Influence of ultrasound on mass transport during cheese brining

The effect of ultrasound on mass transfer during cheese brining has been in vestigated. The rate of water removal and NaCl gain increased when ultrasou nd was applied in comparison with brining performed under static or dynamic conditions, suggesting that ultrasound improves both external and internal mass transfer. A simple diffusional model was developed to simulate mass t ransport during acoustic brining. Model parameters were estimated using exp erimental data from acoustic brining experiments carried out on cheese cyli nders of 1.7 x 10(-2) m radius and 3 x 10(-2) m height at different tempera tures (5, 15 and 20 degrees C). Effective water (Dw) and NaCl (Ds) diffusiv ities estimated using the proposed model ranged from 5.0 x 10(-10) m(2)/s a nd 8.0 x 10(-10) m(2)/s at 5 degrees C to 1.3 x 10(-9) m(2)/s and 1.2 x 10( -9) m(2)/s at 20 degrees C. Both D-W and Ds varied with temperature accordi ng to the Arrhenius equation. Through the proposed model, water losses and NaCl gains of the experiments used in the parameter identification were acc urately simulated (average %var = 98.2%) and also of two additional acousti c experiments carried out under different conditions of temperature (10 deg rees C) and sample size and geometry [parallelepiped of (6 x 2.5 x 1.25) x 10(-2) m] to those used in the parameter identification (average % var = 98 .4%).