Water effective diffusion coefficient of sardine sheets during osmotic dehydration at different brine concentrations and temperatures

The water effective diffusion coefficient of sardine sheets during osmotic dehydration was determined, assuming this process to be governed by Fickian diffusion. Osmotic dehydration of sardine sheets (20.1 × 15.0 × 6.4 mm3) was carried out over five concentrations (0.15, 0.18. 0.21, 0.24 and 0.27 kg NaCl/kg) and temperatures between 30 and 38 °C of osmotic solution. The water effective diffusion coefficient ranged approximately from 2.084 × 10−12 to 3.015 × 10−12 m2/s. Temperature sensitivity of water diffusion coefficient increased (p < 0.05) with increasing brine concentration below 0.24 kg NaCl/kg. This temperature sensitivity was changed, decreased (p < 0.05) at brine concentrations equal or higher than 0.24 kg NaCl/kg. 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 = 0.909).