Obtenção e avaliação dos extratos e óleos de canela e cipó d’ alho e aplicação em filmes biodegradáveis: estudo experimental e teórico

Abstract

Various spices such as dried fruits and food grains are prone to contamination by filamentous fungi, such as the species Aspergillus Niger, increasing the risk of ingestion of mycotoxins by the population. The production of biodegradable films added to extracts and essential oils can give the same antifungal properties. Thus, this study aimed to develop biodegradable films based on cassava starch with addition of extracts and oils of cinnamon and garlic vine and evaluate its efficiency against the fungus Aspergillus Niger. The ethanol and aqueous extracts were obtained by Soxlet extraction and maceration, respectively, while the oils were obtained by hydrodistillation. To identify the major compounds of the extracts and oils, NMR and Gas Chromatography analyzes were performed. These compounds identified were selected as ligands before the enzyme glucose oxidase produced by the fungus for the theoretical study through Molecular Docking. The extracts and oils were evaluated in antifungal diffusion tests in discs and wells, respectively. The biodegradable films were prepared with extract and oils of cinnamon and garlic vine that showed better performance in antifungal tests. All the elaborated films were evaluated in the antifungal test by means of the technique of diffusion in discs. In the theoretical study through Molecular Docking, all the ligands present in the extracts and oils showed hydrogen bonds with the key amino acid residues of the enzyme glucose oxidase being Histidine (His 559 A), Threonine (Thr 110 A) and Arginine (Arg 512 A). In the antifungal tests, the ethanolic extract of the plant species garlic vine showed a higher inhibition halo of 15mm at a concentration of 20mg/ml while the antifungal tests for oils, at volumes of 1 µl; 5 µl and 10 µl revealed the formation of inhibition halos of 25mm; 28mm and 30mm for cinnamon oil. While, in the film with the oil of the vine of garlic, the inhibition of the germination of said fungus occurred during 9 days of experiment. The antifungal tests of the films revealed that the films with surfactant containing garlic vine oil did not present sporulation halos and neither mycelial growth on films 1 and 2 during the 48h of the experiment, inhibition of the growth of the fungus through the films.