Changes in Isoflavone and Oligosaccharides of Soybeans during Germination

Three Korean soybean varieties, Dawon, Taekwang, and Myeongiju-namul were investigated for changes in isoflavone and oligosaccharides contents, and dry weight during germination. Soybeans were soaked for 10 hr in water, followed by 8 days germination at under dark condition, Highest isoflavone content measured was Myeongju-namul (1.228 mg/g), followed by Taekwang (0.671 mg/g) and Dawon (0.661 mg/g). Total isoflavone content generally increased during initial germination and decreased thereafter. Maximal increase in isoflavone was 20-50%, particularly in aglycone type such as daidzein and genistein. Raffinose and stachyose contents decreased rapidly during germination, while that of sucrose showed relatively slow decrease. Dry weights of soybeans steadly decreased.