A kind of tea juice and its preparation method and application

Abstract

The present invention provides a sencha tea juice and a preparation method and application thereof, wherein the preparation method comprises: subjecting tea leaves to aroma treatment to obtain sencha tea leaves; subjecting the sencha tea leaves to primary extraction and secondary extraction under anaerobic conditions, combining the extracts of the two extractions to obtain the sencha tea juice, wherein the extractant used in the primary extraction and the secondary extraction is an antioxidant aqueous solution. The sencha tea juice obtained by the preparation method provided by the present invention has a strong aroma, a sweet and rich taste, no heavy bitter taste and earthy taste, a mellow and clean taste, and can achieve the best tea juice flavor; and the sencha milk tea beverage made with the sencha tea juice as the main raw material has a long shelf life under room temperature storage conditions, while ensuring that the tea aroma therein is stable without fission, providing consumers with excellent quality.

Description

Technical Field

[0001] The invention belongs to the technical field of milk tea beverages, and in particular relates to a decocted tea juice and a preparation method and application thereof. Background Art

[0002] After nearly a decade of rapid development, the milk tea market has reached tens of billions of annual sales, and different products need to be developed to meet the growing needs of consumers. Green tea is divided into stir-fried green tea, baked green tea, steamed green tea, and sun-dried green tea according to the production process; in the production process of green tea, steam killing has been used in the production process of green tea as early as the Tang Dynasty. At that time, steamed green tea was steamed green cake tea. Later, the tea making method of steam killing was spread to Japan and has been used to this day, developing into Japan's steamed green tea, among which the main product is steamed green sencha. Since then, sencha has gradually been used to refer to a variety of tea, that is, green tea made by steam killing. The production process of steamed green tea includes: using fresh leaves and tender stems of tea trees as raw materials, and making tea products through steam killing, rolling, drying, and molding. Using steamed green tea as raw material, after being processed into a blank, the steamed green tea is then processed by special infrared aroma equipment to form a unique steamed green sencha tea, which is made into a unique flavor sencha milk green beverage with related dairy products, oils, sugars, etc.

[0003] Green tea-based milk tea is different from black tea-based milk tea. It has the fragrance of jasmine and is refreshing without being greasy. It is the choice of more consumers. The number of green milk tea products is increasing and it is becoming more and more popular among consumers. Its mellow milk flavor and natural and refreshing tea aroma and tea feel bring more taste satisfaction to consumers.

[0004] CN103918791A discloses a green tea milk tea and a preparation method thereof. The green tea milk tea has the following raw material formula: by weight percentage, 20%-30% green tea juice, 1.5%-3% milk powder, 3%-6% non-dairy creamer, 5%-7% white sugar, 0.06%-0.2% emulsifier, 0.02%-0.06% antioxidant, 0.02%-0.06% color retainer, 0.02%-0.05% acidity regulator, 0.06%-0.2% edible flavor and the balance RO water; wherein The green tea juice is prepared by an extraction method using a mixture of steamed green tea leaves and jasmine tea leaves, and based on the total weight of the green tea milk tea raw material, the weight percentage of the steamed green tea leaves is 0.3%-1.0%, the weight percentage of the jasmine tea leaves is 0.3%-1.0%, and the material-water ratio of the mixed tea leaves to the RO water solvent in the extraction stage is 1:30-50; the green tea milk tea prepared by the method has a color and flavor stability at room temperature that is far superior to the current commercially available green tea milk tea, and has a longer shelf life.

[0005] During the production of green milk tea, there are two major problems with the product: 1) Tea polyphenols such as catechins in green tea leaves contain multiple hydroxyl groups and are highly reducing, so they are easily oxidized and polymerized with highly oxidizing substances. Therefore, they are easily oxidized and turned red due to the influence of multiple factors such as oxygen, light, moisture, temperature and other conditions. The higher the ambient temperature, the more intense the oxidation, resulting in the system to form brown and reddish brown discoloration. The green milk tea produced has a large color change during the shelf life and serious browning. 2) Due to the low solubility of green tea, after adding dairy raw materials, the flavor is low, and the tea feeling and tea aroma are not easy to express. During the production process, the extraction time and extraction temperature are usually increased to improve the tea feeling, which leads to excessive dissolution of caffeine, tea polyphenols, and colloid substances in the green tea juice, which are easily combined with proteins. During the high-temperature sterilization stage of production, the product sterilization tube is prone to scaling, which requires continuous shutdown and cleaning, and cannot be continuously produced for a long time, resulting in low production efficiency and other problems.

[0006] Therefore, developing a tea juice preparation process that can effectively enhance the tea taste and tea aroma in milk tea, and this process can improve the efficiency of actual processing and production, is a research focus in this field. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a tea juice for decocting and a preparation method and application thereof, which can effectively enhance the tea taste and tea aroma in the beverage.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing sencha tea juice, the method comprising: subjecting tea leaves to aroma treatment to obtain sencha tea leaves; subjecting the sencha tea leaves to primary extraction and secondary extraction under anaerobic conditions, combining the extracts of the two extractions to obtain the sencha tea juice;

[0010] The extractants used in the primary extraction and the secondary extraction are antioxidant aqueous solutions.

[0011] The tea juice provided by the present invention is extracted in an oxygen-free environment, thereby preventing the tea aroma from changing and the nutritional components such as tea polyphenols from being oxidized and discolored. At the same time, the extractants for the two extractions are both antioxidant aqueous solutions, thereby further preventing the effective components in the tea from being oxidized and keeping the tea juice bright in color.

[0012] Preferably, the tea leaves are green tea leaves.

[0013] Preferably, the aroma treatment method comprises: subjecting the tea leaves to microwave and infrared treatment.

[0014] Preferably, the frequency of the microwave is 3000-4000 MHz, for example, 3200 MHz, 3400 MHz, 3600 MHz or 3800 MHz, etc., and the duration is 2-3 h, for example, 2.2 h, 2.4 h, 2.6 h or 2.8 h, etc.

[0015] Preferably, the infrared wavelength is 50-100 μm, such as 60 μm, 70 μm, 80 μm or 90 μm, etc., and the time is 1-2 h, such as 2.2 h, 2.4 h, 2.6 h or 2.8 h, etc.

[0016] Preferably, the aroma treatment further includes a rinsing step.

[0017] Preferably, the flushing agent is a vitamin C aqueous solution.

[0018] Preferably, the solvent of the vitamin C aqueous solution is RO water.

[0019] Preferably, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, for example, it can be 60 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, 350 ppm or 380 ppm.

[0020] Preferably, the temperature of the flushing agent is 10-60°C, for example, it can be 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C or 55°C.

[0021] Preferably, the mass ratio of the flushing agent to the tea leaves is (1-2):1, for example, it can be 1.2:1, 1.4:1, 1.6:1 or 1.8:1, etc.

[0022] Preferably, the flushing is performed in an oxygen-free environment.

[0023] The present invention performs a rinsing step after aroma treatment, which can effectively remove foreign flavors in the tea leaves.

[0024] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0025] Preferably, the pressure of the primary extraction is 1-9 bar, for example, 2 bar, 3 bar, 4 bar, 5 bar, 6 bar, 7 bar or 8 bar.

[0026] Preferably, the primary extraction is performed by infiltration.

[0027] Preferably, the extraction time is 1-20 min, for example, 2 min, 4 min, 6 min, 8 min, 10 min, 12 min, 14 min, 16 min or 18 min.

[0028] Preferably, the extractant for the primary extraction is a vitamin C aqueous solution.

[0029] Preferably, the solvent of the vitamin C aqueous solution is RO water.

[0030] Preferably, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, for example, it can be 60 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, 350 ppm or 380 ppm.

[0031] Preferably, the temperature of the extractant is 45-75°C, for example, 50°C, 60°C, 65°C or 70°C.

[0032] Preferably, the mass ratio of the extractant to the sencha tea leaves is (10-30):1, for example, it can be 15:1, 20:1 or 25:1, etc.

[0033] The present invention adopts a low-temperature and high-pressure method during the primary extraction, and can effectively extract the aroma and heat-labile components in the tea leaves.

[0034] Preferably, the secondary extraction is carried out by spraying and extracting.

[0035] Preferably, the secondary extraction time is 1-6 min, for example, 2 min, 3 min or 5 min.

[0036] Preferably, the extractant for the secondary extraction is a vitamin C aqueous solution.

[0037] Preferably, the solvent of the vitamin C aqueous solution is RO water.

[0038] Preferably, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, for example, it can be 60 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, 350 ppm or 380 ppm.

[0039] Preferably, the temperature of the extractant is 75-90°C, for example, 80°C, 85°C or 88°C.

[0040] Preferably, the mass ratio of the extractant to the sencha tea leaves is (1-10):1, for example, 2:1, 4:1, 6:1 or 8:1.

[0041] The invention adopts a high temperature and short time mode in the secondary extraction, which can effectively extract caffeine, fat-soluble tea polyphenols and other components in tea leaves.

[0042] Preferably, the step of combining the extracts from the two extractions further includes a solid-liquid separation step.

[0043] Preferably, the solid-liquid separation includes primary separation and secondary separation performed sequentially.

[0044] Preferably, the primary separation is performed by centrifugation.

[0045] Preferably, the centrifugal rotation speed is 5000-8000 rpm, for example, it can be 5500 rpm, 6000 rpm, 6500 rpm, 7000 rpm or 7500 rpm.

[0046] Preferably, the secondary separation is performed by filtration.

[0047] Preferably, the pore size of the filter paper for filtration is 0.5-1 μm, for example, 0.5 μm or 1.0 μm.

[0048] Preferably, the decocted tea juice is stored at 4-15°C, for example, 6°C, 8°C, 10°C, 11°C, 12°C or 14°C.

[0049] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0050] Preferably, the preparation process comprises the following steps:

[0051] (1) extracting aroma and washing green tea leaves in sequence to obtain sencha tea leaves;

[0052] The aroma treatment is to subject the tea leaves to microwave and infrared treatment, the rinsing agent is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the rinsing agent is 10-60° C., the mass ratio of the rinsing agent to the tea leaves is (1-2):1, and the rinsing is performed in an anaerobic environment;

[0053] (2) extracting the sencha tea leaves once;

[0054] The primary extraction is carried out in an oxygen-free environment, the pressure of the primary extraction is 1-9 bar, the primary extraction is carried out in an infiltration manner, the time is 1-20 min, the extractant is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the extractant is 45-75° C., and the mass ratio of the extractant to the sencha tea leaves is (10-30):1;

[0055] (3) subjecting the brewed tea leaves obtained in step (2) to secondary extraction;

[0056] The secondary extraction is carried out in an oxygen-free environment, the secondary extraction is carried out by spraying and extracting, the time is 1-6 minutes, the extractant is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400ppm, the temperature of the extractant is 75-90°C, and the mass ratio of the extractant to the sencha tea leaves is (1-10):1;

[0057] (4) combining the extracts obtained from the primary extraction and the secondary extraction, and then performing solid-liquid separation to obtain the decocted tea juice;

[0058] The solid-liquid separation includes primary separation and secondary separation. The primary separation is performed by centrifugation at a rotation speed of 5000-8000 rpm. The secondary separation is performed by filtration at a pore size of 0.5-1 μm.

[0059] In a second aspect, the present invention provides a sencha tea juice, wherein the sencha tea juice is prepared by the preparation method as described in the first aspect.

[0060] In a third aspect, the present invention provides a use of the decocted tea juice as described in the second aspect in beverages, dairy products, and health products.

[0061] In a fourth aspect, the present invention provides a sencha milk tea, wherein the sencha milk tea comprises the following components in parts by weight:

[0062]

[0063]

[0064] The second aspect provides 10-50 portions of the sencha tea juice, for example, 15 portions, 20 portions, 25 portions, 30 portions or 40 portions.

[0065] The protein is 0-6 parts, for example, 0 parts, 2 parts, 4 parts or 5 parts.

[0066] The oil is 0-5 parts, for example, 0 parts, 2 parts or 4 parts.

[0067] The sugar is 0-10 parts, for example, 0 parts, 2 parts, 4 parts, 6 parts or 8 parts.

[0068] The emulsifier is 0-3 parts, for example, 0 parts, 1 part or 2 parts.

[0069] The buffer salt is 0.02-2 parts, for example, 0.1 parts, 0.5 parts, 1 part or 1.5 parts.

[0070] The stabilizer is 0-0.2 parts, for example, 0 parts, 0.1 parts or 0.15 parts.

[0071] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0072] Preferably, the protein comprises milk powder and / or milk.

[0073] Preferably, the oil comprises any one of coconut oil, palm oil or non-dairy creamer, or a combination of at least two of them.

[0074] Preferably, the sugar includes any one of white sugar, brown sugar or icing sugar, or a combination of at least two of them.

[0075] Preferably, the emulsifier includes any one of monoglyceride, sodium stearoyl lactylate or sucrose ester, or a combination of at least two thereof.

[0076] Preferably, the buffer salt includes any one of sodium carbonate, sodium bicarbonate, sodium tripolyphosphate, disodium hydrogen phosphate, sodium citrate, sodium hexametaphosphate or dipotassium hydrogen phosphate, or a combination of at least two thereof.

[0077] Preferably, the stabilizer comprises any one of carrageenan, microcrystalline cellulose, sodium carboxymethyl cellulose or guar gum, or a combination of at least two thereof.

[0078] Preferably, the sencha milk tea is prepared by the following method, which comprises: mixing the sencha tea juice provided by the second aspect with protein, oil, sugar, emulsifier, buffer salt and stabilizer to obtain the sencha milk tea.

[0079] Compared with the prior art, the present invention has the following beneficial effects:

[0080] The tea juice provided by the present invention is rinsed and extracted in an oxygen-free environment, thereby preventing the tea aroma from changing and the nutritional components such as tea polyphenols from being oxidized and discolored. At the same time, the extractants for the two extractions are both antioxidant aqueous solutions, thereby further preventing the effective components in the tea from being oxidized and keeping the tea juice bright in color.

[0081] The sencha tea juice obtained by the preparation method provided by the present invention has a strong aroma, a mellow and rich taste, is free of heavy bitterness and earthy taste, and has a mellow and clean taste, and can achieve the best tea juice flavor; the sencha milk tea beverage made with the sencha tea juice provided by the present invention as the main raw material has a long shelf life under room temperature conditions, and can ensure that the tea aroma is stable and does not fission, providing consumers with excellent quality. DETAILED DESCRIPTION

[0082] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0083] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0084] "Optional" or "any one" means that the subsequently described matter or event can or cannot occur, and that the description includes instances where the event occurs and instances where it does not.

[0085] The indefinite articles "a" and "an" before the elements or components of the present invention have no limitation on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the quantity obviously refers to the singular form only.

[0086] The terms "one embodiment", "some embodiments", "exemplarily", "specific examples" or "some examples" described in the present invention mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this document, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0087] Example 1

[0088] This embodiment provides a decocted tea juice, and the preparation process of the decocted tea juice is as follows:

[0089] (1) Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment, and then the tea leaves were placed in an oxygen-free environment, and the tea leaves were sprayed and rinsed with 1.5 times the amount of vitamin C aqueous solution (400 ppm, 30° C., RO water) to obtain sencha tea leaves;

[0090] (2) placing the decocted tea leaves obtained in step (1) in a sealed anaerobic extraction container, setting the pressure of the anaerobic environment to 6 bar, adding 20 times the amount of vitamin C aqueous solution (400 ppm, 60° C., RO water) to soak the decocted tea leaves, performing an extraction, and obtaining tea juice A after 15 minutes;

[0091] (3) The tea leaves obtained in step (2) were subjected to secondary extraction in an anaerobic environment, and 3 times the amount of vitamin C aqueous solution (400 ppm, 90° C., RO water) was sprayed on the tea leaves and extracted at the same time, and tea juice B was collected after 5 minutes;

[0092] (4) Combine tea juice A and tea juice B, cool rapidly, centrifuge at 6000 rpm, collect the liquid and filter through 0.5 μm to obtain the sencha tea juice, which is then stored at 5° C. for later use.

[0093] Example 2

[0094] This embodiment provides a decocted tea juice, and the preparation process of the decocted tea juice is as follows:

[0095] (1) Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment, and then the tea leaves were placed in an oxygen-free environment, and the tea leaves were sprayed and rinsed with a 2-fold amount of vitamin C aqueous solution (50 ppm, 30° C., RO water) to obtain sencha tea leaves;

[0096] (2) placing the decocted tea leaves obtained in step (1) in a sealed anaerobic extraction container, setting the pressure of the anaerobic environment to 3 bar, adding 25 times the amount of vitamin C aqueous solution (50 ppm, 70° C., RO water) to infiltrate the decocted tea leaves, performing an extraction, and obtaining tea juice A after 18 minutes;

[0097] (3) The tea leaves obtained in step (2) were subjected to secondary extraction in an anaerobic environment, and 5 times the amount of vitamin C aqueous solution (50 ppm, 80° C., RO water) was sprayed on the tea leaves and extracted at the same time, and tea juice B was collected after 4 minutes;

[0098] (4) Combine tea juice A and tea juice B, cool rapidly, centrifuge at 7000 rpm, collect the liquid and filter through 0.5 μm to obtain the sencha tea juice, which is then stored at 5° C. for later use.

[0099] Example 3

[0100] This embodiment provides a decocted tea juice, and the preparation process of the decocted tea juice is as follows:

[0101] (1) Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment, and then the tea leaves were placed in an oxygen-free environment, and the tea leaves were sprayed and rinsed with a 1-fold amount of vitamin C aqueous solution (300 ppm, 40° C., RO water) to obtain sencha tea leaves;

[0102] (2) placing the decocted tea leaves obtained in step (1) in a sealed anaerobic extraction container, setting the pressure of the anaerobic environment to 8 bar, adding 20 times the amount of vitamin C aqueous solution (300 ppm, 60° C., RO water) to soak the decocted tea leaves, performing an extraction, and obtaining tea juice A after 13 minutes;

[0103] (3) The tea leaves obtained in step (2) were subjected to secondary extraction in an anaerobic environment, and a 2-fold amount of vitamin C aqueous solution (350 ppm, 90° C., RO water) was used to spray the tea leaves and extract them at the same time, and tea juice B was collected after 5 minutes;

[0104] (4) Combine tea juice A and tea juice B, cool rapidly, centrifuge at 5000 rpm, collect the liquid and filter through 0.5 μm to obtain the sencha tea juice, which is then stored at 5° C. for later use.

[0105] Example 4

[0106] This embodiment provides a decocted tea juice, and the preparation process of the decocted tea juice is as follows:

[0107] The difference between this embodiment and embodiment 1 is only that step (1) is different. Step (1) of this embodiment is:

[0108] Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment to obtain decocted tea leaves. Other raw materials, dosages and preparation methods were the same as those in Example 1.

[0109] Example 5

[0110] This embodiment provides a decocted tea juice, and the preparation process of the decocted tea juice is as follows:

[0111] The only difference between the above method and Example 1 is that the concentration of the vitamin C aqueous solution is replaced with 600 ppm. Other raw materials, dosages and preparation methods are the same as those in Example 1.

[0112] Comparative Example 1

[0113] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0114] (1) spraying and rinsing green tea leaves with 1.5 times the amount of RO water to obtain sencha tea leaves;

[0115] (2) Using a Kneada extraction device, the sencha tea leaves were extracted with 40 times RO water at 80°C, and sencha tea juice was obtained after 20 minutes;

[0116] (3) Rapidly adding vitamin C (0.008-0.015%) and sodium isoascorbate (0.02-0.04%) to the sencha juice, adjusting the pH value to 4.6-5.2, filtering through 100 mesh, cooling to 15° C., and centrifuging at 6000 rpm to obtain the sencha juice.

[0117] Comparative Example 2

[0118] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0119] The difference between this comparative example and comparative example 1 is only that step (1) is different. Step (1) of this comparative example is:

[0120] Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment, and then the tea leaves were sprayed and rinsed with 1.5 times the amount of RO water to obtain decocted tea leaves. Other raw materials, dosages and preparation methods were the same as those in Comparative Example 1.

[0121] Comparative Example 3

[0122] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0123] The difference between this comparative example and Example 1 is only that step (1) is different. Step (1) of this comparative example is:

[0124] The tea leaves were placed in an oxygen-free environment, and the tea leaves were sprayed and rinsed with a 2-fold amount of a vitamin C aqueous solution (50 ppm, 30° C., RO water) to obtain decocted tea leaves. Other raw materials, dosages and preparation methods were the same as those in Example 1.

[0125] Comparative Example 4

[0126] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0127] The only difference between it and Example 1 is that the vitamin C aqueous solution is replaced by RO water of equal mass, and other raw materials, amounts and preparation methods are the same as those in Example 1.

[0128] Comparative Example 5

[0129] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0130] (1) Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment, and then the tea leaves were placed in an oxygen-free environment, and the tea leaves were sprayed and rinsed with 1.5 times the amount of vitamin C aqueous solution (400 ppm, 30° C., RO water) to obtain sencha tea leaves;

[0131] (2) placing the decocted tea leaves obtained in step (1) in a sealed anaerobic extraction container, setting the pressure of the anaerobic environment to 6 bar, adding 20 times the amount of vitamin C aqueous solution (400 ppm, 60° C., RO water) to soak the decocted tea leaves, performing an extraction, and obtaining tea juice A after 15 minutes;

[0132] (3) The tea juice A is rapidly cooled, centrifuged at 6000 rpm, and the liquid is collected and filtered through 0.8 μm to obtain the sencha tea juice, which is then stored at 5° C. for later use.

[0133] Comparative Example 6

[0134] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0135] (1) Referring to CN103652008A, green tea leaves were subjected to microwave and infrared treatment, and then the tea leaves were placed in an oxygen-free environment, and the tea leaves were sprayed and rinsed with 1.5 times the amount of vitamin C aqueous solution (400 ppm, 30° C., RO water) to obtain sencha tea leaves;

[0136] (2) placing the decocted tea leaves obtained in step (1) in a sealed anaerobic extraction container, extracting the decocted tea leaves in an anaerobic environment, spraying the tea leaves with a 3-fold amount of vitamin C aqueous solution (400 ppm, 90° C., RO water), and extracting the tea leaves at the same time, collecting tea juice B after 5 minutes;

[0137] (3) The tea juice B is rapidly cooled and centrifuged at 6000 rpm. The liquid is collected and filtered through 0.5 μm to obtain the sencha tea juice, which is then stored at 5° C. for later use.

[0138] Comparative Example 7

[0139] This comparative example provides a kind of sencha tea juice, and the preparation process of the sencha tea juice is as follows:

[0140] The only difference between the above method and Example 1 is that step (1), step (2) and step (3) are all carried out in an aerobic environment. Other raw materials, dosages and preparation methods are the same as those in Example 1.

[0141] Test Example 1

[0142] The sencha tea juice prepared in Examples 1-5 and Comparative Examples 1-7 was tested for its Lab value by a colorimeter, and the HunterLab colorimeter UltraScan PRO was used to obtain accurate L, a, and b values ​​under D65 lighting conditions. The Lab color model is composed of three elements of illuminance (L) and a and b related to color. L represents luminosity, which is equivalent to brightness, a represents the range from magenta to green, and b represents the range from yellow to blue. The value range of L is from 0 to 100. The L value represents the brightness of the tea soup. The higher the value, the brighter the tea soup; the a value represents red-green color, +a represents reddish color, the larger the value, the darker the red color, -a represents greenish color, the smaller the value, the darker the green color; the b value represents yellow-blue color, +b represents yellowish color, the larger the value, the darker the yellow color. The test results are shown in Table 1.

[0143] Table 1

[0144]

[0145] According to the data in the table, the sencha tea juice prepared by the sencha tea juice preparation process provided by the present invention can have a stable and bright green-yellow color with excellent color. If the tea leaves are not rinsed with an aqueous solution containing an antioxidant before extraction, the brightness of the obtained tea juice will be reduced; if the traditional extraction method is used for aerobic extraction, even if an antioxidant is added, the brightness of the obtained tea juice will still be reduced, and the tea juice will be yellowish and dark, the green color will be greatly reduced, and the tea juice will turn brown faster; when the extraction is not performed in an anaerobic environment, even if the extractant contains an antioxidant, the color of the tea juice will be yellowish and dark.

[0146] Test Example 2

[0147] The flavor of the sencha tea juices prepared in Examples 1-5 and Comparative Examples 1-7 were evaluated and the yield was calculated with reference to the tea sensory evaluation criteria.

[0148] Yield = (content of tea polyphenols in tea juice × total amount of tea juice) / total amount of tea polyphenols in tea leaves. The results are shown in Table 2.

[0149] Table 2

[0150]

[0151] According to the data in the table, the decocted tea juice prepared by the decocted tea juice preparation process provided by the present invention has a mellow tea taste, a natural tea aroma, is clean and has no peculiar smell, and has a high yield. If the tea leaves are not rinsed with an aqueous solution containing an antioxidant before extraction, the resulting tea juice will have a bitter taste and an earthy taste; if the traditional extraction method is used for aerobic extraction, even if an antioxidant is added, the resulting tea juice will have a bitter taste and an unnatural tea aroma; if secondary extraction is not performed, the yield of tea polyphenols in the tea leaves will be greatly reduced, resulting in an increase in the amount of raw tea leaves, which increases the product cost.

[0152] Application Examples 1-5

[0153] This application example provides a sencha milk tea, and the raw materials include, by weight:

[0154]

[0155] Preparation method:

[0156] (1) The sencha tea juices prepared in Examples 1 to 5 were mixed with sodium tripolyphosphate respectively, and the pH value was adjusted to 7.0 to obtain a mixed solution A;

[0157] (2) Under a pressure of 250 / 50 bar, sodium stearoyl lactylate was added to 40 parts of RO water (75° C.) and dissolved for 10 min. Milk powder and coconut oil were added and stirred for 30 min until the components were dissolved to obtain a mixed solution B.

[0158] (3) Under the condition of internal pressure of 250 / 50 bar, the mixed solution A, the mixed solution B, the white sugar and the sodium carboxymethyl cellulose are fully mixed at 70° C., sterilized by UHT (137-142° C., 10-45 s), cooled to room temperature and aseptically filled to obtain the sencha milk tea.

[0159] Comparative Application Examples 1-7

[0160] This comparative application example provides a sencha milk tea, and the raw materials include, by weight:

[0161] The only difference between it and Application Example 1-5 is that the sencha tea juice prepared in Example 1-5 is replaced by the sencha tea juice prepared in Comparative Example 1-7 of equal mass.

[0162] Other raw materials, dosages and preparation methods are the same as those in Application Example 1-5.

[0163] Test Example 3

[0164] With reference to the product sensory evaluation standard, the flavor of the sencha milk tea provided in Example 1-5 and Comparative Application Example 1-7 was evaluated within 270 days. The evaluation results are shown in Table 3, where the evaluation adopts a seven-point system: 1 point - very poor; 2 points - relatively poor; 3 points - poor; 4 points - average; 5 points - good; 6 points - relatively good; 7 points - very good; * - has an unpleasant flavor; ☆ - has a relatively serious unpleasant flavor; ★ - has a very serious unpleasant flavor.

[0165] Table 3

[0166] 15 days 30 days 60 days 90 days 120 days 150 days 180 days 270 days Application Example 1 7.0 7.0 7.0 7.0 6.5 6.5 6.0 5.0＊ Application Example 2 7.0 7.0 7.0 6.5 6.5 6.0 5.5＊ 5.0＊ Application Example 3 7.0 7.0 7.0 7.0 6.5 6.5 6.0＊ 5.0＊ Application Example 4 6.5 6.5 6.5 6.5 6.0 6.0 5.0☆ 3.0★ Application Example 5 6.5 6.5 6.5 6.0 6.0 5.5＊ 5.5☆ 5.0★ Comparative Example 1 6.5 6.0 4.5＊ 4.5＊ 3.5☆ 3.5★ 3.0★ 2.5★ Comparative Example 2 6.5 6.5 6.5 5.5 4.5 4.0＊ 3.5☆ 3.0★ Comparative Example 3 7.0 6.5 6.0 5.5＊ 4.5＊ 3.5☆ 3.0★ 2.5★ Comparative Example 4 7.0 6.5 6.0 5.5 4.5＊ 4.0☆ 3.5☆ 3.0★ Comparative Example 5 7.0 7.0 7.0 7.0 6.5 6.5 6.0 5.0＊ Comparative Example 6 7.0 7.0 7.0 7.0 6.5 6.5 6.0 5.0＊ Comparative Example 7 6.0 6.0 6.0 5.5 5.5 5.0＊ 4.5☆ 2.5★

[0167] According to the data in the table, the sencha milk tea prepared by using the sencha tea juice prepared by the embodiment of the present invention has better flavor and flavor effect after long-term storage than the comparative example, effectively overcoming the defects of tea aroma oxidation fission that occurs when the tea juice is easily extracted at high temperature and high pressure, and the increase of the bitterness of the tea leaves, the generation of unpleasant and miscellaneous flavors, which leads to the cracking and instability of the quality of the produced milk tea. When the traditional extraction process is used and infrared flavoring is not performed, the milk tea will have an unpleasant flavor in 60 days, and the storage time will be greatly shortened; if the amount of antioxidants is increased, the amount of acidity regulators used to adjust the pH value will increase, which will seriously affect the taste and flavor of the product.

[0168] Test Example 4

[0169] The appearance and color of the sencha milk tea provided in the corresponding use cases 1-5 and comparative application examples 1-7 were observed within 270 days. The results are shown in Table 4, where the evaluation indicators are shown in the following table:

[0170]

[0171] Table 4

[0172] 15 days 30 days 60 days 90 days 120 days 150 days 180 days 270 days Application Example 1 very good very good very good very good good good generally generally Application Example 2 very good very good very good good good generally generally generally Application Example 3 very good very good very good very good good good generally generally Application Example 4 very good very good very good very good good good generally generally Application Example 5 good good good generally generally Difference Very bad Very bad Comparative Example 1 good good good generally generally generally Very bad Very bad Comparative Example 2 very good very good good good good generally Difference Slightly worse Comparative Example 3 very good very good very good good good generally Slightly worse Very bad Comparative Example 4 very good good good good good generally Very bad Very bad Comparative Example 5 very good very good very good very good good good generally generally Comparative Example 6 very good very good very good very good good good generally generally Comparative Example 7 good good good generally Difference Difference Very bad Very bad

[0173] According to the data in the table, the milk tea beverage prepared with the sencha tea juice prepared by the sencha tea juice preparation method provided by the present invention as the main raw material can be sold at room temperature, because the color and flavor of the sencha milk tea are stable after 6 months, and the color and flavor of the product can also provide consumers with better quality after 9 months, which has broad market benefits. When the traditional extraction process is used and infrared flavoring is not performed, the milk tea will appear slightly brown in 90 days, and the color stability will be greatly reduced; if the amount of antioxidants is increased, the amount of acidity regulator for adjusting the pH value will increase, which will increase the speed of product discoloration.

[0174] The applicant declares that the present invention illustrates the preparation process of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing tea juice, characterized in that: The preparation method comprises: (1) extracting aroma and washing green tea leaves in sequence to obtain sencha tea leaves; The aroma enhancement is to subject the tea leaves to microwave and infrared treatment, the rinsing agent is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the rinsing agent is 10-60° C., the mass ratio of the rinsing agent to the tea leaves is (1-2):1, and the rinsing is performed in an anaerobic environment; (2) extracting the sencha tea leaves once; The primary extraction is carried out in an oxygen-free environment, the pressure of the primary extraction is 1-9 bar, the primary extraction is carried out in an infiltration manner, the time is 15-20 min, the extractant is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the extractant is 60-75° C., and the mass ratio of the extractant to the sencha tea leaves is (10-30):1; (3) subjecting the decocted tea leaves obtained in step (2) to secondary extraction; The secondary extraction is carried out in an oxygen-free environment, the secondary extraction is carried out by spraying and extracting, the time is 5-6 min, the extractant is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the extractant is 75-90° C., and the mass ratio of the extractant to the sencha tea leaves is (1-10):1; (4) The extracts obtained from the primary extraction and the secondary extraction are combined, and then solid-liquid separation is performed to obtain the sencha tea juice.

2. The preparation method according to claim 1, characterized in that: The solid-liquid separation includes primary separation and secondary separation.

3. The preparation method according to claim 2, characterized in that: The primary separation is performed by centrifugation.

4. The preparation method according to claim 3, characterized in that: The centrifugal speed is 5000-8000 rpm.

5. The preparation method according to claim 2, characterized in that: The secondary separation is performed by filtering.

6. The preparation method according to claim 5, characterized in that: The pore size of the filter paper used for filtration is 0.5-1 μm.

7. The preparation method according to claim 1, characterized in that: The sencha tea juice is stored at 4-15°C.

8. The preparation method according to claim 1, characterized in that: The preparation process comprises the following steps: (1) extracting aroma and washing green tea leaves in sequence to obtain sencha tea leaves; The aroma enhancement is to subject the tea leaves to microwave and infrared treatment, the rinsing agent is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the rinsing agent is 10-60° C., the mass ratio of the rinsing agent to the tea leaves is (1-2):1, and the rinsing is performed in an anaerobic environment; (2) extracting the sencha tea leaves once; The primary extraction is carried out in an oxygen-free environment, the pressure of the primary extraction is 1-9 bar, the primary extraction is carried out in an infiltration manner, the time is 15-20 min, the extractant is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the extractant is 60-75° C., and the mass ratio of the extractant to the sencha tea leaves is (10-30):1; (3) subjecting the decocted tea leaves obtained in step (2) to secondary extraction; The secondary extraction is carried out in an oxygen-free environment, the secondary extraction is carried out by spraying and extracting, the time is 5-6 min, the extractant is a vitamin C aqueous solution, the mass concentration of vitamin C in the vitamin C aqueous solution is 50-400 ppm, the temperature of the extractant is 75-90° C., and the mass ratio of the extractant to the sencha tea leaves is (1-10):1; (4) combining the extracts obtained from the primary extraction and the secondary extraction, and then performing solid-liquid separation to obtain the decocted tea juice; The solid-liquid separation includes primary separation and secondary separation. The primary separation is performed by centrifugation at a rotation speed of 5000-8000 rpm, and the secondary separation is performed by filtration at a pore size of 0.5-1 μm.

9. A tea juice for making tea, characterized in that: The sencha tea juice is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the sencha tea juice according to claim 9 in beverages, dairy products and health products.

11. A sencha milk tea, characterized in that: The sencha milk tea comprises the following components by weight: 10-50 portions of the sencha tea juice according to claim 9 Protein 0-6 servings 0-5 parts of oil Sugar 0-10 parts Emulsifier 0-3 parts Buffer salt 0.02-2 parts Stabilizer 0-0.2 parts.

12. The sencha milk tea according to claim 11, characterized in that: The protein comprises milk powder and / or milk.

13. The sencha milk tea according to claim 11, characterized in that: The oil comprises any one of coconut oil, palm oil or non-dairy creamer or a combination of at least two of them.

14. The sencha milk tea according to claim 11, characterized in that: The sugar includes any one of white sugar, brown sugar or icing sugar, or a combination of at least two of them.

15. The sencha milk tea according to claim 11, characterized in that: The emulsifier includes any one of monoglyceride, sodium stearoyl lactylate or sucrose ester or a combination of at least two thereof.

16. The sencha milk tea according to claim 11, characterized in that: The buffer salt includes any one of sodium carbonate, sodium bicarbonate, sodium tripolyphosphate, disodium hydrogen phosphate, sodium citrate, sodium hexametaphosphate or dipotassium hydrogen phosphate, or a combination of at least two thereof.

17. The sencha milk tea according to claim 11, characterized in that: The stabilizer includes any one of carrageenan, microcrystalline cellulose, sodium carboxymethyl cellulose or guar gum, or a combination of at least two of them.

18. The sencha milk tea according to any one of claims 11 to 17, characterized in that: The sencha milk tea is prepared by the following method, which comprises: mixing the sencha tea juice according to claim 9 with protein, oil, sugar, emulsifier, buffer salt and stabilizer to obtain the sencha milk tea.

Images