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 a nd their moisture adsorption characteristics were evaluated at 25, 35 and 45 degrees C. The main composition differences were in fat and tot al carbohydrate content. The isotherms of each product were different (p<0.05) and significantly affected by temperature. The mathematical d escription of the adsorption data was obtained applying some of the mo st 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 increas ed and varied from 2.81 to 10.60%. Monolayer moisture content evaluate d with BET and GAB models were in general lower for the cookies. The m aximum net isosteric heats of adsorption were lower than 11 kJ/mol. (C ) 1997 Elsevier Science Limited. All rights reserved.