Evaluation of the Acyclic State and the Effect of Solvent Type on Mutarotation Kinetics and on Maillard Browning Rate of Glucose and Fructose

Abstract

Summary The concentration of acyclic sugar in D 2 O solutions of glucose or fructose using FITR spectroscopy was determined. This showed that for glucose, since no 1R peak was found, the acyclic concentration is less than the detection limit of 0.001% at all pHs studied (5-10). while there was a just detectable peak for fructose, so that the acyclic concentration for fructose is around 0.001% in the pH range 6 to 10. These values are less than those reported by other methods (polarography and circular dichroism). The browning rate was less in D 2 O than in H 2 O for both sugars, but did not follow the expected mass ratio of solvent. Also the rate of browning did not follow the same ratios as the mutarotation rates in the two solvents studied, i.e. fructose browned about 2.5 times faster than glucose, but had a mutarotation rate that was 10 times faster than glucose. The addition of electrolytes has a significant effect on the browning rate in water, while the effect on the mutarotation rates of glucose and fructose in water is insignificant at a level of p = 0.05.