Edible coatings based on chitosan and beeswax: their usage on the conservation of table grapes

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaFor this study we produced three different formulations to obtain edible films and coatings based on chitosan, incorporated with beeswax, glycerol and a surfactant (Tween 80). It was studied the effect of beeswas concentration (0%, 10% e 20% wax mass per polymer mass) in the properties of the films obtained. Regarding the mechanical properties of the films, the results show that the tensile strength, elongation, Young's modulus, perforation tension and deformation were not significantly affected by the wax concentration used. The Water Vapor Permeability (WVP) and hydrophilicity of the films decreased with wax incorporation. The WVP decreased about 99% due to the permeability of the films without wax. During the performance evaluation of edible coatings, on the study of grapes preservation, it was found that the application of such coatings favors the dehydration of the fruit; as they do not significantly affect the grapes properties (color, texture, brix and pH) compared to the control sample. The sensory and multivariate analysis performed showed that the chitosan coating embedded with wax is not the most suitable for usage on grapes