Development and application of edible coatings in minimally processed fruit

Abstract

Desarrollo y aplicación de recubrimientos comestibles en frutas mínimamente procesadasThe consumer's interest to purchase safe, nutritious, minimally processed, and healthy food has increased consumption of various fruits and vegetables. Generally, the quality of fruits depends on nutritional, microbiological and organoleptic properties, all of which are exposed to dynamic changes during harvesting, storage, and marketing. These changes are mainly due to the interactions between the fruits and its surroundings or migration among different inner components, which can result in loss of moisture and some volatile compounds (1, 2).The edible coatings technique is a good alternative to control some of these factors, it includes thin layers of edible materials formed directly onto the surface of the food that can be eaten as part of the whole product. Although edible coatings have been used for centuries to prevent moisture migration or to create a shiny surface for esthetic purposes; recently, there is considerable interest and more research on this application, driven to minimize the environmental impact of non-biodegradable materials and the increasing demand for minimally-processed foods (3, 4).Edible coatings are made from various materials, such as polysaccharides (starch, cellulose, pectin, alginate), proteins (gelatin, casein, albumins), and lipids (beeswax, fatty acids). Usually, mixtures of these materials are used to take advantage of each constituent. Polysaccharides and proteins based edible coatings could form cohesive molecular networks by strong interactions between molecules, which provide good mechanical properties and barrier to gases, O 2 and CO 2 (5). However; generally, these are polar polymers, resulting in a matrix with low cohesion and high water vapor permeability. Different alternatives have been used to improve this property, including the addition of hydrophobic compounds as lipids, modifying the polymer network and addition of nanocomposites (6).New matrices have been evaluated for coating fruit and minimally processed products; for instance, aloe vera mucilage has important biological, antimicrobial and antiviral properties. Aloe vera coatings have shown the capacity of reducing moisture loss, respiration rates, growth of microorganisms and oxidative browning in various fruits, such as strawberries, papaya and mango (7). Applying aloe vera coating on minimally processed mango (Tommy Atkins) has shown outstanding results, increasing shelf-life up to three days (8). Likewise, in Kiwi it has proved more efficient than other coating-forming matrices (alginate and chitosan), maintaining the sensory attributes, especially texture (7).The coating process involves a humectation (wettability) of the fruit coated by the suspension, a possible penetration of the suspension into the fruit, followed by a possible adhesion between the suspension and the fruit. Wettability stage is important, because it is a measure of compatibility between the suspension and the fruit; it affects the coating's time an...

Analysis of Alternative Shelf Life-Extending Protocols and Their Effect on the Preservation of Seafood Products

“…Because of their popularity as a promising innovation, numerous antimicrobial components have been incorporated into these edible coatings with positive results [10,53,54]. Edible coatings and biodegradable films usually consist of a solution of lipids and/or polymers, such as proteins and polysaccharides, with antimicrobial activity, such as chitosan, or capable of forming a structural matrix operating as a carrier of antimicrobial compounds, such as sodium alginate and carboxymethylcellulose [10,50,55]. Polysaccharide-based films and coatings, such as those consisting of cellulose, chitosan, and alginate, benefit from the abundance of such compounds in nature.…”