Modeling of the water-sucrose state diagram below 0 °C

The state diagram of sucrose-water solutions was constructed by the use of model calculations; the activity coefficient from the UNIQUAC model allowed determination of the solution-ice equilibrium curve and the glass transition temperature as a function of the composition was evaluated from the Gordon-Taylor equation. The accuracy of the glass transition temperature (T′g) of the maximally freeze-concentrated fraction, determined from the intersection of both curves, was analyzed and discussed. While the UNIQUAC model predicted reliable ice melting temperatures in the high sucrose concentration range, a significant variation of the fitted glass transition curve was obtained due to the selected temperature values for the glass transition temperature. The calculated glass temperatures (T′g) were compared with direct DSC experiments. While the UNIQUAC model predicted reliable ice melting temperatures in the high sucrose concentration range, a significant variation of the fitted glass transition curve was obtained due to the selected temperature values as the glass transition temperature. The calculated glass temperatures (Tg′ were compared with direct DSC experiments.