Obtención de quitosano a partir del micelio de Aspergillus niger y su aplicación como recubrimientos comestibles para la conservación de frutas.

Abstract

This investigation raised the obtaining of the chitosan from the mycelium of Aspergillus niger, to use in the preparation of edible coatings that allow preserving fruits. For the extraction process, nine tests were carried out that consisted of chemical treatment of 20 g fungus mycelium samples with sodium hydroxide and hydrochloric acid at different concentrations. Between the chitosan samples extracted, only the highest values for each density were reported. And the physicochemical characteristics of these samples were determined by infrared spectroscopy analysis, solubility tests, viscosity tests, drying, and calcination. With these samples, three solutions (A, B, and C) composed of chitosan and starch solutions in different concentrations and glycerin were prepared. The physicochemical characteristics of these solutions were determined by drying and film formation, density measurement, pH measurement, and infrared spectroscopy analysis. Solution C was selected because it presented the appropriate characteristics for the creation of coatings. It was determined that it meets the safety parameters necessary to be considered fit for human consumption. In order to evaluate the functionality of the edible coating in fruit preservation, samples were applied by immersion, in strawberries and blackberries, to which- a sensory evaluation and a daily weighing-, were performed. These test results were compared with those presented by fruits having no coating. At the end of this investigation, it was possible to verify the functionality of these edible coatings in fruit preservation. As They allowed the useful life of strawberries and blackberries to be 7 days at room temperature, and 16 and 12 days at cooling temperature. It indicates an increase in tis conservation time of approximately 5 days.