Edible films have been studied as potential substitutes for conventional plastics in food packaging. Their
development provides a new alternative for the application of hydrocolloids, following global trends of
environmental preservation. Taking this into account, the aim of this study was to develop and evaluate
physicochemical properties (thickness, solubility in water and acid, water vapor permeability, opacity,
tensile strength and elongation at break) of composite
films based on corn starch (native, modified waxy
or waxy) and gelatin, plasticized with glycerol or sorbitol. After this initial screening, the formulation
presenting the physicochemical properties more appropriate was applied as an edible composite coating
onto Red Crimson grapes to extend the shelf-life. The addition of gelatin significantly increased
mechanical strength, solubility in water, permeability to water vapor, and thickness of the biofilms, while
also decreasing the opacity. Composite
films prepared with sorbitol had significantly lower permeability
to water vapor and higher tensile strength than the
films plasticized with glycerol. Improved appearance
was observed in coated grapes after 21 days storage under refrigerated conditions, which had lower
weight loss than the control group. Sensory evaluation showed that all the coatings did not affect
acceptability scores.