Effect of power ultrasound on sodium chloride diffusion during marinating rabbit meat

Abstract. The consumption of rabbit meat is very scarce in Mexico despite its good taste and high protein content. Marinating can be an option to introduce this meat into new markets and at the same time add value to this food. It has been reported that the use of ultrasound accelerates the impregnation process and improves product quality. The objective of this study was to investigate the effect of power ultrasound on sodium chloride diffusion mechanism in rabbit meat samples during acidic marinating. For this purpose, acidic marinating solutions were prepared, with 70, 140 g or 200 g NaCl/L. All the solutions included 3 g NaNO2 and 1.5% citric acid. Rabbit meat slices (5 x 3 x 1 cm3) were immersed in every solution (1:5 sample:solution) during 120 min in static bath, samples were taken at 0, 15, 30, 45, 60, 90 and 120 min. The same procedure was carried out in samples immersed in an ultrasonic bath at 40 kHz and 110 W of output power. Sodium chloride was determined by the Mohr method, by titration with AgNO3. Mass transfers were modeled using a diffusion model. Sodium chloride content increased in meat with increased immersion time, with salt content in solutions and with higher rate in ultrasonic treatment. The values for the sodium chloride and water diffusion were higher (p<0.05) for acidic solutions at 200 g NaCl/L than solutions at 140g NaCl/L and 70g NaCl/L. Diffusion model apply satisfactorily for treatments with ultrasound (correlation coefficients higher than 0.90). Application of ultrasound has high potential to be employed in the marinating of rabbit meat samples, diminishing the immersion time and getting good penetration of the salts agents in the sample.