The aim of this work was to evaluate the effect of high intensity ultrasound and NaCl concentration on the brining kinetics (5 +/- 1 degrees C) of pork loin as well as its influence on the textural and microstructural changes. In order to identify the effect of both factors on NaCl and moisture transport, kinetics were analyzed by taking the diffusion theory into account. The textural and microstructural analysis of raw and brined meat both with and without ultrasound application was carried out. The experimental results showed that the brine NaCl concentration not only determined the final NaCl content in meat samples but also the direction of water transport. The NaCl and moisture effective diffusivities were improved by ultrasound application. The final NaCl and moisture content and the ultrasound application promoted changes in instrumentally measured meat texture, which were confirmed via microstructural observations. (c) 2013 Elsevier Ltd. All rights reserved.