A tea polyphenol extract extracted by supramolecular DES and its preparation method and use

Abstract

The present invention provides a tea polyphenol extract, which uses a supramolecular low eutectic solvent (SUPRADES) to extract tea polyphenols from tea leaves, the extraction rate of tea polyphenols in the extract is not less than 109.05 mg / g, and the content of tea polyphenols in the extract is not less than 1.67 mg / mL. The present invention also provides an extraction method and use of the tea polyphenol extract, as well as a tea polyphenol hydrogel biofilm. The extraction rate of tea polyphenols in the present invention is high, and the extraction process is simple; the present invention uses safe and non-toxic chitosan and polyvinyl alcohol as film-forming materials, and directly prepares the tea polyphenol SUPRADES extract into a functional biofilm of tea polyphenols, which can be developed into a composite membrane of antioxidant functional tea polyphenols, and no organic solvent is used in the entire process, with high safety and simple operation.

Description

Technical Field

[0001] The invention relates to a tea polyphenol extract extracted by supramolecular DES, a preparation method and application thereof. Background Art

[0002] Tea polyphenols (TPPs) are a class of polyphenolic compounds found in tea leaves, exhibiting a variety of biological activities, including antioxidant, anti-inflammatory, and anti-tumor properties. Tea polyphenols are composed of over 30 phenolic compounds, primarily classified into four categories: catechins, flavonoids, anthocyanins, and phenolic acids. Catechins are the most abundant of all tea polyphenols, accounting for 60% to 80% of the total. Catechins primarily include epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG). Tea polyphenols scavenge reactive oxygen free radicals, block lipid peroxidation, and enhance enzyme activity in the body, acting as anti-mutagenic and anti-cancer agents. Furthermore, tea polyphenols may help prevent and treat diseases caused by hyperlipidemia and enhance overall immunity. Traditional methods for preparing tea polyphenols from tea include solvent extraction, ion precipitation, and column separation. Supercritical CO2 extraction technology combined with traditional extraction technology can produce high-purity tea polyphenols that meet the requirements of industrial production.

[0003] Supermolecular deep eutectic solvents (SUPRADES) are a new subclass of deep eutectic solvents (DES). They exhibit unique supramolecular properties by incorporating supramolecular compounds such as cyclodextrins. These solvents have attracted considerable attention due to their green composition, tunable physicochemical properties, and supramolecular interactions, and may have a significant impact on the development of green chemistry. SUPRADES are composed of green components and have physicochemical properties similar to traditional DES, but through supramolecular interactions such as host-guest interactions, they allow for the selective binding of a wide range of compounds. Compared to traditional DES, SUPRADES have demonstrated higher efficiency in many applications. SUPRADES hold great promise for application, being described as completely green, non-toxic, and biodegradable solvents capable of efficiently absorbing a wide range of substances.

[0004] Application number: 201810809794.4, invention name: A low eutectic solvent and extraction process for extracting tea polyphenols from tea seed meal, providing a low eutectic solvent and extraction process for extracting tea polyphenols from tea seed meal, relating to the technical field of tea polyphenol extraction, wherein the low eutectic solvent is prepared by mixing glycerol, proline and citric acid in a molar ratio of (4-6): (1.5-2.5): (0.1-0.3); the extraction steps of tea polyphenols are as follows: (1) pretreatment of tea seed meal, (2) preparation of DSE aqueous solution, (3) crude extraction of tea polyphenols, (4) refined extraction of tea polyphenols, (5) concentration, and (6) drying; the present invention adopts a low eutectic solvent as an extractant in combination with the extraction process of tea polyphenols, which not only improves the extraction efficiency of tea polyphenols, improves the utilization rate of raw materials, reduces the production cost of tea polyphenols, but also is beneficial to the subsequent purification process of tea polyphenols, which is a crude extract obtained by DES extraction and then refined to obtain a tea polyphenol extract.

[0005] Application number: 202410217145.0, Invention name: A method for extracting tea polyphenols from tea leaves, providing a method for extracting tea polyphenols from tea leaves, belonging to the technical field of natural product purification. The extract of tea polyphenols is obtained by combining DES with a two-phase aqueous extraction method. The low eutectic solvent selected by the present invention changes the structure and properties of DES by controlling the types and ratios of hydrogen bond acceptors and hydrogen bond donors, so that the two-phase aqueous system constructed by it and n-propanol has the advantages of both a low eutectic solvent and two-phase aqueous extraction, so that the system has mild conditions, good biocompatibility, low viscosity, not easy to emulsify, low cost and good extraction effect for tea polyphenols. Application number: 201810982234.9, A method for extracting tea polyphenols, which uses microwave, ball milling, supercritical fluid extraction and other methods to prepare tea polyphenols. Provided is a method for extracting tea polyphenols. The method comprises the following steps: first, washing and drying tea leaves, crushing and sieving the leaves to prepare tea powder; then, subjecting the tea powder to microwave treatment, mixing the mixture with an aqueous solution of a low eutectic reagent, subjecting the mixture to ball mill mechanical extraction, and collecting the supernatant; adding a K2HPO4 aqueous solution to the supernatant, performing vortex centrifugation to separate the phases, removing the upper phase, and concentrating the upper phase under reduced pressure; finally, purifying the concentrated solid using a supramolecular solvent and supercritical fluid extraction, and then freeze-drying the solid to obtain natural tea polyphenols. Summary of the Invention

[0006] The invention relates to a tea polyphenol extract extracted by supramolecular DES, a preparation method and application thereof.

[0007] The present invention provides a tea polyphenol extract, which uses a supramolecular deep eutectic solvent (SUPRADES) to extract tea polyphenols from tea leaves. The extraction rate of tea polyphenols in the extract is not less than 109.05 mg / g, and the content of tea polyphenols in the extract is not less than 1.67 mg / mL.

[0008] Further preferably, the extraction rate of tea polyphenols in the extract is 111.36±2.31 mg / g, and the content of tea polyphenols in the extract is 1.72±0.05 mg / mL.

[0009] The hydrogen bond donor (HBD) in the supramolecular DES is one of β-cyclodextrin, hydroxypropyl-β-CD, and γ-cyclodextrin; the hydrogen bond acceptor (HBA) is one of L-lactic acid, levulinic acid, and glycerol; and the weight ratio is:

[0010] Hydrogen bond donor (HBD): hydrogen bond acceptor (HBA) = 1: (1-15).

[0011] Further preferably, the hydrogen bond donor (HBD) in the supramolecular DES is hydroxypropyl-β-CD; the hydrogen bond acceptor (HBA) is L-lactic acid; and the weight ratio thereof is:

[0012] Hydroxypropyl-β-CD:L-lactic acid=1:5.

[0013] The present invention also provides a method for preparing the tea polyphenol extract, which comprises the following steps:

[0014] a. Preparation of SUPRADES extraction solvent: Weigh the hydrogen bond acceptor and hydrogen bond donor according to the mass ratio, mix, add water, stir at 80°C, and vacuum dry at 60°C.

[0015] b. Take tea powder, add SUPRADES extraction solvent prepared in step a, and perform ultrasonic extraction;

[0016] c. Centrifuge and take the supernatant to obtain the tea polyphenols extract.

[0017] The ultrasonic conditions are as follows: ultrasonic time 30-60 min; water content in SUPRADES 40-70%; liquid-to-solid ratio of tea leaves to SUPRADES extraction solvent 1: (10-70) g / mL.

[0018] Further preferably, the ultrasonic conditions are: ultrasonic time 54 min; water content in SUPRADES is 40%; liquid-to-solid ratio of tea leaves to SUPRADES extraction solvent is 1:66 g / mL;

[0019] The centrifugal conditions are: 4000 r / min for 10 min.

[0020] The present invention also provides the use of the tea polyphenol extract in preparing medicines or health products with antioxidant effects.

[0021] The invention provides a tea polyphenol hydrogel biofilm, which contains the tea polyphenol extract and is prepared by adding matrix auxiliary materials acceptable to film preparations.

[0022] The matrix excipients include chitosan, polyvinyl alcohol, gelatin, sodium carboxymethyl cellulose (CMC-Na), methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), glutaraldehyde, formaldehyde, glycerol, propylene glycol, sodium dihydrogen phosphate, ethyl hydroxybenzoate, phenoxyethanol, and carbomer; preferably, the matrix excipients are chitosan and polyvinyl alcohol.

[0023] The SUPRADES extraction solvent of the present invention is composed of hydroxypropyl-β-CD and L-lactic acid. Compared with other DES, SUPRADES has a more extensive hydrogen bond network and exhibits unique supramolecular properties. The present invention utilizes SUPRADES in conjunction with ultrasonic extraction to produce a tea polyphenol extract, enabling direct production of a tea polyphenol biofilm without intermediate purification steps.

[0024] The advantages of the present invention are as follows:

[0025] 1. High extraction rate of tea polyphenols: The present invention adopts the green and safe SUPRADES as the extraction solvent. Through the optimization of extraction conditions, under the optimal extraction conditions, the extraction rate of tea polyphenols is 111.36±2.31mg / g, which is much higher than the extraction efficiency when using traditional extraction solvents (water, 60% ethanol).

[0026] 2. Simple extraction process: Compared with the above three reported inventions, the present invention directly adopts ultrasonic extraction method to obtain tea polyphenol extract. The instruments and equipment used are widely available, the operation is simple, and the extraction efficiency is high.

[0027] 3. The present invention uses safe and non-toxic chitosan and polyvinyl alcohol as film-forming materials, and directly prepares the tea polyphenol SUPRADES extract into a functional tea polyphenol biofilm, which can be developed into a composite membrane of tea polyphenols with antioxidant functionality. In addition, no organic solvents are used in the entire process, which is highly safe and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 .Gallic acid standard curve;

[0029] Figure 2 A shows the effect of different extraction solvents on the extraction rate of tea polyphenols; B shows the effect of different mass ratios of HP-LA on the extraction rate of tea polyphenols (n=3) (Note: Different letters indicate significant differences (P<0.05)).

[0030] Figure 3 Effect of water content in HP-LA on the extraction rate of tea polyphenols (n=3) (Note: Different letters indicate significant differences (P<0.05));

[0031] Figure 4 Effects of different extraction solvents and HP-LA mass ratios on the extraction rate of tea polyphenols (n=3) (Note: Different letters indicate significant differences (P<0.05));

[0032] Figure 5 Effects of different extraction times on the extraction rate of tea polyphenols (Note: different letters indicate significant differences (P < 0.05);

[0033] Figure 6 Effects of different interaction factors on polyphenol extraction efficiency (A: volume fraction and liquid-to-solid ratio, B: volume fraction and ultrasonic time, C: liquid-to-solid ratio and ultrasonic time);

[0034] Figure 7 .Samples obtained with different film-forming times (A is 1h, B is 2~6h). DETAILED DESCRIPTION

[0035] Example 1 Screening test of the extraction process of tea polyphenols using SUPRADES of the present invention

[0036] 1. Preparation of SUPRADES

[0037] SUPRADES was prepared by solvent evaporation method: hydrogen bond acceptor (HBD) and hydrogen bond donor (HBA) were weighed and mixed in a mass ratio of 1:5, an appropriate amount of water was added, and the mixture was stirred at 80°C for 30 minutes, and then vacuum dried at 60°C to constant weight.

[0038] Table 1. Synthesis and phenomena of different SUPRADES

[0039] abbreviation HBD HBA Phenomenon β-LA β-cyclodextrin L-lactic acid Transparent viscous liquid β-LeA β-cyclodextrin Levulinic acid White precipitation β-GL β-cyclodextrin glycerin White precipitation HP-LA Hydroxypropyl-β-CD L-lactic acid Transparent viscous liquid HP-LeA Hydroxypropyl-β-CD Levulinic acid Transparent viscous liquid HP-GL Hydroxypropyl-β-CD glycerin Transparent viscous liquid γ-LA γ-cyclodextrin L-lactic acid Transparent viscous liquid γ-LeA γ-cyclodextrin Levulinic acid White precipitation γ-GL γ-cyclodextrin glycerin Transparent viscous liquid

[0040] 2 Study on the extraction of tea polyphenols by SUPRADES

[0041] 2.1 Extraction methods of tea polyphenols

[0042] Take a white tea cake and grind it into powder using a high-speed grinder. Weigh 0.2 g of tea powder accurately and add SUPRADES extraction solvent. After ultrasonic treatment for a certain period of time, centrifuge at 4000 rpm for 10 minutes. Collect the supernatant to obtain the tea polyphenol extract.

[0043] The tea leaves can also be derived from raw materials containing tea polyphenols such as green tea, black tea, oolong tea, white tea, and dark tea;

[0044] 2.2 Quantification method of tea polyphenols

[0045] The Folin-phenol method was used with slight modifications: 5.00 mg of gallic acid standard was accurately weighed and diluted to a 0.1 mg / mL gallic acid standard solution in a 50 mL volumetric flask. 0, 0.5, 1, 2, 3, and 4 mL of the gallic acid standard solution and 100 μL of the tea polyphenol extract were added to a 10 mL EP tube. The volume was made up to 5 mL with distilled water. 1 mL of 50% Folin-phenol was added and the mixture was reacted for 3 minutes. Then, 4 mL of 3% sodium carbonate was added and the mixture was reacted for 30 minutes. After the reaction, 100 μL of each tube was transferred to a 96-well plate in triplicate and the absorbance was measured at 760 nm. A standard curve was constructed with gallic acid concentration (μg / mL) as the abscissa and absorbance (A) as the ordinate. The regression equation was Y = 0.0188x + 0.0394, with an R² = 0.9981, indicating good linearity for gallic acid in the range of 5 to 40 μg / mL. The tea polyphenols concentration was calculated according to the standard curve, and the tea polyphenols yield was calculated according to the following formula.

[0046] (1)

[0047] Where: C is the polyphenol mass concentration calculated by the regression equation, μg / mL; m is the sample mass, g; V is the total volume of the extraction solvent, mL; 100 is the dilution factor.

[0048] 2.3 Optimization of extraction conditions

[0049] 2.3.1 Effects of SUPRADES Type and HBA / HBD Ratio on Tea Polyphenols Extraction Yield

[0050] Under the conditions of ultrasonic time of 60 min, DESP water content of 40%, liquid-to-solid ratio of 10 g / mL, pure water and 60% ethanol were used as controls, and different SUPRADES were used to extract polyphenols from tea. The results are shown in Figure 2. Figure 2 (A). The results showed that when HP-LA was used as the extraction solvent, the content of tea polyphenols in the extract was the highest, so HP-LA was selected as the optimal extraction solvent.

[0051] The effects of different mass ratios of HP-β-CD and L-LA on the extraction rate of tea polyphenols in the HP-LA system were further investigated. Figure 2 (B) When the mass ratio of HP-β-CD to L-LA was 1:5, the extraction rate of tea polyphenols was the highest. Therefore, HP-LA with a mass ratio of 1:5 was selected as the tea polyphenol extraction solvent for subsequent experiments.

[0052] 2.3.2 Effect of HP-LA water content on tea polyphenols extraction rate

[0053] The effects of different water contents of HP-LA (85%, 70%, 55%, 40%, and 25%) on the extraction efficiency of tea polyphenols were investigated under the conditions of HP-LA (1:5) as the extraction solvent, a liquid-to-solid ratio of 10 g / mL, and an ultrasonic time of 60 min.

[0054] like Figure 3 As shown, when the water content of HP-LA was 55%, the extraction yield reached its highest level, reaching (72.47 ± 2.13) mg / g. When the water content was reduced to 25%, the polyphenol yield rapidly declined. Excessively high volume fractions increase viscosity, making it difficult for polyphenols to diffuse into the extract and hindering mass transfer between polyphenols and the extract. Therefore, this study selected water contents of 70%, 55%, and 40% for subsequent experimental analysis.

[0055] 2.3.3 Effect of liquid-to-solid ratio on tea polyphenols extraction rate

[0056] The effects of different solid-liquid ratios (1:10, 1:40, 1:70, 1:100, 1:130 g / mL) on the extraction efficiency of tea polyphenols were investigated under the conditions of HP-LA (1:5) as the extraction solvent, HP-LA water content of 40%, and ultrasonic time of 60 min.

[0057] like Figure 4 As shown, with increasing liquid-to-liquid ratio, polyphenol extraction initially increased significantly, then slowly declined. At a liquid-to-liquid ratio of 40 g / mL, the polyphenol extraction rate reached its highest value, (98.36 ± 2.32) mg / g. However, after increasing the liquid-to-liquid ratio to a certain level, polyphenol extraction reached saturation. Further increases in the liquid-to-liquid ratio may increase the dissolution of impurities, leading to a decrease in extraction yield and waste of raw materials. Therefore, in this study, liquid-to-liquid ratios of 10, 40, and 70 g / mL were selected for subsequent optimization experiments.

[0058] 2.5.3 Effect of ultrasonic time on tea polyphenols extraction rate

[0059] The effects of different ultrasonic times (15, 30, 45, 60, and 75 min) on the extraction efficiency of tea polyphenols were studied under the conditions of HP-LA (1:5) as the extraction solvent, a liquid-to-solid ratio of 10 g / mL, and a water content of 40% in HP-LA.

[0060] like Figure 5As shown, increasing ultrasonication time increases the energy generated, leading to more complete cell wall disruption, facilitating the release and dissolution of polyphenols, and increasing polyphenol yield. The highest polyphenol extraction yield, (71.39 ± 1.41) mg / g, was achieved at 45 minutes. However, after 45 minutes, the extracted polyphenols were oxidized or even decomposed due to exposure to factors such as light and heat, thus reducing the extraction yield. Furthermore, prolonged ultrasonication time increases energy consumption, leading to increased extraction costs. Therefore, 30, 45, and 60 minutes were selected for subsequent experiments.

[0061] 2.5.4 Optimization of response surface extraction conditions

[0062] 2.5.4.1 Statistical Analysis and Model Fitting

[0063] Based on the single-factor experiment, the Box-Behnken experimental design was used to study the effects of volume fraction 45%, liquid-to-solid ratio 40 (g / mL), and ultrasonic time 45 min on the polyphenol extraction rate. The factors and levels are shown in Table 2.

[0064] Table 2. Response surface factor level design

[0065]

[0066] The response surface design and results are shown in the table. Response surface optimization analysis revealed the following regression equation for the polyphenol extraction yield (Y) and HP-LA water content (A), liquid-to-solid ratio (B), and ultrasonication time (C): Y = 107.056-1.787571015A + 18.39347199B + 5.255571272C + 0.515142029AB + 1.87AC + 4.063857456BC - 4.016885979A² + 12.15897199B² - ​​5.739114021C². As shown in Table 3, the model was highly significant (P < 0.0001), and the lack-of-fit term was not significant ( P =0.7967). Statistical analysis of the significant factors showed that the order of significance was liquid-to-solid ratio (B) > ultrasonic time (C) > HP-LA concentration (A), A 2 、C 2 , BC had a significant effect on the extraction rate of white tea polyphenols (P<0.05), and B2 had an extremely significant effect on its polyphenol extraction rate (P<0.01). 2 =0.9790, indicating that the model can predict the test results. Correction coefficient R 2 adj=0.9520, and the coefficient of variation is 3.59%, indicating that the model is feasible. In summary, the model fitted by the experiment has a good prediction effect.

[0067] Table 3. Response surface analysis scheme and experimental results

[0068]

[0069] Table 4. Model variance analysis results

[0070]

[0071] 2.5.4.2 Process validation test

[0072] The optimal extraction process for polyphenols was determined through optimization: an HP-LA water content of 40%, a liquid-to-solid ratio of 66.378 mL / g, and an ultrasonication time of 54.083 min. Under these conditions, the predicted polyphenol extraction yield was 110.59 mg / g. In a validation experiment, the operating parameters were adjusted to a 40% HP-LA water content, a liquid-to-solid ratio of 66 g / mL, and an ultrasonication time of 54 min, taking into account actual conditions. Three parallel experiments were conducted, resulting in a polyphenol yield of 111.36 ± 2.31 mg / g. This result is close to the predicted theoretical value, indicating that the model fits well and the optimized conditions are reliable. The model can be used to predict the extraction of tea polyphenols.

[0073] The optimal preparation process of the present invention is:

[0074] 1. Weigh hydroxypropyl-β-cyclodextrin and L-lactic acid in a 1:5 mass ratio, add an appropriate amount of water, and stir at 80°C for 30 minutes. Then, vacuum dry at 60°C to constant weight to obtain pure HP-LA. Add water to a water content of 40% to obtain the extraction solvent.

[0075] 2. Weigh 0.2 g of tea powder accurately and add 13.2 mL of the extraction solvent prepared in the first step. After ultrasonic treatment for 54 minutes, centrifuge at 4000 rpm for 10 minutes. Collect the supernatant to obtain the tea polyphenol extract. Determine the tea polyphenol content according to the polyphenol quantification method. The tea polyphenol content in the extract is 1.72 ± 0.05 mg / mL.

[0076] Experimental Example 2 Preparation of Tea Polyphenols Hydrogel Biofilm Based on HP-LA

[0077] 1. Biofilm preparation method

[0078] The membrane solution was prepared as described in the literature with slight modifications: 0.3 g of chitosan (CS) and 1.5 g of polyvinyl alcohol (PVA) were weighed into a beaker, an appropriate amount of water was added, and the mixture was sealed with plastic wrap. Heat and stir at 70°C until the PVA was completely dissolved. After cooling, HP-LA or tea polyphenol extract with a 40% water content was added to 20 mL. Stir thoroughly at room temperature and ultrasonically degas to obtain a uniform membrane solution. Films were cast by transferring 1 g of the uniform membrane solution into a mold, drying in a 60°C oven to set the desired shape, and then gently removing the film with tweezers.

[0079] 2 Film formation time investigation

[0080] Because polyphenols are easily oxidized at high temperatures, their content in the film decreases. Therefore, it was necessary to investigate the drying time required for biofilm formation. We attempted to remove the film and weigh it after 1, 2, 3, 4, 5, and 6 hours. The results are shown in Table 6. The results showed that after 2 hours of drying at 60°C, the biofilm was essentially formed, but still contained a significant amount of moisture. 3 hours was the most suitable drying time.

[0081] Table 6. Phenomena and weights of samples obtained at different film forming times (n=3)

[0082] Time (h) Phenomenon Membrane weight (mg) 1 Unable to form, still in liquid form / 2 Molding, easy to peel off <![CDATA[299.70±2.12 a ]]> 3 Molding, easy to peel off <![CDATA[268.00±2.67 b ]]> 4 Molding, easy to peel off <![CDATA[267.63±2.20 bc ]]> 5 Molding, easy to peel off <![CDATA[265.70±1.22 bd ]]> 6 Molding, easy to peel off <![CDATA[262.03±2.75 c ]]>

[0083] Note: Different letters indicate significant differences ( P <0.05)

[0084] The beneficial effects of the present invention are demonstrated below through specific effect tests.

[0085] Test Example 1: Determination of Antioxidant Capacity of Tea Polyphenols Extract

[0086] After extracting tea polyphenols according to the optimized extraction process described in "2.6.2," biochemical kits were used to determine the total antioxidant capacity and DPPH radical scavenging capacity of the polyphenol extracts. The effects of a traditional solvent (60% ethanol) and the HP-LA system on the antioxidant capacity of tea polyphenols at the same concentration were compared. The experimental results are shown in Table 5. These results demonstrate that the use of HP-LA's supramolecular DES as an extraction solvent does not impair the antioxidant activity of tea polyphenols.

[0087] Table 5. Effects of HP-LA and ethanol as extraction solvents on the antioxidant capacity of the extracts

[0088]

[0089] Note: Different letters indicate significant differences ( P <0.05)

[0090] Experimental Example 2 Study on the Antioxidant Activity of Biofilm

[0091] Following the biofilm preparation method in "3.1," CS and PVA were weighed and dissolved in 10, 12.5, and 15 mL of distilled water, respectively, with heating and stirring. After cooling, 10, 7.5, and 5 mL of tea polyphenol extract were added to obtain membrane solutions with varying tea polyphenol content. After ultrasonic degassing, the membrane solution was poured into a mold and dried in a forced-air drying oven at 60°C for 3 hours to obtain a thin film. 0.1 g of the film was re-dissolved in 1 mL of water and ultrasonically allowed to rest for 24 hours. The antioxidant activity of the membrane was then determined using a biochemical assay kit. The results are shown in Table 7.

[0092] The experimental results showed that the prepared tea polyphenols biofilm had certain antioxidant activity.

[0093] Table 7. Antioxidant activity of films with different tea polyphenol contents (n=3)

[0094]

[0095] Note: Different letters indicate significant differences (P < 0.05)

Claims

1. A method for preparing a tea polyphenol extract, characterized in that: It includes the following steps: a. Preparation of supramolecular deep eutectic solvent: Weigh hydrogen bond acceptor and hydrogen bond donor according to mass ratio, mix, add water, stir at 80°C, and vacuum dry at 60°C to obtain; b. Take tea powder, add the supramolecular deep eutectic solvent prepared in step a, and perform ultrasonic extraction; c. Centrifuge and take the supernatant to obtain the tea polyphenols extract; The hydrogen bond donor HBD in the supramolecular deep eutectic solvent is hydroxypropyl-β-CD; the hydrogen bond acceptor HBA is L-lactic acid; and the weight ratio thereof is: Hydroxypropyl-β-CD: L-lactic acid = 1:5; The ultrasonic extraction conditions are as follows: ultrasonic time 54 min; water content in the supramolecular deep eutectic solvent is 40%; liquid-to-solid ratio of tea powder to supramolecular deep eutectic solvent extraction solvent is 1:66 g / mL; The centrifugal conditions are: 4000 r / min for 10 min.

2. Use of the tea polyphenol extract obtained by the preparation method of the tea polyphenol extract according to claim 1 in the preparation of medicines or health products with antioxidant effects.

3. A tea polyphenol hydrogel biofilm, characterized by: The tea polyphenol extract is prepared by adding the tea polyphenol extract obtained by the preparation method of the tea polyphenol extract according to claim 1 and matrix excipients acceptable to film preparations.

4. The tea polyphenol hydrogel biofilm according to claim 3, characterized in that: The matrix excipients include: chitosan, polyvinyl alcohol, gelatin, carboxymethyl cellulose sodium CMC-Na, methyl cellulose MC, hydroxypropyl methyl cellulose HPMC, glutaraldehyde, formaldehyde, glycerol, propylene glycol, sodium dihydrogen phosphate, ethyl hydroxybenzoate, phenoxyethanol, and carbomer.

5. The tea polyphenol hydrogel biofilm according to claim 4, characterized in that: The matrix auxiliary materials are chitosan and polyvinyl alcohol.

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