Desenvolvimento e caracterização de filme biodegradável à base de amido contendo casca de jabuticaba (Myrciaria cauliflora)

Abstract

Alternative technologies are being developed to minimize the use of plastics, and the use of biodegradable polymers is gaining prominence. Biodegradable polymers, such as starches and polypeptides, are used in biodegradable films, together with plasticizers and solvents, and consist of thin layers of polymeric matrix that are degraded by the action of microorganisms. A class of films that is being developed are films based on fruits and vegetables, which offer good barrier properties, mechanical properties and allow the incorporation of natural additives, such as antioxidants. Jaboticaba (Myrciaria cauliflora) is a native Brazilian fruit, which has a high antioxidant activity in its rind and a high content of bioactive compounds, high potential to be applied in active films. In this context, the objective of the present work was to develop and characterize biodegradable films based on starch and gelatin containing jaboticaba peel. For this, the peels of jaboticaba were analyzed for a proximate composition, the content of bioactive compounds and an antioxidant activity. Cassava starch, gelatin, glycerol and jaboticaba peel were used in the production of the films. The films were characterized by evaluating the visual aspect, thickness, mechanical properties, water solubility, water vapor permeability, scanning electron microscopy, differential scanning calorimetry, antioxidant activity, phenolic compounds and anthocyanin. Regarding the characterization of the jaboticaba peel, the fruit byproduct has a proximate composition rich in fibers, proteins and carbohydrates, in addition, the peel has a high content of phenolic compounds and anthocyanins and a high antioxidant activity. The production of biodegradable films resulted in homogeneous and malleable films, and the addition of jaboticaba peel extract (CJ) did not affect the average thickness of the films, but had a direct influence on the mechanical properties of elongation and tensile strength, where, the increase the concentration of CJ became the most elastic and least resistant films. The produced films showed good thermal properties and physical-defined properties, which were affected by the CJ concentration, the increase in concentration caused a decrease in water solubility, an increase in the water vapor permeability of the films and a change in the color of the formulations. When analyzing a microstructure of the films it was possible to notice an increase in the heterogeneity of the polymeric matrix of the film, in addition, it was found that the films did not preserve the bioactive compounds and an antioxidant activity present in the CJ. In general, the results obtained in the present work demonstrate that the good characteristic source films, however, were not able to incorporate the bioactive properties of the jaboticaba pell.