SORPTION ISOTHERMS AND THERMODYNAMIC PROPERTIES OF POWDERED MILK

Moisture sorption isotherms of powdered milk were obtained using the gravimetric static method at 30 degrees, 40 degrees, and 50 degrees C. Peleg and Enderby equations were found to be the most suitable models for describing the sorption curves among six well-known tested equations. Thermodynamic properties such as differential enthalpy and entropy of sorption were determined from moisture adsorption and desorption data, using the Clausius-Clapeyron equation. The experimental data showed that enthalpy-entropy compensation theory was applicable to the moisture sorption behavior of powdered milk.