Peptides and protein hydrolysates as food preservatives and bioactive components of edible films and coatings - A review

Background: The consumer demand for food that is minimally processed and that does not include artificial additives makes it necessary to look for new natural sources of preservatives and active packaging that extends the shelf-life of food products. Protein hydrolysates and biologically active peptides isolated from food proteins, due to their antioxidant and antimicrobial activity, can be used as natural food preservatives. In addition, it is possible to include them in packaging materials as active ingredients. Scope and approach: In this paper, the possibilities of using protein hydrolysates and biopeptides are characterized as ingredients extending the shelf-life of food by adding them directly to food products, or as biodegradable ingredients of edible active packaging. The full implementation of bioactive peptides and protein hydrolysate is postponed by some challenges such as their low chemical stability, bitter taste and short-term effectiveness. Encapsulation, which is also discussed in this work, could help overcome these limitations. Key findings and conclusions: It has been found that protein hydrolysates and their biopeptides directly added to food products, already in small doses, mostly inhibit fat oxidation and inhibit the growth of microorganisms. Edible active packaging materials with bioactive peptides and protein hydrolysates have shown effectiveness in inhibiting pathogenic microorganisms and lipid oxidation, improving food safety. In several studies, significant changes have been indicated in the mechanical properties and surface morphology of films with the addition of protein hydrolysate and peptides. Nonetheless, the direction of these changes depends on the type of incorporated protein hydrolysates. Protein hydrolysates and biologically active peptides are a promising alternative to synthetic preservatives and active ingredients of biopolymer films. However, further research should be carried out, focusing on the search for new sources of these compounds and assessing their safety.