CN118130410B - Method for measuring content of tea polyphenol in tea leaves - Google Patents
Method for measuring content of tea polyphenol in tea leaves Download PDFInfo
- Publication number
- CN118130410B CN118130410B CN202410560714.1A CN202410560714A CN118130410B CN 118130410 B CN118130410 B CN 118130410B CN 202410560714 A CN202410560714 A CN 202410560714A CN 118130410 B CN118130410 B CN 118130410B
- Authority
- CN
- China
- Prior art keywords
- tea
- tea polyphenol
- solution
- content
- gallic acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 235000013824 polyphenols Nutrition 0.000 title claims abstract description 97
- 150000008442 polyphenolic compounds Chemical class 0.000 title claims abstract description 88
- 238000000034 method Methods 0.000 title claims abstract description 51
- 241001122767 Theaceae Species 0.000 title claims abstract 36
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims abstract description 51
- 229920002678 cellulose Polymers 0.000 claims abstract description 46
- 239000001913 cellulose Substances 0.000 claims abstract description 46
- 239000004005 microsphere Substances 0.000 claims abstract description 38
- 239000003153 chemical reaction reagent Substances 0.000 claims abstract description 11
- 230000008569 process Effects 0.000 claims abstract description 9
- LNTHITQWFMADLM-UHFFFAOYSA-N gallic acid Chemical compound OC(=O)C1=CC(O)=C(O)C(O)=C1 LNTHITQWFMADLM-UHFFFAOYSA-N 0.000 claims description 91
- 229940074391 gallic acid Drugs 0.000 claims description 43
- 235000004515 gallic acid Nutrition 0.000 claims description 43
- 239000000243 solution Substances 0.000 claims description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 238000002835 absorbance Methods 0.000 claims description 18
- -1 aluminum ions Chemical class 0.000 claims description 18
- 238000000605 extraction Methods 0.000 claims description 15
- 238000002386 leaching Methods 0.000 claims description 15
- 238000001035 drying Methods 0.000 claims description 13
- 238000001914 filtration Methods 0.000 claims description 11
- 239000012452 mother liquor Substances 0.000 claims description 11
- 239000008367 deionised water Substances 0.000 claims description 10
- 229910021641 deionized water Inorganic materials 0.000 claims description 10
- 239000002994 raw material Substances 0.000 claims description 10
- 229910052782 aluminium Inorganic materials 0.000 claims description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 8
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- 239000010413 mother solution Substances 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 6
- 229910052708 sodium Inorganic materials 0.000 claims description 6
- 239000011734 sodium Substances 0.000 claims description 6
- 238000005303 weighing Methods 0.000 claims description 6
- 239000012224 working solution Substances 0.000 claims description 6
- 238000007873 sieving Methods 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 4
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 4
- 230000003213 activating effect Effects 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 4
- 229920006395 saturated elastomer Polymers 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 239000002253 acid Substances 0.000 claims description 3
- 239000012490 blank solution Substances 0.000 claims description 3
- 238000010790 dilution Methods 0.000 claims description 3
- 239000012895 dilution Substances 0.000 claims description 3
- 238000010298 pulverizing process Methods 0.000 claims description 3
- 239000011550 stock solution Substances 0.000 claims description 3
- 239000012085 test solution Substances 0.000 claims description 3
- 238000010979 pH adjustment Methods 0.000 claims description 2
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 2
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 2
- RYYVLZVUVIJVGH-UHFFFAOYSA-N caffeine Chemical compound CN1C(=O)N(C)C(=O)C2=C1N=CN2C RYYVLZVUVIJVGH-UHFFFAOYSA-N 0.000 abstract description 10
- 229910021645 metal ion Inorganic materials 0.000 abstract description 9
- 150000001413 amino acids Chemical class 0.000 abstract description 6
- LPHGQDQBBGAPDZ-UHFFFAOYSA-N Isocaffeine Natural products CN1C(=O)N(C)C(=O)C2=C1N(C)C=N2 LPHGQDQBBGAPDZ-UHFFFAOYSA-N 0.000 abstract description 5
- 229960001948 caffeine Drugs 0.000 abstract description 5
- VJEONQKOZGKCAK-UHFFFAOYSA-N caffeine Natural products CN1C(=O)N(C)C(=O)C2=C1C=CN2C VJEONQKOZGKCAK-UHFFFAOYSA-N 0.000 abstract description 5
- 239000000126 substance Substances 0.000 abstract description 5
- 238000003809 water extraction Methods 0.000 abstract description 3
- 238000004458 analytical method Methods 0.000 abstract description 2
- 238000007254 oxidation reaction Methods 0.000 abstract description 2
- 230000020477 pH reduction Effects 0.000 abstract 1
- 244000269722 Thea sinensis Species 0.000 description 117
- 235000013616 tea Nutrition 0.000 description 114
- 239000012071 phase Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 8
- 238000005259 measurement Methods 0.000 description 8
- ADRVNXBAWSRFAJ-UHFFFAOYSA-N catechin Natural products OC1Cc2cc(O)cc(O)c2OC1c3ccc(O)c(O)c3 ADRVNXBAWSRFAJ-UHFFFAOYSA-N 0.000 description 7
- 235000005487 catechin Nutrition 0.000 description 7
- 229920000297 Rayon Polymers 0.000 description 5
- 235000009569 green tea Nutrition 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 150000001765 catechin Chemical class 0.000 description 4
- 238000004128 high performance liquid chromatography Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- PFTAWBLQPZVEMU-DZGCQCFKSA-N (+)-catechin Chemical compound C1([C@H]2OC3=CC(O)=CC(O)=C3C[C@@H]2O)=CC=C(O)C(O)=C1 PFTAWBLQPZVEMU-DZGCQCFKSA-N 0.000 description 3
- WMBWREPUVVBILR-WIYYLYMNSA-N (-)-Epigallocatechin-3-o-gallate Chemical compound O([C@@H]1CC2=C(O)C=C(C=C2O[C@@H]1C=1C=C(O)C(O)=C(O)C=1)O)C(=O)C1=CC(O)=C(O)C(O)=C1 WMBWREPUVVBILR-WIYYLYMNSA-N 0.000 description 3
- QGJOPFRUJISHPQ-UHFFFAOYSA-N Carbon disulfide Chemical compound S=C=S QGJOPFRUJISHPQ-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- WMBWREPUVVBILR-UHFFFAOYSA-N GCG Natural products C=1C(O)=C(O)C(O)=CC=1C1OC2=CC(O)=CC(O)=C2CC1OC(=O)C1=CC(O)=C(O)C(O)=C1 WMBWREPUVVBILR-UHFFFAOYSA-N 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229950001002 cianidanol Drugs 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000007865 diluting Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 2
- 108090000790 Enzymes Proteins 0.000 description 2
- 102000004190 Enzymes Human genes 0.000 description 2
- 238000005903 acid hydrolysis reaction Methods 0.000 description 2
- 239000008346 aqueous phase Substances 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 229940088598 enzyme Drugs 0.000 description 2
- ZOOODBUHSVUZEM-UHFFFAOYSA-N ethoxymethanedithioic acid Chemical compound CCOC(S)=S ZOOODBUHSVUZEM-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000002798 spectrophotometry method Methods 0.000 description 2
- 238000005211 surface analysis Methods 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- 239000012991 xanthate Substances 0.000 description 2
- LSHVYAFMTMFKBA-TZIWHRDSSA-N (-)-epicatechin-3-O-gallate Chemical compound O([C@@H]1CC2=C(O)C=C(C=C2O[C@@H]1C=1C=C(O)C(O)=CC=1)O)C(=O)C1=CC(O)=C(O)C(O)=C1 LSHVYAFMTMFKBA-TZIWHRDSSA-N 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 208000024172 Cardiovascular disease Diseases 0.000 description 1
- 235000009024 Ceanothus sanguineus Nutrition 0.000 description 1
- 108010059892 Cellulase Proteins 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 238000010268 HPLC based assay Methods 0.000 description 1
- 240000003553 Leptospermum scoparium Species 0.000 description 1
- 235000015459 Lycium barbarum Nutrition 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- ZCHPKWUIAASXPV-UHFFFAOYSA-N acetic acid;methanol Chemical compound OC.CC(O)=O ZCHPKWUIAASXPV-UHFFFAOYSA-N 0.000 description 1
- 229930014669 anthocyanidin Natural products 0.000 description 1
- 235000008758 anthocyanidins Nutrition 0.000 description 1
- 230000003064 anti-oxidating effect Effects 0.000 description 1
- 235000010323 ascorbic acid Nutrition 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- 239000011668 ascorbic acid Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000008280 blood Substances 0.000 description 1
- 210000004369 blood Anatomy 0.000 description 1
- 230000036772 blood pressure Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229940106157 cellulase Drugs 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 208000002925 dental caries Diseases 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229930003935 flavonoid Natural products 0.000 description 1
- 235000017173 flavonoids Nutrition 0.000 description 1
- 150000002215 flavonoids Chemical class 0.000 description 1
- NWKFECICNXDNOQ-UHFFFAOYSA-N flavylium Chemical compound C1=CC=CC=C1C1=CC=C(C=CC=C2)C2=[O+]1 NWKFECICNXDNOQ-UHFFFAOYSA-N 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 208000015181 infectious disease Diseases 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000012417 linear regression Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 230000000144 pharmacologic effect Effects 0.000 description 1
- 150000007965 phenolic acids Chemical class 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229940096992 potassium oleate Drugs 0.000 description 1
- MLICVSDCCDDWMD-KVVVOXFISA-M potassium;(z)-octadec-9-enoate Chemical compound [K+].CCCCCCCC\C=C/CCCCCCCC([O-])=O MLICVSDCCDDWMD-KVVVOXFISA-M 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- UGTZMIPZNRIWHX-UHFFFAOYSA-K sodium trimetaphosphate Chemical compound [Na+].[Na+].[Na+].[O-]P1(=O)OP([O-])(=O)OP([O-])(=O)O1 UGTZMIPZNRIWHX-UHFFFAOYSA-K 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 238000006277 sulfonation reaction Methods 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 238000001195 ultra high performance liquid chromatography Methods 0.000 description 1
- 230000002485 urinary effect Effects 0.000 description 1
Landscapes
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
The invention belongs to the technical field of tea chemical analysis, and particularly relates to a method for measuring tea polyphenol content in tea. According to the invention, on the basis of extracting tea polyphenol in tea leaves by a water extraction method, cellulose porous microspheres loaded with metal ions are used for adsorbing the tea polyphenol, the tea polyphenol is extracted by ethyl acetate after acidification, and then the content of the tea polyphenol is measured by using a Fu Lin Fen reagent, so that the content of the tea polyphenol can be more accurately measured, the interference of amino acid, caffeine, cellulose and the like in a tea polyphenol extracting solution is eliminated to a certain extent, and the stability of the tea polyphenol is increased, so that the loss of the content of the tea polyphenol caused by oxidization in the operation process is avoided.
Description
Technical Field
The invention belongs to the technical field of tea chemical analysis, and particularly relates to a method for measuring tea polyphenol content in tea.
Background
Tea polyphenols (Tea polyphenols), also called tea tanning and tea tannin, mainly comprises four substances of catechins, flavonoids, anthocyanidins and phenolic acid, is a mixture of polyphenols existing in tea trees, and plays an important role in the formation of color, aroma and quality of tea. The tea polyphenol has strong antioxidation, and has pharmacological effects of resisting tumor, preventing and treating cardiovascular diseases, lowering blood pressure, reducing blood sugar, inhibiting bacteria, resisting virus, preventing urinary system infection, resisting dental caries, protecting teeth, resisting ultraviolet irradiation, etc., and is the primary component of health care function of tea. In the industries of tea and tea products, the accurate determination of tea polyphenol has very important practical significance.
The Chinese patent with publication number CN110161166A discloses a rapid detection method for EGCG content in tea polyphenol; specifically disclosed is: the method for efficiently and rapidly detecting the EGCG content in the tea polyphenol by utilizing the ultra-high performance liquid chromatography detection technology adopts a C18 chromatographic column, takes water-glacial acetic acid-methanol with a certain proportion as a mobile phase, and realizes the rapid detection of the EGCG content in the tea polyphenol by a gradient elution mode.
The Chinese patent with publication number CN111202788A discloses an extraction process for optimizing green tea polyphenol by using complex enzyme of response surface method; specifically disclosed is: the method comprises the following steps: preparing materials; determining the content of tea polyphenol; single factor experiment; optimizing a tea polyphenol extraction process by a response surface analysis method; the green tea polyphenol is extracted by adopting a complex enzyme-assisted organic solvent extraction method, the principle of environmental protection, low carbon and low cost is considered, low-price nontoxic ethanol is taken as an extracting agent, and the process is optimized through a single factor test, a Box-Behnken test design and response surface analysis, so that the optimal extraction process conditions are cellulase and pectase dosage, solvent concentration, feed-liquid ratio, extraction temperature, extraction time and pH value.
The current latest national standard for detecting tea polyphenol is GB/T8313-2018 (method for detecting tea polyphenol and catechin content in tea) which uses spectrophotometry to detect the tea polyphenol content in tea.
However, in the above prior art, the extracted tea polyphenol exists in the form of an aqueous solution, and the measurement is inaccurate due to the fact that the spectrophotometry measurement consumes a long time and the tea polyphenol has strong reducibility and is easily oxidized in the process.
In addition, the tea polyphenol extract obtained according to the existing standards contains substances such as amino acids, caffeine, cellulose and the like in addition to tea polyphenol, and these components may interfere with the measurement of the content of tea polyphenol.
In addition, since the HPLC assay specified by the national standard requires gallic acid as a parameter of a calculation formula, and gallic acid also has a relatively active property and can be decomposed in a solution, a technical scheme capable of improving the storage stability of gallic acid is urgently needed in the art to ensure the accuracy of the content of gallic acid as a calculation parameter of the content of tea polyphenol.
Disclosure of Invention
In order to solve the problems, the invention provides a method for measuring the content of tea polyphenol in tea, which comprises the following steps:
(1) Pulverizing folium Camelliae sinensis raw materials, sieving with 40 mesh sieve, adding deionized water, leaching at 85-95deg.C, and filtering to obtain folium Camelliae sinensis leaching solution;
(2) Adding the porous cellulose microspheres loaded with aluminum ions into tea leaching solution, adjusting the pH to 6.0-6.5, and standing at 50-60 ℃ for 60-90min to obtain porous cellulose microspheres loaded with tea polyphenol salt;
(3) Treating the porous cellulose microspheres loaded with tea polyphenol salt obtained in the step (2) by dilute acid to dissolve the tea polyphenol salt and obtain tea polyphenol acidolysis solution;
(4) Adding ethyl acetate into the acidolysis solution of tea polyphenol for extraction to obtain an ethyl acetate phase;
(5) Concentrating ethyl acetate phase at 60deg.C under reduced pressure to obtain tea polyphenols mother liquor;
(6) Reacting the diluted solution of the tea polyphenol mother solution obtained in the step (5) with a Fu Lin Fen reagent, adding 7.5% Na 2CO3 solution, standing, measuring absorbance at 765nm, and calculating the tea polyphenol content according to the following formula:
In the method, in the process of the invention, The content of tea polyphenol is that A is the absorbance of a sample test solution, A 0 is the absorbance of a reagent blank solution, V is the volume of a tea polyphenol mother solution,As a dilution factor, the concentration of the organic solvent,Is the slope of the gallic acid standard curve,Is the dry matter content of the tea leaves,The quality of the tea is the quality of the tea.
Further, the aluminum ion-loaded cellulose porous microspheres were prepared as follows: preparing a saturated aqueous solution of hydrated aluminum sulfate, adding cellulose porous microspheres, oscillating and activating at 75 ℃ for 30min, filtering, washing and drying to obtain the product.
Further, the mass ratio of the hydrated aluminum sulfate to the cellulose porous microspheres is 1:5.
Further, the dosage of the hydrated aluminum sulfate is 30-50% of the weight of the tea raw material.
Further, the washing of the aluminum ion-loaded cellulose porous microspheres comprises washing with water 3 to 5 times.
Further, the cellulose porous microspheres may be purchased commercially or may be prepared by methods known in the art, for example one such method comprises: preparing cellulose viscose: 30 g of absorbent cotton is immersed in 270 g of 19% sodium hydroxide aqueous solution, alkalized for 2 hours at room temperature, then filtered by suction, lye is squeezed out, and the mixture is put into a closed container and aged for 3 days. Then 18 g of carbon disulfide is added into the mixture, sulfonation is carried out for about 5 hours at 30 ℃ to obtain orange viscose, 300 g of 6% sodium hydroxide solution is added into the mixture, and the mixture is stirred uniformly to obtain cellulose xanthate viscose; preparing crosslinked cellulose microspheres: the oil phase dispersant 900 g chlorobenzene, 320 g carbon tetrachloride and 2g potassium oleate were mixed and stirred for 30 minutes to homogenize. Uniformly mixing 300 g of aqueous phase cellulose xanthate viscose, 50 g of polyethylene glycol with a pore-forming agent polymerization degree of 200 and 30 g of cross-linking agent sodium trimetaphosphate, adjusting the pH value to 10.2, then adding the aqueous phase into the oil phase, adjusting the stirring speed to disperse the viscose into liquid beads with proper size, heating to 50 ℃, reacting for 1.5 hours, heating to 90 ℃, preserving heat for 2 hours, naturally cooling to room temperature under stirring, and filtering to obtain cross-linked cellulose microspheres containing the pore-forming agent; post-treatment: washing cellulose microsphere with a large amount of tap water, soaking overnight with 7.5% alcohol, washing with a large amount of deionized water, and filtering to obtain cellulose porous microsphere.
Further, the step (1) comprises adding 10-20 times of deionized water by volume, and leaching for 2-3 times at 85-95 ℃.
Further, step (2) includes pH adjustment using 10% sodium bicarbonate solution.
Further, the step (3) comprises treating with 2mol/L dilute sulfuric acid or 4mol/L hydrochloric acid for 30-60min under stirring.
Further, in the step (4), an equal volume or twice the volume of ethyl acetate is added to the acid hydrolysis solution of tea polyphenol.
Further, the extraction in step (4) comprises 3 times of extraction at 40-50 ℃ for 20-30min each, and then combining ethyl acetate phases.
Further, the dry matter content of the tea leaves is determined as follows: and (3) drying the tea sample at 120 ℃ for 1h, cooling to room temperature under the drying condition, weighing, and taking the ratio of the weight of the dried tea sample to the weight of the tea sample before drying as the dry matter content.
Further, the gallic acid standard curve was obtained as follows:
weighing 0.1100g of gallic acid, dissolving with a proper amount of water, transferring to a 100ml volumetric flask, fixing the volume to a scale mark with water, and shaking uniformly;
Respectively transferring 0.0 mL, 1.0mL, 2.0mL, 3.0mL, 4.0mL and 5.0mL of gallic acid standard stock solution into a 100mL volumetric flask, respectively fixing the volume to scale marks, and shaking uniformly to obtain gallic acid working solutions with the concentrations of 0, 10 mug/mL, 20 mug/mL, 30 mug/mL, 40 mug/mL and 50 mug/mL;
and (3) reacting the gallic acid working solution with a Fu Lin Fen reagent, adding a 7.5% Na 2CO3 solution, standing, measuring the absorbance at 765nm, and drawing a curve of absorbance and concentration to obtain the gallic acid standard curve.
The beneficial effects of the invention are that
The metal ion precipitation method is a common chemical extraction method for extracting tea polyphenol, however, although the purity of the tea polyphenol obtained by the metal ion precipitation method is high, the method also has the defects of low extraction rate, low safety and the like.
In order to overcome the defect that the purity of the extracted tea polyphenol is not high in the water extraction method, the inventor considers the advantages of the extraction method combined with the metal ion precipitation method, and develops a combined extraction method, wherein the tea polyphenol is adsorbed by utilizing ion complexation reaction on the basis of the water extraction method, and then the content is measured, so that the content of the finally measured tea polyphenol is found to be more approximate to the total content of catechin measured by adopting an HPLC method in GB/T8313-2018 in the intermediate treatment process, and the interference of amino acid, caffeine, cellulose and the like in the tea polyphenol extract on the content measurement of the tea polyphenol is eliminated to a certain extent in the intermediate treatment.
Further, the adsorption method of the cellulose porous microsphere loaded with metal ions, which is adopted by the invention, also unexpectedly increases the stability of tea polyphenol, as demonstrated by the embodiment of the invention, the tea polyphenol adsorbed by the cellulose porous microsphere loaded with metal ions is stable for up to 36 hours (the tea polyphenol prepared by the general method can be stored for 24 hours at the temperature of 4 ℃ at most), and is believed to be possibly adsorbed into the cellulose porous microsphere, so that the cellulose porous microsphere is isolated from the outside to a certain extent, thereby avoiding oxidation by air and improving the stability.
Drawings
FIG. 1 is a schematic flow chart of the method of the present invention.
Detailed Description
The present invention is further illustrated below with reference to specific examples, which are not intended to limit the invention in any way. Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art.
Example 1: the embodiment provides a method for measuring the content of tea polyphenol in tea, which comprises the following steps:
(1) Pulverizing 2g of tea raw material (green tea of a certain variety), sieving with a 40 mesh sieve, adding 10ml of deionized water, leaching at 90deg.C for 30 min/time for 3 times, filtering, and mixing to obtain tea leaching solution;
(2) Preparing cellulose porous microspheres loaded with aluminum ions: preparing a saturated aqueous solution of 0.8g of hydrated aluminum sulfate, adding 4g of cellulose porous microspheres, oscillating and activating at 75 ℃ for 30min, filtering, washing with water for 3 times, and drying to obtain the product;
(3) Adding the porous cellulose microspheres loaded with aluminum ions obtained in the step (2) into tea leaching solution, adjusting the pH to 6.4, and standing at 56 ℃ for 80min to obtain porous cellulose microspheres loaded with tea polyphenol salt;
(4) Treating the porous cellulose microsphere loaded with tea polyphenol salt obtained in the step (3) with 2mol/L dilute sulfuric acid for 50min to dissolve the tea polyphenol salt and obtain tea polyphenol acidolysis solution;
(5) Adding twice the volume of ethyl acetate into the acidolysis solution of tea polyphenol, extracting for 30min at 45 ℃ for 3 times, and then combining ethyl acetate phases;
(6) Concentrating the ethyl acetate phase at 60 ℃ under reduced pressure to obtain 10ml of tea polyphenol mother liquor;
(7) Diluting 1ml of the tea polyphenol mother liquor obtained in the step (6) by 100 times, taking 1ml of the tea polyphenol mother liquor to be placed in a graduated test tube, adding 5ml of Fu Lin Fen reagent to react, shaking uniformly, reacting for 5min, adding 4ml of 7.5% Na 2CO3 solution, adding water to fix volume to scale, shaking uniformly, standing at room temperature for 60min, measuring absorbance by a spectrophotometer at 765nm wavelength by using a 10mm cuvette, and calculating the tea polyphenol content according to the following formula:
In the method, in the process of the invention, The content of tea polyphenol is that A is the absorbance of a sample test solution, A 0 is the absorbance of a reagent blank solution, V is the volume of a tea polyphenol mother solution,As a dilution factor, the concentration of the organic solvent,Is the slope of the gallic acid standard curve,Is the dry matter content of the tea leaves,The quality of the tea is the quality of the tea.
The dry matter content of the tea leaves is determined as follows: and (3) drying the tea sample at 120 ℃ for 1h, cooling to room temperature under the drying condition, weighing, and taking the ratio of the weight of the dried tea sample to the weight of the tea sample before drying as the dry matter content.
The gallic acid standard curve was obtained as follows:
weighing 0.1100g of gallic acid, dissolving with a proper amount of water, transferring to a 100ml volumetric flask, fixing the volume to a scale mark with water, and shaking uniformly;
respectively transferring 0.0, 1.0, 2.0, 3.0, 4.0 and 5.0mL of gallic acid standard stock solution into a 100mL volumetric flask, respectively fixing the volume to scale marks, and shaking uniformly to obtain gallic acid working solutions with the concentrations of 0, 10, 20, 30, 40 and 50 mug/mL;
Measuring absorbance of the gallic acid working solution at 765nm as described above, drawing a curve of absorbance and concentration to obtain a gallic acid standard curve, and carrying out linear regression on the gallic acid content (Y) and absorbance (X) to obtain a standard curve equation: y=0.01294x+0.0844, r 2 = 0.9996.
The tea polyphenol content in the tea leaf raw material is 19.92% by the measurement of the example.
Example 2: the embodiment provides a method for measuring the content of tea polyphenol in tea, which comprises the following steps:
(1) Crushing 2g of tea raw material (green tea, the variety of which is the same as that of example 1), sieving with a 40-mesh sieve, adding 10ml of deionized water, leaching at 90 ℃ for 30 min/time and 3 times, filtering and combining to obtain tea leaching liquor, and concentrating to 10ml to obtain tea polyphenol mother liquor;
(2) Diluting 1ml of the tea polyphenol mother liquor obtained in the step (1) by 100 times, taking 1ml of the tea polyphenol mother liquor to react in a graduated test tube, adding 5ml of Fu Lin Fen reagent, shaking uniformly, reacting for 5min, adding 4ml of 7.5% Na 2CO3 solution, adding water to fix volume to scale, shaking uniformly, standing at room temperature for 60min, measuring absorbance by a spectrophotometer at 765nm wavelength by using a 10mm cuvette, and calculating the tea polyphenol content in the tea raw material as 26.26% as described in the example 1.
Example 3: the embodiment provides a method for measuring the content of tea polyphenol in tea, which comprises the following steps:
Crushing 2g of tea raw material (green tea, the variety of which is the same as that of example 1), sieving with a 40-mesh sieve, adding 10ml of deionized water, leaching at 90 ℃ for 30 min/time and 3 times, filtering and combining to obtain tea leaching liquor, and concentrating to 10ml to obtain tea polyphenol mother liquor;
The total amount of catechins in the tea polyphenol mother liquor was measured by an HPLC method specified in GB/T8313-2018, and the content of catechins in the tea leaf raw material was 21.73%.
As can be seen from a comparison of examples 1 to 3, the content of tea polyphenols measured in example 2 is significantly higher than the total amount of catechins measured by HPLC method in GB/T8313-2018, indicating that amino acids, caffeine, cellulose and the like (especially reducing amino acids, ascorbic acid and the like) in the tea polyphenols extract have a large interference on the measurement of tea polyphenols content.
Although the porous cellulose microsphere loaded with metal ions is adopted to adsorb the tea extract in the embodiment 1, the loss of tea polyphenol can be caused to a certain extent, the finally measured tea polyphenol content is closer to the total catechin content measured by adopting the HPLC method in GB/T8313-2018, which proves that the interference of amino acid, caffeine, cellulose and the like in the tea polyphenol extract on the measurement of the tea polyphenol content is eliminated to a certain extent by the intermediate treatment, and the measurement result is more accurate and reliable.
Example 4: this example investigated the effect of adsorption of metal ion loaded cellulose porous microspheres on tea polyphenol stability.
(1) 0.4G of gallic acid is weighed and dissolved in 30ml of deionized water,
(2) Preparing cellulose porous microspheres loaded with aluminum ions: preparing a saturated aqueous solution of 0.8g of hydrated aluminum sulfate, adding 4g of cellulose porous microspheres, oscillating and activating at 75 ℃ for 30min, filtering, washing with water for 3 times, and drying to obtain the product;
(3) Adding the porous cellulose microspheres loaded with aluminum ions obtained in the step (2) into the gallic acid solution obtained in the step (1), adjusting the pH to 6.4, and standing at 56 ℃ for 80min to obtain porous cellulose microspheres loaded with gallate;
Setting 9 experimental groups, wherein each experimental group exposes the cellulose porous microsphere loaded with gallate to air at room temperature for 0h, 6h, 12h, 18h, 24h, 30h, 36h and 48h;
(4) Treating the gallic acid salt-loaded cellulose porous microspheres obtained in the step (3) with 2mol/L dilute sulfuric acid for 50min to dissolve the gallic acid salt and obtain gallic acid hydrolysis solution;
(5) Adding ethyl acetate into gallic acid acidolysis solution, extracting at 45deg.C for 3 times for 30min, and mixing ethyl acetate phases;
(6) Concentrating ethyl acetate phase at 60deg.C under reduced pressure to obtain 10ml gallic acid mother liquor;
(7) After diluting 1ml of the gallic acid mother solution obtained in the step (6) 100 times, the absorbance was measured as in example 1 by taking 1ml of the diluted solution, and the amount of gallic acid in the gallic acid mother solution was calculated.
Meanwhile, a control group is also arranged, and the deionized water solution of gallic acid is directly exposed to the air for 0h, 6h, 12h, 18h, 24h, 30h, 36h and 48h at room temperature, and then the content of gallic acid in the solution is determined as described above. The results are shown in Table 1:
TABLE 1 theoretical and measured values of gallic acid content
From the results of Table 1, it was found that the measured amount of gallic acid was slightly changed (reduced by not more than 6%) during the exposure of the gallic acid salt-loaded cellulose porous microspheres to air at room temperature for 0 to 36 hours, indicating that substantially no gallic acid was oxidized, and by 48 hours, the measured amount of gallic acid was reduced by 13%, indicating that gallic acid was oxidized in a larger amount and the stability was lower.
Further, as is clear from the results of Table 1, the intermediate treatment step of adsorbing gallic acid with the metal ion-loaded cellulose porous microspheres of the present invention can adsorb most of gallic acid, and the loss rate is low. The method for determining the tea polyphenol content in the tea leaves is accurate.
It should be noted that while the present invention has been illustrated in the drawings and described in connection with the preferred embodiments thereof, it is to be understood that the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but are to be construed as providing a full breadth of the disclosure. The above-described features are further combined with each other to form various embodiments not listed above, and are considered to be the scope of the present invention described in the specification; further, modifications and variations of the present invention may be apparent to those skilled in the art in light of the foregoing teachings, and all such modifications and variations are intended to be included within the scope of this invention as defined in the appended claims.
Claims (10)
1. The method for measuring the content of tea polyphenol in tea leaves is characterized by comprising the following steps of:
(1) Pulverizing folium Camelliae sinensis raw materials, sieving with 40 mesh sieve, adding deionized water, leaching at 85-95deg.C, and filtering to obtain folium Camelliae sinensis leaching solution;
(2) Adding the porous cellulose microspheres loaded with aluminum ions into tea leaching solution, adjusting the pH to 6.0-6.5, and standing at 50-60 ℃ for 60-90min to obtain porous cellulose microspheres loaded with tea polyphenol salt;
(3) Treating the porous cellulose microspheres loaded with tea polyphenol salt obtained in the step (2) by dilute acid to dissolve the tea polyphenol salt and obtain tea polyphenol acidolysis solution;
(4) Adding ethyl acetate into the acidolysis solution of tea polyphenol for extraction to obtain an ethyl acetate phase;
(5) Concentrating ethyl acetate phase at 60deg.C under reduced pressure to obtain tea polyphenols mother liquor;
(6) Reacting the diluted solution of the tea polyphenol mother solution obtained in the step (5) with a Fu Lin Fen reagent, adding 7.5% Na 2CO3 solution, standing, measuring absorbance at 765nm, and calculating the tea polyphenol content according to the following formula:
；
In the method, in the process of the invention, The content of tea polyphenol is that A is the absorbance of a sample test solution, A 0 is the absorbance of a reagent blank solution, V is the volume of a tea polyphenol mother solution,As a dilution factor, the concentration of the organic solvent,Is the slope of the gallic acid standard curve,Is the dry matter content of the tea leaves,The quality of the tea is the quality of the tea.
2. The method of claim 1, wherein the aluminum ion loaded cellulose porous microspheres are prepared by: preparing a saturated aqueous solution of hydrated aluminum sulfate, adding cellulose porous microspheres, oscillating and activating at 75 ℃ for 30 min, filtering, washing and drying to obtain the product.
3. The method of claim 2, wherein the mass ratio of the hydrated aluminum sulfate to the cellulose porous microspheres is 1:5, and the amount of the hydrated aluminum sulfate is 30-50% of the weight of the tea leaf raw material.
4. The method of claim 1, wherein step (1) comprises adding 10-20 volumes of deionized water and leaching 2-3 times at 85-95 ℃.
5. The method of claim 1, wherein step (2) comprises pH adjustment using 10% sodium bicarbonate solution.
6. The method according to claim 1, wherein step (3) comprises treating with 2mol/L dilute sulfuric acid or 4mol/L hydrochloric acid for 30-60min under stirring.
7. The process according to claim 1, wherein in step (4), an equal volume or twice the volume of ethyl acetate is added to the acid solution of tea polyphenols.
8. The process according to claim 1, wherein the extraction in step (4) comprises 3 extractions at 40-50 ℃ for 20-30min each, followed by combining ethyl acetate phases.
9. A method according to claim 1, wherein the tea dry matter content is determined as follows: and (3) drying the tea sample at 120 ℃ for 1h, cooling to room temperature under the drying condition, weighing, and taking the ratio of the weight of the dried tea sample to the weight of the tea sample before drying as the dry matter content.
10. The method of claim 1, wherein the gallic acid standard curve is obtained by:
weighing 0.1100g of gallic acid, dissolving with a proper amount of water, transferring to a 100ml volumetric flask, fixing the volume to a scale mark with water, and shaking uniformly;
Respectively transferring 0.0 mL, 1.0mL, 2.0mL, 3.0mL, 4.0mL and 5.0mL of gallic acid standard stock solution into a 100mL volumetric flask, respectively fixing the volume to scale marks, and shaking uniformly to obtain gallic acid working solutions with the concentrations of 0, 10 mug/mL, 20 mug/mL, 30 mug/mL, 40 mug/mL and 50 mug/mL;
and (3) reacting the gallic acid working solution with a Fu Lin Fen reagent, adding a 7.5% Na 2CO3 solution, standing, measuring the absorbance at 765nm, and drawing a curve of absorbance and concentration to obtain the gallic acid standard curve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410560714.1A CN118130410B (en) | 2024-05-08 | 2024-05-08 | Method for measuring content of tea polyphenol in tea leaves |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410560714.1A CN118130410B (en) | 2024-05-08 | 2024-05-08 | Method for measuring content of tea polyphenol in tea leaves |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN118130410A CN118130410A (en) | 2024-06-04 |
| CN118130410B true CN118130410B (en) | 2024-06-28 |
Family
ID=91242059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410560714.1A Active CN118130410B (en) | 2024-05-08 | 2024-05-08 | Method for measuring content of tea polyphenol in tea leaves |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118130410B (en) |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6852289B2 (en) * | 1996-10-02 | 2005-02-08 | Saftest, Inc. | Methods and apparatus for determining analytes in various matrices |
| CN1370527A (en) * | 2001-02-21 | 2002-09-25 | 陈建操 | Toxoprotein, medicament for toxoprotein caused disease and the disease preventing and treating method |
| CN100490838C (en) * | 2005-04-30 | 2009-05-27 | 云南白药集团股份有限公司 | Medicinal active component of whiteflower wisteria root and its preparing process and quality control method |
| CN1939296B (en) * | 2005-09-29 | 2011-04-13 | 中国人民解放军军事医学科学院毒物药物研究所 | Theapolyphenol composition and its preparation |
| EP2196208A4 (en) * | 2007-09-26 | 2010-09-22 | Takasago Perfumery Co Ltd | Plant extract and use thereof |
| CN101343270B (en) * | 2008-09-04 | 2011-01-19 | 南昌航空大学 | Method for extracting tea polyphenol and theine from tea simultaneously |
| CN101961422B (en) * | 2009-07-24 | 2013-11-13 | 云南天士力帝泊洱生物茶集团有限公司 | Extractive of Pu'er tea and preparation method thereof |
| CN104458975B (en) * | 2014-11-26 | 2017-02-08 | 程金生 | Test method for detection of tea polyphenol and flavonoid constituents of golden camellia |
| CN105021608A (en) * | 2015-08-20 | 2015-11-04 | 昆明理工大学 | Kit for detecting total polyphenol content in beverage, preparation method of kit and method for detecting total polyphenol content in beverage using kit |
| CN105115967B (en) * | 2015-08-24 | 2017-12-05 | 重庆大学 | Load the functional fiber element film of zinc silicate microballoon and the method for detecting tannic acid |
| CN105220361A (en) * | 2015-11-04 | 2016-01-06 | 苏州大学 | The preparation method of a kind of Tea Polyphenols/cellulose acetate nano fibrous membrane |
| CN107321322B (en) * | 2017-08-16 | 2020-05-05 | 齐鲁工业大学 | Method for preparing tea polyphenol adsorbing material through cellulose modification |
| CN109342418A (en) * | 2018-12-07 | 2019-02-15 | 云南商测质量检验技术服务有限公司 | Peroxide value quick testing reagent and its application method in a kind of food |
| CN115184287A (en) * | 2022-07-11 | 2022-10-14 | 中南大学 | Nano material for detecting tea polyphenol and ascorbic acid by spectrophotometry |
| CN115433789A (en) * | 2022-07-22 | 2022-12-06 | 百草边大生物科技(青岛)有限公司 | Preparation method of macrobiological functional agent containing tea components |
| CN116735771B (en) * | 2023-08-08 | 2023-10-10 | 广东药科大学 | Targeted screening method for efficacy of aging Liupu tea extract in preventing and treating dampness-induced spleen and stomach syndrome |
| CN117330526A (en) * | 2023-10-19 | 2024-01-02 | 广西梧州茶厂有限公司 | Rapid detection method for tea polyphenol content in Liupu tea |
-
2024
- 2024-05-08 CN CN202410560714.1A patent/CN118130410B/en active Active
Non-Patent Citations (2)
| Title |
|---|
| 白果壳纤维素对不同种类多酚的吸附行为及其动力学研究;吴晶晶;食品与发酵工业;20220615(第11期);121-128 * |
| 碱处理强度对木质纤维素吸附茶儿茶素类和咖啡碱的影响;梁慧玲;张伟;王晶;;中国茶叶;20090715(第07期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN118130410A (en) | 2024-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110618211B (en) | Method for extracting scutellaria chemical components by using eutectic solvent | |
| CN105175379B (en) | A kind of extracting method of Flavonoid substances | |
| CN101921494B (en) | Preparation method of red pigment from camellia japonica | |
| CN108051520A (en) | A kind of method of aflatoxin B1 in detection tealeaves | |
| CN118130410B (en) | Method for measuring content of tea polyphenol in tea leaves | |
| Menis et al. | Colorimetric Determination of Palladium with α-Furildoxime | |
| CN113173902B (en) | Continuous production method of oligomeric proanthocyanidins with uniform polymerization degree | |
| CN107876048A (en) | A kind of photocatalyst preparation for effectively removing indoor decoration pollution | |
| CN112107604B (en) | Method for extracting sweet tea antioxidant polyphenol | |
| CN113713752B (en) | Micron flower-like bismuth oxide material, preparation method thereof and application thereof in adsorbing radioactive anions | |
| CN107540686A (en) | A kind of coumarin kind compound containing benzofuran ring, preparation method and applications | |
| JP2010523133A (en) | Extraction of theaflavin | |
| CN112370476A (en) | Method for purifying flavonoid compounds in folium artemisiae argyi | |
| CN111544494A (en) | HPEF extraction method of tea seed phenolic acid | |
| CN115844779B (en) | Total flavone and fruit acid part in citrus pulp, and preparation method and application thereof | |
| CN114469818B (en) | Quinoa extract, preparation method and application thereof, and extractant for extracting quinoa polyphenol | |
| CN112336665B (en) | Sambucus williamsii extract and preparation method thereof | |
| CN109824644B (en) | Method for directly extracting tectorigenin from pueraria lobata flower | |
| CN113777065B (en) | Rapid indirect detection method for glyphosate | |
| CN109541077B (en) | Method for measuring content of vitamin C in rose by using HPLC (high performance liquid chromatography) | |
| CN117503827A (en) | Preparation method of myrtle extract and myrtle extract | |
| CN112451599A (en) | Water-soluble grape seed extract and preparation method thereof | |
| CN118141723A (en) | Sambucus extract, preparation method thereof and cosmetics | |
| CN117159417A (en) | Method for preparing tricholoma matsutake extract with low arsenic content, extract and application thereof | |
| CN117815284A (en) | Sambucus williamsii hance extract and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |