Peanut hull (peanut pods and waste materials from processing of peanuts) was pelleted through a 3/16-in. (4.76 mm) diameter die. The effect of change in moisture content (4.2-21.2%, wet basis) of the pellets (due to exposure of the pellets to low or high humidity storage environments) on physical properties were measured. Pelleting increased the bulk density of the peanut hull from 151 kg/m(3) to more than 600 kg/m(3). Bulk density, particle density and durability of the pelleted peanut hull of pellets were significantly affected by moisture content attained by the pellets during exposure to the low or high humidity environment. Air relative humidity significantly influenced the rate at which the pellets exchange moisture with the environment while air temperature did not. The values of the constants of the GAB model were obtained from moisture sorption isotherm at 25 degrees C. (c) 2007 Published by Elsevier Ltd.