Extraction method of plant polysaccharide and plant polysaccharide

Abstract

The invention relates to the technical field of plant polysaccharide extraction, in particular to a plant polysaccharide extraction method and plant polysaccharides, and the extraction method comprises the following steps: carrying out wall breaking treatment on edible mushrooms to obtain wall-broken edible mushroom powder; mixing the edible mushroom powder with an L-cysteine solution according to a solid-liquid ratio of 1g: (10-20) mL to obtain a wall-broken edible mushroom powder solution; adding a plant compound enzyme into the wall-broken edible fungus powder solution, adjusting the pH value to 4.5, heating to 40 DEG C, performing enzymolysis for 1.5-2 hours under the stimulation action of a micro direct-current electric field, and performing enzyme deactivation to obtain a plant polysaccharide crude extract; and deproteinizing the plant polysaccharide extracting solution by using a Sevag method, carrying out alcohol precipitation separation, concentrating and drying to obtain the polysaccharide extract. According to the method disclosed by the invention, an enzymolysis mode under the stimulation of a micro direct-current electric field is adopted, and an L-cysteine solution oscillation soaking mode is combined, so that the extraction rate of the plant polysaccharide can be remarkably improved, and the activity of the plant polysaccharide is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of plant polysaccharide extraction, and in particular to a method for extracting plant polysaccharides and the plant polysaccharides. Background Art

[0002] Plant polysaccharides, also known as plant polysaccharides, are polysaccharides with a degree of polymerization of more than 10 produced by plant cell metabolism. They are compounds composed of many identical or different monosaccharides with α- or β-glycosidic bonds, and are commonly found in plants in nature, including starch, cellulose, polysaccharides, pectin, etc. Studies have found that plant polysaccharides have biological activities such as improving immunity, anti-tumor, lowering blood sugar, anti-oxidation, anti-coagulation, anti-radiation, and protecting the liver. They have been widely used in the food, medicine, and health care industries, and have been favored by more and more researchers.

[0003] At present, the extraction methods of plant polysaccharides mainly include solvent extraction, enzyme-assisted extraction, and instrument-assisted extraction. These extraction methods have certain limitations, such as the consumption of a large amount of organic solvents, complex operation, long extraction time, and low extraction efficiency. For example, solvent extraction is a method of extracting effective ingredients from solid raw materials using solvents. It is necessary to select a suitable solvent, and its concentration, solid-liquid ratio, extraction temperature and time will affect the extraction rate. This method is simple to operate and has a wide range of applications, but it is time-consuming, has a low yield, and is prone to solvent residue problems. If chemical solvents are used for extraction, multiple purification processes are required to remove the residual solvent, which increases production costs. Summary of the invention

[0004] To solve the above problems, the present invention provides a method for extracting plant polysaccharides and plant polysaccharides, which adopts enzymatic hydrolysis under the stimulation of a micro-DC electric field to significantly improve the extraction rate of plant polysaccharides and ensure the activity of plant polysaccharides.

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

[0006] A method for extracting plant polysaccharides comprises the following steps:

[0007] S1, breaking the wall of edible fungi to obtain broken wall edible fungi powder;

[0008] S2, mixing the edible fungus powder with the L-cysteine ​​solution at a ratio of 1 g to (10-20) mL to obtain a wall-broken edible fungus powder solution;

[0009] S3, adding plant complex enzyme to the broken edible fungus powder solution, adjusting the pH value to 4.5, heating to 40° C., and performing enzymolysis for 1.5 to 2 hours under the stimulation of a micro-DC electric field, then inactivating the enzyme to obtain a crude plant polysaccharide extract;

[0010] S4, removing protein from the plant polysaccharide extract by Sevag method, separating by alcohol precipitation, concentrating and drying to obtain a polysaccharide extract.

[0011] Furthermore, in step S1, fresh edible fungi are washed, sliced, dried at 30°C to a moisture content of about 10%, frozen at -15°C, placed in a grinder, and ground until the particle size of the obtained edible fungi powder is about 100 meshes, thereby obtaining broken-wall edible fungi powder.

[0012] Furthermore, in step S2, the mass concentration of the L-cysteine ​​solution is 3 mg / L.

[0013] Furthermore, in step S2, after the edible fungus powder and the cysteine ​​solution are mixed, they are shaken and soaked at 60 rpm to 120 rpm for 15 to 20 minutes.

[0014] Furthermore, in step S3, the current density of the micro DC electric field is 0.096 mA / cm 2 ~0.25mA / cm 2 .

[0015] Furthermore, in step S3, the micro-DC electric field is configured with at least one pair of anode and cathode, and both the cathode and cathode are titanium mesh electrodes or platinum mesh electrodes.

[0016] Furthermore, in step S3, the plant complex enzyme includes pectinase and cellulase, and the mass ratio of pectinase to cellulase is 1:1.

[0017] Furthermore, the edible fungi are Hericium erinaceus and Lentinula edodes, and the mass ratio of the two in the obtained broken-wall edible fungi powder is 2 to 3:1.

[0018] The present invention also provides a plant polysaccharide, including Lentinan and Hericium erinaceus polysaccharide, which are prepared by the above extraction method.

[0019] The present invention has the following beneficial effects:

[0020] The enzymatic hydrolysis under the stimulation of a micro-DC electric field, in coordination with the oscillating soaking of an L-cysteine ​​solution, can significantly improve the extraction rate of plant polysaccharides and ensure the activity of plant polysaccharides. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0022] Figure 1 This is a graph showing the plant polysaccharide extraction rate of each group.

[0023] Figure 2 The antioxidant activity test results of the plant polysaccharides obtained in Example 1;

[0024] In the figure: (a) DPPH free radical scavenging ability; (b) hydroxyl free radical scavenging ability.

[0025] Figure 3 The antioxidant activity test results of the plant polysaccharides obtained in Example 2;

[0026] In the figure: (a) DPPH free radical scavenging ability; (b) hydroxyl free radical scavenging ability.

[0027] Figure 4 The antioxidant activity test results of the plant polysaccharides obtained in Example 3;

[0028] In the figure: (a) DPPH free radical scavenging ability; (b) hydroxyl free radical scavenging ability.

[0029] Figure 5 The antioxidant activity test results of the plant polysaccharides obtained in Example 4;

[0030] In the figure: (a) DPPH free radical scavenging ability; (b) hydroxyl free radical scavenging ability. DETAILED DESCRIPTION

[0031] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0032] Example 1

[0033] A plant polysaccharide, when prepared, comprises the following steps:

[0034] (1) Preparation of edible fungus powder:

[0035] Take fresh and mature Hericium erinaceus and shiitake mushrooms, wash and remove impurities respectively, slice them, dry them at 30°C until the moisture content is about 10%, freeze them at -15°C, put them in a grinder, grind them until the particle size of the obtained edible fungus powder is about 100 meshes, and then mix the Hericium erinaceus powder and shiitake mushroom powder in a ratio of 2:1 to obtain broken wall edible fungus powder.

[0036] (2) Preparation of broken-wall edible fungus powder solution:

[0037] The edible fungus powder was mixed with an L-cysteine ​​solution having a mass concentration of 3 mg / L at a solid-liquid ratio of 1 g:10 mL, and the mixture was shaken and soaked at 60 rpm for 20 min to obtain a wall-broken edible fungus powder solution;

[0038] (3) Enzymatic hydrolysis under the stimulation of micro-DC electric field:

[0039] Select an enzymolysis tank with a diameter of 1m, and after sterilization, pour in the broken wall edible fungus powder solution, and add pectinase and cellulase to the broken wall edible fungus powder solution. With the center point of the enzymolysis tank as the center of the circle, a circle of electrode pairs is arranged about 20cm away from the center of the circle. The distance between two adjacent electrode pairs is about 10cm. Each electrode pair includes a cathode and an anode. The distance between the cathode and the anode is 2cm, and each electrode pair is immersed in the broken wall edible fungus powder solution, and the lower end does not contact the inner wall of the enzymolysis tank. The cathode and the anode are both titanium mesh electrodes. Then, adjust the current density of the micro DC electric field to 0.096mA / cm 2 , pH value is 4.5, the temperature is raised to 40°C, and after enzymatic hydrolysis for 2 hours under the stimulation of a micro-DC electric field, the enzyme is inactivated to obtain a crude plant polysaccharide extract; wherein the mass ratio of pectinase to cellulase is 1:1, and the enzyme addition amount is 2%;

[0040] (4) Purification of crude plant polysaccharide extracts:

[0041] The plant polysaccharide extract is deproteinized by Sevag method, precipitated with 95% ethanol, separated, concentrated and dried to obtain a polysaccharide extract.

[0042] Example 2

[0043] (1) Preparation of edible fungus powder:

[0044] Mix Hericium erinaceus powder and Lentinus edodes powder in a ratio of 3:1 to obtain wall-broken edible fungus powder.

[0045] (2) Preparation of broken-wall edible fungus powder solution:

[0046] The edible fungus powder was mixed with an L-cysteine ​​solution having a mass concentration of 3 mg / L at a solid-liquid ratio of 1 g: 20 mL, and the mixture was shaken and soaked at 120 rpm for 15 min to obtain a wall-broken edible fungus powder solution;

[0047] (3) Enzymatic hydrolysis under the stimulation of micro-DC electric field:

[0048] The current density of the micro DC electric field was adjusted to 0.125 mA / cm 2 , pH value is 4.5, the temperature is raised to 40℃, and after enzymatic hydrolysis for 1.5h under the stimulation of micro-DC electric field, the enzyme is inactivated to obtain the crude extract of plant polysaccharide.

[0049] The rest of the design is the same as in Example 1.

[0050] Example 3

[0051] (1) Preparation of edible fungus powder:

[0052] Mix Hericium erinaceus powder and Lentinus edodes powder in a ratio of 1.5:1 to obtain wall-broken edible fungus powder.

[0053] (2) Preparation of broken-wall edible fungus powder solution:

[0054] The edible fungus powder was mixed with an L-cysteine ​​solution having a mass concentration of 3 mg / L at a solid-liquid ratio of 1 g:15 mL, and the mixture was shaken and soaked at 90 rpm for 18 min to obtain a wall-broken edible fungus powder solution;

[0055] (3) Enzymatic hydrolysis under the stimulation of micro-DC electric field:

[0056] The current density of the micro DC electric field was adjusted to 0.173 mA / cm 2 , pH value is 4.5, the temperature is raised to 40℃, and after enzymatic hydrolysis for 1.6h under the stimulation of micro-DC electric field, the enzyme is inactivated to obtain the crude extract of plant polysaccharide.

[0057] The rest of the design is the same as in Example 1.

[0058] Example 4

[0059] A plant polysaccharide, when prepared, comprises the following steps:

[0060] (1) Preparation of edible fungus powder:

[0061] Take fresh and mature Hericium erinaceus, wash and remove impurities, slice, dry at 30°C until the water content is about 10%, freeze at -15°C, put in a grinder, grind until the particle size of the obtained edible fungus powder is about 100 meshes, and obtain edible fungus powder.

[0062] (2) Preparation of broken-wall edible fungus powder solution:

[0063] The edible fungus powder was mixed with an L-cysteine ​​solution having a mass concentration of 3 mg / L at a solid-liquid ratio of 1 g:15 mL, and the mixture was shaken and soaked at 90 rpm for 18 min to obtain a wall-broken edible fungus powder solution;

[0064] (3) Enzymatic hydrolysis under the stimulation of micro-DC electric field:

[0065] Select an enzymolysis tank with a diameter of 1m, and after sterilization, pour in the broken wall edible fungus powder solution, and add pectinase and cellulase to the broken wall edible fungus powder solution. With the center point of the enzymolysis tank as the center of the circle, a circle of electrode pairs is arranged about 20cm away from the center of the circle. The distance between two adjacent electrode pairs is about 10cm. Each electrode pair includes a cathode and an anode. The distance between the cathode and the anode is 2cm, and each electrode pair is immersed in the broken wall edible fungus powder solution, and the lower end does not contact the inner wall of the enzymolysis tank. The cathode and the anode are both platinum mesh electrodes. Then, adjust the current density of the micro DC electric field to 0.125mA / cm 2, pH value is 4.5, the temperature is raised to 40°C, and after enzymatic hydrolysis for 1.5 hours under the stimulation of a micro-DC electric field, the enzyme is inactivated to obtain a crude plant polysaccharide extract; wherein the mass ratio of pectinase to cellulase is 1:1, and the enzyme addition amount is 2%;

[0066] (4) Purification of crude plant polysaccharide extracts:

[0067] The plant polysaccharide extract is deproteinized by Sevag method, precipitated with 95% ethanol, separated, concentrated and dried to obtain a polysaccharide extract.

[0068] Example 5

[0069] A plant polysaccharide, when prepared, comprises the following steps:

[0070] (1) Preparation of edible fungus powder:

[0071] Take fresh and mature shiitake mushrooms, wash and remove impurities, slice them, dry them at 30°C until the moisture content is about 10%, freeze them at -15°C, put them in a grinder, and grind them until the particle size of the obtained edible fungus powder is about 100 meshes to obtain edible fungus powder.

[0072] (2) Preparation of broken-wall edible fungus powder solution:

[0073] The edible fungus powder was mixed with an L-cysteine ​​solution having a mass concentration of 3 mg / L at a solid-liquid ratio of 1 g:15 mL, and the mixture was shaken and soaked at 90 rpm for 18 min to obtain a wall-broken edible fungus powder solution;

[0074] (3) Enzymatic hydrolysis under the stimulation of micro-DC electric field:

[0075] Select an enzymolysis tank with a diameter of 1m, and after sterilization, pour in the broken wall edible fungus powder solution, and add pectinase and cellulase to the broken wall edible fungus powder solution. With the center point of the enzymolysis tank as the center of the circle, a circle of electrode pairs is arranged about 20cm away from the center of the circle. The distance between two adjacent electrode pairs is about 10cm. Each electrode pair includes a cathode and an anode. The distance between the cathode and the anode is 2cm, and each electrode pair is immersed in the broken wall edible fungus powder solution, and the lower end does not contact the inner wall of the enzymolysis tank. The cathode and the anode are both platinum mesh electrodes. Then, adjust the current density of the micro DC electric field to 0.125mA / cm 2 , pH value is 4.5, the temperature is raised to 40°C, and after enzymatic hydrolysis for 1.5 hours under the stimulation of a micro-DC electric field, the enzyme is inactivated to obtain a crude plant polysaccharide extract; wherein the mass ratio of pectinase to cellulase is 1:1, and the enzyme addition amount is 2%;

[0076] (4) Purification of crude plant polysaccharide extracts:

[0077] The plant polysaccharide extract is deproteinized by Sevag method, precipitated with 95% ethanol, separated, concentrated and dried to obtain a polysaccharide extract.

[0078] Comparative Example 1

[0079] (1) Preparation of edible fungus powder:

[0080] Take fresh and mature Hericium erinaceus and Lentinus edodes, wash and remove impurities respectively, slice them, grind them until the particle size of the obtained edible fungus powder is about 100 meshes, and then mix the Hericium erinaceus powder and Lentinus edodes powder in a ratio of 3:1 to obtain broken wall edible fungus powder.

[0081] The rest of the design is the same as in Example 3.

[0082] Comparative Example 2

[0083] (2) Preparation of broken-wall edible fungus powder solution:

[0084] The edible fungus powder was mixed with deionized water at a solid-liquid ratio of 1 g: 15 mL, and the mixture was shaken at 90 rpm and soaked for 18 min to obtain a wall-broken edible fungus powder solution;

[0085] The rest of the design is the same as in Example 3.

[0086] Comparative Example 3

[0087] (3) Enzymatic hydrolysis:

[0088] A 1m diameter enzymolysis tank was selected, and after sterilization, a broken wall edible fungus powder solution was poured in, and pectinase and cellulase were added to the broken wall edible fungus powder solution, the pH value was adjusted to 4.5, the temperature was raised to 40°C, and after enzymolysis for 1.6h, the enzyme was inactivated to obtain a crude plant polysaccharide extract; wherein the mass ratio of pectinase to cellulase was 1:1, and the enzyme addition amount was 2%;

[0089] The rest of the design is the same as in Example 3.

[0090] Comparative Example 4

[0091] A plant polysaccharide, when prepared, comprises the following steps:

[0092] (1) Preparation of edible fungus powder:

[0093] Take fresh and mature Hericium erinaceus and Lentinus edodes, wash and remove impurities respectively, slice them, grind them until the particle size of the obtained edible fungus powder is about 100 mesh, and then mix the Hericium erinaceus powder and Lentinus edodes powder in a ratio of 1.5:1 to obtain broken wall edible fungus powder.

[0094] (2) Preparation of broken-wall edible fungus powder solution:

[0095] The edible fungus powder was mixed with deionized water at a solid-liquid ratio of 1 g: 15 mL, and the mixture was shaken at 90 rpm and soaked for 18 min to obtain a wall-broken edible fungus powder solution;

[0096] (3) Enzymatic hydrolysis:

[0097] A 1m diameter enzymolysis tank was selected, and after sterilization, a broken wall edible fungus powder solution was poured in, and pectinase and cellulase were added to the broken wall edible fungus powder solution, the pH value was adjusted to 4.5, the temperature was raised to 40°C, and after enzymolysis for 1.6h, the enzyme was inactivated to obtain a crude plant polysaccharide extract; wherein the mass ratio of pectinase to cellulase was 1:1, and the enzyme addition amount was 2%;

[0098] (4) Purification of crude plant polysaccharide extracts:

[0099] The plant polysaccharide extract is deproteinized by Sevag method, precipitated with 95% ethanol, separated, concentrated and dried to obtain a polysaccharide extract.

[0100] The plant polysaccharide extraction rate of each example group and comparative example group was measured

[0101] The phenol-sulfuric acid method was used to detect the plant polysaccharide content, and the plant polysaccharide extraction rate was measured as shown in Table 1 below.

[0102] Table 1:

[0103]

[0104] From Table 1, we can see that:

[0105] 1) The plant polysaccharide extraction rates of Examples 1 to 5 were significantly higher than those of Comparative Example 4. It can be seen that compared with the traditional complex enzyme extraction method, the plant polysaccharide extraction method of the present invention can significantly improve the extraction rates of Hericium erinaceus polysaccharides and Lentinan polysaccharides.

[0106] 2) Compared with Example 3, the plant polysaccharide extraction rate of Comparative Example 1 was reduced by 0.53%. It can be seen that the wall-breaking method of grinding after freezing can improve the extraction rate of plant polysaccharides to a certain extent. The reason may be that the wall-breaking method of grinding after freezing can improve the wall-breaking rate of Hericium erinaceus powder and Lentinus edodes powder, thereby making Hericium erinaceus powder and Lentinus edodes powder better precipitate plant polysaccharides during the subsequent enzymatic hydrolysis process under the stimulation of L-cysteine ​​solution oscillation immersion and micro-DC electric field.

[0107] 3) Compared with Example 3, in Comparative Example 2, the extraction rate of plant polysaccharides was reduced by 1.78% by using deionized water oscillation to treat the edible fungus wall-broken powder. It can be seen that compared with the deionized water oscillation treatment method, the oscillation soaking in L-cysteine ​​solution can significantly improve the extraction rate of plant polysaccharides.

[0108] 4) Compared with Example 3, Comparative Example 3 abandoned the micro-current electric field stimulation during the compound enzyme enzymolysis, and the plant polysaccharide extraction rate was reduced by 7.89%. It can be seen that compared with the traditional compound enzyme enzymolysis method, enzymolysis under the stimulation of a micro-DC electric field can significantly improve the extraction rate of plant polysaccharides;

[0109] 5) Compared with Example 3, Comparative Example 4 adopts the traditional composite enzyme enzymatic hydrolysis method, and the plant polysaccharide extraction rate is reduced by 11.3%. It can be seen that in terms of improving the plant polysaccharide extraction rate, there is a synergistic relationship between the wall-breaking treatment method of grinding after freezing, the oscillating immersion of L-cysteine ​​solution, and the enzymatic hydrolysis under the stimulation of a micro-DC electric field.

[0110] In summary, the present invention firstly improves the wall-breaking rate of Hericium erinaceus powder and Lentinus edodes powder by a wall-breaking treatment method of grinding after freezing, so that Hericium erinaceus powder and Lentinus edodes powder can better precipitate plant polysaccharides during the subsequent enzymatic hydrolysis process under the stimulation of L-cysteine ​​solution oscillation soaking and micro-DC electric field; then, the enzymatic hydrolysis method under the stimulation of micro-DC electric field is adopted in coordination with the oscillation soaking method of L-cysteine ​​solution, thereby significantly improving the extraction rate of plant polysaccharides.

[0111] The antioxidant activity of the plant polysaccharides prepared in Examples 1 to 4 was determined.

[0112] 1) DPPH free radical scavenging ability determination

[0113] Prepare 0.1mmol / L DPPH ethanol solution and store it away from light for later use. Add 2.0mL of plant polysaccharide solution of different concentrations and 2.0mL of DPPH solution to the test tubes, mix well, and react at room temperature away from light for 30 minutes. Measure the absorbance at a wavelength of 517nm, and use distilled water instead of polysaccharide solution as the blank control group. The DPPH free radical scavenging rate is calculated as follows. The results are shown in Figure 2-Figure 5 .

[0114] DPPH free radical scavenging (%) = (A0-A2) / A1×100

[0115] Among them: A2--the absorbance value of plant polysaccharides with different concentrations; A1--the absorbance value of plant polysaccharides replaced by distilled water; A0--the absorbance value of DPPH replaced by distilled water.

[0116] 2) Determination of hydroxyl radical scavenging ability

[0117] 1 mL of 9 mmol / L FeSO4, 1 mL of 9 mmol / L salicylic acid solution, and 1 mL of diluted polysaccharide solution of different concentrations were added to the colorimetric tube in sequence. Deionized water was used instead of the polysaccharide solution as a blank control. 1 mL of hydrogen peroxide with a volume fraction of 0.03% was added. The mixture was kept in a constant temperature water bath at 37°C for 30 minutes. After centrifugation, the absorbance of each reaction solution was measured at 510 nm. The hydroxyl radical scavenging rate was calculated as follows. The results are shown in the table below. Figure 2-Figure 5 .

[0118] Hydroxyl free radical scavenging rate (%) = (1-A1 / A0) × 100

[0119] Among them, A1 is the absorbance value of the polysaccharide group; A0 is the absorbance value of the blank group.

[0120] Depend on Figure 2 It can be seen that the plant polysaccharide prepared in Example 1 of the present invention has excellent DPPH free radical scavenging ability and hydroxyl free radical scavenging ability, and increases with the increase of sample solution concentration, that is, there is a certain dose-effect relationship between the sample solution concentration and the DPPH free radical scavenging ability.

[0121] Depend on Figure 3 It can be seen that the plant polysaccharide prepared in Example 2 of the present invention has excellent DPPH free radical scavenging ability and hydroxyl free radical scavenging ability, and increases with the increase of sample solution concentration, that is, there is a certain dose-effect relationship between the sample solution concentration and the DPPH free radical scavenging ability.

[0122] Depend on Figure 4 It can be seen that the plant polysaccharide prepared in Example 3 of the present invention has excellent DPPH free radical scavenging ability and hydroxyl free radical scavenging ability, and increases with the increase of sample solution concentration, that is, there is a certain dose-effect relationship between the sample solution concentration and the DPPH free radical scavenging ability.

[0123] Depend on Figure 5 It can be seen that the plant polysaccharide prepared in Example 4 of the present invention has excellent DPPH free radical scavenging ability and hydroxyl free radical scavenging ability, and increases with the increase of sample solution concentration, that is, there is a certain dose-effect relationship between the sample solution concentration and the plant polysaccharide.

[0124] It can be seen that the plant polysaccharide prepared by the present invention has excellent antioxidant activity and can be used for the preparation of health products, food and medicine and antioxidant additives thereof.

[0125] At the same time, the DPPH free radical scavenging ability and hydroxyl free radical scavenging ability of the plant polysaccharides prepared in Examples 1 to 3 are better than those in Example 4. The reason may be that under the preparation process of the present invention, Hericium erinaceus polysaccharide and Lentinan polysaccharide produce a synergistic relationship in antioxidant activity when mixed.

[0126] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for extracting plant polysaccharides, characterized in that: The steps include: S1, breaking the wall of edible fungi to obtain broken wall edible fungi powder; S2, mixing the edible fungus powder with the L-cysteine ​​solution at a ratio of 1 g to (10-20) mL to obtain a wall-broken edible fungus powder solution; S3, adding plant complex enzyme to the broken edible fungus powder solution, adjusting the pH value to 4.5, heating to 40° C., and performing enzymolysis for 1.5 to 2 hours under the stimulation of a micro-DC electric field, then inactivating the enzyme to obtain a crude plant polysaccharide extract; S4, removing protein from the plant polysaccharide extract by Sevag method, separating by alcohol precipitation, concentrating and drying to obtain a polysaccharide extract.

2. The method for extracting plant polysaccharides according to claim 1, characterized in that: In step S1, fresh edible fungi are washed, sliced, dried at 30°C to a moisture content of about 10%, frozen at -15°C, placed in a grinder, and ground until the particle size of the obtained edible fungi powder is about 100 meshes, thereby obtaining wall-broken edible fungi powder.

3. The method for extracting plant polysaccharides according to claim 1, characterized in that: In step S2, the mass concentration of the L-cysteine ​​solution is 3 mg / L.

4. The method for extracting plant polysaccharides according to claim 1, characterized in that: In the step S2, the edible fungus powder and the cysteine ​​solution are mixed, and then shaken and soaked at 60 rpm to 120 rpm for 15 to 20 minutes.

5. The method for extracting plant polysaccharides according to claim 1, characterized in that: In step S3, the current density of the micro DC electric field is 0.096 mA / cm 2 ~0.25mA / cm 2 .

6. The method for extracting plant polysaccharides according to claim 1, characterized in that: In step S3, the micro-DC electric field is configured with at least one pair of anode and cathode, and both the cathode and cathode are titanium mesh electrodes or platinum mesh electrodes.

7. The method for extracting plant polysaccharides according to claim 1, characterized in that: In the step S3, the plant complex enzyme includes pectinase and cellulase, and the mass ratio of pectinase to cellulase is 1:

1.

8. The method for extracting plant polysaccharides according to claim 1, characterized in that: The edible fungi are Hericium erinaceus and Lentinula edodes, and the mass ratio of the two in the obtained broken-wall edible fungi powder is 2-3:

1.

9. A plant polysaccharide, characterized in that: The invention comprises lentinan and hericium erinaceus polysaccharide, and is prepared by the extraction method according to any one of claims 1 to 8.

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