Moisture sorption isotherms of vacuum dried
coconut presscake were determined at 25 °C, 30 °C, and
38 °C using a gravimetric technique. Sorption isotherms
exhibited Type II behaviour. The effect of temperature on
equilibrium moisture content was not significant (p>0.05).
Three models available in the literature viz., GAB, BET,
and Halsey models were fitted to the sorption data. Out of
the three tested models, Halsey model best fitted the
experimental data with a relative deviation percent below
10%. The net isosteric heat of sorption was determined
from the equilibrium adsorption data using the Clausius–
Clapeyron equation. Isosteric heats of sorption were found
to decrease exponentially with increasing moisture content.