History of Green Vegetable Soybeans and Vegetable Type Soybeans
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A Chapter from the Unpublished Manuscript, History of Soybeans and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 Soyfoods Center, Lafayette, California
For updated and greatly expanded free information on this subject,
on our website go to "Historical Bibliographies and Sourcebooks on
Soy," then click on the corresponding subject. A lengthy book will
appear in PDF format. It is searchable using Adobe Acrobat or Adobe
The two simplest ways of using whole soybeans for food are in their fresh green state and in their whole dry state. In either state, the soybeans should be mature (although fresh green soybeans may be eaten shortly after they reach the green mature stage) and must be cooked before they are eaten. Note that, regardless of the color of the dry seed coat, soybeans look emerald green in their fresh green state, and cooking makes their color even greener. Fresh green soybeans, one of the most nutritious of all green vegetables (containing 12.7% protein), can easily be grown in backyard gardens, even at high latitudes where the growing season is too short for dry soybeans. Harvesting the beans in the fresh green state allows you to greatly reduce the cooking time (12 minutes vs 4-6 hours) and also eliminates the problems of threshing and winnowing required for dry beans.
All soybeans can be classified into two large groups: small-seeded field-type soybeans and large-seeded vegetable-type soybeans. Actually this distinction is not very clear cut, for it is generally thought that there is little or no genetic or biochemical difference between the two types, except for seed size, just as there is no fundamental difference between big Watusis and regular human beings. Yet there are qualitative differences. The vegetable types are those which, over the centuries in East Asia, have been selectively bred for large seed size, good flavor, and short cooking time to tenderize. They generally (but not always) have a slightly higher protein content and slightly lower oil content than typical field-type soybeans. The latter are generally bred for their higher yield, higher oil content, and greater resistance to shattering from the pods, which makes them better adapted to mechanical harvesting; little or no regard is typically given to their flavor or small seed size. Actually, smaller seeded soybeans tend to retain their viability better than large-seeded beans, especially in warm, humid climates. This may be one reason that large-seeded vegetable-type soybeans have generally evolved in colder northern climates. Both vegetable and field-type soybeans can be eaten in the fresh green state, however, the vegetable types are usually preferred for their better flavor and texture, and because they are easier to shell. Nevertheless, the great majority (more than 98%) of all soybeans in the world today are the smaller-seeded field (also called commercial) types.
Etymology . In many parts of East Asia and especially in Japan and Korea, virtually all soybeans eaten at the fresh green stage are vegetable-type soybeans. In fact, in Japan there is no way to say "vegetable-type soybeans." The term for "fresh green soybeans" is eda-mame ("branch beans or stalk beans"). The term for large-seeded soybeans, generally grown in northern Japan and prized by all Japanese soyfoods makers for their good flavor, is Nihon daizu ("Japanese soybeans"), whereas the term for just any soybeans, including the typical field types imported from the US or China is daizu ("soybeans," literally "great beans"). Thus we see that fresh green soybeans ( eda-mame ) have a completely different name than whole dry soybeans ( daizu ).
In China, fresh green soybeans are presently called mao dou ("hairy beans," since the green pods are covered with soft short hairs). An earlier name, used from about 200 BC to AD 500, and perhaps long after that, was sheng ta tou ("fresh or raw soybeans"). They have also been called chang wong tau ("blue yellow beans;" Chung and Ripperton 1929). Dry soybeans having a green seed coat, however, are called ch'ing-tou or ch'ing ta-tou ("green soybeans"). In Korea, fresh green soybeans are called poot-kong or sang kong ??
In English, fresh green soybeans have been known by a variety of names: "green soybeans used in the fresh state" (Itano 1905), "the green bean" (Morse 1915), "green beans" (Itano 1918), and "the beans served as a green vegetable" (Jordan 1918). The term "fresh green soybeans" was first used by Bowers in 1919; it was later widely popularized by a Cornell University booklet on soyfoods in 1945. Though now the standard term, it is not perfect since it implies that the beans are eaten fresh (i.e. raw), whereas in fact they must be cooked. Pelton (1920) and many others after him referred to fresh green soybeans as "soybeans used as a green shell bean." During the 1930s and 1940s they were most widely called "green soybeans" (Woodruff 1937, Lager 1942a, Faulkner et al. 1944); the problem with this name was that it did not clearly distinguish between fresh green soybeans and dry soybeans with a light green seed coat. The latter are now typically called "green soybeans." Fresh green soybeans were also called "immature soybeans" (Horvath 1938) or "soybeans in the green immature stage" (Faulkner et al. 1944); this terminology was incorrect in that the soybeans were typically mature but not dry and it also made a poor label, since no one likes to eat a food that is not yet mature. In 1977 R.P. Bates et al. coined the nice but somewhat formal term "green-mature soybeans." In 1981 the Soyfoods Association of North America officially adopted the present term "fresh green soybeans" as the standard.
Vegetable-type soybeans (the term was coined by William Morse in the early 1930s), have also long been called "edible-type soybeans" and "garden-type soybeans." The term "edible" is misleading since all soybeans, both vegetable and field types, are edible and many field types taste quite good. The term "garden-type" is limiting since it implies that they are grown in gardens (as they were widely during World War II) and eaten fresh. In fact, however, most vegetable-type soybeans are now grown on large farms, dried, and sold for making soynuts, soymilk, tofu, and tempeh. It should also be noted that the term "vegetable-type soybeans" is far from ideal, since it implies that the beans are in their fresh vegetable state, whereas they are also often used or sold in their dry state. We will reluctantly follow convention and use the term "vegetable-type" (or "large-seeded vegetable-type") soybeans until someone establishes a better term. How about large-seeded good-tasting (LSGT) soybeans?
To refer to vegetable-type soybeans eaten in their fresh green state, William Morse (1933) coined the term "green vegetable soybeans;" in their dry state they would be called "dry vegetable soybeans."
In French fresh green soybeans were first referred to as graines fraiches , but after the use of the term le soja frais by Li and Grandvoinnet in 1912, that became the standard, as it is now. In German they were first referred to as soja als gemuse ("soy as a vegetable") by Grimme in 1914. Starting in the 1970s they came to be called frische gruene sojabohnen ("fresh green soyabeans").
HISTORY OF FRESH GREEN SOYBEANS IN EAST ASIA
Throughout East Asia soybeans for use as fresh green beans have long been grown along the sides of the narrow footpath-ridges that divide or surround the rice paddy fields and help retain the water, or in rows along the edges of fields of wheat, vegetables, or other crops; the careful farmers made full use of every inch of arable land. At harvest time, today as in ancient times, each plant is uprooted by hand and the dirt is shaken from the roots. After most of the leaves are removed, roughly 15 plants, each with its pods attached to the stalk, are tied in a bundle with a strand of rice straw or hemp, then taken to market where they are sold by the bunch. At homes or in restaurants, the fresh green soybeans are usually boiled (in plenty of plain or salted water) or steamed in their pods, typically for 10-15 minutes without being shelled first. The stems are used as fuel to stoke the cooking or bath fire. The cooked beans are usually served in their pods, either as an hors d'oeuvre or as a vegetable side dish; each diner pops the beans from the pods like peanuts from a shell. This is considered a pleasant past time while dining and saves the cook the time and effort required to shell everyone's beans.
Throughout East Asia vegetable-type soybeans have always been used only to make foods. The preferred use was as fresh green soybeans, but they were also widely used in their dry state to make tofu and other soyfoods. They have never been used as a source of oil, industrial products, or fodder, in part because they sell for more than small-seeded field-type soybeans.
China. The earliest known mention of fresh green soybeans in China was in the Spring and Autumn Annals ( Ch'un ch'iu ) from the second century BC. It stated that "the fresh beans are good for the `yang' or positive principle" (Wu 1848). The Ming I Pieh Lu , a materia medica written by T'ao Hung-ching in AD 452-536 stated that "Fresh green soybeans are useful as a remedy for the following diseases: Dropsical affections, gastric fever, paralysis, difficulty in passing urine, bladder trouble, improper circulation of the blood, catarrh or improper flowing of the fluids of the vital organs, heart, liver, kidneys, stomach and bowels, chills, and poisoning from eating Aconite." The Pen Tsao Kang Mu , a famous materia medica written by Li Shih-chen in 1597, also ascribed to fresh green soybeans a number of medicinal properties.
They were also popular in Manchuria, grown in rows alternating with two rows of corn, kaoliang sorghum, or millet (King 1911).
Following the establishment of the People's Republic in 1949, fresh green soybeans continued to be widely consumed in China. Soybeans for use as a seasonal vegetable were most widely grown on the ridges around rice paddies and consumed mostly by farmers or home gardeners, although some were grown in whole fields for sale at the market. In the Yangtze River Valley, where they continue to be especially popular, they are sown in about the middle of April and harvested around the middle of June (Wang 1982). Farther north, they are harvested in the fall.
In the markets they are generally found in large baskets, in their dark fuzzy pods (though they are occasionally sold shelled). Many Chinese believe that like sweet corn, fresh soybeans are most delicious if eaten as soon as possible after they are picked (Lin 1976). They are not yet canned or otherwise packed commercially.
Typically they are boiled in their pods for 10 minutes, then salted and served in the pods as a side dish or hors d'oeuvre; each diner pops the emerald colored beans into his or her mouth. In China, where some people cook their vegetable with small strips of meat, they may be steamed and sauteed with a little pork or chicken. Or, in north China, they may be boiled or baked over a fire, seasoned with a little soy sauce and sesame oil, and consumed as a snack (H.L. Wang et al. 1977, 1979; Hsu and Hsu 1977).
Japan. Very little is known of the early history of fresh green soybeans or of large-seeded vegetable-type soybeans in Japan. The botanist Nagai (1922 Ref??) reported that the soybeans in northern Japan were larger seeded than those in the south. Nagata (1960; see Chapter 3) seems to demonstrate that large-seeded vegetable-type soybeans differ from other soybeans in that they came to Japan via northern pathway of dissemination from northern China, they grow mostly in northern Japan, and they are a short season crop with a relatively thin seed coat. Hymowitz et al. (1971) have shown that large-seeded beans have a different seed protein electrophoretic banding pattern from small-seeded ones. In ancient Japan, fresh green soybeans were always traditionally enjoyed at the two fall moon viewing festivals, the 15th day of the eighth month and the 13th day of the ninth month (today's mid-September and mid-October). In fact, the evening, just after the soybean harvest, was called Soybean Moon Eve (Motoyama 1958). Early nutritional studies on fresh green soybeans were done by Muramatsu (1924) and Saiki (1931 Ref??). By the 1930s the Japanese were starting their short-season fresh green soybeans hothouses around March 1, then transplanting them in early April, for harvest in late June or July (Dorsett and Morse 1931). Fresh green soybeans have long been one of Japan's most popular summertime vegetables, served chilled and in the pods (after cooking), most often as an hors d'oeuvre--typically with sake or beer in restaurants, mounded on a small bamboo colander--or as a side dish in homes. Usually a little salt is sprinkled on the pods; some of this permeates into the beans, seasoning them lightly and a little also may come off on the lips of the diner as the beans are squeezed from the pod into the lips. Another popular way is to simmer the boiled beans (again in the pods) in a little shoyu and sugar, then serve them in the pods. During the mid-1970s, precooked, shelled fresh green soybeans were introduced in Japan as Hitashi Mame, packed in a lightly salted broth in a sausage-shaped plastic package.
Korea and Other East Asia . Large seeded vegetable-type soybeans are widely found in Korea, and are popular for use as fresh green soybeans. In 1931 Morse noted that they were sold both on the pods and shelled, wrapped in newspaper. They are often served, cooked into rice dishes. Fresh green soybeans are called kedelai rebus in Indonesia; the pods still attached to the stems are immersed in boiling water and cooked for 15-20 minutes until tender. Tied in bundles, they are sold as a snack. In Thailand they are called Tau-rae .
Fresh Green Soybean Leaves. For centuries in China the tender leaves of the soybean plant (called tou-miao ) have been used as a vegetable, especially by poor people or in times of famine, but also at banquets and for daily meals. The most common ways of cooking them are to stir fry with sliced pork or chicken, or to simmer in seasoned broth (Wu 1848). Ochse (1931) noted that they were eaten raw or steamed in Indonesia. Morse (1952 Ref??) reported that they were cured and smoked like tobacco in Manchuria (northeast China) and Korea. In 1981 in Malawi, in Africa, the leaves of one species of soybean were reported to be cooked for use as a side dish.
HISTORY OF FRESH GREEN SOYBEANS IN EUROPE
The earliest known reference to fresh green soybeans in Europe was in 1858, when Lachaume in France recommended their use in what was the West's first soyfoods recipe. "The fresh green seeds are dropped into boiling water. The skin detaches itself from each of the seeds and floats to the surface, whence they are removed. In 30 minutes the cooking is done and furnishes a delicate dish, recalling peas, but containing less sugar." In 1880 the Society's soyfoods expert, Paillieux, noted that shelling the fresh green beans required lots of labor; he did not realize that parboiling makes shelling much easier. In 1885 Harz in Germany reported that fresh green soybeans may contain starch in some varieties, whereas dry soybeans contained none. In 1911 (a,b,c??) Beltzer in France mentioned that one can eat fresh green soybeans like pois verts (green peas). In 1912 Li and Grandvoinnet, in their classic Le Soja , gave a brief discussion of fresh green soybeans (( le soja frais ), noting that, because of their low starch content, they would be a very valuable legume for diabetics, and that they could be canned with good results. In 1914 Mollieux reported that fresh green soybeans were then sold commercially in France. He did an analysis of their composition and food value, probably the world's first. Starting in 1920 Le Goff, a French physician, became a real crusader for the ideas of people growing soybeans in their home gardens and serving them as fresh green soybeans. He noted that they were "as easily cooked as peas and have a flavor somewhat resembling that of chestnuts," and that they were excellent in diabetic diets. Lager (1945) noted that the English, French, and Germans had discovered the value of vegetable-type soybeans by the mid-1920s and had been using them in their diets since that time; unfortunately she did not cite the source of her information. We know of no significant literature from Europe on either fresh green soybeans or vegetable-type soybeans published after Le Goff in 1920. Horvath (1927) mentioned, without citation, that a Mr. Hmelarsh had recommended the cultivation of fresh green soybeans in the northern districts of central Europe. We feel that there is a great potential for using soybeans in this way in Europe in the future.
HISTORY OF FRESH GREEN SOYBEANS IN THE UNITED STATES
Early Developments (1855-1929) . The earliest known reference to and consumption of fresh green soybeans in the US and in the Western world was in 1855, when a man with the initials T.V.P. of Mount Carmel, Ohio, wrote to the Country Gentleman concerning soybeans: "When eaten a few times they are pleasant enough, but have very little flavor--better when mixed with other beans . . . They are inconvenient to use green, being difficult to hull." He was probably not aware of the need to parboil to facilitate hulling.
In 1894 the first large-seeded vegetable-type soybean, Easycook, was introduced to the United States from Shantung Province, China (SPI No. 34702). Morse (1927) said that it was especially suitable for food on account of the ease of cooking; there were about 2,700 seeds per pound, so 100 seeds weighed 16.8 grams. it was not understood until the early 1930s that this was America's first vegetable-type soybean. The second vegetable-type was Hahto, introduced in 1915 from Wakamatsu, on northern Kyushu, in southern Japan. It was even larger seeded (1,250 seeds per pound or 100 seeds weighing 36.3 grams). Morse (1927) wrote of it, "It is commonly known in Japan as `dove killer' and is said to be used boiled in the green stage . . . Especially valuable as a green vegetable when three-fourths to full grown."
The next mention of fresh green soybeans was by the Japanese Oshima in 1905. He commented that in Japan "The black soybeans are used chiefly for cooking with sugar or shoyu; the green variety is also used in this way, either in the fresh state or after being dried." In 1910 Friedenwald and Ruhrah^, discussing the use of the soybean in diabetic diets, cited a recipe developed by the North Carolina Agricultural Experiment Station for serving soybeans with butter, bacon, and seasonings. They suggested that fresh green soybeans could be used in the recipe and that no prior soaking was required.
As World War I got underway, fresh green soybeans attracted new interest. Morse (1915) stated that "The green bean when from three-fourths to full grown has been found to compare favorably with the butter or Lima bean." Piper and Morse (1916), referring to Japanese recipes, noted that soybeans were sometimes "picked green, boiled, and served cold with soy sauce, and sometimes as a salad." In 1917 the world's first canned fresh green soybeans were introduced in America, the first time the fresh beans had been available commercially there (Dacy 1917; Morse 1918a). They were canned by a Michigan cannery and sold well. Dacy felt that they might eventually supplant lima beans in the canning industry since soybeans were produced by modern cost-saving machines, whereas production of limas required extensive hand labor. Jordan (1918) was the first American to stress the importance of parboiling to facilitate hulling. Itano (1918) gave the first US recipe specifically for cooking fresh green soybeans: "Pick them when the beans are three-fourths to full grown. Boil them in salt water. Discard the pods. Serve the beans with butter or milk." The USDA and various schools of nutrition investigated different soybean varieties to find which were the best tasting: Hahto and Easycook were the top choices.
Interest in fresh green soybeans continued after the war, throughout the 1920s. Pelton (1920) wrote a long article about the Hahto soybean as a lima bean substitute, commenting that their flavor reminded him of boiled chestnuts or chicken soup, but that considerable time was required to gather and shell enough beans for one meal. In 1922 Madison Foods in Tennessee became the second company in America to can fresh green soybeans. From 1917 the school had grown these soybeans at the school and served them fresh to the students and staff. In 1919 William Morse had visited Madison and "soy lima beans" (Hahto variety) was served for dinner. Madison also did pioneering work during the 1930s and 1940s. In 1935 Dittes' Food for Life contained early recipes, such as Escalloped Green Soybeans. In 1938 Madison Foods introduced Kreme O'Soys, canned fresh green (or dry) vegetable-type soybeans in a soy sauce broth, and in 1943 they started to market Canned Fresh Green Soybeans.
In 1923 Piper and Morse in The Soybean gave a full page of information on fresh green soybeans and a photograph, plus a nutritional analysis and a recipe calling for the shelled beans to be served with butter, salt, and pepper, or in a white sauce. The authors felt that, "As they are much cheaper than lima beans and equal in quality, this promises to become an important industry. At the American Soybean Association meeting in Wisconsin in 1923 a local canner-grower and a chemist demonstrated how to harvest and can fresh green soybeans. The beans were still in the markets in larger cities by 1928, according to Hardenberg (1928).
Henry Ford took an early interest in fresh green soybeans; by 1923 they were being sold at Ford Motor Company stores (Nevins). Ford's interest increased during the 1930s. In 1934 ?? he served Buttered Fresh Green Soybeans at a gala soyfoods press luncheon at the Chicago World's Fair ?? In 1935 Edsel Ruddiman, a top Ford researcher, put up 590 cans of fresh green soybeans; the next year he put up 1,000 cans (Simons 1938 Ref??). The company was reported to have planted enough vegetable-type soybeans in 1941 to yield about 200,000 cans of fresh green soybeans. The entire pack was to be canned and used in the company commissary and stores (Dies 1942). It is not clear, however, whether this actually happened.
In 1929 Chung and Ripperton gave a nutritional analysis of fresh green soybeans grown in Hawaii, including the calcium, phosphorus, and iron.
William Morse and the Popularization of Vegetable-Type Soybeans . Prior to the early 1930s, only two large-seeded soybeans had been grown in America. These (Hahto and Easycook) had been found to be especially good tasting, yet no one had realized that they were but representatives of a larger type of soybeans, the vegetable type. Thus the term "vegetable-type soybean" had not yet been coined. As early as 1916 Piper and Morse wrote that "In quality the beans raised in Japan are said to be superior to those of Manchuria and Chosen (Korean), and are used exclusively for the manufacture of food products. The imported beans . . . from Manchuria . . . are used principally in the manufacture of bean cake and oil." They had not yet grasped the full significance of their own words and even in their classic The Soybean (1923) they made no mention of "vegetable-type soybeans."
During his expedition to East Asia from 1928-1931 (see Chapter 54), Morse finally became the first Westerner to understand the significance of the fact that vegetable-type soybeans were superior to field-type soybeans for food use. During the trip he collected roughly 150 of these large-seeded beans, mostly in Japan and Korea, and introduced them into the US germplasm collection via the Office of Seed and Plant Introduction (Probst and Judd 1973). Morse later noted that he had obtained one of each of the 125 varieties that Japanese horticulturalists classify as garden vegetables (Caldwell et al. 1947). In his travel log Morse also noted: "Another surprising thing is the very extensive use of the soybean as a green vegetable."
Back in the United States, Morse set out on a major one-man campaign to propagate the new large-seeded vegetable-type soybeans, to encourage others to study them and find the varieties best suited to American climates, soils, and foods, and then to popularize their use as food. Morse planted many of the varieties at the USDA Arlingtona Agricultural Experiment Station in Virginia and by 1934 (perhaps as early as 1932) the seed from these plantings was distributed to plant breeders at a number of other experiment stations, mainly in the Missouri and Ohio valleys. From 1936 about 30 of the most promising varieties were named and released for public use. Among the most famous were Rokusun, Higan, Sioux, Fuji, Aoda, Willomi, Imperial, Wolverine, and Hokkaido, all collected in Japan; Jogun, Kanro, Nanda, and Emperor, collected in Korea; and Cherokee, and Seminole, collected in China. One of these, Rokusun (PI 80481) had a 100-seed weight of 55 grams, the largest sized soybean seed known.
Morse wrote and spoke widely about the promise of the vegetable-type soybeans and fresh green soybeans. In 1935, at the 15th annual meeting of the American Soybean Association, he read a long paper on "Green Vegetable Soybeans," which was later reprinted in J.H. Kellogg's magazine Good Health (Oct. 1937). The first article ever run by the Soybean Digest on food uses of soybeans was Morse's "Shanghied . . A Super Food" (July 1941). There he explained why it had taken so long to understand the significance of the new beans: "Attempts to secure seed of these food varieties from Oriental countries met with little success, due to the fact that the edible types were classified under another name than soybean." He had asked for daizu , instead of eda-mame . In 1943 (Ref??) he reported that some vegetable-type soybeans would yield 2 to 2 l/2 times as much per acre as common lima beans. In September 1945 he wrote another article in Soybean Digest on "Future of Vegetable Varieties" stating his conviction that they held great promise in America for use as fresh, frozen, or canned soybeans. As late as 1952 he was still working to popularize his pride and joy.
From the late 1930s until the end of World War II there was a remarkable surge of interest in vegetable-type and fresh green soybeans in America. The various forces causing this were: (1) the pioneering work of William Morse, his great prestige, and his enthusiasm for vegetable and green soybeans; (2) the rising popularity of field-type soybeans and the feeling that these might be an even better new crop; (3) the strong early commitment to research by the University of Illinois and their very positive findings; and (4) the war, which set off a search for alternative protein sources, especially those that could be grown in home gardens.
The 1930s, Research and Development . By the middle to late 1930s many state agricultural experiment stations and university home economics departments had begun to test the new beans' growing performance and acceptability as foods. One of the most detailed of the early reports was "The Nutritive Value of Green Immature Soybeans (1934) by Miller and Robbins in Hawaii. They found that the fresh green beans contained 12-15% protein, an unusually large percentage for a fresh vegetable, and considerably more than lima beans (7.5%) or green peas (6.7%). Their iron content of 2.7 mg/100 gm exceeds that of most other common vegetables. They are a very good source of vitamins A and B, but are low in C; they are rich in calcium and phosphorus. They recommended boiling the beans in salted water for 15-25 minutes and serving them in the pods. Sherman and Salmon (1939 Ref??) also did an early vitamin study.
Probably the most influential and pioneering food and nutritional work was done at the Department of Home Economics of the University of Illinois, which from 1934-1936, ran tests on 466 soybean varieties, most of them edible types, to study their uses as fresh green or dry soybeans or as soy flour, testing flavor, texture, color, appearance, nutritional value, and, when used as fresh green beans, the shelling time and adaptability to different methods of preservation (freezing, canning, and drying). An excellent preliminary report was issued by Woodruff in 1937 entitled "Edible Varieties of Soybeans." The final results were published in 1938 in the 46-page "A Study of Soybean Varieties with Reference to their Use as Food," Bulletin 443 of the Illinois Agricultural Experiment Station. Six varieties, all of them vegetable types (Willomi, Imperial, Hokkaido, Jogun, Funk Delicious, and 97155) were rated as having superior qualities for food use and it was concluded that these six "might easily be accepted for table use by the American public." Another eleven varieties were rated as very good. Surprisingly, the detailed report failed to mention that, for the cook, the easiest way to serve fresh green soybeans is in the pod, letting each guest to do his or her own shelling, like unshelled peanuts. This also adds a leisurely touch to the luncheon or dinner.
While the University of Illinois Department of Home Economics was doing palatability studies, the Department of Agronomy was doing a parallel set of studies from 1935-1938 on yields, culture practices, maturing times, and suitability for home and market gardeners. The results were published in March 1939 in a remarkable 54-page report entitled "Eighteen Varieties of Edible Soybeans" by Lloyd and Burlison. Their 11 most recommended vegetable type beans contained an average of 40.7% protein on a dry weight basis (range: 36.4-42.9%) and an average 100-seed weight of 28.0 grams (range: 21.2-31.9 gm). From the 100-200 interested home gardeners who were sent trial seed packets each year came a heartwarming response. The vegetable-type soybeans were considered high yielding and resistant to drought, but above all the gardeners loved their flavor: "They were delicious . . . We like them better than peas or beans . . . I served soybeans to all guests this summer and most everyone liked them . . . Everyone who tried them said they were splendid . . . We have never eaten beans as good . . . The beans were delicious to eat and were universally liked by my family and guests. In fact it took persuasion to leave any for seed." Other representative comments from the hundreds printed in the report include: "I think the vegetable soy will soon become a standard vegetable . . . I think it is only a question of time until these beans are very popular." Reports from market gardeners were also positive: "I put some of the soybeans on our sales counter and found that about 80% of the people who tried the beans once came back for more." In a large grocery store in Chicago directions for shelling and cooking the fresh green beans were furnished with each purchase and over 1,200 pounds were sold in the first month. Canning companies reported that certain varieties made "a very fine canned product, the appearance being very good and the flavor excellent." Lloyd and Burlison rated five of the green vegetable soybeans as having excellent flavor, texture, and appearance: Jogun, Willomi, Imperial, Wolverine, and Emperor. Soon interest was widespread, with 3,000 requests for seed from all states, Hawaii, and seven foreign countries. At the end of 1939 reports were received back from 810 people who had been sent seeds of vegetable-type soybeans that spring; 80% reported success in growing a good crop and 70% were enthusiastic about their quality as a green vegetable.
Other good work with fresh green soybeans was done in the areas of recipe development and canning. In 1937 the University of Wisconsin had recipes in their bulletin "Soybean Dishes--New and Old." The USDA Leaflet No. 166 (Whiteman and Keyt 1938) included four recipes: with butter, salt, and pepper; scalloped and baked; in vegetable salads; and dipped in melted butter seasoned with soy sauce.
McBride (1940 Ref??) reported the unofficial estimate that in 1939 some 360,000 one-pound cans of fresh green soybeans were produced nationwide.
World War II (1940-1945) . The advent of the war transformed the research of the 1930s into widespread practical interest and utilization. During the war, when animal protein was in short supply, the federal and state governments made serious attempts to introduce green vegetable soybeans into the American diet. By 1941 extensive studies on the cooking quality and nutritional composition of vegetable-type soybeans (for both fresh green and whole dry use) had been made by the federal bureau of home economics and departments of home economics at numerous agricultural experiment stations. William Morse (1941) summarized their findings, which paralleled those of the University of Illinois: "Most of these edible types have been found to be much superior to the commercial varieties in flavor, texture, and ease of cooking. Moreover tests have indicated that the flour made from edible types has a better flavor . . . Some of the edible types have been judged to be superior to the commercial types in the manufacture of bean milk (soymilk), roasted beans (soynuts) . . . bean curd (tofu), and other products."
By the early 1940s nearly all agricultural experiment stations in the US and Hawaii were doing studies on vegetable-type soybeans. By 1941 some 42 varieties of vegetable-type soybeans had been found sufficiently promising to be assigned varietal names and have their seed stocks being grown out rapidly at agricultural experiment stations. Important reports on the new soybeans were published in 1940 and 1942 in Iowa, 1941 and 1942 in Hawaii, 1941 in Indiana (Purdue), 1942 in Alabama, 1942-45 in Maryland, 1944 in Nebraska and 1945 in Missouri (need 5 Refs??). Among these, the report by Weiss and co-workers at Iowa (1942) is especially valuable. Virtually every study gave the new soybeans high grades. Funk Brothers Seed Company did valuable research and breeding work and many people, most notably Professor G.M. Briggs at the University of Wisconsin and J.B. Park at Ohio State University did important promotional and research work.
Important nutrition and processing studies were done. Burrell and Wolfe (1940 Ref??), in attempting to determine whether any correlation existed between edible qualities and chemical composition, found no important differences except that the vegetable types contained less fiber. Salmon (1943 Ref??) estimated that a 100-gram serving of fresh green soybeans would supply 40% of the daily adult protein requirement. Parsons (1943 Ref??) and Everson and Heckert (1944 Ref??) reported the protein quality of fresh green soybeans to be superior to that of dry soybeans and comparable to that of casein or beef liver. Burkholder (1943) did a very comprehensive study of the vitamins in green vegetable soybeans, finding that they had 1.5 times as much riboflavin and twice as much niacin as dry soybeans. Also in 1943 Simpson wrote a 3-page summary in the Journal of Home Economics of the work by Woodruff and Klass at Illinois in 1938, and Walls (1943) published a detailed report on studies of canned vegetable-type soybeans done at the Maryland Experiment Station. Important findings were that the problem of the canning liquid jelling (it melted when heated) could be prevented by harvesting the beans early, before they became too mature, and that the soybeans could be hulled satisfactorily with a mechanical pea viner by using pea screens. "Studies of Canned Vegetable Soybeans," a summary of this and other studies, was published in Soybean Digest (October 1946).
Most of the cookbooks and other books working to popularize soyfoods during the war had substantial sections on fresh green soybeans, usually with recipes. Lager (1945), in her popular The Useful Soybean , gave a long discussion of the many virtues of the vegetable-type soybeans followed by many American-style recipes for using them as both fresh green and dried soybeans. A long section also appeared in the Cornell booklet on soybeans (Maynard et al. 1945).
Shortly after World War II began, the Victory Garden Program was started under the direction of the extension service of the War Food Administration. They encouraged people to plant home gardens containing vegetables that were of greatest value in protecting health and also easy to grow. They did extensive work in promoting green vegetable soybeans. In late 1943 (Ref?? see above) Morse was able to report that "During the past season vegetable soybeans were grown extensively in Victory Gardens . . . Vegetable soybeans led the list of new vegetables planted in the rural gardens in 1942 in South Carolina. Approximately 2,000 home demonstration club women in 44 of the 46 counties in South Carolina planted them in the vegetable garden for the first time." In 1944 Faulkner, Simpson, and Burlison at the University of Illinois wrote "Soybeans from Your Victory Garden" with recipes and tips on growing. Nationwide the most popular varieties were Hahto, Easycook, Kanro, and Hokkaido. Thus during the war tens of thousands of American families, especially in the Midwest, ordered Victory Garden packets of vegetable-type soybeans, planted them in home gardens, and enjoyed the fresh green soybeans at their dining tables.
Production of canned green vegetable soybeans skyrocketed during the war, increasing from an estimated 30,000 cases in 1941 (presumably 24 x 1-pound cans per case), to 100,000 cases in 1942, to 500,000 cases in 1943. Total acreage of commercial vegetable-type soybeans in 1943 was estimated at 12,000 acres, which was less than 0.1% of the acreage of field-type beans (Gold 1943). The directory of the National Canners Association listed 10 companies as canners of vegetable-type soybeans in 1940, with the largest of these producing eight railroad cars full of cans each year. Also in 1940 Dr. Harry Miller (see Chapter 58.5) had set up a plant in Mt. Vernon, Ohio to can the vegetable-type fresh green soybeans that he grew on a nearby farm. These soon became the company's most profitable product, with 40,000 cases a year being sold by 1943 to supermarkets (A&P was the biggest customer) and health food stores throughout the Midwest. By 1944 the number of companies canning soybeans had doubled to 23 in 12 states. The figures do not state clearly which companies were canning fresh green soybeans and which whole dry, but most were apparently green. During the war a Soybean Canners Association was organized by Mr. W. L. Schroeder, head of the Fox Valley Canning Company of Hortonville, Wisconsin; he had been canning soybeans since 1930 (after learning of their food value from the Chinese) and by 1945 he was growing 1,000 acres of an early-maturing vegetable-type soybean for canning. Another pioneer was R.P. Schmidt of the Nutrisoy Company, New York, New York.
Some vegetable soybeans were also sold frozen. Commercial freezing of the new beans, either alone or in combination with sweet corn as succotash began in early 1947 and was fairly popular in the Midwest.
A large proportion of the canned and frozen products were used by foodservice institutions. By the early 1940s institutions in Missouri were using the vegetable-type soybeans during the winter months as a green vegetable. Canned green soybeans were given relatively little promotion to the general public and for this reason they did not move well from grocers' shelves. In 1943 a USDA official (Ref??) noted that this may have been due in part to the fact that the FDA required that these fresh green soybeans be labeled "immature," and many consumers might hesitate to consume a food that was immature.
The Postwar Period (1946-1974) . The end of World War II brought with it a substantial loss of interest in green vegetable soybeans, which has largely persisted until the late 1970s. By 1946 the number of canning companies had dropped to 16 in 10 states. The USDA, however, maintained its interest and activity; in late 1947 they published a circular on "Canning Green Soybeans at Community Centers." Also in 1947 Caldwell and co-workers at the USDA published an excellent study comparing ways of preserving vegetable-type soybeans; taste panel judges were unanimous in rating mature dry soybeans as best, dehydrated green soybeans second, and canned green soybeans third. It also became clear at this time that, in terms of flavor, texture, and appearance, there was no one variety of vegetable-type soybean that was "best" for general food use or for drying, canning, or pressure cooking. Many were excellent and favorites varied mostly depending on the year, the soil, and the climate, rather than on varietal differences.
Van Duyne (1950 in her "Recipes for Using Soybeans" included five recipes for fresh green soybeans and good instructions for shelling, cooking, freezing, canning, and drying. Chen (1956) had numerous recipes in his Soybeans for Health, Longevity, and Economy . Smith (1959) reviewed data on the nutritional composition of vegetable- versus field-type soybeans and found that the vegetable types had no more protein than the field types (actually slightly less; 40.7 vs. 41.2%) and only slightly less oil (19.9 vs. 20.7%). The 1961 Soybean Blue Book listed only two canners of fresh green soybeans: Loma Linda Foods in Mt. Vernon, OH and Sterners Special Foods in Birdsboro, PA. In 1963 Mazur mentioned widespread interest in fresh green soybeans in Israel, especially among vegetarians, whose numbers were said to be rapidly increasing. The beans were reportedly carried at many health food stores. Standal (1963) made the very important finding that of all soyfoods studies, fresh green soybeans had the highest quality protein as measured by NPU (Net Protein Utilization). For example, the NPU of fresh green soybeans was reported to range from 71.5 to 73 as compared with 68.0 for casein, 65.0 for tofu, and 56.0 for soy sprouts.
Probably the most important work done during the postwar era with vegetable-type soybeans was in the field of plant breeding. It had been clear since the 1940s that the main limitation of the vegetable types as compared with the field types was agronomic. The former had lower yields and were hard to harvest at the mature dry stage due to shattering (some pods burst prematurely and the beans fall to the ground), which caused a further drop in yield and led to higher prices. During the 1960s and 1970s soybean breeders in Iowa (Weber) and elsewhere developed new vegetable types with somewhat improved agronomic qualities and larger seed size. The most important of these were Disoy (Maturity Group I), Magna and Prize (II), and Kim, Kanrich, and Verde (III).
1975-1982 . Starting in the late 1970s there was a rebirth of interest in both fresh green soybeans and vegetable-type soybeans, after almost 30 years of neglect. Some of the first Japanese recipes for cooking fresh green soybeans were given in The Book of Tofu (Shurtleff and Aoyagi 1975). Bates and co-workers (1977) found that fresh green soybeans had very high protein quality as measured by PER (Protein Efficiency Ratio); 2.05 as compared with 2.11 for dry soybeans and 2.02 for 4-day soy sprouts. Rasmussen (1978) reported that the fresh green beans contained more zinc and supported growth of rats better than dried soybeans. Green vegetable soybeans began to be featured in many home garden seed catalogs.
The Rodale Research Center and Rodale Press in Emmaus, Pennsylvania played an important role in studying and popularizing fresh green soybeans. Many articles about them were published in Organic Gardening magazine. Lawrence (1981a,b) gave tips for growing them, plus cooking suggestions and recipes. Edwards and Gilbert (1981) reported that taste panels found fresh green soybeans to taste sweet, nutty, mild, and attractive. Verdee and Kanrich varieties were given high grades. Haas, Gilbert, and Edwards (1982) tested 45 lines of large-seeded vegetable-type soybeans for field performance, then evaluated 39 of these for sensory/taste properties. Eight varieties that exhibited both good field and sensory qualities were identified and their source (see catalogs) listed. Interestingly, four of the eight top varieties came from Takii & Co. in Kyoto, Japan. In addition to Rodale, Rackis of the USDA wrote a number of comprehensive articles on fresh green soybeans in the late 1970s, and in 1980 Pritzlaff wrote a nice article in The Mother Earth News on how to grow and freeze them.
Yet despite all this interest in the fresh green beans, the only ones that were on the market were imported from Japan and sold, fresh or packed in broth in a few Oriental markets. (Loma Linda sold a dry soybean with a green seed coat, canned and labeled Green Soybeans). The growing interest in this fine product and its general unavailability would seem to point to a good market opportunity. Natural food stores around America could contract with local gardeners or farmers to supply them with the fresh beans, and at least one company should try making a canned product. We feel that fresh green soybeans are an idea whose time had come . . . again.
Likewise with large-seeded dry vegetable-type soybeans, Strayer Seed Farms in Hudson, Iowa played a key role from the 1970s in offering these for sale to soyfoods processors in America and Japan. Estimates of the amount of vegetable-type beans grown in the US in 1980 ranged from 5,000-25,000 acres, or less than 0.04% of the total US soybean crop. The most popular varieties were Prize and Vinton. Most of these large-seeded soybeans were used to make soynuts, tofu, and soymilk, and roughly half were sold overseas, mainly in Japan. Virtually none of the commercial crop was served as fresh green soybeans--a real shame. These large-seeded soybeans weighed 60-80% more per seed (280 vs. 160 mg/seed) than field-type beans, sold for 12-18% more per unit weight, and gave 20-39% lower yields per acre. Vinton was expected to give yields only 10% lower. Clearly there remains a great need for breeding work to improve varieties.
HISTORY OF FRESH GREEN SOYBEANS IN THIRD WORLD COUNTRIES
Outside of East Asia, fresh green soybeans are virtually unknown in the Third World. Yet it is there that their potential and promise is perhaps the greatest, since most rural families eat primarily unprocessed food grown in their home gardens or farms (or that traded in local markets), and since soybeans are increasingly recognized as one of the best foods for combatting protein-calorie malnutrition. The work of introducing fresh green soybeans to Third World countries done by the Asian Vegetable Research and Development Center in Taiwan is a promising first step. It is heartening to hear that in Bangladesh, fresh green soybeans have recently come to be grown and used in pilafs and curries (Smith 1975). Hopefully in the years to come national soybean programs will recognize their potential importance and work to give them the place they deserve in diets around the world.