Mineral-element-chelating activity of food-derived peptides: influencing factors and enhancement strategies

Mineral elements including calcium, iron, and zinc play crucial roles in human health. Their deficiency causes public health risk globally. Commercial mineral supplements have limitations; therefore, alternatives with better solubility, bioavailability, and safety are needed. Chelates of food-derived peptides and mineral elements exhibit advantages in terms of stability, absorption rate, and safety. However, low binding efficiency limits their application. Extensive studies have focused on understanding and enhancing the chelating activity of food-derived peptides with mineral elements. This includes obtaining peptides with high chelating activity, elucidating interaction mechanisms, optimizing chelation conditions, and developing techniques to enhance the chelating activity. This review provides a comprehensive theoretical basis for the development and utilization of food-derived peptide-mineral element chelates in the food industry. Efforts to address the challenge of low binding rates between peptides and mineral elements have yielded promising results. Optimization of peptide sources, enzymatic hydrolysis processes, and purification schemes have helped in obtaining peptides with high chelating activity. The understanding of interaction mechanisms has been enhanced through advanced separation techniques and molecular simulation calculations. Optimizing chelation process conditions, including pH and temperature, can help in achieving high binding rates. Methods including phosphorylation modification and ultrasonic treatment can enhance the chelating activity.

Screening, separation and identification of metal-chelating peptides for nutritional, cosmetics and pharmaceutical applications

Metal-chelating peptides, which form metal-peptide coordination complexes with various metal ions, can be used as biofunctional ingredients notably to enhance human health and prevent diseases. This review aims to discuss recent insights into food-derived metal-chelating peptides, the strategies set up for their discovery, their study, and identification. After understanding the overall properties of metal-chelating peptides, their production from food-derived protein sources and their potential applications will be discussed, particularly in nutritional, cosmetics and pharmaceutical fields. In addition, the review provides an overview of the last decades of progress in discovering food-derived metal-chelating peptides, addressing several screening, separation and identification methodologies. Furthermore, it emphasizes the methods used to assess peptide-metal interaction, allowing for better understanding of chemical and thermodynamic parameters associated with the formation of peptide-metal coordination complexes, as well as the specific amino acid residues that play important roles in the metal ion coordination.

The Hypopigmentation Mechanism of Tyrosinase Inhibitory Peptides Derived from Food Proteins: An Overview

Skin hyperpigmentation resulting from excessive tyrosinase expression has long been a problem for beauty lovers, which has not yet been completely solved. Although researchers are working on finding effective tyrosinase inhibitors, most of them are restricted, due to cell mutation and cytotoxicity. Therefore, functional foods are developing rapidly for their good biocompatibility. Food-derived peptides have been proven to display excellent anti-tyrosinase activity, and the mechanisms involved mainly include inhibition of oxidation, occupation of tyrosinase’s bioactive site and regulation of related gene expression. For anti-oxidation, peptides can interrupt the oxidative reactions catalyzed by tyrosinase or activate an enzyme system, including SOD, CAT, and GSH-Px to scavenge free radicals that stimulate tyrosinase. In addition, researchers predict that peptides probably occupy the site of the substrate by chelating with copper ions or combining with surrounding amino acid residues, ultimately inhibiting the catalytic activity of tyrosinase. More importantly, peptides reduce the tyrosinase expression content, primarily through the cAMP/PKA/CREB pathway, with PI3K/AKT/GSK3β, MEK/ERK/MITF and p38 MAPK/CREB/MITF as side pathways. The objective of this overview is to recap three main mechanisms for peptides to inhibit tyrosinase and the emerging bioinformatic technologies used in developing new inhibitors.