ABSTRACT
Chitosan is a natural nontoxic biopolymer produced by the deacetylation of chitin, a major component of the shells of crustaceans, such as crab, shrimp, and crawsh. Chitin and chitosan are insoluble in water as well as most organic solvents, which is the major limiting factor for their utilization in living systems. Hence, it is important to produce soluble chitin or chitosan by various methods, such as acidic and enzymatic hydrolysis. Chitooligosaccharides (COS), partially hydrolyzed products of chitosan, or chitin, are of great interest in pharmaceutical and medicinal applications because of their noncytotoxic and high water-soluble properties. Various activities of COS are affected by degree of deacetylation (DD) and molecular weight (MW), or chain length (Razdan and Pettersson, 1994; Muzzarelli et al., 1999; Xia et al., 2011).
