DSC study of sucrose melting

Area of Science:

• Food science and technology
• Materials science
• Physical chemistry

Background:

• Crystalline sucrose undergoes thermal transitions detectable by differential scanning calorimetry.
• The physical properties of crystalline sucrose are sensitive to its crystallization and purification history.

Purpose of the Study:

• To investigate the factors affecting the endothermic transition of crystalline sucrose around 150°C.
• To understand the impact of recrystallization conditions and impurities on sucrose's thermal behavior.

Main Methods:

• Differential scanning calorimetry (DSC) was used to analyze crystalline sucrose.
• Sucrose was recrystallized from solutions with varying compositions (mineral salts, organic solvents, polysaccharides) and under different physical conditions (stirring, temperature).

Main Results:

• An endothermic peak for crystalline sucrose was consistently observed near 150°C.
• The enthalpy of this peak varied depending on the sucrose source.
• Mineral salts in recrystallization solutions decreased the peak enthalpy, while their absence increased it.
• Organic solvents and polysaccharides had a less pronounced effect than inorganic impurities.
• Increased stirring and higher recrystallization temperatures reduced the peak enthalpy.

Conclusions:

• The thermal behavior of crystalline sucrose, specifically the 150°C endothermic peak, is significantly influenced by recrystallization processes and the presence of impurities, particularly mineral salts.
• Optimizing recrystallization conditions and controlling impurity levels are crucial for consistent sucrose properties.