Study on Enrichment and Composing Characteristics of Soybean Isoflavones in Germinated Soybean

Objective To determine the optimum conditions for enrichment of soybean isoflavones in germinated soybean and analyze its composing characteristics.Methods The content of soybean isoflavones was determined by UV spectrophotometry.After the suitable length of germinated soybean was fixed,in order to determine the optimal enrichment conditions,the effects of soaking time,culture temperature and humidity on the content of soybean isoflavones were researched by a L_9(3~4) orthogonal test.Then the composing characteristics of isoflavones in germinated soybean obtained under the optimal enrichment conditions were analyzed by HPLC method.Results The optimal enrichment conditions of soybean isoflavones were identified as soaking time of 16 h,culture temperature of 25℃,culture humidity of 90%when the length of germinated soybean was 30mm.Under these conditions,the isoflavones primarily consisted of three monomers which were genistein,daidzein and glycitein.Conclusion The optimization of culture conditions of germinated soybean can enrich isoflavones,especially increasing the contents of function factors such as genistein and daidzein,which provides some theoretical guidance for the further development of functional,isoflavone-rich soybean food.