Preparation method of high-purity cinnamomum longepaniculatum essential oil
By combining distillation extraction, vacuum distillation, and low eutectic solvent extraction with freeze crystallization, the problems of complex composition and numerous impurities in camphor oil were solved, and the efficient preparation of high-purity camphor essential oil was achieved.
Patent Information
- Application Number
- CN202511541135.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-27
- Publication Date
- 2025-12-19
AI Technical Summary
In existing camphor oil extraction processes, the composition of camphor oil is complex, the yield is not ideal, and there are many impurities, which leads to complicated subsequent processing.
The essential oil of camphor tree is separated and purified by steps including distillation extraction, vacuum distillation, low eutectic solvent extraction and freeze crystallization, including crushing camphor tree leaves, vacuum distillation, mixing with low eutectic solvent, adding mixed salt solution and cooling crystallization.
This method improves the yield of camphor oil, reduces the content of impurities, and especially reduces the crystallization difficulty of effective components such as 1,8-cineole, resulting in high-purity camphor essential oil.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of plant essential oil preparation, and particularly relates to a preparation method of high-purity oil camphor essential oil. BACKGROUND
[0002] Oil camphor is a tree species of Lauraceae in China. In the early stage, oil camphor was often obtained by distillation. Distillation is a method of co-distilling plant materials containing volatile components with water, so that the volatile components are distilled out with water vapor, and the volatile components of oil camphor are separated by condensation. This method belongs to crude oil extraction, and the efficiency is generally low. At present, corresponding improvements have been made on this basis. For example, the distillation method is improved by using leaching. The aromatic components in the plant raw material are leached out by using volatile organic solvents, so that they are dissolved in the organic solvents, and then the solvents are evaporated to obtain leaching products. For another example, a porous solid adsorbent is used to adsorb one or several components in water samples on the surface, and then the predicted components are desorbed by using a suitable solvent, heating or blowing gas, so as to achieve the purpose of separation and enrichment. For another example, the oil camphor leaves are extracted. The temperature inside the material is suddenly increased by heating the material, and the temperature can be maintained until the internal pressure exceeds the expansion capacity of the cell wall, so that the cells are broken, and the perfume substances in the cells flow out, transfer and transfer to the surrounding extraction medium. Extraction is often used in microwave-assisted extraction.
[0003] It is worth noting that the current extraction method mainly relies on the natural separation of perfume substances from the material. Due to the limited separation degree of the material at present, the oil yield in the later extraction process is not ideal, and the extracted oil camphor oil composition is relatively complex, which needs to be treated by a relatively complex post-treatment to obtain the desired components. Therefore, how to improve the oil extraction rate of oil camphor and reduce impurities to protect the efficient use of oil camphor resources is worth further thinking and research. SUMMARY
[0004] In view of the above prior art, the application provides a preparation method of high-purity oil camphor essential oil to solve the technical problem that the oil camphor oil prepared by the existing extraction process has a complex composition.
[0005] In order to achieve the above purpose, the technical scheme adopted by the application is to provide a preparation method of high-purity oil camphor essential oil, comprising the following steps: S1: distillation extraction of fresh oil camphor leaves to obtain oil camphor crude product; S2: vacuum rectification treatment of the oil camphor crude product to obtain oil camphor essential oil; S3: mixing the oil camphor essential oil with a low eutectic solvent, stirring and then separating and collecting the lower solvent phase; then mixing the solvent phase with water, stirring and then separating and collecting the upper oil phase; the low eutectic solvent is a mixture of tropine alcohol and polyhydric alcohol; S4: the collected oil phase is mixed with ethanol at a volume ratio of 1:1-3, a mixed salt solution is added to the mixture, and then the mixture is cooled to-5-0℃, and stirred for 30-60 min, and then incubated and left standing for 16-24 h, followed by centrifugation, separation of the crystals from the mother liquor, and washing the crystals with pre-cooled ethanol to obtain the oil of camphor tree crystals; the solutes of the mixed salt solution are sodium chloride, magnesium sulfate and sodium acetate, and the solvent is water; S5: the oil of camphor tree crystals is heated to melt, then cooled to room temperature, and then centrifuged to obtain high-purity oil of camphor tree.
[0006] Based on the above technical solutions, the application can be further improved as follows.
[0007] Further, the distillation extraction in S1 includes the following steps: The fresh leaves of the oil of camphor tree are crushed into a slurry and loaded into a distillation device, and then steam at a temperature of 95-100℃ is introduced into the distillation device; the steam flowing out of the distillation device is introduced into a condensation device for condensation to obtain the crude oil of camphor tree; the distillation time is 3-5 h.
[0008] Further, the vacuum rectification in S2 includes the following steps: The crude oil of camphor tree is evaporated and refluxed at a reflux ratio of 6:1 under the condition of 4-5 kPa for 2-3 h to obtain the oil of camphor tree.
[0009] Further, the eutectic solvent is mixed by mixing tropine alcohol and polyhydric alcohol at a molar ratio of 1:5-10; the polyhydric alcohol is ethylene glycol or 1,3-propanediol.
[0010] Further, the oil of camphor tree and the eutectic solvent are mixed at a volume ratio of 1:1-3 in S3.
[0011] Further, the volume ratio of the solvent phase to water in S3 is 1:1-2.
[0012] Further, after the mixed salt solution is added in S4, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 1-3%, 1-3% and 2-5% of the mass of the oil phase, respectively.
[0013] Further, the cooling rate in S4 is 3-5℃ / min; the stirring speed is 30-45 rpm.
[0014] Further, the incubation and stirring time in S4 is 45 min; the incubation and standing time is 20 h.
[0015] Further, the temperature of the pre-cooled ethanol in S4 is-5℃.
[0016] The application has the following beneficial effects: 1. In the process of distilling and extracting camphor tree leaves, the present invention first crushes the camphor tree leaves into a pulp to destroy the cell structure of the leaves, making it easier for the oil to be released from the cells to the outside of the cells, reducing the resistance to oil diffusion during steam distillation, thereby increasing the yield of camphor oil.
[0017] 2. In this invention, after obtaining crude camphor oil by distillation, the crude camphor oil is subjected to vacuum distillation, which can remove components such as α-pinene and β-phellandrene from the crude camphor oil. This not only reduces the difficulty of crystallizing effective components such as 1,8-cineole, but also reduces the impurity content of the final camphor essential oil, thus ensuring the quality of the camphor essential oil.
[0018] 3. In this invention, after vacuum distillation of crude camphor oil, further extraction and back-extraction are carried out. The reagent used for extraction is a low eutectic solvent obtained by mixing tropine alcohol and polyol, which can specifically extract 1,8-cineole from camphor essential oil, while reducing the co-extraction of impurities such as camphor, linalool, and terpineol, thereby reducing the impurity content in camphor oil.
[0019] 4. Before the freeze-crystallization treatment of camphor oil, this invention first mixes the camphor oil with ethanol to reduce its viscosity, thereby promoting crystallization. Furthermore, a mixed salt solution, comprising sodium chloride, magnesium sulfate, and sodium acetate, is added to the mixture. Sodium chloride and magnesium sulfate reduce the solubility of 1,8-cineole in the oil through salting-out, promoting its precipitation. Sodium acetate adjusts the pH of the system, allowing 1,8-cineole to precipitate more effectively. The combined effect of all components in the mixed salt significantly promotes the crystallization of 1,8-cineole in camphor oil, facilitating the separation of 1,8-cineole from the remaining components, thus obtaining camphor oil with a high 1,8-cineole content. Detailed Implementation
[0020] The specific embodiments of the present invention will be described in detail below with reference to examples.
[0021] Example 1 A method for preparing high-purity camphor oil includes the following steps: S1: Crush fresh camphor tree leaves into a pulp and put it into a distillation apparatus. Then, steam at a temperature of 100°C is introduced into the distillation apparatus. The steam flowing out of the distillation apparatus is then condensed in a condenser to obtain crude camphor oil. The distillation time is 4 hours. S2: Evaporate the crude camphor oil at a reflux ratio of 6:1 for 2.5 h under 4.5 kPa conditions to obtain camphor essential oil; S3: The camphor oil and the deep eutectic solvent are mixed at a volume ratio of 1:2, and after stirring at room temperature, the lower solvent phase is collected by separation. Then the solvent phase is mixed with water at a volume ratio of 1:2, and after stirring at room temperature, the upper oil phase is collected by separation. The deep eutectic solvent used is a mixture of tropine alcohol and ethylene glycol at a molar ratio of 1:8; S4: The collected oil phase is mixed with ethanol at a volume ratio of 1:2, and then a mixed salt solution is added to the mixture. The temperature is then lowered to -3°C at a rate of 4°C / min, and the mixture is stirred at a rate of 40 rpm for 45 min. After that, the mixture is left to stand for 20 h, and then centrifuged at a speed of 3000 rpm for 30 min to separate the crystals from the mother liquor. The crystals are then washed with pre-cooled ethanol at -5°C for 3 times to obtain the camphor oil crystals. The mixed salt solution used has sodium chloride (33 g / mL), magnesium sulfate and sodium acetate as solutes, and water as solvent. After adding the mixed salt solution, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 2%, 1% and 4% of the mass of the oil phase, respectively. S5: The camphor oil crystals are heated to melt, then cooled to room temperature, and then centrifuged to obtain the high-purity camphor oil.
[0022] Example 2 A method for preparing high-purity camphor oil, comprising the following steps: S1: Fresh camphor tree leaves are crushed into a slurry and placed in a distillation device, and then steam at a temperature of 95°C is introduced into the distillation device. The steam flowing out of the distillation device is condensed in a condensation device to obtain crude camphor oil. The distillation time is 5 h. S2: The crude camphor oil is evaporated and refluxed at 4 kPa for 3 h at a reflux ratio of 6:1 to obtain camphor oil. S3: The camphor oil and the deep eutectic solvent are mixed at a volume ratio of 1:1, and after stirring at room temperature, the lower solvent phase is collected by separation. Then the solvent phase is mixed with water at a volume ratio of 1:1, and after stirring at room temperature, the upper oil phase is collected by separation. The deep eutectic solvent used is a mixture of tropine alcohol and 1,3-propanediol at a molar ratio of 1:5. S4: The collected oil phase is mixed with ethanol at a volume ratio of 1:1, and then a mixed salt solution is added to the mixture. The temperature is then lowered to 0°C at a rate of 3°C / min, and the mixture is stirred at a rate of 30 rpm for 30 min. After that, the mixture is left to stand for 24 h, and then centrifuged at a speed of 3000 rpm for 30 min to separate the crystals from the mother liquor. The crystals are then washed with pre-cooled ethanol at -5°C for 3 times to obtain the camphor oil crystals. The mixed salt solution used has sodium chloride (33 g / mL), magnesium sulfate and sodium acetate as solutes, and water as solvent. After adding the mixed salt solution, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 1%, 3% and 2% of the mass of the oil phase, respectively. S5: heating the essential oil crystals to melt, then cooling to room temperature, and then centrifuging, to obtain the high-purity oil camphor tree essential oil.
[0023] Example 3 A method for preparing high-purity oil camphor tree essential oil, comprising the following steps: S1: crushing fresh oil camphor tree leaves into a slurry and loading into a distillation device, then introducing steam with a temperature of 100℃ into the distillation device; passing the steam flowing out of the distillation device into a condensation device to condense, to obtain crude oil camphor tree oil; distillation time is 3h; S2: evaporating and refluxing the crude oil camphor tree oil under the condition of 5kPa for 2h with a reflux ratio of 6:1, to obtain oil camphor tree essential oil; S3: mixing the oil camphor tree essential oil with a low eutectic solvent in a volume ratio of 1:3, stirring at room temperature and then separating, to collect the lower solvent phase; then mixing the solvent phase with water in a volume ratio of 1:2, stirring at room temperature and then separating, to collect the upper oil phase; the low eutectic solvent used is a mixture of tropine alcohol and ethylene glycol in a molar ratio of 1:10; S4: mixing the collected oil phase with ethanol in a volume ratio of 1:3, then adding a mixed salt solution into the mixture, then cooling to -5℃ at a cooling rate of 5℃ / min, stirring at a stirring rate of 45rpm for 60min, then standing for 16h, then centrifuging at a speed of 3000rpm for 30min, to separate the crystals from the mother liquor, and then rinsing the crystals with pre-cooled to -5℃ ethanol for 3 times, to obtain essential oil crystals; the solute of the mixed salt solution used is sodium chloride (33g / mL), magnesium sulfate and sodium acetate, and the solvent is water; after adding the mixed salt solution, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 3%, 2% and 5% of the mass of the oil phase, respectively; S5: heating the essential oil crystals to melt, then cooling to room temperature, and then centrifuging, to obtain the high-purity oil camphor tree essential oil.
[0024] Comparative Example 1 A method for preparing high-purity oil camphor tree essential oil, comprising the following steps: S1: crushing fresh oil camphor tree leaves into a slurry and loading into a distillation device, then introducing steam with a temperature of 100℃ into the distillation device; passing the steam flowing out of the distillation device into a condensation device to condense, to obtain crude oil camphor tree oil; distillation time is 4h; S2: mixing the crude oil camphor tree oil with a low eutectic solvent in a volume ratio of 1:2, stirring at room temperature and then separating, to collect the lower solvent phase; then mixing the solvent phase with water in a volume ratio of 1:2, stirring at room temperature and then separating, to collect the upper oil phase; the low eutectic solvent used is a mixture of tropine alcohol and ethylene glycol in a molar ratio of 1:8; S3: The collected oil phase is mixed with ethanol at a volume ratio of 1:2, and then a mixed salt solution is added to the mixture. The mixture is cooled to -3°C at a cooling rate of 4°C / min, and then stirred at a stirring rate of 40 rpm for 45 min. The mixture is then kept still for 20 h, and then centrifuged at a speed of 3000 rpm for 30 min. The crystals are separated from the mother liquor, and then washed with pre-cooled ethanol at -5°C for 3 times to obtain the essential oil crystals. The solute of the mixed salt solution used is sodium chloride (33 g / mL), magnesium sulfate and sodium acetate, and the solvent is water. After the mixed salt solution is added, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 2%, 1% and 4% of the mass of the oil phase, respectively; S4: The essential oil crystals are heated to melt, and then cooled to room temperature. The high-purity oil camphor essential oil is obtained by centrifugation.
[0025] Comparative Example 2 A method for preparing high-purity oil camphor essential oil, comprising the following steps: S1: Fresh oil camphor leaves are crushed into a slurry and loaded into a distillation device, and then steam at a temperature of 100°C is introduced into the distillation device. The steam flowing out of the distillation device is introduced into a condensation device for condensation to obtain crude oil camphor. The distillation time is 4 h; S2: The crude oil camphor is evaporated and refluxed at a reflux ratio of 6:1 under the condition of 4.5 kPa for 2.5 h to obtain oil camphor essential oil; S3: The oil camphor essential oil is mixed with ethanol at a volume ratio of 1:2, and then a mixed salt solution is added to the mixture. The mixture is cooled to -3°C at a cooling rate of 4°C / min, and then stirred at a stirring rate of 40 rpm for 45 min. The mixture is then kept still for 20 h, and then centrifuged at a speed of 3000 rpm for 30 min. The crystals are separated from the mother liquor, and then washed with pre-cooled ethanol at -5°C for 3 times to obtain the essential oil crystals. The solute of the mixed salt solution used is sodium chloride (33 g / mL), magnesium sulfate and sodium acetate, and the solvent is water. After the mixed salt solution is added, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 2%, 1% and 4% of the mass of the oil camphor essential oil, respectively; S4: The essential oil crystals are heated to melt, and then cooled to room temperature. The high-purity oil camphor essential oil is obtained by centrifugation.
[0026] Comparative Example 3 A method for preparing high-purity oil camphor essential oil, comprising the following steps: S1: Fresh oil camphor leaves are crushed into a slurry and loaded into a distillation device, and then steam at a temperature of 100°C is introduced into the distillation device. The steam flowing out of the distillation device is introduced into a condensation device for condensation to obtain crude oil camphor. The distillation time is 4 h; S2: The crude oil camphor is evaporated and refluxed at a reflux ratio of 6:1 under the condition of 4.5 kPa for 2.5 h to obtain oil camphor essential oil; S3: The camphor oil and the deep eutectic solvent were mixed at a volume ratio of 1:2, and after stirring at room temperature, the lower solvent phase was collected by separation. Then the solvent phase was mixed with water at a volume ratio of 1:2, and after stirring at room temperature, the upper oil phase was collected by separation. The deep eutectic solvent used was a mixture of tropine and ethylene glycol at a molar ratio of 1:8; S4: The collected oil phase was mixed with ethanol at a volume ratio of 1:2, and then a salt solution was added to the mixture. The mixture was cooled at a rate of 4℃ / min to -3℃, and then stirred at a rate of 40 rpm for 45 min. After that, the mixture was kept still for 20 h, and then centrifuged at a speed of 3000 rpm for 30 min to separate the crystals from the mother liquor. The crystals were washed with pre-cooled ethanol at -5℃ for 3 times to obtain the camphor oil crystals. The salt solution used had sodium chloride (33 g / mL) as the solute and water as the solvent. After the addition of the salt solution, the sodium chloride in the system accounted for 2% of the mass of the oil phase. S5: The camphor oil crystals were heated to melt, and then cooled to room temperature. After that, the high-purity camphor oil was obtained by centrifugation.
[0027] Comparative Example 4 A method for preparing high-purity camphor oil, comprising the following steps: S1: Fresh camphor leaves were crushed into a slurry and loaded into a distillation device, and then steam at a temperature of 100℃ was introduced into the distillation device. The steam flowing out of the distillation device was condensed in a condensation device to obtain camphor oil crude product. The distillation time was 4 h. S2: The camphor oil crude product was mixed with ethanol at a volume ratio of 1:2, and then a mixed salt solution was added to the mixture. The mixture was cooled at a rate of 4℃ / min to -3℃, and then stirred at a rate of 40 rpm for 45 min. After that, the mixture was kept still for 20 h, and then centrifuged at a speed of 3000 rpm for 30 min to separate the crystals from the mother liquor. The crystals were washed with pre-cooled ethanol at -5℃ for 3 times to obtain the camphor oil crystals. The mixed salt solution used had sodium chloride (33 g / mL), magnesium sulfate and sodium acetate as the solutes and water as the solvent. After the addition of the mixed salt solution, the sodium chloride, magnesium sulfate and sodium acetate in the system accounted for 2%, 1% and 4% of the mass of the camphor oil crude product, respectively. S3: The camphor oil crystals were heated to melt, and then cooled to room temperature. After that, the high-purity camphor oil was obtained by centrifugation.
[0028] Experimental Example The yield of the camphor oil crude product in the above examples and comparative examples was calculated according to formula (1-1): (1-1); wherein m 油樟油粗品 is the mass of the oil obtained by distillation extraction; and m 油樟叶 is the mass of the camphor leaves used.
[0029] The yield of high-purity Cinnamomum camphora oil in each of the above examples and the comparative example was calculated according to formula (1-2): (1-2); wherein m 高纯度油樟精油 is the mass of high-purity Cinnamomum camphora oil obtained after the freezing crystallization treatment; m 油樟叶 is the mass of Cinnamomum camphora leaves used.
[0030] The yield of Cinnamomum camphora oil and high-purity Cinnamomum camphora oil in each of the above examples and the comparative example is shown in Table 1.
[0031] Table 1 Yield of Cinnamomum camphora oil and high-purity Cinnamomum camphora oil
[0032] The high-purity Cinnamomum camphora oil obtained in each of the above examples and the comparative example was subjected to GC-MS analysis to measure the content of 1,8-cineole and α-terpineol in the high-purity Cinnamomum camphora oil, and the results are shown in Table 2.
[0033] Table 2 Content of 1,8-cineole and α-terpineol in high-purity Cinnamomum camphora oil
[0034] Although the specific embodiments of the present application are described in detail with reference to the examples, it should not be understood as limiting the scope of protection of the patent. Various modifications and variations that can be made by those skilled in the art without creative labor within the scope described in the claims are still within the scope of protection of the patent.
Claims
1. A method for preparing high-purity camphor oil, characterized in that, Includes the following steps: S1: Fresh camphor tree leaves are distilled to extract crude camphor oil; S2: Vacuum distillation is performed on the crude camphor oil to obtain camphor essential oil; S3: Mix camphor oil with a low eutectic solvent, stir, let stand to separate, and collect the lower solvent phase; then mix the solvent phase with water, stir, let stand to separate, and collect the upper oil phase; the low eutectic solvent is a mixture of tropane alcohol and polyol; S4: Mix the collected oil phase with ethanol at a volume ratio of 1:1~3, then add a mixed salt solution to the mixture, cool to -5℃~0℃, stir for 30~60 min, let stand for 16~24 h, then centrifuge to separate the crystals from the mother liquor, and wash the crystals with pre-cooled ethanol to obtain essential oil crystals; the solutes of the mixed salt solution are sodium chloride, magnesium sulfate and sodium acetate, and the solvent is water; S5: Heat the essential oil crystals until they melt, then cool them to room temperature and centrifuge them to obtain high-purity camphor oil.
2. The method for preparing high-purity camphor oil according to claim 1, characterized in that, The distillation extraction in S1 includes the following steps: Fresh camphor tree leaves are crushed into a pulp and placed into a distillation apparatus. Steam at a temperature of 95-100℃ is then introduced into the distillation apparatus. The steam flowing out of the distillation apparatus is then condensed in a condenser to obtain crude camphor oil. The distillation time is 3-5 hours.
3. The method for preparing high-purity camphor oil according to claim 1, characterized in that: Vacuum distillation in S2 includes the following steps: Crude camphor oil is evaporated and refluxed at a reflux ratio of 6:1 for 2-3 hours under 4-5 kPa conditions to obtain camphor essential oil.
4. The method for preparing high-purity camphor oil according to claim 1, characterized in that: The eutectic solvent is prepared by mixing tropinol and a polyol in a molar ratio of 1:5 to 10; the polyol is ethylene glycol or 1,3-propanediol.
5. The method for preparing high-purity camphor oil according to claim 4, characterized in that: In S3, camphor oil and a low-eutectic solvent are mixed at a volume ratio of 1:1 to 3.
6. The method for preparing high-purity camphor oil according to claim 4, characterized in that: The volume ratio of solvent phase to water in S3 is 1:1~2.
7. The method for preparing high-purity camphor oil according to claim 1, characterized in that: After adding the mixed salt solution to S4, the sodium chloride, magnesium sulfate and sodium acetate in the system account for 1-3%, 1-3% and 2-5% of the mass of the oil phase, respectively.
8. The method for preparing high-purity camphor oil according to claim 1, characterized in that: The cooling rate in S4 is 3~5℃ / min; the stirring speed is 30~45rpm.
9. The method for preparing high-purity camphor oil according to claim 1, characterized in that: The stirring time in S4 is 45 minutes; the holding time is 20 hours.
10. The method for preparing high-purity camphor oil according to claim 1, characterized in that: The temperature of the pre-cooled ethanol is -5°C.