Cross mass transfer including water entrance and solute loss from Rice Crispies were characterised and underlying mechanisms are proposed. Various techniques were tested, and conventional techniques involving phase separation, weighing and oven-drying for determination of water content showed wide variability due to the delicate operation of phase separation. A non-destructive, non-invasive NMR method was also developed. Special care was paid to the contribution of non-aqueous protons to the liquid signal from hydrated Rice Crispies. The kinetics of water absorption obtained from NMR relaxation amplitudes were within the range of those obtained from conventional techniques. It was also possible to monitor solute leaching from the relaxation rates of protons from the immersion water. (c) 2005 Elsevier Ltd. All rights reserved.