Browning Reaction of Valine and D-glucose Under Microwave Heating

The Maillard reaction between valine and D-glucose under different reaction conditions such as pH value, reacting time and proportion of solvents in a microwave heating system was tested.The effects of the reaction conditions on the reaction intensity of Maillard reaction products (MRPs) were investi gated.The MRPs generated nder microwave heating and conventional heating were compared.The ethersoluble compounds of MRPs were further analyzed by GC and GC/MS, and MRPs added cigarettes were evaluated.The results showed that:1) the browning reaction of valine and D-glucose was accelerated by microwave heating, the contents of some major components in MRPs by microwave heating were higher than those in MRPs by conventional heating;2) reaction temperature in a browning reaction was more important than way of heating;3) for the same system, the components in MRPs generated under microwave heating and conventional heating were basically the same, while their contents were different;4) the speed and products of browning reaction were greatly affected by the pH value of system and either acidic or basic condition could accelerate the reaction;5) five important pyrazines and one furan were identified in MRPs generated by microwave heating, while the compounds usually contained in MRPs such as aldehydes and pyrroles were not found;and 6) a good flavoring effect was obtained by addition of the MRPs coming from valine and D-glucose in the mixture of 50% propene glycol and 50% water (v/v) heated by microwave for 30 minutes at pH6.35.