Abstract: Objective:Papain and bromelain were used to hydrolyze Paphia undulate to make bioactive peptide respectively.Method:The hydrolysis processes of Paphia undulata by the two enzymes were optimized by orthogonal test respectively.Results:The results showed that the optimal hydrolysis conditions of papain are:temperature 50 ℃,time duration 4 h,enzyme amount 4.0%,ratio of substance to water 1:3 and pH 6.3.The hydrolysis degree is 40.83%,the recovery of total is 89.85%,and the average length of peptide chain is 2.20;For bromelain,the optimal hydrolysis conditions are:temperature 55 ℃,time duration 4 h,enzyme amount 12.0%,ratio of substance to water 1:3 and pH 6.3.The hydrolysis degree is 34.61%,the recovery of total nitrogen is 89.58%,and the average length of peptide chain is 2.58.Conclusion:In this study,papain is better than bromelain for hydrolyzing Paphia undulata.

Key words: bioactive peptide, Paphia undulata, papain, bromelain