Algerian Journal of Materials Chemistry Alg. J Mat Chem ISSN 2661-7196 Vol.2 Issue 2, pp 75–85, (2019) * Corresponding author. Tounsia AKSIL E-mail address: tounsiaiap@gmail.com Front matter © 2020 University M'hamed Bougara Boumerdes. All rights reserved. 75 Searching the most optimal model of water sorption fruit powder Tounsia AKSIL 1* , Moussa ABBAS 1 , Mohamed TRARI 2 and Salem BENAMARA 3 1 Laboratory of Soft Technologies and Biodiversity (LTDVPMB/F S), University M’hamed Bougara 35000 Boumerdès, Algeria 2 Labotory of Storage and Valorization of Renewable Energies, Faculty of chemistry (USTHB) BP 32-16111 El- Alia, Bab Ezzouar Algeria. 3 Research Laboratory in Food Technology (LRTA) Faculty of Engineering Science University M’hamed Bougara 35000 Boumerdès, Algeria Received: 15 September 2019 /Accepted: 22 October 2019 /Published online: 29 October 2019 Abstract. 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 S – shaped 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. Keywords: Keywords: lyophilized powder; sorption isotherm; modeling; gravimetric method; Water Activity 1. Introduction Strawberry tree (Arbutus unedo L.; Ericaceae family) is a typical Mediterranean wild tree which is also cultivated in other regions of Eastern Europe [1]. Its fruit mature in autumn, at the same time as flowering [2]. Berry fruits can be used for the fabrication of several industrialized products since it is a rich numerous nutriments, specially Calcium, Phosphorus and Potassium [3] Establishing the relationship between equilibrium moisture content (EMC) and a w , also known as sorption isotherm (adsorption or desorption), is one of the useful measurements to the stability, microbiological and the physico-chemical deterioration reactions [4] of a food's. The sorption isotherms show the amount of adsorbed water as a function of steady state water activity (a w ), at constant temperature, it can also be used to investigate the structural features such as the specific surface area, the pore volume, the pore size distribution and the crystallinity of food product [5]. Such data can be used for selecting the storage conditions