Novel antioxidative peptides from the protein hydrolysate of oysters (Crassostrea talienwhanensis)

The critical reaction temperature, pH, hydrolysis time and enzyme-to-substrate (E/S) ratio were determined for the optimum hydrolysis with subtilisin, and the E/S ratio was found to be the most critical reaction condition. The amino acid sequences of the peptides (518 and 440 Da) were proline-valine-methionine-glycine-aspartic acid (PVMGA) and glutamine-histidine-glycine-valine (QHGV), respectively. These two novel peptides exhibited high antioxidative actions based on their hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities.