Analyse Thermodynamique des Isothermes de Sorptions des Figues

Abstract

In this study, the hygroscopicity and thermodynamic properties of figs were studied to simulate their hygroscopic behavior during storage and drying. The experimental results were analyzed by the nine models of sorption isotherms. The Peleg model was considered the most appropriate to describe the relationship between the equilibrium moisture content and water activity. The thermodynamic functions such as net isosteric heat sorption, the entropy of sorption, spreading pressure, net integral enthalpy, and entropy were determined. Net isosteric heat of sorption and sorption entropy decreased with increasing moisture content. The heat of desorption is slightly greater than that of adsorption with low moisture content. The integral net enthalpy decreases with the moisture content while the entropy integral net increased. The theory of enthalpy-entropy compensation can be successfully applied to water sorption by fig.

Keywords

• figs
• adsorption
• desorption
• isosteric heat
• enthalpy
• entropy