History of Research on the Nutritional Value, Biochemistry, and Medicinal Uses of Soybeans and Soyfoods - Page 2

by William Shurtleff and Akiko Aoyagi

A Chapter from the Unpublished Manuscript, History of Soybeans and
Soyfoods, 1100 B.C. to the 1980s

 

©Copyright 2004 Soyinfo Center, Lafayette, California

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The First Food, Agriculture, and Nutrition Revolution, 1850-1920 Continued

1919 McCollum, Simmonds, and Parsons , at Johns Hopkins University, published "Supplementary Relationships Between the Proteins of Certain Seeds." They found the best proteins for supporting growth in the rat were those of milk and eggs. The proteins of cereal grains were found to have approximately one-third to one-half the value of the proteins of milk. They reported that soy proteins, while distinctly better than those of the navy bean or the pea, were no better for the support of growth than those of cereal grains. These authors showed (1921a, b) that the rats grew much better (than rtats on what other diet??) when two-thirds of the protein in the diet was supplied by soybeans and one-third was supplied by milk. McCollum, one of America's most respected early nutritionists, discovered vitamin A in 1913 and coined the term "protective foods," to describe foods rich in vitamin A, such as milk, eggs, butter, and leafy green vegetables. He very actively campaigned for the increased consumption of dairy products and eggs in America.

1918 Holmes , an MD in charge of digestion experiments at the USDA Office of Home Economics, investigated the digestibility of soy flour (from hydraulic presscake) in quick breads and biscuits on four young men. The digestibility of the soy protein was estimated at 85.3%, much higher than that of other common legumes. Also that year he studied the digestibility of soy oil. In 1920 he found the digestibility of steamed soybeans to be 79.9%. Referring to vitamins without mentioning the term he said: "Three as yet unidentified food accessories have been designated as fat-soluble A, water-soluble B, and water-soluble C. The soybean is the only known legume with fat-soluble A."

1919 Bowers , at Ohio State University, in the first known PhD dissertation on soybean nutrition, made extensive investigations on the nutritive value, digestibility, mineral content, and off flavors of the soybean, soy flour, and soy bran. He found in two experiments on soy flour that the protein was 91.1% digestible and the carbohydrates were 96.5% digestible by humans. He tried to locate the site of beany flavor in the seed (the first??) and found that it could be easily removed from the bean by steam distillation, but that the beany flavor in the oil could not be removed in this way. In 1919 a 50-page summary of Bower's dissertation was published as a special bulletin by the Food Department of the North Dakota Agricultural Experiment Station.

1919 Johns, Finks, and Paul , of the USDA Bureau of Chemistry, Protein Investigation Laboratory, showed that bread fortified with 25% soy flour produced normal growth in rats, whereas with white bread the growth was one-half to two-thirds normal. Expanded results on soy flour supplementation were published by Johns and Finks in 1921. Kon and Markuze (1931) got similar results on rats using soy-fortified bread.

1920 Von Noorden and Salomon published their influential Handbook of Nutrition in Berlin. In it they recommended the use of soy flour in diabetic diets and cited studies by Fischer on the ease of digestibility of soymilk, which they recommended in many therapeutic diets, as for gastric and duodenal ulcers.

1920-38 Adolph and Co-workers did the first extensive research on soyfoods nutrition in China. Adolph and Kiang (1920) published "The Nutritive Value of Soybean Products" in the National Medical Journal of China . In this first nutritional analysis of Chinese soyfoods, which stimulated a great deal of subsequent research, they focused on tofu and soymilk, giving their nutritional composition. In 1922 and 1926 Adolph, a Professor of Chemistry at Shantung Christian University in Tsinanfu, did additional studies on soyfoods nutrition, and suggested possible connections between some Chinese racial characteristics, their resistance to infection, and their largely vegetarian diet using soy as a major protein source. In 1930 Adolph, now a Professor of Chemistry at Yenching University, published "A 4,000-Year Food Experiment" in Scientific American , in which he praised the Chinese diet and food system and its use of soyfoods?? In 1932 Adolph and Chen studied the utilization of calcium in soy-based diets. They reported that the availability of calcium in both tofu and cow's milk was about the same, and that tofu curded with a calcium salt contained about four times as much calcium as soymilk. In 1932 Adolph and Kao showed that soy flour, tofu, and soymilk were all good sources of iron, effective in promoting hemoglobin regeneration. In 1934 they did a very thorough study of the biological availability of soybean carbohydrates, and showed that about 40% was utilized by rats. In 1938 Kung, Yeh, and Adolph Ref?? found the calcium of soy sprouts to be utilized poorly, only about half as efficiently as the calcium of various green leaves. This body of research, spanning 12 years, stimulated much interest in soyfoods nutrition in China.

1923 Piper and Morse gave the best general review to date of research on soybean nutrition, with an extensive bibliography. They gave the first nutritional analysis of fresh green soybeans. Later nutritional studies on fresh green soybeans were done by Muramatsu (1924), Chung and Ripperton (1929) and Saiki (1931 Ref??).

1923 Mitchell and Villegas , in the first study measuring the Biological Value (BV) of soy protein, used steam cooked soy flour on rats at a 10% protein level. They found the Biological Value to be 64, which was higher than most plant proteins. By whom?? When?? Define BV?? Is it expressed as a percent or not??

1925 Rose and MacLeod at the Department of Nutrition, Columbia University, did the first nitrogen balance study using tofu on an adult human subject. They found that nitrogen equilibrium was maintained on a very low intake and that soy proteins were efficiently utilized by humans. In 1941 Cheng, Li, and Lan did another study on soy protein quality using tofu fed to three adults for three days. The Biological Value of the tofu was found to be 64. Repeat?? By whom??

1926 Averill and King studied the phosphorus content of soybeans and found that the phytin phosphorus content varied from 0.51-0.72%. It was not until the 1960s, however, that it was clearly understood that phytates play a major role in reducing the bioavailability of minerals in diets containing soy proteins.

1926 Shimoda and Co-workers (Ref??) in their Vitamin Content of Japanese Foods , reported that whereas soymilk contains some vitamin B, the tofu made from it contains little.

1926 Ernest Tso , of the Department of Medicine, Peking Union Medical College in China, published (in the American Journal of Physiology ) the first of a number of soymilk feeding studies. This study, done on rats, showed that egg yolk added to soymilk increased the bioavailability of the calcium in the soymilk. In 1928 Tso did the first infant soymilk feeding study and successfully fed an infant 6 weeks of age for 8 months on a soymilk diet. He considered this "the first demonstration that an infant can be successfully fed through the perilous first few months of life on a diet which contains no mammalian milk." The soymilk was fortified consecutively with egg yolk, cod liver oil, and orange juice to increase calcium absorption. Tso considered soymilk's primary defect to be the low content and poor bioavailability of its calcium. In 1928 Tso found that the addition of cod-liver oil and calcium lactate greatly enhanced the retention of both calcium and phosphorus from soymilk. In each test, the weight-growth curves closely followed the averages. Tso noted that cow's milk was 5-10 times as expensive as soymilk in China but that traditionally soymilk, a popular morning beverage, had been "little used as part of the diet for children." In 1929 Tso, comparing the nutritive properties of soymilk and cow's milk, stated that the proteins of soymilk, when fed at a level of 22% of caloric intake, were slightly superior, and at the 14% level of intake were slightly inferior to those of cow's milk fed at the 11% level of caloric intake. Not clear??

The research of Tso and co-workers on soymilk and human nutrition at Peking Union Medical College continued actively through the 1930s. In 1930 Pian reported that the Biological Value of tofu was 65% (is BV a %??) as compared with 85% for cow's milk, 52% for white flour, and 38% for navy beans. Tofu's coefficient of digestibility (define??) was 95%. In 1931 Chang and Tso developed a soluble powdered soymilk and used it to prepare a low-cost infant formula. Growth of infants during an 84-day period surpassed that of infants fed either fresh soymilk or cow's milk, or infants that were breast fed. Also in 1931 Wan did additional rat feeding experiments with both plain and fortified powdered soymilk. On the plain soymilk, growth was below normal and the rats developed rickets. Even the fortified soymilk gave slower growth curves than cow's milk. In 1931 Tso and Chu showed that in infant feeding the nitrogen utilization for cow's milk were much greater than those for soymilk. In 1938 Guy and Yeh fed infants an inexpensive, fortified soymilk but found that the babies had less muscular vigor and weighed less than breast-fed babies. Later that year they fed 49 babies with good results on a similar formula made with roasted soy flour.

It is interesting to note that from the time of Ruhrah in 1909 to that of Tso and co-workers in 1938 most of the early human studies on the nutritive value of soy protein dealt with the growth promoting qualities of soymilk infant formulas.

1927 Rubner (Ref??) in Germany did an important metabolic experiment on one adult on a diet of soy-rye bread (containing 15.9% protein) plus butter and coffee. The incorporated soy protein was extremely well digested (93%), and the minerals were well assimilated. The author concluded that the introduction of soy bread should be recommended "since the enriched bread is excellent in its exterior, taste, and utilization, since it keeps fresh for an extraordinarily long time, and since the added soy protein is much better utilized than the proteins in the usual cereals."

1928 Ducceschi in Italy did studies on the nutritional value of soy bread with six adults for 4-6 days. Breads containing 10% and 20% soy flour were well assimilated, with 83.4 and 80.3% of the protein being absorbed. Ducceschi strongly encouraged the use of 10% soy bread in Italy as a source of high quality, low-cost protein.

1928 Neumann in Germany did complete metabolic experiments on 10 normal adults on the utilization of a diet consisting solely of soy bread containing 20% whole or defatted (solvent extracted) soy flour. The nitrogen utilization of the bread containing whole soy flour was 80.4% versus 79.6% for the defatted flour.

1929 Hill and Stuart of the Harvard Medical School Department of Pediatrics developed an infant formula, resembling that developed earlier by Ruhrah, consisting of soy flour (from defatted presscake), barley flour, olive oil, sodium chloride, and calcium carbonate; it was later marketed as Sobee. With soy flour as the sole source of protein, they fed it as soymilk to 40 infants for 2-8 months. The infants digested it well and thrived on it; some were cured of eczema.

1929 Sumiki in Japan isolated the first saponin (define??) from the soybean. A review of the subject was given by Burrell and Walter in 1935. This was the earliest research on what would later come to be known as "antinutritional factors" in the soybean. (How about Forbes 1909, phytin??)

The 1930s, Overview . This decade was a time of two major crises in the American food system--the Great Depression and the Great Drought. The impact of misapplied farm technology coupled with the drought and the devastated economy broke millions of small farmers, toughing off a mass migration to urban areas. In response to these crises, the federal government intervened in the US food system in a major way for the first time, introducing two food subsidy programs, one for schools and one for families. These later became the Food Lunch Act of the 1950s and the Food Stamp Act of 1964. In 1938 the Federal Food, Drug, and Cosmetic Act was passed (Jerome 1981). During this troubled period research on soy as a source of low-cost high-quality protein for both food and feed continued strong.

Alkaline-Acidic Balance in Foods, Overview . In 1911-12 Li Yu-ying and Grandvoinnet had first mentioned that soyfoods alkalize the blood. In East Asia it is common knowledge which foods are alkalizing and which are acidifying. Alkalizing foods are generally considered curative, capable of combatting acidosis--an abnormal state of reduced alkalinity of the blood and body tissues. In 1931 R. Berg in Germany published a remarkable study, which showed that the body's acid/alkaline balance also had a pronounced effect on protein utilization. An organism with alkaline balance, can make much better use of the protein in the diet, thus lowering the required amount of protein intake. This may be a key factor explaining the wide variation in individual human protein/nitrogen requirements. Since the soybean, itself, helps to alkalize the body, it simultaneously helps lower that organism's protein requirements . . . a built-in conservation mechanism. Starting in the early 1930s the acid/alkaline balance of a food's ash (minerals) became a subject of great interest to American nutritionists in part because of the work of Dr. Henry C. Sherman, the highly respected Professor of Food Chemistry at Columbia University and author of the widely read textbook Chemistry of Nutrition . Sherman found that the proteins of meat, fish, eggs, and grains are acid-producing, while those of soybeans are alkalizing due to the soybeans low sodium and high potassium content; the Na/K ratio of soybeans is about 0.18 and the K/Na ratio is 5.5. During the 1930s many Westerners, including Kellogg (1936) in the US, Kale (1936) in India, and Ferree (1938) in Europe, stressed the importance to good health of this alkalizing quality of the soybean's mineral/ash. (What were their reasons??) Kellogg reported that Becker in Germany found the soybean to be the most alkaline of all plant foods tested. For some reason?? Western nutritionists no longer consider this balance to be important as it is almost never mentioned in textbooks on nutrition.

1932 Mitchell and Smuts first reported that the sulfur-containing amino acids were first limiting in soybeans. The research of Hayward and Hafner (1941) on the growth of chicks, and of Block and Mitchell (1946-47 Ref??) on rat growth indicated that methionine was the soybean's first limiting amino acid. In 1945, however, Bricker and others pointed out that such results should be interpreted with caution since rats had considerably larger methionine requirements than humans.

1932 Rittinger and Dembow , pediatricians in Cleveland, Ohio, fed 50 infants exclusively on a fortified suspended soymilk, from age 4 weeks for 1 year. They found it to be an adequate food for infants, comparing "favorably with the milk of animals from the standpoint of nutritional availability and biologic value." They also gave a good review of soy in feeding experiments to date and published original analyses of the ash and vitamin contents of soymilk. It contained about the same amount of vitamin A as cow's milk and was much richer in vitamin B.

1933 Lucie Yeu wrote her medical dissertation in Paris on soymilk nutrition. She tested soymilk on 100 infants or children with digestive problems and found it was generally well accepted and ensured normal growth. She concluded that it was excellent for people with lactose intolerance (lactose causes them intestinal distress) but could not generally take the place of cow's milk.

1933 McCarrison at the Pasteur Institute in India showed that consumption of various foods, including raw soybeans, peanuts, and cabbage can induce goiter in rats, even with an excess of iodine in the diet. Soybeans, of course, are never eaten raw. Later researchers (Sharpless et al. 1939 Ref?? and Wingus et al. 1941 Ref??) showed that the soybean goitrogenicity is partially inactivated by heat and counteracted by iodine. At normal rates of consumption in a diet that is not seriously deficient in iodine, goitrogenicity is not a problem.

1933 Carey Miller in Hawaii published a nutritional analysis of all the basic Japanese soyfoods.

1934 Jones and Csonka of the USDA showed that the amino acid content of soybeans varies widely with the variety. In 1938 Jones reported that cow's milk was richer in calcium and phosphorus but did not contain as much iron as soymilk, and that cow's milk contained variable amounts of vitamins A and D, which were very low or lacking in soymilk. He noted, "In some way not yet quite understood, cooking is necessary to make the beans more digestible."

1935 J.W. Hayward at the University of Wisconsin wrote his PhD dissertation on The Effect of the Temperature of Oil Extraction Upon the Nutritive Value of the Protein of Soybean Oil Meal . Hayward showed what Osborne and Mendel had shown in 1917, that heating greatly improves the quality of soybean protein. Additional work by Hayward, Steenbock, and Bohnstedt in 1936 demonstrated that cooking soybeans increased the digestibility by about 3% and the Biological Value or protein quality by about 12%. It also showed the importance in animals feeds. These discoveries played the major role in expanding the use of defatted soybean meal in livestock feeding and standardizing the moist heat treatment processing to attain optimum nutritional value. Subsequent research by Hayward and Hafner in 1941 indicated that steaming denatured the soy protein making the amino acids methionine and cystine more available. Hayward, who went to work for Archer Daniels Midland Co. in 1935, went on to become a leading authority on the use of soybean meal in livestock feeding.

1936 Gray , a British medical officer in China, reported in a book about the soybean that the Chinese have much greater freedom from dental and digestive problems than is the case in England. He examined over 100,000 men in the Chinese Labor Corps and noted that it was the exception to find a man who had any bad teeth. Relate to soybeans??

1936 Dr. J.H. Kellogg of Battle Creek, Michigan, reported on the therapeutic properties of acidophilus soymilk and how it had been used to save the lives of several of the Dionne quintuplets after other measures had failed. See also Chapter 23.

1936 Kale reported that soy flour feeding tests were done in two Bombay orphanages. In 1937 the first four nutritional studies on soyfoods in India were published by Aykroyd and Krishnan (on human subjects), Swaminathan (a, b), and Basu, Nath and Mukherjee. These and many subsequent Indian studies are summarized in Chapter 6.3, at India.

1938 Horvath in Delaware wrote "The Nutritional Value of Soybeans," the most comprehensive review of the literature on that subject to date. This invaluable document is especially strong in its treatment of research on soyfoods and human nutrition done in Europe (especially Germany) prior to 1938 and not reported in previous English-language documents. Concerning human feeding tests he noted: "Numerous feeding experiments conducted around the world have established beyond any doubt that for babies soybean proteins are comparable to cow's milk proteins."

1938 Soybean Nutritional Research Council published "The Composition and Nutritive Properties of Soybeans and Soybean Oil Meal", a good review of current views on the subject.

1939 Sherman and Salmon did early vitamin studies on fresh green soybeans and mature dry soybeans.

1940 Helen Mackay in England recommended the use of an infant formula made from equal parts Soyolk soy flour and dried cow's milk. She fed this mixture, called Yolac, to 48 infants for an average of nine months; they were healthy and grew well. She did a comprehensive review of the literature on the use of soymilk for infant feeding.

1941 MacMasters, Woodruff, and Klass , at the University of Illinois reviewed the research to date on soybean carbohydrates. They were unable to identify starch by microscopic examination.

The 1940s, Overview . During World War II meats, fats, sugar, and canned fruits and vegetables were rationed in the US. This directed consumption toward dairy products, eggs, soybeans (especially in the form of soy flour, grits, and fresh green soybeans) and fresh fruits and vegetables. Soyfoods use rose to an all-time high, the major outlets being in Lend-Lease foods for European allies, and in military and institutional foods as meat extenders. Increased usage stimulated increased nutritional research. During the war, nutrition, still a relatively new science in America, became much more a part of the common consciousness with new emphasis on healthful diets and the first vitamin fortification.

During the war, USDA nutritionists developed The Basic Seven Food Groups as an easy-to-grasp synthesis of nutritional knowledge to date. In 1956 they pared the seven food groups down to The Basic Four Food Groups, namely dairy products, meat, fruits and vegetables, and breads and cereals. Thus the use of animal proteins received a strong endorsement from the federal government. Delighted with the support, the National Dairy Council, the educational arm of the dairy lobby, became America's major provider of information on nutritional education to schools, hospitals, and other foodservice organizations.

1941 Cheng, Li, and Tan in China studied the Biological Values on human subjects of tofu, and mixed soybean-pork and soybean-egg proteins. The BV of tofu was 65 and its true digestibility was 97%.

1941 Beeson gave a detailed analysis of 13 minerals found in soybeans and their relation to the soils in which the soybeans were grown.

1942 Cartter and Hopper published a detailed analysis of the chemical composition of the soybean as influenced by variety, environment, and soil fertility. Extensive data were given on calcium, potassium, and phosphorus content.

1943 Burkholder gave an extensive analysis of the vitamins in mature and fresh green (immature) soybeans. In 1945 Burkholder and McVeigh reported on the vitamins in soy sprouts, noting an increase in some vitamins during sprouting. They did not understand why this occurred.

1943 Barnes and Maack gave a lengthy review of the literature on the nutritive value of the soybean. Payne and Stuart of the USDA did a similar review in 1944.

1944 Soybean Trypsin Inhibitors . In this year Ham and Sandstedt and, independently, Bowman, discovered the first protease inhibitor, a trypsin inhibitor, which they found in unheated soybean meal. This substance, which retards the digestion of protein in the body by the pancreatic enzyme trypsin, was extracted from the soybean meal and found to be inactivated by adequate moist heating. This provided a new theory as to why heating improves the soybean's nutritional value. In 1945 and 1946, in a brilliant series of investigations and after many unsuccessful attempts, Kunitz first isolated, crystallized, and identified a trypsin inhibitor, which was subsequently named after him. It was found to be a protein. Ham, Sandstedt, and Mussel (1945 Ref??) showed that soybean trypsin inhibitors (SBTI) retard the growth of chicks. In 1948 Chernick, Lepovsky, and Chaikoff (Ref??) showed that raw soybean meal can cause pancreatic hypertrophy in chicks. It was soon realized that trypsin inhibitors are found in almost all seeds, including peanuts and cereal grains, as well as other beans. The theory that SBTI merely inhibited the trypsin in the digestive tract and therefore interfered with hydrolysis of dietary proteins, resulting in the loss of digestible protein, did not stand the test of time. The real situation proved to be more complex. Between 1948 and 1950 Borchers and Ackerman (Ref??) did experiments which first challenged the SBTI theory and led to new theories. In 1957 Lyman and Lepovsky (Ref??) showed that SBTI causes hypersecretion (of what??) of the pancreas. This and related studies shifted emphasis from the proteinase inhibitory properties of the inhibitor to its mode of action on the pancreas.

1944 Cahill, Schroeder, and Smith used nitrogen balance techniques to study the nutritional value of soyfoods on 16 adults. Average true digestibility and biological value as compared with the protein in whole eggs were as follows: cooked whole soybeans 90.5% and 94.5%; cooked soy flour 94.0% and 91.7%; and soymilk 89.6% and 95.3%. In 1946 Schroeder, Cahill, and Smith investigated utilization of calcium in soyfoods and other calcium sources. They reported the average percent utilization of calcium in evaporated milk to be 29.1%, in calcium sulfate 23.7%, in soymilk 22.6%, and in whole cooked soybeans 10.4%.

1944 Murlin and Co-workers studied the protein quality of isolated soy proteins on human subjects. In 1946 they studied the biological value of soy proteins (especially soy flour) in relation to their essential amino acids (see below), again on adults.

1945 Bricker, Mitchell, and Kinsman studied the protein quality of defatted soy flour on adults and found that it had a biological value of 65 (as compared with 74 for milk proteins). Then in 1947 they showed that the same flour has a biological value of only 49 when fed to adult rats (as compared with 86 for milk and 99 for whole egg proteins). They concluded that the adult rat needs more methionine and cystine than the adult human, and that tests of soy proteins done on rats makes them appear about 25% less nutritious than they actually are for humans. Later research by Cox and others supported this conclusion, yet its significance went largely unnoticed until the late 1970s.

Soy-Fortified Breads, Update . The research pioneered by Johns, Finks and Paul in 1919 and 1921 and by Kon and Markuze in 1931 was greatly expanded during World War II. In 1941 the federal government established the first program to fortify America's standard white bread with vitamins and minerals. The two leading centers of work on fortification with soy flour were the USDA and Cornell University. In 1944 Jones and Divine of the USDA reported that a bread containing 15% soy flour produced better growth in rats than one containing 15% nonfat dry milk. Volz and others at Cornell found in 1945 that the addition of 5% soy flour significantly improves the growth promoting value of white bread which contains 3% whole milk solids. The extensive pioneering work done in this area by McCay at Cornell is described in Chapter 48. Soy-fortified breads became quite popular during?? and after the war.

1949 Harris and Co-workers published a nutritional analysis of all the various Chinese soyfoods, together with their Chinese and English names.

1949 Chang and Murray investigated tofu and soymilk for their protein quality, and their vitamin, mineral, and amino acid content. The studies were done on rats using growth and nitrogen retention methods. The soymilk was 80% and the tofu was 75% as efficient as whole cow's milk. Adding methionine-rich sesame seeds to the tofu raised the efficiency to 94%.

1949 Danielsson (Ref??) first showed that glycinin is not a homogeneous protein; he found two ultracentrifugal components associated with it. Briggs and Mann (1950) found seven more components using electrophoresis (expl??). Naismith (1955) introduced the presently-used nomenclature system for soybean proteins based on sedimentation coefficients (S; expl??) and showed that glycinin consisted of 2S, 7S, 11S, and 15S ultracentrifuge sedimentation fractions.

Essential Amino Acids, Overview . The discovery of a growing number of amino acids during the 1930s led nutritionists to ask which ones were needed by humans and animals, and how much of each. In 1938 W.C. Rose at the University of Illinois introduced the concept of "essential amino acids," demonstrating that 10 amino acids were essential for maximum growth in laboratory rats. Then in 1949 Rose and co-workers (Ref??), in classical pioneering studies based on nitrogen balance experiments in humans, established that humans require a dietary source of eight essential amino acids. Subsequently it was shown that a ninth, histidine, was essential for human infants and, in the long term, for adults as well. Rose published additional key studies in this field in 1957.

The 1950s, Overview . The postwar end of food rationing and the economic boom led to the rise of what was later called the "affluent diet," characterized by a high percentage of meat, dairy products, and fats. Interest in soyfoods in the general diet plummeted, but there was a growth of interest in the use of soyfoods in infant feeding and to combat malnutrition. As grain surpluses and demand increased demand for animal proteins led to a huge expansion of the feedlot system, the use of soybeans as a feed supplement increased proportionally.

1950 Mitchell gave a 42-page review, the best to date, on the "Nutritive Factors in Soybean Products." Mitchell coined the term "antinutriles" for what later came to be known as "antinutritional factors" (explain??) a?? traced knowledge of them. He gave an excellent original table comparing the mineral content of soybeans with that of other foods and feeds, and a detailed report on mineral availability.

1952 Liener and Pallansch first isolated a hemagglutinin from soybeans. This is a thermolabile protein which agglutinates red blood cells. Liener became a leader in the field of soybean antinutritional factors. In 1958 he gave a good review of the effects of heat on soy and other plant proteins.

Soymilk Formulas and Infant Feeding, Update . In 1952 Dean and in 1958 Subrahmanyan and co-workers had shown that soy preparations could play a promising role worldwide in the prevention of malnutrition, especially for children. In 1958 and 1961 DeMaeyer and Vanderborght (sp??) did (the first??) key nitrogen balance studies with infants and children receiving their sole or major source of protein from soy (soy flour). They found a nitrogen balance response equal to 80% that of cow's milk. In 1959 Fomon, a pediatrician at Iowa State University, did important growth and nitrogen balance studies with four infants for 36-72 days using a fortified infant formula in which white (full-fat) soy flour was the sole protein source. No source of calories other than the formula was provided. Fomon concluded "The rate of gain in weight of the infants was normal and retentions of nitrogen (15 metabolic balance studies) were at least as great as those of normal full-term infants of similar ages fed human milk." In 1962 Fomon (Ref??) reported that when approximately 7% of calories are supplied by protein, the proteins of human milk, cow's milk, and soymilk have similar abilities to promote nitrogen retention. The same year many positive findings on soymilk and infant nutrition were published from the world's first soyfoods conference at Peoria, Illinois (USDA NRRC 1962). Additional human growth studies with promising results were subsequently done by Omens et al. (1963; with soy flour), Dutra de Oliveira et al. (1966; with soymilk; the first in Latin America??), Bates et al. (1968; with soy flour and isolate), Andrews and Cook (1969; with soy isolate), and Cowan et al. (1969; with soy isolate). Most found that fortified soymilk had a nutritive value equivalent to that of cow's milk.

1953 Glaser and Johnstone reported that when children from families having allergic diseases were fed soymilk from birth to six months, only 15% of the children developed some form of allergic disease by six years of age, whereas 65% of the sibling controls and 52% of the nonrelated controls fed cow's milk developed similar illnesses. Thus soymilk is relatively non-allergenic.

1953 Sakai in Japan first reported the presence of vitamin B-12 in a fermented soyfood, natto, which contains 0.3 micrograms per 100 grams. In 1955 Takahashi reported finding 0.17 mcg of vitamin B-12 per 100 grams of light-yellow (Shinshu) miso. For the vitamin B-12 content of tempeh, see 1978.

1955 The WHO/FAO/UNICEF Protein Advisory Group (PAG) was established by the Director General of FAO, reflecting an increased worldwide interest in and concern with protein supplies. The first chairman was William J. Darby. In 1961 he was succeeded by Paul Gyorgy^, who had done considerable research on soyfoods. The PAG subsequently published many documents related to the excellence of soy as a source of high-quality, low-cost protein. (De 1971) ??

1957 O'Dell and Savage , in the first studies on the bioavailability of zinc in soybeans, noticed that soybean protein reduces trace mineral bioavailability. In 1960 they showed that phytic acid appears to be the specific compound responsible for the zinc binding properties of soyfoods. In 1960 Forbes and Yoke reported that only 44% of the zinc in soybeans could be utilized by humans.

 

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