Edible coatings to improve food quality and safety

ZARITZKY NOEMI

Food Engineering Interfaces

Springer

Lugar: New yorkUSA; Año: 2010;

Edible films and coatings are produced from edible biopolymers and food-grade additives. Film-forming biopolymers can be proteins, polysaccharides or lipids. Plasticizers and other additives are combined with the film-forming biopolymers to modify the physical properties or functionality of films. The film-forming mechanisms of biopolymers include intermolecular forces such as covalent bonds (e.g., disulfide bonds and cross-linking) and/ or electrostatic, hydrophobic or ionic interactions.Edible coatings can extend the shelf-life of foods by functioning as solute, gas, and water vapor barriers. Moreover, these films can be used as a host for additives in the conservation of the properties of the product or simply in order to improve its appearance.Edible coatings can improve the quality of fresh, frozen, and processed meat, poultry, and seafood products by retarding moisture loss, reducing lipid oxidation and discoloration, enhancing product appearance in retail packages by eliminating dripping, functioning as carriers of food additives such as antimicrobial and antioxidant agents.The success of an edible coating for meeting the specific needs of fresh and minimally processed fruits and vegetables strongly depends on its barrier property to moisture, oxygen, and carbon dioxide, which in turn depends on the chemical composition and structure of the coating-forming polymers, the characteristics of the product, and the storage conditions. Edible coatings contribute to preserve the most important quality attributes contributing to the marketability of fresh and minimally processed fruits and vegetables: appearance, color, texture, flavor, nutritional value, and microbial safety.Besides, methylcellulose and hydroxypropyl cellulose coatings are used to reduce oil uptake during frying.Edible films can serve as carriers for a wide range of food additives, including  flavoring agents, antioxidants, vitamins, and colorants. When antimicrobial agents such as benzoic acid, sorbic acid, propionic acid, lactic acid, nisin, and lysozyme have been incorporated into edible films, such films retarded surface growth of bacteria, yeasts, and molds on a wide range of products, including meats and cheeses.Various antimicrobial edible films have been developed to minimize growth of spoilage and pathogenic microorganisms, including Listeria monocytogenes, which may contaminate the surface of cooked ready-to-eat foods after processing.In this presentation application of edible coatings to different fruits and vegetables, and their use in fried products are discussed in detail, as well as the inclusion of antimicrobial agents to prolong storage life of foods.