Functionality of protein-Based edible coating- review

Consumer demand for convenience package and consumption, safe microbiologically, longer product shelf-life and effect of packaging material on environment is forcing food processor and researcher to develop new technique in food processing, cooking, handling, and packaging strategies. Most of ready-to- eat foods are exposed to post-process contamination, leading to spoilage and reduced shelf-life. Biopolymers extracted from biomass, synthesized from bio-derived monomers or produced directly by microorganisms with the advantages of biodegradability, process ability, no pollution to food, abundant and renewable have become the leading food packaging materials. Furthermore, the raw materials to produce biopolymers are low-cost, some coming even from by-product of agriculture and fish processing waste. Proteins-based edible films can be incorporated into foods to impart nutritive value and functional properties. The materials to develop protein-based coatings and packaging films can be divided into two classes: plant proteins and animal proteins. Proteins referred in this review are broadly classified under cereal, milk, oilseeds, collagen and gelatin based. Proteins-based edible coating has excellent gas barrier properties and good mechanical properties. However, the hydrophilicity nature of proteins makes the protein-based films poor water barrier properties. The application of plasticizers and treatments can improve the protein-based films and coatings. The addition of physical and chemical active compounds into protein-based films can increase the functional properties which can inhibit or delay the growth of microorganisms and the oxidation of lipids thereby increase its shelf-life. The review summarized the advances and research about the functional properties protein-based films and coatings in food packaging with examples.