A jinhuanghuangjian pu'er tea, a preparation method and application thereof

Abstract

The present application relates to a kind of gold flowered rhizoma polygonati pu'er tea and its preparation method and application, the preparation method includes: rhizoma polygonati raw material is mixed with water and is refluxed extraction, filtration, and rhizoma polygonati extract liquid is obtained;It is mixed with Yunnan large leaf species sun-cured green tea and microwave sterilization treatment;Crown protruding sporocarpi strain is inoculated in the above product and is fermented;After fermentation, drying treatment is carried out, and it is obtained.The rhizoma polygonati extract liquid prepared by water extraction method is mixed with Yunnan large leaf species sun-cured green tea and is combined fermentation, rhizoma polygonati extract liquid can provide nutrient material for Eurotium cristatum, and can effectively inhibit the growth and reproduction of bacteria and various bacteria, ensure the quality and quantity of Eurotium cristatum dominant flora in pu'er tea, and combined microwave sterilization retains the nutritional ingredients and efficacy ingredients in pu'er tea, and the gold flowered rhizoma polygonati pu'er tea prepared is good in taste, strong in fragrance, and bright in soup color;Rhizoma polygonati extract liquid and tea can synergistically enhance the efficacy of antioxidation and anti-aging.

Description

Technical Field

[0001] This invention belongs to the field of tea processing technology, and relates to a golden flower polygonatum Pu-erh tea, its preparation method and application, specifically to a golden flower polygonatum Pu-erh tea with a bright golden-yellow color, rich and lasting aroma, mellow taste, and stronger antioxidant activity, as well as its preparation method and application. Background Technology

[0002] "Golden Flower," commonly known as "Golden Flower Fungus," scientifically named *Eurotium cristatum*, is a beneficial enzyme-producing bacterium that secretes various extracellular enzymes to catalyze the fermentation of tea leaves, improving their coarse and aged flavor, reducing bitterness, and enhancing their biological activity. Through modern processing techniques, *Eurotium cristatum* has become a beneficial bacterium in some dark teas, and its quantity and quality directly affect the quality of the tea. For example, the local standards for Jingyang Fucha in Shaanxi and Anhua Dark Tea in Hunan both list the quantity of *Eurotium cristatum* as a key quality standard.

[0003] Pu-erh tea is made from fresh leaves of the Yunnan large-leaf variety using specific processing techniques. Pu-erh tea has a brownish-red appearance, a bright reddish-brown liquor, a sweet aftertaste, and a rich, mellow aroma. Its abundant polyphenols provide excellent antioxidant and anti-aging benefits, while also offering advantages such as clearing heat and detoxifying, lowering blood sugar and reducing fat, refreshing the mind, and warming the stomach. Long-term consumption is beneficial to health. Because *Aspergillus cristatus* is not a dominant microorganism during the post-fermentation process of Pu-erh tea, it rarely appears. However, research has found that aged Pu-erh tea with *Aspergillus cristatus* has a sweeter, smoother, and more refreshing taste, a brighter reddish-brown liquor, and a higher nutrient content. It also eliminates the raw, grassy taste and the musty or musty smell produced during fermentation. Therefore, making *Aspergillus cristatus* the dominant microorganism during tea fermentation and selectively inhibiting the growth of other miscellaneous microorganisms is a key technical challenge in producing high-quality Pu-erh tea with *Aspergillus cristatus*.

[0004] Patents CN102217688A, CN108514038A, and CN103283885A disclose the selective addition of exogenous strains to ferment Pu-erh tea, thereby achieving the "flowering" of Pu-erh tea and producing "golden flower" Pu-erh tea, but without controlling the growth of other miscellaneous bacteria. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a Golden Flower Polygonatum Pu-erh tea, its preparation method, and its application. Specifically, it provides a Golden Flower Polygonatum Pu-erh tea with a bright golden-yellow liquor, a rich and lasting aroma, a mellow taste, and stronger antioxidant activity, as well as its preparation method and application.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing Polygonatum odoratum Pu-erh tea, the method comprising:

[0008] (1) Mix the raw material of Polygonatum with water and reflux extract, filter, and obtain Polygonatum extract;

[0009] (2) Mix the extract of Polygonatum sibiricum with sun-dried green tea of ​​Yunnan large-leaf variety and sterilize it with microwave.

[0010] (3) Inoculate the product from step (2) with the *Eurotium cristatum* strain and ferment it.

[0011] (4) After fermentation, the tea is dried to obtain the Golden Flower Polygonatum Pu-erh Tea.

[0012] This invention creatively combines a Polygonatum extract obtained through water extraction with Yunnan large-leaf sun-dried green tea for co-fermentation. The Polygonatum extract not only provides nutrients for *Aspergillus cristatus* but also effectively inhibits the growth and reproduction of bacteria and various pathogens, ensuring the quality and quantity of the dominant *Aspergillus cristatus* flora in Pu-erh tea, with the *Aspergillus cristatus* count reaching 1×10⁻⁶. 7 The bacterial count is above 100% per gram of tea. Furthermore, the combined microwave sterilization preserves the nutrients and functional components of Pu-erh tea, resulting in a Pu-erh tea with golden flower polygonatum that boasts a superior taste, rich aroma, and bright color, while also enhancing the health benefits of Pu-erh tea. Simultaneously, the polygonatum extract and tea have a synergistic effect in their antioxidant and anti-aging properties, and the extract is superior to the polygonatum raw material itself in achieving these effects. This preparation process expands the application of polygonatum in functional foods and cosmetics, and is of great significance for the technological innovation and application of golden flower polygonatum Pu-erh tea.

[0013] Preferably, the raw material of Polygonatum is selected from any one or a combination of at least two of Polygonatum sibiricum, Polygonatum multiflorum, Polygonatum yunnanense, Polygonatum jellyfishii, or Polygonatum scabra, with Polygonatum yunnanense being the preferred choice.

[0014] Compared to other types of Polygonatum, using Polygonatum yunnanense as the raw material can further improve the quality and quantity of the dominant flora of Aspergillus cristatus in Pu-erh tea. The resulting Polygonatum yunnanense Pu-erh tea has advantages in taste, appearance, aroma, liquor color and flavor, and also has advantages in antioxidant effects.

[0015] Preferably, the Polygonatum sibiricum raw material is pulverized before being mixed with water.

[0016] Preferably, the mass ratio of the Polygonatum odoratum raw material to water is 1:(8-12), such as 1:8, 1:9, 1:10, 1:11, 1:12, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0017] Preferably, the reflux extraction time is 1-3 hours, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0018] Preferably, the mass ratio of Yunnan large-leaf sun-dried green tea to Polygonatum sibiricum raw material is (10-45):1, for example, 10:1, 11:1, 13:1, 16:1, 20:1, 22:1, 25:1, 30:1, 35:1, 40:1, 45:1, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0019] Preferably, the water content in the mixing system of step (2) is 30-50% of the mass of Yunnan large-leaf sun-dried green tea, such as 30%, 33%, 35%, 37%, 40%, 43%, 45%, 48%, 50%, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0020] In step (2), the relative content of water to tea leaves in the mixed system is specifically chosen to be in the range of 30-50% because if the amount of water used to soften the tea leaves is too low, the tea leaves will have a burnt taste, insufficient microwave permeability, and a large number of miscellaneous bacteria; if the amount of water is too high, it will not be conducive to subsequent fermentation.

[0021] Preferably, the frequency of the microwave sterilization process is 1000-3000MHz, such as 1000MHz, 1500MHz, 2000MHz, 2500MHz, 3000MHz, etc.; the sterilization time is 60-90s, such as 60s, 65s, 70s, 75s, 80s, 85s, 90s, etc. Other specific values ​​within the above range can be selected, and will not be elaborated here.

[0022] Traditional sun-dried green tea fermentation typically employs high-temperature steam sterilization, resulting in significant loss of nutrients and active ingredients. Compared to high-temperature steam sterilization, microwave sterilization offers advantages such as rapid and uniform heating, energy efficiency, safety, and good penetration. Microwave sterilization greatly reduces the heating time of tea leaves, which is beneficial for preserving nutrients and flavor compounds. Furthermore, it can deactivate enzymes such as polyphenol oxidase in tea leaves. Excessive microwave treatment time can damage flavor and nutrients, while insufficient time leads to poor sterilization. A sterilization time of 60-90 seconds is optimal.

[0023] Preferably, the inoculation amount of the *Aspergillus cristatus* strain is 0.1-1% of the Yunnan large-leaf sun-dried green tea, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc. Other specific values ​​within this range can be selected, and will not be elaborated here.

[0024] Preferably, the fermentation adopts a staged variable-temperature fermentation method, specifically: First stage fermentation: temperature 23-27℃ (e.g., 23℃, 24℃, 25℃, 26℃, 27℃, etc.), humidity 75-86% (e.g., 75%, 77%, 78%, 79%, 80%, 82%, 83%, 85%, 86%, etc.), time 2-4 days (e.g., 2 days, 2.5 days, 3 days, 3.5 days, 4 days, etc.); Second stage fermentation: temperature 33-37℃ (e.g., 33℃, 34℃, 35℃, 36℃, 37℃, etc.), humidity 60-75%. (e.g., 60%, 62%, 65%, 67%, 68%, 69%, 70%, 73%, 75%, etc.), time 3-6 days (e.g., 3 days, 3.5 days, 4 days, 4.5 days, 5 days, 6 days, etc.); third stage fermentation: temperature 25-30℃ (e.g., 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, etc.), humidity 55-65% (e.g., 55%, 57%, 58%, 59%, 60%, 63%, 65%, etc.), time 3-6 days (e.g., 3 days, 3.5 days, 4 days, 4.5 days, 5 days, 6 days, etc.).

[0025] Other specific point values ​​within the above range can be selected, and will not be elaborated on here.

[0026] This invention employs a specific three-stage fermentation process. Each stage of fermentation meets specific temperature, humidity, and time ranges. In the initial stage, a lower temperature and higher humidity are selected to promote spore germination and inhibit the growth of thermophilic bacteria. During the middle stage, as the moisture content of the tea leaves decreases, *Aspergillus cristatus* mycelium enters its growth phase, and noticeable golden spores can be observed on the tea leaves. The increased temperature ensures an optimal environment for *Aspergillus cristatus* while inhibiting the growth of moisture-loving *Aspergillus niger* and thermophilic *Penicillium*. In the later stage, the golden spores have essentially covered the tea leaves. Lowering the culture temperature slows down the metabolism of the mycelium during this later stage, which is conducive to the formation of sexual spores from *Aspergillus cristatus* cleistothecia. This simulates the temperature and humidity conditions under natural conditions, facilitating better storage under natural conditions after fermentation. Furthermore, the rich nutrients in the *Polygonatum sibiricum* extract maintain the abundance of golden spores on the tea leaf surface, resulting in a uniform, golden-yellow color covered with the abundant golden spores.

[0027] Preferably, the drying process is carried out at 40-50℃ (e.g., 40℃, 42℃, 43℃, 45℃, 47℃, 48℃, 50℃, etc.).

[0028] Preferably, the endpoint of the drying process is that the moisture content of the Jin Hua Huang Jing Pu Er tea is controlled at 8%-14%, such as 8%, 9%, 10%, 11%, 12%, 13%, 14%, etc.

[0029] Other specific point values ​​within the above range can be selected, and will not be elaborated on here.

[0030] Secondly, the present invention provides a golden flower polygonatum Pu-erh tea, which is prepared by the preparation method described in the first aspect.

[0031] The Golden Flower Polygonatum Pu-erh Tea has a bright golden-yellow liquor, a rich and lasting aroma, and a mellow taste. The water extract of the Golden Flower Polygonatum Pu-erh Tea has strong antioxidant activity and can be used in functional foods and cosmetics.

[0032] Preferably, the product form of the Golden Flower Polygonatum Pu-erh Tea is any one of loose tea, tea cake, brick tea, tuocha, or thin slices.

[0033] Thirdly, the present invention provides the application of the aqueous extract of Polygonatum odoratum Pu-erh tea according to the second aspect in the preparation of functional foods or cosmetics.

[0034] Fourthly, the present invention provides the use of the aqueous extract of Polygonatum odoratum Pu-erh tea according to the second aspect in the preparation of food or cosmetics with antioxidant effects.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] This invention creatively combines a Polygonatum extract obtained through water extraction with Yunnan large-leaf sun-dried green tea for co-fermentation. The Polygonatum extract not only provides nutrients for *Aspergillus cristatus* but also effectively inhibits the growth and reproduction of bacteria and various pathogens, ensuring the quality and quantity of the dominant *Aspergillus cristatus* flora in Pu-erh tea, with the *Aspergillus cristatus* count reaching 1×10⁻⁶. 7 The bacterial count is above 100% per gram of tea. Furthermore, the combined microwave sterilization preserves the nutrients and functional components of Pu-erh tea, resulting in a Pu-erh tea with golden flower polygonatum that boasts a superior taste, rich aroma, and bright color, while also enhancing the health benefits of Pu-erh tea. Simultaneously, the polygonatum extract and tea have a synergistic effect in their antioxidant and anti-aging properties, and the extract is superior to the polygonatum raw material itself in achieving these effects. This preparation process expands the application of polygonatum in functional foods and cosmetics, and is of great significance for the technological innovation and application of golden flower polygonatum Pu-erh tea. Attached Figure Description

[0037] Figure 1 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 1;

[0038] Figure 2 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 2;

[0039] Figure 3 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 3;

[0040] Figure 4 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 4;

[0041] Figure 5 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 5;

[0042] Figure 6 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 6;

[0043] Figure 7 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 7;

[0044] Figure 8 This is an image of the appearance of the Polygonatum odoratum Pu-erh tea prepared in Example 8;

[0045] Figure 9 This is an image of the appearance of the Golden Flower Polygonatum Pu-erh Tea prepared in Comparative Example 1;

[0046] Figure 10 This is an image of the appearance of the Golden Flower Polygonatum Pu-erh Tea prepared in Comparative Example 2;

[0047] Figure 11 This is an image of the appearance of the Golden Flower Polygonatum Pu-erh Tea prepared according to ratio 3;

[0048] Figure 12 This is an image of the appearance of the Golden Flower Polygonatum Pu-erh Tea prepared according to ratio 4;

[0049] Figure 13 This is a picture of the appearance of Pu-erh tea made at ratio 5. Detailed Implementation

[0050] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0051] The *Aurorus cristatus* strain used in the following content is the strain with accession number CGMCC No. 3.2167, purchased from Beijing Beina Chuanglian Biotechnology Research Institute.

[0052] Example 1

[0053] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which is as follows:

[0054] (1) Take 10g of Polygonatum yunnanense medicinal material, crush it through a 50-mesh sieve, add 10 times the weight of purified water, heat and reflux for 2 hours, filter to remove the residue to obtain Polygonatum yunnanense extract, and cool for later use.

[0055] (2) Take 50g of Yunnan large-leaf sun-dried green tea, spray 20g of Polygonatum extract to soften the tea leaves, and microwave at 2450MHz for 60s for later use.

[0056] (3) Take the *Aspergillus cristatus* strain and inoculate it into the softened tea leaves. The inoculation amount is 0.5% of the raw Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the first 3 days of fermentation, control the fermentation temperature at 25℃ and the humidity at 85%. During the middle 6 days of fermentation, control the fermentation temperature at 35℃ and the humidity at 75%. During the last 5 days of fermentation, control the fermentation temperature at 28℃ and the humidity at 60%.

[0057] (4) After fermentation, dry at 45℃ until the moisture content is 12% to obtain Golden Flower Polygonatum Pu-erh Tea, which has the appearance of... Figure 1 As shown.

[0058] Example 2

[0059] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which is as follows:

[0060] (1) Take 10g of Polygonatum yunnanense medicinal material, crush it through a 50-mesh sieve, add 12 times the weight of purified water, heat and reflux for 3 hours, filter to remove the residue to obtain Polygonatum yunnanense extract, and cool for later use.

[0061] (2) Take 50g of Yunnan large-leaf sun-dried green tea, spray it with 22.5g of Polygonatum extract to soften the tea leaves, and microwave it at 2000MHz for 90s for later use.

[0062] (3) Take the *Aspergillus cristatus* strain and inoculate it into the softened tea leaves. The inoculation amount is 0.7% of the raw Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the initial fermentation period of 4 days, control the fermentation temperature at 27℃ and the humidity at 80%. During the middle fermentation period of 5 days, control the fermentation temperature at 37℃ and the humidity at 70%. During the later fermentation period of 4 days, control the fermentation temperature at 30℃ and the humidity at 65%.

[0063] (4) After fermentation, dry at 48℃ until the moisture content is 10% to obtain Golden Flower Polygonatum Pu-erh Tea, which has the appearance of... Figure 2 As shown.

[0064] Example 3

[0065] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which is as follows:

[0066] (1) Take 10g of Polygonatum yunnanense medicinal material, crush it through a 50-mesh sieve, add 8 times the weight of purified water, heat and reflux for 2 hours, filter to remove the residue to obtain Polygonatum yunnanense extract, and cool for later use.

[0067] (2) Take 50g of Yunnan large-leaf sun-dried green tea, spray 15g of Polygonatum extract to soften the tea leaves, and microwave at 1500MHz for 90s for later use.

[0068] (3) Take the *Aspergillus cristatus* strain and inoculate it into the softened tea leaves. The inoculation amount is 0.3% of the raw Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the initial fermentation period of 4 days, control the fermentation temperature at 24℃ and the humidity at 75%. During the middle fermentation period of 4 days, control the fermentation temperature at 35℃ and the humidity at 65%. During the later fermentation period of 5 days, control the fermentation temperature at 25℃ and the humidity at 55%.

[0069] (4) After fermentation, dry at 43℃ until the moisture content is 11% to obtain Golden Flower Polygonatum Pu-erh Tea, which has the appearance of... Figure 3 As shown.

[0070] Example 4

[0071] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which differs from that of Embodiment 1 only in the fermentation method of step (3): (3) Take the Aspergillus cristatus strain and inoculate it into the softened tea leaves and mix thoroughly. The inoculation amount is 0.5% of the raw material Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation; use constant temperature fermentation for 14 days, with constant temperature conditions of 28℃ and humidity of 65%. All other conditions remain unchanged, and its appearance is as follows. Figure 4 As shown.

[0072] Example 5

[0073] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which differs from that of Embodiment 1 only in the fermentation method of step (3): (3) Take the Aspergillus cristatus strain and inoculate it into the softened tea leaves and mix thoroughly. The inoculation amount is 0.5% of the raw material Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the initial 5 days of fermentation, control the fermentation temperature at 30℃ and the humidity at 85%. During the middle 8 days of fermentation, control the fermentation temperature at 35℃ and the humidity at 75%. During the later 5 days of fermentation, control the fermentation temperature at 35℃ and the humidity at 60%. All other conditions remain unchanged. Its appearance is as follows. Figure 5 As shown.

[0074] Example 6

[0075] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which differs from that of Embodiment 1 only in the fermentation method of step (3): (3) Take the Aspergillus cristatus strain and inoculate it into the softened tea leaves and mix thoroughly. The inoculation amount is 0.5% of the raw material Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the initial 3 days of fermentation, control the fermentation temperature at 25℃ and the humidity at 70%; during the middle 6 days of fermentation, control the fermentation temperature at 35℃ and the humidity at 55%; during the later 5 days of fermentation, control the fermentation temperature at 28℃ and the humidity at 50%. All other conditions remain unchanged, and its appearance is as follows. Figure 6 As shown.

[0076] Example 7

[0077] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which differs from that of Embodiment 1 only in that the microwave treatment at a frequency of 2450MHz for 60s in step (2) is replaced by microwave treatment at a frequency of 2450MHz for 110s. Its appearance is as follows. Figure 7 As shown.

[0078] Example 8

[0079] This embodiment provides a Golden Flower Polygonatum Pu-erh Tea, the preparation method of which differs from that of Embodiment 1 only in that the microwave treatment at a frequency of 2450MHz for 60s in step (2) is replaced with microwave treatment at a frequency of 2450MHz for 50s. Its appearance is as follows... Figure 8 As shown.

[0080] Comparative Example 1

[0081] This comparative example provides a Golden Flower Polygonatum Pu-erh tea, the preparation method of which differs from that of Example 1 only in that: in step (2), the microwave treatment at 2450MHz for 60s is replaced by high-pressure steam sterilization at 121℃ for 20min. All other conditions remain unchanged, and its appearance is as follows. Figure 9 As shown.

[0082] Comparative Example 2

[0083] This comparative example provides a Polygonatum odoratum Pu-erh tea, the preparation method of which differs from that of Example 1 only in that: a sugar solution made by dissolving 1.5g glucose and 1.5g sucrose in 30g water is used instead of the Polygonatum odoratum extract in step (2), while all other conditions remain unchanged. Its appearance is as follows. Figure 10 As shown.

[0084] Comparative Example 3

[0085] This comparative example provides a Pu-erh tea made from Polygonatum odoratum, the preparation method of which is as follows:

[0086] (1) Take 50g of Yunnan large-leaf sun-dried green tea, mix it with 2g of Yunnan Sophora flavescens powder that has been crushed through a 50-mesh sieve, and spray it with 20g of water to soften the tea leaves. Then, microwave it at 2450MHz for 60s for later use.

[0087] (2) Take the *Aspergillus cristatus* strain and inoculate it into the softened tea leaves. The inoculation amount is 0.5% of the raw material, Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the first 3 days of fermentation, control the fermentation temperature at 25℃ and the humidity at 85%. During the middle 6 days of fermentation, control the fermentation temperature at 35℃ and the humidity at 75%. During the last 5 days of fermentation, control the fermentation temperature at 28℃ and the humidity at 60%.

[0088] (3) After fermentation, dry at 45℃ until the moisture content is 12% to obtain Golden Flower Polygonatum Pu-erh Tea, which has the appearance of... Figure 11 As shown.

[0089] Comparative Example 4

[0090] This comparative example provides a Pu-erh tea made from Polygonatum odoratum, the preparation method of which is as follows:

[0091] (1) Take 10g of Polygonatum yunnanense medicinal material, crush it through a 50-mesh sieve, add 10 times the weight of purified water, heat and reflux for 2 hours, filter to remove the residue to obtain Polygonatum yunnanense extract, and cool for later use.

[0092] (2) Take 50g of Yunnan large-leaf sun-dried green tea, spray 20g of water to soften the tea leaves, and microwave at 2450MHz for 60s for later use.

[0093] (3) Take the *Aspergillus cristatus* strain and inoculate it into the softened tea leaves. The inoculation amount is 0.5% of the raw Yunnan large-leaf sun-dried green tea. Place it in an incubator for fermentation. During the first 3 days of fermentation, control the fermentation temperature at 25℃ and the humidity at 85%. During the middle 6 days of fermentation, control the fermentation temperature at 35℃ and the humidity at 75%. During the last 5 days of fermentation, control the fermentation temperature at 28℃ and the humidity at 60%.

[0094] (4) After fermentation, the fermentation product is mixed with 20g of the Polygonatum extract obtained in step (1) and dried at 45℃ until the moisture content is 12% to obtain the Golden Flower Polygonatum Pu-erh Tea, which has the appearance of Figure 12 As shown.

[0095] Comparative Example 5

[0096] This comparative example provides a Pu-erh tea whose preparation method differs from Example 1 only in that it does not involve inoculation with *Aspergillus cristatus* for fermentation.

[0097] (1) Take 10g of Polygonatum yunnanense medicinal material, crush it through a 50-mesh sieve, add 10 times the weight of purified water, heat and reflux for 2 hours, filter to remove the residue to obtain Polygonatum yunnanense extract, and cool for later use.

[0098] (2) Take 50g of Yunnan large-leaf sun-dried green tea, spray 20g of Polygonatum extract to soften the tea leaves, and microwave at 2450MHz for 60s.

[0099] (3) Dry at 45℃ until the moisture content is 12% to obtain Golden Flower Polygonatum Pu-erh Tea, which has the following appearance: Figure 13 As shown.

[0100] Comparative Example 6

[0101] This comparative example uses Yunnan large-leaf sun-dried green tea as the raw material.

[0102] Test Example 1

[0103] The *Aurotriarcha* bacteria in the products obtained in Examples 1-8 and Comparative Examples 1-4 were counted:

[0104] (1) Preparation of control colony of *Aureobasidium cristatum* agar: Under a clean bench, select a slant of *Aureobasidium cristatum* with good growth, pick out a small number of cells with an inoculation loop, streak on a fresh PDA solid medium agar plate, and then incubate at 28℃ for 4 days. Select the cells and store them at 4℃ as controls for counting the colony morphology of *Aureobasidium cristatum*. The colonies are relatively regular and round, with white to light yellow edges, and the color gradually deepens to orange-yellow in the center. The colonies are golden yellow in color and have a diameter of 2-4 mm.

[0105] (2) Each tea sample was pulverized using a pulverizer. 25g of the pulverized sample was weighed and placed in a homogenizing bag containing 225mL of sterile physiological water. The sample was homogenized using a beater for 5 minutes to ensure thorough dispersion of microorganisms, thus preparing a 10-fold sample dilution. This solution was then serially diluted to 10 on a clean bench. -1 Take 1 mL of 10 -3 ~10 -6 Diluents were spread evenly on PDA plates using a spreader, with three replicates for each dilution. The plates were incubated upside down at 28°C. Colonies were observed on the plates from day 3 to day 5 of incubation. Plates with colony counts between 10 and 50 were selected, and colonies exhibiting characteristics consistent with *Aureobasidium cristatum* were counted. The *Aureobasidium cristatum* colonies on the plate were multiplied by the dilution factor to obtain the corresponding bacterial count per gram of sample, expressed as bacterial count / gram of tea. Specific data are shown in Table 1.

[0106] Table 1

[0107]

[0108]

[0109] As shown in Table 1, the preparation method of *Aspergillus cristatus* Pu-erh tea involved in this invention can ensure the quality and quantity of *Aspergillus cristatus* as the dominant microorganism in Pu-erh tea. The quantity of *Aspergillus cristatus* can be adjusted according to product needs, thereby improving product quality and achieving differentiation. Furthermore, both the sterilization method before fermentation and the fermentation method will affect the quality and quantity of *Aspergillus cristatus* in Pu-erh tea.

[0110] Test Example 2

[0111] The products obtained in Examples 1-8 and Comparative Examples 1-6 were subjected to sensory evaluation according to GB / T 23776-2018:

[0112] Take 3g of tea sample, add 150mL of boiling water and steep for 5 minutes before evaluation. Evaluation is based on appearance, liquor color, aroma, taste, and infused leaf appearance, with each item worth 100 points. The total score uses a weighted method, specifically the formula: Sensory Score = Appearance × 0.25 + Liquor Color × 0.10 + Aroma × 0.25 + Taste × 0.30 + Infused Leaf Appearance × 0.10. The appearance evaluation assesses shape, tenderness, color, integrity, purity, and the abundance and uniformity of golden buds (a type of agaric bloom). The liquor evaluation assesses color variety, hue, brightness, and clarity. The aroma evaluation assesses type, concentration, purity, and persistence. The liquor evaluation assesses strength, thickness, mellowness, astringency, purity, and freshness. The infused leaf evaluation assesses tenderness, color, brightness, and uniformity. Specific data are shown in Table 2.

[0113] Table 2

[0114]

[0115]

[0116] As shown in Table 2, the Pu-erh tea prepared by the method of the present invention, containing Polygonatum cyrtonema, produces a bright, clear, golden-yellow liquor with a rich, lasting aroma, a pure and refreshing fragrance, and a sweet, mellow taste with a strong mushroom aroma. The sterilization method before fermentation and the fermentation method both affect the above indicators. High-pressure steam sterilization significantly impacts the sensory evaluation of Pu-erh tea, mainly because prolonged heating greatly damages the nutritional and functional components. Without inoculation with *Aspergillus cristatus*, *Aspergillus cristatus* cannot become the dominant microorganism during fermentation, resulting in a slightly bitter taste after brewing.

[0117] Test Example 3

[0118] Take 10g of each of the Polygonatum odoratum Pu-erh teas prepared in Examples 1-8 and Comparative Examples 1-6, add 300mL of boiling water and extract for 15min, filter, concentrate, and freeze-dry to obtain the extract of Polygonatum odoratum Pu-erh tea. Prepare a 1.0mg / mL stock solution of the Polygonatum odoratum Pu-erh tea extracts obtained from each group, and dilute it in 7 fractions to determine their scavenging abilities of DPPH and ABTS to evaluate their antioxidant activity.

[0119] (1) DPPH scavenging ability test:

[0120] Add 100 μL each of sample solution and 0.1 mmol / L DPPH solution to a 96-well microplate, vortex to mix, and react in the dark for 30 min. Measure the absorbance at 517 nm and calculate the DPPH radical scavenging rate. Calculate the IC50. 50 (mg / L) values. Vitamin C was used as a positive control, and the results are shown in Table 3.

[0121]

[0122] Where A1 is the absorbance of the sample; A0 is the absorbance of the control experiment in which water is used instead of the sample solution; and A2 is the absorbance of the sample interference experiment in which anhydrous ethanol is used instead of DPPH solution.

[0123] (2) ABTS clearance capability test:

[0124] ABTS was prepared into a 2.0 mmol / L solution using ultrapure water. 50 mL of this solution was mixed thoroughly with 200 mL of a 70.0 mmol / L K₂S₂O₈ aqueous solution and allowed to stand in the dark for 15 h to obtain the ABTS free radical solution. The ABTS free radical solution was diluted with anhydrous ethanol to a working solution of 0.70 ± 0.02 at 734 nm. 10 μL of the sample solution and 190 μL of the ABTS working solution were added sequentially to a 96-well microplate. The reaction was carried out at 30 °C for 10 min. The absorbance at 734 nm was measured, and the ABTS free radical scavenging rate was calculated. The IC₂ value was also calculated. 50 (mg / L) values. Vitamin C was used as a positive control, and the results are shown in Table 3.

[0125]

[0126] Where A0 is the absorbance measured without the addition of sample solution; A1 is the absorbance of the sample; and A2 is the absorbance measured without the addition of ABTS free radical solution.

[0127] Table 3

[0128]

[0129]

[0130] As shown in Table 3, the extract of *Aspergillus cristatus* Pu-erh tea prepared by the method described in this invention exhibits excellent free radical scavenging effects, indicating that the combined use of *Aspergillus cristatus*, *Aspergillus*, and Pu-erh tea has a synergistic effect in antioxidation. Furthermore, the sterilization method before fermentation and the fermentation method also influence these effects to some extent.

[0131] The applicant declares that the technical solution of this invention is illustrated by the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0132] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0133] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A method for preparing a Pu-erh tea made from Polygonatum sibiricum, characterized in that, The preparation method includes: (1) After crushing the Polygonatum yunnanense, it was mixed with water and refluxed for extraction. After filtration, the Polygonatum yunnanense extract was obtained. (2) Mix the extract of Polygonatum sibiricum with Yunnan large-leaf sun-dried green tea and sterilize it with microwave. The microwave sterilization frequency is 1000-3000 MHz and the sterilization time is 60-90 s. The water content in the mixing system of step (2) is 30-50% of the mass of Yunnan large-leaf sun-dried green tea; (3) Inoculate the product from step (2) with *Aspergillus cristatus* strain for fermentation, wherein the inoculation amount of *Aspergillus cristatus* strain is 0.1-1% of the Yunnan large-leaf sun-dried green tea; The fermentation adopts a staged variable temperature fermentation method, specifically: the first stage fermentation: temperature 23-27℃, humidity 75-86%, time 2-4 days; the second stage fermentation: temperature 33-37℃, humidity 60-75%, time 3-6 days; the third stage fermentation: temperature 25-30℃, humidity 55-65%, time 3-6 days. (4) After fermentation, the tea is dried to obtain the Golden Flower Polygonatum Pu-erh Tea.

2. The method for preparing Polygonatum odoratum Pu-erh tea according to claim 1, characterized in that, The mass ratio of the Polygonatum odoratum raw material to water is 1:(8-12).

3. The method for preparing Polygonatum odoratum Pu-erh tea according to claim 1, characterized in that, The reflux extraction time is 1-3 hours.

4. The method for preparing Polygonatum odoratum Pu-erh tea according to claim 1, characterized in that, The drying process is carried out at 40~50℃.

5. The method for preparing Polygonatum odoratum Pu-erh tea according to claim 1, characterized in that, The endpoint of the drying process is to control the moisture content of the Polygonatum odoratum Pu-erh tea to 8%-14%.

6. A kind of golden flower polygonatum Pu-erh tea, characterized in that, The Golden Flower Polygonatum Pu-erh Tea is prepared using the method described in any one of claims 1-5.

7. The Golden Flower Polygonatum Pu-erh Tea according to claim 6, characterized in that, The product form of the Golden Flower Polygonatum Pu-erh Tea is any one of the following: loose tea, tea cake, brick tea, tuocha, or thin slices.

8. The application of the aqueous extract of Polygonatum odoratum Pu-erh tea according to claim 6 or 7 in the preparation of functional foods or cosmetics.

9. The application of the aqueous extract of Polygonatum odoratum Pu-erh tea according to claim 6 or 7 in the preparation of food or cosmetics with antioxidant effects.

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