Modeling Rehydration Behavior of Dried Figs

Abstract

In this research, rehydration behavior of dried fig s was studied at different temperatures (25, 60, 70, 80, and 90 ° °° ° C). The rehydration kinetic was examined using the four most frequently used empirical models, namely, Weibull, Peleg, first-order, and exponential association models. The Weibull model gave the high est coefficient of determination (R 2 ) and the lowest values of root mean square error (RM SE), sum of squared error (SEE), and chi-square ( χ 2 ) was considered the best. In all models examined, the equilibrium moisture content showed statistically significant difference s as compared to the rehydration temperature. The temperature dependence of kinetic constants was described in terms of Arrhenius relationship. The average activation ener gy for the four models was 24.362 kJ mol -1 . During the rehydration process hardness of dried figs decreased, which was further confirmed by microscopic evaluation. Scanning elect ron microscopy (SEM) images of rehydrated figs indicated porous structure proposin g the presence of free water. Keywords : Kinetic model, Moisture content, Texture, Water a bsorption.