Salt diffusivities and salt diffusion in farmed Atlantic salmon muscle as influenced by rigor mortis Original Research Article

Salt infusion in farmed Atlantic salmon muscle as affected by rigor mortis during salting was investigated. A finite-difference model was developed to determine the salt diffusivity and to simulate salt infusion in the salmon muscle. Experiments verified that the model gave good fits for pre-rigor, in-rigor and post-rigor states. Salt diffusivities in the Atlantic salmon muscle were determined to be (8.77+0.88C)×10−11, (0.23+4.81C)×10−10 and (1.08+0.59C)×10−10 m2/s (at 10°C) for pre-rigor, in-rigor and post-rigor fish, respectively; where C is the salt concentration (g/g salt-free solids) in the muscle. Simulation results revealed that the pre-rigor salmon had the lowest salt concentration when compared with in-rigor and post-rigor salmon after the same salting time. Salt distribution inside the salmon samples was less uniform than in-rigor and post-rigor fish. The equilibrium salt concentrations had a significant impact on the concentration profile for the in-rigor salmon fillets.