Electrohydrodynamic Drying Technology for Heat Sensitive Foods

Abstract

Electrohydrodynamic (EHD) drying refers to the removal of water from a wet material exposed to a strong electric field due to the aerodynamic action of so-called "ionic" or “corona” wind. This action disturbs the gas boundary layer at the material interface, decreasing convective mass transfer resistance and promoting convective mass transfer from the material. The advantage of EHD technology is the direct use of electric energy for water evaporation at ambient temperature, and therefore it could be used for drying heat-sensitive foods. Due to zero heat generation, the energy consumption of EHD drying is very low, about 20-25 times smaller than equivalent thermal drying. Lab-scale research confirmed multiple benefits of this innovative technology, such as high drying rate, high energy efficiency, premium product quality, no GHG emissions, and low capital and operational costs. This paper contributes to the application of innovative EHD drying in combination with other drying technologies to improve the overall efficiency of heat-sensitive food drying. This application is illustrated with the experimental results of EHD drying of apple slices. The clean and eco-friendly nature of EHD technology in conjunction with premium product quality makes it a good alternative for future food engineering.