Comparison of the kinetic behavior of crystalline cane and beet sucrose thermal decomposition

Abstract

Although crystalline cane and beet sucrose are > 99.8% pure, they exhibit different thermal behavior. In general, the cane sucrose DSC curve contains a small endothermic peak before the main endothermic peak, which is not present in the beet DSC curve, leading to a lower onset temperature for thermal decomposition in cane. To compare their thermal behavior, the thermal decomposition kinetic parameters for analytical and commercial cane sucrose and commercial beet sucrose were determined. Beet sucrose had a higher activation energy than either cane source, indicating that thermal decomposition is inhibited in beet sucrose. However, the k values from isothermal experiments at a single temperature did not match the nonisothermally predicted k values, suggesting that, while useful for comparison, the nonisothermal kinetic parameters cannot be used to predict the behavior of sucrose thermal decomposition under isothermal conditions.