Electrohydrodynamic drying of kiwi (Actinidia Chinensis) slices

Abstract

Electrohydrodynamic (EHD) enhanced drying of kiwi slices using multiple point-to-plate electrode arrangements under a DC voltage was carried out in an experiment to compare with those of oven drying at 60 ºC and ambient-air at 25 ºC. The EHD was run at high electric field of 375 V mm^-1 using thirteen ionizing needles to a plate electrode. The effects compared included drying rate, temperature, energy consumption, color, and shrinkage. Samples dried by the EHD and oven showed nearly the same values of moisture content whereas that of the air-dried sample was 3.5 times higher at the end of a 7-hour drying. The sample subjected to EHD preserved the same temperature during the drying. Compared with oven drying, EHD’s energy consumption was negligible. EHD and ambient-air drying rarely developed undesirable changes in color whereas the oven-dried sample color underwent a significant change in color. Finally, slices underwent almost the same final shrinkage in volume in both EHD and oven drying.