A method for realizing high-efficiency extraction of plant raw materials by online adjustment of solvent ratio

Abstract

The application discloses a method for realizing high-efficiency extraction of plant raw materials by online adjustment of solvent proportion, and belongs to the technical field of production process control. A solvent recovery unit carries out online detection on the proportion of the recovered solvent after evaporation and condensation of the recovered solvent, and delivers the recovered solvent to a solvent preparation unit. The solvent preparation unit calculates the amount of new solvent to be added according to the detection result, controls the delivery of the new solvent from the solvent tank of the solvent preparation unit to the solvent preparation tank through a control unit, and mixes the new solvent. The prepared solvent is detected again to confirm the proportion, and then enters an extraction unit. The proportion of the solvent is detected in the middle section of the extraction unit, and new solvent is added from the solvent tank to the extraction unit according to the process requirement. A material cake detection unit detects the material cake of the extraction unit. The proportion of the extraction solvent is dynamically adjusted according to the residual situation of the effective components in the material cake, and then the control unit is used to adjust the proportion of the solvent through the solvent preparation unit. The above steps are repeated in continuous production.

Description

Technical Field

[0001] This invention belongs to the field of production process control technology, and in particular relates to a method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online. Background Technology

[0002] Plant extracts are active ingredients extracted from plants using physical or chemical methods, and are widely used in pharmaceuticals, health products, cosmetics, food and beverages, and other fields. With increasing health awareness and growing demand for natural products, the plant extract industry has experienced rapid development.

[0003] Plant extraction methods include solvent extraction, water extraction, supercritical fluid extraction, and enzymatic hydrolysis. Among these, solvent extraction is widely used due to its wide applicability, low cost, ease of scaling up, and continuous production. Using mixed solvents can typically improve extraction efficiency and selectivity, achieving high-efficiency extraction. Controlling the ratio of extraction solvents to achieve precise and efficient extraction is a challenge in the industry. Currently, most companies prepare a fixed ratio of mixed solvents by precise volume measurement before extraction begins. However, solvents are consumed to varying degrees during the extraction and recovery cycle, making it impossible to maintain a constant solvent ratio. Furthermore, the composition of plant extracts varies depending on the variety, origin, and year. Using a fixed solvent ratio will not achieve optimal extraction results; dynamic adjustments are necessary. Additionally, even after distillation recovery of the mixed solvent, complete separation is not possible, preventing reuse in subsequent extractions. Rational utilization of recovered solvents is both cost-effective and environmentally friendly. Reusing recovered solvents in the plant extraction process is the best application of recovered solvents. Summary of the Invention

[0004] The purpose of this invention is to provide a method for efficient extraction of plant raw materials by adjusting the solvent ratio online. By using different methods at different points to accurately detect and control the ratio of mixed solvents, efficient extraction of plant extracts is achieved, which not only improves the quality of the extracts but also increases the extraction yield and reduces environmental pollution.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for efficient extraction of plant raw materials by adjusting the solvent ratio online, using a high-efficiency extraction device, includes the following steps:

[0007] Step A: The solvent recovery unit evaporates and condenses the solvent recovered by the extraction unit, detects the proportion of condensed and recovered solvent online, and then sends it to the solvent preparation unit.

[0008] Step B: The solvent preparation unit calculates the amount of new solvent to be added based on the test results. The control unit controls the solvent tank of the solvent preparation unit to deliver the new solvent to the solvent preparation tank and mix it. The prepared solvent is tested again to confirm the ratio, and then enters the extraction unit.

[0009] Step C: Detect the solvent ratio in the middle of the extraction unit, and add new solvent from the solvent tank to the extraction unit according to process requirements;

[0010] Step D: The meal detection unit detects the meal from the extraction unit. The solvent ratio of the extraction process is dynamically adjusted according to the residual effective components in the meal. The solvent ratio is then adjusted by controlling the solvent mixing unit through the control unit.

[0011] Step E: Continuous production, repeating the above steps, keeping the solvent ratio consistent with the process requirements;

[0012] The high-efficiency extraction device includes an extraction unit, a solvent recovery unit, several solvent ratio detection units, a solvent blending unit, a meal detection unit, and a control unit.

[0013] A further improvement of the technical solution of the present invention is that: the extraction unit is connected to the solvent recovery unit, the solvent recovery unit is connected in sequence to the solvent ratio detection unit one and the solvent preparation unit, the solvent preparation unit is connected in sequence to the solvent ratio detection unit two and the meal detection unit, and the control unit performs unified control over the extraction unit, the solvent recovery unit, the solvent ratio detection units, the solvent preparation unit and the meal detection unit.

[0014] A further improvement of the technical solution of the present invention is as follows: the extraction unit includes a drag chain extractor or a rotary extractor for extracting effective components; the solvent recovery unit includes a rising or falling film device and a condensation device for evaporating and recovering the solvent; the solvent ratio detection unit includes a densitometer, a refractometer or a near-infrared spectrometer for detecting the proportion of different solvents in the mixed solvent; the meal detection unit includes a near-infrared spectrometer; the control unit includes an industrial computer, automatic valves and a dispensing pump; the solvent preparation unit includes several solvent tanks and a solvent preparation tank, the solvent tanks are connected to the extraction unit, and the middle section of the extraction unit is connected to the solvent ratio detection unit.

[0015] A further improvement of the technical solution of the present invention is that the solvent ratio is detected at the condensation recovery, after blending and in the middle of the extraction unit, and the solvent is added to the blending tank of the solvent blending unit and the middle of the extraction unit to blend to the required ratio of the process.

[0016] A further improvement of the technical solution of the present invention is that: for two solvent extraction systems that are clean, solvent ratio detection unit one and solvent ratio detection unit two use a densitometer or refractometer to detect the solvent ratio, wherein the refractometer is equipped with an ultrasonic cleaning device; for solvents containing two or more solvents or containing materials, solvent ratio detection unit one and solvent ratio detection unit two use a near-infrared spectrometer for detection.

[0017] A further improvement to the technical solution of this invention is that the content of effective components in the meal is detected using a diffuse reflectance near-infrared spectrometer.

[0018] The steps for establishing a solvent ratio detection model using a near-infrared spectrometer for solvent ratio detection are as follows:

[0019] Step 1) Mix the mixed solvents to be tested in different proportions;

[0020] Step 2) The mixed solvents with different proportions include mixed solvents in which the highest proportion of any one solvent is higher than the highest proportion in the actual production process, and mixed solvents in which the lowest proportion of any one solvent is lower than the lowest proportion in the actual production process.

[0021] Step 3) Dry the corresponding extract paste, add different batches of dried extract paste to the prepared mixed solvent in different proportions, and dilute the extract concentration to between 0.5% and 5%.

[0022] Step 4) Collect the near-infrared spectrum of the solution prepared in the previous step, and establish a solvent ratio prediction model based on the known solvent ratio.

[0023] A further improvement of the technical solution of the present invention is that: the mixed solvent is a new solvent of analytical grade, and there are two or more types of solvents, wherein the proportion of a single solvent is not less than 0.5% and not more than 99.5%, the preparation is carried out by volume method, and the spectral acquisition method is transmission or transmission and reflection.

[0024] A further improvement to the technical solution of the present invention is that: in step 3), the extract is dried in an oven at a temperature of 50-55°C until the solvent residue is less than 5 ppm, and the amount of sample added from the same batch of extract does not exceed 3.

[0025] A further improvement of the technical solution of the present invention is that the preprocessing method is SG smoothing + standard normal transformation, the spectral range is 1050nm-1550nm, the modeling method is PLS, and the number of factors is 4.

[0026] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are as follows:

[0027] This invention establishes a method for efficient extraction of plant raw materials by online measurement of solvent ratio, which not only improves the quality of the extract, but also increases the extraction yield and reduces environmental pollution. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a solvent ratio detection and mixing device;

[0029] Figure 2 This is a flowchart of solvent preparation;

[0030] Figure 3 This is a rendering of the near-infrared spectroscopy solvent ratio model;

[0031] Figure 4 This is a diagram showing the effect of automatic solvent ratio adjustment;

[0032] Among them, 1. Solvent mixing tank, 2. Solvent tank, 3. Solvent recovery unit, 4. Extraction unit, 5. Control unit, 6. Solvent ratio detection unit one, 7. Meal detection unit, 8. Solvent ratio detection unit three, and 9. Solvent ratio detection unit two. Detailed Implementation

[0033] An apparatus for efficient extraction of plant raw materials by online adjustment of solvent ratio includes a solvent recovery unit 3, an extraction unit 4, several solvent ratio detection units, a solvent preparation unit, a meal detection unit 7, and a control unit 5. The extraction unit 4 is connected to the solvent recovery unit 3. The solvent recovery unit 3 is sequentially connected to the first solvent ratio detection unit 6 and the solvent preparation unit. The solvent preparation unit is sequentially connected to the second solvent ratio detection unit 9, the extraction unit 4, and the meal detection unit 7. The middle section of the extraction unit is connected to the third solvent ratio detection unit 8. The control unit 5 provides unified control over the extraction unit 4, the solvent recovery unit 3, the several solvent ratio detection units, the solvent preparation unit, and the meal detection unit 7.

[0034] Extraction unit 4 includes a drag chain extractor or a rotary extractor for extracting active ingredients; solvent recovery unit 3 includes a rising or falling film device and a condenser for evaporating and recovering solvents; solvent ratio detection unit includes a densitometer, a refractometer or a near-infrared spectrometer for detecting the proportion of different solvents in a mixed solvent; meal detection unit 7 includes a near-infrared spectrometer; control unit 5 includes an industrial computer, automatic valves and a dispensing pump; solvent preparation unit includes several solvent tanks 2 and solvent preparation tank 1, both of which are connected to extraction unit 4.

[0035] A method for efficiently extracting plant raw materials using a high-efficiency extraction device by adjusting the solvent ratio online includes the following steps:

[0036] Step A: Solvent recovery unit 3 evaporates and condenses the recovered solvent, then detects the proportion of condensed and recovered solvent online and sends it to the solvent blending unit.

[0037] Step B: The solvent preparation unit calculates the amount of new solvent to be added based on the test results. The control unit 5 controls the solvent tank 2 of the solvent preparation unit to deliver the new solvent to the solvent preparation tank 1 and mix it. The prepared solvent is tested again to confirm the ratio, and then enters the extraction unit 4.

[0038] Step C: Detect the solvent ratio in the middle section of extraction unit 4, and add new solvent from solvent tank 2 to extraction unit 4 according to process requirements;

[0039] Step D: The meal detection unit 7 detects the meal from the extraction unit 4. The solvent ratio of the extraction process is dynamically adjusted according to the residual effective components in the meal. The solvent ratio is then adjusted by the solvent mixing unit controlled by the control unit 5.

[0040] Step E: Continuous production, repeating the above steps, keeping the solvent ratio consistent with the process requirements.

[0041] The solvent ratio was measured at the condensation recovery, after blending, and in the middle of the extraction unit. Solvent was added to the blending tank of the solvent blending unit and in the middle of the extraction unit to adjust to the required ratio.

[0042] For two solvent extraction systems that are clean, solvent ratio detection units 1-6 and 2-9 use a densitometer or refractometer to detect the solvent ratio, with the refractometer equipped with an ultrasonic cleaning device; for solvents containing two or more solvents or materials, solvent ratio detection units 1-6 and 2-9 use a near-infrared spectrometer for detection.

[0043] The steps for establishing a solvent ratio detection model using a near-infrared spectrometer for solvent ratio detection are as follows:

[0044] Step 1) Use a pipette to accurately measure different volumes of the solvent to be tested and mix them according to different volume ratios.

[0045] Step 2) The mixed solvents with different proportions include mixed solvents in which the highest proportion of any one solvent is higher than the highest proportion in the actual production process and mixed solvents in which the lowest proportion of any one solvent is lower than the lowest proportion in the actual production process, and the proportion of a single solvent is not less than 0.5% and not more than 99.5%.

[0046] Step 3) Dry the corresponding extract paste, add different batches of dried extract paste to the prepared mixed solvents of different proportions, and dilute the extract concentration to between 0.5% and 5%; dry the extract paste in an oven at 50-55℃ until the solvent residue is less than 5ppm, and add no more than 3 samples from the same batch of extract.

[0047] Step 4) Collect the near-infrared spectrum of the solution prepared in the previous step, and establish a solvent ratio prediction model based on the known solvent ratio.

[0048] The mixed solvents used for preparation are new solvents of analytical grade, with two or more solvents, the proportion of a single solvent being no less than 0.5% and no more than 99.5%. The preparation is carried out by volumetric method, and the spectral acquisition method is transmission or transmission-reflection.

[0049] The preprocessing method was SG smoothing + standard normal transformation, the spectral range was 1050nm-1550nm, the modeling method was PLS, and the number of factors was 4.

[0050] The content of effective components in the meal was detected using a diffuse reflectance near-infrared spectrometer.

[0051] The following are actual production examples of applying the apparatus and method of this application:

[0052] Example 1: High-efficiency extraction of capsaicin

[0053] Capsanthin was extracted from chili pepper granules using a mixed solvent of hexane and ethanol in a ratio of 3-3.5:1. The extraction temperature was 60°C, and a rotary extractor was used with a feed-to-liquid ratio of 1:3. After concentration, the solvent was recovered by condensation, and the solvent ratio was found to be 5.2:1. 3 cubic meters of recovered solvent and 0.35 cubic meters of fresh ethanol were added to the solvent mixing tank, resulting in a hexane-to-ethanol mixed solvent ratio of 3.02:1. At the extraction inlet, the actual ratio was 3.1:1. At the rotary pump, the solvent ratio was measured at 3.7:1, with a total solvent volume of 9 cubic meters. 0.33 cubic meters of ethanol were added to the system, bringing the hexane-to-ethanol mixed solvent ratio to 3.15:1. Following this process, the weight yield was 8.05%, and the content yield was 98.14%.

[0054] Example 2: High-efficiency extraction of capsaicin

[0055] Capsanthin was extracted from chili pepper granules using a mixed solvent of hexane and ethanol. The optimal hexane:ethanol ratio was 3–3.5:1. The extraction temperature was 60°C, and a rotary extractor was used with a feed-to-liquid ratio of 1:3. After concentration, the solvent was recovered by condensation. The solvent ratio was found to be 4.1:1. 3 cubic meters of recovered solvent and 0.18 cubic meters of fresh ethanol were added to the solvent mixing tank, resulting in a solvent ratio of 3.14:1. Testing at the extraction inlet revealed an actual ratio of 3.15:1. At the rotary pump, the solvent ratio was measured at 3.81:1, with a total solvent volume of 9 cubic meters. 0.5 cubic meters of ethanol were added to the system, bringing the solvent ratio to 3.01:1. Following this process, the weight yield was 8.12%, and the content yield was 98.11%.

[0056] Example 3: High-efficiency extraction of capsaicin

[0057] Capsanthin was extracted from chili pepper granules using a mixed solvent of hexane and ethanol. The optimal hexane:ethanol ratio was 3:1 to 3.5:1. The extraction temperature was 60°C, and a rotary extractor was used with a feed-to-liquid ratio of 1:3. After concentration, the solvent was recovered by condensation. The solvent ratio was found to be 2.2:1. 3 cubic meters of recovered solvent and 0.75 cubic meters of fresh hexane were added to the solvent mixing tank, resulting in a solvent ratio of 3.01:1. The actual ratio was confirmed to be 3.0:1 at the extraction inlet. At the rotary pump, the solvent ratio was measured at 3.56:1, with a total solvent volume of 9 cubic meters. 0.2 cubic meters of ethanol were added to the system, bringing the solvent ratio to 3.23:1. Following this process, the weight yield was 8.21%, and the content yield was 98.21%.

[0058] Example 4: High-efficiency extraction of capsaicin

[0059] The extraction of capsanthin from chili pepper granules used a mixed solvent of hexane and ethanol at a ratio of 3.5:1. At this stage, the residual effective component in the feed was detected to be 0.6%, the extraction temperature was 60°C, the extractor was a rotary extractor, and the feed-to-liquid ratio was 1:3. To improve extraction efficiency, the hexane:ethanol ratio was changed to 3.2:1, all other conditions unchanged. After concentration of the extract, the solvent was condensed and recovered, and the solvent ratio was detected to be 4.6:1. 3 cubic meters of recovered solvent and 0.24 cubic meters of new ethanol were added to the solvent mixing tank, resulting in a solvent ratio of 3.19:1. The actual ratio was confirmed to be 3.19:1 at the extraction inlet. At the rotary pump in the middle stage, the solvent ratio was detected to be 3.42:1, with a total solvent volume of 9 cubic meters. 0.06 cubic meters of ethanol were added to the system, bringing the solvent ratio to 3.32:1. The yield by weight is 8.16%, the content yield is 98.16%, and the effective component residue in the meal is 0.21%.

[0060] Example 5: High-efficiency extraction of capsaicin

[0061] The extraction of capsanthin from chili pepper granules used a mixed solvent of hexane and ethanol at a ratio of 3.36:1. At this stage, the residual effective component in the feed was detected at 0.45%, the extraction temperature was 60°C, the extractor was a rotary extractor, and the feed-to-liquid ratio was 1:3. To improve extraction efficiency, the hexane:ethanol ratio was changed to 3.1:1, all other conditions unchanged. After concentration, the solvent was recovered by condensation, and the solvent ratio was detected at 4.2:1. 3 cubic meters of recovered solvent and 0.21 cubic meters of new ethanol were added to the solvent mixing tank, resulting in a solvent ratio of 3.14:1. The actual ratio, detected at the extraction inlet, was 3.13:1. At the rotary pump in the middle stage, the solvent ratio was detected at 3.47:1, with a total solvent volume of 9 cubic meters. 0.08 cubic meters of ethanol were added to the system, bringing the solvent ratio to 3.11:1. The yield by weight is 8.14%, the content yield is 98.23%, and the effective component residue in the meal is 0.17%.

[0062] Comparative Example 1:

[0063] Using the same batch of chili pepper raw materials as in Example 4, capsanthin was extracted from the chili pepper granules using a mixed solvent of hexane and ethanol. The optimal hexane:ethanol ratio was 3:1 to 3.5:1. The extraction temperature was 60 degrees Celsius, and a rotary extractor was used. The material-to-liquid ratio was 1:3. After concentration, the solvent was condensed and recovered. The solvent ratio was found to be 4.2:1. The recovered solvent and fresh ethanol were added to the solvent mixing tank, resulting in a mixed solvent ratio of 3.05:1 for hexane and ethanol. The actual ratio was 3.15:1 as measured at the extraction inlet. Further extraction with this solvent yielded a weight yield of 7.85%, a content yield of 96.03%, and a residual effective component in the pulp of 2.15%.

[0064] Comparative Example 2:

[0065] Using the same batch of chili pepper raw materials as in Example 4, capsanthin was extracted from the chili pepper granules using a mixed solvent of hexane and ethanol. The optimal hexane:ethanol ratio was 3:1 to 3.5:1. The extraction temperature was 60 degrees Celsius, and a rotary extractor was used. The material-to-liquid ratio was 1:3. After concentration, the solvent was condensed and recovered. The solvent ratio was found to be 5.6:1. The recovered solvent and ethanol were added to the solvent mixing tank, resulting in a solvent ratio of 3.14:1. The actual ratio was 3.2:1 as detected at the extraction inlet. Further extraction with this solvent yielded a weight yield of 7.63%, a content yield of 94.11%, and a residual effective component in the pulp of 3.75%.

[0066] Comparative Example 3:

[0067] Using the same batch of chili peppers as in Example 5, capsanthin was extracted from the chili pepper granules using a mixed solvent of hexane and ethanol. The optimal hexane:ethanol ratio was 3:1 to 3.5:1. The extraction temperature was 60 degrees Celsius, and a rotary extractor was used. The material-to-liquid ratio was 1:3. After concentration, the solvent was condensed and recovered. The solvent ratio was found to be 5.6:1. The recovered solvent and ethanol were added to the solvent mixing tank, resulting in a solvent ratio of 3.03:1. The actual ratio was 3.1:1 as detected at the extraction inlet. Further extraction with this solvent yielded a weight yield of 8.85%, a content yield of 98.42%, and a residual effective component in the pulp of 0.24%.

[0068] Table 1: Comparison of chili granule extraction effects

[0069]

[0070] As can be seen from the above examples and comparative examples, effectively monitoring and adjusting the solvent ratio can improve the extraction efficiency of plant raw materials, reduce the residue of effective components in the meal, and improve process stability. Comparative Example 3, due to its high ethanol content, extracted more other components, resulting in a less significant increase in content yield, which affected product quality and increased subsequent refining costs.

[0071] These embodiments demonstrate improvements achieved by adjusting the ratio of mixed solvents. Each embodiment incorporates specific monitoring techniques to ensure precise control and optimization of the extraction process. The above descriptions are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this invention, based on the technical solutions and inventive concepts of the present invention, should be within the scope of protection of this invention.

Claims

1. A method for efficient extraction of plant raw materials by adjusting the solvent ratio online, characterized in that: Using a high-efficiency extraction device, the extraction unit (4) includes a drag chain extractor or a rotary extractor to extract the active ingredients, including the following steps: Step A: The solvent recovery unit (3) evaporates and condenses the mixed solvent recovered by the extraction unit (4), detects the proportion of the mixed solvent recovered by condensation online, and sends it to the solvent preparation unit. Step B: The solvent preparation unit calculates the amount of new solvent to be added based on the detection results. The control unit (5) controls the solvent tank (2) of the solvent preparation unit to deliver the new solvent to the solvent preparation tank (1) and mix it. The mixed solvent is tested again to confirm the ratio, and then enters the extraction unit (4). Step C: Detect the ratio of mixed solvents in the middle section of the extraction unit (4), and add new solvent from the solvent tank (2) to the extraction unit (4) according to process requirements; Step D: The meal detection unit (7) detects the meal from the extraction unit (4). The ratio of extraction solvent is dynamically adjusted according to the residual effective components in the meal. Then, the ratio of mixed solvent is adjusted by controlling the solvent mixing unit through the control unit (5). Step E: Continuous production, repeating the above steps, keeping the mixed solvent ratio consistent with the process requirements; The high-efficiency extraction device includes an extraction unit (4), a solvent recovery unit (3), several solvent ratio detection units, a solvent blending unit, a meal detection unit (7), and a control unit (5).

2. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The extraction unit (4) is connected to the solvent recovery unit (3). The solvent recovery unit (3) is connected in sequence to the solvent ratio detection unit one (6) and the solvent preparation unit. The solvent preparation unit is connected in sequence to the solvent ratio detection unit two (9), the extraction unit (4), and the meal detection unit (7). The control unit (5) performs unified control on the extraction unit (4), the solvent recovery unit (3), several solvent ratio detection units, solvent preparation units, and meal detection units (7).

3. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 2, characterized in that: The solvent recovery unit (3) includes rising or falling film equipment and condensation equipment to evaporate and recover solvents; the solvent ratio detection unit includes a densitometer, refractometer or near-infrared spectrometer to detect the ratio of different solvents in the mixed solvent; the meal detection unit (7) includes a near-infrared spectrometer; the control unit (5) includes an industrial computer, automatic valves and infusion pumps; the solvent preparation unit includes several solvent tanks (2) and solvent preparation tanks (1); the solvent tanks (2) are connected to the extraction unit (4); the middle section of the extraction unit is connected to the solvent ratio detection unit (8).

4. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The solvent ratio was measured at the condensation recovery, after blending, and in the middle of the extraction unit. Solvent was added to the blending tank of the solvent blending unit and in the middle of the extraction unit to adjust to the required ratio.

5. The method for efficient extraction of plant raw materials by online adjustment of solvent ratio according to claim 1, characterized in that: In the solvent ratio detection unit, for two solvent extraction systems that are clean, solvent ratio detection unit one and solvent ratio detection unit two use a densitometer or refractometer to detect the solvent ratio, wherein the refractometer is equipped with an ultrasonic cleaning device; for solvents containing two or more solvents or containing materials, solvent ratio detection unit one and solvent ratio detection unit two use a near-infrared spectrometer for detection.

6. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The content of effective components in the meal was detected using a diffuse reflectance near-infrared spectrometer.

7. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The steps for establishing a solvent ratio detection model using a near-infrared spectrometer for solvent ratio detection are as follows: Step 1) Mix the mixed solvents to be tested in different proportions; Step 2) The mixed solvents with different proportions include mixed solvents in which the highest proportion of any one solvent is higher than the highest proportion in the actual production process, and mixed solvents in which the lowest proportion of any one solvent is lower than the lowest proportion in the actual production process. Step 3) Dry the corresponding extract paste, add different batches of dried extract paste to the prepared mixed solvents of different proportions, and dilute the extract concentration to between 0.5% and 5%. Step 4) Collect the near-infrared spectrum of the solution prepared in the previous step, and establish a solvent ratio prediction model based on the known solvent ratio.

8. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 7, characterized in that: The mixed solvents used for preparation are new solvents of analytical grade, with two or more solvents, the proportion of a single solvent being no less than 0.5% and no more than 99.5%. The preparation is carried out by volumetric method, and the spectral acquisition method is transmission or reflection.

9. The method for efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 7, characterized in that: In step 3), the extract is dried in an oven at a temperature of 50-55°C until the solvent residue is less than 5 ppm. The amount of sample added from the same batch of extract should not exceed 3.

10. A method for efficient extraction of plant raw materials by adjusting the solvent ratio online, as described in claim 7, characterized in that: The preprocessing method was SG smoothing + standard normal transformation, the spectral range was 1050nm-1550nm, the modeling method was PLS, and the number of factors was 4.

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