Hydrophobic peptides from oyster protein hydrolysates show better zinc-chelating ability

Hydrophilic and hydrophobic peptides were prepared from oyster protein hydrolysates, and zinc-chelating peptides were isolated and characterized. Compared with alcalase hydrolysates, the chelating ability of zinc ions of hydrophilic peptides and hydrophobic peptides was significantly improved, which were respectively 8.09 μg zinc/mg protein and 13.70 μg zinc/mg protein. The structural properties of hydrophobic peptides were identified using ultraviolet spectra, fluorescence spectra and fourier transform infrared spectroscopy, respectively. The results indicated that hydrophobic peptides could form complexes with zinc ions through covalent chelating reactions with carbonyl groups and coordination bonds with amino groups. In addition, molecular docking was performed on the sequences obtained from hydrophobic peptides by NanoLC-Q-TOF. The results indicated that aspartic acid, glutamic acid, and leucine acid of the peptides might play critical roles in the zinc-chelating ability. The findings could be used to make dietary zinc supplements.