Kung fu black tea fermentation processing method and production equipment system

Abstract

The invention relates to a fermentation processing method and a production equipment system of Kung Fu black tea, the Kung Fu black tea is prepared by adding lophatherum gracile, dried orange peel and jasmine petals into tea leaves to form a tea leaf mixture, withering, fermenting, shaping and drying, the fermentation comprises pre-fermentation and complete fermentation, the pre-fermentation is auto-oxidation fermentation of the tea leaves, the complete fermentation is microbial fermentation, and the fermentation processing method comprises the following steps of: withering, fermenting, shaping and drying. Carrying out first-step fermentation by adopting a complex microbial inoculant composed of acetic bacteria and enterococcus faecium, and then adding hansenula anomala to carry out second-step fermentation. According to the invention, the problems of sour and stale taste, stuffy and cooked taste and the like of the tea leaves due to the difference of the raw material fermentation processes in the fermentation process of the components are solved. According to the kung fu black tea, the variety and content of aroma substances are increased, meanwhile, the problem that loose tea is insufficient in brewing resistance is solved, tea soup brewed by the kung fu black tea is red, bright and golden in color, the proportion of theaflavin, thearubigin and theabrownin of the kung fu black tea is coordinated, and the tea soup is sweet and moist in mouth, has honey aroma and is lasting in fragrance in a cold cup.

Description

Technical Field

[0001] The invention relates to the technical field of black tea preparation technology and equipment system, and in particular to a Kung Fu black tea fermentation processing method and a production equipment system. Background Art

[0002] Black tea is one of the six major types of tea. It is a fully fermented tea with the special qualities of red tea, red soup and red liquid, hence the name "black tea". Chinese black tea includes Gongfu black tea, broken black tea and small black tea, and their production methods are similar. Black tea contains a variety of nutrients and functional ingredients such as vitamins, caffeine, hydrogen acids, minerals, polysaccharides, tea polyphenols, etc. Studies have shown that black tea has the effect of assisting in lowering blood sugar, blood pressure and blood lipids. The tea pigments in black tea have antioxidant, anti-tumor, anti-inflammatory and antibacterial, anti-mutation, anti-virus and deodorizing effects.

[0003] Black tea is a type of tea named after its tea-making process, rather than a single tea variety. The traditional process of making black tea consists of four steps: withering, rolling, fermentation and drying, among which fermentation is the key step in black tea processing. During the fermentation process, the tea polyphenols in the tea undergo an oxidation reaction to form colored substances such as theaflavins and thearubigins, giving the tea a red soup and red leaves. This unique process makes the tea significantly different in quality and taste from other types of tea, such as unfermented green tea and semi-fermented oolong tea.

[0004] Bamboo leaves ( Lophatherum gracile ) is a perennial herb, which is recorded as a medicinal plant in classics such as "Compendium of Materia Medica". It tastes sweet and is cold in nature. It has the effects of clearing away heat and purging fire, promoting body fluid and quenching thirst, and promoting diuresis and relieving stranguria. It is often used to relieve fever (such as mouth sores, short and red urine) or relieve summer heat. In some areas (such as southern China and Japan), there is a habit of boiling bamboo leaves in water or soaking them in water, especially as a refreshing drink in summer. It has a light taste and a natural grass fragrance or bamboo fragrance.

[0005] Tangerine peel is the peel of mature citrus fruits. Tangerine peel is warm in nature and bitter in taste. It belongs to the spleen and stomach meridians and can relieve abdominal distension, loss of appetite, nausea and vomiting caused by spleen and stomach qi stagnation. Drinking it in water can promote gastrointestinal motility and improve indigestion. It is especially suitable for people with postprandial bloating or qi stagnation type stomach pain. In addition, it is rich in flavonoids (such as hesperidin and quercetin), which have anti-inflammatory and antioxidant effects, may reduce the risk of chronic inflammation, and assist in regulating metabolism (such as blood sugar and blood lipids).

[0006] Therefore, consider adding light bamboo leaves, tangerine peel and other ingredients to the tea leaves to make Kung Fu black tea to increase the nutritional value of black tea. Summary of the invention

[0007] The present invention aims to provide a fermentation processing method and a production system for Kung Fu black tea.

[0008] Another object of the present invention is to provide the above-mentioned Kung Fu black tea with high nutrition, high quality and rich flavor, which takes large-leaf tea as the main ingredient.

[0009] The purpose of the present invention is achieved through the following technical solutions: A fermentation processing method for Kung Fu black tea, characterized in that: the Kung Fu black tea is prepared by adding light bamboo leaves, tangerine peel and jasmine petals to tea leaves to form a tea mixture, withering, fermentation, shaping and drying, wherein the fermentation includes pre-fermentation and full fermentation, wherein the pre-fermentation is a self-oxidation fermentation of tea leaves, and the full fermentation is a microbial fermentation, specifically using acetic acid bacteria ( Acetobacter sp. ) and Enterococcus faecium ( Enterococcus faecium ) to form a composite bacterial agent for the first fermentation, and then add abnormal Hansen yeast ( Hansenula anomala ) for the second fermentation.

[0010] The fermentation processing and production equipment system of the above-mentioned Kung Fu black tea is composed of a withering machine, a fermentation box, a steam generator, a shaping mold, a hydraulic press and a hot air dryer for withering, fermentation, shaping and drying. Specifically, the tea mixture is placed in a withering tank for withering, and then transferred to a fermentation box for pre-fermentation, and then a composite bacterial agent is added for complete fermentation. After the fermentation is completed, it is placed in a steaming basket, and the steam generator valve is opened to allow steam to pass. After the mixture becomes soft, it is placed in a shaping mold and pressed into tea cakes using hydraulic equipment. Finally, the tea cakes are moved to a hot air drying chamber for drying to obtain Kung Fu black tea.

[0011] Furthermore, in the tea mixture, based on weight parts, the tea leaves are 100-120 parts, the jasmine petals are 2-4 parts, the light bamboo leaves are 8-10 parts, and the tangerine peel is 3-5 parts, wherein the tea leaves are any one of the Yunnan large-leaf variety, the Hainan large-leaf variety or the Keemun Castanopsis leaf variety.

[0012] Furthermore, the first step of fermentation is to roll the intermediate product obtained after the pre-fermentation, add a composite bacterial agent consisting of acetic acid bacteria and Enterococcus faecalis to the surface of the intermediate product, and ferment it at a temperature of 28-30°C and a relative humidity of 85-92% for 1-2 hours.

[0013] Furthermore, the acetic acid bacteria and Enterococcus faecium in the composite bacterial agent are composed in a live bacteria mass ratio of 1:1-2, and the total live bacteria mass ratio of the intermediate product to the composite bacterial agent is 100:0.2-0.3.

[0014] Furthermore, the second fermentation step is to add abnormal Hansen yeast after the first fermentation step, place it in a suitable container, seal it, place it at a temperature of 25-28° C. and a relative humidity of 75-85%, and continue fermenting for 3-4 hours.

[0015] Furthermore, in the second step of fermentation, the mass ratio of the intermediate product to the number of live Hansen yeast cells is 100:0.5-0.7.

[0016] Furthermore, the pre-fermentation is carried out in an environment with a temperature of 30-32° C. and a relative humidity of 45-50% for 1-2 hours.

[0017] Furthermore, the shaping is to soften the fully fermented tea leaves with steam at 80-90°C for 30-40 seconds, press them into a suitable mold at a pressure of 5-7kg / cm², and make them into round cakes with a diameter of 8-10cm and a thickness of 1.2-1.5cm.

[0018] Furthermore, the drying is to place the tea cake in a 50-55°C hot air circulation oven and dry it for 1 hour; take it out, place it in a 30-35°C vacuum drying oven, set the vacuum degree to -0.05-0.08MPa, dry it for 10-12 hours, ensure that the moisture content of the product is 1%-3%, and take it out to obtain the finished product.

[0019] A fermentation processing method for Kung Fu black tea, characterized in that it comprises the following steps: (1) Tea pretreatment: Select Yunnan large-leaf tea, Hainan large-leaf tea or Qimen Castanopsis chinensis leaf tea as the main ingredient of black tea, pick fresh leaves with one bud and two leaves, 3-4 cm long, uniform tenderness and free from pests and diseases, wash and dry naturally in the shade, take tea leaves according to the formula, add jasmine petals, light bamboo leaves and tangerine peel (cut into 2-3 cm long and 0.3-0.5 cm wide), mix into a tea mixture, and set aside; (2) Withering and pre-fermentation: Place the tea mixture mixed in step 1 on a bamboo sieve to a thickness of 1-2 cm, place it in an environment at a temperature of 25-28° C. and a relative humidity of 65-75%, wither for 6-8 hours to soften the leaves, then transfer it to an environment at a temperature of 30-32° C. and a relative humidity of 45-50%, pre-ferment it for 1-2 hours, and obtain an intermediate product for later use; (3) Complete fermentation: the intermediate product in step (2) is rolled and piled into a thickness of 12-16 cm, the composite bacterial agent is added to the surface of the intermediate product, the surface is covered with wet cotton cloth, and fermented at a temperature of 28-30°C and a relative humidity of 85-92% for 1-2 hours, taken out, mixed evenly, and abnormal Hansen yeast is added, placed in a suitable container and sealed, and placed at a temperature of 25-28°C and a relative humidity of 75-85%, and fermented for 3-4 hours to obtain fermented tea leaves; the composite bacterial agent is composed of acetic acid bacteria and Enterococcus faecium in a mass ratio of 1:1-2 in terms of the number of live bacteria; the mass ratio of the total number of live bacteria of the intermediate product and the composite bacterial agent in step 2 is 100:0.2-0.3; the mass ratio of the number of live bacteria of the intermediate product and normal Hansen yeast is 100:0.5-0.7; (4) Shaping: After fermentation, the tea leaves are softened with steam at 80-90°C for 30-40 seconds, pressed into a suitable mold at a pressure of 5-7 kg / cm², and made into round cakes with a diameter of 8-10 cm and a thickness of 1.2-1.5 cm; (5) Drying: First place it in a hot air circulation oven at 50~55℃ and dry it for 1 hour; take it out and place it in a vacuum drying oven at 30~35℃, set the vacuum degree to -0.05~-0.08MPa, and dry it for 10~12 hours to ensure that the moisture content of the product is 1%~3%. Then take it out to get the finished Kung Fu black tea.

[0020] The present invention uses a two-stage drying process to quickly characterize and remove surface moisture, and vacuum drying is performed to reduce the volatilization of aromatic substances (such as jasmone and benzyl phenylacetate in jasmine flowers) and effective ingredients (such as limonene and aurantium oil in tangerine peel), thereby retaining the original flavor and nutritional value.

[0021] Since jasmine petals, bamboo leaves and tangerine peel are added to improve the nutritional value of black tea, these ingredients will have an adverse effect on the sensory quality of black tea during the traditional complete auto-oxidation fermentation process. Specifically, the difference in water content of each component causes the tea leaves to stick together during fermentation, the heat is difficult to dissipate, and the local temperature rises suddenly, causing the "heartburn" phenomenon (the bottom of the leaves becomes scorched and produces a burnt smell); secondly, since bamboo leaves, jasmine petals and tangerine peel do not contain tea polyphenols, and the cell structure is quite different, the fermentation process is different, some parts are not completely oxidized, and some components are over-oxidized, making it difficult to control the fermentation process; in the absence of tea polyphenols auto-oxidation, relying on the auto-oxidation fermentation of the main material of tea will cause bamboo leaves, jasmine petals, etc. to be prone to sourness, mildew and other problems, and produce sour and rotten tastes. Bamboo leaf flavonoids in bamboo leaves and synephrine in tangerine peel may generate phenolic derivatives during a long auto-oxidation fermentation process, increase the astringency or irritation of the tea soup, and cover up the sweet and mellow taste of black tea itself.

[0022] Based on this, the present invention adds microorganisms for specific fermentation treatment after a relatively short period of pre-fermentation (auto-oxidation process), so that the system reaches complete fermentation, and also adjusts the fermentation flavor in the tea mixture, solving the problem of taste and quality degradation caused by the addition of light bamboo leaves, tangerine peel and jasmine petals.

[0023] In the first step of fermentation of the mixed raw materials using a composite bacterial agent, acetic acid bacteria fermentation plays a leading role, Enterococcus faecalis grows slowly, and the pH of the fermentation system is adjusted as a whole. A more favorable nutritional environment for yeast growth and fermentation is created through metabolic differences. After the addition of abnormal Hansen yeast, rapid start-up and continuous fermentation can be achieved, acetic acid bacteria continue to oxidize, and Enterococcus faecalis grows rapidly. In this process, Enterococcus faecalis maintains the acidic environment of the fermentation system, allowing the three to form a stable symbiotic system. During the second fermentation process, Hansen yeast dominates the sugar conversion, decomposing the sugar in the tea leaves into alcohol and carbon dioxide, generating flavor substances such as esters and alcohols, giving the black tea a mellow taste and fruity aroma; the ethanol produced by metabolism provides raw materials for the further oxidation reaction of acetic acid bacteria, which can convert the alcohol produced by yeast into acetic acid to form the unique sour taste of black tea. At the same time, the ethanol produced by yeast can undergo esterification reaction with acetic acid, lactic acid, etc. produced in the first fermentation step to generate ester substances with special aroma, further enriching the aroma and flavor of black tea, avoiding excessive mellow aroma in tea leaves, and synergistically enhancing the aroma level; on the other hand, Enterococcus faecium metabolizes to generate lactic acid, adjusts the pH value of the fermentation system, inhibits the reproduction of harmful bacteria (such as Escherichia coli), and prolongs the shelf life. The soft sour taste of lactic acid works synergistically with acetic acid and tea polyphenols to balance the overall taste of black tea. During the second fermentation process, with the growth and metabolism of abnormal Hansen yeast and the enhanced growth and metabolism of Enterococcus faecium, the metabolic process of acetic acid bacteria is gradually restricted, thereby achieving the effect of comprehensively regulating the flavor of tea, making the tea soup strong, fresh and refreshing, with a long-lasting sweetness.

[0024] Theaflavins are the main component that makes black tea soup "bright", and thearubigins are the main component that makes tea soup "red". Their formation gives black tea the quality characteristics of red soup, red leaves, and sweet aroma. During the fermentation process, Hansen yeast and acetic acid bacteria metabolize to produce antioxidant components such as tea polyphenols and polysaccharides, and promote the oxidative polymerization of tea polyphenols to form colored substances such as theaflavins and thearubigins; the short-chain fatty acids (such as butyric acid) produced by Enterococcus faecium and the acidic environment of acetic acid bacteria jointly promote the balance of intestinal flora and enhance immunity; during the fermentation process, the three bacteria synergistically decompose the macromolecules (such as protein and cellulose) in the tea leaves, release small molecule nutrients such as amino acids and B vitamins, and improve the absorption rate.

[0025] A large-leaf Kung Fu black tea, characterized in that: the Kung Fu black tea is made of large-leaf tea leaves as the main ingredient, light bamboo leaves, tangerine peels and jasmine petals are added to form a tea mixture, pre-fermented after withering, and then fully fermented, shaped and dried, the pre-fermentation is the self-oxidation fermentation of the tea leaves, and the full fermentation is microbial fermentation, specifically, a composite bacterial agent composed of acetic acid bacteria and Enterococcus faecium is used for the first step of fermentation, and then abnormal Hansen yeast is added for the second step of fermentation.

[0026] Furthermore, in the tea mixture, based on weight parts, the tea leaves are 100-120 parts, the jasmine petals are 2-4 parts, the light bamboo leaves are 8-10 parts, and the tangerine peel is 3-5 parts, wherein the tea leaves are any one of the Yunnan large-leaf variety, the Hainan large-leaf variety or the Keemun Castanopsis leaf variety.

[0027] Furthermore, the first step of fermentation is to roll the intermediate product obtained after the pre-fermentation, add a composite bacterial agent consisting of acetic acid bacteria and Enterococcus faecalis to the surface of the intermediate product, and ferment it at a temperature of 28-30°C and a relative humidity of 85-92% for 1-2 hours.

[0028] Furthermore, the acetic acid bacteria and Enterococcus faecium in the composite bacterial agent are composed in a live bacteria mass ratio of 1:1-2, and the total live bacteria mass ratio of the intermediate product to the composite bacterial agent is 100:0.2-0.3.

[0029] Furthermore, the second fermentation step is to add abnormal Hansen yeast after the first fermentation step, place it in a suitable container, seal it, place it at a temperature of 25-28° C. and a relative humidity of 75-85%, and continue fermenting for 3-4 hours.

[0030] Furthermore, in the second step of fermentation, the mass ratio of the intermediate product to the number of live Hansen yeast cells is 100:0.5-0.7.

[0031] Furthermore, the pre-fermentation is carried out in an environment with a temperature of 30-32° C. and a relative humidity of 45-50% for 1-2 hours.

[0032] Furthermore, the shaping is to soften the fully fermented tea leaves with steam at 80-90°C for 30-40 seconds, press them into a suitable mold at a pressure of 5-7kg / cm², and make them into round cakes with a diameter of 8-10cm and a thickness of 1.2-1.5cm.

[0033] Furthermore, the drying is to place the tea cake in a 50-55°C hot air circulation oven and dry it for 1 hour; take it out, place it in a 30-35°C vacuum drying oven, set the vacuum degree to -0.05-0.08MPa, dry it for 10-12 hours, ensure that the moisture content of the product is 1%-3%, and take it out to obtain the finished product.

[0034] The present invention has the following technical effects: In the present invention, light bamboo leaves, tangerine peel and jasmine petals are added to tea leaves, and microbial fermentation is further performed after the tea leaves are auto-oxidatively fermented, thereby overcoming the problem that the fermentation process of each component is different during the fermentation process, resulting in the sour and rotten taste of tea leaves, the astringency or irritation of the tea soup is strong, and the sweet and mellow taste of the black tea itself is covered. The increase in the types and contents of aroma substances is achieved, and at the same time, the industry pain point of insufficient tolerance of loose tea is solved. The tea soup brewed from the Kung Fu black tea produced by the process of the present invention is bright red with a golden ring, sweet and mellow with honey fragrance, and has a long-lasting fragrance in the cold cup. The content of theaflavins in this product is greater than 1.5%, and the proportion of thearubigins is as high as more than 15%. The proportion of theaflavins, thearubigins and theabrownins is coordinated, and the flavor is fragrant, which is worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 : Actual picture of Kung Fu black tea prepared in Example 3 of the present invention.

[0036] Figure 2 : Pictures of tea soup after brewing the Gongfu black tea prepared in Example 3 and Comparative Example 3 of the present invention once.

[0037] Figure 3 : Pictures of tea soup of Kung Fu black tea prepared in Example 3 of the present invention and Comparative Example 3 after brewing 6 times. DETAILED DESCRIPTION

[0038] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above-mentioned contents of the present invention.

[0039] The microorganisms used in the present invention are as follows: Hansenula anomala Hansenula anomala ) The deposit number is GDMCC NO.: 2.19, Enterococcus faecium ( Enterococcus faecium ) is deposited with GDMCC NO.: 1.130, acetic acid bacteria ( Acetobacter sp. ) The deposit number is GDMCC NO.: 1.152, and all were purchased from Guangdong Microbiological Culture Collection Center (GDMCC).

[0040] Example 1 A fermentation processing method for Kung Fu black tea, characterized in that it comprises the following steps: (1) Tea pretreatment: Hainan large-leaf tea is selected as the main ingredient of black tea. Fresh leaves with one bud and two leaves are picked. The leaves are 3-4 cm long and are required to be uniformly tender and free of diseases and insect pests. After being cleaned, they are naturally dried in the shade. Tea leaves are taken according to the formula, and jasmine petals, light bamboo leaves and tangerine peel (cut into 2-3 cm long and 0.3-0.5 cm wide) are added. The tea mixture is mixed and set aside. According to weight parts, the tea leaves are 110 parts, jasmine petals are 3 parts, light bamboo leaves are 9 parts, and tangerine peel is 3 parts; (2) Withering and pre-fermentation: Place the tea mixture in step 1 on a bamboo sieve to a thickness of 1-2 cm, place it at a temperature of 25-28°C and a relative humidity of 65-75%, wither for 6 hours to make the leaves soft, then transfer it to an environment with a temperature of 30-32°C and a relative humidity of 45-50%, place it for 1 hour, and obtain an intermediate product for later use; (3) Complete fermentation: The intermediate product in step (2) is rolled and piled into a thickness of 12-16 cm, and the composite bacterial agent is added to the surface of the intermediate product, and the surface is covered with wet cotton cloth, and fermented at a temperature of 28-30°C and a relative humidity of 85-92% for 2 hours, taken out, mixed evenly, and abnormal Hansen yeast is added, placed in a suitable container and sealed, and fermented for 3 hours under conditions of a temperature of 25-28°C and a relative humidity of 75-85%; the composite bacterial agent is composed of acetic acid bacteria and Enterococcus faecium in a mass ratio of 1:1 in terms of the number of live bacteria; the mass ratio of the total number of live bacteria of the intermediate product and the composite bacterial agent in step 2 is 100:0.2; the mass ratio of the number of live bacteria of the intermediate product and the normal Hansen yeast in step 2 is 100:0.5; (4) Shaping: After fermentation, the tea leaves are softened with steam at 80°C for 40 seconds and pressed into a suitable mold at a pressure of 5 kg / cm² to form a round cake with a diameter of 8 cm and a thickness of 1.2-1.5 cm. (5) Drying: First place it in a 55℃ hot air circulation oven and dry it for 1 hour; take it out and place it in a 30℃ vacuum drying oven, set the vacuum degree to -0.05~-0.08MPa, and dry it for 10 hours to ensure that the moisture content of the product is 1%~3%. Take it out and you will get the finished product.

[0041] Example 2 A fermentation processing method for Kung Fu black tea, characterized in that it comprises the following steps: (1) Tea pretreatment: Select Yunnan large-leaf tea as the main ingredient of black tea, pick fresh leaves with one bud and two leaves, 3-4 cm in length, with uniform tenderness and no pests and diseases, wash and dry naturally in the shade, take tea leaves according to the formula, add jasmine petals, light bamboo leaves and tangerine peel (cut into 2-3 cm long and 0.3-0.5 cm wide) in the formula, mix into a tea mixture, and set aside, according to weight, the tea leaves are 100 parts, jasmine petals are 4 parts, light bamboo leaves are 10 parts, and tangerine peel is 5 parts; (2) Withering and pre-fermentation: Place the tea mixture in step 1 on a bamboo sieve to a thickness of 1-2 cm, place it at a temperature of 25-28°C and a relative humidity of 65-75%, wither for 6-8 hours to soften the leaves, then transfer it to an environment with a temperature of 30-32°C and a relative humidity of 45-50%, place it for 1.5 hours, and obtain an intermediate product for later use; (3) Complete fermentation: The intermediate product in step (2) is rolled and piled into a thickness of 12 to 16 cm, and the composite bacterial agent is added to the surface of the intermediate product, and the surface is covered with wet cotton cloth, and fermented at a temperature of 28 to 30°C and a relative humidity of 85 to 92% for 1.5 hours, taken out, mixed evenly, and added with abnormal Hansen yeast, placed in a suitable container and sealed, and continued to ferment for 3.5 hours under the conditions of a temperature of 25 to 28°C and a relative humidity of 75 to 85%; the composite bacterial agent is composed of acetic acid bacteria and Enterococcus faecium in a mass ratio of 1:2 in terms of the number of live bacteria; the mass ratio of the total number of live bacteria of the intermediate product in step 2 to the composite bacterial agent is 100:0.3; the mass ratio of the number of live bacteria of the intermediate product in step 2 to the normal Hansen yeast is 100:0.7; (4) Shaping: After fermentation, the tea leaves are softened with steam at 90°C for 30 seconds and pressed into a suitable mold at a pressure of 7kg / cm² to form a round cake with a diameter of 10cm and a thickness of 1.2-1.5cm. (5) Drying: First place it in a 55℃ hot air circulation oven and dry it for 1 hour; take it out and place it in a 35℃ vacuum drying oven, set the vacuum degree to -0.05~-0.08MPa, dry it for 12 hours, and ensure that the moisture content of the product is 1%~3%. Take it out and you will get the finished product.

[0042] Example 3 A fermentation processing method for Kung Fu black tea, characterized in that it comprises the following steps: (1) Tea pretreatment: Yunnan large-leaf tea is selected as the main ingredient of black tea. Fresh leaves with one bud and two leaves are picked. The leaves are 3-4 cm long and are required to be uniformly tender and free of pests and diseases. After being cleaned, they are naturally dried in the shade. Tea leaves are taken according to the formula, and jasmine petals, light bamboo leaves and tangerine peel (cut into 2-3 cm long and 0.3-0.5 cm wide) are added to the formula. The mixture is mixed into a tea mixture for later use. In terms of weight, the tea leaves are 120 parts, jasmine petals are 2 parts, light bamboo leaves are 8 parts, and tangerine peel is 4 parts. (2) Withering and pre-fermentation: Place the tea mixture in step 1 on a bamboo sieve to a thickness of 1-2 cm, place it at a temperature of 25-28°C and a relative humidity of 65-75%, wither for 6-8 hours to soften the leaves, then transfer it to an environment with a temperature of 30-32°C and a relative humidity of 45-50%, place it for 2 hours, and obtain an intermediate product for later use; (3) Complete fermentation: The intermediate product in step (2) is rolled and piled into a thickness of 12-16 cm, and the composite bacterial agent is added to the surface of the intermediate product, and the surface is covered with wet cotton cloth, and fermented at a temperature of 28-30°C and a relative humidity of 85-92% for 1 hour, taken out, mixed evenly, and abnormal Hansen yeast is added, placed in a suitable container and sealed, and fermented for 4 hours under conditions of a temperature of 25-28°C and a relative humidity of 75-85%; the composite bacterial agent is composed of acetic acid bacteria and Enterococcus faecium in a mass ratio of 1:1.5 in terms of the number of live bacteria; the mass ratio of the total number of live bacteria of the intermediate product in step 2 to the composite bacterial agent is 100:0.25; the mass ratio of the number of live bacteria of the intermediate product in step 2 to the number of live bacteria of normal Hansen yeast is 100:0.6; (4) Shaping: After fermentation, the tea leaves are softened with steam at 85°C for 35 seconds and pressed into a suitable mold at a pressure of 6 kg / cm² to form a round cake with a diameter of 9 cm and a thickness of 1.2-1.5 cm. (5) Drying: First place in a 50℃ hot air circulation oven and dry for 1 hour (preliminary qualitative analysis and removal of surface moisture); take out and place in a 35℃ vacuum drying oven, set the vacuum degree to -0.05~-0.08MPa, dry for 10 hours, ensure that the moisture content of the product is 1%~3%, and then take out to obtain the finished product.

[0043] Comparative Example 1 Compared with Example 3, in the complete fermentation process, yeast is first used for the first fermentation, and then the composite bacterial agent is used for the second fermentation. The remaining steps are the same as those in Example 3.

[0044] Comparative Example 2 Compared with Example 3, in the complete fermentation process, a single acetic acid bacteria was first used for the first fermentation, and then Hansenula spp. was used for the second fermentation. The remaining steps were the same as those in Example 3 (i.e., Enterococcus faecium was used in the fermentation process).

[0045] Comparative Example 3 Compared with Example 3, after the fermentation is complete, the drying process is directly carried out without shaping.

[0046] Effect verification: (I) The appearance, soup color, aroma, taste and leaf bottom of the Kung Fu black tea in Examples 1 to 3 and Comparative Examples 1 to 3 were described and scored by traditional expert sensory evaluation (evaluation standard refers to GB / T23776-2018). A single Yunnan large-leaf tea was used as raw material. The Kung Fu black tea produced according to the process of Example 3 was used as control group 1. A single Yunnan large-leaf tea was used as raw material. The black tea was fermented by traditional autooxidation fermentation (fermentation relative humidity was 90%, fermentation time was 3h), and no microbial fermentation was performed. The remaining steps were consistent with Example 3. The black tea produced was used as control group 2. The sensory evaluation of the samples was performed by password evaluation, using a percentage system, with tea appearance (20), soup color (10), aroma (25), taste (35), and leaf bottom (10). The results are shown in Table 1 below.

[0047] Table 1:

[0048] The Kung Fu black tea prepared by each embodiment and comparative example was compared in terms of appearance, color, aroma, taste, etc. of the brewed tea soup. The overall score of the black tea prepared by conventional auto-oxidation fermentation of a single tea leaf was close to that of the embodiment of the present invention, while the appearance score of the tea obtained by the single tea leaf under the production process of Example 3 was equivalent to that of the present invention, but the physical and chemical properties of the brewed tea soup showed a significant decrease. Comparative Examples 1 and 2 had significant changes in the fermentation process, resulting in a serious decrease in the sensory score of the Kung Fu black tea produced. Comparative Example 3 did not perform a shaping treatment, which also had an adverse effect on the physical and chemical properties of the tea leaves and the tea soup.

[0049] (II) Testing of the content and brewing resistance of tea theaflavins, thearubigins and theabrownins 1. Theaflavin detection National Standard GB / T 30376-2013 "Determination of theaflavins in tea by high performance liquid chromatography" 2. Detection of thearubigins and theabrownins The content of thearubigins and theabrownins was determined in accordance with the agricultural industry standard NY / T3657-2020 "Spectrophotometric method for determination of thearubigins and theabrownins in black tea".

[0050] 2. Amino acid detection According to the national standard GB / T 8314-2002 "Determination of the total amount of free amino acids in tea", the total amount of free amino acids was determined by spectrophotometer at a wavelength of 570 nm using ninhydrin colorimetric reaction. 3. Detection of unoxidized polyphenols According to the national standard GB / T 8313-2002 “Determination of Tea Polyphenols”, the total polyphenol content was determined at a wavelength of 765 nm using Folin phenol reagent for color development.

[0051] 4. Foam resistance The black tea brewing standard is based on the Chinese national standard GB / T 23776-2018 "Tea Sensory Evaluation Method" and related specifications, with standardized tea-to-water ratio (1:50), boiling water temperature (100°C), and fixed brewing time (5 minutes / time).

[0052] Score the color, aroma, and taste of each brew, and set the score for the n+1th time to be lower than 60% of the average score of the previous n times (e.g. the average score of the previous n times is 80 points, and the n+1th time is less than 48 points), then n is determined to be the upper limit of the tea's tolerance to brewing.

[0053] The test results are shown in Table 2.

[0054] Table 2:

[0055] The tea soup of the Kung Fu black tea of ​​Example 3 and Comparative Example 3 brewed once is as follows: Figure 2 , brew 6 times of tea Figure 3 As shown ( Figure 2 and Figure 3 The upper figure is Example 3, and the lower figure is Comparative Example 3). Figure 2 It can be seen that during the first brewing, the tea soup of Example 3 and Comparative Example 3 was bright orange-red with a golden ring, but the tea soup of Example 3 was brighter red than that of Comparative Example 3. Figure 3 As shown, the color of the tea soup in Example 3 becomes lighter, but still appears bright red, which shows that the Kung Fu black tea in Example 3 has excellent brewing resistance, while the tea soup of the sixth brewing in Comparative Example 3 has extremely light color, the dissolution has been significantly reduced, and the brewing resistance has decreased significantly.

[0056] Changes in the content of main aromatic substances in tea: Regarding the improvement of the aroma substance content in tea leaves, the relative contents of the main aroma component linalool and the secondary aroma component geraniol in the black tea prepared in each embodiment and comparative example were detected by solid phase microextraction-gas chromatography-mass spectrometry. The results are shown in Table 3.

[0057] Table 3:

[0058] It can be seen that by combining the short-term specific self-oxidation of the present invention with microbial fermentation, the content of substances such as linalool and geraniol, the characteristic aromatic components in black tea, is effectively increased, and the decomposition of these aromatic components during the shaping process is offset, resulting in a decrease in the quality and flavor of the black tea. In Comparative Example 3, although the tea is not shaped, the decomposition of the aromatic components by steam and other conditions is reduced. However, since the tea cakes are not shaped, these aromatic components are more volatile, which will also cause a decrease in the content of directional components to a certain extent.

Claims

1. A fermentation processing method for Kung Fu black tea, characterized in that: The Kung Fu black tea is prepared by adding light bamboo leaves, tangerine peel and jasmine petals to tea leaves to form a tea mixture, withering, fermentation, shaping and drying, wherein the fermentation includes pre-fermentation and full fermentation, wherein the pre-fermentation is the self-oxidation fermentation of tea leaves, and the full fermentation is microbial fermentation, specifically using acetic acid bacteria ( Acetobacter sp. ) and Enterococcus faecium ( Enterococcus faecium ) to form a composite bacterial agent for the first fermentation, and then add abnormal Hansen yeast ( Hansenula anomala ) for the second fermentation.

2. The fermentation method for kung fu black tea according to claim 1, characterized in that: In the tea mixture, according to weight parts, the tea leaves are 100-120 parts, the jasmine petals are 2-4 parts, the light bamboo leaves are 8-10 parts, and the tangerine peel is 3-5 parts, wherein the tea leaves are any one of the Yunnan large-leaf variety, the Hainan large-leaf variety or the Qimen Castanopsis leaf variety.

3. The fermentation processing method of a Kung Fu black tea according to claim 1 or 2, characterized in that: The first step of fermentation is to roll the intermediate product obtained after the pre-fermentation, add a composite bacterial agent consisting of acetic acid bacteria and Enterococcus faecalis to the surface of the intermediate product, and ferment it at a temperature of 28-30° C. and a relative humidity of 85-92% for 1-2 hours.

4. A fermentation method for kung fu black tea according to any one of claims 1 to 3, characterized in that: The acetic acid bacteria and Enterococcus faecium in the composite bacterial agent are composed in a live bacteria mass ratio of 1:1-2, and the total live bacteria mass ratio of the intermediate product to the composite bacterial agent is 100:0.2-0.

3.

5. The fermentation method for kung fu black tea according to any one of claims 1 to 4, characterized in that: The second step of fermentation is to add abnormal Hansen yeast after the first step of fermentation is completed, place it in a suitable container, seal it, place it at a temperature of 25-28°C and a relative humidity of 75-85%, and continue fermenting for 3-4 hours.

6. The fermentation method for kung fu black tea according to claim 5, characterized in that: In the second step of fermentation, the mass ratio of the intermediate product to the number of live Hansen yeast cells is 100:0.5-0.

7.

7. The fermentation method for kung fu black tea according to claim 6, characterized in that: The pre-fermentation is carried out in an environment with a temperature of 30-32° C. and a relative humidity of 45-50% for 1-2 hours.

8. The fermentation method for kung fu black tea according to claim 7, characterized in that: The drying process is to place the tea cake in a hot air circulation oven at 50-55°C for 1 hour, take it out, place it in a vacuum drying oven at 30-35°C, set the vacuum degree to -0.05-0.08MPa, dry it for 10-12 hours, ensure that the moisture content of the product is 1%-3%, and take it out to obtain the finished product.

9. A fermentation processing method for Kung Fu black tea, characterized in that: The steps include: (1) Tea pretreatment: Yunnan large-leaf tea, Hainan large-leaf tea or Qimen Castanopsis chinensis leaf tea are selected as the main material of black tea, and fresh leaves with one bud and two leaves are picked, with a length of 3-4 cm, and the leaves are required to be uniformly tender and free of diseases and insect pests. After being cleaned, they are naturally dried in the shade. Tea leaves are taken according to the formula, and jasmine petals, light bamboo leaves and tangerine peel are added in the formula to mix into a tea mixture for standby use. The tea mixture contains 100-120 parts of tea leaves, 2-4 parts of jasmine petals, 8-10 parts of light bamboo leaves and 3-5 parts of tangerine peel in parts by weight; (2) Withering and pre-fermentation: Place the tea mixture mixed in step 1 on a bamboo sieve to a thickness of 1-2 cm, place it in an environment at a temperature of 25-28° C. and a relative humidity of 65-75%, wither for 6-8 hours to soften the leaves, then transfer it to an environment at a temperature of 30-32° C. and a relative humidity of 45-50%, pre-ferment it for 1-2 hours, and obtain an intermediate product for later use; (3) Complete fermentation: the intermediate product in step (2) is rolled and piled into a thickness of 12-16 cm, the composite bacterial agent is added to the surface of the intermediate product, the surface is covered with wet cotton cloth, and fermented at a temperature of 28-30°C and a relative humidity of 85-92% for 1-2 hours, taken out, mixed evenly, and abnormal Hansen yeast is added, placed in a suitable container and sealed, and placed at a temperature of 25-28°C and a relative humidity of 75-85%, and fermented for 3-4 hours to obtain fermented tea leaves; the composite bacterial agent is composed of acetic acid bacteria and Enterococcus faecium in a mass ratio of 1:1-2 in terms of the number of live bacteria; the mass ratio of the total number of live bacteria of the intermediate product and the composite bacterial agent in step 2 is 100:0.2-0.3; the mass ratio of the number of live bacteria of the intermediate product and normal Hansen yeast is 100:0.5-0.7; (4) Shaping: After fermentation, the tea leaves are softened with steam at 80-90°C for 30-40 seconds, pressed into a suitable mold at a pressure of 5-7 kg / cm², and made into round cakes with a diameter of 8-10 cm and a thickness of 1.2-1.5 cm; (5) Drying: First place it in a hot air circulation oven at 50~55℃ and dry it for 1 hour; take it out and place it in a vacuum drying oven at 30~35℃, set the vacuum degree to -0.05~-0.08MPa, and dry it for 10~12 hours to ensure that the moisture content of the product is 1%~3%. Then take it out to get the finished Kung Fu black tea.

10. The production equipment system used in the fermentation processing method of Kung Fu black tea according to claim 9, characterized in that: The system consists of a withering machine, a fermentation box, a steam generator, a shaping mold, a hydraulic press and a hot air dryer. Specifically, the tea mixture is placed in a withering tank for withering, then transferred to a fermentation box for pre-fermentation, and then a composite bacterial agent is added for complete fermentation. After the fermentation is completed, the mixture is placed in a steaming basket, and the valve of the steam generator is opened to allow steam to flow. After the mixture becomes soft, it is placed in a shaping mold, and a hydraulic device is used to press the tea cake. Finally, the tea cake is moved to a hot air drying chamber for drying to obtain Gongfu black tea.

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