Valorization of chitin using a natural deep eutectic solvent for the development of active gelatin films

The development of active films is essential for extending food shelf life, minimizing spoilage, and reducing food waste. In this context, a novel approach was explored to create gelatin-based active films using choline chloride and citric acid natural deep eutectic solvent (DES) to dissolve chitin (Chi), valorized from fruit fly pupae and used as reinforcement. Films were manufactured by compression molding, varying Chi/DES amounts from 20, to 80 wt%. Since the films prepared with 40 wt% Chi/DES showed high UV protection and good mechanical performance for food packaging (tensile strength of 10 MPa and elongation at break of 31 %), these films were selected to prepare active films. In particular, to enhance the antioxidant properties of the films, red grape marc extract was incorporated into the film forming formulation. The bioactive-containing films demonstrated oxidation inhibition capacity and, thus, their potential to extend food shelf-life. • Food processing by-products were valorized to prepare food packaging films. • Films were prepared by compression, a more rapid process than solution casting. • Films showed high UV barrier to protect food from oxidation. • Films prepared with red grape marc extract showed antioxidant capacity to prevent food deterioration.