Effect of temperature and relative humidity on drying kinetics of fresh Japanese noodle (udon)

Abstract

The effects of temperature and relative humidity (RH) on the drying kinetics were investigated to identify the optimal drying conditions for Japanese noodle (udon). Drying of fresh udon was carried out under nine conditions involving three temperatures (20, 30 and 40°C) and three RHs (60, 70 and 80%) at a constant airflow. The apparent moisture diffusivities were determined using a diffusion model taking into account both the internal and external mass transfer resistances. The effect of RH on the apparent moisture diffusivity was found to be smaller than that of temperature, but could not be neglected. A modified Arrhenius-type equation of diffusivity involving a RH term was proposed and used for the calculation of moisture content with time. The proposed equation was fund to be effective for representing the drying process of fresh udon. © 2002 Elsevier Science Ltd. All rights reserved.