Preparation method of black tea beverage capable of reducing tea cheese and maintaining flavor and black tea beverage

Abstract

The invention discloses a preparation method of a black tea beverage capable of reducing tea cheese and maintaining flavor and the black tea beverage, and belongs to the technical field of tea beverage processing. The core innovation of the invention lies in that a staged extraction method in the early brewing stage, the middle brewing stage and the later brewing stage is adopted, the brewing time and the brewing temperature of each stage are regulated and controlled, the pH value is regulated and controlled in the middle stage, the obtained tea soup in the three stages is mixed to prepare the black tea beverage, synergistic intervention is performed from the formation mechanism of the tea cheese, and the generation of the tea cheese is reduced from the source. According to the staged extraction method, the problem that extraction efficiency and precipitation control are difficult to consider in a one-step brewing method for preparing the tea beverage is solved, various flavor substances are dissolved out under the optimal condition, flavor imbalance caused by excessive extraction or insufficient extraction is reduced, and the stability of the black tea beverage is improved while the taste and flavor coordination of the black tea beverage is ensured.

Description

Technical Field

[0001] This invention relates to the field of tea beverage processing technology, and more particularly to a method for preparing a black tea beverage that reduces tea creaminess while maintaining flavor, and the black tea beverage itself. Background Technology

[0002] Tea beverages are widely consumed globally due to their natural, healthy, and convenient characteristics. Black tea contains substances such as catechins, caffeine, protein, soluble sugars, theaflavins, and thearubigins. During the brewing process, the dissolution, dispersion, and aggregation of these substances directly affect the colloidal properties of the tea infusion.

[0003] The most prominent technical obstacle in the production and storage of black tea beverages is the "tea cream" problem. Tea cream is a micro-nano-scale precipitate formed when tea infusion is cooled after being brewed at high temperatures. It is composed of substances such as catechins, theaflavins, thearubigins, caffeine, proteins, and soluble sugars, which self-assemble through hydrogen bonding, hydrophobic interactions, and electrostatic interactions. Its formation affects the clarity, appearance, and taste of tea beverages and also leads to the non-selective loss of functional active substances.

[0004] Currently, the production process typically employs methods such as process avoidance, physical removal, and chemical treatment to address the "tea cheese" problem.

[0005] Process avoidance methods involve shortening the brewing time or lowering the brewing temperature to reduce the dissolution of tea cream precursors, but this will significantly reduce the extraction rate and flavor intensity of the tea infusion.

[0006] Physical removal methods involve forcibly removing the tea cream after the tea soup has cooled through techniques such as centrifugation and filtration (e.g., membrane filtration). This approach is considered a "post-processing" method and can lead to the non-selective removal of some flavor and active substances such as catechins, soluble sugars, and caffeine from the tea soup, resulting in a weak flavor and reduced health benefits.

[0007] Chemical treatment involves adding food additives (such as gum arabic) to encapsulate tea nanoparticles, increasing their spatial stability and delaying precipitation. However, the introduction of exogenous food additives can easily affect the flavor of tea beverages and fails to fundamentally intervene in the formation of tea cream, thus constituting a "post-treatment" method.

[0008] Addressing tea curd formation through a "post-treatment" approach has the following drawbacks: 1. Delayed intervention: Existing methods often intervene only after the tea curd has fully formed and precipitated, failing to control its formation mechanism. Furthermore, some flavor compounds are lost during precipitation, resulting in a loss of flavor and a bland taste in the tea infusion. 2. Potential for quality deterioration: The natural formation of tea curd takes a long time, potentially involving chemical transformations and increased microorganisms in the tea infusion, affecting product quality and safety. 3. Difficulty in resolving the conflict between extraction rate and tea curd formation: Extending brewing time helps improve the extraction rate of flavor and active ingredients and enhances the color of the tea infusion, but it also leads to increased tea curd formation. Current technologies struggle to effectively suppress tea curd while maintaining a high extraction rate. 4. High cost and process complexity: High-efficiency membrane filtration or centrifugation equipment has high investment and operating costs, and the filtration membranes are prone to clogging, cleaning, and replacement, increasing production difficulty and cost.

[0009] Therefore, there is an urgent need in this field for a "proactive prevention" method for preparing tea beverages that can intervene in the formation of tea cream from the source and obtain a stable tea soup while ensuring high flavor and extraction rate of active substances. Summary of the Invention

[0010] The main objective of this invention is to provide a method for preparing a black tea beverage that reduces tea cream while maintaining flavor, and to solve the technical problem of difficulty in intervening in the formation of tea cream in tea beverages from the source while ensuring the flavor of the tea beverage.

[0011] To achieve the above objectives, the present invention provides a method for preparing a black tea beverage that reduces tea creaminess while maintaining flavor, comprising the following steps: Pre-brewing stage: Tea leaves and water are mixed to obtain the first tea-water mixture. The first tea-water mixture is brewed for the first time under the time period t0~t1 and the first temperature conditions. After filtration, the first tea residue and the first tea soup are obtained. Mid-brewing stage: The first tea residue and water are mixed to obtain a second tea-water mixture. The second tea-water mixture is brewed for the second time under the conditions of time period t1~t2 and second temperature. During t1~t2, the pH of the second tea-water mixture is adjusted to 4.0~4.5. After the second brewing is completed, the mixture is filtered to obtain the second tea residue and the second tea soup. Later stage of brewing: The second tea residue and water are mixed to obtain the third tea-water mixture. The third tea-water mixture is brewed for the third time under the conditions of time period t2~t3 and third temperature. After filtration, the third tea residue and the third tea soup are obtained. Here, t3 is the total brewing time, and 0=t0<t1<t2<t3.

[0012] Mixing: The first tea infusion, the second tea infusion, and the third tea infusion are cooled and then mixed to obtain the black tea beverage.

[0013] In some embodiments of the present invention, the first temperature ranges from 90°C to 100°C, and the t1 ranges from 0 to 60 seconds, excluding 0.

[0014] In some embodiments of the present invention, the second temperature ranges from 85°C to 90°C, and the t2 ranges from 60s to 240s.

[0015] In some embodiments of the present invention, the third temperature ranges from 80°C to 85°C, and the t3 ranges from 240s to 600s.

[0016] In some embodiments of the present invention, during the period t1 to t2, the pH of the second tea-water mixture is adjusted to 4.0-4.5 using a food-grade acidity regulator, wherein the food-grade acidity regulator includes at least one of citric acid and vitamin C.

[0017] In some embodiments of the present invention, during the middle of the brewing process, the pH of the second tea-water mixture is adjusted to acidic during the period t1a~t1b, where t1a~t1b is 120s~180s.

[0018] In some embodiments of the present invention, the volume ratio of the first tea infusion, the second tea infusion, and the third tea infusion in the black tea beverage is (2~3):(4~5):(1~2).

[0019] In some embodiments of the present invention, the first tea infusion, the second tea infusion, and the third tea infusion are cooled and then mixed, and the pH is adjusted to 5.5-6.5 using sodium citrate to obtain the black tea beverage; And / or, antioxidants are also added to the black tea beverage.

[0020] In some embodiments of the present invention, the average particle size of the tea nanoparticles in the black tea beverage is 100nm~300nm, and the absolute potential value of the black tea beverage is ≥25mV.

[0021] The present invention also provides a black tea beverage, which is prepared by the method described above for preparing a black tea beverage that reduces tea cream while maintaining flavor.

[0022] The beneficial effects that this invention can achieve are: 1. Significantly optimizes the flavor and taste of tea: The phased extraction method of the present invention, which involves the early, middle and late stages, allows various flavor substances in tea leaves to dissolve under optimal conditions. This reduces the problems of over-extraction or under-extraction that occur in one-step brewing of tea beverages, while retaining more flavor substances. This makes the taste of black tea beverages more harmonious and closer to the flavor profile of freshly brewed tea, thus optimizing the quality of black tea.

[0023] 2. Actively inhibit the formation of tea cream at the source: By adjusting the brewing time and temperature at each stage, and controlling the pH of the tea soup to 4.0~4.5 in the middle of brewing, irreversible or semi-irreversible conformational changes / surface modifications of proteins can be induced, reducing the binding of proteins with polyphenols. This reduces the formation of tea cream from the mechanism of formation, significantly reduces the turbidity and sediment of black tea beverages, enhances the colloidal stability of tea soup, and reduces the dependence on subsequent physical removal or chemical enzymatic hydrolysis.

[0024] 3. Maximize the retention of active ingredients in tea: The phased extraction method of early, middle and late stages reduces the non-selective removal of active ingredients by physical filtration (such as membrane filtration), significantly improves the final retention rate of active ingredients such as caffeine and tea polyphenols, and better preserves the health value of black tea beverages.

[0025] 4. Strong applicability of the process: The process framework of this invention has good versatility. It can adjust the brewing time, brewing temperature and the mixing ratio of tea soup at each stage according to the characteristics of different black tea raw materials, so as to achieve targeted optimization and provide a technical basis for the development of different types of black tea beverages. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart of a method for preparing a black tea beverage that reduces tea cream while maintaining flavor according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the time required to brew tea according to an embodiment of the present invention.

[0028] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0032] This invention provides a method for preparing a black tea beverage that reduces tea creaminess while maintaining flavor, and the resulting black tea beverage. (See reference...) Figure 1 The preparation method includes the following steps: S10, Pre-brewing stage: Mix tea leaves and water to obtain the first tea-water mixture. Brew the first tea-water mixture for the first time under the time period t0~t1 and the first temperature conditions. Filter and separate to obtain the first tea residue and the first tea soup. S20, Mid-brewing stage: The first tea residue and water are mixed to obtain the second tea-water mixture. The second tea-water mixture is brewed for the second time under the conditions of time period t1~t2 and second temperature. During t1~t2, the pH of the second tea-water mixture is adjusted to 4.0~4.5. After the second brewing is completed, the mixture is filtered to obtain the second tea residue and the second tea soup. S30. The second tea residue and water are mixed to obtain the third tea-water mixture. The third tea-water mixture is brewed for the third time under the time period t2~t3 and the third temperature conditions. The mixture is then filtered to separate the third tea residue and the third tea soup. Here, t3 is the total brewing time, and 0=t0<t1<t2<t3. S40. Mixing: The first tea infusion, the second tea infusion, and the third tea infusion are cooled and then mixed to obtain the black tea beverage.

[0033] Terminology Explanation: Tea cream: When tea is brewed at high temperature and then cooled, it forms micro-nano precipitates through the self-assembly of substances such as catechins, theaflavins, thearubigins, caffeine, proteins, soluble sugars, and metal ions via intermolecular forces such as hydrogen bonds, hydrophobic interactions, and electrostatic interactions.

[0034] Tea infusion nanoparticles: These refer to nanoscale particles formed during the tea brewing process by substances such as catechins, theaflavins, thearubigins, and caffeine through intermolecular forces. They are an important component of the tea infusion colloidal system and are considered precursors to tea cream, serving as a key indicator for predicting tea cream formation in this invention.

[0035] Tea polyphenols: The general term for polyphenolic substances in tea, including compounds such as catechins, flavonoids, anthocyanins and phenolic acids. They are not only the main contributors to the flavor of tea and important active substances in tea, but also one of the key precursors for the formation of tea cream.

[0036] Flavor compounds in tea: These are the collective term for compounds in tea that impart and determine its sensory characteristics such as aroma, taste, and mouthfeel. During brewing, they either enter the tea infusion or evaporate into the air. These compounds include tea polyphenols, soluble sugars, caffeine, and amino acids, and are components of tea nanoparticles and tea cream. In tea beverage production, the removal of tea cream often leads to the loss of flavor compounds in the tea infusion.

[0037] Tea active substances: The general term for compounds in tea that have specific physiological regulatory functions and are beneficial to health. They partially overlap with tea flavor substances and are components of tea infusion nanoparticles and tea cream. In the tea beverage production process, the removal of tea cream usually leads to the loss of active substances in the tea infusion.

[0038] Gallocatechin gallate (EGCG): It is the most abundant ester-type catechin monomer among the catechin components of tea polyphenols, accounting for 40%–50% of the total tea polyphenols, and is also one of the key substances involved in the formation of tea cream.

[0039] Zeta potential is an important physical quantity that characterizes the stability of colloidal dispersion systems. It is mainly used to measure the surface charge state of particles. The larger its absolute value, the stronger the electrostatic repulsion between particles and the higher the stability of the system. In this invention, it is used as a key indicator to characterize the surface charge state of tea nanoparticles.

[0040] The black tea beverage prepared by this invention has the following advantages: (1) Significantly optimizes the flavor and taste of the tea soup: The phased extraction method of the early, middle and late stages of this invention can dissolve various flavor substances in the tea under the best conditions, reducing the problem of over-extraction or under-extraction that occurs in one-step brewing of tea beverages, while retaining more flavor substances, making the taste of the black tea beverage more harmonious and closer to the flavor level of freshly brewed tea, thus optimizing the quality of black tea; (2) Actively inhibits the formation of tea cream from the source: By adjusting the brewing time and brewing temperature at each stage, and controlling the pH of the tea soup to 4.0~4.5 in the middle stage of brewing, irreversible or semi-irreversible conformational changes / surface modifications of proteins can be induced, reducing the binding of proteins with polyphenols and inhibiting the formation of tea cream. Theoretically, it reduces the formation of tea cream, significantly reduces the turbidity and sedimentation of black tea beverages, enhances the colloidal stability of tea soup, and reduces the dependence on subsequent physical removal or chemical enzymatic hydrolysis; (3) It maximizes the retention of active ingredients in tea soup: the phased extraction method of early, middle and late stages reduces the non-selective removal of active ingredients by physical filtration (membrane filtration, etc.), significantly improves the final retention rate of active ingredients such as caffeine and tea polyphenols, and better maintains the health value of black tea beverages; (4) It has strong process universality: the process framework of this invention has good universality, and can adjust the brewing time, brewing temperature and tea soup mixing ratio of each stage according to the characteristics of different black tea raw materials, so as to achieve targeted optimization and provide a technical basis for the development of different types of black tea beverages.

[0041] This invention provides a novel "proactive prevention" method that can intervene in the formation of tea cream from the source and obtain a stable tea infusion while ensuring a high extraction rate of flavor substances.

[0042] It is understandable that the total brewing time t3 refers to the sum of the brewing time for the tea-water mixture at the early, middle, and late stages of brewing, excluding the time for filtration and separation and the time for preparing the tea-water mixture.

[0043] refer to Figure 2 t0~t1 refers to the brewing time from the start of brewing at time 0 to time t1, t1~t2 refers to the brewing time from time t1 to time t2, t2~t3 refers to the brewing time from time t2 to time t3, and the total brewing time is t3.

[0044] During tea brewing, soluble sugars and flavonoids dissolve in large quantities in the early stages, while proteins dissolve in relatively small amounts. In the middle stages, proteins and flavonoids dissolve in large quantities, along with catechins and caffeine. Proteins, along with the soluble sugars from the early stages and the catechins and caffeine from the middle stages, readily assemble to form tea cream. In the later stages of brewing, caffeine, theophylline, gallic acid, and catechins further dissolve.

[0045] Based on the dissolution patterns of soluble substances in tea and the assembly and formation patterns of tea cream, this invention divides the brewing extraction into three stages: early, middle, and late. In the early stage, a large amount of soluble sugars and flavonoids dissolve, while protein dissolution is relatively low. In the middle stage, a large amount of protein and flavonoids dissolve, which is the key driving stage for tea cream formation. During this stage, the temperature is controlled at 85℃~90℃ and the pH at 4.0-4.5, actively inducing irreversible or semi-irreversible conformational changes or surface modifications in the dissolved proteins. Simultaneously, changes in protein charge state reduce the exposure of hydrophobic groups, synergistically lowering the binding activity of protein molecules with polyphenols (proteins and polyphenols are generally considered key components in the formation of micro / nano particles such as tea cream), thereby inhibiting tea cream aggregation and precipitation. In the late stage of brewing, caffeine, theophylline, gallic acid, catechins, and other components continue to dissolve, enriching the flavor of the black tea beverage. Therefore, by brewing and extracting tea leaves in three stages—early, middle, and late—and then mixing the tea infusions from the three stages to prepare a tea beverage, the reassembly of tea cheese can be effectively reduced even when all components are mixed in the final product, as some key protein components have been stabilized and modified. At the same time, the effective dissolution of various components in the tea leaves is preserved, thus ensuring the flavor of the black tea beverage.

[0046] In some embodiments, the first temperature ranges from 90°C to 100°C, and t1 ranges from 0 to 60 seconds (excluding 0). For example, the first temperature can be 90°C, 92°C, 95°C, 97°C, 98°C, 99°C, 100°C, etc. The initial brewing time can be 60 seconds, 55 seconds, 50 seconds, 45 seconds, 40 seconds, 35 seconds, 30 seconds, 25 seconds, 20 seconds, 15 seconds, 10 seconds, 5 seconds, etc. High-temperature water at 90°C to 100°C can quickly extract soluble sugars and flavonoids from tea leaves, improving extraction efficiency. By adjusting the initial brewing time to t1 (0-60 seconds), the effective dissolution of the aforementioned soluble sugars and flavonoids is controlled, providing a rich sweetness to the black tea beverage. Simultaneously, it effectively avoids the excessive dissolution of proteins, preventing the large-scale assembly of proteins and soluble sugars into tea cream.

[0047] In some embodiments, the second temperature ranges from 85°C to 90°C, and t2 ranges from 60s to 240s. For example, the second temperature can be 85°C, 86°C, 87°C, 88°C, 90°C, etc., and the intermediate brewing can be carried out until the 60s, 63s, 65s, 68s, 70s, 72s, 75s, 78s, 80s, 90s, 100s, 120s, 150s, 180s, 200s, 210s, 220s, 230s, or 240s. Setting the second temperature to 85℃~90℃ allows for rapid dissolution of proteins and flavonoids, while continuously dissolving catechins, caffeine, and other components. Furthermore, synergistically with the tea infusion pH of 4.0~4.5, it induces irreversible or semi-irreversible conformational changes or surface modifications in proteins, preventing excessive binding of proteins to polyphenols such as catechins and thus inhibiting the aggregation and precipitation of tea cream. Extending the second brewing time to 60s~240s allows for the full dissolution of these substances, providing a rich and mellow flavor to the black tea beverage.

[0048] In some embodiments, the third temperature ranges from 80°C to 85°C, and t3 ranges from 240s to 600s. For example, the third temperature can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, etc., and the brewing can be continued until the 240s, 245s, 250s, 260s, 270s, 280s, 300s, 400s, 500s, 600s, etc. The third brewing time t3 of 240s to 600s can further precipitate water-soluble polysaccharides and amino acids, and continuously dissolve caffeine, theophylline, gallic acid, catechins, especially ester-type catechins, providing sufficient caffeine flavor to the black tea beverage.

[0049] In some embodiments, during the period t1 to t2, the pH of the second tea-infusion mixture is adjusted to 4.0 to 4.5 using a food-grade acidity regulator at 85°C to 90°C. The food-grade acidity regulator includes at least one of citric acid and vitamin C. The acidic environment, in conjunction with the brewing temperature, induces irreversible or semi-irreversible conformational changes or surface modifications in the dissolved proteins, reducing the binding activity of proteins with polyphenols and inhibiting the self-assembly formation pathway of tea cream, which is maintained even in subsequent pH increases and cooling environments.

[0050] In some embodiments, refer to Figure 1During the period t1a~t1b, the pH of the second tea-water mixture is adjusted to be acidic, and t1a~t1b is 120s~180s. That is, the pH can be adjusted to 4.0~4.5 at any time point between 120s and 180s, such as 120s, 125s, 130s, 135s, 140s, 145s, 150s, 155s, 160s, 165s, 170s, 175s, and 180s. Adjusting the second tea-water mixture to be acidic within this range can effectively induce irreversible or semi-irreversible conformational changes or surface modifications in proteins, avoid excessive binding of proteins with polyphenols, and thus inhibit the aggregation and precipitation of tea cream.

[0051] In some embodiments, the first tea infusion, the second tea infusion, and the third tea infusion are mixed after cooling to room temperature to obtain a black tea beverage. The room temperature range can be 25°C to 30°C.

[0052] The proportions of the first, second, and third tea infusions in a black tea beverage can be adjusted according to actual conditions.

[0053] In some embodiments, the volume ratio of the first tea infusion, the second tea infusion, and the third tea infusion in the black tea beverage is (2~3):(4~5):(1~2), which can fully integrate the sweetness of early soluble sugars, the richness of mid-term proteins and flavonoids, and the flavor layers of late catechins and caffeine.

[0054] In some embodiments, the mass ratio of tea leaves to water in the first tea-water mixture is 1:45~55, or it can be 1:50.

[0055] In some embodiments, the ratio of tea leaves to water in the second tea-water mixture is 1:45~55 by mass, and can be 1:50.

[0056] In some embodiments, the ratio of tea leaves to water in the third tea-water mixture is 1:45~55 by mass, and can be 1:50.

[0057] In some embodiments, the first tea infusion, the second tea infusion, and the third tea infusion are mixed and the pH is adjusted to 5.5-6.5 using sodium citrate to obtain a black tea beverage, which ensures the stability of the tea flavor and maintains the colloidal properties of the system.

[0058] In some embodiments, antioxidants are also added to the black tea beverage to prevent the oxidation of phenolic substances such as catechins and to stabilize the average particle size of solid particles in the black tea beverage, preventing the solid particles from agglomerating and growing larger.

[0059] In some embodiments, antioxidants include vitamin C.

[0060] In some embodiments, the antioxidant in the black tea beverage is 0.01% to 0.03% by mass, which helps to stabilize the average particle size of solid particles in the black tea beverage and prevents them from agglomerating and growing larger.

[0061] In some embodiments, the average particle size of the solid particles in the black tea beverage is between 100 nm and 300 nm.

[0062] In some embodiments, the absolute value of the zeta potential of the black tea beverage is ≥25 mV.

[0063] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0064] Example 1 Example 1: The method for preparing a black tea beverage with reduced tea creaminess while maintaining flavor is as follows: Pre-brewing stage: Put 3g of Dianhong Gongfu black tea into 50ml of pure water and steep at a constant temperature of 95℃ for 60 seconds. Then filter to separate the first tea soup and the first tea residue.

[0065] Mid-brewing stage: Mix the first tea residue with 50ml of pure water and brew at a constant temperature of 88℃ for 240s (brewing time is 240s-60s=180s). At 120s, adjust the pH to 4.0-4.5 with food-grade citric acid. Then filter to separate the second tea liquor and the second tea residue.

[0066] Later stage of brewing: Mix the second tea residue with 50ml of pure water and brew at a constant temperature of 82℃ for 400s (brewing time is 400s-240s=160s). Then filter to obtain the third tea soup.

[0067] After the first, second, and third tea infusions have cooled to room temperature (25°C), they are mixed in a volume ratio of 3:5:2. Vitamin C is added at 0.02% of the total mass of the three tea infusions, and the pH is adjusted to 5.5-6.5 with sodium citrate to obtain a black tea beverage.

[0068] Example 2 Example 2 prepared a black tea beverage using the same method as Example 1, except that 3g of Qimen black tea was used instead of Dianhong Gongfu black tea in Example 2.

[0069] Example 3 Example 3 describes the preparation of black tea beverages using the same method as Example 1, except that the first temperature in Example 3 is 100°C, the second temperature is 85°C, and the third temperature is 85°C.

[0070] Example 4 Example 4 prepared a black tea beverage using the same method as in Example 1, except that the pH was adjusted to 4.0-4.5 with food-grade citric acid at 160s.

[0071] Example 5 Example 5 prepared a black tea beverage according to the method of Example 1, except that t2 was the 220th second and t3 was the 500th second.

[0072] Comparative Example 1 Comparative Example 1 prepared a black tea beverage using the same method as in Example 1, except that 3g of Yunnan black tea was brewed once with 150ml of pure water at 100℃ to obtain the black tea beverage, and the brewing time was 400s.

[0073] Performance testing The average particle size range, zeta potential, tea cream content, and the content of flavor substances such as protein, soluble sugar, flavonoids, catechins, and caffeine in the tea infusion of black tea beverages in Examples 1 to 5 and Comparative Example 1 were tested.

[0074] Table 1

[0075] As shown in Table 1, Examples 1 to 5 employed a staged extraction method involving the early, middle, and late stages of brewing. By controlling the conditions at each stage, the tea cream content in the prepared black tea beverages was significantly lower than that in Comparative Example 1, indicating that this method can effectively inhibit the formation of tea cream from a mechanistic perspective. Furthermore, the average particle size of the tea nanoparticles remained between 100 nm and 300 nm, and the absolute value of the Zeta potential was consistently higher than 25 mV, indicating stable particle dispersion and enhanced colloidal system. Regarding flavor and active ingredient retention, after removing the tea cream, the contents of key substances such as protein, soluble sugars, flavonoids, catechins (represented by EGCG), and caffeine in the examples were generally higher than in Comparative Example 1, resulting in a more harmonious flavor profile in the black tea beverages, closer to the flavor profile of freshly brewed tea.

[0076] Comparative Example 1 used a one-step brewing method to obtain tea soup. The tea cream content was too high, and the formation of tea cream could not be effectively controlled. The absolute value of the potential was below 25mV, and the colloidal stability was poor.

[0077] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for preparing a black tea beverage with reduced creaminess and maintained flavor, characterized by, The method comprises the following steps: a pre-brewing stage: mixing tea leaves and water to obtain a first tea-water mixture, and performing a first brewing on the first tea-water mixture under a first temperature condition for a time period t0-t1, and then filtering and separating to obtain first tea residue and first tea soup; a middle brewing stage: mixing the first tea residue and water to obtain a second tea-water mixture, performing a second brewing on the second tea-water mixture under a second temperature condition for a time period t1-t2, and adjusting the pH of the second tea-water mixture to 4.0-4.5 during t1-t2, and then filtering and separating to obtain second tea residue and second tea soup; a post-brewing stage: mixing the second tea residue and water to obtain a third tea-water mixture, performing a third brewing on the third tea-water mixture under a third temperature condition for a time period t2-t3, and then filtering and separating to obtain third tea residue and third tea soup, wherein t3 is the total brewing time, and 0=t0 mixing: mixing the first tea soup, the second tea soup, and the third tea soup after cooling to obtain the black tea beverage.

2. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 1, characterized in that, The first temperature is in the range of 90-100℃, and t1 is in the range of 0-60s, excluding 0.

3. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 1, characterized in that, The second temperature is in the range of 85-90℃, and t2 is in the range of 60-240s.

4. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 1, characterized in that, The third temperature is in the range of 80-85℃, and t3 is in the range of 240-600s.

5. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 1, wherein During t1-t2, the pH of the second tea-water mixture is adjusted to 4.0-4.5 by using a food-grade acidity regulator, which comprises at least one of citric acid and vitamin C.

6. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 5, characterized in that, During the middle brewing stage, the pH of the second tea-water mixture is adjusted to be acidic during t1a-t1b, and t1a-t1b is in the range of 120-180s.

7. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 1, wherein The volume ratio of the first tea soup, the second tea soup, and the third tea soup in the black tea beverage is (2-3):(4-5):(1-2).

8. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to claim 1, wherein The first tea soup, the second tea soup, and the third tea soup are mixed after cooling, and the pH is adjusted to 5.5-6.5 by using sodium citrate to obtain the black tea beverage. And / or, an antioxidant is further added to the black tea beverage.

9. The method of preparing a black tea beverage with reduced tea cream and maintained flavor according to any one of claims 1 to 8, characterized in that, The average particle size of tea soup nanoparticles in the black tea beverage is in the range of 100-300nm, and the absolute value of the zeta potential of the black tea beverage is greater than or equal to 25mV.

10. A black tea beverage, characterized by, The black tea beverage is prepared by the method for preparing a black tea beverage with reduced tea cream and preserved flavor according to any one of claims 1-9.

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