Soybean

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Soybeans

Scientific classification

Kingdom:	Plantae
Phylum:	Magnoliophyta
Class:	Magnoliopsida
Order:	Fabales
Family:	Fabaceae
Subfamily:	Faboideae
Genus:	Glycine
Species:	G. max

Binomial name

Glycine max
Merr.

Soybeans (US) or Soya beans (UK) (Glycine max) are a high-protein legume (family Fabaceae) grown as food for both humans and livestock. The word soy is derived from the Japanese word shoyu (soy sauce/soya sauce).

1 Applications
2 Soybean production
3 Nutrition and health effects
4 See also
5 References
6 External links

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Applications

Toasted soybeans

Soybeans may be boiled whole (in the green pod) and served with salt, often under the Japanese name edamame. Soybeans prepared this way are a popular local snack in Hawai'i, where, like in Japan, China, and Korea, the bean and products made from the bean (miso, natto, tofu, douchi, etc.) are a significant part of the diet.

The beans can be processed in a variety of ways. Common forms of soy (or soya) include soy meal (often used as animal feed), soy flour, tofu, textured vegetable protein (TVP, which is made into a wide variety of vegetarian foods, some of them intended to imitate meat), tempeh, soy lecithin and vegetable oil. Soybeans are also the primary ingredient involved in the production of soy sauce (or shoyu).

Soybeans were discovered by George Washington Carver to be a valuable source of protein and oil. He also encouraged farmers to use crop rotation. Peanuts, soybeans, sweet potatoes or other plants that would replenish the soil with nitrogen and minerals were planted for two years and then cotton on the third year.

Soybeans grow throughout Asia and North and South America.

Many traditional dairy products have been imitated using soybeans, and products such as soy milk, soy yogurt and soy cream cheese are readily available in most supermarkets. These products have similar texture and appearance to milk-based ones; however regular soy milk does not contain significant amounts of calcium, since the high calcium content of soybeans is bound to the insoluble constituents and remains in the okara. Many manufacturers of soy milk now sell calcium-enriched products as well. Tofu often contains high amounts of this important mineral since calcium salts are used to coagulate the protein in soy milk when creating tofu. Additionally, soy protein has been found to reduce renal excretion of calcium, an effect that is reinforced by soy products' high potassium content.

Most soy products must not be fed to infants. In some cases, infants fed normal adult soy milk on a long-term basis have become extremely malnourished and even died. In addition, soy allergies are one of the more common food allergies. In recent times, however, specially designed soy infant formula has been made available. Like dairy formulas, these new soy based formulas contains extra vitamins and other nutrients to make it compatible with an infant's needs. Due to the estrogenic effects, soy based infant formulas have raised concern amongst researchers as a possible cause of early puberty in girls and delayed or retarded physical maturation in males.

Soybeans are also used in industrial products including oils, soap, cosmetics, resins, plastics, inks, crayons, solvents, and biodiesel.

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Soybean production

Varieties of soybeans are used for many purposes.

Soybeans are native to southeast Asia, but 45 percent of the world's soybean area, and 55 percent of production, is in the United States. The US produced 75 million metric tons of soybeans in 2000 of which more than one-third was exported. Other leading producers are Brazil, Argentina, China, and India. Much of the US production is either fed to animals or exported, though US consumption of soy by people has been increasing. Although the bean has been praised for various qualities, environmental groups like Greenpeace have complained that soybean cultivation in Brazil is encouraging Amazon rainforest deforestation.

Soy oil makes up 80% of the edible oil consumption in the United States. Soybean oil extraction is performed on a large scale in the U.S., especially by Cargill. The soybeans (18-20% dry wt. oil) are crushed and ground, then extracted with cyclohexane. The oils are blended for their applications, and sometimes hydrogenated. The oils are exported abroad, sold as vegetable oil, or end up in a wide variety of processed foods. New processes increasingly prepare protein isolates for use as food additives or health supplements. The remaining soybean husks are used mainly as animal feed.

Soybeans are one of the crops that are being genetically modified, and GMO soybeans are being used in an increasing number of products. Currently, 80% of all soybeans cultivated for the commercial market are genetically modified. Monsanto is the world's leader in genetically modified soy for the commercial market. As specialty soy products such as tofu and soymilk increase in popularity, production may very well shift from health-conscious, organic, non-GMO firms to larger firms that buy from the general food supply. In this manner, tofu and soymilk could drop in price with respect to established commodities such as meat and milk.

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Nutrition and health effects

Soybeans are considered a source of complete protein, i.e., protein that contains significant amounts of all the essential amino acids that must be provided to the human body because of the body's inability to synthesize them. For this reason, soy is important to many vegetarians and vegans. Soy protein is essentially identical to that of other legume seeds. The only non-legume to have an almost identical protein profile to soy is the cereal oat (Avena sativa), and perhaps quinoa. Soybeans also have the highest protein yield per acre of all crops.

Of any studied legume, whole soybeans have the highest levels of phytic acid, a mineral chelator also found in many common nuts and grains, such as walnuts and maize. Phytic acid binds to certain ingested minerals, reducing the amount the body assimilates. For people with a particularly low intake of essential minerals, especially children and those in developing countries, this effect can be undesirable. However, dietary mineral chelators help prevent over-mineralization of joints, blood vessels, and other parts of the body, which is most common in older persons. The Journal of Environmental Nutrition (April 2004 volume 27 issue 4) has also stated phytic acid may be considered a phytonutrient, providing an antioxidant effect.

In spite of the chelating effects of phytic acid, soybeans remain a good source of iron, magnesium, zinc, potassium, phosphorus, calcium, and manganese. They are also high in fiber and vitamin C.

Soybeans also contain isoflavones, forms of phytoestrogen that are considered by many to be useful in the prevention of cancer. Isoflavones are phenolic compounds, produced primarily by beans and other legumes, including peanuts and chickpeas.

Conversely, a 1985 animal study showed that young rats fed large amounts of soy products as their primary food source showed an increased risk of pancreatic cancer. This is probably because rats are extremely sensitive to dietary protease inhibitors like those found in soybeans, which can disrupt the action of digestive enzymes needed to break down protein. This condition has not been found in many other animals, and is not known to occur in humans.

Soybeans are also high in phytic acid or phytates. This is an organic acid, present in the bran or hulls of all seeds, which blocks the uptake of essential minerals-calcium, magnesium, iron and especially zinc-in the intestinal tract. Scientists are in general agreement that grain and legume based diets high in phytates contribute to widespread mineral deficiencies in third world countries. [1]

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