The main components of edible wrappers include a biopolymer solubilized in a solvent to form film casting solution and certain additives to improve functional characteristics of packaging as shown in Figure 1 (Teixeira-Costa & Andrade, 2012).
Biopolymers
Bio macromolecules including polysaccharides, proteins and lipids are extensively used as a biopolymer is formation of edible wrappers (Teixeira-Costa & Andrade, 2012). Edible packaging developed using natural renewable resources come under the category of bio based and biodegradable packaging. According to Chen et al. (2019), the selection of packaging materials is relying on food characteristics, intended properties and environmental factors to which wrapped product is expected to exposed during distribution and storage.
Velickova et al. (2015), classified edible wrappers into three categories on the basis of biopolymers; hydrocolloids, lipids, and composites. Hydrocolloids, are designed using hydrophilic biopolymers, including animal and plant proteins (caseins, gelatin, corn zein, peanut, soybean, and wheat) and polysaccharides (alginate, cellulose, chitosan, carrageenan, pectin, and starch), that assemble into complex framework. Lipids comprise essential oils, oils, resins, and waxes (Shit & Shah, 2014).
Polysaccharide and protein-based films and coating provides excellent gas barrier properties and mechanical strength however, allows moisture transfer (Bharti et al., 2020). Composites or multi-component films are developed to transcend these constraints by blending both lipids and hydrocolloids (Senturk Parreidt et al., 2018).