Influence of D-Glucose Configuration on the Kinetics of the Nonenzymatic; Browning Reaction

Summary The kinetics of the nonenzymatic browning reaction, especially caramelization, was influenced by the configuration of D-glucose. Spectrophotometric analysis suggests a higher reactivity of β-D-glucose in comparison with α-D-glucose during caramelization. More 5-hydroxymethyl-2-furaldehyde (HMF) and 2-furaldehyde (FF) were obtained from β-D-glucose than from α-D-glucose. In addition to the 3-deoxyglucosone pathway, an alternative mechanism via two C3-fragments was proposed. The formation of 1,6-anhydro-β-D-glucose and glucobioses was independent of the configuration of glucose because it passes through a glycosyl cation. Due to steric preference, the 1→6-linked glucobioses isomaltose and gentiobiose are favoured. Under Maillard reaction conditions, the formation of HMF was also influenced by the configuration. At the start of the reaction the Amadori compound was formed slightly easier from α-D-glucose.