Relationship between macroscopic properties of honey and molecular dynamics – temperature effects

Abstract

1H spin-lattice relaxation studies of different kinds of honey have been performed in a broad frequency range, versus temperature. On the basis of the extensive data set, translation diffusion coefficients and rotational correlation times of water molecules confined in the sugar matrix have been determined. It has turned out that the translation dynamics is of three-dimensional (isotropic) character and its by three orders of magnitude slower compared to water in bulk. This scenario established on the molecular level has been compared with the picture of translation diffusion obtained from viscosity measurements. Systematic discrepancies have been observed for all kinds of honey and their origin has been explained. Activation energies of the translational and rotational motion and ratios between the translational and rotational correlational times have been determined and discussed in the context of the properties of supercooled liquids.