Development of Edible Packaging Films from Walnut, Mango, and Orange Peels: Effect of Plasticizers and Essential Oils

In this study, a biodegradable food packaging material was produced from dry walnut shells, mango peels, and orange peels. Effects of the plasticizer type, essential oils, and aloe vera gel addition on edible film properties were investigated. Edible films with 24 different compositions were prepared and applied to plum, grape, and apple slices. Orange peel-based edible films are the thinnest (0.1–0.2 mm). When lemon essential oil was added, the sorbitol-plasticized edible films had the lowest moisture content (8.38%). The minimum solubility was 7.83%, the minimum water vapor transmission rate was 0.0130 × 10–10 g/(s·m2), and the minimum swelling index was 26.8%. Fruits coated with walnut shell-based, sorbitol-plasticized edible film had the greatest effect on Staphylococcus aureus bacteria, and walnut shell-based, glycerol-based, and sorbitol-plasticized edible films were more effective than antibiotics against Escherichia coli bacteria. The fruits covered with orange and walnut shell-based edible film color were preserved. The weight loss of fruits coated with walnut shell-based, sorbitol-plasticized edible film and fruits coated with mango peel-based edible films was lower than that of uncoated fruits. It was concluded that all of the compositions studied are suitable for edible film production, and walnut shell-based, lemon essential oil-incorporated edible films gave the best results.