AN EMPIRICAL-MODEL FOR THE DESCRIPTION OF MOISTURE SORPTION CURVES

Published sorption curves in the form of moisture vs. time relationships of milk powder and rice, exposed to moist atmosphere or soaked in water, were fitted by a two parameter, nonexponential empirical model. The model enabled prediction of moisture contents after long exposure from experimental data obtained in relatively short time, i.e., well before the moisture level appeared to reach a plateu. The model implied that the moisture equilibrium was somewhat higher than that determined on the assumption that the sample reached a constant weight, but there was no conclusive evidence that this was really the case.