Abstract:Objective To prepare oligopeptides from Lueyang black-bone chicken in order to increase its added value and to determine their antioxidant activity.Methods Lueyang black-bone chicken meat was used as the raw material. Two proteases were employed for compound enzymatic hydrolysis, and response surface methodology was applied to optimize the preparation process of Lueyang black-bone chicken oligopeptides and to evaluate their antioxidant activity.Results The optimal preparation process for compound hydrolysis of Lueyang black-bone chicken oligopeptides was as follows: neutral protease and acid protease in combination, substrate concentration 3 g/100 mL, enzymatic hydrolysis time 4 h, total enzyme addition 9 300 U/g, hydrolysis pH 6.5, and enzyme ratio 1∶1. Under these conditions, the hydrolysate had the highest trichloroacetic acid (TCA)-soluble short peptide content of 10.29 mg/mL, which was close to the predicted value, with a protein recovery rate of 71.52%. The IC50 values of Lueyang black-bone chicken oligopeptides for scavenging DPPH radicals, ABTS+ radicals, and hydroxyl radicals were 4.675 mg/mL, 31.401 μg/mL, and 4.769 mg/mL, respectively, and the reducing ability of 10 mg/mL oligopeptides was close to that of ascorbic acid at 0.02 mg/mL.Conclusion The experimental process can yield a considerable amount of Lueyang black-bone chicken oligopeptides with antioxidant activity.