Abstract: Silk sericin was prepared from silkworm Bombyx mori and silk sericin hydrolysates(SSH) were obtained by hydrolysis of silk sericin with six proteases.It’s ability to scavenge 1,1-diphenyl-2-picrylhydrazyl(DPPH) radicals was determined.The antioxidant activities of the SSH,including lipid peroxidation in linoleic acid system,reducing power and ferrous ion chelating ability,were evaluated.The results showed that different protease hydrolysates possessed different ability to quench the ABTS cation radicals and DPPH radicals.Among those tested,Alcalase hydrolysate exhibits the highest scavenging activity than other protease(p<0.05).The results also showed that six SSH had potent antioxidative activity on peroxidation of linoleic acid.Alcalase hydrolysate exerted the highest inhibition than other protease(p<0.05).The reducing power and ferrous ion chelating ability of six SSH were significant.These results indicated that six SSH from silkworm Bombyx mori were natural antioxidant with potent antioxidative activity.

Key words: silk sericin, proteases, hydrolysates, antioxidant activities, linoleic acid