ABSTRACT
122Edible coatings and films are defined like thin layers of edible materials applied on food products that play an important role on their conservation, distribution, and marketing. The use of edible coatings and films improves appearance, being an effective barrier to transmission of gases, solving problems of migration of moisture, oxygen, carbon dioxide, and aromas, and reducing maturation processes, thus extending storage time and quality of vegetables or fruits. Usually edible coatings and films are classified according to their structural material. They can be composed of hydrocolloids, which consist of polysaccharides or proteins, or hydrophobic compounds (e.g., lipids, waxes, and resins), forming a simple coating or film, or by a mixture of these components. In this latter case, they are known as “composite films” with the aim of taking advantage of the properties of each compound and the synergy between them. These materials do not intend to fully replace traditional packaging; instead, their use allows providing further properties and adding benefits by incorporating natural additives to be used for food preservation or enrichment. A diverse quantity of natural waxes, lipids, and resins has been investigated to improve quality and time of shelf life and/or add colors and functional compounds, among others, to foods.
