A kind of balsam pear extract and its preparation method, use, and quality detection method

Abstract

The present invention provides a leek extract, which is prepared from fresh leek using enzyme-assisted extraction technology, macroporous adsorption resin purification, and drying. The extract contains chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C in an amount of not less than 30% w / w, and a mass fraction of total phenolic acids of not less than 55% w / w. The present invention also provides a preparation method and use of the leek extract. The leek extract of the present invention has a high content of polyphenols and good antioxidant activity, providing a theoretical basis for the development and utilization of leek.

Description

Technical Field

[0001] The invention relates to a balsam pear extract and a preparation method, application and quality detection method thereof. Background Art

[0002] The scientific name of Acanthopanax trifoliatus is white taro (Acanthopanax trifoliatus (Linn.) Merr.), which is also known as "goose palm tendon" or "grass palm taro" in Guangdong, "three-leaf taro" in Hunan and Zhejiang, and "three-leaf taro" in Guangxi and Sichuan. It is a climbing shrub of the genus Acanthopanax of the Araliaceae family, distributed in a large area of ​​central and southern my country (Zhang Kun, Cheng Shupeng, Wu Wenjing, et al. Research progress on the chemical composition, biological activity and safety of taro [J]. Strait Pharmacy, 2017, 29(04): 1-5.). The roots (bark) and leaves of taro are commonly used Chinese herbal medicines. Based on their daily experience, people in some areas often boil the roots and stems in water and use them for bathing to treat common skin diseases such as eczema and prickly heat, with particularly significant effects. The Ming Dynasty's "Food Materia Medica" records that "the leaves of Acanthopanax elegans can be eaten as vegetables to treat skin rheumatism." It is good at dispelling wind and dampness, relaxing muscles and activating blood circulation, reducing swelling and detoxifying, and is often used to treat colds, coughs, rheumatism, sciatica and other diseases (Chen Lanqing, Li Shuzhen, Gan Lishe, et al. Analysis of chemical components of Acanthopanax elegans based on ultra-high performance liquid chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry [J]. Subtropical Plant Science, 2023, 52(04): 301-309.). Modern research shows that the rich polyphenols contained in Acanthopanax elegans are its main active ingredients, such as chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid B, isochlorogenic acid A, isochlorogenic acid C and other ingredients. These ingredients have shown pharmacological activities in anti-inflammatory, antibacterial, antiviral, immunomodulatory and antioxidant aspects.

[0003] The herb is grown in abundance in Enping, Guangdong. For hundreds of years, local residents have had the custom of using it as both medicine and food. Processed products made from herb have become popular in the market. How to extract the effective substances from herb quickly and effectively and maximize the effects of herb has become a hot issue in the development of herb products. The reports on the extraction methods of effective substances from herb in the literature mainly include alcohol extraction (Lao Jinghui, Pan Chaomei, Yu Qin, et al. Study on the inhibitory effect of white herb extract on Propionibacterium acnes and whitening activity [J]. Modern Chinese Medicine, 2016, 18(09): 1120-1124.), supercritical carbon dioxide extraction (Yu Jiani, Feng Caixia, Liu Xiangqian, et al. Protective effect of total polyphenols from white herb leaves on oxidative damage and senescence of PC12 cells induced by Aβ25-35 and AAPH [J]. Journal of Zhejiang Sci-Tech University). (Natural Science), 2023, 49(03): 353-358.), ultrasonic extraction (Huang Junsheng. Study on the preparation of Chaozhou cuisine seasonings by supercritical carbon dioxide extraction of flavonoids from Bletilla striata[J]. Chinese Condiments, 2017, 42(05): 57-60.) and microwave extraction (Gao Xia, Li Yunxiang, Cai Lingyun. Study on the extraction process and content determination of total saponins from Bletilla striata leaves[J]. Spectral Laboratory, 2009, 26(04): 814-821.) and other methods. For example, the preparation method of taro extract reported in "Comparison of Total Polyphenol Content and Antioxidant Activity of Different Varieties of Taro" is: "Collect fresh young branches and leaves of different varieties of taro produced in Enping, dry them at room temperature and then crush them, take out 100g of each, add 75% ethanol by volume for cold soaking extraction, filter every 1 day, extract 3 times in total, combine the extracts, and concentrate them on a rotary evaporator to obtain extracts of different varieties of taro." This method takes a long time and the total polyphenol content of the extract is low, ranging from 82.3 to 112.3mg. GAE / g extract; the preparation method reported in "Process Optimization of Purification of Total Polyphenols from Scutellaria baicalensis Leaves with Macroporous Adsorption Resin" states: "Weigh 1 kg of the extract into a conical flask, add 3 times the volume of 95% ethanol to the powdered Scutellaria baicalensis leaf, and ultrasonically extract. The extract is filtered and concentrated under reduced pressure to obtain a paste. Repeat the extraction 3 to 4 times, combine the concentrated extracts, dissolve in an appropriate amount of 45°C distilled water, add 3 times the volume of petroleum ether, and repeat the extraction 3 to 4 times. The resulting aqueous phases are combined, evaporated, and freeze-dried to obtain a crude extract of total polyphenols from Scutellaria baicalensis leaves. Weigh 3 g of the crude extract of total polyphenols from Scutellaria baicalensis leaves, ultrasonically dissolve it, and dilute it to a volume in a 500 mL volumetric flask to prepare a total polyphenol loading solution with a mass concentration of 6 mg / mL." HPD100 resin is then used for purification, which is a complex process. Furthermore, due to the complex composition of polyphenols, different extraction and purification processes will affect the activity of the final extract. Summary of the Invention

[0004] The invention provides a balsam pear extract and a preparation method, application and quality detection method thereof.

[0005] The invention provides a leek extract, which uses fresh leek as a raw material, adopts enzyme-assisted extraction technology, macroporous adsorption resin purification and drying to obtain the leek extract; the extract contains chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C in an amount of not less than 30% w / w, and the mass fraction of total phenolic acids is not less than 55% w / w.

[0006] The extract contains 12.0% to 16.0% w / w of chlorogenic acid, 0.6% to 0.9% w / w of cryptochlorogenic acid, 2.5% to 4.0% w / w of rutin, 8.0% to 12.0% w / w of isochlorogenic acid A, 0.8% to 1.5% w / w of isochlorogenic acid, and 1.5% to 2.0% w / w of isochlorogenic acid C.

[0007] Wherein, the enzyme is cellulase; the model of the macroporous resin is HPD-450.

[0008] The present invention also provides a method for preparing the taro extract, which comprises the following steps:

[0009] a. Rinse the freshly harvested taro with clean water, dry it in an oven at 50°C, then grind it and pass it through a 60-mesh sieve to obtain taro powder;

[0010] b. Weigh fine powder of araucaria japonica, add 35-55 times the amount of distilled water, adjust the pH to 4.5-5.5 with 1 mol / L hydrochloric acid, then add 0.4-0.8% cellulase or pectinase, mix thoroughly, and perform enzymolysis in a 50°C water bath for 60-120 minutes. Finally, inactivate in a 95°C water bath for 10 minutes, and filter to obtain an araucaria japonica extract; and dry the extract to obtain a crude araucaria japonica extract.

[0011] b. Measure 450 mL of the extract, adjust the pH to 4.0 with 1 mol / L hydrochloric acid, pass the extract through a chromatography column containing 45 mL of HPD-450 macroporous resin at a flow rate of 90 mL / h, and then elute with 180 mL of 60% ethanol; collect the ethanol elution fraction, add anhydrous ethanol to adjust the ethanol concentration to 75%, place in a refrigerator at 4°C for refrigeration, filter after 16 hours, recover the ethanol under reduced pressure until there is no alcohol taste, and dry to obtain the taro extract.

[0012] Further preferably, the pH in step b is adjusted to 5.0; and the enzyme is 0.6% cellulase.

[0013] The present invention provides use of the balsam pear extract in preparing health-care food with anti-oxidation effect.

[0014] The present invention provides a method for detecting the quality of the leek extract, which uses HPLC to determine the index components chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C in the leek extract. The chromatographic conditions are:

[0015] Japan Shimadzu Shim-pack GTS chromatographic column (4.6×250mm (HSS), 5μm C18); mobile phase: A is 0.2% phosphoric acid aqueous solution, B is acetonitrile; gradient elution program: 0-20 min, 10% B; 20-45 min, 10%-20% B; 45-70 min, 20% B; 70-80 min, 20%-10% B; column temperature: 30°C; flow rate: 1 mL / min; the mixed reference solution and the test solution were filtered through a 0.22μm microporous filter membrane and injected into the chromatograph for analysis, with an injection volume of 5μL each; the detection wavelength for CA, 4DA, IAB, IAA, and IAC was 325 nm, and the detection wavelength for Rut was 254 nm.

[0016] Furthermore, it comprises the following steps:

[0017] a. Prepare mixed reference solution:

[0018] Preparation of reference substance stock solutions: Accurately weigh appropriate amounts of CA, 4DA, Rut, IAB, IAA, and IAC reference substances, dissolve them in 60% ethanol, transfer to a 10 mL volumetric flask, and dilute to volume with 60% ethanol to prepare reference substance stock solutions with a concentration of 1 mg / mL for each substance.

[0019] Preparation of mixed reference substance stock solution: Accurately pipette the above reference substance stock solution into a 10mL volumetric flask, adding 3mL of CA, 0.3mL of 4DA, 0.9mL of Rut, 0.5mL of IAB, 4mL of IAA, and 0.6mL of IAC, respectively. Dilute to volume with 60% ethanol and shake well.

[0020] Preparation of mixed reference solution: Accurately pipette 0.5 mL of mixed reference stock solution into a 2 mL volumetric flask and dilute to the mark with 60% ethanol.

[0021] b. Preparation of test solution:

[0022] Weigh 12 mg of taro extract accurately, add 60% ethanol and ultrasonically dissolve it, transfer it quantitatively to a 25 mL volumetric flask, dilute it to the scale with 60% ethanol, shake well, and obtain it.

[0023] The present invention prepares a leek extract by treating leek with cellulase and purifying it with a macroporous adsorption resin. In order to study the content of active ingredients in the leek extract and evaluate the in vitro antioxidant activity of the leek extract, the present invention uses high performance liquid chromatography to determine polyphenols such as chlorogenic acid (CA), cryptochlorogenic acid (4DA), rutin (Rut), isochlorogenic acid A (IAA), isochlorogenic acid B (IAB), and isochlorogenic acid C (IAC) in the leek extract, and evaluates the DPPH and ABTS activity of the leek extract. + The results showed that the content of the six components in the extract of leucanthemum villosum was 31.76%, among which chlorogenic acid, isochlorogenic acid A and rutin had the highest content; DPPH and ABTS in the extract of leucanthemum villosum were the highest. + Free radical scavenging ability IC 50 The values ​​were 13.91μg / mL and 26.22μg / mL respectively. The polyphenol content in the balsam pear extract is high and has good antioxidant activity. The invention provides a theoretical basis for the development and utilization of balsam pear. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 HPLC chromatograms of the test sample (a) and mixed reference sample (b) of the lycopodiella extract (wherein, 1. chlorogenic acid; 2. isochlorogenic acid; 3. rutin; 4. isochlorogenic acid B; 5. isochlorogenic acid A; 6. isochlorogenic acid C);

[0025] Figure 2 DPPH radical scavenging ability of balsam pear extract and L-ascorbic acid;

[0026] Figure 3 ABTS+ free radical scavenging capacity of balsam pear extract and L-ascorbic acid. DETAILED DESCRIPTION

[0027] 1. Materials

[0028] 1.1 Materials and Reagents

[0029] Acanthopanax trifoliatus, originating from Enping City, Jiangmen City, Guangdong Province, has been identified by Associate Professor Wu Weihong of the Department of Traditional Chinese Medicine of Jiangmen Vocational College of Traditional Chinese Medicine as the stems and leaves of Acanthopanax trifoliatus (Linn.) Merr., a plant of the Araliaceae family. C, IAC, all 98% pure, Shanghai Shifeng Biotechnology Co., Ltd.; anhydrous ethanol of analytical grade, Taishan Yueqiao Reagent Plastic Co., Ltd.; hydrochloric acid and phosphoric acid of analytical grade, Guangzhou Chemical Reagent Factory; HPD-450 macroporous resin, Yichenghua Glass Instrument Co., Ltd., Pengjiang District, Jiangmen City; 0.22 μm microporous filter membrane, Jinlong Company; acetonitrile of chromatographic grade, MREDA, Germany; distilled water, Guangzhou Watsons Food and Beverage Co., Ltd.; 2,2-azino-bis(3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), Shanghai MacLean Biochemical Technology Co., Ltd.; cellulase, enzyme activity 100,000 U / g, Shandong Longkote Enzyme Preparation Co., Ltd.; L-ascorbic acid, Xilong Scientific Co., Ltd.

[0030] 1.2 Instruments and Equipment

[0031] SECURA125-1CN electronic balance, Sartorius Scientific Instruments (Beijing) Co., Ltd.

[0032] NEXERA XR high-performance liquid chromatograph, diode array detector, and UV-2600i ultraviolet-visible spectrophotometer were all from Shimadzu Corporation, Japan; HH-600 digital electric constant-temperature water bath was provided by Changzhou Aohua Instrument Co., Ltd.; KQ-500DE ultrasonic cleaner was provided by Kunshan Ultrasonic Instrument Co., Ltd.; RV10auto rotary evaporator was provided by Guangzhou Yike Laboratory Technology Co., Ltd.; and BCD-521WKM(E) refrigerator was provided by Midea Group Co., Ltd.

[0033] Example 1 Preparation of Lablab oleifera extract

[0034] Freshly harvested taro leaf is rinsed with clean water, dried in a 50°C oven, then pulverized and passed through a 60-mesh sieve to obtain taro leaf powder. A certain amount of taro leaf powder is weighed, added to 45 times the volume of distilled water, and the pH is adjusted to 5.0 with 1 mol / L hydrochloric acid. Then, 0.6% cellulase is added and mixed thoroughly. The mixture is enzymatically hydrolyzed in a 50°C waterbath for 60 minutes, and finally inactivated in a 95°C waterbath for 10 minutes. Filter the mixture to obtain the taro leaf extract. Dry the extract to obtain the crude taro leaf extract.

[0035] 450mL of the extract was measured, the pH was adjusted to 4.0 with 1mol / L hydrochloric acid, and the extract was passed through a chromatography column equipped with 45mL of HPD-450 macroporous resin at a flow rate of 90mL / h. The extract was then eluted with 60% ethanol in an amount of 180mL. The ethanol elution fraction was collected, anhydrous ethanol was added to adjust the ethanol concentration to 75%, the extract was placed in a 4°C refrigerator for refrigeration, and filtered after 16h. The ethanol was recovered under reduced pressure until there was no alcohol taste, and the extract was dried to obtain the taro extract. Three batches of taro extract were prepared according to this process and were labeled as No. 202405, No. 202406, and No. 202407.

[0036] Example 2 Parameter screening test of the taro extract of the present invention

[0037] 1. Instruments

[0038] UV-visible spectrophotometer, analytical balance, low-speed centrifuge, constant temperature water bath, grinder, pH meter, 10 mL brown volumetric flask, 25 mL stoppered Erlenmeyer flask, 200 mL brown volumetric flask, 50 mL beaker.

[0039] 2. Medicines

[0040] Gallic acid standard 100 mg, anhydrous sodium carbonate 500 g, Folin-phenol reagent 100 mL, macroporous resin, 0.22 μm microporous filter membrane, distilled water. Cellulase, enzyme activity 100,000 U / g, pectinase, cellulase.

[0041] 3. Experimental steps

[0042] 3.1 Gallic acid content determination method

[0043] 3.1.1 Standard curve drawing

[0044] Accurately weigh 22.3 mg of gallic acid standard, dissolve it in water and dilute it to a 200 mL volumetric flask to obtain a 0.1115 mg / mL standard stock solution. Accurately pipette 0.00, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 mL of gallic acid reference solution into 10 mL brown volumetric flasks, add water to 2 mL each, add 0.5 mL of forlin phenol reagent, shake well, let it stand for 2 minutes, add 1.5 mL of 20% sodium carbonate solution, add water to the scale, shake well, place it in a 75°C water bath in the dark for 10 minutes, take it out, quickly cool it to room temperature, use the corresponding blank solvent as a blank, measure the absorbance (A) at a wavelength of 765 nm, use the A value as the ordinate and the mass concentration of the gallic acid reference solution as the abscissa, draw a standard curve, and the regression equation is: Y = 0.1001X + 0.0232, R 2 =0.9992.

[0045] 3.1.2 Extraction of total phenols from samples

[0046] Freshly harvested araucaria leaf is rinsed with clean water, dried in an oven at 55°C, then pulverized and passed through a 60-mesh sieve to obtain araucaria leaf powder. Accurately weigh 1.00 g of araucaria leaf powder and place it in a 50 mL stoppered conical flask. Add distilled water according to the material-liquid ratio, adjust the pH with 0.5 mol / L hydrochloric acid solution or 1 mol / L NaOH solution, add a certain amount of enzyme, perform enzymatic hydrolysis at a certain temperature, and heat at 95°C for 10 minutes to inactivate the enzyme. The resulting extract is centrifuged at 3000 rpm for 5 minutes, and the supernatant is collected for determination of total polyphenol content. The total phenolic acid extraction rate (%) of araucaria leaf is calculated as CV / (m × 1000) × 100, where: C is the total phenolic acid concentration in the extract (mg / mL); V is the volume of the extract (mL); and m is the mass of the araucaria leaf sample (g).

[0047] 3.1.3 Determination of total phenol content in samples

[0048] Pipette 0.05mL of total polyphenol extract, add water to 2mL, add 0.5mL of Folin-phenol reagent respectively, shake well and let it stand for 2 minutes, add 1.5mL of 20% sodium carbonate solution, add water to the scale, shake well, place in a 75℃ water bath in the dark for 10 minutes, take out, quickly cool to room temperature, use the corresponding blank solvent as a blank, measure the absorbance (A) at a wavelength of 765nm, and calculate the total polyphenol content in the extract according to the working curve.

[0049] 3.2 Single-factor experiment

[0050] 3.2.1 Effect of single enzyme on the extraction rate of total phenolic acids from basil

[0051] Weigh 1.0g of arachis japonica powder and add 0.6% (mass fraction, the same below) of protease, cellulase, and pectinase, respectively, at a solid-liquid ratio of 1:35 (g / mL) and pH 5. Enzymatic hydrolysis was performed at 50°C for 90 minutes, and the extraction yields were calculated. As shown in Table 1, cellulase and protease showed the best results, followed by pectinase, while protease had little effect. (Extraction yield = total phenolic acids mass / arachis japonica mass * 100%, with gallic acid as the standard substance)

[0052] Table 1 Effects of different enzymes on the extraction rate of total phenolic acids from basil

[0053] Types of enzymes Extraction rate (%) Protease 4.26 Cellulase 5.59 Pectinase 4.83 No enzyme added 4.22

[0054] 3.2.2 Effect of cellulase dosage on the extraction rate of total phenolic acids from basil

[0055] 1.0 g of araucaria japonica powder was weighed and, at a solid-liquid ratio of 1:35 (g / mL) and pH 5, cellulase was added at concentrations of 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% (mass fraction), respectively. Enzymatic hydrolysis was performed at 50°C for 90 min, and the extraction yields were calculated. As shown in Table 2, the highest extraction yield of total phenolic acids from araucaria japonica was achieved when the cellulase dosage was 0.6%.

[0056] Table 2 Effect of cellulase dosage on the extraction rate of total phenolic acids from basil

[0057] Amount of cellulase (%) Extraction rate (%) 0.2 4.42 0.4 4.75 0.6 5.53 0.8 4.84 1.0 4.53

[0058] 3.2.3 Effect of pH on the extraction rate of total phenolic acids from basil

[0059] Weigh 1.0 g of araucaria japonica powder at a solid-liquid ratio of 1:35 (g / mL). Adjust the pH to 4, 4.5, 5.0, 5.5, and 6.0, respectively. Add 0.6% cellulase, and enzymatically hydrolyze at 50°C for 90 min. The extraction yield was calculated. As shown in Table 3, the highest extraction yield of total phenolic acids from araucaria japonica was achieved at a pH of 5.0.

[0060] Table 3 Effect of pH on the extraction rate of total phenolic acids from basil

[0061] pH Extraction rate (%) 4 4.23 4.5 5.06 5.0 5.58 5.5 4.94 6.0 4.69

[0062] 3.2.4 Effect of enzymatic hydrolysis time on the extraction rate of total phenolic acids from basil

[0063] 1.0 g of araucaria japonica powder was weighed and, at a solid-liquid ratio of 1:35 (g / mL) and pH 5, 0.6% (mass fraction) of cellulase was added. Enzymatic hydrolysis was performed at 50°C for 30, 60, 90, 120, and 150 min, and the extraction yield was calculated. As shown in Table 4, the highest extraction yield of total phenolic acids from araucaria japonica was achieved when the hydrolysis time was 60 min.

[0064] Table 4 Effect of enzymatic hydrolysis time on the extraction rate of total phenolic acids from taro

[0065] Enzymatic hydrolysis time (min) Extraction rate (%) 30 3.42 60 5.67 90 5.56 120 5.24 150 4.83

[0066] 3.2.5 Effect of material-liquid ratio on the extraction rate of total phenolic acids from basil

[0067] 1.0 g of araucaria powder was weighed and 0.6% (mass fraction) of cellulase was added at a solid-liquid ratio of 1:15, 1:25, 1:35, 1:45, and 1:55 (g / mL) at pH 5. Enzymatic hydrolysis was performed at 50°C for 60 min, and the extraction yield was calculated. As shown in Table 5, the highest extraction yield of total phenolic acids from araucaria was achieved when the solid-liquid ratio was 1:45 (g / mL).

[0068] Table 5 Effect of solid-liquid ratio on the extraction rate of total phenolic acids from basil

[0069] Solid-liquid ratio (g / mL) Extraction rate (%) 1：15 4.02 1：25 4.85 1：35 5.48 1：45 5.68 1：55 5.15

[0070] 3.3 Optimization and verification experiments of extraction process

[0071] Based on the results of single-factor experiments, the optimal extraction process was determined as follows: freshly harvested taro leaf was rinsed with clean water, dried in an oven at 50°C, then pulverized and passed through a 60-mesh sieve to obtain taro leaf powder. A certain mass of taro leaf powder was weighed, added with 45 times the volume of distilled water, and the pH was adjusted to 5.0. 0.6% cellulase was then added and thoroughly mixed. The mixture was enzymatically hydrolyzed in a 50°C waterbath for 60 minutes, and finally inactivated in a 95°C waterbath for 10 minutes. The extract was then centrifuged to obtain the taro leaf extract. Three parallel experiments were conducted, yielding extraction yields of 5.77%, 5.82%, and 5.65%, respectively.

[0072] Characteristics of the extraction method: the solvent is water, the extraction rate is high, the extraction time is short, and the conditions are mild.

[0073] 4. Macroporous adsorption resin purification process

[0074] 4.1 Static adsorption test and desorption test

[0075] (1) Preparation of crude extract

[0076] Freshly harvested taro leaf should be rinsed with clean water, dried in a 50°C oven, then pulverized and passed through a 60-mesh sieve to obtain taro leaf powder. Weigh a certain amount of taro leaf powder and add 45 times the amount of distilled water. Adjust the pH to 5.0 with 1 mol / L hydrochloric acid. Then add 0.6% cellulase and mix thoroughly. Hydrolyze in a 50°C waterbath for 60 minutes, then inactivate in a 95°C waterbath for 10 minutes. Filter to obtain the taro leaf extract. Measure 450 mL of the extract, adjust the pH to 4.0 with 1 mol / L hydrochloric acid, and set aside.

[0077] (1) Static adsorption: Weigh 1.0 g of each of the 13 pre-treated macroporous resins, place them in a 100 mL conical flask with a stopper, add 25 mL of the total polyphenol crude extract, and plug the flask. Place it in a constant temperature oscillator at 30°C and 100 r / min for full oscillation and adsorption for 24 hours, then filter to obtain the adsorbed solution. Add 25 mL of 70% ethanol to the resin from which the adsorption liquid has been filtered out, desorb it for 24 hours, and then filter to obtain the desorbed solution. Determine the A value according to the Folin-Ciocalteu method. Then, the total polyphenol content is obtained from the gallic acid standard equation, and according to the formula: adsorption amount = (CV-C1V1) / W, desorption rate = C2V2 /

[0078] The specific adsorption capacity and desorption rate of total polyphenols for each resin type were calculated using the formula (CV - C1V1) × 100%, where C and V are the concentration (mg / mL) and volume (mL) of the solution before adsorption, respectively; C1 and V1 are the concentration (mg / mL) and volume (mL) of the solution after adsorption, respectively; W is the mass of the resin (g); and C2 and V2 are the concentration (mg / mL) and volume (mL) of the solution after desorption, respectively. As shown in Table 6, the HPD-450 macroporous resin exhibited the best specific adsorption capacity and desorption rate, making it the preferred choice for purification of total polyphenols from taro.

[0079] Table 6 Adsorption and desorption performance of different types of macroporous resins on total polyphenols of taro

[0080] Serial number Resin Model Resin polarity Specific adsorption capacity (mg / g) Desorption rate (%) 1 HPD-400 Intermediate 13.16 81.87 2 XAD-16N Weak polarity 13.62 84.14 3 HPD-BJQH Intermediate 12.14 82.51 4 DM301 Intermediate 12.01 86.90 5 HPD-826 polarity 13.51 84.11 6 HPD-100 Non-hierarchical 11.36 83.11 7 LX-8 polarity 8.96 81.27 8 LSA-10 Weak polarity 15.44 77.91 9 HPD-300 Non-polar 12.59 79.24 10 NKA-II polarity 6.78 71.90 11 HP-20 Non-hierarchical 9.67 75.33 12 H103 Non-polar 12.14 86.68 13 HPD-450 Intermediate 16.11 90.02

[0081] 4.2 Single Factor Investigation

[0082] (1) Determination of sample loading amount

[0083] Take the pretreated macroporous resin column (diameter-to-height ratio of 1:9), take the crude extract of taro, adjust the pH to 4.0 with 1 mol / L hydrochloric acid, and -1 (column volume / hour) flow rate was used for dynamic adsorption, and the effluent was collected in sections. Every 2BV (column volume) was a portion. The total polyphenol content in each portion of the effluent was measured and the leakage was calculated. The results are shown in Table 7. It can be seen that when the sample volume reached 10BV, 8.27% of the total polyphenols in the taro leaf had leaked. After comprehensive consideration, the sample volume was determined to be 10BV. The leakage was calculated according to formula (2)

[0084] Calculate. Leakage rate / % = C1V1) / CV×100(2)

[0085] Where: C is the mass concentration of total polyphenols in the sample solution, mg / mL;

[0086] V——the volume of total polyphenols in the sample solution, mL;

[0087] C1——mass concentration of total polyphenols in the solution after adsorption, mg / mL;

[0088] V1——Volume of total polyphenols in the solution after adsorption, mL.

[0089] Table 7 Effect of sample volume on adsorption

[0090]

[0091] (2) Investigation of sample adsorption flow rate

[0092] A pretreated macroporous resin column (diameter-to-height ratio of 1:9) was loaded with 10 BV of the crude extract of taro. The pH was adjusted to 4.0 with 1 mol / L hydrochloric acid. The sample was loaded through the resin column at flow rates of 1 BV / h, 2 BV / h, 3 BV / h, 4 BV / h, and 5 BV / h, respectively. The effluent was collected, and the total polyphenol content in each effluent was determined. The adsorption rate was calculated and the optimal loading and adsorption flow rate was selected. The results are shown in Table 8. It can be seen that when the loading flow rate is too fast, the total phenolic acid adsorption is incomplete and the loss increases. Considering actual production, the preferred loading flow rate is 2 BV / h. The adsorption rate is calculated according to formula (1).

[0093] Adsorption rate / % = (CV - C1V1) / CV × 100 (1)

[0094] Where: C——mass concentration of total flavonoids in the sample solution, mg / mL;

[0095] V——the volume of total flavonoids in the sample solution, mL;

[0096] C1——mass concentration of total flavonoids in the solution after adsorption, mg / mL;

[0097] V1——Volume of total flavonoids in the solution after adsorption, mL.

[0098] Table 8 Effect of sample loading adsorption flow rate on adsorption

[0099]

[0100] (3) Investigation of eluents

[0101] A 10-bV volume of taro extract was measured, the pH adjusted to 4.0 with 1 mol / L hydrochloric acid, and passed through a glass column filled with macroporous resin (diameter-to-height ratio of 1:9) at a flow rate of 2 bV / h. Elution was then performed with 2 bV of distilled water and then 60% ethanol at a flow rate of 2 bV / h. The eluates were collected based on the ethanol concentration of the eluent used, and the concentration of total polyphenols in the eluates was determined. The results are shown in Table 9. As can be seen, total polyphenols were primarily concentrated in the 60% ethanol eluate, while water had a weaker elution capacity for total polyphenols and was able to remove other impurities. Therefore, water was chosen to remove impurities and 60% ethanol was selected as the elution solvent for total polyphenols.

[0102] Table 9 Effect of different elution solvents on the process

[0103]

[0104] (4) Investigation of water washing amount

[0105] A 10-bV volume of the taro extract was measured and adjusted to pH 4.0 with 1 mol / L hydrochloric acid. The sample was passed through a macroporous resin column (diameter-to-height ratio of 1:9) at a flow rate of 2 bV / h. Elution was performed with distilled water at a flow rate of 2 bV / h, collecting one fraction per 1 bV. The fractions were then tested for carbohydrates using a molish reagent. The results showed that the molish reaction was negative in the 2 bV eluate, so a 2 bV water elution volume was selected.

[0106] (5) Investigation of the amount of 60% elution solvent

[0107] A pretreated macroporous resin packing was loaded onto a resin column (diameter-to-height ratio of 1:9). 10 BV of balsam pear extract was measured and adjusted to pH 4.0 with 1 mol / L hydrochloric acid. The sample was loaded at a flow rate of 2 BV / h. Sugars were first eluted with 2 BV of distilled water, followed by elution with 60% ethanol at a flow rate of 2 BV / h. Each BV fraction of the eluate was collected and the total polyphenol concentration in the eluate was determined to determine the amount of 60% ethanol required as eluent. The results showed that 4 BV of 60% ethanol was sufficient to elute the total polyphenols from the resin column.

[0108] Table 10 Effect of 60% ethanol elution dosage on process

[0109]

[0110] 4.3 Process Validation

[0111] A pretreated macroporous resin column (diameter-to-height ratio of 1:9) was loaded with 10 BV of the leaf extract of the Chinese yam plant. The pH was adjusted to 4.0 with 1 mol / L hydrochloric acid and loaded at a flow rate of 2 BV / h. The extract was first eluted with 2 BV of distilled water to remove sugars, followed by elution with 4 BV of 60% ethanol at a flow rate of 2 BV / h. The 60% ethanol eluate was recovered, concentrated, and dried to obtain an extract. The extract was weighed and the total phenolic acid content was determined. The total phenolic acid content was 55.97%, effectively increasing the relative content of the active ingredients.

[0112] Table 11 Process verification results

[0113] batch Mass of balsam pear extract (g) Total phenolic acid content (%) 1 1.33 55.71 2 1.34 56.42 3 1.31 55.78

[0114] Example 3 Determination of the content of active ingredients in the extract of the present invention

[0115] 1. Prepare mixed reference solution

[0116] Preparation of reference stock solution: Accurately weigh appropriate amounts of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C reference substances, dissolve them in 60% ethanol, transfer them to a 10 mL volumetric flask, and add 60% ethanol to make up the volume to prepare reference stock solutions with a mass concentration of approximately 1 mg / mL.

[0117] Preparation of mixed reference substance stock solution: Accurately pipette the above reference substance stock solution into a 10mL volumetric flask, adding 3mL of chlorogenic acid, 0.3mL of cryptochlorogenic acid, 0.9mL of rutin, 0.5mL of isochlorogenic acid B, 4mL of isochlorogenic acid A, and 0.6mL of isochlorogenic acid C. Add 60% ethanol to dilute to the mark and shake well.

[0118] Preparation of mixed reference solution: Accurately pipette 0.5 mL of mixed reference stock solution into a 2 mL volumetric flask and dilute to the mark with 60% ethanol.

[0119] 2. Preparation of test solution

[0120] Weigh 12 mg of taro extract accurately, add 60% ethanol and ultrasonically dissolve it, transfer it quantitatively to a 25 mL volumetric flask, dilute it to the scale with 60% ethanol, shake well, and obtain it.

[0121] 3. Liquid chromatography conditions

[0122] Japan Shimadzu Shim-pack GTS chromatographic column (4.6×250mm (HSS), 5μm C18); mobile phase: A is 0.2% phosphoric acid aqueous solution, B is acetonitrile; gradient elution program: 0-20 min, 10% B; 20-45 min, 10%-20% B; 45-70 min, 20% B; 70-80 min, 20%-10% B; column temperature: 30°C; flow rate: 1 mL / min; the mixed reference solution and the test solution were filtered through a 0.22μm microporous filter membrane and injected into the chromatograph for analysis, with an injection volume of 5μL each; the detection wavelength for CA, 4DA, IAB, IAA, and IAC was 325 nm, and the detection wavelength for Rut was 254 nm.

[0123] 4. Calculation formula

[0124] The mixed standard solution and the test solution were subjected to chromatographic analysis. The mass concentration of each target component was obtained by liquid chromatography software analysis, and the content of each component was calculated according to formula (1).

[0125]

[0126] Where: w i——Contents of the six target ingredients in the sample, %;

[0127] i——corresponds to 6 target components respectively;

[0128] ci——mass concentrations of the six target components calculated by the external standard method, μg / mL;

[0129] v——sample fixed volume, mL;

[0130] m——sample mass, mg.

[0131] 5. Content analysis of basil extract

[0132] 5.1 Specificity test

[0133] Under the chromatographic conditions of item "3", the mixed reference solution and the extract test solution were measured respectively to obtain the HPLC chromatogram. Figure 1 Under these chromatographic conditions, the theoretical plate numbers of the corresponding absorption peaks of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C were not less than 10,000, and the resolution of two adjacent chromatographic peaks was greater than 1.5.

[0134] 5.2 Linear Relationship Investigation

[0135] Accurately aspirate the mixed reference solution of each concentration under item "1", inject and analyze under the chromatographic conditions under item "3", and perform regression analysis with the mixed reference concentration as the abscissa (x, μg / mL) and the peak area of ​​the target compound as the ordinate (y). The linear regression equations of the six components are obtained. The results are shown in Table 12.

[0136] Table 12 Linear relationships among the six components

[0137]

[0138] 5.3 Precision test

[0139] The same mixed reference solution was taken and injected continuously for 6 times according to the chromatographic conditions under item "3". The peak areas of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C were measured. The RSDs were 0.24%, 0.83%, 0.21%, 0.48%, 0.23%, and 0.64%, respectively, indicating that the instrument had good precision.

[0140] 5.4 Repeatability test

[0141] The same batch of extracts (N0.202405) were taken and 6 test solutions were prepared in parallel according to the method under "2". The solutions were determined under the chromatographic conditions of "3". The average contents of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C were 14.53%, 0.78%, 3.38%, 1.21%, 10.07%, and 1.76%, respectively. The RSDs were 1.24%, 1.74%, 1.26%, 1.68%, 1.85%, and 1.92%, respectively, indicating that the method had good repeatability.

[0142] 5.5 Stability test

[0143] The same test solution was taken and injected at 0, 2, 4, 8, 16 and 24 hours respectively according to the chromatographic conditions under item "3". The peak areas of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A and isochlorogenic acid C were measured. The RSDs of the results were 0.41%, 0.37%, 0.25%, 0.52%, 0.43% and 0.65%, respectively, indicating that the test solution had good stability within 24 hours.

[0144] 5.6 Sample recovery test

[0145] Accurately weigh 6 portions of 12 mg each of the 12 mg extracts ... Results The average recoveries of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A and isochlorogenic acid C were 100.44%, 99.58%, 100.91%, 96.11%, 100.37% and 100.46%, respectively, with RSDs of 1.57%, 2.17%, 2.19%, 1.62%, 1.58% and 1.95%, respectively.

[0146] 5.7 Sample content determination

[0147] Three different batches of baicalensis extract were used to prepare test solutions according to the method under "2". The peak areas were determined under the chromatographic conditions under "3". The contents of chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C were calculated using the external standard method. The results are shown in Table 13.

[0148] Table 13 Determination of the contents of six components in the extract of taro (%, n = 3)

[0149]

[0150] The beneficial effects of the present invention are demonstrated by the following efficacy tests.

[0151] Test Example 1 Evaluation of the antioxidant activity of extracts in vitro

[0152] 1. Determination of DPPH free radical scavenging ability

[0153] Weigh 19.84 mg of DPPH powder and dissolve it in 250 mL of anhydrous ethanol to prepare a 0.1 mmol / L DPPH working solution. Adjust the absorbance to 1.000 ± 0.002 with anhydrous ethanol immediately before use. Prepare the budding jasmine extract, budding jasmine crude extract, and L-ascorbic acid test sample according to the method in "Example 1." Prepare sample solutions with 60% ethanol to concentrations of 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, and 35 μg / mL, respectively. For the reaction, add 3 mL of each sample solution of varying concentrations to a 10 mL stoppered test tube, followed by 3 mL of the DPPH working solution. Vortex for 10 seconds to mix thoroughly, and allow to react in the dark for 30 minutes. Anhydrous ethanol was used as the reference solution, and three parallels were set up for each group. The absorbance A2 was measured at 517 nm. At the same time, the blank absorbance of the sample was set as A0 and the absorbance of the sample itself was set as A1. The DPPH free radical scavenging rate of each sample group was calculated according to formula (2). The regression equation was fitted with the elimination rate as the vertical axis (y) and the sample solution concentration as the horizontal axis (x). The IC was calculated based on the fitted equation. 50 .

[0154]

[0155] Where: A0——absorbance after reaction of 3mL 60% ethanol + 3mL DPPH working solution;

[0156] A1——Absorbance after reaction of 3mL sample solution + 3mL DPPH working solution;

[0157] A2——Absorbance after reaction of 3mL sample solution + 3mL anhydrous ethanol.

[0158] 2. ABTS + Determination of free radical scavenging ability

[0159] Preparation of ABTS + Working solution: absorb 7mmol / L ABTS + The solution and 10 mL of 2.45 mmol / L potassium persulfate were mixed, vortexed for 1 min, and placed at room temperature in the dark for 16 h to serve as ABTS. +Stock solution. When used, dilute the stock solution with 50 times the amount of anhydrous ethanol to make its absorbance at 734nm 0.800±0.002, which is used as ABTS + Working solution. Prepare the extract of jasmine, crude extract of jasmine, and L-ascorbic acid as the test sample according to the method in "Example 1". Use 60% ethanol to prepare the sample groups with mass concentrations of 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 μg / mL. During the reaction, add 4 mL of ABTS to each 10 mL stoppered test tube. + Then add 1 mL of sample solution of different concentrations, vortex for 10 seconds to mix thoroughly, and place in the dark to react for 10 minutes. With anhydrous ethanol as the reference solution, set up 3 parallels for each group, and measure the absorbance at 734 nm. At the same time, the sample blank absorbance is A0 and the sample absorbance is A1. Calculate ABTS according to formula (3) + Clearance rate, with clearance rate as the ordinate (y) and sample solution concentration as the abscissa (x) to fit the regression equation, and calculate IC based on the fitted equation 50 .

[0160]

[0161] Where: A0——1mL 60% ethanol + 4mL ABTS + Absorbance of the working solution after reaction;

[0162] A1——1mL sample solution + 4mL ABTS + Absorbance of the working solution after reaction;

[0163] A2——Absorbance after reaction of 1mL sample solution + 4mL anhydrous ethanol.

[0164] 3. Results and Discussion

[0165] 3.1 Analysis of the antioxidant capacity of baicalensis extract in vitro

[0166] 3.1.1 DPPH free radical scavenging ability

[0167] like Figure 2 As shown in the results, when the mass concentration was 2.5-27.5 μg / mL, the DPPH radical scavenging rate of the taro extract increased with the increase of sample mass concentration, from 10.87% to 92.28%. The fitted linear regression equation was y=3.277 7x+4.101 4, R 2=0.996 4. Furthermore, at the same concentration, the DPPH radical scavenging ability of the araucaria extract was higher than that of the araucaria crude extract, but weaker than that of L-ascorbic acid. Under the experimental conditions, when the L-ascorbic acid concentration reached 7.50 μg / mL, the DPPH radical scavenging rate was observed to have significantly increased to over 96%, and then the overall trend became stable with further increase in concentration. By fitting the linear regression equation, the relationship between the mass concentration of the araucaria crude extract and the scavenging rate was obtained as y = 1.656 1x + 1.980 5 (2.5-35 μg / mL, R 2 =0.996 3), the relationship between L-ascorbic acid mass concentration and clearance rate is y = 13.909x-8.4018 (2.5 ~ 7.5 μg / mL, R 2 =0.998 1), and the IC values ​​of DPPH radical scavenging rates of the basil extract, crude extract, and L-ascorbic acid were calculated. 50 The values ​​were 13.91, 28.99, and 4.20 μg / mL, respectively. 50 The IC 50 The value was significantly lower than that of its crude extract, indicating that some inactive or low-activity components were removed during the purification process, thereby improving its scavenging efficiency for DPPH free radicals, which fully illustrates the importance of the purification step in improving the antioxidant properties of natural products.

[0168] 3.1.2ABTS + Free radical scavenging ability

[0169] like Figure 3 As shown in the figure, at the same mass concentration, the extract of balsam pear had an effect on ABTS. + The free radical scavenging ability of the extract was significantly stronger than that of the crude extract. The scavenging rates of both increased steadily with the increase of mass concentration, and the growth trend was similar. This finding highlights the importance of the purification process in improving antioxidant activity. In addition, when the mass concentration of the taro extract was 50 μg / mL, its ABTS + The clearance rate exceeded 90%, which fully demonstrated the excellent efficacy of the leucophylla extract as a potential antioxidant. By fitting the linear regression equation, the relationship between the mass concentration of the leucophylla extract and the clearance rate was obtained as y = 1.858 5x + 1.263 9 (5-50 μg / mL, R 2 =0.995 3), the relationship between L-ascorbic acid concentration and clearance rate is y = 4.6092x + 8.3791 (5-20 μg / mL, R 2 =0.9927). Under this test system, the ABTS of the budding extract + Free radical scavenging rate IC 50 is 26.22 μg / mL, while the IC50 Although the scavenging ability of balsam pear extract is lower than that of L-ascorbic acid, considering that it is derived from natural plants and has higher biosafety, it is still worthy of further research and development.

[0170] 4. Conclusion

[0171] The present invention prepares a leucanthemum extract, and determines the six active ingredients in the extract by high performance liquid chromatography, including chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C. The total content of the six active ingredients in the leucanthemum extract is 31.76%, among which chlorogenic acid, isochlorogenic acid A and rutin have the highest contents, which are 14.53%, 10.06% and 3.39% respectively, indicating that these ingredients occupy an important position in the leucanthemum extract. In addition, the leucanthemum extract has high DPPH and ABTS + In free radical scavenging tests, they showed low IC 50 The value further confirms its potential as a natural potential antioxidant. Future research can further explore other biological activities and mechanisms of action of the extract of Paddy Field to promote its wider and deeper development and utilization.

[0172] Experimental Example 2 Comparison of in vitro antioxidant activity of the extract obtained by the present invention and the extract reported in the literature

[0173] The extract preparation method reported in the literature is as follows: Weigh 100g of white balsam pear leaf powder into a conical flask, add 3 volumes of 95% ethanol, and ultrasonically extract. The extract is filtered and concentrated under reduced pressure to obtain a paste. Repeat the extraction 3-4 times. The concentrated extract is combined and dissolved in an appropriate amount of 45°C distilled water. Add 3 volumes of petroleum ether (30-60°C) and repeat the extraction 3-4 times. The resulting aqueous phases are combined, concentrated under reduced pressure, and freeze-dried to obtain a crude extract of total polyphenols from white balsam pear leaf. Take 300mg of the crude extract of total polyphenols from white balsam pear leaf, dissolve it in water to a solution of 1.0mg / mL, adjust the pH to 3.0, and apply it to a pre-treated HPD100 resin bed (resin dosage 40g) at a volume flow rate of 20mL / min. The column is loaded with 300mL of sample. The macroporous resin was then rinsed with water and then eluted with 400 mL of 50% ethanol solution at pH 6.0 at a flow rate of 20 mL / min. The 60% ethanol eluate was collected, concentrated under reduced pressure, and freeze-dried to obtain the polyphenol extract from the leaves of the white taro leaf. (Cen Yesheng, Li Xiaolong, Chen Shujuan, et al. Process optimization of purification of total polyphenols from the leaves of the white taro leaf using macroporous adsorption resin [J]. Chinese Herbal Medicine, 2019, 50(13): 3071-3076.)

[0174] 1. DPPH free radical scavenging ability

[0175] The experimental results are shown in Table 14.

[0176] Table 14 Comparison of DPPH free radical scavenging ability

[0177] Extract of the present invention Literature reference extract <![CDATA[IC 50 ]]> 13.91 μg / mL 19.06 μg / mL

[0178] 2. ABTS + Free radical scavenging ability

[0179] The experimental results are shown in Table 15.

[0180] Table 15 ABTS + Comparison of free radical scavenging ability

[0181] Extract of the present invention Literature reference extract <![CDATA[IC 50 ]]> 26.22 μg / mL 33.15 μg / mL

[0182] Conclusion: The in vitro antioxidant effect of the taro extract prepared by the present invention is significantly stronger than that of the reference extract.

Claims

1. A method for preparing a balsam pear extract having an antioxidant effect, characterized in that: The invention uses fresh leek as raw material, adopts enzyme-assisted extraction technology, macroporous adsorption resin purification and drying to obtain leek extract; the extract contains chlorogenic acid, cryptochlorogenic acid, rutin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C in an amount of not less than 30% w / w, and the mass fraction of total phenolic acids is not less than 55% w / w; The preparation method of the extract comprises the following steps: a. Rinse the freshly harvested taro with clean water, dry it in an oven at 50°C, and then grind it and pass it through a 60-mesh sieve to obtain taro powder; b. Weigh fine powder of taro leaf, add 35-55 times the amount of distilled water, adjust the pH to 4.5-5.5 with 1 mol / L hydrochloric acid, then add 0.4%-0.8% cellulase or pectinase, mix thoroughly, and perform enzymatic hydrolysis in a 50°C water bath for 60-120 minutes. Finally, inactivate in a 95°C water bath for 10 minutes, and filter to obtain a taro leaf extract. After drying the extract, a crude taro leaf extract is obtained. c. Take 450 mL of the extract, adjust the pH to 4.0 with 1 mol / L hydrochloric acid, pass it through a chromatography column filled with 45 mL of HPD-450 macroporous resin at a flow rate of 90 mL / h, and then elute with 180 mL of 60% ethanol; collect the ethanol elution fraction, add anhydrous ethanol to adjust the ethanol concentration to 75%, refrigerate it at 4°C, filter it after 16 hours, recover the ethanol under reduced pressure until there is no alcohol smell, and dry it to obtain the taro extract.

2. The method for preparing the oleander extract according to claim 1, wherein: The extract contains 12.0% to 16.0% w / w of chlorogenic acid, 0.6% to 0.9% w / w of cryptochlorogenic acid, 2.5% to 4.0% w / w of rutin, 8.0% to 12.0% w / w of isochlorogenic acid A, 0.8% to 1.5% w / w of isochlorogenic acid B, and 1.5% to 2.0% w / w of isochlorogenic acid C.

3. The method for preparing the taro extract according to claim 1, wherein: b) The pH is adjusted to 5.0; the enzyme is 0.6% cellulase.

4. Use of the baicalensis extract prepared by the preparation method according to any one of claims 1 to 3 in the preparation of health foods having an antioxidant effect.

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