Determination of water effective diffusion coefficient of sardine sheets during vacuum pulse osmotic dehydration

The water effective diffusion coefficient of sardine sheets during vacuum pulse osmotic dehydration was determined. Sardine sheets (20.1×15.0×6.4 mm3) were osmotic dehydrated at brine concentrations between 0.15 and 0.27 g NaCl/g, and temperatures between 32 and 38 °C. The water effective diffusion coefficient ranged approximately from 1.46×10−10 m2/s to 2.41×10−10 m2/s. In general, diffusion coefficient increased with increasing concentration and temperature. Dependence on temperature followed an Arrhenius relationship, regardless of concentration Diffusion coefficient at 0.18 g NaCl/g was found to be the most temperature sensitive (Ea=39.62 kJ/mol) while that at 0.15 g NaCl/g was the least temperature sensitive (Ea=23.67 kJ/mol). The water effective diffusion coefficient was empirically correlated with concentration and temperature of osmotic solution. A high degree of correlation was observed between predicted and experimental values of the water effective diffusion coefficient (R2=0.856).