ABSTRACT
Chitosan is a deacetylated derivative of chitin, an important naturally occurring linear polysaccharide. The amino group of chitosan with a glucosamine moiety possesses some interesting intrinsic properties and conformational variability such as biocompatibility, biodegradability, non-toxicity and antimicrobial activity; it has created an increasing attention in the fields of agriculture, biotechnology, food technology, environmental sciences, medicine and cosmetics. This chapter provides an overview of the structural-functional relationship of chitosan. Due to the intrinsic flexibility and conformational variability, chitosan - a derivative of chitin, has attracted scientific and industrial interest in several fields, such as biotechnology, pharmaceutics, biomedicine, packaging, wastewater treatment, cosmetics, and food science. Shell waste produced by industries from shrimp, crab and lobster are traditional sources of chitosan. Chitin and chitosan are semicrystalline in nature, derived by a solid-state reaction resulting in heterogeneous distribution of acetyl groups. Infrared spectroscopy has been the most widely used technique to determine the degree of acetylation of chitosan.
