Influence of the electrohydrodynamic process on the properties of dried button mushroom slices: A differential scanning calorimetry (DSC) study

In this paper, drying of button mushroom (Agaricus bisporus) slices with an innovative drying technique of hot air combined with Electrohydrodynamic (EHD) drying process was investigated at three electrode gaps (5, 6, and 7 cm) and voltage levels (17, 19, and 21 kV). The effects of different hot air combined with EHD drying treatments on the temperature of the mushroom slices, drying time, final color and protein denaturation features including enthalpy (Delta H), onset temperature (T-o), peak transition temperature (T-p), conclusion temperature (T-c), and temperature range (T-c-T-o) of endothermic peaks were systematically evaluated. In addition, water state changes in DSC cooling thermograms of dried mushroom slices were investigated. The results obtained by differential scanning calorimetry showed that the Delta H values in the DSC traces of the EHD-dried mushroom slices were reduced with a decrease in the electrode gap and an increase in the voltage. Specifically, among voltages of 21, 17, and 19 kV, a voltage of 21 kV resulted in the lowest Delta H and T-c-T-o values and the highest T-p and T-o values. This result indicated that voltage had a significant effect on these responses. Similarly, the DSC results showed a considerable effect of high electric field intensity on Delta H, T-c-T-o and T-p responses related to protein denaturation in comparison to low electric field intensity. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.