Enzymatic hydrolysis affected the antioxidant activity and traceability identification of porcine collagen peptides

Enzyme selection critically impacts porcine collagen peptide properties and identification. In this study, seven enzymes, namely alkaline protease, neutral protease, papain, compound protease, flavourzyme, pepsin, and trypsin, were used to hydrolyze porcine gelatin, significantly altering peptide characteristics. Expasy Peptide Cutter predicted alkaline protease had the most cleavage sites. Its hydrolysate showed the highest hydrolysis, the smallest molecular weight, and better radical scavenging activity. Neutral protease hydrolysate exhibited the best Fe²⁺ chelation. By HPLC-MS/MS analysis against the theoretical peptide database, 19, 10, 56, 10, 10, 210, and 14 characteristic peptides were detected in porcine gelatin hydrolyzed by alkaline protease, neutral protease, papain, compound protease, flavourzyme, pepsin, and trypsin, respectively. Seven stable and common characteristic peptides were identified. Comparing different processing conditions, two stable characteristic peptides were retained to the end, which were ³²⁸GI*PGPAGAAGATGAR³⁴² and ⁴⁵¹GF*PGS*PGNVGPAGK⁴⁶⁴. These stable characteristic peptides therefore serve as key markers for identifying porcine collagen peptides.