Abstract:The preparation process for bayberry juice from chestnut was optimized using two process optimization methodologies.Process parameters such as the compound enzyme，the enzymolysis time，and optimum temperature were optimized by performing single-factor tests.On the other hand，the physical and chemical indices for bayberry juice digestion，the active ingredients，the juice color，and the antioxidant activity were optimized using the response surface methodology.It was determined that the best complex enzyme to be used was pectinase，and that its optimal mass ratio with the vitamin enzyme was 3 ∶1.Furthermore，the optimal conditions for the enzymatic preparation of bayberry juice included the addition of 0.40% complex enzyme，and the enzymolysis duration and temperature at 60 min and 45℃，respectively.Using these parameters，a bayberry juice yield of 85.27% was achieved.With the optimized protocol，the color of the bayberry juice significantly improved，and the total phenol，totalflavonoid，anthocyanin and protein contents increased by 58.21%，67.80%，221.29% and 209.83%.Respectively.Moreover，a significantly improved DPPH free-radical scavenging ability and ferric ion reducing antioxidant power（FRAP）total antioxidant capacity was observed from the juice produced using the optimized process.