Method for producing organic large-leaf black tea

Abstract

This invention provides a method for producing organic large-leaf black tea, comprising the following steps: S1, picking fresh leaves from large-leaf tea trees, spreading them evenly in a withering trough, and subjecting them to alternating strong and weak wind speeds to obtain withered tea leaves; S2, placing the withered tea leaves in a shaking machine for shaking, then removing and kneading to obtain kneaded tea leaves; S3, spreading the kneaded tea leaves obtained in S2 to a depth of 6-8 cm, subjecting the spread kneaded tea leaves to mist steaming, then placing them in a fermentation chamber for fermentation and baking to obtain organic large-leaf black tea. This invention, through specific processes, can promote the full oxidation and transformation of polyphenols and other internal substances in large-leaf tea during processing, while also better preserving the effective components in black tea, synergizing the flavor and aroma of black tea to form a rich, full-bodied, deep red tea soup with a strong and lasting floral aroma, effectively enhancing the aroma and quality of large-leaf black tea.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, and in particular to a method for producing organic large-leaf black tea. Background Technology

[0002] Hainan is a newly emerging tea-producing region in my country, with a long history of large-scale tea cultivation and a long-standing tea-drinking tradition. Tea is made from the tender shoots of tea trees through processing. The production process of black tea typically involves key steps such as withering, rolling, fermentation, and drying of fresh leaves. Black tea is widely popular among consumers due to its unique qualities, including its high aroma, vibrant color, and rich flavor. Large-leaf black tea is made from the large-leaf variety of tea trees grown in Hainan. This variety has large, thin leaves and relatively high levels of phenolic compounds, making it an ideal variety for producing high-quality black tea. However, currently, the processing techniques used in producing black tea from large-leaf tea trees are relatively underdeveloped, resulting in inconsistent quality, unbalanced flavor and aroma, and a loss of the original taste. Furthermore, the processing also leads to significant losses of the tea's beneficial components, severely hindering the healthy development of the local black tea industry. Summary of the Invention

[0003] In view of this, the present invention proposes a method for producing organic large-leaf black tea. The method of the present invention can better preserve the effective components in black tea, while also harmonizing the taste and aroma of black tea, and can effectively improve the quality of large-leaf black tea.

[0004] The technical solution of this invention is implemented as follows:

[0005] A method for producing organic large-leaf black tea includes the following steps:

[0006] S1. Fresh leaves from large-leaf tea trees (one bud and two leaves, one bud and three leaves, or one bud and four leaves) are picked and evenly spread 4-6 cm into a withering trough. Alternating between strong and weak wind speeds are then applied to obtain withered tea leaves. The withering temperature is 25-30℃, and the alternating strong and weak wind speed process is as follows: first, the wind speed is 0.4-0.6 cm / s. 3 Blow air at a speed of 1.2-1.6 cm / s for 12-15 minutes, let it stand for 1-2 minutes, and then blow air at a speed of 1.2-1.6 cm / s again. 3 Blow air at / s for 12-15 minutes, let stand for 1-2 minutes, and repeat blowing 3-4 times;

[0007] S2. Place the withered tea leaves in a shaking machine for shaking, then take them out and knead them to obtain kneaded tea leaves;

[0008] S3. Spread the rolled tea leaves obtained in S2 to a depth of 6-8 cm, steam the spread rolled tea leaves with mist, and then place them in a fermentation room for fermentation and baking to obtain organic large-leaf black tea.

[0009] Furthermore, in step S2, the shaking process is carried out for 3 to 5 minutes at a temperature of 25 to 30°C and a rotation speed of 60 to 80 r / min.

[0010] Furthermore, in step S2, the kneading process is as follows: first at 0.5–0.8 kg / m 2 Knead under pressure for 4–7 minutes, let stand for 1–2 minutes, then knead again at 1.8–2.5 kg / m². 2 Knead under pressure for 4–7 minutes, let stand for 2–3 minutes, and finally knead at 3.2–3.8 kg / m³. 2 Knead under pressure for 4–7 minutes, then let stand for 2–3 minutes.

[0011] Furthermore, in step S3, the atomized fumigation involves atomizing the composite aqueous solution and then fumigating the spread and rolled tea leaves at a temperature of 25–30°C.

[0012] Furthermore, the fumigation process is as follows: under a temperature of 25–30°C, with an atomization speed of 1.0–1.5 cm. 3 Fumigate for 30–60 minutes at a speed of 2.0–3.0 cm / s, let stand for 8–12 minutes, then atomize at a speed of 2.0–3.0 cm / s. 3 Fumigate for 20-30 minutes, let stand for 5-10 minutes, and repeat the operation 2-4 times.

[0013] Furthermore, the preparation process of the composite aqueous solution is as follows: Agarwood leaves and osmanthus flowers are crushed according to a mass ratio of (8-10):1 to obtain a mixed powder. The mixed powder is then extracted with water at a material-to-liquid ratio of 1:(15-20) g / mL under ultrasonic power of 500-800W and temperature of 50-60℃ for 1-2 hours. After filtration, the composite aqueous solution is obtained.

[0014] Furthermore, in step S3, the fermentation conditions are: relative humidity of 85-90%, temperature of 25-28°C, oxygen concentration of 30-50%, and fermentation time of 4-6 hours.

[0015] Furthermore, in step S3, the baking process is as follows: first, heat to 50-60℃ and bake for 30-40 minutes, then heat to 110-120℃ and bake for 4-6 minutes, cool to room temperature, let stand for 20-30 minutes, then heat to 50-60℃ and bake for 12-15 minutes, then heat to 120-140℃ and bake for 3-5 minutes, cool to room temperature, and then heat to 75-80℃ and bake until the moisture content is 5-6%.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention, through a specific process, can promote the full oxidation and transformation of polyphenols and other internal substances in large-leaf tea during processing, while also better preserving the effective components in black tea. It enhances the flavor and aroma of black tea, resulting in a mellow-tasting black tea with a rich red liquor and a strong and lasting floral aroma, effectively improving the aroma and quality of large-leaf black tea.

[0018] This invention accelerates the enzymatic oxidation of polyphenols and other polyphenolic substances, as well as the transformation of aroma precursors, through specific withering, rolling, and misting of rolled large-leaf tea leaves. This promotes better fermentation of the tea leaves, effectively reduces the grassy and bitter taste of large-leaf tea, induces aroma, and enhances the sweet and mellow flavor, thus effectively improving the taste and flavor of large-leaf black tea. Detailed Implementation

[0019] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0020] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0021] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0022] Example 1

[0023] The method for producing organic large-leaf black tea of ​​the present invention includes the following steps:

[0024] S1. Fresh leaves from large-leaf tea trees (one bud and two leaves, one bud and three leaves, or one bud and four leaves) are picked and evenly spread 6cm apart in a withering trough. Alternating strong and weak wind speeds are then applied to obtain withered tea leaves. The withering temperature is 25℃, and the alternating strong and weak wind speed process is as follows: first, the wind speed is 0.5cm... 3 Blow air at a speed of 1.2 cm / s for 12 minutes, let it stand for 2 minutes, and then blow air at a speed of 1.2 cm / s for 2 minutes. 3 Blow air at / s for 15 minutes, let stand for 1 minute, and repeat blowing air 3 times;

[0025] S2. Place the withered tea leaves in a shaking machine and shake for 4 minutes at a temperature of 25℃ and a speed of 70 r / min. Then remove them and first apply 0.8 kg / m 2 Knead under pressure for 5 minutes, let stand for 1 minute, then knead at 2.5 kg / m². 2 Knead under pressure for 7 minutes, let stand for 3 minutes, and finally knead at 3.2 kg / m³. 2 Knead under pressure for 6 minutes, then let stand for 2 minutes to obtain kneaded tea leaves;

[0026] S3. Spread the rolled tea leaves obtained in S2 to a depth of 8 cm. Atomize the spread rolled tea leaves with the composite aqueous solution at 25°C at an atomization speed of 1.0 cm / min. 3 Fumigate for 60 minutes at a speed of 1 / s, let stand for 10 minutes, and then atomize at a speed of 2.0 cm / s. 3 The mixture is fumigated for 30 minutes, left to stand for 5 minutes, and the process is repeated 4 times. (The preparation process of the compound aqueous solution is as follows: Agarwood leaves and Osmanthus flowers are crushed at a mass ratio of 8:1 to obtain a mixed powder. The mixed powder is then extracted with water at a material-to-liquid ratio of 1:20 g / mL under ultrasonic power of 500W and temperature of 50℃ for 1 hour. After filtration, the compound aqueous solution is obtained.) The mixture is then placed in a fermentation chamber and fermented for 6 hours at a relative humidity of 85%, temperature of 28℃, and oxygen concentration of 30%. The mixture is first heated to 50℃ and baked for 40 minutes, then heated to 115℃ and baked for 4 minutes. After cooling to room temperature, it is left to stand for 20 minutes, then heated to 50℃ and baked for 14 minutes, then heated to 135℃ and baked for 5 minutes. After cooling to room temperature, it is heated to 75℃ and baked until the moisture content is 6%, thus obtaining organic large-leaf black tea.

[0027] Example 2

[0028] The method for producing organic large-leaf black tea of ​​the present invention includes the following steps:

[0029] S1. Fresh leaves from large-leaf tea trees (one bud and two leaves, one bud and three leaves, or one bud and four leaves) are picked and evenly spread 4cm apart in a withering trough. Alternating strong and weak wind speeds are then applied to obtain withered tea leaves. The withering temperature is 30℃, and the alternating strong and weak wind speed process is as follows: first, the leaves are placed in a trough with a wind speed of 0.4cm... 3 Blow air at 1.4 cm / s for 15 minutes, let stand for 1 minute, then blow air at 1.4 cm / s again. 3 Blow air at / s for 13 minutes, let stand for 2 minutes, and repeat blowing air 4 times;

[0030] S2. Place the withered tea leaves in a shaking machine and shake for 3 minutes at a temperature of 30℃ and a speed of 60 r / min. Then remove them and first apply 0.6 kg / m 2 Knead under pressure for 6 minutes, let stand for 2 minutes, then knead at 1.8 kg / m². 2 Knead under pressure for 6 minutes, let stand for 2 minutes, and finally knead at 3.8 kg / m³. 2 Knead under pressure for 7 minutes, then let stand for 3 minutes to obtain kneaded tea leaves;

[0031] S3. Spread the rolled tea leaves obtained in S2 to a depth of 6 cm. Atomize the spread rolled tea leaves with the composite aqueous solution at 28°C at a speed of 1.5 cm / min. 3Fumigate for 50 minutes at a speed of 3.0 cm / s, let stand for 12 minutes, then atomize at a speed of 3.0 cm / s. 3 The mixture is fumigated for 25 minutes, left to stand for 10 minutes, and the process is repeated twice. (The preparation process of the compound aqueous solution is as follows: Agarwood leaves and Osmanthus flowers are crushed at a mass ratio of 10:1 to obtain a mixed powder. The mixed powder is then extracted with water at a material-to-liquid ratio of 1:15 g / mL under ultrasonic power of 800W and temperature of 60℃ for 2 hours. After filtration, the compound aqueous solution is obtained.) The mixture is then placed in a fermentation chamber and fermented for 5 hours at a relative humidity of 90%, temperature of 26℃, and oxygen concentration of 40%. The mixture is first heated to 55℃ and baked for 35 minutes, then heated to 110℃ and baked for 6 minutes. After cooling to room temperature, it is left to stand for 25 minutes, then heated to 55℃ and baked for 15 minutes, then heated to 120℃ and baked for 4 minutes. After cooling to room temperature, it is heated to 80℃ and baked until the moisture content is 5%, thus obtaining organic large-leaf black tea.

[0032] Example 3

[0033] The method for producing organic large-leaf black tea of ​​the present invention includes the following steps:

[0034] S1. Fresh leaves from large-leaf tea trees (one bud and two leaves, one bud and three leaves, or one bud and four leaves) are picked and evenly spread 5cm apart in a withering trough. Alternating strong and weak wind speeds are then applied to obtain withered tea leaves. The withering temperature is 26℃, and the alternating strong and weak wind speed process is as follows: first, the leaves are placed in a trough with a wind speed of 0.6cm / cm². 3 After blowing air at a speed of 1.6 cm / s for 14 minutes, let it stand for 2 minutes, and then blow air at a speed of 1.6 cm / s again. 3 Blow air at / s for 12 minutes, let stand for 1 minute, and repeat blowing air 3 times;

[0035] S2. Place the withered tea leaves in a shaking machine and shake for 5 minutes at a temperature of 28℃ and a speed of 80 r / min. Then remove them and first apply 0.5 kg / m³ of water. 2 Knead under pressure for 7 minutes, let stand for 2 minutes, then knead at 2.0 kg / m². 2 Knead under pressure for 5 minutes, let stand for 2 minutes, and finally knead at 3.5 kg / m². 2 Knead under pressure for 5 minutes, then let stand for 2 minutes to obtain kneaded tea leaves;

[0036] S3. Spread the rolled tea leaves obtained in S2 to a depth of 8 cm. Atomize the spread rolled tea leaves with the composite aqueous solution at a temperature of 30°C and an atomization rate of 1.4 cm / s. 3 Fumigate for 30 minutes at a speed of / s, let stand for 8 minutes, then atomize at a speed of 2.5cm / s. 3The mixture is fumigated for 30 minutes, left to stand for 8 minutes, and the process is repeated 3 times. (The preparation process of the compound aqueous solution is as follows: Agarwood leaves and Osmanthus flowers are crushed at a mass ratio of 9:1 to obtain a mixed powder. The mixed powder is then extracted with water at a material-to-liquid ratio of 1:18 g / mL under ultrasonic power of 600W and temperature of 55℃ for 1.5 hours. After filtration, the compound aqueous solution is obtained.) The mixture is then placed in a fermentation chamber and fermented for 4 hours at a relative humidity of 90%, temperature of 25℃, and oxygen concentration of 50%. The temperature is first raised to 60℃ for baking for 30 minutes, then raised to 120℃ for baking for 5 minutes, cooled to room temperature, left to stand for 30 minutes, then raised to 60℃ for baking for 12 minutes, then raised to 140℃ for baking for 3 minutes, cooled to room temperature, and then raised to 75℃ for baking until the moisture content is 6%, thus obtaining organic large-leaf black tea.

[0037] Comparative Example 1

[0038] The wilting process in this comparative example differs from that in Example 3. The wilting process in this comparative example involves using a wind speed of 1.6 cm⁻¹. 3 The air-blowing process can be carried out for 90 minutes.

[0039] Comparative Example 2

[0040] The kneading process in this comparative example differs from that in Example 3. The kneading process in this comparative example is as follows: at 4.0 kg / m²... 2 Knead under pressure for 10 minutes, then knead at 1.2 kg / m². 2 Knead under pressure for 15 minutes.

[0041] Comparative Example 3

[0042] Compared with Example 3, this comparative example does not undergo atomized fumigation; instead, it is directly fermented after kneading.

[0043] Comparative Example 4

[0044] The baking process in this comparative example differs from that in Example 3. The baking process in this comparative example involves drying at 120°C for 10 minutes, then adjusting the temperature to 90°C and drying until the moisture content is 6%.

[0045] Test Experiment

[0046] (1) Sensory evaluation of large-leaf black tea

[0047] Ten senior tea tasters conducted sensory evaluations of the black teas prepared by the methods of Examples 1-3 and Comparative Examples 1-4 according to the evaluation criteria in Table 1. The full score was 100 points. The scores of each option were totaled, the total score was calculated, and the average score was taken. The evaluation results are shown in Table 2 below.

[0048] Table 1 Sensory Evaluation Criteria

[0049]

[0050]

[0051] Table 2 Sensory Evaluation Results

[0052] project Total Score Example 1 93.2 Example 2 94.9 Example 3 96.4 Comparative Example 1 90.7 Comparative Example 2 91.6 Comparative Example 3 88.2 Comparative Example 4 86.5

[0053] The above results indicate that the large-leaf black tea prepared by the methods of Examples 1-3 of this invention has good sensory evaluation and higher quality. Comparative Examples 1, 2, and 4 used unreasonable withering, rolling, or baking processes, and Comparative Example 3 did not use misting and steaming, which could not effectively promote the full oxidation and transformation of the substances contained in the black tea during the preparation process. As a result, the quality of the prepared black tea decreased, resulting in a lower sensory evaluation score.

[0054] (2) Determination of active ingredient content in large-leaf black tea

[0055] The contents of free amino acids, tea polyphenols, caffeine, and soluble sugars in the black teas prepared by the methods of Examples 1-3 and Comparative Examples 1-4 were determined. Free amino acids were determined according to GB / T 8314-2013 "Determination of Total Free Amino Acids in Tea"; tea polyphenols were determined according to GB / T 8313-2018 "Detection Method for Tea Polyphenols and Catechins in Tea"; caffeine was determined according to GB / T 8312-2013 "Determination of Caffeine in Tea"; and soluble sugars were determined according to the anthrone colorimetric method. The results are shown in Table 3 below.

[0056] Table 3. Content of active ingredients in large-leaf black tea

[0057] project Free amino acids (%) Tea polyphenols (%) Caffeine (%) Soluble sugars (%) Example 1 3.78 9.38 4.12 3.63 Example 2 3.82 9.13 4.15 3.81 Example 3 4.05 8.76 4.23 3.75 Comparative Example 1 3.49 9.53 3.76 3.29 Comparative Example 2 3.66 10.69 3.89 3.42 Comparative Example 3 2.97 14.53 3.13 2.86 Comparative Example 4 3.23 11.72 3.52 3.12

[0058] The above results indicate that embodiments 1-3 of the present invention, through specific and reasonable withering, rolling, misting and steaming, and roasting processes, can effectively promote the conversion of polyphenols, reduce the content of tea polyphenols in the prepared black tea, effectively reduce bitterness and green tea taste, and make the aroma more intense and the taste sweeter after brewing. Compared with embodiment 3, the withering process of comparative example 1 is different, the rolling process of comparative example 2 is different, the misting and steaming process of comparative example 3 is not performed, and the roasting process of comparative example 4 is different, resulting in a decrease in the content of free amino acids, caffeine, and soluble sugars, thus reducing the quality of the black tea.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing organic large-leaf black tea, characterized in that, Includes the following steps: S1. Fresh leaves from large-leaf tea trees (one bud and two leaves, one bud and three leaves, or one bud and four leaves) are picked and evenly spread 4-6 cm into a withering trough. The leaves are then subjected to alternating strong and weak wind speeds to obtain withered tea leaves. The withering temperature is 25-30℃, and the alternating strong and weak wind speed process is as follows: first, the leaves are withered at a wind speed of 0.4-0.6 cm / s. 3 Blow air at a speed of 1.2-1.6 cm / s for 12-15 minutes, let it stand for 1-2 minutes, and then blow air at a speed of 1.2-1.6 cm / s for 12-15 minutes. 3 Blow air at / s for 12-15 minutes, let stand for 1-2 minutes, and repeat blowing 3-4 times; S2. Place the withered tea leaves in a shaking machine for shaking, then remove and knead to obtain kneaded tea leaves; the kneading process is as follows: first at 0.5~0.8 kg / m 2 Knead under pressure for 4-7 minutes, let stand for 1-2 minutes, then knead again at 1.8-2.5 kg / m². 2 Knead under pressure for 4-7 minutes, let stand for 2-3 minutes, and finally knead at 3.2-3.8 kg / m³. 2 Knead under pressure for 4-7 minutes, then let stand for 2-3 minutes; S3. Spread the rolled tea leaves obtained in S2 to a depth of 6-8 cm, perform atomized fumigation on the spread tea leaves, and then place them in a fermentation chamber for fermentation and baking to obtain organic large-leaf black tea. The atomized fumigation is performed by atomizing a compound aqueous solution and then fumigating the spread rolled tea leaves at a temperature of 25-30℃. The fumigation process is as follows: at a temperature of 25-30℃, the atomization speed is 1.0-1.5 cm. 3 Fumigate for 30-60 minutes at a speed of 1 / s, let stand for 8-12 minutes, then atomize at a speed of 2.0-3.0 cm / s. 3 The fumigation is carried out for 20-30 minutes, followed by standing for 5-10 minutes. This process is repeated 2-4 times. The preparation process of the composite aqueous solution is as follows: Agarwood leaves and osmanthus flowers are crushed according to a mass ratio of (8-10):1 to obtain a mixed powder. The mixed powder is then extracted with water at a material-to-liquid ratio of 1:(15-20) g / mL under ultrasonic power of 500-800W and temperature of 50-60℃ for 1-2 hours. After filtration, the composite aqueous solution is obtained.

2. The method for producing organic large-leaf black tea according to claim 1, characterized in that, In step S2, the shaking process is carried out for 3 to 5 minutes at a temperature of 25 to 30°C and a rotation speed of 60 to 80 r / min.

3. The method for producing organic large-leaf black tea according to claim 1, characterized in that, In step S3, the fermentation conditions are: relative humidity of 85-90%, temperature of 25-28℃, oxygen concentration of 30-50%, and fermentation time of 4-6 hours.

4. The method for producing organic large-leaf black tea according to claim 1, characterized in that, In step S3, the baking process is as follows: first, heat the temperature to 50~60℃ and bake for 30~40 minutes, then heat the temperature to 110~120℃ and bake for 4~6 minutes, cool to room temperature, let stand for 20~30 minutes, then heat the temperature to 50~60℃ and bake for 12~15 minutes, then heat the temperature to 120~140℃ and bake for 3~5 minutes, cool to room temperature, and then heat the temperature to 75~80℃ and bake until the moisture content is 5~6%.

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