A high-efficiency extraction method of dusha essential oil

Abstract

The application provides a high-efficiency extraction method of Ledum oil, and belongs to the field of plant essential oil extraction.The method comprises the following steps: (1) removing leaves; (2) uniformly mixing n-decanoic acid, ethanol and water, naturally standing, vortex centrifuging, taking out the upper phase to obtain a supramolecular solvent; (3) soaking Ledum leaves in the supramolecular solvent, airing and then distilling; (4) connecting a catalytic tube to the steam outlet of a distillation chamber, filling the tube with metal catalysts, and performing catalytic reaction; (5) after the catalytic reaction, the mixed steam passes through a condenser tube and is collected in an oil-water separator, and a separation agent is added to change the solvent constant of the essential oil in water, so as to improve the yield of the essential oil.The method can not only improve the Ledum oil yield and the Ledum oil yield, but also improve the quality of the Ledum oil, and the Ledum oil has more mellow aroma, meets the development trend of the current domestic and foreign consumer market, and can better meet the needs of consumers.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plant essential oil extraction, in particular to a high-efficiency extraction method of Ledum palustre L. essential oil. BACKGROUND

[0002] Ledum palustre L. is a shrub of the genus Ledum in the family Ericaceae, which is a traditional Chinese medicinal material and an important spice plant. Ledum palustre L. is distributed in the temperate or cold temperate zone of the Northern Hemisphere, mainly in Northeast China (Daxing'anling, Xiaoxing'anling and Changbai Mountain), Japan, Siberia, North America and Europe. Ledum palustre L. is widely used in medicine, and the extract of its tender branches and leaves has analgesic, expectorant, desensitizing and diuretic effects.

[0003] Ledum palustre L. has a strong aromatic odor and can be used as medicine and extracted essential oil. Essential oil can be extracted from the whole plant of Ledum palustre L., especially from flowers and leaves. Ledum palustre L. essential oil has the effects of relieving cough, killing bacteria, promoting transdermal absorption, killing mites and driving insects, and also has inhibitory activity against various fungi and bacteria, and has been used in daily life, medical treatment, spice production and other fields. However, the extraction rate of Ledum palustre L. essential oil is low at present, and the research in the field of cosmetics is less.

[0004] Using supramolecular solvent to extract plant active ingredients is a new development trend, but there are many combinations of supramolecular solvents, and the dissolution effect of different plant extracts is very different. For example, CN116173548A provides a method for extracting soapnut saponin by using supramolecular solvent, which is formed by n-octanoic acid, ethanol or acetonitrile and water, but when the inventors use it to extract Ledum palustre L. essential oil, it is found that the effect of n-octanoic acid is obviously not as good as that of n-decanoic acid.

[0005] In addition, the current method of mixing supramolecular solvent with the plant to be extracted is usually water vapor distillation coupling, but this method cannot well remove macromolecular impurities such as saponins, sugars and alkaloids in the raw materials. Therefore, it is necessary to develop a more efficient preparation process of Ledum palustre L. essential oil to solve the defects of the prior art. SUMMARY

[0006] In view of the above problems existing in the prior art, the present application provides a high-efficiency extraction method of Ledum palustre L. essential oil. This method not only improves the oil extraction rate and yield of Ledum palustre L. essential oil, but also makes the quality of Ledum palustre L. essential oil higher and the aroma more mellow, which meets the development trend of the domestic and foreign consumer market and better meets the needs of consumers.

[0007] The technical scheme of the present application is as follows:

[0008] A high-efficiency extraction method of Ledum palustre L. essential oil, comprising the following steps:

[0009] (1) Leaf removal: fresh Litsea cubeba branches and leaves are subjected to leaf removal treatment to obtain Litsea cubeba leaves;

[0010] (2) Preparation of supramolecular solvent: after uniform mixing of n-decanoic acid, ethanol and water, natural standing is performed, followed by vortex centrifugation, and the system is divided into two phases, and the upper phase is taken out to obtain the supramolecular solvent;

[0011] (3) Soaking and distillation: the Litsea cubeba leaves are soaked with the supramolecular solvent, and then dried and placed in a distillation chamber for distillation;

[0012] (4) Catalytic reaction: a catalytic tube is connected to the steam outlet of the distillation chamber, and the tube is filled with a metal catalyst, so that the mixed steam after distillation passes through the catalytic tube for catalytic reaction;

[0013] (5) Oil-water separation: the mixed steam after catalytic reaction is collected in an oil-water separator through a condenser tube to obtain an oil-water mixture, and then a separation agent is added to change the solvent constant of the essential oil in water to improve the yield of the essential oil.

[0014] Preferably, the natural standing time in step (2) is 30 min to 2 h.

[0015] Preferably, in the supramolecular solvent of step (2), the volume ratio of n-decanoic acid is 5% to 20%, the total volume ratio of ethanol is 10% to 30%, and the rest is water.

[0016] Preferably, the soaking time of the supramolecular solvent in step (3) is 2 to 10 h.

[0017] Preferably, the distillation time in step (3) is 2 to 5 h.

[0018] Preferably, the metal catalyst in step (4) is copper.

[0019] Preferably, the copper is in the form of copper foil, copper sheet or copper mesh.

[0020] More preferably, a catalytic tube made of multiple layers of copper mesh or a catalytic tube made of copper sheet can be used.

[0021] Preferably, the catalytic reaction time in step (4) is 0.5 to 2 h.

[0022] Preferably, the separation agent in step (5) is one of NaCl or KCl, and the amount is 0.1 to 5 wt% of the oil-water mixture.

[0023] More preferably, NaCl or KCl is added in solid form, such as powder form.

[0024] Preferably, the mixing time of the separation agent with the oil-water mixture in step (5) is 1 to 3 h.

[0025] The beneficial technical effects of the present application are that:

[0026] 1. The present application uses supramolecular solvent to soak the leaves of Ledum palustre for the first time, which aims to dissolve macromolecules such as saponins, sugars and alkaloids in Ledum palustre, so as to reduce the content of impurities mixed in the essential oil and improve the quality of the essential oil.

[0027] 2. The present application combines catalytic principle and uses metal catalysis to convert part of the impure acid and fusel alcohol into high-grade fatty oil through esterification reaction, so as to improve the yield of essential oil and make the quality of essential oil more high and the aroma more mellow. Copper is commonly used as a catalyst in synthesis reactions, but it has not been used in steam distillation before, so this technology is the first of its kind.

[0028] 3. The sodium chloride commonly used in the prior art is fed into the distillation kettle together with the fermentation product to control the reaction conditions in a neutral environment or to precipitate trans aldehyde and acid in the water phase. However, the present application is different. The addition of NaCl or KCl in the oil-water separator can reduce the water solubility of the essential oil, thereby improving the yield of the essential oil. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a process flow chart of the efficient extraction method of Ledum palustre essential oil according to the present application. DETAILED DESCRIPTION

[0030] The present application will be described in detail below in conjunction with the drawings and examples. Obviously, the described examples are only a part of the examples of the present application, but not all the examples. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] Example 1

[0032] This example provides an efficient extraction method of Ledum palustre essential oil, and the specific process is as shown in Figure 1

[0033] (1) Leaf removal: fresh Ledum palustre branches and leaves are subjected to leaf removal treatment to obtain Ledum palustre leaves.

[0034] (2) Preparation of supramolecular solvent: 10% n-decanoic acid, 15% ethanol and 75% water are uniformly mixed and naturally placed for 1 h, and then vortexed and centrifuged, the system is divided into two phases, the upper phase is taken out to obtain the supramolecular solvent; wherein the vortex centrifuge is a multi-constant instrument LD24R, the centrifugal speed is 4000xg, the centrifugal time is 15 min, and the centrifugal temperature is 25℃.

[0035] ​(3) Soaking and distillation: 400 g of the leaves of Ledum palustre L. obtained in step (1) were soaked with the supramolecular solvent obtained in step (2) for 6 h, and then dried and placed in a distillation chamber. 12 L of water was added to the water chamber, and the water was heated to boiling at 100 ℃, and then distilled for 2 h.

[0036] (4) Catalytic reaction: a catalytic tube made of copper sheets was connected to the steam outlet, which was equivalent to filling the tube with copper catalyst. The mixed steam after distillation was allowed to pass through the catalytic tube for catalytic reaction, and the catalytic time was 1 h.

[0037] (5) Oil-water separation: the mixed steam after catalytic reaction was water vapor and Ledum palustre essential oil, which entered the condensation tower together. After the water vapor was liquefied, it flowed out of the condensation tower together with the essential oil, passed through the condensation pipe, and then gathered in the oil-water separator to obtain 36.28 g of oil-water mixture. 0.4 g of NaCl powder was added to the oil-water separator, and the mixture was left to stand for 2 h. Finally, 8.63 g of Ledum palustre essential oil was obtained, and the yield of essential oil was 2.16%.

[0038] Example 2

[0039] The present embodiment provides a high-efficiency extraction method for Ledum palustre essential oil, and the specific process is as shown in Figure 1

[0040] (1) Leaf removal: fresh Ledum palustre branches and leaves were subjected to leaf removal treatment to obtain Ledum palustre leaves.

[0041] (2) Preparation of supramolecular solvent: 20% n-decanoic acid, 25% ethanol, and 55% water were uniformly mixed, and then naturally stood for 2 h. Then, vortex centrifugation was performed, and the system was divided into two phases. The upper phase was taken out to obtain the supramolecular solvent.

[0042] (3) Soaking and distillation: 400 g of the leaves of Ledum palustre L. obtained in step (1) were soaked with the supramolecular solvent obtained in step (2) for 3 h, and then dried and placed in a distillation chamber. 12 L of water was added to the water chamber, and the water was heated to boiling at 100 ℃, and then distilled for 3 h.

[0043] (4) Catalytic reaction: a catalytic tube made of multiple layers of copper mesh was connected to the steam outlet, and the mixed steam after distillation was allowed to pass through the catalytic tube for catalytic reaction, and the catalytic time was 0.5 h.

[0044] (5) Oil-water separation: the mixed steam after catalytic reaction was water vapor and Ledum palustre essential oil, which entered the condensation tower together. After the water vapor was liquefied, it flowed out of the condensation tower together with the essential oil, passed through the condensation pipe, and then gathered in the oil-water separator to obtain 38.57 g of oil-water mixture. Then, 0.4 g of KCl powder was added to the oil-water separator, and the mixture was left to stand for 1 h. Finally, 7.89 g of Ledum palustre essential oil was obtained, and the yield of essential oil was 1.97%.

[0045] Example 3 ​

[0046] The embodiment provides a high-efficiency extraction method of Ledum essential oil, and a specific process is as shown in the figure. Figure 1

[0047] (1) Leaf removal: fresh Ledum branches and leaves are subjected to leaf removal treatment to obtain Ledum leaves.

[0048] (2) Preparation of supramolecular solvent: 5% n-decanoic acid, 10% ethanol and 85% water are uniformly mixed, and then naturally placed for 30 min, followed by vortex centrifugation, and the system is divided into two phases, and the upper phase is taken out to obtain the supramolecular solvent.

[0049] (3) Soaking and distillation: 400 g of Ledum leaves obtained in step (1) is soaked with the supramolecular solvent obtained in step (2) for 10 h, and then dried and placed in a distillation chamber, 12 L of water is added to the water chamber, the water is heated to boiling at 100 ℃, and distillation is performed for 5 h.

[0050] (4) Catalytic reaction: a catalytic pipe made of a multilayer copper mesh is connected to the steam outlet, so that the mixed steam after distillation passes through the catalytic pipe for catalytic reaction, and the catalytic time is 2 h.

[0051] (5) Oil-water separation: the mixed steam after catalytic reaction is water vapor and Ledum essential oil, which are introduced into a condensation tower together; the water vapor is liquefied and flows out from the condensation tower together with the essential oil, is collected in an oil-water separator through a condensation pipe, and 38.22 g of oil-water mixture is obtained; then 1.9 g of NaCl powder is added to the oil-water separator, and the mixture is left to stand for 3 h, and finally 8.73 g of Ledum essential oil is obtained, and the yield of the essential oil is 2.18%.

[0052] Comparative Example 1: Screening of solvents

[0053] The present comparative example is divided into four groups, wherein the preparation method of the essential oil in the first group is as follows:

[0054] (1) Leaf removal: fresh Ledum branches and leaves are subjected to leaf removal treatment to obtain Ledum leaves;

[0055] (2) Distillation: 400 g of Ledum leaves is placed in a distillation chamber, 12 L of water is added to the water chamber, the water is heated to boiling at 100 ℃, and distillation is performed for 2 h;

[0056] (3) Condensation and separation: water vapor and Ledum essential oil are introduced into a condensation tower together, the water vapor is liquefied and flows out from the condensation tower together with the essential oil, and the essential oil is finally obtained by collecting in an oil-water separator.

[0057] The preparation methods of the essential oils in the second, third and fourth groups are different from those in the first group in that:

[0058] ​The water, ethanol and supramolecular solvent were used as experimental solvents, i.e. 400 g of the leaves of Ledum palustre obtained in step (1) were soaked in the three experimental solvents for 6 h, and then dried to carry out the distillation and condensation separation steps described in steps (2) and (3). The supramolecular solvent was prepared by mixing 5% n-decanoic acid, 10% ethanol and 85% water. The oil yields of different groups are shown in Table 1.

[0059] Table 1

[0060] Number Solvent selection Essential oil collection amount (g) Essential oil yield (%) 1 None 2.59 0.65 2 Water 2.95 0.74 3 Ethanol 2.87 0.72 4 5% n-decanoic acid, 10% ethanol, 85% water 4.32 1.08

[0061] The comparison of the four treatment methods by direct distillation and distillation after soaking in different solvents (water, ethanol, supramolecular solvent) for a period of time shows that the collection rate of essential oil after soaking for a period of time and then distillation is significantly improved; the essential oil yield after soaking in the supramolecular solvent is the highest, reaching 1.08%.

[0062] Comparative Example 2: Screening of Supramolecular Solvent

[0063] The preparation method of this comparative example is similar to that of Group 4 of Comparative Example 1, except that the n-decanoic acid therein is replaced by n-hexanoic acid and n-octanoic acid to obtain Ledum palustre essential oils 5, 6 and 7. The oil yields of different groups are shown in Table 2.

[0064] Table 2

[0065] Number Supramolecular solvent Essential oil collection amount (g) Essential oil yield (%) 5 n-hexanoic acid 3.55 0.89 6 n-octanoic acid 3.43 0.86 7 n-decanoic acid 4.42 1.11

[0066] Through the screening of different alkanoic acids (n-hexanoic acid, n-octanoic acid and n-decanoic acid), it is found that the essential oil yield after soaking in n-decanoic acid is the highest, reaching 1.11%.

[0067] Comparative Example 3: Determination of Supramolecular Solvent Ratio

[0068] The preparation method of this comparative example is similar to that of Group 4 of Comparative Example 1, except that the n-decanoic acid, ethanol and water are mixed in the volume ratio shown in Table 3 to prepare a supramolecular solvent, and Ledum palustre essential oils 8, 9, 10 and 11 are obtained. The essential oil yields of different treatments are shown in Table 3.

[0069] Table 3

[0070] Number Volume ratio (n-decanoic acid, ethanol, water) Essential oil collection amount (g) Essential oil yield (%) 8 5％：10％：85％ 4.37 1.09 9 10％：15％：75％ 5.25 1.31 10 15％：20％：65％ 3.73 0.93 11 10％：10％：80％ 4.16 1.04

[0071] Through the screening of the volume ratio of the supramolecular solvent, it is found that there is a large difference in the essential oil yield after treatment with different volume ratios of the supramolecular solvent, and the essential oil yield is the highest, reaching 1.31%, when the supramolecular solvent formed by 10% n-decanoic acid, 15% ethanol and 75% water is used.

[0072] Comparative Example 4: Determination of Catalyst

[0073] The preparation method of this comparative example is as follows:

[0074] (1) Leaf removal: fresh Ledum branch leaves are subjected to leaf removal treatment to obtain Ledum leaves;

[0075] (2) 400g of Ledum leaves are placed in a distillation chamber, 12L of water is added to the water chamber, the water is heated to boiling at 100°C, and distillation is carried out for 2h;

[0076] (3) A catalytic tube filled with metal catalyst (iron, copper, aluminum) is connected to the steam outlet, and the mixed steam after distillation is allowed to pass through the catalytic tube for catalytic reaction;

[0077] (4) Water vapor and Ledum essential oil enter the condensation tower together, the water vapor is liquefied and flows out of the condensation tower together with the essential oil, and is collected in an oil-water separator to obtain Ledum essential oil 12, 13, and 14.

[0078] The oil yields of different preparation methods are shown in Table 4.

[0079] Table 4

[0080] Number Catalyst Essential oil collection amount (g) Essential oil yield (%) 1 None 2.59 0.65 12 Iron 2.73 0.68 13 Copper 3.85 0.96 14 Aluminum 3.01 0.75

[0081] Through the screening of different catalysts (iron, copper, aluminum), the results show that the use of different catalysts has obvious differences in essential oil yield and aroma. The essential oil yield is highest after using copper catalyst, which is 0.96%.

[0082] Comparative Example 5: Determination of Catalyst

[0083] The preparation method of this comparative example is as follows:

[0084] (1) Leaf removal: fresh Ledum branch leaves are subjected to leaf removal treatment to obtain Ledum leaves;

[0085] (2) 400g of Ledum leaves are placed in a distillation chamber, 12L of water is added to the water chamber, the water is heated to boiling at 100°C, and distillation is carried out for 2h;

[0086] (3) A catalytic tube filled with copper foil, copper sheet and multi-layer copper mesh is connected to the steam outlet, and the mixed steam after distillation is allowed to pass through the catalytic tube for catalytic reaction;

[0087] (4) Water vapor and Ledum essential oil enter the condensation tower together, the water vapor is liquefied and flows out of the condensation tower together with the essential oil, and is collected in an oil-water separator to obtain Ledum essential oil 15, 16, and 17.

[0088] The oil yields of different preparation methods are shown in Table 5.

[0089] Table 5

[0090]

[0091]

[0092] Through the screening of catalytic tubes made of different materials (copper foil, copper sheet, multi-layer copper mesh), it is found that the yield of essential oil is slightly different when using catalytic tubes made of different materials, and the yield of essential oil is the highest when using a catalytic tube made of multi-layer copper mesh, which is 1.05%.

[0093] Comparative Example 6: Screening of oil-water separation additives

[0094] The preparation method of the present comparative example is as follows:

[0095] (1) Leaf removal: fresh Ledum branch leaves are subjected to leaf removal treatment to obtain Ledum leaves;

[0096] (2) Put 400g of Ledum leaves into the distillation chamber, add 12L of water in the water chamber, heat the water to boiling point 100℃, and distill for 2h;

[0097] (3) Water vapor and essential oil of Ledum enter the condensation tower together, and after the water vapor is liquefied, it flows out from the condensation tower together with the essential oil, is collected in the oil-water separator, and 0.4g of NaCl, KCl and CaCl2 are added respectively in the oil-water separator, numbered as 18, 19 and 20 groups, and finally the essential oil of Ledum is obtained.

[0098] The oil yield of different preparation methods is shown in Table 6.

[0099] Table 6

[0100] Number Separating agent Essential oil collection amount (g) Essential oil yield (%) 1 None 2.59 0.65 18 NaCl 4.39 1.11 19 KCl 3.66 0.92 20 CaCl2 3.28 0.82

[0101] Through the screening of separation agents (NaCl, KCl, CaCl2), it is found that the yield of essential oil is obviously different when using different separation agents, and the yield of essential oil is the highest when using NaCl as the separation agent, which is 1.11%.

[0102] Although the embodiments of the present application have been disclosed as above, they are not limited to the application listed in the specification and embodiments, and can be fully applied to various fields suitable for the present application. For those skilled in the art, for those skilled in the art, various changes, modifications, replacements and modifications can be made to these embodiments without departing from the principles and spirits of the present application, and therefore the present application is not limited to specific details without departing from the general concept defined by the claims and equivalent ranges.

Claims

1. A method for efficient extraction of Ledum essential oil, characterized by, The method comprises the following steps: (1) Leaf removal: fresh Ledum branch leaves are subjected to leaf removal treatment to obtain Ledum leaves; (2) Preparation of supramolecular solvent: after uniform mixing of n-decanoic acid, ethanol and water, natural standing is performed, then vortex centrifugation is performed, the system is divided into two phases, the upper phase is taken out, and a supramolecular solvent is obtained; (3) Soaking and distillation: Ledum leaves are soaked with the supramolecular solvent, then are dried and placed in a distillation chamber for distillation; (4) Catalytic reaction: a catalytic tube is connected to the steam outlet of the distillation chamber, the tube is filled with a metal catalyst, and the mixed steam after distillation is subjected to catalytic reaction through the catalytic tube; (5) Oil-water separation: the mixed steam after catalytic reaction is collected in an oil-water separator through a condenser tube, an oil-water mixture is obtained, then a separation agent is added to change the solvent constant of essential oil in water, so that the yield of essential oil is improved; In the supramolecular solvent of step (2), the volume ratio of n-decanoic acid is 5%-20%, the total volume ratio of ethanol is 10-30%, and the rest is water; The metal catalyst of step (4) is copper.

2. The method of claim 1, wherein, The natural standing time of step (2) is 30 min-2 h.

3. The method of claim 1, wherein, The supramolecular solvent soaking time of step (3) is 2-10 h.

4. The method of claim 1, wherein, The distillation time of step (3) is 2-5 h.

5. The method of claim 1, wherein, The catalytic reaction time of step (4) is 0.5-2 h.

6. The method of claim 1, wherein, The separation agent of step (5) is one of NaCl or KCl, and the amount is 0.1-5 wt% of the oil-water mixture.

7. The method of claim 1, wherein, The mixing time of the separation agent with the oil-water mixture of step (5) is 1-3 h.

Images