Method for improving quality of special tea leaves for beverage, tea leaves obtained by using method and tea leaf beverage

Abstract

The invention discloses a method for improving the quality of special tea leaves for beverages and a tea leaf beverage obtained by using the method. The method comprises the following steps: spreading fresh tea leaves, deactivating enzymes, spreading for cooling, rolling, deblocking and drying, wherein vibration treatment is carried out before spreading or during spreading, and the conditions of vibration treatment are as follows: the vertical amplitude is not less than 1 cm or the reciprocating amplitude is not less than 5 cm, and the vibration duration is 20-60 s; the number of times of vibration treatment is at least one. After the method is applied, the soup color, aroma and taste of the special tea leaves for the beverage can be improved; and the phenol-ammonia ratio (such as green tea phenol-ammonia) of the obtained tea leaves is reduced by more than 4%, and the content of main aroma components is increased by more than 10%.

Description

Technical Field

[0001] This application relates to the field of tea processing technology, specifically to methods for improving the quality of beverage-grade tea leaves and the tea leaves and tea beverages obtained therefrom, and further to methods for improving the intrinsic quality of beverage-grade tea leaves by using short-term vibration stimulation of detached fresh leaves before or during the spreading process. Background Technology

[0002] The quality of tea encompasses factors such as the appearance of the dry leaves, the color of the tea liquor, the aroma, the taste, and the infused leaves. Among these, the color of the liquor, the aroma, and the taste are collectively referred to as intrinsic quality or internal characteristics. Numerous studies have shown that tea quality primarily depends on the tea variety, cultivation conditions, and processing techniques. The variety and cultivation conditions determine the quality of the fresh leaves, while scientifically sound processing techniques not only determine the type of tea product but also maximize the quality potential of the fresh leaves.

[0003] Taking green tea as an example, it is one of the six major tea categories in my country, ranking first in both output and value. Within the green tea category, there are numerous varieties of green tea products. Based on appearance, they can be categorized as flat, curled, granular, and straight-strip green tea. Based on processing methods, they can be divided into steamed, pan-fried, oven-dried, and sun-dried green tea. Based on season, they can be categorized as spring, summer, and autumn green tea. Based on quality, they can be divided into premium green tea and bulk green tea. Based on consumption methods, they can be divided into beverage-grade green tea, tea-specific green tea, and tea-food-specific green tea. Although there are many varieties of green tea products, they all share similar main processing steps, including withering, fixation, rolling, and drying. Spreading, also known as withering, refers to placing freshly harvested leaves on bamboo sieves, bamboo mats, withering troughs, or withering machines for a period of time to allow the detached fresh leaves to lose a small amount of moisture and release grassy odor. Spreading to a certain extent causes the tea leaves to lose some moisture, which on the one hand softens the leaves and makes them easier to fix in the subsequent process, and on the other hand, the process of losing moisture stimulates the activity of enzymes in the leaf cells, providing a foundation for the formation of subsequent flavor and quality.

[0004] Numerous studies and production practices have shown that planting suitable green tea varieties, selecting appropriate harvesting tenderness, adopting suitable fertilization and pruning measures, and utilizing appropriate processing parameters can all improve the quality of green tea to a certain extent. For example, green tea processed from fresh leaves of varieties that sprout early in spring and have a low phenol-to-amino acid ratio typically has a fresher and better quality tea liquor; green tea processed from one bud and one to two leaves has a richer aroma and flavor than green tea processed from one bud and three or four leaves; and green tea processed from fresh leaves harvested in tea gardens with sufficient organic base fertilizer in autumn and winter and timely application of fast-acting nitrogen fertilizer during the production season usually has a higher aroma and a more mellow and fresh taste compared to green tea processed from tea leaves with inadequate application of base fertilizer and top dressing. Furthermore, green tea processed from the same fresh leaves using different processing parameters will also have significant differences in quality. For example, the time for spreading the fresh leaves, the method of fixing, the rolling parameters, and the drying temperature all have a significant impact on the quality of green tea. While these methods and measures have some effect on improving the quality of green tea, especially for beverage-grade green tea with better tenderness, the above methods and measures often fail to achieve satisfactory results because the raw materials for beverage-grade green tea generally have lower tenderness. Summary of the Invention

[0005] Based on this, this application provides at least one method for improving the quality of tea leaves specifically for beverages, and the tea leaves and tea beverages obtained using the method.

[0006] In a first aspect of this application, a method for improving the quality of tea leaves specifically for beverages is provided, comprising:

[0007] The fresh tea leaves are processed as follows: spreading, fixing, cooling, rolling, breaking up clumps and drying;

[0008] Among them, vibration treatment is carried out before or during the laying process. The conditions for vibration treatment include: vertical amplitude of not less than 1 cm or reciprocating amplitude of not less than 5 cm, and vibration duration of 20 s to 60 s; vibration treatment is carried out at least once.

[0009] In a second aspect of this application, tea prepared using a method for improving the quality of beverage-specific tea as described in the first aspect is provided.

[0010] In a third aspect of this application, a tea beverage is provided, which is prepared using tea as described in the second aspect.

[0011] After applying the above method, the color, aroma and taste of beverage-grade tea (such as green tea) can be improved; moreover, the phenol-amino acid ratio of the tea (such as green tea phenol-amino acid) is significantly reduced (e.g., reduced by more than 4%), and the content of the main aroma components is significantly increased (e.g., increased by more than 10%); sensory evaluation shows a distinct fresh and delicate floral aroma, and the content of 13 key volatile substances was detected, which is different from traditional green tea and oolong tea, creating a new fresh and delicate floral aroma. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments and examples of this application, and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments or examples will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. Those skilled in the art can obtain other drawings based on these drawings without creative effort. It should also be noted that the drawings are all drawn in a simplified form and are only used to conveniently and clearly assist in illustrating this application.

[0013] Figure 1 This is a bar chart showing the comparison of the phenol-to-ammonia ratio (A1) and the content of major aroma substances (A2) of 'Longjing 43' green tea processed by conventional processes and this method in one embodiment of this application.

[0014] Figure 2 This is a bar chart showing the comparison of the catechin-to-amine ratio (B1) and the content of major aroma substances (B2) of 'Fuding Da Bai Cha' processed by conventional technology and this method in one embodiment of this application.

[0015] Figure 3 This is a bar chart showing the comparison of the phenol-to-ammonia ratio (C1) and the content of major aroma substances (C2) of 'Jin Guan Yin' green tea processed by conventional processes and this method in one embodiment of this application.

[0016] Figure 4 This is a bar chart showing the comparison of the phenol-to-ammonia ratio (D1) and the content of major aroma substances (D2) of 'Phoenix Narcissus' green tea processed by conventional processes and this method in one embodiment of this application.

[0017] Figure 5 This is a bar chart showing the comparison of the main volatile substances in green tea produced by three different processing methods for autumn-processed Golden Guanyin fresh leaves according to one embodiment of this application. Detailed Implementation

[0018] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] In this application, unless otherwise specified, "one or more" means any one of the listed items or any combination of the listed items. Similarly, "one or more" and other instances that otherwise indicate "one or more" shall be understood in the same way unless otherwise specified.

[0021] The terms “combinations thereof,” “any combination thereof,” and “any combination thereof” as used in this application include all suitable combinations of any two or more of the listed items.

[0022] In this application, the word "suitable" in "suitable combination", "suitable method", "any suitable method" etc., shall be defined as being able to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0023] In this application, terms such as "further," "even more," "particularly," "for example," "like," "example," and "exemplary" are used for descriptive purposes to indicate that different technical solutions preceding and following each other are related in terms of their coverage, but should not be construed as limiting the preceding technical solution or restricting the scope of protection of this application. In this application, unless otherwise specified, A (e.g., B) indicates that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0024] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it refers to either "with" or "without" a parallel solution. If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. Unless otherwise specified, the descriptions such as "optionally include" and "optionally contain" in this application, taking "optionally include" as an example, mean "may include or not include."

[0025] The terms “containing,” “comprising,” and “including” as used in this application are synonyms and are inclusive or open-ended, not excluding additional, uncited members or features. Members or features include, for example, materials or components, structures, elements, instruments, etc.; non-limiting examples of members or features include actions, conditions under which actions occur, timing, states, etc.

[0026] In this application, the technical features or solutions described in open-ended language include both closed-ended technical features or solutions consisting of the listed contents and open-ended technical features or solutions that include the listed contents.

[0027] In this application, the exemplary descriptions such as "in some implementations (or embodiments)" and "in one implementation (or embodiment)" may cover, but are not limited to, the following meanings: these solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0028] In this application, the terms "first aspect," "second aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first aspect," "second aspect," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0029] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0030] In this application, where the method flow involves multiple steps, unless otherwise explicitly stated herein, there is no strict order restriction on the execution of these steps; they can be executed in any order other than those described. Moreover, any step may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or simultaneously with other steps or parts of the sub-steps or stages of other steps.

[0031] After proper spreading, the leaves are rapidly turned or briefly vibrated to stimulate them, causing the aromatic substances (fatty derivatives, terpene derivatives, aromatic derivatives, nitrogen-oxygen heterocyclic compounds, etc.) and amino acids and sugars in the fresh leaves to undergo biochemical transformations such as glycoamine reactions under the action of biological enzymes, forming floral aromatic substances. A series of material transformations increase the content of floral aromatic substances such as indole, trans / ci--linalool oxide, linalool, dihydrolinalool, tea pyrrole, trans-β-ionone, and nerolidol. However, for tea leaves, such as green tea, higher levels of these floral aromatic substances are not necessarily better. Many of these compounds exhibit the floral aroma of tea even at low concentrations. Some high concentrations of non-floral volatile substances will increase the concentration of these compounds. The interaction of these volatile components alters the aroma of the processed tea, affecting its overall aroma and resulting in the floral characteristics of oolong tea. Therefore, how to control the proper volatilization of these aromatic substances to jointly form a unique new type of refreshing floral fragrance and create a new tea aroma is a technical problem that urgently needs to be solved.

[0032] The inventors unexpectedly discovered that stimulating detached fresh leaves with short-term vibration or rapid turning during the spreading process can create a novel, refreshing floral aroma and improve the overall quality of beverage-grade tea. This method has advantages such as simple operation, wide applicability, good controllability, and significant effects.

[0033] This method mainly involves spreading out fresh leaves, primarily one bud and three leaves, that meet the tenderness requirements for beverage-grade tea at an appropriate time. During the spreading process, the fresh leaves are placed in a vibrating screen or a circular vibrating screen and subjected to short-term vibration stimulation for 20-60 seconds, requiring an up-and-down amplitude of no less than 1 cm or a reciprocating amplitude of no less than 5 cm. Then, the fresh leaves are spread out or stored in the conventional manner. After the leaves have been spread out to the appropriate degree, they are processed into tea according to the conventional pan-frying process.

[0034] One aspect of this application provides a method for improving the quality of tea leaves specifically for beverages, comprising:

[0035] The fresh tea leaves are processed as follows: spreading, fixing, cooling, rolling, breaking up clumps and drying;

[0036] Among them, vibration treatment is carried out before or during the laying process. The conditions for vibration treatment include: vertical amplitude of not less than 1 cm or reciprocating amplitude of not less than 5 cm, and vibration duration of 20 s to 60 s; vibration treatment is carried out at least once.

[0037] Unless otherwise specified, the term "tea" in this application may cover green tea, black tea, white tea, dark tea, oolong tea, etc., for example, green tea.

[0038] In this application, the "amplitude" in the above method theoretically has no upper limit. However, based on tea processing equipment, the reciprocating amplitude and vertical amplitude should not exceed 120 cm. The inventors tried to use different reciprocating amplitudes (5 cm, 20 cm, 60 cm and 100 cm respectively) and different vertical amplitudes (1 cm, 5 cm and 10 cm), and found that as long as the vertical amplitude is not less than 1 cm or the reciprocating amplitude is not less than 5 cm, the expected effect can be achieved.

[0039] In some embodiments, the spreading time can be 10 h to 16 h, for example, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, or any value or range between two values. In some embodiments, the spreading time is 10 h to 14 h.

[0040] In some implementations, the thickness of the spread layer does not exceed 4 cm.

[0041] In some implementations, the vibration treatment can be performed before or during the laying process. Examples include: laying for 12 hours with vibration every 4 hours; vibrating first, then laying for 12 hours; vibrating after laying for 4 hours, then laying for another 12 hours; vibrating after laying for 8 hours, then laying for another 4 hours, etc.

[0042] While not wanting to be limited by any theory, it is believed that in a 10-14 hour withering process, simply adding vibration 4 hours or more before the end of withering allows the tea leaves sufficient time to metabolize the metabolic products generated by vibration, thus enabling the tea to acquire floral flavor while maintaining the characteristic green color of the dry tea, tea liquor, and tea leaves. For example, within the specified withering time (e.g., 10-14 hours), if vibration is added earlier (e.g., vibrating directly followed by withering for 10-14 hours), providing a longer metabolic transformation time, floral-scented tea can still be produced.

[0043] In short, the short-term vibration stimulation described in the above method can be performed at any time from before the start of the fresh leaf spreading to 4 hours before the end of spreading (taking a total spreading time of 10 hours as an example, the short-term vibration stimulation period is any time between before the start of spreading and the 6th hour of spreading). Preferably, performing short-term vibration stimulation before the start of spreading results in the greatest improvement in internal quality and stable effect. It is also easier to connect with upstream and downstream processes and is applicable to all tea tree varieties.

[0044] In some embodiments, the blanching is performed at high temperature. For example, the temperature used is 220℃~250℃; such as 220℃, 225℃, 230℃, 235℃, 240℃, 245℃, 250℃, or any range or value between two values.

[0045] In some implementations, a 60-type drum blanching machine is used for blanching.

[0046] In some embodiments, the kneading conditions include kneading for 30 to 60 minutes according to the principle of light-heavy-light pressure; for example, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, or any range or value between two values.

[0047] In some implementations, a 55-type kneading machine is used for kneading.

[0048] In some embodiments, the drying process includes three stages:

[0049] The process involves initial drying over a low flame, stir-frying until dry, shaping, and final drying to enhance aroma.

[0050] In some embodiments, the conditions for initial drying of the raw material include:

[0051] 10 min~15 min of rough fire at 120℃~140℃.

[0052] In some embodiments, the initial drying temperature is 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C, 130°C, 131°C, 132°C, 133°C, 134°C, 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, or any range or value between two such values.

[0053] In some embodiments, the initial drying time is 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, or any range or value between two values.

[0054] In this application, conventional equipment in the field can be used for initial drying, such as a chain plate dryer.

[0055] In some embodiments, the moisture content of the tea leaves after initial drying is 40 wt% to 50 wt%; for example, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, etc.

[0056] In some embodiments, the conditions for stir-frying and shaping include:

[0057] After the initial drying of the tea leaves is carried out at 90℃~130℃, the moisture content is 15 wt%~25 wt%, and then the leaves are cooled and rehydrated at room temperature for 0.5 h~6 h.

[0058] In some implementations, the drying and shaping temperature is 90°C, 100°C, 110°C, 120°C, 130°C, or any value or range between two of these values.

[0059] In some implementations, the time for room temperature cooling and rehumidification is 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, or any value or range between two values.

[0060] Unless otherwise specified, the term "room temperature" in this application is a term well known to those skilled in the art, also known as normal temperature or general temperature, and is generally defined as 23℃±2℃, 25℃±5℃ or 20℃±5℃, for example, but not limited to about 15℃ to 18℃, about 24℃ to 26℃, about 22℃ to 25℃ or about 27℃ to 30℃, which may vary slightly depending on the season and global extreme climate factors, such as having a temperature range of 30℃±5℃.

[0061] In this application, conventional equipment in the art can be used for stir-frying and shaping, such as a double-pan stir-frying dryer.

[0062] In some embodiments, the conditions for the full-drying and aroma extraction include:

[0063] The dried and shaped tea leaves are stir-fried at 75℃~85℃ until the moisture content is no more than 6.5 wt%.

[0064] In some embodiments, the temperature for fully drying and extracting aroma is 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, or any range or value between two of these values.

[0065] In some implementations, a chain plate dryer or an octagonal drum dryer is used for thorough drying and aroma enhancement.

[0066] In some embodiments, the vibration treatment is performed on a circular vibrating screen and / or a linear vibrating screen; the screen mesh size of the circular vibrating screen or the linear vibrating screen is, for example, 40 to 60 mesh.

[0067] In some embodiments, the mass percentage of one bud and three leaves in the fresh tea leaves is 45 wt% to 60 wt%.

[0068] In some embodiments, the fresh tea leaves may also include one or more of the following: one bud with two leaves, one bud with four leaves, and a single leaf.

[0069] In some embodiments, the fresh tea leaves may also include one bud and two leaves, one bud and four leaves, and a single leaf.

[0070] In some embodiments, the one bud and two leaves account for 15 wt% to 25 wt% of the mass of the fresh tea leaves; for example, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, or any range or value between two values.

[0071] In some embodiments, the mass percentage of the one bud and four leaves in the fresh tea leaves is 20 wt% to 25 wt%; for example, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, or any range or value between two values.

[0072] In some embodiments, the weight percentage of the single leaf in the fresh tea leaves is 5 wt% to 15 wt%; for example, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, or any range or value between two values.

[0073] Another aspect of this application provides tea obtained using the method described above for improving the quality of beverage-specific tea.

[0074] Another aspect of this application provides a tea beverage prepared using tea leaves as described above.

[0075] In some embodiments, the tea leaves are green tea.

[0076] After applying the method described above, the color, aroma, and taste of beverage-grade green tea can be improved by 0-3 points, 1-2 points, and 0-2 points respectively, and the total score of the three intrinsic qualities can be improved by more than 2.5 points. Moreover, the phenol-ammonia ratio of green tea processed by this method is reduced by more than 4%, and the content of the main aroma components is increased by more than 10%. The sensory evaluation shows a distinct fresh and delicate floral aroma, and the content of 13 key volatile substances is detected at the same time. This is different from traditional green tea and oolong tea, creating a new fresh and delicate floral aroma.

[0077] The following are some examples.

[0078] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where conditions are not specified, reference should be made to the guidelines given in this application, or to experimental manuals or conventional conditions in the art, or to the conditions recommended by the manufacturer, or to experimental methods known in the art.

[0079] According to the harvesting standards for beverage-grade green tea, fresh leaves, mainly one bud and three leaves, are harvested during the production season. The total withering time for the harvested fresh leaves is 12±2 hours. From the beginning of withering to 4 hours before the end, the fresh leaves are placed in a linear vibrating screen or circular vibrating screen equipped with a 40-60 mesh sieve for one vibration treatment. The vertical amplitude should be no less than 1 cm or the reciprocating amplitude no less than 5 cm, for 20-60 seconds. After vibration treatment, the fresh leaves are withered using conventional methods. After withering, the leaves are processed into green tea according to conventional processes such as fixation, rolling, and drying.

[0080] The beverage-grade green tea processed using this method has improved color, aroma, and taste by 0-3 points, 1-2 points, and 0-2 points respectively compared to conventionally processed green tea without vibration treatment, with a total improvement of more than 2.5 points in the three internal qualities. Moreover, the phenol-ammonia ratio of green tea processed using this method decreases by more than 4%, and the content of major aroma components increases by more than 10%.

[0081] Example 1

[0082] In the later stages of spring tea, fresh leaves, mainly one bud and three leaves, are harvested from the 'Longjing 43' tea garden. The mechanical composition of the fresh leaves is 50% one bud and three leaves, 20% one bud and two leaves, 25% one bud and four leaves, and 5% single leaves. Fresh leaves are transferred to a 60-mesh linear vibrating screen with an amplitude of 1.5cm for 30 seconds. They are then transferred to a spreading rack or storage trough, with a spreading thickness not exceeding 3cm. After spreading for 14 hours, a 60-type drum fixation machine is used at 220-250℃ for fixation. After cooling to room temperature, the leaves are transferred to a 55-type rolling machine and rolled for 30-60 minutes using a light-heavy-light-pressurization principle. After the rolled leaves are broken up by a de-clumping machine, they are dried in a chain-plate dryer at 120-140℃ for 10-15 minutes until the moisture content is approximately 45%. Then, they are transferred to a double-pan roasting dryer at 130℃ until the moisture content is approximately 20%. The leaves are then cooled and rehydrated at room temperature for 1 hour, and then transferred to an octagonal drum roasting dryer at 80±5℃ until fully dry. The finished green tea has a moisture content of less than 6.5%. Meanwhile, the conventional method was used to process control green tea, meaning that all process parameters were the same as described above, except for vibration treatment.

[0083] According to the "Sensory Evaluation Methods for Tea" (GB / T 23776-2018), green tea processed using conventional methods and green tea processed using this method were brewed, and the three factors of liquor color, aroma, and taste were evaluated. The results are shown in Table 1. The liquor color and aroma scores of the green tea processed using this method were 3 and 2 points higher, respectively, than those processed using conventional methods, while the taste scores were the same. The total score of the green tea processed using this method was 5 points higher than that processed using conventional methods. Colorimetric analysis showed that the phenolic amino acid content of the green tea processed using this method decreased by 5.2% compared to the conventional process. GC-MS analysis showed that the content of linalool and linalool oxides, the main aroma substances, in the green tea processed using this method was 12.9% higher than that processed using conventional methods (see Table 1). Figure 1 ).

[0084] Table 1. Effects of short-term vibration on the quality improvement of beverage-grade green tea made from fresh 'Longjing 43' leaves in spring.

[0085]

[0086] Note: Conventional process refers to green tea produced by conventional withering, fixation, rolling and drying processes; new process refers to green tea produced by vibrating for 30 seconds before withering, followed by conventional withering, fixation, rolling and drying processes.

[0087] Example 2

[0088] In summer, fresh leaves, primarily one bud and three leaves, are harvested from tea gardens of the 'Fuding Da Bai Cha' variety. The mechanical composition of the fresh leaves is as follows: one bud and three leaves account for 45%, one bud and two leaves for 25%, one bud and four leaves for 25%, and single leaves for 15%. The harvested fresh leaves are placed on withering racks or withering troughs, with a thickness not exceeding 4cm. After withering for 4 hours, they are transferred to a 40-mesh circular vibrating screen with a reciprocating amplitude of 10cm for 20 seconds. After this, they are transferred back to withering racks or withering troughs, with a thickness not exceeding 4cm. After another 6 hours of withering, a 60-type drum withering machine is used for withering at 220-250℃. After cooling to room temperature, the withered leaves are transferred to a 55-type rolling machine and rolled according to… The leaves are kneaded for 30-60 minutes using a light-heavy-light pressure principle. After being broken up by a de-clumping machine, they are then subjected to initial heating at 120-140℃ for 10-15 minutes in a chain plate dryer until the moisture content reaches approximately 45%. They are then transferred to a double-pan roasting dryer and roasted at 130℃ until the moisture content reaches approximately 20%. The tea is then removed, cooled at room temperature, and rehydrated for 1 hour before being transferred back to the chain plate dryer and dried completely at 80±5℃. The finished green tea has a moisture content of less than 6.5%. Simultaneously, a control green tea is processed using conventional methods, with all process parameters identical except for vibration treatment.

[0089] According to the "Sensory Evaluation Methods for Tea" (GB / T 23776-2018), green tea processed using conventional methods and green tea processed using this method were brewed, and the three factors of liquor color, aroma, and taste were evaluated. The results are shown in Table 2. The green tea processed using this method scored 1 point higher in liquor color, 1 point higher in aroma, and 2 points higher in taste than that processed using conventional methods. The total score of green tea processed using this method was 4 points higher than that processed using conventional methods. Colorimetric analysis showed that the phenolic amino acid content of green tea processed using this method decreased by 4.0% compared with that processed using conventional methods. GC-MS analysis showed that the content of linalool and linalool oxides, the main aroma substances, in green tea processed using this method was 24.7% higher than that processed using conventional methods (see Table 2). Figure 2 ).

[0090] Table 2. Effects of short-term vibration on the quality improvement of beverage-grade green tea made from fresh leaves of 'Fuding Da Bai Cha' in summer.

[0091]

[0092] Example 3

[0093] In autumn, fresh leaves, primarily one bud and three leaves, are harvested from 'Jin Guanyin' tea gardens. The mechanical composition of the fresh leaves is as follows: one bud and three leaves account for 50%, one bud and two leaves for 15%, one bud and four leaves for 25%, and single leaves for 10%. The harvested fresh leaves are placed on withering racks or withering troughs, with a thickness not exceeding 4cm. After withering for 8 hours, they are transferred to a 60-mesh linear vibrating screen with a vertical amplitude of 1.5cm for 45 seconds. Afterward, they are transferred back to withering racks or withering troughs, with a thickness not exceeding 4cm. After another 4 hours of withering, a 60-type drum withering machine is used for withering at 220-250℃. After cooling to room temperature, the withered leaves are transferred to a 55-type rolling machine and rolled according to… The leaves are kneaded for 30-60 minutes using a light-heavy-light pressure principle. After being broken up by a de-clumping machine, they are dried in a chain-plate dryer at 120-140℃ for 10-15 minutes until the moisture content is about 45%. Then, they are transferred to a double-pan roasting dryer and roasted at 130℃ until the moisture content of the finished product is about 20%. After being cooled and rehydrated at room temperature for 1 hour, they are transferred to an octagonal drum roasting dryer and roasted at 80±5℃ until fully dry. The moisture content of the finished green tea is less than 6.5%. At the same time, a control green tea is processed using conventional methods, that is, all process parameters are the same except for vibration treatment.

[0094] According to the "Sensory Evaluation Methods for Tea" (GB / T 23776-2018), green tea processed using conventional methods and green tea processed using this method were brewed, and the three factors of liquor color, aroma, and taste were evaluated. The results are shown in Table 3. The aroma and taste scores of the green tea processed using this method were 2 points and 0.5 points higher, respectively, than those processed using conventional methods. The liquor color scores were the same for both methods, and the total score of the green tea processed using this method was 2.5 points higher than that processed using conventional methods. Colorimetric analysis showed that the phenolic amino acid content of the green tea processed using this method was 14.1% lower than that processed using conventional methods. GC-MS analysis showed that the content of major aroma substances such as dihydrolinalool in the green tea processed using this method was 19.8% higher than that processed using conventional methods (see Table 3). Figure 3 ).

[0095] Table 3. Effects of short-term vibration on the quality improvement of beverage-grade green tea made from autumn-harvested fresh leaves of Golden Guanyin.

[0096]

[0097] Example 4

[0098] In autumn, fresh leaves, mainly one bud and three leaves, are harvested from the 'Phoenix Narcissus' tea garden. The mechanical composition of the fresh leaves is 60% one bud and three leaves, 15% one bud and two leaves, 20% one bud and four leaves, and 5% single leaves. The harvested fresh leaves are transferred to a 40-mesh circular vibrating screen with a reciprocating amplitude of 10cm for 60 seconds. After this, they are transferred to a spreading rack or storage trough, with a spreading thickness not exceeding 4cm. After spreading for another 12 hours, a 60-type drum fixation machine is used to fix the leaves at 220-250℃. After cooling, the leaves are transferred to a 55-type rolling machine and rolled for 30-60 minutes according to the principle of light-heavy-light pressure. After the rolled leaves are broken up by a de-clumping machine, they are dried in a chain plate dryer at 120-140℃ for 10-15 minutes until the moisture content is about 45%. Then, they are transferred to a double-pan roasting dryer and roasted at 130℃ until the moisture content of the finished product is about 20%. After cooling and rehydration at room temperature for 1 hour, they are transferred to an octagonal drum roasting dryer and roasted at 80±5℃ until fully dry. The finished green tea has a moisture content of less than 6.5%. Meanwhile, the same green tea was processed using conventional methods, meaning that all process parameters were identical except for vibration treatment.

[0099] According to the "Sensory Evaluation Methods for Tea" (GB / T 23776-2018), green tea processed using conventional methods and green tea processed using this method were brewed, and the three factors of liquor color, aroma, and taste were evaluated. The results are shown in Table 4. The green tea processed using this method scored 1 point higher in liquor color, 2 points higher in aroma, and 1 point higher in taste than that processed using conventional methods. The total score of green tea processed using this method was 4 points higher than that processed using conventional methods. Colorimetric analysis showed that the phenolic amino acid content of green tea processed using this method decreased by 6.1% compared with that processed using conventional methods. GC-MS analysis showed that the content of major aroma substances such as linalool and dihydrolinalool in green tea processed using this method was 42.4% higher than that processed using conventional methods (see Table 4). Figure 4 ).

[0100] Table 4. Effects of short-term vibration on the quality improvement of beverage-grade green tea made from fresh autumn Phoenix Narcissus leaves.

[0101]

[0102] Comparative Example 1

[0103] Select fresh tea leaves of "Golden Guanyin" variety, consisting of one bud and three or four leaves, as raw materials. Process them according to the following steps: ① Place the leaves on a spreading rack or storage trough, with a thickness not exceeding 4cm. Use a linear vibrating screen with an amplitude of 6mm for 8 minutes. Transfer the leaves to a spreading rack or storage trough, and repeat this process for 8 minutes every 1-3 hours, for a total of 3-5 times. ② Process the vibrated tea leaves according to the conventional green tea processing techniques: spreading, fixing, rolling, and drying, to produce finished green tea A.

[0104] Using the same batch of fresh tea leaves, floral-scented green tea B was produced using the process described in Example 3. Simultaneously, using the same batch of fresh tea leaves, a control green tea was processed using conventional methods, omitting step ① above, while keeping all other process parameters the same, to produce conventionally processed green tea C.

[0105] According to the "Sensory Evaluation Methods for Tea" (GB / T 23776-2018), green tea A (comparative example 1), floral green tea B, and conventionally processed green tea C were brewed, and the three factors of liquor color, aroma, and taste were evaluated. The results are shown in Table 5. The aroma score of floral green tea B was 1 point higher than that of green tea A (comparative example 1), while the taste scores were the same. Overall, A was 0.5 points lower than B. However, in terms of flavor, the floral aroma of A and B is inconsistent. B has a light and refreshing floral aroma, while A exhibits the typical floral characteristics of light-roasted oolong tea. Moreover, although the taste scores are the same, A has a strong astringent taste, which is a distinct oolong tea flavor characteristic, and A can be classified as oolong tea. Colorimetric analysis showed that B had phenolic and amino acid content that was 26.7% lower than A and 14.1% lower than C. GC-MS analysis showed that the content of the main aroma substances in the three teas showed significant differences. Figure 5 Consistent with the sensory evaluation results, the increase in volatile substances in sample B to a certain extent constitutes the unique fresh floral fragrance, while the excessive content of volatile substances such as linalool, geraniol, and indole in sample A exhibits the aroma characteristics of oolong tea.

[0106] Table 5. Comparative Evaluation of the Quality of Green Tea Processed from Three Processes Using Fresh Leaves of Autumn Golden Guanyin

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A method of improving the quality of tea leaves dedicated for beverages, characterized by, It comprises: The tea fresh leaves are treated as follows: spreading, fixation, spreading cooling, rolling, unblocking and drying; Wherein, the vibration treatment is performed before or during the spreading, and the vibration treatment conditions include: the up-down amplitude is not less than 1 cm or the reciprocating amplitude is not less than 5 cm, and the vibration time is 20 s~60 s; the vibration treatment is performed at least once.

2. The method of improving the quality of tea leaves for a specialty tea beverage according to claim 1, wherein, The spreading conditions include: the thickness is not more than 4 cm, and the time is 10 h~14 h; Optionally, when the vibration treatment is performed during the spreading, the tea leaves are spread for at least 4 h after the vibration treatment.

3. The method of improving the quality of tea leaves for a specialty tea beverage according to claim 1, wherein The fixation temperature is 220℃~250℃; Optionally, the fixation is performed by using a 60-type rolling fixation machine.

4. The method of improving the quality of tea leaves for a specialty tea beverage according to claim 1, wherein The rolling conditions include: rolling for 30 min~60 min according to the light-heavy-light pressure principle; Optionally, the rolling is performed by using a 55-type rolling machine.

5. The method of improving the quality of tea leaves for a specialty tea beverage according to claim 1, wherein The drying includes three stages: Primary drying, drying and shaping, and sufficient drying and aroma enhancement; Optionally, the drying meets one or more of the following conditions: (1) The primary drying conditions include: Primary drying for 10 min~15 min at 120℃~140℃; Optionally, the primary drying is performed by using a chain plate dryer; Optionally, the water content of the tea leaves after the primary drying is 40 wt%~50 wt%; (2) The drying and shaping conditions include: After the primary drying, the tea leaves are dried to a water content of 15 wt%~25 wt% at 90℃~130℃, and then cooled at room temperature and humidified for 0.5 h~6 h; Optionally, the drying and shaping is performed by using a double-pot drying machine; (3) The sufficient drying and aroma enhancement conditions include: The tea leaves obtained by the drying and shaping are dried to a water content of not more than 6.5 wt% at 75℃~85℃; Optionally, the sufficient drying and aroma enhancement is performed by using a chain plate dryer or an octagonal drum dryer.

6. The method of improving the quality of tea leaves for a specialty tea beverage according to any one of claims 1 to 5, wherein The vibration treatment is performed on a circular vibration screen and / or a linear vibration screen with a mesh size of 40 mesh~60 mesh.

7. The method of improving the quality of tea leaves for a specialty tea beverage according to any one of claims 1 to 5, wherein The mass ratio of one-bud-three-leaves in the tea fresh leaves is 45 wt%~60 wt%.

8. The method of improving the quality of tea leaves for a specialty tea beverage according to claim 7, wherein The tea fresh leaves further comprise one or more of one-bud-two-leaves, one-bud-four-leaves and single leaves; Optionally, the mass ratio of the one-bud-two-leaves is 15 wt%~25 wt%, the mass ratio of the one-bud-four-leaves is 20 wt%~25 wt%, and the mass ratio of the single leaves is 5 wt%~15 wt%.

9. Tea obtained by using the method for improving the quality of beverage special tea leaves according to any one of claims 1~8.

10. A tea leaf beverage, characterized by, It is prepared by using the tea according to claim 9.

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