Measurement of Migration Rate of Water in Cured Tobacco Material

Abstract

The purpose of this study was to develop a model in which the migration rate of water in tobacco was expressed through the effective diffusion coefficient. The effective diffusion coefficients were calculated over a broad range of water content and temperature from the results of adsorption and desorption curves of water on tobacco. As a result, it was found that the migration of water could be macroscopically represented as one-dimensional diffusion in the thickness direction of tobacco. The effective diffusion coefficients obtained from the diffusion equation were strongly dependent on the water content and temperature. It was shown that the temperature dependence of the effective diffusion coefficients is expressed by Arrhenius equation. Consequently, it became possible to estimate the migration rate of the water at desired temperature and water content. Thus, one of the important factors in determining the processing conditions of tobacco has been clarified.