Evaluation of Energy Consumption and Quality of Plasma Synergistic Drying of Codonopsis Pilosulae

Drying as a key link in the processing of Chinese herbal medicines, drying quality directly affects the finished products of Chinese herbal medicines. Traditional hot air drying technology has the disadvantages of high energy consumption and easy browning of heat-sensitive components. Plasma drying is characterized by low energy consumption, low pollution, and high retention of medicinal ingredients, and is regarded as a non-thermal drying technology with application prospects. In this paper, plasma technology was applied to the drying treatment of slices of Radix et Rhizoma Ginseng, comparing the drying effects of different drying methods, analyzing the differences in the color and luster of Radix et Rhizoma Ginseng after hot-air drying and synergistic drying with plasma, determining the specific energy consumption of the different drying methods, and determining the content of kynurenine of Radix et Rhizoma Ginseng in the dried samples by using high performance liquid chromatography. The results showed that the plasma drying of the slices belonged to the descending-rate drying process, and there were obvious differences in the drying rate and final moisture content between the different synergistic drying methods; compared with the hot-air-dried herbs, the plasma-dried slices of Codonopsis pilosula were lighter in color and had no obvious browning. The plasma and synergistic drying processes significantly increased the content of ginsenosides in the herbs, while the energy consumption was significantly reduced.