Properties and Applications of Soy Proteins

Soybeans have been cultivated for more than 3000 years in China and other Asian countries, such as Japan and Korea. Soybeans have been an important protein source in Asian countries and have been utilised in various forms such as tofu (soybean curd), miso (fermented soybean paste), natto (fermented soybeans covered with mucilagenous substance), and aburage (fried sheet of tofu), among others. In addition to these traditional foods, an increased amount of soybean milk is now consumed in Japan and China due to its expected health benefits. The advantages of soybean proteins are: 1) they provide a good balance in amino acid composition as they contain all the essential amino acids; 2) they contain physiologically beneficial components shown to lower cholesterol and reduce the risk of hyperlipidemia and cardiovascular diseases; and 3) they have excellent processing abilities such as gelling, emulsifying, and water- and oil- retention. Soluble soybean polysaccharides extracted from residue (okara) in tofu-curd production have been shown to be a good emulsifier and have been widely used in the food industry.