STUDIES ON SCAVENGING EFFECT ON HYDROXYL FREE RADICAL BY HYDROLYSATES FROM COMMON CARP(CYPRINUS CARPIO)PROTEIN

The purpose of this study was to optimize enzymatic hydrolysis parameters to product peptides with scavenging activity on hydroxyl free radical of Fenton system from common carp(Cyprinus carpio)protein.First,protamex whose hydrolysates showed higher scavenging activity than other four tested enzymes such as papain,pepsin,trypsin and flavourzyme,was choosed as the optimal enzyme for further study.Furthermore,the optimal hydrolysis parameters of protamex were determined by the response surface methodology.The results showed that the optimal enzymatic hydrolysis conditions was temperature 55 ℃,time duration 1.5 h,pH 6.5,enzyme concentration 250 U/g subsubstance,and substance/water ratio was 1:3.The degree of hydrolysis(DH) under this condition were 4.5 %.The molecular weight distribution of the hydrolysates was determinated by gel filtration chromatography on Sephadex G-15 column.Results showed that the molecular range of active fraction were 477 u to 1 058 u.