Extraction process of centella asiatica essence

Abstract

The invention relates to the technical field of plant essence extraction processes, in particular to an extraction process of centella asiatica essence, which specifically comprises the following steps: S1, cleaning centella asiatica by using ultrasonic cleaning equipment to remove impurities, and drying the cleaned centella asiatica; step S2, crushing the centella asiatica; s3, putting the crushed centella asiatica and supercritical carbon dioxide into an extraction kettle, and performing static extraction and dynamic extraction to obtain supercritical fluid; s4, the supercritical fluid is fed into a separation kettle, the fluid is recovered to the normal state, centella asiatica essence and carbon dioxide are separated out, and S5, the carbon dioxide separated out in the step S4 is fed into a compressor to be recycled. According to the extraction process, loss of effective components can be reduced as much as possible in the extraction process, the essence quality is ensured, the extraction process is environment-friendly and non-toxic, the extraction agent can be recycled, and the cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of centella asiatica extraction, in particular to a process for extracting centella asiatica essence. Background Art

[0002] Centella asiatica is a perennial herb with creeping, slender stems and roots at the nodes. The leaves are membranous to herbaceous, round, kidney-shaped or horseshoe-shaped; the palmate veins are 5-7, raised on both sides, and bifurcated above the veins; the petiole is 1.5-27 cm long, glabrous or pubescent on the upper part, and the leaf sheath at the base is transparent and membranous. The umbels are 2-4, clustered in the axils of the leaves; the bracts are usually 2, rarely 3, ovate, and membranous; each umbel has 3-4 flowers, which are clustered in a head shape; the petals are ovate, purple-red or milky white, and membranous; the style is about 0.6 mm long; the filaments are shorter than the petals and are the same length as the style. The fruit is flattened on both sides, spherical, with a heart-shaped to truncated base, with several longitudinal ridges on each side, and obvious small transverse veins between the ridges, reticulate, and the surface is hairy or smooth. The flowering and fruiting period is from April to October. It is easy to propagate and cultivate, and the price is low. It has the effects of clearing heat and dampness, detoxifying and reducing swelling.

[0003] The clarity and purity of the Centella asiatica extract extracted by the existing extraction process are not high enough, and some chemical components are used in the extraction process, which are harmful to a certain extent and easily cause environmental pollution.

[0004] Therefore, it is necessary to design an extraction process with higher purity, greater environmental protection and safety. Summary of the invention

[0005] In order to solve the above problems, the present invention provides an extraction process for Centella asiatica essence, which adopts supercritical carbon dioxide extraction. The clarity and purity of Centella asiatica essence are higher, and some raw materials used in the extraction process can be recycled, reducing the extraction cost.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A process for extracting Centella asiatica essence, comprising the following steps: Step S1, cleaning and removing impurities from the Centella asiatica with an ultrasonic cleaning device, and drying the Centella asiatica after cleaning; Step S2, crushing the Centella asiatica; Step S3, placing the crushed Centella asiatica and supercritical carbon dioxide in an extraction kettle, performing static extraction and dynamic extraction to obtain a supercritical fluid; Step S4, sending the supercritical fluid into a separation kettle to restore the fluid to normal state, and separating the Centella asiatica essence and carbon dioxide; Step S5, sending the carbon dioxide separated in step S4 to a compressor for recycling and reuse.

[0007] Optionally, in one embodiment of the present invention, the drying treatment in step S1 is to control the moisture content of Centella asiatica to below 10%, and the drying treatment is carried out by either low-temperature drying or vacuum drying.

[0008] Optionally, in one embodiment of the present invention, the crushing process in step S2 is to crush the Centella asiatica into a size of 80-100 mesh.

[0009] Optionally, in one embodiment of the present invention, 10% ethanol is also added as an entrainer in the dynamic extraction of step S3.

[0010] Optionally, in one embodiment of the present invention, the extraction temperature of step S3 is 60° C. and the extraction pressure is 30 MPa.

[0011] Optionally, in one embodiment of the present invention, the static extraction time is 1.5 hours and the dynamic extraction time is 6 hours.

[0012] Optionally, in one embodiment of the present invention, the process further includes purifying the Centella asiatica extract extracted in step S4.

[0013] Beneficial effects of the present invention The invention discloses a process for extracting Centella asiatica essence, which uses ultrasonic cleaning and low-temperature drying or vacuum drying to ensure that the effective components in the Centella asiatica are not lost as much as possible. During the extraction, supercritical carbon dioxide is used for extraction, so that the Centella asiatica will not be oxidized and is pure and natural without chemical pollution. The generated carbon dioxide can be recycled, thereby reducing environmental pollution and achieving high extraction efficiency. The extracted Centella asiatica essence is then purified, thereby further improving the clarity and purity of the Centella asiatica essence. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0015] Figure 1 A schematic diagram of the process flow of Example 1 of the present invention; DETAILED DESCRIPTION

[0016] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments. Example 1

[0017] In order to achieve efficient extraction of Centella asiatica essence and improve process environmental protection, a Centella asiatica essence extraction process was designed. The specific scheme is as follows: A process for extracting Centella asiatica essence, comprising the following steps: Step S1, cleaning and removing impurities from the Centella asiatica with an ultrasonic cleaning device, and drying the Centella asiatica after cleaning; Step S2, crushing the Centella asiatica; Step S3, placing the crushed Centella asiatica and supercritical carbon dioxide in an extraction kettle, performing static extraction and dynamic extraction to obtain a supercritical fluid; Step S4, sending the supercritical fluid into a separation kettle to restore the fluid to normal state, and separating the Centella asiatica essence and carbon dioxide; Step S5, sending the carbon dioxide separated in step S4 to a compressor for recycling and reuse.

[0018] In this embodiment, the process requires the application of corresponding extraction equipment, including an extraction kettle, a separation kettle, a compressor, a cooling device and a heating device. Before the process is carried out, it also includes the screening of raw materials, and preferably Centella asiatica with good appearance is used as the raw material.

[0019] In step S1, the drying treatment is to control the moisture content of Centella asiatica to below 10%, and the drying treatment is carried out by either low-temperature drying or vacuum drying.

[0020] Improve the efficiency of subsequent extraction and product quality. Controlling the moisture content of Centella asiatica below 10% helps ensure the stability and purity of the extract. Reducing the moisture content can reduce the risk of microbial contamination in the extract. The drying method can ensure that the effective ingredients in Centella asiatica are not destroyed while removing the moisture from the Centella asiatica.

[0021] Step S2 is a crushing process for crushing the Centella asiatica into a size of 80-100 meshes.

[0022] Crushing Centella asiatica into fine particles can significantly increase its contact area with supercritical carbon dioxide and ethanol, making it easier for the active ingredients to dissolve from plant cells, reaching dissolution equilibrium more quickly, shortening the extraction time and improving the extraction efficiency.

[0023] 10% ethanol was also added as an entrainer in the dynamic extraction of step S3.

[0024] Ethanol can form a co-solvent with supercritical CO2, enhancing the solubility of the supercritical fluid for the active ingredients in Centella asiatica, thereby improving the extraction efficiency. The addition of ethanol can change the polarity and solubility of the supercritical fluid, thereby adjusting the selective extraction of active ingredients with different polarities, making the proportion of ingredients in the extract more reasonable, helping to improve the fluidity of the supercritical fluid, reducing the mass transfer resistance during the extraction process, and further improving the extraction efficiency.

[0025] The extraction temperature of step S3 is 60° C. and the extraction pressure is 30 MPa.

[0026] It can maintain the stability of the effective ingredients in Centella asiatica and ensure that the supercritical fluid has sufficient solubility to extract these ingredients. Without causing damage to the structure of Centella asiatica powder, it effectively improves the solubility and carrying capacity of the supercritical fluid for the effective ingredients in Centella asiatica. The static extraction time was 1.5 h and the dynamic extraction time was 6 h.

[0027] The method also includes purifying the Centella asiatica extract extracted in step S4.

[0028] Removing impurities, residual solvents and other unnecessary components in the extract can make the active ingredients in the Centella asiatica extract more concentrated, improve the quality characteristics of the Centella asiatica extract such as color, smell and taste, remove substances that may be harmful to the human body, and ensure the safety of the product. In this embodiment, the purification process uses membrane separation to process the Centella asiatica extract, which is simple to operate, low in energy consumption, and can be carried out at room temperature, which is beneficial to protecting the activity of the active ingredients.

[0029] The extraction process of the Centella asiatica essence of the present invention uses ultrasonic cleaning to ensure that the cleaning is clean and has few impurities. After cleaning, low-temperature drying or vacuum drying is used to ensure that the effective ingredients in the Centella asiatica are not lost as much as possible. During extraction, supercritical carbon dioxide is used for extraction, so that the Centella asiatica will not be oxidized and is pure and natural without chemical pollution. The generated carbon dioxide can be recycled, reducing environmental pollution and having high extraction efficiency. The extracted Centella asiatica essence is then purified to further improve the clarity and purity of the Centella asiatica essence. Example 2

[0030] In this embodiment, the extraction process of Centella asiatica essence is basically the same as the production process of Example 1, the difference is that during extraction, the extraction is divided into multiple stages, and different temperatures, pressures and times are set for each stage to maximize the extraction according to the solubility and stability characteristics of different components in the raw materials.

[0031] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above in the form of preferred embodiments, it is not intended to limit the present invention. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for extracting Centella asiatica essence, characterized in that: The specific steps include: Step S1, cleaning and removing impurities from the Centella asiatica with an ultrasonic cleaning device, and drying the Centella asiatica after cleaning; Step S2, crushing the Centella asiatica; Step S3, placing the crushed Centella asiatica and supercritical carbon dioxide in an extraction kettle, performing static extraction and dynamic extraction to obtain a supercritical fluid; Step S4, sending the supercritical fluid into a separation kettle to restore the fluid to normal state, and separating the Centella asiatica essence and carbon dioxide; Step S5, sending the carbon dioxide separated in step S4 to a compressor for recycling and reuse.

2. The process for extracting the Centella asiatica essence according to claim 1, characterized in that: In the step S1, the moisture content of the Centella asiatica is controlled to be below 10%, and the drying method is either low-temperature drying or vacuum drying.

3. The process for extracting the Centella asiatica essence according to claim 1, characterized in that: The crushing process in step S2 is to crush the Centella asiatica into pieces with a size of 80-100 meshes.

4. The process for extracting the Centella asiatica essence according to claim 1, characterized in that: 10% ethanol is also added as an entrainer in the dynamic extraction of step S3.

5. The process for extracting the Centella asiatica essence according to claim 1, characterized in that: The extraction temperature of step S3 is 60° C. and the extraction pressure is 30 MPa.

6. The process for extracting the essence of Centella asiatica according to claim 1, characterized in that: The static extraction time is 1.5 hours, and the dynamic extraction time is 6 hours.

7. The process for extracting the essence of Centella asiatica according to claim 1, characterized in that: The method also includes purifying the Centella asiatica extract extracted in step S4.

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