A process for extracting crude protein from Radix Codonopsis pilosula

Abstract

The present invention belongs to the technical field of crude protein extraction, specifically, a crude protein extraction process of radix rosatidis, and the extraction process includes pulping, extraction, mixing, precipitation and purification. The crude protein extraction process of radix rosatidis provided by the present invention abandons the traditional alkali dissolution acid precipitation method, adopts 8-hydroxyquinoline sulfate as a precipitating agent, 8-hydroxyquinoline sulfate has the characteristics of acid in aqueous solution, and there are van der Waals forces, hydrogen bonding forces, etc. between the quinoline group, hydroxyl group and crude protein in 8-hydroxyquinoline sulfate, not only can the crude protein in the concentrate be precipitated out faster, and the 8-hydroxyquinoline sulfate in the crude extraction precipitation can be removed by the principle of primary battery later, and the purity of crude protein can be improved; the crude protein extraction rate of radix rosatidis extracted by the present invention is more than 98%, and the purity is more than 99%.

Description

Technical Field

[0001] The invention belongs to the technical field of crude protein extraction, and in particular relates to a process for extracting crude protein from Radix Codonopsis pilosulae. Background Art

[0002] Luohan ginseng is a specialty of Shan County, Heze City, Shandong Province. It has high nutritional and medicinal value. Luohan ginseng contains rich minerals, crude fiber, crude protein and starch. After consumption, it can lower blood pressure and blood sugar, enhance the human immune mechanism, and has the effect of prolonging life. The main effect is crude protein. Therefore, from the perspective of giving full play to the nutritional and medicinal value of Luohan ginseng, the research on extracting crude protein from Luohan ginseng has important economic significance.

[0003] According to the analysis of Shandong Agricultural University, the starch content in the dry matter of Luohan ginseng is the highest, accounting for 38.2%, followed by crude protein accounting for 17.3%, and crude fiber accounting for 15.2%. Crude protein has unique physical and chemical properties and health functions. At present, there are few studies on the extraction of crude protein from Luohan ginseng. The main methods for extracting crude protein are enzymatic method, alkali dissolution and acid precipitation method, etc. Patent No. "201610270797.6" named "A method for extracting crude protein from maca" adopts the method of alkali dissolution plus ultrasonic extraction to shorten the extraction rate and improve the extraction efficiency, but the purity of crude protein extracted by this method is not high; Patent No. "201710093633.5" named "A method for extracting walnut crude protein from walnut meal" uses alkali solution to extract the defatted walnut meal and sulfuric acid precipitation. The extraction rate of crude protein is 51%, the purity is 75%, the acid precipitation time is long, and the extraction effect is not ideal. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a crude protein extraction process of Polygonum multiflorum to achieve the invention purpose of improving the crude protein extraction rate and purity.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A process for extracting crude protein from Radix Codonopsis pilosulae comprises the following steps:

[0007] S1, pulping: washing, peeling, and cutting the radix polygoni lobatae into pieces, and beating the pieces with a colloid mill to prepare a slurry, and then washing the pieces with ethanol aqueous solution and deionized water in sequence, and passing the pieces through a 50-70 mesh sieve to obtain a slurry;

[0008] S2, extraction: adding the filter pulp into an ammonia solution and stirring for 20 to 30 minutes, ultrasonically extracting, centrifuging, and filtering to obtain a filtrate and a filter residue;

[0009] S3, mixing: washing the filter residue with deionized water for 2 to 3 times to obtain a washing solution, adding the washing solution to the filtrate and mixing evenly to obtain a mixed solution;

[0010] S4, precipitation: the mixed solution is concentrated and dehydrated under reduced pressure, and a concentrated solution is obtained after cooling to 20-25° C.; a precipitation agent 8-hydroxyquinoline sulfate is added to the concentrated solution, stirred for 5-10 minutes, and then allowed to stand, and the temperature is raised to 30-40° C. and then a precipitate is waited for precipitation, and the precipitate is washed with deionized water and filtered to obtain a crude extraction precipitate;

[0011] S5. Purification: Add the crude extraction precipitate to deionized water and stir to obtain a crude extraction mixture; divide the glass container into two parts, A and B, using a proton exchange membrane, and then add the crude extraction mixture to part A of the glass container; add a dilute sulfuric acid solution to part B of the glass container, insert a zinc plate as a negative electrode into the crude extraction mixture, insert a carbon plate as a positive electrode into the dilute sulfuric acid solution, connect the zinc plate and the carbon plate to form a primary cell, and the Zn generated on the surface of the zinc plate 2+ It reacts with the quinoline group in 8-hydroxyquinoline sulfate to generate a complex precipitate that is deposited on the surface of the zinc plate. Under the action of the proton exchange membrane, the anions in the primary cell are isolated in part B, thereby removing the 8-hydroxyquinoline sulfate in the crude extraction precipitate. After the reaction is completed, vacuum filtration is performed from part A, and after washing with deionized water and freeze-drying, the crude protein of Polygonum multiflorum is obtained.

[0012] Preferably, the beating time in S1 is 5 to 10 minutes.

[0013] Preferably, the mass fraction of the ethanol aqueous solution of S1 is 50-60%.

[0014] Preferably, the pH of the ammonia solution in S2 is 9-11, and the mass ratio of the filter pulp to the ammonia solution is 1:10-15.

[0015] Preferably, the ultrasonic extraction in S2 takes place for 50 to 70 minutes at a temperature of 40 to 50°C.

[0016] Preferably, the centrifugal speed in S2 is 2000-3000 r / min, and the time is 15-25 min.

[0017] Preferably, the mass of the concentrated liquid in S4 is 35-45% of the mass of the mixed liquid.

[0018] Preferably, the temperature of the reduced pressure concentration in S4 is 50-60° C., and the rotation speed is 100-150 rpm.

[0019] Preferably, the amount of 8-hydroxyquinoline sulfate added in S4 is 5-7% of the mass of the concentrated solution.

[0020] Preferably, the time for precipitation in S4 is 8 to 12 minutes.

[0021] Preferably, the concentration of the dilute sulfuric acid solution in S5 is 0.05-0.1 mol / L.

[0022] Preferably, the mass ratio of the crude extraction precipitate to deionized water in S5 is 1:2-3.

[0023] Preferably, the amount of the dilute sulfuric acid solution added in S5 is such that the initial pH of the reaction is 3.5-4.

[0024] Preferably, the reaction time in S5 is 30 to 40 minutes.

[0025] Preferably, the vacuum degree of the vacuum filtration in S5 is -0.05 to 0.1 MPa.

[0026] Preferably, the freeze-drying temperature in S5 is -40 to -30°C, and the time is 12 to 18 hours.

[0027] Hydroxyquinoline sulfate contains sulfate groups, which release hydrogen ions in aqueous solution and exhibit acidic properties. Therefore, by controlling the amount of 8-hydroxyquinoline sulfate added and adjusting the pH of the concentrate to reach or approach the isoelectric point of the crude protein, the crude protein in the concentrate can be precipitated. In addition, there are van der Waals forces and hydrogen bonding forces between the quinoline groups and hydroxyl groups in 8-hydroxyquinoline sulfate and the crude protein, which can precipitate the crude protein in the concentrate more quickly.

[0028] Due to the interaction between 8-hydroxyquinoline sulfate and crude protein, most of the 8-hydroxyquinoline sulfate that has not been washed away still exists in the crude extraction precipitate obtained after washing with deionized water and filtration. Using the principle of the galvanic cell and the proton exchange membrane, the proton exchange membrane only allows H + and water, so the H of dilute sulfuric acid in part B + You can enter part A. The initial pH of the entire galvanic cell is set to 3.5-4, which will not affect the properties of crude protein. Under the action of the galvanic cell reaction, an oxidation reaction occurs on the surface of the zinc plate at the negative electrode to produce a higher concentration of Zn 2+ , the quinoline group in 8-hydroxyquinoline sulfate reacts with Zn on the surface of the zinc plate 2+ The reaction generates a complex precipitate that is deposited on the surface of the zinc plate; H + Move to the positive carbon plate to generate hydrogen. Under the action of the proton exchange membrane, SO4 in part B 2- It will not enter part A. Finally, the crude protein is separated by vacuum filtration, thereby removing 8-hydroxyquinoline sulfate in the crude extraction precipitate and improving the purity of the crude protein.

[0029] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are:

[0030] 1. The crude protein extraction process of Radix Polygoni Multiflori provided by the present invention has high extraction efficiency, fast acid precipitation time, and the crude protein extraction rate is more than 98%.

[0031] 2. The crude protein extraction process of Radix Polygoni Multiflori provided by the present invention abandons the traditional alkali dissolution and acid precipitation method, and adopts 8-hydroxyquinoline sulfate, which can not only precipitate the crude protein in the concentrate faster, but also can subsequently remove the 8-hydroxyquinoline sulfate in the crude extraction precipitate by using the galvanic cell principle, thereby improving the purity of the crude protein; the purity of the crude protein of Radix Polygoni Multiflori extracted by the present invention is more than 99%.

[0032] 3. The entire extraction process of the present invention has a short cycle, and can reduce process costs when put into actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the original battery structure diagram in step S5. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with specific embodiments and drawings.

[0035] Example 1 S1, pulping: washing, peeling, and cutting the radix polygoni lobatae into pieces, and beating the pieces with a colloid mill to prepare a slurry, and then washing the pieces with ethanol aqueous solution and deionized water in sequence, and passing the pieces through a 60-mesh sieve to obtain a slurry;

[0036] S2, extraction: adding the filter pulp into an ammonia solution and stirring for 25 minutes, ultrasonic extraction, centrifugation, and filtration to obtain a filtrate and a filter residue;

[0037] S3, mixing: washing the filter residue with deionized water for 3 times to obtain a washing solution, adding the washing solution to the filtrate and mixing well to obtain a mixed solution;

[0038] S4, precipitation: the mixed solution is concentrated and dehydrated under reduced pressure, and a concentrated solution is obtained after cooling to 23°C; a precipitation agent 8-hydroxyquinoline sulfate is added to the concentrated solution, stirred for 7 minutes and then allowed to stand, and the temperature is raised to 35°C and then a precipitate is waited for precipitation, and the precipitate is washed with deionized water and filtered to obtain a crude extraction precipitate;

[0039] S5. Purification: adding the crude extraction precipitate into deionized water and stirring to obtain a crude extraction mixture; using a proton exchange membrane to divide the glass container into two parts A and B, and then adding the crude extraction mixture into part A of the glass container; adding a dilute sulfuric acid solution into part B of the glass container, inserting a zinc plate as a negative electrode into the crude extraction mixture, inserting a carbon plate as a positive electrode into the dilute sulfuric acid solution, connecting the zinc plate and the carbon plate to form a primary cell, and after the reaction is completed, vacuum filtration is performed from part A, and after washing with deionized water and freeze-drying, the crude protein of Radix Panacis radix is ​​obtained.

[0040] The beating time in S1 is 7 minutes.

[0041] The mass fraction of the ethanol aqueous solution of S1 is 55%.

[0042] The pH of the ammonia solution in S2 is 11, and the mass ratio of the filter pulp to the ammonia solution is 1:12.

[0043] The ultrasonic extraction time in S2 is 60 minutes and the temperature is 45°C.

[0044] The centrifugal speed in S2 is 2500 r / min and the time is 20 min.

[0045] The mass of the concentrated liquid in S4 is 40% of the mass of the mixed liquid.

[0046] The temperature of the reduced pressure concentration in S4 is 55° C. and the rotation speed is 130 rpm.

[0047] The amount of 8-hydroxyquinoline sulfate added in S4 is 6% of the mass of the concentrated solution.

[0048] The time for precipitation in S4 is 8 minutes.

[0049] The concentration of the dilute sulfuric acid solution in S5 is 0.7 mol / L.

[0050] The mass ratio of the crude extraction precipitate to deionized water in S5 is 1:2.

[0051] The amount of the dilute sulfuric acid solution added in S5 is such that the initial pH of the reaction is 4.

[0052] The reaction time in S5 is 40 min.

[0053] The vacuum degree of the vacuum filtration in S5 is 0.05 MPa.

[0054] The freeze drying temperature in S5 is -35°C and the time is 16 hours.

[0055] Example 2 S1, pulping: washing, peeling, and cutting the radix polygoni lobatae into pieces, and beating the pieces with a colloid mill to prepare a slurry, and then washing the pieces with ethanol aqueous solution and deionized water in sequence, and filtering the pieces through a 50-mesh sieve to obtain a slurry;

[0056] S2, extraction: adding the filter pulp into an ammonia solution and stirring for 20 minutes, ultrasonic extraction, centrifugation, and filtration to obtain a filtrate and a filter residue;

[0057] S3, mixing: washing the filter residue twice with deionized water to obtain a washing solution, adding the washing solution to the filtrate and mixing well to obtain a mixed solution;

[0058] S4, precipitation: the mixed solution is concentrated and dehydrated under reduced pressure, and a concentrated solution is obtained after cooling to 20°C; a precipitation agent 8-hydroxyquinoline sulfate is added to the concentrated solution, stirred for 5 minutes and then allowed to stand, and the temperature is raised to 30°C and then a precipitate is waited for precipitation, and the precipitate is washed with deionized water and filtered to obtain a crude extraction precipitate;

[0059] S5. Purification: adding the crude extraction precipitate into deionized water and stirring to obtain a crude extraction mixture; using a proton exchange membrane to divide the glass container into two parts A and B, and then adding the crude extraction mixture into part A of the glass container; adding a dilute sulfuric acid solution into part B of the glass container, inserting a zinc plate as a negative electrode into the crude extraction mixture, inserting a carbon plate as a positive electrode into the dilute sulfuric acid solution, connecting the zinc plate and the carbon plate to form a primary cell, and after the reaction is completed, vacuum filtration is performed from part A, and after washing with deionized water and freeze-drying, the crude protein of Radix Panacis radix is ​​obtained.

[0060] The beating time in S1 is 5 minutes.

[0061] The mass fraction of the ethanol aqueous solution of S1 is 50%.

[0062] The pH of the ammonia solution in S2 is 9, and the mass ratio of the filter pulp to the ammonia solution is 1:10.

[0063] The ultrasonic extraction time in S2 is 50 min and the temperature is 40°C.

[0064] The centrifugal speed in S2 is 2000 r / min and the time is 25 min.

[0065] The mass of the concentrated liquid in S4 is 35% of the mass of the mixed liquid.

[0066] The temperature of the reduced pressure concentration in S4 is 50° C. and the rotation speed is 100 rpm.

[0067] The amount of 8-hydroxyquinoline sulfate added in S4 is 5% of the mass of the concentrated solution.

[0068] The time for precipitation in S4 is 12 minutes.

[0069] The concentration of the dilute sulfuric acid solution in S5 is 0.05 mol / L.

[0070] The mass ratio of the crude extraction precipitate to deionized water in S5 is 1:2.5.

[0071] The amount of the dilute sulfuric acid solution added in S5 is such that the initial pH of the reaction is 3.7.

[0072] The reaction time in S5 is 35 min.

[0073] The vacuum degree of the vacuum filtration in S5 is -0.05MPa.

[0074] The freeze drying temperature in S5 is -40°C and the time is 12 hours.

[0075] Example 3 S1, pulping: washing, peeling, and cutting the radix polygoni lobatae into pieces, and beating the pieces with a colloid mill to prepare a slurry, and then washing the pieces with ethanol aqueous solution and deionized water in sequence, and filtering the pieces through a 70-mesh sieve to obtain a slurry;

[0076] S2, extraction: adding the filter pulp into an ammonia solution and stirring for 30 minutes, ultrasonic extraction, centrifugation, and filtration to obtain a filtrate and a filter residue;

[0077] S3, mixing: washing the filter residue with deionized water for 3 times to obtain a washing solution, adding the washing solution to the filtrate and mixing well to obtain a mixed solution;

[0078] S4, precipitation: the mixed solution is concentrated and dehydrated under reduced pressure, and a concentrated solution is obtained after cooling to 25°C; a precipitation agent 8-hydroxyquinoline sulfate is added to the concentrated solution, and the solution is stirred for 10 minutes and then allowed to stand, and the temperature is raised to 40°C and then a precipitate is waited for precipitation, and the precipitate is washed with deionized water and filtered to obtain a crude extraction precipitate;

[0079] S5. Purification: adding the crude extraction precipitate into deionized water and stirring to obtain a crude extraction mixture; using a proton exchange membrane to divide the glass container into two parts A and B, and then adding the crude extraction mixture into part A of the glass container; adding a dilute sulfuric acid solution into part B of the glass container, inserting a zinc plate as a negative electrode into the crude extraction mixture, inserting a carbon plate as a positive electrode into the dilute sulfuric acid solution, connecting the zinc plate and the carbon plate to form a primary cell, and after the reaction is completed, vacuum filtration is performed from part A, and after washing with deionized water and freeze-drying, the crude protein of Radix Panacis radix is ​​obtained.

[0080] The beating time in S1 is 10 minutes.

[0081] The mass fraction of the ethanol aqueous solution of S1 is 60%.

[0082] The pH of the ammonia solution in S2 is 10, and the mass ratio of the filter pulp to the ammonia solution is 1:15.

[0083] The ultrasonic extraction time in S2 is 70 minutes and the temperature is 50°C.

[0084] The centrifugal speed in S2 is 3000 r / min and the time is 15 min.

[0085] The mass of the concentrated liquid in S4 is 45% of the mass of the mixed liquid.

[0086] The temperature of the reduced pressure concentration in S4 is 60° C. and the rotation speed is 150 rpm.

[0087] The amount of 8-hydroxyquinoline sulfate added in S4 is 7% of the mass of the concentrated solution.

[0088] The time for precipitation in S4 is 10 minutes.

[0089] The concentration of the dilute sulfuric acid solution in S5 is 0.1 mol / L.

[0090] The mass ratio of the crude extraction precipitate to deionized water in S5 is 1:3.

[0091] The amount of the dilute sulfuric acid solution added in S5 is such that the initial pH of the reaction is 3.5.

[0092] The reaction time in S5 is 30 min.

[0093] The vacuum degree of the vacuum filtration in S5 is 0.1 MPa.

[0094] The freeze drying temperature in S5 is -30°C and the time is 18 hours.

[0095] Example 4S1, pulping: washing, peeling, and cutting the radix polygoni lobatae into pieces, and beating the pieces with a colloid mill to prepare a slurry, and then washing the pieces with ethanol aqueous solution and deionized water in sequence, and filtering the pieces through a 70-mesh sieve to obtain a slurry;

[0096] S2, extraction: adding the filter pulp into an ammonia solution and stirring for 30 minutes, ultrasonic extraction, centrifugation, and filtration to obtain a filtrate and a filter residue;

[0097] S3, mixing: washing the filter residue with deionized water for 3 times to obtain a washing solution, adding the washing solution to the filtrate and mixing well to obtain a mixed solution;

[0098] S4, precipitation: the mixed solution is concentrated and dehydrated under reduced pressure, and a concentrated solution is obtained after cooling to 25°C; a precipitation agent 8-hydroxyquinoline sulfate is added to the concentrated solution, and the solution is stirred for 10 minutes and then allowed to stand, and the temperature is raised to 40°C and then a precipitate is waited for precipitation, and the precipitate is washed with deionized water and filtered to obtain a crude extraction precipitate;

[0099] S5. Purification: adding the crude extraction precipitate into deionized water and stirring to obtain a crude extraction mixture; using a proton exchange membrane to divide the glass container into two parts A and B, and then adding the crude extraction mixture into part A of the glass container; adding a dilute sulfuric acid solution into part B of the glass container, inserting a zinc plate as a negative electrode into the crude extraction mixture, inserting a carbon plate as a positive electrode into the dilute sulfuric acid solution, connecting the zinc plate and the carbon plate to form a primary cell, and after the reaction is completed, vacuum filtration is performed from part A, and after washing with deionized water and freeze-drying, the crude protein of Radix Panacis radix is ​​obtained.

[0100] The beating time in S1 is 10 minutes.

[0101] The mass fraction of the ethanol aqueous solution of S1 is 60%.

[0102] The pH of the ammonia solution in S2 is 10, and the mass ratio of the filter pulp to the ammonia solution is 1:15.

[0103] The ultrasonic extraction time in S2 is 70 minutes and the temperature is 50°C.

[0104] The centrifugal speed in S2 is 3000 r / min and the time is 15 min.

[0105] The mass of the concentrated liquid in S4 is 45% of the mass of the mixed liquid.

[0106] The temperature of the reduced pressure concentration in S4 is 60° C. and the rotation speed is 150 rpm.

[0107] The amount of 8-hydroxyquinoline sulfate added in S4 is 7% of the mass of the concentrated solution.

[0108] The time for precipitation in S4 is 10 minutes.

[0109] The concentration of the dilute sulfuric acid solution in S5 is 0.7 mol / L.

[0110] The mass ratio of the crude extraction precipitate to deionized water in S5 is 1:2.

[0111] The amount of the dilute sulfuric acid solution added in S5 is such that the initial pH of the reaction is 4.

[0112] The reaction time in S5 is 40 min.

[0113] The vacuum degree of the vacuum filtration in S5 is 0.05 MPa.

[0114] The freeze drying temperature in S5 is -35°C and the time is 16 hours.

[0115] Comparative Example 1 Representative Example 1 was selected, S5 was removed, and the crude extraction precipitate was directly washed with deionized water and freeze-dried to obtain the radix strychnifoliae crude protein. The rest was consistent with Example 1, as Comparative Example 1.

[0116] Comparative Example 2 Select the representative Example 1, replace the precipitating agent in S4 with a dilute sulfuric acid solution and adjust it to the same pH as S4 in Example 1; remove S5, directly wash the crude extraction precipitate with deionized water, and freeze-dry to obtain the radix strychnifoliae crude protein, and the rest are consistent with Example 1, as Comparative Example 2.

[0117] The crude protein content of Radix Polygoni Multiflori extracted from Examples 1-4 and Comparative Examples 1-2 was detected and analyzed, as shown in Table 1.

[0118] Table 1

[0119] Test items Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Extraction rate (%) 99.23 98.26 98.75 98.8 99.12 99.08 purity(%) 99.82 99.17 99.35 99.61 88.91 92.43 Time for precipitation in S4 (min) 8 12 10 10 8 37

[0120] As can be seen from Table 1, S5 plays a key role in purification. Comparative Example 1 only removes S5, and directly washes the crude extraction precipitate with deionized water and freeze-dries it to obtain the radix strychnifoliae crude protein, and the purity is greatly reduced. This is because there are van der Waals forces and hydrogen bonding forces between 8-hydroxyquinoline sulfate and crude protein, and it is not easy to achieve the effect of complete removal by washing and separation; Compared with Comparative Example 1, Comparative Example 2 replaces the precipitating agent in S4 with a dilute sulfuric acid solution and adjusts it to the same pH as S4 in Example 1. The purity is higher than that of Comparative Example 1, but it still shows a downward trend compared with Example 1. This is because sulfuric acid cannot be completely removed by washing, which affects the purity of the crude protein; and the precipitation time of Comparative Example 2 is longer, indicating that under the same pH conditions, 8-hydroxyquinoline sulfate will accelerate the precipitation of precipitation.

[0121] Note:

[0122] Extraction rate (%) = protein content in crude protein of Radix Codonopsis pilosula (mg / g) / protein content in peeled Radix Codonopsis pilosula (mg / g) × 100%.

[0123] Purity (%) = protein content in radix serrata crude protein / total mass of radix serrata crude protein × 100%.

[0124] Unless otherwise specified, the ratios and percentages described in the present invention are all weight ratios and weight percentages; and the raw materials are all commercially available.

[0125] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for extracting crude protein from Radix Panacis chinensis, characterized in that: The extraction process comprises the following steps: S1, pulping: washing, peeling, and cutting the radix polygoni lobatae into pieces, and beating the pieces with a colloid mill to prepare a slurry, and then washing the pieces with ethanol aqueous solution and deionized water in sequence, and passing the pieces through a 50-70 mesh sieve to obtain a slurry; S2, extraction: adding the filter pulp into an ammonia solution and stirring for 20 to 30 minutes, ultrasonically extracting, centrifuging, and filtering to obtain a filtrate and a filter residue; S3, mixing: washing the filter residue with deionized water for 2 to 3 times to obtain a washing solution, adding the washing solution to the filtrate and mixing evenly to obtain a mixed solution; S4, precipitation: the mixed solution is concentrated and dehydrated under reduced pressure, and a concentrated solution is obtained after cooling to 20-25° C.; a precipitation agent 8-hydroxyquinoline sulfate is added to the concentrated solution, stirred for 5-10 minutes, and then allowed to stand, and the temperature is raised to 30-40° C. and then a precipitate is waited for precipitation, and the precipitate is washed with deionized water and filtered to obtain a crude extraction precipitate; S5. Purification: adding the crude extraction precipitate into deionized water and stirring to obtain a crude extraction mixture; using a proton exchange membrane to divide the glass container into two parts A and B, and then adding the crude extraction mixture into part A of the glass container; adding a dilute sulfuric acid solution into part B of the glass container, inserting a zinc plate as a negative electrode into the crude extraction mixture, inserting a carbon plate as a positive electrode into the dilute sulfuric acid solution, connecting the zinc plate and the carbon plate to form a primary cell, and after the reaction is completed, vacuum filtration is performed from part A, and after washing with deionized water and freeze-drying, the crude protein of Radix Panacis radix is ​​obtained.

2. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The beating time in S1 is 5 to 10 minutes; The mass fraction of the ethanol aqueous solution of S1 is 50-60%.

3. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The pH of the ammonia solution in the S2 is 9-11, and the mass ratio of the filter pulp to the ammonia solution is 1:10-15.

4. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The ultrasonic extraction time in S2 is 50 to 70 minutes and the temperature is 40 to 50° C.; The centrifugal speed in S2 is 2000-3000 r / min, and the time is 15-25 min.

5. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The mass of the concentrated liquid in S4 is 35-45% of the mass of the mixed liquid; The temperature of the reduced pressure concentration in S4 is 50-60° C., and the rotation speed is 100-150 rpm.

6. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The amount of 8-hydroxyquinoline sulfate added in S4 is 5-7% of the mass of the concentrated solution.

7. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The time for precipitation in S4 is 8 to 12 minutes.

8. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The concentration of the dilute sulfuric acid solution in S5 is 0.05-0.1 mol / L; The mass ratio of the crude extraction precipitate to the deionized water in S5 is 1:2-3.

9. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The amount of the dilute sulfuric acid solution added in S5 is such that the initial pH of the reaction is 3.5 to 4; The reaction time in S5 is 30 to 40 minutes.

10. A process for extracting crude protein from Radix Codonopsis pilosulae according to claim 1, characterized in that: The vacuum degree of the vacuum filtration in S5 is -0.05 to 0.1 MPa; The freeze drying temperature in S5 is -40 to -30°C and the time is 12 to 18 hours.

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