Abstract:Peach jiaosu was prepared by fermentation with different bacteria and pretreated with different enzymes, and the effects of fermentation with different bacteria and enzyme treatments on the fermentation and antioxidant activity of peach jiaosu were investigated. The pH value and soluble solids content of peach jiaosu decreased rapidly in the initial stage of fermentation and slowed down in the later stage. The ability of scavenging O2·ˉand DPPH· increased rapidly in the initial stage of fermentation, but slowed down after 50 h of fermentation. After 60 hours of fermentation, the soluble solids content of each group decreased from 5.00 °Brix to about 3.60 °Brix. Peach jiaosu produced by yeast had higher ability to scavenge O2·ˉ and DPPH·, 43.70% and 38.25% respectively. According to the sensory evaluation results from high to low score, the order of fermentation bacteria were yeast, bifidobacterium-7 and 10, streptococcus lactis-5 and lactobacillus plantarum. Both pectinase and cellulase 1.5 L could significantly increase the soluble solids content in peach juice. Enzymatic pretreatment could improve the ability of scavenging O2·ˉ and DPPH· of peach serum. The clarified peach fermentation liquid could be obtained by pectinase treatment, which could also improve the flavor of peach jiaosu. The peach jiaosu treated by pectinase SPL had the best aroma and taste.
