Experimental Determination and Modelling of the Sorption Isotherms of Kilishi
André Talla *
Laboratory of Energy, Water and Environment, National Advanced School of Engineering, University of Yaounde I, PO Box 16 034 Yaounde-Cameroon
*Author to whom correspondence should be addressed.
Abstract
Sorption isotherms of kilishi have been experimentally determined at 30, 40 and 50ºC by using salt method for a range of water activity from 0,064 to 0,973. His sorption capacity increases with the temperature for a given water activity. The experimental curves obtained have been simulated by the GAB model. This model enables the representation of the whole desorption isotherms, with maximum deviation of 1.2%kgw.kgdm-1. The water content corresponding to monolayer saturation was estimated. The isosteric heat of sorption is deduced from experimental results and empirical correlations are proposed leading to satisfactorily representation. These results can be used to predict the potential changes in kilishi stability and later for the development of a system of suitable drying.
Keywords: Kilishi, sorption isotherm, isosteric heat, GAB model, specific area