Preparation and in vitro antioxidant activity of enzymatic hydrolysates from oyster (Crassostrea talienwhannensis) meat

Oyster is an abundant resource from ocean, which contains high content of protein. In the present study, oyster (Crassostrea talienwhannensis) meat was digested with three proteases including papain, neutrase and alcalase respectively and the derived hydrolysates were fractionated using a series of ultrafiltration membranes (molecular weight cut-offs of 10, 5, 3 and 1 kDa). The resultant peptide fractions were evaluated for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and reducing power assay. Results indicated that oyster meat hydrolysates (OMHs) possessed DPPH radical scavenging capacity and reducing power in a dose-dependent manner. The fractions below 1 kDa showed the strongest overall antioxidant activity. The present study demonstrated that the antioxidant potent of OMHs was strongly related to their concentration, size and amino acid composition.