Preparation method and preparation equipment of composite cyclocarya paliurus black tea

Abstract

The invention relates to the technical field of tea processing, and discloses a composite cyclocarya paliurus black tea preparation method, which comprises: carrying out thermal shock treatment on cyclocarya paliurus fresh leaves to inactivate an endogenous enzyme system to obtain a biochemical substrate, respectively carrying out rolling treatment on the biochemical substrate and the first batch of fresh tea leaves, carrying out fusion rolling on the rolled product, and carrying out first-stage fermentation to obtain the composite cyclocarya paliurus black tea. In the fermentation process or after the fermentation process, rolling products of fresh tea leaves in a subsequent batch are supplemented for subsequent fermentation, and finally drying is performed. The fresh cyclocarya paliurus leaves are subjected to thermal shock to inactivate an endogenous enzyme system and then subjected to differential rolling with the fresh tea leaves, so that a fermentation environment singly dominated by tea polyphenol oxidase is constructed; according to the method, enzyme system pretreatment and physical wall breaking are separated, and the problems of rolling mismatching and enzyme system interference caused by different physical characteristics of raw materials are avoided.

Description

Technical Field

[0001] This invention relates to a method and equipment for preparing compound Qingqianliu black tea, belonging to the field of tea processing technology. Background Technology

[0002] Currently, rolling is the core process that determines quality. Its technical mission is not simply physical breakage, but rather to break down cell walls to allow intracellular substrates such as polyphenols to mix thoroughly with polyphenol oxidase (PPO), thus establishing the biochemical foundation for subsequent fermentation, i.e., enzymatic oxidation. The common practice in this field is to pursue a moderate and uniform cell breakage rate to ensure the stability and controllability of the fermentation process. With the increasing market demand for compound functional tea products, technicians are trying to introduce plant raw materials with different physical properties, such as fresh leaves of Eucommia ulmoides, into the standard preparation process of black tea. The industry's conventional operation is to mix withered tea leaves with fresh Eucommia ulmoides leaves and send them into the same rolling machine for co-rolling using standard black tea rolling parameters. In practice, this technical approach has encountered a process incompatibility problem caused by the fundamental difference in the physical properties of the two raw materials. Tea leaves are relatively tender, while Eucommia ulmoides leaves are usually more leathery and have coarser fibers.

[0003] Under the same mechanical stress, this mismatch in physical properties leads to a process consequence of a mismatch between physical action and biochemical preconditions: excessive kneading of tea leaves causes excessive cell damage, resulting in an overly vigorous and uncontrollable subsequent fermentation process; while the tough cell walls of *Cyclocarya paliurus* are not effectively broken down, resulting in insufficient kneading and a large amount of its contents being locked inside the cells and unable to be released; even if the two are processed separately and then mixed, with the tea leaves prepared according to the black tea process and the *Cyclocarya paliurus* prepared according to the green tea process and then dry-mixed, only a physical flavor superposition can be achieved, but the two matrices cannot be truly integrated at the biochemical level; if the separately kneaded wet tea leaves are mixed for fermentation, the optimal activity conditions of the endogenous enzyme system of *Cyclocarya paliurus* and the polyphenol oxidase system of tea leaves are different, and the mixing of the two will cause uncontrollable biochemical interference, which will inhibit the normal fermentation of black tea, resulting in a product that is just a mixture of inferior black tea and unconverted *Cyclocarya paliurus*, with the raw grass and medicinal taste of *Cyclocarya paliurus* retained, while the mellow sweetness of black tea is completely lost.

[0004] This problem of mismatch between physical processing and incompatibility with biochemical reactions is prevalent in existing technologies and has not been effectively solved. For example, Chinese invention patent CN115191502A discloses a method for preparing Eucommia ulmoides compound functional black tea, which mixes Eucommia ulmoides leaves with similar physical properties to Eucommia ulmoides leaves and Eucommia ulmoides leaves, and adopts a process of first fixing and then fermentation after spreading and drying. This technical approach has a fundamental flaw: this scheme continues the technical formula of co-kneading raw materials with different toughness, which will inevitably face the problems of uneven kneading and mismatch of cell wall breaking; setting a high-temperature fixing step before the fermentation process will completely deactivate the core enzyme system of black tea transformation in the raw materials, polyphenol oxidase, causing the subsequent fermentation process to lose the biochemical basis of enzymatic reaction.

[0005] Therefore, the technical problem to be solved by this invention is how to provide a new preparation method that reconstructs the process path at the method level in order to systematically solve the fundamental problem of the mismatch between physical treatment and biochemical reaction, and to construct efficient cross-matrix enzymatic transformation conditions dominated by a single tea enzyme system. Summary of the Invention

[0006] This invention provides a method and equipment for preparing compound Qingqianliu black tea. Its main purpose is to solve the problem of how to achieve suitable physical cell wall breaking for each of the compound raw materials with different physical properties, while constructing controllable enzymatic transformation conditions dominated by a single tea enzyme system.

[0007] To achieve the above objectives, the present invention provides a method for preparing compound Qingqianliu black tea, comprising: Step 101: Perform heat shock treatment on fresh leaves of Eucommia ulmoides to inactivate its endogenous enzyme system and obtain a biochemical matrix. Step 102: Withering treatment is performed on the biochemical substrate and fresh tea leaves; Step 103: Divide the withered tea leaves into the first batch of tea leaves and the subsequent batches of tea leaves. The first batch of tea leaves and the subsequent batches of tea leaves are used as polyphenol oxidase sources. Step 104: Perform the first rolling process on the first batch of fresh tea leaves to obtain the first batch of rolling product containing polyphenol oxidase; Step 105: Perform a second kneading treatment on the withered biochemical matrix to obtain a second kneading product; Step 106: Mix the first batch of kneaded products with the second batch of kneaded products, and use a kneading machine to perform a blending and kneading process under low pressure or no pressure to obtain a blended material. The blending and kneading process constructs a microscopic reaction interface between the polyphenol oxidase and the contents of the biochemical matrix. Step 107: Perform the first stage fermentation of the fused materials; Step 108: During or after the first stage of fermentation, the subsequent batches of fresh tea leaves are subjected to a first rolling process to obtain subsequent batches of rolled products containing fresh polyphenol oxidase. Step 109: Add subsequent batches of kneaded products to the material fermented in the first stage for further fermentation. The fresh polyphenol oxidase released by the subsequent batches of kneaded products replaces the polyphenol oxidase in the first batch of kneaded products and transforms the contents of the biochemical matrix. Step 110: Dry the fermented material.

[0008] Preferably, the drying process in step 110 includes: step 201 applying low temperature and high humidity conditions to the fermented material for a humidification process, which uses humid heat conditions to promote a thermochemical reaction in the material; and step 202 applying high temperature and low humidity conditions to the material for shaping and drying after the thermochemical reaction has occurred.

[0009] Preferably, the heat shock treatment in step 101 is a steam blanching treatment, and the temperature of the heat shock treatment is 95°C. Up to 100 The processing time is 30 to 90 seconds.

[0010] Preferably, the first kneading process in step 104 and the second kneading process in step 105 use different process parameters, wherein the kneading pressure applied in the second kneading process is higher than the kneading pressure in the first kneading process.

[0011] Preferably, the fusion kneading process in step 106 is carried out without applying external pressure to the kneading machine. This fusion kneading process utilizes the tumbling and squeezing action of the kneading machine to force the juice of the first batch of kneaded products and the juice of the second batch of kneaded products to achieve cross-matrix wetting at the microscopic reaction interface.

[0012] Preferably, in step 103, the fresh tea leaves are divided into two to five batches, and the feeding operation in step 109 is performed 30 to 90 minutes after the first stage of fermentation, and the subsequent fermentation time is 60 to 180 minutes.

[0013] Preferably, the low temperature in step 201 is 60°C. Up to 85 High humidity refers to an environment with a relative humidity of 80% to 95% formed by the evaporation of moisture from the material itself. The high temperature in step 202 is 100°C. Up to 120 The transition time between steps 201 and 202 is determined by the moisture content of the material. Determined, when the moisture content satisfy When this happens, step 201 is terminated and step 202 is initiated, wherein... The initial moisture content of the fermented material before entering step 201. For control coefficients, The value range is from 0.4 to 0.6.

[0014] Preferably, the weight ratio of fresh tea leaves to fresh Eucommia ulmoides leaves before withering in step 102 is 1:0.5 to 1:2.

[0015] Preferably, the withering process in step 102 involves controlling the moisture content of both the fresh tea leaves and the biochemical substrate within the range of 55% to 65%. Step 109, after adding the subsequent batches of kneading products, further includes: using a kneading machine to perform a second blending and kneading process on the added materials under low or no pressure conditions. This second blending and kneading process homogenizes and disperses the fresh polyphenol oxidase released by the subsequent batches of kneading products into the fermentation materials.

[0016] A composite Qingqianliu black tea preparation equipment, the preparation equipment includes a thermal shock mechanism, a withering mechanism, a rolling mechanism, a fermentation mechanism, a drying mechanism and a control mechanism; The thermal shock mechanism is used to perform thermal shock treatment on fresh leaves of Eucommia ulmoides to inactivate its endogenous enzyme system and obtain a biochemical matrix. The withering mechanism is used to wither biochemical substrates and fresh tea leaves; The rolling mechanism is used to perform a first rolling process on the first batch of fresh tea leaves separated according to step 103 to obtain a first batch of rolled products; to perform a second rolling process on the withered biochemical matrix to obtain a second rolled product; to mix the first batch of rolled products and the second rolled products and perform a blending rolling process to obtain a blended material; and to perform a first rolling process on subsequent batches of fresh tea leaves to obtain subsequent batches of rolled products. The fermentation mechanism is used to perform a first stage of fermentation on the blended material, and to perform subsequent fermentation after receiving the subsequent batches of rolled products as feed. The drying mechanism is used to dry the fermented material. The control mechanism is used to coordinate the operation of the thermal shock mechanism, withering mechanism, kneading mechanism, fermentation mechanism and drying mechanism.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. By subjecting fresh Cyclocarya paliurus leaves to heat shock treatment, the endogenous enzyme system is deactivated, transforming them into a pure biochemical substrate to be transformed. Differentiated rolling treatment is adopted, with moderate rolling of tea leaves to release polyphenol oxidase, while high-intensity cell wall breaking rolling of the deactivated Cyclocarya paliurus leaves is performed to fully release its contents. This process path separates enzyme pretreatment from physical cell wall breaking, creating a biochemical reaction prerequisite for subsequent mixed fermentation dominated by tea polyphenol oxidase and rich in substrate sources. This method avoids the coexistence of insufficient and excessive rolling due to the different physical properties of the two raw materials, as well as the uncontrolled state of biochemical reaction caused by mutual interference between enzyme systems during fermentation.

[0018] 2. After mixing the first and second kneading products, a fusion kneading process is carried out using a kneading machine under low or no pressure conditions. The technology is no longer cell wall breaking. By using mechanical tumbling and extrusion, forced microscopic wetting of the juices of the two materials is achieved in a high-viscosity, semi-solid material system. A sufficient and effective biochemical reaction interface is built between the enzyme and the cross-substrate substrate, so that the polyphenol oxidase of tea can efficiently contact and act on the contents released by Qingqianliu. This solves the problem of insufficient and incomplete enzymatic conversion reaction caused by low mass transfer efficiency in semi-solid fermentation.

[0019] 3. By using a batch-by-batch rolling and replenishment method for fresh tea leaves, the enzymatic reaction kinetics under high substrate load conditions are actively managed. It is recognized that the catalytic activity of polyphenol oxidase released in a single batch rapidly declines over time when facing the dual substrates of tea leaves and Eucommia ulmoides, resulting in the conversion of Eucommia ulmoides components remaining on the surface. This scheme constructs an enzymatic relay system by replenishing the remaining batches of rolled products at their activity peak during or after the first stage of fermentation. The subsequently added active enzyme source replaces the depleted enzyme source, carrying out deep conversion of the pre-treated substrate, ensuring that highly active enzymes are performing the conversion task throughout the entire fermentation cycle, and the biochemical reconstruction of the bitter precursors of Eucommia ulmoides is thoroughly completed. Attached Figure Description

[0020] Figure 1 This is a flowchart of the enzyme pretreatment and multi-stage fermentation process of the compound Qingqianliu black tea of ​​the present invention. Figure 2 This is a graph showing the stage transition points and moisture content changes in the two-stage drying process of the present invention. Figure 3 This is a schematic diagram of the functional structure and material flow of the compound black tea preparation equipment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. However, the following embodiments are only preferred examples of this invention and are not intended to limit the scope of protection of this invention.

[0022] This invention provides a method and equipment for preparing composite Qingqianliu black tea. The core of this method lies in reconstructing the processing pathway for composite raw materials in the tea manufacturing field. Through a series of precisely controlled steps, it solves the problems of physical processing mismatch and biochemical reaction incompatibility faced by fresh tea leaves and fresh Qingqianliu leaves with vastly different physical properties during processing. The method mainly includes key stages such as enzyme pretreatment of raw materials, differentiated physical cell wall disruption, multi-stage enzymatic fusion fermentation, and dual-mechanism drying and shaping. In the initial state definition of this invention, the raw materials used include fresh tea leaves and fresh Qingqianliu leaves. Fresh tea leaves serve as the core polyphenol oxidase (PPO) source, while fresh Qingqianliu leaves serve as the biochemical matrix source to be transformed. In the specific initial formulation... In this process, the weight ratio of selected fresh tea leaves to fresh *Eucommia ulmoides* leaves can be controlled within the range of 1:0.5 to 1:2. Step 101 involves heat shock treatment of the fresh *Eucommia ulmoides* leaves. The technical purpose of this step is that the endogenous enzyme system contained in the fresh *Eucommia ulmoides* leaves differs in type, activity, and optimal reaction conditions from the polyphenol oxidase system required for black tea fermentation. If they are mixed and fermented without treatment, uncontrollable biochemical interference will occur, inhibiting the normal fermentation of black tea. To construct a controllable fermentation environment dominated solely by tea polyphenol oxidase, this scheme uses heat shock treatment to pretreat the fresh *Eucommia ulmoides* leaves to inactivate their endogenous enzyme system. A preferred implementation method is to use steam fixation treatment, setting the environmental specifications to maintain the treatment temperature at 95°C. Up to 100 The processing time is controlled between 30 and 90 seconds, transforming fresh Cyclocarya paliurus leaves into a non-biologically active biochemical matrix; the thermal shock treatment process parameters in step 101 are set at 95°C. Up to 100 Within the range of 30 to 90 seconds, if the temperature or time is below the lower limit, the heat penetration is insufficient to completely inactivate the endogenous enzyme system of Eucommia ulmoides, leading to uncontrollable biochemical interference in subsequent fermentation, as shown in the data of control group 2 in Example 2. If the temperature or time is above the upper limit, it causes over-ripening of Eucommia ulmoides, causing thermal degradation of its contents such as phenols and sugars, reducing the effective substrate concentration of subsequent enzymatic and thermochemical reactions, and thus affecting the taste and aroma of the finished product.

[0023] In step 102, the *Eucommia ulmoides* material and fresh tea leaves are withered. Withering is a standard procedure in this field, aiming to evaporate moisture from the fresh leaves, soften the leaves, and increase their toughness, making them easier to roll later. Simultaneously, the concentration of intracellular contents increases, laying the material basis for enzymatic reactions. The quantitative indicator for judging this step is the moisture content; both the fresh tea leaves and the biochemical matrix need to be controlled within the range of 55% to 65% to achieve a state suitable for rolling. The following steps 103 to 105 are the core of this invention in solving the physical mismatch problem, namely, differentiated cell wall breaking. Given that the fresh tea leaves are tender and the *Eucommia ulmoides* biochemical matrix fibers are coarse and tough, mechanical stress would inevitably lead to excessive rolling of the tea leaves and insufficient rolling of the matrix. This method divides the withered fresh tea leaves into first-batch and subsequent batches. In step 104, the first-batch fresh tea leaves undergo a first rolling treatment, using conventional rolling pressure in black tea preparation to achieve appropriate cell disruption, release polyphenol oxidase, and obtain the first batch of rolled products containing polyphenol oxidase. In step 1... In step 05, the withered biochemical matrix undergoes a second kneading treatment. The process parameters for this step differ from those in step 104; the applied kneading pressure is higher than that of the first kneading treatment. The aim is to break down the tough cell walls of *Eucommia ulmoides* with high intensity, releasing its locked-in contents and obtaining the second kneading product. Step 106 is crucial for achieving biochemical fusion, namely, the fusion kneading treatment. In the semi-solid viscous system of tea processing, simple physical mixing cannot achieve effective contact between enzymes and the substrate across the matrix, resulting in a bottleneck in mass transfer efficiency. This necessitates the construction of... At the microscopic reaction interface, this step mixes the first batch of rolled product rich in PPO with the second batch of rolled product rich in inclusions. The mixture is then fused and rolled using a rolling machine under low or no pressure. The standard operating procedure (SOP) for this step is that the rolling machine does not apply external pressure. The rolling and squeezing action of the rolling machine forces the juices of the first and second batches of rolled products to achieve cross-matrix wetting in a high-viscosity system. This allows the PPO in the tea leaves to efficiently contact and act on the inclusions released by the Eucommia ulmoides, resulting in a blended material.

[0024] The mechanical parameters, such as pressure and time, for the first kneading treatment in step 104, the second kneading treatment in step 105, and the fusion kneading treatment in step 106 need to be calibrated according to the amount of material fed, the physical state of the raw materials, and the model of the kneading mechanism. In step 104, conventional pressure is applied to the first batch of fresh tea leaves, and the endpoint is determined by monitoring that the leaf cell breakage rate reaches 60% to 70%. In step 105, a pressure higher than that in step 104 is applied to the biochemical matrix, and the endpoint is determined by visual inspection, specifically by the tearing of the coarse fibers of the *Cyclocarya paliurus* matrix and the release of its internal juices. Sufficient overflow is used as the criterion for judgment; in step 106, the material is operated under low pressure or no pressure conditions, and the operation endpoint is determined by monitoring the material state, when the two material juices are evenly mixed, the system viscosity tends to stabilize, and a homogeneous fused material is formed; steps 107 to 109 construct an enzymatic relay system to solve the problem of enzyme activity decay under high substrate loading. Due to the introduction of the *Cyclocarya paliurus* substrate, the total substrate loading of the fermentation system is much higher than that of conventional black tea, and the catalytic activity of single batches of PPO will decay rapidly over time, resulting in incomplete conversion of the bitter precursor of *Cyclocarya paliurus*. This method addresses this issue. The blended materials undergo the first stage of fermentation (step 107). After 30 to 90 minutes of the first stage fermentation, step 108 is initiated to perform the first rolling process on subsequent batches of fresh tea leaves, obtaining subsequent batch rolling products containing fresh polyphenol oxidase at its peak activity. Then, in step 109, the subsequent batch rolling products are added to the materials from the first stage of fermentation; ensuring the newly added enzyme source is evenly dispersed. At this point, the materials after adding the enzyme are subjected to a second blending and rolling process using a rolling machine under low or no pressure conditions, further enhancing the fresh polyphenol oxidase activity. The enzyme replaces the depleted first batch of enzyme source to further transform the initially transformed biochemical matrix contents, and then carries out subsequent fermentation. The time for this subsequent fermentation can be set from 60 minutes to 180 minutes, and the total batch of fresh tea leaves can be divided into two to five batches. Step 110 is to dry the fermented material. Conventional drying processes aim to dehydrate and cannot deal with volatile off-odor substances in the blind zone of PPO enzymatic reaction, namely the raw grass and medicinal smell of Qingqianliu. This method adopts a two-stage drying process and introduces a thermochemical reaction mechanism to reconstruct the aroma.

[0025] The first stage, step 201, is the aroma-inducing treatment, which applies low temperature and high humidity conditions to the fermented material. This humid and hot environment promotes the Maillard reaction and caramelization. The standard operating procedure (SOP) parameters are: low temperature set at 60°C. Up to 85 The high-humidity environment, achieved by restricting ventilation and utilizing the material's own evaporation of moisture, reaches a humidity level of 80% to 95%. This step transforms residual odor precursors into baking and caramel aroma compounds. The second stage, step 202, is shaping and drying. The transition between these two stages is controlled by a deterministic procedure: when the material's moisture content... satisfy When this happens, step 201 is terminated and step 202 is initiated, wherein... The initial moisture content of the material before it enters step 201. The control factor ranges from 0.4 to 0.6. In step 202, high temperature and low humidity conditions are applied, and the standard operating procedure (SOP) parameters are as follows: high temperature is set to 100. Up to 120 This step aims to quickly terminate the thermochemical reaction, fix the newly generated aroma substances, and bring the product to the final drying standard. The present invention also provides a preparation device for implementing the method, which is laid out according to the method logic of the present invention based on the standard configuration of tea processing equipment. It includes: a withering mechanism for performing step 102; a kneading mechanism located downstream for performing the fusion kneading in steps 104, 105, 106, 108, and 109; a fermentation mechanism located downstream for performing the fermentation in steps 107 and 109; and a drying mechanism located downstream for performing step 110. This mechanism is used to achieve the aroma treatment in step 201 and the shaping and drying in step 202. It may also include a compounding mechanism located downstream of the drying mechanism for mixing different batches of compound Qingqianliu black tea products according to a preset ratio to ensure the quality uniformity between batches of the final product.

[0026] Example 1: This example demonstrates the operational simulation of the described technical solution in a typical challenging scenario within the tea manufacturing industry, showcasing the synergistic effect of multiple internal technical features. In the trial production scenario of compound Qingqianliu black tea, the initial challenge is how to process 100kg of fresh tea leaves meeting harvesting standards and 80kg of Qingqianliu fresh leaves with vastly different physical properties, with the goal of producing a high-quality compound black tea with a harmonious flavor and no off-flavors. The operators in this scenario possess standard knowledge in this field, recognizing the physical and biochemical differences between the two raw materials. They abandon the conventional method of directly mixing and kneading the two, instead adopting a seemingly more refined separate processing path. In this trial production path, the operators follow step 1... Inspired by step 01, 80 kg of fresh *Eucommia ulmoides* leaves were steam-sterilized to obtain a biochemical matrix without biological activity. The biochemical matrix and 100 kg of fresh tea leaves were then subjected to standard withering according to step 102, until their moisture content reached approximately 60%. Next, following the differentiated cell-wall breaking principles of steps 104 and 105, the 100 kg of withered tea leaves underwent a first rolling process, while the 80 kg of withered biochemical matrix underwent a second rolling process with higher pressure, yielding first and second rolling products respectively. The two rolling products were then simply mechanically mixed in a mixing tank, spread into a fermentation chamber, and subjected to conventional static fermentation. After fermentation, a standard 110°C process was used. High-temperature drying resulted in three progressively worse technical defects in the final product. First, despite differentiated cell wall breaking, the lack of the fusion and kneading process in step 106 meant that the two high-viscosity, semi-solid kneading products failed to effectively penetrate at the microscopic level. The PPO polyphenol oxidase in the tea leaves and its substrate were encapsulated within the tea juice clumps, while the contents of *Cyclocarya paliurus* were locked within the *Cyclocarya paliurus* juice clumps. The lack of a microscopic reaction interface necessary for semi-solid fermentation meant that PPO primarily catalyzed the fermentation of the tea leaves themselves, with extremely low conversion efficiency for the *Cyclocarya paliurus* contents. Second, at those occasional contact micro-interfaces, the substrate load of *Cyclocarya paliurus*... The 80kg of PPO enzyme source, which is much higher than the 100kg of tea leaves themselves, comes from a single batch of the first rolling product. After converting part of the tea substrate, the catalytic activity rapidly declines when faced with a high load of Eucommia ulmoides substrate. The lack of a feeding mechanism in step 109 leads to premature decline of enzyme activity, causing the conversion of the bitter precursor of Eucommia ulmoides to remain on the surface. Third, due to the failure of the conversion in the first two steps, a large amount of raw green aroma and volatile off-odors of medicinal substances from Eucommia ulmoides remain. The single high-temperature stage of the conventional high-temperature drying step 110 cannot remove them. Instead, these off-odor substances are solidified in the finished product, resulting in the final product exhibiting a disjointed flavor of inferior black tea and unconverted Eucommia ulmoides.

[0027] In comparison, 100 kg of fresh tea leaves and 80 kg of fresh *Eucommia ulmoides* leaves were processed according to the complete method disclosed in this invention. After the aforementioned differentiated cell-wall breaking steps 104 and 105 were completed, the fusion kneading process in step 106 was initiated. The two products were subjected to low-pressure tumbling and extrusion in a kneading machine to create a sufficient microscopic reaction interface between the juices of the two materials. Subsequently, after 45 minutes of the first stage fermentation in step 107, when the activity of the first batch of PPO enzymes began to decline, according to the division in step 103, the reserved second batch of fresh tea leaves, accounting for 50% of the total tea leaves, i.e., 50 kg, was immediately subjected to the first kneading process. This batch of kneading products containing fresh polyphenol oxidase was quickly added to the fermentation material for the second fusion kneading. The PPO enzyme relay system was activated, and the highly active fresh enzyme source replaced the depleted enzyme source, deeply transforming the *Eucommia ulmoides* substrate. After fermentation, the material was sent to the two-stage drying mechanism in step 110. In step 201, at 75 minutes... The material is treated with a 90% relative humidity for 40 minutes to induce a chemical reaction, transforming residual volatile odors into a roasting aroma, until the material's moisture content reaches a certain level. Reduced to initial moisture content 0.5 times When the value is 0.5, immediately switch to step 202 at 110. The final product obtained by shaping and drying under low humidity and strong ventilation conditions exhibits differences in sensory quality. The synergistic effect of the fusion kneading treatment in step 106 and the enzymatic relay feeding in step 109 promotes the full biochemical transformation of the contents of Qingqianliu (bitter precursor) by PPO in the tea leaves, solving the problem of flavor integration. The synergistic effect of the aroma treatment in step 201 and the shaping and drying in step 202, through the introduction of a thermochemical reaction mechanism different from the enzymatic reaction, transforms volatile off-odor substances that PPO cannot handle into high-value roasted and caramel aromas, solving the problem of aroma integration. This synergistic application of enzymatic and thermochemical reactions in the process sequence enables the material basis of the two raw materials to achieve deep biochemical reconstruction within the processing system, ultimately obtaining a complex tea product with mellow taste and rich aroma.

[0028] Example 2: This example sets up one sample group and four control groups to evaluate the effects of the heat shock treatment in step 101, the subsequent fermentation feeding in step 109, and the aroma treatment in step 201 of step 110 on the final sensory quality and key biochemical components of the compound Qingqianliu black tea. The initial state of the experiment is defined as obtaining 250kg of fresh tea leaves and 250kg of fresh Qingqianliu leaves from the same batch, and dividing them into 5 groups, each containing 50kg of fresh tea leaves and 50kg of fresh Qingqianliu leaves. The preparation of the sample group (experimental group) of this invention is carried out according to the method disclosed in the specific implementation method. The key parameters of the SOP procedure are as follows: Step 101, 50kg of fresh Qingqianliu leaves are heated at 98°C. The tea leaves were subjected to thermal shock treatment under steam for 60 seconds to obtain a biochemical matrix. In step 102, 50 kg of fresh tea leaves and the biochemical matrix obtained in step 101 were withered separately until their moisture content was controlled within the range of 60% to 62%. In step 103, the withered 50 kg of fresh tea leaves were divided into a first batch of 25 kg and subsequent batches of 25 kg each. In steps 104-105, the first batch of fresh tea leaves (25 kg) underwent a first rolling treatment at conventional pressure for 45 minutes; the withered biochemical matrix underwent a second rolling treatment at high pressure for 70 minutes. To achieve thorough cell wall breaking; Step 106, mix the first batch of kneaded products with the second batch of kneaded products, and perform pressureless kneading in a kneading machine for 15 minutes; Steps 107-109, perform the first stage fermentation of the blended material for 60 minutes, and then perform the first kneading treatment on 25kg of subsequent batches of fresh tea leaves to obtain subsequent batches of kneaded products; add the supplementary material to the fermented material in Step 109, perform pressureless kneading, and then perform subsequent fermentation for 90 minutes; Step 110 (two-stage drying), execute Step 201, at 80 The material is subjected to a simmering process with a relative humidity of 90% (formed by the evaporation of moisture from the material itself) until the moisture content of the material is detected. Reduce to initial moisture content 0.5 times (i.e.) =0.5), switch to step 202 at 115 The product is shaped and dried under low humidity and strong ventilation conditions, with a final moisture content of less than 6.0%.

[0029] Control Group 1 (Conventional Blending): 50 kg of fresh tea leaves and 50 kg of fresh *Eucommia ulmoides* leaves were mixed and withered together until the moisture content reached 61%. They were then kneaded together for 60 minutes using standard black tea kneading parameters and fermented for 150 minutes under the same temperature and humidity conditions. A 115... Conventional high-temperature drying; Control group 2 (no heat shock): Except for step 101, the fresh leaves of *Eucommia ulmoides* were not subjected to heat shock treatment and were directly withered. All other steps were consistent with the SOP of the sample group of this invention; Control group 3 (no batch replenishment): Except for steps 103, 108, and 109, 50kg of fresh tea leaves were all rolled at once in step 104, and the fermentation in step 107 was a one-time 150-minute process with no subsequent batches of rolled products replenished. All other steps were consistent with the SOP of the sample group of this invention; Control group 4 (conventional drying): Except for step 201 in step 110, the fermented material was not subjected to aroma treatment and was directly entered into step 115. The shaping and drying process was carried out, and all other steps were consistent with the standard operating procedure (SOP) for the sample group of this invention. After all sample groups were prepared, samples were immediately taken for sensory evaluation and biochemical component detection. The sensory evaluation was conducted according to GB / T23776-2018, the sensory evaluation method for tea. Seven professional tea tasters in the field scored the total score (out of 100), aroma and off-flavor (out of 1-5, with 5 being the strongest off-flavor), and taste (bitterness and astringency, out of 1-5, with 5 being the strongest bitterness and astringency). The biochemical components, theaflavins (TF) and thearubigins (TR), were determined by high performance liquid chromatography (HPLC). The average value of the results was taken, and the experimental data are summarized in Table 1.

[0030] Table 1: Comparison of Sensory Quality and Biochemical Components of Each Sample Group

[0031] Data analysis is as follows: Control group 1 (conventional blending) had the worst performance in all indicators, with extremely high scores for aroma and off-odor (4.8) and bitterness (4.9), and extremely low TF (0.28%) and TR (4.1%) content, indicating that conventional blending processing methods in this field cannot handle composite raw materials with vastly different physical and biochemical properties. Control group 2 (no thermal shock) compared to the sample group of this invention had significantly lower TF (0.45%) and TR (5.3%) content than the sample group of this invention (0.98% and 11.2%), and significantly lower off-odor and... The bitterness scores (4.1 and 4.3) remained high, indicating that the presence of endogenous enzymes in *Cyclocarya paliurus* interferes with the PPO-dominated enzymatic oxidation process. Step 101 (thermal shock) is a necessary step to construct a fermentation environment dominated by a single enzyme system. Compared with the sample group of this invention, the aroma and off-flavor score (1.8) of the control group (without batch feeding) was close to that of the sample group of this invention (1.2), but the bitterness score (3.9) was much higher than that of the sample group of this invention (1.4). This result indicates that a single batch of PPO enzyme source is effective in the fermentation of tea and *Cyclocarya paliurus*. When the substrate load of willow is high, the total catalytic amount is insufficient to complete the deep conversion of the bitter precursor of *Cyclocarya paliurus*. The enzymatic relay system constructed in step 109 (subsequent feeding) plays a key role in achieving flavor acclimatization. Compared with the sample group of the present invention, the bitterness score (1.7) of the control group (conventional drying) is close to that of the sample group of the present invention (1.4), and the TF / TR index is also close. However, the aroma and off-odor score (4.3) is much higher than that of the sample group of the present invention (1.2). This data indicates that PPO enzymatic fermentation mainly converts phenolic substances and aroma. The gas transformation mainly involves two different reaction mechanisms involving volatiles. Aroma defects that cannot be solved by enzymatic reactions can only be transformed and reconstructed through the thermochemical reaction introduced in step 201, which involves aroma aging. The sample group of this invention integrates all key steps and achieves the best results in terms of taste, aroma and major biochemical indicators. This shows that step 101 enzyme pretreatment, step 109 enzymatic relay and step 201 thermochemical transformation have an indispensable synergistic effect in solving different technical problems such as enzyme interference, enzyme activity sustainability and aroma blind spots.

[0032] Example 3: This example combines Figures 1 to 3 This describes a method and equipment for preparing a compound Qingqianliu black tea, such as... Figure 1As shown in the diagram, raw material A, fresh leaves of *Eucommia ulmoides*, undergoes heat shock treatment in step 101 to inactivate its endogenous enzyme system and obtain a biochemical matrix. These, along with raw material B, fresh tea leaves, undergo withering in step 102 to control the moisture content to between 55% and 65%. After withering, the materials are separated and enter step 105 for a second rolling process involving high-pressure intensified cell wall breaking to produce a second rolling product. The tea leaves, on the other hand, enter step 103 for batch processing to produce the first and subsequent batches. The first batch of tea leaves enters step 104 for a first rolling process involving moderate cell wall breaking to release PPO, producing the first batch rolling product. The two rolling products from steps 104 and 105 are then processed in step 10... 6. The tea leaves are kneaded and fused to form a microscopic reaction interface and obtain a blended material. The subsequent batches of tea produced in step 103 are fed into step 108 to prepare feedstock to release fresh PPO. After the blended material from step 106 undergoes the first stage of fermentation in step 107, the feedstock produced in step 108 is added in step 109 to carry out subsequent fermentation and produce fermented material. The material then enters a two-stage drying stage. The aroma treatment in step 201 is performed under low temperature and high humidity conditions, with the mechanism being a thermochemical reaction. When the preset moisture content threshold is reached, the drying conditions are automatically switched to high temperature and low humidity in step 202 to fix the aroma, ultimately obtaining a compound Qingqianliu black tea product.

[0033] like Figure 2 As shown, the drying time (in minutes) is plotted on the horizontal axis, and the moisture content (in percent) is plotted on the vertical axis. Three curves clearly illustrate the change in material moisture content under different process control coefficient k values: specifically, the k=0.7 transition point, the k=0.5 transition point, and the k=0.3 transition point. This visually demonstrates how the control coefficient k determines the trigger moment for switching from the aroma-inducing stage to the shaping and drying stage. Figure 3 As shown, the equipment uses fresh Cyclocarya paliurus leaves and fresh tea leaves as initial inputs and a compound black tea product as the final output. Its functional structure includes: a heat shock mechanism to inactivate the endogenous enzyme system of Cyclocarya paliurus; receiving and processing the fresh Cyclocarya paliurus leaves before sending them to a withering mechanism; a withering mechanism to regulate the moisture content of the materials; receiving materials from the heat shock mechanism and fresh tea leaves; materials flowing out of the withering mechanism and entering a rolling mechanism for differentiated cell wall breaking and blending rolling; a fermentation mechanism for multi-stage enzymatic fermentation and feeding operations; and finally, a drying mechanism for two-stage drying, aroma enhancement, and shaping, producing the compound black tea product. The equipment also includes a central control mechanism to coordinate the operation of each mechanism, execute preset process parameters, and connect to all the above functional mechanisms via control signals.

[0034] Example 4: This example uses gradient experiments to determine the key control coefficients for two-stage drying. In tea manufacturing practice, calibration is carried out. The value is used to determine the transition time from step 201, the aroma treatment, to step 202, the shaping and drying, and is determined by the moisture content of the material. Reduced to initial moisture content A specific proportion, namely To trigger termination; if If the value is set too high, the steeping time will be too short, the thermochemical reaction will be insufficient, and the green aroma and medicinal substances of *Cyclocarya paliurus* will not be sufficiently transformed; if... If the value is set too low, the simmering time will be too long, and the material will be over-cooked in a high temperature and humidity environment, easily producing an unpleasant musty or cooked soup smell; the initial state of the experiment is defined as: taking a batch of 100kg of material that has completed step 109, its initial moisture content is The moisture content was measured to be 72.5%. The batch of material was divided into 5 groups, each containing 20 kg, designated as test groups A through E. The test environment was defined as a drying system equipped with online weight monitoring and programmed control, capable of real-time monitoring of the material's moisture content. and in Achieve the preset When the threshold is reached, the process parameters are automatically set from step 201 to 80. The relative humidity is 90%, so switch to step 202 and set it to 115. Low humidity and strong ventilation; during the experiment, control coefficients were set for the transition times of test groups A to E respectively. The values ​​are 0.7, 0.6, 0.5, 0.4, and 0.3, among which... =0.6 to 0.4 is within the defined range, while =0.7 and =0.3 is the out-of-range control group; the drying process of the 5 groups of materials is started synchronously in completely identical equipment, and the control system determines the drying process according to their respective parameters. The system automatically completes two-stage drying. After drying, sensory evaluation is conducted on each group of samples, focusing on the baking / caramel aroma (out of 5 points, 5 points being the strongest) and musty / off-flavor (out of 5 points, 5 points being the strongest) targeted in step 201. The overall sensory score is given, and the results are shown in Table 2.

[0035] Table 2: Drying Conversion Coefficient Table of Gradient Experiment Results on the Influence of Values ​​on Aroma Quality

[0036] Table 2 presents the data. The non-linear relationship between the value and aroma quality, experimental group A ( =0.7) Due to premature switching to high-temperature drying and the shortest aging time, the thermochemical reaction was severely insufficient, resulting in a very weak roasting aroma score of 1.5, and the finished product exhibited a distinct raw, grassy aroma; Experimental group B ( =0.6), C ( =0.5) and D( =0.4) all received good roasted aroma scores of 3.8 to 4.8, indicating that in this Within the specified range, all thermochemical reactions were effectively activated; experimental group C ( =0.5) achieved the best balance between the roasted aroma score (4.8) and the musty smell score (1.1), with the highest total score (91.2); experimental group D ( The baking aroma score of E (=0.4) at 4.6 is still good, but the musty odor score of 2.5 starts to rise significantly, indicating that the aging time has been too long and off-flavors have begun to appear; The off-flavor score (=0.3) increased sharply to 4.7, while the roasted aroma score decreased from 3.5, indicating that the material was exposed to humid and hot conditions for too long, resulting in over-cooking and disrupting the overall aroma harmony. This data from the calibration procedure confirms... The choice of value is a key technical trade-off point in balancing aroma transformation and suppressing off-odors in the process, with the working window between 0.4 and 0.6.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a composite Cyclobalanopsis glauca black tea, characterized in that, include: Step 101: Perform heat shock treatment on fresh leaves of Eucommia ulmoides to inactivate its endogenous enzyme system and obtain a biochemical matrix. Step 102: Withering treatment is performed on the biochemical substrate and fresh tea leaves; Step 103: Divide the withered tea leaves into the first batch of tea leaves and the subsequent batches of tea leaves. The first batch of tea leaves and the subsequent batches of tea leaves are used as polyphenol oxidase sources. Step 104: Perform the first rolling process on the first batch of fresh tea leaves to obtain the first batch of rolling product containing polyphenol oxidase; Step 105: Perform a second kneading treatment on the withered biochemical matrix to obtain a second kneading product; Step 106: Mix the first batch of kneaded products with the second batch of kneaded products, and use a kneading machine to perform a blending and kneading process under low pressure or no pressure to obtain a blended material. The blending and kneading process constructs a microscopic reaction interface between the polyphenol oxidase and the contents of the biochemical matrix. Step 107: Perform the first stage fermentation of the fused materials; Step 108: During or after the first stage of fermentation, the subsequent batches of fresh tea leaves are subjected to a first rolling process to obtain subsequent batches of rolled products containing fresh polyphenol oxidase. Step 109: Add subsequent batches of kneaded products to the material fermented in the first stage for further fermentation. The fresh polyphenol oxidase released by the subsequent batches of kneaded products replaces the polyphenol oxidase in the first batch of kneaded products and transforms the contents of the biochemical matrix. Step 110: Dry the fermented material.

2. The preparation method of the composite Cyclocarya paliurus red tea according to claim 1, characterized in that, The drying process in step 110 includes: step 201 applying low temperature and high humidity conditions to the fermented material for a humidification process, which uses humid heat conditions to promote a thermochemical reaction in the material; step 202 applying high temperature and low humidity conditions to the material for shaping and drying after the thermochemical reaction occurs.

3. The method for preparing a compound Qingqianliu black tea according to claim 1, characterized in that, The heat shock treatment of step 101 uses steam fixation treatment, and the temperature of the heat shock treatment is 95 to 100 , and the treatment time is 30 seconds to 90 seconds.

4. The preparation method of the compound Cyclocarya papillosa red tea according to claim 1, characterized in that, The first kneading process in step 104 and the second kneading process in step 105 use different process parameters, wherein the kneading pressure applied in the second kneading process is higher than the kneading pressure in the first kneading process.

5. The preparation method of the compound Cyclocarya paliurus tea according to claim 1, characterized in that, The fusion kneading process in step 106 is carried out without applying external pressure to the kneading machine. This fusion kneading process uses the tumbling and squeezing action of the kneading machine to force the juice of the first batch of kneaded products and the juice of the second batch of kneaded products to achieve cross-matrix wetting at the micro-reaction interface.

6. The preparation method of the compound Cyclocarya paliurus tea according to claim 1, characterized in that, In step 103, the fresh tea leaves are divided into two to five batches. The feeding operation in step 109 is carried out 30 to 90 minutes after the first stage of fermentation, and the subsequent fermentation time is 60 to 180 minutes.

7. The method for preparing a compound Qingqianliu black tea according to claim 2, characterized in that, The low temperature of step 201 is 60 to 85 The high humidity is the relative humidity of 80% to 95% formed by the evaporation of water in the material itself, the high temperature of step 202 is 100 to 120 The conversion time of step 201 to step 202 is determined by the water content of the material When the water content satisfies , step 201 is terminated and step 202 is started, wherein is the initial water content of the material after fermentation before entering step 201, is a control coefficient, The value range of is 0.4 to 0.

6.

8. The preparation method of the composite Cyclocarya paliurus red tea according to claim 1, characterized in that, In step 102, the weight ratio of fresh tea leaves to fresh Eucommia ulmoides leaves before withering is 1:0.5 to 1:

2.

9. The preparation method of the composite Cyclocarya paliurus red tea according to claim 1, characterized in that, The withering process in step 102 involves controlling the moisture content of both the fresh tea leaves and the biochemical substrate within the range of 55% to 65%. Step 109, after adding the subsequent batches of kneading products, also includes: using a kneading machine to perform a second blending and kneading process on the added materials under low or no pressure conditions. This second blending and kneading process homogenizes and disperses the fresh polyphenol oxidase released by the subsequent batches of kneading products into the fermentation materials.

10. A composite Qingqianliu black tea preparation device, used to implement the composite Qingqianliu black tea preparation method according to claim 1, characterized in that, The preparation equipment includes a thermal shock mechanism, a withering mechanism, a kneading mechanism, a fermentation mechanism, a drying mechanism, and a control mechanism; The thermal shock mechanism is used to perform thermal shock treatment on fresh leaves of Eucommia ulmoides to inactivate its endogenous enzyme system and obtain a biochemical matrix. The withering mechanism is used to wither biochemical substrates and fresh tea leaves; The rolling mechanism is used to perform a first rolling process on the first batch of fresh tea leaves separated according to step 103 to obtain a first batch of rolled products; to perform a second rolling process on the withered biochemical matrix to obtain a second rolled product; to mix the first batch of rolled products and the second rolled products and perform a blending rolling process to obtain a blended material; and to perform a first rolling process on subsequent batches of fresh tea leaves to obtain subsequent batches of rolled products. The fermentation mechanism is used to perform a first stage of fermentation on the blended material, and to perform subsequent fermentation after receiving the subsequent batches of rolled products as feed. The drying mechanism is used to dry the fermented material. The control mechanism is used to coordinate the operation of the thermal shock mechanism, withering mechanism, kneading mechanism, fermentation mechanism and drying mechanism.

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