DSC analysis of Maillard browning and procedural effects

A simplified model system containing amorphous glucose and glycine was analyzed in a differential scanning calorimeter (DSC) under air flow, nitrogen flow and in hermetically-sealed steel pans in order to study the Gects of environmental conditions on its thermal behavior. DSC under nitrogen flow in open pans was chosen to analyze the enthalpy changes during the development of Maillard reaction in glucose-glycine model systems heated at 9OC. While heating the glucose-glycine model system in the DSC open pans under dynamic nitrogen flow, the Maillard reaction was revealed by an endothermal enthalpy change beak I ) occurring from IOOC to 15OC, followed, on further heating, by a second endothermal peak (peak 2)from 200C to 260C. DSC traces of samples previously heated for up to 24 h showed a third endothermal peak @eak 3) in the temperature range from 9OC to 170C which was gradually detected while peak 2 tended to disappear. Results indicated that DSC peqormed under nitrogen jlow in open pans allows the thermal behavior of a model system undergoing the Maillard reaction to be followed in real time and to differentiate between reaction phases.