Mushrooms dehydration in a hybrid-solar dryer, using a phase change material

Mushrooms were dehydrated in a hybrid solar dryer provided with a solar panel of a total exposed surface of 10 m2, electric resistances and paraffin wax as a phase change material. Mushrooms were cut in 8 mm or 12 mm slices. At the outlet of the drying chamber the air was recycled (70% or 80%) and the air temperature was adjusted to 60 °C. At the outlet of the solar panel the air temperature rose up to 30 °C above the ambient temperature, depending on solar radiation level. fective diffusivity, estimated by the Simplified Constant Diffusivity Model, considering or not shrinkage, fluctuated between 2.5 · 10−10 m2/s and 8.4 · 10−10 m2/s with R2 higher than 0.99, agreeing with values reported in literature. The empirical Page’s model resulted in a better adjustment, with R2 above 0.998. runs the dehydrated mushrooms showed a notorious darkening and shrinkage. Rehydration assays at 30 °C showed that in less than 30 min rehydrated mushrooms reached a moisture content of 1.91 (dry basis). Rehydrated mushrooms had a higher hardness compared with fresh mushrooms. The Simplified Constant Diffusivity Model and the Peleg’s model adjusted to the rehydration data with RMSE values below 0.080. l efficiency fluctuated between 22% and 62%, while the efficiency of the accumulator panel varied between 10% and 21%. The accumulator allowed reducing the electric energy input.