3d E&2 I C.2 ' J "» OF CAUFOttflA LIBRARY DAVIS COPY ■ Division of Agricultural Sciences _ «• UNIVERSITY OF CALIFORNI CHEMICALS AND THE FOOD INDUSTRY DONALD G. CROSBY CALIFORNIA AGRICULTURAL Experiment Station Extension Service MANUAL 26 r LIBRARY imiVERSITY OF CALIFORNIA DAVIS JUNE 1960 t \ \ CHEMICALS AND THE FOOD INDUSTRY ROBERT M. IKEDA* Department of Food Science and Technology, University of California, Davis. DONALD G. CROSBY Research Department, Union Carbide Chemicals Company, Division of Union Carbide Corporation, South Charleston, West Virginia. *Present address: Fruit and Vegetable Chemical Laboratory, U.S.D.A., Pasadena, California. UNIVERSITY OF CALIFORNIA DIVISION OF AGRICULTURAL SCIENCES Agricultural Experiment Station — Extension Service LIBRARY UNIVERSITY OF CALIFORNIA DAVIS \ FOREWORD There is a great deal of confusion and misinformation being disseminated about the use of chemicals by the food industry, not only among lay people but also even among food scientists and technologists. Many people believe that the use of chemicals in food is inherently harmful and must be avoided at all costs. They are either not aware or do not stop to realize that foods themselves are mixtures of chemicals. Many, perhaps most of the lay public, do not appreciate that modern chemistry is a most useful tool in the solution of food production, processing and marketing problems; in certain cases the use of a chemical may be the only sure and safe way to solve a food problem. Because of these facts the authors of this publication have sought to present the "facts of the case". The main objective is to discuss the legitimate use of chemicals in the processing, manufacture, storage, and distribution of food. Their use in producing foods has been left to others to discuss. In the main part of this manual the general nature of the U. S. food industry is treated. Key statistics relating to trends in production-consumption patterns are presented with indications for the future. Next some of the key technical problems of the industry are listed and discussed. Examples are provided to show how chemicals are being or might be used in the solution of these prob- lems. Another section of the manual deals with the current use of chemicals by the food industry. The data given were obtained both by a survey of the food and chemical literature as well as by means of direct contacts made by one of the authors. These are enlightening facts and show the great extent to which chemicals have been found useful in solving food processing and marketing problems. In a final section there is listed chemicals now permitted in foods by federal regulatory agencies: U. S. Food and Drug Administration, Agricultural Research Service (U. S. Department of Agriculture) and the Agricultural Marketing Service (U. S. Department of Agriculture). It should be noted that these lists are com- plete and accurate only as of the date the manual went to press. Applications for the use of new chemicals in food and reappraisal of the safety of already-approved chemicals are under continuous review by regulatory officials. Up-to-date information may best be secured by communicating directly with the federal agencies concerned. E. M. Mrak G. F. Stewart University of California, Davis \ CONTENTS Part I. Introduction 1 A. Food Consumption in the United States 1 B. Relationship of Chemicals to the Food Industry 9 C. Development of Chemicals for Food Use 12 Part II. Problems of the Food Industry 14 A. General Food Problems 14 B. Meat 16 C. Poultry 22 D. Fish and Fish Products 25 E. Dairy Products 30 F. Eggs 35 G. Fats and Oils 37 H. Fruits and Vegetables 43 I. Cereals and Cereal Products 52 J. Wine 65 K. Beer 70 L. Coffee and Tea 73 M. Cocoa and Chocolate 77 N. Sugar and Honey 82 O. Spices 84 P. Animal Feed 87 Pare III. Chemicals Used by the Food Industry 93 Preservatives 94 Nutritional Supplements 96 Coloring Agents 97 Flavoring Agents 99 Agents to Improve Functional Properties 103 Processing Aids 105 Moisture Content Controls 107 Controls for Acidity and Alkalinity 108 Controls for Physiological Activity 109 Other Agents 109 Official Lists of Approved Chemicals 110 PROBLEM or POSSIBLE IMPROVEMENT in the FOOD INDUSTRY Application of a chemical used in another food commodity Application of a chemical used outside the food industry Development of a new chemical Evaluation of the chemical to alleviate the problem or to improve product or processing procedure 1 i Toxicity studies with suggested tolerance Development of a suitable method of analysis Regulatory approval USE OF CHEMICALS IN FOODS OR FOOD PROCESSING r PART I— INTRODUCTION Food Consumption in The United States According to statistics compiled by the United States Department of Agriculture (1 ) , the American public spent some 67 billion dollars for food in 1957, out of a disposable personal income of more than 305 billion dollars. Clearly, a greater pro- portion of the average family's income goes for food than for any other single category on its budget, and there are strong indications that even this mark- edly large apportionment is consistently on the increase. Between 1950 and 1957, per capita food expenditures increased 24 per cent, while the retail food price index in- creased 24 per cent, while the retail food price index increased by only 12 per cent. Several factors can account for the in- creased food expenditures: The per cap- ita disposable income increased 39 per cent during this period, and with this in- crease came a shift in food habits from the consumption of low-cost commodi- ties, such as cereal products and pota- toes, to more expensive items, such as meat and poultry. Furthermore, there was a new willingness evinced to pay higher prices for store convenience, at- tractive packaging and display, quality, and service. The highly planned super- market was replacing the randomly or- ganized corner grocery. Table 1 shows the percentage of the food dollar that was spent on the various food commodities from 1947-49, the pe- riod commonly referred to in establish- ing agricultural indices. Such indices are readily available, and can be used to extend the information in Table 1 to any given year. It is indicative of the increased impor- tance placed on them in the diet that more than one-half of the food expendi- tures were made for meat, poultry, and the dairy products, and it is interesting to note that there was a pronounced rise in civilian buying of these foods even during wartime rationing (Figure 1). While the consumption of most vegeta- bles and fruits has remained remarkably constant for many years, there has been a dramatic increase in the use of citrus fruits and tomatoes. The consumption of fats and sugars also has been fairly con- stant, with the exception of the period of World War II rationing (Figures 2, 3). And Americans are now drinking more coffee, Tea, and cocoa than ever before (Figure 4). During the past few years, a large number of convenience items, such as precooked frozen foods, cake mixes, etc.. have appeared on the market. Although there are no statistical data on these items, it is reasonable to assume their widening popularity (2). (It is possible, incidentally, that the continued decline in overall use of potatoes may be retard- [i] Table 1. Food Expenditures in the United States (1947—49). Commodity Meat, Fish, and Poultry- Meat Beef Veal Lamb and mutton Pork (including bacon and salt side) .... Offals Total Meat Fish Fresh (edible weight) Canned Cured Total Fish Poultry Chicken (dressed weight) Turkey (dressed weight) Total Poultry Total Meat, Fish, and Poultry . Eggs Dairy Products Fluid Milk Fluid cream Cheese Condensed and evaporated milk Ice cream (actual weight) Buttermilk (natural and cultured) Fluid skim milk Milk in chocolate drinks Nonfat dry milk solids Cottage cheese Total Dairy Products, excluding butter Fats and Oils Butter Lard Margarine Shortening Other edible oils Total Fats and Oils, including butter Per capita consumption in 1947-49 Per cent of food dollar pounds per cent 51.0 9.8 8.8 1.6 4.2 .8 62.7 10.0 10.4 1.9 24.1 5.9 1.3 3.8 .9 0.6 .1 2.3 23.7 4.0 4.0 .9 4.9 31.3 46.7 6.3 299.0 8.7 9.6 1.2 6.9 1.3 19.8 .8 18.5 3.0 38.9 .7 12.8 .2 6.5 .2 3.1 .2 2.9 .2 16.5 2.5 1.0 .7 1.1 1.2 6.5 I 2 Table 1 — (Continued) Commodity Fruits Fresh Oranges and tangerines . Grapefruit Lemons and limes Apples Bananas Grapes Peaches Pears Cantaloupe Watermelons Other Home garden melons . . . Total Fresh Fruits . . Canned Apples and applesauce . . Apricots Peaches Pears Pineapples Salad and Cocktail Other Total Canned Canned Juices Grapefruit Orange Blend Other Total Canned Juices Frozen Fruits and Juices Concentrated juices Fruits Total Frozen Dried Fruits Prunes Raisins Other Total Dried Total Fruits Per capita consumption in 1947-49 pounds 1.8 1.0 4.5 1.3 2.8 2.1 4.6 3.3 4.3 2.1 6.3 .4 2.9 1.2 1.8 1.2 Per cent of food dollar per cent 35.3 1.0 11.6 .3 4.3 .2 27.7 1.0 18.9 .9 5.3 .2 11.1 .4 4.9 .2 6.5 .1 14.3 .1 6.2 .3 12.5 .2 4.9 .1 .1 .2 .1 .2 .1 .3 1.1 .1 .1 .1 .3 .6 .1 .3 .4 .1 .1 .1 .3 7.3 [3] Table 1 — (Continued) Commodity Vegetables Fresh Beans, snap Cabbage Carrots Celery Corn Lettuce Onions Spinach Tomatoes Other Home garden output Total Fresh Canned Beans, snap Beets Corn Peas Pickles, mixed Spinach Tomatoes, whole Tomato catsup and chili sauce Tomato paste, pulp, and puree Vegetable juices Other Total Canned Other Processed Products Canned baby foods Frozen vegetables Canned soups Total Other Processed Total Vegetables . . . Potatoes and Sweet Potatoes Potatoes Sweet potatoes Home garden output Total Per capita consumption in 1947-49 pounds 4.1 13.8 8.1 7.0 6.8 14.0 10.2 1.4 10.9 29.6 90.6 2.8 1.1 5.2 5.6 3.3 1.1 4.3 2.5 3.3 4.1 5.3 3.2 2.9 9.3 Per cent of food dollar per cent 0.3 .3 .3 .4 .1 .6 .3 .1 .4 1.5 3.7 8.0 .1 * .3 .2 .3 .1 .2 .2 .2 .1 .4 2.1 .3 .3 .7 1.3 11.4 1.7 .3 .1 2.1 * Less than 0.05 per cent. f 4. 1 Table 1 — (Continued) Commodity Per capita consumption in 1947-49 Per cent of food dollar Beans, Peas, and Nuts Dry edible beans pounds 6.6 .6 4.4 2.4 2.0 129.0 6.2 3.1 1.4 13.4 1.5 2.9 4.8 90.4 12.9 18.0 .6 4.0 per cent .6 Dry field peas * Peanuts .6 Tree nuts (including coconut) .8 Home garden dry beans and peas .2 Total 2.2 Cereal Products White and whole wheat flour 5.8 Semolina flour .4 Wheat cereal .2 Rye flour .1 Corn meal .3 Corn cereal .1 Oatmeal and other oat food products .1 Rice .3 Total 7.3 Sugars and Syrups Sugars (excluding duplication) f Syrups (excluding refiners' and honey) 5.7 .5 Total 6.2 Candy Beverages Coffee 2.4 Tea .3 Cocoa .2 Total 2.9 Soda Beer Wine Condiments Vinegar Mustard Salt Pepper All Foods in Index 100.0 * Less than 0.05 per cent. f Excludes sugar used in frozen and canned fruits and juices, canned vegetables, condensed milk, and ice cream. [5] 450 400 350 £ 300 Z 3 o Ol 250 200 150 100 DAIRY PRODUCTS EGGS (In Number) CEREAL PRODUCTS V\ MEAT, FISH, and POULTRY _/\ / _/ * V y\ \ 1925 1930 1935 1940 1945 1950 YEAR 1955 1957 Fig. 1 . Approximate per capita U.S. food consumption patterns, major food groups. ed somewhat by the recent introduction of packaged, processed products, such as frozen mashed potatoes.) More and more of the drudgery of food preparation is being borne by the food processor, thereby relieving the housewife of this burden and freeing her time for other activities. But with proc- essing ever more in the food picture, the problems of preparation, storage, and distribution are multiplied, and to meet this challenge, processors are inevitably employing scientific methods to make their products easier to use, tastier, less perishable, and more nutritious. Chemi- cals already have found their place in helping meet these needs, and their use is certain to increase. 161 to O z o 260 240 220 200 180 160 140 120 100 80 OTHER VEGETABLES and FRUITS POTATOES and SWEET POTATOES LEAFY GREEN and YELLOW VEGETABLES S*s 1925 1930 1935 1945 1950 1940 YEAR Fig. 2. Approximate per capita U.S. food consumption patterns, major food groups. 1955 1957 [7] CO Q Z o Q. 140 130 120 110 100 90 80 70 60 50 SUGAR and SYRUPS CITRUS FRUITS and TOMATOES • * V S\ FATS and OILS v- V\A 1925 1930 1935 1940 1945 YEAR 1950 1955 1957 Fig. 3. Approximate per capita U.S. food consumption patterns, major food groups. [8 | 1 ■ —T ■ — r 1 22 ■ " 20 DRY BEANS and PEAS, NUTS and -V 1 \ • • - 18 SOYA PRODUCTS • • • •Y- - • i • • • \ * • • • • A A to Q 16 --/ V V / • < \ I • • . \ # • • . \# • * • ^# « • # ~ » •» • * • 4 • • • ♦ • * • • • • • • • • ■ • • • • ■ • • * * • « • • • • • • • • i • * I / m * \ J S.J • • • • Z :d O a. v; 14 ->' • • . • . • . » • • • • • • • • •J • ■ 12 • • COFFEE, TEA, and COCOA - J g J^ J^ j^ 1925 1930 1935 1945 1950 1940 YEAR Fig. 4. Approximate per capita U.S. food consumption patterns, major food groups 1955 1957 Relationship of Chemicals to the Food Industry The definition of the term "food indus- try" is an arbitrary one, since the move- ment of food from the farm to the con- sumer's home involves so many different activities. For present purposes, we will assume that any operation which in- volves manufacture, treatment, process- ing, or storage of commercial food items, between harvest or slaughter, and whole- sale distribution, is carried out by a "food industry." In 1955, the 28 most important food manufacturers reported sales totaling $5,813,000,000, an increase of more than 83 per cent over their sales in 1945. In 1957, 1,688,228 workers were employed by about 40,000 separate food manufac- turers; Table 2 indicates the dispersal of these employees throughout the in- dustry. In 1947, the food industries were the nation's largest consumers of chemicals (including fats and oils), making pur- chases amounting to approximately 1.2 billion dollars, or 8.6 per cent of the total chemicals' sales. Table 3 shows the con- [9] Table 2. Workers Employed by Food Manufacturers (1957). Industry Meat Dairy Canned and frozen food Grain products Bakery products Sugar Candy, etc Beverages Miscellaneous food Total Number employed 313,106 296,751 213,319 107,375 303,746 28,300 79,985 202,363 143,283 1,688,228 tribution of each type of chemical to this total. Unfortunately, more recent informa- tion on such chemical consumption is in- complete. Government data presented here were not released until 1955, which indicates the difficulty with which reli- able statistics on the subject are accumu- lated. More extensive and timely data may be available in the future through a regular "census of manufacturers" (4). The uses to which these chemicals are currently being put by food manufac- turers may be considered in several cate- gories: 1 . Preservatives The three general types of preserva- tive problems for which chemicals are used are microbiological spoilage, chem- ical deterioration, and insect infestation. Common examples of compounds em- ployed for these purposes are salt to pre- serve fish, sulfur dioxide to maintain ac- ceptable color in dried fruit, and methyl bromide to prevent insect infestation of cereals and other foods. 2. Nutritional supplements The use of additives such as vitamins, minerals, and amino acids, has improved general nutrition in this country. An ex- ample is the supplementation of flour with Vitamin B 19 riboflavin, and iron. 3. Coloring agents Food color may be intensified, modi- fied or stabilized by the use of natural coloring materials, certified food dyes, or derived colors. Compounds are now Table 3. Purchases of Chemicals by Food and Kindred Inorganic chemicals Organic chemicals Plastics Synthetic rubber Synthetic fibers Explosives Drugs — medicines Soap, glycerol, etc Paint Gum and wood chemicals Fertilizers Vegetable oils Animal oils Miscellaneous Total Meat and poultry 1.3 0.2 0.0 0.0 17.7 0.0 0.2 0.0 1.0 0.0 0.0 19.9 50.0 16.5 106.8 Dairy products 1.7 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 17.8 20.3 Food preservation 1.0 7.3 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 54.5 0.0 3.5 66.8 Grain products 4.5 0.4 0.0 0.0 0.0 0.0 33.3 0.0 0.5 0.3 0.0 38.5 9.7 3.1 90.3 Bakery products 0.9 0.2 14.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 19.1 0.0 5.2 39.9 [101 added to butter for uniform color-main- tenance throughout the year, and the red color in cured meat products, such as ham and bacon, is due to the sodium nitrite used in the curing process. 4. Flavoring agents Both synthetic and natural flavors are extensively added to soft drinks, and so- dium glutamate is used to impart a meat flavor to canned vegetables and soup. 5. Agents to improve functional properties Additives used for this purpose act as thickening, firming, and maturing agents, or may affect the colloidal properties of foods, such as gelling, emulsifying, foam- ing, and suspension. Calcium salts firm the texture of whole canned tomatoes, and chlorine dioxide is used as a matur- ing agent in flour. 6. Processing aids These include sanitizing agents, chem- icals to remove extraneous or other ma- terials, metal binding compounds, anti- foam agents, and substances added to prevent fermentation. Detergents are Industries (1947) (4). Sugar Alcoholic beverages Miscel- laneous Total 2.5 0.5 12.8 25.2 0.0 16.5 14.6 39.5 0.0 0.0 10.4 24.9 0.0 0.0 2.2 2.2 0.0 1.5 0.7 19.9 0.0 0.0 0.0 0.0 0.0 0.0 5.5 39.0 0.0 4.5 3.4 7.9 0.0 0.0 0.5 3.0 0.0 0.0 0.5 0.8 0.0 0.0 0.0 0.0 0.0 0.0 718.7 850.7 0.0 0.0 18.4 78.1 1.8 0.2 53.2 101.3 4.3 23.2 840.9 1,192.5 Final evaluation of flavor depends on the educated palate of an expert. (Photo courtesy International Flavors & Fragrances, Inc.) used to facilitate the removal of dirt and insects; silicones act at antifoam agents in wine fermentation; and citric acid is used as a binding compound to reduce the action of metals in oxidative ran- cidity. 7. Moisture content controls Chemicals are employed to increase or decrease moisture levels in a variety of commodities; glycerine is used in marsh- mallows as a humectant to retain soft texture; and calcium silicate is added to table salt as an anticaking agent. 8. Controls of acidity and alkalinity Various acids, alkalies, and salts are added to food to obtain a desired pH; phosphoric acid is used in soft drinks; and salts, such as sodium citrate, are added to fruit jellies. 9. Controls for physiological activity The chemicals in this category are ap- plied to fresh produce, to act as ripening or antimetabolic agents; ethylene hastens ripening in bananas; and maleic hydra- zide prevents sprouting of potatoes. A list of chemicals and their uses for the purposes stated above, appears in Part III. [11] @ Development of Chemicals for Food Use The food industry needs the coopera- tion of the chemical industry in learning how best to approach the problem of using chemicals in its products and proc- esses, and how to decide which new com- pounds hold the greatest promise. A per- tinent statement was made in this respect by Sir Frank Engledow in his address to the British Food Manufacturing Indus- tries Association (5) . He said, "The food industry should beware of the danger of waiting for the 'creative' sciences to hand over their discoveries and developments. They will not and cannot go far out of their way for food manufacture unless we can tell them what we want and give them initial ideas for wholly new devel- opments." In developing chemicals to be applied to foods, a number of factors must be considered. Obviously, the chemicals must facilitate production or improve quality without concealing inferiority or minimizing the need for good manufac- turing practices. In the early days of modern food manufacture, the applica- tion of chemicals to food products and processes was so abused that manufac- turers and customers alike came to asso- ciate the term "chemical additive" with inferior or undesirable food quality. That some measure of this feeling about addi- tives persists is best evidenced by the fact that virtually no chemical additives are used directly in milk today, even where their use would frequently consti- tute an improvement. The nutritive value and organolep- tic properties of the food products must not be impaired by the additive. Often, in investigations of the development of food additives, the full effect of the addi- tive is ignored. Its effect on texture, fla- vor, and color must be considered not only in the application, but also after storage and shipment through regular marketing channels. It is a basic fact of food marketing that physically unaccept- able products will not sell. The safety of the additive and of its decomposition under conditions of com- mon usage, must be established beyond any doubt (6, 7, 8). Regulatory author- ity has been retained by the Federal Gov- ernment (U. S. Food and Drug Admin- istration), state boards, and various agencies of local government. Such con- trol is of universal benefit, and several groups, notably the Food Protection Committee of the National Research Council, are engaged in establishing sound scientific bases on which to give approval to additive substances. In recent years, the public and its rep- resentatives have shown increasing "in- terest" in health problems arising from the use of chemicals in food products. Passage of the "Pesticide Amendment," in 1954, and the "Food Additives Amendment," in 1958 (to the Food, Drug and Cosmetical Act, 1938), pro- vided a much-needed definition of the positions held by chemical manufactur- ers, food processors, and Government, < regarding food chemicals. Further infor- mation on the subject is to be found in a good review by Frey (12), which con- tains an extensive bibliography. Much 12 further clarification and interpretation of is certain that the importance of chemi- the food additives legislation will un- cals in the food industry is only begin- doubtedly be provided in the future; it ning to be realized. LITERATURE CITED 1. United States Department of Agriculture, Bureau of Agricultural Economics. 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept.; Suppl. July 1958). 2. Clark, F. 1956. Family spending for food. Cereal Sci. Today, 1, 155. 3. Harrel, C. G., and B. M. Dirks 1955. Cereal and cereal products. In Handbook of Food and Agriculture, ed. by F. C. Blanck. Reinhold Publishing Corporation, New York. 4. United States Department of Commerce 1949. Census of manufacturers. Series NC61T-1, March. 5. Engledow, Sir Frank 1956. Food manufacture should be more scientific. Food Manuf., 31, (8), 330. 6. Lehman, A. J., W. I. Patterson, B. Davidow, E. C. Hagan, G. Woodward, E. P. Laug, J. P. Frawley, O. G. Fitzhugh, A. R. Bourke, J. H. Draize, A. A. Nelson, and B. J. Vos 1955. Procedures for the appraisal of the toxicity of chemicals in food, drugs, and cosmetics. Food, Drug, Cosmetic Law Jour., 10, 679. 7. Food Protection Committee, Food and Nutrition Board 1952. Safe use of chemical additives in foods. National Research Council, Washington, D.C., Dec. 8. Food Protection Committee, Food and Nutrition Board 1954. Principles and procedures for evaluating the safety of intentional chemical additives in foods. National Research Council, Washington, D.C., Nov. 9. Hazelton, L. W. 1957. Biological evaluation of agricultural and food chemicals. Jour. Agr. Food Chem. 5, 336. 10. MlCKELSEN, OLAF 1957. Chemicals and food processing. Nutrition Rev. 15, 129. 11. United States Department of Commerce, Bureau of Laror Statistics 1959. Employment and earnings. Washington, D.C., Feb. 12. Frey, C. N. 1955. Chemicals in foods. In Handbook of Food and Agriculture, ed. by F. C. Blanck, Reinhold Publishing Corporation, New York. 13. Aser, B. L. 1958. The food industry in a changing world. Food Tech. 12, 493. r 13 ] PART II— PROBLEMS OF THE FOOD INDUSTRY General Food Problems 1. The control of microbial spoilage is the most critical problem facing the food industry today. In considering ways to meet this problem, it should be noted that in most instances absolute sterility of food is not a necessary condition for its preservation. Although the develop- ment of a process that would produce absolute sterility would be of value, many kinds of food deterioration are caused by the growth of a single species of or- ganism, in which case selective control of that organism would solve the prob- lem. Inactivation of strict aerobes, for instance, would be unnecessary in sealed containers; attention needs to be turned only to the inactivation of those organ- isms which grow and lead to deteriora- tion under the given environmental con- ditions. 2. Another major difficulty lies in find- ing a bactericide or bacteriostatic agent that is nontoxic or relatively nontoxic to man. Thus, it would be highly desirable to develop a compound that would de- stroy the microorganisms and then de- compose to nontoxic products, either on cooking or after application. Aureomy- cin, hydrogen peroxide, propylene oxide, and peracetic acid are such compounds which have been used commercially or experimentally in foods. '.\. In the production of commodities such as wine, beer, pickles, and cheese, the development of certain specific or- ganisms is desirable. It would be of value to the producers to have an agent that would allow the development of the de- sirable organisms, but no others. A knowledge of the nutritional require- ments of both desirable and undesirable species might lead to the development of antimetabolites which would inhibit the growth of those which are unbeneficial. These antimetabolites might be struc- tural analogs of the vitamins and amino acids required for the growth of the spoilage organisms. It should be real- ized, however, that such an approach might not provide a permanent solution to the problem, because of the possibility of the spontaneous mutation and adapta- tion of the organisms involved. 4. In nonacid foods, such as canned vegetables, meat, and fish, an excessive amount of heat is required to inactivate bacterial spores. Such heat treatment leads to changes in flavor, texture, and color. To obtain a more acceptable prod- uct, it would be helpful to have a safe agent that would inhibit spore germina- tion and thus make it possible to reduce the period of treatment. In addition, an agent which would replace the pasteuriza- tion which many of our foods undergo would be of value to the industry. Bac- [14] teriostatic agents, such as benzoic acid and sorbic acid, are effective in acid media, but no such agent has been dis- covered which is satisfactory under neu- tral or alkaline conditions. 5. Although a number of bactericides are presently available for application to fresh fruits and vegetables, there is still no really effective agent which will con- trol microbial spoilage throughout the marketing period. 6. At present, the only practical means of inactivating enzymes which may lead to deteriorative changes in food, is through the application of heat. The deli- cate flavor of many food items is partially lost by such treatment, however, and a suitable "antienzyme" might help to re- tain flavor quality. There are many chemicals which are known to inactivate enzymes, but most of these are impracti- cal for food use. 7. Non-enzymatic browning, assumed to be a carbonylamine reaction, is a chemical deterioration which occurs in almost every food commodity, and for which no effective means of control has been found. In some instances, sulfur dioxide is used to retard browning, but this gas imparts an undesirable odor and flavor. In the production of egg solids, browning is inhibited by oxidation of glucose to gluconic acid by the action of the enzyme glucose oxidase, and such an approach may well have application in many other food fields. 8. Lipid oxidation is another important type of chemical deterioration. Although a number of good antioxidants are pres- ently available, not all have been specifi- cally approved in many fat-containing foods. The presence of copper and iron in these foods is known to catalyze oxida- tion. Citric acid and phosphoric acid are permitted in some foods to reduce the action of these ions, but chemicals more effective than these are needed. 9. The fumigants currently in use are effective against insects when properly applied, but an agent which would pre- vent insect contamination would be valuable; the need for repeated fumiga- tion would thus be eliminated. 10. Because a number of synthetic food dyes have recently been removed from the list of acceptable food additives, new sources of coloring matter are needed. 11. There are as yet no effective thin- ning agents which would obviate the ex- cessive dilution with water of certain foods which require thinning, although there are some satisfactory thickening agents available. A look at nature may suggest a rational approach to the development of food ad- ditives. There exists a wide range of natural colors, one of which is currently being synthesized for use in food (beta- carotene) ; perhaps other colors can be made synthetically. There are also many natural antioxidants, natural fungistats which enable plants to resist disease, and some food items which contain natural insect attractants or repellants. These constituents may be quite complex, but the structural features essential to their physiological activity might provide in- formation which would lead to synthesis of less complicated active compounds. Whenever the use of food additives is considered, the problem of how best to incorporate the agent into the product must be solved. Because of the power of living things to detoxify foreign chemi- cals, little research has been done on the possibility of distributing additives throughout the food source prior to har- vest or slaughter. In experiments making use of the circulatory system of animals to distribute antibiotics or chemicals, it was found that only small percentages of the agents accumulated, although the use of potato leaf sprays containing maleic hydrazide has proved to be successful, and does inhibit the sprouting of potato tubers long after harvest. Although solutions to many such food problems are known, there are often practical considerations that make the [15] knowledge difficult to apply. For ex- ample, adequate refrigeration would re- duce much of the microbial spoilage in fresh fruits and vegetables, but ideal storage conditions seldom are available under the present marketing system. Thus, to minimize loss as these items pass through marketing channels, some simpler and more reliable method of preservation must be sought. Precooked frozen items present a particularly seri- ous potential hazard under improper handling. The ultimate "problem," of course, is the consumer. His tastes vary from sea- son to season, year to year, and to some extent, geographically from place to place. In general, however, his food must fit his budget, appear attractive, appeal to taste and smell, and be nutritious. Above all, it must "suit his fancy." Any means by which these requirements are served will be of interest and benefit to the food industry. The food industry is constantly faced with the dual problem of meeting con- sumer demands and at the same time realizing a reasonable profit. Some of the major problems which beset pro- ducers in their endeavor to accomplish this end, are presented in the following pages. LITERATURE CITED A-l. Blanck, F. C. 1955. Handbook of Food and Agriculture. Reinhold Publishing Corporation, New York. A-2. Jacobs, M. B. 1951. The Chemistry and Technology of Food and Food Products, second edition. Interscience Publishers, Inc., New York. A-3. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the U.S. 1909-1952. Agriculture Handbook No. 62 (Sept.; Suppl. Oct. 1955, July 1958). j B | Meat 1. Introduction During the 1947-49 period, 24 cents (and in 1957, 25 cents) of every food dollar was spent for meat, the most ex- pensive item on the food budget. Statis- tics on the consumption of meat, fish, and poultry during this period show that these foods provided 12.6 per cent of the energy, 29.2 per cent of the protein, and 22 per cent of the fat in the American diet. They also provided 24.1 per cent of the iron, 22. per cent of the thiamine, lo.l per <<-nt of the riboflavin, and 41.9 per cent of the niacin (R-l). The gradual rise in meat consumption has been indicated previously. In 1957, meat production totaled 26.9 billion pounds in the United States, and the scale of meat processing operations can be gauged by the fact that in 1955 the meat industry's two major companies (Swift and Armour) were rated among the top ten corporations in the United States. Figure B-l shows the per capita consump- tion of the various animal meats (B-l). It can be seen from this figure that dur- ing the last several years beef consump- tion has exceeded that of pork, while the 16 1 o u t- O u Q z z> o a. 1955 1957 Fig. B-l. U.S. per capita consumption of meat (primary distribution weight). use of veal, lamb, and mutton has re- mained almost constant. The fundamental steps (bleeding, and removal of stomach, intestines, hide, hoofs, and horns) involved in the proc- essing of animals have remained un- changed for many years, although with the industrialization and growth of the meat industry, refinements in processing and mechanical handling have been developed. Actually, there is a relatively limited amount of processing necessary for fresh meat. The animal is slaughtered and cooled [the slaughtering procedure varies with the type of animal ( B-3. B-4)], and most of the carcasses are moved out of the processing plant at this point. The amount of aging depends on the purchasers' needs. The highest grade of beef, primarily for the restaurant trade, may be aged for as much as 4 to 6 weeks, but with the recent trend toward [17] prepackaging, most of the meat is sold within 1 to 2 weeks after slaughter. It has been predicted that within 5 years, 30 to 50 per cent of the meat sold will be pre- packaged and frozen (B-5). 2. Commodity problems a. Fresh meat In his 1955 article in Advances in Food Research, Ay res (B-6) discusses slaughtering methods in relation to microbiological contamination. He sug- gests that a study be made of the efficacy of detergents and sanitizing agents in removing filth and microorganisms from animals both prior to and during slaughtering operations in order to re- duce microbial contamination. After dressing, carcasses are chilled to firm the flesh, minimize shrinkage, delay the growth of undesirable organisms, and retard chemical deterioration. The prin- cipal types of microbial spoilage that can occur in refrigerated fresh meat are off- odor and slime, deep spoilage, and mold discoloration. Mold is no longer a major problem since meat is seldom aged very long. A number of investigations have been conducted on the use of antibiotics to delay microbiological spoilage in meat (B-7, B-8, B-9, B-10, B-ll). Weiser and co-workers (B-12) infused a carcass with antibiotics through the circulatory sys- tem of the animal after it was bled, and showed that this method reduced deep spoilage in the meat. Such use of anti- biotics by meat producers is now per- mitted in some countries, but not in the United States; however, Burton (B-13) has predicted that it will be used here in the near future. Perhaps there are other chemicals which could also be employed to control the growth of spoilage organisms. Future research on chemical control of microorganisms should take into con- sideration the extensive effort which has been devoted to the preservation of meats by radiation. The present difficulty with this procedure is that off-odors develop when sterilizing dosages are used. During the cooling and aging of meat, packing house operations are confronted with the problem of shrinkage (loss in weight). The weight lost amounts to as Aging rooms of a large meat warehouse. (Safeway News photo.) much as 2.5 per cent, even under opti- mum conditions. Considering that ap- proximately 25 billion pounds of meat is marketed annually, shrinkage can be very expensive, and a method for reduc- ing this loss would be of vital interest to meat packers. A recent publication sug- gested as a solution to this problem the use of a coating agent during aging (B-14). However, more experimental work needs to be done before this proce- dure can come into general commercial use. Although tenderness in meat is highly desirable and a considerable amount of research has been done on the factors which contribute to tenderness, no com- mercially satisfactory method has been evolved for insuring this quality. Enzyme preparations which can be applied before cooking are widely available, but for full effectiveness the tenderizer must be physically incorporated with the meat, and this is a difficult and time-consuming process (B-16). It has been known for a long time that aging tenderizes meat (B-15), and this has been attributed to the action of proteolytic enzymes. To speed aging, higher storage temperatures (65 to 68°F. for 48 hours) may be used; the concur- rent growth of microorganisms may be retarded by use of ultraviolet irradiation. Further investigations should be con- ducted on high-temperature aging, in combination with infusion of the carcass with antibiotics. Also it has been shown that tenderness is related to the presence of certain ions in the meat "juice" (B-17, B-18) . This factor deserves further in- vestigation. Color is a most important factor in meat quality. The desirable red color deteriorates rapidly to an unappetizing gray. This is especially true of prepack- aged fresh meat. Actually, there are several reasons for the loss of color: Oxygen, light, dehydration, and micro- bial action can all produce color changes (B-19). Coleman and Steffen (B-20) have patented the use of the addition of niacin (nicotinic acid) for the retention of a uniform bright-red color in fresh meat. The addition of niacin is not presently permitted under Federal regu- lation, but it is used in some meats that are not transported in interstate com- merce. Ascorbic acid (Vitamin C) has also been suggested as an additive for maintaining proper color; Watts and Lehmann (B-21) state that 0.02 per cent of ascorbic acid is effective in maintain- ing color. The prepackaging of fresh meat has led to the problem of "weepage," the ex- cessive loss of liquid from the meat. This difficulty also arises in pork through the development of "soft muscle," which causes leakage, and for which there is no remedy at present. It would be most help- ful if a suitable chemical "weepage"- deterrent could be developed. "Dark-cutting" beef, especially young beef carcasses, has been a problem of long standing to the meat industry. It may appear throughout a meat cut, or it may occur in only a portion of the cut, resulting in a two-toned coloration. The dark color has been attributed to the inability of meat pigment to complex with oxygen to give the desirable red color after cutting. The condition appears to be related to stress prior to slaughter although the exact cause is unknown. A solution to this problem might lie in the development of an acceptable additive that would induce the formation of an oxygen-pigment complex, or in the for- mation of a pigment having the desired red color. b. Cured meat The original purpose of curing and smoking meat was to preserve it. Today, however, meat is cured primarily for taste. In fact, many of the mild-cured products cannot be kept long at room temperatures. The ingredients permitted for curing are: salt, sugar, vinegar, and [19] certain nitrate, nitrite, and phosphate salts. Nitrate and nitrite are used in process- ing cured meat to produce the character- istic red color when it is heated. This heat-stable color is due to a complex con- taining nitric oxide, and a serious limita- tion is a susceptibility to light, which causes it to change to an unacceptable gray. Ascorbic acid added to the curing mixture is reported to retard fading (B-22). It would be desirable to find a more stable complexing agent for cured meat color which would not break down so readily when exposed to light. Rancidity is still a problem in bacon. Although a number of antioxidants are available today, it has been found difficult to incorporate them into the bacon. The growth of molds, yeast, and micro- cocci can lead to considerable loss during the distribution and marketing of frank- furters. Ogilvy and Ayres (B-23) have shown that the growth of these organ- isms is retarded by a partial atmosphere of carbon dioxide. The development of an additive that could be applied to the surface of the frankfurter would be more desirable than gas-packing. c. Frozen meats The prediction that sales of prepack- aged frozen meat will increase was men- tioned earlier. Only within the last few years has there been any real effort placed on the sale of these products (B-24, B-25). The freezer life of frozen beef is about one year, but frozen pork products, on the other hand, retain their good quality only about 6 months. A method for extending shelf life is needed. d. Canned meats Objections to heat-processed canned meat are the "soft, mushy" texture and "canned meat" flavor. These undesirable changes arise from the prolonged treat- ment required to obtain sterility. Drastic heat treatments are necessary to in- activate the resistant spores of spoilage and food poisoning organisms. Such processing cannot be applied to all meat products. For example, since a sterilizing heat treatment has an adverse effect on their quality, large canned hams must be pasteurized and kept under refrigeration. A method for reducing the amount of heat required to control the growth of spoilage organisms would be most wel- come. The stability of many microbial spores under heat has stimulated investi- gations on the factors affecting such thermal resistance (B-26) , and on factors influencing sporulation and germination (B-27). The feasibility of using chemi- cals to prevent spore germination or to decrease thermal resistance should be investigated further. LITERATURE CITED B-l. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept.; Suppl. July 1958). B-2. Anon. 1956. Directory of the 500 largest industrial corporations. Special insert, In Fortune, 54, (1), July. B-3. Jensen, L. B. 1949. Meat and meat foods. The Ronald Press Co., New York. B4. Urbain, W. M. 1951. Meat and meat products. In the Chemistry and Technology of Food and Food Products, ed. by M. B. Jacobs. Interscience Publishers, Incorporated, New York. B-5. Anon. 1956. Thirty to fifty per cent frozen prepackaged meat in five years. Quick Frozen Foods, 18(6), 117, Jan. [20] B-6. Ayres, J. C. 1955. Microbiological implications in the handling, slaughtering, and dressing of meat animals. Advances in Food Research, 6, 109. B-7. Tarr, H. L. A., J. W. Boyd, and H. M. Bissett, Jr. 1954. Experimental preservation of fish and beef with antibiotics. Jour. Agr. Food Chem. 2, 372. B-8. Niven, C. F., Jr., and W. R. Chesbro 1956. Antibiotics and irradiation in meat preservation. Proceedings 8th Conference on Research, Amer. Meat Inst., March. B-9. Anon. 1956. Antibiotics keep steaks young. Chem. Eng. News 34, 5392. B-10. Ingram, M., E. M. Barnes, and J. M. Shewan 1956. Problems in the use of antibiotics for preserving meat and fish. Food Sci. Abs. 28, 121. B-ll. Goldberg, H. S., H. H. Weiser, and F. E. Deatherage 1953. Studies on meat. IV. Use of antibiotics in preservation of fresh beef. Food Tech. 7, 165. B-12. Weiser, H. H., H. S. Goldberg, V. R. Cahill, L. E. Kunkle, and F. E. Deatherage 1953. Observation of fresh meat processed by infusion of antibiotics. Food Tech. 7, 495. B-13. Bowman, B. 1955. Cyanamid's Burton sees early retailing of antibiotic meats. Food Field Reporter 23(24), 36. B-14. Anon. 1956. New packaging idea for frozen meat. Western Meat Industry 2(1) 30. B-15. Paul, P. C, and L. J. Bratzler 1955. Studies on tenderness of beef. II. Varying storage times and conditions. Food Res. 20, 626. B-16. Tappel, A. L., D. S. Miyada, C. Sterling, and V. P. Maier 1956. Meat tenderization. II. Factors affecting the tenderization of beef by papain. Food Res. 21,375. B-17. Wierbicki, E, L. E. Kunkle, V. R. Cahill, and F. E. Deatherage 1954. The relation of tenderness to protein alterations during post-mortem aging. Food Tech. 8, 506. B-18. Suri, B. R., and H. W. Schultz 1956. Chemical and physical changes in isolated beef muscle tenderized by infusion with sodium chloride. Presented at the 16th Annual Meeting of the Institute of Food Technologists, St. Louis, Missouri. B-19. Watts, B. M. 1954. Oxidative rancidity and discoloration in meat. Advances in Food Research 5, 1. B-20. Coleman, H. M., A. H. Steffen, and E. W. Hopkins 1951. Improving the color of animal meat and blood. U. S. Patent 2,541,572. B-21. Watts, B. M., and B. T. Lehmann 1952. Ascorbic acid and meat color. Food Tech. 6, 194. B-22. Brockmann, M. C, and R. E. Morse 1953. Ascorbic acid aids cured meat color. Proc. 5th Conf. on Research, Amer. Meat Inst., March. B-23. Ogilvy, W. S., and J. C. Ayres 1953. Post-mortem changes in stored meats. V. Effect of carbon dioxide on microbial growth of stored frankfurters, and characteristics of some microorganisms isolated from them. Food Res. 18, 121. B-24. Anon. 1956. Swift prepackaged line requires little change. Food Field Reporter, 24(1), 1. B-25. Anon. 1956. Armour to launch frozen meat line. Food Field Reporter, 24(6) , 1. B-26. Sugiyama, H. 1953. Chemical and physical factors affecting the thermal resistance of bacterial spores. In The Quality and Stability of Canned Meats, ed. by R. G. Tisher, J. M. Blair, and M. S. Peter- son. Quartermaster Food and Container Inst., Chicago, Illinois. B-27. Williams, 0. B. 1953. Factors causing sporulation and vegetation of spoilage organisms in canned meats. In The Quality and Stability of Canned Meats, ed. by R. G. Tisher, J. M. Blair, and M. S. Peter- son. Quartermaster Food and Container Inst., Chicago, Illinois. B-28. Erdman, A. M., and B. M. Watts 1957. Spectrophotometric determination of color change in cured meat. Jour. Agr. Food Chem. 5, 453. [21] 1. Introduction Chicken and turkey, traditionally holi- day fare, are now being eaten throughout the year. This trend is apparent from Figure C-l, which illustrates in particular the phenomenal increase in the consump- tion of chicken (C-l). The use of turkey has increased also, but at a lower rate. By 1957, the average person in this country was eating 25.6 pounds of "ready-to- cook" chicken and almost 6 pounds of "ready-to-cook" turkey per year. The rise in per capita poultry con- sumption can be primarily attributed to lower cost, better quality, and greater convenience, which advantages accrued to the consumer as the result of lower mortality and improved breeding, feed conversion, and keeping quality, as well as more extensive use of automation dur- ing processin '. Although chickens are raised in every part of the country, over 40 per cent of the commercial broiler production is centered in the South Atlantic states. It is not unusual in these areas to find enter- prises handling as many as 100,000 birds. The processing of poultry consists of killing, bleeding, removing feathers, and eviscerating. More detailed information on these procedures can be found in the articles by Pennington (C-2) and by Lineweaver and Klose (C-3). Most of the processed chickens are sold chilled, while a major part of the turkey production is marketed in the frozen state. Since about 1950, increasing amounts of convenience items such as precooked frozen poultry products (TV dinners, chicken and turkey pies, chicken a la king, etc.) have appeared on the market, (.'aimed poultry items represent about 5 per cent of the total production as estimated by the volume certified for canning (C-3). 2. General problems At the annual meeting of the Institute of American Poultry Industries Research Council, comprised of members from the industry, government, and education, current problems of the poultry and egg industries are discussed and recommen- dations made to the U.S.D.A. for indus- trial research needs. Although many of these problems may not relate directly to the use of chemicals, it might be of inter- est to refer to the council's recommenda- tions. Processing and storage pose a number of specific problems. During processing, for example, unsightly bruises may develop from injuries that occur when the birds struggle during transport and slaughter. Electric shock applied to the birds before they are killed will reduce bruising. The possible use of chemicals to immobilize poultry before slaughter merits investigation. A blanket of carbon dioxide sometimes is used to immobilize swine prior to killing; perhaps a similar approach could be used in poultry proc- essing. The birds usually are "scalded" by being sprayed or dipped in water of specified temperatures and times. The "scald water" often contains softening and wetting agents which facilitate the process. The feathers generally are re- moved by placing the scalded bird against moving rubber fingers mounted on a rotated drum, but it has been shown that excessive beating by these fingers toughens poultry meat. Perhaps a chemi- cal agent could be found which, when added to the scald water, would further [22 1 26 24 22 20 £ 18 to o z Z> O 16 14 12 1925 TURKEY DUCKS and GEESE 1930 1935 1940 YEAR 1945 1950 1955 1957 Fig. C-l. U.S. per capita consumption of poultry (approximate retail weight). facilitate the removal of feathers without impairing the bird's tenderness. Another approach might be to induce feather molting before processing by means of a chemical which could be fed several days ahead of time. Another processing problem is bleed- ing. The appearance of the carcass is dependent on the thoroughness of bleed- ing (C-4) , and although salt is sometimes added to the chilling tanks to draw blood, this practice is not entirely satisfactory. [23] Here, again, appropriate chemicals might solve the difficulty. The shelf life of chilled poultry has been slightly lengthened by the use of antibiotics (C-5, C-6, C-7), although this has decreased appreciably since it was originally reported. Some believe that this decrease is due to the development of resistant organisms. If this is so, oc- casional changes to new antibiotics, or perhaps even to synthetic chemicals, may be necessary in order to control the growth of spoilage organisms. Another approach to the problem is to reduce the initial bacterial load at the time of pack- aging. Any method of lowering the num- ber of organisms originally present would, of course, increase shelf life. Ayres' (C-8) suggestion regarding in- vestigation of a wider use of detergent and sanitizing agents during processing also may be applicable. The Institute of American Poultry Industries Research Council has recom- mended to the U.S.D.A. Poultry Advi- sory Committee that research on tender- ness in poultry, particularly frozen turkey and chicken, be continued and expanded (C-9, C-10, C-ll) . The age of the bird is the first consideration. However, such aspects of processing as aging after kill- ing, scalding temperatures, excessive soaking, scalding water, and excessive beating during feather removal all affect the tenderness of poultry meat (C-12). Perhaps chemicals could help alleviate this problem. Precooked frozen poultry items have brought complaints of lack of flavor and off-flavor such as rancidity or stale- ness. To prevent rancidity, wider use should be made of the heat-stable anti- oxidants. Another solution to this prob- lem is the possibility of adding anti- oxidants to the feed. Some work has already been done on this approach, but because of the amount of antioxidant needed, the practice is now economically unfeasible (C-13, C-14). The problem of improving the flavor of frozen precooked chicken and turkey will require consider- able research, and perhaps additives can be found which will be suitable for the purpose. A number of articles have been pub- lished on the potential hazards of frozen precooked poultry items (C-15, C-16, C-17, C-18), which provide excellent media for the growth of pathogenic organisms. Under proper processing and handling procedures, there is no danger; the hazard lies in allowing these items to stand after they have been prepared and before they are frozen, or allowing them to stand for a long time after thawing. An agent is needed which will prevent the growth of hazardous organisms under such conditions. LITERATURE CITED C-l. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept.; Suppl. July 1958). C-2. Pennington, M. E. L951. Poultry and eggs. In The Chemistry and Technology of Food and Food Products, ed. by M. B. Jacobs. Interscience Publishers, Inc., New York. C-3. Li ^ i w i \ \ i;k, H., and A . A . Klose 1955. Poultry products. In Handbook of Food and Agriculture, ed. by F. C. Blanek. Reinhold Publishing Corporation, New York. C4. Davis, I.. L., and M. E. Coe 1954. Bleeding of chicken during the killing operation. Poultry Sci. 33, 616. C-5. Broqi ist, II. P., A. K. Kohler, and W. H. Miller L956. Retardation of poultry spoilage by processing with chlorotetracycline. .lour. Agr. Food Chem. 4, 1030. [ 24 1 C-6. Ziegler, F., and W. J. Stadelman 1955. The effect of aureomycin treatment on the shelf life of fresh poultry meat. Food Tech. 9, 107. C-7. Kohler, A. R., W. H. Miller, and H. P. Broquist 1955. Aureomycin (chlorotetracycline) and control of poultry spoilage. Food Tech. 9, 151. C-8. Ayres, J. C. 1955. Microbiological implications in the handling, slaughtering, and dressing of meat animals. Advances in Food Research, 6, 109. C-9. Anon. 1955. Why are turkeys tough? Poultry Processing and Marketing, 16(11), 20. C-10. Anon. 1956. Poultry committee asks research for healthy birds and superior products. Poultry Process- ing and Marketing, 62 (3) , 15. C-ll. Anon. 1955. Research on the toughness of frozen turkey and chickens. Amer. Egg and Poultry Rev. 17(10), 20. C-12. Klose, A. A. 1956. Tenderness depends on processing. Poultry Processing and Marketing, 62(11), 10. C-13. Criddle, J. E., and A. F. Morgan 1957. The effect of tocopherol feeding on tocopherol and peroxide content of turkey tissue. Federation Proc. 6, 247. C-14. Kummerow, F. A., J. Hite, and S. Kloxin 1948. Fat rancidity in eviscerated poultry. Poultry Sci. 27, 689. C-15. Straka, R. P., and F. M. Combes 1952. Survival and multiplication of Micrococcus pyogenes var. Food Res. 17, 448. C-16. Proctor, B. E., and A. W. Phillips, Jr. 1947. Microbiological aspects of frozen precooked foods Refrig. Eng., 53, 30 C-17. Saleh, M. A., and Z. J. Ordal 1955. Studies on growth and production of Clostridium botulinum in precooked frozen foods. I. Some factors affecting growth and toxin production. Food Res. 20, 332. C-18. Straka, R. P., and J. L. Stokes 1956. Microbiological hazards of precooked frozen foods. Quick Frozen Foods, 18, (7), 182. Fish and Fish Products 1. Introduction Fish and fish products have been esti- mated to supply the world with approxi- mately 3 per cent of its food. This figure is very close to the percentage of United States consumption, but in countries such as Norway and Japan, the proportion may be as high as 10 per cent. Actually, the food potential of the ocean has barely been tapped. And if one considers the limitations of the world's land areas for agricultural development, it is clear that improved methods of fishing and fish preservation will contribute to a vastly increased use of food from the sea in the future. During 1956, approximately 5.2 bil- lion pounds of fish were caught in the United States and Alaska, with a value of more than 400 million dollars. Of this catch, almost 30 per cent was disposed of in fresh and frozen form, 23 per cent canned, 1.7 per cent cured, and the re- mainder converted to by-products or used as bait. The per capita consumption of fresh, frozen, canned, and cured fish and shellfish is shown in Figure D-l (D-l). [25] FRESH and FROZEN "1™ 7 6 - \ * \ H \ '• A I ••XX \ • m ^^^ \\ysj V^x" 5 \ r : - \ / • • * * • CO \ / . •• * • ..• Q x^*.' v ♦. ^ Z o 4 - •■•■•* ♦ » * •'.canned/ • • ♦ • *• • Q- • • • • • \ .' 4 • • • • • ♦ * • • t * • • • • ■ ■ • • • • • • • ■ 3 • • • • • • • • • • • • • • • ■i • • • t ■ ■ ■ 2 V 1 - X CURED 1 ■ i 1925 1930 1935 1940 YEAR 1945 1950 1955 1957 Fig. D-l . U.S. per capita consumption of fish and shell fish. Detailed information on fishery statistics of the United States can be found in a publication issued by the Fish and Wild- life Service (D-2), and an excellent re- view of the household consumption of fishery products is available (D-21). The important geographical areas in the United States where fish are landed and processed are Southern California (tuna), the Pacific Northwest (salmon), the Gulf Stales (shrimp), and New Eng- land (cod, sardines, etc. I . Considerable research is being carried «»ul in tlic I niled States, as well as in Canada, Greal Britain. Japan, and Nor- way, on improving fish and fish products. Most of the research in the United States has been carried out by government agencies and universities. 2. Commodity problems a. Fresh fish The most important problem with fresh fish is microbial spoilage, which is difficult to control because the organisms involved are pschrophiles, which flourish at low temperatures. In fact, some con- tinue to grow at temperatures as low as -7.5°C. (D-3), and their rate of growth can double when the temperature is [26| raised from -1° to 2.5°C. (D-4) . In some cases, the fishing grounds are so far from port, and/or the time required to catch a full load of fish is sufficiently long to allow spoilage organisms to grow. Be- cause of the practical difficulty involved in maintaining adequate temperatures (at which the growth of psychrophilic organisms is retarded) other means of control have been sought. Numerous in- vestigations have been carried out on the use of chemicals for this purpose. The subject has recently been reviewed in two articles (D-5, D-6). Among the chemicals that have been tried, probably the most effective is anti- biotic treatment (D-7, D-8). In 1956, Ingram (D-9) reviewed the use of anti- biotics for the preservation of meat and fish and found that resistant organisms can develop if the antibiotic is used at bacteriostatic concentrations. In addition to antibiotics sodium nitrite has also been found effective in retarding micro- bial spoilage. The use of both of the>;e agents is now permitted in Canada, but only Aureomycin is permitted in the United States. Storage under carbon dioxide also has been investigated, and it has been found that an atmosphere containing 50 per cent carbon dioxide retards microbial spoilage (D-10). The use of ethylene oxide (I) and propylene oxide (II) has been investigated, and both have been found to be extremely effective against microbial spoilage, however, the delete- CH.-CH 2 - v-l 12 CH,-CH-CH V (i) (id Red Chinook salmon being unloaded at a frozen fish plant in Seattle. (Safeway News photo.) X^^Vhwii.^-^^jj^jivMv;^.. ■'..., v ^ . ..'.■■■ It^; / rious effect on the quality rules out their use. Tarr (D-5) has suggested further in- vestigations on the nutrient requirements of the spoilage organisms in fish. Al- though antibiotics and nitrite are quite effective in controlling microbial spoil- age in fish, the search for even more ef- fective agents should not be abandoned. b. Frozen fish and shellfish During 1954, approximately 600 mil- lion pounds of fish and shellfish were frozen, of which 19 per cent was shrimp, 15 per cent ocean perch, 11 per cent hali- but, 10 per cent whiting, 7 per cent bait and animal food, and 7 per cent haddock. The proper freezing of fish prevents microbial spoilage but leads to other problems. According to Tarr (D-ll), the single most serious deterioration which takes place in frozen fish is denaturation of the protein myosin. The exact nature of this deterioration, which may be responsible for the toughening and drying observed in frozen fish and shellfish, is still un- known, and the only available method for combating it is to store frozen fish below -20°C. Another problem in the preservation of frozen fish is that oxidation takes place which can lead to loss in flavor, develop- ment of off-flavors through oxidative rancidity, and discoloration of white- flesh fish or fading of highly pigmented fish, such as salmon (D-12). The addi- tion of an antioxidant retards deteriora- tion (D-13, D-14), but there is contro- versy in the industry over its possibly unbeneficial effects. Undesirable results from antioxidants have been attributed to insufficient treatment and to improper handling of the fish; thus, an antioxidant is needed which will be really effective (D-15). Large quantities of carcass fish may be stored frozen until sold or processed. After freezing, the fish is frequently dipped in water; the adhering water freezes to form a protective coating of ice. This coating, referred to as glaze, prevents dehydration and retards oxida- tion. One difficulty with this process is that the glaze must be reapplied from time to time. An additional difficulty is that pores develop through which oil may seep to the surface and rancidify. Numer- ous processors have their own formulas for improving the glaze, but the inherent problems still remain. A substitute for glaze is needed; a suitable plastic coat- ing might, perhaps, be the answer. Another problem of frozen fish is excessive "drip" on thawing; in some extreme cases as much as 10 per cent of the fish's weight may be lost. It would be highly desirable to retain more of this liquid in the flesh so as to reduce "dry- ness" after cooking. Polyphosphates, which are used to retain juice in meat, might find use in this connection. denatured globin N N '/ \ N Fe N (III) COOH [28 1 c. Canned fish Discoloration, common in the canning of light-colored fish, has been attributed mainly to the Maillard reaction (between ribose and amine) . Tarr (D-16) has sug- gested that this problem might be solved if ribose could be removed by enzymatic action just as glucose is removed in the production of dehydrated eggs. A problem in grated canned tuna is re- tention of the light pink color ; it is easily oxidized to tan or brown. A method for restoring or maintaining its color is highly desirable. Brown and Tappell (D-17) have reported that this pink color is due to a pigment-niacin complex (HI). During the past few years, there have been sporadic occurrences of black dis- coloration in solid-pack tuna, apparently due to the formation of ferrous sulfide and occasionally, of tin sulfide (D-18). A similar discoloration has been occur- ring in canned wet-pack shrimp (D-19). d. Cured fish When smoked, salted, or dehydrated fish is stored, the moisture content may be sufficient to support the growth of mold. Boyd and Tarr (D-20) have re- ported that such growth on smoked fish is effectively delayed by the use of sorbic acid (IV). CH :{ - CH = CH - CH = CH - COOH. (IV) A problem in the storage of salted fish is "rusting." The actual nature of rusting is unknown, but it may be due to fat oxidation, and perhaps to the interaction of fat with proteins. In some establish- ments, losses of salted mackerel due to rusting amount to as much as 25 per cent. An antioxidant or a combination of anti- oxidants might be developed which would help to relieve this difficulty. LITERATURE CITED D-l. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept. Suppl. July 1958). D-2. United States Department of the Interior, Fish and Wildlife Service 1954. Fishery Statistics of United States, 1954. Statistical Digest No. 39; also more recent issues. D-3. Bedford, R. H. 1933. Marine bacteria of the northern Pacific Ocean. The temperature range of growth. Contribu- tion Canad. Biol, and Fisheries 7, 491. D-4. Hess, E. 1932. The influence of low temperatures above freezing upon the rate of autolytic and bacterial decomposition of haddock muscle. Contribution Canad. Biol, and Fisheries, 7, 147. D-5. Tarr, H. L. A. 1954. Microbiological deterioration of fish post-mortem, its detection and control. Bacteriol. Rev., 18, 1. D-6. Tomiyasu, Y., and B. Zenitani 1957. Spoilage of fish and its preservation by chemical agents. Advances in Food Research 7, 41. D-7. Boyd, J. W., H. M. Bluhm, C. R. Muirhead, and H. L. A. Tarr 1956. Use of antibiotics for the preservation of fish and sea foods. Amer. Jour. Public Health, 46, (12), 1531. D-8. Firman, M. C, A. Abbey, M. A. Darken, A. R. Kohler, and S. D. Upham 1956. Effect of aureomycin (chlorotetracycline) on fish freshness. Food Tech. 10 (8), 381. D-9. Ingram, M., E. M. Barnes, and J. M. Shewan 1956. Problems in the use of antibiotics for preserving meat and fish. Food Sci. Abs. 28, 121. D-10. Stansby, M. E., and F. P. Griffiths 1935. Carbon dioxide in handling of fresh fish. Ind. Eng. Chem. 27, 1452. [29] dii.Tarr, h. l.a. 1955. Sea foods. In Handbook of Food and Agriculture, ed. by F. C. Blanck. Reinhold Publishing Corporation, New York. D-12. Brown, W., A. L. Tappel, and M. E. Stansby 1956. Oxidative deterioration in fish and fishery products. Com. Fisheries Rev. 18, (2), 10. D-13. Anon. 1955. Antioxidant mixture used in frozen fish. Food Field Reporter, 23 (11) , 28. D-14. Watts, B. M. 1955. Deteriorative changes in frozen shrimp and their inhibition. Food Tech. 9, 632. D-15. Tarr, H. L. A. 1956. Research on fish preservation and processing. Food Manuf. 31, (6) , 239. D-16. Tarr, H. L. A. 1954. Maillard reaction in flesh food. Food Tech. 8, 15. D-17. Brown, W. D., and A. L. Tappel 1957. Identification of the pink pigment of canned tuna. Food Res. 22, 214. D-18. Pigott, G., and M. E. Stansby 1955. Iron sulfide discoloration of tuna cans. Com. Fisheries Rev. 17 (10), 34. D-19. Landgraf, R. G., Jr. 1956. Factors influencing the sporadic development of discoloration in canned wet-pack shrimp. Food Tech. 10, 607. D-20. Boyd, J. W., and H. L. A. Tarr 1955. Inhibition of mold and yeast development in fish products. Food Technol. 9, 411. D-21. Shere, H. 1958. Use of fishery products by households in spring. 1955. The National Food Situation, October, p. 19. Dairy Products 1. Introduction In 1957, dairy products, excluding butter, accounted for approximately 28 per cent of the retail weight of the food consumed in this country; they therefore stood first in importance, on a weight basis. Their nearest competitors were the fruits and vegetables, amounting to 13.7 per cent of the total food retail weight. Dairy items, including butter, cost 16.2 cents of each food dollar, and they con- tributed 14 per cent of the food energy, 25 per cent of the protein, 77 per cent of the calcium, and almost 50 per cent of the riboflavin in the American diet (E-l). The per capita consumption of some of these products is shown in Figure I'M. The use of fresh, whole milk remained remarkably constant from the end of World War I to 1942, at about 260 to 270 pounds per person annually (retail weight). During World War II, con- sumption increased to well above 300 pounds. On the other hand, the use of dairy cream, which was at an almost con- stant level of 11 pounds per person an- nually for 50 years, has steadily declined since 1946 to a 1957 level of 7.4 pounds. Natural buttermilk has shown an almost uninterrupted decline in per capita use from a level of almost 70 pounds at the turn of the century to about 26 pounds in 1957 (E-l). In considering additives for dairy products, public feeling must be taken | 30 25 20 a 'a> c o 1 15 JQ 10 to o z o a. EVAPORATED and CONDENSED MILK .• ICE CREAM CHEESE NONFAT DRY MILK SOLIDS r / 1925 1930 1935 1940 1945 1950 1955 1957 YEAR Fig. E-l. U.S. per capita consumption of dairy products. into account. Because gross adulterations were discovered in the early days of the milk industry, there was established legislation prohibiting the addition of practically anything to milk. The feeling has developed that milk is sacred, and the first of the Ten Commandments of the Dairy Industry is, "Thou shalt not alter." However, milk as it comes from the cow is not necessarily an ideal food, and perhaps if the need exists, it should be altered to meet specific requirements. The stability of dairy products can be improved through the intelligent use of proper additives and this fact could be recognized by the industry (E-2) . 2. Commodity problems a. Milk 1) Fresh milk. Approximately 75 per cent of the total consumed weight of dairy products is in the form of fluid milk and cream. One of the principal problems encountered in fluid milk is off- flavor; feed odors, oxidation, rancidity, exposure to sunlight, and microbial spoilage are only a few of the possible contributory factors. In their review of the literature de- voted to flavors of milk, Strobel and co- workers (E-3) note that most of the studies have been concerned with oxi- dized flavor; this is an indication of the importance of this form of deterioration. The susceptibility of individual lots to oxidized flavor is extremely variable and is markedly influenced by the feed of the cow (E-4). Development of oxidized flavor is catalyzed by light or by con- tamination with copper or iron; it is re- tarded by homogenization and the addi- tion of antioxidants ( E-5. E-6. E-7. E-8 I . [31] The use of the antioxidant ascorbic acid is relatively limited, since its addition is prohibited in most states (E-9). There- fore, the adding of antioxidants and per- haps chelating agents to milk will have to await the repeal of present laws. Rancid off-flavors result from the ac- tion of lipase present in the milk (E-10, E-ll). Many investigators believe that fat in milk is surrounded by a thin film of lipoprotein which protects the fat from lipase. When this protective film is ruptured, the lipase is then able to exert its hydrolytic action. In recent years, the lipase enzymes have been found to be activated by agitation of the warm milk in milker pipelines. Better temperature control and reduction of agitation might remedy the problem; however, it might also be alleviated by a suitable additive that would inactivate the enzyme. Milk drawn from a healthy cow usually contains relatively few microorganisms; contamination usually occurs during sub- sequent handling. Pasteurization elimi- nates pathogenic organisms and those that bring about common deterioration, but spoilage may still be induced by the growth of organisms which survive pasteurization temperatures or enter milk by contamination after pasteurization. Antibiotics have been investigated for their possible value in retarding spoilage (E-12, E-13) , but their use exchanges one problem for another; antibiotics in milk inhibit the growth of the desirable or- ganisms needed in the production of cheese, sour cream, buttermilk, etc. An alternative to antibiotics, hydrogen per- oxide, has been suggested, since it has the advantage over antibiotics that its bac- teriostatic action soon ceases (E-14). It might be possible to supplement pasteuri- zation with additives that would eliminate the organisms which survive it, or addi- tives might be developed which would replace pasteurization altogether. In an attempt to equilibrate milk pro- duction with consumption, milk has been concentrated and frozen. But one diffi- culty encountered was the gelation of casein, considered to be triggered by lac- tose crystallization. A chemical additive might be found which would prevent or delay lactose crystallization (E-15). 2) Evaporated milk. The intensive heat treatment required to achieve sterility has two undesirable consequences: a change in flavor, and in color (due to browning reaction). To retain more of the fresh milk flavor, one processor uses a high-temperature short-time process, but this product gels on storage (E-16). A suitable additive might provide a solu- tion to the problem. It seems clear that milder heat treat- ments would reduce both changes in fresh milk flavor and the browning reaction. The use of lower heat would then entail some method of controlling gelation. Another approach to the problem would be through the use of additives. 3) Dried milk. The consumption of nonfat milk solids is increasing steadily; on the other hand the development of an acceptable whole-milk powder has been rather slow because of the problems of flavor retention, storage stability, and facility of reconstitution. Additives may be the ultimate solution to these prob- lems. Certain surfactants, when added to the milk before spray-drying, have been found to improve the dispersibility of dry whole milk; combinations of Tween 60 and Span 60 were found to be most efficient (E-2). To increase the storage stability of whole-milk powder, the hydrogenation of butterfat has been sug- gested, as has the use of other stabilized fats to overcome oxidative rancidity. The use of antioxidants and an effective oxygen scavenger has also been sug- gested. b. Cheese To retain texture and flavor, cheese must be coated or kept in a very moist atmosphere; under these conditions, however, it is highly susceptible to mold 32 growth. It was estimated in 1952 that about 13 million pounds of cheese could have been saved through the use of an effective fungistatic agent (E-17) such as sorbic acid and propionic acid salts, the use of which is now permitted by FDA. A number of types of cheese acquire their unique characteristics through the development of particular microorgan- isms. Maintaining the growth of certain organisms to the exclusion of others presents a problem, and an agent which would restrict the growth of the unde- sired organisms would be helpful in cheese processing. Such an agent might be developed through studies of the nutri- tional requirements of both desirable and undesirable organisms. The development of a method for ex- tending the shelf life of cottage cheese would be valuable. Organisms respon- sible for a slimy or gelatinous curd which forms, and molds and yeasts which cause changes in flavor, odor, and appearance are a problem in the distribution of this cheese. c. Ice cream In contrast to milk, a variety of addi- tives are used in the production of ice cream. Flavoring agents, stabilizers and emulsifiers are included in most formulas (E-10, E-18), in addition to the basic milk, cream, and sugar. The stabilizers produce and maintain a smooth, creamy texture by absorbing or binding a por- tion of the water in an ice-cream mix and thus preventing it from freezing into large, grainy crystals. Stabilizers classify into two types: Carbohydrates (Irish moss, alginates, locust bean gum) and protein (gelatin and milk protein), and many of them have distinct disadvan- tages. Irish moss produces excessive viscosity and is unsuitable as a sole stabilizing in- gredient because it produces very weak- bodied ice cream. Carboxymethyl cellu- lose produces a "wheyed-off" condition or a mix separation; locust bean and guar gum present the same difficulty, in addition to causing excessive viscosity. Commonly used algin stabilizers are not soluble in the cold mix, and milk proteins are generally not sufficiently concentrated to be useful as a sole stabilizing ingredi- ent. Emulsifiers are added to ice cream to reduce interfacial tension, and to act as foaming agents. Some of their functional advantages are that the ice-cream mix can be whipped faster, the product from the freezer is dryer, and the mix has less tendency to "churn" in the freezer. In addition the product is smoother and has a finer texture. Chemical compounds used as emulsifiers are mono- and di-gly- cerides, polyoxyethylene and sorbitan derivatives, and egg yolk. The mono- and di-glycerides are very effective and are generally accepted by the ice-cream in- dustry. Some question has been raised, however, as to the toxicity of the poly- oxyethylene derivatives. Egg yolk is more expensive to use and has poor keeping quality. Flavor deterioration is not an impor- tant problem in ice cream because of the low storage temperatures and the rela- tively rapid sales turnover of ice cream. The industry is still confronted by the problem of shrinkage from the sides of the container during storage. This shrinkage is due to a loss of the air in- corporated in the mix and the subsequent collapse of the structure; during storage the surface becomes rubber-like, and gives the appearance of not being fresh. [33] LITERATURE CITED E-l. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept. Suppl. July 1958). E-2. McIntire, J. M., W. K. Stone, and M. S. Peterson 1954. Dry milk products. A symposium sponsored by the Quartermaster Food and Container Inst., Chicago, Illinois. E-3. Strorel, D. R., W. G. Bryan, and C. J. Barcock 1953. Flavors of milk, a review of literature. United States Department of Agriculture Pamphlet. E-4. Dunkley, W. L. 1955. Off flavors can be prevented. Hoard's Dairyman, 100, 400, 409 (April 25) E-5. Lucus, E.W., E. W. Bird, and W. S. Rosenrerger 1956. The possibility of copper-induced oxidation of milk in stainless steel-white metal systems. Jour. Dairy Sci. 39, 1487. E-6. Tollenaar, F. D., and D. A. Mossel 1953. The use of chemicals in dairy products. Proc. XIII International Dairy Congress 3, 1831. E-7. Chilson, W. H., W. H. Martin, and C. H. Whitnah 1950. Use of propyl gallate to defer development of oxidized flavor of market milk. Jour. Dairy Sci. 33, 935. E-8. Sievers, F. S. 1954. Antioxidant for dairy products. Massachusetts Agr. Exp. Sta. Bull. 428. E-9. Bauernfeind, J. C. 1953. The use of ascorbic acid in processing foods. Advances in Food Research 4, 359. E-10. Tarassuk, N. P., and E. N. Frankel 1955. Technical notes on the mechanism of activation of lipolysis and the stability of lipase systems of normal milk. Jour. Dairy Sci. 38, 438. Ell. Herrington, B. L. 1956. Control of rancidity in milk. Jour. Dairy Sci. 39, 1613. E-12. Angelotti, R., H. H. Weiser, W. L. Slatter, and I. A. Gould 1955. Effect of antibiotics on microflora of milk. Applied Microbiology, 3, 234. E-13. Anon. 1956. Antibiotics use seen in milk, vegetables, frozen and canned food. Food Field Reporter, 24, (6), 50. E-14. Dahlen, M. A. 1945. Hydrogen peroxide of high purity and its use for sterilization of milk. United States De- partment of Commerce, Office of Technical Service, P. B. 31003. E-15. 1956. Chemical additive sought for frozen milk concentrate. Food Tech. in Australia, 8, 11, 644. E-16. Tarassuk, N. P., and A. F. Tamsma 1956. Control of gelation in evaporated milk. Jour. Agr. Food Chem. 4, 1033. E-17. Smith, D. P. and N. J. Rollin 1954. Sorbic acid as a fungistatic agent for foods. Food Tech. 8, 133. E-18. Redfern, R. B. and W. S. Arruckle 1949. Review of stabilizers and emulsifiers in ice cream production. Southern Dairy Products Jour. 46, (3) 32, 38 and 48. E-19. Weinstein, B. R. 1956. The current status of stabilizers in ice cream. Ice Cream Trade Jour. 32 (Oct.). E-20. Decker, G. C. 1959. Significance of pesticide residues in milk and meat. Jour. Agr. Food Chem. 7, 681. E-21. Patton. S. 1958. Review of organic chemical effects of beat on milk. Jour. Agr. Food Chem. 6, 132. 34] F ] Eggs 1. Introduction Eggs rank next after beef, pork, and milk on the consumer's food budget. It was shown in Table 1 of Part I that 6.3 per cent of the food dollar was spent on eggs between 1947 and 1949, and the general upward trend in the per capita consumption of eggs since 1935 also was indicated. During 1957, 4.5 per cent, or about 3 billion dollars, was spent on eggs (F-l). Although they supplied only 2.6 per cent of our food energy, eggs provided 6.6 per cent of the protein, 8.5 per cent of the iron, and 7.9 per cent of the Vitamin A in U. S. diets. Of the 65 billion eggs available in 1957, approximately 90 per cent were consumed as shell eggs; the remainder were converted to frozen and dried eggs, or were sold to hatcheries (F-2) . 2. Commodity problems a. Shell eggs Eggs are cleaned, graded according to size, and candled for quality. If they are to be kept in cold storage, they gen- erally are coated with mineral oil to maintain quality (F-3, F-4). It was estimated that in 1947 the total loss of eggs between producer and con- sumer was 26 per cent, worth 650 million dollars (F-5). Trussell and co-workers ( F-6 ) found that in British Columbia. 70 per cent of the farms submitted eggs for marketing of which at least 1 per cent were infected with spoilage organisms, as the result of washing. Eggs are usually sterile when laid, but become infected through the pores of the shell by organisms picked up in the nest and during handling. Microbial contami- nation takes place with particular ease when eggs are wet, and considerable re- search has been done on the efficacy of various agents in the wash water in the reduction of microbial spoilage (F-7, F-8) . Thermal stabilization has also been studied quite extensively (F-9). Neither procedure has worked well in practical application, however, and effective methods of reducing microbial spoilage would be of considerable value (F-10). Fumigation with ethylene oxide has been reported to reduce markedly bac- terial spoilage of cold-storage eggs (F-ll), but sterilizing dosages caused the candling grade to drop from A to B. and also produced some liquefaction of the albumen. It has been suggested that even mild fumigation would be economi- cally advantageous because of the con- siderable reduction in spoilage it effects. Further investigations should be carried out on this method of treatment, perhaps with other chemicals. In addition to being subject to micro- bial spoilage, eggs can deteriorate in quality when exposed to warmth, due to the stimulation of embryonic develop- ment in fertilized eggs, and the increase in chemical action in unfertilized eggs. Eggs stored between 29° and 30°F. can be kept acceptably for more than 6 months, although the flavor and cooking quality of cold-storage eggs do undergo change. The possibility of using some agent to maintain the flavor and physical properties of fresh eggs should be in- vestigated. [35] b. Frozen eggs In 1953, 5.7 per cent of the available eggs were processed, and of these 4.7 per cent were frozen. Most frozen eggs are processed during the period of peak pro- duction (March to June) ; and because of their uniformity of composition, are used extensively by the baking industry. A difficulty which arises both with frozen whole eggs and yolks when they are stored frozen, is gelation (F-12), which makes for inconvenience in use. Sugar, salt, or glycerol may be used to retard this thickening, but the addition of salt and sugar to frozen whole eggs or yolks limits their use primarily to the production of mayonnaise, confection- ery, and baked products. The develop- ment of an additive which would prevent gelation and impart little or no flavor would make it possible to extend the use of frozen whole eggs to the home kitchen. Experiments on use of enzymes to prevent gelation have been reported (F-13). A problem met with in frozen egg- white is the occasional presence of iron, which imparts an undesirable pink color. The iron might be removed by use of a suitable chelating agent. c. Egg solids Dried eggs were produced in consider- able quantity during World War II for the armed forces. Their chief drawback was poor storage stability; at the time of packing the quality was excellent. Since then, the storage stability of egg solids has been greatly improved by acid- stabilization prior to drying and, more recently, by the removal of glucose by means of enzymes or yeast (F-14). The production of egg solids was cur- tailed at the end of the war, but is steadily increasing because of their inclusion in the convenience items such as packaged cake mixes, commercial doughnut mixes, etc. Also, the increased storage stability and higher quality of egg solids are mak- ing them more acceptable to bakers and noodle manufacturers. Although a number of improvements have been made in the techniques for preserving egg solids over the past 10 years, some problems are still to be solved. The industry needs an agent which will eliminate the pathogen Salmonella (F-14) from egg solids, and also some means for retaining more of the flavor and leavening power. LITERATURE CITED F-l. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept. Suppl. July 1958) . F-2. Lineweaver, H., and A. A. Klose 1955. Poultry products. In Handbook of Food and Agriculture, ed. by F. C. Blanck. Reinhold Publishing Corporation, New York. F-3. Sherman, H. C. 1948. Eggs dipped in mineral oil for cold storage. In Food Products, 4th ed., The Macmillan Co., New York. F-4. McLaren, B., and W. J. Stadelman 1955. The flavor of your eggs. Poultry Processing and Marketing, 61, (2), 20. F-5.B1 SIKH. M. W. 1948. Losses of poultry products in channels of trade. Abstracts of Poultry Sci. 27, 655. F-6. Trussell, P. C, C. 0. Fi lton, and C. J. Cameron 1955. Bacterial spoilage of shell eggs. II. Incidence of spoilage in eggs from 94 farms. Food Tech. 9, 130. F-7. Cotterill, Q. J., and P. Hartman 1956. Effect of antibiotics on the incidence of spoilage «»f shell eggs. Poultry Sci. 35, 733. [36] F-8. Miller, W. A. 1954. The microbiology of dirty eggs heated in various ways and stored at different tempera- tures and humidities. Poultry Sci. 33, 735. F-9. Funk, E. M., J. Forward, and M. Lorah 1954. Minimizing spoilage of eggs by thermostabilization. Poultry Sci. 33, 532. F-10. Trussell, P. C. 1955. Bacterial spoilage of shell eggs. Food Tech. 9, 126. F-ll. Sawyer, F. M. 1951. Sterilization of eggs with ethylene oxide. M. S. Thesis, University of California, Davis. F-12. Lopez, A., C. R. Fellers, and W. D. Powrie 1954. Some factors affecting gelation of frozen egg yolk. Jour. Milk and Food Tech. 17, 334. F-13. Lopez, A., C. R. Fellers, and W. D. Powrie 1955. Enzymic inhibition of gelation in frozen eggs yolk. Jour. Milk and Food Tech. 18, 77. F-14. Peterson, M. W., and H. E. Groesline 1954. Stability of dehydrated eggs. A symposium sponsored by the Quartermaster Food and Container Inst., Chicago, Illinois. ^N ^ Fats and Oils 1. Introduction The consumption of fats and oils in the United States during 1956 was 10.63 billion pounds, of which approximately 72 per cent went for food use (G-l) . The latter figure refers only to the fat content of products such as butter and margar- ine, and does not include fats in meat, eggs, other dairy products, etc. Further breakdown of this figure for individual products is shown in Table G-l. The trends in the per capita consumption of these commodities from 1925 are shown in Figure G-l. Table G-l. Fats and Oils Used in Products for Consumption During 1956. Commodity Consumption Butter (actual weight) Lard in billion pounds 1.44 1.65 Margarine 1.35 Shortening 1.80 Edible Oils 1.65 2. General problems a. Oxidative rancidity Oxidative deterioration of unsaturated fats is still one of the industry's most im- portant problems. The addition of anti- oxidants to fats, oils, and fat-containing foods does greatly delay the onset of this type of rancidity, but although a number of antioxidants are presently permitted in foods, each has its deficiency (G-3) . For example, butylated hydroxyanisole (BHA) (I) has a noticeable phenolic odor when heated to high temperatures, such as in deep fat frying; butylated hydroxytoluene (BHT) (II) lacks high potency at low concentrations; nordihy- droguaiaretic acid (NDGA) (III) pos- sesses low heat stability, poor oil solu- bility, and is expensive; n-propyl gallate (IV) possesses low heat stability and poor oil solubility in addition to forming a blue-colored complex in the presence of ferric ions. Combinations of some of the above antioxidants, in conjunction with syner- gists, usually retard oxidative rancidity in most commodities. The present market [37] 20 18 16 14 12 O) 0) 2 10 cc to Q Z O 8 Q. BUTTER MARGARINE 1925 193C 1935 1940 1945 1950 YEAR Fig. G-l . U.S. per capita consumption of fats and oils. 1955 1957 OCH 3 OH (CH 3 ) 3 C ^ C(CH 8 ) 8 c Ac CH 3 (ID |38 1 CH 2 -CH-CH-CH 2 -v'^^s I I CH 3 CH : (III) COOC 3 H 7 HO-VbH OH (IV) for food antioxidants is divided among BHA, BHT and propyl gallate at approxi- mately 55, 25, and 20 per cent, respec- tively. A recent publication stated that the total use of antioxidants for food and feed during 1956 was expected to reach 3 million pounds (G-3) , 2 million pounds of which were to be used in poultry feeds. An approximate maximum amount of antioxidants that might be used in human food can be calculated by assuming the addition of 0.01 per cent to the total amount of fats and oils consumed in all commodities. In 1954 approximately 7 billion pounds of fats and oils were con- sumed in the United States. (About 50 per cent of our total fat intake is from those commodities listed under Fats and Oils; the remaining 50 per cent of our fat is from meat, dairy products, and other foods.) From these figures, it can be calculated at the present time that the maximum potential market for use of antioxidants is about 1.4 million pounds per year. The presence of metallic ions such as copper and iron is known to catalyze oxidative rancidity in unsaturated fats and oils. The most obvious solution to this problem would be to prevent metal contamination, but in practice this is not always economically possible. The pres- ent method for reducing the catalytic effect of dissolved metals involves the addition of a metal complexing agent such as citric acid (V), citrate esters (VI), or phosphoric acid. Other com- plexing agents such as ethylenediamine tetracetic acid (VII) may be applicable to foods, and another method for re- moval of contaminating metals might lie in the use of ion exchange resins. As a result of studies on the relation- ship between saturated fat intake and the incidence of atherosclerosis (G-4, G-5. G-6), the food industry is currently vitally concerned about what course to take in the handling of saturated fats. It has been estimated that 30 to 60 million of the 170 million in our population will die of atherosclerosis or hardening of the COOH I COOR ( HO-C i -H 2 -COOH >~H 2 C HO-( ( :h 2 I-COOR .Ho HOOC-CH 2 CH 2 -COOH \ 1 N-CH=-CH 2 -N / \ HOOC-CH, CH 2 -COOH COOH COOR (V '1) (VII) [39] arteries (G-7), and high fat caloric in- take (about 40 per cent of the American diet) is held to be a contributory factor in these diseases. There is some evidence that a readily available source of essential fatty acids may be necessary for the normal meta- bolism of cholesterol (G-8) ; there is controversy, however, over the amount of saturated fat which would be beneficial in the diet. More research is needed before adequate recommendations can be made about whether saturated fat intake should be reduced or essential fats added to our diet as a supplement; if results should show the need for the latter, there will be an increased need for antioxidants to control oxidative rancidity. 3. Commodity problems a. Butter The following procedures are involved in the production of butter from cream: 1. Neutralization: Reduces acidity. Al- kaline salts such as sodium carbonate, magnesium oxide, or calcium carbonate are added to cream. 2. Pasteurization : Enhances the keep- ing quality of butter and eliminates haz- ardous microorganisms. 3. Fermentation : "Ripening" by an acid fermentation to develop desirable flavor. 4. Churning: Coalesces butterfat par- ticles into granules of butter. In 1954 an American Dairy Science Association Committee published a re- port on butter-improvement (G-9), and pointed out that butter deteriorates dur- ing storage as the result of the growth of microorganisms, action of enzymes, and oxidative rancidity. Bacteria and molds are responsible for much of the deterioration in butter, and although the addition of salt retards their growth, an uneven distribution still per- mits spoilage. In "sweet" unsalted butter i limited production), microbial growth is a serious problem. Off-flavors in butter develop with even a slight degree of fat oxidation. Bailey (G-10) considers this deterioration to be "reversion" rather than oxidative rancid- ity. True oxidative rancidity is not a seri- ous problem since butter is stored at low temperatures, and has a relatively low unsaturation. b. Lard The process of obtaining fats from animal tissue is referred to as rendering. The method involves separating the oil by heating the fatty tissue with or without water, or by heating directly with steam. The market for lard was greatly curtailed in the early 1930's by the introduction of more desirable shortenings made by hydrogenating vegetable oils. But, with the recent development of "rearranged lard" [random rearrangement of fatty acids of the triglycerides by the use of sodium methoxide (G-ll) or sodium- potassium alloy (G-12) ] along with the incorporation of mono- and di-glycerides and antioxidant, lard shortenings have become competitive with others. A need has been expressed for better rearrange- ment catalysts, since the use of sodium methoxide results in a fat loss of 3 to 4 per cent due to the formation of methyl esters, in addition to the fat loss caused by saponification when water is added to the reaction mixture to remove the catalyst. c. Edible oils, shortening, and margarine After harvest and prior to processing, some percentage of oil seeds must be held in storage in order to supply the process- ing plant over the entire year. During storage, free fatty acids, which form slowly through the action of the lipase enzyme systems, and oil-soluble break- down products of protein, carbohydrate, and other materials present in the fatty tissue contaminate the oil. Thus, storage conditions must be closely controlled in order to minimize deterioration, and it may be possible to effect additional con- trol by chemical means. Lambow and co- 10 I o II c NH NH (VIII) C ii o workers (G-13) have shown that the ap- plication of maleic hydrazide (VIII), used to defoliate the cotton plant prior to harvest, appears to reduce free fatty acid formation in cottonseed during storage. The use of ammonia or gaseous hydrogen chloride also retards the formation of fatty acids during storage; however, the commercial use of these gases has not been adopted because of their deleterious side-effects (G-14). Crude oil is obtained from oil-bearing seeds either by mechanical expression or solvent extraction. Soybean and cotton- seed meals are high-protein by-products of oil extraction and are primarily used as animal feed. The crude oil is usually refined by neutralizing, bleaching, and deodorizing (G-15). The neutralization step consists of treating the crude oil with an aqueous solution of sodium hydroxide or sodium carbonate to remove not only the free fatty acids, but also the phos- phatides, resins, and mucilaginous mate- rial. An appreciable quantity of neutral oil is lost (as high as 50 per cent of the residue may be neutral oil) during this step of the process. This excessive loss (due to the inclusion of neutral oil) might be reduced by the use of some chemical agent. "Politol," a combination of phosphates and high molecular weight acidic wood products, and other organic compounds containing NH 2 and OH groups (G-16), are reported to reduce refining losses. Color removal from excessively dark or green-colored oils is one of the prob- lems in refining edible oils. Presently. Fuller's earth and activated charcoal are most commonly used to reduce color (G-17). Chemical bleaching agents may be of use (G-15) in reducing the color of excessively dark oils. Although chemi- cal decolorizing agents (oxygen, perox- ides, ozone, dichromates, etc.) are used to treat inedible oils, no suitable decolor- izer has been found for edible oils. Per- acetic acid (IX) should be investigated for possible use in removing excessive color in crude edible oils. o II CH3-C-O-OH (IX) Deodorization consists of the removal of the volatile odor constituents from the heated oil under reduced pressure by a current of steam. Subsequent processing of oil depends upon the use to which the product is to be put. Oils to be used as salad oil or in the preparation of mayonnaise must be "winterized" to remove high-melting tri- glycerides which might precipitate or break the emulsion of mayonnaise on ex- posure to low temperatures. During the winterizing process, the oil must be cooled very slowly in order to obtain crystals of stearin large enough to filter without excessive difficulty. Even so, fil- tration is troublesome because of the rather high viscosity of the cold oil and the soft nature of the stearin crystals. The problem before the industry is to reduce the time required (about 3 days) to winterize the oil. An agent is needed which would induce the formation of large crystals, and thus reduce cooling time or prevent the precipitation of the higher melting triglycerides at low tem- peratures. Cavanaugh (G-18) has re- ported a reduction to 1/13 the usual time by winterizing the oil in the extraction solvent. The reversion (development of beany flavor) of soybean oil has restricted its use to hydrogenated products, such as margarine and shortening (G-19). Upon hydrogenation, a soybean oil becomes [41] stabilized and reversion is no longer a serious problem. A chemical which would prevent, or effectively retard, the devel- opment of the beany flavor, would make it possible to use unhydrogenated soy- bean oil as a salad oil. The antioxidants now permitted in food do not have the impressive stabiliz- ing action in vegetable oils they do in lard, perhaps due to the presence of nat- ural inhibitors. More effective antioxi- dants are therefore needed for use in vegetable oils. In deep-fat frying, oils are held at high temperatures for long periods of time; this prolonged heating causes undesirable odorants and polymers to be formed. A method for retarding or preventing these effects would be highly desirable. Oils for use in shortening and mar- garine must be hardened to a suitable consistency by hydrogenation. Nickel is commonly used as a catalyst for this process, but a selective catalyst should be found which would reduce only par- ticular double bonds of the unsaturated triglycerides, and so prevent the forma- tion of unnatural fatty acids. Other problems to be solved and im- provements to be made in the production of fats and oils are: ( 1 ) A better emulsi- fying agent for mayonnaise is needed to prevent the emulsion from separating even at freezer temperatures; (2) An emulsifying agent for shortening used in preparing cake icing would be valuable; (3) A practical method for the synthesis of triglycerides is being sought. LITERATURE CITED G-l. United States Department of Agriculture 1956. Agricultural Statistics. G-2. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept. Suppl. Oct. 1955). G-3. Anon. 1957. Food and feed antioxidants. Jour. Agr. Food Chem. 4, 667. G-4. May, C. D. 1956. Fats in the diet in relation to arteriosclerosis. Jour. Amer. Med. Assn. 162, 1468. G-5. Robe, K. 1957. Newest dietary whipping boy saturated fats? Food Processing, 18, 21. G-6. Eagle, E., and H. E. Robinson 1956. Fat cholesterol and arteriosclerosis. Jour. Amer. Oil Chemists Soc. 33, 624. G-7. MlLLEVILLE, H. P. 1957. Developments in fat-containing foods. Food Processing, 18 (4), 24. G-8. Anon. 1956. Unsaturated fatty acids and serum cholesterol levels. Nutrition Rev. 14, 327. G-9. Fourt, D. L., C. A. Iverson, C. Jensen, N. E. Fabricius, W. L. Slatter, and G. H. Wilstkr 1954. Report of Committee on Butter, American Dairy Science Association. Jour, of Dairy Sci. 37, 590. G-10. Bailey, A. E. 1945. Industrial oil and fat products. Interscience Publishers, Inc., New York. G-l 1. Slater, L. E. 1953. Lard scores again. Food Fug. 25, 72. G-12. HAWLEY, H. K.and G. W. Holman 1956. Direcl interesterification as a new processing tool for lard. Jour. \mer. Oil Chemists Soc. 33, 29. < , I ... I . \ mboi . M. G., IN. S. Parker, and 1 1. R. ( Iarns 1 956. Effect of maleic hydrazide applied to the cotton plant on the development of free fatty acid in the -•■••ds. Jour. Amer. Oil Chemists Soc. 33, 199. 42 | G-14. Altschul, A. M. 1948. Biological processes of the cottonseed. In Cottonseed and Cottonseed Products, Their Chemistry and Technology, ed. by A. E. Bailey. Interscience Publishers, Inc., New York. G-15. Andersen, A. J. C. 1953. Refining of oils and fats for edible purposes. Academic Press, Incorporated, New York. G-16. Cousins, E. R., R. Prachankadee, and S. Bhodhiprasart 1955. Ethanolamine and other amino and hydroxyl-containing compounds in the refining of rice oil. Jour. Amer. Oil Chemists Soc. 32, 561. G-17. Stillman, R. C. 1955. Bleach and color methods. Jour. Amer. Oil Chemists Soc. 32, 587. G-18. Cavanaugh, G. C. 1956. New integral process for edible oils. Jour. Amer. Oil Chemists Soc. 33, 528. G-19. Daurert, B. F., and P. W. O'Connell 1953. Reversion problems in edible fats. Advances in Food Research 4, 185. G-20. Aaes-Jorgenson, E. 1959. Essential fatty acids as food supplements. Jour. Agr. Food Chem. 7, 246. Fruits and Vegetables 1. Introduction Vitamins, particularly ascorbic acid, are the major nutritional contribution of fruits and vegetables to the diet. In 1957, these foods supplied approximately 92 per cent of the ascorbic acid, 75 per cent of the folic acid, and 50 per cent of the Vitamin A consumed, at a cost of some 24 cents of the food dollar (H-l) . Although the total per capita consump- tion of fruits has not changed over the period 1925 to 1957, there was a signifi- cant shift from the use of fresh to proc- essed items. During this period the con- sumption of fresh vegetables remained constant, while the use of processed items increased (Figures H-l, H-2, H-3 ) . Table H-l shows the level of use of some of these commodities. California, Florida, and Texas are the principal fruit and vegetable production centers, although some are produced in almost every part of the country. Table H-l . Per Capita Consumption of Fruits and Vegetables in the United States (1957) (H-l). Fruit Total fresh fruit apples citrus bananas others peaches grapes Canned fruit Canned juices Dried fruit Frozen fruit and juices Pounds 98.1 19.3 36.7 19.2 42.1 8.5 4.1 22.4 12.2 3.2 9.0 Vegetables Total fresh vegetables tomatoes cabbage carrots lettuce onions celery Canned vegetables . . Frozen vegetables Potatoes Melons Pounds 104.6 12.0 11.3 6.7 20.0 11.2 8.3 43.9 7.5 109.0 25.8 [43] to Q Z o a. ■ ■ 1 170 ■ • ft • ft • ft ■ ft m 160 • ft • ft • ft ■ ft ■ ft : \ VEGETABLES • • .* »• *. 150 f \ * / V* ' " m J I X*- # 1 • • • • • •• • ■ • • 140 !* 1 ll 1 * 1 I ft 1 1*1 1 * 1 I * 1 • ■* I I V - 7 • i ••• j • 1*1 1 ♦ ♦ ••! if •* ft . • • ' if • • *♦•* / • ^ « • *"T 1 a • / ■ • f 1 • • 1 1 * • 1 1 \ • K / I "* J \fruits • • • ♦ • ♦ ♦ « 130 1 < hi " 120 - - 110 - - 100 . *— %.. ■ jt ■ ^L J^ 1925 1930 1935 1940 1945 1950 1955 1957 YEAR Fig. H-l . U.S. per capita consumption of fresh fruits and vegetables. 2. General problems Because of the high cost of picking fruits and vegetables manually, and the difficulty in obtaining labor, considerable effort is being devoted to new develop- ments and improvements in mechanical harvesting, which currently involves shaking the trees and catching the fruit in frames. Fruits that can be picked green, when they are less susceptible to bruising, are adaptable to mechanical harvesting; however, only fruits that can be ripened after picking can be handled in this way. Unfortunately, some fruits cannot easily be picked when green. Ap- plication of maleic hydrazide ill to facil- itate the removal of green olives has had limited success. The development of a chemical which would make it possible to harvest green fruits mechanically with- o ii sv r ID CH NH C II O [44] 25 20 15 Q Z 3 o Ci- 10 1925 1955 1957 Fig. H-2. U.S. per capita consumption of processed fruits. out removing the trees' leaves would be of considerable value. In addition to the usual microbiologi- cal and non-enzymatic spoilage problems which plague all of the food industries, fruit and vegetable producers have the unique problem of postharvest changes. After ripening, sprouting during storage, changes in flavor and texture, and many other physiological changes take place after harvest, and harass growers, packers, and shippers alike. 3. Commodity problems a. Fresh fruits and vegetables General problems. The principal problems in marketing and handling fresh fruits and vegetables result from physiological breakdown and microbial spoilage. It was estimated from the in- spection certificates for fruits and vege- tables unloaded in New York City that 300 million dollars' worth was lost an- nually between 1939 and 1942 (H-2). Some examples of the losses in the vari- ous commodities are summarized in Table H-2. Since these data are almost 20 years old (more recent information is not available), undoubtedly improvements made since then have considerably de- creased these losses. Some specific problems. While ade- quate refrigeration reduces the amount of bacterial spoilage, exposure to low temperatures causes injuries to a number of fresh fruits and vegetables. Thus, to control the growth of microorganisms, a number of chemicals are applied prior to, or during, storage and shipping. These agents may be applied directly to the product, or used to fumigate the box- [45] 50 45 40 35 CO O z o 30 25 20 4 / FROZEN 1925 1930 1935 1940 1945 YEAR 1950 1955 1957 Fig. H-3. U.S. per capita consumption of processed vegetables. cars after they have been filled with the produce. The chemicals currently avail- able do not offer the complete solution to microbial spoilage, since extensive losses still occur. Probably the most strik- ing example of this is in fresh strawber- ries, where it is rare to find a basket mar- keted through commercial channels that does not show some damage. The use of detergents to clean fruits and vegetables, and to lower the bacterial load, is severely limited because of the FDA ruling that no residue of such chem- icals on food items is permissible. Con- sequently, if chemicals are to be used to solve these problems, they must leave non-toxic residues or completely decom- pose before consumption. U> Table H-2. Annual Fresh Food Losses in the United States from 1939 to 1942. Commodity Percentage lost Type of spoilage Apples 20.9 Blue mold and bull's-eye rot, scald, and internal breakdown Grapefruit 12.8 Blue mold and stem end rot Grapes 9.0 Gray mold and Rhizopus rot Oranges 15.3 Blue mold and stem end rot Strawberries 25.0 Gray mold and Rhizopus rot Cabbage 11.6 Bacterial soft rot, watery soft rot, Alternaria leaf spot, black rot, and gray mold Celery 18.6 Watery soft rot, bacterial soft rot, and blackheart (phsyio- logical) Lettuce 24.5 Tipburn (physiological) and bacterial soft rot Onions 20.0 Bacterial soft rot, gray mold, black rot, and smudge Peppers 25.3 Rhizopus rot, bacterial soft rot, gray mold, anthracnose, scald, and freezing Potatoes 15.5 Bacterial soft rot, blackheart (physiological) and freezing Tomatoes 21.6 Bacterial soft rot, Rhizopus rot, Alternaria rot, Phoma rot, late blight, and other decays, and by freezing and chilling Watermelons .... 15.0 Anthracnose, stem end rot, and other decays During the past few years, biphenyl has been used quite extensively on the wrappers of oranges to retard the devel- opment of molds, but objections have been raised to the undesirable odor im- parted to the fruit, and a more satisfac- tory chemical is needed. Another prob- lem encountered in fresh oranges is the redevelopment of the green color while still on the trees; ethylene is not an effec- tive remedy. It is well known that fresh corn and many other produce items lose flavor very rapidly after picking. This has been attributed partly to the loss in sugar through respiration and partly to the conversion of sugar to starch. It would be highly desirable to retard this deteri- oration and to retain more of the fresh quality. In potatoes, too, it would be of value to control the reaction between sugar and starch at some ideal ratio. Sprouting during storage is a problem to all fresh fruit and vegetable consum- ers. Within the last 10 years a number of chemicals have been found that inhibit potato sprouting. The application of ma- leic hydrazide to the foliage approxi- mately 10 weeks before harvest provides adequate control, and a number of chem- icals, including indoleacetic acid (II) and amyl alcohol (III), have been ap- plied directly to tubers for this purpose (H-3). Inhibiting the sprouting of pota- toes and onions appears to be one of the more successful results of ionizing radia- tion. CH 2 COOH (II) CH 3 CH 2 CH 2 CH 2 CH 2 OH (III) [47] Sprouting is only one aspect of the much broader problem of postharvest physiology. Fruits and vegetables gen- erally continue to live and develop after harvest, but this is not always the case. For instance, freestone peaches are picked ripe, which severely limits the period during which they may be shipped or processed. On the other hand, cling- stone peaches may be after-ripened, which represents a great advantage to both the producer and the canner. Meth- ods by which ripening could be speeded or slowed at will would be of wide appli- cation, but their development may well have to await further knowledge about fruit physiology and biochemistry. Very little is known about the extent to which nutrients are lost from fresh fruits and vegetables, or from those which must be picked green for purposes of distant marketing, between harvest and consumption. Research is needed to determine if there is loss, and to what extent. And if it should be shown that appreciable nutrient losses do occur, then methods will be needed for curbing th em. b. Processed fruits and vegetables General problems. A load of fruit or vegetables is frequently held at the processing plant for as long as a day be- fore being processed. During this time, foods such as asparagus, shelled peas, and spinach undergo respiration so rap- idly that the temperature rises sufficiently to cause considerable deterioration. A chemical that could be applied to the crop before or during harvesting, and which could retard respiration, would certainly upgrade the quality of the proc- essed product. To reduce costs, some items are trans- ported in bulk in water between the farm and processing plant, making it possible for the processor to handle items such as peas and peaches with a pump. At pres- ent, chlorine is added to the water to re- tard microbial growth. At effective con- centrations, however, chlorine imparts its odor to the product, and also has an undesirable bleaching effect. A more suit- able agent is needed. Insects, particularly fruit flies and aphids, are a continual hazard to proces- sors. A detergent or some other agent is being sought which, when added to the wash water, would effectively remove these pests, especially from items such as broccoli. Closely related to this is the need for investigation of the effectiveness of water-softening agents and detergents (H-4) in removing pesticides during processing. Canned foods. Sealed containers treated by heat processing are still the most widely used method of extended preservation. The great convenience of canned items lies in their stability at room temperatures, and the highly ac- ceptable canned fruit items have not met competition from the frozen field, as have many of the canned vegetables. One of the most serious problems in canning vegetables is that the heat treatment re- quired by these nonacid foods to obtain sterility leads to excessive changes in both flavor and texture. Many people have become accustomed to some canned vegetables ( peas, for example ) , but, in general, it is desirable to find a way to eliminate the over-cooked taste and soft texture brought about by the usual can- ning procedures. The amount of heat treatment necessary for canned foods might be reduced by some method affect- ing spore germination, as discussed pre- viously (see the section on Canned Meats). At the completion of the heat treat- ment, the cans of food are cooled. Chlo- rine is added to the cooling water to ster- ilize it in the event that any should be drawn into the cans inadvertently. One serious disadvantage of the use of chlo- rine is the corrosive effect it has on the cans, and a cheap noncorrosive bacteri- cide adaptable for use in the cooling water is needed. 48 '| At present, sodium hydroxide is quite an effective fruit peeling aid. To compete with its low cost would be difficult, but an agent that would remove only the skin of the fruit might be competitive by re- ducing peeling losses and permitting greater retention of flavor. Each commodity presents its own char- acteristic problems: among them are the ragged texture of canned freestone peaches, the hard texture and lack of fla- vor of cling peaches, and the darkening of asparagus and also the brine of ripe green olives when the cans have been opened and the contents exposed to air. Frozen fruits and vegetables. One of the principal considerations in the freezing of fruits and vegetables is the effect on texture. Textural changes are brought about by the puncturing of cell walls by ice crystals, dehydration of cells, and destruction of colloidal complexes within the cell. In general, these changes are not objectionable in frozen vegeta- bles, since cooking has the same effect. But the fact that freezing brings about certain textural changes makes it some- what unsatisfactory for some foods, such as strawberries, which become mushy upon thawing, or wholly unsuitable for other foods, such as lettuce and celery, whose appeal lies principally in their crispness. Excessive amounts of liquid may be lost through "weepage"; the develop- ment of a chemical that would permit re- tention of the textural properties of fresh fruit throughout freezing and thawing should make many frozen items much more acceptable. Since frozen fruits are generally not blanched, enzymatic action continues through the period of frozen storage and may lead to several undesirable changes. An example is the darkening of frozen peaches to which no ascorbic acid has been added. Occasionally, insufficiently blanched frozen vegetables develop hay- like flavors through the action of en- zymes. Part of the production line of the Hawaiian Pineapple Company plant in San Jose. (Dole photo.) The consumption of frozen concen- trated orange juice has skyrocketed since its introduction some 10 years ago. The principal difficulty with this product is the settling of the suspended material, brought about by the action of pectic enzymes (H-5) . To retain the stability of orange juice, processors have resorted to heating the concentrate to inactivate these enzymes, but in so doing they have sacrificed a certain amount of flavor. The application of an additive that would nullify the action of pectic enzymes, or inactivate them, would result in an im- proved product by eliminating the need for heat treatment. Another problem encountered in the processing of orange juice concentrate is the development in the concentrator of organisms that lead to off-flavors ("but- termilk flavor") (H-6), as a result of which the concentrating equipment must be shut down and cleaned every few days. Another method of adequately control- ling the microorganisms could lead to more economical processing of the concentrate. Fluctuating temperatures during stor- [49] age of frozen vegetables tend to acceler- ate dehydration, which in turn leads to formation of undesirable color and toughening of texture. Packing frozen vegetables in brine would alleviate this problem, but added refrigeration and transportation costs make this procedure impractical. A method should be devised to prevent the dehydration of these products. The freezing preservation of fruits and vegetables is obviously by no means per- fect. Many items may be successfully pre- served by freezing, but others, as de- scribed above, present problems which may prove insurmountable within the limits set by economic necessity. Pickles. It has recently been estimated that approximately a million dollars' worth of salt stock cucumbers are lost annually because of the action of pec- tinolytic and cellulolytic enzymes (H-7, H-8). These enzymes originate from microorganisms which grow in the wilted cucumber flowers, and at present there is no practical method of removing these flowers. Softening of the cucumber also results from the growth of certain species of Bacillus in the initial brine at low salt concentration. The suggested method for reducing this loss is to drain the initial solution from the cucumbers after 36 to 48 hours of immersion, but it would be valuable to find an agent which could be added to the brine, and which would both stop the action of enzymes causing sof- tening, and prevent the growth of spoil- age organisms. During the production of fermented items, such as pickles, it would be desira- ble to restrict microbial growth to bene- ficial organisms only. To develop a chemical for this purpose, fundamental studies on the nutritional requirements of these organisms will be necessary. Sorbic acid has been reported to reduce spoilage caused by yeast and molds (H-9, H-10), but it may also impart a gray color to the pickles, and at economic concentra- tions it is not consistent in retarding spoilage. Investigation should be made into the practicability of using some of the more selective antibiotics for this purpose. Appearance is an important factor in the sale of pickles, which are usually packed in glass containers. Color fading occurs during pasteurization and con- tinues more slowly during storage. Another problem is the development of "sack bruises" (unsightly brown scratches caused when the cucumbers are handled in sacks) , which begin to appear 8 to 10 months after the injury has oc- curred. During pasteurization pickles also lose flavor, and some method for retaining flavor is needed. In fact, an agent might be developed which would eliminate the need for pasteurization al- together. Another problem in this area is the instability of pickle products to light. The extent to which ordinary artificial light- ing in food stores contributes to the diffi- culty has not been determined and may. in fact, have much more extensive effects on food products than we realize. Colored containers to screen out the harmful radiation may be the answer, while the use of chemical energy absorbers pre- sents another untested approach. Dried fruits and vegetables. This group is represented by two major com- modities, prunes and raisins, which are currently either sun-dried or dried in a dehydrator (with heated air). When preservation of the original color is desirable, as in golden raisins, dried apricots, and peaches, sulfur dioxide is applied prior to drying. The recent an- nual per capita consumption of approxi- mately 4 pounds of dried fruit may seem to be very small. Considering, however, that approximately two-thirds to three- quarters of the fresh fruit weight is lost during drying, this is comparable to the per capita consumption of fresh bananas or apples. During the latter stages of maturation, and during sun drying, it is almost im- 50 possible to avoid fruit flies. (Dro- sophila) . Large infestations during this period lead to quantities of insect frag- ments in the final product, with the re- sult that it cannot then be sold for food use. Since it is impractical, at present, to eliminate the flies from the field, insect contamination may be reduced through the use of repellents. Some work along these lines is being carried out, but no effective repellent has yet been found. Fruit flies are also a serious problem in some fresh fruits and vegetables, and in the canning and wine industries. A difficulty met with in sun-dried fruits is the growth of mold, caused either by unseasonal rains or by farm storage during wet weather. Excessive amounts of mold growth result in lower grading or condemnation. Approximately 40 per cent of the dried raisins are processed during the harvest season, the remainder throughout the year. Raisins stored so that they can be processed over the entire year are liable to infestation by insects and must be fumigated from time to time. Again, an insect repellent would be useful as a pre- ventive measure. Dried fruits could be more widely used in dry cereals and baking mixes if an efficient moisture barrier were to be ap- plied either to the cereals and mixes or to the fruits themselves. The higher moisture content of dried fruits generally leads to loss of crispness, and particularly has an adverse effect on cookie mixes. One objection to applying sulfur dioxide to dried fruits is its undesirable effect on flavor. A suitable agent that has little or no flavor of its own and will per- form all the functions of sulfur dioxide could certainly be utilized by the in- dustry. Recently, such convenience items as de- hydrated potato granules (for preparing mashed potatoes) and powdered pea and tomato soups, and orange juice have become available. The development of these and other new dehydrated items, along with improvements in present products, could reverse the decline in the utilization of dried commodities. How- ever, the reconstitution of dried foods — returning them to their original size, flavor, and texture — is a serious and com- plex problem which faces the industry and which deserves serious attention in terms of research. LITERATURE CITED H-l. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept. Suppl. July 1958) . H-2. United States Department of Agriculture, Agriculture Research Service 1954. Losses in Agriculture. Publication ARS-20-1, June (Mimeographed). H-3. Burton, W. G. 1957. The dormancy and sprouting of potatoes. Food Sci. Abs. 29, 1. H-4. Brekke, J. E., C. C. Nimmo, H. A. Swenson, C. E. Samuels, and J. R. Brock 1953. Studies on removal of thrips from cane berries intended for processing. United States Department of Agriculture, Bureau of Agriculture and Industrial Chemistry, Agr. Res. Admin., AIC-353, Feb. H-5. Guyer, R. B., W. M. Miller, 0. W. Bissett, and M. K. Veldhuis 1956. Stability of frozen concentrated orange juice. Food Tech. 10, 10. H-6. Berry, J. M., L. D. Witter, and J. F. Folinazzo 1956. Growth characteristics of sDoilage organisms, in orange juice concentrate. Food Tech. 10. 553. H-7. United States Department of Agriculture. 1957. How to control pickle softening due to mold growth on withered flower. Agr. Res. 5 (9) . 9. [51] H-8. Demaln, A. L., and H. J. Phaff 1957. Softening of cucumbers during curing. Jour. Agr. Food Chem. 5, 61. H-9. Phillips, G. F., and J. 0. Mundt 1950. Sorbic acid as inhibitor of scum yeast in cucumber fermentation. Food Tech. 4, 291. H-10. Costilow, R. N., W. E. Ferguson, and S. Ray 1955. Sorbic acid as a selective agent in cucumber fermentation. Applied Microbiology, 3 (6). 341. Cereals and Cereal Products 1. Introduction The general trends in the per capita consumption of cereal products between 1925 and 1957 are shown in Figures 1-1 and 1-2. The decline in the consumption of cereal products (with the exception of rice and wheat cereal) is considered by some members of the industry as its most serious problem (1-1). The more recent decline may be attributed to our high land values and the subsequent shift from starchy foods, such as cereal prod- ucts and potatoes, to meat and poultry products. Interestingly enough the de- crease in carbohydrate consumption since 1925 has not been accompanied by an increase in consumption of protein or fats, but rather by an over-all falling off in caloric intake (Figure 1-3). On the basis of major food groups (meat, poultry and fish, dairy products, fats and oils, etc. ) , cereals still supply the largest proportion of food energy, but only by a small margin. In 1957, cereal products supplied 21.0 per cent of the food energy, while fats and oils com- modities supplied 19.9 per cent (1-2) ; a substantial decline from the 1909 to 1913 period, when cereal products contributed 37.2 per cent of the food energy in the American diet. In 1957. cereals also provided a major portion of the thiamine consumed (31.7 percent), and consider- abb- amounts of protein ( 19.5 per cent I. iron (23.7 per cent), and niacin (23.1 per cent ) . 2. General problems a. Storage problems Losses during the storage of cereal grains result from a number of causes. Between 1942 and 1951 the estimated annual loss during farm storage of cereal grains (exclusive of loss due to insects) was approximately 2 billion dollars (1-3). The most serious losses are those due to heat damage; this has been primarily attributed to the heat evolved during the growth of molds in cereal grains whose moisture level is above a critical value. The heat from the respiration of the grain and from metabolic activity of insects, if the grain is infested, can also contribute to heat damage during storage. Investigation of the possible chemical control of molds to prevent the sponta- neous heating of moist grains has been reviewed by Milner and Geddes (1-4). Although a number of chemicals have been tested, no suitable agent has yet been found which would control the growth of molds and preserve the quality of cereal grain. Milner and Geddes pointed out the usefulness of ethylene oxide and methyl bromide against insects; however, its fungistatic proper- [52 1 180 • * \ WHEAT FLOUR 170 • • • • • • 160 • ••-••« • • y : : \ 150 v t * • • ■ 140 • • * * % • s / y PROTEIN A V^ 1925 1930 1935 1940 YEAR 1945 1950 1955 1957 Fig. 1-3. Nutrients available for U.S. consumption per capita per day. tion in grain, however, since most of the losses occur during farm storage, and the use of gamma radiation at the farm level cannot be considered practical there. Losses incurred from insect and rodent infestation (during grain storage) , either by direct consumption or by contamina- tion, are extremely great. Annual losses due to insects alone have been estimated at between 500 and 600 million dollars (1-7, 1-8). Since much of this is caused by contamination during farm storage. [55] there appears to be a need for an insect repellent which will be non-toxic or re- movable during processing, and which will not have any deleterious effect on the final product. Several effective fumigants are pres- ently available, but they may prove to be impractical for farm use because the loose construction of storage bins makes effective fumigation difficult. Even if stor- age bins could be fumigated, reinfesta- tion probably would easily occur. b. Nutritional problems The low level of the essential amino acid lysine (I) in the protein of wheat, rye, and whole oats has been recognized for some time (1-9) . The recent commer- cial production of amino acids has stimu- lated efforts to increase the protein value of some foods by the addition of such compounds. In some localities bread, cookies, and breakfast cereal have al- ready appeared on the market with added lysine (1-10). Not only do inadequate quantities of an essential amino acid lead to nutritional deficiencies, but excessive amounts of a single amino acid can lead to protein imbalance, amino acid toxicity, and amino acid antagonism (I- 11). Although the toxic effects of amino acid imbalance and antagonism are most readily shown in animals fed on low pro- tein diets, these effects can occur even with adequate levels of protein. To obtain the maximum nutritional value, a proper ratio as well as a minimal amount of amino acids are needed ( 1-12 ) . Thus the minimal requirements of an amino acid cannot be met by increasing the intake of a deficient protein. Although no single protein has been determined to be "ideal," human milk protein or egg pro- tein may be considered to have the most desirable composition. NH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH-COOH (0 NH< A very interesting policy change on the supplementation of foods with amino acids was announced recently by the Rodents, an ever-present problem in grain storage, make their presence known by torn sacks and droppings. (Photo by U.S. Public Health Service.) 2PU52 J*;***; ^ia^SS®! y&> - " MP'S V i '** t '&*: f ■■ Food and Nutrition Board, National Research Council of the National Acad- emy of Science. In 1955 the Board stated that "with the present quantity and qual- ity of protein available in the United States there appears to be no need for amino acid supplementation of foods in this country." A recent statement by the Board suggests that now the possibility of using amino acids to supplement dietary deficiencies "is an attractive one" (1-13). The Board recognized the poten- tial value of proper supplementation with amino acids, and the necessity for inten- sive study of this problem. There are still many questions that must be answered before any wide-scale supplementation of our present food could be adopted. If it could be shown that amino acid supplementation would benefit any segment of our population, then this supplementation would be ac- cepted, just as vitamin supplementation has been accepted in bread, flour, milk, etc. Supplementation with amino acids would become a necessity if our popula- tion should ever become largely depend- ent on deficient proteins such as those found in cereals, a situation which might arise during wartime. 3. Commodity problems a. Wheat and wheat flour "Sick wheat" is a deterioration which occurs most often when wheat is stored in large quantities for a considerable length of time (T-4). It can occur below the critical moisture level and with no detectable heating. The primary commer- cial criterion for "sick wheat" is the dis- coloration of the embryo. While a num- ber of reasons have been suggested to account for this breakdown, its exact nature is still unknown. The following is a very brief descrip- tion of the processes involved in the production of flour. Cleaning: The removal of straw, dirt, smutted wheat, other seeds, etc. Tempering or conditioning: The addi- tion of water to whole grain, followed by a short holding period to obtain maxi- mum toughening of the bran for better separation from endosperm. Milling: The gradual separation of endosperm from bran by repeated pas- sage between rollers. After each passage, the material is separated according to particle size (by sifting or purifica- tion) into various streams for further reduction, or into product bins. Detailed descriptions of flour milling may be found in the literature (1-14, 1-15 ) . A constant goal of flour millers is to obtain higher yields of flour without loss in flour quality. Wheat grain consists of approximately 84 per cent endosperm, 14 per cent bran, and 2 per cent germ. Theoretically, one could obtain all the endosperm as flour, but in practice flour yield usually ranges between 70 and 74 per cent. The loss is due to particles of endosperm which adhere to the bran. It is conceivable that some chemicals might be found which, when added to the tempering water, would facilitate better separation of endosperm from bran. The millers have long known that freshly milled flour could be improved both in color and in baking qualities by storage. Addition of certain chemicals called maturing and bleaching agents were found in later years to produce the same effects as storage. Usually both maturing and bleaching agents are classified under one category since, in some cases, a single agent can perform both functions. Although a num- ber of these are allowed under FDA standards of identity, chlorine dioxide ( Dyox) and benzoyl peroxide ( I ) C0 2 OH (I) [57] ( Novadelox) are used exclusively during production of bread flour in the United States (1-16). Potassium bromate is also widely used as maturing agent, but its action occurs almost entirely in the dough stage. For cake flour chlorine gas pro- duces effects not obtainable by any other agent. There are members of the milling in- dustry who are not completely satisfied with the maturing agents presently avail- able, and perhaps more acceptable chemi- cals can be found. Succinic acid (II) is said to be one of the most powerful maturing agents known, but it is too ex- pensive for general use (1-15). Ascorbic acid (III) is another maturing agent which falls in this category, and in some foreign countries this compound is the only maturing agent permitted. If the cost of these chemicals could be substan- tially reduced, their use might be well worth further investigation. Another approach to flour whitening might be the use of an optical bleach similar to those employed in soaps and detergents. Several coumarin (IV) deriv- atives have been reported to be suitable for this purpose in sugar and flour (1-17). These compounds were reported to be nontoxic at the levels used, but this claim might be open to question because of the recently revealed toxicity of cou- marin itself. There has been some question as to the necessity for bleaching flour. At the con- sumer level, the elimination of bleaching of bread flour might hardly be noticed, at least with the present type of flour. Insects continue to be as much of a problem in the storage and transportation of flour as in the storage of whole grain. Fumigation by methyl bromide effec- tively controls insects, but in cases where the product is fumigated a number of times between harvest and consumption, the residual bromide concentration built up by repeated application might reach a dangerous level. Furthermore, repeated application of methyl bromide to flour has been said to impart a "mousey" odor to the bread. Under the provisions of FDA Stand- ards of Identity, a malt preparation may be added by the millers to compensate for any natural deficiency of diastatic or proteolytic enzymes in flour. The dia- static enzymes serve to produce ferment- able sugars, good loaf volume, grain, and texture, as well as good crust color. Pro- teolytic enzymes soften and mellow the stronger wheat flour, and improve con- sistency of the dough. Fungal enzyme preparations from Aspergillus oryzae may not be added to flour by the millers under the Standards of Identity, but may be added during the manufacture of bread and rolls (1-18). The advantage of COOH I CH 2 I CH 2 COOH (M) il II o o-c I H-C — I o = c HO HO- HO-C-H X^O CH 2 -OH (III) (IV) [ 58 ] View inside the Los Angeles plant of Fairfax Bread Company. (Safeway News photo.) -I the fungal enzyme preparation is that the amounts of diastatic and proteolytic enzymes may be varied according to need. With the scarcity of good quality bread flour, there appears to be a need for some chemical which, when added to weak flour, would impart product quality and dough characteristics equivalent to bread made from the strong flour. b. Baked products Bread. Only four basic ingredients are required for manufacturing bread: flour, water, salt, and yeast. Additional ingredients are added to improve bread quality from the standpoint of color, tex- ture, nutritional value, etc. In U.S. typical bread formula consists of 100 parts flour, 64 parts water, 2 parts salt, 6 parts sugar, 6 parts nonfat milk solids, 4 parts shortening, and 0.2 to 0.5 parts dough conditioners. Bread is usually made by one of two procedures: the straight dough method, in which all the ingredients are mixed in one operation, and the sponge and dough method, which is preferred by bakers be- cause of the savings in yeast, improved bread volume and texture, and greater flexibility in baking schedules. The latter method consists of two mixing steps: About 50 to 70 per cent of the flour, all the yeast and yeast food, and sufficient water, are mixed together and allowed to rise; when this sponge is sufficiently developed, the remainder of the ingre- dients are added to form the dough. Sev- eral bakeries have recently installed a continuous breadmaking process (1-19) which has cut the elapsed time from mix- ing to pan for proofing and baking to about 2 minutes. The use of silicone pan glaze has eliminated the need to grease each pan before adding the dough, but since "a small amount of silicone glaze is lost to each loaf of bread, the glaze must be re- applied from time to time. The develop- ment of a more durable glaze would be useful to the baking industry. A rather subtle but important problem in modern bread manufacture is the lack of flavor in the present commercial prod- uct. Because the large commercial bakers operate in such a way that bread is sev- eral hours old by the time it reaches the retailers' shelves, flavor and aroma ap- peal deteriorate appreciably before it reaches the consumer (1-1). Several in- vestigations are under way to determine the aromatic constituents of bread [59] f 1-20 1 ; once described chemically, they could be added to bread to maintain or enhance aroma and flavor. Staling is one of the most serious prob- lems in bread products. Approximately 6 per cent of the bread produced during 1953 was returned as "old bread" ( 1-21 ) . A more descriptive expression of the losses due to staling in 1952 was that it was "an amount adequate to furnish bread for a city the size of Philadelphia for an entire year" ( 1-22 ) . It is generally accepted that crust staling is due to absorption of moisture, and Bechtel and co-workers (1-23) have shown that flavor change is associated with the crust. Crumb staling, however, is a more com- plex process, and because of the various criteria used to measure staling, there is no agreement on the quantitative defini- tion of this phenomenon. Even though a considerable amount of work has been done on the staling of bread, there is still much to be learned. Bechtel (1-21) has reviewed the research on the subject. At the present time it is difficult to con- ceive of an economical control feasible to all the deteriorative factors in bread staling by chemicals. Molding of bread is not an important problem because of its relatively short shelf time and the addition of fungistatic agents, such as propionates and sodium diacetate ("Dykon") (V) ( 1-24) . Mold- ing does become important in brown-and- serve rolls because of the longer shelf life needed for these products, and there is need for fungistatic agents more effective than those now being added. Since brown-and-serve rolls are heated before eating, perhaps a chemical can be found which would break down to nontoxic CHaCOONa CHaCOOH products when heated, as do certain anti- biotics used on poultry. Cream-filled bakery products. Food poisoning as the result of the growth of toxic organisms in cream- filled bakery products continues to be an important public health problem. Accord- ing to Feig (1-25), approximately 35 per cent of the Micrococcus (Staphylococ- cus) outbreaks are caused by bakery products, and in some states the sale of cream-filled products is prohibited dur- ing the summer months. There is appar- ently no satisfactory method for control of these organisms in the usual commer- cial outlets. The development of a non- toxic chemical to control the growth of food-poisoning organisms would be of value. Cakes. Mold spoilage is not as serious a problem in cake merchandising as in bread or rolls. (1-26). Although the pH of cakes is conducive to mold growth, the higher sugar content, lower moisture, and use of icing minimize the extent of molding. However, mold does become a serious problem when cakes are on sale for an extended period of time, particu- larly during the summer months; fruit cakes are among those with an extended merchandising period. Experiments have shown that sorbic acid is four times more effective than propionates for use in cakes, and that it imparts less foreign flavor. Chemical leavening agents. The use of chemicals to leaven baked products was proposed over a century ago by Lie- big, but his suggestion was not adopted until sodium bicarbonate became avail- able at a low cost through the Solvay process. The leavening action is produced by the interaction of a "baking acid" on sodium bicarbonate in the dough or bat- ter. Cream of tartar, monocalcium phos- phate, sodium aluminum sulfate, and sodium acid pyrophosphate are the "bak- ing acids" available in commercial quan- tities. Usually, combinations of two or ()() more of these compounds are used to produce the desired effect, and perhaps a more economical or useful acid could be found or developed. The action of the various "baking acids" in different media is discussed by Brackman ( 1-27 ) . Although a number of developments have been made in the field of leavening agents, there are still many problems to be solved (1-28) . One disadvantage of the use of sodium acid pyrophosphate is that a small residual quantity of this material in cakes or doughnuts imparts a bitter or metallic aftertaste. Also, variability in the action of leavening occurs with differ- ent flours; granulation, age, seasonal variations, and other factors all seem to play an important part in the leaven- ing of baked products. According to Logue (1-29) , an ideal leavening agent would be one which would totally decompose into a gas, leaven the dough, and leave no residue. Acetone dicarboxylic acid ( VI ) has been proposed as one such agent, but its cost has been too high for commercial use. A leavening agent which would be activated by heat rather than by the action of hydrogen ions would be especially help- ful in refrigerated and frozen batters and doughs. One of the requirements for such a chemical would be a decomposition point below 85°C, since the coagulation of the gel structure occurs at approxi- mately this temperature. A leavening agent recently has been reported which is triggered by heat (1-30). It is a stabi- lized form of dicalcium phosphate; the triggering action is still dependent on the release of hydrogen ions. Bicarbonate ions are generally relied upon as a source of CO., HOOC-CH 2 -C-CH 2 COOH (VI) c. Breakfast cereal Stuckey (1-31) has stated that the re- sults of his tests indicate a problem of rancidity in some dry cereal products even though they have extremely low fat content. Such prepared breakfast cereals therefore have relatively short shelf life with respect to the nutty odor and flavor normally associated with these products. Some method of preventing deterioration would be highly desirable. d. Macaroni products The steps involved in the production of macaroni products consist of mixing the semolina and/or flour with water and the optional ingredients listed in the Stand- ards of Identity, kneading to remove any granular structure in the dough, extrud- ing into desired shape, cutting to proper length, and drying. Detailed information concerning the production of these com- modities is in the literature (1-15, 1-32). Color is a very important factor in the quality of macaroni products, especially in the United States. There has been con- siderable work done in developing wheat with desirable coloring for use in maca- roni products. Another approach to the problem could be through the addition of coloring agents during processing. Since carotenes are the primary coloring con- stituent of durum wheat, the synthetic ft- carotene now available might be used, with the advantage of producing uni- formly colored products. Actually, the present Standards of Identity on maca- roni products do not allow the use of coloring matter, but some yellow is im- parted to the enriched macaroni from the added vitamin concentrate. Drying is probably the most critical operation in the production of macaroni products. Checking or cracking is caused by too rapid drying, and is a result of the differential rates of drying between the surface and the center of the macaroni, since the coefficient of expansion with respect to moisture content is large. To obtain a product reasonably free of [01] checking, dehydration is carried out in successive drying and equilibrating (sweating) steps. Lecithin has been pro- posed as a plasticizer for macaroni, and perhaps other plasticizers might be found that could be added to foods. Molding or souring sometimes occurs in the product because of the long periods required for drying. They also occur along the sides of the drier where wet products may touch, and on particles that drop in the driers, and make frequent shut-downs for cleaning necessary. Another problem met with in macaroni products, which might be solved by the addition of a surfactant, is the presence of specks of semolina. Insects also pre- sent a problem at every stage from pro- duction to home storage. e. Rice The storage of rice presents a special problem not encountered in other cereal grains. It is harvested at relatively high moisture content, and thus must be dried artificially to prevent souring before it is put into extended storage. The operation consists of repeated drying alternating with resting periods (approximately 1 day) , since rapid removal of moisture or exposure to high temperatures leads to checking or cracking of the kernels. Sour- ing, although it can be controlled by sufficient lowering of the moisture con- tent below a critical level, is still a prob- lem in rice storage, especially when rains occur during the harvest season. The de- velopment of a chemical which would retard souring even for a short period of time would be of considerable value. Herewith a brief description of the operations involved in milling of white rice (1-15) : Cleaning: The removal of straw, dirt, watergrass seed, etc. Shelling: The removal of hull from the grain. Scouring: The removal of bran layers and germ from hulled rice. Polishing: The removal of inner bran layers. Breakage of the kernels is a difficulty in rice milling, since the milled product is graded according to the content of head rice (unbroken kernels). This is a particularly serious problem with long grain rice, and any method of reducing the amount of breakage would be of value to the rice miller. As has been suggested in connection with wheat, a chemical is needed which would facilitate the re- moval of the bran. During the milling of white rice, a proportion of the vitamins are removed along with the bran and germ, and sev- eral methods have been devised for reten- tion of nutrients. Use of brown rice (hull removed but most of the bran and germ intact) , or undermilling, is one approach. Parboiling the rice is another method; this consists of soaking the rough rice in hot water for several hours to diffuse the water-soluble vitamins from the hull and bran into the endosperm. After drying. ^ COOH N (VII) CH 2 -CH 2 -OH (VIII) [62 the parboiled rice is milled by the same procedure as white rice. A third method is the fortification of white rice by enrob- ing about one-half of 1 per cent of the grains with niacin (VII), thiamine (VIII), and iron (1-33). The law re- quires that white rice for sale in Puerto Rico and South Carolina must be forti- fied. Brown, undermilled, and parboiled rice are all susceptible in varying degrees to oxidative rancidity. The application of a suitable antioxidant might reduce deterioration in these products. /. Corn Some corn meal, still produced by grinding between millstones, contains the germ and retains a rich, oily flavor, but is highly susceptible to oxidation. The addition of an antioxidant should retard spoilage. Another problem in the pro- duction of corn meal is the loss of yellow color, and a solution may lie in the addi- tion of carotene or artificial colors. g. Barley The principal food utilization of barley is in pot or pearl barley. A major prob- lem is its attractiveness to insects. When stored near other grains, barley is con- sistently the first to be infested. Occa- sionally a batch of barley kernels will have a blue color, making it unsuitable for food use. LITERATURE CITED 1-1. Maclay, W. D., and D. K. Mecham 1954. Problems and program on wheat utilization at the Western Utilization Research Branch. Trans. Amer. Assn. Cereal Chemists, 12, 87. 1-2. United States Department of Agriculture, Bureau of Agricultural Economics 1953. Consumption of food in the United States 1909-1952. Agriculture Handbook No. 62 (Sept. Suppl. July 1958) . 1-3. United States Department of Agriculture, Agriculture Research Service 1954. Losses in agriculture. Publication ARS-20-1, June (Mimeographed). 1-4. Milner, M., and W. F. Geddes 1954. Respiration and heating. In Storage of Cereal Grains and Their Products, ed. by J. A. Anderson & A. W. Alcock. Amer. Assn. Cereal Chemists, St. Paul, Minnesota. 1-5. Yen, Y., M. Milner, and H. T. Ward 1956. Treatment of wheat with ionizing radiation. II. Effect on respiration and other indices of storage deterioration. Food. Tech. 10, 411. 1-6. Milner, M., and Y. Yen 1956. Treatment of wheat with ionizing radiation. III. The effect on breadmaking and related properties. Food Tech. 10, 528. 1-7. MlCHELRACHER, A. E. 1954. Insects attacking stored products. Advances in Food Res. 4, 312. 1-8. Haeussler, G. J. 1952. Insects. Yearbook of Agriculture, United States Department of Agriculture, p. 141. 1-9. Hart, E. B. 1952. Abuse of data on the biologic value of proteins. Nutrition Rev. 10, 129. 1-10. Anon. 1956. Pfizer launches lysine additive, see 20 million pound potential. Food Field Reporter. 24 (26), 54. Ml. Harper, A. E. 1956. Amino acid imbalances, toxicities and antagonisms. Nutrition Rev. 14, 225. 1-12. Allison, J. B. 1956. Evaluation of dietary protein. Nutrition Rev. 14, 129. 1-13. Anon. 1956. Nutrition board now considers amino acid addition attractive. Food Field Reporter. 24 (25), 22. [63] 1-14. Scott, J. H. 1951. Flour milling processes. Chapman and Hall, Ltd. London. 1-15. Geddes, W. F. 1951. Technology of cereal grains. In The Chemistry and Technology of Food and Food Products, ed. by M. B. Jacobs. 2nd Ed., Vol. Ill, Interscience Publishers, Inc., New York. 1-16. Harrel, C. G„ and B. M. Dirks 1955. Cereal and cereal products. In Handbook of Food and Agriculture, ed. by F. C. Blanck. Reinhold Publishing Corporation, New York. 1-17. Anon. 1955. Optical bleach for sugars and flours. Food Manuf. 30, 351. 1-18. MacAdams, L. P. 1955. Fungal enzymes in bread production. Food Manuf. 30, 274. 1-19. Anon. 1956. How engineering revolutionizes old art of breadmaking. Food Eng., 28, 74; Flour to fermented dough in two minutes. Food Eng., 28, 98. 1-20. WlSEBLATT, LAZARE. 1956. Bread flavor. Conference on chemistry of natural food flavors, National Academy of Sciences, National Research Council, Advisory Board of Quartermaster, Committee on Foods. Nov. 8-9, Chicago, Illinois. 1-21. Bechtel, W. G. 1955. A review of bread staling research. Trans. Amer. Assn. Cereal Chemists 13, 108. 1-22. Garnatz, G. 1954. What the baking industry needs to know about wheat and flour. Trans. Amer. Assn. Cereal Chemists, 12, 79. 1-23. Bechtel, W. G., D. F. Meisner, and W. B. Bradley 1953. The effect of the crust on the staling of bread. Cereal Chem., 30, 160. 1-24. Glabe, E. F. 1950. A discussion of the characteristics of sodium diacetate as a mold and rope inhibitor. Trans. Amer. Assn. Cereal Chemists, 8, 53. 1-25. Feig, M. 1950. Diarrhea, dysentery, food poisoning, and gastroenteritis. Amer. Jour. Public Health, 40, 1372. 1-26. Melnick, D., H. W. Vahlteich, and A. Hackett 1956. Sorbic acid as a fungistatic for foods. Effectiveness of sorbic acid in protecting cakes. Food Res. 21, 1, 133. 1-27. Brackman, R. A. 1954. Chemical leavening agents. Trans. Amer. Assn. Cereal Chemists 12, 43. 1-28. Pyler, E. J. 1952. Baking science technology. Vol. II. Siebel Publishing Co., Chicago, Illinois. 1-29. Logue, P. 1951. Leavening in prepared mixes. Trans. Amer. Assn. Cereal Chemists, 9, 119. 1-30. Joslin, R. P., and J. V. Ziemba 1955. New leavener triggered by heat. Food Eng. 27, 59. 1-31. Stuckey, B. N. 1955. Increasing shelf life of cereals with phenolic antioxidants. Food Tech. 9, 585. 1-32. LeClerc, J. L. 1933. Macaroni products. Cereal Chem., 10, 383. 1-33. Michus, R. R. 1955. Seals enriching additives on white rice. Food Eng., 27. 91. 1-34. Geddes, W. F. 1959. Recent developments in foods from cereals. Jour. Agr. Food Chem., 7, 605. 1-35. Harris, R. S. 1959. Supplementation of foods with vitamins. Jour. Agr. Food Chem. 7, 88. I 64 1 Wine 1. Introduction In terms of the sum of money spent annually for food in the United States, a small proportion, approximately 0.1 to 0.2 per cent of the food dollar, is spent on wines. The per capita consumption of wines in this country is shown in Figure J-l ; the data for the graph were obtained from a wine periodical (J-l) and from the estimated population according to the U. S. Census Bureau. Only about 5 per cent of the wine consumed in the United States from 1950 through 1956 was im- ported; the rest was supplied by a domestic production which amounted to approximately 130 million gallons per year between 1954 and 1956, and which was centered in California and, to a lesser extent, in northern New York. As a point for comparison, the average yearly wine production during the same period in France and Italy was approximately 1.5 billion gallons per country. The potential market for the use of chemicals in wine production in France and Italy is much lower than the above figures indicate, however, because most of these foreign wines are sent to market in bulk containers and sold directly from the barrels with so rapid a turnover that there is little or no concern for heat, cold, or color stability. In wines produced for export, however, chemicals to facilitate processing or to upgrade quality would be beneficial, and these countries do ex- port in considerable quantities. In brief, wine is produced in the fol- lowing way : The grapes are stemmed and crushed, and in the production of white wines the juice is separated from the skins. Sulfur dioxide is added to retard the growth of undesirable organisms, and fermentation is initiated by the addition of a culture of yeast. For red or pink wines, the skins are removed from the fermenting "must" after sufficient color has been extracted. The fermentation is allowed to go to completion, or, in the case of fortified wine, is stopped by the addition of alcohol when the desired sugar content is reached. The clarifying steps consist of a num- ber of operations involving some or all of the following processes: settling, racking, cooling, heating, fining, and fil- tering to remove any material that might lead to the formation of sediment or tur- bidity. Aging in wood or in bottles de- pends upon the quality and type of wine desired. Much of the wine produced in California leaves the winery 2 months to 1^2 years after the grapes are crushed. More detailed information concerning the production of wines may be found in publications by Amerine and Joslyn (J-2), Cruess (J-3), and Joslyn and Amerine (J-4). 2. General problems There are a number of points in wine production at which the use of chemicals might facilitate an operation or improve quality. Deterioration can occur during the period of shipment from vineyard to winery. Growth of molds, "wild" yeast, and bacteria, in addition to physical breakdown with oxidation and metal pickup, are the major problems. Chemi- cals are needed to retard deterioration, but since most wine grapes are sent to local wineries, this problem is relatively limited. The presence of molds, wild yeast, and bacteria on grapes, necessitates the use of an agent to retard their growth in grape [65] 1.0 0.9 0.8 0.7 to Z O _j —i < 0.6 0.5 0.4 0.3 0.2 0.1 1935 1940 1945 1950 YEAR 1955 1957 Fig. J-l. U.S. per capita consumption of wines. [66 1 "must" under the usual winery condi- tions. A suitable replacement for sulfur dioxide is one of the most serious prob- lems which confronts the wine industry. The principal objections to sulfur dioxide are the undesirable odor and taste it imparts, and the fact that it is responsible for the accumulation of acetaldehyde during fermentation, which may influence color stability in red wines. To illustrate the seriousness of this prob- lem, the French Government has posted a prize, which has remained unclaimed, to stimulate the development of a satis- factory sulfur dioxide substitute in wine production. While it would be difficult to find another single chemical which possesses all the advantageous properties of sulfur dioxide, such as its selectivity in inhibiting the growth of undesirable bacteria and yeast, its property as an antioxidant, and its clarifying, dissolv- ing, and acidifying influences, perhaps a suitable combination of chemicals could be found which would give the de- sired effects. For instance, Verona (J-5) suggested that selection of desirable yeast for fermentation be made on the basis of their differences in nutritional require- ments, and perhaps addition of specific antimetabolites to natural "must" would inhibit the growth of undesirable species of yeast. Approximately 35 per cent of the grapes crushed in California are fer- mented then distilled into brandy. The sulfur dioxide added during fermenta- tion is quite corrosive to the distillation columns, and in addition, is responsible for the accumulation of residual acetalde- hyde during distillation, which presents a removal problem. The question of the toxicity of a replacement for sulfur diox- ide in distilling material is not critical, provided the substitute is nonvolatile or decomposes to nontoxic products upon heating. Current methods for controlling fer- mentation are refrigeration, addition of alcohol or SO,, and removal of yeast by filtration. A valuable agent in the produc- tion of standard quality, stable, sweet table wines would be one that could con- trol the conversion of sugar by stopping or suppressing fermentation. At present, sulfur dioxide, bulk or bottle pasteuriza- tion, or combinations of these are used to stabilize sweet table wines. The possi- bility of the use of sorbic acid (I) in combination with sulfur dioxide is worthy of investigation. Sorbic acid is reported to inhibit yeast growth, while sulfur dioxide in much smaller quantity could control the growth of lactic acid organisms. Antibiotics may be applied to control fermentation, and some work in this field has already been started in Europe. Acti- dione (II) is reported to stabilize wines in concentrations as low as 1 ppm. Actually, the presence of a natural anti- biotic in grape "must" itself has been recognized recently. La Fourcade (J-6) reported the presence of an antibiotic (botryticin) in "must" from grapes on which the mold Botrytis cinerea was al- lowed to grow, and she showed that the addition of botryticin retards the rate of fermentation. The growth of this mold on grapes in certain areas of France. Ger- White table wine fermentation in a closed cask. (Wine Institute photo.) CH,-CH=CH-CH = CH-COOH (I) many, and Hungary increases the con- centration of sugar by facilitating the loss of water. In addition, the mold meta- bolizes a sufficient quantity of acid to produce balanced high-quality, natural, sweet wines, among the most expensive in the world. Extraneous "fermentations," and bac- terial spoilage are widespread in the wine industry. Antibiotics, halogenated fatty acids such as chloracetic acid, and other chemicals have been applied to the prob- lem, but none of these have been ap- proved for use. The subject has been re- viewed recently by Vaughn (J-9). Copper or iron in wines, even in trace amounts of a few parts per million, not only cause the formation of sediment or turbidity, or both, but also cause de- teriorative changes in flavor. However, the exclusive use of stainless steel and other inert materials in the winery is usually economically impractical. At present, the exposure to undesirable metals is kept at a minimum, and exces- sive amounts of metals either are re- moved by the use of "Cufex" [K.Fe. (CN),.J, or stabilized by the addition of citric acid in the case of ferric phosphate cloud. Joslyn and Lukton (J-7) have re- ported rubeanic acid (III) to be a very promising, relatively nontoxic agent for the removal of copper, and suggest fur- ther testing under winery conditions. E. 1). T. A. (ethylenediamine tetracetic acid | (IV) does not bind copper or iron sufficiently to prevent cloud formation in BOine of the wines tested. Another ap- proach might be the use of an ion-ex- change process to remove excessive amounts of trace metals. Although a number of fining agents are used to clarify wines, there is still need for improvement. These agents are utilized in wine production to coagulate and settle suspended materials. A dis- advantage of the use of materials such as bentonite, a special clay, is the amount of wine that is lost due to the formation of a voluminous precipitate which is diffi- cult to filter. Polyvinylpyrrolidone (V) has recently been added to the list of clarifying agents allowed by the Alcohol Tax and Tobacco Division of the Internal Revenue Service, but preliminary tests of this agent for clarifying wines have not given promising results. Much of the tartrate in wines must be removed to prevent formation of unde- sirable sediments in the bottle when ex- posed to low temperatures. At present, these salts are separated by cooling the wine below 20°F. for one week to one month, followed by filtration. Perhaps the use of chemicals to remove or stabilize the tartrates would be economi- cally feasible. Tartaric anhydride (VI) , a complex material made by heating tar- taric acid slightly above its melting point, is reported to prevent precipitation of tartrates in wines (J-8), and the use of ion-exchange resins to remove these salts is becoming common in Italy. Use of the latter in the production of wines in the United States might be worth investi- gating. Heat may be used in any or all of the following steps: Color extraction from f«M SH HN = C SH C-NH HOOC-CH 2 ChL-COOH \ / " N-CH 2 -CH 2 -N / \ HOOC-CH, CH.-COOH (III) (IV) -CH-CH 9 - (V) J O = C-CHOH-CHOH-COOH I O I HOOC-CH-CH-COOH = C-CHOH-CH-COOH etc. (VI) skins, precipitation of proteinaceous material to prevent turbidity, and inacti- vation of yeast at the time of bottling. Except in the production of some sherry wines, heating at any stage of production has a deleterious effect on the quality of the product. Thus, a method for avoiding these heating steps would be of value to the wine industry. A chemical should be found which would facilitate the extrac- tion of color from the skins, or which would promote the transfer of flavoring constituents from grapes to wines. In the case of protein cloud in wine, the use of proteolytic enzymes might be of value in the clarification process. Most sherry wines produced in Cali- fornia are baked at 120° to 140°F. for 2 to 4 months. It might be possible to catalyze the deve'opment of the charac- teristic sherry flavor, and thus reduce the heating time. Oxygen scavengers should be useful in removing oxygen from wines at the time of bottling, and investigation of the practicability of adding an enzyme such as glucose oxidase might be of value. The use of a nitrogen atmosphere during processing and bottling should aid in re- ducing the amount of dissolved oxygen in wines. Other winery problems include the breakdown of pigments in red wines, and the slight browning of white wines in the bottled products; the need for a catalyst to speed the maturation of rough young wines, lacking bouquet, into wines having a balanced bouquet of a fine aged wine: and the constant menace of vinegar flies around the wineries. [69] LITERATURE CITED J-l. Anon. 1946. 1954, 1957. Wines and Vines, 27 (4) 1946; 32 (4) 1954; 38 (4) 1957. J-2. Amerine, M. A., and M. A. Joslyn 1951. Tal)le wines. University of California Press, Berkeley and Los Angeles. J-3. Cruess, W. V. 1947. The principles and practice of wine making. The Avi Publishing Co., Incorporated, New York. J-4. Joslyn, M. A., and M. A. Amerine 1941. Commercial production of dessert wines. California Agr. Exp. Sta. Bull. No. 651, Sept. J-5. Verona, 0. 1956. Recent microbiological advance in oenology. Food Res. 21, 402. J-6. La Fourcade, Suzanne 1954. Contribution a L'etude des activeurs et des inhibiteurs de la fermentation alcoholique de mouts de raisin. Theses: A La Faculte des Sciences de Bordeaux. J-7. Joslyn, M. A. and A. Lukton 1953. Prevention of copper and iron turbidities in wine. Hilgardia 22, 451. J -8. Scazzola, M. F. 1956. Sur un oroduit inhibiteur de la cristallisation du tartre dans les vins. Ann. fals. et fraudes, 49, 159." J-9. Vaughn, R. H. 1955. Bacterial spoilage of wines. Advances in Food Research 6, 67. Beer 1. Introduction The annual production of beer in the United States has remained at approxi- mately 2.8 billion gallons since 1948. The per capita consumption of beer, shown in Figure K-l, indicates that it has not Table K-l . U. S. Per Capita Con- sumption of Beverages (K 10) Consumption (gallons). Commodity 1911-1914 1951-1956 Per cent change Milk 32.14 36.05 12 Coffee 19.31 33.61 74 Beer 20.53 16.55 -19 Tea 15.60 10.40 -33 Soft drinks 0.83 10.27* 1270 Juices 0.03 3.21f 1070 Liquor 1.47 1.13 -23 Wines 0.59 0.89 51 * 1949 to 1952. t 1950 to 1953. regained the popularity it had before prohibition. The changes in consumption of other beverages, included in Table K-l, also illustrate this trend. The steps involved in the production of beer can be briefly described: Malting. Malting involves the germina- tion of barley, and its purpose is to ob- tain maximum enzyme development with minimum loss of food material. This point is reached when growth has de- veloped to approximately three-quarters of the length of the grain, when it is stopped by drying. Mashing. The malt is added to cooked cereal grains, and the action of the malt enzymes converts insoluble carbohy- drates to sugars. Boiling. When the proper amounts of fermentable and unfermentable sugars and dextrin have been produced, the ac- tion of the enzymes is stopped by heating the mash to boiling, which also destroys [70 | 20 15 to Z o -J _J o 10 NATIONAL PROHIBITION 1900 1910 1920 1940 1930 YEAR Fig. K-l. U.S. per capita consumption of beer. 1950 1955 1957 any undesirable organisms. At this tem- perature, the flavor and preservative principle from hops are extracted, the more complex proteins are coagulated, and the mixture is concentrated. Fermenting. The material is then cooled to 60°F., and a quantity of yeast starter is added to initiate fermentation. Clarifying and carbonating. When fermentation is completed, the beer is stored and the yeast is allowed to settle out. Antioxidants, such as sulfites or as- corbic acid, are widely used at this point. Following preliminary storage, beer is finished by filtering, cooling, carbon- ating, and chill-proofing. In chill-proof- ing, a proteolytic enzyme is added which hydrolyzes protein sufficiently to prevent cloud formation at low temperatures. 2. General problems The problems in the beer industry, haze formation, flavor changes, and "gushing" usually arise after packaging. During production, acid-forming bac- teria may grow and give rise to the formation of lactic or acetic acid, but since the material is cooked before fer- mentation, the growth of these organisms does not create a serious problem when proper sanitary precautions are taken. Beer is usually pasteurized after pack- aging to destroy the yeast and spoilage organisms which might cause deteriora- tion of flavor and appearance. However, since pasteurization has a deleterious effect on the flavor and stability of beer (K-l), a number of researchers have in- vestigated the possibility of substituting sterile filtration (K-2), ultraviolet irradi- ation (K-3), or chemical treatment (K- 4). The use of hydrogen peroxide and similar compounds has been investigated, but none is used commerically in the U. S. The production of sterile beer by means other than pasteurization was one of the major topics of discussion at the 1947 European Brewery Convention Congress held in Lucerne, Switzerland. Kringstad (K-l) holds that an ideal an- [71] tiseptic would be one that would (1) destroy the microorganisms or render them incapable of growth within a short time, and (2) then decompose into a harmless substance without affecting the quality of the product. The idea of an antienzymatic com- pound suitable for use in beer production also is attractive. Such an agent could be added to stop all biochemical activity when optimum conditions have been at- tained. Even though precautions are taken to reduce contact with air when beer con- tainers are being filled, in most cases some oxygen is incorporated into the product, causing haze and flavor prob- lems. To counteract the effect of oxygen, ascorbic acid may be used as an anti- oxidant. There is some question as to its appropriateness, since the oxidized as- corbic acid, dehydroascorbic acid (I), or its breakdown products, may act as an oxidizing agent (K-5). Another limita- tion is that ascorbic acid is incapable of removing all the oxygen, and even small quantities of oxygen are damaging. At- tempts to lower the oxygen content by the use of the glucose oxidase enzymes have resulted in off-flavors. The oxidation n O = C-C-C-CH-CH-CH 2 OH llll \ OO OH (I) is further complicated by the catalytic effects of iron or copper in amounts greater than 0.5 ppm. Currently, glucose oxidase is being evaluated as an oxygen scavenging agent in beer. The mechanism of haze formation in beer is still unknown (K-6). Proteins, polyphenols, metals, and oxygen have been mentioned as factors involved in this kind of deterioration, but the pres- ence of oxygen is the most important single factor. Oxidation-haze can result from either proteins or polyphenols. Pro- tein oxidation is suggested to be the oxi- dation of sulfhydryl groups of the amino acid cysteine (II) in the protein, which causes the protein to become insoluble because of the disulfide cross linkages formed. Chill-haze is the formation of a col- loidal precipitate of protein or protein- tannin complex when beer is cooled. The problem can be eliminated by the use of proteolytic enzymes during processing; however, the foaming quality of the beer decreases with increasing protein hy- drolysis. "Collupulin," a chill-proofing agent manufactured by the Wallerstein Laboratories, does not seem to present this difficulty. The sporadic occurrence of "gushing beer" ("wild beer") has been a problem of long-standing to the beer industry (K-7, K-8). Gushing is the rapid release of carbon dioxide when a beer container is first opened, and it is believed to be caused by the presence of minute parti- cles in the liquid upon which the carbon COOH CH-NH 2 I CH 2 I SH HOOC-CH, CH 2 -COOH \ / N-CH2-CH 2 -N / \ HOOC-CH 2 CH,-COOH (ID (III) 72 | dioxide can be released. Traces of metal, products of oxidation, and prolonged low-temperature storage, contribute to the problem, and there is also some evi- dence that it may be protein-induced. It has been found that the addition of a small amount of ethylenediamine tet- racetic acid (III) inhibits "gushing" caused by the more common metal con- taminants (K-8) ; however, its use in commercial practice is not permitted. Gushing is also reported to be reduced or eliminated by the use of ascorbic acid (K-9). The beer industry needs an effective method for removing or inactivating both oxygen and metals in beer, and a substitute for pasteurization. In develop- ing chemicals to alleviate these problems, the instability of beer and its extreme sensitivity to off-flavor must be taken into consideration. LITERATURE CITED K-l. Kringstad, H. 1949. Production of sterile beer by means other than pasteurization. Prog, in Brew. Sci., 1, 171. K-2. Osgood, G. 1949. Sterile filling. European Brewery Convention, 1st Congress, 1, 202. K-3. JUILLERAT, A. 1949. Essai sur la sterilisation des bouteilles a biere au moyen de rayons ultraviolet. European Brewery Convention, 1st Congress, 1, 195. K-4. Jacobsen, H. R., and J. Nestaas 1949. The use of hydrogen peroxide as a beer preservative. European Brewery Convention, 1st Congress, 1, 188. K-5. Urion, E., L. Chapon, S. Chapon, and M. Metche 1956. Fixation of oxygen by beers treated with ascorbic acid. Reprinted in Amer. Brewer, 89, 56. K-6. Barton-Wright, E. C. 1956. The problem of protein haze in bottled beer. Wallerstein Laborat. Comm. 19, 127. K-7. Gray, P. P., and I. Stone 1949. Experiments on wild beer. Wallerstein Laborat. Comm. 12, 311. K-8. Gray, P. P. and I. Stone 1956. Metal induces wildness in beer. Wallerstein Laborat. Comm. 19, 345. K-9. Stone, I., and P. P. Gray 1956. Ascorbate as an antioxidant for beer. Wallerstein Laborat. Comm. 19, 287. K-10. Stanford Research Institute 1958. Chemical economics handbook. Stanford Res. Inst. Menlo Park. California. Coffee and Tea 1. Introduction In the United States, coffee is more important than tea as a beverage, al- though on a world-wide basis, tea is second only to water. In 1956, the United States imported over 55 per cent of the coffee and about 9 per cent of the tea involved in world trade, amounting to 2.81 billion pounds and 100.52 million pounds, respectively. Per capita con- sumption records, as shown in Figure L-l, indicate an over-all increase in the use of coffee and a slight decline in that [73 1 1925 1930 1935 1940 YEAR 1945 1950 1955 1957 Fig. L-l. U.S. per capita consumption of coffee and tea. of tea. This increase in our coffee con- sumption has been attributed to the proximity of the producing areas, ab- sence of import duties, higher standard of living, and sustained purchasing power in the United States (L-l). Most of our coffee comes from Brazil, and Ceylon provides a major part of the i2 ozs. to 100 gals. comminuted product pickle ; % oz. to 100 lbs. meat Dry sausage; 0.5% pork roll Oleomargarine 0.1% Lard and shortening 0.01% Unsmoked dry 0.003% sausage Lard and shortening 0.01% Rendered fats; Sufficient for purpose tomato soup; beans, etc. Export Sufficient for purpose Rendered fat Sufficient for purpose Hogs Imitation sausage; non-specific loaves; soups; stews; etc. Fats; tripe Baked pies, etc. Lard and shortening Unsmoked dry sausage Oleomargarine Chili con carne Beef blood Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose 0.01% 0.01% Sufficient for purpose Sufficient for purpose 0.2% [ 120 1 ADDITIVE PURPOSE PKODUCTS AMOUNT Coloring material, To color casings, Sausage casings; Sufficient for purpose vegetable, and rendered fat, oleomargarine; synthetic marking ink, etc. shortening; branding ink Corn syrup Flavor; cure Cured product; hamburger 2.5% Corn syrup, dried Flavor; cure Cured product; hamburger 2.0% Cyclamate, sodium Sweetener Bacon 0.15% Cyclohexylamine To retard corrosion Boiler water 10 ppm from approved feeder Dextrose Flavor; cure; seasoning Sausage, ham, etc. Sufficient for purpose Diacetyl Flavor Oleomargarine Sufficient for purpose Diatomaceous earth Refining Rendered fats Sufficient for purpose Dry ice ( carbon Cooling Chopping of meat; Sufficient for purpose dioxide-solid) packaging of product Ficin Same use as papain Fullers earth Refining Rendered fats Sufficient for purpose Glycerol Inhibit drying; Seasonings, Sufficient for purpose manufacture of curing mixes mono- & di-glycerides Glycerol lacto- A type of mono- & Shortening Sufficient for purpose palmitate, etc. di-glycerides Gums, vegetable Emulsifying agent; Spice emulsion; egg Sufficient for purpose (tragacanth, karaya, etc.) Hydrogen peroxide binder roll, breading mix Bleach Tripe Sufficient for purpose Hydrolyzed plant Flavor Various Sufficient for purpose protein Isoascorbic acid Accelerate color Cured cuts; cured 1V 2 ozs. to 100 gals. fixing in curing comminuted product pickle; % oz. to 100 lbs. meat Isopropyl citrates To protect flavor Oleomargarine 0.02% Lecithin To retard rancidity development; emulsifier Lard and shortening Sufficient for purpose Lecithin Emulsifier Oleomargarine 0.5% Lignin Loosen scale Steam boilers Sufficient for purpose Lime Denude Tripe Sufficient for purpose Malt syrup Flavor; cure Cured product 2.5% Mono-and Emulsifiers Lard, shortening, Sufficient for di-glycerides oleomargarine purpose, 0.5% in oleomargarine Monoisopropyl citrate To increase effective- Lard, shortening; 0.01% in lard & ness of antioxidants oleomargarine shortening; 0.02% in oleomargarine Monosodium Flavor Various Sufficient for purpose glutamate Morpholine To retard corrosion Boiler water 10 ppm from approved feeder Nickel Catalyst Hydrogenated fats Sufficient for purpose Nitrate of soda Source of nitrite Cured products See sodium or or potassium potassium nitrate Nitrite of soda Fix color Cured products See sodium or or potassium potassium nitrite Nitrogen Exclude oxygen Sealed products Sufficient for purpose Nordhydro- Antioxidant: To Lard and shortening 0.01 % guaiaretic acid retard rancidity development [121] ADDITIVE Octadecylamine Papain Phosphates: diso- dium; sodium hexa- meta-; tripoly-; sodium pyro-; sodium acid pyrophosphate Phosphate, sodium hexameta- Phosphate, trisodium Phosphoric acid Propyl gallate Resin guaiac Silica gel Sodium ascorbate; sodium isoascorbate Sodium carbonate Sodium caseinate Sodium hydroxide Sodium metasilicate Sodium or potassium nitrate Sodium or potassium nitrite Sodium sulfoacetate derivatives of mono- and di-glycerides Sorbitol Starter distillate Stearyl citrate Sugars, approved (sucrose and dextrose) Sulfites with strong alkali Tannic acid Tocopherols PURPOSE PRODUCTS AMOUNT Boiler additive Steam 2.5 ppm in condensed to retard corrosion steam (analysis in steam pipes required) Soften tissue Frozen cuts Sufficient for purpose Decrease amount of Ham, pork, shoulder 5.0% in pumping cooked-out juices picnic; canned pickle; 0.5% in chopped ham canned chopped ham Retard scale Potable water supply 10 ppm from formation in pipes approved feeder Denuder Tripe Sufficient for purpose Synergist : to increase Lard and shortening 0.01% effectiveness of antioxidants Antioxidant: To Lard and shortening 0.01% retard rancidity development Antioxidant: To Lard and shortening 0.1% retard rancidity development Anti-caking agent Curing mixes, etc. 0.5% Accelerate color Cured cuts; cured IVi ozs. to 100 gals. fixing in curing comminuted product pickle; % oz. to 100 Refining; denuding Binder & extender Denuder Denuder Source of nitrite Color fixing Emulsifier Retard drying Flavor To protect flavor Flavoring; curing; seasoning Retard corrosion Refining; loosen scale Antioxidant : to retard rancidity development Fats; tripe Imitation sausage; non-specific loaves ; soups; stews; etc. Tripe Tripe Cured products Cured products Oleomargarine Seasonings Oleomargarine Oleomargarine Sausage, ham, miscellaneous Boiler water Rendered fats; boiler water Lard and shortening lbs. meat; 10% soln. to surface of cured product prior to packaging Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose 7 lbs to 100 gals, pickle ; SV2 ozs. to 100 lbs. meat (dry cure) ; 2% ozs. to 100 lbs. chopped meat 200 ppm (.02%) in product; 2 lbs. to 100 gals, pickle; 1 oz. to 100 lbs. meat (dry cure) ; ^ oz. to 100 lbs. chopped meat 0.5% Sufficient for purpose Sufficient for purpose 0.15% Sufficient for purpose Sufficient for purpose Sufficient for purpose 0.03% [122 1 Synthetic resins, plasticizers, stabilizers, driers, drying oils, colorants and release agents approved for use in rubber or synthetic resin plastics intended for contact with federally inspected meat food product. RESINS Can enamels The classes of resins that have been met with most frequently are: Bisphenol-epichlorhydrin Bisphenol-epichlorhydrin esters Epoxy ester Bisphenol-epichlorhydrin-vinyl Certain modified phenols Certain modified vinyls Oleoresins Alkyl oleoresinous Polyester Alkyl ester The basic types of resins may be listed as fol- lows: Fossil resins, specifically gilsonite, and natural East Indian and Congo resins Bisphenol-formaldehyde Certain substituted phenol formaldehydes Phenol formaldehyde Urea formaldehyde Bisphenol-epichlorhydrin Bisphenol-epichlorhydrin esters Haleic anhydride resin ester Esterified Congo resin Esterified resin Melamine-formaldehyde Polyvinyl chloride and acetate Cellulose acetate butyrate Polystyrene Polyvinyl butyral Polyethylene Petroleum hydrocarbon Films for wrapping foods The acceptable resins for wrapping foods are: Condensate of dimethyl terephthalate and ethylene glycol Resins from high and low viscosity polyvinyl alcohol for fatty foods only Polyvinyl chloride Polyvinyl acetate Polyvinyl chloride-acetate Vinylidine chloride Polystyrene Polyethylene of the high and low pressure type Cellulose acetate Regenerated cellulose Butadiene-scrylonitrile synthetic rubber Methyl and ethyl acrylate Ethyl cellulose Rubber hydrochloride Polyester resin-ethylene terephthalate and ethy- lene isophthalate Butadiene acrylonitrile-styrene copolymer Butadiene-styrene copolymer Terephthalic acid-ethylene glycol copolymer Grease-proofing and wet-strength resins for paper wraps: Polymer of 2-chloro-butadiene Polymer of melamine-formaldehyde Polymer of urea-formaldehyde Polymer of dimethyl-polysiloxane of 350 centistokes viscosity Copolymer of styrene and iso-butylene (for foods of high water content only) PLASTICIZERS Acetyl tributyl citrate Acetyl triethyl citrate Butyl stearate Butyl phthalyl butyl glycollate p-Tertiary butyl phenyl salicylate Dibutyl sebacate Di-iso butyl adipate Di-2-ethylhexyl phthalate (for foods of high water content only) Di-iso-octyl phthalate (for foods of high water content only) Diethyl phthalate 2-Ethylhexyl diphenyl phosphate Ethyl phthalyl ethyl glycollate Glyceryl monooleate Glycerin triacetate Monisopropyl citrate Paraplex G-60 Paraplex G-62 Stearyl citrate Triethyl citrate 3-(2-Xenoxyl) -1,2-epoxypropane STABILIZERS Aluminum monostearate Ammonium citrate Ammonium potassium phosphate Calcium acetate Calcium ethyl acetoacetate acetate Calcium carbonate Calcium glycerophosphate Mono-, di- and tri-calcium phosphate Calcium oleate Calcium ricinoleate Calcium stearate Magnesium glycerophosphate Magnesium stearate Mono-, di- and tri-magnesium phosphate Potassium citrate Disodium hydrogen phosphate Sodium citrate Sodium pyrophosphate Sodium tetrapyrophosphate Tin stearate Inorganic salts of copper-manganese, and zinc, zinc stearate and zinc resinate, are acceptable if the leaching of the metal contributes less than 50 parts per million to the food. [123] DRIERS Cobalt caprylate, linolate, naphthenate, and tallate Iron caprylate, linoleate, naphthenate, and tallate Manganese caprylate, linoleate, naphthenate, and tallate DRYING OILS Chinawood oil Dehydrated castor oil Linseed oil Tall oil COLORANTS (Pigments) Carbon black Oxides of iron Titanium dioxide (National Formulary grade) Ultramarine blue RELEASE AGENTS Acrowax DC Fluid 200 of 60,000 centistokes viscosity Methyl polysiloxane of 350 centistokes viscosity Microcrystalline wax Linoleic acid amide Oleic acid amide Palmitic acid amide Stearic acid amide Polyethylene glycol 400 Polyethylene glycol 1500 Polyethylene glycol 4000 Polytetrafluoroethylene Chemicals approved for use under Federal Poultry Products inspection Act ADDITIVE Acetic acid Amines, filming Agar-Agar Animal & Vegetable Oil Methyl Polysilicone Ascorbic acid Benzoate, sodium: benzoic acid Butylated hydroxyanisole Butylated hydroxytoluene Bicarbonate of soda Caramel Carbon (purified charcoal) Caseinate, sodium Cellulose gum (carboxymethyl cellulose) Chlortetracycline Citric acid Citric acid and sodium citrate Condiments Sodium chloride Coffee extract Coloring material, vegetable and synthetic Corn syrup Corn syrup dried Cyclamate, sodium Cyclohexylamine Dextrose Diacetyl PURPOSE Refining Volatile boiler additive to re- tard corrosion in pipes Stabilizer Shortening To retard foaming Accelerate color fixing in curing To retard flavor reversion Antioxidant : To retard rancidity development Antioxidant: To retard rancidity development To neutralize excess acidity; cleaning vegts. Flavor Refining Binder and extender Extender, stabilizer To retard spoilage Synergist: To increase tiveness of antioxidants Prevents coagulation To develop flavor Flavoring and deboning process To develop flavor Casings and ink only Flavor, cure Flavor, cure Sweetener To retard corrosion Flavor; cure seasoning Flavor effec- AMOUNT Sufficient for purpose See chemical names Sufficient for purpose Sufficient for purpose 10 ppm l x />2 ozs. to 100 gals, pickle; % oz. to 100 lbs. chicken meat 0.1% 0.1% 0.1% Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose 7 parts per million 0.01% 0.2% Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose 2.5% 2.0% 0.15% 10 ppm from approved feeder Sufficient for purpose Sufficient for purpose I I2l| ADDITIVE Diatomaceous earth Dry ice (carbon dioxide solid) Ficin Flavoring (chemical and synthetic) Flour (rice, potato, wheat) Fullers earth Gelatin Glycerol Glycerol lactopalmitate, etc. Gums, vegetable (Tragacanth, karaya, etc.) Hydrolyzed plant protein Isoascorbic acid Lactic acid Lecithin Lignin Malt syrup Mono- and di-glycerides Monoisopropyl citrate Monosodium glutamate Nitrate of soda or potassium Nitrogen Nordihydroguaiaretic acid Papain Phosphates: disodium; sodium hexa-meta-; tripoly-; sodium pyro-; sodium acid pyrophos- phate Phosphate, sodium hexameta- Phosphoric acid Propyl gallate Resin guaiac Silica gel Sodium ascorbate ; sodium isoascorbate Sodium bicarbonate Sodium caseinate Sodium or potassium nitrate PURPOSE Refining Cooling Soften tissue Flavor Thickener Refining Thickener Inhibit drying; manufacture of mono- and di-glycerides A type of mono- and di-glycerides Emulsifying agent; binder Flavor Accelerate color fixing in curing To develop flavor To retard rancidity develop- ment; emulsifier Loosen scale Flavor; cure Emulsifiers To increase effectiveness of antioxidants Flavor Source of nitrite Nitrite of soda or potassium Fix color Exclude oxygen Antioxidant: To retard rancidity development Soften tissue Decrease amount of cooked-out juices Retard scale formation in pipes Synergist: To increase effec- tiveness of antioxidants Antioxidant: To retard rancidity development Antioxidant: To retard rancidity development Anti-caking agent Accelerate color fixing in curing To neutralize excess acidity; cleaning vegts. Binder and extender Source of nitrite AMOUNT Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose Sufficient for purpose IV'2, ozs. to 100 gals, pickle; % oz. to 100 lbs. chicken meat 0.5% Sufficient for purpose Sufficient for purpose 2.5% Sufficient for purpose 0.01% in lard and shortening Sufficient for purpose See sodium or potassium nitrate See sodium or potassium nitrite Sufficient for purpose 0.01% Sufficient for purpose 5.0% in pumping pickle; 0.5% in canned chopped chicken 10 ppm from approved feeder 0.01% 0.01% 0.1% 0.5% l x />2, ozs. to 100 gals, pickle; % oz. to 100 lbs. chicken meat ; 10% soln. to surface of cured product prior to packaging Sufficient for purpose Sufficient for purpose 7 lbs. to 100 gals, pickle; 3V 2 ozs. to 100 lbs. chicken meat (dry cure) ; 2% ozs. to 100 lbs. chopped chicken meat [125] ADDITIVE Sodium or potassium nitrite PURPOSE Color fixing Sodium sulfoacetate deriva- tives of mono- and di-glycerides Sorbitol Starch Stearyl citrate Sugars, approved (sucrose and dextrose) Tannic acid Tapioca Tocopherols Yeast (dry and wet) Emulsifier Retard drying Thickener To protect flavor Flavoring; curing; seasoning Refining; loosen scale Thickener Antioxidant: To retard rancidity development Flavor AMOUNT 200 ppm (0.2%) in product; 2 lbs. to 100 gals, pickle ; 1 oz. to 100 lbs. chicken meat (dry cure) ; *4 oz. to 100 lbs. chopped chicken meat 0.5% Sufficient for purpose Sufficient for purpose 0.15% Sufficient for purpose Sufficient for purpose Sufficient for purpose 0.03% Sufficient for purpose [126] Food coloring agents approved for use under Food, Drug and Cosmetic Act Colors certified for use in food without restriction. FD&C Green No. 1 FD&C Green No. 2 FD&C Green No. 3 FD&C Yellow No. 5 FD&C Yellow No. 6 FD&C Red No. 1 FD&C Red No. 2 FD&C Red No. 3 FD&C Red No. 4 FD&C Blue No. 1 FD&C Blue No. 2 FD&C Violet No. 1 Lakes (FD&C) Colors certified for use in foods with restriction. (1) Batches of Citrus Red No. 2 shall be certified under the regulations in this section for use only for coloring the skins of oranges that are not intended or used for processing (or, if so used, are designated in the trade as "packing-house elimination"), and that meet minimum maturity stand- ards established by or under the laws of the States in which the oranges are grown. (2) Oranges colored with Citrus Red No. 2 shall bear not more than 2.0 parts per million of such color, calculated on the basis of the weight of the whole fruit. (d) A batch of a mixture that contains Citrus Red No. 2 may be certified for use only for coloring the skins of oranges in accordance with the regulations in this section if: (1) Each coal-tar color used as an ingredient in mixing such batch is from a previously certified batch, and such color has not changed in composition in any manner whatever since such previous certification, except by mixing into such batch of mixtures; and (2) Each diluent in such batch of mixture is harmless and suitable for use therein. (e) The label on each package of Citrus Red No. 2 certified in accordance with the regulations in this part shall bear, in addition to other words, statements, and information required by regula- tion, statements prescribing the limitations of use set forth in paragraph (c) (1) and (2) of this section. Co-operative Extension work in Agriculture ord Here Economics, College of Agriculture, University of California, and United States Deportment of Agriculture co-operating. Distributed in furtherance of the Acts of Congress of May 8, and June 30, 1914. George B. Alcorn, Director, California Agricultural extension Strvce. 5m-6,'60(B0400)HR