Ginseng is a perennial herb of the genus Panax acanthaceae. The common name is a rare Chinese medicine with a long history of application, mainly distributed in the three provinces of Northeast China, mostly growing in deciduous, coniferous, broad-leaved mixed forests. Chinese medical books recorded its nicknames such as Renxian, Shencao, blood ginseng, etc., known as the "king of hundred herbs". Ginseng was first published in the Shennong Herbal Classic. It has sweet, bitter, mild, spleen and lung channel. It has the traditional effects of invigorating vitality, promoting fluid to quench thirst, invigorating spleen and lungs, and calming and enhancing wisdom. Li Shizhen said that its root is like a human form, called God grass.

There is also an ancient legend about ginseng, Changbai Mountain Tianchi is the largest mountain lake in Northeast China, but also one of the most beautiful places in the world, the water is crystal clear. Legend of the sky ginseng spirit fairy stole out to Tianchi bath, was seen by young Fu Sheng, produced love, so the Jade Emperor was banished to the earth. After living in the human world, the ginseng fairy shared the joys and sorrows with the people. In order to save the people in the disease and hardship, the fairy scattered ginseng seeds with his heart and blood to the mountains and forests. Since then, ginseng began to multiply and spread in the Changbai Mountain area.

The image of the ancients was very beautiful, but with the development of modern science and technology, people began to study ginseng scientifically from the perspective of molecular biology, revealing its secret under the mysterious veil. Through gene sequencing technology, scientists have analyzed the genome structure of ginseng, laying a foundation for in-depth exploration of the function of ginseng. At the same time, a variety of compounds beneficial to human health have been found in the study of active ingredients of ginseng.

Main active ingredients of ginseng:

Ginsenosides: ginsenosides Rg1, Rb2, Rc, Rg1, Rb1, etc. Saponins are the material basis of ginseng physiological activity. During the separation of aglycones, panaxenediol and panaxentriol are formed by the linkage of hydroxyl and ene in the molecular side chain due to the action of dilute acid. Both panaxenediol and panaxentriol are triterpenoid compounds.

Monosaccharides: glucose, fructose, sucrose, three trisugars: glucose-fructose-fructose, dextrose, glucose-glucose-fructose.

Organic acids and esters: citric acid, isocitric acid, fumaric acid, ketoglutaric acid, oleic acid, linoleic acid, malic acid, pyruvic acid, succinic acid, tartaric acid, panaxic acid, salicylic acid, vanillic acid, p-hydroxycinnamic acid, triglyceride, palmitic acid, triglyceride tripalmitate, α, γ-dipalmitate, triglyceride trioleate, glycoglycerin diester.
Vitamins: Vitamin B1, B2, B12, C; Niacin, folic acid, pantothenic acid, biotin and niacinamide.Sterols and their glycosides: β-sitosterol, stigmosterol, carotenosterol, canola sterol, ginsenoside P and ester sterol.

In addition, ginseng contains adenosine invertase, L-aspartase, β-amylase and sucrose invertase. Maltol, nonosane; Kaempferol, ginseng flavonoid glycosides and more than 20 trace elements such as copper, zinc, iron and manganese.

In the production process of ginseng products, extraction is a very important link, which not only directly affects the efficiency and benefit of production, but also has an important impact on product quality and efficacy.

1, solvent extraction method
The solvent extraction method usually uses water, acid and alkali as the solvent, and extracts the plant polysaccharides according to the principle of similar solubility according to the different physicochemical properties of the extracted plants. As one of the commonly used methods to extract plant polysaccharides, water extraction has the advantages of simple operation without changing the original physicochemical properties and biological activities of polysaccharides.

2. Microwave assisted method
Microwave assisted method uses microwave to enter the cell to make its polar substances absorb energy and expand, the pressure inside and outside the cell increases, and the substances in the cell accelerate dissolution under the action of electromagnetic waves.

3. Supercritical fluid extraction method
In the supercritical state, the utilized substance presents a fluid state that is neither gas nor liquid, and has high pressure and high density. The fluid has a high permeability similar to gas and a strong solubility for many substances. When it is near the critical point, the pressure and temperature change slightly, and the density will also change, which will cause changes in solubility, and then extract substances with different boiling points, polarity, and relative molecular mass.

4, rapid solvent extraction method
Fast solvent extraction technology is a fast sample pretreatment device dedicated to solid and semi-solid samples, the extraction time is a few minutes to tens of minutes, the solvent consumption is a few milliliters to tens of milliliters, the entire operation process is completely closed treatment, effectively reducing the volatilization of organic solvents, and laboratory personnel contact with organic steam time, environmental friendly, health and safety.

5. Flash extraction method
The flash extraction method is a method for extracting target components from plants by means of a flash extraction device. It has the advantages of short time consuming, high extraction efficiency, energy saving and simple operation. It can be operated at room temperature, and only the target plant tissues are physically broken without changing their chemical components during extraction. Therefore, compared with conventional extraction, flash extraction can preserve the active components of plants to the greatest extent. Moreover, the time consuming is short, the extraction efficiency is greatly improved, and it is expected to be a new method for preparing ginseng extract.

The chemical composition of ginseng is complex, including ginsenosides, ginseng polysaccharides, volatile oil, amino acids, flavonoids, vitamins, organic acids, sitosterols and trace elements. Saponins and polysaccharides are the main active components of ginseng, which have anti-oxidation and anti-aging effects. Flash extraction relies on violent vibration and rapid rotation, and then crushed the tissue of the medicinal materials. Under such conditions, the relative motion rate between the extraction solvent and the medicinal materials was accelerated, so that the boundary layer of the solution became thinner, and the dissolution rate of the effective components was effectively improved. As a new rapid extraction technology, flash extraction has high extraction efficiency, safe, simple and time-saving extraction process, and can retain the biological activity of active ingredients.

In summary, the flash extraction method is a better method to prepare ginseng extract, and can be widely used as a preparation method for ginseng extract.