An extraction device and extraction method for star anise essential oil

Abstract

The present application discloses an extraction device and an extraction method for star anise essential oil, belonging to the technical field of vegetable oil extraction. The extraction device provided by the present application includes a round-bottom flask, an air condenser, a distillation head, a condenser, a receiving tube, and a receiving bottle; the mouth of the round-bottom flask is connected to the bottom of the air condenser; the top of the air condenser is connected to the bottom tube of the distillation head; the side tube of the distillation head is connected to the top of the condenser; the bottom of the condenser is connected to the top of the receiving tube; the tail of the receiving tube is inserted into the receiving bottle; a polymer membrane is loaded at the top of the air condenser. The extraction device and the extraction method for star anise essential oil provided by the present application solve the problems of long time consumption, large steam consumption, and high energy consumption existing in the traditional extraction process. At the same time, the extraction rate of star anise oil and the extraction rate of the active ingredient anethole are greatly improved.

Description

Technical Field

[0001] This application belongs to the technical field of vegetable oil extraction, and particularly relates to an extraction device and an extraction method for star anise essential oil. Background Art

[0002] Star anise (Fructus Anisi Stellati), commonly known as star anise, five-spice star anise, aniseed, etc., is a plant of the genus Illicium in the family Schisandraceae. Star anise essential oil is a volatile aromatic substance extracted from star anise by steam distillation, extrusion, cold soaking or solvent extraction methods. The fruit is a famous flavoring spice with a sweet taste. It is also used medicinally, with the functions of dispelling wind and regulating qi, and regulating the stomach. It is used for cold vomiting, abdominal cold pain, stomach distension, etc. However, excessive consumption can damage the eyes and cause sores. The pericarp, seeds and leaves all contain aromatic oil. Star anise essential oil is an important raw material for the manufacture of cosmetics, pharmaceuticals, sweet liqueurs, beer and the food industry.

[0003] The extraction methods of star anise essential oil include steam distillation, solvent extraction and supercritical fluid extraction, etc. Among them, the solvent extraction method uses organic solvents such as ethanol or hexane to dissolve the oil components in plants, but may introduce residual solvents, affecting the purity and safety of the products. Supercritical fluid extraction technology can efficiently extract the active components in plants at low temperature, reduce the degradation of thermosensitive components, and does not produce harmful residues, and has gradually attracted attention in recent years. However, this method often requires very high pressure, which poses a great test to experimental equipment, has high costs and energy consumption, and is difficult to scale up. Therefore, steam distillation has become the most commonly used extraction technology. This technology is to introduce steam into organic substances that are insoluble or poorly soluble in water but have certain volatility, so that the organic substance can be distilled out together with the steam at a temperature below 100°C. It is commonly used in the following situations: high-boiling organic substances that will decompose during distillation at atmospheric pressure; separating organic substances from a large amount of resinous impurities or non-volatile impurities; separating adsorbed liquids from reaction mixtures with a lot of solids; extraction of natural products, such as essential oils and certain alkaloids. The steam distillation technology can effectively retain the aromatic components and bioactive components of plants, is not only efficient, but also relatively environmentally friendly, and is suitable for large-scale production.

[0004] The traditional steam distillation method for extracting essential oils has the advantages of mild extraction conditions, high efficiency, impurity removal, simple operation and wide application range, etc. However, it also has the disadvantages of low extraction efficiency, long time, low energy utilization rate, large amount of water resources used and low utilization rate, high emulsification of the obtained distillate, loss of thermosensitive components, and complex post-treatment, etc. Therefore, it is necessary to improve the utilization efficiency of steam and preliminarily separate oil and water to achieve efficient extraction.

[0005] Traditional separation techniques are difficult to achieve simple and efficient gas-phase separation or are not easily applied to teaching experiments due to their high costs. Fortunately, membrane separation technology can well solve this problem. Moreover, due to its characteristics such as high separation efficiency, high selectivity, and environmental friendliness, membrane preparation technology and membrane-based separation processes have developed rapidly in China in the past two decades. Common membrane material matrices include carbon, ceramics, polymers, gels, metal networks, and biomass, etc. Scientists enable them to be applied to different production fields through microstructural design or surface modification of membrane materials, such as the filtration of particles in sewage and oil-water separation, etc.

[0006] Therefore, how to improve the experimental device for extracting star anise oil by the traditional steam distillation method using membrane separation technology is of great significance for solving key problems such as low yield of star anise oil extraction, long experimental time, and high energy consumption. Summary of the Invention

[0007] To overcome the problems of long time consumption, large steam consumption, high energy consumption, etc. existing in the above-mentioned prior art, this application provides an extraction device and an extraction method for star anise essential oil. Using the said device and method not only saves the extraction time, improves the essential oil yield of star anise, but also improves the extraction rate of anethole, the main active ingredient of star anise essential oil.

[0008] To achieve the above-mentioned invention purposes, this application provides the following technical solutions:

[0009] On the one hand, this application provides an extraction device for star anise essential oil, including a round-bottom flask (1), an air condenser (2), a distillation head (3), a condenser (4), a receiving tube (5), and a receiving flask (6);

[0010] The mouth of the round-bottom flask (1) is connected to the bottom of the air condenser (2);

[0011] The top of the air condenser (2) is connected to the bottom tube of the distillation head (3);

[0012] The side tube of the distillation head (3) is connected to the top of the condenser (4);

[0013] The bottom of the condenser (4) is connected to the top of the receiving tube (5);

[0014] Insert the tail of the receiving tube (5) into the receiving flask (6);

[0015] The top of the air condenser (2) is loaded with a polymer membrane (7).

[0016] Optionally, the bottom of the air condenser (2) is loaded with filter paper (8).

[0017] Optionally, a thermometer (9) is inserted into the top of the distillation head (3).

[0018] In a second aspect, the present application provides a method for extracting star anise essential oil, which is carried out using the above-mentioned extraction device and includes the following steps:

[0019] (1) Crush star anise to obtain star anise powder;

[0020] (2) Add distilled water and zeolite into a round-bottom flask, and install an air condenser at the bottle mouth;

[0021] (3) Fill a filter paper at the bottom of the air condenser, place the star anise powder on the filter paper, and then load a polymer membrane at the top of the air condenser;

[0022] (4) Install a distillation head, a condenser, a receiving tube, and a receiving bottle in sequence, and insert a thermometer into the top of the distillation head;

[0023] (5) Pass in cooling water, enter from the lower inlet of the condenser and flow out from the upper outlet, heat the round-bottom flask, start distillation, and stop when the distillate is clear and transparent, the flow rate decreases, and there are no more oil droplets of organic substances, reaching the distillation end point. Turn off the heat source and stop passing in cooling water after the device cools down;

[0024] (6) After the distillate cools to room temperature, remove the receiving bottle, add table salt, stir well, and let it stand to obtain a mixed solution;

[0025] (7) Pour the mixed solution into a pear-shaped separating funnel, add ethyl acetate for extraction, repeat the extraction operation 2 - 4 times, discard the water layer, combine the ester layers, carry out drying and distillation in sequence, distill out the ethyl acetate, and collect the residue to obtain star anise essential oil.

[0026] Optionally, in step (1), the particle size of the star anise powder is 100 - 150 μm;

[0027] The dosage of the star anise powder is 10 - 30 g.

[0028] Optionally, in step (1), the particle size of the star anise powder independently selects any value or the range value between any two of 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm;

[0029] The dosage of the star anise powder independently selects any value or the range value between any two of 10 g, 15 g, 20 g, 25 g, 30 g.

[0030] In this application, star anise is crushed to a particle size of 100-150 μm by means of nodular crushing, which can promote the dissolution of the active ingredients in star anise without damaging the structure of the active ingredients in star anise, thereby improving the extraction rate of anethole.

[0031] Optionally, in step (2), the added volume of the distilled water is 2 / 3-3 / 4 of the volume of the round-bottom flask;

[0032] The dosage of the zeolite is 2-4 grains.

[0033] Preferably, in step (2), the added volume of the distilled water is 3 / 4 of the volume of the round-bottom flask;

[0034] The dosage of the zeolite is 3 grains.

[0035] In this application, the steam transmission path is shortened. The star anise feeding device is changed from a three-necked flask to an air condenser directly connected to the steam generating device, shortening the distance between the steam generating device and the substance to be distilled to reduce the heat loss of the steam during transmission. In addition, if the steam condenses in the air condenser, partial reflux will be formed (about 2-3 drops of partial reflux liquid per second), and the water condensed in the air condenser will flow back into the flask for reheating and evaporation, improving the utilization rate of water vapor.

[0036] Optionally, in step (3), the pore size of the filter paper is smaller than the particle size of the star anise powder.

[0037] Optionally, the polymer membrane is a single-layer membrane.

[0038] In this application, through experiments, it is found that membrane materials with two or more layers will greatly reduce the water vapor flux, making it difficult to drive the oil droplets to migrate to the cooling device, resulting in a low yield of the distilled product collected in the receiving flask. Therefore, a single-layer membrane is selected in this application.

[0039] Optionally, the polymer membrane is a polytetrafluoroethylene hydrophobic membrane.

[0040] Optionally, the pore size of the polytetrafluoroethylene hydrophobic membrane is 0.4-0.5 μm.

[0041] Optionally, the pore size of the polytetrafluoroethylene hydrophobic membrane is 0.45 μm.

[0042] In this application, through experiments, it is found that the smaller the pore size of the membrane, the smaller the size of the molecules or particles that can pass through. Therefore, larger molecules or particles cannot pass through, resulting in a decrease in the overall passing rate. Moreover, small pore sizes will increase the flow resistance of the fluid within the membrane, thereby excessively weakening the apparent migration rate of the fluid. It is difficult for water vapor to drive the continuous migration of the oil phase across the membrane, thus reducing the collection amount. The concentration gradient formed on both sides of the membrane may lead to concentration polarization phenomena, especially when the pore size of the membrane is small, and the polarization phenomenon will be more obvious, thereby affecting the permeation performance of the membrane. In addition, membranes with small pore sizes may have higher selectivity and can effectively block certain substances. Although this can improve the separation efficiency, it may also reduce the overall yield. This application finds that membranes with a pore size in the range of 0.4 - 0.5 μm have better effects, especially the polytetrafluoroethylene hydrophobic membrane with a pore size of 0.45 μm has the best effect.

[0043] Optionally, in step (5), during the distillation process, control the temperature of the thermometer to be 94 - 96 °C;

[0044] When an oily liquid flows into the receiving flask, adjust the heating voltage to control the flow rate of the distillate to be 3 - 5 s / drop.

[0045] Preferably, in step (5), during the distillation process, control the temperature of the thermometer to be 95 °C;

[0046] When an oily liquid flows into the receiving flask, adjust the heating voltage to control the flow rate of the distillate to be 4 s / drop.

[0047] In this application, since the polymer membrane prevents the steam from escaping, the flow rate of the distillate is controlled to be 3 - 5 s per drop, and optimally 4 s per drop.

[0048] Optionally, in step (6), the dosage ratio of the salt to the fraction in the receiving flask is 3 - 3.5 g:10 mL;

[0049] The standing time is 10 - 20 min.

[0050] Optionally, in step (6), the dosage ratio of the salt to the fraction in the receiving flask independently selects any value or the range value between any two of 3 g:10 mL, 3.1 g:10 mL, 3.2 g:10 mL, 3.3 g:10 mL, 3.4 g:10 mL, 3.5 g:10 mL;

[0051] The standing time independently selects any value or the range value between any two of 10 min, 15 min, 20 min.

[0052] Optionally, in step (7), the dosage of ethyl acetate is 20 - 40% of the volume of the mixed solution;

[0053] The extraction time is 10 - 20 min per time.

[0054] Optionally, in step (7), the dosage of ethyl acetate is independently selected from any value of 20%, 30%, 40% of the volume of the mixed solution or the range value between any two of them;

[0055] The extraction time is independently selected from any value of 10 min per time, 15 min per time, 20 min per time or the range value between any two of them.

[0056] Optionally, in step (7), the drying is carried out with anhydrous sodium sulfate;

[0057] The dosage of anhydrous sodium sulfate is 15 - 20% of the mass of the combined ester layer.

[0058] Optionally, the dosage of anhydrous sodium sulfate is independently selected from any value of 15%, 16%, 18%, 20% of the mass of the combined ester layer or the range value between any two of them.

[0059] Optionally, in step (7), the distillation temperature is 70°C - 90°C;

[0060] The distillation time is 1 - 2 h.

[0061] Optionally, in step (7), the distillation temperature is independently selected from any value of 70°C, 80°C, 90°C or the range value between any two of them;

[0062] The distillation time is independently selected from any value of 1 h, 1.5 h, 2 h or the range value between any two of them.

[0063] Compared with the prior art, the present application has the following beneficial effects:

[0064] (1) The extraction device of star anise essential oil provided by the present application uses the selective permeability of the hydrophobic membrane material to preliminarily separate the mixed vapor to increase the mass fraction of the oil phase in the distillate. Due to the hindrance of the mass transfer of water vapor, the steam transmission path before the hydrophobic membrane is relatively closed for water vapor. According to the ideal gas state equation, with continuous heating and boiling, the gas pressure in this section of the path will rise significantly and the boiling point of water will be increased, that is, the temperature of water vapor and even the whole system will be increased, which will undoubtedly also increase the vapor pressure of the substance to be separated and make it easier to be distilled out. Water vapor has a certain flux at the hydrophobic membrane due to its own pressure and mixing with oil gas. Although this makes the present application unable to directly obtain high-purity products, it can effectively drive the migration of oil gas to the condenser. The water vapor is recycled by using the reflux principle, and the condensation of water vapor in the system also helps to keep warm and maintain the stability of the vapor pressure of each component during the separation process.

[0065] (2) The extraction device of star anise essential oil provided by this application reduces the complexity of the traditional device, reducing the number of required glass instruments from 8 types to 7 types; the overall device is more concise, the number of required iron stands is reduced from 3 to 2, and the floor area is reduced; the steam transmission path is shortened, and the star anise material loading device is changed from a three-neck flask to an air condenser directly connected to the steam generating device, shortening the distance between the steam generating device and the substance to be distilled to reduce the heat loss of steam during transmission. In addition, if the steam condenses in the material loading device, partial reflux will be formed (about 2 - 3 drops of partial reflux liquid per second). The condensed water in the material loading device will flow back into the flask for reheating and evaporation, improving the utilization rate of water vapor; reducing the complexity and risk during operation. In traditional experiments, the stopcock needs to be frequently opened, otherwise it is easy to cause a large amount of water to accumulate in the material loading device, reducing the distillation effect, but burns may be caused when opening the stopcock. In the experiment of this application, the glass conduit is omitted, and the partial reflux in the air condenser can also avoid liquid accumulation or uneven flow, thereby improving the overall separation performance and making the experiment simpler and safer.

[0066] (3) The extraction method of star anise essential oil provided by this application, through the combination of crushing, membrane separation technology and steam distillation method, not only saves extraction time, but also reduces energy consumption, conforms to the concept of green development, and at the same time improves the essential oil yield of star anise. The GC-MS analysis results show that the composition of the main active ingredients in star anise essential oil remains basically unchanged, and the content of the active ingredient anethole is as high as 84.12%. Description of the Drawings

[0067] In order to more clearly illustrate the technical solutions of the embodiments of this application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of this application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative work, other relevant drawings can also be obtained based on these drawings.

[0068] Figure 1 Schematic diagram of the extraction device of this application (Note: 1 represents a round-bottom flask; 2 represents an air condenser; 3 represents a distillation head; 4 represents a condenser; 5 represents a receiving tube; 6 represents a receiving bottle; 7 represents a polymer membrane; 8 represents filter paper; 9 represents a thermometer);

[0069] Figure 2 Schematic diagram of the traditional extraction device of Comparative Example 1 (Note: A represents the material loading device; B represents a burette; C represents a glass conduit; D represents a distillation flask; E represents a distillation head; F represents a condenser);

[0070] Figure 3 Photo of the extraction device of this application

[0071] Figure 4 Photograph of the traditional extraction device for Comparative Example 1. Specific embodiments

[0072] The present application will be further described below in conjunction with specific embodiments. The following descriptions are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed in the following preferred embodiments, it is not intended to limit the present application. Any person skilled in the relevant art can make some changes or modifications within the scope of the technical solutions of the present application by using the disclosed technical content, and these changes or modifications are equivalent to equivalent embodiments and all fall within the scope of the technical solutions.

[0073] Unless otherwise specified, the raw materials in the embodiments of the present application are all purchased through commercial channels and used directly without any special treatment.

[0074] Unless otherwise specified, the analysis methods in the embodiments adopt the conventional settings and conventional analysis methods of the instruments or equipment.

[0075] The reagents and materials used in the present application include:

[0076] Ethyl acetate, sodium chloride, and anhydrous sodium sulfate of analytical grade (Shanghai Macklin Biochemical Co., Ltd.); two polytetrafluoroethylene (PTFE) hydrophobic membranes (diameter 50 mm, pore sizes 0.10 μm and 0.45 μm respectively) and one polyvinylidene fluoride (PVDF) hydrophobic membrane (diameter 50 mm, pore size 0.45 μm) (Haining Deli New Materials Technology Co., Ltd.); filter paper (pore size 80 μm) (Xi'an Minghuang Filter Materials Co., Ltd.); distilled water (Watsons Group); star anise (Wuhan Tianxianghui Condiment Co., Ltd.).

[0077] The instruments and characterization methods used in the present application:

[0078] 500 mL KDM electric heating mantle with a power of 250 W (Shandong Juancheng Hualu Electric Heating Instruments Co., Ltd.), round-bottom flask, air condenser, thermometer, distillation head, straight condenser, receiving tube (Tianjin Tianke Glass Instruments Manufacturing Co., Ltd.), iron stand.

[0079] GC-MS instrument (Agilent 5973) chromatographic conditions:

[0080] Injection port temperature: 220 °C

[0081] Injection volume: 1 μL

[0082] Splitless

[0083] Carrier gas: High-purity nitrogen (99.999%)

[0084] Column flow rate: 1 mL / min

[0085] Chromatographic column: DB5 fused silica capillary column, 30 m × 0.25 mm × 0.25 μm

[0086] Programmed temperature rise: Column temperature 40°C, hold for 1 min; increase to 200°C at a rate of 10°C / min, hold for 3 min

[0087] Mass spectrometry conditions: EI ion source

[0088] Electron energy: 70 eV

[0089] Emission current: 100 μA

[0090] Interface temperature: 210°C

[0091] Ion source temperature: 210°C

[0092] Flow scanning range: 50 - 350 m / z

[0093] Solvent delay: 4.0 min

[0094] Example 1

[0095] Method for extracting star anise essential oil using the extraction device of the present application:

[0096] (1) Grind 15 g of star anise to a particle size of 120 μm using a ball mill pulverizer, and set aside;

[0097] (2) Use a 250 ml round-bottom flask as a steam generation device, add distilled water accounting for 3 / 4 of the volume of the flask and 3 zeolites, and install an air condenser at the bottle mouth;

[0098] (3) Fill a filter paper at the bottom of the air condenser, place 15 g of ground star anise powder, and load a single layer of 0.45 μm polytetrafluoroethylene (PTFE) hydrophobic membrane at the top. Then install a distillation head, condenser, receiver tube, receiver flask, and thermometer as shown. The picture of the installed device is as shown; Figure 1 shown Figure 3 as shown;

[0099] (4) Pass in condensed water, enter from the lower inlet of the condenser and flow out from the upper outlet. Turn on the heating device, control the thermometer temperature at 95°C, and observe the phenomenon. After heating for 10 min, observe that an oily liquid flows into the receiver flask. Adjust the voltage of the heating mantle to control the distillate flow rate at 1 drop every 4 s. After maintaining for 90 min, when the distillate is clear and transparent, the flow rate decreases, and there are no more oil droplets containing organic substances, it reaches the distillation end point. Turn off the heat source, stop passing in condensed water after the device cools down, and disassemble the device;

[0100] (5) After the fraction to be distilled has cooled naturally to room temperature, remove the receiving flask, add salt to saturate it (add 3.2 g for every 10 mL), stir well, let it stand, and obtain a mixed solution;

[0101] (6) Pour the mixed solution into a pear-shaped separatory funnel, without pouring in the solid, add 8 mL of ethyl acetate for extraction, repeat the extraction operation 3 times, discard the aqueous layer, and combine the ester layers. Add an appropriate amount of anhydrous sodium sulfate to dry in the conical flask where the ethyl acetate is combined. Transfer the ester layer to a dry 50 mL round-bottom flask that has been pre-added with boiling chips and weighed for the total weight, distill, distill out the ethyl acetate, collect the residue, and thus obtain star anise essential oil, and weigh it.

[0102] Repeat the above steps, conduct a total of 6 experiments, and record the experimental data respectively.

[0103] Example 2

[0104] Method for extracting star anise essential oil using the extraction device of the present application:

[0105] (1) Grind 15 g of star anise to a particle size of 150 μm using a ball mill pulverizer, and set aside;

[0106] (2) Use a 250 ml round-bottom flask as a steam generation device, add distilled water accounting for 3 / 4 of the volume of the flask and 2 boiling chips into the flask, and install an air condenser at the bottle mouth;

[0107] (3) Fill filter paper at the bottom of the air condenser, place 15 g of pulverized star anise powder, and load a single layer of 0.45 μm polytetrafluoroethylene (PTFE) hydrophobic membrane at the top. Then install a distillation head, a condenser, a receiving tube, a receiving flask, and a thermometer as shown in Figure 1 The picture of the completed installation is as shown in Figure 3 shown;

[0108] (4) Pass in cooling water, enter from the lower opening of the condenser and flow out from the upper opening, turn on the heating device, control the thermometer temperature at 94 °C, and observe the phenomenon. After heating for about 10 min, observe that an oily liquid flows into the receiving flask, adjust the voltage of the heating mantle, and control the distillate flow rate at 1 drop every 3 s. Keep it for about 90 min. When the distillate is clear and transparent, the flow rate decreases, and there are no more oil droplets containing organic substances, it reaches the distillation end point. Turn off the heat source, stop passing in cooling water after the device has cooled, and disassemble the device;

[0109] (5) After the fraction to be distilled has cooled naturally to room temperature, remove the receiving flask, add salt to saturate it (add 3 g for every 10 mL), stir well, let it stand, and obtain a mixed solution;

[0110] (6) Pour the mixture into a pear-shaped separatory funnel, without pouring in the solids. Add 8 mL of ethyl acetate for extraction, and repeat the extraction operation 3 times. Discard the aqueous layer and combine the ester layers. Add an appropriate amount of anhydrous sodium sulfate to the conical flask containing the combined ethyl acetate for drying. Transfer the ester layer to a dry 50 mL round-bottom flask that has been pre-added with boiling chips and weighed for the total weight. Distill to evaporate the ethyl acetate, collect the residue, and obtain star anise essential oil, then weigh it.

[0111] Repeat the above steps, and conduct a total of 6 experiments, recording the experimental data respectively.

[0112] Example 3

[0113] Method for extracting star anise essential oil using the extraction device of the present application:

[0114] (1) Grind 15 g of star anise to a particle size of 100 μm using a ball mill pulverizer, and set aside.

[0115] (2) Use a 250 ml round-bottom flask as the steam generation device. Add distilled water accounting for 2 / 3 of the volume of the flask and 4 boiling chips into the flask, and install an air condenser at the bottle mouth.

[0116] (3) Fill filter paper at the bottom of the air condenser, place 15 g of pulverized star anise powder, and load a single layer of 0.45 μm polytetrafluoroethylene (PTFE) hydrophobic membrane on the top. Then install a distillation head, condenser, receiving tube, receiving bottle, and thermometer as shown in Figure 1 shown. The picture of the installed device is as shown in Figure 3 shown;

[0117] (4) Pass in cooling water, enter from the lower inlet of the condenser and flow out from the upper outlet. Turn on the heating device, control the thermometer temperature at 96 °C, and observe the phenomenon. Heat for about 10 min, observe that an oily liquid flows into the receiving bottle, adjust the voltage of the heating mantle, and control the distillate flow rate at 1 drop every 5 s. Keep heating for about 90 min. When the distillate is clear and transparent, the flow rate decreases, and there are no more oil droplets containing organic substances, it reaches the distillation end point. Turn off the heat source, stop passing in the cooling water after the device cools down, and disassemble the device;

[0118] (5) After the distillate naturally cools to room temperature, remove the receiving bottle, add table salt to saturate it (add 3.5 g for every 10 mL), stir well, and let it stand to obtain a mixture;

[0119] (6) Pour the mixture into a pear-shaped separatory funnel, without pouring in the solids. Add 8 mL of ethyl acetate for extraction, and repeat the extraction operation 3 times. Discard the aqueous layer and combine the ester layers. Add an appropriate amount of anhydrous sodium sulfate to the conical flask containing the combined ethyl acetate for drying. Transfer the ester layer to a dry 50 mL round-bottom flask that has been pre-added with boiling chips and weighed for the total weight. Distill to evaporate the ethyl acetate, collect the residue, and obtain star anise essential oil, then weigh it.

[0120] Repeat the above steps for a total of 6 experiments, and record the experimental data separately.

[0121] Comparative Example 1

[0122] Keep other operating conditions unchanged, and use a traditional extraction device (such as Figure 2 and Figure 4 shown) to repeat the steps of Example 1 for a total of 6 experiments, and record the experimental data separately.

[0123] Comparative Example 2

[0124] Keep other operating conditions unchanged, change the polytetrafluoroethylene hydrophobic membrane with a pore size of 0.45 μm to a polytetrafluoroethylene hydrophobic membrane with a pore size of 0.10 μm, and repeat the steps of Example 1 for a total of 6 experiments, and record the experimental data separately.

[0125] Comparative Example 3

[0126] Keep other operating conditions unchanged, change the polytetrafluoroethylene hydrophobic membrane with a pore size of 0.45 μm to a polyvinylidene fluoride (PVDF) hydrophobic membrane with a pore size of 0.45 μm, and repeat the steps of Example 1 for a total of 6 experiments, and record the experimental data separately.

[0127] Experimental Example 1

[0128] Taking Examples 1 to 3 and Comparative Examples 1 to 3 as examples, respectively, count the distillation time and the electric energy consumption per single experiment for each group, calculate the essential oil yield of each group (essential oil yield = essential oil mass / star anise mass × 100%), and take the average value. The results are shown in Table 1.

[0129] Table 1 Statistical results of experimental results for each group

[0130]

[0131]

[0132] As can be seen from Table 1, compared with Comparative Examples 1-3, the distillation time and the overall experimental duration of Examples 1-3 of the present application are both shortened, and the energy consumption is lower, and the essential oil yield is also higher, with Example 1 being the most significant. Taking Comparative Example 1 as an example, the traditional extraction device it uses needs to almost dry the water in the steam generating device, which takes about 2 hours to complete, and the extraction amount is not guaranteed. While the present application only takes about 1.5 hours to complete the distillation extraction. At the same time, the shortening of the experimental duration is accompanied by a reduction in energy consumption. It is calculated that the electric energy consumption per single experiment is reduced from 0.5 kw·h to 0.375 kw·h, a 25% reduction compared to the same period. It can be seen that only by adopting the extraction device and extraction method of the present application can the technical effects of the present application be achieved. Adopting the traditional extraction device or changing the type and particle size of the polymer membrane cannot achieve the technical effects of the present application.

[0133] Experimental Example 2

[0134] Collect all the products of the 6 experiments in Example 1 and all the products of the 6 experiments in Comparative Example 1, and use a GC-MS instrument to detect the components and contents of the star anise essential oil products in Example 1 and Comparative Example 1 respectively, and analyze the obtained data. The results are shown in Table 2.

[0135] Table 2 Analysis of the component types and contents of the products in Example 1 and Comparative Example 1

[0136]

[0137]

[0138] As can be seen from Table 2, compared with Comparative Example 1, the composition of the active ingredients in the essential oil product of the present application remains basically unchanged, but the content of the main active ingredient anethole has increased significantly, up to 84.12%. It can be seen that by adopting the extraction device and extraction method of the present application, the dissolution of the active ingredients in star anise essential oil can be effectively promoted.

[0139] To sum up, the extraction device for star anise essential oil provided by the present application changes the star anise packing device to an air condenser to form partial reflux, and a hydrophobic polymer membrane is set at the steam outlet, and its selective permeability is used to efficiently obtain star anise oil. The traditional extraction device is optimized, the simple pressurization of the experimental device is realized, the experimental steam transmission path is shortened, and at the same time the essential oil yield is increased. The device of the present application has a simple structure, high steam utilization rate, can weaken the emulsification phenomenon, the extraction method used not only saves the extraction time, but also reduces the energy consumption, conforms to the concept of green development, and at the same time improves the essential oil yield of star anise. The GC-MS analysis results show that the composition of the main active ingredients in star anise essential oil remains basically unchanged, and the content of the active ingredient anethole is as high as 84.12%.

[0140] The above are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the relevant art can make some changes or modifications within the scope of the technical solution of the present application by using the disclosed technical content, which are equivalent to equivalent embodiments and all fall within the scope of the technical solution.

Claims

1. An extraction device for star anise essential oil, characterized in that, It includes a round-bottom flask (1), an air condenser (2), a distillation head (3), a condenser (4), a receiving tube (5), and a receiving flask (6); The mouth of the round-bottom flask (1) is connected to the bottom of the air condenser (2); The top of the air condenser (2) is connected to the bottom tube of the distillation head (3); The side tube of the distillation head (3) is connected to the top of the condenser (4); The bottom of the condenser (4) is connected to the top of the receiving tube (5); Insert the tail of the receiving tube (5) into the receiving flask (6); Load a polymer membrane (7) at the top of the air condenser (2); Load a filter paper (8) at the bottom of the air condenser (2); Insert a thermometer (9) into the top of the distillation head (3); The polymer membrane (7) is a single-layer membrane; The polymer membrane (7) is a polytetrafluoroethylene hydrophobic membrane; The pore size of the polytetrafluoroethylene hydrophobic membrane is 0.4 - 0.5 μm.

2. A method for extracting star anise essential oil, characterized in that, It is carried out using the extraction device described in claim 1, including the following steps: (1) Crush star anise to obtain star anise powder; (2) Add distilled water and zeolite into the round-bottom flask, and install an air condenser at the mouth of the flask; (3) Fill a filter paper at the bottom of the air condenser, place the star anise powder on the filter paper, and then load a polymer membrane at the top of the air condenser; (4) Install the distillation head, condenser, receiving tube, and receiving flask in sequence, and insert a thermometer into the top of the distillation head; (5) Pass in cooling water, enter from the lower opening of the condenser and flow out from the upper opening, heat the round-bottom flask, start distillation, and stop when the distillate is clear and transparent, the flow rate decreases, and there are no more oil droplets of organic substances, reaching the distillation end point. Turn off the heat source and stop passing in cooling water after the device cools down; (6) After the distillate cools to room temperature, remove the receiving flask, add table salt and stir well, let it stand to obtain a mixed solution; (7) Pour the mixed solution into a pear-shaped separating funnel, add ethyl acetate for extraction, repeat the extraction operation 2 - 4 times, discard the water layer, combine the ester layers, carry out drying and distillation in sequence, distill out the ethyl acetate, and collect the residue to obtain star anise essential oil; In step (2), the added volume of the distilled water is 2 / 3 - 3 / 4 of the volume of the round-bottom flask; The dosage of the zeolite is 2 - 4 grains; In step (3), the pore size of the filter paper is smaller than the particle size of the star anise powder; The polymer membrane is a single-layer membrane; The polymer membrane is a polytetrafluoroethylene hydrophobic membrane; The pore size of the polytetrafluoroethylene hydrophobic membrane is 0.4 - 0.5 μm; In step (5), during the distillation process, control the thermometer temperature at 94 - 96 °C; When an oily liquid flows into the receiving flask, adjust the heating voltage to control the flow rate of the distillate at 3 - 5 s / drop.

3. The extraction method of star anise essential oil according to claim 2, characterized in that, In step (1), the particle size of the star anise powder is 100 - 150 μm; The dosage of the star anise powder is 10 - 30 g.

4. The extraction method of star anise essential oil according to claim 2, wherein, In step (3), the pore size of the polytetrafluoroethylene hydrophobic membrane is 0.45 μm.

5. The extraction method of star anise essential oil according to claim 2, characterized in that, In step (6), the dosage ratio of the table salt to the distillate in the receiving flask is 3 - 3.5 g:10 mL; The standing time is 10 - 20 min.

6. The extraction method of star anise essential oil according to claim 2, characterized in that, In step (7), the amount of ethyl acetate used is 20-40% of the volume of the mixed solution; The extraction time is 10-20 min / time.

7. The extraction method of star anise essential oil according to claim 2, characterized in that, In step (7), the drying is carried out using anhydrous sodium sulfate; The amount of anhydrous sodium sulfate used is 15-20% of the mass of the combined ester layer.

8. The extraction method of star anise essential oil according to claim 2, characterized in that, In step (7), the distillation temperature is 70-90 °C; The distillation time is 1-2 h.

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