Soybeans belong to the pea family (Leguminosae) and are among the first crops cultivated by humans. Since the 11th century B.C., soybeans have been grown in China, where they were the most important crop. Soybeans made their way to Japan in the 7th century, to Europe in the 17th century, and to the United States in 1804. Today soybeans are everywhere. They are the world's leading legume crop, with more than 100 million metric tons produced annually.
Soybeans have a bright future in the global kitchen. They are currently processed for consumption as oil in margarines, shortenings, and salad dressings, and as protein in tofu, miso, tempeh, soy milk, meat extenders, and meat replacements (for example, bacon-like bits, simulated sausages, etc.). As the nutritional and health benefits of soybeans become better known, soybeans are sure to become dietary superstars. But for now, think of soybeans as undiscovered actors whose time will soon come in the theater of global nutrition.
Soybeans are 13 to 25 percent oil, 30 to 50 percent protein, and 14 to 24 percent carbohydrate. They are an excellent source of essential fatty acids (those which are not produced by the body and therefore must be consumed in the diet). Good sources of complementary protein when consumed with cereal grains, soybean products are comparable to milk, a high-quality protein, in essential amino acids. "When well-processed soy products serve as the major or sole source of protein intake, their protein value approaches or equals that of foods of animal origin, and they are fully capable of meeting the long-term essential amino acid and protein needs of children and adults", say V.R. Young and N.S. Scrimshaw of the Massachusetts Institute of Technology's Clinical Research Center and Department of Nutrition and Food Science.
(See The Story of Wheat, and The Story of Rice.)