Abstract
Apparent diffusion coefficients of sodium chloride in fish meats, Dapp' were estimated from the amount of the salt absorbed when the salt was sprinkled on the outer skin or inner meat side of fish filets. A fish filet was assumed to be a plate with an infinite depth. The Dapp values were in a relatively narrow range of 10-7 to 10-6 cm2/s when the salt was sprinkled on the inner meat side of filet. On the other hand, when the salt was sprinkled on the skin side of filet, the Dapp values were in a range of 10-9 to-6 cm2/s and were greatly dependent of both the kind and the individual of fish. In the latter case, there seemed to be three diffusional resistances in series, that is, the skin, subcutaneous fat, and meat layers. Regarding the skin and subcutaneous fat layers as a layer, the diffusion coefficient of the salt in the layer, Ds' was evaluated under some assumptions. The Ds values were very small, and between 10-10 and 10-8 cm2/s.
A correlation between water and fat contents was also made using the contents of fifty-five samples. The logarithmic value of fat content was empirically expressed by the quadratic equation of water content.
