Otimização do processo de produção de filmes ativos antioxidantes

Abstract

The packaging has the function of protecting the food, maintaining its physical, sensorial and nutritional quality during the whole period of storage. Such packaging can be enriched with active agents to increase the shelf life of the packaged product. Seeking to contribute to increasing shelf life, the objective of the research was to develop and evaluate films produced from starch, chitosan and glycerol, with the addition of cashew tree bark extract, evaluating the properties of the material to determine the formulation that presented the best properties for use in food and actuating as an active packaging. The experiment was developed with the aid of a Box-Behnken-type experimental design, where 15 treatments were carried out, in order to define the best formulation, through statistical desirability, varying the concentration of chitosan, cashew tree bark extract and glycerol, used as a plasticizing agent. The films were evaluated for their physical-chemical (water solubility and water vapor barrier), physical and mechanical (thickness, tensile strength and percentage of elongation at break) and morphological properties (SEM). The statistical criteria for obtaining the best formulation were low solubility and water vapor permeability values, important for maintaining the barrier property for the stored food, and higher values for tensile strength and elongation, important for protecting the integrity of the packaged food. The addition of cashew tree bark extract increased the tensile strength and elongation of the produced material, while glycerol and chitosan had no significant influence on these properties. The films obtained have low solubility and a varied barrier property in relation to the control film (film-forming material without the addition of extract and chitosan), and the addition of cashew tree bark extract to the formulation improved the tensile strength and elongation at break. The films obtained may have antioxidant activities due to the presence of polyphenols, such as tannins, which were maintained in the material produced from the optimized formulation. Based on statistical desirability, it was possible to establish a formulation with proportions of 3% chitosan, 2% cashew tree bark extract and 3,25% glycerol in the matrix based on 5% corn starch in the film-forming material. The physical and chemical parameters obtained for this formulation were greater physical and mechanical strength (14,75N for rupture and 49,43% for elongation) and lower values for water vapor permeability (3,033 g.mm/m².h.kPa) and solubility (1,94%).