A tea wine and its preparation method

Abstract

This invention belongs to the field of tea wine preparation technology, and particularly relates to a tea wine and its preparation method, including the following steps: S100, extraction; S200, fermentation; S300, distillation; S400, separation and treatment of lees; S500, blending. This invention provides a tea wine and its preparation method based on the route of "tea extraction → tea residue fermentation → wine distillation → re-flavoring", ultimately obtaining a tea wine with good nutritional functionality, taste and quality stability.

Description

Technical Field

[0001] This invention belongs to the field of tea wine preparation technology, and particularly relates to a tea wine and its preparation method. Background Technology

[0002] Tea wine is a general term for various alcoholic beverages made primarily from tea leaves through fermentation or blending. Based on different brewing methods, it can be divided into fermented, distilled, blended, and sparkling wine types. Fermented and distilled tea wines are made primarily from tea leaves, with the addition of yeast, sugars, and other substances under specific fermentation conditions. Blended tea wines are made by mimicking the characteristics of fruit wines, using tea leaves as the main ingredient and supplementing them with edible alcohol, sucrose, organic acids, etc., in a specific proportion and order. Sparkling tea wines imitate the flavor and characteristics of champagne, using tea leaves as the main ingredient and artificially infusing them with carbon dioxide.

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

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

[0005] Compared to fermented tea wines, fermented tea wines have the advantages of rich natural flavor, strong layers of complexity, smooth and natural taste, and easily absorbed nutrients. However, fermented tea wines have poor quality stability and are prone to problems such as darkening of color, unpleasant taste, fading aroma, and loss of brightness. Currently, color preservation, aroma preservation, and sediment prevention have become the three major problems plaguing the quality of fermented tea wines, seriously affecting product shelf life and quality stability. Distilled tea wines, while having advantages such as higher alcohol content, colorless transparency, and no turbidity, cannot extract functional components such as tea polyphenols, caffeine, and tea pigments from the fermented liquid during the distillation process. Therefore, distilled tea wines have lower nutritional and functional properties.

[0006] To obtain a tea wine that combines the advantages of both fermented and distilled tea wines, this invention provides a tea wine and its preparation method based on the route of "tea extraction → tea residue fermentation → liquor 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 this invention is to address the aforementioned technical problems by providing a tea wine and its preparation method, thereby obtaining a tea wine that combines excellent nutritional functionality, taste, and quality stability.

[0008] In view of this, the present invention provides a method for preparing tea wine, comprising the following steps:

[0009] S100, Extraction: Tea leaves are pretreated and enzymatically hydrolyzed, and then the hydrolyzed tea leaves are extracted with a two-phase extract containing an aqueous phase and an oil phase. After extraction, the extract is filtered to obtain tea extract and filter residue.

[0010] S200, Fermentation: Soak glutinous rice, steam it, cool it, and then mix it with the filter residue, coarse bamboo fiber, yeast, and yellow yeast obtained in step S100. Then add water and put it into a vat for the first fermentation for 5-7 days. After that, transfer the fermented product to a jar for the second fermentation for 2-6 months. After the second fermentation, press and filter to obtain the lees and wine.

[0011] S300, Distillation: Take the fermented wine and pour it into a still for slow distillation. During the distillation process, control the temperature of the wine at 85~95℃. The distilled substance is collected after being condensed by a condenser. The collected condensate is the base wine of the tea wine.

[0012] S400, Distillers' grains separation and treatment: Separate tea residue from the distillers' grains, grind the tea residue and prepare tea residue cellulose for later use;

[0013] S500, Blending: Add the tea residue cellulose obtained in step S400 to the tea extract obtained in step S100, stir and mix evenly, then slowly add the base liquor obtained in step S300. After the base liquor is added, the product is subjected to high-pressure homogenization and sterilization, and then sealed and bottled to obtain the tea wine product.

[0014] Furthermore, step S100 includes:

[0015] S101, Tea pretreatment: Fresh tea leaves are picked and subjected to withering, fixation and crushing to obtain pretreated tea leaves;

[0016] S102, Enzymatic hydrolysis: Add 10-20 times the amount of deionized water to the pretreated tea leaves by weight to prepare a tea suspension. Then add 0.3%-1% of the weight of the tea leaves with a compound enzyme. Stir and hydrolyze at 38-50℃ for 0.5-1.5 hours. After that, raise the temperature to 85-95℃ and perform enzyme inactivation treatment for 5-10 minutes to obtain the enzymatically hydrolyzed tea suspension.

[0017] S103, Preparation of extract: Take the oil phase and water phase at a volume ratio of (2~5):100, then add emulsifier to prepare a two-phase extract;

[0018] S104, Extraction: The enzymatically hydrolyzed tea suspension obtained in step S102 is mixed with the biphasic extract obtained in step S103. Under the initial conditions of 40-50℃ and 20-40KPa, the mixture is stirred and extracted for 10-20 minutes. Then, the pressure is reduced to 8-12KPa, while the temperature is maintained 1-3℃ above the boiling point corresponding to the current pressure. The mixture is stirred and extracted for 5-10 minutes under these conditions to complete the first cycle of extraction. After that, the pressure and temperature are adjusted back to the initial conditions, and the extraction is repeated for 2-3 cycles to complete the extraction of the tea.

[0019] S105, Filtration: After filtering the mixture system after extraction in step S104, tea extract and filter residue are obtained.

[0020] Furthermore, in step S101, the tea leaf fixation process is as follows:

[0021] After the tea leaves have withered, they are spread evenly on a conveyor belt and then subjected to high-temperature steam at 90-100℃ for 80-100 seconds. After that, they are quickly sent to the cooling conveyor section, cooled and spread out, and then enter the crushing process.

[0022] Furthermore, the oil phase substance is fruit-flavored oil and / or vegetable seed oil.

[0023] Furthermore, in step S105, the process of filtering the extracted mixture includes: firstly, centrifuging the extracted mixture using a centrifuge at a speed of 5000~8000 r / min for a time of 5~15 min, and obtaining centrifuged liquid and filter residue after centrifugation.

[0024] The centrifuged liquid is further filtered using a 5-10μm filter cartridge to initially remove large particles from the centrifuged liquid;

[0025] Then, the tea extract was obtained by filtration using a microfiltration membrane with a pore size of 0.1~1.0μm and an operating pressure of 0.1~0.3MPa.

[0026] Furthermore, in step S200, the amount of tea residue added is 3-8% of the weight of glutinous rice, the amount of coarse bamboo fiber added is 60-120% of the weight of tea residue, the diameter of the coarse bamboo fiber is 100-500um, the fiber length is 0.5-5cm, and the coarse bamboo fiber needs to be placed in boiling water for high-temperature steaming for 5-10 minutes before use.

[0027] Furthermore, in step S400, the process of separating the tea residue from the distilled lees is as follows:

[0028] First, the lees are dried to a moisture content of less than 10% using mechanical drying or natural sun drying. Then, the tea leaves in the lees are blown out using a wind classifier to collect the fermented tea residue.

[0029] Furthermore, in step S400, the preparation process of tea residue cellulose is as follows:

[0030] 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. The amount of cellulose complex enzyme added is 50-100 ECU / g based on the dry weight of the tea residue. The mixture is then heated to 40-50℃ and reacted with stirring for 3-5 hours. The mixture is then heated to 80-90℃ and kept at this temperature with stirring for 15-30 minutes. After the temperature is maintained, the mixture is filtered and washed with water until neutral. The enzymatically hydrolyzed tea residue is then prepared into an aqueous suspension with a concentration of 5-10 wt%. The suspension is then ground at a speed of 1000-1500 rpm for 10-30 minutes to obtain an aqueous suspension of tea residue cellulose.

[0031] Furthermore, in step S500, the weight ratio of the added tea residue cellulose, tea extract, and base liquor is (0.05~0.15):(10~30):(80~150).

[0032] In addition, trace amounts of soluble alkali metal salts or hydroxides are added, wherein the ratio of the amount of soluble alkali metal salts or hydroxides added to the weight of tea residue cellulose is (0.2~0.6):1.

[0033] The specific process of blending tea and wine is as follows:

[0034] First, the tea residue cellulose obtained in step S400 is added to the tea extract obtained in step S100. After a high-pressure homogenization process for 10-20 minutes, the base liquor obtained in step S300 is slowly added. After the base liquor is added, the tea is homogenized and sterilized again under high pressure and then sealed and bottled to obtain the tea wine product.

[0035] In addition, the present invention also provides a tea wine prepared using the above-described method for preparing tea wine.

[0036] Compared to traditional tea and wine preparation methods, the advantages of this invention are:

[0037] First, using a two-phase extraction solution consisting of an aqueous phase and an oil phase is beneficial for the co-dissolution of polar and non-polar tea components, which can retain more volatile aroma components, improve the extraction rate of functional components of tea, and enhance the aroma layers and health benefits of tea and wine.

[0038] Secondly, a composite system of "glutinous rice + tea filter residue + coarse bamboo fiber" is introduced into the fermentation raw materials. This fermentation system can not only improve the aroma and taste of the base wine through tea filter residue and improve resource utilization, but also use coarse bamboo fiber to form structural support and improve fermentation efficiency.

[0039] Third, drawing on the traditional Yongjia "Laojiuhan" preparation process, a "two-stage fermentation + distillation purification" process is introduced. The two-stage fermentation gives the liquor a mellow aroma and taste, while the temperature control of distillation removes some undesirable fermentation byproducts, such as aldehydes and short-chain fatty acids, while retaining some tea aroma and mellow aroma components. In the end, a tea liquor base with pure flavor and harmonious body is obtained. This not only avoids the problem of strong off-flavors and impurities in traditional tea liquor, but also gives the base liquor good quality stability.

[0040] Fourth, in the blending of tea and wine, tea residue cellulose is prepared using tea residue, and then added to tea extract to form a Pickering system. Distilled base liquor is then slowly added, and finally, high-pressure homogenization is used to improve the system's dispersibility and stability. In this way, not only is the high-value utilization of waste achieved, but the aroma retention, anti-sedimentation and color retention of tea and wine are also enhanced, the shelf life is extended, and the stability and sensory uniformity of tea and wine are improved. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the preparation process of the tea wine described in this invention;

[0042] Figure 2 This is the total ion chromatogram of the aroma components in the tea extract prepared in Example 1 of the present invention;

[0043] Figure 3 This is the total ion chromatogram of the aroma components in the tea extract prepared in Comparative Example 1 of this invention;

[0044] Figure 4 This is the total ion chromatogram of the aroma components in the tea extract prepared in Comparative Example 2 of this invention. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0046] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the 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 exemplary embodiments may have different values.

[0047] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0048] A method for preparing tea wine, comprising the following steps:

[0049] S100, Extraction: Tea leaves are pretreated and enzymatically hydrolyzed, and then the hydrolyzed tea leaves are extracted with a two-phase extract containing an aqueous phase and an oil phase. After extraction, the extract is filtered to obtain tea extract and filter residue.

[0050] S200, Fermentation: Soak glutinous rice, steam it, cool it, and then mix it with the filter residue, coarse bamboo fiber, yeast, and yellow yeast obtained in step S100. Then add water and put it into a vat for the first fermentation for 5-7 days. After that, transfer the fermented product to a jar for the second fermentation for 2-6 months. After the second fermentation, press and filter to obtain the lees and wine.

[0051] S300, Distillation: Take the fermented wine and pour it into a still for slow distillation. During the distillation process, control the temperature of the wine at 85~95℃. The distilled substance is collected after being condensed by a condenser. The collected condensate is the base wine of the tea wine.

[0052] S400, Distillers' grains separation and treatment: Separate tea residue from the distillers' grains, grind the tea residue and prepare tea residue cellulose for later use;

[0053] S500, Blending: Add the tea residue cellulose obtained in step S400 to the tea extract obtained in step S100, stir and mix evenly, then slowly add the base liquor obtained in step S300. After the base liquor is added, the product is subjected to high-pressure homogenization and sterilization, and then sealed and bottled to obtain the tea wine product.

[0054] Compared to traditional tea wine preparation methods, this invention has made the following improvements:

[0055] First, using a two-phase extraction solution consisting of an aqueous phase and an oil phase is beneficial for the co-dissolution of polar and non-polar tea components, which can retain more volatile aroma components, improve the extraction rate of functional components of tea, and enhance the aroma layers and health benefits of tea and wine.

[0056] Secondly, a composite system of "glutinous rice + tea filter residue + coarse bamboo fiber" is introduced into the fermentation raw materials. This fermentation system can not only improve the aroma and taste of the base wine through tea filter residue and improve resource utilization, but also use coarse bamboo fiber to form structural support and improve fermentation efficiency.

[0057] Third, drawing on the traditional Yongjia "Laojiuhan" preparation process, a "two-stage fermentation + distillation purification" process is introduced. The two-stage fermentation gives the liquor a mellow aroma and taste, while the temperature control of distillation removes some undesirable fermentation byproducts, such as aldehydes and short-chain fatty acids, while retaining some tea aroma and mellow aroma components. In the end, a tea liquor base with pure flavor and harmonious body is obtained. This not only avoids the problem of strong off-flavors and impurities in traditional tea liquor, but also gives the base liquor good quality stability.

[0058] Fourth, when blending tea and wine, the preparation method of milk tea and wine is adopted. Tea residue cellulose is prepared by using tea residue, and the tea residue cellulose is added to tea extract to form a Pickering system. Then, distilled base liquor is slowly added, and finally, high-pressure homogenization is used to improve the dispersibility and stability of the system. In this way, not only is the high-value utilization of waste achieved, but also the aroma preservation, anti-sedimentation and color preservation of tea and wine are enhanced, the shelf life is extended, and the stability and sensory uniformity of tea and wine are improved.

[0059] Specifically, step S100 includes:

[0060] S101, Tea pretreatment: Fresh tea leaves are picked and subjected to withering, fixation and crushing to obtain pretreated tea leaves;

[0061] S102, Enzymatic hydrolysis: Add 10-20 times the amount of deionized water to the pretreated tea leaves by weight to prepare a tea suspension. Then add 0.3%-1% of the weight of the tea leaves with a compound enzyme. Stir and hydrolyze at 38-50℃ for 0.5-1.5 hours. After that, raise the temperature to 85-95℃ and perform enzyme inactivation treatment for 5-10 minutes to obtain the enzymatically hydrolyzed tea suspension.

[0062] S103, Preparation of extract: Take the oil phase and water phase at a volume ratio of (2~5):100, then add emulsifier to prepare a two-phase extract;

[0063] S104, Extraction: The enzymatically hydrolyzed tea suspension obtained in step S102 is mixed with the biphasic extract obtained in step S103, wherein the volume ratio of the tea suspension to the biphasic extract is 1:2~3; and under the initial conditions of 40~50℃ and 20~40KPa, after stirring and extracting for 10~20min, the pressure is reduced to 8~12KPa, while the temperature is maintained at 1~3℃ above the boiling point corresponding to the current pressure, and stirred and extracted for 5~10min under this condition to complete the first cycle of extraction. Then, the pressure and temperature are adjusted to the initial state again, and the extraction is repeated for 2~3 cycles to complete the extraction of tea.

[0064] S105, Filtration: After filtering the mixture system after extraction in step S104, tea extract and filter residue are obtained.

[0065] As a preferred example of the present invention, fresh tea leaves are picked according to the standard of "one bud and two leaves".

[0066] As some examples of the present invention, the withering process of fresh tea leaves is as follows: fresh tea leaves are evenly spread on a bamboo mat or withering rack and placed in a sunny or cool and ventilated place to lose moisture naturally for 5 to 10 hours, and the withered tea leaves are obtained.

[0067] As a preferred example of the present invention, the tea leaf fixation method is steam fixation. The specific process is as follows: the withered tea leaves are evenly spread on a conveyor belt, and then high-temperature steam at a temperature of 90~100℃ is quickly applied to the surface of the fresh leaves for 80~100 seconds. After that, the leaves are quickly sent to the cooling conveyor section, cooled and spread out, and then enter the crushing process to avoid steam accumulation and continued steaming, which would cause the tea leaves to turn yellow.

[0068] Compared to traditional methods like drum-type and wok-type fixation, this invention utilizes steam fixation, drawing inspiration from the Japanese sencha (tea-making) process. The tea leaves are placed in high-temperature steam for 80-100 seconds for deep steaming. During this process, the high-temperature steam rapidly inactivates enzymes. Furthermore, due to the longer steaming time, the tea fibers become more fragile, making the active ingredients more easily soluble. This results in a green tea extract, effectively preserving the green color of the tea leaves and exhibiting strong color retention. Consequently, the resulting tea extract and tea wine products have a greenish hue, better meeting consumer expectations. Simultaneously, steam fixation fully utilizes the uniform temperature and rapid penetration of steam to quickly deactivate polyphenol oxidase activity, inhibiting the oxidation of tea polyphenols. It also better preserves water-soluble umami components such as amino acids and sugars, resulting in a final tea wine with a fresh and mellow flavor, richer taste, and higher content of functional components, combining excellent nutritional value with superior taste. Moreover, this steam fixation method is entirely contactless, clean, and hygienic, making it more suitable for modern food-grade standards and industrialized mass production.

[0069] As some examples of the present invention, the tea crushing process is as follows: using equipment such as a knife crusher, hammer crusher, roller crusher, impact crusher, air jet mill, and vibratory mill, the tea is crushed to a particle size ≤1mm through single or multiple crushing processes.

[0070] Preferably, the particle size of the tea leaves after crushing is 0.1~0.5mm.

[0071] As some examples of the present invention, in step S102, the complex enzyme is a complex enzyme composed of cellulase, pectinase, and protease.

[0072] Preferably, the weight ratio of cellulase, pectinase and protease is 2:1:1.

[0073] Preferably, in step S102, before enzymatic hydrolysis, an appropriate amount of acid or alkali solution can be added to adjust the pH of the tea suspension to 5.0-6.5.

[0074] As some examples of the present invention, in step S103, the oil phase substance is fruit-flavored oil and / or vegetable seed oil. The fruit-flavored oil may be one or more of lemon oil, orange peel oil, grapefruit oil, lime oil, bergamot oil, citrus oil, coconut oil, etc., and the vegetable seed oil may be one or more of camellia seed oil, grape seed oil, olive oil, etc. In this case, the tea wine prepared is a slightly emulsified tea wine with fruity or herbal aroma.

[0075] Preferably, the oil phase substance is a mixture of orange peel oil and grape seed oil, or a mixture of bergamot oil and camellia oil, or a mixture of coconut oil and bergamot oil. Relatively speaking, the tea wine prepared by adding these oil phase substances has a more appealing aroma to consumers.

[0076] In this 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 effective components such as volatile oils and fat-soluble aromatics in the tea can be extracted through the oil phase substances in the extract, preserving and enhancing the natural aroma of the tea in the extract, and improving the aroma quality of the prepared tea wine.

[0077] 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 glycerides, sodium stearoyl lactylate (SSL), sucrose fatty acid esters (SE), sorbitol fatty acid esters, etc., and the amount of emulsifier added in the biphasic extract is 0.5~2wt%.

[0078] Furthermore, in step S104, the alternating pressure-heating extraction process, based on enzymatic hydrolysis and biphasic extract, can further promote the full release of the total effective components of tea through the coordination and process control of temperature, pressure, and stirring. Specifically:

[0079] First, during the extraction process, the pressure and temperature are cyclically adjusted so that the extract boils rapidly under reduced pressure and heating conditions, releasing a large number of bubbles and generating explosive vaporization and gas agitation. These rapidly generated bubbles can travel or expand in the cell structure, tearing the tea cell structure and interface membrane, and promoting the release of its internal effective components.

[0080] Secondly, at the same time, the bubbles generated under reduced pressure heating expand, diffuse and burst rapidly in the extract, which can also disturb and break the contact interface between the solvent and plant tissue in the extract, promote good contact between the solvent and plant tissue in the extract, increase the migration rate of the extract from the solid phase to the liquid phase, strengthen the extraction, and promote the leaching of effective components such as tea polyphenols and aromatic substances.

[0081] Third, low-temperature heating extraction can also avoid the destruction of active substances such as tea polyphenols and vitamins by excessively high temperatures, while reducing pigment denaturation and the precipitation of bitter substances, thus improving the taste of tea wine.

[0082] As a preferred example of the present invention, in step S105, the process of filtering the extracted mixture includes:

[0083] First, the mixture after extraction was centrifuged. The centrifuge speed was 5000~8000 r / min and the centrifugation time was 5~15 min. After centrifugation, centrifuged liquid and filter residue were obtained.

[0084] The centrifuged liquid is further filtered using a 5-10μm filter cartridge to initially remove large particles from the centrifuged liquid, while preventing clogging of the microfiltration membrane pores and extending the life of the microfiltration membrane in subsequent use.

[0085] 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 sterilization and impurity removal while retaining active ingredients. After microfiltration, a tea extract with stable aroma and high content of functional components is obtained.

[0086] In this invention, by performing a three-stage filtration process of "centrifugation → primary filtration → microfiltration" on the extract, it is possible to remove large biological macromolecules, pectin, starch and other particles that easily cause turbidity and precipitation in the tea extract, as well as microorganisms such as bacteria and Escherichia coli, while retaining nutrients such as tea polyphenols, caffeine and amino acids in the extract. This not only improves the stability of the tea wine, but also gives the tea wine a good tea flavor and nutritional source.

[0087] Furthermore, in step S200, the amount of tea residue (dry weight) added is 3 to 8% of the weight of glutinous rice (dry weight).

[0088] Furthermore, in step S200, the amount of coarse bamboo fiber (dry weight) added is 60-120% of the weight of the tea dregs, based on the amount of tea dregs (dry weight).

[0089] Furthermore, in step S200, based on the amount of glutinous rice (dry weight) added, the amount of yeast added is 0.5~1.5wt%, the amount of yellow yeast added is 0.3~0.8wt%, and the amount of water added is 90~110wt%.

[0090] Furthermore, in step S200, the amount of water added is 1:(1~1.5) of the glutinous rice (dry weight).

[0091] Preferably, the diameter of the coarse bamboo fiber is 100~500um and the fiber length is 0.5~5cm.

[0092] Preferably, the coarse bamboo fiber needs to be boiled in boiling water for 5-10 minutes before use.

[0093] Preferably, in step S200, the filter residue needs to be washed with water and centrifuged 2-3 times before use.

[0094] To ensure effective extraction, the tea residue obtained after extraction is finely broken. This damages the physical structure of the residue, reduces its aeration, makes it prone to the growth of unwanted microorganisms, and results in low fermentation efficiency. Furthermore, the fine tea residue easily adheres to raw materials such as glutinous rice, forming clumps and agglomerates. This makes the fermentation system viscous and compacted, lacking a porous structure and hindering the escape of fermentation gases. More problematic is that this localized clumping and agglomeration can cause localized oxygen deficiency, leading to the growth of anaerobic bacteria and restricting the metabolism of aerobic / facultative bacteria. This affects alcohol and aroma production, ultimately resulting in off-flavors such as "sourness," "sourness," and "muddy odor."

[0095] To improve this situation, during the first-stage fermentation process, this invention adds an appropriate amount of coarse bamboo fiber. The porous and sturdy nature of the bamboo fiber allows it to form a skeletal structure within the fermentation paste, "opening up" the fermentation substrate at a microscopic scale. This maintains the raw materials in a loose and stable brewing state, improves the fermentation microenvironment, and allows for better oxygen exchange, promoting yeast and microbial growth. Simultaneously, it prevents clumping and other undesirable phenomena during fermentation. Furthermore, the active substances in the coarse bamboo fiber can react with substances in the lees to produce substances with ester and bamboo aromas, resulting in a clearer aroma and a richer taste in the tea wine.

[0096] Furthermore, in step S200, the fermentation time is preferably from after the winter solstice to before the Double Fifth Festival (before the fifth day of the fifth lunar month), the glutinous rice used is preferably Nanxi River late glutinous rice, and the fermentation water is preferably mountain spring water.

[0097] Furthermore, in step S200, the fermentation process requires daily stirring and raking during the initial fermentation.

[0098] As a preferred example of the present invention, in step S200, after the secondary fermentation, the fermented product can be transferred to a supercritical carbon dioxide environment and aged at low temperature under the supercritical carbon dioxide environment. The specific process is described in the relevant prior art and will not be repeated here. The base wine with better flavor after aging is better.

[0099] 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 reduced to 0.5 to 1 month.

[0100] 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:

[0101] First, the lees are dried to a moisture content of less than 10% using mechanical drying or natural sun drying. Then, the tea leaves in the lees are blown out using a wind classifier to collect the fermented tea residue.

[0102] 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 and remove most of the water from the lees, and then hot air is used to dry the lees until the moisture content is <10%.

[0103] Preferably, in step S400, a ball mill, a freeze mill, a hammer mill, a nano-grinding device, etc., can be used to grind the tea residue to a particle size of <100um, and then use it to prepare tea residue cellulose.

[0104] As a preferred example of the present invention, the preparation process of the tea residue cellulose is as follows:

[0105] Mix 1-3 parts by weight of ground tea residue with 20-40 parts by weight of buffer solution with pH 4.6-5.5, and add an appropriate amount of cellulose complex enzyme. The amount of cellulose complex enzyme added is 50-100 ECU / g based on the dry weight of tea residue. Then heat the mixture to 40-50℃ and react with stirring for 3-5 hours. Then raise the temperature of the mixture to 80-90℃ and keep it at this temperature for 15-30 minutes with stirring. After the temperature is maintained, filter and wash with water until neutral. Prepare an aqueous suspension with a concentration of 5-10 wt% from the enzymatically hydrolyzed tea residue. Grind the suspension at a speed of 1000-1500 rpm for 10-30 minutes to obtain an aqueous suspension of tea residue cellulose.

[0106] As some examples of the present invention, the buffer solution is selected from acetate-sodium acetate buffer, citrate-sodium citrate buffer, lactate-sodium lactate buffer, etc.

[0107] As some examples of the present invention, the filtration process in the preparation of tea residue cellulose can be carried out using a filter cloth or filter screen of 10~30um to intercept large particles and fiber blocks. The filtration pressure is generally controlled at 0.1~0.5MPa and the temperature can be maintained at 40~50℃ to avoid damage to the fiber.

[0108] As some examples of the present invention, the aqueous suspension of tea residue cellulose can be prepared into powder by means of vacuum freeze drying or other methods, or it can be stored at a low temperature below 15°C and directly added to tea extract for use.

[0109] Preferably, in step S500, the weight ratio of the added tea residue cellulose, tea extract, and base liquor is (0.05~0.15):(10~30):(80~150).

[0110] 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 as production progresses during the tea wine production process.

[0111] 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 or calcium chloride, is added. The ratio of the amount of soluble alkali metal salt or hydroxide added to the dry weight of tea residue cellulose is (0.2~0.6):1.

[0112] As a preferred example of the present invention, in step S500, when adding a soluble alkali metal salt or hydroxide, the specific process of preparing the tea wine is as follows:

[0113] First, the tea residue cellulose obtained in step S400 is added to the tea extract obtained in step S100. After a high-pressure homogenization process for 10-20 minutes, the base liquor obtained in step S300 is slowly added. After the base liquor is added, the tea is homogenized and sterilized again under high pressure and then sealed and bottled to obtain the tea wine product.

[0114] As some examples of the present invention, in step S500, a high-pressure homogenization process is as follows: the mixture is placed in a high-pressure homogenizer and treated at a pressure of 30~50MPa for 10~20 minutes.

[0115] As some examples of the present invention, in step S500, the secondary high-pressure homogenization process is as follows: the mixture is placed in a high-pressure homogenizer and treated at a pressure of 10~30MPa for 10~20 minutes.

[0116] During the tea-wine blending process, by adding trace amounts of soluble alkali metal salts or hydroxides, the positive charges of the metal cations can be used to form cation bridges. These cation bridges then promote the complexation of tea residue cellulose with negatively charged components in the tea extract, forming CNC-M. + -A ternary complexes, where A refers to negatively charged components in tea extract, such as tea polyphenols, amino acids, polysaccharides, and soluble protein hydrolysates. Compared to tea residue cellulose, the surface of pure tea residue cellulose particles is mainly composed of hydroxyl groups, resulting in limited interfacial activity. This ternary complex, through M... + After bridging, component A, containing functional groups such as phenolic hydroxyl groups, carboxyl groups, and amide groups, has a better affinity for the oil-water interface. Therefore, tea residue cellulose, when passing through M... + After bridging, the surface can adsorb or bond these A components, making the particles more amphiphilic and easier to adsorb at the oil-water interface, thus resulting in better stability of the formed Pickering emulsion. Furthermore, since CNC carries a weak negative charge, and A also carries a negative charge, in M... + The bridging structure creates a spatial barrier, increasing the repulsive force between emulsifier particles. This makes it difficult for the formed complex particles to aggregate, settle, or coalesce at the interface. Simultaneously, on the oil phase surface, CNC-M... +-A complexes can form dense particulate films, constructing particulate adsorption shells with typical Pickering emulsion characteristics, which not only prevent oil droplet fusion but also improve the dispersion uniformity and stability of component A.

[0117] The following specific examples illustrate the tea wine and its preparation method provided by the present invention:

[0118] Example 1

[0119] Preparation of tea extract:

[0120] S101, Tea pretreatment: Fresh tea leaves are picked, and then withered, fixed, and crushed to a particle size of 0.5mm to obtain pretreated tea leaves;

[0121] S102, Enzymatic hydrolysis: Add 15 times the amount of deionized water to the pretreated tea leaves by weight to prepare a tea suspension. Then add 0.5% of the weight of the tea leaves with a compound enzyme. Stir and hydrolyze at 45°C for 1 hour. Then raise the temperature to 90°C and perform enzyme inactivation treatment for 7 minutes to obtain the enzymatically hydrolyzed tea suspension.

[0122] S103, Preparation of extract: Take the oil phase and water phase at a volume ratio of 5:100, then add 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;

[0123] S104, Extraction: The enzymatically hydrolyzed tea suspension obtained in step S102 is mixed with the biphasic extract obtained in step S103, wherein the volume ratio of the tea suspension to the biphasic extract is 1:2; and under the initial conditions of 45℃ and 30KPa, after stirring and extracting for 20min, the pressure is reduced to 10KPa, while the temperature is maintained at 2℃ above the boiling point corresponding to the current pressure, and stirred and extracted for 10min under this condition to complete the first cycle of extraction. Then, the pressure and temperature are adjusted to the initial conditions again, and the extraction is repeated for 2 cycles to complete the extraction of tea.

[0124] S105, Filtration: After filtering the mixture system after extraction in step S104, tea extract and filter residue are obtained.

[0125] Example 2

[0126] Preparation of base liquor:

[0127] After soaking, steaming, and cooling the glutinous rice, mix it with the filter residue obtained from the extraction in Example 1, coarse bamboo fiber, yeast, and yellow yeast. Then add water and put it into a vat for the first fermentation for 7 days. After that, transfer the fermented product to a jar for the second fermentation for 3 months. After the second fermentation, press and filter to obtain the lees and wine. The amount of tea residue added is 6% of the weight of glutinous rice, and the amount of coarse bamboo fiber added is 100% of the weight of tea residue. The diameter of the coarse bamboo fiber is 300 μm and the fiber length is 3 cm. The coarse bamboo fiber needs to be boiled in boiling water for 10 minutes before use.

[0128] After fermentation, the wine is poured into a still and distilled slowly. During the distillation process, the temperature of the wine is controlled at 90°C. The distilled substance is collected after being condensed by a condenser. The collected condensate is the base wine for tea wine.

[0129] Example 3

[0130] Preparation of cellulose from tea residue:

[0131] The tea residue from the fermented lees in Example 2 was separated and ground to a particle size of <100 μm. Three parts by weight of the ground tea residue were mixed with 40 parts by weight of a buffer solution with a pH of 4.6-5.5, and an appropriate amount of cellulose complex enzyme was added. 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 with stirring for 3 hours. The mixture was then heated to 90°C and kept at that temperature with stirring for 20 minutes. After the temperature was maintained, the mixture was filtered, washed with water until neutral, and the enzymatically hydrolyzed tea residue was prepared into an aqueous suspension with a concentration of 10 wt%. The suspension was then ground at 1500 rpm for 10 minutes to obtain an aqueous suspension of tea residue cellulose.

[0132] Examples 4-7

[0133] Preparation of tea wine:

[0134] The tea residue cellulose obtained in Example 3 was added to the tea extract obtained in Example 1. After stirring for 20 minutes to make it evenly mixed, 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. Then, it was sterilized and sealed in a jar to obtain the tea wine product.

[0135] In the process of blending tea wine, when adding soluble alkali metal salts or hydroxides, the mixture of tea extract and tea residue cellulose needs to undergo a high-pressure homogenization treatment for 20 minutes at a pressure of 40 MPa.

[0136] The raw material components of the tea wines in Examples 4-7 are shown in Table 1 below:

[0137] Table 1 Raw material components of tea wine

[0138]

[0139] Comparative Example 1

[0140] Preparation of tea extract:

[0141] The only difference between it and Embodiment 1 described above is that:

[0142] The extraction process in step S104 is as follows: the enzymatically hydrolyzed tea suspension prepared in step S102 is mixed with the biphasic extract prepared in step S103, and the tea is extracted by stirring for 60 minutes under the initial conditions of 45℃ and 30KPa.

[0143] Comparative Example 2

[0144] Preparation of tea extract:

[0145] The only difference between it and Embodiment 1 described above is that:

[0146] 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 tea suspension to deionized water is 1:2; then, under the initial conditions of 45℃ and 30KPa, after stirring and extraction for 20 minutes, the pressure is reduced to 10KPa, while the temperature is maintained at 2℃ above the boiling point corresponding to the current pressure, and after stirring and extraction for 10 minutes under this condition, the first cycle of extraction is completed. Then, the pressure and temperature are adjusted to the initial conditions again, and the extraction is repeated for 2 cycles to complete the extraction of tea.

[0147] Comparative Example 3

[0148] Preparation of base liquor:

[0149] The only difference between it and Example 2 above is that no coarse bamboo fiber was added during the fermentation process, and it was found that it slightly deposited and clumped during the fermentation process compared with Example 2.

[0150] Experimental Example 1

[0151] Aroma component detection and analysis:

[0152] 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 are shown below. Figures 2-4As shown, the preparation process of the detection solution is as follows: Take 200 mL of tea extract, add 100 mL of organic solvent to extract three times, then combine the organic phases, and concentrate the organic phase to 10 mL by rotary evaporation at 32 °C. Then add an appropriate amount of anhydrous sodium sulfate and let it stand in a refrigerator at 2 °C for 10 h. Then concentrate the sample to 1.5 mL using a nitrogen blow-dryer before analysis.

[0153] The mass spectrometry data of each component were analyzed and retrieved using the NIST11 database. In addition, relevant literature was consulted to further determine the main detected substances. Peak area normalization analysis was used to determine the relative content of each aroma component. The analysis results are shown in Table 2 below.

[0154] Table 2. Detection and analysis results of major aroma components in tea extract.

[0155]

[0156] Experimental Example 2

[0157] Sensory evaluation of tea and wine:

[0158] The appearance, aroma, and taste of tea wine are evaluated using sensory assessment. The sensory scoring criteria for tea wine are shown in Table 3 below. The sensory assessment of tea wine is conducted by relevant professionals.

[0159] Table 3 Sensory Evaluation Criteria for Tea and Wine

[0160]

[0161] The sensory evaluation results of the tea wines prepared in Examples 4-7 are shown in Table 4 below:

[0162] Table 4 Sensory Evaluation Results of Tea and Wine

[0163]

[0164] Experimental Example 3

[0165] Stability testing of tea and wine:

[0166] Stability testing includes tests for freeze treatment, biological treatment, and photo-oxidative stability, among which:

[0167] The freezing process involved placing the tea wine under freezing conditions for 24 hours, then removing the sample and measuring its color and transmittance.

[0168] Biological treatment involved letting the tea wine stand at 30°C for 72 hours, followed by measuring the color and transmittance of the sample.

[0169] The photo-oxidation stability test involved letting the tea wine stand under sunlight for 24 hours, while a control experiment was conducted indoors to measure the color and transmittance of the samples.

[0170] The above colorimetric measurements were taken at 430nm, with water as a blank.

[0171] The measurement results are shown in Table 5 below:

[0172] Table 5. Results of stability tests for tea and wine after freezing.

[0173]

[0174] Table 6 Results of stability test of tea wine after biological treatment

[0175]

[0176] Table 7 Results of photo-oxidative stability test of tea and wine

[0177]

[0178] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for preparing tea wine, characterized in that, Including the following steps: S100, Extraction: Tea leaves are pretreated and enzymatically hydrolyzed, and then the hydrolyzed tea leaves are extracted with a two-phase extract containing an aqueous phase and an oil phase. After extraction, the extract is filtered to obtain tea extract and filter residue. S200, Fermentation: Soak glutinous rice, steam it, cool it, and then mix it with the filter residue, coarse bamboo fiber, yeast, and yellow yeast obtained in step S100. Then add water and put it into a vat for the first fermentation for 5-7 days. After that, transfer the fermented product to a jar for the second fermentation for 2-6 months. After the second fermentation, press and filter to obtain the lees and wine. S300, Distillation: Take the fermented wine and pour it into a still for slow distillation. During the distillation process, control the temperature of the wine at 85~95℃. The distilled substance is collected after being condensed by a condenser. The collected condensate is the base wine of the tea wine. S400, Distillers' grains separation and treatment: Separate tea residue from the distillers' grains, grind the tea residue and prepare tea residue cellulose for later use; S500, Blending: Add the tea residue cellulose obtained in step S400 to the tea extract obtained in step S100, stir and mix evenly, then slowly add the base liquor obtained in step S300. After the base liquor is added, the product is subjected to high pressure homogenization and sterilization, and then sealed and bottled to obtain the tea wine product. Step S100 includes: S101, Tea pretreatment: Fresh tea leaves are picked and subjected to withering, fixation and crushing to obtain pretreated tea leaves; S102, Enzymatic hydrolysis: Add 10-20 times the amount of deionized water to the pretreated tea leaves by weight to prepare a tea suspension. Then add 0.3%-1% of the weight of the tea leaves with a compound enzyme. Stir and hydrolyze at 38-50℃ for 0.5-1.5 hours. After that, raise the temperature to 85-95℃ and perform enzyme inactivation treatment for 5-10 minutes to obtain the enzymatically hydrolyzed tea suspension. S103, Preparation of extract: Take the oil phase and water phase at a volume ratio of (2~5):100, then add an emulsifier to prepare a two-phase extract; the oil phase substance is fruit oil and / or vegetable seed oil; S104, Extraction: The enzymatically hydrolyzed tea suspension obtained in step S102 is mixed with the biphasic extract obtained in step S103. Under the initial conditions of 40-50℃ and 20-40KPa, the mixture is stirred and extracted for 10-20 minutes. Then, the pressure is reduced to 8-12KPa, while the temperature is maintained 1-3℃ above the boiling point corresponding to the current pressure. The mixture is stirred and extracted for 5-10 minutes under these conditions to complete the first cycle of extraction. After that, the pressure and temperature are adjusted back to the initial conditions, and the extraction is repeated for 2-3 cycles to complete the extraction of the tea. S105, Filtration: After filtering the mixture system after extraction in step S104, tea extract and filter residue are obtained. In step S400, the preparation process of tea residue cellulose is as follows: Mix 1-3 parts by weight of the ground tea residue with 20-40 parts by weight of a buffer solution with a pH of 4.6-5.5, and add an appropriate amount of cellulose complex enzyme. The amount of cellulose complex enzyme added is 50-100 ECU / g based on the dry weight of the tea residue. Then heat the mixture to 40-50℃ and react with stirring for 3-5 hours. Then raise the temperature of the mixture to 80-90℃ and keep it at that temperature for 15-30 minutes with stirring. After the temperature is maintained, filter and wash with water until neutral. Prepare an aqueous suspension with a concentration of 5-10 wt% for the enzymatically hydrolyzed tea residue. Grind the suspension at a speed of 1000-1500 rpm for 10-30 minutes to obtain an aqueous suspension of tea residue cellulose. In step S500, the weight ratio of the added tea residue cellulose, tea extract, and base liquor is (0.05~0.15):(10~30):(80~150).

2. The method for preparing tea wine according to claim 1, characterized in that, In step S101, the tea leaf fixation process is as follows: After the tea leaves have withered, they are spread evenly on a conveyor belt and then subjected to high-temperature steam at 90-100℃ for 80-100 seconds. After that, they are quickly sent to the cooling conveyor section, cooled and spread out, and then enter the crushing process.

3. The method for preparing tea wine according to claim 1, characterized in that, In step S105, the process of filtering the extracted mixture includes: First, the mixture after extraction was centrifuged. The centrifuge speed was 5000~8000 r / min and the centrifugation time was 5~15 min. After centrifugation, centrifuged liquid and filter residue were obtained. The centrifuged liquid is further filtered using a 5-10μm filter cartridge to initially remove large particles from the centrifuged liquid; Then, the tea extract was obtained by filtration using a microfiltration membrane with a pore size of 0.1~1.0μm and an operating pressure of 0.1~0.3MPa.

4. 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 coarse bamboo fiber added is 60-120% of the weight of tea residue, the diameter of the coarse bamboo fiber is 100-500um, the fiber length is 0.5-5cm, and the coarse bamboo fiber needs to be placed in boiling water for high-temperature steaming for 5-10 minutes before use.

5. 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 to a moisture content of less than 10% using mechanical drying or natural sun drying. Then, the tea leaves in the lees are blown out using a wind classifier to collect the fermented tea residue.

6. The method for preparing tea wine according to claim 1, characterized in that, In step S500, calcium chloride is also added, and the ratio of the amount of calcium chloride added to the weight of tea residue cellulose is (0.2~0.6):

1. The specific process of blending tea and 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 process for 10-20 minutes, the base liquor obtained in step S300 is slowly added. After the base liquor is added, the tea is homogenized and sterilized again, and then sealed and bottled to obtain the tea wine product.

7. The tea wine prepared according to the method for preparing tea wine according to any one of claims 1 to 6.

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