Equilibrium Moisture-Equilibrium Relative Humidity Relationship for Canola Meal

Abstract

ABSTRACT THE desorption isotherms of canola meal were measured by bringing a small amount of air to equilibrium with the canola meal sample in a closed loop experimental unit. The equilibrium relative humidities (ERH) were measured for the canola meal samples at 5.0, 7.5, 10.0, 12.5, 15.0 and 17.5% moisture contents wet basis (wb) and 10, 20, 30, 40 and 50C temperatures. The effect of temperature on the ERH was minimal at the moisture contents below 15% wb. At higher moisture contents, increase in the temperature resulted in a noticeable increase in the equilibrium relative humidity. A non-linear regression was performed to estimate the constants of the modified Henderson and the Chung-Pfost equations. At moisture contents of 5% wet basis, neither equation described the equilibrium relative humidity with accuracy. The modified Henderson equation described the data better in the humidity range from 20% to 80%.