Fermentation-enzymatic coupling method for daidzein transformation

The commercially available soybean isoflavone powder was used as sample, LJ-Q2 strain with β-glucosidase was selected and coupled with optimized immobilized β-glucosidase.The coupling conditions were optimized by single factor and response surface method. The content of soybean isoflavone glycoside was determined by high performance liquid chromatography ( HPLC) . The effects of coupled fermentation conditions on the conversion of daidzein were investigated.The results of optimal conditions were as follows: temperature 54 ℃, coupling time 3 h, initial p H7, immobilized enzyme addition amount 7%.The absolute quality of soybean isoflavone aglycon was 13.76 mg, the conversion rate of soybean isoflavone aglycon was 76.8%, application of technology development for soybeans glycosides had reference value.