A kind of preparation method of quinoa black tea
By using quinoa leaves for atrophy, rolling, fermenting and drying, and adding enzymes and compound bacteria agents, the problem of quinoa tea failing to make full use of quinoa leaves is solved, achieving high nutritional value and the effect of clear tea soup.
Patent Information
- Application Number
- CN202310432774.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-21
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2043-04-21
AI Technical Summary
The existing preparation methods for quinoa tea mainly use quinoa seeds, and the quinoa leaves are not fully utilized, resulting in the failure to fully exert nutritional value, and the tea soup is prone to turbidity and bitterness.
Quinoa leaves are used as raw materials, and quinoa leaves in the flowering period are selected for atrophy, rolling, fermenting and drying, and mixed enzymes and compound bacterial agents are added to ensure the precipitation of nutrients and the clearness of the tea soup.
A quinoa black tea with a good taste was obtained. The tea soup was clear and even, and the content of nutrients such as polyphenols, polysaccharides, flavonoids was high, which avoided the turbidity and bitterness of the tea soup and improved the overall quality of the tea.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of tea processing, and in particular to a preparation method of quinoa black tea. Background Art
[0002] Quinoa, with a protein content of about 16% to 18%, is of high quality and does not contain gluten. People with celiac disease or other digestive system diseases can supplement their nutrition by eating quinoa. Quinoa is not only rich in dietary fiber, vitamins and minerals, but also contains all the essential fatty acids and amino acids needed by the human body, as well as polyphenols, flavonoids, saponins, betaine, phytosterols and other phytochemicals that are beneficial to human health. It is a high-protein, low-calorie, alkaline food rich in active substances. Quinoa leaves are also rich in nutrition, and their mineral and vitamin content is higher than that of commonly eaten leafy vegetables. At the same time, quinoa leaves are rich in protein, lipids, polyphenols, flavonoids, ash, cellulose, vitamins, mineral elements and other substances, making them a good plant resource.
[0003] As people's pace of life accelerates, problems such as high blood pressure, high blood lipids, and decreased immunity seriously trouble people's healthy lives; tea contains polyphenols, flavonoids, tea polysaccharides and other substances, so it has a good inhibitory effect on the above diseases. Chinese patent document CN108651665A discloses a method for preparing quinoa tea, which obtains quinoa tea through pretreatment, enzyme activation and germination, maturation and enzyme breaking, air flow drying, and post-treatment; Chinese patent document CN115462428A discloses quinoa tea and its preparation method, which obtains quality differences through the selection of quinoa raw materials, removal of impurities and metals from quinoa raw materials, hydration and moisturizing of quinoa raw materials, disinfection of quinoa raw materials, enzyme inactivation treatment of quinoa raw materials, baking of quinoa raw materials, and packaging of quinoa tea. Small quinoa tea; however, both Chinese patent document CN108651665A and Chinese patent document CN115462428A use quinoa seeds as raw materials to make tea, and do not use quinoa leaves, and do not ensure the full utilization of quinoa raw materials; at the same time, since quinoa is rich in protein and starch, turbidity problems are prone to occur during the preparation of quinoa tea; in addition, during the tea making process, due to the presence of tea polyphenols, caffeine, tea saponins, anthocyanins, etc., the brewed tea will have a bitter taste, affecting the overall taste of the tea. Summary of the invention
[0004] In view of the problems existing in the above prior art, the purpose of the present invention is to provide a method for preparing quinoa black tea, which uses quinoa leaves as raw materials to fully utilize quinoa; at the same time, the quinoa black tea prepared by the method has good taste, does not have the problem of turbid tea soup, and has high nutritional value.
[0005] The purpose of the present invention is achieved through the following technical solutions:
[0006] A method for preparing quinoa black tea, characterized by comprising:
[0007] Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 48th to 52nd day after quinoa planting;
[0008] Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering them to reduce their moisture content to 75-77%;
[0009] Step S3, rolling: putting the wilted quinoa leaves into a rolling machine for repeated rolling, and adding a mixed enzyme and a composite bacterial agent into the rolling machine at the beginning of rolling;
[0010] Step S4, fermentation: placing the rolled quinoa leaves, the mixture of the mixed enzyme and the composite bacterial agent in an incubator for fermentation;
[0011] Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying. After drying, spreading them to air at room temperature to obtain quinoa black tea.
[0012] For further optimization, a pre-treatment process of quinoa leaves is also performed after step S1 and before step S2, specifically: first, the harvested quinoa leaves are de-impurized to remove impurities contained in the quinoa leaves; then, the de-impurated quinoa leaves are soaked in clean water to clean the quinoa leaves.
[0013] For further optimization, the flattened thickness of the quinoa leaves in step S2 is 2.5-3.5 cm, the withering time is 11-13 h, the withering method is sunlight withering, and the withering temperature is 23-27° C.
[0014] For further optimization, the mass ratio of the wilted leaves, the composite bacterial agent and the mixed enzyme during the rolling process of step S3 is 65-85:5-7:0.6-0.8; wherein the mixed enzyme is a mixture of cellulase and pepsin, and the composite bacterial agent is composed of Lactobacillus plantarum and Bacillus subtilis.
[0015] Preferably, the mass ratio of cellulase to pepsin is 0.8-1.2:1, the activity unit of cellulase is 5000-7500 U / mg, and the activity unit of pepsin is 3000-3500 U / mg; the mass ratio of Lactobacillus plantarum to Bacillus subtilis is 1.5-2.5:1-2.
[0016] For further optimization, the kneading time in step S3 is 28 to 32 minutes.
[0017] For further optimization, the fermentation temperature in step S4 is 26-30° C., and the fermentation time is 6.5-7.5 h.
[0018] For further optimization, the drying temperature in step S5 is 78-82° C., and the drying time is 2.7-3.3 h.
[0019] For further optimization, after the quinoa black tea is prepared in step S5, the step also includes preserving the quinoa black tea, specifically: placing the prepared quinoa black tea in a vacuum bag, and storing the vacuum bag at a low temperature of 1 to 6°C.
[0020] The present invention has the following technical effects:
[0021] The present application effectively ensures the nutritional indicators of quinoa leaves such as fat, cellulose, polysaccharides, polyphenols, flavonoids, and protein by selecting quinoa in full bloom, and balances the relationship between growth indicators (i.e., plant height, number of true leaves, fresh weight, water content, dry matter, fresh-to-dry ratio, stem-to-leaf ratio, fresh grass yield, and hay yield) and nutritional indicators, thereby ensuring that quinoa leaves with higher nutritional value are obtained while ensuring that the yield of quinoa leaves at this stage is high, which is conducive to batch tea making; at the same time, the present application adds mixed enzymes and composite bacterial agents during the rolling process, firstly, to ensure that the mixed enzymes, the composite bacterial agents and the quinoa tea juice are fully contacted to enhance the precipitation of nutrients, and secondly, to utilize the synergistic effect of the composite bacteria-mixed enzyme of the present invention to effectively and fully decompose substances such as proteins and esters in quinoa leaves, thereby avoiding turbidity of the tea soup and ensuring clarity of the tea soup, and at the same time, it can also ensure the formation of more theaflavins and thearubigins, effectively reducing the bitter taste caused by the high content of tea polyphenols, caffeine, tea saponins, anthocyanins, etc., and improving the taste of quinoa black tea.
[0022] The quinoa black tea prepared by the method of the present application has high contents of polyphenols, polysaccharides, flavonoids and other nutritional elements, retains the nutritional functional components of the quinoa leaf raw material to the greatest extent, the surface color of the tea leaves is uniform and the quality is good, and the tea soup after brewing is clear and uniform without turbidity, precipitation and other problems. The tea soup has the inherent fragrance of tea, no bitterness, and has a good taste when drunk. DETAILED DESCRIPTION
[0023] The technical scheme of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0024] Embodiment 1:
[0025] A method for preparing quinoa black tea, characterized by comprising:
[0026] Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 48th day after quinoa planting;
[0027] Pre-treatment process: first, the harvested quinoa leaves are de-impurified to remove impurities contained in the quinoa leaves; then, the de-impurified quinoa leaves are soaked in clean water to clean the quinoa leaves.
[0028] Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering, the quinoa leaves being laid out to a thickness of 2.5 cm; the withering method is sunlight withering, the withering temperature is 23° C., and the withering time is 11 h, so that the moisture content is reduced to 75%;
[0029] Step S3, rolling: putting the wilted quinoa leaves into a rolling machine (the rolling machine can be a common rolling machine on the market in this field) and rolling them repeatedly for 28 minutes;
[0030] At the beginning of rolling, mixed enzyme and compound bacterial agent were added to the rolling machine simultaneously. The weight of wilting leaves, compound bacterial agent and mixed enzyme were 65g, 5g and 0.6g respectively. Among them, the mixed enzyme was a mixture of cellulase and pepsin, with a mass ratio of 0.8:1, the activity unit of cellulase was 5000-7500U / mg, and the activity unit of pepsin was 3000-3500U / mg; the compound bacterial agent was composed of Lactobacillus plantarum and Bacillus subtilis, with a mass ratio of 1.5:1, Lactobacillus plantarum was CCTCC AB 2011143, and Bacillus subtilis was CCTCC AB 130001, both of which were purchased from China Center for Type Culture Collection (CCTCC);
[0031] Knead until the tea juice overflows but does not drip.
[0032] Step S4, fermentation: placing the rolled quinoa leaves, the mixture of the mixed enzyme and the composite bacterial agent in an incubator for fermentation; the fermentation temperature is 26° C., and the fermentation time is 6.5 hours.
[0033] Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying, the drying temperature is 78° C., and the drying time is 2.7 hours; after the drying is completed, spreading and airing to room temperature to obtain quinoa black tea.
[0034] Embodiment 2:
[0035] A method for preparing quinoa black tea, characterized by comprising:
[0036] Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 50th day after quinoa planting;
[0037] Pre-treatment process: first, the harvested quinoa leaves are de-impurified to remove impurities contained in the quinoa leaves; then, the de-impurified quinoa leaves are soaked in clean water to clean the quinoa leaves.
[0038] Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering, the thickness of the quinoa leaves being 3 cm; the withering method is sunlight withering, the withering temperature is 25° C., and the withering time is 12 h, so that the moisture content is reduced to 76%;
[0039] Step S3, rolling: putting the wilted quinoa leaves into a rolling machine (the rolling machine can be a common rolling machine on the market in this field) and rolling them repeatedly for 30 minutes;
[0040] At the beginning of rolling, mixed enzyme and compound bacterial agent were added to the rolling machine simultaneously. The weight of wilting leaves, compound bacterial agent and mixed enzyme were 75g, 6g and 0.7g respectively. Among them, the mixed enzyme was a mixture of cellulase and pepsin, with a mass ratio of 1:1, the activity unit of cellulase was 5000-7500U / mg, and the activity unit of pepsin was 3000-3500U / mg; the compound bacterial agent was composed of Lactobacillus plantarum and Bacillus subtilis, with a mass ratio of 2:1.5, Lactobacillus plantarum was CCTCC AB 2011143, and Bacillus subtilis was CCTCC AB130001, both of which were purchased from China Center for Type Culture Collection (CCTCC);
[0041] Knead until the tea juice overflows but does not drip.
[0042] Step S4, fermentation: placing the rolled quinoa leaves, the mixture of the mixed enzyme and the composite bacterial agent in an incubator for fermentation; the fermentation temperature is 29° C., and the fermentation time is 7 hours.
[0043] Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying, the drying temperature is 80° C., and the drying time is 3 hours; after the drying is completed, spreading them to room temperature to obtain quinoa black tea.
[0044] Embodiment 3:
[0045] A method for preparing quinoa black tea, characterized by comprising:
[0046] Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 52nd day after quinoa is planted;
[0047] Pre-treatment process: first, the harvested quinoa leaves are de-impurified to remove impurities contained in the quinoa leaves; then, the de-impurified quinoa leaves are soaked in clean water to clean the quinoa leaves.
[0048] Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering, the thickness of the quinoa leaves being 3.5 cm; the withering method is sunlight withering, the withering temperature is 27° C., and the withering time is 13 h, so that the moisture content is reduced to 77%;
[0049] Step S3, rolling: putting the wilted quinoa leaves into a rolling machine (the rolling machine can be a common rolling machine on the market in this field) and rolling them repeatedly for 32 minutes;
[0050] At the beginning of rolling, mixed enzyme and compound bacterial agent were added to the rolling machine simultaneously. The weight of wilting leaves, compound bacterial agent and mixed enzyme were 85g, 7g and 0.8g respectively. Among them, the mixed enzyme was a mixture of cellulase and pepsin, with a mass ratio of 1.2:1, the activity unit of cellulase was 5000-7500U / mg, and the activity unit of pepsin was 3000-3500U / mg; the compound bacterial agent was composed of Lactobacillus plantarum and Bacillus subtilis, with a mass ratio of 2.5:2, Lactobacillus plantarum was CCTCC AB 2011143, and Bacillus subtilis was CCTCC AB 130001, both of which were purchased from China Center for Type Culture Collection (CCTCC);
[0051] Knead until the tea juice overflows but does not drip.
[0052] Step S4, fermentation: placing the rolled quinoa leaves, the mixture of the mixed enzyme and the composite bacterial agent in an incubator for fermentation; the fermentation temperature is 30° C., and the fermentation time is 7.5 hours.
[0053] Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying, the drying temperature is 82° C., and the drying time is 3.3 h; after the drying is completed, spreading and airing to room temperature to obtain quinoa black tea.
[0054] Embodiment 4:
[0055] After the quinoa black tea is prepared in step S5 in the above implementation 1 to implementation 3, the quinoa black tea is also preserved, specifically, the prepared quinoa black tea is placed in a vacuum bag, and the vacuum bag is stored at a low temperature of 1 to 6° C. (preferably 3° C.).
[0056] Comparative Example 1:
[0057] A method for preparing quinoa black tea, characterized by comprising:
[0058] Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 50th day after quinoa planting;
[0059] Pre-treatment process: first, the harvested quinoa leaves are de-impurified to remove impurities contained in the quinoa leaves; then, the de-impurified quinoa leaves are soaked in clean water to clean the quinoa leaves.
[0060] Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering, the thickness of the quinoa leaves being 3 cm; the withering method is sunlight withering, the withering temperature is 25° C., and the withering time is 12 h, so that the moisture content is reduced to 76%;
[0061] Step S3, rolling: put the wilted quinoa leaves into a rolling machine (the rolling machine can be any common rolling machine on the market) and roll them repeatedly for 30 minutes; roll them until the tea juice overflows without dripping.
[0062] Step S4, fermentation: adding a mixed enzyme to the rolled quinoa leaves, the masses of the wilted leaves and the mixed enzyme are 75g and 0.7g respectively, the mixed enzyme is a mixture of cellulase and pepsin, the mass ratio is 1:1, the activity unit of cellulase is 5000-7500U / mg, and the activity unit of pepsin is 3000-3500U / mg; then placing the quinoa leaves containing the mixed enzyme in an incubator for fermentation; the fermentation temperature is 29°C, and the fermentation time is 7h.
[0063] Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying at 80°C for 3 hours; after drying, spreading and airing to room temperature to obtain quinoa black tea. Comparative Example 2:
[0064] A method for preparing quinoa black tea, characterized by comprising:
[0065] Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 50th day after quinoa planting;
[0066] Pre-treatment process: first, the harvested quinoa leaves are de-impurified to remove impurities contained in the quinoa leaves; then, the de-impurified quinoa leaves are soaked in clean water to clean the quinoa leaves.
[0067] Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering, the thickness of the quinoa leaves being 3 cm; the withering method is sunlight withering, the withering temperature is 25° C., and the withering time is 12 h, so that the moisture content is reduced to 76%;
[0068] Step S3, rolling: putting the wilted quinoa leaves into a rolling machine (the rolling machine can be a common rolling machine on the market in this field) and rolling them repeatedly for 30 minutes;
[0069] At the beginning of rolling, mixed enzyme and compound bacterial agent are added to the rolling machine simultaneously. The weight of wilting leaves, compound bacterial agent and mixed enzyme are 75g, 6g and 0.7g respectively. Among them, the mixed enzyme is a mixture of cellulase and trypsin, with a mass ratio of 1:1, the activity unit of cellulase is 5000-7500U / mg, and the activity unit of trypsin is 3000-4500U / mg; the compound bacterial agent is composed of Lactobacillus plantarum and Bacillus subtilis, with a mass ratio of 2:1.5, Lactobacillus plantarum is CCTCC AB 2011143, and Bacillus subtilis is CCTCC AB130001, both purchased from China Center for Type Culture Collection (CCTCC); rolling is performed until the tea juice overflows but does not drip.
[0070] Step S4, fermentation: placing the rolled quinoa leaves, the mixture of the mixed enzyme and the composite bacterial agent in an incubator for fermentation; the fermentation temperature is 29° C., and the fermentation time is 7 hours.
[0071] Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying, the drying temperature is 80° C., and the drying time is 3 hours; after the drying is completed, spreading them to room temperature to obtain quinoa black tea.
[0072] Test evaluation:
[0073] According to the method in GB 23776-2009 (tea sensory evaluation method), a sensory evaluation table was drawn as shown in Table 1, and the appearance, soup color, aroma, taste, and leaf bottom of the quinoa black tea samples obtained in Example 2 and Comparative Examples 1 to 2 were evaluated respectively (each factor was evaluated multiple times and the average value was taken. In this embodiment, each factor was evaluated 30 times respectively), and an evaluation result table was drawn as shown in Table 2. According to the judges' description of its quality characteristics, the scores of each item were recorded, and different weights were assigned to the five factors. The total evaluation score = appearance × 25% + soup color × 10% + aroma × 25% + taste × 30% + leaf bottom × 10%.
[0074] Table 1: Sensory evaluation table
[0075]
[0076]
[0077] Table 2: Evaluation results table:
[0078] Experimental Group shape Soup color aroma taste Leaf bottom Comprehensive score Example 2 98.3 98.8 98.5 98.9 98.7 98.62 Comparative Example 1 94.6 78.7 83.5 73.5 93.6 83.81 Comparative Example 2 95.2 90.5 95.4 87.1 94.9 92.32
[0079] It can be clearly seen from Tables 1 and 2 above that the addition of enzyme-bacteria in the rolling step makes the contact between the enzyme-bacteria and quinoa leaves more sufficient, and the quinoa black tea prepared under the synergistic effect of bacteria-enzyme has a soup color, aroma and taste that are significantly better than the method of adding enzymes in the fermentation step; in addition, by adding a combination of cellulase + pepsin + composite bacteria during the rolling process to complete the preparation of quinoa black tea, its soup color and taste are significantly better than the combination of cellulase + trypsin + composite bacteria, proving that the bacteria-enzyme synergistic effect of cellulase + pepsin + composite bacteria is more excellent, and can fully decompose the protein and ester macromolecular structure in quinoa leaves, thereby avoiding turbidity and bitterness of the tea soup and improving the drinking taste of the tea soup.
[0080] The following tests were performed on the quinoa black tea samples obtained in Example 2 and Comparative Examples 1 to 2: the crude fiber of tea was determined according to GBT 8310-2013 (determination of crude fiber of tea), the polyphenols were determined according to GBT8313-2008 (the method for detecting the content of tea polyphenols and catechins in tea leaves), the flavonoids were determined according to DB13T 385-1998 (determination of total flavonoids in food), and the soluble sugar content was determined at the same time:
[0081] The method for determining the content of soluble sugar is:
[0082] First, prepare a glucose standard curve: accurately weigh 100 mg of analytical pure anhydrous glucose, dissolve it in distilled water and make up to 100 ml, dilute it 10 times (100 ug / ml) when using; weigh 1.0 g of anthrone, dissolve it in 1000 ml of 80% concentrated sulfuric acid, cool it to room temperature, place it in a stoppered brown bottle, and store it in a refrigerator at 4°C, which can be used for 2 to 3 weeks; prepare test tubes of different glucose solutions, as shown in Table 3 below, shake each test tube quickly to mix, boil it in a boiling water bath for 10 minutes, take it out and cool it, measure the absorbance at a wavelength of 620 nm, and draw a glucose standard curve with optical density as the ordinate and glucose content as the abscissa.
[0083] Table 3: Plotting of glucose standard curve
[0084] Tube No. 1 2 3 4 5 6 Glucose solution (ml) 0 0.2 0.4 0.6 0.8 1.0 Distilled water (ml) 1.0 0.8 0.6 0.4 0.2 0 Anthrone reagent (ml) 5.0 5.0 5.0 5.0 5.0 5.0 Glucose content (ug) 0 20 40 60 80 100
[0085] Then, weigh 0.05 g of the sample, add 1 ml of distilled water, and place in a boiling water bath for 20 min. Take 0.1 ml of the supernatant, add 0.5 ml of anthrone reagent, mix well, and place in a boiling water bath for 10 min. Measure the absorbance at a wavelength of 620 nm.
[0086] Soluble sugar content (%) = C × V T / 10 6 W×V S×100%
[0087] Where: C represents the glucose content obtained from the standard curve; V T V represents the total volume of the sample extract; S Indicates the amount of sample liquid taken during color development; W indicates the sample weight.
[0088] The results of tea cellulose, tea polyphenols, flavonoids and soluble sugars finally obtained are shown in Table 4 below:
[0089] Table 4: Nutritional indicators of quinoa black tea
[0090]
[0091]
[0092] It can be clearly seen from the above table that the contents of tea cellulose, polysaccharides, polyphenols and red copper in quinoa black tea prepared by the method of the present application are higher than those obtained by adding enzymes during the fermentation process or by using a combination of cellulase + trypsin + composite bacterial agent during the rolling process.
[0093] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing quinoa black tea, characterized in that: include: Step S1, selection of raw materials: selecting quinoa leaves in full bloom as raw materials for tea making; wherein the full bloom period is the 48th to 52nd day after quinoa planting; Step S2, withering: spreading quinoa leaves in full bloom on a mesh screen and withering to reduce the moisture content to 75-77%; Step S3, rolling: putting the wilted quinoa leaves into a rolling machine for repeated rolling, and adding a mixed enzyme and a composite bacterial agent into the rolling machine at the beginning of rolling; The mass ratio of the wilting leaves, the composite bacterial agent and the mixed enzyme is 65-85:5-7:0.6-0.8; wherein the mixed enzyme is a mixture of cellulase and pepsin, and the composite bacterial agent is composed of plant lactobacillus and bacillus subtilis; the mass ratio of cellulase to pepsin is 0.8-1.2:1, the activity unit of cellulase is 5000-7500U / mg, and the activity unit of pepsin is 3000-3500U / mg; the mass ratio of plant lactobacillus and bacillus subtilis is 1.5-2.5:1-2; The kneading time is 28 to 32 minutes; Step S4, fermentation: placing the rolled quinoa leaves, the mixture of the mixed enzyme and the composite bacterial agent in an incubator for fermentation; Step S5, drying: placing the fermented quinoa leaves in a drying box for high-temperature drying. After drying, spreading them to room temperature to obtain quinoa black tea; the drying temperature is 78-82° C., and the drying time is 2.7-3.3 h.
2. The method for preparing quinoa black tea according to claim 1, characterized in that: After step S1 and before step S2, a pretreatment process of quinoa leaves is further performed, specifically: first, the harvested quinoa leaves are subjected to a de-impuration process to remove impurities contained in the quinoa leaves; then, the de-impuration quinoa leaves are soaked in clean water to achieve cleaning of the quinoa leaves.
3. The method for preparing quinoa black tea according to claim 1, characterized in that: In the step S2, the flattened thickness of the quinoa leaves is 2.5 to 3.5 cm, the withering time is 11 to 13 hours, the withering method is sunlight withering, and the withering temperature is 23 to 27°C.
4. The method for preparing quinoa black tea according to claim 1, characterized in that: After the quinoa black tea is prepared in step S5, the method further includes preserving the quinoa black tea, specifically, placing the prepared quinoa black tea in a vacuum bag, and storing the vacuum bag at a low temperature of 1 to 6°C.