Improving tyrosinase inhibitory activity of grass carp fish scale gelatin hydrolysate by gastrointestinal digestion: Purification, identification and action mechanism

Biologically active peptides with tyrosinase inhibitory activity may be important raw materials in the field of whitening foods. Gastrointestinal digestion was employed to obtain components with higher tyrosinase inhibitory activity from the grass carp fish scale gelatin hydrolysates. The results revealed that the product had stronger tyrosinase inhibitory activity after gastrointestinal digestion than before. The digested products were screened using bioaffinity ultrafiltration for tyrosinase inhibitory activity for the first time, yielding 6 peptides. As a reversible competitive inhibitor, FTGML showed the highest IC50 value of 1.89 mmol/L. The main forces between FTGML and tyrosinase was dominated by hydrogen bonding and hydrophobic interaction. Zebrafish models for skin whitening and lightning were established respectively to verify the effect of FTGML in vivo, and it was discovered that FTGML concentrations of 125 mu g/mL and 62.5 mu g/mL had the best whitening and lightning effects, respectively.

Automated summary

Biologically active peptides with tyrosinase inhibitory activity from grass carp fish scale gelatin hydrolysates have been obtained and tested for their efficacy in whitening foods. The digested products showed stronger tyrosinase inhibitory activity compared to the original hydrolysates. Six peptides with tyrosinase inhibitory activity were identified using bioaffinity ultrafiltration, with FTGML showing the highest inhibitory activity. The interaction between FTGML and tyrosinase was mainly driven by hydrogen bonding and hydrophobic interaction. In vivo studies using zebrafish models confirmed the whitening and lightning effects of FTGML at specific concentrations.