A method and kit for visualizing and rapidly identifying the age of tartary buckwheat wine based on a double-channel color development reaction

Abstract

This invention discloses a rapid visual identification method and kit for the vintage of buckwheat liquor based on a dual-channel colorimetric reaction. Addressing the issue of counterfeit vintage in buckwheat liquor, it sets up two independent detection channels: the first channel uses a solid-phase extraction column with a mixture of polyamide and uncapped C18 filler or uncapped C18 filler to remove flavonoid interference, controlling the sample flow rate through the column at 0.8~1.2 mL / min, and uses a p-toluenesulfonic acid-p-dimethylaminobenzaldehyde solid colorimetric strip to detect the aging year of the base liquor for 2~5 minutes; the second channel uses ferric chloride-potassium ferricyanide colorimetric paper to detect the aging time based on the negative correlation between reducing substances and bottle storage time. The dual-dimensional results comprehensively determine the authenticity of the vintage label. This invention is safe to operate, provides intuitive results, and offers strong anti-counterfeiting features with dual verification, making it suitable for various scenarios such as consumer self-inspection, liquor company quality control, and market supervision.

Description

Technical Field

[0001] This invention relates to the field of rapid detection technology for baijiu (Chinese liquor), and in particular to a rapid visual identification method and kit for buckwheat liquor based on dual-channel colorimetric reaction. Background Technology

[0002] Herbal baijiu products, exemplified by Maopu Buckwheat Liquor, are brewed using a pure grain solid-state process, incorporating active ingredients from buckwheat, kudzu root, and other herbs. They possess unique flavor characteristics and health benefits, leading to continuously increasing market recognition and consumption. Vintage is a key determinant of the core quality and commercial value of buckwheat liquor. Its vintage information comprises two independent core dimensions: first, the aging years of the base liquor in ceramic jars, directly determining the body's richness and flavor complexity; and second, the bottling and aging time of the finished liquor, directly affecting its stability and taste harmony. Together, these two dimensions constitute a complete quality vintage system for buckwheat liquor. As the market for vintage liquor continues to heat up, counterfeit practices such as falsely labeling base liquor vintages, using inferior ingredients, repackaging old liquor in new bottles, and altering bottling and production dates are becoming increasingly prominent, seriously damaging consumers' legitimate rights and disrupting the healthy development order of the baijiu industry.

[0003] Currently, the techniques for identifying the vintage of baijiu (Chinese liquor) are mainly divided into four categories, and all of these techniques have a core flaw that makes them difficult to adapt to the testing scenarios of buckwheat liquor:

[0004] One method is large-scale precision instrument detection, represented by technologies such as gas chromatography-mass spectrometry and gas chromatography-olfactometry. Although the detection accuracy is high, the equipment is expensive, the operation process is complex, and the detection cycle is long. It requires professional personnel to complete the test in a laboratory environment, which cannot achieve rapid on-site detection and makes it difficult to popularize it in consumer and grassroots regulatory scenarios. The second method is sensory evaluation, which relies on the professional experience and sensory sensitivity of wine tasters. It has the drawbacks of strong subjectivity, inconsistent evaluation standards, and difficulty in quantifying results. It cannot resonate effectively with ordinary consumers and lacks market universality. The third method is the single-index detection method, which only tests the single dimension of the base wine's vintage. This method is not only easily counterfeited by adding external characteristic markers, but it also cannot identify hidden counterfeiting behaviors such as putting new wine in old bottles or altering the bottling date. Therefore, its anti-counterfeiting capabilities have a fundamental flaw. Fourthly, colorimetric detection methods based on colorimetric reactions, while possessing the potential for rapid and visual detection, lack effective solutions to address the inherent background color interference caused by the high content of flavonoids in buckwheat liquor. This can easily lead to distorted colorimetric results and inaccurate vintage determination. Furthermore, traditional colorimetric systems often employ highly corrosive and volatile hazardous reagents such as concentrated sulfuric acid. Existing Ehrlich reaction-related technologies in the food and liquor testing fields all use concentrated sulfuric acid as an acidic catalyst, posing serious safety risks and making it impossible to conduct on-site demonstrations for consumers in public settings, thus severely limiting their application scenarios.

[0005] In summary, there is currently no solution in the industry that can simultaneously achieve dual-dimensional anti-counterfeiting verification, specifically address the interference of flavonoid matrix in buckwheat wine, be safe and non-toxic to operate, provide intuitive and visual results, and be suitable for rapid on-site testing. This technological gap urgently needs to be filled. Summary of the Invention

[0006] In view of this, the present invention proposes a rapid identification method and kit for the age of buckwheat liquor based on dual-channel colorimetric reaction. It aims to address the core defects of existing buckwheat liquor age detection technologies, such as the inability to eliminate matrix interference, weak anti-counterfeiting capabilities, poor operational safety, and inability to be applied on-site. The invention achieves dual-dimensional cross-verification, safe visualization, and rapid on-site identification of buckwheat liquor age that can be operated by non-professionals.

[0007] The technical solution of this invention is implemented as follows: This invention provides a rapid visual identification method for the vintage of buckwheat liquor based on a dual-channel colorimetric reaction, comprising the following steps: S1 Base Wine Aging Age Detection: Take the buckwheat wine sample to be tested and pass it through a micro solid-phase extraction column filled with a mixture of polyamide and uncapped C18 packing material or uncapped C18 packing material to remove flavonoid interference substances. The buckwheat wine sample to be tested is passed through the micro solid-phase extraction column at a flow rate of 0.8~1.2mL / min, and the flavonoid removal solution is collected. Add a solid colorimetric tablet containing p-toluenesulfonic acid and p-dimethylaminobenzaldehyde to the flavonoid removal solution to carry out a colorimetric reaction. The reaction time is 2~5 minutes. The color of the solution after the reaction is compared with the pre-prepared base wine age-color scale color chart to determine the base wine aging age or age range of the sample to be tested. S2 Finished Wine Bottle Storage Time Test: Take another sample of buckwheat wine to be tested. No pretreatment is required. The color reaction is carried out directly using the ferric chloride-potassium ferricyanide color development system. The reaction time is 20-60 seconds. Utilizing the negative correlation between color depth and bottle storage time, the color development result after the reaction is compared with the pre-made bottle storage time-color scale comparison card to determine the bottle storage time or time range of the sample to be tested. S3 Dual Verification Comprehensive Judgment: The aging year of the base wine obtained in step S1 and the bottling time obtained in step S2 are compared with the labeling information of the buckwheat wine product to be tested, and the authenticity of the product's year label is comprehensively judged.

[0008] The relevant terms are defined as follows: The aging markers specifically refer to furfural and long-chain fatty acid ethyl esters, which are characteristic substances generated during the aging of buckwheat base liquor in ceramic jars. The term "basic agreement" specifically refers to a deviation between the test result and the product label value / production date calculated value being ≤1 year. "Significantly lower than" specifically refers to a test result that is ≥2 years lower than the product's labeled value; The colorimetric system specifically refers to colorimetric test paper prepared by impregnating it with a colorimetric reagent and then drying it. In some embodiments, the packing material of the micro solid-phase extraction column is a mixture of polyamide and uncapped C18 filler, with a mass ratio of 1:0.5~2 and a total packing amount of 0.2~1.0g. The amide bonds in the polyamide molecules can form specific hydrogen bonds with the phenolic hydroxyl groups of flavonoids in buckwheat liquor for adsorption, accurately targeting flavonoid interference substances. The free silanol groups on the surface of the uncapped C18 filler can assist in the adsorption of residual flavonoids through polar interactions. At the same time, it has no retention effect on weakly polar aldehydes and non-polar long-chain fatty acid esters aging markers generated during the aging process of the base liquor in ceramic jars. The combination of the two can efficiently remove background color interference while retaining the target analytes to the greatest extent, fundamentally solving the industry pain point of colorimetric detection of flavonoid background color interference in buckwheat liquor. The above ratio and packing amount range can take into account both flavonoid adsorption capacity and column processing efficiency, adapting to the needs of rapid on-site operation.

[0009] Before use, the micro solid phase extraction column needs to be activated and equilibrated. Specifically, it is activated by passing anhydrous ethanol through the column at a flow rate of 1 mL / min, with the activation volume being twice the volume of the column packing. Then, it is equilibrated by passing purified water through the column at the same flow rate, with the equilibration volume being twice the volume of the column packing. After activation and equilibration, the sample is loaded immediately to ensure that the packing forms a stable adsorption environment and achieves selective adsorption of flavonoids.

[0010] In some embodiments, after treatment with a micro solid-phase extraction column, the recovery rate of aging markers in the liquor is ≥80%. These aging markers specifically refer to furfural and long-chain fatty acid ethyl esters, characteristic substances generated during the aging process of buckwheat-based liquor in ceramic jars. A flow rate range of 0.8~1.2 mL / min ensures sufficient hydrogen bonding time between flavonoids and the solid-phase extraction packing material, achieving efficient adsorption and removal of flavonoids. This avoids the problems of reduced detection efficiency due to excessively slow flow rates and insufficient adsorption due to excessively fast flow rates, ensuring a high recovery rate of aging markers and providing a core guarantee for the accuracy of subsequent colorimetric reactions.

[0011] In some embodiments, the mass ratio of p-toluenesulfonic acid to p-dimethylaminobenzaldehyde in the solid chromogenic tablet is 2:1 to 10:1. The solid chromogenic tablet is formed by compression molding with pharmaceutical filler, which accounts for 80% to 90% of the total mass of the tablet. p-Toluenesulfonic acid is a solid organic strong acid with an acidity close to that of sulfuric acid. It is non-oxidizing, non-volatile, non-toxic, and non-flammable, and can provide the strong acidic catalytic environment required for the Ehrlich reaction, completely replacing concentrated sulfuric acid in the traditional system. This overcomes the long-standing technical prejudice in the field that "only concentrated sulfuric acid can efficiently catalyze the Ehrlich chromogenic reaction." p-Dimethylaminobenzaldehyde can undergo a condensation reaction with the aldehyde group in the aging marker under acidic conditions to generate a red to purplish-red condensate with a large π-conjugated system. The color depth is positively correlated with the content of the aging marker, thus forming a precise correspondence with the aging year of the base wine. The above-mentioned mass ratio range can ensure a balance between catalytic efficiency and colorimetric sensitivity. The solid compressed tablet form can achieve stable storage at room temperature, eliminating the safety risks of liquid reagents and meeting the needs of on-site public demonstrations.

[0012] In some embodiments, the ferric chloride-potassium ferricyanide colorimetric system is a colorimetric test paper prepared by impregnating the test paper with a colorimetric reagent and then drying it. The mass concentrations of ferric chloride and potassium ferricyanide in the colorimetric reagent are both 0.1%~1.0%. After the finished buckwheat liquor is bottled, the reducing substances such as polyphenols and reducing sugars in the liquor will undergo a continuous and irreversible oxidation reaction in the trace oxygen environment inside the bottle, and their content will gradually decrease as the bottle storage time increases. The ferric ions provided by ferric chloride can be reduced to ferrous ions by the reducing substances in the liquor. The ferrous ions react with potassium ferricyanide to generate the characteristic blue-green Prussian blue product. The color depth is positively correlated with the content of reducing substances, and therefore forms a stable negative correlation with the bottle storage time. The above concentration range can ensure a clear color gradient, which is suitable for visual interpretation. The test paper formulation requires no pretreatment and has zero operational threshold, enabling rapid detection of bottle storage time.

[0013] For buckwheat liquor samples with different flavonoid contents, the determination of bottle storage time is based on the "relative change in color depth of samples in the same batch" rather than the absolute color value, which can completely eliminate the interference of flavonoid content differences on the test results. For the counterfeiting behavior of adding exogenous aldehydes to fake the age of base liquor, relying on the dual-channel dual verification rule, the addition of exogenous aldehydes can only change the color result of the base liquor channel, but cannot change the oxidation law of reducing substances in the bottle storage channel. The dual verification can identify this type of counterfeiting behavior 100%.

[0014] In some implementations, the color development reactions in steps S1 and S2 are carried out at room temperature of 15-35°C. The Ehrlich condensation reaction corresponding to the aging years of the base wine requires a certain amount of time to reach color stability; a reaction time of 2-5 minutes ensures sufficient color development while meeting the efficiency requirements of on-site testing. The Prussian blue coordination reaction corresponding to bottle aging time is fast, reaching color stability in 20-60 seconds, avoiding insufficient color development due to too short a reaction time and color deviation due to too long a reaction time. The room temperature range of 15-35°C covers most common application scenarios. When the temperature exceeds this range, correction can be made by adjusting the reaction time (the reaction time is extended by 30% for every 5°C decrease in temperature) to ensure stable test results.

[0015] In some embodiments, the base liquor vintage-color scale colorimetric card is prepared by processing a standard sample of buckwheat liquor base liquor with a known actual aging year through step S1, recording the color development results, and then color-calibrating it using the CIELab colorimetric system. The bottle aging time-color scale colorimetric card is prepared by processing a standard sample of finished buckwheat liquor with a known actual bottle aging time through step S2, recording the color development results, and then color-calibrating it using the CIELab colorimetric system. CIELab is an internationally recognized uniform color space that can effectively eliminate subjective color differences in human vision and color deviations caused by ambient light sources, ensuring the consistency and accuracy of colorimetric judgments across different batches and operating environments. It solves the shortcomings of traditional colorimetric cards, which are highly subjective and have large interpretation errors, and provides a standardized basis for visualization interpretation by non-professionals.

[0016] In some implementations, the comprehensive determination rule for step S3 is: If the aging year and bottling time of the base liquor are basically consistent with the product label information or the calculated value of the production date, the aging label is deemed to be true and reliable. If the aging age of the base liquor is significantly lower than the value stated on the product label, regardless of whether the bottling time matches, it will be judged as suspected false labeling of the base liquor's aging age and passing off inferior goods as superior ones. If the aging period of the base wine is basically consistent with the value on the product label, but the bottling time is significantly shorter than the value calculated from the production date, it is judged to be suspected of tampering with the production date or refilling (new wine in old bottles). If the aging period and bottle storage time of the base wine are both significantly lower than the values ​​stated on the product label, it is determined to be suspected of being a complete fraud. If the aging period of the base wine is significantly higher than the value stated on the product label, and the bottling time is basically consistent with the production date, it is judged as a questionable sample and further laboratory verification is required.

[0017] Among them, "basically consistent" refers to a deviation of ≤1 year between the test result and the product label value / production date calculated value; "significantly lower" refers to a test result that is ≥2 years lower than the product label value.

[0018] The aging process of the base liquor in ceramic jars takes place in an aerobic microporous environment, while the oxidation process in bottles takes place in a sealed, low-oxygen environment. The two processes are completely mutually exclusive in terms of space and reaction mechanism, and their time dimensions are orthogonal to each other. Counterfeiters cannot simultaneously simulate the color development results corresponding to two completely independent aging processes in the same liquor. This dual verification rule fundamentally raises the threshold for counterfeiting and can comprehensively cover various common vintage counterfeiting scenarios.

[0019] In some embodiments, the present invention also provides a rapid identification kit for visualizing the age of buckwheat liquor to implement the above-mentioned method, comprising a base liquor age detection unit, a flavonoid removal unit, a bottle storage time detection unit, and a matching colorimetric card assembly; the base liquor age detection unit is the aforementioned solid colorimetric strip containing p-toluenesulfonic acid and p-dimethylaminobenzaldehyde; the flavonoid removal unit is the aforementioned micro solid-phase extraction column filled with a mixed packing material of polyamide and uncapped C18, or uncapped C18 packing material; the bottle storage time detection unit is the aforementioned ferric chloride-potassium ferricyanide colorimetric test paper; the matching colorimetric card assembly includes a base liquor age-color scale colorimetric card and a bottle storage time-color scale colorimetric card. The kit standardizes and integrates all the core functional units required for detection, requiring no additional equipment or consumables, enabling out-of-the-box use, further reducing the operational threshold for non-professionals, and facilitating large-scale production and multi-scenario application.

[0020] In some embodiments, the kit further includes a transparent reaction tube, a quantitative sampler, and an instruction manual. The solid chromogenic slide is a round tablet in a sealed, light-proof package. The chromogenic system is a strip-shaped chromogenic test strip in a sealed, light-proof package. The micro solid-phase extraction column is a disposable solid-phase extraction column with a Luer connector. The sealed, light-proof packaging ensures the storage stability of the chromogenic reagent and extends the shelf life of the kit at room temperature. The extraction column with a Luer connector is compatible with conventional syringes, allowing for pretreatment operations without specialized equipment. The accompanying consumables and instruction manual provide standardized guidance for the entire process, ensuring stable test results for different operators.

[0021] The present invention has the following advantages over the prior art: This invention addresses the unique matrix characteristics of buckwheat liquor and the industry pain point of vintage fraud. It constructs a dual-channel colorimetric detection system with orthogonal dimensions of base liquor vintage and bottle aging time. Through a customized solid-phase extraction pretreatment scheme, it fundamentally solves the problem of flavonoid interference in the colorimetric detection background of buckwheat liquor. Employing a safe solid colorimetric sheet and test strip-type colorimetric system, it overcomes the safety drawbacks of traditional colorimetric reagents that cannot be publicly demonstrated on-site. Furthermore, based on the dual verification logic of two independent aging processes, it significantly raises the technical threshold for vintage fraud, enabling comprehensive identification of various covert fraudulent activities. Compared to existing technologies, this invention achieves a balance between detection accuracy, operational safety, result visualization, and scenario universality. No specialized equipment or training is required; non-professionals can quickly complete the entire detection process, filling the technological gap in on-site visualized vintage identification of buckwheat liquor. It provides a systematic and reliable solution for consumer rights protection, liquor company quality control, and rapid market supervision screening, possessing strong industrial promotion value and industry application significance. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: Preparation of a micro solid-phase extraction column This embodiment is used to prepare all types of solid-phase extraction columns covered by the claims, and a total of 4 parallel preparation examples are set up. The specific preparation steps are as follows: Preparation Example 1-1: Pure Uncapped C18 Packed Solid Phase Extraction Column Step 1: Select a 1 mL polypropylene solid-phase extraction empty column, pre-loaded with 20 μm polyethylene sieve plates at both ends; Step 2: Weigh 0.6g of unsealed C18 packing material with a pore size of 40-60μm and a pore size of 100Å, and pack it into an empty column using the dry packing method, controlling the compaction density to be 0.3g / mL; Step 3: Install sieve plates at both ends of the packing material to fix it, complete the column preparation, and dry and store at room temperature.

[0024] Preparation Example 1-2: Polyamide + Uncapped C18 Mixed Packing Solid Phase Extraction Column (1:1) Step 1: Select a 1 mL polypropylene solid-phase extraction empty column, pre-loaded with 20 μm polyethylene sieve plates at both ends; Step 2: Weigh 0.3g of 60-100 mesh polyamide and 0.3g of unsealed C18 filler in a 1:1 mass ratio. Mix them thoroughly and then pack them into an empty column using a dry packing method. The total packing amount is 0.6g, and the compaction density is controlled at 0.3g / mL. Step 3: Install sieve plates at both ends of the packing material to fix it, complete the column preparation, and dry and store at room temperature.

[0025] Preparation Examples 1-3: Polyamide + Uncapped C18 Mixed Packing Solid Phase Extraction Column (1:2) Step 1: Select a 1 mL polypropylene solid-phase extraction empty column, pre-loaded with 20 μm polyethylene sieve plates at both ends; Step 2: Weigh 0.2g of 60-100 mesh polyamide and 0.4g of unsealed C18 filler, with a mass ratio of 1:2. Mix them evenly and then fill the empty column using the dry packing method. The total filling amount is 0.6g, and the compaction density is controlled at 0.3g / mL. Step 3: Install sieve plates at both ends of the packing material to fix it, complete the column preparation, and dry and store at room temperature.

[0026] Preparation Examples 1-4: Preferred Three-Layer Solid-Phase Extraction Columns Step 1: Select a 1 mL polypropylene solid-phase extraction empty column, with a 20 μm polyethylene sieve plate pre-installed at the bottom. Step 2: Fill the layers of anhydrous sodium sulfate (0.1g), unsealed C18 filler (0.2g), and polyamide filler (0.3g) sequentially from bottom to top, for a total filling amount of 0.6g. Compact each layer of filler separately, controlling the overall compaction density to be 0.3g / mL. Step 3: Install a 20μm polyethylene sieve plate at the top of the packing material for fixation. Luer interfaces are reserved at both ends of the column to be compatible with standard syringes. The column preparation is completed. Store the column in a dry place at room temperature.

[0027] Performance verification steps Step 1: Take samples of 52% vol buckwheat liquor from the same batch and divide them into 4 groups, with a sample volume of 2 mL for each group; Step 2 Solid-phase extraction column activation and equilibration: First, activate the column with 2 mL of anhydrous ethanol at a flow rate of 1 mL / min, then equilibrate it with 2 mL of purified water at the same flow rate. Load the sample immediately after completion. Step 3: The corresponding group samples were treated with solid phase extraction columns prepared in Examples 1-1 to 1-4 respectively, and the flow rate through the column was controlled at 1 mL / min. The eluent was collected. Step 4: High performance liquid chromatography was used to detect the contents of total flavonoids, furfural, and ethyl palmitate in the original wine sample and the eluent of each group, respectively. Step 5: Calculate the total flavonoid removal rate, furfural recovery rate, and ethyl palmitate recovery rate for each group. The results are summarized in Table 1.

[0028] Table 1 Performance verification results of different solid phase extraction columns

[0029] Example 2: Preparation of p-Toluenesulfonic acid-p-dimethylaminobenzaldehyde solid chromogenic film This embodiment is used to prepare the full-proportion solid colorimetric tablets covered by the claims. A total of 3 parallel preparation examples are set up, and the specific preparation steps are as follows: Preparation Example 2-1: Low-ratio colorimetric slides (mass ratio 2:1) Step 1: Weigh the raw materials according to the formula: 10g of p-toluenesulfonic acid, 5g of p-dimethylaminobenzaldehyde, 84.5g of microcrystalline cellulose, and 0.5g of magnesium stearate. After passing all raw materials through a 100-mesh sieve, mix them evenly to obtain a mixed powder. The pharmaceutical filler accounts for 84.5%. Step 2: The mixed powder is compressed into tablets using a single-punch tablet press, with the compression pressure controlled at 5kN, to form round tablets with a diameter of 6mm and a tablet weight of 100mg. Step 3: Place the compressed tablets in a vacuum drying oven at 40°C for 2 hours. After drying, seal them in an aluminum foil bag to protect them from light and store them at room temperature.

[0030] Preparation Example 2-2: Optimal ratio of colorimetric tablets (mass ratio 4:1) Step 1: Weigh the raw materials according to the formula: 20g of p-toluenesulfonic acid, 5g of p-dimethylaminobenzaldehyde, 74.5g of microcrystalline cellulose, and 0.5g of magnesium stearate. After passing all raw materials through a 100-mesh sieve, mix them evenly to obtain a mixed powder. The pharmaceutical filler accounts for 74.5%. Step 2: The mixed powder is compressed into tablets using a single-punch tablet press, with the compression pressure controlled at 5kN, to form round tablets with a diameter of 6mm and a tablet weight of 100mg. Step 3: Place the compressed tablets in a vacuum drying oven at 40°C for 2 hours. After drying, seal them in an aluminum foil bag to protect them from light and store them at room temperature.

[0031] Preparation Example 2-3: High-ratio colorimetric slices (mass ratio 10:1) Step 1: Weigh the raw materials according to the formula: 50g of p-toluenesulfonic acid, 5g of p-dimethylaminobenzaldehyde, 44.5g of microcrystalline cellulose, and 0.5g of magnesium stearate. After passing all raw materials through a 100-mesh sieve, mix them evenly to obtain a mixed powder. The pharmaceutical filler accounts for 44.5%. Step 2: The mixed powder is compressed into tablets using a single-punch tablet press, with the compression pressure controlled at 5kN, to form round tablets with a diameter of 6mm and a tablet weight of 100mg. Step 3: Place the compressed tablets in a vacuum drying oven at 40°C for 2 hours. After drying, seal them in an aluminum foil bag to protect them from light and store them at room temperature.

[0032] Performance verification steps Step 1: Take the colorimetric slides from Preparation Examples 2-1 to 2-3 and test their disintegration time and colorimetric response time, respectively. Step 2: After storing each group of colorimetric slides in a sealed container at room temperature for 12 months, test their colorimetric activity retention rate (based on the colorimetric depth of newly prepared colorimetric slides under the same conditions). Step 3: All tests were performed in triplicate, and the average value was taken. The results are summarized in Table 2.

[0033] Table 2 Performance verification results of colorimetric tablets with different ratios

[0034] Example 3: Preparation of Ferric Chloride-Potassium Ferricyanide Colorimetric Test Paper This embodiment is used to prepare the full-concentration colorimetric test paper covered by the claims. A total of 3 parallel preparation examples were set up, and the specific preparation steps are as follows: Preparation Example 3-1: Low-concentration colorimetric test paper (0.1%) Step 1: Prepare the colorimetric reagent: Weigh 1g of ferric chloride and 1g of potassium ferricyanide, add purified water to make up to 1000mL, stir until completely dissolved, and obtain a mixed colorimetric reagent with a mass concentration of 0.1% for each component. Step 2 Take medium-speed qualitative filter paper (110 g / m²), cut it into 10 cm × 10 cm square pieces, and soak 10 sheets of filter paper for every 100 mL of colorimetric reagent at room temperature for 5 min. Step 3: Remove the impregnated filter paper and place it in a 60℃ forced-air drying oven for 10 minutes at a wind speed of 0.5m / s. After it is completely dry, cut it into strips of test paper measuring 5cm×1cm. Step 4: Place the cut test strips into an aluminum foil bag, seal it in a light-proof package, and store it at room temperature.

[0035] Preparation Example 3-2: Preferred Concentration Colorimetric Test Paper (0.5%) Step 1: Prepare the colorimetric reagent: Weigh 5g of ferric chloride and 5g of potassium ferricyanide, add purified water to make up to 1000mL, stir until completely dissolved, and obtain a mixed colorimetric reagent with a mass concentration of 0.5% for each component. Step 2 Take medium-speed qualitative filter paper (110 g / m²), cut it into 10 cm × 10 cm square pieces, and soak 10 sheets of filter paper for every 100 mL of colorimetric reagent at room temperature for 5 min. Step 3: Remove the impregnated filter paper and place it in a 60℃ forced-air drying oven for 10 minutes at a wind speed of 0.5m / s. After it is completely dry, cut it into strips of test paper measuring 5cm×1cm. Step 4: Place the cut test strips into an aluminum foil bag, seal it in a light-proof package, and store it at room temperature.

[0036] Preparation Example 3-3: High-concentration colorimetric test paper (1.0%) Step 1: Prepare the colorimetric reagent: Weigh 10g of ferric chloride and 10g of potassium ferricyanide, add purified water to make up to 1000mL, stir until completely dissolved, and obtain a mixed colorimetric reagent with a mass concentration of 1.0% for each component. Step 2 Take medium-speed qualitative filter paper (110 g / m²), cut it into 10 cm × 10 cm square pieces, and soak 10 sheets of filter paper for every 100 mL of colorimetric reagent at room temperature for 5 min. Step 3: Remove the impregnated filter paper and place it in a 60℃ forced-air drying oven for 10 minutes at a wind speed of 0.5m / s. After it is completely dry, cut it into strips of test paper measuring 5cm×1cm. Step 4: Place the cut test strips into an aluminum foil bag, seal it in a light-proof package, and store it at room temperature.

[0037] Performance verification steps Step 1: Take the colorimetric test strips from Preparation Examples 3-1 to 3-3 and test the colorimetric response time and colorimetric stability time, respectively. Step 2: After storing each group of test strips at room temperature in a sealed container for 12 months, test their color activity retention rate (based on the color depth of newly prepared test strips under the same conditions). Step 3: All tests were performed in triplicate, and the average value was taken. The results are summarized in Table 3.

[0038] Table 3 Performance verification results of colorimetric test strips at different concentrations

[0039] Example 4: Preparation of Standard Colorimetric Card This embodiment is used to prepare a base wine vintage-color scale comparison card and a bottle aging time-color scale comparison card. The specific preparation steps are as follows: Step 1: Standard sample collection: Collect standard samples of 3-year, 5-year, 8-year, 12-year, and 15-year tartary buckwheat base liquor with complete records of aging in earthenware jars, as well as standard samples of finished tartary buckwheat liquor from the same batch with complete storage records and bottle storage times of 0 months, 3 months, 6 months, 12 months, and 24 months, respectively. Step 2 Standard color development treatment: All base wine standards were treated with solid phase extraction columns (after activation and equilibration) as described in Examples 1-4 to remove flavonoids. The color development sheets from Examples 2-2 were added and reacted at room temperature for 3 minutes to obtain standard color development solutions for each year. All bottle-aged standards were treated with color development test paper as described in Examples 3-2. After adding the sample, the paper was allowed to stand for 30 seconds to obtain standard color development test paper for each bottle-aged time. Step 3: Color Acquisition and Calibration: Under a standard D65 light source, use a digital camera with fixed parameters to photograph the color development results of all standard color developing solutions and standard color developing test strips. Measure the L value of each standard's color development result using a CIELab colorimeter. a b Values ​​that specify the color range corresponding to each year / bottle storage time; Step 4: Printing and Preparation: Based on the calibrated standard color scale, print a colorimetric card on coated paper, marking the corresponding year / bottling storage time range and colorimetric reference value to complete the preparation of the standard colorimetric card.

[0040] Verification results of colorimetric parameters of standard colorimetric card Table 4. Base Wine Vintage - Color Scale Comparison Chart Standard Colorimetric Parameters

[0041] Table 5 Bottle Storage Time - Standard Colorimetric Parameters of Colorimetric Chart

[0042] Example 5: Testing of Authentic and Compliant Buckwheat Wine Samples Sample Information A certain brand of compliant buckwheat liquor is labeled as having an 8-year base liquor age, with a production date of January 2024 on the bottle. During testing, the bottle storage time was calculated to be 25 months based on the production date, with an alcohol content of 52% vol, and the production batch is traceable.

[0043] Detection steps Step 1 Sample preparation: Shake the wine sample to be tested well and divide it into two portions: Sample A (2mL) and Sample B (1mL). Step 2 Solid-phase extraction column activation and equilibration: First, activate the column with 2 mL of anhydrous ethanol at a flow rate of 1 mL / min, then equilibrate it with 2 mL of purified water at the same flow rate. Load the sample immediately after completion. Step 3: First channel base wine vintage detection: Use the matching syringe to draw 2 mL of sample A and slowly push it through the three-layer solid phase extraction column at a speed of 1 mL / min. Collect the effluent in a transparent reaction tube to obtain the flavonoid removal solution; add one optimal ratio colorimetric tablet to the reaction tube, gently shake to dissolve, and react at room temperature for 3 min. Step 4: Second channel bottle storage time test: Take sample B, drop 2 drops onto the preferred concentration colorimetric test paper, and let stand at room temperature for 30 seconds; Step 5: Colorimetric Comparison and Comprehensive Judgment: Compare the color of the reaction solution in Step 3 and the color of the test strip in Step 4 with the corresponding standard colorimetric card, and make a comprehensive judgment based on the product labeling information.

[0044] Summary of test results Table 6 Summary of Test Results for Real and Compliant Samples

[0045] Comprehensive judgment The vintage and aging time of the base wine in this sample are basically consistent with the product label information and the calculated production date, so the vintage label is determined to be true and reliable.

[0046] Example 6: Detection of Samples with Falsely Labeled Vintage of Base Wine Sample Information A batch of buckwheat liquor purchased from an e-commerce platform was labeled as having a base liquor age of 10 years, with a production date of June 2025 on the bottle. During testing, the bottle storage time was calculated to be 9 months based on the production date, and the alcohol content was 48% vol. After tracing, it was confirmed that the actual age of the base liquor was 3 years.

[0047] Detection steps The detection steps are completely consistent with those in Example 5.

[0048] Summary of test results Table 7 Summary of Detection Results for Falsely Labeled Samples

[0049] Comprehensive judgment The aging age of the base liquor in this sample was significantly lower than the value stated on the product label, and the bottle storage time was basically consistent with the calculated value of the production date. It was determined that the sample was suspected of falsely labeling the aging age of the base liquor and passing off inferior products as superior ones.

[0050] Example 7: Testing of samples of new wine in old bottles (refilling) Sample Information The buckwheat liquor acquired from the secondhand market has a bottle labeled as having a 15-year base liquor vintage, but no clear production date. After tracing its origin, it was confirmed that the bottle is an authentic used bottle, while the liquor itself is a recently refilled bottle with a bottling time of less than 3 months.

[0051] Detection steps The detection steps are completely consistent with those in Example 5.

[0052] Summary of test results Table 8 Summary of Test Results for Samples of New Wine in Old Bottles

[0053] Comprehensive judgment The aging period of the base wine in this sample was basically consistent with the product label, but the bottle aging time was significantly shorter than the reasonable bottle aging time. It was determined that the sample was suspected of tampering with the production date and refilling (new wine in old bottles). Example 8: Adaptation Verification for Different Column Flow Rates Verification steps Step 1: Take samples of 52% vol buckwheat liquor from the same batch and divide them into 3 groups, with a sample volume of 2 mL for each group; Step 2: The samples were processed at column flow rates of 0.8 mL / min, 1.0 mL / min, and 1.2 mL / min, respectively, and the remaining detection conditions were completely consistent with those in Example 5. Step 3: Detect the total flavonoid removal rate, furfural recovery rate, and base wine vintage determination results for each group. The results are summarized in Table 9.

[0054] Table 9. Adaptation verification results for different column flow velocities

[0055] Example 9: Verification of Adaptation to Different Colorimetric Reaction Times Verification steps Step 1: Take samples of 52% vol buckwheat liquor from the same batch and divide them into 3 groups, with a sample volume of 2 mL for each group; Step 2: The color development reaction of the base wine was set for 2 min, 3 min, and 5 min, respectively; the color development reaction of the bottle storage was set for 20 s, 30 s, and 60 s, respectively; the remaining detection conditions were completely consistent with those in Example 5. Step 3: Record the color development stability and year determination results for each group. The results are summarized in Table 10.

[0056] Table 10. Results of adaptation verification for different colorimetric reaction times

[0057] Example 10: Compatibility Verification of Buckwheat Liquor with Different Alcohol Contents Verification steps Step 1: Take real-year buckwheat liquor samples with 42% vol, 45% vol, 48% vol, and 52% vol respectively. The real-year age of the base liquor is 8 years and the bottle storage time is 24 months. Step 2: Process each group of samples using the same detection procedure as in Example 5; Step 3: Record the year determination results for each group, and summarize the results in Table 11.

[0058] Table 11 Compatibility verification results of samples with different alcohol contents

[0059] Example 11 Rapid Identification Kit for Visualizing the Vintage of Buckwheat Liquor reagent kit composition This kit is used to implement the detection method according to any one of claims 1-8, and the complete set of components includes: 1. Base wine vintage detection unit: solid colorimetric slides prepared in Example 2-2, 10 slides / aluminum foil bag sealed packaging, and one base wine vintage-color scale comparison card prepared in Example 4; 2. Flavonoid removal unit: Disposable three-layer solid-phase extraction columns prepared in Examples 1-4, 10 columns individually packaged; 3. Bottle storage time detection unit: 10 colorimetric test strips prepared in Example 3-2, sealed in an aluminum foil bag, and one bottle storage time-color scale colorimetric card prepared in Example 4; 4. Supporting consumables: 10 x 2mL disposable syringes, 10 x 5mL transparent reaction tubes, and 10 x quantitative droppers; 5. One instruction manual, which specifies the entire operation process, comprehensive judgment rules, and precautions.

[0060] Reagent kit preparation and packaging Step 1: All components were packaged in a dry environment at room temperature. Solid colorimetric tablets and colorimetric test strips were sealed in light-proof aluminum foil bags. Step 2: All components are packed into a cardboard outer box according to a fixed layout, and the inside is secured with cardboard partitions to prevent damage to the components during transportation; Step 3: Label the outer packaging box with the product name, storage conditions, expiration date, and production batch number to complete the reagent kit preparation.

[0061] Performance verification steps Step 1: Store the prepared reagent kit at room temperature away from light, and take samples at 0 months, 3 months, 6 months and 12 months to test the performance indicators of each component; Step 2: The three groups of blind samples from Examples 5-7 were tested using the kit to verify the detection accuracy. The results are summarized in Table 12.

[0062] Table 12 Reagent kit performance validation results

[0063] Verification conclusions After being stored at room temperature and protected from light for 12 months, the performance of each component of this kit does not significantly degrade, the blind sample detection accuracy is 100%, and the shelf life is ≥12 months, which can stably realize the detection function of this invention.

[0064] Example 12 Method Repeatability Verification Verification steps Step 1: Select 3 operators without professional testing background to conduct parallel tests on the same sample of Example 5 at three different ambient temperatures of 15℃, 25℃, and 35℃. Step 2: All tests were conducted using the same procedures as in Example 5, with each operator performing three parallel experiments at each temperature. Step 3: Calculate the relative standard deviation (RSD) of the test results to verify the repeatability and resistance to environmental interference of the method. The results are summarized in Table 13.

[0065] Table 13 Results of Method Repeatability Validation

[0066] Verification conclusions The overall relative standard deviation of the method of this invention is ≤3%, which is not affected by the professional background of the operator or the fluctuation of normal ambient temperature. It has good repeatability, strong anti-interference ability, and can be operated stably by non-professionals.

[0067] Example 13 Compatibility Verification of Different Types of Buckwheat Liquor Verification steps Step 1: Take samples of commercially available green buckwheat (5 years), golden buckwheat (6 years), and black buckwheat (7 years) buckwheat liquor of real vintages, and store them in bottles for 24 months. Step 2: Process each group of samples using the same detection procedure as in Example 5; Step 3: Detect the flavonoid removal rate and year determination results for each group. The results are summarized in Table 14.

[0068] Table 14 Adaptation verification results of samples with different flavonoid contents

[0069] Verification conclusions The pretreatment scheme of this invention can achieve efficient removal of different types of buckwheat wine, with accurate detection results and strong adaptability.

[0070] Comparative Example 1: Ehrlich reaction control using existing concentrated sulfuric acid system Comparison Plan The conventional concentrated sulfuric acid-p-dimethylaminobenzaldehyde colorimetric system of the prior art was used instead of the solid colorimetric tablet of the present invention. The other detection conditions and samples were completely consistent with those in Example 5. The specific colorimetric steps were as follows: 0.5 mL of concentrated sulfuric acid-p-dimethylaminobenzaldehyde colorimetric solution (containing 2% p-dimethylaminobenzaldehyde in 10% concentrated sulfuric acid ethanol solution) was added to the flavonoid removal solution, shaken well, and reacted at room temperature for 3 min.

[0071] Performance verification steps Step 1: Compare the operational safety, color development stability, storage stability, and on-site operational feasibility of Embodiment 5 of the present invention with that of the comparative example; Step 2: Test the accuracy of the color development results and year determination for the two groups. The results are summarized in Table 15.

[0072] Table 15 Comparison results of the present invention scheme and the concentrated sulfuric acid system

[0073] Comparison Conclusion The solid colorimetric sheet system of this invention not only overcomes the safety risks of concentrated sulfuric acid systems, but also achieves better colorimetric stability and shelf life, solving the long-standing technical prejudice in the field that "Ehrlich reaction cannot be safely demonstrated on-site", and achieving unexpected technical effects.

[0074] Comparative Example 2: Single Polyamide Packed Solid Phase Extraction Column Control Comparison Plan The single polyamide-filled solid-phase extraction column of Preparation Example 1-1 was used instead of the three-layer solid-phase extraction column of the present invention, and the other detection conditions and samples were completely consistent with those of Example 5.

[0075] Performance verification steps Step 1: Compare the flavonoid removal rate and aging marker recovery rate of Example 5 of the present invention with those of the comparative example; Step 2: Test the vintage determination results of the base wines in the two groups. The results are summarized in Table 16.

[0076] Table 16 Comparison results of the present invention with single polyamide filler

[0077] Comparison Conclusion The filler combination scheme of the present invention achieves a high recovery rate of aging markers while maintaining a high flavonoid removal rate, solving the industry problem of "the inability to simultaneously achieve flavonoid removal and target analyte retention" in the prior art. The effect is something that those skilled in the art cannot expect through conventional filler selection, and it is not a simple application of conventional technical means.

[0078] Comparative Example 3: Conventional C18 End-Cap Packing Comparison Plan A solid-phase extraction column was prepared using conventional end-capped C18 packing material instead of the unend-capped C18 packing material of the present invention. The other detection conditions and samples were completely consistent with those in Example 5.

[0079] Performance verification steps Step 1: Compare the recovery rates of long-chain fatty acid ethyl esters in Example 5 of this invention with those in this comparative example; Step 2: Test the vintage determination results of the base wines in the two groups. The results are summarized in Table 17.

[0080] Table 17 Comparison results of the present invention's solution with conventional C18 end-capping packing

[0081] Comparison Conclusion The uncapped C18 packing material used in this invention has been specifically optimized for the retention characteristics of aging markers. Compared with conventional capped C18 packing material, it has achieved an unexpectedly high recovery rate, and is not a simple replacement of conventional packing material.

[0082] Comparative Example 4: Single Base Wine Vintage Detection Channel Comparison Comparison Plan Only the first channel of the present invention is used for base wine vintage detection, omitting the second channel for bottle storage time detection. The remaining detection conditions and samples are completely consistent with those in Examples 5-7.

[0083] Performance verification steps Step 1: Select 50 blind samples with known real information (including 25 fake samples and 25 compliant samples), and conduct detection using the dual-channel system of this invention and the single-channel system of this comparative example, respectively; Step 2: Calculate the identification rate and false positive rate of the counterfeit samples in the two groups. The results are summarized in Table 18.

[0084] Table 18 Comparison results of the dual-channel system and the single-channel system of the present invention

[0085] Comparison Conclusion The dual-channel dual-verification system of this invention improves the counterfeit detection rate by 48.0% compared with single-channel detection, achieving a synergistic anti-counterfeiting effect of 1+1>2. It is not a simple superposition of two detection methods, but has achieved unexpected technical results.

[0086] Comparative Example 5: Control of Flavonoid Removal Procedures Comparison Plan The flavonoid removal step was omitted, and the base liquor color reaction was carried out directly using the original buckwheat liquor solution. The other detection conditions and samples were completely consistent with those in Example 5.

[0087] Performance verification steps Step 1: Compare the color development results and the accuracy of year determination between Example 5 of the present invention and this comparative example; Step 2: Record the interference of the flavonoid background color on the color development results. The results are summarized in Table 19.

[0088] Table 19 Comparison results of the present invention's scheme and the flavonoid-free removal process

[0089] Comparison Conclusion The proprietary pretreatment step of this invention is the core key to solving the interference of flavonoid background color in buckwheat wine, and completely solves the industry pain point that existing colorimetric methods cannot be applied to the detection of buckwheat wine.

[0090] Comparative Example 6: Control of Conventional Reducing Substance Detection System Comparison Plan The Fehling's reagent system, which is commonly used in the food industry, was used instead of the ferric chloride-potassium ferricyanide colorimetric system of this invention. All other detection conditions and samples were completely consistent with those in Example 5.

[0091] Performance verification steps Step 1: Compare the colorimetric response speed, alcohol matrix anti-interference ability, and colorimetric gradient clarity of Example 5 of the present invention with those of the comparative example. Step 2: Test the accuracy of the bottle storage time determination for both groups. The results are summarized in Table 20.

[0092] Table 20 Comparison results of the present invention scheme with the conventional Fehling's reagent system

[0093] Comparison Conclusion The ferric chloride-potassium ferricyanide system selected in this invention has been specifically optimized for the needs of high-alcohol matrix in baijiu and rapid on-site detection. Compared with conventional reducing substance detection systems, it has achieved unexpected detection results, which is not a simple application of conventional technical methods.

[0094] In summary, the above embodiments fully verify the feasibility, stability, and adaptability of the technical solution of the present invention. They fully cover all technical aspects, including the preparation of core functional materials, the whole process detection of the aging of buckwheat wine, the adaptation of multi-dimensional parameters, the implementation of reagent kit products, and the verification of method repeatability. Those skilled in the art can completely repeat the technical solution of the present invention without creative labor, based solely on the content disclosed in this specification, thus fully meeting the statutory requirements of the Patent Law regarding the full disclosure of the specification.

[0095] The above comparative examples, through univariate parallel comparisons, specifically verified the unexpected technical effects brought about by the core technical means of this invention: the customized solid-phase extraction system of this invention solves the industry pain point that existing technologies cannot simultaneously address the removal of flavonoids and the retention of aging markers; the solid colorimetric plate system overcomes long-standing technical biases in the field, enabling safe on-site application of the Ehrlich reaction; the dual-channel dual-verification architecture achieves a synergistic anti-counterfeiting effect of 1+1>2, which is not a simple superposition of existing technologies. Simultaneously, it verifies that this invention has good adaptability to buckwheat wines with different alcohol contents, aroma types, and flavonoid contents. Non-professionals can complete the entire process of testing within 5 minutes, completely solving the core defects of existing detection methods described in the background art. This fully demonstrates that this invention possesses outstanding substantive features and significant technical progress, fully achieving the intended purpose of the invention.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rapid visual identification method for the vintage of buckwheat liquor based on a dual-channel colorimetric reaction, characterized in that, Includes the following steps: S1 Base Wine Aging Age Detection: Take the buckwheat wine sample to be tested and pass it through a micro solid-phase extraction column filled with a mixture of polyamide and uncapped C18 packing material or uncapped C18 packing material to remove flavonoid interference substances. The buckwheat wine sample to be tested is passed through the micro solid-phase extraction column at a flow rate of 0.8~1.2mL / min, and the flavonoid removal solution is collected. Add a solid colorimetric tablet containing p-toluenesulfonic acid and p-dimethylaminobenzaldehyde to the flavonoid removal solution to carry out a colorimetric reaction. The reaction time is 2~5 minutes. The color of the solution after the reaction is compared with the pre-prepared base wine age-color scale color chart to determine the base wine aging age or age range of the sample to be tested. S2 Finished Wine Bottle Storage Time Test: Take another sample of buckwheat wine to be tested. No pretreatment is required. The color reaction is carried out directly using the ferric chloride-potassium ferricyanide color development system. The reaction time is 20-60 seconds. Utilizing the negative correlation between color depth and bottle storage time, the color development result after the reaction is compared with the pre-made bottle storage time-color scale comparison card to determine the bottle storage time or time range of the sample to be tested. S3 Dual Verification Comprehensive Judgment: The aging year of the base wine obtained in step S1 and the bottling time obtained in step S2 are compared with the labeling information of the buckwheat wine product to be tested, and the authenticity of the product's year label is comprehensively judged.

2. The method according to claim 1, characterized in that, The packing material of the micro solid phase extraction column is a mixture of polyamide and uncapped C18, with a mass ratio of 1:0.5~2 and a total packing amount of 0.2~1.0g.

3. The method according to claim 2, characterized in that, After treatment with a micro solid-phase extraction column, the recovery rate of aging markers in the wine is ≥80%.

4. The method according to claim 1, characterized in that, In the solid chromogenic tablet, the mass ratio of p-toluenesulfonic acid to p-dimethylaminobenzaldehyde is 2:1 to 10:

1. The solid chromogenic tablet is formed by compression molding with pharmaceutical filler, and the pharmaceutical filler accounts for 80% to 90% of the total mass of the tablet.

5. The method according to claim 1, characterized in that, The ferric chloride-potassium ferricyanide colorimetric system is a colorimetric test paper prepared by impregnating the colorimetric reagent and then drying it. The mass concentration of ferric chloride and potassium ferricyanide in the colorimetric reagent is 0.1%~1.0%.

6. The method according to claim 1, characterized in that, The colorimetric reactions in steps S1 and S2 were carried out at room temperature (15-35°C).

7. The method according to claim 1, characterized in that, The base liquor vintage-color scale colorimetric card is prepared by reacting a standard sample of buckwheat liquor base liquor with a known actual aging year through step S1, recording the color development results, and then color-calibrating it using the CIELab colorimetric system; the bottle storage time-color scale colorimetric card is prepared by reacting a standard sample of finished buckwheat liquor with a known actual bottle storage time through step S2, recording the color development results, and then color-calibrating it using the CIELab colorimetric system.

8. The method according to claim 1, characterized in that, The comprehensive judgment rule for step S3 is as follows: If the aging year and bottling time of the base liquor are basically consistent with the product label information or the calculated value of the production date, the aging label is deemed to be true and reliable. If the aging age of the base liquor is significantly lower than the value stated on the product label, regardless of whether the bottling time matches, it will be judged as suspected false labeling of the base liquor's aging age and passing off inferior goods as superior ones. If the aging period of the base wine is basically consistent with the value on the product label, but the bottling time is significantly shorter than the value calculated from the production date, it is judged to be suspected of tampering with the production date or refilling (new wine in old bottles). If the aging period and bottle storage time of the base wine are both significantly lower than the values ​​stated on the product label, it is determined to be suspected of being a complete fraud. If the aging period of the base wine is significantly higher than the value stated on the product label, and the bottling time is basically consistent with the production date, it is judged as a questionable sample and further laboratory verification is required.

9. A rapid identification kit for visualizing the age of buckwheat liquor for implementing the method of any one of claims 1-8, characterized in that, Includes a base wine vintage detection unit, a flavonoid removal unit, a bottle storage time detection unit, and a matching colorimetric card assembly; The base wine vintage detection unit is the solid colorimetric sheet containing p-toluenesulfonic acid and p-dimethylaminobenzaldehyde as described in claim 1 or 4. The flavonoid removal unit is a micro solid phase extraction column filled with a mixture of polyamide and uncapped C18 as described in any one of claims 1-2, or an uncapped C18 packing. The bottle storage time detection unit is the ferric chloride-potassium ferricyanide colorimetric test paper as described in claim 1 or 5; The matching colorimetric card components include a base wine vintage-color scale colorimetric card and a bottle aging time-color scale colorimetric card.

10. The reagent kit according to claim 9, characterized in that, It also includes a transparent reaction tube, a quantitative sampler, and an instruction manual; the solid colorimetric tablet is a round tablet in a sealed, light-proof package; the colorimetric test paper is a strip test paper in a sealed, light-proof package; the micro solid-phase extraction column is a disposable solid-phase extraction column with a Luer interface and a total filling amount of 0.5g.

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