A preparation method for improving the biological activity of Grifola frondosa polysaccharide and its product

Abstract

The invention provides a preparation method for improving the biological activity of Grifola frondosa polysaccharide and a product thereof. The preparation method comprises the following steps: (1) crushing dried Grifola frondosa fruiting bodies to obtain Grifola frondosa fruiting body crushed material; adding ethanol to soak, filtering and vacuum drying; (2) subjecting the crushed material to nitrogen explosion treatment; (3) adding water to soak, then heating to 45-50 DEG C, stirring and ultrasonically treating, filtering, and collecting filtrate; (4) subjecting the filtrate to reduced pressure concentration treatment at 45-50 DEG C to obtain a concentrated solution; (5) adding ethanol to perform alcohol precipitation; centrifugal treatment, removing the supernatant to obtain a precipitate, washing; and vacuum freeze drying to obtain Grifola frondosa polysaccharide. The raw materials used in the invention are simple, and the prepared Grifola frondosa polysaccharide has high biological activity and a high extraction rate.

Description

Technical Field

[0001] The invention relates to the technical field of maitake mushroom polysaccharide, and in particular to a preparation method for improving the biological activity of maitake mushroom polysaccharide and a product thereof. Background Art

[0002] Grifola frondosa is a medicinal and edible fungus belonging to the Basidiomycetes, Polyporaceae, and Polyporaceae families. Grifola frondosa contains a rich variety of bioactive components, including polysaccharides, flavonoids, polyphenols, proteins, ergosterol, and fungal SOD enzymes. Grifola frondosa polysaccharides, in particular, possess high medicinal value, including anti-tumor, immune-enhancing, blood sugar-lowering, antioxidant, and free radical scavenging properties.

[0003] Currently, the extraction temperature and solvent used in the extraction of Grifola frondosa polysaccharides significantly influence the physical and chemical properties of the extracted polysaccharides. To improve the extraction rate of Grifola frondosa polysaccharides, water is typically used as the solvent and the extraction is performed at temperatures above 80°C. However, higher extraction temperatures can cause irreversible changes in the higher-order structure of the macromolecular active substances, thereby affecting their biological activity.

[0004] Domestic patent application number CN202111358748.5 discloses a method for improving the extraction rate and bioactivity of Grifola frondosa polysaccharides. The method comprises the following steps: adding hydrogen peroxide and ascorbic acid to a solution of Grifola frondosa powder and deionized water for reaction; concentrating the resulting reaction solution, adding anhydrous ethanol, and re-dissolving the resulting precipitate in deionized water to obtain a crude polysaccharide solution; freeze-drying the resulting crude polysaccharide solution to obtain Grifola frondosa degraded crude polysaccharides. The Grifola frondosa degraded crude polysaccharides obtained in this invention exhibit high in vitro antioxidant activity. However, this method requires the reaction system containing Grifola frondosa powder to be stirred at 95-105°C for 3±0.5 hours. This high temperature inevitably affects the activity of the Grifola frondosa polysaccharides. Furthermore, the addition of substances such as ascorbic acid may increase the impurities in the resulting Grifola frondosa polysaccharides. Summary of the Invention

[0005] The object of the present invention is to provide a preparation method for improving the biological activity of Grifola frondosa polysaccharide and a product thereof. The raw materials used are simple, the prepared Grifola frondosa polysaccharide has high biological activity and a high extraction rate.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0008] (1) Grinding the dried fruiting bodies of Grifola frondosa to obtain a ground material of Grifola frondosa fruiting bodies; then adding ethanol to the ground material of Grifola frondosa fruiting bodies for soaking, filtering and vacuum drying;

[0009] (2) subjecting the crushed material obtained in step (1) to nitrogen blasting treatment;

[0010] (3) Soaking the crushed material obtained in step (2) in water, heating it to 45-50°C, performing ultrasonic treatment while stirring, and then filtering to collect the filtrate;

[0011] (4) Concentrating the filtrate under reduced pressure at 45-50° C. to obtain a concentrated solution;

[0012] (5) adding ethanol to the concentrated solution for alcohol precipitation; then centrifuging the solution and removing the supernatant to obtain a precipitate, which is then washed with ethanol; and vacuum freeze-drying the precipitate after washing with ethanol to obtain Grifola frondosa polysaccharide.

[0013] Preferably, in step (1), the dried Grifola frondosa fruiting bodies are obtained by naturally drying fresh Grifola frondosa fruiting bodies; or the dried Grifola frondosa fruiting bodies are prepared by the following method: fresh Grifola frondosa fruiting bodies are first frozen at -15~-10°C for 2~3 hours, and then vacuum dried at 45~50°C for 2~3 hours; then cooled to room temperature, and then frozen at -15~-10°C for 2~3 hours, and then vacuum dried at 45~50°C to constant weight.

[0014] Further preferably, the dried Grifola frondosa fruiting body is prepared by the following method: fresh Grifola frondosa fruiting body is first frozen at -15~-10°C for 2~3 hours, then vacuum dried at 45~50°C for 2~3 hours; then cooled to room temperature, then frozen at -15~-10°C for 2~3 hours, and then vacuum dried at 45~50°C to constant weight.

[0015] Preferably, in step (1), the particle size of the ground Grifola frondosa fruiting body is 5-20 mesh.

[0016] Preferably, in step (1), the mass ratio of the ground Grifola frondosa fruiting body to ethanol is 1:5-6; the mass fraction of the ethanol is above 95%, and the soaking time is 5-8 hours;

[0017] The vacuum drying temperature is below 50°C.

[0018] Preferably, in step (2), during the nitrogen explosion treatment, the temperature is 40-50°C, the pressure is 10-50 Ma, and the pressure is maintained for 2-5 minutes.

[0019] Preferably, in step (2), the nitrogen explosion treatment is repeated 2 to 3 times.

[0020] Preferably, step (3) specifically includes the following steps: adding 20 to 25 times the mass of pure water to the crushed material obtained in step (2), soaking for 1 to 1.5 hours, then heating to 45 to 50°C, stirring and ultrasonically treating for 3.5 to 4.5 hours at an ultrasonic power of 200 to 300 W; then filtering and collecting the filtrate.

[0021] Preferably, in step (4), the volume of the concentrated liquid is 25-30% of the volume of the filtrate; and the vacuum degree during the reduced pressure concentration treatment is below 20 mbar.

[0022] Preferably, in step (5), adding ethanol to the concentrated solution for alcohol precipitation specifically comprises the following steps: adding ethanol to the concentrated solution until the volume fraction of ethanol in the obtained liquid reaches 75-80%, and then placing the solution in an environment of 15-20°C for 18-24 hours;

[0023] The precipitate was washed with ethanol 3 to 4 times.

[0024] As a general inventive concept, the present invention provides a product prepared by the above-mentioned method for improving the biological activity of Grifola frondosa polysaccharide.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention first degreases the ground maitake mushroom fruiting bodies with ethanol, then dries them and performs a nitrogen blasting treatment. The nitrogen blasting treatment further pulverizes the ground maitake mushroom fruiting bodies and destroys their fiber and cell structures, making polysaccharides more easily extractable, thereby increasing the extraction rate of maitake mushroom polysaccharides. Furthermore, after the blasting treatment, the biological activity of the obtained maitake mushroom polysaccharide was significantly improved, which may be due to the high pressure acting on the polysaccharide molecules during the blasting process, causing some structural changes in the polysaccharide, thereby enhancing the biological activity.

[0027] The present invention performs degreasing treatment before nitrogen explosion treatment, which is more conducive to improving the biological activity of maitake mushroom polysaccharide than performing degreasing treatment after nitrogen explosion treatment.

[0028] 2. When the crushed material obtained after the nitrogen explosion treatment of the present invention is used to extract polysaccharides using pure water, it only needs to control the temperature at 45-50°C, combined with stirring and ultrasonic treatment, so that the maitake mushroom polysaccharide can be effectively extracted. Combined with subsequent low-temperature reduced pressure concentration, alcohol precipitation and other processes, maitake mushroom polysaccharide with high biological activity and high extraction rate (crude maitake mushroom polysaccharide) can be obtained.

[0029] 3. The present invention subjects fresh Grifola frondosa fruiting bodies to the steps of freezing, vacuum drying, freezing, and vacuum drying to constant weight, so that the tissue of the obtained Grifola frondosa fruiting bodies becomes looser, which can achieve better degreasing effect and increase the yield of Grifola frondosa polysaccharide. Compared with Grifola frondosa fruiting bodies obtained by natural drying, the obtained Grifola frondosa polysaccharide has higher biological activity. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] Example 1:

[0032] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0033] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -12°C for 2.5 h, then vacuum dried at 47°C for 3 h; then cooled to room temperature, frozen at -12°C for 2.5 h, and then vacuum dried at 47°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0034] (2) The dried Grifola frondosa fruiting bodies were crushed to obtain Grifola frondosa fruiting body crushed material with a particle size of 5-20 mesh; 96% ethanol by mass was added to the Grifola frondosa fruiting body crushed material and soaked for 8 h, then filtered and vacuum dried at 47 °C; the mass ratio of Grifola frondosa fruiting body crushed material to ethanol was 1:5.

[0035] (3) The crushed material obtained in step (2) is subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature is 45°C, the pressure is 30Ma, and the pressure is maintained for 3 minutes; the nitrogen blasting treatment is repeated twice.

[0036] (4) Add 20 times the mass of pure water to the crushed material obtained in step (3), soak for 1.5 hours, then heat to 45°C, and perform ultrasonic treatment for 4 hours while stirring at an ultrasonic power of 200W; then filter and collect the filtrate.

[0037] (5) The filtrate is concentrated under reduced pressure at 50°C to obtain a concentrated solution; the volume of the concentrated solution is 28% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0038] (6) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 75%, and then the solution was placed in an environment of 18°C ​​for 20 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed three times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide (Grifola frondosa crude polysaccharide).

[0039] Example 2:

[0040] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0041] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -15°C for 2 h, then vacuum dried at 50°C for 2.5 h; then cooled to room temperature, frozen at -15°C for 2 h, and then vacuum dried at 50°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0042] (2) The dried Grifola frondosa fruiting bodies were crushed to obtain Grifola frondosa fruiting body crushed material with a particle size of 5-20 mesh; 96% ethanol by mass was added to the Grifola frondosa fruiting body crushed material and soaked for 7 h, then filtered and vacuum dried at 50°C; the mass ratio of Grifola frondosa fruiting body crushed material to ethanol was 1:6.

[0043] (3) The crushed material obtained in step (2) is subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature is 48°C, the pressure is 20Ma, and the pressure is maintained for 4 minutes; the nitrogen blasting treatment is repeated twice.

[0044] (4) Add 25 times the mass of pure water to the crushed material obtained in step (3), soak for 1 hour, then heat to 50°C, and perform ultrasonic treatment for 3.5 hours while stirring at an ultrasonic power of 300W; then filter and collect the filtrate.

[0045] (5) The filtrate is concentrated under reduced pressure at 48°C to obtain a concentrated solution; the volume of the concentrated solution is 25% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0046] (6) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 78%, and then the solution was placed in an environment of 15°C for 18 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed three times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0047] Example 3:

[0048] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0049] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -15°C for 2 h, then vacuum dried at 45°C for 2 h; then cooled to room temperature, frozen at -15°C for 2 h, and then vacuum dried at 45°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0050] (2) The dried fruiting bodies of the maitake mushroom were crushed to obtain a maitake mushroom fruiting body crushed material with a particle size of 5 to 20 mesh; 96% ethanol by mass was added to the maitake mushroom fruiting body crushed material and soaked for 8 h, then filtered and vacuum-dried at 45°C; the mass ratio of the maitake mushroom fruiting body crushed material to ethanol was 1:5.

[0051] (3) The crushed material obtained in step (2) was subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature was 40°C, the pressure was 50Ma, and the pressure was maintained for 2 minutes; the nitrogen blasting treatment was repeated 3 times.

[0052] (4) Add 25 times the mass of pure water to the crushed material obtained in step (3), soak for 1.5 hours, then heat to 45°C, and perform ultrasonic treatment for 3.5 hours while stirring at an ultrasonic power of 300W; then filter and collect the filtrate.

[0053] (5) The filtrate is concentrated under reduced pressure at 50°C to obtain a concentrated solution; the volume of the concentrated solution is 30% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0054] (6) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 80%, and then the solution was placed in an environment of 20°C for 24 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed four times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0055] Example 4:

[0056] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0057] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -10°C for 3 h, and then vacuum dried at 48°C for 3 h; then cooled to room temperature, frozen at -10°C for 3 h, and then vacuum dried at 48°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0058] (2) The dried Grifola frondosa fruiting bodies were crushed to obtain Grifola frondosa fruiting body crushed material with a particle size of 5-20 mesh; 96% ethanol by mass was added to the Grifola frondosa fruiting body crushed material and soaked for 5 h, then filtered and vacuum dried at 45 °C; the mass ratio of Grifola frondosa fruiting body crushed material to ethanol was 1:5.5.

[0059] (3) The crushed material obtained in step (2) is subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature is 45°C, the pressure is 10Ma, and the pressure is maintained for 2 minutes; the nitrogen blasting treatment is repeated twice.

[0060] (4) Add 22 times the mass of pure water to the crushed material obtained in step (3), soak for 1 hour, then heat to 45°C, and perform ultrasonic treatment for 4 hours while stirring at an ultrasonic power of 200W; then filter and collect the filtrate.

[0061] (5) The filtrate is concentrated under reduced pressure at 48°C to obtain a concentrated solution; the volume of the concentrated solution is 26% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0062] (6) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 75%, and then the solution was placed in an environment of 18°C ​​for 20 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed four times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0063] Example 5:

[0064] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0065] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -12°C for 3 h, then vacuum dried at 50°C for 2 h; then cooled to room temperature, frozen at -12°C for 3 h, and then vacuum dried at 50°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0066] (2) The dried fruiting bodies of the maitake mushroom were crushed to obtain a maitake mushroom fruiting body crushed material with a particle size of 5 to 20 meshes; 96% ethanol by mass was added to the maitake mushroom fruiting body crushed material and soaked for 6 h, then filtered and vacuum-dried at 50°C; the mass ratio of the maitake mushroom fruiting body crushed material to ethanol was 1:6.

[0067] (3) The crushed material obtained in step (2) was subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature was 50°C, the pressure was 15Ma, and the pressure was maintained for 5 minutes; the nitrogen blasting treatment was repeated 3 times.

[0068] (4) Add 25 times the mass of pure water to the crushed material obtained in step (3), soak for 1.5 hours, then heat to 48°C, and perform ultrasonic treatment for 4.5 hours while stirring at an ultrasonic power of 300W; then filter and collect the filtrate.

[0069] (5) The filtrate is concentrated under reduced pressure at 45°C to obtain a concentrated solution; the volume of the concentrated solution is 25% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0070] (6) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 78%, and then the solution was placed in an environment of 15°C for 20 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed three times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0071] Example 6:

[0072] A preparation method for improving the biological activity of Grifola frondosa polysaccharide comprises the following steps:

[0073] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -10°C for 3 h, then vacuum dried at 50°C for 2 h; then cooled to room temperature, frozen at -10°C for 3 h, and then vacuum dried at 50°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0074] (2) The dried fruiting bodies of the maitake mushroom were crushed to obtain a maitake mushroom fruiting body crushed material with a particle size of 5 to 20 meshes; 96% ethanol by mass was added to the maitake mushroom fruiting body crushed material and soaked for 6 h, then filtered and vacuum-dried at 50°C; the mass ratio of the maitake mushroom fruiting body crushed material to ethanol was 1:5.5.

[0075] (3) The crushed material obtained in step (2) was subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature was 42° C., the pressure was 35 Ma, and the pressure was maintained for 3 minutes; the nitrogen blasting treatment was repeated twice.

[0076] (4) Add 25 times the mass of pure water to the crushed material obtained in step (3), soak for 1 hour, then heat to 47°C, and perform ultrasonic treatment for 4 hours while stirring at an ultrasonic power of 300W; then filter and collect the filtrate.

[0077] (5) The filtrate is concentrated under reduced pressure at 50°C to obtain a concentrated solution; the volume of the concentrated solution is 27% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0078] (6) Add ethanol to the concentrated solution until the volume fraction of ethanol in the obtained liquid reaches 77%, and then place it in an environment of 15°C for 18 hours; then centrifuge it, remove the supernatant, and obtain a precipitate, which is washed with ethanol 3 to 4 times; the precipitate after washing with ethanol is vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0079] Example 7:

[0080] The difference from Example 1 is that in step (1), the dried Grifola frondosa fruiting bodies are obtained by natural drying of fresh Grifola frondosa fruiting bodies. The other steps are the same as those in Example 1.

[0081] Example 8:

[0082] The difference from Example 2 is that in step (1), the dried Grifola frondosa fruiting bodies are obtained by natural drying of fresh Grifola frondosa fruiting bodies. The other steps are the same as those in Example 2.

[0083] Comparative Example 1:

[0084] A method for preparing Grifola frondosa polysaccharide comprises the following steps:

[0085] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -12°C for 2.5 h, then vacuum dried at 47°C for 3 h; then cooled to room temperature, frozen at -12°C for 2.5 h, and then vacuum dried at 47°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0086] (2) The dried Grifola frondosa fruiting bodies were crushed to obtain Grifola frondosa fruiting body crushed material with a particle size of 5-20 mesh; 96% ethanol by mass was added to the Grifola frondosa fruiting body crushed material and soaked for 8 h, then filtered and vacuum dried at 47 °C; the mass ratio of Grifola frondosa fruiting body crushed material to ethanol was 1:5.

[0087] (3) Add 20 times the mass of pure water to the crushed material obtained in step (2), soak for 1.5 hours, then heat to 45°C, and perform ultrasonic treatment for 4 hours while stirring at an ultrasonic power of 200W; then filter and collect the filtrate.

[0088] (4) The filtrate is concentrated under reduced pressure at 50°C to obtain a concentrated solution; the volume of the concentrated solution is 28% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0089] (5) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 75%, and then the solution was placed in an environment of 18°C ​​for 20 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed three times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0090] Comparative Example 2:

[0091] A method for preparing Grifola frondosa polysaccharide comprises the following steps:

[0092] (1) Naturally drying fresh Grifola frondosa fruiting bodies to obtain dried Grifola frondosa fruiting bodies.

[0093] (2) The dried Grifola frondosa fruiting bodies were crushed to obtain Grifola frondosa fruiting body crushed material with a particle size of 5-20 mesh; 96% ethanol by mass was added to the Grifola frondosa fruiting body crushed material and soaked for 8 h, then filtered and vacuum dried at 47 °C; the mass ratio of Grifola frondosa fruiting body crushed material to ethanol was 1:5.

[0094] (3) Add 20 times the mass of pure water to the crushed material obtained in step (2), soak for 1.5 hours, then heat to 45°C, and perform ultrasonic treatment for 4 hours while stirring at an ultrasonic power of 200W; then filter and collect the filtrate.

[0095] (4) The filtrate is concentrated under reduced pressure at 50°C to obtain a concentrated solution; the volume of the concentrated solution is 28% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0096] (5) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 75%, and then the solution was placed in an environment of 18°C ​​for 20 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed three times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0097] Comparative Example 3:

[0098] A method for preparing Grifola frondosa polysaccharide comprises the following steps:

[0099] (1) The fresh fruiting bodies of Grifola frondosa were first frozen at -12°C for 2.5 h, then vacuum dried at 47°C for 3 h; then cooled to room temperature, frozen at -12°C for 2.5 h, and then vacuum dried at 47°C to constant weight to obtain dried Grifola frondosa fruiting bodies.

[0100] (2) The dried Grifola frondosa fruiting bodies were crushed to obtain Grifola frondosa fruiting body crushed material with a particle size of 5-20 mesh; 96% ethanol by mass was added to the Grifola frondosa fruiting body crushed material and soaked for 8 h, then filtered and vacuum dried at 47 °C; the mass ratio of Grifola frondosa fruiting body crushed material to ethanol was 1:5.

[0101] (3) Add 20 times the mass of pure water to the crushed material obtained in step (2), soak for 1.5 hours, then heat to 45°C, and perform ultrasonic treatment for 4 hours while stirring at an ultrasonic power of 200W; then filter and collect the filtrate.

[0102] (4) The crushed material obtained in step (3) was subjected to nitrogen blasting treatment; during the nitrogen blasting treatment, the temperature was 45°C, the pressure was 30Ma, and the pressure was maintained for 3 minutes; the nitrogen blasting treatment was repeated twice.

[0103] (5) The filtrate is concentrated under reduced pressure at 50°C to obtain a concentrated solution; the volume of the concentrated solution is 28% of the volume of the filtrate; the vacuum degree during the reduced pressure concentration process is below 20 mbar.

[0104] (6) Ethanol was added to the concentrated solution until the volume fraction of ethanol in the obtained liquid reached 75%, and then the solution was placed in an environment of 18°C ​​for 20 hours; the solution was then centrifuged and the supernatant was removed to obtain a precipitate, which was washed three times with ethanol; the precipitate after washing with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

[0105] The yield of the Grifola frondosa polysaccharide obtained by the methods of Examples 1 to 8 and Comparative Examples 1 to 3 was calculated as follows: yield = Grifola frondosa polysaccharide mass / dry fruiting body mass × 100%; and the Grifola frondosa polysaccharide was prepared into an aqueous solution with a concentration of 800 mg / L, and then the superoxide anion radical ( The yield of Grifola frondosa polysaccharide and the above-mentioned biological activity test results are shown in Table 1.

[0106] Table 1 Yield and bioactivity test results of Grifola frondosa polysaccharide

[0107]

[0108] As shown in Table 1, the Grifola frondosa polysaccharides (crude Grifola frondosa polysaccharides) prepared by the preparation methods of Examples 1-8 of the present invention have high biological activity and a high overall yield. Furthermore, a comparison of Examples 1-2 and Examples 7-8 shows that the dried Grifola frondosa fruiting bodies prepared using the methods of Examples 1-2 can improve both the yield and biological activity of Grifola frondosa polysaccharides compared to dried Grifola frondosa fruiting bodies obtained by natural drying. A comparison of Example 1 and Comparative Example 1, and Example 7 and Comparative Example 2, shows that nitrogen blasting significantly improves the yield and biological activity of Grifola frondosa polysaccharides. A comparison of Example 1 and Comparative Example 3 shows that defatting before nitrogen blasting improves the biological activity of Grifola frondosa polysaccharides compared to defatting after nitrogen blasting.

[0109] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for improving the biological activity of Grifola frondosa polysaccharide, characterized in that: The following steps are involved: (1) grinding the dried Grifola frondosa fruiting bodies to obtain a Grifola frondosa fruiting body crushed material; then adding ethanol to the Grifola frondosa fruiting body crushed material for soaking, then filtering and vacuum drying; The dried Grifola frondosa fruiting body is prepared by the following method: fresh Grifola frondosa fruiting body is first frozen at -15 to -10°C for 2 to 3 hours, then vacuum dried at 45 to 50°C for 2 to 3 hours; then cooled to room temperature, then frozen at -15 to -10°C for 2 to 3 hours, and then vacuum dried at 45 to 50°C to constant weight; (2) subjecting the crushed material obtained in step (1) to nitrogen explosion treatment; During the nitrogen blasting treatment, the temperature is 40-50°C, the pressure is 10-50Ma, and the pressure is maintained for 2-5 minutes; The nitrogen explosion treatment is repeated 2 to 3 times; (3) Soaking the crushed material obtained in step (2) in water, heating it to 45-50° C., performing ultrasonic treatment while stirring, and then filtering to collect the filtrate; (4) Concentrating the filtrate under reduced pressure at 45-50° C. to obtain a concentrated solution; (5) adding ethanol to the concentrated solution for alcohol precipitation; then centrifuging the concentrated solution to remove the supernatant to obtain a precipitate, and washing the precipitate with ethanol; The precipitate washed with ethanol was vacuum freeze-dried to obtain Grifola frondosa polysaccharide.

2. The method for preparing Grifola frondosa polysaccharide for improving its biological activity according to claim 1, characterized in that: In step (1), the particle size of the pulverized material of Grifola frondosa fruiting bodies is 5-20 meshes.

3. The method for preparing Grifola frondosa polysaccharide for improving its biological activity according to claim 1, characterized in that: In step (1), the mass ratio of the pulverized material of Grifola frondosa fruiting bodies to ethanol is 1:5-6; the mass fraction of the ethanol is above 95%, and the soaking time is 5-8 hours; The vacuum drying temperature is below 50°C.

4. The method for preparing Grifola frondosa polysaccharide for improving its biological activity according to claim 1, characterized in that: Step (3) specifically comprises the following steps: adding 20 to 25 times the mass of pure water to the crushed material obtained in step (2), soaking for 1 to 1.5 hours, then heating to 45 to 50° C., stirring and ultrasonically treating for 3.5 to 4.5 hours at an ultrasonic power of 200 to 300 W; then filtering and collecting the filtrate.

5. The method for preparing Grifola frondosa polysaccharide for improving its biological activity according to claim 1, characterized in that: In step (4), the volume of the concentrated liquid is 25-30% of the volume of the filtrate; and the vacuum degree during the reduced pressure concentration treatment is below 20 mbar.

6. The method for preparing Grifola frondosa polysaccharide for improving its biological activity according to claim 1, characterized in that: In step (5), adding ethanol to the concentrated solution for alcohol precipitation specifically comprises the following steps: adding ethanol to the concentrated solution until the volume fraction of ethanol in the obtained feed solution reaches 75-80%, and then placing the solution in an environment of 15-20° C. for 18-24 hours; The precipitate is washed with ethanol 3 to 4 times.

7. A product prepared by the method for improving the biological activity of Grifola frondosa polysaccharide according to any one of claims 1 to 6.

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