Electrohydrodynamic Drying—A Concise Overview

Abstract

Electrohydrodynamic (EHD) drying is a novel method of non-thermal processing. The drying can be carried out using either AC or DC high voltages. The thermodynamic considerations regarding the lowering of temperature under EHD drying include rapid rates of evaporation and exothermic interaction of the electric field with a dielectric material. Multi-point and plate electrode systems are efficient in accelerating drying of agricultural materials. Compared to hot air (convective) drying systems, EHD drying systems offer lower food production costs along with superior quality in terms of physiochemical properties such as color, shrinkage, flavor, and nutrient content. Compared to convective and freeze-drying, EHD drying systems, given their simpler design and lesser energy consumption, show great potential for bulk and industrial drying applications.

Keywords:

• Air ions
• Corona current
• Drying rate
• Non-thermal drying
• Rehydration
• Shrinkage

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the financial support from Natural Sciences and Engineering Research Council (NSERC) and Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT).

Notes

^a Shimadzu LC-10AS chromatograph equipped with a Shodex SC-125S column, size, 4.6 mm × 500 mm; mobile phase, 0.1% H₃PO₄, flow rate, 0.3 ml/min; column temperature, 55°C; detector, Shimadzu SPD-6A at 210 nm; recorder, Shimadzu Chromatopack C-R4A.

^b Shimadzu SCL-10 chromatograph equipped with a Shim-pack CLC-NH₂(M) column; size, 6.0 mm × 150 mm; mobile phase, 70% CH₃CN; flow rate, 0.3 ml/min; column temperature, 40°C, detector, Shimadzu SPD-6A at 192 nm; recorder, Shimadzu Chromatopack C-R8A.