Study on Content Change of Soybean Isoflavone by High-salt Liquid-state Fermentation and Low-salt Solid-state Fermentation

In order to obtain the high activity of genistein and daidzein in soybean,variation of content and composition of soybean isoflavone in soy sauce is explored by high-salt liquid-state fermentation and low-salt solid-state fermentation.In the study,with variation of genistein and daidzein,the content of soybean isoflavone in high-salt liquid-state fermentation and low-salt solid-state fermentation is determined by high performance liquid chromatography(HPLC).The result shows that the content of daidzein and genistein in high-salt liquid-state fermentation reaches the peak of6.92μg/mL and 7.69μg/mL in 60 days;while the content of daidzein in low-salt solid-state fermentation reaches the peak of 5.92μg/mL in 20 days and the content of genistein of 5.83μg/mL in30 days.The content of soybean isoflavone of the later is faster and reaches the peak in a shorter time,however,the former is higher and has better flavor.This study has provided a theoretical basis for making more favorable and high activity soy sauce.