Biopreservation of pre-processed fresh fish by bio-based coatings: A single strategy with multiple benefits towards waste prevention

The demand for pre-processed fresh fishery products is growing due to their convenience for subsequent processing and cooking. However, when improperly stored, the combined impacts of microbial deterioration and chemical reactions render them inedible, leading to significant food waste. To tackle this issue, several approaches have been proposed, among which bio-based edible coating provides a promising solution with a green approach. Edible coatings are formed of bio-based polymers, particularly using macromolecules such as proteins and polysaccharides that are biodegradable, edible, and can serve as carriers for naturally sourced active agents. Coatings made from a variety of proteins and polysaccharides with the main focus on gelatin and chitosan to preserve pre-processed fish products are discussed in this review along with their properties from the microbial, physicochemical, and sensory perspectives. Coating carriers and composite natural preservatives as well as formula optimization and investigation of coating mechanisms, challenges, and potential research prospects have been further reviewed. Overall, edible coatings with active substances can be used to efficiently preserve freshly pre-processed fish. The underlying mechanisms are multiple, and the applications were mainly for preventing or reducing moisture loss and purge accumulation, postponing microbial spoilage, and restricting the growth of pathogenic microorganisms, slowing and/or inhibiting lipid, protein, and pigment oxidation, and extending the shelf-life along with improving sensory properties. Edible coatings are viewed as ecologically friendly and sustainable packaging alternatives for the preservation of pre-processed fish products.