Kombucha fermentation enhances the health-promoting properties of soymilk beverage

Soymilk fermentation with kombucha was perfomed at 28 degrees C and 37 degrees C, and changes in the number of micro-organisms, bioactivity and chemical compositions were analyzed during fermentation. Yeast, acetic acid bacteria (AAB), and lactic acid bacteria (LAB) showed substantial growth in the soymilk, and fermentation at 37 degrees C and 28 degrees C promoted the growth of LAB and AAB, respectively. The flatulence factors of raffinose and stachyose were entirely and mostly consumed during fermentation, respectively. Nearly all the glucoside isoflavones were transformed into aglycone isoflavones by beta-glucosidase hydrolysis. Total phenolic, ferulic, chlorogenic and ascorbic acid (VC) contents significantly increased after fermentation. The antioxidant and inhibition activities to alpha-glucosidase and alpha-amylase of kombucha-fermented soymilk significantly increased, and were higher at 37 degrees C than at 28 degrees C. In conclusion, fermentation with kombucha can enhance the health-promoting properties of soymilk.