Exploring the sorption and thermodynamic proprieties of white truffle (Terfezia boudieri)

AbstractIn this work the sorption behavior of Terfezia boudieri truffle was studied and evaluated using the static gravimetric method. This approach permits the measurement of the sorption isotherms at three given temperatures 30, 40, and 50°C. Where in the first step experimental sorption data was collected, and then was used in order to identify the thermodynamic properties of truffle. Several results were found by conducting this study. First, the optimal water activity (aw) for conserving T. boudieri truffles was determined and found to be in range of the values 0.24 and 0.31 as a function of temperature. Additionally, net isosteric heat and entropy of sorption, which are two parameters studied during this study, were found to be decreasing when the water content increased; where the existence of the compensation theory of enthalpy–entropy for Terfezia boudieri was confirmed. Second, net isosteric heat and entropy of sorption, which are two parameters studied during this study, were found to be decreasing when the water content increased; where the existence of the compensation theory of enthalpy–entropy for Terfezia boudieri was confirmed. Finally, the isokinetic temperatures were 338.69 and 324.35 K for desorption and adsorption, respectively. As well as the free Gibbs energy was found to be positive for sorption which indicates that the sorption process as a non‐spontaneous one. Moreover, the spreading pressure varied in a range of 0.03–0.25 J/m2, while the aw increased. This study is a contribution to the drying, packaging, and conservation of white truffle.Practical applicationsWhite truffle has been widely used in many food products related applications, and pharmaceutic industry. White truffle is only available in certain seasons; consequently its storage process for long periods is a necessity in order to ensure the supply chain over the year. Furthermore, this particular food product needs a very specific storage conditions which may affect its quality and shelf‐life. This work aimed to determine and evaluate the water sorption properties in an adequate range of temperature and relative humidity. The mathematical models and the thermodynamic analysis conducted throughout this study, in addition to the reported data are useful to find the optimal and adequate storage conditions to preserve the quality and prolong the white truffle shelf‐life.