The experimental data are shown along with the lines drawn from the equations obtained by fitting the experimental data into BET and GAB equations (see Section 2 for more details) The shape of the isotherms of control samples is similar to the so called type 1 isotherms which are found for high sugar systems Ayranci et al., 1990). The equilibrium moisture content increased slowly with water activity until the aw of about 0.65, after which a small increase in humidity led to a large increase in equilibrium moisture content. The equilibrium moistures obtained at 5 oc were in agreement with the data reported by Pixton and Warburton (1976). At low water activities, water can be adsorbed only to surface -OH sites of crystalline sugar. Therefore, moisture content is low at low water activity region, while at high water activities dis solution of sugars occurs and crystalline sugars are converted into their amorphous form. So the amount of water to be adsorbed in creases greatly after this transition because of the increase in the number of adsorption sites upon breakage of the crystalline struc ture of sugars. This form of isotherms is similar to those observed for dried apricot, figs and raisins (Ayranci et al., 1990; Tsami et al.,