Abstract

1H Nuclear Magnetic Resonance (NMR) relaxometry was used to investigate water mobility in brown sugar-water mixtures from different sources, with the goal of understanding how the arrangement of the sugar network affects water mobility and hydration dynamics and whether quantities describing the water dynamics can be linked to sugar origin and quality. 1H spin-lattice experiments across a broad frequency range from 10 kHz to 10 MHz were performed for twenty sugar samples representing different botanical origins (cane, coconut and beet), types of sugar (brown granulated sugar, non-centrifugal sugar and muscovado sugar) and countries. The sugar was mixed with water with the weight ratio (sugar:water) 2:1. The extensive set of relaxation data was analyzed in terms of a dedicating model including parameters describing translation diffusion of water molecules, the fractions of water slowed by entrapment within the sugar network or bound in hydration shells, and a combined effect of hydrated sugar molecules and exchange dynamics of water in the hydration shells. The outcome of this analysis (with focus on the translation diffusion coefficient of water molecules and the fraction of water molecules involved in the translation motion) highlights the potential of NMR relaxometry as a non-invasive tool to assess molecular mobility, arrangement and hydration behavior in sugar systems and offer a new analytical pathway for verifying the authenticity and origin of sugar.