Effects of Porosity and Thermal Treatment on Hydration of Mushrooms

In this study, hydration of mushroom as a porous food material has been studied considering their biphasic character. It consists of a solid phase that consists of intertwined hyphae and having cell walls with a swellable polymeric matrix and a pore phase made up by the space in between the hyphae. We have investigated the hydration of mushrooms as a function of initial porosity and thermal treatment. Variation in porosity is induced by the natural variation in the growth of mushroom. Porosity is measured by the weight gain during vacuum infiltration of mushroom caps with the mushroom isotonic solution. The hydration of the heat-treated mushroom shows a linear increase with the porosity of mushroom. Storage of mushroom increases the porosity with the number of storage days, which has also been confirmed with X-ray tomography(XRT) measurements. Finally, we show that the hydration of thermal-treated mushroom has two independent contributions, from porosity and temperature of the heat treatment. Current theories deal only with the latter contribution to the hydration of foods and need to be extended for accounting porosity of the food.</p