Sugars are thought to owe their sweet taste to the particular pattern of bonds that atoms in sugar molecules form with receptor proteins in taste buds. But most types of sugar have a similar arrangement of atoms, so why some taste sweeter than others has proved puzzling.
Another puzzling property of sugars is their ability as protectant against drought or freeze.
Both issues are tackled by neutron diffraction experiments on aqueous solutions.
In particular, it is found that the strength of the molecules’ hydrogen bonds may be the primary factor in determining a sugar’s level of sweetness.
Moreover the issue of drought resistance is investigated in the case of trehalose, showing that this disaccharide entraps a layer of water molecules in the first shell of a model peptide, namely N-Methylacetamide, without direct bonding with it.