Enrichment of antioxidant peptides by interfacial modification of oat polypeptides induced by zinc ions.

The pursuit of methods to enhance the purity of food-sourced bioactive peptides continues to pose significant challenges. This study introduces an innovative approach to enrich antioxidant peptides by using zinc ion coordination to augment the foaming capabilities of oat peptides. The resulting antioxidant peptide fraction (AF) accounted for 18 % of the oat globulin hydrolysates, with a significant increase (22-47 %) in scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), OH, and O2- radicals. Proteomics identified 479 peptide segments within AF, and the HipHop analysis further identified 340 antioxidant peptides. Notably, the larger peptides (7-23 amino acids) were the primary contributors to the antioxidant activity, featuring key pharmacophores, i.e., charge centers, hydrophobic centers, and hydrogen bond acceptors. The AF and its key monomers (DDTKTWPEDL, YSTDPANPTKSA, NKREQQSGNNIF, and QVGQSPQYQEG) exhibited potent inhibitory effects on tyrosinase (IC50, 18.60-46.20 μg/mL) and provided strong inhibition against lipid oxidation, indicating great potential for applications in health supplements and food preservation.