DSC analysis of Maillard browning and procedural effects

A simplified model system containing amorphous glucose and glycine was anal yzed in a differential scanning calorimeter (DSC) under airflow, nitrogen f low and in hermetically-sealed steel pans in order to study the effects of environmental conditions on its thermal behavior. DSC under nitrogen flow i n open pans was chosen to analyze the enthalpy changes during the developme nt of Maillard reaction in glucose-glycine model systems heated at 90C. While heating the glucose-glycine model system in the DSC open pans under d ynamic nitrogen flow, the Maillard reaction was revealed by an endothermal enthalpy change (peak 1) occurring from 100C to 150C, followed, on further heating, by a second endothermal peak (peak 2) from 200C to 260C. DSC trace s of samples previously heated for up to 24 h showed a third endothermal pe ak (peak 3) in the temperature range from 90C to 170C which was gradually d etected while peak 2 tended to disappear. Results indicated that DSC performed under nitrogen flow in open pans allow s the thermal behavior of a model system undergoing the Maillard reaction t o be followed in real time and to differentiate between reaction phases.