Objective:In order to study the optimal enzymatic hydrolysis process conditions of corneum galli gigerii endothelium, and analyze the amino acid composition, molecular weight distribution and antioxidant activity of the enzymatic hydrolysate.Methods:With the yield of polypeptide and the degree of hydrolysis as indicators, the orthogonal experiment was used to optimize the enzymatic hydrolysis conditions of corneum galli gigerii endothelium. Amino acid analyzer and high-performance gel permeation chromatography were used to determine the amino acid composition and molecular weight distribution of the enzymatic hydrolysate of corneum galli gigerii endothelium. The clear ability of corneum galli gigerii endothelium to DPPH free radicals and ABTS+radical were also investigated.Results:The results showed that the optimal enzymatic hydrolysis conditions of corneum galli gigerii endothelium were as follows: co-enzymatic hydrolysis with neutral protease and alkaline protease, enzymatic hydrolysis temperature at 60 ℃, enzymatic hydrolysis for 9 h at pH 11, and cooking time for 6 h. Under the control of these conditions, the yield of polypeptide was 75.68%, and the degree of hydrolysis was 14.43%. The ratio of the essential amino acid to the non-essential amino acid of the enzymatic hydrolysate was58.56%, which has high nutritional value. The proportion of enzymatic hydrolysate with a relative molecular mass of ＜1 000 Da accounts for 90.2%, which was easy to be digested and absorbed. When the concentration of the enzymatic hydrolysate was1.5 mg/mL, the scavenging rate of ABTS+free radicals reached 94.19%.Conclusion:Using the optimal enzymatic hydrolysis process strategy, the yield of corneum galli gigerii endothelium polypeptide is as high as 75.68%, and it has good antioxidant activity.