The soybean is a legume native to East Asia and grown in many countries throughout the world. Soybeans are considered by many agencies to be a source of complete 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 a good source of protein for vegetarians and vegans or for people who want to reduce the amount of meat they eat. Non-fermented products include edamame, soy milk, soy yogurt. Fermented products include soy sauce, tempeh and tofu.
Soybeans have been grown for centuries as a food product, particularly in Asian countries and were originally used in the U.S. as a fertilizer and for crop rotation due to their ability to “fix” nitrogen in the soil. According to an ancient Chinese myth, in 2853 BCE, the legendary Emperor Shennong of China proclaimed that five plants were sacred: soybeans, rice, wheat, barley, and millet. Soy was first introduced to Europe in the early 18th century and to British colonies in North America in 1765, where it was first grown for hay. Benjamin Franklin wrote a letter in 1770 mentioning sending soybeans home from England. Soybeans did not become an important crop outside of Asia until around 1910. In America, soy was considered an industrial product only, and was not used as a food prior to the 1920s.
In 1932–33, the Ford Motor Company spent approximately $1,250,000 on soybean research. By 1935, soybean oil was used to paint Ford automobiles, and was used as fluid for shock absorbers. Henry Ford promoted the soybean, helping to develop uses for it both in food and in industrial products, such as body panels made of soy-based plastics, as well as products like soy milk, ice cream and all-vegetable nondairy whipped topping.
Soybeans can grow in any kind of soil and do best in a climate with hot summers. The height of the plant varies from less than 0.2 to 2.0 m (0.66 to 6.6 ft).The pods, stems, and leaves are covered with fine brown or gray hairs. The fruit is a hairy pod that grows in clusters of three to five, each pod is 3–8 cm long (1–3 in) and usually contains two to four (rarely more) seeds. Raw soybeans, including the immature green form, are toxic to humans, swine, and chickens, thus they must be cooked before they are consumed. The U.S., Argentina, Brazil, China and India are the world’s largest soybean producers and represent more than 90% of global soybean production.
Consumption of soy may reduce the risk of colon cancer, possibly due to the presence of certain lipids, or fats. Eating soy products is associated with a reduction in prostate cancer risk in men, breast cancer among women and may reduce the risk of colorectal cancer. Recent studies have shown improvement in cognitive function, particularly verbal memory, and in frontal lobe function with the use of soy supplements. The FDA has also approved soy as a cholesterol-lowering food product.
Soybeans can be processed and consumed in a number of ways. Soybean pods, also known as edamame, can be steamed and eaten lightly salted. Soy Milk is also a substitute for cows milk for lactose-intolerant individuals, although it does not naturally contain significant amounts of digestible calcium. Soy milk can be made into yogurt, ice cream, cheese and margarine. Soy infant formula is often given to babies that cannot process pasteurized milk. Tempeh or fermented cakes can be crumbled and substitute for chicken and ground beef in various recipes. Miso, a Japanese cooking staple, is a thick paste used for sauces and spreads, pickling vegetables or meats, and mixing with dashi soup stock to serve as miso soup.
Tofu, first introduced by the Chinese, is also called bean curd and is made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is used in many Asian cuisines. Tofu has a subtle flavor and can be used in savory and sweet dishes. It is often seasoned or marinated to suit the dish. Soy Sauce is a condiment made from a fermented paste of boiled soybeans, roasted grain, brine, and a mold called aspergillus. Most varieties of soy sauce are salty, earthy, brownish liquids intended to season food.
Industrial uses for soybeans include animal and fish feed, oils, soap, cosmetics, resins, plastics, inks, crayons, solvents, and clothing. Soybean oil is the primary source of biodiesel in the United States, accounting for 80% of domestic biodiesel production. The soybean is now the prime source of steroidal drugs, including contraceptives and steroidal anti-inflammatory drugs like progesterone and cortisone.
As soybeans are a sustainable, renewable source of protein and oil, the National Soybean Research Laboratory and United Soybean Board report that researchers are continuing to develop new uses for soybean-based products for worldwide use.