Purification and characterization of three antioxidant peptides from protein hydrolyzate of croceine croaker (Pseudosciaena crocea) muscle.

Three antioxidant peptides were purified from protein hydrolysate of croceine croaker (Pseudosciaena crocea) muscle prepared using pepsin and alcalase, and identified as Tyr-Leu-Met-Ser-Arg (PC-1), Val-Leu-Tyr-Glu-Glu (PC-2), and Met-Ile-Leu-Met-Arg (PC-3) with molecular weights of 651.77, 668.82, and 662.92Da, respectively. PC-1 exhibited the highest scavenging activities on DPPH (EC50 1.35mg/ml), superoxide (EC50 0.450mg/ml), and ABTS (EC50 0.312mg/ml) radicals, but PC-2 exhibited the strongest hydroxyl radical scavenging activity (EC50 0.353mg/ml) among the three peptides. PC-1 also showed effective inhibition on lipid peroxidation in the model system. The good activities of isolated peptides might be benefit from the smaller size and hydrophobic and/or aromatic amino acids within their sequences.