Searching the most optimal model of water sorption fruit powder (original) (raw)

The present work aims to investigate the moisture adsorption characteristics of Lyophilized Algerian Arbutus unedo L. fruit powder (LP). First, the LP was evaluated for some of its physicohemical parameters, including X-ray diffraction (XRD) properties, crude fiber, titrable, etc. Second, the experimental sorption curves, determined at 20, 30 and 40 °C with the standard static-gravimetric method, were fitted to six isotherm models (Kühn, Caurie, Smith, Halsey, Oswin and GAB). Results showed also that the moisture adsorption isotherms of LP are of Sshaped profile (Type II), generally obtained for biomaterials. Among all tested models, those of Halsey and GAB (T=20 and 30 °C) gave the best fits at 20 and 30 °C, with the mean relative percentage deviation modulus (E%) less than 1%, χ 2 ≤ 2.68 10 -1 and a root mean square error (RMSE) ≤ 0.2808). The K parameter of GAB model was found to increase with increasing temperature, whereas the monolayer moisture content (X 0 ) decreased with increasing temperature. Such data are represent a usefull tool for choose appropriate storage conditions of LP.