Journal of Food Engineering, Vol.31, No.1, 85-93, 1997
Effect of temperature on the moisture sorption isotherms of some cookies and corn snacks
Three cookies and two corn snacks were analyzed for major components and their moisture adsorption characteristics were evaluated at 25, 35 and 45 degrees C. The main composition differences were in fat and total carbohydrate content. The isotherms of each product were different (p<0.05) and significantly affected by temperature. The mathematical description of the adsorption data was obtained applying some of the most common sorption equations. Peleg's model gave the best description of the experimental data, followed by GAB equation. The mean relative deviations for Peleg's equation were higher as the temperature increased and varied from 2.81 to 10.60%. Monolayer moisture content evaluated with BET and GAB models were in general lower for the cookies. The maximum net isosteric heats of adsorption were lower than 11 kJ/mol.