Diffusion kinetics and thermodynamics in pike eel salting

In order to know basic mechanism of salting process of pike eel, the kinetics and thermodynamics of sodium chloride diffusion were studied through the changes of salt content, moisture, weight and density of pike eel muscle during salting. Results show that there are good linear relationships between volume change and water loss of pike eel muscle, and between water loss and salt gain, the correlation coefficients are 0.998 and 0.994 respectively. The fitting correlation coefficients of water loss and salt gain along with time change are 0.992, the average relative deviation are 4.62% and 4.87% respectively. Experiments verified that the model was fit to salting process. The changes of volume, water content and salt concentration of pike eel muscle were an indication of salting time. The thermodynamics results indicate that salt diffusion coefficient is function of temperature and initial salt concentration. The magnitude of the activation energy is an indication of the temperature influencing on the diffusion process. The values of activation energy decrease with initial salt concentration increase. When the salt concentration in muscle decreases, temperature starts to be an important factor for accelerating the salting process.