A review on electrohydrodynamic drying- A novel non-thermal drying technique

The recent COVID pandemic has contributed to the shift in consumer preferences towards high-quality products, while industries seek low-energy technologies with minimal greenhouse gas emissions. To address these demands, this review explores electrohydrodynamic (EHD) drying, a non-thermal drying process that uses significantly less energy than traditional methods. In EHD drying, a high-voltage supply between two electrodes creates a corona wind that rapidly dries food products placed on a grounded electrode. The energy used during drying is much less than the latent heat of vaporization, indicating water removal by the process of corona discharge and not by evaporation. This technology offers several advantages, including reduced drying times, increased heat and mass transfer rates, and improved product quality. This paper provides a comprehensive review of EHD drying, examining the effects of various factors like voltage supply, types of electrodes, material of construction of electrodes, distance between the electrodes, number of needles and its sharpness, wire type electrodes, shape of electrodes etc. on drying rates, rehydration ratio, and product quality. The review suggests that EHD drying is an ideal solution for heat-sensitive products, involving a multidisciplinary approach to food processing.