Abstract:The purpose of this study was to optimize enzymatic hydrolysis parameters to product peptides with reducing scavenging activity on hydroxyl free radical of Fenton system from protein of PlatycepHalus indicus.First，Alcalase which hydrolysates showed higher scavenging activity than other four tested enzymes such as bromelain，trypsin，pepsin and papain，was choosed as the optimal enzyme for further study.Furthermore，the optimal hydrolysis parameters of Alcalase were determined by single factor experiment and response surface methodology.The results showed that the optimal enzymatic hydrolysis was enzyme substrate ratio of 3 000 U/gpro.，pH 9.0，temperature 40℃，duration time 180 min，solid and liquid ratio was 1∶30（g/mL）.Under these conditions，the scavenging activity on hydroxyl free radical was 89.49%.The IC50value of scavenging activity on hydroxyl radical was 0.58 mg/mL.So，the hydrolysates from protein of Platycephalus indicus has a good antioxidant activity，which can be used as natural antioxidants for further development and utilization.