Solution properties and the sweet taste of small carbohydrates

In addition to a knowledge of their structure, especially the geometry of the (AH–B, γ) glucophore, it is necessary to obtain information on solution properties of small carbohydrates if one wishes to elucidate the mechanism of their sweet taste. Macroscopic (viscosity, calorimetry) and microscopic (vibrational spectroscopy) methods have been used to investigate the solution properties of mono- and di-saccharides and a very sweet chloroderivative of sucrose (TGS). The intrinsic viscosity, [η], and Huggins constant, k′, permitted a description of the overall solute–solvent interactions. It was not easy to correlate calorimetric results with sweetness. Fourier-transform infrared studies of solid sugars permitted proposition of glucophores in the light of the observed OH vibrations. An analysis of Raman spectra in the OH stretching region provided information on the effect of traces of the sugars on the structure of water and helped in defining the role of water in the sweet taste mechanism.