Application of Sericin in Food Industries and Coating of Fruits and Vegetables

The cocoon formed by the silkworm Bombyx mori contains 25–30% sericin and 70–75% fibroin proteins. Sericin is a natural silk globular protein that is typically eliminated as a biological waste material after separating the fibroin from the silk cocoon to make silk products. The sericin protein is widely employed as a coating material as well as in pharmaceutical, nutraceutical, cosmetic, and therapeutic applications due to its antioxidant, antibacterial, biocompatible, and biodegradable nature. The use of sericin in edible coatings or films not only provides anti-browning, antibacterial, and antioxidant qualities but also improves the nutritional properties of the food product. Thus, using sericin in food applications provides various benefits and expands its scope in the food sector. Furthermore, fruits are an important part of a person’s daily diet. Fruit and vegetable postharvest losses range from 15 to 40% due to inappropriate preservation/storage and marketing. Because fruits are perishable in nature, deterioration happens quickly, and different coating materials such as wax, cellulose, and starch are employed to extend the shelf life of the fruit, which are either non-digestive or primary goods. However, sericin, a silk protein that is often eliminated as waste in the sericulture and textile industries, has the potential to be used as a coating material. Approximately 50,000 tons of sericin are typically wasted as reeling waste. Sericin from cocoon reeling waste provides a sustainable and cheaper supply of protein sources and can serve as fat-free edible coating material. It is highly desired to choose coating materials that are easily digestible and have no negative effects on human health. Sericin can be used as a coating material to prevent fruit deterioration by increasing shelf life. As a result, using sericin in food packaging and extending the shelf life of fruits are both environmentally beneficial and commercially viable. The features of sericin materials and their possible applications in food-sector enterprises are addressed in-depth in this chapter.