Preparation and antioxidant properties of the hydrolysate and frations from Mytilus edulis by papain

In the present study, the preparation process of the antioxidant hydrolysate and fractions from Mytilus edulis by papain were studied. The optimal conditions of papain hydrolysis was obtained by single-factor experiments and orthogonal test with the DPPH· scavenging ratio as index. Under the optimal hydrolysis conditions of the temperature 65°C, pH 7.0, enzymatic hydrolysis time 3 h and amount of enzyme 1.0%, the high DPPH radical scavenging activity (28.74) of the total hydrolysate was obtained. The fraction F2 with the highest antioxidant activity was collected using Sephadex G-25 column from the total hydrolysate, with the reducing power, ·OH and DPPH· scavenging ratio being 0.807, 10.44% and 31.4% at the concentration of 5 mg/ml. The results revealed that the enzymatic hydrolysis method was appropriate for obtaining the product with the high antioxidant activity from the mussel protein and the F2 mainly contributed to the antioxidant activities of the total hydrolysate.