The objective of this investigation was to study the kinetics of NaCl (sodium chloride) diffusion in chicken breast during curing process. By means of experimental planning, tests were carried out to optimise the process variables: concentrations of NaCl, phosphate and dextrose in the curing brine and the process temperature. Based on the improvement of brine gain during curing and reducement of losses during cooking, four conditions were determined to assess the kinetics of curing. The analytical solution of Fick's Second Law was used to calculate the effective diffusion coefficients of sodium chloride and to estimate the amount of NaCl absorbed. Good agreement was obtained between the analytical model and the experimental data. The diffusivities of sodium chloride in chicken breast were in the range of 8.99 x 10(-10)-9.55 x 10(-10) m(2)/s. (c) 2006 Elsevier Ltd. All rights reserved.