Degradation of oligosaccharides in nonenzymatic browning by formation of alpha-dicarbonyl compounds via a "peeling off" mechanism.
The formation of alpha-dicarbonyl-containing substances and Amadori rearrangement products was studied in the glycine-catalyzed (Maillard reaction) and uncatalyzed thermal degradation of glucose, maltose, and maltotriose using o-phenylenediamine as trapping agent. Various degradation products, especially alpha-dicarbonyl compounds, are formed from carbohydrates with differing degrees of polymerization during nonenzymatic browning. The different Amadori rearrangement products, isomerization products, and alpha-dicarbonyls produced by the used carbohydrates were quantified throughout the observed reaction time, and the relevance of the different degradation pathways is discussed. In the Maillard reaction (MR) the amino-catalyzed rearrangement with subsequent elimination of water predominated, giving rise to hexosuloses with alpha-dicarbonyl structure, whereas under caramelization conditions more sugar fragments with an alpha-dicarbonyl moiety were formed. For the MR of oligosaccharides a mechanism is proposed in which 1,4-dideoxyosone is formed as the predominating alpha-dicarbonyl in the quasi-water-free thermolysis of di- and trisaccharides in the presence of glycine.
Hollnagel
A
A
Institut für Lebensmittelchemie, Technische Unversität Berlin, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany.
Kroh
L W
LW
D004187:Disaccharides / Q000378:metabolism*; D007700:Kinetics; D015416:Maillard Reaction; D009844:Oligosaccharides / Q000378:metabolism*
D004187:Disaccharides; D009844:Oligosaccharides