Evaluation of thE antioxidant activity of collagEn PEPtidE additivE ExtractEd from cod Skin

in this study, cod skin was used as raw material to extract collagen polypeptide (with the purpose of using as a feed additive) using double-enzyme composite hydrolysis. the degree of hydrolysis was used as an index in orthogonal tests to determine the optimum conditions for zymohy- drolysis. our results showed that, with alkali protease and papain content of 4 and 4.5%, respectively, at 55°C and ph 8, the degree of protein hydrolysis reached 25.61% after 11 h. Polypeptides with a relative molecular mass (Mr) under 3500 u constituted 82% of the total obtained polypeptides. Data from the antioxidation experiment suggested that the resultant hydrolysates exhibited good antioxidant activity.