. 112. Bui. 71. Dietary Studies of Negroes in Eastern Virginia in 1897 and 1898. By H. B. Frissell and Isabel Bevier. Pp. 45. Bui. 75. Dietary Studies of University Boat Crews. By W. O. Atwater and A. P. Bryant. Pp. 72. Bui. 84. Nutrition Investigations at the California Agricultural Experiment Station, 1896-1898. By M. E. Jaffa. Pp. 39. Bui. 85. A Report of Investigations on the Digestibility and Nutritive Value of Bread. By C. D. Woods and L. H. Merrill. Pp. 51. Bui. 89. Experiments on the Effect of Muscular Work upon the Digestibility of Food and the Metabolism of Nitrogen. Conducted at the University of Tennessee, 1897-1899. By C. E. Wait. Pp. 77. Bui. 91. Nutrition Investigations at the University of Illinois, North Dakota Agricul- tural College, and Lake Erie College, Ohio, 1896-1900. By H. S. Grindley and J. L. Sammis, E. F. Ladd, and Isabel Bevier and Elizabeth C. Sprague. Pp. 4-2. Bui. 98. The Effect of Severe and Prolonged Muscular Work on Food Consumption, Digestion, and Metabolism, by W. O. Atwater and H. C. Sherman, and the Mechanical Work and Efficiency of Bicyclers, by R. C. Carpenter. Pp. 67. Bui. 107. Nutrition Investigations among Fruitarians and Chinese at the California Agricultural Experiment Station, 1899-1901. By M. E. Jaffa. Pp. 43. Bui. 109. Experiments on the Metabohsm of Matter and Energy in the Human Body, 1898-1900. By W. O. Atwater and F. G. Benedict, with the cooperation of A. P. Bryant, A. W. Smith, and J. F. Snell. Pp. 147. Bui. 116. Dietary Studies in New York City in 1896 and 1897. By W. O. Atwater and A. P. Bryant. Pp. 83. Bui. 117. Experiments on the Effect of Muscular Work upon the Digestibility of Food and the Metabolism of Nitrogen. Conducted at the University of Tennessee, 1899-1900. By C. E. Wait. Pp. 43. Bui. 121. Experiments on the Metabolism of Nitrogen, Sulphur, and Phosphorus in the Human Organism. By H. C. Sherman. Pp. 47. Bui. 126. Studies on the Digestibility and Nutritive Value of Bread at the University of Minnesota in 1900-1902. By Harry Snyder. Pp. 52. Bui. 129. Dietary Studies in Boston and Springfield, Mass., Philadelphia, Pa., and Chicago, 111. By Lydia Southard, Ellen H. Richards, Susannah Usher, Bertha M. Terrill, and Amelia Shapleigh. Pp. 103. Bui. 132. Further Investigations Among Fruitarians at the California Agricultural Experiment Station. By M. E. Jaffa. Pp. 81. Bui. 136. Experiments on the Metabolism of Matter and Energy in the Human Body, 1900-1902. By W. O. Atwater and F. G. Benedict. Pp. 357. Bui. 143. Studies on the Digestibility and Nutritive Value of Bread at the Maine Agricultural Experiment Station, 1899-1903. By C. D. Woods and L. H. Merrill. Pp. 77. 52 FOOD INSPECTION AND ANALYSIS. Bui. 149. Studies of the Food of Maine r>umbermen. By C. D. Woods and E. R. Mansfield. Pp. 60. Bui. 150. Dietary Studies at the Government Hospital for the Insane, Washington, D. C. By H. A. Pratt and R. D. Milner. Pp. 170. Bui. 152. Dietary Studies with Harvard University Students. By E. Mallinckrodt, jr. Pp. 63. Bui. 156. Studies on the Digestibility and Nutritive Value of Bread and Macaroni at the University of Minnesota, 1903-1905. By Harry Snyder. Pp. 80. Bui. 159. A Digest of Japanese Investigations on the Nutrition of Man. By K. Oshima. Pp. 224. Bui. 162. Studies on the Influence of Cooking upon the Nutritive Value of Meats at the University of Illinois, 1903-1904. By H. S. Grindley and A. D. Emmett. Pp. 230. Bui. 175. Experiments on the Metabolism of Matter and Energy in the Human Body. 1903-1904. By F. G. Benedict and R. D. Milner. Pp. 335. Bui. 185. Iron in Food and Its Functions in Nutrition. By H. C. Sherman. Pp. 80. Bui. 187. Studies of the Digestibility and Nutritive Value of Legumes at the Uni- versity of Tennessee, 1901-1905. By C. E. Wait. Pp. 55. Bui. 193. Studies of the Effect of Different Methods of Cooking upon the Thorough- ness and Ease of Digestion of Meat at the University of Illinois. By H. S. Grindley. Pp. 100. Bui. 208. The Influence of Muscular and Mental Work upon Metabolism and the Efficiency of the Human Body as a Machine. By F. G. Benedict. CHAPTER IV. GENERAL ANALYTICAL METHODS. Sxtent of a Proximate Chemical Analysis.— For purposes of studying the proximate composition of food for its dietetic value, it is nearly always necessary to make determinations of moisture, ash, fat, total nitrogen, and carbohydrates {when present), as well as of the fuel value. In some cases it may be desirable to proceed further, to make an analysis of the ash, for instance, to separate, at least into classes, the various nitrogenous bodies, especially in flesh foods, and perhaps to subdivide the starch, sugar, gums, and cellulose or crude fiber that make up the carbohydrates in the case of cereals. An analysis is considered complete whenever the purpose for which the examination has been made has been accomplished, and on that pur- pose depends solely the extent to which the various compounds present shall be subdivided and determined. Such a subdivision may be extended almost indefinitely. For example, a milk analysis may consist simply in the determination of the total solids and (by difference) the water. Again, it may be desirable to divide the milk soHds into fat and solids not fat, and in some cases to carry the subdivision still farther and separate the solids not fat into casein, albumin, milk sugar, and ash. Determinations of one or more of the proximate components natural to food are frequently of great service in proving their purity or freedom from adulteration. For the latter purpose, especially in such foods as milk, vinegar, oils, and fats, the determination of specific gravity is also an important factor. Special methods of a peculiar nature are often neces- sary in the examination of particular foods, and such methods will be treated subsequently under the appropriate headings. In the present chapter only such general methods as are applicable to a large variety of cases will be discussed. Expression of Results of a Proximate Analysis.— However complete the division of the various proximate compounds or classes of compounds 53 54 FOOD INSPECTION AND ANALYSIS. which the analyst sees fit to make, the results of his various determina- tions in a proximate analysis are expected to aggregate about ioo%. If every determination be directly made, the result will rarely be exactly IOC, but the precision of the work is apt to be judged by its approach to lOO. It is often the custom to determine certain compounds or classes of compounds by difference. Thus in cereals moisture, Droteins, fat, crude fiber and ash may be determined by the regular analytical methods, and by subtracting their sum from loo the difference may be expressed as "nitrogen- free extract" or carbohydrates. It has long been customary in food analysis to calculate the protein by multiplying the total nitrogen by the factor 6.25, and on this basis analyses of thousands of animal and vegetable foods have been made. WTiile the figure thus obtained is an arbitrary one, being at best but a rough approximation of the amount of protein present, yet for many reasons there is much to commend this practice of reporting results. In the first place, in most cases it actually does approach the truth. Again, the nitiogenous ingredients of many foods are so numerous and varied, that for the ever}^-day study of dietaries and food values it would be well-nigh impossible with our present knowledge to subdivide these compounds with any degree of accuracy, and especially with uniformity between different chemists, to say nothing of the time involved. From the fact that so many valuable analyses have already been expressed on the basis of NX 6.25 for protein, the advantage of comparison with the results thus recorded would seem to be in itself a good reason for continuing the practice, especially until a factor that gives better average results can be adopted. By recording the actual nitrogen found as well as the "protein," old results may at any time be recalculated under new conditions, if found desirable. In flesh foods, when carbohydrates are known to be absent, the total protein may conveniently be determined by difference. Rather more progress has been made in the separation of the nitrogenous compounds of meats than of the vegetables and cereals, though the methods are by no means accurate or uniform. Most of the recorded analyses of vegetable foods express the carbohy- drates as a whole without attempting to subdivide them, at least further than possibly to express the crude fiber or cellulose separately. A much more intelligible idea of the dietetic value of these, foods would be gained by a further separation into starch and sugars. GENERAL ANALYTICAL METHODS. 5S Preparation of the Sample. — It is at the outset of the utmost iniportance in all cases that a strictly representative portion of the food to be examined should be submitted to analysis. All refuse matter, such as bones, shells, bran, skins, etc., are removed as completely as possible from the edible portion and discarded. If the composition of the entire mass cannot be made homogeneous throughout, it may be best to select from various portions in making up the sample for analysis, in order to represent as fair an average of the whole as possible. Finally the sample, if solid or semi-solid, should be divided as finely as possible, by chopping, shredding, pulping, grinding, or pulverizing according to its nature and consistency. For disintegrating such substances as vegetables and meats for analysis, the common household rotary chopping-machine is admirably adapted. For pulverizing cereals, tea, coffee, whole spices, and the like, the mortar and pestle may be used, or a rotary disk mill or spice-grinder. Specific Gravity or Density of Liquids. — Where formerly it was cus- tomary to compare the density of liquids with that of water at 4° C. (its maximum density) it is now more common to refer to water at 15.5° C. or 20° C, making the determination at that temperature. A common form of expressing the temperature of the determination and the tempera- ture of the standard volume of water with which that of the substance is to be compared, is the employment of a fraction, the numerator of which expresses the temperature of the determination and the denominator , , , r i5-S° 15-5° 100° 4° ^^ that of the standard volume of water, as — ^X, 5, 5, -^ C* 4° 15-5 15-5 4° "When extreme accuracy in the determination of density is required, the pycnometer or Sprengel tube should be employed. The Hydrometer. — This instrument furnishes the most convenient and ready means of determining the density of liquids where extreme nicety is not required. If well made and carefully adjusted, the hydrometer may be depended on to three decimal places, but before relying on its accuracy, it should be tested by comparison with a standard instrument, or with the pycnometer. The liquid whose density is to be determined is contained in a jar whose inner diameter should be at least f " larger than that of the spindle- * Unless otherwise stated, all specific gravities ia this volume are assumed to be expressed on the basis of -^•^ 15-5° 56 FOOD INSPECTION AND ANALYSIS. bulb, and the temperature of the liquid should be exactly 15.5° when the reading is taken. For best results for use with liquids of varying densities, the laboratory should be furnished wdth a set of finely graduated hydrometers, each limited to a restricted part of the scale, together with a universal hydrom- eter coarsely graduated, covering the entire range, to show by preliminary test which of the special instruments should be used. A convenient set of seven such hydrometers are graduated as follows: 0.700-0.850, 0.850-1.000, 1. 000-1.200, 1. 200-1. 400, 1. 400-1. 600, 1.600- 1.800, 1.800-2.000, while the universal hydrometer has a scale extending from 0.700 to 2.000. Another less delicate set of three only has one for liquids lighter than water and two for heavier liquids. Some instruments have thermometers in the stem. Others require a separate thermometer. The Westphal Balance (Fig. 14). — This instrument consists of a scale-beam fulcrumed upon a bracket, which in turn is upheld by a sup- porting pillar. The scale-beam is graduated into ten equal divisions. From a hook on the outer end of the beam hangs a glass plummet pro- vided with a delicate thermometer, the beam being so adjusted that when the dry plummet hangs in the air, the beam is in exact equilibrium, i.e., perfectly horizontal as shown by the indicator on its inner end. If the large rider be placed on the same hook as the plummet and the latter immersed in distilled w^ater of the standard temperature at which the determinations are to be made (say 15.5° C), the scale-beam should again be in equihbrium if the instrument is accurately adjusted.. As commonly made, the weight of the plummet including the platinum wire to which it is attached amounts to 15 grams, and the displacement of its volume to 5 grams of distilled water at 15.5° C, the normal temperature on which the determinations are based. Thus the unit (or largest) rider should weigh 5 grams, while the others weigh 0.5, 0.05, and 0.005 gram respectively. If, instead of distilled water, the plummet be immersed in the liquid whose density is to be determined, the position of the riders on the scale- beam, when so placed as to bring the same into equihbrium, and when read in the order of their relative size (beginning at the largest), indicates directly the specific gravity to the fourth decimal place. If the hquid is lighter than water, the large rider is first placed in the notch where it comes closest to restoring the equihbrium of the beam, but with the plummet still underbalanced. The rider next in size is then apphed in a similar manner, and, unless equilibrium is exactly re- GENER/iL ANALYTICAL METHODS. 57 Stored, the third and the fourth riders successively. If it happens that two riders should occupy the same position on the beam, the smaller is suspended from the larger. If the hquid is heavier than water, the method employed is the same except that one of the largest or unit riders is in this case always hung from the hook which supports the plummet, while the others cross the Fig. 14. — ^The Westphal Balance. beam at the proper points. If carefully made and adjusted, the Westphal balance is capable of considerable accuracy. A delicate analytical balance can be used in place of the less carefully adjusted Westphal instrument, by hanging the Westphal plummet from one of the scale-hooks of the same, and employing a fixed support for the glass jar that holds the liquid in which the plummet is to be immersed. The support is so arranged that the scale-pan below it can move freely without coming in contact with it. This arrangement is shown in Fig. 15. The Pycnometer, or Sped fie- gravity Bottle. — Fig. 16 shows the two 58 FOOD INSPECTION AND ANALYSIS. forms of pycnometer commonly made. The plain form has a ground- glass stopper with a capillary passage through it, the other has a fine ther- mometer connected with the stopper and a capillar}^ side tube provided with a ground hollow cap. Both are made in different sizes to hold respectively lo, 25, 50; and 100 grams of distilled water at the standard Fig. 15. — The Analytical Balance Arranged for Determining Specific Gravity witli the Westphal Plummet. temperature. It is convenient to have a counterweight for each pycnom- eter as fitted with its stopper, thus avoiding much trouble in calculation. The calculation of results is simplified also if the pycnometers arc accurately constructed to contain exactly the weight of distilled water which they purport to contain at the standard temperature, but it is rather difficult to procure such instruments, especially of the form furnished with the ther- mometer. Most instruments hold approximately the amount specified, the exact net weight of distilled water which they hold at standard tem- perature being found by careful test and kept on record. In determining the density of a liquid, the pycnometer is carefully filled with it at a tem- perature below the standard, the stopper carefully inserted, and the bottle wiped dry. Care should be taken that the liquid completely fills the bottle and is free from air-bubbles. The net weight of the liquid is then taken GENERAL ANALYTICAL METHODS. 59 on the balance, when the temperature has reached the standard (say 15.5° C), being careful to wipe off the excess of Hquid that exudes from the capil- lary due to expansion. The net weight of the hquid is divided by that of the same volume of distilled water, previously ascertained under the same conditions at the same temperature, the result being the density of the liquid. The pycnometer with thermometer attachment is obviously susceptible of a greater degree of accuracy than the other form, since the temperature of the liquid, even though 15.5° C. at the start, soon rises. r\ Fig. 16. — Types of Pycnometer. The writer prefers to use the pycnometer provided with the ther- mometer, but without the hollow cap that covers the capillary side tube, unless liquids like strong acids are to be operated on, that might other- wise injure the balance. By keeping the Hquid to be tested for some time in a refrigerator, it acquires a temperature of from 10 to 12° C. It is then transferred in the regular manner to the pycnometer and the ther- mometer-stopper inserted (but not the hollow cap) and the bottle wiped dry. There is ample time to adjust the balance-weights with extreme care while the temperature of the hquid is rising, leisurely wiping off Co FOOD INSPECTION AND ANALYSIS. at inten^als with a soft towel the excess that exudes from the capillary tube, the final weight of the dry bottle and contents being made at the exact temperature of 15.5° C In taking the tare or adjusting the counterweight of a specific-gravity bottle, the latter should be perfectly clean and dry. It had best be rinsed first with water, then with alcohol, and finally with ether, all traces of the latter being removed by a current of dry air, or otherwise, before weighing. In making successive determinations of density of a number of different liquids with the same pycnometer, it is sufficient to rinse the bottle once with a little of the liquid to be tested before making each determination, when the various liquids are miscible. When the liquids are immiscible, the bottle should be carefully cleaned in the manner described in the previous paragraph before making each test. The Sprengel Tube. — The Sprengel tube is a variety of pycnometer useful when only a small quantity of the liquid to be tested is available. It is susceptible of great accuracy. It consists of a U-shaped tube (Fig. 17), each branch of which termi- nates in a horizontal capillary tube bent outward. One of the capillaries, h, has a mark m thereon and has an inner diameter of about 0.5 mm. The diameter of the other capillary, a, should not exceed 0.25 mm. The liquid at room temperature is as- pirated into the tube so as to fill it completely, the end h being dipped in the liquid while suction is applied at the end a. The tube is then placed in a beaker of water kept at the standard temperature, the beaker being of such size that the capillary ends rest on the edge. The temperature of the liquid in the tube may be assumed to be constant j^G. 17.— Sprengel Tube when there is no further movement due to contrac- for Determining Spe- tion in the larger capillary end, h. The meniscus of cific Gravity. ^^^ liquid, when cooled, should not be inside the mark m, and is brought exactly to the mark by applying a piece of bibulous paper to the other end, a. If a drop or two of hquid has to be added, this may be done by applying to the end a a glass rod dipped in the Hquid. When exactly adjusted, the whole is wiped dry and quickly weighed, hung from the arm of the analytical balance. To avoid evaporation by contact with the air, the ends of the capillaries are sometimes ground to receive hollow glass caps not shov/n in the figure. GENERAL ANALYTICAL METHODS. 6i Determination of Moisture.— This is usually calculated from the loss in weight at the temperature of boiling water. Platinum dishes (Fig. 51) are well adapted for the drying as the residue can be ignited for the determination of ash. If only the moisture is desired, dishes of other metals or glass weighing bottles may be used. Caps for wide- mouthed bottles made of tinned lead are convenient and can be thrown Fig. 18. — Apparatus for Drying in Hydrogen. ' away after using. Viscous substances are best spread over asbestos or sand to hasten the drying. Some materials must be heated above 100° C, while certain saccharine products are dried at 70° C. in vacuo to avoid decomposition. If alcohol, acetic acid, essential oils, or other volatile substances are present the loss includes these as well as moisture. As the water or steam oven seldom attains a temperature above 98°, the loss sustained in these is, strictly speaking, at the "temperature of boiling water." Figs. 8 and 9 show electric and gas ovens for heating at full 100°. Benedict has shown that certain materials can best be dried at room-temperature over sulphuric 62 FOOD INSPECTION ^ND ^N^ LYSIS. acid in vacuo. Trowbridge * has shortened this process in the case of meat, by gently agitating the desiccator during the drying. Drying in Hydrogen. — Fig. i8 shows the apparatus devised by Winton f for drying cereal products, cattle foods, etc. (p. 276). The material is weighed out on a watch glass and transferred to the drying tube (G), wisps of cotton, too small to contain an appreciable amount of moisture, being used at both ends to prevent mechanical loss. The hydrogen is purified by passing through sodium hydroxide solution (A) and dried by sulphuric acid in the jar (B). The acid drops over the glass beads into the chamber at the bottom of the jar where the gas bubbles through it before passing out over the beads. A siphon automatically removes the excess of acid. The drying tubes pass through the cop- per tubes of the water oven and are fitted at the posterior ends with capillary exit tubes of 0.5 mm. bore, thus creating a slight pressure and insuring even distribution of current. When the drying is begun the exit tubes should be within the copper tubes to avoid stoppage of the current by condensed moisture, but later they should be pushed out, as in the cut, and each tested by lighting. Determination of Ash.^ — The residue from the determination of moisture or else a new portion, is burned at a very faint red heat until white or gray, cooled in a desiccator and weighed. A fiat-bottomed platinum dish is most convenient for the purpose. Platinum, however, is attacked by free chlorine, bromine, and iodine, sulphur and phosphorus, sulphates and phosphates with reducing agents, all sulphides, sodium or potassium hydroxide, nitrate and cyanide, metals, and metallic compounds reduced in fusion, such as lead, tin, zinc, bismuth, mercury, arsenic, and antimony. In such cases porcelain must be used. The degree of heat employed in ashing should be the lowest possible to Fig. 19. — ^Hoskins Electric Furnace. * A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 219. t Conn. Agr. Exp. Sta., Rep. 1889, p. 187. GENERAL ANALYTICAL METHODS. 63 insure complete oxidation of the carbon, so as to avoid driving off certain volatile salts that are sometimes present and that would be lost if the heat were too high. At a bright red heat potassium and sodium chloride are slowly volatilized, and calcium carbonate is converted into oxide; further- more alkali phosphates fuse about particles of carbon, protecting them from oxidation. To avoid overheating it is recommended not to allow the flame to impinge directly against the dish, but to carry out the burn- ing on a piece of asbestos paper supported on a triangle. The asbestos also serves to distribute the heat and to protect the dish from the injurious action of the direct flame on long heating. In order to burn off the last traces of carbon, a second piece of asbestos paper may be placed over the top of the dish, or the incineration may be completed in a gas or electric muffle furnace (Figs. 3 and 19). Heating should be con- tinued tin the carbon is aU oxidized, which is in most cases indicated by a white ash. It is, however, sometimes impossible to obtain a perfectly 'white ash, but the appearance of the ash usually indicates when aU the carbon has been burnt off. It is sometimes necessary to stir the contents of the dish with a stiff platinum wire from time to time during the ignition. Methods for the detection and determination of the various ash ingre- dients are considered on pages 301 to 305. Such cases as are pecuHar to certain foods, like the metallic impurities that occur in canned, bottled, and preserved foods under certain conditions, wfll be considered in their appropriate place. Extraction with Volatile Solvents. — Whenever it is necessary to exhaust a substance of its ether-soluble or alcohol-soluble ingredients, some form of continuous extraction apparatus is employed with ad- vantage. Preliminary Drying. — In the case of cereal, legume, and oil-seed products, meats, etc., the portion of the material dried in hydrogen, in vacuo, or in contact with air in an ordinary oven, for the determina- tion of moisture, may be used for extraction. If volatile oil is present, as in spices, the drying must be performed at room temperature in a desiccator. Milk and other liquids are absorbed in a roll of bibulous paper, in asbestos, or in sand, previous to drying (page 134). The evaporation may be carried on in shells of thin glass (Hoffmeister Schalchen) which are finally broken previous to extraction, or in tinned lead bottle caps which may be crumpled up and inserted in the extractor. 64 FOOD INSPECTION AND /iN A LYSIS. The Soxhlet Extractor. —This apparatus is shown in Fig. 20. The substance to be extracted is subjected to successive treatment with freshly distilled portions of the solvent in the tube A. Dry powders are contained in extraction thimbles of filter paper or in filters folded over the end of a flat-bottomed cylinder so as to form a cartridge; liquids, such as milk, previously dried in a paper coil or in a wad of asbestos, are extracted without a filter. The vapor from the solvent, boiling in the L- '^^ flask C, passes up through the side tube a' I J'^^il into the condenser^, where it is liquefied and falls drop by drop on the substance. When the level of the solvent in the tube A reaches the top of the siphon the liquid drains off into the tared flask C, carrying with it whatever it dissolves. The operation is automatically repeated, the substance being successively extracted with freshly distilled portions of the solvent, which leaves behind in the flask C the material in solution. The heater employed should be a hot plate heated by steam, or, as shown in Fig. 20, an electric stove, which may be provided wdth a fractional rheostat for varying the amount of heat. If neither of these is available the extraction flask may be rested on a piece of asbestos paper supported by a lamp stand, the heat being supplied by an ordinary Bunsen burner. The degree of ebullition is so regulated as to allow the solvent to saturate the sample and siphon over into the flask C from six to twelve times an hour, the extraction being continued from two to six hours, or until all the ether-soluble material has been removed. Care should be taken also that the rate of boiling and the rate of condensation are so regulated that no appreciable loss of reagent occurs during the extraction. A strong smell of ether perceptible at the top of the condenser indicates a loss. The solvent is recovered at the end of the extraction by disconnecting the weighing flask at a time when nearly all of the solvent is in the part A and before Fig. 20. — The Soxhlet Extractor with Electric Heater. GENERAL XNALYTICAL METHODS. 65 it is ready to siphon over. The weighing-flask is then freed from all traces of the solvent by drying first on the water-bath and then in the oven, after which it is cooled in the desiccator and weighed, the difference between this and the first weighing representing the weight of the fat or ether extract. The Johnson Extractor. — This form of apparatus (Figs. 21 and 22) has the advantage of the Soxhlet extractor in that it is simpler and employs a much smaller amount of ether. The substance is contained in the inner tube of the extractor (Fig. 21), which is closed at the lower end by one thick- ness each of filter paper and cheese cloth, held tightly in place by means of a linen thread" wTapped several times about the tube in the constriction and tied in a fast knot. This innner '.ube properly prepared can be used over and over for extractions. The t^i- outer tube, also shown in Fig. 21, is of such a size that the inner tube fits loosely within it. A slight bulge on one side prevents trapping by means of the condensed solvent. The extraction fiask is preferably of only 30 to 35 cc. capacity. It is attached to tlie extractor, as is also the extractor to the condenser tube, by means of a carefully bored cork stopjier. For ordinary determinations of ether extract the outer tube should have an inside diam- eter of 2() mm. and the inner tube an outside diam- eter of 22 mm, only 8 to 10 cc. of the solvent being required. If, however, large amounts of material fig. 21. Johnson Extrac- (25 to 50 grams^ are to be extracted, the diameters iionTuoes. may be made 32 mm. and 28 mm. respectively and a larger amount of sol- vent employed. Where only a few extractions are made, the heating can be performed over (but not on) a metal plate heated by a Bunsen burner, and the conden- sation effected by an ordinary Liebig condenser. If, however, a considerable number of extractions are carried out, the set apparatus shown in Fig. 22 will be found convenient and also economical of space. It may be attached to the wall or placed at the back of a working desk. The heating, as shown in the cut, is cfi"ected by means of two steam pipes, but some form of elec- tric heater answers equally well. The case with glazed door prevents the radiation of heat. At the top is shown the multiple condenser consisting C6 FOOD INSPECTION JND yINALYSIS. of a copper tank with block tin tubes. Water is introduced at the k'ft and carried off at the right. The solvent is best poured through the material, thus obviating in large degree the crawling of the extract. The door should be opened several times during the extraction and kept open for a few minutes for the pur- FiG. 22. — Johnson Multiple Extraction Apparatus with Heating Closet and Condenser. pose of rinsing down the sides of the tubes by means of the condensed vapors. Preparation of Solvents.— In taking the so-called ether extract, some- times reckoned as fat, the solvent employed is either ethyl ether O'* the cheaper petroleum ether. Whichever reagent is employed, certain precautions are necessary for the purity of the reagent. If ethyl ether is used, it should be entirely freed from moisture and alcohol by first shaking with water to remove the larger portion of the alcohol, allowing it to stand for some time over dry calcium chloride, and then distilling over metallic sodium. The ether thus prepared should be kept till used with sodium in the container, the latter being somewhat loosely corked, to allow escape of the hydrogen formed. Petroleum ether is variously termed benzine, naphtha, or gasoline. It should be low-boiHng, preferably between 35° and 50°, and it is always best to redistil it before using, in order to be sure it is free from residue. As to the choice of the two reagents for use in fat extraction, it may be said that ethyl ether is the solvent most used, but if a large number of determinations are to be made, the lower cost of petroleum ether is to GENERAL ANALYTICAL METHODS. 67 Fig. 23.— Fractionating-still, Arranged for Petroleum Ether. Fig. 24. — A Convenient Form of Separatory Funnel. 6S FOOD INSPECTION AND ANALYSIS. be considered. A convenient still for fractionating such substances as petroleum ether is shown in Fig. 23. Extraction with Immissible Solvents. — It is frequently necessary to dissolve out a substance from a liquid by shaking it with an immiscible solvent, as, for example, in the extraction of certain preservatives from aqueous or acid solutions with ether, petroleum ether, or chloroform. This can be done by shaking in ordinary flasks, but is attended by some difficulty and loss on decantation. A separatory funnel of the type shown in Fig. 24 is almost indispensible for this kind of extraction. The liquid Fig. 25. — Separatory Funnel Support. and solvent are transferred to the funnel, which is then stoppered and shaken. If the solvent is heavier than water, as in the case of chloroform, it is drawn off fronji beneath through the outlet-tube of the funnel, or, if the solvent is the lighter, as in the case of ether, the aqueous liquid lying beneath is first drawn off and finally the solvent is poured out through the top. If troublesome emulsions form when shaken, they may frequently be broken up by adding an excess of the solvent and again very gently shaking, or by careful manipulation with a stirring rod, or by centrifug- Lag. If the solvent is ether, and an obstinate emulsion forms, it may frequently be broken by the addition of chloroform. Such a mixture of ether and chloroform sinks to the bottom and may be drawn off as in the case of chloroform alone. GENERAL /ANALYTICAL METHODS. 69 A separatory funnel support, devised by Win ton, is shown in Fig. 25. It serves for holding the separatory funnels while drawing from one into another, and also as a support for ordinary funnels. The two shelves are adjustable by means of thumbscrews. The holes in these shelves are somewhat wider than the slots, so that the separatory funnels after being introduced through the latter drop into position and are held firmly while manipulating the stop-cock. Winton attaches all stop-cocks and stoppers to the funnel by means of small brass chains, thus preventing breaking and interchange of these parts during washing. Determination of Nitrogen by Moist Combustion. — In thus determin- ing nitrogen, the organic matter is first decomposed by digestion with sulphuric acid and an oxidizer, the carbon and hydrogen being driven off as carbon dioxide and water respectively, while the nitrogen is converted into an ammonium salt, from which free ammonia (NH3) is later liberated by making' alkaline. The ammonia is then distilled into an acid solution of known value and calculated by titrating the excess of acid. In the Kjeldahl process the oxidation is effected by means of a mercury compound, in the Gunning method, by potassium sulphate which forms the bisulphate with the acid. Neither method in its simplest form is applicable in the presence of nitrates; if these are present, a modification must be used. The Gunning- Arnold method (page 432) is employed for the determination of nitrogen in pepper, as the piperin is not completely decomposed by the usual .processes. The Gunning Method. — Reagents: Standard alkali solution, N/io NaOH.* Pulverized potassium sulphate. Sulphuric acid, concentrated. Sodium hydroxide, saturated solution. Standard acid solution, N/io H2SO4 or HCl.* An indicator, cochineal. Granulated zinc. * Winton employs standard acid of such a strength that i cc. is equivalent to 1% of nitrogen, working on a gram of material, and titrates back with standard alkali two and one-half times weaker than the acid. In order to insure accurate readings, burettes of narrow bore (i cc.= 2.6cm.) are employed. The alkali burette is so graduated that a reading of i corresponds to 2.5 cc, thus allowing for the greater dilution. The advantage of this system is that the per cent of nitrogen is obtained by simply subtracting the alkali reading from the number of cc. of acid employed. 70 FOOD INSPECTiON AND ANALYSIS. The digestion and distillation are preferably carried out in the same flask, which should be pear-shaped with flat or round bottom and made of moderately thick Jena glass. A convenient size has the following dimen- sions: length 29 cm,, maximum diameter 10 cm., tapering gradually to a long neck, which near the end is 28 mm. in diameter with a flaring edge. Its capacity is about 550 cc. If desired, the digestion may be conducted in a smaller hard-glass flask of about 250 cc. capacity and of the same shape as the above, and the distillation in an ordinary round-bottomed flask cf 500 cc. caipacity. Introduce from 0.5 to 3.5 grams of the sample into the digestion-flask with 10 grams of potassium sulphate and from 15 to 25 cc. of concentrated sulphuric acid. The flask is inclined over the flame and heated gently for a few minutes "below the boiling-point of the acid till the frothing has ceased, after whicTi the heat is gradually increased till the acid boils, and the boiling is continued till the contents have become practically colorless or at least of a pale straw color. Wire gauze may be interposed between the flask and flame, but a triangle or a similiar support is to be preferred. The contents of the flask are then cooled, and, if the digestion has been conducted in the larger flask suitable also for distilhng, as above recommended, 300 cc. of water are added and sufficient strong sodium hydroxide to make the contents strongly alkaline, using phenolphthalein as an indicator. If a separate flask is used for the distillation, the contents of the digestion-flask are transferred thereto with the water and the alkali added. A few pieces of granulated zinc should also be introduced, which by the evolution of gas prevents bumping and the sucking back of the distillate. The flask is then well shaken and connected with the con- denser, the bottom of which is provided with an adapter, dipping below the surface of the standard hydrochloric or sulphuric acid, a measured quantity of which is contained in the receiving-flask. The distillation is then continued till all the ammonia has passed over into the acid, this part of the operation requiring from forty-five minutes to an hour and a half. As a rule the first 250 cc. of the distillate will contain all the ammonia. The excess of acid in the receiving-flask is then titrated with standard alkali, and the amount of nitrogen absorbed as ammonia is calculated. The reagents, unless known to be absolutely pure and free from nitrates and GENERAL ANALYTICAL METHODS. 71 ammonium salts, should be tested by conducting a blank experiment with sugar, by means of which any nitrates present are reduced. Any nitrogen due to impurities should be corrected for. In purchasing sulphuric acid for nitrogen determination it is important to specify that it be "nitrogen-free" as the so-called chemically pure acid often contains a considerable amount of nitrogen. Modification of Gunning Method to include Nitrogen of Nitrates. — In addition to the reagents used in the simpler Gunning method, sodium thiosulphate and salicyhc acid are required. A mixture of salicylic and sulphuric acids is made in the proportion of 30 cc. of concentrated sulphuric to i gram of salicylic. From 30 to 35 cc. of Fig. 26. — Bank of Stills for Nitrogen Determination by Gunning Process. the mixture are added to the 0.5 to 3.5 grams of the substance in the di- gestion-flask, the flask is well shaken and allowed to stand a few minutes. 72 FOOD INSPECTION AND ANALYSIS. occasionally shaking. Then 5 grams of sodium thiosulphate are added, and ID grams of potassium sulphate, after which the heat is applied, at first very gently and afterwards increasing slowly till the frothing has ceased. The heating is then continued till the contents have been boiled practically colorless. From this point on, proceed as in the Gunning method. The Kieldahl Method. — One gram of the air dry substance, or a propor- tionately larger amount of a moist or liquid substance, and 0.7 gram of mercuric oxide (or an equivalent amount of metallic mercury) are placed L_ Fig. 27a. — Johnson Digestion Siand forNitrogen Determination with Lead i'ipc i h C -irv. off Fumes. in a 550 cc. Jena flask and 20 cc. of sulphuric acid added. The flask is placed in an inclined position over a Bunsen burner, and the mixture heated below boiling for 5 to 15 minutes or until the frothing ceases, after which the heat is raised until the mixture boils briskly. The boiling is continued until the liquid has become nearly colorless and for a half hour in addition. The lamp is then turned out, the flask placed in an upright position, and potassium permanganate slowly added with shaking until the solution takes on a permanent green or purple color. After cooling, 250 cc. of water are added, then 25 cc. of potassium sulphide solution (40 grams of the commercial salt in i liter of water), GENERAL ANALYTICAL METHODS. 73 sufficient saturated sodium hydroxide solution to render the solution alkaline, and finally a few grains of granulated zinc, shaking the flask after each addition. Without delay connect with the distillation appa- ratus, and proceed as in the Gunning method. Apparatus for Nitrogen Determination. — A bank of stills used by the author in nitrogen determination and in other processes is shown in Fig. 26. The digestion apparatus shown in Fig. 27a is that devised by Johnson, Winton, and Boltwood. The stand is of cast iron, with holes provided Fio. 276. — Johnson Distilling Apparatus for Nitrogen Determination. with three projections that support the flask. The lead pipe with holes for receiving the ends of the flasks serves to carry off the acid fumes. The Johnson distilling apparatus with accessories by Winton is shown in Fig. 2 76. The distillation tubes, except for the glass traps and bulb receiver tubes, are of block tin, and are cooled in a copper tank filled with water. The receivers for the distillate are ordinary pint milk bottles. At the left are two bottles with suspended tubes for measuring the potassium sulphide and sodium hydroxide solutions. 74 FOOD INSPECTION AND ANALYSIS. Determination of Ammonia. — A weighed quantity of the finely divided sample, treated with ammonia-free water and made alkaline with magnesium oxide free from carbonate, is distilled into a measured quan- tity of standard acid (tenth-normal hydrochloric or sulphuric acid) and the amount of ammonia determined by titration. Determination of Amido-nitrogen.* — In the absence of ammonia, or after the removal of the ammonia as described in the preceding section, the sample is boiled for an hour with 5% hydrochloric or sulphuric acid, which converts the amido-compounds into ammonium salts (chloride or sulphate). Assuming asparagin to be the amido-compound acted upon, the reaction is as follows: 2C,H3N203+ H,SO,+ 2H2O = (NHj3SO,4- ^C.H.NO,. Asparagin Ammonium Aspartic acid sulphate Exactly neutralize the free acid with sodium carbonate, add magnesia (free from carbonate), and distil into standard tenth-normal acid. The ammonia is determined by titration in the usual manner, and its nitrogen represents half of the nitrogen contained in the amido-compound, which it is customary to calculate as asparagin. Determination of the Various Carbohydrates. — Under title of " Cereals" in Chapter X are given in detail methods for separation and determination of sugar, dextrin, crude fiber, etc. Detection of Poisons. — MetalHc impurities present in foods incidental to their preparation, or as adulterants, are considered under title of foods liable to such adulteration. The detection of highly toxic substances, such as arsenic, corrosive sublimate, and alkaloids, added with criminal intent, comes within the province of the medico-legal chemist or toxicologist and is beyond the scope of this work. The methods involved are fully described in the treatises of Autenrieth and Blyth (see p. 79), only those for arsenic, which occurs also as an accidental impurity, being here considered. Detection and Determination of Arsenic. — Methods of Solution. — Syrups, baking powders and other materials soluble in water or acid do not need preliminary treatment. Beer is treated as described on page 728. Other methods of solution are as follows: I. J ohnson-Chittenden-Gautier Method. -\ — This method is suitable for meat, vegetables, and the like, the proportion of acids used being * Wiley, Agricultural Analysis, Vol. III. p. 424. t Am. Chem. Jour., 2, p. 250. GENERAL ANALYTICAL METHODS. 75 varied to suit conditions. Heat at i5o°-i6o° C, in a porcelain dish, loo grams of the finely divided material with 23 cc. of pure concentrated nitric acid, stirring occasionally. Wlien the mixture assumes a deep orange color, remove from the heat^ add 3 cc. of pure concentrated sul- phuric acid, and stir while nitrous fumes are given off. Heat to 180° and add while hot, drop by drop, with stirring, 8 cc. of nitric acid, then heat at 200° till sulphuric fumes come off and a dry charred mass remains. Pulverize the mass, exhaust with hot water, filter, evaporate to small volume, take up in cold 20% sulphuric acid and treat by the modified Marsh or Gutzeit method. 2. Sanger Method.^ — Digest at room-temperature for some hours 5 to 20 grams of the material in a casserole with about an equal bulk of Fig. 28. — Marsh Apparatus for Arsenic. concentrated nitric acid, add 20 cc. of concentrated sulphuric acid and digest further at a gentle heat until the mixture begins to char. Add about 2 cc. of nitric acid and heat until sulphuric fumes appear, repeating the addition of acid and heating until oxidation appears to be practically complete. Remove all nitric acid by dilution and evaporation to the fuming stage, then dilute with 4 volumes of water. At this point about twice the bulk of saturated sulphurous acid solution may be added and the evaporation repeated, thus reducing to the arsenious condition, but this is not usually necessary. Methods of Determination. — i. Marsh Test. — The apparatus (Fig. 28) consists of a generating flask with funnel tube, a U-tube containing cotton * Proc. Am. Acad. Arts, Sci., 26, 1891, p. 24. 76 FOOD INSPECTION AND ANALYSIS. B moistened with io% lead acetate solution (to remove hydrogen sulphide), a calcium chloride drying tube, and a hard glass tube of 6 mm. bore, drawn down near the end to a uniform constriction about 4 cm. long and i mm. inside diameter and also at the very end to a narrow exit tube. The tube is sup- ported over a three-burner furnace the part in contact with the flame being wrapped with wire gauze. Introduce into the generating flask from 20 to t,o grams of arsenic-free stick zinc and a perforated platinum disk to form an electric couple. Stopper and add through the funnel tube 2cf^ sulphuric acid sufficient to start the reaction and drive out all air. Wlien danger of explosion is over heat the tube to bright redness. After running the current long enough to prove the absence of arsenic in the reagents add slowly from the funnel tube the solu- tion of the material in 20% sulphuric acid or the solu- tion obtained by one of the foregoing methods containing about 20^ of that acid, keeping a steady evolution of gas. When the flow slackens add 30*^^ sulphuric acid and later 40% acid until ah arsenic has been expelled, which usually requires 2 to 3 hours. If no arsenic mirror forms in the constriction of the tube in one hour, further test may be abandoned. If more than o.i mg. of arsenic appears to be present cut off the constriction from the tube and weigh it on an assay balance ; then dissolve the arsenic in a solution of sodium hypochlorite, (antimony being insoluble), wash with water and then with alcohol, dry, cool, and weigh. The loss is arsenic. If the amount of arsenic is very small Sanger com- pares the mirror with a series of standard mirrors pre- pared in the same apparatus using quantities of a stand- ard solution containing from 0.005 to 0.05 mg. of AS2O3. To prepare the standard solution i gram of pure AS2O3 is dis- solved in arsenic-free sodium hydroxide, acidified with sulphuric acid, made up to one liter and 10 cc. of this stock solution further diluted to I liter; i cc. = o.oi mg. AS2O3. 2. Sanger -Black-Gutzeit Method.*— The apparatus (Fig. 29), devised by Bishop, consists of a 30 cc. salt-mouth bottle provided with three upright * Jour. Soc. Chem. Ind., 26, 1907, p. 11 15. Fig. 29. — Bishop Apparatus for Arsenic. GENERAL ANALYTICAL METHODS. 77 tubes one^above the other. The lower tube is 7 cm. long, i cm. in bore, and contains strips of filter-paper previously soaked in 5% lead acetate solution and dried. The middle tube is of the same size as the lower but shorter. It is loosely filled with cotton moistened with i*^^, lead acetate solution. The upper tube has a uniform bore of 2.5 mm. and is bent twice so that the upper end is vertical. In this tube is placed a strip of cold-pressed drawing paper 2 mm. wide which has been soaked in 5*^^ alcoholic mur- curic chloride (or bromide) and dried. Place in the evolution bottle 10 grams of stick zinc, a few crystals of stannous chloride, a perforated platinum disk and from 2 to 5 grams of the material or else the extract of the charred or digested material pre- pared as described in the foregoing sections, containing about 20% of sulphuric acid. Add enough 20*^^: (1:4) sulphuric acid to nearly fill the bottle, attach the three tubes and allow to react for 45 minutes. Com- pare the color on the sensitized strip with that of standard strips obtained with from 0.005 to 0.05 mg. of AS2O3 in the same apparatus, using measured quantities of the standard solution described under the Marsh test. Colorometric Analysis. — Certain analytical processes depend on the formation of a compound of the substance to be determined having a definite color, and the calculation of the quantity present from the inten- sity of the color of the solution, compared with that of a solution contain- ing a known amount. The comparisons may be made in a special form of cylinder or in a colorimeter. The latter has the advantage that a single solution of known strength serves within reasonable limits for matching any shade in the unknown solution, and for any number of determina- tions, the desired depth of the color being secured by varying the length of the column, Schreiner's Colorimeter.* — This apparatus, shown in Fig. 30, consists of two graduated tubes {B), containing the standard and unknowm colori- metric solutions, the height of the column of liquid in both tubes being changed by two immersion tubes {A), which remain stationary while the graduated tubes are raised or lowered in the clamps (C). The mirror D reflects the light through the tubes, and the mirror E reflects it again to the c)'e of the operator at F. In making the comparisons, the tube containing the solution of either known or unknow^n strength is set at a definite point, and the other tube is raised or lowered until the colors match. If R is the reading of the standard solution of the strength 6", and r the reading of the colorometric solution of unknown strength s, then s = —S. r * Jour. Am. Chem. Soc. 27, 1905, p. 1192. 78 FOOD INSPECTION ^ND /iN A LYSIS. If desired, standard slides of colored glass, such as accompany the Lovibond tintometer, may be used at G for matching the solution of un- known strength, the value of these slides being determined by comparison with a standard solution. The Lovibond Tintometer may be used for colorometric chemical analysis, but is not so well suited for this purpose as the Schreiner colorimeter, it is especially designed for deter- mining the color value of liquid and solid technical products, such as beer, wine, oil, flour, paper, etc. The instrument itself is of simple construc- tion, consisting of an elongated box with an eyepiece at one end and two rectangular openings at the other, one for the solution or substance to be examined, the other for the standard glass slides used for matching the color. Light is reflected through the openings by means of a square piece of opal glass mounted on a jointed standard. Liquids are examined in rectangular cells with glass sides by transmitted light, while powders are pressed into a form and examined by reflected light. Fig. 30. — Schreiner's Colori- meter with a Tube showing Graduation. The standard slides used in general work are red, yellow, and blue in even graduation from .006 to 20 tint units which can be combined so as to produce any desired tint or shade of any color. The results are expressed in terms of standard dominant colors (red, yellow, and blue), subordinate colors (orange, green, and violet) obtained by combining equal values of two dominant colors, and neutral tint (black) obtained by combining equal values of the three dominant colors. Thus o.67?+5.6F-o.60 + 5.oF o.o8i?+ 1. 57 + 0.2^ = 0.08 A^ + o.i2G+i.3F -L.2R+i.oB^i.oV + o.2R in which /? = red, F= yellow, 5 = blue, = orange, G = green, F= violet, JV== neutral tint or black. GENERAL ANALYTICAL METHODS. ' ' 7^ ^^ Special slides may be obtained for the examination of any desired product. For example, slides of brown shades are furnished for beer, of yellow shades for oils, and so on. REFERENCES TO GENERAL FOOD ANALYSIS. Allen, A. H. Commercial Organic Analysis. Philadelphia, 1909. AuTENRiETH, W. The Detection of Poisons and Strong Drugs. Trans, by W. H. Warren. Philadelphia, 1905. Balland, a. Les Aliments. Paris, 1907. Battershall, J. P. Food Adulteration and its Detection. New York, 1887. Bell, Jas. The Analysis and Adulteration of Foods, Pts. I and II. London, 1881. Blyth, a. W. and M. W. Foods, their Composition and Analysis. New York, 1903. — Poisons, their Effects and Detection. London, 1906. BoHMER, C. Die Kraftfuttermittel, ihre Rohstoffe, Herstellung, Zusammensetzung, etc. Berlin, 1903. Breteau, p. Guide Pratique des Falsifications et Alterations des Substances ali- mentaires. Paris, 1907. BujARD, A., and Baier, E. Hilfsbuch fiir Nahrungsmittel Chemiker. Berlin, 1894. BuRCKER, E. Traite des Falsifications et Alterations des Substances alimentaires et des Boissons. Paris, 1892. Clark, E., and Woodman, A. G. The Estimation of Minute Amounts of Arsenic. U. S. Dept. of Agric, Bur. of Chem., Circ. 99. Ephraim, J. Originalarbeiten liber Analyse der Nahrungsmittel. Leipzig, 1894, GiRARD, C. Analyse der Matieres alimentaires et Recherche des leurs Falsifica- tions. Paris, 1904. Hanausek, T. F. Die Nahrungs- und Genussmittel aus dem Pflanzenreiche. 1884. Hassall, a. H. Food, its Adulterations and the Methods for their Detection. London, 1874. KONIG, J. Chemische Zusammensetzung der menschlichen Nahrungs- und Genuss- mittel. Berlin, 1903. Die Untersuchung landwirtschaftlich und gewerblich wichtiger Stoffe. Berlin, 1906. Leach, A. E. Food: Methods of Inspection and Analysis. Article in Reference Handbook of the Medical Sciences, Vol. 3, pages 180-183. Leffmann, H., and Beam, W. Select Methods of Food Analysis. Philadelphia, 1905. Mansfeld, M. Die Untersuchung der Nahrungs- und Genussmittel. Leipzig, 1905. Neufeld, C. a. Der Nahrungsmittelchemiker als Sachverstandiger. Berlin, 1907. PoLiN et Labit. Examen des Aliments suspects. Paris, 1892. Richards, E. H., and Woodman, A. G. Air, Water, and Food. New York, 190x5. ROTTGER, H. Kurzes Lehrbuch der Nahrungsmittel Chemie. Leipzig, 1903. Rupp, G. Die Untersuchung von Nahrungsmitteln, Genussmitteln und Gebrauchs- gegenstanden. 1900. 8o FOOD INSPECTION AND ANALYSIS. Thoms, H., und GiLG, E. Einfiihrung in die praktische Nahrungsmittel-Chemie. Leipzig, iSgg. ViLLiERS, A., et Collin, E. Traite des Alterations et Falsifications des Substances alimentaires. Paris, iqoo. WiESNER, J. Die Rohstoffe des Pflanzenreiclies. Leipzig, 1900. Wiley, H. W. Principles and Practice of Agricultural Analysis. Vol. III. Agricul- tural Products. Chem. Pub. Co., Easton, Pa., 1906. The Analyst. London, 1877 et seq. Revue International des Falsifications. Amsterdam, 1888 et seq. Vierteljahresschrift der Chemie der Nahrungs- und Genussmittels. Berlin, 1884 et seq. (Discontinued 1897.) Zeitschrift fiir Untersuchung der Nahrungs- und Genussmittel. 1898 et seq. Vereinbarungen zur Untersuchung und Beurtheilung von Nahrungs- und Genussmit- teln. Berlin, 1897. Also the following bulletins of the Bureau of Chemistry, U. S. Deptartment of Agriculture : Bulletin 13, Parts i-io. Food and Food Adulterants. 1887-1902. Bulletin 46. Methods of Analysis adopted by the A. O. A. C. 1899. Bulletin 65. Provisional INIethods for the Analysis of Foods, adopted by the A. O. A. C Nov. 14-16, 1901. 1902. Bulletin 107, rev. Official and Provisional Methods of Analysis. A. O. A. C. 1908. CHAPTER V. THE MICROSCOPE IN FOOD ANALYSIS. Microscopical vs. Chemical Analysis. — A very important means of identification of adulterants in many classes of food products is furnished by the microscope, which in many cases affords more actual information as to the purity of food than can be obtained by a chemical analysis. This is especially true of coffee, cocoa, and the spices, wherein the micro- scope serves to reveal not only the nature of the adulterants, but also not infrequently the approximate am.ount of foreign matter present. In the case of the cereal and leguminous products so commonly employed as adulterants, a microscopical examination is of paramount importance. The chemical constants of many of the adulterants of coffee and the spices do not always differ sufficiently from those of the pure foods in which they appear to be distinguished therefrom with accuracy and confidence by a chemical analysis alone. On the other hand, one who is familiar with the appearance under the microscope of the pure foods and of the starches and various ground substances used as adulterants, can, with certainty, identify ver}' minute quantities of these materials, when present, witli the same ease that one can recognize megascopically the most fam.iliar objects about him. A chemical test may, for example, indicate the presence of starch, but it cannot reveal the particular kind of starch. The microscope will at once show whether the starch present is wheat or corn or potato or arrowroot, since these starches differ almost as much in microscopical appearance as do the physical characteristics of the grains or tubers from which they are obtained. Again, by a chemical analysis an abnormal amount of crude fiber may show the presence of a woody adulterant, but only the microscope will enable one to decide whether the impurity consists of sawdust or ground cocoanut shells. Not only in such in- stances as these is the microscopical examination of greater importance 82 FOOD INSPECTION AND ANALYSIS. than a chemical analysis in establishing the purity of the food, but it is at the same time a much quicker guide. The Technique of Food Microscopy. — The recognition of adulterants by the microscope requires some experience but no more than may be acquired by a chemist who will give the subject serious attention. In the examination of cocoa, coffee, tea, and the spices for adulteration, a care- ful study of the powdered substance in temporary water mounting will in most cases prove sufhcient to familiarize the food analyst with their characteristics under the microscope, and it is not absolutely necessary for him to familiarize himself with the details of section cutting, dissect- ing, or permanent mounting unless he so desires. The treatment in detail of these latter branches of vegetable histology is beyond the scope of the present work. For full information along these lines the reader is referred especially to such works as those of Behrens*, Zimmerman, f and ChamberlainJ together with the list of references on page 98. Standards for Comparison. — For standards the analyst should provide himself with as complete a set as possible of the various materials to be examined, taking care that their absolute purity is established. Where- ever possible, he should grind the sample himself from carefully selected whole goods. These, together with samples of the starches and other adulterants, all of known purity, should be contained in small vials care- fully stoppered and plainly labeled, arranged alphabetically or in some equally convenient manner in the desk or table on which the microscope is commonly used. The adulterants included in this set of standards should be not only those which experience has shown most liable to be employed, but any which, by reason of their character, might in the analyst's opinion be used under certain conditions. APPARATUS. The Microscope-stand. — An expensive or complicated stand is un- necessary. The prime requisites for good work in a microscope-stand are firmness or rigidity, and accuracy in centering. An inexpensive stand possessing these features can be used for the best work, providing the optical parts are satisfactory. It is well, if economy must be practiced, to purchase a simple stand provided with the society screw, and let the larger portion of the allowance go for a high grade of lenses, since many of the attach- ments inherent in a high-priced stand, though often of convenience, may well be dispensed with. * Guide to the Microscope in Botany. f Botanical Microtechnique. % Methods in Plant Histology. THE MICROSCOPE IN FOOD ANALYSIS. 83 A stand of the so-called continental type (having the horseshoe base) is preferable. A square stage is rather more convenient than the circular form, and the jointed pillar possesses advantages over the rigid variety in ease of manipulation that are certainly worth considering. The smooth working of both the coarse and fine adjustments should not be lost sight of. If the microscope is to be used exclusively for food work, a substage condenser is unnecessary, hence the construction of the Fig. 31. — Continental Type of Microscope. substage may be very simple, unless bacteriological work is to be done as well. A nose-piece, while not indispensable, is a great convenience for the quick transfer of objectives. A double nose-piece carrying two objectives is ample for routine food work. The Optical Parts are by far the most important, and should be of superior quality, though not necessarily of the most expensive makers. The food analyst should have at least two objectives, one for high- and one for low-power work, and preferably two oculars. For the routine examination of powdered food substances the writer prefers a |-inch objective, used with a medium ocular, the combination giving a magnification of from 240 to 330 diameters, according to the ocular employed. For a low-power objective the |-inch is a conven- 84 FOOD INSPECTION yIND ANALYSIS. ient size. It is useful as a finder preliminary to examination with the higher power, and, in connection with a low-power eyepiece, is well adapted for the examination of butter and lard, and for use with the polariscope. An eyepiece micrometer mounted in an one inch ocular is indispen- sable for measuring starch grains and other elements. It is calibrated by means of a stage micrometer. The Micro-polariscope.— This accessory is useful in the identification of starches and other ingredients, and for ascertaining whether or not fats have been crystahized. The polarizer is held below the stage, while the analyzer is applied above the objective, either in the tube or above the ocular. »llite S!'lT|!iii'i:|i|iini!iii !i!l!^ Fig. 32. — Polarizer and Analyzer for the Microscope. A common form of construction is one in which the substage is adapted to carry interchangeably the diaphragm tube and the polarizer. If the polariscope is much used, it becomes desirable to provide means for quickly changing the polarizer and diaphragm tube below the stage, and for moving the analyzer in and out of place above the objective. Winton* has devised a microscope-stand with this in view, especially adapted to the needs of the food analyst. If the polariscope is to be used often, it is convenient to have within •"asy access two stands, one with the polariscope mounted in place in i-onnection with low-power glasses ready for use, and the other stand )rovided with the ordinary high- and low-power objectives only. Microscope Accessories include of necessity a large number of slides Ind cover glasses. The latter should be No. 2 thickness, | inch, either round or square. One or more dissecting-needles in holders and a small hand magni- fying-glass should also be provided. * Journal App. Microscopy, 2, p. 550. THE MICROSCOTE IN FOOD ANALYSIS. 85 Other useful accessories are a mechanical stage, a pair of fine tweezers, knives, scissors, and, if sections are to be cut, a plano-concave razor. MICROTECHNIQUE. Preparation of Vegetable Food Products for Microscopical Examina- tion. — The ground spices and cocoas of commerce are usually of the requisite fineness for direct examination without further treatment. Cojffee, chocolate, starches, and similar products should be ground in a mortar fine enough to pass through a sieve with from 60 to 80 meshes to the inch. A small portion of the powdered sample is taken up on the tip of a clean, dry knife-blade, and placed on the microscope-slide. By means of a medicine-dropper a drop of distilled water is applied, and the wetted Fig. 33. — Mechanical Stage for Microscope. powder is then rubbed out under the cover-glass between the thumb and finger to the proper fineness. The water-mounted slide thus prepared, while useful only for tem- porary purposes, has proved to be best adapted to the analyst's require- ments for routine microscopical examination of powdered food products for adulteration, partly because water is the best medium in most cases for showing up the structural characteristics of these substances and their adulterants, and partly because it serves best for the "rubbing out" process between thumb and finger under the cover-glass, whereby the sample is brought to the requisite degree of fineness. Experience will soon show how far this rubbing out should be carried for the best effects. Gentle pressure should be applied, care being taken not to break the cover-glass, especially if the sample contain anything of a gritty nature. The rubbing should be continued till the coarser par- 86 FOOD INSPECTION AND ANALYSIS. tides and overlying masses are separated and distributed uniformly, but if too long persisted in, the forms of the tissues, starch grains, and other characteristic portions will be partially destroyed and of too fragmentary a nature to be readily recognizable. Canada Balsam in Xylol is a useful mountant for the examination of starches with polarized light. In this medium, under ordinary illumina- tion, the starches are not plainly visible, since the refractive index of the two are nearly identical, but with crossed nicols the starch grains stand out clearly and distinctly in a dark background. If the material is not perfectly dry it should be soaked in absolute alcohol and then in chloroform or xylol until dehydrated. Glycerin. — A mixture of equal parts of glycerin and water is perhaps the best medium for permanent mounts, but considerable skill is required to finish the preparation with cement on the edge of the cover- glass. Glycerin jelly is more readily handled by the beginner since no cement is required. Glycerin Jelly * is prepared as follows : i part by weight of the finest French gelatin is soaked two hours in 6 parts of distilled water, after which 7 parts by weight of C. P. glycerin are added, and to each loo parts of the mixture add i part of concentrated carbohc acid. Heat the mixture while stirring till fiocculency disappears and filter through asbestos while warm, the asbestos being previously w^ashed and put into the funnel while wet. The jelly is sohd at ordinary temperatures, and must be warmed to melt. A small bit of this jelly is removed from the mass by a knife-blade and placed on the clean-slide, which is held over a gas flame till the jelly is melted. The powdered specimen being then shaken into the molten drop, the cover-glass is gently placed upon it (being brought down obliquely to avoid formation of air-bubbles) and pressed down in place. Microscopical Diagnosis.- — It is never safe to pass judgment on a spice or other food by the microscopical examination of a single portion. Several slides should be prepared with bits of the powder taken from different parts of the mass, before the character and extent of the adultera- tion can be safely determined. Care should be taken that the slide, the knife-blade, the water, and the medicine-dropper be perfectly clean and free from contamination with previous specimens. It should be borne in mind that at best a composite powdered sample * Botan. Centralbl., Bd. i, p. 25. THE MICROSCOPE IN FOOD AN /I LYSIS. 87 is but a mechanical mixture of various tissues, and that no two portions will show exactly the same composition. Characteristic Features of Vegetable Foods under the Microscope.— The structural features of a powdered spice, examined microscopically, will be found to differ considerably in appearance from those of a thin, carefully mounted section of the same spice. Instead of the beautiful arrangement of cells and cell contents with the perfect order of various parts as seen in the mounted section, one finds in the powdered sample under the microscope what often appears to be a most confusing mass of fragments of various tissues. For this reason the most striking charac- teristics seem to vary with different observers, and it is a well-known fact that microscopists differ widely as to conceptions of size, shape, and ordinary appearance, even in the case of certain of the well-known starch grains. It is on this account that, irrespective of the description of others, the analyst should familiarize himself with the microscopical appearance of the foods with w^hich he is dealing, as well as of their adulterants, form- ing his own standards as to what constitute the recognizable features, from specimens prepared by himself. In the large variety of ground berries, buds, tubers, barks, etc., from which the spices and condiments are prepared, , as well as in the grains, legumes, shells, fruit stones, and other materials forming the most familiar adulterants, the kinds of plant tissues and cell contents which, under the microscope, serve as distinguishing marks or guides for identification are comparatively few in number. The most common of these varieties of cell tissue and of cell contents to be met with by the food microscopist in his work are brietly the follow- ing: Parenchyma. — This is most abundant and widely distributed, forming as it does the thin-walled, cellular tissue of nearly all vegetable food sub- stances. The walls of parenchyma cells are, as a rule, colorless and transparent. The forms of the cells are varied and are often sufficiently characteristic in themselves to identify the substance under examination. Sclerenchyma, or stone cells, are the thick-walled woody cells forming the hard part of nut shells, fruit stones, and seed coverings, occurring also in some fruits and barks. These cells are more often colored and of various shapes but almost always irregular, sometimes elongated, as in cocoanut shells and olive stones, occasionally nearly rectangular, as in pepper shells, and sometimes polygonal or nearly circular. In appearance the sclerenchyma cell commonly has a more or less 8S FOOD INSPECTION ^ND ANALYSIS. deep, central or axial cavity, from which small fissures extend through the thick walls. See Fig. 35. Variously shaped sclerenchyma cells are found in allspice, cassia, mm i>!S&tiyn« Fig. 34. — Typical Forms of Various Cell Tissues. Longitudinal section through a clove, showing: Pp, two forms of parenchyma; B, bast fibers; g, vascular and sieve tissue; KK', cells with calcium oxalate crj-stals. (After \'ogl.) pepper, clove stems, nut shells, etc. Stone cells are optically active to polarized light, and between crossed nicols are very conspicuous by their bright appearance. Fig. 35. — Sclerenchyma, or Stone-cell Tissue. A cross-section through the stone-cell layer of the fruit shell of black pepper. (After Vogl.) Fibro-vascular Bundles are composed of three parts: the bast fibers, or mechanical elements, the phloem, and the xylem. THE MICROSCOPE IN FOOD ANALYSIS. 8? Bast Fibers are elongated, pointed sclerenchyma cells, of which flax fibers are examples. Sieve Tubes, the characteristic elements of the phloem, are thin- walled tubes with perforated partitions known as sieve plates. Vessels or Ducts occur in the xylem. They are designated as spiral, annular, reticulated, or pitted, according to the nature of the walls. Corky Tissue, or Suberin, constitutes the thin-walled, spongy cells forming the protective, outer dead layers of the bark. This is found in cassia, and in the barks used as adulterants. Suberin is tested for by potassium hydroxide (p. 93). jF^ Starch wherever it occurs furnishes the most charac- (fe^ teristic feature of the cell contents, and, as a rule, will at once indicate under the microscope, by the shape and grouping of its granules, the particular substance of which it forms a part. It is very abundantly distributed through- out the vegetable kingdom and occurs in a wide variety of forms. It is particularly conspicuous when viewed by polarized light. Between crossed nicols such starches as corn, potato, and arrowroot show out brightly from a dark background with dark crosses, the bars of which ^^^' 36.— Reticula- , , •, r ^ 1 TTTi 1 • ted Ducts of Chic- intersect at the hilum of each granule. When a selemte ory. (After Vogl.) plate is introduced above the polarizer, a beautiful play of colors is seen with various starches, a phenomenon which Blyth appHes as a means of identification and classification, but which more modern micro- scopists regard as of minor importance to distinguishing the various starches morphologically. Starch is found naturally in the cereals, legumes, and many vegetables, in cassia, allspice, nutmeg, pepper, ginger, cocoa, and turmeric. The cereal and leginninous starches from their inertness and cheapness constitute the most common adulterants of the spices and of powdered foods in general. Starch grains are found in the cells of the parenchyma and in other cellular tissues. Iodine is the special reagent (p. 91). Gums and Resins occur in characteristic forms among the cell contents of some of the spices. As an example, the portwine-colored lumps of gum in allspice furnish one of the most ready means of recognizing that spice microscopically. Resin is tested for microchemically with alkanna tincture (p. 92). 90 FOOD INSPECTION AND ANALYSIS. Aleurone, or Protein Grains, occur in some of the spices, but are not especially characteristic. They somewhat resemble small starch grains. Most varieties of protein grains are soluble in water, but some are insoluble. The soluble varieties, which are not apparent in water- mounted specimens,, must be examined in absolute alcohol, glycerin, or oil. In leguminous seeds aleurone- occurs closely intermingled with starch in the same cells, while in the cereals it occupies the whole cell. Protein grains are tested for under the microscope by iodine in potas- sium iodide, which turns them brown or yellowish brown, and by Millon's reagent, which colors them brick red. Plant Crystals are not uncommon in the class of substances which the food analyst examines. Among the common forms are the piperin crystals found in pepper. Calcium oxalate occurs in many vegetable products as prismatic crystals, crystal aggregates, or needle-shaped crystals (raphides). Crystals of calcium carbonate are sometimes met with also, as, for example, in hops. Calcium oxalate crystals are insoluble in acetic acid, while being readily soluble in dilute hydrochloric. Calcium carbonate crystals are soluble with effervescence in both acids. The acid reagents are directly appHed to the sample in water-mount under the cover-glass, and the reaction observed through the microscope. Fat Globules are of common occurrence in many foods and appear of various sizes, sometimes large and conspicuous, and again almost lost sight of because of their minuteness. They are sometimes colorless, as in mace, and sometimes deeply tinted, as in cayenne. Alkanna tincture is used as a reagent for fat (p. 92). Other Cell Contents of less importance, but which may be identified by the microscope with reagents, are tannic acid (tested for by chloriodide of zinc and ferric acetate (pp. 91 and 92), and various essential oils, for the detection of which alkanna tincture is employed. REAGENTS IN FOOD MICROSCOPY. Unless a more extended microscopical investigation of vegetable food substances is contemplated than is involved in the mere identification of aduherants, the analyst will have little need for reagents,* but will depend almost entirely on the form and appearance of the various tissues or tissue fragments, as well as on the abundance, shape, and distribution of such distinctive cell contents as the starches, fat globules, or cr>'stals. * One reagent that is really necessary on the microscope-table, and will very often be required is iodine in potassium iodide. THE MICROSCOPE IN FOOD ANALYSIS. 9 1 Analytical reagents are applied to the water- mounted sample by means of a glass rod or pipette, with which a drop of the reagent is deposited on the sample upon the slide, having previously removed the cover, which is afterwards replaced. Or, without removing the cover-glass, a drop of the reagent is placed in contact with one side of it on the slide. Along the opposite side of the cover is then placed a piece of filter- paper. The latter withdraws by capillary attraction a portion of the water from under the cover-glass, and this is replaced by the reagent, which thus intermingles with the particles of the substance. Following is a brief list of the commoner microchemical reagents, together with their method of preparation and chief uses. For fuller details in this branch of the subject the reader is referred to Poulsen's Botanical Microchcmistry, translated by Trelease, and Zimmerman's Botanical Microtechnique. A. Analytical Reagents. — Iodine in Potassium Iodide. — Two grams of crystallized potassium iodide are first dissolved in 100 cc. of distilled water and the solution is saturated with iodine. This reagent is indispensable for the identification of starch, especially when the latter is present in minute quantities. Starch granules when moistened with water are turned blue by iodine, the reaction being exceed- ingly delicate under the microscope, even when the starch granules are very minute and insignificant without the reagent. Iodine in connection with sulphuric acid is also useful in distinguishing pure cellulose from its various modifications, such as lignin and suberin. For this purpose the water-mounted sample is first permeated with the iodine reagent, after which concentrated sulphuric acid is applied, with the result that all pure cellulose is turned a deep-blue color, while the modified forms of cellulose are colored yellow or brown. The cellulose is first converted by the sulphuric acid into a carbohydrate isomeric with starch, known as amyloid. Protein grains are colored brown or yellow brown by the action of iodine. Chloriodide 0} Zinc. — Pure zinc is dissolved in concentrated hydro- chloric acid to saturation, and an excess of zinc added. The solution is then evaporated to about the consistency of concentrated sulphuric acid, after which it is first saturated with potassium iodide, and finally with iodine. This reagent may be used instead of sulphuric acid and iodine for the 92 FOOD INSPECTION AND ANALYSIS. detection of cellulose, since the zinc chloride converts the cellulose into amyloid, which the reagent colors blue, Chloriodide of zinc is useful for detecting tannic acid in cell contents. For this purpose the above reagent is much diluted by the addition of a 20% solution of potassium iodide. In this diluted form, when applied to the sample, a reddish or violet coloration is imparted to cell contents having tannin. Phenol-hydrochloric Acid is prepared by saturating concentrated hydrochloric acid with the purest crystallized carbolic acid. Wood fiber, or lignin, when treated with a drop of this reagent under the cover-glass, and exposed for half a minute to the direct sunlight, will be colored an intense green, which quickly fades. Indol. — Several crystals of indol are freshly dissolved in warm water. Lignified cell walls assume 9, deep-red color, when the specimen to be examined is treated first with a drop of the indol reagent, and afterwards washed with dilute sulphuric acid, i : 4. Millon's Reagent. — This is prepared by dissolving metallic mercury in its weight of concentrated nitric acid, and diluting with an equal volume of water. This reagent, which should be freshly prepared, is of use in testing for protein compounds, which turn brick red when treated with it, especially on gently warming the slide. Tincture 0} Alkanna. — A 70 or 80% alcoholic extract of alkanna root, when kept in contact with resins, fixed oils, fats, or essential oils for a short time, stains these cell contents a Hvely red. The staining is hastened by the aid of heat. Essential oils and resins are soluble in strong alcohol, while fixed oils and fats are insoluble, hence the distinction between these classes of cell contents may be made by the application of alcohol to the alkanna-stained specimen. Ferric Chloride, Ferric Acetate, or Ferric Sulphate, used in dilute aqueous solution, are all applicable as reagents for tannic acid, which, when present in appreciable amount, will be colored green or blue by either of these reagents. B. Clarifying Reagents. — Many of the harder cellular tissues are too opaque for careful examination, and maybe rendered transparent by clarify- ing or bleaching. A portion of the powdered sample is either treated with a drop of the reagent under the cover-glass or is allowed to soak for hours or even days in the reagent, using a drop of the same reagent as a medium for examination on the object-glass, instead of water. The clarifying reagents most commonly used arc the following: THE MICROSCOPE IN FOOD yINALYSIS. 93 Chloral Hydrate. — A 60% solution. Ammonia. — Concentrated, or 28% ammonia is commonly used. Potassimn Hydroxide, used in various degrees of concentration, often in dilute solution, say 5-7. This reagent, added to a water mount, causes swelling of the cell wall, and dissolves intercellular substances and protein. It bleaches most of the coloring matters, destroys the starch; and forms soluble soaps with the fats. Potassium hydroxide is also used in testing for suberin, which is extracted from corky tissue on boiling with the reagent, and appears as yellow drops. Schulize's Macerating Reagent (concentrated nitric acid and chlorate of potassium) is best used by placing the powder or bit of tissue to be treated in a test-tube with an equal volume of potassium chlorate crystals, adding about 2 cc. of concentrated nitric acid, and warming the tube till bubbles are evolved freely, or until the necessary separation of cells is effected. The sample is then removed and washed with water. By this treatment, bast and wood fibers as well as stone cells are readily separated from other tissues. Cuprammonia (Schweitzer's Reagent). — This is prepared by adding slowly a solution of copper sulphate to an aqueous solution of sodium hydroxide, forming a precipitate of cupric hydroxide, which is separated by filtration, washed, and dissolved in concentrated ammonia. It should be freshly prepared, and is never fit for use unless it is capable of immediately dissolving cotton. Indeed its chief use is as a test for cellulose, which it readil}' dissolves. In observing this reaction under the microscope, the powdered specimen under the cover-glass should be only slightly damp before a drop of the fresh reagent is applied. The cell w^alls are seen to swell up and gradually become more and more indistinct, till they finally disappear. Cuprammonia is also used as a test for pectose, which occurs in many cell walls, often intermixed with cellulose. When treated with this reagent, cellular tissue containing pectose is acted upon in such a manner that a delicate framework of cupric pectate is sometimes left behind, after the dissolution of the cellulose with which it is mingled.* PHOTOMICROGRAPHY. The photomicrograph serves as a simple means of keeping perma- nent records of unusual forms of adulteration encountered in the course of routine examination. Besides this, the photomicrograph has at times proved its usefulness as a means of evidence in court, showing as it does with faithfulness the presence of a contested adulterant. It is true * Poulsen, Botanical Micro-chemistry, p. 15. 94 FOOD INSPECTION ^ND ^N^ LYSIS. that from an artistic standpoint the photomicrograph of a powdered sample is often disappointing, due to the fact that ordinarily much of the field is out of focus, unless a very simple homogeneous subject is photo- graphed, as, for instance, starch. As compared with the carefully prepared drawing of a section, which is usually idealized, the photomicrograph is in a sense the more truthful re])rescntation. SUMMARY OF MICROCHEMICAL REACTIONS FOR IDENTIFYING CELLULAR TISSUE AND CELL CONTENTS. BASED ON BEHRENS'.* Iodine in Potassium Iodide. Chlor- iodide of Zinc. Iodine and Sul- phuric Acid. Cupram- monia. Potassium Hydroxide. Concen- trated Sulphuric Acid. Schultze' s Mixture. Cellulose, cell substance. Lignin, wood substance. Middle lamella, inter- Yellow to brownish Yellow Yellow Yellow or brownish Blue Brown yellow Violet Yellow Yellow Yellow or brown Blue Yellow to brownish Yellow Brown Dissolves Insoluble Insoluble Insoluble Swells up Dissolves Dissolves Dissolves Dissolves Dissolves easily Suberin, cork substance. Starch Insoluble in cold. By boiling it comes out in drops Dissolves Dissolves Insoluble easily Gives eerie acid reac- tiont Fat Saponifies Reddish to violet Calcium oxalate crystals Phenol- hydro- chloric Acid. Indol. Ferric Acetate or Sul- phate. Alkanna Tincture. Hydro- chloric Acid. Acetic Acid. Millon's Reagent. Cellulose, cell substance. Lignin, wood substance. Middle lamella, inter- Uncolored Green Green Uncolored Uncolored Cherry red Cherry red Uncolored Brick red Bright red Bright red Bright red Fat Blue or green Calcium oxalate crystals Soluble without ef- fervescence Soluble with effer- vescence Insoluble Soluble with effer- vescence * Microscopical Investigation of Vegetable Substances, page 356 t When treated with the reagent, suberin forms masses of eerie ; chloroform acid, soluble in ether, alcohol, or While the analyst examines microscopically the ordinary powdered spice, for example, he constantly moves with his hand the fine adjustment- screw, bringing into focus different parts of the field successively. This THE MICROSCOPE IN FOOD ANALYSIS. 9$ he does unconsciously, so that he does not reaHze how far from fiat the field actually is till he undertakes to photograph it, when, as a rule, only a small portion is in good focus. It is therefore impossible in one photo- graph to show successfully many varied forms of tissue or cell contents in the powder, but separate photographs should be made as far as possible with only a Httle in each. Thus, for example, with a composite subject like powdered cassia bark, it would be very difficult to show starch, stone cells, and bast fibers in one field, all in equally good focus, and, for the best results only, one, or at most two, such varied groups of elements should be shown in one picture. Appurtenances and Methods of Procedure. — The temporary' method of water-mounting employed by the analyst in routine examination pre- sents many difficulties from a photographic point of view. The vibrating motion of the particles is very annoying, and some skill is required in using just the right amount of water, in avoiding air-bubbles, in waiting the requisite amount of time before exposing the plate for the vibratory motion to cease, and, on the other hand, avoiding too long delay, which would result in the evaporation of the water, and the consequent breaking up of the field. In the writer's experience, however, in spite of these difficulties, the water-mounting gives decidedly the clearest results, and, with patience on the part of the operator, it is in many ways the most desirable method of mounting for photographic purposes. It is in fact the method employed in making most of the photomicrographs of powdered specimens that appear in the plates at the end of this volume, though a few were mounted in ■glycerin jelly, and the starches for the polarized-light pictures in Canada balsam. The sections of tissues shown in the plates were mounted some in glycerin and others in glycerin jelly. Experience has shown that two degrees of magnification well cal- culated to bring out the chief characteristics of the spices and their adul- terants in a photomicrograph are 125 and 250 diameters. The starches, which are the most common of any one class of adulterants, vary very widely in the size of their granules. With these the larger magnification of 250 has been found satisfactory, while the general appearance of the composite ground-spice itself under the microscope, as well as that of such adulterants as ground bark, sawdust, chicor}', pea hulls, and the like, is best shown with the lower power of 125.* * The degrees of magnification adopted in the originals of most of the photomicrographs illustrated in the accompanying plates are accordingly 125 and 250, but in the process of lithographing, the photographs were slightly reduced, so that the actual scales in the repro- duction are no and 220 respectively. 96 FOOD INSPECTION AND ANALYSIS. The object, mounted in the manner above described, is best examined when held in a mechanical stage, furnished with micrometer adjust- ments, in such a manner that a typical field may be selected and held in place long enough to photograph. The Camera. — This need not of necessity be complicated, but may consist simply of a horizontal wooden base on which the microscope \ Fig zici- — A. Convenient Photomicrographic Camera. rests, and an upright board firmly secured to the base, carrying a frame for an interchangeable ground glass and plate-holder, with a rubber gauze skirt hanging from the frame, adapted to be gathered and tied about the top of the microscope-tube. Means are further provided, as by a slotted guide and screw, for adjusting the frame at any desired height on the upright board.* A more convenient form of apparatus now employed by the writer is that shown in Figs. 370 and 376. * Such a contrivance as this was employed in making some of the accompanying photo- micrographs. THE MICROSCOPE IN FOOD AN /I LYSIS. 97 The base is a solid iron plate upon which the microscope rests (any microscope may be used with this camera), and above which the camera bellows is supported on two solid steel rods. The bellows is supported at either end on wooden frames. The ground glass is provided with a central transparent area, formed by cementing a cover-glass upon the ground glass, and permits the accurate focusing of the most delicate detail by means of a hand magnifying-glass. The vertical rods supporting the bellows are attached to metal arms, immovably fixed to a horizontal axis, thus permitting the camera to be tilted Fig syb. — Photomicrographic Camera in Horizontal Position to any angle from vertical to horizontal. It is fixed at the desired angle by means of heavy hand-clamps. In use the camera is placed in a vertical position and the microscope adjusted on the base so that its tube will coincide with the opening in the front of the camera. The connection between microscope and camera is made light-tight by m.eans of a double chamber, which permits consider- able vertical motion of the tube of the microscope without readjustment. A jointed telescoping rod is attached to the upper end of the camera to act as a support, giving perfect steadiness when in a horizontal position, and folding down parallel with the bellows so as to be out of the way when in any other position. Amplification. — The vertical rods are graduated in inches for deter- mining the amount of amplification, and to show when the ground glass is at right angles to the optical axis. The following simple rule for deter- mining the amount of amplification will give sufficiently accurate results. When photographing without the eyepiece, divide the distance of the ground glass from the stage of the microscope in inches, by the focal length in inches of the objective used. When photographing with the eye- piece, proceed as above and miultiply the result by the quotient obtained by dividing lo by the focus in inches of the eyepiece used. 93 FOOD INSPECTION y4ND ANALYSIS. Adjustment and Manipulation. — The microscope can be placed in any position desired, and the camera adjusted to it. The bellows can then be raised and the microscope used as though no camera were present. When an object is to be photographed, the bellows may be slid into posi- tion without in any way disturbing the arrangement of light or object, the final focusing on the ground glass being effected quickly by means of the fine adjustment-screw of the microscope. The exposure having been made, observation through the microscope may be continued with- out interruption by simply raising the bellows again. When a water-mounted specimen is to be photographed, the camera and microscope tube should be vertical instead of inclined as shown in the cut. The camera is best kept in a dark room where the exposures are to be made, the source of light being a i6- or 32-candle-power electric lamp, preferably provided with a ground-glass bulb. The light from this lamp is first carefully centered by moving the reflector of the microscope. In making pictures, for instance, of the magnification of 250 diameters, the objective, having an equivalent focus of ^ inch, may be used in combination with the one-inch ocular, with the ordinary tube length of microscope. For a lower power, such as 125 diameters, the same objec- tive is employed, but the eyepiece is left out, it being found necessary in this case to remove the upper tube of the microscope, which ordinarily carries the eyepiece, as otherwise the size of the field to be photographed would be restricted. In each case a diaphragm is used in the microscope stage, having an opening of about the same size as that of the front lens of the objective. By means of a stage micrometer scale, the proper posi- tion of the camera back is previously determined to give the required magnification. REFERENCES ON THE MICROSCOPE IN FOOD ANALYSIS. ALLTMA2snsr. Die Elementarorganismen und ihre Beziehungen zu den Zellen. Leipzig, 1890. Eehrens, J. W. Guide to the Microscope in Botany. Translated by Hervey. Boston, 1885. Bergen, J. Elements of Botany. Gross and Microscopic Structure. Vegetable Histology. Bessey, C. E. The Essentials of Botany. ■ Botany for High Schools and Colleges. New York, 1880. BoNSFiELD, E. C. Guide to Photomicrography. London. Chamberlain, C. J. Vegetable Tissues. Methods in Plant Histology. Chicago, 1905. THE MICROSCOPE IN FOOD ANALYSIS. 99 Clark, C. H. Practical Methods in Microscopy, 1900. Dammar, O. Illustrirtes Lexicon der Verfalschungen und Verunreinigungen der Nah- rungs- und Genussmittel. Leipzig, 1886. Detmer, W. Das pflanzenphysiologische Praktikum. Jena, 1885. DiETSCH, O. Die wichtigsten Nahrungsmittel und Getranke, deren Verunreinigungen und Verfalschungen. Zurich, 1884. Gage, S. H. The Microscope and Microscopical Methods. Ithaca, 1908. Greenish, H. G. The Microscopical Examination of Foods and Drugs. Philadel- phia, 191 1. Hanausek, T. F. The Microscopy of Technical Products. Translated by A. L. Winton and Kate G. Barber. New York, 1907. Haushofer, K. Mikroskopische Reaktionen. Braunschweig, 1885. Hegler. Histochemische Untersuchungen verholtzer Zellmembranen. Flora, 1S90, page 31. Hoffmeister, T. Die Rohfaser und einige Formen der Cellulose. Landwirtschaftl. Jahrbiicher, 1888, page 239. Koch, L. Mikrotechnische Mittheilungen. Pringsheim's Jahrbiicher, Bd. XXIV, page I, 1892. Kraemer, H. Botany and Pharmacognosy. Philadelphia, 1910. Kraus, G. Zur Kentniss der Chlorophyllfarbstoffe. Stuttgart, 1872. Lange, G. Zur Kentniss des Lignins. Zeits. fiir physiologische Chemie. Bd. XIV, page 15. Leach, A. E. Microscopical Examination of Foods for Adulteration. An. Rep. Mass. State Board of Health, 1900, p. 679. Lee, a. B. The Microtomist's Vade Mecum. 1893. Mace, E. Les Substances Alimentaire Etudies au Microscope. Paris, 1891. MoELLER, J. Mikroskopie der Nahrungs- und Genussmittel aus dem Pflanzenreiche. Berlin, 1905. Pharmacognostischer Atlas. Berlin, 1892. MoLiscH. Grundriss einer Histochemie der pflanzlichen Genussmittel. Jena, 1891. Neuhauss, R. Lehrbuch der Mikrophotographie. Braunschweig, 1890. PouLSEN, V. A. Botanical Microchemistry, translated by Trelease. Boston, 1886. Pringle, a. Practical Photomicrography. New York, 1890. ScHiMPER, A. F. W. Mikroskopischen Untersuchungen der Nahrungs- und Genuss- mittel. Jena, 1900. Strassburger, E. Manual of Vegetable Histology, translated by Hervey. 1887. Thomas and Dudley. A Laboratory Manual of Plant Histology. TscHiRCH, A., und Oesterle, O. Anatomischer Atlas der Pharmakognosie und Nahr- ungsmittelkunde. Leipzig, 1900. VoGL, A. E. Die wichtigsten vegetabilischen Nahrungs- und Genussmittel. Berlin, 1899. WiNSLOW, C. E. A. Elements of Applied Microscopy. New York, 1905. Winton, A. L. The Microscopy of Vegetable Foods. New York, 1906. WoRMLEY, T. G. The Microchemistry of Poisons. Philadelphia, 1885. ZiMMERM.\N, A. Botanical Microtechnique. New York, 1893. Die Morphologie und Physiologic der Pfianzenzelle. Breslau, 1887. Beitrage zur Morphologie und Physiologie der Pfianzenzelle. Tubingen, 1890. CHAPTER VI. THE REFRACTOMETER. i The refractive index ranks in importance with the specific gravity as a means of determining the identity and purity of various food products, as well as of estimating the percentage of valuable constituents. Various forms of refractometer are used in food analysis. The Abbe refractometer is of general application in determining the refractive index of fats, fatty oils, waxes, and essential oils, in esti- mating the solids in saccharine substances, and in other analytical opera- tions. It employs but a few drops of the material, and reads the refractive index directly, using ordinary white light. The immersion refractometer, an instrument of recent introduction, is suited for the examination of milk serum to detect added water therein, the detection and determination of methyl alcohol in ethyl alcohol, and the standardization of a wide variety of solutions. The instrument is immersed directly in the liquid to be examined, the degree of refraction being indicated on an arbitrary scale. The Pulfrich is used with the sodium light, and requires a larger amount of material than the Abbe, the liquid being held in a cylinder above the prism. The scale reading is in angular degrees, from which the index of refraction is calculated by a formula or from a table. The instrument is provided with a temperature-controlling apparatus. In the Amagat and Jean or oleo-refractometer, an outer and an inner cylinder are respectively filled with an oil of known value or purity, and with the oil to be examined. By the comparative displacement to the right or left of a beam of white light passing through both cylinders, the displacement being read in degrees on an arbitrary scale, the refraction of an oil may be measured. Two oils may thus be readily compared under the same conditions, one of known purity, for example, with a doubtful sample of the same kind. The butyro-refractometer and the Wollny milk fat refractometer (p. 139) are, as their names imply, instruments primarily intended for more restricted fields of work than the foregoing. They involve the same principle as the Abbe, but are simpler in construction and have arbitrary scales. Unless such widely varying substances as the waxes and the essential oils are to be studied, the Zeiss butyro-refractometer, though primarily THE REFRACTOMETER. lOI intended for the examination of butter and lard, answers most of the purposes of the Abbe instrument with the advantage of greater sim- plicity, being equally well adapted for examining all the common edible oils and fats, as well as other materials. THE ZEISS BUTYRO-REFRACTOMETER. This instrument (shown in Fig. 38) is so constructed that the degree of refraction of a beam of light, which passes obliquely through a thin Fig. 38. — The Zeiss Butyro-refractometer. film of the fat, is read on an arbitrary scale of sufificient extent to cover the widest limits of deviation possible for butter fat and oleomargarine under ordinary, temperatures. The graduation is in divisions from i to 100, covering a variation in refractive indices of from 1.4220 to 1.4895. .4 and B are the two hinged hollow portions of the prism casing of the instrument, so arranged that when closed together the melted fat is held in a film of sufficient thickness between the two opposed transparent prism surfaces, the beam of light, either diffused daylight or lamplight, being reflected through it by means of the mirror /. The transparent scale is within the telescope tube at the height indicated by G. I02 FOOD INSPECTION AND ANALYSIS. The refractometer is connected to any kind of heating arrangement, which admits of warm water being transmitted through the prism casing, in at D and out at E. A simple arrangement, which suffices for all ordinary cases, may expeditiously be improvised in the following manner: Fill a vessel of say 2 gallons capacity with water of 40° to 50° C. Into this vessel dip the free end of an india-rubber tube slipped over the nozzle D and let the vessel be placed at a height of about one-half or one jard above the refactometer. Then it will be seen that suction at a tube attached to E will cause the warm water to flow through the prism casing by the action of the siphon arrangement. By means of a pinch clip the velocity of the water may be regulated at will. The waste water may be allowed to flow into a second vessel and, provided its tem- perature does not fall below 30°, it may be used for replenishing the upper vessel. When working with solid fats, a temperature must be maintained by the heated water well above the melting-point of the fat. With liquid oils no heater is necessary, as determinations may be made at room temperature, but it is advisable in all cases to have a constant stream of water passing through the water jacket, which may be done by directly connecting it with the water faucet in the case of oils, since, without such precautions to insure even temperature, disturbing variations are liable to occur, due to the warming of the prisms by the manipulation of clean- ing, etc. Refractometer Heater. — ^A regular heater, shown in Fig. 39, is furnished by the manufacturers, capable of supplying a current of water of approx- imately constant temperature, and will be found of great convenience when the instrument is to be used constantly, especially with the solid fats. A supply reservoir A is secured to the wall and is connected by means of a rubber inlet tube G to the water faucet C. The reservoir is provided with a waste overflow pipe and with an outlet tube D, the flow through the latter being regulated by the cock H. The tube D leads to the spiral heater HS, which is heated by a Bunsen burner. From the heater the tube E conducts the warm water through the refractometer, from which it flows through the tube F, either directly into the sink, or into the inter- mediate vessel B. The temperature of the water is regulated by adjust- ing the cock H, and the height of the flame of the Bunsen burner. Manipulation of the Butyro-refractometer. — The prism casing is first opened by giving about half a turn to the right to the pin F, Fig. 38, until it meets with a stop. Then simply turn the half B of the prism THE REFR.^CTOMETER. 103 casing aside. Pillar H holds B in the position shown in Fig. 38. The prism and metallic surfaces must now be cleaned with the greatest care, the best means for this purpose being soft linen, moistened with a little alcohol or benzine. If the sample to be examined is a solid fat, maintain the temperature above the melting- pointy and apply by a glass rod a drop or two of the clear melted fat (filtered if turbid) to the surface of the prism contained In the casing B. For this purpose the apparatus should be raised with. ffl] (S\ Fig. 39.— The Zeiss Heating Apparatus for all Forms of Refractometer. cut in connection with the Pulfrich refractometer. Shown in the the left hand so as to place the prism surface in a horizontal position. A liquid oil is directly applied in the same manner without preliminary precautions as to heating. Now press B against A, and place F by turning it in the opposite direction, in its original position; thereby B is prevented from falling back,, and both prism surfaces are kept in close contact. Place the instrument again upon its sole plate. While looking into the telescope, give the mirror / such a position as to render the critical line, which separates the bright left part of the field from the dark right part, distinctly visible. It may also be necessary to move or turn the instrument about a little. First it will be necessary to ascertain whether the space between the prism surfaces be uniformly filled with oil or fat, failing which the critical line will not be distinct. For this purpose examine the rectangular image of the prism surface formed about i cm. above the ocular with a hand magnifier or with the IC4 FOOD INSPECTION AND AN /I LYSIS. naked eye, placing the latter at its proper distance from the ocular. Finally adjust the movable front part of the ocular so that the scale becomes clearly visible. By allowing a current of w^ater of constant temperature to flow through the apparatus some time previous to the taking of the reading, the at first somewhat hazy critical line approaches in a short time, generally after a minute, a fixed position, and quickly attains its greatest distinctness. When this point has been reached, note the appearance of the critical line (i.e., whether colorless or colored, and in the latter ease of what color); also note the position of the critical line on the centesimal scale, which admits of the tenth divisions being conveniently estimated; at the same time read the position of the thermometer. Testing the Adjustment 0} the Ocular Scale. — It is imperative that the adjustment of the instrument be tested periodically, and in particular when it is being used for the first time. This may be done by means of the standard fluid supplied with the instrument, the critical line of which is approximately colorless, and must occupy the following positions in the scale. Temper- Scale Temper- Scale Temper- Scale Temper- Scale at\ire. Division. ature. Division. ature. Division. ature. Division. 30= 68.1 25° 71.2 20° 74.3 15° 77-3 29= 68.7 24° 71.8 19° 74-9 14° 77-9 28° 69-3 230 72.4 18° 7,=^'- 5 13° 78.6 27° 70.0 22° 73-0 17° 76.1 12° 79-2 26° 70.6 21° 73-6 16° 76.7 11° 79-8 25 = 71.2 20° 74-3 15° 77-3 10° 80.4 The fractional parts of a degree can accordingly easily be brought into calculation (0.1=0.06 scale div.). Deviations of i to 2 decimals of the scale divisions are of no consequence, and are in most cases due to inexact determinations of temperature. Should, however, careful tests result in the discovery of greater deviations, readjustment of the scale will be necessary, which may be effected by means of a watch-key supplied with the instrument, in accordance with the values given in the above table. The watch-key is inserted at G in Fig. 38, and by its means the position of the objective, and therefore that of the critical line with respect to the scale may be altered. Transformation of Scale Divisions into Indices of Refraction. — The following table, adapted from that of Pulfrich, enables one to convert scale readings on the butyro-refractometer into indices of refraction, w^, and vice versa: THE REFRACTOMETER. loS EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC- TOMETER READINGS. Refrac- tive Fourth Decimal of « D. Index. »n. 1 2 3 4 5 6 7 8 9 SC.\LE READINGS 1.422 0.0 0.1 0.2 0.4 0-5 0.6 0.7 0.9 I.O I.I 1.42.^ 1.2 1.4 i-S 1.6 1-7 1-9 2.0 2.1 2.2 2-4 1.424 2-5 2.6 2-7 2.8 3-0 3-1 3-2 2-2 3-5 3-6 1.425 3-7 3-8 4.0 4-1 4-2 4-3 4-5 4-6 4-7 4-8 1.426 5-0 5-1 5-2 5-4 5-5 5-6 5-7 5-9 6.0 6.1 1.427 6.2 6.4 6.5 6.6 6.8 6.9 7-0 7-1 7-2 7-4 1.428 7-5 7-6 7-7 7-9 8.0 8.1 8.2 8.4 8-5 8.6 1.429 8.7 8.9 9.0 9.1 9-2 9-4 9-5 9.6 9.8 9-9 1.430 10. 10. 1 10.3 10.4 10.5 10.6 10.7 10.9 II. II. I 1-431 11-3 II. 4 II-5 II. 6 II. 8 II. 9 12.0 12.2 12.3 12.4 1.432 12.5 12.7 12. S 12.9 13.0 13-2 13-3 13-5 13.6 13-7 1-433 13.8 14.0 14. 1 14.2 14.4 14-5 14.6 14.7 14.9 15.0 1-434 15-1 15-3 15-4 15-5 15.6 15.8 15-9 16.0 16.2 16.3 1-435 16.4 16.6 16.7 16.8 17.0 17-1 17.2 17-4 17-5 17.6 1.436 17.8 17.9 18.0 18.2 18.3 18.4 18.5 18.7 18.8 18.9 1-437 19-1 19.2 19-3 19-5 19.6 19.7 19.8 20.0 20.1 20.3 1.438 20.4 20.5 20.6 20.8 20.9 21. 1 21.2 21.3 21.4 21.6 1-439 21.7 21.8 22.0 22.1 22.2 22.4 22.5 22.6 22.7 22.9 1.440 23.0 23.2 23-3 23-4 23-5 23.7 23.8 23-9 24.1 24.2 1. 441 24-3 24-5 24.6 24.7 24.8 25.0 25.1 25.2 25-4 25 -5 1.442 25.6 25.8 25-9 26.1 26.2 26.3 26.5 26.6 26.7 26.9 1-443 27.0 27.1 27-3 27-4 27-S 27-7 27.8 27-9 28.1 28.2 1.444 28.3 28.5 28.6 28.7 28.9 29.0 29.2 29-3 29-4 29.6 1-445 29-7 29.9 30.0 30.1 2,0-2, 30-4 30.6 30-7 30.8 30-9 1.446 31-1 31.2 31-4 31-5 31.6 31-8 31-9 32-1 32-2 32.3 1-447 32-5 32.6 32.8 32-9 Z3-° 33-2 2,3-2, 33-5 33-6 33-7 1.448 33-9 34-0 34-2 34-3 34-4 34-6 34-7 34-9 35-0 35-1 1.449 35-3 35-4 35-6 35-7 35-8 36.0 36-1 36.3 36.4 36- s 1.450 36.7 36.8 37-0 37-1 37-2 37-4 37-5 37-7 37-8 37-9 I-451 38.1 38.2 38-3 38.5 38-6 38.7 38-9 39-0 39-2 39-3 1-452 39-5 39-6 39-7 39-9 40.0 40. 1 40.3 40.4 40.6 40.7 1-453 40.9 41.0 41. 1 41-3 41.4 41-5 41.7 41.8 42.0 42.1 1-454 42.3 42.4 42.5 42.7 42.8 43-0 43-1 43-3 43-4 43-6 1-455 43-7 43-9 44.0 44-2 44-3 44-4 44-6 44-7 44-9 45 -o 1-456 45-2 45-3 45-5 45-6 45-7 45-9 46.0 46.2 46.3 46.4 1-457 46.6 46.7 46.9 47.0 47-2 47-3 47-5 47-6 47-7 47-9 1.458 48.0 48.2 48-3 48.5 48.6 48.8 48.9 49.1 49-2 49 4 1-459 49-5 49-7 49.8 50.0 50.1 50.2 50-4 50-S 50-7 50.8 r.460 51.0 51 -I S^^-i 51-4 51.6 51-7 51-9 52.0 52.2 52-3 1. 461 52-5 52-7 52.8 53-0 53-1 53-3 53-4 53-6 53-7 53-9 1.462 54-0 54-2 54-3 54-5 54-6 54-8 55 -o 55-1 55-3 55-4 1.463 55-6 55-7 55-9 56.0 56.2 56.3 56-5 56-6 56.8 56-9 1.464 57-1 57-3 57-4 57-6 57-7 57-9 58.0 58-2 58-3 58-5 1.465 c;8.6 58.8 58.9 59-1 59-2 59-4 59-5 59-7 59-8 60.0 1.466 60.2 60.3 60.5 60.6 60.8 60.9 61. 1 61.2 61.4 61.5 1.467 61.7 61.8 62.0 62.2 62.3 62.5 62.6 62.8 62.9 63.1 1.468 63.2 63-4 63-5 63-7 63.8 64.0 64.2 64-3 64-5 64.7 1.469 64.8 65.0 65-1 65-3 65-4 65-6 65-7 65-9 66.1 66.2 loo FOOD INSPECTION yIND ANALYSIS. EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC- TOMETER READINGS— (CowimMeJ). Refrac- Fourth Decimal of «/>_ tive Index, ^D. 1 2 3 4 5 6 7 8 9 SCALE READINGS 1.470 66.4 66.5 ^6.7 66.8 67.0 67.2 67-3 67-5 67.7 67.8 1. 471 68.0 68.1 68.3 68.4 68.6 68.7 68.9 69 I 69.2 69.4 1.472 69.5 69.7 69.9 70.0 70.2 70-3 70-5 70 7 70.8 71.0 1-473 71. 1 71-3 71-4 71.6 71.8 71.9 72.1 72 2 72-4 72-5 1.474 72.7 72.9 73-0 73-2 73-3 73-5 73-7 73 8 74.0 74.1 I -475 74-3 74-5 74.6 7 + -8 75 -o 75-1 75-3 75 5 75-6 75-8 1.476 76.0 76.1 76-3 76.5 76-7 76.8 77.0 77 2 77-3 77-5 1-477 77-7 77-9 78.1 78.2 78.4 78.6 78-7 78 9 79.1 79-2 1.478 79-4 79.6 79-8 80.0 80.1 80-3 80.5 80 6 80.8 81.0 1.479 81.2 81.3 81.5 81.7 81.9 82.0 82.2 82 4 82.5 82.7 1.480 82.9 83.1 83.2 83-4 83.6 83.8 83-9 84 I 84-3 84.5 1. 481 84.6 84.8 85-0 85-2 85-3 85-5 85-7 85 9 86.0 86.2 1.482 86.4 86.6 86.7 86.9 87.1 87 3 87-5 87 6 87.8 88.0 1-483 88.2 88.3 88.5 88.7 88.9 89 I 89.2 89 4 89.6 89. 8 1.484 90.0 90.2 90-3 90-5 90.7 90 9 91. 1 91 2 91.4 91.6 1=485 91.8 92.0 92.1 92-3 92.5 92 7 92.9 93 93-2 93-4 1.486 93-6 93-8 94.0 94-1 94-3 94 5 94-7 94 8 95-0 95-2 1-487 95-4 95-6 95-8 96.0 96.1 96 3 96.6 96 7 96.9 97.0 1.488 97-2 97-4 97-6 97-8 98.0 98 r 98-3 98 5 9S-7 98.9 1.489 99.1 99-2 99-4 99.6 99-8 100. The Critical Line. — It should be remembered that the instrument is primarily intended for use with butter, and that the prisms are so con- structed that the critical line of pure butter is colorless, while various other fats and oils, notably oleomargarine, which have greater dispersive powers than natural butter, show a colored critical line. When too great dis- persion is apparent to render possible an accurate reading, or when the critical Hne presents very broad fringes, as with linseed oil, poppyseed oil, turpentine, etc., use a sodium light, obtained by the application of table salt to the Bunsen gas flame, or the diffused daylight may be re-" fleeted in the mirror through a flat bottle filled with a dilute solution of potassium bichromate, to give a yellow light. The advantages of the refractometer for examination of fats and oils consist in the convenience with which very accurate determinations of the refractive index may be made at any temperature between 10° and 50'^ C, inclusive of thermal variations of refractive powers, and also in the possibility which it affords of distinguishing substances by their different dispersive powers, rendered visible by the different coloring of the critical line, a red-colored critical line being indicative of a relatively low dispersive power, a blue line of relatively high dispersion. S-l r//c REFRACT OMETER. 107 " si-i^ - Fig. 40. — Comparative Re- fractometer Scale, t Manufactured by Messrs. London. Variation of Reading with the Tem-perature.^ No definite temperature has been adopted as a standard for readings of this instrument, but it is easy to reduce readings at any temperature to terms of any other temperature for purposes of comparison. While the change in index of re- fraction for 1° C. is the same whatever the temperature, as Tolman and Munson have pointed out,* the change in scale reading per 1° C. de- creases as the temperature increases, and varies slightly with different oils. For correcting read- ing R' at a temperature T to a reading R at temperature T, their formula is R=-R' — X(T — T), X being the change in scale reading due to change of 1° C. in temperature. For butter, oleomargarine, beef tallow, lard, and other fats reading from 40° to 50° or there- abouts on the scale, A' = 0.55. For oils reading between 60° and 70°, like olive, mustard, rapeseed, cottonseed, peanut, etc., X = 0.58, and for oils read- ing between 70° and 80°, like corn oil, X = o.62. The slide rub f shown in Fig. 40, for use with the refractometer, has been jointly devised by H, C. Lythgoe and the writer, to render unnecessarj' the use of tables or formulas. The extreme upper and lower scale divisions indicate indices of re- fraction, and adjacent to these are the scale divisions indicating readings on the butyro- refractometer. By comparison, therefore, the values of either the Abbe or the butyro scale may be readily ascertained in terms of the other. The sliding scale, expressing temperature readings in degrees centigrade, is intended to be used in connection with the adjacent scale of butyro-refractometer readings, to readily express the butyro-scale reading of any fat or oil taken at a given temperature, in terms of that at any other temperature. This is frequently convenient * Jour. Am. Chem. Soc, XXIV, p. 755. Baird and TaJock, Ltd., 14 Cross Street, Hatton Garden, io8 FOOD INSPECTION AND ANALYSIS. in comparing the work of various observers, where different temperatures have been employed. The correction for change in n^ on the scale is 0.000365 for 1° C, being based on the experimental work of Tolman, Long, Proctor, Lythgoe, and the author. THE ABBE REFRACTOMETER. This instrument, Fig. 41, has a much wider range in reading than either the butyro or the WoUny instruments already described, read- FiG. 41. — The Abbe Refractometer with Temperature-controlled Prisms. ing as it does to the fourth decimal between the limits of 1.3 and 1.7 in indices of refraction. The equivalent readings of the Wollny milk fat refractometer, in indices of refraction, range from 1.3332 to 1.4220, while those of the butyro instrument run from 1.4220 to 1.4895- The Abbe instrument is thus necessary for use with the high-refracting essential THE REFRACT OMETER. 109 oils. Its construction is such that the prisms can withstand a higher heat than in the case of the butyro-refractometer, and it is hence better adapted for the examination of samples having a high melting-point, such as beeswax and paraffin. An advantage of the Abbe over the butyro instrument lies in the fact that the wide dispersion, inevitable when read- ing many substances on the butyro, may be entirely compensated for with the Abbe, and a clear sharp line be obtained. The construction of the prisms in relation to the heating jacket is similar in both instruments, and a film of the substance to be examined is held in the same manner between the surfaces of the prisms. Construction and Manipulation. — The Abbe refractometer is mainly composed of the following parts (see Fig. 41) : I. The double Abbe prism AB, which contains the fluid and can be rotated on a horizontal axis by means of an alidade. • 2. A telescope OF for observing the border-line of the total reflec- tion which is formed in the prism. 3. A sector S, rigidly connected with the telescope, on which divisions representing refractive indices are engraved. The double prism {AB, Fig. 41) consists of two similar prisms of flint-glass, each cemented into a metal mount and having a refractive index ^£,= 1.75. The former of the two prisms, that farthest from the telescope, which can be folded up or removed, serves solely for the purpose of illumination, while the border-line is formed in the second flint prism. A few drops of the fluid to be investigated is deposited between the two adjoining inner faces of the prisms in the form of a thin stratum, about 0.15 mm. thick. The double prism is opened and closed by means of a screw-head V, which acts in the manner of a bayonet catch. In order to apply a small quantity of fluid to the prisms without opening the casing, the screw V is slackened and a few drops of fluid poured into the funnel- shaped aperture of a narrow passage, not seen in the figure. On again tightening the screw, the fluid is distributed by capillary action over the entire space between the two prisms. This arrangement facili- tates the investigation of rapidly evaporating fluids, such as ether solu- tions. In the case of viscous fluids (resins, etc.) , a drop of moderate size is applied with a glass rod to the dull prism surface, the double prism being opened for the purpose. The prisms are then closed again, and before the measurement is proceeded with, the refractometer is left standing for a few minutes in order to compensate for any cooling or heating of the prisms which might occur while they were separated. no FOOD INSPECTION AND ANALYSIS. The arrangement for controlling the tempt^rature of the prisms of the Abbe refractometer is essentially after Dr. R. Wollny's plan of enclos- ing the prisms in a metal casing with double walls, through which water of a given temperature is circulated. The border-line is brought within the field of the telescope OF by rotating the double prism by means of the alidade in the following manner: Holding the sector, the alidade is moved from the initial position at which the index points to ^^=1.3, in the ascending scale of the refractive indices until the originally entirely illuminated field of view is encroached upon from the direction of its lower half by a dark portion; the line dividing the bright and the dark half of the field then is the "border-line." When daylight or lamplight is being employed, the border-line, owing to the total reflection and the refraction caused by the second prism, assumes at first the appearance of a band of color, which is quite unsuitable for any exact process of adjustment. The conversion of this band of color into a colorless line sharply dividing the bright and dark portions of the field is the work of the compen- sator, which consists of two similar Amici prisms of direct vision for the J9-line, and rotated simultaneously, though in opposite directions, round the axis of the telescope by means of the screw-head M. The dispersion of the border-line, which appears in the telescope as a band of color, can thus be counteracted by rotating the screw-head M till the equal but opposite dispersions are neutralized, making the line color- less and sharp. The border-line is now adjusted upon the point of intersection of the crossed lines by slightly inclining the double prism to the telescope by means of the alidade. The position of the pointer on the graduation of the sector is then read by the aid of the magnifier attached to the alidade. The reading supplies the refractive index w^ of the substance under investigation without any computation, and with a degree of exactness approaching to within about two units of the fourth decimal. Simultaneously, the reading of the scale on the drum of the compensator {T in Fig. 41) enables the mean dispersion to be arrived at by means of a special table and a short process of computation. Influence of Temperature. — As the refractive index of fluids varies with their temperature, it is of importance to know the temperature of the fluid contained in the double prism during the process of measure- ment. If, therefore, it is desired to measure a fluid with the highest degree of accuracy attainable with the Abbe refractometer (to within one or THE REFR^CTCMETER. ill two units of the fourth decimal of w^^) , it is absolutely necessary to bring the fluid, or rather the double prism containing it, to a definite known temperature, and to be able to control this temperature so as to keep it constant to within some tenths of a degree for a period of several hours; hence a refractometer principally required for the investiga- tion of fluids must be provided with beatable prisms. The type of heater shown in Fig. 39. and described in connection with the butyro-refractometer on page 102, is equally adapted for con- trolling the temperature of the prisms in the Abbe instrument, the flow of water entering at D and passing out at E, Fig. 41. THE IMMERSION REFRACTOMETER. This form of refractometer is of more recent introduction than the others made by Zeiss, and has many features that especially commend it to the use of the food analyst. The construction of the immersion refrac- tometer is such that, as its name implies, it may be immersed directly in an almost endless variety of solutions, the strength of which, within limits, may- be determined by the degree of refraction read upon an arbitrary scale. Thus, for example, the strengths of various acids and of a variety of salt solutions used as reagents in the laboratory, as well as of formaldehyde, of sugars in solution, and of alcohol, are all capable of determination by the use of the immersion refractometer. Figure 42 shows the form used by the writer. P is a glass prism fixed in the lower end of the tube of the instrument, w^hile at the top of the tube is the ocular Oc, and just below this on a level with the vernier screw Z is the scale on which is read the degree of refraction of the liquid in which the prism P is immersed. The tube may be held in the hand and directly dipped in the liquid to be tested, this liquid being contained in a vessel with a translucent bottom, through which the light is reflected. The preferable method of use is, however, that shown in the cut. J. is a metal bath with inlet and outlet tubes, arranged whereby water is kept at a constant level. The water is maintained at a constant tem- perature by means of a controller of the same type as the refractometer heater shown in Fig. 39. In the bath A are immersed a number of beakers, containing the solutions to be tested. T" is a frame on which is hung the refractometer by means of the hook H, at just the right height to permit of the immersion of the prism P in the liquid in any of the beakers in the row beneath. Under this row of beakers the bottom of the tank is composed of a strip of ground glass, through which light is reflected by an adjustable pivoted mirror. 112 FOOD INSPECTION AND ANALYSIS. The temperature of the bath is noted by a delicate thermometer immersed therein, capable of reading to tenths of a degree. Returning to the main refractometer-tr.be, i? is a graduated ring or collar which is connected by a sleeve within the tube with a compound prism near the bottom, the construction being such that by turning the collar R one way or the other the chromatic aberration or dispersion of any liquid may be compensated for, and a clear-cut shadow or critical line projected across the scale. By the graduation on the collar R, the degree of Fig. 42. — The Zeiss Immersion Refractometer. dispersion may be read. Tenths of a degree on the main scale of the in- strument may be read with great accuracy by means of the vernier screw Z, graduated along its circumference, the screw being turned in each case till the critical line on the scale coincides with the nearest whole number. The scale of the instrument reads from — 5 to 105, corresponding to indices of refraction of from 1.32539 to 1.36640. It should be noted tb?t the index of refraction may be read with a greater degree of accuraxy on che immersion refractometer than on the Abbe instrument. THE REFRACT OMETER. IT3 Manipulation of the Immersion Refractometer. — Before using the instrument for the first time, it is necessary to see that the refractometer is correctly adjusted. For this purpose the bath A is placed with its long side parallel to the window and the mirror turned towards a bright sky, the bath is half filled v/ith tap-water, and a beaker filled with dis- tilled water is then placed in one of the five holes in the front row imme- diately above the mirror. Finally, the refractometer is hung by its hook H upon the wire frame, the prism being totally submerged in the water contained in the beaker. The whole apparatus is now allowed to stand for ten minutes, or until the distilled water has acquired the exact temperature of the bath, and the ocular is focussed upon the divisions of the scale by turning the milled zone of the ocular shell until the lines and numbers are seen quite distinctly, the mirror being adjusted so that the light of the bright sky is seen directly through the beaker. The upper part of the field from —5 to about 15 appears bright, and it is separated from the lower dark part by a sharp line of demarcation, if the index on the ring of the compensator stands at 5. SCALE READING AND INDEX OF REFRACTION OF DISTILLED WATER AT 10-30° C, ACCORDING TO WAGNER. Temper- Scale Index of nj) Differ- Temper- Scale Index of ttjy Differ- ature C. Reading. Refraction, ttj). ence for 1° c. ature C. Reading. Refraction, n^ ence for i" C. 30 II. 8 I. 33196 19 14.7 T- 333075 8-5 29 12. 1 1.33208 12.0 18 14 9 33316 8-5 28 12.4 1-332195 II-5 17-5 15 33320 :}«- 27 12.7 I-33231 II. 5 17 15 I 33324 26 13.0 1.33242 II. 16 15 3 3333^5 7-5 25 13-25 1-332525 10.5 15 15 5 33339 7-5 24 13-5 1.332625 10. 14 15 7 33346 7.0 23 13-75 1-33272 9-5 13 15 85 333525 6-5 22 14.0 I. 33281 9.0 12 16 33359 6.5 21 14-25 1.33290 9.0 II 16 15 33365 6.0 20 14-5 1-33299 0.0 10 16.3 1-333705 5-5 The reading is taken and the temperature of the distilled water noted. Reference to the above table will show if the refractometer is correctly adjusted. Should the average of several careful readings at a given temperature deviate from that contained in the table, the following should be resorted to: Readjustment of the Scale. — The ocular end of the refractometer hanging on the wire frame is grasped from behind with the thumb and forefinger of the left hand, the micrometer drum set to 10, and the steel 114 FOOD INSPECTION AND ANALYSIS. spike, housed in the case of the apparatus, inserted into one of the holes of the nickeled cross-holed screw lying on the inner side of the microm- eter drum. The spike is then turned anti-clockwise, as seen from the rear, whereupon the nickeled milled nut, which governs the micrometer, becomes loosened. The temperature of the distilled water in the beaker is taken once more to see that it has remained constant, and then the table (page 113) is consulted to find the "adjusting number" properly- belonging to the temperature indicated. By turning the spike, the border- line is brought exactly upon the integer scale division appertaining to the adjusting number, and the loose micrometer drum is turned so that the index accords with the decimal portion of the adjusting number. The drum is now held firmly with the thumb and forefinger of the left hand, while the nut is screwed up tight again by the right hand, taking care, however, that the drum does not wander off the index. Finally, the new adjustment is tested by repeated readings. Regulating the Temperature. — In many cases it suffices to allow water at the temperature of the room to flow slowly from a tank suspended high upon the wall through the bath. Should it be required, however, to maintain a given temperature (say 20° C.) for hours together con- stant to a tenth of a degree, which is frequently desirable if not actually necessary, a more elaborate temperature-regulating device should be employed. In cold weather, or when the tap-water has a lower tempera- ture than that desired, a refractometer heater of the type shown in Fig. 39, and described on page 102, is convenient. When, as in the summer, the tap-water temperature is higher than that desired for the refractometer bath, there are various ways of success- fully controlling the temperature at a lower degree. An ice-water tank placed above the level of the bath may be employed, the flow from which through the bath is carefully controlled by a pinch-cock or otherwise, or is allowed to mingle, under ciareful regulation before entering the bath, with the water from the tap direct or with that from the heater. Investigation of Solutions in Beakers in Bulk. — The first ten solutions are poured into beakers imtil two-thirds full, and the latter are immersed and brought to the temperature of the bath A. When the first five solu- tions have been measured, they are taken out of the water-bath and the second series of five beakers inserted in their place, bringing at the same time a third series into the water-bath. The second series are measured and so on. Small gummed labels on the outside prove quite satisfactory for numbering the beakers. It is absolutely necessary to THE REFRACTOMETER. 115 compare the temperature of the solutions in the beakers with the water- bath from time to time. After each immersion, the prism should be wiped dry with a clean, soft piece of old linen. Investigations of Solutions Excluded from Air. — Quickly evaporating liquids, for instance ether solutions, should be treated individually by means of the metal beaker adapted to fit the prism end of the refrac- tometer. To fill the beaker, the refractometer is held in the left hand with the prism pointing upwards, and the metal beaker (M, Fig. 42) is set and securely fastened by means of the bayonet joint. It is now filled quite full and the cover D carefully fitted and locked. The solution is now enclosed, air and water tight. The refractometer as before is hung upon the wire frame of the bath, with the metal beaker submerged in the bath. It is expedient to place the solutions before investigation in closed flasks in the nine unoccupied holes in the bath. After the measurement, the refractometer is held in the left hand with the prism pointing downwards, and the beaker together with its cover detached by giving a slight turn with the right hand. The solu- tion can be used for other purposes, since it has undergone no change in constitution. Finally, the cover is detached from the beaker, and cover, beaker, and prism cleaned by simple means, and the refractometer made ready for the reception of the next solution, as above. Investigations of Small Quantities of Solutions with the Auxiliary Prism. — When the solution does not occur in sufficiently large quan- tities for investigation in the glass beaker, or when the solution is too deeply colored, as in dark beers, molasses, etc., the auxiliary prism is used. As described under "Solutions Excluded from Air," the metal beaker without cover is fitted on the refractometer. The auxiliary prism is held horizontally, and, a few drops of the solution having been applied to the hypothenuse face, the prism is inserted into the metal beaker, held conveniently for the purpose, with its hypothenuse face laid upon the polished elliptical face of the refractometer prism, and then locked in by the cover. If an insufficient quantity of the solution has been taken, the margins of the out-spread drops lying between the two prisms can be recognized by looking through the window of the cover on which abuts the square polished end of the auxiliary prism. It is strongly recommended, wherever possible, to apply a sufficiency of the solution, so that the space between the prisms is completely filled, otherwise a loss in brilliancy occurs, and, under certain circumstances, an unavoidable ii6 FOOD INSPECTION AND ANALYSIS. TABLE OF INDICES OF REFRACTION, n^ (Compared with Scale Readings of Zeiss I mmersion R.efractomcter, according to Wagner.) Scale Scale Scale Scale Scale Read- "o- Read- M^. Read- "/)- Read- njj. Read- «£»- ing. ing. ing. 10.0 ing. ing. o.o 1.327360 5-0 1.329320 I. 331260 15.0 t- 333200 20.0 1. 335 1 68 O.I 1-327309 5-1 1-329350 10. 1 I. 331299 15 -t 1-333238 20.1 1-335^68 2 438 398 2 388 2 276 2 206 3 477 3 437 3 377 3 314 3 244 4 516 4 476 4 416 4 352 4 282 5 555 5 515 5 455 5 390 5 320 6 594 6 554 6 494 6 428 6 358 7 633 7 593 7 533 7 466 7 396 8 672 8 632 8 572 8 504 8 434 9 711 9 671 9 611 9 542 9 472 I.O 750 6.0 710 II. 650 16.0 580 21.0 510 I.I 1.327789 6.1 1.329749 II. I I. 331689 16. 1 r- 333619 21. 1 1-335549 2 828 2 788 2 728 2 658 2 588 3 867 3 827 3 767 3 697 3 627 4 906 4 866 4 806 4 736 4 666 5 945 5 905 5 845 5 775 5 705 6 984 6 944 6 884 6 814 6 744 7 1.328023 7 982 7 932 7 833 7 783 8 062 8 1 .330022 8 962 8 892 8 822 9 lOI 9 061 9 I. 332001 9 931 9 861 a.o 140 7.0 100 12.0 040 17.0 970 22.0 900 2.1 r. 328180 7-1 1-330139 12. 1 1.332078 17. 1 I . 334008 22.1 1-335938 2 220 2 178 2 116 2 046 2 976 3 657 3 217 3 154 3 084 3 I. 336014 4 300 4 256 4 192 4 122 4 052 5 340 5 295 5 230 5 160 5 090 6 380 6 334 6 2(58 6 198 6 128 7 420 7 373 7 304 7 236 7 166 8 460 8 412 8 344 8 274 8 204 9 500 9 451 9 382 9 312 9 242 3-0 540 8.0 490 13.0 420 18. c 350 23.0 280 3-1 1. 328:^79 8.T 1-330528 I3-I 1-332459 18. 1 I - 334389 23.1 1-33631? 2 618 2 566 2 498 2 428 2 358 3 657 3 604 3 537 3 467 3 397 4 696 4 642 4 576 4 506 4 436 5 735 5 680 5 615 5 545 5 475 6 774 6 718 6 654 6 584 6 514 7 813 7 756 7 693 7 623 7 553 8 852 8 794 8 732 8 662 8 592 9 891 9 832 9 771 9 701 9 631 4.0 930 9.0 870 14.0 810 19.0 740 24.0 670 4-1 1.328969 9.1 r . 330909 14. 1 1.332849 19. 1 1-334770 24.1 1.336708 2 1.329008 2 948 2 888 2 818 2 746 3 047 3 987 3 927 3 857 3 784 4 085 4 t. 331026 4 966 4 896 4 822 5 125 5 104 5 I - 333005 5 935 5 860 6 164 6 104 6 044 6 974 6 898 7 203 7 143 7 083 7 I -335013 7 936 8 242 8 182 8 122 8 052 8 974 9 281 9 221 9 161 9 09 1 9 I. 337012 5-0 320 10. 260 15.0 200 20.0 130 25.0 050 THB REhRACTOMETER. 1^7 TABLE OF INDICES OF REFRACTION, njj — {Continue^. Scale Scale 1 Scale Scale Scale Read- njj. Read- M^. Read- ♦»/)• Read- *»/>• Read- «z?. ing. ing. ing. ing. ing. 25.0 I • 337050 130.0 I . 338960 35-0 1 . 340860 40.0 1-342750 45 -O I - 344630 2S-I 1.337088 30.1 t. 338998 35-1 t . 340898 40.1 1.342788 45-1 I . 344667 2 126 2 1-339036 2 936 2 826 2 704 3 164 3 074 3 974 3 864 3 741 i. 202 4 112 4 1.341012 4 902 4 778 5 240 5 150 5 oso 5 940 5 818 6 278 6 1 88 6 088 6 978 6 852 7 316 7 226 7 126 7 I. 343016 7 889 8 354 8 264 8 164 8 054 8 Q26 9 392 9 302 9 202 9 092 9 963 26.0 430 31.0 340 36.0 240 41.0 130 46.0 I . 345000 26.1 t- 337468 3I-I 1-339378 36.x I. 341278 41. 1 [-343167 46. 1 1-345037 2 506 2 416 2 316 2 204 2 074 3 544 3 454 3 354 3 241 3 III 4 582 4 492 4 392 4 278 4 148 5 ■ 620 5 530 5 430 5 315 5 185 6 6^8 6 c;68 6 468 6 352 6 222 7 696 7 606 7 506 7 389 7 259 8 734 8 644 8 544 8 426 8 296 9 772 9 682 9 582 9 463 9 333 27.0 810 32.0 720 37-0 620 42.0 500 47.0 370 27.1 1-337849 32.1 1-339758 37-1 r-341657 42.1 1-343538 47.1 1.345408 2 888 2 796 2 694 2 576 2 446 3 927 3 834 3 731 3 614 3 484 4 966 4 872 4 768 4 652 4 522 5 r. 338005 5 910 5 80=; 5 690 5 560 6 044 6 948 6 842 6 728 6 598 7 083 7 986 7 879 7 766 7 636 8 122 8 1.340024 8 916 8 804 8 674 9 161 9 062 9 953 9 842 9 712 28.0 200 33-0 100 38.0 990 43 -o 880 48.0 750 28.1 1-338238 33-1 I. 340138 38.1 1.342028 43-1 I. 343918 48.1 1-345787 2 276 2 176 2 c66 2 956 2 824 3 3M 3 214 3 104 3 994 3 861 4 352 4 252 4 142 4 1-344032 4 898 5 390 5 290 =; 180 5 070 5 935 6 428 6 328 6 218 6 108 6 972 7 466 7 366 7 256 7 146 7 I . 346009 8 504 8 404 8 294 8 184 8 046 9 542 9 442 9 332 9 222 9 083 29.0 580 34-0 480 39-0 370 44 -o 260 49-0 120 20.1 1.338618 34-1 i.3^o';i8 .39 -I r. 342408 .14.1 X- 344297 49.1 I .346158 2 656 2 556 2 446 2 334 2 196 3 694 3 594 3 484 3 371 3 234 4 732 4 632 4 522 4 408 4 272 5 770 =; 670 5 560 5 445 5 310 6 808 6 708 6 598 6 482 6 348 7 846 "J 746 7 636 7 519 7 386 8 884 8 784 8 674 8 556 8 424 9 922 9 822 9 712 9 593 9 462 30.0 960 35-0 860 40.0 750 45-0 630 50.0 500 iiS FOOD INSPECTION AND ANALYSIS. TABLE OF INDICES OF REFRACTION, Uj^ — {Contiyiued). Scale Scale Scale Scale Scale Read- M^. Read- njj. Read- «/)- Read- ^D- Read- riQ. ing. ing. ing. ing. ing. 50.0 1-346500 55 -o 1.348360 60.0 1. 350210 65.0 1-352050 70.0 1-353880 50.1 I • 346537 55-1 1-348397 60. 1 1-350247 65.1 1.352087 70. 1 I-353917 2 574 2 434 2 284 2 124 2 954 3 611 3 471 3 321 3 161 3 991 4 648 4 508 4 358 4 198 4 I . 354028 5 685 5 545 5 395 5 235 5 065 6 722 6 582 6 432 6 272 6 102 7 759 7 619 7 469 7 309 7 139 8 796 8 656 8 506 8 346 8 176 9 833 9 693 9 543 9 383 9 213 51-0 870 56.0 730 61.0 580 66.0 420 71.0 250 51-1 1.346907 56.1 1.348767 61. 1 I. 350617 66.1 1-352457 71. 1 1.354286 2 944 2 804 2 654 2 494 2 322 3 q8i 3 841 3 691 3 531 3 358 4 I. 347018 4 878 4 728 4 568 4 394 5 055 5 915 5 765 5 605 5 430 6 092 6 952 6 802 6 642 6 466 7 129 7 989 7 839 7 67Q 7 502 8 166 8 1.349026 8 876 8 716 8 538 9 203 9 063 9 913 9 753 9 574 52.0 240 57-0 100 62.0 950 67.0 790 72.0 610 52.1 1-347277 57-1 t-349i37 62.1 1-350987 67.1 1.352827 72.1 1-354646 2 314 2 174 2 I. 351024 2 864 2 682 3 351 3 211 3 061 3 901 3 718 4 388 4 248 4 098 4 .. 938 4 754 5 425 5 285 5 135 5 975 5 790 6 462 6 312 6 172 6 1-353012 6 826 7 499 7 359 7 209 7 049 7 862 8 536 8 396 8 246 8 086 8 898 9 573 9 433 9 283 9 123 9 934 53-0 610 58.0 470 63.0 320 68.0 160 73-0 970 53-1 1-347647 58.1 1.349507 63.1 1-351357 68.1 I. 353196 73-1 1-355006 2 684 2 544 2 394 2 232 2 042 3 721 3 581 3 431 3 268 3 078 4 758 4 618 4 468 4 304 4 114 5 795 5 655 5 505 5 340 5 150 6 832 6 692 6 542 6 376 6 186 7 869 7 729 7 579 7 412 7 222 8 906 8 766 8 616 8 448 8 258 9 943 9 803 9 653 9 484 9 294 54-0 980 59-0 840 64.0 690 69.0 520 74.0 330 54-1 I. 3480 I 8 59-1 1.349877 64.1 I. 351726 69.1 1-353556 74-1 1-355366 2 056 2 914 2 762 2 592 2 402 3 C94 3 951 3 798 3 628 3 438 4 132 4 988 4 834 4 664 4 474 5 170 5 1-350025 5 870 5 700 5 510 6 208 6 062 6 906 6 736 6 546 7 246 7 099 7 942 7 772 7 582 8 284 8 136 8 978 8 808 8 618 9 322 9 173 9 I. 352014 9 844 9 659 55-0 360 60.0 210 65.0 050 70.0 880 75-0 690 THE REFR/1CTGMETER. 119 TABLE OF INDICES OF REFRACTION, tip — {Cont mued). Scale Scale 1 Scale Scale Scale Read- ^D- Read- "ZJ- Read- «£>- Read- njj. Read- n^. ing. ing. ing. ing. ing. 75-0 1-355690 80.0 1-357500 85.0 1 I - 359300 90.0 T .361090 95 -O 1 .362870 75-1 1-355727 80.1 r- 357536 85.1 1-359336 90. I r . 361126 95-1 1.362006 2 764 2 572 2 372 2 162 2 942 3 801 3 608 3 408 3 198 3 978 4 838 4 644 4 444 4 234 4 1 . 363014 5 875 5 680 5 480 5 270 5 050 6 gi2 6 716 6 516 6 306 6 086 7 949 7 752 7 552 7 312 7 122 8 986 8 788 8 588 8 378 8 158 9 1-356023 9 824 9 624 9 414 9 194 76.0 060 81.0 860 86.0 660 91 .0 450 96.0 230 76. 1 1.356096 81. 1 1-357896 86.1 I . 359696 91. 1 1.361486 96.1 1-363256 2 132 2 0^2 2 732 2 522 2 292 3 168 3 968 3 768 3 558 3 328 4 204 4 I . 358004 4 804 4 594 4 364 5 '240 5 040 5 840 5 630 5 400 6 276 6 076 6 876 6 666 6 436 7 312 7 112 7 912 7 702 7 472 8 348 8 148 8 948 8 738 8 518 9 384 9 184 9 984 9 774 9 554 77.0 420 82.0 220 87.0 I . 360020 92.0 810 97-0 590 77-1 1-356456 82.1 1.358256 87.1 1 .360056 92.1 1 361846 97-1 1.363625 2 492 2 292 2 092 2 882 2 660 3 528 3 328 3 128 3 918 3 695 4 564 4 364 4 164 4 954 4 730 5 600 5 400 5 200 5 990 5 765 6 636 6 436 6 236 6 1.362026 6 800 7 672 7 472 7 272 7 062 7 835 8 708 8 508 8 308 8 098 8 870 9 744 9 544 9 344 9 134 9 905 78.0 780 83-0 580 88.0 380 93-0 170 98.0 940 78.1 I. 356816 83.1 1.35S616 88.1 I .360416 93-1 1.362205 98.1 1-363975 2 852 2 652 2 452 2 240 2 1.364010 3 888 3 688 3 4S8 3 275 3 045 4 924 4 724 4 524 4 310 4 080 5 960 5 760 5 560 5 345 5 "5 6 996 6 796 6 596 6 380 6 160 7 1-35703-' 7 832 7 632 7 415 7 195 8 068 8 868 8 668 8 450 8 230 Q 104 9 904 9 704 9 485 9 265 79.0 140 84.0 940 89.0 740 94.0 520 99-0 290 79.1 1-357176 84.1 1-358976 89.1 1-360775 94-1 I 362555 99.1 1-364325 2 212 2 1.359012 2 810 2 590 2 360 3 248 3 048 3 845 3 625 3 395 4 284 4 084 4 880 4 660 4 430 5 320 5 120 5 915 5 695 5 465 6 356 6 156 6 950 6 730 6 500 7 392 7 192 7 985 7 765 7 535 8 428 8 228 8 I. 361020 8 800 8 570 9 464 9 264 9 055 9 835 9 605 80.0 500 85.0 300 90.0 090 95 870 100.0 640 123 FOOD INSPECTION AND ANALYSIS. degradation of the sharpness of the border-hne. On the other hand, with a sufficient quantity of solution, the border-hne is surprisingly sharp. The refractometer is now suspended on the frame, and the measure- ment proceeded with as before described. After measurement, the cover is first removed, and the prism allowed to fall into the hollow of the hand, then the beaker is removed to enable the refractometer to be conveniently cleaned. Strengths of Various Solutions. — The most extensive work on the quantitative determination of the strength of a large number of common aqueous solutions with the immersion refractometer has been done by Wagner, who has published a large number of tables. These tables show the percentage strength (grams per loo cc. at 17.5° C.) of a large number of salt solutions and of acids, corresponding to the range of scale readings of the instrument, as well as of cane sugar, dextrose, formalde- SCALE READINGS ON IMMERSION REFRACTOMETER OF VARIOUS STAND- ARD REAGENTS USED IN VOLUMETRIC ANALYSIS* Temperature C. :5°. 16°. 17°. 17.5°. 18°. 19°. 20°. 21°. 22' Hydrochloric acid: Nonnal Tenth-normal Sulphuric acid: Normal Fifth-normal Tenth-normal Oxalic acid: Half-normal Tenth-normal Potassium bitartrate: Tenth-normal Potassium hydroxide: Normal Tenth-normal Sodium hydroxide: Tenth-normal Sodium thiosulphate; Tenth-normal Potassium bichromate: Tenth-norma 1 Silver nitrate; Tenth -normal Sodium chloride: Tenth-normal Ammonium sulphocyanate: Tenih-normal ■ 90 4,", ■ .4518. .5018. .20^24. •75 I?. . 20,20. .20 18. .60 20. 36-95 17.40 30.20 18.40 16.75 22. 10 16.75 17-35 43.40 18.10 18.15 23-85 17-35 19.85 17.80 20.25 36.7036 17. 20 17 I 29.95129 i8.20!i8 16.55 21 .90 16.55 17-15 43.10 17.90 17-95 23-65 17-15 19.65 17.60 20.05 20 7,S ,8016 I ,5029 ,8017 ■I5!i5 I ,5021 i5|i5 75;i6 50 42 5017 95:35 55ji6 25; 29 55 17 9015 ! 25 21 9015 1 , 5016 20 41 25ii7 3017 95 16 * According to Wagner, all these solutions were made up at 17.5° C. Readings at different tein« peratures are given for convenience. THE REFR^CTOMETER. I2i hyde, alcohol, etc. All these observations have been based on the ]\Iohr liter, at a temperature of 17.5°. More convenient for the American analyst would be tables based on the use of a higher temperature, say 20°, and the analyst is recommended to work out his own standards for com- parison, at the temperature best suited to his special locality and conven- ience. The instrument is especially useful in preparing normal and tenth- normal solutions. The table on page 1 20, from Wagner, shows the strength of various common laboratory reagents. SCALE READINGS AT TEMPERATURES FROM 10-30° C. Corrected to 17.5°, According to Wagner. No. - 2. 3. 4- 5- 6. 7. 8. 9- 10. II. 12 & 13. No. icj Scale Reading at 17.5° C. feu 15. 20. 25. 30. 35. 40. 45. SO. 60. 70. 80. 90 & 100. £5 30 •3.20 3-15 3-25 3-40 3-55 3-65 3-9° 4-05 4.20 4.60 4.80 5-25 30 29 28 27 26 2.90 I. 60 i.30 J. 00 2.85 2-55 2.25 1.95 2.95 2.65 2-35 2.05 3.10 2.80 2.50 2.20 3-25 2-95 2.65 2-35 3-35 3-05 2-75 2-45 3-55 3-25 2-95 2-55 3-75 3-45 3-15 2.80 3-90 3.60 3-30 2-95 4-25 3-90 3-5° 3.10 4-45 4.10 3-75 3-2,° 4-85 4-5° 4. 10 3-65 29 28 27 26 25 i-7S 1-75 1.80 1.90 2.05 2-15 2.25 2.45 2.60 2.70 2-95 3.20 25 24 23 22 21 ■i 50 1 25 I, JO 0.75 1-45 1-25 1 .00 0.75 1-55 1.30 1.05 0.80 1.60 1-35 1 . 10 0.85 1-75 1-45 0.90 1.85 1-55 1.25 0-95 1-95 1.65 1.30 1.05 2. It) I -75 1 .40 1.03 2.25 1 .90 1-55 1.20 2-35 2.00 1.65 1-25 2-55 2-15 1-75 1-35 2.75 2-35 1.90 1-45 24 23 22 21 20 0.50 0.50 0-55 0.60 0.65 0.65 0.75 0-75 0.85 0.90 0-95 1.05 20 19 18 0.3c 0. 10 0.30 O.IO 0.30 0. 10 0-35 0.15 0.40 o.is 0.4c 0.15 0.45 0-15 0.45 0.15 0.45 0.15 0-55 0.20 0.55 0.20 0.60 0.20 19 18 17.5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 17-5 17 16 — 0. 10 0.30 O.IO' O.IO 0.30I 0.30 0. 10 0.30 0. 10 0-35 O.IO 0.35 0.15 0.40 0.15 0.45 0.15 0-45 0.15 0.50 0.20 0-55 0. 20 0-55 17 16 15 0.50 0.45I 0.45 0.50 0.60 0.60 0.65 0.75 0-75 0.80 0.85 0.90 15 14 13 0. 70 0.85 1 .00 1-15 0.60 0.60 0.75 0-75 0.70 0.85 0.80 1. 00 0.85 1 .10 0.90 0-95 1.20 1.05 1-35 1 .10 1 .40 1.25 1-55 1-25 1.60 14 13 12 II 1 1 . 25 No. I. 2. 3- 4- s- 6. 7- 8. 9- 10. II. :2 & 13. No, FOOD INSPECTION /IND ANALYSIS. REFERENCES ON THE BUTYRO-REFRACTOMETER. Lythgoe, H. C. The Optical Properties of Castor Oil, Cod-liver Oil, Neats-foot Oil, and a few Essential Oils. Jour. Am. Chem. Soc, 27, 1905, p. 887. Schneider, C, and Blumenfeld, S. Beitrag zur Kenntnis animalischer Fette. Chem. Zeit., 30, 1906, p. 53. Sprinkmeyer, H., and Wagner, H. Beitrage zur Kenntnis des Sesamoles. Zeits. Unters. Nahr. Genuss., 10, 1905, p. 347. Ulzer, F., and Sommer, F. Uber» den Nachweis und die Bestimmung des Paraffins in Mischungen mit Ceresin. Chem. Zeit., 30, 1906, p. 142. REFERENCES ON THE WOLLNY MILK FAT REFRACTOMETER. Baier, E. Untersuchungen iiber den Nachweis der Wasserung von Milch mit Hilfe des Refraktometers. Ber. d. Nahr. Unters. d. Landw. f. d. Provinz Branden- burg, 1904, p. 14. Ueber die Zuverlassigkeit der Milchuntersuchungen mit dem Milch-refraktometer von Zeiss-Wollny. Molk. Zeit., 15, 1905, p. 386. CoTHEREAU, A. Nachweis einer Milchwasserung mittels des Refraktometers. Bull. Sci. Pharni., 7, 1905, p. 68. Henseval, M., and Mullie, G. La Refractometrie du Lait. Rev. gen. du Lait, 4, 1905, p. 529. REFERENCES ON THE ABBE REFRACTOMETER. Harvey, T. F. Temperature Corrections for Use with the Abbe Refractometer, and Refractive Indices of some Fixed and Essential Oils. Jour. Soc. Chem. Ind., 24, 1905, P- 717- Lythgoe, H. C. The Optical Properties of Castor Oil, Cod-liver Oil, Neats-foot Oil, and a Few Essential Oils. Jour. Am. Chem. Soc, 27, 1905, p. 887. Utz, Fr. Beitrage zur Untersuchung von Amylalkohol. AUgemeine Chem. Zeit., 6, 1906, p. 106. • Die Untersuchung von Spiritus mittels des Refraktometers. Pharm. Nach., I, 1906, p. 74. REFERENCES ON THE IMMERSION REFRACTOMETER. AcKERMANN, E. Ueber refraktometrische Bieranalyse. Zeits. f. d. ges. Brauw., 28, 1905, p. 441. Methode refractometrique rapide d'analyse de la biere a I'aide d'un calculateur automatique. Ann. et Rev. de Chim. Anal., 1905, p. 171. AcKERMANN, E., et VON Spindler, O. Sur la Determination de I'Extrait de la Bierre. Jour. Suisse de Chim. et Pharm., 1903, No. 30. Hanus, J., and Chocensky, K. Anwendung des Zeisschen Eintauchrefraktometers in der Nahrungsmittelanalyse. Zeits. Unters. Nahr. Genuss., 11, 1906, p. 313. THE REFRACTOMETER. 1-3 Leach, A. E., and Lythgoe, H. C. The Detection and Determination of Ethyl and Methyl Alcohols in Mixtures by the Immersion Refractometer. Jour. Am. Chem. Soc, 27, 1905, p. 964. A Comparative Refractometer Scale for Use with Fats and Oils. Jour. Am. Chem. Soc, 26, 1904, p. 1193. The Detection of Watered Milk. Ibid., p. 1195. KiONKA, H. Ueber natiirliche und kiinstliche Mineralwasser. Balneolog. Zeit., 14, Nos. 34 u. 35. Mansfeld, M. Die Verwendbarkeit des Zeiss'schen Eintauchrefractometer bei Nahrungsmittel-Untersuchung. Unters. Anst. osters. Apoth.-Vereins. Ber., 1904-1905, p. 10. Matthes, H. Quantitative BestLmmungen wasseriger Losungen mit dem Zeiss'- schen Eintauch-Refraktometer. Zeits. Unters. Nahr. Genuss., 5, 1902, p. 1037. Ueber refraktometrische analytische Bestimmungsmethoden. Zeits. anal. Chem., 13. 1904, P- 73 ■ MoHR, M. Die Anwendung des Zeiss'schen Eintauchrefraktometers im Brauereilabo- ratorium. Wochens. Brau., 22, 1905, p. 616. MoHR, O'. Refraktometrische Extraktbestimmung bei der Malzanalyse. Wochens. f. Brau., 23, 1906, p. 136. Wagner, B. Neue Methoden der quantitativen Bestimmung mit dem Zeiss'schen Eintauchrefraktometer. Zeits. offentl. Chem., 11, 1905, p. 404. Ueber quantitative Bestimmungen wasseriger Losungen mit dem Zeiss' -schen Eintauch-Refraktometer. Sondershausen, 1903. Tabellen zum Eintauch-Refraktometer. Sondershausen, 1907. Wagner, B., and Rinck, A. Neue Methode der quantitativen Zuckerbestimmung mit dem Zeiss'schen Eintauchrefraktometer. Chem. Zeit., 30, 1906, p. 38. Zeits. Chem. Apparat, Berlin, i, 1906, p. 207. CHAPTER VII. MILK AND ITS PRODUCTS. MILK. Nature and Composition. — Milk is the secretion of the mammary glands of female mammals for the nourishment of their young. Con- taining as it does all the requisites for a complete food, i.e., sugar, fat, proteins, and mineral ingredients, combined in appropriate proportion, there is ample reason why it occupies so high a place in the scale of human foods. It is a yellowish- white opaque fluid, denser than water, contain- ing in complete solution the sugar, soluble albumin, and mineral content, and, in less complete solution, the casein, while the fat-globules are held in suspension in the serum, forming an emulsion. The specific gravity of pure milk ranges from 1.027 to 1.035. Milk from various animals has the same general physical properties and the same ingredients, differing, however, in percentage composition. Of all the varieties, the milk of the cow is by far the most important from its universal use, and, unless otherwise qualified, the term milk wherever it occurs in this volume will be understood to mean cow's milk. Acidity. — When perfectly fresh, milk of carnivorous mammals is, as a rule, acid in reaction, while human milk and that of the herbivora is alkaline. Cow's milk, when freshly drawn, is more often amphoteric in reaction, i.e., it reacts acid with blue and alkaline with red litmus. It soon becomes distinctly acid, and the acidity increases as the milk sugar grad- ually becomes converted into lactic acid. Microscopical Appearance. — Under the microscope pure milk shows a conglomeration of various-sized fat globules having a pearly lustre. These globules vary from o.ooi to o.oi mm. in diameter, averaging about 0.005 mm. When examined under very high powers, it is possible to distinguish bacteria in the milk, the number to be seen depending greatly on the time that has elapsed since the milk was drawn from its source, as well as on the surroundings, the conditions of handling, exposure, etc. 124 MILK. 125 Color. — The yellow color of milk is imparted to it by the fat globules, and varies greatly in milk from ditTerent breeds of cattle, as well as in milk from the same cow at different seasons, being, as a rule, paler during the winter or stall-fed months, and having its greatest intensity soon after the cow is put out to pasture. Milk Sugar, the carbohydrate of milk, is normally present in amounts varying from 3 to 5 per cent. For the properties of milk sugar see page 577. The Proteins of Milk.^Co^em constitutes about 8o'"f, of the entire proteins of milk, being present in an average sample to the extent of about 39c- It exists in combination with calcium phosphate, and probably does not form a perfect solution in the milk, but is rather diffused therein in a somewhat colloidal form, being so finely divided, however, as to be incapable of separation by filtration while the milk is fresh. Pure casein is a white, odorless, and tasteless solid, sparingly soluble in water-, and insoluble in ether and alcohol. It is readily soluble in dilute alkalies. Strong acids also dissolve it, but its character is changed. From alkaline solution it is precipitated without change by neutralizing with acid. Its solutions are Isevo-rotary. Lact-alhumin is the soluble albumin of milk, existing therein to the extent of about 0.6% and forming about 15% or more of the milk proteins. It much resembles the albumin of eggs, being coagulated at 70° to 75° C. It is readily soluble in water. Its specific rotary power according to Bechamp is [a]D= ""67.5. Lac to globulin has been discovered by Emmerling as a constituent in milk, but exists in traces only. According to Babcock, it may be separated from milk whey by carefully neutralizing with sodium hydroxide, and afterwards saturating with magnesium sulphate. It much resembles the globulin of blood serum, being coagulated at 67° to 76° C. Fibrin. — Babcock has discovered in milk very minute traces of a substance analogous to the fibrin of blood. This substance, it is claimed, forms a part of the slime found in the separator-bowl of a centrifugal skimmer. Other Nitrogenous Substances. — Besides the above norm.al constituents of milk, certain bodies may be formed by proteolytic action during fer- mentation, such, for example, as caseoses and peptones, formed for the most part by the decomposition of a part of the casein. Galactin is a gelatin-Uke body of the nature of peptone, occurring in traces in milk. Besides these, minute traces of amido-bodies, such as creatin and urea, are sometimes present, and also ammonia. [25 FOOD INSPECTION AND ANALYSIS. to o o u H W H O O K o .s H ^ o 1 g O Ph d :3 cy^ ^ W b-c 3 rt ol oj « o o u •- C o u .S " o rt ii c^ td :2 rl .■:i U < 1-1 O Ph S u ■^ o o o M o M o o o o M 8 o o o o o o °^.v. .2 s s u r/l T m hf -n n CJ n Ph C/D o ^ hi; c75 Ph U PQ MILK. 127 Milk Fat. — Fat forms the most variable constituent of milk, being found in proportions ranging from 2.5 to 7 per cent. For the chemical composition and characteristics of milk fats see Butter (p. 529). The fat globules are held in suspension in the milk and have long been thought to be surrounded each by a thin nitrogenous membrane, known as StorcJi's mucoid protein, which becomes broken on churning. This theor}', while rendered probable by many of the phenomena connected with the dair}', is by no means universally held at present. Citric Acid has been found to exist in milk, probably in combina- tion with certain of the mineral constituents, being present to the extent of about o.i9c- The table on page 126 arranged by Babcock shows quite clearly the percentage composition of an average cow's milk. For comparison of milk from different animals the following table * is inserted, showing in most cases minimum, maximum, and mean deter- minations from a large number of actual analvses: No. of c -c. Anal- I Specific yses. Gravity. Water. Casein. Albu- min. Total Pro- teids. Fat. Milk Sugar. Ash. Cow's milk 800 Minimum. Maximum. Mean. . . Human milk. Minimum. Maximum. Mean. . . Goat's milk [ 200 Minimum. Maximum. Mean. . . Ewe's milk. . Minimum. Maximum. Mean. . . Mare's milk . Mean. . Ass's milk . . Mean. . . 32 47 5 1.0264 1.0370 1-0315 1.027 1.032 .0280 .0360 -0305 1-0385 I. 0341 1-0347 1.036 80.32 90.32 87.27 81.09 91.40 87.41 82.02 90.16 85-71 1.0298 : 74.47 87.02 80.82 90.78 89.64 1-79 6.29 3.02 1.96 1.03 2-44 3-94 3.20 3-59 5-69 4.97 1.24 0.67 0.25 1-44 0-53 0.32 2.36 I -26 2.01 1.09 0.83 1-77 1-55 0-75 1-55 2.07 6.40 3-55 4-29 6.52 1-99 2.22 1.67 6.47 3-64 0.69 1.43 4.70 6.83 2.29 3.78 3.10 7-55 4-78 2.81 9.80 6.86 1. 21 1.64 2. II 6.12 4-88 3-88 8.34 6.21 3.26 5-77 4.46 0-35 1. 21 0.71 0.12 1.90 0.31 0-39 1.06 0.76 2.76 0.13 7-95 1-72 4.91 0.89 5-67 ] 0.35 5.99 I 0.51 Composition of the Ash of Milk. — The ash of milk does not truly represent the mineral content, since, in the process of incineration, the character of some of the constituents is altered by oxidation and otherwise. Expressed in parts per 100, the ash of the typical milk sample whose fuU analysis is given on page 126 would be about as follows: * Compiled from Konig's Chemie der mens. Nahr. u. Genuss. 128 FOOD INSPECTION AND ANALYSIS. Potassium oxide 25 . 02 Sodium " 10.01 Calcium " 20.01 IMagnesium " 2.42 Iron " 0-13 Sulphur trioxide 3 - S4 Phosphoric pentoxide 24 . 29 Chlorine 14. 28 100.00 Soldner regards the following as more nearly representing the propor- tion in which the mineral salts exist in milk: Per Cent. Sodium chloride, NaCl 10.62 Potassium clJoride, KCl 9.16 Mono-potassium phosphate, KHaPO^ 12.77 Di-potassium phosphate, K2HPO^ 9.22 Potassium citrate, K3(CgH507)2 5-47 Di-magnesium phosphate, MgHPO^ 3.71 Magnesium citrate, Mg3(CgH50^)2 4.05 Di-calcium phosphate, CaHPO^ 7.42 Tri-calcium phosphate, Ca3(POj2 • - 8.90 Calcium citrate, Ca3(C,.H50^)2 23.55 Lime, combined with proteins 5.13 100.00 Fore Milk and Strippings. — Unless a portion drawn from the well- mixed or whole complete milking of an animal is taken for analysis, one does not get a fair representative sample of the milk, for it is a well-known fact that the first portion of milk drawn from the udder, termed the ' ' fore milk," is very low in fat, while the last portions or "strippings" con- tain a very high fat content, sometimes exceeding 10% fat. The following analyses show the difference between fore milk and strippings in two cases : (r) Fore milk. Strappings, (2) Fore milk. Strippings. Per Cent Water. 88.17 80.82 88.73 80.37 Per Cent Solids. 11.8^ 19.18 II .27 19.63 Per Cent Fat. 1.32 9-63 1.07 10.36 MILK. 129 The per cent of albuminoids, sugar, and ash is nearly the same in both fore milk and strippings. Colostrum. — The milk given by cows and other mammals for two or three days after the birth of young is termed colostrum, and differs ma- terially in composition from normal milk. It is yellow in color, of an oily consistency, and has a pungent taste. It acts as a purge upon the young. Examined under the microscope, it is found to contain large circular cells larger than fat globules and somewhat similar to blood corpuscles. It is very high in albumin, which seems to be similar to blood albumin. The following analyses were made by Engling, showing the composition of colostrum from a cow eight years old: Time after Calving. Immediately After 10 hours " 24 " " 48 " specific Gravity. Fat. Casein. Albu- min. Sugar. Ash. 1.068 3-54 2.65 16.56 3.00 1. 18 1.046 4.66 4.28 9-32 1.42 T--SS 1.043 4-75 4-50 6.25 2.85 1.02 1.042 4.21 3-25 2-31 3-46 0.96 1-035 4.08 3-32, 1-03 4.10 0.82 Total Solids. 26.93 21.23 19-37 14.19 13-36 The average of twenty-two analyses of colostrum from different cows by EngHng showed total solids 28.31, fat 3.37, casein 4.83, albumin 15.85, sugar 2.48, ash 1.78. Frozen Milk. — Since it is the water in milk that freezes, it follows that in partially frozen milk the unfrozen portion of the milk, or that part w^hich remains still liquid, becomes concentrated by the process of freezing. This is borne out by the following figures of Richmond: * Frozen Portion, Unfrozen Portion, Per Cent. Per Cent. Water 96-23 85.62 Fat :.23 4.73 Sugar 1.42 4.95 Proteins 91 3 -90 Ash 21 .80 Specific gravity i . 0090 i . 0345 Fermentations of Milk. — These are due to the action of bacteria of various kinds, the most common being the lactic fermentation. The Souring of Milk is caused by the action of a large number of species of acid-forming bacteria, chief among which is the Bacillus acidi lactici, which multiplies faster than other bacteria in raw milk under * Analyst, XVIII. p. 53. -ijo FOOD INSPECTION AND ANALYSIS. favorable conditions of temperature. Part of the milk sugar is acted on and transformed, first into dextrose and galactose, the latter sugar subsequently forming lactic acid, as follows: (1 ) C,3H,,0,,,H30 = QH,,0«+ C,H,30« Lactose Dextrose Galactose (2) C,H,30« = 2C3H,03 Galactose Lactic acid More and more acid is formed until the casein can no longer be held up, curdling ensues, and the casein is precipitated. Finally, after a certain degree of acidity is reached, the ferment is killed and the action stops. Other acids than lactic are also undoubtedly produced, since a small part of the acid in sour milk is found to be volatile. According to Conn "^ the volatile acids are acetic and formic. Abnormal Fermentation. — Through the agency of micro-organisms that may develop under certain conditions, various changes are produced in milk that to some extent alter its character. Thus hitter milk is some- times produced as the result of some organism as yet but little understood. Occasionally milk is found possessing a peculiarly thick and slimy consistency, whereby it may be drawn out in threads, by dipping a spoon into the milk and withdrawing it therefrom. This is termed ropy milk, and is more often met with in warm weather. It is undoubtedly produced as a result of bacterial action. Enzyme- j or ming Bacteria are not uncommonly developed in milk, causing various proteolytic changes, whereby the casein is partially trans- formed into peptones, cascoses, etc. Chromogenic Bacteria are the agencies that produce peculiar pigments in milk. Thus red milk is due to Bacillus erythrogenes; yellow milk to Bacillus xynxanthus; blue milk to Bacillus cyanagenes. The latter is quite common, appearing ordinarily in patches in the milk. CHEMICAL ANALYSIS OF MILK. Ordinarily, in ascertaining the nutritive value of milk, one determines its specific gravity, total solids, fat, protein, milk sugar, and ash. Occa- sionally it is thought desirable to make a distinction in the case of protein between the casein and the albumin. Rarely is it necessary to further subdivide the nitrogenous bodies in milk, unless in connection with a special study of the proteolytic changes which it undergoes. The total solids, fat, and ash are usually all determined directly, and, * U. S. Dept. of Agric, Off. of Exp. Stations, Bui. 25, p. 21. MILK. 131 £«M in the case of the milk sugar and the proteins, a determination of either one may be directly made (whichever is most convenient), the other being calculated by difference. WTien foreign ingredients or adulterants are present in milk, special methods are employed to detect them. Preparation of the Sample. — In procuring a sample for analysis, the greatest care is necessary to insure a homogeneous sample. By far the best method in every case, where possible, is to pour the milk back and forth from one vessel to another (i.e., pour from the original container into an empty vessel and back at least once). Where this is impossible from the size of the container or for any other reason, the milk should be thoroughly mixed with a dipper. A " sampler," of which the Scovell samp- ling-tube I Fig. 43, A) is a convenient form, also aids in securing a representative sample, and is invaluable when it is desirable to secure a definite fraction of the whole for a composite sample. This instrument consists of a brass or copper tube made in two parts which telescope accurately together as shown in Fig. 43, A, the lower part being closed at the bottom, but provi'ded with three or more lateral slits. The sampler, draw^n out to its full length, is carefully inserted in the tank containing the milk and lowered to the bottom, after which the upper part is pressed down over the lower so as to close the slits, and the tube is then lifted out of the tank, containing a fairly representative sample of the milk. In all operations to which a milk sample is submitted during the process of analysis, it should invariably be poured into a clean empty vessel and back, whenever it has been at rest for an appreciable time, in order to insure a homogeneous mixture. Determination of Specific Gravity. — This is most readily obtained with the aid of a hydrometer, accurately graduated within the Hmits of the widest possible varia- tion in the specific gravity of milk. Hydrometers for special use with milk are known as lactometers, and are graduated variously. One of the most convenient forms of this instrument is the Quevenne lactometer, graduated from 15° to 40°, corresponding to specific gravity 1.015 to 1.040. This J I B Fig. 43. A, Scovell Milk- sampling Tube. B, Quevenne Lac- tometer. 132 FOOD INSPECTION AND ANALYSIS. instrument, shown in Fig. 43, B, has a thermometer combined with it, the stem containing a double scale, on the lower part of which the specific gravity is read, while the temperature is read from the upper part. Another form of instrument is termed the New York Board of Health lactometer, which is not graduated to read the specific gravity directly, but has an arbitrary scale divided into 120 equal parts, the zero being equal to the specific gravity of water, while 100 corresponds to a specific gravity of 1.029. '^o convert readings on the New York Board of Health scale to Quevenne degrees they must be multiplied by .29. QUEVENNE LACTOMETER DEGREES CORRESPONDING TO NEW YORK BOARD OF HEALTH LACTOMETER DEGREES. Board of Health Degrees. Quevenne Scale. Board of Health Degrees. Quevenne Scale. Board of Health Degrees. Quevenne Scale. 60 17.4 81 23-5 lOI 29-3 61 17.7 82 23.8 102 29.6 62 18.0 83 24.1 103 29.9 63 18.3 84 24.4 104 30.2 64 18.6 85 24.6 105 30-5 65 18.8 86 24.9 106 30-7 66 19. 1 87 25.2 107 31-0 67 19.4 88 25-5 108 31-3 68 19.7 89 25.8 109 31.6 69 20.0 90 26.1 no 31-9 70 20.3 9t 26.4 III 32.2 71 20.6 92 26.7 112 32.5 72 20.9 93 27.0 113 32-8 73 21.2 94 27-3 114 zz--^ 74 21.5 95 27.6 115 33-4, 75 21.7 96 27.8 116 Z2>-(^ 76 22.0 97 28.1 117 33-9 77 22.3 98 28.4 IlS 34.2 78 22.6 99 28.7 119 34-5 79 22.9 100 29.0 120 34-8 80 23.2 If extreme accuracy is desired, the Westphal balance or the pycnometer should be used for the determination of specific gravity. For ordinary cases, however, the lactometer, if carefully made, is sufficiently accurate. With any other form of lactometer than the Quevenne, a separate thermometer is necessary in order to determine the temperature, the common practice being to standardize all such instruments at 60° F. (15.6° C). Readings at temperatures other than 60° may be corrected to that temperature by the aid of the table on page 133. DETERMINATION OF TOTAL SOLIDS. — Dish Method. — For purposes of milk analysis, platinum dishes are by far the most desirable. These, if made for the purpose, should be of the shape shown in Fig. 51, measur- MILK. 133 FOR CORRECTING THE SPECIFIC GRAVITY OF MILK ACCORDING TO TEMPERATURE (BY DR. PAUL VIETH). Degrees Degrees of Thermometer (Fahrenheit). of L actom- eter. 45 46 47 48 49 5° 51 52 S3 54 55 S6 57 s8 59 60 20 19.0 19.0 19. 1 19. 1 19.2 19.2 19.3 19-4 19.4 19-5 19.619.7 19.8 19.9 19.9 — 21 19-O 20.0 20.0 20.1 20.2 20.2 20.3 20.3 20.4 20 -.s 20.6 20.7 20.8 20.9 20.9 — 22 20.9 21.0 21.0 21. 1 21.2 21 .2 21.3 21.3 21.4 21-5 21.6 21.7 21.8 21. q 21.9 — 23 21.9 22.0 22.0 22.1 22.2 22.2 22.3 22-3 22.4 22.5 22.6 22-7 22.8 22.8 22.9 — 24 22.9 22.9 23.0 23.1 23-2 23-223.3 23-3 23-4 23-5 23.6 23.6 23-7 23.8 23-9 — 25 ;^3-8 23-9 24.0 24.0 24.1 24.1 24.2 24-3 24-4 24.5 24.6 24.6 24-7 24.8 24-9 — 26 124-8 24.9 24-9 25.0 25-1 25-1 25.2 25.2 25-3 25-4 25-5 2^.6 25.7 2S.8 2<;.q — 27 25.8 25-9 25-9 26.0 26.1 26.1 26.2 26.2 26.3 26.4 26. s 26.6 26.7 26.8 26.9 — 28 26.7 26.8 2b. 8 26.9 27.0 27.027.1 27.2 27-3 27.4 27-5 27.6 27.7 27.8 27. Q — 29 ,27-7 27.8 27.8 27-9 28.0 28.0 28.1 28.2 28.3 28.4 28. s 28.6 28.7 28.8 28.9 — 30 28.6 28.7 28.7 28.8 28.9 29.0 29.1 .•.•9. I 29.2 29-3 29.4 29.6 29-7 29.8 29.9 — 31 29.5 29.6 29.6 29.7 29.8 29.9.30.0 30.1 30.2 30-3 30-4 30.5 30.6 30.8 30-9 — 32 30-4 30-5 30-5 30.6 30-7 30.931.0 3I-I 31.2 3^-3 31-4 31-5 31.6 31-7 31-9 — 33 3^-3 31-4 31-4 31-531-6 31.8 31.9 32-0 32.1 32-3 32-4 32-5 32.6 32-7 32.9 — 34 32,2 32-3 32-3 34-4'32.5 32-732-9 33-0 33-'^ 33-2 33-3 33-5 33-6 33-7 33-9 — 35 33-0 33-T- 33-2 33-4 33-5 33-633-8 33-9 34-0 34-2 34-3 34-5 34-6 34-7 34-9 ~ 61 62 63 64 6s 66 67 1 68 69 70 71 72 73 74 75 20 20.l'20.2 20.2 20.3 20.420.5 20.6 20.7 20.9 21.0 21. 1 21.2 21.3 21.5 21.6 21 21. I 21.2 21.3 21.4 21.5 21.6 21.7 21.8 22.0 22.1 22.2 22.3 22.4 22.5 22.6 22 22.1 22.2 22.3 22.4 22.5 22.6 22.7 22.8 23.0 23.1 23-2 23.3 23-4 23.5 23-7 23 23-1123-2 23-3 23-4 23-5 23-6 23.7 23.8 24.0 24.1 24.2 24.3 24.4 24.6 24.7 24 24.1 24.2 24-3 24-4|24-5i24-6 24.7 24-9 25.0 25.1 25.2 25-3 25.5 25.6 25-7 25 25.1 25.2 25-3 25-4 25-5!25-6 25-7 25-9 26.0 26.1 26.2 26.4 26. s 26.6 26.8 26 26.1 26.2 26.326.5 26.6 26.7 26.8 27.0 27.1 27.2 27-3 27-4 27-5 27-7 27.8 27 27.1 27.3 27-4|27.5 27.627.7 27.8 28.0 28.1 28.2 28.^ 28.4 28.628.7 28.0 28 28.1 28.3 28.4 28.5128.628.7 28.8I29.0 29.1 29.2 29.4 29-5 29.729.8 29-9 29 29.1 29-3 29.4 29.5 29.6 29.8 29.930.1 30.230.3 30.4 30.5 30-730.9 31 -o 30 30-1 30.3 30-4 30-5 30-7 30-8 30-9:31-1 3I-23I-3 31.5 31.6 31.8 31-9 32.1 31 31.2 3-^-3 31-4 3i-5 3i-7;3i-7 3I.8J32.0 32.232.4 32.5 32.6 32.8 33-0 33-1 32 32-2 32-3 32-5 32.6132.7 32.9 33.0,33-2 33-333-4 33.6 33.7 33-9 34.0 34-2 33 33-2 33-3 33-5 33-633-833-9 34.034-2 34.3 34.5 34.6 34.7 34-9 35.1 3S-2 34 34-2 34-3 34-5 34-6 34.834.935.035.2 35.3!3S.5 3^.6 35-8 36.0 36.1 ^6.3 35 35-2 35-3 35-5 35-6 35-8|35-9 36-1 36.2 36.436.5 36.7 36.8 37-0 37.2 37-3 ing about 2f inches in diameter at the top, and 2\ inches in diameter at the bottom, having carefully rounded rather than square edges, and being h inch deep. The bottom is not perfectly flat, but slightly crowned outward. Such a dish will hold about 35 cc. For purposes of economy it is best to have these dishes spun out with a thick bottom, but with thin sides, not so thin, however, as to be too readily bent. If platinum dishes cannot be afforded, dishes of porcelain, glass, aluminum, nickel, or even tin may be used, but in all cases should be as thin as practicable. About 5 cc. of the thoroughly mixed sample of milk are carefully transferred by means of a pipette to a tared dish on the scale-pan, and its 174 FOOD INSPECTION AND ANALYSIS. weight accurately determined. The dish with its contents is then trans- ferred to a water-bath, being placed over an opening preferably but little smaller than the diameter of the bottom of the dish, so that as large a surface as possible is in contact with the live steam of the bath. Here it is kept for at least two hours, after which the dish is wiped dry while still hot, transferred to a desiccator, cooled, and weighed.* Babcock Asbestos Method. | — Provide a hollow cylinder of perforated sheet metal, 60 mm. long and 20 mm. in diameter, closed 5 mm. from one end by a disk of the same material. The perforations should be about 0.7 mm. in diameter and about 0.7 mm. apart. Fill loosely with from 1.5 to 2.5 grams of freshly ignited, woolly asbestos, free from fine and brittle material, cool in a desiccator, and weigh. Introduce a weighed quantity of milk (between 3 and 5 grams) , and dry in a water- oven to constant weight, which is usually reached after four hours' heating. DETERMINATION OF ASH. — The platinum dish containing the milk residue, obtained in the determination of total sohds by the dish method described above, is next placed upon a suitable support above a Bunsen flame (a platinum triangle or a ring stand is convenient for this), and the residue is ignited at a dull-red heat to a perfectly white ash, after which it is cooled and weighed. DETERMINATION OF FAT.— The Adams Method. — Without doubt the most accurate method of fat determination is by extraction with ether. For this purpose a strip of fat-free filter-paper about 2^ inches wide and 22 inches long is rolled into a coil and held in place by a wire as shown in Fig. 44. Schleicher and Schiill furnish fat-free strips especially for this work, but it is very easy to prepare the strips and extract them with theSoxhlet apparatus. About 5 grams of milk are run into a beaker with a pipette, and the weight of the beaker and milk are determined. The coil is then intro- duced into the beaker, holding it by the wire in such a manner that as * It is a common practice to transfer the milk residue, after a preliminary drying on the water-bath, to an air-oven, kept at a temperature of from ioo° to 105°, where it is dried to a constant weight; but after an experience in analyzing over 30,000 samples of milk, the author is prepared to state that in his opinion the results obtained by the above method of procedure, using the water-bath alone, are more satisfactory. It is impossible to keep a milk residue at a temperature above 100° for any length of time without its undergoing decomposition, especially as to its sugar content, as is shown by the darkening in color. A milk residue should be nearly pure white, a brownish color showing incipient decomposi- tion. Hence, by continued heating, especially at the temperature of 105°, the residue would continue to lose weight almost indefinitely. If it is thought best to give a final drying in the air-oven, the time should be short and the temperature employed should not in any case exceed 100°. t A. O. A. C. method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 117. MILK. 135 much as possible of the milk is absorbed by the paper. It is often possible to take up almost the last drop of the milk. By then weighing the beaker, the amount of milk absorbed by the coil is determined by difference, and the paper coil is hung up and dried, first in the air and then in the oven, at a temperature not exceeding 100°. Another method of charging the paper coil consists in suspending it by the wire and gradually deliver- ing upon it 5 cc. of the milk from a pipette, the density of (f^ the milk being known. The coil containing the dried residue is then transferred to the Soxhlet extraction apparatus (see p. 64) and sub- jected to continuous extraction with anhydrous ether for at least two hours, the receiving-flask being first accurately weighed. The tared flask with its contents is freed from all remaining ether, first on the water-bath and finally in the air-oven. It is then cooled and weighed, the increase in weight representing the fat in the amount of milk ab- sorbed by the coil. If there is any doubt about all the fat having been extractdd at first, the process of extraction may be continued till there is no longer a gain in weight of the flask. Experience soon shows the length of time necessary for the complete extraction, which of course depends on the degree of heat employed, and the fre- quency with which the extracting-tube overflows. Two hours is ample for most cases, in which the conditions are such that the ether siphons over from the extraction-tube ten times per hour. Babcock Asbestos Method.* — Extract the residue from the deter- mination of water by the Babcock asbestos method with anhydrous ether in a continuous extraction apparatus, until all the fat is removed, which usually requires two hours. Evaporate the ether, dry the fat in the extrac- tion flask at the temperature of boiling water, and weigh. The fat may also be determined by difference, drying the extracted cylinders at the temperature of boiling water. Fat Methods Based on Centrifugal Separation. — These methods are the most practicable for commercial work and for use by the public analyst, since they are much more rapid, and, if carefully carried out, practically as accurate as the Adams method. They all depend upon the use of a centrifugal machine, having hinged pockets in which are carried graduated bottles, into each of which a measured quantity of milk is introduced. The milk is then subjected to the action of a suitable reagent, which dissolves the casein and liberates the fat in FiG, 44. — The Adams Milk- fat Coil. * A. O. A. C. method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 119. 136 FOOD INSPECTION AND ANALYSIS. a pure state, after which, by whirHng at a high speed, the pockets are thrown out horizontally and the milk fat driven into the neck of each bottle, where the amount is directly read. Various processes of this kind, each having its own special adherents, are in extensive use, among which the best known are the Babcock, the Leffman and Beam, the Gerber, and the Stokes. A resume of these processes, showing the reagents employed and other comparative data, is thus tabulated by Allen.* Milk Sulphuric acid, volume " " specific gravity Hydrochloric acid Amyl alcohol Babcock. 17.5 cc. 17.5 cc. 1. 831 to 1.834 None None Leffman- Beam. Gerber. Stokes. CC. cc. 1.5 cc. 1-5 cc. II cc. 10 cc. 1.82 to 1.825 None i.o cc. 15 cc. 13^ cc. 1.82 to 1.83 None 1-5 cc. The Babcock Process, devised originally for the use of creameries and dairymen, is now extensively employed for fat determination in the laboratory. It has stood the test of over ten years' successful use in the writer's hands. During this time on various occasions results as determined have been compared with those obtained by the Adams process, and the agreement has been as close as could be expected. The following figures show the results of such comparative determinations made in duplicate on three samples of milk, viz., a whole pure milk, (i) and (2); a watered milk, (3) and (4), and a milk centrifugally skimmed, (5) and (6). COMPARATIVE FAT DETERMINATION BY ADAMS-SOXHLET AND BY BABCOCK PROCESSES. Per Cent of Fat by the Adams-Soxh- let Process. Per Cent of Fat by the Babcock Process. \. whole milk (i)................ 4-27 4.28 2.70 2-74 0.16 0.14 4-30 4-35 2.70 2.80 C.15 O.IS (2) (4) A skimmed milk (?) (6) The Centrifuge. — Various styles of centrifuge, carrying from 2 to 40 bottles, are in use for this process. Two forms of hand machine are shown in Fig. 45, one {D), for two bottles, arranged to screw on the edge of a table, the other for twelve bottles inclosed in a cast-iron case. Commercial Organic Analysis, 3 Ed., Vol. IV, p. 150. MILK. 137 Fig. 45. — Apparatus for Babcock Test. A, Burrell's electric centrifuge; B, Burrell's steam turbine centrifuge; C and D, Burrell's hand centrifuges; E, milk bottle; F, Wagner's skim-milk bottle; G, Swedish or combined acid bottle. 138 . FOOD INSPECTION AND ANALYSIS. The steam turbine machines (Fig. 45, B) are simple in construction and the steam serves to keep the bottles warm as well as to furnish power. The steam impinges against a series of paddles on the outer periphery of the revolving frame, driving it like a horizontal water-wheel. A reverse steam jet, steam gauge, and hot-water tank for filling the bottles are also provided. Fig. 45, A shows an electric machine for 24 to 36 bottles. Laboratory centrifuges are also provided with frames for Babcock bottles. Glassware. — The ordinary test bottle for milk is shown in Fig. 45, E. It has graduations corresponding to from o to 10% of fat, using 17.6 cc, of milk. One of various forms of skim milk bottle is also shown (F), The graduated tube has a capacity corresponding to only 0.25% for its entire length, hence the need of a second tube of larger bore for filling. The pipettes are graduated to hold 17.6 cc, which for average milk weighs 18 grams. The lower tube should be of such a size as to enter the neck of the test bottle. A 17.5 cc. cylinder is provided for measuring the acid, but where considerable numbers of tests are made some special measuring device is desirable. Fig. 45, G shows a combined acid bottle and pipette, the latter being filled by tipping up the bottle. Manipulation. — Pipette 17.6 cc. (corresponding to 18 grams) of the milk into the test bottle and add 17.5 cc. of commercial sulphuric acid. (sp.gr. 1. 82-1. 84). Mix thoroughly by a vigorous rotatory movement holding the neck of the bottle between the fingers and at a slight angle away from the body. The lumps of curd which at first form disappear upon shaking; much heat is developed during the mixing and the color changes to deep brown. Place the test bottles in the pockets of the centrifuge (symmetrically arranged to keep the revolving frame in balance) and whirl at the rate of 800 to 1000 revolutions per minute, according to the diameter of the frame, for 5 minutes. Stop the machine, fill each bottle up to the neck with boiling water and whirl for two minutes longer. Add boiling water up to near the top of the graduation and whirl finally for two minutes. Remove the bottles from the machine and take the readings of the bottom and the very top of the fat column, the difference being the per cent of fat. If desired, the percentage may be obtained directly by means of calipers. To avoid danger of cooling it is well to immerse the bottles nearly to the top of the neck in water at 60° C, removing one at a time for reading. MILK. 139 The Werner-Schmidt Method. — Ten cc. of milk are introduced by means of a pipette into a large test-tube of 50 cc. capacity, and 10 cc. of concentrated hydrochloric acid are added. The mixture is shaken and heated till the liquid turns a dark brown, either by direct boiling for a minute or two, or by immersing the tube in boiling water for from five to ten minutes. The tube is then cooled by im- mersion in cold water, and 30 cc. of washed ether is added. The tube is closed by a cork provided with tubes similar to a wash-bottle, the larger tube being adapted to slide up and down in the cork, and preferably being .urned up shghtly at the bottom. The contents of the tube are shaken, the ether layer allowed to separate, and the sliding-tube arranged so that it terminates slightly above the junction of the two layers. The ether is then blown out into a weighed flask. A second and a third portion of ether of 10 cc. each are successively shaken with the acid liquid and added to the contents of the weighed flask, from which the ether is subse- quently evaporated and the weight of the fat easily obtained. F1G.46.— TheWemer-Schmidt Instead of measuring the milk into the testinsf- ^ ppara us. tube, a known weight of milk may be operated on. A sour milk may be readily tested in this way, provided it is previously well mixed. Determination of Fat by the Wollny Milk-fat Refractometer.* — This instrument presents the same appearance as the butyro-refractometer, Fig. 38, with an arbitraiy scale reading from o to 100, the equivalent readings in indices of refraction of the Wollny instrument varying from 1.3332 to 1.4220. Exactly 30 cc. of the milk to be tested are measured into the stoppered flask A, Fig. 47. This may be done by the use of the automatic pipette, which holds exactly 7^ cc, removing four pipettes full of the milk. 5 is a numbered tin samphng-tube in which the milk sample is kept for convenience, and into which the automatic pipette readily fits. Having measured 30 cc. of the milk into the flask A, 12 drops of a solution of 70 grams potassium bichromate and 312.5 cc. of stronger ammonia in one liter of water may be added as a preservative. * Milch Zeit., 1900, pp. 50-53. I40 FOOD INSPECTION AND ANALYSIS. if the sample is to be kept for some time before finishing the test. Twelve drops of glacial acetic acid are added to curdle the milk. The flask is then corked and shaken for one to two minutes in a mechanical shaker, after which 3 cc. of a standard alkaline solution are added, and the flask corked and shaken for ten minutes in the mechanical shaker, the tempera- ture being kept at i7.5°C. The standard alkaline solution is prepared Fig. 47. — Accessories for Carrying Out the Wo liny Milk-fat Process. by dissolving 800 cc. of potassium hydroxide in a liter of water, adding 600 cc. of glycerin and 200 gramis pulverized copper hydrate, the mixture being allowed to stand for several days before using, shaking at intervals. Finally 6 cc. of water-saturated ether are added to the mixture in the flask, using for convenience the automatic pipette fitted in the corked bottle as shown. The flask is again shaken for fifteen minutes in the mechanical shaker, and whirled for three minutes in the centrifuge, after which a few drops of the ether solution are transferred to the refractometer, and the reading taken. The percentage of fat is obtained by means of the following table: MILK 141 PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE WOLLNY REFRACTOMETER. Scale Per Scale Per Scale Per Scale Per Scale Per Scale Per Rend- Cent Read- Cent Read- Cent Read- Cent Read- Cent Read- Cent ing. Fat. ing. Fat. ing. Fat. ing. Fat. ing. Fat. ing. Fat. 20.0 24-5 0.41 29.0 0.87 33-5 1-34 38.0 1-85 42.5 2.41 I 6 0.42 I 0.88 6 1-35 I 1.87 6 2.43 2 7 0-43 2 0.89 7 1-36 2 1.88 7 2-44 3 8 0.44 3 0.90 8 1-37 3 1.89 8 2.46 4 9 0-4S 4 0.91 9 1.38 4 1.90 9 2-47 5 25.0 0.46 5 0.92 34-0 1-39 5 1. 91 43-0 2.49 6 0.00 I 0.47 6 0-93 I 1.40 6 1.92 I 2.50 7 O.OI 2 0.48 7 0.94 2 1.42 7 1-93 2 2-51 8 0.02 3 0.49 8 0-95 3 1-43 8 1-94 3 2.52 9 0.03 4 0.50 9 0.96 4 1-44 9 1-95 4 2-54 21.0 0.04 5 0-51 30.0 0.97 5 1-45 39-0 1.96 5 2-55 I 0.05 6 0.52 I 0.98 6 1.46 I 1.98 6 2.56 2 0.06 7 0-53 2 0.99 7 1.47 2 1-99 7 2.58 3 0.08 8 0-54 3 1. 00 8 1.48 3 2.00 8 2.60 4 0.09 9 0-5S 4 1. 01 9 1-49 4 2.02 9 2.61 5 O.IO 26.0 0-57 5 1.02 35-0 1.50 5 2.03 44.0 2.63 6 O.II I 0.58 6 1.03 I I-51 6 2.04 . I 2.64 7 0.12 2 0-59 7 1.04 2 1.52 7 2.05 2 2.65 8 0.13 3 0.60 8 1-05 3 1-54 8 2.07 3 2.67 9 0.14 4 0.61 9 1.06 4 1-55 9 2.08 4 2.68 22.0 0.15 5 0.62 31.0 1.07 5 1.56 40.0 2.09 5 2.70 I 0.16 6 0.63 I 1.08 6 1-57 I 2.10 6 2.71 2 0.17 7 0.64 2 1.09 7 1-58 2 2.12 7 2.72 3 0.18 8 0.65 3 1. 10 8 1-59 3 2-13 8 2.74 4 0.19 9 0.66 4 I. II 9 1.60 4 2.14 9 2-75 5 0.20 27.0 0.67 5 I. 12 36.0 1. 61 5 2-15 45-0 2-77 6 0.21 I 0.68 6 I-I3 I 1.62 6 2.16 I 2.78 7 0.22 2 0.69 7 I. 14 2 1.64 7 2.18 2 2-79 8 0.23 3 0.70 8 1-15 3 1.65 8 2.20 3 2.80 9 0.24 4 0.71 9 I. 16 4 1.66 9 2.21 4 2.82 23.0 0.25 5 0.72 32.0 I. 17 5 1.67 41.0 2.23 5 2.84 I 0.26 6 0-73 I I. 18 6 1.68 I 2.24 6 2.85 2 0.27 7 0.74 2 I. 19 7 1.69 2 2.25 7 2.87 3 0.28 8 0-75 3 1.20 8 1.70 3 2.26 8 2.88 4 0.29 9 0.76 4 1.22 9 1. 71 4 2.27 9 2.89 5 0.30 28.0 0.77 5 1.23 37-0 1.72 5 2.28 46.0 2.90 6 0.31 I 0.78 6 1.24 I 1-73 6 2.30 I 2.92 7 0.32 2 0.79 7 1-^5 2 1-75 7 2.32 2 2-93 8 0-33 3 0.80 8 1.26 3 1.76 8 2-33 3 2.94 9 0-34 4 0.81 9 1.27 4 1.78 9 2-34 4 2.96 24.0 0.36 5 0.82 33-0 1.28 5 1-79 42.0 2-35 5 2.98 I 0-37 6 0.83 I 1.29 6 1.80 I 2-37 6 3.00 2 0.38 7 0.84 2 1.30 7 1. 81 2 2.38 7 3.01 3 0-39 8 0.85 3 I-3I 8 1.82 3 2-39 8 3.02 4 0.40 9 0.86 4 1.32 9 1.84 4 2.40 9 3-03 5 0.41 29.0 0.87 5 1-34 38.0 1-85 5 2.41 47.0 3-05 142 FOOD INSPECTION AND ANALYSIS. PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE WOLLNY REFRACTOMETER —{Continued). Scale Per Scale Per Scale Per Scale Per Scale Per Scale Per Read- Cent Read- Cent Read- Cent Read- Cent Read- Cent Read- Cent ing. Fat. ing. Fat. ing. Fat. ing. Fat. ing. Fat. ing. Fat. 47.0 3-05 50-5 3-59 54-0 4.18 57-5 4-78 61.0 5-44 64-5 6.14 I 3.06 6 3.60 I 4.20 6 4.80 I 5-46 6 6.16 2 3.08 7 3.61 2 4.22 7 4^82 2 5-48 7 6.18 3 3.10 8 3-63 3 4-23 8 4.84 3 5-50 8 6.20 4 3.12 9 3-64 4 4-25 9 4.86 4 5-52 9 6.22 5 3-14 51.0 3-66 5 4.26 58.0 4.88 5 5-54 65.0 6.24 6 3-iS 1 3-67 6 4.28 I 4.90 6 5-56 I 6.27 7 3-16 2 3-68 7 4-29 2 4.92 7 5-58 2 6.29 8 3-17 3 3-70 8 4-31 3 4-94 8 5.60 3 6.31 9 3.18 4 3-72 9 4-33 4 4-95 9 5-61 4 6.34 48.0 3.20 5 3-74 55-0 4-35 5 4-97 62.0 5-63 5 6-36 I 3-21 6 3-76 I 4.37 6 4-98 I 5-65 6 6.38 2 3-23 7 3-78 2 4-38 7 5.00 2 5-66 7 6.40 3 3-25 8 3-80 3 4.40 8 5.02 3 5-68 8 6.42 4 3-27 9 3.82 4 4-42 9 5-04 4 5-7° 9 6.44 5 3-28 52.0 3-84 5 4-43 59-0 5.06 5 5-72 66.0 6.46 6 3-30 I 3-85 6 4-44 I 5.08 6 5-74 7 3-32 2 3-87 7 4.46 2 5-10 7 5-76 8 3-33 3 3-89 8 4-48 3 5-II 8 5-78 9 3-34 4 3-90 9 4-49 4 5-13 9 5.80 49=0 3-36 5 3-92 56.0 4-51 5 5-15 63.0 5-82 I 3-38 6 3-93 I 4-53 6 5-17 ■• I 5 -84 2 3-40 7 3-95 2 4-55 7 5-19 2 5.86 3 3-42 8 3-97 3 4-57 8 5.20 3 5-88 4 3-43 9 3-99 4 4-59 9 5-22 4 5-90 5 3-44 53-0 4.01 5 4.60 60.0 5-24 S 5-92 6 3-45 I 4-03 6 4.61 I 5.26 6 5-94 7 3-46 2 4.04 7 4-63 2 5-28 7 5-96 8 3-48 3 4.06 8 4-65 3 5-30 8 5-98 9 3-50 4 4.07 9 4-67 4 5-32 9 6.00 50.0 3-51 5 4-09 57-0 4-69 5 5-34 64.0 6.02 I 3-53 6 4.10 I 4.71 6 5-36 I 6.04 2 3-55 7 4.12 2 4-73 7 5-38 2 6.07 3 3-56 8 4.14 3 4-75 8 5-40 3 6.09 4 3-57 9 4.16 4 4-76 9 5-42 4 6.12 5 3-59 54-0 4.18 5 4.78 61.0 5-44 5 6.14 The following table is of use for those who wish to employ the WoUny meihod, but have the Abbe refractometer instead of the milk-fat refractometer. MILK. 143 INDICES OF REFRACTION {tin) CORRESPONDING TO SCALE READINGS OP THE WOLLNY MILK-FAT REFRACTOMETER. Refrac- tive Index, 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 Fourth Decimal of n. Scale Readings. 2-7 3-7 4.6 5-6 6. 7- 8. 9- 10. II. 12.4 13-4 14.4 15-4 16.4 17.4 18.4 19.4 20.4 21 .4 22.4 23-4 24.4 25-4 26.4 27-5 28.5 29-5 30-5 31.6 32-7 33-7 34-8 35-8 36.9 38.0 39-0 40.1 41.2 42-3 43-3 44-4 45-6 46.7 0.0 0.1 0.: 0.9 I.O I. 1.9 2.0 2. 2.8 2-9 3-« 3-7 3-8 3-( 4-7 4-8 4-( 5-7 5-8 5-( 6.7 6.8 6.( 7-6 8.6 7-7 8-7 7-! 8.i 9-6 9-7 9.1 10.6 10.7 10. i 11-5 II. 6 II. 12.5 12.6 12. 13-5 13.6 13- 14-5 14.6 14. 15-5 15.6 15- 16.5 16.6 16. 17-5 18.S T7-6 18.6 17- 18. 19-5 19.6 19. 20.5 20.6 20. 21-5 21.6 21. 22-5 22.6 22. 23-S 23.6 23- 24-5 24.6 24- 25-5 25.6 25- 26.15 26.6 26. 27.6 28.6 27-7 28.7 27- 28. 29.6 29-7 .29. 30.6 30-7 30- 31-7 31-8 31- 32-8 32-9 33- 33-8 33-9 34- 34-9 36.0 35-0 36-1 35- 36. 37-0 38.1 37-1 38-2 37- 38- 39-2 39-3 39- 40.2 40.3 40. 41-3 41.4 41- 42-4 42.5 42. 43-4 43-6 43- 44-6 44-7 44- 45-7 46.8 45-8 46-9 45- 47- 0-3 1.2 2.1 3-1 4.0 5-0 6.0 6.9 7-9 8.9 9-9 10.9 II. 8 12.8 13.8 14.8 15.8 16.8 17.8 18.8 19.8 20.8 21.8 22.8 23.8 24.8 25-8 26.8 27.9 28.9 29-9 31.0 32.0 2,2,-'^ 34-2 35-2 36-3 37-3 38-4 39-5 40-5 41.6 42.7 43-8 44-9 46.0 47.1 0.4 0.5 0.5 0.6 1-3 1-4 1-5 1.6 2.2 2-3 2-4 2-5 3-2 Z-2, 3-4 2,-S 4-1 4-2 4-3 4-4 5-1 6.1 5-2 6.2 5-3 6.3 5-4 6.4 7.0 8.0 7-1 8.1 7-2 8.2 7-S 9.0 9-1 9-2 9-3 10. 10. 1 10.2 10-3 II. II. I II. 2 11-3 II. 9 12.0 12. 1 12.2- 12.9 13.0 I3-I 13. ? 13-9 14.0 14. I 14.2 14.9 15-9 15-0 16.0 I5-I 16.1 . 15-2 16.2 16.9 17.9 18.9 19.9 20.9 21.9 22.9 23-9 24.9 25-9 26.9 28.0 29.0 30.0 3I-I 32.1 34-3 35-3 36.4 37-4 38-5 39-6 40.7 41.8 42.8 43-9 45 -o 46.1 47-2 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.1 29.1 30.1 31.2 32.2 52,-3 34-4 35-4 36-5 37-6 38-6 39-7 40.8 41.9 42-9 44.0 45-1 46.2 47-3 17.1 18. 1 19. 1 20.1 21. 1 22.1 23.1 24.1 25-1 26.1 27.1 28.2 29.2 30.2 32-3 33-4 34-5 35-5 36.6 37-7 38-7 39-8 40.9 42.0 43-0 44-1 45-2 46.3 47-4 17.2- 18.2 19.2 20. 2: 21.2 22.2 23.2 24.2 25.2 26.2 27-3 28.3 29-3 30-3 31-4 32-4 33-5 34-6 35 ■ ;a= 153 -Ho 10 CD r- 00 o CO ■st- ^. 154 FOOD INSPECTION ^ND AN /I LYSIS. TABLE SHOWING PER CENT OF TOTAL SOLIDS IN MILK CORRESPONDING TO QUEVENNE LACTOMETER READINGS* AND PER CENT OF FAT.f Per Cent Lactometer Reading at 1 5.5° c. of Fat. 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 o.o 5.50 5.75 6.00 6. 2S 6. 50 6.75 7 . 00 7.2s 7.50 7-75 8.00 8.25 8.50 8-75 9 .00 O. I S.62 5.87 6.12 6.37 6.62 6.87 7.12 7.37 7.62 7.87 8.12 8.37 8.62 8.87 9.1 o. a 5-74 5-99 6. 24 6.49 6.74 6.99 7.24 7.49 7.74 7.90 8.24 8.49 8.74 8-99 9.24 0.3 5.86 6. II 6.36 6.61 6.86 7-11 7.36 7.61 7.86 8. II 8.36 8.61 8.86 9. II 9-36 0.4 5.98 6.23 6.48 6.73 6.98 7.23 7-48 7.73 7.98 8.23 8.48 8.73 8.99 9.23 9-48 o.S 6. 10 6.35 6.60 6.8s 7.10 7-35 7 .60 7-85 8.10 8. 35 8.60 8.85 9.10 9-35 9.60 0.6 6. 22 6.47 6.72 6.97 7.22 7-47 7.72 7-97 8.22 8.47 8.72 8.97 9. 22 9-47 9.72 0.7 6.34 6.59 6.84 7.09 7.34 7-59 7.84 8.09 8.34 8.59 8.84 9.09 9.34 9-59 9-84 0.8 6.46 6.71 6.96 7.21 7.46 7-71 7.96 8.21 8.46 8.71 8.96 9.21 9-46 9-71 9.96 0.9 6.58 6.83 7.08 7.33 7.58 7-83 8.08 8.33 8.58 8.83 9.08 9-33 9.58 9-83 10.08 1 .0 6. 70 6.95 7.20 7 -45 7.70 7-05 8.20 8.45 8.70 8.95 9. 20 9.45 9.70 9-95 10. 20 1 . 1 6.82 7.07 7-32 7-57 7.82 8.07 8.32 8.57 8. 82 9.07 9-32 9.57 9.82 10.07 10.32 1 . 2 6.94 7.19 7-44 7.69 7.94 8.19 8.44 8.69 8.94 9.19 9-44 9.69 9-94 10.19 10.44 1-3 7 .06 7.31 7.56 7.81 8.06 8.31 8.56 8.81 9.06 9-31 9.56 9.81 10. 06 10.31 10. 56 1.4 7.18 7.43 7.68 7-93 8.18 8.43 8.68 8.93 9.18 9.43 9.68 9-93 10.18 10.43 10.68 1.5 7 -30 7.55 7.80 8.05 8.30 8.55 8.80 9-05 9-30 9-55 9.80 10 .05 10. 30 10.55 10. 80 1.6 7.42 7.67 7.92 8.17 8.42 8.67 8.92 9.17 9.42 9.67 982 10.17 10.42 10.67 10.92 1.7 7-54 7.79 8.04 8.20 8.54 8.79 9.04 9.29 9.54 9-79 10.04 10 . 29 10. 54 10.79 1 1 .04 1.8 7.66 7.91 8.16 8.41 8.66 8.91 9. 16 9.41 9.66 9.91 10.16 10.41 10 . 66 10. 91 II. 17 1.9 7-78 8.03 8.28 8. S3 8.78 9.03 9.28 9-53 9.78 10.03 10. 28 10. 55 10.78 II .04 II . 29 2 .0 7.90 8.15 8.40 8.65 8.90 9.15 9.40 9-65 9-90 10. IS 10.40 10 . 66 10. 91 II .16 II .41 2. 1 8.02 8.27 8.52 8.77 9.02 9.27 9.52 9-77 10.02 10. 27 10.52 10.78 11 .03 11.28 11-53 2. 2 8.14 8.39 8.64 8.89 9.14 9.39 9.64 9.89 10. 14 10.39 10.64 10.90 II. 15 II .40 11-65 2.3 8.26 8.51 8.76 9.01 9. 26 9-51 9.76 10 . 01 10 . 26 10.51 10.76 11.02 11.27 11.52 11-77 a-4 8.38 8.63 8.88 9-13 9.38 9.63 9.88 10.13 10.38 10.63 10.88 1 1 . 14 11.39 II .64 11.89 2.5 8.50 8.75 9.00 9-25 9-50 9-75 10.00 10. 25 10.50 10.75 11.00 II . 26 II. 51 II .76 12.01 2.6 8.60 8.87 9.12 9-37 9. 62 9-87 10.12 10.37 10.62 10.87 11.12 11.38 II .63 11.88 12.13 2.7 8.74 8.99 9.24 9-49 9-74 9.99 10 . 24 10.49 10.74 10.99 11 . 24 11.50 II. -75 12.00 12.25 2.8 8.86 9.11 9.36 9.61 9.86 lO. II 10.36 10.61 10.86 1 1 . 1 1 11.37 11.62 11.87 I2.I2|l2.37 2.9 8.98 9-23 9.48 9-73 9-98 10.23 10.48 10.73 10.98 11.23 11.49 11-74 11-99 12.24 12.49 3-0 9. 10 9.35 9.60 9.85 10 . 10 10.35 10 . 60 10.85 II . 10 II . 36 11.61 11.86 12. 1 1 12. 36 12.61 31 9. 22 9.47 9.72 9.97 lO . 22 10.47 10. 72 10.97 11-23 1 1 .48 11.73 11.98 12.23 12.48 12.74 3-2 9-34 9.50 9.84 10 .09 10.34 10.59 10.84 1 1 .09 11-35 II .60 11.85 12.10 12.35 12.61 12.86 3-3 9.46 9.71 9.96 10. 21 10.46 10.71 10. 96 11.22 11.47 11.72 11.97 12.22 12.48 12.73 12.98 3-4 9-S8 9-83 10.08 10.33 10.58 10.83 II .09 11-34 11.59 11.84 12 .09 12.34 12. 60 12.85 13- 10 3-5 9.70 9.95 10. 20 10.45 10. 70 10.05 II . 21 II .46 II. 71 II .96 12.21 I 2 . 46 12.72 12.97 i3-2a 3-6 9.82 10.07 10.32 10.57 10.82 11.08 11.33 11.58 11-83 12.08 12.33 12.58 12.84 13.09 13-34 3-7 9-94 10. 29 10.44 10.79 10.94 II . 20 11-45 II . 70 11-95 12. 20 I 2 . 45 12.70 12 . 96 13.21 13-46 3-8 10.06 10.31 10.56 10.81 II .06 11.32 11-57 11.82 12.07 12.32 12 . 57 12.82 13-08 13-33 13-58 3-9 10.18 10.43 10.68 10.93 II. 18 11.44 II .69 11.94 12.19 12.44 12.69 12.94 13. 20 13-45 13-70 4.0 10.30 10.55 10. 80 II .05 11.30 ii-S6 II. 81 12. 06 12.31 12.56 12.81 13-06 13.32 13-57 13-83 4-1 10.42 10.67 10.92 II. 17 II .42 11.68 11-93 12.18 12.43 12.68 12.93 13.18 1 3 . 44 13.69 13-95 4-2 10.54 10.79 1 1 .04 II . 29 II . 54 11.80 12.05 12.30 12.55 12.80 13.05' 13 -31 13.56 13 . 82 14.07 4-3 10 . 06 10.91 II . 16 II .41 11.66 II .92 12.17 12 .42 12.67 12.92 13.18 13-43 13.68 13-94 14.19 4-4 10.78 11.03 11.28 11-53 11.78 12 .04 I 2 . 29 12.54 12.79 13.04 13.30 13.5s 13-80 14.06 14-31 4-5 10.90 11. IS 1 1 .40 11.65 II .90 12.16 12.41 12. 66 12.91 13.16 13.42 13.67 13-92 14.18 14-43 4.6 11.02 11.27 11.52 11.78 1 2 . 03 12.28 12-53 12.78 13.03 13.28 13.54 13.79 14.04 14.30 14-55 4-7 II . 14 1 1 .40 11.65 1 1 .90 12.15 1 2 .40 12.65 12.90 13.15 13-40 13.66 13-91 14.16 14.42 14.67 4.8 II . 27 11.52 11.77 12.02 12.27 12.52 12.77 13.02 13.27 13.52 13.78 14-03 14.28 14-54 14.79 4.9 11-39 II .64 11.89 12.14 12.39 12.64 12.89 13-14 13.39 13.64 13-90 14-15 14.40 14.66 14-91 S-o 11.51 II . 76 12.01 12. 26 12.51 12. 76 13.01 13-26 13.51 13.76 14.02 14.27 14-52 14.78 15.03 S-i U.63 11.88 12.13 12.38 12.63 12.88 13.13 13-38 13-63 13.89 14.14 14-39 14.64 14.90 15. IS 5-2 11.75 I 2 .00 12.25 12.50 12.75 13-00 13.25 13-50 13-75 14.01 14. 26 14-S1 14-76 15-02 15.27 5-3 11.87 12.12 12.37 12.62 12.87 13-12 13-37 13-62 13-87 14.13 14-38 14-63 14.88 15-14 15.39 5-4 11.99 12 . 24 12.49 12.74 12.99 13-24 13-49 13-71 14.00 14.25 14.50 14-76 IS. 01 IS- 26 15.51 S-5 12. II 12.36 12.61 12.86 13.11 13-36 i3-6i 13-86 14. 12 14-37 14.62 14.88 15-13 15.38 15-63 5.6 12. 23 I 2 .48 12.73 12.98 13-23 13.48 13-73 13-99 14.24 14.49 14-75 15.00 15.25 15.50 15.7s S-7 12.35 12.60 I 2.8s 13-10 13-35 13.60 13-85 14. II 14-36 14.61 14.87 15-12 15-37 iS-62 15.87 5-8 12.47 12.72 12.97 13. 22 13-47 13-72 13-97 14. 22 14.48 ^4-74 14-99 15-24 15-49 15-74 15.99 S-9 12.59 12.84 13.09 13-34 13.59 13-84 14. 10 14.35 14.60 1 4. -86 IS. II 15-36 IS-61 15.86 16. 13 6.0 12.71 12.96 13-21 13.46 13.71 13-96 14.22 14.47 14.72 14-98 15.23 15.48 15-73 15.98 16. 24 *The lactometer reading is expressed in whole numbers for convenience. The true specific gravity corresponding to a given lactometer reading is obtained by writing i.o before the lactometer reading. Thus, 1.026 is the specific gravity corresponding to lactometer reading 26, etc. tAn. Rep. Mass. State Board of Health, 1901, p. 445- (Analyst's Reprint, p. 25.) MILK. 155 the acidity of "sweet" milk is due partly to the presence of acid phos- phates and partly to dissolved carbonic acid in the milk, and not to lactic acid, which is probably absent, a better plan is to express the acidity in terms of the number of cubic centimeters of tenth-normal alkali necessary to neutralize a given quantity of the milk, either 25 or 50 cc, using phenol- phthalein as an indicator. If it is desired to calculate the acidity in terms of lactic acid, multiply the number of cubic centimeters il tenth-normal alkali used by 0.897, and divide by the number of cubic centimeters of milk titrated, the result being the percentage of lactic acid. Detection of Boiled Milk. — Starch's Method.^ — Shake 5 cc. of the milk in a test-tube with one drop of a 2% solution of hydrogen peroxide and two drops of a 2% solution of paraphenylenediamin. If the milk has not been heated beyond 80° C, a dark violet color appears at once, but if it has been pasteurized or boiled, no color appears. Siegfeld and Samson f find that addition of two drops of formalin (i : i) to each 100 cc. of milk previous to boiling causes it to react similar to raw milk. MODIFIED MILK. A comparison of the composition of cow's milk and human milk, as in the following table by Dr. Emmett Holt,J shows very marked differ- ences. Woman's Milk, Cow's Milk, Average. Average. Fat 4.00 3.50 Sugar 7.00 4.30 Proteins 1.50 4.00 Ash 0.20 0.70 Water 87.30 §7 -So The per cent of fat in the two kinds of milk is nearly the same. There is, however, too little sugar and an excess of proteins and ash in the milk of the cow, assuming human milk as the ideal infant food, so that in basing a diet for infants on the tasis of human milk considerable modi- fication is necessary. Moreover, aside from the actual variation in the amount of ingredients, there are certain inherent differences in the character of the same ingredient, as found in the milk of the cow and in * Copenhagen Expt. Sta., 40th Rep. f Molk. Ztg., 21, 1907, p. 103. J "Infancy and Childhood." iSJ FOOD INSPECTION AND ANALYSIS. human milk. The proteins of cow's milk are, for instance, found to be much more difficult of digestion than those of woman's milk, and the same is probably true of the fat. Aside from the mere statement of a few of these differences, it is obviously beyond the scope of this work to discuss this phase of the subject in detail, reference being made, how- ever, to such books as Dr. T. M. Rotch's "Pediatrics," and "Infancy and Childhood" by Dr. Emmett Holt, for full particulars. So great has been the demand by physicians for "modified milk" for infant feeding, that laboratories for this exclusive purpose have been established in many of the larger cities, in which not only is milk prepared in accordance with certain fixed formulae supposed to be adapted to average infants of varying age, but milk of any desired composition is prepared, in accordance with special prescriptions of physicians to apply to indi- vidual cases. Methods and Ingredients. — The proteins and the ash in cow's milk are much higher than in human milk, and both are brought to the proper degree of reduction by diluting the milk with water. Milk sugar is increased by the addition of lactose, and the fat is increased or diminished by addition of cream or by skimming. The dilution of cow's milk with a measured amount of water shows the following results on the proteins and ash: Cow's Milk. Diluted Once. Diluted Twice. Diluted Three Times. Diluted Four Times. Proteins Per cent. 4.0c 0.70 Per cent. 2.00 0-35 Per cent. 1-33 0.23 Per cent. I.OO 0.18 Per cent. 0.80 Ash 0.14 The ingredients commonly employed for modifying milk are (i) cream, containing 16% of fat, (2) centrifugally skimmed milk, otherwise known as "separator milk" from which the fat has been removed, (3) milk sugar, or a standard solution of milk sugar of, say, 20% strength, and (4) lime water. Unusual care should be taken in the selection of the milk supply to insure cleanness, purity, and freshness, as well as in the care of utensils, etc., used in the laboratory, which should in all cases be scrupulously clean. Samples prepared in accordance with a given formula or formulee are pasteurized in separate bottles, or, if desired, sterilized, and after stoppering with cotton are kept on ice. Formula. — It is obviously impossible to establish formulae univer- sally applicable even to healthy infants, but the following may be regarded as typical formulae, representing the composition of modified milk to suit the needs of an average growing infant during its first year: MILK. '^57 Period. Fat. Proteins. Sugar. Third to fourteenth day Second to sixth week Per cent. 2 2-5 3 3-5 4 3-5 Per cent. 0.6 0.8 I.o 1-5 2 20 Per cent. 6 6 6 7 7 3-5 Sixth to eleventh week Eleventh week to fifth month. . Fifth to ninth month Ninth to twelfth month Milk according to the above formulae can be ver}' simply prepared by the aid of a spe- cially made graduate known as the "Materna" and shown in Fig. 49. PREPARED MILK FOODS. Milk Powder. — There are numerous brands of desiccated milk or milk powder on the market, sold in bulk and by the can, and largely used by bakers and manufacturers of milk chocolate. Many of these, purporting to con- tain all the ingredients of milk excepting water, have been found by the author to be pulverized dried skimmed milk. The following are analyses of whole milk, half-skim milk, and skim milk powders : Whole Milk, Powder.* Moisture 3.62 Fat 26.75 Proteins (NX 6.25) 32.06 Milk sugar 3 1 - 90 Ash 5.67 Fig. 49. — The "Materna" Graduate for Modifying Milk. 100.00 Half-skim Milk, Skim Milk, Powder.* Powder. t 5.01 8.16 15.26 1-73 38-39 33-84 34-67 49-35 6.67 6.87 100.00 99-95 The fat in the skim milk powder corresponds to about 0.16% fat in the original milk. Jensen J states that the casein of dried milk no longer has the power * C. Huyge, Rev. gen. du Lait, 3, 1904, p. 400. t Analysis by the author. I Molkerei Ztg., Berlin, 15, 1905, p. 565. 158 FOOD INSPECTION AND ANALYSIS. of swelling when mixed with water. To obviate this difficulty, Hatmaker adds to the milk i to 3% of sodium bicarbonate, and Elkenberg 2% of cane-sugar. A Swiss milk powder examined by Jensen contained an excess of sodium and a low acidity, indicating the addition of an alkaline sodium salt. Artificial Albuminous Foods. — The albumin and casein of milk have furnished the basis of a variety of food preparations, some of which arc intended for the use of invalids and people of weak digestion, and others, from their compactness, for travellers and campers. Among these foods are the following: Niitrose. — This is a caseinate of sodium formed by the action of the alkali upon dried casein. It is soluble in water. Eucasin is a caseinate of ammonium, a soluble powder somevv^hat similar to nutrose. Plasmon. — This is a yellowish powder, prepared by treatment with sodium bicarbonate of the curd precipitated from skimmed milk. The compound is kneaded in an atmosphere of carbon dioxide, and reduced to a soluble powder. The following analysis of plasmon was made by Woods and Merrill : * Water. Proteids. Fat. Carbohydrates. Ash. Fuel Value. 8-5 75-0 0.2 8.9 7-4 2044 Sanose. — This is also a powder, containing 80% of pure casein and 20% of albumose, obtained from the white of egg. The powder possesses a slight taste and an odor suggestive of milk. By briskly stirring the powder with water, an emulsion may be made much resembling milk, but on standing it soon breaks up. Sanatogen is a grayish-white, tasteless powder, containing 95% of casein and 5% sodium glycero-phosphate. When treated with cold water it swells, forming on heating a milk-like emulsion. Koumis is a stimulating beverage, prepared by allowing milk to undergo alcoholic, lactic, and proteolytic fermentations. The original koumis was made by the Tartar tribes of Asia from mare's milk, which contains more lactose than cow's milk, and apparently lends itself more readily to fermentation. Only a hmited amount of koumis is now made from mare's milk, the milk chiefly used for this preparation being that of the cow, treated with yeast and sometimes added sugar. Koumis is a beverage much more commonly used in Europe than in America. ♦Maine Exp. Station, Bulletin 178, p. loi. MILK. 159 The following analyses were made by Vieth:* Water. Alco- hol. Fat. Casein. Albu- min. Albu- min- oses. Lactic Acid. Siigar. Ash. Mare's milk 92.07 90-57 92-52 2.98 1.04 0-57 1.30 0.83 1.38 1.88 0-33 2.03 0.24 0.20 0.07 0.77 0.77 0.63 1.27 1.40 0.56 0.23 2.18 2-45 0-35 0.58 0.84 Cow's milk Skimmed milk Kephir. — This is a fermented milk product similar to koumis, excepting that the fermentation is induced by a fungus known as kephir grains. The proteolytic fermentation is less pronounced in kephir than in koumis. Konig gives the following table as the mean of twenty-eight analyses: Water, j N,^- Casein. 1 ^n. 1 Albu- min. Hemi- Pep- p . albumin, tone. 1 Lac- j Lactic tose. 1 Acid. Alco- hol. Ash. 91.21 3.49 2-53 0.36 0.21 0.21 0.039 1.44 2.41 1.02 0-75 0.68 ADULTERATION OF MILK. Systems of Milk Inspection. — A typical method of general food inspec- tion has already been outUned (see pp. 6 and 8), which may easily be modi- fied to include the inspection of milk in connection with other foods, or to provide for a system of milk inspection exclusively. In the examination of such a perishable food as milk, it has not been found practicable for the analyst to reserve for the benefit of the defendant a sealed sample, as in the case of other foods, but experience has shown it had best be made the duty of the collector or inspector to give a sealed sample of milk to the dealer, when the latter requests it at the time of taking the sample. For this purpose the collector is provided with small bottles and sealing pharaphernalia, in addition to the tagged sample bottles or cans in which he collects the milk. The collector should use the same precautions for obtaining a perfectly fair representative sample as does the chemist in making the analysis, i.e., he should carefully pour the milk from the original container into an empty can or vessel and back again, before taking his sample. Each sample is properly numbered by the collector in presence of the dealer, and the data as to the taking of the sample entered at once under the proper number in the collector's book. If a sealed sample is given, * Richmond Dairy Chemistry, p. 241 et seq. l6o FOOD INSPECTION AND ANALYSIS. it should bear the same number as the sample reserved for analysis, and a receipt should invariably be required from the dealer, as evidence that his request for a sealed sample has been complied with. Milk Standards Fixed by Law. — In localities where a systematic form of milk inspection prevails, there is usually in force a statute fixing the legal standard for the total solids, and in many cases for the fat or for the sohds exclusive of fat. In some states the statute is so drawn that any deviation from the legal standard constitutes an adulteration in the eye of the law, and hence the offender, who has such milk in his possession with intent to sell, is liable to the same fine as if he actually added water or a foreign substance to the milk. In other states a distinction is made by the statute between milk that is simply below the legal standard of total solids, and milk containing actually added ingredients (water or otherwise), a much hghter fine being imposed for the former than for the latter offense. "Where such a dis- tinction prevails, it often becomes incumbent upon the analyst to show to the satisfaction of the court, in case of milk low in solids, whether or not the milk has been fraudulently watered after being drawn from the cow, it being well understood that cows may give milk below the standard. Pure milk that is low in solids may owe its deficiency either to poor feeding, or to an inherent tendency on the part of the cow to give milk always of poor quality. Thus the Holstein cow, more than any other breed, is open to the charge of sometimes giving milk below the standard.* That the Holstein cow is a favorite with the producer is by no means strange, from the fact that no other breed can with moderate feeding be made to give so large a quantity of milk. Wherever there is a statute fixing the standard for milk, it commonly provides also that the addition of any foreign substance whatsoever con- stitutes an adulteration. U. S. Standards.! — Standard milk is the fresh, clean, lacteal secre- tion obtained by the complete milking of one or more perfectly healthy * This statement should not be taken as condemning the Holstein, for it is true that cows of this breed often give milk far above the standard. A large number of samples of milk of known purity from Holsteins analyzed by the writer have been found to be of excellent quality. It is a curious fact that among the samples of known purity analyzed by the Massa- chusetts Board of Health, both the lowest and highest total solids on record came from a Holstein cow; the lowest recorded total solids in a "known purity" milk being 9.96 per cent, (seventh annual report of Massachusetts State Board of Health, Lunacy, and Charity, p. 160), and the highest being 17.06 per cent, (twenty-second annual report of the Massa- chusetts State Board of Health, p. 405). tU. S. Dept. of Agric, Off. of Sec, Circ. 19. MILK. i6r cows, properly fed and kept, excluding that obtained within fifteen days before and ten days after calving, and contains not less than 8.5% of solids not fat, nor less than 3.25% of milk-fat. Standard Skim-milk is skim-milk containing not less than 9.25% of milk solids. Forms of Adulteration.— Milk is ordinarily adulterated (i) by watering, (2) by skimming, (3) by both watering and skimming, and (4) by the addition of one or more foreign ingredients. Watering and Skimming. — The fact that milk is found below the standard of total solids, while more often due to an excess of water, may also be due to a deficiency in fat. In one case the milk is commonly termed watered, and in the other skimmed, using the terms broadly and not necessarily meaning actual and fraudulent tampering with the milk. In a third case, and almost invariably fraudulently, both watering and skimming may be found to have been practiced on the same sample. The analyst judges which of these causes have produced a milk low in sohds, by a careful study of the relation between the percentages of total sohds, fat, and solids not fat. If both the total sohds and solids not fat are abnormally low, and the proportion of fat to solids not fat about the same as, or higher than> in a normal milk, it is generally safe to assume that the sample has been watered; if both the total sohds and the fat are well below the standard, and the solids not fat nearly normal, then the milk has undoubtedly been skimmed; if, in the third place, the total solids and the solids not fat are proportionally reduced below the standard, while the ratio of fat to solids not fat is abnormally small, it is safe to adjudge the milk to be low by reason of both skimming and watering. Milk of Known Purity. — It is difficult to place the minimum figure for total solids, below which a milk sample may safely be pronounced by the analyst as fraudulently watered after having been drawn from the cow. Nearly nine hundred sr.mples of milk of known purity from various breeds of cow, milked in the presence of an inspector, have been analyzed in the Department of Food and Drug Inspection of the Massa- chusetts State Board of Health, extending over a period of fifteen years, and among these are many samples from Holstein cows. It is extremely rare that any of these known purity samples have been found with total solids as low as 11%, though there are instances where total solids have run as low as 10%. 1 62 FOOD INSPECTION AND AN /I LYSIS. It is safe to assume that in the few cases on record showing less than 10.75% of total solids, either there was something decidedly abnormal about the health of the cow, or, through some accident, the cow was only partially milked, it being a well-known fact tnat the last fraction of the milking includes the larger percentage of fat. (See page 128.) It is therefore nearly always safe to condemn a milk standing below 10.75 ^s fraudulently watered, if at the same time it has a proportionately high per cent of fat. The average total solids of 800 samples of milk of known purity analyzed by the Massachusetts Board up to and including the year 1890 amounted to about i3i%. It is rare indeed to find a herd of ten or more well-fed cows of mixed breeds in which the average milk of the herd falls below i2j% of solids. The milk of forty-seven Holstein cows, examined in 1885, was found to contain an average of 12.51% of total solids, while the milk of eleven Jerseys examined in the same year averaged 14.02% of solids. These examples represent the two extremes commonly met with. Variation in Standard. — In Massachusetts the law fixes a different standard for total solids in milk during the summer, or pasture-fed season, from that in force during the winter, or stall-fed period. From April to September inclusive the legal standard is 12% of total solids, of which 9% are solids not fat, and from October to March inclusive it is 13%, of which 9.3% are solids not fat. Bearing on the cpestion of difference in normal quality of milk during the two periods, averages were taken of the milks collected by the corps of inspectors of the Massachusetts Board of Health during a month in each period, December and June being selected as most typical, and during these months all the samples were analyzed both for total solids and fat. The samples were taken from stores, milkmen, and producers, and represented as nearly as possible the milk as actually sold to the consumers. In making the averages, all samples of skimmed milk, as well as all sJimples standing above 17% of total solids, or under 10.75%^, were deducted. The results are summarized as follows: MILK. 163 QUALITY OF MILK SOLD IX MASSACHUSETTS CITIES AND TOWNS IN WINTER AND SUMMER. December. Number of Samples. Total Solids. Fat. Solids not Fat. Average Per Cent, Highest Per Cent. Lowest Per Cent. Average Per Cent. Highest Per Cent. Lowest Per Cent. Average Per Cent. Cities Towns Summary. ,. . 403 99 502 16.86 1^.48 16.86 10.88 12.02 10.88 13.21 13-44 13-32 8.50 6.65 S.50 2.40 3-50 2.40 4.37 4.4S 4.42 S.74 8. 96 8. 85 June. Number of Samples. Total Solids. Fat. SoUds not Fat. Average Per Cent, Highest Per Cent. Lowest Per Cent. Average Per Cent. Highest Per Cent. Lowest Per Cent. Average Per Cent. Cities Towns Summary .... 3" 76 387 16.90 15.71 16.90 10-75 10.99 IO-75 12.67 12.63 12.65 8.80 7.10 8.80 2.10 3.00 2.10 4-03 4.09 4.06 8-54 8.54. 8.54 It is interesting to note that the average for total solids of the 88g samples e.xamined for both months stands at just 13%, of which 4.24% is fat and 8.76 is solids not fat. Rapid Approximate Methods of Determining the Quality of Milk. — The Lactometer. — A rough idea of the quality of milk can be gained by the use of the lactometer (page 131), but, in view of the fact that a low specific gravity may be the result either of a watered milk or of a milk high in fat, good judgment is necessary in connection with its use. A milk of good standard quality should have a specific gravity betvv'een the limits of 1.027 and I •033. A watered milk would run below the former and a skimmed milk above the latter figure, though a milk unusually rich in fat would also run low. It should easily be apparent from the taste and appear- ance of the milk, whether a low specific gravity is due to watering or unusual richness in fat. The fact should also be recognized, that a milk sample may be far below the standard, and still show a specific gravity within the limits of pure milk, by skillfully subjecting the milk to both skimming and watering. The Lactoscope. — Feser's lactoscope (Fig. 50) gives an approximation to the amount of fat in milk, and its use, especially in connection with the lactometer, is of some value. This instrument consists of a graduated glass barrel, a, into the bottom of which is accurately fitted the stopper, bearing 164 FOOD INSPECTION AND /iN A LYSIS. a white glass cylinder, having black lines thereon. Four cc. of milk are introduced into the barrel by means of a pipette, c, and water is added with thorough mixing till the translucence of the mixture is sufficient to allow the black lines to be perceptible through it. The height of the level of milk and water in the barrel a is then read off, the number indicating roughly the percentage of fat in the sample. As in the case of the lactometer, the purity of a milk sample cannot be positively established by the lactoscope alone. For instance, a watered milk abnormally high in fat would often be found to read within the limits of pure milk, when as a matter of fact its total solids would be below stand- ard. By a careful comparison of the readings of both the lactoscope and lactometer, however, it is rare that a skimmed or watered sample could escape detection. Thus, if the specific gravity by the lactometer is well within the limits of pure milk, and the fat, as shown by the lactoscope, is above 3^ per cent., the sample may be safely passed as pure, or as conforming to the standard. A normal lactometer reading in connection with an abnormally low lactoscope reading shows both watering and skimming, and with an abnormally high lactoscope reading shows a milk high in fat, or a cream. With the lactoscope reading below three, and a ..low lactometer reading, watering is indicated. A lactometer reading above thirty-three, and a low lactoscope reading, indicate skimming, Heereti's Pioscope. — This instrument consists of a hard-rubber disk, having in the center a shallow receptacle, the circular rim of which is raised above the level of the disk. Into this receptacle are introduced a few drops of the milk to be tested, and a circular cover-glass containing a number of variously tinted segments is placed over the receptacle, which spreads the milk out into a thin layer, and causes it to assume a tint against the black background that can be matched with one of the colors on the glass, the various tints indicating milks of various grades from the very poorest to rich cream. This test is at best a very rough one. Examination of the Milk Serum. — Detection of Added Water. — This may often be detected by determining the specific gravity or the degree of refraction of the milk serum, since it has been found that under fixed conditions the composition of the milk serum, or clear " whey,'' is more constant than that of the milk itself. Hence any considerable amount of watering is manifest from the physical constants of the serum. In using this method the analyst should carefully work out his own MILK. 1^5 standards for comparison, by personal experiment on milk of known composition to which varying amounts of water have been added, using ■3)^1 ^^^^JJ Fig. so. — Feser's Lactoscope. the same conditions for obtaining the serum in all cases. Woodman's method * is as follows: To loo cc. of the milk at a temperature of about 20° C. are added 2 cc. of 25% acetic acid, specific gravity 1.0350, in a * Jour. Am. Chem. Soc, 2i, 1899, p. 503. 1 66 FOOD INSPECTION AND /IN A LYSIS. beaker, and the beaker, covered with a watch-glass, is heated in a water- bath for 20 minutes at a temperature of 70° C. After this the beaker is placed in ice water for 10 minutes and the solution filtered. Specific Gravity. — The specific gravity of the clear filtrate, obtained by the method described above, is taken at 15° C. with the Westphal balance. Immersion Refractometer Reading, — The instrument used is the Zeiss immersion or dipping refractometer described on pages in to 121. The serum, prepared as directed in a preceding paragraph, is examined in one of the small beakers accompanying the apparatus at a temperature of 20° C. Constants of the Serum. — The three tables which follow show the variation of specific gravity and immersion refractometer reading on milk of different composition. Analyses of whole milk submitted by the author to varying degrees of watering, up to 50% of added water, are given in the following table : CONSTANTS OF MILK AND MILK SERUM. A WHOLE MILK SYSTEMATICALLY WATERED. Determinations or Milk. On Milk Serum. Added Water, Per Cent. Total SoHds, Per Cent. Water, Per Cent. Fat, Per Cent. Solids not Fat, Per Cent. Ash, Per Cent. Specific Gravity at 1 5° C. Specific Gravity at 1 5° C. Immersioa Refrac- tometer Reading at 20° C. 10 12.65 87-35 88.67 4.00 3-5° 8.65 7-83 0.65 0.60 1-0315 1.0278 1.0287 I .0260 42.40 39-75 20 10.10 89.90 3.10 7.00 0-53 1.0252 1.0230 36.90 30 8-95 91.05 2.80 6.15 0.48 I. 02 I I 1.0200 34.10 40 7.67 92-33 2.40 5-27 0.40 I. 0192 I. 0167 31.10 5° 6.43 93-57 2.00 4-43 0.38 I. 0154 I. 0140 28.45 The first table on p. 167 shows a centrifugally skimmed milk, sy.stemat- ically watered up to 50% of added water, as in the preceding table. It will be observed that both the specific gravity and immersion refractom- eter readings of the serum of the whole milk, agree very closely with those of the skimmed milk in cases having a corresponding amount of added water. The second table on p. 167 shows analyses of milk selected from a wide range of samples regularly collected and examined in the routine of food inspection by the Massachusetts State Board of Health. MILK. 167 CONSTANTS OF MILK AND MILK SERUM. A SKIMMED MILK SYSTEMATICALLY WATERED. Determinations on Milk. On Milk Serum. Added Water, Per Cent. Total Solids, Per Cent. Water, Per Cent. Fat. Per Cent. Solids not Fat, Per Cent. Ash, Per Cent. Specific Gravity at 15° C. Specific Gravity at 1 5° C. Immersion Refrac- tometer Reading at 20° C. 10 9-05 8.14 90-95 91.85 0.03 0.03 9.02 8. II 0.64 0.60 1-0350 I. -0317 I .0296 I .0260 42.85 39.60 20 7.27 92-73 0.02 7-25 0.56 1.0278 1.0230 36-85 30 6.41 93 - 59 0.02 6-39 0.48 1.0247 I .0200 34.00 40 5-5° 94-50 O.OI 5-49 0.44 1.0209 I. 01 70 31.20 50 4.61 95-39 O.OI 4.60 0.39 I. 0172 I. 0140 28.50 CONSTANTS OF MILK AND MILK SERUM. LABORATORY SAMPLES Determinations on Milk On Milk Serum. Total SoUds, Water, Fat, Solids not Fat, Ash, Specific Gravity at 15° C. Specific Gravity at 15° C. Immersion Refractom- Per Cent. Per Cent. Per Cent. Per Cent. Per Cent. eter Read- ing at 20° C. 16.45 15.90 S^.trc 8.20 8.2? I . n->cc 1.0274 1.0285 40.95 42.00 84 10 7 00 8 90 0.69 0277 14-37 85 63 5 50 8 88 0.58 0282 1.0280 42.40 14.17 85 83 4 85 9 32 0.62 0313 I. 0281 44.20 14.04 85 96 4 95 9 09 0.60 0303 1.0274 42.70 13.80 86 20 5 00 8 80 0.65 0302 1.0289 42.7s 13-59 86 41 4 30 9 29 0.64 0321 1.0285 44-50 13-39 86 61 4 40 8 99 0.50 0324 1.0285 43-7° 13.28 86 72 4 40 8 88 0.60 0299 1.0289 42.65 13.12 86 88 4 00 9 12 0-59 0317 1.0280 43-75 13.00 87 00 4 30 8 70 0.56 0310 1.0266 42.60 12.90 87 10 3 85 9 05 0.61 0318 1.0289 43-40 12.80 87 20 4 30 8 50 0.46 0304 1.0277 42.70 12.70 87 30 3 80 8 90 0.53 0314 1.0280 43.10 12.63 87 37 3 50 9 13 0.65 0323 1.0277 43-65 12.62 87 38 4 10 8 52 0.52 0298 1.0272 42.40 12.57 87 43 3 70 8 87 0.68 0317 1.0278 43-45 12.47 87 53 3 60 8 87 0.65 0303 1.0282 43-15 12.36 87 64 3 20 9 16 0-55 0327 1.0282 43-25 12.30 87 70 3 20 9 10 0.62 0327 1.0283 44.00 12. 16 87 84 4 35 7 81 0.49 0275 I 0265 41. 10 12.00 88 00 3 40 8 60 0.62 0275 1.0280 41-75 11.86 88 14 3 60 8 26 0.49 0306 1.0266 42.40 11.67 88 2,2, 3 95 7 77 0.48 0265 1.0240 39-30 II .60 88 40 2 75 8 85 0.65 0320 1.0282 43-55 11.50 88 50 3 45 8 05 0.51 0290 1.0269 41.40 11.40 88 60 3 10 8 30 0.60 0297 1.0278 42.00 11.25 88 75 2 80 8 45 0.58 0280 1.0274 40.90 11.07 88 93 3 00 8 07 0.62 0290 I .0270 40.75 10.69 89 31 2 95 20 7 6 74 95 0288 I .0262 39-85 36.40 10.25 89 75 3 0-55 0230 1.0223 8.34 91.66 2 .20 6 14 0.38 0224 1.0207 34.70 1 68 FOOD INSPECTION AND ANALYSIS. A comparison of the immersion refractometer readings of the serum of milk of varying quality shows at once that the refraction of the serum is a general index to watering. A reading below 40 with the above conditions carefully observed would be suspicious of added water, though 39 might more safely be placed as a limit, below which milk could be declared fraudulendy watered. The analyst need not hesitate in testify- ing to the presence of added water, when the refraction is lower than 39 under the above conditions and the solids not fat below 7.3%. The tables on page 169 give a summary of refractometric and analytical results of a large number of milk samples from three widely separated localities, namely, Massachusetts, New Jersey, and Great Britain: Nitrates. — Pure milk, free from contamination with stable filth, con- tains no nitrates; well water, however, often contains a suflficient amount to enable the detection of a 10% admixture in milk. The diphenylamin test, first employed by Soxhlet to detect nitrates in milk, has since been modified by Moslinger,* Richmond, f Hefel- mann,| Reisz,§ Patrick, and others.]} Place in a small porcelain crucible one cc. of a solution of o.i gram of diphenylamin in 1000 cc. of concentrated sulphuric acid and allow a few drops of the milk serum to flow over the surface. A blue color appearing within 10 minutes indicates the presence of nitrates. On longer standing, a brown color forms, whether or not nitrates are present. The delicacy of the test is increased by adding to the reagent a small amount of powdered sodium chloride shortly before using. Systematic Examination of Milk for Adulteration.— If a large number of samples of milk have to be examined daily for adul- teration, it may be an advantage to submit all to a preliminary test with the lactoscope and lactometer, excluding from further analysis, as above the standard, such samples as pass certain prescribed limits which experi- ence has proved these tests to be capable of showing to an experienced observer, and submitting the remainder to a chemical analysis. In using such an instrument as the lactoscope for this purpose, the individual element is a most important consideration, and the use of this instrum_ent * Ber. uber die 7 Versammlung bayerischer Chemiker. Berlin, 1889. t Analyst, 18, 1893, p. 272. X Zeits. offentl. Chem., 7, 1901, p. 200. § Pharm. Zeit., 49, 1904, p. 608. 11 See Tillmans: Zeits. Unters. Nahr. (ienuss., 20, 1910, p. 676. MILK. 169 •0 c _a ■m c W "o a > JO UOI}3BJJ3-}J p> OP<"^"^OOOcoOO \C>0 Mvovoo mOO POM r)-o coo coom Tj-'^'^'^-^'t'^CO'*-* •}BJ JOU SpiJOg C l^sO 00 "^ '^ PI coo PI •* "* OoO '^1- covO ^ CO OCO CM^ OS t^OO t^ luao ja£ '}B^ 8 ,, Tj-vO 00 ■* -^vC \0 00 M PI PI \0 1000 CO cjoO M •5 VO ^lOcO'S-PI loPI PI PI jaj 'spijos iBjox CI t^OCO CO PI lOt^OOO CO OOOOvOChOOMOsPi ■^-^cocopipImmOO •sa|d -uiBg }o jaquinpij M ^_^_,,_^_^, ,.__^^^__^^ 00 CO t^ M CO r^ uo '' ' ' ' c 'So >. "o >, a! c .Q rt iJ u H >, (p i2 * •}BjI JOU 'spijos OCO OCO CO CO 00 ■iU33 Jaj 'IBJ m "^ 00 CO N PI w 00 VO »0 VTi 1- -tf CO CO CO ■juao ja^ 'spHos F?ox PI 1-1 w ^O PI vO •* t^ PI M "* t^ ■^ Tt CO CO PI MM sajd -uiBg JO jaquin(.j ^ ■2 PI M PI ' ■5 "a Hi "2 pa 1 .C '3o°^ jBuinaag JO uoijoBJja'^ >0 ^ Tt- M OsCO CO -* M rf On M On -t -t Tj- -f CO ^ CO •}Bj 50U spHOg ■+ 00 Ov CO '^O CO On CO M Tt -^ On TT On Onoo 00 t^ r^ t^ •JUaO J3cl 'JB^ vo 10 10 10 CO 10 irjvo NO ■* in ^ "^f CO CO PI CO PI •juao J3(J 'spHOg IBJOX •+ M M CO M CO COOO -i- Ov M Ov CO CO PI PI M M 0" ■sajd -uiBg JO jaquinM N M CO PI 00 M PI 0) -1 ^ S_g S^ S_^ £_^ bOgbJOgbiDgbCgbO u -1 '--—^^'-^^—^'—^-^'—^ Classification according to Total Solids, Per cent. 1) > < M M i .a- CO PI M C CO PI M C c - ■^ NO NO U-) CO t^oO ^ On PI CO On 00 to ~- •^t- CO Tf ^ CO CO CO a c f5 OJ •a >> aj tn ^ "^ c: M m i^ u *J I, Moo CI NO CO On CO CI CO p On r^oo On r-~ t^NO CO. o tfl cfl . c r- iJ^ cj d J cs nC " CO ? 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SO s-^s Z^6^^ 7 .^R2.3 n.GS Z^.VG (f . 630/ iX.foO 1(,6-S 9 .G9Z^ /3.9J' 2.h(^0 JO .6fS6- J2.Z7 XhbZ II .■'.5-96' 9.19 s 0.1 S 9.0*i Xbb^ IX ^693 9.39 6 0.86' 6.^^ l^U ;3 65-30 I3.GL XUS i"^ fJ^fZ Zii.90 2^7^ n' ^793 IJ..X9 Z(.7Z 1^ 7393 }^19 JVvt/L Ci(>7^ n .7/00. y-^.:?/) 3^76 /^ GOlO )Z.02 1Q7^ )"! . ^.^ro f 9.00 7 I.ZO 7 .80 Ib^O 10 . 66-31 J3.0G ' ' Specimen Card for Analyst's Records of Milk Analyses. To be filed in a cabinet. MILK. 173 before, the exact net weight of the residue is at once ascertained and entered in the appropriate column in the note-book. IVIultiplied by 20 it gives at once the percentage of total soUds. It is a great saving of time to weigh out exactly 5 grams as above described. The knack of quickly measuring out the exact amount is easily acquired with practice, the 5-gram weight is the only one required for the operation with the counterweight of the dish, and the laborious figuring of percentage due to using a fraction above or below the 5 grams of milk is avoided. Such samples as are found to stand below the standard of total solids are further examined for fat by the Babcock process (p, 136), entering the number of the fat bottle in the note-book in the appropriate column, and subsequently the percentage of fat. Ordinarily the specific gravity is not determined, excepting in some cases of badly watered milk, when, for purposes of a check, it is customary to take the specific gravity, and calculate the solids from the gravity and the fat by Babcock's formula (p. 153), or the Richmond sHding scale, and compare the result with the figure directly determined. The ash is rarely weighed except in special cases. The dishes containing the drv' residues are easily cleaned by first burning to an ash and cooling, after which they are treated successively with strong nitric acid, which is poured from one to another, the dishes being rinsed thoroughly with water and finally heated to redness. A convenient device for ashing a large number of residues for purposes of cleaning the platinum dishes and for final heating is the incinerator shown in Fig. 52, made of Russia iron. Fig. 52. A Sheet-metal Incinerator, Specially Used for Ashing Milk Residue. Added Foreign ingredients. — "Passing over such mythical adulterants as chalk and such rarely used substances as calves' brains, starch, glycerm, sugar, etc., often discussed in manuals on milk, but 174 FOOD INSPECTION AND ANALYSIS. with few authentic instances of their actual occurrence, the commonly found adulterants may be divided into two classes : coloring matters and preservatives. The coloring matters almost exclusively used are annatto, azo-colors, and caramel. The preservatives commonly met with are formaldehyde, boric acid, borax, and sodium bicarbonate. Rarely salicylic and benzoic acids are found. Coloring Matters. — While it is more often true that an artificially colored milk is also found to be watered, the coloring being added to cover up evidence of the watering, it is not uncommon to find added coloring matter in milk above the standard.* About 95% of the milks found colored in Massachusetts show on analysis the fraudulent addition of water. Statistics of the Massachusetts State Board of Health show that out of 48,000 samples of milk collected throughout the state and analyzed during nine years (from 1894 to 1902 inclusive) 342 samples or 0.7% were found to contain foreign coloring matter. Of these samples, about 67% contained annatto, approximately 30% were found with an azo- dye, and about 3% with caramel. Until comparatively recently annatto was employed almost exclu- sively for this purpose. Caramel is least desirable of all the above colors from the point of view of the milk-dealer, in that it is difficult to imitate with it the natural color of milk, by reason of the fact that the caramel color has too much of the brown and too little of the yellow in its com- position. Annatto, on the other hand, when judiciously used and with the right dilution, gives a very rich, creamy appearance to the milk, even when watered, which accounts for its popularity as a milk adulterant. Of late, however, the use of one or more of the azo-dyes has been on the increase, and so far as a close imitation of the cream color is con- cerned, these colors are quite as efficient as annatto. Appearance of Artificially Colored Milk. — The natural yellow color of milk confines itself largely to the cream. An artificial color, on the contrary, is dissipated through the whole body of the milk, so that when the cream has risen in a milk thus colored, the underlying layers, instead of showing the familiar bluish tint of skimmed milk, are still distinctly tinged below the layer of the fat, especially if any considerable quantity of the color has been used. This distinctive appearance is in itself often * In one instance an azo-dye was found by the writer in a milk that contained over 17% of total solids. MILK. 175 sufficient to direct the attention of the analyst to an artificially colored milk, in the course of handling a large number of samples. Nature of Annatto. — Annatto, arnatto, or annotto is a reddish-yellow coloring m.attcr, derived from the pulp inclosing the seeds of the Bixa orellana, a shrub indigenous to South America and the West Indies. A solution of the coloring matter in weak alkali is the form usually employed in milk. Nature of "Anilin Orange." — Of the coal-tar colors employed for coloring milk, the azo-dyes are best adapted for this purpose and arc most used. A few samples of these commercial "milk improvers" have fallen into the hands of the Department of Food and Drug Inspection of the Massachusetts Board of Health, and have JDroved, on examination, to be mixtures of two or more members of the diazo-compounds of anilin. A mixture of what is known to the trade as "Orange G" and "Fast Yel- low" gives a color which is practically identical with one of these prep- arations, secured from a milk-dealer and formerly used by him. For purposes of prosecution or otherwise, it is obviously best in our present knov.-ledge of the subject to adopt a generic name such as "a coal-tar dye" or "anilin orange"* to designate this class of coloring matters in milk, rather than to particularize. Systematic Examination of Milk for Color. — The general scheme employed by the writer for the examination of milk samples suspected of being colored is as follows if About 150 cc. of the milk are curdled by the aid of heat and acetic acid, preferably in a porcelain casserole over a Bunsen flame. By the aid of a stirring-rod, the curd can nearly always be gathered into one mass, which is much the easiest method of separa- tion, the whey being simply poured off. If, however, the curd is too finely divided in the whey, the separation is effected by straining through a sieve or colander. All of the annatto, or of the coal-tar dye present in the milk treated would be found in the curd, and part of the caramel. The curd, pressed free from adhering liquid, is picked apart, if necessary, and shaken with ether in a corked iiask, in which it is allowed to soak for several hours, or until the fat has been extracted, and with it the annatto. If the milk is uncolored, or has been colored with annatto, on pouring off the ether the curd should be left perfectly white. If, on * The term "anilin orange" has been so commonly applied during the last eight years to any color or mixture of colors of this class in complaints in the Massachusetts courts, as -to have acejuircd a special meaning perfectly well understood. t Jour. Am. Chem. Soc, 22, 1900, p. 207. 176 FOOD INSPECTION AND ANALYSIS. the Other hand, aniHn orange or caramel has been used, after pouring off the ether the curd will be colored more or less deeply, depending on the amount of color employed. In other words, of the three colors, annatto, caramel, and anilin orange, the annatto only is extracted by ether. If caramel has been used, the curd will have a brown color at this stage; if anilin orange, the color of the curd will be a more or less bright orange. Tests for Annatto.— The ether extract, containing the fat and the annatto, if present, is evaporated on the water-bath, the residue is made alkaline with sodium hydroxide, and poured upon a small, wet filter, which will hold back the fat, and, as the filtrate passes through, will allow the annatto, if present, to permeate the pores of the filter. On washing off the fat gently under the water-tap, all the annatto of the milk used for the test will be found to have been concentrated on the filter, giving it an orange color, tolerably permanent and varying in depth with the amount of annatto present. As a confirmatory test for annatto, stan- nous chloride may afterward be applied to the colored filter, producing the characteristic pink color. Tests for Caramel. — The fat-freed curd, if colored after the ether has been poured off, is examined further for caramel or anihn orange, by placing a portion of the curd in a test-tube,, and shaking vigorously with concentrated hydrochloric acid. If the color is caramel, the acid solution of the colored curd will gradually turn a deep blue on shaking, as would also the white fat-free curd of an uncolored milk, the blue colora- tion being formed in a very few minutes, if the fat has been thoroughly extracted from the curd; indeed, it seems to be absolutely essential for the prompt formation of the blue color in the acid solution that the curd be free from fat. Gentle heat will hasten the reaction. It should be noted that it is only when the blue coloration of the acid occurs in connection with a colored curd that caramel is to be suspected, and if much caramel be present , the coloration of the acid solution will be a brownish blue. If the above treatment indicates caramel, it would be well to confirm its presence, by testing a separate portion of the milk in the following manner.* About a gill of the milk is curdled by adding to it as much strong alcohol. The whey is filtered off, and a small quantity of subacctate of lead is added to it. The precipitate thus produced is collected ui'On a small filter, which is then dried in a place free from hydrogen sulphide. A pure milk thus treated yields upon the filter-paper a residue which is * See Nineteenth Annual Report of the Mass. State Board of Health (1887), p. 183. MILK. 177 either wholly white, or at most of a pale straw color, while in the presence of caramel, the residue is a more or less dark-brown color, according to the amount of caramel used. Tests for Coal-tar Dye. — If the milk has been colored with an azo-dye, the colored curd, on applying the strong hydrochloric acid in the test-tube, will immediately turn pink. If a large amount of the anilin dye has been used in the milk, the curd will sometimes show the pink coloration when hydrochloric acid is applied directly to it, before treatment with ether, but the color reaction with the fat-free curd is very delicate and unmistak- able.* Lythgoe'\ has shown that the amount of anilin orange ordinarily present in a milk for the purposes of coloring can be detected by adding directly, to say 10 cc. of the sample an equal quantity of strong hydro- chloric acid and mixing, whereupon the pink coloration is produced, if the dye is present in more than minute traces. The test is more deli- cate if carried out in a white porcelain dish. It had best be used as a preliminar}^ test only, and confirmed by a subsequent test on the fat-free curd as above. SUMMARY OF SCHEME FOR COLOR ANALYSIS. Curdle 150 cc. milk in casserole with heat and acetic acid. Gather curd in one mass. Pour off whey, or strain, if curd is finely divided. Macerate curd with ether in corked flask. Pour off ether. Ether Extract. Evaporate off ether, treat residue with NaOH and pour on wetted filter. After the solution has passed through, wash otT fat and dry filter, which if colored orange, indicates presence of annatto. (Confirm by SnCl,.) Extracted Curd. (i) 7/ Colorless. — Indicates presence of no foreign color other than in ether extract. (2) // Orange or Brownish. — Indicates presence of anilin orange or caramel. Shake curd in test-tube with concentrated hydrochloric acid. If solution gradu- ally turns blue, in- dicative of caramel. (Confirm by testing for caramel in whey of original milk.) If orange curd ifU' mediately turns pink, indicative of anilin orange. PRESERVATIVES. — In most States and municipalities where pure food laws are in force preservatives in milk are regarded as adulterants * Occasional samples of milk colored with a coal-tar dye of a different class from those already described have recently been found in Massachusetts. In these cases the color of the separated fat-free curd does not change when treated with hydrochloric acid. The color of the curd is, however, very marked, being deep orange, bordering on the pink. t Jour. Am. Chem. Soc, 22, 1900, p. 813. 1/8 FOOD INSPECTION AND ANALYSIS. Their use, however, seems to be on the decrease. Of 6,i86 samples of milk examined by the Massachusetts State Board of Health during one year (1899) 71 samples, or 1.2%, were found to contain a preservative. Of these 55 were found with formaldehyde, 13 containing boric acid, borax, or a mixture of the two, and 3 contained carbonate of soda. Comparative tests have been made in the writer's laboratory of the keeping quahties of these commonly used milk preservatives, when present in varying strength, the milk being kept during the experiment at the tem- perature of the room, which at that season of the year (February) was about 20° C* The preservatives were added about five hours after milking. The samples were titrated for acidity each morning, the acidity being expressed by the number of cubic centimeters of decinormal sodium hydroxide necessary to neutralize 5 cc. of the milk. The proportions of preservatives used in this experiment, as shown in the table on page 179, were intended to cover a wide range, from the weakest that could aid in preserving the milk up to a strength limited only by being perceptible to the taste. The table opposite shows the results. Formaldehyde, the most commonly used preservative for milk, is sold to the trade under various names, such as "Preservaline," "Freezine," "Ice- line," etc, all being dilute aqueous solutions of formaldehyde, containing from 2 to 6 per cent of the gas, being nearly always diluted from the 40% solution known as formalin. These preparations are usually accompanied by directions, which specify the amount to be used, varying from a table- spoonful of the solution in 5 to 10 gallons of the milk. It is commonly used in the strength of i part of the gas in 20,000, and rarely less than I part in 50,000. The antiseptic power of formaldehyde increases in a marked degree as the strength of the preservative is increased. Milk treated with i part in 10,000, for instance, according to the table was found to keep sweet 5^ days. In the strength of i part to 5000, the milk did not curdle for io| days, while i part of formaldehyde to 2500 parts of milk kept the milk from curdling for 55 days, the acidity up to that time being nearly normal. Formaldehyde is thus shown to be decidedly the most efficient of all m.ilk preservatives, besides being inexpensive and convenient to use. Whether the growth of other bacteria than those that produce lactic fermentation is inhibited by formaldehyde in milk is not definitely settled. The claim has been made that pathogenic varieties are destroyed by its use. * Thirty-first Annual Report Mass. State Board of Health, 1899, p. 611. MILK. 179 05 C O C o III I I U 111^ )-• N r* r^ O' w 0*00 •>t' S 1 1 1 1 1 1 1 1 1 1 I 1 I 0) >^ "d •0 1 1 II 1 II 1 1 II lllj '•3 1 III MM il II II n P D H ■d II 1 1 1 1 j3 II 111^ Q c is II 1 III "•d II 111" 01 P W ^1 X) II Mil CO -4-> ■3 M III" ClI Q 11 Ijll 10 •d II II §1 >. jd < <^ II II"? ■*0 ol P j| II III: ■-d II I r ? H I 'i C Xi U 0! H e- 'i c y. a u -d ^ *" •c m 5 1 '^ c ."2 "" ni • '- ■c fQ c c 1 h c c I So FOOD INSPECTION AND AN /t LYSIS. Whether or not formaldehyde in milk is harmful to processes of diges- tion, when present in the amount commonly used, is still an open question.* Carbonate and Bicarbonate of Soda.^ — These substances are occasion- ally used in milk, though, as the above table shows, they possess little or no value as milk preservatives. They do, however, serve to neutralize the acidity of slightly soured milk and to postpone the time of actual curdling. Salicylic and Benzoic Acids, in view of the much more efficient anti- septics at hand, are now rarely used as milk preservatives, though the analyst should be on the outlook for them. Salicylic acid is a poor milk preservative, in view of the fact that it affects the taste of the milk, when present in sufficient quantity, to be of service. Detection of Formaldehyde. — Hydrochloric Acid Test.-\ — Commercial hydrochloric acid (specific gravity 1.2) containing 2 cc. of 10% ferric chloride per liter is used as a reagent. Add 10 cc. of the acid reagent to an equal volume of milk in a porcelain casserole, and heat slowly over the free flame nearly to boiling, holding the casserole by the handle, and giving it a rotary motion while heating to break up the curd. The presence of formaldehyde is indicated by a violet coloration, varying in depth with the amount present. In the absence of formaldehyde, the solution slowly turns brown. By this test i part of formaldehyde in 250,000 parts of milk is readily detected before the milk sours. After souring, the limit of delicacy proves to be about i part in 50,000. Various aldehydes, when introduced into milk, give color reactions under the above treatment, but formaldehyde alone gives the violet colora- tion, which is perfectly distinguishable and unmistakable. Hehner's Sulphuric Acid Test. — To 5 to 10 cc. of milk in a wide test- tube add about half the volume of concentrated commercial sulphuric acid, I pouring the acid carefully down the side of the tube, so that it forms a layer at the bottom without mixing with the milk. A violet zone at * Milk-dealers are led to believe, by artful dealers in preservative preparations, that the chemist cannot detect them. The manufacturer of a widely used preservative, a weak solu- tion of formaldehyde, issues an attractive pamphlet in which he makes the following rem.ark- able claims: "It is not an adulterant. It immediately evaporates, so that no trace of it can be found as soon as it has rendered all the bacteria inert. No chemical analysis can prove its pres- ence in milk, quantitatively or otherwise." t Annual Report Mass. State Board of Health, 1897, p. 558; also 1899, p. 699. % The coloration produced seems to depend on the presence of iron salts in the acid, hence the use of commercial acid is recommended. If only pure acid is available, a little ferric chloride should be added MILK. . iSl the junction of the two hquids indicates formaldehyde. This test may be combined with the Babcock test for fat, noting whether a violet color forms on addition of the commercial sulphuric acid to the milk in the test bottle. Confirmatory Tests with Distilled Milk. — If it is desired to confirm the above tests by further evidence, loo to 200 cc. of the milk sample are subjected to distillation, and the first 20 cc. of the distillate are used for testing. (i) To a few drops of this distilb.te in a test-tube add a drop of Schiff's reagent.* In presence of any aldehyde, a pink coloration will soon be perceptible, deepening in intensity on standing. (2) Add to 5 cc. of the milk distillate a few drops of a 1% aqueous solution of resorcin or phenol, and proceed as directed on page 826 (pre- servatives). The crimson color indicates formaldehyde, and not other aldehydes. ' (3) Use I or 2 cc. of the milk distillate and apply the phenylhydrazine test, page 826. (4) A small amount of the distillate from milk (which prior to distilling is acidified slightly with sulphuric acid to fix any free ammonia) is treated with a few drops of Nessler's reagent. f Traces of formaldehyde produce a yellow coloration, while if considerable formaldehyde be present, the color darkens on standing and a grayish precipitate may be formed. Determination of Formaldehyde in Milk.t — To 100 cc. of milk add .1 cc. of 1:3 sulphuric acid and subject to distillation in a 500-cc. Kjeldahl nitrogen-flask, using a low circular evaporating burner to avoid frothing. According to Smith, the first 20 cc. of the distillate, or one-fifth the original volume, contain very nearly one-third of the total formaldehyde. Collect 20 cc. of the distillate and determine the formaldehyde therein by the potassium cyanide method, as follows :§ Treat 10 cc. of tenth-normal silver nitrate with 6 drops of 50% nitric acid m a 50-cc. flask, add 10 cc. of a solution of potassium cyanide con- taining 3.1 grams of KCN in 500 cc. of water, and m.ake up to the 50-cc. mark. Shake, filter, and titrate 25 cc. of the filtrate with tenth-normal ammonium sulphocyanate,|| using ferric chloride as an indicator. * Table of reagents, No. 226. t Table of reagents, No. 187. % Smith, Jour. Am. Chem. Soc, 25, 1903, pp. 1032 and 1037. § Zeits. anal. Chem., 36, pp. iS-24. (I Theoretically 7.6 grams per liter. On account of the deliquescent nature of the salt weigh out 8 grams, make up to a liter, and titrate against tenth-normal silver nitrate for its exact value, using ferric chloride as an indicator. Sutton, Volumetric Analysis, 8th Ed, P- 155- 1 82 FOOD INSPECTION /iND ANALYSIS. Acidify another portion of lo cc. of tenth-normal silver nitrate with nitric acid, add lo cc. of the potassium cyanide solution to which the above 20 cc. of the formaldehyde distillate has been added. Make up the whole to 50 cc, filter and titrate as before 25 cc. of the filtrate with tenth-normal ammonium sulphocyanate for the excess of silver. The amount of potassium cyanide used up by the formaldehyde, in terms of tenth-normal ammonium sulphocyanate, is found by multiplying by two the difference between the two results, and the total formal- dehyde is calculated by multiplying by 3 the amount found in the 20 cc. of distillate. The reaction that takes place between the formaldehyde and the potassium cyanide probably results in the formation of an addition product as follows: CH2O+ KCN = KO.CH2CN. Detection of Boric Acid. — This is best accomplished by the turmeric- paper test applied either directly to the milk or to the ash (page 823). In the former case 10 cc. of milk are thoroughly mixed with 6 drops of concentrated hydrochloric acid, after which the tumeric paper is mois- tened with the mixture and dried. Determination of Boric Acid. — Use the method of Thompson.* Add 10 cc. of a I : I solution of sodium hydroxide to 100 cc. of the milk, evaporate to dryness in a platinvim dish, and proceed as described on page 829. Detection of Carbonate and Bicarbonate of Soda. — The addition of carbonates is manifest by the effervescence caused by treating the milk-ash with acid. Effervescence in the milk-ash is quite perceptible, when as much as 0.05% of sodium carbonate is present. Schmidt's method of detecting sodium carbonate or bicarbonate, when present to the extent of 0.1% or more, is as follows: Ten cc. of milk are mixed with an equal volume of alcohol, and a few drops of a 1% solution of rosolic acid are added. If carbonate is present, a rose- red color will be produced, while pure milk shows a brownish-yellow coloration. The suspected sample thus treated should be compared with a similarly treated sample of pure milk at the same time. Detection of Benzoic Acid. — Shake 5 cc. of hydrochloric acid with 50 cc. of the milk in a flask. Then add 150 cc. of ether, cork the flask and shake well. Break up the emulsion which forms by the aid of a centrifuge, or, in the absence of a centrifuge, extract the curdled milk by gently shaking with successive portions of ether, avoiding the forma- * Jour. Soc. Chem. Ind., 12, p. 432. MILK. 183 tion of an emulsion. A volume of ether largely in excess over that of the curdled milk has been found to be less apt to emulsionize.* Transfer the ether extract to a separatory funnel, and separate the benzoic acid from the fat by shaking out with dilute ammonia, which takes out the former as ammonium benzoate. Evaporate the ammonia solution in a dish over the water-bath till all free ammonia has disappeared, but before getting to dryness, add a few drops of ferric chloride reagent. The characteristic flesh-colored precipitate indicates benzoic acid. Care should be taken not to add the ferric chloride till all the ammonia has been driven off, otherwise a precipitate of ferric hydrate is formed. Detection of Salicylic Acid. — (i) To 50 cc. of the milk add i cc. of acid nitrate of mercury reagent (p. 147), shake and filter. The filtrate, which should be perfectly clear, is then shaken with ether in a separatory funnel, the ether extract evaporated to dryness, and a drop of ferric chloride reagent applied. If salicylic acid be present, a violet color will be pro- duced. In carrying out the test it should be noted that a small portion only of the salicylic acid is in the filtered whey, the larger part being left in the curd. The color test is, however, so delicate as to show its presence, when an appreciable amount is used. (2) Proceed exactly as directed for benzoic add (p. 182). On apply- ing the ferric chloride to the final solution, after evaporation of the ammonia, a violet color shows the presence of saUcylic acid. Routine Inspection of Milk for Preservatives. — It was the writer's custom in Massachusetts to examine all the samples of milk collected during the months of June, July, August, and September for the com- monly used preservatives, in addition to the regular analysis for total solids and fat. The number of samples thus examined amounted to upwards of 500 per month, varying from 10 to 60 per day. The results of such an examination during four years are thus shown: f rHESKRVATIVES IN MILK. Year. Samples Examined. Number containing Form- aldehyde. Per Cent containing Form- aldehyde. Number containing Boric Acid. Per Cent containing Boric Acid. Number containing Carbonate. Total containing Preserva- tive. 1898 1046 210^ 2018 2154 1934 26 55 61 42 29 2-5 2.6 3-0 1.9 1-5 II 13 6 12 14 I.O 0.6 0-3 0-5 0.7 4 3 41 71 67 54 43 180Q 1000 igoi 1002 Totals. . . . 9257 213 2-3 56 1 0.6 7 376 * When this process is used the ether may readily be recovered by distillation, t An. Rep. Mass. State Board of Health, 1902, p. 474; Analyst's Reprint, p. 22. i84 FOOD INSPECTION ylND y4N/iLYSIS. Such a system by no means involves a large amount of time or labor, and is really essential before passing judgment upon the purity of the milk, since, unlike added color, there is nothing in the physical appear- ance of the milk to suggest the presence of preservatives, nor are they rendered apparent by the taste, if skilfully used. The methods employed are carried out as foUov^s : * (i) Formaldehyde. — After having been examined for total solids and fat, the milk samples are arranged in order in their original con- tainers, and about lo cc. of each sample are poured into a casserole and tested in succession by means of the hydrochloric acid and ferric chloride test (p. 1 80). A large stock bottle, which may be fitted with a siphon if desired, is kept on hand containing the hydrochloric acid reagent. Less than one minute is required in making the formaldehyde test for each sample. 2. Carbonate and Boric Acid. — These tests have been so simplified as to be, as it were, a side issue in the process of cleaning the platinum dishes used for the determination of total solids. The various residues from the total solids are burnt to an ash in the original numbered dishes in succession, these dishes, after incineration, being arranged side by side on a fiat tray. By means of a pipette, one or two drops of dilute hydro- chloric acid are introduced into each dish in succession, noting at the time any effervescence that may ensue, which is in itself an indication of sodium carbonate. After every milk ash has been acidulated, a few cubic centimeters of water are added to each dish by means of a wash- bottle, the dissolving of the ash being hastened by giving a rotary motion to the tray containing the dishes. A strip of turmeric-paper Is then allowed to soak for a minute or so in each dish, after which it is withdrawn from contact with the solution and allowed to adhere to the side of the dish above the liquid, where it remains until dry. If the paper when dry is of a deep cherr}^-red color, turning a dark olive when treated with dilute alkali, the presence of boric acid is assured. These methods are, of course, preliminary tests for quickly singling out the preserved samples. Such confirmatory tests as are desired may in all cases be employed. Another method of drying the strips outside the dishes is as follows: In a part of the laboratory free from dust, two long sections of glass rod or tubing are placed in parallel lines over a strip of filter-paper, * Leach, Analyst, XXVI, p. 289. An. Rep. Mass. State Board of Health, 1901, p. 447 Food and Drug Reprint, p. 27. MILK. 185 with numbers marked on the paper at close intervals corresponding to the numbers of the platinum dishes. The strips of turmeric-paper, after soaking, are removed from the dishes and placed across the glass tubes, over the numbers corresponding to those of the dishes from which they were taken. Here they arc allowed to stand till dry, being kept in posi- tion by a third section of tube or rod placed over them. Wlien dry, the color of the turmeric strips will indicate whether or not boric acid is present, and also the position will show in what sample to look for it. VARIOUS ADULTERANTS- — Cane Sugar is said to be used to increase the total soUds of milk, but if present to any marked degree, it could hardly fail of detection by reason of the sweet taste imparted to the milk. Cane sugar in milk may be detected * by boiling 5 to 10 cc. of the sample with about o.i gram of resorcin and a few drops of hydrochloric acid for a few minutes. In the presence of cane sugar, a rose-red color is pro- duced. According to Richmond, cane sugar may be estimated by first ascer- taining the total polarization of the sample as in the estimation of milk sugar (p. 147). The milk sugar is then determined by Fehling's solution (pp. i4g to 150) either volumetrically or gravimetrically. The difference between the anhydrous milk sugar found by the latter, or Fehhng method, and that calculated by dividing the polarization by 1.2 17 will give the percentage of cane sugar present. Cotton's t method of detecting cane sugar, when present to the extent of 0.1%, consists in mixing in a test-tube 10 cc. of the suspected milk with 0.5 gram of powdered ammonium molybdate, and adding to the mixture 10 cc. of dilute hydrochloric acid (i to 10). Ten cc. of milk of known purity, or 10 cc. of a 6% solution of milk sugar are similarly treated by way of comparison. Both tubes are placed in a water-bath and the temperature gradually raised to 80° C. If cane sugar is present, an intense blue coloration is produced, while the genuine milk or the solution of milk sugar remains unchanged at the temperature of 80°. If the tem- perature is raised to the boihng-point, however, the pure milk or milk sugar solution may also turn blue. Detection of Starch in Milk. — A small quantity of milk is heated in a test-tube to boiling, cooled, and a drop of iodine in potassium iodide added. A blue coloration indicates starch. * Richards and Woodman, Air, Water, and Food, p. i66. t Abs. Analyst, 1S98, p. 37. 1 86 FOOD INSPECTION AND ANALYSIS. Condensed Skimmed Milk as an Adulterant. — The use of condensed unsweetened -skimmed milk to raise the solids of a skimmed or watered milk above the standard has been noted in Massachusetts. This sophis- tication is rendered apparent by the abnormally high solids not fat of the sample, which in some instances have exceeded ii%. A sohd not fat in excess of io% is suspicious of this form of adulteration. By fixing a legal standard for both fat and solids not fat, such tampering with milk may readily be checked. Analysis of Sour Milk. — It occasionally becomes necessary for the analyst to deal with samples of sour milk, especially in the summer-time, when the milk has been brought from a long distance. While the process of lactic fermentation results in the formation of traces of volatile acids, unless the sample has become so badly curdled as to render an even homo- geneous mixture of the various parts impossible, a fair determination of the solids and fat can readily be made. Experience has proved that, excepting in instances of milk so badly soured as to have become actually putrid, the analysis of sour milk, if carefully made, should not differ materially from that of the same milk before souring. Care must be taken to secure an even emulsion of the curd and whey. This may sometimes be accomphshed by repeatedly pouring the sample back and forth from one container to another. Again, it is sometimes necessary to use an egg-beater of the spiral wire pattern, which preferably should easily fit the can or milk-container. Unless a fine, even emulsion can be secured, it is impossible to make a satisfactory analysis of sour milk. With such an emulsion results can be relied on. In measuring portions of the thoroughly mixed sample of sour milk for analysis, a pipette should be used having a large opening.* CONDENSED MILK. Canned condensed milk has become a very important article of food, its use having increased considerably during the last few years. The universally accepted meaning of the term ' ' condensed milk" in this country is milk both condensed and preserved with cane sugar, being what is com- monly known in England as "preserved milk." The unsweetened variety is more often termed ' ' evaporated cream " and sold as such. It is, however, * A pipette open to the full size of the tube is convenient for this work. MILK. 187 3S found on the market usually nothing better than condensed ordinary milk, having no added sugar, and has generally no resemblance in com- position to cream other than in consistency. Condensed milk is usually prepared by boiling milk in vacuum-pans under diminished pressure to the proper degree of concentration. Up- wards of 350 samples of sweetened condensed milk have been analyzed in full in the laboratory of the Massachusetts State Board of flealth in the course of eight years, representing no less than no brands, together with about 30 samples (representing 8 brands) of the unsweetened variety. In view of the fact that a considerable number of the condensed-milk samples are shown by their analysis to have been produced from skimmed milk, the fat content in the samples analyzed varying from a mere trace to 12%, it is obvious that the typical composition of condensed milk could not fairly be shown by giving maximum, minimum, and mean results from the entire tabulated series, nor would it be possible to draw a hard- and-fast hne excluding certain samples known to be adulterated in making up the averages. It has therefore been thought best to select a few typical brands and give their analyses in full. COMPOSITION OF SWEETENED CONDENSED MILK. Points to be Noted. Total Water Per Milk Cane Milk Pro- SoUds, Solids, Sugar, Sugar, teins, Per Cent. Per Per Per Per Cent. Cent. Cent. Cent. Cent. 79.17 20.83 31.32 47.85 9.57 7.95 68.70 32.30 30.27 38.43 6.38 10. 70 6g.3o 30.70 31.83 37.47 16.7s 6.34 74-29 25.71 32.37 41.92 11.97 8.46 69.30 30.70 29. IS 40. IS 11.89 12. IS 69.06 30.94 25.88 43.18 11.55 11.78 Fat, Per Cent. Ash, Per Cent. Fat in Origi- nal Milk, Per Cent. High in fat, much added sugar High fat, low milk sugar. . . Low fat, high milk sugar; low proteins Normal constituents throughout* Condensed from skimmed milk Condensed from centrifu- gally skimmed milk 1 2 .00 1 1 .46 7 . 20 1 .80 1-73 IS4 10.65 I . 29 3.06 j 2.0s 0.09 2.46 4.60 5. 63 2.77 4.56 X.II Trace COMPOSITION OF UNSWEETENED CONDENSED MILK. Points to be Noted. Total Solids, Per Cent. Water, Per Cent. Milk Sugar, Per Cent. Pro- teins, Per Cent. Fat, Per Cent. Ash, Per Cent. Fat^"J No. of 0"g,',nal Times Milk, Con- -T^'' densed. Cent. High in fat Low in proteins Normal constituents throughout* Condensed from skimmed milk. . 36.00 31 -25 28.16 35.17 64. CO 86.75 69.24 64.83 10.65 13.40 9-85 13-90 11-63 7.02 8.66 15-37 12 .00 9. 60 8.10 4. 20 1.72 1-23 I. 55 1 .70 4.61 4.18 3.68 1.28 2.6 2.3 2. 3 i-i * Can be taken as being very near the average for all constituents in honest condensed miUc of fair quality. 1.88 FOOD INSPECTION AND ANALYSIS. In the case of sweetened condensed milk it will be observed that the proteins as a rule run considerably lower than the sugar, whereas in ordinary cow's milk the percentage of proteins and milk sugar are more nearly alike. In making the above analyses all the reducing sugar was reckoned as milk sugar, whereas it is possible that a small amount of the cane sugar is inverted in the process of manufacture, and thus increases the amount of reducing sugar. U. S. Standards.* — Standard Condensed Milk and Standard Sweetened Condensed Milk are condensed milk and sweetened condensed milk re- spectively, containing not less than 28% of milk sohds, of which not less than 27.5% is milk fat. Standard condensed skim -milk is skim- milk from which a considerable portion of water has been evaporated. The standard for evaporated or condensed milk (unsweetened) has been amended by the Board of Food and Drug Inspection as follows:! (i) It should be prepared by evaporating the fresh, pure, whole milk of healthy cows, obtained by complete milking and excluding all m.ilkings within 15 days before calving and 7 days after calving, pro- vided at the end of this 7-day period the animals are in a perfectly nor- mal condition. (2) It should contain such percentages of total solids and of fat that the sum of the two shall be not less than 34.3 and the percentage of fat shall be not less than 7.8%. This allows a small reduction in total solids with increasing richness of the milk in fat. (3) It should contain no added butter or butter oil incorporated either with whole milk or skimmed milk or with the evaporated milk at any stage of manufacture. ANALYSIS OF CONDENSED MILK. Preparation of the Sample. — Mix the sample thoroughly, best by transferring the entire contents of the can to a large evaporating-dish, and working it thoroughly with a pestle till homogeneous throughout. Weigh 40 grams of the mixed sample, preferably in a tared weighing-tray for sugar analysis, transfer by washing to a graduated loo-cc. sugar- flask and make up to the mark with water. Total Solids. — Dilute an aliquot part of the mixed solution further with an equal amount of water, and pipette 5 cc. of the diluted mixture, corresponding to i gram of the condensed milk, into a tared platinum dish, such as is used for ordinary milk, and rinse the pipette into the * U. S. Dept. of Agric, Off. of Sec, Circ. 19. f Food Inspection Decision, 131. MILK. 189 dish by means of a wash-bottle. Evaporate, dry at the temperature of boiUng water and weigh as in the case of milk (p. 132). The character of the residue should be noted. It should not, excepting in the case of a skimmed milk, be caked down hard and glossy on the bottom of the dish, but, if the operation is properly carried out, should have a well-separated fat layer at the top, and the residue should resemble in appearance that from ordinary milk. This result is accomplished by the extreme dilution of the sample. Ash. — Burn carefully the residue from the total solids as above obtained, cool, and weigh as in the case of ordinary milk (p. 134). When the total solids are not to be determined, as in cases where the quality of the milk used in preparation of the sample is decided by the fat and ash alone (see p. 192), 12.5 cc. of the above 40% solution, corre- sponding. to 5 grams of the sample, may be evaporated and burned directly. Fat. — The Author's Method.^ — Fifteen cc. of the 40% solution pre- pared as above described, corresponding to 6 grams of the original con- densed milk, are measured into an ordinary test-bottle of the Babcock centrifuge. This is filled nearly to the neck with water, and 4 cc. of a solution of copper sulphate of the strength of Fehling's copper solution are added. The contents are thoroughly shaken, and the precipitated proteins, carrying with them the fat are rapidly separated out by whirl- ing the fat bottle in the centrifuge, preferably without heating. The writer prefers an electric centrifuge of the Robinson type (p. 137) for this purpose, as the heat of the steam-driven machine cakes the precipitate down, so that it is harder to wash. If desired, the precipitate may be allowed to settle out of itself, which it does more quickly in the cold. The supernatant liquid containing the sugar is drawn off by means of a pipette of large capacity, having a stem sufficiently small to pass easily into the neck of the milk-bottle, a small wisp of absorbent cotton being first twisted over the bottom of the pipette to serve as a filter. On with- drawing the pipette with the sugar solution, the cotton is wiped off into the bottle by rubbing against the inner side. The precipitated proteins and fat are given two additional washings, as above, by shaking thoroughly with water introduced nearly to the neck of the bottle, separating out in each case by centrifuge or by settling, and finally removing the washings with the pipette, two of such extra washings being found nearly always sufficient to remove all the sugar. If the precipitate is caked down hard after treatment with the centrifuge, * 28th An. Rep. Mass. State Board of Health, 1896, p 630, and Jour. Am. Chem. Soc, 22, 1900, p. 589. IQO FOOD INSPECTION AND ANALYSIS. it may be necessary to employ a stiff platinum wire as a stirrer to aid in mixing with the wash- water. Finally; the volume of 17.6 is completed by addition of water. 17.5 cc. of sulphuric acid are added, and the test continued, as in the ordinary Babcock process (p. 136), multiplying the reading obtained by three. For unsweetened condensed milk, these precautions are, of course, unnecessary. Roese-Gottlieb Method. — This method (p. 199) is recommended when the accuracy of a gravimetric process is desired. Proteins. — Calculation from the Nitrogen. — Determine nitrogen by the Kjeldahl or Gunning method in 5 cc. of the 40% solution, corre- sponding to 2 grams of the condensed milk, and multiply the result by 6.38. Precipitation Method. — Dilute 5 cc. of the 40% solution further to about 40 cc. and add sufficient Fehling copper solution, drop by drop, to precipitate the proteins, avoiding a large excess. As a rule, 0.6 cc. of copper solution is ample for this. Nearly neutralize with sodium hydroxide, leaving the solution still slightly acid. An excess of alkali tends to dissolve the casein and cause turbidity in the filtrate. Pass through a weighed filter-paper, wash, dry in an air-oven at 100° C, and weigh. The filter with the dry precipitate is then carefully burnt m a porcelain crucible, and the difference between the weight of the dry precipitate and the weight of the ash is the weight of the proteins and fat. Expressing this in percentage, and deducting from it the per cent of fat previously obtained, the result is the per cent of proteins. Milk Sugar. — Volumetric Process. — The filtrate and the washings from the preceding operation are made up to 100 cc. with water, and the amount of reducing sugar, obtained volumetrically by Fehling's solution, is reckoned as milk sugar. The titration is conducted in the manner described on p. 591. Assuming the solution to be exactly of the strength above described, 100X0.067 T • \ the milk sugar is calculated as follows: 5x002 "" where L is tlie per cent of lactose or milk sugar, and 5 the number of cc. of milk solution, prepared as above required to reduce 10 cc. of Fehhng's solution. Calculation may be avoided by the use of the following table, which may be employed when the above details are minutely tarried out: MILK. 191 PER CENT MILK SUGAR CORRESPONDING TO NUMBER OF CUBIC CENTIMETERS USED. Strength of solution 2 grams in 1 00 cc. Cu. Cm. Per Cent. Cu. Cm. Per Cent. Cu. Cm. Per Cent. 1 Cu. Cm. Per Cent. 18.0 18.61 25.0 13-40 32.0 10.47 39-0 8-59 18.5 18.10 25-5 13-14 32-5 10.31 39-5 8.49 19.0 17-63 26.0 12.89 ' 32,-° 10.15 40.0 8-37 19-5 17 = 18 26.5 12.64 33-5 10.00 ! 40.5 8.27 20.0 16.75 27.0 12.41 34-0 9-85 41.0 8.17 20.5 16.34 27-5 12.18 34-5 9.71 41-5 S.07 21.0 15-95 28.0 11.97 35-0 9-57 42.0 7.98 21-5 15-58 28.5 11-75 35-5 9-43 42-5 7.88 22.0 15.22 29.0 11-55 1 36.0 9-30 43-0 7.78 22.5 14-89 29-5 11-35 36-5 9.17 43-5 7-70 23.0 14.56 30.0 II. 16 37-0 9-05 44-0 7.61 23-5 14-25 30-5 10.89 37-5 8.93 44-5 7-53 24.0 13-95 31.0 10.80 38.0 8.81 24-5 13-67 31-5 10.63 i ''■-' 8.70 Gravimetric Methods. — Lactose may be determined in the 40% solution of the condensed milk by the O'Sullivan-Defren method (page 150), the Soxhlet method (page 150), or the Munson and Walker method (page 151), the solution being treated exactly as if it were milk. Cane Sugar. — This is obtained by ditTerence, deducting the milk solids (the sum of the milk sugar, proteins, fat, and ash) from the total solids first obtained. Detection of Foreign Fats and Oils. — The invention of the homogenizer has led to the preparation of emulsions of oleo, cotton seed and other oils, as well as of butter fat, with skim milk and milk in imitation of whole milk and cream and the use of such homogenized products in condensed milk and ice cream. This substitution is detected by the separation and examina- tion of the fat as follows : PauPs Method."^ — Dilute 100 grams of the material with 300 cc. of water, heat to boiling and add slowly, while boiling, 25 cc. of Fehling's copper sulphate solution (p. 28). Filter through a filter paper on a Biichner funnel, wash three times with hot water and allow to suck dry. Remove filter and precipitate from the funnel, break into small pieces, dry over night at room temperature and grind with about 25 grams of anhydrous copper sulphate. Place a layer of anhydrous copper sulphate in the bottom of the inner tube of a Johnson extractor (p. 65), then add the powdered mixture and place a loose plug of cotton on the top. Connect the extractor with a flask, pour 50 cc. of ether through the mixture and proceed as usual with the extraction. U. S. Dept., Bur. of Chem., Circ. 90, p. 10. 192 FOOD INSPECTION AND ANALYSIS. Dry the fat as quickly as possible and weigh. Determine the refractive index, volatile fatty acids and such other constants as seem desirable (Chapter XIII). Calculation of Fat in Original Milk, — The "fat in the original milk," as expressed in the tables on page 187, was calculated by assuming a percentage of solids not fat of 9.3 in the original milk, this being the standard fixed by the Massachusetts law. Calculate first the fat and the milk soHds to the basis of the cane-sugar-free sample. This is done by divid- ing the per cent of each as found in the sample by 100 less the percentage of cane sugar, and multiplying the result by 100. Ascertain the dif- ference between the milk solids and the fat thus obtained in the cane- sugar-free sample, and divide this percentage of milk solids not fat by 9.3. The result is the "number of times condensed " (if cane sugar were not present as a diluent). The per cent of fat in the cane-sugar-free sample, divided by the number of times condensed, as above obtained, gives the percentage of fat in the original milk. The above calculation from the solids not fat of the factor desig- nated as "the number of times condensed," necessitates determinations of fat, ash, proteins, and milk sugar, in fact, a complete analysis of the sample, A simpler method of calculating the " number of times condensed," involving determinations of fat and ash only in the sample, consists in dividing the per cent of ash found in the condensed milk by 0.7, this figure being the assumed ash of normal, standard milk. Then, by divid- ing the fat in the sample by the " number of times condensed " as last calculated, the result is the fat in the original milk. If this is found to be well below 3%, there is reason to suspect that skimmed milk was used in its preparation. The " fat in the original milk " as thus calculated is, of course, an arbitrary factor and is useful only in deciding whether or not skimmed milk has been used in preparing the sample. By assuming the above very reasonable figures for the solids not fat, or for the ash of natural milk (according to which method is used for calculation), it is readily seen that the highest result is obtained for the " fat in the original milk " and hence the benefit of the doubt as to the use of skimmed milk is given to the manufacturer. Bigelow and McElroy's Polarimetric Method for Cane Sugar.* 26,048 grams of the mixed sample of condensed milk are transferred to a loo-cc. * Jour. Am. Chem. Soc, 15, p. 668. MILK. 193 graduated sugar-flask and dissolved in water, which is boiled to make sure of normal rotation. The solution is then clarified by the addition of an acetic acid solution of mercuric iodide * and, if necessary, alumina cream, the volume is made up to 100 cc, shaken, and filtered through a dry filter. Rejecting the first part of the filtrate, a further portion is polarized. For inversion, another sample of 26.048 grams is weighed out as before and dissolved, but before clarifying, is heated to 55° C. and treated with half a cake of compressed yeast, the heating with the yeast being continued at 55° for five hours. The clarifying solution is added before coohng, and, after coohng, making up to 100 cc, and filtering as before, the invert reading is obtained with the polariscope. By this process of yeast inversion the cane sugar only is inverted, the iactose remaining unchanged. It is best to work with several samples and use the mean of the readings both for direct and invert figures. It is also best to use the double dilution method (p. 149) to compensate for the volume of the precipitated fat and proteins. The per cent of cane sugar is calculated by the formula of Clerget, a—b S = 142.66 — 2 S being the per cent of cane sugar, a the direct reading, b the invert reading and t the temperature at which the observation is made. The above process presupposes the absence of invert sugar in the sample, a supposition which Wiley claims it is fair as a rule to assume. CREAM. Composition. — Cream varies in composition according to the method by which it is obtained, i.e., whether (i) by allowing it to separate from the milk set in shallow pans, whence it is removed by hand-skimming, (2) by setting in deep vessels surrounded by cold water (as for example in the "Cooley" creamer) the skimmed milk being commonly drawn off from below, or (3) by the centrifugal separator. Most of the heavy cream found in the market at the present time is the product of the third or separator process. Analyses of different kinds of cream follow : * Prepared by dissolving 53 grams of potassium iodide, 22 'grams mercuric chloride, and 32 cc. of strong acetic acid in water and making up to 1 liter. 194 FOOn INSPECTION yIND ANALYSIS. COMPOSITION OF CREAM, Character of Cream. •5 < u i '3 < -a By natural separation By centrifugal separator, "Heavy" cream 46 18 18 Konig Leach Leach Mean Maximum Minimum Mean Maximum Minimum Mean 68.82 54,80' 46.76 SI. 68 83.29 70.50 77.89 3-76 22.66 4.23 0-53 31.18 53-24 45.20 48.32 29.50 16.71 22.11 8.42 8.50 4.20 6.30 9-30 7.22 8.25 "Light" cream 38.10 42.02 21.60 8.60 13.86 U. S. standards.* — Standard Cream is cream containing not less than 18% of milk fat. Standard Evaporated Cream is cream from which a considerable portion of water has been evaporated. Adulteration of Cream. — In some localities fat standards are fixed for cream both " heavy " and " light," those falling below such standards being deemed adulterated. Foreign Fats. — Oleo oil, possibly other fats, " homogenized " or emulsified with milk or skim milk, is now being substituted for true cream- A product known as " Syntho " belongs in this class but is sold by its manufacturers under its true name. ■ Fio. 53. — A Babcock Cream-test Scale. Preservatives. — The same preservatives are employed in cream as in milk. * U. S. Dept. of Agric, Off. of Sec, Circ. 19. MILK. 195 Gelatin. — The author has detected this substance in cream sold in Massachusetts. It serves as a thickener and is sometimes sold in powder form mixed with boric acid. Sucrate of Lime in Milk and Cream. — Pasteurizing reduces the con- sistency of cream so that its apparent richness and its value for certain culinaiy preparations is impaired. Babcock and Russell * have shown that sucrate of lime (''viscogen") may be used to thicken such cream, but insist that the treated product be sold under a distinctive name, such as " visco-cream " or "pasteurized visco-cream." To prepare "viscogen" dissolve 2 J parts by weight of cane-sugar in 5 parts of water, add, after straining, i part of quicklime slaked in 3 parts of water; shake, allow to settle, siphon off the supernatant liquid, and bottle. For thickening cream use two-thirds of the amount required to neutralize its acidity. It will also thicken milk and condensed milk. ANALYSIS OF CREAM. Total solids, ash, sugar, proteins, and fat (gravimetric) are deter- mined by the methods used in milk analysis (pp. 130-155). Determination of Fat. — Babcock Process. — Owing to the viscosity of cream and its variation in density strictly accurate results can be secured only by weighing the sample. Fig. 53 shows a cream scale provided with a sliding poise for balancing the bottle and a second for weighing the cream. If a large number of tests are to be made, a balance for weighing several samples on each pan or the Wisconsin hydrostatic cream balance will be found convenient, f The latter, devised by Babcock and Farring- ton,{ is constructed on the principle of the lactometer. It is provided with a pan on the top of the stem for holding the test bottle and weights. Two forms of test bottles are shown in Fig. 54. Others with grad- uations up to 50% are also obtainable. The process is as follows: Weigh 9 or 18 grams of the well-mixed sample into the tared test bottle, using a pipette with a wide delivery tube. If 9 grams are used dilute with 9 cc. of water. Add 17.5 cc. of sulphuric acid of proper strength and proceed as in the case of milk (p. 138), The error due to the curved meniscus of the fat colunm in the test * Wisconsin Exp. Station, Bull. 54. t Farrington and Woil, Testing Milk and its Products, 20th ed., pp. 81-83. % Wisconsin Exp. Station Bui. 195. 196 FOOD INSPECTION AND ANALYSIS. r? bottle may be overcome by adding a few drops of fat-saturated alcohol (Babcock and Farrington *) or of glymol (Hunzikerf). To prepare fat-saturated alcohol place a teaspoonful of butter m a bottle with 200 cc. of denatured or wood alcohol, warm slightly and shake until saturated. Coloring matter m.ay be added to further facilitate the reading. Glymol may be colored with alkanet root. Detection of Foreign Fats. — Determine the refractive index and the volatile fatty acids of the fat obtained by the Babcock method. Detection of; Preservatives. — See pp. 180- 183. In testing for formaldehyde, using ferric chloride and hydrochloric acid, the sample should be diluted with an equal volume of water, heated with the reagents in a casserole but finally poured into a test tube to observe the color. Detection of Gelatin. — Stokes Method. X — The reagents are as follows: (i) Acid nitrate of mercury, prepared by dissolving metallic mercury in twice its weight of concentrated nitric acid (sp. gr. 1.42) and diluting with Fig. 54 -^Varieties of Babcock Test Bottle for Cream. A, Bartlett Bottle ; B, Winton twenty-five times its bulk of water, and (2) a saturated aqueous solution of picric acid. To about 10 cc. of the cream add the same amount of the acid nitrate of mercury solution and 20 cc. of cold water. Shake the mixture vigor- ously and allow to rest for five minutes, after which filter. If much gelatin is present, the filtrate will not be clear, but opalescent. To the whole or a part of the filtrate add a few drops of the picric acid solution. If gelatin be present in any considerable amount, a yellow precipitate is forrocd. Avoid an excess of acid nitrate of mercury, as this would cause a precipitate with picric acid. If gelatin is present in small amount only, a cloudiness is produced, best SPen against a dark background. The reaction is delicate to i part of gelatin in 10,000 parts of milk or cream. * Wisconsin Exp. Station, Bull. 195, p. 6. 1i Purdue, Ind. Exp. Station, Bui. 145, XV, p. 593. X Analyst, 22, p. 320. MILK. igj Detection of Sucrate of Lime. — This is indicated by the presence of sucrose, in connection with an abnormally high alkalinity of ash and excessive calcium oxide. The tests are as follows: Lythgoe's Modification of Baier and Neuman's Test for Detecting Sucrose.* — To 25 cc. of milk or cream, add 10 cc. of a 5% solution of uranium acetate, shake well, allow to stand for 5 minutes, and filter. To 10 cc. of the clear filtrate (in the case of cream use the total filtrate, which will be less than 10 cc.) add a mixture of 2 cc. saturated ammo- nium molybdate and 8 cc. dilute hydrochloric acid (i part 2^% acid and 7 parts water), and heat in a water-bath at 80° C. for 5 minutes. If the sample contains sugar, the solution will be of a Prussian blue color, which should be compared in a colorimeter with standard Prussian blue solution, prepared by adding a few drops of potassium ferrocyanide to a solution of i cc. of 1% ferric chloride in 20 cc. of water. Occasional samples of pure milk will give a pale blue color, but this can be entirely removed by filtration, the filtrate being green, while the color due to sugar will pass through the filter, giving the usual blue solution. This color, due to a reduction of molybdic acid, is also produced by levulose and dextrose. Solutions of i gram of lactose, levulose, dextrose, and sucrose in 35 cc. of water heated with molybdenum reagent for 5 minutes reacted as follows: lactose no color, levulose a heavy blue, sucrose a weaker blue, and dextrose the weakest blue, the intensity of the last three being as 10:3 : 1. Stannous chloride, ferrous sulphate, and hydrogen sulphide give this blue color in the cold, but it disappears on heating except in case the stannous or ferrous salt is present to the extent of at least i*^ (calculated as the metal) w^iich amount would coagulate the cream and impart a very disagreeable taste. As a confirmatory test for sugar, the resorcine test may be applied to the serum prepared with uranium as described above. This test is given by sucrose and levulose, but not by dextrose or lactose. Determination of Alkalinity of Ash and Calcium Oxide. — Weigh 25 grams of cream into a platinum dish, place in an oven at about 125-150° C. over night, and burn to an ash in a mufile at a low-red heat. Dissolve the ash in 20 cc. N/io sulphuric acid, boil to expel * Zeits. Unters. Nahr. Genussm., 16, 1908, p. 51 198 FOOD INSPECTION AND ANALYSIS. the carbon dioxide, and titrate back with N/io sodium hydroxide,' using phenolphthalein as the indicator. Express resuhs as cc. N/io acid required to neutrahze the ash of 100 grams of cream. Make the final solution of the above determination acid with acetic acid, heat to boiling, add i gram of sodium acetate, and to the clear solution add an excess of ammonium oxalate, boil for a few minutes, filter, and wash with water. Dissolve the calcium oxalate in hot dilute sulphuric acid, and titrate hot with N/io potassium permanganate. The number of cubic centimeters of N/io permanganate, multiplied by 0.0112 (4X0.0028), gives the percentage of CaO in the sample. Cream samples treated with calcium sucrate, having a fat content from 26 to 33%, show as a rule an alkalinity of ash of from 14 to 18, and a CaO content of from 0.15 to 0.175% while the same untreated show in general alkalinity of ash not exceeding 12.5 and a CaO content not exceed- ing 0.135. With higher fat contents both constants drop. For example, a cream of 45% fat containing calcium sucrate had an alkalinity of ash of 10.2 and a CaO content of 0.12%. Cream of about 45% fat untreated had an ash alkalinity of 6.5 and a CaO content of 0.103%. ICE CREAM. For many years a wide variety of iced foods have been made and sold under the general name of ice cream, many of which are largely composed of ingredients other than milk or cream. In the study and classification of foods of such a miscellaneous nature as ice cream, in its popularly accepted meaning, it is not always easy to satisfactorily define and fix standards. AVhether, for example, the product should consist exclusively of frozen cream, sugar and flavoring, or whether eggs and other materials should be allowed under the unqualified name of ice cream, is a subject of some controversy. Properly speaking, many mixtures sold under the name should be otherwise designated, as, for example, " frozen custard," to specify more aptly their nature and composition. The following standards show the attitude of the government in this regard: U. S. Standards.* — Ice cream is a frozen product made from cream and sugar with or without a natural flavoring, and contains not less than 14% of milk fat. * U. S. Dept. of Agric, Office of Secretary, Circ. 19. MILK. 199 Fruit ice cream is a frozen product made from cream, sugar, and sound, clean, mature fruits, and contains not less than 12% of milk fat. Nut ice cream is a frozen product made from cream, sugar, and sound, non-rancid nuts, and contains not less than 12% of milk fat. Fillers or Stiffeners.— In the manufacture of commercial " ice cream " substances are frequently added to cause the product to hold stiff and keep its consistency for many Hours after freezing. The thickeners or fillers most commonly thus used are starch, gelatin, and gums such as gum tragacanth. Agar-agar and commercial casein are also said to be employed for this purpose. Preparations are on the market sold for thickening ice cream, con- sisting, as a rule, of one or more of the above-named substances. Homogenized Products. — Unsalted butter emulsified with milk or skim milk is now extensively substituted for true cream in the manufacture of so-called ice cream. Oleo oil and cotton seed oil are also used in such emulsions. None of these emulsions are allowable in the product sold as ice cream. Ice Cream Cones. — These are cornucopias made of a kind of dry crust used to serve ice cream without a spoon, the cones as well as the ice cream being eaten from the hand. In addition to flour, sugar, and eggs or gelatin, which are proper constitutents, they frequently contain saccharin, artificial color and borax, the latter being used to prevent sticking to the mold during baking. ANALYSIS OF ICE CREAM. Fat. — Roese-Gottlieh Method."^ — Prepare a 40% water solution, as described for condensed milk (p. 188). Of this solution measure 10 cc. into a Rohrig tube f (Fig. 55), or a glass cylinder 2 cm. in diameter and 40 cm. high, to which a narrow siphon can be fitted; dilute with 0.5 cc. of water, add 1.25 cc. of concentrated ammonium hydroxide (2 cc. if the sample is sour) and mix thoroughly. Add 10 cc. of 95% alcohol and shake well. Then add 25 cc. of washed ethyl ether, shake vigorously for half a minute, add 25 cc. of petroleum ether (p. 66), preferably re- distilled below 60° C, and shake again for half a minute. Let stand * Roese, Zeits. Angew. Chem., 1889, p. 100; Gottlieb, Landw. Versuchs-Stat., 40, 1892, p. i; Patrick, U. S. Dept. of Agric, Bur. of Chem., Circ. 66; A. O. A. C. Method, t Zeits. Unters. Nahr. Genussm., 9, 1905, p. 531. 200 FOOD INSPECTION AND ANALYSIS. twenty minutes or until the upper liquid is clear and its lower level constant. Draw off as much as possible of the ethereal liquid — usually 0.5 to 0.8 cc. is left — through a diminutive filter into a weighed flask. Extract the liquid remaining in the tube in the same manner as before except that only 15 cc. each of the ethers are used, draw off through the same paper into the flask and wash with a few cc. of the mixed ethers (1:1). Evaporate the drawn off and filtered liquid slowly and dry in a boiling-water oven, one hour at a time, to constant weight. The ether used must be tested for residue upon evaporation and a correction introduced if neces- sary. The dried and weighed fats should be dissolved in a little petroleum ether; if a residue be found (due to a trace of the aqueous Hquid which may have passed the filter) it must be washed in the flask, dried, and its weight deducted from that of the crude fat. This method is also applicable to condensed milk, cream, milk, skim milk, buttermilk, and whey. With substances of low fat content the second extraction may be omitted, the weight of the fat being increased to Fig. 55.— Rohrig correspond to the entire volume of ethereal liquid ^^'/-''u^rT" measured in the tube. Gottlieb Meth- ^ . -^.-r-., i^-io ■, ^ Detection of Foreign Fats and Oils. — Separate and examine the fat as described on page 191. Detection of Thickeners. — Patrick's Method.'^ — Add 25 cc. of water to 50 cc. of the sample, and boil till any thickener present is dissolved. Add 2 cc. of a 10% solution of acetic acid, heat to boiling, add 3 leap- ing teaspoonfuls of kieselguhr, and after shaking pass at once through a plaited filter. To 3 cc. of the clear filtrate add 12 cc. of 95% alcohol and mix thoroughly, thus precipitating the milk proteins not already removed, and also the gums and some of the gelatin, if much is present. Add 3 cc. of a mixture of 95 cc. of 95% alcohol and 5 cc. of concen- trated hydrochloric acid. This acidified alcohol dissolves completely the milk proteins, and, if a clear solution then remains, no gums or vegetable jellies have been used as thickeners. Turbidity does not, however, U. S. Dept. of Agric, Bur. of Chem., Bui. 116, p. 26. MILK. 20 1 necessarily indicate presence of a thickener, as it may be caused bv a large amount of eggs, or by the souring of the ice cream. Dilute the mixture, if turbid, by adding 3 cc. of water. Any precipitate due to gelatin or eggs will be dissolved at this dilution, but not that due to vegetable gums. If gum tragacanth be present, the precipitate will be f stringy and cohesive, especially after shaking, while agar-agar or other vegetable thickeners will cause a fine flocculent precipitate. Souring of the ice cream sometimes produces a turbidity or precip- itate under the above conditions, which is not always dissolved after diluting with water. Formation of such a precipitate (due to sourness) may, however, apparently be prevented by the previous addition of formaldehyde to the sample. Howard's Test for Gums. — Precipitate 10 cc. of the melted sample with acetone, and wash with 2 or 3 portions of dilute alcohol, using the centrifuge. Boil the washed residue with 6 to 8 cc. of water and I cc. of 10% sodium hydroxide solution for half a minute. Cool, let stand a few minutes, filter, and heat the filtrate to boiling. Add one and one-half volumes of warm alcohol and shake. If agar-agar or gum tragacanth be present, a flocculent precipitate will immediately sepa- rate. Disregard a mere turbidity. To prove the absence of any con- siderable quantity of milk proteins in the precipitate, dissolve in cold water and saturate the solution with ammonium sulphate. Gelatin. — Use the method of Stokes (p. 196) on 10 to 15 cc. of the sample, disregarding a faint cloudiness at the end. Starch is detected by the usual iodine test. Detection of Preservatives.— Formaldehyde and boric acid are tested for as in milk. Detection of Colors.— -See Chapter XVII. The colors used are not mei^ly yellows and oranges such as are added to milk, but include also reds, greens, and even blues, coal-tar dyes being most commonly employed. BUTTER. The value of butter as a food depends almost entirely on its fat con- tent, although minute quantities of protein and milk sugar are also in- cluded in its composition. Hence butter is more logically treated in detail under the heading of fats, page 529. FOOD INSPECTION AND /IN A LYSIS. CHEESEo Nature and Composition. — Cheese consists principally of the curd and fat removed in a mass from milk, which has been curdled by the natural souring of the milk, or by the action of rennet. The separated mass of curd and fat, after being compressed, is allowed to undergo certain changes, which constitute the ripening or curing, due to the action of micro-organisms and enzymes. Sometimes cream is used as the source of cheese and sometimes skimmed milk. During the ripening process, which requires from a few weeks to several months, the characteristic flavor is developed by the changes which the proteins undergo, and the digestibility of the cheese is improved. The nature of the proteolytic changes that take place during ripening are very little understood, but a variety of complex nitrogenous products are formed, which Van Slyke divides as follows: paracasein, unsaturated paracasein lactate, para- nuclein, caseoses (albumoses), peptones, amides, and ammonia. Besides nitrogenous bodies and fat, which are its chief constituents, cheese con- tains notable quantities of water, milk sugar, lactic acid, and mineral matter. In some kinds of cheese salt and coloring matter are added. Varieties. — Well-known cheeses of commerce are often named from districts, towns, or locahties where they originated or are still made. They may be classified as cream, whole-milk, or skimmed-milk cheese, according to the quality of the product from which they are made, or again as hard, medium, or soft, according to whether (i) they are pressed, or (2) allowed to drain for days and sometimes weeks without pressure to a firm consistency, or (3) are made in the space of a few hours, being quickly drained on a sieve by hand pressure. Cheddar Cheese, which is the common cheese of the United States (though originally made some 250 years ago in England and still made there), is a type of the hard cheese. Stilton, an English, and Gruyere, a Swiss cheese, belong to the medium class, and soft cheeses are represented by Brie and Neufchatel, both French cream cheeses. Other well-known varieties are Edam, a round, mild, long-keeping Dutch cheese, Camemhert, a rich cream cheese, and Roquefort, made originally from ewe's milk in the French town of that name, and ripened in caves in the mountains. It is flavored by a peculiar mold. MILK. 203 The following table, compiled by Woll,* shows the average composition of various cheeses of commerce, both foreign and domestic: Water. Casein. Fat. Sugar. Ash. Cheddar Cheshire Stilton Brie Neufchatel Roquefort Edam Swiss Full cream, mean of 143 analyses Per cent. 34-38 Per cent. 26.38 32-51 28.85 17.18 14.60 27.63 24.06 24.44 25-35 Per cent. 32-71 26.06 35-39 25.12 33-70 30.26 37-40 30-25 Per cent. 2-95 4-53 1-59 1. 94 4.24 2.00 4.60 2-03 Per cent. 58 31 Van Slyke has furnished the following analysis of the nitrogen com- pounds in a sample of normal American Cheddar cheese six months old and cured at 60° F. : Per Cent Nin Cheese. Per Cent Water- soluble N. Per Cent Nas Paracasein Mono- lactate. Per Cent N as Para- nuclein. Per Cent N as Caseoses. Per Cent N as Peptones. Per Cent N as Amides. Per Cent N as Ammonia. 3.80 1.46 0.94 0.14 0.22 0.18 0.79 0.13 U. S. standards.!— CAee^e is the sound, solid, and ripened product made from milk or cream by coagulating the casein thereof with rennet or lactic acid, with or without the addition of ripening ferments and seasoning, and contains, in the water-free substance, not less than 50% of milk fat. By act of Congress, approved June 6, 1896, cheese may also contain added coloring matter. Skim-milk Cheese is defined the same as cheese except that it is made from skim milk, and no minimum percentage of fat in the water- free substance is specified. Adulteration. — Cheese is commonly adulterated in two ways: first, by the partial or total substitution for the milk fat of a foreign fat, as oleomargarine or lard, and, second, by using skimmed milk as a mate- rial for its manufacture. In many localities a standard percentage for fat in cheese is fixed by law, as in the case of the U. S. standard noted above, all samples falling below that standard, unless sold as skim-milk cheese, being deemed adul- terated. * Dairy Calendar, p. 223. t U. S. Dept. of Agric., Off. of Sec, Circ. 19. 204 FOOD INSPECTION AND ANALYSIS. Some states have specific standards for varying grades of cheese, classified as to their fat content. Thus under the Pennsylvania law* cheese is divided into five grades, as follows: Full-cream cheese must contain not less than 32% butter fat. Three-fourths cream cheese must contain not less than 24% butter fat. One-half cream cheese must contain not less than 16% butter fat. One- fourth cream cheese must contain not less than 8% butter fat. All cheese having less than 8% fat must be branded " Skimmed Cheese." The term ''filled cheese" is commonly applied to a product in which a foreign fat, as oleo oil or lard, has been used. Filled cheese is more commonly found in localities where a carefully enforced fat-standard law prevails, but, in the absence of a standard for fat in cheese, the manu- facturer can cheapen his product much more readily and conveniently by selling a skim-milk cheese in place of the whole-milk article, though not without producing a sensibly inferior product. METHODS OF ANALYSIS. Obtaining a Representative Sample.- — Method 0} the A. O. A.C.-f — By means of a cheese-trier remove, if possible, three cylindrical plugs from the cheese perpendicular to the surface and in length equal to about half the thickness of the cheese, one at the centre, one near the circumference, and one midway between the two. About one inch in length is cut off from each plug from the end having the rind, and this is discarded. The remaining portions of the plugs are then finely divided and mixed as intimately as possible. In place of the plugs a narrow, wedge-shaped segment may be cut from the cheese, reaching from the circumference to the center, the portions near the rind being removed, and the remainder of the piece being finely divided and mixed as before. Analyses should immediately be begun after obtaining the sample. Determination of Water.- — Two or three grams of the sample are carefully weighed in a tared platinum dish, and dried to constant weight in an oven at 100° C. The loss of weight i? reckoned as water.J * Penn. Laws, 1901, Act. 95, p. 128. * t U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 55. X Previously ignited sand or asbestos is recommended by some as an absorbent to be placed in the dish, but the writer gets better results in most cases directly as above. MILK. 205 Determination of Ash. — Ignite the residue from the moisture determina- tion at a low, red heat, cool in a desiccator, and weigh. Determination of Fat. — Lythgoe's Modified Babcock Method. — Weigh accurately about 6 grams of the sample in a tared beaker. Add 10 cc. of boihng water, and stir with a rod till the cheese softens and an even emulsion is formed, preferably adding a few drops of strong ammonia to aid in the softening and emulsionizing, and keeping the beaker in hot water till the emulsion is tolerably complete and free from lumps. If the sample is a full-cream cheeee, which is usually evident from its taste and appearance, a Babcock cream-bottle is employed. The contents of the beaker, after coohng, are transferred to the test-bottle as follows: Add to the beaker about half of the 17.6 cc. of sulphuric acid regularly used for the test, stir with the rod and pour carefully into the bottle, using the remainder of the acid in two portions for washing out the beaker. Finally proceed as in the regular Babcock test for milk. IMultiply the fat reading by 18 and divide by the weight of the sample taken to obtain the per cent of fat. Short's Method.^ — Grind to a uniform powder 2 to 5 grams of the sample, and about twice its weight of anhydrous copper sulphate. Place a layer of anhydrous copper sulphate about 2 cm. thick on the bottom of the inner tube of a Johnson or Knorr extractor, add the ground mix- ture, and rinse the mortar first with a little anhydrous copper sulphate and finally with ether. Extract for 16 hours, evaporate the ether from the extraction-flask, and dry the fat in a boiling-water oven to constant weight. Werner-Schmidt Method. — Boil 2 to 3 grams of the sample in the Werner-Schmidt tube (p. 139) with 5 cc. of water and 10 cc. of con- centrated hydrochloric acid till, with constant shaking, all but the fat is dissolved. Cool, add 25 cc. of ether, and shake the tube well. Draw off as much as possible of the ether, after separation, in the usual manner, and extract with four or five additional portions of the solvent. Distil off the ether from the combined extractions, and weigh the fat. Determination of Protein. — From i to 2 grams of the cheese are treated by the Gunning or Kjeldahl method, adding after partial diges- tion a piece of copper sulphate the size of a pea to aid in the con- version.! NX 6. 25 = protein. * U. S. Dept. of Agric, Div. of Chem., Bu'. 35, pp. 15, 17, 225. t Van Slyke, N. Y. Exp. Station, Bulletin 215. 2o6 FOOD INSPECTION AND ANALYSIS. Separation and Determination of Nitrogen' Compounds. — Methods of Van Slyke.^ — Twenty-five grams of the sample are mixed in a porcelain mortar with an equal volume of clear quartz sand. Transfer the mix- ture to a 450-cc. Erlenmeyer flask, add about 100 cc. of water at 50° C, and keep the temperature at 50° to 55° C. for half an hour with frequent shaking. Decant the liquid through an absorbent-cotton filter into a 500-cc. graduated flask. Treat the residue with repeated poitions of 100 cc. each of water, heating, shaking, and decanting as above till the filtrate, or water extract, at room temperature amounts to just 500 cc. exclusive of the fat floating on top, and use aliquot parts of this water extract for the various determinations. Water-soluble Nitrogen. — Determine the nitrogen by the Gunning method in 50 cc. of the above water extract, corresponding to 2.5 grams of cheese. Nitrogen as Paranudein. — Add 5 cc. of a i % solution of hydrochloric acid to 100 cc. of the above water extract (corresponding to 5 grams of cheese), and keep the temperature at 50° to 55° till the separation is com- plete, as shown by a clear supernatant liquid. Filter, wash the precipi- tate with water, and determine the nitrogen therein by the Gunning method. Nitrogen as Coagulable Protein. — Neutralize the fikrate from the preceding determination with dilute potassium hydroxide, and heat at the temperature of boiling water till the coagulum,t if any, settles com- pletely. Filter, wash the precipitate, and determine the nitrogen therein. Nitrogen as Caseoses. — Treat the filtrate from the preceding with i cc. of 50% sulphuric acid saturated with C. P. zinc sulphate, and warm to about 70° C. till the caseoses settle out completely. Cool, filter, wash with a saturated solution of zinc sulphate acidified with sulphuric acid, and determine the nitrogen in the precipitate. Nitrogen as Amides and Peptones. — Place 100 cc. of the water extract of cheese in a 250-cc. graduated flask, add i gram of sodium chloride and a solution containing 12% of tannin, till the addition of a drop to the clear supernatant liquid does not further precipitate. Dilute to the 250-cc. mark, shake, pour upon a dry filter, and determine the nitrogen in 50 cc. of the filtrate, which gives the amount of nitrogen in the amido-acid and ammonia compounds. Deduct from this the amount of * Van Slyke, N. Y. Exp. Station, Bulletin 215. t According to Van Slyke a precipitate at this point is rare in cheese. MILK. 207 nitrogen as ammonia separately determined, and the difference is the amido-nitrogen. Nitrogen as peptones is obtained by subtracting the sum of the amounts of nitrogen as paranuclein, coagulable proteins, caseoses, amido-bodies, and ammonia from the total nitrogen in the water extract. Nitrogen as Ammonia. — Distil 100 cc. of the filtrate from the above tannin-salt precipitation into standardized acid, and titrate in the usual manner. Nitrogen as Paracasein Lactate. — Treat the residue insoluble in water in obtaining the water extract, with several portions of a 5% solution of sodium chloride, to form a 500-cc, salt extract of the same, in an analogous manner to that employed in preparing the water extract. Determine the nitrogen in an aliquot part of this salt extract. Determination of Lactic Acid.* — Add water to 10 grams of the cheese sample at 40° C. till the volume equals 105 cc. Shake and filter. Titrate 25 cc. of the filtrate (equivalent to 2.5 grams of cheese) with tenth-normal sodium hydroxide, using phenolphthalein as an indicator. Each cubic centimeter of decinormal alkali is equivalent to 0.009 gram lactic acid. Determination of Milk Sugar. — Boil 25 grams of finely divided cheese with two successive portions of about 100 cc. each of water, decant through a fiher, and finally transfer the residue upon the filter and wash with hot water. Make up the entire aqueous extract thus obtained, when cold, to 250 cc, and determine the milk sugar by either Fehling method. Detection of Foreign Fat. — The cheese fat, separated in the manner described below, is subjected to the various processes detailed under butter, in precisely the same way, the fat of cheese being identical with that of butter. The most ready means for judging its purity consists in determining the refraction with the butyro-refractometer, and the Reichert number. Separation of the Fat for Examination. — Place a quantity, say 25 grams, of the finely divided sample in a large Erlenmeyer flask, add about 100 cc. of petroleum ether, cork the flask and allow it to stand for several hours with frequent shaking. Decant the petroleum ether through a filter, evaporate off the solvent by the aid of heat, and the residue will be found to consist of nearly pure fat. Or, wrap a sufficient portion of the finely divided sample in a muslin * U. S. Dept. of Agric, Bureau of Chem., Bui. 46, p. 56, 208 FOOD INSPECTIOIV AND ANALYSIS. cloth, place this in a dish, and heat on the water-bath. The fat which runs out is afterward filtered and dried at ioo°. Sufficient cheese fat may usually be obtained for the refractometer reading from the neck of the test-bottle, after completing the Babcock test, and, usually (except in the case of skimmed-milk cheese), for the Reichert number. Detection of Skimmed-milk Cheese.^In a cream cheese the fat should greatly exceed the protein; in a whole-milk cheese the per cent of fat should at least equal that of the protein, and is generally in excess. If the fat is considerably less than the protein, the cheese has undoubtedly been made from skimmed milk. The following analyses, made in the writer's laboratory, illustrate these grades: Varieties of Cheese. Water. Fat. Protein.* Ash. Full cream (soft). 37-63 21.89 55-95 62.17 72.80 47.40 38.00 24.00 15.20 2.00 13.70 37-71 16.49 21.36 23-52 1.27 Whole milk (hard) 2.40 Whole milk (soft) Skimmed milk (soft) Centrifugally skimmed milk (soft).. 3-56 1.27 1.68 * By difference. REFERENCES ON MILK AND ITS PRODUCTS.* Arkman. Milk, its Nature and Composition. London, 1899. Baier, E., und Neumann, P. Ueber den Nachweis und die Beurteilung von Zucker- kalkzusatz zu Milch und Rahm. Zeits. Unters. Nahr. Genussm., 16, 1908, p. 51. Conn, H. W. Milk Fermentations. U. S. Dept. of Agric, Off. of Exp. Station, Bui. 9. • — - Dairy Bacteriology. U. S. Dept. of Agric, Off. of Exp. Station, Bui. 25. Conn, H. W., and Esten. The Ripening of Cream. Storrs Exp. Station, Annual Report, 1900. DoANE, C. F., and Lawson, H. W. Varieties of Cheese. U. S. Dept. of Agric, Bur. of An. Ind., Bui. 146, 191 1. Ellis and Kenrick. Milk and Milk Adulteration. Canada. Int. Rev. Dept., Buls. 21, 28. Faerington, E. H., and Woll, F. W. Testing Milk and its Products. Madison, 1912. Fleischmann, W. Lehrbuch der Milchwirthschaft. Bremen, 1893. Frear, W. American Milk and Milk Standards. Assn. State and Nat. Dairy and Food Depts., Proc, 1906, p. 172. Frerichs, K. Ueber den Nachweis von Zuckerkalk in Milch imd Rahm. Zeits. Unters. Nahr. Genussm., 16, 1908, p. 682. Gerber, N. Die Praktische Milch-Pruefung. * For references en Butter, see p. 56: MILK. 209 Grotenfelt, G. The Principles of Modern Dairy Practice. New York. Herz, F. J. Untersuchung der Kuhmilch. Berlin, 1889. Howard, C. D. The Analysis of Ice Cream. Jour. Am. Chem. Soc, 29, 1907, p. 1622. HussoN, C. Le Lait. Paris, 1878. KiRCHNER, W. Handbuch der Milchwirthschaft. Berlin, 1891. Ladd, E. F. Proteids of Cream. Jour. Am. Chem. Soc, 20, 1898, p. 858. Leach, A. E., and Lythgoe, H. C. The Detection of Watered Milk. Jour. Am. Chem. Soc, 1904, 26, p. 1195. Le Clerc, J. A. Dairy Products. U. S. Dept. of Agric, Bureau of Chemistry, Bui. 65, p. 35. Leffman, H., and Beam, W. Analysis of Milk and Milk Products. Philadelphia, 1893. Lehmann, J., und Hempel, W. Die Milchuntersuchungen. Bonn, 1894. Macfarlane, T. Milk and Milk Adulteration. Canada Inl. Rev. Dept., Buls. i, 2, 9> ii> 17, 32, 43. 61, 74, 80. • Cheese. Canada Inl. Rev. Dept., Bui. 6. Butter. Canada Inl. Rev. Dept., Bui. 16. Matthes, -H., u. Muller, F. Ueber die Untersuchung des Milchserums mit dem Zeiss'schen Eintauchrefraktometer. Zeits. fur offentl. Chem., 1903, p. 173. McGiLL, A. Condensed Milk. Canada Inl. Rev. Dept., Buls. 54, 69. Otto, A. Die Milch und ihre Produkte. Berlin, 1892. Pearmain, T. H., and Moor, C. G. The Analysis of Food and Drugs. Part I. Milk and Milk Proteids. London, 1897. Pearson, R. A. National and State Dairy Laws. U. S. Dept. of Agric, Bureau of An. Ind. Bui. 26, 1900. Richmond, H. D. Dairy Chemistry. London, 1889. Russell, H. L. Dairy Bacteriology. Madison, 1899. Scherer, R., trans, by Salter, C. Casein: Its Preparation and Technical Utiliza- tion. London, 1906. Scholl. Die Milch. Schrodt, M. Anleitung zur Prufung der Milch u. s. w. Bremen, 1892. Sherman, H. C. Seasonal Variations in the Composition of Cow's Milk. Jour. Am. Chem. Soc, 28, 1906, p. 1719. On the Composition of Cow's Milk. Jour. Am. Chem. Soc, 25, 1903, p. 132. Snyder, H. The Chemistry of Dairying. Easton, 1897. Stutzer, a. Die chem. Untersuchung der Kase. Zeits. f. anal. Chem., 1886, p. 493. Swithinbank, H. Bacter'ology of Milk. 1903. Tourchot, a. L. Milk ; nd Milk Adulteration. Canada Int. Rev. Bui. 53. Van Freudenreich, E. Die Bakteriologie in der Milchwirthschaft. Basel, 1893. Van oLYKe. Modern Methods of Testing Milk and Milk Products. New York, 1907. WoorMAN, A. G. On the Determination of Added Water in Milk. Jour. Am. Chem. Soc, 21, .1S99, p. 503. Wanklyn, J. A. Milk Analysis. London. Weigmann, H. Die ^lethoden der Milchcons;rvirung. Bremen, 1893. Whitaker, G. M. The Milk Supply of Boston and other New England Cities. U. S. Dept. of Agric, Bur. of An. Ind. Bui. 26, 1900. 2IO FOOD INSPECTION /!ND ANALYSIS. ' ^^ Alabama Exp. Sta. Bui. 97. Dairy and Milk Inspection. Annual Reports of Inspector of Milk and Vinegar, Boston, Mass. " " " " " " Cambridge, Mass. Arkansas Exp. Sta. Bui. 45. Milk, its Decomposition and Preservation. Dairy Products. U. S. Dept. of Agric, Div. of Chem., Bulletin 13, part i, 1887. Die Milchzeitung. Bremen, 1872 et seq. Farmers' Bulletin, No. 2. Bacteria in Milk. " " 20. Milk Fermentation and its Relations to Dairying. " " 29. Souring of Milk. " " 42. Facts about Milk. " " 74. Milk as Food. " " 166. Cheese-making on the Farm. Kansas Exp. Sta. Bui. 88. Keeping Milk in Summer. Maine Exp. Sta. Bui. 23 (New Series). Cream Preservation. Massachusetts State Board of Health Reports, 1883 et seq. Michigan Exp. Sta. Bui. 140. Ropiness in Milk. Minnesota Exp. Sta. Bui. 74. Milk and Cheese, Digestibility and Food Value. New York (Geneva) Exp. Sta. Bui. 70. Reasons for Changing Milk Standards. " " " " " " 215. Estimation of Proteolytic Compounds in Cheese and Milk. " " (Ithaca) " " " 165. Ropiness in Milk. North Carolina Exp. Sta. Bui. 113. Testing of Milk. Oklahoma Exp. Sta. Bui. 21. A New Milk Test. West Virginia Exp. Sta. Bui. 58. Effect of Pressure in the Preservation of Milk. Wisconsin Exp. Sta. Bui. 48. Conn. Cuhure B. 41, in Butter-making. " " " " 52. Babcock vs. Gravimetric Tests for Fat. Acidity in Milk. " " " " 54. Restoration of Consistency of Pasteurized Cream. " " " " 61. Constitution of Milk with Reference to Cheese Produc- tion. " " " "62. Tainted or Defective Milks. " " " " 70. Cheese-cunng. " " " Annual Reports. 12th et seq. Zeitschrift der Fleisch und Milch Hygiene. CHAPTER VIII. FLESH FOODS. MEAT. General Structure and Composition. — Meat is structurally made up of muscle fibers, held together by connective tissue, through which fat cells are usually more or less abundantly distributed. Each muscle fiber has a sheath or covering known as sarcolemma, formed of an albuminoid substance similar to elastin, and within the fibers are contained the meat juices, which are solutions in water of proteins, non-protein-nitrogenous extractives, and salts. The substance of the connective tissue is made up largely of the albuminoids elastin (insoluble) and collagen, the latter being convertible by boiling with water or treatment with acids into gela- tin. The proteins of the meat juices consist chiefly of the globulin myo- sin (by far the most abundant), muscle albumin, and the muscle pigment hcEmogloh'm, or a substance closely analogous thereto. In the living muscle there are no peptones, but the ferment pepsin is present. After death, by the action of the pepsin in presence of lactic acid, a portion of the normal proteins of the muscle undergoes, as it were, digestion, so that in meat both peptones and proteoses * are found. The non-protein-nitrogenous extractives are mainly creatin, xanthin, hypoxanthin, and carnin, which, from their basic character, are known as flesh bases. The approximate proportions in which the chief constituents are present in meat is thus shown by Konig : Water ^-.o to 77.0 ' Sarcolemma (muscle fiber) 13.0 to 18.0 Connective tissue 2.0 to !;.o Albumin 0.6 to 4.0 Creatin 0.07 to 0.34 Hypoxanthin o.oi to 0.03 Creatinin Xanthin . . ._ Undetermined Inosinic acid Uric acid Urea o.oi to 0.03 Nitrogenized compounds. * A proteose or albumose known as myoalburaose normally exists in the live muscle. 211 ^12 FOOD INSPECTION ^ND ANALYSIS. Fat 0.5 to 3.5 r Lactic acid 0-05 to o.oj Butyric acid. I Other nitrogen-free compounds. . J p*"^ ^^ ^''* . ' I Undetermined Inosite J .Glycogen (0.3 to 0.5) Salts '. (0.8 to 1.8) Composed of: Potash 0.40 to 0.50 Soda 0.02 to 0.08 Lime o.oi to 0.07 Magnesia 0.02 to 0.05 Oxide of iron 0.003 to 0.0 Phosphoric acid 0.40 to 0.50 Sulphuric acid 0.003 to 0.04 Chlorine o.oi to 0.07 Nitrogen compounds constitute by far the most abundant and im- portant portion of the substance of lean meat. Carbohydrates are almost entirely lacking, the small amount of glycogen and muscle sugar togethei constituting rarely more than i per cent. Glycogen (CgHioOs), sometimes called animal starch, is a white, amor- phous, tasteless, and odorless substance, when pure, much resembling starch. It is soluble in water, forming an opalescent solution, and is insoluble in ether and alcohol. With iodine a port-wine color is pro- duced, which disappears on heating and reappears on cooling. Glycogen is strongly dextro-rotary. It is converted to dextrose by boiling with dilute mineral acid. Muscle Sugar is either entirely absent m the living muscle, or exists in traces only. After death it is formed presumably from the glycogen, and exists in a very minute quantity, probably as dextrose. Inosite (CeHijOg-f HjO) is found in traces in the muscular substance of the heart, liver, kidneys, and testicles. Proximate Constituents of the Commoner Meats. — The chief charac^ teristics of the flesh of various animals are in the main very similar, what- ever the nature of the animal. So true is this, indeed, that it is extremely difficult from a chemical analysis to distinguish a particular kind of flesh when mixed with that of other animals in finely divided meat preparations^ such as sausages, potted and deviled meats, and the like. The average composition of the commoner cuts of beef, veal, mutton, lamb, and pork, as well as of fowl and game, is shown in the following tables, compiled from the work of Atwater and Bryant,* the accompanying diagrams serving to locate, in the case of ordinary meats, the portion of the animal from which the meat is taken. *U. S. Dept. of Agric, Off. of Exp. Stations, Bui. 28 (Revised Ed.). FLESH FOODS. '^'!i'''WJ^^-^--'^^- 1. Neck 2. Chuck 3. Ribs 4. Shoulder clod 5. Fore shank C. Brisket 7. Cross ribs 8. Plate 9. Navel 10. Loin 11. Flank 12. Rumi) 13. Round It. Second cut .-ound 1). Hind shank Fig. 56. — Diagram Showing Cuts of Beef. COMPOSITION OF BEEF. Cut. Num- ber of Anal- yses. Refuse Water. Protein. N< 6.25. By Differ- ence. Fat. Fuel Value Ash. I per I Pound. Cals. Chuck: Lean — Medium- Fat— Ribs: Lean — Medium - Fat— Loin: Lean — Medium- Fat— Rump: Lean — Medium- Fat— Round: Lean — Medium- Fat— edible portion. as purchased, -edible portion. as purchased. . edible portion. as purchased. . ediljle portion. as jjurchased. . -edible portion. as purchased. . edible portion. as purchased. . edible portion. as purchased. . -edible portion. as jjurchased. . edible yjortion. as purchased. . edible portion. as purchased. . -edible portion. as purchased. . edible portion. as purchased. . edible portion. as purchased. . -edible portion. as purchased. . edible portion. as purchased . . 4 4 4 3 6 6 15 15 9 32 32 6 6 4 3 10 10 5 5 31 29 iS 14 5 3 19-5 15.2 14.7 22.6 20.8 i6!8 13-1 14.0 20.7 8.1 71-3 57-4 68.3 57-9 62.3 53-3 66.0 52.6 55-5 43-8 48.5 39-6 67.0 58.2 60.6 52-5 54-7 49-2 65-7 56.6 56.7 45 -o 47-1 36.2 70.0 64.4 65-5 60.7 60.4 54-0 20 .2 19- 16 -3 15- 19 .6 18. 16 .6 16. 18 •5 18. 15 9 15- 16 5 16. 15 2 14- 17 5 17- 13 9 13- 15 15- 12 7 12. 19 7 19. 17 I 16. 18 5 18. 16 I 15- 17 5 16. 15 7 15- 20 9 19. 19 I 17- 17 4 16. 13 8 13-' 16 8 16.. 12 9 12. 21 3 21. < 19. 5 19. 20. 3 19. J 19. 18. 19. 5 19. 17- 5 17- II 8.2 6.6 9 10. 1 18.8 15-9 9.8 9-3 26.6 20.2 17-5 27.6 24.8 13-7 11. 25-5 20.2 35-7 27.6 7-9 7-3 13.6 12.8 19-5 16. 1 0.8 0.9 C.8 0.9 0.7 0.8 0.7 0.9 0.7 0.7 0.6 i.o 0.9 1 .0 0.9 0.9 0.8 1.0 0.9 0.9 0.7 0.8 0.6 I.I 0.8 720 580 865 735 1135 965 790 67s 1450 "55 1780 1525 9C0 785 1 190 1040 1490 1305 965 820 1400 I no 1820 1405 730 670 950 895 1 185 1005 214 FOOD INSPECTION AND ANALYSIS. '^^jM^m ^^P^S^^^^'^ l.Neck 6. Ribs 2. Chuck 7 . Loin 3. Shoulder 8. Flank i. Fore shank 9. Leg 5. Breast 10. Hind shank Fig. 57. — Diagram Showing Cuts of Veal. COMPOSITION OF VEAL. Num- ber of Anal- yses. Refuse. Water. Protein. Fat. Ash. Fuel Value per Pound. Cals. Cut. NX 6.25. Bv Differ- ence. Chuck: Lean — edible portion . . as purchased . . . Medium — edible portion . . as purchased Ribs: Medium — edible portion . . as purchased Fat — edible portion . . as purchased Loin : Lean — edible portion . . as purchased Medium — edible portion.. as purchased . . . Fat — edible portion . . as purchased Leg: Lean — edible portion. . as purchased Medium — edible portion . . as purchased.. . I I 6 6 9 9 3 3 5 5 6 6 2 2 9 9 ID 9 19.0 18.9 25-3 24-3 22.0 ■^6:5' 9.1 14.2 76-3 61.8 73-3 59-5 72-7 54-3 60.9 46.2 73-3 57-1 69.0 57-6 61.6 50-4 73-5 66.8 70.0 60.1 20.6 16.7 19.2 15.6 20.1 15-0 18.8 14.2 19.9 15.6 19.2 16.0 18.5 15-I 21.2 19-3 19.8 16.9 1.9 1.6 6-5 5-2 6.1 4-6 19-3 14-5 5-6 4-4 10.8 9.0 18.9 15-4 4-1 3-7 9.0 7-9 1.2 0.9 I.O 0.8 I.I 0.8 1.0 0.8 1.2 0.9 I 0.9 1.0 0.8 1.2 I.I 1.2 0.9 465 380 640 515 640 480 1 160 875 615 480 825 690 1 145 935 570 520 755 620 19 16 20 15 18 14 20 15 19 16 18 15 21 19 20 15 7 7 5 7 2 4 9 9 6 7 3 3 4 2 5 FLESH FOODS. 215 0l(oi^,i///i- l.Neck 2. Chuck 3. Shoulder 4 . Flank 5 ■ Loin 6. Leg Fig. 58. — Diagram Showing Cuts of Mutton. COMPOSITION OF MUTTON -\ND LAMB. Num- ber of Anal- yses. Refuse. Water. Protein. Fat. -A.sh. Fuel Value per Pound, Cals. Cut. NX 6.25. By Difler- ence. Mutton. Chuck: Lean — edible portion . . as purchased. . . Medium — edible portion . . as purchased. . . Fat — edible portion . . as purchased . . . Loin: Medium — edible portion . . as purchased . . . Fat — edible portion. . as purchased Flank: Medium — edible portion . . as purchased Leg: Lean — edible portion . . as purchased Medium — edible portion. . as purchased Lamb. Chuck: edible portion . . as purchased . . . Leg: Medium — edible portion . . as purchased Fat — edible portion . . as purchased Loin: edible portion. . as purchased I I 6 6 2 2 13 12 3 3 8 2 3 3 II II I I 2 2 I I 4 4 19-5 21.3 ■^6:5' 16.0 II. 7 9.9 "I'e'.s "18.4 19. 1 17.4 13-4 14.8 64.7 52-1 50-9 39-9 40.6 33-8 50.2 42.0 43-3 38-3 46.2 39-0 67.4 56-1 62.8 51-2 56.2 45-5 63-9 52-9 54-6 47-3 53-1 45-3 17-8 14.3 15-I II. 9 13-9 II. 6 16.0 13-5 14.7 13.0 15.2 13-8 19.8 16.5 18.5 15-1 19. 1 15-4 19.2 15-9 18.3 15.8 18.7 16.0 18. 1 U-5 14.6 "-5 13-7 11-5 15-9 13.0 14.2 12.5 14.8 13.6 19. 1 15-9 18.2 14.9 19.2 15-5 18.5 15.2 17. 1 14.8 17.6 15.0 16.3 13-I 33-6 26.7 44-9 37-5 33--^ 28.3 41.7 36.8 38-3 36-9 12.4 10.3 18.0 14.7 23.6 19. 1 16.S 13-6 27.4 23-7 28.3 24.1 0.9 0.8 0.9 0.6 0.8 0.7 0.8 0.7 0.8 0.7 0.7 0.6 I.I 0.9 I.O 0.8 1.0 0.8 I.I 0.9 0.9 0.8 1.0 0.8 1020 820 1700 1350 2155 1800 1695 1445 203s 1795 1900 1815 890 740 1 105 900 1350 1090 1055 870 1495 129s 1540 1315 2l6 tOOD INSPECTION AND ANALYSIS. 1. Head. 2 Shoulder. 3. Back. 4. Middle cut. 5. Belly. Ham. 7. Ribs. 8. Loin. Fig. 59- — Diagram Showang Cuts of Pork. COMPOSITION OF PORK, POULTRY, AND GAME. Cut. Num- ber of Anal- yses. Refuse. Water. Protein. NX 6.25. By Differ- ence. Fat. Ash. Fuel Value per Pound Cals. Shoulder Loin : Lean — Ham: Fat- Lean — Fat— Pork. edible portion, as purchased . . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased . . Chicken: Fowl: Goose: Turkey: Quail: Poultry and Game. edible portion, as purchased . . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . as purchased. . 19 19 5 5 3 3 26 26 12.4 23-5 0.9 51-2 44-9 60.3 46.1 41.8 34-8 60.0 59-4 38-7 33-6 41.6 25-9 17.6 22.7 74 8 43 7 63 7 47 I 46 7 38 5 55 5 42 4 66 9 13-3 12.0 20.3 15-5 14-5 II. 9 25.0 24.8 12.4 10.7 21.=; 12.8 19-3 13-7 16.3 13-4 21 .1 16. 1 13.8 12.2 19.7 15 -I 13- 1 10.9 24-3 24.2 10.6 9.2 21.6 12.6 19.0 14.0 16.3 13-4 20.6 15-7 2-5 1-4 16.3 12.3 36.2 29.8 22.9 18.4 8.0 0.8 0.7 I.O 0.8 0.7 0.6 1-3 1-3 0.1 0-5 I.I 0.7 1.0 0.7 0.8 0.7 1.0 0.8 1-7 1690 1480 1180 900 2145 1790 1075 1060 2345 2035 295 I '"'4 5 775 1830 i5°S 1360 1075 775 FLESH FOODS. 217 Characteristics of Sound Meat. — The reaction of meat should be acid. If neutral or alkaline, decomposition is indicated, except that alkalinity may be due to the use of alkaline salts as preservatives. Letheby * gives the following characteristics of sound, fresh meat. In color it is neither pale pink nor deep purple, the former indicating that the animal was affected with some disease, and the latter that it died a natural death, and was not slaughtered. In appearance it is marbled, due to the presence of small veins of fat distributed among the muscles. In consistency it is firm and elastic to the touch, and should hardly moisten the finger; a wet, sodden, or flabby consistency with a jelly-like fat is indicative of bad meat. As to odor, it is practically free ; whatever odor there is should not be disagreeable ; a sickly or cadaverous smell is indica- tive of diseased meat. After standing for a day or so, it should not become wet, but on the contrary should grow drier. When dried at 100° C. it should not lose more than 70 to 74 per cent in weight; unsound meat frequently loses 80% or more. It should shrink very little in cooling. Inspection of Meat. — While carefully drawn laws exist almost every- where relating to the sale of meat, and government inspectors are ap- pointed to carry out the requirements of the laws, yet in this country there is undoubtedly some meat unfit for food on the market, owing to the small number of inspectors, and the consequent comparative safety with which unscrupulous dealers may sell meats forbidden by law and escape detection. The inspection of meats and fish under municipal ordinances is not always carried out as thoroughly as might be desired. Unwhole sameness 0} Meat may be due to a diseased condition of the animal while alive, or to poisonous or injurious toxins developed by the action of bacteria after death. In the first case, the diseased conditions may be due to temporary causes only, or to the presence of animal parasites, such as trichinae in pork, or as the result of pathogenic bacteria, causing such serious diseases as tuberculosis, anthrax, glanders, etc. It thus requires much skill and judgment on the part of the meat-inspector to correctly pass upon the suitability for food of the various meats as they appear on the market. CopHn and Be van f give in detail useful data regarding the inspection of meat, as well as of the animal before slaughtering, showing the requisite size, weight, age, conditions of health etc., that should obtain. The detailed physical and microscopical exami- nation involved in such inspection is, however, rarely germane to the work of the public food analyst, and will not be treated of in this manual. * Lectures on Food, p. 210. f Practical Hygiene, pp. 130-157. 2l8 FOOD INSPECTION yIND AN /I LYSIS. It is also beyond the scope of the present work to treat of the harmful toxins developed by bacterial action in meat and fish, causing what is known as ptomaine poisoning. The work of detecting and isolating such poisons comes within the province of the bacteriologist and biolo- gist, rather than that of the chemist, involving many experiments upon guinea-pigs, rabbits, or other animals not usually found in the chemist's laboratory. It has furthermore been recently shown by Vaughn and Novy * that even when these toxins are present in foods in sufficient quantity to produce serious results, very considerable amounts of the food must be taken in order to isolate them by chemical means, more, in fact, than is usually available for analysis. For the general inspection of meats for animal parasites, poisonous toxins, etc., the reader is referred to such works as those of Vaughn and Novy, Fischoder, Walley, Andrews, Cobbold, and Salmon as cited in the references on pages 258 to 260. U. S. Standards.! — Standard Meat is any sound, dressed, and properly prepared edible part of animals in good health at the time of slaughter. The term "animals" as herein used includes not only mammals, bui: fish, fowl, crustaceans, mollusks, and all other animals used as food. Standard Fresh Meat is meat from animals recently slaughtered, or preserved only by refrigeration. Standard Salted, Pickled, and Smoked Meats are unmixed meats pre- served by salt, sugar, vinegar, spices, or smoke, singly or in combination, whether in bulk or in packages. Standard Manufactured Meats are meats not included in the above divisions, whether simple or mixed, whole or comminuted, with or without the addition of salt, sugar, vinegar, spices, smoke, oils, or rendered fat, if they bear names descriptive of their composition, and when bearing such descriptive names, if force or flavoring meats are used, the kind and quantity thereof are made known. Preservation of Meat. — Raw meat soon begins to decompose, unless precautions are taken to destroy, or at least check the growth of putrefying bacteria. From earliest times the subjection of meat to extreme cold has been practiced in order to enhance its keeping qualities. Bacterial growth is inhibited to a greater or less extent by refrigeration, by sub- jecting the meat to the various processes of curing, by the use of high temperatures and the exclusion of air as in canning, and by the employ- ment of antiseptics. * Cellular Toxines. t U. S. Dept. of Agric, Off. of Sec, Circ. No. 19. FLESH FOODS. 219 Refrigeration may consist (i) in actually freezing the meat^ in which condition it may be kept without decomposition almost indefinitely, until finally thawed for use, or (2) in keeping the meat at or near the temperature of freezing without actually congealing it, as is done by the use of the ordinary refrigerator. The second method, while much less efficacious than the first, serves to prevent decomposition for a considerable time and is preferred for beef, mutton, and pork. The lower temperatures are employed with poultry and game. Curing consists in subjecting the meat to various processes of drying, smoking, pickhng, corning, etc., or to a combination of these processes. In simple drying, the meat is subjected to the heat of the sun or to artificial heat. In smoking, which is commonly practiced on beef and ham, the meat, which may.or may not be first salted or otherwise treated, is exposed to the smoke of the burning beech or hickory wood, thus becoming impregnated with the antiseptic properties of the creasote and pyroligenous acid, at the same time being dried by the heat. Treatment with crude pyroligenous acid, instead of smoking, is also commonly practiced. In some cases best results are obtained by a slow smoking at a comparatively low temperature, while in others quick, hot smoking is found most efficacious. The character of the meat is decidedly changed by smoking, and, according to Utescher, smoked meat is always alkaline in reaction. In pickling, the meat may be treated with dry salt and subjected to pressure, so that the meat juice forms the liquid for the brine, in which it is allowed to remain for some time ; or, as in the ordinary process of comings the beef is soaked for some days in a strong solution of salt to which a httle saltpetre (KNO3) has been added. In the process of pickling, the salts from the brine slowly diffuse into the interior of the meat by osmosis, a part of the soluble albumin passing out into the brine. The effect of the saltpetre is to preserve the natural red color of the meat, which by the action of salt alone becomes destroyed, or at least impaired. Bacon and ham are frequently cured by pickling in brine containing salt, saltpetre, and cane sugar, and sometimes also such antiseptics as boric acid and calcium bisulphite. The curing of bacon is sometimes effected by injecting the pickling fluid into the tissues with a " pickle-pump," capable of exerting a pressure of 40 lbs. to the square inch, and provided with a hollow, perforated need' '"-nozzle, which penetrates the flesh. After pickling, the bacon or ham 2 20 FOOD INSPECTION ^ND J N^ LYSIS. may be simply dried, or, if desired, smoked. Oak sawdust is frequently burned for the smoking of ham. The Use of Antiseptics in Meat. — Most of what might be termed the modern preservatives are to be looked for in one or another of the various meat preparations, though some are better adapted than others for use in particular cases, as will be seen by reference to the composition of typical commercial preservative mixtures given on page 823. Borax and boric acid, usually in mixture, have been used more com- monly than any other preservatives for the preservation of meat. Like salt, they are used commonly in surface application, in the case of large cuts of meat, or by mixing, in the case of sausage meat. A more recent method of application consists in impregnating the tissue of the meat with a solution of the boric mixture, by means of the above-described pickle-pump. The use of boric acid and its compounds, however, is not permitted under the regulations of the Federal meat inspection law of the United States and Germany. Sulphurous Acid. — As much as 1% of a solution of sulphurous acid may be added to meat without being apparent to the taste or smell. Mitchell quotes Fischer as having found that 50% of the preserved meat products (sausages, etc.) sold in Breslau in 1895 contained sulphites, varying in amount from o.oi to 0.34 per cent of sulphur dioxide. Calcium bisulphite is a salt commonly employed. In Hamburg steak it serves partly as a preservative, but chiefly as a deodorizer and a restorer of the bright red color of fresh meat. Salicylic Acid is not of such common occurrence in meat products as the other antiseptics mentioned. The writer has found it in prepared mince-meat. Among other preservative substances sometimes used with meat are solutions containing phosphoric acid and aluminum salts. The toxic effects of these and other antiseptic chemicals in meats, and the most practical means of controlling their use are questions in con- troversy, presenting no new phases that have not been elsewhere dis- cussed in treating of the general question of preservatives in food. Methods of detecting preservatives in meats are given elsewhere. Effect of Cooking on Meat. — The general result of cooking is to render the meat less tough, to develop an agreeable flavor, and to coagulate more or less of the proteins. When subjected to moist heat, such as boil- ing and steaming, some of the soluble materials are dissolved, so that when the liquor in which the meat is boiled is thrown away, some of the FLESH FOODS. 22 1 valuable substances are lost. This is especially true when meat is placed in cold water which is afterwards brought to boiling, a method to be recommended when the liquor with the dissolved extractives is to be used for broth. When the meat to be boiled is placed at once in boiling water, there is less loss of soluble matter by reason of the formation of a more or less impenetrable co:,ting on the outside, by the coagulation of the proteins. Meat that is boiled becomes softer, owing to a partial dissolving of the gelatin formed. In the dry cooking of meat, as by broiling or roasting, there is usually a hardening of the tissues, and a driving out of some of the meat juices, which are, however, often recovered in the form of gravies. Canning of Meat. — By far the most effective method of preserving meat and meat preparations of all kinds for long periods of time, consists in the application of the principle of sterilizing by heat, and sealing in air-tight -cans. The process of canning cooked meat and its products does not differ materially from that employed in the similar preparation of vegetables. (See Chapter XXL) Previous to canning, the meats are usually cooked by boiling, during which process the changes described in the preceding paragraph take place. The practice of misbranding chopped meat with respect to variety has been very prevalent in the past, and many varieties of so-called potted and devilled meats and game have frequently consisted wholly or in large part of a cheaper variety than that specified on the label. This practice has been largely corrected in this country, owing to the enforcement of the regulations of the Federal meat inspection law. It is largely among the canned meats and prepared meat products that instances of adulteration are to be found, since the fresh meats in whole cuts are rarely subject to adulteration. Preservatives are sometimes added to canned meats, especially in the case of dried and smoked beef, ham and bacon, and in the potted and devilled mixtures. Boric acid, benzoic acid, and sulphites have been found in these preparations. It is believed, however, that this practice has been largely discontinued, owing to the enforcement of the Federal regulations mentioned above. Composition of Canned Meats. — The following table, compiled from results published by Bigelow and others,* shows the composition of various of the most common canned and preserved meats and meat * U. S. Dept. of Agric, Bur. of Chem., Bulletin 13, part 10. 222 FOOD INSPECTION AND ANALYSIS. 3 O (U O M o ""'""' O ro^ iJ-)0 <^ M o O o <^C0 oON-t'^Oi-io'-i^'^OOO OOi-.Oc^Of^-*c-iOnt^OO>-iiot^i-iCNT}-OOOi-MWOwrI-d H H "H h vO rOOO 00 i-i lO OOO t^ 1-1 O oo M t^ <^00 OcO^-^^^oOO^>-loO>-|H<^0'^r~-ro-iOioOO fOO Oi-inOcsrOMMvOi-i ChiowoOi-iMwt^MfOP)O^Owt^r^i-i'OrOvoNi-i'^ -On triMO t^ H N w \0 O Lo f) O M ^vO O O lO t^OO ^tO rowNNNOO'd- -POO lO^ r^ m MMWMroOwi-iOM'^'-ii-i'^OMrtOi-ioiOOM ■HNOO"0 M O r^O^ioO ^ • O •+u^moO O M i/^OO lOM voO row ONfOrON PI t^MO romo m fOr^ -O "^r^ojoo m wMO'^r^i-iM'^iHOnOMCNOi-i'+Oi-iroOi-''* -MNOi-HroO 00 "^ O O 'too r-~0 M M o N roO m\0 CnOn^O OO mvO a>00 r^ lOOC O t>.iO0) CAroroOOO ^O^OoO loroOO^MDO O O OOO O rOw lO^Ol^ro li^ U-) Tt O r^ .M O M l-lMI-t»-lClMC»-0 CM ■*0 '-t-vO M N Tj-O dddoi-ioooooHoowOOMOooooooooocco On ■* ■* «~~0 ■>* N ro O lO t^^o GnONO'^nOhoOMMNOi-iOOnnO^N'^- MOiMU->i-i«coiONi-(fOO«'*2MOt^OO'^CNt-~.iHOrr>MMvOO ddddModooooooooooooooooooooooo w N « On t-~oO oOf^wNMOr>-r^ <^oO lo w o o -O w-j lo t^MO to O « O oo ■^lOrOO 'tONiorOO o 0^<^'^ONrOtr)t>-ONiOP) t^O ■* t^oO ro N 00 CO r<^ OMC)rOTj-i-iHNrt-MHroO M c^fOvOM M\0 OP) w OnO w O rOH00t^HioONfr)'-P<'*0i-iO>-ii-iO0i-iO\0tOMMN0i-iN0M00io fOrO c^ rONO M rorON rOVOPl roiO" M rOO r> (VN On OnOO Os <-000 rONO I^OnmnO TfM t^»t<^0^^0 m . On O 00 rO u- P) loONroi-i low ioiOM OnG ONt^ ss a; 5 ^.S g ^ £ g ^ S g ^ E g S.S ^ rt.5 g. ^ jO r^ rO O ^ -d -d T3 rc T3 lU c S ^ d u u u Ph u u u u FLESH FOODS. 223 products, and in one or two instances fresh meat has been included for comparison. Sausages. — Nature and Composition. — Sausages are made from finely- chopped meat, highly seasoned with various spices, and, as usually sold, stuffed into casings made of tlie cleaned and prepared intestine-skin of cattle, sheep, or hogs. The meat most commonly used is pork. Sau- sages are frequently home-made, especially in farm communities, the cliopped and seasoned meat being stuffed in cloth bags instead of casings. Any and all kinds of meat are used in sausages, and much that is undesirable and even unwholesome, is undoubtedly most readily used up in this product. There is little doubt that horse meat occasionally gets into the hands of the marketmen to be worked up in the form of sausages mixed with other meat. The condition in respect to these matters has been greatly improved, however, by the increased vigilance of State and Federal authorities. Sausages are sometimes artificially colored, and in some cases contain so-called " fillers " in the nature of dried bread, corn meal, potato starch, crackers, waste biscuit, boiled rice, etc. CHEMICAL COMPOSITION OF SAUSAGES.* No. of Analy- ses. Ref- use. Water. Protein. Fat. Total Carbo- hy- drates. Ash. Kind. NX6.25 By Differ- ence. Value. Cals, Farmer: edible portion. . . as purchased Pork : as purchased Bologna: edible portion .. . as purchased Frankfort : as purchased. - - I I II 8 4 8 3-9 23.2 22.2 .39-8 60.0 55-2 57-2 29.0 27.9 13.0 18.7 1S.2 19.6 27.2 26.2 12.7 18.4 18.0 19.7 42.0 40.4 44-2 17.6 19.7 18.6 I.I 0-3 I.I 7-6 7-3 2.2 3-7 3-8 3-4 2310 2225 2125 109s 1170 1 170 * U. S Dept of Agric, Off. of Exp. Stations, Bui. 28 (Revised Ed.). Adulteration of Sausages with Starchy Materials and Water. — Robison, who has made a special study of these forms of adulteration at the Michigan Dairy and Food Department, states as follows:* " Lean meat carefully chopped has an enormous combining power and can be made to take up a great quantity of water. Frankfurts, bologna, and pork sausage have been found to be adulterated with from 0.5 to 5% of starch, indicating an addition of approximately i to 10% of so-called cereal (chiefly corn flour), and from 5 to 40% of water in addition to * Personal communication. 224 FOOD INSPECTION AND ANALYSIS. that contained in the meats when in their fresh condition. The main excuse for the use of water is that it renders the meat of such a consistency that it may be easily stuffed into thin cases, such as are usually used for sausages that are eaten without removing the casing. As a matter of fact, this addition is not necessary where fresh meats are used, nor with those cuts of meat which the American public is in the habit of using in the manufacture of sausages in the home. Without doubt, in sausages composed of ox hearts, ears, snouts, hps, etc., in considerable quantities, the addition of water may facilitate the stuffing into thin casings. " Starch hastens and increases the absorbing or combining power of lean meat. In many instances where inferior products, such as ears, etc., are used, virtually it is the only absorbing agent present in the product. It then serves a two-fold purpose, first, giving an absorbing power to meat which it has not, or inflating the absorbing power of a meat which natur- ally is deficient in this respect, and second, acting as a skeleton or frame- work, thereby disguising shrinkage during the process of cooking. Generally, added water and cereal are evidences of inferiority, and they are by no means infrequently added with the very purpose of concealing such inferiority. " The evidence of adulteration with water is the discrepancy in the ratio of the water to the protein in the sausage.- This ratio in sausage made from the fresh carcass varies from 3:1 to 3.6:1, being on an average about 3.35:1." Artificial Coloring Matter in Sausages. — Owing to the rapid color changes which freshly chopped meat, especially beef and mutton, natu- rally undergo, it is a common practice to employ powdered niter or salt- peter. Treated in this manner, meat remains pink, owing to the action on the haemoglobin of the oxides of nitrogen resulting from the nitrate. As much as 4 ounces of niter to 100 lbs. of meat is sometimes used. A larger quantity would result in a shriveled appearance. The use of artificial colors has been common in the past, in order to permanently dye the flesh a bright red, similar to the tint which the oxy-haemoglobin naturally imparts to the beef when fresh. A variety of colors have been employed for this purpose, such as red ocher, coal-tar dyes, cochineal, etc. They were sometimes used in admixture with preservatives. Their use has been largely discontinued in this country, owing to the enforcement of the regulations under the Federal meat inspeciton law. FLESH FOODS. 225 ANALYTICAL METHODS. In analyzing meats and meat products due regard must be paid to their perishable nature, and, for this reason, immediately after their receipt by the analyst the various determinations should be promptly begun and rapidly carried out. If delays are absolutely necessary, the samples, as well as some of the solutions, especially during the earher course of the analysis, should be kept on ice to prevent decomposition. Even at low temperatures, however, both bacterial and enzymic decom- position occur, and the nature of the proteins is slowly changed. Refuse material, such as bones, skin, gristle, tendons, etc., are separated as completely as possible by means of a knife from the edible portion, and the latter, cut first into small pieces, is passed repeatedly through a sausage- machine or ordinary household meat-chopper, in order to reduce to a homogeneous, finely divided mass. Determination of Water. — From i to 3 grams of the finely divided material are weighed in a tared platinum dish, and dried to minimum weight at a temperature of 100° C, in an air-oven. A slight oxidation of the fat may introduce a trifling error, but, excepting for the most exact work, where the drying should be accomplished in an atmosphere of hydrogen, or in vacuo, the above method is sufficiently close. Determination of Water in Sausages. — Rohison's Method. — A large sample (100 to 500 grams) is put through a food-chopper, weighed on a large porcelain plate, and allowed to dry at 70 to 90° C. A steam radiator may be conveniently used for this purpose. After drying 10 to 12 hours, or over night, it is reweighed and finely ground in a small laboratory mill. If the sample is quite fat, the prehminary drying of the chopped meat may be carried out conveniently on a sieve, which will permit the fat to drain through onto a plate below, thereby making more simple and accurate the sampling and mixing. The fat thus removed should be separately weighed and dried. If the sample is quite lean, the final drying of 2 to 5 grams of the air-dried sample may be made at 100° C. in an ordinary water or electric oven. If it is quite fat, it is best to conduct this drying in a current of hydrogen. Determination of Ash. — Incinerate the residue from the total solids in the original dish at a low red heat. It is usually advantageous, especially in the case of salt meat, to exhaust the charred sample with water, collect the insoluble residue on a filter and ignite. The filtrate is then added, evaporated to dryness, and the whole heated to low redness and weighed. A perfectly white ash is difficult to obtain. 226 FOOD INSPECTION AND ANALYSIS. Determination of Fat. — Extraction Method. — Dry 2 grams of the sample at 100° and extract with anhydrous ether for sixteen hours as in the case of cereal products (p. 277). More complete extraction is obtained by grinding the residue in a mortar and repeating the process and still more complete by digestion with pepsin and intermittent treatment with the fat solvent but this latter is both tedious and open to other errors. Kita's Centrifugal Method."^ — Treat 2.5 grams of meat in a Babcock milk flask with 8 cc. of i : i H2SO4 (or 5 grams with 17 cc.) and heat in a water-bath to 60-70° with occasional agitation till the proteins dissolve. Add I cc. of amyl alcohol and sufficient dilute H2SO4 to bring the layer of fat within the neck. Whirl in a centrifuge for from 3 to 5 minutes and read the amount of fat on the scale. Amyl alcohol is usually necessary for complete separation and a clear fat layer. Examination of Fat. — Shake a large portion of the original finely divided sample in a corked flask with petroleum ether boiling below 60° C, and digest for some hours. Pour off the solvent, remove most of the petroleum ether by distfllation, and the last traces by allowing to stand in a vacuum desiccator over freshly ignited calcium chloride. Determine the usual constants as described in Chapter XIII. In minced prepara- tions these constants furnish a possible clue to the variety of meat used. Determination of Acidity of Fat. — Pennington and Hepburn Method.^ Weigh 10 grams of the fat, mechanically separated and ground in a meat chopper, directly into a 250 cc. Erlenmeyer flask, add 50 cc. of neutral alcohol, and phenolphthalein as indicator, and bring to a brisk boil. The hot alcohol dissolves the fat. Titrate immediately with tenth normal sodium hydroxide, shaking vigorously, until a pink color appears, which persists for one-quarter of a minute. Calculate the acid value from the amount of sodium hydroxide used, or the free oleic acid by multiplying the acid value by 0.503. Determination of Total Nitrogenous Substance. — Determine nitrogen in 2 grams of the sample by the Gunning or Kjeldahl method (p. 69) and multiply by 6.25. Although nitrogenous substances other than proteins are present and the factors for the individual proteins vary, this result is a fairly close approximation to the total nitrogenous substance present. The factors for meat bases are give on page 252. Determination of Ammoniacal Nitrogen. — Folin Method modified by Pennington and Greenlee. | — The ammonia, set free by sodium carbonate, i_ * Arch. f. Hyg. 51, p. 165. t Jour. Amer. Chem. Soc, 32, 1910, p. 568, % Ibid, p. 561, FLESH FOODS. 227 ■§-Sd 00 M 10 On 10 01 Tl- 1000 00 10 •* ^t On 000 l/-;\0' "O NO l^ 10 On NO NO M CO On t^NO (N 10 01 00 000 «^k' ro ro ro CO CO CO ^ 10 •* x^ Tf CO CO ^ CO Tj- LO 00 ■* Tt- "i- a ■ -+ t^ r- „ t^ ^00 M M CO 00 00 On NO 00 LO ^■§1 ui tN On CO 10 10 CO >* M CO 10 -+ On t^ - CO 10 W NO M -^00 T: Tt •^ CO ^ ^ CO CO Tl- CO 0< CO CN CO M 00 Tt 0< CO 00 M CO "* 01 S^^ M-i On w CO " On r^ On On CO cs 10 looo NO 00 t^ CO t^ T^ On ^i^o- M C<) t^ M CO CN '^ On t^NO M « rroo 01 t^ J-^ CO r^ On NO NO LO NO NC NC 10 NO t^NO NO NO 10 NO NO 10 NO NO LO OJti^ G lO ^ »*■ ^ -* "+ "+ •* Tt ^ ^ >+ Tt- -* •* Tf -* ^ 't '^ •* n- M- •^ t T3 Qj 0^ £«- H M M M M M M H M M M W M HI M M W H M M M M HI M 00 10 00 ON t— cs u-) CO to 0» ■* LO ■* Lo ur 10 10 >0 VO NO l^ 10 10 10 Tj- LO 10 rj- LONO Tj- LONO -^ Qm^i^ nO CN On M On LO "^ 10 01 00 On On 0^ 0^ On « 00 00 NO On «^ On 1-1 00 On 01 t^ Spec Gra^ 10 10 00 0-00 00 00 00 On OnOO 00 0-00 00 OnoO 00 OnOO 00 OnOO 000 000 000 000 000 : E s • c fi E F i p* : s g : s s : 2 g : £ g OJ P 3 :3 -1 a r- a s s E bX) Ne ^sg ^Sg ^sg fed 0. > < E re a; < ^3 CI c. j •ppV ouoqd -soqj 0IUB3J0UJ PPV ouoqd -sbq^j diubSjq r^ r*; r/; f*5 ro TT ^00 O r^ OOO O O O t^ O 00 OvoO 0\ irjvO o o o o o o r* OS r»»o *0 so vO 00 00 U-. ■^ nO ■^ 0\\0 0^ « 00 o o o o o o "PPV ouoqdsoqj [bjoj^ ■qsy ui 3puoiq3 lump -6g SB 9uu6iq3 ■qsv 1B50X •ajnjsioi^ ^ r^ IT) « I 1/100 re ro (ii 3.2 E.-S ^ <« O O h :z; w D h H CO •^ O u O W o o Pi H noO n l-sO t Biuouiiuy "uiqjuBx puB 'uiunBajQ ■ui5B3a3 uBqj jaqiO sasBQ iBaj^ •sasBg ujqiuBX UIUIJBajQ ptiB ui;Baj3 1/^ o O M \0 t^ r^ Osoo r^oo ■sasBg iBaj^ I^iox •s3uo;d3(j •saso9}ojj ■up^ojfj 9iqBih3B03 puB aiqnjosuj •BIUOIUUJY uiq^uBX pUB 'UIUpB3J3 'upB3J3 UBq; jsqiO sasBg ib3j^ •S3SBg uiqjuBx •U1UIJB3J3 pilB' Up'E3J3 •S3SBg ;b3pi iBiox r^ M 00 M 0\ CO o o o o o o ^00 t^vO vO r^ N N 00 O -"f M Os 0\ O re ■s3uo;d3j •sasoa^ojcj ■upi -oj(j 3]qBin3Bb3 puB siqnjosuj ^•SUI3iOJJ JB^OX ONO M 00 'O o\ ■a-5 g-25 6 FLESH FOODS. 243 ■pauiuii3i3puQ •;3BJixa jaxiig •Btuouiuiv uiqiUBX puB uiui^BajQ u-eqi jamo sasBg ;b3j^ sasEg uiq^uBX •uiuij-BajQ pUB UlJ^ajQ •sasBg ;b3pi jb?ox •sauo^dDfj •S3S03J0JJ 3iqBin3B03 puB aiqnjosuj uaSoi^i^j JBjox ■pioy opoBq sy uibjS jad oD 'appcojpAjj uinipog oi/jvi -soqj OtUBSjOUI PPV oijoqd -sbq^j otuBgJO ■ppV Duondsoqj iBjox ■qsy ui 3puo]H3 uinip -6g SB auu6iq3 •qsv IBiox ■ajrusTopj 0000000 0000000 0000000 0000000 r^ ^ r- r^ 'too O* 0000000 0000000 0000000 (^ c*^ c^ r*^ PO < fO f^ t T ^ < O »r)^ fO O OvOO « 00\O 0000000 fO fT) f*^ (S O O I^vO O ^^O vO f*^ n rr rt Tj- C> f*^ t^ -00 "O O ^O Ov ■5 (D^H, 6 0; oj a: ■aw _._3 2 n!:_ o- 5 u •s u Oh [3 h w I < o in S p c ij- 0.10 lO lO 01 i M •Biuouimv 00 ro M « O-O rO fO-O r- f: V) u^ i/i 2 ■ •UtHJUBX pUB 'uiupBajQ 00 -a- t M- to N >0 ^ 'UXJB3J3 UBqj -0 ^ t 1/1 vr> -"tvo jaqjo sasBg ;e3j^ rO 't -^ fO -^ N « t^ \ri (^ 0\ y* PO (^ N W t«5 00 fO •sasBg uiq;uBX 00 00 (^ t M C< PfJ r^ in Tf >/1 N 0\ •UIUIJB9J3 r^ N ^ t N r- r- puB ui;b3J3 PCOO M N <^ 13 M K< 11 N IH l-( 5i in in 00 t^-O (U •sasBg ^B^I^[ iBiox 00 »^ « -O N a in>c in>o ^ f - 'T « 10 r^^O t M w ot ■sasBg uiq^uBx 0000000 Or-. 01 VO H. ^ ■UlU!iB3J3 ►HOO m m moo •a m puB u:iBaJ3 " " " N " 00 Ol in " Ttio 3 •sasBg iBaj^ jb^ox m in*0 lO 00 ^ ro a 00 t M PTJiO lO Ol li sauo^daj m Oioo m in-o ^ ■^ « Tt Tf N m in 2; p^ r<5 f^ " 00 m t •sasoaiOj(j M "O NO fi fO r-- Ol N t m « M ma^ moo Ol wiO ■«■ -ojj 9iqBin3B03 Noo M 00 Ol m puB aiqniosuj M M " " 10 m r> m m po r- TTio r- « t- *SUPJOJd JBIOX lO in r- CO X w X W >. (P Da •d 0. 0) ■3 ►-1 3.4- CO fe IUT-! ■u.-"=.£-v--:>fe fe 11 > c < 3£ 3 0" 244 FOOD INSPECTION AND ANALYSIS. by means of enzymes or otherwise, and contain not less than 90% of proteoses and peptones, 7. Gelatin {edible gelatin) is a purified, dried, inodorous product of the hydrolysis, by treatment with boiling water, of certain tissues, as skin, ligaments, and bones, from sound animals, and contains not more than 2% of ash and not less than 15% of nitrogen. ANALYSES OF MEAT EXTRACTS. — Largely by the application of the above standards, Bigelow and Cook* have classified a number of products of this class as solid (pasty) meat extracts, fluid meat extracts, and " mis- cellaneous preparations." Their results are given on pages 242, 243, 247, and 248. Solid and Fluid Meat Extracts. — It will be noted that the solid and fluid extracts are identical, except that the latter are concentrated only half as much as the former. Allenf holds that the maximum chlorine content of meat extract calculated to sodium chloride is 0.06% for every unit of dry solid matter, and that excess over that amount is due to added common salt. This opinion is based on the composition of South Ameri- can extracts prepared from the meat of the entire carcass. Streett con- siders that the maximum standard of 12% is too high, and encourages the manufacturer to add salt to his product. In this country, however, extracts are commonly prepared in part by the evaporation of the soup liquor in which meat is parboiled before canning, § and in part from trim- mings. It is claimed that the natural salt content of the product made in this manner is higher than when the entire meat of the carcass is employed. A second grade article is also made from bones, trimmings, etc., and contains a still higher percentage of sodium chloride. This product is designated as "bone extract" in the standards given on page 241. The presence of an excessive amount of sodium chloride is usually due, probably, to the presence of the product last mentioned, or to the use of corned beef in the preparation of the substance. In the latter case nitrates are generally present. On comparing the analyses given above with the composition of other products of this class, as contained in the following tables, the value of the percentage of meat bases, es- pecially of creatin and creatinin, in distinguishing meat extracts from meat juices and manufactured products of that general type is apparent. * U. S. Dept. of Agric, Bur. of Chem., Bui. 114. t Commercial Organic Analysis, 3 Ed., Vol. IV, p. 307. % Conn. Expt. Station, Report for 1907 and 1908, p. 622. § Bigelow and Cook, U. S. Dept. of Agric, Bur. of Chem. Bui. 13, pt. 10, p. 1389. Bigelow and Cook, U. S. Dept. of Agric, Bur. of Chem., Bui. 114, p. 13. FLESH FOODS. 245 Meat Juices Prepared in the Laboratory. — For the purpose of comparison with meat extracts, the following analyses of meat juices prepared in the laboratory are of interest. MEAT JUICES PREPARED IN LABORATORY.* Composition of Sample. Preparation of Juice. Round beef, cold pressed Chuck beef, cold pressed Round beef pressed at 60° C Chuck beef pressed at 60° C Juice from beef chuck at 60° C Juice pressed from sirloin steak and water. Juice extracted from sirloin steak by cold pressure Juice extracted from beef chuck by cold pressure ... .'. Juice extracted from beef chuck by cold pressure after 6 hours at 6o°-ioo° C Water in Juice. 85.76 86.85 90.65 91 .90 89.56 91 . 10 96. 13 96.58 98.11 Ash. I -53 1.86 1.36 I . 29 1.27 I . 40 o . 46 0.43 0.39 Chlorine as Sodium Chloride in Ash. 0.19 0.16 0.12 0.05 0.0s 0.05 Phos- phoric Acid (P2O5). 0.37 0.31 0.36 o . 29 0.37 o. 18 0.14 O. I I 0.12 Ether Extract. •30 •19 ■ 64 Acidity as Lactic Acid. 0.27 0.32 0.15 Composition of Sample. Preparation of Juice. Total Nitro gen. Insolu- ble Nitro- gen. Coag- ulable Nitro- gen. Pro- teose Nitro- gen. Pep- tone Nitro- gen Amido Nitro- gen. Unde- ter- mined Matter. Round beef, cold pressed Chuck beef, cold pressed Round beef pressed at 60° C Chuck beef pressed at 60° C Juice from beef chuck at 60° C Juice pressed from sirloin steak and water. . Juice extracted from sirloin steak by cold • pressure Juice extracted from beef chuck by cold pressure Juice extracted from beef chuck by cold pressure after 6 hours at 6o°-ioo° C 2.08 1.74 1.16 0.48 0.43 o . 24 0.16 1.37 0.29 o. 98 0.68 0.12 I 0.41 0.49 OS4 0.34 0.34 0.00 0.06 0.07 o .04 0.07 o . 42 O. 20 trace trace trace 0.16 o. 18 none none 0.12 ■33 .29 o .09 0.08 0.47 I 03 1 .90 0.40 2 . 92 0.94 0.8s 0.59 0.25 Preparation of Juice. Round beef, cold pressed Chuck beef, cold pressed Round beef pressed at 60° C. . . Chuck beef pressed at 60° C. . . Juice from beef chuck at 60" C. Juice pressed from sirloin steak and water Juice extracted from sirloin steak by cold pressure Juice extracted from beef chuck by cold pressure Juice extracted from beef chuck by cold pressure after . 6 hours at 6o°-ioo° C Results in Terms of Total Nitrogen. Insol- uble Pro- tein. Coag- ulable Pro- tein. 7.69 65.87 16 . 66 56 . 32 58.62 1 1 .oi| 37.61 44.95 45.76 70.83 Albu- moses 4 . 02 3-45 6 . 42 38.53 16.95 Pep- tones 7.69 6. 0.86 19. 26 Amido Bodies 15-87 16.66 37.07 24-77 16.51 22.03 29-17 Nitrogenous Bodies. Insol- uble Pro- tein. Coag- ulable Pro- tein. 1 .00 8. 56 81 6.13 4-25 751 2.56 3-06 3-38 2-13 Pro- teoses, 0.38 0.44 0.25 0.44 2.63 1-25 trace Pep- tones. 1-13 none Amido Bodies 1-03 o . 90 I -34 0.84 0.56 o.8r 0.44 0.28 0.25 * Bigelowand Cook, U. S. Dept, of Agric, Bui. 114, p. 19. 246 FOOD INSTECTION AND ANALYSIS. The composition of these products is widely different from that of the so-called meat juices of commerce, as given in the table on page 247. It appears to be impracticable to so preserve a true meat juice that it can become an article of commerce. Misceilaneous Meat Preparations. — There is on the market a wide variety of manufactured products intended to replace beef juice. Some of these have meat extract as a base, and some have an addition of a small amount of albumin, or some form of soluble protein. Others consist largely of albumoses and peptones, and are formed by the action of steam or of acid and pepsin on meat. The tables on pages 247 and 248 give the composition of a number of products of this nature. The preparations given in the table on page 248 are arranged in four classes, according to their content of proteoses and peptones, meat bases, creatin, and insoluble proteins. Yeast Extract. — During recent years a product closely resembling meat extract has been prepared by the evaporation of the water extract of yeast. This product has been sold as a substitute for meat extract and has been reported in Germany as an adulterant therefor. The best means of distinguishing yeast extract from meat extract is by the deter- mination of creatin and creatinin, which are absent in the former.* Wintgent has pointed out that the filtrate .. from the zinc sulphate precipitate obtained in the determination of albumoses is clear in the case of meat extracts, but turbid if a considerable percentage of yeast extract be present. METHODS OF ANALYSIS. Water. — Water is best estimated by weighing from 2 to 3 grams of the preparation (if of the dry or pasty variety), or from 5 to 10 grams of the fluid extract, into a large platinum dish, the dry variety being dissolved in a little hot water. The powdered preparations are dried directly without admixture. To pasty and fluid preparations are added sufficient ignited asbestos, pumice stone or sand, sifted free from dust, to absorb the solution. Pasty preparations are first dissolved in sufficient water to make them distinctly fluid. The sample is then dried at 100° C. till it ceases to lose weight. Tin or lead dishes or Hoffmeister glass dishes may be employed, and after being cut or broken, placed in the extraction tube for the determination of fat. * Micko, Zeits. Unters. Nahr. Genuss., 5, 1902, p. 193; 6, 1903, p. 781. t Arch. Pharm., 242, 1904, p. 537. FLESH FOODS. 247 H < (A H X W H •pamuijaiapuf^ •^OBJixg JSina •Biuouiuiy O 000 ui<3 o 00 M 0000 00000000 \0*0 0^>-t ror^l'l*-' nsO r^ « O O OONi-NNO"OinNO-00 000000000000000000 u-Bn'j -iamo sasBq iBaj^ ■sasBQ uiq^uBX UtUIJBajQ puB uij-BajQ •sasBg iB3i\[ ib;ox ■sauojdaj •sasoajojj uia^ojfj aiqBj -n3B03 puB aiqnjosuj ■ua3oj;i^ l^^ox -. M o o o ■ 000000000000000000 00000000 uosO VI -" O « o o o o \\0 O '-' M r^ -^o (hO^oOOT^ni/^ OOr^MMWHIMOOOOOOO 00 C» (N "i- IT) u^ r^ M o 00 co^O •ppY apaB"^ sy ui-Bjg aad '03 "apixoapXfi uiriipog oi/f^ ■ppv auoqdsoqjj oiubSjouj •ppv ouoqdsoqcj oiubSjq PPV ouoqdsoqtj \ViOj^ •qsy ux apuo]q3 lunipog SB auuo[q3 •qsy JB^ox •ja;BjVi. OO-'OOOOO w m i-i O ^ ( 0000000 00000 o\ o « O N 'T OvOO 00 O O ' fO r^ f^ inoo O f^ f^ ^ ^00 o r^ ro t^ O •-• M l/>sO '-' 00 T -^ lO'^-^MOOI^MOOwroO J vo ON l^vO ^00 »o O ^ <^ 0\ ■* ■ 5o O tJ- 0) a> ca'C ID 0) : o s oi - u c rt WJ . BO I-) >48 FOOD INSPECTION AND ANALYSIS. O i O CO 00 f^CO >■ ■. CO C « O r Pi M CO 1 rn t^ w^QO t^ ^O r^ O i-~ f-^oO 1 Si, •BIUOUIUIV ■ ■ S N N re fj « C* trOPOO ^C 4 On CO M fO 2: •^ -^ t^ « woOrr)OOOi^r^r-. r-d\ OoOwi/i ] 'UIUl^Baj^ 'UIlBSiQ t^ cs 0^ Tf inr^N roon poc 4 CO P* r^ O M 00 f2 UBij} Jaqio sasBQ iBaj^ « N P. N TJ-H, « M M -O ^ M M PI O i^ -^00 OOMt-^^f^r^ror*^ vO^O 0o C P< H COP.*^^ ■^ T O 00 u^o^^^^^'- -^u 1 lO P CO -Ntoo r^ -T r^OO 1/1 rO -^ OOO "^00 OOfO t^'^ \Ol--«'^ j u sasEg iBaj^ i^ioj. r^ -^T r^ PO « m f*>oo O fo M ^ I-. u 1 Tf CO Pi On a W "5 f*^ fO fO NO T PI M « O f^O fONNOOTj-rj-r* \or M 0."1 ■ 1 a i»l r^ fO-O t^mii^'tro (-"OO vONOs 1 S sauoidaj ON M t^ ■rr moo 0\ N '^ « so f 1 vO 1/ ■1 IOnO -t T3 O " " '^" rowrofO^ Nt- PO MM O Ov fOOO ■^SO OOO M ^ K- fV CO On CO i/loO *T 1 rroo 000 M-^O^-f^Ot^ -^CO oOnOOOm I 3 •sasoa;jO(£ TT o »A\0 t-t^MsOsO « ^ lO K NO lil M PI c M t^ " ^ P) PJ t-inv V ro-vO -l^l " O • § o = ■^ P) o o uiupBajQ puB ui}Baj3 M M M O O oi3i3 fO N Tj- TT ONOO 00 t^ OnoO 00 1/ 1 CO On m ^ O pi I c •sasBg ;b9h Ib;ox >o>o a " OnC t. ^ OlOO M-n- sOPO OONr^O i W5 O " " OnoO - ^nO ro ro -^ O ■>C " o o R ■sauoidaj 1^ ^ ITi « ^ 0^ PO 1/1 O •'toe J 1/ 1 T CO O S ^ ^ MM - i/l O 1/1 1/1 O ON ON l/l ONOO O - T On m vO O CO 1 t^ 1/1 (N r^ MOMt^Mr^O" 1 On - P-J O lO M •sasoa}Ojj N O n fO O Oni^O OnO r^O O 1/ 1 TT CO - CO O O CT. On O --\ONO -co 0\T t^OC NO 00 On ON •suiajojj aiqBin O lO " - O M M loOC rONO On h fo i/lOO «0 m | -Sboq puB aiqujosuj N I^ M O OfOOr^MfOO>- O H O On t^ O ONO fO I- OnO r-ioON^OO> roc r- CO p* PI - OO M i^ m t^o M OnC 00 M 00 PO j.sua!}OJd iB^ox PI MOO i« M i^no m o rr n c CO M ro N M M M '' s 00 O On CO O ,A '-^ O ■ 03 3 ^.2^ Xg a. 'd lU n-t-^ S ^^ '^X'-Z! •■5J ^ (U „-:e.^-^m S-c j;^ :i^ "% ■ p S; ?i c gg '"'aJajD^Qi-tj-S « t;^^^ u S5 c t? ^ O <" >. , ;r ,, « M r Cd- o c . -nil I" c c .C "=2'=a tn C L -uDi o! O « C 3 i).g S nil p: o: oqm s < fC I-: ■>< ec JS S X P- 537- Missouri Exp. Station, Bui. 25. Composition of Flesh of Cattle. Mitchell, C. A. Flesh Foods. London, 1900. OsTERTAG. Handbuch der Fleischbeshau. Pennington, M. E. Changes Taking Place in Chickens in Cold Storage. U. S. Dept. of Agric, Yearbook 1907, p. 197. A Chemical, Bacteriological, and Histological Study of Cold-stored Poultry. Proc. ist Internat. Congress of Refrig. Industries, 2, 1909, p. 216. Studies of Poultry from the Farm to the Consumer. U. S. Dept. of Agric, Bur. . of Chem., Cir. 64. Pennington, M. E., and Greenlee, A. D. An Application of the Folin Method to the Determination of the Ammoniacal Nitrogen in Meat. Jour. Am. Chem. Soc, 32, 1910, p. 561. Pennington, M. E., and Hepburn, J. S. The Determination of the Acid Value of Crude Fat and Its Application in the Detection of Aged Food. Ibid., p. 568. Richardson, W. D., and Scherubel, E. The Deterioration and Commercial Preservation of Flesh Foods. Jour. Am. Chem. Soc, 30, 1908, p. 1515. Salmon, D. E. Inspection of Meats for Animal Parasites. U. S. Dept. of Agric, Bureau of An. Ind., Bui. 19. ScHMiDT-MuLHEiM. Handbuch der Fleischkunde. Leipsic, 1884. Searl, A. Yeast Extract and Its Detection. Pharm. Jour., 71, 1903, pp. 516 and 704; 72, "1904, p. 86. Street, J. P. Meat Extracts and Meat Preparations. Conn. Agl. Exp. Sta., Rep. 1908, Pt. 9, p. 606. Xrowbridge, p. F. Report on the Separation of Meat Proteids. Proceedings of the A. O. A. C, 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 61. U. S. Food Inspection Decisions: No. iio. Shellfish. No. 121. The Floating of Sheimsh. Vaughan, V. C, and Now, F. G. Cellular Toxines. Walley, Thos. a Practical Guide to Meat Inspection. Weber, F. C. Report on Meat and Fish. Proceedings of the A. O. A. C, 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 42. Wiley, H. W. Separation of Flesh Bases from Proteids by Bromine. U. S. Dept. of Agric, Div. of Chem., Bui. 54. Chemical Composition of the Carcasses of Pigs. U. S. Dept. of Agric, Bur. of Chem., Bui. 53. Wiley, H. W., and others. A preliminary Study of the Effects of Cold Storage on Eggs, Quail and Chickens. U. S. Dept. of Agric, Bur. of Chem., Bui. 115. Wintgen, M. Ueber den Nachweis von Hefeextrakt in Fleischextrakt. Arch. Pharm., 242, 1904, p. 537. Woods, C. D. Meats, Composition and Cooking. U. S. Dept. of Agric, Farmer's Bui. 34. Zeitschrift fiir Fleisch und Milch Hygiene, 1891 et seq. CHAPTER IX. EGGS. Nature and Composition.— Though eggs of various birds are used to some extent as food, it is the egg of the hen that is in universal use for this purpose, and therefore the one which is here for the most part dis- cussed, bearing in mind that the structure and composition of all varieties of birds' eggs are closely analogous. Fig. 60 shows the longitudinal section of a hen's egg. 9 Fig. 60.— Longitudinal Section of a Hen's Egg. a, Shell; b, Double Membrane of Shell; c. Air-chamber; d, Outer, or Fluid Albuminous Layer; e, Thick, Middle Albuminous* Layer; /, Inner Albuminous Layer; g, Membrane of the Chalaza; hh, the Chalaza* i, ViteUine Membrane; /, Germ; k, Yolk; /, Latebra. (After Mace.) The average weight of a hen's egg is 60 grams, of which the shell weighs about 6, the white 36, and the yolk 18. Roughly it contains 70% of water, 12% of albumin, and 12% of fat. The shell, according to Konig, has the following composition: Calcium carbonate gn-g^ar Magnesium carbonate o- 2^ Calcium and magnesium phosphate o.k- zp/ Organic substances 2.0- Kp/ 261 262 FOOD INSPECTION AND ANALYSIS. The mean percentage composition of the eggs of the hen, duck, and plover are, according to Konig, as follows: Water, Per Cent. Proteins. Percent. Fat, Per Cent. Nitrogen - free Sub- stance Per Cent. Salts Per Cent. In the Dry Sub- stance. Nitrogen Per Cent. Fat Per Cent. TTen's ecrei' 73-67 71. II 74-43 85-75 50-79 12.55 12.24 10.75 12.67 16.24 12. II 15-49 11.66 0.25 31-75 0-55 0.13 1. 12 1. 1 6 0.98 0-59 1.09 7.66 6.78 6.75 14-25 5-30 A5.99 Duck's eere" 53.62 Plover's oEfi? 45-78 1.78 64-43 White of hen's egg Yolk " " " ..... The Egg-white. — The white of egg has a specific gravity of 1.045, and its reaction is always alkahne. It is a transparent, albuminous fluid inclosed in a framework of thin membrane. The fibrous portion of the memibrane is insoluble in water and in dilute acetic acid. The composition of the fluid substance of the white of egg, according to Lehmann, is as follows: Water 82 to 88% Solids 13-3% (mean) Proteins 12.2% " Sugar 0.5% " Fats, alkaline soaps, lecithin, cholesterin traces Inorganic residue o . 66% The protein substance is for the most part albumin, with a small amount of globulin. According to Osborne and Campbell * the nitrogen compounds of the white of egg are four in number, which they name ovalbumin, ovo- mucin, conalbumin, and ovomucoid. No sharp and distinct separation of these bodies has yet been made. Ovalbumin (albumin) is the chief constituent, and forms by far the largest portion of the protein of the egg-white. In 2.5% solution in water, ovalbumin starts to coagulate at 60°, and yields a dense coagulum at 64°. Stronger solutions require a somewhat higher temperature for coagulation. Ovomucin is a globuHn-like substance, precipitated from egg-white by dilution with water. It is partly soluble in strong sodium chloride solution. When dried and washed with alcohol, it is a light white powder. Conalbumin bears a close resemblance to ovalbumin, but coagulates * Jour. Am. Chem Soc, 22 (1900), p. 422. EGGS. 263 in dilute salt solution at a lower temperature (below 60°), and the coagu- lum is more flocculent than that of ovalbumin. Ovomucoid is not coagulable by heat, and may thus be separated (imperfectly) by filtering out all the coagulable proteins. The last two compounds exist in very small amounts only. Preparation of Albumin.* — By beating up the white of egg in water, the salts and the albumin are dissolved, while the fibrous portion is insolu- ble and is removed by filtration. The filtrate is then treated with a slight excess of basic lead acetate, the precipitate decomposed by treatment with carbon dioxide, and the lead removed by hydrogen sulphide. The solu- tion is warmed cautiously to 60° C, thus beginning to coagulate the albumin, a small part of which, coming down in a flaky form, carries with it the lead sulphide. On filtering or pouring ofif the supernatant liquid after cooling, one obtains a colorless solution of the albumin, which is evaporated to dryness below 40°. The albumin is obtained in the form of transparent yellowish, horny scales, which may be pulverized in a mortar, if desired. Its specific gravity is 1.262. It is tasteless, odorless, and neutral in reaction, and slowly soluble in water. The Egg-yolk. — This is much more complex in composition than the white. Halhburton thus enumerates the constituents of the yolk: (a) Proteins. — Vitellin, the chief one, a globulin resembling myosin. Albumin, in small quantities. Nuclein, combined chiefly with the iron present. (h) Fats. — Olein, palmitin, and stearin. A yellow hpochrome or lutein. (c) Carbohydrates. — Grape sugar in small quantities. {d) Other Organic Constituents. — Lecithin, a phosphorized nitroge- nous body aUied both to the fats and to the proteins. Cerebrin. Cholesterin. (e) Inorganic Salts, the most abundant of which is potassium chloride. Gobley gives the following composition to the egg-yolk: Per Cent. Per Cent. Vitellin 15.8 Nuclein 1.5 Cerebrin , 0.3 Lecithin 7.2 Glycerol phosphoric acid 1.2 Cholesterin 0.4 Fats 20.3 Coloring matters 0.5 Salts i.o Water 51.8 Allen, Com. Org. Anal., 3 Ed., Vol. IV, p. 42. 264 FOOD INSPECTION AND ANALYSIS. Osborne and Campbell,* as the result of long and careful experi- ments, consider the protein of egg-yolk to be largely if not wholly a lecithin compound, having properties of a globulin, and soluble in sodium chloride solution. The fat of the egg yolk, which is used in ointments, has the following characteristics according to Spaeth :t Specific gravity at ioo° C 0.881 Iodine number 68.48 Reichert-Meissl value 0.66 Refractive index at 25° C. (on butyro-refractometer scale) 68.5 Melting-points of fatty acids 36° C. Iodine number of fatty acids 72.6 The mineral content of the egg is thus shown by Konig: COMPOSITION OF THE ASH OF EGGS. Ash of the Dry Sub- stance. Potash. Soda. Lime. Maec- Irnn Oxide. Phos- •Dhoric Acid. Sul- phuric Acid. Silica. Chlo. rine. Hen's egg: entire., white. . yolk... 3-48 4.61 2.91 17-37 31-41 9.29 22.87 31-57 5-87 10.91 2.78 13.04 .14 ■79 13 0-39 0-57 1.65 37-62 4.41 65.46 .32 0.31 1.06 C.86 8.98 28. 82 1-95 The following analyses of eggs were made by Wood and Merrill: J AVERAGE WEIGHTS OF EGGS AND PARTS AS PREPARED FOR ANALYSIS. Weight as Received. Weight Boiled. Shell (Refuse). White. Shell (Refuse). White. Yolk. Total. 1 Yolk. Turkey Goose Duck Guinea fowl. . . Grams. 105-5 190.4 70 6 40.2 Grams. II. 7 24.1 7-2 5-6 Grams. 60. 1 98-5 36.5 20.9 Grams. 30-9 64.8 24.4 12. S Grams. 102.7 187.4 68.1 39-0 Per Cent. II. 4 12.8 10.6 14.4 Per Cent. 56-S 52.6 53-6 53.6 Per Cent, 30.1 34.6 35.8 32.0 1 Shrinkage due to loss in preparation and cooking. * Jour. Am. Chem. Soc, XXII, 1900, p. 413. t Abst. Analyst, 1896, p. 233, X Maine Exp. Sta., Bui. 75, p. 90. EGGS. COMPOSITION OF EGGS. 26c; Protein. si J3 < Trace 0.8 32-9 1.2 II .2 0.9 9-7 Trace 0.8 0.8 36.2 1-3 14.4 I.O 12.3 Trace 0.9 0.8 36.2 1.2 14-5 1.0 12-5 0.8 Trace 0.8 31.8 1.2 12.0 0.9 9-9 0.2 0.7 0.6 33-3 I.I 10-5 1.0 9-3 0.9 ,2 o (1> o. Turkey — white yolk entire edible portion. as purchased Goose — white yolk entire edible portion. as purchased Duck — white yolk entire edible portion. as purchased Guinea fowl-ywhite yolk entire edible portion. as purchased Hen — white yolk. entire edible portion. as purchased 13.8 14.: 13-7 16.9 II-5 17.4 13-4 II. 6 II. 6 17-3 13-8 II. I 16.8 ^3-3 II. 6 12.3 15-7 13-4 II. 9 2-5 7-6 4.2 2-9 8.4 5-1 2-9 2.2 6.8 4.0 Cal. 325 1875 850 735 330 1975 985 860 315 1980 985 880 325 iSoo 87s 730 METHODS OF ANALYSIS. Preparation of the Sample.* — The egg is first weighed as a whole and afterwards boiled hard, cooled, and again weighed. The shell, white, and yolk are then carefully separated and each weighed. After rejecting the shell, the yolk and white are separately reduced by a chopping-knife to the size of wheat grains. These portions are dried partially at a tem- perature not exceeding 45"^, weighed, and afterwards ground to a fine powder in a mortar. Determinations of water, fat, ash, and total nitrogen are made in practi- cally the same manner as with flesh foods. Little attention has been paid as yet to the complete separation and determination of the nitrogen compounds in the white and yolk, and it is customary in most cases to express the protein of the whole as NX6.25. Determination of Lecithin. — Wiley^s Method.'\ — The whole egg, ex- cluding the shell, is placed in a flask with a reflux condenser, and boiled for six hours with absolute alcohol. The alcohol is then evaporated off, and the residue treated in like manner for ten hours with ether. After evaporat- * Woods and Merrill, Maine Exp Sta., Bui. 75, p. 92. t Principles and Practice of Agricultural Analysis, Vol. Ill, p. 431. 256 FOOD INSPECTION /1ND ANALYSIS. ing off the ether, the dry residue is rubbed to a fine powder, placed in an extractor and treated with pure ether for ten hours. The ether extract thus secured is oxidized, after removal of the ether, by fusion with mixed sodium and potassium carbonates, and the phosphorus is determined in the usual way as magnesium pyrophosphate. The amount of lecithin is obtained by multiplying the weight of magnesium pyrophosphate by the factor 7.2703, on the basis of Hoppe-Seyler's formula for lecithin: C,,H,„NPO,. If, for example, an amount of organic phosphorus yielding 0.0848 gram of magnesium pyrophosphate is found in 54 grams of egg exclusive of shell, then 0.0848X7.2703 = 0.61652 and 0.61652X100-^54=1.14. Therefore the percentage of lecithin in the egg is 1.14. Preservation of Eggs. — Owing to the porous nature of the shell, the moisture of the contents gradually grows less by evaporation, and the egg loses in weight. Air also passes in through the shell pores, carrying various microbes, which result in ultimate decomposition and spoiling of the egg. Nature has provided the shell with a thin surface coating of mucilaginous matter, which, however, is easily washed off. This coating tends to partially close the pores, and for best results in keeping should not be removed by washing. Eggs are commonly preserved by protecting them as far as possible from the air. This is accomphshed in a variety of ways, the most common being to pack the eggs in salt or bran, so that the packing medium fills up the interstices between the eggs. Eggs thus packed will keep con- siderably longer then when exposed to the air. A solution of salt is some- times employed, and also lime water, the eggs being simply packed in the solution. The use of lime water is, however, open to the serious objec- tion that a disagreeable odor and taste are imparted to the eggs. Eggs are sometimes coated with gelatin, vaseHne, wax, or gum, so as to cover them with an impervious layer, either by dipping them in the coat- ing medium, or by varnishing or otherwise applying the substance to the egg shell. By far the most efficacious egg coating has been shown by experiments in the North Dakota Experiment Station,* and also in Ger- many, to be sodium and potassium silicate, or water glass. The fresh eggs, preferably unwashed, are packed in a jar, and a 10% solution of water glass is poured over them. According to the North Dakota experi- ments, at the end of three and a half months, eggs packed in this manner the first of August appeared to be perfectly fresh. * Fanner's Bui. 103, U. S. Dept. of Agric, p. 18. EGGS. 267 One drawback to this method is that eggs so treated break more easily on boihng, but this may be prevented by carefully piercing the shell with a strong needle. Cadet de Vanx has proposed immersing the egg in boihng water for twenty seconds, the result being that a very thin layer of the egg-white next the shell becomes coagulated, thus forming an impervious coating inside the shell. Cold-storage Eggs. — The preservation of eggs by storage at low temperatures has become an enormous industry. The temperature employed varies from 24° to 40° C, and the length of storage from one to eight months. Experiments conducted by Wiley,* under authorization from Con- gress, have brought out certain points as to the physical and chemical changes that take place during cold storage. After breaking the shell and keeping at room temperature one day, the odor of eggs stored for 3.5 months was different from that of fresh eggs, but was not disagree- ble. This odor increased on longer storage, and after 12.6 months became very characteristic. After 16.6 months, a musty odor was noticed immediately after opening the egg. Chemical analysis by Cook showed that eggs in storage for one year lost 10% of the total weight, due to evaporation of water from the whites. Storage also caused a lowering of the amount of coagulable protein and of lecithin phosphorus, but an increase in lower nitrogen bodies, pro- teoses, and peptones. The acid reaction of yolks diminished during storage. Microscopical examination by Howard and Read brought out the interesting fact that small rosette crystals of an unidentified substance appeared in the yolk after storage for 12 months or longer, and this observation has since been utilized in the examination of suspected samples. Physical Examination of Eggs. — Various physical tests have been prescribed for ascertaining the approximate age of an egg. Thus, accord- ing to Delarne, if the egg, when placed in a 10% salt solution, sinks to the bottom, it may be considered perfectly fresh; if it remains immersed in the liquid, it is to be considered at least three days old; and if it rises to the surface and floats thereon it is more than five days old. This test * U. S. Dept. of Agric, Bureau of Chem., Bui. 115. 2 68 FOOD INSPECTION AND /IN A LYSIS. is a very rough one, and is useful only for eggs that have been kept in the air. Preserved eggs cannot be gauged by this means. The best method of examining eggs for freshness is "candling," con- sisting in placing the egg between a bright light and the eye. If the egg is fresh, it will show a uniform rose-colored tint, without dark spots, the air-chamber being small and occupying about one-twentieth the capacity of the egg. If the egg is not fresh, it will appear more or less cloudy, being darker as the egg grows older, becoming in extreme cases opaque. At the same time the air-chamber grows larger as the age increases. So-called " spots " are eggs which show on candling black patches due to fungi. Opened Eggs. — In the handling of eggs many become cracked or otherwise injured to an extent which renders them unfit for transporta- tion. These are either sold to bakers for immediate use, or else opened and kept from spoiling by freezing, the addition of preservatives, or drying. The portions of " spot eggs" that do not show evidence of damage are also treated by one of these methods. Eggs which, because of their offensive taste, are unfit for food, are used in the tanning industry. Preservatives commonly employed in opened eggs are boric acid and formaldehyde. The latter is especially effective as an egg pre- servative. If a small quantity be added and stirred into opened eggs that have become absolutely putrid, the result is astonishing. The product is completely deodorized, and exhibits the outward appearance at least of fresh eggs. Formaldehyde, if present, may readily be detected by heating some of the egg directly with the hydrochloric-acid ferric-chloride reagent used in testing milk for formaldehyde, carrying out the process exactly as in the case of milk. Desiccated Egg. — It is possible to evaporate to dryness the contents of the egg to form a powder, the keeping qualities of which far exceed that of ordinary eggs, while it forms a concentrated food which lends itself much more readily to transportation than does the fresh egg in the shell. Several brands of desiccated egg are on the market, which from their analyses are undoubtedly genuine. The -following are analyses of two of them, one (A) made by the Bureau of Chemistry, the other (B) by the Massachusetts State Board of Heahh: EGGS. -69 A. B. Water 6.80 5.95 Protein (NX 6. 25) 45.20 48-15 Protein by cliiTerence 5 1 - 20 Fat 38.5 40.56 Ash 3.5 5.34 Egg Substitutes. — There ha^'e been many preparations in powdered form sold under this name, nearly all claiming to contain all the ingredients of eggs, but most of them falling far short of these claims. Some of them, as for instance those made from desiccated skimmed milk, do contain nitrogenous matter, but as a rule little if any fat. Two samples of "egg substitute" sold in Massachusetts were analyzed with the following results : * A. B. Protein 16.94 18.72 Fat 3.43 3.40 Water 6.71 7.01 Corn-starch, salts, and color- ing matter 72.92 70-87 ' A ten-cent package of sample A, weighing about 2 ounces, was alleged to be equivalent to 12 eggs. Starch furnished the chief ingredient in both samples. One of the most flagrant examples of fraud in this connection was a product sold under the name "N'egg," advertised to contain the nutritive equivalent of the whites and yolks of a dozen eggs, "their composition being based on careful scientific analysis of natural eggs." It was put up in two small boxes, one containing a white and the other a yellow dry powder. Both were entirely devoid of nitrogen, and consisted of nearly pure tapioca starch with a little common salt, the color of the "yolk" being due to Victoria yellow. Some egg substitutes are sold under the name of "custard powders," and are alleged to take the place of eggs in cooking. These are variously made up of mixtures of skim-milk powder, coloring matter, and baking powder ingredients as shown from the following analyses:! * An. Rep. Mass. State Board of Health, 1895, p. 675- t Food and Sanitation, Nov. 25, 1893. 270 FOOD INSPECTION AND ANALYSIS. CUSTARD POWDERS. Starch Albuminous compounds Soluble coloring matter Baking soda Tartaric acid Phosphates -. Carbonates of lime and magnesia Chlorides and sulphates Water Ash 86.25 0.59 •83 •45 84-45 0.58 13.69 0.38 51-03 6.01 15-33 13-69 0.24 2.70 26.38 2.96 50.70 IO-33 9-63 52-32 6.00 22.11 11-37 8.20 53-82 5.06 26.71 6.19 REFERENCES ON EGGS. BORCHMANN, K. Amtliche Kontrolle des Marktverkehrs mit Eiern. Zeits. Fleisch. u. Milchhyg., 17, 1906, pp. 3, 51, 97, 132. Langworthy, C. F. Eggs and their Uses as Food. Farmer's Bui. 128. Osborne, T. B., and Campbell, G. F. Proteids of the Egg Yolk. Jour. Am. Chem. Soc, 22, 1900, p. 413. Protein Constituents of Egg White. Jour. Am. Chem. Soc, 22, 1900, p. 422. Prall, F. Ueber Eier-Konservierung. Zeits. Unters. Nahr. Genuss., 14, 1907, p. 445. Snyder, H. Digestibility of Potatoes and Eggs. Exp. Sta. Bui. 43, p. 20. Wiley, H. W. A Preliminary Study of the Effects of Cold Storage on Eggs, Quail, and Chickens. U. S. Dept. of Agric, Bur. of Chem., Bui. 115. Farmer's Bui. 87. Food Value of Eggs, p. 24. " " 103. Preserving Eggs. CHAPTER X. CEREALS AND THEIR PRODUCTS, LEGUMES, VEGETABLES, AND FRUITS. The chief points of difference in composition between the animal foods already treated of, and those of the vegetable kingdom, are apparent in the relative amounts of proteins and carbohydrates. The proteins present in the cereals and vegetables differ materially both in character and amount from those in the flesh foods, being as a rule present to a much greater extent in the meats than in the grains and vegetables. The leguminous foods, such as peas, beans, and lentils, are, however somewhat exceptional in this respect, being comparatively high in nitrogenous content. The carbohydrates, which in the flesh foods are almost entirely lack- ing, and in milk make up about one-third of the solid matter, form the most important and abundant class of constituents in the vegetable foods. The composition of the principal cereal grains is tabulated as follows by Villier and Collin: Water Nitrogenous substances. Fat Sugar Gum and dextrin Starch Cellulose Ash Wheat. Barley. Rye. Oats. Rice. Corn. Millet. 13-65 13-77 15.06 12.37 13. II 13.12 11.66 12.35 II. 14 11.52 10.41 7.85 9-85 9-25 I-7S 2.16 1.79 5-32 0.88 4.62 3-50 1-45 1.S6 0-95 1. 91 2.46 1 .2.38 1.70 4.86 1-79 [76.52 3-38 h 65.95 64.08 61.67 62.00 54-08 62.57 J 2-53 5-31 2.01 1 1. 19 0.63 2.49 7-29 1. 81 2.69 1. 81 3.02 1. 01 I-5I 2-35 Buck- wheat. 12.93 10.30 2.8e 55-8* 16.43 2.72 The following results of the analyses of cereal grains are summarized from the work of the Division of Chemistry, United States Department of Agriculture : * * Bulletin 13, part 9. 271 272 FOOD INSPECTION AND ANALYSIS. CEREAL GRAINS. Num- ber of Analy- Weight of 100 Ker- nels, Grams. Moist- Pro- teins. Ether Ex- tract. Crude Fiber. Ash. o Wet Gluten Dry Gluten. Barley: Mean Bvick wheat: Mean Corn, domestic: Maximum Minimum Mean Oats, domestic: Maximum . - . . Minimum . Mean Rice: Unhulled Unpolished .. . Polished* Rye, domestic: Maximum Minimum Mean Wheat, domestic: Maximum Minimum. Mean Wheat, foreign: Maximum Minimum. Mean 14 10 4-533, 6.47 3.069 12.31 48.312 12.32 10-608 9.58 38.979 10.93 3.891, 13.02 2.038' 7.87 2.918 10.06 4 6 14 2.929 2.466 2.132 11.52 10.86 11-55 8-=;8 9.88 15-05 9.10 12.15 10.28 11.881 12.34 7 7-95 8.02 4-2oij 11.45 1.932 9.54 2.493 10.62 6-190 14.53 2.125 7. 1 1 3.866 10.62 5-723, 2.250! 4.076 12.97 8-52 11.47 18.99 8.40 12.43 17-15 8.58 12-23 14.52 8.58 12.08 2.67 2.06 5.06 2.94 4.17 6.14 0-93 4-33 1.65 1.96 0.26 2.30 1. 16 1.65 2.50 0.28 1-77 2.26 0-73 1.78 3. SI 10.57 2.00 1. 00 1. 71 16.65 8-57 12.07 10.42 0-93 0.40 2.50 1.65 2.09 ^72 1.70 2.36.. 1.87 2.28 2.87 72.66 1-851 63.34 1-55 1. 19 1.36 4-37 - -47 3-46 4-09 1-15 0.46 2.41 1.7 I 1.92 2-35 1.40 1-82 2.04 1.67 1-73 75-07 68.97 71-95 61.44 53-70 58-75 65.60 76.05 79-36 75-36 63-61 71-37 76-05 66.67 71- 76.14 67.01 70.66 39-05 12.33 26.46 14.65 4.70 10.31 32-57 T2.33 18.72 7.00 25.36 9.82 * Polished rice in the United States is commonly coated with gluccse and talc, ostensibly as a pro- tection against dust and the ravages of insects. Such coating is alowed if declared on the label and directions for its removal are also given. Balland t gives the following percentage composition of beans, lentils, and peas: Beans. Lentils. Peas. Min. Max. Min. Max. Min. 1 Max. Water. , 10.10 13-81 0.98 52-91 2.46 2-38 20 -40 25-46 2.46 60.98 4.62 4.20 11.70 20.42 0-58 56.07 2.96 1-99 13-50 24.24 . 1-45 62.45 3-56 2.66 10 -60 18.88 1-22 56.21 2.90 2.26 14.20 22.48 1.40 6I-IO 5-52 3-50 NiuroTenous substances. Fat Sugars and starches Cellulose Ash f Jour. Pharm. Chem., 1897, pp. 196, 197. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 275 The composition of potatoes, according to Balland,* is as follows: Water. Nitroge- nous Sub- stances. Fat. Sugar and Starch. Cellulose. Ash. Normal state — minimum . . maximum. . Dried — minimum . . 66.10 80.60 1-43 2.81 5-98 13-24 0.04 0.14 0.18 0.56 15-58 29.85 80.28 89.78 0-37 0.68 1.40 3.06 0.44 i.iS 1.66 4-38 ma.ximum. . The composition of the common vegetables, fruits, and berries is thus given by Atwater and Bryant. f VEGETABLES. Asparagus — • Beans, dried — BeanSjfresh Lima Beets, fresh — Cabbage — Carrot, fresh — Celery — CauliBower — Cucumber — Lettuce — Mushrooms — Onion, fresh — Parsnip — Pumpkin — Radish — Rhubarb — Squash^ Tomato, fresh — Turnip — as purchased. . . as purchased. . . —edible portion. . as purchased. . . edible portion. . as purchased edible portion. . as purchased. . . edible portion . . as purchased. . . edible portion . . as purchased as purchased edible portion. . as purchased edible portion . . as purchased. . . as purchased. . . edible portion. . as purchased edible portion. . as purchased. . . edible portion . . as purchased. . . edible portion. . as purchased. . . edible portion. . as purchased. . . edible portion. . as purchased as purchased edible portion. . as purchased 3 II 24 16 27 19 i c* 3 s -2 0) Pi S 94.0 1.8 12.6 22.5 68.5 7-1 55-0 30.8 3-2 87-5 1.6 20.0 70.0 1-3 91-5 1.6 15.0 77-7 1-4 88.2 I.I 20.0 70.6 -9 94-5 I.I 20.0 n-^ -9 92-3 1-8 95-4 .8 15-0 81. 1 -7 94-7 1.2 15-0 80.5 I.O 88.1 3-5 87.6 1.6 10. 78-q 1-4 83.0 1.6 20.0 66.4 1-3 93-1 1.0 50.0 46.5 -5 91.8 1-3 30.0 64-3 -9 94-4 .6 40.0 0.6 -4 88.3 1-4 50.0 44-2 -7 94-3 -9 89.6 1-3 30.0 62.7 -9 3-3, 59-6 22.0 9-9 9-7 7-7 5-6 4.8 9-3 7-4 5-3 2.6 4-7 3-1 2.6 2.9 2-5 6.8 9-9 8.9 13-5 10.8 5-2 2.6 8-3 5-8 3-6 2.2 9.0 4-5 3-9 8.1 5-7 o .8 4-4 1-7 .8 -9 I.I I.I 2-5 1.2 -7 •7 I.I .8 .6 1-3 c3 Q a> ^^ o fe 105 1605 570 255 215 170 145 125 210 160 85 70 140 80 70 90 75 210 225 205 300 240 120 60 135 95 105 65 215 105 105 185 125 * Jour. Pharm. Chem., 1897, pp. 298-300. t Bui. 28, Office of Exp. Station U. S. Dept. of Agriculture. 274 FOOD INSPECTION ^ND AN yi LYSIS. FRUITS. Apples — Apricots — Bananas^ Blackberries — Cherries — Cranberries — Currants — Figs, fresh — Grapes — Huckleberries - Lemons — Muskmelons — Oranges — Pears — Pineapple — Plums — • Prunes — Raspberries — Strawberries — Watermelon — edible portion . . , as purchased edible portion as purcha'-ed edible j^ortion as purchased as purchased. . . . edible portion as purchased , as purchased ., as purchased as purchased edible portion as purchassd -edible portion edible portion as purchased edible portion as purchased edible portion as pui chased edible portion as purchased edible portion edible portion..., as purchased edible portion as purchased as purchased edible portion as purchased edible portion as purchased <^ 01 O ^ 1^ 29 9 16 28 5 23 24 1-3 i.o -9 -4 1-5 i-S 1-3 1.0 .6 1.0 -7 .6 -3 .8 .6 .6 -5 .4 1.0 •9 ■9 ■7 •9 ■4 .2 14. 10. 13- 14. 10. 16. 15- 9- 12.8 •4 .6 ■5 •9 ■3 .6 II. 6 8-5 14. 1 12.7 9-7 20.1 19. 1 18. 17- 12. 7- 7- 6. 2. 1.6 2-5 1-5 4-3 2-7 2.9 1-4 290 220 270 255 460 300 270 365 345 215 265 380 450 335 345 205 145 185 90 240 170 29s 260 200 395 370 370 335 255 180 175 140 60 The following analyses of apples made by Browne * are of interest. The first four analyses show the changes that occur in the composition of a Baldwin apple at different stages of its growth. Below these is given the average of the analysis of 160 samples, representing 27 varieties of apples. COMPOSITION OF A BALDWIN APPLE AT DIFFERENT PERIODS. Condition. Water. Solids. Invert Sugar. Su- crose. Total Sugar. Total Sugar after In- version. Starch. Free Malic Acid. Ash. Sugar Co- efficient. Very green. . Green Ripe Over-ripe. .. 81.53 79.81 80.36 80.30 18.47 20.19 19.64 19.70 6.40 6.46 7.70 8.81 1.63 4-05 6.81 5.26 8.03 10.51 14-51 14.07 8. II 10.72 14-87 14-35 4.14 3-67 0.17 1. 14 0.65 0.48 0.27 0.27 0.28 47.16 53-10 75-71 72-84 * Penn. Dept. of Agriculture, Bulletin 58. CEREALS, LEGUMES, l/EGETABLES, AND FRUITS. 275 AVERAGE COMPOSITION OF 27 VARIETIES OF APPLES. Water 83.57 Solids 16.43 Invert sugar 7.92 Sucrose 3-99 Total sugar 11. 91 Total sugar after inversion 12.12 Free malic acid 0.61 Ash 0.27 Sugar coefficient 73-76 The composition of the commoner nuts is shown in the following table:* NUTS. Almonds — Beechnuts — Brazil-nuts^ Butternuts — Chestnuts, fresh — Cocoanuts — Filberts — Hickory-nuts — Peanuts — Pecans — Pistachios — Walnuts, Calif'nia- edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, as purchased. . edible portion, -edible portion, as purchased . . K 45-0 40.8 49-6 86.4' 16.0 48.8 52-1 62.2 24-5 53-2 73- Ph 20.0 11-5 21.9 13.0 17.0 8.6 27.9 3.8 6.2 5-2 5-7 2.9 15.6 7-5 15-4 5-8 25-8 19-5 II. o 5-2 22.3 18.4 4-9 02 17-3 9-5 13.2 7-8 7.0 3-5 3 5 .5 42.1 35-4 27.9 14-3 13.0 6.2 II. 4 4-3 24.4 18.5 13-3 6.2 16.3 13-0 3-5 2-5 1-4 I.I 3-5 2.b 3-9 2.0 2-9 -4 1-3 I.I 1-7 -9 2.4 I.I 2.1 .8 2.0 1-5 1-5 -7 3-2 1-7 -5 I ad 3030 1660 3075 1820 3265 1655 3165 430 II25 945 2760 1413 3290 1575 3345 1265 2560 1935 3455 1620 2995 Vegetables and Fruits furnish a large and most important portion of our food supply, but are naturally not included in their fresh state among the foods examined by the public analyst for adulteration, hence * U. S. Dept. of Agric, Oflf. of Exp. Station, Bui. 28. 276 FOOD INSPECTION /iND ANALYSIS. but little space need be given them beyond a resume of their composition, and an outline of methods of proximate analysis applicable to their exam- ination for food values. When, however, these products undergo the various processes incidental to their treatment for long keeping, such as preserving, canning, drying, pickling, and mixing vv^ith other ingredients, it is then that many varieties of fraudulent adulteration are practiced. Vegetable foods thus prepared form the subject of a separate chapter. Besides the proximate components that commonly occur in vegetable products, there are three other substances worthy of mention found in vegetables and fruits, viz., inosite, pectose, and inulin. Inosile, CQii^2^6y 2H2O, is not a carbohydrate, but, according to Ham- mersten, is an aromatic compound. Besides occurring in unripe fruits, it is found in green asparagus and beans. Pectose is a substance the exact nature of which has not been fully determined, though it is thought to be a carbohydrate. It gives to unripe fruits and vegetables their peculiar hardness, and furnishes the basis for their gelatinous constituents. When the vegetable or fruit ripens, the insoluble pectose is then transformed by the action of acids and possibly of ferments into pectin, a vegetable jelly, which gives to fruit juice the property of gelatinizing when boiled. Inulin, (CeHioOg)^, is a starch-like substance, occurring in the roots of chicory and dandelion, and in the tubers of the artichoke. It is a white, starch-like powder, slightly soluble in cold, and readily soluble in hot water, and converted into levulose by boiling with water, or by the action of acids. METHODS OF PROXIMATE ANALYSIS. Preparation of the Sample. — Cereals and other dry products should be ground in a hand mill or iron mortar so as to pass a sieve with round holes I mm. in diameter. Green vegetables, roots, fruits, etc., may be reduced to a pulp in a food chopper. The following methods, with the exception of the Brown and Duvel method, are those of the Association of Ofhcial Agricultural Chemists for the analysis of foods and feeding stuffs.* Moisture. — Dry a quantity of the substance, representing about 2 grams of the dry material, to constant weight (about five hours) at the temperature of boiling water, in a current of dry hydrogen or in vacuo. The apparatus described on page 62 may be used. * U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.). CEREALS, LEGUMES, I^EGE TABLES, AND FRUITS. 277 Ash. — Burn 2 grams of the substance in a platinum dish at the lowest possible red heat, as described on pages 62 and 63. If a white or light- gray ash cannot be obtained in this manner, exhaust the charred mass with water, collect the insoluble residue on a filter, burn, add this ash to the residue from the evaporation of the aqueous extract, and heat the whole at low redness until white or nearly so. Ether Extract (Fat, etc.). — Extract the residue from the determination of moisture for sixteen hours with anhydrous alcohol-free ether in a continuous extractor (p. 63) and ury the extract to constant weight in a water-oven. The ether extract may also be determined indirectly from the difference in weight of the dried substance before and after extrac- tion. Protein. — Determine the total nitrogen by the Gunning or Kjeldahl method, using i gram of the substance- Calculate the protein by mul- tiplying the total nitrogen by the appropriate factor, which varies with the different cereals as follows: wheat, 5.70; rye, 5.62; oats, 6.31; corn, 6.39; and barley, 5.82. Ordinarily the conventional factor 6.25 is employed. Crude Fiber [Cellulose, Lignin, etc.). — Transfer the residue, after extraction for the determination of the ether extract, to a 500-cc. Erlen- meyer flask, with a mark showing 200 cc, add boiling 1.25% sulphuric acid to the mark, heat at once to boiling, and boil gently for thirty minutes, shaking cautiously from time to time to prevent the material from crawling up on the sides of the flask. Filter through paper, and wash once with boiling water. Rinse the substance back into the same flask with 200 cc. of a boiling 1.25% solution of sodium hydroxide, free, or nearly so, from sodium carbonate, boil at once, and continue the boiling for thirty minutes in the same manner as directed above for the treatment with acid. Filter on a tared filter-paper or Gooch crucible, and wash with boiling water till the washings are neutral. Dry at 110° and weigh, after which incinerate completely and correct for ash. If a tared filter is used, it should be previously dried at iio'^ for one hour in a glass-stoppered weighing bottle, cooled for fifteen minutes and weighed. After collecting the fiber on the filter, it is well to wash successively with alcohol and ether to facilitate drying. The filter should not be pushed down into the weighing bottle until the fiber is dry to the touch after which two hours' drying at 110° will be sufficient. A blank should be made to ascertain the loss sustained bv the j<er on treatment with alkali and the necessary correction intro- 278 FOOD INSPECTION AND ANALYSIS. duced. This error and others can be avoided by filtering on a Gooch crucible, but with many materials this cannot be used because of clogging. The acid and alkali solutions must be exactly 1.25% as determined by titration. Nitrogen-free Extract (Starch, Sugar, Gums, g/c.).— Subtract the sum of the moisture, ash, ether extract, protein, and crude fiber, from 100. Determination of Moisture in Grain, Legumes, Oil Seeds, etc. — Brown and Diivel Method.^ — This method is especially useful in guarding against an excessive amount of moisture in grain, which not only adds weight but also causes deterio- ration through the growth of bac- teria and moulds. The apparatus (Fig. 61) consists of a condenser- tank (A) and an evaporating-chamber {B) with a cover {k) and a mica window {m), the whole su'pported on a stand (C) . It is arranged for conducting six distillations at the same time. The distilling-flask is shown at the left (/>') in the wooden rack used only during filling and at the right [p) in position for distillation. Weigh into the distilling-flask 100 grams (corn, barley, wheat, rye, unhulled rice, kafir, flaxseed, soy bean) or 50 grams (oats, cottonseed) of the whole grain and add 150 cc. Fig. 6 1. -Brown and Duvel Apparatus for ^f hydrocarbon engine oil with a Determination of Moisture in Grain. ^ , . . r n End View. flash-pomt m an open cup of 200 - 205° C. Close the neck of the flask with a rubber stopper carrying a thermometer {q), the bulb of which extends well into the mixture of oil and corn; connect the side tube by means of another cork with the condenser-tube {s), and heat with the Bunsen burner, so as to bring (in twenty minutes) to the U. S. Dept. of Agric, Bur. of Plant. Ind., Bui. 99, and Circular 72. CEREALS, LEGUMES, U'EGETABLES, AND FRUITS. 279 proper temperature, which for corn, barley, rice, kafir, and cottonseed is 190°, for wheat 180°, for rye and flaxseed 175°, for soy bean 170°, and for oats 195° C. When the desired temperature is reached turn off the flame, and allow to stand until the moisture ceases to drop from the condenser-tube into the graduate (/). The number of cc. in the graduate represents the amount of moisture in the grain. The results agree closely with those by drying to constant weight in a water-oven at 100°. After the determination is finished empty the contents of the flask on a suitable strainer, thus recovering the oil for further use. CARBOHYDRATES OF CEREALS AND VEGETABLES. Classification. — As a rule the same carbohydrates are found in all cereals, being present, however, in varying proportions. By far the greater part of the carbohydrate content of cereals is starch, the other carbohydrates being comparatively small in amount, so that in rough work it is sometimes customary, though incorrect, to assume the entire amount of so-called *' nitrogen-free extract"' or carbohydrates (as determined by difference) to be starch. The carbohydrates occurring in cereals may be classified as follows: r Starch (Insoluble I Cellulose [ Pentosans r Sucrose So'"* g:rr [ Raffinose (traces) Starch (CgHioOs)^. — Pure starch is a glistening, white, granular powder having a peculiar feeling when rubbed between the thumb and finger. It is a very hygroscopic, commercial starch containing about 18% of moisture. Starch is very widely distributed in the vegetable kingdom, occurring in almost every plant at some stage in its growth. Starch is insoluble in cold water, alcohol, and ether; it is soluble in hot water, though not without change. By boiling with dilute acids, starch is first converted by hydrolysis into a mixture of dextrin and maltose, and finally by prolonged boiling into dextrose. Malt extract also hydrolizes starch in solution. Detection. — Starch is best detected, when present to any appreciable extent in any mixture, by boiling a portion of the sample in water, cooling, and applying a solution of iodine. A characteristic blue color is pron duced if starch is present. Very small amounts of starch are best ident 2 So FOOD INSPECTION AND ANALYSIS. tified in powdered mixtures by applying a drop of a solution of iodine to the dry powder on a microscope slide, or, better, to the powder previously rubbed out with water on a slide under a cover-glass ; the starch granules, if present, will be colored intensely blue by the iodine, and are at once rendered apparent when viewed through the microscope. Though the cereal and vegetable starches, whatever their origin, are identical chemically, the various starch granules have certain character- istics, when viewed under the microscope, that render their identifi- cation easy in most cases. A knowledge of the microscopical appear- ance of the common vegetable starches is of the utmost importance to the public analyst, who frequently finds them as adulterants of various foods, such as coffee, cocoa, spices, etc. For microscopical examination, powdered samples should be ground fine enough to pass through a 60 or 80 mesh sieve. Classification. — As seen under the microscope tlie starch granules of various grains and vegetables differ in form, size, and often in their manner of grouping. Thus, at the outset, the common starches may be divided as to the microscopical form of their granules into three classes, viz., lenticular, irregularly oval, and polygonal. To the first class, in which the starch granule has in general the circular disk form, belong rye, wheat, and barley. Representing the second or irregularly elliptical class are the pea, bean, potato, and arrowroot. In the third, or polygonal class, should be included corn, oats, buckwheat, and rice. In thus character- izing the distinguishing forms as lenticular, oval, and polygonal, it should be borne in mind that while the tendency of the most typical starch granules in each class, when viewed in normal position, is toward the circular, the oval, or the polygonal as the case may be, it is not by any means true that all or even most of the granules in any one instance perfectly conform to one of these shapes throughout. Thus, lenticular wheat granules, when viewed edgewise, will appear elliptical, and are often distorted in shape, especially when roasted; and polygonal buckv/hcat granules may in many instances have such obtuse angles as to appear circular. It is the general trend of all the starches toward one or another of these shapes that suggests the classification. The identification of the various starches morphologically is indeed the most natural and ready method. Not only the character of the starch, but also its approximate amount, when present in mixtures, can in many instances be ascertained by a careful examination with the microscope. The analyst should be provided with samples of starches of known CEREALS, LEGUMES, l^EGETABLES, AND FRUITS. 281 purity conveniently at hand, and in all doubtful cases these should be referred to for comparison. Wheat Starch (Fig. 152, PL VIII). — This starch is frequently present in adulterated pepper, mustard, ginger, cocoa, coffee, and other foods. Its granules occur for the most part in two sizes, of which the larger are lenticulars, varying from 0.021 mm. to 0041 mm., or rarely 0.050 mm., in diameter, while the smaller are rounded or polygonal, averaging about 0.005 ^'^'^- '^^ diameter. The smaller granules are grouped irregu- larly in and around the larger, there being six to ten of the former to one of the latter. The larger granules are, however, the most distinctly characteristic, and are usually readily recognized in a mixture, not only by their shape, but by reason of the concentric rings with which they are provided, and which are generally but not always apparent. Barley. Starch (Fig. 124, PI. I). — This much resembles wheat, in that it has two sizes of granules, but both sizes are respectively smaller than those of wheat, though present in about the same proportion. The larger lenticular disk-like granules vary from 0.013 mm. to 0.035 "ini. in diameter, while the smaller average 0.003 ^^^- The concentric rings are less apparent in the barley than in the wheat. Rye Starch (Fig. 148, PI. VII) has also two sizes of granules, but the larger vary from 0.025 mm. to over 0.05 mm, in diameter, and are considerably larger than the corresponding wheat granules. The smaller granules average about 0,004 i^im. in diameter. As in the case of wheat and barley, the larger granules are lenticular, while the smaller are rounded or polygonal. The concentric rings are usually indistinct in the large granules, and many of these show cross-shaped rifts in the center. Corn Starch (Fig. 133, PI. IV). — This starch is a common adulterant of spices, cocoa, and other foods. It is placed in a series of four cereal starches whose granules are polygonal, and all of which show more or less tendency to arrange themselves in close contact side by side in masses suggestive of a tessellated or mosaic floor. Arranged in order of the size of their grains, these starches are: Corn, buckwheat, oats, and rice. Corn starch granules tend toward the hexagonal in shape, varying from 0.007 "im. to 0.035 t^t^- in diameter, and having very marked rifted hila. They are most readily recognized in any mixture, and from their size are readily distinguishable from the other polygonal starches, which never reach 0.017 ^^- ^^ diameter. Buckwheat Starch (Fig. 128, PI. II, and Fig. 129, PI. III).— This is a very common adulterant of many spices, especially pepper, which, as 282 FOOD INSPECTION AND ANALYSIS. shown in Fig, 256, PL XXXIV, it much resembles in the manner in which its masses of granules group themselves, conforming to the shape of the cells. The individual granules are commonly 0.006 mm. to 0.012 mm. in diameter. Curious rod-shaped aggregates of two to four indi- viduals are of frequent occurrence. Oat Starch (Fig. 139, PI. V). — The granules of this starch vary from 0.002 mm. to 0.012 mm. in diameter, and are polygonal, or less often rounded or spindle-shaped in form. They have no rings or hila, and arrange themselves in rounded aggregates of from two to many granules that at first sight might be mistaken for large grains; careful examina- tion, however, shows the dividing lines. Rice Starch (Fig. 143, PI. VI). — The granules of rice starch resemble closely those of oats both in form and size, but spindle-shaped forms are not present. As in the case of oats, the granules are often united to form rounded aggregates. Starches of the Pea and Bean. — The starches of these legumes much resemble each other, and are with difficultly distinguished one from the other (see Fig. 164, PI. XI, and Fig. 154, PL IX). The granules are more nearly oval than most other starches, and have both concentric rings and elongated hila. The granules of the pea show a less distinct hilum than those of the bean, and some of them are irregularly swollen. Both peas and beans roasted are commonly used as adulterants of coffee. Arrowroot. — There are many varieties of arrowroot, including Jamaica, Bermuda, East Indian, Australian, and others, all having certain varia- tions in form and size, but resembling each other in a general way. Fig, 167, PL XII, shows the Bermuda arrowroot, the granules of which are somewhat egg-shaped, being usually smaller at one end than the other, and having rifted hila near the small end. Potato Starch (Fig. 165, PL XII), — This starch has large, irregularly oval granules, with very apparent hila situated eccentrically near one end, and with rings around the hilum. The granules are about 0.07 mm. in large diameter. Fig. 134, PL IV, and Fig. 166, PL XII, show corn and potato starch when viewed with polarized light with crossed Nicol prisms, the specimens being mounted in Canada balsam. Tapioca Starch. — The granules of this starch, as shown in Fig. 168, PL XII, are more uniform in size throughout than those already de- scribed, averaging about 0,018 mm, in diameter, and being quite smoothly circular^ without concentric rings, but having a distinctly dotted hilum in CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 283 the center. Many of the grains are cup-shaped, as if a segment of the circle had been removed. Sago Starch (Fig. 172, PI. XIII.) — The granules of sago starch vary much in size, and might be called irregularly ellipsoidal in shape with one or more truncated surfaces. Some of them have indistinct concentric rings, and in some, but not all, a hilum is apparent, usually near one end of the granule. Microscopical Appearances of Starches with Polarized Light. — ^With polarized light starch granules show dark crosses, the point of inter- section being at the hilum (Fig. 166, PI. XII). These crosses vary in distinctness with the variety. Certain of the starches show a play of colors with polarized light and a selenite plate, especially those whose granules have some sort of hilum. This is particularly striking in such starches as corn, tapioca, potato, and arrowroot. Blyth has made the phenomenon a means of classification of the starches, but the writer considers their appearance with ordinary light sufBcient for identifica- lion. Canada balsam is the best mountant for examination in polar- ized light. Estimation of Starch. — Direct Acid Conversion. — By this method the hemicellulose, if present, or such of the carbohydrates as are capable of being converted to sugar, are reckoned in with the starch. Where little or none of the insoluble carbohydrates other than starch are present, as for instance in the case of commercial starches, this method is sufficiently accurate. Exhaust 3 grams of the finely divided substance on a fine but rapidly acting filter with ether by washing with 5 successive portions of 10 cc. each, and wash the residue first with 150 cc. of 10% alcohol and then with a little strong alcohol. Transfer by washing to a flask with 200 cc. of water and 20 cc. of hydrochloric acid (specific gravity 1.125), connect with a reflux condenser, and heat the flask in boihng water for 2 J hours. Cool, and carefully neutrahze with sodium hydroxide, clarifying if neces- sary with alumina cream. Mix well, make up the volume to 500 cc, filter, and determine the dextrose in an aliquot part of the filtrate by any of the methods for dextrose. Convert dextrose to starch by the factor 0.9. Diastase Method. — By this method the hemicellulose is not con- verted, only the -Starch being acted upon. Hence for exact work in the presence of other insoluble carbohydrates this method is to be recom- mended. Under the action of diastase, starch is first converted into 284 FOOD INSPECTION yIND y^N^ LYSIS. maltose and dextrin, and finally into dextrose, in somewhat the following manner: i2CeH,A+4H30 = 4CnH3A,+ 2C,H3.0,„ Starch Maltose Dextrin Ci2H,30„ + H.O = 2C6H„08 C,.H,,Oio+ sH.O = 2C6H,,08 Maltose Dextrose Dextrin Dextrose Exhaust 3 grams of the material, ground to an impalpable powder, with ether and alcohol as in the acid conversion method, wash the residue into a beaker with 50 cc. of w"ter and immerse in a boiling water-bath. Keep in the bath for 15 minutes or until completely gelatinized, stirring constantly, and cool to 55° C. Add 20 cc. of malt extract and digest at 55° C. one hour. Heat again to boiling, boil for 15 minutes, replacing the water lost by evaporation, cool to 55° C, and digest as before with 20 cc. of malt extract for one hour or until the residue treated with iodine solution shows no starch under the microscope. Cool, make up to 250 cc, filter, pipette 200 cc. into a flask, add 20 cc. of hydrochloric acid (specific gravity 1.125) and proceed as in the acid conversion method. Correct for the copper-reducing power of tne malt extract as below. Preparation of Malt Extract. — Digest at room temperature 10 grams of freshly pulverized malt with 200 cc. of water for 2 to 3 hours with occasional shaking and filter. Determine the amount of dextrose in a given volume of the extract after heating with acid, etc., as in the actual analysis and make the proper correction. Use of ''Animal Diastase.'^ — Pancreatin and similar powdered prepara- tions, such as " vera diastase " and " panase," obtained from the pancreas of cattle and hogs, are preferable to diastase as starch-converting reagents, since, as a rule, they have no copper-reducing power, thus obviating a correction. Use instead of the malt extract the same amount, viz., 20 cc, of a 0.5% aqueous solution of powdered U. S. P. pancreatin in starch deter- minations as above described. Determination of Sugars in Grain and Cereal Products. — Method of Bryan, Given and Straughn.* — Place 12 grams of the material in a 300- cc graduated flask (if acid add 1-3 grams of precipitated calcium car- bonate), add 150 cc of 50% (by vol.) alcohol (carefully neutralized), mix and boil on a steam bath under a reflux condenser for one hour. Cool, and if desired allow to stand overnight. Make up to volume with neutral 95% alcohol, mix, allow to settle, pipette 200 cc. into a beaker, and evaporate *U. S. Dept. of Agric. Bur. of Chem., Circ. 71. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 285 on the steam bath to 20-30 cc. Transfer to a 100 cc. graduated flask with water, add enough saturated normal lead acetate solution to produce a flocculent precipitate, and allow to stand 15 minutes or if desired over- night. Make up to the mark with water and pass through a folded filter, saving all the filtrate. Precipitate the lead, with anhydrous sodium carbonate, allow to stand 15 minutes and pour onto an ashless filter. Dilute 25 cc. of this clear filtrate with 25 cc. of water and determine reduc- ing sugars by the Munson and Walker method (p. 598). In a 100 cc. graduated flask place 50 cc. of the same filtrate, neutralize to litmus paper with acetic acid, add 5 cc. of concentrated hydrochloric acid, and let stand overnight (or if desired 48 hours) for inversion. Neu- tralize in a large beaker with anhydrous sodium carbonate; return to the 100 cc. flask and make up to the mark. Filter and determine total sugars as invert in 50 cc. of the filtrate by the Munson and Walker method. Multiply the difference between the percentages of invert sugar before and after inversion by 0.95, thus obtaining the per cent of sucrose. Cor- rect the percentages of both sucrose and reducing sugars for the volume of the alcohol precipitate by multiplying by 0.97. Cellulose forms the framework of all vegetable organisms, being next to water, the most abundant substance in the vegetable kingdom. Pure cellulose is white, translucent, and of fibrous or silky texture. It is insoluble in water, alcohol, and ether, but dissolves readily in an ammoniacal solution of cupric hydroxide known as Schweitzer's Reagent or " cuprammonia," (p. 93). Cellulose turns violet when treated with chloriodide of zinc, and blue when treated with sulphuric acid and iodine in potassium iodide (p. 91). The " crude fiber," as determined in foods, being the portion that resists the action of hot dilute acid and alkali, is composed largely of cellulose. The Pentosans are amorphous, insoluble in water, but soluble in dilute alkali, and are converted by boiling with dilute acids into so-called pentose sugars, the best known of which are xylose and arabinose, corresponding to the pentosans xylan and araban respectively. Hemicellulose is the more appropriate generic term for the insoluble carbohydrates capable of hydrolysis by acids to sugars, inasmuch as there are insoluble bodie besides the pentosans that may thus be converted into suo^ar, such as the hexosans, hydrolyzed by acid to hexose sugars, mannose, galactose, etc. Since the greater portion of these insoluble hydroliz- 286 FOOD INSPECTION y4ND ANALYSIS. able carbohydrates are pentosans, it is simpler to calculate them all as such. Determination of Pentosans. — Pentosans are determined either by hydrolyzing to reducing sugar, and estimating the latter as described on page 296 (Stone's method) or by calculation from the furfural* yielded on distillation with hydrochloric acid, as carried out in the provisional method of the A. O. A. C.f as follows: Place 3 grams of the material in a flask together with 100 cc. of 12% hydrochloric acid (specific gravity 1.06) and several pieces of recently heated pumice stone, connect with a condenser and heat on a wire gauze, rather gently at first, using a gauze top to distribute the flame so as to distil over 30 cc. in about ten minutes and passing the distillate through a small filter. Replace the 30 cc. driven over with a like amount of the 12% acid added through a separatory funnel in such a manner as to wash down the particles on the sides of the flask and continue the process until the distillate amounts to 360 cc. To the distillate add gradually a quantity of phloroglucinol (free from diresorcin) dissolved in 12% hydrochloric acid, about double that of the]furfural expected. The solution first turns yellow, then green, and soon an amorphus greenish precipitate appears, which rapidly grows darker, finally becoming almost black. Make the solution up to 400 cc. with 12% hydrochloric acid and allow to stand over- night. Filter the amorphous black precipitate on a Gooch crucible, wash with 150 cc, of water, keeping the precipitate covered with the liquid until the last portion has run through, dry for four hours at the temperature of boiling water, cool in a weighing bottle and weigh. Calculate by Krober's formulae as follows : {a) For weight of phloroglucide " a " under 0.03 gram: Furfural = (a + 0.0052) X0.5170. Pentoses = (a + 0.0052) Xi. 01 70. Pentosans = (a + 0.0052) X 0.8949. * Furfural or furfuraldehyde (CSH4O2) is the aldehyde of pyromucic acid. It is a color- less liquid, having an odor suggestive of cassia. Its boiling-point is 162° and its specific gravity 1.164. It is sparingly soluble in water and readily soluble in alcohol. Nearly half the tissue of ordinary bran, exclusive of proteins and starch, yields furfural on distilla- , tion with acid. t U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 54. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 287 {h) For weight of phloroglucide " a " over 0.300 gram. Furfural = (a + o.oo52)Xo.5i8o. Pentoses = (a + 0.005 2) X 1.0026. Pentosans = (a + 0.0052) X 0.8824. For weight of phlorogkicide "a" from 0.03 to 0.300 gram use Krober's table (pp. 288-294) to calculate the weight of pentoses (arabinose, xylose), and pentosans (araban, xylan). The reactions that take place are thought to be somewhat as follows: C5Hs04 + H20 = C5Hio05. Pentosan Pentose C5H,o05 = C5H,02 + 3H20. " Pentose Furfural 2C5H402 + C6H603 = Ci6Hi206 + H20. Furfural Phloroglucinol Phloroglucide The theoretical yield of phloroglucide should be 2.22 parts to one of furfural, but in practice this is never obtained. The varying factors for calculation as above given are based on experiment. The phloroglucinol used should be free from diresorcin. To test for the latter, dissolve the reagent in acetic anhydride, heat nearly to boiling, and add a few drops of concentrated sulphuric acid. If more than a faint violet color is produced, the phloroglucinol should be purified as follows : Heat in a beaker about 300 cc. of hydrochloric acid (sp. gr. 1.06) and II grams of commercial phloroglucinol, added in small quantities at a time, stirring constantly until it has almost dissolved. Some im- purities may resist solution, but it is unnecessary to dissolve them. Pour the hot solution into a sufficient quantity of the same hydrochloric acid (cold) to make the volume 1500 cc. Allow it to stand at least overnight — better several days — to allow the diresorcin to crystallize out, and filter immediately before using. The solution may turn yellow, but this does not interfere with its usefulness. In using it, add the volume containing the required amount to the distillate. 2S8 FOOD INSPECTION AND ANALYSIS. KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS FROM PHLOROGLUCID. I 2 3 4 5 6 7 8 . Phloroglucid Furfural. Arabinose. Araban. Xylose. Xylan. Pentose. Pentosan. 0.030 0.0182 0.0391 0.0344 0.0324 0.0285 0-0358 0.0315 -031 .0188 .0402 -0354 •om .0293 .0368 .0324 .032 -0193 -0413 ■°z(^i .0342 .0301 -0378 •0333 -033 .0198 .0424 •0373 -0352 .0309 .0388 .0341 -034 .0203 -0435 ■0383 .0361 -0317 .0398 •0350 -035 .0209 .0446 -0393 .0370 .0326 .0408 -0359 .036 .0214 -0457 .0402 •0379 -0334 .0418 .0368 .037 .0219 .0468 .0412 .0388 .0342 .0428 ■0377 .038 .0224 .0479 .0422 .0398 -0350 -0439 .0386 -039 .0229 .0490 -0431 .0407 -0358 .0449 -0395 .040 -0235 .0501 .0441 .0416 .0366 -0459 .0404 .041 .0240 .0512 -0451 .0425 ■0374 .0469 -0413 .042 .0245 -0523 .0460 ■0434 .0382 .0479 .0422 .043 .0250 -0534 .0470 -0443 .0390 .0489 -0431 .044 -0255 -0545 .0480 .0452 .0398 .0499 .0440 .045 .0260 -0556 .0490 .0462 .0406 .0509 .0448 .046 .0266 .0567 .0499 .0471 .0414 -0519 -0457 .047 .0271 -0578 .0509 .0480 • .0422 .0529 .0466 .048 .0276 .0589 -0519 .0489 .0430 ■0539 -047s .049 .0281 .0600 .0528 .0498 .0438 ■0549 .0484 .050 .0286 .0611 -0538 .0507 .0446 -0559 .0492 .051 .0292 .0622 .0548 .0516 -0454 .0569 .0501 .052 .0297 -0633 -0557 -0525 .0462 -0579 .0510 .053 .0302 .0644 .0567 -0534 .0470 .0589 ■0519 .054 .0307 -0655 .0576 -0543 .0478 •0599 .0528 -OSS .0312 .0666 .0586 ■0553 .0486 .0610 -0537 .056 .0318 .0677 .0596 .0562 .0494 .0620 .0546 .057 -0323 .0688 .0605 -0571 .0502 .0630 -0555 .058 .0328 .0699 .0615 .0580 .0510 .0640 .0564 •059 •0333 .0710 .0624 .0589 .0518 .0650 -0573 .060 -0338 .0721 .0634 .0598 .0526 .0660 .0581 .061 -0344 .0732 .0644 .0607 -0534 .0670 .0590 .062 -0349 -0743 .0653 .0616 -0542 .0680 •0599 .063 -0354 -0754 .0663 .0626 -0550 .0690 .0608 -064 ■0359 .0765 .0673 -0635 -0558 .0700 .0617 .065 .0364 .0776 .0683 .0644 .0567 .0710 .0625 .066 .0370 .0787 .0692 -0653 -0575 .0720 .0634 •067 -037s .0798 .0702 .0662 ■0583 .0730 .0643 .068 .0380 .0809 .0712 .0672 •0591 .0741 .0652 .069 ■0385 .0820 .0721 .0681 . -0599 -0751 .0661 CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 2S9 KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS FROM PHLOROGLUCID— Co«/i«Mcrf. I 2 3 4 5 6 7 8 Phloroglucid Furfural. Arabinose. Araban. Xylose. Xylan. Pentose. Pentosan. 0.070 0.0390 0.0831 0.0731 0.0690 0.0607 0.0761 0.0670 .071 .0396 .0842 .0741 .0699 .0615 .0771 .0679 .072 .0401 .0853 -0750 .0708 .0623 .0781 .0688 •073 .0406 .0864 .0760 .0717 .0631 .0791 .0697 .074 .0411 ■0875 .0770 .0726 .0639 .0801 .0706 .075 .0416 .0886 .0780 .0736 .0647 .0811 .0714 .076 .0422 .0897 .0789 -0745 .0655 .0821 .0722 .077 .0427 .0908 .0799 •0754 .0663 .0831 •0731 .078 .0432 .0919 .0809 .0763 .0671 .0841 .0740 .079 •0437 .0930 .0818 .0772 .0679 .0851 .0749 .080 .0442 .0941 .0828 .0781 .0687 .0861 .075S .081 .0448 .0952 .0838 .0790 .0695 .0871 .0767 .082 •0453 .0963 .0847 .0799 .0703 .0881 .0776 .083 .0458 .0974 -0857 .0808 .0711 .0891 •0785 .084 .0463 .0985 .0867 .0817 .0719 .0901 .0794 .085 .0468 .0996 .0877 .0827 .0727 .0912 . 0805 .086 .0474 .1007 .0886 .0836 ■0735 .0922 .0812- .087 .0479 .1018 .0896 .0845 .0743 .0932 .0821 .088 .0484 .1029 .0906 .0854 .0751 .0942 .0830 .089 .0489 .1040 .0915 .0863 •0759 .0952 .o83» .090 .0494 .1051 .0925 .0872 .0767 .0962 .0847 .091 .0499 .1062 -0935 .0881 ■0775 .0972 .0856 .092 -0505 •1073 .0944 .0890 .0783 .0982 .0865 •093 .0510 .1084 .0954 .0900 .0791 .0992 .0874 .094 •0515 ■1095 .0964 .0909 .0800 .1002 .0883 •095 .0520 .1106 .0974 .0918 .0808 .1012 .0891 .096 •0525 .1117 .0983 .0927 .0816 .1022 .0899 .097 .0531 .1128 -0993 .0936 .0824 .1032 .0908 .098 •0536 -I139 .1003 .0946 .0832 .1043 .0917 .099 -0541 .1150 .1012 ■0955 .0840 -1053 .0926 .100 .0546 .1161 .1022 .0964 .0848 .1063 •0935 .101 -0551 .1171 .1032 .0973 .0856 -1073 .0944 .102 -0557 .1182 .1041 .0982 .0864 .1083 -0953 .103 .0562 -1 193 .1051 .0991 .0872 -1093 .0962 .104 .0567 .1204 .1060 .1000 .0880 .1103 .0971 .105 .0572 .1215 .1070 .1010 .0888 .1113 .0976 .106 •0577 .1226 .1080 .1019 .0896 .1123 .0988 .107 .0582 •1237 .1089 .1028 .0904 • -^-^zi .0997 .108 .0588 .1248 .1099 .1037 .0912 .1143 .1006 .109 .0593 .1259 .1108 .1046 .0920 .1153 • 1015 293 FOOD INSPECTION AND ANALYSIS. KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS FROM Vn-LOROCUJCIT)— {Continued). I 2 3 4 5 6 7 8 Phloroglucid Furfural. Arabinose. Araban. Xylose. Xylan. Pentose. Pentosan. O.IIO 0.0598 0. 1270 0.1118 0-1055 0.0928 0.1163 0.1023 i -III .0603 .1281 .1128 .1064 .0936 ■I173 .1032 .112 .0608 .1292 -II37 -1073 .0944 .1183 .1041 -"3 .0614 ■'^?>°3 .1147 .1082 .0952 -1 193 .1050 .114 .0619 -1314 .1156 .1091 .0960 .1203 -1059 .115 .0624 •1325 .1166 . IIOI .0968 .1213 .1067 .ii6 .0629 -1336 .1176 .1110 .0976 .1223 .1076 .117 .0634 -1347 .1185 .1119 .0984 -1233 .1085 .ii8 .0640 -1358 •II95 .1128 .0992 -1243 .1094 .119 .0645 .1369 .1204 ■ 1137 .1000 •1253 .1103 .120 .0650 .1380 .1214 .1146 .1008 .1263 .1111 .121 -0655 -I391 .1224 -IIS5 .1016 -1273 .1120 .122 .0660 .1402 -1233 .1164 .1024 .1283 .1129 .123 .0665 •I413 -1243 -1173 .1032 .1293 .1138 .124 .0671 .1424 -1253 .1182 .1040 -1303 .1147 -125 .0676 .1435 .1263 .1192 .1049 -1314 .1156 .126 .0681 .1446 .1272 .1201 -1057 -1324 .1165 .127 .0686 -1457 .1282 .1210 .1065 ■1334 .1174 .128 .0691 .1468 .1292 .1219 ..■1073 .1044 .I1S3 .129 .0697 ■1479 .1301 .1228 .1081 -1354 .1192 .130 .0702 .1490 .1311 •1237 .1089 -1364 .1201 -131 .0707 .1501 .1321 .1246 .1097 -1374 .1210 .132 .0712 .1512 ■ -^iio -1255 .1105 -1384 .1219 -'^33 .0717 -1523 -1340 .1264 .1113 -1394 .1227 .134 .0723 ■1534 ■ 1350 •1273 .1121 .1404 .1236 ■ 135 .0728 .1545 .1360 .1283 .1129 .1414 .1244 .136 -0733 -1556 .1369 .1292 -1137 .1424 -1253 .137 .0738 -1567 ■ 1379 .1301 -1 145 -1434 .1262 .138 .0743 ■1578 .1389 .1310 .1153 .1444 .1271 •139 .0748 .1589 .1398 .1319 .1161 -1454 .1280 .140 .0754 .1600 .1408 .1328 .1169 .1464 .1288 .141 -0759 .1611 .1418 -1337 .1177 -1474 .1297 .142 .0764 .1622 .1427 -1346 .1185 .1484 .1306 .143 .0769 ■1633 • 1437 -1355 -1 193 .1494 -I315 .144 .0774 .1644 -1447 -1364 .1201 -1504 .1324 .145 .0780 .1655 -1457 ■1374 .1209 -1515 ■-^333 .146 -0785 .1666 .1466 -1383 .1217 -1525 .1342 .147 .0790 .1677 .1476 -1392 .1225 -1535 •1351 .148 .0795 .1688 .i486 .1401 -1233 .1545 .1360 .149 .0800 .1699 ■ 1495 .1410 .1241 .1555 -1369 CEREALS, LEGUMES, l/EGETABLES, AND FRUITS. 291 KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS FROM PHLOROGLUCID— (Co«//;n Adulteration of Flour. — Besides the substitution of cheaper or inferior trades for those of higher quality, the fraudulent admixture of corn flour to wheat flour was at one time extensively practiced. This adulterant is best detected by the microscope (p. 281). Rye flour is often adulterated with cheap grades of wheat flour or middlings. These admixtures are detected by the Bamihl test (p. 322) and by microscopic examination of the residue after boiling with dilute acid (p. 306), noting especially the cross cells. Much of the so-called buckwheat flour consists of mixtures containing wheat or corn flour, or both. Rice flour is also used in pancake flours, although probably not to cheapen the product. Self-raising pancake flours are usually mixtures of two or more flours with leavening material. The microscopic characteristics of the starch grains and tissues, serve to identify the different flours present in such mixtures. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 315 Finely ground mineral adulterants are said to have been used in flours, but no authentic instance of this kind has come to the writer's knowledge. Any considerable admixture of such a nature would be manifest in the increased ash. Alum in Flour. — Alum was formerly used in Europe, both by miller and baker, to improve the appearance of inferior or slightly damaged flour, but now is rarely if ever employed, and the presence of notable quantities of aluminium compounds in flour or bread is usually due to alum baking powder. Detection.— Max 10 grams of the sample with 10 cc. of water and stir in i cc. of logwood tincture (5 grams logwood digested in 100 cc. alcohol) and i cc. of a saturated solution of ammonium carbonate. If the sample is pure, the color will be a faint brown or pink, but if alum is present, a distinct lavender-blue color is produced, which should remain after heating for two hours in the water-oven. Alum may also be detected by the ammonium chloride method, described on page 344. Bleaching of Flour. — In 1908 about 80% of the flour produced in the United States was bleached by nitrogen peroxide, but as a result of the enforcement of the federal law the practice has been largely discon- tinued. The gas is generated by electrical, chemical, or electro-chemical means, and is diluted with air before treatment of the flour. In the Alsop process, which is most commonly employed, it is formed by a flaming discharge of electricity, which causes the nitrogen and oxygen of the air to combine. Nitrogen peroxide destroys almost immediately the yellow color which is associated with the fat of the flour, thus increasing the whiteness of the product. It also forms with the moisture of the flour nitrous and nitric acids, the former (free or combined) being easy of detection. A considerable part of the nitrous nitrogen remains in yeast bread after baking and nearly all of it in soda biscuit. Bleaching also diminishes the iodine number of the fat, affects the quality of the gluten, and injures the flavor of the bread. Aging versus Bleaching. — Storage under proper conditions slowly whitens flour, improves its baking properties, increases its organic acidity, diminishes its water-content and brings about other changes not well understood. Bleaching immediately whitens flour but does not improve its baking properties, increase its organic acidity nor appreciably affect its water-content. It does, however, introduce nitrous 3i6 FOOD INSPECTION AND ANA L". SIS. and nitric acids. Often 2 parts of nitrous nitrogen per million i.re recoverable and sometimes 6 or 7 parts, but this gradually disappears so that after some months hardly a trace remains. The extent to which typical flours are whitened by aging and by bleaching so as to contain 2 parts of nitrous nitrogen per million is apparent from the gasoline color values in the following table by Winton: Minnesota, Hara Spring. Nebraska. Hard Winte-. Michigan, Soft Winter. Missouri, Soft Winter. 78% Patent. 22% Clear. 80% Patent. 20% Clear. 80% Patent. 20% Clear. • 40% Patent. 60% Clear. Gasoline color value of Unbleached: New -. . . 2.00 1.7S 1.20 0.72 0.60 0.44 0.30 0.30 2.00 1.82 1-34 0.88 0.66 0.54 0.50 0.50 2.63 2.12 1.36 0.70 O.So 0.46 0-34 0.24 2.50 2.17 1.68 0.82 o.So 0.48 0.40 0.36 1-43 1 . 22 0.80 0.56 0.40 0.26 0.20 0.18 1. 61 i.-;q 1.20 0.72 o.^o 0.3S 0.36 0.40 1-47 1.22 0.68 0.48 0.32 0.22 0.18 0.14 ' 60 Aged 10 weeks. . . . Aged 20 " . . . . Aged 30 " .... Bleached: New 0.88 0.52 0.40 0.26 0.24 0.16 Aged 10 weeks. . . . Aged 20 " Aged 30 " .... INSPECTION AND ANALYSIS OF FLOUR. In some of the larger cities, authorized inspectors are appointed by boards of trade to pass upon the quality of flour. To such inspectors dealers submit samples, which are gauged as to color, soundness, weight, etc., comparing them usually with a series of graded samples, and stamp- ing or branding them officially with the date as well as the grade. Market quotations also are based on the standard terms adopted. The names of the various grades differ with the locality. In St. Louis, the following names are adopted in order of their quality, viz.. Patent, Extra Fancy, Fancy, Choice, and Family. The grade or quality of flour is determined largely by its color, fine- ness, odor, absorption, and dough-making properties. Baking tests are also relied on to a considerable extent by millers and buyers. Of the chemical methods those for ash, protein, gluten, acidity, fat, and fiber are of chief importance. Fineness. — The granulation is determined by rubbing the flour between the thumb and fingers. A gritty flour is one that feels rough and granular, due to aggregates of cells with contents intact. Smooth flour, on th^ other hand, feels soft and slippery. It is so finely ground that the cells are isolated and often ruptured, thus liberating the contents. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 317 Pekar Color-test. — Place 10-15 grams of the flour on a rectangular glass plate, about 12 cm. long and 8 cm. wide, and pack on one side in a straight line by means of a flour trier. Treat the same amount of the standard flour used for comparison in the same manner, so that the straight edges of the two flours are adjacent. Carefully move one of the portions so as to be in contact with the other, and "slick" both with one stroke of the trier, in such a manner that the thickness of the layer diminishes from about 0.5 cm. on the middle of the plate to a thin film at the edge, and the line of demarcation between the two flours is distinct. Cut off the edges of the layer with the trier, so as to form a rectangle, and compare the color of the two flours. The difference in color becomes more apparent after carefully immersing the plate with the flour in water, and still more apparent after drying. Gasoline Color Value. — Winton Method. — Place 20 grams of the ilour in a wide-mouthed glass-stoppered bottle of about 120 cc. capacity and add 100 cc. of colorless gasoline. Stopper tightly and shake vigor- ously for five minutes. After standing sixteen hours, shake again for a few seconds until the flour has been loosened from the bottom of the the bottle and thoroughly mixed with the gasoline, then filter immediately through a dry ii-cm. paper, previously fitted to the funnel with water and thoroughly dried, into a flask, keeping the funnel covered with a watch-glass to prevent evaporation. In order to secure a clear filtrate, a certain quantity of the flour should be allowed to pass over on to the paper and the first portion of the filtrate passed through a second time. Determine the color value of the clear gasoline solution in a Schreiner colorimeter, using for comparison a 0.005% water solution of potassium chromate. This solution corresponds to a gasoline number of i.o and may be prepared by making 10 cc. of a 0.5% solution up to one liter. The colorimeter tube containing the gasoline solution should first be adjusted so as to read 50 mm., then the tube containing the standard chromate solution raised or lowered until the shades in both tubes match. The reading of the chromate solution, divided by the reading of the gasc'ine solution gives the gasoline color value. Absorption and Dough Test.— Stir 30 grams of the flour in a heavy coffee cup with 15 cc. of water by means of a spatula until a smooth ball of dough has been formed. If after standing two minutes the amount of water proves insufficient to thoroughly dough up the flour, repeat the operation, using 15.5 cc. of water, and, if necessary, continue to repeat until the quantity is found that will yield a stiff, but thoroughly 3l8 FOOD INSPECTION AND ANALYSIS. elastic dough. From the resuUs of this test, calculate the absorption of 3000 grams of flour in terms of cc. of water. The physical characters of the dough, such as color and elasticity, furnish valuable indications of the quality or grade of the flour. Expansion of Dough. — Rub to a smooth paste 3.5 grams of granu- lated sugar, 1.2 grams of salt, and 3 grams of compressed yeast, and thoroughly mix with 60 cc. of water at 35° C. Warm 100 grams of the flour in a shallow pan to 35° C, add to it the yeast mixture, mix with a spatula, and knead with the fingers until a smooth ball of dough has been formed. Drop the dough into a graduated, 500-cc. cylinder, pat down so as to force out the air, and note the volume of the mass. Place in a raising closet kept at 35° C. Read the volume at the end of the first hour and every half hour thereafter imtil the maximum is reached. Baking Tests.* — Koelner or Straight Dough Method. — This process yields a close-grained loaf of even texture, and serves well to determine the flavor and relative size of the loaf. Place 220 grams of the flour, previously warmed in a shallow pan, in a raising closet kept at 35° C, in a Koelner dough kneader, which has previously been warmed to 35° C. by means of water placed in the special compartment for this purpose. To the flour add 12 grams of sugar, 5 grams of salt, and 10 grams of compressed yeast, rubbed smooth and thoroughly mixed in a cup with 100 cc. of water at 35° C. Rinse the cup with sufficient water to make the total quantity required, as calcu- lated from the absorption test. This amount is usually about 87 cc. Adjust the blades of the kneader for mixing, and turn the crank at the rate of 90 revolutions per minute for 10 minutes. Adjust the blades for kneading, add 120 grams of flour, previously warmed to 35° C, and turn the crank for ten minutes at the rate of 60 revolutions per minute. Remove the dough immediately to a warmed plate, cut into two equal parts, mould the two separately, and place end to end in a warmed, greased, and tared baking tin measuring 27X6.3 cm. at the top, 25.4X5 cm. at the bottom, and 8.8 cm. deep — all inside measurements. Weigh the tin with dough, place a tin gauge across the top, and set the whole in the raising closet. After the dough has risen to the gauge, place the tin in a suitable oven heated to 200° C, and bake at 200 to 205° until 30 grams of water have been removed, which usually requires from 30 to 35 minutes. Break the loaf in two, and note the odor when hot and again when cold, also the flavor when cold. * Descriptions by Miss H. L. Wessling, Chicago Laboratory, Bur. of Chemistry. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 2>i() When thoroughly cool, determine the volume of the loaf as follows: cover the bottom of a box 7.6X12.7X28 cm., inside measurements, with flaxseed, place the loaf in the box, pour flaxseed without jarring into the box until filled, and strike off the surplus seed by means of a straight edge. Remove the seed from the box, weigh, and divide the weight by the weight of i cc. of the seed, as calculated from an actual weighing of the seed required to fill the box. Subtract this figure from the cubic contents of the box in cc, thus obtaining the volume of the loaf. Long Fermentation Method. — This method, used in some of the large mills in the northwest, differs from the Koelner method in that (i) a sponge is set, (2) the dough is kneaded twice, and (3) the dough is finally expanded to the limit. The bread is coarse in texture, but serves well to test the strength and flavor. To 255 grams of warmed flour contained in a jar or earthenware crock, add 3.5 grams of salt and 8.6 grams of compressed yeast, mixed thoroughly with 170 cc. of water at 35° C. Stir together until a soft sponge is formed, and keep in the raising closet, at 35° C, until the volume has been doubled, then mix with 85 grams of warmed flour, 12 grams of sugar, 6 grams of lard, and the remainder of the water, the total quantity for 340 grams of flour being calculated from the absorption test. Knead steadily for six minutes, transfer the dough to the jar or crock, and set it in the raising closet until it has again doubled its volume. Remove the dough to a warmed plate, knead lightly in the hands for a minute or two, then place in a warmed and greased standard baking tin, 16.8X8.8 cm. across the top, 14.9X6.9 cm. across the bottom, and 13.9 cm. deep, all inside measurements, with extensions of the metal at the top of the two sides. Prick the dough about a dozen times with a fine-pointed wire, and raise again in the closet, until the bubbles of gas just begin to break and form larger ones. This is a matter of judgment and can be learned only by experience. The dough must not be raised to its limit beforehand, but must be put in the oven at such a stage that with the additional rising in the oven it will have attained the maximum volume. Bake from 30 to 35 minutes, raising the temperature gradually from 180° C. at the beginning to 210° C. at the end. Determination of Moisture, Protein, Crude Fiber and Fat. Employ the methods described on pages 277 to 279. The crude fiber should be collected and weighed on a Gooch crucible. Determination of Ash.- — Char 5 grams of the flour in a flat-bottomed platinum dish heated on a piece of thin asbestos board over a Bunsen burner. 320 FOOD INSPECTION AND ANALYSIS. Complete the burning at dull redness, preferably in a muffle furnace. If the ash is black or dark gray add a few drops of nitric acid, evaporate to dryness on a water-bath and again heat at dull redness, repeating the treatment if necessary. Determination of Moist and Dry Gluten.* — Place 25 grams of the flour in a coffee cup, add 15 cc. of water at a temperature not to exceed 1 1^°, and work the mass into a ball with a spatula, taking care that none of it adheres to the dish. Allow the dough to stand one hour, then knead in a stream of cold water over a piece of bolting cloth held in place by two embroidery hoops, until the starch and soluble matters are removed. Place the gluten thus obtained in cold water, and allow to remain for one hour, after which press as dry as possible between the hands, roll into a ball, place in a tared flat-bottomed dish, and weigh as moist gluten. Spread the gluten out in the dish, dry for 24 hours in a boiling water-oven, and weigh again, thus obtaining the dry gluten. Determination of Alcohol - soluble Protein (Crude Gliadin.) — Chamberlain Method* — Digest 5 grams of the sample with 250 cc. of 70% (by vol.) alcohol for 24 hours, shaking every half hour during the first 8 hours. Filter through a dry paper, determine nitrogen in 100 cc. of the filtrate and multiply the result by 5.7. The amount of alcohol-soluble protein may also be expressed in terms of percentage of the total protein. This percentage is known by some authors as the " gliadin ratio." Determination of Salt-soluble Protein. — Chamberlain Method.'* — Digest 10 grams of the flour with 250 cc. of 5% potassium sulphate solution, as described under Alcohol-soluble Protein. Determine nitro- gen in 50 cc. of the filtrate, and multiply the result by 5.7. Determination of Acidity of Flour. — Titrate 100 cc. of the solution prepared as described for the determination of nitrites (p. 321), with tenth-normal sodium hydroxide solution, using phenolphthalein as indi- cator. If the distilled water used contains an appreciable amount of carbon dioxide, it should previously be boiled in a Jena flask until neutral but not long enough to dissolve alkali from the glass. Two hundred cc. of the boiled water should remain colorless on addition of phenolphthalein, hut should take on a distinct pink color when mixed with a single drop of tenth-normal alkali. Determination of Cold-water Extract. — Wanklyn Method. — Mix * U. S. Dept. cf Agric, Bur. <;f Chem., Bui. 81, p. 118. CEREALS, LEGUMES, KEGETyfBLES, AND FRUITS. 321 100 grams with distilled water in a graduated liter flask, shake frequently during six or eight hours and allow to stand over night. Decant on a filter, rejecting the first portions that run through, and evaporate 50 cc. of the clear filtrate to dryness in a tared metal dish on a water- bath. The weight of the dried residue multiplied by 20 gives the cold-water extract which, according to Wanklyn, should not exceed 5%. Determination of Iodine Number of the Fat. — Dry over sulphuric acid for three days sufficient flour to yield 0.2 to 0,25 gram of fat and extract for sixteen hours in a Johnson extractor with 25 cc. of absolute ether, into a tared 35-cc. flask. Drive off the ether and dry at 100° C. for fifteen-minute periods to constant weight, passing a current of dry hydrogen through the flask. Proceed according to the Hanus method, adding the chloroform and iodine solution directly to the flask, and breaking the flask within a wide-mouthed glass stoppered bottle for the final dilution and titration. Detection of Bleaching in Flour. — Place on the "slicked" surface of the flour a drop or two of a mLxture of equal parts of solutions (a) and (6), described in the following section. If the flour is unbleached and has not been stored under conditions permitting absorption of nitrous acid the liquid, which does not immediately soak into the flour, will remain colorless or nearly so, while if it is bleached it soon takes on a marked pink or crimson color, varying in degree with the extent of bleaching. A positive test should be supplemented by determinations of nitrous nitrogen and gasoline color value. Determination of Nitrous Nitrogen. — Griess-Ilosvay Method.^ — This method, conunonly employed for the determination of nitrites in water, is well adapted for the estimation of the extent to which flour has been bleached by nitrogen peroxide or nitrosyl chloride. I. Reagents. — {a) Sidphanilic Acid Solution. — Dissolve 0.5 gram of sulphanilic acid in 150 cc. of 20% acetic acid. (h) Alpha-na phtylamiiie Hydrochloride Solution. — Dissolve 0.2 gram of the salt in 150 cc. of 20% acetic acid with the aid of heat. (c) Standard Sodium Nitrite Solution. — Dissolve 0.1097 gram of dry C.P. silver nitrite in about 20 cc. of hot water, add 0.05 gram of C.P. sodium chloride, shake until the silver chloride flocks and make up to 1000 cc. Draw off 10 cc. of the clear solution and dilute to * Bull. chim. [2], 2, p. 317. 322 FOOD INSPECTION ^ND ANALYSIS. one liter. One cc. of this solution contains o.oooi mg. of nitrogen as nitrite. Suitable silver nitrite is on the market; it may also be prepaied as fol- lows : mix a warm concentrated solution of 8 parts of sodium nitrite with a warm concentrated solution of i6 parts of silver nitrate. When cool collect the precipitate on a Buchner funnel and wash with cold water. Dry quickly on a water-bath with as little exposure to light as possible. Long continued drying at ioo° C. causes it to slowly decompose. 2. Determination. — Weigh out 20 grams of the flour into an Erlen- meyer flask, add 200 cc. of water free from nitrites, previously heated to 40° C, close the flask with a rubber stopper, shake vigorously for five minutes, digest one hour at 40°, shaking every ten minutes, and filter on a dry folded filter free from nitrites. As the first portion of the filtrate is usually turbid, it should be returned to the filter and the operation re- peated until a clear liquid is secured. Dilute 50 cc. of the filtrate and also 50 cc. of the standard nitrite solution each with 50 cc. of water, add 2 cc. each of solutions (a) and (b) ; shake and allow to stand one hour to bring out the color. Compare the two solutions in a colorimeter (page 77). Divide the height of the column of the standard solution by that of the solution of the sample, thus obtaining the parts of nitrogen as nitrous acid (free or combined) per million of flour. Bamihl Test for Gluten (Modified by Winton*). — This test serves to detect wheat flour mixed with rye and other flours. Place a very small quantity of the flour (about 1.5 milligrams) on a microscope slide, add a drop of water containing 0.2 gram of water- soluble eosin in 1000 cc, and mix by means of a cover glass, holding the latter at first in such a manner that it is raised slightly above the slide, and taking care that none of the flour escapes from beneath it. Finally allow the cover glass to rest on the slide, and rub it back and forth until the gluten has collected into rolls. The operation should be carried out on a white paper so that the formation of gluten rolls can be noted. Wheat flour or other flours containing it yields by this treatment a copious amount of gluten, which absorbs the eosin with avidity, taking on a carmine color. Rye and corn flour yield only a trace of gluten, and buckwheat flour no appreciable amount. The preparations are best examined with the naked eye, thus gaining an idea of the amount of *U. S. Dept. of Agric, Bur. of Chem. , Bui. 122, p. 217. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. X2-> gluten present. Under the microscope traces of gluten, such as ara formed in rye flour, are so magnified as to be misleading. In case the flour is coarse, or contains a considerable amount of bran* elements, as is true of buckwheat flour and low grade wheat flour, the .est should be made after bolting, as the bran particles and coarse lumps interfere with the formation of gluten rolls. This test should be supplemented by microscopic examination of the untreated flour and also of the tissues, accumulated after boiling with i^% sulphviric acid as described on page 306. In the case of rye flour adult- erated with wheat flour the difference in the cross cells (pp. 306-308) should be especially noted; these, however, are present in considerable amount only in the cheaper grades of wheat flour. BREAD. Bread is a term broadly applied to any baked mixture of finely divided grain and water, whether or not other ingredients are used. Pilot, or ship bread, crackers, and unleavened bread, consist almost entirely of flour and water with a slight addition of salt. Similarly, corn bread or corn cake is frequently made exclusively from corn meal and water. In a narrower sense, however, bread is generally understood to mean the raised or leavened product, rendered light and porous by the aid of gas, which is generated either before or during baking. Commonly the gas employed is carbon dioxide, generated either by the fermentative action of yeast on the sugar of the dough, yielding both alcohol and gas, or by the agency of baking chemicals mixed with the dough, whereby an alkaline bicarbonate is decomposed by the action of an acid to produce the gas. Again, the gas may consist wholly or in part of ammonia, yielded by the vaporization during baking of ammo* nium carbonate mixed with the dough; and finally, the expansion dur* ing baking of the air itself confined in the dough may be the leavening agent, as in the case of puff paste and pie crust. Wheat flour is of chief value for bread on account of its high content of gluten, in which other cereals are lacking. In the preparation of ordinary white bread, the flour is mixed with water or milk, salt, and yeast, the materials are mingled thoroughly by kneading and allowed to remain for some time in a warm place, during which, by the vinous fermentation induced by the yeast, the mass "rises" or forms a light sponge, due ta "(the action of the gas on the glutinous dough. D'Jrins the subsequent process of baking, which should take place al 324 FOOD INSPECTION AND ANALYSIS. a temperature between 230° and 260° C, further expansion ensues, much of the water is driven off, and the porous mass sets to form the loaf, the outside of which is converted into a brown crust, due to the caramelizing of the dextrin and sugar into which the starch of the outer layers is con- verted. Among other changes that take place in the interior or "crumb'* during baking are (i) the partial breaking up of the starch grains, which, however, largely retain their identity, though in some degree distorted in shape; (2) somewhat obscure changes in the character of the proteins; and (3) partial oxidation of the oil or fat. The standard for judging the quality of commercial bread may wei be based on that of the best home -baked family loaf. The well-made loaf should possess an agreeable odor, and a sweet, nutty flavor, entirely free from mustiness. It should be well "raised," with a good crumbling fracture ; it should not be tough or soggy on the one hand (due to under- raising), nor extremely dry and spongy on the other (indicative of over- jaising). Over-raising, moreover, produces sourness, due to advanced lactic fermentation. Composition of Bread. — The following analyses made in the U. S. Bureau of Chemistry of common varieties of bread were summarized from Bulletin 13, part 9, averages of a number of analyses being given in each case: No. of Analyses. Moisture. Protein, NX6.2S. Protein. NX 5.70. 8 09 7 24 H IS 7 88 6 93 9 43 7 48 Ether Extract. Vienna bread Home-m-ide bread . Graham bread Rye bread Miscellaneous bread Biscuits or crackers. Rolls 9 7 9 48 38-71 33-02 34.80 33-42 34-41 7-13 27.98 8.87 7-94 S-93 8.63 7.60 10.34 8.20 1.06 1-95 2.03 0.66 1.48 8.67 3-41 Crude Fiber. Salt. Ash. Carbohy- drates, Excluding Fiber. Calculated Calories of Combus- tion. Vienna bread Home-made bread . Graham bread Rye bread Miscellaneous bread Biscuits or crackers. Rolls 0.62 0.24 1-13 0.62 0.30 0.47 0.60 0-57 0.56 0.69 I. GO 0.49 0.99 0.69 1-59 1.84 1 .00 T-57 1-31 53-72 56-75 53-40 56.21 56. 1 8 73-17 59.82 4435 4467 4473 4338 4429 4755 4538 In the examination of bread for its general quahty, without regard to its food value, much information may be gained by carefully observing the CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 325 physical characteristics of the loaf, its color, taste, odor, porosity, etc. In addition to such data, determination of moisture, ash, and acidity wiU usually suffice to enable the analyst to pass judgment on its whole- someness. The following summary gives such analytical data on upwards of fifty samples of bread, purchased from cheaper bakeries and stores, and examined in the author's laboratory. BREAD. Kind of Bread. No. of Analyses. Weight of Loaf in Grams. Water, Per Cent. Per Cent Ash in Terms of Solids. Acidity.* White Maximum Minimum Mean. . .- Graham Maximum Minimum Mean Whole wheat . . . . . Diabetic Muffins Rye "Black" German with seeds Brown "Knackerbrod" . . 44 653 126 430 500 367 420 507 445 194 1291 550 417 500 no 45.20 33- 00 40.72 45.20 40.10 41.50 45.10 47.00 48.20 47-15 47.00 42.30 48.10 8.00 1.83 0.60 0.85 1-55 0.96 1.26 1.20 2.20 1-15 2.13 2.20 0-95 3-50 1-94 6.2 1-3 2.6 4-2 2.1 3.5 1-7 10. o * Cubic centimeters of tenth-normal soda required to neutralize 10 grams of the fresh bread. Water in Bread. — The amount of water is of considerable importance, and, in the best bread, varies from 33 to 40 per cent. A larger content of water than 40% should be considered objectionable in a white bread, both on the ground of acting as a make weight, and because a large excess of moisture tends to cause the growth of mold. Acidity of Bread. — The degree of sourness of a sample of bread is one of the most important indications as to its quality, and is most readily obtained by rubbing up in water, by means of a pestle, 10 grams of the "crumb," and titrating with tenth-normal alkah, using phenolphthalein as an indicator. To neutralize the acidity of 10 grams of the normally sweet loaf, an average of 2 cc, of the standard alkali solution is required, corresponding to 0.72 gram of lactic acid per loaf of an average weight of 400 grams. The loaf exhibiting the maximum sourness or acidity in the above table required 10 cc. of standard alkali per 10 grams of bread, corresponding to 11. 61 grams lactic acid in the loaf of 1,291 grams. 326 FOOD INSPECTION JND ANALy^IS. Fat in Bread. — It is well known that the results of fat or ether extract as obtained by the ordinary method and expressed in most bread analyses are too low, being considerably less than the combined fat of the materials entering into its composition. This is probably due to the fact that during baking the fat particles are incrusted with insoluble matter, which protects them from the subsequent action of the ether. It is further claimed by some that the partial oxidation of the fat during baking has something to do with the lov/ results. No perfectly satisfactory improvement over the regular ether method for fat extraction in bread has been discovered, and therefore this method, as described elsewhere, is recommended. Adulteration of Bread. — The fraudulent addition of inert foreign ingredients to bread is almost never practiced, and is mainly of historic interest. Gypsum, chalk, bone ash, and various other minerals have been mentioned as possible adulterants, but the amount of any of these materials necessary to add for purposes of profit could scarcely be present without very apparent injury to the quality of the bread. Their presence in any considerable degree would be apparent in the abnormally high ash content of the bread. The employment of alum to ''improve" inferior or unsound flour has already been referred to, and, for the same purpose, sulphate of copper in small quantities is also said to have been used, enabhng the making of bread of fairly good appearance from flour that was distinctly damaged. Alum in Bread * is tested for by a modification of the logwood process described on page 315 as follows: 5 cc. of the logwood tincture and 5 cc. of the saturated ammonium carbonate solution are diluted to 100 cc, and the freshly prepared mixture poured over about 10 grams of the bread crumbs in a porcelain evaporating-dish. After standing a few minutes, as much as possible of the liquid is drained off, the bread is shghtly washed by one treatment with water, and dried in the water- oven. In presence of alum, a dark-blue color is given to the bread, which becomes deeper on drying. The color is proportional to the amount of alum present. If the sample is free from alum, the color varies from red to hght brown. The reagent solution must be freshly prepared. This test is not perfectly reHable in the case of very old or sour breads, which, have been known to give the color test with logwood in the absence of alum. * Jago on Bread, p. 634. CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 1^1 Copper Salts in Bread are detected in the ash by the same method as that used for canned goods (p. 918). Cake and Similar Preparations. — These differ from bread chiefly by the addition of considerable sugar, butter, spices, and other flavoring materials. In gingerbread, molasses is used as an important ingredient besides ginger. The adulterants of molasses, such as glucose, salts of tin, etc., would thus sometimes occur in gingerbread. In fact stannous chloride has been found in ginger cakes.* The following analyses of a few typical varieties of cakes are selected from Bulletin 13 of the Bureau of Chemistry: Moisture. Proteins, NX&.2S. Proteins, NX5-70. Ether Extract. Crude Fiber. Doughnuts . . Ginger snap^ Fruit cake Gingerbread. Cup cakes. . . Macaroons . . Jumbles 21.61 4.86 24.47 21.49 14.81 8.06 13-34 6.73 6.06 4-56 6.25 5-24 6.67 7.62 6-95 19-33 15-44 12-35 8.42 15-56 12.97 14.79 0.60 0.79 0.90 0.27 1. 41 1.04 Ash. Carbohy- drates Salt. Sugar. other than Fiber and Sugar. 0.03 1.28 50.64 0.47 28.66 24.90 0.28 9.48 52.46 0.34 32.48 30.89 0.07 58-77 10.89 0-39 16.60 46.31 Calculated Calories. Doughnuts . . Ginger snaps Fruit cake . . . Gingerbread. Cup cakes. . . Macaroons . . Jumbles .40 .82 1-55 1. 21 0.82 0.97 5529 4971 4757 5073 4835 5133 YEAST. The yeast plant is a fungus of the genus Saccharomyces, widely distributed through the vegetable kingdom and in the air. It is capable of rapid growth by the multiplication of its cells when present in a favorable medium, such as malt wort, and with propitious conditions of temperature, moisture, etc. Under such conditions, it forms a yellowish, viscous, frothy substance, the chief value of which, in the liquor industry, is the production of alcohol, while for bread-making, as a result of the same kind of fermentation, the end desired is the leavening of the doughy mass by the carbon dioxide liberated. See U. S. Dept. of Agric, Bur. of Chem., Bui. 13, p. 1369. 328 FOOD INSPECTION AND ANALYSIS. A vigorous, pure yeast which will "raise" quickly is a great preventive against sour bread, for not only is it comparatively free from the germs and products of lactic acid fermentation, but by doing its work quickly it enables the baker to check the fermentation or raising process before the lactic acid or sour decomposition is far advanced. Yeast most commonly used in bread-making is of the so-called " com- pressed" variety. The use of compressed yeast is almost universal for domestic purposes, and is more or less common in bakeries. A small amount of brewers' yeast in liquid form from beer wort is used, especially in the immediate neighborhood of breweries, and dry yeasts are used to some extent in localities so remote that fresh compressed yeast cannot readily be obtained. Compressed Yeast is a product of distilleries where malt and raw grain are fermented for spirits. Most of it comes from whisky wort, and some from the worts used in the manufacture of gin and other distilled liquors. Little if any of the commercial compressed yeast is made from beer wort yeast. In the manufacture of compressed yeast, the yeast floating on the top of the wort is separated by skimming, while that settling to the bottom is removed by running the wort into shallow settling trays. Top yeast is considered more desirable than bottom yeast for bread-making. The separated yeast is washed in cold water, and impurities are removed, either by sieving through silk or wire sieves, or by fractional precipitation while washing. The yeast, with or without the addition of starch, is finally pressed in bags in hydraulic presses, after which it is cut into cakes, packed in tin-foil, and kept in cold storage till distributed for use. Such yeast should be used when fresh, as it readily decomposes and soon becomes stale. When fresh, it should have a creamy, white color, uniform throughout, and should possess a fine, even texture; it should be moist without being slimy. It should quickly melt in the mouth without an acid taste. Its odor is characteristic, and should be some- what suggestive of the apple. It should never be "cheesy," such an odor indicating incipient decomposition, as does a dark or streaked color. Dry Yeast is prepared by mixing fresh yeast with starch or meal, molding into a stiff dough, and drying, either in the sun or at a moderate temperature under reduced pressure. Such yeast, when dry, is cut into cakes and put in packages. It will keep almost indefinitely. During the drying process, many of the yeast cells are rendered torpid and tem- porarily inert, and for this reason the dried yeast does not act so promptly CEREALS, LEGUMES, l^EGETABLES, AND FRUITS. 329 in leavening as does compressed or brewers' yeast, but when once it begins to act it is quite as efficacious. Composition of Yeast. — The following is the result of the analysis of under- fermentation yeast, after drying, by Nagele and Loew: Cellulose and mucilage 37 Albuminoids (mycroprotein, etc.) 36 " soluble in alcohol 9 Peptones (precipitable by subacetate of lead) ... 2 Fat 5 Extractive matters (leucin, glycerin, etc.) 4 Ash 7 100 Lintner gives the following average analyses of the ash of three samples of yeast, analyzed by him: Silica 1-34 Iron (FcjOa) o . 50 Lime (CaO) 5 .47 Sulphuric anhydride (SO3) o . 56 Magnesia (MgO) 6.12 Phosphoric anhydride (PjO 5) 50.60 Potash (KjO) and a little soda 33-49 98.08 Matthews and Scott give the following as the ash composition of yeast: Potassium phosphate 78 . 5 Magnesium phosphate 13.3 Calcium phosphate 6.8 Silica, alumina, etc 1.4 100. o Microscopical Examination of Yeast. — Mix a bit of the yeast in water on the glass slip till a milky fluid is formed, and stir in a drop of a very weak anilin dye solution, such as methyl violet, eosin, or fuch- 330 FOOD INSPECTION AND ANALYSIS. sin* Put on the cover-glass, and examine under the microscope. Living, active cells resist the stain, if the latter is dilute enough, and appear colorless or nearly so, while the decayed and lifeless cells are stained, and can easily be distinguished by their color. Yeast cells are circular or oval in shape, and vary from 0.007 to 0009 mm. in diameter. They are sometimes isolated, and sometimes grouped in colonies; each cell has an outer, mucilaginous coating or envelope. The interior, granu- lar mass or substance of the cell is the protoplasm, and within the protoplasm are frequently seen one or more circular empty spaces known as vacuoles. Yeast cells multiply by the process of budding. The decadence of yeast cells is marked by the increased size of vacuole, and by the thicken- ing of the cell wall. 'd^^ a b Fig. 68. — Sprouting Yeast-cells {Saccharomycgs cerevisia). (a, after Liirssen; b, aftei Hansen.) Yeast-testing. — Available Carbon Dioxide. — The value of yeast in bread-making depends on the amount of carbon dioxide which it is capa- ble of generating under given circumstances, hence the available carbon dioxide is the chief factor in gauging a yeast. There are various methods of determination, (i) either by measuring the volume of gas set free by the action of a weighed quantity of yeast in a sugar solution of known strength, kept for a fixed time at a fixed temperature (say 30°), or (2) by conducting the gas from such a fermenting solution through a weighed absorption bulb, containing potassium hydroxide and noting the increase in weight, or (3) by the more convenient method of Meissl as follows: A mixture is made of 400 grams pure, concentrated sugar, 25 grams ammonium phosphate, and 25 grams potassium phosphate. A small, wide-mouthed flask of about 100 cc. capacity is fitted with a doubly per- forated rubber stopper, having two tubes as shown, one of which is bent and passes nearly to the bottom of the flask, being fitted at the outer end with a rubber tube and glass plug, while the other is connected with a small calcium chloride tube. Measure 50 cc. of distilled water into * I gram crystallized fuchsin in 160 cc. water having i cc. alcohol. CEREALS, LEGUMES, {VEGETABLES, AND FRUITS. 331 this flask, and dissolve 4.5 grams of tlie above sugar phosphate mixture. Finally add i gram of the yeast to be tested, stir it well till there are no lumps, and cork the flask. Carefully weigh on a delicate balance the flask with its contents, and immerse in a water-bath at 30° C, keeping it at that temperature for six hours. At the end of this time, remove the flask from the bath, and immediately immerse in cold water to cool the contents. Remove the rubber tube with the glass plug, and by suction draw out the remaining carbon dioxide. Replace the plug, and having carefully wiped off the flask, again weigh. The loss in weight is due to carbon dioxide set free by the fer- mentation of the yeast. Starch in Compressed Yeast. — Potato, com, or tapioca starch has long been added to yeast before pressing, on the ground that the starch acts as a drier, producing a much cleaner product, and one that can be more readily and intimately mingled with the materials of the bread, besides enhancing the keeping qualities of the yeast, especially in warm weather. The quantities used vary from about 5% up to over 50%. Undoubtedly the larger amounts are added as a make weight. Some manufacturers use no starch whatever. The question has frequently been raised whether, with improved methods of manufacture, whereby yeast can be produced comparatively free from slime, and thus capable of pressure without the admixture of starch, the use of the latter should not be considered as an adulterant. Briant claims that the admixture of starch up to 5% increases rather than decreases the actual content of yeast, in that the starch abstracts moisture from the yeast cells themselves, the proportion of water being much smaller, and that of the yeast larger in the starch-mixed substance. T. J. Bryan,* on the other hand, finds that the addition of starch to yeast reduces the carbon dioxide value, and that the percentage reduction is greater than the percentage of starch present. His experiments further indicate that the keeping qualities of starch yeast is not greater, but actually less than that of pure yeast. Fig. (So. — Apparatus for Determining Leaven- ing Power of Yeast. * A. O. A. C. Proc. 1907, U. S. Dept. of Agric, Bur. of Chem., Bui. ii6, p. 25. 332 FOOD INSPECTION AND ANALYSIS. U. S. Rulings.*— I. The term "compressed yeast," without qualifica- tion, means distillers' yeast without admixture of starch. 2. If starch and distillers' yeast be mixed and compressed such product is misbranded if labeled or sold simply under the name "com- pressed yeast." Such a mixture or compound should be labeled "com- pressed yeast and starch." 3. It is unlawful to sell decomposed yeast under any label. CHEMICAL LEAVENING MATERIALS. Under this heading are included the various ingredients that enter into the mixtures commonly known as "baking powders" which have no food value in themselves, but are, strictly speaking, instruments or tools that by purely chemical reactions bring about, under certain con- ditions, the comparatively quick hberation of gas and the consequent aeration of biscuit, bread, and cake. Baking Powders and their Classification. — Formerly the housewife was accustomed to measure out in proper proportion a mixture of sour milk, or cream of tartar, with saleratus to produce quick aeration of bread. The modern baking powder is a natural outgrowth of the former practice, and has almost wholly displaced it, producing, as it does, a mixture ready for im-mediate use of an acid and an alkaHne constituent in proper pro- portion for chemical combination to form the gas. A third ingredient is however, generally considered as necessary to check deterioration, viz., a dry, inert material, which by absorbing moisture prevents the pre- mature chemical action between the reagents. Starch is nearly always used for this purpose, though sugar of milk has a limited use. The alkahne principle of nearly all baking powders is bicarbonate of soda, or saleratus. Baking powders are divided naturally into three main classes, with refer- ence to the acid principle: (i) Tartrate Powders, wherein the acid principle is (a) bitartrate of potassium or {h) tartaric acid, typified by the following reactions: 188 84 210 44 18 (a) KHC,HPe+ NaHC03 = KNaC,H,Oe+ CO3+ H^O Potassium Sodium Potassium Carbon Water bitartrate bicarbonate and sodium dioxide tartrate 150 168 230 88 (h) HX,HPe+ 2NaHC03 = Na2C,H,Oe.2H30+ 2CO3 Tartaric Sodium Sodium tartrate Carbon acid bicarbonate "dioxide * Food Inspection Decision, No. iii, Jan. 7, igio. CF.REy4LS, LEGUMES, VEGET/IBLES, AND FRUITS. ;i^:^ (2) Phosphate Powders, in which calcium acid phosphate is the acid principle : 234 168 136 142 88 36 CaH,(POj2+ 2NaHC03 = CiHP0,+Na2HP0,+ 2CO.+ 2H,0 Calcium Sodium Calcium Disodium Carbon Water acid phos- bicarbonate monohy- phosphate dioxide phate dr^gen phos- phate (3) "Alum Powders, '' wherein the acidity is due wholly or in part to sulphate of aluminum as it occurs in potash or ammonia alum, or in the double sulphates of aluminum and sodium.* Assuming burnt potash alum as the substance used, the reaction would be as follows: 516 504 156 426 174 264 K^Al^CSOJ.-f 6NaHC03 =Al2(OH)e+ 3Na,SO,+ K3SO4+ 6CO2 Burnt pot- Sodium Aluminum Sodium Potassium Carbon ash alum bicartaonate hydrate sulphate sulphate dioxide Naturally many baking powders of complex composition are met with, embodying various mixtures of the above classes. Composition of Various Baking Powders. — Following are analyses of typical baking powders of the above classes : f I. Cream of Tartar Baking Powder: Total carbon dioxide, CO2 13 • 21 Sodium oxide, NajO 13-58 Potassium oxide, K2O 14-93 Calcium oxide, CaO .18 Tartaric acid, C4H4O5 41 .60 Sulphuric acid, SO3 .10 Starch 7.42 Water of combination and association by difference. . . 8 . 98 100.00 Available carbon dioxide 12.58%. * It is probable that very little ammonia or potash alum is actually used at present in this class of powders. A ' product largely used is known in the trade as S. A. S. (sodium aluminum sulphate) and is a calcined double sulphate of aluminum and sodium. t Div. of Chem., Bui. 13, part 5, pp. 600, 604, and 606. 334 FOOD INSPECTION AND ANALYSIS. 2. Phosphate Baking Powder: Total carbon dioxide, CO2 I3'47 Sodium oxide, Na20 12 .66 Potassium oxide, KgO .31 Calcium oxide, CaO 10. 27 Phosphoric acid, P2O5 2 1 . 83 Starch 26.41 Water of combination and association by difference. . . 15-05 100.00 Available carbon dioxide 12.86%. 3. Alum Baking Powder: Total carbon dioxide, COj 9.45 Sodium oxide, NajO 9.52 Aluminum oxide, AI2O3 3 . 73 Ammonia, NH3 1.07 Sulphuric acid, SO3 10.71 Starch 43-25 Water of combination and association by difference . . 22.27 100.00 Available carbon dioxide 8.10%. Mixed Powders: Total carbon dioxide, CO, c 10.68 Sodium oxide, NaaO 14.04 Calcium oxide, CaO 1.29 Aluminum oxide, AI2O3 4-59 Ammonia, NH3 i . 13 Phosphoric acid, P2O5 3 . 38 Sulphuric acid, SO3 ii-57 Starch 42 . 93 Water of combination and association by difference . . 10.39 100.00 Available carbon dioxide 10.37%. The Adulteration of Baking Powder. — No substance that comes within the domain of food inspection is the subject of so much controversy CEREALS, LEGUMES, yEGETABLES, AND FRUITS. SiS as baking powder. Unless a specific law forbids the use of a particular ingredient or cla:s of ingredients, or in some manner regulates the labelling of the package, no baking powder of any kind can be considered adulterated under the general food law, unless it can be proved to be injurious to health, or unless it contain inert and useless mineral matter. As a matter of fact, the residue left in the bread by all classes of baking powder consists of one or more drugs recognized in the Pharmacopoeia, all of which in large quantity exercise well;marked toxic effects on the human system. Artificial digestion experiments, and physiological tests on the lower animals, using excessive doses of any of the above drugs, do not show the effect of the every-day use of baking powder in bread on the human system, and only a systematic examination of the effect of such use on large numbers of people can prove conclusively whether or not any one class of baking powders is harmful, and hence whether or not it should be classed as adulterated. Aside from the question of the harm- fulness of the acid ingredients, which is the subject of much controversy among rival manufacturers, there can be no doubt that such inert mineral substances as calcium sulphate, terra alba, or clay, which are entirely useless, and lower the strength of the powder, are to be considered in the light of adulterants. Traces of arsenic derived from the raw materials used in manufacture often occur in both alum and phosphate powders while lead is an acci- dental impurity of tartrate powders. Cream of Tartar. — Its Nature and Adulter ati on. -^Credjn of Tartar, or potassium bitartrate (KH5C4O6), is the purified product obtained by the recrystallization of the crude argols or lees deposited in the interior of wine casks. It is usually guaranteed 99% pure. The lees, or argols, consist chiefly of crude potassium bitartrate, which is present in the juice of the grape, but is insoluble in the alcohol formed in the fermentation, and is hence deposited. If, for the clarification of the wine, such substances as gypsum or plaster of Paris are used, tartrate of calcium will be found mixed with the bitartrate of potassium in the lees and also, if not eliminated, in the cream of tartar. Other common adulterants of cream of tartar are calcium acid phos- phate, gypsum or plaster of Paris, starch, and alum. Small amounts of lead from the tanks in which the cream of tartar is crystalhzed constitutes a common impurity. Potassium bitartrate is insoluble in alcohol, sparingly soluble in cold, and readily soluble in hot water. 536 FOOD INSPECTION ^ND ANALYSIS. CHEMICAL ANALYSIS OF BAKING CHEMICALS AND BAKING POWDERS. Cream of Tartar. — The degree of purity of commercial cream of tartar is best determined by weighing out exactly 0.188 gram of the sample, dissolving in hot water, and titrating with tenth-normal sodium hydroxide, using phenolphthalein as an indicator. If the article is pure, exactly 10 cc. of the standard alkali will be required for the titration. All the above-named adulterants, with the exception of alum, are either insol- uble, or sparingly soluble in hot water, and will indicate the impurity of the sample even before titration. If the adulterant be aium, the sample would go into solution in the water, but the alum would be precipitated by the sodium hydroxide, the precipitate being, however, soluble in an excess of the alkali. Sodium Bicarbonate on account of its cheapness is rarely adulterated, save by the occasional presence of common salt, an impurity incidental to its manufacture. The degree of purity of sodium bicarbonate is best ascertained by titration with standard acid, each cubic centimeter of tenth- normal acid being equivalent to 0.0084 grarfi of sodium bicarbonate. Determination of Total Carbon Dioxide. — Reagents. — Calcium Chloride. — This can be obtained in granulated form in pellets of abc ut the size of peas, specially prepared for moisture absorption. Soda Lime.* — ^To a kilogram of commercial sodium hydroxide, 500 to 600 cc. of water are added, and the mixture heated in an iron kettle to form a thin paste. While still hot, a kilogram of coarsely powdered quick- lime is added, stirring with an iron rod. The lime is slaked, and the whole mass heats and steams up. No outside heat is necessary at this stage, but the mass is stirred and the lumps broken up. As soon as cool, place the product in wide-mouthed bottles, and seal with parafi&n wax. The product should be slightly moist to give the best results. Hydrochloric Acid. — Specific gravity i.i. Sulphuric Acid. — Specific gravity 1.85. Potassium Hydroxide Solution. — Specific gravity 1.55. Two varieties of apparatus are in use for the d Jermina'ion of carbon dioxide. In one form the amount of carbon dioxide is obtained by dif- ference in weight of the apparatus, before and after ehmination of the gas. In the other, the gas driven out of a given weight of the sample is absorbed, and its amount calculated from the increase in weight of the * Benedict and Tower, Jour. Am. Chem. Soc, Vol. XXI, p. 396. CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 337 absorbent. Types of ihese varieties are the Geissler and the Knorr apparatus The Geissler Apparatus.- — This consists of a flask A, having a ground neck <2, and a flaring funnel-top A'. B is an elongated bulb, closed at the top by the hoiiow stopper K, and terminating below in the hollow stem B', which is accurately ground at b to fit the neck a. Fused into the bulb B is the tube C, and within this is the small tube D, open at the top and communicating directly with the hollow stem B'. gg are openings between B and C. £ is a fine glass tube, passing from the bottom of the hollow stem B' and to the height of a small protuberance e in the bottom of the funnel A', the construction being such that by turning the bulb and stem BB' in the neck a of the flask A the tube E may be opened or closed at the top. H is a side tube in the flask A, closed by the ground stopper h. The bulb B and the tube C are filled with strong sulphuric acid nearly to the top of the tube D, by passing through the neck at the top, which is then closed by the stopper K. About 0.5 gram of the dried sodium bicar- bonate, or I gram of the baking powder, is in- troduced into the flask A through the neck a from a weighing-tube or otherwise, so that its exact weight is known. The stem B' is then inserted, and ihe funnel-top A' is nearly filled with the hydrochloric acid, the tube e being closed. paratus or Alkalimeter. The entire apparatus is then weighed, after which the stem is turned to bring the protuberance e nearly opposite the tube E, uncovering it enough to allow the acid to pass slowly dowai the tube into the flask and upon the powder in the bottom of the flask. The carbon dioxide evolved passes through '.he opening / into the hollow stem B', thence up through he tube D, and down and up (as indicated by the arrows) through the sul- phuric acid which absorbs the moisture. Finally the gas passes out through the tube K. After the evolution of the gas has continued for two or three minutes, gentle heat is applied .0 the flask from a gas flame, and the solution is- FiG. 7'^. — Geissler's CO^ Ap« 338 FOOD INSPECTION AND ANALYSIS. brought to boiling, which is continued for a few minutes, during the latter portion of which the stopper h is removed, and the tubulure connected by rubber tubing with a system of two U tubes, one containing soda iime, and the other calcium chloride. The tube k is then connected with the aspirator, and a current of dried air is passed through the apparatus at the rate of about two bubbles per second, long enough to displace all the carbon dioxide. The rubber tubes are then disconnected, the stopper K is replaced, and the apparatus cooled to room temperature and weighed. The available carbon dioxide in baking powder is determined in the same manner as above, by simply substituting freshly boiled, distilled water for the hydrochloric acid in the funnel-top A'. The Knorr Apparatus {Modified). — ^The apparatus (Fig. 71) consists of (i) a flask, into which is introduced an accurately weighed amount of Fig. 71. — Modified Knorr Apparatus for Determining Carbon Dioxide. the dry samp^.e (0,5 to i gram of sodium bicarbonate or i to 2 grams of baking powder); (2) a funnel, the tube of which, provided with a stop- cock enters the stopper of the flask; (3) a soda lime tube, entering a stopper at the top of the funnel; (4) a Liebig condenser, connecting with a tube passing through the stopper of the flask; (5) a Geissler bulb, filled with the sulphuric acid; (6) a potash absorption-bulb, and (7) a calcium CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 339 chloride tube, which may if desired be replaced by a second sulphuric acid bulb. The potash absorption apparatus is accurately weighed before being connected up, and the funnel is nearly filled with the hy- drochloric acid reagent, after which the soda lime tube is attached. The calcium chloride tube is connected by a rubber tube with the aspirator, and a current of cold water is allowed to run through the outer Liebig condenser-tube. The stop-cock in the funnel-tube is first opened to allow the acid to slowly run into the flask, the flow being regulated to insure slow evolu- tion of the gas. The aspirator is then turned on so that about two bubbles of air per second pass through the apparatus, and gentle heat is apphed to the flask by the gas flame, the solution within being brought to boiling, and the boihng continued for several minutes after the vapor has begun to gather in the condenser. Prolonged boiling of the solution should be avoided, and in a series of tests the time of boiling should be precisely the same in all cases. After removing the flame, the flask is allowed to cool, the aspiration being continued. The absorption-tube is then removed and weighed at room temperature, the increase in weight being due to the carbon dioxide. The Available Carbonic Acid in Baking Powder is determined in the same manner as the total carbon dioxide, except that recently boiled, distilled water is substituted for the hydrochloric acid. Detection of Tartaric Acid.* — It is often desirable to test a " com- pound " cream of tartar, or a " cream of tartar substitute," or an adulterated sample made up largely of foreign ingredients, to see if any tartaric acid, free or combined, be present. The following test is applicable in presence of phosphates: If the substance to be tested is found to be free from starch, mix a little of the dry powder in a test-tube with a bit of dry resorcin, add a few drops of concentrated sulphuric acid, and heat slowly. A rose-red color indicates tartaric acid or a tartrate, the color being discharged on dilution with water. In case of baking powder, or a cream of tartar substitute containing starch, shake repeatedly from 3 to 5 grams of the sample with about * Wolff, Rev. Chim. Analyt. et appr. 4 (1899), p. 2631. j 340 FOOD INSPECTION JND ANALYSIS. 250 cc. of cold water in a large flask, allowing the insoluble portion to subside. Decant the solution through a filter, and evaporate the filtrate to dryness, after which test the dried residue or a portion thereof with resorcin and sulphuric acid as above described. Determination of Total Tartaric Acid. — Modified Heidenhain Method.^ — ^Applicable only in the absence of phosphates and salts of aluminum and calcium. Into a shallow porcelain dish, 6 inches in diameter, weigh out 2 grams of the material and sufficient potassium carbonate to combine with all tartaric acid not in the form of potassium bitartrate. Mix thoroughly with 15 cc. of cold water, and add 5 cc. of 99% acetic acid. Stir for half a minute with a glass rod bent near the end. Add 100 cc. of 95% alcohol, stir violently for five minutes, and allow to settle at least thirty minutes. Filter on a Gooch crucible with a thin layer of paper pulp, and wash with 95% alcohol until 2 cc. of the filtrate do not change the color of litmus tincture diluted with water. Place the precipitate in a small cas- serole, dissolve in 50 cc. of hot water, and add standard fifth-normal potas- sium hydroxide solution, leaving it still strongly acid. Boil for one minute. Finish the titration, using phenolphthalein as indicator, and correct the reading by adding 0.2 cc. One cc. of fifth-normal potassium hydroxide solution is equivalent to 0.026406 gram tartaric anhydride (C^H^OJ, 0.03001 gram tartaric acid (H2C^H^Oe), and 0.03763 gram potassium bitartrate (KHC.H.Oe)- The standard of the potassium hydroxide solution should be fixed by pure dry potassium bitartrate. The accuracy of this method is indicated by the agreement of the percentages of potassium bitartrate in cream of tartar powders containing no free tartaric acid, obtained by calculation from the tartaric acid, with those obtained by calculation from the potassium oxide. In presence of phosphates or of aluminum and calcium salts, the only satisfactory method of arriving at the amount of tartaric acid present is by difference, having determined or calculated the other ingredients. Kenrick's Polariscopic Methods. — Method i. {Applicable to Cream of Tartar).- — The method is based on. the fact that in the presence of excess of ammonia, the rotation of the solution is proportional to tbe * Provisional methods of the A. O. A. C, Bur. of Chem., Bui. 65, p. 104; Bui. 107 (rev.), P- 175- CERE.4LS, LEGUMES, VEGETABLES, AND FRUITS. 341 concentration of the tartaric acid, and is independent of the other bases and acids present. {a) The Substance is Completely Soluble in Dilute Ammonia. — A weighed quantity of the material containing not more than i gram tartaric acid is placed in a 25 cc. measuring flask, moistened with 3 or 4 cc. of water, and concentrated ammonia (sp. gr. 0.880) added in quantity suf- ficient to neutralize ail acids that may be present, and leave about i cc. in excess. The actual amount of the excess is not of importance, but a greater quantity than i cc. of free ammonia should be avoided. The solution is then made up to 25 cc. with water, filtered, if necessary, through a dry filter, and measured in a 20 cm. tube in the polarimctcr. The amount of tartaric acid (C4Hg06) in grams {y) in the material taken is given by the formula: y = o.oo5i9:xr, where x is the rotation in minutes. {b) The Substance is not Completely Soluble in Dilute Ammonia. — In this case calcium tartrate is probably present, and may be determined as follows: Treat i gram of the substance (or an amount containing not more than i gram of tartaric acid) in a small beaker with 15 cc. of water, and 10 drops of concentrated hydrochloric acid. Heat gently till both the potassium and calcium tartrates have passed into solution, and then, while still hot, add 2 cc. of concentrated ammonia (or enough to produce an ammoniacal smelling liquid) , and about o. i gram of sodium phosphate dissolved in a little water. Transfer to a 25-cc. measuring flask, cool, make up to the mark with water, filter through a dry filter, and polarize the filtrate in a 20-cm. tube. The tartaric acid is calculated from the formula given under (a). The precipitation of the calcium by means of sodium phosphate is not absolutely necessary, but when this is not done, in cases where the proportion of calcium in the sample is high, there is a great tendency for the calcium tartrate to crystallize out from the ammoniacal solution before the reading is made. The tartaric acid present as bitartrate of potash may be determined by proceeding as in (a), the calcium tartrate being practically insoluble in cold ammonia solution. The tartaric acid present as calcium tartrate is given, with sufficient accuracy for most purposes, by the difference between the results of (a) and (6). If more accurate results are required, the residue insoluble in 342 FOOD INSPECTION AND ANALYSIS. ammonia in {a) may be dissolved in a little hydrochloric acid and treated as above with sodium phosphate and ammonia. Method 2, {Applicable to Baking Powder and Cream of Tartar mixed with Substitutes). — Direct readings of rotation in ammoniacal solution are inadmissible in analyses of the substances of this class, on account of the influence of iron and aluminum on the rotation of tartaric acid, and on account of the small but unknown rotation of the trace of inverted starch. Accurate determinations, however, may be rnade in the presence of excess of ammonium molybdate in neutral solution. The latter substance has the property of greatly increasing the rotation of tartaric acid, so that by its use the small rotation of the inverted starch is made insignifi- cant. It is to be noted, however, that this increased rotation is very sensitive to the presence of alkali and acid, and is, moreover, modified by phosphates. It is therefore necessary, in the first place, to remove the phosphoric acid, and, secondly, to bring the solution to a definite state of neutrality. Both these results are attained by the following procedure, the details of which must be carefully adhered to: {a) Reagents. — The following solutions must be prepared, but need not be made up very accurately: Molybdate solution: 44 grams ammonium heptamolybdate in 250 cc. Citric acid solution: 50 grams citric acid in 506 cc. Magnesium sulphate solution : 60 grams MgS04 . 7H2O in 500 cc. Ammonia solution: 80 cc. concentrated ammonia (sp. gr. 0.880) in 500 cc. Hydrochloric acid: 60 cc. concentrated hydrochloric acid in 500 cc. Methyl orange solution: {b) Process. — An amount of material containing not more than 0.2 gram tatraric acid, not more than 0.3 gram alum, and not more than 0.3 gram calcium superphosphate, is accurately weighed, and placed in a dry flask. To this, 5 cc. of citric acid and 10 cc. of molybdate solution are added, and allowed to react with the substance for 10 or 15 minutes (with an occasional shake). Next, 5 cc. of magnesium sulphate solution are added, and 15 cc. of ammonia solution stirred in. After a few minutes (not more than one hour), the solution is filtered through a dry filter, a slight turbidity of the filtrate being disregarded. To 20 cc. of the filtrate are then added a few drops of methyl orange and hydrochloric acid, from a burette, till the pink color appears (2 or 3 drops too much or too little are of no consequence). Finally, 10 cc. more of the molybdate CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 'A3 solution are added to the pink solution, which now becomes colorless or pale yellow, and water is added to make up the volume to 50 cc. This solution, after filtering if necessary, is polarized in a 20-cm. tube. The amount of tartaric acid in grams (y) in the weight of substance originally taken is given by the following formula, in which x is the rotation in minutes: y — o.ooio86.v + o.ooi6oi\/.r. But if the rotation is not less than 40', the simpler formula, y == 0.007 5 + o-ooi 1 68.'v, may be employed. The following table gives the tartaric acid in grams for every 10 mmutes rotation : ■ Rotation in Minutes. Grams Tartaric Acid. Rotation in Minutes. Grams Tartaric Acid. 10 0.016 0.029 0.0415 0-0535 0.0657 0.0776 0.0895 O.1013 90 100 0.1130 0.1246 0-1365 0.1479 0-1595 0.1710 0.1825 20 30 40 50 60 70 80 1 10 I 20 130 140 150 Determination of Starch. — McGilVs Method'^ {Modified). — Digest I gram of the sample with 150 cc. of a cold 3% solution of hydrochloric acid during twenty-four hours, with occasional shaking. Filter through a tared Gooch crucible, wash first with water until neutral, then once with alcohol, and finally with ether. Dry at 110° C. for four hours, cool, and weigh. Burn off the starch, and again weigh. The difference in the two weights indicates the weight of the starch. The purity of the starch is insured by examination with the microscope. Acid Conversion Method. f — If the sample contains lime, mix 5 grams in a 500-cc. flask with 200 cc. of 3% hydrochloric acid, and let the mixture stand an hour with frequent shaking. Filter through a wetted 11 -cm. * Canada Inland Rev. Bui. 68, p. ;^^. t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 105; Bui. 107 rev., p. 176, 344 FOOD INSPECTION AND ANALYSIS. filter, wash with water, and transfer the starch by a wash-bottle from the filter-paper back into the original flask, using 200 cc. of water. If the sample be free from lime, weigh 5 grams directly into the 500-cc. flask with 200 cc. of water. In either case add 20 cc. of hydrochloric acid (specific gravity 1.125) and heat the flask in boihng water for 2^ hours, the flask being provided with a reflux condenser. Determine the dextrose, and from this the starch in the regular manner. Detection of Aluminum Salts.* — (a) In Baking Powder. — Appli- cable in presence of phosphates. Burn to an ash about 2 grams of the sample in a platinum dish. Extract with boiling water and filter. Add to the filtrate sufficient ammonium chloride solution to produce a distinct odor of ammonia. A flocculent precipitate indicates aluminum. In igniting, as above directed, sodium aluminate results from the more or less complete fusion. The reaction which occurs may be repre- sented as follows: Na,Al2044- 2NH,Cl-f 4H2O = Al,(OH)e+ 2NH,OH-f 2NaCl. Sodiuir. Ammonium Aluminum Ammonia Salt aluminate chloride hydroxide If any phosphate of lime be present, it will be insoluble in the solution of the ash. If phosphate of sodium or potassium be present, it will go inro solution, but will only precipitate out when an aluminum salt is also present on the addition of the ammonium chloride reagent. (h) In Cream of Tartar. — Mix about i gram of the sample with an equal quantity of sodium carbonate, bum to an ash, and proceed as in the case of baking powder (a). Determination of Alumina. — The above qualitative method with am- monium chloride may be made quantitative in presence of phosphates as follows: After carrying out the qualitative method as above directed, filter off the final precipitate, dissolve it in nitric acid, and test it for phos- phate with ammonium molybdate. If phosphates are found absent, proceed as before with a weighed amount of the sample and wash, ignite, and weigh the residue as AI2O3. If phosphate is found present in the ammonium chloride precipitate, proceed as before, igniting and weighing the total residue. Then deter- mine the P2O5 in the latter and subtract from the total. The difference will be the AI2O3. * Leach, 31st An. Rep. Mass. State Board of Health, 1899, p. 638. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 345 Determination of Lime. — 5 grams of the sample are treated in a 500 cc. graduated flask with 50 cc. of water and 25 cc. of concentrated hydrochloric acid. Add water to the mark, shake, and allow the starch to settle. Decant through a dry filter, and to 50 cc. of the filtrate add ammonia nearly to neutralization, an excess of ammonium acetate solution, and 4 cc. of 80% acetic acid, and heat at 50° C. Filter if necessary, and precipitate the lime with an excess of ammonium oxalate. Filter, wash, and ignite over a blast-lamp. Weigh as CaO. Determination of Potash and Soda.* — Weigh out 5 grams into a platinum dish, and incinerate in a muflie at a low heat. The charred mass is well rubbed up in a mortar, then boiled fifteen minutes with about 200 cc. of water, to which has been added a little hydrochloric acid. The whole is transferred to a 500-cc. flask, and, after cooling, made up to the mark and filtered. Of the filtered liquid 100 cc, representing i gram of the sample, are measured out, heated to boiling, and a slight excess of barium chloride solution added; then without filtering barium hydroxide is added in slight excess, the precipitate filtered off, and washed. To the filtrate is added a little ammonium hydroxide, and ammonium carbonate solution until the barium is pre- cipitated. This precipitate is filtered and washed, the filtrate evapo- rated to dryness, and carefully ignited below redness until all volatile matter is driven off. The residue is dissolved in a few cc. of water, and a few drops of ammonium carbonate solution added. The precipitate, if any, is removed by filtering and washing, and the filtrate evaporated in a small tared platinum dish, ignited below redness, and weighed. This gives the weight of the mixed chlorides. The residue is taken up with hot water, from 5 to 10 cc. of a 10% solution of platinic chloride added, and the whole evaporated to a sirupy consistency on the water- bath; it is then treated with 80% alcohol, the precipitate washed with 80% alcohol by decantation, transferred to a Gooch crucible, dried at 100° C, and weighed. The weight of the precipitate, multiplied by 0.19308, gives the weight of KoO, and by 0.3056 the equivalent amount of KCl. The weight of KCl found is subtracted from the weight of the mixed chloride, the remainder being NaCl, which, multiplied by 0.5300 gives the weight of NaoO in the sample. * U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 5, p. 593. 346 FOOD INSPECTION /iND /INALYSIS. Determination of Phosphoric Acid. — Method oj the A. O. A. C* — ► Mix 5 grams of the material with lo cc. of magnesium nitrate solution,t dry, ignite, and dissolve in hydrochloric acid. Take an aliquot part of the solution prepared above, corresponding to 0.25 gram, 0.50 gram, or I gram, neutralize with ammonia, and clear with a few drops of nitric acid. In case hydrochloric or sulphuric acid has been used as solvent^ add about 1 5 grams of dry ammonium nitrate, or a solution containing that amount. To the hot solution add 50 cc. of molybdic solution! for every decigram of P2O5 that is present. Digest at about 65° for an hour, filter,, and wash with cold water, or preferably ammonium nitrate solution.^ Test the filtrate for phosphoric acid by renewed digestion and addition of more molybdic solution. Dissolve the precipitate on the filter with ammonia and hot water and wash into a beaker to a bulk of not more than 100 cc. Nearly neutralize with hydrochloric acid, cool, and add magnesia mixture from a burette; add slowly (about i drop per second), stirring vigorously. After fifteen minutes add 30 cc. of ammonia solution of density 0.96. Let stand for some time; two hours is usually enough. Filter, wash with 2.5% NH3 until practically free from chlorides, ignite to whiteness or to a grayish white, and weigh. Determination of Sulphuric Acid. — Provisional Method A. O. A. C.\\ — ■ Boil 5 grams of the powder gently for one and one-half hours with a mix- ture of 300 cc. of water and 15 cc. of concentrated hydrochloric acid. Dilute to 500 cc, draw off an aHquot portion of 100 cc, dilute considerably, precipitate with barium chloride, filter through a Gooch crucible, ignite, and weigh. Direct solution of the material without burning the organic matter was proposed by Crampton.^f Determination of Ammonia (present in the form of ammonia alum or ammonium carbonate). Mix 5 grams of the sample with 200 cc. of water, and add an excess of sodium hydroxide. Distil into standard acid, and determine the ammonia by titration. Detection and Determination of Arsenic. — Proceed according to tha Marsh or Sanger-Black-Gutzeit method without preliminary treatment (page 75)- * U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 12; Bui. 107 (rev.), p- 4- t Prepared as follows: Dissolve 80 grams calcined magnesia in nitric acid, avoiding an excess of acid, then add a little calcined magnesia in excess, boil, filter from the excess of magnesia, ferric oxide, etc., and dilute with water to 500 cc. \ Reagent No. 53. § Prepared by dissolving 100 grams of ammonium nitrate, Reagent No. 54, in i liter of "water. U U. S. Dept, of Agric, Bur. of Chem., Bui. 65, p. 107; Bui. 107 (rev.), p. 178. % U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 5, p. 596. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 347 SEMOLINA, MACARONI, AND EDIBLE PASTES. Semolina is the coarse meal ground from certain varieties of hard or " durum " wheats, grown originally in Italy, Sicily, and Russia, but at present in France and certain parts of the United States and Canada. This hard wheat is high in gluten, and especially adapted for the prepara- tion of macaroni and the various pastes. A peculiar process is employed in preparing the wheat, whereby the husk is removed by wetting, heating, grinding, and sifting, the resulting meal or semolina, being in the form of small, round, glazed granules. Italian Pastes. — Semolina furnishes the basis of the Italian edible pastes, being mixed with warm water, kneaded, and molded into various forms, either by pressure through holes in an iron plate, or otherwise, and finally dried. In parts of Italy juices of carrots, onions, and other vegetables are said to be mingled with the paste, but for local consumption only. Saffron is sometimes added to pastes for the purpose, so it is claimed, of imparting a spicy flavor, although the quantity used is often so small as to be apparent only to the eye, thus indicating that the real object of its addition is to impart a color in imitation of an egg paste. Macaroni is the larger of the slender-tube or pipe-shaped products; vermicelli is the worm-shaped variety, produced when the holes in the plate are very small; spaghetti is the term applied to the cord-like paste intermediate in size between the others. A variety of Italian pastes or pates is made by rolling the kneaded semolina into thin sheets, and cutting out in shapes of animals, letters of the alphabet, etc. The composition of some of these products is as follows: No. of Samples. Water. Protein. Fat. Total Carbohy- drates. Crude Fiber. Ash. Fuel Value per Pound. Cal's. Semolina *.. Macaroni f . Noodles t. - - Spaghetti t • Vermicelli f- 3 15 10.50 10.3 10.7 10.6 II. o 11.96 13-4 II. 7 12. 1 10.9 0.60 0.9 I.O 0.4 2.0 75-79 74-1 75-6 76.3 72.0 0.50 0.4 0.4 0-65 1-3 i.o 0.6 4-1 1665 1665 1660 1625 ♦Balland. t Atwater and Bryant. Noodles are a strap-shaped form of paste made in German house- holds as well as in factories. True, or egg-noodles, contain a certain percentage of eggs, while water-noodles are practically the same in com- position as Italian pastes. The difference in composition between water- 348 FOOD INSPECTION AND ^N^ LYSIS. noodles and noodles made with different numbers of eggs or egg yolks per German pound of flour, is shown by the analyses of Juckenack and Pasternack* given in the following table :t h Composition of the Dry Matter. Composition of the Dry Matter. 1^ 1 B u si pp. Ash. Total Phos- phoric Acid. Lecithin Phos- phoric Acid. Ether Extract Protein NX6i Ash. Total Phos.- phoric Acid. Lecithin Phos- phoric Acid. Ether Extract Protein NX6i % % % % % % % % % % o 0.460 0.2300 0.0225 0.66 12.00 0.460 0.230c 0.0225 0.66 12.03 I 0-565 0.2716 0.05131 1.56 12.99 I 0.488 0. 2720 0.0518 1-57 12-37 2 0.664 O.3110 0.0786 2.42 13-92 2 0.516 0.3127 0.0801 2.47 12-73 3 * 0-758 * 0.3482 * 0.1044 * 3-24 * 14-81 * 3 * 0-542 * 0-3520 * 0.1075 * 3-33 * 13.07 * 12 1.426 0.6123 0.2875 7.94 21 .09 12 0-745 0-6533 O.3171 8.64 15-71 From these results it appears that the percentages of ash, total phos- phoric acid, and protein are appreciably increased by the addition of each egg or egg yolk, while the percentages of lecithin-phosphoric acid and ether extract are more than doubled by the addition of the first egg, and are increased in corresponding proportion by the addition of two or more eggs. The German Association of Food Chemists require that commercial egg-noodles contain at least 0.045% ^^ lecithin-phosphoric acid, and 2.00% of ether extract, corresponding to the minimum in noodles with two eggs per half kilogram of flour. Spaeth J considers that if the ether extract of noodles has an iodine number over 98, it is safe to assume that they contain no eggs or only traces. In interpreting the results of analysis it should be remembered that fat may have been introduced in some form other than in eggs, and that the lecithin-phosphoric acid diminishes somewhat on long standing. Allowance should also be made for the variation in co.Trposition of the eggs and flour. Of 22 brands of American noodles examined by Winton and Bailey§ only 5 appeared to be made with eggs; the lecithin-phosphoric acid in * Zeits. Unters. Nahr. Genuss., 3, 1900, p. 13; 8, 1904, p. 94. t The German pound is approximately 46S grams; the avoirdupois pound is 454 grams. X Forsch. iiber Lebensm., 3, 1896, p. 49. § Jour. Am. Chem. Soc. 1905, '37, p. 137; Rep. Conn. Exp. Sta., 1904, p. 138. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 349 these ranged from 0.036 to 0.058, and the ether extract from 1.83 to 2.33 per cent, while in the other samples the lecithin-phosphoric ranged from 0.015 to 0.032 and the ether extract from 0.28 to 2.50 per cent. Adulteration of Pastes. — Rice, corn, and potato flours have been used in the preparation of the cheaper varieties of semolina, but rarely in this country. A more common form of adulteration is the substitution of water-noodles for egg-noodles, artificial colors being used to carry out the deception. Substitutions of this kind are detected by determina- tions of lecithin-phosphoric acid and ether extract, supplemented by tests for artificial colors. Shredded Wheat is a whole-wheat preparation, put out in the form of light biscuits built up of fine porous threads, not unlike those of vermi- celH. The wheat, softened by boiling, is shredded by passing through a peculiar- machine, after which the biscuits are made by lightly putting together the threads and by final baking. The comparative composition of shredded wheat and of typical whole wheat is thus shown by Wiley:* Constituents. Shredded Biscuit. Per Cent. Typical Wheat. Per Cent. Moisture Proteins 10.57 12.06 1-03 2.65 2. 58 71. II 10.60 12.25 1-75 1-75 2.40 71-25 Ether extract Ash Crude fiber. . . Carbohydrates other than fiber ANALYSIS OF PASTES, Determination of Lecithin-phosphoric Acid. — Juckenack^s Melhod.f — Extract 30 grams of the finely ground material for 10 hours with abso- lute alcohol in a Soxhlet extractor at a temperature, inside the extractor, not below 55°-6o° C. The extraction flask should be provided with a small quantity of pumice stone to prevent bumping during the boiling, and the extractor enclosed by asbestos paper, if the desired temperature is not readily maintained. After the extraction is completed, add 5 cc. of alco- holic solution of potash (prepared by dissolving 40 grams of phosphorus- free caustic potash in 1000 cc. alcohol), and distil off all the alcohol. Transfer the residue to a platinum dish by means of hot water, evaporate to dryness on a water bath, and char over asbestos. Treat the charred ' — — -^_ I * U. S. Dept. of Agric, Bur. of Chem., Bui. 13, p. 1337. t Zeits. Unters. Nahr. Genuss., 3, 1900, p. 13. 350 FOOD INSPECTION AND ANALYSIS. mass with dilute nitric acid, filter, and wash with water. Return the residue with the paper to the platinum dish, and burn to a white ash. Treat again with nitric acid, filter and wash, uniting the filtrates. Determine phosphoric acid by the usual method. Detection of Artificial Colors in Pastes. — The following colors have been used in noodles and other pastes: turmeric, saffron, annatto, naphthol yellow (Martins yellow), naphthol yellow S, picric acid, aurantia, Victoria yellow, tartrazine, metanil yellow, azo yellow, gold yellow, and quinoline yellow. Of these naphthol yellow, picric acid, metanil yellow, and Victoria yellow are injurious to health, and their use is illegal in European countries as well as in the United States. Fortunately, they are rarely found in the products now on the market. The detection of artificial colors is complicated by the presence of the natural coloring matter of the flour and the lutein of eggs. These are conveniently extracted by ether, which does not remove the artificial colors, although most of them unmixed dissolve freely in this solvent. Juckenack's Method* — Thoroughly shake two portions of the finely ground material, each of about lo grams, in test tubes with 15 cc. of ether and 15 cc. of 70% alcohol respectively, and allow to stand 12 hours. (a) If the ether remains uncolored or only slightly tinted and the material below it remains yellow, while the alcohol is distinctly colored and the material is decolorized, a foreign dye is indicated. (b) If both ether and alcohol are colored, either (i) lutein (egg color) alone, or (2) this with a foreign dye is present. 1. Treat a portion of the ether solution with dilute nitrous acid, according to Weyl. If the ether is not completely decolorized, a foreign dye is present. 2. If the deposit of material below the alcohol is decolorized, while that below the ether is colored, tests should be made for foreign dyes as follows: Shake the portion previously treated with ether with three or more fresh portions of the same solvent, until no more color is extracted, and then shake the residue with 70% alcohol and allow to stand 12 hours. After filtering, concentrate the solution slightly, acidify with hydrochloric acid, boil with sensitized wool, and identify the color in the usual manner (page 801). SchlegeVs Method.^ — Extract 100 grams of the finely powdered material "with ether in a continuous extraction apparatus, and shake the residue * Zeits. Unters. Nahr. Genuss., 3, 1900, p. i. t Untersuchungsanstalt, Niirnberg, Ber,, 1906, p. 24. CEREALS, LEGUMES, l^EGETABLES, AND FRUITS. 351 at frequent intervals for half a day with a mixture of 140 cc. of alcohol, 5 cc. of ammonia, and 105 cc, water. Filter, evaporate to remove alcohol and ammonia, acidify slightly with hydrochloric acid, and again filter. Boil the filtrate with sensitized wool, and identify the color on the dyed fiber by the usual tests (page 801). Fresenius Method."^ — Extract 20 to 40 grams of the powdered material with ether in a continuous extraction apparatus. Dry the residue to remove ether, shake for 15 minutes with 120 cc. of 60% acetone, and allow to stand 12 to 24 hours. Filter, evaporate until the acetone is removed, and divide into two portions, a larger and a smaller. To the larger portion add sufficient acetic acid to dissolve flocks, and boil with sensitized wool. Remove natural coloring matter from the wool by boiling in dilute acetic acid. If after this treatment the wool is dyed the presence of a foreign color is indicated, which may be identified by the usual tests. To the smaller portion of the aqueous solution, obtained after removal of the acetone as above described, add an equal volume of alcohol, heat to dissolve flocks, divide into four portions, and apply special tests to three of these, reserving the fourth for comparison. The natural color of the flour is decolorized by hydrochloric acid, intensified by ammonia, but not affected by stannous chloride, even on heating. Saffron reacts in a similar manner, but is only slightly bleached by the acid, and is not affected by the other two reagents. Piutti and Bentivoglio Method.-f — ^This method is especially designed to detect the four colors forbidden by Italian law, and to distinguish these from naphthol yellow S. Add 50 grams of the paste to 500 cc. of boiling water, made alkaline with 2 cc. of concentrated ammonia water, add 60 to 70 cc. of alcohol, and continue the boiling 40 minutes. After filtering, acidify the hquid with 2 to 3 cc. of dilute hydrochloric acid and boil with 5 to 6 strands of sensi- tized wool, each strand weighing about 0.5 gram. Wash the wool, dissolve the color in dilute ammonia, and repeat the dyeing. After dissolving a second time in ammonia, evaporate the solution of the dye to dryness, avoiding as far as possible the formation of a skin, and take up the residue in water. If a skin has formed, filter and test the insoluble matter for metanil yellow with dilute hydrochloric acid, and for picric acid with ammonium sulphide. * Zeits. Unters. Nahr. Genuss., 13, 1907, p. 132. t Gaz. chim. Ital. 36, II, 1806, p. 385. 352 FOOD INSPECTION AND ANALYSIS. To I cc. of the filtrate add stannous chloride solution and a little sodium hydroxide, or preferably sodium ethylate. If no red color forms, nitro-colors are absent; if, also, in another portion dilute hydrochloric acid produces no violet color, thus showing the absence of metanil yellow, no further test is necessary. In the presence of these colors, acidify the remainder of the solution with acetic acid, shake violently with carbon tetrachloride, and identify the color according to the following scheme: A. Color dissolves in carbon tetrachloride to colorless solution. Extract with very dilute ammonia, concentrate and divide into two parts. 1. Acidify with hydrochloric acid, and add i to 2 drops of stannous chloride and ammonia in excess. A rose colored solution and precipi- tate form Naphthol yellow. 2. Acidify slightly with hydrochloric acid, add a little zinc dust and stir. Solution becomes rose-violet Victoria yellow. B. Color is insoluble in carbon tetrachloride. Evaporate to dryness on water-bath, take up in water and divide into three parts. 1. Hydrochloric acid produces a violet coloration Metanil yellow. 2. Ammonium sulphide produces a red brown coloration. Picric acid. 3. Stir on a water-bath with zinc dust and ammonia, filter, treat with zinc dust and hydrochloric acid and again filter, {a) Potassium hydroxide produces a yellow coloration, and {h) ferric chloride an orange coloration. Naphthol yellow S, Schmitz-Dumont Test for Tropeolins.^— Moisten a small portion of the material with a few drops of dilute hydrochloric acid. The formation of a reddish or bluish color shows the presence of an azo color or some Dther coal-tar color. Test for Turmeric. — Extract the color from the ground material by alcohol and identify by the boric acid test (page 791). PREPARED CEREAL BREAKFAST FOODS. The large number and variety of these preparations now on the market testify to the fact that the breakfast cereal forms a most important, as well as considerable, portion of our food supply. These foods are generally prepared from wheat, oats, and corn, and are, as a rule, remarkably pure and free from adulteration, though the food value of different varieties * Zeits. offent. Chem., 8, IQ02, p. 424. CEREALS, LEGUMES, yEGETABLES, AND FRUITS, 353: is often grossly misstated by their manufacturers. Formerly the break- fast food consisted entirely of the coarsely ground, generally decorticated, raw cereal grain, and required a long period of cooking to prepare it for use. At present many of the oat products, and to some extent also those of corn, rice, and wheat, are subjected to a more or less preliminary cook- ing and drying, whereby they are capable of being prepared for use in: a much shorter time, and their keeping qualities are enhanced. The so-called rolled oats are prepared by softening the grains through steam- ing, after which they are crushed between rollers and afterwards dried. The steaming process is a typical one for various other cereals, though in some cases the heating consists in baking or kiln drying. The effect of the preliminary cooking on the finished product varies somewhat according to whether dry or moist heat has been apphed, and is chiefly- noticeable in the altered character of the carbohydrates. In all cases the starch is rendered more soluble, whether by the conversion of a portion into dextrin and dextrose, or by a simple breaking dowii' of the starch grains, as in the case of bread in baking. In spite of the seemingly endless variety of the package cereals, they~ divide themselves as a matter of fact into a ver/ few well-defined classes y the members of which differ but little from each other except in name. First there are the raw cereal grains of the oat, wheat, and corn, pre- pared by simple crushing to various degrees of fineness, after decorticating; next comes the classes of partially cooked preparations of each of these: grains, appearing in various forms of "flakes," "granules," "grits," etc., and again a class known as malted cereals, in which the moist, ground grain is mixed with malted barley, and, by controlling the temperature, a portion of the starch is converted to maltose and dextrin, after which the mixture is crushed between hot rollers and dried. In the preparation of most of the corn breakfast products, such as'. samp and hominy, it is customary to remove the germ, which contains, the oil and fat, lest the tendency of the latter to become rancid should result in the deterioration of the food. In wheat foods the germ is less; often removed, and rarely, if ever, in oat preparations. The amount of fat found in the prepared cereal food as compared with that in the whole grain is of interest in this connection. Composition of Some of the Common Breakfast Cereals. — The follow- ing analyses will serve to typify the various classes of these preparations as they appear on the market: 554 FOOD INSPECTION ^ND ANy4 LYSIS. Wheat.* Wheatena Pettijohn's breakfast food. . Farina Cracked wheat Ralston's breakfast food. . . Fould's wheat germ Oats.* Quaker Hornby's Buckeye Corn. Cerealine * ■> Velvet meal * Hecker's hominy t Nichols' snow-white sampf. MlSCELLANPOUS.f Brittle bits Force Grape-nuts Ralston's health barley food . . 6.65 9-51 10.94 9-30 9.72 10.13 7.40 7-63 7-54 9-55 9.80 II. I 10.3 6.9 5-4 4.2 10.8 Carbohydrates. 2.28 i4.:t7 75 l-45'lo 5676 1.56 10. 9075 2.22 I2.6o'94 i.9o'i5.io'7i 1.46^13.3073 6.08 17.20 66 7.35I17.82J65 8.3016.8965 1.24 2.32 0-3 0-3 0-5 1.4 I.I i.o 9.9078 6.75 80 9-4 14. 1 II. 6 12.6 10.7 3-9 ■5^ 70.50 72-15 72.12 69.63 65.60 69-35 1.6 64.65 1.3 62.74 3-3 60.90 7-1 70-93 77-77 1.22 2.01 0-59 1.49 1-55 1.40 1.43 1-35 0.72 0.96 0.4 0.4 1.9 0.6 1.28 1.52 0.69 1 .46 1-53 n E ^ 0-3^3 0.231 0-153 0-333 0-343 o. ^26 1.67 0.341 1-730.443 1.72 0.416 0.56 0.60 0.2 0-3 i-S 2.8 .192 .185 4343 4174 4051 4236 4158 4087 4673 4756 4526 4542 3660 * Analyses made by Slosson, Wyoming Exp. Sta., Bui. 33. t Analyses made by Merrill and Mansfield, Maine Exp, Sta., Bui. 84. The methods of analysis employed for these preparations are the same as for ordinary cereals (p. 277), the sample being ground fine enough to pass through a i-mm. sieve. PREPARED FOODS FOR INFANTS AND INVALIDS. In dealing with the composition and analysis of this class of proprie- tary foods more than ordinary care is necessary, in view of the fact that one or another of these preparations are frequently prescribed for the exclusive diet of those whose very life may depend on the character and suitability of the food to the case in hand. Many of these foods do, as a matter of fact, honestly fulfil the claims of their manufacturers, but others fall far short of so doing, so that it is hardly safe to use them unless some intelligent idea of their composition can be gained. It is not, as a rule, within the province of the analyst to furnish an opinion regarding the adaptability of a certain food to the requirements of an infant or invalid, but rather to provide the necessary data whereon such an opinion may be intelligently based. CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 355 A simple statement of moisture, fat, protein, carbohydrates (by dif- ference), and ash, which in the case of ordinary foods would often be sufficient, would be obviously inadequate in expressing the analysis of an infant food, since it is of much more vital importance than in other foods to know the solubility of the food itself, and, to as great an extent as possible, the character of the carbohydrates. The chief ingredients of many of these preparations are wheat, or mixed cereals high in starch. Many of the foods are, according to the directions, to be used practically without cooking, but by simply mixing with milk or water, and, in some cases, bringing to the boiling-point. Hence the degree of conversion which the raw starch has undergone in the process of manufacture of the food should, if possible, be ascertained as a prime factor in judging of its character and adaptability to the needs of the young child and of the sick. Incidentally it should be said that few if any of the infant foods, even those whose high character has long been established by continued trial, conform very closely to the composi- tion of woman's milk, which was long accepted as the true standard on which to base their efficiency. Hence it is no easy task to pass judgment on a particular food from its chemical composition alone without trial, nor is it right to unqualifiedly condemn in all cases food high in insoluble carbohydrates, since there are undoubtedly many instances in which such foods are successfully used. Classification and Preparation of Infants' Foods. — These foods may for convenience be divided into two main classes, viz., farinaceous foods, or those which are prepared wholly or chiefly from one or more cereal grains, and lactated foods, or those in which cow's milk forms the basis, but which may contain in addition thereto various other substances, such as cereals, sugars, etc. The farinaceous foods, which are usually directed to be mixed with milk before using, may be further subdivided into {a) those that consist chiefly of unconverted starch, {h) those whose starch has been nearly all hydrolyzed to soluble form in the process of manufacture, and (c) those which contain much unconverted starch, but in addition thereto diastase or some other ferment, which, when the food is mixed with warm water or milk, is supposed to convert all the starch to soluble form. The unconverted starch foods are nearly all made up of baked dry flour, chiefly that of wheat, but sometimes a mixture of cereals (as oats, barley, and wheat) and sometimes oats or barley alone. The baking 35^ FOOD INSPECTION A\D ANALYSIS. breaks down to some extent the starch grains, as in the case of bread or crackers, but does not actually convert much of it to sugar. The soluble farinaceous foods are usually prepared somewhat as follows: A mixture of ground wheat and barley malt (with sometimes a little wheat bran) is mixed with water to form a paste, and a little bicar- bonate of potash added. The mixture is heated at 65° C. for sufficient time to convert the starch, after which it is exhausted with warm water, the extract being strained, and the filtrate evaporated to dryness to form the food. The sugars of such foods consist largely of maltose mixed with dextrin. The farinaceous foods, which depend for the conversion of their starch on the method of cooking or heating before serving, are usually mixtures of wheat or other cereal flour with malt or pancreatic extract. The milk foods are variously prepared, either by the simple desicca- tion of cow's milk (usually previously skimmed) or, when whole milk is used, by mingling the desiccated milk with sugars or baked cereal flour. Sometimes desiccated milk is used in mixture with a dried extract of malted cereals. In fact all sorts of mixtures are found on the market, involving, however, in nearly all cases, one modification or another of the above general processes of preparation. Composition. — Few complete analyses of these classes of foods have recently been made. Among the best are those of McGill,* from" whose work the following figures have been selected, illustrating typical examples of foods on the market : Farinaceous foods: Imperial granum Ridge's food Mother's food Robinson's barley Mixed foods: Horlick's malted milk Lactated food Mellin's food Nestle's milk food Reid & Camrick's baby food . . o m SI OS B3 9 12 6.04 8.12 9-99 9.41 0.72 0.48 0.13 0.41 1. 41 0.48 0.30 4-45 2.18 «io. U. S. Dept. of Agric, Bur. of Chem., Bui. 90, pp. 43-45- TEA, COFFEE, AND COCOA. 381 COMPOSITION OF ROASTED COFFEE. Alkalinity (cc. N/io Acid) of c V- 3 "0 < .a _3 1) •a c ca 'u 6 3 6 3 Variet 6 m 6 Ten Per Cent Extract. 0- u >, r y. 1 C Si ■2 ^,S CJ ctJ tM 2 3 ■d 3 1 l« c rt 0) J £ 2 A "0 OJ 1h ai a E c "o CJ < fl^ M U M M < A 20.80 16.83 0.52 2.28 13-41 1-25 1.0107 26.7 1-33770 2.64 0.40 Santos B 22.72 17 II .68 I. 00 11.02 I. 10 1.0108 26.9 1-33777 2.66 .39 ,C 21.70 17 80 .75 2.32 14.71 1.20 I. 0101 26.0 1-33743 2.46 ■30 Porto Rico 'A 22.48 15 70 .50 2.17 13.11 1.38 1.0107 26.6 1.33766 2.60 -37 B 21.76 16 36 .63 1.58 12.93 I. 21 1.0104 26-3 1-33754 2.50 -36 c 24.44 16 91 .54 2.62 12.50 1.32 1.0113 27.6 1.33804 2-77 -30 A 22.66 17 00 .68 2.82 14.08 I. II 1.0103 25-5 1-33724 2. 48 .40 Rio B 22.61 17 34 -78 1-47 13.10 I. 10 I. 0101 25-8 1-33735 2.46 -36 c 22.75 17 37 .61 2.62 11.91 I. 17 I.OIOI 26. c 1.33743 2.46 -30 A 24.00 18 01 1.78 2.30 11.22 I. 16 1.0106 26.4 1-33758 2.65 .40 Mocha B 20.27 17 96 -94 1.85 12.34 I. 10 I. 0101 26.3 1-33754 2.47 .36 c 24.18 19 55 1.42 2.90 13.20 1.18 I. 0111 27.3 1-33793 2.72 .40 A 23.85 15 95 -32 2.95 13-43 1-34 I. Olio 29.6 1-33777 2.63 •39 Java < B 22.19 15 45 .42 2.32 13-77 1.30 1.0107 26.5 1.33761 2.58 •38 ic 23.20 16 21 .66 3-34 14-75 1.27 1.0108 26.6 1.33766 2.62 •38 Highest. . 24.44 19 -55 1.78 3-34 14-75 1-34 1.0113 27.6 1.33804 2-77 .40 Lowest. . 20.27 16 •45 .32 1. 00 11.02 l.IO l.OIOl 26.0 1-33743 2.46 -30 Average . -- 22.63 17 •03 .75 2.30 13-03 1.20 I. 0105 26.6 1.33766 2.72 -37 * Omitted from average. 382 FOOD INSPECTION AND ANALYSIS. COMPOSITION OF COFFEE SUBSTITUTES AND OF ADULTERATED COFFEE. '0 1 < (0 1 u 1 6 c Alkalinity (cc. N/io Acid) of 6 ■ £ 6 s ^ - w c .2 Variety. 2c ^ 3 < < "o E ■ ni 2 Roasted wheat. Roasted chicory Coffee and chicory Coffee, chicory and pea hulls 5.60 5-55 5.08 3-64 5-71 4.37 3-96 4-97 2.82 2.27 3-14 4-05 0.00 .81 .06 .24 0.080 .026 *.284 0-34 -95 3-05 2.60 6.0 21.8 77.0 65.6 0.649 .277 .286 .472 1 .460 -314 -323 .740 2.40 .88 8-32 9-56 1-4745 1.84 1. 10 1.89 2.17 2 w "0 1 w 1 < M 3 1/1 M _C "0 3 •a I 5 J3 i 3 ■a U C 'S Ten Per Cent Extract. Variety. 2 C/2 Immersion Re- fractometer Reading at 20°. it5 .g 2 c 1 < 25.88 72.92 31-79 25.00 10.72 34-39 21.66 14.25 4.10 19-34 5.06 3.00 28.58 2.10 2.21 3-78 6.23 5-91 14-31 17.87 0.00 .00 -95 1. 00 Roasted chicory Coffee and chicory Coffee, chicory and pea hulls 1.0307 I. 0142 45-0 30-5 1-34463 I-339I5 7-44 3.62 0.26 .29 * Admixture of salt. METHODS OF ANALYSIS. The sample is prepared for analysis by grinding so as to pass a sieve with holes 0.5 mm, in diameter. Moisture, Ether Extract, Crude Fiber, Protein, and Ash (including total, water-soluble, water-insoluble, acid-insoluble and alkalinity) are determined as in the case of tea (pp. 368 and 369). Starch, Reducing Matters by AcM Conversion, Sucrose, and Reducing Sugars may be esti- mated by the methods described under cereal products. Ten Per Cent Extract. (See page 389.) Caffetannic Acid. — Krug's Method."^ — Two grams of the coffee are digested for thirty-six hours with 10 cc. of water, after which 25 cc. of * U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 908. TEA, COFFEE, AND COCOA. 3S5 90% alcohol are added, and the digestion continued for twenty-four hours more. The liquid is then filtered, and the residue washed with 90% alcohol on the filter. The filtrate, which contains tannin, caffeine, fat, etc., is heated to boiling and a boiling concentrated solution of acetate of lead is added, which precipitates out a caffetannate of lead, Pb3(Ci5Hi508)2, containing 49% of lead. When this has become flocculent, it is separated by filtra- tion, and washed on the filter with 90% alcohol, till the washings show Mk Ek Em II. Fig. 75. — CofEee. I. cross-section of berry, natural size. Pk outer pericarp; Mk endocarp; £/fe spermoderm; Sa hard endosperm; Sp soft endosperm. II. Longitudinal section of berry, natural size; Dis bordered dis"; Se remains of sepals; Em embryo. III. Embryo enlarged; co/ cotyledon; rad radicle. (Tschirch and Oesterle.) no lead with ammonium sulphide, and afterwards with ether, till free from fat. It is dried at 100° and weighed. The weight of caffetannic acid is obtained by multiplying the weight of the precipitate by 652, and dividing by 1263.63. Woodman and Taylor^s Modification.'*' — To 2 grams of finely ground coffee (passing 0.5 mm. sieve), add 10 cc. of water, and shake for an hour in a mechanical shaking device. Add 25 cc. of 90% alcohol and shake again for half an hour. Filter and wash with 90% alcohol. Bring the united filtrate and washings, about 50 cc, to boiling, and add 6 cc. of saturated lead acetate solution. Separate the precipitated lead caffe- tannate by means of a centrifuge, decanting the supernatant liquid through a tared filter. Repeat the centrifugal treatment twice with 90% alcohol, decanting each time through the filter. Transfer the precipitate to the filter, and wash free from lead. Wash with ether, dry at 100°, and weigh. The weight of the precipitate multiplied by 0.516 gives the weight of caffetannic acid. * A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 82. 3S4 FOOD n:SP3CTI0N AND ANALYSIS. Caffeine. — Gorier Method* — Moisten 11 grams of the finely powdered coffee with 3 cc. of water, allow to stand for half an hour, and extract for three hours in a Soxhlet or Johnson extractor with chloroform. Evaporate the extract, treat the residue of fat and caffeine with hot water, filter through a cotton plug, and wash with hot water. Make up the filtrate and wash- ings to 55 cc, pipette off 50 cc, and extract four times in a separatory funnel with chloroform. Evaporate this chloroform extract in a tared flask, dry the caffeine at 100° C, and weigh. Calculate the caffeine also from the nitrogen content. ADULTERATION OF COFFEE. According to the U. S. Standard roasted coffee is coffee which, by the action of heat, has become brown and developed its characteristic aroma, and contains not less than 10% of fat and not less than 3% of ash. Imitation Coffee. — Formerly, artificial coffee-beans containing no cofl'ee whatever, but cleverly molded to imitate the original, were occa- sionally to be found, mixed with genuine, whole coffee. f " Coffee pellets " are occasionally sold in bulk to dealers as an adulter- ant of whole coffee. These do not closely resemble the real berries in appearance, but are approximately of the same size, and are not apparent to the purchaser when the whole coffee is ground at the time of purchase. A sample of these " pellets " examined recently was found to consist of roasted wheat mash, colored with red ocher. Coloring Coffee Beans. — The practice of treating raw coffee beans in a manner somewhat analogous to the facing of tea leaves has been sometimes practiced, with a view to giving to cheaper or inferior grades the appearance of high-priced coffee. For this purpose various pigments have been employed, such as yellow ocher, chrome yellow, burnt umber, Venetian red, Scheele's green, iron oxide, tumeric, indigo, Prussian blue, etc., the coffee beans being first moistened with water containing a little gum, and shaken with the pigment. As a rule such pigments, especially when inorganic, are best sought for either in the ash, or in the sediment obtained by shaking the coffee beans in cold water, using the * Annalen, 358, 190S, p. 327. U. S. Dept. of Agric, Bur. of Chem., Bui. 132, p. 135. A. O. A. C. method. t A sample of such unitation whole coffee in the possession of the writer consists almost •entirely of roasted wheat molded into beans with difficulty to be distinguished in appear- ance from those of genuine cofTee, so closely do they resemble the original, even to the cleft in the sides. The chaff in the cleft is, however, lacking. TEA, COFFEE, AND COCOA. 385; ordinary qualitative chemical methods. Organic coloring matters can be best extracted with alcohol. Prussian blue and indigo are tested for as in the case of tea leaves (p. 375). Glazing. — This is a more recent form of treatment of the whole bean^ which consists in coating the beans by dipping in egg or sugar, or a mix- ture of the two, sometimes using various gums. Such glazing is alleged to improve the keeping qualities of the coffee, as well as to aid in clarify- ing the infusion, and if this is the sole purpose, the practice cannot be condemned as a form of adulteration. If, however, it is done to give inferior varieties of coffee a better appearance, in order to deceive the consumer, it clearly constitutes adulteration within the meaning of the law. Adulterants of Ground Coffee. — Of the adulterants used in ground coffee the following have been found in IVIassachusetts: Roasted peas, beans, wheat, rye, oats, chicory, brown bread, pilot bread, charcoal, red slate, bark, and dried pellets, the latter consisting of ground peas, pea huUs, and cereals, held together with molasses. Methods of Detecting Adulterants. — These methods are, as a rule,, physical rather than chemical. A rough test of the genuineness of ground coffee consists in shaking some of the sample in cold water. Pure coffee, under these conditions, usually floats on the surface, while the ordinary adulterants, such as cereals, chicory, mineral ingredients, etc., sink, ths grains of chicory coloring the water a brownish-red as they subside. Macfarlane recommends the use of a saturated solution of common salt, in which a portion of the suspected sample, divided in small grains, is shaken in a test-tube. If the liquid is colored pale amber, while all or nearly all the material floats, the coffee is pure. Any considerable sediment at the bottom of the tube, accompanied by a dark-yellow to brown color imparted to the liquid, indicates adulteration by roasted cereals, or chicory, or both. A careful examination of the coarsely crushed grains of a ground sample with the naked eye will often serve to detect, and in some cases identify, certain adulterants, such as chicory and ground peas or beans. A magnifying-glass will aid in such an examination, and the observer can often separate the various ingredients of a coffee mixture, first spread- ing a small portion of the sample on a sheet of white paper. The chicory grains are apparent from their dark and somewhat gummy appearance, and can usually be recognized by crushing them between the teeth. Their soft consistency and sweetish bitter taste are very distinctive. The dull 386 FOOD INSPECTION AND ANALYSIS. outer surface of the crushed coffee grains is in marked contrast to the polished appearance of the surface of the broken peas or beans, often to be found as aduherants, while fragments of broken cereal grains are readily distinguished from coffee with a low-power magnifier, though perhaps not easily identified by the eye alone. Determination of Added Starch. — Starch is determined in the finely powdered sample as directed on page 283. Microscopical Examination of Coffee. — By far the best means of detecting adulteration is furnished by the microscope. The individual grains of coarsely ground coffee and adulterants, separated by the cold water test or by picking over the mixture, are identified by microscopic examination either after sectioning with a razor or crushing to a powder. In addition, examination is made of a small portion of the sample pulver- ized in a mortar to a degree fine enough to allow the cover-glass to lie flat on the wetted powder, yet not so fine that it ceases to feel granular when rubbed between the fingers. The writer finds it sufficient to examine this powder in water without further treatment, although Schimper recommends maceration for twenty-four hours with ammonia, in order to render the tissues more transparent, using this reagent also as a mountant. In general the interior of the coffee tissue or endosperm consists of polygonal cells with highly characteristic, knotty, thickened walls, which are best seen in razor sections. Fig. 76, 2. These cells contain brilliant, colorless, spherical oil drops, and also proteins. The seed coat is also very characteristic, showing in the powder as occasional delicate silver-like patches, with peculiar, spindle-shaped, thick-sided cells, some of which are loosened from the tissue. Plates XIV and XV illustrate photomicrographs of pure and adulter- ated coffee. Fig. 174 shows genuine coffee, with its loose mesh of irreg- ularly polygonal cells, thick-walled, and inclosing oil drops with amor- phous material. It is not to be expected that every pulverized sample of genuine coffee, mounted as above, will show in every microscopic field the even, continuous structure that Fig. 174 illustrates, but careful examination will show in nearly every field fragments, and more or less disjointed por- tions of the polygonal cells, grouped in the form so characteristic of coffee. See Fig. 176. Chicory under the Microscope. — Fig. 77, after Moeller, shows struc- tural features of chicory. The most striking elements are the fine, thick- walled, long-celled, parenchyma of the bark rp and bp with its delicate TEA, COFFEE, AND COCOA. 3^7 Fig. 76.— 'Powdered Coffee under the Microscope. X125. (After Moeller.) i, seed coat (surface). 2, endosperm parenchyma. y /tTtjaX ',' .ill /Bo SJp--^:^ II / ,1 ■ I hp — I qu 'T Fig. 77.— Chicory Root in Tangential and Radial Sections. X160. g, reticulated ducts with perforations qu; hp, wood parenchyma; /, wood fibers; rp, bark parenchyma; sch, milk ducts; bp, bast parenchyma; m, medullary rays. (After Moeller.) 38S FOOD INSPECTION AND ANALYSIS. tracery, and the vessels or ducts g of the wood fibers. These ducts are tubular, resembling jointed cylinders, often with overlapping joints. Less distinct, but very characteristic of certain roots of the composite family, are the narrower branching milk ducts sch which do not exist in beets and turnips, which are sometimes substituted for chicory. Fig. 178, PL XV, is a photomicrograph of an adulterated sample of coffee, showing in this particular field chicory alone. It is a mass of con- fused cellular tissue, traversed by two broad bands of the vessels, with their striking, transverse, dotted markings. Fig. 177, PI. XV, shows a sample of coffee adulterated with roasted peas and pea hulls. No genuine coffee appears in this field. The chief masses in the center are characteristic aggregations of the round starch granules of the roasted pea. The rectangular billets, like bunches of matches, are from the outer or palisade layer of the pea. Fig. 164, PI. XI, and Fig. 154, PI. IX, show the close resemblance between the starches of the pea and bean, both of which are commonly used in coffee. The palisade structures of the hulls of these legumes also bear a close resemblance, but the cells of the next layer in the pea are hour-glass shaped, while in the bean they are not remarkable for their shape, but for the single crystal of calcium oxalate contained in each. The effect of roasting on starches used as adulterants of coffee is to twist and distort the granules, in some cases destroying largely the even structure of the raw starch. Starch granules of wheat, barley, and rye, for example, are almost perfect circular disks in the case of the raw starch, while in roasted products, such as pilot biscuit and stale bread, the granules are twisted and distorted, sometimes almost forming the letter " S." Use of Chicory in Coffee. — Chicory is a perennial herb (Cichorium intyhus) of the same family {Composites) as the dandelion. The roasted and pulverized chicory root is so much used in ground coffee to impart a peculiar flavor thereto, that by many it is considered as not strictly an adulterant. The taste imparted to coffee by a small admixture of pure chicory is to some desirable, but if its unrestricted use is sanctioned in this manner, the door would soon be opened to a more unlimited form of adulteration, wherein the chicory might predominate. It is, therefore, best to regard chicory as an adulterant, and to require the package con- taining a mixture of coffee and chicory, if sold legally, to have plainly printed thereon the percentage of chicory in the mixture. TEA, COFFEE, AND COCOA. 389 Chicory, when roasted, consists of gum, partly caramelized sugar, and insoluble vegetable tissue. Common adulterants of chicory are dried beets and other roots, also cereal matter, Villiers and Collin * give the following analyses of two samples of chicory : In Large Granules. In Powder. Soluble in water: Insoluble in water: ' Water (loss at 100° to 103°) Weight of total matter soluble in water. Reducing sugar Dextrin, gum, inulin Albuminoids Mineral matter , Coloring matter Albuminoids Weight of the total insoluble matter. . . . Mineral matter Fat [ Cellulose 16.28 57-96 26. 12 9-63 3-23 2.58 16.40 3-15 25.76 4.58 16.96 56.90 23-79 9-31 3-66 2-55 17-59 2.98 26.14 5.87 3-92 13-37 See also analysis of roasted chicory on page 382. Detection and Estimation of Chicory. — ^Various chemical tests for detection of chicory in coffee infusions have been suggested, depending on color reactions, t but these are, as a rule, unreliable. By far the best means for detecting chicory in coffee is furnished by the microscope. In mixtures containinoj coffee and chicory only, the approximate amount of the latter can be calculated from the specific gravity of a 10% decoc- tion, using conveniently the method of McGill.J A quantity of the pul- verized sample, corresponding to 10 grams of the dry substance, is weighed in a counterbalanced flask, and water added till the weight of the contents is no grams. Fit the flask with a reflux condenser, and after so regulat- ing the heat that boiling begins in ten to fiifteen minutes, continue the boiling for an hour. Remove the flame, and after fifteen minutes pass through a dry filter, cool, and determine the specific gravity at 15°. McGill found the average specific gravity of a 10% decoction as above carried out to be, in the case of pure coffee, 1.00986 and in the case of chicory 1.02821, the difference being 0.01835. The specific gravity of the 10% decoction of the suspected sample * Falsifications et Alterations des Substances Alimentaires, p. 234. t See Allen's Commercial Org. Analysis, 4 Ed., Vol. VI, pp. 671, 672. X Trans. Royal Soc. of Canada, 1887. 39° FOOD INSPECTION /tND /iN A LYSIS. at 15° being d, the per cent of chicory, c, can be calculated roughly by the formula (1.02821—^)100 c = ioo — 0.01835 This method is of course inapplicable when other substances than chicor}' are present. Date Stones, roasted and ground, have been used to some extent as a coffee adulterant. Fig. 78 shows the structural features of date stones Fig. 78. — ^Powdered Date Stones under the Microscope, end, endocarp; e, episperm; a, albumen in cross-section; a', albumen in longitudinal section. (After Villiers and Collin.) under the microscope. End represents a fragment of endocarp with its elongated, thick-walled cells, peculiarly arranged as shown, adjacent cells often lying with axes at right angles to each other. The more evenly formed episperm cells, e, are thin-walled and of a brown color. The albumen, a, is made up of very thick-walled, somewhat regularly arranged cells, indented from within with deep channels. Date stones are readily distinguished from coffee by these features. Hygienic Coffee. — Various processes have been devised for removing the caffeine from coffee. One of these, patented in Germany, has recently come into extensive use, as the flavor of the beverage is not greatly injured by the treatment. In following out this process the whole beans are first exhausted with water in a vacuum, and the infusion extracted with a suitable solvent for caffeine. The exhausted beans are then impregnated with the decaffeinated infusion and dried in a vacuum. This treatment. TEA, COFFEE, AND COCOA. 391 as shown by the investigations of Lendrich and Murdfield,* does not completely remove all the caffeine, the quantity remaining being from 0.14 to 0.26%, or about one-sixth of that in the untreated coffee. Further effects of the treatment are a decrease in the water extract and an increase in the fat. The following are the average of analyses, made by these authors, of caffeine-free and untreated coffee: P! <; "0 u a ^2; ■3 Analysis of the Dry Substance. < — _3 "o W Alkalinity of Ash (cc. N/i HCl per 100 grams of Coffee). 1 if ■ a> 'SvO oX £ g .S2 a. "Caffeine-free Coffee". .. Untreated coffee 14 9 % 2.13 1.46 % 4-23 4-71 % 3-22 3-77 47-72 56-43 % 21.30 26.17 % 17-13 15-73 % 0.22 1.19 % 11.83 11-75 Several brands of coffee, advertised to be free from tannin and in some cases also from caffeine, have been placed on the market in the United States. Some of these consist merely of ground coffee from which the chaff (which is represented to contain not only the tannin but also most of the caffeine) has been removed by mechancial means. The absurdity of the claims of the manufacturers is shown by the following analyses made in New Hampshire by C. D, Howard. f Caflfe- tannic Acid. Tanninless coffee No. i Tanninless coffee No. 2 Tanninless coffee No. 3 Java and Mocha Coffee chaff Water. Ash. Fat. Fiber. CafTeine. 2.70 4.10 13.18 18.46 1. 17 2.70 4-05 14.12 15-70 I-. 3 2.26 3.61 12-55 22.70 0.87 Z-T-i 4-13 14.10 15-50 1 .29 2.60 5-65 9-30 26.50 0.40 10.76 II .04 7.61 II. 17 5-98 The following analyses made at the Connecticut Station by E. J, ShanleyJ corroborate those of Howard: * Zeits. Unters. Nahr. Genuss., 15, 1908, p. 705. t A. O. A. C. Proc. 1906, U. S. Dept. of Agric, Bur. of Chem., Bui. 105, p. 41. X An. Rep. Conn. Exp. Sta., 1907, p. 141. 392 FOOD INSPECTION AND ANALYSIS. Caffeine ir. the Coffee. Caffetannic Acid in the Coffee. Caffetannic Acid in the Chaff. Per Cent of Chaff in the Coffee. Tanninless coffee A Tanninless coffee B Tanninless coffee C Java coffee Mocha coffee Rio coffee 1. 14 1. 11 1. 12 1 .26 I -13 9.89 9-45 9.96 9-51 9.96 9-47 S-46 7-55 6.79 1.80 2.38 1-77 Coffee Substitutes. — A large number of preparations sold as " coffee substitutes " or " cereal coffee " are now on the market in the United States, most of which are composed, as alleged on the labels, of cereals, ground peas, etc. Some contain roasted wheat, malt or some other cereal aLne, others are mixtures of cereals or cereal products and peas, and a few contain chicory. Some of these preparations have labels calling attention to the evil effects of coffee, and one of the latter class, extensively advertised, :jnd purporting to contain nothing but the entire wheat kernel roasted and ground, was found to contain peas, and about 30% of that " most harmful ingredient " coffee itself. Various substitutes are also made from dried fruits such as figs, prunes and bananas. In addition to the materials named the following have been used in Europe: beans, lupine seeds, cassia seeds, astragalus seeds, Parkia seeds, chick peas, soja beans, dried pears, carob bean pods, date stones, ivory nuts, acorns, grape seeds, fruit of the wax palm, cola nuts, false flaxseed, dandelion roots, beets, turnips and carrots.* As in the case of coffee the analyst must depend chiefly on the micro- scope in identifying the constituents of coffee substitutes. Coffee itself should properly be considered in the light of an adulterant. COCOA AND COCOA PRODUCTS. Nature of the Cocoa Bean. — The various chocolate and cocoa preparations are made from the bean of the tree Theobroma cacao, of the family of ByttneriacecB. This tree averages 13 feet in height, and its main trunk is from 5 to 8 inches in diameter. It is a native of the American tropics, being especially abundant and growing under best conditions in Mexico, Central America, Brazil, and the West Indies. The cocoa beans of commerce are derived chiefly from Ariba, Bahia, Caracas, Cayenne, Ceylon, Guatemala, Haiti, Java, Machala, Mara- * Winton's Microscopy of Foods, p. 435. TEA, COFFEE, AND COCOA. 393 caibo, St. Domingo, Surinam, and Trinidad. Besides these, the Sey- chelles and Martinique furnish a small amount. The plant seeds, or beans, grow in pods, varying in length from 23 to 30 cm., and are from 10 to 15 cm. in diameter. The beans, which are about the size of almonds, are closely packed together in the pod. Their color when fresh is white, but they turn brown on drying. The gathered pods are first cut open, and the seeds removed to undergo the process of " sweating " or fermenting, which is carried out either in boxes or in holes made in the ground. This process requires great care and attention, as upon it depends largely the flavor of the seed. The sweating operation usually takes two days, after which the seeds are dried in the sun till they assume their characteristic warm red color, and in this form are shipped into our markets. Manufacture of Chocolate and Cocoa. — For the production of chocolate and cocoa the beans are cleaned and carefully roasted, during which process the flavor is more carefully developed, and the thin, paper- like shell which surrounds the seed is loosened, and is very readily removed. The roasted seeds are crushed, and the shells, which are separated by winnowing, form a low-priced product, from which an infusion may be made, having a taste and flavor much resembling chocolate. The crushed fragments of the kernel or seed proper are called cocoa nibs, and for the preparation of chocolate they are finely ground into a paste and run into molds, either directly, or after being mixed with sugar and vanilla extract or spices, according to whether plain or sweet chocolate is the end product. For making cocoa, however, a portion of the oil or fat known as the cocoa butter is first removed, by subjecting the ground seed fragments to hydraulic pressure, usuaUy between heated plates, after which the pressed mass is reduced to a very fine powder, either directly, or by treat- ment with ammonia or alkalies, to render the product more soluble. It is held that the large amount of fat contained in the cocoa seeds (vary- ing from 40 to 54 per cent) is difficult of digestion to many, such as invahds and children, and hence the desirability of removing part of the fat. Composition of Cocoa Products. — The chief constituents of the raw cocoa bean, named in the order of their relative amount, are fat, protein, starch, water, crude fiber, ash, theobromine, gum, and tannin. During the roasting there is reason to believe a volatile substance is developed much in the nature of an essential oil, which gives to the 394 FOOD INSPECTION /iND yIN/ILYSIS. product its peculiar tiavor, and is somewhat analogous to the caffeol of cofifee. Tannin, the astringent principle of cocoa, exists as such in the raw bean, but rapidly becomes oxidized to form cocoa red, to which the color of cocoa is due. Weigmann gives the following results of analyses of cocoa nibs and shells : COMPOSITION OF COCOA NIBS. Commercial Varieties. u *o Nitrogenous Substances, including Theobromine. £ (D XI 1 <" SI < Caracas 7-77 7.87 7-53 7-77 8.17 8.08 8.27 14-13 14.06 13.69 14.56 14.06 13-50 15-37 1.48 I-3I 1.66 1-51 45-54 44.62 44-74 46.35 45-93 46.61 45-15 19.40 25-30 26.45 5-97 5-69 22.9 5-83 15-53 17-50 16.96 6.19 4-55 4-30 5-19 4-36 4-43 4-48 4.91 Trinidad Surinam 3 4 4 4 3 16 15 09 28 88 0.13 1.48 Port au Prince Machata Puerto Cabello 0.18 Ariba 0.14 COMPOSITION OF COCOA SHELLS. w w Commercial Varieties. 6 3 B S u '■z w £-° Sti S •d "rt C 4J c S gc« H fe gw (U < rt m ^M Caracas 12.49 14.64 13-93 14.89 13.18 14.62 0.58 0.74 0.78 0.75 2.38 3-45 2. 54 40.30 44.89 42.47 43-32 16.33 15-79 17.04 15-25 9.06 6.19 6.63 8.08 6.26 2.11 Trinidad 0.42 2.34 2.6a Surinam 16.25 16.18 0.85 0.27 Puerto Cabello 2.01 2-59 The following are the summarized results of the analyses of seventeen varieties of cocoa seeds and shells, made by Winton, Silverman, and Bailey.* * An. Rep. Conn. Agric. Exp. Sta., 1902, p. 770. TEA, COFFEE, AND COCOA. 395 Roasted Cocoa Nibs. Air-dry Material. Maxi- muiTi. Mini- mum. Mean. Water- and Fat-free Material. Maxi- mum. Mini- mum, Mean. Water Total ash Water-soluble ash Ash insoluble in acid Alkahnity of ash Theobromine Caffeine Other nitrogenous substances Crude fiber Crude starch (acid conversion) Pure starch (diastase conversion) Other nitrogen-free substances - Fat Total nitrogen Constants of fat (ether extract): Melting-point, degrees C Zeiss refractometer reading at 40° C Refractive index at 40° C Iodine number Per cent of nibs in whole bean " " "shells " " " 3.18 4-15 1.86 0.07 3-35 1.32 0-73 13.06 3.20 12.37 8-99 21.07 52-25 2.54 35 -o 48.00 :-4579 37-89 92.90 13.88 2.29 2.61 0-73 0.00 1.50 0.82 0.14 11.00 2.21 9-30 6-49 17.69 48.11 2.20 32-3 46.00 1-4565 33-74 86.12 8.83 2.72 3-32 1.16 0.02 2-51 1.04 0.40 12.12 2.64 II. 16 8.07 19-57 50.12 2.38 47-23 1-4573 34-97 88.46 11-54 3-96 o. 14 7.12 2.92 1-55 28.05 6.56 25.68 18.61 44.08 5-41 5-76 1.60 0.00 3-29 1.66 0.31 23-37 4.70 19.80 13.82 38.78 4-74 7.04 2.46 0.05 5-32 2.21 0.86 25-69 5.61 23.66 17.10 41.49 5-05 Roasted Cocoa Shells. Air-dry Material. Maxi- mum. Mini- mum. Mean. Water- and Fat-free Material. Maxi- mum. Mini- mum. Mean. Water Total ash Water-soluble ash Ash insoluble in acid Alkalinit)' of ash Theobromine Caffeine Other nitrogenous substances Crude fiber Crude starch (acid conversion). . Pure starch (diastase conversion) Other nitrogen-free substances. . Fat Total nitrogen 6.57 20.72 5-67 II. 18 5-92 0.90 0.28 18.06 19.21 13.89 5.16 51.86 5-23 3-17 3-71 7-14 2.02 0.05 5.02 0.20 0.04 10.69 12.93 9.87 3-36 43-71 1.66 1-74 4-87 10.48 3-67 2-51 5-52 0.49 0.16 14-54 16.63 11.62 4.14 46.40 2-77 2.34 21.97 6. II 11.86 6.47 0.97 0.31 19.40 20.72 15-42 5-59 55.84 3-41 5-63 2.16 0.05 5-32 0.22 0.04 11-34 13-71 10.47 3-65 47.04 1.87 3-97 2.70 5-97 0.52 o. 17 15-70 18.01 12.59 4-47 50.08 2-54 396 FOOD INSPECTION AND ANALYSIS. According to Bell* the ash of cocoa nibs has the following composi- tion: Per Cent. Sodium chloride 0.57 Soda 0-57 Potash 27.64 Magnesia 19.81 Lime - 4-53 Alumina o. 08 Ferric oxide 0.15 Carbonic acid 2.92 Sulphuric acid 4 . 53 Phosphoric acid 39 - 20 100.00 Theobromine (C7H8N4O2), the chief alkaloid of cocoa, when pure, forms a white, crystalline powder, having a bitter taste. It is slightly soluble in water and alcohol, very slightly soluble in ether, insoluble in petroleum ether, but readily soluble in chloroform. It sublimes at 290° to 295° C. It is a weak base, and much resembles caffeine. A small amount of caffeine has also been found in cocoa, but in most analyses is reckoned in with the theobromine. The Nitrogenous Substances of Cocoa, aside from the alkaloids, have been little studied. Stutzer has, however, separated them roughly as in the following analyses of four samples, of which A was manufactured without chemicals, B with potash, and C and D with ammonia: A. B. c. Total nitrogen Theobromine Ammonia Amido compounds Digestible albumin Indigestible nitrogenous substances Containing nitrogen Proportion of total nitrogen indigestible. 1.92 0.06 1-43 10.25 7.18 31.2 .1-73 0.03 1-25 7.68 9.19 1-47 44-5 3-95 1.98 0.46 0.31 10.50 7.68 1.23 31.2 3-57 1.80 0-33 1-31 7.81 8.00 1.28 35-8 Pentosans. — Several authors have called attention to the value of these substances as a means of detecting added shells in cocoa products. Liihrig and Seginf found in cocoa nibs from 2.51 to 4.58 per cent * Analysis and Adulteration of Foods. t Zeits. Unters. Nahr. Genuss., 12, 1906, p. 161. TE/I, COFFEE, /IND COCOA. 397 of pentosans calculated to the dry, fat-free substance, and in the shells from 7.59 to 11.23 P^'* cent calculated to the dry substance. Milk Chocolate, a product of comparatively recent introduction, consists of a mixture of chocolate, sugar, milk powder, and cocoa butter. It is especially prized by travelers and others who desire a concentrated, and at the same time palatable food. The following analyses by Dubois * show the composition of three of the leading brands on the market, and also illustrate the accuracy of Dubois' method of determining sucrose and lactose given on page 399. Polarization. Direct. After Inver- sion. Temp. °C. At 86°. Su- crose, Per Cent. Lac- tose, Per Cent. Reich- ert- Meissl Num- ber of Fat. Approx. Per Cent Butter Fat in Total Fat. Commercial milk chocolate: A B C Milk chocolate made in the laboratory: j^ / Found \ Calculated P / Found \ Calculated -f 2 1 . GO + 23.22 -f 23.88 + 19.00 2.00 2.22 2.20 1-50 24 23 + 1.36 + 1.50 + 1.36 + 1.40 + 19.70 + 0.99 40.90 45-73 46.78 35-99 35-82 39-84 39.80 8. 24 9.12 8.24 8.52 8.82 6.03 5-88 5-3 5-5 5-8 4-83 3-48 22.9 24.2 20.1 14.5 Various Compounds of chocolate or cocoa with other materials have been placed on the market. Zipperer f gives formulas or analyses of seventy-four such preparations, containing one or more of the following ingredients: oatmeal, barley meal, malt, malt extract, wheat flour, potato flour, rice, peas, peanuts, acorns, cola nuts, sago, arrowroot, Iceland moss, gum Arabic, salep, dried meat, meat extract, peptones, milk powder, plasmon (a preparation of casein), eggs, saccharin, vanilla, spices, and inorganic salts. Certain medicinal preparations also contain cocoa products. Cocoa Butter. — See page 529. * Jour. Am. Chem. See, 29, 1907, p. 556. f The Manufacture of Chocolate and Cacao Preparations, 2d ed., 1902. 39« FOOD INSPECTION AND ANALYSIS. METHODS OF ANALYSES, Preparation of the Sample. — Cocoa is usually in a fine powder, and needs merely to be put through a sieve, to break up lumps, and mixed. Chocolate should be grated or shaved so as to permit mixing. It can not be ground, as the heat of grinding reduces it to a paste. Moisture. — -Dry two grams of the material to constant weight at ioo° C. in a current of dry hydrogen. Somewhat lower results are obtained by drying in a dish in air. Ash. — Proceed as described under tea (page 369) in the determination of total, water-soluble and acid-soluble ash, and the alkalinity of the ash. Fig. 79. — Cocoa. 7 entire fruit, X4; 77 fruit in cross-section; 777 seed (cocoa bean) natural size; IV seed deprived of seed coat; V seed in longitudinal section, showing radicle (germ) ; VI seed in cross-section. (Winton.) Protein. — Determine total nitrogen by the Kjeldahl or Gunning method. From the percentage of total nitrogen subtract the nitrogen of the theobromin and caffeine, obtained by multiplying the percentages found by 0.3 ii and 0.289 respectively, and multiply the remainder by 6.25. Fat (Ether Extract). — Extract two grams of the material in a con- tinuous extractor until no more fat is removed. Grind the residue and repeat the extraction. Dry the combined extract at 100° C. and weigh. Constants of Fat. — See chapter on Edible Oils and Fats. Crude Fiber. — Proceed as in the analysis of cereal products (page 277), using the residue from the ether extraction. TEA, COFFEE AND COCOA. 399 Reducing Matters by Acid Conversion (Crude Starch).* — Weigh four grams of the material into a small Wedgewood mortar, add 25 cc. of ether, and grind with a pestle. After the coarser material has settled out, decant off the ether with the fine suspended matter on a 11 cm. paper. Repeat this treatment until no more coarse material remains. After the ether has evaporated, transfer the fat-free residue from the filter to the mortar by means of a jet of cold water, and rub to an even paste. Filter the liquid on the paper previously employed. Repeat the process of transferring from the filter to the mortar, grinding, and filtering, until all sugar is removed. In the case of sweetened cocoa products, at least 500 cc. of water should be used. Transfer the residue to a 500-cc. flask by means of 200 cc. of water,' and convert the starch into dextrose by Sachsse's method (page 283). Cool 'the acid solution, nearly neutralize with sodium hydroxide solu- tion, add 5 cc. of lead sub-acetate solution (page 586), make up to 250 cc. and filter through a dry filter. To 100 cc. of the filtrate, add i cc. of 60% sulphuric acid, shake thoroughly, allow to settle, and filter through a dry filter. Determine reducing matters by AUihn's method (page 608). Dubois,^ instead of treating with ether as above described, shakes four grams of the unsweetened product or eight grams of the sweetened with 100 cc. of gasoline, and whirls in a centrifuge to separate from the insoluble matter. After decanting off the gasoline layer, sweetened products are treated in like manner with two portions of 100 cc. of water to remove the bulk of the sugar, and finally washed on the paper. Starch. — Diastase Method. — Remove the fat and sugar from four grams of the material by treatment with ether and water, as described in the preceeding section, and determine starch in the residue by the diastase method (page 283). Pentosans. See page 285. Determination of Sucrose and Lactose. — Dubois Method. % — Place 26 grams of the material in an 8-ounce nursing bottle, add about 100 cc. petroleum ether and shake for five minutes. Whirl in a centrifuge until the solvent is clear, draw off the same by suction and repeat the treat- ment with petroleum ether. Keep the bottle containing the defatted residue in a warm place until the petroleum ether is practically expelled. * Winton, Silverman and Bailey, An. Rep. Conn. Exp. Sta., 1902, p. 275. t A. O. A. C. Proc. 190S, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 214. % A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem., Circ. 66, p. 15. 400 FOOD INSPECTION AND ANALYSIS. Add loo cc. water and shake until all the chocolate is loosened from the sides and bottom of the bottle and continue the shaking for three minutes longer. Add lo cc, of lead subacetate solution (p. 586), mix thoroughly and filter through a folded filter. Make the direct polariscopic reading (a) in a 200-mm. tube, then precipitate the excess of lead by dry potassium oxalate. Invert by one of the methods given on page 588, polarize, and multiply the invert reading by 2 to correct for dilution {h). Calculate the approximate percentages of sucrose {S) and lactose {L) by the follow- ing formulas: {a — h))>Ki\o (a X 1. 10)— 5 142.66—- ^ 2 From the sum of 5 and L calculate the approximate number of grams of total sugar G present in the 26 grams of sample taken and determine the factor X thus: X=iio + (GXo.62), in which 0.62 is the volume in cc. displaced by i gram of sugar in water solution. Applying this correction, SX ^ , ZX True per cent sucrose = — . True per cent lactose = ^ . ^ no no The following method of solution may be substituted for that given above : Transfer 26 grams to a flask, add 100 cc. water, cork, and heat in steam-bath for twenty minutes, releasing the pressure occasionally during the first five minutes. Twice during the twenty minutes shake thor- oughly so as to emulsify completely. Finally cool to room temperature, add 10 cc. lead subacetate solution, mix, and filter. Theobromine and Caffeine {Decker-Kunze Method) * — Boil 10 grams of the powdered material and 5 grams of calcined magnesia for 30 minutes with 300 cc. of water. Filter by the aid of suction on a Buchner funnel, using a round disk of filter paper. Transfer the material and paper to the same flask used for the first boiling, add 150 cc. of water, * Schweiz. Wchschr. Phar., 40, 1902, pp. 527, 541, 553; Abstract Chem. Centr., 74, 1903, p. 62; An. Rep. Conn. Exp. Sta., 1902, p. 274. TEA, COFFEE, AND COCOA. 4<5J and boil 15 minutes. Filter as before, and repeat the operation of boiling with 150 CO. of water and filtering. Wash once or twice with hot water. Evaporate the united filtrates (with quartz sand if sugar be present). to complete dryness in a thin glass dish of about 300 cc. capacity,* Grind to a coarse powder in a mortar provided with a suitable cover to prevent loss by flying. Transfer to the inner tube of a continuous fat extractor, and dry thoroughly in a water oven. Extract with chloro- form for 8 hours, or until the theobromine and caffeine are completely removed, into a weighed flask. It is important that the material be thoroughly dry, that an extractor be used that permits of a hot extraction, and that a considerable volume of chloroform passes through the material. Distil off the chloroform, and dry at 100° C. to constant weight. If the material be pure chocolate or cocoa, the extract thus obtained is practically pure theobromine and caffeine, but if the material is cocoa shells or a cocoa product mixed with a large amount of shells, the extract may be brown in color, due to the presence of considerable amounts of impurities. In either case, separate the caffeine by treating the extract in the flask at the room temperature for some hours with 50 cc. of pure benzol. Filter through a small paper into a tared dish, evaporate to dryness, and dry to constant weight at 100° C, thus obtaining the amount of caffeine. Determine theobromine by Kunze'sf method, as follows: Add to the residue and paper 150 cc. of water, enough ammonia water to make the liquid slightly alkaline, and an excess of decinormal silver nitrate solution. Boil to half the original volume, add 75 cc. of water, and repeat the boiling. The solution should be perfectly neutral. If it contains the slightest amount of free ammonia, add water and boil until it is completely removed. Filter from the insoluble silver theobromine compound, and wash with hot water. In the filtrate determine the excess of silver nitrate by Volhard'sJ method as follows: Add 5 cc. of cold saturated solution of ferric ammonium sulphate (ferric-ammonium alum), and enough boiled nitric acid to bleach the liquid. Titrate with decinormal ammonium sulphocyanide solution until *a permanent red color appears. * A " Hoffmeister Schalchen " may be used, or dishes may be made from broken flasks by making a scratch with a diamond and leading a crack from this scratch about the flask by means of a glowing springcoal. t Ztschr f. anal. Chem., ;}^, 1894, p. i. ^. I Ibid., 13, 1874, p. 171. 402 FOOD INSPECTION AND ANALYSIS. One cc. of decinormal AgNOs solution is equivalent to 0.01802 gram of theobromine. If the mixed alkaloids were colorless, the theobromine obtained by subtracting the weight of caffeine from the weight of the mixed alkaloids will usually agree closely with that obtained by silver titration. ADULTERATION OF COCOA PRODUCTS AND STANDARDS OF PURITY. The following are the U. S. standards:* Standard chocolate should contain not more than 3% of ash insoluble in water, 3.5% of crude fiber, and 9% of starch, nor less than 45% of cocoa fat. Standard sweet chocolate and standard chocolate coating are plain chocolate mixed with sugar (sucrose), with or without the addition of cocoa butter, spices, or other flavoring material, containing in the sugar- and fat-free residue no liigher percentage of either ash, fiber, or starcti than is found in the sugar- and fat-free residue of plain chocolate. Standard cocoa should contain percentages of ash, crude fiber, and starch corresponding to those of plain chocolate, after correcting for fat removed. Standard sweet cocoa is cocoa mixed with sugar (sucrose) containing not more than 60% of sugar, and in the sugar- and fat-free residue no higher percentage of either ash, crude fiber, or starch than is found ir\ the sugar- and fat-free residue of plain chocolate. The removal of fat, or the addition of sugar beyond the above pre- scribed limits, or the addition of foreign fats, foreign starches, or other foreign substances, constitutes adulteration, unless plainly stated on the label. The most common adulterants of cocoa are sugar and various starches, especially those of wheat, corn, and arrowroot. Starch is sometimes added for the alleged purpose of diluting the cocoa fat, instead of remov- ing the latter by pressure, thus, it is claimed, rendering the cocoa more digestible and more nutritious. Unless its presence is announced on the label of Lhe package, starch should be considered as an adulterant. Cocoa shells are also commonly employed as a substitute for, or an adulterant of, cocoa. Other foreign substances found in cocoa arp sand and ground wood fiber of various kinds. Iron oxide is occasionally used as a coloring matter, especially in cheap varieties. * U. S. Dept. of Agric, Off. of Sec, Circ. 19. TE/t, COFFBE, AND COCOA.. 403 Such adulterants as the starches and cocoa shells are best detected by the microscope. The presence of any considerable admixture of sugar is made apparent by the taste. Mineral adulterants are sought for in the ash. Addition of Alkali. — The amount of water-soluble matter in cocoa is very small (about 20 to 25 per cent), and in preparing the beverage, the desideratum aimed at is to produce as perfect an emulsion as possible. The legitimate means of accomplishing this is by pulverizing the cocoa very fine, so that particles remain in even suspension and form a smooth paste. Another means sometimes resorted to for producing a so-called *' soluble cocoa" is to add alkah in its manufacture, the effect being to act upon a part of the fat, and produce a more perfect emulsion with less separation of oil particles. Such treatment with alkah is regarded with disfavor,, even if not considered as a form of adulteration. Cocoa thus treated is generally darker in color than the pure article. The use of alkah is usually rendered apparent by the abnormally high ash, and by the increased alkahnity of the ash, the latter constant being expressed in terms of the number of cubic centimeters of decinormal acid necessary to neutrahze the ash of i gram of the sample. In pure, untreated cocoa, the ash rarely exceeds 5.5%, and the alkahnity of the ash is generally not more than 3.75. In cocoa treated with alkah, the ash sometimes reaches 8.5%, with the alkahnity running as high as 6 or even 8. Microscopical Structure of Cocoa. — Fig. 80 shows elements of the powdered cocoa bean, both of the shell and of the kernel. The powder of the latter should constitute pure cocoa, with occasional fragments only of the shell. The irregular lobes constituting the kernel are each inclosed in a membrane made up of angular cells, filled with granular matter. (4), (5), and (6) show elements of the powdered cotyledons, or seed kernels. The polygonal tissue of the cotyledon is shown in cross- section at (4). In the powder one finds also dark granular matter, bits of debris, and fragments, with masses of yellow, reddish-brown, and sometimes violet coloring matter, together with numerous starch granules and aleurone grains. The starch granules are nearly circular, with rather indistinct central nuclei, and range in size from 0.0024 to 0.0127 rnm., averaging about 0.007 ^ni- They are more often found in single detached grains, but sometimes in groups of two or three. Occasional spiral ducts, sp, are seen, but these are not abundant in the pure cocoa. 404 FOOD INSPECTION AND ANALYSIS. The masses of color pigment are shown up with striking clearness, according to Schimper, by applying a drop of sulphuric acid to the edge of the cover-glass and allowing it to penetrate the tissue. The bits of coloring matter are for a short time colored a brilliant- red, which, how- ever, soon fades. Ferric chloride colors them indigo blue. Schimper recommends mounting the powder in a drop of chloral hydrate, which soon renders most of the tissues transparent. It is some- times necessary to allow the chloral to act on the powder in a closed •J-Tl ep p_-. LW qu—j^ Fig. 8o. — Cocoa under the Microscope. A. Powdered Cocoa under the Microscope. X125. (After Moeller.) i, cross-section through shell parenchyma; 2, thick-walled cells; 3, epidermis of shell (surface section); 4, cross-section of cotyledon tissue; 5, 6, cotyledon parenchyma; 7, starch. B. Cocoa Shell in Surface Section. X160. e^, epicarp; ^, parenchyma of the fruit; qu, layer of transverse cells. (After Moeller.) vessel for twenty-four hours, before all the elements, of pure cocoa are rendered transparent. If after that time opaque masses are still found, these are due to foreign material. Ammonia may be used instead of chloral with even better results, but this reagent requires longer treatment, soaking for several days or a week being sometimes necessary. Fig. 185, PL XVII, shows the microscopical appearance of genuine powdered cocoa with its variously sized starch grains and the debris of the ground cotyledons. Fig. i86 shows cocoa adulterated with arrowroot. TEA, COFFEE, AND COCOA. 405 Cocoa Shells. — A cross-section of the shell parenchyma and the stone- cell layer, also some of the numerous spiral ducts, all characteristic of the ground shell, are shown at i. Fig. 80. The thick- walled stone-cells are shown in surface view at 2, and the spongy, outer seed-skin, composed of two layers, with elongated cells running crosswise to each other in striated fashion, and with the underlying hairs or so-called "Mitscherhch bodies," is shown at 3, The presence of an abnormally large number of yellow and brow^n frag- ments in the water-mounted cocoa specimen, even under smaU magnifi- cation, arouses suspicion of the presence of shells, the most distinctive elements of which are the spongy tissue, the stone cells, and the abundant spiral ducts, the latter being scarce in pure cocoa powder. Cocoa shells are indicated on chemical analysis by the abnormally high ash,- crude fiber and pentosans. Added Starch. — This can only be approximately determined by a careful examination with the microscope. Long experience will enable the analyst to familiarize himself with the appearance and abundance of starch grains of various kinds in a series of fields, so that he can roughly estimate the amount of each starch present in the mixture, by careful comparison with mixtures of known percentage composition. If the amount of starchy adulterant is considerable, evidence may be secured by determinations of starch by the diastase method and reducing matters by acid conversion. Added Sugar. — Any appreciable amount of added cane sugar is shown by the sweet taste. The amount of cane sugar may be determined by means of the polariscope, as described on page 399. An abnormally low ash is indicative of the addition of starch or sugar or both. Foreign Fat. — Certain manufacturers have found it profitable to remove a portion of the cocoa butter from chocolate and substitute for it a cheaper fat, such as cocoanut oil, tallow or even paraffine. Such adulteration is detected by determination of the physical and chemical constants of the fat obtained by extraction with ether. Dyes and Pigments, such as Bismark brown and Venetian red, have been employed to hide the presence of diluents. They are detected by dyeing tests, and by examination of the ash. 4o6 FOOD INSPECTION AND ANALYSIS. REFERENCES ON TEA, COFFEE, AND COCOA. Baker, W., & Co. The Chocolate Plant and Its Products. Boston, 1891. Berteand, G. Coffees without Caffein. Compt. rend., 141, 1905, p. 209. Beythien, a., Bohrisch, P., and Deiter, J. Beitrage zur Chemischen Untersuchung des Thees. Zeits. Unters. Nahr. Genuss., 3, 1900, p. 145. Clayton, E. G. Roasted Beetroot. • Analyst, 29, 1904, p. 279. Crole, D. Tea: a Textbook of Tea Planting and Manufacture. London, 1897. V. CzADEK, O. Beitrag zur Beurteilung von Feigenkaffee. Z. land. Versuchs. Oester. 5, 1902, p. 761. Davies, S. H., and McLellan, B. G. Amount of Cocoa Butter contained in the Cocoa Bean. Jour. Soc. Chem. Ind., 23, 1904, p. 480. Decker, J. Zur Kenntnis der Kakaoschalen. Pharm. Cent., 46, 1905, p. 863. DucHACEK, F. Beitrage zur Kenntnis der chemischen Zusammensetzung des Kaffees und der Kaffee-Ersatzstoffe. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 139. Dubois, W. L. Determination of Lactose and Butter Fat in Milk Chocolate. Jour. Am. Chem. Soc, 29, 1907, p. 556. Dyer, B. Chicory, and Variations in its Composition. Analyst, 23, 1898, p. 226. EwELL, E. E. The Carbohydrates of the Coffee Bean. Am. Chem. Jour., 14, 1892, P- 373- FiLSiNGER. Zur Untersuchung und Begutactung der Kakaofabrikate. Z. offent. Chem., 9, 1903, p. 6. Genin, V. Cafe, Chicoree, The, Mate, Coca et Cacao. Analyse des Matieres Ali- mentaires. Girard et Dupre. Paris, 1894. Hanausek, T. F. Ueber die Harzglasur des Kaffees. Zeits. Unters. Nahr. Genuss., 2, 1899, p. 275. Hanus, J. Zur Fettbestimmung in Kakao nach dem Gottlieb-Rose'schen Verfahren. Zeits. Unters. Nahr. Genuss., 11, 1906, p. 738. Hehner, O., and Skertchly, W. P. Estimation of Pentosans and its Application to the Analysis of Foods. Analyst, 24, 1899, P- i?^- Jaeger, R., and Unger, E. Beitrag zur Kenntnis der Kakaoschalen. Zeits. Unters. Nahr. Genuss., 10, 1905, p. 761; Ber. d. Chem. Ges., 35, 1902, p. 4440; 36, 1903, p. 1222. ELatz, J. Der Koffeingehalt des als Getrank benutzten Kaffeeaufgusses. Arch. Pharm., 242, 1904, p. 42. Kenrick, a. Tea. Canada Inland Rev. Dept. Bui. 24. KiRSCHNER, A. Die Bestimmung des Fettes in Kakao. Zeits. Unters. Nahr. Genuss., II, 1906, p. 450. KoENiG, J. Chemie der menschlichen Nahrungs- und Genussmittel. Vierte Aufl. Berlin, 1903. KuNZE, W. E. Quantitative Separation and Estimation of the Alkaloids of Pure Coffee. Analyst, 19, p. 194. Laxa, O. Ueber Milch-Schokoladen. Zeits. Unters. Nahr. Genuss., 7, 1904, p. 491. Lehmann, K. Die Fabrikation des Surrogatkaffees und des Tafalsenfes. Vienna, 1893. Lendrich, K., und Murdfield, R. "Coffein-freier Kaffee." Zeitr. Unters. Nahr. Genuss., 15, 1908, p. 705. TEA, COFFEE, AND COCOA. 407 Lodge, J. L. Coffee: History, Growth, and Cultivation; its Preparation and Effect on the System. London, 1894. LUDWIG, W. Die Bestimmung der Rohfaser in Kakao. Zeits. Unters. Nahr. Genuss., 12, 1906, p. 153. Llthrig, H. Zur Kenntnis der Kakaoschalen. Zeits. Unters. Nahr. Genuss., 9, 1905, p. 263. LiJHRiG, H., and Segin, A. Pentosangehalt der Kakaobohnen und seine Verwertung zum Schalennachweis im Kakaopulver. Zeits. Unters. Nahr. Genuss., 12, 1906, p. 161. Macfarlane, T. Coffee. Canada Inl. Rev. Dept. Buls. 3, 29, 31. McGiLL, A. Cocoa and Chocolate. Canada Inl. Rev. Dept. Bui. 72. Matthes, H., and Muller, F. Beitriige zur Kenntnis des Kakaos. Zeits. Unters. Nahr. Genuss., 12, 1906, p. 88. Die Bestimmung der Rohfaser in Kakaowaren. Ibid., p. 159. Michaelis, a. Der Kaffee als Genuss- und Heilmittel nach seinen botanischen, chemjschen, dietetischen und medicinischen Eigenschaften. Orth, E. Beitrag zur Untersuchung und Beurteilung kandierter Kaffees. Zeits. Unters. Nahr. Genuss., 9, 1905, p. 137. Pearmain, T. H., and Moor, C. G. On the Adulteration of Coffee. Analyst, 20, 1895, p. 176. Smethane, a. Composition of Some Samples of Pure Coffee. Analyst, 7, 1882, p. 73. Spencer, G. L. Tea, Coffee, and Cocoa Preparations. Div. of Chem., Bui. 13, Part VII, 1892. Steinmann, a. Ueber die Bestimmung des Zuckers in Schokolade. Schw. Woch. Chem. Pharm., 40, 1902, p. ,581; 41, 1903, p. 65. Trillich, H. Die Kaffeesurrogate, ihre Zusammensetzung und Untersuchung. Munich, 1889. Wanklyn, J. A. Tea, Coffee, and Cocoa. London, 1883. Welmans, p. Zur Priifung von Schokolade auf den Gehalt an Zucker. Z. offent. Chem., 9, 1903, pp. 93 and 115. Kakao und Schokolade. Ibid., p. 206. WiGNER, G. W. Nitrogenous Constituents of Cocoa. Analyst, 4, 1879, p, 8. WiNTON, A. L., SiLVERiiAN, M., and Bailey, E. M. Cocoa. An. Rept. Conn. Exp. Sta., 1902, p. 248. Chocolate. Ibid., 1903, p. 123. Wolff, J. Ueber die Zusammensetzung und die Untersuchung der Cichorienwurzel. Zeits. Unters. Nahr. Genuss., 3, 1900, p. 593. Yapple, F. Analyses of Cocoa. Amer. Jour. Pharm., 67, 1895, p. 318. ZiPPERER. The Manufacture of Chocolate and Other Cacao Preparations. 2d ed. Berlin, 1902. Conn. Exp. Sta. Annual Reports, 1896 et seq. Maine Exp. Sta. Bui. 65. Analysis of Coffee Substitutes. Massachusetts State Board of Health Reports, 1882 et seq. N. H. Sanitary Bui., Jan., 1906, p. 168. North Carolina Exp. Sta. Bui. 154. Adulteration of Coffee and Tea. Penn. Dept. of Agric. An. Rept., 1897, p. 178. Substitutes for Coffee. " " " 1898, pp. 75 and 548. Coffee and its Adulterations. " " " 1898, pp. 90 and 652. Chocolate and Cocoa. CHAPTER XII. SPICES. These aromatic vegetable substances are classed as condiments, and depend for their use on the pungency which they possess in giving flavor or reHsh to food. As such seasoning or zest-giving substances, they are of considerable importance dietetically, but from the fact that they are used in comparatively insignificant amount, the determination of their chemical composition or actual value as nutrients per se is of little im- portance to the food economist. Spices are, however, of chief interest to the public analyst, because of all food materials they constitute from their nature a class more sus- ceptible than others to fraudulent adulteration of the most skilled variety. In many cases not only the megascopic appearance and taste of the skillfully adulterated article are made to counterfeit the genuine spice, but even the microscopical appearance is intended to deceive, since it is the microscope that is most useful in the detection of adulteration, and in many cases in the determination of the approximate amount of the adulterants. Indeed it is very rare that the microscope will fail to detect the presence of any foreign substance in spice, and hence its use is indispensable in the study of this class of foods by the analyst. Chemical methods, as a rule, while of secondary importance, are, however, very helpful, both as confirmatory of the microscopical research, and in some cases show- ing instances of adulteration not readily apparent with the microscope, such, for example, as in the case of exhausted spices, or those deprived of a whole or a part of their volatile oil. Sophistication of this kind is best shown by the ether extract. General Methods of Proximate Analysis. — The following methods common to all the spices are for the most part those adopted provisionally by the A. O. A. C* Methods pecuhar to special spices will be treated * U. S. Dept. of Agric, Bur. of Chem., Bui. 65 and Bui. 107 (rev.)- 408 SPICES. 409 under the discussion of the spice in question. For these determinations the spices should be powdered fine enough to pass through a 60-mesh sieve. Determination of Moisture. — Richardsofi's Method* — Two grams of the sample are weighed in a tared platinum dish and dried in an air-oven at 110° to a constant weight, which generally requires about twelve hours. The loss in weight includes the moisture and the volatile oil. The latter is determined from the ether extract, as described on page 410, and deducted from the total loss to obtain the moisture. McGill t determines the moisture by exposure of a weighed portion of the sample in vacuo over perfectly colorless sulphuric acid. The spice gives up its moisture before the volatile oil comes off, and any appreciable amount of the volatile oil, when absorbed by the acid, causes the latter to be discolored, so that by carefully observing the beginning of the dis- coloration, and removing the sample, the loss due to moisture may be obtained by weighing at the proper stage. The abstraction of the mois- ture in this manner requires about twenty-four hours. Determination of Ash. — Two grams of the spice are burned in a platinum dish heated to faint redness on a piece of asbestos paper by means of a Bunsen burner. The burning is best finished in a muffle furnace. If the ash contains 'an appreciable amount of carbon, it is exhausted on a fiilter with hot water, and the filter with the residue is burnt in the dish previously used. After adding the aqueous extract and a few drops of ammonium carbonate solution, the whole is evaporated to dryness and ignited at a faint red heat. T/ic Waler-soluble Ash | is found by boiling the total ash as above obtained with 50 cc. of water, and filtering on a tared Gooch crucible, the insoluble residue being washed with hot water, dried, ignited, and weighed. The insoluble ash, subtracted from the total, leaves the water- soluble ash. Sand. — This is assumed to be the percentage of ash insoluble in hydrochloric acid. The ash from 2 grams of the substance, obtained as above described, is boiled with 25 cc. of 10% hydrochloric acid (specif:c gravity 1.050) for five minutes, the insoluble residue is collected on a tared Gooch crucible, thoroughly washed with hot water, and finally dried and weighed. * U. S. Dept. of Agric, Div. of Chem., Bui. 13, pt. 2, p. 165. t Canada Dept. of Inland Rev. Bui. 73, p. 9. X U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 55; Bui. 107 (rev.), p. 162. 4IO FOOD INSPECTION AND ANALYSIS. Lime is determined from the ash as directed on page 303, having first separated the iron and phosphates. The sulphuric acid due to calcium sulphate (added as an adulterant) is determined by precipitation with barium chloride of a ver/ weak hydro- chloric acid solution of the ash, the separated barium sulphate being washed, dried, ignited, and weighed. Ether Extract. — Total, Volatile, and Non-volatile.'^— Tv^o grams of the air-dry, powdered substance are placed in some form of continuous extraction apparatus, such as Soxhlet's or Johnson's (pp. 64 and 65), and are subjected to extraction for sixteen hours with anhydrous, alcohol- free ether.f The ether solution is then transferred to a tared evaporating- dish, and allowed to evaporate spontaneously at the temperature of the room. After the disappearance of the ether, the evaporating-dish is placed in a desiccator over concentrated sulphuric acid and left over night, or for at least twelve hours, after which it is weighed, the residue in the dish being regarded as the total ether extract. The dish and its contents are then subjected to a heat of about 100° C. for several hours, taking a long time to bring the temperature up to that point so as to avoid oxidation of the oil. Finally heat at 110° C. till the weight is constant. The final residue is the non- volatile, and the loss in weight the volatile ether extract. Alcohol Extract. — Method 0} Winton, Ogden, and Mitchell. % — Two grams of the powdered sample are placed in a loo-cc. graduated flask, which is filled to the mark with 95% alcohol. The flask is stoppered and shaken at half-hour intervals during eight hours, after which it is allowed to stand for sixteen additional hours without shaking, and the contents poured upon a dry filter. Of the filtrate, 50 cc. are evaporated to dry- ness in a tared platinum dish on the water-bath, and heated at 110° C. in an air-oven to constant weight. This method, while only approxi- mate, is so much simpler than the tedious operation of continuous extrac- tion, considering the long time required, that it is regarded as preferable for ordinary work, and, unless great care is taken, is nearly as accurate. Determination of Nitrogen. — This, in spices other than pepper, is best done by means of the Gunning or Kjeldahl method (p. 69). * Richardson, U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 165. t Petroleum ether may be used, yielding results which differ but slightly from those obtained with ethyl ether. As the latter has been used in the analyses of a large number of samples of spices, if these analyses are to be taken for standards of comparison it is evi- dent that the same solvent should be used. I U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 56; Bui. 107 (rev.), p. 163. SPICES. 411 Determination of Starch. — In spices like white pepper, ginger, and nutmeg that normally contain a high content of starch and very little other copper-reducing matter, the direct acid conversion process of starch determination is satisfactory. In spices normally free from starch, such as cloves, mustard, and cayenne, where a starch determination indicates the amount of a foreign starch present as an adulterant, it is safer to use the diastase process. Four grams of the powdered sample are extracted on a filter-paper (fine enough to retain all starch particles) first with five successive por- tions of 10 cc. of ether, then with 150 cc. of 10% alcohol. Owing to difficulty of filtering in the case of cassia and cinnamon, Winton recom- mends that all washing in the determination of starch in these substances be omitted. The residue is washed from the filter-paper by means of a stream of water into a 500-cc. flask, if the direct acid conversion method is used, using 200 cc. of water; 20 cc. of hydrochloric acid (specific gravity 1.125) are added, and the method from this point on followed, as detailed on page 283. If the starch is to be determined by the diastase method, wash the residue from the filter-paper into a beaker with 100 cc. of water, and proceed as on page 283. Determine the dextrose in cither case by the Defren or Allihn method* or volumetrically, and convert dextrose to starch by the factor 0.9. Determination of Crude Fiber. — Two grams of the substance are extracted with ordinar}' ether (or the residue left from the determination of the ether extract may be taken) and subjected to the regular method for determining crude fiber, by boiling successively with acid and alkali (page 277). McGill recommends the use of the centrifuge in separating the crude fiber, after boiling with the alkaline solution. Determination of Volatile Oil. — Method of Girard and Dupre* — The spice is mixed with water and subjected to distillation, receiving the distillate in a graduated cylinder. The volume occupied by the essential oil (which is immiscible with water) can be thus rea-d off and its content roughly determined. If the volatile oil is slightly soluble in water, separate out the water layer, having first read the volume of the oil layer, and extract the aqueous solution with petroleum ether. Evaporate the petroleum ether extract to dryness at room temperature * Analyse des Matieres Alimentaires, 2nd ed., p. 787. 412 FOOD INSPECTION AND ANALYSIS. in a tared dish, and add the volume due to the weight of the residue to the volume read off in the graduate. Microscopical Examination of Powdered Spices. — As a rule few micrcscopical reagents are necessary in the routine examination of powdered spices for adulteration, unless a more careful study of the structure than is necessary to prove the presence of adulterants is desir- able. The simple water-mounted specimen is usually sufficient to show the purity or otherwise of the sample. If in doubt as to the presence of starch in small quantities, iodine in potassium iodide should be applied to the specimen, well rubbed out under the cover-glass. The tissues may be cleared by adding to the water mount a small drop of 5% sodium hydroxide, or by soaking a portion of the spic? for a day in chloral hydrate solution. A valuable means of clearing dense tissues is to boil about 2 grams of the material successively with dilute acid and alkali as in the crude fiber process (p. 277), decanting (not filtering) the solution after each boiling. The presence of occasional traces of a foreign substance, when viewed under the microscope, is hardly sufficient to condemn the sample as adulterated, since such traces are apt to be accidental. Composition of Miscellaneous Spice Adulterants. — The chemical analyses of various spice adulterants commonly met with are given on page 413. CLOVES. Nature and Composition. — Cloves are the dried, undeveloped flowers of the clove tree {Caryophyllus aromaticus or Eugenia caryophyllata), which belongs to the myrtle family (Myrtacecp). The tree is an evergreen, from twenty to forty feet in height, cultivated extensively in Brazil, Cey- lon, India, Mauritius, the West Indies, and Zanzibar. Its leaves are from 7.5 to 13 mm. long, and its flowers, of a purphsh color, grow in clusters. The green buds in the process of growth change to a reddish color, at which stage they are removed from the tree, spread out in the sun, and allowed to dry, the color changing to a deep brown. Each whole clove consists of a hard, cylindrical calyx tube, having at the top four branching sepals, surrounding a ball-shaped casing, which consists of the tightly overlapping petals, and within which are the stamens and pistil of the flower. In taste the clove possesses a strong and peculiar pungency. One of its most valuable ingredients is the volatile clove oil. This is composed largely of eugenol (CioHj.Oj), which forms 70 to SPICES. 413 COMPOSITION OF SPICE ADULTERANTS. English-walnut shells * Brazil-nut shells* . .. . Almond shells * Cocoanut shells * Date stones * Spruce sawdust * Oak sawdust * Linseed meal * Cocoa shells * Red sandalwood * Ground olive stones f Buckwheat hulls 7-69 08 80 36 24 77 73 71 44 42 50 67, Ash. 1.40 1-59 2.86 0.54 1.24 0.23 1.22 5.72 8.40 0.70 0.88 1.84 1^ 0.77 1 .06 2-39 0.50 0.76 0. 16 0.32 1-74 4.66 0.28 0.24 1 . :^J 0.00 0.17 0.05 0.00 0.04 0.00 0.02 0-55 0.83 0.07 0.44 Ether Extract. 0. 12 0.07 0.16 coo 0.36 0.07 0.07 0.04 1 .00 I. 21 0.06 0.07 0-55 0-57 0.64 0.25 8.38 0.77 C.84 6.58 2-99 11.47 0.24 1.84 1. 01 5 -16 1. 12 16.72 1.50 6.25 9.46 4-77 19-37 2.17 C V-'rj C ^^0 >. a, . X c Oxypen Ab- sorbed by Aqueous Extract. (D cr 1.69 0-53 2.08 4.19 0-33 1.30 1-75 0.40 1.56 1-13 0.47 1.82 5-31 0.61 2-34 o.s6 0.30 1. 17 1.63 3-13 12.22 31.81 1. 00 3-90 16.19 1.26 4-94 3.06 1.06 0-59 ..... 2.29 3.06 3 G English-walnut shells * . Brazil-nut shells * Almond shells * Cocoanut shells * Date stones * Spruce sawdust * Oak sawdust * Linseed meal * Cocoa shells * Red sandalwood * Ground olive stones t ■ Buckwheat hulls 19.30 12.96 22.72 20.88 20.88 15.48 17.10 21.15 8.68 6-79 20.^1 0-73 0.84 0-73 2.19 1-13 1.68 14.06 3-15 1. 12 1-73 1 .46 56-58 50. 98 49.89 56.19 5-72 64.03 47-79 8.30 14.12 52-30 57-46 43-76 0.27 0.67 0.28 0.18 0.85 0.09 0.26 5.09 2-59 C.49 0.17 0.49 75 per cent of the oil, and a sesquiterpene known as caryophyllene. There are also in cloves a notable amount of fixed oil and resin, and also a peculiar form of tannin. Very few complete analyses of cloves are on record. Richardson { seems to have been the earliest worker in the field to give anything at all satisfactory in the way of a number of determinations of value. The following are maximum and minimum figures from the tabu- lated results of Richardson's analvses: * Winton, Ogden, and Mitchell, Conn. Exp. Sta. An. Rep., 1S98, p. 210. t DooHttle, Mich. Dairy and Food Dept. Bui. 94, 1903, p. 12. J U. S. Dept. of Agric, Div. of Chem., Bui. 13. 414 FOOD INSPECTION AND ANALYSIS. Whole cloves (7 samples): Maximum Minimum Stems ( I sample) Ground cloves (9 samples): Maximum Minimum McGill * gives tables of analyses of pure and adulterated samples of cloves. Analyses of upwards of twenty samples of genuine cloves, both whole and ground, from these tables show the following maximum and minimum figures: Maximum. Minimum. Moisture 11.80 19.63 30.68 10.23 31-40 7.00 5-05 9.24 16.25 0.94 22.23 5-03 Volatile oil Total volatile matter Fixed oil Total extraction Ash McGill also made analyses of whole cloves of several varieties, the following table being a summary of his results: No. of Analyses. Moisture. Total Volatile Matter. Volatile Oil. 8 7-4 24-3 17.2 5-0 20.7 14.8 6.2 22.4 16.2 8 6.7 25-9 19.2 5-5 23-5 18.0 6.1 24.6 18. s 13 6.7 23.6 18-3 4.1 18.6 12. 1 5-7 21.7 16.0 Total Extract- ive Matter. Fixed Oil. Penang cloves: Maximum. Minimum. Mean Amboyna cloves: Maximum. Minimum. Mean Zanzibar cloves: Maximum. Minimum. Mean 28.2 24.4 27.0 29.2 26.5 27-5 28.1 21.3 25-5 9-5 10.8 8.2 9- 10. Maximum and minimum figures of thirteen samples of unadulterated cloves, as purchased from retail dealers in Connecticut and analyzed by Winton and Mitchell, f are as follows: * Canada Inland Rev. Dept. Bui. 73. t Conn. Exp. Sta. Rep., 1898, pp. 176-177 SPICES. 415 Maximum. Minimum. Ash, total 7.92 18.25 7.19 5-99 11-03 4-87 Winton, Ogden, and Mitchell * give more complete analyses of eight .samples of whole cloves of known purity, representing Penang, Amboyna, ,and Zanzibar varieties, and two samples of clove stems, as follows: Moisture. Ash. Ether Extract. Alcohol Extract. Total. Soluble in Water. Insoluble in HCl. Volatile. Non- volatile. 8-26 7-03 7.81 8.74 6.22 5.28 5-92 7-99 3-75 3-25 3-58 4.26 0.13 0.00 0.06 0.60 20-53 17-82 19-18 5.00 6.67 6.24 6-49 3-83 15-58 Minimum 13-99 Mean 14-87 Clove stems, mean 6-79 Reducing Matters by Acid Conver- sion , as Starch. Starch by Diastase Method. Crude Fiber. Nitrogen, X6.2S. Oxygen Absorbed by Aque- ous Ex- tract. Querci- tannic Acid. Total Nitrogen. Maximum 9-63 8.19 8-99 14-13 3-15 2.08 2-74 2.17 9.02 7.06 8.10 18.71 7.06 S-88 6-18 5-88 2-63 2.08 2-33 2-40 20-54 16-25 18.19 18.79 1. 13 Minimum 0.94 Mean 0-99 Clove -stems, mean 0-94 The Tannin Equivalent in Cloves. — The amount of tannin in cloves was shown by Ellis to be so constant as to be of valuable assistance as a guide to their purity. The actual determination of tannin is, however, a long and difhcult proceeding, and Richardson f has pointed out that it is not necessary, but that simply using the first part of the Lowenthal tannin process, and noting the "oxygen absorbed" as expressed by the oxidizing power of permanganate of potash on the material after extrac- tion with ether, is quite as useful as determining the tannin, and is in effect proportional to the tannin present. The result is sometimes expressed as in Richardson's figures above, as the oxygen equivalent, or as quercitannic acid. Determination of Tannin Equivalent.^ — Reagents: Indigo Solution. — Six grams of the indigo salt § are dissolved in 500 cc. of water by heat- * Conn. Exp. Sta. Rep., 1898, pp. 206, 207. t U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 167. X U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 60; Bui. 107 rev., p. 164. § The quality of the indigo used is of great importance since with inferior brands it is 41 6 FOOD INSPECTION AND ANALYSIS. ing. After cooling, 50 cc. of concentrated sulphuric acid are added, the solution made up to a liter and lilLered. Standard Permanganate Solution. — Dissolve 1.333 grams of pure potassium permanganate in a liter of water. This should be standardized by titrating against 10 cc. of tenth-normal oxalic acid (6.3 grams pure crystalhzed oxahc acid in 1,000 cc), diluted to 500 cc. with water, heated to 60° C, and mixed with 20 cc. of dilute sulphuric acid (i : 3 by volume). The permanganate solution is added slowly, stirring constantly, till a pink color appears. Two grams of the material are extracted for twenty hours with pure anhydrous ether. The residue is boiled for two hours with 300 cc. of water, cooled, made up to 500 cc, and filtered. Twenty-five cc. of the filtrate are pipetted into a 1200-cc. flask, 750 cc. of distilled water are added and 20 cc. of indigo solution. The standard permanganate solution is then run in from a burette a drop at a time with constant shaking, until a bright golden yellow color appears, which indicates the end-point. Note the number of cubic cen- timeters required, represented by (a). In a similar manner determine the number of cubic centimeters of standard permanganate solution consumed by 20 cc. of the indigo solu- tion alone, represented by (&), and subtract this from {a). The oxygen equivalent, or, as it is sometimes called, the "oxygen absorbed," is calculated from the equivalent in tenth-normal oxalic acid of the number of cubic centimeters of standard permanganate repre- sented by a — h. 10 cc. of tenth-normal oxalic acid are equivalent to 0.008 gram of oxygen absorbed, or 0.0623 gram of quercitannic acid. Microscopical Examination of Cloves. — Unless the finely powdered, water-mounted sample is well rubbed out under the cover-glass, many Oi the masses of cellular tissue will be too dense to recognize. With a little care, however, it is possible to make a very satisfactory water mount, though by soaking for twenty-four hours in chloral hydrate solution the more opaque masses are rendered very translucent. Fig. 81, from Moeller, shows some of the characteristics of p-^wdered cloves. The outer skin of the calyx tube is shown at (i) with itE, polyg- onal cells and large oil spaces showing through them; (2) shows the epidermis of the outer part of the lobes or wings of the calyx, with stomata impossible to get a sharp end-point. The indigo solution should be made from the very best variety of sulphindigotate, which may be obtained from Grueber & Co., of Leipzig, or Gehe & Co., of Dresden, under the name of carminium coeruleum. SPICES. 417 surrounded by irregularly shaped cells; (3) represents the epidermis of the petals, with crystals of calcium oxalate; a cross-bection of the epi- dermis of the calyx is shown at (4); (5) shows the parenchyma, with calcium oxalate crystals and with one of the slender spiral ducts; (6) and (7) represent in cross-section and longitudinal section respectively the parenchyma of the middle layers of the ovary, one of the rounded, triangular pollen grains being shown at (12). Fig. 81. — Powdered Cloves under the Microscope. X125. (After Moeller.) Characteristics of clove stems, which are frequently used as adulter- ants of cloves, are found in (8), (9), (10), and (11). Stone cells of the outer skin and the inner portion of the clove stem are shown at (8) and (9) respectively; (10) shows one of the vascular ducts, and (11) two of the bast fibers. Both the vascular ducts and the stone cells are very characteristic of clove stems. Pure cloves have no stone cells and comparatively few bast fibers. Stem:j under the micro- scope show a large number of bast fibers and frequent stone cells, the latter being of a distinctly yellow color. A plain water-mounted slide rarely shows all the structural details depicted in Fig. 8i, but is nearly always sufficiently characteristic to 41 8 FOOD INSPECTION AND ANALYSIS. prove the purity of the sample. Fig. 220, PI. XXV, shows the actual appearance of powdered cloves, mounted in water and examined under a magnification of 130. The general appearance of the cellular tissue is that of a loose, spongy mass filled with brown, granular material. Throughout the masses of tissue are to be seen small oil globules. Cloves have no starch whatever. Aside from the stems, cloves are sometimes adulterated with clove fruit or "mother cloves," which have a small amount of a sago-like starch, and also contain some stone cells. Adulteration of Cloves. — The U. S. standard for pure cloves is as follows: Volatile ether extract not less than 10%; quercitannic acid, cal- culated from the total oxygen absorbed by the aqueous extract, should not be less than 12%; total ash should not exceed 8%; ash insoluble in hydrochloric acid should not exceed 0.5%, and crude fiber should not be more than 10% • Clove Stems are v^ry frequent adulterants of cloves and possess some slight pungency. They are commonly identified under the microscope by the large number of bast fibers and stone cells, and should not be found in pure cloves in excess of 5%. Allspice, being considerably cheaper than cloves, is sometimes used as an adulterant. It is readily recognized by the characteristics described on page 422. Other Adulterants commonly found are cereal starches (especially corn and wheat) and ginger (for the most part "exhausted"). Besides the above, pea starch, rice, turmeric, charcoal, sand, pepper, ground fruit stones, and sawdust have been found in samples of cloves examined in Massachusetts. Exhausted .Cloves, both whole and in powdered form, are not infre- quently found on the market. These have been deprived of a portion of the volatile oil, and are much less pungent than the pure article, so that the difference in taste between the two varieties is quite marked. It is, however, rare that powdered cloves are sold consisting entirely of the exhausted variety, the more common practice being to mix from ID to 25 per cent of exhausted cloves with the pure powder, so that the sophistication is less apparent. A determination of the volatile oil is the only reliable means of show- ing whether or not the material has been wholly or in part exhausted, though Villier and Collin claim that under the microscope an exhausted sample of cloves shows the oil glands to be nearly empty, or to inclose much smaller droplets of oil than the pure variety. SPICES. 419 With the exception of exhausted cloves, the presence of nearly every foreign ingredient is best and most quickly shown by the use of the microscope, though much information as to the purity of the sample can be gained by the ether extract, the percentage of ash, and of crude fiber.* Cocoanut Shells. — Figs. 226 and 227, PI. XXVII, show samples of cloves adulterated Avith ground cocoanut shells. The long, spindle-shaped, yellow- brown and deeply furrowed stone cells of the adulterant with their thick walls and central branching pores are unmistakable. The dark-brown contents of the cells turn reddish brown when treated with potassium hydroxide. The anatomy of the cocoanut, including the shell, has been carefully studied by Winton.f Fig. 82, after Winton, shows elements of powdered cocoanut shell under the microscope, st are the dark, elongated, yellow, porous stone <^^^ Fig. 82. — Cocoanut-shell Powder. si, dark-yellow stone cells with brown contents; /, reticulated trachea; sp, spiral trachea; g, pitted trachea; w, colorless, and br, brown, parenchyma of mesocarp; /, bast fibres, with stegmata {ste). Xi6o. (After Winton.) cells with their brown contents, these stone cells being the most dis- tinctive characteristic of the ground shells. /, sp, and g are the various forms of trachea; w and br are respectively colorless and brown paren- chyma of the mesocarp or outer coat, portions of which always adhere to the nutshell and are ground with it. * Note especially the sharp distinction between these values in the case of pure cloves and of clove stems in Richardson's table. t The Anatomy of the Fruit of the Cocoanut. Conn. Exp. Sta. Rep., 1901, p. 208. 42o FOOD INSPECTION AND ANALYSIS. Fig. 264, PI. XXXVI, shows a photomicrograph of powdered cocoanut shells, mounted in gelatin. The long, spindle-shaped stone cells are especially apparent, Ground cocoanut shells have been used in various spices besides cloves, especially allspice and pepper. In the following tabulated results of analyses by Winton, Ogden, and Mitchell * are shown the wide deviation between the chemical constants of cocoanut shells and several of the spices in which they appear as adulterants. Black Pepper. Cloves. Allspice. Nutmeg. I Cocoanut Shells. Water Total ash. Ash soluble in water Ash insoluble in hydrochloric acid Volatile ether extract Non-volatile ether extract Alcohol extract Reducing matters, as starch, acid conversion Starch by diastase method Crude fiber Total nitrogen Oxygen absorbed by aqueous extract Quercitannic acid equivalent II 96 4 76 2 54 47 I 14 8 42 Q 62 3« 63 .S4 15 M 06 2 26 7. SI 5-92 3-58 0.06 19.18 6.49 14-87 8.99 2.74 8.10 0.99 2-33 18.19 9.78 4-47 2.47 0.03 4-05 5-84 11.79 18.03 3-04 22.39 0.92 1.24 9.71 2.28 0.86 0.00 3.02 36.70 10.77 25-56 23.72 2-51 •36 •54 -50 .CO .00 •25 0-73 56.19 0.18 0.23 1.83 ALLSPICE, OR PIMENTO. Nature and Composition. — Allspice is the dried fruit of the Eugenia pimenla, an evergreen tree belonging to the same family (Myrtacea;) as the clove. It is indigenous to the West Indies, and is especially cul- tivated in Jamaica. The allspice berry is grayish or reddish brown in color, and is hard and globular, measuring from 4 to 8 mm. in diameter, being surmounted by a short style. This is imbedded in a depression, and around it are the four lobes of the calyx, or the scars left by them after they have fallen off. The berry has a wrinkled, ligneous pericarp, with many small excrescences filled with essential oil. The pericarp is easily broken between the fingers, showing the berry to be formed of two cells with a single, brown, kidney-shaped seed in each, covered with a thin, outer coating, inclosing an embryo rolled up in a spiral. The berries are gathered when they have attained their largest size, but before becoming fully ripe. If allowed to mature beyond this stage, some of the aroma is lost. * Conn. .\g. E.xp. Sta. Rep., 1901, p. 225. SPICES. 421 Though considerably less pungent than other spices, allspice possesses an aroma not unlike cloves and cassia. In chemical composition it most resembles cloves, containing both volatile oil and tannin; but, unlike cloves, it contains much starch, the starch being contained in the seeds. The volatile oil of allspice is very similar to clove oil. It is shghtly lasvo- rotary, and is composed of eugenol and a sesquiterpene not determined. It is present in allspice to the extent of 3 to 4.5 per cent. The boihng- point of the oil is 255° C. Authoritative full analyses of allspice are even more meager than of cloves. Analyses of one sample of whole allspice and five samples of the ground spice, made by Richardson,* are thus summarized: ^ c ■d u < •0 |5 U . •§-•5 c 1^ a m 60 s 13 G > 'B 3 Mo" 6^ Whole 6.19 4.01 5-15 6.15 59.28 14.83 4.38 .70 10.97 2 8i Ground: Maximum 8.82 5-53 3-32 6.92 58.24 18.98 5-42 .87 12.74 3-36 Minimum 5-51 3-45 2.07 3-77 56.86 13-45 4-03 .64 8.27 2.12 Seventeen samples of unadulterated allspice, as sold on the Connect- icut market, were analyzed by Winton and Mitchell ,t with maximum and minimum results as follows: Ash. Maximum. Minimum. Total 7-51 •95 3-50 6.22 4-34 .40 1-34 3-78 Insoluble in hydrochloric acid (sand) . . Ether extract, volatile Ether extract, non-volatile Three samples of pure whole allspice were more fully analyzed by Winton, Mitchell, and Ogden with the results given on page 42 2. | The Tannin Equivalent in Allspice. — Tannin is present in allspice, though to a less extent than in cloves. The exact amount present is rarely determined, but rather the "oxygen equivalent," or quercitannic acid, as explained on page 415, the determination being carried out as there detailed. * U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 229. t An. Rep. Conn. Exp. Sta., 1898, pp. 178, 179. ^ Ibid., pp. 208, 209. 422 FOOD INSPECTION AND ANALYSIS. Moisture. Ash. Ether Extract. Alcohol Total. Soluble in Water. Insoluble in HCl. Volatile. Non- volatile. Extract. 10.14 9-45 9-78 4.76 4-15 4-47 2.69 2.29 2.47 0.06 0.00 0.03 5.21 7.72 3-38 4-35 4-05 5.84 14.27 7-39 11.79 Minimum ............ Average .............. Reducing Matters by Acid Conver- sion, as Starch. Starch by Diastase. Crude Fiber. Nitrogen, X6.25. Oxygen Absorbed by Aque- ous Ex- tract. Querci- tannic Acid. Total Nitrogen. Maximum 20.6^. 16.56 18.03 3-76 1.82 3-04 23.98 20.46 22.39 6-37 S-19 5-75 1-59 1.03 1.24 12.48 8.06 9.71 1.02 Minimum 0.83 0.92 Average Microscopical Examination of Powdered Allspice. — By soaking the powder twentv-four hours or more in chloral hydrate, many of the harder portions are rendered much more transparent than would otherwise be possible. Fig. 83, after Moeller, shows the microscopical structure of various elements that go to make up allspice powder. The epidermis, or outer layer of the berry with its small cells, is shown in cross-section at (la) and in surface \aew at (2). Just beneath the outer coat are the large oil spaces (ib) and still further below the stone- cells (ic). The fruit parenchyma (3) has vascular tissues running through it. (4) and (5) are the inner epidermis and stone cells of the dividing partitions between the seeds. Small hairs connected with the outer epidermis are shown at (6). (7) and (8) show in cross-section a portion of the seed-shell and inclosed seed or embryo, with the starch (8a) and the colored lumps of gum or resin (Sb) of a port-wine color. These colored cells exist in the seed coating, and, although only one is here shown, constitute a very important and striking characteristic of allspice. (9) represents the spongy parenchyma of the seed shell, and (10) shows its epidermis. In the parenchyma of the fruit and of the partitions between - the cells are seen, but not always plainly, minute crystals of calcium oxa- late (see (4) and (5)). These details so closely drawn by Moeller are idealized, but serve well to indicate what should be looked for. In practice the water- mounted specimen shows all the characteristics necessary to identify pure allspice, and most if not all its adulterants. In fact pimento is one of the easiest spices to identify under the microscope, by reason of its striking characteristics. SPICES. 423 Three distinctive features are especially typical, viz. : First, the starch grains, which are very uniform in size, measuring about 0.008 mm. in diameter, being nearly circular as a rule, and often arranged in groups not unlike masses of buckwheat starch. Ordinarily these masses con- tain fewer granules than do those of buckwheat. The granules are Fig. 83.— Powdered Allspice under the Microscope. X125. (After Moeller.) smaller and more inclined to the circular than to the polygonal form, while in many cases they have distinct central hila. The starch grains are very numerous and are found in nearly every field. See Fig. 195, PI. XIX. A second distinctive feature of allspice is the stone cells, of which there are many. These are more often colorless, and in most cases very large and plainly marked. They are sometimes seen singly and at other times grouped together. Frequently they are attached to pieces of brown, parenchyma. 424 FOOD INSPECTION AND ANALYSIS. The third and most characteristic feature of allspice powder under the microscope is the striking appearance of the lumps of gum or resin, which are of a more or less deep port-wine or amber color and are con- tained in the middle layers of the seed coat. These cells are very striking, occurring sometimes in isolated bits, and in other cases in aggre- ga lions of from 2 to 4 or even 6 to 8 cells. These resinous lumps appear plainly in Fig. 194, PI. XIX. Droplets of oil are occasionally seen, but noL ni profusion. As a rule the oil is forced out of its large containing cells and into the surrounding tissue by the process of drying. Adulteration of Allspice. — i\ccording to the U. S. standard for all- spice, quercitannic acid should not be less than 8%, total ash not more than 6%, ash insoluble in hydrochloric acid not more than 0.5%, crude fiber not more than 25%. The most common adulterants found in powdered allspice are cocoanut shells and the cereal starches. Besides these the writer has found in Massachusetts, peas, pea hulls, exhausted ginger, cayenne, olive stones, pepper, and turmeric. To this list may be added clove stems, which are on record as a not uncommon adulterant in some localities. All of these are to be readily recognized by a care- ful microscopical examination. CASSIA AND CINNAMON. Nature and Composition. — The terms cassia and cinnamon are interchangeable in commerce, though, strictly speaking, they represent two separate and distinct species of the genus Clnnamomum, belonging to the laurel family {LauracecE). True cinnamon is the bark of Clnna- momum zcylanicum, a tree from 20 to 30 feet high, having horizontal or drooping branches, and native to the island of Ceylon, but cultivated also in some parts of tropical Asia, in Sumatra, and in Java. The entire yield of pure Ceylon cinnamon is extremely small, and but Httle of it is found in this country. It is the very thin, inner bark of the tree, and is of a pale, yellowish-brown color, being found on the market in long, cyhn- drical, quill-like rolls or pieces, the smaller rolls being inclosed in the larger. The outer surface is marked by round dark spots, correspond- ing to points of insertion of the leaves, and it is also furrowed length- wise by somewhat wavy, light-colored lines. The inner surface of the bark is darker colored, and has no lines. In thickness the bark varies from 1.5 to 3 mm. Both the inner and outer coatings of the bark of Ceylon cinnamon are usually removed in the process of preparation, so SPICES. 425 that it is of a much cleaner and more even texture than the cassia bark, which is thicker and heavier by reason of the outer cork layer usually left on it. The cheaper and more common cassia is the bark of the Cinna- momum cassia, which comes from China, Indo-China, and India. It is of a darker color than that of cinnamon, of coarser texture, and as a rule about four times as thick. Most varieties of cassia bark are less tightly rolled than cinnamon, and are not arranged one within the other in layers. The outer surface is marked by elUptical spots left by the leaves, and by small, dark-brown, wart-Uke protuberances. Cassia does not have the wavy, Hght-colored hnes found in the cinnamon. Both cinnamon and cassia barks are very aromatic in taste, somewhat astrin- gent, and slightly sweet. Cassia buds are the dry flower buds of China cassia, and are found in the market both in whole and in powdered form. Powdered cassia often consists of a mixture of several varieties of bark, while the cheaper grades sometimes contain an admixture of the ground buds. The best grade of cassia is that from Saigon, a much cheaper, from Batavia, while the cheapest is the China cassia. The odor of cassia and cinnamon bark is due to the volatile oil, of which from i to 2 per cent is usually found. Cassia and cinnamon oil greatly resemble each other, the principal constituent in either case being cinnamic aldehyde, CgH^CH: CH.CHO. Besides this^one or more esters of acetic acid are present. Both oils are very pungent and intensely sweet. Starch is present in cassia to the extent of from 16 to 30 per cent. A very small amount of tannin is found, as well as cinnamic acid and mucilaginous matters. Cassia buds are somewhat similar in com- position to the bark. They have, however, less starch and crude fiber, and higher contents of volatile oil and nitrogen than the bark. Richardson * has made analyses of a few samples of pure whole cinna- mon and cassia, from which the following are taken: u 0) la < |5 •d.S Nitrogen. Ceylon cinnamon, i 5-40 7-43 4-79 17-45 9-32 4-55 3-40 5-58 8.23 2.48 1.05 .82 3-59 3-51 -55 1.66 1.58 S-21 2.38 -74 33-08 25-63 8.60 26.29 14-33 2.98 3.80 7.00 4-55 2.63 51.28 56.84 65-23 65-33 48.65 .48 62 " '' 2 Cassia bark (4 samples) : Maximum .73 .42 Minimum * U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 221. 426 FOOD INSPECTION AND ANALYSIS. Winton, Ogden, and Mitchell's * results of analyses of whole samples of cinnamon, cassia, and cassia buds are thus summarized: Moistiire. Ash. Total. Soluble in ' Water. Insoluble in HCl. Ether Extract. Volatile. Non- volatile. Ceylon cinnamon (6 samples) Maximum Minimum Average Cassia bark (20 samples): Maximum Minimum Average Cassia buds (2 samples): Average 10.48 7-79 8.63 II. 91 6-53 9.24 7-93 5-99 4.16 4.82 6.20 3.01 4-73 4.64 2.71 1.40 1.87 2.52 0.71 1.68 2. 88 0.58 0.02 0.13 2.42 0.02 0.56 0.27 1.62 0.72 1-39 5-15 0-93 2.61 1-35 1-44 4-13 1.32 5-96 Alcohol Extract. Reducing Matters by Acid Conversion as Starch. Crude Fiber. Nitrogen, X6.2S. Total Nitrogen. Ceylon cinnamon (6 samples) : Maximum Minimum Average Cassia bark (20 samples): Maximum Minimum Average Cassia buds (2 samples): Average 13.60 9-97 12.21 16.74 4-57 8.29 22.00 16.65 19.30 32.04 16.65 23-32 10.71 38.48 34-38 36.20 28.80 17-03 22.96 13-35 4.06 3-25 3-70 5-44 3-31 4-34 7-53 0.65 0.52 0-59 0.87 0-53 0.69 Structure of Powdered Cassia under the Microscope. — Fig. 84, from Moeller, shows various elements of cassia bark as veiwed microscop- ically, (i) shows in cross-section a portion of the cork and outer layer of the bark rind, with flat cells nearest the surface, having somewhat thick walls and reddish-brown contents, and, farther in, the cells s, with mucilaginous material. The stone cells of the intermediate layer of bark are shown at (2).' Here the tendency of the stone cells is to be thicker on one side than on the other, as is plainly shown. (3) represents the structure of the inner layer of the bark, showing bast fibers h cut across, and more of the so- called mucilaginous cells s of large size, which normally contain the ethereal or volatile oil. The starch granules (4) are contained in great abundance in the polygonal cells of the parenchyma of the intermediate ♦ Twenty-second Annual Report Conn. Exp. Sta., 1898, pp. 204, 205. SPICES. 427 and inner bark layers. (6) represents a fragment of a bast fiber, which is often shown in cassia powder with connecting parenchyma. The stone-cells of the cork are show^n in plan view at (7). Very small, needle- like crystals of oxalate of calcium are occasionally to be seen if looked for carefully. They occur in the parenchyma cells of the inner and inter- mediate layers of the bark. The microscopical structure of Ceylon cinnamon much resembles that of cassia. Cassia starch grains measure from 0.0132 to 0.0222 mm., Fig. 84.' — ^Powdered Cassia under the Microscope. X125. (After Moeller.) being considerably larger and more abundant that those of true cinnamon. As a rule the bast fibers of cassia are larger, but shorter, than those of cinnamon, and provided with thicker walls. Figs. 203 and 204, PI. XXI, show various phases of pure cassia bark as photographed from water-mounted specimens of the powder. Cassia starch somewhat resembles that of allspice, but it is not as a rule found in masses containing as many granules as does the allspice starch. Very conmionLy two or three of the starch granules are arranged together in 42S FOOD INSPECTION AND ANALYSIS. such a manner that at first sight they appear to form a single large granule, but on more careful examination are seen to be two- and three -lobed, consisting of several smaller grains. Stone cells, which are very abundant in the powdered cassia, do not happen to be included to any extent in the photographed fields. Cassia stone cells are generally more oblong than those of allspice, and are more often brown in color, while the allspice stone cells are generally colorless. A distinctive feature of powdered cassia consists in the long, amber- colored wood fibers, some distributed in bundles, and others arranged singly. These are very clearly shown in Figs. 204 and 205. Yellow patches of cellular tissue with starch grains interspersed among them are very abundant in the powder. Adulteration of Cinnamon and Cassia.— The U. S. standards are as follows: Total ash not to exceed S'/^ ; sand not to exceed 2%. The commonest adulterants are cereal products and foreign bark. Besides these, the writer has found, in samples sold in Massachusetts, leguminous starches, pea hulls, nutshells, turmeric, pepper, olive stones, ginger, mustard, and sawdust. Much of the China cassia when imported contains an inexcusably large amount of dirt. In one sample Winton, Ogden, and Mitchell found over 15% of sand. Ground Bark of the Common Trees, especially that of the elm, resembles in physical appearance ground cassia, and is to be looked for as an adulterant. Fig. 265, PI. XXXVII, shows the appearance of ground elm bark. The fibers of cassia bark have starch granules as a rule interposed among them, while the foreign bark, usually of a much coarser texture, shows no starch connected with its structure. Fig. 206, PI. XXII, shows a water-mounted specimen of adulterated cassia powder, chosen from samples purchased in the Massachusetts market. Nothing but the adulterant (a foreign bark) shows in the field. The tissue is loose and considerably coarser than that of cassia bark. PEPPER. Nature and Composition. — Pepper is the dried berry of the pepper plant {Piper nigrum), a climbing shrub belonging to the family Pipe- racecB, native to the East Indies, but cultivated in many tropical countries. The height of the pepper plant is from twelve to twenty feet. When the fruit begins to turn red, it is gathered and then dried, by which process it turns black and shrivels up, forming the black peppercorns of com- merce. They are spherical single-seeded berries, about 5 mm. in diam- SPICES. 429 eter, covered with a brownish-gray epicarp, and having on the under side the remains of a short stem. At the top of the berry is an indistinct trace of a style, and of a lobed stigma. Varieties of black pepper are named from the localities in which they are grown or from which they are shipped, as Singapore, Lampong, Sumatra, Tellichery, Malabar, Acheen, Penang, Alleppi, Trang, Man- galore, etc. White pepper is obtained by decorticating the fully ripened black peppercorns, or removing the dark skin. This is accomplished by mac- erating them in water to loosen the skin, which is then removed readily by drying and rubbing between the hands. White whole pepper grains are grayish white, and a trille larger than the black pepper berries. They are nearly spherical in shape, and have a number of light-colored lines that, like- meridians, run from top to bottom. The common varieties are Siam, Singapore and Penang, the latter being coated with lime. The pungent taste of pepper is due in great part to its essential oil, a hydrocarbon of the formula CioHig, present in amounts varying from 0.5 to 1.7 per cent. Pepper oil contains phcUandrene and a terpene. Other important constituents of pepper are piperidine, and the crys- talline base piperin, CjyHigNO.-?, insoluble in water, but soluble in ether, and in alcohol. Starch is present in pepper to a large extent. Burcker gives the following average percentage composition of black and white pepper: m u"^ "d u 1^ ^ 12.50 11.98 1.36 6.85 42.90 13-56 II. 12 0.94 7. II 56.04 o o bo V !-• O -^ (U u +-> Black pepper . White pepper. 4-57 12.45 6.08 7-39 3-35 Richardson's * analyses of three samples of whole black and two samples of whole white pepper, all pure, are as follows: Black pepper: White pepper: Water. Ash. 8.91 8.29 9-83 9-85 10.60 4.04 4.70 3-7° 1. 41 1-34 Volatile Oil. -70 West coast. . . Acheen Singapore. . .. West coast. . . Singapore . . . * U. S. Dept. of Agric, Bur. of Cham., Bui. 13, part 2, p. 206. 1.60 -57 1.26 Piperin and Resin. Alcohol Extract. 7.29 7.72 7-15 7.24 7.76 h'.'o'e 5-74 2-57 Starch (Acid Con- \ ersion) . 36-52 37-50 37-30 40.61 43.10 43^ FOOD INSPECTION AND ANALYSIS. Undeter- mined. Crude Fiber. Albumin- oids. Total NX6.2S. Total N. Black pepper: West coast Acheen. . . Singapore . White pepper: West coast, Singapore . 24.62 13.64 17.66 23.28 19-55 10.23 10.02 10.02 7-73 4.20 7.69 10.38 10.00 9-31 9.62 9.»i 12.60 12.08 11.48 11.90 1-57 2.02 1-93 1.83 1.90 Richardson gives the following variations in the constituents of pure pepper : Black. White. Water 8.0 to 11. 2.75 to 5.0 .50 to 1.75 7.0 to 8.0 32.0 to 38.0 8.0 to 1 1 . 7.0 to 12.0 8.0 to II. 1 . to 2.0 .50 to 1.75 7.0 to 8.0 40.0 to 44.0 4. II to 8.0 8.0 to 10. Ash Volatile oil Piperin and resin. Albuminoids. McGill's * analyses of six samples of whole black, and five samples of whole white pepper, all genuine, are thus summarized: Moisture, etc., Lost at 100° C. Ash. Soluble in Hot Water. Insoluble in Water. Total. Insoluble in Hydro- chloric Acid. Sand Expressed as Per Cent of Total Ash. Alcohol Extract. Black: Maximum Minimum Mean 14.10 10.62 12.03 13.00 11.30 12.34 2.64 2.07 2.41 0.72 0.14 0.54 3.06 1.46 2.05 3-04 1-50 2.46 5. 16 3-98 4-47 3-65 1.64 3.00 1.08 .06 0.36 0.88 0.26 0-55 21 2 8 42 9 21 9.06 8.28 8.71 White: Maximum Minimum Mean 8.92 7.00 7-73 Winton, Ogden, and Mitchell's, and Winton and Bailey's f analyses of whole black pepper and whole white pepper, representing the leading varieties imported into the United States, also of pepper shells and long pepper, are summarized in the following table: * Canada Inl. Rev. Dept. Bui. 20, 1890. t An. Rep. Conn. Exp. Sta., 1898, pp. 198-199; 1903, pp. 158-164. SPICES. 431 M t-» \r> QO Oi ^^ eo N rt- O r- ^to O ir, O. N 1 ■^oBJixa J9ma COM ro^Of^ro'30"5ieq rO<^HNi3oO'~< Mwdc-^oo"^wc< Ns S3| -uaSojiii^i pioj, rf r^ r^ o!£i ^ ®* M 0'^'~*^VOt^vO o M MOO i^vo'to'^oo 000 >-i P >~H ?-; 10 Wi rn n i^itoC)©* MOO M o'to'~H^io asBiSBtQ Aq qaJB^g 06 t-^i^rON l^Oi^jeo r^rf)vd ■*SOSOto lOPJ d\ vOmu^io^O'Ciitii-' f^ •qojB^s SB t--. t^ M t^^ ''S "^ \o M M t~-®^ eo i^ O^ ro 00 oq^qvq ^ m o^*-<©* °° t^-q '-j^^t"'"^'^ "t °°. 'U0ISJ3AU03 PPV •^ \d ONt^^itooi M M M On w Tl-O wiJO >~i ^ i-OU-,vO oj'CiOito r^ oooq '& q '^"^°o®r)^ 0C3 ■* ro <~0l<5 '"J to ro q vq ■iDBJjxa loqooiv 0606 d^d (>d>-^o6oi -1 " »~i 1^06 r--t^Oot^j^^ ■«i-o6 1 CO Tj- r^ t^ 0^ On ^ ^ ■**^ ^ov'^N;:3-to>~i r^M-M •aipBiOA-uo^ l^OlOM lonSOOO"^ w oc vq rooi ^ Oi Ov q vq 1^ rir^vdot^toto Tfrovd ^O row Ovav--<0i-iM>~iOO dd d dooo 4n d lOt^oO MvoO'^d t- rooo "oO 09 ^^ 00 U3;bjW ui aiqnjog M t^rot^OO^t^'to TtrorO\OQ0®*~^'3iO vO i^'^'*$P5?t^ M lof^ •I«?ox •^ N q q vq ovoo '-h M M M N®;!*-I->~i M'd*'' M M OvO^O OwoO^^^to Ovt^<^o0^®*^0 p< r^ •gjnjsioj^ q •^■^q ^i^OiQqoo 00 ^<30^«^^vq lOTj- MMl-lMMM>^-^-^ M ror^rO^SvJeo O" 6 On ■sajduiBS JO Jsqutn^ IT) M Tt M ro 10 N N CO ro O fO w 11 aj 1) 60 bO 6C ID 1) C r- ajflM Cm bCbObOMSc SS ,■3 rt ni rt rt P 3 u rtRicSrt3M(llDM U Ui ^ 4.' D > > > > p •« 2 < < < ^ ^< ^^<^ ^ ID 1- a. a, ?^ D, a, cu CI ID sx Ph w PL, -d ui ^ cu /^ >> * OJ aj ID o ui ■ 1 a: Igapore Uicherr mpong been A been B been C varieti IS II 6, C ariet Shei; Long ID Ji Deco Singa Siam Pena All V pper bole '. J3 .1- oj rt u u — C/3 H h-1 < < < < J3 ^ ^ Ph ^ 1 432 FOOD INSPECTION AND ANALYSIS. The following table summarizes the results of full analyses of pepper and pepper shells recently made by Doolittle :* No. of Samples. No. of Varieties. Black pepper: Maximum. . . Minimum . . . Average White pepper: Maximum . . . Minimum . . . Average Long pepper: Maximum. . . Minimum . . . Pepper shells: Maximum. . , Minimum. .. 45 Mois- ture. 11.96 8.09 9-54 13-34 8.04 9.87 10.13 8.43 II. 01 7.00 Ash. Total. 8.04t 3-43 4.99 4.28 0.86 1.69 14-39 6.12 7.82 Insoluble in HCl. 2 - 59t 0.05 0.58 0.86 0.05 0.19 5.92 0.45 22.90 0.79 Soluble in Water. 5-32 1.65 2.49 1. 16 0.12 0-34 4-39 1.72 4.66 1-53 Starch by Diastase Method. 41-75 25.09 36.69 63-55 48.88 54-37 45-87 28.43 11.70 9.28 Black pepper: Maximum . . Minimum . . Average White pepper: Maximum. . Minimum . . Average Long pepper: Maximum . . Minimum . . Pepper shells: Maximum . . Minimum . . Ether Extract. Volatile. 1.30 1.66 0.78 1. 17 1. 01 0.79 Non-vola- tile. 10.44 6.60 7.67 7.26 5-65 6.46 7-53 5-71 4.67 1-51 Crude Fiber. 10.05 II. 12 7-65 0.10 4-17 10.01 7.19 28.22 21 .06 Nitrogen. Total. 1.86 2. II 2.14 1.85 1-97 2.04 2.13 1.82 1.72 In Non- volatile Ether Extract. Total N less N in non-vola- tile Ether Extract X6.2S. , 0-45 0.25 0.31 0-34 0.24 0.30 0.18 13.12 9-25 11.20 11.56 9.69 IC.44 12.06 11-37 11.25 10.00 t Two samples of Acheen C pepper had a total ash of 8.00% and 8.04%, with ' 'ash insoluble in HCl" if 2.50% and 2.40% respectively. Eliminating these two samples, which were evidently abnonaally_ high in sand and dirt, the highest total ash of the remaining 43 samples was 7.00%, while vhe highest ash insoluble in HCl was 1.80%. Determination of Nitrogen in Black and White Pepper. — Winton, Ogden, and Mitchell have shown that the Kjeldahl and Gunning methods are inapplicable in the case of pepper, owing to the presence of piperin, bui that the Gunning-Arnold t method gives accurate results. In accord- ance with this method, i gram of the sample is mixed with a gram each of copper sulphate and red oxide of mercury, about i6 grams of potassium * Mich. Dairy and Food Comm. Bui. 94. + Zeits. anal. Chem., 31, i8p2, p. 525. SPICES. 433 sulphate, and 25 cc. of sulphuric acid in a Kjeldahl flask, for both diges- tion and distillation, of about 600-cc. capacity. The heating is conducted in the usual manner, beginning with a gentle heat till the frothing ceases, and gradually increasing the temperature till the mixture boils. The boiling is continued for three or four hours, after which the flask is cooled, and to it are added 300 cc. of w^ater, 50 cc. of potassium sulphide solution,* and enough of a saturated solution of sodium hydroxide to render the reaction alkaline. The flask is then connected to the condenser, and the distillation con- ducted as in the Gunning method (p. 69), using zinc dust to prevent bumping, receiving the distillate into standard acid, and titrating against standard alkali. Nitrogen Determination in the Ether Extract. f— Ten grams- of the sample are extracted with absolute ether for twenty hours in a con- tinuous-extraction apparatus, the extract being collected in a tared Kjel- dahl extraction- and distillation-flask, the same as used in the preceding section. The ether is then evaporated off, the residue dried to constant weight at 110° C. and its weight ascertained. The nitrogen is then determined in the ether extract by the Gunning-Arnold method. Determination of Piperin.J — Fifty grams of the sample are thoroughly exhausted with hot alcohol, and the alcohol extract evaporated to dry- ness. The dry residue is then treated with a solution of potassium hydroxide, and washed upon a filter. The residue is washed several times with the caustic alkali, which dissolves the resinous matters, and afterwards with water. It is then dissolved in alcohol, from which crystals of crude piperin separate on evaporation. These are redissolved in alcohol, and precipitated by the addition of water. The crystalline pre- cipitate is collected on a tared filter, washed with water, dried, and w^eighed. Piperin may be roughly estimated by multiplying the nitrogen in the ether extract by the factor 20.36. The amount of piperin varies considerably, ranging in black pepper from 4 to 9 per cent. Microscopical Characteristics of Ground Pepper. — Moeller's repre- sentation of powdered black pepper shows what should be looked for under the microscope with the best conditions (Fig. 85). The shell of the peppercorn, a cross-section of which is shown at (i), consists of the * Forty grams KjS in i liter or water. t Method of Winton, Ogden and Mitchell. X Villiers et Collin, Substances Alimentaires, p. 371. 434 FOOD INSPECTION AND ANALYSIS. epidermis, a, under which is a thin layer of brown parenchyma, c, while below this layer is shown the most characteristic portion of the pepper shell, viz.: the thickened, colored, stone cells, h. These are as a rule inclined to be rectangular rather than rounded. hX d is shown a bit of the colorless parenchyma of the fruit itself. (2), (3), and (4) show a cross-section of the outer part of the berry, (2) representing the inner stone-cell layer, a single row of horseshoe-like cells, (3) the thin seed coat, and (4) the white perisperm, with its large cells. Here and there through the perisperm certain yellow contents are visible, consisting largely of resinous matter. A dark resin cell is shown at (4). The ethereal oil, starch, and piperin are found in this part of the beriy. (5) shows in surface view the mostly rectangular stone cells of the pepper shell, resting upon the epidermis (6). Groups of stone cells are frequently thus found with portions of the epidermis. The inner rounded, or cup-shaped cells are shown in plan view at (7) and the seed skin at (8), masses of starch and separate starch granules are shown at (9), and crystals of piperin at (10). The bast-parenchyma of the pepper stem is shown at (11), pieces of which are commonly found in powdered pepper, and (12) shows a fragment of one of the many-celled hairs which grow on the stem. The rounded cup cells (7) are readily distinguished from the more rectangular stone cells (5). The walls of the cup cells are nearly always colorless, and the cells themselves empty.* A water-mounted specimen of finely ground, black pepper, when viewed microscopically, shows most of the elements above described, at least in fragmentary form, though, in the case of the coarser particles. Fig. 85.' — Powdered Black Pepper under the Microscope. X 125. (After Moeller.) * The harder portions of the pepper, especially of the shell, are best examined by soak- ing for at least twenty-four hours in chloral hydrate, and mounting in this reagent on the slide. SPICES. 435 by no means as clearly as by the use of chloral hydrate. Large polyg- onal masses of starch appear grouped as photographed in Fig. 256, PL XXXIV, if not rubbed out too fine under the cover-glass. Starch, in- deed, is the most conspicuous element of pepper, being distributed more or less evenly throughout the mass. The powder may, however, be so finely reduced by abrasion under the cover-glass as to break up these starch masses wholly or in part, so that the granules may appear in much smaller groups or even singly. Fig. 255 shows such a field under a higher magnification. The individual granules of pepper starch average 0.003 "^^'^- '^^ diameter. Besides the starch, and next to it the most numerous, one finds in the water-mounted black-pepper specimen many of the dark -yellow, thick- walled stone cells, patches of the colored parenchyma, and epidermis of the shell. Other elements of the perisperm, besides the starch, are seen in fragments, such as bits of resin, small droplets of oil, pieces of stems, and occasionally the needle-shaped crystals of piperin. Some of the rounded, cup-shaped cells are also usually found. White pepper contains, of course, the same elements, but without the deeply colored stone cells and other characteristics of the shell, which has been removed from it. Adulteration of Pepper. — The following U, S. standards for pepper have been adopted: For white pepper, non- volatile ether extract should not to be less than 6%; starch should not be less than 50% by the diastase method; total ash should not be more than 4%; ash insoluble in hydro- chloric acid should not exceed 0.5%; crude fiber should not exceed 5%. One hundred parts of the non-volatile ether extract should contain not less than 4 parts of nitrogen. For black pepper, which should be free from added pepper shells, pepper dust, and other pepper by-products, non-volatile ether extract should not be less than 6%; starch by the diastase method should not be less than 25%; total ash should not exceed 7%; and crude fiber should not exceed 15%. One hundred parts of the non- volatile ether extract should contain not less than 3.25 parts of nitrogen. The adulterants used in ground pepper are many and varied. Pepper Shells, which have been removed from the white pepper of commerce, are not infrequently ground and added to the cheaper grades of black pepper. When a sample of black pepper is shown by the micro- scope to contain more shells in proportion to the other elements than could be possible in a ground whole berry, added shells are indicated. 436 FOOD INSPECTION AND /INALYSIS. The analyst should, for comparison, grind in a mortar single berries of various grades, and familiarize himself with the appearance of the ground powder under the microscope, when the maximum amount of shells possible under natural conditions are present, noting especially the appar- ent number of stone cells of the outer coating. The familiar title of P. D. (pepper dust) originally given to ground pepper shells, stems, and "sweep- ings " is now applied in the trade not only to almost any cheap and appro- priate material for admixture with pepper, but also, in a broader sense, to ground powder suitable as an adulterant for any spice. The presence of pepper shells is indicated by an excess of ash, sand, and crude fiber, and a deficiency of starch. Hilger and Bauer, also Hanus and Bien, advocate the determination of pentosans as a means of detecting pepper shells. Ground Olive-stones constitute one of the most commonly found foreign materials used as an adulterant of pepper. The powder, sometimes called "poivrette," is very like white pepper in appearance, is wholly inert in taste, and thus forms an admirable adulterant. While best detected by their characteristic appearance under the microscope, the presence of ground olive stones may be shown by color tests with certain chemical reagents. Pabst has adopted for this purpose a test first suggested by Wurster for the detection of wood pulp in paper. The reagent is prepared as follows: In a porcelain capsule lo grams of commercial dimethyl anilin are mixed with 20 grams of pure concentrated hydrochloric acid, and at least 100 grams of cracked ice are added. Then, while stirring, a solution of 8 grams of nitrite of soda in 100 cc. of water are added little by little, and the mixture allowed to remain for half an hour, after which 30 or 40 cc. of hydrochloric acid are added, and 20 grams of tin-foil. The reduction is allowed to go on for half an hour, heating on the water- bath, if necessary. The tin is then precipitated by granulated zinc, the hquid is filtered, and the filtrate neutralized with carbonate of potassium or sodium to the point of forming a precipitate, the precipitate being dissolved by a few drops of acetic acid. Finally the volume is made up with water to 2 liters, adding, before doing so, 3 or 4 cc. of a concentrated solution of sodium bisulphite, to prevent oxidation. The reagent thus prepared will keep for several years in a brown, tightly stoppered bottle. If a pinch of pepper, which contains ground olive stones, be heated gently with a little of the above reagent in a test-tube, the stone cells of the adulterant will be colored a bright red brown, and the colored particles will be seen to settle to the bottom of the tube, after shaking, SPICES. 437 more quickly than the rest of the powder. Or, if the whole is poured ■ from the test-tube into a porcelain dish, the color is more marked. Pure pepper is not colored under this treatment with the reagent. Jumeau uses for a color reagent 5 grams of iodine in 100 cc. of a mix- ture of equal parts of ether and alcohol. Enough of the finely ground pepper to be examined is placed in a porcelain capsule to cover the bottom of the dish, and sufiicient iodine reagent is added to wet the entire mass, carefully avoiding excess. The thick paste is first mixed till homo- geneous, and then allowed to dry in the air, after which it is broken up by a pestle, and the powder examined, either under the microscope, or by the naked eye. With pure pepper, a more or less deep-brown color is produced uniformly through the powder, but if olive stones are present, particles of these are colored yellow. With the naked eye as small an admixture as 2% of olive stones can thus be detected. A solution of anilin acetate colors olive stones yellowish brown, while pure pepper appears grayish, or white. Under the microscope olive stones are readily apparent, since the stone cells differ in size, form, and mode of grouping from those of pepper. Fig. 263, PI. XXXVI, is a photograph of a water-mounted specimen of olive stones. They are for the most part entirely devoid of color, being long and narrow. In shape and manner of grouping they much resemble cocoanut shells (p. 419), but are distinguished from the latter from their lack of color. Fig. 261 shows under low magnification a sample of pepper, bought on the market in Massachusetts, highly adulterated with olive stones. A large mass of the stone cells of the adulterant appears in the center of the field. Many of the stone cells are shown arranged end to end, so that what at first sight appear to be single, very long cells are in reality made up of several shorter ones. In ground olive stones one frequently finds, besides the stone cells, bits of the outer tegument of the seed, show- ing large cells with sinuous, rather thick walls; also bits of parenchyma, crossed frequently by fibro-vascular duct bundles. Buckwheat Products. — Both the hulls and the middlings have been added to black pepper, and the middlings to white pepper. The starch of buckwheat possesses the added advantage, from the point of view of the spice-grinder, that it somewhat resembles pepper starch in micro- scopical appearance, not only in the shape of the starch granules, but also in the manner of grouping into masses. Compare Figs. 128 and 129, Plates II and III, showing buckwheat starch, with Figs. 255 and 256, PI. XXXIV, respectively, showing pepper starch made under similar 438 FOOD INSPECTION AND ANALYSIS. conditions of magnification, etc. The starch granules and masses are coarser in the case of buckwheat than of pepper. Fig. 260, PI. XXXV, shows a photograph of a pepper sample adulterated with buckwheat, masses of both starches appearing in the same field. Other Adulterants found in Massachusetts samples of pepper have been wheat and corn products, nutshells, cayenne, charcoal, turmeric, rice, sand, and sawdust. Charred cocoanut shells were at one time extensively used (see pp. 419 and 420). Long Pepper, according to English analysts, has been used to a con- siderable extent as an adulterant. This is the fruit of the Chavica Rox- burghii, a wild plant growing in India on the banks of rivers. The fruit, as its name implies, is long and cylindrical, while of about the same diam- eter as the spherical true peppercorns. Long pepper contains, as a rule, less than half the amount of piperin that true pepper does, and rather more starch than black pepper. Its taste is much less pungent than that of true pepper. From its method of growth, long pepper is found with considerable dirt and sand adhering to the outer surface of the dried grains. This is due to the fact that the fruit often trails on the ground, and in gather- ing it the natives are not particular about removing the adhering soil. The surface of the fruit grains being very rough and irregular, much of the dirt remains dried thereon. The presence of long pepper thus materially increases the ash. Long pepper possesses a very disagreeable, but pecuHar odor, devel- oped more especially when slightly warmed. For this reason, if for no other, it is not an ideal adulterant, since pepper containing it would not be palatable with warm food. At the present time it costs more than black pepper, and is used chiefly in mixed whole spices for pickles. Brown gives the following analyses of samples of long pepper: Total Ash. Sand and Ash Insol- uble in Hydrochlo- ric Acid. Starch and Matters Converti- ble into Sugar. Albumin- ous Matter Soluble in Alkali. Cellulose. Alcoholic Extract. Ether Extract. Total Nitrogen. 8.91 8.98 9.61 I.I 1-5 44.04 49-34 44.61 15-47 17.42 15-51 15-7 10-5 10-37 7-7 7-6 10-5 5-5 4.9 8.6 2-3 According to Brown and Heisch, the granules of long pepper starch under the microscope are larger than those of true pepper, and more angular. Stokes,* however, finds no such marked difference in the size * Analyst, XIII, p. 109. SPICES. 439 of starch granules and his experience is shared by the writer. When the two specimens (long and true pepper) are viewed side by side in water mounts under the microscope, the average size of the long pepper- starch grains is a trifle larger than those of true pepper, though, unless compared directly, the difference is not readily apparent. Stokes sug- gests a method of distinguishing the two by polarized light. With crossed Nicols, so that a dark field is given, and with the specimen mounted in glycerin, true pepper starch shows an evenly dark appearance, using a low power, while with long pepper a "ghostly white" image is shown. Long pepper, when present in true pepper powder, may generally be rendered apparent by the development of the characteristic odor on heating. Bits of fluffy fiber from the catkin of the long pepper will always be found in the ground powder, and will be apparent under the magnifying-glass. Microscopic examination of the crude fiber discloses the highly char- acteristic, large, beaded cells of the endocarp, also elements of the spindle. RED PEPPER. Nature and Composition.— x\ccording to the U. S. Standards red pepper is the red, dried, ripe fruit of any species of Capsicum, a genus of the nightshade family (SolanacecB), indigenous to the American tropics, but now cultivated in nearly all warm and temperate countries, and is of two distinct kinds: cayenne pepper or cayenne, the dried ripe fruit of C. frutescens, C. haccatum, or some other small fruited species of Capsicum, .and paprika, the dried ripe fruit of C. annuum, or some other large-fruited species of the genus, excluding seeds and stems. Cayenne is characterized by its extreme pungency and the small size of the pods, which seldom exceed 2 cm. in length. The leading commercial varieties are Zanzibar and Japan, the latter being the more brilliant in color. '^Capsicums" or "Bombay Chillies" are low grade peppers of a brown color, with pods 2 to 3 cm. long, which now are said to come from the vicinity of the river Niger in Africa. Paprika is a variety of C. annuum grown in Hungary. The powder is of a deep red color and has a sweetish, mildly pungent flavor. Pimiento is a large-fruited pepper grown in Spain. The succulent pericarp is much used for stuffing olives while the dried pod is ground as a spice, often being substituted for the more valuable Hungarian varieties. The kitchen garden peppers, of which over thirty varieties are cultivated in the United States, also belong to the species C. annuum. The capsicum plant has solitary flowers, with a five-cleft corolla, and the fruit is of an elongated, conical form. The surface of the fresh fruit 44© FOOD INSPECTION AND ANALYSIS. is smooth and very red, but it loses some of its brilliance in drying, and becomes shriveled. The pericarp is thin and tough, and at its base is a five-lobed calyx, greenish brown in color, terminating in a thick stem. The fruit proper is divided into two or three cells, which are separate and distinct at the lower portion, but which unite and form one at the top. The cells inclose a large number of yellow, wrinkled, kidney- shaped seeds, containing a fleshy endosperm, and a curved embryo. Red pepper contains a fixed, bland oil, found in both pod and seed, but more abundantly in the latter, considerable resinous and mucilaginous material, a red coloring matter confined to the pod, and the active principle capsicin, a crystalhne alkaloid, to which much of the pungency is due. The capsicin is present in both seeds and pod, but is more abundant in the latter, where it is dissolved in the oil. Capsicin may be isolated, according to Thresh, by extracting pow- dered cayenne with petroleum ether, mixing the red residue left on evaporating off the solvent with two or three times its weight of oil of almonds, and exhausting the mixture with alcohol. On evaporating the alcohol extract, the capsicin crystaUizes out in narrow, thin plates, very soluble in alcohol, but insoluble in water. They volatiHze at ioo°, and condense in small drops. The red coloring matter is soluble in ether, petroleum ether, carbon bisulphide, and chloroform, but sparingly soluble in alcohol. Analyses of Cayenne.— Richardson * gives the following data of analyses of two pure samples of cayenne: < 6 0) S •s.s 3 V bo s A..... B 2-35 5-74 9.06 5-24 0.12 1-58 26.99 17.90 16.88 18.10 13-13 11.20 41.47 40.24 100 100 2.10 1.70 Maximum and minimum data of ash and non-volatile ether extract of fourteen samples of cayenne, sold in sealed packages in Connecticut, end analyzed by Winton and Mitchell are as follows rf Ash. Maximum. Minimum . .88 Non-volatile Ether Extract. 19.14 15-59 * U. S. Dept. of Agric, Div. of Chem., Bui. I An. Rep. Conn. Exp. Sta., 1898, p. 175. 13, p. 211. SPICES. 441 Winton, Ogden, and Mitchell * analyzed eight samples of whole chillies, representing three varieties, namely Zanzibar, Japan, and Bombay, the summarized results being as follows: Moisture. Ash. Ether Extract. Total Soluble in Water. Insoluble in HCl. Volatile. Non-vola- tile. Maximum ......... 7.08 3-67 5-73 5-96 5.08 5-43 4-93 3-98 0.23 0.05 0-15 2.57 0-73 I-3S 21.81 Minimum ......... 17.17 Average 20.15 Alcohol Extract. Reducing Matters as Starch, Acid Con- version. Starch by Diastase Method. Crude Fiber. Nitrogen, X6.25. Total Nitrogen. Maximum ......... 27.61 21.52 24.35 9-31 7-15 8-47 1.46 0.80 1. 01 24.91 20.35 22.35 14-63 13-31 13-67 2-34 2.13 2.18 Minimum ......... The percentages of " starch by the diastase method " given in the above table represent errors of the process as neither cayenne or paprika contain an appreciable amount of starch. Analyses of Paprika and Pimiento. — Doolittle and Ogden f have made exhaustive analyses of known samples of Hungarian and Spanish red pepper, including determinations of non-volatile ether extract, and iodine number of this extract, which are of especial value in detecting added oil. A summary of their results is given on page 442. Microscopical Structure of Red Pepper. — Fig. 86, from Moeller, shows the appearance under the microscope of various elements of powdered pjiprika. (i) is a sectional view through the outer portion of the fruit shell or pod, showing the epidermis a, and beneath this the coUenchyma layer. The inner epidermis is shown at (2), with its cells thick-walled in places, and inclosing brilliant, red oil drops of coloring matter. (3) represents the outer, and (4) and (5) the inner epidermis in surface view. The outer epidermis of cayenne, which is the element of chief value in distinguishing this from paprika, is shown at (6). A cross-section through the seed shell is shown at (7), a being the epidermis of the seed, b the parenchyma layer directly beneath, and c the tissues of the endosperm. (8) shows in surface view the peculiar seed * Am. Rep. Conn. Exp. Sta., 1898, pp. 200-201. t Jour. Am. Chem. See, 30, 190S, p. 1481. 442 FOOD INSPECTION AND ANALYSIS. 1 Tf \0 r-» N »y r^ rONO ■+ \r OnnO NO vo N t^NO 1 'S- ^ 00 NO t>. rOU^f^ONOG t-HLOOf^^^ CJN 00 10 •SS-9X 'U33oJii>i M M VONO •* M »H M >/- lOMNOThHCO wnOOONO"'! t-lMMMHM NmMMW 10 M 10 M r^ , M r^ t-» r-~ mnOGOnOG "ON'tMOO '+ t^ 0. 00 " ro ro r<~ f^ nOnoiomoOO Mp^t^GT^ t-~ Tf On •jaqiil 3pnj3 "~ ty-) 10 u- ir rONOONVOTj-io 0«^00'd-0 M rt- On t-t M M M M ■^ C^Mi-ii-il-tw Wmi-iNhh >o •* (Nl N nnoGnOnOnO nOnO00"M Ci •qojB^s SB Tj- lO Tf 10 l/- 10 I/^MOnOnOnOn MC^nOmM >-l , •U0ISJ3AU03 ppv M On ^ ^ NO M-f»roONONO\ oOt^r^NONO NO o Aq sja^Bp^ Supnps-g M M :j JO Ofyj auipoj W M l-t M HH M H " ! " OOnOnOn OnmoOnooON ■>*nOi-iOOnO 3 °S. 1 Pi ■*-• On Tt rorororo NOOOt^'^NO rONOf'iOOO-'* 0- On i^ •8IrtB10A-U0Jy[ H t^ On NO'^lOTj-Ttrj- (NI^GOnOO On m 1 P t-( M H M ^ '^ W < tn r^ Lo 00 00 on 0-+00m\o 0>'^0 «jono M 00 On •aniBioA M M 00 M " M m'^oOtJ-ioOn o^ON^/^c^lOON ■*?« 1 < W M M M M wOOmOO mOh"m M >— ( < **-» «^ ■* Oior0 GQi'^GO t^ r^ C^ ^ •I^iox M 00." nOOnOnO>nO-* OO'^OO'tONM M w <; CO NO r^ r^ -0 r- OOiONOOOt^OO NOrO't^rOTj- Tt-'rJ- | Ph M M Ni^OnO^^io oo'^OiJ^i-i On"^i^m'*nO -+NO IDH N C HOC c; 000«0m OOGi-hC c: ^ tN l-L| ui ajqniosui 000 OOOGOO 00000 G Q w OOI^WOnOnOn O^^'^OOOfNj W(Nir;ir)rot^ NOON 1 Oi U3 ■M%VJ^ NO NO M t^ LO M HOO'^NOt^PI t^t^OOfON ro ro w < UI aiqnios lO-^iOlO'^in nOtJ-ionoiono roMNTj-r, ro 00 <0 M VJ 1 NO rOOO On •* 0 NOtONOt^NOt^ ^fOfO^y^rO^ MIO Uh M M On NO •* 00 00 ro ^OlO^^lONO0^ noOOOOOn'* vnro I (-1 ■3 ^ooi IB ssoq rO C) VO 10 M ^ OO^rOrONNO ■^OOO'OM t^ 10 r^ On t^ 00 00 OC 00 OONOONOt^ noi^vIOno^ovo no-^ 1 a fn m O U5 in 6 W u (/■) tn >^ ■n < < 1 E Ms i £ -a .5 ^1 E < ds, place ian: Ma: Min Ave : Maxim Minim Ave rag Placent ian: Ma: Min Ave : Maxim 0. (u bC ^ > c <; b ji aj >2 jS -Ob -^ b -^ a! !A c a, ds (S Hung Spani eds a Hung Spani «i 5 tfl ^ P-( c^ C^ 1 SFICES. 443 epidermis, the appearance of which Moeller compares with that of intestines. At (9) is shown one of the isolated cells of this epidermis more highly magnified, while (10) shows the epidermis of the calyx. Figs. 211 and 212, PI. XXIII, show photomicrographs of powdered cayenne. In Fig. 211 is shown a large bit of the outer epidermis of the fruit pod, while in Fig. 212 appears a smaller portion of this same kind of epidermis, and next to this the characteristic skin of the seed shell, with its striking markings suggestive of the convolutions of the intestines. Yellow or yellowish-red droplets of oily coloring matter are distributed through the field. Starch grains are absent. Fig. 86. — Powdered Red Pepper under tht Microscope. X125. (After Moeller.) Adulteration of Red Pepper. — The U. S. standards for cayenne are the following: Non-volatile ether extract should be not less than 15%; total ash should not exceed 6.5%; ash insoluble in hydrochloric acid should not exceed 0.5%; starch by the diastase method should not exceed 1.5%, and crude fiber should not exceed 28%. 444 FOOD INSPECTION AND ANALYSIS. The most common adulterants ot cayenne are the starches of the cereal grains, corn and wheat. Ground pilot bread and crackers are especially common. Besides these the writer has found in the routine examination of cayenne samples in Massachusetts, ginger, nutshells, turmeric, rice, gypsum, buckwheat, ohve stones, mustard hulls, ground redwood, red ocher, and coal-tar dyes. Fig. 213, PI. XXIV, shows a sample adulterated with wheat, corn, and cocoanut shells. Mineral Adulterants, such as gypsum, and red ocher and other pigments, are all to be looked for. in the ash by methods of qualitative analysis. An abnormally high ash is suggestive of adulteration. According to Vedrodi, the ash of genuine cayenne should not exceed 5.96. The presence of red ocher is rendered apparent by the high content of iron. Salts of lead and mercury are rarely if ever now used for color. Ground Redwood. — Numerous varieties of redwood are commonly used to intensify the color of cayenne, especially when otherwise highly adulterated with colorless materials, such as the starches. The redvv^ood is sometimes used alone, and sometimes in mixture with turmeric. Both redwood and turmeric are readily recognized under the microscope. Fig. 214, PI. XXIV, shows a cayenne sample adulterated with corn starch and red sandalwood, a mass of the latter filhng the center of the field. The wood fibers of the dyestuff, even when finely ground, are very striking under the microscope, showing a brick-red color. Detection of Coal-tar and Vegetable Colors. — Oil-soluble coal-tar and vegetable colors may be tested for in cayenne and paprika by an adaptation of Martin's butter-color method, shaking the ether extract of the sample with the alcohol and carbon bisulphide mixture, page 535. The carbon bisulphide dissolves the oil and natural color, while the over- lying alcohol layer holds in solution many of the artificial coloring matters that may be employed. The natural colors of cayenne and paprika are sparingly soluble in alcohol, but readily soluble in carbon bisulphide. The separated alcohol is examined for colors by methods given elsewhere. Tests for coal-tar dyes should also be made by Sostegni and Carpen- tieri's, or Arata's method (p. 796). Szigeti * treats the suspected sample with water acidified with acetic acid, and boils in this solution a bit of wool, which, if carotin or a coal-tar dye be present, is colored red. If the color is carotin, it will be removed * Zeits. landw. Versuchs. Oesterreich, 5, 1902, pp. 1208, 1222, SP/CES. 445 from the wool by treatment with petroleum ether, or by heating at 100° C. for some hours, but if a coal-tar dye, it will still remain fixed thereon. Detection of Olive Oil in Red Pepper. — The color of paprika and pimiento is often intensified by grinding with olive oil. This form of adulteration is detected by determination of the iodine number of the non- volatile ether extract. The following method elaborated by Seeker has been adopted by the A. O. A. C. : Dry 5 grams on a watch-glass over sulphuric acid for at least twelve hours. Measure 250 cc. of anhydrous alcohol-free ether (p. 66) into a graduated flask with the mark near the lower end of the neck, and brush the paprika into it. Place a mark on the neck of the flask at the meniscus, and allow to stand for one hour, shaking at twenty-minute intervals during that time. Bring the meniscus back to the mark either by cooling if the level has risen, or by adding absolute ether if it has fallen, and let settle. Pipette off 100 cc. of the supernatant liquid, filter through an ii-cm. close-textured paper into a tared, air-dry glass-stoppered 250-cc. Erlenmeyer flask previously counterpoised against a similar flask, wash with a little absolute ether, and distil off the solvent until the ether ceases to come over. Lay the flask on its side in a water-oven, heat for thirty minutes, cool the open flask for at least thirty minutes in the air and weigh. Repeat this heating and weighing until the weight is constant to within one milligram, two heatings usually being sufficient, and calcu- late the per cent of ether extract. If more than i^ hours' heating is required to obtain constant weight or if the ether extract becomes colorless it should be rejected, and a new determination started with freshly purified ether. Dissolve the ether extract in the flask in 10 cc. of chloroform, add 30 cc. of Hanus solution, and proceed as described on page 491. The iodine number thus determined should not be less than 125. GINGER. Nature and Composition. — Ginger as a spice is the ground root- stock of the Zingiber officinale, an annual herb of the family Zingi- heracecp, growing to a height of from 3 to 4 feet. It is a native of India and China, but is cultivated quite extensively in tropical America, Africa, and Australia. The root is dug when the plant is a year old, and when the stem has 446 FOOD INSPECTION /iND ANALYSIS withered. If the root, when freshly dug and scalded to prevent sprout- ing, is dried at once, it forms the so-called black ginger, of which Calcutta and African are the common varieties. When decorticated, the product is known in commerce as white ginger, the chief varieties being Jamaica, Cochin, and Japan. The best variety is Jamaica ginger. The scraped root is sometimes bleached to make it still whiter, or sprinkled with carbonate of lime. In commerce whole or black ginger appears in " hands " 4 to 10 cm. long, and from 10 to 15 mm. in diameter. These usually have three or four various-sized, irregular branches, some short and thick, others elongated. The epidermis is gray or yellowish gray in color, more or less wrinkled, and beneath it is a reddish-brown layer. The inner portion of the dried root is white or yellowish. The root is hard, and of a com- pact, horny structure. White or decorticated ginger appears in " hands " of smaller diameter than the black, and yields a lighter colored powder on grinding. Preserved ginger root is prepared by boiling the root in water, and curing with sugar or honey. Much of the preserved ginger comes from Canton. The distinguishing features of ginger are its large content of starch, its volatile oil, and its resinous matter. Inasmuch as the epidermis con- tains a large amount of pungent resin, it is easy to see how the peeled or decorticated variety is inferior. Oil of ginger is very aromatic, and of a greenish- yellow color. Its specific gravity ranges from 0.875 to 0.885. I^ is slightly soluble in alco- hol. Of its composition little is known. Richardson's analyses in full of five samples of whole ginger-root are as follows: 55 >< S .2£ CJ Calcutta Cochin Unbleached Jamaica Bleached Jamaica, London. . " " American 9.60 9.41 10.49 11.00 10. II 7.02 3-39 3-44 4-54 5-58 2.27 1.84 2.03 1.89 2-54 4-58 4.07 2.29 3-04 2.69 -34 •33 -58 -34 .67 7-45 2.05 4-74 1.70 7-65 6.3c 7.00 10, 9.28 9- 13-44 18.91 15-58 19.21 11.66 1. 01 1. 12 1.74 1.48 1.46 Summaries of Winton, Ogden, and Mitchell's analyses of eighteen samples of whole ginger, representing the common white and black varieties, as well as of two samples of exhausted ginger, are as follows : SPICES. 447 3 'c Ash. u Ether Extract. 13 Soluble in Water. a! '0 > Ji "o > ci 12 "^ Ginger: Maximum 11.72 8.71 10.44 10.61 8.02 9-35 3.61 5-27 2.12 5-05 4.09 1-73 2.71 0-S9 3-55 2.29 0.02 0.44 0.18 1-50 3-53 0.20 0.80 3-09 0.96 1-97 1. 61 0.13 5-42 2.82 Minimum Average 4.10 3-86 0-54 Exhausted ginger from English ginger- Exhausted ginger from extract works . . C 1-.0 ^ rJ 'SB °'a 5q§ U" 2 X o« £^ Ginger: Maximum Minimum Average Exhausted ginger from English gin- ger-ale works. Exhausted ginger from extract works. 6.58 5. 18 4.88 1-52 62.42 53-43 57-45 59.86 60. 31 49 05 54-53 54-57 5-50 2-37 3-91 5-17 9-75 4.81 7-74 6.94 17-55 10.92 13-42 6.15 16.42 •55 ■77 ■23 McGill * records the analyses of ninety-eight samples of ground ginger as sold in the Canadian market. Of thirty-two of these, pronounced pure on analyses, the following is a summar}^: Moisture or Loss on Dry- ing at 100°. Petro- leum- ether Extract. Cold- water Extract. Ash. Total. Soluble. Insoluble. Alkalin- ity of Soluble Ash as KoO. Maximum 12.00 6.13 Q. CO 5 _ 78 15.48 14.04 7.84 3-67 3-15 3-99 2.28 1.96 ■^33 .103 Minimum According to Vogl, the proportion of ginger ash varies quite widely according to the kind, but should never exceed 8%. Exhausted Ginger and Methods of Detection. — There are two kinds of exhausted ginger commercially available for admixture with ground spice, as an adulterant. One is the product left after extraction with strong alcohol in the making of extract of Jamaica ginger, and the other the residue from extraction with either very dilute alcohol, or with water, * Dept. Inl. Rev. Canada Bui. 48, pp. 10, 11. 44 S FOOD INSPECTION AND ANALYSIS. in the manufacture of ginger ale. Ground, exhausted ginger is rarely substituted wholly for the pure variety^ since, from its lack of pungency, the sophistication would be too apparent. It is rather used to mix with the latter in varying proportions, and as an adulterant of other spices. Ginger that has been exhausted by extraction with alcohol has been deprived of most of its volatile oil, which is fovmd in the "extract," while for the manufacture of ginger ale, a water extract, or at most a very dilute alcoholic extract is best adapted. Such a water extract does, as a matter of fact, remove much of the valued pungency, so that the residue, or exhausted ginger, is rather inert. Either the alcohol- or the water-extracted variety of exhausted ginger, when present in considerable amount, would be apparent, one by the alcohol and ether extract, and the other by the abnormally low cold- water extract, and water-soluble ash. Dyer and Gllbard * first called attention to the water-soluble ash as a reliable means of indicating exhausted ginger. Six samples of ginger of known purity were analyzed by them, their results being summarized as follows: Total Ash, Water- soluble Ash. 4-1 3- 3-1 3-8 1-9 2-7 2-3 0-5 I.I 0.2 1.8 0-35 Alcohol Extract, after Ether Extract. Pure ginger (6 samples) : Exhausted ginger (6 samples) Highest Lowest. Average Highest Lowest. Average 3-8 1-5 0.8 Allen and Moor f pointed out the value of the cold-water extract as a help in detecting exhausted ginger, especially when taken in con- nection with the soluble ash, showing that the presence of this adulterant is assured, when the soluble ash is as low as i%, and the cold-water extract is less than 8%. Determination of Cold-water Extract. — Winton, Ogden, and Mitcheirs Method.% — Four grams of the ground sample are placed in a 200-cc. graduated flask, and the latter is filled to the mark with water, and shaken at half-hour intervals during eight hours, after which it is allowed to * Analyst, XVHI (1893), p. 197. t Analyst, XIX (1894), p. 194. I U. S. Dept. of Agric.,, Bur. of Chem., Bill. 65, p. 59; Bui. 107 (rev.), p. 164. SPICES. 449 stand at rest for sixteen hours in addition. The contents are then filtered, and 50 cc. of the fihrate evaporated to dryness in a platinum dish. It is then dried at 100° to constant weight and weighed. Microscopical Structure of Ground Ginger. — Fig. 87, from Moeller, shows elements of ginger root, from which the epidermis has not been Fig. 87. — ^Powdered Ginger under the Microscope. X125. (After Moeller.) removed. A bit of the large-celled cork (or dead protective tissue of the epidermis) is shown in surface view at (i); at (2) is shown in cross- section the parenchyma in which the starch is contained, h being an oil- cell; (3) shows the parenchyma in longitudinal section, with bast fibers. Fragments of spiral ducts are shown at (4), and starch grains at (5). (6) is a cross-section in the extreme interior of the root. The most prominent feature of powdered ginger is the starch grains (5), which Moeller compares in shape to tied sacks. Fig. 228, PL XXVII, is a photomicrograph of pure, ground ginger, mounted in water, showing the starch grains, inclosed in the cells of the parenchyma. Fig. 231 shows the starch grains alone. The granules of ginger starch are ellipsoidal, and as a rule very clear and transparent, being for the most part entirely devoid of either hilum or concentric rings. 450 FOOD INSPECTION AND ANALYSIS. Occasionally granules are to be found, however, with faint concentric markings, and even with an apparent hilum. The characteristic form of the ginger starch granule is more or less egg-shaped, with a small protu- berance near one end. This protuberance serves to readily distinguish the starch granules of ginger from those of wheat, with which ginger is frequently adulterated. While wheat granules are of various sizes, the grains of ginger starch are as a rule much more uniform. Adulteration of Ginger.— U. S. standard ginger should meet the follow- ing requirements : Starch by the diastase method should not be less than 42%; crude fiber should not exceed 8%; total ash should not exceed 8%f lime should not exceed 1%; ash insoluble in hydrochloric acid should not exceed 3%. Besides exhausted ginger, the most common adulterants found in powdered ginger are turmeric, wheat, corn, rice, and sawdust. Sawdust of soft wood is a not uncommon adulterant, and care should be taken to distinguish between the wood fiber natural to the ginger root, and that of the foreign variety. A careful study should be made of finely ground, soft-wood sawdust, with its long spindle ceUs and lateral pores, as shown in Fig. 266, PI. XXXVII, and the wood fiber of the genuine ginger root. A large admixture of sawdust would materially increase the percentage of crude fiber. Fig. 234, PI. XXIX, shows a sample of ginger adulterated with com and wheat. Fig. 232 shows a mass of wheat bran in an adulterated sample. Fig. 233 shows ginger adulterated with turmeric* TURMERIC. Nature and Composition. — Turmeric, while largely used as an adul- terant of other spices (especially of ginger and mustard), possesses some value as a condiment in itself, forming, for instance, the chief ingredient of curry powder.f Turmeric {Curcuma longa) belongs to the same family {Zin giber acea) as ginger, having a perennial rootstock, and an annual stem. It is a native of the East Indies and Cochin- China. Its chief ingredients are starch, a volatile oil, a yellow coloring matter (cur- cumin), cellulose, and gum. * This photomicrograph is very disappointing, in that it fails to show the intense yellow of the central mass of turmeric. ■j" Curry powder consists of a mixture of turmeric, cayenne, and various pimgent spices. SPICES. 451 Curcumin (C^Hj^OJ is insoluble in cold water, but readily soluble in alcohol. It is extracted from powdered turmeric by boiling the latter with water, filtering, and extracting the residue with boiling alcohol. The alcoholic solution is filtered, evaporated, and the residue extracted with ether. The ether extract contains the curcumin, together with a small amount of volatile oil. Curcuma oil is an orange-yellow, slightly fluorescent liquid, its specific gravity being 0.942. The following analyses of turmeric were made in the writer's labo- ratory : Variety. Mois- ture. Total Ash. Ash Soluble inWater. Ash Insoluble in HCl. Total Nitrogen, Protein, NX6.2S. Total Ether Extract. China. . Pubna. . Allcppi. Average 9-03 9.08 8.07 8-73 6.72 8.52 5-99 7.07 5.20 6.14 4-74 5-36 1-73 0.97 1-56 1.42 10.81 6.06 9-75 10.86 12.01 10.66 II. 17 Variety. China. . Pubna. Alleppi. Average. Volatile Ether Extract. 4-42 3.16 3-19 Non-vol- atile Ether Extract. Alcohol Extract. Crude Fiber. Reducing Matter by Acid Con- version . as Starch. 8.84 7.60 7-51 7.98 1 9.22 7.28 4.37 6.96 4-45 5 -84 S-83 5-37 48.69 50.08 50-44 49-73 Starch by Diastase Method. 40.05 29.56 33-03 34.21 Microscopical Structure of Turmeric. — Moeller's representation of characteristics of powdered turmeric is reproduced in Fig. 88, The epidermis is shown at (i) with one of the numerous, one-celled hairs that grow from it, also the scar left after one of the hairs has been removed ; (2) shows in plan view the cork immediately under the epidermis. The tender-celled parenchyma is shown in cross-section at (3), and in longi- tudinal section at (4). In some of the cells of the parenchyma are found dark-yellow lumps of resin (h), and vascular ducts (g), but by far the most numerous and striking contents of the parenchyma-cells are the bright- yellow masses of "paste balls" (3a) and the starch granules, one of which is shown in (3). See also Plate XIII. The starch grains in the water-mounted powder show under the microscope in masses, usually of a deep-yellow color, unless very finely rubbed out, when they appear for the most part in fragments. 452 FOOD INSPECTION /tND ANyiLYSIS. The whole starch granule appears somewhat in the fonn of a clam- shell, with very distinct markings. When fragments of the starch granules are carefully examined, these distinct markings are so strongly charac- teristic, even in the smallest pieces commonly found in the powdered sample, as to nearly always serve to identify them. See Fig. 171, PL XIII. Turmeric as an Adulterant. — Turmeric is a material especially adapted by its deep-yellow color to intensify mustard and ginger, especially when Fig. 88. — ^Powdered Turmeric under the Microscope. X125. (After Moeller.) these spices are adulterated with the Hghter-colored cereal starches, hence it is very commonly found in these spices, both with and without other adulterants. It is also frequently used in small quantities in adulterated cayenne mace, and various spices, to counteract the colors of other dyestuffs, such as ground redwood, which in itself would sometimes be too intense if used alone. SPICES. 453 Turmeric, when present to any marked extent in a powdered spice, may be detected chemically, by extracting the material with alcohol, pouring off the latter, and soaking in it a piece of filter-paper. Tur- meric, if present, will stain the latter yellow, turning red with alkali, espe- cially apparent after drying. Soak the yellow paper in a solution of borax, acidulated sUghtly with hydrochloric acid. When dry, a rose-red color will indicate turmeric, turning dark olive when dilute alkaU is applied. MUSTARD. Nature and Composition. — Mustard is the seed of the mustard plant, an annual belonging to the family CrucljercB, and to the genus Slnapls, or Brassica, as it is sometimes called. The plant is an herb, native throughout Europe, and cultivated extensively in the United States. It grows to a height of from 3 to 6 feet, having yellow flowers and lyrate leaves. Two varieties commonly used are Brassica or {Sinapis) alba, white mustard, and Brassica (or Sinapis) nigra, black mustard, the ground spice being as a rule a mixture of the two. In the trade these varieties are loiown as brovni and yellow mustard respectively. The seeds of both varieties are globular, those of the black mustard being small, and of a dark-brown color on the outside and yellow within. White mustard seeds are considerably larger than the black, being pale yellow in coloi on the outside. The surface of the black nmstard seeds is reticular, and full of small depressions, while the white variety is much smoother. There are several layers forming the husk of the seed of both varieties, and within the husk is the yellowish-colored kernel or embryo, with two cotyledons. Both black and white mustard contain from 31 to 37% of fixed oil, a soluble ferment known as myrosin, and a sulphocyanate of sinapin. Mustard seeds contain no starch, and very little volatile oil as such. Black mustard seed contains sinigrin, or myronate of potash (not found in the white seed), which, when moistened with water, forms by hydrolysis the volatile oil of black mustard, otherwise known as allyi isothiocyanate, in accordance with the following equation: KCioHi^NS^Og-f H,0 = CeHj^Oe -f C3H5CNS + KHSO,. Potassium Glucose Mustard Potassium m.yronate oil bisulphate Mustard Oil (volatile) is a colorless, or shghtly yellow, highly refrac- tive liquid of a very strong odor, and capable of blistering the skin when 454 FOOD INSPECTION AND ANALYSIS. brought in contact with it. It is optically inactive. Its specific gravity varies between 1.016 and 1.030. It boils between 148° and 156°. It turns reddish brown by exposure to light. Volatile oil of black mustard forms thiosinamine with ammonia, as follows : CaHjCNS +NH3= CS.NH2.NH.C3H5. Thiosinamine is soluble in hot water, from which it crystalhzes in tufts of monoclinic crystals, having a melting-point of 74° C. It is pre- cipitated by silver nitrate, mercuric chloride, and Mayer's solution. Wliite mustard differs from the black in containing a sulphur com- pound, slnalhin, C30H42N2S2O15. This is a glucoside. Sinalbin by hy- drolysis forms an oil of white mustard, in a somewhat similar manner to the potassium myronate of black mustard, and according to the follow- ing equation: C3oH,2N2S20i5+ H2O = C,H,ONCS + CeH^^O, + CieH,,NO,HSO,. Sinalbin Sinalbin Glucose Sinapinacid mustard oil sulphate Sinalbin Mustard Oil cannot be obtained by the distillation of white mustard, being sparingly volatile with steam. Sinalbin mustard oil somewhat resembles that., from black mustard, being quite as pungent, but less strong in odor when cold. It is soluble in dilute alkali. Fixed oil of mustard is a bland, tasteless, and nearly odorless oil, its specific gravity at 15° varying between the fimits of 0.914 to 0.918. It is said to be used to some extent as an adulterant of table oils, being separated by pressure from the crushed mustard seeds before the latter are ground into "flour." The chief use of mustard oil is in mixture with other oils as an illuminant. MUSTARD FLOUR. — In the process of preparing the ground spice com- monly known as mustard "flour," the seeds are first crushed and sepa- rated by winnowing from the hulls, the latter being incapable of the fine grinding necessary to produce a smooth flour. The yellow hulls are, however, found in the cheaper grades ot ground mustard, and both varieties of hull are frequently used in the wet mustard preparations, sold in bottled form. In order to produce an even, dry powder, free from lumps, it is necessary to remove a large portion of the fixed oil, which is indeed of no value in the final product, and this is done by subjecting the crushed material to hydraulic pressure, during which process the SPICES. 455 mustard is molded together into thin, hard plates, called "mustard cake." This is then broken up and reduced to fine powder by pounding. Richardson's* analyses of whole-seed flour, prepared by himself without the removal of the fixed oil, are as follows: V cS .c ^ <; 5-57 4.29 3-33 5-23 b.i7 4-99 4-83 5-96 4. II 4.88 3-" 4.07 4.62 5.61 55 c -g «fe s ,^ u "S-Q 3-S X^ t« ^r" .Q.^ pi, en u <; 33-56 .00 5-40 28.88 34-83 .00 9-05 25-56 28.12 .00 9-50 23-44 31-96 .00 8-53 31-13 36.63 .00 16.18 24.69 31-51 .00 6.90 30-25 39-55 .00 10.84 25.88 ^S White seed White flour Seed husk California yellow. California brown, English yellow . . Trieste brown. .. -97 1.84 -55 1.27 1-35 2.06 -63 21-33 20.16 27.23 16.35 12.16 22.10 18.87 4.62 4.09 3-75 4.98 3-95 4-84 4.14 Winton and Mitchell made no full analyses of mustard seed of known purity, but the following is a summary of analyses of 18 samples of com- mercial mustards, sold in packages in Connecticut, and not found to be adulterated: Total Ash. Ether Extract. Reducing Matters by Acid Con ver- sion, as Starch. Starch Diastase Method. Crude Fiber. Volatile. Non-vol- atile. X6.2S. Maximum ............ 7-35 4.81 5-99 1.90 0.00 0.56 28.10 17.14 20.61 6.12 1.85 4-33 2.08 0.28 1.07 4.87 1.58 2.58 43-56 35-63 39-57 Minimum ............ Average .............. The following analyses of 5 samples of mustard flour, 6 samples of mustard hulls, and 6 samples of whole mustard, were made in the author's laboratory in 1903: * U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 2. 456 FOOD INSPECTION AND ANALYSIS. vo r^ o O f^ OO o O r^ O>00 i^ ^ O O iH 00 f^ (^ o ■u- Ttcc. o* ^ O Ov ^ •* O r-00 ^ 00 ".so t-- O- r^oo ^ ^ f^^O '^ ^00 o ) t •* o> o o < •Hsv Flox •U83 -xa (ou.ooiv •asB^sBTQ Aq r^sO r^ r^ i^isO ^O OO 0> O' o* o- o* o* ) O O ►- O '-O0 . w r- >A o fooo ro i^ -^00 O O O- O i\0 o- o- o> o o HI CO « vO Tf ro I •UOTS -jaAU03 PPV '^'^ sas^l^lBj^i auptipa-jj CC 00 vO ■* >- I^ O o ^00 o O o "^ ^ t^o r^ o o 00 o> o 00 c "2 Ji2 CU CO .-J '-' .,-( ^ — M ■'- '3 ^ -o M or- .* 4 cA ■*■<*• -ooo m 1^ CN o* r^ OO o. ^ [^ o •^oBJ^xa ^oqoo^v ) 00 I^ « 00 O -*^'J-M 00000 o 1 Tt ro t^ TfO O O -xg jama sn^^PA OO f^vO - CO ^O n-o r^ O r^oo 00 O O O O O O O O O O O O O O OOOOOOOO OOOOOOOO O O O O O O O O O O O O a 0! ^ E ^ -xg jaq^a F^ox O O r~ " 0> 00 fOO 1-00 4^1- Spath, E. Ncue Verfalschungen von Gewiirzen. Forsch. iiber Lebensm., 3, 1896, p. 308. 470 FOOD INSPECTION AND ANALYSIS. Spath, E. Zur mikroskop. Priifung des Piments. Forsch. iiber Lebensm., 2, 1895, p. 419. Zur Priifung und Beurteilung des gemahlenen schwarzen Pfeffers. Zeits. Unters. Nahr. Genuss., 9, 1905, p. 576. Vorschlage des Ausschusses zur Abanderung des Abschnittes " Gewiirze" der "Vereinbarungen." Zeits. Unters. Nahr. Genuss., 10, 1905, p. 16; 12, 1906, p. 12. Der Nachweis von Zucker in Macis und in Zimt. Zeits. Unters. Nahr. Genuss., II, 1906, p. 447. Sprinkmeyer, H., u. Furstenberg, a. Beitrage zur Kenntnis der Gewiirze. Zeits. Unters. Nahr. Genuss., 12, 1906, p. 652. VOGL, A., and Hanausek, T. F. Untersuchung der- Gewiirze. Sudd. Apoth. Ztg., 1896. Waage, T. Banda und Bombay Maces. Pharm. Centralbl., 33, 1892, p. 372. Warburg, O. Die Muskatnuss, ihre Geschichte, Botanik, Kultur, u. s. w. Leipzig, 1897. Weigle, T. Untersuchungen iiber die Zusammensetzung des Pfeffers. Ber. Pharm. Ges., 1893, p. 210. WiNDiscH, R. Beitrage zur Kenntnis des Aschengehaltes des Paprika. Zeits. Unters. Nahr. Genuss., 13, 1907, p. 389. WiNTON, A. L. Spices. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 1902. Microscopy of Vegetable Foods. New York, 1906. Conn. Exp. Sta. An. Rep. 1896, et seq. Mass. State Board of Health An. Reports, 1883, et seq. U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 162 CHAPTER XIII. EDIBLE OILS AND FATS. Nature and Properties. — ^The oils and fats are the glycerin salts of glycerides of the fatty acids, the most important, on account of their occurrence in nearly all fats and oils, being the triglycerides of oleic, palmitic, and stearic acids, known as olein, palmitin, and stearin, respectively. Fats and oils are insoluble in water, and are almost insoluble in cold 95% alcohol, though they are somewhat soluble in absolute alcohol. They are readily soluble in ether, petroleum ether, chloroform, amyl alcohol, oil of turpentine, and carbon bisulphide. Following is a list of the fatty acids whose glycerides are found in edible oils and fats, together with their melting- and boiling-points when these have been determined, and the oils and fats in which they occur. ACIDS OF THE ACETIC SERIES C^Hj^Oj.* Name, Formula. Melting- point. Boiling- point. Occurrence in Oils and Fats. Butyricf QH.O^ -6-5° 162.3 Butter, cocoa butter. Caproicf CeHi^Oj 200 Butter, cocoanut oil. Caprvlicf CsHieOj 16.S 236 « <( Caprict CioH2„Oj 3^-3 26S-270 << cc Laurie C12H24O2 43-6 176 Cocoanut oil, cocoa butter. Myristic, CuHggOj 53-8 196.5 " sesame oil. Palmitic CieHaaOj 62.6 215 Nearly all oils and fats. Stearic ClgHggOj ^.3 232-5 Fats and nearly all oils, except olive and com. Arachidic *-' 20^40^2 77 .... Peanut, olive (trace), rape (trace). Behenic ^22^44^2 83-84 .... Rape, mustard. Lignoceric. ,. . C24H48O2 81 Peanut. * Lewkowitsch, Oils, Fats, and Waxes, 3d ed. (1904), PP- 63-71. t These four acids are the only ones that can be distilled under ordinary pressure without becom- ing decomposed. 471 472 fOOD INSPECTION ^ND ANALYSIS. ACIDS OF THE OLEIC SERIES CnH^n-^O,. Name. Formula. Melting- point. Boiling- point. Occurrence in Oils and Fata. Hypogseic Oleic Iso-oleic * . . . . Rapic Erucic C-ieHgoOj C13H34O3 C18H34O2 ^18^3402 CnoH^jOa 33° 14° 44-45° 33-34° 2^6° 232-5° 264° Peanut. Nearly all fats and oils. Rape and mustard. ACIDS OF THE LINOLEIC SERIES CtiH^u-P^. Name. Formula. Melting- point. Boiling- point. Occurrence in Oils and Fats. C18H32O2 Under-i8°C. Olive, cottonseed, peanut, sesame, cocoa butter, poppy seed, sun- flower. * Solid oleic acid. Saponification of Fats and Oils. — By this term is meant the decom- position of the glycerides composing the fats or oils, whereby the tri- atomic alcohol glycerin and the fatty acids are separated. The sapon- ification process is commonly applied in carrying out many determina- tions of value on fats and oils, such as those of the soluble and insoluble fatty acids, the Reichert value, etc. As commonly carried out, the tri- glycerides are first split up into glycerin and the soluble soaps of the fatty acids by the action of caustic alkali, usually in solution in alcohol. This part of the process in the case of a given oil, composed, for example, of stearin, olein, and palmitin, is illustrated as follows: (i) C3H5(CisH3503)3+ 3KOH = C3H5(OH)3+ 3K(C,«H3302) Stearin or Glycerin Potassium triglyceryl stearate stearate (2) C3H,(C,eH3,0,)3+ 3KOH = C3H5(OH)3+ 3K(C,,H3,03) Palmitin or Potassium triglyceryl palmitate palmitate (3) C3H5(QsH3302) + 3KOH = C3H5(OH)3-|-3K(C,3H3303) Olein or tri- Potassium glyceryl oleate oleate These "soaps, " or potassium salts of the fatty acids, are further decom- posed by the action of sulphuric acid into the free fatty acids and jpf/as- sium sulphate, in the case of potassium stearate, as follows: 2K(C,«H3A) + H2SO,=K2SO,+ 2H(Ci3H,50a) Potassium stearate Stearic acid EDIBLE OILS AND FATS. 473 ANALYSIS OF EDIBLE OILS AND FATS. No class of food products presents more difificulties to the analyst than the fats and oils, in that the various physical and chemical constants by which one derives information as to their nature or purity differ within such wide limits that it is not easy to prescribe absolute standards. Many elements enter in to cause this variation, chief among which are, in vegetable oils, the large number of varieties of fruits or seeds from which each oil is in different localities obtained, as well as the vaiious grades of each oil with respect to refining. In the animal fats, butter and lard, the kind of food fed to the animal undoubtedly influences the constants of the fat, and in all fats and oils much depends upon their age, and the conditions under which they are kept as to temperature, exposure to moisture, light and air, etc. Rancidity should not be confounded with acidity, although rancid oils usually are high in acids. Lewkowitsch holds that fatty acids are liberated by the action of moisture in the presence of enzymes. If in addition the oil is exposed to air and light, the fatty acids are acted on causing rancidity, which is detected by taste and smell, although chemically little understood. As a rule rancidity develops more readily in liquid oils in which olein predominates than in solid fats. To avoid changes samples should be kept in a dark, cool place in tight containers. Judgment as to Purity of a given oil or fat should not be hastily given. .It is sometimes comparatively easy to prove the presence and approx- imate amount of an adulterant, the various constants all serving to identify it without fail. Again, in some cases it is easy to pronounce the sample adulterated, without being able to definitely state the exact nature of the adulterant. The tests to be employed depend on the particular case in hand. Sometimes the determination of two or three constants will be sufficiently definite. Again, a large number of tests must be made before one can intel- ligently form an opinion. It should be borne in mind that skilful manu- facturers may adulterate the edible oils and fats with mixtures intended to confuse the chemist, and yield on analysis constants that are entirely misleading. Much information may usually be gained by carefully noting the color, taste, odor, and appearance of the sample. Filtering, Measuring, and Weighing of Fats. — These manipulations naturally present some difficulties in the case of solid fats not encountered with hquid oils. 474 FOOD INSPECTION AND ANALYSIS. A steam- or hot- water-jacketed funnel as represented in Fig. 92 is con- venient for filtering fats, or, in the absence of this contrivance for keeping the fat in a molten condition, a hot funnel may be employed, the filtering being best conducted in a warm closet or oven. Portions of the fat for the various determinations may be measured o£E with a pipette while the fat is still hot, but a much better way is to Fig. 92. — ^Jacketed Funnel for Hot Filtration. cool the fat (over ice if necessary), and to weigh the desired amounts in the soHd state. This can very readily be done by placing a flat platinum or other dish on the scale-pan, covering it with a moderately thick, cut filter-paper somewhat larger in diameter than the dish and designed to lie flat upon it, and taking the tare of both dish and filter. The solidified fat, after mixing with a stirring-rod, is transferred in one or more por- tions to the middle of the filter, and the exact weighed amount is obtained, after which, by carefully handhng the edges of the filter and folding in the latter, the fat with the filter may be transferred to a flask or other receptacle. Specific Gravity. — The specific gravity of liquid oils is most con- veniently taken either at room temperature or at 15.5°, being always EDIBLE OILS AND FATS. 475 best referred to the latter. Either the hydrometer, Westphal balance, Sprengel tube, or pycnometer are employed, according to the degree of accuracy required. If taken at any other temperature than 15.5°, say at room temperature, J", the specific gravity may be computed at 15.5° by the formula G=G'+i5:(r-i5.5)* in which G is the specific gravity at 15.5°, G' the specific gravity at T°, and K a factor varying with the different oils as follows: FACTORS FOR CALCULATING SPECIFIC GRAVITY. Oil. Correction for 1° C. Observer. Cod-liver oil . 000646 .000658 . 000629 .000655 .000620 .000624 .000629 A. H. Allen C. M. Wetherill C. M. Stillwell A. H. Allen « << Lard oil Olive oil Peanut oil Sesame oil. ................ Unless the most accurate work is necessary, it is sufficient to assume In all cases ii' = 0.00064, in which case the formula becomes G = G' + o.ooo64(r-i5.5). In the case of solid fats, it is most convenient to take the specific gravity of the melted fat. This may be done at any temperature above the melting-point by either of the instruments above described, or at the temperature of boiling water by the Westphal balance or pycnometer. When the pycnometer is used, it is immersed in a water-b'ath, the temperature of which is well above the melting-point of the fat, say 35° or 40°. While still immersed nearly to the neck, it is carefully filled with the melted fat and kept in the bath till the fat has acquired the same temperature, usually about fifteen minutes. If the pycnometer is pro- vided with a thermometer stopper, this will serve to indicate the tem- perature; otherwise a separate thermometer is inserted in the bath. The pycnometer is then removed, cleaned, dried, and cooled to the room temperature, at which it is weighed. The factors employed in the above formula for calculation of specific gravity of solid fats at 15.5° are as follows : * Allen, Com. Org. Anal., 4 Ed.; Vol. II, p. 49. 476 FOOD INSPECTION ANr. ANALYSIS. FACTORS FOR CALCULATING SPECIFIC GRAVITY. Fats. Correction for 1° C. Cocoa butter 0.000717 .000675 .000650 .000617 .000674 .000642 .000657 Tallow Lard Butter fat Cocoanut stearin Cocoanut oil Palm nut oil Either the Westphal balance or the hydrometer may be used directly on the melted fat, carefully recording the temperature and calculating as above. For making the determination with the Westphal balance at the tem- perature of boiling water, the melted fat is contained in a vessel immersed in a boiling water-bath, and kept sufficiently long to acquire that tem- perature, which is carefully noted. A. O. A. C. Method.'^ — The pycnometer, being perfectly clean, is first weighed with the stopper, after which it is filled with freshly boiled, hot, distilled water and placed in a bath of boihng water, where it is kept for half an hour, replacing any loss by evaporation in the flask with boihng distilled water. The stopper of the pycnometer, previously heated at 100°, is then inserted, and the flask removed and wiped perfectly dry. It is then allowed to cool nearly to room temperature, and weighed on the balance when the temperature is the same as that of the roam. The flask, being again perfectly clean and dry, is filled while hot with freshly melted and filtered hot fat, free from air-bubbles, and kep^ for half an hour in a boiling water-bath, after which the stopper, previously heated as before to 100°, is inserted, and the flask taken from the bath and wiped dry. It is then allowed to cool and weighed when the tem- perature of the room has been reached. The specific gravity is calculated by dividing the weight of the fat by the weight of the water previously found. Having once obtained the weight of the flask and the weight of a volume of water contained therein when at boiling temperature, these figures can be constantly used without redetermination, if the flask is cleaned thoroughly each time. Calculation of Proportions of Two Known Oils in Mixture.f — This may be roughly accomplished from the specific gravity of the mixture and of the oils known to compose it. * U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 21. t ViUiers et Collin, Las Substances Alimentaircs, p. 646. EDIBLE OILS AND FATS. •477 Let G = specific gravity of mixture, D and Z)' = specific gravity of the two oils, and A' = % oil of specific gravity D. loo(G-D') ThenX = D-D' EDIBLE OILS AND FATS ARRANGED IN ORDER OF SPECIFIC GRAVITY. Cocoa butter Mutton tallow Beef Butter , Lard Poppyseed oil. Sunflower oil , Corn oil Cottonseed oil Sesame oil. . . . Peanut oil. . . . Mustard oil. . . Olive oil Rape oil Specific Gravity. .976 -953 •952 -940 ■938 -927 .926 .926 -925 .924 .921 .920 .918 .917 -950 -937 -943 .926 -934 .924 -924 .921 .922 -923 .917 .916 .916 -913 The Viscosity, or degree of fluidity in the case of edible oils, is of less importance than in the case of lubricating oils, and gives little insight into the nature or purity of the sample. Hence a discussion of various viscosimeters and their use will not be included here, but reference is made to Lewkowitsch * for information regarding them. The Refractive Index, and the reading on the arbitrary scale of the butyro-refractometcr, express in two different and interchangeable terms the refraction value, a useful constant of fats and oils and .easily determined. For the routine examination of fats and oils the butyro-refractometer is more convenient than the Abbe refractometer, and the readings obtained by the former instrument are less cumbersome than refractive indices. These instruments and details with regard to their manipulation are described in Chapter VI. The readings on the scale of the butyro-refractometer may be readily transformed into refractive indexes and vice versa by table or by means of the Leach and Lythgoe slide rule (page 107). Lythgoe'sf table on pp. 478 and 479 is useful as showing readings on the butyro-refractometer of all the edible oils and fats at various temperatures. * Chemical Analysis of Oils and Fats, 3d ed., 1904, pp. 197-209. ■j" Tech. Quarterly, 16, 1903, p. 222. 478 FOOD INSPECTION AND ANALYSIS. CALCULATED READINGS ON BUTYRO-REFRACTOMETER OF EDIBLE OILS AND FATS. Temp. C. Cocoanut OU. Butter.* Beef Stearin. Cacao Butter. B°ef Tallow. Lard Stearin. Beef Oleo. Lard.t Lard Oil. 45 -o 31.6 41-5 41.9 43-7 44-1 44-9 45-0 48.2 44-5 31-9 41.8 42.2 44.0 44-3 45-1 45-3 48.4 44-0 32.2 42.0 42-4 44-2 44-6 45-5 45-6 48-7 43-5 32.4 42.3 42.6 44-5 44-8 45-7 45-9 49.0 43 -o 32-7 42.6 42-9 44-8 45-1 46.0 46.1 49-3 42.5 52-9 42.9 43-2 45-0 45-4 46.3 46-4 49-6 42.0 33-2 43-1 43-5 45-3 45-6 46.5 46-7 49-9 41-5 33-5 43-4 43-7 45-6 45-8 46.8 47-0 50.1 41.0 33-7 43-7 44.0 45-9 46.1 47.0 47-3 50-4 40-5 34-0 43-9 44-2 46.1 46-3 47-3 47-6 50-7 40.0 34-3 44-2 44-5 46.4 46.6 47-6 47-8 51-0 SI. 6 39-5 34-5 44-5 46.6 46. S 47-8 48.1 51-3 51.8 39-0 34-« 44-8 46.8 47-1 48.1 48.4 51.6 52-1 38.5 35-0 45-0 47-1 47-4 48.4 48.7 Si-9 52.4 38.0 35-3 45-3 47-4 ■17-6 48.6 48-9 52-1 52-6 37-5 35-5 45-6 47-6 47-8 48-9 49-2 52-4 52.8 37-0 35-8 45-9 47-9 48-1 49-2 49-5 52-7 53- r 36-5 36.1 46.1 48.2 48-3 49-4 49-8 53-0 53-4 36.0 36-3 46.4 48-5 48.6 49-7 50.0 53-3 53-7 35-5 36.6 46-7 48.7 48.8 50.0 50-3 53-6 54-0 35-0 36-9 47.0 49 -o 49.1 50.2 50.6 53-9 54-2 34-5 37-1 47-2 50-9 54-2 54-5 34-0 37-4 47-5 51-2 54-4 54-7 33-5 37-6 47-8 5^-5 54-7 55-0 Zi-o 37-9 48.1 51-7 55-0 55-3 32 5 38-1 48-3 52-0 55-3 55-6 32.0 38-4 48.6 52-3 55-6 55-9 31-5 S8.6 48-9 1^2.6 55-9 56.1 31.0 38-9 49-2 52-8 56-1 56-4 30-5 39-2 49-5 53-1 56.4 56-7 30.0 39-5 49-8 53-4 56.7 57-0 29-5 39-7 50.0 53-7 57.0 57-2 29.0 40.0 50-3 53-9 57-3 57-5 28.5 40.3 50 -5 54-1 57-6 57-8 28.0 40.5 50.8 54-4 57-8 S8.i 27-5 40.8 51-1 54-7 58.1 58-3 27.0 41.0 51-4 55-0 58-4 S8.6 26.5 41-3 51.6 55-2 58.7 58-9 26.0 41-5 51-9 55-5 59-0 59-2 25-5 41.8 52-2 65.8 59-3 59-5 25.0 42.0 52-5 66.1 59-6 59-8 * Butter readings by Zeiss. fLard readings by Hefelmann. EDIBLE OILS AND FATS. Al<) CALCUI-ATED 'RF.KDINGS— {Continued). Temp. C. Olive OU. Peanut OU. Cotton- seed Oil. Rape- seed Oil. Sesame Oil. Yellow Mustard Oil. Black Mustard Oil. Sun- flower Oil. Com Oil. Poppy- seed Oil. 35-0 57-0 59-8 61.8 62.1 62.3 63.0 64.2 64-5 65.0 ^5-5 34-5 57-2 60.0 62.1 62.4 62.5 63-3 64-5 64.8 65-3 65.8 34 -o 57-4 60.3 62.3 62.7 62.8 63.6 64.8 65.1 65.6 66.1 33-5 57-7 60.6 62.5 63.0 63.1 63-9 65.1 65-4 65-9 66.4 ii-o 58.0 60.9 62.8 63-3 63-4 64.1 65-3 65-7 66.2 66.7 32-5 58-3 61. 1 63.0 63.6 63-7 64.4 65.6 66.0 66.5 67.0 32.0 58-5 61.4 63.2 63.8 64.0 64.7 65-9 66.3 66.8 67-3 31-5 59-0 61.7 63.6 64.1 64-3 65.0 66.2 66.6 67.1 67.6 31.0 59-2 62.0 64.0 64.4 64.6 65-3 66.5 66.9 67-4 67-9 30-5 59-5 62.2 64.2 64.7 64.9 65.6 66.8 67.2 67-7 68.2 30.0 59-9 62.5 64-5 65.0 65.1 65.8 67.0 67-5 68.0 68.5 29-5 60.1 62.8 64.9 65-3' 65.4 66.1 67-3 47-7 68.2 68.7 29.0 6o«3 63.1 65.1 65.6 65-7 66.4 67.6 68.0 68.5 69.0 28.5 60.6 63-3 65-3 65-9 66.0 66.7 67.9 68.3 68.8 69-3 28.0 60.9 63:6 65-7 66.1 66.2 66.9 68.1 68.6 69.1 69.6 27-S 61. 1 63-9 66.0 66.4 66.5 67.2 68.4 68.9 69.4 69-9 27.0 61.5 64.2 66-5 66.7 66.8 67-5 68.7 69.2 69-7 70.2 26.5 62.0 64.4 67.0 67.0 67.1 67.8 69.0 69-5 70.0 70-5 26.0 62.2 64-7 67-3 67-3 67.0 68.0 69.2 69.8 70-3 70.8 25-5 62.4 65-0 67-5 67.6 67.7 68.3 69-5 70.1 70.6 71. 1 25.0 63.0 65-3 67.9 67.8 67.9 68.6 69.8 70.4 70.9 71-4 24-5 63-3 65-5 68.2 68.1 68.2 68.9 70.1 70.7 71.2 71.7 24.0 63-6 6^.8 68."; 68.4 68. c; 69.2 70.4 71.0 71-5 72.0 23-5 63-9 66.1 68.8 68.7 68.8 69-5 70.7 71-3 71.8 72-3 23-0 64.2 66.4 69.1 69.0 69.1 69.7 70.9 71.6 72.1 72.6 22-5 64-5 66.6 69.4 69-3 69.4 70.0 71.2 71.9 72.4 72.9 22.0 64.8 66.9 69.7 69.7 69.7 70-3 71-5 72.2 72.7 73-2 21-5 65-1 67.1 70.0 70.0 70.0 70.6 71.8 72-5 73-0 73-5 21.0 65-4 67.4 70-3 70-3 70-3 70.9 72.1 72.8 73-3 73-8 20.5 65-7 67.7 70.6 70.6 70-5 71.2 72.4 73-1 73-6 74-1 20.0 66.0 68.0 70.9 70.8 70.8 71.4 72.6 73-4 73-9 74-4 19-5 66.3 68.2 71.2 71. 1 71. 1 71.7 72.9 73-6 74-1 74-6 19.0 66.6 68.5 71-5 71.4 71.4 72.0 73-2 73-9 74-4 74-9 18.5 66.9 68.8 71.8 71.7 71.7 72-3 73-5 74-2 74-7 75-2 18.0 67^2 69.1 72.1 72.0 72.0 72.6 73-8 74-5 75-0 75-5 17-5 67-5 69-3 72.4 72.3 72-3 72.9 74-1 74-8 75-3 75-8 17.0 67.8 69.6 72.7 72.6 72-5 73-1 74-3 75-1 75-6 76.1 16.5 68.1 69.9 73-0 72.9 72.8 73-4 74-6 V5-4 75-9 76-4 16.0 68.4 70.2 73-3 73-2 73-1 73-7 74-9 75-7 76.2 76-7 15-5 68.7 70-5 73-6 73-5 73-4 74.0 75-2 76.0 76-5 77.0 15.0 68.9 70.8 73-8 73-8 73-7 74-3 75-5 76-3 76.8 77-3 4So FOOD INSPECTION AND ANALYSIS. Melting-point. — A piece of small glass tubing is drawn out to a ca- pillary open at both ends, and this is inserted into a beaker of the fat, melted at a temperature slightly above its fusing-point. A portion of the melted fat being drawn up into the capillary, the latter is removed and the fat allowed to solidify spontaneously. After an interval of not less than twelve hours, the capillary is attached by a rubber band to the stem of a delicate thermometer (preferably capable of being read to tenths of a degree), the portion of solidified fat being opposite the thermometer bulb. A test-tube containing water is held in the neck of a flask in such a man- ner as to be immersed in water contained in the flask, as shown in Fig. 93, the flask being held on the ring of a stand, with wire gauge inter- posed between flask and flame. The thermometer with attached capil- lary is then held immersed in the water of the test-tube and below the Fig. 93. Fig. 94. Fig. 93, — Apparatus for Determining Melting-point. Capillary tube with enclosed fat shown on the right, enlarged. Fig. 94. — Reichert Flask with Card Inserted for Quick Evaporation. level of the water in the flask, as shown. The water in the flask is then heated very gradually, so that the rise of temperature as shown by the thermometer does not exceed 0.5° C. per minute, the exact temperature at which fusion of the fat occurs being recorded as the melting-point. The flame is then removed, and the temperature at which the fat solidifies is noted as the solidifying-point. EDIBLE OILS /IND FATS. 48 1 The mean of two or three determinations is usually taken as the true melting and soHdifying-points, Reichert-Meissl Process for Volatile Fatty Acids. — This process has undergone various modifications from time to time. Reichert origi- nally. used 2.5 grams of fat, but Meissl, who improved the process, used Fig. 95. — Apparatus for Reichert-Meissl and Polenske Distillation. 5 grams, so that the Reichert-Meissl number is now expressed on the basis of 5 grams of fat. The method is conveniently carried out as follows : Five grams of the fat are transferred to a dry, clean Erlenmeyer flask of about 300 cc. capacity, 10 cc. of 95% alcohol are added, and 2 cc. of sodium hydroxide solution (prepared by dissolving 100 grams of sodium hydroxide in 100 cc. of water). The flask with its contents is then heated 482 FOOD INSPECTION AND ANALYSIS. on a water-bath with a funnel in the neck, which satisfactorily replaces the return-flow condenser originally prescribed. The heating is con- tinued with occasional shaking fill saponification is complete. This stage of the process is indicated by the appearance of the solution, which is then perfectly clear and free from fat globules.. The condenser-funnel being removed, the contents of the flask are next evaporated by continued heating over the bath to dryness. This may be hastened by inserting a card in the neck of the flask, as shown in Fig. 94, thus starting a circulatory movement to the air through the flask. The dry soap thus formed is then dissolved by warming on the water- bath with 135 cc. of added water, shaking the flask occasionally. After cooling, 5 cc. of dilute sulphuric acid (200 parts sulphuric acid in i liter of water) are added, and the fatty acid emulsion formed is melted by heating the flask on the water -bath, the flask being corked during the heating. The fatty acids are completely melted when they form an oily layer on the surface of the solution. Scraps of pumice stone joined by platinum wires are next placed in the flask to prevent bumping, and the flask is properly connected with the condenser for distilHng, as shown in Fig. 95. A flask graduated at no cc. is used as a receiver, the funnel placed therein being provided with a loose tuft of absorbent cotton to serve as a filter. The distilla- tion is conducted by so grading the heat that the receiving flask is filled with the distillate in about thirty minutes. Finally the entire distillate is titrated with decinormal sodium hydrox- ide, using 0.5 cc. of a solution of phenolphthalein as an indicator. The number of cubic centimeters of decinormal alkali required to neutralize the acidity of the distillate from 5 grams of the fat in the manner described expresses what is known as the Reichert-Meissl number. Lefjmann and Beam's Modification.* — Five grams of the fat placed in the flask are treated with 20 cc. of a solution of soda in glycerin (20 cc. of a 50% solution of sodium hydroxide in 180 cc. of glycerin), heating the flask till the contents are completely saponified. The solution becomes perfectly clear, showing complete saponification in about five minutes, after which 135 cc. of water are added to the clear soap solution, at first drop by drop to prevent foaming; 5 cc. of the dilute sulphuric acid are then added, and the distillation conducted at once without first melting the fatty acids. * Leffmann and Beam, Select Methods of Food Analysis, p. 146. EDIBLE OILS /IND FATS. 483 EDIBLE OILS AND FATS IN THE ORDER OF THEIR REICHERT-MEISSL. NUMBER. Butter Cocoanut oiL. Cocoa butter. Corn oil Lard Cottonseed oil Sesame oil. .. Rape oil .... Olive oil Beef tallow. . . Lowest. 24-5 6.65 0.70 0.58 Highest. 32 7-8 o.So .20 .90 Average. 28.25 7-2 0-5 3.16 1. 10 0-95 0-95 0.74 C.60 0-5 Polenske Number.* — This number represents the volatile fatty acids insoluble in water, and is of value in detecting cocoanut oil in butter and other fats. The details of apparatus and manipulation here described should be closely adhered to in order to secure comparable results. Both the Reichert-Meissl and the Polenske number may be determined in one weighed portion of the fat. Place 5 grams of the clear tiltrated fat in a 300-cc. Jena flask, add 20 grams of glycerine and 2 cc. of a 50% solution of sodium hydroxide. Heat the flask on a wire gauze until the contents are completely saponified, which requires about 5 minutes, and is indicated by the clearing up of the liquid. While still hot add 90 cc. of boiled water, at first drop by drop to prevent foaming, and shake until the soap is dissolved. The solution should be completely clear and almost colorless. Rancid or oxidized fats that yield a brown soap solution should not be examined. To the soap solution, warmed to 50°, add 50 cc. of dilute sulphuric acid (25 cc. : i liter) and 0.5 gram of granulated pumice stone with grains I mm. in diameter, then connect with the distilling apparatus shown in Fig. 95. Distil over a 0,5 mm. mesh copper gauze, using a Bunsen flame so regulated as to give a distillate of no cc. in 19-20 minutes, and a stream of water that will cool the distillate to about 20-23°. The room should have a temperature of about 18-22°. As soon as no cc. have come over, replace the flask by a 25-cc. measuring cylinder. Without mixing the distillate place the flask for 10 minutes in water at 15°, so that the no cc. mark is about 3 cm. below the surface of the water. After the first five minutes, gently move the neck of the flask in * Polenske, Zeits. Unters. Nahr. Genuss., 7, 1904, p. 274. Fritsche, ibid., p. 193. 484 FOOD INSPECTION /iND ANALYSIS. the water so that tne fatty acids floating on the surface come in contact with the glass, noting at the end of 10 minutes the condition of these acids. If the butter is pure, the floating acids are either sohd or form a half sohd turbid mass, according as the Reichert-Meissl number is high or low; if it is adulterated with 10% or more of cocoanut oil, they form transparent oil drops. Stopper the i lo-cc. flask, mix by inverting 4 or 5 times, avoiding violent shaking, filter through an 8-cm. dry filter fitted close to the funnel, and titrate 100 cc. of the liquid with tenth-normal barium hydroxide solution, thus obtaining the Reichert-Meissl number. After the last drop of distillate has passed through the filter, wash with three 15 cc. portions of water, each of which has previously been used to rinse the condenser tube, the measuring cylinder and the no cc. flask. Then repeat this treatment, using 15 cc. portions of neutral 90% alcohol. Titrate the united alcoholic washings with tenth-normal barium hydroxide solution, using phenolphtalein as indicator. The number of cc. required is the Polenske number. The following results illustrate the value of the method : Reichert-Meissl Polenske Number. Number. 31 samples of butter (Polenske) 23.3-30.1 1.5-3,0 4 samples of cocoanut oil (Polenske) 6.8-7.7 16. 8-17. 8 Oleomargarine (Arnold) 0.5 o-53 Lard (Arnold) 0.35 0.5 Tallow (Arnold) 0.55 0.56 Determination of Soluble and Insoluble Fatty Acids. — A. O. A. C. Method.^ — Soluble Acids. — Five grams are weighed out and trans- ferred to an Erlenmeyer flask of the same size and in the same manner as that used for the Reichert-Meissl process, 50 cc. of alcoholic potash solution are added (40 grams of potassium hydroxide in i Hter of 95% redistilled alcohol) and the flask, provided with a return-flow condenser, is heated on the water-bath till saponification is complete, as evidenced by the clear solution free from fat globules. The alcoholic solution of potash is preferably measured from a pipette, from which it is allowed to drain for a noted interval of time, say thirty seconds. After complete saponification, the condenser is removed and the alcohol is evaporated by further heating. One or more blanks are pre- E. - * U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 47; Bui. 107 (rev.), p. 138. EDIBLE OILS AND FATS. 485 pared at the same time, using the same 50-cc. pipette for measuring, and applying the same time limit for draining the pipette. The blanks are first titrated, after evaporation, with half-normal hydrochloric acid, using phenolphthalein as an indicator. Then add to the flask contain- ing the fatty acids i cc. more of the half-normal acid than is found neces- sary to neutralize the alkali in the blanks, after which the flask is again heated with a funnel in the neck till the fatty acids have completely sepa- rated in a layer on top of the solution. Then cool the flask in ice water till the fatty acids are sohdified, after which decant the liquid portion through a filter, previously dried in the oven and weighed, into a liter flask, keeping the solid mass of fatty acids intact. Next add 200 or 300 cc. of hot water to the flask containing the fatty acids, and again melt over the water-bath till they collect as before on top, having again inserted the funnel to act as a condenser, and occasionally shaking the contents of the flask during heating. Cool as before in ice water, after which again decant the liquid from the solid mass through the same filter into the liter flask. Repeat this process of washing, melting, cooling, and decanting three times, receiving all the wash water through the same filter in the same flask. Make up the washings with water to the liter mark, and, after mixing, two portions of 100 cc. each are titrated with tenth-normal sodium hydroxide, using phenolphthalein for an indicator. Each reading is multiplied by ten to represent the total volume, and the figure thus obtained represents the number of cubic centimeters of tenth- normal alkali necessary to neutralize the acidity of the soluble fatty acids, together with the excess of half-normal acid used, amounting to i cc. This I cc. of half-normal acid corresponds to 5 cc. of tenth-normal alkali, hence 5 cc. are to be deducted from the total number of cubic centimeters required for the titration, the corrected figure thus obtained being multi- plied by the factor 0.0088, which gives the weight of soluble fat acids in the 5 grams of the sample, calculated as butyric acid. Insoluble Acids. — Transfer the fatty acids left in a cake in the flask from the separation of the soluble acids, to a weighed glass evaporating dish, using strong alcohol to wash them out thoroughly. Dry the filter used in the separation, transfer it to an Erlenmeyer flask, and thoroughly wash it with strong alcohol, transferring all the washings to the dish. The alcohol is then evaporated by placing the dish on the water-bath, after which it is dried for two hours in the air-oven at 100°, cooled in the desic- cator, and weighed. After once heating for two hours, cooling and weigh- ing, heat again for half an hour, cool, and weigh. If a considerable loss 486 FOOD INSPECTION AND AN /I LYSIS. in weight is found, heat for an additional half -hour. It is best, "however, to avoid too prolonged heating, lest oxidation of the fatty acids should produce an increase in weight. Hehner's Method. — Transfer the fatty acids left in the original Erlen- meyer flask to the thoroughly wet, tared filter, washing out the flask with hot water, thus bringing all the fatty acids upon the filter, which, if of good quality and thoroughly wet beforehand, will retain them. If, however, oily particles are noticed in the filtrate, they may be solidified by cooling in ice water, and afterwards removed by a glass rod and trans- ferred to the filter. After draining dry, the funnel is immersed in cold water to solidify the fatty acids, and the filter containing them is trans- ferred to a weighed dish, which is dried for two hours in the oven at ioo°, cooled in the desiccator, and weighed, subtracting the weight of the dish and filter. EDIBLE OILS AND FATS ARRANGED IN ORDER OF INSOLUBLE FATTY ACIDS. Mustard oil -... 96. 2 to 95 . i Cottonseed oil 96 "95 Corn oil 96 "93 Lard 96 "93 Peanut oil 95-8 Sesame oil 95-7 Beef tallow 95-6 Mutton tallow 95.5 Poppyseed oil 95-2 " 94-9 Rape oil 95 • i Sunflower oil 95 Olive oil 95 Cocoa butter.' 94-6 Cocoanut oil 90 " 88.6 Butter 89.8 " 86.5 Saponification Number. — Koettstorjef s Method. — By the saponifi- cation number is meant the number of milligrams of potassium hydroxide necessary to completely saponify i gram of the fat. Between i and 2 grams of the fat are transferred in the usual manner (see p. 474) to an Erlenmeyer flask, and 25 cc. of the alcoholic potash solution (40 grams of potassium hydroxide free from carbonates in i liter of 95% alcohol redistilled after standing for some time with potassium hydroxide) are added with a graduated pipette, which is allowed to drain for a noted period of time, say thirty seconds. The determination should preferably EDIBLE OILS AND FATS 487 be made in duplicate. Conduct the saponification as in the case of the soluble fatty acids by heating on the water-bath. After saponification, remove from the bath, cool, and titrate with half-normal hydrochloric acid, using phenolphthaleih as an indicator. Titrate also several blanks in which 25 cc. of the alcoholic potash solution are measured out with the same pipette as before, and allow to drain for the same amount of time. Subtract the number of cubic centimeters of half-normal acid necessary to neutralize the alkali in the case of the saponified fat from that necessary to neutrahze the blank, multiply the result by 28.06, and divide the product by the number of grams of fat taken. EDIBLE OILS AND FATS ARRANGED IN ORDER OF THEIR SAPONIFICA- TION NUMBER. Cocoanut oil Butter Cocoa butter Beef tallow Lard Lard oil Cottonseed stearin Poppyseed oil Cottonseed oil Peanut oil Sunflower oil Sesame oil Olive oil Corn oil Rape oil Black mustard oil White mustard oil. Minimum. Maximum. 246.2 268.4 225 230 192 202 193.2 200 195-3 196.6 195 196 194.6 195 -I 190 198 191 196.6 190 197 193 194 187.6 192.4 185 196 188 193-4 170.2 179.2 174 174.6 170-3 174.6 Mean. 257-3 227.5 197 196.6 196 195-S 194.8 194 193.8 I93-S 193-5 192.6 I9I-5 190.7 174.6 174-3 172.4 The Iodine Absorption Number. — This determination is based on the well-known property of the unsaturated fatty acids to absorb a fixed amount of iodine under given conditions of time, strength of reagent, etc. Hiibl's Method.* — The following reagents are necessary: (i) Iodine Solution, made by dissolving 26 grams of pure iodine in 500 cc. of 95% alcohol, and, separately, 30 grams of mercuric chloride in 500 cc. of the same strength of alcohol. Filter the latter solution, if necessary, and mix the two together, allowing the mixture to stand at least twelve hours before using. (2) Decinormal Thiosulphate Solution, made by dissolving 24.6 grams of the freshly powdered, chemically pure salt in water, and making up to I liter. * A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 24; Bui. 107 (rev.), p. 136. 48 S FOOD INSPECTION AND ANALYSIS. (3) Starch paste, prepared by boiling i gram of starch in 200 cc. of water for ten minutes, then cooling. (4) Potassium Iodide Solution, made by dissolving 150 grams of the salt in water, and making up the volume to i liter.' (5) Potassium Bichromate Solution for standardizing the thiosulphate, made by dissolving 3.874 grams of chemically pure potassium bichromate in distilled water, and making up the volume to i liter. The sodium thiosulphate solution is standardized as follows: 20 cc. of the potassium bichromate solution are introduced into a glass-stoppered flask together with 10 cc. of potassium iodide and 5 cc. of strong hydro- chloric acid. Then slowly add from a burette the sodium thiosulphate solution, till the yellow color of the solution has nearly disappeared, after which a little of the starch paste is added, and the titration carefully con- tinued to just the point of disappearance of the blue color. The reaction which takes place is as follows: K2Cr20,+ 14HCI+ 6KI = 2CrCl3+ 8KC1+ 61+ 7HA The equivalent of i gram of iodine in terms of the thiosulphate solu- tion is found by multiplying the number of cubic centimeters of the latter solution required for the above titration by 5. If, for example, 16.4 cc. of the thiosulphate solution are required for 20 cc. of the bichromate solution, then i gram of iodine is equivalent to 16.4X5 = 82.0 cc. of sodium thiosulphate solution, or i cc. of the thio- sulphate solution =-g\ = 0.0122 gram of iodine, i cc. of exactly deci- normal thiosulphate is theoretically equivalent to 0.0127 gram of iodine. The thiosulphate solution may also be standardized by means of iodine. A short tube closed at one end is tared, together with another tube of such a size as to fit over the first. Into the inner tube are introduced about 0.2 gram of resublimed iodine and the tube heated until the iodine melts, after which it is closed by the second tube and the whole cooled in a desiccator and weighed. The iodine is dissolved in 10 cc. of 10% potassium iodide solution, the solution diluted with water, and the thiosulphate solution added with constant stirring until only a yellow color remains. Starch paste is then added, and the titration con- tinued until the blue color disappears. Manipulation. — Place 0.4 to i gram of the solid fat, or from 0.2 to 0.4 gram of oil, in a glass-stoppered- flask or bottle of 300 cc. capacity. EDIBLE OILS AND FATS. 489 In the case of oils, this may conveniently be done by difference, weigh- ing first a small quantity of the oil in a beaker with a short piece of glass tubing to serve as a pipette, transferring a number of drops of the oil from the beaker to the bottle, and again weighing the beaker and contents. The number of drops of oil required for the desired weight is first ascer- tained experimentally. The material may also be conveniently and accurately weighed in small, flat bottomed cylinders of glass about 10 mm. in diameter and 15 mm. high, which may be made by cutting off so-called " shell vials." Fats are introduced while melted, the weight being taken after cooling. The cylinder and fat are transferred together by means of forceps to the glass-stoppered bottle. Dissolve the oil in 10 cc. of chloroform, and after solution has taken place, add 30 cc. of the iodine solution, shake, and set in a dark place for three hours, shaking occasionally. The excess of iodine should be at least as much as is absorbed. When ready for the titration, add 20 cc. of the potassium iodide solution (the purpose of which is to keep in solution the mercuric iodide formed, which would otherwise precipitate on dilution) and 100 cc. of distilled water. Titrate the excess of iodine by the thiosulphate solution, which is slowly added from a burette till the yellow color has nearly disappeared, then add a little starch paste, and finally thiosulphate solution drop by drop until the blue color of the iodized starch is dispelled. Near the end of the reaction the flask should be stoppered and vigorously shaken, in order that all the iodine may be taken up, and sufficient thiosulphate should be added to prevent a reappearance of any blue color in five minutes. Two blanks are conducted at the same time and in similar flasks or bottles, in exactly the same manner as in the case of the above titration, except that the fat is omitted. This is to get the true value of the iodine solution in terms of the thiosulphate solution. • Suppose, for example, in the case of the blanks, 30 cc. of the iodine solution required in one instance, 46.2 cc. of sodium thiosulphate solution and in the other 46.4 cc. The mean is 46.3. Suppose 30.7 cc. of thio- sulphate solution were required for the excess of iodine remaining over and above that absorbed by 0.5 gram of the fat in the above process. Then the thiosulphate equivalent to the iodine absorbed by the fat would be 46.3 — 30.7 = 15.6 cc, and the per cent of iodine absorbed would be 15.6X0.012^X100 0-5 38.06. 49© FOOD INSPECTION AND ANALYSIS. EDIBLE OILS AND FATS ARRANGED IN ORDER OF THEIR HUBL NUMBER. Lowest. Highest. Average. Poppyseed oil. . . . Sunflower oil . ... Corn oil Cottonseed oil . . . Sesame oil Rape oil Black mustard oil White mustard oil Peanut oil Cottonseed stearin Olive oil Lard oil Lard Beef tallow Mutton tallow . . . Cocoa butter . , . . Butter Cocoanut oil 32.6 143-3 138 18 ^ii-i 125.7 II. 2 130 120.6 08 no 109.5 03 "5 109 94 105 . 99-5 96 no 103 92.1 97-7 94-9 83 103 93 88.7 103.8 91.2 79 88 83.5 56 85 70-5 46 70 58 35-4 47-5 41.4 32-7 46.2 39-5 32 41.7 34.9 25-7 37-9 ii-i 8 9-5 8.7 The Hiibl method has long been ahnost universally used for esti- mating the per cent of iodine absorbed, but is open to serious objections, chief of which are the tendency of the iodine solution to lose strength, and the length of time required to insure saturation of the oil with the iodine. Of late two other methods have come into prominence, viz., the Wijs and the Hanus. The reagents in both these methods hold their strength for months without change, and the time required for carrying out the reaction in the case of most of the edible oils and fats is very short. Of the three methods, that of Hanus has the advantage of greatest simplicity in the composition and preparation of the chief reagent. Tolman and Munson* have shown that with oils and fats having iodine numbers below 100, the three methods give practically identical figures, while with oils having high iodine numbers, the Wijs and Hanus methods give higher results than the Hiibl, but are doubtless more nearly correct. The following are comparative results of the three methods:* * Jour. .-^m. Chem. See, 25 (1903), p, 244. EDIBLE OILS AND FATS. 491 E =3 'Z< ego ►2 2:^:2 o C rt C g M . 36 3 S 2 I 3 I 3 Cocoanut oil Butter — minimum maximum. Oleo oil Oleomargarine — minimum maximum. Lard oil — minimum maximum. Olive oil — minimum maximum. average . . Peanut oil — minimum maximum, Mustard oil — minimum maximum, Rape oil — minimum maximum. Sunflower oil Cottonseed oil — minimum maximum, Sesame oil Corn oil — minimum maximum, Poppyseed oil — minimum maximum 34 35 42 52 66 69 73 79 89 84 94 107 98 113 100 lOI 106 103 106 106 119 123 133 134 9-05 35-9 36.2 43-5 52-9 66.0 70-5 74-5 79-9 91.4 85-3 95-2 109.5 104-3 118. 2 104. 1 105-7 109.2 105.3 107.3 107.0 122.2 129.2 135-2 139-1 8.60 35-4 35-3 43-3 52-0 64.8 69.8 73-9 80.6 90.0 84.6 94-1 107.7 103.8 116. 8 102.8 105.2 107.2 105.2 107.8 106.5 119.6 126.0 132.9 138.4 -f 0.12 + 1.1 + 0.9 + 0.9 + 0.4 -0.3 + 1.2 + 0.7 + 0.7 -f 1.6 + 1-3 -f 0.7 -H.8 + 5-9 + 5.2 + 3-9 + 4-4 -f 2.8 + 1-5 + 1.1 + 0.6 + j-o + 5-8 + 1.8 + 4-2 -0-33 + 0.6 + 0.0 + 0.7 -o-S -1-5 •5 + -1-0.2 + 1-4 -f 0.2 -f 0.6 — 0.1 -t-0.0 + 5-4 + 3-8 -f 2.6 + 3-8 -fo.8 + 1.4 4-1.6 -fo.i + 0.4 + 2.7 -o-S + 3-5 Hanus' Method.* — Reagents. — Iodine Solution. — Dissolve 13.2 grams of pure iodine in i liter of pure glacial acetic acid (99%), and to the cold solution add 3 cc. of bromine, or sufficient to practically double the halo- gen content when titrated against the thiosulphate solution, but with the iodine slightly in excess. Decinormal Thiosulphate Solution, Starch Paste, and Potassium Iodide Solution, as in Hiibl's method. Method of Procedure. — Proceed as in Hiibl's method, substituting 30 cc. of the Hanus iodine reagent for that of Hiibl, stirring the solu- tion before adding the water, and, instead of adding 20 cc. of the potassium iodide solution, use only 10 cc. The excess of iodine should be at least 60% of that added. * Zeits. Unters. Nahr. Genuss., 4, 1901, p. 913. Also Hunt, Jour. Soc. Chem. Ind., 21, 1902, p. 454; U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 136. 492 FOOD INSPECTION AND ANALYSIS. Only half an hour is required for full saturation of the oil by the iodine in the Hanus method, as against three hours in the Hiibl. In case of the non-drying oils and fats, the reaction takes place in from eight to fifteen minutes, though it is best to let the flask set for half an hour at least, in all cases. With oils having an iodine number in excess of IOC, Tolman and Munson recommend one hour's standing. On account of the high coefficient of expansion of acetic acid, care should be taken that the temperature is the same when the iodine solu- tion is measured for the blank and for the determination, as otherwise a serious error may be introduced. Wijs's Method.* — Reagents. — Iodine Solution. — Dissolve 13.2 grams of pure iodine in i liter of pure glacial acetic acid, and pass through the larger portion of this solution a current of carefully washed and dried chlorine gas f until the solution is practically decolorized. Finally add enough of the original solution of iodine in acetic acid to restore the iodine color, so that there is a slight excess of iodine. Hunfs Modified Iodine Solution. — Dissolve 10 grams of iodine tri- chloride in I liter of pure glacial acetic acid, and finally add and dissolve 10.8 grams of pure iodine. Other Reagents, as in the Hiibl and Hanus methods. Method of Procedure. — Proceed as in the Hanus method, observing the same precautions, the only difference being in the use of the Wijs iodine reagent. "Wijs recommends the following periods of time for absorption of the iodine in the case of various oils: For non-dr}'ing oils and fats, such as peanut and olive oil,f fifteen minutes; for semi-drying oils, such as cottonseed, rape, sesame, corn, and mustard, thirty minutes; for drying oils, such as sunflower and poppyseed, one hour. The Bromine Index or Bromine Absorption Number. — The measure of the amount of bromine absorbed by the oils and fats is a useful factor. By the bromine index is understood the weight of bromine which is * Ber. d. chem. Ges., 31 (1898), p. 750. t The chlorine is conveniently prepared by treatment of bleaching powder with dilute sulphuric acid, using gentle heat, and washing the gas by passing through strong sulphuric acid. • X For butter, oleo oil, lard oil, and cocoanut oil, fifteen minutes is sufficient. EDIBLE OILS /IND FATS, 493 absorbed by i gram of a given oil. The bromine index of various oils has been determined as follows: Bromine Index. Observer. 0-835 0.763 0.695 0.645 0.632 0-530 0.500 to 0.544 Levallois Girard Levallois Girard Levallois i Mustard Sesame. Cottonseed Rape Peanut Olive Method 0} Levallois. — Five grams of the oil are saponified with alcoholic potash in a 50-cc. graduated flask by the aid of a gentle heat. At the end of the saponification and after cooling, the flask is filled to the mark with alcohol, and, after shaking, 5 cc. are removed by means of a pipette and transferred to a flask. A slight excess of hydrochloric acid is added to set free the fatty acids, and from a burette a standardized solution of bromine water is run in till with constant shaking a permanent yellow color persists. The bromine is previously standardized with potassium iodide and sodium thiosulphate. The weight of bromine fixed by i gram of the fat is then calculated. Mill's Method. — Modified.-\ — Dissolve o.i gram of the filtered and dried fat in 50 cc. of carbon tetrachloride or chloroform in a loo-cc. stop- pered bottle. From a burette a standard solution of bromine in carbon tetrachloride, approximately tenth-normal (8 grams to a liter), is slowly added to the oil solution till, after fifteen minutes, a permanent coloration remains. The amount of bromine absorbed is calculated by comparing with the color similarly produced in a blank experiment, or an excess of bromine solution may be run in and the solution titrated back with a standard solution of thiosulphate, using potassium iodide and starch. Thermal Tests. — The rise in temperature produced by the action of certain reagents on various oils and fats, when applied in a defi- nite manner, has been found to be of considerable value, especially in th» case of sulphuric acid and of bromine. * Villiers at Collin, Les Substances Alimentaires, p, 680. t Jour. Soc. Chem. Ind., 2, p. 435; 3, p. 366. 494 FOOD INSPECTION AND ANALYSIS. The Maumene Test,* or thermal reaction with sulphuric acid, is most readily carried out in a beaker of say 150 cc. capacity, which is set into a larger beaker or vessel of any kind, the space between the two being packed with felt or cotton waste. The inner beaker is removed, and into it is weighed 50 grams of the oil. It is then replaced and the packing adjusted, if necessary, after which the temperature of the oil is noted with a ther- mometer. From a burette containing the strongest sulphuric acid of the same temperature as the oil, 10 cc. are run into the beaker, at the same time stirring the mixture of acid and oil with the thermometer. The temperature rises somewhat rapidly, and remains for an appreciable time at its maximum point, which should be noted. The difference in degrees centigrade between the initial temperature of the oil and the maximum temperature of the mixture expresses the Maumene number. With certain oils, as cottonseed, considerable frothing ensues when concentrated acid is employed, making an accurate determination of the Maumene number somewhat difhcult. In this case it is better to employ a somewhat weaker acid, and to express results in terms of what is called the "specific temperature reaction." This is the result obtained by dividing the rise of temperature in the case of the oil by the rise of temperature in the case of water, using the same strength of acid, and multiplying the quotient by 100. Indeed, it is of importance in all cases to compare results on oils with those obtained by carrying out the same test on water. Bromination Test. — This test depends upon the avidity with which the oils and fats absorb bromine, the rise in temperature caused by the reaction being measured in this case rather than the actual amount of bromine absorbed, as in the case of the iodine absorption. Indeed, there is such a close relation between the iodine number and the heat of bromination, that when one is determined the other may be calculated quite closely by multiplying by a factor. In view of the fact that the heat of bromination is much more readily determined than the iodine number, it is often convenient to calculate the latter from the former, the result in the case of the edible oils and fats being quite sure to fall within the limits of variation of the iodine number of different oils of the same class. The bromination test was devised by Hehner and Mitchell,! who employed a vacuum jacketed tube for a calorimeter in which to make the test. Various modifications have been suggested both in the * Maumene, Compt. Rend., XXXV (1852), p. 572. t Analyst, XX (1895), p. 146. EDIBLE OILS AND FyiTS. 495 apparatus employed and in the manner of diluting the oil and applying the reagent. The calorimeter employed by Gill and Hatch,* Fig. 96, is conveniently made and is very satisfactory. It consists of a long, narrow, flat-bottomed tube, held by a cork in a small beaker, in such a manner that it is surrounded by an air jacket. The small beaker is set into one of larger size, the space between the two being packed with cotton waste. Five grams of the oil or fat are dissolved in 25 cc. A. B. Fig. 96. A. Gill and Hatch's Calorimeter for the Bromination Test with Oils. B. Wiley's Pipette for Measuring Bromine in Chloroform. of chloroform or carbon tetrachloride, and 5 cc. of this solution (containing i gram of the oil) are transferred by a pipette to the inner tube of the above calorimeter, being careful not to let it flow down the sides of the tube. The temperature of the oil is then taken by a thermometer graduated to 0.2°. The bromine reagent, which should be freshly prepared, is made up by measuring from a burette one part by volume of bromine into four parts of chloroform or carbon tetrachloride. The reagent is transferred to a measuring- flask devised by Wiley,t consisting of a side-necked filter-flask provided with a per- * Jour. Am. Chem. Soc, XXI (1899), p. 27. Gill, Oil Analysis, p. 50. t Jour. Am. Chem. Soc, XVIII (1896), p. 378. 49 1 FOOD INSPECTION AND ANALYSIS. forated rubber stopper into which the stem of a 5-cc. pipette is fittedj Fig, 96. A bulb on the side-neck serves to till the pipette. This pipettci filled to the mark with the bromine reagent (which should be at the same temperature as the oil solution in the calorimeter), is first covered by the finger and removed, and its contents of 5 cc. allowed to flow down the sides of the inner tube of the calorimeter and mingle with the oil without stirring. The rise in temperature is very quick, and the highest point is noted. The difference between the highest and the initial temperature constitutes the heat-of-bromination number. This number, in the case of Gill and Hatch's calorimeter, is somewhat lower than when a vacuum jacketed tube is employed, and differs some- what with the diluent of the oil and bromine. In spite of these variations and that due to the personal equation, concordant results may be obtained with the vaiious oils, when the method is carried out under precisely the same conditions. The analyst should carefully work out the test several times with a particular oil till the results agree, and should then with equal care determine the iodine number of the same oil. The iodine number, divided by the heat-of-bromination number, gives the factor which is to be employed under the same conditions for calculating one constant from the other. In the case of Hehner and Mitchell's work with the vacuum tube, measuring i cc. of undiluted bromine into i gram of oil dissolved in 10 cc. of chloroform, it was found that the factor to be used in calculating the iodine number was 5.5. The following are some of the results on edible oils obtained by Hehner and Mitchell: Oil. Heat of Bromination. Iodine Number. Calculated Iodine Number. Lard 10.6 6.6 15 21-S 19.4 57-15 37-07 80.76 122 107.13 58.3 Butter 36.3 82.5 118. 2 106.7 As in the case of the Maumene test with sulphuric acid (wherein the rise in temperature of sulphuric acid and water is taken as a standard), it is convenient to employ some standard for the bromination test, whereby varying results due to difference in apparatus, etc., may be compared. In this case Gill and Hatch found that sublimed camphor may be prepared sufficiently pure to be used for such a standard. Applying the bromination test with their calorimeter, as above described, to 5 cc. of a EDIBLE OILS yfND F^TS. 497 solution of 7I grams of camphor in 25 cc. of carbon tetrachloride, an average rise in temperature of 4.2° was obtained, and the specific temperature reaction is calculated for each oil by dividing the heat of bromination by this number. Furthermore, by dividing the iodine number of several oils by this specific temperature reaction, the factor to be employed for the calculation of the iodine number was found to be 17.18, as in the fol- lowing cases:* OiL Specific Tem- perature Reaction. Iodine Number. Calculated. Found. Prime lard No. I lard. Olive Cottonseed Corn 3-705 4.096 4.762 5.667 6.381 63.8 70-3 81.8 97-3 109-5 63.8 73-9 82.0 103.0 107.8 The Acetyl Value. — On heating fats with acetic anhydride they become "acetylated" ; i.e., the hydrogen atom of their alcoholic hydroxyl group is exchanged for the acetic acid radicle, in accordance, for example, with the folio winsr reaction: Ci7H3,(OH)COOH+ (aHsO)^© = Ci7H32(0,C,H30)COOH+ QH.O^ Ricinoleic acid Acetic anhy- dride Acetyl-ricinoleic acid Acetic acid By the actyl value is meant the number of milligrams of potassium hydroxide necessary to neutralize the acetic acid formed by the saponifi- cation of I gram of the acetylated fat. Lewkowitsch's method of procedure is as follows: 10 grams of the oil are boiled with an equal volume of acetic anhydride for two hours in a flask with a return-flow condenser, and the mixture is then trans- ferred to a large beaker containing 500 cc. of water, and boiled for half an hour. To prevent bumping, a current of carbon dioxide is slowly passed through it during the boiling, introduced through a finely drawn, bent glass tube reaching nearly to the bottom of the beaker. The mix- ture on standing separates into two layers, of which the lower, or aqueous layer, is siphoned off, and the oily layer boiled with fresh portions of * Gill, Oil Analysis, p. i 28. 498 FOOD INSPECTION /1ND ANALYSIS. water, which are in turn siphoned off, the operation being repeated till the wash water tests free from acid by Htmus paper. The acetylated fat is then separated from the water by drying at 1 00° in an oven. From 2 to 4 grams of the acetylated fat is weighed into a flask, and saponified with alcoholic potash in precisely the same manner as for the determination of the saponification number. Evaporate the alcohol and dissolve the soap in water. One of two methods may be carried out for freeing the acetic acid for titration, one by distillation and the other by filtration. For the former or distillation process, acidify the aqueous solution of the soap with i : 10 sulphuric acid, and distill in the same way as in the Reichert process, excepting that in this case from 600 to 700 cc. of dis- tillate must be obtained, so that water should be added from time to time through a stoppered funnel fixed in the cork of the distilling-flask. The distillate should be received in a funnel with a loose cotton plug, so as to filter it free from insoluble acids mechanically carried over. The filtrate is titrated with tenth-normal sodium hydroxide, using phenol- phthalein as an indicator. The number of cubic centimeters of alkali used is multiplied by 5.61, and the product divided by the number of grams of acetylated fat taken. The result is the "acetyl value. If the filtration process is used (which is more rapid and should give concordant results with the distillation process), the exact amount of alcoholic potash used in the saponification should be accurately measured in carrying out the former part of the test, and the exact number of cubic centimeters of standard acid corresponding to the amount of alkali employed should be added to the aqueous soap solution. The mixture should be gently warmed, and the fatty acids will gather in a layer at the top. These are filtered off and washed, till free from acid, with boiling water. The filtrate is titrated with tenth-normal sodium hydroxide, and the acetyl value calculated as in the distillation process. EDIBLE OILS ARRANGED IN ORDER OF ACETYL VALUE. Average. Cottonseed oil 18.0 Rape oil 14.7 Poppyseed oil 13 . i Sesame oil 11. 5 OHve oil 10.6 Peanut oil 3.4 EDIBLE OILS /1ND FATS. 499 The Valenta Test. — This depends upon the solubility of the oil in glacial acetic acid. Pour from 3 to 5 cc. of the oil into a test-tube, and add an equal volume of glacial acetic acid (specific gravity 1.0562). Place a thermomeler in the tube and warm gently till the oil goes into solution. Then allow the mixture to cool, and observe the temperature at which the solution begins to appear turbid. Castor oil and oil of the olive kernel are soluble in glacial acetic acid at ordinary temperatures, while rape and mustard seed oils are insoluble even in the boiling acid. Elaidin Test. — This is based on the conversion by nitrous oxide of liquid olein into the solid elaidin, a crystalline compound isomeric with olein, while other common glycerides remain liquid under treatment with this reagent. By the consistency of the final product, when sub- jected under certain conditions to the action of nitrous oxide, some idea as to the character of the oil may be gained. Manipulation. — To carry out the test according to Pontet (modified), weigh 5 grams of the oil into a beaker, add 7 grams of nitric acid (specific gravity 1.34) and about 0.5 gram of copper wire. Place the beaker in water at 15° and stir thoroughly with a glass rod in such a manner as to make an intimate mixture of the oil and the evolved nitrous oxide gas. After the wire has been dissolved, add another piece of about the same size and again stir vigorously. Set aside for about two hours, at the end of which, in the case of pure olive, almond, peanut, or lard oil, it will have been changed into a solid white mass. Nearly all the seed oils, especially cottonseed and mustard, are turned into a pasty or buttery mass. Another modification of Pontet's test consists in mixing 10 grams of the oil, 5 grams of nitric acid (specific gravity 1.38), and i gram of mercury in a test-tube, shaking for three minutes and allowing to stand twenty minutes, when it is again shaken. The behavior of various oils after that time on further standing is as follows : Solidified after Olive oil 60 minutes Peanut oil 80 " Sesame oil 185 " Rape oil 185 " Free Fatty Acids.* — Weigh 20 grams of the oil or fat into a 150-cc. Erlenmeyer flask, and add 50 cc. of 95% alcohol, which has previously * Allen, Com. Org. Anal., 4 Ed., Vol. II, p. 9. 500 FOOD INSPECTION AND ANALYSIS. been carefully neutralized with a weak solution of sodium hydroxide, using phenolphthalein as an indicator. Warm the mixture to about 60°, and add carefully from a burette tenth-normal sodium hydroxide (using the above indicator) till a pink color is produced, shaking thoroughly during the titration. The result may be reported in terms of percentage of oleic acid (each cubic centimeter of tenth-normal alkali is equivalent to 0.0282 gram of oleic acid) or as the "acid number," by which is meant the number of cubic centimeters of tenth-normal alkali necessary to saturate the free acid in i gram of the fat or oil. Constants of the Free Fatty Acids. — Often much information as to the character of an oil or fat may be obtained by determining such con- stants of its fatty acids as the melting- and solidifying-point, the iodine number, etc. To prepare the fatty acids for examination, saponify a quantity of the oil or fat with alcoholic potash, evaporate the alcohol, and dissolve the soap in hot water. Decompose the soap by the addition of an excess of hydrochloric or sulphuric acid, continuing the heating till the fatty acids rise in a layer to the top of the liquid, from which they may be removed. The melling-point, iodine number, etc., are determined as with the oil or fat itself. Solidifying-point of the Fatty Acids, or Titer Test. — Modified Wolfbauer Method.'^ — Saponify 75 grams of fat in a metal dish with 60 cc. of 30% sodium hydroxide (36° Baume) and 75 cc. of 95% by volume alcohol or 120 cc. of water. Boil to dryness, with constant stirring to prevent scorching, over a very low flame, or over an iron or asbestos plate. Dissolve the dry soap in a liter of boiling water, and if alcohol has been vised, boil for forty minutes in order to remove it, adding sufficient water to replace that lost in boiling. Add 100 cc. of ^^0% sulphuric acid (25° Baume) to free the fatty acids, and boil until they form a clear, trans- parent layer. Wash with boiling water until free from sulphuric acid, collect in a small beaker, and place on the steam bath until the water has settled and the fatty acids are clear; then decant them into a dry beaker, filter, using a hot-water funnel, and dry twenty minutes at 100° C. When dried, cool the fatty acids to 15 or 20° C. above the expected titer, and transfer to the titer tube, which is 25 mm. in diameter and 100 mm. in length (i by 4 inches), and made of glass about i mm. in thickness. Place in a i6-ounce saltmouth bottle of clear glass, about 70 mm. in diameter and 150 mm. high (2.8 by 6 inches), fitted with a cork, wliich is perforated so as to hold the tube rigidly when in position. Suspend the * A. O. A. C. Method, U. S. Dept. of Agric, Bur, of Chem.. Bui. 107, p. 135. EDIBLE OILS AND FATS. 501 thermometer, graduated to 0.10° C, so that it can be used as a stirrer, and stir the mass slowly until the mercury remains stationary for thirty seconds. Then allow the thermometer to hang quietly, with the bulb in the center of the mass, and observe the rise of the mercury. The highest point to which it rises is recorded as the titer of the fatty acids. Test the fatty acids for complete saponification as follows: Place 3 cc. in a test tube and add 15 cc. of alcohol (95% by volume). Bring the mixture to a boil and add an equal volume of ammonium hydroxide (0.96 sp. gr.). A clear solution should result, turbidity indicat- ing unsaponified fat. The titer must be made at about 20° C. for all fats having a titer above 30° C. and at 10° C. below the titer for all other fats. The thermometer must be graduated in tenth degrees from 10° to 60°, with a zero mark, and have an auxiliary reservoir at the upper end, also one between the zero mark and the 10° mark. The cavity in the capillary tube between the zero mark and the 10° mark must be at least i cm. below the 10° mark, the 10° mark to be about 3 or 4 cm. above the bulb, the length of the thermometer being about 15 inches over all. The ther- mometer is annealed for 75 hours at 450° C, and the bulb is of Jena normal 16"' glass, moderately thin, so that the thermometer will be quick acting. The bulb is about 3 cm. long and 6 mm. in diameter. The stem of the thermometer is 6 mm. in diameter and made of the best thermometer tubing, with scale etched on the stem, the graduation to be clear cut and distinct, but quite tine.* Unsaponifiable Matter. — As will be seen by reference to the table on page 509, the unsaponifiable matter in pure edible oils and fats is comparatively insignificant in amount, consisting largely of cholesterol or phytosterol. A high content of unsaponifiable matter is indicative of adulteration, pointing to the presence of mineral or coal-tar oils, or to paraffin. Detsrmination of Unsaponifiable Matter.f — Weigh 7 to 10 grams of the fat or oil in a 250-cc. flask, and saponify by boiling with 25 cc. of alcoholic potassium hydroxide and 25 cc. of alcohol under a return- flow condenser. After saponification, add 30 to 40 cc. of water, and bring to the boiling-point. Cool and transfer the contents from the flask to a separatory funnel, washing out the flask first with a small amount * Tolman, U. S. Dept. of Agric, Bur. of Chem., Bui. 90, p. 75. t Honig and Spitz, Jour. Soc. Chem. Ind., 1891, p. 1039. 5:^2 FOOD INSPECTION /1ND ANALYSIS. of 50% alcohol, and finally with 50 cc. of petroleum ether (B.P. 40^-70°), adding both washings to the separatory funnel. Shake the latter thoroughly, but avoid if possible forming an emulsion. If the latter persists in forming, add a volume of water equal to that of the soap solu- tion, which will sometimes break it up. After separation of the petro- leum ether layer, draw off the underlying soap solution into a beaker, and wash the petroleum ether two or three times with 50% alcohol, which is drawn off and added to the soap solution. The petroleum ether is then run into a tared Erlenmeyer flask, and the soap solution extracted twice more with fresh portions of petroleum ether, washing the ether each time with 50% alcohol as before and then transferring the ether to the tared flask. The petroleum ether is then removed by placing the flask on the water-bath, bumping being prevented by means of a spiral «of platinum wire weighed with the flask. Finally remove all traces of remaining ether by blowing hot air through the flask, or, in the absence of mineral oils (some of which are volatile), dry in the water-oven to con- stant weight, cool in a desiccator, and weigh. Cholesterol and Phytosterol. — These are monatomic alcohols, and combine with the fatty acids forming esters. Both respond to the same reactions, and are separated by the same process from the oils and fats in which they occur. Phytosterol was long thought to be the same as cholesterol, and some confusion seems to have arisen from the fact that early writers purport to have found cholesterol in vegetable oils, when in reality the substance was phytosterol. The latter was first distinguished from cholesterol by Hesse, who named it. Cholesterol (C26H44O) crystalhzes in white, nacreous, monoclinic laminre, having a melting-point of 145° and specific gravity 1.067. ^^s reaction is neutral, it is devoid of taste or smell, insoluble in water, sparingly soluble in cold, but readily soluble in boiling alcohol, and soluble in ether, chloroform, methyl alcohol, benzene, and oil of turpentine. It sublimes unchanged at 200°, but at higher temperatures decomposes. Commercial cholesterol is obtained from wool oil and is known as lanolin, being used largely in medicine as a basis for ointment. Cholesterol occurs also in the yolk of eggs, in many animal secretions, and in most animal oils and fats. It separates in laminated, transparent crystals from a mixture of 2 volumes alcohol and i volume ether, and in the form of anhydrous needles from chloroform. Phytosterol (C26H^^O,H20) is most abundantly found in the legu- EDIBLE OILS JND F^TS. 503 minous seeds, and is prepared commercially from these, especially from peas and lentils. It is a constituent of most vegetable oils. It crystallizes in slender, glittering plates from chloroform, ether, and petroleum ether, and from alcohol in tufts of needles. In solubility it much resembles cholesterol, but its melting-point from 132° to 134° is lower. Determination of Cholesterol and Phytosterol. — MetJwd of Forster and Reichmann* — 50 grams of the oil or fat are boiled for five minutes in a flask connected with a reflux condenser with two successive portions of 75 cc, of 95% alcohol, and in each case the alcoholic solution is sepa- rated by means of a separatory funnel. The combined alcoholic solutions are then boiled in a flask provided with a funnel in the neck, till one- fourth of the alcohol is evaporated, and then poured into an evaporating dish and brought to dryness. The residue is then extracted with ether, and the ether solution is evaporated to dryness, taken up again with ether, filtered, evaporated once more, and dissolved in hot 95% alcohol, from which it is allowed to crystallize. Cholesterol or phytosterol will crys- tallize out under these conditions, and may be weighed. Distinguishing between Cholesterol and Phytosterol. — It is some- times of importance to determine which of these substances is present in an oil, or whether indeed both occur. Confirmatory proof as to the presence of vegetable in animal oils may, for instance, be established by showing whether the unsaponifiable residue in the sample contains choles- terol or phytosterol or both. Hehner f has made use of this test in deter- ■ mining the presence of cottonseed oil in lard. The most ready means of distinguishing between cholesterol and phytosterol is furnished by the marked difference between the form of the crystals, the manner of crystalhzation of the two substances, and the melting points of the acetates. Separation and Crystallization of Cholesterol and Phytosterol. — Bomer's Method.X — Saponify 100 grams of the fat by heating in a liter Erlenmeyer flask on a boiling water bath with 200 cc. of alcoholic potash Sfjlution (200 grams of potassium hydroxide 4- 1 liter of alcohol). The flask should be provided with a perforated rubber stopper, through which passes a glass tube 700 cm, long, which serves as a reflux condenser. During the first part of the heating shake often and vigorously until the solution is clear, after which continue the heating one-half to one hour longer with occasional shaking. * Analyst, 22, 1897, p. 131. t Ibid,, 13, 1888, p. 165. X Zeits. Unters. Nahr. Genuss., i, 1898, p. 31. , 504 FOOD INSPECTION yIND ANALYSIS. While still warm, transfer to a separatory funnel of about 1.5 liters capacity, rinsing the flask with 400 cc. of water. When cool, add 500 cc. of ether, shake vigorously for one-half to one minute, opening the cock repeatedly, and allow to stand for two to three minutes until the liquids separate. Remove the ether solution to a flask, and distil o^ the ether, using a few pieces of pumice stone to prevent bumping. Shake the soap solution two to three more times in the same manner with 200 to 250 cc. of ether, add the ether solution after each shaking to the residue in the distiUing flask, and distil off the ether. Usually a small amount of alcohol remains in the flask after removal of the ether, which may be removed by heating on a boiling water bath in a blast of air. To saponify any remaining fat, add 20 cc.of the alcoholic potash solution, and heat for five to ten minutes as before. Transfer to a small separatory funnel, rinse with 40 cc. of water, cool and shake with 150-200 cc. of ether from one-half to one minute, allow to stand two to three minutes, and draw off the lower layer. Wash the ether solution three times with ic-20 cc. of water, filter, to remove drops of water, into a small beaker, and remove the ether by cautious evaporation on the water bath, thus obtaining the crude cholesterol or phytosterol. The unsaponifiable residue, which may be weighed after drying, in the case of animal fats shows beautiful radiating crystals, and consists largely of cholesterol, while in the case of vegetable fats it consists largely of phytosterol. Dissolve the residue in 4-20 cc. of absolute alcohol with the aid of heat, and allow to crystallize slowly in a shallow dish. The crystallization in the case of cholesterol alone begins from the margin of the liquid and gradually extends inward toward the center, forming a uniformly bright, thin, colorless film over the whole surface. This film is best removed with a knife or spatula and pressed between filter-paper. The film will be seen, even megascopically, to be composed of large, glossy plates with a silk-like luster. After the removal of the first film a second will form similar to the first, but composed as a rule of smaller crystals. These are removed in like manner, dried between filters, and added to the first in a glass. After the second crop, the mother liquid is thrown away. The crystals are then redissolved in absolute alcohol, and again allowed to separate out, being repeatedly recrystallized till the melting-point is constant. In lard and most fats the crystals were found pure by Bomer after the second crystallization. Phytosterol is crystallized with greater difficulty, especially when derived from seed oils, on account of the presence of pigments and other EDIBLE OILS AhJD FATS. 50s foreign matter. The first procedure is the same as above described for cholesterol, the crystals being allowed to separate slowly out of a solu- tion in absolute alcohol. Unlike cholesterol, no film is formed on the surface, but needles (sometimes i cm. in length) are gradually elim- inated, beginning at the margin and extending inward mostly at the bottom. In concentrated solutions, fine needles would be uniformly deposited through the liquid. These are best separated from the mother liquid by filtration, as they are not easily taken out with a knife. They may be washed on the filter with small amounts of absolute alcohol for microscopical examination, or repeatedly recrystallized, as in the case of cholesterol, till the melting-point is constant. I. Cholesterol Crystals. — When crystallized separately under above conditions, cholesterol crystals viewed under the microscope show generally rhomboidal forms of plates, as in Fig. 97, but sometimes with a reenter- FiG. 97. — Cholesterol Crystals under the Microscope. (A.fter Bomer.) ing angle. The plates are often grown together in masses. The most characteristic forms are found from the first crystallization or from the first film removed. Sometimes quadrilateral crystals predominate amcng the plates, often also the other shapes shown are found most numerous. 2. Phytosterol Crystals. — Pure phytosterol crystallizes in needles or narrow plates, arranged commonly in star form or in bunches. The most common forms are shown in Fig. 98, best conditions as to shape of crystals being obtained from slow crystallization, in which case the needles are finer and more regular. The crystals are commonly in the form of long, narrow plates, thin and slender, often pointed at both ends. Sometimes the points are lacking, or the ends are beveled. The more frequently they are re- crystallized, the larger and more varied are the crystal forms. The broad, hexagonal and quadrilateral plates shown are products of re- 5o6 FOOD INSPECTION AND AN /I LYSIS. crystallization; the shorter forms are rarely met with. Sometimes various forms are found side by side in the same crystallization. Phytosterol crystals, from a second oi* third recrystallization, some- times grow together in bunches resembling at fitst glance to the naked eye the cholesterol masses. They never do this in the first crystallization^ whereas in the case of cholesterol the growing together in masses is very characteristic of the first crystallization. Fig. 98. — Phytosterol Crystals. (After Bomer.) Thus for purposes of distinguishing between the two the product of the first crystallization is best observed. 3. Crystals of Mixed Cholesterol and Phytosterol. — In mixtures of the two they do not crystallize separately^ but when in nearly equal propor- tion, or with phytosterol predominating, the crystals much resemble phytosterol. Even when cholesterol predominates to the extent of 20 parts to I of phytosterol, the mode of crystallization leans most toward that of phytosterol, though the needles are of different shape. Such a mixture, for instance, does not form in a film like cholesterol, but, like phytosterol, comes out in needle-like bunches. The needles, however, are more often like those shown in Fig. 99 when viewed under the micro- ^jJ Fig. 99.— Characteristic Forms of Crystallization of Mixed Cholesterol and Phytosterol (After Bomer.) scope, showing needles for the most part squarely cut off at the ends, and sometimes placed end to end, and of varying diameter, giving the appearance of a spy-glass. When cholesterol predominates over phy- tosterol 50 to I, the plates resemble those of cholesterol. EDIBLE OILS AND FATS, 507 Bomer's Phytosterol Acetate Test for Vegetable Fats.* — Dissolve the crude cholesterol or phytosterol, or the mixture of the two, obtained by Bomer's method, as described on page 503, in the smallest possible amount of absolute alcohol, and allow to crystallize. Examine under the microscope the first crystals that separate, comparing with the cuts and descriptions given in the preceding section. Remove the alcohol completely by evaporation on the water bath, add 2 to 3 cc. of acetic anhydride, cover with a watch glass, and boil for one-fourth minute on a wire gauze; then remove the watch glass, and evaporate the excess of acetic anhydride on the water bath. Heat the residue with sufficient absolute alcohol to dissolve the esters, and add enough more to prevent immediate crystallization on cooling. Cover until the room temperature is reached and allow to crystallize. After one-half to one-third of the liquid has evaporated and the greater part of the esters have crystallized, transfer the crystals to a small filter by the aid of a small spatula, rinsing with two portions of 2 to 3 cc. of 95% alcohol. Return the crystals to the crystallizing dish, dissolve in 5 to 10 cc. of absolute alcohol, and again allow to crystaUize. After the greater part of the crystals have separated, collect on a filter as before. Repeat the recrystallization several times (5 to 6 is usually sufficient), determining the melting point of the crystals after each recrystallization beginning with the third. If after the last crystalhzation the corrected melting point of the crystals is above 116°, the presence of a vegetable fat or oil is indicated, if it is 117° or higher the proof may be regarded positive. The standard thermometer used should be graduated to tenths of a degree. Correct the reading by the following formula: S = r + o.oooi54«(r — /) in which 5=^ the corrected melting point, 2" = the observed melting point, w = the length of the mercury column above the surface of the liquid, expressed in degrees, and if = the temperature of the air about the mercury column as determined by a second thermometer. Bomer states that by this method the analyst can detect in edible animal fats i to 2 per cent of oils rich in phytosterol (cottonseed, peanut, sesame, rape, hemp, poppy, and Unseed), and 3 to 5 per cent of oils con- taining smaller amounts of this constituent (ohve, palm, palm kernel, and probably cocoanut). He found the corrected melting point of choles- terol acetate to be 114.3° to 114.8° and of phytosterol acetate, 125.6° to 137.0° according to the source. * Zeits. Unters. Nahr. 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CO i a 00 " "^ •* 00 1 s c ^ N C ■O ^ ■* N 1 CO 1 o ^l ,M c in o^Sg ° o Oo o o °oo Ovo-' 3 3 N -^ t,u B-^S^S^So •* O--' h O - 0> "N o. r^ o to av o Ov •* o^ t~ o-o o m O>01 D OO 0> ► < --t (> t o o r^ o>vo o. 1 to . Tf . to . tv . 1 a 1- " o. o c l>o c >o ao O o CKO o^oo^oo^oc^oc^oo^oo^oo> aoc^oo^oc^o mO^ o c c o o oooooooooooo rt 1 s "<■ • c 2 ^ i i c o c 16 ^ o s 'c < 'c = I i c 3 C * 'c ; T C c c c 3 „ f i 1 ; £ cti . a- • Q. 'c > O 'c 1- '. T a ; ( c ) i i I ] 1 p ■ i 3 "cS ; 3 EDIBLE OILS AND FATS. 509 fO „ (D ^ ■* 10 0. ro M ►2 § a 5-t VO ; 0. ^ '^ 00 z >-' M - CT o> CO to CO ■a 5/ . -t cc " ^ ^ r- -t Tt 1 >! N w f^ ro M *-* c^ t Tj- in Tf ■5.C 000 t^ ^ ; 0000 d '—' -t-> ^J -fj -t^ •H -*J . +-' +j +-> ^J -M 4-> Ph ^a w N CO lA «3 mD ir t^ ^ 03 >/- to to 01 CO Id M ^^ rO (N M ►■ M N M Tf "*"* M 0) • rO «'sC +-> ■^ M ° Tt„-^ -^ ,0.0 '" 5 N ■* f' ) 1/ N "_ ■^ 10 10 t^ Tf to IH IH M " d to « d 5b= £lo to . 2 8 f^.-S's +J *?! lA * 1000 1' 00 • si;3o •* c^ ■* u- '?" u< fe ++ CC++ ^ to ^o ,^>o ++ ++ Tl , . 5 ^ t- ^ VC 00 c t^o ■^co *' 00 ^13 M . r^ fO vO t- *;■ «*^ w C <> t>- c „ *~ rt.*j bi) S ° £ & 0)^ c C c 0000 ESS •* n 1 « « cs T r ■<: 1- « w ro t T f -t ^ •* tf e^-tS eiss actom- Read- ng. ■* ^ c C ^ « 5^1 05^ 0;;,^ ^ ^5 VO - ^c j^, >o >c "> " ■> ^ ■> C^ ^ -^ M >o t ^ -^ pil 0) 00 0^ o'^o'? ° M M VO u o'i3 K« ^ 0* ^O r^ VO • c rt *c 'c • 'C t-r 'c 'c ' "c ■ t: ~ t- t: 1- a: 1- •1- 'c & > e e ^ c '■ £ I E oj c 1 ^ •^ 1 a) rt c CJ "S ^ -2 "oj ti i- (£ V c C c C^ « s ^ ^ c3 s c3 CI S 3 1 CQ U Z ^ ts ft ^- c O W O > K fl J O H S 5IO FOOD INSPECTION AND ANALYSIS. Numerous experiments, made both in Europe and America, show that feeding milch cows and swine with oil cakes does not introduce phytos- terol into either the fat of the milk or the lard, although both fats may respond to the Halphen test, or give abnormally high Polenske numbers as a result of feeding with cottonseed or cocoanut cake respectively, and although the lard (not the butter fat) may respond to the Baudouin test, owing to feeding with sesame cake. (See pp. 531, 560). Paraffin, sometimes present as an adulterant of fats, is best deter- mined as follows:* Boil 2 grams of the fat with 10 cc. of 95% alcohol and 2 cc. of 1:1 sodium hydroxide solution, connect the flask with a reflux condenser, and heat for an hour on the water-bath, or until saponification is complete. Remove the condenser, and allow the flask to remain on the bath till the alcohol is evaporated off and a dry residue is left. Treat the residue with about 40 cc. of water and heat on the bath, with frequent shaking, till everything soluble is in solution. Wash into a separatory funnel, cool, and extract with four successive portions of petroleum ether, which are collected in a tared flask or capsule. Remove the petroleum ether by evaporation and dry in the oven to constant weight. It should be noted that any phytosterol or cholesterol present in the fat would come down with the parafhn, but the amount would be so insig- nificant that with added paraffin actually present, it may be disregarded. The character of the final residue should, however, be confirmed by determining its melting-point and specific gravity, and by subjecting it to examination in the butyro-refractometer. The melting-point of paraffin is about 54.5° C; its specific gravity at 15.5° is from 0.868 to 0.915, and on the butyro-refractometer the reading at 65° C. is from II to 14.5. MICROSCOPICAL EXAMINATION OF OILS AND FATS. Excepting in the case of solid fats, the use of the microscope has hitherto been comparatively restricted. In the examination of lard and butter for adulterants, the use of the microscope is often of great value, and will be described more fully under these special fats. In general the best fat crystals are obtained by slow crystallization at room tempera- ture from an ether solution, or from a mixture of ether and alcohol. The first crystals formed may often with advantage be filtered out, and washed with the alcohol and ether mixture on the filter, dissolved finally in ether, and the latter allowed to evaporate spontaneously. The crystals are then examined in a medium of ether. t U. S. Dept. of Agric, Div. of Chem., Bui. 65, p. 46. EDIBLE OILS yIND FATS. 5" If it be desired to separate the liquid oleins from an oil, so that crystals of the solid fats are left for examination, Gladding* recommends dis- solving the fat in a mixture of two volumes of absolute alcohol and one volume of ether in a test-tube, which is stoppered with cotton and set for half an hour in ice water, during which time the more solid stearin and palmitin will have crystallized out. This portion is then separated from the mother liquor by filtration through an alcohol- wet filter- paper, and the crystals finally treated as in the preceding section, being examined in a medium of olive or cottonseed oil. OLIVE OIL. Source. — Olive oil is derived from the fruit of the cultivated thorn- less olive tree, Oka EuropcEa sativa,'\ of which there are a great many varieties, originally grown in Asia Minor, Greece, Palestine, and southern Europe, and now cultivated extensively in California, Peru, and Mexico, as well as in Australia. Most of the olive oil of commerce, especially of the choicest varieties, is supplied by southern France, Spain, and Italy. The tree is an evergreen of slow growth and great longevity. The ripe olive fruit is purple or purplish black in color ; it is round or oval in shape, and from 2.5 to 4 cm. in diameter. The oil is contained in the parenchyma cells of the fruit suspended in a watery fluid, A thick skin incloses the fruit, and within is a kernel, which itself contains oil. The fruit contains from 40 to 60 per cent of oil. According to Brannt,f the average composition of the olive is as follows: Flesh, Per Cent. Stone, Per Cent. Seed, Per Cent. Oil Organic substances Nitrogen therein Ash Water . , 56-4 16.70 2.68 24.22 5-75 85.89 4.16 4.20 2.50 12.26 79-38 2.16 6.20 2.16 Preparation. — The finest virgin oil is produced from hand-picked, peeled olives, from which the kernels or pits have been removed. A somewhat inferior grade of oil is produced from the whole olive including the pit, while a distinctly low grade oil is obtained from the stones, or kernels, which are ground into a coarse meal and subjected to pressure, or to the action of such solvents as carbon bisulphide. * Jour. Am. Chem. Soc. 1896, 18, p. 189. t As distinguished for the wild thorny species, Europcea sylvestris. X Animal and Vegetable Fats and Oils. 512 FOOD INSPECTION AND ANALYSIS. In the process of manufacture the fruit, after first being dried, is re- duced to a pulp in a stone or iron mill, and the pulpy mass, contained in baskets or bags, is subjected to pressure in an iron press. The very highest grade of virgin oil is that which runs out from the pulp with little or no pressure. After the first pressing, the pomace is ground, treated with water, and again subjected to pressure. Several pressings in this manner may be carried out, each yielding an oil inferior to that preceding, the lowest gradco being used for lubricants and in the manufacture of soap. Nature and Composition. — The better grades of olive oil, suitable for table and medicinal purposes, possess a pleasant, bland taste, and a distinctive and agreeable odor, unmistakable in character for that of any other oil. The finest virgin oil is pale green in color, due to the presence of chlorophyll, which is closely associated with the oil globules in the cellular tissue of the fruit. Some varieties of olive oil are nearly color- less, while others are a deep golden yellow. Olive oil contains 28% of solid glycerides, chiefly palmitin and a very small amount of arachin, and 72% of liquid glycerides, mainly olein with a little linolein. Stearin is practically absent. Lewkowitch * states that olive oil differs from most vegetable oils in containing cholesterol but not phytosterol. Gill and Tufts t show that olive oil is not thus excep- tional, but that the unsaponifiable alcohol is phytosterol and not cholesterol. Olive oil is very soluble in chloroform, benzol, and carbon bisulphide, but is sparingly soluble in alcohol. Five parts of ether will dissolve 3 parts of the oil. For customs purposes the United States Government considers a gallon equivalent to 7.56 pounds which is slightly below the truth. Adulterants. — ^As a rule the low grade olive oils are most subject to adulteration, by reason of the fact that it hardly pays to destroy or even modify the fine quality and delicacy possessed by a first-class oil, which would inevitably be the result if even a small amount of foreign oil were added. Furthermore, if olive oil be slightlyrancid or for any reason lacking in flavor, the admixture of a bland oil tends rather to minimize the fact. The most common adulterant of olive oil in this country is naturally cottonseed oil, which is often substituted wholly for it. In Europe peanut oil is sometimes used both as an admixture and even as a substi- tute since it possesses in itself a rather pleasant flavor, rendering it especially adapted for use as an adulterant. Other cheap oils used for this purpose are corn, mustard, poppyseed, rape, sesame, and sunflower * Chem. Anal, of Oils, Fats, and Waxes, 2d ed., p. 452. t Jour. Am. Chem. Soc, XXV, 1903, p. 498. EDIBLE OILS ^ND FATS. 513 oil. The writer has also found in samples of alleged olive oil sold in Massachusetts cocoanut oil* and even fish oil. Pure Olive Oil of the U. S. Pharmacopoeia. — The requirements of the Pharmacopoeia are as follows: Specific gravity, 0.910 to 0.915 at 25° C. (77° F.) ; iodine value not less than 80 nor more than 88; saponification value 191 to 195. Very sparingly soluble in alcohol, but readily soluble in ether, chloroform, or carbon disulphide. When cooled to about 10° C. (50° F.), the oil should become some- what cloudy from the separation of crystalline particles, and at 0° C. (32° F.) it should form a whitish, granular mass. If 2 cc. of olive oil be shaken vigorously with an equal volume of nitric acid (sp. gr. 1.37), the oil should retain a light yellow color, not becoming orange or reddish brown, and after standing for six hours, should change into a yellowish-white solid mass and an almost colorless liquid (absence of appreciable quantities of cottonseed oil and other seed oils). Olive oil should not show the cottonseed oil reaction with the Bechi and Halphen test, p. 518, northe sesameoil reaction with the Baudouin test, p. 519. U. S. Standards. — Olive oil is the oil obtained from the sound, mature fruit of the cultivated olive tree {Olea europoea L.) and subjected to the usual refining processes; is free from rancidity; has a refractive index (25° C.) not less than 1.4660 and not exceeding 1.4680; and an iodine number not less than 79 and not exceeding 90, Virgin olive oil is olive oil obtained from the first pressing of carefully selected, hand-picked olives Reaction with Strong Acid. — Pure olive oil, when shaken or stirred with an equal volume of concentrated nitric or sulphuric acid, turns from a pale to a dark-green color in a few minutes. If, under this treatment, a reddish to an orange, or brown coloration is produced, the presence of a foreign vegetable oil (usually a seed oil) is to be suspected. Bach gives the following table showing the action of strong nitric acid on various oils: Kind of Oil. After Agitation with Nitric Acid. After Heating for Five Minutes. Consistency after Standing Twelve to Eighteen Hours. Olive Pale green ' ' rose White Dirty white Yellowish brown Pale rose Orange-yellow Brownish yellow Orange-yellow Brownish yellow Reddish yellow Reddish Lrown Golden yellow " Solid Peanut. Rape , ., Sesame .................. Liquid Buttery Sunflower Cottonseed ............... Castor. tt * A sample of alleged oli\e oil. purchased in a Massachusetts drug, store and found to be adulterated with cocoanut oil, had the following constants: Specific gravity 0.91 1 Iodine number 74-5 Reichert-Meissl number 2.90 Butro-refractometer at 26° 56.5 SI4 FOOD INSPECTION AND ANALYSIS. The Zeiss Butyro-refractometer furnishes one of the most useful and easily apphed preHminary means of judging the purity of the sample. If the reading is beyond the limits of pure oHve oil, it at once indicates aduheration and often points to the particular adulterant. On the other hand, it is not always safe to assume the oil to be pure if the reading is correct, since mixtures of higher and lower refracting foreign oils may be so skillfully prepared as to read well within the limits of the pure oil on the refractometer scale. The refractometer reading of pure cottonseed oil is almost five degrees higher than that of pure olive. READINGS ON ZEISS REFRACTOMETER OF OLIVE AND COTTONSEED OILS.* Temperature (Centigrade). Scale Reading. Temperature (Centigrade). Scale Reading. Olive Oil. Cottonseed Oil. Olive Oii. Cottonseed OiL 35-0 34-S 34-0 33-5 33-0 32-S 32.0 31-5 31.0 30-5 30.0 29-5 29.0 28.5 28.0 27-5 27.0 26.5 26.0 57-0 57-2 57-4 57-7 58.0 58-3 58-5 59-0 59-2 59-4 59-9 60.1 60.3 60.6 60.9 61. 1 61.5 62.0 62.2 61.8 62.1 62-3 62.5 62.8 63.0 63.2 63.6 64.0 64.2 64 -5 64.9 65.1 65-3 65.7 66.0 66.5 67.0 67-3 25-S 25.0 24-5 24.0 23-5 23.0 22-5 22.0 21.5 21.0 20.5 20.0 19-5 19.0 18. 5 18.0 17-5 17.0 16.5 62.4 63.0 63-3 63.6 63-9 64.2 64-5 64.8 65.1 65-4 ■ 65.7 66.0 66.3 66.6 66.9 67.2 67-5 67.8 68.1 67-5 67.9 68.2 68.5 68.8 69.1 69.4 69.7 70.0 70.3 70.6 70.9 71.2 71-S 71.8 72.1 72.4 72.7 73-0 The Elaidin Test, in the case of pure olive oil, is very distinctive, since it yields by far the hardest elaidin of all the common oils, and solidifies the most quickly. Archbutt f shows the effect on this test of the mixture with olive oil of various proportions of rape and cottonseed oil, as follows : Kind of Oil. Minutes Required for Solid- ification at 25° C. Consistency. 230 320 From 9 to 11^ hours " 9 " 11^ " More than 11^ " Hard but penetrable -1- 1 0% rape oil Buttery •' -1-20% " " " + 10% cottonseed oil " +2o7o " Very soft. i( << ♦ Ann. Rep. Mass. State Bd. of Health, 1899, p. 647. f Jour. Soc. Chem. Ind., 1897, p. 447. EDIBLE OILS AND FATS. 515 Cottonseed Oil as an adulterant is best detected by means of the Hal- phen or Bechi tests. Its presence in notable quantities increases the specific gravity, refractometer reading, and iodine number very materially. Its high Maumene figure is also distinctive. Peanut Oil, when present to a considerable extent, betrays its presence by its pecuhar bean-like flavor. Most of the constants of peanut oil lie within the limits of olive oil, with the exception of the higher iodine number and refractometer reading. A considerable admixture of peanut oil raises the refractometer reading perceptibly over that of pure olive. Its presence is best shown positively by tests for arachidic acid (p. 523), noting that traces of arachin have been reported in pure ohve oil, insuf- ficient, however, to interfere with the detection of added peanut oil. Sesame Oil differs more particularly from olive in its higher specific gravity and iodine and Maumene numbers, and is readily detected by distinctive color tests (p. 519), Rape Oil is characterized by a much lower saponification value and higher iodine number than olive. Com Oil differs materially from olive in its exceedingly high iodine number and refractometer reading. Its specific gravity and saponifica- tion numbers are also higher. Lard Oil, when present in considerable quantity, is often rendered apparent by its characteristic odor on warming. Its low refractometer reading and iodine number are also distinctive. Poppyseed Oil differs most widely from olive oil in its refractometric reading, its high dispersion, and its Maumene number, which in the case of poppyseed is 87° and of olive about 42°. Cocoanut Oil in mixture with olive perceptibly raises the solidifying- point. When more than 12% of cocoanut oil is present, the sample will become solid when placed in ice water. Fish Oils, when present, are rendered apparent by reason of their strong taste and smell, and by their very high iodine number. Boiling the sample with sodium hydroxide develops a peculiar reddish colora- tion, when fish oils are present. Routine Examination of Olive Oil for Adulterants. — First note the smell and taste of the sample, and then take the refractometric reading. An abnormally high refraction indicates adulteration. Then test with strong nitric acid (p. 513). If the refraction is normal, and the color resulting from the acid reaction a pale green, the presumption is that the oil is pure. Test first for cottonseed oil by the Halphen reaction, 5l6 FODD INSPECTION' .4ND AN/iLYSIS. and then in succession try the various color reactions for sesame and rape oils. If all these are absent, and, by abnormal constants, or by color with nitric acid, there is reason to believe the oil is adulterated, determine carefully such of the constants as are most indicative, by their wide variation from olive, of poppyseed, mustard, and corn oils. If all these oils are presumably absent, and either a high refractom- eter reading or a color reaction with nitric acid still indicates adultera- tion, peanut oil is more than likely to be present, and should be tested for either by Renard's or Bellier's method. The edible oils and adulterants are arranged in order of their relative price about as follows: Olive oil, peanut oil, lard oil, sesame oil, poppy- seed oil, rape oil, corn oil, cottonseed oil. COTTONSEED OIL. Source and Preparation. — This oil, largely used as a table oil and as an adulterant of olive oil, is derived from seeds of the various species of the cotton plant, Gosslpiuni, of which the most common are G. herba- ceum, native to Asia, but cultivated extensively in southern Europe and in the United States, G. arboreum, in Asia and Africa, and G. barbadense, in the West Indies. G. religiosum and hirsiituni are varieties of G. herb- aceum. The seeds are in reality a by-product in cotton manufacture. In shape they are irregularly oval, measuring from 5 to 8 mm. greatest diam- eter. The seed skin or pod is covered with the fiber of the cotton. The seeds are first cleaned and separated from dirt by sifting machinei and from the fiber by specially constructed gins, after which they are cut into small pieces, freed from their hulls, crushed between rollers, and afterward submitted to hydraulic pressure in bags to express the oiL which is clarified by filtration or refined. The refining consists in wash- ing the crude oil with sodium hydroxide solution, whereby the impuri- ties are dissolved and thus removed. Nature and Composition of Seeds and Oil. — The seeds of the cotton plant are rich in oil, containing from 10 to 29 per cent, according to the variety. Four samples of American cottonseed were found to be composed as shown in table on top of page 517, according to Brannt.* Refined cottonseed oil is a pale yellow oil of thick consistency, possess- ing a bland though pleasant taste and odor. It consists of the glycerides of oleic, stearic, palmitic, and linoleic acids, and evidently also a small content of hydroxyacids, though this has not been investigated as yet. * Vegetable Fats and Oils, p. 223. EDIBLB OILS AND FATS. 517 Constituents. Water Cottonseed oil Nitrogenous compounds Ammonia-making compounds Gum, sugar, and soluble starch Cellulose, starch, and resin Ligneous tissue Ash (phosphate of lime, silica, alumina, iron, magnesia, potash, soda, etc.) South Carolina. Georgia 1. Georgia II. Georgia III. 9-5 20. 1 17.8 2-3 .8 26.2 17.6 5-7 10. 1 16.2 17-4 2.9 -9 27-4 19.2 5-9 9.8 17. 1 17.2 3-2 -7 26.1 19.8 6.1 8.2 19.6 18. 1 3-7 •9 20.7 22.4 6.4 On cooling the oil to a temperature below 12° C. particles of solid fat will separate. At about 0° to — 5°C. the oil solidifies. When the oil is brought in contact with concentrated sulphuric acid, a dark, red- dish-brown color is instantly produced. U. S. Standards. — -Cottonseed oil is the oil obtained from the seeds of cotton plants and subjected to the usual refining processes; is free from rancidity, has a refractive index (25° C.) not less than 1.4700 and not exceeding 1.4725; and an iodine number not less than 104 and not exceeding no. " Winter-yellow " cottonseed oil is expressed cottonseed oil from which a portion of the stearin has been separated by chilling and pressure, and has an iodine number not less than no and not exceeding 116. Cottonseed Stearin. — This product, used as an adulterant of lard as well as a substitute therefor, is obtained as a by-product in the manu- facture of winter-yellow cottonseed oil. It is a light yellow fat, resembling butter in consistency. Bechi's Silver Nitrate Test. — Hehner^s Modification. — Two grams of silver nitrate are dissolved in 200 cc. of 95% alcohol free from aldehyde, 40 cc. of ether are added, and the reagent made very slightly acid with nitric acid. In applying the test, a small quantity of the melted fat or oil is mixed in a test-tube with half its volume of the above reagent, and the tube is immersed in boiling water for fifteen minutes. With proper precautions the presence of cottonseed oil is indicated by a more or less strong reduc- tion of the silver, while an oil or fat free from cottonseed oil causes no appreciable reduction. Certain oils free from cottonseed that have become rancid or decom- posed, as well as fats that have been subjected to a high temperature, 5l8 FOOD INSPECTION AND ANALYSIS.] sometimes show a slight reduction with Bechi's test. In cases of doubt it is well to apply the test on the fatty acids as follows: MilUau's Modification 0} Bechi's Test* — Heat 20 grams of the sample with 30 cc. of alcohoHc potash solution (20% potassium hydroxide in 70% alcohol), shaking at intervals till saponification is complete. Continue the heating for some minutes afterward until the alcohol is driven off, and dissolve the soap in 250 cc. of hot water. Add a slight excess of 10% sulphuric acid, and wash the separated fatty acids three times by decantation with water. Then proceed with a portion of the fatty acids as in Bechi's test. Halphen's Test. — This is a much more delicate test for cottonseed oil than either of the preceding, as little as 2% of cottonseed oil being rendered apparent in olive oil. A mixture is made of equal volumes of amyl alcohol and carbon bisulphide in which 1% of sulphur has been dissolved. From 3 to 5 cc. of melted fat are mixed with an equal volume of the above reagent in a test-tube, loosely stoppered with cotton, and heated in a bath' of boiling saturated brine for fifteen minutes. If cottonseed oil is present, a deep-red or orange color is produced. In its absence little or no color is developed. Previous heating of the oil diminishes the delicacy of the Halphen test, and Holde and Pelgry t state that if cottonseed oil has been heated at 250° for ten minutes, it will fail to respond to the test. Fulmer finds that it is necessary to heat to 265 to 270° to render it wholly inactive to the test. Gastaldi| finds that it is the pyridin bases in amyl alcohol that render it useful. The test can be made by heating 5 cc. oil, 4 cc. carbon bisul- phide containing 1% of sulphur, and i drop of pyridin for from 15 minutes to one hour in a water-bath. SESAME OIL. Sesame or benne oil is pressed from the seeds of Sesamum indicum and S. orientale, both of which are now regarded as varieties of the same species, and S. radiatiim. These plants are native to southern Asia, but now cultivated in nearly all tropical countries. The larger portion of commercial sesame oil is manufactured in England, France, Germany, and Austria. The seeds are yellow to dark brown, and in some cases black, inclined to the oval in form, the average longest diameter being about 4 mm. * Moniteur Scientifique, 1888, p, 366. t Jour- Soc. Chem. Ind., 18, 1899, p. 711.^ t Chem. Ztg., 35, 1911, p. 688. EDIBLE OILS AND FATS. 519 The seeds are commonly subjected to cold pressure once, and after- wards twice pressed when warm, thus yielding three grades of oil. From 47 to 60 per cent of oil is contained in the seeds. According to Brannt* the composition of sesame seeds is as follows: Sesamum Orientale. Sesamum Indicum. Oil 55-63 30-95 21.42 3-39 7-52 3-9° 50.84 35-25 22.30 3-56 6.85 7.06. Organic substances Protein therein Nitrogen therein Ash Water 100.00 100.00 Sesame oil. consists of the glycerides of oleic, stearic, palmitic, and myristic acids. It is golden yelbw in color, free from odor, and pos- sesses a -delicate and characteristic flavor, on account of which the highest grades are by some considered equal to olive oil as a condiment. It is accordingly sold to some extent as an edible oil. It was formerly used, as an adulterant of olive oil, but has of late years been largely dis- placed by cheaper oils for purposes of adulteration. When cooled to — 3°C., sesame oil congeals to a yellowish- white mass. Concentrated sulphuric acid converts it into a brownish-red jelly. U. S. Standards. — Refractive index (25°) 1.4704 to 1.4717; iodine .number 103 to 112. Adulterants to be looked for in sesame oil are cottonseed, poppy- seed, corn, and rape oils. Tocher's Test.f — One gram of pyrogallic acid is dissolved in 15 cc. of concentrated hydrochloric acid and mixed with 15 cc. of the sample \n a separatory funnel. After standing for a minute, the aqueous solu- tion is withdrawn and boiled. If sesame oil is present, the solution cshowG a red coloration by transmitted, and blue by reflected, light. Baudouin's Test. J — Dissolve o.i gram of cane sugar in 10 cc. of hydro- chloric acid (specific gravity 1.20) in a test-tube, and shake thoroughly with 20 grams of the oil to be tested for one minute. Then allow the niixture to stand. The aqueous solution quickly separates from the oil, find in the presence of 1% or more of sesame oil will be colored deep red. Certain pure Tunisian and Algerian olive oils have been found to iause a slight coloration with this test, but of a different shade from sesame. Moreover, if the test is applied to the fatty acids, no coloration in the case of olive oil is produced, while with sesame the color is the same as with the oil. * Vegetable Fats and Oils, p. 251. f Cham. Zeit. Rep., 5, 1891, p. 15. I Zeits. angew. Chem., 1892, p. 509. 520 FOOD INSPECTION AND ANALYSIS. Villavecchia and Fabris Test.* — This test was suggested on account of the fact that the color reaction in the Baudouin test was attributed to the agency of the levulose produced by the inversion of the sugar by hydrochloric acid. As furfurol is the chief product of the reaction between levulose and hydrochloric acid, it was substituted as follows: Dissolve 2 grams of furfurol in 100 cc. of 95% alcohol, and shake o.i cc. of this solu- tion in a test-tube with 10 cc. of the oil to be tested and 10 cc. of hydro- chloric acid (specific gravity 1.20) for half a minute. The aqueous layer, on settling out, will be colored deep red, if sesame is present. Or 0.1 cc. of the alcohol furfurol solution is mixed with 10 cc. of oil and i cc. of hydrochloric acid in a separatory funnel, shaken well, and the separation aided by the addition of chloroform, which causes the aqueous layer, showing color with sesame oil, to float. Since furfurol produces with hydrochloric acid alone a violet colora- tion, it is necessary to use it in dilute solution as above. RAPE OIL. Rape or colza oil is expressed from the seeds of the Brassica or rape- plant, of which there are three principal varities, Brassica napus, B. cam- pestris, and B. rapa, one or another of which are cultivated in nearly every country of Europe, excepting Greece. Large amounts are also grown in India and China. The seeds are small, round grains, from 2 to 2.5 mm. in diameter, yielding from 30 to 45 per cent of oil. The seeds, according to Brannt,t have the following average composition: ) Fresh Seeds. Old Seeds. Oil 36.80 49-30 2.50 4.80 9.10 38-50 53-25 3-" 3-90 4-35 Organic substances Nitrogen therein Ash Water 100.00 100.00 In the process of preparation the seeds are first crushed, and the oil removed by pressing or extraction. The crude oil is of a brownish- yellow color, and when fresh is almost free from taste and smell, so that it serves, when cold pressed, as an edible oil, or an adulterant of such oils. It develops a disagreeable and peculiar taste and odor on long standing, due to ttie presence of certain albuminous and mucilaginous substances which it contains. These may be removed by refining, usually by treatment with sulphuric acid, but the refined oil has an unpleasant taste and odor. * Jour. Soc. Chem. Ind., 1894, pp. 13-69. t Vegetable Fals aad Oils, p. 240. EDIBLE OILS AND FATS. 521 The principal components of rape oil are the glycerides of stearic, oleic, erucic, and rapic acids. The chief adulterants are cottonseed and poppyseed oils. Palas Test for Rapeseed Oil.* — Mix in the cold 30 cc. of a 1% solu- tion of fuchsin, 20 cc. of sodium bisulphite (specific gravity 1.31), 200 cc. of water, and 5 cc. sulphuric acid. If the sample of oil to be tested be shaken with the reagent, a rose-red coloration is obtained in the presence of rape oil, said to be delicate to the extent of detecting 2% of the oil in mixtures. CORN OR MAIZE OIL. Corn oil is derived from the seed of the American grain Zea mays, or Indian corn, the constitution of the yellow and white varieties of which is, according to Andes,t as follows: Yellow Com, Per Cent. White Corn, Per Cent. Organic matter Starch 82.93 61.9s 10.71 1.32 9-50 6.25 80.76 62.23 9.62 1.04 10.60 7.60 Albuminoids Ash Water Oil 100.00 100.00 Nearly all the oil is contained in the germ of the seed, the oil con^ stituting in fact over 20% of the germ. Corn oil consists chiefly of the glycerides of palmitic and oleic acids. There is some doubt as to the presence of stearin. It is golden yellow in color, and possesses a pleasant odor and taste, resembling in flavor freshly ground grain. It is prepared by subjecting to hydraulic pressure the germ separated in the manufacture of starch and of glucose, the germs yielding about 15% of pure oil. While most of the oil of commerce is a by-product from starch and glucose factories, a small amount is recovered from the residfte of fermentation vats in the manufacture of alcohol. Com oil is coming to be used more and more as an adulterant of olive oil, and, according to Lewkowitsch, of lard. It is claimed by Hopkins,t by Hoppe-Seyler, and others, that com oil, * Analyst, XXII, p. 45. f Vegetable Fats and Oils, p. 131. I Jour. Am. Chem. See, 1898, 20, p. 948. 522 FOOD INjVBCT.ON AND ANALYSIS. unlike most vegetable oils, contains cholesterol. Olive oil was long supposed to be unique as a vegetable oil in containing this substance. Hopkins, on the assumption that cholesterol occurs in corn oil, sug- gested that a test for corn oil as an adulterant of certain vegetable oils lay in the identification of cholesterol. Gill and Tufts * claim that, while the alcohol of com oil is not phytos- terol, neither is it cholesterol, but a third substance, known as sitosterol,! occurring in wheat and rye. There are no color reactions identifying corn oil as such. Its pres- ence in other oils is indicated only by its influence on the various con- stants, the iodine number and refractometric reading especially being much higher than those of other edible oils. PEANUT OIL. Peanut or arachis oil is obtained from the seeds of the Arachis hypo- g(Ba (peanut, ground nut, or earth nut) cultivated in most tropical coun- tries, notably in South America, China, India, and Japan. The plant is a crfeeping herb, developing its blossoms in the axes of the leaves. The fruit buds grow down into the earth, where the fruit is ripened, forming the well-known peanuts of commerce, the composition of which, accord- ing to Brannt, is as follows: Per Cent. Per Cent. Oil 37-48 52.86 27.25 2.43 7-37 to 41-63 " 53-12 27.85 " 2.50 " 2.75 Organic substances Albumin therein. ........ Ash Water 100.00 100.00 Peanut oil is composed chiefly of the glycerides of oleic, palmitic, hypogaeic, and arachidic acids. The oil is extracted by pressure, the first cold-drawn oil being practically colorless, and possessing a pleasant taste suggestive of kidney beans. It is especially adapted for use as a salad or table oil. A second pressure of the moistened residue from the first yields an inferior oil, yellowish in color, also somewhat used for edible purposes, and sometimes commercially called "butterine oil.'* U. S. Standards. — Refractive index (25°) 1.4690 to 1.4707; iodine number 87 to too. * Jour. Am. Chem. See, XXV, 1903. f Burian, Monatsh. Chem., i8, 1897, p. 551. EDIBLE OILS AND FATS. 523 Adulterants of peanut oil are cottonseed, poppyseed, rape, and sesame oils. Ver)^ little pure peanut oil is found in commerce in the United States. It is to be looked for as an adulterant of French and Italian olive oils. Characteristic Tests. — Peanut oil, when pure or nearly pure, may as a rule be readily identified from other oils. When present in large admixture in other oils it is not difficult to detect, but when only a small amount is present, in olive oil for instance, its detection becomes a more troublesome matter. This difficulty arises from the fact that the constants of peanut oil are nearly the same as those of olive, with the single exception of the refractometric reading. Furthermore, there is no readily applied color test identifying peanut oil. All the other common adulterants of olive oil, as cottonseed, sesame, corn, poppyseed, and rape oils, are readily identified, when present in small amounts, either by special color tests, or by reason of the fact that certain of their constants differ very widely from those of olive oil. Much more care and precaution are necessary in dealing with small admixtures of peanut oil than with almost any other adulterant. The Renard Test* has long been in use for detecting and estimating peanut oil in mixtures. In its original form this test did not give entirely satisfactory results, and earlier led to some erroneous conclusions. In recent years, however, it has been so modified and improved as to be capable of quite positive results when carefully carried out. While arachin is said to occur in minute traces in olive oil, its presence is not sufficiently marked to interfere with the use of the Renard method in detecting any decided admixture of peanut oil. The following modification of the Renard method, devised by Tolman,t h^s been adopted by the A. O. A. C: Twenty grams of the oil are saponified in a 250-cc. Erlcnmeyer flask with 200 cc. of alcoholic potassium hydroxide (40 grams potassium hydroxide in i liter of 95% redistilled alcohol). Neutrahze with dilute acetic acid, using phenolphthalein as an indicator, and wash into a 500-cc. flask containing a boiling mixture of 100 cc. water and 120 cc. 20% solution of lead acetate. Boil for a minute and cool the contents of the flask by immersing in cold, or, preferably, ice water, whirling the flask occasionally so that * Comp. Rend., 73, 1871, p. 1330. t U. S. Dept. of Agric, Bur. of Chem., Bui. 65; also Bui. 77, and Bui. 107 (rev.). 524 FOOD INSPECTION AND ANALYSIS. the soap when cold adheres to the sides of the flask. The water and excess of lead acetate can then be poured out, leaving the soap in the flask. Wash by shaking and decantation, first with cold water and then with 90% alcohol. Add 200 cc. of ether, cork the flask, and allow to stand with occasional shaking till the soap is disintegrated, after which boil on a water-bath under a reflux condenser for five minutes. Cool the soap solution down to a temperature between 15° and 17°, and allow it to stand for about twelve hours. Filter and thoroughly wash the precipitate with ether, after which the soap in the filter is washed back into the original flask with a stream of hot water acidulated with hydrochloric acid. Add an excess of dilute hydrochloric acid, partially fill the flask with hot water, and heat until fatty acids form a clear oily layer. Fifl the flask with hot water, allow the fatty acids to harden and separate from the precipitated lead chloride, wash, drain, repeat washing with hot water, and dissolve the fatty acids in 100 cc. of boiling 90% by volume alcohol. Cool to 15° C, shaking thoroughly to aid crystallization. From ^ to 10 per cent of peanut oil can be detected by this method, as it effects a complete separation of the soluble acids from the insoluble, which interfere with the crystallization of the arachidic acid. Filter, wash the precipitate twice with 10 cc. of 90% alcohol, and then with 70% alcohol. Finally dissolve off the precipitate with boiling absolute alcohol, evaporate to dryness in a tared dish, dry and weigh. To the weight add 0,0025 gram for each 10 cc. of 90% alcohol used in the crystallization and washing, if done at 15° C, and 0.0045 g^am for each 10 cc. if done at 20°. The approximate amount of peanut oil is found b}^ multiplying the weight of arachidic acid by 20. Arachidic acid crystals thus obtained should be examined micro- scopically. The melting-point should he between 71° and 72° C. Methods of J. Bellier.* — Qualitative Test. — Saponify i gram of the oil with 5 cc. of an alcoholic potash solution containing 85 grams po- tassium hydroxide per Hter of strong alcohol, conducting the saponi- fication in a small Erlenmeyer flask on the water-bath. After saponi- fication, boil for two minutes, neutralize with dilute acetic acid, using phenolphthalein as an indicator, and cool by setting the flask in water at a temperature of from 17° to 19°. After a short time, a precipitate nearly always comes down. Then add to the solution 50 cc. of 70% alcohol, containing 1% by volume of strong hydrochloric acid (specific * Ann. Chim. Anal., 1899, 4, p. 49; Zeits. fiir untersuch. Nahr., 1899, 2, p. 726. EDIBLE OILS AND FATS. 525 gravity 1.20). Cork the flask, shake vigorously, and again cool by setting the flask in the above cooling-bath. In the absence of a precipitate, the oil may be pronounced free from peanut. If 10% or more of peanut oil is present, a more or less characteristic precipitate forms, and often with less than 10% a cloudiness in the solution is perceptible after standing between 17° and 19° for half an hour. Pure oHve oil remains perfectly clear as a rule. x\ few varieties of olive oil from Tunis especially high in solid fat acids, as well as cottonseed oil and sesame oil, give similar turbidity on the addition of the 70% alcohol. To distinguish between these oils and peanut oil, heat the mixture on the water-bath till complete solution takes place, and again cool to 17° to 19°. In the case of peanut oil the cloudiness or precipitate again occurs to the same extent as before, while in the other cases the solution should remain clear or nearly so. Quantitative Determination. — Saponify 5 grams of the oil with 25 cc. of the above alcoholic potash solution in a 250-cc. Erlenmeyer flask neutralize exactly with acetic acid, and cool quickly in water. After standing an hour, pour upon a 9-cc. filter and wash the precipitate with 70% alcohol containing 18% by volume of hydrochloric acid, the tem- perature of the solution being not less than 16° nor more than 20°. Con- tinue the washing till the wash water no longer shows turbidity when diluted with water. Dissolve the precipitate in 25 to 30 cc. of hot 95% alcohol, dilute with water until the alcohol is 70%, let stand in water at 20°, filter, wash with 70% alcohol, dry at 100°, and weigh. Bellier states that he has recognized with certainty as small an admix- ture as 2% of peanut oil by this method. MUSTARD OIL. The fixed oil of mustard is a by-product expressed from the seeds of the black and white mustard {Sinapis nigra and S. alba) in the process of preparation of mustard flour as a spice. The seeds contain from 25 to 35 per cent of oil. Mustard oil somewhat resembles rape in composition, containing glycerides of erucic, behenic, and probably rapic acid. Black mustard oil is brownish yellow in color, having a mild flavor, and an odor but sHghtly suggestive of mustard. White mustard oil is golden yellow, and has a somewhat sharp taste. 526 FOOD INSPECTION AND ANALYSIS. Mustard oil is an alleged adulterant of edible oils, though by no means a common one. POPPYSEED OIL. This oil is obtained from the seeds of the opium poppy {Papaver somniferum), native in the countries east of the Mediterranean, and cul- tivated extensively for opium and for oil in all parts of Europe, Asiatic Turkey, Persia, Egypt, India, and China. Most of the oil of commerce comes from France and Germany. There are two chief varieties of poppy, the black {P. nigrum) and the white (P. album), the finest oil being produced from the white. The seeds are somewhat flattened in form and kidney-shaped, yielding from 40 to 60 per cent of oil. According to Brannt the seeds have the follow- ing composition: White Poppy- seed. Black Poppy- seed. Oil 55.62 32.11 16.89 3-42 8.8s 100.00 51-36 35-14 17-50 4.00 9-50 Organic substances Protein therein Ash Water 100.00 The oil is obtained by crushing the seeds and applying pressure. The best grade of cold-drawn oil is pale yellow in color, possessing a pleasant taste when fresh, and being practically free from odor. Lower grades shade into deeper yellow and even reddish color, possessing a strong taste and odor. Poppyseed oil is much used in Europe as a table oil, and does not readily turn rancid. It is composed of the glycerides of stearic, palmitic, and linoleic acids. Poppyseed oil has been used to some extent as an aduherant of olive oil. It is itself not infrequently aduher- ated with sesame oil. SUNFLOWER OIL. Sunflower oil is derived from the seed kernels of the plant of the same name {Helianthus annuus), originally grown in Mexico, but now culti- vated most extensively on a commercial scale in southern Russia. EDIBLE OILS /1ND F/1TS. 527 According to S. M. Babcock * the composition of sunflower seeds is as follows: Air-dry. Dried. Water 12.68 3.00 15.88 2Q.21 18.71 20.52 3-43 18.19 33-45 21-43 23-50 Ash Albuminoids (N X 6.25) Crude fiber Nitrogen-free extract Fat (ether extract) 100.00 100.00 The seeds are long, black, and oval in shape, yielding from 18 to 28 per cent of oil. The liquid fatty acids of sunflower oil consist for the most part of linoleic, but little oleic acid being found. The -seeds are first shelled, then crushed, and finally submitted to pressure both cold and hot. Sunflower oil is pale yeflow in color, has a mild, pleasant taste, and is nearly free from odor. The cold-drawn oil is the variety most used for edible and culinary purposes in Russia, and as an adukerant of olive oil. Its use as an adulterant is, however, limited, and the writer has no knowledge of its having been found in olive oils used in the United States. ROSIN OIL. Rosin oil is prepared by the distillation of common rosin, and is an alleged adulterant of olive oil. It may be detected when present by shaking i to 2 cc. of the sample with acetic anhydride while warming. Cool, remove the anhydride by a pipette, and add a drop of sulphuric acid (specific gravity 1.53). Rosin oil gives a fugitive-violet color.f Cholesterol also responds to this color reaction. Renard's Test for Rosin Oil. — Prepare a solution of stannic bromide by allowing dry bromine to fall drop by drop upon tin in a dry, cool flask, and dissolving the product in carbon bisulphide. Add a drop of this reagent to i cc. of the oil. In presence of rosin oil a violet color will be produced. Polarization Test for Rosin Oil.f — The oil is dissolved in definite proportion in petroleum ether, and polarized in a 200-mm. tube. Rosin * The Sunflower Plant, its Cultivation, Composition, and Uses. U. S. Dept. of Agric, Div. of Chem., Bui. 60, p. 18. t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 32. 528 FOOD INSPECTION ^ND /IN A LYSIS. oil polarizes from + 30 to + 40 on the cane sugar scale, while other oils have a reading between + 1 and — i. COCOANUT OIL, Cocoanut oil is the fat expressed from the kernels of the cocoanut or fruit of the cocoa palm (Cocos nucijera), indigenous to the South Sea Islands and to the East-Indian archipelago, but grown in many tropical covmtries. It is sometimes known as "copra oil," from the copra or pulp, which contains from 60 to 70 per cent, of fat. According to Brannt, the com- position of the pulp is as follows: Oil Organic substances Albuminous substances Ash Water Indian Copra. 68.75 23-65 1-45 6.15 9.16 African Copra. 66.80 25-25 1.50 6.45 In the preparation of the oil the moist copra is separated from the shell, crushed in mortars and subjected to pressure, yielding a milky mass. This is then heated in boilers and the oil removed by skimming. In some localities the pulp is first dried and then pressed. Cocoanut oil is usually white and possesses a mild taste and pleasant odor. The oil easily becomes rancid but is seldom adulterated. The cold- drawn Malabar oil is of greenish color and is used by the natives as an edible oil or substitute for butter. This variety is seldom found in commerce. Tne oil contains, besides palmitin and olein, large proportions of myristin and laurin. Unlike the other vegetable oils, it contains also notaljle quantities of the glycerides of the volatile fatty acids caproic, capric, and caprylic, hence the high saponification value and Reichert number. The most characteristic constant is the Polenske number. The iodine number (8-9.5) is strikingly low, although oil from the rind, according to Richardson,* runs as high as 40. According to Andes, crystals of cocoanut oil appear under the micro- scope as a thick network of long needles. * Jour. Ind. Eng. Chem., 3, 191 1, p. 574. EDIBLE OILS /iND FATS. 529 COCOA (CACAO) BUTTER. This preparation is not, properly speaking, in itself an edible fat. It is a by-product in the manufacture of cocoa, being removed by pressure from the crushed and ground cocoa nibs. The fat in cocoa beans varies from 36 to 50 per cent. The expressed fat is yellowish white, of a tallow- like consistency, has a pleasant taste and an odor suggestive of chocolate. It keeps a long time without turning rancid. In composition it consists of the glycerides of stearic, palmitic, and lauric acids, with traces of the glycerides of arachidic and butyric acids. Its demand for pharmaceutical purposes is, however, sufficiently great to render the use of cocoa-butter as an adulterant of food-fats extremely rare. It should be borne in mind as a possible adulterant in examining various 'oils. It is subject to adulteration with paraffin, tallow, and cottonseed stearin. TALLOW. The rendered fats of various animals, especially the cow and sheep, constitute what is generally known as tallow. The untreated fatty tis- sues are more properly known as suet, the tallow being the clear fat separated entirely by heat from the cellular material. Tallow consists almost entirely of olein, palmitin, and stearin. Mut- ton tallow is usually, but not always, harder than beef tallow. Excepting in the manufacture of material for oleomargarine,- wherein the heart and caul fats of beef are almost exclusively used, the fats from different parts of the animal are not, as a rule, separated. Fresh tallow has very little free fatty acid, but when it becomes rancid, the fat contains sometimes as high as 12% of free acid, reckoned as oleic. Tallow is of chief interest to the food analyst in connection with its use as an adulterant of lard. BUTTER. Nature and Composition. — Butter is the product obtained by the churning of cream or milk, whereby the fat particles are caused to adhere together into a compact mass, inclosing a certain portion of the casein, the excess of milk serum being subsequently largely removed by washing and mechanical working. 530 FOOD INSPECTION /IND ANALYSIS. Butter fat is of extremely complex composition, containing a larger variety of glycerides than any other fat. Besides olcin, palmitin, and stearin, the usual glycerides of the insoluble or fixed fatty acids found in most fats, butter contains notable quantities of the glycerides of a number of the volatile fatty acids, chief among which are butyrin, caproin, caprin, and caprylin, to which are due its distinctive taste, and which by exposure to light and air readily become decomposed into their fatty acids — butyric, caproic, capric, and caprylic, respectively. This decom- position in butter causes, or, more properly speaking, accompanies, what is commonly known as "rancidity." The process of separation of butter fat into its component glycerides is a matter of extreme difficulty, and results obtained by different chemists vary widely. Separation has been attempted by fractional distillation, by methods depending on the difference in chemical affinity of the various acids, and on the difference in solubility of the various lower homo- logues in. water at different temperatures.* According to Browne, the composition of butter fat is as follows: Acid Dioxvstearic. . Oleic Stearic Palmitic Myristic Laurie Capric Caprylic Caproic Butyric Totals Percentage of Acid. Percentage of Triglycerides. 32-50 1.83 38.61 9.89 2-57 0.32 0.49 2.09 5-45 94-75 1.04 33-95 1. 91 40.51 10.44 2-73 0-34 0-53 2.32 6-23 100. CO Upwards of 300 analyses of butter are summarized by Konig in the following table: Water, Per Cent. Fat, Per Cent. Casein, Per Cent. Milk, Per Cent. Sugar, Per Cent. Lactic Acid, Per Cent. Salts, Per Cent. Minimum Maximum 4-15 35-15 13-59 69.96 86.15 84-39 0.19 4.78 0.74 0.50 0-45 1. 16 0.12 0.02 15.08 0.66 * Browne, A Contribution to the Chemistry of Butter Fat, Jour. Am. Chem. Soc, 21, 1899, p. 807. EDIBLE OILS AND FATS. 531 Effects of Feeding Oil Cakes on the Composition of Butter. — Experi- ments have shown that the substance which causes cottonseed oil to respond to the Halphen test passes into the milk fat on feeding cows with cottonseed cake, but the substance that gives the Baudouin reaction is never carried into the milk on feeding with sesame cake. A number of investigators have found that feeding with cocoanut cake raises somewhat the Polenske number of the milk fat. There is good evidence, however, that, while the addition of vegetable oils to butter introduces phytosterol, as detected by Bomer's phytosterol acetate test, this substance can not be introduced into the milk fat by feeding. These facts should be borne in mind in the examination of butter for foreign fats. ANALYSIS OF BUTTER. Preparation of the Sample. — A. O. A. C. Method* — If large quan- tities of butter are to be sampled, a butter-trier or sampler may be used. The portions thus drawn, about 500 grams, are to be perfectly melted in a closed vessel at as low a temperature as possible, and when melted, the whole is to be shaken violently for some minutes till the mass is homo- geneous, and sufficiently solidified to prevent the separation of the water and fat. A portion is then poured into the vessel from which it is to be weighed for analysis, and should nearly or quite fill it. This sample should be kept in a cold place till analyzed. Water.— /I. O. A. C. Method. — About two grams of the sample are weighed in a flat-bottomed platinum dish, such as is used for determining water in milk, and the dish and its contents kept in contact with the live stream of a water-bath till a constant weight is attained. Patrick's Rapid Method. f — This method is especially suited for the use of dairymen, inspectors and others not provided with laboratory facilities. Ten grams of the thoroughly mixed butter are weighed into a 250-cc. aluminium beaker, which, together with a glass rod has been previously tared, and boiled over (but not in) the flame of an alcohol lamp provided with a conical asbestos chimney, holding the beaker by means of a wire clamp in a nearly horizontal position to avoid loss from spattering or foaming, and whirling constantly to prevent overheating. The rod serves to break up lumps of curd which form, thus facilitating the drying. * U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 43; Bui. 107 (rev.), p. 123. t Jour. Am. Chem. Soc, 28, 1906, p. 161 1; 29, 1907, p. 11 26. 532 FOOD INSPECTION AND ANALYSIS. The heating should be so conducted as to avoid any considerable dis- coloration of the curd. With suit- able heating the water may be re- moved in less than 15 minutes, after which the beaker is cooled in water and weighed, A balance sensitive to 10 milligrams, such as is used in w^eighing cream for testing by the Babcock method, is sufficiently accurate for weighing the butter. Grays Method.'^ — i. The Spe- cial Apparatus for this method, shown in Fig. 100, consists of a flask {A) connected by a close-fitting rubber stopper {B) with a gradu- ated tube (C), and this in turn with a condenser jacket (£) by a rubber stopper {D). The tube C is closed by a glass stopper, the zero mark being the end of the stopper. Each mark of the grad- uation represents 0.02 cc. or, when 10 grams of butter are used, 0.2%. 2. Process. — Weigh 10 grams of the well mixed butter on a piece of parchment paper 13 cm. square, introduce into the flask, and add 6 cc. of a mixture of 5 parts of amyl acetate and i part of amyl valerianate, free from water-soluble impurities. Connect the apparatus as shown in Fig. 100, fill the condenser jacket with cool water to within 2.5 cm. of the top, and remove the glass stopper F. Heat the flask over a Bunsen burner, thus melting the butter and boiling the water. Watch the con- FlG. 100. — Gray's Apparatus for the Rapid Determination of Water in Butter. * U. S. Dept. of Agric, Bur. of Animal Ind., Circ. lOO. EDIBLE OILS AND FATS. 533 densation of the steam in the graduated part of the tube C, and do not allow the steam to get higher than the 15% mark. In case of continued foaming, allow the mixture to cool, add 2 cc. of the amyl reagent, and continue heating. After the water in the sample has boiled out, the temperature rises and the amyl reagent boils, driving the last traces of water and water-vapor from the flask and bottom of the stopper. Some of the amyl reagent is carried into the tube C with the steam, and some is boiled over after the water has been driven off. This amyl reagent in the tube is no disadvantage. When the mixture in the flask becomes a brown color and all the crackling noises in boiling cease, which usually requires 5 to 8 minutes, it is safe to conclude that all water has been driven from the flask. Disconnect the flask A from the stopper B, place the glass stopper F in the tube.C, giving it a turn to insure its being held firmly; invert the tube C, first being sure that the mouth of the small tube inside the bulb is held upwards, pour the water from the condensing jacket £, and remove the jacket. When the tube C is inverted, the water and reagent flow into the graduated part of the tube. To separate these and to get the last traces of water down into the graduated part, the tube C is held with the bulb in the palm of the hand, and the stoppered end away from the body, raised to a horizontal position, and swung at arm's length sharply downward to the side. This is repeated a number of times until the dividing line between the water and reagent is very distinct, and no reagent can be seen with the water or vice versa. The tube should then be held a short time with the stoppered end downward, and the amyl reagent in the bulb agitated in order to rinse down any adhering water. ' The reading should not be taken until the tube and contents have cooled so httle warmth is felt. When 10 grams of butter are used, the percentage is read directly at the lower meniscus. With butter very low in moisture it may be desirable to use 15 grams, and with butter very high, 5 grams. Fat. — This may be determined either directly or indirectly. For the direct determination, a weighed amount of the sample, from 2 to 3 grams, is first dried at 100° in sand or asbestos, contained in a thin and fragile round-bottomed evaporating-shell (Hoffmeister's Schalchen). If desired, the moisture may be determined in this connection by loss in weight after drying. The shell is afterwards inclosed in a piece of fat-free filter-paper, and crushed in pieces between the fingers in such a manner as to avoid loss. The pieces are gathered in a mass and folded together 534 FOOD INSPECTION AND ANALYSIS. in the filter-paper to form a packet of a size readily transferable to a Soxhlet extractor, in which the fat is removed in the usual manner and weighed, after drying, in a tared flask. Or, the fat may be indirectly determined by subtracting the sum of the water, casein, and ash from loo. Casein. — The residue from the determination of water by the A .O. A. C. method is stirred with petroleum ether until the fat is dissolved, and transferred to a tared Gooch crucible. After thorough washing with petroleum ether, the crucible is dried at ioo°, cooled, and weighed, thus obtaining the casein and ash. The loss on ignition at a dull red heat represents the casein. If desired nitrogen may be determined in the residue after removal of the fat with petroleum ether, and casein calculated from the nitrogen, using the factor 6.37. Ash. — The residue left on the Gooch crucible after ignition, obtained as described in the preceding section is the ash. It consists largely of salt, which may be calculated from the percentage of chlorine determined by titration. Milk Sugar and Lactic Acid compose most of the undetermined matter remaining after deducting from the total solids the sum of the fat, casein, and ash. Determine milk sugar, if desired, in an aqueous extract of the butter by Fehhng's solution. Determination of Salt. — In a tared dish or beaker weigh out about 5 grams of butter, taking a gram or so at a time from different parts of the sample. Add hot water to the weighed part, and after it has melted, the contents of the dish are poured into a separatory funnel, shaken and allowed to stand till the fat collects at the top, after which the underlying aqueous solution is drawn off into an Erlenmeyer flask, leaving the fat in the funnel bulb. Hot water is again added, and from ten to fifteen extractions are made, using about 20 cc. of water each time, all the water being collected in the Erlenmeyer flask. A few drops of a solution of potassium chromate are then added for an indicator, and the sodium chloride volu metrically determined by a standard silver nitrate solution. Salted butter contains from 0.5 to 6% of salt. Examination of Butter Fat. — ^The butter fat is best obtained free from curd and salt by filtering when hot, the sample being best melted in a beaker on the water-bath. The water, with the curd and salt, will settle to the bottom. The clear fat is then filtered at a temperature not EDIBLE OILS AND FATS. 535 exceeding 50° C, and subjected to such examination as may be desired to determine its purity. U. S. Standard Butter Fat has a Reichert-Meissl number not Ies« 40° than 24 and a specific gravity not less than 0.905 at — 5 C. 40 ADULTERATION OF BUTTER. The artificial coloring of butter is an art practiced for so many years, and is so far in accord with the popular demand, that it can hardly be considered as an adulteration. The most recent custom of adding pre- servatives other than salt to butter is, however, very properly considered in most localities as reprehensible, unless the character and amount of the preservative be made clear to the purchaser by a suitable label. The most common and time-honored sophistication is the substitu- tion in whole or in part of foreign fat, as in the case of oleomargarine, and, more recently, in the fraudulent sale of renovated or process butter for the freshly made article. U. S. Standard Butter is butter containing not less than 82.5% of butter fat. By acts of Congress approved August 2, 1886, and May 9, 1902, butter may also contain added coloring matter. Artificial Coloring Matter in Butter.— Formerly carrot juice and annatto were used almost entirely as butter colors. The carrot furnished to the farmer a, ready means of coloring his dairy butter, and its use was long in vogue for this purpose, before the commercial butter colors were available. Other vegetable colors, such as turmeric, marigold, saffron, and safilower, are r^aid to have been used for this purpose, but, with the possible exception of turmeric, the writer is not aware of authentic cases in which they have been found in recent years. While annatto as a butter cclor is still in use, it is rapidly giving place to various oil-soluble, azo coal- tar colors, which are admirably adapted to the purpose. All butter colcrs are now put on the market in solution in oil, usually cottonseed in this country and sesame in Europe. Detection. — Martin^ devised a general scheme, applicable for the detection of various colors in butter. His reagent consists of a mixture of 2 parts of carbon bisulphide with 1 5 parts of ethyl or methyl alcohol. 25 cc. of this solution are shaken with about 5 grams of the butter to be tested, and, after standing for some minutes, the mixture separates into two layers, of * Analyst, 12, p. 70. 53^ FOOD INSPECTION AND ANALYSIS. which the lower consists of the fat in solution in the carbon bisulphide, while the upper is the alcohol, which dissolves out and is colored by the artificial dye employed. If saffron is present, the alcohoHc extract will be colored green by nitric acid and red by hydrochloric acid and sugar. Coal-tar dyes, if present, may be fixed on silk or wool by boiling bits of the fiber in the alcoholic extract, diluted with water and acidulated with hydrochloric acid. Turmeric is to be suspected, if ammonia turns the alcoholic extract brown; marigold, if silver nitrate turns it black, and annallo, if on evapo- rating the alcoholic solution to dryness and applying to the residue a drop of concentrated sulphuric acid, a greenish-blue coloration is produced. Turmeric is further tested for in the residue from the alcoholic extract as above obtained, by boiling the residue in a few cubic centimeters of a dilute solution of boric acid (or a solution of borax acidulated with hydrochloric acid), and soaking a strip of filter-paper therein. On drying the paper, if it assumes a cherry-red color, turning dark olive by dilute alkali, the presence of turmeric is assured. Carrotin (the coloring matter of the carrot root) does not impart its color to the alcohol layer in Martin's test. Moore * has pointed out this exception, and showm that while with carrotin present the alcohol layer in Martin's test remains colorless, as in the case of uncolored butter, that when, however, a drop of very dilute ferric chloride is added, and the test-tube shaken, if carrotin be present, the alcohol will gradually absorb the yellow color from the butter. Care must be taken to avoid an excess of ferric chloride, as very little of this reagent will suffice. Allen states that a butter color commercially known as "carrotin" consists in reality of i part of annatto in 4 parts of oil. Detection of Annatto in Butter. — Treat 2 or 3 grams of the melted and filtered fat (freed from salt and water) with warm, dilute sodium hydroxide. After stirring, pour the mixture while warm upon a wet filter, using to advantage a hot funnel. If annatto is present, the filter will absorb the color, so that, when the fat is washed off by a gentle stream of water, the paper will be dyed straw color. It is well to pass the warm alkaline filtrate two or three times through the fat on the filter to insure removal of the color. If, after drying the filter, the color turns pink on application of a drop of stannous chloride solution, annatto is assured. * Analyst, ii, p 163. EDIBLE OILS AND FATS. 537 Detection of Coal-tar Colors in Butter. — Gelsler's Method* — A few- drops of the clarified fat are spread out on a porcelain surface and a pinch of fullers' earth added. In the presence of various azo-colors, a pink to violet-red coloration v^ill be produced in a few minutes. Some varieties of fullers' earth react much more readily with the azo-dyes than "do others. In fact some do not respond at all. When once a satisfactory sample of this reagent is obtained, a large stock should be secured of the same variety. Low's Method.^ — ^A small amount of material to be tested is melted in a test-tube, an equal volume of a mixture of i part of concentrated sulphuric acid and 4 parts of glacial acetic acid are added, and the tube is heated nearly to the boiling-point, the contents being thoroughly mixed by shaking; the tubes are set aside, and after the acid solution has settled out it will have been colored wine-red in the presence of azo-color, while with pure butter fat, comparatively no color will be produced. Doolittle's Method for Azo-colors and Annatto.J — ^The meked sample is first filtered. Two test-tubes are taken and into each are poured about 2 grams of the filtered fat, which is dissolved in ether. Into one test- tube are poured i or 2 cc. of dilute hydrochloric acid, and into the other about the same volume of dilute potassium hydroxide solution. Both tubes are well shaken and allowed to stand. In the presence of azo- dye, the test-tube to which the acid has been added will show a pink to wine-red coloration, while the potash solution in the other tube will show no color. If annatto has been used, on the other hand, the potash solution will be colored yellow, while no color will be apparent in the acid solution. Cornelison's Test for Artificial Colors. § — Melt 10 grams of the clear, dry fat, and shake well in a separatory funnel with 10 to 20 grams of 99.5% acetic acid. If the materials are too hot, the fat will dissolve, but at about 35° it separates quickly and almost completely. Draw off the clear acid, and after noting its color, test by adding to one portion of 5 cc. a few- drops of concentrated nitric acid, and to another portion a few drops of concentrated sulphuric acid. Natural yellow butter gives by this test a colorless extract, which remains colorless on adding nitric or sulphuric acid. The acid extracts of annatto, curcumin, and carrot are various shades of yellow, both before * Jour. Am. Chem. Soc, 20, 1898, p. 110. t Ibid., 20, p. 889. I U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 152. § Jour. Am. Chem. Soc, 30, 1908, p. 1478. 538 FOOD INSPECTION AND ANALYSIS. and after addition of nitric acid, while with sulphuric acid they take on a pink coloration on standing, which in the case of curcumin is very decided. Soudan I and butter yellow give pink extracts, which remain pink on adding the stronger acids, while cerasine orange G, yellow O.B., yellow A.B. and certain other coal-tar dyes give extracts of various shades of yellow, which on treatment with the heavy acids in some cases remain colorless, but in others become pink, while the oil globule which separates remains colorless or takes on a pinkish color according to the dye. PRESERVATIVES AND THEIR DETECTION. — Fresh or unsalted butter and renovated butter are often found with an added preservative, the one most commonly used for this purpose being the so-called " boric mixture " (borax and boric acid) already discussed under milk adultera- tion. Salted butter is occasionally, though not so often, found preserved. Other preservatives used in butter are formaldehyde, and salicylic and sulphurous acids. These latter are, however, rarely found. Boric Acid. — This, if present, is best detected in the aqueous solution that settles to the bottom when butter is melted at the temperature of the boiling water bath, the supernatant fat being decanted off. Richmond* claims to be able to distinguish free boric acid from borax as follows: If on applying turmeric-paper directly to the aqueous liquid the paper turns red, the color being especially evident on drying, free boric acid is indicated. As a confirmatory test the reddened turmeric- paper is treated with dilute caustic alkali, whereupon it turns a dark olive- green if boric acid is present. In the absence of a red color by the above test, or when this color is faint, the aqueous solution is acidified slightly with hydrochloric acid and the turmeric-paper applied as before. If borax be present to an appreciable extent, the red color will now be quite marked, even though not appearing before. In other words, testing with turmeric-paper with- out acidifying with hydrochloric acid shows, according to Richmond, a slight coloration due to the free acid alone, while the more intense color formed by first acidifying is due to the combined acid or borax. Determination oj Boric Acid. — ^Ten grams of the butter fat are weighed in a beaker and transferred with hot water to a separatory funnel in which the fat is extracted with lo to 15 portions of hot water as described on page 534- The combined aqueous extract is evaporated to dryness in a platinum dish, the residue made alkaline, and ignited at * Dairy Chemistry, p. 254. EDIBLE OILS AND FATS. 539 a dull red heat. Boil the ash with water, filter, and wash with hot water, keeping the volume of the filtrate under 60 cc. Make sure that the solu- tion is perfectly neutral to methyl orange by treatment, if necessar}^, with sulphuric acid and tenth-normal alkali, add 30 cc. of glycerin, a few drops of the phenolphthalein indicator, make up to 100 cc, and titrate with tenth-normal sodium hydroxide according to Thompson's method (p. 829). Butter being practically free from phosphates, the preliminary treat- ment for removing phosphoric acid in Thompson's method may be omitted. Formaldehyde. — The aqueous solution from which the fat of the butter melted at low temperature has been poured off, is added to some milk previously found free from formaldehyde, and the test for the latter with hydrochloric acid and ferric chloride is tried directly in the milk. Salicylic Acid. — Detection. — See method No. 2 for detection in milk, page 183. Determination of Salicylic Acid. — Method oj the Paris Municipal Laboratory. — Repeatedly exhaust 20 grams of butter in a separatory funnel with a solution of sodium bicarbonate, thus obtaining soluble sodium salicylate, if salicylic acid be present. Acidulate the aqueous extract with dilute sulphuric acid, and extract with ether. Evaporate the ether, and to the residue add a little mercuric nitrate, forming a pre- cipitate nearly insoluble in water. Filter this off, wash the precipitate with water, and decompose into free salicylic acid with dilute sulphuric acid. Redissolve in ether, evaporate the solvent as before, and drj' the residue at a temperature of 80° to 100°. Extract the residue with petroleum ether, dilute the ethereal liquid vvdth an equal volume of 95% alcohol, and titrate with tenth-normal alkali, using phenolphthalein as an indicator. I cc. of tenth-normal alkali =0.0138 gram sahcylic acid. Sulphurous Acid. — The aqueous liquid, separated from the butter fat, is distilled, and the distillate treated with bromine water and barium chloride. A precipitate on the addition of the latter reagent indicates the presence of sulphurous acid or a sulphite in the butter. Glucose in Butter.* — Crampton states that glucose has been found by him in butter intended for export to tropical countries, added to pre- ' ■ i * Jour. Am. Chem. Soc, 20, 1898, p. 201. 540 FOOD INSPECTION /IND AN /I LYSIS. vent decomposition. In one sample made for export to Guadeloupe he found over io% of glucose. For its detection or estimation lo grams of the sample are weighed out and transferred to a separatory funnel with hot water, and shaken out with successive portions of hot water. These are combined, and the aqueous extract made up to 250 cc. The reducing sugar may be determined by Fehling's solution or by polarization, using in the latter case alumina cream as a clarifier. While a slight reduction should be disregarded, any considerable reduction may be undoubtedly ascribed to glucose. BUTTER "FILLED" WITH WATER.— Various preparations have been placed on the market to aid in incorporating water with butter. So called " black pepsin " has been used for this purpose. By churning the butter with water and a certain amount of the preparation in such a manner as to destroy the grain, it is possible to introduce two or three times the normal amount of water. RENOVATED OR PROCESS BUTTER. This product is also variously termed " boiled," " aerated," and " sterilized " butter. There are various modifications of the process of manufacture, but the object is to melt up and treat rancid butter in such a manner that for a time at least it is sweet. The following manner of treatment is typical, and shows in the main the necessary steps in carrying out the process, though details of manipulation vary in different localities. The butter is melted in large tanks surrounded with hot water jackets at a temperature varying from 40° to 45° C. By this means the curd and brine settle to the bottom, whence they are drawn off, while the lighter particles rise to the top in the form of a froth or scum and are removed by skimming. The clear butter fat is then, as a rule, removed to other jacketed tanks, and, while still in a molten condition, air is blown through it, which removes the disagreeable odors. The melted fat is then churned with an admixture of milk (more often skimmed) till a perfect emulsion is formed, after which it is rapidly chilled by running into ice cold water, with the result that it becomes granular in form. It is then drained and " ripened " for some hours, after which it is worked free from excess of milk and water, salted, and packed. Under some state laws this product, to be legally sold, must conform to rules of labeling as strict as those prescribed for oleomargarine. In EDIBLE OILS /1ND F/iTS. . 541 Other localities it may be sold with impunity. Not infrequently it is sold as choice creamery butter, and sometimes at the same price. U. S. Standard Renovated or Process Butter should contain not more than 16% of water, and at least 82.5% of butter fat. OLEOMARGARINE. According to the U. S. revenue laws, artificial butter composed wholly or in part of fat other than butter fat must be branded oleomargarine. The name butterine, although used in advertising matter, does not have the sanction of the government. The product is commonly known in England as margarine. As a rule the oleomargarine of commerce is composed of retined oleo oil, usually churned up with neutral lard, milk, and a small amount of pure butter, the whole being salted and sometimes colored to resemble butter. Cottonseed oil and other vegetable oils are also used to some extent. Oleo oil is prepared from the fat of beef cattle somewhat as follows:* Immediately after the animals are killed the fresh intestinal and caul fat are removed and placed in tanks of water at a temperature of about 80° F. From this water they are transferred to other tanks of cold water and chilled until all animal heat is removed. The fat is then cut or hashed into small pieces and melted at about 150° F. in jacketed steam kettles, until the clear oil is separated from the connective tissue. This oil is then drawn off into vats, which, on account of the appear- ance of the oil on cooling, are called graining or seeding vats, where it is allowed to stand for twenty-four hours or more at a temperature of about 85° F. From these vats the semi-solid emulsion of oil and stearin is dipped into cloths, which are folded and placed in a press between sheets of metal and subjected to powerful pressure. By this means the oil is separated from the stearin, and is drawn into casks for export or for manufacture into oleomargarine. Large quantities are annually exported to Holland, where oleomargarine is manufactured, and either sold for consumption in that country, or re-exported to other countries in Europe. The oleo oil thus expressed is a mixture of olein and palmitin. When' first prepared, it is a clear amber-colored fluid, free from odor or fatty taste. It is packed in tierces, and, when opened at ordinary temperature, is a light-yellow solid. The further process of manufacture of oleomargarine consists in * Report on Oleomargarine, Its Manufacture and Sale, 19th An. Report, Mass. St. Bd. of Health, 1887. 542 FOOD INSPECTION AND ANALYSIS. the main of mixing the oleo oil as above obtained with varying propor- tions of neutral lard, milk, and genuine butter, with or without added coloring matter, and churning the mixture at a temperature above the melting-point of the fats, the neutral lard having previously been cured for at least forty-eight hours in salt brine. Occasionally small quantities of other vegetable oils, as cottonseed, peanut, or sesame, are included in the above mixture. After the churning, the whole mass is cooled by contact with ice water. The chilled mass is drained, and afterwards salted, worked, and given much the same treatment as butter. The composition of commercial oleomargarine varies between the following limits: Oleo oil 20 to 25% Neutral lard 40 " 45% Butter ID " 25% Milk, cream, salt, etc. 5 " 30% Coloring of Oleomargarine. — The artificial coloring matters employed are the same as in the case of butter, and are similarly tested for. In many states oleomargarine cannot be legally sold when colored to resemble butter. Under other state laws coloring matter is allowable. The federal law and most state laws prescribe the most rigid rules for marking packages containing oleomargarine, with a view to affording the utmost protection to the producer of butter against the fraudulent substitution therefor. Crampton and Simon's Tests for Palm Oil.* — So called " butter oils," consisting of cottonseed oil to which has been added 2 to 5 per cent of palm oil are used to color oleomargarine. The following tests serve for the detection of palm oil. Preparation of Sample. — The sample should be kept in a cool, dark place until tested, as exposure to air and light, or the presence of water, alcohol, ether or similar reagents interfere with the tests. Immediately before testing, the sample is filtered as quickly as possible at a temperature not exceeding 70° C. First Method. — Dissolve 100 cc. of the fat in 300 cc. of petroleum ether, and shake out with 50 cc. of 0.5% potassium hydroxide. Draw off the watery layer, make distinctly acid with hydrochloric acid, and shake out * Jour. Am. Chem. Soc, 27, 1905, p. 270. EDIBLE OILS AND FATS. 543 with 10 cc. of colorless C. P. carbon tetrachloride. Separate the carbon tetrachloride solution, transfer a portion to a porcelain crucible, add 2 cc. of a mixture of one part of colorless, crystallized C. P. phenol and 2 parts 01 carbon tetrachloride, then 5 drops of hydrobromic acid (sp. gr. 1,19), and mix by gentle agitation.* The almost immediate development of a bluish-green color is indicative of palm oil. Second Method. — Shake 10 cc. of the melted and filtered fat with an equal volume of colorless C. P. acetic anhydride, add one drop of sulphuric acid (sp. gr. 1.53), and shake a few seconds longer.f If palm oil be present, the lower layers on settling out will be found to be colored blue with a tint of green. The color in this as in the preceed- ing test is transient. Of the edible oils only sesame and mustard oils give a similar color reaction. Sesame oil, after repeated extractions with alcohol, will not give the blue color, but cottonseed oil containing as little as 1% of palm oil still responds to the test. Adulterants of Oleomargarine. — This product is liable to adultera- tion not only by the use of inferior and unwholesome fat, but by the admix- ture in some cases of parafhn.l This sophistication is m^ade manifest, if an appreciable amount of the adulterant has been used, by the high melting-point and the low saponification number, as well as by the low specific gravity. If a clear saponification is impossible under ordinary conditions, paraffin is to be suspected. It may be separated and quanti- tatively determined as described on p. 510. Healthfulness of Oleomargarine. — Under the directions of the Mas- sachusetts Board of Health, § a large number of artificial digestion experi- ments were made to show the relative nutritive value of butter and oleo- margarine, and at the same time the wholesomeness of oleomargarine as a food was carefully investigated. The general conclusions reached were that, when comparing the best grades of both products, there is little if any difference between butter and oleomargarine on grounds of digestibility, while a good oleomargarine is much to be preferred to a * Halphen uses a similar reagent to detect rosin oil in mineral oil. Jour. Soc. Chem. Ind., 21, 1902, p. 1474. t The reagents are the same as used in the Liebermann-Storch test for rosin oil. X Geissier, Jour. Am. Chem. Soc, 21, 1899, p. 605. § 19th An. Report, Mass. State Board of Health, 1887, p. 248. 544 FOOD INSPECTION AND /IN A LYSIS. poor butter from a nutritive standpoint. As to its wholesomeness, a large number of experts consulted were unanimous in expressing their favorable opinions of oleomargarine as a healthful article of food. When sold on its own basis in accordance with the law, it forms an excellent cheap substitute for butter. It is only when fraudulently sold as butter or in violation of the various state and federal laws, that it comes within the province of the health authorities to condemn it, and, unfortunately, by reason of its close resemblance to the dairy product ihe temptation to sell it for what it is not is always great. Distinguishing Oleomargarine from Butter. — The two products, made up as they are of mixtures of the same fats, and differing for the most part only in the percentage composition of these fats, show many properties in common. For instance, the melting-point is so nearly the game for both products as to be of no use as a distinguishing indication. Other physical characteristics, as of taste and smell, are very similar in both products, except in the hands of the expert. The microscope is of limited value, except in so far as it indicates that the fat has first been melted and afterwards solidified. From the fact that oleo oil and neutral lard form by far the larger portion of the mixture known as oleomargarine, the glycerides that make up the fat of the latter are chiefly those of the insoluble fatty acids, stearic, oleic, and palmitic. The percentage of volatile fatty acids present in oleomargarine is very small, and the presence of these volatile acids is due entirely to the admixture of butter which it contains. This furnishes the most ready means of distinguishing chemically between the two products, and, as indicated by the Reichert number, is the chief reliance of the analyst for court evidence. Incidentally, as will be seen by the accompanying table, the refrac- CONSTANTS OF BUTTER FAT AND OLEOMARGARINE. > • 2 o •d ■S * o° 0) 3 g 3 "H J) C" •Si 22^ ft g 0,^ ^ a< < 3 w« &^ ^^« ^ Butter fat: Maximum o.870§ 31-551: 89.6ot 5-041: S-62t -8751: 3-iot 233§ i5-8t '^'^■ll 35' Minimum .867§ 4 -441 85.63t 3.oot o.ooj -i-5t 0-49I: 222§ I2.4t 44 -8t 35' Oleomargarine . Maximum .862S§ II .69! 9S-4St i.i6t 3-64t -3Sot 0-741 203 § s-st 54 -St 35° Minimum .858s§ 9-341: Q2.46t 0. 121 2-39t -30631 o-63t I92§ o-St 53 ot 35' * Number of cubic centimeters N/io alkali neutralizing volatile acids in 2.5 grams fat, t From analyses made in Mass. State Board of Health laboratory. t From analyses made in laboratory of U- S. Dept. of Agric, Bur. of Chem. § From analyses by A. H. Allen. EDIBLE OILS AND FATS. 545 tometer reading, the iodine number, the saponification equivalent, and the specific gravity are all useful constants in indicating points of differ- ence between the two fats, it being understood that in oleomargarine, as in butter, the fat for examination is melted and separated by filtra- tion or otherwise from the curd, salt, and other constituents. The constants for varying mixtures of butter with foreign fat as found by Villiers and Collin * are tabulated below. Odor and Taste. — It is easy with a little practice to become so accustomed to the odor and taste of oleomargarine, as to be able to pass judgment with considerable confidence by these senses alone, whether a sample in question is oleomargarine or butter. The distinction is rendered more apparent by melting a portion of the sample on the water- bath. If the product is butter, either fresh or renovated, the butyric odor of the melted fat is very characteristic, while the melted oleomargarine not only is lacking in the butyric odor (a negative property), but possesses a distinctive "meaty" smell peculiar to itself, which, while not unpleasant, is unmistakable. The flavor of oleomargarine to one experienced in dis- tinguishing between the two products is very apparent. This flavor, slight though it is, might be compared to that of cooked meat. Hehner's Soluble Koettstorfer's Volatile Number. Acids. Equivalent. Acids. Pure butter 88 5 224 26 Butter, 95%; foreign fat 5%---- 88-35 4.8 222.6 24-7 ' 90% << << 10%.... 88 70 4-5 221.2 23-4- ' 85% " " 15%-- ■■ 89 05 4-3 219.8 22.2 ' 80% << <( 20%.... 89 40 4-1 218.4 20. 9' ' 75% (S << 25%---- 89 75 3-9 217 19.6 ' 70% << 11 30%---- 90 10 3-6 215.6 18.3: ' 65% <( <( 35%---- 90 45 3-4 214.8 17.1 ' 60% " " 40%---- 90 80 3-2 212.8 15.8 ' 55% " " 45%---- 91 15 3 211. 4 14-5 ' 50% (< << 50%---. 91 50 2-7 210 13.2 ' • 45% (( '( 55%---- 91 85 2-5 208.6 12 ' 40% <( (< 60%.... 92 20 2-3 207.2 10.7 * 35% " " 65%-.-- 92 55 2.1 205.8 9-4 ' 30% << (( 70%...- 92 90 1.8 204.4 8.1 ' 25% (< (( 75%---- 93 25 1.6 203 6.9 ' 20% <( <( 80%.... 93 60 1-4 201.6 5-6 ' 15% " " 85%--.- 93 95 1.2 200.2 4-5 ' 10% <( <( 90%-.-- 94 30 0.9 198.8 3 " 5% << <( 95%---- 94 65 0.7 197.4 1.8 Fo] "eign fat. . 95 0-5 196 0-5 yj * Les Substances Alimentaires, p. 731, 546 FOOD INSPECTION AND ANALYSIS. DISTINGUISHING BETWEEN BUTTER, PROCESS BUTTER, AND OLEOMARGARINE. With the increased occurrence in the market of the commercial product known as " process " butter, especially in localities where its sale is restricted or regulated by law, it becomes incumbent on the analyst to distinguish it from the other products which it resembles. As a rule, the tests, chiefly physical, that are applied on the edible prod- uct as a whole (i.e., without separation of the curd, salt, etc.), such as the foam test, the milk test, the microscopical examination, and the appear- ance of the melted sample, distinguish broadly between pure fresh butter on the one hand, and oleomargarine on the other. In other words, al- though there are those skilled in making the above tests who claim to be and doubtless are able to note distinguishing features between oleo- margarine and process butter, yet these two products respond alike, though perhaps in varying degrees, to these tests, and are classed together as distinguished from pure butter. On the other hand, such tests as depend upon the refractometer, the Reichert number, and, indeed, all the so-called chemical constants, which are applied to the separated fat, freed from other substances, will serve to distinguish between oleomargarine and butter, whether "pro- cess" butter or otherwise, since the *' processing " or "renovating" of butter does not change the character of its fat sufficiently to materially alter these constants. It is best, therefore, for purposes of routine preliminary separation to submit all samples to the "foam" test and to examine them by the butyro-refractometer.* These tests alone, which are very quickly and readily applied, will rarely fail to separate into the three classes, butter, pro- cess butter, and oleomargarine, the products under examination, after which such confirmatory tests as are desired are made on adulterated samples. The Butyro-refractometer. — This instrument, as its name implies was primarily intended by Zeiss for the examination of butter, and, while its use has been extended for work with other fats and oils, its construc- tion is such as to show particularly a distinction between butter and oleomargarine by the appearance of the critical line of the fat. This mode of differentiation is due to the peculiar construction of the double * Out of the large number of samples of butter and oleomargarine examined on the butyro-refractometer in the author's laboratory during eight years, he has never found a single instance where the instrument failed to show the dilTercnce between the two products EDIBLE OILS AND FATS. 547 prism, which shows differences of dispersive power by different appear- ances of the critical Hne. The prisms are so constructed that the critical line of pure butter is colorless, while margarine and artificial butter, which have greater dispersive powers than natural butter, show a blue-colored critical line. But anomalies in the color, both with pure butter and mixtures, are more or less observable, which render it im- possible to draw a sharp line between adulterated and genuine butter. The appearance of a blue fringe may, however, be a useful factor in cases of suspected adulteration. The following particulars respecting the application of the refractom- eter for analysis of butter are contained in a paper of Dr. R. Wollny of Kiel,* who assisted in the construction of the instrument. The readings of the refractive indices of a large number of butter samples taken at 25° C. by Dr. Wollny have been directly reduced to scale divisions and yield the following equivalents : Natural butter. . . (i .4590 — i .4620) : 49 . 5 — 54 .0 scale divisions Oleomargarine. . .(1.4650 — 1. 4700): 58. 6 — 66.4 |' " Mixtures (artificial butter) (1.4620 — 1. 4690): 54. 0—64. 8 " " Limit of Scale Reading for Pure Butter. — ^Whenever in the refracto- metric examination of butter at a temperature of 25° C. higher values than 54.0 are found for the critical line, these samples will, according to, Wollny, by chemical analysis always be found to be adulterated ; but with all samples in which the value for the position of the critical line does not reach 54.0 chemical analysis may be dispensed with, and the samples may be pronounced to be pure butter. Wollny suggests, as a means of removing all chances of adulterated butter escaping detection, that the above limit be placed still lower, and that all samples exhibiting values exceeding 52.5 (at a temperature of 25° C.) be set aside for chemi- cal analysis. In calculating the position of the critical line for other temperatures than 25° C. allow per 1° C. variation of temperature a mean value of * Dr. R. Wollny, Schlussbericht liber die Butteruntersuchungsfrage, Milchwirthschaft- licher Verein, Korrespondenzblatt, No. 39, 1891, p. 15. Older papers on butter tests by refraction of light will be found in: Mueller, Rep. ,d. anal. Chemie, 1886, pp. 346, 366. Skalweit, Milchzeitung, 1886, 15, p. 462. Wollny, Ueber die Kunstbutterfrage, Leipzig, 1887, p. 50. 548 FOOD INSPECTION AND ANALYSIS. 0.5 c; scale division.* The following table, which has been compiled in this manner, shows the values corresponding to various temperatures, each value being the upper limit of scale divisions admissible in pure butter : Temper- Scale Temper- Scale Temper- Scale Temper- Scale ature. Division. ature. Division. ature. ■ Division. ature. Division. 45^= 41-5 40= 44-2 35° 47-0 30° 49-8 44° 42.0 39° 44-8 34° 47-5 29° 50.3 43° 42 .6 38° 45-3 33° 48.1 28° 50.8 42° 43-1 37° 45-9 32° 48.6 27° 51-4 41° 43-7 36° 46.4 31° 49-2 26° 51-9 40° 44-2 35° 47.0 30° 49-8 25° 52.5 If, therefore, at any temperature between 45° and 25° values be found for the critical line which are less than the values corresponding to the same temperature according to the table, the sample of butter may safely be pronounced to be natural, i.e., unadulterated butter. If the reading shows higher numbers for the critical line, the sample should be reserved for chemical analysis. Note. — Dr. Eichel of Metz has suggested that instead of comparing the scale divisions at the same temperature, the position of the critical line may be determined at the moment when the butter begins to set. In this case he gives fifty-four as the highest admissible number for the critical line of pure butter. No sharp distinction is apparent between pure and renovated butter on the refractometer. Special Thermometer for the Butyro-refractometer. — Instead of em- ploying the ordinary thermometer, as shown in Fig. 36, a special ther- mometer (Fig. Id) has been devised for work both with butter and with lard. This instrument has two scales, arranged side by side, one for butter and one for lard, each of which indicates at once the highest allowable reading for the pure fat, corresponding to the temperature at which the observation is made, which, however, need not be noted. If the scale reading of the instrument, as observed through the tele- scope, differs materially from the reading of the special thermometer, the fat under examination is undoubtedly adulterated, or, in the case of butter, a higher reading indicates oleomargarine. The special ther- mometer thus indicates the highest permissible number for pure butter. * With natural butter this number is, as a rule, somewhat less (0.53), with oleomargarine a little greater (0.56). EDIBLE OILS AND FATS. 549 The Reichert or Reichert-Meissl Number * is by far the most impor- tant single determination in establishing proof of the character of the sample, whether butter or oleomargarine, for evidence in Q court, and in such cases this determination is indispensable. The result is conclusive, excepting in those rare instances where the admixture of foreign fat is so small as to cause the Reichert number to approximate that of pure butter. In common instances of creamery butter and commercial oleomargarine the Reichert number shows a very marked distinction (see table, p. 544). It is difficult to iix a minimum figure below which, in doubtful cases, a sample may be pronounced impure by reason of admixture with foreign fat. In general, how- ever, a Reichert number under 10 would be almost sure to show adulteration, though instances are on record where butter of known purity has shown a Reichert number even lower than this. It is in fact rare that pure butter has a Reichert number under 12. Stebbins f gives the maximum, minimum, and average of the Reichert number obtained by him on 317 samples of unadulterated butter, some of which were of low grade ' Fig. 10 1.— Special as follows: Maximum, 18.2; Minimum, 11. 2; Average, 14.7. Butyro-refrac- As a rule little difference is apparent between pure tometer Ther- and "renovated" samples as regards their Reichert Butter and number. Lard. Vieth has shown that the Reichert number of butter is generally a trifle lower after it becomes rancid. Specific Gravity. — -Skalweit has shown that the specific gravity of butter and oleomargarine relati\-e to each other varies with the temper- ature at which it is taken, the difference between the two growing less and less as the temperature increases above 35°. The greatest variation being at 35°, he recommends this temperature as the best at which to make the determination. The Foam Test, also known as the " boiling " or " spoon " test.J This, though originally intended as a household test, is in reality one of * The writer prefers to carry out this process on 2.5 grams of the butter fat, expressing thus the Reichert number, this being practically the half Reichert-Meissl number, which is based on the use of 5 grams. t Jour. Am. Chem. Soc, 21, 1899, p. 939. {Farmer's Bulletin, No. 131. 553 FOOD INSPECTION AND AN < LYSIS. the very best laboratory methods of separating pure butter samples from renovated butter and oleomargarine. A small lump of the sample (from 3 to 5 grams) is heated in a large spoon over a Bunsen flame, turned very low, stirring constantly during the heating. Genuine butter, under these conditions, will boil quietly, but with the production of consider- able froth or foam, which will often swell up over the sides of the spoon, when, just after boiling, the latter is raised from the flame. Renovated butter or oleomargarine, under this treatment, will bump and sputter noisily like hot grease containing water, but will not foam.* Another point of difference is that on removing the spoon from the flame and observing the character of the curdy particles, in the case of genuine butter these particles of curd will be very small and finely divided in the melted fat, being indeed hardly perceptible, while with oleomargarine and renovated butter, the curd will gather in somewhat large masses or lumps. The test may be carried out in a test-tube if desired. The Waterhouse or Milk Test.f — This test is based on the assump- tion that butter fat, which is in itself exclusively the product of milk, will mingle intimately with the milk when added thereto in a melted condition and cooled therein, whereas oleomargarine, being foreign to milk fat, will, under like conditions, refuse to dift'use itself naturally in milk as a medium. About 50 cc. of well- mixed sweet milk are heated nearly to boiling in a beaker, and from 5 to 10 grams of the fat sample are added. The mixture is then stirred, preferably with a small wooden stick, until the fat is melted. The beaker is then placed in a dish of ice cold water, and the stirring continued till the fat reaches the solidifying-point, at which period, if the sample is oleomargarine, the fat can readily be collected by the stirrer into one lump or clot, but, if butter, it cannot be so collected, but remains in a granulated condition, distributed through the milk in small particles. It is not necessary to keep up the stirring through the entire term of cooling, but to begin stirring before the fat starts to solidify, which should require from ten to fifteen minutes after the mixture is placed in cold water. This test, if carefully carried out, shows a marked distinction between butter, whether pure or renovated, and oleomargarine. Under certain conditions, as when the cooling is too rapid, samples of renovated butter, * A very slight foam is sometimes observable with occasional renovated samples, but nothing like the abundant amount produced by the genuine product. i t Parsons, Jour. Am. Chem. Soc, 23, 1901, p. 200. EDIBLE OILS AND FATS. 55 1 fat will sometimes show a slight tendency to clot together as in the case of oleomargarine, but to no such extent as the latter. The author's experience with this test has shown it to be very reliable not only in identifying oleomargarine from butter, but in nearly every case renovated butter can be distinguished from genuine. As a rule, genuine butter fat, even after cooling to the solidifying-point, shows the greatest tendency to emulsionize with the milk when stirred, without adhering to the wooden rod, and is slow to come to the surface when the stirring is stopped. Renovated butter fat, when stirred in the cold milk, almost instantly gathers in a film on the surface of the milk when the stirring is stopped, without emulsionizing. It does not clot together like oleomargarine, but it tends to adhere to the wooden rod. Patrick* recommends the use of skimmed or partially skimmed milk, and. heats to the boiling-point after the fat has been introduced into the hot milk. Examination of the Curd. — The curd of genuine butter is made up largely of such of the milk proteins as are insoluble in water and hence pass into the cream when separated. . These proteins form a gelatinous mass in the butter, readily clotting together when the fat is meUed. On the other hand, the curd of process butter, which is, as it were, artificially derived from the entire or skim milk used in its manufacture (in order to replace the natural curd which has been removed in the "purifying" process), differs from the proteins of cream in that it is granular and flaky, consisting chiefly of coagulated casein. Hence the distinction noted as to the appearance of the curd in the foam test. For the same reason, if beakers containing pure and renovated butter are melted on the water-bath, the curd of the pure sample will settle at once, or in a very few minutes, to the bottom after melting, leaving a comparatively clear supernatant fat. The renovated sample will nearly always fail to settle out clear, even after standing on the water-bath for half an hour or more, but will still be cloudy throughout the mass, due to particles of non-cohesive, floating curd. In the case of oleomargarine, the curd of which is composed partly of pure butter curd (from cream proteins) and partly of the proteins of the milk with which it is churned, the cloudiness of the fat on melting depends on the relative proportion of milk proteins, and in general is not especially characteristic. ^ ^^^________^_____ ' * Farmer's Bulletin, No. i^i. 552 FOOD INSPECTION AND ANALYSIS. Identification of the Source of the Curd * Half fill a small beaker with the sample and melt on the water-bath. Decant as much as possible of the fat and pour the rest, consisting largely of the water, salt, and curd, upon a wet filter. Acidify the filtrate, which contains the salt and soluble proteins, with acetic acid and boil. If the sample is pure butter, only a slight milkiness is found, indicating absence of albumins, whereas, in the case of process butter, a white, flocculent albuminous precipitate is produced. Apply to the filtrate also Liebermann's test for albumin; i.e., add strong hydrochloric acid. If a ^dolet coloration is produced, the sample is presumably " process " butter. Microscopical Examination of Butter. Considerable information may in general be gained by an examination of the sample under ordinary light and with a rather low power, say from 120 to 150 diameters. For examination in this way a bit of the sample on the edge of a knife blade is placed on the glass slide, and simply pressed lightly into a thin film by the cover-glass. A very characteristic difference between genuine and renovated butter is at once seen in the relative opacity of the fields. The fat film, in the case of the fresh, pure butter, is much more transparent than that of the renovated. . Again, the curd is so finely divided through- out the mass of genuine butter fat that the field- is much more even than that of the renovated, wherein often large and opaque patches of curd are frequently distributed throughout the field. When a renovated butter sample, mounted as above, is viewed hy reflected light, for which purpose the microscope mirror is turned so as not to transmit light through the instrument, one sees a very dark and scarcely perceptible field; but the opaque patches of curd above referred to are strikingly apparent as white masses against a dark background. With Polarized Light. — It has already been stated that the micro- scope is useful in showing whether or not a fat has been melted, the crystalline structure of the fat once melted and afterward cooled being rendered apparent, especially when viewed by polarized light. This fact has long been known and put to practical use in the identification microscopically of butter and oleomargarine, f When viewed by polarized light between crossed Nicols under a low magnification, pure butter not previously melted should show no * Hess and Doolittle, Jour. Am. Chem. Soc, 22, 1900, p. 151. t Hummel, ibid., 22, p. 327; Crampton, loc. cit., supra, p. 703. EDIBLE OILS AND FATS. 553 crystalline structure, being uniformly bright throughout, and, if the selenite plate be used, should present an even colored field, entirely devoid of fat crystals. On the other hand, with process butter or oleo- margarine, both of which have been melted and subsequently cooled ^ the crystalline structure should be marked, showing with polarized light a more or less mottled appearance, and a play of colors with the selenite. Various conditions enter in to affect the reliability of the polarized light test. It is nearly always possible in cold weather to observe these dis- tinctions in practice, as above described, in a sharp and striking manner. Figs. 269, 270, and 271, PI. XXXVIII, show typical fields of the three products with crossed Nicols and selenite plate. The appearance of pure butter is perfectly blank, while oleomargarine presents a much more mottled appearance than renovated butter. Such well-defined points of variation as are shown in Plate XXXVIII are not always to be seen in practice, even in the hands of an expert. Pure butter sometimes exhibits a somewhat mottled field, due to a slight crystallization at some period of its history. In the summer-time, for instance, when butter melts so easily at ordinary temperature, these distinctions between pure and adulterated samples as shown by polarized light are by no means as satisfactory as in the winter. Great care should be taken on this account, on the part of the col- lector of samples as well as the analyst, to keep the sample from melting under ordinary conditions before it is examined. Hess and Doolittle's Method of Examining the Curd.* — A convenient portion of the sample of suspected butter is melted in a beaker, as much of the fat as possible is decanted off, and the remaining curd, washed free from fat with ether, is poured out on a glass plate and dried. A sample of pure butter is treated in like manner by way of comparison. When examined under a very low magnification of from 3 to 6 diameters, the curd from the pure sample will be seen to be non-granular and amorphous in appearance, while, in the case of renovated butter, the curd will appear very coarse grained and mottled. Zega's Test for Oleomargarine.t — A portion of the filtered fat is poured into a test-tube and kept for two minutes in a boiling water-bath. I cc. of this fat is then measured with a hot pipette into a 50-cc. tube con- taining 20 cc. of a mixture of 6 parts ether, 4 parts alcohol, and i part glacial acetic acid. The tube is stoppered, shaken well, and cooled in ■* Jouii Am. Chem. Soc, 22, igco, p. 151. I Chem. Zeit., 1899, 23, 312; Abs. Analyst, 24, p. 206. 551 FOOD INSPECTION AND ANALYSIS. water at 15° to 18° C. In the case of pure butter fat, the solution remains clear for some time, a slight deposit being apparent only after standing an hour or more. With oleomargarine, a deposit is evident in a very short time, and in ten minutes a heavy precipitate comes down. With 10% of oleomargarine in butter, a separation occurs in about fifteen minutes. When a few solid particles have separated out, they are with- drawn and examined under the microscope. With genuine butter, long narrow rods appear, sometimes pointed at the ends, often bent, and grouped as a rule centrally in star-shaped bundles. Oleomargarine presents an appearance of bundles of fine needles, closely packed to form masses frequently resembling sheaves and dumb bells in shape. Identification of Various Oils and Fats. — Cottonseed oil may be recognized, if present in butter or its substitutes, by the Halphen test, and sesame oil by the Baudouin test. Peanut oil is tested for by the Bellier or Renard test. Cocoanut oil is sometimes said to be present in butter substitutes. It has a higher Reichert number than most adulterants, and hence a larger admixture of this than of other foreign fats could be used, without lowering the Reichert number of the whole below the allowable limits of pure butter. Its presence would, however, be rendered apparent by the low iodine and refractometer numbers and the high Polenske number. LARD. Nature and Composition. — ^Lard is the fat of hogs, separated by heat from the scraps or containing tissues. The choicest or highest grade of lard is known as leaf lard, and is derived from the fat which surrounds the kidneys. A comparatively small part of the lard of commerce is, however, strictly speaking, pure leaf lard. Most of it is derived from the whole fat of the animal by rendering, by the aid of steam under pressure, either in open kettle or in closed tanks, the former being used more often for rendering lard on a small scale, and the latter being the most common commercial method. Next to the leaf, the fat from the hog's back is considered the best in quality, after which is graded, in the order named, the fat from the head, the region of the heart, and the small intestines, the last two grades constituting what is commonly known as "trimmings." Good lard is white and granular, having the consistency of salve. It has an agreeable, characteristic odor and taste. The leaf or kidney fat furnishes also the source of the so-called neutral lard, already mentioned as an ingredient of oleomargarine. The leaf, EDIBLE OILS .4ND FATS. 555 being first chilled and finely ground, is placed in the kettle and ren- dered at a temperature of from 40° to 50° C, at which heat only a portion of the lard separates. This portion is, while melted, washed with water containing salt or dilute acid, and forms the neutral lard, a -product almost entirely free from odor. The remainder of the leaf is then trans- ferred to the closed tank and subjected for some hours to steam under pressure at a temperature of 230° to 290° F., the resulting lard being graded as pure leaf lard. The composition of the mixed fatty acids of lard is thus calculated by Twitchell: Linoleic acid 10.06% Oleic acid 49 . 39% Solid acids (by difference), stearic and palmitic .. 48.55% Lewkowitsch * gives the following constants for American lards made from fat from different parts of the animal: Specific Gravity at 100° C. (Water at i5°C. = i.) Iodine Value. Maumene Number at 40° C. Melting-point, Bense- mann'st Method. Refractive Index. Fat from Temp.C. of Incipient Fusion. Melted to a Clear Drop. Butyro- refractom- eter at 40° c. Head 0.8637 0.8629 0.8631 O.8611 0.8621 0.8616 0.8637 0.8615 0.8700 0.8589 0.8641 0.8615 0.8628 66.2 66.6 65.0 61.5 65.0 65.1 62.2 59-0 63.0 68.8 68.4 66.6 68.3 2>i 32 34 37 35 38 30 38 24 24 24 28.5 28.5 31-5 26 29 28.5 24 26 26 26 44-8 44.8 45-0 48.5 48.5 46 45 44 44-5 40 45 44 44.5 52.6 52.5 52.0 52-4 51.8 51-9 51-4 50.2 52.0 44-8 Back Leaf Foot Ham 51-9 51-9 53-0 Ham (German) . 0-8597 55-0 30 32 46 49-2 Lard Oil. — This oil is obtained by subjecting lard contained in woolen bags to hydraulic pressure in the cold. The lard o'A (chiefly olein) thus expressed constitutes nearly 60% of the whole, and the residue is known as lard stearin. Lard oil is a thin fluid, pale yellow in color, and with var}^ing specific * Oils, Fats, and Waxes, 1904, p. 781. t Bensemann distinguishes between the temperature at which the fat begins to liquefy and that at which it becomes completely transparent. 556 POOD INSPECTION /IND /IN A LYSIS. gravity, due to varying conditions of pressure and temperature. It has a pleasant, though somewhat bland taste, and is used to some extent as an edible oil. It is used in France as an adulterant of olive oil, and with the Maumene, elaidin, and nitric acid tests, it behaves much like olive oil. According to the U. S. Pharmacopoeia, the specific gravity of lard oil should be from 0.910 to 0.920 at 15° C. At a temperature a little below 10° C. it should form a semi-solid white mass. When it is brought in contact with concentrated sulphuric acid, a dark reddish-brown color should instantly be produced. Lard oil should not respond to the Bechi test for cottonseed oil. If 5 cc. of the oil, contained in a small flask, be mixed with a solution of 2 grams of potassium hydroxide in 2 cc. of water, then 5 cc. of alcohol added, and the mixture heated for about five minutes on a water-bath with occasional agitation, a perfectly clear and complete solution should be formed, which, on dilution with water to the volume of 50 cc, should form a transparent, light-yellow liquid, without the separation of an oily layer (absence of appreciable quantities of paralSn oils). Adulterants of lard oil are cottonseed and corn oils. Compound Lard. — The article so extensively made and sold under this name is a mixture consisting usually of lard stearin, beef stearin, and cottonseed oil. Sometimes no lard whatever is present, but only a mixture of beef and cottonseed stearins. Lard stearin is the residue left in the cloths after the lard oil has been removed by pressure (p. 555). Beef stearin is, similarly, the residue from which oleo oil has been expressed (p. 541). The cottonseed oil used is highly refined, and finally decolorized by mixing with fullers' earth and filtering. U. S. Standards. — Standard Lard and Standard Leaf Lard are lard and leaf lard respectively, free from rancidity, containing not more than 1% of substances other than fatty acids, not fat, necessarily incorporated therewith in the process of rendering, and standard leaf lard has an iodine number not greater than 60. Adulteration of Lard. — The mixture known as "compound lard" is quite commonly fraudulently sold for pure lard. Indeed, the adul- terants of lard usually met with are cottonseed oil or stearin and beef stearin. Other oils said to have been used as adulterants are peanut, sesame, corn, and cocoanut. Formerly water was incorporated into EDIBLE OILS AND FATS. 557 the fat to such an extent as to materially cheapen it, but this sophistica- tion is now rare. Aloisture is determined as in the case of butter. The Butyro-refractometer Reading. — The refracting degree of cotton- seed oil on the butyro-refractometer is about 8.9 in excess of the standard refraction of lard, while that of beef tallow is about 3.8 less than the standard. If, therefore, the refractometer reading is unusually low, the presence of beef stearin is to be suspected; if unusually high, cottonseed oil should be looked for. A mixture of the two adulterants with pure lard such as is found in "compound lard," may sometimes, though not often, be found to give refractometric readings within the limits of pure lard. Detection of Foreign Oils. — Cottonseed oil is best detected by the Halphen test. A very slight color reaction should not be taken as proof positive of. the admixture of cottonseed oil, since it has been found that the fat of hogs fed on cottonseed meal gives a slight reaction with both the Bechi and the Halphen tests. Sesame and peanut oils are detected by their special tests. Corn oil is indicated by the abnormally high refractometric reading and iodine number, cocoanut oil by the high Reichert number, the high saponification equivalent, and especially the high Polenske number. Beef stearin is difficult to identify chemically, but is usually distin- guished by a microscopical examination of the fat after crystallization as follows : The Microscopical Examination of Lard. — From 2 to 5 grams of the fat are dissolved in 10 to 20 cc. of ether* in a test-tube, and the solu- tion allowed to stand 12 hours or over night at about 20° C, the test- tube being loosely stoppered with cotton. The crystals obtained vary considerably with the condition of heat, amount of solvent, rate of crys- tallization, etc., so that the operator had best vary these conditions till he is satisfied that the best possible results have been obtained. It is often advantageous to separate the crystals first obtained by filtration from the mother liquor, and to redissolve in ether and recrystallize in a second test-tube. The crystals formed at the bottom of the test-tube are, for the purpose of thus purifying, separated from the mother liquor by filtration through a small filter, and the precipitate washed several times with ether. The washing with ether should not be continued so long that the crj^stals are perfectly freed from mother liquor and olein, for in this case they are so dry and pulverulent as to require a mountant when on the slide for microscopical examination. The writer prefers * Some analysts get better results with a mixture of ether and alcohol. 558 POOD INSPECTION yIND ANALYSIS. to have them sHghtly oleaginous, so that when applied to the slide no mountant need be used. In this case the crystals seem to stand out in wider contrast to the background than when cottonseed oil, the usual medium, is used. If the crystals are, however, in a pulverulent condition, a drop of alcohol can be used as a mountant, or oil, as preferred. Mounted under a cover-glass they are examined under various powers of the microscope. Figs. 272 and 273, PI. XXXIX, show the typical appearance of pure lard stearin from a leaf lard of known purity, and Figs. 276, 277^ and 278 illustrate beef stearin. These figures show distinctive crystal- lization of each form under the best conditions. The lard stearin crystals when thus obtained are fiat rhomboidal plates cut off obliquely at one end, and are grouped irregularly, as if thrown carelessly together. The beef stearin crystals, on the other hand, are cylindrical rods or needles, often curved, with sharp ends, and are arranged as shown in fan- shaped clusters. Conditions of crystallization are frequently such as not to show the sharp distinctions noted above. Both forms of crystals are at times apt to gather in clusters that at first sight appear somewhat similar, and are often misleading as to their true character. It is found almost invariably that the beef stearin crystals gather in clusters, radiat- ing from a common center or point, often with a peculiar twisted appear- ance, breaking up into little fans. Lard crystals, it is true, do not always lie flat in irregular groups as shown in Fig. 272, but, as in Fig. 274, form clusters that, unless studied carefully, might at first sight be considered as identical with the fan shapes of the beef stearin already described. It will be seen, however, that if the best possible conditions are attained, the crystals of lard, instead of radiating from a point, are arranged more like feathers or alternate leaves on a branch, each crystal being given forth from another close at hand. Moreover, the lard crystals are themselves straight and not curved, the apparent curve in the appearance of the clusters being, on careful examination, especially under high power, seen to be chiefly due to several of these straight crystals arranged at angles to each other. Even when the highest powers of the microscope are applied to the beef stearin crystals, they will always appear as cylindrical, sharp- pointed rods, some straight, others curved; while with the lard crystals they should be capable of showing the thin, flat, oblique-ended structure when examined with higher powers, even when they are arranged in the feathery clusters, the apparently pointed ends of some of the crystals EDIBLE OILS AND FATS. 559 being due to the fact that the plates are viewed edgewise. This is apparent in Fig. 275, in which the crystals are magnified to 480 diameters. According to Belfield, who was one of the earliest to employ the micro- scope for identification of foreign fat in lard, it is possible to detect well- defined crystals of both lard and beef stearin in mixtures crystallized out in the above manner from ether. Later investigators, however, find difficulty in getting both kinds of crystals in the final deposit, it being the more common experience that the character of the final crystals from a mixture of the two fats more often tends to one or the other forms of crystallization. Repeated crystallizations may change the character of the crystals and a number of such crytallizations should therefore be made before final judgment is passed. The Iodine Number (p. 487). — This test is generally prefigured by the refractometer. Cottonseed oil will absorb about 108% of its weight of iodine, while beef fat will absorb about 37%. ANALYSES OF SAMPLES ILLUSTRATING TYPES OF LARD, LARD SUBSTI- TUTES, AND MIXTURES. Nitric Acid Test. Crystallization. Bechi Reac- tion. Butyro-refrac- tometer. Oi C 0$, Conclusion. K L M N Slight color. Red Slight color Very slight color Deep-brown red Red Very slight color Deep brown Red Lard stearin None Beef stearin Few small bunches Lard stearin Lard and beef stearin Lard stearin Lard arid beef stearin Deep color <( =2.8835° Ventzke. 1° Ventzke =2.6048° Wild (sugar scale). 1° Wild (sugar scale) =0.3840° Ventzke. 1° " " " =0.1331° angular rotation Z). I ° angular rotation Z> =7.5110° Wild (sugar scale) 1° Laurent (sugar scale) =0.2167° angular rotation D. 1° angular rotation £> =4.6154° Laurent (sugar scale). 1° Soleil-Duboscq = 0.2167° angular rotation D. ^0 < < < < = 0.2450° " ;. jO «< t( = 0.620° Soleil-Ventzke. jO < < < ' = 1.619° Wild. 1° Soleil-Ventzke = 1.608° Soleil-Duboscq (old scale). jO 11 << = 1-593° " " (new scale). 1° Wild = 0.611° " " (Wild normal weight 10). jO ct = 1.223° " ( " " " 20). Normal Weights of Sugar for Different Instruments. — The follow- ing normal weights (number of grams in 100 cc. at 17.5° C.) are those on which the scales of the various instruments are based: Soleil-Ventzke, 26.048; Soleil-Duboscq 16.29 (formerly 16.19); Wild, usually, 10 or 20; Laurent, 16.29. The International Commission for Uniform Methods in Sugar Analysis has decided to use for the Ventzke scale 26 grams and make up at 20° C. to 100 metric cc, which figures are approximately equivalent to 26.048 grams made up to loo Mohr cc. 584 FOOD INSPECTION AND ANALYSIS. Specific Rotary Power. — This is a theoretical term to express a stand- ard by which the various optically active substances may be compared^ and is understood to mean the amount in angular degrees through which the plane of polarization of a ray of light of stated wave length is rotated by I gram of a given substance in aqueous solution of i cc. and forming a column i decimeter in length. The actual rotary power of a solution varies directly with the length of the column traversed by the light, with the concentration of the solution, and with the wave length of light, hence the need of a purely theoretical basis for purposes of comparison. The specific rotary power is usually expressed as [a]/? or [a]y, the letters D or j indicating the character of the light. Thus, D indicates the monochromatic light obtained from the sodium flame, named from the D line of Fraunhofer in the yellow portion of the spectrum, while j (from the French jaune) indicates what is known as the transition tint, the rcse-purple color produced when ordinary white light passes through the polarizer and analyzer, placed with their principal sections parallel to each other and with a plate of quartz 3.75 mm. thick interposed between them.* The specific rotary power is determined as follows; r 1 r 1 ^°°^ \pi\o or W\j=-^, ■■ where a = observed angular rotation, c = grams of the substance in 100 cc. of the solution, and /= length of the observation-tube in decimeters; or, in cases where, instead of the grams per 100 cc, the percentage composition is known (expressed by ^ = grams of the substance in 100 grams of the solvent), and the specific gravity (expressed by d), then [a]^ or [«]/= „ . Birotation. — In polarizing solutions of all the common sugars other than sucrose the phenomenon of birotation should be taken into account, whereby a change in optical activity is shown by standing. Thus, solu- tions of dextrose, levulose, and lactose polarize much higher when freshly prepared than after long standing, requiring in some instances several hours before the lowest or normal figure is reached. Maltose, on the other hand, increases in polarization after standing in solution. By * Some confusion is caused by the adoption of the characters D and j, since both would naturally seem to indicate yellow light. The so-called transition tint above defined is, how- ever, complementary to the mean yellow, or jaune tnoyen, and it is the complementary color and not the yellow itself that is indicated by the character /- 'SUGAR AND SACCHArJNB PRODUCTS. 585 boiling the solution it may be at once brought to its correct reading. The desired result may also be accomplished by adding a few drops of ammo- nia, either treatment being resorted to before the solution is made up to the required volume. ANALYSIS OF CANE SUGAR AND ITS PRODUCTS. Qualitative Tests for Sucrose. — (a) Polariscope Test. — The substance to be tested, if not already in solution, is dissolved in water, and if the solution is not perfectly clear, is clarified by the addition of alumina cream or by subacetate of lead (p. 586) and filtered. An observation tube is filled with the clear solution and the polariscope reading noted. A measured portion of the same solution is then treated with one-tenth its volume of concentrated hydrochloric acid and is subjected to inversion (p. 588), after which the same tube as before is filled with the inverted solution and a second reading obtained, one-tenth of the observed reading being added for the true invert polariscopic reading. If the two readings are virtually the same, sucrose is absent, but, in the presence of sucrose, the second reading will be considerably lower than the first or may even be to the left of the zero. (b) Test with Nitrate 0} Cobalt.* — Prepare a 5% solution of cobaltous nitrate, and a 50% solution of potassium hydroxide. If the sugar solution to be tested contains dextrin or gums, these should first be removed by treatment with alcohol. 15 cc. of the sugar solution to be tested are mixed with 5 cc. of the cobaltous nitrate reagent, and 2 cc. of the potas- sium hydroxide solution are added. Sucrose produces under these con- ditions a permanent amethyst-blue color, while dextrose gives at first a turquoise-blue passing over into light green. In a mixture of the two sugars the color due to sucrose will predominate. According to Wiley, i part of sucrose in 9 parts of dextrose may be detected by this test. Analysis of Cane Sugar. — In the case of commercial granulated or loaf sugar the sucrose determination is usually all that is necessary to determine its purity, and the same is true, as a rule, of the powdered white sugars. A fairly complete analysis of raw or brown sugar con- sists in the determinations of moisture, sucrose, invert sugar, ash, organic non-sugars, and quotient of purity. Care should be taken that the portion subjected to analysis is a fair representation of the whole, and is perfectly homogeneous. * Wiley, Ag. Anal., p. 189. 586 FOOD INSPECTION AND /IN A LYSIS.' Determination of Moisture. — 2 to 5 grams of the sample are dried in a flat, tared metal dish, to constant weight in vacito, or in a McGill oven* in a current of air, at about 7o°C.,at which temperature levulose is not decomposed. For ordinary purposes sufhciently accurate results may be obtained by the A. O. x\. C. method of drying to constant weight at 100° C. in a water oven. Determination of the Ash. — The residue from the moisture deter- mination is burned slowly and cautiously over a low flame until frothing has ceased. Afterwards increase the flame and ignite to a white ash at a low, red heat. In igniting saccharine substances which contain an appreciable amount of cane sugar, the contents of the dish will swell up and froth, unless great care be taken, to such an extent as to flow over the sides of the dish, occasioning loss and inconvenience. Such frothing may be largely held in check by directing the flame at first down from above upon the pasty mass, instead of from under the dish as ordinarily, till all is reduced to a dry char, afterwards continuing the ignition from below in the usual manner. Organic Non-sugars. — These consist mainly of compounds of organic acids, together with gum, coloring matter, albuminous bodies, etc. They are determined by difference between 100% and the sum of the sucrose, invert sugar, moisture, and ash. Quotient of Purity. — By this term is meant the percentage of pure sugar in the dry substance. It is calculated by dividing the per cent of sucrose by the percentage of total soHds and multiplying ttie result by 100. Determination of Sucrose by the Polariscope. — Reagents. — Lead Sub- acetate Solution.-^ — Boil for half an hour 430 grams of normal lead acetate, 130 grams of htharge, and 1000 cc. of water, allow to cool and settle. Dilute the supernatant liquid to 1.25 specific gravity with recently boiled water. * A. McGill, Laboratory of Inland Revenue, Ottawa, Canada, has devised a forced- draft water-oven for drying at temperatures between 60° and 90° C. The oven is heated by means of ordinary gas-burners, and the temperature is controlled by introducing at the bottom of the oven a blast of air from a blower run by a small water-motor. Before dis- ""; charging into the oven, the air-tube enters the water-chamber and is coiled a number of times in order to sufficiently warm the air before it enters the oven. The exit end of the air-tube is covered with a concavo-convex disk in order to distribute the blast and to pre' vent harmful currents. By regulating the burners and the flow of air, a fairly constant tem- perature can be obtained. The bottom of the oven is curved instead of flat, to prevent bumping when the water is boiling; a perforated plate serves as a false bottom, t U. S. P. lead subacetate, sometimes sold as Goulard's extract, may also be used. SUGAR AND SACCHARINE PRODUCTS. 587 Anhydrous lead subacetate, first proposed by Home,* may be sub- stituted for the sokition. Alumina Cream. — Divide a cold, saturated solution of alum into two unequal portions, add to the larger a slight excess of ammonia, then by degrees the remaining portion to faint acid reaction. Process. — If the Soleil-Ventzke polariscope is to be used, weigh out 26 grams of the sugar, which may conveniently be done in the German- FiG. 107. — German-silver Sugar-tray with Tare. silver, tared tray especially designed for this purpose (Fig. 107). If any other instrument is employed, weigh out the standard or normal weight for that instrument (see p. 583). Transfer the sugar by washing to a Fig. ioS. — A Convenient Sugar-scale. loo-cc. graduated sugar-flask, and if the solution is perfectly clear, as would be the case with a refined sugar, make up to the mark and shake to insure a uniform solution. If the solution is slightly turbid, or more or less opaque or dark-colored, a clarifier must be added before making up to the mark to obtain a clear solution for polarization. The kind and amount of clarifier to be used depends on the nature of the sugar solution and must be learned by experience. If the turbidity is only slight, from 5 to 10 cc. of alumina cream alone will often prove sufficient; if more opaque, 10 cc. of lead subacetate solution or a small amount of the dry salt may be used. * Jour. Am. Chem. Soc, 26, 1904, p. 1S6. 588 FOOD INSPECTION ^Nn y4hl/} LYSIS. For additional details as to clarification see page 614. under Molasses. After adding the clarifier, the flask is filled to the mark with water and shaken, the solution being poured upon a dry filter and the first uew cubic centimeters of the filtrate rejected. A 200-mm. observation- tube is filled with the clear sugar solution and the polarization noted. If sucrose is the only optically active substance present, the direct read- ing on the polariscope will indicate its percentage. Process 0} Inversion. — In the presence of invert or other sugars the normal solution as above prepared is subjected to inversion as follows: Free a portion of the solution from lead by treating with anhydrous sodium carbonate, sodium sulphate or potassium oxalate, filter, place 50 cc. in a loo-cc. flask, add 25 cc. of water and little by little, while rotating the flask, 5 cc. of 38.8% hydrochloric acid. Heat in a water bath at 70° C, so that the solution in the flask reaches 67° to 69° C. in two and one-half to three minutes. Maintain at 69° C. during seven to seven and one-half minutes, making a total time of heating of ten minutes. Remove the flask, cool the contents rapidly to 20° C, and dilute to 100 cc. Polarize this solution in a 200-mm. tube provided with a lateral branch and a water jacket, passing a current of water around the tube to maintain a temperature of 20° C. The inversion may also be accomplished by allowing a mixture of 50 cc. of the clarified solution, freed from lead, and 5 cc. of the acid to stand for 24 hours at not less than 20° C. or for 10 hours at not less than 25°. The sucrose is obtained by the following formula of Clerget, based on the rotation of cane sugar before and after inversion, j^_ ioo{a — b) o ) 142.66—^/2 where 5 = per cent of sucrose, a = direct polarization, & = invert polari' zation, and / = temperature. Note that if the direct polarization is to the right or positive, and the invert to the left or negative, then a — b would be the sum of the two polarizations. In many cases where it is almost impossible to obtain a colorless solution for polarization in the 200-mm. tube, a loo-mm. tube may be employed, and the readings multiplied by 2, or half the normal weight,* viz., 13 grams, of the sample may be taken and made up to 100 cc, the 200-mm. tube employed, and the readings multiplied by 2. * Wherever the term "normal weight" occurs hereafter will be meant, unless otherwise noted, the normal weight of sugar for the Soleil-Ventzke polariscope, viz., 26 grams, and by a "normal solution" will be meant 26 grams in 100 cc. of water at 20° C. Clerget's formula, as originally worked out by him, was not based on this normal weight, but oa 16.35 grams. It is, however, applicable to 26 grams. SUG^R AND SACCHARINE PRODUCTS. 589 The determination of sucrose by the Clerget formula is applicable to all mixtures of the common sugars excepting those in which lactose, or milk sugar, is present. Theory 0} Inversion. — On p. 565 a reaction is given showing that when sucrose is subjected to inversion by the action of dilute acids or of invertase or yeast it splits up into the two sugars dextrose and levulose, forming equal quantities of each. The dextrose is, however, dextro- rotary and the levulose laevorotary. Invert sugar is the term applied to the mixture of dextrose and levulose formed by the inversion of sucrose. The specific rotary power of sucrose varies so little with the temperature as to be regarded for practical purposes as constant. At 87° a solution of invert sugar polarizes at zero. This is due to the fact that the rotary power of levulose, unlike that of sucrose and dextrose, varies with the temperature. At from 87° to 88° the left-handed rotation of the levulose balances the right-handed rotation of the dextrose in the invert sugar, hence the zero reading. As the temperature decreases from 87°, the rotary power of the levulose proportionally increases, till at 0° the normal invert sugar solution would polarize 44° to the left of the zero. On these facts Clerget's formula (p. 58S) is based, assuming that a normal solution of pure cane sugar polarizes at -{- 100°, while after inversion the reading for 0° temperature would be —44° and would decrease half a degree for each degree in temperature above 0°. Thus at 20° the invert reading would be —34. Detection of Invert Sugar. — Methyl-blue Test. — This test depends on the decolorization of methyl blue by invert sugar. 20 grams of sugar are dissolved in water and made up to 100 cc. If the solution is not clear, sufficient subacetate of lead solution is added to clarify before makin- will reduce 10 cc. Fehling's solution. ( levulose ) cane sugar "J 0.0475 gram of \ after in- V will reduce 10 cc. Fehling's solution. version j SUGAR AND SACCHARINE PRODUCTS. 5915 0.0807 gram of maltose will reduce 10 cc. Fehling's solution. 0.067 gram of lactose " ** 10 cc. " ** Suppose, for example, a sample of brown sugar is to be examined for invert sugar. This class of sugar has usually from 2 to 6 per cent of invert sugar. Hence, if 10 grams of the sample are dissolved in 100 cc, the resulting solution will contain not more than 1% of invert sugar. Suppose 12.9 cc. of this 10% sugar solution were found by the above process to reduce 10 cc. of Fehling's solution. 10 cc. Fehling's solution are equivalent to 0.05 gram invert sugar. Therefore 12.9 cc. of the sugar solution contain 0.05 gram invert- sugar. 100 cc. sugar solution contain 10 grams sample, and 12.9 cc. contain 1.29 grams sample, the equivalent of 0.05 gram invert sugar. __ . . o.osXioo Hence per cent mvert sugar = — ^ =3-9- Gravimetric Fehling Processes.— In determining reducing sugars by gravimetric processes, a measured volume of the sugar solution is allowed to act upon a measured volume of hot Fehling's solution for a fixed time, thus forming cuprous oxide. This may be dried and weighed direct, but is more commonly converted either into cupric oxide by ignition, or into metallic copper by reduction with hydrogen or by electrolysis. In any case the sugar is calculated from the weight of the cuprous oxide, the cupric oxide, or the metallic copper (whichever method be used) by the employment of the proper factor, or by the use of tables compiled for the purpose. Note. — Much difference of opinion exists as to the best and most accurate Fehling gravimetric method to employ. For the determination of dextrose, the Association of Official Agricultural Chemists has given its approval to the Allihn method, wherein the cuprous oxide deposited is further reduced to metallic copper and the dextrose calculated from the copper by Allihn's table. The author for two reasons prefers the method of O'Sullivan as employed by Defren, with the use of the Defren tables, in accordance with which the reducing sugar is expressed in terms of its equivalence to cupric oxide, first because of its comparative simplicity, involving as it does less processes than the Allihn method (each additional process introducing a possible source of error), and, second, because the same method as carried out is applicable for the determination not only of dextrose, but also of maltose and lactose, Defren having worked out 5;4 FOOD INSPECTION AND /ANALYSIS. tables adapted for them all. Munsen and Walker* have also devised a simple method with accompanying tables, adapted, with a uniform system of procedure, to the determination of the various reducing sugars. In using the tables for dextrose, maltose, and lactose compiled by AUihn, Wein, and Soxhlet, the method employed must in each case be carried out in strict accordance to the minutest details adopted by each of the above authorities, and they are by no means uniform. The Defren-O'Sullivan Method. f — Mix 15 cc. of Fehling's copper solution, A (p. 591), with 15 cc. of the tartrate solution, B, in a quarter- liter Erlenmeyer flask, and add 50 cc. of distilled water. Place the flask and its contents in a boiling water bath and allow them to remain five minutes. Then run rapidly from a burette into the hot liquor in the flask 25 cc. of the sugar solution to be tested (which should contain not more than one-half per cent of reducing sugar). Allow the flask to remain in the boiling water bath just fifteen minutes after the addition of the sugar solution, remove, and with the aid of a vacuum filter the contents rapidly in a platinum or porcelain Gooch crucible containing a layer of prepared asbestos fiber about i cm. thick, the Gooch with the asbestos having been previously ignited, cooled, and weighed. The cuprous oxide precipitate is thoroughly washed with boiling distilled water till the water ceases to be alkaline. The asbestos used should be of the long-fibered variety, and should be specially prepared as follows: Boil first with nitric acid (specific gravity 1.05 to i.io), washing out the acid with hot water, then boil with a 25% solution of sodium hydroxide, and finally wash out the alkali with hot water. Keep the asbestos in a wide-mouthed flask or bottle, and transfer it to the Gooch by shaking it up in the water and pouring it quickly into the crucible while under suction. Dry the Gooch with its contents in the oven, and finally heat to dull redness for fifteen minutes, during which the red cuprous oxide is con- verted into the; black cupric oxide. If a platinum Gooch is used (and this variety is preferred by the writer), it may be heated directly over the low flame of a burner. If the Gooch is of porcelain, considerable care must be taken to avoid cracking the crucible, the heat being increased cautiously and the operation preferably conducted in a radiator or muffle. After oxidation as above, the crucible is transferred to a desiccator, cooled, and quickly weighed. From the milligrams of cupric oxide, calculate the milligrams of dextrose from the following table: , ^ — . — . ■ * U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 241. f t ]onx. Am. Chem. See, 18, 1896, p. 749, and Tech. Quart., 10, 1897, P- ^^7. SUGAR AND SACCHARINE PRODUCTS. 595 IDEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, AND LACTOSE. Milligrams of Cupric Oxide. Milligrams Milligrams Milligrams Milligrams of Cupric Oxide. Milligrams Mi'lligrams Milligrams of Dextrose. of Maltose. of Lactose. of Dextrosfe. of Maltose. of Lactose. 3° 13.2 21.7 18.8 80 35-4 58-1 SO- 5 31 13-7 22.4 19-5 81 35-9 58-9 51-1 32 14. 1 23.1 20.1 82 36-3 59-6 51-7 Z3 14.6 23-9 20.7 83 36.8 60.3 52-4 34 15.0 24.6 21.4 84 37-2 61. 1 53-0 35 15-4 25-3 22.0 85 37-7 61.8 53-6 36 15-9 26.1 22.6 86 38.1 62.5 54-3 37 16.3 26.8 23-3 87 38-5 (>5-?, 54-9 38 16.8 27-S 23-9 88 39-0 64.0 S5-5 39 17.2 28.3 24-5 89 39-4 64.7 56.2 40 17-6 29.0 25.2 90 39-9 65-5 56.8 41 18. 1 29-7 25.8 91 40.3 66.2 57-4 42 18.5 30-5 26.4 92 40.8 66.9 58.1 43 ■ 19.0 31.2 27.1 93 41.2 67.7 58-7 44 19.4 31-9 27-7 94 41.7 68.4 59-3 45 19.9 32-7 28.3 95 42.1 69.1 60.0 46 20.3 33-4 29.0 96 42.5 69.9 60.6 47 20.7 34-1 29.6 97 43-0 70.6 61.2 48 21 .2 34.8 30.2 98 43-4 71-3 61.9 49 21.6 35-5 30.8 99 43-9 72.1 62.5 50 22.1 36.2 31-5 100 44-4 72.8 63.2 51 22.5 37-0 32.1 lOI 44-8 73-5 63.8 . 52 23.0 37-7 32-7 102 45-3 74-3 64.4 53 23 4 38.4 ?,?,-i 103 45-7 75-0 65.1 54 23.8 39-2 34-0 104 46.2 75-7 65-7 55 24.2 39-9 34-6 105 46.6 76-5 66.3 56 24.7 40.5 35-2 106 47-0 77-2 67.0 57 25-1 41-3 35-9 107 47-5 77-9 67.6 58 25-5 42.1 36-5 108 48.0 78.7 68.2 59 26.0 42.8 37-1 109 48.4 79-4 68.9 60 26.4 43-5 37-8 no 48.9 80.1 69-5 61 26.9 44-3 38-4 III 49-3 80.9 70.1 62 27-3 45-0 39-0 112 49-8 81.6 70.8 63 27.8 45-7 39-7 113 50.2 82.3 71.4 64 28.2 46.5 40-3 114 50-7 83-1 72.0 65 28.7 47-2 40.9 "5 51-1 83-8 72-7 66 29.1 47-9 41.6 116 51-6 ■84.5 73-3 67 29-5 48.6 42.2 117 52-0 85-2 74.0 68 30.0 49-4 42.8 118 52-4 85-9 74-6 69 30-4 50.1 43-5 119 52-9 86.6 75-2 70 30-9 =;o.8 44.1 120 53-3 87-4 75-9 71 31-3 51.6 44-7 121 53-8 88.1 76.6 72 31.8 52-3 45-4 122 54-2 88.9 77-2 73 32-2 53-0 46.0 123 54-7 89.6 1l-9 74 32.6 53-8 46.6 124 55-1 90-3 78-5 75 3i--^ 54-5 47-3 125 55-6 91. 1 79. r 76 33-5 55-2 47-9 126 s6.o 91.8 79-8 77 34-0 56.0 48.5 127 56-5 92-5 80.4 78 34.4 56-7 49-2 128 56-9 93-3 81. r 79 34-9 -57-4- 49-8 129 57-3- 94.0 81.7 596 FOOD INSPECTION AND ANALYSIS. DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, AND l.\CTOSY.— {Continued). Milligrams of Cupric Oxide. Milligrams Milligrams Milligrams Milligrams of Cupric Milligrams Milligrams Milligrams of Dextrose. of Maltose. of Lactose. Oxide. of Dextrose. of Maltose. of Lactose. 130 57-8 94-8 82.4 180 80.4 131. 8 114. 6 131 58.2 95-5 83.0 181 80.8 132-5 115. 2 132 58.7 96.2 83.6 182 81.3 133-2 115.8 133 59-1 97.0 84.2 183 81.8 134-0 116. 5 134 59-6 97-7 84-9 184 82.2 134-7 117. 1 135 60.0 98-4 85-5 185 82.7 13S-5 117. 8 136 60.5 99-2 86.1 186 83.1 136.2 118. 4 137 60.9 99-9 86.8 187 83-5 136.9 119. 1 138 61.3 100.7 87.4 188 84.0 I.S7-7 119.7 139 61.8 101.4 88.1 189 84.4 138-4 120.4 140 62.2 102. 1 88.7 190 84.9 139-1 121.0 141 62.7 102.8 89-3 191 85-4 139-9 121.7 142 63.1 103-5 90.0 192 85-9 140.6 122.3 143 63.6 104-3 90.6 193 86.3 141-4 123.0 144 64.0 105.0 91-3 194 86.8 142. 1 123.6 ^45 64-5 105.8 91-9 195 87.2 142.8 124-3 146 64.9 106.5 92.6 196 87-7 143.6 124.9 147 65-4 107.2 93-2 197 88.1 144-3 125-6 148 6^.8 108.0 93-9 198 88.6 145-1 126.2 149 66.3 108.7 94-5 199 89.0 145-8 126.9 150 66.8 109.5 95-2 200 89.5 146.6 127-S 151 67-3 110.2 95-8 201 89.9 147-3 128.2 152 67.7 III.O 96.5 202 90.4 148.1 128.8 153 68.3 111.7 97-1 203 90.8 148.8 129-5 154 68.7 112.4 97-8 204 91-3 149-6 130.1 155 69.2 113.2 98-4 205 91.7 150-3 130-8 156 69.6 113-9 99.1 206 92.2 151. 1 131-5 157 70.0 114.7 99-7 207 92.6 151.8 132.1 158 70-5 115.4 100.4 208 93-1 152-5 132.8 159 70.9 116. 1 101. 209 93-5 153-3 133-4 160 71-3 116.9 101.7 210 94-0 154-1 134-1 161 71.8 117.6 102.3 211 94-4 154-8 134-7 162 72-3 118.4 103.0 212 94-9 155-6 135-4 163 72-7 119.1 103.6 213 95-3 156-3 136.0 164 73-2 119.9 104.3 214 95-8 157-1 136-7 165 73-6 120.6 104.9 215 96-3 157-8 137-3 166 74-1 121.4 105.6 216 96.7 158-6 138.0 167 74-5 122.1 106.2 217 97-2 159-3 138.6 168 74-9 122.9 106.9 218 97-6 160.0 139-3 169 75-4 123.6 107-5 219 98.1 160.8 139-9 170 75-8 124.4 108.2 220 98.6 161.5 140.6 171 76-3 125.1 108.8 211 99.0 162.3 141.2 172 76.8 125.8 109.5 222 99-5 163.0 141. 9 173 77-3 126.6 110. 1 223 99-9 163-7 142.5 174 77-7 127-3 no. 8 224 100.4 164.5 143-2 175 78.2 128.1 III. 4 225 100.9 165-3 143-8 176 78.6 128.8 112. 226 101.3 166.0 144-S 177 79.1 129-5 112. 6 227 101.8 166.8 145 -I 178 79-5 130-3 ^T-i-i 228 102.2 167.5 145.8 179 80.0 131. 113-9 229 102.7 168.3 146.4 SUGAR AND SACCHARINE PRODUCTS. 597 DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, AND 1.ACTOSE— (Concluded). Milligrams of Cupric Oxide. Milligrams Milligrams Milligrams Milligrams of Cupric Milligrams Milligrams Milligrams of Dextrose. of Maltose. of Lactose. 0.xide. of Dextrose. of Maltose. of Lactose. 230 103. 1 169.1 147.0 280 126.1 206.8 179-6 231 103.6 169.8 147-7 281 126.5 207-5 180.2 232 104.0 170.6 148.3 282 127.0 208.3 180.9 233 104-5 17I-3 149.0 283 127.4 209.0 181.5 234 105.0 172. 1 149.6 284 127.9 209.8 182.2 23s 105.4 172.8 150-3 285 128.^ 210.5 182.9 236 105.9 173-6 150-9 286 128.8 211. 3 183.6 237 106.^ 174-3 151.6 287 129.3 2X2. I 184.2 238 106.8 175-1 152.2 288 129.7 212.8 184-9 239 107.2 175-8 152-9 289 130.2 213.6 185.6 240 107.7 176.6 153-5 290 130.6 214-3 186.2 241 108.1 177-3 154-2 291 131-1 215.1 186.9 242 108.6 178. 1 154-8 292 131-5 215-9 187.6 243 ■ 109.0 178.8 155-5 293 132.0 216.6 188.2 244 109.5 179.6 156.1 294 132-5 217.4 188.9 245 109.9 180.3 156.8 295 133-0 218.2 189.5 246 110.4 181.1 157-4 296 133-4 218.9 190.2 247 110.9 181. 8 158.1 297 133-9 219.7 190.8- 248 111.3 182.6 158.7 298 134-3 220.4 191-5 249 III. 8 183-3 159-4 299 134-8 221.2 192.1 250 112.3 184.1 160.0 300 135-3 221.9 192.8 251 112. 7 184.8 160.7 301 135-7 222.7 193-4 252 113.2 185-5 161.3 302 136.2 223-5 194. 1 253 II3-7 186.3 162.0 303 136.6 224.2 194.7 254 114.1 187.1 162.6 304 137-1 225.0 195-3 255 114.6 187.8 ^(>3-3 305 137-6 225.8 196.0 256 115.0 188.6 163.9 306 138.0 226.5 196.6 257 "5-5 189.3 164.6 307 138-5 227.3 197-3 258 116.0 190. 1 165.2 308 138.9 228.1 197.9 259 116.4 190.8 165.9 309 139-4 228.8 198.6 260 116. 9 191.6 166.5 310 139-9 229.6 199-3 261 117-3 192.4 167.2 311 140-3 230-4 199.9 262 117.8 193- 1 167.8 312 140.8 231.1 200.6 263 118.3 193-9 168.1 313 141.2 231.9 201.3 264 118. 7 194.6 169.5 314 141.7 232.7 202.0 265 119. 2 195.4 169.8 315 142.2 233-4 202.6 266 119. 6 196. 1 170.4 316 142.6 234.2 203-3 267 120.1 196.9 171.1 317 143-1 234-9 203.9 268 120.6 197.7 171.7 318 143.6 235-7 204.6 269 121.0 198.4 172.4 319 144.0 236.5 205-3 270 121.4 199.2 173-0 320 144-5 237.2 205.9 271 121.9 199.9 173-7 272 122.4 200.7 174-4 273 122.8 201.5 175-0 274 123-3 202.2 175-7 275 123-7 203.0 176.3 276 124.2 203.7 177.0 277 124.6 204.5 177.6 278 125.1 20^.2 178-3 279 12=;. 6 206.0 T78.0 . .^ 598 FOOD INSPECTION AND ANALYSIS Munson and Walker Method.* — i. Preparation of Solutions and Asbestos.— Vse the copper sulphate solution and alkaline tartate solution as given on page 591. Prepare the asbestos, which should be the amphibole variety, by first digesting with 1 13 hydrochloric acid for two or three days. Wash free from acid, and digest for a similar period with soda solution, after which treat for a few hours with hot alkaline copper tartrate solution of the strength employed in sugar determinations. Then wash the asbestos free from alkah, finally digest with nitric acid for several hours, and after washing free from acid, shake with water for use. In preparing the Gooch crucible, load it with a film of asbestos one-fourth inch thick, wash this thoroughly with water to remove fine particles of asbestos; finally wash with alcohol and ether, dry for thirty minutes at 100° C, cool in a desiccator and weigh. It is best to dissolve the cuprous oxide with nitric acid each time after weighing, and use the same felts over and over again, as they improve with use. 2. Process. — Transfer 25 cc. each of the copper and alkaline tartrate solutions to a 400-cc. Jena or Non-sol beaker, and add 50 cc. of reducing sugar solution, or, if a smaller volume of sugar solution be used, add water to make the final volume 100 cc. Heat the beaker upon an asbestos gauze over a Bunsen burner, so regulate the flame that boiling begins in four minutes, and continue the boiling for exactly two minutes. Keep the beaker covered with a watch-glass throughout the entire time of heating. Without diluting, filter the cuprous oxide at once on an asbestos felt in a porcelain Gooch crucible, using suction. Wash the cuprous •oxide thoroughly with water at a temperature of about 60° C., then with 10 cc. of alcohol, and finally with 10 cc. of ether. Dry for thirty minutes in a water oven at 100° C., cool in a desiccator and weigh as cuprous oxide. The number of milligrams of copper reduced by a given amount of reducing sugar differs when sucrose is present and when it is absent. In the tables on pp. 599 to 607 the absence of sucrose is assumed, except in the two columns under invert sugar, where one for mixtures of invert sugar and sucrose (0.4 gram of total sugar in 50 cc. of solution), and one for invert sugar and sucrose when the 50 cc. of solution contains 2 grams of total sugar are given, in addition to the column for invert sugar alone. * Jour. Am. Chem. Soc, 28, 1906, p. 163; 29, 1907, p. 541; U. S. Dept. Agric, Bur. of Chem., Bui. 107 (rev.), p. 241; Circ. 82. SUGAR AND SACCHARINE PRODUCTS. 599 MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND MALTOSE. [Weights in milligrams.] o Invert Sugar and Sucrose. Lactose. Maltose. B B O • V H ,_ d d V O '3 c £ 3 CM X K X X w 3 u Q 6 IN CJ u u lO 8.9 4.0 4-5 1.6 3.8 3.9 4.0 59 6.2 10 III 9.8 4-5 5-0 2 . 1 4.5 4.6 4-7 6.7 7.0 II 12 10.7 4-9 5-4 2.5 S.I 5.3 5.4 7.5 7.9 12 13 ii-S 5-3 5.8 3.0 5.8 5.9 6.1 8.3 8.7 13 14 12.4 5-7 6.3 3.4 6.4 6.6 6.8 9.1 95 14 IS 13-3 6.2 6.7 3-9 7.1 7.3 7 . 5 9.9 10. 4 IS i6 14.2 6.6 7.2 4.3 7.8 8.0 8.2 10.6 II . 2 16 17 IS-I 7.0 7.6 4.8 8.4 8.6 8.9 II. 4 12.0 17 i8 16 . 7-5 8.1 5.2 9.1 9.3 9.S 12.2 12.9 18 19 16.9- 7-9 8.5 5.7 9-7 lO.O 10.2 13.0 13.7 19 20 17.8 8.3 8.9 6.1 10.4 10.7 10.9 13.8 14.6 20 2 1 18.7 8.7 9-4 6.6 II. II. 3 II. 6 14 . 6 15.4 21 J22 195 9.2 9.8 7.0 II. 7 12.0 12.3 15.4 16.2 22 23 20.4 9.6 10.3 7.5 12.3 12.7 13.0 16.2 17.1 23 •2 4 21.3 10. 10.7 7.9 13.0 13.4 13.7 17.0 17.9 24 as 22 . 2 10. 5 II . 2 8.4 13.7 14.0 14.4 17.8 18.7 25 36 231 10.9 II. 6 8.8 14.3 14.7 15. I 18.6 19.6 26 27 24.0 II-3 12 .0 9.3 ISO IS. 4 IS. 8 19.4 20.4 27 28 24-9 11.8 12. s 9.7 IS. 6 16. 1 16. S 20. 2 21.2 28 39 2S.8 12 . 2 12 . 9 10. 2 16.3 16.7 17. I 21.0 22 . 1 29 30 26.6 12.6 13.4 10.7 4.3 16.9 17.4 17.8 21.8 22 . 9 30 31 27-S I3-I 13.8 II . I 4.7 17.6 18. I 18.5 22 . 6 23.7 31 32 28.4 13s 14.3 II. 6 5-2 18.3 18.7 19.2 23.3 24.6 32 33 293 13-9 14.7 12 .0 . S.6 18.9 19.4 19.9 24.1 25.4 33 34 30.2 14-3 IS. 2 12. S 6.1 19.6 20. 1 20.6 24.9 26. 2 34 3S 311 14.8 15.6 12.9 6.S 20.2 20.8 21.3 25.7 27.1 35 36 32.0 152 16. I 13.4 7.0 20.9 21.4 22 .0 26. s 27.9 36 37 32.9 15-6 16. s 13-8 7.4 21.5 22. 1 22.7 27.3 28.7 37 38 33.8 16. 1 16.9 14-3 7-9 22.2 22.8 23.4 28.1 29.6 38 39 34-6 16.5 17.4 14.7 8.4 22.8 23. S 24.1 28.9 30.4 39 40 35-5 16.9 17.8 15.2 8.8 23-5 24.1 24.8 29.7 31.3 40 41 36.4 17.4 18.3 15.6 9.3 24.2 24.8 2S.4 30. S 32.1 41 42 37-3 17.8 18.7 16. 1 9-7 24.8 25. S 26.1 31.3 32.9 42 43 38.2 18.2 19. 2 16.6 10.2 2S.5 26.2 26.8 32.1 33.8 43 44 391 18.7 ig . 6 17.0 10.7 26. I 26.8 27.5 32.9 34.6 44 4S 40.0 19. I 20. 1 17.5 II . I 26.8 27. 5 28.2 33.7 35. 4 45 46 40.9 19.6 20. s 17.9 II. 6 27.4 28.2 28.9 34.4 36.3 46 47 41-7 20.0 21.0 18.4 12 .0 28.1 28.9 29.6 3S.2 37.1 47 48 42 .6 20. 4 21.4 18.8 12. s 28.7 29.5 30.3 36.0 37.9 48 49 43 -S 20.9 21.9 19.3 12.9 29.4 30.2 31.0 36.8 38.8 49 SO 44-4 21.3 22.3 19.7 13.4 30.1 30.9 31-7 37.6 39.6 50 SI 45 -3 21.7 22.8 20 . 2 13.9 30.7 31-5 32.4 38.4 40.4 SI S2 46. 2 22 .2 23.2 20. 7 14.3 31.4 32.2 33.0 39.2 41.3 52 S3 47-1 22 .6 23.7 21 . I 14.8 32.1 32.9 33.7 40.0 42.1 S3 S4 48.0 23.0 24.1 21 .6 15.2 32.7 33.6 34-4 40.8 42.9 54 SS 48.9 23-5 24.6 22 .0 15.7 33-4 34.3 35-1 41 .6 43.8 SS S6 49-7 239 25.0 22. s 16.2 34-0 34.9 35.8 42.4 44.6 S6 57 SO. 6 24.3 25.5 22 .9 16.6 34-7 35.6 36. 5 43.2 45-4 57 S8 SI-S 24.8 25.9 23.4 17. 1 35. 4 36.3 37.2 44.0 46.3 58 S9 52-4 25.2 26.4 23.9 17.5 36.0 37.0 37.9 44.8 47.1 59 60 S3-3 25.6 26.8 24.3 18.0 36.7 37:6 38.6 45.6 48.0 60 61 54-2 26.1 273 24.8 18.5 37-3 38.3 39.3 46.3 48.8 6r 62 55- I 26.5 27.7 25.2 18.9 38.0 39 40.0 47.1 49.6 62 63 56.0 27.0 28.2 25-7 19.4 38.6 39.7 40.7 47.9 SO.S 63 64 S6.8 27.4 28.6 26. 2 19.8 39.3 40.3 41.4 48.7 SI. 3 64 Ooo FOOD INSPECTION AND ANALYSIS. MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND MALTOSE— (Co«/iwMcrf). [Weights in milligrams.] o Invert Sugar and Sucrose. Lactose. Maltose. d 3 3 o d u 3 H n) •*> ■ + + X + "2 3 t-i 2 CO E rt 6 d 3 o 0) U ,": M c3 M S3 s a 0- a 53 3 " 3 £ ffi S X X u a 3 o Q 6 '^ u c5 u 65 57-7 27.8 29.1 26.6 20.3 40.0 41 .0 42.1 49-5 •52. I 6S 66 S8.6 28.3 29-5 27. 1 20.8 40.6 41-7 42.8 50.3 S3.0 66 67 S9S 28.7 30.0 27.5 21,2 41-3 42.4 43. s 511 53.8 67 68 60. 4 29.2 30.4 28.0 21 .7 41.9 43. I 44-2 SI. 9 54-6 68 69 61.3 29. 6 30.9 28.5 22 . 2 42.6 43-7 44.8 52.7 55.5 69 70 62 . 2 30.0 31-3 28.9 22.6 43.3 44-4 45-5 53.5 56.3 70 71 63.1 30.5 31.8 29.4 23.1 43.9 45.1 46.2 54. 3 57.1 71 72 64.0 30.9 32-3 29.8 23. s 44.6 45.8 46.9 55. I 58.0 72 73 64.8 31 -4 32.7 30.3 24.0 45.2 46.4 47.6 55-9 58.8 73 74 65.7 31.8 33-2 30.8 24. s 45.9 47-1 48.3 56.7 59.6 74 75 66.6 32.2 33.6 312 24.9 46.6 47.8 43.0 57-5 60.5 7S 76 67.5 32-7 34-1 31-7 254 47.2 48. 5 49.7 58.2 61.3 76. 77 68.4 33-1 345 32.1 25.9 47-9 49.1 SO. 4 59.0 62.1 77 78 693 33.6 350 32.6 26.3 48.5 49.8 511 S9.8 63 78 79 70.2 34.0 35-4 33 I 26.8 49.2 50.5 SI. 8 60.6 63.8 79 80 71. 1 34.4 35-9 33-5 27-3 49-9 51.2 52.5 61 .4 64.6 80 81 71.9 34.9 36.3 34.0 27.7 50. 5 SI. 9 53 2 62 . 2 OSS 81 82 72.8 35-3 36.8 34-5 28.2 51-2 52.5 S3. 9 63.0 66.3 82 83 73.7 35.8 37-3 34-9 28.6 51.8 53-2 54-6 63.8 67.1 83 84 74.6 36.2 37-7 35-4 29.1 52.5 53.9 55-3 64.6 68.0 84 8S 75-5 36.7 38.2 35.8 29 . 6 53. I 54-6 S6.o 65.4 68.8 8S 86 76.4 37-1 38.6 36.3 30. 53.8 55.2 S6.6 66.2 69.7 86. 87 77-3 37.5 39-1 36.8 30.5 54-5 55.9 57.3 67 .0 70. 5 87 88 78.2 38.0 39.5 37-2 310 55- I S6.6 58.0 67.8 71.3 88 89 79.1 38.4 40 .0 37.7 31.4 55.8 57-3 S8.7 68.5 72 . 2 89 90 79.9 38.9 40.4 38.2 31-9 56.4 58.0 59-4 69 .3 73.0 90. 91 80.8 39-3 40.9 38.6 32.4 57. I 58.6 60. I 70. I 73-8 91 92 81.7 39.8 41 .4 39.1 32.8 57.8 59-3 60.8 70.9 74-7 92 93 82.6 40. 2 41 .8 39.6 33-3 S8.4 60.0 61. S 71 -7 75-5 93 94 83.5 40. 6 42.3 40.0 33.8 59.1 60.7 62.2 72.5 76.3 94 95 84.4 41. I 42.7 40.5 34-2 59.7 61.3 62 .9 73.3 77.2 95 96 85.3 41-5 43-2 41 .0 34.7 60.4 62 .0 63.6 74. I 78.0 96. 97 86.2 42 .0 43-7 41 .4 35.2 61. I 62.7 64.3 74-9 78.8 97 98 87.1 42.4 44.1 41.9 35.6 61.7 63 -4 65.0 75.7 79.7 98 99 87.9 42.9 44.6 42.3 36.1 62.4 64.0 6s.-' 76.5 80. 5 99 TOO 88.8 43-3 450 42.8 36.6 63.0 64.7 66.4 77-3 81.3 100 lOI 89.7 43-8 45-5 43-3 37.0 63.7 65.4 67.1 78.1 82.2 lOI 102 90.6 44.2 46.0 43.8 37-5 64.4 66.1 67.8 78.8 83.0 102 103 91. S 44-7 46.4 44.2 38.0 65.0 66.7 68,5 79.6 83.8 103 104 92.4 45-1 46.9 44.7 38. S 65.7 67.4 69. I 80.4 84.7 104 los 93-3 45-5 47-3 45-2 38.9 66.4 68.1 69.8 81.2 85 . 5 105 106 94.2 46.0 47-8 45-6 39-4 67.0 68.8 70. 5 82.0 86.3 106 107 95 46.4 48.3 46 . I 39-9 67.7 69 5 71.2 82 . 8 87.2 107 108 95. 9 46.9 48.7 46.6 40.3 68.3 70.1 71.9 83.6 88.0 108 109 96.8 47.3 49.2 47.0 40.8 69.0 70.8 72.6 84.4 88.8 109 110 97-7 47.8 49-6 47-5 41.3 69.7 71.5 73.3 85.2 89.7 1 10 I II 98.6 48.2 50.1 48.0 41-7 70.3 72.2 74-0 86 .0 90.5 III 112 99.5 48.7 50.6 48.4 42.2 71.0 72.8 74-7 86.8 91.3 112 113 100 . 4 49. I 510 48.9 42.7 71.6 73 5 75-4 87 .6 88.4 92 . 2 113 114 101 .3 49.6 51-5 49-4 43-2 72.3 74-2 76.1 93 114 115 102 . 2 50.0 51.9 49.8 43.6 73-0 74-9 76.8 89.2 93.9 IIS 116 103.0 50.5 52.4 SO. 3 44- I 73.6 75.6 77.5 90.0 94.7 116 117 103.9 50.9 52.9 SO. 8 44-6 74-3 76. 2 78.2 90.7 95. 5 117 118 104.8 51 -4 53 • 3 Si-2 45.0 75-0 76.9 78.9 91 S 96.4 I iS 119 105.7 SI. 8 53.8 Si-7 45. 5 75.6 77.6 79.6 92.3 97.2 119 SUGAR AND SACCHARINE PRODUCTS 60 1 MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND 'WIM.TOSY.— {Continued). [Weights in milligrams.] Invert Sugar and Sucrose. Lactose. Maltose. Q 5 3 d V "fi _ d •a ■>< 3 V 3 ?5 u X Hci + + X + •a a u 2 n! 6 s, q 6 Q 6 Q 3 k4 S 00 ?i a ti ^ a 04 0. X 01 9 cSc^ ffi s X X X a 3 CJ Q d cs 6 C u 120 106.6 52.3 54-3 52 .2 46.0 76.3 78.3 80.3 93-1 98.0 120 121 107.5 52-7 54-7 52.7 46. 5 76.9 79.0 81.0 93-9 98.9 121 122 108.4 53-2 55-2 53-1 46.9 77.6 79.6 81.7 94-7 99-7 123 123 I09-3 53-6 55-7 53-6 47.4 78.3 80.3 82.4 95-5 100 . 5 123 124 no. I 54-1 56.1 54-1 47.9 78.9 81.0 83.1 96-3 lOI .4 124 12s 1 1 1 .0 54-5 56.6 545 48.3 79.6 81.7 83.8 97- I 102 . 2 I2S 126 1 1 1 .9 55-0 57.0 55-0 48.8 80.3 82.4 84-5 97 9 103.0 126 127 112. 8 55-4 57-5 55-5 49-3 80.9 83.0 85-2 98.7 103-9 127 128 113. 7 55-9 58-0 55-9 49-8 81.6 83.7 85-9 99-4 104.7 128 *29 1 1 4 . 6. 56.3 58.4 56-4 SO. 2 82.2 84-4 86.6 100 . 2 105.5 129 130 115. 5 56.8 58.9 56.9 50.7 82.9 8S.1 87.3 lOI .0 106. 4 130 131 116. 4 57-2 59-4 57-4 51. 2 83.6 85.7 88.0 IOI.8 107 . 2 131 132 II7-3 57-7 59-8 57-8 51-7 84.2 86.4 88.7 102 .6 108.0 132 ■^ii 118. I 58.1 60.3 58-3 52. I 84-9 87.1 89.4 103-4 108.9 133 134 1190 58.6 60.8 58.8 52.6 85-5 87.8 90. I 104. 2 109.7 134 13s. 119. 9 59-0 61.2 59-3 53-1 86.2 88.5 90.8 105 .0 110.5 13s 136 120.8 59-5 61.7 59-7 53.6 86.9 89. 1 91.5 105.8 1 1 1 . 4 136 137 I2r.7 60 .0 62.2 60 . 2 54-0 87.5 89.8 92.1 106 .6 112 . 2 137 138 122 .6 60. 4 62 .6 60 . 7 54-5 88.2 90. s 92.8 107.4 113. 138 139 123.5 60 . 9 63.1 61.2 55-0 88.9 91.2 93. S 108.2 113 9 139 140 124.4 61.3 63.6 61.6 55-5 89. 5 91.9 94-2 109 . 114.7 140 141 125.2 61.8 64.0 62.1 55-9 90.2 92. 5 94-9 109. 8 115.5 141 142 126. I 62.2 64.5 62.6 56-4 90.8 93-2 95-6 no . 5 116.4 142 143 127.0 62.7 65 .0 63.1 56.9 91-S 93-9 96.3 III. 3 H7.2 143 144 127.9 63.1 65-4 63-5 57.4 92.2 94-6 97.0 1 12 . I 118. 144 145 128.8 63.6 65-9 64 .0 57-8 92.8 95.3 97-7 112. 9 118.9 I4S 146 129.7 64.0 66.4 64.5 58.3 93 S 95 -9 98-4 113-7 119. 7 146 147 i30.6 64. 5 66.9 65 .0 58.8 94.2 96.6 99-1 114-S 120. s 147 148 131. 5 65 .0 67.3 65-4 59.3 94.8 97-3 99-8 115-3 121 .4 148 149 132.4 65-4 67.8 65.9 59-7 95-5 98.0 100. S 116. I 122 . 2 149 150 1332 6s-9 68.3 66.4 60.2 96. I 98.7 lOI . 2 116. 9 123.0 150 JSI 134-1 66.3 68.7 66.9 60. 7 96.8 99-3 lOI .9 117. 7 123-9 151 152 1350 66.8 69 . 2 67.3 61.2 97-5 100. 102.6 118. 5 124.7 152 IS3 135-9 67.2 69.7 67.8 61.7 98. I 100.7 103.3 II9-3 I2S-S 153 154 136.8 67.7 70 . I 68.3 62.1 98.8 lOI .4 104.0 120.0 126.4 154 155 137.7 68.2 70.6 68.8 62.6 99.5 102. I 104.7 120.8 127 . 2 15s 156 138.6 68.6 71. 1 69. 2 63 -t 100. I 102.8 ioS-4 121 .6 128.0 156 157 139-5 69. r 71.6 69. 7 63.6 100.8 103-4 106. I 122.4 128.9 157 158 140.3 69 -5 72.0 70.2 64 . I 101. 5 104. I 106.8 123.2 129.7 158 159 141 .2 70.0 72.5 70.7 64.5 102. 1 104.8 107. S 124.0 130. 5 159 160 142 . I 70.4 73-0 71 .2 65 .0 102.8 105- 5 108.2 124.8 131 .4 1 60 161 1430 70.9 73-4 71.6 65-5 103-4 106. 2 108.9 125.6 132 .2 i6r 162 143-9 71 .4 73-9 72.1 66.0 104. I 106.8 109.6 126.4 133-0 162 163 144-8 71.8 74-4 72.6 66.5 104.8 107 -S no. 3 127.2 133-9 163 164 145-7 72.3 74-9 73-1 66.9 105-4 108.2 II 1 .0 128.0 134-7 164 i6s 146.6 72.8 75-3 73-6 67-4 106. I 108 .9 III. 7 128.8 135-5 i6s 166 147-5 73-2 75-8 740 67.9 .106.8 '107.4 109.6 112. 4 129.6 136-4 166 167 148.3 73.7 76.3 74-5 68.4 no. 3 113-I 130.3 137-2 167 168 149-2 74-1 76.8 75-0 68.9 108.1 no. 9 113. 8 1311 133-0 168 169 150. I 74.6 77.2 75-5 69-3 108.8 III .6 II4-S 131.9 138.9 169 170 151.0 75-1 77-7 76.0 69-8 109.4 112. 3 nS-2 132.7 139.7 170 171 151.9 75-5 78.2 76.4 70-3 no. I 1130 115.9 133-5 140. 5 171 172 152.8 76.0 78.7 76.9 70.8 no. 8 II3-7 116. 6 134-3 141-4 171 173 153-7 76.4 79-1 77.4 71 3 III. 4 114.3 117.3 I3S-I 142 . 2 173 174 154.6 76.9 . 79.6 77.9 71-7 112. 1 ns.o 118. 135-9 143 174 602 FOOD INSPECTION AND ANALYSIS. MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND MMfTOSY.— (Continued). [Weights in milligrams.] q Invert Sugar and Sucrose. Lactose. Maltose. 3 3 c c ■3 _- d d •d O 3 6 H 6 + 6 X + 6 6 4- 6 •0 2 p. 3 a u > 0^ 0^ IS ?! 5i ?! 1 a 3 O Q d •^ d C u c C I7S IS5-S 77-4 80.1 78.4 72.2 112. 8 IIS. 7 118. 7 136.7 143-9 17 "rt ^^ d d ! r 3 a a 1) 4) > 3 I-. 3 0^ ffi £ ffi ffi X 3 U Q d N 6 u 6 u 6 230 204.3 103.2 106 .6 105.2 99-1 149.4 153-3 157.2 180.2 189.7 230 231 205.2 103 -7 107 . I 105-7 99-6 150-0 I54-0 157.9 181.0 190. 5 231 232 206 . 1 104. I 107 .6 106. 2 100. 1 150.7 154-7 158.6 181.8 191-3 232 233 207 .0 104 . 6 108. I 106 . 7 100. 6 151-4 155-4 159.3 182.6 192 . 2 233 234 207.9 105 . 1 108.6 107 . 2 101 . 1 152.0 156. 1 160.0 183.4 193-0 234 235 208.7 105.6 109 . I 107-7 loi .6 152.7 156.7 160.7 184.2 193-8 235 236 209 . 6 106.0 109-5 108.2 102 . 1 153.4 157.4 161 .4 184.9 194-7 236 237 210. s 106. s 1 10 .0 108.7 102 .6 154-0 158. 1 162. 1 185.7 195-5 237 238 211 . 4 107 .0 no. 5 109. 2 103.1 IS4-7 158.8 162.8 186. 5 196.3 238 239 212.3 107-5 I II .0 109 .6 103 -5 IS5-4 159-5 163-S 187.3 197.2 239 240 213.2 108.0 III. 5 no. I 104.0 156. I 160.2 164-3 188.1 198.0 240 241 214. 1 108.4 1 12 .0 no. 6 104-5 156.7 160.9 165.0 188.9 198.8 241 242 215.0 :o8.9 112. 5 III . I 105.0 157-4 161. 5 165.7 189.7 199-7 242 243 215.8 109.4 113-0 II 1 . 6 105-5 158. I 162.2 166.4 190.5 200. 5 243 244 216.7 109.9 113-S 112 . 1 106.0 158.7 162.9 167 . 1 191-3 201 .3 244 e4S 217.6 no. 4 114. 112.6 106. 5 159.4 163.6 167.8 192 . 1 202 . 2 245 246 218. 5 no. 8 114-S II3-I 107 .0 160. I 164-3 168. 5 192.9 203.0 246 247 219.4 III. 3 115-0 113-6 107-S 160.7 165.0 169. 2 193-6 203.8 247 248 220.3 III. 8 1 1 5 - 4 114.1 108.0 161 .4 165.7 169.9 194.4 204.7 248 249 221.2 112. 3 lIS-9 114. 6 108. s 162. 1 166.3 170.6 195.2 205-5 249 250 222 . 1 112. 8 116. 4 115-1 109.0 162.7 167.0 171-3 196.0 206.3 250 251 223.0 113 . 2 116. 9 115.6 109-5 163.4 167.7 172.0 196.8 207 . 2 251 2S2 223.8 113. 7 II7-4 116.1 no.o 164. I 168.4 172.7 197.6 208 .0 252 2 53 224.7 1 14 . 2 I17-9 116.6 no. 5 164.7 169. 1 173.4 198.4 208.8 253 254 225 .6 114. 7 118. 4 117. 1 in .0 165.4 169.8 174-I 199.2 209.7 254 ess 226.5 115.2 118. 9 117.6 iii.s 166. I 170.5 174-8 200.0 210.5 255 256 227.4 115. 7 119. 4 118.1 112 .0 166.8 171. 1 175-5 200.8 211.3 256 2S7 228.3 116. 1 119. 9 118.6 112.5 167.4 171. 8 176. 2 201 .6 212.2 257 2S8 229.2 116. 6 120.4 119. 1 113-0 168. I 172.5 176.9 202.3 213.0 258 2S9 230.1 117. 1 120.9 119.6 113.5 168.8 173.2 177.6 203.1 213.8 259 J 60 231.0 117. 6 121 .4 120. 1 114.0 169-4 173-9 178.3 203.9 214-7 260 261 231.8 118. 1 121 .9 120.6 114-5 170. I 174-6 179.0 204.7 21S-5 261 262 232.7 118. 6 122.4 121 . 1 115.0 170.8 I7S-3 179.8 205.5 216.3 262 263 233.6 119. 122 . 9 121 .6 115-S 171. 4 176.0 180. s 206.3 217.2 263 264 234.5 119. 5 123-4 122 . 1 n6.o 172. I 176.6 181. 2 207. 1 218.0 264 265 235.4 120.0 123-9 122 .6 116.5 172.8 177-3 181. 9 207.9 218.8 26s 266 236.3 120. 5 124.4 123. 1 117.0 I73-S 178.0 182.6 208.7 219.7 266 267 237.2 121 .0 124.9 123.6 117-5 174-I 178.7 183.3 209.5 220.5 267 268 238.1 121. 5 125-4 124. 1 118.0 174-8 179.4 184.0 210.3 221.3 268 269 238.9 122 .0 125-9 124.6 118. 5 175-5 180. I 184.7 ^n .0 222 . 1 269 270 239.8 122 . 5 126.4 125. 1 119.0 176. I 180.8 185-4 211.8 223.0 270 271 240.7 122.9 126.9 125.6 119-S 176.8 181. 5 186. 1 212.6 223.8 271 272 241 .6 123-4 127-4 126. 2 120.0 177.5 182. I 186.8 213.4 224.6 272 273 242.5 123.9 127.9 126. 7 120.6 178. I 182.8 187-S 214.2 225.5 273 2 74 243.4 124.4 128.4 127 .2 121.1 178.8 183.5 188.2 215.0 226.3 274 27 s 244.3 124.9 128.9 127.7 121 .6 179.5 184.2 188.9 215.8 227.1 275 276 245-2 125-4 129-4 128.2 122 . 1 180.2 184.9 189.6 3^6.6 228.0 276 a^^ 246. 1 125-9 129.9 128.7 122.6 180.8 185-6 190.3 217.4 228.8 277 ?78 246.9 126.4 130.4 129. 2 123.1 181.5 186.3 191. 218.2 229. 6 278 ?79 • 247.8 126.9 130.9 129.7 123.6 182.2 187.0 191-7 218.9 230.5 279 280 248.7 1-27.3 131. 4 130.2 124. 1 182.8 187.7 192 . 4 219.7 231-3 28a 281 249.6 127.8 131. 9 130.7 124.6 183. 5 188.3 193. 1 220.5 232.1 281 282 250. 5 128.3 132.4 131.2 125. 1 184.2 189.0 193.9 221.3 233-0 282 283 251.4 128.8, 132.9 131.7 12 5 - 6 184.8 189 . 7 194 - 6 222 . I 233-8 283 a84 252.3 129-3 133-4 132.2 t26. I I8S-S 190.4 195-3 222 .9 234.6 2 84 6o4 FOOD INSPECTION AND ANALYSIS. MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND MM-IlOS^— {Continued). [Weights in milligrams.] f Invert Sugar and Sucrose. Lactose. Maltose. d d q 3 9i o d 2 a 3 u a a i 2 X u •a 00 3 u V > 1 3 ■3 0^ i + + 6 X X + 6 Si X ■a 01 3 2 a 3 3 Q C d f, 6 6 CJ 28s 2S3-2 129.8 133-9 132-7 126.6 186.2 i 191 . 1 196.0 223.7 235-5 285 286 254.0 130.3 134-4 133-2 127.1 186.9 ' 191. 8 196.7 224.5 236.3 286 287 2549 130.8 134-9 133-7 127 .6 187 -S 192. 5 197-4 225.3 237-1 287 288 255-8 131 -3 135-4 134-3 128. 1 188.2 193.2 198. I 226 . 1 1 238.0 288 289 256.7 131-8 135-9 134.8 128.6 188.9 193.8 1 198.8 226 . 9 238.8 289 290 2576 132-3 136.4 135-3 129. 2 189.5 194- S 199-5 227 .6 239.6 290 291 258.5 132-7 136-9 135.8 129.7 190.2 I9S-2 200.2 228.4 240.5 291 292 259-4 133-2 137-4 136.3 130.2 190.9 195.9 ! 200 . 9 229 . 2 241-3 292 293 260.3 133-7 137-9 136-8 130.7 I9I-5 196.6 201.6 230.0 242 . 1 293 294 261 .2 134-2 138-4 137-3 131.2 192.2 197-3 202.3 230.8 242 .9 294 29s 262 .0 134-7 138.9 137-8 131. 7 192.9 198.0 203.0 231 .6 243-8 29s 296 262 . 9 135-2 139-4 138.3 132 .2 193.6 198.7 203.7 232.4 244.6 296 297 263.8 135-7 140.0 138.8 132.7 194.2 199-3 204.4 233.2 245.4 297 298 264.7 136-2 140.5 139-4 133.2 194.9 200.0 ' 205. I 234.0 246.3 298 299 265.6 136.7 141 .0 139-9 133.7 195-6 200.7 205.8 234.8 247.1 299 300 266.5 137-2 141 -5 140.4 134.2 196.2 201.4 206.6 235. 5 247.9 300 301 267.4 137-7 142 .0 140.9 134.8 196.9 202. I 207.3 236.3 248.8 301 302 268.3 138.2 142.5 141-4 135.3 197.6 202.8 208.0 2371 249.6 302 3°3 269 . 1 138.7 143-0 141-9 135.8 198.3 203.5 208.7 237.9 250.4 303 304 270.0 139-2 143-5 142.4 136.3 198.9 204.2 209.4 238.7 251.3 304 30s 270.9 139-7 144.0 142.9 136.8 199-6 204.9 210. I 239-5 252.1 305 306 271 .8 140 . 2 144-5 143-4 137-3 200.3 20s. S 210.8 240.3 252.9 306 307 272 . 7 140.7 145.0 144.0 137-8 201 .0 206. 2 iJll.S 241 . 1 253-8 307 308 273.6 141 . 2 145-S 144-S 138-3 201.6 206.9 212.2 241-9 254.6 308 309 274-5 141-7 146. 1 1450 138-8 202.3 207.6 212.9 242.7 255-4 309 310 275-4 142 . 2 146 . 6 145-5 139-4 203.0 208.3 2X3-7 243-5 256.3 310 311 276.3 142 . 7 147. 1 146.0 139-9 203.6 209.0 214.4 244-2 257-1 311 312 277 ■ I 143-2 147.6 146.5 140.4 204.3 209.7 215-1 245-0 257-9 312 313 278.0 143-7 148. 1 147.0 140.9 205.0 210.4 215.8 245-8 258.8 313 314 278.9 144-2 148.6 147.6 141.4 205.7 211. I 216.5 246.6 259.6 314 31S 279-8 144-7 149. 1 148. I 141.9 206.3 211. 8 217.2 247-4 260. 4 315 316 280.7 145.2 149.6 148.6 142.4 2070 212. 5 217.9 218.6 248.2 261 . 2 316 317 281.6 145-7 150-1 149-1 1430 207.7 213. I 249-0 262 . I 317 318 282. 5 146. 2 150-7 149-6 143. S 208.4 213.8 219.3 249-8 262 . 9 318 319 283.4 146.7 151. 2 150- 1 144.0 209.0 214. S 220.0 250.6 263.7 319 320 284.2 147-2 151-7 150-7 144.5 209.7 215.2 220.7 251-3 264 . 6 320 321 285.1 147-7 152 .2 151-2 145-0 210.4 21S.9 221.4 252.1 265.4 321 322 286.0 148.2 152-7 151-7 I4S-S 211. 216.6 222.2 252.9 266.2 322 323 286.9 148.7 153-2 1522 146 .0 211. 7 217.3 222.9 253-7 267 . 1 323 324 287.8 149-2 153-7 152-7 146.6 212.4 218.0 223.6 254-5 267.9 324 32s 288.7 149 . 7 154-3 153-2 147-1 213. 1 218.7 224.3 255-3 268.7 32s 326 289.6 150.2 154-8 153-8 147.6 213.7 219.4 225.0 256.1 269. 6 326 327 290.5 150.7 I5S-3 154.3 148.1 214.4 .120. I 225.7 226.4 256.9 270.4 327 328 291 .4 151 -2 155-8 154.8 148.6 215. I 220.7 257-7 271 . 2 328 329 292 . 2 151-7 156-3 155.3 149.1 215.8 221.4 227.1 258.5 272.1 329 330 293.1 152.2 156.8 155.8 T4».7 216.4 222. I 227.8 259-3 272.9 330 331 294 .0 152.7 157-3 156.4 150.2 217. 1 222.8 228.5 260. 273-7 331 332 294.9 153-2 157-9 156.9 150.7 217.8 223. 5 229. 2 260.8 274.6 332 333 295-8 153-7 158.4 157.4 151-2 218.4 224. 2 230.0 261 .6 275-4 333 334 296.7 IS4-2 158.9 157.9 151-7 219. 1 224.9 230.7 262 . 4 276. 2 334 335 297.6 IS4-7 1S9-4 158.4 152-3 219.8 225.6 231.4 263.2 277-0 335 336 298. 5 155-2 159-9 159.0 152.8 220. 5 226.3 2-2.1 232.8 264.0 277-9 336 337 299-3 155-8 160. 5 159.5 153-3 221. I 227. 264.8 278.7 337 338 338 300. 2 156.3 161 .0 160.0 153-8 221.8 227.7 233.5 265.6 279.5 339 301. 1 156.8 161. 5 160. 5 154-3 222. s 228.3 234.2 266 .4 280. 4 339 SUGAR AND SACCHARINE PRODUCTS. 605 MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND MALTOSE— (Co«/j'««ed). [Weights in milligrams.] Invert Sugar and Sucrose. Lactose. Maltose. q 3 d 3 V ■ja .--• d d •0 ■>< 3 0] 3 t/3 H c3 1 . X + + + •0 3 u 2 S, E S 6 d d d d 3 £ a 3 0) a >< > ** bo 03 2^ 0^ 2 a. 3 u Q d 161 .0 N 6 C 6 C u 340 302.0 157-3 162 .0 154-8 223.2 ' 229.0 234-9 267 . 1 281.2 340 341 302.9 IS7-8 162.5 161 .6 IS5-4 223.8 229.7 235-6 267.9 282.0 341 342 303-8 158.3 163. 1 162 . 1 155-9 224.5 230.4 236.3 268.7 282.9 342 343 304-7 158-8 163.6 162 .6 156.4 225.2 231. 1 237.0 269.5 283.7 343 344 305.6 159-3 164. 1 163. I 156.9 225.9 231.8 237-8 270.3 284-5 344 34S 306. S 159.8 164.6 163-7 157.5 226. 5 232. 5 238. 5 271 . 1 285-4 345 346 307-3 160.3 165. 1 164. 2 158.0 227.2 233-2 239.2 271.9 286.2 346 347 308.2 160.8 165-7 164.7 158. 5 227.9 233-9 239.9 272.7 287.0 347 348 309.1 161 . 4 166.2 165 . 2 159.0 228.5 234-6 240.6 273.5 287.9 348 349 310.0 161 .9 166.7 165-7 159-5 229.2 235-3 241-3 274.3 288.7 349 35° 3 1 0' . 9 162 .4 167 . 2 166.3 160. I 229.9 235.9 242.0 275-0 289.5 350 3SI 3II-8 162 .9 167.7 166.8 160 . 6 230.6 236.6 242.7 275.8 290.4 351 352 312.7 163-4 168.3 167-3 161 . 1 231.2 237.3 243.4 276.6 291 .2 352 3S3 313-6 163-9 168.8 167.8 161. 6 231.9 238,0 244.1 277-4 292 .0 353 354 314-4 164-4 169-3 168.4 162 . 2 232.6 238.7 244.8 278.2 292.8 354 355 31S-3 164.9 169-8 168.9 162 . 7 233.3 239.4 245.6 279.0 293-7 355 356 316.2 165.4 170.4 169.4 163.2 233 9 240. I 246.3 279-8 294-5 356 357 317-1 166.0 170.9 170.0 163.7 234.6 240, 8 247.0 280.6 295-3 357 358 318.0 166. 5 171. 4 170.5 164.3 235 3 241.5 247.7 281.4 296.2 358 359 318.9 167 .0 171 .9 171 .0 164.8 236.0 242, 2 248.4 282.2 297-0 359 360 319-8 167-5 172.5 171. 5 165-3 236.7 242.9 249-1 282.9 297-8 360 361 320.7 168.0 173-0 172. 1 165-8 237.3 243.6 249-8 283.7 298 7 361 362 321.6 168.5 173-S 172 .6 166.4 238.0 244-3 250. S 284.5 299-5 362 363 322.4 169 . 174.0 173-1 I '6. 9 238.7 245.0 251.2 285.3 300.3 363 364 323-3 169. 6 174.6 173-7 167.4 239.4 245-7 252.0 286.1 301 . 2 364 365 324-2 170. 1 175-1 174.2 167.9 240.0 246.4 252.7 286.9 302.0 36s 366 32s. I 170.6 175-6 174-7 168.5 240.7 247.0 253-4 287.7 302.8 366 367 326.0 171. 1 176. 1 175-2 169.0 241.4 247.7 254- 1 288.5 303-6 367 j68 326.9 171 . 6 176.7 175.8 169.5 242. I 248.4 254-8 289.3 304-5 368 369 327.8 172. I 177-2 176.3 170.0 242.7 249. I 25S-S 290.0 3OS-3 369 370 328.7 172.7 177-7 176.8 170.6 243-4 249.8 256.2 290.8 306.1 370 371 329s 173-2 178.3 177-4 171. 1 244.1 250.5 256.9 291 .6 307.0 371 372 3'0.4 173-7 178.8 177-9 171 -6 244.8 251.2 257-7 292 .4 307.8 372 373 331-3 174.2 179-3 178.4 172.2 245-4 251-9 258.4 293-2 308.6 373 374 332.2 174-7 179-8 179.0 172.7 246. I 252.6 259. I 294-0 309.5 374 375 333-1 175-3 180.4 179-5 173-2 246.8 253-3 259.8 294-8 310.3 375 ^76 3340 I7S-8 180. 9 180 . 173-7 247.5 254.0 260,5 295.6 311. I 376 377 334-9 176.3 181 .4 180.6 174-3 248. I 254.7 261,2 296.4 312.0 377 378 335-8 176.8 182.0 181. 1 174-8 248.8 255. 4 261 .9 297-2 312.8 378 379 336.7 177-3 182.5 181. 6 175-3 249 -5 256. I 262.6 297.9 313-6 379 380 337-5 177.9 183.0 182. 1 175-9 250.2 236.8 263.4 298.7 314-5 380 381 338-4 178.4 183.6 182.7 176.4 250. 8 257. 5 264. I 299-5 315.3 381 ^82 339-3 178.9 184. I 183.2 176.9 251.5 258, I 264.8 300,3 316. I 382 383 340.2 179.4 184.6 183.8 177-5 252,2 258,8 265.5 301 . I 316.9 383 384 341-I 180.0 185.2 184-3 178.0 252.9 259. 5 266.2 301.9 317-8 384 385 342.0 180.5 185.7 184.8 178.5 253.6 260, 2 266,9 302 .7 318.6 385 386 342.9 181 .0 186.2 185.4 179. I 254.2 260 , 9 267.6 303-5 319-4 386 387 343-8 181. 5 186.8 185.9 179-6 254.9 261,6 268.3 304 2 320.3 387 388 344-6 182.0 187.3 186.4 180. I 255.6 262 ,3 269.0 305-0 321. I 388 389 345-S 182.6 187.8 187-0 180.6 256.3 263.0 269.8 30s -8 321 .9 389 390 346.4 183 -I 188.4 187-5 181. 2 256,9 263.7 270.5 306.6 322.8 390 391 347-3 183,6 188.9 188.0 181,7 257,6 264,4 271.2 307.4 3236 391 392 348.2 184. I 189.4 188.6 182.3 258,3 265, I 271.9 308.2 324-4 392 393 349-1 184-7 190.0 189. 1 182.8 259.0 265.8 272.6 309.0 325-2 393 394 3S0-0 185.2 190.5 189-7 183-3 259.6 266. s 273-3 309-8 326. I 394 6o6 FOOD INSPECTION AND ANALYSIS. MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND lAKLTO^Y.— (Continued). (Weights in milligrams.] 6 Invert Sugar and Sucrose. Lactose. Maltose. 3 3 o 0> "a ^^ »i d d O 3 S^ « u + + + •0 3 u rt c) B rt 6 6 6 6 6 3 o IS 0. 0. u > 1 ?! 1 u 0. 3 o Q d " 6 6 395 350.9 18S-7 191 .0 190.2 183.9 260.3 267.2 274.0 310.6 326.9 395 396 351-8 186.2 191 .6 190.7 184.4 261.0 267.9 274.7 311. 4 327.7 396 397 352.6 186.8 192 . 1 191-3 184-9 261.7 268.6 275.5 312.1 328.6 397 398 353-5 187.3 192.7 191.8 185-5 262.3 269.3 276. 2 312.9 3294 398 399 354-4 187.8 193-2 192.3 186.0 263.0 269.9 276.9 313.7 330.2 399 400 335-3 188.4 193-7 192.9 186.5 263.7 270 . 6 277.6 314.5 33I.I 400 401 356-2 188.9 194-3 193-4 187.1 264.4 271.3 278.3 315.3 331.9 401 402 357-1 189.4 194.8 194.0 187-6 265.0 272.0 279.0 316. 1 332.7 402 403 358.0 189.9 195.4 194-5 188. 1 265.7 272.7 279.7 316.9 333.6 403 404 358.9 190.5 195.9 195-0 188.7 266.4 273.4 280.4 317-7 334.4 404 40s 359-7 191 .0 196.4 195-6 189.2 267. 1 274. I 281. 1 318.5 335-2 40 s 406 360.6 191. 5 197.0 196 . 1 189.8 267.8 274.8 281.9 319-2 336.0 406 407 361.5 192 . 1 197.5 196.7 190.3 268.4 275-5 282.6 320.0 336.9 407 408 362.4 192 .6 198. 1 197.2 190.8 269. 1 276. 2 283.3 320.8 337.7 408 409 3633 193.1 198.6 197.7 191.4 269.8 276.9 284.0 321.6 338.5 409 410 364.2 193.7 199-1 198.3 191-9 270. 5 277.6 284.7 322.4 339.4 410 411 365-1 194.2 199.7 198.8 192-5 271.2 278.3 285.4 323-2 340.2 411 412 366.0 194.7 200 . 2 199.4 193.0 271.8 279.0 286.2 324.0 341.0 412 413 366.9 195.2 200. 8 199.9 193.5 272. 5 279.7 286.9 324-8 341.9 413 414 367.7 195-8 201 .3 200.5 194.1 273.2 280.4 287.6 325-6 342.7 414 41S 368.6 196.3 201.8 201 .0 194.6 273.9 281. I 288.3 326.3 343.5 41s 416 369-5 196.8 202 .4 201 .6 195-2 274.6 281.8 2&9.0 327-1 344.4 416 417 370.4 197.4 202 .9 202 . 1 195-7 275.2 282.5 289.7 327-9 345.2 417 418 371 -3 197.9 203.5 202 . 6 196 . 2 275.9 283. 2 290.4 328.7 346.0 418 419 372.2 198.4 204.0 203.2 196.8 276.6 283.9 291.2 329-5 346.8 419 420 373-1 199.0 204.6 203.7 197-3 277.3 284.6 291.9 330.3 347.7 420 421 374-0 199.5 205 . I 204.3 197.9 277.9 285.3 292 .6 331-1 348.5 421 422 374.8 200. 1 205.7 204.8 198.4 278.6 286.0 293.3 331-9 349.3 422 423 375-7 200.6 206. 2 205.4 198.9 279.3 286.7 294.0 332.7 350.2 423 424 376.6 201 . I 206.7 205.9 199.5 280.0 287.4 294.7 333-4 351.0 424 42s 377-5 201 . 7 207.3 206.5 200.0 280.7 288. I 295.4 334-2 351-8 425 426 378.4 202 . 2 207.8 207 .0 200.6 281.3 288.8 296.2 335-0 352-7 426 427 379-3 202.8 208. 4 207 .6 201 . 1 282.0 289.4 296.9 335-8 353-5 427 428 380,2 203.3 208.9 208.1 201 . 7 282.7 290. I 297.6 336-6 354-3 428 429 381. 1 203.8 209.5 208.7 202 . 2 283.4 290. 8 298.3 337-4 355-1 429 430 382.0 204.4 210.0 209 . 2 202 . 7 284.1 291. 5 299.0 338.2 356.0 430 431 382.8 204.9 210.6 209. 8 203.3 284.7 292. 2 299.7 339-0 356.8 431 432 383.7 205.5 211 . I 210.3 203.8 285.4 292 . 9 300.5 339-7 357-6 432 433 384.6 206.0 211. 7 210.9 204.4 286.1 293.6 301.2 340-5 358.5 433 434 385.5 206.5 212 .2 211.4 204.9 286.8 294-3 301.9 341.3 359-3 434 435 386.4 207 . 1 212.8 212 .0 205.5 287. S 295.0 302.6 342.1 360. 1 435 436 387.3 207 .6 213-3 212.5 206.0 288.1 295-7 303.3 342.9 361.0 436 437 388.2 208.2 213-9 213.1 206.6 288.8 296.4 304.0 343-7 361.8 437 438 389.1 208.7 214-4 213 -6 207 . 1 289. 5 297. I 304.7 344-5 362 .6 438 439 390.0 209.2 215.0 214.2 207.7 290.2 297.8 305. S 345.3 363-4 439 440 390.8 209.8 2 15-5 214.7 208.2 290.9 298. s 306.2 346.1 364-3 440 441 391-7 210.3 216.1 215-3 208.8 291. S 299.2 306.9 346.8 365.1 441 442 392.6 210.9 216.6 215-8 209.3 392.2 299.9 307.6 347-6 365.9 442 443 393.5 21 1 . 4 217.2 216.4 209.9 292.9 300.6 308.3 348.4 366.8 443 444 394.4 212 .0 217.8 216.9 210.4 293.6 301.3 309.0 349-2 567.6 444 445 395-3 212.5 218.3 217-5 211 .0 294.2 302.0 309.7 3SO.O 368.4 44S 446 396.2 213. 1 218.9 218.0 2 1 1 . 5 294.9 302.7 310. s 350.8 369.3 446 447 397-1 213.6 219.4 218.6 212.1 295.6 303.4 311 . 2 351.6 370.1 447 448 397-9 214 I 220.0 219.1 212.6 296.3 304. I 311. 9 312.0 352.4 370.9 448 449 398.8 214.7 220. 5 219.7 213.2 297.0 304.8 353-2 371-7 449 SUGAR AND SACCHARINE PRODUCTS. 607 MIINSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT SUGAR, LACTOSE, AND MKLTOS^— {Continued). [Weights in milligrams.] Invert Sugar and Sucrose. Lactose. Maltose. B 3 V "rt ^-, d d < 3 t-< rt rt 6 ? 6 d d d 3 a 0. 3 a 0, > q 0^ 2^ 0^ 1 13 1 S a 3 u Q d N 6 6 6 CJ 4SO 399-7 215.2 221 . I 220. 2 213-7 297.6 30s -s 313-3 353-9 372.6 450 451 400 . 6 215.8 221 .6 220.8 214.3 298.3 306.2 3140 354-7 373.4 4SI 452 401.5 216.3 222.2 221.4 214.8 299.0 306.9 314-7 355-5 374-2 452 453 402.4 216.9 222.8 221.9 215-4 299.7' 307.6 31S-5 356-3 375-1 453 454 403 -3 217.4 223.3 222 .5 215-9 300.4 308.3 316.2 357- I 375-9 454 45S 404.2 218.0 223.9 223.0 216.5 301 . 1 309-0 316.9 357-9 3-6.7 45S 4S6 40s -I 218. s 224.4 223.6 217.0 301.7 309-7 317.6 358.7 377-6 456 457 405 -9 219. 1 225.0 224. 1 217.6 302.4 310.4 318.3 359-5 3-8.4 457 4S8 406.8 219.6 225-5 224.7 218. I 303.1 311. 1 319.0 360.3 379-2 458 459 407-7 220.2 226. I 225.3 218.7 303.8 311. 8 319.8 361 .0 380.0 459 460 408.6 220. 7 226. 7 225.8 219. 2 304. 5 312.5 320.5 361.8 380.9 460 461 409-5 221.3 227.2 226 . 4 219-8 305-1 313-2 321.2 362 .6 381.7 461 462 410.4 221.8 227.8 226.9 "20.3 305-8 313 9 321.9 363-4 382.5 462 463 4 1 1 - 3 222 .4 228.3 227.5 220 9 300.5 314.6 322 6 364-2 383-4 463 464 4T2 . 2 222 .9 228.9 228.1 221 .4 307 . 2 31S-3 323.4 365-0 384-2 464 46 s 413-0 223-S 229.5 228.6 222 .0 307 9 316.0 324.1 365-8 385-0 465 466 413-9 224.0 230.0 229.2 222.5 308.6 316.7 324.8 366.6 385-9 466 467 414-8 224.6 230.6 229.7 223. I 309.2 317.4 32s. S 367-3 386.7 467 468 4IS-7 225 . 1 231.2 230-3 223.7 309.9 318. I 326.2 368.1 387. S 46S 469 416.6 225.7 231-7 230-9 224.2 310.6 318.8 326.9 368.9 388.3 469 470 417-5 226.2 232.3 231-4 224.8 311. 3 319.5 327.7 369-7 389-2 470 471 418.4 226.8 232.8 232 -0 225.3 312.0 320.2 328.4 370.5 390.0 471 472 419-3 227.4 233-4 232. 5 225.9 312.6 320.9 .'29-1 371-3 390.8 472 473 420. 2 227.9 234-0 233-1 226 . 4 313 3 321.6 329.8 372. I 391 -7 473 474 421 .0 228. 5 234-5 233-7 227 .0 314-0 322.3 330. 5 372.9 392-5 474 475 421.9 229 .0 235-1 234-2 227.6 314-7 323 -0 331-3 373-7 393-3 47S 476 422.8 229.6 235-7 234-8 228.1 315-4 323-7 332.0 374-4 394-2 476 477 423-7 230. I 236 . 2 235-4 228.7 316. I 324-4 332.7 3 7 5-2 395-0 477 478 424.6 230.7 236.8 235-9 229. 2 316.7 325 -I 333.4 376.0 395-8 47? 479 425-5 231 -3 237-4 236.5 229.8 317.4 325.8 334-1 376.8 396.6 470 480 426.4 231.8 237-9 237-1 230.3 318. I 326. 5 334-8 377-6 397-5 /:&a 481 4273 232.4 238-S 237.6 230.9 318.8 327-2 335.6 378.4 398.3 481 482 428. I 232.9 239-1 238.2 231-5 319.5 327.9 336.3 379-2 399- I 482 483 429.0 233-5 239.6 238.8 232 .0 320. I 328.6 337.0 380.0 400 . 483 484 429.9 234-1 240. 2 239-3 232 .6 320.8 329.3 337.7 380.7 400 . 8 484 48s 430.8 234.6 240. 8 239-9 233-2 321. S 330.0 338.4 381.5 401 .6 485 486 431-7 235-2 241.4 240-5 233-7 322.2 30.7 339 . I 382.3 402 .4 486 487 432.6 235-7 241.9 241 .0 234-3 322.9 331.4 339.9 383-1 403-3 487 488 433-5 266.3 242.5 241.6 234-8 323 -6 332- I 340.6 383-9 404- I 488 489 434-4 236.9 243- I 242 . 2 235-4 324.2 332.8 341.3 384-7 404.9 489 490 435-3 237-4 243.6 242.7 236.0 324 9 333-5 342.0 385-5 405.8 490 6o8 FOOD INSPECTION AND ANALYSIS. AUihn's Method for the Determination of Dextrose.* — The solutions used are those described on page 591, except that 125 grams of potassium hydroxide are used in place of 50 grams of sodium hydroxide in preparing the alkaline tartrate solution. Place 30 cc. of Fehling's copper solution, 30 cc. of the alkaline tartrate solution, and 60 cc. of water in a beaker and heat to boiling. Add 25 cc. of the sugar solution, which must be so prepared as not to contain more than 1% dextrose, and boil over the flame for two minutes. Filter immediately without diluting through a Gooch crucible containing a layer of asbestos fiber, prepared as described on page 594, and wash thoroughly with hot water, using reduced pressure. Transfer the asbestos fiber and the adhering cuprous oxide by means of a glass rod to a beaker and rinse the crucible with about 30 cc. of a boiling mixture of dilute sulphuric and nitric acids containing 65 cc. of sulphuric acid (specific gravity 1.84) and 50 cc. of nitric acid (specific gravity 1.42) per liter. Heat and agitate till the solution is complete, then filter into a scrupulously clean, tared platinum dish of loo-cc. capacity, taking care to wash out all the copper solution from the filter into the dish. Deposit the copper electrolytically in the platinum dish and weigh. Deter- mine the dextrose from Allihn's table, p. 609. Or, the metallic copper may be calculated by means of the factor 0.7989 from the cupric oxide obtained as in Defren's method (p. 594) and Allihn's table used. Or, the cuprous oxide as directly obtained by either Allihn's or Defren's method may be washed with alcohol and ether, dried for twenty minutes at 100° C, and weighed, its equivalent in dextrose being ascertained from Allihn's table. Electrolytic Apparatus. — The author has devised the apparatus shown in Fig. 1 10 for the electrolytic deposition of copper in sugar analysis and for other work of like nature. A, Fig. no, is a hard-rubber plate 50 cm. long and 25 cm. wide provided with four insulated metal binding posts, B, each carr}dng at the top a thumb screw by which a coiled platinum wire electrode, C, may be attached. In front of each post is a copper plate about 4 cm. square covered with thin platinum foil, P, which is bent around the edges of the copper plate and so held in place, the copper plate being screwed to the rubber from beneath. On the square platinum- covered plate is set the platinum evaporating-dish which holds the solu- tion from which the copper is to be deposited, the inside of the dish form- ing the cathode, while the electrode C, dipping below the surface of the solution, forms the anode. In front of each platinum-covered plate * Tour, fiir praktische Chemie. 22 (1880), p. 46. SU3AR JND S/iCCH/iRINE PRODUCTS. 609 ALLIHN'S TABLE FOR THE DETERMINATION OF DEXTROSE * MilU- MilH- Mim- Milli- MilU- MilU- MilH- Milli- MilH- MilU- Milli- MilU- grams grams grams grams grams grams grams grams grams grams grams grams of of Cu- of of of Cu- of of of Cu- of of of Cu- of Cop- prous Dex- Cop- prous Dex- Cop- prous Dex- Cop- prous Dex- per. Oxide. trose. per. Oxide. trose. per. Oxide. trose. per. Oxide. trose. n 12.4 6.6 76 85.6 38.8 141 158.7 71.8 206 231.9 105.8 12 13-5 7- I 77 86.7 39.3 142 IS9-9 72.3 207 2330 106.3 13 14. 6 7.6 78 87.8 39-8 143 161 . 72.9 208 234.2 106.8 14 iS-8 81 79 88.9 40.3 144 162.x 73.4 209 235. 3 107.4 IS 16.9 8.6 80 90. 1 40.8 14s 163.2 73-9 210 236.4 107.9 16 18.0 9.0 81 91.2 41.3 146 164.4 74-4 211 237.6 108.4 17 19. I 95 82 923 41.8 147 165-5 74-9 212 238.7 109 . i8 20. 3 10. 83 93-4 42.3 148 166.6 75-5 213 239.8 109.5 19 21.4 10.5 84 94.6 42. 8 149 167-7 76.0 214 240.9 1 10. 20 22.5 II .0 85 95-7 43-4 150 168.9 76. 5 215 242.1 no. 6 21 23.6 II. 5 86 96.8 43-9 iSi 170.0 77-0 216 243.2 III . I 22 24.8 12.0 87 97-9 44-4 152 I 71 . I 77-5 217 244-3 II I . 6 23 25-9 12.5 88 99. I 44.9 153 172.3 78.1 218 245-4 112.1 24 27.0 13-0 89 100. 2 45-4 154 173-4 78.6 219 246. 6 112. 7 25 28.1 J3-S 90 lOI . 3 45-9 155 174-5 79.1 220 247.7 113.2 26 29-3 14.0 91 102 . 4 46.4 156 175-6 79.6 221 248.7 113.7 27 . 30.4 145 92 103.6 46.9 157 176.8 80.1 222 249.9 114.3 28 31-5 iS-o 93 104.7 47-4 158 177-9 80 .'7 223 251 .0 114.8 29 32.7 iS-5 94 105.8 47-9 159 179.0 81 .2 224 252.4 115.3 30 33-8 16.0 95 107 .0 48.4 160 180. 1 81.7 225 253.3 115. 9 31 34-9 16.5 96 108. 1 48.9 161 181. 3 82.2 226 254-4 116. 4 32 36.0 17.0 97 109. 2 49.4 162 182.4 82.7 227 255.6 116.9 a 37-2 175 98 no. 3 49.9 163 183.5 83-3 228 256.7 117. 4 34 38.3 18.0 99 1 1 1 . 5 50.4 164 184.6 83-8 229 257.8 118. 35 39-4 i8.5 100 1 1 2 . 6 50.9 165 185.8 84-3 230 258.9 118.5 36 40. S 18.9 lOI 113-7 Si-4 166 186.9 84.8 231 260. 1 1 19.0 37 41.7 19.4 102 114-8 51-9 167 188.0 85.3 232 261 . 2 1 19 . 6 38 42.8 19.9 103 1 16.0 52.4 1 68 189. I 85.9 233 262.3 120. I 39 43-9 20.4 104 117. I 52.9 169 190.3 86.4 234 263.4 120. 7 40 45.0 20 . 9 105 118. 2 53-5 170 191.4 86.9 235 264 6 121 . 2 41 46.2 21.4 106 1 1 9 . 3 54. 171 192.5 87-4 236 265.7 121 . 7 42 47-3 21.9 107 I 20 . 5 54.5 172 193-6 87.9 237 266.8 122.3 43 48.4 22.4 108 I 21 .6 55. 173 194.8 88.5 238 268.0 122.8 44 49-5 22.9 109 122.7 55-5 174 195-9 89.0 239 269 . 1 123-4 43 SO. 7 23.4 1 10 123.8 56.0 175 197.0 89.5 240 270. 2 123-9 46 51.8 23 -9 1 1 1 125 .0 56. 5 176 198. I 90. 241 271-3 124.4 47 52.9 24.4 1 1 2 126. 1 57-0 177 199-3 90. 5 242 272.5 125.0 48 540 24.9 113 127.2 57-5 178 200.4 91. I 243 273.6 125-5 49 55-2 25-4 114 128.3 58.0 179 201 .5 91 . 6 244 274-7 126.0 50 56.3 25.9 115 129.6 58.6 180 202 . 6 92.1 245 275.8 1 26. 6 SI 57-4 26 . 4 116 130.6 59 -I 181 203.8 92.6 246 277.0 127. 1 S2 58.5 26.9 117 I 3 1 • 7 59-6 182 204.9 93-1 247 278.1 127.6 Si S9-7 274 118 132.8 60 . I 183 206.0 93-7 248 279.2 128. 1 54 60.8 27.9 119 134-0 60.6 184 207 . 1 94-2 249 280.3 128.7 55 61 .9 28.4 I 20 135. 1 61. 1 185 208.3 94.7 250 281.5 I 29. 2 S6 63.0 28.8 121 136.2 61.6 186 209.4 95-2 251 282.6 129.7 S7 64. 2 29.3 122 137-4 62.1 187 210. 5 95-7 252 283.7 130.3 58 65.3 29.8 123 138-5 62.6 188 211. 7 96.3 253 284.8 130.8 S9 66.4 30.3 124 139.6 63.1 189 212.8 96.8 254 286.0 131.4 60 67.6 30.8 125 140.7 63-7 190 213-9 97.3 25s 287.1 131. 9 61 68.7 31-3 126 141. 9 64. 2 191 215.0 97.8 256 288.2 132.4 62 69.8 31-8 I 27 143-0 64.7 192 216.2 98.4 257 289.3 133 -o 63 70.9 32.3 128 144. 1 65.2 193 217.3 98.9 258 290 - 5 133.5 64 72.1 32.8 129 145. 2 65.7 194 218.4 99-4 259 291 . 6 134' 6S 73-2 3i-i 130 146.4 66.2 195 2I9S 100. 260 292.7 134-6 66 74-3 33.8 131 147.5 66.7 196 220. 7 100.5 261 293-8 1 3 5 • I 67 75-4 34-3 132 148.6 67.2 197 221.8 loi .0 262 295-0 135-7 68 76.6 34-8 133 149.7 67.7 198 222.9 101.5 263 296. I 136. 2 69 77-7 35-3 134 150.9 68.2 199 224. 102 . 264 297.2 136.8 70 78.8 35-8 135 152.0 68.8 200 225. 2 102. 6 26s 298.3 137.3 71 79-9 36.3 1 136 153.1 69.3 201 226. 3 103. 1 266 299-5 137-8 72 81. I 36.8 { 137 154-2 69-8 202 227.4 103-7 267 300.6 13S.4 73 82.2 37.3 t 138 155-4 70.3 203 228.5 104. 2 268 301.7 138.9 74 83.3 37.8 139 156-5 - 70.8 204 229.7 104.7 269 302.8 1^9.5 75 84.4 38.3 140 157.6 71.3 205 230.8 105.3 270 304.0 1 40 . * U. S. Dept. of Agric. Bur. of Chem.. Bu'. 65. p i43 6-0 FOOD INSPECTION AND ANALYSIS. ALLIHN'S TABLE FOR THE DETERMINATION OF DEXTROSE — {Continued'). Milli- MilU- Milli- MilH- Milli- Milli- Milli- MilH- MilH- MilU- Milli- Milli- grams grams grams grams grams grams grams grams grams grams grams grams of of Cu- of of of Cu- of of of Cu- of of of Cu- of Cop- prous Dex- Cop- prous Dex- Cop- prous Dex- Cop- prous Dex- per. Oxide. trose. per. Oxide. trose. per. Oxide. trose. per. Oxide. trose. 271 305.1 140.6 321 361.4 168. 1 371 417-7 196-3 421 474-0 225.1 272 306.2 141 . 1 322 362.5 168.6 372 418.8 196.8 422 475.6 225.7 273 307-3 141.7 323 363-7 169. 2 373 420.0 197-4 423 476.2 226.3 274 308. 5 142. 2 324 364-8 169-7 374 421 . 1 198.6 424 477-4 226.9 27s 309.6 142.8 325 365-9 170.3 375 422.2 198.6 42s 478.5 227.5 276 3IO-7 1 43 -3 326 367.0 170.9 376 423-3 199-1 426 479.6 228.0 277 311 -9 143-9 327 368.2 171-4 377 424-5 199.7 427 480.7 228.6 278 3130 144.4 328 369-3 172.0 378 425-6 200.3 428 481 .9 229. 2 279 3141 I45-0 329 370.4 172.5 379 426.7 200.8 429 4S30 229.8 280 315-2 145-5 330 371-S 173-1 380 427-8 201 . 4 430 484.1 230.4 281 316.4 146. 1 331 372-7 173-7 381 429.0 202.0 431 485-3 231.0 282 317-5 146.6 332 373-8 174.2 382 430-1 202. 5 432 486.4 231.6 283 318.6 147-2 333 374-9 174-8 383 431-2 203. 1 433 487-5 232.2 284 319-7 147-7 334 376-0 175-3 384 432.3 203.7 434 488.6 232.8 28s 320.9 148-3 335 377-2 175-9 385 433-5 204.3 435 489-7 233.4 286 322.0 148.8 336 378.3 176. 5 386 434-6 204. 8 436 490.9 233-9 287 323-1 149.4 337 379-4 177-0 387 435-7 205.4 437 492.0 234. S 288 324-2 149.9 338 380.5 177.6 388 436-8 206.0 438 493.1 235-1 289 3254 150.5 339 381-7 178. I 389 438.0 206. 5 439 494-3 235-7 390 326. S 151 .0 340 382.8 178.7 390 439-1 207 . 1 440 495-4 236.3 291 327-4 151 -6 341 3S3-9 179-3 391 440.2 207.7 441 496.5 236.9 292 328.7 152. 1 342 385-0 179-8 392 441-3 208.3 442 497-6 237.5 293 329-9 152.7 343 386.2 180.4 393 442.4 208.8 443 498.8 238.1 294 331-0 153-2 344 387.3 180.9 394 443-6 209.4 444 499-9 238.7 39s 332.1 IS3-8 345 388.4 181. 5 395 444-7 210.0 445 501.0 239.3 296 333-3 154-3 346 389-6 182. 1 396 445-9 210. 6 446 502. I 239.8 297 334-4 154-9 347 390.7 182.6 397 447-0 211 . 2 447 S03-2 240.4 298 335-5 155-4 348 391-8 183-2 398 448.1 211 .7 448 504-4 241 .0 299 336.6 156.0 349 392-9 183-7 399 449-2 212.3 449 505.5 241 .6 JOO 337-8 156. J 350 394-0 184-3 400 450-3 2 1 2 . <)' 450 506.6 242 . 2 301 338-9 157-T 351 395-2 184.9 401 451-5 213-5 451 507.8 242.8 302 340.0 157-6 352 396-3 185-4 402 452-6 214. I 452 508.9 243.4 303 341 -I 158-2 353 397-4 186.0 403 453-7 214. 6 453 Sio.o 244.0 304 342-3 158-7 354 398.6 186.6 404 454-8 215-2 . 454 Sii.i 244.6 i^S 343-4 159-3 355 399-7 187-2 405 456.0 215-8 455 512.3 245-2 306 344-5 159-8 356 400. 8 187.7 406 457-1 216.4 456 513-4 245-7 .•?o7 345-6 160.4 357 401 .9 188.3 407 458-2 217.0 457 S14-5 246.3 3^8 346-8 160.9 358 403- I 188.9 408 459-4 217.5 458 515-6 246.9 309 347-9 161 .5 359 404.2 189.4 409 460 . 5 218. 1 459 516.8 247-5 cjio 349 -o 162.0 360 405-3 190.0 410 461 . 6 218.7 460 517-9 248.1 311 350. I 162.6 361 406.4 190.6 411 462.7 219-3 461 519.0 248.7 312 351-3 163. I 362 407.6 191 . 1 412 463.8 219.9 462 520. I 249-3 313 352-4 163-7 363 408.7 191-7 413 465-0 220.4 463 521.3 249.9 314 353-5 164. 2 364 409. 8 192.3 414 466. 1 221.0 31S 354-6 164.8 365 410.9 192.9 415 467.2 221 . 6 316 355. 8 165-3 366 41 2 . I 193-4 416 468.4 222. 2 317 356.9 165.9 367 413-2 194-0 417 469-5 222.8 318 358.0 166 . 4 368 414-3 194.6 418 470.6 223.3 319 359-1 167 .0 369 415-4 195-1 419 471.8 223.9 320 360.3 167.5 370 416.6 195-7 420 472.9 224-5 is a switch, S, and at either end of the hard-rubber plate is a binding post, R, for connection with the electric current. The wiring, which is on the under side of the rubber plate, is best illustrated by the diagram in Fig. no. Four determinations may be carried on simultaneously in four plat- inum dishes, if desired, the wiring and the switches being so arranged that beginning at one end of the plate either the first dish or the first SUG/IR AND SACCHARINE PRODUCTS. Oil \ a: ^ G^ O / \ 1 O /^ (b s G) 3 K 3 Fig. iio. — Four Pan Electrolytic Apparatus, shown (above) with Glass-covered Top Partially Removed, and (below) in Diagram. 6i2 FOCD INSPECTION AND ANALYSIS. two or the first three may be thrown in or out of circuit at will without interrupting the current through the remaining dishes. A cover with- wooden sides and glass top fits closely over the whole apparatus as a. protection from dust, but may be easily lifted off to manipulate the dishes when desired. The sides of the cover are perforated to permit, the escape of the gas formed during the electrolysis. The ordinary street current is used when available, and the strength of the current may be varied within wide limits by means of a number of 1 6 or 32 candle-power lamps, A', coupled in multiple, and a rheostat, L, consisting of a vertical glass tube sealed at the bottom, containing a. column of dilute acid, the resistance being changed by varying the length of the acid column contained between the two platinum terminals immersed therein, one of which 'is movable. A gravity battery of four cells may be employed if the laboratory is not equipped with electric lights. In using this apparatus for determining copper, as in sugar work, the plating process should go on till all the copper is deposited, requiring, several hours or over night with a current strength of about 0.25 ampere. Before stopping the process, the absence of copper in the solution should be proved by removing a few drops with a pipette, adding first ammonia, then acetic acid, and testing with ferrocyanide of potassium. If no brown coloration is produced, all the copper has been plated out. Throw the dish out of circuit by means of the switch, pour out the acid solution quickly before it has a chance to dissolve any of the copper, wash the dish first with water and then with alcohol, dry, and weigh. The copper may be "removed from the platinum dish by strong nitric acid. Determination of Sucrose by Fehling's Solution.* — If a polariscope is not available, cane sugar can be determined as follows : First determine the percentage of invert sugar present in the sample by one of the Fehling methods already described. Then dissolve i gram of the sugar in about 100 cc. of water in a 500-cc. graduated flask, add 3 cc. of concentrated hydrochloric acid and invert by heating in water to 68° and cooling in the regular manner. Neutralize with sodium hydroxide or sodium carbonate, and make up to the mark with water. Determine the per cent of total reducing sugar as invert sugar either by the volumetric or gravimetric Fehling process. Subtract the invert sugar found present in the sugar by direct determination from the total found present after inversion, and * Tucker, Manual of Sugar Analysis, p. 182. SUGAR AND SACCHARINE PRODUCTS. 61^ the remainder is the invert sugar due to cane sugar. This figure multi- plied by 0.95 gives the percentage of cane sugar. For the determination of sucrose by the gravimetric Fehling process on the inverted sample, multiply the cupric oxide (CuO) by the factor 0.4307, or the copper (Cu) by the factor 0.5394, ANALYSIS OF MOLASSES AND SYRUPS, First insure a perfectly homogeneous sample by stirring with a rod to evenly distribute any separated sugar. Determination of Total Solids, — (i) Asbestos Method. — Weigh 20 grams into a loo-cc. graduated flask, dissolve in water, and make up to the mark. Insure a uniform solution by shaking. Measure 10 cc. of this solution into a tared platinum dish containing about 5 grams of freshly ignited, finely divided asbestos fiber, and dry to constant weight at 70° in vacuo, or in a McGill oven (see p. s86). (2) Sand Method.'*' — Place about 15 grams of ignited quartz sand and a stirring rod in a flat-bottom metal dish and weigh. Add 2 to 4 grams of the material and sufficient moisture to permit thorough mixing. Dry on a water bath with stirring and finally in a water oven until the loss in weight in one hour is not more than 3 mg. At least 8 hours' heating is usually required. (3) By Calculation from Refractive Index. — Determine the refractive index by means of the Abbe refractometer (p, 108), and calculate the total solids, using Geerhgs's tables (p. 615). This method is more accurate and convenient than the specific gravity method and employs a smaller quantity of material. The investigations of Stollef and of Tolman and SmithJ have shown that sucrose, maltose, dextrose, levulose and lactose all have practically the same refractive index. Dextrin has a somewhat higher refractive index, nevertheless the solids of commercial glucose do not give a reading appreciably higher than the sugars named. A. H. Bryan, § has compared this method with the method of drying at 70° in vacuo, with the following results: * U. S. Dept. Agric., Bur. of Chem., Bui. 107 (rev.), p. 65. t Zeits. deutsch. Zucker-Ind., 1901, pp. 335, 469. X Jour. Am. Chem. Soc, 28, 1906, p. 1476. § Ibid., 30, 1908, p. 1443. ^14 FOOD INSPECTION AND /IN A LYSIS. \ Material. Number of Difference compared Samples. with the Gravimetric Method. Maple syrup 13 -1.3410+0.72 Cane table syrup 10 -0.79" +0.62 Cane molasses 17 — 1.53 " +0.59 Beet molasses 15 —1-83 " —0.07 Honey 24 -2.52" +0.91 Glucose 2 -0.27 " +0.27 (4) By Calculation from Specific Gravity. — Weigh 25 grams of the sample into a loo-cc. graduated flask, dissolve in water, and make up 20° to the mark. Determine the specific gravity, at — ^ C, of the diluted 4 solution by means of a pycnometer or accurate hydrometer. Ascertain from the table on pp. 617 and 618 the percentage by weight of solids (sugar) corresponding to the specific gravity of the diluted solution, and calculate the total solids in the original sample by the formula Solids in original sample = 4Z)5', D being the specific gravity of the diluted solution and 5 the per cent of solids in the diluted solution. The solids may also be obtained directly by means of the saccha- rometer, also known as the Brix spindle. This instrument is a hydrometer graduated so as to show the per cent of sugar when the temperature of the Hquid is 20° C. If the specific gravity or saccharometer reading is taken at any other temperature than 20° C. the necessary correction may be found in. the table on page 619. Determination of Ash. — Weigh from 5 to 10 grams of the sample into a tared platinum dish, evaporate to dryness on the water-bath, and proceed as directed for ash of sugar (p. 586). Polarization and Determination of Sucrose. — Molasses and golden syrup require the application of clarifying reagents before a sufficiently clear solution can be obtained for reading on the polariscope. Even then it is not possible nor is it necessary to get a water- white solution, so that in this class of products greater accuracy can usually be attained by polarizing in a loo-mm. tube (half the standard length) and multiplying the reading by 2. The clarifier best adapted as a rule for molasses and golden syrup is lead subacetate either in solution (p. 586) or, as first proposed by Home,* as the anhydrous salt. * Jour. Am. Chem. Soc, c6, 1904, p. 186. SUGAR AND SACCHARINE PRODUCTS. 6iS GEERLIGS'S TABLE FOR DRY SUBSTANCE IN SUGAR-HOUSE PRODUCTS BY THE ABBE REFRACTOMETER, AT 28° C* Per Per Refrac- Cent Decimals to be Added for Re frac- Cent Decimals to be Added for tive Dry Fractional Readings. t _ ' ive Dry Fractional Readings. t Index. Sub- stance. 1 In dex. Sub- stance. 1-3335 I 0.0001=0.05 0.0010 = 0.75 I. 4083 45 0.0004 = 0.2 0.0015 = 0.75 1-3349 2 0.0002 = 0.1 0.0011 = 0.8 I. 4104 46 0.0005 = 0.25 0.0016 = 0.8 1-3364 3 . 0003 = 0.2 0.0012 = 0.8 I. 4124 47 0.0006 = 0.3 0.0017 = 0.85 1-3379 4 0.0004 = 0.25 0.0013 = 0.85 I. 4145 48 0.0007 = 0.35 0.0018 = 0.9 1-3394 5 0.0005 = 0.3 0.0014 = 0.9 I. 4166 49 0.0008 = 0.4 0.0019 = 0.95 1-3409 6 0.0006 = 0.4 0.0015=1.0 I. 4186 50 0.0009=0.45 0.0020=1.0 1-3424 7 0.0007 = 0.5 4207 51 0.0010=0.5 0.0021 = 1.0 1-3439 8 0.0008 = 0.6 4228 52 0.0011=0.55 1-3454 9 0.0009 = 0.7 4219 53 1.3469 10 4270 54 1.3484 II 0.0001 = 0.05 4292 55 0.0001 = 0.05 0.0013 = 0.55 1-3500 12 0.0002 = 0.1 4314 56 0.0002 = 0.1 0.0014 = 0.6 1-3516 13- 0.0003 = 0.2 4337 57 . 0003 = 0.1 0.0015 = 0.65 1-3530 14 0.0004 = 0.25 4359 58 0.0004=0.15 0.0016 = 0.7 1-3546 15 0.0005 = 0.3 4382 59 0.0005 = 0.2 0.0017 = 0.75 1-3562 16 . 0006 = 0.4 4405 60 0.0006 = 0.25 0.0018 = 0.8 1-3578 17 0.0007 = 0.45 4428 61 . 0007 = 0.3 0.0019 = 0.85 1-3594 18 . 0008 = 0.5 4451 62 0.0008 = 0.35 0.0020 = 0.9 1.3611 19 0.0009=0.6 4474 63 0.0009 = 0.4 0.0021=0.9 1.3627 20 0.0010=0.65 4497 64 0.0010 = 0.45 0.0022 = 0.95 1-3644 21 0.0011 = 0.7 4520 65 0.0011 = 0.5 0.0023= i-o I. 3661 22 0.0012 = 0.75 4543 66 0.0012 = 0.5 0.0024=1.0 1.3678 23 0.0013 = 0.8 4567 67 1-3695 24 0014 = 0.85 4591 68 1. 3712 25 0.0015 = 0.9 4615 69 1-3729 26 0.0016=0.95 4639 4663 4687 70 71 72 1-3746 27 0.0001=0.05 0.0012 = 0.6 1-3764 28 0.0002 = 0.1 ^0 T 1 ^= n c — ^ . \J\J L \ —' \J a\JS 1.3782 29 . 0003 = 0.15 0.0014 = 0.7 I 4711 73 0.0001 = 0.0 0.0015=0.55 1.3800 30 0.0004 = 0.2 0.0015 = 0.75 I -4736 74 0.0002 = 0.05 0.0016 = 0.6 I. 3818 31 0.0005 = 0.25 0.0016 = 0.8 I .4761 75 0.0003 = 0.1 0.0017 = 0.65 1-3836 32 0.0006 = 0.3 0.0017 = 0.85 I -4786 76 0.0004 = 0.15 0.0018 = 0.65 1-3854 33 0.0007 = 0.35 0.0018 = 0.9 1 .4811 77 0.0005 = 0.2 0.0019=0.7 1.3872 34 0.0008 = 0.45 0.0019=0.95 I -4836 78 0.0006 = 0.2 0.0020=0.75 1.3890 35 0.0009 = 0.4 0.0020=1.0 I .4862 79 0.0007 = 0.25 0.0021 = 0.8 1.3909 36 0.0010 = 0.5 0.0021 = 1.0 I .4888 80 0.0008 = 0.3 0.0022 = 0.8 1-3928 37 0.0011 = 0.55 .4914 8i 0.0009 = 0.35 0.0023 = 0.85 1-3947 38 .4940 82 0.0010 = 0.35 0.0024 = 0.9 1-3966 39 .4966 83 0.0011=0.4 0.0025 = 0.9 1-3984 40 -4992 84 0.0012 = 0.45 0.0026 = 0.95 1.4003 41 .5019 85 0.0013 = 0.5 0.0027= i-o -5046 86 87 0014 = 0.5 0.0028=1.0 -5073 1.4023 42 0.0001 = 0.05 0.0012 = 0.6 I .5100 88 1-4043 43 0.0002 = 0.1 0.0013 = 0.65 I •5127 89 1.4063 44 . 0003 = 0.15 0.0014 = 0.7 I •5155 90 * Intern. Sugar Jour., 10, pp. 69-70. t Find in the table the refractive index which is next lower than the reading actually made and note the corresponding whole number for the per cent of dry substance. Subtract the refractive index obtained from the table from the observed reading; the decimal corresponding to this difference, as given in the column so marked, is added to the whole per cent of dry substance as first obtained. 6i5 FOOD INSPECTION AND ANALYSIS. TEMPZ:^ATURE CORRECTIONS FOR USE WITH GEERLIGS'S TABLE. Tempera- Dr> Substance. ture of the Prisms in 1 5 10 15 1 20 25 1 30 1 40 1 50 1 60 1 70 80 QO "C. Subtract — 20 0-53 0.54 0-55 0.56 0.57 0.58 0.60 0.62 0.64 62 61 0.60 0.58 21 .46 -47 .4« -49 -50 -51 •52 -54 -56 54 53 -52 •50 22 .40 -41 .42 .42 -43 -44 -45 •47 -48 47 46 -45 • 44 23 ■?,^ -33 -34 -35 ■i^ •37 -3« -39 .40 39 38 •3H •3» 24 .26 .26 .27 .28 .28 .29 •30 •31 •32 31 31 -30 -30 ^5 .20 .20 .21 .21 .22 .22 •23 •23 .24 23 23 -23 .22 26 .12 .12 -13 -14 -14 -15 -15 .16 .16 16 15 -15 -14 27 .07 .07 .07 .07 -07 .07 .08 .08 .08 08 08 .08 .07 Add— 29 0.07 0.07 0.07 0.07 0.07 0.07 0.08 0.08 0.08 .08 .08 0.08 0.07 30 .12 .12 -13 -14 .14 .14 -15 -15 .16 .16 .16 ■15 ■14 31 .20 .20 .21 .21 .22 .22 •23 -23 ■24 ■23 -23 -23 .22 32 .26 .26 .27 .28 .28 .29 -30 •31 -32 -31 -31 -30 -30 33 -33 -33 •34 -35 -3(5 •37 •38 -39 .40 •39 -38 ■38 -3« 34 .40 .41 .42 .42 -43 -44 -45 -47 .48 -47 .4(3 -45 -44 35 .46 -47 .48 .49 -50 -51 -52 -54 -56 -54 ■5^ .=;2 -50 The Process. — The normal weight, 26 grams, of the molasses or syrup is dissolved in water in a loo-cc. flask, and in the case of molasses and "golden," or "drip" syrup, sufficient subacetate of lead solution is added to precipitate the coloring matter. From 5 to 10 cc. of the clarifier usually suffice. The flask is then filled to the mark with water and the contents shaken thoroughly and filtered. If on account of air bubbles it is difficult to make up to the mark, the bubbles may usually be dis- pelled by a drop of ether. With maple syrup no clarifier is, as a rule, necessary, though sometimes alumina cream is helpful. With a very dark-colored molasses 20 to 30 cc. of lead subacetate are required for clarification and in extreme cases (though rarely with the grades of molasses used as food) it is necessary, after the ordinary filtration, to pass through from 5 to 6 grams of powdered, dried bone charcoal.* An excess of subacetate of lead should be avoided on account of the possibility of the filtrate becoming turbid through the formation of lead carbonate by exposure to the air. A drop of acetic acid will nearly always clear the solution, if the turbidity is due to carbonate. If cloudiness in the filtrate persists, weigh out a fresh portion of the sample, dilute, and add first the lead subacetate solution, and afterwards enough of a strong solution of sodium sulphate or common salt to precipitate the excess of lead; then fill to the mark and filter. Polarize, and conduct the inver- sion as directed on p. 588, using, however, a 100- mm. tube, and multi- * The treatment with bone char should be used only as a list resort, as, on account of slight absorption of sugar, observed readings are from 0.4°, to to 0.5° too low. SUG/tR AND SACCHARINE PRODUCTS. 617 DENSITY OF SOLUTIONS OF CANE SUGAR AT -^ C. 4 £!5 a, Tenths of Per Cent. I 2 3 4 5 6 7 8 9 .9982 0.9986 . 9990 0-9994 0. 9998 I .0002 I . 0006 I .0010 I .0013 I .0017 I I .0021 I .0025 I .0029 I 0033 1-0037 I .0041 I . 0045 I .0048 r .0052 I .0056 2 I .0060 I .0064 I .0068 I .0072 I . 0076 I .0080 I .0084 I -0088 I .0091 I .0095 3 I .0099 I .0103 I .0107 I .0111 I -0115 I .0119 I .0123 I .0127 I .0131 I-OI35 4 I. 0139 I .0143 I .0147 I -0151 I-OI55 I .0159 I .0163 I .0167 I .01 71 r-0175 5 I. 0179 I .0183 I .0187 r .0191 I .0195 I .0199 I -0203 I .0207 I .02 1 1 I -0215 6 I .02 19 I .0223 I .0227 I .0231 I -0235 I .0239 1.0243 1.0247 I -0251 I -0255 7 I .0259 i .0263 I .0267 I .0271 I .0276 I .0279 I -0283 I .0287 I .0291 1.0295 8 I .0299 I -0303 I .0308 I .0312 I .0316 I .0320 1-0324 1-0328 I -0332 r-0336 9 I .0340 I .0344 I -0349 I -03 S3 1-0357 I .0361 I -0365 I .0369 I -0373 1-0377 10 I .0381 1.0386 I .0390 I -0394 1.0398 I .0402 I .0406 I .0410 I .0415 1. 04 1 9 I I I .0423 I .0427 I .0431 I -043s I .0440 I .0444 I .0448 I .0452 I .0456 I .0460 12 I .0465 I .0469 I -0473 I .0477 I .0481 I .0486 I . 0490 I .0494 I -0498 I .0502 13 I .0507 1.0511 I -051S I .0519 I .0524 I .0528 I -0532 1.0536 I -0540 I -0545 14 I .0549 I -0553 1-0558 I .0562 I .0566 I .0570 I -0575 1.0579 1-0583 I .0587 IS I .0592 I -.0596 I .0600 I .0605 I .0609 I .0613 I .0617 I .0622 I .0626 I .0630 16 I -0635 I .0639 I -0643 I .0648 I .0652 I .0656 I .0661 I .0665 I .0669 I -0674 17 1.0678 1.0682 I .0687 I .0691 I .0695 I .0700 I .0704 I .0708 1-0713 I -0717 18 I .0721 I .0726 I .0730 I -0735 1-0739 1.0743 I .0748 I .0752 1-0757 I .0761 19 1.0765 I .0770 I .0774 I -0779 1.0783 I .0787 I .0792 I .0796 I .0801 I .0805 20 I .0810 r .0814 I .0818 I .0823 I .0827 1.0832 I .o8s6 I .0841 I .0845 I .0850 2 I I .0854 1.0859 I -0863 I .0868 I .0872 I .0877 I .0881 I .0885 I .0890 I .0894 22 I .0899 I .0904 t .0908 I .0913 1. 0917 I .0922 I .0926 I .0931 I 0935 I .0940 23 I .0944 I .0949 1-0953 I -0958 I .0962 I .0967 I . 097 I I .0976 I .0981 1.0985 24 I .0990 1.0994 I .0999 I . 1003 I . 1008 I . 1013 I . lOI 7 I . ro22 I . 1026 1.1031 25 I . 1036 I . 1040 I .1045 I . 1049 I .1054 I . 1059 I .1063 I .1068 I . 1072 I. 1077 26 I . 1082 I .1086 I . 1091 I . 1096 I . 1 100 I . 1105 I . 1 1 10 I . 1 1 14 I . 1 1 19 I . 1 124 27 r .1128 I .1133 I .1138 I . 1142 I .1147 I . 1 1 52 I . 1156 I . 1 161 I . 1 166 I . 1 1 70 28 I . 1175 I . 1 1 80 I . 1185 I . 1 189 I .1194 1. 1 199 I . 1203 I . 1208 I .1213 1.1218 29 I . 1222 I . I 227 1. 1232 I -1237 I . 1241 I . 1246 I . 1251 I . 1256 I .1260 I . 1265 30 I . 1270 I -1275 I . I 279 I .1284 I . 1289 I .1294 1. 1299 I -1303 I . 1308 I -1313 31 I . 1318 I -1323 I-1327 I ■ 1332 I - 1337 I - 1342 I. 1347 I -1351 1-1356 I . 1361 32 I. 1366 I -1371 I -1376 I . 1380 I. 1385 I . 1390 1-1395 I . 1400 I . 1405 I . 1410 33 1.1415 I . 1419 I. 1424 I .1429 I. 1434 I • 1439 I -1444 I . 1449 I ■ 1454 1. 1459 34 I. 1463 I .1468 I -1473 I .1478 I. I 483 I -1488 I -1493 1. 1 498 1-1503 I .1508 35 1-1513 I . 1518 I -1523 I . 1528 I -1533 1-1538 I-1542 I -1547 1-1552 1-1557 36 I . 1562 1.1567 1-1572 1-1577 I. 1582 I. 1587 I .1592 I -1597 I . 1602 I .1607 37 I . 1612 I . 1617 I . 1622 I . 1627 I .1632 I . i6?7 I .1643 I .1648 I-1653 I. 1658 38 I. 1663 I. 1668 1-1673 I .1678 I. 1683 I. 1688 I. 1693 I .1698 1. 1 703 I . 1708 39 1.1713 1.1718 I. 1724 I .1729 I-1734 I -1739 I. 1744 I. 1749 I -1754 I-I7S9 40 I .1764 I .1770 I -1775 I . 1780 I-1785 I .1790 I. 1795 I . 1800 I .1806 1.1811 41 1.1816 I . 1821 I . 1826 I . 1 83 I I. 1837 I . 1842 I -1847 I. 1852 I. 1857 I. 1863 42 I. 1868 1-1873 I. 1878 I .1883 1. 1 889 I . 1894 I . 1899 I . 1904 I . 1909 1-191S 43 I . 1920 I . 1925 I. 1930 I .1936 I .1941 I . 1947 1-1951 I-I957 I . 1962 I .1967 44 I. 1972 I .1978 1-1983 I .1988 I .1994 I . 1999 I . 2004 I .2009 I . 2015 I . 2020 45 I .2025 I .2031 I .2036 I . 2041 I .2047 r . 2052 I -2057 I .2063 I .2068 1.2073 46 I .2079 I . 2084 I . 2089 I .2095 I . 2100 I .2105 I . 21 1 1 I . 2116 I . 2 I 22 I . 2127 47 t . 21 ^2 I. 2138 r .2143 I .2149 I .2154 I .2159 I .2165 I . 21 70 I . 21 76 I .2181 48 I .2186 I .2192 I .2197 I .2203 I . 2208 I . 2214 I . 2219 I .2224 I -2230 1-2235 49 I . 2241 I . 2246 1.2252 I .2257 I .2263 I .2268 I .2274 1.2279 1.2285 I .2290 50 I . 2296 I .2301 I .2307 1.2312 I. 2318 I -2323 I .2329 1-2334 I .2340 1-2345 * According to Dr. F. Plato (Kaiserlichen Normal-Eichungs-Kommission, Wiss. Abh., 2, 1900, p. I 53). This table is given by the U. S. Bureau of Standards (Circular 19, pp. 12 and 13) as the basis for standardizing hydrometers, indicating per cent of sugar at 20°, known as saccharometers or Brix spindles. The table is also useful in calculating the per cent of sugar from the specific gravity as ■determined by the pycnometer. Temperature corrections are given on page 619. 6i8 FOOD INSPECTION AND ANALYSIS. DENSITY OF SOLUTIONS OF CANE SUGAR AT C. — Continued Tenths of Per Cent. I 2 3 4 5 6 7 8 9 50 I . 2296 I . 2301 I -2307 1-2312 I. 2318 1 .2323 I .2329 I -2334 I .2340 1.2345 _Si 1-2351 I .2356 I .2362 1 .2367 1-2373 1.2379 I .2384 I .2390 1.2395 I .2401 52 I . 2406 I . 2412 I . 2418 I .2423 I . 2429 I .2434 I .2440 I .2446 I .2451 1.2457 .S3 I . 2462 1.2468 1-2474 1.2479 1.2485 I . 2490 I . 2496 I . 2502 1.2507 1.2513 54 1-2519 1.2524 I -2530 I -2536 I .2541 1.2547 1-2553 1-2558 1 .2564 I .2570 5 5 I -2575 I. 2581 1-2587 I .2592 1-2598 I .2604 I . 2610 I . 2615 I . 262 1 I . 2627 56 I -2632 1.2638 I . 2644 I . 2650 1.265s I . 2661 I . 2667 I .2673 I .2678 I .2684 57 I . 2690 I .2696 I . 2701 I . 2707 1.2713 1.2719 I .2725 I .2730 I .2736 I .2742 58 1.2748 I -2754 I -2759 I .2765 I. 2771 1.2777 1.2783 I .2788 I .2794 I . 2800 59 I .2806 I .2812 1.2818 1.2823 I . 2829 1.2835 I .2841 I .2847 1.2853 1.2859 60 1.286s 1 .2870 I .2876 1.2882 1.2888 1 .2894 I . 2900 I . 2906 I . 2912 I .2918 Oi I .2924 1.2929 I -2935 I .2941 1.2947 1.2953 I -2959 1.2965 I. 2971 1.2977 62 1.2983 I . 2989 1-2995 I .3001 1.3007 1.3013 1 -3019 I .3025 1.3031 1.3037 63 I -3043 I -3049 I -3055 I .3061 I .3067 1 .3073 I -3079 1.3085 I. 3091 I 3097 64 I .3103 I. 3109 I -3115 I .3121 I-3127 13133 I-3139 1.3145 I .3151 I .3157 65 I -3163 I .3169 1-3175 1-3182 I. 3188 I .3194 1.3200 I .3206 1 .3212 1.3218 66 1 -3224 1-3230 I -3236 I -3243 1-3249 1.325s I .3261 1.3267 1.3273 I -3279 67 1.3286 1.3292 I -3298 I -3304 1-3310 I .3316 I -3322 1.3329 1. 3335 1-3341 68 I -3347 I -3353 I -3360 I -3366 1-3372 1.3378 1-3384 I. 3391 1.3397 1.3403 69 13409 I .3416 I -3422 I -3428 I -3434 I .3440 1.3447 1.3453 1.3459 1.3465- 70 I -3472 I -3478 1 -3484 I -3491 1-3497 1.3503 I .3509 1. 3516 1.3522 1.3528 71 I -3535 I-3S4I I -3547 I -3553 1.3560 1.3566 1.3572 1.3579 1.3585 1.3591 72 1-3598 1 -3604 I .3610 I -3617 1.3623 1.3630 I .3636 I .3642 1 .3649 1-3655 73 I -3661 1.3668 I -3674 I. 3681 1-3687 1 3693 I .3700 I .3706 1.3713 I -3719 74 I -3725 1-3732 1-3738 1-3745 1-3751 1.3757 I .3764 1.3770 1-3777 1-3783 75 1-3790 1-3796 1 -3803 I -3809 I. 3816 1.3822 I -3829 1.3835 I. 3841 1-3848 76 I -3854 I. 3861 I-3S67 I -3874 I .3880 1.3887 I -3893 I .3900 1.3907 1 -3913 77 I -3920 1.3926 I -3933 I -3939 1 -3946 1 -3952 1-3959 1.3965 1.3972 1-3978 78 1-3985 1-3992 I -3998 I . 4005 I . 4011 I .4018 r.4025 1.4031 1.4038 1 - 4044 79 I .4051 I .4058 I -4064 I - 4071 1 -4077 I .4084 I .4091 1.4097 1.4104 I - 41 1 1 80 I .4117 I .4124 I .4130 I-4137 1 .4144 1.4150 I .4157 I . 4164 I. 4170 1-4177 81 I .4184 I .4190 I .4197 I . 4204 I .4210 1 .4217 I -4224 1.4231 1.4237 1.4244 82 1 .4251 I -4257 1 . 4264 1 .4271 1.4278 I . 4284 I .4291 I .4298 1.4305 I - 43 1 1 83 1-4318 I -4325 1-4332 1.4338 I-434S 1.4352 1.4359 1.4365 1.4372 I -4379 84 1.4386 I ■4?93 I -4399 I . 4406 I -4413 I . 4420 1 .4427 1.4433 1.4440 1 -4447 8s I -4454 I . 4461 I .4468 I .4474 I .4481 I .4488 1-4495 1.4502 1 .4509 I-451S 86 1.4522 1-4529 I -4536 I -4543 1.4550 I -4557 1.4564 1.4570 I .4577 1-4584 87 I-459I 1.4598 I - 4605 I .4612 I . 4619 I . 4626 1.4633 I .4640 I . 4646 1-4653 88 I . 4660 I .4667 I -4674 I .4681 1.4688 1.4695 1.4702 I .4709 I. 4716 1 -4723 89 I -4730 I -473 7 I .4744 I -4751 1.4758 1.4765 1.4772 1.4779 I .4786 1-4793 90 I .4800 I .4807 I .4814 1. 482 I 1.4828 I - 483 5 I . 4842 I .4849 1.4856 1-4863 91 I .4870 1.4877 1.4884 I .4891 I . 4898 I .4905 1 .4912 I .4919 I .4926 1-4934 92 I .4941 1.4948 1-495 5 I . 4062 1.4969 I .4976 1 -4983 1.4990 I .4997 1 -5004 93 I. 5012 I. SO 1 9 I .5026 I 5033 I . 5040 1.5047 1-5054 I . 5061 I .5069 1.5076 94 I 5083 I. 5090 I -5097 1 -5104 I . 51 I 2 I .5119 I -5126 1.5133 I ,5140 I-5I47 95 1 -5155 1 - 5162 1.5169 I-5176 1.5183 I-5191 1-S198 1 .5205 I . 5212 1 -5219 96 I .5227 1-5234 1.5241 1.5248 1.5255 1 -5263 I .5270 1.5277 I .5284 I -5292 97 I -5299 I .5306 1-5313 1-5321 1.5328 1 -5335 1-5342 I.53SO 5.5357 I - 5364 98 I-S372 1-5379 1-5386 1-5393 1.5401 1 - 5408 1-5415 1 .5423 1 -5430 1-5437 99 I -5445 1-5452 1 -5459 1.5467 1.5474 I. 5481 I -5489 I .5496 1-5503 1-5SII 100 I -5518 SUGAR AND SACCHARINE PRODUCTS. 619 TEMPERATURE CORRECTIONS TO SACCHAROMETER READINGS (STANDARD AT 20° C.).* Tempera- ture in Degrees Centigrade. 1556 (60° F.) 26 27 28 35 40 45 5° 55 60 Observed Per Cent of Sugar. 10 IS 20 25 30 35 40 45 50 55 60 70 Subtract from Observed Per Cent. 0.30 0.49 0.65 0.77 0.89 0. 99 I .08 1 .16 1 .24 I -31 I 3; I .41 I .44 0.36 0.47 0.56 0.65 0.73 0.80 0.86 0.91 0.97 I .01 1.05 I .08 I . 10 .32 0.38 0-43 0.48 0.52 O.S7 0.60 0.64 0. 67 . 70 0,72 0.74 0-75 0-31 0.35 0.40 0.44 0.48 0-51 0-S5 0.58 0.60 .63 0.6c 0.66 0.68 . 29 0.32 0.36 . 40 0.43 . 46 0. 50 0.52 0.54 . 56 0.58 0.59 . 60 . 26 . 29 0.32 0.35 0.38 0.41 0.44 0. 46 0.48 0.49 0-5I 0.52 053 . 24 . 26 . 29 0-3I 0-34 . 36 0.38 . 40 0.41 . 42 0.44 0.45 0.46 . 20 0. 22 0. 24 0. 26 0.28 0.30 0.32 0.33 0.34 0.36 o.3t 0-37 0.38 0.17 0. 18 20 0.22 0.23 0.25 . 26 0.27 0.28 0.28 . 29 0.30 0.31 0.13 0. 14 0.15 . 16 0.18 0.19 0. 20 . 20 . 21 0.21 0. 22 0.23 0.23 .09 . 10 . 10 . 1 1 0.12 0.13 0-I3 0. 14 0. 14 0.14 0. 1 1 0-I5 015 .05 0.05 0.05 .06 .06 . 06 .07 .07 . 07 0.07 . of- o.c8 0.08 . 1 1 0.12 0.12 0.14 0.15 0.16 0.16 0.17 0.17 0. 18 0. li 0.19 0.19 0. 18 . 2C 0.22 . 24 0.2f 0.28 c . 29 0.3c 0.30 0.32 0-33 0.33 0-34 Add to Observed Per Ce.n. 0.04 0.05 o.o5 0.06 0.06 .07 .07 0.07 . c 7 o.c8 c . c,'- c.c8 o.c8 . 10 0. 10 0. II 0. 12 0. 12 0-I3 0.14 . I.; c . 15 C . I s C. If, c. Ifc 0.16 0.16 0.16 0.17 0.17 0.19 0. 20 0.21 0.21 0.22 0.23 0.2. . 2; . 24 0.21 0. 22 0.23 0.24 0. 26 0.27 0.28 . 29 0. ?c 0-3I 0.32 0.32 0.32 0.27 0.28 0.3c 0-31 0.32 0.34 0-35 o.3h 0.38 0.38 0. 39 c . 3c . 40 0.33 0.34 o.3t 0.37 . 40 . 40 0.42 0,44 . 46 0.47 0.47 0.48 0.48 . 40 . 41 0.42 0.44 0.46 0.48 0. 50 0.52 O.S4 O.S4 0.5 = 0. 56 0.56 . 46 0.47 0.45 o-Si 0.54 . 56 0.58 . 60 0.61 . 62 0.63 0.6^ O.6.- 0.54 ■ 5 .S o.5f 0.59 0.61 0.63 0.66 0.68 . 70 . 70 0.71 0.72 0. 72 0.61 o.b2 0.63 0.66 0.68 0.71 0-73 . 76 0.78 0. 78 0.79 0.8c 0,8c 0.99 I .01 I .02 I .06 I . 10 1.13 I .16 I .18 I . 20 I . 2 I I . 22 I . 22 J -23 1.42 I -45 I .47 I-5I I -54 I -57 I . 60 1.62 I . 64 1.65 1.65 I. 6s 1.66 I .91 I -94 I . 96 2 .00 2.03 2 .05 2 .07 2 .09 2 . 10 2 . 10 2 . IC 2 . IC 2 . 10 2 . 46 2.48 2.50 2-53 2.56 2.57 2.58 2.59 2.59 2.58 2.5? 2-57 2.56 3-°5 3-07 3 09 3-12 312 312 3-12 3.11 3.10 3-o8 3 07 3 cs 3 03 3-69 3-72 3.73 3-73 3.72 3-7° 3-67 3.65 3.62 3.60 3-57 3.54 3SC 0-43 0.44 o.4f 0.48 0.5c 0.52 0. 54 . 56 0.58 0.58 0-59 . 60 . 60 •55 •47 •3S> •32 .16 .o& o. 20 0.34 0.09. 0.16 o . 24 0.32 039 0.48 0.56 o . 64 . 72 0.81 1 . 22 i^6s 2.08 2.52 2.97 3 -43 o . 60 *U. S. Dept. of Commerce and Labor, Bur. of Standards, Circular 19, 1909, p. 11. This table is calculated using the data on thermal expansion of sugar solutions by Plato (Wiss. Abh. der Kaiser- lichen Normal-Eichungs-Kommission, 2, 1900, p. 140), assuming the instrument to be of Jena 16'" glass. The table should be used with caution and only for approximate results v/hen the tempera- ture differs much from the standard temperature or from the temperature of the surrounding air. 620 FOOD INSPECTION AND ANALYSIS. plying the reading by 2, both direct and invert.* Use Clerget's formula for calculation of the sucrose. For medium- or light-colored grades of molasses, which yield but a small precipitate with lead subacetate, the above method of simple polarization, both direct and invert, gives results sufficiently accurate for ordinary work. For dark-colored, or "black-strap" molasses, or wherever extreme accuracy is required, the solution should be first made up to the mark and then clarified by the addition of a slight excess of anhydrous lead subacetate (p. 587), as proposed by Home, or else the double dilution method of Wiley should be em- ployed. Both methods make due allowance for the volume of the pre- cipitate. Double Dilution Method.\ — Take half the normal weight of the sample and make up the solution to 100 cc, using the appropriate clarifier. Take the normal weight of the sample and make up a second solution with the clarifier to 100 cc. Filter and obtain direct polariscopic readings of both solutions. Invert each in the usual manner and obtain the invert reading of the two. The true, direct polarization of the sample is the product of the two direct readings divided by their difference. The true invert polariza- tion is the product of the two invert readings divided by their dif- ference. Determination of Rafiinose in Beet Sugar Molasses. — For the deter- mination of sucrose and raffinose when present in the same solution, use the following formulas of Creydt : | 0.5188a — & Sucrose = (i) 0.8454 a—S and Raffinose = — 7— , ......... (2) 1.85 where fl=direct reading, 6 = rcading after inversion, and 5 = per cent of sucrose. * The short tube (loo mm.) is preferred for polarizing molasses, not only on account of the more or less deep color of the clarified solution, but also because a molasses sample con- taining considerable commercial glucose would not read within the scale limits, if the 200- .mm. tube were employed. t Wiley and Elwell, Analyst, 1896, 21, p. 184. X U. S. Dept. Agric, Bur. of Chcm., Bui. 107 (rev.), p. 43. SUGAR AND SACCHARINE PRODUCTS. 621 DavoU * recommends for purposes of clarification of the molasses the use of powdered zinc after inversion of the molasses sample according to Clerget's method. He adds i gram of the zinc to the sample after in- version while at the temperature of 69° C, allowing it to act for three to foi:r minutes at that temperature, after which he cools and filters, with the production of an almost colorless solution. Determination of Reducing Sugar. — {Estimated as Dextrose.) — Dilute 5 grams of molasses or syrup with water in a loo-cc. graduated flask, using 2 to 5 cc. normal lead acetate. Make up to 100 cc, filter, take an aliquot part of the filtrate (25 to 50 cc.) and make this up to 100 cc, the amount taken being such that, when diluted, the solution will contain not more than h% of dextrose. Since lead acetate has been used to clarify, add to the aliquot part taken and before dilution, enough sodium sulphate to precipitate the excess of lead, then filter and make up to the'ioo cc. mark. Determine the reducing sugar in this solution by either volumetric or gravimetric Fehling processes. U. S. Standard Molasses is molasses containing not more than 25% of water, nor more than 5% of ash. Adulteration of Molasses and Syrups.— A common adulterant of all these products is commercial glucose. From its water-white color and inert sweetness, no less than from its cheapness, it forms an admirable adulterant for dark-colored or low-grade molasses and syrups, counter- acting to a great extent by its smoothness the strong and often disagree- able taste of the inferior products with which it is mixed. Thus a grade of molasses too cheap to be ordinarily used for food purposes can be made to assume the appearance, and to some extent the taste, of the higher-priced and light-colored grades, by admixture with commercial glucose. Tin salts are also used to improve the color of low-grade or dark molasses, and bleaching agents, such as sulphurous acid, are frequently employed. Copper is sometimes found, due to utensils or vessels used in processes of manufacture. Lead may occur in maple syrup, due to the leaden plugs or spigots through which the sap is sometimes drawn from the trees. Detection and Determination of Commercial Glucose.f — From the direct polarization of a normal solution of molasses or syrup the presence * Jour. Am. Chem. Soc, 25 (1903), p. 1019. t Leach, ibid., p. 982. 62 2 FOOD INSPECTION AND ANALYSIS. or absence of commercial glucose can usually be established. The direct polarization of a normal solution of pure molasses should not be much in excess of 50° on the Soleil-Ventzke scale, while a pure, dark-colored molas- ses should polarize well under 40°. Golden syrup and maple syrup read higher than molasses, and a normal solution of pure maple syrup may have a direct polarization as high as 65°, being more often than not above 60°. An excessively high direct polarization is at once an indication of the presence of commercial glucose, while an invert reading at ordinar}^ room temperature to the right of the zero-point is an almost positive proof of its presence in either of the above products. The optically active constituents of commercial glucose, viz., dextrin, mahose, and dextrose, are present in such varying amounts, that it is impossible to determine accurately the exact amount of this adulterant in complex saccharine products which themselves contain components common to glucose. Its approximate amount can, however, be very satisfactorily estimated in molasses and syrups by the use of the follow- ing formula: (a-5)ioo ^ 175 ' where G=per cent of commercial glucose, a = direct polarization, and 5 = per cent of cane sugar previously obtained from the Clerget formula (p. 588). A large amount of invert sugar present affects the accuracy of this formula. It is especially applicable to maple syrup, wherein the per cent of invert sugar is small, but may be applied also to molasses and golden syrup, wherein the amount of invert sugar is not so large but that results may be obtained as close as could be expected from an empirical formula.f In saccharine products containing considerable invert sugar the invert reading at 87° C. obtained as directed on page 639, is divided by * Leach, U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 48. t This formula is based on the assumption that 42° Be. mixing glucose, the grade specially made and used for admixture with molasses, syrups, and honey, has a maximum polarization of 175° V. It was adopted as a result of investigations made some years ago by the author, but subsequently it appeared that 42° Be. mixing glucose po'.zrizes lower than formerly. Thus a sample recently examined by the author polarized at 162.4° V. Pending further investigations it seems best for the present to retain the old formula, for, while it^ undoubtedly gives low results, especially with higher admixtures of glucose, it approximates the truth more closely than would be expected, perhaps because it tends to compensate for the error due to substances in genuine molasses and honey that polarize to the right after inversion. Furthermore, it has been adopted by the A. O. A. C. To avoid misunderstanding, express results in terms of glucose polarizing at that factor. SUGAR AND SACCHARINE PRODUCTS. 623 the appropriate factor (163) to obtain tlie percentage of commercial glucose. While theoretically pure molasses and syrups would be expected to show no rotation when polarized at 87° C. after inversion, as a matter of fact most samples exhibit a decidedly right-handed reading at that temperature. Occasionally a zero reading is noted, and in rare instances a slight left-handed rotation occurs under the above conditions. Dextro-rotation is undoubtedly caused by some form of decomposition or fermentation. It may be due to a preponderance of dextrose in the reducing sugars, since levulose is more easily decomposed than dextrose, or it may be caused by the decomposition products formed when the raw juice is being defecated with lime, or again it might result from a special fermentation forming dextran. The following table shows results by A. H. Bryan* of polarization of samples of Louisiana molasses and syrup of known purity, showing especially the invert readings at 87° C: POLARIZATION OF LOUISIANA MOLASSES AND SYRUP. MOLASSES. SYRUP. Direct Corrected Invert Direct Corrected Invert Polariza- Polarization — Dry Polariza- Polarization — Dry Substance. tion at 20° C. Substance. at 20° C. At 20° C. At 87° C. At 20° C. At 87° C. ° V. ° V. ° V. Per Cent. ° V. ° V. °V. Per Cent. 40.8 — 20.24 + 2.2 80.8 48.4 -17.6 + 1.98 74.3 24.6 — 20.9 + 2.2 76.8 54-0 -18.7 + 3-3° 68.3 26.0 -18.26 + 3-52 76.8 50.2 — 12. 1 + 6.i6t 42.4 -16.94 + 2.42 78.2 50-4 -14-3 + 1.76 52-4 -16.28 + 2.20 69.1 61.8 -16.5 + 2.20 55.6 -13-59 + 4.18 69.6 39-6 — 18.04 + 2.20 80.8 39-6 -17.82 — 17.16 — 17.60 + 2.20 + 2.64 79.0 72.0 Average. Maximui + 2.65 + 6.16 44-0 Tl 42.0 + 2.42 73-8 76.1 Minim UE -17.27 + 3-52 a 0.00 42.4 / 41.6 -16.94 + 3.96 74.0 52-4 — 17.60 + 3-52 76.1 26.6 -19.8 0.00 78.1 50.8 -25.08 + 1.10 87. 5 22.6 — 16.72 + 3.96 84.1 41.6 -14.74 + I.IO 75-0 45-6 -iS-4 + 2.20 78.0 * A. O. A. C. Proc, 1908, U. S. Dept. of f Sample ropy and badly fermented. ;ric., Bur. of Chem., Bui. 122, p. 182. 624. FOOD INSPECTION /iND /IN A LYSIS. TYPICAL ANALYSES OF MOLASSES AND SYRUPS ADULTERATED WITH COMMERCIAL GLUCOSE. (a) Molasses {b) " (c) " {a) Golden drip syrup . . {h) " " ♦« .. (c) " " " .. (a) Maple syrup (ft) «' " (0 " " Polarization. 62 98.7 109.7 73-5 109.4 143-6 76.3 77-9 87.0 + 36-3 -f 71-9 + 90 + 39-8 + 87.6 + 136 + 7.6 ■f 24 + 30-6 18° 18° 17° 18° 17° 18.4° 18.6° i9» 22.4° 19 19.9 14-5 25 16.9 5-6 51 40.1 42.5 boQ "S ^ ^^^ 30-03 27.62 33-11 31 .61 33-44 38-17 16.90 M oj !ii.r:q JJ rfSE 3 •3 0) I. 5d(i^ 24.6 29.36 45 -o 27.98 54-4 22.02 27.7 23.67 52.8 24.48 78-5 21.52 14.4 31-91 21.6 23-44 25-4 28.80 3-83 3-53 2.67 3-94 2-51 1. 00 0.63 1.08 Determination of Dextrin. — According to Beckman's method a weighed amount of the honey or molasses is diluted with an equal volume of water and from ten to twelve times its volume of methyl alcohol is added. The precipitated dextrin is collected in a tared filter and thor- oughly washed with methyl alcohol, after which it is dried and weighed. Reduction of Saccharine Products to an Ash for Mineral Analysis. — If a considerable quantity of molasses, syrup, or other saccharine sub- stance is to be burnt to an ash, it is both tedious and annoying to ignite directly, by reason of the excessive swelling and frothing of such substances during ignition. Small quantities of molasses, syrup, or honey may with care be reduced to an ash by the method described on page 586. If a readily controlled electric current is available, it may be utilized as follows:* Mi.x 100 grams tf molasses, syrup, or other saccharine solution, which should be evaporated to syrupy consistency if not already such, with about 35 grams of concentrated sulphuric acid in a large porcelain evaporating-dish. An electric current is then passed through it while stirring, by placing one platinum electrode in the bottom of the dish near one side and attaching the other to the lower end of the glass rod, with which the contents are stirred. Begin with a current of about I ampere and gradually increase to 4.+ In from ten to fifteen minutes * Leach, 32d An. Rept. Mass. State Board of Health (1900), p. 653. Reprint, p. 37. This method is preferred to the ordinary method of heating with sulphuric acid, especially in case of molasses, because, if properly manipulated, it so quietly comes into the form of a very finely divided char or powder, especially adapted for subsequent quick ignition. t Modified from method of Budde and Schou for determining nitrogen electrolytically. Ztschr. anal. Chem., 38 (1899), p. 345. SUGAR AND SACCHARINE PRODUCTS. 625 the mass is reduced to a fine, dr}' char, which may then be readily burnt to a white ash in the original dish over a free flame or in a muffle. Or, 100 grams of the molasses or syrupy solution to be ashed may be first evaporated to dryness and afterward mixed with from 10 to 20 cc. of concentrated sulphuric acid in a porcelain evaporating-dish, or if the substance to be ashed be a dry sugar or confectionery, 20 grams are mixed "with the above amount of acid. Heat is gently applied by means of the gas flame till the swelling and frothing have ceased, which usually requires only a few minutes. The final ignition is then accomplished in the usual manner, nitric acid being added if necessary to completely destroy the organic matter. Determination of Tin in Molasses. — Fuse the ash from a weighed portion of the sample with sodium hydroxide in a silver crucible, dis- solve in water, and acidulate with hydrochloric acid; filter and precipi- tate the tin from this solution with hydrogen sulphide; wash the pre- cipitate on a filter and dissolve it in an excess of ammonium sulphide. Filter this solution into a tared platinum dish, and deposit the tin directly in the dish by electrolysis, using a current of 0.05 ampere and the appa- ratus described on page 608. Distinction between Invert Sugar, Maltose, and Lactose.* — All these sugars reduce Fehling's solution. Dextrose and levulose (invert sugar) when boiled with Barfoed's copper acetate solution (14 grams crystal- lized copper acetate and 5 cc. acetic acid in 200 cc. water) v/ill form a precipitate of cuprous oxide, while neither maltose nor lactose will do this. The solution, which has thus been tested for invert sugar and found to be free, or the filtrate from the cuprous oxide precipitate, is treated with an excess of basic lead acetate, filtered, and to the filtrate is added an excess of sodium sulphate solution to precipitate the lead. The solution is again filtered and treated with copper sulphate solution, if not already blue. It is then made alkaline with sodium hydroxide and heated to boiling. A red precipitate of cuprous oxide at this stage indicates either lactose or maltose or both. A solution of the sugar, made strongly ammoniacal, is then mixed with alkaline bismuth solution f and the container is set in a water- bath at 60° C. Maltose soon reduces the bismuth, but lactose does not. To test for lactose, add strong nitric acid to the solid sugar residue * Bartley and Mayer, Merck's Report, 12 (1903), p. 100. t This reagent is prepared as follows: Bismuth subnitrate, 2 grams; Rochelle salt, 4 grams; sodium hydroxide, 8 grams; dissolved in 100 cc. of water by the aid of heat. 626 FOOD INSPECTION AND ANALYSIS. and warm gently till red fumes come off. Then set the container in hot water and cool gradually. Crystals of mucic acid appear after a time if any appreciable amount of lactose be present. Determination of Lactose or Maltose. — Either sugar, if in solution free from other reducing sugars, may be determined by the volumetric Fehling method (iJ. 591) or by the Defren method, using the table on page 595- For the determination of maltose in commercial glucose, see page 630. Estimation of Cane Sugar and Dextrose in Mixtures. — Obtain true direct and invert readings of a normal solution of the mixture. Deter- mine the per cent of sucrose by Clerget's formula (p. 588). This figure represents the right-handed rotation due to sucrose. Subtracting this from the direct polarization, the difference represents the right-handed rotation due to dextrose. The specific rotary power of sucrose is 66.5 and that of dextrose 52.3. Calling d the percentage of dextrose and R' the right-handed rota- tion due to dextrose as above obtained, if the Soleil-Ventzke scale is used, 66.5:52.3 = ^:i?S whence 66. 5i?' d= 52-3 Determination of Levulose.* — On page 589 attention was called to the variation in the rotary power of levulose with the temperature. This variation is constant, and i gram of levulose in 100 cc. of water produces a decrease in left-handed reading of 0.0357° on the cane sugar (Ventzke) scale for each 1° C. increase in temperature. Therefore, the weight of levulose present in a given solution can be calculated from the polari- scopic readings at two temperatures, using a water- jacketed tube, as described on page 639. R-R "0.0357 (/-/'/ where I- = weight of levulose, i? = reading at higher temperature /, R = reading at lower temperature t'. The percentage of levulose present in the solution may readily be cal- culated as follows: * Wiley, Agric. Anal., p. 272. SUG/iR yIND SACCHARINE PRODUCTS. 62J "If V = percentage of levulose, L = weight of levulose in solution, IF == weight of sugar sample made up to 100 cc, LXioo In a normal solution 1^=26.048. ANALYSIS OF MAPLE PRODUCTS. Determination of Moisture. — This is accomplished by direct drying ■with sand, or by calculation from the specific gravity, or, preferably from the refractive index. See molasses methods, page 613. Determination of Ash. — Burn 5 grams in a platinum dish by the usual method,. observing the precautions given for molasses, page 614. Soluble and Insoluble Ash.^ — To the platinum dish containing the ash add 40 cc. of hot water and boil gently for two minutes. Filter through a small ashless filter, and wash with hot water until the filtrate amounts to 100 cc. Return the filter to the dish used for ashing, burn at a low red heat, cool and weigh, thus obtaining the insoluble ash. The soluble ash is obtained by ditTerence, subtracting the weight of insoluble from that of total ash. Alkalinity of Soluble Ash.-f — Allow the filtrate from the above deter- mination to cool, then titrate with tenth-normal hydrochloric acid, using methyl orange as an indicator. Alkalinity of Insoluble Ash.-f — Add excess of tenth-normal hydrochloric acid (usually 10 to 15 cc.) to the ignited insoluble ash in the platinum dish, heat to the point of boiling over an asbestos plate, allow to cool, and titrate excess of hydrochloric acid with tenth-normal sodium hydroxide, using methyl orange as an indicator. Express the alkalinity in each case as the number of cubic centimeters of tenth-normal acid used on the ash of i gram of sample. Polarization. — See page 614. Determination of Reducing Sugar. — See page 621. Determination of Malic Acid Value. — Modified Leach and Lythgoe Method. I — Weigh 6.7 grams of the sample into a 200 cc. beaker, and add * A, H. Bryan, U. S. Dept. of Agric, Bur. of Chem., Circ. No. 40, p. 6. t U. S. Dept. of Agric , Bur. of Chem., BuL 107 (rev.), p. 69. X Jour. Am. Chem. Soc, 26, 1904, pp. 380 and 1536; U. S. Dept. of Agric, Bur. of 'Chem., Bui. 107 (rev.), p. 74. 628 FOOD INSPECTION AND JN/t LYSIS. water to make a volume of 20 cc. Add 2 drops of ammonium hydroxide (specific gravity, 0.90), i cc. of a 10% solution of calcium chloride, and 60 cc. of 95% alcohol. Cover the beaker vi^ith a watch glass, heat for one-half hour on a water bath, then turn off the flame and allow the beaker to stand overnight. Filter the material in the beaker through good quahty filter paper, wash the precipitate with hot 75% alcohol until the filtrate measures 100 cc, dry and ignite. Add from 15 to 20 cc. of tenth-normal hydrochloric acid to the ignited residue, thoroughly dissolve the hme by heating carefully to just below boiling, cool and titrate the excess of acid with tenth-normal sodium hydroxide, using methyl orange as an indicator. One-tenth of the number of cubic centimeters of acid neutralized by the ignited residue expresses the malic acid value. Run blank determinations on reagents, using the same amounts, particularly of ammonium hydroxide, as were used in the original determination, and make the necessary correction. Determination of Lead Number. — Winton Method."^ — Weigh 25 grams of the material (or 26 grams if a portion of the filtrate is to be used for polarization) and transfer by means of boiled water into a loo-cc. flask. Add 25 cc. of standard lead subacetate solution, fill to the mark, shake, allow to stand at least three hours and filter through a dry filter. From the clear filtrate pipette off 10 cc, dilute to 50 cc, add a moderate excess of sulphuric acid, and 100 cc. of 95% alcohol. Let stand over night, filter on a Gooch crucible, wash with 95% alcohol, dry at a moderate heat, ignite at low redness for three minutes, taking care to avoid the reducing cone of the flame, cool, and weigh. Calcu- late the amount of lead in the precipitate, using the factor 0.6831, subtract this from the amount of lead in 2.5 cc. of the standard solution, multiply the remainder by 100, and divide by 2.5, thus obtaining the lead number. The standard lead subacetate is prepared by diluting one part of the ordinary solution (page 586) with four volumes of water, filtering if not clear. It is standardized by a blank determination conducted as above described. The solution deposits a slight precipitate on standing, but this does not usually appreciably affect its strength. Ross Modification.-\— This process is specially adapted for the exam- ination of mixtures of maple and cane sugar syrups, as the results are proportional to the per cent of maple syrup present, which is not true of the Winton method. The lead numbers of pure maple syrup range * Jour. Am. Chem. Soc, 28, 1906, p. 1204. t U. S. Dept. of Agric, Bur. of Chem., Circular 53. SUGAR AND SACCHARINE PRODUCTS. 629 from 1.8 to 3.0, whereas by the Winton method they range from 1.2 to 2.5. Transfer 25 grams of the syrup to a loo-cc. flask, using about 25 cc. of freshly boiled water, add 10 cc. of potassium sulphate solution (7 grams per liter), then 25 cc. of lead subacetate solution of the strength employed in the foregoing method. Make up to the mark with boiled water and proceed as in the Winton method. Run the blank in exactly the same way, substituting 25 grams of pure cane sugar syrup (66 grams of sucrose dissolved in 34 grams of water) for the maple syrup. Determination of Hortvet Number.* — Apparatus. — (i) A tube, 15.3. cm. in length, consisting of a wide cylindrical portion 3 cm. in diameter, narrowed at the top to a neck 2 cm. in diameter, and at the bottom to a. stem graduated in tenths to 5 cc. (2) A holder, made of pine or white wood, of a size adapted to carry the tube in the shield of the centrifuge. The holders and tubes should be arranged in balanced pairs in the centrifuge. Procedure. — Introduce 5 cc. of syrup or 5 grams of sugar into the tube. Add 10 cc. of water, and dissolve completely. Next add 10 drops of alumina cream, and 1.5 cc. of lead subacetate. Shake thoroughly, and allow to stand from forty-five to sixty minutes. Place the tube in its holder in the centrifuge shield, and run six minutes. If, after the end of this time, any material adheres to the sides of the wide part of the tube, loosen with a small wire or by giving the tube a slight twist, then run the tube six additional minutes, and finally read the volume of the- precipitate in the stem, estimating to o.oi cc. Run a blank with the above reagents in water, subtracting the blank reading from that of the precipitate. In the case of syrup, reduce ta the 5 -gram basis by dividing by the specific gravity of the sample. If the sugar content of the sample is known, the specific gravity can be calculated from the table on page 617. For pure maple syrup 1.33 is very nearly correct. The centrifuge used by Hortvet had a radius of 18.5 cm. and was run at a speed of 1600 revolutions per minute. The corresponding velocity in cm. per second {v) and revolutions per minute {R) for any given centri- fuge with a radius of r cm. may be calculated by the following formulae: v=^d' (2) The reducing power on Fehling's solution of dextrose is to that of maltose as 100 is to 62. Whence, if P= reducing sugar (reckoned as dextrose) we have P = (/+o.62m (3) Subtracting equation (2) from equation (i) we have P-P' = 53J^i38m . (4) * Wiley, Agric. Analysis, p. 290. 632 FOOD INSPECTION ^ND ^N^ LYSIS Multiplying equation (3) by 53 and subtracting from equation (4),, P-P' = 53^+ 138m, 53 i? = 53c?+ 32.86W, P-P'-53P = io5.i4W (5) Therefore m = ^^—, (6) 105.14 ' ^ ^ d = R — 0.62m, (7) P' d'^-— (8) 193 Determination of Dextrin in Commercial Glucose. — One volume of the sample is well shaken with about 10 volumes of 90% alcohol, and the precipitated dextrin is separated by filtration through a tared filter, washed thoroughly with strong alcohol, dried at 100°, and weighed. Qualitative Tests for Commercial Glucose, — Several confirmatory chemical tests may be employed for commercial glucose, aside from the optical test with the polariscope» Thus a precipitate of dextrin by treatment of the sample with an excess of strong alcohol, in the absence of mineral salts insoluble in alcohol, is strongly indicative of commercial glucose. An excess of sodium chloride in the ash also points strongly to the presence of glucose. Determination of Ash. — Formerly when sulphuric acid was used for conversion of the starch the ash consisted largely of calcium sulphate, but at present when hydrochloric acid is almost exclusively used the mineral matter is almost entirely common salt, formed by the neutralization of the acid. Determine ash by burning in a platinum dish at dull redness as in the case of other saccharine products. Qualitative or quantitative tests may be made for chloride, in the latter case calculating the equivalent amount of sodium chloride. If the amount of sodium chloride found does not equal the total ash, sulphates may be looked for. Determination of Sulphurous Acid. — At the present time glucose usually is free from an appreciable amount of sulphurous acid which formerly was extensively employed for bleaching. It may be determined by distillation, oxidation to sulphuric acid, and precipitation with barium chloride as described on page 840. SUGAR AND SACCHARINE PRODUCTS. 633 Detection of Arsenic. — Since the Manchester epidemic of arsenical poisoning, due to the consumption of beer prepared from glucose con- taminated through the sulphuric acid with this poison, it is highly important that both the acid used for conversion and the glucose be frequently tested for this contamination. The tests may be made on 2 to 5 grams of the materials without charring or destruction of the organic matter, by the Marsh test or the Sanger- Black-Gutzeit test as described under general methods on pages 74 to 77. The English limit of one and one-half parts per million calculated as metallic arsenic should not be exceeded. HONEY. Composition and Occurrence. — Honey is the saccharine product deposited by bees {Apis mellijica and A. dorsata) in the cells of honey comb, which the insect forms out of wax secreted by its body. Honey has its source chiefly in the nectaries of flowers, from which the bees abstract it, also in the juices of ripe fruits and the exudations of leaves (honeydew). While in the honey-sac of the bee, the sucrose, which forms the chief constituent of the fruit juice or nectar, becomes for the most part inverted, forming, in the honey, dextrose and levulose. The evaporation to a syrupy consistency is effected in the hive by exposure to a current of air, produced by fanning of the wings of the bees. The flavor of honey varies considerably, according to its source. Besides water, the sugars, and mineral matters, pollen is usually present, derived from the flowers, also as a rule a small quantity of wax, and nearly always appreciable amounts of various organic acids. Fincke f states real honey may or may not contain formic acid. European Honey. — Neufeld* gives the following limits for pure honey : Water 8.30 to 33.59% Protein 0.03 " 2.67% Invert sugar 49. 59 " 93 .96% Sucrose o.io " 10.12% Dextrin. o-99 " 9- 70% Formic acid O-03 " 0.21% Ash 0.02 " 0.68% * Der Nahrungsmittelchemiker als Sachverstandiger. , Berlin, 1907, p. 275. t Zeits. Unters. Nahr. Genuisra., 23, 1912, p. 255. 634 " FOOD INSPECTION /1ND ANALYSIS. Canadian Honey. — A large number of samples of genuine honey analyzed in 1897 for the Department of Inland Revenue, Canada (BuL. 47), showed the following variations: Direct polarization — 2.4 to — 19 Invert " —10.2 " —28 Sucrose (by Clerget) 0.5 " 7-64% Invert sugar 60.37 " 78.8% Water 12 '* 33% Ash 0.03 " 0.50% American Honey. — Browne* has examined 97 samples of American and Hawaiian honey, representing the product made from the nectar of numerous flowers as well as honeydew. Maxima and minima of polarizations and analyses of some of the more important kinds, and of all the levorotatory and the dextrorotatory samples are given in the table on page 635. As regards the chemical characteristics of honey from different flowers,. Browne states that alfalfa honey usually has less dextrin and undetermined matter— the so-called ' impurities " — and more sucrose than the other varieties, although the low amount of impurities is, to some extent, char- acteristic of the honey of the whole family (leguminosae) . The compositae yield honey with about the average amount of organic non-sugars; the rosaceas yield a product low in dextrin, but high in undeterminerl n: t^?r. Buckwheat and other polygonaceous honeys contain almost no sucrose, but give tests for tannins. Basswood honey is relatively high in dextrin, and that from poplar, oak, hickory and other trees, all of which contain considerable quantities of honeydew, are rich in both dextrin and ash. Pronounced tannin reactions are obtained in honey gathered from the flowers or plants of the sumac, hop and others rich in tannin. Tupelo, mangrove and sage honeys are distinguished by their high levulose content. Browne found the average per cent of water in honey from the arid states of Arizona, Nevada, Utah, and Colorado was 15.60, and from the humid states of Minnesota, Wisconsin, Illinois, Missouri and Iowa was 18.88. Hawaiian Honey. — This is characterized by its high ash and the presence of decided amounts of chlorides in the ash. Van Dinef states * U. S. Dep'i. of Agric, Bur. of Chem., Bui. no (1908). t Ibid., p. 52. SUGAR. AND SACCHARINE PRODUCTS. 635 •aSOJIXSQ SB ■pauiui -jajapufi <~0 ^O 1000 rt- O M 00 4 N 00 vC 4 «' ■uu^xaa ^? u-j O •qsv •asojong O o d d •jBgng 55 •J3;bj\^ M M LO On M O •+ 00 00 CO t^ 00 N 00 Tl- 'Oo^g t^ IT) + + « 00 + + + + 00 1-1 + + fOOO + + TOO O >0 <-C 00 OC +++ ++ ++ + + tn O "0 o°^ I I a. 1 I O "^ I I M r~ I I 00 ro M I I T T T CO ro Q\ HI I + II + I '3 0-8 r^jvC f T T vO i^ r~- -0 "-100 C< On • • + + CC 00 + + + + 'too 00 + + + \0 \n . ■ + + : : rO O >^ + + + + ^UB^SUOQ 00 O " I CN O 00 "^ T I -^ o T I 00 m 10 r^OO "^ " I T I I 00 ro "t d I I + + ■3 0°^ 1^ g^Bipaiuuij vo o 00 N i^ i^< J 4 m' I I I + + + •saiduiBg JO jaquinjij ^6 b3 B r< 1- C § ^ I =i ^ 5 3 ! 3^^:5^^1^i|l 3 — .si i G, c^ '■2 ."~> g-— g g S f= S .S-5 .£ ^ Oh o e p cj .a h rt •" >.^^ 636 FOOD INSPECTION AND ANALYSIS. that the floral honey of Hawaii is largely from the blossoms of the algarroba (Prosopis jidifera), while the honeydew honey, which, together with mixtures of honeydew and floral honey forms about two-thirds of the product of the Hawaiian Islands, comes largely from the exudations of the sugar-cane leaf-hopper {Perkinsiella saccharicida) , and the sugar- cane aphis {Aphis sacchari). Honeydew honey is dextrorotatory, and for this reason has often been condemned as adulterated. It has a strong molasses-like odor, and often a very dark color. Bakers prefer it to algarroba honey, because of its baking and boiling properties. The variation in the composition of Hawaiian honey is shown in the table on page 635, com])iled from Browne's data. Dextrorotatory Honey, — The U. S. standards define honey as levo- rotatory, thus excluding the larger part of the Hawaiian product, and also unimportant kinds of honey made from certain trees. Pure floral honey with no admixture of honeydew is seldom if ever dextrorotatory. The following are the results obtained by Browne in the examination of detrorotatory honeys: M c« >. u u ;urers did not intend it to be subjected to as high a temperature as 65°. They have, however, assured the author that if care be taken to bring the temperature very slowly and gradually to the required degree, 65°, and to avoid also sudden 'Cooling, the cement that secures the prisms in place will not be appreciably affected ; otherwise cracking or loosening of the cement would be liable to occur after a time. SUGAR AND SACCHARINE PRODUCTS. 645 At 65° C. pure beeswax should have a reading on the butyro-refrac-^ tometer of 30 to 31.5,* while that of paraffin is from 11 to 14.5.! CONFECTIONERY. The composition of confectionery is more complex than that of the saccharine products hitherto considered. As a rule, cane sugar, or one of its products, as molasses, forms the basis of most of the confections. Commercial glucose is also a common ingredient, while a large variety of such materials as eggs, butter, chocolate, various flavoring extracts, spices, nuts, and fruits, enter into the composition of confectionery. U. S. Standard Candy is candy containing no terra alba, barytes, talc, chrome yellow, or other mineral substances or poisonous colors or flavors, or other ingredients injurious to health. Adulteration. — Of late the adulteration of confectioner}'^ has been held largely in check by the National Confectioners' Association of the United States, which has fixed high standards of purity, and has been very zealous in restricting the use of harmful adulterants. Commercial glucose is not regarded as an adulterant of confectionery by the above-named association and by but few of the state laws. On the contrary, any ingredient, other than color, that has no food value, may logically be considered as an adulterant. Under this head are included such substances as paraffin, as well as make- weight mineral matters, such as terra alba, talc, or calcium sulphate. B. H. Smith J has called attention to the presence of arsenic in shellac used to coat certain kinds of confectionery. Colors in Confectionery. — A very wide range of colors is necessarily employed in the manufacture of confectionery, and the almost endless variety of coal-tar dyes now available lend themselves most readily to the confectioner's needs. Elsewhere, under "colors," lists of injurious and non-injurious dyes are given as compiled by the National Confec- tioners' Association, though it is not always readily apparent how the lines are drawn. The tinctorial power of these dyes is so high that the actual amount of substance contained in a thin coating of the color on the outside of the candy is exceedingly small, so that it is doubtful whether serious cases of injury have ever arisen from their use. * no, 1.4452 to 1.4463- t no, 1.4310 to 1.4335- % U. S. Dept. of Agric, Bur. of Chem., Circ. 91, 191 2. 646 FOOD INSPECTION AND ANALYSIS. Such was not the case formerly, before the prevalence of the coal-tar dyes, when such poisonous mineral pigments as chromate of lead were frequently used. Only one or two instances of the use of lead chromate in candy have come to the author's attention within ten years, since more satisfactory and harmless yellow colors among the azo-dyes are now obtainable. Analysis of Confectionery. — The following have been submitted by the author as provisional methods of procedure for the A. O. A. C.:* (i) Products of Practically Uniform Composition Throughout. — (a) Lozenges and Other Pulverizable Products. — Grind in a mortar or mill to a fine powder. For total solids, weigh from 2 to 5 grams of the powdered sample in a tared platinum dish, and dry in a McGill oven to constant weight. For Ash, ignite the residue from total solids in the original dish, ' observing the precautions given under sugar (p. 586), and molasses (p. 624). (b) Semi- plastic, Syrupy, or Pasty Products. — Weigh 50 grams of the sample into a 250-cc. graduated flask, mix thoroughly or dissolve, if soluble, in water, and fill to the mark. Be sure that the solution is uniform, or, if insoluble material is present, that it is evenly mixed by shaking before taking aliquot parts for the various determinations. For total solids and ash, measure 25 cc. of the above solution or mixture into a tared platinum dish, and proceed as directed under (a). (2) Confectionery in Layers or Sections of Different Composition. — When it is desired to examine the different portions separately, they should be separated mechanically with a knife, when possible, and treated as directed under (i). (3) Sugar-coated Fruit, Nuts, etc. — In case of a saccharine coating inclosing fruit, nuts, or any less readily soluble material, dissolve or wash off the exterior coating in water, which may, if desired, be evaporated to dryness for weighing, and proceed as in (i). (4) Candied or Sugared Fruits. — Proceed as in the exammation of fruits (Chapter XXI). Detection of Mineral Adulterants. — As in the case of molasses, a considerable quantity, say 100 grams, should be reduced to an ash for exammation for mineral adulterants, such as talc, calcium sulphate, and iron oxide, which are detected by regular qualitative tests. * U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 44. SUGAR AND SACCHARINE PRODUCTS. 647 Detection of Lead Chromate. — Fuse the ash in a porcelain crucible with a mixture of sodium carbonate and potassium chlorate, boil the fused residue with water, neutralize with acetic acid, fiher, and treat the filtrate with barium chloride or lead acetate solution. A yellow pre- cipitate indicates a chromate. Treat the insoluble part of the fusion with nitric acid, and test for lead in the usual manner. If a drop of ammonium sulphide be applied to a piece of confectionery colored with lead chromate, it will produce a black coloration. Determination of Ether Extract. — ^The ether extract includes the fat derived from chocolate, eggs, or butter, as well as any paraffin present. Measure 25 cc. of the 20% solution (i) {h) (p. 646) into a very thin, readily frangible glass evaporating-shell (Hoffmeister's Schdlchen), con- taining 5 to 7 grams of freshly ignited asbestos fiber; or, if impossible to thus obtain a uniform sample, weigh out 5 grams of the mixed, finely divided sample into a dish, and wash with water into the asbestos in the €vaporating-shell> using, if necessary, a small portion of the asbestos fiber on a stirring-rod to transfer the last traces of the sample from dish to shell. Dry to constant weight at 100°, after which cool, wrap loosely in smooth paper, and crush into rather small fragments between the fingers, carefully transferring the pieces with the aid of a camel's-hair brush to an extraction-tube, or to a Schleicher and Schull cartridge for fat extraction. Extract with anhydrous ether or with petroleum ether in a continuous extraction apparatus for at least twenty-five hours. Trans- fer the solution to a tared flask, evaporate the ether, dry in an oven at 100° C. to constant weight, and weigh. Determination of Paraffin. — Add to the ether extract in the flask, as above obtained, 10 cc. of 95% alcohol, and 2 cc. of i : i sodium hydroxide solution, cormect the flask with a reflux condenser, and heat for an hour on the water-bath or until saponification is complete. Remove the con- denser, and allow the flask to remain on the bath till the alcohol is evapo- rated off, and a dry residue is left. Treat the residue with about 40 cc. of water, and heat on the bath, with frequent shaking, tiU everything soluble is in solution. Wash into a separatory funnel, cool, and extract with four successive portions of petroleum ether, which are collected in a tared flask or capsule. Remove the petroleum ether by evaporation, and dry in the oven to constant weight. It should be noted that any phytosterol or cholesterol present in the fat would come down with the paraffin, but the amount would be so insignificant that, except in the most exacting work, it may be disregarded. 648 FOOD INP3ECT:0N AND ANALYSIS. The character of the final residue should, however, be confirmed br determining is melting-point and specific graviry, and by subjecting it lo examination in the butyro-rcfractometer. The m.elting-point of par- affin is about 54.5° C. ; its specific gravity at 15.5° C. is from 0.868 to 0.915, and on the but}To-refractometer the reading at 65° C. is from 11 to 14.5. Determination of Starch. — Measure gradually 25 cc. of a 20^ aqueous solution or uniform mixture of the sample inta a hardened filter or Gooch crucible, or transfer by washing 5 grams of the finely powdered substance to the filter or Gooch, and allow the residue on the filter to bccom.c air- dried. Extract ^^•ith five successive portions of 10 cc. of ether, then wash with 150 cc. of 10^ alcohol, and finally with 20 cc. of strong alcohol. Transfer the residue to a large flask and boil gently for four hours with 200 cc. of water and 20 cc. of hydrochloric acid (specific graA-ity 1.125), the flask being provided with a reflux condenser. Cool, neutralize with sodium hydroxide, add 5 cc. of alumina cream, and make up the volume to 230 cc. with water. Filter and determine the dextrose in an aliquot part of the filtrate by any of the various Fehling methods. The weight of the dextrose multiplied by 0.9 gives the weight of the starch. Polarization of Confectionery. — As a clarifier use either alumina cream or subacetate of lead, according to the nature and opacity of the sample. Ordinarily alumina cream is best, but in dark-colored samples, or those in which molasses has been used, it is sometimes necessary to employ the subacetate. \Mien starch is absent, and the sample is practi- cally soluble, polarize and invert in the usual manner Cp. 588). WTiere considerable starch or insoluble matter is present, use the double-dilution method of Wiley and E well (p. 620), thus making due allowance for the volume of the precipitate. Cane sugar, invert sugar, and dextrin, are determined as directed for honey. Commercial glucose is roughly determined by polarizing the sample at 87° C, as in the case of honey (p. 639). Confectioner}' is made in such a wide variety of forms, and these differ in consistency to such an extent that commercial glucose of all available degrees of density can be utOized to advantage in one product or another. In this respect confectioner}' is unlike honey and molasses, wherein a fairly uniform grade of commercial glucose is necessarily used for mixing, this grade being naturally selected with reference to its similarity in densitv to the molasses. On this account the glucose factor used SUGAR AND SACCHARINE PRODUCTS. 649 ior honey and molasses (175) may in some varieties of confectionery be too high. Determination of Alcohol in Syrups Used in Confectionery. — (Brandy- drops.) — Open each drop by cutting off a section with a sharp knife, and collect in a beaker the syrup of from 15 to 25 of the drops, which will usually yield from 30 to 50 grams of syrup. Strain the syrup into a tared beaker through a perforated porcelain filter-plate in a funnel to separate from particles of the inclosing shell, and ascertain the weight of the syrup. Wash into a distilling-flask, dilute with half its volume of water, and distil off into a tared receiving-flask a volume equal to the original volume of syrup taken. Ascertain the weight of the distillate and its specific gravity by means of a pycnometer. Multiply the per- centage by weight of alcohol corresponding to the specific gravity, as found in the tables on page 661 et seq., by the weight of the distillate, and divide this by the weight of syrup taken. The result is the per cent by weight of alcohol in the syrup. Detection of Colors. — It is sometimes necessary to macerate a con- siderable mass of the material to remove the color, which is, however, in the majority of cases readily soluble. The insoluble colors are nearly all mineral pigments to be looked for in the ash, as in the case of chromate of lead (p. 647). Frequently the coloring matter is confined to a thin ■outer layer, which is readily washed off. The solution of the dyestuff is examined as directed under colors. Detection of Arsenic. — Arsenic may be present through impure coloring-matter. If the color is confined to an exterior coating, this should be washed off and examined. If distributed through the mass, a solution of the whole should be taken. Examine for arsenic by the Gutzeit or Marsh method, as directed on pp. 74 to 77. 650 FOOD INSPECTION AND yINALYSIS. REFERENCES ON SUGARS. Babington, F. W. Sugars, Syrups, and Molasses. Can. Inl. Rev. Dept., Bui. 25- Maple Syrup. Can. Inl. Rev. Dept., Bui. 45. Bartley, E. H., and Mayer, J. L. Identification of Carbohydrates. Merck's Report, 12, 1903, p. 100. Brown, H. T., Morris, G. H., and Millar, J. H. Experimental Methods Employed in the Examination of the Products of Starch Hydrolysis by Diastase. Jour. Chem. Soc. Trans., 71 (1897), p. 72. Browne, C. A. The Analysis of Sugar Mixtures. Jour. Am. Chem. Soc, 28, 1906, P- 439- Chemical Analysis and Composition of American Honeys. U. S. Dept. of Agric, Bur. of Chem., Bui. no. The Unification of Saccharimetric Observations. A.O.A.C. Proc. 1908, p. 221. A Handbook of Sugar Analysis. New York, 1912. Bryan, A. H. The Estimation of Dry Substance by the Refractometer in Liquid Saccharine Food Products. Jour. Am. Chem. Soc, 30, 1908,. p. 1443. Methods for the Analysis of Maple Products and the Detection of Adulterants,. together with the Interpretation of Results Obtained. U. S. Dept. of Agric,. Bur. of Chem., Circ No. 40. • Maple Sap Sirup. U. S. Dept. of Agric, Bur. of Chem., Bui. 134. Chemical Analyses and Composition of Imported Honey from Cuba, Mexico, and Haiti. U. S. Dept. of Agric, Bur. of Chem., Bui. 154, 191 2. DOOLITTLE, R. E., and Seeker, A. F. The Possibilities of Muscovado Sugar as an Adulterant for Maple Products. A. O. A. C. Proc! 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 196. • Notes on the Winton Lead Number of Mixtures of Cane and Maple Syrup. Ibid., p. 198. Fresenius, W. Der Starkesirup bei Zubereitung von Nahrungs- und Genussmitteln. Zeits. Unters. Nahr. Genuss., 2, 1899, pp. 35 u. 279. Fruhling, R. Anleitung zur Untersuchung der fiir die Zuckerindustrie. 6th ed. Braunsweig, 1903. HiLTNER, R. S., and Thatcher, R. W. An Improved Method for the Rapid Estimation of Sugar in Beets. Jour. Am. Chem. Soc, 23, 1901, p. 299. HoRNE, W. D. The Chemical Determination of Sulphites in Sugar Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 105, 1906, p. 125. HoRTVET, J. The Chemical Composition of Maple-Syrup and Maple-Sugar, Methods of Analysis, and Detection of Adulteration. Jour. Am. Chem. Soc, 26, 1904,, P- 1523- SUGAR AND SACCHARINE PRODUCTS. 651 Jones, C. H. Detection of Adulteration in Maple Sugar and Maple Syrup. Vt. Agric. Exp. Sta. Rep., 1903, p. 446. Maple Syrup and Maple Sugar Investigations with Particular Reference to the Detection of Adulteration. Vt. Agric. Exp. Sta. Rep., 1904, p. 315- Landolt, H. Handbook of the Polariscope and its Practical Applications,. 1882. Trans, by Long, J. H. Optical Rotation of Organic Substances. Easton, 1902. Leach, A. E. The Determination of Commercial Glucose in Molasses, Syrups and Honey. Jour. Am. Chem. Soc, 25, 1903, p. 982. Saccharine Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 43. Lock and Newlands. A Handbook for Planters and Refiners. London, 1888. Macfarlane, T. Honey. Can. Inl. Rev. Dept., Bui. 45. MuNSON, L. S., and Walker, P. H. The Unification of Reducing Sugar Methods. Jour. Am. Chem. Soc, 28, 1906, p. 663. Robin, L. Sucres. Analyse des Matieres Alimentaires (Girard et Dupre), p. 525. Paris, 1894. Ross, S. H. Suggested Modification of the Winton Lead Number, Especially as Applied to Mixtures of Maple and Cane Sugar Sirups. U. S. Dept. of Agric, Bur. of Chem., Circ. 53. Roth, H. L. A Guide to the Literature of Sugar. London, 1890. Sachsse, R. Die Chemie der Kohlenhydrate. Leipzig, 1877. Sawyer, H. E. The Commercial Analysis of Molasses. Jour. Am. Chem. Soc, 27, 1905, p. 691. Shutt, F. F., and Charron, A. T. Determination of Moisture in Honey. Trans. Royal Soc. Canada, 2d Series, 1902-3, 7, Section 3. SiDERSKY, D. Traite d' Analyse des Matieres Sucrees. Paris, 1890. Spencer, G. L. Handbook for Sugar Manufacturers and their Chemists. New York, 1905. Steydn, E. Die Untersuchung des Zuckers und Zuckerhaltiger Stoflfe. Leipzig, 1893. Sy, a. p. Note on the Examination of Maple Products — The Lead Value. J. Frank. Inst., 162, p. 71. • Three New Preliminary Tests for Maple Products. Jour. Am. Chem. Soc, 30,, 1908, p. 1429. ToLLENS, B. Handbuch der Kohlenhydrate. Breslau, 1888. Tolman, L. M., and Smith, W. B. Estimation of Sugars by Means of the Refrac- tometer. Jour. Am. Chem. Soc, 28, 1906, p. 1476. Tucker, J. H. Manual of Sugar Chemistry. New York, 1890. Walker, P. H. The Unification of Reducing Sugar Methods. Jour. Am. Chem. Soc, 29, 1907, p. 541. Weichmann, F. S. Sugar Analysis. New York, 1890. Wein, E. Tabellen zur quantitativen Bestimmung der Zuckerarten. • Trans, by Frew, W. Tables for the Quantitative Estimation of the Sugars. London, 1896. 652 FOOD INSPECTION AND ANALYSIS. Wiley, H. W. Sugar, Molasses and Syrup, Confections, Hjneyand Beeswax. U. S. Depth of Agric, Div. of Chem., Bui. 13. part 6. The Influence of Temperature on the Specific Rotation of Sucrose and Method of Correcting Readings of Compensating Polariscopes Therefor. Jour. Am. Chem. Soc, 21, 1899, p. 568. WiNTON, A. L., and Kreider, J. Lehn. A Method for the Determination of Lead Number in Maple Syrup and Maple Sugar. Jour. Am. Chem. Soc, 28, 1906, p. 1204. YoDER, P. A. Ueber das Vorkommen von Formaldehyd in Zuckerfabriks-erzeugnissen. Zeits. Unters. Nahr. Genuss., 20, 1910, p. 208. A Polariscopic Method for the Determination of Malic Acid and its Applica- tion in Cane and Maple Products. Jour. Ind. Eng. Chem., 3, 191 1, p. 563. Notes on the Determination of Acids in Cane Juice. Jour. Ind. Eng. Chem., 3, 1911, p. 640. Young, W. J. A Miscroscopic Study of Pollen. U. S. Dept. of Agric. ^ Bur. of Chem., Bui. no. CHAPTER XV. ALCOHOLIC BEVERAGES. Alcoholic Fermentation. — In a broad sense all alcoholic liquors are saccharine products, in that they are essentially the result of the fermen- tation of sugar. In the case of fruits, the sugar already exists as such in their -juices, which, when expressed, almost immediately on exposure to the air begin to undergo spontaneously the process of alcoholic fermen- tation, in accordance with the reaction: (1) C6Hi206=2C,H60+2C02. Dextrose or Alcohol Carbon grape sugar dioxide In the case of grains the process is more complex, involving a preliminary saccharous fermentation, whereby the starch is first transformed into sugar. Thus (2) 2CeH,oO,+ H20 = CeH,o03 + C«H^Oe. Starch Dextrin Dextrose (3) CeH,oO,+ H,0 = CeH,30e. Dextrin Dextrose The process of alcoholic or vinous fermentation is largely dependent upon the presence of various species of yeasts, which either exist from the first in the expressed juices themselves, as in the case of wines, being derived from the skins of the grapes and from the air, or are introduced with some degree of selection, as in the case of beer. In the juices of most fruits the sugar exists in the form of sucrose, mixed vdth variable amounts of invert sugar resulting from the inver- sion of the sucrose due to the action of ferments, such as invertase, a soluble ferment of yeast. The invert sugar nearly always predominates, and in some juices, as for instance the grape, nearly all the sugar has been inverted. 653 654 FOOD INSPECTION AND ANALYSIS. The above reaction, No. i, illustrating the splitting up of grape sugar into alcohol and carbon dioxide, does not represent the practical yield of alcohol under ordinary conditions that occur in vinous fermentation, for, as a matter of fact, instead of 51.11 parts of alcohol and 48.89 parts carbon dioxide, which would theoretically result as above from the fer- mentation of 100 parts of dextrose, only about 95% of the theoretical yield can be obtained, so that in practice it is possible to form but about 48.5% alcohol and 46.5% carbon dioxide. The balance, amounting to some 5%, consists chiefly of glycerin, succinic acid, and traces of various compounds, including some of the higher-boiling alcohols (propyl, butyl, and amyl) and their ethers, which form the fusel oil of the dis- tilled liquors. Vinous fermentation takes place most readily in slightly acid liquids, at a temperature ranging from 25° to 30° C. It is convenient to divide alcoholic beverages into two main groups, first the fermented and second the distilled liquors. The fermented liquors naturally subdivide themselves into {a) the products of the direct spontaneous fermentation of saccharine fruit juices, such, for example, as those of the apple and the grape, to form cider and wine respectively, and {h) the malted and brewed liquors,, such as beer and ale, produced by the conversion of the starch of grain into sugar, and the final alcoholic- fermentation of the latter. The distilled liquors include such products as whiskey, brandy, rum,, and gin, wherein alcoholic infusions prepared by previous fermentation in various ways are further subjected to distillation. Alcoholic Liquors and State (or Municipal) Control. — The mere- adulteration of liquors does not constitute the only feature which brings, them within the scope of the public analyst's work and renders them especially amenable to stringent laws. Indeed, it is often a far more important question for the analyst to decide by his results whether or not the samples submitted to him, by police seizure or otherwise, are sold in violation of the regulations in force in his particular locality govern- ing the liquor traffic. A common regulation in no-license localities fixes the maximum per cent of alcohol which shall decide whether or not a liquor is legally a temperance drink, and can be sold as such with impunity. From its low- content in alcohol, an analyst's findings regarding a certain sample may exonerate the dealer suspected of violating this law, while yet by the very reason of its being low in alcohol the same sample would be placed ALCOHOLIC BEVERAGES. O55 in the adulterated list as regards non-conformance to a standard of purity. While the raising of revenue is one purpose for the existence of these laws bearing on liquor license, an equally important object sought to be gained is doubtless the repression of intemperance. Toxic Effects. — A popular impression seems to exist that the toxic effects of an adulterated liquor are far worse from a temperance stand- point than those of a sample of good standard quality, and it is a common experience of the public analyst to have submitted to him by well-mean- ing temperance advocates samples which are alleged to have caused the worst forms of intoxication, and are thus suspected of being impure. As a matter of fact the chief adulterants of liquors are water, sugar, and, in the case of beer, various bitter principles and vegetable extractives, none of which are on record as being in themselves actively toxic* Alcohol is the one ingredient of liquor which, more than any other, produces a marked physiological effect. IMany liquors, especially those of the distilled variety classed as adulterated, are so considered by reason of their low alcoholic content through watering or otherwise, hence this commonest form of adulteration, far from being detrimental in itself, is actually helpful to the temperance cause. Details of Liquor Inspection. — The same precautions should be carefully observed by officers making seizures of liquors for analysis, as by food inspectors, regarding safe delivery of the samples to the analyst. The following instructions are circulated by the State Board of Health of Massachusetts, which has in charge the inspection of liquors, concerning the taking of samples in that state and the transmission to the analyst: DIRECTIONS FOR TAKING SAMPLES FOR ANALYSES. The officer making a seizure, or taking samples of beer, should note at the time of such seizure the general appearance of the liquor, — as to whether it is clear or cloudy, whether it is still or has a strong head. If the liquor is in bottles, take at least one pint bottle; if in barrels, draw a pint bottle from each. Request the owner to seal each sample taken. If the bottles have cork stoppers, cut the stoppers off level with the top of the bottle and cover with wax; if with patent stoppers, a little wax placed upon the wire at the point where it lays against the neck of the bottle is sufficient. If the owner refuses to seal it, then the officer * The writer refers to substances intentionally added, and not to accidental impurities, such as arsenic, etc., that are occasionally *^ound. 656 FOOD INSPECTION AND ANALYSIS. should seal it in his presence, calling his attention to the fact. Before leaving the premises, place upon the bottle a label or tag, with the date, the name of the owner, and the name of the officer upon it, and also the name of the town or city. Then place in a box, with the certificate required by law, and forward without delay to the analyst. FORM OF LABEL. Town Date of seizure 19 Owner Kind of liquor Brewer Accompanying each sample is a certificate like the following, the first part of which is filled out and signed by the officer, wliile the second part, containing the data of analysis, is filled out and signed by the analyst and returned by him to the officer. Such a certificate is nearly always accepted as evidence in court without the personal appearance of the analyst. ss 19 . To the State Board of HeaUh: I send herewith a sample of .; taken from liquors seized by me 19 . Ascertain the percentage of alcohol it contains, by volume, at sixty degrees Fahrenheit, and return to me a certificate herewith upon the annexed form. ^ Seized from Officer. COMMONWEALTH OF MASSACHUSETTS. No Office of the State Board of Health. Boston, 19 . * This is to certify that the received by me with the above statement contains per cent of alcohol, by volume, at sixty degrees Fahrenheit. '"^ Received 19 • Analysis made 19 . [seal.] Analyst State Board of Health. /tLCOHOLIC BEVERAGES. 657 A convenient method for recording analyses is by the employment of numbered library cards, which bear the same number as the certificates and are kept by the analyst. The following is a convenient form: No Analyzed County Wt. flask and ale City or town Wt. flask Officer Wt. ale Defendant .Sp. gr. ale. (60°) Address Per eent alcohol Kind of liquor Reported Seized Received. How delivered Sealed Condition Kind of bottle Registered METHODS OF ANALYSIS COMMON TO ALL LIQUORS. Specific Gravity. — This should be taken at 15.6° or calculated to that temperature. The most convenient mode of procedure is to bring the temperature of the sample somewhat below that point by allowing the flask containing it to stand in cold water, and to have everything in readiness to make the determination when 15.6° temperature has been reached, either by the hydrometer spindle in a glass cylinder, by the Westphal balance, or by the pycnometer. The latter is by far the most accurate, especially if it is of the form which is fitted with a thermometer- stopper. Detection of Alcohol.^It is rarely necessary to make a qualitative test for alcohol in liquors, since it is almost invariably present even in many of the so-called temperance drinks, at least in small amount. Indeed in many localities a beverage is legally a temperance drink that contains not more than 1% alcohol by volume. The lodojorm Test. — Alcohol, when present in aqueous solution to the extent of 0.1% or more, may be detected by the iodoform test. The solution is warmed in a test-tube with a few drops of a strong solution of iodine in potassium iodide, after which enough sodium hydroxide solution is added to nearly decolorize. On standing for some time a yellow precipitate of iodoform will appear if alcohol be present, or at once if there is a considerable amount, and the characteristic odor of iodoform will be rendered apparent, even when the precipitate is so slight as to be almost imperceptible. This iodoform precipitate is crystalline, showing under the microscope as star-shaped groups or hexagonal tablets. 653 FOOD INSPECTION AND ANALYSIS. It should not be forgotten that other substances than alcohol give the reaction, as lactic acid, acetone, and various aldehydes and ketones. Pure methyl or amyl alcohol or acetic acid do not thus react. Bert helot recommends benzoyl chloride as a reagent for detecting alcohol. By warming a mixture of a few drops of benzoyl chloride with the solution to be tested, and adding a little sodium hydroxide, ethyl benzoate is formed, recognizable by its distinctive odor. This reaction is delicate to 0.1% alcohol. The presence of other alcohols than ethyl produces ethers of characteristic odor. Hardy^s Test for Alcohol consists in shaking the aqueous solution with some powdered guaiacum resin, filtering, and adding to the filtrate a little hydrocyanic acid and a drop of dilute copper sulphate solution. A blue coloration considerably deeper than that due to the copper salt is indicative of alcohol. Methyl Alcohol in spirits is tested for as described on pp. 749-752. Determination of Alcohol. — In the case of carbonated Hquids it is necessary to first expel the free carbon dioxide, which is readily accom- plished by pouring the liquor back and forth from one beaker to another, from time to time removing the excess of froth from the top of the vessel by the aid of the hand. Or, the sample may be shaken vigorously in a large separatory funnel, and the still liquor drawn off from below the froth, repeating the operation several times if necessary. In either case the mechanical treatment should be continued till the liquor is com- paratively quiet and free from foam. (i) By Distillation. — This is by far the most accurate method of determining alcohol, and should be carried out in all cases where any legal controversy is apt to be involved. Into a flask of 250 to 400 cc. capacity introduce a convenient quantity of the hquor, which should be accurately weighed or measured, according to whether the percentage by weight or measure is desired. The following are suitable quantities; Distilled hquors, 25 grams or cc; cordials, 25 to 50 grams or cc; wines, ciders, and malt liquors, 100 grams or cc. In the case of wines or ciders which have undergone acetic fermentation, add o.i to 0.2 gram of precipitated calcium carbonate or neutralize with standard alkali. Dilute the liquid to 150 cc. and distil into a loo-cc flask. Nearly all alcoholic liquors, if comparatively free from carbon dioxide, will boil without undue frothing or foaming. New wine will occasionally give trouble in this regard, but foaming may usually be prevented in this ALCOHOLIC BEVERAGES. 659 'Case by the addition of tannic acid. In case of wine, cider, and beer all the alcohol will have passed over in the first 75 cc. of the distillate, ■or three-fourths the original measured volume, but with distilled liquors high in alcohol the process had better be continued till nearly 100 cc. or the original volume taken have passed over. If the condenser is of glass, one can observe when all the alcohol has been distilled over, for the reason that the mixed alcohol and water vapors in the upper portion of the con- •denser present a striated or wavy appearance, readily apparent so long .as the alcohol is passing over, while after all the alcohol has been distilled, the condenser-tube appears perfectly clear. The distillation is thus : continued for some time after this striated appearance has ceased. The distillate in the receiving glass is finally made up to the mark or to the ■original volume of the liquor taken. Strictly speaking, the measure- ments before and after distillation should be made at 15.6° C, but, except- ing in case of distilled liquors, no appreciable error results from making both measurements at the same or room temperature. Another precau- tion formerly thought necessary was to have the delivery-tube from the condenser pass below the level of a little water in the receiving-flask from the start, but equally accurate results have been obtained by simply allowing the end of the condenser-tube to enter the narrow-necked flask. Fig. 112 shows a bank of six stills of the kind used in the author's laboratory for alcohol determination in liquors. In each still the verti- cal glass worm-condenser, the round-bottomed distilling-flask, and the lamp, are supported by rings held by a single upright rod. The receiving- flask is readily connected with the condenser by means of a single bent tube provided with a rubber stopper. The cold-water pipe supplying the condensers is shown at the top, and the gas-supply pipe at the bottom. The distillate, made up to 100 cc, is thoroughly shaken and its specific gravity taken at exactly 15.6° in a pycnometer, or by the Westphal balance. From the specific gravity the corresponding percentage of alcohol by weight or volume, or the grams per 100 cc. in the distillate, is ascertained by reference to the accompanying tables. To obtain percentage of alcohol by weight in the sample, multiply the per cent by weight in the distillate by the weight of the distillate, and divide by the weight of the sample taken; to obtain per cent by volume, multiply the per cent by volume in the distillate by 100, and divide by the volume of the sample used. (2) From the Specific Gravity of the Sample. — In the case of dis- tilled liquors having very little residue, an approximation to the true 66o FOOD INSPECTION /iND ANALYSIS. percentage of alcohol may be obtained by using the alcohol table in con- nection with the specific gravity of the liquor itself. The accuracy of this method depends largely on the freedom from residue, being absolutely correct for mixtures of alcohol and water only. (3) By Eva poral ion. ^Determine the specific gravity of the sample, evaporate a measured portion of the liquor (50 or 100 cc.) in a porcelain V FiG. 1 1 2. — Bank of Stills for Alcohol Determination. dish over the water-bath to one-fourth its bulk, make up to its original volume with distilled water, and determine the specific gravity of this second or dealcoholized portion. Add i to the original specific gravity, and from this subtract the second specific gravity. The difference is the specific gravity corresponding to the alcohol in the liquor, the per cent of which is found from the table. Example. — Suppose the specific gravity of the original sample to be 0.9Q00 while that of the dealcoholized sample is 1.0009. Then 1.9900 — 1.0009 = 0.9891. .*. Per Cent by volume of alcohol = 8.io. /tLCOHOLIC BEyER/IGES. 66t SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL. (According to Hehner.) Spec. Absolute Alcohol. Spec. Absolute Alcohol. Spec. Absolute Alcohol. Grav. at 15.6° C. Per Cent Per Cent Grams Grav. at 15.6° C. Per Cent Pel Cent Grams Grav. at 15.6° C. Per Cent Per Cent Grams by by Vol- per by by Vol- per bv by Vol- per Weight ume. Weiiht ume. 100 cc. Weight ume. 100 cc_ I. 0000 0.00 0.00 0.00 0.9999 0.05 0.07 0.05 0-9959 2-33 2-93 2.32 0.9919 4.69 5-86 4-65 8 O.II 0.13 O.II 8 2-39 3.00 2.38 8 4-75 5-94 4.71 7 0.16 0.20 0.16 7 2-44 3-07 2-43 7 4.81 6.02 4-77 6 -0.21 0.26 0.21 6 2.50 3-14 2-49 6 4-87 6.10 4.83 5 0.26 0-33 0.26 5 2.56 3-21 2.55 5 4-94 6.17 4.90. 4 0.32 0.40 0.32 4 2.61 3-28 2.60 4 5.00 6.24 4-95 3 0-37 0.46 0-37 3 2.67 c,-iS 2.65 3 5.06 6.32 5.01 2 0.42 0-S3 0.42 2 2.72 3-42 2.70 2 5-12 6.40 5-or I 0.47 0.60 0-47 1 2.78 3-49 2.76 I 5.19 6.48 5-14 0-53 0.66 0-53 2-83 3-55 2.81 5-25 6-55 5.20 0.9989 0.58 0-73 0.58 0.9949 2.89 3.62 2.87 0.9909 5-31 6.6^ 5.26 8 0.63 0.79 0.63 8 2.94 3-69 2.92 8 5-37 6.71 5-32 7 0.63 0.S6 0.68 i 7 3.00 3.76 2.98 7 5-44 6.78 5-39' 6 0.74 0-93 0.74 1 6 3.06 3-83 3-04 6 5 -.50 6.86 5-45 5 0.79 0.99 0.79 \ 5 3.12 3-90 3.10 5 5-56 6-94 5-51 4 0.84 1.06 0.84 \ 4 3.18 3-98 3-i6 4 5.62 7-01 5-57- 3 0.89 1-13 0.89 ! 3 3-24 4-05 3.22 3 5-69 7.09 5-64 2 0-9S 1. 19 0-95 ! 2 3-29 4-12 3-27 2 5-75 7.17 5-70 I I. CO 1.26 I. CO ,' I 3-35 4.20 3-i3 I 5.81 7-25 5.7^ 1.06 1-34 1.06 3-41 4-27 3-39 5-87 7-32 5.81 0.9979 I .12 1.42 I. 12 0.9939 3-47 4-34 3-45 0.9899 5-94 7.40 5-88 8 I. 19 1-49 I. 19 8 i-S5 4-42 3-51 8 6.00 7-48 5-94 7 1-25 1-57 1.25 7 3-59 4-49 3-57 7 6.07 7-57 6.01 6 I. 31 1.65 I-3I 6 3-65 4.56 3-63 6 6.14 7.66 6.07- 5 1-37 I -.73 1-37 5 3-71 4-63 3-69 5 6.21 7-74 6.14 4 1-44 1-81 1-44 4 3-76 4-71 3-74 4 6.28 7-83 6.21 3 1-50 1.88 1-50 3 3.82 4.78 3-80 3 6.36 7.92 6.29 2 i.t;6 1.96 i-';6 2 3. 88 4-85 3-85 2 6-43 8.01 6.36 1 1.62 2.04 1. 61 I 3-94 4-93 3-91 I 6. so 8.10 6-43 1.69 2.12 1.68 4. CO 5.00 3-97 6-57 8.18 6.50 0.9969 1-75 2.20 1.74 0.9929 4.06 S-08 4-03 0.9889 6.64 8.27 6.S7 8 i.8i 2.27 1.80 8 4.12 5.16 4.09 8 6.71 8.36 6.63 7 1.87 2-35 1.86 7 4.19 5-24 4.16 7 6-78 8-45 6.70 6 1-94 2-43 1-93 6 4-25 5-32 4.22 6 6.86 8-54 6.78 5 2. CO 2-51 1.99 5 4-31 5-39 4.28 5 6.93 8-63 6.85 4 2.06 2.58 2-05 4 4-37 5-47 4-34 4 7.00 8.72 6.92 3 2. II 2.62 2.10 3 4-44 5-55 4.40 3 7.07 8.80 6-99 2 2.17 2.72 2.16 2 4-50 5-63 4.46 2 7-13 8.88 7-05 I 2.22 2-79 2.21 I 4-56 5-71 4-52 I 7 20 8.96 7.12 2.28 2.86 2.27 4.62 5-7S 4.58 c 7.27 9.04 7.19 662 FOOD INSPECTION AND ANALYSIS. SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (CoM/znuetf). Absolute Alcohol. Spec. Absolute Alcohol. Absolute Alcohol. Spec. Spec. , , Grav. at 15-6° C. Per Cent Per Cent Grams Grav. at 15.6° C. Per Cent Per Cent Grams Grav. at Per Cent Per Cent Grams by by Vol- per by by Vol- per iS-6''C. by by Vol- per Weight ume. 100 cc. Weight ume. 100 cc. Weight ume. 100 cc* 0.9879 7-33 9-13 7.24 0.9829 10.92 13-52 10.73 0.9779 14.91 18.36 14.58 8 7.40 9.21 7-31 8 11.00 13.62 10.81 8 15.00 18.48 14.66 7 7-47 9.29 7-37 7 11.08 13-71 IO-89 7 15.08 18.58 14-74 6 7-53 9-37 7-43 6 11.15 13.81 10.95 6 15-17 18.68 14-83 5 7.60 9-45 7-50 5 11.23 13-90 11.03 5 15-25 18.78 14.90 4 7.67 9-54 7-57 4 11.31 13-99 11.11 4 15-33 18.88 14-98 3 7-73 9.62 7-63 3 11.38 14.09 II. 18 3 15-42 18.98 15-07 2 7.80 9.70 7.70 2 11.46 14.18 11.26 2 15-50 19.08 15-14 I 7.87 9.78 7-77 I 11-54 14.27 11-33 I 15-58 19.18 15.21 7-93 9.86 7-83 11.62 14-37 II. 41 15-67 19.28 15-30. 0.9869 8.00 9-95 7.89 0.9819 11.69 14.46 11.48 0.9769 15-75 19-39 15-38 8 8.07 10.03 7.96 8 11.77 14.56 11.56 8 15-83 19.49 15.46 7 8.14 10.12 8.04 7 11.85 14.65 11.64 7 15-92 19-59 15.54 6 8.21 10.21 8.10 6 11.92 14-74 11.70 6 16.00 19.68 15.62 5 8.29 10.30 8.17 5 12.00 14.84 11.78 5 16.08 19.78 15-70 4 8.36 10.38 8.24 4 12.08 14-93 11.85 4 16.15 19.87 15-76 3 8.43 10.47 8.31 3 12.15 15.02 11.92 3 16.23 19.96 15-84 2 8.50 10.56 8.38 2 12.23 15.12 12.00 2 16.31 20.06 15-90 I 8-57 10.65 8-45 I 12.31 15.21 12.08 I 16.38 20.15 15-99 8.64 10-73 8.52 12.38 15-30 12.14 16.46 20.24 16.06 10.9859 8.71 10.82 8.58 0.9809 12.46 15-40 12.22 0-9759 16.54 20-33 16.13 8 8-79 10.91 8.66 8 12.54 15-49 12.30 8 16.62 20-43 16. 21 7 8.86 11.00 8.73 7 12.62 15-58 12.37 7 16.69 20.52 16.28 6 8-93 11.08 8.80 6 12.69 15.68 12.44 6 16.77 20.61 16.35 5 9.00 II. 17 8.87 5 12.77 15-77 12.51 5 16.85 20.71 16.43 4 9.07 11.26 8-93 4 12.85 15.86 12.59 4 16.92 20.80 16.50 3 9.14 11-35 9.00 3 12.92 15.96 12.66 3 1^7 . 00 20.89 16.57 2 9.21 11.44 9.07 2 13.00 16.05 12.74 2 17.08 20.99 16.65 I 9.29 11.52 9.14 I 13.08 16.15 12.81 I 17.17 21.09 16-74 9-36 II. 6i 9.22 13-15 16.24 12.89 17-25 21.19 16-81 0.9849 9-43 11.70 9.29 0.9799 13-23 16-33 12.96 0.9749 17-33 21.29 16.89 8 9-50 11.79 9-35 8 ■^i-i^ 16.43 13-03 8 17.42 21.39 16.97 7 9-57 11.87 9.42 7 13-38 16.52 13.10 7 17-50 21.49 17-05 6 9.64 11.96 9-49 6 13-46 16.61 13.18 6 17-58 21-59 17-13 5 9.71 12.05 9-56 5 13-54 16.70 13.26 5 17.67 21.69 17.20 4 9-79 12.13 9.64 4 13.62 16.80 T^3-2i 4 17-75 21.79 17.29 3 9.86 12.22 9.71 3 13.69 16.89 13-40 3 17-83 21.89 17-37 2 9-93 12.31 9-77 2 13-77 16.98 13-48 2 17.92 21.99 17.46 I 10.00 12.40 9.84 I 13-85 17.08 13-56 1 18.00 22.09 17-54 10.03 12.49 9.92 13.92 17-17 13-63 18.08 22.18 17.61 0.9839 10.15 12.58 9-99 0.9789 14.00 17.26 13-71 0.9739 18.15 22.27 17.68 8 10.23 12.68 10.06 8 14.09 17-37 13-79 8 18.23 22.36 17-76 7 10.31 12.77 10.13 7 14.18 17.48 13.88 7 18.31 22.46 17.82 6 10.38 12.87 10.20 6 14.27 17-59 13-96 6 18.38 22.55 17.90 5 10-46 12.96 10.28 5 14.36 17.70 14.04 5 18.46 22.64 17-97 410.54 13-05 10.36 4 14-45 17.81 14-13 4 18.54 22.73 18.05 3 10.62 13-15 10.44 3 14-55 17.92 14-23 3 18.62 22.82 18.13 2 10.69 13-24 10.51 2 14.64 18.03 14-32 2 18.69 22.92 18.19 I 10.77 13-34 10.59 I 14-73 18.14 14-39 1 18.77 23.01 18.27 c 10.85 13-43 10.67 14.82 18.25 14.48 18.85 21.10 18.34 JLCOHOUC BEVERAGES. 663 SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con/mwed)- Abs alute Alcohol. Absolute Alcohol. Abso lute Alcohol. Spec. Spe c. Spec. Grav. at Per Cent Per ^ ^""^ Cent ^^^"^^ to V. Per Cent Per Cent Grams Grav. at Per Cent Per Cent Grams 15.0'" C. bv by Vol- P'^"^ '5.6° C. by by Vol- per 15.6° C. by by Vol- per Weight ume. '°°''''- Weight ume. 100 cc. Weight ume. 100 cc. 0.9729 18.92 23.19 18.41 0.96 79 22.92 27-95 22.18 0.9629 26.60 32-27 25.61 8 19.00 23.18 18.48 8 23-00 28.04 22.26 8 26.67 32-34 25.67 7 19.08 23.38 18.56 7 23.08 28.13 22-33 7 26-73 32-42 25-73 6 19.17 23.48 18.65 6 23-15 28.22 22.40 6 26.80 32-50 25-79 5 19-25 23-58 18.73 5 23-23 28. 31 22.47 5 26.87 32-58 25-85 4 19-33 23.68 18.80 4 23-31 28.41 22.54 4 26.93 32-65 25-91 3 19.42 23.78 18.88 3 23-38 28.50 22.61 3 27.00 32-73 25.98 2 19-50 23-88 18.95 2 23-46 28.59 22.69 2 27-07 32.81 26.04 I 19-58 23.98 19.03 I 23-54 28.68 22.76 I 27.14 32.90 26.10 19.67 24.08 19.12 ° 23-62 28.77 22.83 27.21 32.98 26.17 0.9719 19-75 24.18 19.19 0.9^ 69 23.69 28.86 22.90 0.9619 27.29 33-06 26.25 8 19.83 24.28 19.27 8 23-77 28.95 22.97 8 27.36 33-15 26.31 7 19.92 24-38 19-36 7 23-85 29.04 23-05 7 27-43 33-23 26.37 6 20.00 24.48 19.44 6 23.92 29-13 23.11 6 27.50 Zo-Z"^ 26.43 5 20.08 24.58 19-51 5 24.00 29.22 23-19 5 27-57 33-39 26.51 4 20.17 24.68 19-59 4 24.08 29-31 23-27 4 27-64 33-48 26.57 3 20.25 24-78 19.66 3 24-15 29.40 23-33 3 27.71 33-56 26.64 2 20.33 24.88 19-74 2 24-23 29.49 23-40 2 27.79 33-64 26.71 1 20.42 24.98 19.83 I 24-31 29.58 23.48 I 27. 86 33-73 26.78 20.50 25-07 19.90 24-38 29-67 23-55 27-93 33-81 26.84 0.9709 20.58 25-17 19.98 o.gt ^59 24.46 29-76 23-62 0.9609 28.00 33-89 26.90 8 20.67 25-27 20.07 8 24-54 29.86 23-70 8 28.06 33-97 26.96 7 20.75 25-37 20.14 7 24.62 29-95 23-77 7 28.12 34-04 27.01 6 20.83 25-47 20.22 6 24-69 30.04 23-84. 6 28.19 34-11 27-07 5 20.92 25-57 20.30 5 24-77 30-13 23-91 5 28.25 34.18 27-13 4 21. OG 25-67 20-33 4 24.85 30.22 23-99 4 28.31 34-25 27.18 3 21.08 25-76 20.46 3 24-92 30-31 24-05 3 28.37 34-33 27.24 2 21.15 25.86 20.52 2 25-00 30.40 24.12 2 28.44 34-40 27-31 I 21.23 25-95 20.59 I 25-07 30.48 24-19 1 28-50 34-47 27.36 21.31 26.04 20.67 25.14 30-57 24-26 28.56 34-54 27.42 0.9699 21.38 26.13 20.73 o.gt )49 25.21 30.65 24-32 0-9599 28.62 34-61 27-47 8 21.46 26.22 20.81 8 25.29 30-73 24-39 8 28.69 34-69 27-53 7 21.54 26.31 20.89 7 25-36 30-82 24-46 7 28-75 34.76 27-59 6 21.62 26.40 20.96 6 25-43 30-90 24-53 6 28.81 34-83 27-64 5 21.69 26.49 21.03 5 25-50 30.98 24-59 5 28.87 34.90 27.70 4 21.77 26.58 21.11 4 25-57 31-07 24-66 4 28.94 34-97 27.76 3 21.85 26.67 21.18 3 25.64 3'^-''?> 24.72 3 29.00 35-05 27.82 2 21.92 26.77 21.25 2 25-71 31-23 24.79 2 29.07 35-12 27.89 I 22.00 26.86 21.33 I 25-79 3^-32 24.86 I 29.13 35-20 27-95 22.08 26.95 21.40 25-86 31-40 24.93 29.20 35-28 28.00 0.9689 22.15 27.04 21.47 o.gt 39 25-93 31.48 24.99 0.9589 29-27 35-35 28.07 8 22.23 27-13 21.54 8 26.00 31-57 25.06 8 29-33 35-43 28.12 7 22.31 27.22 21.61 7 26.07 31-65 25.12 7 29.40 35-51 28.18 ^ 22.38 27-31 21.68 6 26.13 31-72 25-18 6 29-47 35-58 28.24 5 22.46 27.40 21.76 5 26.20 31.80 25-23 5 29-53 35-66 28.30 4 22.54 27.49 21.83 4 26-27 31.88 25-30 4 29-60 35-74 28.36 3 22.62 27-59 21.90 3 26-33 31.96 25-36 3 29-67 35-81 28.43 2 22.69 27.68 21.96 2 26-40 32-03 25-43 2 29.73 35-89 28.48 I 22.77 27.77 22.01 1 26.47 32.11 25-49 1 29.80 35-97 28.54 22.85 27.86 22.12 26.53 32.19 25-55 29.87 36.04 28.61 664 FOOD INSPECTION yIND ANALYSIS. SPECIFIC GRAVITY AND PERCENTAGE OF ALCOB.O'L— {Continued). Absolute Alcohol. Absolute Alcohol. Absolute Alcohol. Spec. Spec. Spec. Grav. at Per Per Grams Grav. at Per Per Grams Grav. at Per Per Grams- 15-6° C. Cent by Cent by V.jl- per 100 cc. 15.6° C. Cent bv Cent by Vol- per 100 cc. 15.6° C. Cent by Cent by Vol- per 100 cc. Weight 29-93 ume. Weight ume. Weight ume. 0.9579 36.12 28.67 0.9529 32-94 39-54 31-38 0.9479 35-55 42.45 33 -7^ 8 30.00 36.20 28-73 8 33-00 39.61 31-43 8 35-60 42-51 33-75 7 30.06 36.26 28.78 7 33-06 39-68 31-48 7 35-65 42.56 33-79 6 30.11 36-32 28.82 6 33-12 39-74 31-53 6 35-70 42.62 33-83' 5 30-17 36-39 28.88 5 Z3-^^ 39.81 31-59 5 35-75 42.67 33-88 4 30.22 36-45 28.92 4 33-24 39-87 31-63 4 35-80 42-73 33-93- 3 30.28 36-51 28.98 3 33-29 39-94 31.69 3 35-85 42.78 33-97 2 i°-i5 36-57 29-03 2 33-35 40.01 31-74 2 35-90 42.84 34-01 1 30-39 36-64 29.08 I 33-41 40.07 ^1.80 I 35-95 42.89 34-05 30.44 36.70 20-13 33-47 40.14 31.86 36-00 42.95 34-09- 0.9569 30-50 36-76 29.18 0.9519 33-53 40.20 31-91 0.9469 36.06 43-01 34-14- 8 30.56 36-83 29-23 8 33-59 40.27 31-96 8 36.11 43-07 34-09- 7 30.61 36.89 29-27 7 33-65 40-34 32.01 7 36-17 43-13 34-24 6 30.67 36-95 29-33 6 33-71 40.40 32-07 6 36-22 43-19 34.28. 5 30-72 37.02 29.38 5 33-76 40-47 32.12 5 ^6.28 43-26 34-34 4 30. 78 37-08 29-43 4 33-8^ 40-53 32-17 4 36-33 43-32 34-38- 3 30.83 37-14 29.48 3 33-88 40.60 32.22 3 36-39 43-38 34-44- 2 30.89 37-20 29-53 2 33-94 40.67 32-27 2 36.44 43-44 34- 48' 1 30-94 37-27 29-58 I 34-00 40-74 32-32 I 36-50 43-50 34-54- 31.00 37-34 29.63 34-05 40.79 32-37 36-56 43-56 34-58 0.9559 31.06 37-41 29.69 0.9509 34-10 .40.84 32.41 0.9459 36.61 43-63 34-63. 8 31.12 37-48 29-74 8 34-14 40.90 32-45 8 36-67 43-69 34-69 7 31-19 37-55 29.81 7 34-19 40-95 32-49 7 36-72 43-75 34-73 6 31-25 37.62 29.86 6 34.24 41.00 32-54 6 36-78 43.81 34-79 5 3-!--i^ 37-69 29.91 5 34-29 41-05 32-59 5 36-83 43-87 34 -8j 4 31-37 37-76 29-97 4 34-33 41. II 32.63 4 36.89 43-93 34.88 3 31-44 37-83 30-03 3 34.38 41.16 32.67 3 36-94 44-00 34-92 2 31-50 37-90 30.09 2 34-43 41.21 32-71 2 37-00 44.06 34-96 I 31-56 37-97 30.14 I 34-48 41.26 32-75 I 37-06 44.12 35-02 31.62 38-04 30.20 34-52 41-32 32-79 37-" 44.18 35-or 0.9.-549 31.69 38.11 30.26 0.9499 34-57 41-37 32-84 0.9449 37-17 44-24 35-12- 8 31-75 38.18 30-31 8 34.62 41.42 32.88 8 37-22 44-30 35-10- 7 31.81 38-25 30-36 7 34-67 41.48 32.92 7 37-28 44-36 35-21 6 31-87 38-33 30.42 6 34.71 41-53 32.96 6 37-33 44-43 35-2^ 5 31-94 38-40 30-48 5 34.76 41.58 33- 00 5 37-39 44.49 35-31 4 32.00 38-4; 30-53 4 34.81 41-63 33-04 4 37-44 44-55 35-35 3 32.06 38-53 30-59 3 34.86 41-69 33-09 3 37-50 44.61 35-41 2 32.12 ^o-^S 30.64 2 34.90 4.1 - 74 3i-''2> 2 37-56 44-67 35-46' I 32.19 38-68 30.71 I 34.95 41.79 33-17 I 37.61 44-73 35-51 32-25 38-75 30-77 35-00 41-84 33-21 37-67 44-79 35-56 e.9539 32-31 38-82 :io.8i 0.9489 35-05 41.90 32.26 0.9439 37-73 44-86 35-60 8 32-37 38.89 30.87 8 35-10 41-95 33-30 8 37-78 44-92 35-65 7 32-44 38-96 30-93 7 35-15 42.01 33-34 7 37-83 44.98 35-70 6 32-50 39-04 30-99 6 35 -20 42.06 33-39 6 37-89 45-04 35-75 5 32-56 39-11 31-05 5 35-25 42.12 33-43 5 37-49 45-10 35-80 4 32.62 39.18 31.10 4 35-30 42.17 33-48 4 38.00 45.16 35-85 3 32.69 39-25 31-15 3 35-35 42-23 33-53 3 38.06 45-22 35-90 2 32-75 39-32 31.20 2 35-40 42.29 33-57 2 38.11 45.28 35-95 1 32.81 39-40 31.26 I 35-45 42.34 33-61 I 38-17 45 = 34 36.00 32.87 39-47 31-32 35-50 42.40 33-65 38.22 45-41 36-04 ALCOHOLIC BEyERAGES. 665 SPECIFIC GRAVITY AND PERCENTAGE OF M.COU.Ol.— {Continued). Spec. Absolute Alcohol. Spec. Absolute Alcohol. Absolute Alcohol. Spec. ^ mm Grav. at tS.6° C. Per Cent Per Cent Grams Grav. at iS.6°C. Per Cent Per Cent Grams Grav. at Per Cent Per Cent Grams bv by Vol- per by by Vol- per 15.6° C. by by Vol- per Weight ume. 100 cc. Weight ume. 100 cc. Weight ume. 100 cc. 0.9429 38.28 45.47 36.08 0.9379 40.85 48.26 38.31 0.9329 43-29 50-87 40.38 8 38-33 45-53 36-13 8 40.90 48.32 38-35 8 43 3,2> 50.92 40.42 7 38-39 45-59 36.18 7 40.95 48.37 38-39 7 43 39 50-97 40.46 6 38-44 45-65 36-23 6 41.00 48-43 38-44 6 43 43 51.02 40.50 5 38-50 45-71 36-28 5 41.05 48.48 38-48 5 43 48 51-07 40.54 4 38.56 45-77 36-33 4 41.10 48.54 38-52 4 43 52 51.12 40.58 3 38.61 45-83 36-38 3 41-15 48-59 38-58 3 43 57 51.17 40.62 2 38-67 45-89 36-43 2 41.20 48.64 38-62 2 43 62 51.22 40.66 I 38.72 45-95 36-48 I 41.25 48.70 38.66 I 43 67 51.27 40.70 38-78 46.02 36.53 41-30 48-75 38-70 43 71 51.32 40.74 0.9419 38-83 46.08 36-57 0.9369 41-35 48.80 38-74 0.9319 43 76 51-38 40.78 8 38-89 46.14 36.62 8 41.40 48.86 38-78 8 43 81 51-43 40.81 7 38-. 94 46.20 36-67 7 41.45 48.91 38.82 < 7 43 86 51-48 40.85 6 39.00 46.26 36-72 6 41-50 48.97 38.87 6 43 90 51-53 40.89 5 39-05 46.32 36-76 5 41-55 49-02 38.91 5 43 95 51-58 40-93 4 39.10 46.37 36.80 4 41.60 49.07 38-95 4 44 00 51.65 40.97 3 39-15 46.42 36-85 3 41.65 49-13 38-99 3 44 05 51.68 41.01 2 39.20 46.48 36.89 2 41.70 49.18 39-04 2 44 09 51-72 41.05 I 39-25 46.53 36-94 I 41-75 49-23 39-08 I 44 14 51-77 41.09 39.30 46.59 36-98 41.80 49.29 39-13 44 18 51.82 41 13 9409 39.35 46.64 37.02 0-9359 41.85 49.34 39-17 0.9309 44 23 51-87 41-17 8 39.40 46-70 37.07 ,'8 41.90 49 40 39-21 8 44 27 51-9^ 41.20 7 39-45 46-75 37-11 ' 7 41-95 49-45 39-25 7 44 32 51.96 41.24 6 39-50 46.80 37-15 6 42.00 49 50 39-30 6 44 36 52-01 41.28 5 39-55 46.86 37.19 5 42.05 49-55 39-34 5 44 41 52.06 41-31 4 39.60 46.91 37-23 4 42.10 49.61 39-38 4 44 46 52.10 41-35 3 39-65 46.97 37.27 3 42.14 49.66 39-42 3 44 50 52-15 41.49 2 39.70 47.02 37.32 2 42.19 49-71 39-46 2 44 55 52.20 41.43 I 39.75 47-08 37-36 I 42.24 49-76 39-50 I 44 59 52-25 41-47 39.80 47.13 37-41 42.29 49.81 39-54 44 64 52.29 41.51 0.9399 39-85 47.18 37-45 0-9349 42.33 49.86 39-58 0.9299 44 68 52-34 41-55 8 39.90 47-24 37-49 8 42.38 49-91 39.62 8 44 73 52-39 41-59 7 39-95 47-29 37-53 7 42.43 49.96 39-66 7 44 77 52-44 41-63 6 40.00 47-35 37-58 6 42.48 50-01 39-70 6 44 82 52.48 41.67 5 40-05 47-40 37.62 5 42-52 50.06 39-74 5 44 86 52-53 41.70 4 40.10 47.45 37-67 4 42-57 50.11 39-78 4 44 91 52-58 41.74 3 40.15 47-51 37-71 3 42.62 50.16 39-82 3 44 96 52-63 41.77 2 40.20 47-56 37-75 2 42.67 50.21 39-86 2 45 00 52-68 41.81 I 40.25 47.62 37.80 I 42 . 71 50.26 39-90 I 45 05 52-72 41.85 40.30 47.67 37-84 42.76 50.31 39-94 45.09 52-77 41.89 0.9389 40.35 47.72 37.88 0-9339 42.81 50-37 39-98 0.9289 45-14 52.82 41.93 8 40.40 47.78 37-92 8 42.86 50.42 40.02 8 45.18 52-87 41-97 7 40.45 47-83 37-96 7 42.90 50-47 40.06 7 45 23 52-91 42.00 6 40.50 47-89 38.00 6 42.95 50-52 40.10 6 45 27 52.96 42-04 5 40.55 47-94 38-05 5 43.00 50-57 40-14 5 45 32 53-01 42.08 4 40.60 47-99 38.09 4 43-05 50.62 40.18 4 45 36 53-06 42.12 3 40.65 48.05 38.13 3 43.10 50.67 40.22 3 45 41 53-10 42.16 2 40.70 48.10 38.18 2 43-13 50.72 40.26 2 45 46 53-15 42.19 I 40-75 48.16 38.22 I 43.19 50.77 40.30 I 45 50 53-20 42.23 40.80 48.21 38-27 43.24 50.82 40.34 45-55 53-24 42.27 666 FOOD INSPECTION AND ANALYSIS. SPECIFIC. GRAVITY AND PERCENTAGE OF k'LCO^OT^— {Continued). Spec. Grav. Absolu1,e Alcohdl. Spec. Grav. Absolute Alcohol. Spec. Grav. Absolute Alcohol. at Per Per at Per Per at Per Per 15.0" C. Cent Cent 15.6° C. Cent Cent 15.6° C. Cent Cent by by Vol- by by Vol- by by Vol- Weight. ume. Weight. ume. Weight. ume. 0,9279 45-59 53-29 0.9229 47.86 55-65 0.9179 50-13 57-97 8 45-64 53-34 8 47.91 55-69 8 50-17 s8.oi 7 45.68 53-39 7 47.96 55-74 7 50-22 58.06 6 45-73 53-43 6 48.00 55-79 6 50.26 58.10 5 45-77 53-48 5 48. 05 55-83 5 50-30 58.14 4 45.82 53-53 4 48.09 55-88 4 50-35 58.19 3 45.86 53-58 3 48.14 55-93 3 50-39 58.23 2 45.91 53.62 2 48.18 55-97 2 50.4.3 S8.28 I 45-96 53-67 I 48.23 56.02 1 50.48 58.32 46.00 53-72 48.27 56.07 50.52 5S.36 0,9269 46.05 53-77 0.9219 48.32 56.11 0.9169 50.57 58.41 8 46.09 53-81 8 48.36 56.16 8 50.61 58.45 7 46.14 53-86 7 48.41 56.21 7 50-65 58.50- 6 46.18 53-91 6 48.46 56.25 6 50.70 58.54 5 46.23 53-95 5 48.50 56.30 5 50.74 58.58 4 46.27 54.00 4 48.55 56.35 4 50.78 58.63 3 46.32 54-05 3 48-59 56-40 3 50.83 58.67 2 46.36 54-10 2 48.64 56-44 2 50.87 58.72 I 46.41 54-14 I 48.68 56-49 1 50-91 58.76 46.46 54-19 48.73 56-54 50.96 58.80 0.9259 46.50 54-24 0.9209 48.77 56-58 0-9159 51.00 58.85 8 46.55 54-29 8 48.82 56.63 8 51.04 58.89. 7 46.59 54-33 7 48.86 56.68 ■ 7 51.08 58-93 6 46.64 54-38 6 48. QI 56.72 6 51.13 58-97 5 46.68 54-43 5 48.96 56-77 5 51.17 59.01 4 46.73 54-47 4 49.00 56.82 4 51.21 59-05 3 46.77 54-52 3 49.04 56.86 3 51-25 59.09 2 46.82 54-57 2 49.08 56.90 2 51-29 59.14 I 46.86 54.62 I 49.12 56-94 I 5-33 59.18 46.91 54.66 49.16 56.98 51-38 59.22 0.9249 46.96 54.71 0.9199 49-20 57.02 0.9149 51-42 59.26 8 47- 00 54.76 Proof 8 49-24 57-06 8 51.46 59-30 7 47-05 54.80 7 49-29 57 -10 7 51-50 59-34 6 47-09 54.85 6 49-34 57-15 6 51-54 59-39 5 47-14 54.90 5 49-39 57.20 5 51-58 59-43 4 47-18 54.95 4 49-44 57-25 4 51-63 59-47 3 47-23 54-99 3 49-49 57-30 3 51-67 59.51 2 47-27 55-04 2 49-54 57-35 2 51-71 59-55 I 47-32 55-09 I 49-59 57-40 I 51-75 59-59 47-36 55-13 49-64 57-45 51-79 59-63 0-9239 47-41 55-18 0.9189 49.68 57-49 0.9139 51-8,3 59.68 8 47-46 55-23 8 49-73 57-54 8 51.88 59-72 7 47-50 55-27 7 49-77 57-59 7 51-92 59-76 6 47-55 55-32 6 49-82 57-64 6 51.96 59-80 5 47-59 55-37 5 49.86 57.69 5 52-00 59.84 4 47-64 55-41 4 49-91 57-74 4 52-05 59-89 3 47.68 55-46 .3 49-95 57-79 3 52.09 59-93 2 47-73 55-5t 2 50.00 57-84 2 52-14 59-98 I 47-77 55-55 I 50.04 57-88 I 52.18 60.02 47-82 55-60 50.09 58-92 52-23 60.07 ALCOHOLIC BEVERAGES. 667- SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Com/wwcJ). Absolute Alcohol. Spec. Grav. at 15.6° C. Per Cent by Weight. 0.91129 52- 8 52- 7 .52. 6 52- 5 52- 4 52- 3 52. 2 52. I 52- 52. 0.91 19 52. 8 52- 7 52- 6 52- 5 52- 4 52- 3 53- 2 53- I 53- 53. C.9109 53- 8 53- 7 53- 6 53- 5 53- 4 53- 3 53- 2 53- I 53- 53- 0.9099 53- 8 53- 7 53- 6 53- 5 53- 4 53- 3 53- 2 53- I 53- 54- 0.9089 54- 8 54- 7 54- 6 54- 5 54- 4 54- 3 54- 2 54- I 54- 54- 27 32 ■36 .41 -45 ■50 •55 -59 .64 .68 73 77 82 86 91 95 GO 04 09 13 17 22 .26 ■30 •35 -39 -43 .48 ■52 ■57 .61 ■65 .70 •74 .78 -83 .87 .91 .96 .10 .14 .19 .24 .29 ■33 .38 -43 .48 Per Cent by Vol- ume. 60.12 60.16 60.21 60.25 60.30 60.34 60.39 60.44 60.47 60.52 60.56 60.61 60.65 60.70 60.74 60.79 60.85 60.89 60.93 60.97 6r.02 61.06 61.10 61.15 61.19 61.23 61.28 61.32 61.36 61.40 61.45 61.49 61-53 61.58 61.62 61.66 61.71 61-75 61.79 61.84 61. 88 61.93 61.98 62.03 62.07 62. 12 62.17 62.22 62.26 62.31 Absolute Alcohol. Spec. Grav. at 15.6° C. .9079 8 .9069 8 7 6 5 4 3 2 0.9659 8 7 6 5 4 3 0.9049 8 7 6 5 4 3 0.9039 8 7 6 5 4 3 Per Cent by Weight. 54-52 54-57 54-62 54-67 54-71 54-76 54-81 54-86 54-90 54-95 55-00 55-05 55-09 55-14 55-18 55-23 55-27 55-32 55-36 55-41 55-45 55-50 55-55 55-59 55-64 55-68 55-73 55-77 55-82 55-86 55-91 55-95 56.00 56.05 56.09 56.14 56.18 56.23 56-27 56-32 56-36 56.41 56-45 56-30 56-55 56-59 56.64 56.68 56.73 56-77 Per Cent by Vol- ume. 62.36 62.41 62.45 62.50 62.55 62.60 62.65 62.69 62.74 62.79 62.84 62.88 62.93 62.97 63-02 63.06 63.11 63-15 63.20 63.24 63.28 63-33 63-37 63-42 63.46 63-51 63-55 63.60 63.64 63.69 63-73 63.78 63.82 63-87 63.91 63-96 64.00 64-05 64.09 64.14 64.18 64.22 64.27 64.31 64.36 64.40 64-45 64-49 64-54 64-58 Spec. Grav. at 15.6° C. 0.9029 0.9019 0.9009 0.8999 Absolute Alcohol. Per Cent by Weight. Per Cent by Vol- ume. 64.63 64.67 64-71 64.76 64.80 64.85 64.89 64-93 64.97 65.01 65-05 65.09 65-13 65-17 65.21 65-25 65.29 65-33 65-37 65.41 65-45 65-49- 65-53 65-57 65.61 65-65 65-69 65-73 65-77 65-81 65-85 65.90 65-94 65-99 66.03 66.07 66.12 66.16 66.21 66.25 66.29 66.34 66.38 66.43 66.47 66.51 66.56 66.60 66.65 66.09 663 f-OOD INSPECTION AND ANALYSIS. SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL — {Continued). Absolute Alcohol. Absolute Alcohol. Absolute Alcohol. Spec. Spec. Spec. Grav. at Per Per Grav. at Per Per Grav. at Per Per 15.6° C. Cent Cent 15.6° C. Cent Cent 15.6° C. Cent Cent by by Vol- by by Vol- by by Vol- Weight. ume. Weight. ume. Weight. ume. 0.8979 59.00 66.74 0.8929 61.13 68.76 0.8879 63.30 70.81 8 59-04 66.78 8 61.17 68.80 8 63-35 70.85 7 59-09 66.82 7 61.21 68.83 7 63-39 70.89 6 59-13 66.86 6 61.25 68.87 6 63.43 70=93 5 59-17 66.90 5 61.29 68.91 5 63-48 70-97 4 59-22 66.94 4 61.33 68.95 4 63-52 71.01 3 59.26 66.99 3 61.38 68.99 3 63-57 71-05 2 59-30 67.03 2 61.42 69-03 2 63.61 71.09 I 59-35 67.07 I 61.46 69.07 I 63-65 71-13 59-39 67.11 61.50 69. II 63-70 71.17 0.8969 59-43 67-15 0.8919 61.54 69.15 0.8869 63-74 71.22 8 59-48 67.19 8 61. s8 69.19 8 63-78 71.26 7 59-52 67.24 7 61.63 69.22 7 63-83 71-30 6 59-57 67.28 6 61.67 69.26 6 63.87 71-34 5 59-61 67.32 5 61.71 69.30 5 63.91 71-38 4 59-65 67-36 4 61-75 69-34 4 63.96 71.42 3 59-70 67.40 3 61.79 69-38 3 64.00 71.46 2 59-74 67.44 2 61. 8s 69.42 2 64.04 71-50 I 59-78 67.49 I 61.88 69.46 I 64.09 71-54 59-83 67-53 61.92 69.50 64-13 71-58 0.8959 59-87 67-57 0.8909 61.96 69-54 0.8859 64.17 71.62 8 59-91 67.61 8 62.00 69.58 8 64.22 71.66 7 59-96 67.65 7 62.05 69.62 7 64.26 71.70 6 60.00 67.69 6 62.09 69.66 6 64.30 71-74 5 60.04 67-73 5 62.14 69.71 5 64-35 71.78 4 60.08 67.77 ! 4 62.18 69-75 4 64-39 71.82 3 60.13 67.81 3 62.23 69.79 3 64.43 71.86 2 60.17 67.85 2 62.27 69.84 2 64.48 71.90 I 60.21 67.89 1 I 62.32 69.88 I 64.52 71.94 60.26 67-93 ' 62.36 69.92 64.57 71.98 0.8040 60.29 67.97 0.8899 62.41 69.96 0.8849 64.61 72.02 8 60.33 68.01 8 62.45 70.01 8 64.65 72.06 7 60.38 68.05 1 7 62.50 70-05 7 64.70 72.10 6 60.42 68.09 1 6 62.55 70.09 6 64.74 72.14 5 60.46 68.13 5 62.59 70.14 5 64.78 72.18 4 60.50 68.17 4 62.64 70.18 4 64.83 72.22 3 60.54 68.21 3 62.68 70.22 3 64.87 72.26 2 60.58 68.25 2 62.73 70.27 2 64.91 72-30 I 60.63 68 29 I 62.77 70.31 I 64.96 72-34 60.67 68.33 62.82 70-35 65.00 72-38 0.8939 60.71 68.36 0.8889 62.86 70.40 0.8839 65.04 72.42 8 60.76 68.40 8 62.91 70.44 8 65.08 72.46 7 60.79 68.44 7 62.95 70.48 7 65.13 72.50 6 60.83 68.48 6 63.00 70.52 6 65.17 72.54 5 60.88 68.52 5 63.04 70.57 5 65.21 72.58 4 60.92 68.56 4 63.09 70.61 4 65-25 72.61 3 60.96 68.60 3 63-13 70.65 3 65.29 72.65 2 61.00 68.64 2 63-17 70.69 2 65-33 72.69 I 61.04 68.68 I 63.22 70.73 I 65-38 72.73 61.08 68.72 63.26 70.77 65.42 72. 7J ALCOHOLIC BBVERAGES. 669 SPECIFIC GRAVITY AND PERCENTAGE OF K'LCOU.Ol.— {Continued). Absolute Alcohol. Absolute Alcohol. Spec. Absolute Alcohol. Spec. Spec. Grav. Per Per Grav. Per Per Grav. Per Per at J TS.6"'C. 1 Cent Cent at 15.6° C. Cent Cent at 15.6° C. Cent Cent by by Vol- by by Vol- by by Vol- Weight. ume. Weight. ume. Weight. ume. -0.8829 65.46 72.80 0.8779 67.58 74-74 0.8729 69.67 76.61 8 65-50 72.84 8 67.63 74-78 8 69.71 76.65 7 65-54 72.88 7 67.67 74-82 7 69.75 76.68 6 65-58 72.92 6 67.71 74-86 6 69.79 76.72 5 65.63 72.96 5 67-75 74-89 5 69.83 76.76 4 65-67 72.99 4 67.79 74-93 4 69.88 76.80 3 65-71 73-03 3 67.83 74-97 3 69.92 76.83 2 65-75 73-07 2 67.88 75-01 2 69.96 76.87 I 65-79 73-11 I 67.92 75-04 I 70.00 76.91 65-83 73-15 67.96 75-08 70.04 76.94 .0.8819 65.88 73-19 0.8769 68.00 75-12 0.8719 70.08 76.98 8 65.92 73.22 8 68.04 75-16 8 70.12 77.01 7 ■65-96 73.26 7 68.08 75-19 7 70- 16 77-05 6 66.00 73-30 6 68.13 75-23 6 70.20 77.08 5 66.04 73-34 5 68.17 75-27 5 70.24 77.12 4 66.09 73-38 4 68.21 75-30 4 70.28 77-15 3 66.13 73-42 3 68.25 75-34 3 70-32 77.19 2 66.17 73-46 /'2 68.29 75-38 2 70.36 77.22 I 66.22 73-50 I 68-33 75-42 I 70.40 77-25 66.26 73-54 68.38 75-45 70.44 77.29 ■0.8809 66.30 73-57 0.8759 68.42 75-49 0.8709 70.48 77-32 8 66.35 73-61 8 68.46 75-53 8 70-52 77-36 7 66.39 73-65 7 68.50 75-57 7 70.56 77-39 6 66.43 73-69 6 68.54 75.60 6 70.60 77-43 5 66.48 73-73 5 68.58 75-64 5 70.64 77-46 4 66.52 73-77 4 68.63 75.68 4 70.68 77-50 3 66.57 73-81 3 68.67 75-72 3 70.72 77-53 2 66.61 73-85 2 68.71 75-75 2 70.76 77-57 I 66.65 73-89 I 68.75 75-79 I 70.80 77.60 66.70 73-93 68.79 75-83 70.84 77.64 0.8799 66.74 73-97 0.8749 68.83 75-87 0.8699 70.88 77-67 8 66.78 74.01 8 68.88 75-90 8 70.92 77.71 7 66.83 74-05 7 68.92 75-94 7 70.96 77-74 6 66.87 74.09 6 68.96 75-98 6 71.00 77-78 5 66.91 74-13 5 69.00 76.01 5 71.04 77-82 4 66.96 74-17 4 69.04 76.05 4 71.08 77-85 3 67.00 74.22 3 69.08 76.09 3 71-13 77-89 2 67.04 74-25 2 69.13 76.13 2 71.17 77-93 I 67.08 74.29 I 69.17 76.16 I 71.21 77-96 67.13 74-33 69.21 76.20 71-25 78.00 -0.8789 67.17 74-37 0-8739 69-25 76.24 0.8689 71.29 78.04 8 67.21 74-40 8 69.29 76-27 8 71-33 78-07 7 67.25 74-44 7 69-33 76-31 7 71-38 78.11 6 67.29 74.48 6 69-38 76.35 6 71.42 78.14 5 67-33 74-52 5 69.42 76-39 5 71.46 78.18 4 67-38 74-55 4 69.46 76-42 4 71-50 78.22 3 67.42 74-59 3 69.50 76-46 3 71-54 78.25 2 67.46 74-63 2 69-54 76.50 71-58 78.29 I 67.50 74-67 I 69-58 76.53 I 71-63 78-33 67-54 74-70 69-63 76.57 71.67 78.^6 670 FOOD INSPECTION AND ANALYSIS. SPECIFIC GRAVITY AND PERCENTAGE OF KLCOHOI.— {Continued). Absolute Alcohol. Absolute Alcohol. Absolute Alcohol. _ Spec. Spec. spec. Grav. Per Per Grav. at Per Per Grav. at Per Per at 15.6° c. Cent Cent 15.6° C. Cent Cent 15.6° C. Cent Cent by by Vol- by by Vol- by by Vol- Weight. ume. Weight. ume. Weight. ume. 0.8679 71.71 78.40 0.8629 73-83 80.26 0.8579 76.08 82.23 8 71-75 78.44 8 73.88 80.30 8 76.13 82.26 7 71.79 78.47 7 73-92 80-33 7 76.17 82.30 6 71-83 78.51 6 73-96 80-37 6 76.21 82.33 5 71.88 78-55 5 74-00 80.40 5 76-25 82-37 4 71.92 78.58 4 74-05 80.44 4 76.29 82.40 3 71.96 78.62 3 74.09 80.48 3 76.33 82.44 2 72.00 78.66 2 74.14 80.52 2 76.38 82.47 I 72.04 78.70 I 74.18 80.56 I 76.42 82.51 72.09 78-73 74-23 80.60 76.46 82.54 0.8669 72-13 78-77 0.8619 74-27 80.64 0.8569 76-50 82.58 8 72.17 78.81 8 74-32 80.68 8 76.54 82.61 7 72.22 78.85 7 74-36 80.72 7 76-58 82.65 6 72.26 78.89 6 74-41 80.76 6 76.63 82.69 5 72.30 78-93 5 74-45 80.80 5 76.67 82.72 4 72-35 78.96 4 74-50 80.84 4 76.71 82.76 3 72-39 79.00 3 74-55 80.88 3 76.75 82.79 2 72-43 79.04 2 74-59 80.92 2 76.79 82.83 I 72-48 79.08 I 74.64 80.96 I 76-83 82.86 72.52 79.12 74.68 81 .00 76.88 82.90 0.8659 72-57 79.16 0.8609 74-73 81.04 0.8559 76.92 82.93 8 72.61 79.19 8 74-77 8i.o8 8 76.96 82.97 7 72.65 79-23 7 74-82 81.12 7 77.00 83.00 6 72.70 79.27 6 74.86 81.16 6 77.04 83-04 5 72.74 79-31 5 74.91 81.20 5 77.08 83-07 4 72.78 79-35 4 74-95 81.24 4 77-13 83-11 3 72.83 79-39 3 75.00 81.28 3 77.17 83.14 2 72.87 79.42 2 75-05 81.32 2 77-21 83.18 1 72.91 79.46 I 75-09 81-36 I 77-25 83-21 72.96 79-50 75-14 81.40 77-29 83.25 0.8649 73.00 79-54 0.8599 75-18 81.44 0.8549 77.33 83.28. 8 73-04 79-57 8 75-23 81.48 8 77-38 83-32 7 73.08 79.61 7 75-27 81.52 7 77-42 83-36 6 73-13 79-65 6 75-33 81.56 6 77-46 83-39 5 73-17 79.68 5 75-36 81.60 5 77-50 83-43 4 73-21 79.72 4 75-41 81.64 4 77-54 83.46. 3 73-25 79-75 3 75-45 81.68 3 77-58 83.50 2 73-29 79-79 2 75-50 81.72 2 77-63 83-53 I 73-33 79-83 I 75-55 81.76 I 77-67 83-57 73-38 79.86 75-59 81.80 77-71 83.60 0.8639 73-42 79-90 0.8589 75-64 81.84 0-8539 77-75 83.64 8 73-46 79-94 8 75.68 81.88 8 77-79 83-67 7 73-50 79-97 7 75-73 81.92 7 77-83 83-71 6 73-54 80.01 6 75-77 81.96 6 77-88 83-74 5 73-58 80.04 5 75-82 82.00 5 77-92 83.78 4 73-63 80.08 4 75-86 82.04 4 77-96 83.81 3 73-67 80.12 3 75-91 82.08 3 78.00 83.85 2 73-71 80.15 2 75-95 82.12 2 78.04 83.88. I 73-75 80.19 I 76.00 82.16 I 78.08 83.91 73-79 80.22 76.04 82.19 78.12 83-94 /fLCOHOLIC BEk'ERAGES. 6p SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOl.— {Continued). Absolute Alcohol. Spec. Absolute Alcohol. Spec. Absolute Alcohol. Spec. Grav. Per Per Grav. Per Per Grav. Per Per at 15.6° C. Cent Cent. at 15-6° C. Cent Cent at 15.6° C. Cent Cent by by Vol- by by Vol- bv by Vol- Weight. ume. Weight. ume. Weight. ume. 0.8529 78.16 83.98 0.8479 80.17 85-63 0.8429 82.19 87.27 8 78.20 84.01 8 80.21 85 .66 8 82.23 87-30 7 78.24 84.04 7 80.25 85 .70 7 82.27 87-34 6 78.28 84.08 6 80.29 85 •73 6 82.31 87-37 5 78.32 84.11 5 80.33 85 -77 5 82.35 87.40 4 78.36 84.14 4 80.38 85 .80 4 82.38 87-43 3 78.40 84.18 3 80.42 85 .84 3 82.42 87.46 2 78.44 84.21 2 80.46 85 -87 2 82.46 87.49 I 78.48 84.24 I 80.50 85 .90 I 82.50 87-52 78.52 84.27 80.54 85 ■94 82.54 87-55 0.8519 78.56 84.31 0.8469 80.58 85 97 1 0.8419 82.58 87.58 8 78.60 84-34 8 80.63 86 01 ' 8 82.62 87.61 7 • 78.64 84-37 7 80.67 86 04 1 7 82.65 87.64 6 78.68 84.41 6 80.71 86 08 i 6 82.69 87.67 5 78.72 84.44 5 80.75 86 II 1 5 82.73 87.70 4 78.76 84-47 4 80.79 86 15 4 82.77 87.73 3 78.80 84-51 3 80.83 86 18 3 82.81 87.76 2 78.84 84-54 2 80.88 86 22 2 82.85 87-79 I 78.88 84-57 / I 80.92 86 25 I 82.88 87.82 78.92 84.60 / ° o;'8459 80.96 86 28 82.92 87.85 0.8509 78.96 84.64 81.00 86 32 0.8409 82.96 87.88 8 79.00 84.67 8 81.04 86 35 8 83.00 87.91 7 79.04 84.70 7 81.08 86 38 7 83.04 87-94 6 70.08 84.74 6 81.12 86 42 6 83.08 87.97 5 79.12 84-77 5 81.16 86 45 5 83.12 88.00 4 79.16 84.80 4 81.20 86 48 4 83-15 88.03 3 79.20 84-83 3 81.24 86 51 3 83.19 88.06 2 79.24 84.87 2 81.28 86 54 2 83-23 88.09 I 79.28 84.90 I 81.32 86 58 I 83-27 88.13 79-32 84.93 81.36 86 61 1 83-31 88.16 C.8499 79-36 84.97 0.8449 81.40 86 64 0.8399 83-35 88.19 8 79.40 85.00 8 81.44 86 67 j 8 83-38 88.22 7 79-44 85-03 7 81.48 86 71 7 83.42 88.25 6 79.48 85.06 6 81.52 86 74 6 83.46 88.28 5 79-52 85.10 5 81.56 86 77 5 83-50 88.31 4 79.56 85-13 4 81.60 86 80 4 83-54 88.34 3 79.60 85-16 3 81.64 86 83 3 83-58 88.37 2 79.64 85.19 2 81.68 86 87 2 83.62 88.40 I 79.68 85.23 I 81.72 86 90 I 83-65 88.43 79.72 85.26 81.76 86 93 83.69 88.46 0.8489 79.76 85.29 0.8439 81.80 86 96 0.8389 83-73 88.49 8 79.80 85.33 8 81.84 86 99 8 83-77 88.52 7 79.84 85-36 7 81.88 87. 03 7 83.81 88.55 6 79-88 85-39 6 81.92 87- 06 6 83-85 88.58 5 79.92 85.42 5 81.96 87- 09 5 83.88 88.61 4 79.96 85.46 4 82.00 87- 12 4 83.92 88.64 3 80.00 85-49 3 82.04 87. 15 3 83.96 88.67 2 80.04 85-53 2 82.08 87. 18 2 84.00 88.70 I 80.08 85.56 I 82.12 87. 21 I 84. C4 88.73 80.13 85-59 82.15 87.24 84.08 88.76 672 FOOD INSPECTION ^ND /IN A LYSIS. SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Cow/mj^ei). Absolute Alcohol. Spec. Grav. 3.t Absolute Alcohol. 1 Absolute Alcohol. Spec. Grav. Per Per Per Per Grav. at Per Per at 15.6° C. Cent Cent T c (i° r Cent Cent 15.6° C. Cent Cent. bv by Vol- 1 5.U K^. by by Vol- bv by Vol- Weight. ume. Weight. ume. Weight. ume. 0.8379 84.12 88.79 0.8329 86.08 90-32. 0.8279 88.00 91.78 8 84.16 88.83 8 86.12 90-35 8 88.04 91.81 7 84.20 88.86 7 86.15 90.38 7 88.08 91.84 6 84.24 88.89 6 86.19 90.40 6 88.12 91.87 5 84.28 88.92 5 86.23 90-43 5 88.16 91.90 4 84.32 88.95 4 86.27 90.46 4 88.20 91-93 3 84.36 88.98 3 86.31 90.49 3 88.24 91.96 2 84.40 89.01 2 86.35 90.52 2 88.28 91.99 I 84-44 89.05 I 86.38 90-55 I 88.32 , 92.02 84.48 89.08 86.42 90.58 88.36 92-05 0.8369 84.52 89.11 0.8319 86.46 90.61 0.8269 88.40 92.08 8 84.56 89.14 8 86.50 90.64 8 88.44 92.12 7 84.60 89.17 7 86.54 90.67 7 88.48 92-15 6 84.64 89.20 6 86.58 90.70 1 6 88.52 , 92.18 5 84.68 89.24 5 86.62 90-73 5 88.56 92.21 4 84.72 89-27 4 86.65 90.76 4 88.60 92-24 3 84.76 89.30 3 86.69 90-79 3 88.64 92.27 2 84.80 89-33 2 86.73 90.82 2 88.68 92-30 I 84.84 89-36 I 86.77 90-85 I 88.72 92-33 84.88 89-39 86.81 90.88 88.76 92.36 0.8359 84.92 89.42 0.8309 86.85 90.90 0.8259 88.80 92-39 8 84.96 89.46 8 86.88 90-93 8 88.84 92.42 7 85.00 89-49 I 7 86.92 90.96 7 88.88 92-45 6 85.04 89 52 6 86.96 90.99 6 88.92 92.48 5 85.08 89-55 5 87.00 91.02 5 88.96 92-51 4 85.12 89.58 4 87.04 91.05 4 89.00 92-54 3 85-15 89.61 3 87.08 91.08 3 89.04 92-57 2 85.19 89.64 2 87.12 91. II 2 89.08 92.60 I 85-23 89.67 I 87-15 91.14 I 89.12 92.63 85-27 89.70 87.19 91.17 89.16 92.66 0.8349 85-31 89.72 0.8299 87-23 91.20 0.8249 89.19 92.68 8 85-35 89-75 8 87-27 91.23 8 89.23 92.71 7 85-38 89.78 7 87-31 91-25 7 89-27 92.74 6 85-42 89.81 6 87-35 91.28 6 89.31 92.77 5 85.46 89.84 5 87-38 91-31 5 89-35 92.80 4 85-50 89.87 4 87.42 91-34 4 89.38 92-83 3 85-54 89.90 3 87.46 91-37 3 89.42 92.86 2 85-58 89-93 2 87.50 91.40 2 89.46 92.89 I 85.62 89.96 I 87-54 91-43 I 89.50 92.91 85-65 89-99 87.58 91.46 89-54 92.94 0-8339 85.69 90.02 0.8289 87.62 91.49 0.8239 89-58 92.97 8 85-73 90.05 8 87-65 91-52 8 89.62 93.00 7 85-77 90.08 7 87.69 91-55 7 89.65 93-03 6 85.81 90.11 6 87-73 91-57 6 89.69 93.06 5 85-85 90.14 5 87-77 91.60 5 89-73 93-09 4 85.88 90.17 4 87.81 91.63 4 89.77 93-11 3 85-92 90.20 3 87-85 91.66 3 89.81 93-14 2 85.96 90.23 2 87.88 91.69 2 89.85 93-17 I 86.00 90.26 I 87.92 91.72 I 89.88 93.20 86.04 90.29 1 87.96 91-75 89.92 93-23 ALCOHOLIC BEyERACES. 673 SPECIFIC GRAVITY AND PERCENTAGE OF KLCOnOl^— {Continued). Absolute Alcohol. Absolute Alcohol. Absolute Alcohol. Spec. Grav. at Spec. Grav. at Spec. Grav. at Per Per Per Per Per Per 15.6° c. Cent Cent 15.6° C. Cent Cent 15.6° C. Cent Cent by by Vol- by by Vol- by by Vol- Weight. ume. Weight. ume. Weight. ume. 0.8229 89.96 93.26 0.8179 91-75 94-53 0.8129 93-59 95-84 8 90.00 93-29 8 91.79 94-56 8 93-63 95-87 7 90.04 93-31 7 91.82 94-59 7 93-67 95-90 6 90.07 93-34 6 91.86 94.61 6 93-70 95-92 5 90.11 93-36 5 91.89 94-64 5 93-74 95-95 4 90.14 93-39 4 91-93 94.66 4 93-78 95-97 3 90.18 93-41 3 91.96 94.69 3 93-81 96.00 2 90.21 93-44 2 92.00 94-71 2 93-85 96.03 I 90.25 93-47 I 92.04 94-74 I 93-89 96-05 90.29 93-49 92.07 94-76 93-92 96.08 0.8219 90.32 93-52 0.8169 92.11 94-79 0.8119 93-96 96.11 8 90.36 93-74 8 92-15 94.82 8 94.00 96.13 7 ' 90-39 93-57 7 92.18 94-84 7 94-03 96.16 6 90-43 93-59 6 92.22 94.87 6 94.07 96.18 5 90.46 93.62 5 92.26 94-90 5 94.10 96.20 4 90.50 93-64 4 92.30 94.92 4 94.14 96.22 3 90-54 93-67 3 92-33 94-95 3 94.17 96.25 2 90-57 93-70 j / 2 92-37 94-98 2 94-21 96.27 I 90.61 93-72 I 92.41 95-00 I 94-24 96.29 90.64 93-75 92-44 95-03 94.28 96-32 0.8209 90.68 93-77 0.8159 92.48 95-06 0.8109 94-31 96-34 8 90.71 93.80 8 92.52 95-08 8 94-34 96-36 7 90-75 93.82 7 92-55 95-" 7 94-38 96-39 6 90.79 93-85 6 92-59 95-13 6 94.41 96.41 5 90.82 93-87 5 92.63 95.16 5 94-45 96-43 4 9c. 86 93-90 4 92.67 95-19 4 94-48 96.46 3 90.89 93-93 3 92.70 95-21 3 94-52 96.48 2 90-93 93-95 2 92-74 95-24 2 94-55 96.50 I 90.96 93-98 I 92.78 95-27 I 94-59 96-53 91.00 94.00 92.81 95-29 94.62 96-55 0.8199 91.04 94-03 0.8149 92.85 95-32 0.8099 94.65 96-57 8 91.07 94-05 8 92.89 95-35 8 94.69 96.60 7 91.11 94.08 7 92.92 95-37 7 94-73 96.62 6 91.14 94.10 6 92.96 95-40 6 94-76 96.64 5 91.18 94-13 5 93.00 95.42 5 94.80 96.67 4 91.21 94-15 4 93-04 95-45 4 94-83 96.69 3 91-25 94.18 3 93-07 95.48 3 94.86 96.71 2 91.29 94-21 2 93-11 95-50 2 94.90 96-74 I 91.32 94-23 I 93-15 95-53 I 94-93 96.76 91.36 94.26 93.18 95-55 94-97 96.78 0.8189 91-39 94.28 0.8139 93.22 95-58 0.8089 95.00 96.80 8 91-43 94-31 8 93.26 95.61 8 95.04 96.83 7 91.46 94-33 7 93-30 95-63 7 95-07 q6.8c; 6 91.50 94-36 6 93-33 95-66 6 95-" 96.88 5 91-54 94-38 5 93-37 95-69 5 95-14 96.90 4 91-57 94.41 4 93-41 95-71 4 95.18 96-93 3 91.61 94-43 3 93-44 95-74 3 95-21 96-95 2 91.64 94.46 2 93-48 95.76 2 95-25 96.98 I 91.68 94-48 I 93-52 95-79 I 95-29 97.00 91.71 94-51 93-55 95.82 95-32 97.02 674 f^OOD INSPECTION AND ANALYSIS. SPECIFIC GRAVITY AND PERCENTAGE OF M.COHO'L— {Continued). Absolute Alcohol. Absolute Alcohol. Spec. Absolute Alcohol. Spec. Spec. Qrav Per Per Grav. Per Per Grav. at 15.6" C. Per Per at Cent Cent at 15.6° C. Cent Cent Cent Cent 15-6° C. by by Vol- by by Vol- by by Vol- Weight. ume. Weight. ume. Weight. ume. 0.8079 95-36 97-05 0.8029 97.07 98.18 0.7979 98.69 99.18 Q 95-39 97.07 8 97.10 98.20 8 98.72 99.20 7 95-43 97.10 7 97-13 98.22 7 98.75 99.22 6 95-46 97.12 6 97.16 98.24 6 98.78 99-24 5 95-50 97-15 5 97.20 98.27 5 98.81 99.26 4 95-54 97.17 4 97-23 98.29 4 98.84 99.27 3 95-57 97.20 3 97.26 98.31 3 98.87 99.29 2 95.61 97.22 2 97-30 98-33 2 98.91 99.31 I 95-64 97.24 I 97-33 98-35 I 98.94 99-33 95.68 97.27 97-37 98.37 98.97 99-35 0.8069 95-71 97.29 0.8019 97-40 98.39 0.7969 99.00 99-37 8 95-75 97-32 8 97-43 98.42 8 99-03 99-39 7 95-79 97-34 7 97.46 98.44 7 99.06 99.41 6 95-82 97-37 6 97-50 98.46 6 99.10 99-43 S 95-86 97-39 5 97-53 98.48 5 99-13 99-45 4 95-89 97.41 4 97-57 98.50 4 99.16 99-47 3 95-93 97-44 3 97.60 98.52 3 99.19 99-49 2 95-96 97-46 2 97-63 98.54 2 99-23 99-51 I 96.00 97-49 I 97.66 98.56 I 99.26 99-53 96.03 97-51 97.70 98-59 99.29 99-55 0.8059 96.07 97-53 0.8009 97-73 98.61 0-7959 99-32 99-57 8 96.10 97-55 8 97-76 98.63 8 99-36 99-59 7 96.13 97-57 7 97.80 98.65 7 99-39 99.61 6 96.16 97.60 6 97-83 98.67 6 99.42 99-63 5 96.20 97.62 5 97.87 98.69 5 99-45 99.65 4 96-23 97.64 4 97.90 98.71 4 99.48 99.67 3 96.26 97.66 3 97-93 98.74 3 99-52 99.69 2 96.30 97.68 2 97-96 98.76 2 99-55 99.71 I 96-33 97.70 I 98.00 98.78 I 99-58 99.73 96-37 97-73 98.03 98.80 99.61 99-75 0.8049 96.40 97-75 0.7999 98.06 98.82 0.7949 99-65 99-77 8 96.43 97-77 8 98.09 98.83 8 99.68 99.80 7 96.46 97-79 7 98.12 98.85 7 99.71 99.82 6 96.50 97.81 6 98.16 98.87 6 99-74 99-84 5 96.53 97-83 5 98.19 98.89 5 99.78 99.86 4 96.57 97.86 4 98.22 98.91 4 99-81 99.88 3 96.60 97.88 3 98.25 98.93 3 99.84 99.90 2 96-63 97.90 2 98.28 98-94 2 99.87 99.92 I 96.66 97.92 I 98.31 98.96 I 99.90 99.94 96.70 97-94 98-34 98.98 99-94 99.96 0.8039 96-73 97.96 0.7989 98.37 99.00 0.7939 99-97 99.98 8 96.76 97.98 8 98.41 99.02 7 96.80 98.01 7 98.44 99.04 Abs. Ale. 6 96.83 98.03 6 98.47 99-05 0.7938 100.00 100.00 5 96.87 98.05 5 98-50 99.07 4 96.90 98.07 4 98-53 99.09 3 96.93 98.09 3 98-56 99.11 2 96.96 98.11 2 98-59 99-13 I 97.00 98.14 I 98.62 99-15 97-03 98.16 98.66 99.16 ALCOHOLIC BEVERAGES. ^IS (4) Determination of Alcohol by the Ebullioscope or Vaporimeter is based on the variation in boiling-point of mixtures of alcohol and water, in accordance with the amount of alcohol present. There are various forms of this instrument, one of the simplest and most convenient being that of Salleron, Fig. 113, the apparatus being known in France as an 100" -99-i -98 -1^96 r95-g J - 194 10 3-12 -U -16 -18 Fig. 113. — Salleron's Ebullioscope and Scale for Calculation of Results. ebulliometer. This consists of a jacketed metallic reservoir, heated by a lamp placed beneath, and fitted with a return-flow condenser at the top and with a delicate thermometer graduated in tenths of a degree. As the boiling-point of water varies with the atmospheric pressure, it is necessary to determine the actual boiling-point corresponding with the barometric conditions each time a series of determinations are made. 676 FOOD INSPECTION AND ANALYSIS. This is done by boiling a measured portion of distilled water in the reser- voir, and carefully noting the temperature when it becomes constant. The reservoir is then rinsed out with a little of the liquor to be tested^ after which a measured amount of this liquor is boiled in the reservoir and the temperature again noted. A sliding scale (Fig. 113) accompanies the instrument, having three graduated parts as shown. The central movable portion is graduated in degrees and tenths of a degree centi- grade, the part at the left has the per cent of alcohol corresponding to the temperature in the case of simple mixtures of alcohol and water, while the part at the right is used for reading the per cent in the case of wine, cider, beer, etc., which have a considerable residue. The movable scale bearing the degrees of temperature is first set with the actual tem- perature of boiling water (as ascertained) opposite the o mark on the- stationary scale. Suppose the temperature of boiling water has been found to be 100.1°. The scale is in this case set as shown in Fig. 113. Suppose also the temperature of boiling of the wine to be tested is found to be 89.3°. From the right-hand scale the corresponding per cent of alcohol is found to be 17.2. When the liquor to be tested contains more than 25% of alcohol, it is necessary to dilute with a measured amount of distilled water and calculate the per cent from the dilution. When once the boiling-point of water has been determined for a given barometric pressure, it is unnecessary to change the position of the slid- ing scale during a series of alcohol determinations unless that pressure changes. Expression of Results. — Some confusion is caused by the three ways of expressing results of the alcohol determination, whether as per cent by weight, per cent by volume, or grams per 100 cc. The particular mode adopted should depend upon the nature of the case and upon the prevail- ing custom. In laboratory' analyses, unless otherwise quahfied, the simple expression of "per cent" usually implies per cent by weight, and for the reason that this conforms with other determinations, the adoption 'of the weight-percentage plan is perhaps most natural to the chemist on the grounds of uniformity. In enforcing the laws regulating the liquor traffic, the custom leans to volume percentage, and many of the laws are based on the "volume of .alcohol at 6o°F." (see p. 656). In recent years many European analysts have adopted the custom of e:^ressing results of analyses of wines and other liquors in grams per ALCOHOLIC BEVERAGES. 677 TOO cc. and, in order to have a common basis of comparison between the composition of American and of European wines, this manner of expression has to some extent been adopted in the United States. Proof-spirit in the United States is an alcoholic liquor containing 50% of absolute alcohol by volume at 15.6° C. A common method of express- ing alcohol is in '' degree proof " or simply " proof," which in the United States is twice the per cent of alcohol by volume. TTius, 91.3 proof or degree proof is the same as 45.65% alcohol by volume. English Proof-spirit differs from that in the United States in that it contains 49.24% by weight, or 57.06% by volume of absolute alcohol at 15.6° C. Strength is expressed in degrees over or under proof. Thus liquor 20° under proof has 80 parts by volume of proof-spirit and 20 parts of water at 15.6° C, while 20° over-proof means that 100 volumes of the liquor hav.e to be diluted to 120 volumes with water to yield proof-spirit. To calculate the per cent by volume of English proof-spirit from the per cent of alcohol by volume, divide the latter by 0.5706, or multiply it by I-7525- Direct Determination of Extract. — In liquors having a high sugar content, the extract or total solids cannot be determined accurately by evaporation at the temperature of boiling water, owing to the dehydra- tion of the reducing sugars at temperatures exceeding 75°. When extreme accuracy is required, such liquors should be dried in vacuo at 75°, or in a McGill oven (p. 586). Approximate results satisfactory in most cases are obtained by heat- ing for two and one-half hours 10 grams of the liquor in a tared platinum dish at the temperature of boiling water. If the results are to be expressed in grams per 100 cc, instead of weighing out 10 grams, 10 cc. of the liquor are measured by a pipette into a tared dish. With distilled liquors having low residues, accurate results are obtainable by direct evaporation at 100°, using preferably 25 grams or 25 cc. according as the result is to be expressed in per cent by weight or grams per 100 cc. Extract in wine and beer is more readily calculated indirectly from their specific gravity as noted elsewhere. Determination of Ash. — The residue from the determination of the exiract is incinerated to a white ash in the original dish at a low red heat, either over a Bunsen flame or in a muffle. The dish is finally cooled in a desiccator and weighed. Preservatives and Artificial Sweeteners in liquors are identified as. described in Chapters XVIII and XIX. 678 FOOD INSPECTION AND ANALYSIS. FERMENTED LIQUORS. The fermented juices of many varieties of fruits and berries furnish beverages more or less popular in various localities, especially for home -consumption, though, with the exception of the products of the apple and the grape, few of them are found on the market. The following table shows the average percentage of sugar and free acid in the expressed juice or must of fruits, according to Fresenius, arranged in the order of their sugar content: Per Cent Sugar. Per Cent Free Acid as Malic. Peaches 1.99 2.13 2.80 4-18 4.84 5-32 6.89 7-30 7-56 8.00 8.43 9.14 10.00 10.44 15-30 16.15 0.85 1.29 1.72 0.67 1.80 1.42 1-57 2-43 1.08 1.63 0.09 •0.82 2.02 1.52 0.88 0.80 Plums Green gages . . , German prunes Mulberries Sour cherries. .......... Sweet cherries Grapes. ............... CIDER. Cider is the expressed juice of the apple. When fresh and before fermentation has set in, it is known as sweet cider, but it does not long remain in this condition, developing after a good fermentation from 3 to 6 per cent of alcohol by volume. The predominating yeast under the influence of which the fermenta- tion of cider takes place is Saccharomyces apiculatus, found in consider- able quantity on the outside of the apples as well as in the soil in which the trees grow. Process of Manufacture. — The best cider is made from ripe fruit, taking care to avoid the green and the rotten apples, both of which impair the quality of the product. After gathering, the apples are best allowed to Stand in piles until perfectly ripe, being kept under cover. If exposed to the weather, certain of the yeast organisms found on the skins of the apples that are useful in promoting subsequent fermentation would be ALCOHOLIC BEf^ERAGES. 679 washed off. As a rule the apples commonly used by farmers for cider- making are those that are unsalable or unfit for other purposes, being chiefly windfalls or bruised and imperfect fruit. The apples are usually first crushed in a mill to a coarse pulp, which is afterward subjected to pressure in a suitable press and the juice thus extracted. In this country but little attention is paid to the after processes, the juice being usually transferred directly to barrels, which are not always particularly clean, and allowed to ferment spontaneously in a convenient place, subject to changes in temperature. There is little wonder that cider so made will keep but a short time and quickly goes over into vinegar, unless salicylic acid or other antiseptic is added. In France more care is taken to regulate the temperature of fermen- tation, to insure absolute cleanness of all receptacles, and to separate out contaminating impurities. A preliminar}' fermentation is usually given to the juice in open vats, during which the yeast spores are developed, while impurities separate out both by rising to the surface and by settling to the bottom, care being taken to avoid the develop- ment of acetic fermentation. At the proper time the juice is "racked off" or drawn from the clear portion between the top and bottom, trans- ferred to scrupulously clean barrels, and allowed to undergo a second fermentation at a lower temperature than before. Sometimes the "racking off" is repeated, and the juice is further clarified by "fining" or treating with isinglass, which carries down certain albuminous substances. Cider thus made is capable of keeping a ver}' long time. In England cider is sometimes "fined" by treatment with milk, one quart of the latter being added to eighteen gallons of cider. The apple pomace, left as a residue, is generally steeped in water and repressed. The juice from the second pressing is occasionally added to the first for cider manufacture, but more often is concentrated and made into apple jelly, or used as a fortifier for vinegar to make up deficiency in solids. Composition of Cider. — The following tables, due to Browne,* show the chemical composition of the freshly expressed juice of several American varieties of apple, as well as that of a few fermented samples of cider of known purity. * Peiin. Dept. of Agric, BviL 58. 6?o FOOD INSPECTION AND ANALYSIS. APPLE JUICES. Red astrachan . . . . Early harvest Yellow transparent Early strawberry. . Sweet bough Baldwin, green. ... ' ' ripe Ben Davis Bellflower Tulpahocken Unknown ao 05317 05522 05020 04949 04979 07362 05389 06270 05727 05901 11.781 13-29 II. 71 II. 81 11.87 11.36 16.82 12.77 14.90 13-94 13-75 6.87 3- 7-49 8-03 3- 2. 5-47 7.61 6 96 4- 3- I. 7-97 7- 7. II 9.06 9.68 3- 4- 3- 10.52 2. •63 -97 tic> n! bo , io.50|io 11.46:11 10.14I10 9.681 9 10.69 10 8.59I 8 15-02J15 10.96 II 13-3813 12.79I12 12.83I12 i 0! S^ X. '- «■ Alkalinity Ash, as K2CO3 per Liter. "(3 •0 -59 2.94 Minimum. . . I. 0012 I.I 22.62 Trace Trace 2.48 2.C4 4.20 1-47 Six samples of bottled "sweet" cider purchased in IMassachusetts were analyzed in the Food and Drug Laboratory of the Board of Health with the following results: y^ ' Per Cent Alcohol by Weight. Per Cent Acid as MaUc. Per Cent Extract. Maximum 8.00 3-55 5-71 0.72 0.48 0.58 7.82 2.42 4.19 Minimum Average Browne gives the following as the composition of the mixed ash of several varieties of apple: Ingredient. Per- cent- age. Ingredient. Per- cent- age. Potash (K,0) SodaCNaP) Lime (CaO) Magnesia (MgO) Oxide of iron (FeoOg) Oxide of aluminum (AljOj) Chlorine (CI) Silica (SiO^) Sulphuric acid (SO3) Phosphoric acid (P2O5) Carbonic acid (COj) Deduct oxygen equivalent to CI Total 55-94 0.31 4-43 3-78 0-9S 0.80 0-39 0.40 2.66 ' 8.64 21.60 99.90 .09 99. Si W Potassium carbonate (KjCOg)... Potassium phosphate (K3PO4). .. Sodium chloride (NaCl) Calcium sulphate (CaSO^) Calcium oxide (CaO) Magnesium phosphate (MggPgO^) Magnesium oxide (MgO) Ferric oxide (FeoOg) Aluminum oxide (AI2O3) Silica (SiOj) Total 6.85 14-5S 0.60 4-52 2.57 6.97 0.59 0.95 0.80 0.40 99.80 682 FOOD INSPECTION /tND ANALYSIS. Burcker * gives the following composition of the ash of cider: Per Cent. Silica o . 94 Phosphoric acid 12 .68 Lime 2-77 Magnesia 2 .05 Oxides of iron and manganese o. 94 Potash 53.74 Soda 1 . 10 Carbonic acid 25 . 78 100.00 Adulteration of Cider. — The Committee on Standards of the A. O. A. C. have submitted for adoption the following standards for cider: Alcohol not more than 8%, extract not less than 1.8% determined by evaporation in an open vessel at ordinary atmospheric pressure and at the tempera- ture of boiling water; ash not less than 0.2%. Entirely factitious cider made from other than apple stock is rarely found, though the product as sold is frequently of inferior quality and adulterated. The chief adulterants are water and sugar, and the use of antiseptics is common, especially of salicylic and sulphurous acids, sodium benzoate, and occasionally beta-naphthol. Sodium carbonate is sometimes added to cider to neutralize the acid and thus prevent acetic fermentation. An abnormally high ash (say in excess of 0.35%) would point toward the presence of added alkali. Watering is apparent when the content of alcohol, solids, and ash of the suspected sample are found to be considerably below the corre- sponding constants of pure cider. According to Sangle Ferriere, the following are the minimum figures for these constants in a pure cider, so that a sample may safely be pronounced as watered if they all run distinctly below: Alcohol - 3% by volume Extract 1.8% Ash 0.17% Besides these determinations, it is useful also to determine the fixed and volatile acids. Caramel is to be looked for, especially in watered samples. Other * Les Falsifications des Substances Alimentaires, p. 176. yiLCOHOLIC BEVERAGES. 685 adulterants alleged to be of frequent occurrence in French cider, but not commonly found in this country are commercial glucose, tartaric acid (to increase the acidity of a watered product), and coal-tar colors. Absence or deficiency of malates is conclusive evidence of fraud, indicating the admixture of notable quantities of the juice of the second pressing of pomace. Sugar is rendered apparent by the right-handed polarization of the sample, pure cider always polarizing well to the left. If after inversion of a dextro-rotary cider the polarization is still to the right, commercial glucose is indicated; if the reading after inversion is to the left, cane sugar has undoubtedly been added. Frequently the analyst has only to determine the alcohol, especially in cases of seizure, to ascertain whether or not there has been violation of the liquor laws. PERRY OR PEAR CIDER. This is a common French product, but is rarely if ever found on sale- in this country, though sometimes made for home consumption. In. composition and in method of manufacture it much resembles apple cider. It is also subject to the same forms of adulteration. The following table summarizes a number of analyses made by Truelle on pear juice, or must, amounts being expressed in parts per thousand : Mean. Maximum. Minimum. Specific gravity Invert sugar Sucrose Total fermentable sugars (as dextrose) Tannin Pectin and albuminous substances Acidity (as sulphuric acid) 1.0845 145.64 36-74 184.14 1.78 13.08 1-47 1.0675 108.10 16. 6<) 143-78 1. 01 3 0.76 1.0980 200 61.41 220 ^.20 18 2.40 The following analysis of champagne perry is taken from the Lancet of October i, 1892: Alcohol by weight i . 45 Alcohol by volume i . 80 Solids II .00 Ash 0.35 '684 FOOD INSPECTION /1ND ANALYSIS. WINE. Wine in its broadest sense is the fermented expressed juice of any iruit, though the term, unless otherwise restricted, is generally understood to apply to the juice of the grape. The organism present in grape juice that plays the chief part in its alcoholic fermentation is the Saccharomyces ellipsoideus, a yeast which exists on the skins of the grape. Process of Manufacture. — The grapes, which should be fully ripe, are picked and sometimes sorted, according to the care that is taken in grading the product. They are also sometimes freed from the stems, which contain considerable tannic acid, and which when crushed with the grapes impart a certain astringency to the final product. The grapes are crushed either by machinery or by the bare feet, and the juice is pressed out from the pulp in various ways, by screw or hydraulic press, or by the centrifugal process. A certain amount of juice runs off from the preliminary crushing .known as the first run, and makes the choicest wine. The product from the pressure constitutes the second run, after which the pomace, by steep- ing in water and repressing, is made to yield an inferior juice used in vinegar-making. Red wines are made from dark grapes by fermenting the pulp, before pressing, with the skins, which by this treatment yield up their rich color (oenocyanin) to the juice. Besides the color, the skins contain also tannin. White wine is made from the pressed pulp, freed from the skins at once, or from the pulp of white grapes. The unfermented must constitutes from 60 to 80 per cent of the weight of the grape. Fermentation progresses most rapidly at a temperature between 25° and 30° C, but wine having a much finer bouquet is produced by slower fermentation, hence the must is allowed to ferment in open vats or tubs in cool cellars, at a temperature of from 5° to 15° till it settles out com- paratively clear, special care being taken to avoid development of acetic fermentation. At the end of the first or active fermentation, the wine is drawn off and allowed to undergo a second or slow fermentation in casks, during which most of the lees or crude argols, composed of potas- sium bitartrate, settle out, being insoluble in alcohol, and the characteristic bouquet or flavor of the wine is developed. Occasionally during this process the wine is racked or drawn off. Undesirable fermentations and vegetable fungus growth, which are ALCOHOLIC BEVERAGES. 685 liable to occur at this time, are avoided as much as possible by using especially clean casks, which are frequently "sulphured" (or burnt out with sulphur) before being used. The wine is also sometimes clarified, or "fined," by treatment with gelatin, which mechanically removes many impurities by precipitation, or is subjected to pasteurization before finally being bottled or stored in casks. Classification of Wines.— Wines are either natural or jortified. Nat- ural wines are those which contain no added sugar or alcohol, but which dre exclusively the product of the simple juice, fermented under the best conditions, either till the sugar has been used up, or till the yeast food is exhausted, or until the yeast growth has been checked by the strength of the alcohol developed. When the alcohol content amounts to 14% by weight there can be no further fermentation due to yeast, so that this is the highest limit for natural wine. Examples of natural wines are hock and claret and many California wines. Fortified wines are those to which alcohol has been added, usually before the natural fermentation has been allowed to proceed to a finish. For this reason considerable sugar is usually left, and such wines are more often sweet. Examples of fortified wines are Madeira, sherry, and port. Volatile ethers (products of volatile acids) predominate as a rule in natural wines, while fixed ethers (from the fixed acids as tartaric) are most characteristic in fortified wines. Wines are also variously classified according to characteristic proper- ties possessed by them, as still or sparkling, red or white, '^dry'^ or sweet, etc. Still wines are those in v/hich there is but little carbon dioxide remain- ing, so that they do not effervesce. Sparkling wines are more or less heavily charged with carbon dioxide, either naturally, as in the case of champagne, wherein the gas is formed by after-fermentation of added sugar in the corked bottle, or artificially, by carbonating them in a similar manner to "soda-water." Among the best-known red wines are those of Burgundy and the Bordeaux wines or clarets, while the Rhenish and Moselle wines and the Sautemes are examples of white wine. "Dry" wines are those in which the sugar has been exhausted by fermentation, while sweet wines possess a considerable amount of unfer- mented sugar. Whether or not an excess of sugar is left after fermenta- tion has stopped depends upon the amount of yeast food or nitrogenous substance present in the wine. When the proteins are exhausted by the 686 FOOD INSPECTION /IND ANALYSIS. yeast, fermentation ceases, and for this reason gelatin and other nitrog-- enous bodies are sometimes added to extend the period of fermentation.- Sweet wines are often reinforced by the addition of sugar. Madeira, both red and white, are samples of dry wine, while port wine is one of' the sweet variety. While most of our finer wines still come from France and Germany,, large quantities of California wines are now being produced of an extremely high grade and of many varieties. Composition of Grape Must and of Wine. — Konig's analyses of a. large number of grape musts from different sources are thus summarized: Specific Gravity. Water, Per Cent. Nitroge- nous Ma- terial. Sugar. Acid. Other Non-ni- trogenous Material. Ash. Minimum I . 0690 1.2075 J .1024 51-53 82.10 74-49 O.II 0-57 0.28 12.89 35-45 19.71 0.20 1. 18 0.64 1.68 11.62 4-48 0.20 Maximum 0.6; Mean 0.40 Typical analyses of German, French, Austrian, Russian, Italian, and' Spanish wines are shown in the following table, also due to Konig: 11 w 1 <; t. 1^ ."2 ^ "o u c "I o'&6 Germany: 14 23 46 IS 6 IS 10 29 5 60 17 10 12 20 7 4 0.9964 1.0005 0.9995 0.9967 0.9982 0.9963 0.9940 0.9927 0.9939 0.9931 1.0233 7-99 8.00 6.65 6.10 4-73 6.59 8.08 7.80 8.30 9.08 8.84 10.76 11.96 10.61 12.30 12.78 2.24 2.60 2.16 2.27 2.64 2.07 2.27 2.56 3-03 2.34 1.87 2.76 2.568 3-44 3-53 9.69 0.79 0.81 0.91 0-95 1. 14 0.696 0.56 0-57 0.66 0.62 0-S9 .0.56 0.49 0.52 0.49 0-59 0.031. Rhine 0.018 0.095 0.091 0.018 0.032 0.20 0.358 0.262 0.026 0.168 0.052 o-iSS Baden 0.095 Wurtemburg, white wine. " red wine.. Alsace ................ Lorraine, red wine Prance : Red wine 0.088 0.30. White wine 0.142 O.IOO Austria: Tyrol, red wine . ' ' white wine Russia: Red wine White wine 0.458' 1.44 0.38 6-5S Italy Spain: Ordinary red wine b wcet wine ALCOHOLIC BEyERAGES. 687 d ■u -J < 6 J .5 c bo CO "C Germany: Moselle Rhine 0.72 0.85 0.49 0-57 0.4L 0.5c 0.73 0.97 0.65 0.65 0.64 °-59 0.45 1.09 0.63 0.028 0.019 0.043 0.021 0.020 0.036 0.026 0-175 0.23 0.207 0.25 0.25 o.22g 0.185 0.248 0.25 0.222 0-175 0.267 0.204 0.29 0.61 0.74 0.036 0.046 0.025 0.043 0.040 0.038 0.030 0.030 0.032 0.027 0.022 0.027 0.030 0.032 0.027 0.039 0.068 0.085 . 1 1 5 0.108 O.OII 0.017 0.02 0.022 O.OI21 0.02c Baden Wurtemburg, white wine. 0.009 0.021 0.08 j " red wine. . Alsace 0.024 O.OIO 0.008 France : Red wine 0.106 0.098 O.IOI O.OIO 0.018 0.015 0-033 0.038 0.023 0.023 0.019 0.221 0.212 White wine Austria: 0.077 O.III 0.086 0.II5 0.242 0.296 Russia: Red wine 0.009 0.008 0.017 White wine Italy Spain: Ordinary red v.dne Sweet wine On page 688 arc given summaries of analyses of American wines compiled from tables of analyses made by Bigelow.* Varieties of "Wine. — Champagne is a selected, sweet, white wine, clarified with gelatin, bottled with the addition of cane sugar, mixed with a little brandy, and tightly corked. Sometimes a small amount of yeast is also introduced. Fermentation is allowed to go on at a temperature of about 24° C, during which the wine is highly charged with carbon dioxide. The bottles are set on their side for some months, after which they are inverted till the sediment gathers above the cork, which by careful manipulation is quickly removed so as to throw out the sediment, and is afterward replaced and secured. Champagne contains from 8 to 10 per cent of alcohol and is high in sugar. Claret is a light, red wine of a deep color, and is somewhat acid and astringent. In alcohol it varies from 8 to 13 per cent by volume. It has very little sugar and is high in volatile ethers. Madeira is a strong, white wine, possessing a refined, nutty, aromatic flavor when fully aged. It is generally fortified, containing from 17 to 20 per cent of alcohol. It is named from the island which produces it. Sherry is a deep, amber-colored, sweet, Spanish wine, high in alcohol * U, S. Dept. of Agric, Bur. of Chem., Bui. 59, ;' 688 FOOD INSPECTION AND ANALYSIS. •qsy puB illUUBJ, ■sppiojj •aiBqding uinissB^lOfj •jB3ng Supnpa-g O 00 w 00 ■4- « OOO QOO 'tf) »OvO vOu^ O^t- 0\C» roio fOO WW CON 'tM 0\ "H fO M 00 fO ro O t O ro O Tt ro o o o o mo •* IT) in 00 IT) M 00 'O ^00 LO to M IT) M 00 0^ CO M On •O 00 t-- 0\ lo uo M OS fDOO t^OO ro O On w •* O M rn 00 m _ Tf ^ Tt- t^ ro Tt u-> NO On On r--NO NO -+ 00 LO 11 to M O « o M O O^ On no On NO O rONO to O On O OnOO O on to Tf CM On CO r-» CO NO Tf O NO CO N r^ M On CO o o CO ■& too •9uin[0^ Aq [oqooiv iua3 jaj O On 00 O PI O coo •XiiABjg oijtoadg O O r^ Tf ON ON c c ON On On On O CO t-~. P) c) 00 to On O 00 - 00 O On O On 00 CJ CO 00 ONOO On On •saiduiBg JO jaquiTHi^ ^ iS is u D 3 s s>§ s •S ^ c e4 is g 3 S gp^ S g .s s S.s e S.s T> 3 p;; on 6 5-2 6? 6 S 3.5 S i'.S S t, s g is sil 73 S g ALCOHOLIC BEyERAGES. 6«9 (sometimes containing over 20%), being usually fortified. It is slightly acid and possesses much fragrance. Sherry is nearly always "plastered." Hocks are white German wines, mildly acid, containing 9 to 12 per cent of alcohol by volume. They have very little sugar, and rank among '.he highest of natural wines. The best-known varieties are Hockheimer and Johanlsberger. Port (Vinum poriense of the 1870 Pharmacopoeia) is a dark-purple, astringent wine, almost always fortified, and hence high in alcohol (from 15 to 18 per cent by volume). It is much improved by aging, during which it looses considerable of its astringency. It contains a large amount of extract, from 2 to 6 per cent of the wine being sugar. The fixed ethers predominate over the volatile. Standards of Purity for Wine. — The ratio of volatile to fixed acids in pure wine should not exceed 1:3. A higher proportion of volatile acid shows the fact that acetic fermentation has set in. The presence of any considerable free tartaric acid would indicate the addition of this substance to the wine. The United States Pharmacopoeia has prescribed the following require- ments in the case of wines: For white wine {Vinum album) the specific gravity at 15.6° should not be less than 0.990 nor more than i.oio; the extract or residue at 100° should not be less than 1.5 nor more than 3%; as indicating the amount of free acid, not less than 3 nor more than 5.2 cc. normal potassium hydroxide should be required to neutralize 50 cc. of the wine, using phenolphthalein as an indicator; it should contain not less than 7 nor more than 12 per cent by weight of absolute alcohol; it should contain only traces of tannin. For red wine {Vinum ruhum) the specific gravity at 15.6° should not be less than 0.98Q nor more than i.oio; the extract should not be less than 1.6% nor more than 3.5%; its limits as to acidity are the same as with white wine, cosin or fluorescin, however, being used as an indicator; in alcoholic strength, it should, like white wine, come within the limits of 7 and 12 per cent alcohol by weight. It should not be artificially colored, but should show the presence of tannic acid. The following arc U. S. standards for wines: Wine is the product made by the normal alcoholic fermentation of the juice of sound, ripe grapes, and the usual cellar treatment, and contains not less than 7 nor more than 16 per cent of alcohol, by volume, and, in 100 cc. (20° C), Cgo FOOD INSPECTION AND ANALYSIS. not more than o.i gram of sodium chloride nor more than 0.2 gram of potassium sulphate; and for red wine not more than 0.14 gram, and for white wine not more than 0.12 gram of volatile acids produced by fermentation and calculated as acetic acid. Red wine is wine contain- ing the red coloring matter of the skins of grape. White wine is wine made from white grapes or the expressed fresh juice of other grapes. Dry wine js wine in which the fermentation of the sugars is practically complete, and which contains, in ipo cc. (20° C), less than i gram of sugars, and for dry red wine not less than 0.16 gram of grape ash and not less than 1.6 grams of sugar-free grape solids, and for dry white wine not less than 0.13 gram of grape ash and not less than 1.4 grams of sugar-free grape solids. Fortified dry wine is dry wine to which brandy has been added, but which conforms in all other particulars to the standard of dry wine. Sweet wine is wine in which the alcoholic fermentation has been arrested, and which contains, in 100 cc. (20° C), not less than I gram of sugars, and for sweet red wine not less than 0.16 gram of grape ash, and for sweet white wine not less than 0.13 gram of grape ash. Fortified sweet wine is sweet wine to which wine spirits have been added. By act of Congress, " sweet wine " used for making fortified sw^eet wine and " wine spirits " used for such fortification are defined as follows (sec. 43, Act. of October i, 1890, 26 Stat. 567, as amended by section 68, Act of August 27, 1894, 28 Stat. 509, and further amended by Act of Congress, approved June 7, 1906): "That the wine spirits mentioned in section 42 of this act is the product resulting from the distillation of fermented grape juice to which water may have been added, prior to, during, or after fermentation, for the sole purpose of facilitating the fermentation, and economical distillation thereof, and shall be held to include the products from grapes or their residues, com- monly known as grape brandy; and the pure sweet wine, which may be fortified free of tax, as provided in said section, is fermented grape juice only, and shall contain no other substance whatever introduced before, at the time of, or after fermentation, except as herein expressly provided; and such sweet wine shall contain not less than 4 per cent of saccharine matter, which saccharine strength may be determined ALCOHOLIC BEVERAGES. 691 "by testing with Balling's saccharometer or must scale, such sweet wine, after the evaporation of the spirits contained therein, and restoring the sample tested to original volume by addition of water: Provided, That the addition of pure boiled or condensed grape must, or pure crystallized cane or beet sugar, or pure anhydrous sugar to the pure grape juice aforesaid, or the fermented product of such grape juice prior to the fortiiication provided by this act, for the sole purpose of perfecting swc2i: wine according to commercial standard, or the addition of water in such c[uantities only as may be necessary in the mechanical operation of grape conveyors, crushers, and pipes leading to fermenting tanks, shall not be excluded by the definition of pure sweet wine aforesaid: Provided, however, That the cane or beet sugar, or pure anhydrous sugar, or water, so used shall not in either case be in excess of 10% of the weight of the wine to be fortified under this act: Afid provided further, That the addition of water herein authorized shall be under such regula- tions and . limitations as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may from time to time prescribe; but in no case shall such wines to which water has been added be eligible for fortification under the provisions of this act where the same, after fermentation and before fortification, have an alcoholic strength of less than 5% of their volume." Sparkling wine is wine in which the after part of the fermentation is completed in the bottle, the sediment being disgorged and its place supplied by wine or sugar liquor, and which contains in 100 cc. (20° C), not less than 0.12 gram of grape ash. Modified wine, ameliorated wine, corrected wine, is the product made by the alcoholic fermentation, with the usual cellar treatment, of a mixture of the juice of sound, ripe grapes with sugai (sucrose), or a syrup containing not less than 65% of sugar (sucrose), and in quantity not more than enough to raise the alcoholic strength after fermentation, to 11% by volume. Raisin wine is the product made by the alcoholic fermentation of an infusion of dried or evaporated grapes, or of a mixture of such infusion, or of raisins with grape juice. Adulteration of Wine. — Beverages purporting to be wine are sometimes found on sale that are entirely spurious, in that they con- tain httle if any fermented grape juice. Apple cider is not infrequently -the basis of such artificial products, and the following recipes given 6^2 FOOD INSPECTION AND ANALYSIS. by Brannt may be taken as typical of the composition of these wine substitutes: Burgundy. — Bring into a barrel 40 quarts of apple juice, 5 pounds of bruised raisins, \ pound of tartar, i quart of bilberry juice, and 3 pounds sugar. Allow the whole to ferment, filling constantly up with cider. Then clarify with isinglass, add about i ounce of essence of bitter almonds, and after a few weeks draw off into bottles. Malaga Wine. — Apple juice, 40 quarts; crushed raisins, 10 pounds; rectified alcohol, 2 quarts; sugar solution, 2 quarts; elderberry flowers, 1 quart ; acetic ether, i ounce and 2 drachms. The desired coloration is effected by the addition of bilberry or elderberry juice; otherwise the process is the same as given for Burgundy. Sherry Wine. — Apple juice, 50 quarts; orange-flower water, about 2 drachms; tartar, 2 ounces and 4 drachms; rectified alcohol, 3 quarts; crushed raisins, 10 pounds; acetic e^her, i ounce and 2 drachms. The process is the same as for Burgundy. Claret Wine. — Apple juice, 50 quarts; rectified alcohol, 4 quarts; black currant juice, 2 quarts; tartar, 2 ounces and 4 drachms. Color with bilberry juice. The further process is the same as for Bur- gundy. Artificial products similar in nature to the above are also mixed in varying proportions with pure wine. Presence of malates, as well as absence or diminution of total tartaric acid, is also indicative of cider. If the ash of the wine be submitted to the flame test, the sodium light will predominate in the case of pure wine, while if the basis of the sample be largely or wholly apple stock, the potash flame will be readily apparent. Wines are most frequently aduherated by "plastering," by watering; by the addition of excessive amounts of sugar or glucose, by various flavor- ing principles, by coal-tar and vegetable colors, by antiseptics, and by added alcohol. Plastering.— By this term is understood the addition of gypsum or plaster of Paris to the must before fermentation, a practice in vogue in parts of France, Italy, and Spain. The reaction which takes place with the potassium bitartrate present in the wine is, according to Chancel, as follows: ALCOHOLIC BEVERAGES. 695 2KHC,H,06+CaSO, = CaC,H,06+H,C,Hp6+K2SO,. Potassium Calcium Calcium Tartaric Potassium bitartrate sulphate tartrate acid sulphat* Various advantages are said to result from this practice. The wine is clarified by the precipitation of the calcium tartrate, which mechan- ically carries down with it many impurities, the color of the wine is- improved, since the solubility of the coloring principle present in the skins is increased, the fermentation is rendered more rapid and complete, and the keeping qualities of the wine are enhanced. The practice is, however, considered objectionable on account of the potassium sulphate which is left in solution in the wine, and in some countries plaster- ing is forbidden, or the amount of potassium sulphate limited by statute. The following are analyses of two Spanish wines made from the same grape juice, one of which was plastered. The results are expressed in grams per liter. Not Plastered. Plastered. Color Yellow 23-3 0.66 2.06 1.29 0.41 Bright red 27-3 0.61 5-38 0.17 5 Extract dried at 100° Insoluble ash Soluble ash The soluble ash containing Potassium carbonate. . . " sulphate. The effect of plastering is thus seen to distinctly increase the extract and the soluble ash. Any considerable amount of potassium sulphate is an indication of plastering. Addition of Cane Sugar. — The term "chaptalizing" is applied in France to the addition to the must of cane sugar for the purpose of increasing the yield in alcohol. The addition of 1,700 grams of sugar to 1,000 liters of must is said to increase the alcoholic strenglh by 1%.. It was formerly customary to add with the sugar calcium carbonate, to partially neutralize the acidity, but this is rarely practiced at present.. The European wine-raising countries are not disposed to regard the reinforcement of wine by added cane sugar in the must as in itself a fraud, unless water is also added, or unless some other form of adulteration is practiced at the same time. In France, however, the addition of cane '604 FOOD INSPECTION AND ANALYSIS. sugar is i)crmitted only in wine for local consumption, and is restricted in -amount. The use of commercial glucose in wine instead of cane sugar is not regarded with as much favor, in view of the fact that glucose contains more or less unfermentable matter, and introduces dextrin and various mineral salts into the wine. To ascertain uhe nature and extent of the sugars present in wine is frequently of great importance. Much information may be gained from Ihe direct and invert polarization of the sample, as well as from the deter- mination of reducing sugars. Invert sugar is the only legitimate sugar that should be present in genuine wine. In normal fermentation the dextrose is more quickly destroyed than the levulose, hence the polarization of pure wine is always left-handed, unless all the sugar has been fermented, in which case the reading should be zero. Seventy-five samples of California red wines, chiefly claret. Burgundy, Rhine, and southern France types, analyzed in the Bureau of Chemistry * of the U. S. Department of Agriculture, polarized from —0.5 to —2.1. Upwards of eighty samples of California white wine (of the types of Burgundy, Sauterne, and southern France) were submitted to polariza- tion and all but four were left-handed. These four (evidently abnormal) polarized from o. to +1. Most of them varied from — o.i to —3.5. Thirteen of the port wine types (California) had a left-handed polariza- ; tion of from —14.7 to —27.1. These apparently contained large quan- tities of unfermented, inverted cane sugar. A sharp, right-handed polarization would indicate the presence of •either commercial glucose or cane sugar. After inversion, if the reading is still right-handed, glucose is apparent, while if inversion changes the reading from right to left, cane sugar has undoubtedly been added. By application of Clerget's formula the amount of cane sugar can be estimated. The Watering of Wine, unless excessive in degree, is not always easy to prove, by reason of the varying composition of pure wine, and because the practice is usually accompanied by other forms of sophistication intended to cover up evidences of watering. Considerable quantities of added water alone would usually be rendered apparent by a propor- tionate and abnormal lowering of the alcohol, extract, ash, acidity, and, indeed, nearly all the constants. Gautier in his Traite sur la Sophistication et l^ Analyse des Vins claims * Bui. 59. /ILCOHOLIC BEVERAGES. 695 that the sum of the weight in grams of alcohol in 100 cc. and the total acidity, expressed in grams of sulphuric acid per liter, varies within very- narrow limits in pure wines, rarely being below 13 or above 17. A large number of analyses made by Gautier and others would seem to confirm this, so that in the majority of cases, added water would be strongly indicated if the sum of these two constants was materially reduced below 13. It is more conservative to adopt 12.5 as a minimum limit for the sum of the alcohol and total acid expressed as above. Detaction of Added Alcohol. — As a result of the findings of a com- mittee appointed in France to determine the matter of added alcohol, it was submitted that a relation existed between the weight of the extract and that of the alcohol in pure wine. In the case of red wines, if the weight of the alcohol, divided by the weight of the extract (both expressed in grams -per 100 cc.) exceeds 4.6, the addition of alcohol is strongly indi- cated. With white wines, the quotient obtained by dividing the weight •of alcohol by weight of extract should not exceed 6.6. If it does, added alcohol is to be suspected. In the case of plastered wines containing sulphate of potassium, or wines having added sugar, it is necessary to deduct from the total extract the weight of the reducing sugar and of the potassium sulphate as found (less 0.1 gram for each of these substances), the difference, or reduced extract as it is called, being used in this case in obtaining the ratio. Fruit Wines other than Grape. — Wines mostly of domestic manufac- ture are sometimes made from small fruits, such as raspberries, straw- berries, blackberries, gooseberries, elderberries, and currants, as well as from cherries, plums, and apricots. Wines made from most of these fruits readily undergo acetic fermentation unless antiseptics are added, or unless extreme care is taken in their manufacture and keeping. Fre- quently mixtures of various fruit juices are made to yield excellent wine. Most of the sour fruits require a liberal admixture of sugar to produce an acceptable wine. The following analysis of currant wine is due to Fresenius: Alcohol , 10.01% Free acid o. 79% Sugar 11-94% Water 77.26% The alcoholic content of other fruit wines is thus shown by Brannt: Gooseberry wine 11. 84% alcohol Elderberry wine 8 . 79% * ' Orange wine 11.26% " 606 FOOD INSPECTION AND ANALYSIS. METHODS OF ANALYSIS OF WINE AND CIDER. For determination of specific gravity, alcohol, extract (by direct method), and ash, see pp. 657-676. Calculation of the Extract in Wine. — Attention has already been called to the difficuhy in accurately determining the extract of sweet wines gravimetrically by evaporation. An approximate determination of the extract may be obtained by calculation from the specific gravity of the dealcoholized liquor, or one may use for this purpose the tables compiled iby Windisch, and based on experiments made on drying wine in vacuo 'at 75° C. In wines high in sugar, with more than 6% of extract, this method is far more accurate than drying at 100°, and is to be recommended. Evaporate a measured portion of the wine on the water-bath to one-fourth its volume, and dilute with water to exactly the volume measured. Determine the specific gravity of this dealcoholized liquid at 15-6°, and from the following table ascertain the extract corre- sponding. Determination of Total Acidity. — Carbonated beverages are first freed from carbon dioxide by agitatioi: as described on page 658, after which 25 cc. of the sample are heated just to the boiling-point and titrated with tenth-normal sodium hydroxide, using in the case of whi:;e wine or cider phenolphthalein as an indicator. With red wine delicate litmus paper should be used. Total acidity is usually expressed, in the case of cider as malic, and of wine as tartaric acid. Each cubic centimeter of tenth-normal alkali corresponds to 0.0067 gram malic, or 0.0075 gram tartaric acid. Some chemists express total acidity in terms of sulphuric acid, each cubic centimeter of tenth-normal alkali being equivalent to 0.0049 gram of sulphuric acid. Volatile Acids in all liquors are usually expressed as acetic, although traces of propionic and other volatile acids may be present. 50 cc. of the cider or wine and a little tannic acid are transferred to a distilling- fiask, Fig. 115, the stopper of which is provided with two tubes, one of which connects with the condenser, while the other, arranged to reach nearly to the bottom of the distilling-flask, communicates with a second flask which contains about 300 cc. of water. The contents of both flasks are brought to boiling, after which the flame under the distilling-flask is lowered, and steam from the water-flask is passed through the wine till about 200 cc. of distillate have collected in the receiving-flask. Titrate this with tenth-normal sodium hydroxide, using phenolphthaleins JLCOHOLIC BEVERAGES. 697 EXTRACT IN WINE. [According to Windisch.] Specific Ex- Specific Ex- Specific Ex- "1 Specific E.K- Specific Ex- Specific Ex- Gravity. tract. 1 Gravity. tract. Gravity. tract. Gravity. tract. Gravity. tract. Gravity. tract. 1 .0000 0.00 I .0065 ! 1.68 1 .0130 3.36 ! I. 0195 5.04 1 .0260 6.72 1-0325 8.40 1 .0001 0.03 I .0066 1.70 I .0131 3.38 I .0196 5.06 I .0261 6. 75 1 .0326 8.43 1 .0002 0.05 I .0067 1.73 I .0132 3.41 I .0197 5.09 I .0262 6.77 1.0327 8.46 1 .0003 0.08 I .0068 1.76 10133 3.43 I .0198 511 I .0263 6.80 1.0328 8.48 I .0004 0. 10 I .0069 1.78 I. 0134 3.46 I .0199 S.14 1 .0264 6.82 1.0329 8.51 1 .0005 0.13 I .0070 i.8i I .0135 3.49 I .0200 5-17 I . 0265 6.85 1.0330 8.53 1 .0006 0.15 I .0071 1.83 I .0136 3.51 I .0201 5.19 I .0266 6.88 1-0331 8.56 1 .0007 0.18 I .0072 I .86 I .0137 3.54 I .0202 S.22 I .0267 6.90 1-0332 8.59 1 .0008 . 20 1.0073 1.88 I .0138 3.56 I .0203 5-25 I .0268 6.93 1-0333 8.61 7 .0009 0.23 I .0074 I. 91 I. 0139 3.59 I .0204 5-27 1 .0269 6.9s I -0334 8.64 I 0010 0. 26 I. 007s 1.94 I .0140 3.62 I .0205 5.30 I .0270 6.98 I-033S 8.66 I .OOI I 0. 28 I .0076 I .96 I .0141 3.64 1 .0206 5. 32 J .0271 7.01 1.0336 8.69 I .001 2 0.31 1.0077 1.99 I .0142 3.67 1 .0207 5-35 I .0272 7.03 1.0337 8.72 I. 0013 0.34 I .0078 2 .01 I. 0143 3.69 1 .0208 5.38 1.0273 7 .06 1.0338 8.74 I .0014 0.36 I .0079 2 .04 I .0144 3.72 X .0209 5. 40 I .0274 7.08 I 0339 8-77 i.oois 0.39 I .0080 2.07 I. 0145 3.75 I .0210 S.43 I .0275 7-11 1.0340 8-79 1 .0016 0.41 I .0081 2.09 I .0146 3.77 1 .021 1 5.4s I .0276 7.13 I. 0341 8.82 I .0017 o,.44 I .0082 2.12 I. 0147 3 80 I .0212 .S.48 1.0277 7.16 1.0342 8.85 I .0018 0.46 1.0083 2.14 I .0148 3.82 I. 0213 5-51 r .0278 7.19 I 0343 8.87 1. 00 1 9 0.49 I .0084 2.17 I. 0149 3.85 I . 0214 5.53 1.0279 7.21 I 0344 8.90 I .0020 0. 52 1.008s 2.19 I .0150 3.87 1 .0215 5.56 I .0280 7.24 I .0345 8.92 I .0021 0.54 J .0086 2. 22 I .0151 3 90 I .0216 5.58 I .0281 7.26 1.0346 8-95 I ,0022 0.57 I .0087 2 . 25 I .0152 3.93 I .0217 5.61 I .0282 7.29 1.0347 8-97 1.0023 0.59 1.0088 2. 27 I. 0153 3.9s 1 .0218 5.64 I .0283 7.32 1.0348 9.00 I .0024 0.62 I .0089 2.30 I. 0154 3.98 1 .0219 5-66 I .0284 7-34 1.0349 9-03 1.0025 0.64 I .0090 2.32 I.OI55 4.00 I .O220 5.69 I .0285 7.37 1-0350 9.0s I . 0026 0.67 I .0091 2.35 I .0156 4.03 I .0220 S.71 I .0286 7-39 1.0351 9.08 I .0027 . 69 ] I .0092 2.38 1.0157 4.06 I .0222 5.74 I .0287 7.42 1-0352 9. 10 I .0028 0.72 I .0093 2 .40 I .0158 4.08 I .0223 5. 77 1.0288 7-45 1.0353 9-13 I .0029 0.7S I .0094 2.43 I. 0159 4. II I . 0224 5-79 I .0289 7-47 1-0354 9. 16 1 .0030 0.77 I .0095 2.45 I .C160 4.13 I .0225 S.82 I .0290 7.50 1-0355 9.18 I .0031 0.80 I .0096 2.48 I .0161 4.16 I .0226 5. 84 I .0291 7-52 1-0356 9. 21 1 .0032 0.82 I .0097 2.50 I .0162 4.19 I .0227 5.87 I .0292 7.55 I .0357 9-23 1.0033 0.8s I .0098 2. S3 I .0163 4.21 I .0228 5.89 1.0293 7.58 1-0358 9. 26 1.0034 0.87 I .0099 2.56 I .0164 4.24 I .0229 5-9^ I .0294 7 .60 I-0359 9.29 1.003s .90 I .0100 2.58 I .0165 4- 26 ' I .0230 5-94 I .0295 7.63 I .0360 9.31 I .0036 0.93 I .0101 2.61 I .0166 4.29 ' I .0231 5. 97 1 .0296 7.65 I. 0361 9-34 1.0037 0.9.'; I .0102 2.63 I .0167 4-31 1.0232 6.00 1.0297 7.68 1.0362 9.36 I .0038 0.98 I .0103 2.66 I. 0168 4.34 1.0233 6.02 1 .0298 7.70 1-0363 9.39 1.0039 1 .00 I .0104 2 .69 I .0169 4.37 1.0234 6.0s 1 .0299 7-73 1-0364 9-42 I 0040 1.03 I .0105 2.71 ' I .0170 4-39 1.0235 6.07 1 .0300 7.76 1.0365 9-44 I 0041 I -OS I .0106 2.74 I .0171 4.42 I .0236 6.'0 I. 0301 7.78 1.0366 9-47 I .0042 I .08 I .0107 2.76 I .0172 4.44 I .0237 6.12 1 .0302 7.81 1.0367 9.49 I .0043 I .1 1 I .0108 2.79 I. 0173 4.47 I .0238 6.15 1.0303 7.83 1.0368 9-52 I .0044 I-I3 I .0109 2.82 I. 0174 4.50 1.0239 6.18 1 .0304 7.86 r 0369 9-55 1.0045 1.16 I .0110 2.84 I. 017s 4.52 I .0240 6. 20 1.0305 7.89 1.0370 9-57 I .0046 I. 18 I .01 I I 2.87 1.0176 4. 55 I .0241 6.23 1 .0306 7. 91 1.0371 9.60 I .0047 1 . 21 I .01 12 2.89 I. 0177 4.57 I .0242 6.25 I .0307 7-94 1.0372 9.62 I .0048 1.24 I .0113 2 . 92 I .0178 4. 60 I .0243 6.28 I .0308 7-97 I .0373 9-65 I . 0049 1.26 I .0114 2.94 I. 0179 4.63 1.0244 6.31 I .0309 7-99 1.0374 9.68 r .0050 1 . 29 I .0115 2.97 I .0180 4.65 1.0245 6.33 I .0310 8.02 I-037S 9.70 I .0051 1-32 I .01 16 3 .00 I .0181 4.68 I .0246 6.36 I .0311 8.04 1.0376 9.73 I .0052 1.34 I .0117 3-02 I .0182 4.70 , 1.0247 6.38 1,0312 8.07 1.0377 9.75 I .0053 1-37 I .0118 3.0s I .0183 4.73 I .0248 6. 41 1.0313 8.09 1.0378 9.78 I .0054 '.39 I .0119 3.07 I .0184 4-75 1.0249 6.44 1.0314 8.12 1-0379 9.80 1.0055 1.42 I .0120 3.10 I .0185 4.78 1.0250 6.46 1.031S 8.14 1.0380 9.83 I .0056 1.45 I .0121 3.12 I. 0186 4.8i I .0251 6.49 1 .0316 8.17 I. 0381 9.86 1. 0057 1.47 I .0122 3. IS I .0187 4.83 I .0252 6.51 I .0317 8.20 1.0382 9.88 I .0058 1.50 I. 0123 3.18 I. 0188 4.86 I .0253 6.54 1 .0318 8.22 1.0383 9.91 1.0059 I. 52 I .0124 3.20 I .0189 4.88 I. 0254 6.56 1-0319 8.2s 1.0384 9. 93 I .0060 1-55 I. 0125 3.23 I .0190 4.91 I 0255 6.59 1 .0320 8.27 1.0385 9-96 1 .0061 1-57 I .01 2b 3.26 I .0191 4-94 I .0256 6.62 I .0321 8.30 1.0386 9-90 I .0062 1 .60 I .01 27 3.28 I .0192 4.9b I .0257 6.64 I .0322 8.33 1.0387 10.01 I .0063 1.63 I .0128 3.31 I .0193 4-99 I .0258 6.67 1.0323 8.35 1.0388 10.04 1.0064 i.6s I .0129 iii I .0194 S.oi 1.0259 6. 70 1.0324 8.38 1.0389 10.06 69S FOOD INSPECTION y^ND yINALYSIS. EXTRACT IN WINE— (Co«//»Me(i). Specific Gravity. Ex- Specific Ex- Specific Ex- Specific Ex- Specific Ex- Specific Ex- tract. Gravity. tract, i Gravity. tract. Gravity. tract. Gravity. 1 .0650 tract. 16.86 Gravity. tract. I .0390 10.09 1.0455 11.78 ! 1 .0520 13.47 1.0585 15.16 I .0715 18.56 I .0391 10. 1 1 1.0456 11.81 1.0521 13.49 1.0586 15.19 1 .0651 16.88 1 .0716 18. 58 I .03Q2 10.14 I. 0457 1 1 . 83 1.0522 13.52 1.0587 15.22 1 .0652 16.91 1.0717 18.61 1 .0393 10.17 1.0458 11.86 1.0523 13.55 1.0588 15.24 I .0653 16.94 1 .0718 18.63 1.0394 10.19 1.0459 11.88 1.0524 13.57 1.0589 i5.<27 1.0O54 16 . 96 1 .0719 18.66 1 .039s 10. 22 1 .0460 11 .91 1.0525 13.60 1.0590 1S.29 1.0655 16.99 I .0720 18.69 1.0396 10.25 I .0461 11.94 1 .0526 13-62 1.0591 iS-32 1.0656 17.01 1 .0721 18.71 1 .0397 10. 27 I .0462 11 .96 1.0527 13-6S 1.0592 15-35 1.0657, 17.04 1.0722 18.74 1.0398 10.30 1-0463 11.99 I .0528 13.68 1.0593 15-37 1.0658 17.07 1-0723 18.76 1.0399 10. 32 1 .0464 12.01 1 1.0529 13-7° \ 1.0S94 15-40 1.0659 17.09 1.0724 18.79 I . 0400 10.35 1.0465 12.04 1.0530 13-73 ' 1.0595 iS-42 1 .0660 17,12 1.072s 18.82 1 .0401 10.37 1 .0466 12.06 1.0531 13-75 1.0596 15-45 I .0661 17. 14 I .0726 18.84 I .0402 10.40 I .0467 12.09 1.0532 13-78 1.0S97 15-48 1 .0662 17.17 1.0727 18.87 I .0403 10.43 1 .0468 12.12 1.0533 13-81 1.0598 15-50 I .0663 17 . 20 1.0728 18.90 I .0404 10.45 1.0469 12.14 1.0534 13-83 I.OS99 15-53 I .0664 17.22 1 .0729 18.92 I .0405 10 .48 I .0470 12.17 I. 0535 13.86 I .0600 15-55 I .0665 17-25 1.0730 18.05 1 . 0406 10.51 I. 0471 12.19 1-0536 I 3 . 89 1 .0601 15-58 1 .0666 17-27 1.0731 18.97 I .0407 10.53 1.0472 12.22 I-OS37 13-91 1 . 0602 15-61 1 .0667 17-30 1.0732 19. 00^ I .0408 10.56 1.0473 12.25 1-0538 13-94 1 .0603 15.63 1.0668 17.33 1.0733 19.03 I .0409 10.58 1.0474 12.27 1-0539 13-96 1 .0604 15-66 1 . 0669 17.35 1.0734 19-05 I .0410 10. 61 1-0475 '12.30 I .0540 13-99 r.o6os 15-68 ' I .0670 17-38 1.073s 19 .08 I .0411 10.63 1 .0476 12.32 1 -0541 14.01 I .0606 15-71 1 .0671 17.41 1.0736 19. 10 I .041 2 10. 66 1.0477 12.35 I -0542 14.04 1 .0607 15-74 1 .0672 17-43 1.0737 19-13 I .0413 10.69 1 .0478 12.38 1-0543 14.07 1 .0608 15-76 1.0673 17.46 1.0738 19.16 I .0414 10. 71 1.0479 12.40 1-0544 14.09 1 .0609 15-79 1.0674 17-48 1-0739 19. 18 I .0415 10.74 1 .0480 12.43 I -0545 14.12 I .0610 i5-8i I -0675 17.51 1.0740 19.21 I .0416 10. 76 I .0481 12.45 1.0546 14-14 1 .061 1 15-84 I .0676 17-54 1-0741 19.23 I .0417 10.79 I .0482 12.48 I -0547 14-17 I .0612 15-87 1.0677 17-56 1.0742 19. 26 1 .0418 10.82 1.0483 12.51 I .0548 14. 20 I .0613 15.89 1.0678 17-59 1.0743 19-29 1 .0419 10.84 1 . 0484 12.53 I.OS49 14. 22 I .0614 15.92 I .0679 17.62 1-0744 19-31 1 .0420 10.87 1.048s 12.56 1.0550 14-25 1.061s 15.94 I .0680 17.64 1-0745 19- 34 1 .0421 10 .90 1 .0486 12.58 1. 0551 14. 28 1 .0616 15.97 "I.0681 17.67 I .0746 19-37 1 .0422 10.92 1 .0487 12.61 1.0552 14-30 1 .0617 16.00 j 1.0682 17.69 1.0747 19-39 1 .0423 10.95 1.0488 12.64 1 .0553 14-33 1.0618 16.02 ' 1.0683 17.72 1.0748 19-42 1 .0424 10.97 I .0489 12.66 1.0554 14-35 1 .0619 16. OS 1 .0684 17.75 1-0749 19.44 I .0425 11 .00 I .0490 12.69 1.0555 14.38 1 .0620 16.07 1 1.0685 17.77 1.0750 19-47 I .0426 11 .03 I .0491 12.71 1.0556 14.41 1 .0621 16.10 I 1.0686 17.80 1.0751 19.50 1 .0427 11 .05 I .0492 12.74 I.OS57 14.43 1 .0622 16.13 : 1.0687 17.83 1.0752 19-52 I .0428 11.08 I -0493 12.77 1.0558 14.46 1.0623 16.15 1.0688 17.8'? 1-0753 19- 55 I .0429 11 . 10 1.0494 12.79 I.05S9 14.48 1 .0624 16.18 1 .0689 17.88 1-0754 19.58 I .0430 11.13 1.0495 12.82 1 .0560 14.51 1 .0625 16. 21 1 .0690 17-90 1-0755 19.6c I .0431 11.15 I .0496 12.84 I. 0561 14-54 1 .0626 16.23 1 . 0691 17-93 1-0756 19.63 I .0432 11.18 I -0497 12.87 1 .0562 14.56 1 .0027 16.26 1 .0692 17-95 1-0757 19.65 I .0433 11 . 21 1 .0498 12.90 1.0563 14-59 1.0628 16.28 1 .0693 17-98 1.0758 19.68 I 0434 11.23 1.0499 12.92 1.0564 14.61 1 .0629 16.31 1 .0694 18.01 1-0759 19.71 I .043s II . 26 I .0500 12.95 1.056s 14.64 1 .0630 16.33 1 .0695 18.03 1 .0760 19-73 I .0436 11.28 1.0501 12.97 1.0566 14.67 1 .0631 16.36 1 .0696 18.06 1 .0761 19.76 I .0437 11 .yi 1.0502 13.00 1.0567 14.69 1 .0632 16.39 1 .0697 18.08 1 .0762 19-79 1 . 0438 II • 34 1 -0503 13.03 1.0568 14.72 1.0633 16.41 1 .0698 18.11 I -0763 1981 1.0439 II .36 1 .0504 .13.05 1 .0569 14.74 I .0634 16.44 1 .0699 18.14 I .0764 19-84 I .0440 II -39 I. 050s 13-08 1.0570 14.77 1.0635 16.47 I .0700 18.16 1.0765 19.86 I . 0441 11 .42 I . 0506 13-10 1.0571 14.80 ] 1 .0636 16.49 1 .0701 18.19 I .0766 19.89 I .0442 11.44 1-0507 13.13 1.0572 14.82 1 1.0637 16.52 I .0702 18.22 1.0767 19-92 I .0443 II -47 1 .0508 13.16 1.0573 14.85 1.0638 16.54 1-0703 18.24 1.0768 19.94 1 . 0444 11.49 1.0509 13.18 1.0574 14.87 I .0639 16.57 1 .0704 18.27 1 .0769 19.97 1.044s 11.52 1 .0510 13-21 1.0575 14.90 I . 0640 16.60 1.0705 18.30 1.0770 20.00 I .0446 ii-SS 1 .0511 13-23 1.0576 14.93 1 .0641 16.62 I .0706 18.32 1.0771 20. 02 ' I 0447 11-57 1 .0512 13-26 1-0577 14.95 I .0642 16.65 1 .0707 18.35 1.0772 20.05 I .0448 1 1 . 60 I .0513 13.29 1.0578 14.98 1 .0643 16.68 1 . 0708 18.37 1-0773 20.07 1.0449 11 .62 1.0514 13.31 1.0579 15.00 1 . 0644 16. 70 I .0709 18.40 1-0774 20. 10 ' 1.0450 II .65 1-051S 13.34 1.0580 15.03 I .064s 16.73 I .0710 18.43 1-0775 20. 12 1 .0451 11.68 I .0516 13.36 1.0581 15.06 1 .0646 16.75 1 .0711 18.45 1.0776 20. IS 1 0452 11.70 1.0517 13.39 1.0582 15.08 1 .0647' 16.78 1 . 071 2 18.48 1.0777 20.18 I .0453 11-73 1.0518 13-42 1.0583 15.11 1 .0648 16.80 1-0713 18.50 1.077S 20.20 1.0454 11-75' 1.0519 13.44 1 .0584 15.14 I .0649 16.83 1.0714 18.53 1 1-0779 20.23 ALCOHOLIC BEVERAGES. EXTRACT IN WINE— (C««//«Me«f). 699- Specific Ex- Specific Ex- Specific Ex- Specific Ex- i Specific Ex- Specific Ex- Gravity. tract. Gravity, tract. Gravity- tract. Gravity tract. Gravity tract. Gravity. 1.1105 tract. 1 .0780 20 . 26 I .0845 1 21 .96 I .09x0 23.67 1-0975 25.38 1 1 . 1040 27.09 28.81 1 .0781 20. 28 j I .0846 21.99 1 .0911 23.70 1 .0976 25.41 j 1.1041 27 . 12 1 . 1 106 28.83 1 .0782 20. 31 1.0847 22.02 I .091 2 23.72 1.0977 25-43 ' 1 . 1042 27.15 1 . 1107 28. 86 1.0783 20.34 1.0848 22.04 1-0913 23.75 1 .0978 25.46 I. 1043 27.17 1 . 1108 28. 88 I .0784 20.36 1 .0849 22.07 1 .0914 23.77 1.0979 25.49 I . 1044 27 . 20 I . 1109 28.91 1.078s 20.39 I .0850 22.09 1.091S 23.80 I .0980 25.51 I. 104s 27. 22 I . IIIO 28.94 1.0786 20 .41 I .0851 22.12 I -0916 23.83 I .0981 25.54 I . 1046 27.25 1 . iiii 28.96 1.0787 20.44 1.0852 22.15 1.0917 23.85 I .09S2 25-56 1.1047 27.27 1.1112 28.99 1.0788 20.47 1.0853 22. 17 I .0918 23.88 I -0983 25.59 1 . 1048 27.30 1 .1113 29 .02 1 .0789 20.49 1 1.0854 22. 20 1 .0919 23.91 I .0984 25.62 I. 1049 27-33 1 . 1114 29.04 1 .0790 20.52 ,1.0855 22. 22 1 .0920 23.93 I .0985 2S.64 1.1050 27.3s 1.1115 29.07 1.0791 20.55 : 1.0856 22.25 I .0921 23.96 I .09S6 25.67 1.1051 27-38 I . II 16 29.09 1 .0792 20.57 1.0857 22.28 1 .0922 23.99 I .0987 25.70 1-1052 27.41 1 . 1117 29. 12 1 .0793 20. 60 1.0858 22.30 1-0923 24.01 1.0988 25.72 I-I0S3 27-43 1.1118 291s 1.0794 20.62 1.0859 22.33 1 .0924 24.04 I .0989 25-75 I. 1054 27.46 1 . 1119 29.17 1.0795 20. 65 1 .0860 22.36 1-0925 24.07 I .0990 25-78 I-1055 27.49 1 . 1120 29. 20 1 .0796 20.68 i.o86i 22.38 1 .0926 24.09 I .0991 25.80 1 . 1056 27.51 1 .1121 29.23 1.0797 20. 70 1.0862 22.41 1-0927 24. 12 I .0992 25.83 1.1057 27.54 1.1122 29.2s 1 .0798 20.73 1.0863 22.43 I -0928 24.14 1.0993 25.85 I. 1058 27.57 I. 1123 29 . 28- 1.0799 29.7s 1 .0864 22.46 1 .0929 24.17 1.0994 25.88 1.1059 27.59 1 . 1 1 24 29-31 1 . 0800 20.78 1.086s 22.49 1-0930 24. 20 1-0995 25-91 I . 1060 27.62 I.II2S 29-33 1 .0801 20.81 1.0866 22. SI 1-0931 24. 22 I .0996 25-93 I . 1061 27.65 I . 1126 29-36 1 .0802 20.83 1.0867 22.54 1-0932 24-25 1.0997 25-96 1 . 1062 27.67 1 . II27 29-39- 1 .0803 20.86 1.0868 22.57 1-0933 24.27 I .0998 25-99 1-1063 27.70 1. 1 128 29-41 1 .0804 20.89 1 .0869 22.59 1-0934 24.30 1.0999 26.01 1 - 1064 27.72 1 . II29 29.44 1 .0805 20.91 I .0870 22 . 62 I-093S 24-33 1 . 1000 26.04 I-1065 27.7s I.II30 29.47 1 .0806 20.94 1 .0871 22.65 1-0936 24-35 I . lOOI 26.06 I . 1066 27-78 I .1131 29.49. 1 .0807 20.96 1 .0872 22.67 1-0937 24-38 I .1002 26.09 I . 1067 27.80 1.1132 29-52 1 .0808 20.99 1.0873 22. 70 1-0938 24-41 1.1003 26. 12 I. 1068 27-83 1.1133 29.54- 1 . 0809 21.02 1.0874 22.72 1-0939 24-43 I . 1004 26. 14 1 . 1069 27.86 1.1134 29-57 1 .0810 21 .04 1.087s 22.7s I - 0940 24.46 1 . 1005 26. 17 1 . 1070 27.88 1.1135 29.60- 1 .081 1 21.07 1.0876 22.78 1-0941 24.49 1 . 1006 26. 20 1 . 1071 27.96 1.1136 29.62- 1 .0812 21 . 10 1.0877 22.80 1 .0942 24.51 1 . 1007 26. 22 I . 1072 27-93 1.1137 29.6s I. 0813 21.12 1.0878 22.83 1-0943 24.54 1 . 1008 26.25 1-1073 27-96 1.1138 29.68- 1 .0814 21.15 1 1.0879 22.86 1-0944 24-57 1 . 1009 26. 27 1-1074 27-99 1.1139 29.70- I. 0815 21.17 i.o88o 22.88 1-0945 24-59 1 . 1010 26.30 1.107s 28.01 1 . 1 1 40 29-73 I. 0816 21 . 20 1.0881 22.91 I -0946 24.62 1 . lOII 26.33 I - 1076 1 28.04 1 I . 1141 29.76 1 .0817 21 .23 1 I .0882 22.93 1.0947 24.64 I . 1012 26.35 I-1077 28.07 I . 1142 29.78 I. 0818 21.2s 1! 1.0883 22 .96 1 .0948 24.67 1.1013 26.38 1 . 1078 28.09 1-1143 29.81 1 .0819 21.28 1.0884 22.99 1.0949 24-70 1 - 1014 26-41 I. 1079 28.12 1.1144 29.83 I .0820 21.31 1.088s 23.01 1 .0950 24-72 1-iois 26.43 1 . 1080 28.15 1-1145 29.86 1 .0821 21.33 1 .0886 23.04 1.0951 24-75 1 - 1016 26.46 1 . 1081 28.17 1 . 1146 29.89 I .0822 21 .36 1.0887 23.07 1 .0952 24.78 1 . 1017 26.49 1 . 1082 28.20 1.1147 29.91 1.0823 21.38 1 . 0888 23.09 1.0953 24.80 1 . ioi8 26.51. 1.1083 28. 22 1 . 1148 29.94 I .0824 21 .41 1.0889 23.12 1.0954 24-83 i'. 1019 26.54 1 . 1084 28.2s I. I 149 29.96 1 .0821; 21.44 1 .0890 23.14 I. 0955 24-85 1 . 1020 26.56 1.1085 28.28 I . 1150 29-99 1.0826 21 .46 1.0891 23-17 1.0956 24.88 1 . 1021 26.59 I. 1086 28.30 I .1151 30.02: I .0827 21.49 I .0892 23.20 I. 0957 24.91 1 . 1022 26.62 I. 1087 28.33 1.1152 30.04. 1.0828 21.52 1-0893 23.22 I .0958 24.93 1. 1023 26. 64 1.1088 28.36 1.1153 30.07 I .0829 21.54 1 .0894 23.25 1-0959 24.96 1 . 1024 26.67 1 . 1089 28.38 1-1154 30. 10 I .0830 21.57 1 .089s 23.28 I .0960 24.99 I . I02S 26.70 1 . 1090 28.41 1-1155 30.13 1.0831 21.59 ' I .0896 23.30 I .0961 25.01 1 . 1026 26. 72 1 . 1091 28.43 1-1156 30.15 I .0832 21 .62 I .0897 23.33 1 .0962 25-04 1 . 1027 26.75 1 . 1092 28.46 1-1157 30.18 1.0833 21. 6s 1.0898 23.35 1.0963 25-07 1 . 1028 26.78 I. 1093 28.49 1.1158 30-21 1.0834 21 .67 I .0899 23.38 1 .0964 25-09 1 . 1029 26.80 1 . 1094 28.51 1-1159 30-23 1 .0835 21 .70 1 .0900 23.41 1.0965 25-12 1 . 1030 26.83 1.109s 28.54 1.0836 21.73 1 .0901 23.43 1 .0966 25-14 I.I03I 26.85 1 .1096 28.57 1.0837 21.7s 1 .0902 23.46 I .0967 25-17 1 .1032 26.88 1.1097 28.59 1.0838 21.78 1 .0903 23.49 I .0968 25-20 I. 1033 26.91 1 .1098 28.62 I .0839 21.80 I .0904 23.51 I .0969 25 . 22 I. 1034 26.93 1 . 1099 28.65 I .0840 21.83 1 .0905 23.54 1 .0970 25.25 I -1035 26.96 1 . IIOO 28.67 1 .0841 21.86 1 .0906 23.57 1.0971 25.28 1 .1036 26 . 99 I . 1101 28.70 I .0842 21.88 I .0907 23-59 1.0972 25.30 1.1037 27 .01 1 . 1102 28.73 1.0843 21 .91 I .0908 23-62 1.0673 25-33 I. 1038 27-04 I . 1103 28.75 1 .0844 21.94 I .0909 23-65 1.0974 25.36 1 1.1039 27.07 I . II04 28.78 700 FOOD INSPECTION AND AN/rLYSIS. Fig. 114. — A.pparatus for Determining Volatile Acids in Wine. Fig. 115.— Hort vet's Apparatus for Determining the Volatile Acids in Wine ALCOHOLIC BEVERAGES. 701 as an indicator. Each cubic centimeter of tenth-normal alkali is equiv- alent to 0.006 gram acetic acid. Hortvet Meihod*—The apparatus (Fig. 115) consists of a 300 cc. flask into the neck of which is fitted a 200-cc. cylindrical flask, with a steam tube, a bulb-trap leading to a condenser, and a stop-cock funnel. The procedure is as follows: Pour 150 cc. of recently boiled water into the larger flask, attach the smaller flask by means of a section of rubber tubing, run in 10 cc. of wine (previously freed from carbonic acid), close the stop-cock and boil. In extreme cases add to the wine a small piece of paraffin to prevent foaming. When the water has boiled a moment, close the tube at the side of the larger flask and distil until 70 cc. of distillate have passed over. Transfer to a beaker, without discontinuing the distillation, and titrate, using phenolphthalein as indicator. Continue the distillation until the last 10 cc. portion requires not more than one drop of tenth-normal alkali for neutralization. Usually 80 or 90 cc. of distillate includes practically all of the volatile acids. Cool the apparatus, thus allowing the wine residue to be drawn back into the lower flask, rinse with boiled water, and reserve the total liquid for determination of non-volatile acids. Non-volatile Acids. — These may be determined by difference, cal- culating the vola ile acids for purposes of subtraction in terms of tar- taric or other acid in which the total acidity is expressed. Non-volatile acid may be directly determined by evaporating to dryness a measured portion of the liquor, boiling the residue with water, and titrating the solution wiJi the standard alkali. Detection of Free Tartaric Acid. — Nessler's Method. — Some pow- dered cream of tartar is added to a portion of the wine in a corked flask, which is shaken from time to time, and the liquid finally filtered. To the filtrate is added a little 20% potassium acetate solution. If free tartaric acid is present, on stirring and especially after standing for some time, there will be a precipitate of cream of tartar. Determination of Tartaric Acid, Total, Free, and Combined. — Pro- visional methods A. O. A. C.f Tolal Tartaric Acid. — To 100 cc. of wine add 2 cc. of glacial acetic acid, 3 drops of a 20% solution of potassium acetate, and 15 grams of powdered potassium chloride, and stir to hasten solution. Add 15 cc. of 95% alcohol (specific gravity 0.81) and "rub the side of the beaker vigorously wi h a glass rod for about one minute to start crystallization. * Jour. Ind. Eng. Chem., r, 1909, p. 31 t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 87. 70 2 FOOD INSPECTION AND ANALYSIS. Let Stand at least fifteen hours at room temperature ; decant the liquid from the separated acid potassium tartrate as rapidly as possible (using vacuum) through a Gooch crucible prepared with a very thin film of asbestos, transferring no more of the precipitate to the crucible than necessary. Wash the precipitate and filter three times with a small amount of a mixture of 15 grams potassium chloride, 20 cc. of 95% alco hoi (specific gravity 0.81), and 100 cc. water, using not more than 20 cc. of the wash solution in all. Transfer the asbestos film and precipitate to the beaker in which the precipitation took place, w^ash out the Gooch crucible with hot water, add about 50 cc. of hot water, heat to boiling, and titrate the hot solution with decinormal sodium hydroxide, using delicate litmus tincture or litmus paper as indicator. Increase the number of cubic centimeters of decinormal alkali employed by 1.5 on account of the solubility of the precipitate. This figure multiplied by 0.015 gives the amount of total tartaric acid in grams per 100 cc. Cream of Tartar.— Ignite the residue obtained from the evaporation of 50 cc. of wine as directed under the determination of ash. Exhaust the ash with hot water, add to the filtrate 25 cc. of decinormal hydro- chloric acid, heat to incipient boiling, and titrate with decinormal alkali solution, using litmus as indicator. Deduct from 25 cc. the number of cubic centimeters of decinormal alkali employed, and multiply the remainder by 0.0188 for potassium bitartrate expressed in grams. Free Tartaric Acid. — Add 25 cc. of decinormal hydrochloric acid to the ash of 50 cc. of wine, heat to incipient boiling, and titrate with deci- normal sodium hydroxide, using litmus as indicator. Deduct the number of cubic centimeters of alkali employed from 25, and multiply the remainder by 0.0075 to obtain the amount of tartaric acid necessary to combine with all the ash (considering it to consist entirely of potash). Deduct the figure so obtained from the total tartaric acid for the free: tartaric acid. Determination of Free and Combined Malic Acid in Cider and Wine.. —Evaporate 100 cc. of the sample on the water-bath to half its volume,, cool, and treat first with 10 cc. of 10% calcium chloride solution, and then with ammonia to strong alkaline reaction. Let stand for an hour and filter. This removes the tartaric acid. Concentrate the filtrate by evaporation on the water-bath to 25 cc, add 75 cc. of 95% alcohol, heat to the boiling-point, and fiher. Wash the residue with a mixture of 3 parts 95% alcohol and i part water, dry, and burn to an ash. Add. 25 cc. of tenth-normal hydrochloric acid to the ash, dilute with water^ ALCOHOLIC BEVERAGES. 703 heat to boiling, and titrate with tenth-normal sodium hydroxide, using phenolphthalein as an indicator. Multiply the difference between 25 and the number of cubic centimeters required to neutralize by 0.0067 for the grams of malic acid. Polarization. — Treat a measured amount of wine or cider with one- tenth of its volume of lead subacetate, filter and polarize the filtrate in the 200 mm. tube. The reading is increased by 10% for the true direct polarization. If the reducing sugars are also to be determined, the same solutions may be used for both the polarization and the reducing sugars as follows : Exactly neutralize with sodium hydroxide solution 200 cc. of the wine, using litmus paper as an indicator, and evaporate on the water-bath to about one-fourth its original volume. Wash with water into a 200 cc. flask, add enough normal lead acetate solution to clarify, and make up with water to the mark. Filter and to the filtrate add powdered sodium sulphate or carbonate sufficient to precipitate the lead, again filter and polarize before and after inversion (p. 588). Determination of Reducing Sugars. — Determine reducing sugars in portions of the wine treated as described in the preceding section, after dilution so as not to contain above 0.5% of sugar for the Defren and the Munson and Walker methods or above 1% of sugar for the Allihn method. One may assume 2% as the sugar-free extract of wine, the number of volumes of water to be added to the filtrate being determined by the dif- ference between 2 and the total extract as determined. Determination of Glycerin. — In Dry Wines. — Evaporate 100 cc. of the wine in a porcelain dish on the water-bath to about 10 cc, add about 5 grams of fine sand and from 3 to 4 cc. of milk of lime (containing about 15% of calcium oxide) for each gram of extract present and evaporate nearly to dryness. Treat the moist residue with 50 cc. of 95% (by vol.) alcohol, remove the substance adhering to the sides of the dish with a spatula, and rub the whole mass .to a paste. Heat .on a water-bath, with constant stirring, to incipient boiling and decant through a filter into a small flask. Wash by decantation with 10 cc. portions of hot 95% alcohol until the filtrate amounts to about 150 cc. Evaporate the filtrate to a sirup on a hot, but not boiling, water-bath, transfer to a small glass- stoppered graduated cylinder with 20 cc. of absolute alcohol, and add 3 portions of 10 cc. each of absolute ether, shaking throughly after each addition. Let stand until clear, then pour off through a filter and wash 704 FOOD INSPECTION AND ANALYSIS. the cylinder with a mixture of absolute alcohol and absolute ether (i : 1.5), pouring the wash Hquor also through the filter. Evaporate the filtrate to a sirup, dry for one hour in a boiling water oven, weigh, ignite, and weigh again. The loss on ignition gives the weight of glycerin. In Sweet Wmes. — If the extract exceeds 5% heat 100 cc. to boiling in a flask and treat with successive small portions of milk of lime until the color becomes at first darker and then lighter. When cool add 200 cc. of 95% alcohol, allow the precipitate to subside, filter, and wash with 95% alcohol. With the filtrate thus obtained proceed as directed for dry wines Determination of Potassium Sulphate. — Acidify 100 cc. of the sample with hydrochloric acid, heat to boiling, and add an excess of barium chloride solution. Filter, wash, dry, ignite, and weigh as barium sul- phate, calculating the equivalent of potassium sulphate. The presence of the latter in excess of 0.06 gram per 100 cc. indicates plastering. Determination of Tannin. — An approximate method of determining tannin is that of Nessler and Barth. 12 cc. of wine are treated with 30 cc. of alcohol and filtered. 35 cc. of the filtrate, which corresponds to ID cc. of the wine, is evaporated to about 6 cc. and transferred to a lo-cc. graduated centrifuge tube. A few drops of 40% sodium acetate are then added, and a slight excess of 10% ferric chloride. The tube is corked, gently agitated, and allowed to stand for twenty-four hours. The volume of the precipitate is then measured, each cubic centimeter being equivalent to 0.033% of tannin in the wine. Foreign Coloring Matters in Wine. — A wide variety of artificial colors have been found in red wine. Those most commonly employed at present are cochineal, fuchsin, and acid fuchsin. The Pharmacopoeia prescribes the following color tests: If 2 cc. of red wine be mixed in a test-tube with 2 drops of chloroform and 4 cc. of normal potassium hydroxide, and the mixture carefully heated, the disagreeable odor of isonitril should not become preceptible (absence of various anilin colors). If 50 cc. of red wine be treated with a slight excess of ammonia water, the liquid should acquire a green or brownish-green color; if it be then well shaken with 25 cc. of ether, the greater portion of the ethereal layer removed and evaporated in a porcelain capsule with an excess of acetic acid and a few fibers of uncolored silk, the latter should not acquire a crimson or violet color (absence of fuchsin). If 25 cc. of red wine heated to about 45° C. be well agitated with 25 grams of manganese dioxide, the liquid filtered off and acidulated with ALCOHOLIC BEyERAGES. 705 hydrochloric acid, it should not acquire a red color (absence of sulpho- fuchsin). Dupre's Method 0} Detection.* — Small cubes of jelly measuring about 2 cm. in thickness are prepared as follows: Dissolve i part of pure gelatin in 10 parts boiling water and pour upon a plate to harden. This is then cut into cubes of the above size by a sharp knife. Wlien a wine is suspected of containing foreign color, one of the cubes is immersed therein and allowed to remain for twenty-four hours, after which it is removed, washed slightly in cold water, and cut through with a knife. If the color is a natural one, it will lightly tinge the outer surface of the cv.be, but will not permeate far below the surface, so that the inner por- tion of the cross-section will be largely free from color. Nearly all foreign coloring matters used in wine, such as most coal-tar dyes, cochineal, Brazil wood, logwood, etc., will be found to deeply permeate the jelly cube often to ihe center. Information as to the nature of the color may sometimes be gained by immersing the dyed jelly cube in weak ammonia. If the color be rosanilin, the cube is decolorized, if cochineal, a purple coloration will result, and if logwood, a brown tinge. Cazeneuve's Methods for Detecting Colors in Wine. — While by no means complete, the following method of Cazeneuve as condensed and arranged by Gautier (La Sophistication des Vins) will often be found helpful. If other colors than these are evidently present, tests should be made as indicated in Chapter XVII. Cazeneuve employs the fol- lowing reagents: (i) Yellow oxide of mercury, finely pulverized. (2) Lead hydrate, freshly precipitated, well washed, suspended in about twice its volume of water; to be kept in a stoppered bottle; should be renewed after several days' use. (3) Gelatinous ferric hydrate, well washed from ammonia, suspended in about twice its volume of water. (4) Manganese dioxide, pulverized. (5) Concentrated, chemically pure sulphuric acid. (6) White wool. (7) Stannous hydrate, freshly precipitated, well washed, suspended in water, and kept from exposure to light and air. (8) Collodion silk, the artificial silk produced from nitro-celluloae. This fiber has a special affinity for basic dyes. * Jour. Chem. Soc, 37, p. 572. 7o6 FOOD INSPECTION AND ANALYSIS. To lo cc. of the wine are added 0.2 gram finely powdered yellow oxide of mercury. Boil and pour upon a double filter. Filtrate colored either before or after acidifying. PL P' &:2 o' E" 3 Q Filtrate colored yellow. 10 cc. of the wine are warmed with 2 grams lead hydrate. Filter. Filti'ate colored yellow. A large excess of lead hydrate is added and the liquid is boiled. Filtrate colored red. 10 cc. of the wine are treated with 2 grams lead hydrate and filtered. Filtrate col- orless a f t e I acidifying. ALCOHOLIC BEyERAGES. 707 MALT LIQUORS. BEER. In its widest sense beer may be defined as the product of fermentation of an infusion of almost any farinaceous grain with various bitter extract- ives, but unless otherwise qualitied it should be strictly applied to the beverage resulting from the fermentation of malted barley and hops. In the manufacture of beer two distinct processes are employed, viz., malting or sprouting the grain, and brewing. Many brewers do noth- ing but the latter, buying their malt already prepared. Malting.— For the preparation of malt, the barley is steeped in water for several days, after which the water is drained off and the moist grain is "couched," or piled in heaps, on a cement floor, where it undergoes a spontaneous heating process, during which it germinates, forming the ferment diastase. When the maximum amount of diastase has been produced, indicated by the length of growth of the sprout, or "acrospire " within the grain, the germination is checked by spreading the grain in layers over a perforated iron floor, and finally subjecting it to artificial heat. The character of the malt and of the beer produced from it depends largely on the heat at which the "green" malt is kiln dried. If dried between 32° and 37° C. it forms pale malt, which produces the lightest grades of beer. Most beer is made from malt dried at higher tem- peratures, say from 38° to 50°, the depth of color of the liquor var^'ing with the heat to which the malt has been subjected, while the color of the malt varies from the "pale" through the "amber" to "brown," or even black. The darkest grades are sometimes dried at temperatures over 100° C, even to the point where the starch becomes caramelized. A more modem method consists in the so-called pneumatic malting, wherein the whole operation is conducted in a large rotating drum, which holds the grain, and in which the temperature and moisture at different stages is carefully controlled by the admission to the interior of the drum of moisture-laden or dry air, heated to the required degree. The chief object of malting is the production of diastase, which by its subsequent action on the starch converts it into the fermentable sugars maltose and dextrin. Malt contains much more diastase than is necessary to convert the starch simply contained therein to maltose, and is capable of acting on the starch of a considerable quantity of raw grain, such as com or rice, when mixed with it. This practice of using other grains than malt is prohibited in some localities, such as Bavaria. 7o8 FOOD INSPECTION AND ANALYSIS. Brewing. — The malt, or mixture of malt and raw grain, is first crushed! and "mashed" by stirring with water in tubs at 50° to 60° C, finally heating to 70°. During this process the conversion of the starch to mal- tose and dextrin takes place. The resulting Hquor is known as ' ' wort," containing, besides maltose and dextrin, peptones and amides. The clear wort is then drawn off from the residue, and boiled to concentrate the product and to sterilize it, after which hops (the female flower of the Humulus lupulus) are added and the boiling continued. Hops contain resins, bitter principles, tannic acid, and a pecuKar essential oil, all of which are to some extent imparted to the wort. After cooling and settling, the clear wort is run into fermenting-vats, where selected yeast,, usually saccharomyces cerevisice, is added, and the alcoholic fermentation allowed to proceed. The temperature greatly affects the character of the fermentation. If kept between 5° and 8° C, a slow fermentation proceeds, known as bottom fermentation, during which the yeast settles out at the bottom. This is much more easily controlled than the quick or top fermentation, which takes place at from 15° to 18°, much of the yeast in the latter case being carried to the surface, from which it is finally removed by skimming. In either case the yeast feeds upon the albuminous matter present. At the proper stage the beer is drawn off from the larger portion of the yeast, and run into casks, or tuns, in which an after-fermentation proceeds. The beer is finally clarified by treatment with gelatin or beech shavings 01 chips, to which the floating yeast-cells and other impurities attach themselves. It is finally stored in barrels coated with brewers' pitch, or pasteurized at 60° C. and bottled. Varieties of Beer. — Formerly the division of beers into "lager," "schenk," and "bock" was made by reason of the fact that beer had to- be brewed imder certain climatic conditions and at certain seasons only- Now, with improved means for artificial refrigeration, and with better methods controlling all stages of the process, these distinctions are less marked. Lager Beer (from lager, a storehouse) is a term originally applied to Bavarian beer, but is now given to any beer that has been stored several months. Formerly lager beer was made early in the winter, and stored in cool cellars till the following spring or summer, during nearly all of which time a slow after-fermentation took place. The best lager beers contain a low proportion of hops, and are high in extract and alcohol. Schenk Beer is a quickly fermented beer made in winter for immedi- ALCOHOLIC BEyERAGES. 70 > ate use. It is brewed in from four to six weeks and will not keep long, without souring. Bock Beer, according to older systems of nomenclature, occupied a middle place between lager and schenk, being an extra strong beer brewed for spring use and made in limited quantities, not being intended for- storage. Berlin Weiss Bier is prepared by the quick or top fermentation of a. wort consisting of a mixture of malted barley and wheat with hops. It is high in carbon dioxide, being usually bottled before the second fermen- tation has ended. Ale is virtually the English name for beer. It is usually lighter colored than lager beer, being made from pale malt by quick or top fermentation, and containing rather more hops than beer. It has a high content of sugar, due to checking fernientation at an earlier stage than in ordinary beer. Porter is a dark ale, the deep color of which should be due to the use of brown malt dried at a high temperature, but v/hich is sometimes colored by the admixture of caramel. It has a large extract, chiefly sugar. Stout is an extra-strong porter, being high both in alcohol and extract.. Composition of Beer. — Beer is a somewhat complex liquor. Besides water, alcohol, and sugar, it contains carbon dioxide, succinic acid, dex- trin, glycerin, tannic acid, the resinous bitter principles of hops, nitrog- enous bodies (chiefly peptones and amides), alkaline and lime salts (chiefly phosphates), fat (traces), acetic acid and lactic acid. The latter acid constitutes the chief fixed acid of beer. The following analyses of different varieties of beer are due to Konig;- Variety. Eg o aj vk 6 "He srin. t3 5§-a m^ -^l^ :3S 2Q 5-3 ^ CO <; C Schenk Lager Export beer. Bock Weiss bier. . roriei Ale 205 258 109 84 26 40 38 1.0114 I .0162 I. 0176 I. 0213 I. 0137 I.OIQI I.OI4I 91. II 0.197 gO.08'0.196 89.OIjO.2O9 87.87 0.234 91.630.297 88.49 O-215 89.420.201 3-365-34 ■^-70 6.38 7.21 5-34 6-59 5-65 3-93 4.40 4-69 2-73 ^.70 4-75 0.74 0.71 0.74 0-73 0.58 0.65 -95 1.62 2.62 1.07 3- 1 1 3-73 3-47 3-97 2.42 3.08 0.156 0.12 0.165 0.154 0.151 0.161 0.165 0.392 0.281 0.278 0.176 092 0.204 0.228 0.247 0.263 0.149 0.363 O. ^T 0-055. 0.077 0.074 o . o8g 0.0^4 0.093 D . 0S6 Fifteen samples of lager beer and seven samples of pale ale, bought in Massachusetts bar-rooms, representing as nearly as possible the qv.ali;:y; y 7IO FOOD INSPECTION AND ANALYSIS. of liquor sold every day to patrons by the bottle or glass, were analyzed by the Board of Health with the following results: Beer — Maximum Minimum. Mean Fale ale — Maximum Minimum. Mean Per Cent of Original Wort Extract. 18.91 7-33 15-04 15.99 10.95 13-56 Per Cent of Alcohol by Weight. 7.07 1. 10 4-45 5-^7 3-53 4-49 Per Cent of Extract. .76 .67 .92 -47 -38 ■54 Five out of the 15 beer samples and 3 out of the 7 ale samples con- tained salicylic acid. The percentage composition of the ash of German beer is thus given by Konig as the mean of 19 analyses: Ash in TOO Parts Beer. Potash. Soda. Lime. Magnesia. Iron Oxide. Phos- phoric Acid. Sul- ! phuric 1 Silica. Acid. Chlorine. 0.306 33-67 8.94 2.78 6.24 0.48 31.35 3.47 9-29 2.93 Malt and Hop Substitutes. — By reason of the fluctuation in market price of these two chief constituents of beer, it sometimes becomes a question of economy to employ cheaper substitutes wholly or in part for one or the other. There are two classes of malt substitutes, (i) those which, like com, rice, and wheat, are mixed directly with the malt before "mashing," and, like the malt, have to undergo a saccharous fermenta- tion before being acted on by yeast, and (2) such substances as cane sugar, invert sugar, commercial glucose, and dextrin, which are added to the wort at a later stage in the brewing, just before the addition of the yeast, being in condition to be readily acted on by the latter. Glucose is by far the most common malt substitute, by reason of the fact that its sugars much resemble those of malt, and are in readily ferment- able form. Diastase forms from the malt dextrin and maltose, while commercial glucose contains dextrin, maltose, and dextrose. When the price of malt is abnormally high, the addition of glucose is decidedly economical, but when ordinary conditions prevail, the cost of the two, figured with reference to their yield in alcohol and extract, is about the same. Aside from the question of economy, however, there are advantages in the use of glucose, such as diminishing the nitrogenous content of the wort without lessening the alcohol or extract yielded. / /tLCOHOLIC BEVERAGES. 711 The nitrogenous matter left after fermentation is one of the chief causes of cloudiness or turbidity in the finished product, and is some- times difficult to remove. By the use of glucose, especially in brewing clear bottled ales and sparkling pale beers, the appearance of the product is much enhanced. The temptation at times to add more glucose than is necessary to accomplish this is great. A high-grade malt may have as much as 40% of glucose added to its wort and still produce an acceptable beer. With a low-grade malt, glucose yields a very poor quality of beer. Hence the use of glucose may or may not be desirable, though it can hardly be considered unqualifiedly as an adulterant. As to the employment of hop substitutes, the question of relative price again enters in. Only when the price of hops is high is there any special inducement to use substitutes. Quassia wood, chiretta, gentian, and calumba, all of which yield bitter principles, have been used in beer, and cannot be considered detrimental to health. Allen and Chattaway have found the first two in beer examined by them.* Such poisonous substances as cocculus indicus, picric acid, and strjxhnine are alleged to have been used as hop substitutes, but there is no authentic record of any of them having been found in recent years, if at all. Adulteration of Malt Liquors and Standards of Purity. — The Joint Committee on Standards of the A. O. A. C. and the A. S. N. F. D. D. has adopted the following standards: Malt Liquor is a beverage made by the alcoholic fermentation of an infusion, in potable water, of barley malt and hops, with or without unmalted grains or decorticated and degerminated grains. Beer is a malt liquor produced by bottom fermentation, and contains in 100 cc, at 20° C, not less than 5 grams of extractive matter and 0.16 gram of ash, chiefly potassium phosphate, and not less than 2.25 grams of alcohol. Lager Beer, Stored Beer, is beer which has been stored in casks for a period of at least three months, and contains, in 100 cc, at 20° C, not less than 5 grams of extractive matters, and 0,16 gram of ash, chiefly potassium phosphate, and not less than 2.50 grams of alcohol. Malted Beer is beer made of an infusion, in potable water, of barley, malt, and hops, and contains, in 100 cc, at 20° C, not less than 5 grams of extractive matter, nor less than 0.2 gram of ash, chiefly potassium phosphate, not less than 2.25 grams of alcohol, nor less than 0.4 gram of crude protein (nitrogen X 6. 2 5). * Analyst, 12, 112. 7 2 FOOD INSPECTION AND ANALYSIS. Ale is a malt liquor produced by top fermentation, and contains, in ICO cc, at 20° C, not less than 2.75 grams of alcohol, nor less than 5 grams of extract, and not less than 0.16 gram of ash, chiefly potassium phosphate. Porter and Stout are varieties of malt liquors made in part from highly roasted malt. Non-injurious bitter principles are no doubt employed in place of hops, and unless the liquor is sold for a pure malt beer, they cannot be regarded as adulterants. The tendency to shorten the time of storage of beer, or to sell it without storing at all, lessens or does away with the after-fermentation, resulting in a lack of "life" or effervescence in the product. This is sometimes made up by the addition of sodium bicarbonate. Distinction between Malted and Non-malted Liquors. — In some states where strict prohibitory liquor laws are in force, it is illegal to sell "malt liquors," so that when convictions are obtained, it is necessary for the analyst to distinguish between liquors brewed wholly or in part from malt and those in which no malt has been used, but which were brewed entirely from malt substitutes. This distinction is not always easy to make with precision. In the absence of malt, glucose is usually the sole source of alcohol in these beverages. Parsons * has shown that the most striking points of difference between malted and non-malted liquors are in their per cent of phosphoric acid and albuminoids, and that pure malt beer or ale should contain at least 0.04% P2O5, and 0.25% albuminoids (NX6.25). A low ash and high content of sulphates in the ash are also indicative of glucose. The following analyses made by Parsons clearly show these distinctions : COMPOSITION OF SEVENTY-SIX SAMPLES OF AMERICAN MALT LIQUORS. Specific Gravity. Alcohol by Vol- ume. Extract. Albumin- oids (NX&.25) Phos- phoric Acid. Ash. Sul- phates in Ash. Free Acid. Average Maximum. . . . Minimum. . . . 1.0100 I. 0210 1.0047 5-61 7-85 0-35 4.61 7.64 3-15 0.470 0.061 0.614 O-O95 0.290 0.045 0.209 0.296 0.147 6-34 12.67 2-44 0.26 0.87 0. 10 * Jour. Am. Cham. Soc, 24, 1902, p. 11 70. ALCOHOLIC BEl^ERAGES. 713 TYPICAL ANALYSES OF BEERS APPARENTLY NOT BREWED FROM MALT. Number. Specific Alcohol Gravity, by Vol- ume. Extract. Albumin- oids (NX6.25) Phos- phoric Acid. Ash. Sul- phates. Free Acid. 1 1.0074 2 1 . 0098 3 1 . 0062 4 1.0112 5 1. 0041 1.68 2.63 2.27 2. II 1.85 2.52 3-40 2.25 3-53 ^•73 0.114 0.215 0.150 0-133 0.031 .010 .023 ■015 -015 .010 0.19 0.180 0.124 0.140 0.088 11.30 10.81 12.50 Normal The ash of the fifth sample is thus compared with that of the average beer as given by Blyth: Malt Beer " No-malt" Beer (Blyth). (Parsons). K2O 37-22 12.93 Na20 8.04 19.61 CaO 1 .93 Undetermined MgO 5-51 FeA Trace SO3 1.44 10.81 P2O5 32-09 10.71 CI 2.91 21.76 SiOj 10. 8:^2 7.50 Praservatives in Beer, — Antiseptics are frequently added to malt liquors, salicylic acid being most commonly used. Fluorides of ammo- nium and sodium have been found in American beer. Other preserva- tives to be looked for are benzoic acid and sulphites. Beer casks are frequently "sulphured" or fumed with a solution of calcium bisulphite, so that the beer may derive its content of sulphites from this source. In cases of police seizure of beer sold in bulk or in opened bottles for the purpose of ascertaining whether or not their alcoholic content exceeds certain limits fixed by law, a httle formalin had best be added as soon as possible after the seizure to prevent further fermentation. This is espe- cially desirable in cases where there is likely to be some delay in making the analysis, so as to forestall any claim on the part of the defendant of additional alcohol being formed after the seizure. From 6 to 8 drops of a 40% solution of formaldehyde to a quart of beer is sufficient, and this quantity will not appreciably aflfect the analysis. Arsenic in Beer. — In 1900 a very disastrous epidemic of arsenical poisoning occurred in Manchester^ England, involving several thousand cases, many of which were fatal. The arsenic was traced to sulphuric 714 FOOD INSPECTION AND ANALYSIS. acid, which entered into the manufacture of commercial glucose used in the beer, the acid found so highly arsenical being made from a certain variety of Swedish pyrites, which was found to be abnormally high in arsenic. There appeared to be no doubt whatever that the beer was the sole cause of the trouble. Wliile the presence of arsenic was in this case accidental, carelessness was shown on the part of those having to do with the purity of the materials entering into the composition of the beer. Fortunately no other instances are on record of arsenical poisoning from malted liquors. A large number of samples of American beer have been examined in the laboratory of the Food and Drug Department of the Massachusetts State Board of Health, and only insignificant traces of arsenic have in any case been found. Temperance Beers and Ales. — Many varieties of these so-called tem- perance drinks are home-made, as well as sold on the market. They are usually slightly fermented infusions of various roots and herbs, including ginger or sassafras, with molasses or sugar and yeast, and more often contain less than i% of alcohol by volume. Among them are included spruce beer, and the various root beers, such as ginger beer and ginger ale. The latter beverages are generally carbonated. Numerous brands of bottled beer are manufactured, which contain virtually the same body and characteristic flavor as lager beer, but not the alcohol. Indeed the com- position of many of these beverages is identical with that of lager beer,. excepting in alcoholic content, being made by substantially the same process and out of the same ingredients, but with the alcohol finally removed by steaming, so that the liquor comes within the limits of a temperance beverage. Of this class is Uno beer, which ranges from 0.6 to 0.9 per cent in alcohol. METHODS OF ANALYSIS OF MALT LIQUORS.* Preparation of Sample. — Transfer the contents of the bottle or bottles to a large flask and shake vigorously to hasten the escape of carbon dioxide, care being taken that the liquor is not below 15° C, smce below this temperature the carbon dioxide is retained by the beer and is liable to form bubbles in the pycnometer. Specific Gravity. — See page 657. Ash. — Determine in 25 cc. by evaporation and ignition at dull redness. * Barnard, U. S. Dept. of Agric, Bur. of Chem., Circ. S3- A. O. A. C. Methods, ibid.^ Bui. 107 (rev.), p. 90. ALCOHOLIC BEyERAGES. 7iS Determination of Alcohol. — From the Specific Gravity of the Dis- tillate. — Proceed as described on p. 658, employing 100 cc. of the liquor, and determining the specific gravity at 15.5° C. If the liquor is markedly acid, add o.i to 0.2 gram of precipitated calcium carbonate previous to distillation. From the Refraction of the Distillate. — Prepare the distillate as described on p. 658, except that it is made up to the mark at 17.5° C. Determine the refraction at 17.5° C. by nieans of the immersion refrac- tometer, and calculate the alcohol by the table of Ackermann and Stein- mann below. ACKERMANN AND STEINMANN'S TABLE FOR OBTAINING THE PER- CENTAGE OF ALCOHOL IN THE DISTILLATE OF BEER FROM THE IMMERSION REFRACTOMETER READINGS.* u u i-. (U . 0.5 ^1" u . 0.5 •3 -So •si" O.S ■oi" 01 C M O.S -oi" rt a ^ j- -S75 h ta g ^ 3 V- ni S ■*=! " ii •='0 !^ s s -c l^ o>CU 8^tS z>^ •Sc^ S^o! 8^^ o>Ph 2^^: e< < < ti < < p^ < < Pi < < 15.0 0.00 0.00 17.2 1.38 1-74 19.4 2.74 3-46 21.6 4.02 5.06 15-1 0.06 0.08 17-3 1-44 1.82 19-5 2.80 3-53 21.7 4 07 5-13 15.2 0-13 0.16 17-4 I-51 1.90 19.6 2.86 3.61 21.8 4 13 5.20 15-3 O.IQ 0.24 17-S 1-57 1.98 19.7 2.91 3-68 21.9 4 18 5.26 15.4 0.25 0.32 17.6 1.63 2.05 19.8 2-97 3-75 22.0 4 22 5-32 15-5 0.32 0.40 17.7 1.68 2.12 19.9 3-04 3-83 *22.I 4 28 5-39 15.6 0.38 0.48 17-8 1-74 2. 20 20.0 3.10 3-90 22.2 4 33 5-46 15-7 0.44 0.56 17.9 1. 81 2.28 20.1 3-15 3-97 22.3 4 39 5-53 15.8 0.50 0.64 18.0 1.87 2.36 20.2 3.20 4.04 22.4 4 44 5-59 15-9 0-57 0.72 18. 1 1-93 2-44 20.3 3.26 4. II 22.5 4 49 5-65 16.0 0.64 0.80 18.2 2.00 2.52 20.4 2,-Z?, 4-19 22.6 4 54 5-72 16. 1 0.70 0.88 18.3 2.06 2.60 20.5 3-38 4.26 22.7 4 59 5-78 16.2 0.77 0.96 18.4 2.13 2.68 20.6 3-43 4-33 22.8 4 64 5-85 16.3 0.83 1.04 18.5 2.19 2.76 20.7 3-50 4-41 22.9 4 70 5-92 16.4 0.8S I . 12 18.6 2.25 2.84 20.8 3-56 4-48 23.0 4 76 6.00 16.5 0-95 I. 19 18.7 2.31 2.92 20.9 3.61 4.55 23.1 4 81 6.07 16.6 1. 01 1.27 18.8 2-37 2-99 21.0 3-67 4-63 23.2 4 86 6.13 16.7 1-05 1-33 18.9 2-43 3-07 21. I 3-73 4-71 23-3 4 92 6.20 16.8 1-13 1-43 19.0 2.49 3-14 21.2 3-78 4-77 23-4 4 97 6.27 16.9 1. 19 I-51 19. 1 2-55 3-22 21-3 3-84 4-84 23-5 5 02 6.33 17.0 1-25 1-58 19.2 2.61 3-29 21.4 3-90 4-92 17. 1 1.32 1.66 19-3 2.68 3-37 21-5 3-96 4-99 * Zeits. gesamte Brauwesen, 28, 1905, p. 259. Determination of Extract. — In cases where extreme accuracy is desired, the result obtained by evaporating at ioo° a weighed amount of the beer cannot be accepted, on account of the dehydration of the maltose at a temperature exceeding 75° C. Unless the evaporation is. conducted at that temperature (a difhcult operation), a closer approxi- 7i6 FOOD INSPECTION AND ANALYSIS. EXTRACT IN BEER WORT.* [According to Schultz and Ostermann.] Specific Gravity at 1 5° C. I . oooo I .0001 I . 0002 I . 0003 1 . 0004 1 .0005 1 .0006 1 . 0007 1 .0008 I .0000 I .00 TO 1 . 001 T 1 .001 2 1 .0013 1 .0014 1 .0015 1 .0016 I .0017 1 .0018 1 .0019 1 .0020 1 .0021 1 .0022 1 .0023 1 .0024 1 .0025 1 .0026 1 . 0027 I .0028 I .0029 1 .0030 I. 003 I I .0032 1.0033 1.0034 1.0035 I .0036 I » 003 7 1 .0038 1.0039 1 .0040 1 . 0041 1 . 0042 1.0043 I .0044 1 .004s 1 .0046 1 .0047 1 .0048 1 .0049 1 .0050 1 .005 I I .0052 1.0053 1.0054 I.ooss 1 .0050 1 .0057 1 .0058 1.0059 I .0060 1.0061 1.0062 1.0063 Z.0064 Ext -act. Grams Per Cent by per 100 cc. Weight 0.00 .00 0.03 0.03 0.05 0.0s 0.08 0.08 0. 10 . lO O.T3 0.13 0.16 0. 16 0.18 0.18 0.21 0. 2! 0. 24 0. 24 0.26 0. 26 0. 20 0. 20 0.31 0.31 0.34 0.34 0.37 . 37 0.39 0.39 0.42 0.42 0.45 0.45 0.47 0.47 0. 50 0. 50 0.52 0.52 0. 5> 0.55 0.58 0.58 0.60 0.60 0.O3 0.63 0.66 0.66 0.68 0.68 0.71 0.71 0.73 0.73 0.76 0.76 0.79 0.79 0.81 0.81 0.84 0.84 0.87 0.87 0.89 0.89 0.92 0. 92 0.94 0.94 0.97 0.97 I .00 1 .00 1 .02 I .02 I-05 1.05 1.08 1.08 I . 10 I . lO I.I3 I • 13 I.I5 1.16 1. 18 1. 19 1 . 21 1.22 1.23 1.24 1.26 1.27 1.29 I .30 1-31 1.32 1-34 1-35 1.36 1.37 1.39 I .40 1. 41 1.42 1.44 I.4S I .46 1.47 1.49 1.50 I. 51 I.S2 1-54 1.55 1 I.S6 1. 57 ! I. 59 1 .60 1.62 1.63 1 .64 1. 65 1.67 1.68 Specific Gravity at 15" C. 1 .0065 1 .0066 1 .0067 1 .0068 1 .0069 1 . 0070 1 .0071 1 .0072 1 .0073 1 .0074 1 .0075 1 .0076 1 .0077 1 .0078 1 .0079 1 .0080 1 .0081 1 .0082 1 .0083 1 .0084 1 .0085 1 .0086 1 .0087 1.0088 1 .0089 1 .0090 [ .0091 1 .0092 1 .0093 1 .0094 I . 009s 1 .0096 1 . 0097 1 .0098 1 .0099 1 .0100 1 .0101 1 .0102 1. 0103 1 .0104 1 .0105 1 .0106 1 . 0107 1 .0108 1 . 0109 1 . 01 10 1 .01 1 1 1 .01 1 2 1.0113 1 .01 14 1 .0115 1 .01 16 1 .01 17 1 .0118 1 .01 19 1. 01 20 1 .01 21 1 .01 22 1 .0123 1 . 0124 1 .0125 1.0126 1 .01 27 1 .0128 1 .0129 Extract. Per Cent bv Weight 1 . 69 1.72 1.74 1.77 1.79 1.82 1.84 1.87 1 . 90 1.92 1 .95 1.97 2.15 2.17 2 . 20 2.23 2.25 2.28 2.30 2.33 2.35 2.38 2 .41 2-43 2.46 2.48 2.51 2.53 2. 56 2.58 2 . 61 2. 64 2.66 2.69 2.71 2.74 2 . 76 2.79 2 .82 2.84 2.87 2.89 2 .92 2.94 3.02 3.05 3-07 3-23 3.25 3.28 3.30 i-ii Grams per 100 cc. 1.75 1.78 1 . 80 1.83 1.85 1.88 1 .91 1.93 1 . 06 1.98 2.02 2 . 04 2.07 2 .09 2.12 2.14 2.17 2.19 2.22 2.25 2 . 27 2.30 2.32 2.35 2.37 2 .40 2.43 2.45 2.53 2.55 2.59 2 . 61 2 .64 2 . 67 2 . 69 2.72 2.74 2.77 2. 79 2.82 2.85 2 . 2-95 2.97 3- 00 3.02 3-06 3.09 3. II 3.14 3-10 3.19 3- 21 3.24 3.27 3-29 3-32 3-34 3-37 Specific Gravity at 15° C. 0130 0131 0132 0133 0134 0135 0136 0137 0138 0139 0140 0141 0142 0143 0144 0145 0146 0147 0148 0149 0150 0151 0152 0153 0154 015s 0156 OIS7 0158 0159 ot6o oi6i 0162 0163 0164 0165 0166 0167 0168 0169 0170 0171 0172 0173 0174 0175 0176 0177 0178 0179 or 80 0181 0182 0183 0184 0185 0180 0187 0188 0189 019c 0191 0192 0193 0194 Extract. Per Cent by Weight •35 3. .38 3- .41 3- .43 ?•■ .46 3- .48 3- • 51 3- • 54 3- .56 3 .59 3- .61 3- .64 3- .66 3- .69 3- .72 3- ■ 74 3- • 77 3- .79 3- .82 3- .85 3- .87 3- .90 3- .92 3- .95 4- .97 4- .00 4- .03 4. • 05 4. .08 4. . 10 4- .13 4- .10 4- .18 4. . 21 4- •23 4- .26 4. .28 4. •31 4- .34 4- .36 4. ■39 4. .42 4. ■44 4- ■47 4. ■ 50 4- • 53 4. • 55 4. .58 4. .61 4 .63 4- .66 4. .69 4- ■71 4. •74 4- •77 4- ■ 79 4- .82 4- • Sc c,- .88 4- .90 4. • 93 5. .96 5. .98 5 . .01 5. .04 5. Grams per 100 cc. .46 .96 Specific Gravity at 15° C. 1. 0195 1 .0196 1. 0197 1 .0198 1 .0199 1 .0200 1 .0201 1 .0202 1 .0203 1 .0204 1 .0205 1 .0206 1 .0207 1 .0208 1 .0209 1 .0210 1 .021 1 1 .021 2 I .0213 1 .0214 1 .0215 1 .0216 1 .0217 1 .0218 1 .0219 1 .0220 1 .0221 1 .0222 1 .0223 1 .0224 1 .0225 1 .0226 1 .0227 1 .0228 1.0229 1 .0230 1. 0231 1 .0232 1.0233 I .0234 1.0235 1 .0236 1 .0237 1 .0238 1.0239 1 .0240 1 .0241 1 .0242 1.0243 I .0244 Extract. Per Cent bv Weight 5 .06 5.09 5.12 5-iS 5.17 5.20 5.23 5. 25 5.28 5.30 5.33 5. 35 5. 38 5.40 5.43 I .0248 1,0249 1 .0250 1. 0251 1 .0252 I.0253 I .0254 1^0255 1.0256 1.0257 1.0258 I .0259 5.57 5.60 5^62 5.6s 5.67 5^70 S.72 5.75 5.77 5.80 6.19 6.21 6 . 24 6.26 6 . 29 1.0245 •^.31 1.024^ I 6.34 .024; 6.36 6.39 6 .41 6.58 6.61 6.63 6.66 6.69 Grams per too cc. 5.16 5.19 5. 22 5.2s 5.27 5 . 30 5-34 5-36 5-39 5-41 5.44 5. 46 5-49 S-5I 5-54 5. 56 5.60 5-62 5. 65 5. 67 5. 83 5. 85 5.88 5.90 5. 93 5.9s 5. 97 6.00 6 . 02 6.06 6.08 6. II 6.13 6.16 6.18 6. 21 6.23 6.25 6.46 6.50 6.52 6.55 6.57 6.60 6.63 6.66 6.68 6.72 6.75 6.78 6.80 6.83 6.86 ' Calculated from results obtained by drying below 75° C. ALCOHOLIC BEI/ERAGES. EXTRACT IN BEER 'WOWT— {Continued). 717 Extract. Specific Extract. Specific Extract. Specific Extract. Specific Gravity Per Grams per 100 cc. Gravity Per jrams Gravity Per Grams Gravity Per Grams at 15° C. Cent by Weight at 1 5° C. Cent by Weight, per 100 cc. at 15° C. Cent bv Weight per 100 cc. at 15° C. Cent by Weight per 100 cc. I .0260 6.71 6.88 I .0325 8.27 8.54 1 .0390 9.92 10.31 1.0455 II. S3 12.05 1 .026'. 6.74 6.92 1.0326 8.29 8.56 1.0391 9.95 10.34 1 .0456 11-55 12.08 1.0262 6.77 6.95 I .0327 8.32 8.59 1.0392 9.97 10.36 1.04S7 11.57 12.10 1.0263 6.80 6.98 I .0328 8.34 8.61 1.0393 9-99 10.38 1.0458 1 1 . 60 12.13 1 .0264 6.82 7.00 1.0329 8.37 8.6s 1.0394 10.02 10.41 I -0459 II . 62 12.15 1.0265 6.85 7.03 I .0330 8.40 8.68 1.0395 10. 04 10.44 I .0460 II .65 12. 19 1 .0266 6.88 7 .06 I. 0331 8.43 8.71 1.0396 10.06 10.46 I .0461 11 .67 12. 21 I .0267 6 . 91 7 .09 1.0332 8.45 8.73 1.0397 10.00 10.49 I .0462 11.70 12. 24 1.0268 6.93 7.12 1.0333 8.48 8.76 1.0398 10. II 10.51 I .0463 11.72 I 2 . 26 1 .0269 6.96 7.1s 1.0334 8.51 8.79 1.0399 10.15 10.53 I .0464 11.75 12.30 1 .0270 6.99 7.18 1.0335 8.53 8.82 I .0400 10. 16 10.57 I .0465 11.77 12.32 1 .0271 7.01 7.20 1.0336 8.56 8.8s I .0401 10.18 10-59 I .0466 11.79 12.34 1 .0272 7.04 7 . 23 1.0337 8.59 ' 8.88 I .0402 10. 20 10. 61 I .0467 II .82 12.37 1.0273 7.07 7 . 26 1.0338 8.61 8.90 I .0403 10. 23 10 . 64 I .0468 11.84 12.39 1.0274 7.10 7.29 1.0339 8.64 8.93 t .0404 10.25 10. 66 I .0469 II .87 12.43 1. 027s 7.12 7.32 1.0340 8.67 8.96 I .0405 10. 27 10.69 I .0470 11.89 12.45 I .0276 7.15 7.3s I. 0341 8.70 9 .00 I .0406 10.30 10.72 I. 0471 11.92 12.48 1.0277 7.18 7.38 1.0342 8.72 9.02 I .0407 10.32 10.74 1.0472 11.94 12.50 I .0278 7.21 7-41 1.0343 8.75 9.05 I .0408 I0.35 10.77 1-0473 11.97 12.54 1.0279 7.23 7.43 1.0344 8.78 9.08 I .0409 10.37 10.79 1.0474 11-99 12.56 1 .0280 7 . 26 7.46 1.034s 8.80 9. 10 I .0410 10.40 10. S3 1.0475 12.01 12.58 I .0281 7.28 7.48 1.0346 8.83 9.14 1 .0411 10 .42 10.85 I .0476 12.04 12. 6l I .0282 7.30 7.51 I. 0347 8.86 9.17 1 .0412 10.4s 10.88 1.0477 12 .06 12 . 64 I .0283 7-33 7.54 1.0348 8.88 9.19 I. 041 3 10.47 10.90 I .0478 I 2 . 09 12.67 1.0284 7.3s 7.56 1.0349 8.91 9.22 I .0414 10.50 10.93 1.0479 12. II 12 . 69 1.028s 7.37 7.58 I.03S0 8.94 9-25 I. 0415 IO.S2 10.96 I .0480 12.14 12.72 1.0286 7.39 7.60 1. 035 1 8.97 9.28 I .0416 10. SS 10.99 I .0481 12.16 12.74 1 .0287 7.42 7.63 1.0352 8.99 9.31 I. 0417 10.57' II .01 I .0482 12.19 12.78 1.0288 7.44 7.6s 1.0353 9.02 9-34 I .0418 10.60 11 .04 1.0483 12.21 12.80 I .0289 7.46 7.68 1.0354 9.05 9.37 1 .0419 10.62 11 .06 1 .0484 12.23 12.83 I .0290 7.48 7.70 1.035s 9.07 9.39 I .0420 10.65 11 .10 1.0485 12. 26 12.8s I .0291 7.51 7.73 I .0356 9.10 9.42 I .0421 10.67 11.12 I .0486 12.28 12.88 I .0292 7.53 7.7s 1.0357 9-13 9.46 1 .0422 10.70 II. 15 I .0487 12.31 12.91 1.0293 7.55 7.77 I 0358 9-15 9.48 1.0423 10. 72 II. 17 1.0488 12.33 12.93 1 .0294 7.57 7-79 1.0359 9. iS 9-51 1.0424 10.75 11.21 I .0489 12.36 12.96 1.0295 7.60 7.82 I .0360 9. 21 9.54 1.0425 10.77 11.23 1 .0490 12.38 12.99 I .0296 7.62 7-85 I .0361 9.24 9.57 I .0426 10. So 11 . 26 I .0491 12.41 13.02 1.0297 7.64 7.87 I .0362 9. 26 9.60 1.0427 10.82 11.28 I .0492 12.43 13.04 I .0298 7.66 7.89 1.0363 9.29 9.63 I .0428 10.8s II. 31 1.0493 12.45 13.06 I .0299 7.69 7.92 I .0364 9.31 9.65 1 .0429 10.88 11-35 1.0494 12.48 13.10 I .0300 7.71 7.94 1.036s 9.34 9.68 1.0430 10.90 11.37 1.0495 12.50 13-13 1. 0301 7.73 7.96 I .0366 9.36 9.70 1. 043 1 10.93 11 .40 I .0496 12.53 13.15 1.0302 7-7S 7.98 1.0367 9.38 9.72 1.0432 10.9s II .42 1.0497 12.55 13.17 1-0303 7-77 8.01 1.0368 9.41 9.76 1.0433 10. 98 1 1 .46 I .0498 12.58 13.21 1.0304 7. So 8.04 1 .0369 9.43 9.78 1.0434 11 .00 11.48 I .0499 12.60 13.23 1.0305 7.82 8.06 1.0370 9.45 9.80 1.0435 II .03 II. SI 1.0500 12.63 13.26 1 .0306 7.84 8.06 I. 0371 9.48 9.83 I .0436 11.05 11.53 I .0501 I 2 . 6.5 13.28 1.0307 7.86 8.10 1.0372 9.50 9.85 1.0437 II .08 11.56 I .0502 I 2 .67 13.31 I .0308 7.89 8.13 1.0373 9.52 9.88 1.0438 11.10 11.59 1.0503 12. 70 13-34 1.0309 7.91 8. IS 1.0374 9.55 9.91 1.0439 11.13 1 1 .62 1.0504 12.72 13-36 I. 0310 7-93 8.18 1.0375 9-57 9-93 I . 0440 II. 15 II .64 I. 050s 12.75 13-39 1.0311 7.95 8.20 1.0376 9.59 9-95 I .0441 II. 18 11 .67 1 .0506 12.77 12.80 12.82 13.42 1.0312 7.98 8.23 1.0377 9.62 9. 98 1.0444 1 1 . 20 11 .70 1.0507 13.45 1.0313 8.00 8.2s 1.0378 9.64 10 .00 1.0443 11.23 11.73 I .0508 13-47 I. 0314 8.02 8.27 1.0379 9.66 10.03 1.0444 1 1 . 25 "•75 1 .0509 12.8s 13.50 1.0315 8.04 8.29 I .0380 9.69 10.06 1.0445 11.28 11.78 1.0510 12.87 13.53 13.56 13.58 1 .0316 8.07 8.33 1.0381 9.71 10.08 I .0446 II .30 11.80 I .0511 12 .90 1. 0317 8.09 8. 35 1 .0382 9.73 10 . 10 1.0447 11-33 11.84 I. 0512 12.92 1. 03 1 8 8. II 8.37 1.0383 9.76 10.13 I . 0448 II -35 11.86 1.0513 12.94 13-60 13.64 1.0319 8.13 8.39 1.0384 9.78 10.16 1.0449 II 58 11.89 1.0514 12.97 I .0320 8.16 8.42 1.0385 9.81 10. 19 I .0450 1 1 .40 11 .91 1.0515 12.99 13.66 13-69 I .0321 8.18 8.44 1.0386 983 10. 21 I. 0451 11-43 11.95 I .0516 13.02 1.0322 8.20 8.46 1.0387 9.85 10. 23 I .0452 11-45 11.97 I. 0517 13.04 13-71 1.0323 8.23 8.49 1.0388 9.88 10. 26 I. 0453 11.48 12.00 1.0518 13.07 13.75 1.0324 8.2s 1 8. 52 1.0389 9.90 10. 29 I .0454 11.50 12.02 1.0519 13.09 13.77 7i8 FOOD INSPECTION ^ND ^N^ LYSIS. EXTRACT IN BEER WORT— (Cojttinucd). Extract. Specific Extract. Specific Extract. Specific Extract. Specific Gravity Per Grams Gravity Per Grams Gravity Per Grams Gravity Per GramS5 at 15° C. Cent by Weight per 100 cc. at 15° C. Cent by Weight per 100 cc. at 15° C. Cent by Weight per 100 cc. at 15° C. Cent by Weight per 100 cc. I .0520 13-12 1380 1.0585 14-75 15.61 1 .0650 16.25 17-31 1.0715 17.81 19. 08 I .0521 13.14 13.82 1.0586 1.V.78 15.65 I .0651 16, 27 17-33 I .0716 17-84 19.12 1 .0522 i3-i6 13.85 1.0587 14.81 15.68 I .0652 16.30 17.36 1 .0717 17.86 19-14 1 .0523 13.19 13.88 1.0588 14.83 15.70 1.0653 16.32 17.39 I .0718 17-88 19.16 1.0524 13.21 13.90 I .05S9 14.86 15-74 1.0654 16.35 17.42 1.0719 17.90 19.19 I .0525 13.24 13.94 1.0590 14.89 15-77 1-0655 16.37 17-44 I .0720 17-93 19.22 1 .0526 13.26 13.96 1.0591 14.91 15-79 1 .0656 16.40 17-4S I .0721 17-95 19.24 I 0527 13- 29 13.99 1.0592 14.94 15-82 1.0657 16.42 I 7 - so I .0722 77.97 19.27 1 .0528 13.31 14.01 1.0593 14.96 15-85 1.0658 16.45 17-53 I -0723 17.99 10. 29 1 .0529 13.34 I4.05 1.0594 14.99 15-88 1 .0659 16.47 17.56 1.0724 1S.02 19.32 I .0530 13.36 14.07 1.0595 15.02 15-91 1 .0660 16.50 17.59 1.0725 18.04 19-35 1. 0531 13.38 14.09 1 .0596 15.04 15-94 1 .0661 16.52 17.61 I .0726 18.06 19-37 I .0532 13.41 14. 12 1.0597 15.07 15-97 1 .0662 16.54 17.63 1.0727 18.08 19- SQ-' 1.0533 13-43 14.15 1.0598 15-09 15.09 1 .0663 16.57 17-67 I .0728 18. II 19-43- I-OS34 13.46 14.18 1.0599 15.11 16.02 I .0664 16.59 17.69 1 .0729 18.13 19-45 1.0535 13.48 14. 20 I .0600 15.14 16.05 1 .0665 16.62 17-73 1.0730 18.1s 19.47 I .0536 13.51 14.23 I .0601 15.16 16.07 1 .0666 16.64 17-75 1.0731 18.17 I9.50r- 1.0537 13-53 14. 26 I .0602 15.18 16.09 I .0667 16.67 17-78 1.0732 18.20 19-53^ I .0538 13.56 14-29 1 .0603 15.20 16.12 1.0668 16.69 17.80 1-0733 18.22 19-55 I 0539 13.58 1431 1 . 0604 IS 23 1615 I 0669 16.72 17-84 1.0734 1S.24 19-SS. I .0540 13.61 14-34 1.0605 15.25 16.17 I .0670 16.74 17-86 1.073s 18.26 1 9 . 60 1 .0541 13.63 14-37 1 . 0606 15.27 16 . 20 1 .0671 16.76 17-88 1.0736 18.29 19.64 1.0542 13-66 14.40 1 .0607 15.29 16.22 1 .0672 16.79 17.92 1-0737 18.31 19.66- I .0543 13-68 14.42 I .0608 15-31 16. 24 1.0673 16.81 17.94 1.0738 18.33 19.68- I.OS44 13-71 14.46 I .0609 15-34 lO . 27 I .0674 16.84 17.98 1.0739 18.35 19-71 1 .0545 13-73 14.48 1 .0610 iS-36 16.30 1.0675 16.86 18.00 I -0740 18.38 19-74- J .0546 13-76 14-51 I .0611 iS-38 16. 32 1 .0676 16.89 18.03 1.0741 18.40 19.76 I .0547 13-78 14-53 1 .0612 .15-40 16.34 1.0677 16.91 18.05 1.0742 18.42 19.79. 1.0548 13-81 14-57 I .0613 15-43 1^-38 1.0678 16.94 18.09 1.0743 18.44 19.81 1.0549 13-83 14-59 I . 0614 15-45 16 . 40 I .0679 16.96 18.11 1.0744 18.47 19.84. 1.0550 13.86 14.62 I. 0615 15-47 16.42 1.0680 16.99 18.15 1.074s 18.49 19-87 1.0551 13.88 14.64 I .0616 15-49 16.44 1.0681 17.01 18.17 1 .0746 18.51 19.89- 1.0552 13-91 14.68 I .0617 15.52 16.48 1.0682 17-03 18.19 1.0747 18.53 19.91 1 .0553 13-93 14.70 I. 0618 15.54 16.50 1.0683 17 . 06 18.23 1.0748 18.5s 19.94- I.OS54 13-96 14-73 I .0619 15-56 16.52 I .0684 17.08 18.2s 1.0749 18.57 19.96 1.055s 13-98 14.76 I .0620 15-58 16.55 T.0685 17. II 18.28 1.0750 18.59 19. 9» 1 .0556 14.01 14.79 I .0621 15-60 16.57 1.0686 17-13 18.31 1.0751 18.62 20. 02- I. 0557 14-03 14.81 1 . 0622 15-63 16. 60 1.0687 17.16 18.34 1.0752 18.64 20.04 1.0558 14. 06 14.84 1.0623 15-65 16.62 1.0688 17.18 18.36 I.0753 18.66 20 .07 1.0559 14.08 14.87 I .0624 15.67 16.64 1 .0689 17.21 18.40 1-0754 18.68 20.05> I .0560 14. II 14.90 I .0625 15.69 16.66 I .0690 17-23 18.42 1.0755 18.70 20 . II I .0561 14-13 14.92 I .0626 15.72 16. 70 1 .0691 17-25 18.44 1.0756 18.72 20. 14 1 .0562 14.16 14.96 I .0627 15-74 16.73 I . 0692 17.28 18.48 1.0757 18.74 20. 16 1.0563 14.18 14.98 1.0628 15-76 16.75 I .0693 17.30 18.50 1.0758 18.76 20. iS 1.0564 14.21 15.01 I .0629 15-78 16.77 I .0694 17-33 18.53 1.0759 18.78 20. 21 1'0565 14-23 15.03 I .0630 15.80 16.80 I .0695 17-35 18.56 1 .0760 18.81 20. 24 r. 6566 14. 26 15.07 I. 0631 15.83 16.83 1 .0696 17-38 18.59 1 .0761 18.83 20. 26 I .6567 14-28 15.09 1.0632 15.85 16.85 1 .0697 17-40 18.61 1 .0762 18.85 20. 29 1.0568 14-31 .15.12 1.0633 15.87 16.87 1 .0698 17-43 18.65 1 .0763 18.87 20.31 1.0569 14-33 15.15 1.0634 15.89 16.90 1 .0699 17-45 •18.67 1 .0764 18.89 20.33 1.0570 14.36 15.18 1.0635 15.92 16.93 1 .0700 17-48 18.70 1.0765 18.91 20.36 1.0571 14-38 15 . 20 1.0636 15-94 16.95 1 .0701 17.50 18.73 1 .0766 18.93 20. 3S 1.0572 14-41 15.23 1-0637 15-96 16.98 I .0702 17.52 18.75 1.0767 18.95 20 . 40' 1.0573 14.44 15.27 1-0638 15.98 17 .00 1.0703 17.54 18.77 1.0768 18.97 20.43 1.0S74 14.46 15.29 1.0639 16.01 17-03 1 .0704 , 17.57 18.81 I .0769 19.00 20.46 1.057s 14.49 15.32 1 .0640 16.03 17 .06 1.0705 17.59 18.83 1.0770 19.02 20. 4S 1.0576 14-52 15.36 I .0641 16.05 17.08 I .0706 17.61 18.85 1 .0771 19.04 20. 51 1.0577 14.54 JS.38 I .0642 16.07 17.10 1.0707 17.63 18.88 1.0772 19.06 20.53 1.0578 14.57 15.41 1.0643 16.09 17.12 1 .0708 17.66 18.91 1.0773' 19.08 20.55 1.0579 : 14.59 15.43 1.0644 16.12 17.16 I .0709 17.68 18.93 1-0774 19. 10 20.58 I .0580 14.62 15.47 1 .0645 16. 14 17.18 I .0710 17.70 18.96 1.077s 19.12 20.60 I. 0581 14.65 15.50 1 .0646 16.16 17 . 20 1 .0711 17.72 18.98 1.0776 19-14 20.63 i.0584 14.67 15.52 1 .0647 16.18 17.23 1 .0712 17.7s' 19.01 1.0777; 19.17 20.66 1.0583 14.7,0. ,15.56 1 .0648 16.21 17.26 1.0713 17.77, 19.04 1.0778' 19.19 20.68 I .0584 14.73 l'S.59 5. 0649 16.23 17.28 I .0714 17.79 19.06 1.0779 19.21 20.71 ALCOHOLIC BEVERAGES. 719 EXTRACT IN BEER WORT— (CoM/mweJ), Extract. Specific E.xtract. Specific Extract. Specific Extract. Specific * Gravity Per Grams Gravity Per Grams Gravity Per Grams per loo cc. Gravity Per Grams per 100 cc. at 15° C. Cent by Weight per 100 cc. at 15° C. Cent by Weight per 100 cc. at 15° C. Cent by Weight at 15° C. Cent bv Weight I .0780 19-23 20.73 I -0845 20. 70 22.45 I .0910 22 . ig 24. 21 1.0975 23-59 25.89 1.0781 19.25 20.75 1.0846 20.73 22.48 I .0911 22. 21 24.24 I .0976 23-61 25.92 I .0782 19.27 20.78 1.0847 20.75 22 . 50 I .0912 22.23 24. 26 1.0977 23-63 25 -94 1.0783 19.29 20.80 1.0848 20.77 22.53 I. 0913 22. 26 24-29 1.0978 23-65 25.97 1 .0784 1931 20.82 I .0849 20.79 22.55 I. 0914 22.28 24.31 1.0979 23.67 25.99 1.078s 19-33 20.85 I .0850 20.81 22.58 I. 0015 22.30 24-34 I .0980 23.69 26.01 1.0786 19.36 20.88 1.0851 20.83 22 . 6l I .0916 22.32 24-37 I .0981 23-71 26.04 1.0787 19-38 20.90 1.0852 20.86 22 .64 I .0917 22.34 24.39 I .0982 23-73 26 .06 1.0788 19.40 20.93 1.0853 20.88 22 . 66 I .0918 22.37 24.42 I .0983 23-76 26.09 1.0789 19.42 20.95 I. 0854 20.90 22.68 I .0919 22.39 24-44 I .0984 23.78 26. 11 I .0790 19.44 20.98 1.085s 20.93 22.72 1 .0920 22.41 24.47 1.0985 23.80 26. 14 1.0791 19.46 21 .00 1.0856 20.95 22.75 I .0921 22.43 24-49 I .0986 23.82 26. 17 1.0792 19.49 21.03 1.0857 20.98 22.78 1 .0922 22.45 24-51 1 .0987 23-84 26. 19 1.0793 19-S1 21 .06 1.0858 21.01 22. 8l 1.0923 22 48 24-54 1.098S 23.86 26. 22 1.0794 19-53 21.08 1.0859 21 .04 22.84 1.0924 22.50 24-56 I .0989 23.88 26. 24 I-0795 •19.56 21 . 1 1 1.0860 21 .06 22.87 1.092s 22.52 24.60 I .0990 23.90 26. 27 I .0796 19-58 21 . 14 I .0861 21 .09 22 . 90 I .0926 22.54 24.62 I .0991 23.92 26.30 1.0797 19.60 21.16 1.0862 21 . 1 1 22.93 1.0927 22. 56 24.64 I . 0992 23.94 26.32 I .0798 19.63 21 . 20 1.0863 21.13 22 .96 1 .0928 22.59 24.67 1-0993 23-97 26.3s 1.0799 19.65 21 . 22 1.0864 21 . 16 22.99 1.0929 22 .61 24.70 1.0994 23-99 26.37 I .0800 19-67 21 . 24 1.0865 21 . 10 23.02 1.0930 22.63 24-73 1.0995 24.01 26.40 1 .0801 19.70 21.28 1.0866 21.22 23.06 1.0931 22.65 24-76 I .0996 24.03 26.42 I .0802 19.72 21 .30 1.0867 21 .25 23.09 1.0932 22.67 24.78 1.0997 24-05 26.44 I .0803 19-74 21.33 1.0868 21 . 28 23.12 1-0933 22.69 24.81 1 .0998 24-07 26.47 I .0804 19.77 21.36 1.0869 21 .30 23-15 1-0934 22.71 24.83 1.0999 24.09 26.49 1.0805 19.79 21.38 I .0870 21.33 23.18 1-0935 22.73 24.86 I . 1000 24. 1 1 26.52 1 .0806 19.81 21 .41 I. 0871 21.35 23.21 1.0936 22.75 24.89 1 . lOOI 24-13 26.55 1 .0807 19.84 21 .43 1.0872 21.37 23.23 1-0937 22.77 24.91 I . 1002 24-15 26.57 1.0808 19.86 21 .46 1.0873 21.39 23.26 1.0938 22.80 24-93 I. 1003 24.17 26.60 1 .0809 19.88 21.49 1-0874 21 .41 23.28 1.0939 22.82 24.96 I . 1004 24.19 26.62 I .0810 19.91 21.52 1-0875 21.43 23-31 I .0940 22.84 24.99 1.1005 24. 21 26.6s I .0811 19.93 21.55 1.0876 21.45 23-33 I. 0941 22.86 25.01 I . 1006 24.23 26. 6» 1 .0812 19.96 21.58 1.0877 21.47 23-36 1.0942 22.88 25.03 I . 1007 24.25 26. 70 I. 0813 19.98 21 .60 1.0878 21.49 23-38 1.0943 22 . 90 25.06 1 . 1008 24.28 26.73 I .0814 20.00 21 .63 1.0879 21.51 23-40 1.0944 22.92 25.08 I . 1009 24-30 26.75 1.081S 20.03 21 .66 1.0880 21.54 23-43 1.0945 22.94 25.11 I . lOIO 24.32 26.78 I. 0816 20.05 21 .69 I. 088 I 21.56 23-45 I .0946 22.96 25-14 1 . lOII 24.34 26.81 1 .0817 20 .07 21.71 1.0882 21.58 23.48 1.0947 22.98 25- 16 1 . IOI2 24-36 26.83 I. 0818 20. 10 21.74 1.0883 21 .60 23-50 I .0948 23.00 25-18 I. 1013 24-39 26.86 1 .0819 20. I 2 21-77 1.0884 21 .62 23-52 1.0949 23-03 25. 21 I . IOI4 24.41 26. 8& I .0820 20. 14 21.79 1.0885 21 .64 23-55 1.0950 23-05 25-24 I .10x5 24-43 26.91 I .0821 20. 17 21.8? 1.0886 21.66 23-58 1.0951 23-07 25.26 I . IO16 24-45 26.93. I .0822 20. 19 21.85 1.0887 21.68 23 -60 1.0952 23-10 25.29 I . IOI7 24-47 26.9s 1.0823 20. 21 21 .87 1.0888 21.71 23-63 1.0953 23-12 25-31 1 . IO18 24-49 26.98. I .0824 20. 24 21 .91 1.0889 21.73 23-66 1.0954 23-14 25-34 I . IOI9 24-51 27.00 1.082s 20. 26 21.93 I .0890 21.75 23.69 1.095s 23-16 25-37 1 . 1020 24.53 27-03 1.0826 20. 28 21 . 96 I .0891 21.77 23-72 1.0956 23.18 25-39 I . I02I 24.5s 27.06 1.0827 20.31 21.99 I .0892 21.79 23-74 1-0957 23-20 25-42 1 . 1022 24-57 27.08' 1.0828 20.33 22 .01 1.0893 21.82 23-77 1.0958 23.23 25-45 1.1023 24. 60 27.11 1 .0829 20.35 22 . 04 I .0894 21.84 23-79 1.0959 23.25 25-47 I . 1024 24.62 27.14. I .0830 20.37 22 .06 I .0895 21.86 23-82 I .0960 23.27 25-50 1.1025 24.64 27.17 1 .0831 20.39 22.08 1.0896 2i.8g 23-85 I .0961 23.29 25.53 1 . 1026 24.66 27.19 1.0832 20.41 22. n 1.0897 21 .91 23-87 I .0962 23-31 25.55 1 . 1027 24.68 27:21 1.0833 20.43 22.13 1.0898 21.93 23.90 1.0963 23.33 25-58 I . 1028 24-70 27-24 1.0834 20.46 22.16 I .0899 21 . 96 23-93 I .0964 23.35 25.60 1 . 1029 24.72 27. 26 1.083s 20.48 22 . 19 I .0900 21.98 23.96 1.0965 23.37 25.63 1.1030 24.74 27. 2(^ 1.0836 20.50 22. 21 I .0901 22 .00 23.98 I .0966 23.39 25.66 I.IO31 24.76 27.32 1.0837 20.52 22 . 24 I .0902 22 .02 24.01 1.0967 23.41 25.68 I. 1032 24-78 27.34 1.0838 20.54 22.26 I .0903 22 .04 24.03 I .0968 23-44 25-71 1.I033 24.81 27-37 1.0839 20.56 22 . 29 I .0904 22.06 24.05 I .0969 23.46 25-73 1.1034 24.83 27.39 1 .0840 20.59 22.32 1.0905 22.08 24.08 1.0970 23-48 25.76 I-1035 24.85 27.42 I .0841 20.62 22.35 1 .0906 22 . 10 24. 1 1 1. 0971 23-50 25-79 I .1036 24.87 27.45 I .0842 20 . 64 22.38 1.0907 22.12 24.13 1.0972 23-52 ,25.81 1.1037 24.89 27.47 1.0843 20.66 22 .40 I .0908 22.15 24. 16 1-0973 23.55 25.84 I. 1038 24.92 27.50 1.0844 20.68 22 .42 I .0009 22.17 24.18 1.0974 23-57 25.86 I. 1039 24.94 27-53 720 FOOD INSPECTION AND ANALYSIS. EXTRACT IN BEER WOKT— {Concluded). Extract. Specific Extract. Specific E.Ktract. Specific Extract. Specific Gravity Per Grams Gravity Per Grams Gravity Per Grams Gravity Per Grams at 15° C. Cent bv Weight per 100 CO. at 15° C. Cent by Weight per 100 cc. at 15° C. Cent by Weight per 100 cc. at 15" C. Cent by Weight per 100 cc. 1 . 1040 24.96 27-56 1.109s 26. 16 29.03 1.1150 27.29 30.43 1 .1205 28.38 31-81 1 . 1041 24.98 27-58 I . 1096 26.18 29.06 1.1151 27-31 30.45 1 . 1 206 28.40 31-83 I . 1042 25.00 27 .60 1.1097 26. 20 29.08 1.1152 27-33 30.47 1 . 1 207 28.42 31-86 I . 1043 25-03 27-63 I . 1098 26. 23 29. 1 1 1.1153 27-35 30.50 I . I 208 28.44 31-88 1.1044 25-05 27.66 1.1099 26.25 29-13 1-1154 27-37 30.52 1 . 1 209 28.46 31 -03 I .1045 25 .07 27.69 1 . 1 100 26. 27 29 . 16 1-1155 27-38 30.55 1 . 1210 28.48 31-93 1 . 1046 25 .09 27.72 I . I lOI 26. 29 29-19 I .1156 27.40 33-57 I . I 21 1 28.50 31.95 1.1047 25.11 27-74 1 . 1 102 26.31 29. 21 1-1157 27.42 30.59 1 . 1 21 2 28.52 31-98 I . T048 25-14 27.77 1.1103 26.33 29.24 1-1158 27.44 30.62 1.1213 28.54 32.00 1. 1 049 25.16 27.79 I . 1104 26.3s 29. 26 1.1159 27.46 30.64 1 . 1 214 28.56 32.03 1 . 1050 25.18 27.82 1.1105 26.37 29.29 1 . 1160 27-4S 30. 67 1.1215 28.58 32-05 1.1051 25 . 20 27.85 I . 1106 26.30 29.32 t . 1 161 27 - 50 30.69 I . 12l6 28.60 32-08 I. 1052 25 . 22 27-87 1 . 1 107 26 .41 29-34 1 . 1162 27.52 30.72 I.I2I7 28.62 32.11 I-I053 25-24 27.90 1.1108 26.44 29-37 1.1163 27-54 30.75 1 .1218 28.64 32.13 I. 1054 25-27 27-93 1 . 1109 26.46 29-39 1 . 1164 27.56 30-77. 1 . 1219 28.66 32.15 I.IOS5 25.29 27.96 1 . 11 10 26.48 29.42 I . 1165 27-58 30 . 80 1 . 1220 28.68 32.18 I . 1056 25-31 27-98 1 1 . 1 1 1 1 26 . 50 29-44 1.1166 27 . 60 30-82 r . I 221 28.70 32.20 I. 1057 25.33 28.00 1 . 1112 26.52 29.46 1 . 1167 27 . 02 30-S5 1 . 1222 28.72 32-23 1.1058 25-35 28.03 1.1113 26.54 29.49 1. 1 1 68 27.64 30. 3 7 I. 1223 28.74 32-2S 1. 1059 25-38 28.06 1 . 1114 26.56 29-51 1 . 1 169 27.66 30.89 I . 1224 28.76 32.27 1 . 1060 25.40 28.09 1.1115 26.58 29-54 I . 1 170 27 .63 30 . 9 J I. 1225 28.78 32.30 1 . 1061 25-42 28.12 I . II 16 26.60 29-57 I .1171 27.70 30.04 I . r 226 28.80 32.3* 1 . 1062 25-44 28.14 I.III7 26.62 29.59 1.1172 27.72 30.97 I . 1 227 28.82 32.3s 1. 1063 25.46 28.17 1.H18 26.64 29.61 I .1173 27-74 3t .00 I. 1228 28.84 32.37 I . 1064 25.48 28.19 1 . 1119 26.66 29.64 1.1174 27.7 J 3r.o2 I . 1229 28.86 32.40 r.1065 25-50 28.22 1 . 1 1 20 26.68 29.67 1-1175 27.78 31.05 I 1.1230 28.88 32.43 1 . 1066 25-52 28.25 I . II 21 26. 70 29.69 1 . 1 176 27.80 31-07 1-1231 28.90 32.4s 1 . 1067 25-54 28.27 1 . 1 122 26. 72 29.71 I. 1177 27.82 31'"- 09 1.1232 28.92 32.48 1. 1068 25-57 28.30 1.1123 26.7s 29.74 1.1178 27-S4 31.12 I-I233 28.94 32.50 I . 1069 25-59 28.32 1 . 1 1 24 26.77 29-77 1.1179 27.86 31.15 I -1234 28.96 32.53 I . 1070 25.61 28.35 I . II 25 26.79 29.80 1.1180 27. 38 31. iS I-1235 28. 98 32.56 1 . 1071 25-63 28.38 1 . 1 1 26 26.81 29.83 1.1181 27.90 31.23 I .1236 29 . 00 32.53 1 . 1072 25-65 28.40 1.1127 26.83 29-85 1.1182 27.92 31-23 I-1237 29.02 32.60 1. 1073 25-67 28.43 1. 1 128 26.85 29.88 1.1183 27-94 31-25 I -1238 29.04 32.63 1. 1074 25-69 28.45 1 . 1129 26.87 29.90 1.11S4 27-96 31.27 1.1239 29.06 32.6s 1. 1 07 5 25-71 28.48 I. 1130 26.89 29-93 1.118s 27.98 31.30 I . I 240 29.08 32.68 I . 1076 25-73 28.51 1 . 1 131 26.91 29-95 1.1186 28.00 31.32 I . I 241 29. 10 32.71 1.1077 25.75 28.53 1.1132 26.93 29.97 1.1187 28.02 3I-3S 1.1242 29. 1 2 32.73 1 . 1078 25-78 28.56 1-1133 26.95 30-00 i.uSS 28.04 31-37 1.1243 29.14 32.76 1. 1079 25-80 28.58 1. 1 1 34 26.97 30.02 1.1189 28.07 31.40 1 . 1 244 29. 16 32.78 I. 1080 25-82 28.61 I.II3S 26.99 30.06 1 . 1 190 28.09 31.43 1 . 1 24s 29.18 32.81 1 . 1081 25-84 28.64 1 . 1 136 27.01 30.08 1 . 1 191 28.11 31.45 I . 1 246 29. 20 32.83 I . 1082 25-86 28.66 I-I137 27.03 30.10 1 .1192 28.13 31.48 1. 1 247 29. 22 32. 8& t.io8j 25-89 28.69 I-1138 27.05 30.13 1.1193 28.1^ 31-51 1.1248 29.24 32.89 I . 1084 25-91 28.72 1.1139 27.07 30.15 1.1194 28.17 31-53 1.1249 29. 26 32.91 1 .1085 25-93 28.75 I . 1 140 27.09 30.18 I. 1195 28.19 31.56 1.1250 29.28 32-94 1.1086 25.96 28.78 1 . 1 141 27.11 30.20 1 . 1196 28.21 31.59 1.1251 29.30 32.96 1 . 1087 25-98 28.80 1.1142 27.13 30.22 1.1197 28.23 31 -61 1.1232 29.32 32-99 1 . 1 088 26.01 28.83 1.1143 27.15 30.25 1.1198 28.25 31.63 I. 1253 29-34 33 -°2 1 . 1089 26.03 28.86 1.1144 27.17 30.27 1.1199 28. 27 31-65 I. 1254 29.36 33-04 I . 1000 26.05 28.89 1.1145 27.19 30.31 1.1200 28.28 31.68 I.I2SS 29.38 33-07 I .1091 26.07 28.92 1 . 1146 27.21 30.33 I .1201 28.30 31.70 1.1256 29.40 33.09 I . 1092 26.09 28.94 I. 1147 27.23 30.3s I. 1202 28.32 31-73 1.1257 29.42 33.12 I .1093 26. 12 28.97 1.1148 27.25 30.37 1. 1 203 28.34 31-75 1.1258 29-45 33-14 1. 1094 26. 14 29.00 I. 1149 27.27 30.40 I . 1204 23. 36 31-78 1.1359 29.47 33.17 ALCOHOLIC BEyF.RAGES. 721 oi w u, a S H < oi b w oi * ^ Dc; 1— 1 C/J oi q5 w W w S pq W H S a C H D« < U< J J 1— 1 h ►ii m U !?^ W 1— 1 W h H c; Uh < a: H a X Z w < °< l-H Di l-H W pq 2 a < E h Ul pq ij^ Pi n tn 2 W Q < Pi Ex- tract in 100 cc. Grams. O-OOOWMMM t^oOoOoOQOOCCOoO iNvooo rovoco COO CM CN CM CM corororo-^Tfrj- OOCOoOOOOOoOoOOOOOOOoo' ft; 1 1^ M -ir0\0 On- -+0 Ovi-1 Tft^O\CM -t- ^. '7'~;-'^'^°oocoooo o^on 1 ft; On -' <^ <-^, ^in^o f>-00 OnO '-' CM r-^rj-lOMD t~-00 On Ex- tract in 100 cc. Grams. r^oOw'^vOOOw'* OOOOOOmm NO CMior^O coiooo CO M CM CM (N CM COf^cOrO'^Tj" « \Ovo t^r^t^r^t^t^ t^r^t-^t^i^t^r^t^i^t^r^ ft; 1 ft; 1-1 CM r^, -tiovO r-oo OncO m cm <^. -^ ir, \0 t^ CO On Ex- tract in 100 cc. Grams. 1000 roiooo M "^ nOOO " rr) \o Onm -tJ-nO Onm nOnO J^f^i^r^oooocooo On O^vOOOO^^ nOnCnOnOnCnCnCOnOnOno 1 ft; H-i c^ "-J -f u-i \C' r^ CO OnnO m cm r^^iONO f-OO On Extract in 100 cc. Grams. 5> ooooooo- •+ r^ 0- c< 10 t^ cN) in t^ "««CMCMo t^OC On CM Extract in 100 cc. Grams. ^ CM loi^o roioco r<^lO00 M cOnOOO w rONO On nOnOnO r^r^t^r-~o0O0o0O0 10 •LOI/IVOI/^IOIOIOIO voioiotoiow-itomtovou-i ft; 1 ft; CM "- !^ c^rtly-JO t^X Oncm -h cm r^-rflONC t^OO On CM Extract in 100 cc. Grams. 00 CO " <^^OoO " -1"^ OO-D^OO " -^r^O-'N -t-f^ONCM iy-)t^ ^^►-.H-CNCMncMrO'^^'^O ^ 1- "i- -t -t w-J >J^. U-. 10 U-) vn m 10 m Ul U-. ii-5 m U-) 10 ft; 1 ft; M CM POrj-lovO t--00 OnO m cm cr-Tj-LONO t^oo On Extract in 100 cc. Grams. 0«M"^r^O0 t^OO ONC50 M CM r<-, -i-u^nC r^OO On Extract in TOO cc. Grams. CO 1-1 roOOO " -to CO OnOnOnOnO On^ *-fNO Onci Tj-r^osCM -t OmmmmCNCMCMMI^'T^ <^' r-^rorororO'i-'*'* ■^'t-^'i-Tl-Tt-i-'-tTrTl-T)- ft; 1 ft; w CM ro^^^O f^OO OnnO m CM rO'^iONO t^OO On 72 2 FOOD INSPECTION /IND /IN A LYSIS. mation to the truth is obtained, especially with beer high in sugar, by calculation as follows: From the Specific Gravity. — Evaporate a measured quantity of the beer to one-fourth its volume on the water-bath, make up with water to its original measure, and determine the specific gravity of the deal- coholized beer. Then by means of Schultz and Ostermann's table, pp. 716-20, calculate the extract corresponding. From the Refraction. — Method of Ackermann and Foggenburg. — Determine the refraction of the liquor at 17.5° C. by means of the immersion refractometer. Determine also the refraction of the dis- tillate from 100 cc. of the hquor at 17.5° C. after making up to its original volume. In order to secure accurate results, care should be taken to cool the prism of the instrument to exactly 17.5° C. by immersing for five minutes in the water-bath previous to taking the refraction of the liquids. If determinations are made on a number of samples, this cooling is not necessary except before taking the reading of the first of the series. Calculate the grams of extract (£) from the refraction of the liquor {R) and of the distillate {R') by the following formula; E = o.2Slos{R-R'). The extract is more conveniently obtained from Ackermann's table given on p. 721. Original Gravity of Beer Wort and its Determination. — Following a long-established custom of the EngHsh excise, the duty on beer has been based on the specific gravity of the original wort, by which is meant the wort of the beer before any of its sugar has been lost by fermentation. From the content of alcohol in the beer the sugar originally present in the wort may be calculated, assuming that the alcohol amounts to about half the sugar used up in fermentation. Obtain the specific gravity of the beer, dealcoholized and made up to its original volume, as in the calculation of the extract. This is called the "extract gravity." Note the specific gravity correspond- ing to the alcohol found, i.e., the specific gravity of the distillate in the alcohol determination, when made up to the original volume, and subtract this from i. The difference is known arbitrarily as the "degree of spirit indication." From the table of Graham, Hofmann, and Redwood,* p. 723, the "degrees of gravity lost" corresponding to the "spirit indication * Report on Original Gravities, 1852; Allen's Com. Org ^al., 4 Ed., Vol. I, p. 151. ii< ALCOHOLIC BEVERAGES. 723 ■are ascertained. This figure is added to the "extract gravity" to find the "original gravity of the wort." SUGAR USED UP IN FERMENTATION. Degrees of ' 'Spirit In- dication ' ' {(. 0000 o.oooi c .0002 0.0003 0.0004 0.000s 0.0006 0.0007 0.0008 0.0009 0.000 . 0003 .0006 0.0009 0.0012 0.0015 0.0018 0.0021 0.0024 0.0027 .001 .0030 -0033 0037 .0041 .0044 .0048 .0051 ■0055 .0059 .0062 .002 .0066 .0070 0074 .0078 .0082 .0086 .0090 .0094 .9098 .0102 .003 .0107 -OIII OII5 .0120 .0124 .0129 ■0133 .0138 .0142 -0147 .004 .0151 ■0155 0160 .0164 .0168 .0173 .0177 .0182 .0186 .0191 ,005 .0195 .0199 0204 .0209 .0213 .0218 .0222 .0227 .0231 .0236 .006 .0241 -0245 0250 -.0255 .0260 .0264 .0269 .0274 .0278 •02S3 .007 .0288 .0292 0297 .0302 .0307 .0312 -0317 .0322 ■0327 ■^332 -008 -0337 -0343 0348 •0354 ■0359 •0365 .0370 -0375 .0380 .0386 -009 .0391 -0397 0402 .0407 .0412 .0417 .0422 .0427 .0432 •0437 .OIQ .0442 -0447 0451 •0456. .0460 .0465 .0476 -0475 .04S0 .0485 -Oil .0490 .0496 0501 .0506 .0512 ■0517 .0522 .0527 ■0533 ■0533 .012 -0543 .0549 ^\$^ -0559 .0564 .0569 -0574 ■0579 .0584 .0589 -013 ■0594 .0600 0605 .0611 .0616 .0622 .0627 -0633 .0638 .0643 .014 .0648 .0654 0659 .0665 .0471 .0676 .0682 .0687 .0693 .0699 -015 .0705 .0711 0717 .0723 .0729 -0735 .0741 -0747 -0753 -0759 Example. — Suppose the "extract gravity" is 1.0389 and the specific gravity of the alcoholic distillate is 0.9902, both at 15.6. Then i —0.9902 = 0.0098, the "degree of spirit indication." From the above table the cor- responding "degree of gravity lost" is found to be 0.0432. 0.0432+1.0389 = 1.0821, the original gravity of the wort. The calculation in the above simplified form is accurate for normal beer wherein the free acid present, expressed as acetic, does not exceed 0.1%. In case of beer that has developed free acid much in excess of the above limit, a correction should be added to the degrees of spirit indication. This correction, which in practice it is rarely necessary to apply except in extreme cases of old or sour beer, is calculated as follows: If a represents the grams of free acid (as acetic) in 100 cc, then the correction to be added to the spirit indication =o.ooi3a — 0.00014. Example. — Supposing the "extract gravity" to be. 1.0413, the specific gravity of the alcoholic distillate to be 0.9890, and the free acid as acetic to be 0.35%. Then 1—0.989=0.0110, the degree of spirit indication. 0.35X0.0013—0.00014=0.0003, correction to be added to the spirit indication. 0.0110+0.0003=0.0113, corrected spirit indication. 724 FOOD INSPECTION y^ND ^N^ LYSIS. From the above table the corresponding degrees of gravity lost are 0.0506: 0.0506+ 1.0413= 1. 0919, the original gravity of the wort. Determination of Degree of Fermentation.— This is calculated by 200^ the formula D = — z— -, in which Z) = degree of fermentation, ^ = per cent Jo of alcohol by weight, and B = ihc original extract. Determination of Reducing Sugars. — Dealcoholize 25 cc. of the beer and make up to 100 cc. Determine reducing sugars by the Defren- O'SuUivan or Munson-Walker method, and calculate as maltose. Determination of Dextrin. — Dilute 50 cc. of the beer to 200 cc, hydrohze by heating in a boiling water-bath for 2^ hours with 20 cc. of hydrochloric acid (speciiic gravity 1.125), nearly neutralize the free acid with sodium hydroxide, make up to 300 cc, filter, and determine the dextrose by copper reduction. Multiply the amount of reducing sugars as maltose by 0.95, subtract this from the dextrose, and multiply the difference by 0.9, thus obtaining the dextrin in the b:cr Determination of Glycerin. — Proceed as directed on page 703 under wine. The milk of lime is added during evaporation after the carbon dioxide has been expelled. It is advisable that the filtrate, after being evaporated to a syrupy consistency, be treated again with 5 cc. of absolute alcohol and two portions of 7.5 cc. each of absolute ether. If clear, continue as directed. If not clear, it is necessary to repeat the treatment with lime. Determination of Total, Fixed, and Volatile Acids. — A measured volume of the beer, say 10 cc, is freed from carbon dioxide by bringing to boiling. It is then cooled and titrated with tenth-normal sodium hydroxide, using neutral litmus solution as an indicator. Each cubic centimeter of tenth-normal alkali is equivalent to 0.009 gram of lactic acid, in which the total acidity is usually expressed. Fixed acid, also expressed as lactic, though small quantities of suc- cinic, tannic, and malic acids are usually also present, is determined as follows: Dealcoholize a measured amount of the beer, say 10 cc, by evaporation to one-fourth its volume, dilute with v/ater to the original volume, and titrate with tenth-normal alkali, as before. Volatile acid is expressed as acetic, and is usually calculated by dif- ference between total and fixed acid. Each cubic centimeter of tenth- normal alkali is the equivalent of 0.006 gram acetic acid. ALCOHOLIC BEyERAGES. 725 Detsrmination of Proteins.— Fifty cc. of the beer are first treated wiih 5 cc. of dilute sulphuric acid, and concentrated by boiling to syrupy consistency. Then proceed by the Gunning method, p. 69. Nx6.25 = proteins. Determination of Phosphoric Acid. — Unless the sample is very dark- colored, sufficiently close results can usually be obtained by direct titra- tion of the beer itself with uranium acetate solution. For very accurate results the ash should be used. Prepare a solution of uranium acetate of such strength that 20 cc. will correspond to o.i gram P^Og. This solution is best standardized against pure, crystallized, uneffloresced, powdered hydrogen sodium phosphate, 10.085 grams of which are dissolved in water and made up to a liter. 50 cc. of this solution contains o.i gram phosphoric anhydride, if the salt is pure. If the solution is of proper strength^ 50 cc. evaporated to dr^^ness and ignited in a tared platinum dish should have an ash weighing 0.1874 gram. For preliminary' trial about 35 grams of uranium acetate arc dissolved in water, 25 cc. of glacial acetic acid, or its equivalent in weaker acid added, and the solution made up to a liter with water. To standardize, 50 cc. of the standard phosphate solution prepared. as above are heated to 90° or 100° C, and the uranium solution nm in. from a burette till the resulting precipitate of hydrogen uranium phos- phate is complete. The end-point is determined by transferring a few drops of the solution to a porcelain plate, and touching with a drop of freshly prepared potassium ferrocyanide solution. When the slightest excess of uranium acetate has been added, a reddish-brown color is pro- duced by the ferrocyanide. The uranium acetate solution is purposely made rather stronger than necessar}^ at first, and by repeated trials is brought by dilution with water to the required strength (20 cc. equivalent to 50 cc. of the phosphate solution). Fifty cc. of the beer are heated to 90° or 100° C. and titrated with the uranium acetate solution under the same conditions and in precisely the same manner as when standardizing that solution. Each cubic centi- meter of the uranium acetate corresponds to 0.01% of P2O5. For the phosphoric acid determination in the ash, 50 cc. of the beer are incinerated in the regular manner, and the ash moistened with con- centrated hydrochloric acid. The acid is then evaporated off on the water-bath, after which the ash is boiled with 50 cc. of distilled watc*, and titrated Avith the standard uranium solution. 72 3 FOOD INSPECTION AND ANALYSIS. Determination of Carbon Dioxide.* — In the case of beer and other ■carbonated drinks put up in corked bottles, the carbon dioxide may be readily determined by piercing the cork with a metal champagne tap, which is connected by a flexible tube, first with a safety flask and then with an absorption apparatus somewhat after the style of that used in the determination of carbon dioxide in baking powder, the liberated .carbon dioxide being absorbed for weighing in a concentrated solution of potassium hydroxide contained in .a tared Liebig bulb. The beer- bottle thus connected is immersed in a vessel of water, which is heated over a gas-flame, after all the carbon dioxide that will escape spontaneously has been allowed to do so. Before weighing the absorbed carbon dioxide, the beer-bottle is replaced by a soda-lime tube, and a current of air drawn through the tubes. Beer and ale put up in bottles having patent metallic or rubber stoppers cannot thus be treated. In this case a measured quantity, say 200 cc, of the sample is transferred as quickly as possible to a large flask pro- vided with an outlet-tube having a glass stopper, this being connected up with the safety-flask and absorption-tubes. In this case, heat may be directly, though cautiously, applied to the flask containing the beer by means of a gas-flame, after all the carbon dioxide has gone over that will do so spontaneously. Exactly the same apparatus as that shown in Fig. 71 may be used to advantage for determination of carbon dioxide in beer, except that a larger distilling-flask should be used in the case of beer. Detection of Bitter Principles. — Elaborate schemes have been worked out for the systematic treatment of beer and ale for bitter principles. Nearly all of these are complicated and somewhat unsatisfactory. The presence -of alkaloids in malt liquors, deliberately introduced during the process •of manufacture, is now so rare that the analyst need seldom look for them, except in cases of suspected poisoning, when the scheme of Dragendorff or of Otto-Stas should be employed. While it is somewhat difficult to positively identify the various alkaloids, it is usually easy to prove their absence in clear solutions, if on treatment with either of the general alkaloidal reagents, Mayer's solution (Reagent No. 170), or iodine in potas- sium iodide (Reagent No. 143), no precipitate is formed. It is comparatively easy to prove the mere presence or absence of hop substitutes. The bitter principle of hops is readily soluble in ether, when a sample of the beer evaporated to syrupy consistency is extracted * U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 95; Bui. 107 (rev.), p. 92. t Gerichtlich-Chemische Ermittelung von Giften, St. Petersburg, 1876. ALCOHOLIC BEVERAGES. 727 therewith, while the bitters of quassia and aloes, common hop substitutes, -are insoluble in ether. Though many varieties of bitters might be em- ployed that are soluble in ether, the absence of a bitter taste from the ether extract is evidence of the absence of hops. The most markcfl difference analytically between hops and their substitutes in malt liquors lies in the fact that the bitter principle of hops is completely precipitated therefrom by treatment of the beer with lead acetate (either basic or neutral), leaving no bitter taste in the filtrate after- concentration, while if any of the hop substitutes are present, the concentrated filtrate from the lead acetate treatment will have a bitter taste. The excess of lead should be removed from the filtrate, before concentration and tasting, by treatment with hydrogen sulphide. If the residue from the ether or chloroform extraction of the concentrated filtrate from a beer after treatment with lead acetate be found to be bitter, there is positive evidence that a foreign substitute has been employed. The following are characteristic reactions that may help to identify some of the common hop substitutes.* Quassiin is readily soluble by chloroform from acid solution. If a residue containing quassiin be moistened with a weak alcoholic solution •of ferric chloride and gently heated, a marked mahogany-brown color- ation is produced. On treatment of quassiin with bromine and sodium hydroxide or .ammonia, a bright-yellow color is shown. Chiretia is readily dissolved by ether from its aqueous solution. Its •ether residue, when treated with bromine and ammonia, gives a straw -color, slowly changing to a dull purple-brown. This is not true of its chloroform residue, so that it is not to be mistaken for quassia (Allen). Gentian Bitter may be extracted by treatment of the acid liquor with -chloroform. When the residue containing gentian bitter is treated with concentrated sulphuric acid in the cold, no color is produced, but on warming gently a carmine-red color is shown; if further treated with ferric chloride solution, a green-brown color is formed. Aloes. — ^This substance is separated from beer by treating the dried residue from 200 cc. of the beer with warm ammonia, filtering, cooling, and treating the filtrate with hydrochloric acid. The resin of aloes is precipitated and collected on a filter. It is insoluble in cold water, ether, * Allen, Analyst, 12, 1887, p. 107. 728 FOOD INSPECTION ^ND AN /I LYSIS. chloroform, or petroleum ether, but is soluble in alcohol. It has a very- characteristic odor, which serves to identify it. The hot-water solution gives a curdy precipitate on treatment with lead acetate. Capsicin is extracted by treatment of the acid liquor with chloroform. It is recognizable by its sharp, pungent taste. Detection of Arsenic. — By the Marsh Method. — Measure loo cc. of the beer (freed from carbon dioxide by agitation) into a seven-inch porce- lain evaporating-dish, add 20 cc. pure concentrated nitric acid, and 3 cc. pure concentrated sulphuric acid, and cautiously heat till vigorous chemi- cal action sets in, accompanied by frothing and swelling of the beer. Turn the flame low or remove it altogether, and stir vigorously till the frothing ceases, after which the liquid may be boiled freely. At this stage transfer to a large casserole, and continue the boiling till nearly all the nitric acid is driven off. Then, holding the casserole by the handle, continue the heating till the mass chars and the fumes of sulphuric acid are given off, giving the casserole a rotary motion to prevent sputtering. The residue should be reduced to a dry, black, pulverulent char soon after the sulphuric acid fumes begin to come off freely. If still liquid, pieces of filter-paper should be stirred in while still heating, till the residue is d.r)\ avoiding an excess of paper. Cool, add 50 cc. of water, and remove the masses of char from the sides of the dish by the stirring-rod. Heat to boiling and filter. Use the filtrate for the Marsh apparatus, adding it gradually. The arsenic mirror may be weighed in the usual manner, if of suffi- cient size. Reinsch's Test.* — Two hundred cc. of the beer are acidified with i cc. of pure, concentrated, arsenic-free hydrochloric acid, and evaporated to half its volume. 15 cc. more of hydrochloric acid are then added, and a piece of pure burnished copper foil half an inch long and a quarter of an inch wide is immersed in the liquid and kept in it for an hour while simmering, replacing from time to time the water lost by evaporation. If after the lapse of an hour the copper still remains bright, no arsenic is present. If the copper shows a deposit, remove, wash with water, alcohol, and ether, and diy. Then place the copper in a subliming-tube, and heat over a low flame. Tetrahedral crystals, apparent under the microscope,, show the presence of arsenic. Blackening of the copper does not in itself prove arsenic. * Jour. Soc, Chem Ind., 20, p. 646. ALCOHOLIC BEl^ERAGES. 72) Detection and Determination of Preservatives. — See Chapter XVITI. Sulphurous acid may be determined by direct titration, as in the case of wine. MALT EXTRACT. True malt extract is a syrupy tluid having a specific gravity of from 1.3 to 1.6, and made up in accordance with the following directions of the 1880 Pharmacopoeia: Upon 100 parts of coarsely powdered malt contained in a suitable vessel, pour 100 parts of water, and macerate for six hours. Then add 400 parts of water, heated to about 30° C. and digest for an hour at a temperature not exceeding 55° C. Strain the mixture with strong pressure. Finally, by means of a water-bath or vacuum apparatus, at a temperature not exceeding 55° C, evaporate the strained liquid rapidly to the consistence of thick honey. Keep the product in well-closed vessels in a cool place. Such an extract has a residue of at least 70%, consisting chiefly of maltose, and contains about 2% of diastase. It should furthermore be capable of converting its own weight of starch at 55° C. in less than ten minutes. The following are analyses of three samples of pure malt extract:* 9.0 1-387 1. 421 1.498 72-31 76.65 .231 ■ 275 79.8rb.386 S.^ 0-0333.329 021 3. 116 0-0534-872 62.52 65.41 61.32 S-2£ 6.94 12.39 o'o I. 21 0.483 I. 19 0.556 1.23 0.428 Diastatic Action. Complete in less than 5 min. There are on the market many so-called malt extracts widely advertised for their tonic and medicinal virtues, having the taste and consistency of beer or ale. In fact they are virtually beer, differing therefrom mainly in respect to price. Such "malt extracts" have no diastase, and their value as nutrients depends almost entirely on their sugar content. Harrington t has analyzed twenty-one of the best known of these alleged malt extracts, the maximum, minimum, and mean results of his analyses being as follows: * Penn. Dept. of Agric. An. Rep., 1898, p. 85. t Boston Medical and Surgical Journal, Dec. 31, 1896. 730 FOOD INSPECTION AND ANALYSIS. Specific Alcohol. Gravity. Total Residue. Ash. I -0555 I. 0149 7-13 0.74 3-94 13-63 5-13 8.78 0-53 0.20 Minimum = Mean None of them contained any diastase, . and several were preserved with salicylic acid. DISTILLED LIQUORS. These beverages differ from those hitherto considered, by reason of their high alcoholic content and low extract or residue. Indeed, when first distilled they are entirely without residue, but from long storage in casks, they absorb certain extractives from the wood, that impart more or less flavor as well as color. When any fermented alcoholic infusion is subjected to distillation under ordinary circumstances, a distillate results which consists of a mixture with water of a large number of alcohols, chief among which is ethyl alcohol. The high boiling alcohols — amyl, butyl, propyl, etc.^ with their esters — exist in the distillate in small amount, constituting what is known as fusel oil. The various distilled liquors of commerce are made by just such a process of distillation, the product var^-ing widely in flavor and character with the basis from which it was distilled. The so-called pot-still (the old-fashioned copper still and worm) is well adapted for the production of potable spirits such as whiskey^ brandy, gin, and rum, as these products should contain the congeneric substances which give the liquors their special character; it is not, however, suited for the manufacture of pure alcohol, because repeated distillation would be required for purification. Now, however, by the use of improved apparatus, such as the Coffey still, involving the principle of fractional condensation, it is possible to obtain what is known as " silent spirit," or ethyl alcohol, free from fusel oil. With proper appurtenances for rectifying, one can now obtain 95% alcohol by two distillations. Standards for Spirits.^The following are the standards adopted by the Joint Committee of the Association of Official Agricultural Chemists and the Association of State and National Food and Dairy Departments: Distilled Spirit is the distillate obtained f'-om a fermented mash of cereals, molasses, sugars, fruits, or other fermentable substance, and ALCOHOLIC BEVERAGES. 731 contains all the volatile flavors, essential oils, and other substances derived directly from the material used, and the higher alcohols, ethers, acids, and other volatile bodies congeneric with ethyl alcohol produced during fermentation, which are carried over at the ordinary tempera- ture of distillation, and the principal part of which are higher alcohols estimated as amylic. Alcohol, Cologne Spirit, Neutral Spirit, Velvet Spirit, or Silent Spirit,. is distilled spirit from which all, or practically all, of its constituents, except ethyl alcohol and water, are separated, and contains not less than. 94.9% (189.8 proof) by volume of ethyl alcohol. Composition of Fusel Oil. — Fusel oil varies considerably in compo- sition with the source from which it is derived. Amyl alcohol, being. in all cases its chief constituent, is frequently known commercially as fusel oil. _ The alcohols found in fusel oil with their formulas, specific gravity, and boiling-points are as follows: Formula. Specific Gravity. Boiling-point. Ethyl alcohol. Propyl ' ' Butyl " . Amvl ' ' Hexvl " . C2H5OH C.H^OH C.HgOH CH„OH cIh^oh ■794 .820 .803 .811 78.4° C. 97° C. 115° C. 130° c. The following acids have been found in fusel oil, usually combined with the alcohols to form compound ethers: Acetic HC2H3O2 Propionic HC3H5O2 Butyric HC.H.O, Valerianic HC5H9O2 Caproic HCgHnOa (Enanthylic HC;Hi302 Caprylic HCsHi^Oa Pelargonic HCaHi^Oj Aging. — Freshly distilled liquors all contain notable quantities of fusel oil, which renders them harsh and unfit for use, but by the process- of aging, they become in several years mellow and palatable. The chemi- cal changes which take place during aging are discussed under whiskey. WHISKEY. Process of Manufacture. — Whiskey is the liquor resulting from the distillation of a fermented infusion of grain, the process being carried out in a pot-still, or some other form of still, constructed so that the resulting liquor contains not only the alcohol, but also the greater part 732 FOOD INSPECTION AND ANALYSIS. of the congeneric substances which are vaporized with the alcohol. The fermented infusion known as the " mash" is obtained by steeping in water the starch-containing material, usually barley, rye, corn (maize), or oats mixed with malt, and subjecting the mixture to the action of the diastase contained in the malt, in much the same manner as the mashing process in the brewing of beer, except that for whiskey the process of saccharous fermentation is carried further, with a view to obtaining a maximum yield of maltose and a minimum of dextrin. Yeast is afterwards added, and alcoholic fermentation allowed to proceed "with proper precautions. The fermented wort from whatever source obtained is subjected to distillation, purposely avoiding rectification or separation of the fusel oil and other congeneric substances which are valuable as flavors. The product of the first distillation is called "low wines," and is redistilled; the product of the second distillation is commonly divided into three fractions, of which the middle portion, or " clean spirit " is retained for the whiskey, while the first (" foreshots ") and the last fraction ("faints") are mixed with the next portion of low wine to be redistilled. If the whiskey is too high in alcohol, it is diluted to the proper strength. As new whiskey is crude and harsh in taste, it is subjected to " aging," or storing in casks for a number of years. The aging process softens and refines the flavor, but recent investigations have proved that this is not due, as formerly believed, to transformation of fusel oil into esters, although the esters increase in amount during aging, as do also the acids — especially the volatile acids — the aldehydes, and the furfural. As a matter of fact, the percentage of fusel oil increases instead of diminishes on aging, due to the evaporation of water and, in a lesser degree, of alcohol through the wood; the actual amount, however, remains prac- tically the same as at the start (see table, p. 737). When first distilled, whiskey is perfectly colorless, but during the aging it extracts more or less color and some flavor from the casks in which it is stored. This color is especially pronounced in American whiskies, owing to the pre- vailing custom of charring the inside of the cask. Its flavor varies considerably with the nature of the grain used in its preparation. U. S. Rulings, — The following decision of President Roosevelt, based on an opinion of Attorney-General Bonaparte, was promulgated by Sec- retary Wilson, April 11, 1907:* * This decision has been overruled by President Taft, whose opinion is the basis of Food Inspection Decision No. 113 (Feb. 16, 1910), signed by the secretaries of the Treasury, Agri- culture, and Commerce and Labor. The chief points of this decision follow: ALCOHOLIC BEyERAGES. 733 " Straight whiskey will be labeled as such. '' A mixture of two or more straight whiskies will be labeled ' blended whiskey,' or ' whiskies.' " A mixture of straight whiskey and ethyl alcohol, provided that there is a sufficient amount of straight whiskey to make it genuinely a ' mixture/ will be labeled as compound of, or compounded with, pure grain distillate. " Imitation whiskey will be labeled as such." Joint Standards. — The following are the standards of the Joint Com- mittee of the A. O. A. C. and the A. S. N. F. D. D. : New Whiskey is the properly distilled spirit from the properly pre- pared and properly fermented mash of malted grain, or of grain the starch of which has been hydrolyzed by malt; it has an alcoholic strength corresponding to the excise laws of the various countries in which it is produced, and contains in 100 liters of proof spirit not less than 100 grams of the various substances other than ethyl alcohol derived from the grain from which it is made, and of those produced during fermentation, the principal part of which consists of higher alcohols estimated as amylic. Whiskey {Potable Whiskey) is new whiskey which has been stored in wood not less than four years without any artificial heat save that which may be imparted by warming the storehouse to the usual tem- perature, and contains in 100 liters of proof spirit not less than 200 grams of the substances found in new whiskey, save as they ar3 changed or eliminated by storage, and of those produced as secondary bodies during aging; and, in addition thereto, the substances extracted from the casks in which it has been stored. It contains, when prepared for consumption All unmixed distilled spirits from grain, colored and llavored with harmless color and flavor, in the customary ways, either by the charred barrel process, or by the addition of caramel and harmless flavor, if of potable strength and not less than 80° proof, are entitled to the name whiskey without qualification. Whiskies of the same or different kinds (i.e., straight, rectified, redistilled, and neutral spirits whiskies) are like substances and mixtures of such, with or without harmless color or flavor used for purposes of coloring and flavoring only, are blends. Potable alcoholic distillates from sources other than grain (e.g., cane, fruit, or vegetables), colored and flavored, are imitations and mixtures of such with grain distillate are com- pounds. A distillate of grain (e.g., corn) flavored to simulate a whiskey of another kind (e.g., rye) is an imitation of that whiskey. Attorney-General Wickersham (F. I. D. No. 127) has further decided that the name "Canadian Club whiskey" is distinctive and it is therefore unnecessary- to place the word "blend" on the label. 734 FOOD INSPECTION AND ANALYSIS. as permitted by the regulations of the Bureau of Internal Revenue, not less than 45% by volume of ethyl alcohol, and, if no statement is made concerning its alcoholic strength, it contains not less than 50% of ethyl alcohol by volume, as prescribed by law. Rye Whiskey is a whiskey in the manufacture of which rye, either in a malted condition or with sufficient barley or rye malt to hydrolyze the starch, is the only grain used. Bourbon Whiskey is a whiskey made in Kentucky from a mash of Indian corn and rye, and barley malt, of which Indian corn forms more than 50%. Corn Whiskey is whiskey made from malted Indian corn or of Indian corn the starch of which has been hydrolyzed by barley malt. Blended Whiskey is a mixture of two or more whiskies. Scotch Whiskey is whiskey made in Scotland solely from barley malt, in the drying of which peat has been used. It contains in 100 liters of proof spirit not less than 150 grams of the various substances prescribed for whiskey exclusive of those extracted from the cask. Irish Whiskey is whiskey made in Ireland, and conforms in the proportions of its various ingredients to Scotch whiskey, save that it may be made of the same materials as prescribed for whiskey, and the malt used is not dried over peat. U. S. P. Standards. — The requirements for whiskey are as follows: It should be at least two years old; in specific gravity it should lie between the limits of 0.945 and 0.924; its alcoholic content should be not less than 37% nor more than 47.5% by weight; the residue from 100 cc. should be not more than 0.5 gram, which should be neither sweet nor spicy, should dissolve in 10 cc. of cold water, and this solution should be colored only a pale green when treated with a drop of very dilute ferric chloride solution (a deeper color would indicate more than traces of tannin). In evaporating the liquor on the water-bath for the residue,, the last traces volatilized should have an agreeable odor free from harsh- ness, indicative of the absence of fusel oil. Its reaction should be slightly acid, but not more than 1.2 cc. of normal alkali should be required to neutralize 100 cc. of the liquor, using litmus as an indicator. If 50 cc. are shaken vigorously with 25 grams of kaolin, allowed to stand an hour and filtered, the color of the filtrate should not be much lighter than before treatment. Composition. — Whiskey consists chiefly of alcohol and water, with relatively small amounts of fusel oil, acids, esters, aldehydes, and fur- ALCOHOLIC BEyER/lGES. 735 fural. Its extract, derived mainly from the casks in which it is stored, should consist only of small amounts of tannin, sugar, and coloring matter. British Whiskies. — Scotch and Irish whiskies are aged in uncharred barrels, hence they are of a lighter color than the American product. Scotch whiskey is further characterized by its smoky taste, due to the peat over which it is dried. The following analyses by Vasey * illustrate the composition of Scotch and Irish whiskey of different ages, of neutral spirits used in compounding (" blending ") and adulterating, and of the compounded liquors: Grams per loo Liters. Volatile Acids. Esters. Alde- hydes. Furfural. Fusel Oil. Pot-still Scotch whiskey, 8 years old . Pot-still Scotch whiskey, 25 years old Irish whiskey, new Irish whiskey, 7 years old Neutral spirit for "blending" " Blended " Scotch "Scotch," probably all neutral spirits 48.0 64.8 20.9 41.8 8.4 39-1 16.8 89.7 125. 1 7-7 20.9 23.8 106.8 8.2 14.2 66.1 6.5 II. 2 4-9 14-3 lO.O 200.0 180.0 174.0 204.0 trace 108.5 none It will be noted that the congeneric substances in whiskey increase on aging, although in the case of fusel oil this apparent increase is doubtless due merely to concentration dependent on evaporation. The sample of neutral spirits contained only small amounts of the congeneric substances, while the " blended " whiskies were deficient in most of these substances. American Whiskies. — These have a deeper color than the British whiskies (due to the charred barrel) and a rich fruity flavor without the suggestion of smoke. In the table on p. 736 are given analyses by Shepard f of fourteen leading brands, including both rye and bourbon, varying in age from four to eight years; also of two samples of neutral spirits used for com- pounding and adulterating. A summary of the results obtained by Crampton and Tolman \ in the analysis of fourteen brands of rye and seventeen brands of bourbon whiskey at differing stages of aging appear in the table on page 737. The barrels were kept in U. S. bonded warehouses during aging, and samples * Potable Spirits, pp. 82, 83, and 87. t The Constants of Whiskey, S. Dak. Food and Dairy Commission, March, 1906. X Jour. Am. Chem. Soc, 30, 1908, p. 98. 736 FOOD INSPECTION AND ANALYSIS. Rye Bourbon Standard Hand-made sour mash Hand-made sour mash Hand-made sour mash, Bourbon Special reserve Sour mash .' . . Neutral spirits. 5 4i 4 4 6 6 7 Sh 7 5 lh 4 4) g ■9 Grams per loo Liters. W 189 181 160 162 148 132 138 153 180 129 212 124 177 139 -3 Acids. 92.0 68.4 66.8 67.1 62.4 49.2 74.8 58.8 74-4 60.9 93-0 58.2 66.=; 12.8 9-3 10. 2 10.2 7-5 7-5 8.6 9-9 9-9 7-2 13-5 7-2 9.0 6-3 1.2 1.4 79-2 59-1 56.6 56.9 54-9 41.7 66.2 48.9 64-5 53-7 79-5 51-0 57-5 44-0 6.3 4-9 81.8 60.7 55-9 74-8 55-9 39-6 61.6 69.6 70.8 49-3 94.0 64.0 76.6 54-6 15-4 64.2 17-5 17-5 10. o I-C.O 15-0 8.C 10.5 14.0 12-5 9-5 22.5 9-5 10. o 7-5 2.5 3-0 3-2 2-4 2.6 2.6 1 .0 1-3 0.7 2.5 0.8 5-0 0.5 1-7 1-5 84-9 102.6 160.4 130.9 152.0 107.4 192.7 I37-I 117. o 141. 7 "9-5 95-3 193.6 152.0 30.0 39-6 were withdrawn at intervals of a year for eight years. As the minimum figures for certain constituents are abnormal, the next to the minimum figures are also given. It will be noted that during the first few years there was a marked increase in actual amounts of all the constituents determined, except fusel oil, over and above that due to concentration, but after three or four years the acids and esters do not materially change. The rye whiskies contained larger amounts of solids, acids, esters, etc., than the bourbons, but this was attributed to the fact that heated warehouses are used for rye, and unhealed for bourbon whiskey. The authors state that the characteristic aroma of American whiskey, also the oily appearance and the " body " (solids), are due to the charred barrels. Thirty-seven samples of whiskey, purchased by the glass from various Massachusetts saloons, were examined by the Massachusetts State Board of Health in 1894, with the following results: Per Cent i p p . Alcohol by 1 ^^'15^'J* Weight. j Extract. Maximum 45.96 1.68 30.70 1 0.08 36-51 1 0-50 Minimum Mean ALCOHOLIC BEVERAGES. 737 SUMMARY OF ANALYSES OF AMERICAN WHISKIES OF DIFFERENT AGES Proof. Grams per 100 Liters of 100 Proof Spirits. Color Extract. Acids. Esters. .\lde- hydes. Fur- fural. Fusel Oil. RvE Whiskey. New: Average . .. 101.2 0.0 13.3 4.4 16.3 5.4 1.0 90.4 Maximum . I02.0 0.0 30.0 72.0 21.8 I5-0 1.9 161. 8 Minimum * lOO.O 0.0 5-0 12.0 4-3 0.7 trace f 61.8 I 43-7 One year old: .\verage . .. 102.5 8.8 119.7 46.6 37.0 7.0 1.8 111.5 Maximum . 104.0 13.8 171. 60.5 64.8 15-5 i-i 194.0 Minimum * lOI.O / 7-- \ 6.6 93-0 92.0 31-1 5-8 6.8 \ 6.8/ 2.8 0.4 / 80.4 I 66.4 Two years old: Average . .. 104.9 11.6 144.7 51.9 54.0 10.5 2.2 112.4 Maximum . 109.0 16.7 199.0 75-6 75-1 18.7 5-7 214.0 Minimum * 100. / 8.8 \ 8.6 121. 44-3 41. 5\ 5-4 0.7 / 83.4 1 82.2 94.0 II. 31-2/ Three years old .Average . .. 107.7 13.2 171.4 62.7 61.5 12.5 1.5 112.7 Maximum . 112.0 18.3 224.0 81.8 79-8 20.8 6.1 202.0 Minimum * 104.0 \ 10. 1 145-0 52.3 16.4 47-61 6-5 0.7 ( P-° 119. 34-3 J \ 60.0 Four years old: .\verage . . . 111.2 14.0 185.0 65.9 69.3 13.9 2.8 125.1 Maximum . 118. 18.9 238.0 83.8 89.1 22.1 6.7 203-5 Minimum * 105.0 rii.6 156.0 58.6 57-7\ 36.3/ 6.4 0.7 r 83.8 l"-3 153-0 17-3 I 67.8 Eight years old : Average . .. 123.8 18.6 256.0 82.9 89.1 16.0 3.4 154.2 Maximum . 132.0 24.2 339-0 112. 126.6 26.5 9-2 280.3 Minimum * 112. /13-8 214.0 73-7 68.4 1 7-9 0.8 f 109.0 \13-7 200.0 31-7 40.9/ 1 107-1 Bourbon Whiskey. New: Average . .. 101.0 0.0 26.5 10.0 18. 4 3.2 0.7 100.9 Maximum . 104.0 0.0 161. 29.1 53-2 7-9 2.0 171-3 Minimum * 100. 0.0 4.0 12.0 13-0 I.O trace / 71-3 I 42.0 110.1 One year old: .\verage . .. 101.8 7.1 99.6 41.1 28.6 5.8 1.6 Maximum . 103.0 10.9 193.0 55-3 55-9 8.6 7-9 173-4 Minimum * 100. / 5-4 I 4-6 61 .0 24-7 17. 2I 2-7 trace ( ^^-l 54-0 7.2 10.4/ I 42.8 Two years old : Average . .. 102.2 8.6 126.8 45.6 40.0 8.4 1.6 108.9 Maximum . 104.0 II. 8 214.0 61.7 59-8 12.0 9-1 197. 1 Minimum * f '■' 81.0 25-5 24.4 1 f 86.2 100. 78.0 5-9 0.4 \ Q I 5-7 23-3 II. 2 J I 42.8 Three years old .\verage . .. 103.0 10.0 149.3 54.3 48.1 10.5 1.7 112.4 Maximum . 106.0 13.8 245.0 64.8 73-0 22.1 9-5 221.8 Minimum.* 100. / 8.9 95-0 38.4 27. 21 5-9 0.6 r 88.0 I 7-0 90.0 32.1 12. 1 J I 43-5 Four years old : Average . .. 104. i 10.8 151.9 58.4 53.5 11.0 1.9 123.9 Maximum . 108.0 14.8 249.0 73-0 80.6 22.0 9.6 237-1 Minimum * 100. r 8.6 lOI.O 40.4 . 28.2 1 13-8/ 6.9 0.8 / 95-0 I 7-4 92.0 40.4 I 43-5 Eight years old: Average . .. 111.1 14.2 210.3 76.4 65.6 12.9 2.1 143.5 Maximum . 124.0 20.9 326.0 91.4 93-6 28.8 10. 241.8 Minimum * 102.0 / 12.3 152.0 64.1 37-7\ 8.7 1 .0 jiio.a I 10-5 141. 53-7 22.1 J I 47-6 * Minimum and next to the minimum. '/ 738 FOOD INSPECTION AND ANALYSIS. Seven of these samples had an excess of tannic acid, three had no tannic acid at all, and two or three had insoluble residues. Adulteration of Whiskey. — Imitation whiskey is often concocted by diluting alcohol or neutral spirit to the proper strength, coloring with caramel, sometimes adding for body prune juice, and adding for flavor certain essential oils, such as oil of wintergreen, and artificial fruit essences, such as oenanthic and pelargonic ethers. As a rule, a small amount of pure whiskey is mixed with the artificial to give it flavor. What has long been known as " blended whiskey " is either an imitation pure and simple, or a compound of whiskey and neutral spirits, artificially colored and flavored. According to the U. S. decisions, the term " blended whiskey " is restricted to a mixture of different kinds of genuine whiskey, colored and flavored. Among Fleischman's recipes for " blended " whiskey is the following, which he claims to be the very lowest grade: Spirits 32 gallons Water 16 Caramel 4 ounces Beading oil i ounce "Beading oil" is prepared by mixing 48 ounces oil of sweet almonds with 12 ounces C. P. sulphuric acid, neutralizing with ammonia, adding double the volume of proof spirits, and distilling. This preparation is so called because it is largely used for putting an artificial bead on cheap liquors. A little creosote is sometimes added to give a burnt taste in sem- blance of Scotch whiskey. Pungent materials such as cayenne pepper are said to be used as adulterants, but no record is known of any substance being used more injurious than the alcohols. Sugar is a frequent adul- terant. Some doubt exists as to the injurious effects of fusel oil on the system. The following analyses by Ladd * show the composition of neutral spirits, and imitation whiskey consisting of neutral spirits diluted with water, colored with caramel and flavored: * N. Dak. Agric. Exp. Sta. Rep., 1906, Part II, p. 145. ALCOHOLIC BEVERAGES. 739 >. C o h 0.2 < Grams per 100 Liters. 1 < Acids. •s •a < ■5 u 3. 3 13 X 1 3 Neutral spirits 94.0 40.1 45-8 45-0 2.4 366. 4t 854. of 456. of 0.0 4-4 2.0 5-5 7-2 43-2 20.4 9.6 0.0 9.0 3-0 3-0 7-2 34-2 17-4 6.6 26.4 3-5 14.0 5-2 6.0 trace trace trace trace 0.4 I.O 0.8 28 Imitation whiskey, rye " " malt . . . . " " rye 37-0 42.3 t Includes caramel color. BRANDY AND COGNAC. Brandy is the product of the distillation of fermented grape juice or wine. In a broader sense the term brandy is sometimes applied to liquor distilled from the juices of other fruits, such as apples, peaches, cherries etc. The finest grades of brandy, such as pure cognac and armagnac (named from towns in France in which they were originally distilled), are made from choice white wine by the use of pot stills, and naturally command a high price. Brandy of a lower grade is distilled from the cheaper wines, and sometimes from the fermented marc, or refuse, of the grape, as well as from the lees and "scrapings" of the casks. The best brandies are sometimes rectified by a second distillation. Like whiskey, the fresh brandy is colorless, and would so remain if stored in glass or stone. The color is due to the wooden casks in which it is stored. Brandy consists of nearly pure alcohol and water, having a characteristic flavor, differing somewhat according to the nature and quality of the wine from which it was prepared. The chief flavor of pure cognac is due to cenan- thic ether. Composition. — Vasey gives the following analyses of cognac and of brandy adulterated with neutral spirits: Cognac Brandy Mixed with Neutral Spirits. Ten Years Old. ■' Volatile acids 74. 5 79.4 grams per 100 liters. Esters 109.3 32.4 " " Aldehydes 16.6 7.4 " " Furfural 1.7 0.6 " " Fusel oil 124.2 49.0 " " * Analysis of Potable Spirits, p. 20. 740 FOOD INSPECTION /fND ANALYSIS. Thirty-seven samples of brandy, collected from Massachusetts bar- rooms in 1894 and examined by the State Board of Health, showed the following results: Per Cent Alcohol by- Weight. Per Cent Extract. Maximum ............... 50.70 21.30 40-54 3.00 O.IO 0-93 Minimum. .............. Mean Three of these samples were artificially prepared mixtures of alcohol and water, one showed the presence of cloves, five contained tannin in excess, nine were excessively acid, and two had insoluble residues. Joint Standards. — The following are the standards of the A. O. A. C. and the A. S. N. F. D. D.: New Brandy is a properly distilled spirit made from wine, and contains in 100 liters of proof spirit not less than 100 grams of the volatile flavors, oils, and other substances, derived from the material from which it is made, and of the substances congeneric with ethyl alcohol produced during fermentation and carried over at the ordinary tem- peratures of distillation, the principal part of which consists of the higher alcohols estimated as amylic. Brandy {Potable Brandy) is new brandy stored in wood for not less- than four years without any artificial heat save that which may be- imparted by warming the storehouse to the usual temperature, and contains in 100 liters of proof spirit not less than 150 grams of the sub- stances found in new brandy, save as they are changed or eliminated by storage, and of those produced as secondary bodies during agings and, in addition thereto, the substances extracted from the casks in which it has been stored. It contains, when prepared for consumption, as permitted by the regulations of the Bureau of Internal Revenue, not less than 45% by volume of ethyl alcohol, and, if no statement is made concerning its alcoholic strength, it contains not less than 50% by volume of ethyl alcohol as prescribed by law. Cognac, Cognac Brandy, is brandy produced in the departments of the Charente and Charente Inferieure, France, from wine produced in those departments. U. S. Pharmacopoeia Standards.— According to the U. S. Pharmacopoeia, brandy should be at least four years old; its specific gravity should be ALCOHOLIC BEVERAGES. 741 not more than 0.941 nor less than 0.925; its alcoholic content should be from 39 to 47 per cent by weight; the residue from 100 cc. should not exceed 0.5 gram, and should dissolve readily in 10 cc. of cold water, and this solution should not be colored deeper than a pale green by the addition of dilute ferric chloride solution (absence of more than traces of tannin); the residue should not be sweet nox spicy in taste; a marked disagreeable pungent odor of fusel oil should not manifest itself on the volatilization of the last traces of alcohol in evaporating for the residue; in acidity, not more than i cc. of tenth-normal alkali should be required to neutralize 100 cc. of the brandy, using litmus as an indicator. Adulteration of Brandy. — Much of the brandy sold on the market is a compound or imitation, having for its basis alcohol reduced to the requisite strength, flavored either by the admixture of real brandy, or by various preparations such, for example, as syrup of raisins, prune juice, rum, acetic ether, oenanthic ether, infusion of green walnut-hulls, infusion of bitter almond shells, catechu, balsam of Tolu, etc. Fleischmann gives the following recipe for artificial brandy of the cheapest grade: Spirits 45 gallons Coloring (caramel) 6 ounces Cognac oil -J ounce " Cognac oil " is made up of melted cocoanut oil 16 ounces, sulphuric acid 8 ounces, alcohol 16 ounces, mixed and distilled. While commercial brandy often fails to meet the pharmacopoeial requirements, and may contain any of the above flavoring materials, not one sample has been found among the many examined by the Massa- chusetts Board of Health during upwards of twenty years containing a more injurious ingredient than alcohol. Genuine new brandy may be "aged" or "improved" for immediate use, according to Duplais, by adding to 100 liters the following: Old rum 2.00 liters Old kirsch* 1.75 " Infusion of walnut-hulls 75 liter Syrup of raisins 2 .00 liters The addition of sugar and caramel to brandy is very common. The * Brandy disJIled from cherry wine. 742 FOOD INSPECTION ^ND ANALYSIS. lack of flavor resulting from the employment of "silent spirit," or from watering the product, may be compensated for by the employment of so-called cognac essences sold for the purpose, containing mixtures of the aromatic compounds named above. RUM. Rum is the liquor distilled from fermented molasses or cane juice, or from the scum and other waste juices from the manufacture of raw sugar. The molasses wort is mixed with the residue from a previous fermentation and allowed to ferment for a number of days, after which it is distilled twice and stored in wood for a long time, to remove the dis- agreeable odor, which in the new product is especially marked. The characteristic flavor of old rum is due to a mixture of butyric and acetic ether, principally the former. Pineapples and guavas are often put in the still to impart a fruity flavor. The best varieties of rum come from Jamaica and Vera Cruz. Composition. — The following analysis of rum is by Vasey:* Volatile acids 28.0 grams per 100 liters Esters 399-0 " " Aldehydes 8.4 " Furfural 2.8 " " Fusel oil 90.6 " " Thirty-nine samples of rum, sold at retail in Massachusetts in 1894, were examined by the State Board of Health with the following results: Per Cent Alcohol by Weight. Per Cent Extract. Maximum 42.9 24-7 37-1 3-93 0.04 0.51 Minimum Mean Of these, two samples were new rum, and several were entirely arti- ficial. Joint Standards. — The following are the joint standards of the A. O. A. C. and the A. S. N. F. D. D. : * Analysis of Potable Spirits, p. 85. ALCOHOLIC BEl^ERAGES. 743 New Rum is properly distilled spirit made from the properly fer- mented clean, sound juice of the sugar cane, the clean, sound massacuite made therefrom, clean, sound molasses from the massecuite, or any sound clean intermediate product save sugar, and contains in 100 liters of proof spirit not less than 100 grams of the volatile flavors, oils, and other substances derived from the materials of which it is made, and of the substances congeneric with the ethyl alcohol produced during fermentation, which are carried over at the ordinary temperatures of distillation, the principal part of which is higher alcohols estimated as amylic. Rum {Potable Rum) is new rum stored not less than four years in wood without any artificial heat save that which may be imparted by warming the storehouse to the usual temperature, and contains in 100 liters of- proof spirit not less than 175 grams of the substances found in new rum, save as they are changed or eliminated by storage, and of those produced as secondary bodies, during aging; and, in addition thereto, the substances extracted from the casks. It contains, when prepared for consumption as permitted by the regulations of the Bureau of Inter- nal Revenue, not less than 45% by volume of ethyl alcohol, and if no statement is made concerning its alcoholic strength, it contains not less than 50% by volume of ethyl alcohol as prescribed by law. More or less factitious rum is sold on the market, made up of alcohol diluted to the right strength, colored with caramel, and flavored by the addition of " rum essence." Prune juice is sometimes added. Fleischman gives the following recipe for low-grade artificial rum: Spirits 40 gallons New England rum 5 " Prune juice h gallon Caramel 12 ounces Rum essence 8 " The "rum essence" is made up by distilling 32 ounces of a mixture of 2 ounces black oxide of manganese, 4 ounces pyroligneous acid, 32 ounces alcohol, and 4 ounces sulphuric acid. To this is added 32 ounces of acetic ether, 8 ounces of butyric ether, 16 ounces saffron extract, and ^ ounce oil of birch. 744 FOOD INSPECTION AND ANALYSIS. GIN. Gin is an alcoholic liquor, flavored with the volatile oil of juniper and' sometimes wi'.h other aromatic substances, such as coriander, grains of paradise, anise, cardamom, orange-peel, and fennel. The choicest variety is known as Schiedam schnapps, named from the town of Schiedam in Holland, where there are upwards of 200 distilleries devoted to the manu- facture of gin. The mash used for this variety is fermented by yeast' from malted barley and rye, after which it is distilled and redistilledv in pot stills with juniper berries and sometimes hops. Juniper berries, to which the most characteristic flavor of gin is due, are dark blue in color, and possess a pungent taste. They grow on the slender evergreen shrub Juniperus communis. Gin differs from the other distilled liquors by being water-white. To this end it is kept in> glass and not in wood. Much of the gin of commerce is made by redistilling corn or grain, whiskey with oil of juniper, and frequently one or several of the above- named flavoring materials. Sugar is often added, and sometimes in the cheaper productions oil of turpentine is substituted for juniper oil. Composition. — The following analysis of unsweetened gin is by Vasey : *■ Volatile acids 0.0 grams per 100 liters Esters 37.3 " " Aldehydes 1-8 Furfural 0.0 Fusel oil 44-6 Thirty-three samples of gin, purchased in Massachusetts saloons and analyzed by the State Board of Health in 1894, gave the following; results in per cent of alcohol by weight: Maximum 42.5, minimum 29.5,. mean 38.2. * Analysis of Potable Spirits, p. 85. ALCOHOLIC BEVERAGES. 745 METHODS OF ANALYSIS OF DISTILLED LIQUORS. Specific gravity and alcohol are determined as described on pp. 657- 677. The following methods with the exception of the quahtative test for fusel oil, Mitchell's method, and McGill's opalescence test are those of the A. O. A. C* Determination of Extract. — Weigh or measure (at 15.6° C.) 100 cc. of the sample, evaporate nearly to dryness on the water-batli, then transfer to a water-oven, and dry at the temperature of boiling water for 2h hours. Determination of Acids. — Titrate 100 cc. (or 50 cc. diluted to 100 cc. if the sample is dark in color) with tenth-normal alkali, using phenol- phthalein as indicator, i cc. of tenth-normal alkali is equal to 0.006 of acetic acid. Determination of Esters. — Dilute 200 cc. of the sample with 25 cc. of water and distil slowly into a graduated 200-cc. flask until nearly filled to the mark. Complete the volume, shake, and use aliquot portions for the determination of esters, aldehydes, and furfural. Exactly neutralize 50 cc. of the distillate with tenth-normal alkali, using phenolphthalein as indicator, and add from 25 to 50 cc. of the tenth-normal alkali in excess of that required for neutralization. Either boil for one hour with a reflux condenser, or allow to stand overnight in a stoppered flask, and heat with a tube condenser for one-half hour below the boiling-point. - Cool, and titrate with tenth-normal acid, using phenolphthalein as indicator. Multiply the number of cc. of tenth- normal alkali used in the saponification by 0.0088, thus obtaining the grams of esters calculated as ethyl acetate. Determination of Aldehydes. — i. Reagents. — {a) Alcohol Free from Aldehydes. — Prepare by first redistilling the ordinary 95% alcohol over caustic soda or potash, then add from 2 to 3 grams per liter of w-phenyl- enediamine hydrochloride, digest at ordinary temperature for several days (or reflux on the steam-bath for several hours), and then distil slowly, rejecting the first 100 cc. and the last 200 cc. (6) Sulphite-fuchsin Solution. — Dissolve 0.50 gram of pure fuchsin in 500 cc. of water, then add 5 grams of SO2 dissolved in water, make up to a liter, and allow to stand until colorless. Prepare this solution in small quantities, as it retains its strength for only a very few days. * U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), pp. 95 to loi; Circular 43. 746 FOOD INSPECTION AND ANALYSIS. {c) Standard Acetic Aldehyde Solution. — Prepare according to the directions of Vasey * as follows : Grind aldehyde ammonia in a mortar with ether, and decant the ether. Repeat this operation several times, then dry the purified salt in a current of air and fmally in a vacuum over sulphuric acid. Dissolve 1.386 grams of this purified ammonium aldehyde in 50 cc. of 95% alcohol, to this add 22.7 cc. of normal alco- holic sulphuric acid, then make up to 100 cc. and add 0.8 cc. to com- pensate for the volume of the ammonium sulphate precipitate. Allow this to stand over night and filter. This solution contains i gram of acetic aldehyde in 100 cc. and will retain its strength. The standard found most convenient for use is 2 cc. of this strong aldehyde solution diluted to 100 cc. with 50% alcohol by volume. One cc. of this solution is equal to 0.0002 gram of acetic aldehyde. This solu- tion should be made up fresh every day or so, as it loses its strength. 2. Process. — Determine the aldehyde in the distillate prepared for esters. Dilute from 5 to 10 cc. of the distillate to 50 cc. with aldehyde- free alcohol (50% by volume), add 25 cc. of the fuchsin solution, and allow to stand for fifteen minutes at 15° C. The solutions and the reagents should be at 15° C. before they are mixed. Prepare standards of known strength in the same way. Determination of Furfural. — Standard Furfural Solution. — Dissolve I gram of redistilled furfural in loc cc. of 95% alcohol. This strong solution will keep. Standards are made by diluting i cc. of this solution to 100 cc. with 50% by volume alcohol. One cc. of this solution con- tains 0.000 1 gram furfural. Process. — Dilute from 10 to 20 cc. of the distillate, prepared as described under esters, to 50 cc. with furfural-free alcohol (50% by volume). To this add 2 cc. of colorless anihn and 0.5 cc. of hydro- chloric acid (specific gravity 1.125), and keep for fifteen minutes in a water-bath at about 15° C. Prepare standards of known strength in the same way. Detection of Fusel Oil. — In the process of dealcoholizing a liquor by evaporation in an open dish over the water-bath, one may readily detect fusel oil, if present, by its harsh and nauseating odor, if the nose is applied just at the moment when the last traces of alcohol are going off. At this stage any considerable trace of fusel oil will be especially apparent by the effect on the throat of the one who smells it, causing * Analysis of Potable Spirits, p. 30. ALCOHOLIC BEVERAGES. 747 an uncontrollable desire to cough. Other ways of applying the odor test consist in pouring a small portion of the spirit into the hand, and allowing it to evaporate slowly therefrom, or in rinsing out a warm glass with the liquor, observing the odor in each case. Goebel suggests the following test, based on the detection of the volatile acids: Agitate about 30 cc. of the liquor with 2 or 3 cc. of a dilute solution of potassium hydroxide; evaporate over the water- bath to the volume of 2 or 3 cc, cool, and to the residue add 5 or 6 cc. of concentrated sulphuric acid. If fusel oil be present, the character- istic odors of valerianic and butyric acids will be apparent. Determination of Fusel Oil. — Allen-Mar quardt Method. — Add to 100 cc. of whiskey 20 cc. of half-normal sodium hydroxide, and saponify the mixture by boiling for one hour under a reflux condenser.* Connect the flasks with a distilling apparatus, distil 90 cc, add 25 cc. of water^ and continue the distillation until an additional 25 cc. is collected. Approximately saturate the distillate with finely ground sodium chloride, and add a saturated solution of sodium chloride until the specific gravity is i.io. Extract this salt solution four times with carbon tetrachloride,! using 40, 30, 20, and 10 cc. respectively, and wash the carbon tetrachloride three times with 50-cc. portions of a saturated solution of sodium chloride, and twice with saturated solution of sodium sulphate. Then transfer the carbon tetrachloride to a flask containing 5 cc. of concentrated sulphuric acid, 45 cc of water, and 5 grams of potassium bichromate, and boil for eight hours under a reflux condenser. Add 30 cc of water, and distil until only about 20 cc. remain; add- So cc of water, and distil until but 5 cc. are left. Neutralize the distillate to methyl orange, and titrate with sodium hydroxide, using phenol- phthalein as indicator. One cc. of tenth-normal sodium hydroxide is equivalent to 0.0088 gram of amyl alcohol. Rubber stoppers can be used in the saponification and first distilla- tion, but corks covered with tinfoil must be used in the oxidation and second distillation. Corks and tinfoil must be renewed frequently. * Or 100 cc. of the liquor may be mixed with 20 cc. of half-normal sodium hydroxide, allowed to stand overnight at room temperature, and distilled directly. t Purify 5 liters of carbon tetrachloride by boiling for several hours under a reflux con- denser with 200 cc. of sulphuric acid and 25 grams of potassium bichromate in 200 cc. of water; separate from the oxidizing mixture by distillation, and redistil over barium car- bonate. 748 FOOD INSPECTION AND ANALYSIS. Tolman and Hilly er^s Modification of the Allen-Marquardt Method. — Proceed with the Allen-Marquardt method to the point where the carbon tetrachloride solution of the higher alcohols is ready to be oxidized. Add 50 cc. of a solution of 200 grams of pulverized potassium bichromate in 1800 cc. of water and 200 cc. of concentrated sulphuric acid, very carefully measured with pipette or burette, and start the eight-hour oxidation. Take great care to prevent any isolation of spots of bichromate on the flask during the oxidation. Decomposition of the bichromate from overheating can best be prevented by slow boiling over several thicknesses of asbestos board. After the oxidation is complete, separate the bichromate solution from the carbon tetrachloride in a separatory funnel, care being taken to wash the carbon tetrachloride free from bichromate. Make up the bichromate solution to 500 cc. Place 200 cc. of this solution in a liter flask, add 20 cc. of concentrated hydrochloric acid, 100 cc. of potassium iodide solution (1:1), and 50 cc. of approximately three-fourths normal thiosulphate not standardized. Make this last addition by means of a burette. (If a high content of fusel oil is present, 50 cc. of thiosulphate may be excessive and a smaller amount should be used, the same quantity being added to the sample and to the blank.) Run blanks containing exactly the same amount of reagents with each series, and treat them in the same way, starting them at the point where the carbon tetrachloride is washed with sodium chloride. The titration of this blank, to which has been added exactly the same amount of three-fourths normal thiosulphate, gives the value of the bichromate solution. The difference in cubic centimeters of tenth- normal thiosulphate used in titrating the blank and the samples gives the amount of bichromate reduced by the higher alcohols. This differ- ence in cubic centimeters of tenth-normal thiosulphate multiplied by the factor 0.001773 gives grams of higher alcohols present. Mitchell and Smith Method.^ — This is more rapid than the Allen- Marquardt method and gives more nearly the true amount of fusel oil. Saponify, distil, shake with sodium chloride, and extract with carbon tetrachloride, as in the Allen-Marquardt method. To the carbon tetra- chloride extract, contained in the separatory funnel, add 10 cc. of potassium hydroxide solution (1:1). Cool the mixture in ice- water to approximately 0° C. Similarly cool 100 cc. of a solution of potassium permanganate solution (20 grams to the liter), accurately measured in * A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 199. ALCOHOLIC BEVERAGES. 749 a flask. To the contents of the separatory funnel add the bulk of the permanganate solution, but without rinsing, retaining the residue to be added at a later stage. Remove the mixture from the bath, and shake vigorously for five minutes; set aside for thirty minutes, with occasional shaking, permitting the liquid to warm to room temperature (20 to 25° C.) Accurately measure into a liter Erlenmeyer flask 100 cc. of a solution of hydrogen peroxide slightly (about 2%) stronger than the perman- ganate solution, acidulate with 100 cc. of an approximately 25% sul- phuric acid solution, and slowly add the contents of the separatory funnel with constant shaking, keeping the acid solution constantly in excess. Rinse the separatory funnel and the flask containing the residue of permanganate with water and add to the peroxide solution. Finally titrate the excess of hydrogen peroxide with standard potassium per- manganate solution (10 grams to the liter). Run a blank determination, using the same amounts of the stronger permanganate, potassium hydroxide, hydrogen peroxide, and sulphuric acid solutions, and titrating the residual peroxide with the standard potassium permanganate as before. The difference in the amounts of permanganate consumed, in grams, times 0.696, gives the amount of amyl alcohol. Detection of Methyl Alcohol. — Leach and Lythgoe Immersion Refrac- tometer Method.'^ — Determine at 20° C. the refraction of the distillate obtained in the determination of alcohol by the immersion refractometer. If on reference to the table the refraction shows the percentage of alcohol agreeing with that obtained from the specific gravity, it may be safely assumed that no methyl alcohol is present. If, however, there is an appreciable amount of methyl alcohol, the low refractometer reading will at once indicate the fact. If the absence from the solution of other refractive substances than water and the alcohols is assured, this quali- tative test by difference in refraction is conclusive. The addition of methyl to ethyl alcohol decreases the refraction in direct proportion to the amount present; hence the quantitative calcu- lation is readily made by interpolation in the table, using the figures for pure ethyl and methyl alcohol of the same alcoholic strength as the sample. Example. — Suppose the distillate made up to the original volum.e of the measured portion taken for the alcohol determination has a * Jour. Am. Chem. Soc, 27, 1905, p. 964. 750 FOOD INSPECTION AND ANALYSIS. specific gravity of 0.9736, corresponding to 18.38% alcohol by weight,, and has a refraction of 35.8 at 20° C. by the immersion refractometer; by interpolation in the refractometer table the readings of ethyl and methyl alcohol corresponding to 18.38% alcohol are 47.2 and 25.4, respectively, the difference being 21.8; 47.2—35.8=11.4; (11.4-^21.8) 100=52.3, showing that 52.3 of the alcohol present is methyl alcohol. SCALE READINGS ON ZEISS IMMERSION REFRACTOMETER AT 20° C, CORRESPONDING TO EACH PER CENT BY WEIGHT OF METHYL AND ETHYL ALCOHOLS. Scale Scale Scale Scale Readings. Readings. Readings. Readings. Per Cent Per Cent Alcohol Per Cent Alcohol Per Cent Alcohol Alcohol by Weight. Methyl Al- Ethyl Al- by Weight. Methyl Al- Ethyl Al- by Weight. Methyl Al- Ethyl Al- by Weight. Methyl Al- Ethyl Al- cohol. cohol. cohol. cohol. cohol. cohol. cohol cohol. 14.5 14-5 26 30.3 61.9 51 39-7 91. 1 76 29.0 lOI.O I 14.8 16.0 27 30-9 63-7 52 39-6 91.8 77 28.3 100.9 2 15-4 17.6 28 31.6 65-5 53 39-6 92.4 78 27.6 100.9 3 16.0 19.1 29 32-2 67.2 54 39-5 93 -o 79 26.8 100.8 4 16.6 20.7 30 32.8 69.0 55 39-4 93-6 80 26.0 100.7 5 17.2 22.3 31 33-5 70.4 56 39-2 94-1 81 25-1 100.6 6 17-8 24.1 32 34-1 71-7 57 39-0 94.7 82 24-3 100. 5 7 18.4 25-9 2,Z 34-7 73-1 58 38.6 95-2 83 23.6 100.4 8 19.0 27.8 34 35-2 74-4 59 38.3 95-7 84 22.8 100.3 9 19.6 29.6 35 35-8 75-8 60 37-9 96.2 85 21.8 100. 1 10 20.2 31-4 36 36-3 76.9 61 37-5 96.7 86 20.8 99-8 II 20.8 33-2 37 36.8 78.0 62 37-0 97-1 87 19.7 99-5 12 21.4 35-0 38 37-3 79-1 63 36.5 97-5 88 18.6 99-2 13 22.0 36.9 39 37-7 80.2 64 36.0 98.0 89 17-3 98.9 14 22.6 38-7 40 38.1 81.3 65 35-5 98-3 90 16. I 98.6 15 23.2 40.5 41 38.4 82.3 66 35-0 98.7 91 14.9 98-3 16 23-9 42.5 42 38.8 83-3 67 34-5 99.1 92 13-7 97.8 17 24-5 44-5 43 39-2 84.2 68 34-0 99-4 93 12.4 97.2 18 25.2 46.5 44 39-3 85.2 69 33-5 99-7 94 11. 96.4 19 25.8 48.5 45 39-4 86.2 70 3i-° 100. 95 9.6 95.7 20 26.5 50.5 46 39-5 87.0 71 32-3 100.2 96 8.2 94.9 21 27.1 52.4 47 39-6 87.8 72 31-7 100.4 97 6.7 94.0 22 27.8 54-3 48 39-7 88. 7 73 31-1 100.6 98 5-1 93.0 23 28.4 56.3 49 39-8 89-5 74 30-4 100.8 99 3-5 92.0 24 29.1 58.2 50 39-8 90-3 75 29.7 lOI.O 100 2.0 91.0 25 29.7 60.1 Trillat Method.* — To 50 cc. add 50 cc. of water and 8 grams of lime, and fractionally distil by the aid of Glinksy bulb tubes. Dilute the *A. Trillat, 'Aftalyst," 24, 1899, pp. 13, 211-212. ALCOHOLIC BEVERAGES. 751 first 15 cc. of the distillate to 150 cc, mix with 15 grams of potassium bichromate and 70 cc. of sulphuric acid (1:5), and allow to stand for one hour with occasional shaking. Distil, reject the first 25 cc, and collect 100 cc. Mix 50 cc. of the distillate with i cc of rectified dimethyl-anilin, transfer to a stout, tightly-stoppered flask, and keep on bath at 70 to 80° C. for three hours with occasional shaking. Make distinctly alkahne with sodium hydrox- ide, and distil the excess of dimethyl-anilin, stopping the distillation when 25 cc. have passed over. Acidify the residue in the flask with acetic acid, shake, and test a few cc. by adding four or five drops of water with lead dioxide in suspension (i gram in 100 cc). If methyl alcohol be present, a blue coloration occurs which is increased by boiling. Note.- — -Ethyl alcohol thus treated yields a blue Qoloration, changing immediately to green, afterwards to yellow, and becoming colorless when boiled. Riche and Bardy Method.'^ — The following method for the detection of methyl alcohol in commercial spirit of wine depends on the formation of methyl-anilin violet: Place 10 cc. of the sample, previously rectified over potassium car- bonate if necessary, in a small flask with 15 grams of iodine and 2 grams of red phosphorus. Keep in ice-water for from ten to fifteen minutes until action has ceased. Distil on a water-bath the methyl and ethyl iodides formed into about 30 cc. of water. Wash with dilute alkali to eliminate free iodine. Separate the heavy oily liquid which settles, and transfer to a flask containing 5 cc. of anilin. The flask should be placed in cold water, in case the action should be violent, or, if necessary, the reaction may be stimulated by gently warming the flask. After one hour boil the product with water, and add about 20 cc. of a 15% solution of soda; when the bases rise to the top as an oily layer, fill the flask up to the neck with water, and draw them off with a pipette. Oxidize i cc. of the oily liquid by adding 10 grams of a mixture of 100 parts of clean sand, 2 of common salt, and 3 of cupric nitrate; mix thoroughly, intro- duce into a glass tube, and heat to 90° C. for eight or ten hours. Exhaust the product with warm alcohol, filter, and make up with alcohol to 100 cc If the sample of spirits be pure, the liquid is of a red tint, but in the -presence.of i% of methyl alcohol, it has a distinct violet shade; with * Allen's Commercial Organic Analysis, 3d ed., I, p. 80. 752 FOOD INSPECTION AND ANALYSIS. 2.5% the shade is very distinct, and still more so with 5%. To detect more minute quantities of methyl alcohol, dilute 5 cc. of the colored liquid to 100 cc. with water, and dilute 5 cc. of this again to 400 cc. Heat the hquid thus obtained in porcelain, and immerse a fragment of white merino (free from sulphur) in it for half an hour. If the alcohol be pure, the wool will remain white, but if methylated, the fiber will become violet, the depth of tint giving a fair approximate in- dication of the proportion of methyl alcohol present. Detection of Caramel. — Crampton and Simon'' s Method* — Evaporate 50 cc. of the liquor nearly but not quite to dryness in an evaporating-dish on the water-bath. Wash with water into a 50-cc. graduated glass-stoppered flask, add 25 cc. of absolute alcohol, and fill to the mark with water. Shake, and transfer 25 cc. of the solution to a separatory funnel of the type presented in Fig. 116, the stem of which terminates in a 25-cc. graduated bulb pipette, provided with a stop-cock as shown. Add 50 cc. of ether, and shake carefully at intervals during half an hour. After complete separation, make up the lower aqueous layer with water to the 25-cc. mark, which may be done by siphoning it in through a rubber tube from an elevated flask, controlling the supply by the stop-cock. Shake the separatory funnel, and again allow the layers to separate, draw off the Fig. 116. — Separa- aqueous layer, and compare with the color of the orig- tory Funnel for ^^^^ liquor. Express the amount of color removed as Detecton of r 1 1 t- 1 -n i-i i- Caramel P^^ "^^^'^ ^^ ^'^^ ^°^^^ amount. Ether will readily dis- solve the natural color due to oakwood (mainly flave- scin), while caramel is insoluble in ether; hence uncolored liquors are partially decolorized by this treatment, while those colored with caramel show little change. Amihor Test, Modified by Lasche.'\ — Add 10 cc. of paraldehyde to 5 cc. of the sample contained in a test tube and shake. Add absolute alcohol, a few drops at a time, shaking after each addition until the mixture becomes clear. Allow to stand. Turbidity after ten minutes is an indication of caramel. * Jour. Am. Chem. Soc, 22 1900, p. 810. t The Brewer Distiller, May, 1903. y^LCOHOLIC BEyER^GES. 753 Determination of Water-insoluble Color in Whiskies. — Evaporate 5c cc. of the sample just to dryness. Take up with cold water, using approximately 15 cc, filter, and wash until the filtrate amounts to nearly 25 cc. To this filtrate add 25 cc. of absolute alcohol or 26.3 cc. of 95% by volume alcohol, and make up to 50 cc. by the addition of water. Mix thoroughly and compare in a colorimeter with the original material. Calculate the per cent of color insoluble in water from these readings. Determination of Color Insoluble in Amyl Alcohol. — Modified Marsh Test. — Evaporate 50 cc. of the whiskey just to dryness on the steam- bath. Add 26.3 cc. of 95% alcohol to dissolve the residue. Transfer to a 50-cc. flask and make up to volume with water to obtain a uniform alcohol concentration. Place 25 cc. of this solution in a separatorv funnel, and add 20 cc. of the Marsh reagent, shaking lightly so as not to form an emulsion. (This reagent consists of 100 cc. of pure amyl alcohol, 3 cc. of syrupy phosphoric acid, and 3 cc. of water; shake before using.) Allow the layers to separate, and repeat this shaking and standing twice again. After the layers have clearly separated, draw off the lower or watery layer which contains the caramel into a 25-cc. cylinder, and make up to volume with 50% by volume alcohol. Com- pare this solution in a colorimeter with the untreated 25 cc. Calculate the result of this reading to the per cent of color insoluble in amyl alcohol. Opalescence in Diluted Alcohol Distillate. — McGill * has shown that in the case of liquors made from thoroughly rectified grain spirit, there is little or no opalescence produced when the alcoholic distillate (i.e., that used in determining the alcohol) is diluted with an equal volume of water, while in the case of liquors distilled from alcoholic infusions without rectification, the opalescence is marked. He ascribes the opales- cence to the presence of minute amounts of volatile oils present in wine maic, grains, and other sources of these liquors, soluble in strong, but insoluble in dilute alcohol. Whether due to this or to the separation of minute traces of fusel oil on dilution, the presence or absence of tur- bidity certainly furnishes a rough distinguishing test, indicating in some cases the exclusive use of rectified spirit. * Bui. 27, Canadian Inland Rev. Dept. 754 FOOD INSPECTION AND ANALYSIS. LIQUEURS AND CORDIALS. These are manufactured beverages, usually high in alcohol and sugar, flavored with a wide variety of aromatic herbs or essences, and often strongly colored. Red colors most frequently used for this purpose are cochineal, cudbear, and red sandal and Brazil woods; for yellow colors, caramel and saffron-yellow are employed; for blue, indigo; and for green, chlorophyll and malachite green. Some of the oldest of the liqueurs, such as chartreuse and benedictine, derive their names from certain monasteries of Europe, in which they have been made for many years. Absinthe is one of the best-known cordials, made by redistilling 40% alcohol in which wormwood, anise, sweet flag, and marjoram leaves have been macerated. Sometimes coriander and fennel are also used. It is highly intoxicating. Curagao is made by distilling dilute spirits in which Curasao orange- peel,* cinnamon and often other spices have been soaked, and by adding sugar to the resulting liqueur. De Brevans gives the following recipe for curajoa: Rasped skins of 18 or 20 oranges Cinnamon 4 grams Mace 2 " Alcohol (85%) 5 liters White sugar 1750 grams Macerate for fourteen days, distill without rectification, and color with caramel. Angostura owes its flavor to x\ngostura bark and various spices. Maraschino had originally for its basis the fermented juice of the sour Italian cherry, to which honey was added. It is more commonly made by distilling a mixture in alcohol of ripe wild cherries, raspberries, cherry leaves, peach nuts, and orris. Finally sugar is added. Chartreuse and Benedictine contain much sugar, and are flavored with the volatile oils of angelica, hyssop, nutmeg, and peppermint. Noyau, or Creme de Noyau, is a preparation distilled from brandy, bitter almonds, mace and nutmeg. Sugar and coloring matter, usually pink, are added to the final product. * This is a very rare and highly prized orange, growing in the island of Curasao. ALCOHOLIC BE J^E RAGES. 755 Crime de Menthe, according to De Brevans, is made by distilling a jnLxture of Peppermint 600 grams Balm 40 " Sage 10 " Cinnamon 20 " Orris root 10 " Ginger 15 " Alcohol (80%) 5030 cc. producing finally 10 liters of the liquor, after 3750 grams of white sugar have been introduced. The better grades of creme de menthe were formerly colored with an alcoholic solution of chlorophyll, derived by macerating bruised green leaves of various plants with alcohol, but at present, coal-tar dyes are used. Frequently the desired shade is secured by mixing a green (e.g., Light Green S.F.), a blue-green (e.g., Malachite Green), or a blue (e.g., Indigo Carmine) with a yellow color. The following analyses, due to Konig, show the chemical composition of the best-known cordials: Specific Gravity. Alcohol by Vol- ume. Alcohol by Weight. Extract. Cane Sugar. Other Extrac- tives. Ash. Absinth? Benedictine Ginger Creme de menthe. . . . Anisette de Bordeaux Cura,"oa Kiimmel Angostura Chartreuse 0.91 16 1.0709 I. 0481 1.0447 1.0847 I . 0300 1.0830 0.9540 1.0799 58-93 52 47-5 48.0 42.0 55-0 33-9 49-7 43-18 38.5 36.0 36-5 30-7 42-5 24.8 0.18 36.00 27.79 28.28 34-82 28.60 32.02 5-85 36.11 0.32 3-43 1.87 0.65 0.38 o. 10 0.84 1 .69 1 .76 0.043 0.141 0.068 0.040 0.040 0.058 Analysis of Cordials and Liqueurs. — The character of the essences and flavoring principles used in these beverages is so widely varied that jio regular systematic plan for identifying them can be made applicable to all cases. The senses of smell and taste are most useful, both when applied directly to the liqueur itself and to the dry extract, for suggestions as to the main ingredients employed. Coloring-matters, sugars, acids, and alcohol are determined as with other liquors, except that in the case •of alcohol all volatile oils must first be separated out by treatment with magnesia, as directed for alcohol in lemon extract. Presence of volatile 756 FOOD INSPECTION /IND ANALYSIS. oils is shown, if on treatment of a few cubic centimeters of the sample in a test-tube with water a precipitate is formed. GENERAL REFERENCES ON ALCOHOLIC BEVERAGES. (See also References on Leavening Materials, page 364.) Bersch, J. Gahrungs-Chemie fiir Praktiker. Berlin. Vol. I, Die Hefe und die Gahr- ungs Erscheinungen, 1879. Vol. II, Fabrikation von Malz, Malz Extract und Dextrin, 1880. Vol. Ill, Die Bierbrauerei, 1881. BiGELOW, W. D. Fermented and Distilled Liquors. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 81. 1902. BouRGUELOT, E. Des Fermentations. Paris, 1889. Brevans, J. DE. The Manufacture of Liquors and Preserves. New York, 1893. Crampton, C. a. Fermented Alcoholic Beverages. U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 3. 1887. DuPLAis, P. (Translated by McKennie, M.) A Treatise on the Manufacture and Distillation of Alcoholic Liquors. Philadelphia. Fleischman, J. The Art of Blending and Compounding Liquors and Wines. New York, 1885. GiRARD, C. La Fabrication des Liqueurs et des Conserves. Paris, 1890. Hansen, E. Ch. Untersuchungen aus der Praxis der Gahrungs-Industrie. Munchen^ 1889. Leach, A. E., and Lythgoe, H. C. The Detection and Determination of Ethyl and Methyl Alcohols in Mixtures by the Immersion Refractometer. Jour. Am. Chem. Soc, 27, 1905, p. 964. Mew, J., and Ashton, J. Drinks of the World. London, 1892. Pasteur, M. Studies in Fermentation. London, 1879. Prescott, a. B. Critical Examination of Alcoholic Liquors. New York, 1880. Spencer, E. The Flowing Bowl. A Treatise on Drinks of all Kinds and of all Periods. London, 1899. • Stevenson, T. A Treatise on Alcohol with Tables of Spirit Gravities. London, 1888. A Treatise on the Manufacture, Imitation, Adulteration and Reduction of Foreign Wines, Brandies, Rums and Gins, based upon the " French System," by a Practical Chemist and Experienced Liquor Dealer. REFERENCES ON BEER. Allen, A. H., and Chattaway, W. Detection of Hop Substitutes in Beer. Analyst,. 12, 1887, p. 107; also Analyst 15, 1890, p. 181. Barnard, H. E. Report on Beer. U. S. Dept. of Agric, Bur. of Chem., Bui. 90, p. 64. Brevans, J. de. Analyse des Matieres Alimentaires (Girard et Dupre), p. 183. Paris,^ 1894. Elion, H. Detection of Antiseptics in Beer. Analyst, 16, 1891, p. 116. Faulkner, F. Theory and Practice of Modern Brewing. London, 1888. Hefelmann, R., and Mann, P. Detection of Fluorine in Beer. Pharm. Centralh.^ 16, 1895, p. 249; Abs. Analyst, 20, 1895, p. 185. y4LCOHOUC BEyERAGES. 757 Kelynack, T. N., and Kirby, W. Arsenical Poisoning in Beer Drinkers. London, 1901. LiNDET, L. LaBierre. Paris, 1892. Lindner, C. Lehrbuch der Bierbrauerei. Braunschweig, 1878. Macfarlane, T. Malt Liquors. Canada Inl. Rev. Dept., Bui., 52. Parsons, C. L. The Identification and Composition of Malt Liquors. Jour. Am. Chem. Soc, 24, 1902, p. 11 70. Pasteur, M. Etudes sur la Bierre. Paris, 1876. PiESSE, C. H. Chemistry in the Brewing Room. London, 1891. Prior, E. Chemie und Physiologie des Maizes und des Bieres. Leipzig, 1896. Stierlein, R. Das Bier und seine Verfalschungen. Berlin, 1878. REFERENCES ON CIDER AND WINE. Alwood, W. B. a Study of Cider Making. U. S. Dept. of Agric, Bur. of Chem., Bui. 71. Alwood,. W. B., Davidson, R. J., and Moncure, W. A. P. The Chemical Com- position of Apples and Cider. U. S. Dept. of Agric, Bur. Chem., Bui. 88. Arauner, P. Der Wein und seine Chemie. Kitzingen, a. M., igo6. Barillot, E. Manuel de I'Analyse des Vins. Paris, 1889. Barth, M. Die Weinanalyse. Leipzig, 1884. Bastide, E. Les Vins Sophistiques. Paris, 1889. Browne, C. A. The Chemical Analysis of the Apple, and some of Its Products. Jour. Am. Chem. Soc, 23, 1901, p. 869. The Effects of Ferme^ntation upon the Composition of Cider and Vinegar. Jour. Am. Chem. Soc, 25, 1903, p. 16. BoRGMANN, E. Anleitung zur chemischen Analyse des Weines. Wiesbaden, 1898. Cazeneuve, p. La Coloration des Vins par les Couleurs de la Houille. Paris, 1886. Chace, E. M. Qualitative Detection of Saccharine in Wine. Jour. Am. Chem. Soc, 26, 1904, p. 1627. Embrey, G. a Comparison of English and American Cider^ A.'ith Suggestions for Estimating the Amount of Added Water. Analyst, 16, 1891, p. 41. Gautier, a. La Sophistication des Vins. Paris, 1S84. Macfarlane, T. Wines. Canada Inl. Rev. Dept., Bui. 38. Nessler, J. Die Bereitung, Pflege und Untersuchung des Weins. Stuttgart, 1889. Niviere, G., and Hubert, A. Detection of Fluorine in Wine. Monit. Scient., 9, 1895, p. 324; Abs. Analyst, 20, 1895, p. 185. Pasteur, M. Etudes sur le Vin. Paris, 1873. Robinet, E. Manuel Pratique d'Analyse des Vins. Paris, 1888. Ross, S. H. Determination of Glycerine in W^ine. A. O. A. C. Proc 1909. U. S. Dept. of Agric, Bur. of Chem., Bui. 132, p. 85. Sangle-Ferriere. Analyse des Matieres Alimentaires (Girard et Dupre), Paris, 1894. Vin., p. 65. Cidre, p. 217. Smith, A. W., and Parks, N. Composition of Ohio Wines. Jour. Am. Chem. Soc,, 20, 1908, p. 878. WiNDiscH, K. Die chemische Untersuchung und Beurtheilung des Weines. Berlin,, 1896. 758 FOOD INSPECTION AND ANALYSIS. REFERENCES ON DISTILLED LIQUORS. Adams, A. B. The Detection of Substitution of Spirits for Aged Whiskey. Jour. Ind. Eng. Chem., 3, 1911, p. 647. Allen, A. H. The Chemistry of Whiskey and Allied Products. Jour. Soc. Chem. Ind., 10, 1891, p. 312. Brannt, W. T. Practical Treatise on the Distillation of Alcohol. Phila., 1885. CR-A.MPTON, C. A. Detection of Foreign Coloring Matter in Spirits. Jour. Am. Chem. Soc, 22, 1900, p. 810. Crampton, C. a., and Tolman, L. M. A Study of the Changes Taking Place in Whiskey Stored in Wood. Jour. Am. Chem. Soc, 30, 1908, p. 98. Gabf.r, a. Die Fabrikation von Rum, Arrak, Cognac, etc. Leipzig, 1886. Macfarlane, T., and McGill, A. Distilled Liquors. Canada Inl. Rev Dept., Bui. 27. Mitchell, A. S., and Smith, C. R. The Determination of Fusel Oil by Alakaline Permanganate. A. O. A. C. Proc 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 199. MouzERT. The Practical Distiller. 1890. Ladd, E. F. Whiskey. N. Dak. Agric. Exp. Sta. Bulletins 57, 63 and 69. Reports 1906 and 1907. RiCHTER, H. Analyse des Rums. Zeits. landw. Gervi^erbe, 9, 1889, p. 11. Sanglier, a. Alcohols et Spiritueux. Analyse des Matieres Alimentaires (Girard et Dupre), p. 253. Paris, 1894. Scala, a. Rum and Its Adulteration. Gazetta Chem. Ital., 1891, 396; Abs. Ana- lyst, 17, 1892, p. 79. Sell, E. Ueber Cognac, Rum, Arrak, etc. Berlin, 1890. Shepard, J. H. The Constants of Whiskey. Report of the Chemist of the South Dakota Food and Dairy Commission, March, 1906. Stallings, R. E. An Examination of Whiskeys. N. Dak. Agric. Exp. Sta. Rep. 1906, p. 138. ToLMAN, L. M., and Hillyer, W. E. Methods of Analysis of Distilled Spirits. A. O. A. C. Proc. 1908. U. S. Dept. Agric. Bur. of Chem., Bui. 122, p. 206. Tolman, L. M., and Trescot, T. C. A Study of the Methods for the Determination of Esters, Aldehydes and Furfural in Whiskey. Jour. Am. Chem. Soc, 28, 1906, p. 1619. Vasey, S. a. Guide to the Analysis of Potable Spirits. London, 1904. U. S. Dept. of Agric, Food Inspection Decisions, 45, 65, 95, 98, 113, and 127. CHAPTER XVI. VINEGAR. Vinegar is the product formed by the acetic fermentation of an aico holic liquid under the influence of the organism mycoderma aceti, existing in the " mother-of- vinegar. " Wliile vinegar may be made directly from a dilute solution of pure alcohol, it is more often obtained from fruit juice, wine, or other saccharine liquid that has first undergone alcoholic fer- mentation. Of the following equations, (i) and (2) illustrate the processes ot inversion and alcoholic fermentation respectively, while (3) and (4) show the double process of acetic fermentation, wherein the alcohol is oxidized, first to acetaldehyde and finally to acetic acid: Ci2H3,Oi,+ H30-2C«H,A; (i) Cane sugar Invert sugar C„Hi206 = 2C2H«0-f-2C02; (2) Invert sugar. Alcohol dextrose, or maltose QH«0 + = C2H,0 + H20; (3) Alcohol Aldehyde C,H,0+0 = C,HA. . , o . . . . (4) Aldehyde Acetic acid In addition to the acetic acid, its chief active principle, vinegar usually contains traces of other organic acids free or combined, small amounts of alcohol, aldehyde, sugar, glycerin, coloring matter, aromatic ethers, and mineral salts, its extract varying considerably with the source from which the vinegar was obtained. Varieties. — The principal varieties of vinegar are the following : Cider vinegar, wine vinegar, malt or beer vinegar, spirit vinegar, glucose vinegar, molasses vinegar, and wood vinegar, the three last being more frequently used as adulterants of the others. 759 76 D FOOD INSPECTION AND /IN A LYSIS. Manufacture of Vinegar. — Cider vinegar, the principal variety used in- the United States and Canada, was formerly made almost entirely by the slow process of cask fermentation, the fresh cider being allowed to undergo both alcoholic and acetic fermentation in barrels with open bung-holes in a warm cellar, or exposed to the sun. Two or three years are required for this process. Sometimes fresh cider is added to the barrels at regular intervals of two or three weeks, thus causing a series of progressive fer- mentations. The acetic fermentation is hastened by adding old vinegar, or mother-of- vinegar to the cider. While farmers and some manufac- turers still continue to make cider vinegar by the slow process, the quick or "generator" vinegar process is now much used for cider vinegar, though originally intended and almost exclusively used in the manufacture of malt, beer, and spirit vinegar. This process requires only two or three days for complete acetification. In the quick process, the cider or other alcoholic liquor is allowed to percolate slowly through beech- wood shavings or birch twigs, held in a cask known as a generator, provided with a perforated, false bottom, the shavings or twigs being previously saturated with old vinegar, and a current of air being passed up through them. The alcoholic liquid from which genuine malt vinegar is made is derived from the wort obtained by mashing malt, or a mixture of malt and barley. Spirit vinegar is derived from diluted whiskey, brandy, or grain alcohol. Wine vinegar is made by allowing the wine to stand over wine lees for a time, after which it is clarified by passing through beech shavings, and subjected to progressive acetification in large open oak casks, to which the wine is added, the vinegar being drawn off in much the same manner as the slow-process cider vinegar. Characteristics and Composition of the Various Vinegars. — Cider Vinegar is brownish yellow in color, and possesses an odor of apples. It is chiefly distinguished from other vinegar by the large amor.nt of malic acid normally present, by the character of its sugars, and by the predominance of potash in the ash. Its specific gravity varies from 1.013 to 1. 01 5. Its acidity varies from 3 to 6 per cent, and its solids from i^ to 3 per cent. Cider vinegar under polarized light is always laevo-rotary. The following are summarized data of analyses made by H. C. Lyth- goe in the writer's laboratory of twenty-two samples of cider vinegar o£ known purity: yiNEGAR. 761 Maximum Minimum. Average. . Acetic Acid. 5-86 3-92 4.84 Total Solids. 3.20 1.84 2.49 Ash. 0.42 0.20 0-34 Alkalin- ity of Ash.' 36.1 22.2 29.7 P205in Ash of 100 Grams Vinegar. Soluble (mgr.). 31-7 12. I 19.2 Insoluble I (mgr.). ! 31-5 I 6.5 I 15-6 Reducing Sugars. Polariza- tion, Degrees Ventzke 200-mm. Tube. Malic Acid. Per Cent Ash in Total Solids. Before Inversion. After Inversion. 0-51 0-15 0.25 0-53 0.15 0.25 -3-6 -0-3 -1-3 0.16 - 0.08 O.II 19.0 10. 13.8 Percent R^tio of Reducmg Soluble Sugars in Total Solids. to Total P2O5. Alkalin- ity of I Gram of Ash, cc. — Acid. Maximum. Minimum. Average 16.6 7-3 10.7 66.9 ^0.0 56.3 125.0 69.0 90.0 1 Number of cubic centimeters of tenth-normal acid to neutralize the ash of loo grams of vinegar. Twenty-two samples of pure cider vinegar were analyzed by A. W. Smith * with the following results : Acetic Acid. Total SoHds. Ash. Alkalinity of Ash.' Solub.'e P2OS. Insoluble P2O5. Total P2O5. Maximum 7.6r 3-24 4.46 4-45 2.00 2-83 0.51 0.31 0-39 55-2 28.4 38.8 22-7 13-6 19. 1 19.4 4-2 10. 1 39-0 19.8 28 6 Minimum Average ' Number of cubic centimeters of tenth-normal acid required to neutralize the ash from 100 grams of vinegar. The composition of cider vinegar ash is found by Doolittle and Hess f to be as follows: Calcium oxide CaO. 3.4 to 8.21 Magnesium oxide MgO 1.88 " 3.44 Potassium oxide KjO 46.33 " 65.64 Sodium oxide NazO None Sulphuric anhydride. . . . SO3 4.66 to 16.29 Phosphoric anhydride . . P2O5 3-29" 6.66 Iron oxide FejO, None '* trace CO, and loss 0.00 " 40.44 Wine Vinegar is light yellow if made from white wine, and red if from red wine. The former is the highest prized. Wine vinegar varies in specific * Jour. Am. Chem. Soc, 20 (1898), p. 6. t Ibid., 22 (1900), p. 220. 762 FOOD INSPECTION AND ANALYSIS. gravity from 1.0129 to 1.0213, and contains from 6 to 9 per cent of acetic acid. It is characterized chiefly by the bitartrate of potassium (cream of tartar) which true wine vinegar always possesses. Free tartaric acid is also usually present. Wine vinegar is the principal vinegar of France and Germany. In the United States the term while wine vinegar is usually applied to distilled or spirit vinegar, which is much cheaper than the real wine vinegar and altogether inferior to it. Wine vinegar is slightly laevo-rotary with polarized light. The composition of genuine white wine vinegar is shown by the follow- ing summary of the analyses of twenty-two samples, made in the Municipal Laboratory of Paris: Specific Gravity. Total Solids. Sugar. Bitartrate of Potash. Ash. Acidity (as Acetic). 3-19 1.38 1-93 0.46 0.06 0.22 0.36 0.07 0.17 o.6q 0.16 0.32 7.38 4-44 7-38 Weigmann gives the following average of analyses of red wine vinegar: Specific Gravity. Acetic Acid. Total Tartaric Acid. Free Tartaric Acid. Cream of Tartar. Alcohol, j Extract. [ ^^^^ Ash. Phos- phoric Acid. I-OI43 7-79 0.216 0.006 0.057 1. 19 ! 0.863 1 0.141 0.118 0.012 Malt or Beer Vinegar is of a brown color, and its odor is suggestive of sour beer. It varies in specific gravity from 1.015 to 1.025; its acidity is about the same as cider vinegar, but the extract is much larger, varying from 4 to 6 per cent. Malt vinegar contains considerable nitrogenous matter, and notable quantities of phosphates, dextrin, and mahose. It contains no cream of tartar. Malt vinegar is largely used in Great Britian. Hehner gives the following data of the analyses of seven samples of vinegar undoubtedly made from malt only.* Maximum Minimum. Mean . Acidity. 6.48 2.88 4-23 Total Solids. 4-23 1.68 2 .70 Ash. 0.47 0.22 0-34 Phosphoric Anhydride. ■13 .067 .105 Alkalinity ( NasCOs). Analyst, 16, p. 82. See also Analyst, :8, p. 240. .089 .017 .024 VINEGAR. 763 Allen gives the results of the analyses of three samples of genuine vinegar brewed from a mixture of malted and unmalted barley as follows : * Specific Gravity. Acetic Acid. Total Solids. Ash. Alkalinity as KsO.' Phos- phoric Acid. Nitrogen. Albumin- oids. I I. 0170 1.0228 I. 0160 6-39 5.26 4.86 2.67 3-96 2.31 0.34 0.40 0.47 0.091 0.118 0.077 0.093 0.057 .099 .095 .099 .624 .598 .624 2 ■2 Distilled, Spirit, or Alcohol Vinegar. — This vinegar, being made from diluted alcohol, is nearly colorless, unless artificially colored, as it often is, with caramel. As stated on page 762, the "white wine" vinegar (incor- rectly so-called) commonly sold in the United States is of this class. Its specific gravity ranges from 1.008 to 1.013. Spirit vinegar contains from 3 to-io per cent of acetic acid. Its content of total solids is insig- nificant, and it contains only traces of ash. It always contains non- acetified alcohol and aldehyde. It has no optical activity with polarized light. Twelve samples of alcohol vinegar analyzed in the Municipal Labora- tory of Paris gave the following results: Specific Gravity. Total Solids. Sugar. Ash. Acidity. Maximum I.0131 1.0082 I.OIOO 0.16 0.07 0-35 Trace << .09 .04 Trace 7.98 4.98 6-34 Minimum. Mean Glucose Vinegar is made from the acetification of alcohol, obtained from the fermentation of commercial glucose. This vinegar usually possesses the odor and taste of fermented starch. It is low in total solids, , the extract consisting almost entirely of untransformed glucose, and the vinegar therefrom contains all the ingredients of the product from which it was made, viz., dextrin, maltose, and dextrose, as well as chloride of sodium. It is decidedly dextro-rotatory with polarized light boch before and after inversion. Molasses Vinegar. — This is largely the product of the acetic fermen- tation of sugar-house wastes, and sometimes of the accidental acetic fermentation of molasses itself, after it has undergone alcoholic fermenta- tion for the manufacture of rum. This variety of vinegar is sometimes- * Analyst, 19, p. 15. 764 FOOD INSPECTION AND ANALYSIS. used as an adulterant of cider vinegar. With polarized light molasses vinegar is dextro-rotary before, and laevo-rotary after inversion. Wood Vinegar is prepared by the purification of pyroligneous acid, which may be accomplished by saturating the crude acid with lime or soda, adding hydrochloric or sulphuric acid, and distilling. It is further purified by redistillation with potassium bichromate, and filtration through bone- black. Acetic acid is sometimes added to impart flavor. The extract and ash of wood vinegar are very small. Its specific gravity averages 1.007 according to Blyth. Empyreumatic or tarry products are nearly always present in vinegar of this class. ANALYSIS OF VINEGAR. Specific Gravity. — This is obtained either with the hydrometer, pyc- nometer, or Westphal balance. Determination of Total Solids. — Weigh 10 grams of the sample in a tared platinum dish 50 mm. in diameter, evaporate to dryness on a boiling- water bath and dry for two and one-half hours in a water oven at the tem- perature of boiling water. Cool in a desiccator and weigh. Determination of Ash.— Transfer the dish containing the last residue or extract to a muffle, and burn at a low red heat to an ash, or the ignition may be accomplished with care over a direct flame turned low. Cool ihe dish and weigh. Determination of Solubility and Alkalinity of the Ash. — Smithes Method.* — Twenty-five cc. of the vinegar arc evaporated to dryness in a tared platinum dish, ignited, cooled, and the ash weighed. The ash is then repeatedly extracted with hot water by washing into a Gooch crucible provided with a layer of asbestos (previously ignited in the crucible, cooled, and weighed) or upon an ash-free filter. Dry the Gooch or filter, ignite, cool, and weigh the insoluble ash. The aqueous extract is titrated directly with tenth-normal acid, using methyl orange as an indicator, or treated by adding an excess of tenth-normal hydrochloric acid, boiling and titrat- ing back with tenth-normal sodium hydroxide, using phenolphthalein. Express the alkalinity in terms of 100 grams of the vinegar, by multiplying by 4 the number of cubic centimeters of acid required to neutralize. Determination of Phosphoric Acid.f — Extract repeatedly the insoluble ash as obtained in the preceding section with hot water acidulated with nitric acid, and acidify with nitric acid the neutralized solution of the * Jour. Am. Chem. Soc, 20, p. 5. t U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 12. yiNEGAR. 765 soluble dsh. Add to each solution 15 grams of ammonium nitrate, heat to boiling, and precipitate the phosphoric acid with 50 cc. of ammonium molybdate (reagent No. 53). Digest for an hour at a temperature of about 65°, filter, and wash with cold water. Dissolve the precipitate on the filter with ammonia and hot water, and wash into a beaker to a bulk of not more than 100 cc. Nearly neutralize with hydrochloric acid, cool, and add slowly magnesia mixture (reagent No. 164) drop by drop while stirring vigorously. After fifteen minutes add 30 cc. of ammonia (specific gravity 0.96), let stand for at least two hours, filter on a Gooch crucible, wash with 2.5% ammonia till practically free from chlorides, ignite, and weigh as Mg2P207. Express results in terms of milligrams of phosphoric anhydride in the soluble and insoluble vinegar ash from 100 grams of vinegar. Phosphoric acid in the soluble and insoluble ash may be conveniently determined also by the uranium acetate method, page 725. Determination of Nitrogen. — Concentrate from 50 to 100 cc. of vinegar to a syrupy consistency, and proceed as directed under the Kjeldahl or Gunning method, page 69. Determination of Total Acidity. — Six cc. of vinegar are carefully measured from a pipette into a white porcelain dish and diluted with water. Using phenolphthalein as an indicator, titrate with tenth-normal sodium hydroxide. The number of cubic centimeters of the latter required to neutralize, divided by 10, expresses the acidity in terms of percentage of acetic acid. Approximate Determination of Vinegar Acidity by Lime Water. — It has generally been considered difficult for vinegar dealers and others who desire to estimate the acidity of their vinegar to do this themselves, in that it has been necessary to obtain for the purpose a carefully standard- ized alkaline solution, the exact strength of which it is impossible for them to determine. It has been found that very satisfactory, though of course not abso- lutely accurate, results may be obtained by the use of ordinary lime water, which any one may easily prepare by making a saturated solution of ordinary air-slaked lime. The strength of such a solution is very nearly constant, and has been found to be about ^t\t of the normal. If, there- fore, it is not easy to obtain exactly normal or tenth-normal alkali, approx- imate figures may be obtained by employing such a saturated lime water. If 2.75 cc. of vinegar are titrated with lime water contained in a burette, using phenolphthalein as an indicator, the number of cubic centimeters 766 FOOD INSPECTION AND ANALYSIS. of the lime water necessary to neutralize the vinegar, divided by lo, gives the percentage of acetic acid in the vinegar. To make sure that the lime water is saturated, an excess of lime should always be present in the reagent bottle. Detennination of Volatile and Fixed Acids. — Thirty cc. of the vine- gar are transferred to a distilling-flask and subjected to distillation, using a current of steam. Receive the distillate in a 25-cc. graduated cylinder. After 15 cc. have passed over, test from time to time the drops of distillate as they fall into the receiving vessel with litmus-paper, and when free from acid discontinue the distillation. Note the volume of the distillate, mix by shaking, and transfer one-fifth to a white porcelain dish. Titrate as in the case of total acidity, expressing the volatile acids as acetic. Calculate the fixed acid, expressed in the case of cider vinegar as malic, by subtracting the percentage of volatile acid from the percentage of total acid, and multiplying the result by the factor 1.117. In the case of wine vinegar, express as tartaric acid by using the factor 1.25. To express acidity in terms of sulphuric acid, multiply the percentage of acetic acid by 0.817. Determination of Alcohol. — Alcohol is present in very small amounts in fruit vinegar that has not been completely acetified. Frear recom- mends concentrating the distillates as follows: Neutralize 100 cc. of the sample and distill off 40 cc. Then redistill the distillate till 20 cc. have gone over. Cool to 15.6° C. and make up to 20 cc. with distilled water. Determine the specific gravity with a lo-cc. pycnometer, and ascertain from the table on page 661 the per cent by weight of alcohol corresponding to the specific gravity. The percentage in the last distil- late, divided by 5, expresses the amount of alcohol in the vinegar. Detection of Free Mineral Acids. — The ash of genuine cider vinegar is always alkaline. If the ash is neutral, free mineral acids are doubtless present. For their detection the following is a modification of Brannt's method of procedure: Add to 50 cc. of the vinegar in an Erlenmeyer flask a small bit of starch the size of a wheat-grain, and shake to disseminate it through tlie fluid. Boil for some minutes, cool, and add a drop of iodine solution. If a blue coloration occurs, no mineral acid is present. In the presence of an appreciable amount of mineral acid, the starch will be converted to dextrin and sugar, and no coloration will be produced by the iodine. Frear^s Method-. — Add 5 or 10 cc. of water to 5 cc. of the vinegar, and l^INEG/IR. 767 to the mixture add a few drops of a solution of methyl violet (one part of methyl violet 2B in 100,000 parts of water). In the presence of mineral acids, a blue or green coloration will be produced. Dstermination of Free Mineral Acids. — Hehncr's Method* —To a weighed quantity of the sample add an excess of decinormal alkali, evap- orate to dryness, incinerate, and titrate the ash with decinormal acid. The difference between the number of cubic centimeters of alkali added in tiie first place, and the number of cubic centimeters needed to titrate the ash, represents the equivalent of the free acid present. Detection and Determination of Sulphuric Acid. — This is determined as barium sulphate by the addition, of barium chloride solution. A slight cloudiness on the addition of the reagent indicates the presence of small quantities of sulphate as an impurity, rather than free sulphuric acid. If a minute quantity of free sulphuric acid be present, a rather heavy white cloud on the addition of the barium chloride wall be formed, which slowly settles out. According to Brannt, if the quantity of sul- phuric acid is more than one part in a thousand, the sulphate of barium formed by addition of the reagent produces a copious precipitate that rapidly falls to the bottom of the receptacle. This may be filtered, washed, ignited, and weighed in the usual manner. Detection of Free Hydrochloric Acid.— Distill off half of a measured volume of vinegar into the receiving-flask of a distillation apparatus, and to the distillate add a few drops of nitrate of silver reagent. A pre- cipitate indicates hydrochloric acid. Detection of Malic Acid (Free or Combined). — Absence of malic acid may be assured, if no precipitate occurs with neutral acetate of lead, when a few drops of a solution of this reagent are added to the vinegai-. In the presence of malic acid, as in the case of a pure cider vinegar, the precipitate which is formed with lead acetate is flocculent, forms at once, and is of considerable amount. In pure cider vinegar the precipitate will settle to the bottom of the test-tube, leaving a clear supernatant liquid within ten minutes. Unfortunately the acetate of lead test is a negative one, in that several organic acids other than malic will cause a precipitate, as, for instance, tartaric and saccharic acids, the former being found in wine and the latter in molasses vinegar. Malt vinegar also gives a copious precipitate with lead acetate, due to phosphoric acid. The writer employs the following test t for detecting malic acid in * Analyst, i, 1877, p. 105. f An. Rep. Mass. State Board of Health, 1902, p. 4S5. Food and Drug Reprint, p. ^^. 768 FOOD INSPECTION ^ND ANALYSIS. vinegar: Add a few drops of a io% solution of calcium chloride to some of the vinegar in a test-tube, and make the mixture slightly alkaline with ammonia. Filter off the precipitate that occurs at this point, to the filtrate add two or three volumes of 95% alcohol, and heat to boiling. A copious, flocculent precipi:;ate of calcium malate will form, if mahc acid be pre::ent, settling to the bottom of the tube in a few minutes. A precipitate will occur in malt and glucose vinegar, due to dextrin. To confirm the presence of malic acid, filter, wash the precipitate with a little alcohol, dry, dissolve it in strong nitric acid in a porcelain evaporating-dish, and evaporate to diyness over the water-bath, forming calcium oxalate. Boil the residue with sodium carbonate, filter, acidify the filtrate with acetic acid, boil to expel the carbon dioxide, and add a solution of calcium sulphate. A precipitate of calci.im oxalate confirms the presence of malic aci i. For the determination of malic acid proceed as directed on page 702. Lead Precipitate. — Hortvet Number. — The quantitative measurement of the precipitate formed with lead acetate, or subacetate, is of con- siderable importance. Even though the precipitate formed may not be due as was long thought to malic acid, but may be due to phosphoric acid (though this has not been fully proved), it nevertheless remains a fact that the qualitative lead acetate test is one of the most important of all in judging the purity of cider vinegar. The lead precipitate is best measured as follows: To 25 cc. of the vinegar add 2.5 cc. of U. S. P. subacetate of lead solution. Shake and whirl in a graduated Hortvet tube in the centrifugal machine, and read the volume of the precipitate in the bottom of the tube. The results expressed in cc. on thirty samples of pure cider vinegar are summarized as follows: Highest, 1.4; lowest, 0.5; average, 0.84. The lead number of adulterated cider vinegar runs from a mere trace to 0.5 and some- times higher. Winton's Lead Number. — This is determined by the method de- scribed for maple products, page 628. Bailey* obtained by this method the following results: Cider vinegar (8 samples) 0.075 to o- 290 Malt vinegar (3 samples) o. 158 to o. 548 Distilled vinegar (i sample) 0.018 * A. O. A. C. Proc, 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 27. VINEGAR. 769 Hickey * follows the same method, except that he employs only 5 cc. of standard lead subacetate solution and determines the lead in 50 cc. of the filtrate. The lead number found by him in twenty samples of cider vinegar varied from 0.076 to 0.166. Determination of Acid Tartrate of Potassium. — Berthelot and Fleu- rien's Method.] — Twenty-five cc. of the vinegar are evaporated on the water-bath to syrupy consistency, and the residue is dissolved in water and made up to its original volume. It is then transferred to a 250-cc. Erlenmeyer flask, and 100 cc. of a mixture of equal parts of strong alcohol and ether are added, the flask is corked, shaken, and set on ice or in a cold place for forty-eight hours. At the end of this time, if a crystalline precipitate has gathered, the supernatant liquid is decanted upon a filter, and finally the precipitate is washed upon it by a fresh quantity of the ether-alcohol mixture, and the washing continued with this reagent till practically free from acid. The filter and its contents are then trans- ferred to the original flask, and the tartrate is dissolved in boiling water, after which the solution is titrated in the same flask with tenth-normal sodium hydroxide, using phenolphthalein as an indicator. Multiply the number of cubic centimeters of alkali required to neutralize by the factor 0.0188, and the quotient expresses the grams of bitartrate of potash in the sample. Multiply this by 4 to obtain the percentage present. Polarization and Determination of Sugar. — If the vinegar is light- colored and quite free from turbidity, it may sometimes be polarized undi- luted in the loo-mm. tube. Vinegar may often be sufficiently clarified for polarization by filtering twice through the same filter. It is, how- ever, best to add 10% of basic lead acetate solution, and to filter before polarizing, thus removing the malic or tartaric acids which may have a slight effect on the polarization. In case of dark-colored or turbid samples, add to 50 cc. of the sample 5 cc. of about equal quantities of lead subacetate and alumina cream, shake, filter, and polarize in a 200- mm. tube, adding 10% to the reading on account of the dilution. The polarization value of the vinegar is conveniently expressed in terms of actual direct reading obtained by the undiluted sample in a 200- or 400-mm. tube. If the invert reading is desired for calculation of sucrose or com- mercial glucose, subject the sample to inversion with hydrochloric acid and heat, as in the case of sugars. * Ibid. t Girard et Dupre, Analyse des Matieres Alimenlaires, p. 128. 770 FOOD INSPECTION AND ANALYSIS. For the determination of sucrose, use Clerget's formula (p. 588), calculating the true direct and invert readings from the direct and invert readings of the undiluted vinegar on the basis of the normal weight of the sample, by multiplying the obtained readings by 0.26 in the case of the Soleil-Ventzke instrument. Determination of Reducing Matter before and after Inversion.— Measure two portions of 25 cc. each into 100 cc. flasks. Dilute one por- tion with 25 cc. of water, add 5 cc. of concentrated hydrochloric acid and invert in the usual manner. Neutralize both portions with sodium hydroxide, clear with normal lead acetate, remove the excess of lead with potassium sulphate or carbonate, and make up to the mark. Determine reducing sugars in each portion by the Munson and Walker method (p. 598) and calculate as invert sugar. Determination of Pentosans.— Place 100 cc. of the vinegar in a flask, add 43 cc. of concentrated hydrochloric acid (sp.gr. 1.19) and proceed as described on page 286. Determination of Glycerin. — The glycerin is extracted by essentially the same process as is used for dry wines (p. 703) and determined by the Hehner method modified by Richardson and Jaffe * and Low. These processes have been adapted to vinegar analysis by Ross f as follows : Standard Solutions. — i. Strong Bichromate. — Dissolve 74.56 grams of dry, recrystallized potassium bichromate in water, add 150 cc. concen- trated sulphuric acid, cool, make up to 1000 cc. at 20° C, and determine the specific gravity at 20^/20° C; i cc. =0.01 gram glycerin. Accurate measurements being difficult owing to changes in room-temperature it is well to use weighed amounts of the solution from a weight burette, dividing by the specific gravity to obtain the volume used. The solution has an apparent expansion in glass of 0.0005 (or 0.05%) for each degree centigrade. The solution may be measured if this correction is made. 2. Dilute Bichromate. — Introduce a weighed amount (12.5 times the specific gravity) of the strong bichromate from a weight burette into a 250 cc. glass-stoppered volumetric flask, make up to the mark with water at room temperature; 20 cc. =1 cc. of the strong solution. If slightly more than 12.5 cc. equivalent is used, make up to the mark and then add the required amount of water to make one-twentieth dilution. 3. Ferrous Ammonium Sulphate. — Dissolve 30 grams of the crystallized salt in water, add 50 cc. of concentrated sulphuric acid, cool, and dilute * Jour. Soc. Chem. Ind. 17, 1898, p. 330. t Proc. A.O.A.C. 1910. U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 61. l^INEGAR. 771 to 1000 cc. at room temperature ; i cc. = approximately i cc. of the dilute bichromate. Owing to daily changes in strength it should be standardized against the bichromate whenever used. Extraction of Glycerin. — Make all evaporations on a water-bath kept at 85° to 90° C. Evaporate 100 cc. of the vinegar to about 5 cc, add 20 cc. of water and again evaporate to about 5 cc. to expel acetic acid. AAA about 5 grams of fine sand and 15 cc. of milk of lime (freshly prepared and containing about 15% of calcium oxide), and evaporate nearly, but not quite, to dryness, with frequent stirring, avoiding formation of dry crust. Rub into a homogeneous paste with 5 cc. of hot water, add 45 cc. of absolute alcohol, washing down paste adhering to the sides of the dish, and stir thoroughly. Heat the mixture on a water-bath with con- stant stirring to incipient boiling, decant onto a 12.5 cm, fluted filter, wash twice by decantation and finally on the filter with 90% alcohol up to about 150 cc, or, instead of filtering, centrifuge and wash three times. Evaporate to a sirup, dissolve in 10 cc of absolute alcohol, and wash into a 50 cc. glass-stoppered cylinder with two 5 cc. portions of abso- lute alcohol. Add three portions of 10 cc. each of absolute ether, thor- oughly shaking after each addition. Let stand until clear, then pour off through a filter, and wash the cylinder and filter with mixed absolute alcohol and absolute ether (1:1.5), If a heavy precipitate is observed in the cylinder, it is well to centrifuge at low speed and decant the clear liquid through a filter. Add 20 cc, of the mixture of absolute alcohol and absolute ether to the precipitate in the cylinder, shake thoroughly, centrifuge and decant, repeating three times. Evaporate filtrate and washings at 85^-90° C, to about 5 cc; dilute and evaporate to 5 cc. three times, using respectively 20, 20 and 10 cc. of water. Wash residue with hot water into a 50 cc. volumetric flask, cool, add silver carbonate freshly precipitated from o.i gram of silver sulphate, shake occasionally, and allow to stand 10 minutes; then add 0.5 cc of lead subacetate solu- tion, shake occasionafly, and allow to stand 10 minutes. Make up to the mark, shake well, filter, rejecting the first portion of the filtrate, and pipette off 25 cc of the clear filtrate into a 250 cc. glass-stoppered volumetric flask. Precipitate the excess of lead with i cc. of concentrated sulphuric acid, and determine the glycerin by the following method : Determination. — From a weight burette introduce into the 250 cc flask, containing the 25 cc. of purified glycerin solution, a weighed amount of the strong bichromate solution (with ordinary vinegar 30-35 cc) suf- ficient to leave about 12.5 cc. in excess, carefully add 24 cc. of concentrated 772 FOOD INSPECTION AND ANALYSIS. sulphuric acid, rotating gently to mix and avoid ebullition, then heat in boiling-water bath for exactly 20 minutes. Dilute at once, cool, and make up to mark at room temperature. The oxidation is a trifle more complete if only 15 cc. of concentrated sulphuric acid are added and the digestion 13 continued for at least 2 hours. Standardize the ferrous ammonium sulphate solution against the dilute bichromate by introducing from burettes approximately 20 cc. of each into a beaker containing 100 cc. of water. Complete the titration, using potassium ferricyanide solution (0.5 to 1%) as indicator on a porcelain spot plate. Calculate the volume {F) of ferrous ammonium sulphate equivalent to 20 cc. of the dilute and, consequently, to i cc. of the strong bichromate solution. Substitute for the dilute bichromate a burette containing the oxidized glycerin with excess of bichromate solution, and ascertain how many cubic centimeters of it are equivalent to F cc. of the ferrous ammonium sulphate solution, and therefore to i cc. of the strong bichromate. Then 250 divided by this last equivalent equals the number of cubic centimeters excess of the strong bichromate present in the 250 cc. flask after oxidation of the glycerin. The number of cubic centimeters of strong bichromate added, minus the excess found after oxidation, multiplied by o.oi equals the weight of glycerin in the 25 cc. of purified solution used in the determination; this result, multiplied by 2, gives the weight of glycerin in grams per 100 cc. of the vinegar. ADULTERATION OF VINEGAR. Standards of Purity. — In England, where the principal vinegar is- malt vinegar, the legal standards are considerably different from those in force in France and Germany, where wine vinegar is prevalent. These differ again from the requirements found in the United States and Can- ada, where cider vinegar is the chief product. Most of the state food laws fix a standard for the acidity of cider vinegar varying from 3.5 to 4.5 per cent of acetic acid, and in most cases also a minimum standard for total solids or residue of from 1.5 to 2 per cent. Special laws stipulate furthermore in some states that cider vine- gar, sold as such, must be exclusively the product of pure apple cider. In such cases cider vinegar may be adulterated by non-conformance to the standard in either acidity or solids or both, while yet it may be exclusively made from pure apple cider. This may be due either to actual watering or to incomplete acetification. On the other hand, yiNEGAR. 773 so-calied cider vinegar may be of legal standard as to solids and acidity, an d yet be entirely spurious. Following are the U. S. standards for the various vinegars: Vinegar, Cider Vinegar^ Apple Vinegar, is the product made by the alcoholic and subsequent acetous fermentations of the juice of apples, is laevo-rotatory, and contains not less than 4 grams of acetic acid, not less than 1.6 grams of apple solids, of which not more than 50% are reducing sugars, and not less than 0.25 gram of apple ash in 100 cc. (20° C.) ; and the water-soluble ash from 100 cc. (20° C.) of the vinegar contains not less than 10 milligrams of phosphoric acid (P2O5), and requires not less than 30 cc. of decinormal acid to neutralize its alkalinity. Wine Vinegar, Grape Vinegar, is the product made by the alcoholic and subsequent acetous fermentations of the juice of grapes, and con- tains in 100 cc. (20° C), not less than 4 grams of acetic acid, not less than i.o gram of grape solids, and not less than 0.13 gram ot graps ash. Malt Vinegar is the product made by the alcoholic and subsequent acetous fermentations, without distillation, of an infusion of barley malt, or cereals whose starch has been converted by malt, is dextro-rotatory, and contains, in 100 cc. (20° C), not less than 4 grams of acetic acid, not less than 2 grams of sohds, and not less than 0,2 gram of ash; and the water-soluble ash from 100 cc. (20° C), of the vinegar contains not less than 9 milhgrams of phosphoric acid (P2O5), and requires not less than 4 cc, of decinormal acid to neutralize its alkalinity. Sugar Vinegar is the product made by the alcoholic and subsequent acetous fermentations of solutions of sugar, syrup, molasses, or refiners' syrup, and contains, in 100 cc. (20° C), not less than 4 grams of acetic acid. Glucose Vinegar is the product made by the alcoholic and subsequent acetous fermentations of solutions of starch sugar or glucose, is dextro- rotatory, and contains, in 100 cc (20° C), not less than 4 grams of acetic acid. Spirit Vinegar, Distilled Vinegar, Grain Vinegar, is the product made by the acetous fermentation of dilute distilled alcohol, and contains, in 100 re. (20° C), not less than 4 grams of acetic acid. Accidental Adulteration of vinegar may result in the presence of injuri- ous metallic salts, such as of copper, lead, or zinc, derived from vessels or utensils used in the manufacture of vinegar, or even minute traces of arsenic may be found, when glucose has been employed as an ingredient 774 FOOD INSPECTION /tND ^NALYilS. •or source of the vinegar, the arsenic being in this case probably due to impure sulphuric acid used in the manufacture of the glucose. Willful or Fraudulent Adulteration is, however, common, in which misbranded vinegar is sold under names suggesting a class other than that to which it really belongs, or wherein entirely artificial substitutes are made up for pure cider, malt, or wine vinegar, in which the color, residue, and acid principle may be either or all of spurious origin. Artificial Cider Vinegar is in most cases readily detected, though very ingenious imitations are on the market, involving not a little skill and chemical knowledge in their manufacture. Entirely artificial substitutes for cider vinegar are frequently made up of spirit vinegar, colored with caramel, and having the solids rein- forced by apple jelly, made for the most part out of exhausted apple pomace, which is the residue left after the apple-stock has been sub- jected to one and sometimes two pressings. The jelly used for this purpose is not infrequently made up with commercial glucose. All grades of adulterated vinegar are to be found, from the wholly spurious substitute above described, to the varieties in which cider vinegar is itself present, but is pieced out or reinforced by the admixture of coloring matter, mineral acid, wood vinegar, or of molasses or glucose vinegar. Acetic ether is sometimes employed to impart flavor to the product. All the characteristics of a pure cider vinegar are difficult to duplicate artificially, though some of them may be. Character of the Residue. — The residue of pure cider vinegar should be thick, light brown in color, of a \'iscid or mucilaginous consistency, ■somewhat foamy, having an astringent acid though pleasant taste very suggestive of baked apples, which it also resembles in odor. The odor of molasses is very apparent in the residue of vinegar having sugar-house wastes, and the smell of a malt-vinegar residue is also very characteristic. If pyroligneous or wood vinegar has been introduced, the dried residue will have a tarry or smoky taste and smell. The residue of cider vinegar is very soluble in alcohol, while that of malt vinegar is only slightly soluble. Wine vinegar residues dissolve readily in alcohol, except for the granular residue of cream of tartar. If the loop of a clean platinum wire be rubbed in the vinegar residue and ignited in a colorless Bunsen flame, the color imparted will, if the vinegar has been made from pure cider exclusively, consist altogether of the pale- lilac color of a potash salt without any of the yellow sodium flame being U'lNEG/IR. •j'j^ visible. In all vinegars other than of pure cider, the sodium flame will predominate, when the residue is burnt as above. Again, the ignited residue left in the loop of wire in the case of a pure cider vinegar will form a fusible bead, having a strong alkaline reaction upon moistened test-paper, and effervescing briskly when immersed in acid. The pres- ence in vinegar of even a slight trace of added mineral acid will prevent the ignited residue from having the alkaline reaction, or effervescing with acid.* The residue of malt or beer vinegar is brown and gummy, containing a considerable quantity of dextrin. Not only are the appearance and odor of the dried vinegar residue to be particularly noted, but also the odor given off in the first stages of burning this residue to an ash. With cider vinegar the apple odor is very marked while burning. In vinegar wherein molasses products have been employed, the smell of charred sugar is usually apparent, while with glucose vinegar the smell of burnt corn predominates. On burning the residue of malt vinegar, the odor produced at first is not unlike that of toasted bread. At a later stage in the burning the vapors evolved are ver}' pungent. The Character of the Ash is of considerable importance in determin- ing the source of a sample of vinegar. The ash of pure cider and malt vinegar is quite strongly alkaline, while that of distilled and wood vinegar is only slightly alkaline. The ash of cider vinegar is high in alkaline carbonates. In cider and malt vinegar the quantity of phosphoric acid present in the ash is considerable, while only traces are present in distilled or spirit vinegar. Considerably more than half the phosphoric acid in the ash of cider vinegar is soluble, while no soluble phosphoric acid is present in the ash of spirit vinegar. The percentage of ash in total solids is of some value in judging the purity of cider vinegar. According to Frear.f if the ash of the vinegar is less than io% of the total solids, the vinegar may be suspected of having added unfermented material, while a percentage of ash less than 6 is absolute evidence that the vinegar is not genuine cider vinegar. The alkalinity of i gram of the ash of pure cider vinegar should be * Davenport, i8th An. Rep., Mass. Board of Health, 1887, p. 159. \ Report of Penn. Dept. of Agric, 1898, p 38. 776 FOOD INSPECTION AND ANALYSIS equivalent to at least 65 cc. of tenth-normal acid. At least 50% of: the phosphates in the ash should be soluble in water. Character of the Sugars. — One of the most important steps in es- tablishing the source of a vinegar consists in subjecting it to polariza- tion (p. 769). From the nature of the sugar-content of the apple juice, not only v^hen freshly expressed, but also when allowed to undergo alcoholic fermentation, and, furthermore, after it has gone over into vinegar, the polarization through all three stages is always left-handed. Browne * has shown that the optical rotation of the freshly expressed juice of eleven varieties of apple varies from 19.24° to 49° to the left on the Ventzke scale, in a 400-mm. tube. Also that in the case of five samples of completely fermented cider, examined five or six months* after pressing, the left-handed rotation in a 400-mm. tube varied from 1.76° to 5.28°. He showed, furthermore, that a sample of pure cider jelly made up of concentrated apple juice had a left-handed rotation amounting to 21.35° i^^ ^ 200-mm. tube (20 grams made up 100 cc), and finally that four cider vinegar samples of known purity showed left- handed readings of from 0.96° to 2.94° Ventzke in a 400-mm. tube. The left-handed rotation of pure cider vinegar is a characteristic so- fixed and unalterable that a right-handed polarization of more than 0.5** may safely be assumed as evidence of adulteration. The polarization of cider vinegar, expressed in terms of 200 mm. of the undiluted sample should lie between —0.1° and —4.0° Venlzke. If the direct polarization of a sample of vinegar is right-handed, while the invert is left-handed, sugar-house wastes or molasses may be suspected as an adulterant. If both direct and invert readings are right-handed, commercial! glucose is undoubtedly present. If the polarization of the vinegar is. far to the left, unfermented cider jelly has probably been used to rein-' force the solids. Frear regards the ratio of reducing sugars after inversion to total* solids as a useful factor in discriminating between pure cider vinegar and the common artificial substitutes in which the solids of distilled vinegar are reinforced by apple jelly, or in which commercial glucose or molasses vinegars are used. When the reducing sugars after inversion form more than 25% of the entire solids, the alleged cider vinegar is undoubtedly * Bull. 58, Penn. Dept. of Agric, "A Chemical Study of the Apple and Its Pro- ducts." l^INEGAR.. Ill spurious. In pure cider vinegar the per cent of reducing sugar is the same after inversion as before. The same is true of gkicose vinegar Vinegar containing added molasses or cane sugar will, however, naturally show an increase in reducing sugar after inversion. A large content of alcohol in cider vinegar, otherwise showing the •constants of pure vinegar except for the low acidity, would indicate incom- plete acetification. A high content of nitrogen is characteristic of malt vinegar. Data of analyses of samples of vinegar examined in the Food and Drug Department of the Massachusetts State Board of Health are given in the tables on this page and the next. The table below shows in sum- marized form the results obtained from the examination of eighty-four samples of undoubtedly pure cider vinegar examined in 1901.* CIDER VINEGAR FOUND PURE. Acid (Percent). Solids (Per Cent). Ash (Per Cent). Polarization. Maximum 6.36 4-50 4.84 4.00 2.01 2-43 0.58 o.iq 0.38 -5-4 -0.4 — 2.0 Minimum Mean The second table includes samples of adulterated vinegar, sold for cider vinegar, none of which were probably made from cider. It will Tdc noticed that in several of the samples the amount of glucose was abnormally large, as is shown by the very high right-handed polarization, in one case amounting to over 12°. Direct Tests Made .on the Vinegar. — The genuine or spurious nature of cider vinegar may usually be established by direct tests with reagents on the vinegar itself. The appearance, taste, and odor of the vinegar should be noted. Brannt f applies the test of odor in vinegar as deter- mining its character, by rising out a large beaker with the sample, and' * 32d An. Rep. (1900), p. 661, Food and Drug Reprint, p. 44; 33d An. Rep. (1901), p. 467, Food and Drug Reprint, p. 47; 34th An. Rep. (1902), p. 483, Food and Drug Reprint, ip. 31. t A Practical Treatise on the Manufacture of Vinegar, p. 2 19. 778 FOOD INSPECTION AND ANALYSIS. VINEGAR NOT THE EXCLUSIVE PRODUCT OF PURE APPLE CIDER. Per Cent Per Cent Per Cent Per Cent Polarization Acetic Acid. Total Solids. Ash. Ash in Total Solids. in 200-nim. Tube. Lead Acetate. 5-9° .40 . . • • .... + 1-4 No precipitate 5-14 -36 .... .... .0 " " 5 .12 ■53 .... .... -f .6 " " 4 -83 3-7° •32 8.65 + 8.ot " " 4 .82 2.71 •13 4.80 + 9-6t Heavy precipitate*- 4 .80 1-97 .20 •10.15 + -9 Precipitate 4 80 1-03 .27 14-75 -f I.I ' ' 4 66 2.92 .20 6.49 -f 2.2 No precipitate 4 60 2-57 .... .... -f 2.6 " " 4 56 2.60 + 7-ot t 4 54 3-97 .19 4.78 + 5.6 No precipitate 4 54 3-90 -32 9.72 + 5-0 11 <( 4 54 2-94 -23 7.82 + 5-0 " " 4 54 2.70 •23 8.52 + -4 Precipitate 4 50 3-05 + 2.2 No precipitate 4 50 2.92 .22 7-52 + -9 " " 4 50 2.69 .... + 2.8 (< << 4 48 3.80 .... + I2.ot < ( <( 4- 46 2.80 .... -f 2.6 (< ( ( 4 42 2-75 .... + 3-2 Slight precipitate- 4 42 2.10 + 9-2 Precipitate 4 40 2-51 .20 II. 15 + I.I ' ' 4 40 -97 + .4 No precipitate 4- 38 -29 .... -f 1.6 " " 4- 32 .70 .09 i2!86 << ( ( 4- 08 3-35 .... + 1.2 Precipitate 3- .8 -55 + 1.8 Slight precipitate * Cider vinegar to which apple jelly containing glucose had been added for the purpose of increas- ing the solids after watering. t This sample contained a large amount of phosphate, and consequently the test for malates is obscured. J These samples polarized practically the same after as before inversion, indicating much glucose. after allowing it to stand for some hours, examining the few drops remain- ing in the beaker. The acetic acid having for the most part become volatilized, the characteristic vinous odor of pure wine vinegar would at this stage be very prominent, while that of cider vinegar would be entirely different. The odor of the two vinegars is very similar in their ordinary state. The peculiar fruity flavor of pure cider vinegar is very characteristic and not readily imitated by cheaper substitutes. Only a very slight turbidity should be produced in pure cider vinegar by the addition of either ammonium oxalate (absence of lime), barium chloride (absence of sulphuric acid or sulphate), and nitrate of silver (absence of hydrochloric acid or chlorides). VINEGAR. 779 The character of the precipitate produced by neutral lead acetate should be particularly noted. Unless it is flocculent and copious, set- tling out after a few minutes, cider vinegar is not pure, even if a marked turbidity is produced. Added apple jelly from exhausted apple pomace gives such a turbidity, and is to be suspected when not more than a cloudi- ness is produced on addition of the lead acetate reagent. Pure cider vinegar should respond in a perfectly normal manner to both the lead acetate and the calcium chloride tests for malic acid. Wood Vinegar or Pyroligneous Acid is sometimes rendered apparent by the empyreumatic or tarry taste and odor imparted to the product. When, however, the added acetic acid has been so purified that the tarry taste and odor are lacking, its presence may often be proved by the traces of furfurol which always accompany it. Test for Furfural. — A little of the vinegar is subjected to distillation,, and to the first few drops of the distillate is added a little colorless anilin solution. A fading crimson color will be produced in presence of furfuroL This reaction may sometimes be obtained upon the vinegar itself without distillation, if sufficient added wood vinegar be present. The first portion of the distillate of wood vinegar reduces permanga- nate of potassium to a marked degree. Ths Addition of Spices to vinegar in order to increase the pungency is best detected by first neutralizing the vinegar wiA sodium carbonate and then tasting. Under these conditions, the admixture of spices is rendered very apparent. Detection of Caramel. — Considerable added caramel in vinegar is apparent from the unnaturally dark color and extremely bitter taste of the residue after evaporation. Tests for caramel made on the vinegar residue, if long dried at the temperature of the water-bath, are not to be depended on as establishing the presence of added caramel, since at that temperature the decomposi- tion of the sugar may in any event cause a positive test. Caramel is detected by Crampton and Simon's and Amthor's tests (p. 752). A further indication of caramel is the reducing power of the water solution of the precipitate obtained in Amthor's test. Examination for Metallic Impurities. — Lead and Zinc are best looked for in the ash of the vinegar in cases where, like cider vinegar, the percent- age of extract is high. A large volume of the vinegar is evaporated to substantial dryness over the water-bath. This may most readily be done in a loo-cc. platinum wine-shell, adding the vinegar in successive 780 FOOD INSPECTION AND ANALYSIS. portions. To tht residue add a small amount of sodium hydroxide, and burn to an ash in a muffle, or over a low flame, using potassium nitrate if necessary, a little at a time. Take up the ash in dilute hydrochloric acid, and examine for lead and zinc as in the case of canned goods. In the case of vinegar low in extract, as in spirit vinegar, the sample may be evaporated to dr\'ness, the residue dissolved directly in dilute hydrochloric acid without ignition, and the acid solution subjected to direct examination for lead and zinc. Ccpper is best determined by electrolysis. 100 cc. of the vinegar are evaporated to a volume of about 10 cc. 'with a little sulphuric acid, filtered into a platinum dish, and subjected to electrolysis, using con- veniently the apparatus described on page 608. Arsenic. — Boil down a portion of the vinegar, to which concentrated nitric acid has been added, to a small volume, then add a few cubic centi- meters of concentrated sulphuric acid, and continue the heating till fumes of sulphuric acid show the nitric to have been driven off. Cool, dilute with water, and test in the Marsh apparatus. REFERENCES ON VINEGAR. Allen, A. H. White Wine Vinegar. Analyst, 21, 1896, p. 253. Allen, A. H., and Moor, C. G. Vinegar. Analyst, 18, 1893, pp. 180 and 240. Bersch, J. Die Essigfabrikation. Vienna, 1895. Brannt, W. Vinegar, Acetates, Cider, Fruit Wines and Preservation of Fruits. London, 1900. Browne, C. A. A Chemical Study of the Apple and Its Products. Penn. Dept. of Agric. Bui. 58, 1899. The Effects of Fermentation upon the Composition of Cider and Vinegar. Jour. Am. Chem. Soc, 25, 1903, p. 16. ■Crampton, C. a., and Simons, F. D. Detection of Caramel in Spirits and Vinegar. Jour. Am. Chem. Soc, 21, 1899, p. 355. Davenport, B. F. Analysis of Vinegar. Chem. News, 1887, 3 and 66. Doolittle, R. E., and Hess, W. H. Cider Vinegar, Its Solids and Ash. Jour. Am. Chem. Soc, 22, 1900, p. 218. Dltbois, W. L. The Fuller's Earth Test for Caramel in Vinegar. Jour. Am. Chem. Soc, 29, 1907, p. 75. Frear, W. Apple Juice, Fermented Cider and Vinegar. Penn. Dept. of Agric. Rep., 1898, p. 138. • Cider Vinegars of Pennsylvania. Penn. Dept. of Agric, Bui. 22, 1897. Vinegar. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 62. Washington, 1902. Gardner, J. Acetic Acid and Vinegar. Philadelphia., 1885. Leach, A. E., and Lythgoe, H. C. Cider Vinegar and Suggested Standards of Purity. Jour. Am. Chem. Soc, 26, 1904, p. 375. yiNEGAR. 781 Leeds, A. R. Acetic Acid in Vinegar. Jour. Am. Chem. Soc, 17, 1895, p. 741. Macfarlane, T. Vinegar. Canada Inl. Rev. Dept., Bui. 35. Ottawa, 1893. Pasteur, M. Etudes sur la Vinaigre. Paris, 1868. Sangle-Ferriere. Vinaigre. Analyse des Matieres Alimentaires (Girard), p. 263. Smith, A. W. Vinegar Analysis and Characteristics of Pure Cider Vinegar. Jour. Am. Chem. Soc, 20, 1898, p. 3. Sykes, W. J. Detection of Adulteration in Vinegar. Analyst, 16, 1891, p. 83. Connecticut Exp. Sta. An. Reports, 1897, 1898, 1899. Massachusetts State Board of Health, An. Reports, 1900, 1901, 1902, and 1903. North Carolina Exp. Station Bui. 153. CHAPTER XVII. ARTIFICIAL FOOD COLORS. The use of artificial dyestuffs in food products has greatly increased during recent years, both in degree and in variety of colors employed. Where formerly but a few well-known coloring matters, chiefly so-called vegetable colors and occasionally mineral pigments were used for this purpose, a vast array of dyes, chosen largely from the coal-tar colors, are now found in food, so that at present the exact identification of the particular dycstuff employed in all cases presents a somewhat formidable problem to the analyst. The problem may consist in determining the class to which a commercial food color or combination of colors belongs, or it may consist in isolating the color itself, and afterwards identifying it as far as possible, for the purpose of determining whether or not it is harmless within the meaning of the law. The effect of imparting to the cheaper varieties of jellies, jams, and. ketchups which flood the market such intense and striking colors that these products in no wise resemble their pure uncolored prototypes, has. a tendency in many cases to mislead the public into the idea that the genuine products are inferior by contrast, and to create a craving for unnaturally colored varieties. Indeed, the adherents to the free use of coloring matters in food assert that these brilliant hues please the eye and are hence legitimate. Objectionable Features. — With the exception of confectionery and certain dessert preparations, in which dyes may be employed purely for aesthetic considerations only (a fact which is well understood by the consumer), the use of coloring matters in food is mainly for the purpose of deceiving as to their true character. The use of dyestuffs in food is objectionable on two accounts, first as introducing in some cases materials injurious to health, and second, in nearly all cases as deceiv- ing the purchaser by concealing inferiority, or by making the goods 782 ARTIFICIAL FOOD COLORS. 783 appear of greater value than they really are. In most states the food laws regarding employment of colors are so framed, that the presence of such colors constitutes an offense under one or the other of the above heads, mainly, however, because, by reason of their use, cheaper or inferior materials are made to masquerade for the higher or genuine grades, as, for instance, when alleged currant jelly is found to consist chiefly of apple-stock and commercial glucose, colored with an artificial red dye. In such cases the analyst has merely to prove conclusively that an artificial color is present, even if he does not identify the dye itself. It is of course more satisfactory to at least show in addition whether the dye present is of vegetable origin, or is of the coal-tar variety, and in most cases this can readily be done, even if it is not easy to identify the exact color. In localities where laws prevail stipulating that what are commonly known as "mixtures" or "compounds" to be legally sold, must be labeled with the names and percentages of ingredients, the law applies to coloring matters as well as other ingredients, and the exact dye or dyes employed should appear on the label. Otherwise the product must be classed as adulterated. Toxic Effects of Colors, — Formerly the use of such pigments as chromate of lead was common in coloring confectioner}^ but lead' chromate is rarely used at present. Other mineral pigments obviously unfit for use in food by reason of their well-known poisonous effects are those which contain salts of arsenic, mercury, lead, and copper. While most of the coal-tar colors are considered harmless in themselves, some are decidedly objectionable, and should not be used in foods. Under the latter class are included, first, those in connection with the manu- facture of which arsenic, mercury, or other poisonous mineral ingredients have been used, such for example as arsenical fuchsin, and, second, those which are themselves inherently poisonous, as for instance picric acid. Fuchsin is now largely made without the aid of arsenic acid, and this variety is, perhaps, harmless. The toxic effects of many of the coal-tar colors have not been thoroughly established excepting in a negative way. Weyl has made many experiments on dogs and rabbits in which these animals have been fed with varying amounts of coloring material. In nearly all cases the doses far exceeded the amounts ordinarily taken in food, and the experiments are of value mainly in so far as they show harmless results of certain colors on the animal. It is to be regretted ..^84 POOD INSPECTION AND ANALYSIS. that physiological experiments cannot more readily be tried on human beings, so as to study the effects of administering to them such amounts as are used in food. More conclusive results (though still of a negative character) tending to establish the harmlessness of most of the coal-tar colors are given by Grandhomme * in statistics showing the condition of health of laborers in factories where these dyestuffs are made, in comparison with those engaged in other industries where poisonous materials are handled. From these it appears that the proportion of illness among the anilin- makers is remarkably small. In the case of coloring confectionery by the use of mineral pigments, a considerable amount of the coloring material must be used, forming without doubt a source of danger in some cases. With coal-tar dyes, on the contrary, the case is different. One ounce of auramine, for instance, has been found sufficient to give a deep-yellow color to 2,000 pounds of confectionery, so that almost an infinitesimal amount of the actual dyestuff is taken into the system. Hence it is that very little danger need be apprehended from the use of most coal-tar colors in food, objec- tionable as they certainly are as a commercial fraud. Injurious and Non-injurious Colors. — Various countries have enacted specific laws regulating the use of coloring matters in foods, especially England, France, Germany, Austria, and Italy. In some cases attempts have been made to specify harmful and harmless colors. The National Confectioners' Association of the United States has compiled a useful classified list of injurious and harmless colors,! the classification being based largely on the results of experiments by Weyl and Konig, as well as upon the Resolutions of the Association of Swiss Chemists, and on the French Ordinances regarding food colors. The list is as follows: HARMFUL MINERAL COLORS. Compounds 0} Copper. — Blue ashes, mountain blue, etc. Compounds 0} Lead. — Massicot, red lead, white lead, Cassel yellow, Paris yellow. Turner yellow, Naples yellow, sulphates of lead, chrome yellow, Cologne yellow, etc. Compounds 0} Barium. — Ultramarine yellow, etc. * Weyl, Sanitary Relations of the Coal-tar Colors, pp. 28-30. t Colors in Confectionery. An Official Circular from the Executive Committee of the National Confectioners' Association of the U. S., 1899. ylRTIFICUL FOOD COLORS. 785 Compounds 0} Mercury. — Vermilion, etc. Compounds of Arsenic. — Scheele's green, Schweinfurth green, etc. In Other Words colors in whose preparation mercury, lead, copper, arsenic, antimony, tin, zinc, chromium, and barium compounds are used. HARMFUL ORGANIC COLORS. Red Colors. — Ponceau t,RB. — Ponceau B extra, fast ponceau B, new Ted L, scarlet EC, imperial scarlet, old scarlet, Biebrich scarlet. Crocein Scarlet t,B. — Ponceau 4RB. Cochenille Red A. — Crocein scarlet 4B and G, brilliant scarlet, brilliant ponceau 4R, ponceau 4R, ponceau brilliant 4R, new coccin, scarlet. Crocein Scarlet 'jB. — Crocein scarlet 8B, ponceau 6RB. Crocein scarlet O extra. Safranin. — Safranin T, safranin extra G, safranin G extra GGSS, safranin GOOO, safranin FF extra No. O, safranin cone, safranin AG extra, safranin AGT extra, anilin pink. Yellow Colors. — Gum gutta. Picric acid. Martius Yellow. — Naphthylamin yellow, jaune d'or, Manchester yel- low, naphthalin yellow, naphthol yellow, jaune naphthol. Acme Yellow. — Chrysoin, chryseolin yellow T, gold yellow, resorcin yellow, acid yellow RS, tropaeolin O, jaune II. Victoria Yellow. — Victoria orange, anilin orange, dinitrocresol, saf- fron substitute, golden yellow. Orange II. — Orange No. 2, orange P, orange extra, orange A, orange G, acid orange, gold orange, mandarin G extra, beta-naphtholorange, tropaeolin OOO No. 2, mandarin, chiysaurin. Metanil Yellow. — Orange MN, tropaeolin G, Victoria yellow (O double cone), jaune G (metanil extra). Sudan I. — Carminaph. Orange IV. — Orange No. 4, orange N, orange GS, new yellow, acid yellow D, tropaeolin 00, fast yellow, diphenylorange, diphenylamine orange, jaune d'anilin, anilin yellow. Green Colors. — Naphthol green B. Blue Colors. — Methylene blue BBG. — Methylene blue BB, in powder extra, methylene blue DBB extra, methylene blue BB (crystalline) ethylene blue. 786 FOOD INSPECTION AND ANALYSIS. Brown Colors. — Bismarck Brown. — Bismarck brown G, Manchester brown, phenylen brown, vesuvin, anilin brown, leather brown, cinnamon brown, canelle, English brown, gold brown. Vesuvin B. — Manchester brown EE, Manchester brown PS, Bis- marck brown, Bismarck brown T, brun Bismarck EE. Fast Brown G. — Acid brown. Chrysoidin. — Chrysoidin G, chrysoidin R, chrysoidin J, chrysoidin Y. HARMLESS MINERAL COLORS. Blue Colors. — Ultramarine blue. Violet Colors. — Ultramarine violet. Brown Colors. — Manganese brown. Chocolate-brown and colors of a similar nature have as their basis natural or precipitated oxide of iron, which in an impure condition may have small quantities of arsenic in its composition. It is possible with proper care to secure a raw material entirely free from this objectionable element, and no oxide of iron containing any traces of arsenic should be used in the preparation of color. Green Colors. — Ultramarine green. HARMLESS ORGANIC COLORS. Red Colors. — Cochineal carmine. Carthamic acid (from saffron). Redwood. Artificial alizarin and purpurin. Cherry and beet juices. Eosin. — Eosin A, eosin G extra, eosin GGF, eosin water soluble, eosin 3J, eosin 4J extra, eosin extra, eosin KS ord., eosin DH, eosin JJF. Erythrosin. — Erythrosin D, erythrosin B, pyrosin B, primrose solu- ble, eosin bluish, eosin J, dianthin B. Rose Bengale. — Rose bengale N, Rose bengale AT, rose bengale G, bengalrosa. Phloxin. — Phloxin TA, eosin blue, cyanosin, eosin loB. Bordeaux and Ponceau reds, resulting from the action of naphthol- sulphonic acids on diazoxylene : Ponceau 2R. — Ponceau G, ponceau GR. Ponceau R. — Brilliant ponceau G, ponceau J. ARTIFICIAL FOOD COLORS, 787 Bordeaux B. — Fast red B, Bordeaux R extra. Cerasin. — Rouge B. Ponceau 2G. — Brilliant ponceau GG, ponceau JJ. Fuchsin S. — x\cid magenta, rubin S, fuchsin acide (free from arsenic). Archil Substitute. — Naphthion red. Orange I. — Orange No. i, naphtholorange, alpha-naphtholorange, tropaeolin OOO No. i. Congo red. Azoruhin S. — Azorubin, azorubin A, azoacidrubin, fast red C, car- moisin, brilliant carmoisin O, rouge rubin A. Fast Red D. — Fast red EB, fast red NS, amaranth, azoacidrubin 2B, Bordeaux DH, Bordeaux S, naphthol red S, naphthol red O, Victoria ruby, wool red (extra), oenanthinin. Fast- Red. — Fast red E, fast red S, acid carmoisin S. Ponceau 4GB. — Crocein orange, brilliant orange G, orange GRX, pyrotin orange, orange ENL. Fuchsin. Meianitrazoiin. Yellow and Orange Colors. — Annatto. Saffron. SaJjJower. Turmeric. Naphthol Yellow S. — Citronin A, sulphur yellow S, jaune acide, jaune acide C, anilin yellow, succinine, saffron-yellow, solid yellow, acid yellow S. Brilliant Yellow. — (Sch.) Ponceau 4GB. — Crocein orange, brilliant orange G, orange GRX, ipyrotin orange, orange ENL. Fast Yellow. — Fast yellow G, fast yellow (greenish), fast yellow S, acid yellow, new yellow L. Fast Yellow R. — Fast yellow, yellow W. Azarin S. Orange I. — Orange No. i, naphtholorange, alpha-naphtholorange, tropaeolin OOO No. i. Orange. — Orange GT, orange RN, brilliant orange O, orange N. Mixtures of harmless red and yellow colors. Green Colors. — Spinach green. Chinese green. Malachite Green. — Malachite green B, benzaldehyde green, new Vic- 788 FOOD INSPECTION AND ANALYSIS. toria green, new green, solid green crystals, solid green O, diamond green^ bitter amend oil green, fast green. Dinitrosoresorcin. — Solid green O in paste, dark green, chlorine green, Russia green, Alsace green, fast green, resorcinol green. Mixtures of harmless blue and yellow colors. Blue Colors. — Indigo. Litmus. Archil blue. Gentian Blue 6B. — Spirit blue, spirit blue FCS, opal blue, blue lumiere, Hessian blue, light blue. Coupiers Blue. — Fast blue R and B, soHd blue RR and B, indigin DF, indulin (soluble in alcohol) , indophenin extra, blue CB (soluble in alcohol), nigrosin (soluble in alcohol), noir CNN. In General such blues as are derived from triphenylrosaniUn or from diphenylamin. Violet Colors. — Paris Violet. — Methyl violet B and 2B, methyl violet V3, pyoktanin coeruleum, malbery blue. Wool black. Naphthol black P. Azoblue. Mauvein. — Rosolan, violet paste, chrome violet, anilin violet, anilin purple, Perkins violet, indisin, phenamin, purpurin, tyralin, tyrian purple, lydin. Brown Colors. — Caramel. Licorice. Chrysamin R. Use of Colors in Confectionery. — Regarding the choice of colors for use in confectioneiy and precautions to be observed in their use, the Confectioners' Association has offered the following considerations: First. That coal-tar colors are specially adapted to the wants of confectioners on account of their brilliancy, permanency, and high color- ing power, by reason of which last-named quality only infinitesimal amounts of color need be or can be used to give the desired effects. Second. That there is no evidence to show that any poisonous or hurtful colorings have in recent years been found in confectionery. Reports of deaths from poisoned candy are only too frequently made, but no autopsy has ever been published confirming them. Third. That while the exceedingly small proportions of color used in confectionery constitute a practical safeguard to the public health, con- yiRTIFJCML FOOD COLORS. 789. fectioners are in duty bound to provide against all possible contingencies of harm, by using the utmost care in obtaining absolutely non-poisonous colors, buying only from color-dealers of established reputation and unquestioned responsibility, whose colors are tested at frequent intervals, and are vouched for by competent chemists. Confectioners should require that a guarantee be put upon each package of color, stating not only that the contents are non-poisonous, but also that they will not in any way interfere with digestion or injure health. Fourth. Any illegitimate use of coloring matter in comtctionery as a substitute for chocolate or any other material or ingredient, or for the purpose of adding bulk or increasing the weight of the confectionery in which it is incorporated, should not be permitted or countenanced. Both the letter and the spirit of these laws should clearly prevent the illegitimate use of coal-tar colors or of earth colors, such, for example, as chocolate-brown, coconole brown, or chocolatina. Fijth. That color-dealers furnishing colors to confectioners should publish printed lists of their colors under the various names and titles by which they are known and offered for sale, accompanying such lists with ample certifications by competent chemists to their purity and suit- ableness for coloring confectionery and other articles of food. They should also attach to each package or other container of color a guar- antee that it does not contain anything injurious to health. VEGETABLE COLORS. These with a few mineral pigments and cochineal were formerly almost exclusively used for coloring food products, and are still used to some extent. Most of the vegetable colors, according to L. Robin,* react with ammonia to form a coloration, usually passing from violet to blue, then to a brownish green, when the ammonia is added little by little in excess to the color in solution. If by the addition of ammonia to a solution of an unknown color the green coloration does not result, the presence may be suspected of orchil or cudbear, logwood, cochineal, or a coal-tar dye. The following vegetable colors are occasionally found in food, with some of the reactions in aqueous solution, as given by Robin: * Girard, Analyse des Matieres Alimentaires, pp. 678, 679. 79° FOOD INSPECTION AND ANALYSIS. RED COLORS. Nature of Color. Ammonia. Alum and Sodium Carbonate 20% Solution. Lake. Filtrate from Mixture of Aluminum Acetate and Sodium Carbonate. Bilberry (whor tleberry) -Beet Black currant. . . Logwood Brazil wood Raspberry Currant Blackberry Phytolacca Elderberry Dull greenish Muddy yellow, brown, or rose- red Deep green Red tinged with violet Currant-red Bluish green Yellow-brown to greenish Yellowish green Lilac Light green Greenish blue, rose-colored on edges Dull green or rose Greenish blue Blue tinged with violet Rose Rose tinged Gray to Ulac White or rose vio- let Violet Blue tinged with violet Bottle-green Rose tinged Bluish green Dull maroon to bottle-green Bluish Bluish violet Garnet Violet-blue Tinged with violet Lilac to wine color Lilac tinged with violet Red-maroon Dull violet Clear violet, pass- ing to yellow with ammonia Violet, quickly passing to blue with acetate of copper YELLOW COLORS. Nature of Color. Ammonia. Hydrochloric Acid. Alum and Carbonate of Soda 20% Solution. Lake. Persian berries Old fustic Yellow-red Very bright yellow Becomes clearer Yellowish red Brown-red Precipitate yellow- brown Yellow-orange Bright yellow pre- cipitate Becomes yellower Crimson precipitate Orange Orange Yellow-red tending to green Bright yellow Bright yellow Quercitron bark Young fustic Turmeric .......... Additional yellow vegetable colors sometimes used in foods are the following, taken from a table of Leed's,* showing reactions given by treating a few drops of an alcoholic solution of the color with an equal volume of the reagent. Most of these vegetable colors do not directly dye wool or silk a fast 'Color, but as a rule require the use of a mordant. Many of these colors may be fixed on cotton (previously mordanted by boiling in a solution * Analyst, 12, 150. ARTIFICIAL FOOD COLORS. 791 REACTIONS OF COLORING MATTERS. Coloring Matter. Concentrated H2SO4. Concentrated HNO3. H2SO4-I-HNO3. Concentrated HCl. Annatto Indigo-blue, chang- Blue, becoming Same No change, or only ing to violet colorless on standing slight dirty yel- low and brown Turmeric. . . Pure violet Violet Violet Violet, changing to original color on evaporation ol HCl Saffron Violet to cobalt Light blue, chang- Same Yellow, changing blue, changing to ing to light red- to dirty yellow reddish brown dish brown Carrot Umber brown Decolorized Same with NO2 fumes and odor of burnt sugar No change Marigold... Dark olive-green, Blue, changing in- Green Green to yellowish permanent stantly to dirty yellow-green green Safflower. '. . Light brown Partially decolor- ized Decolorized No change of aluminum acetate or potassium bichromate) by boiling the mordanted fibers in a bath of the colored solution, rendered acid by acetic acid. The dyed fibers are then examined by reagents, as in tables given on pages 806-13. Special Tests for Vegetable Colors. — Orchil and Cudbear, both ■derived from lichens, dye wool red in acid bath. The colored fiber, in the case of cudbear, is turned blue by treatment v^ith ammonia. For reactions of orchil on the fiber see table, page 809. Robin's test for orchil in aqueous solution consists in shaking it with ether, which, if orchil is present, is colored yellow. On treatment of the ether with ammonia, the yellow color is changed to blue, and, by adding acetic acid, goes over to a reddish violet. Logwood, according to Robin, in aqueous solution colors ether yellow, ,and on treating the ether with ammonia the color becomes red or faintly violet. Potassium bichromate gives a violet coloration, mingled with greenish yellow. If cotton is first mordanted by boiling with aluminum .acetate, it is dyed violet when boiled in a solution of logwood. Turmeric is best extracted from a dry residue with alcohol, which it colors yellow. The color is transferred to a piece of filter-paper by soak- ing the paper in the alcoholic tincture, the paper is dried and dipped in a dilute solution of boric acid or borax slightly acidulated with hydro- chloric acid. On again drying the paper, it will be of a cherry-red color if turmeric is present, and when touched with a drop of dilute alkali will turn dark olive. 792. FOOD INSPECTION AND /IN A LYSIS. Caramel. — Care should be taken in testing for caramel not to subject the sample to long-continued heating, even on the water-bath. Indeed caramel is sometimes developed spontaneously in saccharine food prod- ucts during their process of manufacture when heat is used, by the charring of the sugar. If solutions are to be concentrated or brought to dryness before testing for caramel, this should be done in a vacuum desiccator over sulphuric acid, or at a temperature not exceeding 70°. For detection of caramel in milk, vinegar, and liquors, special tests are given elsewhere. Fradiss Test.* — The dried residue of the sample to be tested is extracted wi.h warm, pure methyl alcohol, which, if caramel be present,, is colored brown. Filter, and to the filtrate add amyl alcohol or chloro- form. In presence of caramel, a brown flocculent precipitate is formed,, which slowly settles to the bottom of the tube. Indigo in aqueous solution turns green with ammonia. On boiling, the solution becomes bright blue. Indigo in neutral or acid solution dyes wool or silk. ANIMAL COLORS. Cochineal. — This dyestuff is used in ketchups, cordials, confections, and other food products. Robin's test for cochineal is as follows: The aqueous solution is acidulated with hydrochloric acid, and shaken out in a separatory funnel with amyl alcohol. Cochineal imparts to this solvent a yellowish color, the depth depending on the amount present. The separated amyl alcohol is washed with water till neutral, and divided into two portions. To one of these a little water is added, and then drop by drop a solution of uranium acetate, shaking each time a drop is added. In presence of cochineal the water is colored a very characteristic emerald-green color. To the other portion ammonia is added. If cochineal has been used, a violet coloration is produced. MINERAL PIGMENTS. Evidence of the presence of these pigments is usually best looked for in the ash of the suspected sample. In some cases the color may be extracted from the dried residue by water, alkah, or alcohol. Prussian Blue. — This pigment is insoluble in water. It is decom- posed and decolorized by treatment with potassium hydroxide. If the * Oestr. ungar. Zeits. Zuckcr. Ind., 1899, 28, 229-231; Abs. Zeits. f, Unters. Nahr. u- Genuss., 2, 1899, p. 881. ARTlFiaAL FOOD COLORS. 793 filtered alkaline solution of the coloring matter be treated with hydro- chloric acid and ferric chloride, a precipitate of the original Prussian blue will be produced. For reactions on the fiber see table, page 812. Ultramarine Blue is decolorized by hydrochloric acid with evolution of hydrogen sulphide, which blackens filter-paper moistened with lead acetate. For the recognition of ultramarine in sugar see page 590. For its detection on the fiber see table, page 813. Chromate of Lead has never been used to any extent in food products with the exception of confectionery. For its detection, see page 647. COAL-TAR COLORS. So many of the coal-tar dyes are adapted for use in food that it would be impossible to even name them all, especially in view of the fact that new coiors are from time to time being added to the list. No attempt will be made in the present work to giv^ the nature and composition of the dyes named, as such descriptions would lead beyond its scope. For detailed information along this line the reader is directed to the references on pp. 819 and 820, especially to the works of Schultz and Julius, Bene- dict and Knecht, Weyl, etc. About 2000 separate coal-tar dyes are at present on the market. Various classifications of these colors are attempted, based on (i), their origin, as anilin dyes, naphthalin dyes, anthracene dyes, etc.; (2), their chemical composition, as nitro, nitroso, azo, diazo, and other compounds; (3), their solubility in water and other solvents; and (4), their mode of application to the fiber, as basic dyes, acid dyes, direct cotton dyes, mor- dant dyes, etc. These dyes are sold in the form of powder, and are readily made into solutions for food colors in the case of the water-soluble varieties, and into pastes in the case of the insoluble forms. Most of the coal-tar colors employed in foods are naturally of the soluble variety, especially such as are found in jellies, jams, fruit products, canned foods, ketchups, beverages, and milk. Pastes made from insoluble dyes are adapted mainly for exterior coatings of hard substances such as candies. Colors in the dry form are to be looked for in such spices as cayenne, mustard, and mace, but a commoner method of coloring these spices high in oil is to mix with them a solution of the color in oil (usually cottonseed). Oil solutions of coal-tar dyes are also employed for coloring butter and oleomargarine. The chief concern of the food analyst, as regards artificial color is 794 POOD INSPECTION AND AN/I LYSIS. its recognition in food products. Coal-tar dyes may usually be iden- tified as such, but it is not always possible to name the particular individual dye or combination of dyes employed, even though the class to which they belong may be determined. One reason for this is that not infrequently mixtures of two or more colors are employed. Coal-tar Colors Allowed under the Federal Law.- — The use of any dye, harmless or otherwise, to color food in a manner whereby damage or inferiority is concealed is in violation of Sec. 7 of the Food and Drugs Act of June 30, 1906. The addition of all mineral or metallic dyes, and of all coal-tar dyes, other than those specially provided for, is also prohibited. Pending further investigation the following coal-tar colors are permitted in foods, provided they are certified to be true to name and to be free from mineral and metallic poisons, harmful organic constituents, and contaminations due to improper or incomplete manu- facture : * Red Shades. — 107, Amaranth [M.] [C]. Synonyms: Fast red D. {B.\ Bordeaux S. [A.], azoacidrubine 2B. [D.], fast red EB. [B.]. 56. Ponceau 3R. [A.] [B.] [M.]. Synonyms: Ponceau 4R, [A.], cumidin red, cumidin ponceau. 517. Erythrosin [B.][M.][B.S.S.]. Synonyms: Erythrosin D. [C], erythrosin B. [^.], pyrosin B. [Mo.], iodeosin B., eosin bluish, eosin J. [5.]. Orange Shade. — 85. Orange I. Synonyms: Alphanaphthol orange, naphthol orange [yl.], tropaeolin 000 No. i, orange B. [L.\. Yellow Shade. — 4. Naphthol yellow. S. [5.]. Synonyms: Naphthol yellow, acid yellow S., citronin A. [L.]. Green Shade. — 435. Light green S. F. yellowish [B.]. Synonyms: Acid green [By.] [M.] [T.M.] [O.], acid green extra cone. [C]. Blue Shade. — 692. Indigo disulphoacid. Synonyms: Indigo car- mine, indigo extract, indigotine [B.], sulphonated indigo. None of these seven colors is patented, hence their manufacture is not likely to become a monopoly. They may be used in combinations, thus securing any desired shade. For example, violet may be obtained by mixing indigo disulphoacid and one of the red colors, a blue-green by mixing indigo-disulphoacid with naphthol yellow S. or light-green S.F. and so on. * The numbers preceding the dyes are those given in Green: A Systematic Survey of the Organic Colouring Matters founded on the German of Schultz and Juhus, Londom 1904; the letters in brackets represent the manufacturers v^fho originated the names. ARTIFICIAL FOOD COLORS. 795- Detection of Coal-tar Colors in Foods. — ^There are various- methods for the separation of coloring matters from food products, and these may be divided into three general classes: First, dying silk or wool with the color by boiling the fiber in a solution of the sample to be examined; second, extracting the color from a solution of the sample by the use of an immiscible solvent ; and third, extracting the color from the dried residue of the sample by means of a suitable solvent. Of these the method of dying wool lends itself most readily to the analyst's use, by reason of its simplicity, and from the fact that almost without excep- tion coal-tar dyes adaptable for food colors are substantive dyes, being; readily taken up by wool. Basic and Acid Dyes. — The soluble coal-tar dyes are either basic or acid. Basic dyes are precipitated from their aqueous solution by tannin. Acid dyes are not so precipitated. Theoretically, all the basic colors are taken up by wool from a faintly alkaline or neutral bath, while the acid colors are left in solution. Thus if a dilute solution of the color be made faintly alkaline with ammonia and boiled with the wool, only- basic colors will be taken up. If both acid and basic dyes are present in the same solution, the basic color should first be exhausted by the use of fresh pieces of wool in the ammoniacal solution, till they no longer take out color, after which the solution should be made slightly acid with hydrochloric acid and again boiled with wool, which under these conditions takes out any acid colors. Comparatively few basic colors are employed in foods. Basic colors can be removed from the fiber by boiling with 5% acetic acid. Acid colors are removed therefrom by boiling with 5% ammonia. Having dissolved the dye from the fiber by the appropriate solvent as above, the decolorized fiber may be removed, and the solution evaporated to dryness on the water-bath. The residue consists chiefly of the dyestuff, and may be put through various reactions for identification according to Rota's scheme, page 799. Methods of Dyeing Wool from Food Products. — The wool employed should be white worsted, or strips of white cloth, such as nun's veiling or albatross cloth. Care should be taken that the color is pure white and not the more common cream white. The woolen material should be freed from grease by boiling first in very dilute spda solution and finally in water. Strips of the woolen cloth, or pieces of the worsted thus previously cleansed, are boiled in diluted filtered solutions of jams, jellies, ketchup, fruit and vegetable products, and similar food preparations, or 796 FOOD INSPECTION /IND ANALYSIS. in solutions of candy colors, or in wines, the clear solution of the sample to be tested being slightly acidified with hydrochloric acid. Arata * recommends boiling the wool in a dilute solution of the food material to which potassium bisulphate has been added, using lo cc. of a io% solution of the bisulphate to loo cc. of the solution to be tested. If the color solution is neutral, the wool should first be boiled in this before acidifying, to separate out any basic dyes. The dyed wool, after removal from the solution, is boiled first in water, and afterwards prefer- ably in an alkali-free soap solution. It is then washed and dried. The dried fiber may then be subjected to the various reactions given in the table, pp. 806-813; for recognition of the dye, this method of identifying colors by means of reactions on the dyed fiber being one of the most con- venient. Some of the vegetable dyes (including lichen colors) , also cochineal, dye wool directly, and these may be identified by reactions given in the table with the coal-tar dyes. Other vegetable colors, and the natural colors of fruits nearly always give a slight dull coloration or stain to the wool, but this is not, as a rule, to be mistaken for the vivid hues of the coal- tar dyes. Moreover most of the vegetable colors on the fiber turn green when treated with ammonia. Care should be taken to thoroughly wash the wool after the dyeing, so that colored particles simply held thereon mechanically may be removed. Sostegni and Carpentieri f recommend a method of double dyeing, applicable when acid dyes are employed. The method consists in first boiling the wool in a dilute acid solution of the food sample as above described, after which the fiber is removed and boiled, first in very dilute hydrochloric acid solution, and then in water, till free from acid. The color is then dissolved from the fiber by boiling the latter in a weak ammoniacal solution, some of the colors being more readily dissolved than others. The fiber is then removed from the solution, the latter is acidified with hydrochloric acid, and the color fixed on a fresh piece of wool by boiling therein. The second dyeing fixes coal- tar and Hchen colors on the fiber, but fruit colors and most others of vegetable origin remain in solution after this treatment. Any color left on the first fiber, after treatment with ammonia, is probably due to the * Ztsch. anal. Chem., 28 (1889), 639. t Ibid., 35 (1896), 397. ARTIFCIAL FOOD COLORS. 797 natural vegetable color of the sample, and is usually no more than a dull stain. Vegetable Colors on Wool. — In case no color is directly fixed on the fiber by boiling wool in a solution of the sample, either neutral or acid, absence of coal-tar colors may be assumed. In this case it is sometimes advisable to boil strips of previously mordanted white cotton in an acid solution of the sample, to remove certain vegetable colors for purposes of testing on the fiber. The cotton is mordanted by boiling in a dilute (5%) solution of potassium bichromate. Extraction of Colors from their Solution by Immiscible Solvents. — Methods based on this principle are in use in the municipal laboratory at Paris.* Sangle-Ferriere uses the following method: 50 cc. of the wine or solution to be tested for color are rendered slightly alkaline by ammonia, and cautiously shaken with about 15 cc. of amyl alcohol. If acid dyes are present, they will be dissolved, and will impart to the amyl alcohol a distinct color.f Basic dyes also are dissolved, but when they are present the amyl alcohol solution is colorless. Remove the amyl alcohol by means of a separatory funnel, wash with water, and finally, if the alcohol is colored, dilute with about an equal volume of distilled water and evaporate on the water-bath with a piece of white wool. The wool should be kept in the solution till the odor of the amyl alcohol has disappeared, and, if not then colored, for a short time longer, as with some colors the wool will dye more readily in the aqueous solution than in the amyl alcohol. Remove the wool, and evaporate the solution to dryness. Test for color in the dried residue, and on the fiber also. Orchil, like the acid colors, is extracted by, and imparts a coloration to the amyl alcohol under the above conditions, the color being a light violet. If the amyl alcohol extract after separation, washing, and filtering is colorless, acidify with acetic acid; if a basic color is present, it will be indicated by a coloration at this stage; if there is no coloration on the addition of acetic acid, no basic color is present excepting fuchsin, which is separately tested for. In case a basic dye is indicated, add dis- tilled water and evaporate with wool as before. Test the dried residue with pure concentrated sulphuric acid. * Girard, Analyse des Matieres Alimentaires, pp. 183, 681. t Acid fuchsin forms an exception to this rule by dissolving colorless like basic dyes. A special test is, however, given for it, p. 799. 798 FOOD INSPECTION AND ANALYSIS. Fuchsin is indicated by a yellow-brown color with sulphuric acid^ which by dilution with water becomes rose; sajranin, by a green color becoming first blue, then red, when diluted with water, and magdala red by a dark blue color, turning red on the addition of water. Basic colors are also extracted readily, according to Robin, by making the solution to be tested alkaline with sodium hydroxide, and shaking with acetic ether. The solvent is removed, washed, and evaporated with wool (on which the tests are to be made), or the evaporation is carried to dryness and the tests made on the residue. Many coal-tar colors are extracted by amyl alcohol in acid solution, but some of the natural fruit colors are also dissolved under these con- ditions. The coal-tar dyes thus dissolved will, however, dye wool and the fruit colors will not. Fruit colors are not extracted from acid or alkaline solution by ether, nor from alkaline solution by amyl alcohol. Robin's method for ascertaining whether acid colors are present consists in adding to the liquid to be tested an excess of calcined magnesia, and a little 20% mercuric acetate solution, the mixture being boiled and filtered. If the filtrate is colored, or if by the addition of acetic acid to the colorless filtrate a color is developed, a coal-tar dye is indicated. Separation of Acid and Basic Colors with Ether.* — Acid and basic colors may be separated from their dilute aqueous solution, according to Rota, by means of ether as follows: To 100 cc. of the solution add I cc. of 20% potassium hydroxide and shake in a separatory funnel with several portions of ether. Basic dyes are dissolved by the ether, leaving behind as a rule the acid colors. t Wash the ether extract with faintly alkaline water, and shake out with 5% acetic acid. Some colors remain in the ether, others are dissolved in the acid. Separate the two solvents, and evaporate each to dryness on the water-bath. The acid colors left in the slightly alkaline, aqueous solution after removal of the basic colors by ether as above, may, if desired, be separated into several groups by successive extraction, as follows: first slightly acidulate with acetic acid and extract with ether, then acidify with hydro- chloric acid and again extract, and finally examine the residual solution for colors that are insoluble in ether. Thus erythrosin and eosin are soluble in ether when shaken with their aqueous solution made acid with hydrochloric acid, while acid fuchsin is insoluble. * Analyst, 24, p. 45. t A few acid dyes are exceptional in being soluble in ether with alkeili, as for example^ quinolin yellow and the sudans. ARTIFICIAL FOOD COLORS. 799 Separation of Colors from Dried Food Residues by Solvents. — This method is rarely employed, excepting in the case of colors insoluble in water, but soluble in eher or alcohol. The dried pulp of canned veget- ables, ketchups, etc., may be acidified wi.h hydrochloric acid, and the color extracted therefrom direcdy wi.h alcohol. In this case however, there is no obvious advantage over the previous methods of dyeing the fiber directly in the acid solution of the sample. Girard's Tests for Acid Fuchsin.* — Add 2 cc. of 5% potassium hydroxide to 10 cc. of the wine or Other solution to be tested, or enough of the alkali to neutralize the acid. Then add 4 cc. of 10% acetate of mercury and filter. The filtrate should be alkaline and colorless. If the solution remains uncolored after acidifying with dilute sulphuric acid, no acid fuchsin is present. If, however, there is produced a red to violet coloration, and no other coal-tar colors have been found by the amyl alcohol extraction, the presence of acid fuchsin is shown. Bellier's Test for Acid Fuchsin. — Presence of acid fuchsin is indicated by adding to 20 cc. of wine or other solution to be tested about 4 grams of freshly precipitated yellow oxide of mercury, boiling and filtering. The fihrate, if acid fuchsin is present, is colored red, tinged with violet. According to Blarez, all red coal-tar colors, with the exception of acid fuchsin, and all red vegetable colors are completely decolorized by acidulating their aqueous solution with tartaric acid, and digesting with dioxide of Icad.f Schemes for Identification. — These serve for identifying unknown colors by their characteristic reactions, first grouping them into classes, and finally ascertaining the particular color itself. Of these may be mentioned the tabular schemes of Witt,t Weingartner,§ Green, |[ Mar- tinon,^ and Rota.** Rota's Scheme is one of the latest, and on some accounts the best, being based on the relation between the color and the composition of * Analyse der Substances Alimentaires, p. 185. t Allen, Commercial Org. Analysis, 4 Ed., Vol. V, p. 250. \ Zeits. anal. Chem., 1887, 26, p. 100; Analyst, 11, p. 115. § Jour. Soc. Dyers, etc., Ill, p. 67. II Jour. Soc. Chem. Ind., 12, No. i. ^ Jour. Soc. Dyers, 3, p. 124. ** Chem. Zeit., 1898, pp. 437-442; Anal., 24, p. 41, 8oo FOOD INSPECTION ^ND ANALYSIS. the dyes. The colors are divided into two main groups, according to whether or not they are reducible by stannous chloride. These two groups are each further subdivided into two classes, the reducible colors being classed according to whether the color remains unchanged, or is restored by treatment with ferric chloride, and the non-reducible colors according to their action with potassium hydroxide. The tests are carried out on a dilute aqueous or alcoholic solution of the coloring matter, the strength being about i in 10,000. Treat about 5 cc. of this solution with 4 or 5 drops of concentrated hydrochloric acid and about as much stannous chloride in a test-tube, shake the mix- ture, and heat if necessary to boiling. With some colors the process of decolorization is a slow one, especially if the solution is too concentrated, and it is well to repeat the experiment, if in doubt, diluting the original sample still further with water. Tin in solution in concentrated hydro- chloric acid may be employed instead of stannous chloride, if desired. Here, as in all cases of color testing, it is well to make comparative tests with known colors. CLASSIFICATION OF ORGANIC COLORING MATTERS. [A portion of the aqueous or alcoholic solution is treated with HCl and SnClj.] Complete decolorization. Reducible coloring matters. Colorless solution is treated with Fe_,Cle, or shaken with exposure to air. The color changed no further than with HCI alone. Nonreducible colors. A part of original solution is mixed with 20% KOH and warmed. The liquid remains unchanged. Color- ing matters not re- oxidizable. Class I. Nitro, nitroso, and azo colors, including oxyazo and hydrazo colors. Picric acid, naphthol yellow, ponceau, Bordeaux, and Congo red. The original color re- stored. Reoxidiz- able coloring mat- ters. Cl.\ss II. Indogenide and imido- quinone coloring matters, methylene blue, safranin, in- digo carmine. Decolorization, or a precipitate. Imido- carbo-quinone color- ing matters. Class III. Amido-derivatives of di and triphenyl methane, aura- mins, acridins, quinolins, and color derivatives of thio benzenil. Fuchsin, rosanilin, auramin. No preci p i t a t i o n. Liquid becomes more colored. Oxy- carbo-quinone col- oring matters. Class IV. Nonamide diphenyl methane, oxy-ke- tone, and most of natural organic col- oring matters. Eosins, aurin, aliz- •ft. ARTIFICIAL FOOD COLORS. 8oi .i ^ O^ c OJ a t^ rt < o >-i t; . ^ < <1 rs '—' o T) 3 1> a >. ri-l -0 M O "o O < CO U o o \/ *^ :^ I Ji-otS t/5 7 Pi ^ II ^ ^i.^^. ^i.S„.^i.^_: p2 . ^ II $ ^ II ^ cC g hS cfi 8- cP 8 H .. . . , . . H < c .. ' — — '■ — — • ' 9 U ^ iio.cD.c;^, giiS^ ^ 9 o| ^ « ^ o fcS6g>>fcS >.e^ c^Z g-SZ -^ "^ -^ 2 .s 2 ^o^e^Si ^^p |§ffi <§W U § y ^_: 3 S .c rf.S E 2 S^ a-^ ci.^ o • n "S- d u TJ O n3 , o ii n "r .s < .•c -<>o ^-^Ig^-^l^^d.^ I j^sSs ^^ S^'^a ^ hi O O c 9. ^' ^ bD ^ \\ ^ ^ r^ 'R 2 I 3- ^>c5-j::rt_,aj^o II ot;0-^ ' iv;- cr-S " So 2 FOOD INSPECTION AND ANALYSIS- fq 3 ^ ^ fC < s 3 rO > a t, 1 ••• O " .- P4 :z:-Rj a.s ^5 •jaqja HJiAi. papBi^xa puB HO"X ^}1^ p3;B3j; uot;nios DtioqoD|B jo snoanbB aijx 8o4 FOOD INSPECTION yiND yINyi LYSIS. < U Pi ^ S rt S O .0 o • § - ^- il / -\ II ^ M/ \y \8/ o m w < u w g B >< C ^ (^ w ^ Z- w w H •g O N V CU efl a < CO x^ \ O u \ / U — / fi^ II 1 Pi P^ V u— / '.J / -o a rt V "0 . O o c o 3 3 rr i.2 > c c« a.3 c-=; U U-^ ^ . 2 ^ c E o 5 ^ ;5 i a:^-^ -^ •" -^ 5 "^ ,t^ OJ o •- 3.!:| u .S-'o-O 0) O "3 C ii i^ 5 «s .r^ ii « xT w h mat U ethe fibe >» c T3 o ^ ^ o a ■ ■ ' ^ O^^-'O ^^v. d t;.g ii^ o -ke to gmatte f them in wa direct 1) r o (rt >.c o ji a . ^ c d K -c ^ ^ -^ 12 U 'o > gpq O s s ^ ^ u «j 4) 4^ «J 3 >; ? Ph c ^ 4 0>. -3 >. >. Is .2 c c ^- '> c i 2i rt o o^ o t E > >> ■w >^ cfl tfl tn y] -ii^-S ^ 1- t- O ::3 O ^^-ih^ U O Of ) pq Pk PM Ph w w O O o O o < O hH 1— ( H w «^ o> >>P3 4j csQ Q OQ '^ .S^ ^^ J- 'u 'o 'o 'u "o 'u 'o *o << -t3 t3 ■" S _ _ a> u -o -a t". tn 1* T3 t3 Td oj "O "O ^ ^ ^-a is ^ o o o & o o Cu CU CU O CL, Q. c d d c c ^T3 o o o <4 o o u I-. k. 0^ ii u, m pq pq pq pq 1) t3 fe V OJ ||1 P C >- c 52 o ^ ^ a, o -o pq PQ Pi; pqc« "^pq ^S-dMSmm^5 m^Mi^ppwu p5 en en c3 < C pq O 3 en J^ -O _ 0) -C T; 05 -o 13 bC "1 3 i^'S 3 '^ o d .S o 6 ' ^ O ^ rt CrtW U Oj OJ tfl ocSt;o^"S_gaJj.Sg -S 'S S "C '^ a 2 f 'S c .-3 -S C?u'^.= s30nOi-.'-^30 WO «pL,UJ I JT* 'r* T" ■*-' *rH ^ r! 'r* "r* J _0 _ o o "o ^ "o ^ QQ QQ .S -5 op o^ o x; h-li-l >* > & ^ ^ T3^ ^i^ 1.^ [Hi as i2 >> " ''PQ = Q 3 P >^ P3pq m -2 - S^ ^ ^ >> Ph ^ P-i Ph Pi iz::^; puPh b. P O o ^^;s uu ffi P5 & 5: .s I .SPSS o P^ PhPQ ^ ^ 3 2P -c ii ii >>o oi 3 CPU i 2 s PQ m;^ 3 .2 BO «J o Q cii 3. o. .a O >-) o U a w Pi rt • C M g ^ .- < M_, .S o 11 UPh S cs "' Q. O Vi o O n £r 2 ^!i wo m fc G < oa 3 - V -- PL, o t^c .2 .2 g ? N m -a o P^Q M' .2 « > > u W H o t/; O o U O o < c Sp^ K O p< d Ai <; d d M o o d tn cj s S-S u ^^ Tl -T3 u u < < 1-. 5j O ju -o e< ^ PQ << .ii "O -d T3 =^ !5 '^ '^ CQ < < < Ph •d 13 fe. OJ o O c o S o ^ d o XI -red woe -red woe -red po\ der pinkisl- Dark Dark Fiery Drv o o d d 2 •d >. o aj !« oj a, O aj rt i; & -9 o > -d bxJ o d 1; >-. -d o s a, aj o tfo >hC C >H o pq U (U tJ a> w O . o < Z S < O ■' u s ^ _ ^ - ^ WW u u ^ .C/3 S aj _: P o ^ d3 &c o 0:^0 ^ p d ws-^s & >■ IS > o J-' - z? jTi; .s =« .2 :S - ^ ^ X ^ -5 p,> 'iz, Z U dO >,:2 bco'bo^sr-^ o ^ u d ,1- c >- d ki; iH ^< gh 2H 2'^H fe o o o ARTIFICIAL FOOD COLORS. 809 o ggg ^=2 2 -s ^ 'B< ^ c ^ d O r- r* ■ — ■ *-^ N .u; .;:. -C 1; 1-. K> >^o u ^ Q ^ ^ o Q Q Q >. >. a> o C O ch o rt 5 .2 o U 0) 4-> HJ , a. 1-1 .5 iH 3 fin Pi V O II 5l (1 li O O p"" 3Rg fey" ^ c a OJ 0) d) 5^ O o .2 o > o U Pm> ^ a, «Ph >. >H -3 U ^ Q Q o o 2 « O -£! h5 -^ -fi C -S ^ ^ >^> *^ ( J f *-• ^ cd O 3 Q !z; < O o hj 1-1 w & 7i d tn -a C5J t-l u n 03 c ^ •d ( ) Is A.> ^ § ^ = ^ >^P o >.^H^^ _ OH O t-l O I— I _ O 8i" «' a 2 ^ = 8io FOOD INSPECTION /IND /tNALYSIS. o o ^^ ^ W pq tj ^ rt > .2 o > m 60 pq c S ^ c c ij c ^ s o & ^ >'^ m P >H m m -g.^ u ^ (-S ""• O O o O > PQ P^ ^ Q -T1 -Tl nj :=5 ;= ; > > o >^ O 'O p^ °. -c fi ^ C c rt (fl r« ^ o o o o zz d .2 -Sis p^ (U o O ^ ^ U >H >H >H Ph pqpq pq t^ ^^ ^ iC t, > II p:i "-1 f ^^ O oj tn^ 3 P ^ti: ^ & ^ fe ^ ^ ^ g ^ o „ B 8 CO g fc tn 1) !- ^ o g > pq :5 & 1 ^ ^ >H pq pqpq ■^pq c •^ < S Os o w J o Hi 1-1 w o O 6 >'o ° (U 0,::= tuD O 3 Shi O Ph P3 O ni * 2^ £ u < C O •n c ^ ^ S Pi .5 6 o U .s o u a; (L) h I j; 3 " ™ H ^ c c c c c c ^ is: ^ o o o o o o _o o u u o o u o i" u o cfl cS C3 rt 03 rt JX >4 O o o o o Z2;2:zz:^ n , o .5 o'2 C O PP t3 "O o ^ m .2 C.N c ^.2 c c c P P^ ^Z Tl u (U bO N C •c c« o 4J o O OJ IZW S ^ C „.^ 0.2 c ^P^ O "0 (LI m s: ^ - lu aj - S 60 bc 5 c .2 c ^ <= ° 1^ ^ X ^ n! ^r- rt P rt .„ u i_ C .2 15 ^.SP ^ ^^z z 5 oj TO ^ .op o o i c ^ ^ c ^ & & _o _0 CQ >< >i in • ^^PhS OU - t:; C C ,'-' v2 ?P„ ni g p ti W) , .2 ^ ^H .2 a s^ U ^^ 2 Q ^ ^ '^ oi cfi •u .52 '^ 8l2 FOOD INSPECTION AND ANALYSIS. Om 5 O rt loriz reen own (J .> C yoM O O Q I Pi w I— ( p^ H w h '^ O O ♦-) o u p^ o o (—1 IS u >- T3 >^ >^ o =* o O .N .N > 'Zi 'u 'C o O o o — O U U >( ^ QQ >* O Mo c/l O O 5 i^ > ^ I' -Si o o !> &. O C (J S ' 'm cSI |p^- 3 XI o a, o -5 c en 3 1-, OJ o o 2| ^ OJ .^ !* 2o rt O txiTj iota -^ o i2 o Q Q u m ^ O CI 5 ^ o o .5P5 <• HH I— ( J-H Ph -^.2 g ^^ J. b s^ e rt u 5 2 ■£ 9 bC >-. O C .*i P> bC O -g ^ &| oj OJ OJ -5 •^^^^ ^ ARTIFICML FOOD COLORS. 813 C 1) t;-2:o > . O t3 4:3 : & .2 ;_o c ■ :>^ : O 1) 51 ^1 ;2; C.2 « S-S m o>Q o s ^'z. PQ S Q ■ +- ■H !•* c ii : 60 > ■o S h "> •7" V.U.2 g> I I I I I nQuSn 8 14 FOOD INSPECTION AND ANALYSIS. Reagents. — In ajiplying tests on the fiber, the reagents commonly used) are as follows: Concentrated hydrochloric acid, concentrated sulphuric acid, sodium hydroxide (io% solution), strong ammonia (28%), a hydro- chloric acid solution of stannous chloride, and concentrated nitric acid.. The tests should be made on pieces of the fiber in small porcelain evapo- rating-dishes, which more readily than test-tubes show exact shades of color. In cases of suspected fluorescence, test-tubes should be used. Nitric acid is conveniently applied by a glass rod to the fiber. The stannous chloride should first be allowed to act in the cold. If no change occurs, gentle heat should then be applied, and finally boiling. Separation and Identification of Allowed Colors. — Price Method.'^ — The procedure is according to the analytical scheme given on page 815, As a preliminary test the powdered material is scattered upon water, alcohol, and sulphuric acid, noting whether one or more colors are present. Quantitative Separation of Acid Coal-tar Colors. — Mathcwson Method.'^ — This process, like the preceding, is for the colors themselves, but may be adapted for the detection of the colors in food products after separation by means of solvents or less satisfactorily by dyeing. Mathew- son's table is given on pages 816 and 817. In applying the data given in the table proceed essentially as follows:. Treat the solution containing 0.2 to 0.4 gram of color (depending on the nature of the dyes) with sufficient water and hydrochloric acid to bring: its volume to about 50 cc. and its acid concentration to that point for which the difference in percentage of color extracted for the two dyes is near its maximum. Shake the solution with the immiscible solvent, passing it in succession through three or four separatory funnels each containing 50 cc. of the latter. Wash the portions of the solvent with 50 cc. of hydrochloric acid of the same normality as the solution, passing it successively through the separatory funnels in the same order as was the original solution, and repeat this operation with one or two fresh amounts of the hydrochloric acid. The dye relatively more soluble in water is determined in the combined washings and extracted solution. Remove the second dye from the solvent by shaking with water, very dilute caustic soda, or, more quickly, with dilute caustic soda after the addition of some gasoline, or similar substance in which the color is insoluble. * U. S. Qei^t. of Agric, Bur. of An. Ind., Circ. 180. t U. S. t>^pi. of Agric, Bur. of Chem., Circ. 89. ARTIFICIAL FOOD COLORS. 815 >< OJ (U rt fi ^ X 4J t» V-i n a rt J3 c 3 « ^1 ^.^- •0 CI C 3 W * ^ >* n! Z ^ o>5 ■c " - -a . m oj ^ m 3 Ct3 C rt a; p 0) „ g -g ni-d o- °r-^ ^ tiJ "ir^ " 3 « f»>j;:;: ^; (U « • •- t« '^ 3 p^ >^^ ft D-a u'o J, ■3 ^ 1) C 0) c ftdl OJ ' ji'S^^'^-ioWij:: "; o -a j=" ft o M Cj: (U o - X c M 0) > n1 C c 0) d c ai a 3 -, 0) d ^ M J- O t;:Sj-d rt°-S'^ t,.a"« Zis S-;st^-o o<; m rt &i3 a" 0;=| 3'>H ol tS &2 S.Sq g^2>2 • WO) - W 'O ii> op . '^ C ^ o, -■si o ° Sr^u^ ■^ C t- r- o & &:5Q oi c .c a « .a .^ c • ■M M 5 o-d 9. o o'Xi o o^ eon 3 O S ^ 1 u, 3 C (U o *J O 1- 0) <-■ — ' ^ SE .Cog .w ■> "- •3 p «> "J ft u ■5 '^ C >« cij '^ ti m bO "^ o aJ ^ X .0 "3 S S S o .S "rt O . 5 >. g " 'Si S rt o nl '- "^ ™ ^ M w •" .r fO c 1 i >^ 5 -S "o J 6 S i« " £ ci5 " * '3 t- h, 8i6 FOOD INSPECTION AND ANALYSIS. The following table by Mathewson * shows the percentage of color in the water solution after shaking with an equal volume of immiscible solvent. MATHEWSON'S TABLE SHOWING PERCENTAGE OF COLOR IN THE WATER SOLUTION AFTER SHAKING WITH AN EQUAL VOLUME OF IMMISCIBLE SOLVENT. solvent: amyl alcohol. Colors. Naphthol Yellow S No. 4 . . , Orange I No. 85 Ponceau 3 R No. 56 Amaranth No. 107 Light Green S F No. 435 . . . Erythrosin No. 517 Indigo Carmin No. 692 ... . Fast Yellow No. 8 Crocein Orange G No. 13 . . Orange G No. 14 Ponceau 2 R No. 55 Crystal Ponceau No. 64 . . . Fast Red B No. 65 Resorcin Yellow No. 84 ... , Orange II No. 86 Brilliant Yellow S No. 89 . . Tartrazin No. 94 Metanil Yellow No. 95 ... . Fast Red A No. 102 Fast Red C No. 103 Fast Red E No. 105 New Coccin No. 106 Scarlet 6 R No. 108. .... .. Resorcin Brown No. 137 . . . Cotton Scarlet 3 B No. 146 . Congo Red No. 240 * Azo Blue No, 287 f Chrysophenin No. 329 Guinea Green B No. 433. . . Acid Magenta No. 462 ... . Normality of Hydrochloric Acid in Water Layer before Shaking 2 h 1 i \ 16 Percentage of Color in Water Solution after Shaking. 5 90 34 36 41 75 IS 95 51 15 80 3 52 97 61 73 47 95 48 93 7 82 99 96 14 II OS 93 99 99 58 8 16 5 90 4 17 75 32 17 43 27 64 39 62 68 20 10 25 43 4 78 17 3 * Color acid nearly insoluble in both layers. t Similar to Congo Red but color acid more soluble in alcohol. * U. S. Dept. of Agric, Bur. of Chem., Circ. ylRTIFIClAL FOOD COLORS. 817 MATHEWSON'S TABLE SHOWING PERCENTAGE OF COLOR IN THE WATER SOLUTION AFTER SHAKING WITH AN EQUAL VOLUME OF IMMISCIBLE SOl^VE^T— {Continued). solvent: dichlorhydrin. Colors. Normality of Hydrochloric Acid in Water Layer before ^Shaking. Percentage of Color in Water Solution after Shaking. Naphthol Yellow S No. 4 . Ponceau 3 R No. 56 Orange I No. 85 Amaranth No. 107 Light Green S F No. 435 . Indigo Carmin No. 692. . . Acid Magenta No. 462 .. . 15 37 4 95 15 91 86 17 Naphthol Yellow S No. 4 . Ponceau 3 R No. 56 . . . . solvent: amyl acetate. 95 3,i 96 97 Naphthol Yellow S No. 4 . Orange I No. 86 solvent: ether. 94 97 97 97 Assuming the distribution ratios to remain constant, this procedure using four funnels and making three washings gives for a pair of colors whose " distribution numbers " (as the percentage numbers given in the table may be called) are 80 and 20, respectively, a separation of 98.30 per cent for each color. With distribution numbers 90 and 10 four funnels and three washings give a calculated separation of 99.73%, and the same is obtained with distribution numbers 81.8 and 5.3 if the solvent in which the dyes are relatively more soluble be taken in portions one-half the volume of those of the other liquid. If the second, third, and fourth funnels be given a fifth washing, the third and fourth funnels a sixth, and the last funnel a seventh washing, the calculated loss for the color more soluble in the solvent layer is 0.76%, while the percentage of the other dye removed is relatively much increased (to 99.99 per cent). In most mixtures the progress of the separation is always apparent. ^8l8 FOOD INSPECTION AND ANALYSIS. In practice, because of incomplete extraction and separation, and especially on account of uncertainty due to small amounts of subsidiary dyes always present, it is necessary to increase the number of successive extractions. The formation of esters of the color acids is a possible source of difficulty, but is not believed to take place. With amyl alcohol as solvent it is usually desirable to make the original solution more strongly acid than is indicated by the distribution data and use relatively more portions of the washing liquid. Of the permitted colors, Naphthol Yellow S is best separated from Orange I by washing the amyl alcohol solution of the color acids with strong salt solution, care being taken that not too much color is present. With a solution containing 20 grams of salt and 0.04 gram Naphthol Yellow S per 100 cc. and shaken with an equal volume amyl alcohol, 97% of the color is retained by the water. With a similar solution contain- ing 0.07 gram Orange I, the water layer contains 1.5% of the total color. With higher concentrations some color may be salted out in solid form, but this does not interfere if the amount is small. Erythrosin being quantitatively removed from slightly acid solutions by amyl acetate, ether, or amyl alcohol, its separation from sulphonated colors presents no difficulty. Analysis of Food Colors. — Seeker and his co-workers have devised methodsj for the analysis of the seven coal-tar colors allowed by federal decision in the United States. The methods are for the detemination of the ultimate constituents and for impurities, including arsenic and other heavy metals. The reader is referred to Hesse 's report (see reference, page 819) for details of these processes. Solubility Tables. — Robin* has pubhshed tables showing the reactions of the coal-tar dyes used in confectionery, classified as basic, acid, and water-insoluble colors, the distinction of basic and acid colors being based on their extraction by amyl alcohol or ethyl acetate from alkaline and acid solutions. Rota (page 798) employs ether for the separation of basic colors. Loomis (see reference, page 819) has prepared a table giving the solubility of food colors in various solvents, including those named above, and another table showing the relative amounts extracted from neutral, alkaline, and acid solutions, shaking with amyl alcohol, ethyl acetate and acetone, the aqueous solution in the latter case being saturated with salt. * Girard: Analyse des Matieres alimentaires, 2 Ed., pp. 679-691. ARTIFICIAL FOOD COLORS. 819 REFERENCES ON COLORS. J\rata, p. N. (Specielle analytische Methoden.) Zeits. anal. Chem., 28, p. 639. Bellier, J. Detection of Artificial Coloring Matters in Wine. Ann. de Chim. Anal., 5, 1900, p. 407; Abs. Analyst, 26, 1901, p. 42. Benedikt, R., and Knecht, E. The Chemistry of the Coal-tar Colours. London, 1889. Berry, W. G. Coloring Matters for Foodstuffs and Methods for their Detection. U. S. Dept. of Agric, Bur. of Chem., Circular No. 25. Dommergue, G. Detection of Colors on Dyed Wool. Monit. Scient., 33, p. 25; Abs. Jour. Soc. Chem. Ind., 8, p. 216. FOL, F. Testing of Dyestuffs. Jour. Chem. Soc, 28, 1875, p. 193. Green, A. G. On the Qualitative Analysis of Coal Tar Colbring Matters. Jour. Soc. Chem. Ind., 12, 1893, p. 3. Hesse, B. C. Coal Tar Colors Used in Food Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 1-37, 191 2. Leeds, A, R. Tabellarische Uebersicht der kiinstlichen organischen Farbstoffe. Berlin, 1894. LooMis, H. M. Report on Colors: The Solubility and Extraction of Colors and the Color Reactions of Dyed Fiber and of Aqueous and Sulphuric-Acid So- lutions. U. S. Dept. of Agric, Bur. of Chem., Circulars Nos. 35 and 63. Martinon, B. Jour. Soc. Dyers, 3, p. 174. MiLLiKEN, S. p. Identification of Pure Organic Compounds. Vol. III. Com- mercial Dyestuffs. New York, 1910. NiETZKi, R. Chemie der organischen Farbstoffe. Berlin, 1901. PosETTO, G. Composition of Vegetable Coloring Matters for Use in Confectionery. Zeits. Nahr. Unters. u. Hygiene, 9, 1895, p. 150. Rawson, C, Knecht, E., and Lowenthal, R. A Manual of Dyeing. London, 1893. Rawson, Gardner, and Laycock. A Dictionary of Dyes, Mordants, etc. 1890. Reichelmann and Leuscher. Detection of Coal Tar Colors in Pastry, Cakes, Fruit Products, etc. Zeit. fiir offentl. Chem., 8. 1902, p, 204; Abs. Analyst, 27, 1902, p. 276. Rota. A. R. A Method of Analyzing Natural and Artificial Organic Coloring Matters Analyst, 24, 1899, p. 41. From Chem. Zeit., 1898, p. 437. ScHULTz, G., u. Julius, P. Taballarische Uebersicht der kunstlichen organischen Farbstoffe. 1897. Translated by Green, A. G. A Systematic Survey of the Organic Coloring Matters, ist ed., 1894; 2d ed., 1904. Seeker, A. F. Coloring Matters in Foods. Allen's Commercial Organic Analysis. 4th Ed.; Vol. V, p. 625. SosTEGNi, L., and Carpentieri, F. (Specielle analytische Methoden.) Zeits. anal. Chem., 35, 1896, p. 397. Spaeth, E. Foreign Coloring Matters in Fruit Juices. Zeits. Unters. Nahr. Genuss., 2, 189Q, p. 633. TOLMAN, L. M. Coloring Matter in Food. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. III. V. S. Food Inspection Decisions: No. 76. Dyes, Chemicals and Preservatives in 820 FOOD INSPECTION /iND ANALYSIS. Foods. No. 77. Certificate and Control of Dyes Permissible for Use in Color- ing Foods and Foodstuffs. No. 106. Amendment to No. 77. No. 117. The Use of Certified Colors. No. 129. Amendment to No. 77. Weber, H. A. Effect of Coal Tar Colors on Digestion. Am. Chem. Jour., 8, 1896, p. 1092. Weingartner. Eine Anleitung zur Untersuchung der im Handel vorkommenden kiinstlichen Farbstoffe. Zeits. anal. Chem., 27, 1888, p. 232. Weyl, T. Translated by Leffmann, H. The Sanitary Relations of the Coal Tar Colors. Philadelphia, 1892. WiNTON, A. I.. The Use of Coal Tar Dyes in Food. Conn. Agric. Exp. Sta. Rep., 1901, p. 179. Witt, O. N. Versuch. einer qualitativen Analyse der im Handel vorkommenden Farbstoffe. Zeits. anal. Chem., 26, 1887, p. 100. CHAPTER XVIII. FOOD PRESERVATIVES. Preservation of Food. — Various processes have from ancient times been known and used for arresting the fermentative changes which food products in their natural state undergo on long standing. These proc- esses include pickling with vinegar, drying, smoking, salting, preserving with sugar, and finally in the employment of heat in sterihzing and pas- teurizing, and of low temperature as in cold storage. All of them are still in use, and are universally regarded as unobjectionable. In addi- tion to these old and well-known methods of food preservation is the comparatively modern practice of arresting fermentation by the use of such antiseptic chemical agents as formaldehyde, beta-naphthol, boric, salicylic, benzoic, and sulphurous acids or salts of these acids, etc., in regard to the wholesomeness of which there is considerable difference of opinion. These substances depend for their efficiency on the more or less complete inhibition of bacterial growth. Nearly all exert a power- ful antiseptic influence, to such an extent that to accomplish their object only small quantities need be used in food. Apart from their toxic effects, a marked difference naturally exists between the employment of such substances as salt, sugar, and vinegar for food preservation, all of which are in themselves foods, and in the use of chemical agents that have no food value. The advocates of the use of chemical antiseptics claim that there are no authentic instances on record of injury from the use of such small quantities of these sub- stances as are necessary to arrest decay, while there are many cases of injury arising from the use of foods which, while apparently wholesome, have undergone such fermentation as to develop ptomaines or other harmful toxins, and that because antiseptics prevent such spoiling of the food, their use is decidedly beneficial; that there is, besides, no more reason why a prejudice should exist against the employment of these 821 822 FOOD INSPECTION AND ANALYSIS. newer chemicals than against saltpeter, which has long been used in the corning of meat, or against the cresols and phenols left as a product of smoking. The opponents to their use assert, that the addition to food of such antiseptic substances as prevent its decay also serves to retard the dio^estive processes when the food is eaten; that many of these substances are drugs, and as such cannot fail even in small quantities to exercise a toxic effect of some sort on the system; that finally their use is objectionable, as allowing the employment in certain foods of old materials that have in some cases already undergone incipient decomposition before the addition of the antiseptic, and are thus un- wholesome. Regulation of Antiseptics in Food. — In the absence of legislation directly prohibiting the use of any of the above-named antiseptics, and in view of the difference of opinion regarding their toxic effects when present in small quantities, it is difficult to maintain a complaint under the general food laws as they exist in most states, basing the complaint solely on their harmfulness. In some localities certain antiseptics are specifically allowed and others are prohibited. Some of the states, as, for example, Massachusetts, have special laws under which it is required that in the case of all foods thus treated, the name and percentage of such antiseptics as are used must appear plainly on labels of the packages or containers thereof, such a provision being based on the assumption that the general public should be informed of what they are buying, where any doubt exists as to the wholesomeness o£ any ingredient present. Where such laws as these are in force, the chemist's task is compara- tively easy, in that conviction in court is not dependent on his individual opinion regarding the toxic effects of the antiseptic employed. Physiological experiments for testing the toxicity of these chemical preservatives were formerly confined to the lower animals, but no satisfactory results could be thus obtained. Later, metabolism experi- ments were made on human beings treated with varying amounts of the preservatives under carefully controlled conditions, but the resuhs of these, though made by experts of unquestioned abihty, do not agree. Even if any of these substances as used in food appear to have little or no effect on people in good health, they cannot be assumed to be equally harmless to those who are inclined to be delicate or sickly. Even though pronounced harmless in themselves, there is still the objection that the chemical preservatives may readily conceal unclean methods or materials. If perishable foods are free from preservatives and are sweet and FOOD PRESERVATIVES. 823 untainted, the consumer has reason to beheve that clean and whole- some materials and sanitary processes were employed throughout in their manufacture. Commercial Food Preservatives. — A large number of commercial preparations are sold for purposes of preserving specific articles of food and are put out under trade names that usually convey no suggestion of their true character. Some of these consist of a single antiseptic sub- stance, such as salicylic acid, ammonium fluoride, calcium sulphate, borax, or benzoic acid, while others are mixtures of several antiseptics, of which the following are typical examples, showing their composition as found, together with the amount of the mixture to be employed. A. For preserving sausage meat, using 8 ounces per 100 pounds cf meat: . Borax 36% Sah 46% Saltpeter 18% (Colored with an anilin dye.) B. For preserving cider and ketchup. A 34% solution of beta-naphthol in alcohol, using 2 fluid ounces to 45 gallons of cider, or i^ ounces to 10 gallons of ketchup. C. For preserving beer, using i^ ounces per barrel of beer: Salt 45% Salicylic acid 27% Sodium carbonate and salicylate 28% D. Fcr preserving chopped meals, using i ounce to 50 pounds o£ meat* Sodium sulphite 65% Borax 35% E. Effective for curing beef, hams, tongues, bacon, pig's feet, etc.: Borax 28% Boric acid 12% Sodium chloride 35% Potassium nitrate 25% F. For preserving milk and cream: Boric acid 75% Borax 25% 824 FOOD INSPECTION AND ANALYSIS. G. For preserving jellies, jams, preserves, mince-meat, and syrups, using from i to 2 ounces of preservative to 100 pounds of product: Sodium benzoate 50% Boric acid 40% Sodium chloride 5% Sodium bicarbonate 5% H. For preserving ketchup and tomato pulp, using from 6 to 8 ounces to 45 gallons of the product : Sodium benzoate 50% Sodium chloride 40% Sodium sulphite 10% /. Effective for keeping butter from becoming tainted or rancid, also for salt codfish, using 8 to 12 ounces per 100 pounds butter: Boric acid 25% Borax 50% Sodium chloride 25% /. For preserving eggs (surface appl'.cation). A saturated solu- tion of salicylic acid in 3 quarts of water, i quart strong alcohol and 7 ounces of glycerin. FORMALDEHYDE. Formaldehyde (HCHO) is a gas formed by the action of a red-hot spiral of platinum wire on vaporized methyl alcohol. It is also pro- duced by the dr}' distillation of calcium formate. In the market it com- monly appears in the form of a 40% solution of the gas in water under the name of formalin, and for use as a food preservative dilute solutions of from 2 to 5 per cent strength are usually employed. Its use as a food preservative is comparatively modern. Formaldehyde, while not con- fined exclusively to milk products, is, as a matter of fact, more com- monly used in these than in other foods. Its prompt and direct action in checking or preventing the growth of lactic acid bacteria renders it especially desirable for use as a milk and cream preservative, from the standpoint of the dair}' man who does not concern himself as to whether or not its use is injurious or illegal. When present in milk to the extent of i part formaldehyde to 20,000 parts milk (a proportion quite commonly employed), the sample is kept FOOD PRESERyATlVES. 825 sweet for four days in summer weather, when under ordinary conditions, the milk untreated would curdle in less than forty-eight hours. Determination of Formaldehyde in the Commercial Preservative. — (i) lodometric Method."^ — Mix 10 cc. of the aldehyde solution (diluted if necessary to a strength not exceeding 3% of formaldehyde) with 25 cc. of tenth-normal iodine solution, and add drop by drop a solution of sodium hydroxide, till the color of the liquid becomes clear yellow. The solution is set aside for at least ten minutes, after which hydrochloric acid is added to set free the uncombined iodine, and the latter is titrated back with tenth-normal thiosulphate. Two atoms of iodine are equivalent to one molecule of formaldehyde, in accordance with the following reactions: 6NaOH+6I =NaI03+5NaI+3H,0. aCH^O-fNalOg =3CH,0,+ NaI. 5NaI + NaI03+ 6HC1 = 6NaCl+ I^-f 3H,0. (2) Method 0} Blank and Finkenheiner,-\ — Three grams of the solu- tion are weighed into a tall Erlenmeyer flask, to which is then added from 25 to 30 cc. of twice-normal sodium hydroxide. 50 cc. of pure 2.5 to 3 per cent hydrogen peroxide solution are next gradually run in during a space of from three to ten minutes, through a funnel placed in the neck of the flask to prevent spurting, and the solution is allowed to stand for two or three minutes, after which the funnel is washed with water. Finally the unused sodium hydroxide is titrated with twice-normal sulphuric acid, using litmus as an indicator. The less formaldehyde in the sample, the longer the mixture should stand after addition of the hydrogen peroxide, to complete the reaction. When less than 30% is present, it should stand at least ten minutes. Ascertain the percentage of formaldehyde, by multiplying by 2 the number of cubic centimeters of soda solution used, when 3 grams of the sample are taken. (3) Ammonia Method. I — Weigh 10 grams of the formaldehyde solu- tion into a flask, and treat with an excess of ammonia. Cork the flask and shake frequently during several days. The formaldehyde is by this process converted into hexamethylamine. Transfer the solution to a tared platinum dish, and evaporate nearly * Zeits. anal. Chem., 1897, 36, pp. 18-24; abs. Analyst, 22, p. 221. t Ber., 31 (17), 2979. J Conn. Exp.Sta., Annual Report, 1899, p. 143. 826 FOOD INSPECTION /IND /1NALYSIS. to dryness on the top of a closed water-bath. Finally the dish is trans- ferred to a desiccator, and the drying continued over sulphuric acid, to constant weight. The per cent of formaldehyde is calculated from the weight of the hexamethylamine, making a correction for the residue left by the formaldehyde itself by direct evaporation : 6CH20 + 4NH,OH = (CH3)eN,+ loH^O. Or an excess of a standardized ammonia solution may be added in the first place, the excess of ammonia being distilled off and titrated with standard acid, calculating the per cent of formaldehyde by the amount of ammonia absorbed. Detection of Formaldehyde. — Methods have previously been given for the detection of formaldehyde in milk. Pure milk furnishes a con- venient reagent for the detection of formaldehyde in various preparations. A solution of the sample to be tested is acidified with phosphoric acid, subjected to distillation, and the first few cubic centimeters of the dis- tillate are tested for formaldehyde as follows: (i) Hydrochloric Acid and Ferric Chloride Test. — Add a few drops, of the suspected distillate to about 10 cc. of pure milk (previously proved free from formaldehyde) in a porcelain casserole, and carr}^ out the test as described on page 180. (2) Hehner^s Sulphuric Acid Test. — Apply the test as described on. page 180 to 10 cc. of pure milk to which a few drops of the suspected distillate have been added. (3) Resorcin or Carbolic Acid Test. — To about 10 cc. of the distillate to be tested, add a few drops of a 1% solution of carbolic acid or resorcin, mix thor6ughly, and carefully pour the liquid down the side of a test-tube containing concentrated sulphuric acid. In the presence of formaldehyde, a rose-red zone is formed at the junction of the two liquids, sensitive to I part in 200,000. If formaldehyde be present to an extent exceeding I part in 100,000, a white turbidity or precipitate is formed above the colored zone. (4) Phenylhydrazine Hydrochloride Test.* — One gram of phenyl- hydrazine hydrochloride and i^ grams sodium acetate are dissolved in 10 cc. of water. Add 2 to 4 drops of this reagent, and an equal arnount of sulphuric acid, to i or 2 cc. of the distillate to be tested in a test-tube. A green coloration is produced in the presence of formaldehyde. * Jour. Am. Chem. Soc., 22, p. 135. FOOD PRESERyATIVES. 2,2J- If present in a very small amount (say i part formaldehyde in 200,000),. heat is necessar}^ to bring out the color. Determination of Formaldehyde. — The exact quantitative determina- tion of formaldehyde in food products is difficult, owing to its extreme volatility as well as the uncertainty of the compounds which it forms with proteins. A rough idea of the amount present may often be gained by the intensity of the colorations produced in carrying out the various qualitative tests. Formaldehyde in the small amount present in food products may be roughly determined by the potassium cyanide method (p. 181), on separate portions of the distillate of about 20 cc. each, collecting the distillate as long as an appreciable amount of formaldehyde is showoi therein. BORIC ACID. Boric or boracic acid is commonly obtained in impure form from lagoons or fumaroles of volcanic origin in Tuscany. It is afterwards purified by recrystallization. It is weakly acid, and readily soluble in water and in alcohol. Its alcoholic solution, even when the acid is present , in small quantity, burns with a characteristic green flame. The acid- is quite volatile with steam. Borax, the most commonly known salt of boric acid, is found native- in Italy, California, and elsewhere, and is also made from boric acid- It is mildly alkaline, and readily soluble in water. Boric acid and borax, either used separately or mixed, have long been used as preservatives, especially in animal foods. A mixture of 3 parts boric acid and i part borax has been found very effective as a milk and butter preservative, as well as for meat products. Determination of Boric Anhydride in Commercial Preservatives. — Gladding Method,'^ — A 150-cc. flask, Fig. 117, is arranged with a doubly perforated stopper having two tubes, one of which, the inlet-tube reach- ing nearly to the bottom, connects it with a larger flask, while the other or outlet-tube communicates with a Liebig condenser, which in turn delivers into a receiving-flask. In the 150-cc. flask, i gram of the powdered sample is placed, vwth about 20 cc. of 95% methyl alcohol and 5 cc. of 85% phosphoric acid. The larger flask is then filled two-thirds full of methyl alcohol, and heated on the water-bath after the apparatus has been connected up. Heat is also applied to the 150-cc. flask, the * Jour. Am. Chem. Soc, 20, 1898, p. 288. 828 FOOD INSPECTION AND ANALYSIS. whole arrangement being such that a continuous current of methyl alcohol vapor bubbles through the liquid in the smaller flask, the heat being so regulated that from 15 to 25 cc. of methyl alcohol remains in the 150- cc. flask, while about 100 cc. of distillate passes into the receiving-flask in half an hour. Continue the distillation till all the acid has passed over, which is usually accomplished by distilling 100 cc. By a gentle aspiration upon the receiving-flask, loss by leaking may be avoided. Fig. 117. — Apparatus for Determining Boric Acid According to Gladding. Prepare a mixture of 40 cc, of glycerin and 100 cc. of water, and care- fully neutralize, using phenolphthalein as an indicator. Add this mixture to the distillate, and titrate the whole with tenth-normal sodium hydroxide. Run a blank with the reagents alone, deducting any acidity. For the fac- tors for calculation see page 830. Detection of Boric Acid and Borates. — These are best tested for in most cases in a solution of the ash of the sample, the quantity to be used for the test depending largely on the case in hand. With meat products and canned goods, about 25 grams are taken for the test, being first made distinctly alkaline with lime water, dried over the water-bath, and burned. The ash is boiled with from 10 to 15 cc. of water, and tests made on the solution. With such products as salt codfish, which is preserved by brushing or coating with boric mixture, portions of the coating may be scraped off and boiled in water, the tests being made on the aqueous solutions. FOOD PRESERyATIl^ES. 829 (i) The Turmeric-paper TeJ. — The most delicate test for boric acid, Tree or combined, is made by the aid of turmeric-paper, prepared by soak- ing a smooth, thin grade of filter-paper in an alcoholic tincture of pow- dered turmeric. The paper is afterwards dried and cut into strips, which are kept for convenience in a wide-mouthed bottle in a dark place. Slightly acidulate the ash of the sample to be tested with a few drops of dilute hydrochloric acid, avoiding an excess of acid. Then dissolve the ash in a few drops of water and thoroughly saturate a strip of the tur- meric-paper in the solution. On drjdng the paper, if boric acid either free or combined be present, a cherry-red coloration will be imparted to the paper, the depth of color depending on the amount present. As a con- firmator}' test, apply a drop of dilute alkali to the reddened paper, and a dark-olive color will be due to boric acid, sharply to be distinguished from the 'deep-red color produced when an alkaline solution is applied to ordinary tur^neric-paper. The turmeric-paper reaction is delicate to I part in 8,000. (2) Tincture of Turmeric Test. — To the solution to be tested, slightly acidified with hydrochloric acid, add an equal volume of saturated tinc- ture of turmeric in an evaporating-dish, and heat for a minute or two. A red color, light or dark, depending on the amount of the preservative, is produced if boric acid be present, changed to an olive color by the addition of dilute alkali, after cooling. (3) The Flame Test. — A few cubic centimeters of alcohol are added to the dish containing the slightly acidulated ash of the sample to be tested, or to the acidulated dried residue from the evaporation of the aqueous solution •of the suspected preservative, and after mixing by the aid of a stirring- rod, the alcohol is ignited. In the presence of any considerable portion of free or combined boric acid, a greenish tinge will be observed in the flame of the burning alcohol, especially at the first flash, due to the boric ether formed. This test is by no means as delicate at the paper test. Determination of Boric Acid in Foods. — (i) Thompson's Method.* — Add I or 2 grams of sodium hydroxide to 100 grams of the sample, and evaporate to drjmess in a platinum dish. Char the residue thoroughly, and boil with 20 cc. of water, adding hydrochloric acid drop by drop till all but the carbon is dissolved. In burning, avoid too high a heat, simply charring sufficiently to insure a clear solution with water. Transfer by washing to a loo-cc. graduated flask, taking care that the volume does not exceed 50 or 60 cc. Add half a gram of dry calcium chloride, then a few drops * Analyst, 18, p. 184. 8;^o FOOD INSPECTION y4ND ANALYSIS. of phenolphthalein solution, and next a io% solution of sodium hydroxide, till a permanent pink color persists. Finally add 25 cc. of lime-water. By this means all phosphoric acid is precipitated in the form of calcium phosphate. Make up to the loo-cc. mark with water, shake, and pour upon a dry filter. To 50 cc. of the filtrate add sufficient normal sulphuric acid to remove the pink color. Then add a few drops of methyl orange, and continue the addition of sulphuric acid till the yellow is just turned to pink. Tenth-normal sodium hydroxide is then added * till the liquid takes on a faint yellow, excess of alkali being avoided. The salts of the acids present at this time are all neutral to phenolphthalein except boric acid and carbon dioxide. Boil the solution to expel the carbon dioxide, cool, add a little more phenolphthalein, and a quantity of glycerin equal in volume to the solution. Finally titrate with tenth-normal sodium hydroxide to a permanent pink color. Each cubic centimeter of tenth- normal sodium hydroxide equals 0.0062 gram crystallized boric acid,. H3BO3, or 0.0035 gram boric anhydride, B2O3, or 0.00955 gram crystal- lized borax, Na2B407,ioH20. (2) Gooch's Method. — Mix 400 to 500 grams of the substance with 10 grams of calcium hydrate, evaporate to dryness over a water-bath in a platinum dish, and burn cautiously to an ash. Dissolve the residue in cold nitric acid, and add an excess of silver nitrate to precipitate the chlo- rine. Filter, make up to 500 cc. with water, shake, and measure out 25 cc into a 200-CC. flask fitted with a stopper provided with an outlet-tube, and with a separatory funnel forming virtually a thistle-tube, capable of being closed with a glass stop-cock. Through the outlet-tube connect the flask with a Liebig condenser provided with an adapter which can dip below the liquid in the receiver. As a receiver, use a 150-cc. tared platinum dish, which contains a weighed quantity of ignited lime in water- Add through the thistle-t-.-be 10 cc. of methyl alcohol to the contents- of the flask, close the stop-cock therein, and distill the contents in a paraf- fin-bath at a temperature of 140° C, constantly stirring the liquid in the- receiver to keep it alkaline during the distillation. Add five successive- portions of methyl alcohol of 12 cc. each to the distilling-flask, and con- tinue the distillation till all the alcohol has passed over. Finally evaporate to dryness the contents of the platinum dish, and ignite over a blast-lamp to constant weight. Multiply the increased weight due to boric oxide by 2.728 to give the equivalent in borax. * If the value of the standard alkali solution is not absolutely certain, it had best be- restandardized against pure crystallized boric acid, 0.31 gram of -which should neutralize 50 cc. of tenth-normal alkali. FOOD PRESERyATlk'ES. 831 SALICYLIC ACID. Salicylic acid (HC7H5O3) is a white, crystalline, strongly acid powder, made synthetically by treatment of carbolic acid with sodium hydroxide and carbon dioxide, or naturally from methyl salicylate (which occurs in oil of wintergreen to the extent of about 90%), by treatment of the winter- green oil with strong potash lye. Most of the commercial salicylic acid is of the synthetic variety. Pure salicylic acid crystallizes from alcoholic solutions in 4-sided prisms, and from aqueous solution in long, slender needles. It melts at 155° to 156° C. It is slightly soluble in cold water (i part in 450), and much more so in hot water. It is readily soluble in ether, alcohol, and chloroform. It is frequently found on the market as a food preservative in the form of the much more soluble sodium salt, sodium salicylate, (NaC^HjOg), which is, however, converted into salicylic acid when added to acid- fruit preparations, condiments, and liquors. Sodium salicylate is a white, amorphous powder, soluble in 0.9 parts water and in 6 parts alcohol. It is prepared by treating salicylic acid with a strong, aqueous solution of sodium carbonate, and afterwards purifying. If a known weight of the powdered preservative be ignited, and a solution of the ash titrated with tenth-normal sulphuric acid, using cochineal as an indicator, each cubic centimeter of the acid is equivalent to 0.0160 gram of sodium salicylate. Salicylic acid is largely used as a preservative of jellies, jams, and fruit preparations, canned vegetables, ketchups, table sauces, wines, beer, and cider. It is rarely used in milk and milk products, or in meats. Bucholz has shown that 0.15% of salicylic acid is sufficient to prevent bacteria from developing in ordinary organic substances, while as small a quantity as 0.04% produces a marked restraining influence. Small amounts of salicylic acid occur naturally in grapes, straw- berries, and other fruits, but the amounts are too small to give distinct color reactions when only 50 grams of the fruit products are used for tests. Detection of Salicylic Acid. — If the sample to be tested is of a similar nature to jelly, jam, ketchup, cider, etc., or capable of getting into aque- ous solution, slightly acidify the liquid or pasty material, diluted, if neces- sary, with weak sulphuric (if not already acid), and shake directly with an equal bulk of ether, petroleum ether, or chloroform, in a corked flask, or in a separatory funnel. If the sample be too thick in consistency ro 832 FOOD INSPECTION ^ND ANALYSIS. shake directly, macerate in a mortar with alkaline water, and strain through cloth. Acidify the filtrate with dilute sulphuric acid, and then proceed to shake with the immiscible solvent as above. Separate by decantation or otherwise the immiscible solvent containing the preservative, if present, and allow it to evaporate in an open slialiow dish, either at room temperature or at a low heat. In case an emulsion forms on shaking, which is quite apt to happen, especially with ether for a solvent, divide the whole mixture between two tubes of a centrifuge of the form shown in Fig. 11, and whirl for three minutes at a high rate of speed. This usually ser\''es to break up the most obstinate emulsion, so that it is easy to separate by decantation. If a considerable amount of salicylic acid be present, it will sometimes appear in the residue in the form of fibrous crystals. (i) To a portion of the dry residue add a drop of ferric chloride solu- tion. A deep purple or violet color indicates salicylic acid * If doubt exists as to the color, dilute with water, which often serves to bring out a distinctive purple coloration otherwise unobservable. (2) Another portion of the residue may be heated with methyl alcohol and sulphuric acid. If salicylic acid be present, the well-known odor of methyl salicylate will be produced. (3) A portion of the dry ether extract is warmed gently with a drop •of concentrated nitric acid, and two or three drops of ammonia are added. Yellow ammonium picrate will be formed if a considerable quantity of salicylic acid be present, and a thread of wool free from fat may be dyed by soaking therein. This test is by no means as delicate as the ferric chloride color test. Instead of evaporating the ether solution of the salicylic acid to dryness, the author prefers to shake out the salicylic acid from the ether with dilute ammonia, evaporate the solution of ammonium salicylate nearly to dryness, and apply the tests given above to the concentrated solution. In this case the ether may be recovered. Determination of Salicylic Acid. — Dubois Method. '\ — In the case of ketchups and similar pulped materials place 50 grams in a graduated 200-cc. flask, make slightly alkaline with ammonia, add 15 cc. of milk * Peters (U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 160) advises the use of chloro- form as more convenient for extraction when testing for salicylic acid, and recommends that the chloroform extract without evaporation be shaken in a test-tube with a drop of ferric chloride reagent and a little water. In the presence of salicylic acid, the violet color will be apparent in the supernatant aqueous layer. t Jour. Am. Chem. Soc, 28, 1906, p. 1616. U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 179. FOOD PRESERyATiyES. 833 of lime (200 grams of quicklime in 2000 cc. water), complete the volume, shake and filter. Transfer 150 cc. of the filtrate to a separatory funnel, acidify with hydrochloric acid, and extract with four portions of 75 to 100 cc. of ether. Wash the combined extract twice with 25 cc. of water, and distil off the ether slowly, allowing the last 20 to 25 cc. to evaporate spontaneously. Dissolve the residue in a small amount of hot water, make up to a definite volume with water, and add to an aliquot portion a few drops of a 2% solution of ferric alum to develop the color. Esti- mate the amount of salicylic acid by matching the color thus obtained with that produced in a solution containing i mg. of salicylic in 50 cc, using either a colorimeter or Nessler tubes for making the comparison. In the case of semisolid materials, such as mince meat, jams, etc., macerate 50 grams with water in a mortar previous to treatment as above described. Liquids and solutions of jellies and other materials free from pulp may be extracted with ether directly after acidifying. BENZOIC ACID Benzoic Acid (HC7H5O2) is produced by the oxidation of a large number of organic substances, particularly toluene. It is also extracted by sublimation from gum benzoin, which exudes from the bark of the Styrax benzoin, a tree growing in Java, Sumatra, Borneo, and Siam. Most of the commercial benzoic acid is made from toluene by treatment with chlorine and subsequent oxidation. Benzoic acid crystallizes in leaflets, having a silky luster. It is odor- less when cold, is soluble in 200 parts of cold, and 25 parts of boiling water, and readily dissolves in alcohol, ether, and chloroform. Its melt- ing-point is 120°, and it sublimes at a slightly higher temperature. It occurs naturally in the cranberry and other berries of the Erlcacecr. Sodium Benzoate (NaC7H502) is the salt most largely used in commer- cial preservatives, being much more soluble than the acid itself, into which, however, it is converted when put into acid fruit preparations. Sodium benzoate is prepared by adding benzoic acid to a concentrated hot solution of sodium carbonate till there is no longer effervescence, and then cooling, and allowing the sodium benzoate to crystallize out. In titrating solutions of ignited sodium benzoate with tenth-noraial sulphuric acid, each cubic centimeter of the standard acid is equivalent to 0.0144 gram of the benzoate. Sodium benzoate is a white amorphous powder, having a sweetish, 834 FOOD INSPECTION AND ANALYSIS. astringent taste, and is soluble in 1.8 parts of cold water, and in 45 parts of alcohol. It is used as a preservative of ketchups, fruit products, soft drinks, codfish, and less often of v^ines. Long, Herter, and Chittenden of the Referee Board of Consulting Scientific Experts, after independent experiments, conclude that sodium benzoate in small doses (less than 0.5 gram per day) is not injurious to health and in large doses (up to 4 grams per day) has not been found to exert any deleterious effects on the general health nor to act as a poison in the general acceptance of the term. Accordingly this preservative is allowed under the federal law provided the presence and amount are declared on the label.* Detection of Benzoic Acid. — Extract with ether or chloroform as directed for salicylic acid. If it is desired to test for both preservatives divide the extract into two parts and evaporate in separate dishes. A considerable amount of benzoic acid is apparent in the residue as shining crystalline scales or needles. In the author's experience a better procedure than evaporating the ether solution is to extract the benzoic acid from the ether by shaking with dilute ammonia, evaporate the solution of ammonium benzoate nearly to dryness, and apply tests to the concentrated solution. (i) Ferric Chloride Test. — A portion of the residue from the ether extract is dissloved in ammonia, and evaporated over the water-bath until neutral to test paper. The residue is stirred in a few drops of warm water, and filtered through a small filter into a narrow test tube. A drop of neutral ferric chloride (prepared by precipitating a portion of the iron from a solution of the salt by ammonia and filtering) is added, and in the presence of benzoic acid a flesh-colored precipitate of ferric benzoate is produced, very characteristic and unmistakable, because of its peculiar color, when the solution in which the test is made is color- less. It occasionally happens, however, in the case of jellies, jams, and ketchups, that these preparations are artificially colored with a dyestuff that persists by its depth of color in obscuring that of the ferric benzoate, especially when only a small amount of benzoic acid is present. Again, in such products as sweet pickles, a precipitate of basic ferric acetate might also come down with the ferric benzoate, and thus confuse. In such cases one of the following methods should be carried out. (2) Sublimation Method.^ — Evaporate an ammoniacal solution of the * Food Inspection Decision 104. t Annual Report, Mass. State Board of Health, 1902, p. 486. FOOD PRESERl/ATiyES. S3 5 ether extract till neutral in a large watch-glass, by the aid of a gentle heat. Fasten with clips or otherwise a second watch-glass to the first, edge to edge, so as to form a double convex chamber, with a cut filter- paper between. Place upon a small sand-bath and heat. Benzoic acid, if present, will sublime upon the surface of the upper glass in minute needles, recognizable under the microscope. It may further be tested by determining the melting-point, or by treating with ammonia, evapo- rating, and applying the ferric chloride test as above. (3) Mohler Method Modified by Heide and Jakob* — Evaporate the ether extract to dryness, take up the residue in i to 3 cc. of third-normal sodium hydroxide, and evaporate to dryness. To the residue add 5 to 10 drops of concentrated sulphuric acid and a small crystal of potassium nitrate. Heat for ten minutes in a glycerol bath at 120° to 130° C. (never higher), or for twenty minutes in a boiling water-bath, thus forming meta- di-nitro benzoic acid. After cooling add i cc. of water and make decidedly ammoniacal; boil the solution, to break up any ammonium nitrite which may have been formed. Cool and add a drop of fresh colorless ammonium sulphide, without allowing the layers to mix. A red-brown ring (ammo- nium meta-di-amido benzoic acid) indicates benzoic acid. On mixing, the color diffuses through the whole liquid; on heating it finally changes to greenish yellow, owing to the decomposition of the amido acid, thus dis- tinguishing benzoic from salicylic or cinnamic acids. Both the latter form amido compounds, which are not destroyed by heating. The presence of phenolphthalein interferes with this test. (4) Peter Oxidation Method.i[ — This method, depending on the formation of salicylic acid, is not applicable in the presence of this acid or saccharin which also oxidizes to salicylic acid. Transfer a portion of the residue, say o.i gram, from the ether or chloro- form extraction to a large test-tube, and dissolve in from 5 to 8 cc. of concentrated sulphuric acid. Add from 0.5 to 0.8 gram of barium per- oxide in successive small portions, shaking the tube in cold water. This should produce a permanent froth on the sulphuric acid solution. After standing for half an hour, fill the test-tube three-quarters full of water, shake, cool quickly, and filter. Extract the filtrate with ether or chloro- form, and test the extract for salicylic acid. Determination of Benzoic Acid. — La Wall and Bradshaw Method. Modified. — This process is based on principles brought to notice by * Zeits. Unters. Nahr. Genuss., 19, 1910, p. 137. A. O. A. C. Method, t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 160. 836 FOOD INSPECTION JND ANALYSIS. Moerck.* Although originally devised for catsup,")" it has been modified by Bigelow J and Dunbar, § so as to be applicable to various classes of foods. The details which follow are those elaborated by Dunbar and adopted by the A. O. A. C. I. Preparation of Solution. — {a) General. — Grind in a sausage- machine,, if solid or semi-solid, and thoroughly mix. Transfer about 150 grams to a 500-cc. flask, add enough pulverized sodium chloride to saturate the water in the sample, make alkaline with sodium hydroxide or milk of lime, and dilute to the mark with saturated salt solution. Allow to stand at least two hours with frequent shaking and filter. If the sample contains- large amounts of matter precipitable by salt solution follow a method similar to that given under {e); if large amounts of fats are present it is well to make an alkaline extraction of the filtrate before proceeding as directed under " Extraction and Titration." {h) Catsup. — To 150 grams of the sample add 15 grams of pulverized sodium chloride. Transfer the mixture to a 500-cc. graduated flask, using about 150 cc. of saturated salt solution for rinsing. Make slightly alkaline to litmus paper with strong sodium hydroxide and complete the dilution to 500 cc. with saturated salt solution. Allow to stand at least two hours with frequent shaking and then filter through a large folded filter. If difficulty is experienced, centrifuge or squeeze the mixture through a muslin bag before filtering. (c) Jellies, Jams, Preserves, and Marmalades. — Dissolve 150 grams of the sample in about 300 cc. of saturated salt solution. Add 15 grams of pulverized sodium chloride. Make alkaline to litmus-paper with milk of lime. Transfer to a 500-cc. graduated flask, and dilute to the mark with saturated salt solution. Allow to stand at least two hours with frequent shaking, centrifuge, if necessary, and filter through a large folded filter. {d) Cider and Similar Products Containing Alcohol. — Make 250 cc. of the sample alkaline to litmus-paper with sodium hydroxide and evaporate on the steam-bath to about 100 cc. Transfer to a 250-cc. flask, add 30 grams of pulverized sodium chloride and shake until dissolved. Dilute to the mark with saturated salt solution, allow to stand at least two hours with frequent shaking, and filter through a folded filter. * Proc. Penn. Pharm. Assn., 1905, p. 181. t Am. Jour. Pharm., 80, 1908, p. 171. X A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 68. § Ibid., Proc. 1909, Bui. 132, p. 158; Circ. 66, p. 14. FOOD PRESERV^Tll^ES. 837- {e) Salt or Dried Fish. — Transfer 50 grams of the ground sample to a 500-cc. iiask with water. Make sHghtly alkaline to litmus-paper with strong sodium hydroxide and dilute to the mark with water. Allow to stand at least two hours with frequent shaking and filter through a folded filter. Pipette at least 300 cc. of the filtrate into a second 500-cc. flask, add 30 grams of pulverized sodium chloride for each 100 cc, shake until dissolved, and dilute to the mark with saturated salt solution. Mix thoroughly and filter off the precipitated protein matter on a folded filter. 2. Extraction and Titration. — Pipette a convenient portion of the filtrate (100 to 200 cc), obtained as above, into a separatory funnel. Neutralize to litmus-paper with hydrochloric acid (i :3) and add an excess of 5 cc. In the case of salt fish, protein matter usually precipitates on acidifying, but this does not interfere with the extraction. Extract care- fully with chloroform, using, for 200-cc. aliquots, successive portions of 70, 50, 40, and 30 cc, and proportional quantities for smaller aliquots. To avoid emulsion, shake each time cautiously. The chloroform layer usually separates readily after standing a few minutes. If an emulsion forms, stir the chloroform layer with a glass rod. If this does not break up the emulsion, draw it ofT into a second funnel and shake sharply once or twice. If this also fails, centrifuge the emulsion for a few moments. Draw off with great care as much of the clear chloroform solution as possible after each extraction. If not contaminated with the emulsion, it is unnecessary to wash the chloroform extract. Transfer the combined chloroform extract to a dish, linsing with chloroform, evaporate to dryness at room temperature, either sponta- neously or in a current of dry air, and dry over night (or, in case of catsup, until no odor of acetic acid can be detected) in a sulphuric acid desiccator. Dissolve the residue of benzoic acid in 30 to 50 cc. of neutral alcohol, add about one-fourth this volume of water, a drop or two of phenolphtha- lein solution and titrate with twentieth-normal sodium hydroxide. One cc. of the standard solution is equivalent to 0.0072 gram anhydrous sodium benzoate. In the absence of a blast an electric fan may be used for evaporating the extract. If it is impracticable to evaporate the chloroform spontr.- neously or by means of a blast it may be transferred from the separatory funnel to a 300-cc. Erlenmeyer flask, rinsing the separatory funnel three times with 5 or 10 cc of chloroform. Distil very carefully to about one- fifth the original volume, keeping the temperature down so that the §38 FOOD INSPECTION AND ANALYSIS. chloroform comes over in drops, not in a steady stream. Then transfer the extract to a porcelain evaporating dish, rinsing the flask three times with 5 or lo cc. portions of chloroform, and evaporate to dryness spon- taneously. The evaporation of the chloroform is best effected by delivering to the dish a blast of air dried by means of a calcium chloride bottle. Hilyer Method.^- — This method is valuable as a check on the La Wall and Bradshaw method. After titrating the benzoic acid obtained as described in the preceding section, proceed as follows : Evaporate to dryness the accurately neutralized solution (which should not have even a slight alkaline reaction), and redissolve in a few cc. of alcohol saturated with silver .benzoate. Filter if not clear, wash with a few drops of alcohol, and treat with lo to 15 cc. of a saturated solution of silver nitrate in alcohol. Collect the precipitate in a Gooch crucible, care being taken that the asbestos filter is so prepared as to afford as rapid a filtration as possible, wash with alcohol, and finally with a little ether, heat in a water-oven until the ether is removed, cool, and weigh. Care must be taken to perform all the operations as quickly as possible to avoid separation of silver oxide. Wesfs Distillation Method. ■\ — i. Apparatus. — The special form of double flask for distillation in a current of steam is the same as that employed by Hortvet J in determining the volatile acids of wine (Fig. 115). The steam tube leading from the outer to the inner flask, being intro- duced half-way up the side of the inner flask, makes it possible to connect the apparatus in such a way that at the beginning of the operation the water in the outer flask will reach to the height of the contents of the inner flask. The side tube leading from the neck of the outer flask is provided with a rubber tube and pinch-cock for use in relieving the steam pressure and avoiding the danger of drawing the contents of the inner flask over into the outer flask, 2. Process. — Weigh into the inner flask of the apparatus 10 grams, add 1.5 to 2.0 grams of paraffin free from volatile matter, and connect "with the condenser. Add 10 cc. of concentrated sulphuric acid, drop by drop, through the funnel tube at such a rate as to complete the addition * A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 74; Circ, ^6, p. 15. t Jour. Ind. Eng. Chem., i, 1909, p. 190. X Ibid., I, 1909, p. 31. FOOD PRESERyATll/ES. 839 in two to three minutes, mix thoroughly by gentle agitation, and allow to stand five to ten minutes after all apparent action of the sulphuric acid has stopped. Measure 150 cc. of distilled water into the outer flask, heat the water slowly to boihng, and continue the boiling until 100 cc. of distillate have been collected, the rate of distillation being such as to yield this amount in 25 to 30 minutes. Filter the distillate into a separatory funnel, and rinse receiver and filter with two lo-cc. portions of water. Shake with three portions of ether, using 50 cc, 30 cc, and 20 cc, and wash the combined ether extracts by shaking with four 50-cc portions of water and a last portion of 25 cc, which portion should not require more than a drop of tenth-normal alkali for neutralization, indicating the complete removal of volatile acids. Transfer the ether extract to a tared, wide-mouthed flask, and distil off the ether on the water-bath as quickly as possible. At just the point where ebullition of the ether ceases, remove the flask from the bath, blow air into it to remove the last traces of ether, and dry in a desiccator over night, or until constant weight is secured. The benzoic acid may also be determined by titration, in which case the filtration of the distillate, also the drying and weighing of the acid, may be omitted. The crystals of benzoic acid are dissolved in alcohol carefully neutralized immediately before each analysis, and the solution titrated with tenth-normal alkali. SULPHUROUS ACID AND THE SULPHITES. Free sulphurous acid in the form of sulphur fumes is extensively' employed to bleach molasses, to disinfect wine casks, and to bleach and preserve dried fruits. This process is known as " sulphuring." It is stated that the sulphur dioxide combines with the acetaldehyde of wines forming aldehyde-sulphurous acid, which is comparatively harm- less. In the case of dried fruits it is believed to form compounds with the sugars. The sulphurous acid salts most commonly employed as food pre- servatives are the bisulphites of sodium and calcium, NaHSOs and Ca(HSO.02. Others used to some extent are the normal sodium sul- phite, and also potassium and ammonium sulphite. The sulphites are usually commercially prepared by passing sulphurous acid gas through strong solutions of the carbonates. Acid sulphites are formed by an excess of the sulphurous acid in the solution of the sulphite. The acid sulphites are distinguishable from the sulphites by their reaction with S40 FOOD INSPECTION ^ND ANALYSIS litmus paper, the former being acid, while the latter are neutral or feebly alkaline. All of these salts have a bitter, salty, and highly sulphurous taste, and possess a very pungent, irritating odor. With the exception of normal calcium sulphite, all of the above are readily soluble in water. The sulphites are most commonly used as preservatives of fruit juices, ketchups, fruit and vegetable pulps, wines, malt liquors and meat prcducts. They are frequently mixed with other antiseptics, as with the salts of salicylic and benzoic acids. Detection and Determination of Sulphurous Acid. — The same methods are used for the detection of sulphurous acid as for its quantitative determination, except that in the former case weighed quantities need not be employed, and the precipitate obtained by the barium sulphate method need not be weighed. Distillation Method. — This method is adapted to all food products whether solid or licpiid. Place 50 to 200 grams of the material in a 500-cc. flask, add water, if necessary, and 5 cc. of a 20% solution of phosphoric acid, and distil in a current of carbonic acid into water containing a few drops of bromine, until 150 cc. have passed over. If sulphides are present, as is true of decomposed meat products and possibly other foods, the steam from the distilling-flask before entering the condenser .should be passed through a flask containing 40 cc. of a 2% neutral solution of cadmium chloride * or a 1% solution of copper sulphate.f These solutions effectually remove the hydrogen sulphide, without retaining any appreciable amount of sulphurous acid. To avoid escape of sulphurous acid the condenser tube should dip below the surface of the bromine solution. The method and apparatus may be simplified without material loss in accuracy by omitting the current of carbon dioxide, adding 10 cc. of phosphoric acid instead of 5 cc, and dropping into the distilling-flask a piece of sodium bicarbonate weighing not more than a gram, immediately before attaching the condenser. When the distillation is finished, boil off the excess of bromine, dilute to about 250 cc, add i cc. of concentrated hydrochloric acid, heat to boiling, and add, drop by drop while boiling, an excess of barium chloride solution. Allow to stand over night in a warm place, filter (preferably on a Gooch crucible with a compact mat of woolly as- * Hornc, U. S. Dept. of Agric, Bur. Chem., Bui. 105, p. 125. t Winton and Bailey, Jour. Am. Chem. Soc, 29, 1907, p. 1499. FOOD PRESERyATiyES. 841 bestos), wash with hot water, ignite at a dull red heat, and weigh as barium sulphate. Direct Titration Method* — This method is applicable to sauternes and other white wines and to beer, but should not be used for other materials, unless found by experiment to yield accurate results. To 25 grams of the sample, finely divided in water if solid or semi- solid, add 25 cc. of a normal solution of potassium hydroxide in a 200-cc. fiask. Shake thoroughly, and set aside for at least fifteen minutes with occasional shaking. 10 cc. of sulphuric acid (1:3) are then added with a little starch solution, and the mixture is titrated with N/50 iodine solution, introducing the iodine solution quite rapidly, and adding it till a distinct fixed blue color is produced, i cc, of the iodine solution is the equivalent of 0.00064 gram SO2. FORMIC ACm, Formic acid (HCOOH) is a colorless liquid at temperatures above 8.3° C. It boils at 101° C.,has a pungent odor and strong caustic action when applied to the skin, causing great pain and ulceration. It occurs naturally in the bodies of certain ants (hence the name) and in small quantities in various vegetable and animal substances. On a commercial scale formic acid is usually prepared by heating glycerol with oxalic acid, the glycerol ester first formed being saponified by a fresh portion of the oxalic acid and the formic acid separated by distillation. Formerly this acid was considered to be less active as a preservative than acetic acid, but more recently it has been shown to be very powerful, a water solution containing less than 0.1% entirely preventing the growth of yeasts and certain bacteria. Recently a 60% solution has come into use as a preservative for fruit products. Detection of Formic Acid. — Bacon Method.-^ — Strongly acidify the solution (which must not contain formaldehyde) with phosphoric acid and distil about one-third of it. To the distillate add dilute sulphuric acid and magnesium filings in sufiicient quantities to cause a vigorous but not a violent evolution of hydrogen. In case quite a large quantity of * U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 90. tU. S. Dept. of Agric, Bur. of Chem., Circ. 74. 842 FOOD INSPECTION AND ANALYSIS. acid is present in the distillate it is not necessary to add any sulphuric acid. If the amount of formic acid is small (about ®.i%) continue the action for one hour; if larger quantities are present the reaction will be complete in a few minutes. Test the solution for formaldehyde by the methods given on page 826. Shannon Method.'^ — Distil in a current of steam about 1000 cc. of the solution, collecting 2500 cc. of distillate in a receiver containing 5 cc. of lead cream. (The latter is prepared by adding sodium hydroxide to a solution of lead nitrate until a faint pink color appears with phenolph- thalein and washing the precipitate 8 to 10 times by decantation.) Shake and as the lead dissolves add a few cc. more of the cream until all the formic acid is combined. Evaporate to about 50 cc, filter and allow to crystallize in a desiccator. Wash the needle-Hke crystals of lead formate with absolute alcohol and dry on filter-paper. An aqueous solution of the crystals should reduce silver nitrate, mer- curic or platinum chloride solution on warming and should yield with sulphuric acid on warming in a test tube, carbon monoxide, which bums in the tube. Distilled with concentrated phosphoric acid, the crystals yield formic acid, identified by the acid reaction, the reducing action on the metallic salts as given above, and the formation of formaldehyde when treated according to the Bacon test. Determination of Formic Acid. — Fincke Method.^ — Dilute 25 to 50 grams of the material to 100 cc, add i gram of tartaric acid and distil in a current of steam until the distillate amounts to 1000-1500 cc Render slightly alkaline with sodium hydroxide and evaporate to 300 cc. To the neutral or slightly acid solution add 3-5 grams of sodium acetate and sufficient mercuric chloride solution (100 grams of mercuric chloride and 30 grams of sodium chloride per liter) so that the amount of mercuric chloride added is at least 15 times the amount of formic acid present Heat on a steam bath under a reflux condenser for two hours. Collect the mercurous chloride on a Gooch crucible, wash with water and finally with alcohol and ether, dry at 100° C. for one hour and weigh. Calculate the formic acid, using the factor 0.0977. If sulphurous acid is contained in the material, oxidize in an alkaline solution with hydrogen peroxide and remove the excess of peroxide with freshly precipitated mercuric oxide. In case salicylic acid is present add I gram of sodium chloride for each 50 cc. of the distillate. * Jour. Ind. Eng. Chem., 4, 191 2, p. 526. t Zeits. Unters. Nahr. Genussm., 21, 1911, p. i. FOOD PRESERl/ATll/ES. 843 To separate from formaldehyde or other aldehydes pass the vapor from the distilling flask through a boiling suspension of i gram of calcium carbonate in 100 cc. of water before condensing. Separate the suspended calcium carbonate by filtering and treat the filtrate as described. Bacon Method.'*' — Distil the solution containing the formic acid with a small quantity of phosphoric acid until the distillate is no longer acid. If the volume of the distillate is too large to be conveniently handled, neutralize it with sodium hydroxide and evaporate to a convenient volume. Add an excess of platinic chloride and sufficient acetic acid to make the solution strongly acid (usually about i or 2 cc. of glacial acetic acid for less than i gram of formic acid), and boil the solution for one hour, using a reflux condenser. Collect the reduced platinum in the usual manner and weigh. The weight of the platinum multiplied by 0.472- equals the formic acid present. FLUORIDES, FLUOSILICATES, AND FLUOBORATES. These substances all possess strong antiseptic qualities, and while no instances are recorded of the use of the last two classes of compounds in this country, the use of fluorides as a preservative of beer is practiced to some extent. The salt most commonly used is ammonium fluoride (NH4F), preparations of this salt being sold commercially under various trade names as beer preservatives. Ammonium fluoride exists as small, deliquescent, hexagonal, flat crystals. Its taste is strongly saline. It is soluble in water, and shghtly soluble in alcohol. Sodium fluoride (NaF) occurs as clear, lustrous crystals, soluble in water. Detection of Fluorides. — Modification of Blarez^ Method.if — Thor- oughly mix the sample and heat 150 cc. to boiling. Add to the boihng liquid 5 cc. of a 10% solution of barium acetate. Collect the precipitate in a compact mass, using to advantage a centrifuge, wash upon a small filter, and dry in the oven. Transfer to a platinum crucible, first break- ing up the dry precipitate and then adding the filter ash to the crucible. Prepare a glass plate (preferably of the thin variety commonlv used for lantern-slide covers) as follows: First thoroughly clean and polish, and coat on one side by carefully dipping while hoi in a mixture of equal parts of Canauba wax and paraffin. Near the middle of the plate make a small cross or other distinctive mark through the wax with a sharp * U. S. Dept. of Agric, Bur. of Chem., Circ. 74. t Mass. State Board of Health An. Rep., 1905. p. 498. Chem. News, 91, 1905, p. 39. 844 FOOD INSPECTION AND ANALYSIS. instrument, such as a pointed piece of wood or ivory, which will remove the wax and expose the glass without scratching the latter. Add a few drops of concentrated sulphuric acid to the residue in the crucible, and cover with the waxed plate, having the mark nearly over the center, and making sure that the crucible is firmly imbedded in the wax. Place in close contact with the top or unwaxed surface of the plate a cooling device, consisting of a glass cylinder the bottom of which is closed with a thin sheet of pure rubber. Keep the cylinder filled with ice water, so that the w^ax does not melt. Heat the bottom of the crucible gently over a low flame or on an electric stove for an hour. Remove the glass plate and indicate the location of the distinguishing mark on the unwaxed surface of the plate by means of gummed strips c^ paper, melt off the wax by heat or a jet of steam, and thoroughly clean the glass with a soft cloth. A distinct etching will be apparent on the glass where it was exposed, if fluoride be present. Detection of Fluoborates and Fluosilicates.* — Two hundred cc. of the wine or other sample are made alkaline with lime water, evaporated to dryness, and ignited. The crude ash is first extracted with water acidified with acetic acid, and the solution filtered. The insoluble residue is again ignited and extracted with dilute acetic acid, which is filtered off and added to the first extract. The filtrate contains the boric acid, if present, and this is tested for as directed on page 829. Calcium, silicate or fluoride, if present, is in the insoluble portion. Incinerate the filter with the insoluble portion, transfer the ash to a test-tube, mix with some silica, and add a little concentrated sulphuric acid. A small U-tube should be attached to the test-tube, containing a very little water. The test-tube is immersed for half an hour in a beaker of water kept hot on a steam-bath. In the presence of fluoride, silicon fluoride will be generated, and will be decomposed by the water, forming a gelatinous deposit on the walls of the tube. If both boric and hydrofluoric acids are found, the compound present is undoubtedly a borofluoride. If no boric acid is found, but silicon fluoride is detected, repeat the operation, but without the added silica. If the silicon skeleton is then formed, fluosilicate is probably present. * U. S. Dept. of Agric, Bur. of Chem., Eul. 59, p. 63. FOOD PRESEKl^^TIl^ES. 845 BETA-NAPHTHOL. Beta-naphthol (C10H7OH) is a phenol, occurring naturally in coal- tar, but the commercial product is more commonly prepared artificially from naphthalene by digesting the latter with sulphuric acid, and fusing the product with alkali. It is a colorless, or pale buff-colored powder, with a faint phenolic odor and a sharp taste. It is slightly soluble in water, and readily soluble in alcohol, ether, and chloroform. Its melting-point is 122° C. In alcoholic solution it is neutral to litmus. It is used to some extent in alcoholic solution as a preservative of cider. Detection of Beta-Naphthol. — Bube * states that if an ethereal extract of beta-naphthol is evaporated to dryness, and the residue dissolved in hot water made first faintly alkaline with ammonia, and then faintly acid with veiy dilute nitric acid, a beautiful rose color will be developed on the addition of a drop of fuming nitric acid or of a nitrite. He declares the test to be a delicate one, but it is apparently sometimes obscured by interfering substances, which the ether may dissolve. It should also be carried out in a faint light, as strong sunlight affects the color. Ferric chloride, when applied to an aqueous solution of beta-naph- thol, produces a greenish coloration. Shake about 50 grams of the sample to be tested with chloroform in a separatory funnel, evaporate the chloroform extract to a small volume (say I or 2 cc), transfer to a test-tube, add 5 cc. of an aqueous solution of potassium hydroxide (1:4), and warm gently. If beta-naphthol is present, a deep-blue color will appear in the aqueous layer, turning through green to light brown. ASAPROL, OR ABRASTOL. These are trade names for calcium a-mono-suiphonate of beta- naphthol, Ca(CioH8S030H)2, a white, odorless, scaly powder, sometimes slightly reddish, obtained by the action of heated sulphuric acid on beta- naphthol, the resulting compound being afterwards treated with a calcium salt. It is readily soluble in water and alcohol, and is neutral in reaction. Its taste is at first slightly bitter, but rapidly changes to sweet. It decom- poses at about 50° C. * Analyst, 13 (1888), p. 52. 846 FOOD INSPECTION AND ANALYSIS. The writer is unaware of any instance of the presence of this substance in foods, but its character is such as to adapt it for use as a preservative of wines and possibly other food products. It has long been regarded as a possible preservative, and the analyst should be prepared to encounter it at any time. Detection of Asaprol. — SinahaldVs Method."^ — The portion of the solution to be tested (say 50 cc.) is made slightly alkaline with ammonia, and shaken with 10 cc. of amyl alcohol in a separatory funnel. Alcohol is often useful in breaking up an emulsion if there is one. Separate the amyl alcohol extract, which if turbid is filtered, and evaporate to dry- ness. Wet the residue with about 2 cc. of nitric acid (1:1), heat on the water-bath till the volume is about i cc, and wash with a few drops of water into a narrow test-tube. Next add about 0.2 gram of ferrous sul- phate and ammonia in excess, a drop at a time, constantly shaking the solution. If a reddish-colored precipitate is formed, it is dissolved by the addition of a little sulphuric acid, and further additions of ferrous sulphate and ammonia are made as before. When a dark-colored or green precipitate appears, add 5 cc. of alcohol, dissolve in sulphuric acid, shake, and filter. If abrastrol be present to the extent of o.oi gram or more, a red coloration is observed, while in its absence, the filtrate is colorless or faintly yellow. If the solution to be tested is a fat, it should be melted and extracted with hot 20% alcohol, which is evaporated to dryness, and the above test carried out on the dry residue. REFERENCES ON PRESERVATIVES AND THEIR USE IN FOOD. Abel, R. Zum Kampfe gegen die Konservierung von Nahrungsmitteln durch Anti- septica. Hyg. Runds., 1901, 265-281. Annett, H. E. Boric Acid and Formaline as Milk Preservatives. Thompson Yates Lab. Reports, Liverpool, Vol. II, 1900, pp. 57-67. Baldwin, H. B. Toxic Action of Sodium Fluoride. Jour. Am. Chem. Soc, 21, 1899, p. 517. Benedicenti. Action of Formaldehyde on Various Proteid Substances. Archw. f. Anat. u. Physiolog., 1897, p. 219. Behre, a., u. Segin, a. Ueber die Wirkung der Konservierungsmittel. Zeits. Unlers. Nahr. Genuss., 12, 1906, p. 461. *Mon. Sol., 1703 ,(4), 7, p. 842; U. S. Dept. Agric, Bur. of Chem., Bui. 59, p. 91. FOOD PRESERVATli^ES. 847 BiscHOFF, H., and Wintgen, U. Beitrage zur Konservenfabrikation. Ztsch. fiir Hyg., Bd. 34, 1900, Heft 3, 496-513- Bliss and Now. Action of Formaldehyde on Enzymes. Jour. Exp. Med., 4, 47. Chittenden, R. H. Influence of Borax and Boracic Acid on Digestion. Diet, and Hyg. Gazette, 9, 1893, 25. Chittenden and Gies. Effects of Borax and Boric Acid on Nutrition. New Yorit Med. Jour., FeL\, 1898. Experiments with Borax and Boric Acid on the Lower Animals. Am. Jour, of Phys., Vol. I, No. I, 1898. DiGHT, C. F. Effect of Boric Acid and Borax on the Human Body. Minneapolis, 1902. FoLiN and Flanders. Determination of Benzoic Acid. J. Am. Chem. Soc, 2>3>y 1911, p. 161. GoxnN, R. Le Beurre et I'Acide Borique. Jour. d'Agricult prat., 1900, p. 14-16. Gruber. Ueber die Zulassigkeit der Verwendung der Fluoride zur Konservierung von Lebensmittel. Das Oesterr. Sanitatsw., 1900, 4. — — • Ueber die Zulassigkeit der Verwendung von Chemikalien zur Konservierung von Lebensmittel. Das Oesterr. Sanitatsw., 1900. GriJnbaum, a. S. Note on the Value of Experiments in the Question of Food Pre- servatives. Brit. Med. Jour., 1901, p. 1337. Halliburton, W. D. Remarks on the Use of Borax and Formaldehyde as Preserva tives of Food. Brit. Med. Jour., 1900, pp. 1-2. Heffter, a. Ueber den Einfluss der Borsaure auf die Ausnutzung der Nahrung. Arbeiten aus dem kaiserlichen Gesundheitsamte, Bd. 19, Part i, 1902, p. 97. Hill, A. Antiseptics in Food. Pub. Health Jour., London, 11 (1901), 527. Hope, E. W. Preservatives and Coloring Matters in Foods. Thompson Yates Lab. Reports, Vol. Ill (1900), pp. 75-78. Jacobj, C, u. Walbatjm, H. Zur Bestimmung der Grenze der Gesundheitsschadlich- keit der Schwefligen Saure in Nahrungsmitteln. Arch. Exp. Path. Pharm., 54, 1906, p. 421. Kjckton, a. Ueber die Wirkung einiger sogenannter Konservierungsmittel auf Hackfleisch. Zeits. Unters. Nahr. Genuss., 13, 1907, p. 534. Kister, J. Ueber Gesundheitschiidlichkeit der Borsauer als Konservierungsmittel fiir Nahrungsmittel. Zeit. f. Hygiene, Bd. 37, 1901, Heft 2, p. 225. Lauge, L. Beitrage zur Frage der Fleischkonservierungmittel. Borsaure, Borax und Schwefeligsauren Natronzusatzen. Mit einem Anhang. Milchkonservierung betr. Arch. f. Hygiene, Bd. 40, 1901, 2, pp. 143-186. Lebbin, G. Die Konservierung und Farbung von Fleischwaaren. Hyg. Rund., 11, No. 23. Lebbin u. Kallmann. Ueber die Zulassigkeit Schwefehgsauer Salze in Nahrungsmit- teln. Zeits. fiir offentl. Chem., 7, 17, 324-334. Lebbin, G. Preservation and Coloring of Meat Produce. Translated from the German. Should the Use of Boric Acid as a Food Preservative be Permitted ? Translated from the German of Die medicinische Woche, Sept., 1901. Leffmann, H. Food Preservatives. Penn. Board of Agric, An. Rep., 1897, 535. 848 FOOD INSPECTION AND ANALYSIS. Leffmann, H. Influence of Preservatives on Digestive Enzymes. Diet, and Hyg. Gazette, 14, 718. Hygienic Relations of Boric Acid and Borax. Diet, and Hyg. Gazette, 14, 171. Digestive Ferments and Preservatives. Jour. Frankl. Inst., 147 (1899), 97. Lepierre. Action of Formaldehyde on Proteids. Bui. Soc. Chem., 21 (1899), p. 729. LiEBREiCH, O. Effects of Borax and Boric Acidon theHuman System. London, 1902. The So-called Danger from the Use of Boric Acid in Preserved Foods. Lancet, 1900, pp. 13-15. Die Verwendung von Formalin zur Konservierung von Nahrungsmitteln. Therap. Monatsh., 18, 1904, p. 59. Zur Frage der Bor-Wirkungen. Berlin, 1906. LoEW. Action of Formaldehyde 011 Pepsin and Diastase. Jour. f. prakt. Chem., 37, 1888, p. lOI. Low, W. H. Boric Acid: its Deflection and Determination in Small and Large Amounts. Jour. Am. Chem. Soc, 28, 1906, p. 807. Neumann, R. O. Ueber den Einfluss des Borax auf dem Stoffwechsel des Menschen. Arbeiten aus dem kaiserlichen Gesundheitsamte, Bd. 19, Pt. i, 1902, p. 89. POLENSKE. Ueber den Borsauregehalt von frischen und geraucherten Schweineschin- ken. Loc. cit., 167. Price, J. M. Die Einwirkung einiger Konservierungsmittel auf die Wirksamkeit der Verdauungsenzyme. Centralb. Bakt. II Abt., 14, 1905, p. 65. RiDEAL, S. Formalin as a Milk Preservative. Analyst, 20, p. 157. Disinfection and the Preservation of Food. London and New York, 1903. On the Use of Boric Acid and Formic Aldehyde as Mjlk Preservatives. Public Health Jour., London, 11, 1901, p. 554. RoHARDT, W. Ueber Konservierung von fnschem Fleisch und iiber Fleischkonserven von Hygienischen- und Sanitats-polizeilichem Standpunkt aus. Vierteljahres- schrift f. gerichtl. Med., 1901, Heft 2, p. 321. RosT, E. Ueber die Wirkungen der Borsaure und des Borax auf den thierischen und menschlichen Korper, mit besonderer Beriicksichtigung ihrer Verwendung zum Konservieren von Nahrungsmitteln. Arbeiten aus dem kaiserlichen Gesund- heitsamte, Bd. 19, Part i, 1902, p. i. Zur Kenntnis der Ausscheidung der Borsaure. Arch, internat. Pharm. Thfr., 15, 1905, P- 291- RosT, E., u, Franz, F. Pharmakologische Wirkungen der Schwefligen Saure. Arb. Kaiserl-Gesundsheitsamt, 21, 1904, p. 312. RuBNER. Ueber die Wirkung der Borsaure auf den Stoffwechsel des Menschen. Loc. cit., Bd. 19, Part I, 1902, p. 70. SoNNTAG, G. Ueber die Quantitative Untersuchung des Ablaufs der Borsaureaus- scheidung aus dem menschlichen Korper. Loc. cit., no. Stroscher, a. Konservierung u. Keimzahlen des Hackfleishes. Arch. f. Hyg., 40, 1901, pp. 291-319. Tunincliffe, F. W., and Rosenheim, O. On the Influence of Formaldehyde upon the Metabolism of Children. Jour, of Hygiene (London), Vol. I, 3, 1901. On the Influence of Boric Acid and Borax upon the General Metabolism of Children. Loc. cit., supra, 1901, Vol. I, No. 2, pp. 168-202. FOOD PRESERyATiyES. 849 Vaughan, V. C, and Veenboer, W. H. The Use of Boric Acid and Borax as Food Preservatives. Am. Medicine, March, 1Q02. Vaillard, L. Les Conserves ahmentaires de Viande. Rev. d'Hyg., 1900, pp. 789-792. Walbaum, H. Die Gesundheitsschadlichkeit der Schwefligen Saure und ihrer Ver- bindungeii unter besonderer Beriicksichtigung der freien Schwefligen Saure. Arch. Hyg., 57, 1906. p. 87. Weitzel, A. Ueber die Labgerinnung der Kuhmilch unter dem Einfluss von Borpra- paraten und anderen chemischen Stoffen. Arbeiten aus dem kaiserlichen Gesundheitsamte, Bd. 19, Part i, 1902, p. 126. Wiley, H. W. Influence of Food Preservatives and Artificial Colors on Digestion and Health. U. S. Dept. of Agric, Bur. of Chem., Bui. 84. Part I, Boric Acid and Borax; Part II, Salicylic Acid and Salicylates; Part III, Sulphurous Acid and Sulphites; Part IV, Benzoic Acid and Benzoates; Part V, Formal- dehyde. Report of the Departmental Committee appointed to Inquire into the Use of Preservatives and Coloring Matters in the Preserving and Coloring of Food. 497 pp. London. Report of Referee Board of Consulting Experts appointed by the Secretary of Agriculture, on the Influence of Sodium Benzoate on the Nutrition and Health of Man. Chittenden, R. H., Long, J. H., and Herter, C. A. U. S. Dept. of Agric, Report No. 88, Washington, 1909. U. S. Food Inspection Decisions: No. 76, Dye.s, Chemicals, and Preservatives in Foods. No. 89, Amendment to No. 76. No. loi, Benzoate of Soda. No. 104, Amendment to Nos. 76 and 89. CHAPTER XIX. ARTIFICIAL SWEETENERS. Under this head are included the intensely sweet coal-tar derivatives, such as saccharin, dulcin, and glucin, that possess no food value whatever in themselves. From their high sweetening power, in some cases several hundred times that of cane sugar, they are capable, when used in minute quantity, of imparting an appropriate degree of sweetness to food products, which, on account of the use of inferior materials, or by reason of the presence of inert or less sweet adulterants, would otherwise be lacking in this property. Such canned vegetables as sweet corn and peas are subject to treat- ment with saccharin, especially if by their age and condition before can- ning they are wanting in the sweet, succulent taste inherent in the fresh product. The sweetening power of commercial glucose is considerably less than that of cane sugar, so that when large admixtures of the glucose are used in such products as jellies, jams, honey, molasses, maple syrup, etc., to the exclusion of cane sugar, the presence of the glucose might in some cases be suggested by the bland taste of the food, unless reinforced by one of the artificial sweeteners. The analyst should therefore be on the outlook for one or another of these concentrated sweetening agents in all of the above classes of foods, especially in saccharine products wherein glucose is found to pre- dominate largely over the cane sugar, while the taste is not lacking in sweetness. The use of saccharin in foods other than those specially de- signed for invalids is not allowed under the federal law. SACCHARIN. Saccharin or Gluside, Benzoyl sulphimide (C6H4.CO.SO2NH), is a white powder, composed of irregular crystals, whose melting-point, when 850 ARTIFICIAL SIVEETENERS. 851 pure, is about 224° C. It is prepared from toluene, which by treatment with concentrated sulphuric acid is first converted into a mixture of ortho- and para-toluene sulphonic acids. These are further converted into corresponding chlorides, and from the orthochloride, by treatment with ammonia, the imide is formed. It is soluble in 230 parts of cold water, 30 parts of alcohol, and 3 parts of ether. It is sparingly soluble in chloro- form, but readily soluble in dilute ammonia. It is from 300 to 500 times as sweet as cane sugar, and, unlike cane sugar, it is not, when pure, charred by the action of concentrated sulphuric acid even on heating. Its aque- ous solution is distinctly acid in reaction. Pure saccharin, when heated under diminished pressure, can be sublimed without decomposition. The addition of i part of saccharin to 1,000 parts of commercial glucose renders the latter as sweet as cane sugar. A sodium salt of saccharin is found on the market, prepared by neutral- izing a solution of saccharin with sodium hydroxide or carbonate. The sodium salt crj^stallizes in the form of rhombic plates, forming a white powder readily soluble in water, and possessing nearly the same sweeten- ing power as saccharin. It is sometimes put up in the form of tablets for the use of diabetic patients as a substitute for sugar. Saccharin, aside from its sweet taste possesses, according to Fahlberg and List,* antiseptic properties, and on this account it is sometimes used in beer and other liquors. Squibb states that saccharin has about the same power as boric acid as an antiferment Detection of Saccharin in Foods. — If the sample to be tested is a solu- tion or syrup, render it acid, if not already such, with phosphoric acid, and extract with ether. In case of canned vegetables and similar goods, finely divide the material by pulping or maceration in a mortar, dilute with water, and strain through muslin. Acidify the filtrate, and extract with ether.f If an emulsion forms, use a centrifugal machine (p. 25), Separate the extract, evaporate off the ether, and test the residue for saccharin as follows : (i) Add to the residue, if it tastes sweet, a few cubic centimeters of hot water^ or preferably a very dilute solution of sodium carbonate, in which saccharin is more soluble. An intensely sweet taste is indicative of its presence. This test, if applied directly, will sometimes fail, espe- cially in the case of beer, by reason of the extraction by the ether of various * Jour. Soc. Chem. Ind., IV, p. 608. t Allen states that a purer residue is obtained if the sample of beer be treated with lea• Mexican Maximum Minimum .\verage Bourbon Maximum Minimum Average Seychelles Maximum Minimum Average. .' Madagascar Maximum Minimum Average. ...... Comores Maximum Minimum Average South American. . Maximum Minimum Average Ceylon Maximum Minimum Average Java Maximum Minimum Average Tahiti Maximum Minimum Average Vanillons Tonka Beans t-- ■ Maximum Minimum A\-erage -All Analyses %.. . . Maximum Minimum Average AU Analyses %. . . . (2d Extraction) Maximum Minimum Average i6 i6 i6 i6 23 10 i6 % 0.20 o.is o. 17 O. 22 0.13 O. 21 o. i6 O. 19 0.30 o. 16 O. 22 0.31 O. 12 0.18 0.23 0. 19 0.08 0.07 o.oS o. 24 O. 22 0.23 O. II O. II O. II 0.06 % 0.68 0.47 0.58 0.63 0.44 0.52 0.60 0.45 o.Si 0.63 0.40 0.50 0.74 0.40 0.59 0.58 0.49 0.52 0.67 0.57 0.62 0.50 0.44 0.47 0.52 O. II 0. II 0.74 0.40 0.S4 O. II 0.03 O.OS S6 19 32 47 25 34 40 SO 42 61 40 0.61 45 o . 44 44 44 17 IS 16 42 S s s S6 IS 32 154 ss 97 127 6s 94 162 77 107 148 8S III ISS 117 134 195 145 162 177 130 150 SO 40 4S 107 19 18 19 177 40 102 8.0 4-8 6.5 2.4 4 S- 9 7. 3-4 l.O 2.6 1-4 2.0 2.6 1.4 1.9 7.6 1-4 4-3 3.2 2.4 2.9 0.6 0.6 0.6 1.4 o.S o.S o.S 3.4 0.6 14.6 5-0 7-9 rr-S 6.2 8.7 12.6 6.0 7.7 10.4 6.8 8.S 32.6 6.4 18.2 13.4 10.4 I ■. I 3.S 31 3-3 6.6 2.4 2.4 2.4 14.6 31 7.6 % 3.8 2.6 3.1 3-9 2.3 3.2 3.6 2.S 3-2 3S 2.7 3.2 3.8 2.^ 3.2 S-7 2.5 3.4 24.4 19.0 30.3 21.3 26.6 29.4 22.7 25.6 30.3 23.2 26.8 30.3 20. 4 26.7 29.4 20.0 23 3 36.1 35-7 32.2 34 5 18.8 16.0 17.4 22. 2 31.2 30.3 30.8 35-7 16.0 2S.S 6.5 3.0 4.6 * Calculated to volume of extract. t Coumarin: Maximum, 0.27% ; minimum. 0.22% ; average, O. 25%. % Excluding Ceylon, Vanillons, and Tonka Beans. 862 FOOD INSPECTION AND /tNALYSIS, Guiana, known as Dipterix (or Coumarouna) odorata. The pods are almond-shaped, and contain a single seed, from 3 to 4 cm. long, shaped like a kidney bean, of a dark-brown color, having a thin, shiny, rough, brittle skin, and containing a two-lobed oily kernel. Coumarin (C9Hg02), the active principle of the Tonka bean, is the anhydride of coumaric acid. It occurs in the crystalline state between the lobes of the seed kernel. Coumarin occurs also in many other plants. It may be extracted from the beans by treatment with alcohol. It crys- tallizes in slender, colorless, needles, melting at 67° C. It has a fragrant odor and burning taste. It is very slightly soluble in cold water, but readily soluble in hot water, ether, chloroform, and alcohol. One pound of cut beans yields by alcoholic extraction about 108 grains of coumarin. The latter may be synthetically prepared by heating salicylic aldehyde with sodium acetate and acetic anh3^dride, forming aceto-coumaric acid, which decomposes into acetic acid and coumarin. The author has found that an aqueous solution of coumarin, unlike vaniUin, forms a precipitate when iodine in potassium iodide is added in excess, the precipitate being at first brown and flocculent, afterwards, on shaking, clotting together to form a dark-green, curdy mass, leaving the liquid perfectly clear. U. S. Standards. — Vanilla extract is the flavoring extract prepared from the vanilla bean, with or without sugar or glycerin, and contains in 100 cc. the soluble matters from not less than 10 grams of the vanilla bean. Vanilla bean is the dried, cured fruit of Vanilla planifolia Andrews. Tonka extract is the flavoring extract prepared from tonka bean, with or without sugar or glycerin, and contains not less than 0.1% by weight of coumarin extracted from the tonka bean, together with a correspond- ing proportion of the other soluble matters thereof. Tonka bean is the seed of Coumarouna odorata Aublet {Dipteryx odorata (Aubl.) Willd.). The Adulteration of Vanilla Extract consists chiefly in the use of coumarin or extract of the Tonka bean, and in the substitution of artifi- cial vaniUin, either alone or with coumarin, for the true extractives of the vanilla bean. Imitation vanilla flavors more often consist of a mixture of either tincture of Tonka or coumarin with vanillin in weak alcohol, colored with caramel, or occasionally with coal-tar colors. Or the exhausted marc from high-grade vanilla extract is macerated with hot water and extracted, the extract being reinforced with artificial vanillin or coumarin, or both. A pure vanilla extract possesses FLAVORING EXTRACTS AND THEIR SUBSTITUTES, 863 certain peculiarities with regard to its resins ^nd gums that distinguish it from the artificial, or indicate whether or not it has been tampered with. While it is possible to introduce artificial resinous matter in the adulterated brands with a view to deceiving the analyst, it is almost impossible to do this without detection, since different reactions are readily apparent in this case from those of the pure extracts. Prune juice is said to be used to give body and flavor to vanilla extract. The writer has found spirit of myrcia or bay rum in a sampL. of alleged vanilla extract, containing also vanillin and coumarin. The adulterant in this sample was present to such an extent as to be unmis- takable by reason of the odor. Factitious Vanilla Extracts are ordinarily indicated (i) by the presence of coumarin, (2) by the peculiar reactions of the resinous matter, or by the entire absence of these resins, (3) by the scanty precipitate with lead acetate, and (4) by the abnormally low or high content of vanillin. The following figures show the content of vanillin and coumarin in a few typical cheap " vanilla " extracts, selected from a large number examined by the author. All of these were entirely artificial, and ranged from 5 to 20 per cent by weight of alcohol. Vanillin, Coumarin, Per Cent. Per Cent. A 0.040 0.074 B None 0.172 C None 0.330 D 0.250 None E.„ 0.025 0.144 As a rule these cheap artificial preparations possess considerable body and flavor, but the latter is of a much grosser nature than the genuine vanilla extract, with the dehcate and refined flavor of which they are not to be mistaken by any one at all familiar with both varieties. Winton and Bailey* have found as high as 2.55% of vanillin in imitation extracts. They also have detected the presence of acetanihde in amounts varying up to 0.15%. This substance at one time was extensively employed as an adulterant of vaniUin, hence its presence in imitation extracts prepared from such vanillin. It is not only worthless as a flavor, but is a menace to health. * Conn. Agric. Exp. Sta., Rep. 1905, p. 131. 864 f'OOD INSPECTION AND ANALYSIS. -n the limits of composition for standard vanilla extract given on page 870, the range in vanilhn content is from o.io to 0.35%. • METHODS OF ANALYSIS OF VANILLA EXTRACT Detection of Artificial Extracts. — The presence of coumarin or Tonka tincture to any appreciable extent in vanilla extract is usually recognizable by the odor, to one skilled in examining these flavors. The odor of cou- marin is more pungent and penetrating than that of vanillin, and in mix- tures is apt to predominate over the milder and more delicate odor of vanillin. Add normal acetate of lead solution to a suspected extract. The absence of a precipitate is conclusive evidence that it is artificial. If a precipitate is formed, much information may be gained by its character. A pure vanilla extract should yield with lead acetate a heavy precipitate, due to the various extractives. The precipitate should settle in a few minutes, leaving a clear, supernatant, partially decolorized liquid. If only a mere cloudiness is formed, this may be due to the caramel present, and in any event is suspicious. Examination of the Resins. — Resin is present in vanilla beans to the extent of from 4 to 11 per cent, and the manufacturer of high-grade essences endeavors to extract as much as possible of this in his product. This he can do by the use of 50% alcohol, in which all the resin is readily soluble, or by employing less alcohol and relying on the use of alkali to dissolve it. A pure extract free from alkali should produce a precip- itate, when a portion of the original sample is diluted with twice its volume of water and shaken in a test-tube. When, moreover, the alcohol is removed from such an extract, the excess of resin is naturally precipitated. The character of the resins extracted from the vanilla bean is so dif- ferent from that of other resins as to furnish conclusive tests, worked out by Hess * as follows: 25 to 50 cc. of the extract are de-alcoholized by heating in an evaporating-dish on the water-bath to about one-third its volume. Make up to the original volume with water, and, if no alkali has been used in the manufacture of the preparation, the resin will be in the form of a brown, flocculent precipitate. To entirely set free the resin, acidify, after cooling, with dilute hydrochloric acid, and allow to stand till all the resin has settled out, leaving a clear supernatant liquid. The resin may be quantitatively determined, if desired, by filtering, wash- * Jour. Am. Chem. Soc, 21 (1899), p. 721. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 865 ing, diying, and weighing, but in this case should stand for a long time before filtering. The resin is collected on a filter, washed, and subjected to various tests. A piece of the filter with the attached resin is placed in a beaker, containing dilute potassium hydroxide. Pure vanilla resin dissolves to a deep-red color, and is reprecipitated on acidifying with hydrochloric acid. Dissolve another portion of the precipitate in alcohol, and divide the alcoholic solution into two portions, to one of which add a few drops of ferric chloride, and to the other hydrochloric acid. Pure vanilla resin shows no marked coloration in either case, but foreign resins nearly all give color reactions under these conditions. Tannin. — Test a portion of the filtrate from the resin for tannin by the addition of a few drops of a solution of gelatin. A small quantity of tannin only should be indicated, if the extract is pure, a large excess tending to show added tannin. Determination of Vanillin and Coumarin. — Modified Hess and Prescott Method. — This process, in its original form devised by Hess and Prescott,* has been modified by Winton, collaborating with Silverman,! Bailey,J Lott,§, and Berry, || in order to prevent loss of coumarin, detect the presence of acetanilide, and permit the determination of normal lead number in the same weighed portion. It depends on the principle that ammonia water, acting on the ether solution of vanillin and coumarin, forms with] the aldehyde vanillin a compound soluble in water, but does not affect the coumarin, which remains in solution in the ether. Weigh 50 grams of the extract directly into a tared 250-cc. beaker with marks showing volumes of 80 and 50 cc, dilute to 80 cc, and evapo- rate to 50 cc. in a water-bath kept at 70° C. Dilute again to 80 cc. with water and evaporate to 50 cc. Transfer to a loo-cc. flask, rinsing the beaker with hot water, add 25 cc. of standard lead acetate solution (80 grams of C. P. crystallized lead acetate, made up to one Hter), make up to the mark with water, shake, and allow to stand eighteen hours at a temperature of from 37° to 40° C, in a bacteriological incubator, in a water-bath provided with a thermostat, or in any other suitable apparatus. * Jour. Am. Chem. Soc, 21, 1899, p. 256. t Ibid., 24, 1902, p. 1 1 28. % Ibid., 27, 1905, p. 719. § A. O. A. C. Proc. 1909, U. S. Dept. of Agric, Bur. of Chem., Bui. 132, p. 109. II U. S. Dept. of Agric, Bur. of Chem., Circ. 66. 866 FOOD INSPECTION AND ANALYSIS. Filter through a small dry filter and pipette off 50 cc. of the filtrate into a separatory funnel. If a determination of normal lead number is desired, pipette off 10 cc. of the filtrate into a beaker, and proceed as described on page 867. In the latter case, the water used throughout the process should be boiled until free from carbon dioxide. If coloring with caramel is suspected determine the color value of the original extract and the filtrate (p. 869). To the 50 cc. of the filtrate in the separatory funnel, add 20 cc. of ether and shake. Draw off carefully the aqueous liquid, together with any ether emulsion and then remove the clear ether solution to another sepa- ratory funnel. Repeat the shaking of the aqueous liquid with ether three times, using 15 cc. each time. Shake the combined ether solutions four or five times with 2% ammo- nium hydroxide, using 10 cc. for the first shaking and 3 cc. for each subsequent shaking. In drawing off the ammoniacal solution, care should be taken not to allow any of the ether solution to pass through with it. Reserve the ammoniacal solution for the determination of vanillin. Transfer the ether solution to a weighed dish and allow the ether to evaporate at room temperature. Dry in a sulphuric acid desiccator and weigh. If the residue is pure coumarin, it should have a melting- point of 67° C, respond to the Leach test, and be completely soluble in three or four portions of petroleum ether (boiling-point 30° to 40° C), stirring with each portion fifteen minutes. If a residue remains in the dish after decanting off the last portion of the petroleum ether solution, acetanilide should be looked for (p. 868). Add to the ammoniacal solution 10% hydrochloric acid to slightly acid reaction. This should be done without delay, as the ammoniacal solution on standing grows slowly darker with a loss of vanillin. Cool, and shake out in a separatory funnel with four portions of ether, as described for the first ether extraction. Evaporate the ether solution at room temperature in a weighed dish, dry over sulphuric acid, and weigh. The residue should be pure vanillin free from any appreciable amount of color and with a melting-point of 80° C. If the percentage of vanillin is not desired, and coumarin only is to be separated for gravimetric determination, the author has found that good results are usually obtained by simply treating the dealcoholized original sample with ammonia, extracting it with 3 or 4 portions of chloroform in a separatory funnel, and evaporating the combined chloroform extract in a tared dish at a temperature not exceeding 60° in the oven. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 867 Many of the precautions employed in carrying out the above processes for vanillin and coumarin determination may be dispensed with if these substances are simply to be tested for qualitatively. Leach Test for Coumarin. — The residue, believed to be coumarin, obtained as described in the preceding section, is identified by the follow- ing test: Add a few drops of water, warm gently, and add to the solu- tion a little iodine in potassium iodide, reagent No. 143. In presence of coumarin a brown precipitate will form, which, on stirring vidth the rod, will soon gather in dark-green flecks. The reaction is especially marked if done on a white plate or tile. Wichmann Test for Coumarin. — Dilute 25 cc. of the extract with 25 cc. of water, slightly acidify, if alkaline, with sulphuric acid, and distil to dryness. To the distillate, containing the vanillin and coumarin, add 15 to 20 drops of 1:1 potassium hydroxide, hastily evaporate to 5 cc, transfer to a test tube and heat over a free flame until the water com- pletely evaporates and the residue fuses to a colorless, or nearly colorless mass. Cool the melt and dissolve in a few cubic centimeters of water, trans- fer to a 50 cc. Erlenmeyer flask and acidify slightly with 25% sulphuric acid. Finally distil the solution (which should not exceed 10 cc.) into a test tube containing four or five drops of neutral 0.5% ferric chloride. If coumarin is present in the original extract, a purple color will develop, the intensity being proportional to the amount of coumarin. Vanillin and Coumarin Crystals under the Microscope. — ^These sub- stances are best examined when crystallized from ether solution, and several crystallizations may be found necessary, before the best results are obtained. For examination, pour a few drops of the ether solution of the purified vanillin or coumarin directly on a slide, and allow to evaporate spontaneously. Under best conditions vanillin crystallizes from ether in long, slender needles, often radiating from central points, or forming star-shaped bundles. Coumarin crystals are shorter and thicker than vanillin. With polarized light pure vanillin crystals give a brilliant play of colors between crossed nicols, even without the selenite plate, while pure coumarm crystals without the selenite are almost lacking in varying colors, and show very little play, even when the selenite is employed. This sharp distinction is not true when crystallized from chloroform. Determination of Normal Lead Number. — Winton and Lott Method. — Mix the lo-cc. aliquot of the filtrate from the lead acetate precipitate, obtained in the determination of vanillin and coumarin (p. 866), with 868 FOOD INSPECTION AND ANALYSIS. 25 cc. of water, boiled until free from carbon dioxide, and a moderate excess of sulphuric acid. Add 100 cc. of 95% alcohol, and mix again. Let stand over night, filter on a Gooch crucible, wash with 95% alcohol, dry at a moderate heat, ignite at low redness for three minutes, taking care to avoid the reducing flame, and weigh. The normal lead number is calculated by the following formula: „ 100X0.6831(5-!^) P= p -^ = 13.662 {S-W), in which P = normal lead number, 5 = grams of lead sulphate corre- sponding to 2.5 cc. of the standard lead acetate solution as deter- mined m blank analyses, and PF = grams of lead sulphate obtained in 10 cc. of the filtrate from the lead acetate precipitate, as above described. The standard of the lead acetate solution as determined by blank analyses does not change appreciably on standing; it should, however, be checked from time to time, especially if the bottle is opened frequently, thus permitting absorption of carbon dioxide. In all steps of the process only water free from carbon dioxide should be used. Pure vanilla extract of standard strength should have a normal lead number not less than 0.40. Dilution diminishes the number propor- tionately. For example, a mixture containing 50% of vanilla extract should have a normal lead number not less than 0.20 and so on. Determination of Acetanilide. — Winton and Bailey Method. — If in the determination of vanillin and coumarin (p. 865) a residue is found after thoroughly stirring the coumarin with three or four 15-cc. portions of petroleum ether and decanting off the liquid; allow this residue to stand at room temperature until apparently dry and finish the dry- ing in a sulphuric acid desiccator. Weigh and deduct the weight from that previously obtained, thus obtaining the true amount of coumarin. The residue, if acetanilide, should melt at 112° C. and respond to Ritsert's tests as given below. If acetanilide is found in the coumarin it will also be present in the vanillin, although in smaller amount. Dissolve the weighed residue of impure vanillin in 15 cc. of 10% ammonium hydroxide solution, shake twice with ether, evaporate the ether solution at room temperature, dry in a sulphuric acid desiccator, and weigh. Deduct this weight from the h'L^yORING EXTRACTS AND 7 HEIR SUBSTITUTES. 809 weight of impure vanillin, thus correcting for the amount of acetanilide present. The total weight of acetanilide is found by adding the weight of the portion separated from the coumarin to that separated from the vanillin. Ritsert's Tests for Acetanilide.* — Boil the acetanilide, obtained as described above, in a small beaker for two or three minutes with 2 to 3 cc. of concentrated hydrochloric acid, cool, divide into three por- tions, and test in small tubes (4 to 5 mm. inside diameter), or by spotting on a porcelain plate, as follows: (i) To one portion add carefully i to 3 drops of a solution of chlorinated, lime (1:200) in such a manner that the two solutions do not mix. A beautiful blue color formed at the juncture of the two liquids indicates acetanilide. (2) To another portion add a small drop of potassium permanganate solution. A clear green color is formed if any appreciable amount of acetanilide is present. (3) Mix the third portion with a small drop of 3% chromic acid solution. Acetanilide gives a yellow-green solution, changing lo dark green on standing five minutes, and forming a dark blue precipitate on addition of a drop of caustic potash solution. These tests are conclusive only when taken in conjunction with the melting-point. Determination of Glycerin. — The presence of any considerable quantity of glycerin is apparent by the character of the residue obtained on evaporat- ing 5 grams to dryness, in the determination of total solids. The residue, if glycerin is present in notable amount, appears of a moist consistency, even when a practically constant weight has been attained at 100° C. To determine glycerin, proceed as with wines (p. 703). Determination of Alcohol. — Measure out 25 cc. of the sample, dilute to 50 cc. with water, and distil off about 20 cc. in a 25-cc. graduated receiver. Make up to the mark with water, determine the specific gravity at 15.6°, and find from the alcohol table the per cent corresponding. Cane Sugar and Glucose are determined as in the case of preserves and jellies. Detection of Caramel. — Lead Acetate Method. — Dealcoholize, precipi- tate with lead acetate, and filter, as described for the determination of vanillin and coumarin (page 865). If the extract is pure, the filtrate * Pharm. Ztg. 33, 1888, p. 383; Abs. Zeits. anal. Chem., 27, 1888, p. 667. Sjo FOOD INSPECTION AND ANALYSIS. will be light yellow; if colored with caramel, the filtrate will be yellow brown or deep brown, according to the amount present. More definite conclusions may be reached by determining the color values of the original extract and the lead acetate filtrate in terms of yellow and red of the Lovibond scale and calculating the ratio of the two colors, also the percentage of each color remaining in the filtrate. The reading of the extract is made in the i-inch cell after diluting 2 cc. to 50 cc. with 50% alcohol, while that of the filtrate is made directly in a i- inch cell or, if very dark, in a half or quarter inch cell. Color Insoluble in Amyl Alcohol. — Evaporate 25 cc. of the extract on a water-bath until no odor of alcohol is apparent and the liquid is reduced to a thick sirup, then proceed as described on page 753. Limits of Composition for Standard Vanilla Extract. — The following are suggested by Win ton and Berry: Vanillin, o.io to 0.35%. Normal lead number, 0.40 to 0.80%. Percentof total color in lead filtrate, not more than io%redori2%yellow. Ratio of red to yellow in the extract, not less than i : 2.2. Color insoluble in amyl alcohol, not more than 40%. Coal-tar Colors are detected by the usual tests (pp. 795 to 818). LEMON EXTRACT. Spirit or essence of lemon of the National Formulary and former editions of the Pharmacopoeia, is a 5% solution (by volume) of lemon oil in deodorized alcohol, colored with lemon peel. This preparation was dropped from the 8th revision of the Phar- macopoeia, and Tinctura limonis corticis or tincture of lemon peel added. The following are the directions for the preparation of the latter: "Lemon peel, from the fresh fruit, in thin shavings and cut in narrow shreds 500 grams "Alcohol, a sufficient quantity to make 1000 cc. " Macerate the lemon peel in a stoppered, wide-mouthed container, in a moderately warm place, with 1000 cc. of alcohol during forty -eight hours, with frequent agitation; then filter through purified cotton, and, when the liquor has drained off completely, gradually pour on enough alcohol to make 1000 cc. of tincture, and filter." U. S, Standards. — Lemon Extract is the flavoring extract prepared from oil of lemon, or from lemon peel, or both, and contains not less than 5% by volume of oil of lemon. FLAl^ORING EXTRACTS AND THEIR. SUBSTITUTES. 871 Oil of Lemon {?, the volatile oil obtained, by expression or alcoholic solution, from the fresh peel of the lemon {Citrus limonum L.), has an optical rotation (25° C.) of not less than +60° in a loo-mm. tube, and contains not less than 4% by weight of citral. Terpendess Extract of Lemon is the flavoring extract prepared by shaking oil of lemon with dilute alcohol, or by dissolving terpeneless oil of lemon in dilute alcohol, and contains not less than 0.2% by weight of citrai derived from oil of lemon. Terpeneless Oil of Lemon is oil of lemon from which all or nearly all of the terpenes have been removed. The U. S. standard for lemon extract (5% of lemon oil by volume) is a fair one. In fact there are commercial extracts on the market containing as high as 12%. An extract of lemon to contain 5% of lemon oil must contain at least 80% by volume of alcohol, lemon oil being insoluble in dilute alcohol. Deodorized, or purified alcohol, com- monly known as cologne spirits or perfumers' alcohol, is used in the highest-grade preparations, since the odor of ordinary commercial alcohol produces a slightly deleterious effect. Adulteration of Lemon Extracts. — For making a cheap extract the cost of the lemon oil is not so important an item as that of the alcohol, and as little as possible of the latter is employed, though pure oil is doubtless used. These terpeneless extracts are made by rubbing the oil in carbonate of magnesia in a mortar, stirring in slowly a little strong alcohol, and allowing the mixture to soak for some time. A varying amount of water is added a little at a time, and the whole is shaken and again allowed to stand, sometimes for a week, before filtering. Finally the extract is filtered, and the coloring matter added, consisting sometimes of turmeric tincture and sometimes of coal- tar dyes. In these cheap extracts the per cent of alcohol often runs below 40, and as little as 4.5% by volume of alcohol has been found by the author in a commercial extract. With less than 45% of alcohol by volume, no appreciable amount of oil is dissolved, only a portion of citral, though such preparations are sometimes bottled as " pure extract of lemon." Time and again manufacturers have protested to the author that the purest oil was used by them, when notified that their brand contained no oil, or when prosecuted in court, and were with difhculty convinced that the trouble with their goods was that, on account of weak alcohol employed, the lemon oil used failed to get into the final product. It is true that a certain taste or odor of the lemon is present, even in cheap varieties wherein no oil is found, due to the fact that 872 FOOD INSPECTION AND ANALYSIS. even dilute alcohol, when slowly percolating through the magnesia in which the oil is finely distributed, does abstract therefrom a certain amount of citral, which is, however, but a mere shadow of the sub- stance and body possessed by a strong alcoholic solution of oil of lemon. In many instances, where formulas appear stating the name and per cent of ingredients, these formulas are entirely deceptive and mis- leading, in that the statements are not borne out on analysis. The flavor of the cheap extracts is sometimes reinforced by the addition of such substances as citral, oil of citronella, and oil of lemon- grass, but minute quantities only of these pungent materials can be used,, not exceeding 0.33% in the case of citral, and 0,1% in the case of the two last mentioned oils. Cane sugar and glycerin are sometimes found. U. S. P. tincture of lemon peel owes its color to natural substances extracted by the alcohol. This color, however, readily fades on exposure to light. Other coloring matters employed are largely coal-tar dyes, and occasionally tincture of turmeric or saffron. During 1901 practically all the brands of lemon extract sold in Massa- chusetts were collected and analyzed. 167 samples were examined^ representing about 100 brands, and 139 samples were classed as adul- terated, based on 5% lemon oil as a standard, and depending on whether or not the contents conformed to the labels on the bottles. The typical analyses, given in tables on p. 873, are selected from the tabulated results of the above examination.* Forty-two samples contained no lemon oil, ranging in content of alcohol from 4 to 45 per cent. METHODS OF ANALYSIS OF LEMON EXTRACT. A. S. Mitchell was the earliest among food chemists to systematically examine lemon extract, and to him are due the methods for determin- ing oil of lemon, as well as various other tests now adopted provision- ally by the A. O. A. C.f Detection of Oil of Lemon. — If on adding a large excess of water to a little of the extract in a test-tube no cloudiness occurs, the oil may *An. Rep. Mass. State Board of Health, 1901, p. 459; Food and Drug Reprint, p. 41. ' t Jour. Am. Chem. Soc, 21, 1899, p. 1132; U. S. Dept. of Agric, Bur. of Chem., BuL 65, p. 73; Bui. 107 (rev.), p. 159. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 873 LEMON EXTRACTS OF STANDARD QUALITY. Polarizatioa Lemon Oil, Specific Alcohol, in 200-mm. Per Cent by Gravity at Per Cent by Foreign Ingredient*. Tube. Volume. 15.6-^0. Volume. 30.8 9.1 0.8280 84-39 Turmeric 26.0 7-6 0.8402 80.49 23-5 6.9 0-8352 81.74 Dinitrocresol 21.8 6.4 0.8396 82.88 20.0 5-9 0-8335 84.24 18.0 5-3 0.8268 86.82 17.0 5-0 0.8496 80.06 INFERIOR OR ADULTERATED LEMON EXTRACTS. Polarization Lemon Oil, specific Alcohol, in 200-mni. Per Cent by Gravity at Per Cent by Foreign Ingredients. Tube. Volume. 15.6° C. Volume. 14.0 . 4-1 0.8592 77.62 Dinitrocresol 12.2 3-6 0.8644 76 08 < ( II. 3-1 0.8620 77 50 A coal-tar dye 9-9 2.9 0.8615 77 90 8.0 2-3 0.8531 81 61 Dinitrocresol 6.8 2.0 0.8416 87 55 TropEolin S-o 1-5 0.8832 71 10 ' ' 3-5 I.O 0.8939 67 68 2.8 0.8 0.8995 65 23 Dinitrocresol 2.2 0.6 0.8941 67 69 " 1-4 0.4 0.9136 59 40 A nitro dye 0.3 O.I 0.9408 46 40 Dinitrocresol 0.0 0.0 0-9937 4 49 Tropffiolin -8.0 0.0 .. Invert sugar 27.0 0.0 27 49 Cane sugar 0.0 0.0 47 35 Oil other than lemon fairly be inferred to be absent. The degree of cloudiness produced is proportional to the amount of lemon oil present. Determination of Lemon Oil. — MitchelVs Methods. — (i) By Polariza- tion. — Polarize the undiluted extract in a 200-mm. tube at 20° C. Divide the reading on the Ventzke cane sugar scale by 3.4, and if cane sugar or other optically active substances are absent, the quotient expresses the per cent of lemon oil by volume. With instruments reading in circular degrees, divide the rotation in minutes at 20° C. by 62.5. If the Laurent instrument with sugar-scale is used, divide the sugar-scale reading by 4.8. Cane sugar, though rarely found in lemon extract, is occasionally used in small amount. It is Scid to aid in the solution of the oil. If it is present, wash the solid residue from 10 cc. of the sample (dried on a water-bath) with three portions of 5 cc. each of ether, to remove waxy 874 FOOD INSPECTION AND ANALYSIS. and fatty matters, dry and weigh the residue of cane sugar, deducting 0.38 from the reading for each 0.1% of sugar so found. (2) By Precipitation. — Transfer by a pipette 20 cc. of the extract to a Babcock milk-flask, add i cc. of dilute hydrochloric acid (1:1); add 25 to 28 cc. of water previously warmed to 60° C. ; mix, and stand in water at 60° for five minutes; whirl in a centrifuge for five minutes; fill with warm water to bring the oil into the graduated neck of the flask, and repeat the whirling for two minutes; stand in water at 60° for a few minutes, and read the per cent of oil by volume. Where the oil of lemon is present in amounts over 2%, add to the percentage of oil found 0.4% to correct for the oil retained in solution. Where less than 2% and more than 1% is present, add 0.3% for correction. Save the precipitated oil for the determination of refraction. When the extract is made in accordance with the U. S. Pharma- copcEia, the results by the two methods just given should agree within 0.2%. To obtain per cent by weight from per cent by volume, as found by either of the above methods, multiply the volume percentage by 0.86, and divide the result by the specific gravity of the original ex- tract. Howard's Modification of Mitchell's Precipitation Method.* — Pipette 10 cc. of the extract in a Babcock milk bottle, and add in the following order, 25 cc. of cold water, i cc. hydrochloric acid (specific gravity 1.2), and 0.5 cc. chloroform. Close the mouth of the bottle with the thumb, and shake vigorously for not less than one minute. Whirl the bottle in a centrifuge for one and one-half to two minutes, thus forcing the chloro- form and oil to the bottom of the bottle, and remove all but 3 or 4 cc. cf the clear supernatant liquid by means of a glass tube of small bore connected with an aspirator. To the residue add i cc. of ether, agitate thoroughly, plunge the bottle to the neck in a boiling-water bath, holding at shght angle, and rotate in the bath for exactly one minute. This step is best carried out by removing one of the small rings from a water- or steam-bath and holding the bottle in the live steam. The ether serves the purpose of steadily and rapidly sweeping out every trace of chloroform with- out appreciable loss of oil. Finally, cool the bottle, fill nearly to * Jour. Am. Chem. Soc, 30, 1908, p. 608. FLAyORING EXTRACTS AND THEIR SUBSTITUTES. 875 the top of the neck with water at room temperature, centrifuge for one-half minute, read the column of separated oil to the top meniscus, and multiply the reading by two, thus obtaining the per cent of oil. This method may also be used for determining the oil in extracts of orange, peppermint, clove, cinnamon, and cassia, employing in the case of the heavier oils dilute sulphuric acid (1:2), instead of water, in filling the bottles before the last centrifuging. Determination of Alcohol. — Mitchell has shown that the difference in specific gravity between oil of lemon and stronger alcohol is not so great, but that a very close approximation to the true percentage of alcohol in lemon extracts may be obtained from the specific gravity itself, assum- ing, of course, that foreign substances, such as sugar, glycerin, etc., are absent. In the absence of such foreign substances determine the specific gravity of the sample, ascertain from the alcohol tables on pages 661- 674, the per cent of alcohol by volume corresponding. This gross figure includes the lemon oil, the per cent of which should be deducted for the correct per cent of alcohol. In the absence of oil of lemon, a measured portion of the original sample may be distilled, and the percentage of alcohol determined from the distillate in the usual manner, but when lemon oil is present, this should first be removed by diluting 50 cc. of the extract with water to 2CO cc. exclusive of the oil in the sample, and shaking the mixture with 5 grams of magnesium carbonate in a flask, filtering through a dry filter, and determining the alcohol by distillation in a por- tion of the filtrate. The result is multiplied by 4 to correct for the dilution. Determination of Total Aldehydes.^C/faceV Method."^ — i. Reagents. ■ — (a) Aldehyde-free Alcohol. — Allow alcohol (95% by vol.) containing 5 grams of metaphenylene diamine hydrochloride per liter to stand for twenty-four hours with frequent shaking. Previous treatment with potassium hydroxide is unnecessary. Boil under a reflux cooler for at least eight hours, allow to stand over night and distil, rejecting the first 10 and the last 5 per cent which come over. Store in a dark, cool place in well-filled bottles. 25 cc. of this alcohol, on standing for twenty minutes in the cooling bath with the fuchsin solution * Jour. Am. Chem. Soc, 28, 1906, p. 1472. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 32. -875 FOOD INSPECTION AND ANALYSIS. (20 cc), should develop only a faint pink coloration. If a stronger color is developed, treat again with metaphenylene diamine hydro- chloride. (6) Fuchsin Solution. — Dissolve 0.5 gram of fuchsin in 250 cc. of water, add an aqueous solution of sulphur dioxide containing 16 grams of the gas, and allow to stand until colorless, then make up to i liter with distilled water. This solution should stand twelve hours before using, and should be discarded after three days. (f) Standard Citral Solution. — Use i mg. of c. p. citral per cc. in 50% by volume aldehyde-free alcohol. This solution deteriorates on standing, and should not be kept over three or four days. 2. Apparatus. — (a) A Cooling Bath. — Keep at from 14 to 16° C. The aldehyde-free alcohol, fuchsin solution, and comparison tubes are to be kept in this bath. (b) Colorimeter. — Any form of colorimeter, using a large volume of solution and adapted to rapid manipulation, may be used. The comparison may also be made in Nessler or Hehner tubes. 3. Manipulation. — Weigh in a stoppered weighing flask approxi- mately 25 grams of extract, transfer to a 50-cc. flask, and make up to the mark at room temperature with aldehyde-free alcohol. Measure at room temperature and transfer to a comparison tube 2 cc. of this solution. Add 25 cc. of the aldehyde-free alcohol (previously cooled in a bath), then 20 cc. of the fuchsin solution (also cooled), and finally make up to the 50-cc. mark with more aldehyde-free alcohol. Mix thoroughly, stopper, and place in the cooling bath for fifteen minutes. Prepare a standard for comparison at the same time and in the same manner, using 2 cc. of the standard citral solution. Remove and compare the colors developed. Calculate the amount of citral present and repeat the determination, using a quantity sufficient to give the sample approximately the strength of the standard. From this result calculate the amount of citral in the sample. If the comparisons are made in Nessler tubes, standards con- taining I, 1.5, 2, 2.5, 3, 3.5, and 4 mg. should be prepared, and the trial comparison made against these, the final comparison being made with standards between 1.5 and 2.5 mg., varying but 0.25 mg. It is absolutely essential to keep the reagents and comparison tubes at the required temperature. Comparisons should be made within one minute after removing the tubes from the bath. Where the comparisons are made in the bath (this being possible only where the bath is glass), the standards should be discarded within twenty-five minutes after FLAyORING EXTRACTS AND THEIR SUBSTITUTES. 877 adding the fuchsin solution. Give samples and standards identical treatment. Determination of Citral. — Hiltner's Method.^ — i. Reagents. — {a) Metaphenylene Diamine Hydrochloride Solution. — Prepare a 1% solution in 50% ethyl alcohol. Decolorize by shaking with fuller's earth or animal charcoal, and filter through a double filter. The solution should be bright and clear, free from suspended matter and practically colorless. It is well to prepare only enough solution for the day's work, as it darkens on standing. The color may be removed from old solutions by shaking again with fuller's earth. ih) Standard Citral Solution. — Dis.solve 0.250 gram of c. p. citral in 50% ethyl alcohol and make up the solution to 250 cc. (c) Alcohol. — For the analysis of lemon extracts, 90 to 95 per cent alcohol should be used, but for terpeneless extracts alcohol of 40 to 50 per cent strength is sufficient. Filter to remove any suspended mat- ter. The alcohol need not be purified from aldehyde. If not prac- tically colorless, render slightly alkaline with sodium hydroxide and distil. 2. Apparatus. — The Schreiner colorimeter (page 77) or Eggertz tubes may be used. With this latter apparatus, alcohol is added, small quantities at a time, to the stronger colored solution until after shaking and viewing transversely, the colors in the two tubes are exactly matched. Calculations are then made by estabhshing a proportion between the volumes of samples taken and the final dilutions. 3. Manipulation. — All of the operations may be carried on at room temperature. Weigh into a 50-cc. graduated flask 25 grams of the extract, and make up to the mark with alcohol (90-95 per cent). Stopper the flask and mix the contents thoroughly. Pipette into the colorimeter tube 2 cc. of this solution, add 10 cc. of metaphenylene diamine hydro- chloride reagent, and complete the volume to 50 cc. (or other standard volume) with alcohol. Compare at once the color with that of the standard, which should be prepared at the same time, using 2 cc. of standard citral solution and 10 cc. of the metaphenylene diamine reagent, and making up to standard volume with alcohol. From the result of this first determination, calculate the amount of standard citral solution that should be used in order to give approximately the same citral strength of the sample under examination, then repeat the determination. * A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 34. Jour. Ind. Eng. Chem., i, 1909, p. 798. 878 FOOD INSPECTION AND ANALYSIS.] Methyl Alcohol has been used by unscrupulous manufacturers in lemon extracts. It is detected and determined by the refractometer method of Leach and Lythgoe (page 749). As a confirmatory test for methyl alcohol the distillate, after testing- by the Leach and Lythgoe method, may to advantage be subjected to the method of Mulliken and Scudder,* which depends on the conversion of the methyl alcohol to formaldehyde. The latter method is also useful as a rough preliminary test on the original extract without distillation, the extract, being, however, first diluted until the liquid contains approxi- mately 12% by weight of alcohol, shaking with magnesium carbonate, and filtering when lemon oil is present. Oxidize 10 cc. of the liquid in a test-tube as follows: Wind copper wire I mm. thick upon a rod or pencil 7 to 8 mm. thick, in such a manner as to inclose the fixed end of the wire, and to form a close coil 3 to 3.5 cm. long. Twist the two ends of the wire into a stem 20 cm. long, and bend the stem at right angles about 6 cm. from the free end, or so that the coil may be plunged to the bottom of a test-tube, preferably about 16 mm. wide and 16 cm. long. Heat the coil in the upper or oxidizing flame of a Bunsen burner to a red heat throughout. Plunge the heated coil to the bottom of the test-tube containing the diluted alcohol. Withdraw the coil after a second's time and dip it in water. Repeat the operation from three to five times, or until the film of copper oxide ceases to be reduced. Cool the liquid in the test-tube meanwhile by immersion in cold water. Tesl for Formaldehyde. — Divide the oxidized liquid in the test-tube into two parts, testing one for formaldehyde with pure milk by the hydrochloric acid and ferric chloride test. Test the other portion by Mulliken and Scudder's resorcin test for formaldehyde, page 826, avoid- ing an excess of the reagent. t Tests for Colors. — Evaporate a portion of the sample to dryness^ dissolve the residue in water, and extract coal-tar colors if present by Arata's method, page 796, or with hydrochloric acid. Much information may often be gained by treatment of the original extract with strong hydrochloric acid. If the color employed be turmeric^ no change in color will be evident on addition of the acid. If tropasolin or methyl orange is present, the solution will turn pink, while partial decoloration of the solution indicates naphthol yellow S, and complete decoloration shows presence of dinitrocresols or naphthol yellow. * Am. Chem. Jour., 23, 1899, p. 266. f Ibid , 24, 1900, p. 451. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 879- Test for turmeric by boric acid, page 791. Detection of Lemon and Orange Peel Coloring Matter. — Alhrech Method.'^ — Place a few cubic centimeters of the extract in a test-tube and add slowly 3 or 4 volumes of concentrated hydrochloric acid. Place a few cubic centimeters of the extract in a second tube and add several drops of concentrated ammonia. In the presence of lemon or orange peel color the yellow tint of the original extract will be materially deep- ened in both cases. Determination of Total Solids and Ash. — Total Solids are estimated by evaporating on the water-bath 10 grams of the sample in a tared dish, and drying at 100° to constant weight. If glycerin be present, it is dif- ficult if not impossible to get a constant weight. Cane sugar and glycerin, if present, will be apparent in the residue. If capsicin has been used, it will be noticed by the taste. Burn to an ash the residue from the solids in a muffle at a low red heat, cool in a desiccator, and weigh. Glycerin is determined as in wine, page 703. Detection of Tartaric or Citric Acid. — To a portion of the extract in a test-tube add an equal volume of water to precipitate the oil. Filter and add one or two drops of the filtrate to a test-tube half full of cold, clear lime water. If tartaric acid is present, a precipitate will come down, which is soluble in an excess of ammonium chloride or acetic acid- Filter off the precipitate, or, if no precipitate is visible, heat the con- tents of the tube. Citric acid will precipitate in a large excess of hot lime water. Examination of Lemon Oil. — The oil separated from the extract in the process of determining the lemon oil by precipitation (p. 874), is most readily examined for its purity, after drying with calcium chloride,-. by determination of its specific gravity, its index of refraction, or its refractometric reading with the Zeiss butyro-refractometer, and its polari- scopic reading. The specific gravity and refractometric readings are determined as with fixed oils, using with the butyro-refractometer a sodium flame or yellow bichromate color-screen, which gives perfectly sharp readings without dispersion. The first table on page 880 shows readings on the Zeiss butyro- refractometer of pure lemon oil at various temperatures, using the sodium light. A.O.A.C. Method, Proc. for 1910, U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 71. 88o FOOD INSPECTION /IND ANALYSIS. For examination of high polarizing essential oils like oil of lemon, the author employs a 50-mm. tube, in order to get the readings on the imdiluted oil well within the limits of the cane sugar scale on the polar- iscope. If such a tube is not available, dilute the oil with an equal volume of alcohol, and use the loo-mm. tube. The second table given below expresses constants of pure lemon oils and of various commonly employed adulterants, as determined in the laboratory of the Massa- chusetts State Board of Health. READINGS ON ZEISS BUTYRO-REFRACTOMETER OF LEMON OIL. Tempera- Scale Tempera- Scale Tempera- Scale Tempera- Scale ture, Centigrade. Reading. ture, Centigrade. Reading. ture, Centigrade. Reading. ture, Centigrade. Reading. 40.0 59-4 35-0 62.8 30.0 66.3 25.0 69.7 39-5 59-7 34-5 63.1 29-5 66.6 24-5 70.0 39-0 60.1 34-0 63-5 29.0 67.0 24.0 • 70.4 38.S 60.4 33-5 63.8 28.5 67-3 23-S 70.7 38.0 60.8 33-0 64.2 28.0 67.7 23.0 71. 1 37-5 61.0 32-5 64-5 27-5 68.0 22.5 71.4 37-0 61.5 32.0 64.9 27.0 68.4 22.0 71.8 .36.5 61.8 31-5 6^.1 26.5 68.7 21.5 72.1 36.0 62.1 31.0 65.6 26.0 69.0 21-0 /2-5 35-5 62.4 30-5 65.9 25-5 69-3 20.5 72.8 35-0 62.8 30.0 66.3 25.0 69.7 20.0 73-2 CONSTANTS OF SOME ESSENTIAL OILS. OiL Butyro-refractometer (Sodium Light) at — Temp. Reading. Rotation in 100- Millimeter Tube, Ventzke Scale. Specific Gravity at i';.6°C. Oil of lemon (lowest) " " " (highest) " " " grass (A. Giese) " " citronella (A. Giese) Terpeneless oil of lemon (Hansel 's) " " " " grass (Hansel's) Citral (A. Giese) 25- 25- 22.5 22.5 23- 23- 22.5 69-5 71.2 96.9 87.1 87.9 91.0 95-0 173-0 184-5 -10.8 — 10.2 — 22.0 -5-6 -3-6 0.8580 0.8610 0.9309 0-9437 0-9463 0.9232 0-9296 Oil of Lemon is a light-yellow liquid, having the pleasant odor of fresh lemons, and an aromatiq, mild, somewhat bitter after taste. It is obtained from the grated rind of the lemon either by treatment with hot water, skimming off the oil which rises to the surface, or by pressure, or by distillation with water. It is rapidly changed by action of air and light, becoming "terpeney," and under these conditions its solubility in alcohol seems to increase. Its composition is somewhat uncertain, FLAl^ORING EXTRACTS AND THEIR SUBSTITUTES. 38 1 but according to Wallach * nearly 90% consists of hydrocarbons, mostly terpenes, the most important of n-hich is the terpene hmonene f of the dextro-gyrate variety, also known as citrene. Another important constituent of lemon oil is the aldehyde citral, present to the extent of from 4 to 5 per cent. To this the odor of the oil is largely due. A second aldehyde, citronellal, is also present. A frequent adulterant of lemon oil is turpentine oil, which lowers the rotation considerably, and is thus most easily rendered apparent. Chace | detects small quantities of turpentine by the difference in crystalline form of pinene nitroso-chloride from that of limonene nitroso- chloride. Citral (CioHigO) is an aldehyde present in lemon oil and in oil of lemon-grass, and, while it may be separated from these oils, is prepared artificially by oxidizing geraniol with chromic acid.§ It is a mobile oil, and when perfectly pure is optically inactive. The commercial citral is, however, slightly laevo-rotary, due no doubt to impurities. Oil of Lemon-grass is distilled from lemon-grass, Andropogon citratus (D. C), cultivated in India. It is reddish yellow in color, and has an intense lemon-like odor and taste. Very little is known of its composi- tion, but it seems to contain several aldehydes, one of which is citro- nellal, and another citral. The latter, however, is its chief constituent, being present to the extent of 70 to 75 per cent. Citronellal (CioHigO) is an aldehyde found in various oils, especially in citronella oil, from which it is readily separated. It is made artificially by the oxidation of the primary alcohol citronellol (CigHjoO). It is quite strongly dextro-rotary. Oil of Citronella is distilled from the grass Andropogon nardus (L.), growing chiefly in Ceylon, India, and tropical East Africa. It is a yel- lowish-brown liquid with a pleasant and lasting odor. Citronellal is present in this oil to the extent of from 10 to 20 per cent, and the oil contains also from 10 to 15 per cent of terpenes, among which are camphene. Tests for Citral, Citronellal, and Limonene. || — Shake 2 cc. of the sample to be examined in a corked test-tube with 5 cc. of a solution of * Liebig's Annalen, 227, p. 290. t There are two limonenes, one of which is dextro- and the other laevo-rotary. The two are completely ahke in their behavior, differing only in their optical rotation. X Jour. Am. Chem. Soc, 30, 1908, p. 1475. § Tiemann, Berichte, 31, p. 331 1. II Burgess, Chem. and Drugg., 57, p. 732. 882 FOOD INSPECTION AND ANALYSIS. I lo grams of mercuric sulphate in sufficient 25% sulphuric acid to make 100 cc. Citral yields a bright-red color, which rapidly disappears, leav- ing a whitish compound, which floats on top. Citronellal forms a bright- yellow color, remaining for some time. Limonene forms an evanescent, faint flesh color, and leaves a white compound. METHODS OF ANALYSIS OF LEMON OIL. The following are the methods of the A.O.A.C.* They apply to orange as well as lemon oil. Determination of Specific Gravity. — Determine the specific gravity by means of a pycnometer or a Sprengel tube at 15.6° C. Determination of Index of Refraction. — Determine the index of refrac- tion with any standard instrument, making the reading at 20° C. Determination of Rotation. — Determine the rotation at 20° C. with any standard instrument using a 50-mm. tube and sodium light. The results should be stated in angular degrees on a loo-mm. basis. If instruments having the sugar scale are used, the reading on orange oils is above the range of the scale, but readings may be obtained by the use of standard laevo reading quartz plates. Determination of Citral. — Kleher Method. — i. Reagents. — {a) Phenyl Hydrazin. — A 10% solution of the purified chemical in absolute alcohol. A sufficiently pure product can be obtained by rectification of the com- mercial article, rejecting the first portions coming over which contain ammonia. {h) Hydrochloric Acid. — A half normal solution. 2. Manipulation. — Weigh 15 grams of the sample into a small glass- stoppered flask; add 10 cc. of the phenyl hydrazin solution. After allow- ing to stand for half an hour at room temperature, titrate with half normal hydrochloric acid, using either methyl or ethyl orange as indicator. Titrate 10 cc. of the phenyl hydrazin reagent in the same manner. The difference in cubic centimeters of half normal acids betwe^^n this titra- tion and that of the sample, multiplied by the factor 0.076, gives the weight of citral in the sample. If difficulty is experienced in detecting the end point of the reaction, carry out the titration until the solution is distinctly acid, transfer to a separatory funnel, and draw off the alcoholic portion. Wash the oil with water, adding the washings to the alcoholic solution, and titrate back with half normal alkali, making the necessary corrections. * U. S. Dept. of Agric, Bui. 137, 1911, p.. 72. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 883 Hiltner Method. — Proceed as under lemon extract (p. 877) weighing 12 grams of the oil, diluting to 100 cc, and using 2 cc. of this solution for the comparison. Determination of Total Aldehydes. — Proceed as under lemon extract (p. 875), using from 2 to 5 grams of the sample in 100 cc. of aldehyde- free alcohol. This method should be used on orange oils the aldehydes of which are not determined by the other methods, although valuable information as to the content of added citral in the oil can be obtained by use of the Hiltner method. Determination of Physical Constants of the Ten Per Cent Distillate. ScJmnmel df Co. Method. — Place 50 cc. of the sample in a 3-bulb Laden- burg flask in which the main bulb has a diameter of 6 cm. and is of 200 cc. capacity and which has the condensing bulbs of the following dimensions: 5.5 cm., 5 cm., 2.5 cm., and in which the distance from the bottom of the flask to the opening of the side arm is 20 cm. Distil the oil at the rate of 2 cc. per minute until 5 cc. have been distilled. Determine the refractive index and rotation of this distillate as directed above. Detection of Pinene. — Chace Method. — Mix the 10% distillate as obtained above with 5 cc. of glacial acetic acid, cool the mixture thoroughly in a freezing bath, and add 10 cc. of ethyl nitrite; then add slowly, with constant shaking, 2 cc. of a mixture of 2 parts concentrated hydrochloric acid and i part water which has been previously cooled. Keep this mixture in the freezing bath during this operation and allow it to remain therein for 15 minutes. Filter off the crystals formed, using vacuum and washing with strong alcohol. Return the filtrate and washings to the freezing bath and allow them to remain for 15 minutes. Filter off the crystals formed, using the original filter-paper. Wash the two crops of crystals thoroughly with alcohol. Dry at room temperature and dis- solve in the least possible amount of chloroform. Reprecipitate the nitroso- chloride crystals with methyl alcohol and mount for examination under the microscope with olive oil. Pinene nitroso-chloride crystals have irregular pyramidal ends while limonene nitroso-chloride crystallizes in needle forms. Determination of Alcohol.— The amount of alcohol present in oils which have been used for the manufacture of terpeneless extracts may be approximately determined by washing repeatedly with small portions of saturated sodium chloride solution and determining the alcohol in these washings in the usual way. ~OOD INSPECTION AND ANylLYSIS. ORANGE EXTRACT. Orange Oil is a yellowish liquid, having the characteristic odor of orange, and a mild aromatic taste. It is prepared from orange peel in an analogous manner to that of lemon oil, which it somewhat resembles in chemical composition. At least 90% of orange oil, according to Walach, consists of dextro-limonene (citrene). It has a much higher specific rotatory power than lemon oil. U. S. Standards. — Oil of Orange is the volatile oil obtained, by expression or alcoholic solution, from the fresh peel of the orange {Citrus aurantium L.) and has an optical rotation at 25° C. of not less than + 95° in a loo-mm. tube, Terpeneless Oil of Orange is oil of orange from which all or nearly all of the terpenes have been removed. Orange Extract is the flavoring extract prepared from oil of orange, or from orange peel, or both, and contains not less than 5% by volume of oil of orange. Terpeneless Extract of Orange is the flavoring extract prepared by shaking oil of orange with dilute alcohol, or by dissolving terpeneless oil of orange in dilute alcohol, and corresponds in flavoring strength to orange extract. Method of Analysis, — Orange oil and orange extract are analyzed by the same methods as lemon oil (p. 882) and lemon extract (p. 872). In the determination of orange oil by Mitchell's polariscopic method divide the direct reading on the Ventzke scale, calculated for the 200- mm. tube, by 5.3 to obtain the per cent of orange oil by volume. To obtain the per cent by weight, multiply the per cent by volume by 0.85 and divide by the specific gravity of the extract. ALMOND EXTRACT. Oil of Bitter Almonds is obtained by distilling crushed bitter almonds, peach seeds, or apricot seeds with water. It should be remembered that both sweet and bitter almonds yield a bland fixed oil on pressure, which is not to be confounded with the volatile oil yielded on distillation of the bitter almonds after the fixed oil has been pressed out. Bitter almonds contain a glucoside, amygdalin, together with a ferment known as emulsin or synaptase, which, acting on the amygdalin in the distillation, produces benzaldehyde and hydrocyanic acid as follows: FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 885 C20H27NO11 + 2H2O =- C^H^O + HCN f 2C6Hi20e. Amygdalin Benzalde- Hydro- Glucose hyde cyanic acid The unpurified oil of bitter almonds consists largely of benzaldehyde, with a small amount of the poisonous hydrocyanic acid. Nearly all of the commerical oil is made from the cheaper apricot and peach seeds rather than those of the bitter almond, but the product is practically identical. The oil is freed from hydrocyanic acid by agitating with calcium hydrate and a solution of ferrous chloride, distilling the mixture, and drying the oil which comes over with calcium chloride. Benzaldehyde constitutes 90 to 95 per cent of oil of bitter almonds, having a bitter, acrid, burning taste, and a marked almond odor. The specific gravity of the crude oil varies from 1.052 to 1.082, while that of the purified oil (benzaldehyde) at 20° is 1.0455. ^^s boiling-point is 180° C. On standing it becomes readily oxidizable to benzoic acid. It is readily soluble in alcohol and ether. Its solubihty in water is slight, 1:300. Its index of refraction at 20° C. is 1.5446. It should be noted that the refractive indices of almond oil, whether with or without hydro- cyanic acid, and of artificial benzaldehyde are nearly the same. Benzaldehyde is produced artificially in a variety of ways, but is chiefly prepared by the action of chlorine on hot toluene. The result- ing benzyl chloride is distilled with lead nitrate and water in an atmos- phere of carbon dioxide, which forms benzoic aldehyde. Synthetic benzaldehyde has the same properties as the purified oil of bitter almonds, and has largely displaced it in the market, not the least of its advantages being its freedom from hydrocyanic acid. Almond Extract. — Essence of bitter almonds, or Spiritus amygdala amarcE, is thus prepared according to the U. S. Pharmacopoeia: Oil of bitter almonds ic cc. Alcohol 800 cc. Distilled water sufficient to make 1000 cc. Thus 1% of almond oil is present in the product. U. S. Standards. — Oil of Bitter Almonds, commercial, is the volatile oil obtained from the seed of the bitter almond {Amygdaliis communis L.), the apricot {Prunus armeniaca L.), or the peach (Amygdalus persica L.). Almond Extract is the flavoring extract prepared from oil of bitter ■886 FOOD INSPECTION AND ANALYSIS. almonds, free from hydrocyanic acid, and contains not less than i% by volume of oil of bitter almonds. Adulteration of Almond Oil. — The official essence of the Pharma- copoeia does not specify that the almond oil used be perfectly free from hydrocyanic acid, in spite of the fact that its highly poisonous nature is well known, and that it exists in the crude oil to the extent of from 4 to 6 per cent. True, but little of it is found in the extract, but in these days, when the unannounced presence in foods of such substances as antiseptics and coloring matters is regarded as questionable from a sanitary stand- point, in spite of the fact that their toxic effects on man are still matters of controversy, there thould be little hesitancy in pronouncing the presence of prussic acid objectionable, especially when a pure almond oil entirely free from it is readily obtainable. The presence of nitrobenzol or oil of mirbane as a substitute of almond oil is to be looked for. This substance is sometimes, though incorrectly, called artificial oil of bitter almonds. It is a heavy, yellow liquid of the composition CgHgNOa, readily soluble in water. Its specific gravity at 20° C. is 1.2039. Its boiling-point is 205° C. It is formed by the action of nitric acid on benzol. It possesses a highly pungent odor, somewhat like that of oil of bitter almonds, though more penetrating and less refined. Its index of refraction at 20° C. is 1.5517. METHODS OF ANALYSIS OF ALMOND EXTRACT. Determination of Benzaldehyde. — Denis and Dunbar Method* — i. Reagent. — Mix 30 cc. of glacial acetic acid with 40 cc. of water, then pour in 2 cc. of phenyl hydrazine. The reagent should be made up immediately before use and discarded when more than an hour old. 2. Method. — Measure out two portions of 10 cc. each of the extract into 300-cc. Erlenmeyer flasks and add 10 cc. of the reagent to one flask and 15 cc. to the other. Shake, stopper tightly, and allow to stand in a dark place over night. Add 200 cc. of distilled water and filter the precipitate of hydrazone on a tared Gooch crucible provided with a thin coat of asbestos. Wash first with cold water, finally with 10 cc. of 10% alcohol, and dry for three hours in a vacuum-oven at 70° C, or to con- stant weight over sulphuric acid. The weight of the precipitate multi- plied by the factor 5.408, will give the weight of benzaldehyde in 100 cc. of the sample. If duplicate determinations do not agree, repeat the operations, using a larger quantity of the reagent. * Jour. Ind. Eng. Chem., i, 1909, p. 256, A. O. A. C. Method. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 887 Hortvet and West Method.'^ — Measure 10 cc. of the extract into a loo-cc. flask, add 10 cc. of a 10% sodium hydroxide solution, and 20 cc. of a 3% hydrogen peroxide sohition, cover with a watch-glass and place on a water-oven. Oxidation of the aldehyde to benzoic acid begins almost immediately and should be continued from five to ten minutes after all odor of benzaldehyde has disappeared, which usually requires from twenty to thirty minutes. If nitrobenzol be present, it will be indicated at this point by its odor. WTien the oxidation of the aldehyde is complete, remove the flask from the water-oven, transfer the contents to a separatory funnel, rinsing off the watch-glass, add 10 cc. of a 20% sulphuric acid solution, and cool the contents of the funnel to room temperature under the water tap. Extract the benzoic acid with three portions of 50, 30, and 20 cc. of ether, respectively, wash the combined extracts in another separatory funnel with two portions of from 25 to 30 cc. of distilled water, or until all the sulphuric acid is removed. Filter into a tared dish, wash with ether, allow to evaporate at room tempera- ture, and finally dry over night in a desiccator, and weigh. The per cent of benzaldehyde {B) is obtained from the weight of the acid (W) by the foUowing formula: ^ 0.869 X 10 XTF 1.045 If desired the benzoic acid may be titrated, and the benzaldehyde calculated from the amount of standard alkali required for neutraliza- tion. The process is as follows: Dissolve the benzoic acid obtained as above described, except that it need not be dried in a desiccator, in 95% alcohol made neutral to phenolphthalein with tenth-normal sodium hydroxide, dilute with an equal volume of water, and titrate with tenth- normal sodium hydroxide, using phenolphthalein as indicator. The per cent of benzaldehyde {B) is calculated from the cc. of tenth-normal alkali (F) by the following formula: FXo.oio6iXto 1.045 Detection of Nitrobenzol.t — Boil 15 cc. of the extract in a test-tube with a few drops of a strong solution of potassium hydroxide. Nitro- benzol produces a blood-red coloration. * Jour. Ind. Eng. Chem., i, 1909, p. 86. t Holde, Jour. Soc. Chem. Ind., 13, 1893, p. 906. 888 FOOD INSPECTION yIND yiN/i LYSIS. Distinction between Benzaldehyde and Nitrobenzol. — Treat 20 cc. of the extract with 5 to 10 cc. of a cold, saturated aqueous solution of sodium bisulphite in a test-tube, and shake vigorously. Transfer to an evaporating- dish, and heat on the water-bath till the alcohol is driven off. At this stage benzaldehyde remains in the hot solution as a crystal- line salt, and the solution gives off no almond odor. Nitrobenzol, on the contrary, does not combine wilh the bisulphite and is insoluble, forming globules of oil on the surface of the hot liquid, and in addition giving off the pungent odor so characteristic of the sub- s' ance. Separation of Nitrobenzol and Benzaldehyde. — If by the qualitative test nitrobenzol is found, shake vigorously as before 5c cc. of the extract with 10 cc. of the saturated sodium bisulphite solution in a corked flask, and transfer with 100 cc. of water to a large separately funnel. Shake out the nitrobenzol from the solution with four successive portions of petroleum ether of 15 to 20 cc. each, and after washing with water the combined petroleum ether, transfer it to a tared di^h, in which it is allowed to evaporate spontaneously. It is extremely difificult to avoid loss of some of the nitrobenzol by this process, but even if the weighed residue fails to shew the full amount originally used, enough will usually be extracted to admit of testing on the refractometer, and of otherwise verifying its character. After removal of the nitrobenzol, make the residual solution in the separatory funnel strongly alkaline with sodium hydroxide, and shake out the benzaldehyde, if present, with petroleum ether as previously described. If after making the solution alkaline no odor of benzalde- hyde is apparent, the absence of benzaldehyde may be inferred. Distinction between Artificial Benzaldehyde and Pure Almond Oil. — Test the final residue from the ether extract by shaking with an equal volume of concentrated sulphuric acid in a test-tube. With natural oil of almonds a clear, brilliant, but dark currant-red color is produced, while with artificial benzaldehyde,. the acid produces a dirty brown color with the formation of a precipitate. Determination of Alcohol. — In the absence of other flavoring sub- stances than nitrobenzol and benzaldehyde, which are rarely present to an extent exceeding 1%,, a sufficiently close approximation for most purposes can be gained by estimating the alcohol from the direct specific gravity of the extract. Detection of Hydrocyanic Acid. — To a few cubic centimeters of FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 889 extract in a test-tube add a few drops of a mixture of solutions of ferrous sulphate and ferric chloride, the ferrous salt being in excess. Make alkaline with sodium hydroxide, and add enough dilute hydrochloric acid to dissolve the precipitate formed by the alkali. Presence of a blue coloration or precipitate, due to the formation of Prussian blue, indicates hydrocyanic acid. The reaction is very delicate. Determination of Hydrocyanic Acid.* — Hydrocyanic acid may be determined by titration with tenth-normal silver nitrate solution. 25 cc. of the extract are measured into a flask, and 5 cc. of freshly prepared magnesium hydroxide suspended in water are added, or enough to make the reaction alkaline. A few drops of a solution of potassium chromate are then introduced, and the tenth-normal silver nitrate solution added till, with shaking, the formation of the red silver chromate indicates the end-point, i cc. of silver solution equals 0.0027 gram of hydrocyanic acid. WINTERGREEN EXTRACT. Wintergreen Oil. — True oil of wintergreen is obtained by distillation from the leaves of the wintergreen plant {Gaultheria procumbens L.). Gildermeister and Hoffman f state that the specific gravity at 15° is 1. 180 to 1.187, the boiling-point 218 to 221° C. It is slightly laevo- rotatory (a^,^— 0.0^25' to —1°). Oil of betula or sweet birch is distilled from the bark of the black birch {Betula lenta L.). It has the same specific gravity and boihng- point as oil of wintergreen, but unlike the latter is optically inactive. It differs somewhat from oil of wintergreen in taste and odor, but is hardly distinguishable in these respects from synthetic methyl salicylate. Both oil of wintergreen and oil of sweet birch consist almost entirely of methyl salicylate, the former containing, according to Power and Kleber,J as much as 99.8% of this substance. U. S. Standards. — Oil of Wintergreen is the volatile oil distilled from the leaves of the Gaultheria procumbens L. Wintergreen Extract is the flavoring extract prepared from oil of wintergreen, and contains not less than 3% by volume of oil of winter- green. * Vielhaber, Arch. Pharm. (3), 13, 408 t The Volatile Oils. Translated by Kreraers, Milwaukee, 1900, p. 588. X Pharm. Rund., 13, p. 228. Sgo FOOD INSPECTION AND ANALYSIS. Spirit of Gautheria of the U. S. P. is a mixture of 50 cc. of oil of wintergreen and 950 cc. of alcohol. It accordingly contains 5% by volume of the essential oil. Adulteration of Wintergreen Extract. — Synthetic methyl salicylate is very commonly substituted for both wintergreen and sweet birch oil, and sweet birch oil in turn for wintergreen oil. The production of true wintergreen oil is small, the so-called natural wintergreen oil of com- merce being usually sweet birch oil. The sense of smell is the best means of distinguishing the two oils; polarization is of rather uncertain value, owing to low rotatory power of the wintergreen oil. Determination of Wintergreen Oil. — Hortvet and West's Method* — Measure 10 cc. of the extract into a loo-cc. beaker, add 10 cc. of 10% potassium hydroxide solution, and heat the mixture over a boiling water- bath until the odor of oil of wintergreen has disappeared and the hquid is reduced to about one-half its original volume. By this treatment the methyl salicylate is converted into the potassium salt. Liberate the sahcylic acid by the addition of an excess of 10% hydrochloric acid, cool, and extract in a separatory funnel with three portions of 40, 30, and 20 cc. of ether respectively. Pour the combined ether extracts through a dry filter into a weighed dish, wash the filter with 10 cc. of ether, evaporate filtrate and washings slowly at 50° C, dry one hour in a desiccator, and weigh. The per cent of wintergreen oil by volume (M) is obtained from the weight of salicylic acid (S) by the following formula: 1.101X10X.S M= i.ii Howard's Method. — Proceed as described on page 874, except that the heavy oil is brought into the graduated portion of the Babcock bottle by addition of dilute sulphuric acid (1:2), taking care that the acid is not over 25° C. and avoiding agitation. PEPPERMINT EXTRACT Peppermint Oil is obtained from various plants of the genus Mentha, which are commonly classed as sub-species or varieties of M. piperita. Owing in large part to the botanical differences in the plants from which- * Jour. Ind. Eng. Chem., i, 1909, p. 90. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 891 it is made, peppermint oil from different regions differs greatly in its chemical and physical constants as shown by the following table com- piled from figures given by Gildermeister and Hoffmann:* Specific Gravity. Rotation, a D- Total Menthol. Per Cent. American English . . Japanese . Saxon . . . German . French . . Russian .. 0.905 to O.Q20 0.900 to 0.910 0.895 to 0.9C0 0.900 to 0.915 0.899 to 0-930 0.918 to 0.920 0.905 to 0.910 -18° to -33° -22° to —^T° ■30° to -42° -25° to —33° -27° to -33° - 5° to - 9° -17° to —22° 48 to 60 56 to 66 70 to 91 54 to 68 43 to 46 50.2 U. S. standards. — Peppermint is the leaves and flowering tops of Mentha piperita L. Oil of Peppermint is the volatile oil obtained from peppermint, and contains not less than 50% by weight of menthol. Peppermint Extract is the flavoring extract prepared from oil of pepper- mint, or from peppermint, or both, and contains not less than 3% by volume of oil of peppermint. Analysis of Peppermint Extract. — Owing to the wide variation in the rotatory power of peppermint oil, only a roughly approximate idea of the oil content of peppermint extract can be gained by polarization. The variation in the percentage of menthol in the oil is also too great to perm.it of a method based on the amount of this constituent. IMitchell's precipitation method, as originally described (page 873), does not effect a complete separation of the oil, but Howard's modification (page S74) gives satisfactory results, and is well adapted for purposes of inspection. SPEARMINT EXTRACT. U. S. Standards. — Spearmint is the leaves and flowering tops of Mentha spicata L. Oil of Spearmint is the volatile oil obtained from spearmint. Spearmint Extract is the flavoring extract prepared from oil of spear- mint, or from spearmint, or both, and contains not less than 3% by volume of oil of spearmint. * The Volatile Oils. Translated by Edward Kremers, Milwaukee, igoo. 892 FOOD INSPECTION AND ANALYSIS. SPICE EXTRACTS. Alcoholic solutions of the essential oils of spices are used to some extent instead of the spices themselves. The following are the definitions of these extracts and the oils from which they are prepared, as adopted by the joint committee on standards and the U. S. Secretary of Agri- culture : U. S. Standards. — Anise Extract is the flavoring extract prepared from oil of anise, and contains not less than 3% by volume of oil of anise. Oil of Anise is the volatile oil obtained from the anise seed. Celery Seed Extract is the flavoring extract prepared from celery seed or the oil of celery seed, or both, and contains not less than 0.3% by volume of oil of celery seed. Oil of Celery Seed is the volatile oil obtained from celery seed. Cassia Extract is the flavoring extract prepared from oil of cassia, and contains not less than 2% by volume of oil of cassia. Oil of Cassia is the lead-free volatile oil obtained from the leaves or bark of Cinnamomum cassia Bl., and contains not less than 75% by weight of cinnamic aldehyde. Cinnamon Extract is the flavoring extract prepared from oil of cinna- mon, and contains not less than 2% by volume of oil of cinnamon. Oil of Cinnamon is the lead-free volatile oil obtained from the bark of the Ceylon cinnamon {Cinnamomum zeylanicum Breyne), and contains not less than 65% by weight of cinnamic aldehyde and not more than 10% by weight of eugenol. Clove Extract is the flavoring extract prepared from oil of cloves, and contains not less than 2% by volume of oil of cloves. Oil of Cloves is the lead-free, volatile oil obtained from cloves. Ginger Extract is the flavoring extract prepared from ginger, and contains in each 100 cc. the alcohol-soluble matters from not less than 20 grams of ginger. Nutmeg Extract is the flavoring extract prepared from oil of nutmeg, and contains not less than 2% by volume of oil of nutmeg. Oil of Nutmeg is the volatile oil obtained from nutmegs. Savory Extract is the flavoring extract prepared from oil of savory, or from savory, or both, and contains not less than 0.35% by volume of oil of savory. Oil of Savory is the volatile oil obtained from savory. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 893 Star Anise Extract is the flavoring extract prepared from oil of star ^nise, and contains not less than 3% by volume of oil of star anise. Oil of Star Anise is the volatile oil distilled from the fruit of the star anise {Illicium veruni Hook). Sweet Basil Extract is the flavoring extract prepared from oil of sweet basil, or from sweet basil, or both, and contains not less than 0.1% by volume of oil of sweet basil. Sweet Basil, Basil, is the leaves and tops of Ocymum basilicum L. Oil of Sweet Basil is the volatile oil obtained from basil. Sweet Marjoram Extract, Marjoram Extract, is the flavoring extract prepared from the oil of marjoram, or from marjoram, or both, and con- tains not less than i*^'^ by volume of oil of marjoram. Oil of Marjoram is the volatile oil obtained from marjoram. Thyme Extract is the flavoring extract prepared from oil of thyme, or from thyme, or both, and contains not less than 0.2% by volume of oil of thyme. Oil of Thyme is the volatile oil obtained from thyme. Determination of Essential Oil in Cinnamon, Cassia, and Clove Extracts. — Howard's Method. — Proceed as with wintergreen extract, page 890. Hortvet and West's Method.* — Place 10 cc. of the extract and 50 cc. of water in a separatory funnel, and extract with three portions of ether measuring respectively 50, 30, and 20 cc. Wash the combined extracts successively with 25 and 30 cc. of distilled water, and filter through a dry funnel into a wide-mouth flask, washing out the funnel and filter with a httle ether. In the case of cinnamon extract, transfer the ether extract before filtering to a 150-cc. flask, shake for a few minutes with some granulated calcium chloride, then filter in the manner described. Evaporate oft' the ether as rapidly as possible on a boiling water-bath until only a few drops remain. At this point remove the flask from the bath, and rotate rapidly for a few minutes, spreading the residue over the sidec of the flask. The rapid evaporation of the remaining ether cools the flask to near room temperature. When the odor of ether has dis- appeared, stopper the flask and weigh. In the case of cassia and clove oils, where the ether extract is not first dried with calcium chloride, a shght cloudiness gathers on the flask as the last traces of ether disappear, due to the presence of a little moisture. In such case allow the flask to stand on the balance-pan * Jour. Ind. Eng. Chera., i, igog, p. 88. 894 FOOD INSPECTION JND ANALYSIS.^ until the film disappears, requiring not longer than two to three minutes, then stopper, and weigh. ;^ The per cent of oil by volume (F) is calculated from the weight of oil {W) by the following formula: looXW V= loX 1.050 The oil thus extracted may be used for determination of the refractive Index. After dissolving in a little alcohol it may be tested with ferric chloride solution. By this test cinnamon oil gives a green, cassia oil a brown, and clove oil a deep blue, coloration. Determination of Essential Oil in Nutmeg Extract. — Follow Mitchell's precipitation method, page 873. Determination of Solids in Ginger Extract.* — Evaporate 10 cc. on a boiling water-bath to dryness, dry for 2 hours in a boiling water oven and weigh. Determination of Alcohol in Ginger Extract.* — Proceed as with vanilla extract (p. 869). Detection of Ginger in Ginger Extract.* — Seeker Method. — Dilute 10 cc. of the extract to 30 cc, evaporate off 20 cc, decant into a separatory funnel and extract with an equal volume of ether. Evaporate the ether spontaneously in a porcelain dish and to the residue add 5 cc. of 75% sulphuric acid and 5 mg. of vanillin. Allow to stand for 15 minutes and add an equal volume of water. In the presence of ginger extract an azure blue color develops. Detection of Capsicum in Ginger Extract. — La Wall Method Modified by Doyle.-\ — To 10 cc. of the extract cautiously add dilute sodium hydroxide until the solution reacts very shghtly alkahne with htmus paper. Evapor- ate at about 70° C. to about one-quarter of the original volume, render slightly acid with dilute sulphuric acid, testing with litmus paper. Trans- fer to a separatory funnel, rinsing the evaporating dish with water, and extract with an equal volume of ether, avoiding emulsification by shak- ing the funnel gently for a minute or two. Draw off the lower layer and wash the ether extract once with about 10 cc. of water. Transfer the washed ether extract to a small evaporating dish, render decidedly alkaline with alcoholic potassium hydroxide, and evaporate at about 70° until * A.O.A.C. Method, Proc. for 1910, U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 75. t A.O.A.C. Method, Proc. for 191 1, Bui. 152, p. 145. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 895 the residue is pasty; then add about 20 cc. more of half -normal alcoholic potash and allow to stand on a steam bath until the gingerol is com- pletely saponified, which usually requires about one-half hour. Dis- solve the residue in a little water and transfer with water to a small sepa- ratory funnel. The volume should not exceed 50 cc. Extract the alkaline solution with an equal volume of ether. Wash the ether extract repeatedly with small amounts of water until no longer alkaline to litmus. Transfer the washed extract to a small evaporating dish, allow the ether to evaporate spontaneously, and finally, iest the residue for capsicum by moistening the tip of the finger, rubbing it around on the bottom and sides of the dish, and then applying the finger to the end of the tongue. A hot, stinging, or prickly sensation, which persists for several minutes, indicates capsicum or other foreign pungent substances. ROSE EXTRACT. U. S, Standards. — Rose Extract is the flavoring extract prepared from otto of roses, with or without red rose petals, and contains not less than 0.4% by volume of otto of roses. Otto of Roses is the volatile oil obtained from the petals of Rosa damascena Mill., R. centifolia L., or R. moschata L. Determination of Rose Oil. — Horlvct and West's Method.'^ — Measure 25 cc. of the extract into a separatory funnel, add 50 cc. of water, mix thoroughly, acidify with i cc, of hydrochloric acid (1:1), and extract with three portions of 20 cc. each of ether. Transfer the combined ether extracts to a 150-cc. flask, shake for a few minutes with some granulated calcium chloride, allow to settle until clear, then decant through a dry filter into a flat bottom glass dish previously weighed together with a cover-glass. Wash the calcium chloride and filter twice with 10 cc. of ether, and add the washings to the glass dish. Cover the dish, place in a vacuum desiccator over sulphuric acid, allow to remain until all traces of ether and alcohol are removed, and weigh. Repeat the drying in the desiccator, for one hour periods, until the weight is practically constant. The final weight, divided by 0.86 and multiplied by 5, gives the per cent of oil of rose by volume. IMITATION FRUIT FLAVORS. Nearly all the fruits possess distinctive flavors, which are desirable in food [preparations, and which may be made to impart their flavor to * Jour. Ind. Eng. Chem., i, 1909, p. 89. 896 FOOD INSPECTION AND ANALYSIS. such substances as confections, ice cream, dessert mixtures, jellies, etc., by simply mixing with these foods the fresh or preserved fruit or fruit juice in sufficient quantity. In many cases, however, it is not found possible or practicable to prepare from the fruits themselves an extract sufficiently concentrated to give the distinctive fruit flavor, when used in moderate quantity, and hence the use of artificial fruit essences made up of compound ethers, mixed in varying combinations and proportions to imitate more or less closely various fruit flavors. These ethers are usually much more pungent and penetrating than the fruits which they imitate, and, while lacking the delicacy and refine- ment of the original fruits, serve to impart a certain semblance of the genuine flavor in a convenient and highly concentrated form. Some of the single compound ethers possess a remarkable resemblance to particular fruits, while to imitate other fruits a mixture of various ethers and flavoring materials, such as lemon and other volatile oils, vanilla, organic acids, chloroform, etc., is necessary. These artiricial essences should in all cases be sold as such, and not as "pure fruit flavors." Imitation Pineapple Essence is made up by dissolving in alcohol butyric ether, €4117(02115)02, which possesses a disLinct pineapple flavor, and is prepared by mixing 100 par:s of butyric acid (C4H8O2), 100 par.s of alcohol, and 50 parts of sulphuric acid, and shaking. Butyric ether is sparingly soluble in water, and boils at 121° C. Imitation Quince Essence depends as a basis on ethyl pelargonate, sometimes called pelargonic or oenanlhic ether, C2H5,C9Hi702, dissolved in alcohol. Pelargonic ether is formed by digestion with the aid of heat of pelargonic acid and alcohol. Pelargonic acid, CaHjg02, is first obtained by the action of nitric acid on oil of rue. Pelargonic ether is a colorless liquid, having a specific gravity of 0.8635 at 17.5° C. Its boiling-point is 227° to 228° C. It is"" insoluble in water. Imitation Jargonelle Pear Essence consists of an alcoholic solution of amyl or pentyl acetate, QHii,C2H302. This is prepared by distilling a mixture of one part of amyl alcohol, two parts of potassium acetate, and one part of concentrated sulphuric acid. It is a colorless liquid, insoluble in water, and having a boiling-point of 137° C. Imitation Banana Essence is made up of a mixture of amyl acetate and butyric ether. Imitation Apple Essence is composed of an alcoholic solution of amyl valerianate, sometimes called apple oil, C5Hii,C5H902, prepared by mixing four parts of amyl alcohol with four of sulphuric acid, and adding FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 897 COMPOSITION OF IMITATION ESSENCES. 3. u 2 3 s •s < <5 u . cu *^ 1- caxi c *^ (U — 0" rt.g Pineapple Melon I I I I 2 2 2 5 4 5 I 5 j i 10 5 5 5 I 5 5 10 ID 5 5 I I I Strawberry I I I Raspberry I I I I 10 ..... I I Gooseberry Grape 2 I 2 I 2 I 1 I Apple I I 5 5 Orange I Pear I 2 4 s I Lemon Black cherry. . . . I I 2 Plum. ...: 5 I 2 10 5 Apricot I 5 5 ' I Peach 2 I 5 5 5 Currant. I I c < a < OJ 'B < "S 1" d to c 6 Saturated Alcholic Solutions of aj-d Oxalic Acid. Succinic Acid. c d •n I 5 Pineapple 10 1 3 3 Melon 1 Strawberry 3 I 2 I Raspberry 5 5 5 \"V' 1 I -> I 4 Gooseberry Grape Apple ID ^ 4 Orange I 2 10 I Pear Lemon 10 10 I I 2 I Black cherry :> Cherry 3 8 Plum Apricot 2 2 I I 4 5 Peach Currant 5 \ I 898 FOOD INSPECTION AND ANALYSIS. the mixture when cold to five parts of valerianic acid. The specific gravity of amyl valerianate is 0.879 at 0° C. and its boiling-point is 188° C. The table on p. 897, prepared by Kletzinsky, shows the composition of a large variety of these artificial essences. The numerals in the various columns indicate the parts by volume to be added to 100 parts of deodor- ized alcohol. Determination of Esters. — Add to 25 grams of the extract 2 cc. of sodium hydroxide solution (100 grams in 100 cc. of water), 100 cc. of water and heat under a reflux condenser one half-hour. Acidify with 5 cc. of dilute sulphuric acid (1:4), add a few pieces of pumice stone, distil in a current of steam and titrate the distillate with tenth-normal alkali, using phenophthalein as indicator. The number of cc. required represents the total volatile acids free and combined. Determine free volatile acids, if present by direct distillation and titration of the distillate. The difference between the two titrations is calculated as ethyl acetate. REFERENCES ON FLAVORING EXTRACTS. Chace, E. M. a Method for the Determination of Citral in Lemon Oils and Extracts. Jour. Am. Chem. Soc, 28, 1906, p. 1472. The Detection of Small Quantities of Turpentine in Lemon Oil. Ibid., 30, 1908, P- 1475- Denis, W., and Dunbar, P. B. The Determination of Benzaldehyde in Almond Flavoring Extract. Jour. Ind. Eng. Chem., i, 1909, p. 256. GiLDEMEiSTER, E., and Hoffmann, F. The Volatile Oils. Trans, by Edward Kremer. Milwaukee, 1900. Hess, W. H. The Distinction of True Extract of Vanilla from Liquid Preparations of Vanillin. Jour. Am. Chem. Soc, 21, 1899, p. 719. Hess, W. H., and Prescott, A. B. Coumarin and Vanillin, their Separation, Estima- tion and Identification in Commercial Flavoring Extracts. Jour. Am. Chem. Soc, 21, 1899, p. 256. Heusler, F. The Chemistry of the Terpenes. Trans, by F. J. Pond. Philadelphia, 1902. Hiltner, R. S. The Determination of Citral in Lemon Extract. A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 34. Jour. Ind. Eng. Chem., I, 1909, p. 798. Hortvet, J., and West, R. M. The Determination of Essential Oils and Alcohol in Flavoring Extracts. Jour. Ind. Eng. Chem., i, 1909, p. 84. Howard, C. D. The Precipitation Method for the Estimation of Oils in Flavoring Extracts and Pharmaceutical Preparations. Jour. Am. Chem. Soc, 30, 1908, p. 608. FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 899 Mitchell, A. S. Lemon Flavoring Extract and its Substitutes. Jour. Am. Chem. Soc, 21, 1899, p. 1132. Flavoring Extracts. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 69. WiNTON, A. L., and Silverman, M. The Analysis of Vanilla Extract. Jour. Am. Chem. Soc, 24, 1902, p. 11 29. WiNTON, A. L., and Bailey, E. M. The Determination of Vanillin, Coumarin, and Acetanilide in Vanilla Extract. Jour. Am. Chem. Soc, 27, 1905, p. 719. WiNTON, A. L., and Lott, C. I. Distinction of Vanilla Extract and its Imitations. U. S. Dept. of Agric, Bur. of Chem., Bui. 1.32, p. 109. CHAPTER XXI. VEGETABLE AND FRUIT PRODUCTS. CANNED VEGETABLES AND FRUITS. Strictly speaking all varieties of canned foods found in the marketj^. whether meats, fruits, or vegetables, in order to be entirely beyond criti- cism, should not differ from the corresponding freshly cooked varieties which they are intended to replace, excepting that they are free from bacteria. Such a degree of perfection is, however, difficult, even if pos- sible, to attain, and nearly all commercial canned products, even if made from the best materials, are liable to contain either antiseptic substances- or coloring-matter intentionally added by the manufacturer, or metallic impurities accidentally derived from the vessels in which they are pre- pared, or from the containers in which they are sealed. In spite of these objections, canned foods form a convenient, and in some cases indispensa- ble means of furnishing both necessities and luxuries for the table. The canning of foods is especially useful for preserving them during long periods of time, for enabling certain fruits and vegetables to be enjoyed out of season, and for furnishing supplies in a convenient manner to inac- cessible places where fresh foods are not readily obtainable, as in the case of armies in the field, of vessels at sea, of campers in the woods, etc.. Canned goods in great variety are used in nearly every household. When it is considered that in the United States alone something like one hundred million cans of corn are packed in a single year, about the same quantity of peas, and one hundred and fifty million cans of tomatoes, to say nothing of an ever-increasing variety of other foods, some idea may be gained of the enormous proportions to which the canning industry has grown. It is comforting to know that, in view of their wide-spread consumption, the greater portion of such foods found on the market are comparatively harmless, as is evidenced by the fact that few cases of injury to health have been directly traceable to their use. Method of Canning Food. — Various modifications as to details exist with different products and in different locahties, but in general the prin- 900 y EG STABLE AND ERUIT PRODUCTS. got ciple of canning in tin is the same in all cases. The fresh product is cleaned carefully, and packed in cans with the requisite amount of water. The cans are then sealed, and subjected to the effect of steam or boiling; water till the contents are thoroughly cooked. Each can is then tapped or punctured at one end to expel the air, and again heated, after which the hole is closed by a lump of solder, thus forming a vacuum in the can,, which is afterwards heated for a sufficient time to destroy the bacteria, usually for several hours. The above mode of procedure is the time-honored one, and is still in vogue in most localities, but a more modern method, much in use at present, consists in first cooking the food at a temperature of 82° to 88° C. before transferring to the cans, and afterwards subjecting the cans when sealed to a high heat of about 125° C. in dry air in so-called retorts, this heating or "processing," as it is termed, being carried on for a sufficient length of time to completely sterilize the contents of the can. Obviously a much shorter time is required for this than when the temperature of boiling water is employed, and the sterilization is much more effective. Cooked vegetables and fruit products put up in glass jars or bottles are tightly sealed when hoi, cither with screw-caps or with some form of cover held by a clamp, or with metal or hard-rubber caps fitting over a flanged mouth. Frequently a soft-rubber ring is inserted between the cover and the mouth of the jar or bottle. The material of the cover is generally either glass, porcelain, or metal. Cork stoppers are, however, sometimes pressed into the mouths of the bottles, and made extra tight, therein with sealing-wax. These stoppers are occasionally soaked in paraffin. Thus the contents of the jar may be exposed to porcelain, glass, metal, rubber, or cork, according to the material of the cover and the method of sealing. The preservation of food by canning was long thought to be due to the perfect exclusion of air, but is now known to depend on the perfect sterilization, or destruction of bacteria, and it has been proved that as far as keeping qualities are concerned, it makes no difference whether or not air is present in the can, if the contents are sterile, though for pur- poses of inspection the vacuum, in the case of tin cans, is of great use, in that as a natural consequence of the vacuum, when the goods gire sound, the ends of the cans are usually concave. The highest aim of the canner should be to retain in his product as far as possible the appearance, palatabiHty, and nutritive value of the freshly cooked food. go 2 FOOD inspect: CN AND ANALYSIS. PROXIMATE COMPOSITION OF CANNED VEGETABLES AND FRUITS* > c O CD ii (D r^-P*^ . ^< ^ « ^^^ i^ < 3 92-5 .8 ... 5-0 .6 ^-7 14 94-4 T-5 I 2 8 5 1.2 21 68.9 6.9 2 5 19 2 5 2.1 29 93-7 I.I I 3 8 5 1-3 i6 79-5 4.0 3 14 t. I 2 1.6 I 93-7 1-5 I 3 4 5 1-3 52 76.1 2.8 I 2 19 8 -9 88 85-3 3-6 2 9 8 I 2 I.I 7 91.6 .8 2 6 7 I I -7 5 87.6 ■ 9 5 10 5 7 .5 12 75-9 3.6 I 18 9 .9 19 94.0 1.2 ' 4 5 .6 42-4 6r.i .3 2 .2 4 8 54-4 37-2 17-3 56.4 12.8 .5 -7 .4 .7 • 4 8r.4 40.0 85.6 77-2 88 I .9 ... .8 2 I I 3 .6 6 I . I I 21. I •5 • 3 •3 .7 -5 3 4 •7 •3 .4 .7 ... 10.8 81 I 3 7 18.0 61.8 36-4 24.0 I 74-8 no 85 600 95 360 95 455 255 150 235 455 105 1,120 730 340 1)15° 275 415 220 355 715 460 *U. S. Dept. of Agric, Exp. Sta. Bui. 2S, p. 70, DECOMPOSITION. Nature and Detection of Spoilage. — In the case of canned vegetables and fruit products, decomposition rarely results in the formation of ptomaines even after the can has long been open, though these toxins are sometimes formed in canned meat and fish. Decomposition is readily apparent after opening a can, from a cursory examination of its contents. The appearance, taste, and odor will not fail to indicate the unfitness of the contents for food, if decomposition is at all advanced. It is, how- ever, often of great advantage to detect spoiled cans without opening. As a rule, when a can is spoiled, it is usually in the condition termed <' blown," i.e., with its ends convex, instead of normal or concave. According to Prescott and Underwood, f although nearly all forms of bacterial decomposition are accompanied by bulging of the ends of the cans, there are some exceptions. In the souring of canned sweet com, J t Tech. Quart., 11, 1898, pp. 6-30; also 10, 1897, p. 183. X These experimenters found at least twelve varieites of bacteria to which the senriag of corn is apparently due. VEGETABLE AND FRUIT PRODUCTS. 903 for instance, it is exceptional that swelling occurs. Ordinarily, in the factory inspection of canned goods before shipping, not only are the bulged cans or " swells," as they are termed, sifted out, but the condition of the cans is tested by sounding or striking the cans. If the contents are sweet, a peculiar note is produced when the can is struck, readily distinguish- able from the dull tone of the unsound can byanyone familiar with the work. As stated above, concavity in the ends of the can indicates that the contents are in good condition. Prescott and Underwood further state that sound cans may be dis- tinguished from unsound in a lot of suspicious goods, when the swelling of the ends is not apparent, by the following method : Boil the cans for an hour, causing the ends of all to swell, then cool, and set aside for eight hours, during which the sound cans will snap back, while the unsound will continue convex, by reason of the fact that the swell- ing in this case is due to the generation of gas by the bacteria present. Examination of Gases from Spoiled Cans. — When the tops of blown cans are punctured in the process of opening, an outflow of gas is usually to be noted. Doremus * has studied the character of these gases and Fig. 118. — Apparatus for Collecting Gases from Spoiled Cans. (After Doremus.) found that when the contents have become putrid, carbon dioxide and hydrogen are the chief gases to be found. Often 60 to 80 cc. of gas may be collected from a can. For the collection of the gases, Doremus * Jour. Am. Chem. Soc., 19, 1897, p. 733. 904 FOOD INSPECTION y4ND ANALYSIS. uses the device shown in Fig. 118. An adjustable clamp has attached- to its upper arm a beveled, hollow, steel needle. A perforated rubber stopper covers the needle and serves as a cushion. A fine tube connects the needle with the receiver of a eudiometer, both tube and receiver being filled with water or mercury. Either the stop-cock form of eudiometer, as here shown, or the kind with attached leveling-tube may be used. The can is adjusted between the arms of the clamp, and by turning the screw the needle is brought into contact with the top of the can and caused to puncture it, the rubber stopper serving to make a gas-tight joint. The gas passes through the tube into the eudiometer, and its constituents are determined in the usual manner,, either by introducing the reagents directly into the eudiometer-tube in the proper order, or by transferring the gases to pipettes.* Hydrogen sulphide is tested for by subjecting a filter-paper moistened with lead acetate solution to the gas. If it turns black, the presence of hydrogen sulphide is indicated. METALLIC IMPURITIES. Salts of Lead and Tin are commonly met with in varying amounts in nearly all classes of products put up in tin. The quantity dissolved depends largely on the character of the tin plate used in the manufacture of the can, as well as on how the solder is applied. Much depends also on the nature of the food product and its acidity. Formerly much danger was apprehended from the use of the so-called terne plate as a material for cans. This consists of an alloy of lead and tin, coated on iron plate and intended for use as roofing. Sometimes two parts of lead to one part of tin are found in terne plate. Only the better grades of bright tin plate should be used in canning. There is reason to believe that no terne plate is at present used in cans. In 1892 the plating alloy of 47 samples of tin cans in which peas had been put up were examined in the Bureau of Chemistry of the U. S. Department of Agriculture, f and the amount of lead found varied from o to 13 per cent. Only 4 samples were found to exceed 5 per cent, and 24 contained less than i per cent. The construction of the can should be such that practically no soldered surface is exposed to the contents, the joints being lapped and soldered on the outside. In spite of this, however, it is not unusual to find cans * See Thorpe's Dictionary of App'd Chem., Vol. i, pp. 232-243. t Bui. 13, p. 1036. l^EGET^BLE AND FRUIT PRODUCTS. 905 soldered on the inside, or lumps of solder in the can from the sealing of the tapped hole. From 51 to 65% of lead was found in the solder taken from the interior of twenty-four of the cans mentioned in the preceding paragraph.* Cans lacquered on the inside to prevent contact of the metal with the food are coming into use but as yet are not an unqualified success. Some of the lacquers which have proved most efficient are objectionable because of their lead content. Action of Fruits and Vegetables on Tin Plate. — A large variety of canned products have been examined in the laboratory of the Massachu- FlG. 119. —Interior of Blueberry Cans, Cut Open to Show the Corrosion by Acid of the Fruit Juice. setts State Board of Health, with a view to determining the quantity of tin contained in solution. The results have shown that though notable traces of tin were found in acid f raits and rhubarb, and large traces in some green vegetables, canned blueberries were found to contain, as a rule, much more tin in solution than any other canned goods examined. It is assumed that the tin was, at least in considerable part, still held in solution by the fruit acids, inasmuch as the metal was found in the filtered juice. In every instance the inner tin lining was found to be exten- sively corroded, and in some cases it had been almost entirely dis- solved off, leaving the underlying iron bare. Fig. 119 shows the appear- * Bui. 13, p. 1038. 9o6 FOOD INSPECTION /tND ANALYSIS. ance of two of these cans, split open to show the inner surfaces. The corrosion is apparent. Eleven samples of canned blueberries, represent- ing seven brands, were examined in 1894 by Worcester, showing an amount of tin in solution (calculated as SnOj) varying from 0.066 to 0.27 gram per can of 615 cc. capacity. In 1899 samples of various canned products were examined for lead and tin in the author's laboratory, the results of which are thus summar- ized : * Strawberries. Highest. . . Lowest. . . . Raspberries. . Highest. . . Lowest. . . . Bhieberries. . Highest. . . Lowest. . . . Tomatoes . . . Highest. . . Lowest. . . . String beans. Highest. . . Lowest. . . . Peas Highest. . . Lowest. . . . Corn Highest. . . Lowest. . . . Lima beans. . Succotash. . . Squash Highest. . . Lowest. . . . Pumpkin Rhubarb. Asparagus . . . Mutton broth Tomato soup Salmon Lobster Tin, Grams. Lead, Grams. 0393 0124 0848 0725 2226 0056 0515 0146 0499 006'^ 0046 0024 OIOI 0045 0064 0039 1793 1577 1844 3506 1249 0114 0023 0319 04 1 1 .0004 .0000 .0002 .0001 .0021 .0004 .0004 .0001 . 0003 .0008 .GOOD .0001 .0011 .0001 .0004 .0001 .0087 .0003 .0019 .0002 .0001 .0001 .0002 .0001 .0001 Capacity of Can, cc. 615 615 61S 950 650 61S 615 650 650 950 950 615 930 950 470 430 A wide range of variation exists in the amount of tin dissolved. Pumpkin and squash, for example, dissolve surprisingly large quantities. considering the supposed inert nature of these vegetables. In samples of canned sardines put up in mustard, vinegar, and oil, the Massachusetts Board has found as high as 0.376 gram of tin in a * An. Rep. Mass. State Board of Health, 1899, p. 623. VEGETABLE AND FRUIT PRODUCTS. 907 half-pound can. In these cases the corrosion of the interior of the cans was very marked.* Effect of Time on Amount of Tin Dissolved. — h series of experi- ments was conducted by the author in 1899 f on the action of various fruit acids on tin, with a view to ascertaijiing, among other facts, whether or not the element of time exerts an appreciable difference in the results. Samples of various canned fruits and vegetables were titrated for their acidity. It was found that certain samples of canned blueberries, for instance, had an r^xidity of about one-twentieth normal. In the case of strawberries, the acidity was about one-sixth normal. Canned rasp- berries were found to be about one-tenth normal in acidity, while the acidity of canned tomatoes varied from one-tenth to one-fourteenth normal. Solutions of one-fifth, one-tenth, and one-fifteenth-normal malic acid, one-tenth and one-fifteenth-normal tartaric acid, one-tenth and one- fifteenth- normal citric acid, and one-tenth-normal acetic acid were prepared and sealed in pint glass jars, having about the same capacity as the ordinary-sized tin fruit cans, each jar containing an amount of tin plate equivalent to the interior exposed surface of a can. Solutions thus sealed were kept for three months, six months, and a year, and examined at the end of these respective periods for tin. The results showing the amount of tin found at the end of three months in each case are given in the following list: ACTION OF FRUJT ACIDS ON TIN IN THREE MONTHS. Acid. Grams of Tin in One Pint of Solution. Acid. Grams of Tin in One Pint of Solution. 0.0578 0.0201 0.0197 0.0382 N/15 tartaric 0.0246 N/io " N/io citric 0.0374 O.C236 0.0019 ■NI/tc " N/15 " N/io acetic It was found that, as a rule, the amount dissolved in three months was the same as in six months or even a year. Tenth-normal acetic acid sealed in jars with tin plate, as in the case of the fruit acids, dissolved in three months 0.0019 gram, and in six months * The U. S. Government, pending further investigation, permits 300^mg. of tin per kilo in canned goods. F. I. D. No. 126. t Ann. Rep. Mass. State Board of Health, 1899, p. 624. 9o8 FOOD INSPECTION AND AN /I LYSIS. 0.0083 gram of tin, which is much less than was obtained with fruit acids of the same strength, and with the samples of sardines referred to on page 906. Bigelow and Bacon find that shrimps contain monomethylamin, which corrodes the cans in which they are packed. Their experiments with volatile alkalis and amino acids present in vegetables of low acidity indicate that the corrosive action of certain vegetables is due to substances of this group. Salts of Lead. — While it is a fact that the material of the tin plating usually found in cans is comparatively low in lead, the same is not always true of the metal caps used to cover some of the bottled goods. The French "haricots verts "are usually sold in wide-mouthed bottles, closed by a disk of very soft metal. In one instance this metal cap, which came in contact with the liquid contents of the bottle, was found to contain 932% of lead. Of the various kinds of bottles in which are sold cheap carbonated drinks known as "pop," one style has a stopper consisting of a metallic button surrounded by a rubber ring. These metallic buttons consist of tin and lead in varying proportions. Inasmuch as the inclosed liquor was usually found to be quite acid in reaction, the danger of pro- longed contact with the metallic portion of the stopper is evident. The following table gives the percentage of lead found in the stoppers of this character, together with the amount of lead contained in the liquor:* Character of Sample. Per Cent of Lead in Stopper. Amount of Lead in Contents of Bottle in Milli- grams. t Blood orange 50.7 35 -o 32.2 8.8 6-5 8-5 3-5 7-5 50-3 3-8 0-31 Large trace 0.40 0.20 0.30 0.19 0.17 0.27 1.05 O.OI Birch beer Ginger Strawberry A Strawberry B Sarsaparilla A Sarsaparilla B Lemon Miscellaneous (20 samples) Maximum Minimum t Capacity of bottle about i pint. Besides the above tabulated samples, twenty were found with stoppers containing less than 3% of lead. While the amount of lead found in the * An. Rep. Mass. State Board of Health, 1897, p. 571. [VEGET/IBLE /1ND FRUIT PRODUCTS. 909 contents of the bottles was in no case very large, it was enough to con- demn the use of lead in the manufacture of such stoppers. That the amounts of lead found in the contents of the bottles vary quite irre spective of the percentage of lead in their stoppers, may be ascribed ta various causes, such as the difference in the acidity of the liquors, and the length of time that the liquor has been in contact with the stopper. Furthermore, the more soluble metal of an alloy is attacked by an acid with an energy which is not proportional to the percentage of that metal in the alloy. Salts of Zinc. — The presence of zinc salts in canned foods is largely accidental, and is generally due either to the contact of the acid fruits and vegetables with galvanized iron in the canneries, to the occasional use of brass vessels, or to the zinc chloride used as a soldering fluid- Hilgard and Colby * have examined empty tin cans fresh from the manu- facturer, and found zinc chloride in notable quantity in the seams, and especially in the empty space of the lap at the bottom of the can, where it could easily be acted on by the contents. The average amount of soluble zinc chloride found in the "lap" alone amounted to three-fourths of a grain per can. It was furthermore ascertained that it was not the practice of canners to wash the cans before packing, so that zinc present in canned goods may thus readily be accounted for. Zinc chloride is commonly used in machine soldering, but should be displaced by rosin. Hilgard and Colby found in some spoiled cans of asparagus, where the acidity was unusually high, an average of 6.3 grains of zinc chloride per large can. Zinc salts are said to have been used for greening peas, but their use for this purpose is not common. Zinc chloride is the salt used, and a. natural yellowish-green tint is imparted when properly applied. The process has been kept secret. Salts of Copper. — While copper in canned goods is sometimes acci- dental, its presence being due to the use of copper or brass vessels in the canneries, its chief interest to the food analyst lies in the use of copper sulphate for greening peas and other vegetables. The artificial greening of vegetables is much more commonly practiced in France than in the United States. French canners of peas, beans, Brussels sprouts, etc., are frequently so lavish in the use of sulphate of copper that the goods as found on our * Rep. Cal. Agric. Exp. Sta., 1897-8, p. 159. 9IO FOOD INSPECTION AND ANALYSIS. markets can in some cases hardly be said to resemble the freshly cooked products in color. Oftentimes, indeed, they possess such a deep green as to be positively distasteful to the average American palate, though evidently this unnatural hue is craved in Europe. The use of copper in such foods is often rendered apparent by the most cursory examina- tion. In this country, when copper is used, smaller quantities are usually employed, with an attempt to imitate more closely the color of the natural product. Complaint in court for this form of adulteration under the general food law as it exists in most states would naturally be brought under one ■of two clauses : ist. As being colored, whereby the product appears of greater value than it really is, or 2d. As containing an ingredient injurious to health. An ingenious claim is sometimes advanced by the defendant in oppo- sition to clause i, to the effect that copper sulphate is added, not to give an artificial green color, but to preserve the original green of the chloro- phyl or natural color of the fresh peas,* so that it will not be destroyed by subsequent boiling. This point was argued in a strongly contested court case brought in Massachusetts for copper in French peas.y As Worcester % has shown, the fallacy of this argument can be easily demonstrated. If it were true that the copper acts as a preservative of the chlorophyl, a pure extract of chlorophyl should, by the addition of •copper sulphate, be prevented from destruction on boiling, and again, •on once destroying the color of the chlorophyl by boiling, it would be impossible to restore it by further boiling it with copper sulphate. As a matter of fact, if an extract of chlorophyl is boiled with a dilute solution of copper sulphate, its color is at once destroyed, and a brown precipitate is thrown down. On the other hand, if yellow or white peas or beans devoid of chlorophyl are boiled with copper sulphate, they are colored green, the depth of color depending on the strength of the copper solution. When peas or other vegetables are thus colored, very little copper is found, as a rule, in the liquid contents of the can, but the copper is chiefly confined to the solid portions. Green compounds are produced * The term used by the French to describe this process is reverdissage or "regreening."^ t An. Rep. Mass. State Board of Heahh, 1892, p. 605. X Loc cit., supra, p. 641. ' J^EGET^BLE AND FRUIT PRODUCTS. 91 1 by boiling albumins with copper salts, due to the fcrmation of albuminate, or in the case of peas, leguminate of copper. Harrington * states that it is possible to color eggs an intense green by boiling with copper sulphate. Examination of a large number of brands of canned vegetables greened by copper, as bought in Massachusetts, showed that the amount used varied from a trace to 2.75 grams per can, calculated as copper sulphate. In justice to the consumer, who may be cautious about taking into his system copper salts, as well as to those who are indifferent to their use, it is no more than fair that all cans should have a label, plainly stating the quantity present. In the Massachusetts market, labels like the fol- lowing are not uncommon: "This package of French Vegetables con- tains an equivalent of Metallic Copper not exceeding three-quarters of a grain." Copper as a coloring matter has been most commonly found in peas, beans, and Brussels sprouts. Copper salts in minute quantity have been found in Massachusetts in canned tomatoes, clams, and squash, as well as in pickles. Salts of Nickel. — Sulphate of nickel has been employed instead of sulphate of copper for greening vegetables. According to Harrington f 0.25 gram of nickelous sulphate per kilogram of peas is used. The peas or other vegetables are boiled in a solution of the salt, made slightly alka- line with ammonia. Toxic Effects of Metallic Salts. — Divergence of opinion is so great as to the toxic eft'ects of salts of the heavy metals on the human system, when present in the small amounts commonly found in food products, that it is extremely difficult to maintain a complaint in court based entirely on the harmful effects of these salts. Since the question is one for the toxicologist or physiological chemist rather than the analyst to settle, it will not be discussed here at length ; suffice it to say that experi- ments made by the Referee Board indicate that while as much as 150 mg. of copper may be contained in the coppered beans or peas eaten in a day as little as 10 mg. under certain conditions may have a deleterious action and must be considered injurious to health. Accordingly foods greened with copper are considered adulterated by the federal authorities. J * Practical Hygiene, p. 203. t Ihid., p. 205. X Food Inspection Decision 148. j 912 FOOD INSPECTION AND ANALYSIS. PRESERVATIVES. No class of food products stands so little in need of these added sub- stances to arrest fermentation as canned foods, if properly prepared and, as a matter of fact, the use of antiseptics has been almost entirely discontinued. The Bleaching of Corn by artificial means before canning is usually accomplished by boiling the corn with sulphite of soda, thus giving to the product an unnaturally white color. The practice seems to have been more in vogue some years ago than at present, the popular taste now appar- ently preferring the natural rich yellow of fresh corn. Saccharin is claimed to possess antiseptic powers and is used in canned goods, but its primary purpose is as a sweetener. Salicylic acid, sodium benzoate, and beta-naphthol, although formerly used, are now seldom found in canned goods. "soaked goods." It has become quite common, especially in the case of peas, beans, and corn, to utilize for canning purposes those that have grown old and. dried, after soaking them for a long time. The presence of soaked peas in the market is generally more common in years when there is a scarcity in the pea crop. By the process of soaking, dried and matured field conx may be softened to such an extent as to be substituted for green or sweet corn in the canned product. These goods, frequently sold at a very low price, under some such tempting name as "Choice Early June Peas," are entirely devoid of that succulent property so highly prized in the fresh, goods, and are altogether so inferior in quality that their sale may justly be considered as fraudulent, unless their character is specified. In some- states the law provides that such a product, to be legally sold, shall have plainly marked on the label of the can the words "Soaked Goods" in letters of prescribed size. Detection. — Methods of detecting soaked goods are distinctly physi- cal rather than chemical. The appearance and taste of the goods furnish in most cases an unmistakable clue to their nature. Soaked goods are entirely lacking in juiciness, and in the flavors so characteristic of the various vegetables, when gathered and canned before becoming dry. The process of soaking is also said to develop the growth of the rudi- mentary stem of the embryo in the dried pea and bean. Peas and beans of the soaked variety are almost entirely lacking in the green color of VEGETABLE AND FRUIT PRODUCTS. 913 the fresh vegetables, unless the color has been artificially supplied. The liquid is commonly milky. In all cases it will be found that the solid grains or kernels of the peas, beans, and corn that have once been dried, though softened by the process of soaking, have much less water than the grains of the cor- responding vegetables that were gathered while still soft and succulent. METHODS OF ANALYSIS. Methods of Proximate Analysis. — As a rule, the contents of canned goods are intended to be entirely edible throughout, and contain little or no refuse or portions to be rejected. An exception to this is the occa- sional canning of certain fruits with stones or pits, which are, of course, to be removed. The can or package is first weighed before opening, and later the cleaned receptacle is weighed after its contents have been removed. The weight of the contents is thus ascertained by difference. For the analytical determinations, the contents of the can or bottle are intimately mixed to form a homogeneous pulp, so that parts taken for analysis are fairly representative of the whole. If considerable liquid is present, with some solid masses held in suspension therein, the liquid is best drained off, and the solid portions pulped separately in any con- venient manner, as by the use of a mortar, or by means of a household food-chopper. The whole is then thoroughly ntingled together. If desired, the weight of the liquid and solid portions may be separately ascertained before mixing. The analyst should use judgment and discrimination as to how various portions of the mass are to be best measured out for the deter- minations. Much depends on the consistency of the pulpy mass. It is often convenient to make a 20% solution or mixture of the material with water, using say 50 grams of the pulped sample in 250 cc. of water, such of the sample as is insoluble being disintegrated by shaking. Methods for determining water, ether extract, crude fiber, protein, and ash do not differ materially from those employed in the case of cor- responding fresh fruits and vegetables. These determinations, in the case of canned products, while useful in showing their food value, give little information as to their adulteration by the substitution of foreign vegetable or fruit pulp. Determination of Lead in Tin Alloy. — Method of Paris Municipal Laboratory.^ — The material, if soft, is hammered into a thin plate, and *Analyse des Matieres Alimentaires et Recherche de leurs Falsifications, 1894, p. 695. 914 FOOD INSPECTION ^ND ANALYSIS. 2\ grams are weighed out, transferred to a 250-cc. flask, and dissolved in 7 to 8 cc. of concentrated nitric acid. Evaporate to dryness on the sand-bath, add 10 drops of nitric acid and 50 cc. of boiling water, cool, and make up to 250 cc. with water. Let the residue settle and pour off through a filter 100 cc. of the clear, supernatant liquid, corresponding to I gram of the material. This contains the lead, while the tin is left behind in the residue, together with antimony if present. Add ID cc. of a standard solution of potassium bichromate (7.13 grams to the liter) and shake. Each cubic centimeter of this standard solution is sufficient to precipitate o.oi gram of lead. Allow the lead chromate formed to settle, and, if the solution is colorless, add 10 cc. more of the bichromate, or sufficient to be present in excess, as indicated by the yellow color. Filter, wash, and titrate the excess of bichromate with a standard iron solution, containing 57 grams of the double sulphate of iron and ammonia and 125 grams of sulphuric acid per liter. This iron solution should be kept under a layer of petroleum, and standardized against the potassium bichromate before use. Add, drop by drop, the iron solution to that containing the excess of bichromate. The color of the latter passes from pale green to bright green, when the chromate is completely reduced. Determine the end- point with a freshly prepared dilute solution of potassium ferricyanide, a drop of which is placed on a porcelain plate or tile in contact with a little of the solution titrated. A blue color is produced when the iron is present in excess. If the standard iron and bichromate solutions exactly correspond, i cc. of the iron solution is equivalent to 1% of lead, but the latter solution is usually a little weak. If w = number of cubic centimeters of iron solution necessary to reduce 10 cc. of the standard bichromate, I cc. of the iron solution = — . n If, now, r = number of cubic centimeters of iron solution necessary to reduce the excess of bichromate in the determination, and 5 = number of cubic centimeters of bichromate used, s r = per cent of lead in the alloy. Separation and Determination of Tin, Copper, Lead, and Zinc in Canned Goods. — Munson's Method* — The contents of the can are * U. S. Dept. of Agric, Bur. of Chem., Bui. 107 rev., p. 62. VEGET/IBLR AhID FRUIT PRODUCTS. 9 IS first evaporated to dryness, and from lo to 15 cc. of concentrated sul- phuric acid or enough to carbonize are added to the dry residue contained in a porcelain evaporating-dish, which is very gently heated over the flame till foaming ceases. Then ignite to an ash in a muffle, or carefully over the free flame, using a little nitric acid, if necessary, for oxidation of the organic matter. Add 20 cc. of dilute hydrochloric acid, and evaporate over the water-bath to dryness. Wash the residue into a beaker, slightly acidify with hydrochloric acid, and saturate with hydrogen sulphide without previous filtration. Heat the beaker on the water-bath, and pass the contents through a filter. Wash the precipitate, which contains sulphides of tin, lead, and copper, if these metals are present, while if there is zinc, it is contained in the filtrate. The precipitate is fused with sodium hydroxide in a silver crucible for half an hour, to increase the solubility of the tin, which would otherwise be dissolved with difficulty. The fusion is boiled up with hot water, acidulated with hydrochloric acid, and transferred without filtering to a beaker, in which hydrogen sulphide is added to saturation. This precipitates the sulphides of tin, lead, and copper (if these metals are present). The sulphide precipitate is collected on a filter, and thoroughly washed with hot water, the washings being rejected. Pass through the filter several portions of boiling ammonium sulphide, using about 50 cc. in all, or till all the tin is dissolved. Precipi- tate the tin from the combined filtrate with hydrochloric acid, filter, wash, ignite, and weigh as stannic oxide. The residue left on the filter, after dissolving out the tin sulphide, is then dissolved by treatment with nitric acid, which is filtered, and to the filtrate and washings ammonia is added nearly to the point of neutral- ization. Then add ammonium acetate. Filter off any precipitate of iron that may be formed. The filtrate is divided into two portions for determination of copper and lead. If lead is absent, determine the copper by titration with potassium cyanide* or electrolytically (p. 608). Copper is rarely present in sufficient amount to be determined, unless used for greening the vegetables. If notable quantities of lead are present, the solution is made acid with acetic, and the lead precipitated therefrom with potassium chromate, collected on a tared filter, washed with water acidified with acetic acid, dried at 100° C, and weighed as lead chromate. Or determine the lead by color-tests, as on page 918, For the determination of zinc, the filtrate from the first hydrogen- sulphide residue is evaporated to a volume of about 60 cc, and treated * Sutton, Volumetric Analysis, 8th ed., p. 204. gi6 FOOD INSPECTION AND ANALYSIS. with bromine water to oxidize the iron, as well as any excess of hydrogen sulphide remaining, the excess of bromine is then boiled off, and a few drops of concentrated ferric chloride added, to make the solution distinctly yellow, if not already so. Nearly neutralize with ammonia, and precipi- tate the iron with ammonium acetate. Filter, wash, acidify the filtrate with acetic acid, and precipitate the zinc with hydrogen sulphide. Filter, wash, ignite, and weigh as zinc oxide. The metals may be determined separately, as follows: Determination of Tin.* — Evaporate the contents of the can to dry- ness, and ignite in porcelain. Fuse the ash with sodium hydroxide in a silver crucible, boil the fusion with several portions of water acidulated with hydrochloric acid, filter, and precipitate the tin from the acid solu- tion with hydrogen sulphide. Dissolve the washed precipitate in ammo- nium sulphide, filter, and deposit the tin directly from this solution by electrolysis in the platinum dish which contains it, using a current of 0.5 ampere and the electrolytic apparatus described on page 608. Smith and Bartlett f employ the following method of solution : Weigh 50 grams of fish or 100 grams of vegetables in a porcelain dish and dry over night. Heat from 75 to 100 cc. of concentrated sulphuric acid in a Kjeldahl flask until acid fumes are visible, then add gradually small por- tions of the food product, heating the acid between additions until frothing ceases. Allow to cool, then add gradually to the charred mixture 25 cc. of concentrated nitric acid, which causes the evolution of red fumes and the generation of heat. Cool, add 25 cc. of nitric acid and heat gently until all nitric fumes are expelled and the charred material is dissolved to a homogeneous solution. Boil this solution about 45 minutes, then add from 10 to 15 grams of potassium sulphate and continue boiling from three to five hours until decolorized. Wash the digest into an 800 cc. beaker, dilute to about 600 cc. and bring to a boil. Almost all of the tin separates as stannic oxide, partially hydrated, some of which adheres to the sides of the flask, and cannot be removed by washing. Filter the contents of the beaker, thus separating the hydrated stannous oxide from all other com- pounds. Place the filter in the flask, to which 20 cc. of saturated sodium hydroxide and an equal volume of water have been added, boil for several minutes, then wash the sodium stannate into a beaker. Acidify with * Hilger u. Laband, Zeits. Unters. Nahr. Genussm., 2, 1899, p. 795; An. Rep. Mass. State Board of Health, 1899, p. 625. t A.O.A.C. Proc. 1910, U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 134- yEGETABl.E /tND FRUIT PRODUCTS. 917 hydrochloric acid, precipitate with hydrogen sulphide and proceed as above described. Hansen and Johnson * heat a quantity of the material, containing about 25 grams of solids, with a mixture of 200 cc. of water, 100 cc. of concentrated nitric acid and 50 cc. of concentrated sulphuric acid, adding additional nitric acid from time to time and finally 25 grams of potassium sulphate. Baker Method.-f — Treat 100 grams of the material with nitric and sulphuric acid as described in the preceding sections. Dilute the sulphuric acid residue, neutrahze with ammonia, add hydrochloric acid until the solution contains about 2%, and thoroughly saturate with hydrogen sulphide gas Filter the impure lead sulphide on a Gooch crucible with a false bottom, wash three or four times with water, then transfer precipitate and asbestos to a 300-cc. Erlenmeyer flask, washing with a little water, and boil with strong hydrochloric acid, adding potassium chlorate from time to time to insure complete solution of the tin sulphide as well as the elimination of the sulphur. Add a few strips of pure aluminum foil, free from tin, until all the chlorine is eliminated, then dilute to from 30 to 40% acid strength and attach to a carbon dioxide generator provided with a scrubber and charged with pure marble and hydrochloric acid. A bulb tube passing through one opening of a double-bore stopper serves to deliver the gas near the surface of the liquid and another bulb tube provides an exit, the latter being connected with a glass tube immersed in water to the depth of 20 cm., forming a water seal. Wlien the flask is first attached to the carbon dioxide apparatus, lift the exit tube out of the water so as to reduce the pressure and thus force a large amount of gas through the system, expelling all air. Then raise the stopper of the flask and introduce about i gram of aluminum foil, which quickly reduces the tin to the metallic form with evolution of hydrogen. Heat to boiling on a hot plate and boil for a few minutes, which causes the aluminum to disappear and changes the tin into stannous chloride, then cool in ice-water, still passing carbon dioxide through the system. Remove the stopper together with the tubes, washing the same and the sides of the flask with air-free water, prepared by boiling distilled water, adding a small amount of sodium bicarbonate and then a slight excess of hydrochloric acid. * A.O.A.C. Proc. 1911, U. S. Dept. of Agric, Bur. of Chem., Bui. 152, p. 117. t 8th Intern. Cong. Appl. Chem., 18, p. 35. 91 8 1^00 D INSPECTION AND ANALYSIS. Add starch paste and titrate directly and quickly with hundredth- normal iodine solution until a faint blue color is obtained. The iodine solution is standardized against pure tin solution or a food mixture, such as apple butter, containing an added amount of tin salt. An alternate procedure is to add an excess of iodine solution to the flask after lifting the stopper, but while the carbon dioxide is still issuing from the neck, and titrate the excess with standard sodium thiosulphate solution. By means of a Y tube the current from one generator may be divided for two flasks so that duplicates may be conducted at the same time. Determination of Lead, especially applicable if lead is present in small amounts only. Boil the sulphated ash of the contents of the can (obtained as on page 915) with a solution of ammonium acetate, having an excess of ammonia. The tin, zinc, and iron remain insoluble, while the copper and lead are dissolved. Filter, wash, and add a few drops of potassium cyanide to the filtrate, to prevent precipitation of copper when hydrogen sulphide is subsequently added. If the solution exceeds 40 cc, concen- trate to that amount by evaporation, and transfer to a 50-cc. Nessler tube. Add hydrogen sulphide water, and make up to the mark. Con- pare the brown color imparted by the lead sulphide, with the colors obtained by treating with hydrogen sulphide water in Nessler tubes various measured amounts of a standard solution of lead acetate, made alkaline with ammonia. Determination of Copper. — (i) Electrolytically . — Ash the contents of the can as on page 915. Wet the ash with concentrated nitric acid, add water, and boil. Then make strongly alkaline with ammonia and filter. Unless the filtrate is colored blue, copper is absent. Transfer the filtrate to a bright tared platinum dish of loo-cc. capacity, neutralize with concentrated nitric acid, and add about 2 cc. in excess. Nearly fill the dish with water, and electrolyze with the apparatus described on page 608, using a current of about 0.3 of an ampere. (2) Colorimetrically. — This method is especially applicable for —"all amounts of copper. The blue-colored ammoniacal solution of the ash, filtered as in (i), is transferred to a Nessler tube, and its color matched against the colors of a series of measured amounts of an ammoniacal standard solution of copper sulphate. Determination of Nickel. — Boil the ash with water slightly acidified with hydrochloric acid, and without filtering, saturate with hydrogen yEGETABLE AND FRUIT PRODUCTS. 919 sulphide, thus precipitating out any copper, tin, or lead. Filter and wash. Zinc and nickel, if present, are in the filtrate. Boil the filtrate to expel the hydrogen sulphide, and add sodium carbonate till slightly alkaline. Add acetic acid without filtering till the precipitate produced by the alkalme carbonate is dissolved, and then add a considerable excess of acetic acid. The zinc is precipitated by passing hydrogen sulphide through the cold dilute solution, while the nickel is held in solution by the large excess of acetic acid. Filter, and wash with hydrogen sulphide water, to which a little ammonium acetate has been added. Make the filtrate alkaline with ammonia, precipitate the nickel with ammonium sulphide, filter, wash, ignite, and weigh as nickelous oxide. KETCHUP. Standards.— The following are the standards of the A.O.A.C. and the Assn. of State and Nat. Food and Dairy Depts. : Catchup (Ketchup, Catsup) is the clean, sound product made from the properly prepared pulp of clean, sound, fresh, ripe tomatoes, with spices and with or without sugar and vinegar; Mushroom Catchup, Walnut Catchup, etc., are catchups made as above described, and conform in name to the substances used in their preparation. No standard is given for Chili Sauce, a product made from tomatoes, .peppers, onions, vinegar, sugar, and spices differing from ketchup in that it is not strained. ---■' Process of Manufacture. — When made in the household ripe tomatoes^ with or without paring and coring, are cut in pieces and boiled down to a thick pulp, strained to remove seeds and other coarse tissues and finally heated for a time with vinegar, spices and sugar. The product is bottled while hot. Factory-made ketchup, of good quality, is prepared by practically the same process, using special apparatus for washing, pulping and con- centrating. In many factories considerable time elapses before the finish- ing processes are carried out, the pulp being stored in barrels or better in lacquered tin receptacles until needed. Manufacturers of ketchup often purchase the barrelled or canned pulp from canning factories, con- fining their attention to the final processes and bottling. In the so-called gravity process the pulped material is allowed to stand until fermentation sets in and the cellular matter rises to the surface. The clear liquid is then removed from below. In Italy it is a common /920 FOOD INSPECTION AND ANALYSS. CHEMICAL COMPOSITION OF KETCHUP, PICKLES, AND RELISHES * Number of Analyses Refuse. Water. Protein. Fat. Total Carbo- hydrates Ash. 82.8 1-5 .2 12.3 3-2 86.4 1.4 .2 IO-5 i-S 58.0 I.I 27.6 II. 6 1-7 42.3 .8 20.2 «-5 1.2 64.7 1-7 25-9 4-3 3-4 52-4 1.4 21.0 3-5 2-7 92.9 -5 -3 2-7 3-6 93-8 I.I -4 4.0 -7 77.1 -4 .1 20.7 1-7 Fuel Value per Pound. Tomato ketchup.. Horseradish Olives, green : Edible portion.. As purchased... 'Olives, ripe: Edible portion.. As purchased . . Cucumber pickles Mixed pickles. .. . Spiced pickles. . . . 27.0 19.0 265 230 1,400 1,025 1,205 975 70 no 395 * U. S. Dept. of Agric, Office of Exp. Sta., Bui. 28, p. 70. practice in the manufacture of tomato paste to allow the pulp to ferment for a time, after which the fermentation is checked by the addition of salt-t Decayed Material. — According to Bacon and Dunbar % fresh tomatoes contain on the average 6.5% total solids, of which 3.5% is invert sugar, 0.5% citric acid, 0.6% ash, 0.9% protein (NX6.25), 0.85% crude fiber and 0.05% fat. During spoilage the sugars rapidly disappear, forming alcohol, carbon dioxide, acetic and lactic acids, the amounts of each formed depending on the organisms present. Usually the citric acid is also decomposed. A good ketchup is accordingly characterized by a high citric acid content and little lactic acid, while one made from decomposed material will usually contain little or no citric acid, but a high per cent of lactic acid. Tomato Refuse. — The skins, cores and other refuse from tomato canneries are used for the preparation of pulp which in turn is made into ketchup. Even with the use of such materials, when properly prepared, and before advanced fermentation has set in, Avith clean methods of hand- ling, the product may not be unwholesome. It is, however, sometimes the practice to allow the refuse and skins to accumulate through a whole tomato-canning season, storing them all in large vats, and working them up, after they have become badly fermented, for " fresh tomato ketchup." t Daily Consular and Trade Reports, 14, 1911, p. 74. iu. S. Dept. of Agric, Bur. of Chem., Circ. 78. VEGETABLE AND FRUIT PRODUCTS. 921 It is largely for this reason that antiseptics and coloring matters are so commonly employed in ketchup.* Foreign Pulp. — Pumpkin pulp and apple sauce, the latter made often from unsound material or even pomace, have been extensively used in cheap ketchups. At the present time such compound sauces are usually labelled to show the constituents present. Preservatives.— Salicylic acid, formerly used in most commercial ketchups, more recently has given place to benzoate of soda. Bitting f has shown that by using sound tomatoes and exercising proper care in the process of manufacture, ketchup can be kept without a preservative. Manufacturers are themselves corroborating this, many of the standard ■brands being entirely free from any antiseptic material other than spices and vinegar. Artificial: Colors. — Of ninety-five samples of ketchup examined in 1901 in Connecticut all but fifteen contained coal-tar colors. J This practice, however, is now decreasing and is indeed quite unnecessary if fresh ripe tomatoes are used, dark-colored spices are avoided, and sugar is not added until the end of the process. METHODS OF ANALYSIS. Ash, Alkalinity of Ash, and Sodium Chloride are determined by the methods described for jams and jellies (p. 936). Total Acidity is calculated as citric acid from the number of cc. of N/io alkali used in titration (i cc. = 0.0064 gram citric acid), Volatile Acids, as acetic, follow- ing the method for vinegar (p. 766). Tests for Preservatives and Colors are carried out as described in Chapters XVII and XVIII. Determination of Solids. — Weigh 10 grams of the sample into a flat- bottomed metal dish 6 cm. in diameter, add water to distribute the mate- * The writer has in his possession a circular from an Indiana commission merchant, ad- vertising for sale tomato pulp of some twelve different grades for ketchup. Among them are listed the following: "100 bbls. of old goods, made partly from whole stock and partly waste, boiled down nearly to ketchup thickness; has preservaline in it; fine goods, but some of it is fermented; packed in good oak whiskey and wine barrels. Price $2.00 per bbl." "225 bbls. new goods, made from waste; has benzoate of soda in it, packed in uncharred whiskey and wine barrels at $3.00 per bbl. net cash." "300 bbls. old goods, partly whole stock, partly waste, has salkylic acid in it; nice goods, etc. Price $2.00 per bbl." "400 bbls. new goods, Jersey style; solid and good red color, fine quality. Price $3.00 per bbl." t U. S. Dept. of Agric, Bur. of Chem., Bui. 119. t Ann. Rep. Conn. Exp. Sta., 1901. 922 FOOD INSPECTION AND ANALYSIS. rial, evaporate to dryness, dry 4 hours at the temperature of boiling water, and weigh. Determination of Insoluble Solids.* — Shake 20 grams of the material with hot water in a narrow cylinder, centrifuge and decant the clear liquid on a tared filter-paper and filter with the aid of suction. Repeat the operation several times, finally transferring the material to the paper. Finish the washing on the paper and dry at 100° C. to constant weight. The filtering may be carried on to advantage on a Buchner funnel, using two or more tared filters, asjhe suction is liable to break a single layer. Determination of Sand.* — Weigh 100 grams of the well-mixed sample into a 2- or 3-liter beaker, nearly fill the beaker with water, and mix the contents thoroughly. Allow to stand 5 minutes and decant the super- natant liquid into a second beaker. Refill the first with water and again mix the contents. After 5 minutes more decant the second beaker into a third, the first into the second, refill and again mix the first. Continue this operation, decanting from the third beaker into the sink until the lighter material is washed out from the ketchup. Then collect the sand from the three beakers into a tared Gooch crucible, dry, ignite, and weigh. The method for the determination of ash insoluble in hydrochloric acid is not applicable to the determination of sand in tomato products, because the percentage present is so small and the sand is so unevenly distributed that reliable results can only be obtained by taking a larger sample than is possible in the determination of ash. Determination of Soluble Solids.— Subtract the percentage of insoluble solids from the percentage of total solids. Determination of Reducing Sugars.— D»rc/.— Place 10 grams of the ketchup in a loo-cc. flask, add an excess of normal lead acetate, make up to the mark and filter. To the filtrate add powdered sodium sulphate or carbonate sufficient to precipitate the excess of lead and again filter. Determine the reducing power of the filtrate by the Munson and Walker method (p. 598) and calculate as invert sugar. After Inversion. — Mix 50 cc. of the solution, after clarifying and removal of the lead, as described in last paragraph, with 5 cc. of concentrated hydro- chloric acid, invert in the usual manner (p. 588), nearly neutrahze with sodium hydroxide and determine the reducing power as before inversion. * A.O.A.C. Proc. 1911, U. S. Dept. of Agric, Bur. of Chem., Bui. 152, p. iiS. VEGETABLE AND FRUIT PRODUCTS. 923 Determination of Citric XciA.^Bacon and Dunbar Method."^— Weigh 25 grams into a 250 cc. beaker, make up to approximately 200 cc. with 95 per cent alcohol, allow to stand with frequent stirring for tour hours, filter through a folded filter and wash with 50 cc. of 80 per cent alcohol. To the filtrate add sufficient water to dilute the alcohol to 50 or 60 per cent and then add 10 cc. of 20 per cent barium acetate solution, stir well with a glass rod, and allow to stand over night. In the morning filter on a Gooch crucible, washing with 50 per cent alcohol, dry for from 3 to 4 hours in an oven at 100° C. and weigh. Weight of pre- cipitate times 0.51 equals anhydrous citric acid. This method is not applicable in the presence of malic acid, hence if apple pulp is a constituent of the ketchup, the Pratt method (p. 951), should be employed. Determination of Lactic Acid. — Bacon and Dunbar Method.^ — To 100 grams of ketchup add 10 cc. of 20 per cent normal lead acetate solution, make up to 500 cc, shake well and centrifuge. To 400 cc. of the clear portion add a moderate excess of sulphuric acid, filter, wash the precipitate with a small amount of water, and evaporate the filtrate on the steam bath to about 100 cc. Extract for from 18 to 20 hours in a liquid extractor (Fig. 120) with washed ether. In case the quantity of lactic acid present is greater than 0.5 gram it is usually ne- cessary to extract for a longer period. In any case it is well to re-extract for from 8 to 10 hours to make sure that the extraction is complete. (Ether suf- ficiently pure for this purpose may be prepared by shaking out ordinary ether once with a sodium hydrate solution and then ten times with small quantities of water.) Evaporate on the steam bath F^<^- 120. — Bacon and until the ether is no longer evident, and take up t- -j ^^^^f>^ o , ^ Liquids. A, jacket- the residue at once in water and filter, thus remov- flash; B, extract-tube; ing a small amount of coloring matter and sub- C, funnel-tube, D, stances other than lactic acid, which may be condenser. ® E^i? w * U. S. Dept. of Agric, Bur, of Chem., Circ. 78, 191 1. 924 FOOD INSPECTION AND ANALYSIS. extracted from ketchup by ether, but which are insoluble in water. Heat the filtrate on the steam bath for some time to remove all traces of ether or alcohol. Add approximately 3 grams of sodium hydroxide and 50 cc. of a 1.5% solution of potassium permanganate from a pipette. Heat on a water-bath at 100° C. for one-half hour. At the end of that time, or before, if the color is not a decided blue-black or purple, but is green or colorless above the layer of brown precipitate, add more standard permanganate until, after heating one-half hour on a boiling water-bath, the color is a blue-black or purple. The oxidation is then complete. Make the hot solution strongly acid with 10 per cent sulphuric acid (about 50 cc.) and run in 5 per cent standard oxalic acid from a burette until the solution is decolorized. Titrate back any slight excess of oxalic acid with the standard permanganate solution. (Any standard permanganate and oxalic acid solution may be used within reasonable limits of strength.) In alkaline solution the permanganate oxidizes the lactic acid quan- titatively to oxalic acid according to the equation: 2C3H6O3 + ioKMn04 = 2 (COOH)2+ 4H2O -f 2CO2 + 5Mn02+ 5K2Mn04. Then in acid solution, the oxalic acid is further oxidized by the per- manganate to carbon dioxide and water according to the equation: 5(COOH)2 + 2KMn04 + 3H2S04=ioC02 + 8H20 + K2S04 + 2MnS04. To determine the total weight of permanganate used in the oxidation of the lactic acid subtract the permanganate equivalent of the oxalic acid used from the total amount used. The weight of permanganate times 0.237 equals the weight of lactic acid. Microscopic Examination for Spoilage. — Howard Method*.— The apparatus consists of a compound microscope with two objectives (f in. and ^ in.) and two compensating oculars (X6 and X18), a Thoma-Zeiss blood-counting cell, slides and cover glasses. 1. Estimation of Molds.— M.o\ini a drop of the material on a slide and press down the cover glass until the film is about o.i mm. thick. Examine, with a magnification of 90, approximately 50 fields and calculate the percentage of fields showing presence of mold filaments. This percentage for home-made ketchups is practically zero, and for factory-made ketchups should be kept below 25. 2. Estimation of Yeasts and Spores. — These are counted together because of the difficulty in differentiation without making cultures, which is impossible with a sterilized product. Thoroughly shake 10 cc. of * U. S. Dept. of Agric, Bur of Chem., Circ. 68, 1911. VEGETABLE AND FRUIT PRODUCTS. 925 the material with 20 cc. of water, and after standing one minute for the coarsest particles to settle, mount a drop in the Thoma-Zeiss cell. The material should not overrun the moat and Newton's rings must appear from the perfect contact of the glass surfaces to insure correct depth of liquid. With a magnification of 180, count the number of yeasts and spores in one-half of the ruled squares, which gives the number present in 1/60 of a cubic millimeter of the original material. The number in home-made and best factory-made ketchups, is practically none; the allowed limit is 25= 3. Estimation of Bacteria. — Only rod-shaped forms are considered, as micrococci are easily confused with particles of clay, etc. Employ- ing the mount used for yeasts and spores, and a magnification of 500, count the rod-shaped organisms in several areas of five small squares each and multiply the average by 2,400,000 which gives the number per cc. The limit for bacteria is 25,000,000 per cc. Microscopic Examination for Foreign Pulp. — Apple is identified by the window-like cells of the skin, the pitted vessels of the bundles, quite unlike the vessels of the tomato, and the tissues of the core. Pumpkin may be detected by the yellow skin of the fruit with colorless stomata, somewhat obscure latex tubes and the peculiar cactus-like parenchyma of the seeds. Although only the fruit pulp is used, fragments of the skin and seeds of sufficient size to be of diagnostic importance often find their way into the product. PICKLES. A large variety of vegetables and fruits are preserved in the form of pickles in vinegar, either with or without spices, and kept in wooden pails, stoneware pots, kegs, or sealed wide-mouthed bottles. The con- tainers are not of necessity air-tight. The commoner vegetables are usually pickled without cooking, while fruits such as peaches, pears, gooseberries, etc., are usually cooked, or at least heated. Analyses of pickles and relishes appear in the table, page 920. Cucumber Pickles are the m^ost common, and are prepared by soaking the fresh cucumbers in strong salt brine. They are then dried on frames, and afterwards treated with boihng vinegar, to which spices may or may not be added. Other vegetables pickled in similar manner, either sepa- rately or in mixture with cucumbers or " gherkins " to form " mixed pickles," are cauliflower, bean pods, white cabbage, young walnuts, and onions. 926 FOOD INSPECTION AND ANALYSIS. Such soft vegetables as young podded beans and beets are not treated with brine, but, after soaking in water, are directly treated with vinegar. The vinegar used for the finest pickling is of the cider, wine, or malt variety. Cheaper varieties of pickles are put up in "white wine" or spirit vinegar. Mustard Pickles. — These differ from plain vinegar pickles in the character of the preserving medium, which in this case consists of a mix- ture of mustard and spices with the vinegar to form a thin paste. Piccalilli consists of a mixture in vinegar of various chopped vege- tables, such as cucumbers, cauliflower, green pickles, onions, green toma- toes, and various spices. Olives for pickling are picked before they have fully ripened, and the inherent bitter taste is removed by soaking in a solution of potash and lime. This is replaced by cold water, and finally the olives are trans- ferred to the medium in which they are bottled, which consists of salt brine, either with or without flavoring. The flavoring materials employed consist of such substances as fennel, coriander, laurel leaves, and occa- sionally vinegar. Ripe olives in brine are also highly esteemed. Capers. — These are the flower buds of the shrub Capparis spinosa, which are pickled in vinegar. Nasturtium seeds, when similarly pickled, possess a flavor much resembling capers, but their substitution for capers could readily be detected by their distinctive appearance, even if colored. Adulteration of Pickles.^Green pickles, such as cucumbers, are not uncommonly colored artificially by copper salts, either through the addition of copper sulphate, as in the greening of peas, or by the use of copper vessels. This artificial greening is to be looked for also in such products as capers and olives. For methods of detection and estimation of copper, see page 902. Pickles may be greened by boiling with much less harmful substances than copper salts, such, for example, as grape leaves, spinach, or parsley. Free Sulphuric Acid has been found in a number of cases in the vine- gar of pickles bought on the Massachusetts market. A pronounced test for chloride with nitrate of silver should not be attributed to free hydrochloric acid, since it may be and probably is due to the salt from the brine in which the pickles have been treated. Alum is sometimes added to the salt solution to produce hardness and crispness in pickles. A number of samples of cucumber pickles have been found by the author to contain alum. For its detection, fuse the ash of the pickles, if free from copper, in a platinum dish with sodium l^EGETABLE AND FRUIT PRODUCTS. 927 Larbonate, extract with boiling water, filter, and add ammonium chlo- jide. A flocculent precipitate shows alum. Sodium Benzoate and Saccharine are frequently used in sweet pickles. Horseradish. — This condiment is prepared by grating the root of the perennial herb Nasturtium annoricia, and preserving in vinegar. It is very pungent and aromatic when first prepared, but by exposure to light and air quickly loses strength. Turnip, an occasional adulterant of grated horseradish, is best detected by the microscope. PRESERVES. Under this head are included various fruit products prepared with sugar syrup and often also with spices and vinegar. Some of these prod- ucts differ little from canned fruits white others are really sweet pickles. Mince meat, although not strictly a fruit product, and fruits in cordials are classified for convenience as preserves. Jams are considered with jellies in the next section, as are also methods of analysis. Fruit Butter. — According to the U. S. Standard, '' fruit butter is the sound product made from fruit juice and clean, sound, properly matured and prepared fruit, evaporated to a semi-solid mass of homogeneous consistence, with or without the addition of sugar and spices or vinegar, and conforms in name to the fruit used in its preparation." Apple Butter is the best-known product of this class. Unfortunately it is sometimes made from decayed fruit or even from apple pomace. Glucose is frequently substituted wholly or in part for sugar, in which case its presence should be declared on the label. Mince Meat. — As prepared in the household, mince meat, the filling for mince pies, contains from 10 to 20% of lean meat and about twice as much apple. Other constituents appear in the following typical for- mula with statement of quantities in parts by weight: 2 parts each of meat, raisins, dried currants, and sugar, 4 parts of apples, i part each of suet and candied citron, 2 parts of sweet cider, wine or brandy, i to 2 parts of seasoning including salt, spices, and lemons or oranges. Standard Mince Meat of the A.O.A.C. and the Association of State and National Dairy and Food Departments, " *s a mixture of not less than 10% of cooked comminuted meat, with chopped suet, apple and other fruit, salt, and spices, and with sugar, syrup, or molasses, and with or without vinegar, fresh, concentrated, or fermented fruit juices, or spirituous liquors." Adulteration. — There has been some conflict between food officials and certain manufacturers as to the proportion of meat in commercial 928 FOOD INSPECTION AND ANALYSIS. mince meat, the manufacturers claiming that 10% is too much for the proper keeping of the product, the food officials, on the other hand, con- tending that the manufacturer has no right to lower the recognized standard of the housewife. As a matter of fact the greater part of the mince meat on the market contains considerably less than 10% of meat and much of it none what- ever. Glucose is a common substitute for part of the sugar, wormy or other inferior fruit is sometimes used, and benzoate of soda is added as a preservative. Condensed Mince Meat is made in a commercial way from dried apples and other desiccated materials and is sold in compressed cakes with instructions for preparing from the cakes moist pie filling. As in the case of wet mince meat, glucose, wormy fruit and benzoate of soda are frequent admixtures and true meat is often omitted entirely. Wheat or rye flour is a common adulterant. Examination of Mince Afm/.— Meat and cereal flour may be identified by microscopic examination. Care should be taken not to confuse apple starch, which is always present in the immature fruit, with cereal starches. Meat fibers are recognized by their yellow brown color, the delicate trans- verse striations and their occurrence in bundles. Determinations of nitrogen are of service in estimating the amount of meat present. Glucose and sugar are calculated from the polarization readings. Pie Filling. Bakers and hotel cooks are supplied by manufacturers with filling prepared ready for use in pies. This material is shipped in pails or tubs preserved with benzoate of soda, and may contain fruit of questionable quality as well as admixtures such as starch, glucose, and artificial colors. Maraschino Cherries, — This name has been applied indiscriminately to the vivid red preserved cherries used in cocktails, punches, ice cream and confectionery. Investigation by the Board of Food and Drug Inspection has led to the decision * that only marasca cherries, preserved in true maraschino cordial prepared by fermentation and distillation from marasca cherries, are entitled to the name maraschino cherries, although cherries of other types preserved in pure maraschino cordial may be labelled: "Cherries in Maraschino." Ordinary cherries preserved in syrup flavored with maraschino may be so labelled, but if the flavoring is oil of bitter almonds or benzaldehyde the product should be labelled as an imitation if the word maraschino is used. * Food Inspection, Decision 141. VEGETABLE AND FRUIT PRODUCTS. 929 Enormous quantities of white cherries of the Bigarreau or Royal Anne type, preserved in a mixture of sulphurous acid and brine, are brought into the United States from Europe and transformed into red " Maraschino cherries " or green " Creme de menthe cherries." After removal of the sulphurous acid and brine the cherries are put through a dye bath and then, being quite without taste, are flavored with oil of bitter almond or benzaldehyde, or else peppermint, and packed in syrup. Scarcely more than the cellular structure of the original cherry remains, the fruit juice with its sugars, acids, and true cherry flavor being replaced by the syrup with its sickening flavor and aroma. Even if flavored with true maraschino the metamorphoses through which the fruit passes leave it a sorry substitute for the natural cherry. Woodman and Davis * have shown that true maraschino contains very little, benzaldehyde and that cherries flavored with maraschino should not contain more than two or three times as many milligrams of benzaldehyde per 100 cc. as there are grams of alcohol in that volume, and those containing over 20 mg. of benzaldehyde but no alcohol are evidently entirely artificial. Artificial colors, sulphurous acid and other preservatives are detected by the methods given in the chapters on colors and perservatives, benzalde- hyde by the following method : Determination of Benzaldehyde in Maraschino Cherries. — Woodman and Davis Method.^ — Reagent. — Mix 3 cc. of glacial acetic acid with ■40 cc. of water, add 2 cc. of C.P. phenylhydrazine, as near colorless as possible, shake thoroughly, and filter the emulsion through several thick- nesses of filter-paper. The clear filtrate should be used immediately as a turbidity appears on standing longer than five minutes. Process. — Dilute 100 cc. of the liquor from maraschino cherries (or 50 cc. of maraschino liqueur) to 140 cc. and distill off 1 10 cc. Determine approximately the alcohol in the distillate by the pycnometer or immersion refractometer, then without delay transfer 100 cc. to a 300 cc. Erlenmeyer flask and add alcohol or water so that the solution shall contain approx- imately 10% of alcohol. Add 100 cc. of the reagent, stopper tightly with a rubber stopper, and shake vigorously for ten minutes. Collect the precipi- tate in a tared Gooch crucible, wash with cold water and finally with about 10 cc. of 10% alcohol. Dry in a vacuum desiccator for 20-24 hours at about 20 cm. pressure, or in a vacuum oven at 70-80° C. for 3 hours. Throughout the process avoid exposure of the precipitate to strong light. * Jour. Ind. Eng. Chem., 4, 1912, p. 588. 930 FOOD INSPECTION AND ANALYSIS. Run a blank determination at the same time and deduct the weight obtained from that found in the actual analysis. Multiply the corrected weight of the precipitate by 0.541 1, thus obtaining the weight of benzalde- hyde. JAMS AND JELLIES. Jams or marmalades are prepared from the pulp of fruits, and jellies from the fruit juices. Both jams and jellies, to be considered of the highest degree of purity, should contain nothing but the fruit pulp or juice named on the label, mixed with pure cane sugar, and, in the case of jams, the further addition of spices and flavoring materials is permissible. For the manufacture of jam, apples, quinces, and pears are peeled, freed from cores, and sliced; berries are simply stemmed; and stone fruits, such as peaches and apricots, are peeled, and freed from stones. The material, properly prepared, is cooked with as much water as is necessary for boiling, and with the addition of an amount of sugar varying with different manufacturers. Some prefer to use equal parts of sugar and fruit, others one part sugar to two parts fruit. In the case of jelly, the fruit is cooked in a small amount of water till soft, transferred to a bag or press, and the juice allowed to flow out spontaneously, or is squeezed out under pressure, according to the grade of jelly desired, the clearest and finest varieties being made from the juice that flows out naturally. This juice is then evaporated down with the addition of sugar to a density of from 30° to 32° Be., which is of the proper consistency to form a perfect jelly product after cooling, and, while still hot, is poured into the tumblers in which it is to be kept. Here, as in the case of jams, the amount of sugar varies, some using pound for pound, and others only half as much sugar as fruit. Some manufacturers clarify their jellies by mixing with the juice, while boiling, elutriated chalk, using a teaspoonful to each quart of juice. The impurities come to the surface with the chalk as a scum, and are skimmed off. This clarifying process is somewhat analogous to the defecation of sugar ju'ces with lime, and is commonly carried out with apple jelly. The "jellying" or gelatinizing of the final product is due to the presence in the fruit juice of pectin, or so-called vegetable jelly (C32H40O284H2O) ; see page 276. The high content of added sugar in jelly, once thought to be essential for keeping it, is now no longer considered necessary, and much less sugar VEGETABLE AND FRUIT PRODUCTS. 931 is at present added than formerly. The finest grade of apple jelly, for instance, is made without any added sugar whatever. In making the better grades of apple jelly, apple juice fresh from the press is run directly into the boiler or evaporator before any fermenta- tion has ensued, and gelatinized by concentration. If boiled cider is wanted instead of jelly, it is drawn off at an earlier stage than in the case of apple jelly. Composition of Known-purity Jellies and Jams. — In the tables on pp. 932 and 933, due to Tolman, Munson, and Bigelow,* are given results reached on the examination of the pure finished products, as well as on pure fruit juices and pulp used in their manufacture. Adulteration of Jams and Jellies. — As a matter of fact, a small percent- age of these products sold in the United States are honest prototypes of the home-made jams and jellies, which consist exclusively of the fruit specified on the label, in mixture with pure cane sugar. If we accept as a standard the product of the housewife, fully 90% of the commercial brands of these preparations would be found wanting. So great is the demand for cheap sweets of this variety, that the market is flooded with them at eight and ten cents per half-pound jar, when in reality abso- lutely pure goods cannot be produced at much less than twice that amount. The cheap substitutes are made up largely of apple juice and com- mercial glucose, sometimes containing no fruit whatever of the kind specified on the label. Sometimes an attempt is made to imitate the flavor by the addition of artificial fruit essences, but more often the same apple-glucose stock mixture of jelly, put out under a particular brand, serves to masquerade as damson, strawberry, raspberry, current, grape, etc., differing from each other only in color, but not as a rule in flavor. A variety of artificial colors are employed, mostly coal-tar dyes. To compensate for the lack of sweetness of the glucose, a minute quantity of one of the concentrated sweeteners, such as saccharin or dulcin, is some- times added. Besides artificial colors, antiseptic substances are occasion- ally used, especially sodium benzoate. All grades of apple stock are found in these preparations. A large source of supply is furnished by the parings and cores of canning estab- lishments, to say nothing of the refuse of these factories, such materials being boiled with water, and the extract, variously colored to imitate the different fruits, being evaporated with commercial glucose. * Jour. Am. Chem. Soc. (1901), pp. 349-351. 932 FOOD INSPECTION /1ND ANALYSIS. u !r c Sic <" u,5 o u o n! -io«MO I I I I I I I 1 I I + I I I I I I I I I I I I 1 + I I 0>oOoO^ Tf lo r^ lO ro O M 00 t^oo O >-i r^ O CO "00^ in^oroin iO(N O <~orO-*i-i w ddodoooo M t^ t^OO O LO O O OS r^vO On ^ w O O O 1-1 O O O in 00 •i-oo <5 M uo\0 f^ O n\ o so lO lO LTi r^ Tt- CO 'I- "* Tt r-so SO rO o o o O o o o o o o O o o ■d- fO flOO o lO t^ <^ M ^ ISO OS too O 00 2 ii X a> „ Cd rt r^ HUB 1 ^^ «^ r* S ^ f? =3 5 UOOWOdnP^PkfLiPL, S^ NOONTteisOoOO>OOOOM iHOOoddoi-idoood t~~so i-iP)ir:(l-iO'^"MfO IS c o S >^ii 42.66 — 2 where S' is the per cent of cane sugar originally used, and h is the invert reading at /° of the normal solution. If, after inversion, the correct reading at 20° is found to be 12 or more to the left of the zero, it can be safely inferred that no appreciable amount of commercial glucose is present, and ii; is unnecessary to make a third VEGETABLE AND FRUIT PRODUCTS. 939 leading at 87°, unless to confirm the fact. In such a case, with cane sugar alone present, the reading at 87° will not, of course, vary much from o. Invert Sugar.— In the absence of commercial glucose, the invert sugar is calculated as follows : (Sucrose— direct reading)io5.3 Invert sugar = , ... (3) 42.66 2 or it may be determined directly from the copper reducing power. Any decided reading above zero at 87° is due to the presence of com- mercial glucose, and when the latter is present, it is impossible to deter- mine the invert sugar from the copper reduction or by formula No. 3. The following formula is proposed for calculating approximately the invert sugar from the polarization, in the presence of commercial glucose. While theoretically correct, the method is subject to practical limitations, which admit of only roughly approximate results in such mixtures as jelly or jam. It is perfectly accurate only in mixtures of sucrose, glu- cose, and invert sugar. /Reading due to glucose and\ /Invert reading\ _ I inverted sucrose at ^ / \ at /° / Invert sugar = ^ -^ 105.3 (4) ±42.66 — These formulas, (3) and (4), serve at best to indicate the approximate amount of invert sugar present in the sample, resulting from the inver- sion of a portion of the original sucrose in the natural process of manu- facture of the jam or jelly, and not the total invert sugar resulting from the inversion by the analyst of all the sucrose. The factor 105.3 i^ used, since, in the natural process of inversion, 100 parts of sucrose become 105.3 parts of invert sugar. Example. — ^The invert sugar in the sample of apple jelly first on tiie list in the table on page 936 is calculated as follows: Invert reading at f^ (20°) = 28.0. Reading due to glucose at 2o° = .22iX 175 = 38.68. *' act inverted sucrose at 20° = . 268 X —34= —9.1 1. . , (38.68-9.11)- 28 Invert sugar = -^ ^^-^ 105.3 = 5-76%. ' 940 FOOD INSPECTION AND ANALYSIS Determination of Reducing Sugar. — Proceed as described on page 621. Commercial Glucose, — While it is impossible to determine the exact percentage of this substance in preserves and jellies, by reason of the varying composition of its component parts, it is quite feasible to approx- imate very closely to the amount present. Indeed, this approximate method of calculation, wherein glucose is treated as a chemical entity, has been found in practice to be much more close to the actual truth than results gained by methods wherein the copper reducing power enters as a factor, or methods for determining separately dextrin, maltose, and dextrose. Calculate the commercial glucose in jellies and jams exactly as in the case of honey, p. 641. Dextrin.* — If alcohol be added to a somewhat thick solution of the fruit product, a white turbidity is at once apparent, followed by the forma- tion of a thick gummy precipitate, if dextrin is present. In the absence of dextrin there is no turbidity, but a light flocculent precipitate. To determine the dextrin, dissolve f 10 grams of the sample in a ioo-cc> flask; add 20 mg. of potassium fluoride, and then about one-quarter of a cake of compressed yeast. Allow the fermentation to proceed below 25° C. for two or three hours to prevent excessive foaming, and then place in an incubator at a temperature of from 27° to 30° C. for five days. At the end of that time clarify with lead subacetate and alumina cream ;^, make up to 100 cc. and polarize in a 200-mm. tube. A pure fruit jelly will show a rotation of not more than a few tenths of a degree either to the right or to the left. If a Schmidt and Haensch polariscope be used, and a 10% solution be polarized in a 200-mm. tube, the number of degrees read on the sugar scale of the instrument, multiphed by 0.8755, will give the percentage of dextrin, or the following formula may be used: Percentage of dextrin = 198X^x1^' in which C = degrees of circular rotation, V = volume in cubic centimeters of solution polarized, L = length of tube in centimeters, IF = weight of sample in solution in grams. * Bur. of Chem., Bui. 65, p. 78; Bui. 107 rev., p. 80. t Bigelow and McElroy, Jour. Am. Chem. Soc. 1893, 15, 668. VEGETABLE AND FRUIT PRODUCTS. 941 Determination of Alcohol Precipitate.* — Evaporate 100 cc. of a 20% solution of jelly, or of the washings from the determination of insoluble solids of a jam, to 20 cc; add slowly and with constant stirring 200 cc of 95% alcohol and allow the mixture to stand over night. Filter and wash with 80% alcohol by volume. Wash this precipitate off the filter paper with hot water into a platinum dish; evaporate to dryness; dry at 100° C. for several hours and weigh; then bum off the organic matter and weigh the residue as ash. The loss in weight upon ignition is called alcohol precipitate. The ash should be largely lime and not more than 5% of the total weight of the alcohol precipitate. If it is larger than this some of the salts of the organic acids have been brought down. Titrate the water- soluble portion of this ash with tenth-normal acid, as any potassium bitartrate. precipitated by the alcohol can thus be estimated. The general appearance of the alcohol precipitate is one of the best indications as to the presence of glucose and dextrin. Upon the addition of alcohol to a pure fruit product a flocculent precipitate is formed with no turbidity while in the presence of glucose a white turbidity appears at once upon adding the alcohol, and a thick, gummy precipitate forms. Determination of Tartaric, Citric, and Malic Acids. — Modified Schmidt- ■ Hiepe Method."^ — Use the filtrate from the alcohol precipitate in this determination. After evaporating the alcohol and taking up the acids with water add lead subacetate until the solution is alkaline, then filter and wash the precipitate until only a shght amount of lead remains in the washings. Wash the precipitate off the filter-paper into a beaker with hot water, precipitate the lead by hydrogen sulphide, and filter off the lead sulphide while hot, washing with hot water. Evaporate the filtrate which contains the free organic acids to about 50 cc, neutralize with potassium hydroxide, add an excess of strong solution of neutral calcium acetate with constant stirring, and allow to stand from six to twelve hours- Throw the precipitate of calcium tartrate on a filter-paper and wash until filtrate and washings make exactly 100 cc; ignite the filter-paper and precipitate, and determine the lime by titration. A correction of 0.0286 gram of tartaric acid, which is held in solution in the 100 cc of washings as calcium tartrate, must be added. Evaporate the filtrate down to about 20 cc. and if a precipitate of calcium citrate is formed col- lect it on a filter while hot, wash with hot water, ignite, and titrate. From * A. O. A.[C. Method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107, rev., p. 80. 942 FOOD INSPECTION AND ANALYSIS. this result calculate the citric acid. Evaporate the filtrate and washings from the calcium citrate to about 20 cc. and add three volumes of 95% alcohol, which will throw down the calcium salt of tartaric acid held in solution, the remaining citrate, and the malate and succinate. Filter, ignite the precipitate, titrate, and calculate as mahc acid after subtracting the tartaric acid present. (The amount of citric and succinic acid present is very small.) Determination of Citric Acid.* — Fifty cubic centimeters of the fruit solution is evaporated on the water-bath to a syrupy condition. To the residue add, very slowly at first, stirring constantly, 95% alcohol until no further precipitate is formed; 70 to 80 cc. are generally enough. Filter, and wash the residue with 95% alcohol. Evaporate the filtrate to eliminate the alcohol, take up the residue with a little water, and transfer to a graduated cylinder, making up to 10 cc. To 5 cc. of this solution, add half a cubic centimeter of glacial acetic acid, and to this add, drop by drop, a saturated solution of lead acetate. The presence of citric acid is shown by the appearance of a precipitate, which possesses the property of disappearing on being heated, and reappearing on cooling. In order to separate the citric acid from other acids, heat to boiling, filter, and wash with boiling water; then allow to cool, and the precipitate of lead citrate will re-form. This lead precipitate may be filtered off, washed with weak alcohol, dried, weighed, and the citric acid calculated. It is necessary that there shall be no tartaric acid present. If the tartaric acid has been estimated, any error on this account may be avoided by adding enough decinormal potash to neutralize the tartaric acid before the alcohol is added. Detection of Coloring Matter. — Boil white woolen cloth or worsted in a solution of the jelly or jam, acidified with hydrochloric acid, or with acid sulphate of potassium, according to Arata's method and test for the color on the dyed fabric by methods given in detail in Chapter XVII. Detection of Preservatives and Concentrated Sweeteners. — Extract an acid aqueous solution of the fruit product with ether or chloroform in a separatory funnel, and test for benzoic and salicylic acids and for sac- charin in the ether extract. If dulcin is suspected, extract with acetic ether. * Moslinger, Zeits. Unter. Nahr. Genussm.j 2, 1899, p. 93; U. S. Dept. of Agric, Bun of Chem., BuL 65, p. 80, yEGETABLE AND FRUIT PRODUCTS. 943 Detection of Starch.* — Heat an aqueous solution of the preserve or jelly nearly to the boiling point, and decolorize by the addition of several cubic centimeters of dilute sulphuric acid and afterwards permanganate of potassium. This treatment does not affect the starch, which is tested for with iodine in the ordinary manner in the solution after cooling. In the clear filtrate from a boiled apple pulp solution, free from added starch, little or no darkening should occur on the addition of the iodine reagent. If, however, the reagent is added to the residue of the previously boiled pulp, the presence of starch inherent in the apple is usually recognized by the blue color produced thereon. The presence of any considerable added starch paste in a fruit prepa- ration is thus readily indicated by an intense blue color obtained by adding the iodine reagent to the filtrate (free from fruit pulp). Detection of Gelatin. — Robin's Method.^ — Add to a thick aqueous solution of the preserve or jelly sufficient strong alcohol to precipitate the gelatin. Decant the supernatant liquid after settling, set aside part of the precipitate, and dissolve the remainder in water. Divide the latter solution in two parts, to one of which add, drop by drop, a fresh solution of tannin, which precipitates gelatin if present. To the remainder add picric acid solution, which in presence of gelatin forms a yellow precip- itate. The portion of the yellow precipitate set aside is transferred to a test tube, and heated over the flame with a little quicklime. If gelatin is present, ammonia will be given off, apparent by the odor, and by fumes of ammonium chloride when a drop of hydrochloric acid on a glass rod is held at the mouth of the bottle. Leffmann and Beam's Method-X — Boil the sample with water, filter, and boil the filtrate with an excess of potassium bichromate. Cool, and add a few drops of sulphuric acid. A flocculent precipitate indicates gelatin. Detection of Agar Agar.§ — The jelly is heated with 5% sulphuric acid, a little potassium permanganate is added, and, after settling, the sediment is examined by the microscope for diatoms, which will be found in large numbers if agar agar has been used. Detection of Apple Pulp. — A distinct clue to the presence of apple pulp in fruit preparations is often furnished by the characteristic apple * U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 81. t Girard, Analyse des Matieres Alimentaires, p. 676. % Select Methods of Food Analysis, p. 324. § Marpmann, Zeit. f. angew. Mikrosk, 1896, p. 260; U. S. Dept. of Agric, Bur. of Chem., Bui. 6s, p. 81. 944 FOOD INSPECTION AND ANALYSIS. odor given off when a small amount of the sample is heated to boiling- with water in a test tube. Under such conditions, the apple odor is quite apparent, as distinguished from that of other fruits, especially if the apple is the chief fruit present, or predominates in the mixture. Apple pulp in fruit preserves, free from added starch, may usually be recognized by a microscopical examination, using iodine reagent. The cell contents of the pulp will show the characteristic blue color, undoubtedly due to portions of unconverted starch still remaining in them. Detection of Fruit Tissues under the Microscope. Certam of the common fruits are readily identified in jams by their microscopic char- acters. This is especially true of most of the small fruits, the skins, styles and seeds being more or less characteristic in structure. The apple differs from the quince and pear in that stone cells are lack- ing; the starch of the green fruit is noteworthy. Peaches, plums and apricots, while possessing skins and stone peculiar to each, when pared and freed from stones are much alike in structure. Pineapples have peculiar needle-shaped crystals. Figs are identified by the " seeds " and hairs. Citrus fruits are remarkable because of the oil cavities and spongy parenchyma. Fragments of elements of the skins and cores of fruits, although pared and cored before preparation, find their way into the finished products, furnishing evidence to the microscopist. The seeds of berries are highly characteristic. DRIED FRUITS. Desiccation is the oldest and in some respects the most satisfactory method of preserving fruits. It is an economical method, as the apparatus and the process are simple, especially if the sun's heat is utilized for the evaporation; furthermore, the cost of the containers is small and the compact form of the product reduces the cost for transportation and storage to the minimum. From the sanitary standpoint dried fruit has certain advantages, notably the freedom from metallic impurities from the con- tainers; on the other hand, great care is required to protect the mj'terial during drying and handling from surface contamination. Xanti currants as well as raisins are dried grapes of certain Euiopean varieties. These, together with figs and dates, although produced in California and the Southern States, are imported into the United States in enormous quantities from the regions adjoining the Mediterranean. Apples, prunes, apricots, peaches, and cherries, on the other hand, are yEGET^BLB AND FRUIT PRODUCTS. 94$ produced in the United States in quantities not only sufiEicient for domestic needs but also for export. California fruits, such as raisins, prunes, apricots, peaches, and pears are sun-dried, as are also raisins, ligs, dates and other fruits produced about the Mediterranean. Apples are commonly dried in the United States by artificial heat, although the old process of sun drying is still practiced on a small scale in certain regions. Treatment with Lye. — Preliminary to drying certain fruits, such as raisins and prunes, are often dipped in a hot but weak solution of potash, which removes the bloom and otherwise acts on the skin, thus facilitating drying. Oil is also used with the lye in preparing " oil-dipped " Smyrna raisins. These methods of treatment are quite distinct from the lye- peeling process employed in preparing peaches, apricots, and some other fruits fox canning. Sulphuring of Fruit. — The treatment of fruits with the fumes of burning sulphur is practiced not only to bleach and prevent discoloration, but also to ward off the attacks of insects, fungi, and bacteria. It is allowed with restrictions in most European countries and also, pending further inves- tigation, in the United States, provided the amount of sulphur dioxide remaining in the fruit does not exceed 350 mg. per kilo, of which not more than 70 mg. is free sulphurous acid.* There is reason to believe that the sulphur dioxide exists in dried fruits in combination largely, if not wholly, with sugar, although possibly to some extent, as in wines, with acetaldehyde, or even with protein and cellulose. Sulphuring when used for purposes of deception, as for example in rejuvenating old or damaged stock or when used in excessive amount, is obviously improper. Analyses by government chemists show that when no restrictions were placed on sulphuring as high as 3072 mg. per kilo were present in dried peaches, 2842 mg. in California apricots and 1738 mg. in evaporated apples. Moisture Content of Dried Fruits. — An excessive amount of moisture in dried fruit is not only a worthless make-weight, but also facilitates the growth of molds and bacteria, causing rapid deterioration. In 1904 a law was passed in New York State requiring that dried apples contain not above 27% of moisture, determined by drying 4 hours at the temperature of boiling water. Wormy and Decomposed Dried Fruits.— Figs, dates, and currants from Europe, also dried apples, cherries, and other fruits of domestic * U. S. Dept. of Agric, Oflf. of Sec, Food Inspection Decision 76. 946 FOOD INSPECTION AND /IN A LYSIS. production often are infected with worms or are in a moldy or fermented condition due to careless drying or packing. Under the federal law such "' filthy, decomposed or putrid " fruit is adulterated. Zinc in Evaporated Fruit. — Apples dried in contact with galvanized iron trays may contain a small amount of this metal combined as malate which usually amounts to only o.oi to 0.02%, but reaches in extreme cases, according to Loock, 0.09%. This contamination can be entirely avoided by greasing the galvanized iron trays or covering them with greased cloth or else by the use of wooden trays. METHODS OF ANALYSIS. Preparation of the Sample. — If stones are present, separate and weigh. Reduce the edible portion to a uniform mass by grinding in a food chopper and tliorough mixing. Determine Ash, Nitrogen, Sugars, and Acids as described under Jams and Jellies, pp. 937 to 942, and Zinc as described on p. 915. Determination of Moisture. — Dry 5 grams of the ground sample for 24 hours in a flat-bottomed dish at the temperature of boiling water, and weigh. The New York State law with reference to dried apples makes no provision for grinding the sample, but does specify that the drying must be for 4 hours. Naturally this method yields lower results than that given above. Sulphurous Acid. — Determine by the distillation method as described in Chapter XVIII. FRUIT JUICES. Sweet cider, orange juice, lime juice, grape juice, raspberry shrub, and the juices of various other fruits and berries, may be so prepared and sterilized as to keep without fermentation when bottled, and are so put up in considerable variety, either with or without the addition of sugar. Such preparations, if of the highest purity, should consist of the undiluted juices of these fruits, separated by pressure and carefully ster- ilized and bottled. They should contain no other fruit juice than that specified on their labels, and should be free from alcohol, added antisep- tics, or coloring matter, unless the label specifies the presence of the added foreign materials. The addition of pure cane sugar to such prepara- tions as grape juice is allowable if declared, as well as charging with carbon dioxide to form so-called carbonated drinks. The following analyses of pure fruit juices are taken from tables VEGETABLE .4ND FRUIT PRODUCTS. 94/) prepared by Win ton, Ogden, and Mitchell, showing results on samples purchased in the Connecticut market, as well as on some samples made in the laboratory.* Solids. Acids Other than COoas Citric. Cane Sugar. Invert Sugar. Polarization. Direct. After Inver- sion. Temper- ature C. Invert Reading at &b° C. COMMERCIAL FRUIT JUICES, Blackberry Cherry Black currant Red currant Grape Lime fruit Orange Pineapple Plum Quince Black raspberry Strawberry MADE IN LABORA- TORY. Peach Red raspberry Blackberry Huckleberry Pineapple 5-32 14-33 10.00 7.58 15-29 7-7S 12.72 8.07 10.81 10.41 8.47 5-69 12.70 9-41 8. 04 11.40 13.90 0.65 0.80 2.41 2.09 0.91 6.50 2.44 o.8r 1. 00 0.99 1.36 0.99 0.95 1. 19 0.68 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1-5 0.0 0.0 0.0 0.0 5-4 0.8 0.0 0.6 7-4 4-6 6-5 9-2 7.2 0.0 7-1 5-1 0-3 7-8 5-1 2. 1 8.6 9-1 ■1-3 -1-3 -1.9 —1.9 -2.7 —2.7 -2.1 —2.1 ■6-5 -6.5 0.0 -2.1 0.0 I —2.0 ■0.1 —0.1 •5.0 -5.0 •3 -2-3 1-5 -1-5 -1.6 -2.4 -4.0 4-7 •2.2 ■2.8 •2.4 -4.8 ■4.8 29.0 26.0 26.0 27.0 26.0 26.0 26.0 25.0 26.0 26.0 2S.0 26.0 30.0 30.0 28.0 — i.o -0.8 Preservatives. — Formerly salicylic and boric acids were frequent additions, now sulphurous acid and sodium benzoate are the common preservatives. Beta-naphthol, formaldehyde, formic acid and fluorides have also been used. Unfermented Grape Juice has the following average composition if Austria. Per Cent. California, Per Cent. Solid contents bv spindle (Balling) '. 21.62 None -78 .01 19.62 .61 •03 -37 .02 20.60 None -53 -03 19-15 -59 .07 .19 .04 Alcohol Total acid (as tartaric) Volatile acid Grape sugar Cream of tartar Free tartaric acid Ash Phosphoric acid An. Rep. Conn. Exp. Sta., 1899, p. 136. t California Exp. Sta., Bui. 130. 948 FOOD INSPECTION AND ANALYSIS. Grape juice is prepared by sterilizing at a temperature of 80° the juice expressed from the crushed grapes, filtering by means of a press or otherwise, and sealing in carefully sterilized bottles. After bottling, a final sterilization is conducted at a temperature 5° below the first. Bottled grape juices are rarely carbonated. Bottled Sweet Cider. — ^The composition of pure, freshly expressed apple juice is shown by the following table of analyses by Browne:* Left- Total Unde- handed Specific Invert Su- Total Sugar Free ter- Rotation Gravity. Solids. Sugar. crose. Sugar. after Inver- sion. Malic Acid. Ash. mined (Pectin, etc.;. Degrees Ventzke 400 mm. Tube. Red astrachan 1-0532 12.78 6.87 3-63 10.50 10.69 1. 14 0-37 0.77 23.72 Early harvest 1-0552 13.29 7-49 3-97 11.46 11.67 0.90 0.28 0.65 24.32 Yellow transparent. 1.0502 II. 71 8.03 2.10 10.14 10.24 0.86 0.27 0.44 Sweet bough Baldwin, green. ... I . 0498 11.87 7.61 6.96 3.08 1.63 10.69 8.59 10.85 8.68 0. 10 39-40 36.16 1.0488 11.36 1.24 0.31 1.22 ' ' ripe 1.0736 16.82 7-97 7-05 15.02 15-39 0.67 0.26 0.87 Ben Davis 1-0539 12.77 7. II 3-«5 10.96 II. 16 0.46 0.28 1.07 49.00 Bottled sweet cider, properly sterilized, should not differ materially from the fresh juice, and should contain no alcohol. Salicylic acid, sodium benzoate and sodium or calcium bisulphite have been extensively used as preservatives. Benzoate is still much used. Lime or Lemon Juice. — This, according to the U. S. Pharmacopoeia, should consist of the freshly expressed juice of the ripe fruit of Citrus limonum (Risso), natural order of Rutaceae. Our supply of both lemons and limes comes chiefly from the West Indies and the Mediterranean. Both varieties of the genus Citrus are used indiscriminately for furnish- ing commercial lime juice, though strictly speaking, only that of the lemon is recognized in the Pharmacopoeia. The juice is sharply acid, and is largely composed of citric acid (about 7%), gum, sugar (3 to 4 per cent), and inorganic salts from 2 to 2| per cent. It also usually contains a little lemon oil from the rind. According to the pharmacopoeia, lemon juice {Limonis succus) should conform to the following require- ments : "Specific gravity: not less than 1.030 at 15° C. "It has an acid reaction upon litmus paper, due to the presence of about 7% of citric acid. * Penn. Dept. Agric, Bui. 58, p. 29. VEGETABLE AND FRUIT PRODUCTS. 949 "On evaporating 100 grams of the juice to dryness, and igniting the Tesidue, not more than 0.5 gram of ash should remain," Of thirty samples of commercial lime juice examined in the Massa- chusetts State Board of Health laboratory, representing fifteen brands, all were deficient in citric acid, containing from 1.92 to 4.15 per cent, thus showing that these preparations are frequently watered. Fifteen were found to contain salicylic acid, seven had sulphurous acid, while two contained both these preservatives. Several were found colored with coal-tar dyes. One sample examined by the author, purporting to be a "pure West Indian Lime Juice, triple refined," proved to be a mixture of hydrochloric and salicylic acids, colored with a coal-tar dye, and contained no lime juice whatever. METHODS OF ANALYSIS. Total Solids, Total Nitrogen, Ash, and Sugars are determined by the methods employed for jams and jellies (pp. 936 to 940), Solubility and Alkalinity of the Ash and Phosphoric Acid as described in the chapter on vinegar (p. 764). Colors and Preservatives are detected and determined as described in Chapters XVII and XVIII. Total Acidity. — Titrate 10 grams of the juice, diluted to 250 cc. with freshly boiled water, with tenth-normal alkali. Use phenolphthalein as indicator if the color of the juice will permit, otherwise delicate litmus paper. Calculate either as sulphuric acid or as the organic acid known to predominate. One cc. of tenth-normal alkali is equivalent to 0.0075 gram tartaric acid, 0.0067 gram malic acid and 0.0064 gram citric acid. Determination of Tartaric Acid — Proceed as directed for total tartaric acid in wine, p. 701, except that 20 cc. instead of 15 cc. of alcohol are used for precipitation. Determination of Malic Acid. — Dunbar and Bacon Method."^ — Dilute a weighed or measured amount of the fruit juice, usually 10 grams, with quite a large volume of water, add phenolphthalein, and titrate with standard alkali to a decided pink color. Weigh or measure another portion of the liquid (75 grams or cc. is a convenient amount) into a 100- cc. graduated flask, and add enough standard alkali, calculated from the * U. S. Dept. of Agric, Bur. of Chem., Circ. 76. Jour. Ind. Eng. Chem., 3, 1911, p. 826. 950 FOOD INSPECTION y4ND ANALYSIS. above titration, to neutralize the acidity. A slight excess of alkali is not objectionable. If the solution is dark colored, add 5 or 10 cc. of alumina cream. Dilute to the mark, mix thoroughly, and filter if necessary through a folded filter. Treat about 25 cc. of the filtrate with enough powdered uranyl acetate so that a small amount remains undissolved after two hours, 2.5 grams usually being sufficient, except in the presence of large amounts of malic acid. In case all the uranium salt dissolves more should be added. Allow to stand for two hours, shaking frequently, filter through a folded filter until clear and polarize if possible in a 200 mm. tube or, if too dark, in a 100 or 50 mm. tube. Designate this solution and reading as A. Treat the remainder of the original filtrate with powdered normal lead acetate until the precipitation is just complete, avoiding a large excess and consequent solution of lead malate. Cool in an ice bath and filter through a folded filter until clear. Warm the filtrate to room temperature and add a small crystal of lead acetate. If no precipitate forms, remove the excess of lead with anhydrous sodium sulphate, filter until clear, and polarize. Designate this solution and its polarization reading as B. Solutions which are sufficiently clear and contain less than 10% of sugar may be polarized directly without treatment with lead acetate. If reading B is negative treat a portion of solution B with uranyl acetate in the manner already described and polarize. Designate this as C. If reading B is positive, reading C need not be made. Polarize all solutions at a uniform room temperature with white light, using the average of at least six readings and calculating to the basis of a 200 mm. tube. If reading C is numerically less than reading B, the latter should be discarded; otherwise use reading B in the subsequent calcula- tion. Multiply the algebraic difference between this reading and reading A by 0.036, the product being the percentage of malic acid (C4H6O5) in the solution as polarized. Pratt's Modification* — Place a weighed amount of juice, generally 100 grams, in a 500 cc. beaker and add, with vigorous stirring, two or three times its volume of 95% alcohol. The pectin bodies are precipitated and usually in such a form that after standing a few minutes they may be gathered into a coherent mass. Decant the liquid through a filter and wash the precipitate twice with 95% alcohol. Evaporate the filtrate in a cur- rent of air on the water-bath to about 75 cc. After cooling make up to 100 cc. in a measured flask, using 10 to 15 cc. of 95% alcohol and dis- * U. S. Dept. of Agric, Bur. of Chem., Circ. 87. yEGETABLE AND FRUIT PRODUCTS. 951 tilled water. The temperature when the volume is finally made up to che mark should be close to that at which the polariscope readings are to be taken. Treat this solution exactly as in the original method, except that no clarification is necessary. Determination of Citric Acid.— Pm//'5 Method.^— This method is applicable in the presence of malic and tartaric acids. 1. Apparatus.— This consists of a 500 cc. distilling flask provided with a small dropping funnel drawn down to a small opening and pro- truding one-half inch below the stopper. In the flask is placed a glass rod with a piece of small tubing one-half inch long, sealed on the lower end to insure steady ebulhtion. This small tube should be filled with air when the heating begins. A condenser preferably of the spiral type- is connected with the flask. 2. Deniges Reagent. — Add about 500CC. of water to 50 grams of mercuric oxide; then add 200 cc. of concentrated sulphuric acid with constant stirring, and heat the mixture, if necessary, on a steam bath until the solution is complete. After cooling make up to a liter and filter. 3. Determination. — Weigh 50 grams of the fruit juice into a beaker and add no cc. of 95^,^ alcohol to throw out the pectin bodies. After standing fifteen minutes filter and wash with 95^7c; alcohol. Dilute the filtrate with water to approximately 50% alcohol content and add enough 20% barium acetate solution to precipitate the citric acid. Stir, let stand until the barium citrate partially settles, and filter. Wash twice with ^0% alcohol to remove the greater part of the sugar present. Remove all alcohol from the precipitate and filter either by drying in the beaker used for precipitation or else by washing with ether before removing from the funnel. Add 50 cc. of water and 3 to 5 cc. of sirupy phosphoric acid to the beaker containing the filter-paper and precipitate and warm, thus dissolving the barium citrate completely. Filter into a 100 cc. measuring: flask and wash up to the mark. Measure an ahquot containing from 0.05- to 0.15 gram of citric acid, into the distilling flask, add 5 to 10 cc. of sirupy phosphoric acid and 400 cc. of hot water. Connect with the condenser, heat and when briskly boiling, add potassium permanganate solution (0.5 gram per liter), i to 2 drops per second, until a pink color persists throughout the solution. Distill off the acetone formed by the oxidation into a liter Erlenmeyer flask containing 30 to 40 cc. of Deniges reagent, continuing the distilla- tion until 50 to 100 cc. remain in the flask. Boil the distillate gently^ * U. S. Dept. of Agric, Bur. of Chem., Circ. 88. 952 FOOD INSPECTION AND ANALYSIS. under a reflux condenser for forty-five minutes after it turns milky. Filter hot through a Gooch crucible, wash the precipitate with water, alcohol, and finally with ether, and dry in a water-oven for half an hour. The weight of the precipitate multiplied by 0.22 gives the weight of citric acid. FRUIT SYRUPS. Two classes of these preparations are on the market, one for use in soda-fountains, and one for " family trade," intended as a basis for sweetened drinks to be diluted with water and sugar. Some are made exclusively from pure fruit pulp and sugar, sterilized by heating and put up in tightly sealed bottles, while others of the cheaper variety are more apt to be entirely artificial both in color and in flavor, deriving the latter principally from the wide variety of artificial fmit essences now available. Commercial glucose is a frequent ingredient. The same classes of coal- tar dyes and antispetics are found in these preparations as in the other fruit products. Citric or tartaric acid is frequently added to genuine fruit syrups to bring out the flavor and to imitation fruit syrups to better simulate the characters of the genuine product. For purposes of comparison with such fruit-pulp preparations as may come to the analyst for examination, he is referred to the analysis of fruits found on page 274. NON-ALCOHOLIC CARBONATED BEVERAGES. Soda Water. — Originally the beverage known as soda water was prepared by the action of an acid on sodium bicarbonate in solution and corresponded to what is now obtained by dissolving Seidlitz powders in water. Later it was found that water charged with carbon dioxide was not only more practicable commercially but also more acceptable to the palate and this product was substituted for true soda water without change of name. As dispensed by the pharmacist and confectioner in the United States, soda water consists of a syrup, variously flavored, mixed at the " fountain " with carbonated water. The syrup is first placed in the glass, then the carbonated water is drawn into it in a large stream and finally more added in a fine stream to mix and froth the liquid. Ice cream or liquid " cream " is used with certain flavors, eggs and milk in " egg chocolate," " egg shake " and other nutritious mixtures, a solution of calcium acid phosphate in " orange phosphate " and other phosphates — in fact there appears to be FECETABLE AND FRUIT PRODUCTS, 953 'no end to the preparations and combinations introduced by ingenious venders to quench the thirst, gratify the palate, and furnish nourishment in an easily digestible form. Carbonated Water, the basis of all effervescent drinks, is prepared by charging ordinary water with carbon dioxide in a steel drum, known as the fountain. Formerly the gas was generated on the premises by the action of mineral acid on marble, but now it is obtained in Hquid form in steel cylinders from mineral springs and the fermentation industries where it formerly went to waste. The process of carbonating consists In allowing the gas to discharge into the water, rocking the fountain continually to aid absorption. A gauge indicates the pressure in the fountain, which should be about 170 pounds per square inch for soda water and somewhat less for ginger ale and root beer. The steel drum or fountain proper is kept in the cellar or other convenient place and the carbonated water is piped to the so-called fountain where the drinks are served, or, in the case of bottled beverages, to the machine for filling the bottles. Needless to say both the water and the gas should be free from con- tamination, and the introduction of metallic salts from the lead pipes and other sources should be guarded against. Soda Water Syrups.^ — Sugar and flavors are added to carbonated beverages in the form of syrups. At the soda fountain these are drawn into the glass from small reservoirs or poured from bottles, while in the bottling works measured quantities both of syrup and carbonated water are introduced into each bottle by an automatic machine. Fruit Syrups are prepared either by the manufacturer of soda water supplies or else by the pharmacist or confectioner who serves the beverages. More . commonly the manufacturer supplies the fruit juice or fruit pulp in bottles or jars, spoilage being avoided either by sterilization or the use of sodium benzoate. The vender mixes the juice or pulp with sugar syrup as needed. Orange, lemon, and lime syrups are commonly made from the oils rather than from the fresh fruit, the necessary acidity being supplied by citric acid. This acid as well as tartaric acid is also used in strawberry, raspberry and other true fruit syrups to bring out the flavor. Imitation Fruit Syrups flavored with mixtures of ethers such as are described on pp. 895 to 897, are frequently substituted for genuine fruit syrups at soda fountains and quite universally in the preparation of cheap bottled soda water. Aside from the deception to the consumer these mix- tures are highly objectionable because of their nauseating and unwhole- some properties. 954 FOOD INSPECTION /IND ANALYSIS. Various Syrups not belonging under the head of fruit syrups are drawn from fountains and used in bottled beverages. Among these are vanilla, cofifee, chocolate (really cocoa), ginger, sarsaparilla, and mixtures sold under distinctive names. Bottled Carbonated Beverages. — To this class belong various non- alcoholic beverages known as " soda " " soft-drinks " and " temperance drinks." Some of these are high-grade articles of national or even inter- national reputation, so prepared as to keep indefinitely, while others are cheap preparations of local manufacture sold for immediate consumption in pleasure resorts. Ginger Ale, by far the best-known bottled carbonated beverage, is made from ginger (or ginger extract) with the addition of lemon juice (or lemon oil and citric acid) and carbonated water. Capsicum extract, known in solid form as capsicin, is frequently substituted in part for the ginger because of its greater pungency. Root Beer was formerly brewed from a sweetened infusion of various roots and herbs, the gas being formed by a true fermentation process. A similar beverage is now made in the household, using so-called " root- beer extract," but the commercial product is commonly charged, like soda water, with carbon dioxide gas. Birch Beer, formerly made by fermentation, is now merely soda water flavored with oil of birch or synthetic methyl salicylate. Sarsaparilla, so called, is flavored with a mixture of oil of birch, natural or synthetic, and oil of sassafras. The dark color is due to caramel or other artificial colors. Lemon Soda and Orange Soda are flavored respectively with terpene- less lemon and orange extract, the acidity being contributed by citric acid. Orangeade belongs in the same class. So-called blood-orange soda is probably never made from blood oranges, the color being artificial. Vanilla Soda is more correctly vanillin soda or vanillin and.coumarin soda. The term cream soda applied to this colorless beverage is equally misleading. Strawherrv Soda, Raspberry Soda and other bottled beverages purport- ing to be made from fruits are commonly imitations flavored with ethers and colored with coal-tar dyes. So-called Cherry Soda is flavored with an extract of cherry bark or benzaldahyde. Sweeteners in Beverages. — Sugar is the only proper sweetener for syrups or bottled beverages- Glucose because of its lower sweetening power is unsuited for the purpose, while saccharin and other chemical sweeteners are objectionable both because of their lack of nutritive prop- yEGETABLE AND FRUIT PRODUCTS. 955 erties and their possible injury to health. The use of saccharin, which has hitherto been extensive, is now prohibited in beverages entering into interstate commerce. Acids in Beverages. — Citric and tartaric acids are used not only in imitation but also in true fruit syrups to bring out the flavor. Lemon juice serves the same purpose, but is more expensive and does not keep so well. Calcium acid phosphate is a characteristic constituent of orange and other fruit phosphates. Preservatives. — ^Sodium benzoate is the common preservative of bev- erages, although its use is by no means universal. Formerly salicylic, boric and sulphurous acids and even fluorides were employed. Artificial Colors. — Cochineal, cudbear, caramel and the seven colors allowed by U. S. decisions are most commonly met with. The use of fuchsin, acid fuchsin, rhodamine, tartrazine and other coal-tar colors has been largely discontinued. Foam Producers. — Froth on soda water is cheaper to produce than the same bulk of liquid, furthermore it is sanctioned by custom. Soap-hark, the bark of Quillaja Saponaria, a common foam producer, contains two saponins, sapotoxin and quillaiac acid, both of which are poisonous. In addition these principles combine with the cholesterin of the blood and if in excess dissolve the corpuscles. Commercial saponin, prepared from Saponaria officinalis, and consist- ing largely of sapotoxin, is also extensively used. Foam producers are also used in malt liquors. Glycerrhizin, the characteristic principle of licorice, also serves as a foam producer. Habit-forming Drugs in Beverages. — Caffein, extract of cola leaves, and cocaine are ingredients of certain proprietary syrups and beverages, contributing their well-known stimulating properties. The use of caffein is defended on the ground that it is the active principle of tea and coffee. Opponents of this drug have pointed out that tea and coffee are recognized as improper articles of diet for children and invalids, furthermore, the presence of other consituents tends to prevent the excessive use of these beverages. Again the presence of caffein in carbonated beverages is not usually known to the consumer, and he forms the habit without proper warning. It would be difificult to find an argument in favor of the use of a drug so potent as cocaine or products containing cocaine. 956 FOOD INSPECTION /1ND ANALYSIS. METHODS OF ANALYSIS. Transfer the sample to a flask and shake at intervals for an hour or two, at room temperature, thus removing most of the carbon dioxide. Use the liquid thus obtained for the several determinations, measuring out the portions, if desired, and calculating the weight from the specific gravity. Total Solids, Ash, Acidity, Sugars, and Organic Acids are determined as directed for jams and jellies (pp. 936 to 942J using 25 grams of the liquid except for the polarizations, which may be made on normal quantities. Vanillin, Coumarin, Citral, and Methyl Salicylate are detected and determined by the methods described under the head of Flavoring Extracts, with such modifications as are necessitated by the absence of alcohol on the one hand and the greater dilution on the other. Methods for the detection of Ginger and Capsicum are given on page 894. K* Detection of Colors, Preservatives, and Sweeteners. — See Chapters XVII, XVIII and XIX. Determination of Phosphoric Acid. — This determination is made in so-called " orange phosphate," " raspberry phosphate " and other beverages containing calcium acid phosphate. Treat 25 grams of the liquid according to the method described on p. 346, except that the entire residue, after ignition with magnesium nitrate, is used for the determination, without aliquoting. Determination of Alcohol. — Follow the method prescribed for wines (p. 658). The amount of volatile oil present is seldom sufficient to appre- ciably affect the result. Detection of Saponin. — Of the various color tests that have been proposed none has been found absolutely characteristic, especially if glycerrhizin is present, although the reactions with sulphuric acid and Frohde reagent are of considerable value. The haemolysis test is believed to be reliable even in the presence of glycerrhizin. Whichever test is applied the saponin should be separated from interfering substances as follows : I. Extraction of Saponin hy the Riihle-Brummer Method.* — In the .case of soda water and other products containing organic or mineral acids (other than carbonic), to 100 cc. of the liquid add an excess of pre- cipitated magnesium carbonate and filter. If dextrin is present, as in the case of malt liquors, evaporate 100 cc. of the liquid to 20 cc, pre- * Zeits. Unters. Nahr. Genussm., 5, 1902, p. 1197; 16, 1908, p. 165; 23, 1912, p. 566. rnCETylBLE /IND FRUIT PRODUCTS. gST cipitate with 150 cc. of 95% alcohol, let stand 30 minutes then heat to boiling, filter, dilute the filtrate with water and dealcoholize, finally making up the solution to 100 cc. To 100 cc. of the neutral, dextrin-free solution in a separatory funnel, add 20 grams of ammonium sulphate, 9 cc. of phenol and shake thoroughly. Draw off the watery layer and shake the phenol solution with a mixture of 50 cc. of water, 100 cc. of ether, and (if necessary to avoid an emulsion) 4 cc. of alcohol. Allow to stand until the liquids separate, which usually requires 12 to 24 hours. Draw off the aqueous solution and evaporate nearly to dryness, finishing the drying either at 100 ° C. or in a desiccator, the latter being preferable if the residue is to be purified by treatment with acetone, which is usually desirable. Employ this extract, consisting of saponin and impurities, in the following tests: II. Tests for Saponin. — i. Sulphuric Acid Test. — Rub up a portion of the extract with a few drops of sulphuric acid. Saponin is indicated by the appearance in a few minutes of a reddish color changing in half an hour to red-violet and finally to gray. 2. Frohde Test. — Treat another portion in like manner with a few drops of a mixture of 100 cc. of concentrated sulphuric acid and i gram of ammonium molybdate. In the presence of saponin the drops in 15 minutes become violet, changing later to green and finally to gray. 3. Foam Test. — Shake another portion of the extract with water and note its foam-producing properties. In the presence of glycerrhizin none of the last three tests is reliable. 4. Haemolysis Test. — This process is recommended by Rusconi,* Sormali,! and Rhiile.J The following details are given by Rhlile and are based on the method as described by Gadamer : § {a) Reagents. — (i) Physiological Salt Solution.— Dissolve 8 grams of sodium chloride in water and make up to one liter, (2) One per cent Defibrinated Blood.— Shake vigorously fresh ox blood in a sterilized, salt-mouth, 500-cc. bottle with 20 glass beads 5-7 mm. in diameter. Separate from the clot of fibrin and store in a sterilized container in a refrigerator. Properly cared for it should keep for several- days. Dilute with 100 volumes of physiological salt solution for use. (3) One per cent Blood Corpuscles. — Centrifuge 100 cc. of the 1% * Bol. Soc. Med. -Chi. Pavia, 1910. t Zeits. Unters. Nahr. Genussm. 23, 191 2, p. 562. t Ibid. p. 566. V § Lehrbuch der chemischen Toxicologic. Gottingen, 1909, p. 443. 958 FOOD INSPECTION /IN D^ ANALYSIS. defibrinated blood in physiological salt solution, pour off the clear solu- tion containing the cholesterol and make up again to loo cc. with the salt solution. This preparation is more sensitive than solution (2). (b) Process. — Dissolve about o.i gram of the extract in 25 cc, of physiological salt solution, filter, and shake i, 2, and 3 cc. of this solution in small test-tubes with i cc. portions of 1% defribinated blood. If saponin is present the liquid becomes clear in from a minute to an hour or two, depending on the amount of saponin in the beverage and the num- ber of cc. of the solution used. As a confirmatory test dissolve i mg. of cholesterol in a small amount of ether, shake with 10 cc. of the solution of the extract in salt solution, heat at 36° C, for a few hours to remove ether, avoiding concentration, and treat portions of this solution with 1% defibrinated blood as above described. Cholesterol destroys the haemolytic action of the saponin, hence the liquids should not become clear in these tests. In order to exert this influence cholesterol should be present to the extent of i part to 5 parts of saponin. If only a small amount of saponin is present the haemolytic action can best be noted under a microscope magnifying to 300 diameters. Mount a drop of the solution of the extract in salt solution and place a drop of either solution (2) or (3) in contact with it. The saponin causes the corpuscles in contact with it to swell, then become strongly refractive, and finally dissolve. Determination of Ca&em.—F idler Method.'^ — Weigh 50 grams or measure an equivalent volume into a small beaker, add 5 cc. of concentrated ammonium hydroxide, allow to digest over night; then add 2 cc. more of ammonium hydroxide, heat for two hours, transfer to a large separatory funnel, dilute with 3 volumes of acid, add 5 cc. of ammonium hydroxide and shake out with four successive portions of chloroform, each of 50 cc. In case any dyestuff is removed by the chloroform, shake out with a satu- rated solution of sodium bisulphite, which will remove some of the color. Distil off the bulk of the chloroform and evaporate the remainder in a porcelain dish. Dissolve the residue in 25 cc. of 2% sulphuric acid, shake out with five portions of 15 cc. each of chloroform, filter the combined chloroform solutions into a flask, distil off the bulk of the chloroform and evaporate in a tared dish; dry at 100 ° C. and weigh. If the caffein is not pure, dissolve in 15 cc. of 10% hydrochloric acid, add an excess of a solution of 10 grams of iodine and 20 grams of potas- * A. O.A.C. Proc. 1910, U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 191- VEGET/IBLE AND FRUIT PRODUCTS. 959 rsium iodide in 100 cc. of water, allow to stand over night, filter, and wash twice with 10 cc. of the iodine solution. Transfer filter and precipitate to the original precipitation flask, add sufficient sulphurous acid to dissolve the precipitate, heating gently, filter into a separatory funnel, wash three times with water, and add ammonium hydroxide in excess, shake out four times with 15 cc. portions of chloroform, and filter the chloroform extracts into a flask, using a 7 cm. filter and keeping the funnel covered with a watch glass. Wash the filter with 5 portions of 5 cc. of chloroform. If the chloroform extract is colored, concentrate, add a small amount of animal charcoal, rotate several times and filter. Distil off part of the solvent and evaporate the remainder in a tared dish, dry at 100° C, and weigh. Detection and Determination of Cocaine. — Fuller Method. "^ — To 200 cc. of the sample in a large separatory funnel, add concentrated am- monium hydroxide to alkahne reaction, and shake out with three portions of 50 cc. each of Prolius mixture (4 parts ether, i part chloroform, i part alcohol), collecting the solvent in another separatory funnel. If desired the aqueous solution may be reserv^ed for the detection of salicylic and benzoic acids and saccharine. Filter the combined ProHus extracts into an evaporating dish, and evaporate on a steam bath, removing the dish as the last traces of solvent disappear. Dissolve the residue in normal sulphuric acid, transfer to a separatory funnel and shake out four times with 15 cc. portions of chloroform; wash the combined chloroform solu- tions once with water, reject the chloroform, and add the water extract to the original acid solution. Add 10 cc. of petroleum ether boiling at 40° to 50° C, and shake; draw off the acid layer, rejecting the petroleum ether, add concentrated ammonium hydroxide in excess and shake out three times with 15 cc. portions of petroleum ether, collecting the ethereal solu- tions in another separatory funnel. To the latter add 10 cc. of water and shake thoroughly ; reject the water extract and filter the petroleum ether into a beaker, washing twice with 10 cc. portions of the solvent. Evaporate over a steam bath, using a fan. By this method, if coca alkaloids are present, a nearly colorless residue will be obtained, which will finally crystallize on standing. Dissolve the residue in petroleum ether and divide into four portions, one of which may be small. Evaporate the solvent and to the small portion add a few drops of normal sulphuric acid, warm gently, filter into a test-tube, and add a drop of potassium mercuric iodide test solution (Meyer's reagent). A precipitate indicates an alkaloid but does not *A.O.A.C. Proc. 1910, U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 192. 960 FOOD INSPECTION AND ANALYSIS. identify it as cocaine; if no precipitate forms, cocaine is not present and further test is unnecessary. To another portion add a few drops of concentrated nitric acid, and evaporate on a steam bath until the acid is all driven off, then add a few- drops of half normal alcoholic potash and note the first odor that comes off, which, if cocaine is present, is that of ethyl benzoate. The residue of the third portion should be applied to the end of the tongue by rubbing with the finger. Cocaine will cause a numbness which is not apparent immediately, but develops gradually, and persists for a longer or shorter time according to the amount present. Remove a portion of the fourth residue to a microscopic slide, add a drop or two of gold chloride test solution, and stir vigorously, noting the character of the crystals under the microscope. All the above tests should be checked by controls on pure cocaine. If a quantitative determination of coca alkaloids is desired the residue after evaporating the petroleum ether should be weighed, then, as a check on the gravimetric determination, warmed in 50 cc. of fiftieth-normal sulphuric acid until dissolved, cooled, and titrated with fiftieth -normal potassium or sodium hydroxide, using cochineal as indicator. The fac- tor for cocaine is 0.006018. Determination of Caffein and Detection of Cocaine and Glycerine. — Fuller if e//wG?.*-^ Weigh 50 grams of the sample into an evaporating dish, add 5 cc. of concentrated ammonium hydroxide, cover with a watch-glass and allow to stand 12 hours. Add 2 cc. more of ammonium hydroxide and evaporate on the steam bath. Warm the residue with 25 cc. of 95% alcohol, on the steam bath, cool, and pour off the alcohol into another evaporating dish, repeating the treatment four times. Evaporate the combined alcoholic extract, dissolve the residue in 25 cc. of 2% sulphuric acid, transfer to a separatory funnel and shake out 5 times with 15 cc. portions of chloroform. Reserve the acid liquid for subsequent tests for cocaine and glycerine. Distil off most of the chloroform, evaporate in a dish on a steam bath, dissolve the residue in 10% hydrochloric acid and transfer to a small flask. Add to the acid solution an excess of iodine solution (10 grams iodine and 20 grams potassium iodide in 100 cc. of water), rotate flask, .allow to settle over night, filter, and wash flask and precipitate twice with the iodine solution, then transfer filter and precipitate to the flask. Heat gently wuth sufficient sulphurous acid solution to dissolve the precipitate, A. O. A. C. Proc. 1910, U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p, 192. VEGETABLE AhID FRUIT PRODUCTS. 961 filter into a separatory funnel, cool, add excess of concentrated ammonium hydroxide, and shake out four times with 15 cc. portions of chloroform. Filter the chloroform extract into a flask, using a 7 cm. filter in a small funnel covered with a watch-glass, or filter through cotton plugged in the stem of the separatory funnel. Decolorize the chloroform, if neces- sary, with animal charcoal, distil off most of the chloroform, then evapo- rate in a tared dish over steam, dry at 100° C. and weigh. Add an excess of concentrated ammonium hydroxide to the solution from which the caffein was extracted, shake out three times with petroleum ether, boiling at 40° to 60° C, filter ether solution, divide into four parts, evaporate, and test for cocaine as described in the preceding method. Evaporate the aqueous solution from the cocaine extraction with milk of lime and proceed as in the determination of glycerine in wines (p. 703). . The glycerine thus obtained will be only an approximation to the true amount. REFERENCES ON VEGETABLE AND FRUIT PRODUCTS. Adams, M. A. Composition and Adulteration of Fruit Jams. Analyst, 9, 1884, p. 100. Angell, a. Microscopical Structure of Fruits, etc., to be met with in Jams and Preserves. Analyst, i, 1877, p. 73. Bacon, R. F., and Dunbar, P. B. Changes taking place during Spoilage of Toma- toes, with Methods for Detection of Spoilage. U. S. Dept. of Agric, Bur. of Chem., Circ. 78. Baier, E., u. Hasse, p. Ueber die Zusammensetzung von 1907-er Obst- und Beeren- frlichte. Zeits. unters. Nahr. Genuss., 15, 1908, p. 140. Behre, A., Grosse, F., u. Thimme, K. Beitriige zur Kenntnis der Fruchtsafte des Jahrganges 1907. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 131. Beythien, A. Ueber Fruchtsafte und Marmeladen. Zeits. Unters. Nahr. Genuss 6, 1903, p. 1095. Ueber die Verwendung der Schwefligen Saure als Konservierungsmittel, insbeson- dere den jetzigen Stand der Beurteilung geschwefehen Dorrobstes. Zeits Unters. Nahr. Genuss., 8, 1904, p. 36. Einige weitere Analysen von Fruchtsaften und Beerenfriichten. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 544. Beythien, A., u. Bohrisch, P. Ueber amerikanisches getrocknetes Obst. Zeits. Unters. Nahr. Genuss., 5, 1902, p. 401. Beitrage zur Untersuchung und Beurteilung des Citronensaftes. Zeits. Unters. Nahr. Genuss., 9, 1905. p. 449. Ueber geschwefeltes Dorrsobst. Zeits. Unters. Nahr. Genuss., 6, 1993, p. 355. 962 FOOD INSPECTION /tND ANALYSIS. Beythien, a., Borisch, P., u. Hempel, H. Ueber die Zusammensetzung der i905-er?Citronensafte. Zeits. Unters. Nahr. Genuss., 11, 1906, p. 651. Beythien, A., u. Simmich, P. Beitrage zur Untersuchung und Beurtheilung der Marmeladen. Zeits. Unters. Nahr. Genuss., 20, 1910, p. 241. BiGELOW, W. D., and Gore, H. C. Studies on Peaches. U. S. Dept. of Agric, Bur. of Chem., Bui. 97. Ripening of Oranges. Jour. Am. Chem. Soc, 29, 1907, p. 767. Study of Apple Marc. Jour. Am. Chem. Soc, 28, 1906, p. 200. BiGELOW, W. D., Gore, H. C, and Howard, B. J. Studies on Apples. U. S. Dept. of Agric, Bur. of Chem., Bui. 94. ■ Growth and Ripening of Persimmons. Jour. Am. Chem. Soc, 28, 1906, p. 688. BlOLETTi, F. T., and dal Piaz, A. M. Preservation of Unfermented Grape Must. Cal. Exp. Sta. Bui. 130. Bitting, A. W. .Experiments on the Spoilage of Tomato Ketchup. U. S. Dept. of Agric, Bur. of Chem., Bui. 119. BoDMER, R., and Moor, C. G. On Copper in Peas. Analyst, 22, 1897, p. 141. BosELEY, L. R. The Analysis of Marmalade. Analyst, 23, 1898, p. 123. Browne, C. A. A Chemical Study of the Apple and Its Products. Penn. Dept. of Agriculture, Bui. 58. Jour. Am. Chem. Soc, 23, 1901, p. 869. Buchanan, G. S., and Schryver, S. B. On the Presence of Tin in Certain Canned Foods. Local (British) Govt. Board, Rep. of Insp. of Foods, 7, 1908. Budden, E. R., and Hardy, H. Colorimetric Estimation of Lead, Copper, Tin, and Iron. Analyst, 19, 1894, 168. Buttenberg, p. Zur Kenntnis und Beurteilung des Himbeersaftes. Zeits. Unters. Nahr. Genuss., 9, 1905, p. 141. Buttenberg, Hempel, Thamm, Luhrig, Juckenack, Baier, et al. Fruchtsaft- statistik, 1906. Zeits. Unters. Nahr. Genuss., 12, 1906, p. 721. Chace, E. M., To man, L. M., and Munson, L. S. Chemical Composition of Some Tropical Fruits and their Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 87. Doremus, C. a. Collecting and Analyzing Gases in Canned Goods. Jour. Am. Chem. Soc, 19, 1897, p. 733. Dubois, W. L. Analyses of Canned Peas, Showing Composition of Different Grades. U. S. Dept. of Agric, Bur. of Chem., Circ. 54. Farnsteiner, K. Ueber organisch gebundene Schweflige Saure in Nahrungsmitteln. Zeits. Unters. Nahr. Genuss., 7, 1904, p. 449. Fischer, R., u. Alpers, K. Beitrage zur Kenntnis der 1907-er Fruchtsafte und Marmeladen. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 144. Formenti, C, u. Aristide, S. Zusammensetzung italienischer Tomatensafte. Zeits. Unters. Nahr. 3enuss., 12, 1906, p. 283. Gore, H. C. Studies on Apple Juice. Jour. Am. Chem. Soc, 29, 1907, p. 1112. Unfermented Apple Juice. U. S. Dept. of Agric, Bur. of Chem., Bui. 118. Halmi, J. Ueber ungarische Fruchtsafte, etc. Zeits. Unters, Nahr. Genuss., 15, 1908, PP- 153. 277- Hausner, a. The Manufacture of Preserved Foods and Sweetmeats. London, 1902. VEGET.4BLE AND FRUIT PRODUCTS 963 HiLGARD, E. W., and Colby, G. E. Investigations of Canned Products. Rep. CaL Exp. Sta. 1897-98, p. 159. HiLGAR, A., u. Laband, L. Ueber electrolytische Abscheidung von Kupfer Zink und Zinn aus Konserven. Zeits. Unters. Nahr. Genuss., 2, 1899, p. 795. HiLTNER, R. S. A Rapid Method for the Analysis of Tin and Terne Plate. Wes- tern Chem. and Met. 4, 1908, p. 262. HusMANN, G. C. Manufacture and Preservation of Unfermented Grape IMust. U. S. Dept. of Agric, Bur. of Plant Ind., Bui. 24. JucKENACK, A., u. Pasternack, R. Ueber die Zusammensetzung der Fruchtsafte und Fruchtsyrupe. Zeits Unters. Nahr. Genuss., 8, 1904, p. 548. Untersuchung und Beurtheilung von Fruchtsaften. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 10. JuCKENACK, A., u. Pr-ANSE, H. Untersuchung und Beurteilung der Marmeladen, Fruchtmuse, Gelees und ahnlicher Erzeugnisse der Obstverwertungs-Industrie. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 26. KiCKTON, A. Untersuchung getrockneter Aprikosen. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 675. Krzizan, R., u. Plahl, W. 1905-er Himbeersafte und-syrupe bohmischer Herkunft. Zeits! Unters. Nahr. Genuss., 11, 1906, p. 205. Ladd, E. F. Food Products and their Adulteration. (Canned Goods, Ketchups, Jellies, Jams and Extracts.) North Dak. Exp. Sta., Buls. 53 and 57. LUDWIG, W. Beitrag zur Untersuchung und Beurteilung von Marmeladen. Zeits, Unters. Nahr. Genuss., 13, 1907, p. 5. Beitrage zur Untersuchung und Beurteilung von Fruchtsaften. Zeits. Unters. Nahr. Genuss., 11, 1906, p. 212. Luhrig, H. Zur Kenntnis und Beurteilung des Himbeersaftes. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 657. Zur Kenntnis des Citronensaftes. Zeits. Unters. Nahr. Genuss., 11, 1906, p. 441. Luhrig, Beythien, Juckenack u. Baier. Fruchtsaftstatistik, 1905. Zeits. Unters Nahr. Genuss., 10, 1905, p. 713. Macfarlane, T. Unfermented Grape Juice. Can. Inl. Rev. Dept., Bui. 82. McElroy, K. p., and Bigelow^, W. D. Canned Vegetables. U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 8. McGiLL, A. Canned Meats. Can. Inl. Rev. Dept., Bui. 85. — — Canned Vegetables. Can. Inl. Rev. Dept., Bui. 87. Lime Juice and Catsup. Can. Inl. Rev. Dept., Bui. 83. MuNSON, L. S. Canned Vegetables. U. S. Dept. of Agric, Bur. of Chem., Bui. 50, p. 50. MuNSON, L. S., and Tolman, L. M. Fruits and Fruit Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 74. MuNSON, L. S., ToLMAN, L. M., and Hov^^ard, B. J. Fruits and Fruit Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 66. Norton, F. A. Discoloration of Fruits and Vegetables put up in Tin. Jour. Am. Chem. Soc, 28, 1906, p. 1503. The Ripening of Peaches. Jour. Am. Chem. Soc, 29, 1905, p. 915. Prescott, S. C, and Underwood, W. L. Micro-organisms and Sterilizing Processes in the Canning Industry. Tech. Quarterly, 10, 1897, p. 183; also 11, 1898, p. 6. 964 FOOD INSPECTION /IND ^N^ LYSIS V. Raumer. Untersuchung und Beurteilung eingekochter Beeren und Fruchtmar- meladen. Zeits. Unters. Nahr. Genuss., 6, 1903, p. 481. ROHRIG, A. Konzentrierte Fruchtsafte. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 148. ScHWARZ, F., u. Weber, O. Beitrag zur Fruchtsaftstatistik fUr das Jahr. 1907. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 147. Spaeth, E. Ueber Fruchtsafte (besonders Himbeersaft) und deren Untersuchung. Zeits. Unters. Nahr. Genuss., 2, 1899, p. 633; 4, 1901, pp. 97, 920. Ueber die Untersuchung und Beurteilung von Himbeersyrup. Zeits. Unters. Nahr. Genuss., 8, 1904, p. 538. Street, J. P. Canned Peas. Conn. Exp. Sta., Rep., 1910, p. 456. Ketchup. Ibid., p. 521. Stuber, W. Zusammensetzung der Tomate. Zeits. Unters. Nahr. Genuss,, 11, 1906, p. 578. Ueber Apfelsinensaft. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 273. ToLMAN, L. M. The Polarization of Fruits, Jellies, Jams and Monies. Jour. Am. Chem. Soc, 24, 1902, 515. ToLMAN, L. M., MuNSON, L. S., and Bigelow, W. D. The Composition of Jellies and Jams. Jour. Am. Chem. Soc, 23, 1901, d. 347. Traphagen, F. W., and Burke, E. Occurrence of Salicylic Acid in Fruits. Jour. Am. Chem. Soc, 25, 1903, p. 242. VON West, E. Beitrage zur Analyse des Johannisbeersaftes. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 595. Wilson, H. M. Adulteration of Tinned Peas by Copper. Pub. Health, April, 1892, p. 203. WiNDiscH, K. Ueber das natiirliche \'orkommen von Salicylsaure in Erdbeeren und Himbeeren. Zeits. Unters. Nahr. Genuss., 6, 1903, p. 447. WiNDiscH, K., u. Schmidt, P. Beitrage zur Kenntnis der Fruchtsafte. Zeits. Unters. Nahr. Genuss., 17, 1909, p. 584. WiNTON, A. L. Detection of Coal Tar Dyes in Fruit Products. Jour. Am. Chem. Soc, 22, 1900, p. 582. ■ Beitrage zur Anatomie des Beerenobstes. Zeits. Unters. Nahr. Genuss., 5, 1902, p. 785. Withers, W. A., and Primrose, H. W. Preservatives in Canned Foods in North Carolina. North Car. Exp. Sta., Bui. 165. APPENDIX. THE FOOD AND DRUGS ACT, JUNE 30, 1906, AS AMENDED AUGUST 23, 1912. AN ACT FOR PREVENTING THE MANUFACTURE, SALE, OR TRANSPORTATION OF ADULTERATED OR MISBRANDED OR POISONOUS OR DELETERIOUS FOODS, DRUGS, MEDICINES, AND LIQUORS, AND FOR REGULATING TRAFFIC THEREIN, AND FOR OTHER PURPOSES. Be it enacted by the Senate and House of Representatives of the United Stales of America in Congress assembled, That it shall be unlawful for any person to manufacture within any Territory or the District of Columbia any article of food or drug which is adulterated or misbranded, within the meaning of this Act; and any person who shall violate any of the provisions of this section shall be guilty of a misdemeanor, and for each offense shall, upon conviction thereof, be fined not to exceed five hundred dollars or shall be sentenced to one year's imprisonment, or both such fine and imprisonment, in the discretion of the court, and for each subsequent offense and conviction thereof shall be fined not less than one thousand dollars or sentenced to one year's imprisonment, or both such fine and imprison- ment, in the discretion of the Court. Sec. 2. That the introduction into any State or Territory or the District of Colum- bia from any other State or Territory or the District of Columbia, or from any foreign coun- try, or shipment to any foreign country of any article of food or drugs which is adulterated or misbranded, within the meaning of this Act, is hereby prohibited; and any person who shall ship or deliver for shipment from any State or Territory or the District of Columbia to any other State or Territory or the District of Columbia, or to a foreign country, or •who shall receive in any State or Territory or the District of Columbia from any other State or Territory or the District of Columbia, or foreign country, and having so received, shal' deliver, in original unbroken packages, for pay or otherwise, or offer to deliver to any other person, any such article so adulterated or misbranded within the meaning of this Act, or any person who shall sell or offer for sale in the District of Columbia or the Ter- ritories of the United States any such adulterated or misbranded foods or drugs, or export or offer to export the same to any foreign country, shall be guilty of a misdemeanor, and for such offense be fined not exceeding two hundred dollars for the first offense, and upon conviction for each subsequent offense not exceeding three hundred dollars or be imprisoned not exceeding one year, or both, in the discretion of the court: Provided, That no article shall be deemed misbranded or adulterated within the provisions of this Act when intended for export to any foreign country and prepared or packed according to the specifications or directions of the foreign purchaser when no substance is used in the preparation or pack- ing thereof in conflict with the laws of the foreign country to which said article is intended to be shipped; but if said article shall be in fact sold or offered for sale for domestic use or consumption, then this proviso shall not exempt said article from the operation of any of the other provisions of this Act. 96s 966 FOOD INSPECTION ^ND ANALYSIS. Sec. 3. That the Secretary of the Treasury, the Secretary of Agriculture, and the Secretary of Commerce and Labor shall make uniform rules and regulations for carrying out the provisions of this Act, including the collection and examination of specimens of foods and drugs manufactured or offered for sale in the District of Columbia, or in any Territory of the United States, or which shall be offered for sale in unbroken packages in any State other than that in which they shall have been respectively manufactured or pro- duced, or which shall be received from any foreign country, or intended for shipment to any foreign country, or which may be submitted for examination by the chief health, food, or drug officer of any State, Territory, or the District of Columbia, or at any domestic or foreign port through which such product is offered for interstate commerce, or for export or import between the United States and any foreign port or country. Sec. 4. That the examinations of specimens of foods and drugs shall be made in the Bureau of Chemistry of the Department of Agriculture, or under the direction and super- vision of such Bureau, for the purpose of determining from such examinations whether such articles are adulterated or misbranded within the meaning of this Act; and if it shall appear from any such examination that any of such specimens is adulterated or misbranded within the meaning of this Act, the Secretary of Agriculture shall cause notice thereof to be given to the party from whom such sample was obtained. Any party so notified shall be given an opportunity to be heard, under such rules and regulations as may be prescribed as aforesaid, and if it appears that any of the provisions of this Act have been violated by such party, then the Secretary of Agriculture shall at once certify the facts to the proper United States district attorney, with a copy of the results of the analysis or the examination of such article duly authenticated by the analyst or officer making such examination, under the oath of such officer. After judgment of the court, notice shall be given by publication in such manner as may be prescribed by the rules and regulations aforesaid. Sec. 5. That it shall be the duty of each district attorney to whom the Secretary of Agriculture shall report any violation of this Act, or to whom any health or food or drug officer or agent of any State, Territory, or the District of Columbia shall present satisfactory evidence of any such violation, to cause appropriate proceedings to be commenced and prosecuted in the proper courts of the United States, without delay, for the enforcement of the penalties as in such case herein provided. Sec. 6. That the term " drug," as used in this Act, shall include all medicines and preparations recognized in the United States Pharmacopoeia or National Formulary for internal or external use, and any substance or mixture of substances intended to be used for the cure, mitigation, or prevention of disease of either man or other animals. The term " food," as used herein, shall include all articles used for food, drink, confectionery, or condiment by man or other animals, whether simple, mixed, or compound. Sec. 7. That for the purposes of this Act an article shall be deemed to be adulterated: In case of drugs: First. If, when a drug is sold under or by a name recognized in the United States Phar- macopoeia or National Formulary, it differs from the standard of strength, quality, or purity, as determined by the test laid down in the United States Pharmacopoeia or National Formulary official at the time of investigation: Provided, That no drug defined in the United States Pharmacopoeia or National Formulary shall be deemed to be adulterated under this provision if the standard of strength, quality, or purity be plainly stated upon the bottle, box, or other container thereof although the standard may differ from that determined by the test laid down in the United States Pharmacopoeia or National Formulary. Second. If its strength or purity fall below the professed standard or quality under which it is sold. APPENDIX. 967 In the case of confectionery: If it contain terra alba, barytes, talc, chrome j^ellow, or other mineral substance or poisonous color or flavor, or other ingredient deleterious orjdetrimental to health, or any vinous, malt, or spirituous liquor or compound or narcotic drug. In the case of food : First. If any substance has been mixed and packed with it so as to reduce or lower or injuriously affect its quality or strength. Second. If any substance has been substituted wholly or in part for the article. Third. If any valuable constituent of the article has been wholly or in part abstracted. Fourth. If it be mixed, colored, powdered, coated, or stained in a manner whereby damage or inferiority is concealed. Fifth. If it contain any added posionous or other added deleterious ingredient which may render such article injurious to health: Provided, That when in the preparation of food products for shipment they are preserved by any external application applied in such manner that the preservative is necessarily removed mechanically, or by maceration in water, or otherwise, and directions for the removal of said preservative shall be printed on the cov- ering or the package, the provisions of this Act shall be construed as applying only when said products are.ready for consumption. Sixth. If it consists in whole or in part of a filthy, decomposed, or putrid animal or vegetable substance, or any portion of an animal unfit for food, whether manufactured or not, or if it is the product of a diseased animal, or one that has died otherwise than by slaughter. Sec. 8. That the term " misbranded," as used herein, shall apply to all drugs, or articles of food, or articles which enter into the composition of food, the package or label of which shall bear any statement, design, or device regarding such article, or the ingredients or substances contained therein which shall be false or misleading in any particular, and to any food or drug product which is falsely branded as to the State, Territory, or country in which it is manufactured or produced. That for the purposes of this Act an article shall also be deemed to be misbranded: In case of drugs: First. If it be an imitation of or offered for sale under the name of another article. Second. If the contents of the package as originally put up shall have been removed, in whole or in part, and other contents shall have been placed in such package, or if the package fail to bear a statement on the label of the quantity or proportion of any alcohol, morphine, opium, cocaine, heroin, alpha or beta eucaine, chloroform, cannabis indica, chloral hydrate, or acetanilide, or any derivative or preparation of any such substances contained therein. Third.* If its package or label shall bear or contain any statement, design, or device regarding the curative or theraupetic effect of such article or any of the ingredients or sub- stances contained therein, which is false and fraudulent. In the case of food: First. If it be an imitation of or offered for sale under the distinctive name of another article. Second. If it be labeled or branded so as to deceive or mislead the purchaser, or pur- port to be a foreign product when not so, or if the contents of the package as originally put up shall have been removed in whole or in part and other contents shall have been placed in such package, or if it fail to bear a statement on the label of the quantity or propor- tion of any morphine, opium, cocaine, heroin, alpha or beta eucaine, chloroform, cannabis * This paragraph constitutes the amendment. 968 FOOD INSPECTION AND ANALYSIS. indica, chloral hydrate, or acetanilide, or any derivative or preparation of any of such sub- stances contained therein. Third. If in package form, and the contents are stated in terms of weight or measure, they are not plainly and correctly stated on the outside of the package. Fourth. If the package containing it or its label shall bear any statement, design, or device regarding the ingredients or the substances contained therein, which statement, design, or device shall be false or misleading in any particular: Provided, That an article of food which does not contain any added poisonous or deleterious ingredients shall not be deemed to be adulterated or misbranded in the following cases: First. In the case of mixtures or compounds which may be now or from time to time hereafter known as articles of food, under their own distinctive names, and not an imitation of or offered for sale under the distinctive name of another article, if the name be accom- panied on the same label or brand with a statement of the place where said article has been manufactured or produced. Second. In the case of articles labeled, branded, or tagged so as to plainly indicate that they are compounds, imitations, or blends, and the word " compound," " imitation," or " blend," as the case may be, is plainly stated on the package in which it is offered for sale: Provided, That the term blend as used herein shall be construed to mean a mixture of Hke substances, not excluding harmless coloring or flavoring ingredients used for the pur- pose of coloring and flavoring only: And provided further. That nothing in this Act shall be construed as requiring or compelling proprietors or manufacturers of proprietary foods which contain no unwholesome added ingredient to disclose their trade formulas, except in so far as the provisions of this Act may require to secure freedom from adulteration or misbranding. Sec. 9. That no dealer shall be prosecuted under the provisions of this Act when he can establish a guaranty signed by the wholesaler, jobber, manufacturer, or other party residing in the United States, from whom he purchases such articles, . to the effect that the same is not adulterated or misbranded within the meaning of this Act, designating it. Said guaranty, to afford protection, shall contain the name and address of the party or parties making the sale of such articles to such dealer, and in such case said party or parties shall be amenable to the prosecutions, fines, and other penalties which would attach, in due course, to the dealer under the provisions of this Act. Sec. id. That any article of food, drug, or liquor that is adulterated or misbranded within the meaning of this Act, and is being transported from one State, Territory. District, or insular possession to another for sale, or, having been transported, remains unloaded, unsold, or in original unbroken packages, or if it be sold or offered for sale in the District of Columbia or the Territories, or insular possessions of the United States, or if it be imported from a foreign country for sale, or if it is intended for export to a foreign country, shall be liable to be proceeded against in any district court of the United States within the district where the same is found, and seized for confiscation by a process of libel for condemnation. And if such article is condemned as being adulterated or misbranded, or of a poisonous or deleterious character, within the meaning of this Act, the same shall be disposed of by destruc- tion or sale, as the said court may direct, and the proceeds thereof, if sold, less the legal costs and charges, shall be paid into the Treasury of the United States, but such goods shall not be sold in any jurisdiction contrary to the provisions of this Act or the laws of that jurisdiction: Provided however, That upon the payment of the costs of such libel pro- ceedings and the execution and delivery of a good and sufficient bond to the effect that such articles shall not be sold or otherwise disposed of contrary to the provisions of this Act, or the laws of any State, Territory, District, or insular possession, the court may by order direct that such articles be delivered to the owner thereof. The proceedings of such libel APPENDIX. 969 cases shall conform, as near as may be, to the proceedings in admiralty, except that either party may demand trial by jury of any issue of fact joined in any such case, and all such proceedings shall be at the suit of and in the name of the United States. Sec. II. The Secretary of the Treasury shall deliver to the Secretary of Agriculture, upon his request from time to time, samples of foods and drugs which are being imported into the United States or offered for import, giving notice thereof to the owner or consignee, who may appear before the Secretary of Agriculture, and have the right to introduce testimony, and if it appear from the examination of such samples that any article of food or drug offered to be imported into the United States is adulterated or misbranded within the meaning of this Act, or is otherwise dangerous to the health of the people of the United States, or is of a kind forbidden entry into, or forbidden to be sold or restricted in sale in the country in which it is made or from which it is exported, or is otherwise falsely labeled in any respect, the said article shall be refused admission, and the Secretary of the Treasury shall refuse delivery to the consignee and shall cause the destruction of any goods refused delivery which shall not be exported by the consignee within three months from the date of notice of such refusal under such regulations as the Secretary of the Treasury may pre- scribe: Provided, That the Secretary of the Treasurv may deliver to the consignee such goods pending examination and decision in the matter on execution of a penal bond for the amount of the full invoice value of such goods, together with the duty thereon, and on refusal to return such goods for any cause to the custody of the Secretary of the Treasury, when demanded, for the purpose of excluding them from the country, or for any other purpose, said consignee shall forfeit the full amount of the bond: And provided further, That all charges for storage, cartage, and labor on goods which are refused admission or delivery shall be paid by the owner or consignee, and in default of such payment shall constitute a lien against any future importation made by such owner or consignee. Sec. 12. That the term " Territory " as used in this Act shall include the insular pos- sessions of the United States. The word " person " as used in this Act shall be construed to import both the plural and the singular, as the case demands, and shall include corpora- tions, companies, societies and associations. When construing and enforcing the provisions of this Act, the act, omission, or failure of any officer, agent, or other person acting for or employed by any corporation, company, society, or association, within the scope of his employment or office, shall in every case be also deemed to be the act, omission, or failure of such corporation, company, society, or association as well as that of the person. Sec. 13. That this Act shall be in force and effect from and after the first day of January, nineteen hundred and seven. THE MEAT-INSPECTION LAW. Extract from an act of Congress entitled " An act making appropriations for the Department of Agriculture for the fiscal year ending June thirtieth, nine- teen hundred and seven," approved June 30, 1906. That for the purpose of preventing the use in interstate or foreign commerce, as herein- after provided, of meat and meat food products which are unsound, unhealthful, unwhole- some, or otherwise unfit for human food, the Secretary of Agriculture, at his discretion, may cause to be made, by inspectors appointed for that purpose, an examination and inspection of all cattle, sheep, swine, and goats before they shall be allowed to enter into any slaughtering, packing, meat-canning, rendering, or similar establishment, in which they are to be slaughtered and the meat and meat food products thereof are to be used in inter- state or foreign commerce; and all cattle, swine, sheep, and goats found on such inspection to 970 FOOD INSPECTION yIND yiN^ LYSIS. show symptoms of disease shall be set apart and slaughtered separately from all other cattle, sheep, swine, or goats, and when so slaughtered the carcasses of said cattle, sheep, swine, or goats shall be subject to a careful examination and inspection, all as provided by the rules and regulations to be prescribed by the Secretary of Agriculture as herein provided for. That for the purposes hereinbefore set forth the Secretary of Agriculture shall cause to be made by inspectors appointed for that purpose, as hereinafter provided, a post-mortem examination and inspection of the carcasses and parts thereof of all cattle, sheep, swine, and goats to be prepared for human consumption at any slaughtering, meat-canning, salt- ing, packing, rendering, or similar establishment in any State, Territory, or the District of Columbia for transportation or sale as articles of interstate or foreign commerce, and the carcasses and parts thereof of all such animals found to be sound, healthful, wholesome, and fit for human food shall be marked, stamped, tagged, or labeled as " Inspected and Passed;" and said inspectors shall label, mark, stamp, or tag as " Inspected and Con- demned," all carcasses and parts thereof of animals found to be unsound, unhealthful, unwholesome, or otherwise unfit for human food; and all carcasses and parts thereof thus inspected and condemned shall be destroyed for food purposes by the said establishment in the presence of an inspector, and the Secretary of Agriculture may remove inspectors from any such establishment which fails to so destroy any such condemned carcass or part thereof, and said inspectors, after said first inspection shall, when they deem it necessary, reinspect said carcasses or parts thereof to determine whether since the first inspection the same have become unsound, unhealthful, unwholesome, or in any way unfit for human food, and if any carcass or any part thereof shall, upon examination and inspection subse- quent to the first examination and inspection, be found to be unsound, unhealthful, unwhole- some, or otherwise luifit for human food, it shall be destroyed for food purposes by the said establishment in the presence of an inspector, and the Secretary of Agriculture may remove inspectors fr^m any establishment which fails to so destroy any such condemned carcass or part thereof. The foregoing provisions shall apply to all carcasses or parts of carcasses of cattle, sheep, swine, and goats, or the meat or meat products thereof which may be brought into any slaughtering, meat-canning, salting, packing, rendering, or similar establishment, and such examination and inspection shall be had before the said carcasses or parts thereof shall be allowed to enter into any department wherein the same are to be treated and pre- pared for meat food products; and the foregoing provisions shall also apply to all such products which, after having been issued from any slaughtering, meat-canning, salting, packing, rendering, or similar establishment, shall be returned to the same or to any similar establishment where such inspection is maintained. That for the purposes hereinbefore set forth the Secretary of Agriculture shall cause to be made by inspectors appointed for that purpose an examination and inspection of all meat food products prepared for interstate or foreign commerce in any slaughtering, meat-canning, salting, packing, rendering, or similar establishment, and for the purposes of any examination and inspection said inspectors shall have access at all times, by day or night, whether the establishment be operated or not, to every part of said establishment; and said inspectors shall mark, stamp, tag, or label as " Inspected and Passed " all such products found to be sound, healthful, and wholesome, and which contain no dyes, chemicals, preservatives, or ingredients which render such meat or meat food products unsound, unhealthful, unwholesome, or unfit for human food; and said inspectors shall label, mark, stamp, or tag as " Inspected and Condemned " all such products found unsound, unhealth- ful, and unwholesome, or which contain dyes, chemicals, preservatives, or ingredients which render such meat or meat food products unsound, unhealthful, unwholesome, or unfit for human food, and all such condemned meat food products shall be destroyed for food pur- /1PPEND1X. 971 poses, as hereinbefore provided, and the Secretary of Agriculture may remove inspectors from any establishment which fails to so destroy such condemned meat food products: Provided, That, subject to the rules and regulations of the Secretary of Agriculture, the pro- visions hereof in regard to preservatives shall not apply to meat food products for export to any foreign country and which are prepared or packed according to the specifications or directions of the foreign purchaser, when no substance is used in the preparation or packing thereof in conflict with the laws of the foreign countrj' to which said article is to be exported; but if said article shall be in fact sold or offered for sale for domestic use or consumption, then this proviso shall not exempt said article from the operation of all the other provisions of this act. That when any meat or meat food product prepared for interstate or foreign com- merce v/hich has been inspected as hereinbefore provided and marked " Inspected and Passed " shall be placed or packed in any can, pot, tin, canvas, or other receptacle or cover- ing in any e3tablishment where inspection under the provisions of this act is maintained, the person, firm, or corporation preparing said product shall cause a label to be attached to said can, pot, tin, canvas, or other receptacle or covering, under the supervision of an inspector, which label shall state that the contents thereof have been " Inspected and Passed " under the provisions of this act; and no inspection and examination of meat or meat food products deposited or inclosed in cans, tins, pots, canvas, or other receptacle or covering in any establishment where inspection under the provisions of this act is maintained shall be deemed to be complete until such meat or meat food products have been sealed or inclosed in said can, tin, pot, canvas, or other receptacle or covering under the supervision of an inspector, and no such meat or meat food products shall be sold or offered for sale by any person, firm, or corporation in interstate or foreign commerce under any false or deceptive name; but established trade name or names which are usual to such products and which are not false and deceptive and which shall be approved by the Secretary of Agriculture are permitted. The Secretary of Agriculture shall cause to be made, by experts in sanitation or by other competent inspectors, such inspection of all slaughtering, meat-canning, salting, packing, rendering, or similar establishments in which cattle, sheep, swine, and goats are slaughtered and the meat and meat food products thereof are prepared for interstate or foreign commerce as may be necessary to inform himself concerning the sanitary conditions of the same, and to prescribe the rules and regulations of sanitation under which such establishments shall be maintained; and where the sanitary conditions of any such establishment are such that the meat or meat food products are rendered unclean, unsound, unhealthful, unwholesome, or otherwise unfit for human food, he shall refuse to allow said meat or meat food pioducts to be labeled, marked, stamped, or tagged as " Inspected and Passed." That the Secretary of Agriculture shall cause an examination and inspection of all cattle, sheep, swine, and goats, and the food products thereof, slaughtered and prepared in the establishments hereinbefore described for the purposes of interstate or foreign commerce to be made during the nighttime as well as during the daytime when the slaughtering of said cattle, sheep, swine, and goats, or the preparation of said food products is conducted during the nighttime. That on and after October first, nineteen hundred and six, no person, firm, or corpora- tion shall transport or offer for transportation, and no carrier of interstate or foreign commerce shall transport or receive for transportation from one State or Territory or the District of Columbia to any other State or Territory or the District of Columbia, or to any place under the jurisdiction of the United States, or to any foreign country, any carcasses or parts thereof, meat, or meat food products thereof which have not been inspected, examined, and marked as " Inspected and Passed," in accordance with the terms of this act and with the rules and 972 FOOD INSPECTION /1ND ANAL YSIS. regulations prescribed by the Secretary of Agriculture: Provided, That all meat and meat food products on hand on October first, nineteen hundred and six, at establishments where inspection has not been maintained, or which have been inspected under existing law, shall be examined and labeled under such rules and regulations as the Secretary of Agriculture shall prescribe, and then shall be allowed to be sold in interstate or foreign commerce. That no person, firm, or corporation, or officer, agent, or employee thereof, shall forge, counterfeit, simulate, or falsely represent, or shall without proper authority use, fail to use, or detach, or shall knowingly or wrongfully alter, deface, or destroy, or fail to deface or destroy, any of the marks, stamps, tags, labels, or other identification devices provided for in this act, or in and as directed by the rules and regulations prescribed hereunder by the Secretary of Agriculture, on any carcasses, parts of carcasses, or the food product, or containers thereof, subject to the provisions of this act, or any certificate in relation thereto, authorized or required by this act or by the said rules and regulations of the Secretary of Agriculture. That the Secretary of Agriculture shall cause to be made a careful inspection of all cattle, sheep, swine, and goats intended and offered for export to foreign countries at such times and places, and in such manner as he may deem proper, to ascertain whether such cattle, sheep, swine, and goats are free from disease. And for this purpose he may appoint inspectors who shall be authorized to give an official certificate clearly stating the condition in which such cattle, sheep, swine, and goats are found. And no clearance shall be given to any vessel having on board cattle, sheep, swine, or goats for export to a foreign country until the owner or shipper of such cattle, sheep, swine, or goats has a certificate from the inspector herein authorized to be appointed, stating that the said cattle, sheep, swine, or goats are sound and healthy, or unless the Secretary of Agriculture shall have waived the requirement of such certificate for export to the particular country to which such cattle, sheep, swine, or goats are to be exported. That the Secretary of Agriculture shall also cause to be iriade a careful inspection of the carcasses and parts thereof of all cattle, sheep, swine, and goats, the meat of which, fresh, salted, canned, corned, packed, cured, or otherwise prepared, is intended and offered for export to any foreign country, at such times and places and in such manner as he may deem proper. And for this purpose he may appoint inspectors who shall be authorized to give an official certificate stating the condition in which said cattle, sheep, swine, or goats, and the meat thereof, are found. And no clearance shall be given to any vessel hav-ing on board any fresh, salted, canned, corned, or packed beef, mutton, pork, or goat meat, being the meat of animals killed after the passage of this act, or except as hereinbefore provided for export to and sale in a foreign country from any port in the United States, until the owner or shipper thereof shall obtain from an inspector appointed under the provisions oi this act a certificate that the said cattle, sheep, swine, and goats were sound and healthy at the time of inspection, and that their meat is sound and wholesome, unless the Secretary of Agriculture shall have waived the requirements of such certificate for the country to which said cattle, sheep, swine and goats or meats are to be exported. That the inspectors provided for herein shall be authorized to give ofikial certificates of the sound and wholesome condition of the cattle, sheep, swine, and goats, their carcasses and products as herein described, and one copy of every certificate granted under the pro- visions of this act shall be filed in the Department of Agriculture, another copy shall be delivered to the owner or shipper, and when the cattle, sheep, swine, and goats or their carcasses and products are sent abroad, a third copy shall be delivered to the chief officer of the vessel on which the shipment shall be made. APPENDIX. 973: That no person, firm, or corporation engaged in the interstate commerce of meat or meat food products shall transport or offer for transportation, sell or offer to sell any such meat or meat food products in any State or Territory or in the District of Columbia or any place under the jurisdiction of the United States, other than in the State or Territory or in the District of Columbia or any place under the jurisdiction of the United States in which the slaughtering, packing, canning, rendering, or other similar establishment owned, leased, operated by said firm, person, or corporation is located unless and until said person, firm, or corporation shall have complied with all of the provisions of this act. That any person, firm, or corporation, or any officer or agent of any such person, firm, or corporation, who shall violate any of the provisions of this act shall be deemed guilty of a misdemeanor, and shall be punishe;d on conviction thereof by a fine of not exceeding ten thousand dollars or imprisonment for a period not more than two years, or by both such fine and imprisonment, in the discretion of the court. That the Secretary of Agriculture shall appoint from time to time inspectors to make examination and inspection of all cattle, sheep, swine, and goats, the inspection of which is hereby provided for, and of all carcasses and parts thereof, and of all meats and meat food products thereof, and of the sanitary conditions of all establishments in which such meat and meat food products hereinbefore described are prepared; and said inspectors shall refuse to stamp, mark, tag, or label any carcass or any part thereof, or meat food product. therefrom, prepared in any establishment hereinbefore mentioned, until the same shall have actually been inspected and found to be sound, healthful, wholesome, and fit for human food, and to contain no dyes, chemicals, preservatives, or ingredients which render such meat food product unsound, unhealthful, unwholesome, or unfit for human food; and to have been prepared under proper sanitary conditions, hereinbefore provided for; and shall perform such other duties as are provided by this act and by the rules and regulations to be prescribed by said Secretary of Agriculture; and said Secretary of Agriculture shall, from time to time, make such rules and regulations as are necessary for the efficient execution of the provisions of this act, and all inspections and examinations made under this act shall be such and made in such manner as described in the rules and regulations prescribed by said Secretary of Agriculture not inconsistent with the provisions of this act. That any person, firm, or corporation, or any agent or employee of any person, firm, or corporation, who shall give, pay, or offer, directly or indirectly, to any inspector, deputy inspector, chief inspector, or any other officer or employee of the United States authorized to perform any of the duties prescribed by this act or by the rules and regulations of the Secretary of Agriculture any money or other thing of value, with intent to influence said inspector, deputy inspector, chief inspector, or other officer or employee of the United States in the discharge of any duty herein provided for, shall be deemed guilty of a felony and, upon conviction thereof, shall be punished by a fine not less than five thousand dollars nor more than ten thousand dollars and by imprisonment not less than one year nor more than three years; and any inspector, deputy inspector, chief inspector, or other officer or employee of the United States authorized to perform any of the duties prescribed by this act who shall accept any money, gift, or other thing of value from any person, firm, or corporation, or officers, agents, or employees thereof, given with intent to influence his official action, or who shall receive or accept from any person, firm, or corporation engaged in interstate or foreign commerce any gift, mone}', or other thing of value given with any purpose or intent what- soever, shall be deemed guilty of a felony and shall, upon conviction thereof, be summarily discharged from office and shall be punished by a fine not less than one thousand dollars nor more than ten thousand dollars and by imprisonment not less than one year nor more than three years. That the provisions of this act requiring inspection to be made by the Secretary of 974 FOOD INSPECTION AND ANALYSIS. Agriculture shall not apply to animals slaughtered by any farmer on the farm and sold and transported as interstate or foreign commerce, nor to retail butchers and retail dealers in meat and meat food products, supplying their customers: Provided, That if any person shall sell or offer for sale or transportation for interstate or foreign commerce any meat or meat food products which are diseased, unsound, unhealthful, unwholesome, or otherwise unfit for human food, knowing that such meat food products are intended for human consump- tion, he shall be guilty of a misdemeanor, and on conviction thereof shall be punished by a fine not exceeding one thousand dollars or by imprisonment for a period of not exceeding one year, or by both such fine and imprisonment: Provided also, That the Secretary of Agri- culture is authorized to maintain the inspection in this act provided for at any slaughtering, meat canning, salting, packing, rendering, or similar establishment notwithstanding this exception, and that the persons operating the same may be retail butchers and retail dealers or farmers; and where the Secretary of Agriculture shall establish such inspection then the provisions of this act shall apply notwithstanding this exception. That there is permanently appropriated, out of any money in the Treasury not other- wise appropriated, the sum of three million dollars, for the expenses of the inspection of cattle, sheep, swine, and goats and the meat and meat food products thereof which enter into interstate or foreign commerce and for all expenses necessary to carry into effect the provisions of this act relating to meat inspection, including rent and the employment of labor in Washington and elsewhere, for each year. And the Secretary of Agriculture shall, in his annual estimates made to Congress, submit a statement in detail, showing the number of persons employed in such inspections and the salary or per diem paid to each, together with the contingent expenses of such inspectors and where they have been and are employed. INDEX. Abbe refractometer, loo, io8 construction, log influence of temperature, no manipulation, 109 Abrastol, 837 Absinthe, 754 Acetanilide in vanilla extract, 858 tests for, 859 Acetyl value, 497 Achroodextrine, 575 Acid fuchsin, 799 brown, 810 green, 794 magenta, 816, 817 yellow, 794, 818 Acids, fatty, 481, 484, 499, 500 of acetic series, 471 of linoleic series, 472 of oleic series, 472 mineral, in vinegar, 767 organic, 47, 941, 949 Ackermann and Steinmann's table for • alcohol from refraction, 715 Ackermann's table for extract from refrac- tion, 721 Adams' fat method, 134 " Aerated " butter, 540 Agar agar, in jelly, 934, 943 Aging of liquors, 731, 732 Albumin, acid, 44 alkali, 44 determination in milk, 146 of muscle, 211 preparation of, 263 Albuminoids, 42 Albumins, 41, 297 Albumose, 44, 45 Alcohol, detection, 657 determination, 658 by distillation, 658 by ebulioscope, 675 by evaporation, 660 from refraction, 715 from specific gravity, 658, 659 Alcohol, extract of spices, 470 in malt liquors, 715 methyl-, 749, 878 preparation of, 730 stills, 659 tables, 661-674 Alcoholic beverages, 653, 654. See also Liquors, references on, 756 state control of, 654 toxic effect of, 655 fermentation, 653 Aldehydes, determination, 745 Ale, 709, 712. See also Beer. ginger, 954 Aleurone, 90 Alizarin, 804 Alkaloidal nitrogen, 40, 46 Alkaloids, proof of absence of, 726 Alkanna tincture, 92 Allantoin, 299 AUen-Marquardt method for fusel oil, 747 Allihn's sugar method, 608 tables, 609 Allspice, 420 adulteration, 424 composition of, 420 microscopical structure, 422 standard, 424 tannin in, 421 Almond extract, 884 adulteration of, 886 alcohol in, 888 benzaldehyde in, 886, 888 hydrocyanic acid in, 888, 889 nitro benzol in, 887, 888 standards, 885 meal, 358 Almonds, bitter, oil of, 884, 885 Alum in baking powder, ^;^^, 344 in bread, 326 in flour, 315 in pickles, 926 975 976 INDEX. Alumina, determination of, 344 Aluminum salts in baking powder, 344 in cream of tartar, 344 Amagat and Jean's refractometer, 100 Amaranth, 794, 806, 815, 816, 817 Amides, 45 in milk, 147 Amido nitrogen determination, 74, 147 in wheat; 299 Amino acids, 40, 45 Ammonia, determination, 74 in baking powder, 346 in foods, 40, 46 in milk, 147 Ammonium fluoride, 835 Amthor test for caramel, 752 Amylodextrin, 575 Amyloid, 91, 92 Analyst, functions of, 3, 4 Angostura, 754 Anilin orange, 808 in milk, 177 Animal diastase, 284 Anise extract, standards, 892 oil, standards, 892 Annatto in butter, 536, 537 in milk, 175, 177 tests for, 791, 810 Antiseptics, see Preservatives. Apparatus, 20 Apple butter, 927 essence, imitation, 896, 897 juice, 680 pulp, detection, 943 Apples, composition of, 274, 275 Araban, 285, 288 Arabinose, 285, 288 Arata's color test, 796 Army rations, 257 Arsenic detection and determination, 74 compounds in colors, 785 in baking chemicals, 346 in beer, 713, 728 in confectionery, 649 in glucose, 633 in vinegar, 780 Johnson-Chittenden-Gautier meth- od, 74 Marsh apparatus, 75 Sanger-Black-Gutzeit test for, 76 Artificial colors, 782 fruit essences, 895, 897 sweeteners, 850 references on, 855 Asaprol, 845 Asbestos fiber, preparation of, 594, 598 Ash analysis, scheme for, 301 determination of, 62 of food, 47 Asparagin, 45, 299 Auramin, 784, 803 Aurantia, 801 Aurin, 804 Azo blue, 801, 812, 816 Azoacidrubine, 794 Babcock asbestos milk fat method, 135 milk sohds method, 134 centrifugal fat method, 136 milk formulae, 153 test bottles, 138 Bacon formic acid method, 841, 843 Bacon and Dunbar citric acid method, 923 lactic acid method, 923 Baier and Neuman's test for sucrose in milk 197 Baker tin method, 917 Baking powders, 332 adulteration of, 334 alum, 7,2,2,, 334 methods of analysis, 336 phosphate, 334 tartrate, 332 Balances, 20 Bamihl test for gluten, 322 Banana essence, artificial, 896, 897 Barium compounds in colors, 784 Bark as an adulterant, 428 Barley, 271, 272 ash, 302 microscopy of, 309 proteins, 300 starch, 281 Bar wood, 808 Basic colors, 795, 798 Baudouin's sesame oil test, 519 Beading oil, 738 Beans, 272, 388 Bechi's cottonseed oil test, 517 Beckman's test for glucose in honey, 641 Beef, composition of, 213 cuts of, 213 stearin, microscopical structure, 558 tallow, 529 Beer, 707 acids in, 724 adulteration of, 711 alcohol in, 715 aloes in, 727 arsenic in, 713, 728 ash of, 714 birch, 954 INDEX. 977 Beer, bitter principles of, 726 bock-, 709 brewing of, 708 carbon dioxide in, 726 chiretta in, 711, 727 composition of, 709 degree of fermentation of, 724 dextrin in, 724 extract gravity of, 722 extract in, 715 specific gravity method, 722 refractometer method, 722 gentian bitter in, 711, 727 glucose in, 710 glycerin in, 724 lager-, 708 methods of analysis, 714 phosphoric acid in, 725 preservatives in, 713, 729 proteins of, 725 quassiin in, 711, 727 references on, 756 root, 954 schenk-, 708 standards, 711 temperance-, 714 varieties of, 708 uno-, 714 weiss-, 709 wort, 708 gravity of, 722 Beeswax, 643 refractometer reading of, 645 Beet (color), 790 sugar, 569 Bellier's peanut oil test, 524 Benches, 15 Benedictine, 754 Benzaldehyde, 885, 886, 929 artificial, 885 in almond extract, 886 in maraschino cherries, 929 Benzoic acid, 833 detection of, 834 determination, 835 in milk, 180 toxicity of, 834 Betaine, 45, 299 Beta-naphthol, 845 Beverages, carbonated. See Carbonated beverages. Biebrich scarlet, 806 Bigelow and McElroy's cane-sugar method, 192 Bilberry (color), 790 Birch beer, 954 Birotation, 584, 639 Biscuit, gluten, 358 soja bean, 358 Bishop arsenic apparatus, 76 Bismarck brown, 801, 810 Bisulphites as preservatives, 839 Bitter almonds, oil of, 884, 885 Biuret reaction, 41 Blackberry (color), 790 Blarez test for fluorides, 843 Blast pump, 19 Blue colors, 785, 786, 788, 794, 812 " Blown " cans, 902 Bock-beer, 709 " Boiled " butter, 540 Bombay mace, 467 Bomb calorimeter, 47 Bomer's phytosterol acetate test, 507 Borax, 827 Bordeaux B, 801, 806 s, 704 Boric acid, 827 detection, 182, 184, 828 determination, 827, 829 in butter, 538 in meat, 220, 232 in milk, 182, 184 Bourbon whiskey, 732, 734, 737 Brandy, 739 adulteration of, 741 composition of, 739 " drops," 649 methods of analysis, 745 new, 740 potable, 740 standards, 740 Brazil wood, 790, 808 Bread, 317, 323 acidity of, 325 adulteration of, 326 alum in, 326 baking of, 323 composition of, 324, 325 fat in, 326 Breakfast cereals, 352 Brewing beer, 708 Brie cheese, 202 Brilliant red, 806 yellow, 816 Bromination oil test, 494 Bromine absorption of oils, 492 Brown and Duvel's method for moisture in grain, 278 Brown colors, 786, 788, 810 sugar, 568 Browne's method for dextrin in honey, 640 978 INDEX. Browne's test for invert sugar in honey, 642 Brucke's glycogen method, 236 reagent, 236 Buckwheat, 271 ash of, 302 composition of, 271, 272 flour, 313 microscopy of, 311 Burgundy wine, artificial, 692 Butter, 201, 529 adulteration of, 535 annatto in, 536 apple, 927 ash in, 534 azo colors in, 536, 537 boric acid in, 538 carrotin in, 536 casein in, 534, 551 coloring in, 535 composition of, 530 distinction from oleomargarine and process butter, 546 effects of feeding, 531 fat, composition of, 530 standard, 535 fat in, 533, 534 filled, 540 foam test, 549 formaldehyde in, 539 fruit, 927 glucose in, 539 methods of analysis, 531 microscopical examination of, 552 milk test, 550 preservatives in, 538 references on, 562 renovated, 540 salicylic acid in, 539 salt in, 534 standard, 535 sulphurous acid in, 539 turmeric in, 536 water in, 531 Waterhouse test, 550 Butterine, 541 Butterine oil, 522 Butyro-refractometer, 100, loi critical line of, 106 limits of butter readings, 547 manipulation, 102 oil readings on, 478, 479 olive and cottonseed oil readings, 514 sliding scale for, 107 special thermometer for, 549 table of equivalent refractive indices, 104, 105 Butyro-refractometer, temperature variation of reading, 107 testing scale, 104 Caffeine, 372, 955 determination of, 373, 384, 958, 960 in carbonated beverages, 955 in cocoa, 400 Caffeol, 379 Caffetannic acid, 379, 382 Cake, 327 Calcium carbonate crystals, 90 oxalate crystals^^po sucrate, 196 California wines, 688 Calorie, 47, 48 Calorimeter, bomb, 47 oil, 495 respiration, 2 Camembert cheese, 202 Camera, 96 Canada balsam, 86 Candy, see Confectionery. standard, 645 Cane sugar, 566 ash of, 567 composition of, 568 detection of, 585 in milk, 197 determination of: by copper reduction, 590, 612 by polarimetry, 586, 614 in cereals, 295 inversion of, 588, 589 manufacture of, 567 methods of analysis, 585 moisture in, 586 quotient of purity, 586 refining, 570 test for, 585 Canned food, 900 composition of, 902 decomposition of, 902 metallic impurities in, 904 method of canning, 900 methods of analysis, 913 preservatives in, 912 references on, 961 Canned fruits, 900, 902 meats, 22 vegetables, 900, 902 Cans, detection of spoiled, 902 gases from spoiled, 903 Capers, 926 Capsicin, 440 INDEX, 979 Capsicums, 439 Caramel, 792 in distilled liquors, 752 in milk, 176, 177 in vanilla extract, 869 in vinegar, 779 Carbohydrates, 46, 47, 74, 279 of cereals, 279, 295 of eggs, 263 Carbon dioxide in baking chemicals, 336 in beer, 726 in yeast, 330 Carbonated beverages 952 acids in, 955 bottled, 954 caffein in, 958 cocaine in, 959 colors in, 955 foam producers in, 955 habit- forming drugs in, 955 methods of analysis, 956 preservatives in, 955 saponin in, 956 sweeteners in, 954 syrups for, 955 water, 953 Carmosin, 806 Carnin, 211 Carrot (color), 791 Casein, 43 125, 126 determination in milk, 145 Caseose, 44 in cheese, 203 in milk, 146 Casoid flour, 358 Cassia, 424 adulteration of, 428 buds, 425 composition of, 422 extract, standards, 892 microscopical structure, 426 oil, 425, 892 standards, 892 standard, 428 Catsup, see Ketchup. Cayenne, 439 adulteration of, 443 coal-tar colors in, 444 colors in, 444 composition of, 441 microscopical structure, 441 mineral adulterants in, 444 oil of, 440 Cayenne, redwood 'n, 444 standard, 443 Cazeneuvc's color scheme, 705, 706 Celery seed extract, standards, 892 oil, standards, 892 Cellulose, 47, 285 Centrifuge, milk-fat, 136, 137 Centrifuge, universal, 25 Cereal products, microscopy of, 305 Cereals, 271 ash of, 302 breakfast foods, 352 cane sugar in, 295 carbohj^drates of, 279 separation of, 295 composition of, 271 crude fiber in, 277, 296 dextrin in, 295 hemicelluloses in, 296 methods of proximate analysis, 276 pentosans in, 285, 296 proteins of, 296 references on, 361 starch determination in, 283, 296 Chace total aldehyde method, 875 Champagne, 687 Chaptalizing, 693 Charlock, 459 detection, 460 Chartreuse, 745 Cheddar cheese, 202 Cheese, 202 adulteration of, 203 amides in, 206 ammonia in, 206 ash in, 205 composition of, 202, 203 cream, 203 fat in, 205, 207 filled, 204 lactic acid in, 207 methods of analysis, 204 milk sugar in, 207 nitrogen compounds of, 206 paranuclein in, 206 peptones in, 206 proteins in, 205 sampling, 204 skimmed milk, 203, 204 standards, 203 varieties of, 202 water in, 204 whole milk, 203 Cherries, maraschino, 928 Cherry soda, 954 Chicory, 386, 388, 389 980 INDEX. Chili sauce, 919 Chiretta, 727 Chior iodide of zinc, 91 Chloral hydrate, 93 test for charlock, 460 Chlorine in vegetable substances, 305 Chocolate, see Cocoa, milk, 397 composition of, 397 sucrose and lactose in, 3.;'9 Cholesterol, 502 crystallizations of, 504 determination of, 503 distinction from phytosterol, 503 separation of, 503 Cholin, 45, 299 Chromate of lead, 647 Chrome yellow, 810 Chromogenic bacteria, 130 Chrysamin, 801, 810 Chrysoidin yellow, 808 Chrysophenin, 816 Cider, 678 adulteration of, 682 ash of, 682 composition of, 679 fermented, 680 malic acid in, 683 manufacture of, 678 methods of, analysis, 696 references on, 757 sweet, 948 vinegar, 760, 773 watering of, 682 yeast in, 678 Cinnamon, 424 composition of, 425, 426 extract, 892 microscopical structure of, 426 oil, standards, 892 standard, 428 Citral, 881 determination, 877 in carbonated beverages, 955 in fruit juices, 951 Citric acid in fruit products, 920, 923, 941 942, 948, 951 in ketchup, 920, 923 in milk, 126, 127 Citronellal, 881 Citronella oil, 880, 881 Citronin, 794 Clams, 256 Claret wine, 687 Clarifying reagents in microscopy, 92 in sugar analysis, 586, 614 Clerget's formula, 588 Clove extract, 892 oil, 892 Cloves, 412 adulteration of, 418 cocoanut shells in, 419 composition of, 414 exhausted, 418 microscopical structure, 416 * oil of, S92 standard, 418 stems, 417 tannin in, 415 Clupein, 43 Coal-tar colors, 793 acid, 798 Mathewson method of determination, 814 allowed, 794 Price method of identification, 814 Arata's test, 796 basic, 795 classification, 793, 800 detection of, 795 double dyeing method, 796 dyeing wool by, 795 extraction by amyl alcohol, 797 identification of, 795, 799, 801, 80s in milk, 177 in sausages, 239 Rota's scheme for, 799 separation with ether, 798 Sostegni and Carpentieri's color test, 796 Cocaine, detection of, 959, 960 in carbonated beverages, 955 Cochineal, 792, 808 in sausages, 238 red, 806 Cocoa, 392, 393 adulteration of, 402 alkali in, 403 ash of, 396 butter, 393, 529 cafJeine in, 400 composition of, 393 foreign fat in, 402 manufacture of, 393 methods of, analysis, 398 microscopical structure, 403 nibs, 394, 402 nitrogeneous bodies in, 396 pentosans in, 396 INDEX. 981 Cocoa, references on, 406 shells, 394, 395, 405 standards, 402 starch in, 394, 395, 399, 405 sugar in, 399, 405 theobromine in, 396, 400 Cocoanut oil, 528 pulp, 528 shells, 419 Coffee, 379 adulteration of, 384 ash of, 380, 382 caffeine in, 380, 384 caffeol in, 379 caffetannic acid in, 379, 382 chicory in, 388, 389 coloring of, 384 composition of, 379, 380, 381 essential oil of, 379 fat in, 379 glazing of, 385 hygienic, 390 methods of analysis, 382 microscopical structure, 386 " pellets," 384 references on, 406 standards for, 384 starch in, 386 substitutes, 392 Cognac, 739. See also Brandy. oil, 741 Collagen, 42, 211 Collodion silk, 705 Colorimeter, Schreiner's, 77 Colorometric analysis, 77 Colors, acid fuchsin, 799 artificial, 782 allowed, 794 animal, 792 arsenic compounds, 785 barium compounds, 784 basic, 795 blue, 785, 786, 788, 794, 812 brown, 786, 788, 810 caramel, 792 coal tar, 793, 794, 795 cochineal, 792 copper compounds, 784 cudbear, 791 extraction of, by immiscible sol- vents, 797 fuchsin, 800, 806 green, 785, 786, 787, 794, 812 harmless, 784, 786 identification of, 795, 799, 805 in butter, 535 Colors, in carbonated beverages, 955 in cayenne, 444 in confectionery, 649, 784, 788 indigo, 792, 812 in jams and jellies, 942 injurious, 784, 785 in ketchup, 921 in milk, 174-177 in mustard, 460 in sugar, 590 lead chromate, 647, 784, 793 lead compounds, 784 logwood, 791 mercury compounds, 785 mineral, 792 non-injurious, 784, 786 orange, 785, 794, 808 orchil, 791 Prussian blue, 375, 792, 812 reagents for identifying, 814 red, 785, 786, 790, 806 references on, 819 Rota's scheme for, 799 separation by solvents, 797, 814 toxic effect of, 783 turmeric, 791 ultramarine blue, 793, 812 vegetable, 789, 791, 797 violet, 786, 789, 812 wool dyeing, 795, 796 yellow, 785, 787, 790, 794, 808 Colostrum, 129 Commercial glucose, see Glucose. Compressed yeast, 328 Conalbumin, 262 Concentrated foods, 257 Condensed milk, 186 as a milk adulterant, i^ ash of, 189 cane sugar in, 191, 192 composition of, 187 fat in, 189, 191, 192 foreign fats in, 191 milk sugar in, 190 methods in analysis, 18 proteins in, 190, 192 soUds of, 188 standards for, 188 Confectionery, 645 adulteration of, 645 alcohol in, 649 arsenic in, 649 cane sugar in, 648 colors in, 645, 647 dextrin in, 648 glucose in, 648 982 INDEX. Confectionery, invert sugar in, 648 lead chromate in, 647 methods of analysis, 646 mineral adulterants, 646 paraffin in, 647 starch in, 648 Congo red, 801, 806, 816 Connective tissue, 211 Copper salts, 909 determination of, 914, 918 in vinegar, 780 Copra oil, 528 Cordials, 754 analysis of, 755 composition of, 755 Corky tissue, 89 Corn, 271, 272 ash of, 302 bleaching of canned, 912 composition of, 271, 272 microscopical structure, 309 oil, 521 sitosterol in, 522 proteins of, 300 starch, 281 syrup, 575 Cornelison's butter color test, 537 Corning of meat, 219 Cotton scarlet 3 B, 816 Cottonseed, 516 oil, 516 standards for, 517 tests for, 517 stearin, 517 Cotton's cane sugar method, 185 Coumarin, 862 determination, 865 microscopical structure, 867 Crampton and Simon's caramel test, 752 palm oil tests, 542 Cream, 193 adulteration of, 194 cheese, 202 evaporated, 194 fat in, 195 foreign fats in, 194, 196 gelatin in, 195, 196 methods of analysis, 195 standards for, 194 sucrate of lime in, 195, 197 test scale, 194 viscogen in, 195, 197 Cream of tartar, 336 in wine, 702 methods of analysis, 336 Creatin, 46, 211 Creatinin, 46, 211 Creme de menthe, 755 Creme de Noyau, 754 Crocein orange, 810, 816 scarlet, 806 Crude fiber, 277 in cereals, 296 Crustaceans, 256 Crystals, plant, 90 Cucumber pickles, 925 Cudbear, 791, 808 Cumidin red, 794 , 806 ponceau, 794 Cuprammonia, 93 Ciiragoa, 754 Curcuma, 450 Curcumin, 451 Curd tests in butter, 551, 552, 553 Curing meat, 219 Currant (color), 790 black (color), 790 Curry powder, 450 Custard powders, 270 Dakota mustard, 460 Date stones, 390 Decker-Kunze method for theobromine and caffeine, 400 Defren-O'SuUivan sugar method, 150, 594 Defren's sugar tables, 595 Denis and Dunbar benzaldehyde method, 886 Desiccated egg, 268 Deutyro-albumose, 44, 45 Dextrin, 575 determination of, in cereals, 295 in glucose, 602 in honey, 640 in jams and jel- lies, 940 in molasses, 624 Dextrose, 573 determination of, 591, 593,594, 598 Diabetic foods, 357 analyses, 358 Diamond yellow, 801 Diastase, animal, 284 in malt extract, 729 starch methods, 283 Dietetics, references on, 49 Dinitrocresol, 808 Dioxin, 801 Distilled liquors, 730 aldehydes in, 745 analytical methods, 745 caramel in, 752 color tests, 752, 753 INDEX. 983 Distilled liquors, esters in, 745 extract in, 745 furfural in, 746 fusel oil in, 746 methyl alcohol in, 749 opalescence test, 753 references on, 758 Doolittle and Woodruff theine method, 373 Doolittle butter color test, 537 Double dilution sugar method, 149 Dough, expansion of, 317 Drains, 17 Dried fruits, 944 decomposed, 945 lye treatment of, 945 methods of analysis, 946 moisture content of, 945 sulphuring of, 945 wormy, 945 ■ zinc in, 946 Drugs, habit-forming, 955 Dry wines, 690 Dry yeast, 328 Dubois salicylic acid method, 832 sugar method, 399 Dubosc's saccharimeter, 583 Dulcin, 853 determination, 854 Dunbar and Bacon malic acid method, 949 Dupre's color method, 705 Dvorkovitsch theine method, 373 Ebulioscope, 675 Edam cheese, 202 Edestan, 44 Edestin, 299, 300 Eggs, 261 ash of, 264 carbohydrates of, 263 cold storage, 267 composition of, 264, 265 desiccated, 268 fat of, 264 frozen, 268 lecithin determination, 265 methods of analysis, 265 opened, 268 physical examination of, 267 preservation of, 266 proteins of, 262 references on, 270 substitutes for, 269 waterglass as a preservative, 266 weights of, 264 white of, 262 yolk of, 263 Elaidin oil test, 499 Elastin, 211 Elderberry (color), 790 Electrolytic apparatus, 608 Elm bark, 428 Emergency rations, 257 Eosin, 794, 804, 806 Ergot, 313 Erythrodextrin, 575 Erythrosin, 794, 806, 815, 816, 817 Esters, in distilled liquors, 745 in imitation flavors, 898 Ether, ethyl, preparation of absolute, 66 petroleum, preparation of, for a sol- vent, 66 Eucasin, 158 Eugenol, 412 Ewe's milk, 127 Exhausted cloves, 418 ginger, 450 tea leaves, 375 vanilla beans, 859 Exhaust pump, 20 Extraction with immiscible solvents, 68 volatile solvents, 63 Extractor, Johnson, 55 Soxhlet, 63 " Faints," 732 Farinaceous infants' foods, 356 Fast red, 794, 806, 816 Fat globules, 90 Fat of food, 39 of meat, 226, 227 Fats, edible, 471. See also Oils, filtering, 473 measuring, 473 melting-point of, 480 methods of analysis, 473 microscopical examination of, 510 paraffin in, 510 references on, 561 weighing, 473 Fatty acids, 499 constants of, 500 insoluble, 485 solidifying point of, 500 soluble, 484 volatile, 841 Fehling processes, 590 gravimetric, 150, 593 volumetric, 150, 591 Fehling's solution, 591 equivalents of, 592 Fermentation, acetic, 759 alcohohc, 653 984 INDEX. Fermentation, lactic, 129 proteolytic, 158, 202 Fermented liquors, 678 Feser's lactoscope, 163 Fibrin, 125 Fibro vascular tissue, 88 Fibroin, 42 Filled cheese, 204 Fincke formic acid method, 842 Fish, analyses of, 255 preservatives in, 257 colors in, 257 Flavoring extracts, 857 references on, 898 Flesh foods, 211 references on, 258 Fletcher and Allen's tannin method, 371 Floor, 15 Flour, 311 absorption test of, 317 acidity in, 320 adulteration of, 314 alcohol soluble protein in, 320 alum in, 315 baking tests of, 318 bleaching of, 315 detection, 321 cold water extract of, 320 color test of, 317 composition of, 312 damaged, 313 dough test of, 317 fineness of, 316 gluten in, 320, 322 inspection, 316 iodine number of fat of, 321 methods of analysis, 316 nitrites in, 321 proximate constituents of, 319 salt soluble protein in, 320 Fluoborates, 843, 844 Fluorides, 843 detection of, 843 Fluosilicates, 843, 844 Foam producers, 955 "Foam" test for butter, 549 Folin method for ammonia in meat, 226 Food adulteration, 5 analysis, commercial, 3 from dietetic standpoint, 2 general methods, 4 references on, 79 and drugs act, 965 concentrated, 257 economy, references on, 49 inspection, 3, 6 Food inspection, references on, 11 misbranding, 6 nature and composition of, 39 ofhcial control of, i references on, 11 standards, 4 Fore milk, 128 Foreshots, 732 Formaldehyde, 824 detection of, 180, 824 determination of, 181, 825, 827 in eggs, 268 in milk. 178 Formic acid, 841 detection of, 841 determination of, 842 Fortified wine, 685, 690 Freas drying oven, 22 Fresenius' method for colors in pastes, 350 Frozen milk, test for, 129 meat, 239 Fructose, d-, 574 /-S-, 574 Fruit, 274 butter, 927 candied, 646 composition of, 274 essences, artificial, 895, 896, 897 juices, 946, 947 methods of analysis, 949 methods of proximate analysis, 276 organic acids in, 949 products, 900 references on, 961 references on, 361 sugar, see Levulose. sugar-coated, 646 sugar in, 566 syrups, 952, 953 tissues under the microscope, 944 Fruits, dried, see Dried fruits. Fuchsin, 798, 803, 806 Fuel value, 47 Fuller caffein method, 958, 960 cocaine method, 959, 960 Funnel, jacketed, 474 separatory, 67, 68 Furfural, 285 determination, 746 in distilled liquors, 746 in vinegar, 779 Furnace, electric, 62, 24 gas, 24 Fusel oil, 731 detection, 746 INDEX. pss Fusel oil, determination, Fustic, 790, 810 747 Game, composition of, 216 Gases, in spoiled cans, 903 Geerlig's table for dry substances in sugar products, 615 Geissler's carbon dioxide apparatus, 337 Gelatin, 42, 211 in cream, 195 in jams and jellies, 943 in meat, 231 Gerber's milk centrifuge, 136 Gill and Hatch's oil calorimeter, 495 Gin, 744 Ginger, 445 adulteration of, 450 ale, 954 black, 446 cold water extract of, 448 composition of, 446, 447 exhausted, 447 extract, methods of analysis, 894 standards, 892 liming of, 446 microscopical structure of, 449 oil of, 446 root, 445 standard, 450 white, 446 Gliadin, 42, 298, 299 Globulins, 42, 297 Globulose, 44 Glucin, 855 Glucose, 575 arsenic in, 632 composition of, 576 d-, 573 determination of, in honey, 637, 641 in jams and jellies, 940 in molasses, 621 dextrin in, 632 healthfulness of, 576 in beer, 710, 712 in butter, 539 methods of analysis, 630 standards for, 576 test for, 632, 641 Glucoses, 565 Glutelins, 42 Gluten, 298, 299 Bamihl's test for, 322 biscuit, 358 determination of, 319 flour, 357, 358 Glutenin, 42, 298, 300 Glycerin in carbonated beverages, 960 in vanilla extract, 869 in wine, 703 jelly, 86 Glycerrhizin, 955 Glycogen, 212 detection, 235 determination, 236 Glycoproteins, 43 Goat's milk, 127 Gooch's boric acid method, 830 Gorter caffeine method, 384 Graham flour, 311 Grain, moisture in, 278 Grape juice, 947 Grape sugar, standard, 574 Gray's method for water in butter, 532 Green colors, 785, 786, 787, 794, 812 Groats, 312 Gruyere cheese, 202 Guinea green, 816 Gums, 89 Gunning- Arnold nitrogen method, 432 Gunning nitrogen methods, 69, 71 Gutzeit arsenic test, 76 Habit-forming drugs, 955 Haemoglobins, 43 Haemolysis test for saponin, 957 Halphen cottonseed oil test, 518 Hansen and Johnson tin method, 917 Hanus' iodine absorption method, 491 Hefelmann's Bombay mace test, 467 Hehner and Richmond's milk formula, 151 Hehner's method for insoluble fatty acids, 486 Heidenhain's tartaric acid method, 340 Hemicellulose, 285, 296 Hess and Prescott vanillin and coumaria method, 865 Hetero-albumose, 44, 45 Hiltner's citral method, 877 Hilyer's benzoic acid method, 838 Histones, 43 Hock wine, 689 Hoffmeister's schalchen, 64 Holstein cows, milk from, 162 Homogenized fats, 191, 194, 199 Honey, 633 adulteration of, 636 American, 634 analysis of, 639 Canadian, 634 composition of, 633, 635, 636 dextro-rotatory, 635, 636 European, 633 986 INDEX. Honey, gelatin in, 639 glucose in, 637, 641, 642 Hawaiian, 634 invert sugar in, 638, 642 methods of analysis, 639 Honeydew, 636, 642 Hoods, 1 6, 21 Hops, 708 substitute, 710 Hordein, 42 Horseflesh, characteristics of, 234 composition of, 222 detection of, 235, 237 glycogen in, 235 Horseradish, 920, 927 Hortvet method for acids in wine, 701 number, of maple products, 628 of vinegnr, 768 and West's benzaldchyde method, 887 rose oii method, 895 spice oil method, 893 wintergreen oil method; 890 Hoskins' electric furnace, 63 Howard microscopic ketchup method, 924 test for gums in ice cream, 201 volatile oil method, 874 Hiibl's iodine absorption method, 487 Human milk, 127 Hungarian red pepper, 439, 441, 442 Hunt's iodine reagent, 492 Hydrocyanic acid, 888, 889 Hydrometer, 55 Hypoxanthin, 211 Ice cream, 198 analytical methods, 199 colors in, 201 cones, 199 detection of thickeners, 200 fat in, 199 gelatine in, 201 homogenized, 199 preservatives in, 201 standards, 198 starch in, 201 Imitation coffee, 384 Immersion refractometer, 100, in adjustment of scale, 113 distilled water readings on, 113 investigation of small quantities of solutions by, 115 of solutions excluded from air by, IIS milk examination bv, 166 Immersion refractometer, scale readings compared with «£>, 116 solutions standardized by, 120 references on, 122 temperature corrections for, 121 Incinerator, 173 Indicators, 38 Indices of refraction, 105, 116 Indigo, 792, 812 carmine, 794, 802, 812, 815, 816, 817 disulphosacid, 794, 812 Indigotine, 794, 802 Indol, 92 Indophenol, 802 InduHn, 802, 812 Infants' foods, 354 classification of, 355 cold water extract of, 360 composition of, 356 methods of analysis, 359 microscopical examination of, 360 preparation of, 355 Inosite, 276 Inspection of foods, 3, 5, 6, 9 flour, 316 liquors, 655 rnilk, 159 Inulin, 276 Invalids' foods, 354. See also Infants' Foods. Inversion, 588 Invert sugar, 589 detection of, 589, 625, 642 determination of, 589, 598 in honey, 638, 642 lodeosin, 794 Iodine absorption of oils, 487, 491, 492 Iodine in potassium iodide, 91 Irish whiskey, 732, 734, 735 Jams, 930 acids in, 941, 942 adulteration of, 931, 934 agar agar in, 943 apple stock in, 943 coagulator in, 934 coloring matter in, 942 composition of, 932, 933, 936 compound, 934 dextrin in, 940 fruit tissues in, 944 gelatin in, 943 glucose in, 940 methods of analysis, 936 INDEX. 987 Jams, organic acids in, 941 polarization of, 938 preservatives in, 942 starch in, 943 sugars in, 938 Jellies, see Jams. Johnson extractor, 65 Johnson-Chittenden-Gautier arsenic method, 74 Juckenack's lecithin phosphoric acid method, 349 Kenrick's tartaric acid method, 340 Kephir, 159 Keratins, 42 Ketchup, 919 dtric acid in, 920, 923 colors in, 921 decayed material in, 920 foreign pulp in, 921 lactic acid in, 920, 923 manufacture, 919 methods of analysis, 921 microscopy of, 924,925 organisms in, 924 preservatives in, 921 refuse in, 920 standards, 919 Kjeldahl nitrogen method, 72 Knorr's carbon dioxide apparatus, 338 Koelner's baking test, 318 Koettstorfer's saponification method, 486 Konig and Karach's method for distinguish- ing honeydew and glucose, 642 Koumis, 158 Krober's table for pentosans and pentoses, 288 Laboratory benches, 15 stain for, 16 drains, 17 equipment, 14, 15 references on, 38 floor, 15 hoods, 16 lighting, 15 location, 14 sinks, 17 ventilation, 15 Lactalbumin, 125 Lactated infants' foods, 356 Lactic acid in ketchup, 923 in tomatoes, 920 Lactoglobulin, 125 Lactometer, 131 Lactoscope, 163 Lactose, 125, 577 Defren's table for, 595 detection of, 625 determination of, 593, 594, 598, 626 in milk, 126, 127, 147 Munson and Walker's table for, 599 Soxhlet's table for, 152 Lager beer, 708 Lamb, composition of, 215 cuts of, 215 Landwehr's glycogen method, 236 Lard, 554 adulteration of, 556 back, 554 composition of, 554 composition of as affected by feeding, 560 "compound," 556 constants of, 555 iodine number, 559 kettle-rendered, 554 leaf, 554 microscopical examination of, 557 neutral, 554 oil, 555 references on, 563 standards, 556 stearin, 555 substitutes, 559 Laurent's saccharimeter, 583 Law, food and drugs, 965 meat inspection, 969 La Wall and Bradshaw benzoic acid method, 835 Leach and Lythgoe method for malic value in maple products, 627 methyl alcohol method, 749 Lead chromate, 647, 784, 793 number, maple products, 628 vinegar, 768 salts, of, Q04, 908 determination of, 913, 914, 918 Leavening materials, 327, 332 references on, 364 Lecitalbumin, 43 Lecithin, 46 determination of, 265, 349 nucleovitellin, 43 Lecithoproteins, 43 Leffmann and Beam's method for volatile fatty acids, 482 fat method, 49 Legumelin, 41 Legumes, 272 ash of, 302 Legumin, 42, 300 988 INDEX. Lemon extract, 870 adulteration of, 871 alcohol in, 875 aldehydes in, 875 citral in, 877 citric acid in, 879 colors in, 878 composition of, 870 lemon oil in, 871, 872 methods of analysis, 872 methyl alcohol in, 878 standard for, 870 tartaric acid in, 879 terpeneless, 871 oil, terpeneless, 871 Lemongrass oil, 872, 880, 881 Lemon juice, 948 Lemon oil, 870, 871, 880 alcohol in, 883 aldehydes in, 883 citral in, 882 determination of, 872, 873 examination of, 882 pinene in, 883 soda, 954 Lentils, 272 Leucosin, 41, 299, 300 Levallois' bromine absorption method, 493 Levulose, 574 determination of, 626, 640 Liebig's meat extract, 242 Light green S. F., 794, 812, 815, 816, 817 Lighting, 15 Lignin, 94 Lime, determination of, 303 in baking powder, 345 in spices, 410 juice, 947, 948 sucrate of, 196 water, in vinegar analysis, 765 Liming of ginger, 446 Limonene, 881 Liqueurs, 754 analysis of, 755 Liquor inspection, 655 Liquors, alcohol in, 658, 715 ash of, 677 distilled, 730 methods of analysis, 745 extract of, 677 fermented, 678 malt, 707 methods of analysis, 714 malted and non-malted, 712 methods of analysis, 657 preservatives in, 677 Liquors, specific gravity of, 657 Lobster, composition of, 256 Logwood, 790, 791 Long fermentation baking test, 319 pepper, 438 Lovibond tintometer, 77 Lowenthal's tannin method, 370 Low wines, 732 Lye treatment of fruit, 945 Lythgoe's sucrose test for milk, 197 Macaroni, 347. See also Pastes. Macassar mace, 468 Mace, 462, 465 adulteration of, 466 Bombay, 467 composition of, 465 Macassar, 468 microscopical structure of, 466 standard, 466 Madeira wine, 687 Magenta, 806, 816 Maize, see Corn. Malachite green, 812 Malaga wine, artificial, 692 Malic acid in cider, 702 in fruit juices, 949 in vinegar, 767 in wine, 702 value in maple products, 627 Malt, 707 extracts, 284, 729 liquors, 707. See also Beer. substitutes, 710 vinegar, 762 Malting, 707 Maltose, 574 detection of, 625 determination of, 594, 598, 626 Manganese brown, 810 Maple sap, 570 sugar, 570. See also Maple syrup, syrup, 570 adulteration of, 572 ash of, 571, 572 composition of, 571, 572 Hortvet number of, 628 lead number of, 628 malic acid value, 627 methods of analysis, 627 moisture in, 627 standards, 572 Maraschino, 754 cherries, 928 benzaldehyde in, 929 Mare's milk, 127 INDEX. 989 Marigold, 791 Marpmann's color method, 239 Marsh arsenic test, 75, 728 test for caramel, 753 Martin's color scheme, 535 " Materna " milk modifier, 157 Mathewson color method, 814 Maumene thermal test, 494 Mayrhofer's glycogen method, 237 McGill's drying oven, 586 Meat, 211 ammoniacal nitrogen in, 226 antiseptics in, 220 ash in, 225 bases, 211, 222, 228, 231 boric acid in, 232 canned, 221 canning of, 221 colors in, 238 composition of, 221 cookfng, effect of, 220 corning of, 219 curing of, 219 extracts, 240 acidity of, 253 albumoses in, 250 ash in, 249 composition of, 242, 243, 247 creatinin, 244, 252 creatinin in, 244, 252 fat in, 249 fluid, 241, 243, 244 gelatin in, 253 glycerol in, 254 meat bases in, 252 methods of analysis, 246 nitrogen compounds of, 249, 250 peptones in, 251 preservatives in, 254 proteoses in, 250 solid, 241, 242, 244 standards, 241 xanthin bases in, 253 fat, acidity of, 226 composition of, 226 determination, 226 gelatin determination, 231 glycogen in. 236 inspection, 217 law, 969 juices, 241, 245, 247, 248 manufactured, 218 methods of analysis, 225 mince, 927 nitrates in, 232 Meat, nitrogen determination, 226 nitrogenous bodies, separation of, 228 peptones in, 251 pickled, 218 powders, 247, 248 preservation of, 218 preservatives in, 232 proteins, coagulable, 231 proteoses in, 231 ptomaines in, 218 refrigeration of, 219 salicylic acid in, 233 salted, 219 smoked, 219 standards of, 218 sulphurous acid in, 231 unwholesome, 218 water in, 225 Melting point, 480 Mercury compounds in colors, 785 Metallic salts in canned goods, toxic effects of, 911 determination, 914 Metanil yellow, 810, 816 Metaproteins, 44 Methyl alcohol, detection of, 749, 878 Methylene blue, 802, 812 orange, 808 violet, 812 Micro-chemical reactions, 94 Micro-polariscope, 84 Microscope in food analysis, 81 references on, 98 reagents for, 90 stand, 82 Microscopical accessories, 84 analysis, 81 apparatus, 82 diagnosis, 86 reagents, 90 analytical, 91 clarifying, 92 Microscopy of agar agar, 943 allspice, 422 arowroot, 282 barley, 309 starch, 281 bean, 388 starch, 282 buckwheat, 311, 437 starch, 281 butter, 552 cassia, 426 cayenne, 441 cereal products, 305 charlock, 460 990 INDEX. Microscopy of chicory, 386 cinnamon, 426 cloves, 416 cocoa, 403 cocoanut shells, 419 coffee, 386 corn, 309 starch, 281 date stones, 390 fats, 510 flour, 306, 322 fruit tissues, 944 ginger, 449 honey, 633 jams. 944 jellies, 944 ketchup, 724, 725 lard, 557 mace, 466 milk, 124 mustard, 458 nutmeg, 464 oats, 309 oat starch, 282 oils, 510 oleomargarine, 552 olive stones, 436 paprika, 441 pea, 388 starch, 282 pepper, black, 433 long, 439 red, 441 white, 433 potato starch, 282 rice, 310 starch, 282 rye, 308 starch, 281 sago, 283 sawdust, 444 starches, 280 tapioca starch, 282 tea, 378 turmeric, 451 wheat, 306 starch, 281 Micro-technique, 82 Milk, 124 acidity of, 124, 153 adulteration of, 159 alkalinity of ash, 198 anilin orange in, 175, 177 annatto in, 175, 176 ash of, 127, 134 ashing of, 134 Milk, ass's, 127 boiled milk, detection, 155 boric acid in, 182 calcium oxide in, 189 calculation of proteins, 153 caramel in, 176, 177 carbonate in, 180, 182 chocolate, 397 citric acid in, 127 coloring matter in, 174-177 composition of, 124-126 constants, 169 ewe's, 127 fat of, 127, 134 fermentations of, 129 foods, prepared, 157 fore milk, 128 formaldehyde in, 178, 181 goat's, 127 human, 127 inspection, 159 known purity, 169 mare's, 127 methods of analysis, 130, 163, 168 microscopical appearance, 1 24 modified, 155 nitrogen compounds in, 125, 145 powder, 157 preservatives in, 177 proteins of, 125, 145, 153 records of analysis of, 172 references on, 208 ropy, 130 sampler, 131 serum, refraction of, 166, 167 specific gravity of, 166, 167 skimmed, 161 sour, analysis of, 186 souring of, 129 standards, 160 strippings, 128 sucrate of lime in, 196 detection, 197, 198 sugar, 125, 577 determination of, 593, 594, 598 determination of, in milk, 147^ 149, 151 systematic examination of, 130, 168 total solids in, 133, 134 calculation of, 151, 153, 154 watering of, 161 Milliau's cottonseed oil test, 518 Mil Ion's reaction, 41, 92 reagent, 92 Mill's bromine absorption method, 493 Mince meat, 927 INDEX. 991 Mince meat, adulteration of, 927 condensed, 928 standards, 927 Mineral colors, 792 content of food, 47 Mirbane, oil of, 886, 888 Mitchell and Smith fusel oil method, 748 Modified milk, 155 Mohler's test for benzoic acid, 835 Moisture, determination of, 61 Molasses, 567 adulteration of, 621 ashing of, 614, 624 clarifying, 614 composition of, 568 glucose in, 621 invert polarization at 87° C, 623 methods of analysis, 613 standard for, 621 sucrose in, 614 tin in, 625 total solids in, 613 vinegar, 763 MoUusks, 256 Mucoid protein, 127 Munson method for metallic salts, 914 Munson and Walker sugar method, 151, 598 table, 599 Muscle albumin, 211 fibers in meat, 211 sugar, 212, 238 Muscovado, 567, 568 Mushroom ketchup, 919 Mustard, 453 adulteration of, 459 ash of, 457 black, 453 cake, 455 charlock in, 459, 460 coloring matter in, 460 composition of, 455, 456 Dakota, 459 flour, 454 methods of analysis, 457 microscopical structure of, 458 oil, fixed, 454, 525 volatile, 453, 457 pickles, 926 prepared, 460 adulteration of, 460 composition of, 460, 461 methods of analysis, 461 sinalbin in, 454 mustard oil, 453 sinapin sulphocyanate, 457 standard, 459 Mustard, starch in, 459 turmeric in, 460 volatile oil of, 453 wheat in, 459 white, 453 Mutton, composition of 215 cuts of, 215 tallow, 529 Myosin, 42 insoluble, 44 Naphthion red, 808 Naphthol green, 801, 812 orange, 794 yellow, 794, 801, 808 S., 794, 808, 816, 817 Natural wine, 685 Neufchatel cheese, 202 New coccin, 816 green, 812 Nickel salts, 911 determination of, 918 Niebel's glycogen method, 236 Nigrosin, 802 Nile blue, 802 Nitrates in food, 40, 46 in watered milk, 168 Nitrobenzol, 886, 888 Nitrogen apparatus, 72, 73 compounds in milk, 145 determination of, 69, 73 free extract, 54 Nitrogenous bodies, 40 classification of, 40 separation of, in cheese, 205 in meat, 228 in milk, 125, 126,145 Noodles, 347 Notification, 10 Noyau, 754 Nuclein, 43 Nucleoproteins, 43 Nutmeg, 462, 463 adulteration of, 464 composition of, 462, 463 extract, standards, 881 Macassar, 465 microscopical structure of, 464 oil of, 463 standard, 892 standard, 464 Nutrose, 158 Nuts, composition of, 275 Oats, 271 analysis of, 271, 272 992 INDEX. Oats, ash of, 30? microscopic structure, 309 starch in, 282 Oil cakes, effects on butter of feeding, 531 larci of feeding, 560 anise, 892 basil, 893 bitter almond, 884, 885, 886 calorimeter, 495 cassia, 425, 892 celery seed, 892 cinnamon, 892 cloves, 892 cocoanut, 528 corn, 521 cottonseed, 516 ginger, 446 lard, 555 lemon, 870, 871, 880 terpeneless, 871 lemongrass, 872, 880, 88 1 majoram, 893 mustard, fixed, 454, 525 volatile, 453, 457 nutmeg, 892 oleo, 541 olive, 511 orange, 884 peanut, 522 peppermint, 890 poppyseed, 526 rape, 520 rose, 895 rosin, 527 savory, 892 sesame, 519 spearmint, 891 staranise, 893 sunflower, 526 thyme, 893 wintergreen, 889 Oils, edible, 471. See also Fats, acetyl value, 497 bromine absorption of, 492 bromination test, 494 cholesterol in, 502, 503, 507 composition of, 471, 472 constants of, 508, 509 elaidin test, 499 fatty acids in, 484, 499 iodine absorption of, 487, 492 judgment as to purity of, 473 Maumene test, 494 melting point, 480 methods of analysis, 473 microscopical examination, 510 Oils, edible, phytosterol in, 502, 503, 507 Polenske number of, 483 rancidity of, 473, 530 references on, 561 refractive index of, 477 Reichert-Meissl number, 481 saponification of, 472, 484, 486 sitosterol in, 522 specific gravity of, 474 factors, 475 thermal tests, 493 titer test, 500 unsaponifiable matter in, 501 Valenta test, 499 viscosity of, 477 Oleomargarine, 541 adulteration of, 543 coloring of, 542 constants of, 544 distinction from butter, 544, 546 healthfulness of, 543 manufacture of, 541 microscopical examination, 552 odor and taste, 545 palm oil in, 542 Zega's test for, 553 Oleo oil, 541 Olive, composition, 511 oil, 512 adulteration of, 512, 515 examination of, 515 refraction of, 514 standard, 513 Olives, pickled, 920, 926 Olive stones, 436 Orange colors, 787,794, 808,810, 815,816,817 extract, 884 oil, 884 soda, 054 standards, 884 terpeneless, 884 Orchil, 791, 808 substitute, 808 O'SulHvan-Defren sugar method, 150 Ovalbumin, 262 Oven, drying, 22 McGill's, 586 Ovomucin, 262 Ovomucoid, 263 Oxygen absorbed, 415 equivalent, 415 Oxyhaemoglobin, 43 Oysters, 257 Palas rapeseed oil test, 521 Paprika, 439 INDEX. 993 Paprika, added oil in, 445 adulteration of, 444, 445 composition of. 442 methods of analysis, 445 microscopical structure of, 441 ParafHn in beeswax, 643 in confectionery, 647 in fats, 510 in oleomargarine, 543 Paranuclein, 206 Parenchyma, 87 Pastes, adulteration of, 349 artificial colors in, 349 edible. 347 Italian, 347 lecithin phosphoric acid in, 349 methods of analysis, 349 noodles, 347 Patrick's method for water in butter, 531 test for thickeners in ice cream, 200 Paul method for foreign fats, 191 Pea, composition, 272 proteins of, 300 starch of, 282 Peanut oil, 522 adulteration of, 523 standards for, 522 tests for, 523, 525 Pear cider, 683 essence, imitation, 896- 897 Pectose- 93, 276 Pekar's color test of flour, 317 Pentosans, 285, 296 determination of, 285, 296 in cocoa products, 396 table for, 288 Pentose, 285, 296 Pepper, 428 adulteration of, 435 black, 429 buckwheat in, 437 composition of, 430, 432 dust, 436 ether extract in, 410 long, 438 microscopical structure of, 433 nitrogen in, 432 in ether extract, 433 olive stones in, 436 piperin in, 429 determination of, 433 red, see Cayenne and Paprika. shells, 435 standard, 435 varieties of, 429 white, 429 Peppermint extract, 890 composition of, 891 standards, 891 oil, 891 Peptides. 45 Peptones, 44 in cheese, 202 in meat, 211, 231 in milk. 146 Peter's test for benzoic acid, 835 Perrj', 683 Persian berries, 790, 810 Petroleum ether, 66 Phloroglucide, 286 Phloroglucinoi, 287 Phloxin, 806 Phosphate baking powders, 333 Phosphin, 803 Phosphoproteins, 43 Phosphoric acid in baking chemicals, 346 in beer, 725 Phosphotungstic acid reaction, 45 Photomicrography, 93 camera for, 96 Phytolacca, 790 Phytosterol, 502 acetate test, 507 crystallization of, 503 determination of, 503 distinction from cholesterol, 503 separation of, 503 Piccalilli, 926 Pickled meats, 218 Pickles, 925 adulteration of, 926 Pickling pump, 219 Picric acid, 350, 808 Pie filling. 928 Pimiento, 439, 442 Pineapple essence, imitation, 896, 897 Pioscope, 164 Piperin, 429 determination of, 433 Piutti ani Bentivoglio's method for colors in pastes, 351 Plant crystals, 90 Plasmon, 158 Plastering, of wine, 629 Platinum dishes, 61, 133, 134, 170 counterweights for, 170 Poisoned foods, 74 Poivrette, 436 Polariscope, 578. See also Saccharimeter. micro, 84 Polariscope tube jacketed, 639 short, for oils, 880 994 INDEX. Polarization at high temperature, 639 of essential oils, 880 honey, 639 jams and jellies, 938 lemon extract, 873 molasses, 614 orange extract, 884 sugar, 578 vinegar, 769 wine. 694, 703 Polenske number, 483 Ponceau, 794, 806, 810, 815, 816, 817 Poppyseed, 526 oil, 526 Pork, composition of, 216 cuts of, 216 Porter, 709, 712. See also Beer. Port wine, 689 Potash determination, 304, 345 Potassium myronate, 453, 457 Potatoes, composition of, 273 proteins of, 301 starch of, 282 Poultry, composition of, 216 Pratt citric acid method, 951 Preparation of sample, 55 Preservatives, 821 commercial food, 823 in butter, 538 in canned goods, 912 in carbonated beverages, 955 in fish, 257 in fruit juices, 947 in jams and jellies, 942 in ketchup; 921 in meats, 220, 232 in milk, 177, 183 in preserves, 928 of eggs, 266, 268 references on, 846 regulation of, 822 Preserves, 927 Pressure pump, 20 Price color method, 814 Primulin, 803 orange, 810 Process butter, 540 Prolamins, 42 Proof spirit, 677 Prosecution, 10 Protamins, 43 Proteans, 44 Protein grains, 90 Proteins, 40 coagulated, 44 conjugated, 43 Proteins, derived, 44 factor for. 40 of barley, 277, 300 of beer, 725 of cereals, 296 of condensed milk, 190 of eggs, 262 of milk, 125 calculation of, 153 determination of, 145 of peas, 300 of potatoes, 301 of rye, 277, 300 of wheat, 277, 298 secondary derivatives, 44 simple, 41 tests for, 41 Proteolytic fermentation, 158, 202 Proteoses, 44, 297 Proto-albumose, 44, 45 Proximate analysis, extent of, 53 expression of results of. 53 Prussian blue, 792, 812 in tea, 375 Ptomaines, 218 Publication of adulterated foods, 10 Pulfrich refractometer, 100 Pycnometer, 57 Pyroligneous acidj 764 in meats, 219 Pyronin, 803 Py rosin, 794 Quassiin, 727 Quercetin, 804 Quercitannic acid, 415 Quercitron bark, 790, 810 Quevenne's lactometer, 132 Quince essence, imitation, 896, 897 Quinolin yellow, 803 Quotient of purity of sugar, 586 RafBnose, 279, 577 determination of, 620 Rancidity, 473, 530 Rape oil, 520 test for, 521 seed, 520 Raphides, 90 Raspberry (color), 790 soda, 954 Reagents, 35, 90 references on, 38 table of, 26-34 Red colors, 785, 786, 790, 794, 806 INDEX. 995 Red ochre in sausages, 238 Red pepper, see Cayenne and Paprika. Red wines, 684, 689 Red wood, 444 References on beer, 756 butter, 562 canned goods, 961 cereals, 361 cocoa, 406 coffee, 406 colors, 819 dietetics, 49 distilled liquors, 758 eggs, 270 flavoring extracts, 898 flesh foods, 258 food economy, 49 inspection, 11 fruit products, 961 fruits, 361 general analytical methods, 79 laboratory equipment, 38 leavening materials, 364 liquors, 756 microscope, 98 mi'k, 208 oils, 561 preservatives, 846 reagents, 38 refractometer, 122 spices, 468 sugars, 650 sweeteners, 855 tea, 406 vegetable products, 961 vinegar, 780 wine, 757 Refractometer, 100 Abbe, 100 Amagat and Jean, 100 butyro, 100, loi heater for, 102 immersion, iii in oil analysis, 477 Pulfrich, 100 sliding scale for, 107 tables for, 104, 105, 113, 116, 120, 121 Wollny, 100, 139 Reichert-Meissl method, 481 Reichert number of butter, 549 Reinsch's test for arsenic, 728 Relishes, 920, 926 Renard's test for peanut oil, 523 for rosin oil, 527 Renovated butter, 540 Renovated butter, distinction from' butter and oleomargarine, 546 Resins, 89 Resorcin brown, 816 green, 812 yellow, 816 Respiration calorimeter, 2 Rhodamin, 803 Rice, composition of, 272 microscopical structure of, 310 polished, 272 starch, 282 Riche and Bardy methyl alcohol method 751 Richmond's cane sugar method, 185 sliding milk scale, 153 Ritsert's tests for acetanilide, 869 Ritthausen's method for milk proteins, 145 Roese-Gottlieb fat method, 190, 199 Roeser's mustard oil method, 457 Rohrig tube, 199 Root beer, 954 Ropy milk, 130 Roquefort cheese, 202 Rose, attar of, 895 Bengal, 806 extract, 895 standards, 895 rose oil in, 895 Rosin oil, 527 Rota's color scheme, 799 Rubner's fuel value factors, 48 Riihle-Brummer saponin method, 956 Rum, 742 composition of, 742 essence, 743 methods of analysis, 745 new, 743 standards, 742 Rj^e, composition of, 271 microscopical structure of, 308 proteins of, 300 starch, 281 Saccharimeter, 578 double wedge, 581 forms of, 583 normal weights for, 583 scales compared, 583 single wedge, 579 Soleil-Ventzke, 578 triple field, 581 Saccharimetry, 578 Saccharin, 850 detection of, 851 determination of, 852 Saccharine products, 565 996 INDEX. Saccharoses, 565 Safflower, 791, 808 Saffron, 791 Safranin, 802, 806 Sago, 283 Saleratus, 332 Salicylic acid, 831 detection of, 831 determination of, 832 in meat, 233 in milk, 180 Salmin, 43 Salted meats, 218 Sample, preparation, 55 Sanatogen, 158 Sanger arsenic method, 75 Black-Gutzeit method, 76 Sanose, 158 Saponification, 472, 484, 486 Saponin, 955 detection, 956 tests for, 957 Sarcolemma, 211 Sarsaparilla, 954 Sausages, 223 ash of, 225 color of, 224 composition of, 223 fat in, 226 glycogen in, 234 horseflesh in, 234 methcdi of analysis, 225 starch in, 223 water in, 225 Sauterne wine, 685, 688 Savory extract, standards, 892 oil, standards, 892 Sawdust, 450 Scarlet 6R, 816 Schiedam schnapps, 744 Schenk beer, 708 Schlegel's method for colors in pastes, 3^0 Schreiner's colorimeter, 77 Schultze's reagent, 93 Sclerenchyma, 87 Scovell sampling tube, 131 Sealed samples, 6, 159 Semolina, 347 Separatory funnel support, 68 Sericin, 42 Sesame oil, 518 adulteration of, 519 tests for, 519 seeds, 518 Shannon formic acid method, 842 Sherry wine, 687 Short's method for fat in cheese, 205 Shredded wheat, 352 Sieve tubes, 89 Silent spirit, 731 Sinabaldi's asaprol method, 846 Sinalbin, 545 mustard oil, 454 Sinigrin, 453 Sinks, 17 Sitosterol, 522 Smith and Bartlett tin method, 916 Smoked meats, 218 " Soaked " goods, 912 Soap-bark, 955 Soda, cherry, 954 determination of, 304, 345 lemon, 954 orange, 954 raspberry, 954 strawberry, 954 vanilla, 954 water, 952 syrups, 953 Sodium benzoate, 833 bicarbonate, 332 bisulphite, 839 carbonate, in milk, 180, 182 hydroxide, tenth-normal solution, 35 salicylate, 831 Soja bean meal, 357 Soleil-Ventzke saccharimeter, 578 Solid yellow, 801 Sorghum, 573 Sostegni and Carpentieri's test, 796 Souring of milk, 129 Sour milk, 139 Soxhlet, extractor, 64 Soxhlet's milk sugar method, 150, 152 Spaghetti, 347. See also Pastes. Sparkling wine, 685, 691 Spearmint, extract, 891 standards, 891 oil, 891 Specific gravity bottle, 57 of beeswax, 643 of liquids, 55 of liquors, 657 of milk, 131 of milk serum,. 166 temperature correc- tion for, 133 of oils, 474 of vinegar, 764 rotary power, 584 Spent tea leaves, 375 Spices, 408 INDEX. 997 Spices, adulterants of, 413 alcohol extract of, 410 ash of, 409 crude fiber of, 411 ether extract of, 410 lime in, 410 methods of analysis, 408 microscopical examination of, 412 nitrogen in, 410 references on, 468 starch in, 411 volatile oil of, 411 Spiral ducts, 89 Spirits, cologne, 731 distilled, 730 neutral, 731 silent, 731 standards, 730 velvet, 731 Spirit vinegar, 760, 763 Spoon test for butter, 549 Sprengel tube, 60 Stahlschmidt's caffeine method, 374 Standards for allspice, 424 anise extract, 892 oil, 982 beer, 711 brandy, 740 butter, 535 cassia, 428 extract, 892 oil, 892 cayenne, 443 celery seed extract, 892 oil, 892 cheese, 203 cinnamon, 428 extract, 892 oil, 892 clove extract, 892 oil, 892 cloves, 418 cocoa, 402 cream, 195 foods, 4 fruit butter, 927 ginger, 450 extract, 892 ice cream, 198 ketchups, 919 lard, 556 lemon extract, 870 oil, 871 mace, 460 maple products, 572 meats, 218 Standards for meat extracts, 241 milk, 160, 162 mince meat, 927 molasses, 621 mustard, 459 nutmeg, 464 extract, 892 oil, 892 olive oil, 513 pepper, 435 renovated butter, 541 rum, 742 savory extract, 892 oil, 892 staranise extract, 893 oil, 893 starch sugar, 574 sugars, 566, 574, 772 sweet basil extract, 893 _ oil, 893 marjoram extract, 893 oil, 893 thyme extract, 893 oil, 893 vanilla extract, 862 vinegar, 772 wine, 689 whiskey, 733 Standard solutions, equivalents of, 36 refractometric readings of, 120 Staranise extract, standards, 893 oil, standards, 893 Starch, 47, 89, 279 arrowroot, 282 barley, 281 bean, 282 buckwheat, 281 classification of, 280 corn, 281 detection of, 279, 943 determination of, 283 by acid conversion, 283 by diastase method, 283 in baking powder, 343 in cereals, 283, 296 in jams and jellies, 943 in milk, 185 in sausages, 233 in spices, 411 oat, 282 pea, 282 potato, 282 rice, 282 rye, 281 sago, 283 998 INDEX. Starch, syrup, 575 tapioca, 282 under polarized light, 283 wheat, 281 Stearin, beef, 541 cottonseed, 517 lard, 555 Sterilized butter, 540 Still, alcohol, 659 fractionating, 67 nitrogen, 73 water, 22 wine, 685 Stilton cheese, 202 Stokes' milk centrifuge, 136 Stone's method of carbohydrate separation, 295 Storch's method for boiled milk, 155 mucoid protein, 127 Stout, 709, 712. See also Beer. Strawberry soda, 954 Strippings, 128 Stutzer's gelatin method, 231 Suberin, 89 Sucrate of hme, 195, 197 Sucrose, see Cane sugar. Suction pump, 19 Sudan i, 801 Suet, 529 Sugar, 561 beet, 569 brown, composition of ash, 567 cane, 566, 567 classification of, 565 composition of, 568 grape, see Dextrose. in fruits, 566 in jams, 938 maple, see Maple syrup. methods of analysis, 585 muscovado, 567 organic non-sugars in, 586 quotient of purity, 586 raw, 568, 569 references on, 650 refining, 570 standards, 566, 572, 574 ultramarine in, 570, 590 Sulphur, dete mination of, 305 Sulphuric acid in baking chemicals, 346 in vinegar, 767 Sulphuring, 839 of fruits, 94S Sulphurous acid, 839 detection of, 840 determination of, 840 Sulphurous acid, in meat, 220, 232 Sunflower oil, 526 seeds, 527 Sweet basil extract, standards, 893 oil, standards, 893 Sweeteners, artificial, 850 Sweet marjoram extract, standards, 893 oil, standards, 893 Sweet wine, 685, 690 Syrup, analysis of, 613 ashing of, 614 maple, see Maple syrup. mixing, 57b starch, 576 total solids in, 613 Syrups, fruit, 952 soda water, 953 Sy's lead method, 630 Table sauces, 919, 920 preservatives in, 921 Tallow, 529 Tannin in cloves, 415 in tea, 370 in wine, 704 Tapoica, 282 Tartaric acid in baking powder, 339, 340 in fruit products, 941, 949 Tartrate baking powders, 332 Tartrazin, 816 Tea, 36s adulteration of, 374 ash of, 368, 369 astringents in, 377 caffeine in, 372, 373 composition of, 366, 367 exhaustive leaves in, 375 extract of, 370 facing of, 374 foreign leaves in, 376 leaf, characetristics of, 376 methods pf analysis, 368 microscopical examinaticoi of, 378 references on, 406 spent leaves in, 375 stems in, 376 tablets, 377 tannin in, 370 theine in, 372, 373 Technique, 82 Teller's method of separating wheat pro- teins, 298 Theine, 372 Theobromine, 396, 400 Thompson's boric acid method, 829 Thyme extract, standards, 893 INDEX. 999 Thyme oil, standards, 893 Tin, action of fruits and vegetables on, 904, 90s, 906 determination of, 914, 916 salts in molasses, 625 Tintometer, Lovibond, 78 Titer test, 500 Tocher's sesame oil test, 519 Tomato ketchup, see Ketchup. Tonka bean, 860 tincture, 862 Trillat methyl alcohol test, 750 Trop^eolin, 794, 808, 810 Turrheric, 450, 790, 810 as an adulterant, 452 microscopical structure of, 451 tests for, 453, 791 Ultramarine blue, 793, 812 . in sugar, 570, 590 in tea, 375 Uno beer, 714 Unsaponifiable matter, 501 Vacuoles in yeast cells, 330 Vanilla bean, 857, 858 exhausted, 859 extract, 857 acetanilide in, 868 adulteration of, 862 alcohol in, 869 alkali in, 860 artificial, 863 caramel in, 869 color value of, 870 composition of, 859 coumarin in, 863, 865 glucose in, 869 glycerin in, 869 lead number of, 867 methods of analysis, 864 prune juice in, 863 resins in, 864 standards, 862 tannin in, 865 tonka in, 863 vanillin in, 863, 865, 870 soda, 954 Vanillin, 859 determination, 865 microscopical structure, 867 Van Slyke's protein formula, 153 method of nitrogen separation in cheese. 205, 206 in milk, 146 Vaporimeter, 675 Veal, composition of, 214 cuts of, 214 Vegetable colors, 789 Vegetable colors in sausages, 239 Vegetables, 273 ash of, 302 composition of, 273 methods of proximate analy- sis of, 276 references on, 361 Ventilation, 15 Vermicelli, 347. See also Pastes. Vessels, 89 Vesuvine, 809 Victoria yellow, 352, 801, 808, 810 Villi vecchia and Fabris' sesame oil test, 520 Vinegar, 759 acidity of, 765 acids of, 766 adulterated, 778 adulteration of, 772 alcohol in, 766 apple, 773 arsenic in, 780 artificial, 774 ash of, 761, 764, 775 solubility and alkalinity of, 764 beer, 762 caramel in, 779 cider, 760, 773 artificial, 774 composition of, 760 copper in, 780 distilled, 763, 773 extract of, 764 furfural in, 779 glucose, 763, 773 glycerine in, 770 grain, 773 Hortvet number of, 768 hydrochloric acid in, 767 lead in, 779 acetate, test for, 768, 779 number of, 768 malic acid in, 767 malt, 762, 773 manufacture of, 760 metallic impurities in, 779 methods of analysis, 764 mineral acids in, 766, 767 molasses, 763 nitrogen in, 765 pentosans in. 770 phosphoric acid in. 764 polarization of, 769, 776 reducing sugars in, 770 lOCO INDEX Vinegar, references on, 780 residue of, 774 specific gravity of, 764 spices in, 779 spirit, 773 standards, 772 sugar, 773 sugars in, 769, 776 sulphuric acid in, 767 tartrate in, 769 tests on, 779 varieties of, 759 volatile acids of, 766 wine, 761, 773 wood, 764, 779 zinc in, 779 Vinous fermentation, 654 Violamin, 803 Viscogen, 196 Viscosity of cream, 195 of oils, 477 Vitellin, 43 Waage's Bombay mace test, 468 Walnut ketchup, 919 Water- bath, 21 Water glass, 266 Waterhouse butter test, 550 Weiss beer, 709 Weld, 810 Werner-Schmidt method for fat in cheese, 205 in milk, 139 Westphal balance, 56 West's benzoic acid method, 838 Wheat, 271, 272 ash of, 302 composition of, 271, 272 microscopic structure of, 306 proteins of, 277, 298 shredded, 352 starch, 281 Whiskey, 731. See also Distilled liquors, adulteration of, 738 aging of, 732 American, 735 Bourbon, 732, 734, 736, 737 British, 735 composition of, 734 imitation, 738 Irish, 732, 734, 735 manufacture of, 731 methods of analysis, 745 rye, 732, 734, 737 Scotch, 732, 734, 735 Whiskey, standards, 733, 734 Wijs's iodine absorption method, 492 Wild's saccharimeter, 583 Wiley's bromine pipette, 495 Wiley and Ewell's double dilution sugar method, 149 Wine, 684 acidity of, 696 added alcohol in, 695 adulteration of, 691 ameliorated, 691 Burgundy, artificial, 692 California, 688 cane sugar in, 693 Cazeneuve's co'or method, 705 chaptalizing, 693 claret, 687 artificial, 692 classification of, 685 coloring matter in, 704, 705 composition of, 686 corrected, 691 cream of tartar in, 702 "dry," 690 Dupre's color method, 705 extract in, 696, 697 fortified, 685, 690 fruit other than grape, 695 glycerin in, 703 hocks, 689 Madeira, 685, 686 Malaga, artificial, 692 malic acid in, 702 manufacture of, 684 methods of analysis, 696 modified, 691 natural, 685 non-volatile acids in, 701 plastering, 692 polarization of, 703 port, 689 potassium sulphate in, 704 raisin, 691 red, 684, 689 reducing sugar in, 703 references on, 757 sherry, 687 artificial, 692 sparkling, 685, 691 standards, 689 still, 685 sweet, 690 tannin in, 704 tartaric acid in, 701 varieties of, 687 vinegar, 761, 773 INDEX. lOOI Wine, volatile acids in, 696 jJj, watering of, 694 white, 684, 689 yeast of, 684 Wintergreen extract, 889 adulteration of, 890 wintergreen oil in, 890 oil of, 889 Winton lead number, 628, 768 moisture apparatus, 62 WoUny milk fat refractometer, 100, 139 tables for using, 141 table for converting Wollny de- grees into «7>, 143 Woodman and Davis benzaldehyde n:cAod, 929 and Taylor's caffetannic acid method, 383 Wood vinegar, 764, 777 Wool, double dyeing method with, 796 dyeing of, 795 for color tests, 795 vegetable colors on, 797 Wormy fruit, 945 Xanthin, 46, 211 Xantho-proteic reaction, 41 Xylan, 285, 288, 296 Xylose, 285, 288, 296 Yeast, 327 adulteration of, 331 composition of, 329 compressed, 328 dry, 328 in cider, 678 in wine, 684 microscopical examination of, 329 starch in, 331 testing, 330 vacuoles in, 330 Yeast extracts, 246 -Yellow colors, 785, 787, 790, 794, 808 Zega's test for oleomargine, 553 Zein, 42, 300 Zinc salts, 909 determination of, 914 I PLATE I. CEREALS. Fig. 121. — Barley, Xiio. Transverse section, showing in order, pericarp, seed coats, aleurone layer, and starch cells. Fig. 122. — Barley, X55. Surface view of epidermis vnth hairs. i^- o ^-T •<./gtr^*lJ*. Fig. 123. — Barley, X125. Surface view of upper chaff layer. Fig. 124. — Barley Starch, X220. PLATE II. CEREALS. Fig 12^. — Buckwheat, X no. Transverse section through part of pericarp, seed coat, and part of endosperm. Fig. 126. — Buckwheat, Xno. Surface view of scutellum. Fig. 127. — Buckwheat, Xno. Surface secdon. .-Meurone or proteid layer. ■*■< 7 -^^ -■ Fig. 128. — Buckwlieai Starch, X220. Starch granules separated. PLATE III. CEREALS. Fig. 129. — Buckwheat Starch, Xiio. Starch grains in masses. Fig. 130.^ — Corn, Xiio. Transverse section through pericarp, seed coat, proteid layer, and part of endosperm, showing starch cells. Fig. 131. — Com, Xiio. Surface view showing two layers of the mesocaarp. Fig. 132.— Corn, Xno. Surface section. Proteid layer. CEREALS. Pi. ATE IV f-O 5^^^:^ e v:''^. ^'1i>S>v::-^ ^y>^ ^^^ f Fig. 143. — Rice Starch, X220. Fig. 144. — Kyo, X 18 Transverse section through the entire grain PLATE VII. CEREALS. Fig. 145. — Rye, Xiio. Fig. 146. — Rye, Xiio. Transverse section through pericarp, seed coat, Surface \aew of epidermis and underlpng layers, aleurone layer, and starch cells of endosperm. Fig. 147. — Rye, Xiio. Surface view of epidermis and of seed ooat. Fig. 148. — Rye Starch, X220. PLATE VIII. CEREALS. Fig. 149. — Wheal, Xiio. Fig. 150. — Wheat, Xno. Transverse section through pericarp, seed coat, Surface view of outer and inner epidermis Also proteid layer, and starch cells of endosperm. showing proteid layer. Fig. 151. — Wheat, Xno. Surface view of epidermis, with hairs. ;^^.^*? it" X :j Fig. 152. — Wheat biarch, >; 220. PLATE IX. LEGUMES. ■"r^.f. "V. ■^m Fig. 153. — Bean, Xno. Transverse section through starch cells. Fig. 154. — Bean Starch, X220 Fig. 155. — Bean, X no. Transverse section through hull, showing palisade cells of epidermis, and underlying hypoderma. Fig. j5(i. ^ m , >' no. Transverse section through hull and part of endo- sperm, showing some of the starch cells. PLATE X. LEGUMES. Fig. 157 — Lentil, Xiio. Surface view of epidermis. Fig. 158. — Pea, Xiio. Transverse section through hull and seed coal, showing outer palisade cells and underlying hypoderma. Fig. 159. — Pea. Xno. Surface section through base of palisade layer. Fig. 160. — Pea, Xiio. Powdered pea hulls. PLATE XI. LEGUMES. Fig. i6i. — Pea, Xiio. Surface view of palisade cells. Fig. 162.— Pea, Xno. Transverse section through starch cells Fig. ki:;. — I'ca, ,30. Transverse section through starch cells. Fig. 164. — Pea Starch, X220. PLATE Xll. MISCELLANEOUS STARCHES. Fig. 165. — Potato Starch, >;22o. Pig. 166.— Potato Starch, X220. With polarized light. ^a^sT^'-JT^ V^i^^^ Fig. iby. — Arrowroot Starch, X220. Fig. 168. — Tapioca Starch, X220. (Cassava.) TURMERIC. SAGO. PLATE XIII. Fig. 169. — Turmeric, X 7°- Transverse section through rhizome Fig. 170. — Turmeric, Xiio. Longitudinal section. Note spiral ducts through the center. Vr- '--S?'^ J ■\s^. \-* V Fig. 171. — Powdered Turmeric, Xiio. Showing starch grains, fragments of cell tissue, coloring matter, etc. Fig. 172. — Sago Starch, X 220. PLATE XIV, COFFEE. Fig. 173. — Raw Coffee, Xiio. Fig. 174. — Roasted Coffee, X130. Transverse section of outer portion of endosperm. Transverse section through parenchvma of endo- sperm. Fig. 17^. — Coffee, Xno. Surface view of seed coat. Fig. 170. — Coffee, Xiic. Roasted, ground coffee, showing fragments of endosperm parenchyma and of seed coat. PLATE XV. COFFEE. CHICORY. v<^ ^ • )^ 'S' n\^.My^^^_ '^^ Fig. 177. — Adulterated Coffee, X130. Fig. 17S. — Adulterated Coffee, X 130. Dark masses of roasted pea starch are shown, The vascular ducts of chicor}' show most con- with transparent fragments of the palisade spicuously in this field, cells of the pea-hull. Fig. 179. — Chicory, X25. Transverse section through the root. Fig. 180. — Chicory, Xiio. Transverse section. PLATE XVI. CHICORY. COCOA. Fig. i8i. — Chicon-, Xiio. Tangential section, showing reticulated ducts and wood parenchyma. Fig. 1S2. — Chicory, Xiio Radial section, showing bark parenchyma and milk ducts. JP? JR.^ '^'* -%0 Fig. 183. — Chicor}-, Xiio. Roasted and ground, showing fragments of ducts and other tissues. Fig. 184. — Cocoa, Xno. Transverse section through periphery of seed, seed coats, and cotyledon. ILATE XVII. COCOA Fig. 185. — Powdered Cocoa, Xiio. Fig. 186. — Adulterated Cocoa, X no Showing admixture of arrowroot with the cocoa powder. Fig 187. — Cocoa Shell, Xno. Transverse section through epidermis, pulp, and mucilaginous layers of the pericarp and seed coat. Fig. 188.— Cocoa Shell, Xnc. Longitudinal section through shell PLATE XVIII. TEA. SPICES. Fig. 189. — Tea, X55- Transverse section through midrib of leaf. Xote the paHsade layer below the upper epidermis, the inner wood vessels above the center, and the parenchyma of the pulp. Fig. 190. — Tea, Xiio. Surface view of lower epidermis, with stomata and one of the hairs. , ,. .i'.-''*'iSisl57's.l-?a»ax^. Fig. 191. — Allspice, X9. Transverse section through the entire berry, show- ing the two cells, with kidney shaped seed in each. Fig. 192. — Allspice. X70. Transverse section through pericarp, showing oil spaces and stone cells. PLATE XIX. SPICES. %'^ ^^' Fig. 193. — Allspice Seed Xiio. FiG. 194. — Allspice Seed, Xiio. Transverse section through seed shell and part of Transverse section through the resinous portion of embr\'o, showing starch cells. the seed coat, showing port wine colored lumps of gum or resin. Fig. 195. — Powdered Allspice, Xno. Fig. 196. — Adulterated Allspice, X no. Showing stone cells, resinous lumps, and starch. Showing a large fragment of the seed skin of cayenne at the left. SPICES. PLATE XX. Fig. 197. — Cassia Uark, X45- Transverse section through the bark. Fig. 198. — Cassia Bark, X45. Longitudinal section. Fig. 199. — Cassia Bark, Xiio. Transverse section, showing cork cells, parenchy- ma, and stone cells. Fig. 200. — Cassia Bark, Xiio. Longitudinal section, showing bunches of bast fibers at the left, starch cells in the center, and stone cells at the right. PLATE XXL SPICES. Fig. 201. — Ceylon i i.uia:;...:; Lark, Xiio. Fig. 202. — Ceylon Cinnamon Bark, Xiio. Transverse section, showing many bast fibers and Longitudinal section, showing bast fibers, stone starch cells. cells, and parenchyma. Fig. 203. — Powdered Cassia, Xno. Showing stone cells, starch, and corky tissue. Fig. 204. — Powdered Cassia, Xiio. Showing bast fibers and starch. PLATE XXII. SPICES. <4iL«k Fig. 205. — Powdered Cassia, X no. Showing large bast fiber and starch grains. Fig. 206. — Adulterated Cassia, Xiio. A mass of foreign bark. Fig. j 7 ' '. ' , ' no. Transverse section through pericarp. Fig. 208. — Cayenne, Xno. Transverse section through seed coat and part of endosperm. Collapsed parenchyma cells sepa- rate endosperm from long epidermal cells. SPICES. PLATE XXIII. Fig. 209. — Cayenne, Xiio. Surface view of fruit epidermis. Fig. 210. — Cayenne, Xno. Surface view of two lavers of seed coat. Fig 211 . — Powdered Cayenne, X 1 10. . A large mass of fruit epidermis. Fig. 212. — Powdered Cayenne, Xno. Showing chiefly two of the seed coat lavers. PLATE XXIV. SPICES, Fig. 213. — Adulterated Cayenne, X130. Corn and wheat starch and cocoanut shells appear chiefly. A bit of cayenne is shown at the right. Fig. 214. — Adulterated Cayenne, X214. The central mass is ground red wood, surrounded by corn starch grains. Fig. 215. — Clove, X65. Transverse section from the center outward to epidermis, showing parenchyma. Fig. 216. — Clove, Xiio. Transverse section near epidermis, showing large oil cavities. PLATE XXV. SPICES. ;^- .\ Pig. 217. — Clove, X28. Longitudinal section through entire clove. Fig 21S— Clove, X70. Central longitudinal section, showing duct bundles. FiG 219. — Clove, X 110. Surface view of epidermis Fig. 220. — Powdered Cloves, Xi.^o. Dense, spongy tissue, with small oil drops. SPICES. PLATE XXVI. Fig. 221. — Clove Stem, Xyc. Transverse section through outer part of stem, showing bast fibers at the left, parenchyma in the center, and stone cells near the epidermis. Fig. 222. — Clove Stem, X25. Centriil longitudinal section through entire stem, showing bast fibers in the center, and stone cells at the right. Fig. 223. — Clove Stem, X70. Longitudinal section, showing the stone cells. Fig. 224. — Powdered Clove Stems, Xiio. Showing fragments of tissues, .<;tone cells, and bast fibers. SPICES. PLATE XXVII. ^^■■'^ Fig. 225. — Powdered Clove Stems, Xiio. Showing bundle of bast fibers. Fic. 226.— Adulterated Cloves, X130. Showing chiefly stone cells of cocoanut shells. Fig. 227. — Adulterated Cloves, X130. With large admixture of cocoanut shells. < .ML-'' ^' ^^-/' • ^ ' <^■l•r■l:'-. ;■■■ ,\\\ •• Fig. 228. — Ginger, X no. Transverse section, showing starch cells with • contents. SPICES. PLATE XXVllI. Fig. 229. — Ginger, X no. Fig. 230. — Ginger, X no. Transverse section, showing parenchyma, starch Longitudinal section, showing spiral ducts and grains, and duct vessels. pigment cells. t-'-A -'■•.0 -^ Fig. 231. — Ginger Starch, X220. Fig. 232. — Adulterated Ginger, X 130. A mass of wheat bran tissue is most conspicuous. SPICES. PLATE XXIX. Fig. 233. — Adulterated Ginger, X130. '^ Fig. 234. — Adulterated Ginger, X130. The central dark mass is a yellow fragment of Containing a large admixture of corn and wheat turmeric. starches Fig. 235. — Penang Mace, Xno. FiG. 236. — Bombay or Wild Mace, Xrio Transverse section through epidermis and oil cells, Transverse section through outfr lavers, showin : showing also parenchyma with contents of yellow and red resinous lumps amylodextrin. PLATE XXX. SPICES. Fig. 237. — Nutmeg, Xiio. Transverse section through the exterior and in- terior teguments of the seed and part of the endosperm, showing starch cells. Fig. 238. — Nutmeg, X25. Transverse section near exterior of seed. Fig 239. — Nutmeg, Xiio. Surface view of seed coat, showing also portions ol underlying tissues. Fig. 240. — -Powdered Nutmeg, Xiio. PLATE XXXI. SPICES.. Fig. 241. — White Mustard, Xiio Transverse section through mucilaginous epider- mis, sub-epidermal parenchyma layer (square cells\ palisade cells, and broken parenchyma laver of the hull. Fig. 242. — White Mustard, Xiio. Transverse section through the tissue of radicle. the Fig. 243. — White Alustani Xiio Surface view of two layers of the hull or seed coat- Fig. 244. — While Mu-lani, Xiic. Surface section through palisade cells and under- lying layer of the seed coat. PLATE XXXII. SPICES. Fig. 245. — Black Mustard, Xiio. Transverse section, showing fragments of the epi- dermis and dark colored palisade cells of the seed coat. Fig. 246. — Black Mustard, Xno. - Surface view of two of the seed coat lavers. i^-9 Fig. 247. — Ground Alustard, X130. Ground, without removal of the oil. Fig. 248. — Ground Mustard Hulls, Xno. PLATE XXXIII. SPICES. Fig. 249. — Dakota Mustard Flour, Xiio. Fig. 250. — Adulterated Mustard Flour, X130. Dark spots show starch grains of foreign weed Showing masses of wheat starch, seed, stained with iodine. Fig. 251. — Pepper, Xno. Transverse section through inner part of pericarp (including parenchyma and seed coat layers) and portion of perisperm, showing starch and oil cells. Fig. 252. — Pepper, Xiio. Surface view of hypodermal layer. SPICES. PLATE XXXIV. Fk".. 253. — Pepper, Xiio. Transverse section through outer part of pericarp, showing epidermis, underlying stone cell layers, parenchyma, and seed coat. Fig. 254. — Pepper, Xiio. Surface section through stone cell layer. x: '- '^ f^A-^'-i'-^ Jit Fig. 255. — Pepper Starch, X220. Starch granules separated. Fig. 256. — Pepper Starch, Xiio. Starch grains in masses. 1 i SPICES. PLATE XXXV. jtm^ Fig. 257. — Ground Pepper Shells, Xno. Mainly sho^^^ng stone cells. Fig. 258. — Adulterated Pepper, X 130. Showing wheat and buckwheat starches. •j^ft'i, '0^'5k.^ "X. 9' XK' >o'. .$."1 X^f : -"^ Fig. 259. — AdulKiau-d Pepper, X 130. Showing wheat, corn, and rice starches. Fig. 260. — Adulterated Pepper, X130. The large, lower mass shows buckwheat starch, while the finer-grained mass near the top is of pepper. PLATE XXX\'I. SPICES. SPICE ADULTERANTS. ■,,v; ,.> Fig. 261. — Adulu-ralcd Pcppur, Xiio. Fig. 262. — Adulterated Pepper, X130. The central mass shows the sclerenchyma cells of Cayenne and wheat starch are the adulterants, olive stones. ,,