Optimization of preparation of Tilapia skin antioxidative peptides with enzymatic hydrolysis by response surface methodology

Response surface methods were used to optimize the hydrolysis conditions of Tilapia skin for production of antioxidant peptides. Half inhibitory concentrations of DPPH radical,hydroxyl free radical and reducing power capacity were selected as the indexes to compare the effect of hydrolysis and product antioxidant activity of 6kinds of commercial enzymes( acid protease,neutral protease,alkaline protease,trypsin,bromelain and papain).The result showed alkaline protease was optimum enzyme.Then the hydrolysis conditions was optimized by response surface methodology. The hydrolysis conditions were p H10.00,hydrolysis time of 4 h,hydrolysis temperature of 40 ℃,ratio of material to water of 0.38 g / m L.Under such conditions,the reducing power was 1.054,which was consistent with the model prediction.