Chitosan-Based Edible Films Produced from Crab-Uçá (Ucides cordatus) Waste: Physicochemical, Mechanical and Antimicrobial Properties

The fish industry generates waste that negatively impacts the environment. Providing solutions that minimise this impact has become an interesting challenge in the last decades. Crab residues contain chitin in their chemical composition, which upon deacetylation affords chitosan, a polymer with potential applications in films and/or edible coatings. The present work aimed at the production and characterisation of chitosan films from crab-uçá (Ucides cordatus) residues. The employed methodology led to the production of chitosan with a deacetylation degree of 92%. Several films were formulated using three concentrations of chitosan (1.5%, 2.0%, and 2.5%) and glycerol (0.30%, 0.45%, and 0.60%). In general, the edible films composed of chitosan from crab-uçá and glycerol presented good optical and mechanical properties, as well as satisfactory WVP (Water Vapor Permeability) and solubility values. Chitosan filmogenic solutions at different concentrations showed antimicrobial activity against all the standard bacterial strains studied. The film with 1.5% chitosan and 0.6% glycerol has better properties for food application. The produced films have great potential for the development of future biodegradable packaging materials.