Soybeans are an economically important crop, which serves as a source of good-quality proteins for animals and humans, making it extremely important from nutirional and health point of views. Consumption of soy foods is increasing because of reported beneficial effects on nutrition and health (Friedman et al., 2001; Wong et al., 2008; Omoni et al., 2005).
The storage soy proteins consist of a mixture of proteins (α-, β-, and γ-conclycinins, glycinin, and other globulins). The seeds also contain bioactive proteins including β-amylase, cytochrome c, lectin, lipoxygenase, urease, and others; as well as secondary metabolites including isoflavones, saponins, phytic acid, flatus-producing oligosaccharides, and goitrogens (Friedman et al., 2001). Isoflavones have been proposed to be the active component responsible for the beneficial effects of soybean foods, and appear to work in conjunction with the proteins to protect against age-related diseases including cardiovascular disease, osteoporosis, hormone-dependent cancer and loss of cognitive function (Wong et al., 2008; Omoni et al., 2005).
Soy foods consumption has effects including lowering of plasma cholesterol, prevention of cancer, diabetes, and obesity, and protection against bowel and kidney disease (Friedman et al., 2001). Thus, the study of soybean metabolites is very important both from the nutritional as well as the disease prevention perspectives