Determination and Modelling of Moisture Sorption Isotherms of Chitosan and Chitin

Tano Kablan,^a* Yué bi Yao Clément,^a Kouamé Akissi Françoise^a and Oulé Kégnon Mathias^b

^a UFR of Food Science and Technology, Abobo-Adjamé University, Abidjan, Côte d’Ivoire, 02 BP 801 Abidjan 02
^b Faculty of sciences, University College of Saint-Boniface, 200 Avenue de la Cathédrale, Winnipeg, Manitoba,
Canada R2H 0H7
* Corresponding author: E-mail: pasqual-kab@hotmail-com,
Tel: 225 01-16-85-92 Fax: 225 22-44-46-76

Abstract
Moisture sorption isotherms of chitosan and chitin in granular powder form were determined at 4 °C using the static desiccators’ technique. Ten saturated salt solutions were used to provide constant relative humidity environments. The isotherms were found to be sigmoid type and of BET classification II. The GAB model was used to fit the experimental data, this model was found to be adequate for accurate prediction of moisture sorption isotherm of chitosan and chitin with high value of coefficient of determination (R²) and lower values of root mean square (RMS(%)) and mean relative percentage (E(%)). The value of monolayer moisture content of chitosan and chitin varied according to the method of regression used. The performance of the regression method depends on the product used.

Keywords: Sorption isotherms, water activity, GAB equation, modeling.