aDepartment of Food Science and Technology, Catholic University of Daegu, Hayang 712-702, Republic of Korea
bDepartment of Food Science, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA
Abstract:
Some physical characteristics of decolorized chitosan as affected by sun drying, which was used to replace a bleaching step during chitosan preparation, were evaluated. One bleached and four unbleached chitosans were prepared and dried for 4 h by heat treatment at 60 °C or sun drying. The moisture content of chitosans dried by heat treatment was lower than that of chitosans dried by sun drying. Decoloration of the chitosan could be achieved more effectively by sun drying after deacetylation than by using a bleaching agent in the chitin preparation. Use of a bleaching agent significantly reduced the viscosity of the chitosan solution. A sequence of heat drying and sun drying in chitin and chitosan production (without using a bleaching agent) generally produced a whiter chitosan with higher viscosity without affecting water- and fat-binding capacities, compared to the bleached chitosan.