Golden flower Liupu tea and loose tea stable eurotium cristatum growing process thereof

Abstract

The invention relates to the technical field of tea processing, in particular to eurotium cristatum Liupu tea and a stable eurotium cristatum growing process of loose tea thereof. The loose tea stable eurotium cristatum growing process of the golden flower Liupu tea comprises the following steps: sequentially carrying out rehydration, eurotium cristatum inoculation, loose pressing and shaping and mold fermentation on raw tea to obtain a golden flower Liupu tea finished product; wherein steaming is carried out before inoculation of the eurotium cristatum or / and after loose pressing and shaping, the moisture content of the tea leaves during loose pressing and shaping is 25-30%, and a kraft paper layer with the specification of 100-180g / m < 2 > is adopted on the inner wall of a loose pressing and shaping mold to wrap the tea leaves. Kraft paper with a specific thickness is adopted in a mold for wrapping and shaping, and appropriate tea moisture content in a fermentation stage is combined, so that stable eurotium cristatum growing is realized, and the problems of low eurotium cristatum content and non-uniform eurotium cristatum growing effect in the eurotium cristatum Liupu tea finished product are remarkably improved; meanwhile, the eurotium cristatum growing time of the loose tea is obviously shortened.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, specifically to a golden flower Liubao tea and its stable flower-growing process in compressed tea. Background Technology

[0002] Liubao tea belongs to the dark tea category and is renowned for its four unique qualities: red color, strong flavor, aged quality, and mellow taste. Its traditional processing method uses fresh leaves from the Liubao tea tree as raw material. The raw tea undergoes a series of processes including withering, initial rolling, piling, re-rolling, and drying. This raw tea then undergoes sieving, blending, pile fermentation, steaming, drying, and pressing in baskets for aging (for more than 3 years) to obtain the finished tea. Long-aged Liubao tea often exhibits "golden flowers," scientifically known as *Eurotium cristatum*. This beneficial bacteria has health benefits such as promoting bowel movements, and Liubao tea with golden flowers possesses a unique sweet and mellow taste and the aroma of the fungus, making it distinctive among Liubao tea products. However, the traditional Liubao tea processing method cannot stably produce *Eurotium cristatum*. Therefore, achieving stable *Eurotium cristatum* development in Liubao tea is of great significance for enriching its quality characteristics, improving its quality, and increasing the economic benefits of the Liubao tea industry.

[0003] The development of "golden flowers" in Liubao tea mainly includes three methods: brick tea development, loose tea development, and basket tea development. Brick tea development is currently the most mature method on the market, with bricks typically in 500g and 1kg sizes and a thickness of 5-7cm. The success rate of brick tea development is relatively high. Loose tea development is more complex, requiring liquid seed cultivation followed by inoculation in a cleanroom below Class 10,000. This demands extremely high environmental standards and prolonged high-temperature sterilization of the tea leaves, resulting in significant equipment investment and high technical difficulty, but its success rate is generally over 99%. Currently, basket tea development can achieve partial development by controlling environmental temperature, humidity, and tea moisture content under specific conditions, but the effect is unpredictable and highly random, with a development rate of only around 60%. Furthermore, the low content of "golden flowers" and severe contamination by other microorganisms lead to a low yield. The average cultivation time exceeds two months, resulting in a long development cycle that limits the production of Liubao tea with "golden flowers." In addition, the tea basket usually requires more than 15 tons of pressure for compression. If it is compressed too tightly, the center of the basket will not be able to develop its characteristic bloom, resulting in uneven blooming.

[0004] The development of Liubao tea with golden flower bloom is currently restricted by defects such as unstable bloom rate, low golden flower content, long bloom cycle, and uneven bloom effect. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing Liubao Golden Flower Bamboo Tea, such as unstable flowering rate, low golden flower content, long flowering cycle and uneven flowering effect, so as to provide a Golden Flower Liubao Tea and its loosely compressed tea stable flowering process to solve the above problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a stable fermentation process for compressed Liubao tea with golden flower patterns, comprising:

[0008] The raw tea leaves are sequentially rehydrated, inoculated with *Eurotium cristatum*, loosely pressed and shaped, and fermented in a mold to obtain the finished Jin Hua Liu Bao tea. Among them, steaming is carried out before and / or after loosely pressed and shaped. The moisture content of the tea leaves during loosely pressed and shaped is 25-30%, and the tea leaves are wrapped in a layer of kraft paper with a specification of 100-180g / ㎡ on the inner wall of the mold for loosely pressed and shaped.

[0009] Preferably, the fermentation conditions are as follows: 20-25°C and 40-50% humidity for 1-3 days, 25-30°C and 45-55% humidity for 4-13 days, and 40-45°C and 30-40% humidity for 14-18 days.

[0010] Preferably, the raw tea is premium grade or / and first grade raw tea;

[0011] And / or, the moisture content of the rehydrated tea leaves is 20%-25%.

[0012] Preferably, before rehydration, impurities in the raw tea leaves are removed.

[0013] And / or, the *Eurotium cristatum* is steamed before inoculation and then cooled.

[0014] Preferably, the impurities include sand, yellow flakes, and tea buds with a diameter greater than 1 cm.

[0015] Preferably, during the cooling step, the thickness of the tea leaves is 10-50 cm;

[0016] And / or, the cooling time is 4-12 hours.

[0017] Preferably, the steam pressure of the steam is 2-4 kPa;

[0018] And / or, the steaming time for the tea is 60-120 seconds.

[0019] Preferably, after the fermentation step, the product is further demolded and dried for later use.

[0020] Preferably, the pressure for the loosening and shaping is 3 to 5 tons;

[0021] And / or, the duration of the pressure setting is 3-5 minutes.

[0022] Secondly, the present invention also provides a Golden Flower Liubao Tea, which is prepared by the above-mentioned loose-pressed tea stable fermentation process of Golden Flower Liubao Tea.

[0023] In the steaming process described in this invention, *Eurotium cristatum* has certain heat resistance properties, but bacteria and other molds have poor heat resistance properties. Based on this, steam only kills most of the miscellaneous bacteria, thereby reducing bacterial contamination.

[0024] In this invention, the definition of loose-pressure shaping is: placing tea leaves inoculated with *Aspergillus cristatus* into a mold that serves as a fixation agent, and applying pressure to the mold to shape it. Unlike existing pressing methods (15 tons of tight pressure, holding time of 1 minute), loose-pressure shaping involves lower pressure and a longer holding time.

[0025] Molds for loosening and shaping include, but are not limited to, disc-shaped, column-shaped, and basket-shaped molds.

[0026] After the tea leaves are released from pressure and shaped, they are fermented directly in the mold without being removed. That is, after the pressure is released, the tea leaves and the mold are placed together in the fermentation chamber to complete the fermentation process. This results in the tea leaves being loose but not falling apart, increasing the amount of "flowering" (a process of tea fermentation), reducing the risk of contamination, and better adapting to the fast-paced drinking habits of the market.

[0027] The moisture content refers to the percentage of the mass of water in a substance relative to its total mass.

[0028] The technical solution of this invention has the following advantages:

[0029] 1. A stable fermentation process for Jin Hua Liu Bao tea, comprising: rehydrating raw tea, inoculating with *Aspergillus cristatus*, loosely pressing and shaping, and fermenting in a mold to obtain the finished Jin Hua Liu Bao tea; wherein, steaming is performed before and / or after loosely pressing and shaping, the moisture content of the tea leaves during loosely pressing and shaping is 25-30%, and the tea leaves are wrapped in a layer of kraft paper with a specification of 100-180g / ㎡ on the inner wall of the mold during loosely pressing and shaping. To address the challenges of unstable blooming rate, low bloom content, long blooming cycle, and uneven blooming effect in Liubao Golden Flower Basket Tea, this invention creates a facultative anaerobic environment suitable for the growth of *Aspergillus cristatus* by wrapping the tea in a mold with a kraft paper layer of a specific thickness. Combined with appropriate moisture content in the tea leaves during fermentation, this not only ensures a blooming rate of over 99%, even 100%, achieving stable blooming in Liubao tea, but also significantly improves the low bloom content and uneven blooming effect in the finished product, thereby greatly enhancing the quality of Golden Flower Liubao tea. Furthermore, the stable blooming process of this invention significantly shortens the blooming time of Liubao tea, greatly improving the production efficiency of Golden Flower Liubao tea and solving the problem of long blooming cycles in traditional basket tea which restricts the yield of Golden Flower Liubao tea. Moreover, this process has undemanding blooming conditions and is easy to operate, requiring minimal investment in equipment and personnel, resulting in lower costs and high application and promotion value.

[0030] 2. In the stable fermentation process of Liubao tea with golden flower provided by the present invention, it is preferable to perform steaming treatment before inoculation with Eurotium cristatum and after loosening and shaping. Compared with single steaming, steaming before inoculation with Eurotium cristatum and after loosening and shaping can significantly increase the golden flower content in the finished Liubao tea and significantly reduce the contamination of miscellaneous bacteria, which can further improve the quality of Liubao tea with golden flower.

[0031] 3. In the stable fermentation process of Liubao tea with golden flower provided by the present invention, a three-stage fermentation condition control is adopted. Compared with constant condition fermentation, the golden flower content in the finished Liubao tea produced by the three-stage fermentation condition control provided by the present invention is significantly increased, and the contamination of miscellaneous bacteria is significantly reduced, thereby further improving the quality of Liubao tea with golden flower. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1This is a schematic diagram of the process for stabilizing the fermentation of Jinhua Liubao tea using compressed tea according to the present invention.

[0034] Figure 2 This is a photograph of the golden flower Liubao tea prepared according to Example 1 of the present invention;

[0035] Figure 3 This is a photograph of the Jinhua Liubao tea prepared in Comparative Example 1 of this invention. Detailed Implementation

[0036] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0037] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0038] In the following examples and comparative examples, the experimental (column-type, 30cm in diameter, height adjustable from 30-50cm) mold specifications are ≤12kg / mold. Specific specifications are shown in Table 1. The inoculation amount of *Aspergillus cristatus* (for flowering Liubao tea, equivalent to the mass of dry seeds) is 3wt% of the cooled tea leaves. The *Aspergillus cristatus* content in the inoculated flowering Liubao tea leaves is 2.1 × 10⁻⁶. 5 CFU / g. The steam pressure is between 2-4 kPa and the steam temperature is between 110-130℃.

[0039] Example 1

[0040] This embodiment provides a stable fermentation process for Jin Hua Liu Bao tea using compressed tea leaves. The process flow is as follows: Figure 1 As shown, the specific steps are as follows:

[0041] 1) Select first-grade raw tea as raw material, and perform preliminary refining of the raw material to remove impurities such as sand, yellow leaves and tea heads with a diameter greater than 1cm. Then rehydrate the tea to 20%.

[0042] 2) After rehydration, the tea leaves are steamed once for sterilization. The steam pressure of the first steaming is 3 kPa and the steaming time is 90 seconds. After steaming, the tea leaves are spread out to cool. The thickness of the tea leaves is 30 cm and the cooling time is 6 hours.

[0043] 3) After the tea leaves have cooled, add golden flower seeds and mix well. Then, wrap a layer of kraft paper with a specification of 180g / ㎡ on the inner wall of the mold for loose pressing and shaping. Five parallel tests were conducted according to the specification of 10kg / mold. The tea leaves were automatically filled into the mold for loose pressing and shaping by the equipment, and then the machine was pressed and shaped for 3 minutes under a pressure of 5 tons. The inoculation amount of *Aspergillus cristatus* was 3wt%, and the moisture content of the tea leaves during loose pressing and shaping was 25.64%.

[0044] 4) Place the entire pressed tea column, along with the mold, into the tea steaming box for a second steaming. The steam pressure for the second steaming is 3 kPa, and the steaming time for the second steaming is 90 seconds.

[0045] 5) The tea leaves, after secondary steaming, are fermented in molds under the following conditions: 23℃ and 50% humidity for 1-3 days; 30℃ and 55% humidity for 4-13 days; and 40℃ and 40% humidity for 14-18 days, at which point fermentation is terminated. A photograph of the fermented Jin Hua Liu Bao tea from this embodiment is shown below. Figure 2 As shown in Table 1, the test results of its golden flower content are as follows;

[0046] 6) Remove the fermented tea leaves from the mold and place them in a well-ventilated and dry place to dry for later use.

[0047] Example 2

[0048] This embodiment provides a stable fermentation process for Jin Hua Liu Bao tea using compressed tea leaves. The process flow is as follows: Figure 1 As shown, the specific steps are as follows:

[0049] 1) Select first-grade raw tea as raw material, and perform preliminary refining of the raw material to remove impurities such as sand, yellow leaves and tea heads with a diameter greater than 1cm. Then rehydrate the tea to 25%.

[0050] 2) After rehydration, the tea leaves are steamed once for sterilization. The steam pressure of the first steaming is 2 kPa and the steaming time is 120 seconds. After steaming, the tea leaves are spread out to cool. The thickness of the tea leaves is 10 cm and the cooling time is 4 hours.

[0051] 3) After the tea leaves have cooled, add golden flower seeds and mix well. Wrap a layer of kraft paper with a specification of 180g / ㎡ on the inner wall of the mold for loose pressing and shaping. Conduct 5 parallel tests according to the specification of 10kg / mold. The tea leaves obtained in step 3) are automatically filled into the mold for loose pressing and shaping by the equipment. Then, the tea leaves are shaped under 3 tons of pressure for 5 minutes. The inoculation amount of *Aspergillus cristatus* is 3wt%, and the moisture content of the tea leaves during loose pressing and shaping is 29.34%.

[0052] 4) Place the entire pressed tea column, along with the mold, into the tea steaming box for a second steaming. The steam pressure for the second steaming is 4 kPa, and the steaming time for the second steaming is 60 seconds.

[0053] 5) The tea leaves after the second steaming were fermented in molds. The fermentation conditions were as follows: 25℃ and 40% for 1-3 days, 26℃ and 45% for 4-13 days, and 45℃ and 30% for 14-18 days. Fermentation was then terminated. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this embodiment are shown in Table 1.

[0054] 6) Remove the fermented tea leaves from the mold and place them in a well-ventilated and dry place to dry for later use.

[0055] Example 3

[0056] This embodiment provides a stable fermentation process for Jin Hua Liu Bao tea using compressed tea leaves. The process flow is as follows: Figure 1 As shown, the specific steps are as follows:

[0057] 1) Select first-grade raw tea as raw material, and perform preliminary refining of the raw material to remove impurities such as sand, yellow leaves and tea heads with a diameter greater than 1cm. Then rehydrate the tea to 22%.

[0058] 2) After rehydration, the tea leaves are steamed once for sterilization. The steam pressure of the first steaming is 4 kPa and the steaming time is 60 seconds. After steaming, the tea leaves are spread out to cool. The thickness of the tea leaves is 50 cm and the cooling time is 12 hours.

[0059] 3) After the tea leaves have cooled, add golden flower seeds and mix well. Wrap a layer of 180g / ㎡ kraft paper on the inner wall of the mold for loose pressing and shaping. Conduct 5 parallel tests according to the specification of 10kg / mold. Manually fill the tea leaves obtained in step 3) into the mold for loose pressing and shaping, and then put them on the machine to be shaped under 5 tons of pressure for 3 minutes. The inoculation amount of *Aspergillus cristatus* is 3wt%, and the moisture content of the tea leaves during loose pressing and shaping is 26.9%.

[0060] 4) Place the pressed tea column with the mold into the tea steaming box for a second steaming. The steam pressure of the second steaming is 2 kPa and the steaming time is 120 seconds.

[0061] 5) The tea leaves after the second steaming were fermented in molds. The fermentation conditions were as follows: 20℃ and 50% for 1-3 days, 25℃ and 55% for 4-13 days, and 45℃ and 40% for 14-18 days. Fermentation was then terminated. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this embodiment are shown in Table 1.

[0062] 6) Remove the fermented tea leaves from the mold and place them in a well-ventilated and dry place to dry for later use.

[0063] Example 4

[0064] The difference between this embodiment and Embodiment 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 28.3%, while other conditions were the same as in Embodiment 1. The test results of the golden flower content of the fermented golden flower Liubao tea in this embodiment are shown in Table 1.

[0065] Example 5

[0066] The difference between this embodiment and Embodiment 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 27.64%, while other conditions were the same as in Embodiment 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this embodiment are shown in Table 1.

[0067] Example 6

[0068] The difference between this embodiment and Embodiment 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 26.51%. A layer of 100g / ㎡ kraft paper was wrapped around the inner wall of the mold, and a 12kg mold was used for the experiment. Other conditions were the same as in Embodiment 1. The test results of the golden flower content of the fermented golden flower Liubao tea in this embodiment are shown in Table 1.

[0069] Example 7

[0070] The difference between this embodiment and embodiment 6 is that the actual moisture content of the tea leaves during the loosening and pressing process was 26.65%, and a layer of kraft paper with a specification of 150g / ㎡ was wrapped around the inner wall of the mold. Other conditions were the same as in embodiment 5. The test results of the golden flower content of the fermented golden flower Liubao tea in this embodiment are shown in Table 1.

[0071] Example 8

[0072] The difference between this embodiment and embodiment 6 is that the actual moisture content of the tea leaves during the loosening and pressing process was 26.43%, and a layer of kraft paper with a specification of 180g / ㎡ was wrapped around the inner wall of the mold. Other conditions were the same as in embodiment 5. The test results of the golden flower content of the fermented golden flower Liubao tea in this embodiment are shown in Table 1.

[0073] Example 9

[0074] The difference between this comparative example and Example 1 is that golden flower seeds were added to the tea leaves after rehydration and mixed well. The mixture was then steamed for 3 minutes under a steam pressure of 3 kPa. After steaming, the tea leaves were directly loosened and shaped. The actual moisture content of the tea leaves during loosening and shaping was 25.61%. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented golden flower Liubao tea in this example are shown in Table 1.

[0075] Example 10

[0076] The difference between this comparative example and Example 1 is that the rehydrated tea leaves were steamed for 3 minutes under a steam pressure of 3 kPa, then cooled to a thickness of 30 cm for 6 hours. After cooling, golden flower seeds were added and mixed well, and then loosely pressed and shaped. The actual moisture content of the tea leaves during loose pressing and shaping was 25.49%. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Liubao tea in this example are shown in Table 1.

[0077] Example 11

[0078] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the pressing and shaping process was 25.51%, and the fermentation conditions were: a constant temperature of 30°C and a constant humidity of 50% for 1-18 days, with other conditions being the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this example are shown in Table 1.

[0079] Example 12

[0080] The difference between this embodiment and Embodiment 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 25.72%, and a 1kg mold was used for the experiment. Other conditions were the same as in Embodiment 1. The test results of the golden flower content of the fermented golden flower Liubao tea in this embodiment are shown in Table 1.

[0081] Example 13

[0082] The difference between this embodiment and Embodiment 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 25.61%, and a 4kg mold was used for the experiment. Other conditions were the same as in Embodiment 1. The test results of the golden flower content of the fermented golden flower Liubao tea in this embodiment are shown in Table 1.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 23.76%. Other conditions were the same as in Example 1. A picture of the fermented Jin Hua Liu Bao tea from this comparative example is shown below. Figure 3 As shown in Table 1, the test results of its golden flower content are as follows.

[0085] Comparative Example 2

[0086] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 32.07%, while other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0087] Comparative Example 3

[0088] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the pressing and shaping process was 25.65%, and the mold was not lined with a kraft paper bag. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Jin Hua Liu Bao tea in this comparative example are shown in Table 1.

[0089] Comparative Example 4

[0090] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 25.68%, a PP plastic bucket was used as the container, the bucket lid had ventilation holes to create a semi-sealed environment, and the mold was not lined with a kraft paper bag. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 25.46%, the mold was lined with a cloth bag, and other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0093] Comparative Example 6

[0094] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the pressing and shaping process was 25.43%, and the mold was lined with a white cotton paper bag. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented golden flower Liubao tea in this comparative example are shown in Table 1.

[0095] Comparative Example 7

[0096] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the pressing and shaping process was 25.71%, and a layer of kraft paper with a specification of 50g / ㎡ was wrapped around the inner wall of the mold. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0097] Comparative Example 8

[0098] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the loosening and pressing process was 25.33%, and a layer of 230g / ㎡ kraft paper was wrapped around the mold wall. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0099] Comparative Example 9

[0100] The difference between this comparative example and Example 1 is that the loose pressing was replaced with tight pressing (15 tons of tight pressing, holding time 1 minute). The actual moisture content of the tea leaves during loose pressing was 25.57%. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0101] Comparative Example 10

[0102] The difference between this comparative example and Example 1 is that the actual moisture content of the tea leaves during the loosening and shaping process was 25.30%, and fermentation was carried out without a mold. Other conditions were the same as in Example 1. The test results of the golden flower content of the fermented Golden Flower Liubao tea in this comparative example are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] In this invention, the main testing steps for the content of *Aspergillus cristatus* are as follows: Prepare the sample into 10-fold serial dilutions, select three appropriate dilutions, pipette 1 ml into a petri dish, add PDA medium, incubate and observe for 6-7 days, and then count the bacteria. The specific detection method is as follows:

[0111] 1) Sample pretreatment: Take 500g of Liubao flower tea sample, mix it evenly, take 100g and pulverize it aseptically (without sieving), the particle size is controlled below 60 mesh, and collect the pulverized tea sample for later use.

[0112] 2) Spore elution: After mixing the crushed tea sample evenly, accurately weigh 25g±0.1g and place it in a 500ml sterile Erlenmeyer flask. Accurately measure 225ml of sterile water and add it to the Erlenmeyer flask containing the tea sample. Place the flask in a shaker and elute. Set the shaker speed to 130r / min and the time to 30min. This is a 10-fold elution stock solution.

[0113] 3) Preparation of gradient dilution buffer: Accurately pipette 1 ml of the elution stock solution into a 20 ml graduated test tube, add 9 ml of sterile water, vortex to mix, and prepare a 10% gradient dilution buffer. -1 Diluted solutions were prepared in this manner, and 10 times diluted solutions were prepared accordingly. -2 10 -3 10 -4 10 -5 Diluent is available for later use;

[0114] 4) Selection of culture medium: Potato-dextrose-agar (PDA) medium was selected, and the culture medium was prepared according to the culture medium preparation instructions;

[0115] 5) Pour culture: Select 3 suitable dilutions for each sample (currently, the laboratory uses 10). -4 10 -5 10 -6 Three dilution factors), pour 3 petri dishes for each dilution, cool the culture medium to 45°C after it melts, pour it immediately and rotate to mix, after the culture medium solidifies, turn the petri dishes over and put them into the incubator for incubation.

[0116] 6) Culture conditions: Culture temperature: 28℃, humidity has no special requirements. After 4 days of culture, the colonies of *Aspergillus cristatus* begin to grow. After 6-7 days, the colonies turn from yellow to brown, and counting begins. Record the results.

[0117] 7) Colony Count: Select plates with colony counts between 10 and 50 for counting. Use three plates for each dilution, and take the average colony count of each plate, multiplying it by the dilution factor for reporting. The sample is reported in grams. The formula for calculating the colony count is: Colony Count = Reading × Dilution Factor × 10 CFU / g.

[0118] As shown in Table 1, compared to Comparative Examples 1-10, all the loosely pressed Liubao teas in Examples 1-13 were able to achieve stable flowering, and the golden flowers were abundant with a content of *Aspergillus cristatus* exceeding 5 × 10⁻⁶. 5 CFU / g. Secondly, compared with Examples 9 and 10 which used single steaming and Example 11 which used constant-condition fermentation, the contamination of miscellaneous bacteria and the content of *Aspergillus cristatus* in Examples 1-8, which used double steaming and three-stage controlled fermentation, were significantly improved.

[0119] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A process for stable flowering of loose-pressed tea of ​​Jinhua Liubao tea, characterized in that: include: The raw tea is sequentially subjected to rehydration, inoculation with Eurotium cristatum, loosening and pressing to shape, and fermentation with a mold to obtain the finished Jinhua Liubao tea; wherein, steaming is performed before the inoculation with Eurotium cristatum and / or after loosening and pressing to shape, the moisture content of the tea during the loosening and pressing to shape is 25-30%, and the tea is wrapped with a kraft paper layer with a specification of 100-180g / ㎡ on the inner wall of the mold for loosening and pressing to shape.

2. The stable flowering process of loose pressed tea according to claim 1, characterized in that: The fermentation conditions are as follows: the temperature is 20-25°C and the humidity is 40-50% during 1-3 days, the temperature is 25-30°C and the humidity is 45-55% during 4-13 days, and the temperature is 40-45°C and the humidity is 30-40% during 14-18 days.

3. The stable flowering process of loose pressed tea according to claim 1 or 2, characterized in that: The raw tea is special grade or / and first grade raw tea; And / or, the moisture content of the tea leaves after rehydration is 20%-25%.

4. The stable flowering process of loose pressed tea according to any one of claims 1 to 3, characterized in that: Before the rehydration, impurities in the raw tea are picked out; And / or, the Eurotium cristatum is steamed before inoculation and then spread out to cool.

5. The stable flowering process of loose pressed tea according to claim 4, characterized in that: The impurities include sand, yellow flakes and tea leaves with a diameter greater than 1 cm.

6. The stable flowering process of loose pressed tea according to claim 4 or 5, characterized in that: In the cooling step, the thickness of the tea leaves is 10-50 cm; And / or, the cooling time is 4-12 hours.

7. The stable flowering process of loose pressed tea according to any one of claims 1 to 6, characterized in that: The steam pressure of the steaming is 2-4 kPa; And / or, the steaming time of the tea is 60-120s.

8. The stable flowering process of loose pressed tea according to any one of claims 1 to 7, characterized in that: After the fermentation step, demoulding and air-drying are performed for later use.

9. The stable flowering process of loose pressed tea according to claim 8, characterized in that: The pressure of the loosening and shaping is 3 tons to 5 tons; And / or, the duration of the loosening, pressing and shaping is 3-5 minutes.

10. A Jinhua Liubao tea, characterized in that: The tea is prepared by the stable flowering process of the loose-pressed Jinhua Liubao tea described in any one of claims 1 to 9.

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