A yeast glucan and its preparation method

Abstract

The present invention belongs to the technical field of yeast glucan, and specifically relates to a yeast glucan and a preparation method thereof. Among them, the preparation method of the yeast glucan includes: Step 1: adding a first solvent to the yeast raw material; Step 2: adding an alkali reagent to the solution obtained in Step 1 to carry out an extraction reaction; Step 3: separating the reaction solution obtained in Step 2 to obtain a solid-phase degreased cell wall; Step 4: adding a second solvent to the solid-phase degreased cell wall obtained in Step 3 to prepare a cell wall emulsion for reaction; Step 5: adding an acid reagent to the reaction solution obtained in Step 4 to carry out an extraction reaction; Step 6: separating the reaction solution obtained in Step 5, collecting the heavy phase, and obtaining a yeast glucan product. The preparation method of the yeast glucan of the present invention shortens the conventional preparation process flow, greatly alleviates the environmental protection treatment pressure, effectively reduces the production cost, and the prepared yeast glucan has a higher purity and better industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of yeast glucan, and particularly relates to a yeast glucan and a preparation method thereof. Background Art

[0002] Yeast β-glucan, also known as dextran, is a functional polysaccharide existing in the inner layer of the yeast cell wall. The finished product is in the form of a light yellow or yellowish-brown powder; the molecular weight of β-glucan is about 20,000 - 4,000,000 D, and its basic composition structure is mainly composed of a β-1,3-D-glucan main chain and a 1,6-D-glucan side chain. In recent years, people have conducted in-depth research on the efficacy, molecular mechanism, and application of yeast β-glucan, and found that β-glucan has good biological activity. Especially through its immunomodulatory effect, it has a good effect on preventing upper respiratory tract infections. Clinical studies have also confirmed its effect on preventing upper respiratory tract infections. Therefore, β-glucan has been developed as a health food with significant functions.

[0003] Currently, the production method of yeast glucan is a combined method of acid-base treatment and enzyme treatment. Chinese Patent CN101570769A discloses a yeast glucan, mannan and a production method thereof. Using the cell wall of baker's yeast or brewing yeast as raw material, after treatment with alkaline protease and mannanase, the light phase and the heavy phase are separated; then the heavy phase is configured into a 1% - 10% solution, and after alkali treatment, separation, acid treatment and separation, finally the obtained heavy phase is spray-dried at 100 - 180 °C, and more than 70% of yeast glucan can be obtained after treatment.

[0004] Chinese Patent CN101560269A discloses a preparation method of β-1,3-glucan. Using the main by-product of the beer brewing industry, beer residue, as raw material, through α-amylase treatment, α-glucose is hydrolyzed, and then extracted with alkali solution twice continuously. After separation, the insoluble matter is defatted and dehydrated with 1.5 - 20 times of organic solvent, so as to obtain yeast β-1,3-glucan with a purity as high as 80%. Summary of the Invention

[0005] The technical problem to be solved by the present invention: In the prior art, the preparation process of yeast β-glucan is complicated, requires high equipment requirements, has great environmental protection treatment pressure, high manufacturing cost, and the glucan produced has a low purity.

[0006] In view of the above technical problems, the present invention provides a yeast glucan and a preparation method thereof.

[0007] Specifically, the present invention provides the following technical solutions:

[0008] In the first aspect, the present invention provides a preparation method of yeast glucan, comprising the following steps:

[0009] Step 1: Add a first solvent to the yeast raw material;

[0010] Step 2: Add an alkali reagent to the solution obtained in Step 1 and carry out an extraction reaction;

[0011] Step 3: Separate the reaction solution obtained in Step 2 to obtain a solid-phase defatted cell wall;

[0012] Step 4: Add a second solvent to the solid-phase defatted cell wall obtained in Step 3 to prepare a cell wall emulsion and carry out a reaction;

[0013] Step 5: Add an acid reagent to the reaction solution obtained in Step 4 and carry out an extraction reaction;

[0014] Step 6: Separate the reaction solution obtained in Step 5, collect the heavy phase, and obtain a yeast glucan product.

[0015] Preferably, in Step 1, the yeast raw material includes dry yeast and / or yeast cell wall.

[0016] Preferably, in Step 1, the first solvent is an organic solvent.

[0017] Preferably, in Step 1, the first solvent is an alcohol solvent containing C 1-4 of.

[0018] More preferably, in Step 1, the first solvent includes one or more of methanol, ethanol, n-propanol, isopropanol, and n-butanol.

[0019] Further preferably, in Step 1, the mass of the first solvent is 5 to 15 times the mass of the yeast raw material.

[0020] Preferably, in Step 2, the alkali reagent includes one or two of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, and sodium methoxide.

[0021] Preferably, in Step 2, the mass of the alkali reagent is 5 to 12% of the mass of the yeast raw material.

[0022] Preferably, in Step 2, the mass of the alkali reagent is 5 to 11% of the mass of the yeast raw material.

[0023] Preferably, in Step 2, the extraction temperature is 70 to 100 °C.

[0024] Preferably, in Step 2, the extraction temperature is 70 to 85 °C.

[0025] Preferably, in Step 2, the extraction time is 2 to 8 h.

[0026] Preferably, in Step 2, the extraction time is 3 to 5 h.

[0027] Preferably, in step 4, the second solvent is water.

[0028] Preferably, in step 4, the temperature of the water is 95 - 100 °C.

[0029] More preferably, in step 4, the mass percentage of dry matter in the cell wall milk is 10% - 15%.

[0030] Preferably, in step 4, the temperature of the reaction is maintained at 95 - 100 °C.

[0031] Preferably, in step 4, the reaction time is 0.15 - 5 h.

[0032] Preferably, in step 4, the reaction time is 1 - 5 h.

[0033] Preferably, in step 5, first cool the solution after the reaction in step 4, then add a third solvent for dilution, and finally add an acid reagent for extraction reaction.

[0034] Preferably, in step 5, cool the solution after the reaction in step 4 to 50 - 75 °C.

[0035] Preferably, in step 5, cool the solution after the reaction in step 4 to 60 - 75 °C.

[0036] Preferably, in step 5, the third solvent is water.

[0037] Preferably, in step 5, the mass percentage of dry matter in the diluted solution is 5% - 17%.

[0038] Preferably, in step 5, mix for 0.1 - 5 h after dilution.

[0039] Preferably, in step 5, the acid reagent is selected from one or more of hydrochloric acid, sulfuric acid, and citric acid.

[0040] Preferably, in step 5, adjust the suspension obtained in step 4 to pH 4 - 6 with the acid reagent.

[0041] Preferably, in step 5, the extraction temperature is 50 - 100 °C.

[0042] Preferably, in step 5, the extraction temperature is 70 - 100 °C.

[0043] Preferably, in step 5, the extraction time is 0.5 - 8 h.

[0044] Preferably, in step 7, the drying is selected from spray drying, freeze drying, or vacuum drying.

[0045] Preferably, in step 7, the drying is spray drying, the inlet air temperature is 100-180°C, and the outlet air temperature is 60-90°C.

[0046] In a second aspect, the present invention provides a yeast glucan, and the yeast glucan product is prepared by the preparation method of the yeast glucan.

[0047] Preferably, the purity of the yeast glucan is ≥62%.

[0048] Preferably, the purity of the yeast glucan is 62%-91%.

[0049] More preferably, the purity of the yeast glucan is 79%-91%.

[0050] Even more preferably, the purity of the yeast glucan is 82%-91%.

[0051] Advantages of the present invention

[0052] (1) Using yeast cell wall and / or dry yeast as raw materials, adding an alkali reagent to a lower alcohol solvent to hydrolyze and remove lipophilic impurities, and dispersing and dissolving the lipophilic impurities in the lower alcohol solvent. This operation can replace the three steps of enzymatic hydrolysis, saponification in an aqueous system, and solvent treatment in the traditional process, shortening the process flow.

[0053] (2) In the preparation method of the present invention, only conventional separation equipment is needed to easily achieve solid-liquid separation of materials; the solvent can be recycled and reused, and the amount of alkali waste liquid generated is greatly reduced, greatly alleviating the environmental protection treatment pressure and effectively reducing production costs.

[0054] (3) First, a lower alcohol organic solvent and an alkali reagent are used to act on the yeast raw material to obtain a defatted yeast cell wall, then water is added to prepare a yeast cell wall emulsion for heat preservation reaction, followed by acid extraction, and finally the obtained yeast glucan has a higher purity, up to 90.3%. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a process flow chart of the preparation of yeast glucan of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0056] As described above, the present invention provides a yeast glucan and a preparation method thereof.

[0057] In the present invention, the first object is to provide a preparation method of yeast glucan, including the following steps:

[0058] (1) Adding a first solvent to the yeast raw material, and the mass of the first solvent is 5-15 times the mass of the yeast raw material;

[0059] (2) Add an alkali reagent for extraction, extract at a temperature of 70 - 100 °C for 2 - 8 h, and the mass of the alkali reagent is 5 - 12% of the mass of the yeast raw material;

[0060] (3) Filter and separate to obtain the solid-phase defatted cell wall, and concentrate the filtrate under reduced pressure to recover the solvent;

[0061] (4) Add water to the solid-phase defatted cell wall to prepare a cell wall emulsion, the temperature of the water is 95 - 100 °C, stir evenly to obtain a suspension, and continue to react at 95 - 100 °C for 0.15 - 5 h;

[0062] (5) Cool to 50 - 75 °C, add water for dilution to make the mass percentage of dry matter 5% - 17%, mix evenly; then add an acid reagent, adjust the pH to about 4 - 6, and stir at a temperature of 50 - 100 °C for about 0.5 - 8 h;

[0063] (6) Then perform solid-liquid separation to obtain a wet solid, and spray dry to obtain a yeast glucan product.

[0064] Preferably, in step 1, the yeast raw material includes dry yeast and / or yeast cell wall, and the yeast used in the dry yeast and / or yeast cell wall is selected from one or more of Saccharomyces cerevisiae, Candida sp., Torulopsis sp., Rhodotorula sp., and Cryptococcus sp.

[0065] Preferably, in step 1, the first solvent is an alcohol solvent containing C 1-4 of.

[0066] More preferably, the volume percentage of alcohol in the organic solvent is 60% - 100%.

[0067] Even more preferably, the volume percentage of alcohol in the organic solvent is 70% - 100%; the first solvent is a solution containing a lower alcohol with 1 - 4 carbon atoms. Steps (1) and (2) are saponification reactions, and the lower alcohol solution promotes the mutual solubility of the oil and the alkali reagent, making it a homogeneous system to accelerate the progress of the saponification reaction.

[0068] Preferably, the solid-phase defatted cell wall obtained in step (3) includes components such as glucan, mannan, and protein.

[0069] Preferably, the mass of the first solvent is 6 - 10 times the mass of the yeast raw material.

[0070] Preferably, the mass of the alkali reagent is 8% - 11% of the mass of the yeast raw material.

[0071] Preferably, in step 2, the extraction temperature is 75 - 85 °C.

[0072] Preferably, in step 4, the mass percentage of dry matter in the cell wall emulsion is 11% - 14%.

[0073] Preferably, in step 4, the reaction time is 3 to 5 h.

[0074] Preferably, in step 5, the mass percentage of dry matter in the diluted solution is 5% to 7%.

[0075] Unless otherwise specified, all kinds of reagents / instruments used in the examples and comparative examples of the present invention are conventional commercially available products. The sources of the experimental materials and instruments used in the present invention are shown in the following table:

[0076] Table 1 Experimental materials / instruments and manufacturers

[0077]

[0078] To better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific examples.

[0079] Example 1

[0080] (1) Preparation of yeast β-glucan

[0081] Step 1: Add 500 g of absolute ethanol to 100 g of dry yeast;

[0082] Step 2: Then add 5 g of sodium ethoxide, stir, heat up to 80 °C, and keep stirring for 3 hours;

[0083] Step 3: After filtration and separation, obtain the solid-phase degreased cell wall, and concentrate the filtrate under reduced pressure to recover ethanol;

[0084] Step 4: Add 450 mL of water (the temperature of the water is 95 °C) to the solid-phase degreased cell wall to prepare a cell wall emulsion, wherein the mass percentage of dry matter is 10%, mix evenly, and keep stirring at 95 °C for 3 hours;

[0085] Step 5: After the temperature drops to 70 °C, add water for dilution to make the mass percentage of dry matter 5%, stir for 0.5 h, and mix evenly. Add concentrated sulfuric acid, adjust the pH to about 5.5, and heat up to 75 °C and keep stirring for 1 hour;

[0086] Step 6: Centrifuge at 8000 r / min for 10 min, wash the separated heavy phase to neutral, collect the heavy phase, place the heavy phase in a spray drying tower, inlet air temperature: 180 °C, outlet air temperature 80 °C, and the solid obtained after drying is β-glucan. Its purity is detected by liquid chromatography to be 83.91%, and the yield is 39.01%.

[0087] (2) Detection of yeast β-glucan

[0088] Preparation of sample solution: Accurately weigh 0.4 g (accurate to 0.0002 g) of the sample and place it into a 25 mL stoppered glass test tube. Accurately add 6.0 mL of hydrochloric acid (37%). After tightly capping the test tube, mix it with a vortex mixer to obtain a uniform suspension. Place the test tube in a water bath at 30 °C for 45 minutes, and shake and mix it with a vortex mixer every 15 minutes. Transfer all the suspension to a 250 mL hydrolysis flask, wash the test tube several times with 100 - 120 mL of water, and incorporate the washing solution into the hydrolysis flask. Treat it at 121 °C for 60 minutes. After hydrolysis is completed, cool it to room temperature in a water bath or an ice bath. Add 9 mL of sodium hydroxide solution to adjust the pH of the solution to 6 - 7, transfer it to a 200 mL volumetric flask, add water to the scale for volume fixation, and filter it with a 0.45 μm pore size cellulose acetate membrane for standby. After acid treatment of the sample, test it under the specified chromatographic conditions, and calculate the result by external standard method.

[0089] The chromatographic conditions are as follows:

[0090] Chromatographic column: Aminex HPX - 87H ion Exclusion (7.8 mm × 300 mm BIO - RAD 1);

[0091] Mobile phase: 0.005 mol / L sulfuric acid solution. Use a 1 mL graduated pipette to suck 0.55 mL of concentrated sulfuric acid into a 5 L beaker, add 2 L of water, and stir evenly;

[0092] Flow rate: 0.6 mL / min;

[0093] Column temperature: 65 °C;

[0094] Injection volume: 20 μL.

[0095] Calculation formula for the content w of β - glucan (also known as the purity of β - glucan): In terms of mass fraction, the value is expressed in %, and is calculated according to the following formula:

[0096]

[0097] In the formula: w - the content of β - glucan in the sample, %; A - the concentration of glucose calculated from the standard curve corresponding to the peak area of 20 μL of the sample solution, with the unit of milligram per liter (mg / L); m - the mass of the weighed sample, with the unit of gram (g); 0.2 - the volume of the sample after treatment for volume fixation, with the unit of liter; 0.9 - the coefficient for converting glucose to β - glucan; F - the empirical compensation coefficient for the low result caused by the destruction of glucose in the acid hydrolysis of the sample, which is 1.14.

[0098] Example 2

[0099] Step 1: Add 800 g of 90% ethanol (by volume percentage) to 100 g of yeast cell wall;

[0100] Step 2: Add another 10 g of potassium hydroxide, stir and heat up to 80 °C, and keep stirring for 3 hours;

[0101] Step 3: Through filtration and separation, a solid-phase defatted cell wall is obtained. In addition, the filtrate is concentrated under reduced pressure to recover ethanol;

[0102] Step 4: Add 400 mL of water (the temperature of the water is 95 °C) to the solid-phase defatted cell wall, where the mass percentage of dry matter is 12.5%, mix evenly and keep warm at 95 °C for 5 hours;

[0103] Step 5: After the temperature drops to 65 °C, add water for dilution to make the mass percentage of dry matter 6.25%, stir and mix for 0.5 hour. Add hydrochloric acid, adjust the pH to about 4, and heat up to 70 °C and keep stirring for 1 hour;

[0104] Step 6: Centrifuge at a speed of 8000 rpm for 10 min. Wash the separated heavy phase to neutral, collect the heavy phase, place the heavy phase in a spray drying tower, with the inlet air temperature of 180 °C and the outlet air temperature of 90 °C. The solid obtained after drying is β-glucan. The detection method is the same as that in Example 1. After detection, the purity of β-glucan is 90.30% and the yield is 36.06%.

[0105] Example 3

[0106] Step 1: Add 1500 g of 90% methanol (volume percentage) to 100 g of yeast cell wall;

[0107] Step 2: Add another 10 g of potassium hydroxide, heat up to 70 °C with stirring, and keep stirring for 5 hours;

[0108] Step 3: Through filtration and separation, a solid-phase cell wall is obtained. In addition, the filtrate is concentrated under reduced pressure to recover methanol;

[0109] Step 4: Add 550 mL of water (the temperature of the water is 95 °C) to the solid phase to prepare a cell wall emulsion, where the mass percentage of dry matter is 15%, mix evenly and keep stirring at 95 °C for 1 hour;

[0110] Step 5: After the temperature drops to 60 °C, add water for dilution to make the mass percentage of dry matter 7.5%, stir and mix for 0.5 hour. Add citric acid, adjust the pH to about 4.5, and heat up to 70 °C and keep stirring for 1 hour;

[0111] Step 6: Centrifugal separation was carried out at a speed of 5000 rpm for 30 min. The heavy phase obtained by separation was washed with water until neutral, and the heavy phase was collected. The heavy phase was placed in a spray drying tower, with an inlet air temperature of 120 °C and an outlet air temperature of 75 °C. The solid obtained after drying was β-glucan. The detection method was the same as that in Example 1. After detection, the purity of β-glucan was 82.90% and the yield was 34.20%.

[0112] Example 4

[0113] Step 1: Add 800 g of 90% isopropanol (volume percentage) to 100 g of yeast cell wall;

[0114] Step 2: Then add 12 g of potassium hydroxide, and raise the temperature to 90 °C with stirring, and keep stirring for 2 hours;

[0115] Step 3: After filtration and separation, the solid phase cell wall was obtained, and the filtrate was concentrated under reduced pressure to recover isopropanol;

[0116] Step 4: Add 350 mL of water (the temperature of the water is 95 °C) to the solid phase, where the mass percentage of dry matter is 12.5%, mix evenly and keep stirring at 95 °C for 5 hours;

[0117] Step 5: After the temperature drops to 70 °C, add water to dilute to make the mass percentage of dry matter 6.25%, and stir and mix for 0.5 hour. Add hydrochloric acid to adjust the pH to about 5.2, and keep stirring at 70 °C for 1 hour;

[0118] Step 6: Centrifugal separation was carried out at a speed of 7000 rpm for 20 min. The heavy phase obtained by separation was washed with water until neutral, and the heavy phase was collected. The heavy phase was placed in a spray drying tower, with an inlet air temperature of 180 °C and an outlet air temperature of 80 °C. The solid obtained after drying was β-glucan. The detection method was the same as that in Example 1. After detection, the purity of β-glucan was 79.33%. The yield was 34.39%.

[0119] Example 5

[0120] Step 1: Add 800 g of 90% isopropanol (volume percentage) to 100 g of yeast cell wall;

[0121] Step 2: Then add 12 g of potassium hydroxide, and raise the temperature to 90 °C with stirring, and keep stirring for 2 hours;

[0122] Step 3: After filtration and separation, the solid phase cell wall was obtained, and in addition, the filtrate was concentrated under reduced pressure to recover isopropanol;

[0123] Step 4: Add 350 mL of water (the temperature of the water is 95 °C) to the solid phase, where the mass percentage of dry matter is 12.5%, mix evenly and keep stirring at 95 °C for 5 hours;

[0124] Step 5: After the temperature drops to 50°C, add water for dilution to make the dry matter mass percentage 6.25%, and stir and mix for 0.5 hour. Add hydrochloric acid to adjust the pH to about 4, and maintain the temperature at 50°C with stirring for 1 hour;

[0125] Step 6: Centrifuge at 8000 rpm for 10 minutes. Wash the separated heavy phase to neutrality, collect the heavy phase, place the heavy phase in a spray drying tower, with an inlet air temperature of 180°C and an outlet air temperature of 90°C. The solid obtained after drying is β-glucan. The detection method is the same as in Example 1. After detection, the purity of β-glucan is 69.33% and the yield is 37.12%.

[0126] Example 6

[0127] Step 1: Add 800 g of acetonitrile to 100 g of yeast cell wall;

[0128] Step 2: Then add 12 g of potassium hydroxide, heat up to 90°C with stirring, and maintain the temperature with stirring for 2 hours;

[0129] Step 3: Separate by filtration to obtain the solid cell wall. In addition, concentrate the filtrate under reduced pressure to recover acetonitrile;

[0130] Step 4: Add 350 mL of water (the temperature of the water is 100°C) to the solid phase, where the dry matter mass percentage is 12.5%, mix evenly and maintain the temperature at 100°C with stirring for 3 hours;

[0131] Step 5: After the temperature drops to 60°C, add water for dilution to make the dry matter mass percentage 6.25%, and stir and mix for 0.5 hour. Add hydrochloric acid to adjust the pH to about 5, and heat up to 70°C with stirring for 1 hour;

[0132] Step 6: Centrifuge at 8000 rpm for 10 minutes. Wash the separated heavy phase to neutrality, collect the heavy phase, place the heavy phase in a spray drying tower, with an inlet air temperature of 150°C and an outlet air temperature of 75°C. The solid obtained after drying is β-glucan. The detection method is the same as in Example 1. After detection, the purity of β-glucan is 62.8% and the yield is 41.39%.

[0133] Comparative Example 1

[0134] Step 1: Add 450 mL of water to 50 g of yeast cell wall to control the dry matter at about 10%, and mix evenly;

[0135] Step 2: Add 11.28 g of sodium hydroxide, heat up to 90°C with stirring, and maintain the temperature with stirring for 3 hours;

[0136] Step 3: Separate by filtration to obtain the solid phase;

[0137] Step 4: Add water for dilution to make the mass percentage of dry solid matter 5%, and maintain stirring and mixing at 70 °C for 0.5 hour. Add sulfuric acid solution, adjust the pH to about 5.2, and raise the temperature to 95 °C for heat preservation and stirring for 1 hour;

[0138] Step 5: Centrifuge at a speed of 8000 rpm for 10 min. Wash the separated heavy phase until it is neutral, collect the heavy phase, place the heavy phase in a spray drying tower, with the inlet air temperature of 180 °C and the outlet air temperature of 80 °C. The obtained solid after drying is β-glucan. The detection method is the same as that in Example 1. After detection, the purity of β-glucan is 52.8% and the yield is 45.6%.

[0139] Although the specific implementation manners of the present invention are described above, it does not limit the protection scope of the present invention. Based on the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. A preparation method of yeast glucan, characterized in that, It includes the following steps: Step 1: Add a first solvent to the yeast raw material, and the first solvent is an alcohol solvent containing C 1-4 ; Step 2: Add an alkali reagent to the solution obtained in Step 1 for an extraction reaction; Step 3: Separate the reaction solution obtained in Step 2 to obtain a solid-phase defatted cell wall; Step 4: Add a second solvent to the solid-phase defatted cell wall obtained in Step 3 to prepare a cell wall emulsion for reaction. The second solvent is water, and the temperature of the reaction is maintained at 95 - 100 °C; Step 5: Add an acid reagent to the reaction solution obtained in Step 4 for an extraction reaction; Step 6: Separate the reaction solution obtained in Step 5, collect the heavy phase, and obtain a yeast glucan product.

2. The preparation method of yeast glucan according to claim 1, wherein, In Step 1, the yeast raw material includes dry yeast and / or yeast cell wall.

3. The preparation method of yeast glucan according to claim 1, wherein, In Step 1, the first solvent includes one or more of methanol, ethanol, n-propanol, isopropanol, and n-butanol.

4. The preparation method of yeast glucan according to claim 2, wherein, In Step 1, the first solvent includes one or more of methanol, ethanol, n-propanol, isopropanol, and n-butanol.

5. The preparation method of yeast glucan according to claim 1, wherein, In Step 1, the mass of the first solvent is 5 - 15 times the mass of the yeast raw material.

6. The preparation method of yeast glucan according to claim 3, wherein, In Step 1, the mass of the first solvent is 5 - 15 times the mass of the yeast raw material.

7. The preparation method of yeast glucan according to claim 1, wherein, In Step 2, the alkali reagent includes one or two of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, and sodium methoxide.

8. The preparation method of yeast glucan according to claim 2, wherein, In Step 2, the alkali reagent includes one or two of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, and sodium methoxide.

9. The preparation method of yeast glucan according to claim 3, wherein, In Step 2, the alkali reagent includes one or two of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, and sodium methoxide.

10. The preparation method of yeast glucan according to claim 5, wherein, In Step 2, the alkali reagent includes one or two of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, and sodium methoxide.

11. The preparation method of yeast glucan according to claim 1, wherein, In Step 2, the mass of the alkali reagent is 5% - 12% of the mass of the yeast raw material.

12. The preparation method of yeast glucan according to claim 7, wherein, In Step 2, the mass of the alkali reagent is 5% - 12% of the mass of the yeast raw material.

13. The preparation method of yeast glucan according to claim 1, wherein, In Step 2, the mass of the alkali reagent is 5% - 11% of the mass of the yeast raw material.

14. The method for preparing yeast glucan according to claim 1, wherein, In Step 2, the extraction temperature is 70 - 100 °C; and / or the extraction time is 2 - 8 h.

15. The preparation method of yeast glucan according to claim 2, wherein, In Step 2, the extraction temperature is 70 - 100 °C; and / or the extraction time is 2 - 8 h.

16. The preparation method of yeast glucan according to claim 3, wherein, In Step 2, the extraction temperature is 70 - 100 °C; and / or the extraction time is 2 - 8 h.

17. The preparation method of yeast glucan according to claim 5, wherein, In Step 2, the extraction temperature is 70 - 100 °C; and / or the extraction time is 2 - 8 h.

18. The preparation method of yeast glucan according to claim 7, wherein, In Step 2, the extraction temperature is 70 - 100 °C; and / or the extraction time is 2 - 8 h.

19. The preparation method of yeast glucan according to claim 11, wherein, In Step 2, the extraction temperature is 70 - 100 °C; and / or the extraction time is 2 - 8 h.

20. The preparation method of yeast glucan according to claim 1, wherein, In Step 2, the extraction temperature is 70 - 85 °C; and / or the extraction time is 3 - 5 h.

21. The preparation method of yeast glucan according to any one of claims 1-20, wherein, In Step 4, the temperature of the water is 95 - 100 °C.

22. The preparation method of yeast glucan according to any one of claims 1-20, wherein, In Step 4, the mass percentage of dry matter in the cell wall emulsion is 10% - 15%.

23. The preparation method of yeast glucan according to claim 21, wherein, In Step 4, the mass percentage of dry matter in the cell wall emulsion is 10% - 15%.

24. The preparation method of yeast glucan according to any one of claims 1-20, wherein, In Step 4, the reaction time is 0.15 - 5 h.

25. The preparation method of yeast glucan according to claim 21, wherein, In Step 4, the reaction time is 0.15 - 5 h.

26. The preparation method of yeast glucan according to claim 22, wherein, In Step 4, the reaction time is 1 - 5 h.

27. The preparation method of yeast glucan according to any one of claims 1-20, wherein, In Step 5, first cool the solution after the reaction in Step 4, then add a third solvent for dilution, and finally add an acid reagent for an extraction reaction.

28. The preparation method of yeast glucan according to claim 21, wherein, In step 5, first cool the solution after the reaction in step 4, then add a third solvent for dilution, and finally add an acid reagent for extraction reaction.

29. The preparation method of yeast glucan according to claim 27, wherein, In step 5, cool the solution after the reaction in step 4 to 50 - 75 °C; and / or, the third solvent is water; and / or, the mass percentage of dry matter in the diluted solution is 5% - 17%; and / or, mix for 0.1 - 5 h after dilution.

30. The preparation method of yeast glucan according to claim 29, wherein, In step 5, cool the solution after the reaction in step 4 to 60 - 75 °C.

31. The preparation method of yeast glucan according to any one of claims 1-20, wherein, In step 5, the acid reagent is selected from one or more of hydrochloric acid, sulfuric acid, and citric acid.

32. The method for preparing yeast glucan according to claim 21, wherein, In step 5, the acid reagent is selected from one or more of hydrochloric acid, sulfuric acid, and citric acid.

33. The preparation method of yeast glucan according to claim 27, wherein, In step 5, the acid reagent is selected from one or more of hydrochloric acid, sulfuric acid, and citric acid.

34. The preparation method of yeast glucan according to claim 29, wherein, In step 5, the acid reagent is selected from one or more of hydrochloric acid, sulfuric acid, and citric acid.

35. The preparation method of yeast glucan according to claim 31, wherein, In step 5, adjust the suspension obtained in step 4 to pH 4 - 6 with an acid reagent; and / or, the extraction temperature is 50 - 100 °C; and / or, the extraction time is 0.5 - 8 h.

36. The preparation method of yeast glucan according to claim 35, wherein, In step 5, the extraction temperature is 70 - 100 °C.

37. The preparation method of yeast glucan according to any one of claims 1-20, wherein, Perform spray drying on the heavy phase obtained in step 6 to obtain a yeast glucan product.

38. The preparation method of yeast glucan according to claim 21, wherein, Perform spray drying on the heavy phase obtained in step 6 to obtain a yeast glucan product.

39. The preparation method of yeast glucan according to claim 27, wherein, Perform spray drying on the heavy phase obtained in step 6 to obtain a yeast glucan product.

40. The preparation method of yeast glucan according to claim 29, wherein Perform spray drying on the heavy phase obtained in step 6 to obtain a yeast glucan product.

41. The preparation method of yeast glucan according to claim 31, wherein, Perform spray drying on the heavy phase obtained in step 6 to obtain a yeast glucan product.

42. The preparation method of yeast glucan according to claim 37, wherein, Spray drying conditions: inlet air temperature is 100 - 180 °C, outlet air temperature is 60 - 90 °C.

43. A yeast glucan, characterized in that, The yeast glucan is prepared by the preparation method of yeast glucan according to any one of claims 1 - 42.

44. The yeast glucan according to claim 43, wherein, The purity of the yeast glucan ≥ 62%.

45. The yeast glucan according to claim 43, wherein, The purity of the yeast glucan is 62% - 91%.

46. The yeast glucan according to claim 43, wherein, The purity of the yeast glucan is 79% - 91%.

Images