Leaves of astragalus membranaceus fermented ripening tea and preparation method therof

Abstract

The present invention relates to a method for manufacturing fermented and aged Astragalus leaf tea, and more specifically, to a method for manufacturing fermented and aged Astragalus leaf tea by fermenting and aging Astragalus leaves in a specific stage, thereby improving palatability and aroma, which are limitations of Astragalus leaves, while allowing the active ingredients of the Astragalus leaves themselves to be effectively extracted into the tea.

Description

Technology Field

[0001] The present invention relates to fermented and aged Astragalus leaf tea and a method for manufacturing the same. More specifically, it relates to a method for manufacturing fermented and aged Astragalus leaf tea by processing Astragalus leaves into tea through specific steps, thereby allowing the active ingredients of the Astragalus leaves themselves to be extracted into the tea while possessing a harmonious aroma and taste. Background Technology

[0003] Astragalus refers primarily to the dried roots of *Astragalus membranaceus*, a legume. Astragalus grows in sunny areas of high mountainous regions in northern Korea; the roots are dug up in autumn or spring, washed with water, and dried in the sun for use. It has a sweet taste and a warm nature. The main components of Astragalus roots include formononetin, astraisoflavan, astrapterocarpan, and β-sitosterol. Its efficacy has been established in stopping sweating, promoting urination, eliminating pus, stimulating tissue regeneration, and providing tonic, immune function regulating, cardiotonic, diuretic, blood pressure-lowering, and anti-inflammatory effects. However, the flavor of the dried Astragalus root is only extracted when it is roasted yellow during cooking, and when brewed as tea, almost no taste or aroma is detected other than a slight bitterness, so there are limitations to developing it as tea.

[0004] The stems grow in clusters, and the leaves are odd-pinnately compound, consisting of 6 to 11 pairs of leaflets. The leaflets are approximately 1 to 2 cm long, egg-shaped to elliptical, and have smooth margins. The stipules are lanceolate with long, pointed tips, and long-stalked flower spikes emerge in racemes from the leaf axils, bearing 5 to 10 flowers. Yellowish-white flowers bloom in July and August, measuring approximately 2 cm in length, with pedicels about 3 mm long. The calyx is approximately 5 mm long, covered with dark brown hairs, and splits into five lobes. There are 10 stamens, and the fruit ripens in November; it is a legume. The pod is elongated elliptical with pointed ends, measuring 2 to 3 cm in length, and contains 5 to 7 seeds.

[0005] The main components of the stems and leaves of Astragalus are calycosin-7-o-ß-d-glucoside, ononin, calycosin, and formononetin. It is known to be effective for liver health, fever reduction, anti-inflammation, and antioxidant effects. It is also known to have a warm nature, a sweet taste, and be non-toxic. Unlike the roots, Astragalus leaves have a slightly savory taste and a distinctive fragrant aroma when brewed as tea; however, they are inherently weak in sweetness and have a slight grassy taste, requiring additional techniques to enhance their flavor.

[0006] Regarding related technologies utilizing Astragalus, Korean Public Patent No. 10-2022-0123791 discloses a health herbal tea bag containing Astragalus and a method for manufacturing the same. Specifically, it suggests that since Astragalus is included as an active ingredient, it replenishes vital energy and has effects such as strengthening the constitution, mental stability, and blood circulation, making it effective for boosting immunity; thus, it indicates that it can be utilized as a functional beverage for enhancing the immunity of busy modern people. In a specific embodiment, it discloses the addition of Astragalus, Atractylodes macrocephala, Saposhnikovia divaricata, Panax ginseng, Glycyrrhiza glabra, Angelica gigas, Citrus peel, Cimicifuga dahurica, and Bupleurum chinense in specific weight parts. However, as previously explained, since there is no particular taste or aroma when Astragalus root is steeped into tea, the above technology extracts only the beneficial components of Astragalus and achieves the taste through other ingredients; therefore, it is difficult to regard it as an Astragalus tea possessing its own unique taste.

[0007] In addition, Korean registered patent No. 10-2060702 discloses a fermented beverage using Ophiopogon japonicus, Schisandra chinensis, and Astragalus membranaceus, and a method for manufacturing the same. Specifically, the invention aims to provide consumers with a beverage that enhances antioxidant, anti-inflammatory, and internal immunity by preparing a malt culture medium using malt extract and water, preparing a culture medium by inoculating the prepared malt culture medium with lactic acid bacteria to culture the starter culture, preparing an extract by hot water extraction of powdered Ophiopogon japonicus, Schisandra chinensis, and Astragalus membranaceus, preparing a fermented liquid by mixing the prepared malt culture medium, extract, culture medium with sugar and fermenting it, and manufacturing a beverage by adding fruit juice to the prepared fermented liquid and blending it. However, this also cannot be considered a beverage that possesses the unique aroma and taste of Astragalus membranaceus itself.

[0008] As such, Astragalus possesses numerous nutrients and benefits. As previously mentioned, the term *Hwanggi* refers to the dried root of *Danseom* (a type of Astragalus). While the root is widely used for beverages and other food ingredients, the leaves are not widely utilized in the food industry, except for their use as wrap vegetables. Nevertheless, Astragalus leaves have the advantage of possessing a refreshing and subtle aroma and a savory taste; however, the savory flavor is too weak for consumption as tea, and there is almost no sweetness or umami, with a grassy taste present, which limits its suitability for tea. Consequently, despite containing many beneficial components, it has been difficult to develop tea products that satisfy consumer preferences. Therefore, there is a need to develop food products utilizing Astragalus leaves that are easy to consume while satisfying the diverse tastes of modern people.

[0009] Accordingly, the inventors have made efforts to develop a food product that contains healthy Astragalus leaves as an active ingredient while simultaneously improving palatability so that it can be easily consumed by anyone, regardless of age or gender.

[0010] It was confirmed that the unique lack of flavor can be improved and the tea can be consumed with a good aroma and deep flavor through a process of washing, drying, steaming, shade drying, fermenting and aging, shade drying, roasting, and aroma locking of Astragalus leaves, and thus the present invention was completed. Prior art literature

[0012] Republic of Korea Published Patent No. 10-2022-0123791 Republic of Korea Registered Patent No. 10-2060702 The problem to be solved

[0013] The objective of the present invention is to provide a method for manufacturing fermented and aged Astragalus leaf tea with enhanced inherent beneficial effects and overall palatability. means of solving the problem

[0015] To achieve the above objective, the present invention

[0016] 1) Step of washing the harvested Astragalus leaves;

[0017] 2) A step of drying until the humidity of 1) becomes 20 to 30%;

[0018] 3) A step of steaming the ingredients from Step 2) using water containing coarse salt;

[0019] 4) A step of air-drying the steamed material from Step 3) until the humidity reaches 30 to 50%;

[0020] 5) A step of adding cinnamon and licorice to the shade-dried materials from Step 4), adding honey to water boiled over medium heat for 30 to 60 minutes, evenly spraying and adding hot water cooled to 25 to 35°C, and fermenting and aging;

[0021] 6) A step of air-drying the fermented and aged material from Step 5) until the humidity reaches 20 to 40%;

[0022] 7) A step of roasting the air-dried material from Step 6) using a heating device at a temperature of 50 to 70°C until the humidity becomes 10% or less, and then cooling it;

[0023] 8) Step of preparing tea by roasting the ingredients from Step 7 at a temperature of 70-90℃ until no moisture remains.

[0024] 9) A step of removing the material of step 8) from the heating device; and

[0025] 10) A method for manufacturing fermented aged Astragalus leaf tea is provided, comprising the step of cooling the heating device for 3 to 5 minutes, and then adding the material of 9) back to the heating device to trap the aroma.

[0026] In addition, the present invention provides fermented aged tea made from Astragalus leaves according to the method of the present invention. Effects of the invention

[0028] The fermented and aged Astragalus leaf tea produced by the method according to the present invention can provide not only the beneficial effects of Astragalus leaves but also a tea with excellent flavor. Specific details for implementing the invention

[0030] The present invention will be described in more detail below.

[0031] The present invention is,

[0032] 1) Step of washing the harvested Astragalus leaves;

[0033] 2) A step of drying until the humidity of 1) becomes 20 to 30%;

[0034] 3) A step of steaming the ingredients from Step 2) using water containing coarse salt;

[0035] 4) A step of air-drying the steamed material from Step 3) until the humidity reaches 30 to 50%;

[0036] 5) A step of adding cinnamon and licorice to the shade-dried materials from Step 4), adding honey to water boiled over medium heat for 30 to 60 minutes, evenly spraying and adding hot water cooled to 25 to 35°C, and fermenting and aging;

[0037] 6) A step of air-drying the fermented and aged material from Step 5) until the humidity reaches 20 to 40%;

[0038] 7) A step of roasting the air-dried material from Step 6) using a heating device at a temperature of 50 to 70°C until the humidity becomes 10% or less, and then cooling it;

[0039] 8) Step of preparing tea by roasting the ingredients from Step 7 at a temperature of 70-90℃ until no moisture remains.

[0040] 9) A step of removing the material of step 8) from the heating device; and

[0041] 10) A method for manufacturing fermented aged Astragalus leaf tea is provided, comprising the step of cooling the heating device for 3 to 5 minutes, and then adding the material of 9) back to the heating device to trap the aroma.

[0042] Hereinafter, the method for manufacturing fermented and aged tea from Astragalus leaves according to the present invention will be described in detail step by step.

[0043] Step 1) above is a step of washing the Astragalus leaves and removing the water. The Astragalus leaves may be harvested around May to August, but are not limited thereto.

[0044] Step 2) above is a step of drying the material of 1) until the humidity reaches 20 to 30%, and

[0045] Step 3) above is a step of steaming the ingredients of Step 2) using water containing coarse salt. Specifically, coarse salt is added to water, and when the water boils, the ingredients of Step 2) are added and steamed, and then the mixture is kept in mind. The salt may be added in an amount of 0.05 to 0.5 weight% relative to 100 weight% of the water, and specifically, 0.1 to 0.25 weight% may be added. Additionally, the steaming may be performed for 1 to 8 minutes, or for 3 to 5 minutes, but is not limited thereto. By adding salt, sterilization and blanching effects can be achieved, the color can be made more vivid, and components can be extracted more effectively when brewing tea. Furthermore, adding a slight saltiness can enhance the umami flavor and provide an effect of improving inflammation.

[0046] Step 4) above is a step of air-drying the steamed material from Step 3) until the humidity reaches 30 to 50%. If air-drying is performed at a humidity of less than 30%, the material may break during the processing stage, and if the humidity is 50% or higher, it may hinder the proper absorption of the hot water into the material when the hot water is subsequently sprayed. Additionally, if Astragalus leaves are sun-dried, they may lose their original color due to the loss of moisture contained in the leaves, so it is preferable to perform air-drying. The air-drying can be performed naturally in a well-ventilated shade, or artificially using a heating plate, a dryer, or a ventilation device, but is not limited thereto.

[0047] Step 5) above is a step of adding cinnamon and licorice to the shade-dried materials of Step 4), adding honey to water boiled over medium heat for 30 to 60 minutes, evenly spraying and adding decoction water cooled to 25 to 35°C, and fermenting and aging at a temperature of 30 to 50°C. The decoction water may be prepared by adding 0.2 to 0.5% by weight of cinnamon and 0.1 to 0.3% by weight of licorice to 100% by weight of water, boiling water over medium heat for 30 to 60 minutes, and adding 0.1 to 0.5% by weight of honey to 100% by weight of water. Specifically, 0.3 to 0.4% by weight of cinnamon, 0.15 to 0.25% by weight of licorice, and 0.2 to 0.4% by weight of honey may be added to 100% by weight of water; more specifically, 0.3% by weight of cinnamon and 0.25% by weight of licorice may be added to 100% by weight of water, and 0.3% by weight of cinnamon and 0.25% by weight of licorice may be added to 100% by weight of water. 0.2% by weight and 0.3% by weight of honey may be added.

[0048] Cinnamon has a warm nature, aids digestion, and adds a unique aroma; however, if added in an amount exceeding 0.5% by weight, it produces a spicy taste, and the unique scent of cinnamon can interfere with the aroma of Astragalus leaves. Additionally, although licorice is introduced in the *Donguibogam* as being compatible with Astragalus and helping with the absorption of beneficial components, if added in an amount exceeding 0.3% by weight, the sweetness becomes excessively strong, resulting in a characteristic bitter and astringent taste that detracts from the flavor. However, when tea was prepared by adding cinnamon at 0.3% by weight or less, the sweetness was slightly weak, so honey, a natural sugar, was added to enhance the sweetness and complete the optimal combination.

[0049] However, since Astragalus leaves have a relatively thick epidermis, high fiber content, and tough nature, there is a problem in that the components of the decoction (with added licorice, cinnamon, and honey) are not well absorbed in steam form when added during the steaming process. Therefore, it is desirable to soften the tissue of the Astragalus leaves through a kneading step and then add them via the process described above so that they can be sufficiently absorbed during the fermentation and aging process.

[0050] In addition, an experiment was conducted to ferment and age the leaves by covering a cotton cloth with plastic film and then covering that with a thick cloth; however, as the humidity remained high due to the plastic film, the upper part of the Astragalus leaves rotted. Accordingly, the fermentation and aging process was carried out by covering the leaves in the order of cotton cloth, then thick cloth, excluding the plastic film, while maintaining a constant temperature.

[0051] The above fermentation aging can be performed at a temperature of 30 to 60°C, specifically at a temperature of 30 to 50°C. In addition, the above fermentation aging can be performed for 6 to 12 hours, specifically at a temperature of 8 to 10 hours.

[0052] Fermentation time and temperature are factors determined differently depending on the raw materials added to optimize the taste and flavor of the raw materials; therefore, when using the materials added in this invention, compliance with the above fermentation and aging time and temperature is essential. If the above temperature and time are deviated during the fermentation process, the flavor may deteriorate during tea brewing, and the deep taste of the tea may be compromised due to over-fermentation of specific components. Internal test results confirmed that the best taste is produced when fermented for 8 hours or more.

[0053] Step 6) above is a step of air-drying the fermented and aged material of Step 5) until the humidity reaches 20 to 40%, and

[0054] Step 7) above is a step of roasting and cooling the air-dried material from Step 6) using a heating device at a temperature of 50 to 70°C to remove moisture until the humidity is 10% or less, and a roasting pan or a roasting pot may be used as the heating device. If roasting is performed at a temperature exceeding 70°C from the beginning, problems may occur where the material burns or the upper part of the material dries out first and crumbles; therefore, it is preferable to maintain the above temperature and then increase the temperature while undergoing the roasting process as described in the following step.

[0055] Step 8) above is a step of roasting the material of Step 7 at a temperature of 70-90℃ until there is no moisture, and Step 9) above is a step of removing the material of Step 8) from the heating device.

[0056] Step 10) above is a step of cooling the heating device for 3 to 5 minutes, and then adding the material of 9) back into the heating device to trap the fragrance. Specifically, the material of step 9) is removed from the heating device, placed on a sieve, covered with a cotton cloth to cool, and the remaining moisture is removed for 3 to 5 minutes. During this process, when the heating device has cooled down to some extent, the material of 9) is added back into the heating device to trap the fragrance for 3 to 5 hours, and then stored in a sterilized bottle container.

[0057] In a specific embodiment of the present invention, the inventors completed fermented and aged Astragalus leaf tea by washing and drying Astragalus leaves and finishing with steaming, shade drying, fermentation and aging, shade drying, roasting, and aroma retention to produce Astragalus leaf tea.

[0058] In addition, the inventors performed a sensory evaluation by brewing the Astragalus leaf tea and the Astragalus leaf tea prepared by a general method of preparing Astragalus leaf tea, and confirmed that the overall preference, including the color, taste, and aroma of the tea brewed with the Astragalus leaf tea of ​​the present invention, was superior to the overall preference of Astragalus leaf tea prepared by other methods.

[0059] Therefore, the Astragalus leaf tea produced according to the method of the present invention not only possesses the beneficial effects of Astragalus leaves but also retains its unique taste and aroma, thereby providing consumers with satisfaction of the five senses.

[0060] The present invention will be explained in detail below through examples, comparative examples, and experimental examples.

[0061] However, the following examples, comparative examples, and experimental examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following examples, comparative examples, and experimental examples.

[0063] <Example 1> Preparation of Fermented and Aged Astragalus Leaf Tea

[0064] To produce fermented aged Astragalus leaf tea, the following steps were performed.

[0066] <1-1> Raw Material Preparation and Drying Steps

[0067] Astragalus leaves harvested in July were removed from their stems, washed thoroughly, dried, and dried until the humidity reached 20 to 30%.

[0068] <1-2> Kneading and Shading Steps

[0069] The above <1-1> ingredients were mixed with 3g of coarse salt in 2L of water and steamed for 5 minutes while the water was boiling vigorously. Afterward, the ingredients were thoroughly kneaded and dried in the shade until the humidity reached 40%.

[0070] <1-3> Step of fermenting and aging after preparing and adding the hot water

[0071] 3g of cinnamon and 2g of licorice were added to 1 liter of water and boiled over medium heat for 45 minutes. Then, 3g of honey was added to the water and mixed well, and the mixture was cooled to 30℃ to prepare the hot water. The materials of Example <1-2> were spread evenly on a straw mat, sprayed with the hot water to evenly moisten them, covered with a cotton cloth and a thick blanket, and fermented at 40℃ for 8 hours.

[0072] <1-4> Sound drying stage

[0073] The fermented and aged Astragalus leaves obtained in the above Examples <1-3> were air-dried until the humidity reached 30%.

[0074] <1-5> Roasting and Tea Making Stages

[0075] The above shade-dried Astragalus leaves were roasted in a roasting pan at a temperature of 50℃-70℃ until the humidity was 10% or less, and then the temperature was raised to maintain a range of 70℃ to 90℃ and processed until there was almost no moisture.

[0076] <1-6> Scent confinement stage

[0077] In the above Examples <1-5>, the roasted and processed Astragalus leaves were removed, placed on a sieve, covered with a cotton cloth, and the remaining moisture was removed while cooling the roasting pan for about 3-5 minutes. Then, the Astragalus leaves that had been removed and stored separately were put back into the roasting pan, and the aroma was trapped for 4 hours with the cloth placed over the pan until the heat completely cooled down, thereby producing fermented and aged Astragalus leaf tea.

[0078] <Comparative Example 1> Preparation of fermented and aged Astragalus leaf tea with different steaming processes

[0079] <1-1> Preparation of Fermented Aged Tea Using Water-Steamed Astragalus Leaves

[0080] Fermented aged Astragalus leaf tea was prepared according to the manufacturing method of <Example 1>, except that in the step of Example <1-2> above, it was steamed with water without added salt.

[0081] <1-2> Preparation of tea made by adding only licorice to decoction and fermenting and aging it

[0082] Fermented aged Astragalus leaf tea was prepared according to the manufacturing method of <Example 1>, except that water boiled with only licorice was added in the steps of <Example 1-3> above.

[0083] <1-3> Preparation of fermented and aged tea with the addition of licorice, cinnamon, and honey during the steaming process

[0084] Astragalus leaf tea was prepared according to the method of <Example 1>, except that licorice, cinnamon, and honey were not added by spraying during the fermentation and aging process of Example <1-3>, and licorice, cinnamon, and honey were added in the same ratio as in Example 1 (6g of cinnamon, 4g of licorice, and 6g of honey added to 2L of water) along with coarse salt during the process of Example <1-2> and steamed.

[0086] <Comparative Example 2> Preparation of roasted Astragalus leaf tea without a fermentation and aging process

[0087] Astragalus leaf tea was prepared according to the manufacturing method of <Example 1>, except that the fermentation and aging process of the steps of <1-4> above was not undergone.

[0089] <Experimental Example 1> Sensory Evaluation

[0090] Sensory evaluation was performed on the fermented aged Astragalus leaf tea of ​​<Example 1> prepared by the method according to the present invention, the fermented aged Astragalus leaf tea prepared by the method of <Comparative Example 1>, and the roasted Astragalus leaf tea prepared by the method of <Comparative Example 2>.

[0091] Specifically, for the sensory evaluation, 5 g of each prepared tea sample was taken to determine the color, taste, aroma, and overall preference for the fermented aged Astragalus leaf tea of ​​<Example 1> prepared according to the present invention, the fermented aged Astragalus leaf tea of ​​<Comparative Example 1> prepared without adding salt during steaming, the Astragalus leaf tea prepared by adding only licorice during the fermentation and aging process, the Astragalus leaf tea prepared by adding licorice, cinnamon, and honey in the same ratio as Example 1 along with coarse salt during the fermentation and aging process of <Example 1-2>, and the roasted Astragalus leaf tea of ​​<Comparative Example 2> prepared without undergoing the fermentation and aging process. After adding hot water at 85°C, the taste, aroma, color, and overall preference of the tea were evaluated after 30 seconds.

[0092] The taste, aroma, color, and overall preference of the tea were evaluated by 30 fully trained professional sensory testers on a 5-point scale, with the scores being very good (5), good (4), average (3), not good (2), and not very good (1), and the average score was determined.

[0093] The judgment criteria are as follows.

[0094] Very good: 4.6 to 5.0 points;

[0095] Good: 3.6 to 4.5 points;

[0096] Average: 2.6 to 3.5 points;

[0097] Not good: 1.6 ~ 2.5 points; and

[0098] Very poor: 1.0 to 1.5 points;

[0099] As a result, as shown in Table 1, compared to the fermented aged Astragalus leaf tea of ​​<Example 1> prepared according to the manufacturing method of the present invention, the fermented aged Astragalus leaf tea of ​​Comparative Example <1-1>, prepared using water without adding coarse salt during steaming, had a slightly savory and sweet taste, but many opinions were that the color was light and the umami taste was lacking, and it received a relatively lower evaluation compared to the present invention in terms of color, taste, aroma, and overall preference. The fermented aged Astragalus leaf tea of ​​Comparative Example <1-2>, prepared by adding water containing only licorice during the fermentation and aging process, had improved taste and aroma compared to Comparative Example <1-1>, but many opinions were that the color was light and the aroma was weak. Accordingly, it was confirmed that the fermented and aged Astragalus leaf tea of ​​Comparative Example <1-3>, which was steamed without adding the decoction water of Example 1 during the fermentation and aging process and added the same amount of licorice, cinnamon, and honey as in Example 1 during the steaming process, had weaker flavors and aromas other than the savory taste and received a lower evaluation than the fermented and aged Astragalus leaf tea of ​​the present invention.

[0100] In addition, compared to the fermented aged tea of ​​<Example 1> prepared according to the manufacturing method of the present invention, the roasted astragalus leaf tea of ​​<Comparative Example 2> prepared without undergoing the fermentation and aging process was evaluated as having a grassy taste and weak sweetness and aroma, and it was confirmed that it received low evaluations in taste, aroma, and overall preference.

[0101] Therefore, through the above results, it was confirmed that the fermented aged Astragalus leaf tea produced according to the manufacturing method of the present invention brews more intensely and produces a deep flavor with a moderate sweetness, nutty taste, and moderate bitterness, compared to fermented aged Astragalus leaf tea or roasted Astragalus leaf tea produced by other manufacturing methods, and exhibits significantly superior color, taste, aroma, and overall palatability. Furthermore, it was confirmed that by establishing an optimized manufacturing method for high-quality fermented aged Astragalus leaf tea through the steaming process and the presence or absence of fermentation and aging for the production of fermented aged Astragalus leaf tea, high-quality fermented aged Astragalus leaf tea can be provided to consumers.

[0102] No. color taste incense Overall preference Example 1 4.8 4.8 4.6 4.7 Comparative Example 1-1 3.6 3.6 3.8 3.7 Comparative Example 1-2 3.8 3.0 3.8 3.3 Comparative Examples 1-3 4.0 3.2 3.6 3.6 Comparative Example 2 2.8 2.6 2.6 2.7

Claims

Claim 1 1) a step of washing the harvested Astragalus leaves; 2) a step of drying until the humidity of step 1) reaches 20 to 30%; 3) a step of steaming the material from step 2) using water containing coarse salt; 4) a step of shade-drying the steamed material from step 3) until the humidity reaches 30 to 50%; 5) a step of adding 0.2 to 0.5% by weight of cinnamon and 0.1 to 0.3% by weight of licorice relative to 100% by weight of water to the shade-dried material from step 4), boiling the mixture over medium heat for 30 to 60 minutes, adding 0.1 to 0.5% by weight of honey relative to 100% by weight of water, and evenly spraying and adding the decoction cooled to 25 to 35°C, and fermenting and aging the mixture, wherein the fermentation and aging is performed by spreading the material evenly on a straw mat, covering it with a cotton cloth, covering it with a thick cloth, and at a temperature of 30-50°C A method for manufacturing fermented and aged Astragalus leaf tea comprising: a step of fermenting and aging for 8-10 hours; 6) a step of air-drying the fermented and aged material of step 5) until the humidity reaches 20 to 40%; 7) a step of roasting the air-dried material of step 6) using a heating device at a temperature of 50 to 70°C until the humidity reaches 10% or less, and then cooling it; 8) a step of roasting the material of step 7 at a temperature of 70-90°C until there is no moisture left; 9) a step of removing the material of step 8) from the heating device; and 10) a step of cooling the heat of the heating device for 3 to 5 minutes, and then adding the material of step 9) back into the heating device to trap the aroma. Claim 2 delete Claim 3 Fermented aged Astragalus leaf tea prepared by the method of claim 1.

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