The soybean (U.S.) or soya bean (UK) (Glycine max) is a species of legume native to East Asia. The plant is classed as an oilseed rather than a pulse. It is an annual plant that has been used in China for 5,000 years as a food and a component of drugs. Soy is a good source of protein because it contains a significant amount of essential amino acids. Soybeans are the primary ingredient in many processed foods, including dairy product substitutes. The plant is sometimes referred to as greater bean (China) or edamame (Japan), though the latter is more commonly used in English when referring to a specific dish.
The English word "soy" is derived from the Japanese pronunciation of 醤油 (しょうゆ, shōyu), the Japanese word for Soya sauce; soya comes from the Dutch adaptation of the same word.
Soybeans are an important source of vegetable oil and protein world wide. Soybean products are the main ingredients in many meat and dairy substitutes. They are also used to make soy sauce, and the oil is used in many industrial applications. The main producers of soy are the United States, Brazil, Argentina, China and India. The beans contain significant amounts of alpha-Linolenic acid, an omega-3 fatty acid, and the isoflavones genistein and daidzein.