Equilibrium isotherms and isosteric heats of morel (Morchella esculenta) Original Research Article

Moisture desorption isotherms of Morchella esculenta mushrooms were determined at 5, 15, 25 and 35 °C and within the range of 0.11–0.92 water activity using a standardized conductivity hygrometer. Five models were considered to describe isotherms (GAB, Oswin modified, Henderson modified, Halsey modified and Ratti) being fitted to the experimental data by direct non-linear regression. The GAB and Ratti equations gave the best fit of the experimental data. Isosteric heats of water desorption were obtained from the experimental data by applying the Clausius–Clapeyron equation within the range of 0.04–0.50 moisture content (dry basis).