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 Cu²⁺ coordination and their in vivo antioxidant properties by Cu²⁺-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 Cu²⁺ 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 Cu²⁺ coordination. Due to the Cu²⁺-chelating and self-assembly properties, peptides present in the Alc hydrolysate significantly reduced endogenous ROS levels through Cu²⁺ coordination, thereby extending the lifespan of C. elegans. The results provide valuable insights into the influence of Cu²⁺ coordination on the progression of peptide self-assembly and Cu²⁺-induced oxidation in worms and prospects for food self-assembled peptides in biomaterial and nutraceutical applications.