Tuning peptide self-assembly patterns in Tilapia scale gelatin hydrolysates through Cu2+ coordination: Characterization, identification and antioxidant evaluation

We investigated the self-assembly pattern of Tilapia scale gelatin hydrolysates through Cu 2+ coordination and their in vivo antioxidant properties by Cu 2+ -induced oxidative stress using the Caenorhabditis elegans . Two treatments (Alcalase®, Alc; and Alcalase® followed by Flavourzyme®, Alc+Flav) were used to prepare whole and ≤ 1 kDa hydrolysates. Upon Cu 2+ coordination, the fibrillation and surface hydrophobicity of all hydrolysates decreased, suggesting a degradation of β-sheet structures and the formation of amorphous aggregates. Rheological studies confirmed that the structural and mechanical properties of the resulting supramolecular assemblies are tunable after Cu 2+ coordination. Due to the Cu 2+ -chelating and self-assembly properties, peptides present in the Alc hydrolysate significantly reduced endogenous ROS levels through Cu 2+ coordination, thereby extending the lifespan of C. elegans . The results provide valuable insights into the influence of Cu 2+ coordination on the progression of peptide self-assembly and Cu 2+ -induced oxidation in worms and prospects for food self-assembled peptides in biomaterial and nutraceutical applications. • His and Met-containing peptides contributed to the peptide-Cu 2+ complex formation. • Cu 2+ coordination by gelatin peptides demonstrated tunable self-assembled pattern. • The self-assembly and antioxidant properties of peptide-Cu 2+ complex were improved. • Fish gelatin hydrolysate could reduce oxidation in C. elegans by Cu 2+ coordination.