Chitosan, From Residue to Industry

Industrial activity associated with processing of crustaceans generates large quantities of waste. The main residue corresponds to its exoskeletons constituted primarily of chitin. Through a modification on its structure, chitosan is derived, the only polycationic polymer in nature. This work aims to review a wide variety of aspects concerning chitosan. First it studies the chitosan properties: biodegradability, biocompatibility and non-toxicity. Its high density of positive charges makes it a versatile material, being able to be used in practically all the industrial fields. Agriculture, biotechnology, food, wastewater treatment and medicine are the main examples. Then it compares different chitin and chitosan obtaining methods being mostly used chemical treatments. The biological methods are presented as an alternative. Several techniques are necessary for chitosan´s characterization. Molecular weight and deacetylation degree are the most important characteristics which define its potential applications. This chapter analyzes different methods according to the necessity of each situation. An examination on the regulatory status and the global market of this biopolymer is made. A report in 2010 projected its market in 21.4 thousand tons by 2015, placing Japan as the biggest contributor. The main industries are placed in Asia and US. In Latin America, there are plants in Brazil, Chile and México. In Argentina, despite the crustaceans fishing industry continuously growing, there is no industrial chitosan production. This review concludes with a description of the work that is being carried out at the National Institute of Industrial Technology of Argentina in this regard.

Keywords: Antimicrobial, Biocompatibility, Biodegradability, Biopolymer, Characterization, Chitin, Chitosan, Deacetylation degree, Fishing industry, Market, Molecular weight, Non-toxicity, Obtaining process, Polycation, Regulations, Shrimp, Waste.