Method for extracting soluble ganoderma lucidum polysaccharide by dissolving ganoderma lucidum sporocarp with mixed acid

Abstract

The invention belongs to the technical field of biology, and relates to a method for extracting soluble ganoderan by dissolving ganoderma lucidum sporocarp with mixed acid, which comprises the following steps: adding ganoderma lucidum sporocarp powder into a concentrated phosphoric acid solution, continuously stirring and keeping reaction for 2-3 hours, then slowly adding concentrated sulfuric acid, stirring and keeping reaction for 12-24 hours under temperature control, slowly adding deionized water under the condition of stirring, and continuously stirring and keeping reaction for 2-3 hours under the condition of stirring; and adjusting the pH value of the solution to 5-7, keeping for 12 hours, centrifugally filtering to obtain clear filtrate, filtering, concentrating and drying to obtain the ganoderma lucidum soluble polysaccharide extract. According to the method, the mechanism that concentrated acid and ganoderma lucidum cellulose substances are easily subjected to esterification reaction is utilized, the ganoderma lucidum cell walls are decomposed while being destroyed, the exudation amount of cell contents can be increased, cellulose can be decomposed into soluble polysaccharide, the ganoderma lucidum polysaccharide extraction rate can be greatly increased, and the ganoderma lucidum polysaccharide extraction rate can be greatly increased. The commercial utilization value of lucid ganoderma in the fields of health food, cosmetics and the like is greatly improved.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology and relates to a method for extracting ganoderma lucidum polysaccharide, in particular to a method for extracting soluble ganoderma lucidum polysaccharide by dissolving ganoderma lucidum fruiting bodies with mixed acid. Background Art

[0002] Ganoderma lucidum is the dried fruiting body of Ganoderma lucidum (Leyss. ex Fr.) Karst. or Ganoderma sinense Zhao, Xu et Zhang, a Polyporaceae fungus. It contains polysaccharides, nucleosides, furans, sterols, alkaloids, triterpenes, oils, various amino acids and proteins, enzymes, organic germanium and various trace elements.

[0003] The peptidoglycan in Ganoderma lucidum accounts for about 30% of its dry weight and has the effect of improving immunity. Since peptidoglycan mainly exists in the cell wall of Ganoderma lucidum cells in the form of cellulose, the cell wall needs to be hydrolyzed to extract peptidoglycan and other components. Moreover, the cell wall of Ganoderma lucidum is very tough, which will hinder the release of soluble polysaccharides and other contents in Ganoderma lucidum cells, thereby affecting the extraction of effective ingredients in Ganoderma lucidum fruiting bodies.

[0004] Normally, the amount of water-soluble substances exuded from non-cracked Ganoderma is very small, only 1%, and the efficacy of Ganoderma cannot be fully utilized. Therefore, researchers invented a method for breaking the wall of Ganoderma, which uses high-pressure airflow to crush Ganoderma to break the cell wall, making it easier for the cell contents to seep out. It can effectively increase the amount of soluble substances that leak out by 2-3 times, and improve the utilization rate of Ganoderma's effective ingredients. However, the cell wall of Ganoderma cells is mainly composed of cellulose formed by peptidoglycan, which is very tough and has a low wall-breaking rate. It is impossible to fully extract the effective ingredients of Ganoderma and cannot fully utilize the value of Ganoderma. Summary of the invention

[0005] The purpose of the present invention is to provide a method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid, utilizing the mechanism that concentrated acid easily undergoes esterification reaction with ganoderma cellulose to dissolve ganoderma cellulose and fully release ganoderma soluble substances, then adding alkaline substances for neutralization, separating the acid in the form of precipitates, fully extracting components such as ganoderma soluble polysaccharides, and improving the utilization value of ganoderma.

[0006] The technical principle adopted by the present invention is to utilize the mechanism that concentrated phosphoric acid and concentrated sulfuric acid are easy to react with cellulose substances of ganoderma lucidum to undergo esterification reaction to destroy the cell wall of ganoderma lucidum, thereby dissolving the ganoderma lucidum cells and releasing the soluble components of ganoderma lucidum (mainly soluble ganoderma lucidum polysaccharide). At the same time, the cellulose formed by peptidoglycan is decomposed into soluble polysaccharide, thereby improving the extraction rate of soluble components of ganoderma lucidum. Then, the alkaline substance calcium hydroxide is used for neutralization, and phosphoric acid and sulfuric acid are precipitated with calcium to separate the acid. During the reaction process, the temperature of the reaction solution is controlled in a relatively low temperature range, thereby improving the extraction rate of soluble components of ganoderma lucidum and avoiding the destruction of effective components of ganoderma lucidum.

[0007] The technical solution adopted by the present invention is:

[0008] A method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid, the steps of which are as follows:

[0009] Step S1: Ganoderma lucidum fruiting bodies are crushed and sieved to obtain Ganoderma lucidum fruiting body powder with a mesh size of not less than 30.

[0010] Step S2: taking a concentrated phosphoric acid solution at a mass ratio of 1 to 1.5:1 between the concentrated phosphoric acid solution and the Ganoderma lucidum fruiting body powder; adding the Ganoderma lucidum fruiting body powder into the concentrated phosphoric acid solution, and keeping the reaction for 2 to 3 hours while stirring continuously, and controlling the temperature below 10° C. during the reaction process.

[0011] Step S3: slowly add concentrated sulfuric acid to the reaction solution, the amount of concentrated sulfuric acid added is 10-15% of the amount of concentrated phosphoric acid, quickly stir evenly, keep the reaction for 12-24 hours, and control the temperature below 10°C during the reaction process to prevent coking.

[0012] Step S4: deionized water is slowly added under stirring, and the amount of deionized water added is 8 to 12 times the amount of concentrated phosphoric acid used. When the solution temperature exceeds 50°C, stop adding water, and continue adding water after the temperature drops below 40°C. After adding water, keep warm at 45 to 50°C for 2 hours.

[0013] Step S5: When the pH value of the solution is adjusted to 5-7 and maintained for 12 hours, the solution is centrifuged and filtered to obtain a clear filtrate, which is the Ganoderma lucidum water extract.

[0014] Preferably, in step S1, the water content of the Ganoderma lucidum fruiting body powder is less than 9%.

[0015] Preferably, in step S2, the concentrated phosphoric acid solution has a concentration of 60-70%, and is cooled to -5°C in a 10% sodium chloride brine bath and kept warm.

[0016] Preferably, in step S2, the temperature is controlled by adding dry ice to cool the reaction solution when the temperature exceeds 10°C.

[0017] Preferably, in step S3, the concentration of concentrated sulfuric acid is above 90%.

[0018] Preferably, in step S3, the temperature is controlled by adding dry ice to cool the reaction solution when the temperature exceeds 10°C.

[0019] Preferably, in step S5, the pH value of the solution is adjusted by adding calcium hydroxide powder into the solution and stirring evenly.

[0020] Preferably, in step S5, the Ganoderma lucidum water extract is concentrated under reduced pressure and dried to form a dry paste.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention utilizes the mechanism that concentrated acid can easily react with cellulose substances in Ganoderma lucidum to undergo esterification reaction, thereby destroying the cell wall of Ganoderma lucidum and decomposing the cell wall at the same time. This can not only increase the amount of exudation of cell contents, but also decompose the cellulose into soluble polysaccharides, thereby significantly increasing the traditional Ganoderma lucidum polysaccharide extraction rate from 3-4% to 12-15%, greatly improving the commercial utilization value of Ganoderma lucidum in the fields of health food, cosmetics, etc.

[0023] (2) During the acid addition process, the solution is kept at a low temperature, below 10°C, to avoid strong dehydration of the concentrated acid causing the material to char; during the water dilution process, the temperature is kept at no more than 50°C to avoid excessive hydrolysis and inactivation of polysaccharides caused by high temperature under acidic conditions.

[0024] (3) First, the powder is soaked with weakly esterified concentrated phosphoric acid, and then a small amount of concentrated sulfuric acid is added to promote esterification and dissolution of the Ganoderma lucidum powder. This overcomes the problem of low phosphate dissolution, excessive dehydration of concentrated sulfuric acid leading to charring of the Ganoderma lucidum powder, and darkening of the solution color. The small amount of concentrated sulfuric acid used reduces the heat generated during dilution and neutralization, and also ensures production safety. At the same time, the effect of concentrated sulfuric acid easily esterifying and dissolving Ganoderma lucidum is achieved.

[0025] (4) Using a low-temperature salt water bath and adding dry ice to cool the reaction process helps avoid high temperatures and coking during the material addition process.

[0026] (5) After the reaction solution is diluted, the solution temperature is further increased to 45-50°C and maintained for 2-3 hours to facilitate the release of more soluble polysaccharides. DETAILED DESCRIPTION

[0027] The following examples are used to further describe the specific embodiments of the present invention. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. The experimental methods in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available, with analytically pure reagents being preferred reagents.

[0028] Example 1

[0029] (1) Prepare 250 mL of 65% phosphoric acid aqueous solution, add it to the reaction vessel, keep stirring, cool it to -5°C in a 10% sodium chloride brine bath and keep it warm (the outer wall of the container uses 10% sodium chloride solution as the coolant, and the coolant is output and refluxed by a chiller. The temperature of the coolant output by the chiller is controlled to -5°C).

[0030] (2) Ganoderma lucidum fruiting body was crushed and passed through a 50-mesh sieve, and 200 g of sieved powder was taken.

[0031] (3) Add the Ganoderma lucidum fruiting body powder to the concentrated phosphoric acid solution and stir continuously. When the solution is heated to 10°C, immediately add 20g of dry ice and stir evenly. Add 60g of dry ice three times. After the addition is complete, keep the reaction for 2.5h. Slowly add 25mL of 90% concentrated sulfuric acid (addition takes 30min). During this period, whenever the reaction solution heats up by more than 10°C, add 15g of dry ice each time, for a total of 5 times. After the addition is complete and the temperature is stabilized below 0°C, keep the reaction for 12h.

[0032] (4) While stirring, slowly and evenly add 2500mL of clean water, which takes a total of 20 minutes. During the water addition, the temperature is kept below 50℃ (stop adding water when the solution temperature exceeds 50℃, and continue adding water after cooling down to below 40℃). After adding water, raise the temperature to 50℃ and keep it warm for 2 hours. Take 120g of calcium hydroxide powder and add it to the solution (3 times, add 40g each time, and the interval between each addition is 15 minutes). After the addition is completed, keep stirring for 12 hours, and the pH value is detected to be 5.7, which meets the requirements. Then filter with a sedimentation centrifuge, the separation factor is greater than 600, and 2173mL of filtrate is obtained. The filtrate is reduced to 0.02MPa at 90℃ in a vacuum drying oven and dried for 24 hours to obtain 34.75g of light brown dry paste, which is then ground into powder.

[0033] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia and was 26.3 g, with a yield of 13.15%.

[0034] Example 2

[0035] (1) Prepare 300 mL of 60% phosphoric acid aqueous solution, add it to the reaction vessel, keep stirring, cool it to -5°C in a 10% sodium chloride brine bath and keep it warm (the outer wall of the container uses 10% sodium chloride solution as the coolant, and the coolant is output and refluxed by the chiller. The temperature of the coolant output from the chiller is controlled to -5°C).

[0036] (2) Ganoderma lucidum fruiting body was crushed and passed through a 50-mesh sieve, and 300 g of sieved powder was taken.

[0037] (3) Add the Ganoderma lucidum fruiting body powder to the concentrated phosphoric acid solution and stir continuously. When the solution is heated to 10°C, immediately add 30 g of dry ice and stir evenly. Add 90 g of dry ice three times. After the addition is complete, keep the reaction for 3.0 hours. Slowly add 35 mL of 93% concentrated sulfuric acid (addition takes 30 minutes). During this period, whenever the reaction solution heats up by more than 10°C, add 20 g of dry ice each time, for a total of 5 times. After the addition is complete and the temperature is stabilized below 0°C, keep the reaction for 16 hours.

[0038] (4) While stirring, slowly and evenly add 3500mL of clean water, which takes a total of 30 minutes. During the water addition, the temperature is kept below 50℃ (stop adding water when the solution temperature exceeds 50℃, and continue adding water after cooling down to below 40℃). After adding water, raise the temperature to 50℃ and keep it warm for 2h. Take 180g of calcium hydroxide powder and add it to the solution (4 times, 45g each time, and the interval between each addition is 15min). After the addition is completed, keep stirring for 12h, and the pH value is detected to be 6.2, which meets the requirements. Then filter with a sedimentation centrifuge, the separation factor is greater than 600, and 3368mL of filtrate is obtained. The filtrate is reduced to 0.02MPa at 90℃ in a vacuum drying oven and dried for 24h to obtain 45.39g of light brown dry paste, which is then ground into powder.

[0039] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia and was 36.5 g, with a yield of 12.16%.

[0040] Example 3

[0041] (1) Prepare 250 mL of 70% phosphoric acid aqueous solution, add it to the reaction vessel, keep stirring, cool it to -5°C in a 10% sodium chloride brine bath and keep it warm (the outer wall of the container uses 10% sodium chloride solution as the coolant, and the coolant is output and refluxed by the chiller. The temperature of the coolant output from the chiller is controlled to -5°C).

[0042] (2) Ganoderma lucidum fruiting bodies were crushed and passed through a 50-mesh sieve, and 180 g of the sieved powder was taken.

[0043] (3) Add the Ganoderma lucidum fruiting body powder to the concentrated phosphoric acid solution and stir continuously. When the solution is heated to 10°C, immediately add 20 g of dry ice and stir evenly. Add 60 g of dry ice three times. After the addition is complete, keep the reaction for 2.0 h. Slowly add 32 mL of 95% concentrated sulfuric acid (add over 30 min). During this period, whenever the reaction solution heats up by more than 10°C, add 15 g of dry ice each time, for a total of 5 times. After the addition is complete and the temperature is stabilized below 0°C, keep the reaction for 22 h.

[0044] (4) While stirring, slowly and evenly add 2500mL of clean water, which takes a total of 20 minutes. During the water addition, the temperature is kept below 50℃ (stop adding water when the solution temperature exceeds 50℃, and continue adding water after cooling down to below 40℃). After adding water, raise the temperature to 50℃ and keep it warm for 2 hours. Take 150g of calcium hydroxide powder and add it to the solution (3 times, 50g each time, and the interval between each addition is 15 minutes). After the addition is completed, keep stirring for 12 hours, and the pH value is detected to be 6.5, which meets the requirements. Then filter with a sedimentation centrifuge, the separation factor is greater than 600, and 2382mL of filtrate is obtained. The filtrate is reduced to 0.02MPa at 90℃ in a vacuum drying oven and dried for 24 hours to obtain 31.56g of light brown dry paste, which is then ground into powder.

[0045] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia and was 24.7 g, with a yield of 13.72%.

[0046] Comparative Example 1

[0047] The process is the same as in Example 1, and the concentration of the phosphoric acid solution is 50%.

[0048] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2253.5 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 21.03 g of a light brown dry paste, which was then ground into powder.

[0049] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 13.6 g, which was 6.8%, a decrease of 48.3% compared with Example 1.

[0050] Comparative Example 2

[0051] The process is the same as in Example 1, and the concentration of the phosphoric acid solution is 80%.

[0052] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600, and 2203 mL of filtrate was obtained. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 60.47 g of a burnt black dry paste, which was then ground into powder.

[0053] The polysaccharide content in the dry powder was detected by high performance liquid chromatography (HPLC) according to Part I of the Chinese Pharmacopoeia, and the yield was 1.15%, which was significantly reduced by 91.3% compared with Example 1, and the burnt black color did not meet the use requirements.

[0054] Comparative Example 3

[0055] The process is the same as in Example 1, except that the concentrated phosphoric acid solution is 180 mL, the Ganoderma lucidum fruiting body powder is 200 g (mass ratio is 0.9:1), and the concentration of concentrated sulfuric acid is 65%.

[0056] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2155 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C to 0.02 MPa for 24 h to obtain 34.75 g of a light brown dry paste, which was then ground into powder.

[0057] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 12.8 g, which was 6.4%, a decrease of 51.3% compared with Example 1.

[0058] Comparative Example 4

[0059] The process is the same as in Example 1, except that the concentrated phosphoric acid solution is 350 mL, the Ganoderma lucidum fruiting body powder is 200 g (mass ratio is 1.75:1), and the concentration of concentrated sulfuric acid is 65%.

[0060] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2106 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 66.54 g of a light brown dry paste, which was then ground into powder.

[0061] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 7.3%, which was 44.9% lower than that in Example 1.

[0062] Comparative Example 5

[0063] The process is the same as in Example 1. During the addition of Ganoderma lucidum fruiting body powder, the solution temperature rises to 30° C. in a short time.

[0064] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2223 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 50.05 g of a light black dry paste, which was then ground into powder.

[0065] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 8.7%, which was 34.2% lower than that in Example 1.

[0066] Comparative Example 6

[0067] The process is the same as in Example 1, and the concentration of concentrated sulfuric acid is 50%.

[0068] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2191 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 11.74 g of a light brown dry paste, which was then ground into powder.

[0069] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 8.4 g, which was 4.2%, a decrease of 68.0% compared with Example 1.

[0070] Comparative Example 7

[0071] The process is the same as in Example 1, except that concentrated sulfuric acid is not added during the process.

[0072] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2189 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 4.53 g of a light brown dry paste, which was then ground into powder.

[0073] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 3.1 g, which was 1.6%, 88.2% lower than that in Example 1.

[0074] Comparative Example 8

[0075] The process is the same as in Example 1, and the reaction is maintained for 8 hours (less than 12 hours) after the addition of concentrated sulfuric acid.

[0076] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2200 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C to 0.02 MPa for 24 h to obtain 21.13 g of a light brown dry paste, which was then ground into powder.

[0077] The polysaccharide content in the dry powder was detected by high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 8.7%, which was 33.8% lower than that in Example 1.

[0078] Comparative Example 9

[0079] The process is the same as in Example 1, and the reaction is maintained for 36 hours (greater than 24 hours) after the addition of concentrated sulfuric acid.

[0080] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2196 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 118.6 g of a light brown dry paste, which was then ground into powder.

[0081] The polysaccharide content in the dry powder was detected by high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 3.3%, which was 75.3% lower than that in Example 1.

[0082] Comparative Example 10

[0083] The process is the same as in Example 1, except that sodium hydroxide (not strong calcium oxide) is used to adjust the pH value.

[0084] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2260 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 1325.4 g of light-colored dry crystalline particles.

[0085] The polysaccharide content in the dry powder was 27.2 g according to the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 13.6%, which was 3.4% higher than that in Example 1. However, there were a large number of soluble trisodium phosphate crystals, and the soluble polysaccharide accounted for only 2.1% of the product, which caused difficulties in subsequent separation.

[0086] Comparative Example 11

[0087] The process is the same as in Example 1. After adding clean water for dilution, the temperature is raised to 30°C and kept warm for 2 hours.

[0088] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2122 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 27.56 g of a light brown dry paste, which was then ground into powder.

[0089] The polysaccharide content in the dry powder was detected by the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 10.4%, which was 21.3% lower than that in Example 1.

[0090] Comparative Example 12

[0091] The process is the same as in Example 1. After adding clean water for dilution, the temperature is raised to 60° C. and kept warm for 2 h.

[0092] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2122 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 55.9 g of a light brown dry paste, which was then ground into powder.

[0093] The polysaccharide content in the dry powder was detected by high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 10.6%, which was 19.4% lower than that in Example 1.

[0094] Comparative Example 13

[0095] The process is the same as in Example 1, except that no dry ice is added to cool the solution during the process of adding the Ganoderma lucidum fruiting body powder to the concentrated phosphoric acid solution.

[0096] The reaction solution was filtered through a sedimentation centrifuge with a separation factor greater than 600 to obtain 2105 mL of filtrate. The filtrate was dried in a vacuum oven at 90°C under reduced pressure to 0.02 MPa for 24 h to obtain 40.05 g of a concentrated black dry paste, which was then ground into powder.

[0097] The polysaccharide content in the dry powder was 19.6 g according to the high performance liquid chromatography (HPLC) method provided in Part I of the Chinese Pharmacopoeia, and the yield was 9.8%, which was 25.5% lower than that in Example 1. However, the color was burnt black and did not meet the use requirements.

[0098] The invention treats ganoderma lucidum fruiting body powder with concentrated phosphoric acid and concentrated sulfuric acid in succession under controlled temperature conditions, neutralizes the reaction solution with calcium hydroxide, obtains ganoderma lucidum soluble polysaccharide extract through filtering, concentrating and drying, and compared with the traditional water extraction method, the amount of soluble polysaccharide obtained is increased by more than 300%, thereby significantly improving the economic benefits of ganoderma lucidum.

[0099] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid, characterized in that: The steps are as follows: Step S1: crushing and sieving the Ganoderma lucidum fruiting body to obtain Ganoderma lucidum fruiting body powder with a mesh size of not less than 30; Step S2: taking a concentrated phosphoric acid solution at a mass ratio of 1 to 1.5:1 between the concentrated phosphoric acid solution and the Ganoderma lucidum fruiting body powder; adding the Ganoderma lucidum fruiting body powder to the concentrated phosphoric acid solution, and keeping the reaction for 2 to 3 hours while continuously stirring, and controlling the temperature below 10° C. during the reaction process; Step S3: slowly add concentrated sulfuric acid to the reaction solution, the amount of concentrated sulfuric acid added is 10-15% of the amount of concentrated phosphoric acid, quickly stir evenly, keep the reaction for 12-24 hours, and control the temperature below 10°C during the reaction process to prevent coking; Step S4: deionized water is slowly added under stirring, and the amount of deionized water added is 8 to 12 times the amount of concentrated phosphoric acid used. When the solution temperature exceeds 50°C, stop adding water, and continue adding water after the temperature drops to below 40°C. After the water addition is completed, keep the temperature at 45 to 50°C for 2 hours; Step S5: When the pH value of the solution is adjusted to 5-7 and maintained for 12 hours, the solution is centrifuged and filtered to obtain a clear filtrate, which is the Ganoderma lucidum water extract.

2. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In the step S1, the water content of the Ganoderma lucidum fruiting body powder is less than 9%.

3. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In step S2, the concentration of the concentrated phosphoric acid solution is 60-70%, and the solution is cooled to -5°C in a 10% sodium chloride salt water bath and kept warm.

4. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In step S2, the temperature is controlled by adding dry ice to cool the reaction solution when the temperature exceeds 10°C.

5. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In step S3, the concentration of the concentrated sulfuric acid is above 90%.

6. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In step S3, the temperature is controlled by adding dry ice to cool the reaction solution when the temperature exceeds 10°C.

7. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In step S5, the pH value of the solution is adjusted by adding calcium hydroxide powder into the solution and stirring it evenly.

8. The method for extracting soluble ganoderma polysaccharides by dissolving ganoderma fruiting bodies with mixed acid according to claim 1, characterized in that: In the step S5, the Ganoderma lucidum water extract is concentrated and dried under reduced pressure to form a dry paste.