Optimization of enzymatic hydrolysis conditions parameters for antioxidant capacity of hydrolysates from protein of Tilapia heels

Antioxidant peptide can inhibit radical scavenging activities and be obtained by hydrolysis some proteins.The tilapia heels protein was hydrolyzed with four kinds of enzymes.Antioxdant activity was investigated using radical scavenging activity assay for superoxide free radical(O2-·),1,1-diphenyl-2-picrylhydrazine(DPPH·) and linoleic acid peroxidation for the hydrolysates from different hydrolysis times with four kinds of enzymes.The results showed that the hydrlysate with alikaline protease had a high antioxidant activity.The optimal hydrolysis conditions obtained from experiment was the enzyme concentration of 2000U/g,substrate concentration of 3%,temperature of 50 ℃,pH of 9.5 and hydrolysis time of 4 h.Meanwhile,the degree of hydrolysis was 24.21%,and the radical scavenging efficient was 36.24% for O2-·,76.91% for DPPH· and 66.87% for linoleic acid peroxidation,respectively.Therefore,preparation of antioxidant polypeptide by hydrolysis of the tilapia heels protein was feasible.