Processing technology and preparation method of Chinese wingnut bud tea

Abstract

This invention relates to a processing technology and preparation method for jujube bud tea, belonging to the field of tea processing technology. The method includes the following steps: washing fresh jujube buds, followed by sequential withering, first rolling, first high-temperature fixation, second rolling and shaping, second fixation, low-temperature baking, and low-temperature baking for aroma enhancement. This invention removes surface impurities and some bitter substances through initial washing, combined with prolonged withering to promote the full transformation of internal substances. The two fixation and two rolling processes stabilize the color and remove off-flavors. Finally, segmented baking enhances the aroma. The resulting jujube bud tea has low bitterness, elegant aroma, clear liquor, and mellow taste, overcoming the problems of traditional jujube bud tea's heavy bitterness, insufficient aroma, and poor palatability. Furthermore, the process is stable and suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, specifically to a processing technology and preparation method for jujube bud tea. Background Technology

[0002] Sour jujube (Ziziphus jujuba) belongs to the genus Ziziphus of the family Rhamnaceae. Its tender buds are rich in protein, amino acids, vitamins, and minerals such as calcium, phosphorus, and iron. They also contain active ingredients such as triterpenoids, chlorogenic acid, and flavonoids. Sour jujube bud tea, processed from these tender buds, has a bright yellow-green liquor and is popular among consumers for its calming, sleep-aiding, and blood pressure-lowering effects. In recent years, with increasing emphasis on the health benefits of natural plant beverages, the market demand for sour jujube bud tea has been growing, indicating a promising future for its industrial development.

[0003] Currently, the processing of jujube bud tea largely follows the production process of conventional green tea, mainly involving basic steps such as picking, withering (or drying), fixation, rolling, and drying. However, due to significant differences in the biochemical composition of jujube bud raw materials compared to ordinary tea leaves—the ester-type catechins and some polyphenolic compounds they contain are prone to enzymatic oxidation during processing, producing a strong bitter taste—and the low-boiling-point volatile components with grassy characteristics (such as quinalvin and quinalvin alcohol) are difficult to fully dissipate under conventional heat processing conditions—jujube bud tea produced using existing processes generally suffers from quality defects such as a strong bitter taste, a noticeable grassy smell, and insufficient aroma. Specifically, existing processes mostly employ a short withering period of 1-2 hours. This allows the polyphenol oxidase and hydrolytic enzyme systems within the buds and leaves to not fully act on the substrate before entering the fixation process, resulting in insufficient conversion of bitterness precursors. The fixation stage is often a single operation, with temperatures typically controlled at around 200℃. This makes it difficult to completely deactivate oxidase activity in a short time, and also prevents secondary correction of color and aroma through subsequent heat treatment. Similarly, the rolling process is primarily a single operation, resulting in uneven cell damage, leading to loose tea leaves and uneven flavor extraction during brewing. The simplistic and repetitive nature of these process parameters makes it difficult to achieve satisfactory results in key quality indicators such as liquor color, aroma, and taste, severely hindering the improvement of jujube bud tea product quality and the large-scale development of the industry. Therefore, developing a stable method for preparing jujube bud tea that effectively reduces bitterness, fully removes grassy odor, enhances aroma quality, and provides a stable process is of significant practical importance. Summary of the Invention

[0004] In order to solve the problems of the prior art, the present invention provides a processing technology and preparation method for jujube bud tea.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: Firstly, a processing method for jujube bud tea, comprising the following steps: S1: Washing the tea: Washing the fresh jujube buds; S2: Withering: After washing the tea, the tea leaves are withered for 20 to 24 hours. S3: First kneading: Kneading time is 6-8 minutes; S4: First high-temperature fixation: temperature 220-260℃, time 2-2.5 minutes; S5: Second kneading and shaping: Kneading time is 5-7 minutes; S6: Second fixation: Temperature is 120-160℃; S7: Low-temperature baking: temperature is 120~140℃; S8: Low-temperature baking for aroma enhancement: temperature is 70-90℃.

[0006] In one specific implementation of the first aspect, the spreading of green grass in step S2 is carried out under cool, ventilated conditions without direct sunlight; The spreading of green leaves in step S2 is used to allow the buds and leaves to lose surface moisture and to fully convert the internal substances, thereby reducing the astringent taste.

[0007] In one specific embodiment of the first aspect, the temperature of the second blanching in step S6 is lower than the temperature of the first high-temperature blanching in step S4. The second blanching step in step S6 is used to further stabilize the color and remove off-flavors.

[0008] In one specific embodiment of the first aspect, the cleaning described in step S1 is used to remove dust, impurities, and some soluble bitter substances from the surface of fresh jujube buds.

[0009] In one specific embodiment of the first aspect, the first kneading in step S3 is used to moderately break down cell tissue in order to facilitate the extraction of flavor during brewing.

[0010] In one specific embodiment of the first aspect, the first high-temperature blanching in step S4 is used to rapidly deactivate oxidase activity, prevent browning of buds and leaves, and remove the green odor.

[0011] In one specific embodiment of the first aspect, the second kneading and shaping in step S5 is used to make the bud and leaf strands firm.

[0012] In one specific embodiment of the first aspect, the low-temperature baking in step S7 is used to reduce moisture and preliminarily set the shape.

[0013] In one specific embodiment of the first aspect, the low-temperature baking for aroma enhancement in step S8 is used to improve the aroma and make the moisture content of the finished product moderate.

[0014] Secondly, a type of jujube bud tea is prepared using a jujube bud tea processing technique.

[0015] The beneficial effects of this invention are as follows: 1. This invention employs a pre-treatment process of washing the tea leaves before spreading them out to allow impurities to be removed from the surface of fresh jujube buds. Simultaneously, the washing process removes soluble bitter precursors attached to the surface of the buds and leaves, laying a clean foundation for subsequent processing. Building upon this, a prolonged spreading treatment allows the polyphenol oxidase system and hydrolytic enzyme system within the buds and leaves to work synergistically under suitable moisture, temperature, and humidity conditions. This promotes the gradual oxidation, degradation, and structural transformation of ester-type catechins, a bitter substance, while simultaneously hydrolyzing proteins into free amino acids and slowly releasing glycosides, aroma precursors. This fundamentally reduces the harshness of the finished product and enhances the freshness and mellowness of the tea liquor. During the rolling process, the gradual physical action of rolling twice is used. The first rolling moderately breaks down the cell wall structure of the leaves, allowing the contents of the cells to be initially exposed. The second rolling further compacts the leaves and balances the degree of cell damage, so that the tea juice overflows evenly and adheres firmly to the leaf surface. This ensures the orderly release of flavor substances during brewing and avoids the cloudiness of the tea soup caused by excessive rolling in one go. In the withering process, this invention adopts a two-stage gradient withering scheme of high temperature followed by medium temperature. The first high-temperature short-time withering causes irreversible inactivation of oxidoreductases such as polyphenol oxidase and peroxidase in a very short time, fundamentally preventing enzymatic browning and ensuring the freshness of the finished product's color. The second medium-temperature withering thoroughly removes residual enzyme activity that may be reactivated due to further cell damage during the first rolling and shaping process. It also promotes the full release of undesirable volatile components such as low-boiling-point chlorophyll and chlorophyll alcohol through gentle heat, while inducing Maillard reactions between amino acids and reducing sugars and thermal degradation of carotenoids to generate pyrazine and furan aroma components with roasted and sweet aromas, thus enabling the tea aroma to leap from grassy to pure and elegant. Finally, through a segmented drying and aroma-enhancing process involving medium-temperature baking followed by low-temperature slow drying, the medium-temperature baking stage promotes the uniform migration of moisture from the inside to the outside of the buds and leaves, achieving initial shaping. The low-temperature slow drying stage maintains the continuous transformation of aroma precursors and the slow enrichment of aroma components under a lower heat load, while precisely controlling the moisture content of the finished product within a suitable range for long-term preservation. These processes are interconnected in their mechanisms of action and closely linked in their sequence: the substances transformed during long-term withering provide a suitable substrate state for subsequent heat processing; the physical action of double kneading ensures the uniformity of heat and moisture conduction; the temperature gradients of the two withering processes stabilize the enzyme inactivation effect and build the aroma foundation; and the segmented drying further consolidates and enhances the synergistic effect of these processes, thus forming an inseparable and complete technical system. Together, they achieve the technical effects of significantly reduced bitterness, elegant and lasting aroma, clear and transparent liquor, mellow and smooth taste, and excellent brewing resistance. 2. This invention systematically matches the temperature ranges and durations of each unit operation—withering, rolling, fixation, and baking—to coordinate the dynamic changes in moisture and the transformation of internal substances in each processing stage. The withering stage uses water control to promote metabolic transformation; the fixation stage uses heat to terminate enzymatic reactions and drive aroma generation; and the baking stage uses continuous low-temperature slow baking to complete drying, shaping, and aroma enrichment. The process conditions of each step are interconnected and mutually dependent, avoiding the defects of conventional processes such as insufficient withering leading to residual grassy smell during fixation, excessive fixation leading to broken strips during rolling, or high-temperature drying leading to aroma loss. The alternating combination of two fixation cycles and two rolling cycles allows the color and aroma of the buds and leaves to be repeatedly corrected and enhanced through secondary heat treatment while the cells are gradually damaged. This effectively overcomes the technical contradiction that a single fixation cycle cannot simultaneously achieve "sufficient enzyme inactivation" and "appropriate aroma development." Furthermore, because the temperature, humidity, and time conditions at each step are controlled within a clearly defined operating window, and each step has clear endpoint determination criteria (such as the degree of leaf softening, stem breakage, and changes in appearance and color), the entire preparation process has good reproducibility and operational controllability, facilitating industrial-scale mass production. The resulting jujube bud tea overcomes the quality defects commonly found in traditional jujube bud tea products, such as strong bitterness, insufficient aroma, and poor palatability. It also exhibits good storage stability, maintaining its flavor and quality without significant deterioration even after prolonged storage at room temperature, making it suitable for large-scale promotion as a daily drinking tea. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0018] like Figure 1 The present invention describes a processing technology and preparation method for jujube bud tea.

[0019] I. Raw Material Selection and Pretreatment 1. Harvesting: Select fresh, disease-free, tender green, and plump jujube buds harvested from April to June each year as raw materials. Buds 2-4 cm in length with 1-3 unfolded leaves are preferred. Processing should be done promptly after harvesting. If immediate processing is not possible, spread the raw materials evenly in a cool, well-ventilated indoor environment with a temperature below 25℃, ensuring the thickness does not exceed 10 cm to prevent overheating and spoilage.

[0020] 2. Washing the Tea: Place the freshly picked jujube buds in a washing container and rinse them repeatedly with running water 2-3 times to remove dust, sand, insect eggs, and other impurities from the surface. Gently stir the buds and leaves during washing to ensure each leaf is thoroughly cleaned. After washing, remove the buds and leaves and drain off excess water. Spread them out in a well-ventilated area until there are no visible water droplets on the surface before proceeding to the next step. This step uses fresh jujube buds as input and produces clean jujube buds with no visible moisture.

[0021] The purpose of rinsing tea is twofold: firstly, to remove surface dust and impurities, thereby improving the cleanliness of the raw materials; secondly, to partially remove soluble bitter substances adhering to the surface of the buds and leaves through rinsing, laying the foundation for reducing the bitterness of the finished product.

[0022] 2. Spreading the Leaves: Evenly spread the cleaned jujube buds on bamboo sieves, bamboo mats, or well-ventilated storage containers. The thickness of the spread leaves should be controlled at 3-8 cm, not too thick, to ensure good ventilation. The spreading environment should be cool, well-ventilated, and free from direct sunlight, with the ambient temperature controlled at 18-25℃ and the relative humidity controlled at 70%-80%. The spreading time is 20-24 hours.

[0023] During the spreading process, the leaves should be gently turned every 4-6 hours to ensure even distribution and prevent localized overheating and spoilage. Spreading continues until the surface moisture of the leaves has fully evaporated, the leaves have softened, the grassy smell has gradually dissipated, and a faint, pleasant fragrance has emerged. After spreading, the moisture content of the leaves will have dropped to 70%-80% (a decrease of 5-10 percentage points compared to fresh leaves), the leaves will have softened, and the grassy smell will have gradually dissipated, giving off a faint, pleasant fragrance.

[0024] The input for this step is freshly washed jujube buds, and the output is jujube buds after being spread out to develop their green color (spread-out green leaves). Spreading out to develop their green color is one of the key processes in this invention: in conventional jujube bud tea processing, the spreading time is usually only 1 to 2 hours, while this invention uses a long spreading time of 20 to 24 hours, which is much longer than conventional processes. The long spreading time allows the substances contained in the buds and leaves (such as polyphenols, flavonoids, etc.) to be fully transformed, while at the same time, the bitter and astringent substances are partially oxidized and degraded, significantly reducing the bitterness and astringency of the finished product and making the taste more mellow.

[0025] 3. First Rolling: Place the withered jujube buds into a rolling machine for the first rolling. The rolling time is 6-8 minutes. During rolling, follow the principle of "light, heavy, light" pressure. That is, start with no pressure (empty rolling) for 1-2 minutes to make the buds and leaves curl initially; then gradually increase the pressure to medium pressure and roll for 3-4 minutes to moderately break down the cell tissue; finally, reduce the pressure and roll lightly for 1-2 minutes to give the tea strips a preliminary shape.

[0026] During the rolling process, the rolling machine speed should be controlled at 40-50 revolutions per minute, and the amount of tea leaves should be 80% to 90% full in the rolling drum. Roll until the buds and leaves are initially curled into strips, the cells are moderately damaged, and a small amount of tea juice overflows and adheres to the leaf surface. The cell damage rate of the first rolling should be controlled at 30%-45%, and the strip formation rate should reach more than 60%.

[0027] The input for this step is the unfolded green leaves, and the output is the leaves after the first rolling. The main purpose of the first rolling is to moderately break down the cell tissue of the buds and leaves, so that the flavor substances such as tea polyphenols and amino acids inside the cells can be easily extracted during subsequent brewing. At the same time, it makes the buds and leaves initially curl into shape, laying the foundation for subsequent shaping.

[0028] IV. First High-Temperature Fixation: After the first rolling, the jujube buds are placed into a fixation device (such as a drum-type fixation machine, tea-frying pan, etc.) for the first high-temperature fixation. The fixation temperature is 220-260℃, and the fixation time is 2-2.5 minutes. The amount of leaves added depends on the equipment model and the heating area, with the principle of ensuring that the buds and leaves are heated evenly during the fixation process.

[0029] During the blanching process, the leaves should be turned quickly to ensure full contact between the buds and the heat source, guaranteeing that each bud and leaf reaches the blanching temperature. Blanching continues until the color of the buds and leaves changes from bright green to dark green, the grassy smell dissipates, a cooked aroma is emitted, the leaf texture softens, and the stems cannot be broken. After blanching, the moisture content of the buds and leaves drops to 50%–60%.

[0030] The input for this step is the leaves from the first rolling stage, and the output is the leaves from the first fixation stage. The purpose of the first high-temperature fixation is to quickly deactivate the activity of polyphenol oxidase in the buds and leaves, preventing enzymatic browning during subsequent processing and maintaining the color of the finished product. At the same time, the high temperature effectively removes the grassy and astringent smells, laying the foundation for the formation of the aroma of the finished tea. Using a high temperature of 220-260℃ for a short time for fixation can quickly deactivate enzyme activity while avoiding scorching of the buds and leaves due to excessive fixation time.

[0031] 5. Second Rolling and Shaping: While the jujube buds are still hot after the first high-temperature fixation, perform a second rolling and shaping. The rolling time is 5-7 minutes. During rolling, the same "light, heavy, light" pressure principle is followed: first, lightly roll for 1-2 minutes to initially shape the tea leaves, then roll with medium pressure for 2-3 minutes to further compact the tea leaves, and finally lightly roll for 1-2 minutes to set the shape.

[0032] The rolling machine speed should be controlled at 40-50 rpm. Roll until the buds and leaves are tightly rolled, uniform in shape, and the color changes from bright green to a bright yellow-green, with tea juice evenly adhering to the leaf surface. The cell damage rate should reach 45%-60% in the second rolling, and the strip formation rate should reach over 80%. After rolling, clumps should be broken up promptly to prevent the tea leaves from becoming too dense and generating heat, which would affect the quality.

[0033] The input for this step is the leaves from the first flushing process, and the output is the leaves from the second rolling process (shaping). The main purpose of the second rolling and shaping is to make the buds and leaves more compact and uniform, improving the appearance quality and brewing stability of the finished tea; at the same time, it further breaks down the cell structure to allow the tea juice to adhere more fully to the leaf surface, increasing the flavor concentration and brewing endurance of the tea soup.

[0034] VI. Second fixation: After the second kneading and shaping, the jujube buds are subjected to a second fixation. The fixation temperature is 120-160℃, and the fixation time is 1.5-2.5 minutes, depending on the moisture content of the buds and leaves and the fixation equipment.

[0035] The temperature for the second fixation is significantly lower than that for the first high-temperature fixation (220–260℃). During the fixation process, the leaves should be turned moderately to ensure even heating. Fixation continues until the color of the leaves stabilizes, off-flavors are removed, and the initial aroma of the tea begins to appear. After the second fixation, the moisture content of the leaves should drop to 40%–50%.

[0036] The input for this step is the leaves from the second rolling, and the output is the leaves from the second fixation. The purpose of the second fixation is to further stabilize the color of the buds and leaves and remove any off-flavors that may have been generated during processing, based on the enzyme activity already deactivated by the first high-temperature fixation; at the same time, the moderate heat promotes the transformation of aroma precursors and enhances the tea's aroma base. The temperature difference between the two fixations (high temperature for the first time, medium temperature for the second) is one of the key technical features of this invention, ensuring both sufficient enzyme deactivation and avoiding the aroma loss that might result from a single high-temperature fixation.

[0037] 7. Low-temperature baking: The jujube buds after the second blanching are baked at a low temperature. The baking temperature is 120-140℃, and the baking time is about 15-25 minutes. The specific time depends on the moisture content of the buds and leaves and the baking equipment.

[0038] During baking, the buds and leaves should be turned occasionally to ensure even heating and prevent localized overheating and scorching. Baking continues until the moisture content of the buds and leaves has further decreased, they feel slightly prickly to the touch, and can be clumped together without crumbling. After low-temperature baking, the moisture content of the buds and leaves should be reduced to 20%–30%.

[0039] The input for this step is the second round of fixation leaves, and the output is low-temperature roasted leaves. The main purpose of low-temperature roasting is to further remove moisture from the buds and leaves, allowing the tea leaves to initially take shape and laying the foundation for subsequent aroma-enhancing roasting.

[0040] 8. Low-temperature roasting for aroma enhancement: The jujube buds, after low-temperature roasting, are then further roasted at a low temperature to enhance their aroma. The roasting temperature is 70-90℃, and the roasting time is 1.5-3 hours. This low-temperature, slow roasting method allows the moisture inside the buds and leaves to slowly dissipate, allowing the aroma components to fully form and be released.

[0041] During the roasting process, turn the tea leaves every 20-30 minutes to ensure even heating. Roast until the buds and leaves are dry, can be easily rubbed into powder, and have a delicate and lasting aroma. After the low-temperature roasting to enhance the aroma, the moisture content of the finished product should be controlled at 4%-7%. After the finished tea has cooled to room temperature, it is sorted, dusted, and packaged.

[0042] The input for this step is low-temperature roasted tea leaves, and the output is finished jujube bud tea. Low-temperature roasting for aroma enhancement is one of the key processes in this invention: slow roasting at a low temperature of 70-90℃ for a long time avoids the destruction of aroma components by high temperatures and allows aroma substances (such as linalool and its oxides) inside the tea leaves to be fully generated and accumulated; at the same time, low-temperature slow roasting can reduce the moisture content of the finished product to a suitable level (4%-7%), which is conducive to long-term storage and less prone to mold. Studies have shown that low-temperature roasting at 70-90℃ can significantly enhance the aroma of tea, reduce the bitterness and astringency of the tea soup, and increase its mellowness.

[0043] IX. Summary of Process Parameters: The inputs, outputs, and key parameters for each step are summarized below: ; Example 1 A method for preparing jujube bud tea, the specific steps of which are as follows: 1. Harvesting and Washing: In mid-May of the same year, select 10 kg of fresh, disease-free, tender green, and plump wild jujube buds (2-4 cm in length, with 1-2 unfolded leaves) as raw materials. Place the harvested fresh jujube buds in a washing trough and rinse them repeatedly with running water three times, gently stirring them with your hands each time to ensure the buds and leaves are fully agitated. After washing, remove them and spread them out in a ventilated place to drain the surface moisture until there are no obvious water droplets on the surface of the buds and leaves.

[0044] 2. Spreading the Leaves: Evenly spread the cleaned jujube buds on a bamboo sieve, with a leaf thickness of approximately 5cm. The spreading environment should be a cool, well-ventilated indoor space without direct sunlight, with the temperature controlled at 20-22℃ and the relative humidity at 75%-78%. The spreading time is 22 hours. During the spreading process, gently turn the leaves every 5 hours to ensure even distribution. At the end of spreading, the surface moisture of the leaves should have fully evaporated, the leaves should have softened, the grassy smell should have significantly decreased, and a faint fragrance should be emitted. Measurements show that the moisture content of the spread leaves is approximately 76%.

[0045] 3. First Rolling: Place the withered jujube buds into a tea rolling machine for the first rolling. The amount of leaves should be about 90% of the rolling drum's volume. The total rolling time is 7 minutes, with the following pressure application: first, roll without water for 1.5 minutes, then lightly press for 2 minutes, then lightly press for 2 minutes, and finally lightly press for 1.5 minutes. The rolling machine speed is 45 revolutions per minute. At the end of rolling, the buds and leaves will be initially curled into strips, the cells will be moderately damaged, and a small amount of tea juice will seep out and adhere to the leaf surface.

[0046] 4. First High-Temperature Blanching: The jujube buds, after the first kneading, are placed into a drum-type blanching machine for the first high-temperature blanching. The blanching temperature is 240℃, and the blanching time is 2 minutes and 15 seconds (2.25 minutes). During the blanching process, the drum rotates continuously to ensure even heating of the buds and leaves. At the end of the blanching, the color of the buds and leaves changes from bright green to dark green, the grassy smell dissipates, and a cooked aroma is emitted. The leaves soften, and the stems do not break easily. Measurements show that the moisture content after the first blanching is approximately 55%.

[0047] 5. Second Rolling and Shaping: While the jujube buds are still hot after the first high-temperature fixation, perform a second rolling and shaping. The total rolling time is 6 minutes, with the following pressure application: light rolling for 1.5 minutes, medium pressure rolling for 2.5 minutes, and finally light rolling for 2 minutes. The rolling machine speed is 45 rpm. After rolling, promptly break up any clumps of tea leaves. At the end of rolling, the buds and leaves should be tightly rolled and uniform, with a bright yellow-green color, and the tea juice should be evenly distributed on the leaf surface.

[0048] 6. Second Fixation: The jujube buds, after the second rolling and shaping, undergo a second fixation process. The fixation temperature is 140℃, and the fixation time is 2 minutes. During the fixation process, the buds and leaves are turned moderately to ensure even heating. At the end of the fixation, the color of the buds and leaves is stable, off-flavors are removed, and the tea aroma begins to appear. Measurements show that the moisture content after the second fixation is approximately 45%.

[0049] 7. Low-temperature baking: The jujube buds after the second blanching are baked at a low temperature of 130℃ for 20 minutes. During baking, the buds are turned every 5 minutes to ensure even heating. At the end of baking, the buds feel slightly prickly to the touch and can be clumped together without crumbling. Measurements show that the moisture content after low-temperature baking is approximately 25%.

[0050] 8. Low-Temperature Roasting for Aroma Enhancement: The jujube buds, after low-temperature roasting, are further roasted at 80℃ for 2 hours. During roasting, the buds are turned every 25 minutes to ensure even heating. Roasting continues until the buds are dry, can be easily rubbed into powder, and have a delicate and lasting aroma. After roasting, the finished tea is removed and allowed to cool naturally to room temperature. The moisture content of the finished product is measured to be 5.2%. After cooling, the tea is sifted to remove broken pieces and stored in sealed packaging.

[0051] The jujube bud tea prepared in this embodiment has a natural yellow-green color, tightly rolled and uniform leaves, a light yellow and bright liquor, a fragrant and lasting aroma, a smooth and mellow taste, very mild bitterness and astringency, a distinct sweet aftertaste, and is resistant to multiple infusions. Compared with jujube bud tea produced by conventional single-stage fixation and short-time withering processes, the product of this embodiment has significantly reduced bitterness and astringency, a significantly enhanced and elegant aroma, a clearer liquor, and good quality stability. Testing showed that the finished product has a moisture content of 5.2%, which meets the standards for tea storage and is suitable for long-term preservation.

[0052] Comparative Example 1 uses a conventional process.

[0053] Sour jujube bud tea is prepared using the conventional processing technique (short-time withering + single fixation + single rolling). The specific steps are as follows: 1. Harvesting and Washing: Same as in Example 1. In mid-May of the same year, select 10 kg of fresh, healthy, tender, green, and plump wild jujube buds (2-4 cm in length, with 1-2 unfolded leaves) as raw materials. Place the harvested fresh jujube buds in a washing tank and rinse them repeatedly with running water three times, gently stirring them with your hands each time to ensure the buds and leaves are fully agitated. After washing, remove the buds and leaves and spread them out in a ventilated place to drain the surface moisture until there are no obvious water droplets on the surface of the buds and leaves.

[0054] 2. Spreading (Short Spreading): Spread the washed jujube buds evenly on a bamboo sieve, with a leaf thickness of approximately 5cm. The spreading environment should be a cool, well-ventilated indoor space without direct sunlight, with the temperature controlled at 20-22℃ and the relative humidity at 75%-78%. The spreading time is 2 hours (usually 1-2 hours in conventional processes). Turn the buds lightly every 30 minutes during the spreading process. At the end of spreading, some moisture will have evaporated from the surface of the buds and leaves, and the leaves will be slightly soft.

[0055] 3. Rolling (Single Rolling): Place the withered jujube buds into a tea rolling machine for rolling. The total rolling time is 7 minutes, with the following pressure application: first, roll without pressure for 1.5 minutes, then lightly press for 2 minutes, then lightly press for 2 minutes, and finally lightly press for 1.5 minutes. The rolling machine speed is 45 revolutions per minute. At the end of rolling, the buds and leaves will be initially curled into strips, the cells will be moderately damaged, and a small amount of tea juice will seep out and adhere to the leaf surface.

[0056] 4. Fixation (Single Fixation): The kneaded jujube buds are placed into a drum-type fixation machine for fixation. The fixation temperature is 200℃ (the fixation temperature for regular jujube leaf tea is usually controlled at around 200℃), and the fixation time is 2 minutes and 15 seconds. During the fixation process, the drum rotates continuously to ensure that the buds and leaves are heated evenly. At the end of fixation, the color of the buds and leaves changes from bright green to dark green, the grassy smell dissipates, a ripe aroma is emitted, and the leaf texture softens.

[0057] 5. Baking: Bake the blanched jujube buds. The baking temperature is 130℃, and the baking time is 20 minutes. Turn them over every 5 minutes during the baking process to ensure that the buds and leaves are heated evenly.

[0058] 6. Roasting for Aroma Enhancement: Roast the roasted jujube buds to enhance their aroma. The roasting temperature is 80℃, and the roasting time is 2 hours. During the roasting process, turn the buds every 25 minutes to ensure even heating. Roast until the buds and leaves are dry and can be easily crushed into powder by hand. After roasting, remove the finished tea and let it cool naturally to room temperature. After cooling, sift the tea to remove broken pieces and store it in sealed packaging.

[0059] Sensory evaluation and physicochemical index testing I. Sensory Evaluation Methods Referring to GB / T 23776-2018 "Sensory Evaluation Methods for Tea", an evaluation team composed of 5 professionals with tea evaluation qualifications scored the five factors of appearance, liquor color, aroma, taste and infused leaves (each with a full score of 100 points), and the average score was taken as the final score.

[0060] II. Methods for Testing Physicochemical Indicators ; III. Sensory Evaluation Results ; IV. Results of Detection of Main Physicochemical Components ; V. Comparison of Moisture Content Change Processes ; Note: Comparative Example 1 is a single kneading + single fixation (200℃), without a second kneading and a second fixation process.

[0061] Results Analysis and Conclusions 1. The effect of withering time on bitterness Comparative Example 1 used a conventional 2-hour short withering time, resulting in insufficient transformation of the substances contained in the buds and leaves, and the polyphenolic bitter substances were not fully oxidized and degraded. In contrast, Example 1 used a 22-hour long withering time, which provided sufficient time for the full transformation of bitter substances, reducing the polyphenol content of the finished tea from 22.4% to 18.6%, and significantly reducing the bitterness.

[0062] 2. The effect of two blanching processes on color and aroma Comparative Example 1 used a single fixation (200℃), which did not completely deactivate enzyme activity, leaving some polyphenol oxidase residue that caused slight enzymatic browning during subsequent processing, resulting in a darker color in the finished product. Example 1 used a double fixation (240℃ high-temperature fixation + 140℃ medium-temperature fixation). The first high-temperature fixation rapidly deactivated enzyme activity and prevented browning, while the second medium-temperature fixation further stabilized the color, removed off-flavors, and promoted the conversion of aroma precursors. The finished product's liquor color score (95 points) was 13 points higher than the comparative example (82 points), and its aroma score (94 points) was 16 points higher than the comparative example (78 points).

[0063] 3. The effect of two kneading cycles on shape and foam resistance Comparative Example 1 used a single kneading process, resulting in looser strands and uneven cell damage, leading to uneven flavor extraction during brewing. Example 1 used a double kneading process (first kneading for 6-8 minutes + second kneading for shaping for 5-7 minutes), resulting in tighter and more uniform strands with more thorough and even cell damage. The finished product scored 93 points higher in appearance than the comparative example (85 points), and its water extract content (36.5%) was 3.7 percentage points higher than the comparative example (32.8%), significantly improving its brewing endurance.

[0064] The results of the comparative experiments show that the present invention, through the synergistic effect of long-term withering (20-24 hours), two rounds of fixation (high temperature + medium temperature), two rounds of rolling, and segmented baking to enhance aroma, comprehensively surpasses conventionally processed products in five sensory dimensions: appearance, liquor color, aroma, taste, and infused leaf appearance. The total sensory evaluation score (93.8 points) is 13.8 points higher than that of the conventional process (80.0 points), with a 3.8 percentage point decrease in tea polyphenol content (reduced bitterness), a 1.3 percentage point increase in free amino acid content (enhanced freshness), and a 3.7 percentage point increase in water extract content (enhanced brewing endurance), fully demonstrating the advanced nature and practicality of the present invention's technical solution.

[0065] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A processing method for jujube bud tea, characterized in that, Includes the following steps: S1: Washing the tea: Washing the fresh jujube buds; S2: Withering: After washing the tea, the tea leaves are withered for 20 to 24 hours. S3: First kneading: Kneading time is 6-8 minutes; S4: First high-temperature fixation: temperature 220-260℃, time 2-2.5 minutes; S5: Second kneading and shaping: Kneading time is 5-7 minutes; S6: Second fixation: Temperature is 120-160℃; S7: Low-temperature baking: temperature is 120~140℃; S8: Low-temperature baking for aroma enhancement: temperature is 70-90℃.

2. The method according to claim 1, characterized in that, The spreading of green leaves in step S2 shall be carried out under cool, ventilated conditions without direct sunlight; The spreading of green leaves in step S2 is used to allow the buds and leaves to lose surface moisture and to fully convert the internal substances, thereby reducing the astringent taste.

3. The method according to claim 1, characterized in that, The temperature of the second blanching in step S6 is lower than the temperature of the first high-temperature blanching in step S4; The second blanching step in step S6 is used to further stabilize the color and remove off-flavors.

4. The method according to claim 1, characterized in that, The cleaning described in step S1 is used to remove dust, impurities, and some soluble bitter substances from the surface of fresh jujube buds.

5. The method according to claim 1, characterized in that, The first kneading described in step S3 is used to moderately break down cell tissue in order to facilitate the extraction of flavor during brewing.

6. The method according to claim 1, characterized in that, The first high-temperature blanching in step S4 is used to quickly deactivate oxidase activity, prevent browning of buds and leaves, and remove the green odor.

7. The method according to claim 1, characterized in that, The second kneading and shaping in step S5 is used to make the bud and leaf strips firm.

8. The method according to claim 1, characterized in that, The low-temperature baking described in step S7 is used to reduce moisture and preliminarily set the shape.

9. The method according to claim 1, characterized in that, The low-temperature baking process described in step S8 is used to enhance the aroma and ensure that the finished product has a suitable moisture content.

10. A type of jujube bud tea, characterized in that, Prepared by the method described in any one of claims 1 to 9.

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