Hydration of two artificial sweeteners: Possible relevance for their taste

Abstract The hydration of acesulfame-K and aspartame is investigated by neutron diffraction with isotopic substitution, implemented with Monte Carlo analysis. Results confirm, as found for natural sugars, that the strength of the hydrogen bonds made by these sweeteners in their direct or water mediated interaction with the receptor plays a key role in determining the intensity of the sweet taste. Moreover it is evident that the enhancement of the sweet taste by orders of magnitude, as in the case of artificial sweeteners, is obtained by tailoring the molecular structure such that it can accommodate a large number of water molecules in its hydration shell, while offering to the solvent a broad hydrophobic region.