A Kinetic Study of the Early Stages of the Maillard Reaction

The Maillard Reaction is a complex series of reactions between an amino acid and a reducing sugar that has important physiological implications, particularly for diabetes mellitus. The application of a sensitive and selective analytical method developed to study the kinetics of the initial stages of the Maillard Reaction will be described. The method is based upon sample pre-treatment by sequential injection (SI) with a liquid chromatography column prior to detection by low-field nuclear magnetic resonance spectroscopy (NMR). The SI-NMR method improves the sensitivity and selectivity of the 45 MHz picoSpin™ NMR spectrometer by effectively pre-concentrating the sample before the sample zone enters the flow cell. The initial steps in the reaction between alpha-dicarbonyl compounds (e.g., glyoxal and methylglyoxal) and primary amines (e.g., phenylalanine-methylester) was monitored on-line with SI-NMR. This approach allowed for detailed study of the behavior of alpha-dicarbonyls and a kinetic study of the initial stages of the Maillard Reaction.