Black tea extract with strong antioxidant activity and extraction process

Abstract

The invention provides a black tea extract with strong antioxidant activity and an extraction process. The extraction process of the black tea extract comprises the following steps: A, selecting fresh black tea and cleaning; b, airing the cleaned black tea at normal temperature; c, carrying out ultrafine crushing on the dried black tea; d, adding the ultrafine crushed black tea into an ethanol solution for extraction to obtain a mixed solution; e, adding purified water into the mixed solution, fully stirring, adding into a pot, boiling, slowly cooling to room temperature, and filtering to obtain filtrate; f, adding the filtrate into a centrifugal machine for centrifugal treatment to obtain centrifugate; g, performing supercritical carbon dioxide extraction on the centrifugate to obtain extract liquor; h, finally, the extract liquid is subjected to low-temperature drying, and the black tea extract is obtained.The extract obtained through the method is fragrant in fragrance, strong in taste and red and bright in soup color, loss of effective components is avoided, and the extracted black tea extract has high oxidation resistance and good taste.

Description

Technical Field

[0001] The present application relates to the technical field of black tea extract extraction, and in particular to a black tea extract with strong antioxidant activity and an extraction process. Background Art

[0002] Chinese tea culture has a long history. It is said that tea originated from Shennong, was known to Duke Zhou of Lu, flourished in the Tang Dynasty and prospered in the Song Dynasty. Dr. Joseph Needham, a world-renowned historian of science and technology, regarded Chinese tea as the fifth major contribution to mankind after China's four great inventions (gunpowder, papermaking, compass and printing). Tea was originally used as medicine, and later developed into a beverage. Chinese medicine believes that tea can clear the head, help digestion, and promote urination. It is a natural health drink and is becoming an indispensable and essential product in people's lives.

[0003] There are many ways to process tea, which have formed different styles such as green tea, yellow tea, oolong tea, black tea, dark tea, and white tea. Black tea is the tea with the largest production and sales volume in the world, and it is also the tea with the most producing countries. The earliest black tea in the world was invented by tea farmers in the Wuyishan tea area in Fujian, China. It is called "Zhengshan Xiaozhong". It is a fully fermented tea. It is made from the buds and leaves of tea trees and is refined through typical processes such as withering, rolling (cutting), fermentation, and drying. Because the color of its dry tea and the brewed tea soup are mainly red, it is called black tea. Black tea is warm in nature, removes cold, warms the stomach, and also has the effects of preventing caries, strengthening the stomach and intestines, aiding digestion, delaying aging, lowering blood sugar, blood pressure, blood lipids, anti-cancer, and anti-radiation. After fermentation, the catechins in black tea are transformed through oxidative dehydrogenation polymerization to form theaflavins and thearubigins. The chlorophyll decomposition products of pheophorbide and pheophytin and pectin, protein, sugar and phenolic substances are oxidized, and the bitter tea polyphenols are also oxidatively decomposed, giving black tea the characteristics of black tea, red soup, red leaves and sweet taste.

[0004] At present, the extraction process of black tea extract is relatively high in temperature and time, which causes the chlorophyll in the extract to oxidize and lose its green color, catechins to oxidize and transform into theaflavins, aromatic substances to oxidize and deteriorate, and the extraction rate of aromatic substances is relatively low, which affects the activity of black tea extract. Therefore, it is necessary to design an extraction process for black tea extract with strong antioxidant activity. Summary of the invention

[0005] The present application provides an extraction process for a black tea extract with strong antioxidant activity, so as to solve the problems of complex extraction process and loss of effective ingredients in the prior art, so as to achieve an extract with rich aroma, strong taste and bright red soup color, and avoid the loss of effective ingredients. The extracted black tea extract has strong antioxidant activity and good taste, and can be used in food and health products.

[0006] The present application provides a process for extracting a black tea extract having strong antioxidant activity, and the process for extracting the black tea extract comprises the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0007] Preferably, in step A, the fresh black tea is repeatedly rinsed with clean water for 3-5 times.

[0008] Preferably, in step C, black tea is added to a grinder for grinding, firstly by low-speed grinding, the grinding rate is 200-400 rpm, and the grinding time is 20min-40min; then by high-speed grinding, the grinding rate is 4000-6000 rpm, and the grinding time is 20min-30min.

[0009] Preferably, the concentration of ethanol in step D is 40%-50%, and the crushed black tea is soaked in ethanol for 1-2 days and then refluxed in a water bath.

[0010] Preferably, the weight ratio between the pure water added in step E and the mixed solution is 1:(2-3).

[0011] Preferably, in step F, the centrifugal rate is 8000-10000 rpm, and the centrifugal time is 12 min-20 min.

[0012] Preferably, in step G, the temperature for supercritical carbon dioxide extraction is 45°C-55°C, the pressure is 30MPa-40MPa, the carbon dioxide flow rate is 20L-25L / h, and the extraction time is 3h-4h.

[0013] Preferably, in step H, the drying temperature is 40° C.-50° C., and the drying time is 70 min-90 min.

[0014] Beneficial effects: (1) The extraction process adopted by the present invention is simple, and the obtained extract has a rich aroma, a strong taste, and a bright red soup color, which avoids the loss of effective ingredients. The extracted black tea extract has strong antioxidant properties and a good taste, and can be used in food and health products; (2) The present invention adopts ethanol for extraction, and performs water bath reflux after extraction, which can prevent the loss of effective ingredients in black tea; (3) The present invention adopts supercritical carbon dioxide for extraction, and the obtained extract has strong antioxidant properties, thereby ensuring that the black tea extract has strong antioxidant properties.

[0015] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0018] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0019] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application is clearly and completely described below.

[0020] Embodiment 1: The present application provides a process for extracting a black tea extract having strong antioxidant activity, and the process for extracting the black tea extract comprises the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0021] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 3 times.

[0022] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 200 rpm, and the grinding time is 20 min; then high-speed grinding is adopted, the grinding rate is 4000 rpm, and the grinding time is 20 min.

[0023] In this embodiment, the concentration of ethanol in step D is 40%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0024] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:2.

[0025] In this embodiment, the centrifugal speed in step F is 8000 rpm and the centrifugal time is 12 min.

[0026] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 45° C., the pressure is 30 MPa, the carbon dioxide flow rate is 20 L / h, and the extraction time is 3 h.

[0027] In this embodiment, the drying temperature in step H is 40° C. and the drying time is 70 min.

[0028] Example 2: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0029] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 5 times.

[0030] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 400 rpm, and the grinding time is 40 min; then high-speed grinding is adopted, the grinding rate is 6000 rpm, and the grinding time is 30 min.

[0031] In this embodiment, the concentration of ethanol in step D is 50%, and the crushed black tea is soaked in ethanol for 2 days and then refluxed in a water bath.

[0032] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:3.

[0033] In this embodiment, the centrifugal speed in step F is 10000 rpm and the centrifugal time is 20 min.

[0034] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 55° C., the pressure is 40 MPa, the carbon dioxide flow rate is 25 L / h, and the extraction time is 4 hours.

[0035] In this embodiment, the drying temperature in step H is 50° C. and the drying time is 90 min.

[0036] Example 3: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0037] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 3 times.

[0038] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 250 rpm, and the grinding time is 25 min; then high-speed grinding is adopted, the grinding rate is 4500 rpm, and the grinding time is 22 min.

[0039] In this embodiment, the concentration of ethanol in step D is 42%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0040] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:2.

[0041] In this embodiment, the centrifugal speed in step F is 8400 rpm and the centrifugal time is 14 min.

[0042] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 47° C., the pressure is 32 MPa, the carbon dioxide flow rate is 21 L / h, and the extraction time is 3 h.

[0043] In this embodiment, the drying temperature in step H is 42° C. and the drying time is 75 min.

[0044] Example 4: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0045] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 5 times.

[0046] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 380 rpm, and the grinding time is 38 min; then high-speed grinding is adopted, the grinding rate is 5500 rpm, and the grinding time is 28 min.

[0047] In this embodiment, the concentration of ethanol in step D is 48%, and the crushed black tea is soaked in ethanol for 2 days and then refluxed in a water bath.

[0048] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:3.

[0049] In this embodiment, the centrifugal speed in step F is 9500 rpm and the centrifugal time is 18 min.

[0050] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 52° C., the pressure is 38 MPa, the carbon dioxide flow rate is 24 L / h, and the extraction time is 4 h.

[0051] In this embodiment, the drying temperature in step H is 48° C. and the drying time is 86 min.

[0052] Example 5: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0053] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 3 times.

[0054] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 320 rpm, and the grinding time is 28 min; then high-speed grinding is adopted, the grinding rate is 4800 rpm, and the grinding time is 23 min.

[0055] In this embodiment, the concentration of ethanol in step D is 42%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0056] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:2.

[0057] In this embodiment, the centrifugal speed in step F is 8900 rpm and the centrifugal time is 16 min.

[0058] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 47° C., the pressure is 33 MPa, the carbon dioxide flow rate is 22 L / h, and the extraction time is 3 h.

[0059] In this embodiment, the drying temperature in step H is 43° C. and the drying time is 74 min.

[0060] Example 6: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0061] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 5 times.

[0062] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 380 rpm, and the grinding time is 36 min; then high-speed grinding is adopted, the grinding rate is 5400 rpm, and the grinding time is 26 min.

[0063] In this embodiment, the concentration of ethanol in step D is 46%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0064] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:3.

[0065] In this embodiment, the centrifugal speed in step F is 9200 rpm and the centrifugal time is 17 min.

[0066] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 48° C., the pressure is 37 MPa, the carbon dioxide flow rate is 24 L / h, and the extraction time is 4 h.

[0067] In this embodiment, the drying temperature in step H is 47° C. and the drying time is 85 min.

[0068] Example 7: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0069] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 3 times.

[0070] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 200 rpm, and the grinding time is 40 min; then high-speed grinding is adopted, the grinding rate is 4000 rpm, and the grinding time is 30 min.

[0071] In this embodiment, the concentration of ethanol in step D is 40%, and the crushed black tea is soaked in ethanol for 2 days and then refluxed in a water bath.

[0072] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:2.

[0073] In this embodiment, the centrifugal speed in step F is 8000 rpm and the centrifugal time is 20 min.

[0074] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 45° C., the pressure is 40 MPa, the carbon dioxide flow rate is 20 L / h, and the extraction time is 4 hours.

[0075] In this embodiment, the drying temperature in step H is 40° C. and the drying time is 90 min.

[0076] Example 8: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0077] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 4 times.

[0078] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 300 rpm, and the grinding time is 32 min; then high-speed grinding is adopted, the grinding rate is 4400 rpm, and the grinding time is 26 min.

[0079] In this embodiment, the concentration of ethanol in step D is 44%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0080] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:3.

[0081] In this embodiment, the centrifugal speed in step F is 8800 rpm and the centrifugal time is 15 min.

[0082] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 48° C., the pressure is 34 MPa, the carbon dioxide flow rate is 22 L / h, and the extraction time is 4 hours.

[0083] In this embodiment, the drying temperature in step H is 45° C. and the drying time is 90 min.

[0084] Example 9: A process for extracting a black tea extract having strong antioxidant activity, the process for extracting the black tea extract comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0085] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 4 times.

[0086] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 300 rpm, and the grinding time is 30 min; then high-speed grinding is adopted, the grinding rate is 5000 rpm, and the grinding time is 25 min.

[0087] In this embodiment, the concentration of ethanol in step D is 45%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0088] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:3.

[0089] In this embodiment, the centrifugal speed in step F is 9000 rpm and the centrifugal time is 16 min.

[0090] In this embodiment, the temperature for supercritical carbon dioxide extraction in step G is 50° C., the pressure is 35 MPa, the carbon dioxide flow rate is 23 L / h, and the extraction time is 4 h.

[0091] In this embodiment, the drying temperature in step H is 45° C. and the drying time is 80 min.

[0092] Control group: A process for extracting a black tea extract having strong antioxidant activity, the process comprising the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

[0093] In this embodiment, in step A, the fresh black tea is repeatedly rinsed with clean water for 3 times.

[0094] In this embodiment, in step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 200 rpm, and the grinding time is 20 min; then high-speed grinding is adopted, the grinding rate is 4000 rpm, and the grinding time is 20 min.

[0095] In this embodiment, the concentration of ethanol in step D is 40%, and the crushed black tea is soaked in ethanol for 1 day and then refluxed in a water bath.

[0096] In this embodiment, the weight ratio between the pure water added in step E and the mixed solution is 1:2.

[0097] In this embodiment, the centrifugal speed in step F is 8000 rpm and the centrifugal time is 12 min.

[0098] In this embodiment, the drying temperature in step H is 40° C. and the drying time is 70 min.

[0099] Experimental example: The black tea extract extracted by each embodiment of the present invention is tested for the content of tea polyphenols, an active ingredient, using a CSY-SC8 tea polyphenol tester according to the national standard GB21733-2008. A spectrophotometer is used to perform a DPPH test according to the Shanghai Daily Chemical Industry Association group standard T / SHRH006-2018. The free radical scavenging ability of the sample, i.e., the size of the antioxidant activity, is evaluated based on the results. The data are as follows: The invention adopts ethanol for extraction, and performs water bath reflux after extraction, which can prevent the effective components in the black tea from being lost; the invention adopts supercritical carbon dioxide for extraction, and the obtained extract has strong antioxidant properties, thereby ensuring that the black tea extract has strong antioxidant properties.

[0100] In summary, the extraction process adopted by the present invention is simple, the obtained extract has a rich aroma, a strong taste, and a bright red soup color, and the loss of effective ingredients is avoided. The extracted black tea extract has strong antioxidant properties and a good taste, and can be used in food and health products.

[0101] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A process for extracting a black tea extract having strong antioxidant activity, characterized in that: The black tea extract extraction process includes the following steps: A. Select fresh black tea and wash it; B. Dry the washed black tea at room temperature; C. Ultra-finely grind the dried black tea; D. adding the ultrafinely crushed black tea into an ethanol solution for extraction to obtain a mixed solution; E. Add purified water to the mixed solution, stir thoroughly, add to a pot and boil, then slowly cool to room temperature and filter to obtain a filtrate; F. Add the filtrate into a centrifuge and centrifuge to obtain a centrifuge; G. extracting the centrifuge liquid with supercritical carbon dioxide to obtain an extract; H. Finally, the extract is dried at low temperature to obtain black tea extract.

2. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: In step A, the fresh black tea is repeatedly rinsed with clean water for 3-5 times.

3. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: In step C, black tea is added into a grinder for grinding, firstly, low-speed grinding is adopted, the grinding rate is 200-400 rpm, and the grinding time is 20min-40min; then high-speed grinding is adopted, the grinding rate is 4000-6000 rpm, and the grinding time is 20min-30min.

4. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: In step D, the concentration of ethanol is 40%-50%. The crushed black tea is soaked in ethanol for 1-2 days and then refluxed in a water bath.

5. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: The weight ratio between the pure water added in step E and the mixed solution is 1:(2-3).

6. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: In step F, the centrifugal speed is 8000-10000 rpm, and the centrifugal time is 12 min-20 min.

7. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: In step G, the temperature for supercritical carbon dioxide extraction is 45° C.-55° C., the pressure is 30 MPa-40 MPa, the carbon dioxide flow rate is 20 L-25 L / h, and the extraction time is 3 h-4 h.

8. The extraction process of a black tea extract with strong antioxidant activity according to claim 1, characterized in that: In the step H, the drying temperature is 40° C.-50° C., and the drying time is 70 min-90 min.

9. A black tea extract with strong antioxidant activity, characterized in that: The black tea extract is obtained by extraction according to any one of claims 1 to 8.

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