The drying quality and energy consumption of Chinese wolfberry fruits under electrohydrodynamic system

Abstract

The aim of this work is to study the drying quality of Chinese wolfberry fruits and the effect of energy consumption on the drying process using electrohydrodynamic (EHD) drying. The drying rate, nutrient content and energy consumption of the Chinese wolfberry fruits which were dried in an EHD system at two levels of electric field intensity and five levels of the discharge gap were investigated and compared against oven drying and the control. The results showed that the drying rate have no significant difference at different voltages and discharge gaps under same electric field intensity. Experimentally, the polysaccharides content in the EHD system was improved when compared to oven drying. The specific energy consumption decreased with the decrease of the discharge gap and voltage. The drying rate can be enhanced and the energy consumption was greatly reduced at lower discharge gap and voltage in EHD system. The effect of degree of cell damage is smaller during EHD drying. Therefore, this work provides guidance for optimizing and improving the drying efficiency of Chinese wolfberry fruits in an EHD system.

Electrohydrodynamic Drying of Chinese Wolfberry in a Multiple Needle-to-Plate Electrode System

“…Dinani et al found that the rehydration capacity of mushroom slices with EHD treatment was significantly higher than that of the oven dried at 60 °C, but the shear strength was lower than that of the oven dried at 60 °C [17]. We found that the drying rate of the Chinese wolfberry with EHD treatment was notably greater than that of the control in previous research [18,19]. Compared with the wire-to-plate and plate-to-plate electrode systems, a needle-to-plate electrode configuration had the highest drying rate, and the active ingredient was preserved well [18,19].…”

“…We found that the drying rate of the Chinese wolfberry with EHD treatment was notably greater than that of the control in previous research [18,19]. Compared with the wire-to-plate and plate-to-plate electrode systems, a needle-to-plate electrode configuration had the highest drying rate, and the active ingredient was preserved well [18,19]. Multiple mathematical models can be used to describe the drying characteristics of Chinese wolfberry with EHD treatment, but the best models are slightly different under different drying conditions [18,19].…”

“…Compared with the wire-to-plate and plate-to-plate electrode systems, a needle-to-plate electrode configuration had the highest drying rate, and the active ingredient was preserved well [18,19]. Multiple mathematical models can be used to describe the drying characteristics of Chinese wolfberry with EHD treatment, but the best models are slightly different under different drying conditions [18,19]. Many experimental results in recent years indicated that the performance of EHD-enhanced drying was influenced by factors such as geometric characteristics, needle spacing, gap distance, applied voltage, and surface characteristics of materials under the drying process [20,21,22,23].…”

Infrared Spectrum Analysis of Goji Berry during Electrohydrodynamic Drying

“…It shows that the needle spacing can have a certain influence on the active ingredients inside the goji berry during the drying process. Yang et al reported that, compared with the hot-air drying, the polysaccharide content of goji berry dried electrohydrodynamically significantly increased [18]. Song et al found that under freeze-drying process, the flavonoid content of goji berry using distilled water pretreatment was much higher than that of sodium carbonate [26].…”

“…Bai et al dried the sea cucumber using electrohydrodynamic drying and found that the energy consumption under electrohydrodynamic drying is only 21.31% of the hot-air drying and the protein content is higher than that of the hot-air drying [16]. Previously, we used the electrohydrodynamic drying to dry the goji berry and achieved very satisfactory results [17,18].…”