Process and device for extracting flavonoids from a lithocarpus polystachyus plant sample

Abstract

The application discloses a process and device for extracting flavonoids from Litsea chenii plant samples, and belongs to the technical field of plant active ingredient extraction. The method comprises the following steps of raw material pretreatment, ultrasonic-microwave synergistic extraction, macroporous resin adsorption purification, and refined crystallization. A self-designed ultrasonic-microwave synergistic extraction tank is used as the core device, and a microwave generator, an ultrasonic transducer, a stirring device and a heating jacket system are integrated in the tank. The application combines the ultrasonic-microwave synergistic extraction technology with macroporous resin adsorption, improves the extraction rate of flavonoids, shortens the extraction time, and has high purity of the extracted flavonoids, with a yield of 3.5-4.2% and a purity of more than 95%. The process is simple, efficient and environmentally friendly, is suitable for industrial production, and provides technical support for the development and utilization of Litsea chenii resources.

Description

Technical Field

[0001] This invention relates to a process and apparatus for extracting flavonoids from Litsea cubeba plant samples, belonging to the field of plant active ingredient extraction technology. Background Technology

[0002] Litsea cubeba, also known as Litsea cubeba or false chestnut, is an evergreen tree belonging to the genus Litsea in the family Fagaceae. It is mainly distributed in southern China, including Guangxi, Guangdong, Fujian, Jiangxi, and Hunan, as well as northern Vietnam. The tree can reach a height of 15-20 meters. Its leaves are leathery, elliptical or oblong, with a glossy dark green upper surface and a pale green underside. This plant is used in traditional Chinese medicine to treat indigestion, diarrhea, and dysentery, and has high medicinal value.

[0003] Modern pharmacological studies have shown that Litsea cubeba plants are rich in flavonoids, mainly including dihydrochalcone flavonoids such as trifolin and phlorizin, as well as flavonoid aglycones such as phloretin. These flavonoids possess significant biological activities, including antioxidant, anti-inflammatory, hypoglycemic, hypolipidemic, and antitumor effects. Of particular note is that trifolin and phlorizin can be hydrolyzed under acidic or enzymatic conditions to produce phloretin. A nucleoside-glycoside structural relationship exists among the three, with phloretin being the aglycone of both phlorizin and trifolin, exhibiting even stronger biological activity.

[0004] Flavonoids have broad application prospects in food, medicine, cosmetics and other fields. However, there is relatively little research on the extraction process of flavonoids from Litsea cubeba. Existing extraction methods mainly have the following problems: First, traditional solvent extraction methods are time-consuming and have low extraction efficiency, with flavonoid yields of only 1.5-2.0%; second, they use large amounts of organic solvents, which are costly and environmentally unfriendly; third, the extract contains high levels of impurities, making purification processes complex and flavonoid purity difficult to reach above 95%; and fourth, there is a lack of specially designed extraction equipment, making it difficult to achieve continuous industrial production.

[0005] Ultrasonic-assisted extraction (UART) is a highly efficient method for extracting active plant components. Its principle involves using the cavitation, mechanical, and thermal effects of ultrasound to disrupt plant cell walls and promote the dissolution of active ingredients. Microwave-assisted extraction utilizes the thermal and non-thermal effects of microwaves to rapidly heat the material, promoting the release of intracellular substances. Combining ultrasound and microwaves can produce a synergistic effect, further improving extraction efficiency. Macroporous resin adsorption technology is an effective separation and purification method. Through an adsorption-desorption process, it can efficiently enrich target compounds and remove impurities.

[0006] To address the aforementioned technical challenges, there are currently no reports, either domestically or internationally, of systematic processes and dedicated equipment for the efficient extraction of flavonoids from Litsea cubeba plant samples. Therefore, developing an efficient, environmentally friendly, and industrially viable extraction process and apparatus for Litsea cubeba flavonoids is of significant theoretical and practical value for fully utilizing Litsea cubeba resources and developing high-value-added flavonoid products. Summary of the Invention

[0007] To address the problems existing in the prior art, the purpose of this invention is to provide an efficient process and apparatus for extracting flavonoids from Litsea cubeba plant samples. This process has high extraction efficiency, high product purity, simple operation, and is environmentally friendly and energy-saving, making it suitable for industrial production.

[0008] This invention is achieved through the following scheme: a process for extracting flavonoids from Litsea cubeba plant samples, comprising the following steps:

[0009] S1: Raw material pretreatment: Select leaves or branches of Litsea cubeba as raw materials, wash them and dry them at 50-60℃ until the moisture content is less than 10%, then crush them to 20-40 mesh to obtain Litsea cubeba coarse powder;

[0010] S2: Ultrasonic-microwave synergistic extraction: Mix the crude powder of Litsea cubeba with the extraction solvent at a material-to-liquid ratio of 1:8-1:15 (g / mL). The extraction solvent is an ethanol aqueous solution with a volume concentration of 50-70%. Extract for 40-80 minutes at an ultrasonic power of 300-500W, a frequency of 40-60kHz, a microwave power of 200-400W, and a temperature of 50-70℃. Filter to obtain the extract.

[0011] S3: Extraction concentration: The extract obtained in step S2 is concentrated under reduced pressure at 70-85 kPa vacuum and 50-60℃ to 1 / 3-1 / 5 of its original volume to obtain a concentrated solution.

[0012] S4: Macroporous resin adsorption purification: The concentrated solution obtained in step S3 is loaded onto a macroporous resin adsorption column. The macroporous resin type is AB-8 or D101. The loading flow rate is 1-3 BV / h. Impurities are removed by elution with 2-4 column volumes of water, and then eluted with 3-5 column volumes of 70-80% ethanol. The eluent is collected to obtain the total flavonoid eluent.

[0013] S5: Refining and crystallization: Concentrate the total flavonoid eluent obtained in step S4 under reduced pressure to 1 / 4-1 / 6 of the original volume, cool to 5-15℃, let stand for 12-24 hours, precipitate crystals, filter, wash the crystals with a small amount of cold ethanol, and dry under vacuum at 40-50℃ for 4-6 hours to obtain crude flavonoids.

[0014] S6: Recrystallization: Dissolve the crude flavonoid product obtained in step S5 in 70% ethanol at 70-80℃, decolorize with activated carbon, filter while hot, cool to 5-15℃ to precipitate crystals, filter, and vacuum dry to obtain a high-purity flavonoid product.

[0015] Furthermore, in step S2, the technical parameters for ultrasonic-microwave synergistic assisted extraction are as follows: ultrasonic power is 400W, frequency is 50kHz, microwave power is 300W, extraction solvent is 60% ethanol aqueous solution, material-liquid ratio is 1:10 (g / mL), extraction temperature is 60℃, and extraction time is 60 minutes.

[0016] Furthermore, in step S2, the extraction residue is extracted 1-2 times, and the extracts are combined.

[0017] Furthermore, in step S3, the technical parameters for vacuum concentration are: vacuum degree of 75-80 kPa, concentration temperature of 55℃, and concentration to 1 / 4 of the original volume.

[0018] Furthermore, in step S4, the macroporous resin needs to be soaked in 95% ethanol for 12-24 hours before use, and then washed with distilled water until there is no alcohol odor before being packed into the column for use.

[0019] Furthermore, in step S5, the temperature for refining and crystallizing is 10°C, and the standing time is 18 hours.

[0020] Furthermore, in step S6, the amount of activated carbon used is 2-5% of the crude flavonoid mass, and the decolorization time is 20-30 minutes.

[0021] A de-impacting ultrasonic-microwave synergistic extraction vessel for implementing the above method includes:

[0022] The tank body is made of stainless steel and has a sandwich structure;

[0023] A heating jacket is installed on the outer wall of the tank and is used to introduce hot water or steam for heating;

[0024] Microwave generators are evenly distributed on the side wall of the tank to generate microwave-assisted extraction.

[0025] An ultrasonic transducer is installed at the bottom and side wall of the tank to generate ultrasonic-assisted extraction.

[0026] A mixing device, including a mixing motor and mixing blades, is located at the center of the tank and is used to mix materials;

[0027] The feed inlet, located at the top of the tank, is used to add raw materials and solvents;

[0028] The discharge port is located at the bottom of the tank and is used to discharge the extract.

[0029] Temperature and pressure sensors are used to monitor the temperature and pressure inside the tank, respectively.

[0030] The microwave generator and ultrasonic transducer are power-adjustable through a control system, enabling ultrasonic-microwave synergistic extraction.

[0031] Furthermore, the tank has a volume of 50-200L, and the inner wall of the tank is coated with an anti-corrosion layer.

[0032] Furthermore, the microwave generator has an adjustable power of 200-400W; the ultrasonic transducer has an adjustable power of 300-500W and a frequency of 40-60kHz.

[0033] Furthermore, the microwave generators are evenly distributed in a ring on the side wall of the tank, with a quantity of 4-8; the ultrasonic transducers are arranged in an array on the bottom and side wall of the tank, with a quantity of 6-12.

[0034] Furthermore, the stirring blades of the stirring device are of an anchor or paddle type, and the rotation speed is adjustable, ranging from 50 to 200 rpm.

[0035] Furthermore, the heating temperature of the heating interlayer can be controlled within the range of 50-100℃, and closed-loop control is achieved through a temperature sensor.

[0036] The beneficial effects of this invention are as follows:

[0037] 1. This invention employs ultrasonic-microwave synergistic extraction technology. The cavitation effect of ultrasound and the thermal effect of microwave produce a synergistic effect, effectively destroying plant cell walls, promoting the dissolution of flavonoids, and shortening the extraction time to 40-80 minutes, which is more than 50% shorter than the traditional immersion method. The flavonoid yield can reach 3.5-4.2%, which is 75-110% higher than the traditional method.

[0038] 2. This invention uses macroporous resin adsorption purification combined with recrystallization technology to effectively remove impurities such as sugars, proteins, and pigments. The purity of the final product can reach more than 95%, which meets food and pharmaceutical grade standards.

[0039] 3. This invention uses a 50-70% ethanol aqueous solution as the extraction solvent, which reduces the amount of organic solvent used by 30-40% compared with traditional methods. The extraction temperature is controlled at 50-70℃, resulting in low energy consumption and compliance with the principles of green chemistry.

[0040] 4. The process flow of this invention is clear, the parameter control is precise, it is easy to operate and manage, and it is suitable for industrial continuous production.

[0041] 5. The ultrasonic-microwave synergistic extraction tank provided by the present invention integrates a microwave generator and an ultrasonic transducer in the same tank body, realizing ultrasonic-microwave synergistic extraction. The equipment is compact, highly automated, and improves production efficiency.

[0042] 6. This invention can utilize the leaves and branches of Litsea cubeba as raw materials, providing technical support for the comprehensive development and utilization of Litsea cubeba resources, and has good economic and social benefits. Attached Figure Description

[0043] Figure 1 This is a front view (cross-sectional view) of the ultrasonic-microwave synergistic extraction vessel of the present invention.

[0044] Figure 2 This is a top view of the ultrasonic-microwave synergistic extraction vessel of the present invention.

[0045] In the diagram: 1-Inlet, 2-Pressure sensor, 3-Temperature sensor, 4-Heating jacket, 5-Outlet, 6-Microwave generator, 7-Tank body, 8-Ultrasonic transducer, 9-Outlet pipe, 10-Stirring motor, 11-Stirring shaft. Detailed Implementation

[0046] The following is combined with Figure 1-2 The present invention will be further described, but the scope of protection of the present invention is not limited to the contents described herein.

[0047] Example 1

[0048] A method for extracting flavonoids from a Litsea cubeba plant sample includes the following steps:

[0049] S1: Raw material pretreatment: Collect 5 kg of fresh Litsea cubeba leaves, wash them with clean water, drain them, dry them in an oven at 55℃ until the moisture content is 8%, and then grind them to 30 mesh using a pulverizer to obtain 4.2 kg of Litsea cubeba coarse powder.

[0050] S2: Ultrasonic-Microwave Co-assisted Extraction: 4.2 kg of Litsea cubeba coarse powder was added to a de-impregnated ultrasonic-microwave co-extraction tank. 42 L of 60% ethanol aqueous solution was added at a material-to-liquid ratio of 1:10 (g / mL). The ultrasonic transducer was started, with the ultrasonic power set to 400 W and the frequency 50 kHz. Simultaneously, the microwave generator was started, with the microwave power set to 300 W. The mixture was heated to 60°C through the heating jacket and extracted for 60 minutes. After extraction, the extract was discharged from the outlet, filtered, and the filtrate was collected. The residue was extracted once more, and the two filtrates were combined to obtain approximately 80 L of extract.

[0051] S3: Extraction concentration: Transfer 80L of extract to a vacuum concentration apparatus and concentrate it to 20L under vacuum conditions of 78kPa and 55℃ to obtain concentrated extract.

[0052] S4: Macroporous resin adsorption purification: Pretreated AB-8 macroporous resin was packed into a stainless steel adsorption column (10cm in diameter, 60cm in height, self-made). 20L of concentrate was loaded onto the macroporous resin adsorption column at a flow rate of 2BV / h. After loading, 3 column volumes of distilled water were used to remove impurities such as sugars, and then 4 column volumes of 75% ethanol were used to elute. About 20L of eluent was collected to obtain the total flavonoid eluent.

[0053] S5: Refining and Crystallization: The 20L total flavonoid eluent was concentrated to 4L using a vacuum concentration device, transferred to a crystallizer equipped with a temperature control system, and the temperature control system was activated. The mixture was cooled to 10℃ and allowed to stand for 18 hours, resulting in the precipitation of a large amount of yellow crystals. The crystals were filtered, washed with a small amount of cold ethanol, and dried under vacuum at 45℃ for 5 hours in a vacuum drying oven to obtain 160g of crude flavonoids.

[0054] S6: Recrystallization: Dissolve 160g of crude flavonoids in 1.6L of 70% ethanol at 75℃, add 4.8g of activated carbon, decolorize for 25 minutes, filter while hot, cool the filtrate to 10℃ to precipitate crystals, filter, and vacuum dry to obtain 145g of high-purity flavonoids product.

[0055] HPLC analysis showed that the purity of flavonoids was 96.5%, and the yield was 3.8% (based on dried raw materials).

[0056] Example 2

[0057] A method for extracting flavonoids from a Litsea cubeba plant sample includes the following steps:

[0058] S1: Raw material pretreatment: Collect 10kg of Litsea cubeba branches, wash them, dry them at 50℃ until the moisture content is 9%, and crush them to 20 mesh to obtain 8.5kg of Litsea cubeba coarse powder.

[0059] S2: Ultrasonic-Microwave Co-assisted Extraction: 8.5 kg of Litsea cubeba coarse powder was mixed with 50% ethanol aqueous solution at a material-to-liquid ratio of 1:12 (g / mL), added to an extraction tank, and extracted for 80 minutes at an ultrasonic power of 300 W and a frequency of 40 kHz, a microwave power of 200 W, and a temperature of 50 °C. The filtrate was collected after filtration. The residue was extracted twice more, and the filtrates were combined to obtain approximately 290 L of extract.

[0060] S3: Extract concentration: The extract is concentrated to 58L under reduced pressure at a vacuum of 75kPa and a temperature of 50℃.

[0061] S4: Macroporous resin adsorption purification: D101 macroporous resin was used, the loading flow rate was 1 BV / h, the column volume was washed with water for 3 columns, and the column volume was eluted with 70% ethanol for 5 columns. The eluent was collected.

[0062] S5: Refining and crystallization: The eluent was concentrated under reduced pressure to 1 / 5 of its original volume, cooled to 5°C, allowed to stand for 24 hours, filtered, washed with cold ethanol, and dried under vacuum at 40°C for 6 hours to obtain 280g of crude flavonoids.

[0063] S6: Recrystallization: The crude flavonoid product was dissolved in 70% ethanol at 80℃, decolorized with activated carbon (2%), filtered while hot, cooled to crystallize, filtered again, and vacuum dried to obtain 252g of high-purity flavonoid product.

[0064] HPLC analysis showed that the purity of flavonoids was 95.2%, and the yield was 3.5% (based on dried raw materials).

[0065] Example 3

[0066] A method for extracting flavonoids from a Litsea cubeba plant sample includes the following steps:

[0067] S1: Raw material pretreatment: Collect 15kg of a mixture of leaves and branches of Litsea cubeba, wash and dry it to a moisture content of 10%, and crush it to 40 mesh to obtain 12kg of coarse powder.

[0068] S2: Ultrasonic-microwave synergistic extraction: material-liquid ratio 1:8 (g / mL), 70% ethanol aqueous solution, ultrasonic power 500W, frequency 60kHz, microwave power 400W, temperature 70℃, extraction for 40 minutes, repeated extraction once, and the filtrates were combined.

[0069] S3: Extract concentration: Vacuum degree 85kPa, temperature 60℃, concentrate to 1 / 3 of the original volume.

[0070] S4: Macroporous resin adsorption purification: AB-8 resin, loading flow rate 3 BV / h, washing with water for 2 column volumes, eluting with 80% ethanol for 3 column volumes.

[0071] S5: Refining and crystallization: Concentrate to 1 / 6 of the original volume, cool to 15°C, stand for 12 hours, filter, and vacuum dry to obtain 480g of crude flavonoids.

[0072] S6: Recrystallization: Dissolved at 70℃ in 70% ethanol, decolorized with activated carbon (5%), cooled and crystallized to obtain 432g of high-purity flavonoid product.

[0073] HPLC analysis showed that the purity of flavonoids was 97.8%, and the yield was 4.2% (based on dried raw materials).

[0074] The table below shows the core yield data for Examples 1-3.

[0075] Example raw material ethanol concentration Extraction temperature Extraction time Flavonoid yield Flavonoid purity Example 1 leaf 60% 60℃ 60 minutes 3.8% 96.5% Example 2 branch 50% 50℃ 80 minutes 3.5% 95.2% Example 3 Leaves + branches 70% 70℃ 40 minutes 4.2% 97.8%

[0076] Example 4: De-imping ultrasonic-microwave synergistic extraction vessel

[0077] like Figure 1 and Figure 2 As shown, a de-impacting ultrasonic-microwave synergistic extraction vessel for extracting flavonoids from Litsea cubeba plant samples is the core self-designed device of this invention, comprising:

[0078] Tank 7 is made of 316L stainless steel, with a volume of 100L. It has a double-layered structure, and the inner wall of the tank is coated with a polytetrafluoroethylene (PTFE) anti-corrosion layer to prevent acid and alkali corrosion. The tank is cylindrical in shape, with an inner diameter of 400mm and a height of 800mm.

[0079] Heating jacket 4 is installed on the outer wall of the tank, with a thickness of 20mm. Hot water or steam is circulated inside the jacket for heating, which can control the extraction temperature between 50-100℃. The heating jacket is equipped with a water inlet and an outlet, and is connected to an external circulating heating system.

[0080] Microwave generator 6 is a magnetron-type microwave generator with a power of 300W and a frequency of 2450MHz, which is adjustable. Six microwave generators are evenly distributed in a ring on the side wall of the tank. Each microwave generator is connected to the inside of the tank via a waveguide to ensure uniform distribution of microwave energy. An external cooling system is provided for each microwave generator to prevent overheating.

[0081] The ultrasonic transducer (8 units) uses a piezoelectric ceramic transducer with a power of 400W and an adjustable frequency of 50kHz. The ultrasonic transducers are arranged in an array on the bottom and side walls of the tank, with 4 on the bottom and 4 on the side walls, for a total of 8. The ultrasonic transducers are fixed to the tank via flange connections, making direct contact with the tank's interior to ensure effective transmission of ultrasonic energy.

[0082] The mixing device includes a mixing motor 10 and a mixing shaft 11. The mixing motor is mounted at the center of the top of the tank, has a power of 1.5kW, and an adjustable speed ranging from 50-200rpm. The mixing shaft is made of stainless steel, has a diameter of 30mm, a length of 700mm, and runs through the center of the tank. Anchor-type mixing blades with a diameter of 350mm are installed at the bottom of the mixing shaft to ensure thorough mixing of materials. The mixing shaft is connected to the top cover of the tank via a mechanical seal to prevent leakage.

[0083] Inlet 1, located at the top of the tank, has a diameter of 100mm and is equipped with a quick-opening flange cover for easy addition of raw materials and solvents. The inlet is also equipped with a sight glass to observe the state of the materials inside the tank.

[0084] The discharge port 5, located at the bottom of the tank, has a diameter of 50 mm and is controlled by a ball valve for discharging the extract. The discharge port is connected to the discharge pipe 9, which leads to the filtration system.

[0085] Temperature sensor 3, a Pt100 platinum resistance temperature sensor, is installed on the upper side wall of the tank. It has a measurement range of 0-150℃ and an accuracy of ±0.5℃, and is used for real-time monitoring of the tank's internal temperature. The temperature sensor is connected to the control system to achieve closed-loop temperature control.

[0086] Pressure sensor 2, a piezoresistive pressure sensor, is installed on the top of the tank. It has a measurement range of 0-0.5MPa and an accuracy of ±0.01MPa. It is used to monitor the pressure inside the tank in real time to ensure safe operation.

[0087] The control system, using PLC control, can precisely control and adjust parameters such as microwave generator power, ultrasonic transducer power and frequency, stirring speed, and heating temperature. The control system features a human-machine interface that displays parameter values ​​in real time and includes an alarm function.

[0088] The process flow is as follows: Add the coarse powder of Litsea cubeba and the extraction solvent into the extraction tank through inlet 1, then close the inlet. Start the stirring motor 10; the stirring blades will begin to rotate, ensuring thorough mixing of the materials. Start the heating system, heating the tank to the set temperature (50-70℃) via the heating jacket 4. Temperature sensor 3 monitors the temperature in real time, and the control system implements closed-loop temperature control. Simultaneously, start the microwave generator 6 and the ultrasonic transducer 8. The microwave and ultrasonic waves work synergistically to break down plant cell walls and promote flavonoid dissolution. After a certain extraction time (40-80 minutes), stop the microwave and ultrasonic waves, stop heating, and open the discharge valve 5. The extract will be discharged from the discharge pipe 9 and proceed to subsequent filtration and purification processes.

[0089] The ultrasonic-microwave synergistic extraction vessel of this invention integrates a microwave generator and an ultrasonic transducer into the same vessel body, achieving ultrasonic-microwave synergistic extraction. The equipment is compact, highly automated, and significantly improves extraction efficiency. The device is rationally designed, easy to operate, and suitable for industrial applications.

[0090] Although the technical solutions of the present invention have been described and enumerated in detail, it should be understood that modifications to the above embodiments or the adoption of equivalent alternatives are obvious to those skilled in the art. Such modifications or improvements made without departing from the spirit of the present invention are all within the scope of protection claimed by the present invention.

Claims

1. A process for extracting flavonoids from Litsea cubeba plant samples. Includes the following steps: S1: Raw material pretreatment: Select leaves or branches of Litsea cubeba as raw materials, wash them, dry them at 50-60℃ until the moisture content is less than 10%, and pulverize them to 20-40 mesh to obtain Litsea cubeba coarse powder; S2: Ultrasonic-microwave assisted extraction: Mix Litsea cubeba coarse powder with extraction solvent at a material-liquid ratio of 1:8-1:15 (g / mL). The extraction solvent is an ethanol aqueous solution with a volume concentration of 50-70%. Extract at 50-70℃ for 40-80 minutes under ultrasonic power of 300-500W, frequency of 40-60kHz, microwave power of 200-400W, and ultrasonic temperature of 300-500W. Filter to obtain the extract; S3: Extraction concentration: The extract obtained in step S2 is concentrated under reduced pressure at 70-85 kPa vacuum and 50-60℃ to 1 / 3-1 / 5 of its original volume to obtain a concentrated solution. S4: Macroporous resin adsorption purification: The concentrated solution obtained in step S3 is loaded onto a macroporous resin adsorption column. The macroporous resin type is AB-8 or D101. The loading flow rate is 1-3 BV / h. Impurities are removed by elution with 2-4 column volumes of water, and then eluted with 3-5 column volumes of 70-80% ethanol. The eluent is collected to obtain the total flavonoid eluent. S5: Refining and crystallization: Concentrate the total flavonoid eluent obtained in step S4 under reduced pressure to 1 / 4-1 / 6 of its original volume, cool to 5-15℃, let stand for 12-24 hours to precipitate crystals, filter, wash the crystals with a small amount of cold ethanol, and dry under vacuum at 40-50℃ for 4-6 hours to obtain crude flavonoids; S6: Recrystallization: Dissolve the crude flavonoids obtained in step S5 in 70% ethanol at 70-80℃, decolorize with activated carbon, filter while hot, cool to 5-15℃ to precipitate crystals, filter, and dry under vacuum to obtain high-purity flavonoids product.

2. The process for extracting flavonoids from Litsea cubeba plant samples according to claim 1, characterized in that, In step S2, the technical parameters for ultrasonic-microwave assisted extraction are as follows: ultrasonic power is 400W, frequency is 50kHz, microwave power is 300W, extraction solvent is 60% ethanol aqueous solution, material-liquid ratio is 1:10 (g / mL), extraction temperature is 60℃, and extraction time is 60 minutes.

3. The process for extracting flavonoids from Litsea cubeba plant samples according to claim 1, characterized in that, In step S2, the extraction residue is extracted 1-2 times, and the extracts are combined.

4. The process for extracting flavonoids from Litsea cubeba plant samples according to claim 1, characterized in that, In step S3, the technical parameters for vacuum concentration are: vacuum degree of 75-80 kPa, concentration temperature of 55℃, and concentration to 1 / 4 of the original volume.

5. The process for extracting flavonoids from Litsea cubeba plant samples according to claim 1, characterized in that, In step S4, the macroporous resin needs to be soaked in 95% ethanol for 12-24 hours before use, and then washed with distilled water until there is no alcohol smell before being packed into the column for use.

6. The process for extracting flavonoids from Litsea cubeba plant samples according to claim 1, characterized in that, In step S5, the temperature for refining and crystallizing is 10°C, and the standing time is 18 hours.

7. The process for extracting flavonoids from Litsea cubeba plant samples according to claim 1, characterized in that, In step S6, the amount of activated carbon used is 2-5% of the crude flavonoid mass, and the decolorization time is 20-30 minutes.

8. An apparatus for carrying out the process of claim 1, characterized in that, include, The tank body (7) is made of stainless steel and has a sandwich structure; Heating jacket (4) is set on the outer wall of the tank and used to introduce hot water or steam for heating; Microwave generators (6) are evenly distributed on the side wall of the tank and are used to generate microwave-assisted extraction. An ultrasonic transducer (8) is installed at the bottom and side wall of the tank to generate ultrasonic-assisted extraction; A mixing device (10), including a mixing motor and mixing blades, is set in the center of the tank and is used to mix materials; The feed inlet (1) is located at the top of the tank and is used to add raw materials and solvents; The discharge port (5) is located at the bottom of the tank and is used to discharge the extract. Temperature sensor (3) and pressure sensor (2) are used to monitor the temperature and pressure inside the tank, respectively; The microwave generator (6) and ultrasonic transducer (8) are power adjustable through the control system to achieve ultrasonic-microwave collaborative extraction.

9. The apparatus according to claim 8, characterized in that, The tank (7) has a volume of 50-200L. The inner wall of the tank (7) is coated with an anti-corrosion layer. The stirring blades of the stirring device (10) are anchor or paddle type with adjustable speed, ranging from 50-200rpm. The heating temperature of the heating jacket (4) can be controlled within the range of 50-100℃, and closed-loop control is achieved through a temperature sensor.

10. The apparatus according to claim 8, characterized in that, The microwave generator (6) has a power of 200-400W and is adjustable; the ultrasonic transducer (8) has a power of 300-500W and a frequency of 40-60kHz and is adjustable; the microwave generator (6) is evenly distributed in a ring on the side wall of the tank, with a quantity of 4-8; the ultrasonic transducer (8) is distributed in an array on the bottom and side wall of the tank, with a quantity of 6-12.

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