Eucommia ulmoides Baijiu brewing method

Abstract

The invention discloses a brewing method of eucommia ulmoides Baijiu. On the basis of a traditional Baijiu fermentation process, debittered eucommia ulmoides leaves are innovatively added as a conventional starter propagation raw material. And the obtained base liquor, lactic acid bacteria and the like are subjected to bidirectional fermentation, so that the liquor is endowed with unique eucommia ulmoides flavor. Effective components of eucommia ulmoides are extracted through a molecular distillation technology to obtain eucommia ulmoides refined liquid, and the eucommia ulmoides refined liquid and fermented eucommia ulmoides flavored white spirit are compounded and blended according to the golden proportion of 1: 3, so that the novel eucommia ulmoides white spirit with the traditional Maotai-flavor style and the characteristic faint scent of eucommia ulmoides is finally prepared. The obtained Baijiu keeps the clarity of the Baijiu body, the health care value of the Baijiu is remarkably improved, and a technical normal form is provided for innovative application of medicinal and edible raw materials in the field of Baijiu.

Description

Technical Field

[0001] The present invention belongs to the technical field of Baijiu brewing, and particularly relates to a method for brewing Eucommia ulmoides Oliv. Baijiu. Background Art

[0002] The sauce-flavored Baijiu body has a remarkable ability to carry herbaceous active ingredients, and it can promote the decomposition of plant polysaccharides and the release of small-molecule functional substances in a high-temperature fermentation environment. Eucommia ulmoides Oliv. is a traditional Chinese medicinal material with the effects of tonifying the liver and kidney, strengthening tendons and bones, and lowering blood pressure. Modern pharmacology has confirmed that the active ingredients in Eucommia ulmoides Oliv., such as chlorogenic acid and pinoresinol diglucoside, have antioxidant, anti-fatigue, and immunomodulatory effects. However, traditional Eucommia ulmoides Oliv. wine mostly uses light-flavored or strong-flavored Baijiu as the base wine. Due to the short fermentation cycle and low microbial diversity, the extraction of active ingredients from Eucommia ulmoides Oliv. is insufficient, and the flavor of the Baijiu body and the medicinal fragrance of Eucommia ulmoides Oliv. are difficult to be harmoniously integrated. To solve the above problems, the present invention proposes a method for preparing Eucommia ulmoides Oliv. wine based on the sauce-flavored process framework, filling the gap in the technical field of functional sauce-flavored Baijiu. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for brewing Eucommia ulmoides Oliv. Baijiu. By adding Eucommia ulmoides Oliv. leaves with the bitter and astringent taste removed to the traditional Baijiu brewing, the base wine is initially obtained. Then, using the two-way fermentation technology, three kinds of lactic acid bacteria, such as Lactobacillus plantarum, Lactobacillus acidophilus, and Lactococcus lactis, are combined to obtain Baijiu with the flavor of Eucommia ulmoides Oliv. This process improves the taste of the Baijiu body and enhances the transparency. Finally, the Eucommia ulmoides Oliv. essence is extracted by molecular distillation technology to ensure the efficient retention of chlorogenic acid and sauce-flavored pyrazine substances. The Eucommia ulmoides Oliv. essence is blended with the fermented flavored Baijiu in a ratio of 1:3 to further increase the unique aroma of Eucommia ulmoides Oliv. in the Baijiu body, and at the same time ensure the efficient retention of beneficial components such as chlorogenic acid, so as to achieve the health care effect.

[0004] To achieve the above purpose, the technical solution of the present invention is as follows:

[0005] A method for brewing Eucommia ulmoides Oliv. Baijiu, the method comprising the following steps:

[0006] (1) Treatment of Eucommia ulmoides Oliv. leaves: The harvested Eucommia ulmoides Oliv. leaves are subjected to decolorization and enzymatic hydrolysis treatment;

[0007] (2) Preparation of base wine: By mass percentage, 25-35% of Eucommia ulmoides Oliv. leaves, 50-60% of sorghum, and 10-15% of wheat are mixed, and then soaked twice in warm water at 45-55 °C for 1 hour, and then subjected to cooking, saccharification, fermentation, and distillation to obtain a transparent base wine;

[0008] (3) Two-way fermentation: The base wine obtained in step (2) is added with Saccharomyces cerevisiae, and the cell suspension concentration of the Saccharomyces cerevisiae is 10 7CFU / mL; primary fermentation is carried out in a fermenter at a fermentation temperature of 25 - 30 °C. When the alcohol content reaches 9.5% (v / v), lactic acid bacteria are added, and the concentration of the lactic acid bacteria is 10 5 ~10 7 CFU / mL, and secondary fermentation is started and carried out at 18 - 25 °C for 72 hours;

[0009] (4) Compound flavoring: Extract the eucommia ulmoides essence liquid under the condition of 80 - 90 °C by using a molecular distillation device. Finally, the flavored liquor and the eucommia ulmoides essence liquid are modulated according to a volume ratio of 3:1 to obtain eucommia ulmoides liquor.

[0010] Preferably, the harvesting method of the eucommia ulmoides leaves in step (1) is: select the young leaves in May - July, after blanching treatment, dry them at 65 °C. The decolorization method is: soak them in 30% brine for 12 hours to remove chlorophyll and impurities; then soak them in 1.5% citric acid solution with a pH of 4.5 - 5.5 for 2 - 3 hours, specifically: soak them at 5 gradients of pH 4.5, 4.8, 5.0, 5.2, and 5.5 respectively, soak for 30 minutes at each gradient to further remove chlorophyll and eliminate the bitter taste. The enzymolysis method is: treat the eucommia ulmoides leaves with 0.2% cellulase and 0.1% pectinase at 40 °C for 4 hours to decompose fibers and pectin and release active ingredients.

[0011] Preferably, the lactic acid bacteria in step (3) are Lactobacillus plantarum, Lactobacillus acidophilus, and Lactococcus lactis mixed in a weight ratio of 1:1:1, and the pH value in the fermenter is controlled at 6.8.

[0012] Among them, in step (4), the specific steps for extracting the eucommia ulmoides essence liquid can be:

[0013] (1) Raw material pretreatment

[0014] Collect fresh eucommia ulmoides leaves, remove impurities and rinse with water, dry them at 50 °C hot air until the moisture content ≤ 8%; crush them through an 80 - mesh sieve to obtain a uniform powder; add a compound enzyme (the compound enzyme is a mixture of cellulase and pectinase in a mass ratio of 1:1) according to a mass ratio of 1:100, carry out enzymolysis at 40 °C for 2 hours, inactivate the enzyme and then centrifuge to take the supernatant;

[0015] (2) Primary extraction

[0016] Use a supercritical CO2 extraction instrument for extraction, and the parameters are as follows:

[0017] Supercritical CO2 extraction parameters: the pressure is 25 - 30 MPa, and the temperature is 40 - 45 °C;

[0018] CO2 flow rate: 20 - 25 L / h, and the extraction time is 2 - 3 hours;

[0019] Separation kettle pressure: 5 - 6 MPa, temperature: 30 °C;

[0020] Low - temperature ethanol extraction: ethanol concentration is 70%, solid - liquid ratio is 1:15, ultrasonic - assisted extraction at 40 °C for 1 hour;

[0021] (3) Molecular distillation purification

[0022] Use a molecular distillation device for extraction, with the following parameters:

[0023] The first - stage distillation is used to remove heavy impurities. Set the evaporation temperature: 60 - 70 °C, system pressure: 10 - 50 Pa; scraping film rotation speed: 200 - 250 rpm, feed rate: 1.0 - 1.5 mL / min;

[0024] The second - stage distillation is used to enrich flavor substances. Set the evaporation temperature: 80 - 90 °C, system pressure: 1 - 5 Pa; condensation temperature: - 10 °C, light - component collection rate > 85%;

[0025] Low - temperature concentration: Rotary evaporation, set the evaporation temperature at 95 °C, system pressure is - 0.09 MPa.

[0026] Advantages of the present invention:

[0027] 1. Step - by - step soaking process: Innovatively adopt pH - gradient regulation combined with gradient - temperature treatment to synchronously solve the problems of removing the bitter and astringent taste of Eucommia ulmoides leaves and chlorophyll removal, laying a pure and odor - free raw material foundation for the subsequent brewing process.

[0028] 2. Two - way fermentation: Introduce microorganisms such as lactic acid bacteria, and adopt two - way fermentation to enhance the flavor of Eucommia ulmoides wine. In the aerobic fermentation stage, polyphenol substances in Eucommia ulmoides leaves help improve the esterification efficiency, realizing the coordinated generation of acidity control and flavor substances; in the anaerobic fermentation stage, by precisely regulating the fermentation conditions, further promote the formation and accumulation of Eucommia ulmoides flavor substances, making the wine body flavor more abundant.

[0029] 3. Molecular distillation coupling technology: Breakthroughly retain the active ingredients of Eucommia ulmoides (such as the retention rate of pinoresinol diglucoside > 92%), greatly enhancing the health care value and functionality of the finished wine.

[0030] 4. Health function enhancement: This high - level chlorogenic acid content not only endows the wine with significant health care functions, such as antioxidant and immune regulation, but also effectively increases the added value of the product, has good health care functions, and meets consumers' demands for healthy beverages.

[0031] 5. Flavor enhancement and nutrition improvement: Add Eucommia ulmoides essence to the fermented Eucommia ulmoides wine to further improve the flavor level of the wine body, making its taste more mellow and delicate. At the same time, re - strengthen the nutritional components in the wine, achieving a double improvement in flavor and nutrition.

[0032] 6. High market promotion value: The Eucommia ulmoides wine prepared by the present invention not only has high nutritional value, unique flavor and excellent taste, but also has high promotion value and commercial potential in the healthy drink market due to its remarkable health care effects, and can meet the needs of consumers for high-quality and multi-functional wine products. Brief Description of the Drawings

[0033] Figure 1 It is a flow chart of a brewing method of Eucommia ulmoides white wine of the present invention. Detailed Embodiments

[0034] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer with the description. However, the specific experimental methods involved in the following embodiments are all conventional methods or are carried out according to the conditions recommended in the manufacturer's instructions unless otherwise specified.

[0035] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. The test methods in the following embodiments are all conventional methods unless otherwise specified. Unless otherwise specified, the reagents and materials used can be obtained by purchasing from the market.

[0036] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred implementation methods and materials described herein are for illustrative purposes only.

[0037] Embodiment 1 A brewing method of Eucommia ulmoides white wine

[0038] (1) Obtain Eucommia ulmoides leaf base wine

[0039] Raw material ratio

[0040] Sorghum (50 - 60%): As the main raw material, glutinous sorghum (branched chain starch ≥ 88%) is recommended to improve the fermentation efficiency.

[0041] Wheat (10 - 15%): Used for making koji to provide yeast and enzymes required for fermentation.

[0042] Eucommia ulmoides leaves (25 - 35%): Used to enhance the flavor and efficacy of white wine.

[0043] Water (appropriate amount): The amount of water is about 2.5 times that of the raw materials, and is used for moistening grains, fermentation and steaming.

[0044] Core process improvement process

[0045] Pretreatment of Eucommia ulmoides leaves

[0046] Harvesting: Select young leaves in May - July, conduct fixation treatment, and then dry at a low temperature of 65°C.

[0047] Decolorization: Soak in 30% brine for 12 hours to remove chlorophyll and impurities. Then soak in 1.5% citric acid solution at five pH gradients of 4.5, 4.8, 5.0, 5.2, and 5.5 for 2 - 3 hours, with each gradient soaking for about 30 minutes. Further remove chlorophyll and eliminate bitter taste.

[0048] Enzymolysis: Treat Eucommia ulmoides leaves with 0.2% cellulase and 0.1% pectinase at 40°C for 4 hours to decompose fibers and pectin and release active ingredients.

[0049] Cultivation temperature gradient:

[0050] In the first 3 days, 45°C; in the middle stage, 60°C; in the after - ripening stage, 40°C.

[0051] Indexes of the mature koji: Saccharifying power, 400U / g; esterifying power, 2.5mg / g.

[0052] Treatment of sorghum:

[0053] Crushing: Keep the whole - grain rate ≥80% and the broken - powder rate ≤10%.

[0054] Moistening the grains: Moisten the grains with 90°C hot water, with the water - to - grain ratio of 0.45:1, and stack for 8 hours to prepare for steaming.

[0055] Mix the treated Eucommia ulmoides leaf fragments with the grain - culture mash and adjust the moisture to 55 - 60%.

[0056] Steaming

[0057] Nine - time steaming: Cumulatively add 5% of Eucommia ulmoides leaves in the first two times, 18% of Eucommia ulmoides in the third to sixth times; and 5% of Eucommia ulmoides leaves in the last three times, gradually introducing the active ingredients of Eucommia ulmoides leaves.

[0058] Saccharification

[0059] Inoculating koji: Use daqu, with the dosage being 10 - 15% of the raw materials. Evenly sprinkle the koji powder on the cooled grain - culture mash and mix by turning.

[0060] Control of saccharification conditions: Control the temperature at 25 - 32°C; adjust the moisture to 55 - 60%; stack for saccharification for 24 - 48 hours. When white mycelia appear on the surface of the grain - culture mash and a sweet smell is emitted, it is completed.

[0061] Fermentation

[0062] The first 4 rounds: Each round lasts for 30 days, and the pit temperature is 35 - 40°C.

[0063] The last 4 rounds: Each round lasts for 45 days, and the pit temperature is 28 - 32°C.

[0064] Distillation

[0065] The fermented mash is loosely loaded into the distillation drum. The steam temperature is controlled at 80-95℃.

[0066] Seven times of wine:

[0067] Round 1-2: alcohol concentration 54-60% vol, take 20% of the total base wine, 8% in the first round and 12% in the second round;

[0068] Round 3-5: alcohol concentration 50-53% vol, take 60% of the total base wine, each round accounts for 20%;

[0069] Round 6-7: Alcohol concentration 45-50% yol, take 20% of the total base wine, 15% in the sixth round and 5% in the seventh round.

[0070] Flavor Integration

[0071] Micro-oxygen aging: Control the dissolved oxygen content to 0.5-1.2mg / L to make the wine more mature.

[0072] Blending technology: Select the base wine from the 3rd to 5th rounds (accounting for 60%) as the skeleton of the wine, and carry out the final blending to obtain the Eucommia base wine.

[0073] Key control parameters

[0074] Acidity Control:

[0075] The acidity when entering the cellar is 1.8-2.3; the acidity when leaving the cellar is ≤3.5.

[0076] Starch metabolism:

[0077] Initial starch is 22-24%; residual starch is ≤10%.

[0078] Flavor substances:

[0079] Total esters ≥ 2.5g / L; Eucommia glycoside retention 0.05-0.1g / L; Cyclic terpenes ≥ 15mg / L.

[0080] Quality Assurance Measures

[0081] Control of hazardous substances: methanol ≤ 0.4g / L; cyanide (as HCN) ≤ 8mg / L.

[0082] Stability treatment: -5℃ freezing treatment for 72 hours to inhibit harmful microorganisms, with a filtration accuracy of 0.45μm.

[0083] Production cycle

[0084] Basic brewing cycle: 12 months (including 8 fermentations).

[0085] Aging period: Stored in ceramic jars for ≥3 years (temperature controlled at 15 - 20°C, humidity 75 - 85%), to ensure the flavor and quality stability of the liquor body.

[0086] Final product processing period: 2 months (including freezing filtration and stable blending), to make the liquor body reach the best taste.

[0087] (2) Two-way fermentation to produce flavored liquor

[0088] Prepare raw materials

[0089] Base liquor for liquor: The base liquor for liquor brewed from Eucommia ulmoides leaves.

[0090] Sugar source: Maltose.

[0091] Lactic acid bacteria: Select three strains of Lactobacillus plantarum, Lactobacillus acidophilus, and Lactococcus lactis.

[0092] Two-way fermentation

[0093] Initial fermentation: First, carry out primary fermentation in a two-way fermentation tank. Add Saccharomyces cerevisiae to the base liquor. The concentration of the Saccharomyces cerevisiae cell suspension is 10 7 viable cells / ml. The yeast converts maltose into alcohol and starts to generate preliminary flavor substances. The temperature is usually maintained at 25 - 30°C.

[0094] Secondary fermentation: When the alcohol content reaches 9.5% (v / v), add the pre-cultured lactic acid bacteria (Lactobacillus plantarum, Lactobacillus acidophilus, and Lactococcus lactis in a mass ratio of 1:1:1) to the fermentation broth to initiate secondary fermentation. The concentration of the lactic acid bacteria is 10 5 - 10 7 viable cells / ml. The lactic acid bacteria will continue to ferment a part of the sugars at this stage to produce organic acids such as lactic acid and acetic acid. Fermentation is carried out at 18 - 25°C for 72 hours.

[0095] Cold stabilization: After fermentation is completed, cool the liquid to stop microbial activities and prevent secondary fermentation.

[0096] Control fermentation parameters

[0097] Temperature: The fermentation temperature of yeast is generally between 25 - 30°C, while lactic acid bacteria are sensitive to temperature. The usually suitable temperature range is 30 - 35°C. The temperature at different stages can be adjusted through a dual temperature control system (such as heat and cold exchange) to ensure that the microorganisms ferment under the most suitable conditions.

[0098] pH value adjustment

[0099] The acid production of lactic acid bacteria helps to reduce the pH value and form a taste with balanced acidity. Therefore, the fermentation environment of lactic acid bacteria can be optimized by regularly monitoring the pH and adjusting it appropriately. The pH value set in this example is 6.8.

[0100] Gas control

[0101] During the yeast fermentation stage, oxygen is introduced to promote its aerobic respiration. During the lactic acid bacteria fermentation stage, oxygen introduction is stopped to maintain an anaerobic environment.

[0102] Fermenter model: 50L - 200L two - stage fermenter (Nanjing Tianhui Biotechnology Equipment Co., Ltd.) (3) Preparation of Eucommia ulmoides extract

[0103] The flavor substances in Eucommia ulmoides leaves are mainly volatile terpenoids, aldehydes, and esters.

[0104] Raw material pretreatment

[0105] Collect fresh Eucommia ulmoides leaves, remove impurities, rinse with water, and dry at 50°C with hot air until the moisture content ≤ 8%; crush and pass through an 80 - mesh sieve to obtain a uniform powder; add a composite enzyme (cellulase: pectinase = 1:1) at a mass ratio of 1:100, enzymolyze at 40°C for 2 hours, inactivate the enzyme, and then centrifuge to take the supernatant.

[0106] Primary extraction

[0107] Use a supercritical CO2 extractor (SFT - NPX - 1) for extraction, and the parameters are as follows:

[0108] Supercritical CO2 extraction parameters: pressure is 25 - 30 MPa, temperature is 40 - 45°C;

[0109] CO2 flow rate: 20 - 25 L / h, extraction time 2 - 3 hours;

[0110] Separation kettle pressure: 5 - 6 MPa, temperature is 30°C;

[0111] Low - temperature ethanol extraction: ethanol concentration is 70%, solid - liquid ratio is 1:15, ultrasonic - assisted extraction at 40°C for 1 hour.

[0112] Molecular distillation purification

[0113] Use a molecular distillation equipment (KD / SPD15 - 20 - 30 - 50) for extraction, and the parameters are as follows:

[0114] First - stage distillation (removing heavy impurities):

[0115] Evaporation temperature is 60 - 70°C, system pressure is 10 - 50 Pa;

[0116] The scraping film rotation speed is 200 - 250 rpm, and the feeding rate is 1.0 - 1.5 mL / min.

[0117] Secondary distillation (enriching flavor substances):

[0118] The evaporation temperature is 80 - 90 °C, and the system pressure is 1 - 5 Pa;

[0119] The condensation temperature is -10 °C, and the collection rate of light components > 85%.

[0120] Post-treatment

[0121] Low-temperature concentration: Rotary evaporation (40 °C, -0.09 MPa) until the content of the essence liquid ≥ 95%; Evaporate terpenoids and a small amount of aromatic substances, and retain substances such as eucommia ulmoides polysaccharide and chlorogenic acid.

[0122] Antioxidant treatment: Add nitrogen and seal for preservation.

[0123] (4) Modulating eucommia ulmoides essence liquid and flavored liquor

[0124] Mix the flavored liquor and eucommia ulmoides essence liquid in a ratio of 3:1, and the mixing temperature is 18 °C. At this temperature, it can ensure the full fusion of the essence liquid and the liquor, enhance the eucommia ulmoides flavor, and reduce the spicy taste. After mixing, seal it in a pottery jar.

[0125] The eucommia ulmoides liquor prepared in the above example is required to be tasted and detected as follows:

[0126] Through gas chromatography (GC-MS) technology, a comparative analysis of various compounds is carried out on the commonly brewed eucommia ulmoides liquor and the eucommia ulmoides liquor of the present invention. Various compounds are measured. The lactic acid bacteria fermentation causes a slight increase in the concentration of n-butanol, the overall alcohol components remain stable, but the smoothness of the liquor body is enhanced; the increase in ethyl acetate makes the aroma of the liquor body more complex, and the eucommia ulmoides flavor type is more obvious; the content of aldehyde substances decreases after lactic acid bacteria fermentation, the liquor body is more mellow, and the increase in lactic acid improves the balance of the liquor body, making the taste more round and delicate; the change of ketone substances is small, and it has little impact on the flavor of the liquor body; the content of phenolic substances is slightly lower, and lactic acid bacteria fermentation may reduce these heavier aroma components; lactic acid bacteria fermentation brings more fruity and lactic acid aromas, improving the flavor complexity of the liquor body.

[0127] Table 1: Comparative analysis of different compounds

[0128]

[0129] By setting three repetitions, the traditional steam distillation technology was compared with the molecular distillation technology used in the present invention, and three repetitions were set. The results showed that compared with the traditional steam distillation technology, the molecular distillation technology significantly improved the yield of the essence and effectively retained the active ingredients of Eucommia ulmoides. This technology uses ethanol as the substrate, avoiding a large loss of chlorogenic acid, greatly increasing the retention rate of pinoresinol diglucoside, and thus significantly improving the nutritional value of this Eucommia ulmoides wine.

[0130] Table 2: Comparison results of flavor substance extraction methods

[0131]

[0132] The above-described embodiments are only the preferred embodiments of the present invention, which are only used to explain the present invention and do not limit the scope of implementation of the present invention. For those skilled in the art of this technology, other implementation methods can be made by means of substitution or change according to the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be regarded as being within the scope protected by this application of the present invention.

Claims

1. A method for brewing Eucommia ulmoides liquor, characterized in that: The method comprises the following steps: (1) Treatment of Eucommia ulmoides leaves: The harvested Eucommia ulmoides leaves are subjected to decolorization and enzymatic hydrolysis treatment; (2) Preparation of base wine: Mix 25-35% of Eucommia ulmoides leaves, 50-60% of sorghum, and 10-15% of wheat by mass, soak them in warm water at 45-55° C. for 1 hour, and prepare transparent base wine by steaming, saccharifying, fermenting, and distilling; (3) Bidirectional fermentation: The base wine obtained in step (2) is added with brewer's yeast, wherein the concentration of the brewer's yeast cell suspension is 10 7 live bacteria / ml; primary fermentation was carried out in a fermentation tank at a fermentation temperature of 25-30°C; when the alcohol content reached 9.5%, lactic acid bacteria were added at a concentration of 10 5 ~10 7 viable bacteria / ml, start secondary fermentation, and ferment for 72 hours at 18-25℃; (4) Compound flavoring: extracting Eucommia ulmoides essence at 80-90°C using a molecular distillation device, and finally mixing flavored liquor and Eucommia ulmoides essence in a volume ratio of 3:1 to obtain Eucommia ulmoides liquor.

2. The method for brewing Eucommia ulmoides liquor according to claim 1, characterized in that: The method for harvesting the Eucommia ulmoides leaves in step (1) is as follows: selecting young leaves from May to July, performing a withering treatment on the leaves, and then drying the leaves at 65°C.

3. The method for brewing Eucommia ulmoides liquor according to claim 1, characterized in that: The decolorization method of the Eucommia leaves in step (1) is: soaking in 30% salt water for 12 hours to remove chlorophyll and impurities; and then soaking in a 1.5% citric acid solution with a pH of 4.5-5.5 for 2-3 hours.

4. The method for brewing Eucommia ulmoides liquor according to claim 1, characterized in that: The enzymatic hydrolysis method of the eucommia leaves in step (1) is: treating the eucommia leaves with 0.2% cellulase and 0.1% pectinase at 40° C. for 4 hours.

5. The method for brewing Eucommia ulmoides liquor according to claim 3, characterized in that: The soaking in a 1.5% citric acid solution with a pH of 4.5-5.5 for 2-3 hours is specifically: soaking in 5 gradients of pH 4.5, 4.8, 5.0, 5.2 and 5.5, respectively, and each gradient is soaked for 30 minutes.

6. The method for brewing Eucommia ulmoides liquor according to claim 1, characterized in that: The lactic acid bacteria in step (3) are Lactobacillus plantarum, Lactobacillus acidophilus and Lactococcus mixed in a weight ratio of 1:1:

1.

7. The method for brewing Eucommia ulmoides liquor according to claim 1, characterized in that: In step (3), the pH value in the fermentation tank is controlled to be 6.

8.

8. The method for brewing Eucommia ulmoides liquor according to claim 1, characterized in that: In step (4), the specific steps of extracting Eucommia ulmoides essence are: (1) Raw material pretreatment: fresh Eucommia leaves were collected, washed with clean water after removing impurities, dried with hot air at 50°C until the moisture content was ≤8%; crushed and passed through an 80-mesh sieve to obtain uniform powder; added with complex enzyme at a mass ratio of 1:100, hydrolyzed at 40°C for 2 hours, inactivated the enzyme, and centrifuged to obtain the supernatant; (2) Primary extraction: The extraction was performed using a supercritical CO2 extractor with the following parameters: Supercritical CO2 extraction parameters: pressure 25-30MPa, temperature 40-45℃; CO2 flow rate: 20-25L / h, extraction time 2-3 hours; Separation kettle pressure: 5-6MPa, temperature: 30℃; Low-temperature ethanol extraction: ethanol concentration was 70%, solid-liquid ratio was 1:15, and ultrasonic-assisted extraction was performed at 40°C for 1 hour. (3) Molecular distillation purification The extraction was performed using molecular distillation equipment with the following parameters: Primary distillation is used to remove heavy impurities. The evaporation temperature is set at 60-70°C and the system pressure is 10-50Pa. The scraping speed is 200-250rpm and the feed rate is 1.0-1.5mL / min. Secondary distillation is used to enrich aroma substances, with the evaporation temperature set at 80-90°C and the system pressure set at 1-5Pa; the condensation temperature is -10°C, and the light component collection rate is >85%; Low temperature concentration: Rotary evaporation, set the evaporation temperature to 95°C and the system pressure to -0.09MPa.

9. The method for brewing Eucommia ulmoides liquor according to claim 8, characterized in that: The complex enzyme is a mixture of cellulase and pectinase in a mass ratio of 1:1.

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