Optimization of fermentation process of strawberry-Jiaosu by response surface methodology and the primary study of bioactivity

Study on the optimum fermentation process and its antioxidant activity and related enzyme activity in strawberry-Jiaosu. On the basis of single factor experiment, the best fermentation process of strawberry-Jiaosu was optimized by the response surface method with yeast inoculation amount, ation time, fermentation temperature as independent variable and SOD as response value. The results showed that when the inoculation amount of yeast was 1.5%, the fermentation time was 13.5 h, and the fermentation temperature was 35℃, the SOD value was 35.98 U/mL. In vitro antioxidant test showed that strawberry-Jiaosu had strong hydroxyl free radical scavenging ability (79.38%), DPPH radical scavenging ability (88.89%), superoxide anion free radical scavenging ability (74.40%)and reducing power (0.542). But its antioxidant capacity in vitro with the storage time to extend the degree of reduction to varying degrees. The results of enzyme activity in strawberry-Jiaosu showed that SOD activity was the strongest, followed by lipase, and the activity of amylase was the lowest. It was suggested that the strawberry-Jiaosu might have a good prospect.