Sorption isotherms of lupine at different temperatures Original Research Article

Sorption isotherms of lupine at 25, 35, 45 °C were determined. Adsorption and desorption data were obtained at each temperature and no hysteresis was observed. The experimental method was a gravimetric static method. The results were fitted by the Guggenheim–Anderson–deBoer model. The monolayer moisture content (parameter of the model) was constant in the range of temperatures employed with a value of 0.0497 dry basis (d.b.). The isosteric heat of lupine was evaluated at several moisture content using the Clausius–Clapeyron equation and below a moisture content of 0.15 (d.b.) increases appreciably up to around 20 kJ/mol at very low moisture content.