Fragrant sweet jasmine no. 9 black tea and a preparation method thereof

Abstract

The application belongs to the technical field of tea, and particularly relates to a jasmine No. 9 black tea with a sweet and refreshing fragrance and a preparation method thereof. The preparation method comprises the following steps: (1) weighing jasmine fresh flowers and Yingji tea leaves; (2) washing and drying the jasmine fresh flowers, performing flower processing, and obtaining processed jasmine flowers; the processed jasmine flowers are divided into three parts, i.e. a first part, a second part and a third part; (3) mixing the first part of the processed jasmine flowers and the Yingji tea leaves, and performing scenting to obtain a first tea embryo; (4) scenting the first tea embryo and the second part of the processed jasmine flowers to obtain a second tea embryo; (5) scenting the second tea embryo and the third part of the processed jasmine flowers to obtain finished tea leaves, and performing low-temperature airing on the finished tea leaves to obtain the jasmine No. 9 black tea with a sweet and refreshing fragrance. The jasmine No. 9 black tea has a sweet and refreshing fragrance, and excellent resistance to brewing and quality stability are embodied after repeated brewing.

Description

Technical Field

[0001] This invention belongs to the field of tea technology, specifically relating to a fragrant and sweet Jasmine No. 9 black tea and its preparation method. Background Technology

[0002] In recent years, as consumers' pursuit of quality of life has continued to rise, their demand for tea flavors has also become increasingly diversified. Yinghong No. 9, a high-quality black tea, derives its name from the superior tea tree variety of the same name carefully cultivated by the Guangdong Tea Research Institute. It is made from fresh leaves through meticulous processes such as withering, rolling, fermentation, and drying. Depending on quality, Yinghong No. 9 is divided into four grades: Jin Hao, Jin Mao Hao, Jin Yinghong, and Yinghong No. 9, each with its own unique characteristics.

[0003] Jasmine tea, a type of flower tea, is made by blending freshly blooming jasmine flowers with tea as a base. The finished product does not contain jasmine petals, yet it perfectly blends the aroma of tea and jasmine, resulting in a fresh and lasting fragrance and a mellow and refreshing taste. It is one of the most beloved healthy beverages.

[0004] Although both Yinghong No. 9 tea and jasmine tea have their own mature production processes and cater to different consumer tastes, no product currently combines the advantages of both to create a completely new and unique flavor. Given the market's demand for novel and unique tea products, developing a new type of tea—Jasmine Yinghong No. 9 Tea—that retains the rich and mellow flavor of Yinghong No. 9 while also possessing the refreshing aroma of jasmine tea, is particularly necessary. This innovation would not only fill a market gap but also meet consumers' growing demand for high-quality tea.

[0005] Therefore, providing an effective preparation method for Jasmine Yingjiu Tea has become an urgent technical challenge to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a fragrant and sweet jasmine black tea No. 9 and its preparation method.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for preparing a fragrant and sweet Jasmine No. 9 black tea includes the following steps:

[0009] (1) Weigh out fresh jasmine flowers and Yingjiu tea leaves;

[0010] (2) Wash and dry the fresh jasmine flowers, and then perform a de-flowering process to obtain the processed jasmine flowers; divide the processed jasmine flowers into three parts, namely the first, second and third parts;

[0011] (3) Mix the first batch of jasmine flowers processed in step (2) with Yingjiu tea leaves and scent them. The scenting temperature is 35-45℃ and the scenting time is 18-24h to obtain a first batch of tea leaves.

[0012] (4) Scent the first tea embryo with the second batch of jasmine flowers prepared in step (2) at a temperature of 30-40℃. The mass ratio of jasmine flowers to the first tea embryo is (0.18-0.22):1. The scenting time is 12-15h to obtain the second tea embryo.

[0013] (5) The second tea embryos scented in step (4) are scented with the third batch of jasmine flowers processed in step (2). The scenting temperature is 25-40℃, and the mass ratio of jasmine flowers to first tea embryos is (0.08-0.12):1. The scenting time is 12-15h to obtain the finished tea. The finished tea is then dried at low temperature to obtain the fragrant and sweet Jasmine No. 9 black tea.

[0014] Preferably, the preparation method of Yingjiu tea includes the following steps:

[0015] Step 1: Wither the fresh leaves of Yinghong No. 9;

[0016] Step 2: Knead the withered tea leaves; add the kneaded tea leaves and film-forming agent to a de-clumping machine to de-clump the leaves and obtain de-clumped leaves;

[0017] Step 3: Place the broken-up leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, and carry out fermentation;

[0018] Step 4: Roast the fermented tea leaves and let them cool to obtain Yingjiu tea.

[0019] Preferably, the preparation method of Yingjiu tea includes the following steps:

[0020] Step 1: Spread out fresh Yinghong No. 9 leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, then wither with heated air at 20℃ for 2 hours, followed by withering naturally for 1 hour. Repeat this withering cycle for 14 hours.

[0021] Step 2: First, use a 50-type double-action kneading machine to knead the tea leaves without kneading for 5 minutes, and then knead them under pressure for 10 minutes. Then, add the kneaded tea leaves and film-forming agent to a de-clumping machine to de-clump the tea leaves. The drum speed of the de-clumping machine is 500 r / min, and the time is 10 minutes to obtain de-clumped leaves.

[0022] The mass ratio of film-forming agent to tea leaves is 3:10.

[0023] The film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water.

[0024] The mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is (2-2.5):(1-1.5):1:100.

[0025] Step 3: Place the broken-up leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, using 100-200 U / g of polyphenol oxidase and 50-100 U / g of β-glucosidase per gram of broken-up leaves. The broken-up leaves should be laid to a thickness of 6-10 cm. Maintain the temperature in the chamber at 25-28℃ and the relative humidity at 96-98%. The fermentation time is 8-12 hours.

[0026] Step 4: Stir-fry the fermented tea leaves at 300℃ for 10 minutes using a tea-frying machine; then bake at 110℃ for 3 hours, spreading the leaves to a thickness of 2cm; finally bake at 80℃ for 6 hours, spreading the leaves to a thickness of 2cm; cool to obtain Yingjiu tea.

[0027] Preferably, in step (3), a mixed material is added during the scenting process, and the mass ratio of the mixed material, fresh jasmine flowers and Yingjiu tea leaves is (0.04-0.06):(0.28-0.32):1.

[0028] Preferably, the mixed material comprises the following raw materials in parts by weight: 13-17 parts of ginger, 25-30 parts of dried tangerine peel, 13-19 parts of osmanthus, 22-26 parts of rose, 23-27 parts of passion fruit, 0.5-1.2 parts of lychee, and 10-15 parts of magnolia.

[0029] Preferably, the mixed material comprises the following raw materials in parts by weight: 15 parts of ginger, 28 parts of dried tangerine peel, 16 parts of osmanthus, 25 parts of rose, 24 parts of passion fruit, 0.51 parts of lychee, and 13 parts of magnolia.

[0030] Preferably, the method for preparing the mixed material includes the following steps:

[0031] S1: Select small yellow ginger, dried tangerine peel, osmanthus, rose, passion fruit, lychee and magnolia, wash them, remove the outer shell and pit of passion fruit and lychee, then dry them to a moisture content of 8wt%, and grind them to less than 60 mesh to obtain a mixed powder.

[0032] S2: Add 6 times the mass of water and 0.2% glucose (by mass fraction of the mixed powder) to the mixed powder, mix thoroughly, sterilize, and obtain the fermentation raw material. Add microbial agents to the fermentation raw material, including *Lactobacillus plantarum*, *Bifidobacterium breve*, and *Lactobacillus gasseri*. The amount of microbial agents in the fermentation raw material is (2-6)×10. 7The CFU / mL of the bacterial agent contained Lactobacillus plantarum, Bifidobacterium breve and Lactobacillus gasseri in a ratio of 1:(0.3-0.5):(1.4-1.7). The agent was anaerobic fermented at 37℃ for 3-5 days. After fermentation, the agent was sterilized, filtered through a 0.45μm filter membrane, and spray-dried to a moisture content of 8wt% to obtain the mixed material.

[0033] Preferably, during the scenting process in step (3), the mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 5 hours until the scenting process is completed.

[0034] Preferably, during the scenting process in step (4), the mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 8 hours until the scenting process is completed.

[0035] Preferably, during the scenting process in step (5), the mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 10 hours until the scenting process is completed.

[0036] Preferably, the finished tea obtained in step (5) is sun-dried at a low temperature of 30-45℃ for 48-72 hours, and then inspected for quality. If it passes the inspection, it is packaged.

[0037] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0038] 1. This invention cleverly blends the rich flavor of Yinghong No. 9 black tea with the refreshing fragrance of jasmine. It retains the robust and mellow character of black tea while incorporating the elegant and fragrant aroma of jasmine, creating a unique flavor experience and providing consumers with a refreshing sensory enjoyment. Through precise control of fermentation and multiple scenting processes, the tea leaves undergo full transformation, resulting in a smooth, delicate, and full-bodied tea soup with no noticeable astringency. It offers both palatability and depth, making it suitable for all ages and tea drinkers with different preferences. Furthermore, this product innovatively develops a new type of floral-scented black tea based on the traditional Yingde black tea "Yinghong No. 9," enriching the product portfolio and expanding the development space of the industrial chain.

[0039] 2. This invention achieves efficient adsorption and fusion of aromas during multiple scenting processes by thoroughly mixing fresh jasmine flowers and Yinghong No. 9 tea leaves. The overall aroma is rich and layered, exhibiting a unique style that is fresh with a hint of sweetness and mellow with a refreshing aftertaste. After repeated brewing tests, using the standard gaiwan method, the tea soup retains a certain aroma and flavor even after more than 30 infusions. The final infusion is sweet with a long-lasting fragrance, demonstrating excellent brewing endurance and quality stability.

[0040] 3. The addition of polyphenol oxidase and β-glucosidase during the fermentation process of Yingjiu tea in this invention can increase the content of theaflavins in the tea. Furthermore, the pre-spraying of film-forming agents on the tea can improve the adhesion effect of the enzymes. At the same time, by adding water-soluble chitosan, sodium alginate and soy protein isolate in specific proportions, the fermentation process can be affected, increasing the content of 6-methyl-5-hepten-2-one and methyl salicylate.

[0041] 4. The mixed material prepared by this invention is fermented with a specific microbial agent. The mixed material is rich in more fragrant and sweet components, which work synergistically with the aroma components in Yingjiu tea and jasmine flowers to increase the number of times the product can be brewed. After repeated brewing tests, the tea soup still retains a certain aroma and taste when brewed more than 30 times using the standard gaiwan method. The tea soup is sweet and has a long-lasting fragrance, which shows excellent brewing endurance and quality stability. Detailed Implementation

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] All raw materials used in the following embodiments of the present invention are commercially available products:

[0044] Water-soluble chitosan with a molecular weight of 900 Da.

[0045] Soy protein isolate, Lanzhou Waterles Biotechnology Co., Ltd.

[0046] Lactobacillus plantarum, catalog number: CCTCC AB 2010210. China Center for Type Culture Collection.

[0047] Lactobacillus bulgaricus, ID: CCTCC CB 20082295; China Center for Type Culture Collection.

[0048] Bifidobacterium breve, catalog number: HZB231440, Zhengzhou Fangjue Biotechnology Co., Ltd.

[0049] Lactobacillus delbrueckii, catalog number: HZB139506, Wuhan Gray Algae Biotechnology Co., Ltd.

[0050] Lactobacillus gasseri, strain number: HZB138217, Zhengzhou Fangjue Biotechnology Co., Ltd.

[0051] Lactobacillus rhamnosus, catalog number: HZB197282, from Zhengzhou Fangjue Biotechnology Co., Ltd.

[0052] Example 1

[0053] This embodiment provides a method for preparing a fragrant and sweet Jasmine No. 9 black tea, which includes the following steps:

[0054] (1) Select a certain amount of fresh jasmine flowers and Yingjiu tea leaves;

[0055] The preparation method of Yingjiu tea includes the following steps:

[0056] Step 1: Spread out fresh Yinghong No. 9 leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, then wither with heated air at 20℃ for 2 hours, then wither naturally for 1 hour, and repeat the withering cycle for 14 hours.

[0057] Step 2: Using a 50-type double-action kneading machine, first knead the tea leaves without kneading for 5 minutes, then knead them under pressure for 10 minutes. Add the kneaded tea leaves and film-forming agent together to a de-clumping machine for de-clumping. The drum speed of the de-clumping machine is 500 r / min, and the time is 10 minutes, resulting in de-clumped leaves. The mass ratio of film-forming agent to tea leaves is 3:10. The film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water. The mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is 2.2:2.3:1:100.

[0058] Step 3: Place the kneaded leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, using 150 U / g polyphenol oxidase and 70 U / g β-glucosidase per kneaded leaf. The kneaded leaves should be laid to a thickness of 10 cm. Maintain the temperature in the chamber at 27℃ and the relative humidity at 97%. Fermentation time is 10 hours.

[0059] Step 4: Stir-fry the fermented tea leaves at 300℃ for 10 minutes using a tea-frying machine; then bake at 110℃ for 3 hours, spreading the leaves to a thickness of 2cm; finally bake at 80℃ for 6 hours, spreading the leaves to a thickness of 2cm; cool to obtain Yingjiu tea.

[0060] (2) Wash the fresh jasmine flowers and place them in a greenhouse at 25℃ to dry. After drying for 3 hours, perform the decanting process. The pile thickness during the decanting process should be 20cm, and the pile temperature should reach 30±2℃ for decanting (if the temperature is too high, spread them out to dissipate heat and cool down). The decanting process takes 12 hours to obtain the processed fresh jasmine flowers. Divide the fresh jasmine flowers into three portions, namely the first to the third portions, for the first, second and third scenting processes, respectively.

[0061] (3) Mix the first batch of processed jasmine flowers, Yingjiu tea leaves and mixed materials, and perform a scenting process at a temperature of 35°C. The mass ratio of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is 0.05:0.3:1. The scenting time is 18 hours to obtain a tea embryo. The mixture of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is turned over once every 5 hours until the scenting process is completed.

[0062] The mixed ingredients include the following ingredients in parts by weight: 3 parts ginger, 3 parts dried tangerine peel, 4 parts osmanthus, 4 parts rose, 3 parts passion fruit, 1 part lychee, and 2 parts magnolia.

[0063] The preparation method of the mixed material includes the following steps:

[0064] S1: Select small yellow ginger, dried tangerine peel, osmanthus, rose, passion fruit, lychee and magnolia, wash them, remove the outer shell and pit of passion fruit and lychee, and then dry them to a moisture content of 8wt%. Mix them according to the above mass proportions and grind them to less than 60 mesh to obtain mixed powder.

[0065] S2: Add 6 times the mass of water and 0.2% glucose (by mass fraction of the mixed powder) to the mixed powder, mix thoroughly, sterilize, and obtain the fermentation raw material. Add microbial agents to the fermentation raw material, including *Lactobacillus plantarum*, *Bifidobacterium breve*, and *Lactobacillus gasseri*, at a dosage of 4 × 10⁻⁶. 7 The viable count ratio of Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus gasseri in the bacterial agent was 1:0.4:1.6. The mixture was anaerobic fermented at 37℃ for 4 days. After fermentation, the mixture was sterilized, filtered through a 0.45μm filter membrane, and spray-dried to a moisture content of 8wt% to obtain the mixed material.

[0066] (4) Mix the scented primary tea embryo with the second portion of jasmine flowers prepared in step (2) and scent it at a temperature of 30°C. The mass ratio of jasmine flowers to primary tea embryo is 0.2:1. The scenting time is 12 hours to obtain secondary tea embryo.

[0067] (5) The scented tea embryos and the second batch of jasmine flowers prepared in step (2) are scented at a temperature of 25°C. The mass ratio of jasmine flowers to tea embryos is 0.1:1. The scenting time is 12 hours. The mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 10 hours to obtain the finished tea. The finished tea is then dried at a low temperature of 30°C for 48 hours. After drying, the tea is inspected to obtain the fragrant and sweet Jasmine No. 9 black tea.

[0068] Example 2

[0069] This embodiment provides a method for preparing a fragrant and sweet Jasmine No. 9 black tea, which includes the following steps:

[0070] (1) Select a certain amount of fresh jasmine flowers and Yingjiu tea leaves;

[0071] The preparation method of Yingjiu tea includes the following steps:

[0072] Step 1: Spread out fresh Yinghong No. 9 leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, then wither with heated air at 20℃ for 2 hours, then wither naturally for 1 hour, and repeat the withering cycle for 14 hours.

[0073] Step 2: Using a 50-type double-action kneading machine, first knead the tea leaves without kneading for 5 minutes, then knead them under pressure for 10 minutes. Add the kneaded tea leaves and film-forming agent together to a de-clumping machine for de-clumping. The drum speed of the de-clumping machine is 500 r / min, and the time is 10 minutes, resulting in de-clumped leaves. The mass ratio of film-forming agent to tea leaves is 3:10. The film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water. The mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is 2:1.5:1:100.

[0074] Step 3: Place the rolled leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, using 200 U / g of polyphenol oxidase and 50 U / g of β-glucosidase. The rolled leaves should be 10 cm thick, and the temperature inside the chamber should be maintained at 25℃ and 98% relative humidity for 8 hours.

[0075] Step 4: Stir-fry the fermented tea leaves at 300℃ for 10 minutes using a tea-frying machine; then bake at 110℃ for 3 hours, spreading the leaves to a thickness of 2cm; finally bake at 80℃ for 6 hours, spreading the leaves to a thickness of 2cm; cool to obtain Yingjiu tea.

[0076] (2) Wash the fresh jasmine flowers and place them in a greenhouse at 30℃ to dry. After drying for 5 hours, perform the decanting process. The pile thickness during the decanting process should be 20cm, and the pile temperature should reach 30±2℃ for decanting (if the temperature is too high, spread them out to dissipate heat and cool down). The decanting process takes 12 hours to obtain the processed fresh jasmine flowers. Divide the fresh jasmine flowers into three portions, namely the first to the third portions, for the first, second and third scenting processes, respectively.

[0077] (3) Mix the first batch of processed jasmine flowers, Yingjiu tea leaves and mixed materials and scent them at a temperature of 45°C. The mass ratio of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is 0.05:0.3:1. The scenting time is 24 hours to obtain a tea embryo. The mixture of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is turned over once every 5 hours until the scenting is completed.

[0078] The preparation method of the mixed material includes the following steps:

[0079] S1: Select small yellow ginger, dried tangerine peel, osmanthus, rose, passion fruit, lychee and magnolia, wash them, remove the outer shell and pit of passion fruit and lychee, and then dry them to a moisture content of 8wt%. Mix them according to the above mass proportions and grind them to less than 60 mesh to obtain mixed powder.

[0080] S2: Add 6 times the mass of water and 0.2% glucose (by mass fraction of the mixed powder) to the mixed powder, mix thoroughly, sterilize, and obtain the fermentation raw material. Add microbial agents to the fermentation raw material, including *Lactobacillus plantarum*, *Bifidobacterium breve*, and *Lactobacillus gasseri*, at a dosage of 4 × 10⁻⁶. 7 The viable count ratio of Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus gasseri in the bacterial agent was 1:0.4:1.6. The mixture was anaerobic fermented at 37℃ for 4 days. After fermentation, the mixture was sterilized, filtered through a 0.45μm filter membrane, and spray-dried to a moisture content of 8wt% to obtain the mixed material.

[0081] (4) Mix the scented primary tea embryo with the second portion of jasmine flowers prepared in step (2) and scent it at a temperature of 40°C. The mass ratio of jasmine flowers to primary tea embryo is 0.2:1. The scenting time is 15 hours to obtain secondary tea embryo.

[0082] (5) Mix the scented secondary tea embryos with the second portion of jasmine flowers prepared in step (2) and scent them at a temperature of 40°C. The mass ratio of jasmine flowers to primary tea embryos is 0.1:1. The scenting time is 15 hours. The mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 10 hours to obtain the finished tea. The finished tea is then dried at a low temperature of 30°C for 48 hours. After drying, the tea is inspected to obtain fragrant and sweet Jasmine No. 9 black tea.

[0083] Example 3

[0084] This embodiment provides a method for preparing a fragrant and sweet Jasmine No. 9 black tea, which includes the following steps:

[0085] (1) Select a certain amount of fresh jasmine flowers and Yingjiu tea leaves;

[0086] The preparation method of Yingjiu tea includes the following steps:

[0087] Step 1: Spread out fresh Yinghong No. 9 leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, then wither with heated air at 20℃ for 2 hours, then wither naturally for 1 hour, and repeat the withering cycle for 14 hours.

[0088] Step 2: Using a 50-type double-action kneading machine, first knead the tea leaves without kneading for 5 minutes, then knead them under pressure for 10 minutes. Add the kneaded tea leaves and film-forming agent together to a de-clumping machine for de-clumping. The drum speed of the de-clumping machine is 500 r / min, and the time is 10 minutes, resulting in de-clumped leaves. The mass ratio of film-forming agent to tea leaves is 3:10. The film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water. The mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is 2.5:1:1:100.

[0089] Step 3: Place the rolled leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, using 100 U / g of polyphenol oxidase and 100 U / g of β-glucosidase respectively. The rolled leaf layer in the fermentation chamber should be 10 cm thick, the temperature inside the chamber should be maintained at 25℃, the relative humidity at 98%, and the fermentation time should be 12 hours.

[0090] Step 4: Stir-fry the fermented tea leaves at 300℃ for 10 minutes using a tea-frying machine; then bake at 110℃ for 3 hours, spreading the leaves to a thickness of 2cm; finally bake at 80℃ for 6 hours, spreading the leaves to a thickness of 2cm; cool to obtain Yingjiu tea.

[0091] (2) Wash the fresh jasmine flowers and place them in a greenhouse at 28℃ to dry. After drying for 4 hours, perform the decanting process. The pile thickness during the decanting process should be 20cm, and the pile temperature should reach 30±2℃ for decanting (if the temperature is too high, spread them out to dissipate heat and cool down). The decanting process takes 12 hours to obtain the processed fresh jasmine flowers. Divide the fresh jasmine flowers into three portions, namely the first to the third portions, for the first, second and third scenting processes, respectively.

[0092] (3) Mix the first batch of processed jasmine flowers, Yingjiu tea leaves and mixed materials, and perform a scenting process at a temperature of 40°C. The mass ratio of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is 0.05:0.3:1. The scenting time is 20 hours to obtain a tea embryo. The mixture of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is turned over once every 5 hours until the scenting process is completed.

[0093] The preparation method of the mixed material includes the following steps:

[0094] S1: Select small yellow ginger, dried tangerine peel, osmanthus, rose, passion fruit, lychee and magnolia, wash them, remove the outer shell and pit of passion fruit and lychee, and then dry them to a moisture content of 8wt%. Mix them according to the above mass proportions and grind them to less than 60 mesh to obtain mixed powder.

[0095] S2: Add 6 times the mass of water and 0.2% glucose (by mass fraction of the mixed powder) to the mixed powder, mix thoroughly, sterilize, and obtain the fermentation raw material. Add microbial agents to the fermentation raw material, including *Lactobacillus plantarum*, *Bifidobacterium breve*, and *Lactobacillus gasseri*, at a dosage of 4 × 10⁻⁶. 7 The bacterial agent contained Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus gasseri in a ratio of 1:0.4:1.6 CFU / mL. It was anaerobic fermented at 37℃ for 4 days. After fermentation, it was sterilized, filtered through a 0.45μm filter membrane, and spray-dried to a moisture content of 8wt% to obtain the mixed material.

[0096] (4) Mix the scented primary tea embryo with the second portion of jasmine flowers prepared in step (2) and scent it at a temperature of 35°C. The mass ratio of jasmine flowers to primary tea embryo is 0.2:1. The scenting time is 14 hours to obtain secondary tea embryo.

[0097] (5) Mix the scented secondary tea embryos with the first batch of jasmine flowers prepared in step (2) and scent them at a temperature of 35°C. The mass ratio of jasmine flowers to primary tea embryos is 0.1:1. The scenting time is 14 hours. The mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 10 hours to obtain the finished tea. The finished tea is then dried at a low temperature of 30°C for 48 hours. After drying, the tea is inspected to obtain the fragrant and sweet Jasmine No. 9 black tea.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 3 is that no mixed materials were added.

[0100] This comparative example provides a method for preparing a fragrant and sweet Jasmine No. 9 black tea, including the following steps:

[0101] (1) Select a certain amount of fresh jasmine flowers and Yingjiu tea leaves;

[0102] The preparation method of Yingjiu tea includes the following steps:

[0103] Step 1: Spread out fresh Yinghong No. 9 leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, then wither with heated air at 20℃ for 2 hours, then wither naturally for 1 hour, and repeat the withering cycle for 14 hours.

[0104] Step 2: Using a 50-type double-action kneading machine, first knead the tea leaves without kneading for 5 minutes, then knead them under pressure for 10 minutes. Add the kneaded tea leaves and film-forming agent together to a de-clumping machine for de-clumping. The drum speed of the de-clumping machine is 500 r / min, and the time is 10 minutes, resulting in de-clumped leaves. The mass ratio of film-forming agent to tea leaves is 3:10. The film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water. The mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is 2.2:2.3:1:100.

[0105] Step 3: Place the rolled leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, using 150 U / g of polyphenol oxidase and 70 U / g of β-glucosidase. The rolled leaves should be 10 cm thick, and the temperature inside the chamber should be maintained at 27℃ and 97% relative humidity for 10 hours.

[0106] Step 4: Stir-fry the fermented tea leaves at 300℃ for 10 minutes using a tea-frying machine; then bake at 110℃ for 3 hours, spreading the leaves to a thickness of 2cm; finally bake at 80℃ for 6 hours, spreading the leaves to a thickness of 2cm; cool to obtain Yingjiu tea.

[0107] (2) Wash the fresh jasmine flowers and place them in a greenhouse at 25℃ to dry. After drying for 3 hours, perform the decanting process. The pile thickness during the decanting process should be 20cm, and the pile temperature should reach 30±2℃ for decanting (if the temperature is too high, spread them out to dissipate heat and cool down). The decanting process takes 12 hours to obtain the processed fresh jasmine flowers. Divide the fresh jasmine flowers into three portions, namely the first to the third portions, for the first, second and third scenting processes, respectively.

[0108] (3) Mix the first batch of processed jasmine flowers and Yingjiu tea leaves and scent them at a temperature of 35°C. The mass ratio of fresh jasmine flowers to Yingjiu tea leaves is 0.3:1. The scenting time is 18 hours to obtain a tea embryo. The mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 5 hours until the scenting is completed.

[0109] (4) Mix the scented primary tea embryo with the second portion of jasmine flowers prepared in step (2) and scent it at a temperature of 30°C. The mass ratio of jasmine flowers to primary tea embryo is 0.2:1. The scenting time is 12 hours to obtain secondary tea embryo.

[0110] (5) Mix the scented secondary tea embryos with the third portion of jasmine flowers prepared in step (2) and scent them at a temperature of 25°C. The mass ratio of jasmine flowers to primary tea embryos is 0.1:1. The scenting time is 12 hours. The mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 10 hours to obtain the finished tea. The finished tea is then dried at a low temperature of 30°C for 48 hours. After drying, the tea is inspected to obtain fragrant and sweet Jasmine No. 9 black tea.

[0111] Comparative Example 2

[0112] The difference between this comparative example and Example 3 is that the preparation methods of the mixed materials are different.

[0113] The preparation method of the mixed material includes the following steps:

[0114] S1: Select small yellow ginger, dried tangerine peel, osmanthus, rose, passion fruit, lychee and magnolia. After washing them, remove the outer shell and pit of passion fruit and lychee. Then dry them in the sun until the moisture content is 8wt%. Grind them to less than 60 mesh to obtain the mixed material.

[0115] Comparative Example 3

[0116] The difference between this comparative example and Example 3 is that the inoculum includes *Lactobacillus rhamnosus*, *Lactobacillus delbrueckii*, and *Lactobacillus bulgaricus*, and the amount of inoculum used in the fermentation feed is 4 × 10⁻⁶. 7 The CFU / mL concentration of the bacterial agent contained Lactobacillus rhamnosus, Lactobacillus delbrueckii, and Lactobacillus bulgaricus in a ratio of 1:0.4:1.6.

[0117] Comparative Example 4

[0118] The difference between this comparative example and Example 3 is that the ratio of live bacteria of Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus gasseri in the bacterial agent is 1:1:1.

[0119] Comparative Example 5

[0120] The difference between this comparative example and Example 3 is that the ratio of viable Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus gasseri in the bacterial agent is 1.2:1:0.5.

[0121] Comparative Example 6

[0122] The difference between this comparative example and Example 3 is that no film-forming agent was used.

[0123] A method for preparing a fragrant and sweet Jasmine No. 9 black tea includes the following steps:

[0124] (1) Select a certain amount of fresh jasmine flowers and Yingjiu tea leaves;

[0125] The preparation method of Yingjiu tea includes the following steps:

[0126] Step 1: Spread out fresh Yinghong No. 9 leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, then wither with heated air at 20℃ for 2 hours, then wither naturally for 1 hour, and repeat the withering cycle for 14 hours.

[0127] Step 2: First, knead the tea leaves without kneading for 5 minutes using a 50-type double-action kneading machine, and then knead them under pressure for 10 minutes. Then, add the kneaded tea leaves to a de-clumping machine to de-clump them. The drum speed of the de-clumping machine is 500 r / min, and the time is 10 minutes to obtain de-clumped leaves.

[0128] Step 3: Place the rolled leaves in the fermentation chamber, add polyphenol oxidase and β-glucosidase, using 150 U / g of polyphenol oxidase and 70 U / g of β-glucosidase. The rolled leaves should be 10 cm thick, and the temperature inside the chamber should be maintained at 27℃ and 97% relative humidity for 10 hours.

[0129] Step 4: Stir-fry the fermented tea leaves at 300℃ for 10 minutes using a tea-frying machine; then bake at 110℃ for 3 hours, spreading the leaves to a thickness of 2cm; finally bake at 80℃ for 6 hours, spreading the leaves to a thickness of 2cm; cool to obtain Yingjiu tea.

[0130] (2) Wash the fresh jasmine flowers and place them in a greenhouse at 25℃ to dry. After drying for 3 hours, perform the decanting process. The pile thickness during the decanting process should be 20cm, and the pile temperature should reach 30±2℃ for decanting (if the temperature is too high, spread them out to dissipate heat and cool down). The decanting process takes 12 hours to obtain the processed fresh jasmine flowers. Divide the fresh jasmine flowers into three portions, namely the first to the third portions, for the first, second and third scenting processes, respectively.

[0131] (3) Mix the first batch of processed jasmine flowers, Yingjiu tea leaves and mixed materials, and perform a scenting process at a temperature of 35°C. The mass ratio of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is 0.05:0.3:1. The scenting time is 18 hours to obtain a tea embryo. The mixture of mixed materials, fresh jasmine flowers and Yingjiu tea leaves is turned over once every 5 hours until the scenting process is completed.

[0132] The mixed ingredients include the following ingredients in parts by weight: 3 parts ginger, 3 parts dried tangerine peel, 4 parts osmanthus, 4 parts rose, 3 parts passion fruit, 1 part lychee, and 2 parts magnolia.

[0133] The preparation method of the mixed material includes the following steps:

[0134] S1: Select small yellow ginger, dried tangerine peel, osmanthus, rose, passion fruit, lychee and magnolia, wash them, remove the outer shell and pit of passion fruit and lychee, and then dry them to a moisture content of 8wt%. Mix them according to the above mass proportions and grind them to less than 60 mesh to obtain mixed powder.

[0135] S2: Add 6 times the mass of water and 0.2% glucose (by mass fraction of the mixed powder) to the mixed powder, mix thoroughly, sterilize, and obtain the fermentation raw material. Add microbial agents to the fermentation raw material, including *Lactobacillus plantarum*, *Bifidobacterium breve*, and *Lactobacillus gasseri*, at a dosage of 4 × 10⁻⁶. 7 The viable count ratio of Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus gasseri in the bacterial agent was 1:0.4:1.6. The mixture was anaerobic fermented at 37℃ for 4 days. After fermentation, the mixture was sterilized, filtered through a 0.45μm filter membrane, and spray-dried to a moisture content of 8wt% to obtain the mixed material.

[0136] (4) Mix the scented primary tea embryo with the second portion of jasmine flowers prepared in step (2) and scent it at a temperature of 30°C. The mass ratio of jasmine flowers to primary tea embryo is 0.2:1. The scenting time is 12 hours to obtain secondary tea embryo.

[0137] (5) Mix the scented secondary tea embryos with the third portion of jasmine flowers prepared in step (2) and scent them at a temperature of 25°C. The mass ratio of jasmine flowers to primary tea embryos is 0.1:1. The scenting time is 12 hours. The mixture of fresh jasmine flowers and Yingjiu tea leaves is turned over once every 10 hours to obtain the finished tea. The finished tea is then dried at a low temperature of 30°C for 48 hours. After drying, the tea is inspected to obtain fragrant and sweet Jasmine No. 9 black tea.

[0138] Comparative Example 7

[0139] The difference between this comparative example and Example 3 is that the film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water; the mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is 1.8:1.8:1.9:100.

[0140] Comparative Example 8

[0141] The difference between this comparative example and Example 3 is that the film-forming agent is prepared by dissolving water-soluble chitosan and soy protein isolate in water; the mass ratio of water-soluble chitosan, soy protein isolate and water is 2.75:2.75:100.

[0142] Performance testing

[0143] 1. Testing of the main components of Yingjiu tea prepared in step (1) of Examples 1-3 and Comparative Examples 6-8:

[0144] (1) Theaflavins are the main quality components of black tea in terms of flavor and color, and play an important role in the color, aroma, taste and quality of black tea. The content of theaflavins in Yingjiu tea was determined using conventional methods (ferrous tartrate colorimetric method).

[0145] (2) The aroma of 6-methyl-5-hepten-2-one in black tea is characterized by a fresh fragrance, while the aroma of methyl salicylate is characterized by a sweet fragrance. Headspace solid-phase microextraction (HS-SPME) was used to adsorb the aroma components of Jasmine No. 9 black tea, and gas chromatography-mass spectrometry was used for analysis. The contents of 6-methyl-5-hepten-2-one and methyl salicylate were statistically analyzed. The peak area of ​​the compound in Comparative Example 6 was set to 1, and the results of the other examples and comparative examples were the ratio of their peak areas to the peak areas of Comparative Example 6.

[0146] The results are shown in Table 1.

[0147] Table 1. Results of Ying-Jiu Tea Test

[0148]

[0149] As shown in Table 1, the Yingjiu tea prepared in Examples 1-3 has a high content of theaflavins, 6-methyl-5-hepten-2-one and methyl salicylate, which gives the product a more refreshing aroma and sweet taste.

[0150] In Comparative Example 6, no film-forming agent was used, and the contents of theaflavins, 6-methyl-5-hepten-2-one, and methyl salicylate decreased significantly. In Comparative Examples 7 and 8, the composition ratio of the film-forming agent was changed, and the contents of theaflavins, 6-methyl-5-hepten-2-one, and methyl salicylate also decreased.

[0151] 2. Brewing tests were conducted on the Jasmine No. 9 black tea from Examples 1-3 and Comparative Examples 1-8 respectively. The tea was brewed using a gaiwan (110mL gaiwan, 3g tea sample, boiling water). After brewing for 10, 20 and 30 times respectively, 20 professional testers evaluated the tea. The final result was determined by the unanimous choice of at least 16 professional testers for each item.

[0152] The results are shown in Table 2;

[0153] Table 2. Results of the brewing test

[0154]

[0155]

[0156] As shown in Table 1, the Jasmine No. 9 black tea prepared by the present invention has a lingering jasmine fragrance and a refreshing and sweet taste after being brewed 10, 20 and 30 times; and the refreshing and sweet taste is even better after brewing 30 times in Example 3.

[0157] In Comparative Example 1, after 10, 20, and 30 infusions, the aroma of regular tea was sweet and rich. After 30 infusions, the flavor was full-bodied but lacked a refreshing aroma.

[0158] The preparation methods of the mixed materials in Comparative Examples 2-5 were different. After brewing for 20 and 30 times, the fragrant and sweet taste of the tea decreased.

[0159] After 30 infusions in ratios 6-8, the tea's fresh, sweet flavor diminished.

[0160] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a fragrant and sweet jasmine black tea No. 9, characterized in that, Includes the following steps: (1) Weigh out fresh jasmine flowers and Yingjiu tea leaves; (2) Wash and dry the fresh jasmine flowers, and then remove the flowers to obtain the processed jasmine flowers. Then divide them into three parts, namely the first, second and third parts. (3) Mix the first batch of processed jasmine flowers with Yingjiu tea leaves and scent them to obtain a first batch of tea embryos; (4) The first batch of tea embryos and the second batch of processed jasmine flowers are scented at a mass ratio of 1:(0.18-0.22) to obtain the second batch of tea embryos; (5) The second batch of tea leaves and the third batch of processed jasmine flowers are scented at a mass ratio of 1:(0.08-0.12) to obtain the finished tea. The finished tea is then dried at a low temperature to obtain the fragrant and sweet Jasmine No. 9 black tea. The preparation method of Yinghong No. 9 tea includes the following steps: Step 1: Spread out fresh Yinghong No. 9 tea leaves to a thickness of 20cm. In spring, wither naturally for 4 hours, wither with heated air at 20℃ for 2 hours, wither naturally for 1 hour, and repeat this withering cycle for 14 hours. Step 2: Use a 50-type double-action rolling machine to first knead the leaves without air for 5 minutes, then knead them under pressure for 10 minutes. After kneading, add the tea leaves and film-forming agent together to a de-clumping machine to de-clump the leaves. The drum speed of the de-clumping machine is 500r / min, and the time is 10 minutes to obtain de-clumped leaves. Step 3: Place the de-clumped leaves in a fermentation chamber and add... The fermentation process involves: 100-200 U / g polyphenol oxidase and 50-100 U / g β-glucosidase from the unblocked tea leaves; a layer thickness of 6-10 cm for the unblocked leaves; maintaining an indoor temperature of 25-28℃ and a relative humidity of 96-98% for 8-12 hours; step four: frying the fermented tea leaves at 300℃ for 10 minutes, baking at 110℃ for 3 hours (leaving the leaves 2 cm thick), baking at 80℃ for 6 hours (leaving the leaves 2 cm thick); cooling to obtain Yingjiu tea; the mass ratio of the film-forming agent to the tea leaves is 3:

10. The film-forming agent is prepared by dissolving water-soluble chitosan, sodium alginate, and soy protein isolate in water; the mass ratio of water-soluble chitosan, sodium alginate, soy protein isolate, and water is (2-2.5):(1-1.5):1:

100. In step (3), a mixed material is added during the scenting process. The mass ratio of the mixed material, fresh jasmine flowers, and Yingjiu tea leaves is (0.04-0.06):(0.28-0.32):

1. The mixed material consists of the following raw materials in parts by mass: 13-17 parts of ginger, 25-30 parts of dried tangerine peel, 13-19 parts of osmanthus, 22-26 parts of rose, 23-27 parts of passion fruit, 0.5-1.2 parts of lychee, and 10-15 parts of magnolia. The preparation method of the mixed material includes the following steps: S1: Select ginger, dried tangerine peel, osmanthus, rose, and magnolia. After processing fragrant fruit, lychee, and magnolia, wash, remove the outer shell and kernel, dry, and pulverize to obtain a mixed powder; S2: Add water and glucose to the mixed powder, mix evenly, sterilize to obtain fermentation raw material, add microbial agent to the fermentation raw material, the microbial agent is composed of Lactobacillus plantarum, Bifidobacterium breve and Lactobacillus gasseri, the ratio of viable bacteria of Lactobacillus plantarum, Bifidobacterium breve and Lactobacillus gasseri in the microbial agent is 1:(0.3-0.5):(1.4-1.7), anaerobic fermentation for 3-5 days, sterilize after fermentation, filter, spray dry to obtain mixed material.

2. The method for preparing the fragrant and sweet Jasmine No. 9 black tea according to claim 1, characterized in that, In step (3), the scenting temperature is 35-45℃ and the scenting time is 18-24h.

3. The method for preparing the fragrant and sweet Jasmine No. 9 black tea according to claim 1, characterized in that, In step (4), the scenting temperature is 30-40℃ and the scenting time is 12-15h.

4. The method for preparing the fragrant and sweet Jasmine No. 9 black tea according to claim 1, characterized in that, In step (5), the scenting temperature is 25-40℃ and the scenting time is 12-15h.

5. A fragrant and sweet jasmine black tea No. 9 prepared by the preparation method according to any one of claims 1-4.

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