Many food deterioration reactions such as lipid oxidation, enzymatic reactions and non-enzymatic browning. and the growth of important microorganisms depend directly on water activity. They occur more rapidly away from the optimum moisture contents required for storage stability of dehydrated and intermediate moisture foods (Tunc and Duman, 2007). It has been shown that most deteriorative reactions in food systems have the lowest rate at the Brunauer-Emmet-Teller (BET) monolayer which usually corresponds to the water activity (aw) range of about 0.2-0.4. An increase in aw beyond this region will induce an increase in the reaction rate generally by a factor 50-100% for each 0.1 aw change (Labuza et al., 1985) The other application of moisture sorption isotherms is in food engineering in which the accurate computation of equilibrium moisture content values permits designing and optimization of drying process, aeration, storage, and a calculations of drying times (Tunc and Duman, 2007). Formulation of an analytical relation for predicting of sorption behavior of foods presents difficulties due to complexity of their structures.