Physicochemical characteristics and functional properties of various commercial chitin and chitosan products

Physicochemical characteristics and functional properties of five commercially available chitins and five chitosans were investigated. Physicochemical characteristics (nitrogen, ash, degree of deacetylation, bulk density, and viscosity) differed with products. In functional properties, dye binding capacity differed depending on the products, although average binding capacity (63%) of chitosans was higher than that (54%) of chitins. Water binding capacity ranged from 381 to 673% for chitins and from 458 to 805% for chitosans. Fat binding capacities of chitins were mostly similar (316-320%) except for one product (563%), whereas chitosans showed dissimilar binding capacities from 314 to 535%. However, significant correlations were observed between water binding capacity and bulk density (r = -0.89, P < 0.01) and between fat binding capacity and viscosity (r = 0.72, P < 0.05) of chitin products. Both water and fat binding capacity of chitosan products were significantly correlated positively with ash (r = 0.81, 0.80) and negatively with bulk density (r = -0.98, -0.95). Emulsifying capacity of egg yolk increased by addition of chitosan compared with the control. No differences in emulsifying capacity of chitosan products were observed at each concentration tested.