Measurement of the Adsorption Equilibrium Moisture Content of Polished Rice

Effect of Initial Moisture Content on the Adsorption Equilibrium Moisture Content

Abstract

The moisture adsorption properties of polished rice were investigated using a dynamic ventilatory method. Air temperatures of 10, 20, 30 and 40°C, and relative humilities of 50, 60, 70, 80 and 90%RH were used to obtain sorption coefficient and equilibrium moisture content data. Air velocity was kept constant at 32.4m/min for all the measurements. Equilibrium moisture content of polished rice was fitted with the Chen-Clayton's equation by using a special method of solution for the non-linear least squares method. The results revealed that the equilibrium moisture content depends on initial moisture content, and this can be supposed as an effect of hysteresis.