Preparation and Characterization of Antimicrobial Packaging Films from Cricket Chitosan Enriched with Schisandra Chinensis Extract

Sammanfattning: Chitosan films for food packaging applications were prepared from shrimp and cricket chitosan, enriched with Schisandra chinensis extract. Physicochemical and antibacterial properties of the films were studied and compared with references studying similar chitosan films. Chitosan is a biodegradable polymer, mostly harvested from shells of crustaceans, which has been studied for packaging applications, as it can improve shelf life of food products, especially when enriched with antibacterial and antioxidant compounds. The addition of these substances, such as herbal extracts, influences the physicochemical properties of the film, which are important parameters for characterization of packaging material, as it is necessary to assess its ability to fulfill the necessary packaging requirements. It was shown that insect chitosan film has superior or equivalent physicochemical properties and superior antimicrobial properties to shrimp chitosan. Addition of S. chinensis extract improved antibacterial and water vapor permeability barrier properties, however resistance to water solubility decreased. The originality of the work lies in the use of extract from S. chinensis, which has not been used in films before and which demonstrated antibacterial effect on Gram-positive bacteria, and in harvesting chitosan from crickets (Gryllus bimaculatus) as an alternative chitosan source, as all previous experiments with chitosan films have been done with crustacean chitosan. Moreover, during the extraction of insect chitosan, novel and effective decolorization method was discovered.