Methods of Chitin Production a Short Review
Such characteristics, diverse applications in areas such as agriculture, food, environmental, and as two areas with greater focus: pharmaceutical and health [3,4]. Its structure consists of N-acetyl-d-glucosamine units with β- (1,4) bonds, having as main characteristic the insolubility in water and some organic acids . Chitin belongs to the group of structural polysaccharides, together with cellulose, the second polymer being more abundant in the biosphere [6-9]. Due to its structural nature, a product release system was not found in any of the arthropod exoskeleton, in the structures of molluscs , in the cell wall of fungi [11,12], protozoa and bacteria, egg shells of nematodes [13,14], the shrimp fishery residue being the most widely used source .Throughout the decades of research and handling of this polymer, many methods of extraction have been developed, being the chemical method most found in the literature, being also used in the means of production of industrial chitin. The USA, Japan, India, Canada, China, South Korea, Russia and Norway generally use the reject of crustacean fishing for production. The use of strong acids and bases in the chitin extraction process generates critical points to the process, such as: high cost of the materials involved, generation of chemical effluent and final product with low levels of purity [16,17]. Biological processes become more attractive because they have an affordable cost of production, do not generate high risk effluent (such as the chemical process) and high-quality final product [18,19]. All the processes found in the literature are an objective: to obtain chitin by separating the proteins and minerals from the raw material used . Chitin, besides having great biotechnological value, generates by-products (such as chitosan) that also have added value and even more relevant properties. In this paper we discuss the already known processes of obtaining chitin known and registered in the literature of 2010 up to the present moment: Chemical, enzymatic and biological processes relating the different methods of obtaining and with the objective to identify the particularities of each process regarding the industrial viability and economically balancing them so that the reader concludes the best process for their research, also the possibility of executing quality improvements in these processes. We will also discuss the polymorphic structures of α- and β-chitin and the different methods of obtaining each, since different processes are required in each of them due to their structures, properties and reactivity. The main objective of this review is to be able to relate the different processes of obtaining chitin with the most suitable applications for the method, based on such relation in aspects such as degree of purity and economic applicability.