In food science, water diffusion is an important transport property necessary for the design and optimisation of food processes. In particular, the characterisation of water mobility represents a considerable challenge to have better understanding of the water organisation in dairy products. The classical method to measure the diffusion coefficient is based on spin echo or stimulated echo sequences. For a complex mixture, the intensity of the spin echo will be the sum of intensities of each constituent weighted by his own relaxation time. If the measurement of the self-diffusion coefficient is performed by high-resolution spectroscopy, then a Fourier transform could be realised on the spin echo. This procedure allows to distinguish the different molecules according to their chemical shifts and to measure selectively their respective self-diffusion coefficients. When the field is low and not shimmed, the NMR signal from the different molecules cannot be distinguished according to their chemical shifts. Consequently, the attenuation of the echo as a function of the gradient pulse strength will be affected by the different self-diffusion and by the relaxation time of the molecules. So the real self-diffusion would not be correctly measured. In this paper, a modified diffusion sequence, which allows to determine the water diffusion coefficient of cheese model, was introduced. This pulse diffusion sequence exploits the difference in relaxation times T1 and T2 between the water and the fat phase, in order to suppress the fat signal. Preparation of cheese model was obtained from the incorporation of a milk fat emulsion into a dairy concentrated protein solution obtained by ultrafiltration. A low-field NMR spectrometer (a Bruker Minispec), operating at 20MHz and equipped with gradients of 4T/m, was used for the NMR measurements at various temperatures (5, 20, 30 and 40°C). The T2 relaxation was measured from a CPMG sequence and the T1 from the Saturation Recovery sequence. Both diffusion sequences will be evaluated on cheese model: i) the spin echo sequence adapted by Bruker and ii) the sequence modified in order to minimise the signal of fat in the spin echo. Our results showed that the contribution of the fat signal in the signal echo can be reduced with this modified sequence and the accuracy of the water diffusion coefficient can be improved significantly (factor of 10).