Discovery and molecular insights of a novel pea-derived antioxidant peptide: From quantum chemical insights to oxidative stability of walnut oil

Abstract

This study identified novel antioxidant peptides from defeasated pea protein and characterized their molecular properties and protective effects in a lipid system. Following ultrafiltration, Sephadex G-15 purification, Nano LC–MS/MS identification, and in silico screening, five unreported peptides (F1–F5) were selected for evaluation. Antioxidant activities varied across DPPH, ABTS, and hydroxyl radical assays, reflecting sequence- and assay-specific differences. Integrated experimental and computational analyses identified GIPYWTY (F1) as the lead peptide. Molecular docking revealed favorable F1–Keap1 interactions, while quantum-chemical analyses highlighted radical-reactive regions. A 100 ns molecular dynamics simulation confirmed complex stability, with an MM/PBSA binding free energy of −36.73 kJ/mol. In walnut oil, 0.075% (w/w) F1 supplementation attenuated increases in peroxide and acid values and partially preserved antioxidant capacity during 10 d of accelerated oxidation at 60 °C. These findings establish GIPYWTY as a promising pea-derived antioxidant peptide for mitigating oxidative deterioration in lipid-rich foods.