Impact of melting conditions of sucrose on its glass transition temperature.

The impact of the melting conditions of sucrose crystals on the glass transition temperature (T(g)) of the sucrose melt was studied. Final temperature, heating rate, and the residence time at the final temperature were the experimental conditions considered. The glass transition temperature of the different glasses was measured by differential scanning calorimetry, and the degradation of sucrose during the thermal treatments was studied by high-performance liquid chromatography. The results showed that the T(g) is sensitive to the degradation of sucrose: T(g) decreases with the appearance of small molecules and then increases with the appearance of polymerization products. Thus, the choice of thermal treatment is of the utmost importance for the determination of the T(g) of pure sucrose.