Tea wine and preparation method thereof

Abstract

The invention belongs to the technical field of tea wine preparation, and particularly relates to tea wine and a preparation method thereof. S200, performing fermentation; s300, carrying out distillation; s400, vinasse separation and treatment; the invention provides the tea wine based on a route of tea leaf extraction, tea residue fermentation, wine liquid distillation and re-seasoning and the preparation method of the tea wine, and finally the tea wine with good nutritional functionality, taste and quality stability is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of tea wine preparation, and in particular relates to tea wine and a preparation method thereof. Background Art

[0002] Tea wine is a general term for various drinking alcoholic beverages made from tea leaves through fermentation or blending. Based on the brewing method, it can be categorized into fermented, distilled, blended, and sparkling wine types. Fermented and distilled tea wines use tea leaves as the primary ingredient, artificially adding yeast, sugars, and other substances under certain fermentation conditions. Blended tea wine simulates the characteristics of fruit wine, using tea leaves as the primary ingredient, supplemented with edible alcohol, sucrose, and organic acids, blended in a specific proportion and sequence. Sparkling tea wine imitates the flavor and characteristics of champagne, using tea leaves as the primary ingredient and artificially inflated with carbon dioxide.

[0003] Generally speaking, the preparation process of fermented tea wine can be summarized as: tea leaves → extraction → filtration → tea juice → adding auxiliary materials and sugars → inoculation of yeast or koji → fermentation → aging → filtration → clarification → blending → sterilization → finished product.

[0004] The preparation process of distilled tea wine can be summarized as: tea leaves → extraction → filtration → tea juice → adding auxiliary materials and sugars → inoculation of yeast or koji → fermentation → distillation → aging → finished product.

[0005] Compared to the other two, fermented tea wine has the advantages of rich natural flavor, strong layering, a soft and natural taste, and easily absorbed nutrients. However, fermented tea wine has poor quality stability and is prone to problems such as darkening of product color, disharmony of taste, weakening of aroma, and loss of brightness. Currently, color preservation, aroma preservation, and precipitation prevention have become the three major issues plaguing the quality of fermented tea wine, seriously affecting the shelf life and quality stability of the product. Although distilled tea wine has the advantages of high alcohol content, colorless and transparent, and no turbidity, the distillation process cannot evaporate the functional ingredients such as tea polyphenols, caffeine, and tea pigments in the fermentation broth. Therefore, distilled tea wine has lower nutritional and functional properties.

[0006] In order to obtain tea wine that combines the advantages of fermented tea wine and distilled tea wine, the present invention provides a tea wine and a preparation method thereof based on the route of "tea leaf extraction → tea residue fermentation → wine distillation → re-flavoring", so as to obtain a tea wine with good nutritional functionality, taste and quality stability. Summary of the Invention

[0007] The purpose of the present invention is to provide a tea wine and a preparation method thereof in order to obtain a tea wine with good nutritional functionality, taste and quality stability.

[0008] In view of this, the present invention provides a method for preparing tea wine, comprising the steps of: S100, extraction: pre-treating and enzymatically hydrolyzing the tea leaves, then extracting the enzymatically hydrolyzed tea leaves with a biphasic extract containing an aqueous phase and an oil phase, and filtering after extraction to obtain a tea extract and filter residue; S200, fermentation: soaking, steaming, and cooling glutinous rice, and then mixing it with the filter residue obtained in step S100, coarse bamboo fiber, wine koji, and yellow koji, and then adding water and placing it in a vat for primary fermentation for 5 to 7 days; then transferring the brewed product after the primary fermentation to a jar for secondary fermentation for 2 to 6 months; after the secondary fermentation, pressing and filtering to obtain wine lees and wine; S300, distillation: the fermented liquor is poured into a distiller for slow distillation. During the distillation process, the temperature of the liquor is controlled at 85-95°C. The distilled material is condensed in a condenser and collected. The collected condensate is the base liquor of the tea wine. S400, separation and treatment of lees: separating tea residue from lees, grinding the tea residue, and preparing tea residue cellulose for later use; S500, blending: adding the tea residue cellulose obtained in step S400 to the tea extract obtained in step S100, stirring and mixing evenly, and then slowly adding the base wine obtained in step S300. After the base wine is added, the mixture is homogenized and sterilized under high pressure, and then sealed and canned to obtain a tea wine product.

[0009] Furthermore, the step S100 includes: S101, tea pretreatment: picking fresh tea leaves, and withering, killing and crushing the fresh tea leaves to obtain pretreated tea leaves; S102, enzymatic hydrolysis: adding 10-20 times by weight of deionized water to the pretreated tea leaves to prepare a tea suspension, then adding 0.3%-1% of a complex enzyme by weight of the tea leaves, stirring and enzymatically hydrolyzing at 38-50° C. for 0.5-1.5 hours, then heating to 85-95° C. and performing enzyme inactivation treatment for 5-10 minutes to obtain an enzymatically hydrolyzed tea suspension; S103, preparing an extract: taking an oil phase and an aqueous phase in a volume ratio of (2-5):100, and then adding an emulsifier to prepare a two-phase extract; S104, extraction: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with the biphasic extract prepared in step S103, and stirred and extracted for 10-20 minutes at an initial temperature of 40-50°C and a pressure of 20-40 kPa. The pressure is then reduced to 8-12 kPa while maintaining the temperature at 1-3°C above the boiling point corresponding to the current pressure. The tea is stirred and extracted for 5-10 minutes under this condition to complete the first cycle of extraction. The pressure and temperature are then adjusted back to the initial conditions and the extraction is repeated for 2-3 cycles to complete the extraction of the tea leaves. S105, filtration: filtering the mixed system after extraction in step S104 to obtain tea extract and filter residue.

[0010] Furthermore, in step S101, the tea leaf fixing process is as follows: The withered tea leaves are evenly spread on the conveyor belt, and high-temperature steam with a temperature of 90~100℃ is used to quickly act on the surface of the fresh leaves for 80~100s. After that, they are quickly sent to the cooling and conveying section, cooled and spread, and then enter the crushing process.

[0011] Furthermore, the oil phase substance is fruit oil and / or plant seed oil.

[0012] Furthermore, in step S105, the process of filtering the mixed system after extraction includes: first, centrifuging the mixed system after extraction using a centrifuge, the centrifuge speed is 5000-8000 r / min, the centrifugation time is 5-15 minutes, and after centrifugation, a centrifuge liquid and a filter residue are obtained; The centrifuged liquid is further filtered using a 5-10 μm filter element to preliminarily remove large particles in the centrifuged liquid; Then, the tea extract is filtered using a microfiltration membrane with a pore size of 0.1-1.0 μm at an operating pressure of 0.1-0.3 MPa to obtain the tea extract.

[0013] Furthermore, in step S200, the amount of tea residue added is 3-8% of the weight of glutinous rice, the amount of crude bamboo fiber added is 60-120% of the weight of the tea residue, the diameter of the crude bamboo fiber is 100-500 μm, and the fiber length is 0.5-5 cm. The crude bamboo fiber needs to be placed in boiling water and steamed at high temperature for 5-10 minutes before use.

[0014] Furthermore, in step S400, the process of separating the tea residue from the distilled lees is as follows: First, the lees are dried mechanically or naturally to a moisture content of less than 10%. Then, wind-powered grading equipment is used to blow out the tea debris in the lees and collect and obtain the fermented tea residue.

[0015] Furthermore, in step S400, the preparation process of tea residue cellulose is as follows: The ground tea residue is mixed with 20-40 parts by weight of a buffer solution with a pH of 4.6-5.5, and an appropriate amount of cellulose complex enzyme is added, wherein the amount of the cellulose complex enzyme added is 50-100 ECU / g based on the dry weight of the tea residue. The mixed solution is then heated to 40-50° C. and reacted for 3-5 hours under stirring. The mixed solution is then heated to 80-90° C. and kept warm for 15-30 minutes under stirring. After the insulation is completed, the mixed solution is filtered and washed with water until neutral. The enzymatically hydrolyzed tea residue is prepared into an aqueous suspension with a concentration of 5-10wt%, and the mixture is ground at a rotation speed of 1000-1500 rpm for 10-30 minutes to obtain an aqueous suspension of tea residue cellulose.

[0016] Furthermore, in step S500, the weight ratio of the added tea residue cellulose, tea extract, and base wine is (0.05-0.15): (10-30): (80-150); In addition, a trace amount of soluble alkali metal salt or hydroxide is added, and the ratio of the amount of the soluble alkali metal salt or hydroxide added to the weight of the tea residue cellulose is: (0.2-0.6):1; The specific process of blending tea wine is as follows: First, the tea residue cellulose obtained in step S400 is added to the tea extract obtained in step S100. After a high-pressure homogenization treatment for 10 to 20 minutes, the base wine obtained in step S300 is slowly added. After the base wine is added, it is subjected to another high-pressure homogenization and sterilization treatment, and then sealed and canned to obtain a tea wine product.

[0017] In addition, the present invention also provides tea wine prepared by the above-mentioned tea wine preparation method.

[0018] Compared with the traditional tea wine preparation method, the beneficial effects of the present invention are: First, the use of a dual-phase extraction solution of water phase + oil phase is conducive to the co-dissolution of polar and non-polar tea components, which can retain more volatile aroma components, increase the extraction rate of tea functional components, and enhance the aroma level and health value of tea wine; Second, a composite system of "glutinous rice + tea residue + coarse bamboo fiber" is introduced into the fermentation raw materials. This fermentation system not only improves the aroma and taste of the base wine through the tea residue, thereby improving resource utilization, but also uses coarse bamboo fiber to form structural support, thereby improving fermentation efficiency. Third, drawing on the traditional Yongjia "Laojiuhan" preparation process, the "two-stage fermentation + distillation purification" process was introduced. The two-stage fermentation gave the wine a mellow aroma and taste, and the distillation temperature control removed some undesirable fermentation by-products, such as aldehydes and short-chain fatty acids, while retaining some tea aroma and mellow components. The final result was a tea wine base with pure flavor and harmonious body. This not only avoided the problems of traditional tea wine with strong odor and off-flavor, but also gave the base wine good quality stability. Fourth, when blending tea wine, tea residue is used to prepare tea residue cellulose, and the tea residue cellulose is added to tea extract to form a Pickering system, and then the distilled base wine is slowly added. Finally, high-pressure homogenization is performed to improve the dispersion and stability of the system. In this way, not only the high-value utilization of waste is achieved, but also the aroma retention, anti-precipitation and color retention of tea wine can be enhanced, the shelf life can be extended, and the stability and sensory uniformity of tea wine can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the preparation process of the tea wine of the present invention; Figure 2 is a total ion chromatogram of aroma components in the tea extract prepared in Example 1 of the present invention; Figure 3 is a total ion chromatogram of aroma components in the tea extract prepared in Comparative Example 1 of the present invention; Figure 4 It is the total ion chromatogram of the aroma components in the tea extract prepared in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0021] In the description of this application, it should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. For ease of description, the techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and devices should be considered part of the authorization specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values.

[0022] It should be noted that, in the present application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0023] A method for preparing tea wine comprises the following steps: S100, extraction: pre-treating and enzymatically hydrolyzing the tea leaves, then extracting the enzymatically hydrolyzed tea leaves with a biphasic extract containing an aqueous phase and an oil phase, and filtering after extraction to obtain a tea extract and filter residue; S200, fermentation: soaking, steaming, and cooling glutinous rice, and then mixing it with the filter residue obtained in step S100, coarse bamboo fiber, wine koji, and yellow koji, and then adding water and placing it in a vat for primary fermentation for 5 to 7 days; then transferring the brewed product after the primary fermentation to a jar for secondary fermentation for 2 to 6 months; after the secondary fermentation, pressing and filtering to obtain wine lees and wine; S300, distillation: the fermented liquor is poured into a distiller for slow distillation. During the distillation process, the temperature of the liquor is controlled at 85-95°C. The distilled material is condensed in a condenser and collected. The collected condensate is the base liquor of the tea wine. S400, separation and treatment of lees: separating tea residue from lees, grinding the tea residue, and preparing tea residue cellulose for later use; S500, blending: adding the tea residue cellulose obtained in step S400 to the tea extract obtained in step S100, stirring and mixing evenly, and then slowly adding the base wine obtained in step S300. After the base wine is added, the mixture is homogenized and sterilized under high pressure, and then sealed and canned to obtain a tea wine product.

[0024] Compared with the traditional tea wine preparation method, the present invention has made the following improvements: First, the use of a dual-phase extraction solution of water phase + oil phase is conducive to the co-dissolution of polar and non-polar tea components, which can retain more volatile aroma components, increase the extraction rate of tea functional components, and enhance the aroma level and health value of tea wine; Second, a composite system of "glutinous rice + tea residue + coarse bamboo fiber" is introduced into the fermentation raw materials. This fermentation system not only improves the aroma and taste of the base wine through the tea residue, thereby improving resource utilization, but also uses coarse bamboo fiber to form structural support, thereby improving fermentation efficiency. Third, drawing on the traditional Yongjia "Laojiuhan" preparation process, the "two-stage fermentation + distillation purification" process was introduced. The two-stage fermentation gave the wine a mellow aroma and taste, and the distillation temperature control removed some undesirable fermentation by-products, such as aldehydes and short-chain fatty acids, while retaining some tea aroma and mellow components. The final result was a tea wine base with pure flavor and harmonious body. This not only avoided the problems of traditional tea wine with strong odor and off-flavor, but also gave the base wine good quality stability. Fourth, when blending tea wine, we draw on the preparation method of milk tea wine, use tea residue to prepare tea residue cellulose, and add the tea residue cellulose to tea extract to form a Pickering system, then slowly add distilled base wine, and finally use high-pressure homogenization to improve the dispersion and stability of the system. In this way, not only the high-value utilization of waste is achieved, but also the aroma retention, anti-precipitation and color retention of tea wine can be enhanced, the shelf life can be extended, and the stability and sensory uniformity of tea wine can be improved.

[0025] Specifically, step S100 includes: S101, tea pretreatment: picking fresh tea leaves, and withering, killing and crushing the fresh tea leaves to obtain pretreated tea leaves; S102, enzymatic hydrolysis: adding 10-20 times by weight of deionized water to the pretreated tea leaves to prepare a tea suspension, then adding 0.3%-1% of a complex enzyme by weight of the tea leaves, stirring and enzymatically hydrolyzing at 38-50° C. for 0.5-1.5 hours, then heating to 85-95° C. and performing enzyme inactivation treatment for 5-10 minutes to obtain an enzymatically hydrolyzed tea suspension; S103, preparing an extract: taking an oil phase and an aqueous phase in a volume ratio of (2-5):100, and then adding an emulsifier to prepare a two-phase extract; S104, extraction: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with the biphasic extract prepared in step S103, wherein the volume ratio of the tea suspension to the biphasic extract is 1:2-3; and the mixture is stirred and extracted for 10-20 minutes at an initial temperature of 40-50°C and a pressure of 20-40 kPa, and then the pressure is reduced to 8-12 kPa while maintaining the temperature at 1-3°C above the boiling point corresponding to the current pressure. The mixture is stirred and extracted for 5-10 minutes under this condition to complete the first cycle of extraction. The pressure and temperature are then adjusted back to the initial conditions and the extraction is repeated for 2-3 cycles to complete the extraction of the tea leaves; S105, filtration: filtering the mixed system after extraction in step S104 to obtain tea extract and filter residue.

[0026] As a preferred example of the present invention, when picking fresh tea leaves, they are picked according to the standard of "one bud and two leaves".

[0027] As some examples of the present invention, the withering treatment method of fresh tea leaves is: the fresh tea leaves are evenly spread on a bamboo mat or a withering rack, and placed in the sun or a cool and ventilated place to naturally lose water for 5 to 10 hours to obtain the withered tea leaves.

[0028] As a preferred example of the present invention, steam-curing is a tea-tea-curing method. The specific process involves spreading the withered tea leaves evenly on a conveyor belt. High-temperature steam at 90-100°C is then applied rapidly to the surface of the fresh leaves for 80-100 seconds. The leaves are then quickly conveyed to a cooling and conveying section, where they are cooled and spread out before entering the crushing process. This prevents steam accumulation and yellowing of the leaves caused by continued steaming.

[0029] Compared with traditional drum-type fixing and wok-type fixing, the steam fixing method selected by the present invention draws on the Japanese sencha process, placing the tea leaves in high-temperature steam for 80-100s of deep steaming. During the fixing process, the high-temperature steam can be used to quickly kill the enzyme. At the same time, due to the long steaming time of this deep steaming method, the tea fiber after steaming becomes fragile, and the active ingredients are more soluble, so that the tea extract obtained by extraction is green, which can effectively retain the green color of the tea leaves and has strong color retention, so that the tea extract and tea wine products obtained subsequently are green in color, which is more in line with user psychological expectations. At the same time, steam fixing can make full use of the characteristics of uniform steam temperature and fast penetration, quickly passivate polyphenol oxidase activity, inhibit the oxidation of tea polyphenols, and better retain water-soluble umami components such as amino acids and sugars, so that the tea wine finally obtained tastes fresh and mellow, has a richer taste, a high content of functional ingredients, and has good nutritional functionality and taste. In addition, this steam fixing method is contactless throughout the process, clean and hygienic, and is more suitable for modern food-grade standards and industrialized batch production.

[0030] As some examples of the present invention, the tea crushing process is: using a knife crusher, hammer crusher, roller crusher, impact crusher, air flow crusher, vibration mill and other equipment to crush the tea leaves to a particle size of ≤1mm through single crushing or multiple crushing processes.

[0031] Preferably, the particle size of the tea leaves after crushing is 0.1-0.5 mm.

[0032] As some examples of the present invention, in step S102, the complex enzyme is a complex enzyme composed of cellulase, pectinase and protease. Preferably, the weight ratio of the cellulase, pectinase and protease is 2:1:1.

[0033] Preferably, in step S102, before enzymatic hydrolysis, an appropriate amount of acid or alkali solution may be added to adjust the pH of the tea suspension to 5.0-6.5.

[0034] As some examples of the present invention, in step S103, the oil phase substance is fruit oil and / or plant seed oil, the fruit oil can be one or more of lemon oil, orange peel oil, grapefruit oil, lime oil, bergamot oil, citrus oil, coconut oil, etc., the plant seed oil can be one or more of camellia seed oil, grape seed oil, olive oil, etc. At this time, the prepared tea wine is a slightly emulsified tea wine with fruity aroma or herbal aroma.

[0035] Preferably, the oil phase substance is a mixed oil formed by orange peel oil + grape seed oil, or a mixed oil formed by bergamot oil + camellia oil, or a mixed oil formed by coconut oil + bergamot oil. In comparison, the tea wine aroma prepared by adding these oil phase substances is more popular with consumers.

[0036] In the present invention, by adding a small amount of oil phase components to the extract, on the one hand, the aroma and taste of the prepared tea wine can be improved; on the other hand, the volatile oil, fat-soluble aromatic substances and other effective ingredients in the tea leaves can be extracted through the oil phase substances in the extract, thereby retaining and strengthening the natural aroma of the tea leaves in the extract and improving the aroma quality of the prepared tea wine.

[0037] As some examples of the present invention, in step S103, the emulsifier is selected from one or more of Tween 80, fatty acid glycerides, stearic acid glyceride, sodium stearoyl lactylate (SSL), sucrose fatty acid ester (SE), sorbitol fatty acid ester, etc., and the amount of the emulsifier added to the two-phase extract is 0.5~2wt%.

[0038] In addition, in step S104, the reduced pressure and heating alternating extraction process, based on the enzymatic hydrolysis and biphasic extraction solution, can further effectively promote the full release of the total active ingredients of the tea leaves through the mutual coordination and process control of temperature, pressure and stirring. Specifically: First, during the extraction process, the pressure and temperature are cyclically adjusted, causing the extract to boil suddenly and rapidly under reduced pressure and heating conditions, rapidly releasing a large number of bubbles, resulting in explosive vaporization and gas agitation. These rapidly generated bubbles can penetrate or expand within the cell structure, tearing the tea cell structure and interfacial membranes, and promoting the release of the active ingredients within. Secondly, at the same time, the bubbles generated under reduced pressure and heating expand, diffuse and burst rapidly in the extract, which can also disturb and break the contact interface between the solvent in the extract and the plant tissue, promote good contact between the solvent in the extract and the plant tissue, increase the migration rate of the extract from the solid phase to the liquid phase, strengthen the extraction, and promote the extraction of effective ingredients such as tea polyphenols and aromatic substances; Third, low-temperature heating extraction can also prevent excessive high temperature from destroying active substances such as tea polyphenols and vitamins, while reducing pigment degeneration and the precipitation of bitter substances, and improving the taste of tea wine.

[0039] As a preferred example of the present invention, in step S105, the process of filtering the mixed system after extraction includes: First, the mixed system after extraction is centrifuged in a centrifuge at a speed of 5000-8000 r / min and a centrifugation time of 5-15 min to obtain a centrifuge liquid and a filter residue; The centrifuged liquid is then filtered using a 5-10 μm filter element to preliminarily remove large particles from the centrifuged liquid, while preventing subsequent clogging of the microfiltration membrane pores and extending the life of the microfiltration membrane. Then, a microfiltration membrane with a pore size of 0.1~1.0μm is used for filtration at an operating pressure of 0.1~0.3MPa to achieve the purpose of sterilization and impurity removal while retaining the active ingredients. After microfiltration, a tea extract with stable aroma and high content of functional ingredients is obtained.

[0040] In the present invention, by subjecting the extract to a three-stage filtration treatment method of "centrifugation → primary filtration → microfiltration" in sequence, it is possible to remove larger biological macromolecules, pectin, starch and other particles that are likely to cause turbidity and precipitation of the tea soup, as well as microorganisms such as bacteria and Escherichia coli in the tea extract, while retaining the tea polyphenols, caffeine, amino acids and other nutrients in the extract, thereby improving the stability of the tea wine and giving the tea wine a good tea flavor and nutritional source.

[0041] Furthermore, in the step S200, based on the amount of glutinous rice (dry weight), the amount of tea residue (dry weight) added is 3-8% of the weight of the glutinous rice.

[0042] Furthermore, in the step S200, the amount of the crude bamboo fiber (dry weight) added is 60-120% of the weight of the tea residue (dry weight).

[0043] Furthermore, in the step S200, based on the amount of glutinous rice (dry weight), the amount of the wine koji added is 0.5-1.5wt%, the amount of the yellow koji added is 0.3-0.8wt%, and the amount of water added is 90-110wt%.

[0044] Furthermore, in the step S200, the amount of water added is 1:(1-1.5) of the glutinous rice (dry weight).

[0045] Preferably, the diameter of the coarse bamboo fiber is 100-500 μm, and the fiber length is 0.5-5 cm.

[0046] Preferably, the crude bamboo fiber needs to be placed in boiling water and steamed at high temperature for 5 to 10 minutes before use.

[0047] Preferably, in step S200, the filter residue needs to be washed with water and centrifuged 2 to 3 times before use.

[0048] To ensure effective extraction, the tea residue obtained after extraction is relatively finely ground. This disrupts its physical structure, impairs aeration, and easily breeds bacteria, leading to low fermentation efficiency. Furthermore, the finely ground tea residue easily adheres to raw materials such as glutinous rice, forming lumps and agglomerates. This makes the fermentation system sticky and compacted, lacking a porous structure and hindering the escape of fermentation gases. More problematically, this localized accumulation of raw materials can easily lead to localized hypoxia, causing the growth of anaerobic bacteria and restricting the metabolism of aerobic / facultative bacteria, affecting alcohol and aroma production, ultimately leading to odor problems such as "reversion," "rancidity," and "muddy odor."

[0049] To improve this situation, the present invention adds an appropriate amount of coarse bamboo fiber during the first fermentation stage. The fiber's inherent porous and sturdy properties create a skeleton structure within the fermentation paste, microscopically "stretching" the fermentation matrix. This maintains a loose, stable brewing state, improves the fermentation microenvironment, and allows for better oxygen exchange between the fermentation matrix, promoting yeast and bacterial growth while preventing undesirable phenomena such as clumping and agglomeration during fermentation. Furthermore, the active substances in the coarse bamboo fiber react with substances in the lees to produce substances with ester and bamboo aromas, resulting in a clearer aroma and richer taste for the tea wine.

[0050] Furthermore, in step S200, the fermentation is preferably carried out between the winter solstice and the fifth day of the fifth lunar month (before the fifth day of the fifth lunar month), the glutinous rice is preferably Nanxi River late glutinous rice, and the water used for fermentation is preferably mountain spring water.

[0051] Furthermore, in step S200, the fermentation should be stirred and started every day during the first fermentation process.

[0052] As a preferred example of the present invention, in step S200, after the secondary fermentation, the brewed product after the secondary fermentation can be transferred to a supercritical carbon dioxide environment and aged in a supercritical carbon dioxide environment at low temperature. The specific process can be referred to the relevant existing technology and will not be described here. The base wine has a better flavor after aging.

[0053] As a preferred example of the present invention, when the brewed product after secondary fermentation is subjected to post-fermentation in a supercritical carbon dioxide environment, the secondary fermentation time can be shortened to 0.5 to 1 month.

[0054] As a preferred example of the present invention, in step S400, the process of separating the tea residue from the distilled lees is as follows: First, the lees are dried mechanically or naturally to a moisture content of less than 10%. Then, wind-powered grading equipment is used to blow out the tea debris in the lees and collect and obtain the fermented tea residue.

[0055] As some examples of the present invention, the process of mechanically drying the lees is as follows: first, a filter press is used to mechanically press to remove most of the moisture in the lees, and then hot air is used to dry the lees until the moisture content is less than 10%.

[0056] Preferably, in step S400, the tea residues can be ground to a particle size of less than 100 μm using a ball mill, a freezer mill, a hammer mill, a nano-grinding device, etc., and then used to prepare tea residue cellulose.

[0057] As a preferred example of the present invention, the preparation process of the tea residue cellulose is as follows: 1-3 parts by weight of ground tea residue are mixed with 20-40 parts by weight of a buffer solution having a pH of 4.6-5.5, and an appropriate amount of cellulose complex enzyme is added, wherein the amount of cellulose complex enzyme added is 50-100 ECU / g based on the dry weight of the tea residue. The mixed solution is then heated to 40-50° C. and reacted for 3-5 hours under stirring. The mixed solution is then heated to 80-90° C. and kept warm for 15-30 minutes under stirring. After the insulation is completed, the mixed solution is filtered and washed with water until neutral. The enzymatically hydrolyzed tea residue is prepared into an aqueous suspension with a concentration of 5-10wt%, and the mixture is ground at a rotation speed of 1000-1500 rpm for 10-30 minutes to obtain an aqueous suspension of tea residue cellulose.

[0058] As some examples of the present invention, the buffer solution is selected from acetic acid-sodium acetate buffer, citric acid-sodium citrate buffer, lactic acid-sodium lactate buffer, etc.

[0059] As some examples of the present invention, filtration during the preparation of tea residue cellulose can be performed using a 10-30 μm filter cloth or filter screen to intercept large particles and fiber blocks. The filtration pressure is generally controlled at 0.1-0.5 MPa and the temperature can be maintained at 40-50° C. to avoid fiber damage.

[0060] As some examples of the present invention, the aqueous suspension of tea slag cellulose can be prepared into powder by vacuum freeze drying or the like, or directly stored at a low temperature below 15°C as an aqueous suspension of tea slag cellulose and directly added to tea extract for use.

[0061] Preferably, in step S500, the weight ratio of the added tea residue cellulose, tea extract, and base wine is (0.05-0.15): (10-30): (80-150).

[0062] In actual production, because the amount of tea residue cellulose used is very small, a large amount of tea residue cellulose can be prepared at one time and then used in batches during the tea wine production process as the production proceeds.

[0063] As a preferred example of the present invention, in step S500, a trace amount of soluble alkali metal salt or hydroxide, such as magnesium chloride, calcium chloride, etc., is also added, and the ratio of the added amount of the soluble alkali metal salt or hydroxide to the dry weight of the tea residue cellulose is: (0.2~0.6):1;.

[0064] As a preferred example of the present invention, in step S500, when a soluble alkali metal salt or hydroxide is added, the specific process of preparing tea wine is as follows: First, the tea residue cellulose obtained in step S400 is added to the tea extract obtained in step S100. After a high-pressure homogenization treatment for 10 to 20 minutes, the base wine obtained in step S300 is slowly added. After the base wine is added, it is subjected to another high-pressure homogenization and sterilization treatment, and then sealed and canned to obtain a tea wine product.

[0065] As some examples of the present invention, in step S500, a high-pressure homogenization process is: placing the mixed liquid in a high-pressure homogenizer and treating it at a pressure of 30-50 MPa for 10-20 minutes.

[0066] As some examples of the present invention, in step S500, the secondary high-pressure homogenization process is: placing the mixed liquid in a high-pressure homogenizer and treating it at a pressure of 10-30 MPa for 10-20 minutes.

[0067] In the tea wine blending process, by adding a small amount of soluble alkali metal salt or hydroxide, the positive charge of the metal cations therein can be used to form a cationic bridge, and the cationic bridge can be used to promote the complexation of tea residue cellulose with the negatively charged components in the tea extract to form CNC-M +-A ternary complex, where A refers to some negatively charged components in tea extract, such as tea polyphenols, amino acids, polysaccharides, soluble protein hydrolysates, etc. Compared with tea slag cellulose, the surface of pure tea slag cellulose particles is mainly composed of hydroxyl groups, and the surface activity is limited. This ternary complex is formed by M + After bridging, the A component has phenolic hydroxyl, carboxyl, amide and other functional groups, which have better affinity with the oil-water interface. Therefore, the tea residue cellulose + After bridging, the surface can adsorb or bond these A components, making the particles more amphiphilic and more easily adsorbed on the oil-water interface, thereby making the formed Pickering emulsion more stable. In addition, since CNC is weakly negatively charged, A is also negatively charged. + The space hindering structure formed under the bridge increases the repulsive force between the emulsifier particles, making it difficult for the formed complex particles to aggregate, settle or aggregate at the interface. At the same time, on the surface of the oil phase, the CNC-M + -A complex can form a dense particle film and construct a particle adsorption shell layer with typical Pickering emulsion characteristics, while preventing the fusion of oil droplets and improving the dispersion uniformity and stability of component A.

[0068] The tea wine and its preparation method provided by the present invention are illustrated below by means of specific examples: Example 1 Preparation of tea extract: S101, tea pretreatment: picking fresh tea leaves, and withering, killing, and crushing the fresh tea leaves to a particle size of 0.5 mm to obtain pretreated tea leaves; S102, enzymatic hydrolysis: adding 15 times the amount of deionized water by weight to the pretreated tea leaves to prepare a tea suspension, then adding 0.5% of the weight of the tea leaves in a complex enzyme, stirring and enzymatically hydrolyzing at 45°C for 1 hour, then heating to 90°C and performing enzyme inactivation treatment for 7 minutes to obtain an enzymatically hydrolyzed tea suspension; S103, preparing an extract: taking an oil phase and an aqueous phase at a volume ratio of 5:100, and then adding an emulsifier to prepare a two-phase extract; wherein the oil phase is a mixed oil formed by mixing orange peel oil and grape seed oil at a volume ratio of 1:1; S104, extraction: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with the biphasic extract prepared in step S103, wherein the volume ratio of the tea suspension to the biphasic extract is 1:2; and after stirring and leaching for 20 minutes at an initial temperature of 45°C and a pressure of 30 kPa, the pressure is reduced to 10 kPa while maintaining the temperature at 2°C above the boiling point corresponding to the current pressure, and stirring and leaching are continued for 10 minutes under this state to complete the first cycle of extraction. Thereafter, the pressure and temperature are adjusted back to the initial state, and the extraction is repeated for two cycles to complete the extraction of the tea leaves; S105, filtration: filtering the mixed system after extraction in step S104 to obtain tea extract and filter residue.

[0069] Example 2 Preparation of base wine: The glutinous rice was soaked, steamed, and cooled, and then mixed with the filter residue obtained after the extraction in Example 1, crude bamboo fiber, wine koji, and yellow clothing koji, and then water was added and placed in a jar for primary fermentation for 7 days; the brewed product after the primary fermentation was then transferred to a jar and subjected to secondary fermentation for 3 months; after the secondary fermentation, the brewed product was pressed and filtered to obtain wine lees and wine; wherein the amount of the tea residue added was 6% of the weight of the glutinous rice, the amount of the crude bamboo fiber added was 100% of the weight of the tea residue, the diameter of the crude bamboo fiber was 300 μm, and the fiber length was 3 cm. The crude bamboo fiber was placed in boiling water and steamed at high temperature for 10 minutes before use; Then the fermented wine is poured into a distiller for slow distillation. During the distillation process, the temperature of the wine is controlled at 90°C. The distilled substance is condensed in a condenser and collected. The collected condensate is the base wine of the tea wine.

[0070] Example 3 Preparation of tea residue cellulose: The tea residue in the fermented lees in Example 2 was separated and ground to a particle size of less than 100 μm. 3 parts by weight of the ground tea residue were mixed with 40 parts by weight of a buffer solution having a pH of 4.6 to 5.5, and an appropriate amount of cellulose complex enzyme was added, wherein the amount of cellulose complex enzyme added was 80 ECU / g based on the dry weight of the tea residue. The mixture was then heated to 45° C. and reacted under stirring for 3 h. The mixture was then heated to 90° C. and kept warm under stirring for 20 min. After the insulation was completed, the mixture was filtered and washed with water until neutral. The enzymatically hydrolyzed tea residue was prepared into an aqueous suspension with a concentration of 10 wt%, and the mixture was ground at a rotation speed of 1500 rpm for 10 min to obtain an aqueous suspension of tea residue cellulose.

[0071] Examples 4 to 7 Preparation of tea wine: The tea slag cellulose obtained in Example 3 was added to the tea extract obtained in Example 1, stirred for 20 minutes to mix evenly, and then the base wine prepared in Example 2 was slowly added. After the base wine was added, the mixture was placed in a high-pressure homogenizer and treated at a pressure of 20 MPa for 10 minutes, and then sterilized and sealed to obtain a tea wine product. Among them, in the process of preparing tea wine, when adding soluble alkali metal salts or hydroxides, the mixed system of tea extract and tea residue cellulose needs to be subjected to a high-pressure homogenization treatment at a pressure of 40 MPa for 20 minutes.

[0072] The raw material components of the tea wine in Examples 4 to 7 are shown in Table 1 below: Table 1 Raw materials of tea wine Comparative Example 1 Preparation of tea extract: The only difference between it and the above-mentioned embodiment 1 is: The extraction process in step S104 is as follows: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with the two-phase extract prepared in step S103, and the tea is extracted after stirring for 60 minutes under the initial state of temperature 45°C and pressure 30 kPa.

[0073] Comparative Example 2 Preparation of tea extract: The only difference between it and the above-mentioned embodiment 1 is: The extraction process in step S104 is as follows: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with deionized water, wherein the volume ratio of the tea suspension to the deionized water is 1:2; then, under the initial state of temperature 45°C and pressure 30 kPa, after stirring and leaching for 20 minutes, the pressure is reduced to 10 kPa, while the temperature is maintained at 2°C above the boiling point corresponding to the current pressure, and stirred and leached for 10 minutes in this state to complete the first cycle of extraction, and then the pressure and temperature are adjusted to the initial state again, and after repeating the extraction for 2 cycles, the tea leaves are extracted.

[0074] Comparative Example 3 Preparation of base wine: The only difference between it and the above-mentioned Example 2 is that: crude bamboo fiber was not added during the fermentation process. During the fermentation process, it was found that compared with Example 2, it was slightly deposited into blocks and agglomerates.

[0075] Test Example 1 Aroma component detection and analysis: The aroma components in the tea extracts obtained from Example 1, Comparative Example 1 and Comparative Example 2 were determined by GC / MS analysis. The total ion chromatograms of the aroma components in the tea extracts obtained are shown in FIG. Figures 2-4 As shown, the preparation process of the test solution is as follows: take 200 mL of tea extract, add 100 mL of organic solvent and extract three times, then combine the organic phases, and rotary evaporate and concentrate the organic phase to 10 mL at 32°C, then add an appropriate amount of anhydrous sodium sulfate and let it stand in a refrigerator at 2°C for 10 hours, then use a nitrogen blow dryer to concentrate the sample to 1.5 mL and then analyze it.

[0076] The mass spectrometry data of each component were analyzed and searched using the database (NIST11). At the same time, relevant literature was referred to further determine the main detected substances. The peak area normalization analysis method was used to determine the relative content of each aroma component. The analysis results are shown in Table 2 below.

[0077] Table 2 Detection and analysis results of main aroma components in tea extract Test Example 2 Sensory evaluation of tea wine: The appearance, aroma and taste of tea wine are evaluated by sensory evaluation. The sensory evaluation standards for tea wine are shown in Table 3. The sensory evaluation of tea wine is conducted by relevant professionals.

[0078] Table 3 Sensory scoring criteria for tea and wine The sensory evaluation results of the tea wines prepared in Examples 4 to 7 are shown in Table 4 below: Table 4 Sensory evaluation results of tea and wine Test Example 3 Tea wine stability test: Stability testing includes freezing treatment, biological treatment, and photo-oxidation stability testing, including: The freezing treatment is to place the tea wine in a freezing condition for 24 hours, then take out the sample and measure its chromaticity and transmittance; The biological treatment was to place the tea wine at 30°C for 72 h and then measure the color and transmittance of the sample; The photooxidative stability test is to place the tea wine under sunlight for 24 hours, and at the same time conduct a control test indoors to measure the chromaticity and transmittance of the sample; The above colorimetry was measured at 430 nm, using water as a blank; The measurement results are shown in Table 5 below: Table 5 Test results of tea wine freezing treatment stability Table 6 Results of tea wine biological treatment stability test Table 7 Results of photooxidative stability test of tea wine The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A method for preparing tea wine, characterized in that: Including steps: S100, extraction: pre-treating and enzymatically hydrolyzing the tea leaves, then extracting the enzymatically hydrolyzed tea leaves with a biphasic extract containing an aqueous phase and an oil phase, and filtering after extraction to obtain a tea extract and filter residue; S200, fermentation: soaking, steaming, and cooling glutinous rice, and then mixing it with the filter residue obtained in step S100, coarse bamboo fiber, wine koji, and yellow koji, and then adding water and placing it in a vat for primary fermentation for 5 to 7 days; then transferring the brewed product after the primary fermentation to a jar for secondary fermentation for 2 to 6 months; after the secondary fermentation, pressing and filtering to obtain wine lees and wine; S300, distillation: the fermented liquor is poured into a distiller for slow distillation. During the distillation process, the temperature of the liquor is controlled at 85-95°C. The distilled material is condensed in a condenser and collected. The collected condensate is the base liquor of the tea wine. S400, separation and treatment of lees: separating tea residue from lees, grinding the tea residue, and preparing tea residue cellulose for later use; S500, blending: adding the tea residue cellulose obtained in step S400 to the tea extract obtained in step S100, stirring and mixing evenly, and then slowly adding the base wine obtained in step S300. After the base wine is added, the mixture is homogenized and sterilized under high pressure, and then sealed and canned to obtain a tea wine product.

2. The method for preparing tea wine according to claim 1, wherein The step S100 includes: S101, tea pretreatment: picking fresh tea leaves, and withering, killing and crushing the fresh tea leaves to obtain pretreated tea leaves; S102, enzymatic hydrolysis: adding 10-20 times by weight of deionized water to the pretreated tea leaves to prepare a tea suspension, then adding 0.3%-1% of a complex enzyme by weight of the tea leaves, stirring and enzymatically hydrolyzing at 38-50° C. for 0.5-1.5 hours, then heating to 85-95° C. and performing enzyme inactivation treatment for 5-10 minutes to obtain an enzymatically hydrolyzed tea suspension; S103, preparing an extract: taking an oil phase and an aqueous phase in a volume ratio of (2-5):100, and then adding an emulsifier to prepare a two-phase extract; S104, extraction: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with the biphasic extract prepared in step S103, and stirred and extracted for 10-20 minutes at an initial temperature of 40-50°C and a pressure of 20-40 kPa. The pressure is then reduced to 8-12 kPa while maintaining the temperature at 1-3°C above the boiling point corresponding to the current pressure. The tea is stirred and extracted for 5-10 minutes under this condition to complete the first cycle of extraction. The pressure and temperature are then adjusted back to the initial conditions and the extraction is repeated for 2-3 cycles to complete the extraction of the tea leaves. S105, filtration: filtering the mixed system after extraction in step S104 to obtain tea extract and filter residue.

3. The method for preparing tea wine according to claim 2, characterized in that: In step S101, the tea leaf fixing process is as follows: The withered tea leaves are evenly spread on the conveyor belt, and high-temperature steam with a temperature of 90~100℃ is used to quickly act on the surface of the fresh leaves for 80~100s. After that, they are quickly sent to the cooling and conveying section, cooled and spread, and then enter the crushing process.

4. The method for preparing tea wine according to claim 2, characterized in that: In step S103, the oil phase substance is fruit oil and / or plant seed oil.

5. The method for preparing tea wine according to claim 2, wherein: In step S105, the process of filtering the mixed system after extraction includes: First, the mixed system after extraction is centrifuged in a centrifuge at a speed of 5000-8000 r / min and a centrifugation time of 5-15 min to obtain a centrifuge liquid and a filter residue; The centrifuged liquid is further filtered using a 5-10 μm filter element to preliminarily remove large particles in the centrifuged liquid; Then, the tea extract is filtered using a microfiltration membrane with a pore size of 0.1-1.0 μm at an operating pressure of 0.1-0.3 MPa to obtain the tea extract.

6. The method for preparing tea wine according to claim 1, characterized in that: In step S200, the amount of tea residue added is 3-8% of the weight of glutinous rice, the amount of crude bamboo fiber added is 60-120% of the weight of the tea residue, the diameter of the crude bamboo fiber is 100-500 μm, and the fiber length is 0.5-5 cm. The crude bamboo fiber needs to be placed in boiling water and steamed at high temperature for 5-10 minutes before use.

7. The method for preparing tea wine according to claim 1, characterized in that: In step S400, the process of separating the tea residue from the distilled lees is as follows: First, the lees are dried mechanically or naturally to a moisture content of less than 10%. Then, wind-powered grading equipment is used to blow out the tea debris in the lees and collect and obtain the fermented tea residue.

8. The method for preparing tea wine according to claim 1, characterized in that: In step S400, the preparation process of tea residue cellulose is as follows: 1-3 parts by weight of ground tea residue are mixed with 20-40 parts by weight of a buffer solution having a pH of 4.6-5.5, and an appropriate amount of cellulose complex enzyme is added, wherein the amount of cellulose complex enzyme added is 50-100 ECU / g based on the dry weight of the tea residue. The mixed solution is then heated to 40-50° C. and reacted for 3-5 hours under stirring. The mixed solution is then heated to 80-90° C. and kept warm for 15-30 minutes under stirring. After the insulation is completed, the mixed solution is filtered and washed with water until neutral. The enzymatically hydrolyzed tea residue is prepared into an aqueous suspension with a concentration of 5-10wt%, and the mixture is ground at a rotation speed of 1000-1500 rpm for 10-30 minutes to obtain an aqueous suspension of tea residue cellulose.

9. The method for preparing tea wine according to claim 1, characterized in that: In step S500, the weight ratio of the added tea residue cellulose, tea extract, and base wine is (0.05-0.15): (10-30): (80-150); In addition, a trace amount of soluble alkali metal salt or hydroxide is added, and the ratio of the amount of the soluble alkali metal salt or hydroxide added to the weight of the tea residue cellulose is: (0.2-0.6):1; The specific process of blending tea wine is as follows: First, the tea residue cellulose obtained in step S400 is added to the tea extract obtained in step S100. After a high-pressure homogenization treatment for 10 to 20 minutes, the base wine obtained in step S300 is slowly added. After the base wine is added, it is subjected to another high-pressure homogenization and sterilization treatment, and then sealed and canned to obtain a tea wine product.

10. Tea wine prepared according to the method for preparing tea wine according to any one of claims 1 to 9.

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