EVALUATION OF MOLECULAR WEIGHT OF CHITOSAN IN THIN-LAYER AND SPOUTED BED DRYING
Chitosan is chitin in deacetylated form and is the main constituent of crustacean exoskeletons. Commercially, chitosan is dried in tray driers, and during the operation, polymerization may occur as the chitosan is composed of carbohydrates. The aim of this work was to analyze chitosan in spouted bed and thin-layer drying, considering viscosity average molecular weight of the chitosan samples in the process. Results showed that spouted bed-dried chitosan presented a molecular weight value similar (160 kDa) to that of the raw one (150 kDa). However, when dried on tray dryers, the molecular weight was 300 kDa, indicating that molecule polymerization occurred. PRACTICAL APPLICATIONS
Chitosan, a deacetylated form of chitin, is considered a functional food. The use of chitosan in various areas is directly related to the molecular weight and degree of deacetylation, which depends on the conditions of chitin deacetylation and chitosan drying. One of the main steps of the chitosan production process is drying. Industrial chitosan is dried in tray dryers; however, it is composed mainly of carbohydrate monomer units capable of undergoing polymerization during the drying operation. The spouted bed dryer is a method that promotes direct particle–fluid contact, with high rates of heat and mass transfer. Also, it presents an alternative to the spray-dryer in an attempt to obtain dry products with the same quality, at low costs. This work presents the study of chitosan drying in spouted bed and thin layer, in paste form, considering the viscosity average molecular weight of the chitosan samples in the operation.
Document Type: Research Article
Publication date: 2011-02-01