alpha,alpha-trehalose/water solutions. 5. Hydration and viscosity in dilute and semidilute disaccharide solutions

We report viscosity and compressibility measurements of trehalose, maltose, and sucrose aqueous solutions at different concentration and temperature v alues. What emerges from the concentration dependence of viscosity and comp ressibility is that trehalose, in comparison to maltose and sucrose, shows a higher interaction strength with water, which gives rise to a greater val ue of the hydration number throughout the investigated temperature range. F urthermore, viscosity measurements reveal that at high concentration values , trehalose shows a "stronger" kinetic character than the other disaccharid es, namely, a lower structural sensitivity to temperature changes in the in vestigated temperature range. This result could explain the greater cryptob iotic attitude of trehalose at high concentrations. The present work, which consists of quantifying experimentally the basic hydration behavior and so lution structure of the investigated disaccharides as a function of concent ration and temperature, allows the working hypothesis of the several existi ng simulation approaches to be tested.