Films based on gelatin and native starches from wheat, sorghum, potato and rice were produced separately and characterized as to their physical-chemical (water solubility and water vapor permeability), physical (thickness and opacity) and mechanical (resistance to traction and percentage elongation at rupture) properties. The same solutions were prepared and applied to Crimson grapes for sensory evaluation and determination of weight loss over 22 days. The sorghum and rice coatings were the most efficient in their extending shelf life (a ten day increase). However, with respect to sensory attributes, the grapes with the rice coating did not show a statistical difference when compared to the control, which presented the lowest scores for global appearance purchase. The sorghum coating presented a water vapor permeability of 5.40 g.mm.m-2.d.kPa, resistance to traction of 85.89 MPa, stretching of 6.61% and opacity of 40%. This film did not present the best characterization values, but was the best coating option. In the sensory evaluation, the coated grapes had a better or similar acceptance, when compared to the control, as to global appearance, shine, color and purchase. With respect to the eating characteristics of the grapes, none of the coatings significantly influenced aroma, flavor and texture, and were accepted by the consumers in every parameter.
edible film; edible coating; native starch; gelatin; grape
