The soybean (U.S.) or soya bean (UK) (commonly misspelled "Soyabean") (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 over 30,000 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 ?? (????, shoyu), 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 another 5,000 years old Chinese invention, and the oil is used in many industrial applications. The main producers of soy are China, the United States, Brazil and Argentina. Soybean contain significant amounts of alpha-Linolenic acid, an omega-3 fatty acid, and the isoflavones genistein and daidzein. Sterol esters are a heterogeneous group of chemical compounds known to reduce the level of low-density lipoprotein (LDL) cholesterol in blood when ingested. The starting material are phytosterols, which are then esterified with a mixture of fatty acids also derived from plants. Sterol esters are found naturally occurring in small quantities in fruits, vegetables, nuts, seeds, cereals, legumes, and vegetable oils. Sterol esters are added to certain oil-containing products like margarine, milk, or yogurt. Studies have indicated that consumption of about 2 grams per day provides a reduction in LDL cholesterol of about 10 percent. Its functionality is similar to that of stanol ester. Sterol esters are added to certain Unilever products under the brand name Becel/Flora.