*4.3. Applications of Starch*

Starch is often compounded with other edible materials to fabricate edible films or coatings, which are widely used in different food packagings, such as fruits, vegetables, meat, seafood, confectioneries, cakes, and pastries to block the migration of oxygen and grease and help improve the appearance, texture, and processing performance of foods (Table 4). Go et al. [175] added rosehip extracts to rye starch matrix to cast edible composite films and applied them in chicken breast packaging. The flexibility, optical properties, and antioxidant activity of the composite films were improved, and the highest ABTS and DPPH radical scavenging activities were observed in films containing 1.0% extracts (96.87% and 80.22%, respectively). Moreover, chicken breasts packaged with these films had lower peroxide and thiobarbituric acid reactive substance values than those packaged with original rye starch film, as well as the non-packaged control, suggesting that the edible composite films could effectively inhibit lipid oxidation and prolong its shelf life. Likewise, incorporating maqui berry extract [181], carvacrol, and chitosan [186] in starch-based edible composites (e.g., edible films and coatings) retarded lipid oxidation in fish, ham, and other foods, inhibited the growth of foodborne pathogens, and extended the shelf life of foods. Qin et al. [176] added *Lycium ruthenicum* Murr anthocyanins to cassava starch to manufacture a freshness indicator film with both intelligent pH sensitivity and edibility for pork packaging. The results showed that the barrier ability, tensile strength, and antioxidant activity of the composite film were improved by hydrogen bond interactions between anthocyanins and starch chains. Moreover, this composite film achieved real-time and visual monitoring of pork freshness based on its color change with pork quality during storage.

Furthermore, a significant difference from other polysaccharides is that original starch exposed to shear and high temperature (supplemented with water and processing aids) could be converted into thermoplastic starch-based materials, and then various starchbased edible packaging containers (e.g., film, cup, tray, and plate) can be obtained through extrusion, compression, or injection molding (Figure 3) [17,140,187,188].

#### *4.4. Applications of Chitosan*

Currently, chitosan-based edible packaging (as a film and coating) has been widely used in the packaging of fruits (e.g., strawberries, apples, kiwi, and grapes), vegetables (e.g., tomato, pepper, and eggplant), meats, and nuts to retain food quality and prolong their shelf life (Table 4) [56,171,177,189–192]. These edible packages mainly achieve food preservation by reducing the transpiration rate, delaying browning or lipid oxidation, and inhibiting the growth of spoilage microorganisms.

Divya et al. [56] coated chitosan nanoparticle solutions on the surfaces of tomatoes, chilies, and brinjals using the dip-coating method (Figure 3). The edible coatings had a good inhibitory effect on *Rhizoctonia solani*, *Fusarium oxysporum*, *Collectotrichum acutatum*, and *Phytophthora infestans* during 5 days of storage, had significant antioxidant activity, reduced the weight loss of these vegetables, and prolonged their shelf lives. Perdones et al. [189] applied chitosan-lemon essential oil dip-coatings to strawberry preservation. The results indicated that these edible coatings could control strawberry fungal decay during storage

and affect the metabolic pathways and volatile profile by promoting the formation of esters and dimethyl furfural and incorporating terpenes into the fruit volatiles in a short time. Likewise, Dini et al. [177] packaged beef loins in chitosan-based edible films containing cumin essential oil nanoemulsions supplemented with irradiation treatment. The results showed that the edible composite films could withstand low-dose gamma irradiation at 2.5 kGy, while inhibiting the growth of *L. monocytogenes*, *E. coli* O157:H7, and *Salmonella typhimurium* in beef loins during the 21/days refrigerated storage, and slowed down the increasing level of total volatile basic nitrogen and pH value of beef, thus effectively enhancing the microbiological safety, quality, and storage life.
