Effect of cod (Gadus morhua L.) skin collagen hydrolysates on the stability of blueberry anthocyanin and key peptide identification

Anthocyanins are highly susceptible to the adverse environment and are prone to degradation. This study conducted a comprehensive investigation on the effect and underlying interaction of cod skin collagen hydrolysates (FCHs) and the corresponding peptide on stability properties of anthocyanins. It was discovered that the high degree hydrolysis of FCH had the most favorable anthocyanins protection effect and their interaction mainly through hydrophobic interaction and static quenching. Ultrafiltration-recovered fraction (Mw < 1 kDa) isolated from FCHs demonstrated a higher capacity for maintaining anthocyanins stability. A novel peptide (GEPGSNGPMG) was predicted and identified from this fraction using peptidomics and in silico screening approaches. Molecular docking and dynamics simulations further elucidated that their binding was accomplished through multiple interactions with amino acid residues, contributing to the complex stability. Through verification experiments, the novel peptide was capable of improving the stability and biological activity of anthocyanins to a much greater extent than native protein and hydrolysates. This research provided a possibility for the application on peptides as protectants for anthocyanins in food processing.