? Drying Chinese herbal medicines in time to ensure quality

The practice of Chinese herbal medicine warehouse storage proves that

if the water content of Chinese herbal medicine is controlled within a certain limit under certain conditions

the quality will not change. For example, when the temperature is 3℃ in the north

the water content of jujube is controlled at 12%-17%, codonopsis pilosula is 11%-16%, bitter almond is 6%-8%, Glehnia littoralis is 12%-15%, and Astragalus membranaceus is 11%-14%

, the quality will change during storage. This is the so-called "safety" of Chinese herbal medicines. Therefore, the harvested and processed Chinese herbal medicines must be dried to the safe moisture limit < P > in time to ensure the quality of Chinese herbal medicines.

At present, there are several common drying techniques for Chinese medicinal materials:

Sunlight method, which is a common drying method for most Chinese medicinal materials. When drying,

You should choose sunny and windy weather

Spread the medicinal materials thinly on a reed mat or concrete floor

Use sunlight to illuminate

At the same time, you should pay attention to turning them in time

To ensure uniform sunlight. At night after autumn, the air humidity is

high

. Pay attention to put away the medicinal materials and cover them

to prevent moisture regain.

spread drying method, which is also called shade drying method

that is, the medicinal materials are placed indoors or in a cool place in a greenhouse

the water is blown away by flowing air to achieve the purpose of drying. This method is often used in rainy weather, or for medicinal materials containing volatile oil, such as jujube seed, platycladi seed, Anemarrhena asphodeloides, bitter almond, codonopsis pilosula, asparagus root, hemp seed and so on. These medicinal materials should not be exposed to the sun, but can be spread in places with weak sunlight or ventilated and cool places to avoid oil and deterioration.

Kang drying method This method is a traditional, simple and economical method for drying medicinal materials. To apply this method, it is necessary to build one or several rectangular fire-resistant kang indoors or in a greenhouse in advance.

The width of the fire-resistant kang is about 1.5 meters.

The length can be determined according to the number of medicinal materials.

A small door that can be opened and closed every 8 cm is left under the fire-resistant kang to add fuel. Then put a stove in it.

An iron plate should be placed at the mouth of the stove to prevent the flame from rising. Destroy medicinal materials, but also disperse heat. When the kang is 1.2-1.5 meters high, put a round steel pipe with a diameter of 3-4 cm horizontally every 6 cm, lay a wire mesh on the steel pipe, and then cover it with mud, and then raise the kang 6 cm above the mud. Finally, light the stove, dry the kang and the mud covered with it, and put the medicinal materials in the kang trough according to the level of first big and then small, but don't fill it too full, and it is advisable to cover it with sacks and straw curtains with a thickness of 3-4 cm < P >. When a large amount of steam rises,

open the sack or straw curtain in time

and pay attention to turning the medicinal materials up and down until the kang is dry. This method is suitable for drying Rhizoma Chuanxiong, Rhizoma Alismatis and Radix Platycodi. During the drying process, attention should be paid to mastering the heat

so as not to scorch the medicinal materials

. Some medicinal materials should be treated separately according to the nature of the medicinal materials and the requirements for drying degree

.

drying method of drying room and dryer This method is suitable for large-scale medicinal material planting bases, and it is efficient, labor-saving and cost-saving. It is not limited by the weather, but also has the effect of killing insects and driving mold. The temperature is controllable, which is suitable for all kinds of medicinal materials and does not affect the quality of medicinal materials. It is an advanced drying method. However, it should be noted that the drying room should be built according to the technical requirements and standards of the specifications and special drying machinery should be purchased, which should be operated by professionals familiar with drying technology. In addition, we should pay attention to control the drying temperature and time according to the different properties of medicinal materials.

Far-infrared heating drying method This is a new drying technology, and its drying principle is to convert electric energy into far-infrared radiation

so that it is absorbed by the molecules of medicinal materials

to generate * * * vibration

to cause the vibration and rotation of molecules and atoms

to make the object hot

to achieve the purpose of: R drying through thermal diffusion, evaporation and chemical changes

. This method can be used to dry seeds, fruits and rice. Far-infrared drying can save 2%-5% of electric energy < P >.

microwave drying is a new technology developed rapidly in 196s. In fact, microwave drying is to make the water and fat in Chinese herbal medicines absorb microwave energy to varying degrees through induction heating and medium heating, and convert it into heat, so as to achieve the purpose of drying. Microwave drying can kill microorganisms and molds

and has a disinfection effect

so that the medicinal materials can meet the hygiene standards, and can prevent the medicinal materials from mildew and insects during storage. At present, the complete microwave heating equipment produced in China has two frequencies: 915mhz and 245mhz.