Food Protein‐Derived Zinc‐Binding Peptides: Isolation, Purification, and Biological Aspects

Zinc is the second most valuable microelement after iron, according to its abundance in the human body. Supplementation of this metal is not straightforward because of several factors like phytates and interference of other minerals during gastrointestinal digestion. For the last several years, intensive research has been developing new forms of zinc supplements based on zinc‐binding peptides from food products. Except for the advantages of supplementation, zinc‐peptide complexes are expected to be drug candidates against various diseases. Zinc supplementation can be improved by protein hydrolysates and peptides due to their zinc‐binding ability. They enhance zinc supplementation and contribute to preventing conditions leading to zinc deficiency that cause various diseases. Research on food‐derived zinc‐binding peptides is progressing in two directions: the isolation and identification of individual peptides (1) and the preparation of zinc complexes of protein hydrolysates (2). Both approaches are primarily aimed at developing effective mineral supplements, although some work on the second approach is also related to nutrition and therapy. Because zinc–protein hydrolysate complexes are nonstandardized mixtures of peptides, their biological activity mechanisms can be difficult to study. Therefore, it is important to focus more research on the biological activity of individual zinc‐binding complexes and their zinc complexes. This work reviewed recent advances in isolating and identifying zinc‐binding peptides from food sources, preparing protein hydrolysate–zinc complexes, and their biological activities. The established sequences of zinc‐binding peptides have been compiled into a table to review their amino‐acid composition and sequence. We also highlighted approaches for isolating and determining the zinc‐binding capacity of peptides in this class. The structural features of peptides affecting their zinc‐binding property were discussed in one section.