Moisture sorption isotherms of walnut flour at several temperatures

Abstract

Moisture equilibrium data (adsorption and desorption) of walnut flour were determined using the static gravimetric method of saturated salt solutions at three temperatures 10, 25, and 40 °C. The range of water activities for each temperature was between 0.11 to 0.85. Equilibrium moisture content decreased with the increase in storage temperature at any given water activity. The experimental data were fitted to four mathematical models (modified Oswin, modified Halsey, modified Chung-Pfost and modified Henderson). The monolayer moisture content was estimated from sorption data using the Brunauer-Emmett-Teller (BET) equation. The isosteric heats of sorption were evaluated using Clausius-Clapeyron equation. © 2004 Taylor and Francis Group, LLC.