A new method for green extraction and efficient enrichment of cannabidiol

Abstract

The present invention belongs to the field of extraction and enrichment of fat-soluble active ingredients, and particularly relates to a new method for the green extraction and efficient enrichment of cannabidiol. In the present invention, fresh undried industrial hemp bracts are decarboxylated and converted, so that cannabidiolic acid in the plant is rapidly converted into cannabidiol, and then an aqueous solution of dodecyl betaine is used for the green extraction of the decarboxylated bracts. According to the interfacial charge characteristics of the supramolecule formed by dodecyldimethylbetaine and cannabidiol in the aqueous solution of dodecyl betaine, the surface potential characteristics of tannic acid are utilized to directionally enrich cannabidiol. The new method for green extraction and efficient enrichment provided by the present invention has a high extraction rate of cannabidiol and complete enrichment of cannabidiol. No organic solvent is used in the whole process, the cost is low, and it is safe and reliable. The method not only improves the conversion and utilization rate of medicinal components in industrial hemp, but also has great significance for the industrial safe production of cannabidiol.

Description

Technical Field

[0001] The present invention belongs to the field of extraction and enrichment of fat-soluble active ingredients, and particularly relates to a new method for green extraction and efficient enrichment of cannabidiol. Background Art

[0002] With the continuous development of disciplines such as chemistry and life medicine, it has now been found that industrial hemp has extremely strong industrial value in the fields of medicine and clinical applications. Among the many cannabinoid compounds in industrial hemp, cannabidiol is the most studied non-psychoactive medicinal substance. In 2018, the US Food and Drug Administration (FDA) approved the first cannabidiol drug, Epidiolex, for the treatment of three rare developmental and epileptic encephalopathies (tuberous sclerosis complex, Dravet syndrome, and Lennox-Gastaut syndrome).

[0003] Currently, looking at the existing research results on the extraction and enrichment of cannabidiol, new extraction technologies and methods are increasingly becoming the mainstream of cannabidiol extraction. Since cannabidiol is insoluble in water, organic solvents are usually used for its extraction. For example, in the literature "Analysis of Cannabidiol Content in Industrial Hemp Leaves" (Gao Baochang et al. Analysis of Cannabidiol Content in Industrial Hemp Leaves [J]. Heilongjiang Science, 2018, 9(01): 61-63), by using ultrasonic wave as the extraction technical means, the influence of the type of extraction solvent on the extraction efficiency of cannabidiol in industrial hemp was investigated, and it was determined that anhydrous methanol was the extraction solvent with the highest extraction efficiency. Although the method can extract efficiently, the selection of the solvent is a traditional organic solvent, which is flammable, explosive, and highly harmful to the human body, lacking application safety.

[0004] Chinese Patent CN110156569A extracts and enriches cannabidiol in industrial hemp through supercritical carbon dioxide technology. Although the extraction process does not involve the use of organic solvents, the equipment requires a certain amount of time for heating, pressurization, and depressurization, and the extraction time is too long, resulting in high energy consumption, low extraction efficiency, and relatively cumbersome technical operations. Chinese Patent CN109646992A does not involve the addition of organic solvents during the extraction process, but with the addition of sodium hydroxide and sulfuric acid, the operation risk increases. Summary of the Invention

[0005] The present invention provides a method for green extraction and efficient enrichment of cannabidiol in industrial hemp. The method is safe, simple to operate, low in operating cost, fully extracts cannabidiol, and has good enrichment effect. It not only improves the conversion and utilization rate of medicinal components in industrial hemp, but also has great significance for the industrial safe production of cannabidiol.

[0006] To achieve the above objectives, the present invention provides the following technical solutions including decarboxylation conversion, green extraction, and efficient enrichment:

[0007] Decarboxylation conversion: Rapidly decarboxylate and convert fresh bracts of industrial hemp to obtain raw materials for high-content cannabidiol extraction, and then crush and screen them for standby;

[0008] Green extraction: Mix the crushed bract powder with a dodecyldimethylbetaine solution for extraction to obtain a cannabidiol extract;

[0009] Directional enrichment: Stir and mix the cannabidiol extract and tannic acid solution for directional enrichment of cannabidiol to obtain a cannabidiol-enriched product.

[0010] Preferably, the rapid decarboxylation conversion method of the fresh bracts of industrial hemp is one of hot air heating, vacuum heating or microwave heating.

[0011] Preferably, the temperature for rapid decarboxylation conversion of the fresh bracts of industrial hemp is 60-150°C, and the time is 15-45 min; the particle size of the crushed industrial hemp bract raw material is 20-100 mesh.

[0012] Preferably, the mass percentage content of dodecyldimethylbetaine in the dodecyldimethylbetaine solution is 2-15 wt%; the mass ratio of the bract powder to the volume of the dodecyldimethylbetaine solution is 1 g:6-25 mL.

[0013] Preferably, the extraction includes one or more of heating reflux extraction, microwave extraction, ultrasonic extraction or pressurized extraction.

[0014] Preferably, the extraction is carried out in an extraction device, and the extraction device is one or more of a heating reflux extraction device, a microwave extraction device, an ultrasonic extraction device or a pressurized extraction device.

[0015] Preferably, the mass percentage content of tannic acid in the tannic acid solution is 2-15 wt%; the addition amount of the tannic acid solution is 20-80% of the volume of the cannabidiol extract; the temperature for directional enrichment of cannabidiol is 30-45°C, and the time is 16-32 min.

[0016] Preferably, the green extraction and directional enrichment product is also obtained by solid-liquid separation; the solid-liquid separation is carried out by centrifugation, the centrifugation speed is 4000-8000 rpm, and the centrifugation time is 6-10 min. A new method for green extraction and high-efficiency enrichment of cannabidiol of the present invention includes the following steps: decarboxylation conversion: quickly decarboxylate and convert fresh bracts of industrial hemp to obtain a high-content cannabidiol extraction raw material, and then pulverize and sieve for standby; green extraction: mix the pulverized bract powder and dodecyl dimethyl betaine solution for extraction to obtain a cannabidiol extract; directional enrichment: stir and mix the cannabidiol extract and tannic acid solution for directional enrichment of cannabidiol to obtain a cannabidiol enrichment product. The present invention first starts from the chemical conversion of secondary metabolites of industrial hemp and the factors affecting the speed of chemical reactions. By using the water in fresh industrial hemp bracts without drying treatment, during the heat-induced decarboxylation conversion process, the movement of cannabidiolic acid molecules can be accelerated, which is more conducive to the conversion to cannabidiol. Before extracting industrial hemp, a higher content of cannabidiol can be obtained to prevent the waste of metabolite resources in the plant body; then, dodecyl dimethyl betaine is used to extract cannabidiol from the decarboxylated bract powder. During the extraction process, a hydrogen bond force is generated between dodecyl dimethyl betaine and cannabidiol, which can wrap cannabidiol in the hydrophobic core to form a supramolecular system; finally, according to the supramolecular interfacial charge characteristics formed by dodecyl dimethyl betaine and cannabidiol, the electrostatic adsorption between tannic acid and dodecyl dimethyl betaine is used to directionally and efficiently enrich cannabidiol in the extract. The present invention uses an aqueous solution of dodecyl dimethyl betaine to replace the organic solvents used in traditional industrial hemp extraction. The solvent is green and safe, and has no disadvantages such as flammability, explosiveness, and high harm to the human body compared with traditional extraction solvents; natural flocculating components are selected to efficiently enrich the extracted cannabidiol, and no harmful substances to the environment and human body are introduced. In summary, the extraction and enrichment method provided by the present invention is simple in operation, high in extraction efficiency, low in energy consumption, does not use any organic solvents during the extraction process, the whole process is safe and reliable, has high economic benefits and environmental benefits, and is suitable for industrial production. The data from the examples show that the extraction method of the present invention has a cannabidiol extraction rate of up to 98.71% for industrial hemp, and the cannabidiol in the extract can be completely enriched. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of the pressurized extraction equipment provided by the present invention;

[0018] Figure 2 It is a comparison diagram of scanning electron microscopes of industrial hemp bracts before (a) and after (b) extraction obtained in Example 1 of the present invention;

[0019] Figure 3 It is a comparison diagram of transmission electron microscopes before (a) and after (b) the extract obtained in Example 2;

[0020] Figure 4 The high performance liquid chromatography (HPLC) chart of the cannabidiol extract obtained in Example 5;

[0021] Figure 5 The comparison chart before (a) and after (b) the directional enrichment centrifugation of cannabidiol;

[0022] Figure 6 The high performance liquid chromatography (HPLC) chart of the supernatant of the directional enrichment of cannabidiol obtained in Example 5.

[0023] Explanation of the reference numerals in the figure: 1 - plunger, 2 - high pressure cylinder, 3 - water medium, 4 - extraction material, 5 - low pressure cylinder, 6 - frame. Detailed implementation mode

[0024] The present invention provides a new method for green extraction and high-efficiency enrichment of cannabidiol from industrial hemp, comprising the following steps:

[0025] Decarboxylation conversion: Rapidly decarboxylate and convert fresh bracts of industrial hemp to obtain a raw material for extracting cannabidiol with a high content, and then crush and sieve it for standby;

[0026] Green extraction: Mix the crushed bract powder and dodecyl dimethyl betaine solution for extraction to obtain a cannabidiol extract;

[0027] Directional enrichment: Mix the cannabidiol extract and tannic acid solution for directional enrichment of cannabidiol to obtain a cannabidiol enrichment product.

[0028] The present invention rapidly decarboxylates and converts fresh bracts of industrial hemp to obtain a raw material for extracting cannabidiol with a high content, and then crushes and sieves it for standby. In the present invention, the rapid decarboxylation conversion of fresh bracts of industrial hemp comprises the following steps: Heat the fresh bracts of industrial hemp to obtain the above-mentioned raw material for extracting cannabidiol with a high content. The preferred heating method for decarboxylation conversion is one of hot air heating, vacuum heating or microwave heating. The decarboxylation conversion temperature is preferably 60 - 150°C, more preferably 60°C, 80°C, 100°C, 120°C or 150°C; the decarboxylation conversion time is preferably 15 - 45 min. The present invention has no special requirements for the specific implementation mode of crushing. The sieving is carried out using a sieve, and the diameter of the sieve is preferably 20 - 100 mesh, more preferably 40 - 80 mesh. The particle size of the obtained industrial hemp bract powder is preferably 20 - 100 mesh, more preferably 40 - 80 mesh.

[0029] After obtaining the industrial hemp bract powder, the present invention mixes the industrial hemp bract powder with a dodecyl dimethyl betaine solution for extraction to obtain a cannabidiol extract. In the present invention, the mass percentage content of the dodecyl betaine solution is preferably 2-15 wt%, more preferably 4 wt%, 6 wt%, 8 wt%, or 12.5 wt%. The mass ratio of the industrial hemp bract powder to the volume of the dodecyl dimethyl betaine is preferably 1 g:5-25 mL, more preferably 1 g:8 mL, 1 g:10 mL, 1 g:12.5 mL, or 1 g:15 mL. In the present invention, the extraction includes one or more of heating reflux extraction, microwave extraction, ultrasonic extraction, and pressurized extraction, more preferably heating reflux extraction, ultrasonic extraction, or pressurized extraction. When the extraction is preferably heating reflux extraction, the number of times of heating reflux extraction is preferably 1-3 times, and the time of each heating reflux extraction is preferably 45-60 min. When the extraction is preferably ultrasonic extraction, the number of times of ultrasonic extraction is preferably 1-3 times, and the time of each ultrasonic extraction is preferably 30-45 min. When the extraction is preferably pressurized extraction, the pressure of the pressurized extraction is preferably 20-200 MPa, specifically preferably 20 MPa, 100 MPa, or 200 MPa; the number of times of pressurized extraction is preferably 1-3 times, and the time of each pressurized extraction is preferably 2-6 min, specifically preferably 2 min, 4 min, or 6 min.

[0030] The extraction is carried out in an extraction device, and the extraction device is preferably one or more of a heating reflux extraction device, a microwave extraction device, an ultrasonic extraction device, or a pressurized extraction device, more preferably a heating reflux extraction device, an ultrasonic extraction device, or a pressurized extraction device.

[0031] In the present invention, the extraction directly obtains an extraction slurry, and the present invention further includes solid-liquid separation of the extraction slurry, and the obtained liquid phase is the cannabidiol extract. The solid-liquid separation is preferably centrifugal separation, and the rotation speed of the centrifugal separation is preferably 4000-8000 rpm, and the time is preferably 6-10 min.

[0032] After obtaining the cannabidiol extract, the present invention mixes the cannabidiol extract with a tannic acid solution for cannabidiol enrichment to obtain a cannabidiol enriched product. In the present invention, the mass percentage content of tannic acid in the tannic acid solution is preferably 5-15 wt%, more preferably 4 wt%, 6 wt%, 8 wt%, or 12.5 wt%. The addition amount of the tannic acid solution is preferably 20-80% of the volume of the cannabidiol extract, more preferably 20%, 40%, 60%, or 80%. The temperature for cannabidiol directional enrichment is preferably 30-45 °C, and the directional enrichment time is preferably 16-32 min.

[0033] In the present invention, the cannabidiol is directly enriched to obtain an enriched slurry. The present invention further includes solid-liquid separation of the enriched slurry, and the obtained solid phase is the cannabidiol-enriched precipitate. The solid-liquid separation is preferably centrifugal separation, and the rotation speed of the centrifugal separation is preferably 4000-8000 rpm, and the time is preferably 6-10 min.

[0034] The present invention provides a new method for green extraction and high-efficiency enrichment of cannabidiol. By subjecting fresh undried industrial hemp bracts to high-temperature rapid decarboxylation, the cannabidiolic acid in the plant is rapidly decarboxylated and converted into cannabidiol, and then an aqueous solution of dodecyl betaine is used for green extraction of the decarboxylated bracts. According to the interfacial charge characteristics of the supramolecule formed by dodecyldimethylbetaine and cannabidiol in the aqueous solution of dodecyl betaine, the tannic acid surface potential characteristics are used for the directional enrichment of cannabidiol. The new method for green extraction and high-efficiency enrichment provided by the present invention has a high extraction rate of cannabidiol and complete enrichment of cannabidiol. No organic solvent is used in the whole process, the cost is low, and it is safe and reliable. The invention not only improves the conversion and utilization rate of medicinal components in industrial hemp, but also has great significance for the industrial safe production of cannabidiol.

[0035] The following further illustrates a new method for green extraction and high-efficiency enrichment of cannabidiol according to the present invention with reference to examples. The described examples are partial examples of the present invention and cannot be used to limit the scope of the present invention. Modifications and substitutions of the technical solutions of the present invention without departing from the spirit of the present invention are within the protection scope of the present invention. The experimental methods described in the following examples are all conventional experimental methods unless otherwise specified, and the materials and reagents can be obtained from commercial sources unless otherwise specified.

[0036] Example 1:

[0037] The fresh bracts of industrial hemp were microwave-heated and decarboxylated at 60 °C for 30 min to obtain industrial hemp bract raw materials with a high content of cannabidiol, and then they were pulverized and passed through a 40-mesh sieve for standby. By high-performance liquid chromatography analysis, according to the cannabidiol content in the industrial hemp bracts before and after decarboxylation conversion, the decarboxylation conversion rate of cannabidiolic acid was calculated to be 85.71%.

[0038] 50 g of the decarboxylated industrial hemp bract powder was taken, 8 times the amount of a 4 wt% aqueous solution of dodecyldimethylbetaine was added, and it was placed in a heat reflux extraction device and heated and refluxed for 45 min, and the extraction was carried out 3 times. After each extraction, it was centrifuged at 4000 rpm for 7 min to obtain a cannabidiol extract. By high-performance liquid chromatography determination and analysis, according to the cannabidiol content in the industrial hemp bracts and the cannabidiol content in the extract, the cannabidiol extraction rate was calculated to be 86.74%.

[0039] Under the condition of an enrichment temperature of 30 °C, a 4 wt% tannic acid solution was added at 20% of the volume of the cannabidiol extract, and stirred for 20 min for the directional enrichment of cannabidiol. After the enrichment was completed, centrifugation was carried out at a speed of 5000 rpm for 6 min to obtain a cannabidiol-enriched product. By analysis using the high-performance liquid method, according to the content of cannabidiol in the extract before and after enrichment, the cannabidiol enrichment rate was calculated to be 73.42%.

[0040] Example 2:

[0041] Fresh industrial hemp bracts were microwave-heated for decarboxylation conversion at 80 °C for 20 min to obtain industrial hemp bract raw materials with a high content of cannabidiol, and then they were crushed and passed through a 100-mesh sieve for standby. By analysis using the high-performance liquid method, according to the content of cannabidiol in the industrial hemp bracts before and after decarboxylation conversion, the decarboxylation conversion rate of cannabidiolic acid was calculated to be 90.71%.

[0042] Take 50 g of the decarboxylated industrial hemp bract powder, add 10 times the amount of a 4 wt% aqueous solution of dodecyldimethylbetaine, seal it in a polyethylene bag, place it in the high-pressure cylinder of a pressurized extraction device, set the extraction pressure to 20 MPa, and keep the pressure for 2 min, repeating 3 times. After each extraction was completed, centrifugation was carried out at a speed of 5000 rpm for 7 min to obtain a cannabidiol extract. By determination and analysis using high-performance liquid chromatography, according to the content of cannabidiol in the industrial hemp bracts and the content of cannabidiol in the extract, the cannabidiol extraction rate was calculated to be 92.17%.

[0043] Under the condition of an enrichment temperature of 35 °C, a 6 wt% tannic acid solution was added at 40% of the volume of the cannabidiol extract, and stirred for 28 min for the directional enrichment of cannabidiol. After the enrichment was completed, centrifugation was carried out at a speed of 6000 rpm for 7 min to obtain a cannabidiol-enriched product. By analysis using the high-performance liquid method, according to the content of cannabidiol in the extract before and after enrichment, the cannabidiol enrichment rate was calculated to be 89.72%.

[0044] Example 3:

[0045] Fresh industrial hemp bracts were vacuum-heated for decarboxylation conversion at 80 °C for 15 min to obtain industrial hemp bract raw materials with a high content of cannabidiol, and then they were crushed and passed through a 40-mesh sieve for standby. By analysis using the high-performance liquid method, according to the content of cannabidiol in the industrial hemp bracts before and after decarboxylation conversion, the decarboxylation conversion rate of cannabidiolic acid was calculated to be 87.47%.

[0046] Take 50 g of decarboxylated industrial hemp bract powder, add 8 times the amount of a 6 wt% aqueous solution of dodecyl dimethyl betaine, seal it in a polyethylene bag, place it in the high-pressure cylinder of a pressurized extraction device, set the extraction pressure to 100 MPa, keep the pressure for 4 min, and repeat 3 times. After each extraction, centrifuge at 6000 rpm for 7 min to obtain a cannabidiol extract. Through high-performance liquid chromatography determination and analysis, according to the cannabidiol content in industrial hemp bracts and the cannabidiol content in the extract, calculate the cannabidiol extraction rate to be 95.68%.

[0047] Under the condition of an enrichment temperature of 35 °C, add an 8 wt% tannic acid solution according to 40% of the volume of the cannabidiol extract, stir for 30 min, and perform the directional enrichment of cannabidiol. After the enrichment is completed, centrifuge at 7000 rpm for 6 min to obtain a cannabidiol enrichment product. Through high-performance liquid chromatography analysis, according to the cannabidiol content in the extract before and after enrichment, calculate the cannabidiol enrichment rate to be 93.75%.

[0048] Example 4:

[0049] Heat the fresh industrial hemp bracts at 120 °C for 15 min by hot air for decarboxylation conversion to obtain high-content cannabidiol industrial hemp bract raw materials, then crush them and pass through a 60-mesh sieve for standby. Through high-performance liquid chromatography analysis, according to the cannabidiol content in industrial hemp bracts before and after decarboxylation conversion, calculate the decarboxylation conversion rate of cannabidiolic acid to be 94.26%.

[0050] Take 50 g of decarboxylated industrial hemp bract powder, add 12.5 times the amount of a 4 wt% aqueous solution of dodecyl dimethyl betaine, place it in an ultrasonic extraction device, and perform ultrasonic extraction for 30 min, extracting 3 times. After each extraction, centrifuge at 5000 rpm for 7 min to obtain a cannabidiol extract. Through high-performance liquid chromatography determination and analysis, according to the cannabidiol content in industrial hemp bracts and the cannabidiol content in the extract, calculate the cannabidiol extraction rate to be 91.74%.

[0051] Under the condition of an enrichment temperature of 40 °C, add a 4 wt% tannic acid solution according to 40% of the volume of the cannabidiol extract, stir for 28 min, and perform the directional enrichment of cannabidiol. After the enrichment is completed, centrifuge at 7000 rpm for 6 min to obtain a cannabidiol enrichment product. Through high-performance liquid chromatography analysis, according to the cannabidiol content in the extract before and after enrichment, calculate the cannabidiol enrichment rate to be 85.72%.

[0052] Example 5:

[0053] The fresh bracts of industrial hemp are heated with hot air for decarboxylation conversion at 150 °C for 10 min to obtain the industrial hemp bract raw material with high content of cannabidiol, and then it is pulverized and sieved through 80-mesh sieve for standby. Through high-performance liquid chromatography analysis, according to the content of cannabidiol in the industrial hemp bracts before and after decarboxylation conversion, the decarboxylation conversion rate of cannabidiolic acid is calculated to be 97.47%.

[0054] Take 50 g of the decarboxylated industrial hemp bract powder, add 10 times the amount of 12.5 wt% dodecyldimethylbetaine aqueous solution, place it in an ultrasonic extraction device, and perform ultrasonic extraction for 40 min, extracting 3 times. After each extraction, centrifuge at 8000 rpm for 6 min to obtain the cannabidiol extract. Through high-performance liquid chromatography determination and analysis, according to the content of cannabidiol in the industrial hemp bracts and the content of cannabidiol in the extract, the extraction rate of cannabidiol is calculated to be 98.71%.

[0055] Under the condition of an enrichment temperature of 45 °C, add an 8 wt% tannic acid solution according to 80% of the volume of the cannabidiol extract, stir for 32 min, and perform the directional enrichment of cannabidiol. After the enrichment is completed, centrifuge at 7000 rpm for 10 min to obtain the cannabidiol enrichment product. Through high-performance liquid chromatography analysis, according to the content of cannabidiol in the extract before and after enrichment, the cannabidiol in the extract is completely enriched.

[0056] Example 6:

[0057] The fresh bracts of industrial hemp are heated under vacuum for decarboxylation conversion at 100 °C for 45 min to obtain the industrial hemp bract raw material with high content of cannabidiol, and then it is pulverized and sieved through 60-mesh sieve for standby. Through high-performance liquid chromatography analysis, according to the content of cannabidiol in the industrial hemp bracts before and after decarboxylation conversion, the decarboxylation conversion rate of cannabidiolic acid is calculated to be 95.66%.

[0058] Take 50 g of the decarboxylated industrial hemp bract powder, add 15 times the amount of 4 wt% dodecyldimethylbetaine aqueous solution, place it in a heat reflux extraction device, heat and reflux for 60 min, extracting 3 times. After each extraction, centrifuge at 6000 rpm for 8 min to obtain the cannabidiol extract. Through high-performance liquid chromatography determination and analysis, according to the content of cannabidiol in the industrial hemp bracts and the content of cannabidiol in the extract, the extraction rate of cannabidiol is calculated to be 93.83%.

[0059] Under the condition of an enrichment temperature of 35 °C, add a 12.5 wt% tannic acid solution according to 40% of the volume of the cannabidiol extract, stir for 32 min, and perform the directional enrichment of cannabidiol. After the enrichment is completed, centrifuge at 7000 rpm for 10 min to obtain the cannabidiol enrichment product. Through high-performance liquid chromatography analysis, according to the content of cannabidiol in the extract before and after enrichment, the enrichment rate of cannabidiol is calculated to be 96.72%.

[0060] Example 7:

[0061] The fresh bracts of industrial hemp were heated with hot air for decarboxylation conversion at 100 °C for 15 min to obtain the bract raw materials of industrial hemp with high content of cannabidiol, and then they were crushed and passed through a 40-mesh sieve for standby. By analyzing through the high-performance liquid method, according to the content of cannabidiol in the bracts of industrial hemp before and after decarboxylation conversion, the decarboxylation conversion rate of cannabidiolic acid was calculated to be 89.61%.

[0062] Take 50 g of the decarboxylated industrial hemp bract powder, add 15 times the amount of an 8 wt% aqueous solution of dodecyldimethylbetaine, seal it in a polyethylene bag, place it in the high-pressure cylinder of a pressurized extraction device, set the extraction pressure to 200 MPa, keep the pressure for 6 min, and repeat 3 times. After each extraction, centrifuge at 7500 rpm for 8 min to obtain the cannabidiol extract. By measuring and analyzing through high-performance liquid chromatography, according to the content of cannabidiol in the bracts of industrial hemp and the content of cannabidiol in the extract, the extraction rate of cannabidiol was calculated to be 98.73%.

[0063] Under the condition of an enrichment temperature of 42 °C, add an 8 wt% tannic acid solution according to 60% of the volume of the cannabidiol extract, stir for 40 min for the directional enrichment of cannabidiol. After the enrichment, centrifuge at 8000 rpm for 8 min to obtain the cannabidiol enrichment product. By analyzing through the high-performance liquid method, according to the content of cannabidiol in the extract before and after enrichment, the enrichment rate of cannabidiol was calculated to be 97.34%.

[0064] Although the above embodiments have described the present invention in detail, they are only partial embodiments of the present invention, not all embodiments. For those of ordinary skill in the art, other embodiments can be obtained according to these embodiments without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for extracting and enriching cannabidiol, characterized in that, It includes the following steps: Decarboxylation conversion: The fresh bracts of industrial hemp are rapidly decarboxylated and converted by one or more of hot air heating, vacuum heating or microwave heating to obtain a high-content cannabidiol extraction raw material, and then pulverized and sieved for standby; Extraction: The pulverized bract powder is mixed with a dodecyldimethylbetaine solution, and extracted by one or more of heating under reflux extraction, microwave extraction, ultrasonic extraction or pressurized extraction to obtain a cannabidiol extract; Directional enrichment: The cannabidiol extract and tannic acid solution are stirred and mixed for directional enrichment of cannabidiol to obtain a cannabidiol enrichment product.

2. The method for extracting and enriching cannabidiol according to claim 1, characterized in that, The rapid decarboxylation conversion temperature of the fresh bracts of industrial hemp is 60~150°C, and the time is 15~45 min; the pulverization particle size of the industrial hemp bract raw material is 20~100 mesh.

3. The method for extracting and enriching cannabidiol according to claim 1, wherein, The mass percentage content of dodecyldimethylbetaine in the dodecyldimethylbetaine solution is 2~15 wt%; the mass ratio of the bract powder to the volume of the dodecyldimethylbetaine solution is 1 g:6~25 mL.

4. A method for extracting and enriching cannabidiol according to claim 1, characterized in that, The extraction is carried out in an extraction device, and the extraction device is one or more of a heating under reflux extraction device, a microwave extraction device, an ultrasonic extraction device or a pressurized extraction device.

5. A method for extracting and enriching cannabidiol according to claim 1, characterized in that, The mass percentage content of tannic acid in the tannic acid solution is 5~15 wt%; the addition amount of the tannic acid solution is 20~80% of the volume of the cannabidiol extract; the cannabidiol directional enrichment temperature is 30~45°C, and the time is 16~32 min.

6. A method for extracting and enriching cannabidiol according to claim 1, characterized in that, The extraction and directional enrichment also include a solid-liquid separation operation; the solid-liquid separation is carried out by centrifugation, the centrifugation speed is 4000~8000 rpm, and the centrifugation time is 6~10 min.

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