Strategies to Improve Hydrolysis Efficiency of Fish Skin Collagen: Study on ACE Inhibitory Activity and Fibroblast Proliferation Activity

Collagen peptides play a crucial role in promoting skin elasticity and enhancing joint health, with potential functions to be explored. Enzyme hydrolysis is crucial for the molecular weight and sequence of peptides, influencing the bio-activity. In this study, the angiotensin-converting enzyme (ACE) inhibitory activity and fibroblast proliferation activity of differentially molecular weight peptides derived from dual- or triple-enzyme hydrolysis were compared. Ultrafiltration membrane filtration was used to separate the hydrolyzed prepared collagen peptides into two components based on the molecular size. The results showed that the low-molecular-weight peptide fraction containing peptides with P at the C-terminal, such as KP, RP, and POGP, exhibited high ACE inhibitory activity. The low-molecular-weight peptide fraction obtained through triple-enzyme hydrolysis incorporating ginger protease exhibited the highest ACE inhibitory activity, with an IC50 3.1 mg/mL. In addition, the triple-enzyme hydrolyzed collagen peptides passing across membranes displayed higher migration rates and enhanced collagen synthesis capabilities, containing peptide sequences, such as POGP, POGA, and LPO, potentially promoting fibroblast proliferation. The results would provide practical guidance for the production of collagen peptides with high ACE inhibitory activity and fibroblast proliferation activity, in terms of enzyme processing and highly active peptide separation.