Method for purifying alkaloid from oat and application of alkaloid in preparation of anti-allergy soothing composition

Abstract

The invention belongs to the technical field of daily chemicals, and particularly relates to a method for purifying alkaloid from oat and application of the alkaloid to preparation of an anti-allergy soothing composition. The method for purifying alkaloid from oat comprises the following steps: (1) crushing oat to obtain oat powder; (2) mixing oat and water according to a weight ratio of 1: (10-15), putting the mixture into a microwave reactor, and carrying out microwave-assisted extraction to obtain a mixture, (3) carrying out enzymolysis to obtain an enzymatic hydrolysate; (4) adding mixed bacteria into the enzymatic hydrolysate, fermenting, and sterilizing to obtain fermentation liquor; and (5) carrying out centrifugal separation on the fermentation liquor, carrying out subcritical extraction on solids obtained by centrifugal separation, and then recovering the solvent to obtain an extract containing the oat alkaloid. According to the method, the extraction rate of the oat alkaloid is high, and the synergistic effect of the oat alkaloid and the sophora flavescens extract is good.

Description

Technical Field

[0001] The invention belongs to the technical field of daily chemical products, and particularly relates to a method for purifying alkaloids from oats and an application thereof in preparing an anti-allergic and soothing composition. Background Art

[0002] Avena alkaloids are a class of natural compounds found mainly in oats. These compounds belong to the class of polyphenols and have antioxidant, anti-inflammatory and potential cardiovascular protective effects. Due to their significant anti-inflammatory and antioxidant properties, oat alkaloids have shown good effects in anti-allergic and soothing. Due to their excellent anti-allergic and soothing properties, oat alkaloids are widely used in various skin care products, including creams, lotions, facial cleansers, etc., especially products designed for sensitive skin.

[0003] Sophora flavescens, also known as bitter bean root, is a traditional Chinese medicinal material. Its extracts are widely used in skin care products due to its multiple bioactive ingredients, especially in soothing products. Ingredients such as matrine and oxymatrine have significant anti-inflammatory properties, which can inhibit the release of inflammatory response mediators and reduce symptoms such as skin redness, swelling, and itching. In the process of cosmetic research and development, matrine and avenant alkaloids are two components that are often used in synergy. However, during research and development, it was found that the addition of oat alkaloids and sophora flavescens extracts on the market to oat alkaloids at the same time will result in poor storage stability of the product. In the process of extracting oat alkaloids, in addition to the target ingredients, other substances may also be extracted at the same time. These impurities may have adverse reactions with matrine in the sophora flavescens extract, which may affect the storage effect of the final product.

[0004] Therefore, there is an urgent need for a method for purifying alkaloids from oats, so that the extracted oat alkaloids can be safely added to anti-allergic and soothing products with Sophora flavescens extracts and achieve better use effects. Summary of the invention

[0005] The purpose of the present invention is to provide a method for purifying alkaloids from oats and application of the method in preparing an anti-allergic soothing composition.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A method for purifying alkaloids from oats comprises the following steps: (1) Grinding oats to obtain oat powder; (2) mixing oats and water in a weight ratio of 1:(10-15), placing the mixture in a microwave reactor for microwave-assisted extraction, and obtaining a mixture; (3) Add neutral protease to the mixture, and perform enzymolysis at 45°C-48°C for 50-60 minutes; inactivate the enzyme, adjust the pH value to 8-8.5, add alkaline protease, and perform enzymolysis at 45°C-48°C for 30-40 minutes; adjust the pH value to 6.2-6.5, inactivate the enzyme, continue to add fig protease, and perform enzymolysis at 45°C-48°C for 20-30 minutes; inactivate the enzyme to obtain an enzymolysis solution; (4) adding mixed bacteria to the enzymatic hydrolysate for fermentation and sterilization to obtain a fermentation liquid; (5) The fermentation broth is centrifuged, the solid obtained by the centrifugation is subjected to subcritical extraction, and then the solvent is recovered to obtain an extract containing oat alkaloids.

[0007] Furthermore, in the step (3), the amount of the neutral protease is 700-800u / mL of the mixture; the amount of the alkaline protease is 900-1000u / mL of the mixture; and the amount of the ficin is 500-600u / mL of the mixture.

[0008] The present invention can improve the synergistic soothing effect of the oat alkaloid extract and the Sophora flavescens extract by using a specific enzyme to perform gradient fermentation on oats. Analysis shows that the oat alkaloid extract prepared by gradient fermentation has a higher content of oat alkaloids, fewer impurities that have side effects on the Sophora flavescens extract, and is more conducive to the synergistic effect of the two components.

[0009] Furthermore, the mixed bacteria in step (4) include Saccharomyces cerevisiae, Lactobacillus gasseri and Lactobacillus helveticus.

[0010] Furthermore, the amount of the brewer's yeast is 10 8 -10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus gasseri is 10 8 -10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus helveticus is 10 6 -10 7 CFU / mL enzymatic solution.

[0011] The present invention can improve the storage stability of oat alkaloid extract and matrine after mixing by fermenting oats with specific bacteria. Analysis shows that certain metabolites generated during the fermentation process by specific bacteria may form a complex with oat alkaloids and matrine, providing a physical barrier or chemical protection, and at the same time, can decompose the impurities of side effects generated by enzymatic hydrolysis, reducing the impact on matrine.

[0012] Furthermore, the fermentation condition in step (4) is 35-38° C. for 10-14 hours.

[0013] Furthermore, in the step (1), the oats are crushed to a size less than 80 meshes.

[0014] Furthermore, the conditions for microwave-assisted extraction in step (2) are: microwave power 200-250 W, extraction time 1-2 hours.

[0015] Furthermore, the conditions of the subcritical extraction in step (5) are as follows: the extractant is propane, the extraction temperature is 50-70° C., the pressure is 3-4 MPa, the extractant contains an entrainer with a volume fraction of 3-4%, and the entrainer is ethanol.

[0016] The present invention also provides application of the method for purifying alkaloids from oats in preparing an anti-allergic soothing composition.

[0017] The oats used in the present invention are Zhangbei naked oats, Zhangbei County, Zhangjiakou, Hebei. Naked oat varieties include but are not limited to: Zhangbei big oats, Fengning Datan, Huabei No. 2, Baxuan No. 1, Baxuan No. 2, Baxuan No. 3, Baxuan No. 4, Jizhangyou No. 1, Jizhangyou No. 2, Jizhangyou No. 3, Jizhangyou No. 4, Jizhangyou No. 5, Jizhangyou No. 6, Jizhangyou No. 11, Jizhangyou No. 12, Jizhangyou No. 14, Huazao No. 2, Huawan No. 6, Huazhong No. 21, Yuanza No. 1, Yuanza No. 2, Bayou No. 1, Bayou No. 3, Bayou No. 5, Bayou No. 6, Bayou No. 8, Bayou No. 9, Pin No. 2, Huabei No. 1, etc.

[0018] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The oat alkaloids extracted by the present invention are a class of biologically active compounds extracted from oats, and have excellent anti-allergic and soothing effects in skin care products. The oat alkaloids of the present invention can help reduce the skin's sensitive response to external stimuli, and reduce the release of histamine by stabilizing mast cells in the skin, thereby reducing the incidence and severity of allergic reactions. They are particularly effective in relieving skin inflammation, itching and redness. They help repair damaged skin barriers, promote the improvement of the skin's self-repair ability, and make the skin healthier and smoother. Widely used in skin care products for sensitive skin, after-sun repair products, and products for treating mild skin inflammation, oat alkaloids, as a natural and efficient skin care ingredient, are outstanding in providing anti-allergic and soothing effects, and are suitable for maintaining and restoring skin health.

[0019] 2. The present invention can improve the synergistic soothing effect of the oat alkaloid-containing extract and the Sophora flavescens extract by using specific enzymes to perform gradient fermentation on oats.

[0020] 3. The present invention can improve the storage stability of the oat alkaloid extract and matrine after mixing by fermenting oats with specific bacteria. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The raw materials used in the following examples of the present invention are all commercially available products: Candida utilis, strain number: CICC 1769, was purchased from China Industrial Microbiological Culture Collection Center.

[0023] Lactobacillus plantarum, strain number: CICC 24936, was purchased from China Industrial Microbiological Culture Collection Center.

[0024] Bifidobacterium adolescentis, strain number: CICC 6070, was purchased from China Industrial Microbiological Culture Collection Center.

[0025] Saccharomyces cerevisiae, strain number: CICC 1288, was purchased from China Industrial Microbiological Culture Collection Center.

[0026] Lactobacillus gasseri, strain number: SHBCC D25201, was purchased from Shanghai Baozang Microbiology Co., Ltd.

[0027] Lactobacillus helveticus, strain number: CICC 6273, was purchased from China Industrial Microbiological Culture Collection Center.

[0028] Pectinase, enzyme activity 50000u / g. Shanghai Yuanye Biotechnology Co., Ltd.

[0029] Bromelain, enzyme activity 1200u / mg. Shanghai Yuanye Biotechnology Co., Ltd.

[0030] Neutral protease, enzyme activity 100u / mg. Shanghai Yuanye Biotechnology Co., Ltd.

[0031] Papain, enzyme activity 800u / mg. Shanghai Yuanye Biotechnology Co., Ltd.

[0032] Fig enzyme, enzyme activity 100u / mg. Shanghai Yuanye Biotechnology Co., Ltd.

[0033] Alkaline protease, enzyme activity 200u / mg. Shanghai Yuanye Biotechnology Co., Ltd.

[0034] Oats, Zhangbei naked oats, Zhangbei County, Zhangjiakou, Hebei, variety Zhangbei big oats.

[0035] Example 1 This embodiment provides a method for purifying alkaloids from oats, comprising the following steps: (1) Grinding oats to less than 80 mesh to obtain oat powder; (2) mixing oats and water in a weight ratio of 1:12, and placing the mixture in a microwave reactor for microwave-assisted extraction. The conditions for the microwave-assisted extraction are: microwave power of 220 W, extraction time of 1.5 hours, to obtain a mixture; (3) Add neutral protease to the mixture, perform enzymolysis at 46°C for 55 minutes; inactivate the enzyme, adjust the pH value to 8.2, add alkaline protease, perform enzymolysis at 46°C for 35 minutes; adjust the pH value to 6.3, inactivate the enzyme, continue to add fig protease, perform enzymolysis at 46°C for 25 minutes; inactivate the enzyme to obtain enzymolysis solution; the amount of the neutral protease is 750u / mL of the mixture; the amount of the alkaline protease is 950u / mL of the mixture; the amount of the fig protease is 550u / mL of the mixture.

[0036] (4) adding mixed bacteria to the enzymatic hydrolysate for fermentation at 36° C. for 12 hours, sterilizing, and obtaining a fermentation solution; the mixed bacteria include saccharomyces cerevisiae, Lactobacillus gasseri, and Lactobacillus helveticus; the amount of saccharomyces cerevisiae is 10 8 CFU / mL enzymatic solution; the dosage of Lactobacillus gasseri is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus helveticus is 10 7 CFU / mL enzymatic solution.

[0037] (5) The fermentation liquid is centrifuged, and the solid obtained by centrifugation is subjected to subcritical extraction. The conditions of the subcritical extraction are: the extractant is propane, the extraction temperature is 60° C., the pressure is 3.5 MPa, the extractant contains an entrainer with a volume fraction of 3.5%, and the entrainer is ethanol. Then, the solvent is recovered by vacuum rotary evaporation to obtain an extract containing oat alkaloids.

[0038] Example 2 This embodiment provides a method for purifying alkaloids from oats, comprising the following steps: (1) Grinding oats to less than 80 mesh to obtain oat powder; (2) mixing oats and water in a weight ratio of 1:10, and placing the mixture in a microwave reactor for microwave-assisted extraction. The conditions for the microwave-assisted extraction are: microwave power of 200 W, extraction time of 2 hours, to obtain a mixture; (3) Add neutral protease to the mixture, and perform enzymolysis at 45°C for 60 minutes; inactivate the enzyme, adjust the pH value to 8, add alkaline protease, and perform enzymolysis at 48°C for 30 minutes; adjust the pH value to 6.5, inactivate the enzyme, continue to add fig protease, and perform enzymolysis at 45°C for 30 minutes; inactivate the enzyme to obtain enzymolysis solution; the amount of the neutral protease is 800u / mL of the mixture; the amount of the alkaline protease is 900u / mL of the mixture; the amount of the fig protease is 600u / mL of the mixture.

[0039] (4) adding mixed bacteria to the enzymatic hydrolysate for fermentation at 35° C. for 14 hours, sterilizing, and obtaining a fermentation solution; the mixed bacteria include saccharomyces cerevisiae, Lactobacillus gasseri, and Lactobacillus helveticus; the amount of saccharomyces cerevisiae is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus gasseri is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus helveticus is 10 6 CFU / mL enzymatic solution.

[0040] (5) The fermentation liquid is centrifuged, and the solid obtained by centrifugation is subjected to subcritical extraction. The conditions of the subcritical extraction are: the extractant is propane, the extraction temperature is 70° C., the pressure is 3 MPa, the extractant contains an entrainer with a volume fraction of 4%, and the entrainer is ethanol. Then, the solvent is recovered by vacuum rotary evaporation to obtain an extract containing oat alkaloids.

[0041] Comparative Example 1 The difference between this comparative example and Example 1 is: the oat alkaloids prepared in Example 1 in Chinese Patent 201611168303.X.

[0042] Comparative Example 2 The difference between this comparative example and Example 1 is that microwave-assisted extraction is not performed.

[0043] A method for purifying alkaloids from oats comprises the following steps: (1) Grinding oats to less than 80 mesh to obtain oat powder; (2) mixing oats and water in a weight ratio of 1:10 to obtain a mixture; (3) Add neutral protease to the mixture, and perform enzymolysis at 45°C for 60 minutes; inactivate the enzyme, adjust the pH value to 8, add alkaline protease, and perform enzymolysis at 48°C for 30 minutes; adjust the pH value to 6.5, inactivate the enzyme, continue to add fig protease, and perform enzymolysis at 45°C for 30 minutes; inactivate the enzyme to obtain enzymolysis solution; the amount of the neutral protease is 800u / mL of the mixture; the amount of the alkaline protease is 900u / mL of the mixture; the amount of the fig protease is 600u / mL of the mixture.

[0044] (4) adding mixed bacteria to the enzymatic hydrolysate for fermentation at 35° C. for 14 hours, sterilizing, and obtaining a fermentation solution; the mixed bacteria include saccharomyces cerevisiae, Lactobacillus gasseri, and Lactobacillus helveticus; the amount of saccharomyces cerevisiae is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus gasseri is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus helveticus is 10 6 CFU / mL enzymatic solution.

[0045] (5) The fermentation liquid is centrifuged, and the solid obtained by centrifugation is subjected to subcritical extraction. The conditions of the subcritical extraction are: the extractant is propane, the extraction temperature is 70° C., the pressure is 3 MPa, the extractant contains an entrainer with a volume fraction of 4%, and the entrainer is ethanol. Then, the solvent is recovered to obtain an extract containing oat alkaloids.

[0046] Comparative Example 3 The difference between this comparative example and Example 1 is that no enzymatic hydrolysis is performed.

[0047] A method for purifying alkaloids from oats comprises the following steps: (1) Grinding oats to less than 80 mesh to obtain oat powder; (2) mixing oats and water in a weight ratio of 1:12, and placing the mixture in a microwave reactor for microwave-assisted extraction. The conditions for the microwave-assisted extraction are: microwave power of 220 W, extraction time of 1.5 hours, to obtain a mixture; (3) adding mixed bacteria to the mixture for fermentation at 36° C. for 12 hours, sterilizing, and obtaining a fermentation liquid; the mixed bacteria include saccharomyces cerevisiae, Lactobacillus gasseri, and Lactobacillus helveticus; the amount of saccharomyces cerevisiae is 10 8 CFU / mL enzymatic solution; the dosage of Lactobacillus gasseri is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus helveticus is 10 7 CFU / mL enzymatic solution.

[0048] (4) The fermentation liquid is centrifuged and the solid obtained by centrifugation is subjected to subcritical extraction. The subcritical extraction conditions are as follows: the extractant is propane, the extraction temperature is 60° C., the pressure is 3.5 MPa, the extractant contains an entrainer with a volume fraction of 3.5%, and the entrainer is ethanol. The solvent is then recovered to obtain an extract containing oat alkaloids.

[0049] Comparative Example 4 The difference between this comparative example and Example 1 is that the enzymes used in the enzymolysis are different.

[0050] A method for purifying alkaloids from oats comprises the following steps: Specifically, bromelain is added to the mixture, and enzymolysis is performed at 45° C. for 60 minutes; the enzyme is inactivated, papain is added, and enzymolysis is performed at 48° C. for 30 minutes; the pH value is adjusted to 6.5, the enzyme is inactivated, and pectinase is continuously added, and enzymolysis is performed at 45° C. for 30 minutes; the enzyme is inactivated to obtain an enzymolysis solution; the amount of bromelain is 800 u / mL of the mixture; the amount of papain is 900 u / mL of the mixture; and the amount of pectinase is 600 u / mL of the mixture.

[0051] Comparative Example 5 The difference between this comparative example and Example 1 is that no fermentation is performed.

[0052] A method for purifying alkaloids from oats comprises the following steps: (1) Grinding oats to less than 80 mesh to obtain oat powder; (2) mixing oats and water in a weight ratio of 1:10, and placing the mixture in a microwave reactor for microwave-assisted extraction. The conditions for the microwave-assisted extraction are: microwave power of 200 W, extraction time of 2 hours, to obtain a mixture; (3) Add neutral protease to the mixture, and perform enzymolysis at 45°C for 60 minutes; inactivate the enzyme, adjust the pH value to 8, add alkaline protease, and perform enzymolysis at 48°C for 30 minutes; adjust the pH value to 6.5, inactivate the enzyme, continue to add fig protease, and perform enzymolysis at 45°C for 30 minutes; inactivate the enzyme to obtain enzymolysis solution; the amount of the neutral protease is 800u / mL of the mixture; the amount of the alkaline protease is 900u / mL of the mixture; the amount of the fig protease is 600u / mL of the mixture.

[0053] (4) The enzymatic hydrolyzate is centrifuged, and the solid obtained by centrifugation is subjected to subcritical extraction. The conditions of the subcritical extraction are: the extractant is propane, the extraction temperature is 70° C., the pressure is 3 MPa, the extractant contains an entrainer with a volume fraction of 4%, and the entrainer is ethanol. Then, the solvent is recovered to obtain an extract containing oat alkaloids.

[0054] Comparative Example 6 The difference between this comparative example and Example 1 is that the bacteria used for fermentation are different.

[0055] Specifically, the mixed bacteria include Candida utilis, Lactobacillus plantarum and Bifidobacterium adolescentis; the dosage of the Candida utilis is 10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus plantarum is 10 9 CFU / mL enzymatic solution; the dosage of Bifidobacterium adolescentis is 10 6 CFU / mL enzymatic solution.

[0056] Performance Testing 1. Extraction rate of avenant alkaloids: The extraction rate of avenant alkaloids in the avenant alkaloid extracts prepared in test examples 1-2 and comparative examples 1-6 = the weight of avenant alkaloids in the avenant alkaloid-containing extracts / the weight of oats*100%. The results are shown in Table 1.

[0057] Reference for the test method: Ren Yi, Ren Guixing. Study on the extraction and antioxidant activity of oat alkaloids [J]. Transactions of the Chinese Society of Agricultural Engineering, 2008, 24(5): 265-269.

[0058] Table 1 Extraction rate test results test Extraction rate of oat alkaloids% Example 1 5.31 Example 2 5.26 Comparative Example 1 4.63 Comparative Example 2 5.04 Comparative Example 3 4.82 Comparative Example 4 4.96 Comparative Example 5 4.75 Comparative Example 6 4.91 2. An anti-allergic soothing composition was prepared using the oat alkaloid-containing extracts prepared in Examples 1-2 and Comparative Examples 1-6, comprising the following components in percentage by mass: 2% Sophora flavescens extract (98% high-purity matrine, Shaanxi Pinhong Biotechnology Co., Ltd.), 3% oat alkaloid-containing extract, 50% butylene glycol, and the remainder was water.

[0059] (1) Relief test: Hyaluronic acid is widely present in the skin and other tissues. The relationship between hyaluronic acid and skin is very close. Large molecular hyaluronic acid can inhibit inflammatory response, thus alleviating the discomfort caused by skin inflammation. Large molecular hyaluronic acid will be degraded under the action of hyaluronidase, resulting in a decrease in the content of large molecular hyaluronic acid. The decomposition produces the degradation product N-acetylglucosamine. The determination of N-acetylglucosamine in the reaction system can indirectly reflect the activity of hyaluronidase. The anti-allergic activity of the sample was evaluated by the in vitro inhibition of hyaluronidase activity experiment. Inhibiting hyaluronidase activity can reduce the degradation of hyaluronic acid and reduce the sensitivity of the skin.

[0060] Detection method: The anti-allergic soothing composition was mixed with the hyaluronidase solution, the concentration of the composition in the solution was 7w%, and the mixture was shaken and incubated at 37°C for 10 minutes. The hyaluronate solution was added and incubated at 37°C for 45 minutes. The BSA solution was added and incubated for another 10 minutes, the OD600nm value was detected, and the hyaluronidase inhibition rate was calculated. The results are shown in Table 2.

[0061] Table 2 Soothing test results test Inhibition rate Example 1 99.2 Example 2 98.4 Comparative Example 1 85.8 Comparative Example 2 94.0 Comparative Example 3 92.4 Comparative Example 4 93.5 Comparative Example 5 90.6 Comparative Example 6 95.1 (2) The anti-allergic soothing composition was placed in a constant temperature environment of -10°C for 24 hours, then restored to 25°C and placed for 24 hours, and then placed in a constant temperature environment of 50°C for 24 hours. The cycle test was continued for 3 months, and finally the stability was observed. The results are shown in Table 3.

[0062] Table 3 Stability test results test stability Example 1 No abnormality Example 2 No abnormality Comparative Example 1 Turbidity appears Comparative Example 2 No abnormality Comparative Example 3 Turbidity appears Comparative Example 4 Turbidity appears Comparative Example 5 Turbidity appears Comparative Example 6 Turbidity appears From the above performance test results, it can be seen that the method of Example 1-2 has a high extraction rate of oat alkaloids, and at the same time has a good synergistic soothing effect with the Sophora flavescens extract and high storage stability.

[0063] However, the comparative examples were significantly inferior to the examples in the corresponding performance tests because they did not adopt the necessary technical solutions. The soothing effect of the composition obtained after compounding the product prepared in comparative example 1 with the Sophora flavescens extract decreased, and the stability was poor. Comparative example 2 did not perform microwave extraction, and the extraction rate of oat alkaloids decreased. Comparative example 3 did not perform enzymolysis, and the extraction rate decreased. At the same time, the synergistic effect with the Sophora flavescens extract was poor, and the stability was poor. In comparative example 4, different enzymes were used for enzymolysis, and the extraction rate decreased. At the same time, the synergistic effect with the Sophora flavescens extract was poor, and the stability was poor. In comparative example 5, no fermentation was performed, and the extraction rate decreased. At the same time, the synergistic effect with the Sophora flavescens extract was poor, and the stability was poor. In comparative example 6, different bacteria were used for fermentation, and the extraction rate decreased. At the same time, the synergistic effect with the Sophora flavescens extract was poor, and the stability was poor. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0064] The above is 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 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 purifying alkaloids from oats, characterized in that: The following steps are involved: (1) Grinding oats to obtain oat powder; (2) mixing oats and water, and placing the mixture into a microwave reactor for microwave-assisted extraction to obtain a mixture; (3) Add neutral protease to the mixture, and perform enzymolysis at 45°C-48°C for 50-60 minutes; inactivate the enzyme, adjust the pH value to 8-8.5, add alkaline protease, and perform enzymolysis at 45°C-48°C for 30-40 minutes; adjust the pH value to 6.2-6.5, inactivate the enzyme, continue to add fig protease, and perform enzymolysis at 45°C-48°C for 20-30 minutes; inactivate the enzyme to obtain an enzymolysis solution; (4) adding mixed bacteria to the enzymatic hydrolysate for fermentation and sterilization to obtain a fermentation liquid; (5) The fermentation broth is centrifuged, the solid obtained by the centrifugation is subjected to subcritical extraction, and then the solvent is recovered to obtain an extract containing oat alkaloids.

2. The method for purifying alkaloids from oats according to claim 1, characterized in that: In the step (3), the amount of the neutral protease is 700-800u / mL of the mixture; the amount of the alkaline protease is 900-1000u / mL of the mixture; and the amount of the ficin is 500-600u / mL of the mixture.

3. The method for purifying alkaloids from oats according to claim 1, characterized in that: The mixed bacteria in step (4) include Saccharomyces cerevisiae, Lactobacillus gasseri and Lactobacillus helveticus.

4. The method for purifying alkaloids from oats according to claim 3, characterized in that: The amount of brewer's yeast is 10 8 -10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus gasseri is 10 8 -10 9 CFU / mL enzymatic solution; the dosage of Lactobacillus helveticus is 10 6 -10 7 CFU / mL enzymatic solution.

5. The method for purifying alkaloids from oats according to claim 1, characterized in that: The fermentation condition in step (4) is 35-38° C. for 10-14 hours.

6. The method for purifying alkaloids from oats according to claim 1, characterized in that: In the step (2), oats and water are mixed in a weight ratio of 1: (10-15).

7. The method for purifying alkaloids from oats according to claim 1, characterized in that: In the step (1), the oats are crushed to less than 80 meshes.

8. The method for purifying alkaloids from oats according to claim 1, characterized in that: The conditions for microwave-assisted extraction in step (2) are: microwave power 200-250 W, extraction time 1-2 hours.

9. The method for purifying alkaloids from oats according to claim 1, characterized in that: The conditions of the subcritical extraction in step (5) are as follows: the extractant is propane, the extraction temperature is 50-70° C., the pressure is 3-4 MPa, the extractant contains an entrainer with a volume fraction of 3-4%, and the entrainer is ethanol.

10. Use of the method for purifying alkaloids from oats according to any one of claims 1 to 9 in the preparation of an anti-allergic soothing composition.