Thermal Analyses of Polyol-Aqueous Solutions at Temperatures below 0.DEG.C..

Abstract

The thermal properties of polyol-aqueous solutions (xylitol, sorbitol, maltitol and lactitol) in concentrations from 5% to 30% (0.15-2.86 nrolal) were analyzed by differential scanning calorimetry at temperatures from O"C to -52'C and compared with those of their corresponding reducing sugars (xylose, glucose, maltose and lactose). The freezing point depression (AT) values in samples of both groups increased linearly with their concentrations (molal) and were similar to their corresponding sugars. On the other hand, the ice fraction (%) in their samples decreased somewhat depending on the concentration. It was generally observed that the ice fraction in the polyol-aqueous solution was slightly higher than in the corresponding sugar, as estimated by plotting the ice fraction as a function of molality multiplied by the number of -OH groups.