Diffusion of nitrite and nitrate salts in pork tissue in the presence of sodium chloride

Abstract

The objective of the present work was to analyze the effect of NaCl concentration on the diffusion coefficients of NaNO2 and KNO3 in pork tissue using unsteady techniques. Concentrations of nitrite and nitrate as a function of immersion time were determined in cylinders of meat using spectrophotometric techniques; experiments were performed at 4°C and 20°C. The unsteady state mathematical formulation was applied considering radial mass transfer. The diffusion coefficients were obtained fitting the theoretical curves to experimental data. An increase of the salt diffusivities in the tissue was observed when the diffusion occurred at high NaCl concentrations. This fact could not be explained by the Maxwell-Stefan theory. Penetration of high NaCl concentration in a tissue may affect the cellular structure leading to higher diffusion coefficients.