Characterization of edible coatings based on ripe Prata banana peel flour

To increase the useful life of food products, edible coatings were developed using flour made from ripe Prata banana (Musa spp.) peels and cornstarch, a low coast, water soluble, biodegradable natural polymer that facilitated the handling of films, and characterized as to their physical, mechanical, and barrier properties. The films were prepared from the banana peel flour by the casting technique, varying the cornstarch concentration (33.3-66.6% w/w) and the heating time (30-60 min). The effects of these two variables on the properties were evaluated by response surface methodology. For the physical properties, it was found that the thickness (0.059-0.085 mm) was influenced by increasing the cornstarch concentration. The chroma remained uniform with different cornstarch concentration and heating time. Whereas, the luminosity had an inverse behavior to the heating time. The solubility of the films were not related to the study variables. As for the barrier properties, water vapor permeability (8.85-14.82 x 10(-5)g/m.s.Pa) of the films was influenced by the cornstarch concentration. The mechanical behavior presented low tensile strength values (0.14-0.70 MPa). The elastic modulus (3.00-33.08 MPa) had a direct relationship with the cornstarch concentration and heating time, but the elongation rates (9.84-20.16%) were influenced only by the heating time. The puncture test (5.56-20.01 MPa) was influenced by the variables, and the puncture deformation (9.05-30.13%) by the variables and their interaction. This study demonstrates that ripe Prata banana peel flour is a promising material to be used as a raw material to develop edible films.