There are many kinds of Chinese medicinal materials with different characteristics and properties, so the appropriate parameters such as drying temperature, humidity and time should be selected according to their characteristics, such as aromatic Chinese medicinal materials such as mint, woody, bergamot, orange peel, etc. Fragrance is important, so the temperature should not be too high, otherwise the fragrance will be lost and the color will be dark. It should be dried at medium and low temperature.
Viscous Chinese herbal medicines are rich in viscous sugars, which are sticky after being sliced, such as Yuzhu, Tiandong, and Chinese yam. In order to ensure that the juice inside does not leak out, they should be dried at a relatively high temperature. Especially yams, which have high starch content, tend to become brittle and broken after drying. Pay attention to drying them in time after slicing or processing, otherwise they will easily deteriorate.
Oily Chinese herbal medicines, such as angelica, citrus aurantium, cinnamon, and achyranthes bidentata, the volatile oil contained in these Chinese herbal medicines is extremely sensitive to temperature. When the temperature is too high, the oil will overflow the surface and easily decompose and deteriorate. Therefore, it is advisable to dry at medium and low temperature during drying to prevent oil leakage or blackening of color, so as to better protect the medicinal ingredients.
The color and luster of Chinese medicinal materials such as ginseng slices, astragalus, platycodon, Alisma, honeysuckle, safflower, chrysanthemum, etc., the color and appearance after drying is a very important factor for the quality of this type of Chinese medicinal materials, so it cannot be dried at high temperature. Drying, pay attention to the slow temperature rise at medium and low temperatures, so that the Chinese herbal medicines can evenly absorb the heat of the air in the drying room and release moisture.
Drying temperature control:
The most important thing for Chinese medicinal materials is the effective preservation of nutritional and medicinal ingredients, and medicinal materials have certain range requirements in terms of temperature. The level of drying temperature directly determines the degree of preservation of the index components of Chinese herbal medicine tablets. Too high or too low temperature will have adverse effects on the quality of medicinal materials: when the temperature is too high, lipid-containing Chinese medicinal materials will overheat and lose their oil quality, and Chinese medicinal materials containing volatile oil will lose their aroma when overheated. When the temperature is too low, it is easy to cause the medicinal materials to dry too slowly or not dry enough to cause mold or insects. Therefore, choosing an appropriate drying temperature based on the characteristics of different Chinese medicinal materials can play a positive role in the preservation of the medicinal properties of Chinese medicinal materials, their appearance and later storage of medicinal materials.
For general Chinese herbal medicines or Chinese medicinal materials containing volatile oil, the appropriate range is 45-65°C, for juicy fruit medicinal materials, the appropriate range is 65-90°C, for mosaic leaves, 20-45°C is better, and for rhizomes, the appropriate temperature range The range of 30-65°C is suitable. Typical drying temperature settings such as bergamot, set the temperature at about 55°C to 65°C, so that a production batch can be dried every twelve to fifteen hours, and the quality is good, clean and hygienic.
Control of drying humidity:
When the hot air flows over the surface of the Chinese herbal medicine evenly and stably, a heat transfer driving force is formed between the hot air at a higher temperature and the Chinese herbal medicine at a lower temperature, and the air transfers the heat to the Chinese medicine to be dried by convection. Therefore, when the Chinese herbal medicine is heated and the moisture in it is gasified away, this is the dehumidification process of the air source heat pump for drying the Chinese herbal medicine, and the initial moisture content of each medicinal material is different, so the drying process There are also requirements for the size of the moisture removal. For example, in the drying of wolfberry, the water content of fresh fruit is as high as 80%, but in the initial heating stage, it cannot dehumidify, and in the second stage when the temperature is 45 ℃, it needs a lot of dehumidification, and then slightly adjust the dehumidification until The final uniform dehumidification went through four stages of different temperature and humidity settings for a total of about 25 hours, and a whole batch of high-quality wolfberry was obtained, and the drying process was large, saving energy.