Abstract
The diffusion coefficient and change in NaCl concentration of root vegetables during cooking were studied. Japanese radish, carrot and potato cut in 2-cm cubes were soaked in a 0.2 M brine solution at 20, 50 and 70°C for 16, 8 and 6 hrs, respectively, for measuring the NaCl diffusion coefficient. The value for the diffusion coefficient of NaCl was in the order of Japanese radish, carrot and potato, suggesting that vegetables obtaining more water had higher diffusion coefficient. The diffusion coefficient of a 2-cm cube of radish soaked in 0.2-0.8 M brine solutions showed little dependence on the concentration of brine solution. The predicted and experimental values for the average NaCl concentration of each volume element agreed with each other when using the obtained diffusion coefficient under different temperature, brine concentration and time conditions. It was possible to predict the average or distribution in concentration of NaCl of a sample treated as a set of 1 mm3 of volume element by using the finite difference equation.
