A review article titled 'Recent applications of biopolymers derived from fish industrial waste in food packaging' was published in Polymers by Francesca Rionetto from the Department of Innovative Engineering, University of Salento, summarizing the Recent advances in the valorization of fish industry waste and the potential to reuse these by-products in a circular economy approach for the preparation of bioplastics for food packaging.
Application of chitosan in food packaging
Chitin, the second most abundant biopolymer in nature after cellulose, is a linear polymer, a polysaccharide, located in the cell walls of fungi and in the exoskeletons of plankton, crustaceans, and insects, in order to crystallize microscopically. In the form of fibers, these organisms produce about 100 billion tons of chitin each year.
The biocompatibility, nontoxicity, and biofunctional properties of chitin and chitosan biopolymers make them potentially suitable for food packaging applications. In particular, chitosan biopolymers extracted from shrimp are pre-determined as generally recognized as safe (GRAS). On the other hand, chitosan is much cheaper compared to other biopolymers. Nonetheless, the excellent properties of chitosan make it more suitable for food packaging applications. For example, extending the shelf life of bread has been successfully proposed as it has been shown to delay starch retrogradation by preventing microbial growth.
Tyliszczak et al. demonstrated that chitosan films can also preserve strawberries. Furthermore, Zakaria et al. demonstrated that chitosan films inhibited changes in vegetable physical properties. Chitosan can also be used to produce food wrappers coated with it, thereby retarding the growth of microorganisms. The strategies to improve the performance of chitosan films for food packaging are almost the same as those adopted for isinglass films. In fact, the development of polymer blends represents an effective approach to improve mechanical properties and reduce water solubility and water vapor permeability. Several polysaccharides have been added to chitosan for the production of hybrid films with enhanced final properties for food applications. Among them, starch is one of the most common polysaccharides proposed for the production of chitosan-based biofilms due to its low cost, wide availability and biodegradability.
Chitosan/starch films showed reduced bacterial adhesion, excellent antioxidant activity, and increased water vapor barrier properties on packaging, thus demonstrating their potential applicability for specific applications. Several scientists investigated the possibility of preparing cellulose/chitosan mixtures to improve the mechanical properties of pure chitosan.
