Analysis of changes of vibrational properties of water in the presence of disaccharides

Results of inelastic neutron scattering (INS) measurements performed by the MARI spectrometer (ISIS, UK) on aqueous solutions of sucrose and α,α-trehalose are reported. To get some insight into the effects of disaccharides on the hydrogen-bond network of water, we investigated the intramolecular O–H stretching modes. The obtained spectra show that, contrary to sucrose, the presence of trehalose affects significantly the pure-water O–H stretching mode. The observed changes can be related to the presence of heavier vibrating units, namely to the higher hydration number of trehalose with respect to sucrose.