Basic Structure of Melanoidins Formed in the Maillard Reaction of 3-Deoxyglucosone and γ-Aminobutyric Acid

Melanoidins are formed in foods during processing through the Maillard reaction between carbohydrates and amino compounds. The aim of this study was to draw conclusions about the formation mechanism and the structure of melanoidins formed at low water contents and low temperatures. In the Maillard reaction of D-glucose and gamma-aminobutyric acid at low water contents 3-deoxyglucosone is the most important intermediate. Therefore, we used the reaction of 3-deoxyglucosone with gamma-aminobutyric acid or beta-alanine as a simplified model system. The degradation of 3-deoxyglucosone and the color formation of the formed melanoidins were determined. In addition, the reaction mixture was analyzed with high-resolution mass spectrometry and a Kendrick analysis was applied. Oligomers consisting of up to four molecules of 3-deoxyglucosone and three amino acids and their respective dehydration products with furanoidic structure were detected. The melanoidin structure of C-C linked monomeric units postulated by Kroh et al. could be confirmed.