Obtenção de quitosana a partir da combinação de distintos subprodutos de crustáceos

Abstract

The destination of organic solid waste produced during the processing of crustaceans is the great challenge of the fishing industry. Generally, these residues are composed of exoskeleton (carapace, head and appendages) of crustaceans, and correspond to approximately 70% of the animal's weight. Waste bioconversions have been a viable alternative for reuse, as they are composed of proteins, minerals, pigments and chitin. Chitin is the second most abundant polysaccharide on earth, and when subjected to high temperatures in an alkaline medium, it transforms into chitosan, a copolymer of high commercial value. The objective of this study was to obtain chitosan by combining different species of crustaceans. Thus, the chemical method was adopted to obtain chitosan following the steps of: Pre-treatment (washing, drying and grinding), demineralization, deproteinization, depigmentation and deacetylation. Treatments with variations in HCl concentration (1.7%, 3%, 5% and 7%) were applied in the demineralization step. The treatments were applied to 32 samples, namely: gray shrimp, seven-bearded shrimp, crab, crab and lobster and the combined residues of these crustaceans. The results obtained from this methodology were satisfactory as they resulted in chitosan with degrees of deacetylation (DG) greater than 90%, and the influence of the concentration of HCl in the demineralization step on the final quality of chitosan could be observed. From this study, other methodologies can be tested in different concentrations of acids and variations in time and temperature. In addition, studies that enable the development of industrial chitosan production methods, analyzing the feasibility of developing this activity in Brazil.