Method for improving stability of epigallocatechin gallate

Abstract

The invention provides a method for improving the stability of epigallocatechin gallate. According to the method for improving the stability of the epigallocatechin gallate, the prepared water-oil amphiphilic alginate fiber, the water and the tea extract are subjected to high-shear homogenization treatment, so that the stability of the EGCG at different temperatures and pH values is improved. The water-oil amphiphilic seaweed cellulose is obtained by modifying a seaweed extract with wheat germ oil. The EGCG in the tea extract is protected by using the water-oil amphiphilic seaweed cellulose, so that the stability of the EGCG at different temperatures and different pH values is improved, and the EGCG can maintain the stability and activity at different temperatures and pH values when the tea extract is used for preparing different products, so that the application range of the tea extract is widened.

Description

Technical Field

[0001] The present invention relates to a method for improving the stability of epigallocatechin gallate. Background Art

[0002] Epigallocatechin gallate (EGCG) is a kind of tea polyphenol active ingredient extracted from green tea and belongs to catechins. Due to its special stereochemical structure, EGCG has very strong antioxidant activity, the performance of anti-free radical DNA damage, anti-radiation and anti-ultraviolet rays. At the same time, it can also prevent lipid peroxidation and reduce the contents of low-density cholesterol, very low-density cholesterol and triglyceride in serum.

[0003] However, during the traditional manufacturing process and storage conditions of tea leaves, they are susceptible to the influence of high temperature, light, humidity and pH. A series of complex chemical reactions will occur to the internal chemical components. Moreover, the stability of EGCG itself is poor. During the processing and storage of tea beverages, it is susceptible to the influence of factors such as temperature and pH, and reactions such as degradation, oxidation and isomerization will occur, thus changing its original physiological activity. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a method for improving the stability of epigallocatechin gallate. By preparing a water-oil amphiphilic seaweed fiber and performing high-shear homogenization treatment with water and tea extract, the stability of EGCG at different temperatures and pH values can be improved.

[0005] To solve the above technical problem, the present invention is realized through the following technical solutions: A preparation method of a cellulose water microdrop EGCG emulsion, which includes adding a tea extract and a water-oil amphiphilic seaweed cellulose into water for high-shear homogenization, fully fusing the two to obtain a primary emulsion, and then adding vegetable oil to the primary emulsion and continuing homogenization to make each component fully fuse.

[0006] The water-oil amphiphilic seaweed cellulose is obtained by modifying a seaweed extract with wheat germ oil for lipophilic modification.

[0007] In the present invention, the addition amount of the tea extract is determined according to its dissolution amount in the water phase or oil phase and the EGCG concentration. The concentrated crystallization of the tea extract is rich in EGCG, and the mass-volume ratio of the tea extract to water is (0.03 - 0.05):4 - 6 (m / v).

[0008] Preferably, the volume ratio of the water-oil amphiphilic seaweed cellulose to water is 1:4 - 6 (v / v), preferably 1:5 (v / v).

[0009] Preferably, the volume ratio of the primary emulsion to the vegetable oil is 1:3 - 5 (v / v), preferably 1:4 (v / v).

[0010] Preferably, during homogenization, the rotation speed of the homogenizer is 4000 r / min or above.

[0011] In the present invention, the tea extract is rich in EGCG. The extraction method of the tea extract can adopt any current extraction method that can obtain a rich EGCG content. As a preferred embodiment, the method for preparing a tea extract rich in EGCG in the present invention is as follows: (1) First soaking of tea leaves: Put the tea leaves into a mixed solution of glucose and fructose. First, treat them under a negative pressure condition of 0.08 MPa - 0.1 MPa for 20 - 30 min, then conduct the first soaking under normal temperature and pressure conditions, and then perform solid-liquid separation to remove the filtrate to obtain the tea leaves after the first soaking; the first soaking is a liquid-solid extraction process, and its purpose is to remove impurities in the tea leaves through negative pressure replacement. Under negative pressure conditions, the penetration ability and diffusion ability of the solvent to the tea leaves are enhanced, enabling the impurities in the tea leaves to dissolve more quickly. Preferably, in the first soaking, the mixed solution of glucose and fructose includes 20 - 30% glucose, 5 - 10% fructose, and the balance water; Preferably, in the first soaking, the mass-to-volume ratio between the tea leaves and the mixed solution of glucose and fructose is (0.5 - 1.5):(0.5 - 1.5); Preferably, the time for the tea leaves to be soaked once is 20 - 30 h.

[0012] (2) Second soaking of tea leaves: Put the tea leaves after the first soaking into water for the second soaking to fully dissolve the active ingredients in the tea leaves in the water, and perform solid-liquid separation to filter out the tea leaves to obtain a tea extract rich in EGCG.

[0013] Preferably, in the second soaking, the mass-to-volume ratio between the tea leaves and water is (0.5 - 1.5):(5 - 15), the soaking temperature is 70 - 90 °C, and the soaking time is 3 - 5 h; (3) Concentrating and crystallizing the tea extract: Use a rotary evaporator to concentrate and crystallize the tea extract. Among them, the reaction conditions are: a vacuum negative pressure of 0.08 MPa - 0.09 MPa, a water bath temperature of 60 °C, adjust the rotation speed according to the boiling state of the liquid, and the maximum rotation speed is 12, and finally obtain a tea extract rich in EGCG.

[0014] In the present invention, the preparation method of the water-oil amphiphilic algal cellulose includes the following steps: (1) After drying the washed seaweed, mix it with water to make a slurry to obtain an alginate dispersion; preferably, the mass-to-volume ratio between the seaweed and water is 1:(20 - 40).

[0015] Since red algae has a high content of galactose sulfate (carrageenan), there is no need to add additional thickeners and adhesives. In addition, red alginate contains a large amount of soluble dietary fiber or substances with the characteristics of water-soluble dietary fiber, which has the effects of lowering blood sugar and promoting digestion, thereby increasing the absorption of the encapsulated substance (i.e., EGCG). Coupled with the easy availability and low cost of red algae, the seaweed of the present invention is preferably red algae.

[0016] (2) Perform low-temperature stirring treatment at 4 - 8 °C and high-temperature membrane evaporation treatment at 75 - 85 °C on the alginate dispersion in sequence, and uncover the membrane to obtain the crude seaweed extract. (3) Treat the crude seaweed extract and vegetable oil used for lipophilic modification in a double-cone rotary reactor for 24 hours at a treatment temperature of 40 - 50 °C. After completion, perform oil removal treatment (take out the vegetable oil precipitated in the upper layer of the mixture treated in the double-cone rotary reactor, and then centrifugation can complete the oil removal operation) to obtain water-oil amphiphilic seaweed cellulose, that is, a natural surfactant.

[0017] In the present invention, the vegetable oil used for lipophilic modification is wheat germ oil. Wheat germ oil is a vegetable oil rich in nutrients, and its components mainly include fatty acids, tocopherols (vitamin E), phytosterols and other bioactive substances. Among them, linoleic acid is the main component in the composition of fatty acids, accounting for 42%-64.82%. For example, the linoleic acid content in low-gluten wheat germ oil extracted by supercritical CO2 can reach 58.23%. "When a hydrophobic segment is added to a hydrophilic polymer chain, an amphiphilic copolymer is synthesized. In an aqueous solution, amphiphilic molecules self-orient to reach the minimum free energy state, and the hydrophobic block is removed from the water environment. Therefore, polymer micelles with a core / shell structure are formed. Since their hydrophobic domains are surrounded by a hydrophilic outer shell, they can serve as reservoirs for various hydrophobic drugs" (A. Martínez, Polysaccharide-Based Nanoparticles for Controlled Release Formulations, 2012, P202). The linoleic acid with the highest content in wheat germ oil contains hydrophobic groups (lipophilic), while the hydrophilic groups are contained in algal cellulose (a polysaccharide). When the two are mixed, a hydrophilic-lipophilic copolymer is formed. "Some long-chain fatty acids, such as caproic acid, linoleic acid, linolenic acid, palmitic acid or stearic acid, etc. have been used to modify polysaccharides and obtain polymer micelles" (A. Martíne, Polysaccharide-Based Nanoparticles for Controlled Release Formulations, 2012, the fourth paragraph of P202). The present invention utilizes the lipophilic-hydrophobic groups of wheat germ oil and mixes them with the hydrophilic groups of polysaccharides to form a hydrophilic-lipophilic copolymer, thus completing the lipophilic modification of algal cellulose by wheat germ oil.

[0018] Based on the above content, it can be known that amphiphilic algal cellulose can be used to improve the stability of EGCG in tea extracts, including at least one of the temperature stability and pH stability of EGCG.

[0019] The beneficial effects of the above technical solutions of the present invention are as follows: The present invention uses amphiphilic algal cellulose to protect EGCG in tea extracts, thereby improving the stability of EGCG at different temperatures and different pH values, enabling EGCG to maintain stability and activity under different temperature and pH treatments when tea extracts are used to prepare different products, and thus expanding the application range of tea extracts. Description of the Drawings

[0020] Figure 1 Schematic diagram of the preparation process of the tea extract in Example 1; Figure 2Schematic diagram of the preparation process of the seaweed cellulose in Example 2; Figure 3 Schematic diagram of the preparation process of the cellulose aqueous microdroplet EGCG emulsion; Figure 4 Dyeing diagram of the cellulose aqueous microdroplet EGCG emulsion in Example 3; Figure 5 Zeta potential analysis diagram of the cellulose aqueous microdroplet EGCG emulsion in Example 3; Figure 6 Variation diagram of the EGCG content in the cellulose aqueous microdroplet EGCG emulsion in Example 3 at different temperatures; Figure 7 Variation diagram of the EGCG content in the cellulose aqueous microdroplet EGCG emulsion in Example 3 at different pH values. Specific implementation manners

[0021] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to specific embodiments.

[0022] The object of the present invention is to improve the stability of EGCG, and thus a cellulose aqueous microdroplet EGCG emulsion is proposed. The preparation method includes adding a tea extract and amphiphilic seaweed cellulose into water for high-shear homogenization, and fully fusing the two to obtain a primary emulsion, and then adding vegetable oil to the primary emulsion and continuing to homogenize to make all components fully fuse. The amphiphilic seaweed cellulose is obtained by modifying a seaweed extract with wheat germ oil used for completing lipophilic modification.

[0023] The concentrated crystallization of the tea extract is rich in EGCG, and the mass-volume ratio (g / mL) of the tea extract to water is (0.03 - 0.05):(4 - 6).

[0024] The volume ratio (mL / mL) of the amphiphilic seaweed cellulose to water is 1:(4 - 6), preferably 1:5; the volume ratio of the primary emulsion to the vegetable oil is 1:3 - 5, preferably 1:4.

[0025] During homogenization, the rotation speed of the homogenizer is 4000 r / min or above.

[0026] The method for the tea extract is as follows: (1)The first soaking of tea leaves: The tea leaves are put into a mixed solution of glucose and fructose, first treated under a negative pressure condition of 0.08 MPa - 0.1 MPa for 20 - 30 min, then soaked for the first time under normal temperature and pressure conditions, and then the solid-liquid separation is carried out to remove the filtrate to obtain the tea leaves after the first soaking; The first soaking is a liquid-solid extraction process, and its purpose is to remove impurities in the tea leaves through negative pressure replacement. Under negative pressure conditions, the penetration ability and diffusion ability of the solvent to the tea leaves are enhanced, and the impurities in the tea leaves can be dissolved out more quickly; In the first soaking, the mixed solution of glucose and fructose includes 20 - 30% of glucose, 5 - 10% of fructose and the balance of water; The mass-to-volume ratio (kg / L) between the tea leaves and the mixed solution of glucose and fructose is (0.5 - 1.5):(0.5 - 1.5); The soaking time is 20 - 30 h.

[0027] (2)The second soaking of tea leaves: The tea leaves after the first soaking are put into water for the second soaking to fully dissolve the effective components in the tea leaves in water, and the tea leaves are filtered out by solid-liquid separation to obtain a tea leaf extract rich in EGCG. In the second soaking, the mass-to-volume ratio (kg / L) between the tea leaves and water is (0.5 - 1.5):(5 - 15), the soaking temperature is 70 - 90 °C, and the soaking time is 3 - 5 h; (3)Concentrating and crystallizing the tea leaf extract: Using a rotary evaporator to concentrate and crystallize the tea leaf extract, wherein, the reaction conditions are: a vacuum negative pressure of 0.08 MPa - 0.09 MPa, a water bath temperature of 60 °C, adjusting the rotation speed according to the boiling state of the liquid, and the maximum rotation speed is 12, and finally a tea leaf extract rich in EGCG is obtained.

[0028] The preparation method of the water-oil amphiphilic algal cellulose includes the following steps: (1)After drying the washed seaweed, it is mixed with water to make a pulp to obtain an alginate dispersion; The mass-to-volume ratio (g / mL) between the seaweed and water is 1:(20 - 40).

[0029] Because red algae has a high content of galactose sulfate (carrageenan), there is no need to add additional thickeners and adhesives. In addition, red alginate contains a large amount of soluble dietary fiber or substances with the characteristics of water-soluble dietary fiber, which has the effects of lowering blood sugar and promoting digestion, thereby increasing the absorption of the encapsulated substance (i.e., EGCG). Coupled with the easy availability and low cost of red algae, the seaweed of the present invention is preferably red algae.

[0030] (2)The alginate dispersion is successively subjected to low-temperature stirring treatment at 4 - 8 °C and high-temperature membrane evaporation treatment at 75 - 85 °C, and the film is removed to obtain a crude algal extract; (3) Treat the crude seaweed extract and the vegetable oil used for lipophilic modification in a double-cone rotary reactor for 24 hours at a treatment temperature of 40 - 50°C. After completion, perform oil removal treatment (take out the vegetable oil precipitated on the upper layer of the mixture treated in the double-cone rotary reactor, and then centrifugation can complete the oil removal operation) to obtain a water-oil amphiphilic seaweed cellulose, that is, a natural surfactant.

[0031] The tea leaves (or tea powder) involved in the present invention are selected from Dianqing tea produced in Lincang, Yunnan.

[0032] Example 1 Preparation method of tea extract rich in EGCG, comprising the following steps: (1) First soaking of tea leaves: Put the tea leaves into a mixed solution of glucose and fructose, first treat under a negative pressure condition of 0.08 MPa - 0.1 MPa for 20 - 30 min, then perform the first soaking under normal temperature and pressure conditions, and then perform solid-liquid separation to remove the filtrate to obtain the tea leaves after the first soaking; In the first soaking, the mixed solution of glucose and fructose comprises 25% glucose, 8% fructose and the balance of water; the mass-to-volume ratio between the tea leaves and the mixed solution of glucose and fructose is 1 kg:1 L; the soaking time of the tea leaves for the first time is 25 h to fully remove impurities in the tea leaves.

[0033] (2) Second soaking of tea leaves: Put the tea leaves after the first soaking into clean water for the second soaking to fully dissolve the active ingredients in the tea leaves in water, perform solid-liquid separation to filter out the tea leaves, and obtain a tea extract rich in EGCG. In the second soaking, the mass-to-volume ratio between the tea leaves and water is 1 kg:10 L, the soaking temperature is 80°C, and the soaking time is 4 h; (3) Concentrate and crystallize the tea extract: Use a rotary evaporator to concentrate and crystallize the tea extract. Among them, the reaction conditions are: vacuum negative pressure of 0.08 MPa - 0.09 MPa, water bath temperature of 60°C, adjust the rotation speed according to the boiling state of the liquid, and the maximum rotation speed is 12, and finally obtain a tea extract rich in EGCG.

[0034] Example 2 Preparation method of water-oil amphiphilic seaweed cellulose, comprising the following steps: (1) After drying the washed red algae, mix it with water and beat to obtain an alginate dispersion; the mass-to-volume ratio between the red algae and water is 1 g:30 mL.

[0035] (2) Perform low-temperature stirring treatment at 4 - 8°C and high-temperature membrane evaporation treatment at 75 - 85°C on the alginate dispersion in sequence, and uncover the membrane to obtain the crude seaweed extract; (3) Treat the crude seaweed extract and wheat germ oil in a double-cone rotary reactor for 24 hours at a treatment temperature of 40 - 50°C. After completion, take out the wheat germ oil separated out from the upper layer of the mixture in the double-cone rotary reactor, and then centrifuge to complete the oil removal operation, obtaining amphiphilic seaweed cellulose, i.e., a natural surfactant.

[0036] Example 3 A method for preparing a cellulose aqueous microdroplet EGCG emulsion, comprising the following steps: (1) Add the tea extract of Example 1 and the amphiphilic seaweed cellulose of Example 2 to water for high-shear homogenization, and fully blend the two to obtain a primary emulsion; (2) Add wheat germ oil to the primary emulsion and continue homogenization to fully blend all components.

[0037] In this example, in step (1), the addition amount of the tea extract is 0.04 g, the addition amount of water is 5 mL, and the addition amount of the amphiphilic seaweed cellulose is 1 mL; In step (2), add vegetable oil with a volume 4 times that of the primary emulsion obtained in step (1) to the primary emulsion obtained in step (1).

[0038] The rotation speed of the homogenizer used for homogenization is at least 4000 r / min.

[0039] The product prepared is stained with rhodamine as shown in Figure 4 shown. Lipids (yellow) can indicate that the membrane is a lipid, and the presence of spheres indicates encapsulation.

[0040] Stability detection ① Mix 2 g of the cellulose aqueous microdroplet EGCG emulsion prepared in Example 3 with 100 mL of water at 50°C and let it stand at room temperature for 30 min, then filter through a 0.45 μm filter membrane. The resulting liquid is the test solution of the cellulose aqueous microdroplet EGCG emulsion mixture.

[0041] ② Mix 2 g of tea powder with 100 mL of water at 50°C and let it stand at room temperature for 30 min, then filter through a 0.45 μm filter membrane. The resulting liquid is the test solution of the fresh tea infusion, serving as a comparative example.

[0042] ③ Adjust the pH with ammonia water and hydrochloric acid, and detect the content after standing for 0, 1, 3, and 7 days respectively; adjust the temperature with a refrigerator and a water bath, and detect the content after standing for 0, 1, 7, and 14 days respectively.

[0043] The method for detecting the content of EGCG is reverse-phase liquid chromatography. The detection reagents include: pure water, glacial acetic acid, methanol, and EGCG standard; The preparation method of the EGCG standard is: weigh 10.0 mg of the EGCG standard substance and dissolve it in a 3% glacial acetic acid solution to make up to 100 mL.

[0044] The specific steps for detecting the content of EGCG by reverse-phase liquid chromatography are as follows: The example group and the comparative example group are respectively filtered through a 0.45 μm filter membrane and then detected by liquid chromatography to obtain the peak area of the detected EGCG, and the content of EGCG in the sample is calculated according to the formula "standard EGCG peak area / standard EGCG concentration = sample EGCG peak area / sample EGCG concentration".

[0045] The liquid chromatography detection conditions are as follows: Use a 250 mm × 4.5 mm stainless steel column filled with a 5 μm C18 bonded stationary phase; mobile phase A is methanol, and mobile phase B is a 3% glacial acetic acid solution; the excitation wavelength is 280 nm; the flow rate is set to 1.0 mL / min; the column temperature is 40 °C; the injection volume is 10 μL.

[0046] The gradient of the mobile phase of the reverse-phase liquid chromatography is as follows:

[0047] The formula for calculating the stability of EGCG under different conditions is: Stability of EGCG on the Nth day (%) = (Content of EGCG on the Nth day / Content of EGCG on the 0th day) × 100%.

[0048] Performance verification: Perform a Zeta potential analysis experiment on the cellulose aqueous microdroplet EGCG emulsion obtained in Example 3, as Figure 5 shown. The lowest potential values obtained from repeating the test 3 times are -90.2 mV, -94.5 mV, and -86.7 mV respectively, indicating that the emulsion has strong stability.

[0049] Stability results The results of the temperature stability test are as Figure 6 shown. Under different temperature conditions, the long-term placement of the tea infusion at 4 °C and 25 °C will cause the content of EGCG in the tea to decrease and fluctuate, which may be caused by degradation or transformation. However, the results show that the cellulose aqueous microdroplet EGCG emulsion can protect and stabilize EGCG and prevent its degradation and transformation.

[0050] The results of the pH stability test are as Figure 7As shown, in an acidic environment (pH = 2 or 4), EGCG in the cellulose aqueous microdroplet EGCG emulsion and the tea infusion is relatively stable, and there is no significant decrease in EGCG. In a slightly neutral environment (pH = 6 or 7 or 8), the content of EGCG in the tea infusion shows significant fluctuations and decreases, while the cellulose aqueous microdroplet EGCG emulsion effectively reduces the occurrence of this instability. In an alkaline environment (pH = 10), although there is no significant decrease in EGCG in both groups, in a stronger alkaline environment (pH = 12), a large amount of EGCG in the tea infusion decreases, while although there is a decrease in EGCG in the cellulose aqueous microdroplet EGCG emulsion, it is not serious. Therefore, it can be determined that the cellulose aqueous microdroplet EGCG emulsion increases the stability of EGCG in tea under different pH conditions, which is of great significance in overcoming the influence of temperature or pH during the production or preservation of products containing EGCG.

[0051] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Use of amphiphilic algal cellulose in improving the stability of epigallocatechin gallate, characterized in that, The amphiphilic algal cellulose is obtained by modifying an algal extract with wheat germ oil used for lipophilic modification.

2. The application according to claim 1, wherein The preparation method of the amphiphilic algal cellulose comprises the following steps: (1) After drying the washed algae, mix them with water and beat to obtain an alginate dispersion; (2) Subject the alginate dispersion to stirring treatment and membrane evaporation treatment in sequence, and uncover the membrane to obtain a crude algal extract; (3) Treat the crude algal extract with wheat germ oil used for lipophilic modification in a double-cone rotary reactor for 24 h at a treatment temperature of 40 - 50 °C, and perform oil removal treatment after completion to obtain the product; Wherein, the temperature of the stirring treatment is 4 - 8 °C; the temperature of the membrane evaporation treatment is 75 - 85 °C.

3. The use according to claim 2, characterized in that, The algae is red algae; The mass-to-volume ratio between the algae and water is 1:(20 - 40).

4. A preparation method of a cellulose aqueous microdroplet EGCG emulsion, characterized in that, Comprises the following steps: Add the tea extract and the amphiphilic algal cellulose to water and perform high-shear homogenization so that the two are fully fused to obtain a primary emulsion; Then add wheat germ oil to the primary emulsion and continue homogenization to make all components fully fused; The amphiphilic algal cellulose is obtained by modifying an algal extract with wheat germ oil used for lipophilic modification.

5. The preparation method according to claim 4, characterized in that, The mass-to-volume ratio of the tea extract to water is (0.03 - 0.05):(4 - 6); The volume ratio of the amphiphilic algal cellulose to water is 1:(4 - 6); The volume ratio of the primary emulsion to vegetable oil is 1:(3 - 5); The rotation speed of the homogenizer during homogenization is 4000 r / min or above.

6. The preparation method according to claim 4, characterized in that, The preparation method of the tea extract comprises the following steps: (1) First soaking of tea: Put the tea into a mixed solution of glucose and fructose, first treat it under a negative pressure condition of 0.08 MPa - 0.1 MPa for 20 - 30 min, then perform the first soaking under normal temperature and pressure conditions, and then perform solid-liquid separation to remove the filtrate to obtain the tea after the first soaking; (2) Second soaking of tea: Put the tea after the first soaking into water for the second soaking to fully dissolve the active ingredients in the tea in water, perform solid-liquid separation to filter out the tea, and obtain a tea leachate rich in EGCG; (3) Concentrate and crystallize the tea leachate: Use a rotary evaporator to concentrate and crystallize the tea leachate. Among them, the reaction conditions are: vacuum negative pressure 0.08 MPa - 0.09 MPa, water bath temperature 60 °C, adjust the rotation speed according to the boiling state of the liquid, and the maximum rotation speed is 12, and finally obtain a tea extract rich in EGCG.

7. The preparation method according to claim 4, characterized in that, The preparation method of the amphiphilic algal cellulose comprises the following steps: (1) After drying the washed algae, mix them with water and beat to obtain an alginate dispersion; (2) Subject the alginate dispersion to stirring treatment and membrane evaporation treatment in sequence to obtain a crude algal extract; (3) Treat the crude seaweed extract and wheat germ oil used for lipophilic modification in a double-cone rotary reactor for 24 h at a treatment temperature of 40 - 50 °C. After completion, remove the oil to obtain amphiphilic seaweed cellulose; Among them, the seaweed is red algae; The temperature of the stirring treatment is 4 - 8 °C; the temperature of the film evaporation treatment is 75 - 85 °C.

8. The preparation method according to claim 4, wherein In the first soaking of tea leaves, the mixed solution of glucose and fructose contains 20 - 30% of glucose, 5 - 10% of fructose and the balance of water; the mass-to-volume ratio between the tea leaves and the mixed solution of glucose and fructose is (0.5 - 1.5):(0.5 - 1.5); the soaking time is 20 - 30 h.

9. The preparation method according to claim 4, wherein In the second soaking of tea leaves, the mass-to-volume ratio between the tea leaves and water is (0.5 - 1.5):(5 - 15); the soaking temperature is 70 - 90 °C; the soaking time is 3 - 5 h.

10. A cellulose aqueous microdroplet EGCG emulsion, characterized in that, It is prepared by the preparation method according to any one of claims 4 - 9.

Images