Method for extracting and purifying high-content tea pigment

Abstract

The invention relates to the technical field of extraction of effective active ingredients of plants, and provides a method for extracting and purifying high-content tea pigment, which comprises the following steps: weighing a tea leaf raw material, extracting by adopting a hot reflux extraction mode, adding an ethanol water solution with the volume fraction of 0-50%, and extracting at the temperature of 60-100 DEG C; filtering the extracting solution, adjusting the pH value of the extracting solution to 9-11, concentrating under reduced pressure, adding ethanol into the concentrated solution until the alcohol content is 40% v / v-70% v / v, carrying out alcohol precipitation, dissolving and crystallizing the precipitate after the alcohol precipitation, and collecting the supernate; and adsorbing and eluting the obtained supernatant by using a resin filler, collecting the eluent, concentrating and drying to obtain a tea pigment product with the tea pigment content of more than or equal to 80%. The prepared tea is high in pigment content and yield, good in quality, simple in step and suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of plant active ingredient separation, and particularly relates to a method for extracting and purifying tea pigment with high content. Background Art

[0002] Tea pigment is a mixture of water-soluble pigments formed by the continuous oxidation and polymerization of polyphenolic compounds represented by catechins in tea leaves. The main components of tea pigment are theaflavins (TFs), thearubigins (TRs), and theabrownins (TBs). Tea pigment can be used in the fields of food and medicine. Tea pigment capsules have the effects of clearing the head and eyes, resolving phlegm and reducing fat, and are used for symptoms such as dizziness of the head and eyes, chest tightness and chest pain caused by the intermingling of phlegm and stasis, hyperlipidemia, coronary heart disease, angina pectoris, and cerebral infarction.

[0003] Patent publication number CN1074618A discloses a tea pigment and its production method, which uses tea leaves as raw materials and is prepared by decoction extraction, alkalization concentration, ethanol acidification reflux, and alkalization precipitation methods. The tea pigment prepared by this method is obtained from tea leaves, is natural and healthy, has high safety in use, good quality of tea pigment, and high market acceptance. However, in industrial applications, it is found that the technical solution of patent publication number CN1074618A still has the following defects: the tea residue discarded during extraction contains more incompletely oxidized tea polyphenols and unextracted tea pigment, resulting in waste of raw materials and low extraction rate. At the same time, the prepared tea pigment has a high salt content and strong corrosiveness to production equipment, especially high-temperature drying equipment. In view of this, the present application aims to improve the extraction rate of tea pigment, reduce the salt content, and obtain high-quality tea pigment by improving on the traditional method. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a method for extracting and purifying tea pigment with high content, which can improve the extraction rate of tea pigment and reduce the formation of tea pigment salt while ensuring the quality of tea pigment.

[0005] To achieve the above object, the present invention provides a method for extracting and purifying tea pigment with high content. Weigh the tea raw materials and extract them by thermal reflux extraction method. Add an ethanol aqueous solution with a volume fraction of 0 - 50%, the extraction temperature is 60 - 100 °C, and the extraction time is 2 - 4 h. After the extract is filtered, adjust the pH of the extract to 9 - 11 with an inorganic base solution and concentrate it under reduced pressure. Add ethanol to the concentrated solution until the alcohol content is 40% v / v - 70% v / v for alcohol precipitation, and control the alcohol precipitation temperature at 4 - 20 °C. The precipitate after alcohol precipitation is dissolved by adding distilled water, and then crystallized in a crystallization tank, and the supernatant is collected. The obtained supernatant is adsorbed and eluted with a resin filler, static adsorption is carried out for 4 - 10 h, first eluted with pure water, and then eluted with an ethanol with a volume fraction of 50 - 95%. The eluate is collected and concentrated and dried to obtain a tea pigment product with a tea pigment content ≥ 80%.

[0006] Further preferably, the selected tea raw material is any one of green tea, black tea, oolong tea, and pu-erh tea.

[0007] Further preferably, the alcohol precipitation time is 10 - 20 h.

[0008] Further preferably, when dissolving, add distilled water 2 - 5 times the amount of the precipitate for dissolution.

[0009] Further preferably, the crystallization temperature is 4 - 10 °C.

[0010] Further preferably, the resin filler is selected from any one of D101, AB - 8, HPD - 100, X - 5, ADS - 8, and HPD - 450.

[0011] Further preferably, the mass ratio of the supernatant to the resin is 1:0.5 - 1.5 (kg / kg).

[0012] Further preferably, the inorganic base solution is a sodium hydroxide solution with a mass fraction of 15 - 25%.

[0013] Due to the adoption of the above - mentioned technical solution, the present invention has the following advantages: First of all, compared with the traditional acid - base oxidation method, the present invention cuts off the use of acid aqueous solution, no salt solution is generated in the whole process, which will reduce the discharge of waste and waste liquid. In addition, since no tea pigment salt will be formed, it helps to improve the content of tea pigment in the subsequent process, and the whole production process is simple and efficient.

[0014] Secondly, after the supernatant after alcohol precipitation undergoes the crystallization step, it helps to remove the remaining impurities such as alkaline polysaccharides, thus reducing the pressure on the subsequent resin filler. By using the resin filler, the content of tea pigment is greatly improved. More importantly, the use of the resin filler does not require a chromatography column for dynamic adsorption and desorption, and the static method can be used, which greatly reduces the production cost.

[0015] The present invention improves the total content and yield of tea pigments through a multi-stage purification process. Detailed implementation manners

[0016] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] The present invention provides a method for extracting and purifying tea pigments with high content. Weigh the tea raw materials, and the selected tea raw materials are any one of green tea, black tea, oolong tea, and pu-erh tea. Use the hot reflux extraction method for extraction, add an ethanol aqueous solution with a volume fraction of 0 - 50%, the extraction temperature is 60 - 100°C, and the extraction time is 2 - 4h; after the extract is filtered, adjust the pH of the extract to 9 - 11 with a sodium hydroxide solution with a mass fraction of 15 - 25%, and concentrate under reduced pressure. Add ethanol to the concentrated solution to make the alcohol content 40% v / v - 70% v / v for alcohol precipitation, control the alcohol precipitation temperature at 4 - 20°C, and the alcohol precipitation time is 10 - 20h; for the precipitate after alcohol precipitation, add distilled water 2 - 5 times the amount of the precipitate for dissolution, and then crystallize in a crystallization tank, the crystallization temperature is 4 - 10°C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler is any one of D101, AB-8, HPD-100, X-5, ADS-8, and HPD-450. The amount of the supernatant and the amount of the resin are 1:0.5 - 1.5 (kg / kg). Use static adsorption for 4 - 10h. First, elute with pure water. After the color becomes lighter, elute with an ethanol with a volume fraction of 50 - 95%. Collect the eluate and concentrate and dry it to obtain a tea pigment product with a tea pigment content ≥ 80%.

[0018] In the present invention, a sodium hydroxide solution is used to adjust the pH. Those skilled in the art can understand that using other inorganic base solutions can also achieve the same effect. Example 1

[0019] Weigh 60 kg of green tea samples and extract them by the hot reflux extraction method. Add 300 L of an ethanol aqueous solution with a volume fraction of 10%, with an extraction temperature of 60 °C and an extraction time of 2 h. After the extract is filtered, adjust the pH of the extract to 9 with a sodium hydroxide solution with a mass fraction of 20%, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution to make the alcohol content 40% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 4 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water twice the amount of the precipitate for dissolution, and then crystallize in a crystallization tank at a crystallization temperature of 4 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is D101, and the ratio of the amount of the supernatant to the amount of the resin is 1:0.5 (kg / kg). Static adsorption is carried out for 6 h, and intermittent stirring is carried out at 120 rpm during static adsorption. Samples are taken every 2 h to detect the adsorption rate. First, elute with pure water, and after the color fades, elute with an ethanol solution with a volume fraction of 60%. Collect the eluate for concentration and drying to obtain 9.06 kg of a tea pigment product with a tea pigment content of 87.58%. Example 2

[0020] Weigh 60 kg of black tea samples and extract them by the hot reflux extraction method. Add 360 L of an ethanol aqueous solution with a volume fraction of 20%, with an extraction temperature of 70 °C and an extraction time of 3 h. After the extract is filtered, adjust the pH of the extract to 10 with a sodium hydroxide solution with a mass fraction of 20%, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution to make the alcohol content 50% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 8 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water three times the amount of the precipitate for dissolution, and then crystallize in a crystallization tank at a crystallization temperature of 6 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is AB-8, and the ratio of the amount of the supernatant to the amount of the resin is 1:1 (kg / kg). Static adsorption is carried out for 6 h, and intermittent stirring is carried out at 120 rpm during static adsorption. Samples are taken every 2 h to detect the adsorption rate. First, elute with pure water, and after the color fades, elute with an ethanol solution with a volume fraction of 50%. Collect the eluate for concentration and drying to obtain 7.81 kg of a tea pigment product with a tea pigment content of 85.46%. Example 3

[0021] Weigh 60 kg of oolong tea samples and extract them by the hot reflux extraction method. Add 600 L of an ethanol aqueous solution with a volume fraction of 30% and extract at a temperature of 80 °C for 4 h. After filtering the extract, adjust the pH of the extract to 11 with a sodium hydroxide solution with a mass fraction of 20% and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution to make the alcohol content 60% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 10 °C and the alcohol precipitation time at 12 h. Dissolve the precipitate after alcohol precipitation in 4 times the amount of distilled water by volume, then crystallize in a crystallization tank at a crystallization temperature of 8 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is HPD-100. The ratio of the amount of the supernatant to the amount of the resin is 1:1.5 (kg / kg). Static adsorption is carried out for 6 h. During static adsorption, intermittent stirring is carried out at 120 rpm, and the adsorption rate is detected by sampling every 2 h. First, elute with pure water. After the color fades, elute with an ethanol solution with a volume fraction of 60%. Collect the eluate and concentrate and dry it to obtain 8.42 kg of a tea pigment product with a tea pigment content of 83.57%. Example 4

[0022] Weigh 60 kg of pu-erh tea samples and extract them by the hot reflux extraction method. Add 900 L of an ethanol aqueous solution with a volume fraction of 40% and extract at a temperature of 90 °C for 3 h. After filtering the extract, adjust the pH of the extract to 10 with a sodium hydroxide solution with a mass fraction of 20% and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution to make the alcohol content 60% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 20 °C and the alcohol precipitation time at 12 h. Dissolve the precipitate after alcohol precipitation in 3 times the amount of distilled water by volume, then crystallize in a crystallization tank at a crystallization temperature of 4 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is X-5. The ratio of the amount of the supernatant to the amount of the resin is 1:1 (kg / kg). Static adsorption is carried out for 6 h. During static adsorption, intermittent stirring is carried out at 120 rpm, and the adsorption rate is detected by sampling every 2 h. First, elute with pure water. After the color fades, elute with an ethanol solution with a volume fraction of 70%. Collect the eluate and concentrate and dry it to obtain 7.04 kg of a tea pigment product with a tea pigment content of 84.57%. Example 5

[0023] Weigh 60 kg of green tea samples and extract them by means of thermal reflux extraction. Add 1200 L of an ethanol aqueous solution with a volume fraction of 50%. The extraction temperature is 100 °C and the extraction time is 2 h. After the extract is filtered, adjust the pH of the extract to 11 with a sodium hydroxide solution with a mass fraction of 20%, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution until the alcohol content is 70% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 15 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water 4 times the amount of the precipitate for dissolution, then perform crystallization in a crystallization tank at a crystallization temperature of 8 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is ADS-8, and the mass ratio of the supernatant to the resin is 1:0.8 (kg / kg). Perform static adsorption for 6 h. During static adsorption, stir intermittently at 120 rpm, and take samples every 2 h to detect the adsorption rate. First, elute with pure water. After the color fades, elute with an ethanol solution with a volume fraction of 80%. Collect the eluate for concentration and drying to obtain 9.36 kg of a tea pigment product with a tea pigment content of 89.87%. Example 6

[0024] Weigh 60 kg of green tea samples and extract them by means of thermal reflux extraction. Add 1200 L of pure water. The extraction temperature is 100 °C and the extraction time is 4 h. After the extract is filtered, adjust the pH of the extract to 11 with a sodium hydroxide solution with a mass fraction of 20%, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution until the alcohol content is 60% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 4 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water 5 times the amount of the precipitate for dissolution, then perform crystallization in a crystallization tank at a crystallization temperature of 4 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is HPD-450, and the mass ratio of the supernatant to the resin is 1:1.5 (kg / kg). Perform static adsorption for 6 h. During static adsorption, stir intermittently at 120 rpm, and take samples every 2 h to detect the adsorption rate. First, elute with pure water. After the color fades, elute with an ethanol solution with a volume fraction of 95%. Collect the eluate for concentration and drying to obtain 9.97 kg of a tea pigment product with a tea pigment content of 85.12%.

[0025] Comparative Example 1 Weigh 60 kg of green tea samples and extract them by the hot reflux extraction method. Add 300 L of an ethanol aqueous solution with a volume fraction of 10%, with an extraction temperature of 60 °C and an extraction time of 2 h. After the extract is filtered, it is concentrated under reduced pressure to 1 / 5 of the original volume. Ethanol is added to the concentrated solution until the alcohol content is 40% v / v for alcohol precipitation. The alcohol precipitation temperature is controlled at 4 °C and the alcohol precipitation time is 12 h. For the precipitate after alcohol precipitation, add distilled water twice the amount of the precipitate for dissolution and then put it into a crystallization tank for crystallization. The crystallization temperature is 4 °C, and the supernatant is collected. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is D101. The ratio of the amount of the supernatant to the amount of the resin is 1:0.5 (kg / kg). Static adsorption is carried out for 6 h. First, elute with pure water. After the color becomes lighter, collect the eluate and concentrate and dry it to obtain 9.26 kg of a tea pigment product with a tea pigment content of 58.86%.

[0026] Comparative Example 2 Weigh 60 kg of black tea samples and extract them by the hot reflux extraction method. Add 360 L of an ethanol aqueous solution with a volume fraction of 20%, with an extraction temperature of 70 °C and an extraction time of 3 h. After the extract is filtered, adjust the pH of the extract to 10 with a sodium hydroxide solution with a mass fraction of 20% and concentrate it under reduced pressure to 1 / 5 of the original volume. Add distilled water three times the amount for dissolution and then put it into a crystallization tank for crystallization. The crystallization temperature is 6 °C, and the supernatant is collected. The obtained supernatant is adsorbed and eluted with a resin filler. The resin filler selected is AB-8. The ratio of the amount of the supernatant to the amount of the resin is 1:1 (kg / kg). Static adsorption is carried out for 6 h. First, elute with pure water. After the color becomes lighter, elute with 50% ethanol. Collect the eluate and concentrate and dry it to obtain 7.15 kg of a tea pigment product with a tea pigment content of 64.12%.

[0027] Comparative Example 3 Weigh 60 kg of oolong tea samples and extract them by the hot reflux extraction method. Add 600 L of an ethanol aqueous solution with a volume fraction of 30%, with an extraction temperature of 80 °C and an extraction time of 4 h. After the extract is filtered, adjust the pH of the extract to 11 with a sodium hydroxide solution with a mass fraction of 20% and concentrate it under reduced pressure to 1 / 5 of the original volume. Ethanol is added to the concentrated solution until the alcohol content is 60% v / v for alcohol precipitation. The alcohol precipitation temperature is controlled at 10 °C and the alcohol precipitation time is 12 h. For the precipitate after alcohol precipitation, heat and dissolve it with twice the amount of distilled water. The resin filler selected is HPD-100. The ratio of the amount of the supernatant to the amount of the resin is 1:1.5 (kg / kg). Static adsorption is carried out for 6 h. First, elute with pure water. After the color becomes lighter, elute with 60% ethanol. Collect the eluate and concentrate and dry it to obtain 7.86 kg of a tea pigment product with a tea pigment content of 63.44%.

[0028] Comparative Example 4 Weigh 60 kg of Pu-erh tea samples and extract them by the hot reflux extraction method. Add 900 L of ethanol aqueous solution with a volume fraction of 40%, the extraction temperature is 90 °C, and the extraction time is 3 h. After the extract is filtered, adjust the pH of the extract to 10 with 20% sodium hydroxide solution, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution until the alcohol content is 60% v / v for alcohol precipitation. Control the alcohol precipitation temperature at 20 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water three times the amount of the precipitate for dissolution and then put it into a crystallization tank for crystallization. The crystallization temperature is 4 °C, and collect the supernatant. Concentrate and dry the supernatant to obtain 9.49 kg of tea pigment product with a tea pigment content of 61.84%.

[0029] Comparative Example 5 Weigh 60 kg of green tea samples and extract them by the hot reflux extraction method. Add 1200 L of ethanol aqueous solution with a volume fraction of 50%, the extraction temperature is 100 °C, and the extraction time is 2 h. After the extract is filtered, adjust the pH of the extract to 11 with 20% sodium hydroxide solution, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution until the alcohol content is 70% v / v for acidified alcohol precipitation. Adjust the pH of the alcohol solution to 3 with hydrochloric acid. Control the alcohol precipitation temperature at 15 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water four times the amount of the precipitate for dissolution and adjust the pH to 10 with sodium hydroxide, then put it into a crystallization tank for crystallization. The crystallization temperature is 8 °C, and collect the supernatant. Concentrate and dry to obtain 9.97 kg of tea pigment product with a tea pigment content of 54.26%.

[0030] Comparative Example 6 Weigh 60 kg of green tea samples and extract them by the hot reflux extraction method. Add 1200 L of pure water, the extraction temperature is 100 °C, and the extraction time is 4 h. After the extract is filtered, adjust the pH of the extract to 11 with 20% sodium hydroxide solution by mass, and concentrate it under reduced pressure to 1 / 5 of the original volume. Add ethanol to the concentrated solution until the alcohol content is 60% v / v for alcohol precipitation. Adjust the pH of the alcohol solution to 3 with hydrochloric acid. Control the alcohol precipitation temperature at 4 °C and the alcohol precipitation time at 12 h. For the precipitate after alcohol precipitation, add distilled water five times the amount of the precipitate for dissolution and then put it into a crystallization tank for crystallization. The crystallization temperature is 4 °C, and collect the supernatant. The obtained supernatant is adsorbed and eluted with resin filler. The resin filler selected is HPD-450. The ratio of the amount of supernatant to the amount of resin is 1:1.5 (kg / kg). Perform static adsorption for 6 h. First, elute with pure water. After the color becomes lighter, elute with 95% ethanol. Collect the eluate and concentrate and dry to obtain 9.51 kg of tea pigment product with a tea pigment content of 62.14%.

[0031] Table 1. Determination Results of Tea Pigments in Examples

[0032] Table 2. Determination Results of Tea Pigments in Comparative Examples

[0033] The total content of tea pigments in Examples 1 - 6 of the present invention ranges from 83.57% to 89.87%, while the total content of tea pigments in Comparative Examples 1 - 6 is only 54.26% - 64.12%. This indicates that by optimizing the extraction process, especially by adopting the resin filler adsorption and elution steps, the present invention can effectively remove impurities and significantly improve the purity of tea pigments. For example, in Example 5, when using ADS - 8 resin, the total content of tea pigments is as high as 89.87%, which is much higher than the tea pigment content in the comparative examples that do not fully adopt the process of the present invention.

[0034] The yield of tea pigments in the examples of the present invention ranges from 9.92% to 14.14%, and the yields of Examples 5 and 6 exceed 14%. In contrast, the yields of the comparative examples are only 7.64% - 9.84%. This shows that the process design of the present invention (such as the optimization of hot reflux extraction parameters, alcohol precipitation, and crystallization conditions) can extract tea pigments from tea raw materials more fully and reduce the waste of raw materials. For example, in Example 6, using pure water extraction combined with HPD - 450 resin, the yield reaches 14.14%, which is significantly higher than the process in the comparative examples that do not undergo complete alcohol precipitation, crystallization, and resin treatment.

[0035] The present invention does not use acid solution throughout the process, avoiding the formation of tea pigment salts, which is verified by the fact that the salt content of tea pigments in the examples in Table 1 is significantly lower than that in the comparative examples (the salt content in Comparative Examples 5 and 6 increases due to the use of acidification steps). This not only reduces the corrosion of equipment but also reduces waste liquid discharge, making it more in line with environmental protection requirements.

[0036] The crystallization step can effectively remove impurities such as alkaline polysaccharides and reduce the burden on the resin. Comparing the examples with Comparative Example 1 (not alkalized), Comparative Example 2 (not alcohol - precipitated), and Comparative Example 4 (not resin - adsorbed), it can be seen that the complete process removes impurities more thoroughly, and the proportion of components such as tea brown pigment is more reasonable, thus improving the quality of tea pigments.

[0037] The present invention uses static adsorption instead of traditional chromatographic column dynamic analysis. While ensuring the adsorption effect, it significantly reduces the equipment and operation costs. The effectiveness and economy of this method can be seen from the high yields and high purities of Examples 1 - 6.

[0038] Finally, it should be noted that the above - mentioned embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that modifications can still be made to the specific implementation manners of the present application or equivalent replacements can be made to some technical features, and all of them should be covered within the scope of the technical solutions claimed in the present application.

Claims

1. A method for extracting and purifying tea pigment with high content, characterized in that, Weigh the tea raw materials and perform extraction by the hot reflux extraction method. Add an ethanol aqueous solution with a volume fraction of 0 - 50%, the extraction temperature is 60 - 100 °C, and the extraction time is 2 - 4 h. After the extract is filtered, adjust the pH of the extract to 9 - 11 with an inorganic base solution and concentrate it under reduced pressure. Add ethanol to the concentrated solution to make the alcohol content 40% v / v - 70% v / v for alcohol precipitation, and control the alcohol precipitation temperature at 4 - 20 °C. Dissolve the precipitate after alcohol precipitation with added distilled water, then crystallize in a crystallization tank, and collect the supernatant. The obtained supernatant is adsorbed and eluted with a resin filler, with static adsorption for 4 - 10 h. First, elute with pure water, and then elute with ethanol with a volume fraction of 50 - 95%. Collect the eluate and concentrate and dry it to obtain a tea pigment product with a tea pigment content ≥ 80%.

2. The high-content tea pigment extraction and purification method according to claim 1, characterized in that, The selected tea raw material is any one of green tea, black tea, oolong tea, and pu-erh tea.

3. The high-content tea pigment extraction and purification method according to claim 1, characterized in that, The alcohol precipitation time is 10 - 20 h.

4. The high-content tea pigment extraction and purification method according to claim 1, characterized in that, During dissolution, add distilled water 2 - 5 times the amount of the precipitate for dissolution.

5. The high-content tea pigment extraction and purification method according to claim 1, characterized in that, The crystallization temperature is 4 - 10 °C.

6. The high-content tea pigment extraction and purification method according to claim 1, characterized in that The resin filler is selected from any one of D101, AB-8, HPD-100, X-5, ADS-8, and HPD-450.

7. The method for extracting and purifying high-content tea pigment according to claim 1, characterized in that, The mass ratio of the supernatant to the resin is 1:0.5 - 1.

5.

8. The high-content tea pigment extraction and purification method according to claim 1, characterized in that, The inorganic base solution is a sodium hydroxide solution with a mass fraction of 15 - 25%.

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