Germinating highland barley tea and preparation method thereof

Abstract

The invention relates to the technical field of beverage processing and preparation, and discloses germinated highland barley tea and a preparation method thereof.The preparation method comprises the three steps of highland barley variety screening, germinated highland barley preparation and baking, through variety screening and standardized processing, the flavor and quality consistency of each batch of germinated highland barley tea products is guaranteed, and the quality of the germinated highland barley tea products is improved. By improving technological parameters of germination and baking of the highland barley, the loss amount of functional components of the highland barley in the tea making process is reduced, and the nutritional value and flavor of the highland barley tea are optimized. Compared with a commercially available highland barley tea product, the germinated highland barley tea provided by the invention has the advantages that the sensory quality and the nutritional value of the highland barley tea are remarkably improved, the germinated highland barley tea has unique grain fragrance and tea fragrance, also retains various functional components of highland barley, is a healthy beverage capable of helping consumers to improve blood sugar, regulate metabolism and improve oxidation resistance, and is suitable for popularization and application. And the market value is considerable.

Description

Technical Field

[0001] The invention relates to the technical field of beverage processing and preparation, and in particular to sprouted highland barley tea and a preparation method thereof. Background Art

[0002] As a traditional food crop, highland barley is the main food source in Tibetan areas. It has attracted much attention in recent years due to its unique nutritional value and health benefits. Highland barley is rich in β-glucan, dietary fiber, phenolic compounds and various minerals. Its functional ingredients show significant advantages in preventing chronic diseases, improving intestinal health and enhancing immunity. In addition, highland barley has good antioxidant activity and low glycemic properties, making it an important part of modern healthy diet. In recent years, with the increase in people's demand for healthy drinks, highland barley tea, as a functional drink rich in dietary fiber, polyphenols, β-glucan and trace elements, has gradually been favored by consumers.

[0003] Highland barley tea is a healthy drink made from highland barley through roasting, crushing and other processing techniques. Although highland barley tea has received more and more attention as a functional health drink in recent years, it still faces some problems in the development of the industry: traditional highland barley tea is generally made by tea workers based on experience, without unified standards, and the functional ingredients in highland barley are seriously lost during the tea making process, and the product quality is unstable, which affects the market promotion and industrial development of highland barley tea. Unifying the quality of highland barley tea will be conducive to the development of the highland barley tea industry. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a sprouted highland barley tea and a preparation method thereof, optimize the nutritional value of existing highland barley tea, ensure the flavor and quality consistency of highland barley tea, and promote the development of the highland barley tea industry.

[0005] To achieve the above object, the present invention provides the following technical solutions.

[0006] In a first aspect, the present invention provides a method for preparing sprouted highland barley tea, which comprises the following steps:

[0007] Step 1, screening of highland barley varieties: roasting highland barley seeds of different varieties at 180° C. for 16 min to obtain highland barley tea, detecting the polyphenol content of each variety of highland barley tea, and selecting highland barley varieties with a highland barley tea polyphenol content of 200-250 mg / 100 g as raw materials for preparing sprouted highland barley tea;

[0008] Step 2, preparation of sprouted highland barley: after cleaning, impurity removal and disinfection, the highland barley seeds selected in step 1 are placed in a constant temperature water bath at 20° C. and soaked for 14 h, taken out, and the soaked highland barley seeds are placed under germination conditions of temperature 25° C. and humidity 95% for germination for 24-40 h, and then dried at 80° C. for 2 h to obtain sprouted highland barley;

[0009] Step 3, baking: baking the sprouted highland barley obtained in step 2 at 160-180° C. for 14-16 min to obtain sprouted highland barley tea.

[0010] Furthermore, in step 1, a highland barley variety with a highland barley tea polyphenol content of 220-230 mg / 100 g is selected as the raw material for preparing sprouted highland barley tea. More preferably, the highland barley variety is selected from Kangding black highland barley.

[0011] Furthermore, the disinfection method in step 2 is to soak the highland barley seeds in a 5% by volume sodium hypochlorite solution for 15 minutes and then wash them with clean water until they are neutral.

[0012] Furthermore, the germination time of highland barley seeds in step 2 is 40 hours.

[0013] Furthermore, the roasting temperature of the germinated barley in step 3 is 170°C.

[0014] Furthermore, the roasting time of the germinated highland barley in step 3 is 15 minutes.

[0015] In a second aspect, the present invention also provides sprouted highland barley tea prepared by the above-mentioned preparation method.

[0016] Existing studies have shown that sprouting can decompose macromolecular substances such as starch, fat, and protein in cereals into small molecular metabolites that are easier for human body to absorb and metabolize, significantly affecting the physicochemical properties of cereals. The sprouted highland barley has a significant change in both the nutritional components and the physicochemical structure of highland barley due to the increase in water content and the acceleration of cell metabolism. Compared with unsprouted highland barley, the sprouted highland barley has better nutritional components, palatability, and digestibility, and its antioxidant activity, health-promoting effects, etc. are also improved. The present invention reduces the loss of functional components (polyphenols, β-glucan, etc.) of highland barley during the tea making process through the improvement of highland barley sprouting and baking process parameters, optimizes the nutritional value of highland barley tea, and optimizes the flavor of highland barley tea, so that it has a unique cereal aroma and tea fragrance, which conforms to the taste of the public.

[0017] As is known to all, highland barley is rich in β-glucan, dietary fiber, phenolic compounds and various minerals. The chemical components contained in it will affect the quality of highland barley tea. For example, polyphenols will give tea a distinct bitter taste, but at the same time, in the process of tea tasting, the mixture of polyphenols and saliva in the mouth will produce a pleasant sweet aftertaste after the bitterness; at the same time, the polyphenol content often also affects the color of the tea soup. Polyphenols undergo oxidative polymerization under the action of oxidase to form theaflavins and thearubigins, which make the color of the tea soup darker; at the same time, high content of polyphenols will make tea have a strong astringency, and after drinking, the mouth will feel a certain dryness. In the process of the present invention, it is found that highland barley tea prepared from different varieties of highland barley has significant differences in sensory characteristics, polyphenol content and antioxidant activity, which also leads to the quality difference of existing highland barley tea. The present invention selects a specific highland barley variety to prepare sprouting highland barley tea through variety screening, thereby ensuring the quality consistency of sprouting highland barley tea. The germination process usually activates the biochemical metabolism of seeds, significantly enhancing the activity of their internal enzymes. For example, the activity of polyphenol oxidase and peroxidase may affect the synthesis and accumulation of polyphenol compounds. Germination may also promote the synthesis of secondary metabolites. Therefore, during the germination of highland barley, due to enzymatic action and metabolic changes, the synthesis of polyphenols and other antioxidant components may be significantly enhanced, and flavor substances such as amino acids, organic acids and soluble sugars may accumulate or transform, thereby affecting the component content of the final tea product. The variety screening method and standard provided by the present invention not only ensure the nutritional value of germinating highland barley tea, but also ensure that its sensory quality meets the taste of the public.

[0018] In the current highland barley tea processing technology, the roasting process plays a key role in the flavor and functional components of the product, but the products on the market lack unified standards in process parameters such as roasting temperature and time, resulting in unstable product quality. For example, most traditional highland barley teas are over-roasted, resulting in the loss of functional components such as polyphenols and β-glucan. During the processing of the budding highland barley tea of ​​the present invention, the roasting conditions are optimized through scientific experiments, the roasting temperature and time are strictly controlled, and the maximum retention of highland barley polyphenols and other functional components is ensured, while giving the tea a unique aroma and taste.

[0019] Compared with the prior art, the preparation method provided by the present invention ensures the consistency of flavor and quality of each batch of sprouting highland barley tea products through variety screening and standardized processing. Compared with commercially available highland barley tea products, the sprouting highland barley tea provided by the present invention significantly improves the sensory quality and nutritional value of highland barley tea, has a unique cereal aroma and tea aroma, and retains a variety of functional ingredients of highland barley. It is a healthy drink that can help consumers improve blood sugar, regulate metabolism, and enhance antioxidant capacity, meets the needs of modern consumers for healthy drinks, and has considerable market value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a bar graph of sensory evaluation results of Ganqing No. 10 tea made at different roasting temperatures and times in Example 1 of the present invention;

[0021] Figure 2 The tea soup pictures of different varieties of highland barley tea in Example 1 of the present invention;

[0022] Figure 3 The radar chart of sensory evaluation of different varieties of highland barley tea in Example 1 of the present invention;

[0023] Figure 4 The bar graph is a sensory evaluation result bar graph of different varieties of highland barley tea in Example 1 of the present invention;

[0024] Figure 5 The electronic tongue analysis diagrams of different varieties of highland barley tea in Example 1 of the present invention (A is a radar diagram, B is a PCA diagram, and C is a loading diagram);

[0025] Figure 6 The electronic nose analysis diagrams of different varieties of highland barley tea in Example 1 of the present invention (A is a radar diagram, B is a PCA diagram, and C is a loading diagram);

[0026] Figure 7 The electronic eye PCA analysis diagram of different varieties of highland barley tea in Example 1 of the present invention;

[0027] Figure 8 The polyphenol content bar graph of different varieties of highland barley tea in Example 1 of the present invention;

[0028] Fig. 9 is the DPPH free radical scavenging ability of different varieties of highland barley tea in Example 1 of the present invention;

[0029] Fig.10 is the ABTS free radical scavenging ability of different varieties of highland barley tea in Example 1 of the present invention;

[0030] Fig.11 This is a PCA analysis diagram of the electronic nose of different highland barley teas in Example 3 of the present invention;

[0031] Fig.12 This is the electronic tongue PCA analysis diagram of different highland barley teas in Example 3 of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific embodiments.

[0033] Example 1: Screening of raw materials for preparing budding highland barley tea

[0034] 1.1 Test materials

[0035] The information of the test raw materials is shown in Table 1 below, and commercially available highland barley tea (manufacturer: Tibet Zangbenxiang Industrial Co., Ltd., product name: highland barley tea) is used as a control.

[0036] Table 1. Raw materials for preparing budding highland barley tea

[0037] Barley No. Highland barley varieties Harvest location Harvest time 1 Yun Beer Wheat No. 8 Daofu County, Ganzi Prefecture August 2023 2 Himalaya 23 Daofu County, Ganzi Prefecture August 2023 3 Himalaya 19 Daofu County, Ganzi Prefecture August 2023 4 Kunlun 15 Daofu County, Ganzi Prefecture August 2023 5 Kunlun 14 Daofu County, Ganzi Prefecture August 2023 6 Kangqingnuo No.3 Daofu County, Ganzi Prefecture August 2023 7 Kangqingnuo No.1 Daofu County, Ganzi Prefecture August 2023 8 Kangqing No. 9 Daofu County, Ganzi Prefecture August 2023 9 Kangqing 1325 Daofu County, Ganzi Prefecture August 2023 10 Kangqing1282 Daofu County, Ganzi Prefecture August 2023 11 Kangqing1277 Daofu County, Ganzi Prefecture August 2023 12 Kangqing 125 Daofu County, Ganzi Prefecture August 2023 13 Kang Qing 11 Daofu County, Ganzi Prefecture August 2023 14 Kangding Black Barley Kangding City, Ganzi Prefecture August 2023 15 Ganqing No.9 Daofu County, Ganzi Prefecture August 2023 16 Navy 2000 Daofu County, Ganzi Prefecture August 2023 17 Navy 17 Daofu County, Ganzi Prefecture August 2023 18 Ai Qing 3000 Daofu County, Ganzi Prefecture August 2023 19 Ai Qing17 Daofu County, Ganzi Prefecture August 2023 20 Ganqing No. 10 Daofu County, Ganzi Prefecture August 2023

[0038] 1.2 Screening mechanism: After different varieties of highland barley are roasted to make tea, the sensory characteristics, polyphenol content and antioxidant activity of highland barley tea made from different varieties of highland barley are analyzed using advanced technologies such as electronic nose, electronic eye and electronic tongue, combined with traditional sensory evaluation methods, and the varieties with the best performance in sensory scoring and quality testing are selected as the raw materials for preparing budding highland barley tea.

[0039] Since roasting plays a key role in the flavor and functional components of the product, it is necessary to first determine the parameters for roasting highland barley tea, and select Ganqing No. 10 with good yield performance to optimize the roasting conditions. Select highland barley seeds with full grain shape, no pests and diseases, and no impurities, and rinse them repeatedly with clean water to remove surface dust and impurities. The cleaned highland barley is placed in an 80℃ oven for pre-drying for 2h. A single factor experiment was used to investigate the effects of roasting temperature (160℃, 180℃, 200℃) and roasting time (12min, 14min, 16min) on the sensory quality of highland barley tea, and the optimal process parameters were determined through sensory evaluation.

[0040] The sensory evaluation method refers to GB / T 23776-2018 "Tea Sensory Evaluation Method" with slight modifications. For details, see Table 2 below.

[0041] Table 2. Sensory evaluation standards for highland barley tea

[0042]

[0043] See also Figure 1 The sensory score results shown in the figure show that when the roasting temperature is 180℃ and the roasting time is 16min, the comprehensive sensory score of highland barley tea soup is the best. Therefore, the roasting temperature of 180℃ and the roasting time of 16min are selected as the optimal preparation process parameters of highland barley tea for variety screening.

[0044] 1.3 Electronic tongue analysis

[0045] Take 5g of highland barley tea, add boiling hot water according to the material-liquid ratio of 1:20 (w / w), brew for 10 minutes, and get highland barley tea soup. After filtering, pour into the measuring cup and use the electronic tongue to measure the taste. The taste indicators measured include sourness, sweetness, bitterness, saltiness, umami, universal, etc., and different sensors are used to measure the taste. Electronic tongue program parameters: electrode cleaning 90s; buffer cleaning 120s; buffer cleaning 120s; stabilization 30s; test sample 30s; buffer cleaning 3s; buffer cleaning 3s; aftertaste measurement 30s. Each sample was measured 5 times in a cycle, and the data of 2, 3, and 4 times were taken for result analysis. The sensor performance is shown in Table 3 below.

[0046] Table 3. Electronic tongue sensor performance table

[0047]

[0048]

[0049] 1.4 Electronic nose analysis

[0050] 5 mL of highland barley tea soup was placed in a 20 mL headspace bottle. The detection parameters were as follows: cleaning time 90 s; detection time 150 s; carrier gas 500 mL / min. Each sample was repeated 5 times, and the average of the three experiments was taken for calculation. The flavor was measured using different sensors, and the sensor performance is shown in Table 4 below.

[0051] Table 4. Electronic nose sensor performance table

[0052] serial number name Sensor response characteristics 1 W1C Sensitive to aromatic compounds 2 W5S Sensitive to nitrogen oxides 3 W3C Sensitive to ammonia and aromatic compounds 4 W6S Selective for hydrides 5 W5C Sensitive to alkanes and aromatic compounds 6 W1S Sensitive to methyl 7 W1W Sensitive to inorganic sulfides 8 W2S Sensitive to alcohols and some aromatic compounds 9 W2W Sensitive to aromatic compounds and organic sulfides 10 W3S Sensitive to long chain alkanes

[0053] 1.5 Electronic Eye Analysis

[0054] Measuring the color of highland barley tea with an electronic eye is a non-contact method based on machine vision technology. This method can quickly and accurately quantify the color characteristics of highland barley tea, avoid the influence of artificial color difference, and help evaluate the quality and stability of tea processing. Take 20mL of highland barley tea supernatant in a teacup, place the teacup on the camera box, and each variety contains 3 batches. After the electronic eye is turned on, stabilize it for 15 minutes to make the light source without deviation, and start using it when the light turns green. Use a 24-color color correction plate to calibrate the lens exposure and focal length, the aperture is 5mm, the light source is D65, and the top light source is turned on to eliminate the background. Take 10mL of highland barley tea sample and test it in a designated container. Extract the characteristic information of the center circle of the image from the collected image, and record the color number that accounts for more than 1% as the analysis data.

[0055] 1.6 Determination of total phenol content

[0056] The total phenol content of plants was determined using a plant total phenol content detection kit. After the highland barley tea was pulverized, it was passed through a 60-mesh sieve and the total phenol content was determined according to the instructions. Each sample was measured three times in parallel.

[0057] 1.7 Determination of antioxidant capacity

[0058] (1) Preparation of sample solution

[0059] After highland barley tea is powdered, it is passed through a 60-mesh sieve. 0.5 g of sample powder is accurately weighed into a 50 mL centrifuge tube. 30 mL of 70% methanol solution is added. Ultrasonic extraction is performed at 100 Hz for 30 min at room temperature. Centrifuge at 4000 r / min for 10 min, and the supernatant extract is collected. The sample residue is extracted twice under the same conditions. The supernatant extracts of three times are combined and fixed to 100 mL with 70% methanol solution to prepare a 5 mg / mL sample test solution.

[0060] (2) Determination of DPPH free radical scavenging rate

[0061] Take 2mL of the sample solution, add 2mL of DPPH solution, shake thoroughly and react in the dark for 30min, measure the absorbance at 517nm wavelength and record it as Ai, replace the DPPH solution with 2mL of extract solution, measure the absorbance in the same way and record it as Aj, replace the solution to be tested with 2mL of extract solution and measure the absorbance in the same way and record it as Ac. Three parallel groups were set up for each experiment, with commercial highland barley tea as the control, and the DPPH free radical scavenging rate was calculated according to formula (1):

[0062]

[0063] Ai——absorbance value of 2mL sample solution + 2mL DPPH solution;

[0064] Aj——absorbance value of 2mL sample solution + 2mL extract solution;

[0065] Ac——absorbance value of 2mL extract + 2mL DPPH solution.

[0066] (3) Determination of ABTS free radical scavenging rate

[0067] Preparation of ABTS working solution: 7mmol / L ATBS solution and 2.5mol / mL potassium persulfate solution were mixed in equal proportions, and allowed to stand at room temperature in the dark for 24h to prepare ABTS mother solution. Take an appropriate amount of mother solution and dilute it with 95% ethanol to an absorbance of 0.70±0.02 (λ=734nm), which is the ABTS working solution, which is prepared on demand. Take 0.1mL of the sample solution to be tested, add 3.9mL of ABTS solution, shake well and react in the dark for 6min, measure the absorbance at 734nm wavelength and record it as Ai, replace ABTS solution with 3.9mL of extract solution and measure the absorbance with the same method and record it as Aj, replace the solution to be tested with 0.1mL of extract solution and measure the absorbance with the same method and record it as Ac. Each group of experiments was tested three times in parallel, with commercial highland barley tea as the reference. Calculate the ABTS free radical scavenging rate of the sample according to formula (2).

[0068]

[0069] Ai——absorbance value of 0.1mL sample solution + 3.9mL ABTS solution;

[0070] Aj——absorbance value of 0.1mL sample solution + 3.9mL extract solution;

[0071] Ac——absorbance value of 0.1mL extract + 3.9mL ABTS solution.

[0072] 1.8 Analysis results

[0073] See also Figures 2 to 10 As shown in the results, different varieties of highland barley tea have significant differences in aroma, taste, soup color, polyphenol content and antioxidant capacity. Kangding black highland barley performed best in the sensory evaluation, and became the best raw material choice for Mengdong highland barley tea with its unique flavor, color, suitable polyphenol content and antioxidant capacity.

[0074] Example 2: Optimization of processing technology for sprouting highland barley tea

[0075] Experimental method: Using Kangding black highland barley as raw material, sprouting highland barley tea was prepared according to the following preparation process. Taking sensory evaluation (Table 2), polyphenol content, and γ-aminobutyric acid (GABA) content as indicators, the effects of germination time, baking temperature, and baking time on sprouting highland barley tea were investigated to determine the appropriate process parameters for the preparation of sprouting highland barley tea. Finally, it was determined that germination time 24-40h, baking temperature 160-180℃, and baking time 14-16min were the preparation process parameters for sprouting highland barley tea, and the optimal process parameters were germination time 40h, baking temperature 170℃, and baking time 15min. At this time, the tea soup flavor was the best, and the relevant nutritional components of the tea soup were retained to the greatest extent.

[0076] The preparation process of budding highland barley tea is as follows: select highland barley seeds with full grain shape, no pests and diseases, and no impurities, and rinse them repeatedly with clean water to remove surface dust and impurities; place the cleaned highland barley seeds in a sodium hypochlorite solution with a volume fraction of 5% and soak for 15min, then wash with clean water to neutrality for disinfection; place the disinfected highland barley seeds in a constant temperature water bath at 20℃ and soak for 14h, take out, place the soaked highland barley seeds in a constant temperature and humidity incubator with a temperature of 25℃ and a humidity of 95% for a specific time (8h, 16h, 24h, 24h, 32h, 40h), and then dry them (80℃, 2h), and the budding highland barley seeds after drying are baked to change the color of the highland barley into golden yellow, while stimulating its unique aroma. The baked highland barley needs to be sealed and packaged after natural cooling to reduce the risk of oxidation and moisture.

[0077] Example 3: Effect of germination process and highland barley varieties on the quality of highland barley tea products

[0078] Test method:

[0079] 1. Using Kangding black highland barley as raw material, highland barley tea was prepared according to the preparation process of Example 1 (baking temperature 180° C., baking time 16 min); and germination highland barley tea was prepared according to the preparation process of Example 2 (germination time 40 h, baking temperature 170° C., baking time 15 min).

[0080] 2. Using Kangqing 125 and Kunlun 14 as raw materials, highland barley tea was prepared according to the preparation process of Example 1 (baking temperature 180° C., baking time 16 min).

[0081] 3. The prepared highland barley tea and sprouted highland barley tea were scored by traditional sensory evaluation, and their polyphenol content, γ-aminobutyric acid (GABA) content, β-glucan content and antioxidant capacity were detected, and compared with commercially available highland barley tea (manufactured by Tibet Zangbenxiang Industrial Co., Ltd.), as shown in Table 5 below. Among them, the content of γ-aminobutyric acid (GABA) was determined by a γ-aminobutyric acid (GABA) colorimetric test kit; the content of β-glucan was determined by a Megazyme mixed β-glucan detection kit.

[0082] Table 5. Evaluation results of highland barley tea prepared from different varieties of highland barley

[0083]

[0084] As can be seen from Table 5 above, the polyphenol and GABA contents and free radical scavenging rate of sprouted barley tea are higher than those of unsprouted barley tea. This may be because during the germination of barley, the activation of enzymatic reactions promotes the accumulation of antioxidants, such as polyphenols, GABA and other secondary metabolites, thereby enhancing their ability to scavenge free radicals, making sprouted barley tea have higher functional value; and the β-glucan content of sprouted barley tea is slightly lower than that of barley tea, which may be because the germination process leads to partial degradation or conversion of β-glucan, but germination also promotes the accumulation of other functional components (such as polyphenols and GABA). In summary, the advantages of sprouted barley in making tea are more obvious than those of unsprouted barley.

[0085] The electronic nose and electronic tongue analysis of Kangding black barley tea, budding barley tea and commercially available barley tea were performed. Fig.11 and Fig.12 shown. Fig.11 Used to analyze the overall differences in volatile substances among samples, from Fig.11 As can be seen in the figure, the first principal component (PC1) explains 99.99% of the variation in the data, indicating that PC1 is the main variable that distinguishes the samples, while the contribution of the second principal component (PC2) is smaller, only 0.01%. Fig.11 In the figure, sprouted highland barley tea (red dots) formed clearly separated cluster groups from commercially available highland barley tea (green dots) and highland barley tea (purple dots) in the PCA space, indicating that there were significant differences in their volatile component composition, and the differences were large enough to be significantly distinguished by electronic nose technology. This may be because the germination process causes changes in the volatile components of tea, thus presenting different odor characteristics. Fig.12 Used to compare the differences in taste attributes of each sample tea. Fig.12 From the above, we can see that the first principal component (PC1) explains 99.89% of the variance and is the main distinguishing factor, while the second principal component (PC2) only explains 0.1% of the variance. Fig.12 In the data, the sprouted barley tea (red dots) and the commercially available barley tea (green dots) and barley tea (purple dots) formed clearly separated cluster groups in the PCA space, indicating that their taste characteristics were significantly different. This may be because the sprouting process may have triggered a series of metabolic changes, such as the accumulation or transformation of flavor substances such as amino acids, organic acids and soluble sugars, which made the sprouted barley tea present a richer or unique taste attribute. The commercially available barley tea may have retained more original flavor or simple sweet characteristics during processing.

[0086] Too high or too low a polyphenol content will affect the overall flavor of the tea, see Table 5 for the highland barley tea of ​​Kangqing 125 and Kunlun 14 varieties, but the highland barley germination process may cause changes in the volatile components of the highland barley tea, and germination may also promote the accumulation or conversion of flavor substances such as amino acids, organic acids and soluble sugars, making the highland barley germination tea present a richer or unique taste attribute. Therefore, the present invention not only increases the polyphenol content of the tea through highland barley germination, but also optimizes the flavor of the highland barley tea. Taking the highland barley tea polyphenol content (221.70 mg / 100 g) of the best raw material Kangding black highland barley as the standard, the present invention determines that highland barley varieties with a highland barley tea polyphenol content in the range of 200-250 mg / 100 g are suitable as the raw materials for preparing sprouting highland barley tea, and more preferably, highland barley varieties with a highland barley tea polyphenol content in the range of 220-230 mg / 100 g are selected as the raw materials for preparing sprouting highland barley tea.

[0087] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing sprouted highland barley tea, characterized in that: The following steps are involved: Step 1, screening of highland barley varieties: roasting highland barley seeds of different varieties at 180° C. for 16 min to obtain highland barley tea, detecting the polyphenol content of each variety of highland barley tea, and selecting highland barley varieties with a highland barley tea polyphenol content of 200-250 mg / 100 g as raw materials for preparing sprouted highland barley tea; Step 2, preparation of sprouted highland barley: after cleaning, impurity removal and disinfection, the highland barley seeds selected in step 1 are placed in a constant temperature water bath at 20° C. and soaked for 14 h, taken out, and the soaked highland barley seeds are placed under germination conditions of temperature 25° C. and humidity 95% for germination for 24-40 h, and then dried at 80° C. for 2 h to obtain sprouted highland barley; Step 3, baking: baking the sprouted highland barley obtained in step 2 at 160-180° C. for 14-16 min to obtain sprouted highland barley tea.

2. The preparation method according to claim 1, characterized in that: In the step 1, a highland barley variety with a highland barley tea polyphenol content of 220-230 mg / 100 g is selected as the raw material for preparing sprouted highland barley tea.

3. The preparation method according to claim 2, characterized in that: The highland barley variety is selected from Kangding black highland barley.

4. The preparation method according to claim 1, characterized in that: The disinfection method in step 2 is to soak the highland barley seeds in a 5% by volume sodium hypochlorite solution for 15 minutes and then wash them with clean water until they are neutral.

5. The preparation method according to claim 1, characterized in that: The germination time of highland barley seeds in step 2 is 40 hours.

6. The preparation method according to claim 1, characterized in that: The baking temperature of the germinated highland barley in step 3 is 170°C.

7. The preparation method according to claim 1, characterized in that: The baking time of the sprouted highland barley in step 3 is 15 minutes.

8. A sprouting highland barley tea, characterized in that: The preparation method is described in any one of claims 1 to 7.

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