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Determination of Salt Diffusivity into the Potato Tissues

Introduction: Theoretical calculations of diffusivity into the solids are subjected to a lot of limitations. Consequently in most researches related to the molecular diffusion into the solids and foods, the effective diffusivities are measured by laboratory methods. In this research the effective diffusivity of salt into the potato tissues was measured experimentally applying analytical solution of Fickʹs equations in mass transfer. Materials and Methods: The cylindrical samples of potato with 3 cm diameter and 3.5 cm height were immersed into the brine. The surrounding surfaces of the samples were covered by a suitable sealant in order to consider one dimensional mass transfer. Variations in brine concentration and consequently the rate of salt diffusion into the potatoes were calculated by measuring the electrical conductivity of brine. / 1 c_ f Results: The diffusivity of salt into the potato tissues is increased by increase in brine concentrations, but it wonʹt be remarkable increase at high brine concentrations. The salt / concentration in potato tissues reaches to equilibrium in 300 min and then no more diffusion will be occurred. Using the results of experiments and analytical solution of Fickʹs law equations the diffusivity of salt into the potato tissues at 24 °C were measured to be (3.45¬4.39) 10-9xm2/s for 1-3% (w/v) brine solutions. Conclusion: According to the results of this research, Fickʹs law equations in mass transfer and their analytical solutions represented by Crank give a precise explanation of mass transfer in solids. Furthermore, the diffusivity of salt in the potato is independent of the £ variety of potato and consequently different researches have concluded similar results. ʹj^ Keywords: Brine, Crank Equation, Diffusivity, Potato