Formulação e caracterização de biofilmes ativos à base de pectinas extraídas de frutos amazônicos

Abstract

The development of biodegradable packaging for the food industry, using natural resources with mechanical and barrier properties that resemble conventional packaging, is an urgent challenge. Pectin is a natural polymer with great potential for forming matrices in films of this nature. Thus, the aim of this work was to extract pectins from Amazonian fruits for the production of biodegradable films and coatings. For this purpose, Amazonian fruits were selected based on availability and seasonality (biribá, suspiro passion fruit, and araçá-boi) and analyzed for their physicochemical properties, nutritional content, phenolic compounds, flavonoids, and antioxidant capacity. The peels of biribá and suspiro passion fruit and the fruit of araçá were subjected to pectin extraction, and the one with the highest yield proceeded to film production using the casting method. The formed films were analyzed for pH, moisture, solubility, hygroscopicity, morphological and mechanical properties. The films were also evaluated for the presence of phenolic compounds, flavonoids, antioxidant, and antimicrobial properties, and finally subjected to testing for application in minimally processed fruits, followed by sensory parameter evaluation.Among the tested fruits, suspiro passion fruit presented the highest calcium pectate content (2.78%). In the analysis of bioactive compounds and antioxidant capacity, biribá peels stood out compared to the other fruits. Biribá exhibited the highest pectin extraction yield relative to dry mass (7.85%) and proceeded to the formulation of biodegradable films. The film formulated with natural pectin extracted from biribá appeared visually free of fractures, with a smooth surface, no bubbles, an opaque appearance, and a slightly heterogeneous distribution. Regarding physicochemical characteristics, the film based on biribá natural pectin showed an acidic nature (pH 2.64) and high solubility (90.58%), favorable characteristics for films or coatings intended for consumption. The film based on natural pectin exhibited an esterification degree of 56.31%, classifying the pectin as highly esterified. For tensile strength tests, the film based on biribá natural pectin appeared to be more resistant and flexible. In contrast, the control film based on commercial pectin exhibited a higher elastic modulus compared to the formulated film.The film based on natural pectin from biribá displayed high levels of total phenolic compounds (2361.78 mg GAE/100 g) and flavonoids (122.95 mg EQ/100 g), whereas these compounds were not detected in the control film. The antimicrobial activity test revealed an inhibition of approximately 50% against Rhodotorula mucilagenosa, Saccharomyces cerevisae, Fusarium oxysporum, and Aspergillus niger. In the application test of the film-forming solution, the coating based on biribá natural pectin showed a significant effect as a treatment for minimally processed melon, reducing changes in physiological, physicochemical, and sensory properties and, consequently, extending the shelf life of the minimally processed melon, in contrast to the results obtained when applied to minimally processed kiwi. Sensory analysis demonstrated that the use of biribá-based pectin coating on minimally processed melon did not interfere with the acceptability by the panelists. Therefore, the film-forming solution based on pectin extracted from biribá peels presented promising characteristics for application as edible films or coatings in minimally processed foods.