Biodegradable Films Based on Gelatin and Papaya Peel Microparticles with Antioxidant Properties

Biodegradable and bioactive films were prepared using gelatin from nutraceutical capsules wastes and natural antioxidants present in papaya peel. These films are intended to be an alternative to synthetic polyethylene packages in food preservation. Papaya peel was incorporated in the gelatin matrix as macroparticulate powder and in the form of microparticles, in different concentrations (2.5, 5, and 7.5%). The papaya peel powder microparticles were produced by spray drying with gelatin as wall material. The results indicated that microparticles of papaya peel powder originated a more continuous film matrix increasing the tensile strength and Young's modulus. Films with 5 and 7.5% papaya peel macroparticulate powder showed the highest antioxidant activity with values of 0.94 and 1.44 mu mol Trolox equivalents (TE)/g dried film, respectively, when compared to films with microparticles (0.63 and 0.84 mu mol TE/g dried film). When applied as packaging material for lard, the films with microparticles (7.5%) were the most efficient as active barriers (higher antioxidant activity), as a lower content of peroxides (3.47 mEq/kg) quantified after 22 days. The addition of natural antioxidants through papaya peel microparticles is a promising strategy for the development of environmentally friendly packaging of food products with high-fat content and susceptible to oxidation.