A method for improving the stability of flavonoids in buckwheat wine

Abstract

This invention discloses a method for improving the stability of flavonoids in buckwheat liquor. First, buckwheat flavonoids are microencapsulated with α-cyclodextrin to form a first physical barrier. Simultaneously, herbal extracts rich in C-glycoside flavonoids (bamboo leaves, bamboo leaves, kudzu root, etc.) are prepared and added to the buckwheat liquor along with the microencapsulated buckwheat flavonoids, controlling the mass ratio of C-glycoside flavonoids to buckwheat flavonoids to be 1:4 to 1:15. After accelerated storage at 50℃ for 90 days, the flavonoid retention rate of the buckwheat liquor reached as high as 92.3%, significantly better than single α-microencapsulation technology (81.4%) and single C-glycoside flavonoid technology (77.5%). Simultaneously, the liquor is clear and transparent, with no sediment formation.

Description

Technical Field

[0001] This invention belongs to the field of liquor brewing technology, specifically relating to a method for improving the stability of flavonoids in buckwheat liquor, and more particularly to a method for significantly improving the stability of flavonoids in buckwheat liquor through the synergistic effect of physical isolation by α-cyclodextrin microcapsules and chemical protection by carbon glycoside flavonoid molecular chaperones. Background Technology

[0002] Buckwheat liquor is a blended liquor made primarily from buckwheat and combined with base spirits. It is highly favored by consumers due to its rich content of flavonoids, such as rutin. Flavonoids possess various health benefits, including antioxidant properties, lowering blood lipids, and improving microcirculation; these are the core active ingredients of buckwheat liquor.

[0003] However, buckwheat liquor generally experiences a decrease in flavonoid content during shelf-life storage. The main reasons are twofold: firstly, the molecular structure of flavonoids in buckwheat (represented by rutin) contains easily hydrolyzed glycosidic bonds, which slowly hydrolyze in the acidic environment of the liquor; secondly, flavonoids are easily oxidized by dissolved oxygen, leading to structural damage. This decrease in flavonoid content directly affects the health benefits and product quality of buckwheat liquor.

[0004] In existing technologies, the following methods are mainly used to solve the problem of flavonoid stability in buckwheat wine: One approach is to add chemical stabilizers, such as disodium EDTA and sodium phytate, which are metal ion chelating agents that block oxidation reactions by chelating metal ions. For example, patent CN121182588A discloses a buckwheat herbal liquor and its preparation method, which uses bamboo leaf extract and phytic acid to construct a dual antioxidant system, and adds citric acid to adjust the pH during the extraction process. While this method has some effect, the application of phytic acid in formulated liquor lacks clear regulatory basis, posing compliance risks. Furthermore, it only focuses on antioxidant protection and fails to address the issue of the physical precipitation of flavonoid molecules.

[0005] Secondly, microencapsulation technology is used to encapsulate buckwheat flavonoids with wall materials such as cyclodextrin, achieving protection through physical isolation. For example, Chinese patent CN111150086B discloses an encapsulation process for wall materials and microencapsulated buckwheat flavonoids, which uses β-cyclodextrin to encapsulate buckwheat flavonoids, improving their stability. However, this method is complex and costly, and the encapsulated flavonoids are slowly released during the shelf life, still facing the risk of oxidation and aggregation, thus failing to achieve continuous protection throughout the entire lifecycle.

[0006] Third, antioxidants such as vitamin C and tea polyphenols can be added. However, vitamin C poses a risk of promoting oxidation at high concentrations, while tea polyphenols may alter the flavor and have limited effect on inhibiting the physical precipitation of flavonoids.

[0007] Therefore, developing a simple, regulatory compliant, and effective method for improving the stability of flavonoids in buckwheat wine has significant industrial value. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for synergistically improving the stability of flavonoids in buckwheat wine. By leveraging the synergistic effect of physical isolation by α-cyclodextrin microcapsules and chemical protection by carbon glycoside flavonoid molecular chaperones, the problem of the decrease in flavonoid content during shelf-life storage of buckwheat wine can be solved.

[0009] The technical solution adopted by this invention to solve its technical problem is: A method for improving the stability of flavonoids in buckwheat wine includes the following steps: S1. Preparation of α-cyclodextrin microencapsulated tartary buckwheat flavonoids: Using α-cyclodextrin as the wall material, tartary buckwheat flavonoid extract was spray-dried and microencapsulated to obtain microencapsulated tartary buckwheat flavonoid powder; the tartary buckwheat flavonoid content in the microencapsulated tartary buckwheat flavonoids was 10-30%, and the encapsulation rate was 85-95%; S2. Preparation of carbon glycoside flavonoid extract: Herbs rich in carbon glycoside flavonoids are extracted with alcohol. The extract is then coarsely filtered and concentrated for later use. S3. Blending of liquor: Add the α-cyclodextrin microencapsulated buckwheat flavonoids obtained in step S1 and the carbon glycoside flavonoid extract obtained in step S2 to the buckwheat liquor at the same time. Control the amount of microencapsulated buckwheat flavonoids added so that the total flavonoid content in the buckwheat liquor reaches the target value, and control the mass ratio of carbon glycoside flavonoids in the carbon glycoside flavonoid extract to flavonoids in the buckwheat liquor to be 1:4 to 1:15. S4. Fine filtration of the liquor: The buckwheat liquor containing microencapsulated tartary buckwheat flavonoids and carbon glycoside flavonoid extracts is filtered. The filtered liquor should be free of impurities and suspended matter, and be clear and transparent.

[0010] Preferably, the preparation method of α-cyclodextrin microencapsulated buckwheat flavonoids in step S1 includes mixing buckwheat flavonoid extract with α-cyclodextrin at a mass ratio of 1:3-1:6, adding water and stirring evenly, spray drying, with an inlet air temperature of 160-180℃ and an outlet air temperature of 80-90℃.

[0011] Preferably, the herbaceous plants rich in carbon glycoside flavonoids in step S2 include one or more of bamboo leaves, bamboo leaves, and kudzu root; the carbon glycoside flavonoids include one or more of purslane, isopurslane, vitexin, isovitexin, and puerarin.

[0012] Preferably, in step S2, the alcohol concentration is 50-70% vol, the mass ratio of herb to alcohol is 1:10-20, the extraction method is maceration extraction, maceration at room temperature for 10-15 days, filtration, and concentration of the filtrate under reduced pressure to a crude drug concentration of 5-10 g / mL.

[0013] Preferably, the extraction method in step S2 is reflux extraction, with an extraction heating temperature of 75±3℃, each extraction lasting 1-2 hours, and the extraction is repeated 2-3 times. After filtration, the filtrate is concentrated under reduced pressure to a crude drug concentration of 5-10 g / mL.

[0014] Preferably, the mass ratio of the carbon glycoside flavonoids in step S3 to the flavonoids in the buckwheat wine is 1:6 to 1:10.

[0015] Preferably, in the wine filtration step described in step S4, a filter element with a pore size of 0.45 μm or less is used for filtration.

[0016] The beneficial effects of this invention are: (1) A dual-barrier synergistic stabilization system of "α-cyclodextrin microcapsules + carbon glycoside flavonoid molecular chaperone" was constructed for the first time. This invention combines α-cyclodextrin microencapsulation technology with the molecular chaperone effect of carbon glycoside flavonoids for the first time to construct a dual-barrier synergistic stabilization system of "physical isolation + chemical protection". By microencapsulating tartary buckwheat flavonoids with α-cyclodextrin, the first physical isolation barrier is formed inside the wall material, which delays the direct contact between flavonoids and the wine environment; at the same time, the added carbon glycoside flavonoids (such as rutin in bamboo leaves and puerarin in kudzu root) form intermolecular hydrogen bonds and π-π stacking interactions with the tartary buckwheat flavonoids (rutin) slowly released from the microcapsules, forming a non-covalent complex, which plays the role of an antioxidant sacrificial agent and a molecular chaperone that inhibits physical precipitation, thus constituting the second chemical protection barrier.

[0017] (2) Experiments of this invention show (see Table 1) that after 90 days of accelerated storage at 50℃, the flavonoid retention rate of buckwheat wine using microencapsulation technology alone (Comparative Example 2) was 81.4%, and the retention rate of added C-glycoside flavonoid extract alone (Comparative Example 3) was 77.5%. However, the flavonoid retention rate of buckwheat wine using the synergistic method of this invention (Example 1) was as high as 92.3%, significantly higher than the expected effect of the sum of the two (81.4% + 77.5% - 100% = 58.9%, the actual synergistic effect far exceeds the simple superposition of single technologies). At the same time, the wine treated by the synergistic method was clear and transparent, with no sedimentation, and had excellent sensory quality.

[0018] (3) The α-cyclodextrin used in this invention is a food additive that is permitted to be used in various foods in appropriate amounts as needed in production, as specified in GB 2760. It can be used directly in the preparation of wine without any limit on the amount added, and the regulatory pathway is clear. The bamboo leaves and kudzu root from which the carbon glycoside flavonoids are derived are both medicinal and edible substances, and the bamboo leaves are a traditional food raw material, all of which have good compliance.

[0019] (4) The method of the present invention does not require complex extraction equipment and processes. It only requires adding the microencapsulated buckwheat flavonoid and carbon glycoside flavonoid extract directly to buckwheat wine, stirring evenly and then filtering. The operation is simple and suitable for large-scale industrial production. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementation schemes and not for limiting the scope of protection of this invention.

[0021] When a range of values ​​is given, it should be understood that, unless otherwise stated in this invention, the two endpoints of each range and any value between the two endpoints may be selected.

[0022] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly used in the field to which this invention pertains. The terminology used to describe this invention is intended only to describe a particular implementation and is not intended to limit the scope of the teachings. This invention can be implemented using any prior art methods, apparatus, and materials similar to or equivalent to those described, used, or made in the embodiments of this invention.

[0023] Unless otherwise specified, "%" and "parts" as used in this document refer to "mass %" and "mass parts," respectively.

[0024] The term “and / or” as used herein should be understood to mean any one of the options or any combination of two or more of the options.

[0025] As used herein, the term "about" indicates a range of ±20% of the following value. In some embodiments, the term "about" indicates a range of ±10% of the following value. In some embodiments, the term "about" indicates a range of ±5% of the following value.

[0026] The following embodiments are provided to aid in understanding the present invention. However, it should be understood that these embodiments are for illustrative purposes only and do not constitute any limitation. The actual scope of protection of the present invention is set forth in the claims. It should be understood that any modifications and changes can be made without departing from the spirit of the present invention. Unless otherwise specified, the raw materials used in the embodiments are all commercially available products in the art, their specifications are conventional specifications in the art, and the methods used are conventional methods in the art. The instruments and equipment used in the embodiments are conventional instruments and equipment in the art.

[0027] Through extensive research, the inventors discovered that combining α-cyclodextrin microencapsulation technology with the "molecular chaperone" effect of C-glycoside flavonoids to construct a dual-barrier system of physical isolation and chemical protection can produce unexpected synergistic effects, significantly superior to the simple superposition of single technical routes. Specifically, microencapsulated buckwheat flavonoids are slowly released during the shelf life. The released rutin forms an intermolecular complex with the C-glycoside flavonoids, which act as an antioxidant sacrificial agent and a molecular chaperone that inhibits physical precipitation, forming a second layer of chemical protection. Experiments show that after accelerated storage at 50°C for 90 days, the flavonoid retention rate of buckwheat liquor is as high as 92.3%, significantly better than single α-microencapsulation technology (81.4%) and single C-glycoside flavonoid technology (77.5%), producing a synergistic effect of 1+1>2. At the same time, the liquor is clear and transparent, with no sediment formation. The α-cyclodextrin used in the method of this invention is a food additive that is permitted to be used in various foods in appropriate amounts as needed according to GB 2760. It has high regulatory compliance and significant industrial application value.

[0028] This specific embodiment provides a method for synergistically improving the stability of flavonoids in buckwheat wine, including the following steps: S1. Preparation of α-Cyclodextrin-encapsulated tartary buckwheat flavonoids: Using α-cyclodextrin as the wall material, tartary buckwheat flavonoid extract was spray-dried and microencapsulated. The tartary buckwheat flavonoid extract and α-cyclodextrin were mixed at a mass ratio of 1:3-1:6, water was added and stirred evenly, and the mixture was spray-dried at an inlet air temperature of 160-180℃ and an outlet air temperature of 80-90℃ to obtain microencapsulated tartary buckwheat flavonoid powder. The tartary buckwheat flavonoid content in the microencapsulated tartary buckwheat flavonoids was 10-30%, and the encapsulation rate was 85-95%. S2. Preparation of carbon glycoside flavonoid extract: Use 50-70% alcohol to extract herbaceous plants rich in carbon glycoside flavonoids, such as bamboo leaves, bamboo leaves, and kudzu root, or one or more of these herbs. The carbon glycoside flavonoids include one or more of the following: styracin, isostyracin, vitexin, isovitexin, and puerarin. The mass ratio of herbaceous plants to alcohol is 1:10-20. The extraction method is maceration extraction or reflux extraction. The extract is filtered, and the filtrate is concentrated under reduced pressure to a crude drug concentration of 5-10 g / mL for later use. S3. Blending of liquor: Add the α-cyclodextrin microencapsulated buckwheat flavonoids obtained in step S1 and the carbon glycoside flavonoid extract obtained in step S2 to the buckwheat liquor at the same time. Control the amount of microencapsulated buckwheat flavonoids added so that the total flavonoid content in the buckwheat liquor reaches the target value. Control the mass ratio of carbon glycoside flavonoids in the carbon glycoside flavonoid extract to flavonoids in the buckwheat liquor to be 1:4 to 1:15, preferably 1:6 to 1:10. S4. Fine filtration of the liquor: The buckwheat liquor containing microencapsulated tartary buckwheat flavonoids and carbon glycoside flavonoid extracts is filtered using a filter cartridge with a pore size of 0.45μm or smaller. The filtered liquor should be free of impurities and suspended matter, and be clear and transparent.

[0029] The present invention will be further described below with reference to specific embodiments and comparative examples, but the scope of protection of the present invention is not limited thereto. All embodiments and comparative examples used the same batch of raw materials and were carried out under the same environmental conditions.

[0030] All the buckwheat liquors used in the following examples were prepared from the same batch. The base liquor was a blend of light, strong, soy sauce, and three-fragrance baijiu with an alcohol content of 45% vol. The amount of buckwheat extract added was the same, and the initial total flavonoid content was determined to be 0.2 g / L. The total flavonoid content was determined by ultraviolet spectrophotometry, using rutin as a standard, and the absorbance was measured at a wavelength of 510 nm.

[0031] Example 1 This embodiment provides a method for improving the stability of flavonoids in buckwheat wine, including the following steps: S1. Preparation of α-Cyclodextrin microencapsulated tartary buckwheat flavonoids: 1.0 kg of tartary buckwheat flavonoid extract (total flavonoids ≥ 50%) was mixed with 5.0 kg of α-cyclodextrin, 10 L of water was added and stirred evenly, and spray-dried (inlet air temperature 170℃, outlet air temperature 85℃) to obtain α-cyclodextrin microencapsulated tartary buckwheat flavonoid powder. The total flavonoid content in the microencapsulated tartary buckwheat flavonoids was determined to be 8.5%, and the encapsulation rate was 92%.

[0032] S2. Preparation of Bamboo Leaf Carbon Glycoside Flavonoid Extract: 50 kg of bamboo leaves (light bamboo leaves) were added to 1000 L of 60% vol edible alcohol and extracted at room temperature for 12 days. The extract was filtered, and the filtrate was concentrated under reduced pressure to a crude drug concentration of 8 g / mL to obtain the bamboo leaf extract. HPLC analysis showed that the total flavonoid content in the bamboo leaf extract was 15.2 g / L, of which the carbon glycoside flavonoid content (calculated as arbutin and isoarbutin) was 9.8 g / L.

[0033] S3. Blending the liquor: Take 1000L of buckwheat liquor base, first add 2.4kg of the α-cyclodextrin microencapsulated buckwheat flavonoid powder prepared in step S1 (providing approximately 200g of buckwheat flavonoids, bringing the total buckwheat flavonoid content in the liquor to 0.2g / L), and stir well. Then, based on the mass ratio of C-glycoside flavonoids to buckwheat flavonoids = 1:8, the required amount of C-glycoside flavonoids = 200g ÷ 8 = 25g, and the required volume of bamboo leaf extract = 25g ÷ 9.8g / L ≈ 2.55L. Add 2.55L of bamboo leaf extract to the buckwheat liquor and stir well again.

[0034] S4. Fine filtration of the wine: The blended wine is filtered through a 0.45μm filter before bottling.

[0035] Example 2 This embodiment provides a method for improving the stability of flavonoids in buckwheat wine, including the following steps: S1. Preparation of α-cyclodextrin microencapsulated buckwheat flavonoids: Same as in Example 1.

[0036] S2. Preparation of the extract of carbon-glycoside flavonoids from bamboo leaves: 50 kg of bamboo leaves were extracted by reflux under condensation at 75℃ for 2 hours each time, for a total of 3 extractions. The extract was then filtered, and the filtrate was concentrated under reduced pressure to obtain the bamboo leaf extract. HPLC analysis showed that the total flavonoid content in the bamboo leaf extract was 13.5 g / L, of which the carbon-glycoside flavonoid content was 8.6 g / L.

[0037] S3. Blending the liquor: Take 1000L of buckwheat liquor base and add 2.4kg of α-cyclodextrin microencapsulated buckwheat flavonoid powder from step S1. Based on a C-glycoside flavonoid: buckwheat flavonoid mass ratio of 1:8, the required amount of C-glycoside flavonoid is 25g, and the required volume of bamboo leaf extract is approximately 25g ÷ 8.6g / L ≈ 2.91L. Add 2.91L of bamboo leaf extract to the buckwheat liquor and stir well.

[0038] S4. Fine filtration of the wine: Same as in Example 1.

[0039] Example 3 This embodiment provides a method for improving the stability of flavonoids in buckwheat wine, including the following steps: S1. Preparation of α-cyclodextrin microencapsulated buckwheat flavonoids: Same as in Example 1.

[0040] S2. Preparation of Pueraria lobata C-glycoside flavonoid extract: 50 kg of Pueraria lobata was extracted using the same method as in Example 1 to obtain Pueraria lobata extract. HPLC analysis showed that the total flavonoid content in the Pueraria lobata extract was 12.8 g / L, of which the C-glycoside flavonoid content (calculated as puerarin) was 7.2 g / L.

[0041] S3. Blending the liquor: Take 1000L of buckwheat liquor base and add 2.4kg of α-cyclodextrin microencapsulated buckwheat flavonoid powder from step S1. Based on a C-glycoside flavonoid: buckwheat flavonoid mass ratio of 1:8, the required amount of C-glycoside flavonoid is 25g, and the required volume of kudzu root extract is approximately 25g ÷ 7.2g / L ≈ 3.47L. Add 3.47L of kudzu root extract to the buckwheat liquor and stir well.

[0042] S4. Fine filtration of the wine: Same as in Example 1.

[0043] Example 4 This embodiment follows the method of Example 1, except that the mass ratio of carbon glycoside flavonoids to buckwheat flavonoids in step S3 is changed to 1:4, 1:6, 1:10, 1:15, and 1:20, respectively. The required volume of bamboo leaf extract is calculated and added to buckwheat wine. The remaining steps are the same.

[0044] Comparative Example 1 Take 1000L of the same batch of buckwheat liquor, without adding any microencapsulated buckwheat flavonoids and carbon glycoside flavonoid extracts, filter directly through a 0.45μm filter cartridge and then bottle it.

[0045] Comparative Example 2 The base liquor was brewed using the same process as Comparative Example 1. The base liquor was then mixed with the same amount (equivalent to 0.5% of dry buckwheat matter) of the same batch of buckwheat extract as in Example 1, and the mixture was fully dissolved. After the base liquor was stored for 12 months, the EC content was tested.

[0046] Comparative Example 3 Take 1000L of the same batch of buckwheat liquor, add 2.4kg of α-cyclodextrin microencapsulated buckwheat flavonoid powder prepared in Example 1 (same as Example 1), without adding any carbon glycoside flavonoid extract, stir evenly, filter through a 0.45μm filter element and then fill.

[0047] Comparative Example 4 Take 1000L of the same batch of buckwheat liquor, add 2.55L of 60%vol edible alcohol (the same volume as in Example 1), stir well, filter through a 0.45μm filter, and then bottle.

[0048] Comparative Example 5 Take 1000L of the same batch of buckwheat liquor, add 0.5g / L of tea polyphenol extract (total polyphenols ≥98%) (according to the maximum allowable amount in GB 2760), stir well, filter through a 0.45μm filter cartridge and then bottle.

[0049] Comparative Example 6 A sample of buckwheat herbal liquor was prepared according to the method of Example 10 disclosed in prior art CN121182588A. The specific steps are as follows: Roast buckwheat rice at 160℃ for 15 minutes, add kudzu root slices and polygonatum cubes, and ultrafine grind them. Mix 10% buckwheat ultrafine powder, 5% kudzu root ultrafine powder, 4% polygonatum ultrafine powder and 90% soy sauce base liquor, and extract under pressure at 25℃ for 8 days in a closed circulation. 24 hours after the start of extraction, add 0.05% of 6% citric acid solution to lower the pH of the system to 4.5 to obtain primary extracted buckwheat liquor. After low-temperature active extraction at 45℃ for 7 days, press, separate solid and liquid, collect the liquid and filter to obtain buckwheat herbal extract base liquor. Add 0.04% bamboo leaf extract and 0.01% phytic acid to the buckwheat herbal extract base liquor, stir and mix well, and seal and age for 2 weeks. Blend the aged buckwheat herbal liquor with 10% soy sauce base liquor to adjust the final alcohol content to 45% vol, then add 0.05% of 6% citric acid solution and stir well to obtain buckwheat herbal liquor.

[0050] Experimental detection methods and results The above-described examples and comparative samples were placed in a constant temperature chamber at 50±1℃ for accelerated storage experiments, and samples were taken and tested at 0 days, 30 days, 60 days, and 90 days. Each sample was tested in triplicate, and the average value of the results was taken.

[0051] detection indicators 1. Total flavonoid content: The absorbance was measured at a wavelength of 510 nm using ultraviolet spectrophotometry with rutin as a standard, and the total flavonoid content and retention rate were calculated.

[0052] 2. Sensory stability: Observe the color and clarity of the wine, and record whether any sediment has formed.

[0053] The experimental results are shown in Table 1.

[0054] Table 1. Total flavonoid retention rate and sensory characteristics of different samples

[0055] Results Analysis 1. Significant synergistic effect: In Example 1 (bamboo leaf + α-microcapsule), the flavonoid retention rate after 90 days was as high as 92.3%, while that of Comparative Example 2 (α-microcapsule only) was 81.4%, and that of Comparative Example 3 (bamboo leaf extract only) was 77.5%. The retention rates of the two alone were 81.4% and 77.5%, respectively, and the expected value of their simple superposition was far lower than 92.3%, proving that the synergistic method of the present invention produced a synergistic effect of 1+1>2.

[0056] 2. Significant advantages compared to existing technologies: Comparative Example 6 (CN121182588A method) showed a flavonoid retention rate of 77.8% after 90 days, with trace amounts of precipitation. In contrast, Example 1 of this invention achieved a retention rate 14.5 percentage points higher, and the wine was clear and transparent without any precipitation. More importantly, the method of this invention does not use phytic acid at all, resulting in higher regulatory compliance.

[0057] 3. Optimal ratio range: Example 4 shows that the best effect (retention rate >90%) is achieved when the mass ratio of carbon glycoside flavonoids to buckwheat flavonoids is in the range of 1:6-1:10. The effect decreases when the ratio exceeds 1:15 (the retention rate is 84.1% and there is slight loss of luster at 1:20), indicating that there is an optimal ratio range.

[0058] 4. Excellent sensory stability: The wine treated by the synergistic method of this invention remained clear and transparent after 90 days of accelerated storage, without any sedimentation, while the comparative group all showed varying degrees of sedimentation or color darkening.

[0059] 5. Effects of different sources of C-glycoside flavonoids: Examples 1-3 show that C-glycoside flavonoids from bamboo leaves, bamboo leaves, and kudzu root can all effectively improve stability, with bamboo leaves and bamboo leaves showing the best effect, followed by kudzu root, indicating that the method of the present invention has good universality.

[0060] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A method for improving the stability of flavonoids in buckwheat wine, characterized in that, Includes the following steps: S1. Preparation of α-cyclodextrin microencapsulated tartary buckwheat flavonoids: Using α-cyclodextrin as the wall material, tartary buckwheat flavonoid extract was spray-dried and microencapsulated to obtain microencapsulated tartary buckwheat flavonoid powder; the tartary buckwheat flavonoid content in the microencapsulated tartary buckwheat flavonoids was 10-30%, and the encapsulation rate was 85-95%; S2. Preparation of carbon glycoside flavonoid extract: Herbs rich in carbon glycoside flavonoids are extracted with alcohol. The extract is then coarsely filtered and concentrated for later use. S3. Blending of liquor: Add the α-cyclodextrin microencapsulated buckwheat flavonoids obtained in step S1 and the carbon glycoside flavonoid extract obtained in step S2 to the buckwheat liquor at the same time. Control the amount of microencapsulated buckwheat flavonoids added so that the total flavonoid content in the buckwheat liquor reaches the target value, and control the mass ratio of carbon glycoside flavonoids in the carbon glycoside flavonoid extract to flavonoids in the buckwheat liquor to be 1:4 to 1:

15. S4. Fine filtration of the liquor: The buckwheat liquor containing microencapsulated tartary buckwheat flavonoids and carbon glycoside flavonoid extracts is filtered. The filtered liquor should be free of impurities and suspended matter, and be clear and transparent.

2. The method according to claim 1, characterized in that, The preparation method of α-cyclodextrin microencapsulated buckwheat flavonoids in step S1 includes mixing buckwheat flavonoid extract with α-cyclodextrin at a mass ratio of 1:3-1:6, adding water and stirring evenly, spray drying, with an inlet air temperature of 160-180℃ and an outlet air temperature of 80-90℃.

3. The method according to claim 1, characterized in that, The herbaceous plants rich in carbon glycoside flavonoids in step S2 include one or more of bamboo leaves, bamboo leaves, and kudzu root; the carbon glycoside flavonoids include one or more of purslane, isopurslane, vitexin, isovitexin, and puerarin.

4. The method according to claim 1, characterized in that, In step S2, the alcohol concentration is 50-70% vol, the mass ratio of herb to alcohol is 1:10-20, the extraction method is maceration extraction, maceration at room temperature for 10-15 days, filtration, and concentration of filtrate under reduced pressure to a crude drug concentration of 5-10 g / mL.

5. The method according to claim 1, characterized in that, The extraction method in step S2 is reflux extraction with a heating temperature of 75±3℃. Each extraction lasts for 1-2 hours, and the extraction is repeated 2-3 times. The filtrate is then filtered and concentrated under reduced pressure to a crude drug concentration of 5-10 g / mL.

6. The method according to claim 1, characterized in that, The mass ratio of the carbon glycoside flavonoids in step S3 to the flavonoids in the buckwheat wine is 1:6 to 1:

10.

7. The method according to claim 1, characterized in that, In the wine filtration step described in step S4, a filter element with a pore size of 0.45μm or smaller is used for filtration.

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