Method for identifying Tieguanyin variety by combining high-resolution mass spectrum with linear discriminant analysis

Abstract

The invention belongs to the technical field of agricultural product variety identification, and particularly relates to a Tieguanyin variety identification method by combining high-resolution mass spectrometry with linear discriminant analysis. According to the method, 65 organic components in a tea leaf extracting solution are analyzed by adopting high-resolution mass spectrometry, characteristic components of the Tieguanyin variety are screened out by utilizing single-factor variance analysis, and a Tieguanyin variety discrimination model is established by combining linear discriminant analysis; the initial discrimination accuracy of the model reaches 99.0%, the cross validation accuracy is 97.1%, and the Tieguanyin variety can be effectively distinguished. The method provides important technical support for protection of the geographical indication product Anxi Tieguanyin, and has good practical application value.

Description

Technical Field

[0001] This invention belongs to the field of agricultural product variety identification technology, specifically relating to a method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis. Background Technology

[0002] Tieguanyin, originating from Anxi County, Fujian Province, is a historically renowned tea and a top-grade oolong tea from southern Fujian. In recent years, the Tieguanyin industry has experienced strong growth, with its products enjoying popularity among consumers both domestically and internationally, bringing significant economic benefits to the production area. Tieguanyin tea falls between green and black tea, belonging to the semi-fermented tea category. It possesses a unique "Guanyin rhyme," a delicate and elegant fragrance, with a natural orchid aroma after brewing. Its pure and rich taste, and lingering aroma, have earned it the reputation of "still fragrant after seven infusions." The national standard GB / T 19598-2025, "Quality Requirements for Geographical Indication Products: Anxi Tieguanyin," stipulates that only oolong tea with the quality characteristics of Tieguanyin, cultivated and harvested using Tieguanyin tea tree varieties under the natural environmental conditions within the geographical indication product's production area and processed according to unique traditional techniques, can be called Anxi Tieguanyin. However, there are many types of low-priced oolong tea on the market, and some oolong teas such as Jin Guanyin, Benshan, Huangjingu, and Maoxie are quite similar to Tieguanyin. Furthermore, these teas differ from Tieguanyin in economic value (by tens or even hundreds of times). These characteristics lead to the frequent occurrence of counterfeit Anxi Tieguanyin teas in the market. Therefore, the identification of Anxi Tieguanyin varieties becomes particularly important.

[0003] Methods for identifying tea varieties mainly involve analyzing characteristic components in tea using optical instruments such as near-infrared spectroscopy, combined with statistical analysis. Invention patent CN105181650A discloses a method for rapidly identifying tea varieties using near-infrared spectroscopy; invention patent CN118794917A utilizes an Antaris II Fourier transform near-infrared spectrometer to collect near-infrared diffuse reflectance spectral data of green tea samples, and uses a nonlinear feature extraction method to extract identification information of green tea varieties from the near-infrared spectral data, thus achieving tea variety identification; invention patent CN 119691515A discloses a method for accurately classifying and assessing tea by collecting visible-near-infrared spectral data of tea and using Teaformer for feature extraction and classification; however, infrared spectra are susceptible to environmental interference such as water molecules and baseline drift. Furthermore, invention patent CN119441924A discloses a machine learning method for classifying mulberry leaf tea varieties based on polyphenol components and mineral characteristics. Invention patent CN115308318A describes the analysis of metabolites in wild tea samples of Jianghua bitter tea using UPLC-Q-TOF / MS.

[0004] High-resolution mass spectrometry (HRMS) is a powerful analytical technique. The combination of high-performance liquid chromatography (UPLC) and HRMS significantly enhances the identification and characterization of compounds, and is widely used in the analysis of complex components. Invention patent CN113125589 B discloses an application of metabolomics analysis technology for identifying Ya Shi Xiang Dan Cong tea. However, there are no reports on the use of UPLC-HRMS for varietal identification of Anxi Tieguanyin Oolong tea. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a technical solution for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis. This invention utilizes UPLC-HRMS to analyze the characteristic components of Anxi Tieguanyin oolong tea, combined with statistical analysis methods, to achieve high-accuracy identification of Tieguanyin varieties, providing a technical method for the protection of Anxi Tieguanyin geographical indication products.

[0006] The present invention is implemented using the following technical solutions: This invention provides a method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis. The method employs UPLC-HRMS to analyze 65 organic components in the extract of Anxi Tieguanyin tea samples. Then, one-way ANOVA is used to screen for characteristic components of the Tieguanyin variety, including 13 amino acids, 7 organic acids, 26 glycosides, 7 polyphenols, 8 sugars, 2 anthocyanins, 1 alkaloid, and 1 tea pigment. A Tieguanyin variety discrimination model is then established using linear discriminant analysis. Finally, the Tieguanyin variety is identified using this discrimination model.

[0007] Furthermore, the Anxi Tieguanyin tea samples specifically include: representative Anxi Tieguanyin samples collected from the geographical indication protection area of ​​Anxi County, according to the administrative region specified in the national standard GB / T 19598-2025 "Quality Requirements for Geographical Indication Products: Anxi Tieguanyin"; and oolong tea samples prepared from Benshan and Maoxie varieties within Anxi County.

[0008] Furthermore, the UPLC-HRMS analysis conditions are as follows: Ultra-high performance liquid chromatography (UHPLC) conditions: Agilent Eclipse Plus C18 column, 100 mm × 2.1 mm, 1.8 μm; mobile phase A: methanol containing 0.1% formic acid and 1 mM ammonium formate; mobile phase B: 0.1% formic acid aqueous solution containing 1 mM ammonium formate; gradient elution program: 0–9 min, 5–45% A; 9–14 min, 45–95% A; 14–16 min, 95% A; 16–16.1 min, 95–5% A; 16.1–20 min, 5% A; column temperature: 45 °C; flow rate: 0.3 mL / min; injection volume: 1 μL.

[0009] High-resolution mass spectrometry conditions: flow rate 0.4 mL / min -1 Electrospray positive and negative ion modes were used respectively, with spray voltages of 3.5 kV(+) and 3.1 kV(-), atomizing gas pressure of 40 arb; drying gas was N2, pressure of 12 arb, drying gas temperature of 350℃; capillary temperature of 320℃, RF frequency of 50, and full scan mass-to-charge ratio range of 100~1200.

[0010] Furthermore, the characteristic components specifically include: leucine, γ-aminobutyric acid, serine, aspartic acid, asparagine, valine, proline, tryptophan, threonine, theanine, glutamine, folate (D-piperidin-2-carboxylic acid), lysine, theobromine, 1-caffeoylquinic acid, 1-p-coumaroylquinic acid, 4-caffeoylquinic acid, 4-p-coumaroylquinic acid, 5-caffeoylquinic acid, protocatechuic acid, gallic acid, delphinidin-3-O-glucoside, delphinidin-3-galactoside, and delphinidin-3-rutinoside. Benzyl alcohol-β-primrose glycoside, vitexin 2′-rhamnoside, isovitexin 2′-rhamnoside, isovitexin 2′-glucoside, dihydromyricetin, kaempferol-3-dicoumarin glucoside, kaempferol-3-O-[β-D-galactose-(1→4)][α-L-rhamnose-(1→6)]-β-D-glucoside, kaempferol-3-O-[β-D-glucoside-(1→4)][α-L-rhamnose-(1→6)]-β-D-glucoside, kaempferol-3-O-[β-D-glucoside-(1→4)][α-L-rhamnose-(1→6)]-β-D-glucoside, kaempferol-3-O-α-L-rhamnoside, kaempferol Kaempferol-3-O-galactoside, Kaempferol-3-O-rutinoside, Kaempferol-3-O-glucoside, Kaempferol-3-O-arabinoside, Kaempferol-7-O-rhamnoside, Kaempferol-3-O-glucorhamnoside, Myricetin-3-O-glucorhamnoside, Myricetin-3-O-glucorhamnoside, Myricetin-3-O-glucorhamnoside, Myricetin-3-O-glucorhamnoside, Quercetin-3-O-β-D-galactoside, Quercetin-3-O-β-D-glucoside, [unclear text - likely a continuation of the previous sentence] Cortin-3-O-glucuronide-rhamnogalactoside, rutin, theaflavins, catechins, epicatechin, epicatechin-3-O-(3''-O-methyl)gallate, epicatechin gallate, epigallocatechin 3-O-(3-O-methyl)gallate, epigallocatechin gallate, epigallocatechin gallate, SUGAR-2-O-β-D-arabinose-D-glucose, raffinose, mannitol, fructose, glucose, sucrose, arabinose, rhamnoose, proanthocyanidins B1 and B2.

[0011] Furthermore, the Tieguanyin variety discrimination model is specifically as follows: Tieguanyin = -62285.077 γ-aminobutyric acid + 1234.400 valine + 3275.189 benzyl alcohol-β-primrose glycoside + 3060.612 vitexin 2′-rhamnoside - 17439.883 kaempferol-3-dicoumarin glucoside - 1187.922 kaempferol-3-O-β-D-glucoside + 7543.663 kaempferol-3-O-galactoside + 9446.689 kaempferol-7-O-rhamnoside + 339.626 epicatechin - 253.700 epigallocatechin 3-O gallate + 18.726 fructose + 1018.166 sucrose - 177.515; Benshan = -8867.948 γ-aminobutyric acid + 2023.051 valine + 9164.133 benzyl alcohol-β-primrose glycoside + 1370.938 vitexin 2′-rhamnoside - 46923.519 kaempferol-3-dicoumarin glucoside - 2623.532 kaempferol-3-O-β-D-glucoside + 11395.565 kaempferol-3-O-galactoside + 18466.385 kaempferol-7-O-rhamnoside + 536.822 epicatechin - 755.270 epigallocatechin 3-O gallate ester - 2597.838 fructose + 1340.679 sucrose - 253.747; Hairy crab = -67117.098 γ-aminobutyric acid + 2153.499 valine + 7557.356 benzyl alcohol-β-primrose glycoside + 2852.163 vitexin 2′-rhamnoside - 66485.166 kaempferol-3-dicoumarin glucoside - 2838.843 kaempferol-3-O-β-D-glucoside + 12611.440 kaempferol-3-O-galactoside + 16852.677 kaempferol-7-O-rhamnoside + 424.640 epicatechin - 661.920 epigallocatechin 3-O gallate - 959.595 fructose + 1367.327 sucrose - 261.891.

[0012] Furthermore, the Tieguanyin variety discrimination model for identifying Tieguanyin varieties specifically involves: after high-resolution mass spectrometry analysis of an unknown variety of oolong tea sample, the peak area of ​​the characteristic peak is normalized and then input into the Tieguanyin variety discrimination model. The values ​​of the function equations for different varieties are compared, and the sample with the largest value belongs to the source variety represented by the equation.

[0013] The present invention has the following beneficial effects: This invention utilizes UPLC-HRMS to analyze 87 organic compounds in oolong tea samples prepared from Tieguanyin, Benshan, and Maoxie varieties. One-way ANOVA was used to screen out 65 organic compounds with significant differences. Further linear discriminant analysis was employed to effectively distinguish between the Tieguanyin, Benshan, and Maoxie varieties. The cross-validation accuracy rate was 97.1%, demonstrating significant practical application value and providing important support for the protection of Anxi Tieguanyin geographical indication products. Attached Figure Description

[0014] Figure 1 Total ion chromatogram of Anxi Tieguanyin tea extract in positive mode of high-resolution mass spectrometry; Figure 2 Total ion chromatogram of Anxi Tieguanyin tea extract in negative mode in high-resolution mass spectrometry; Figure 3 A comparison of the peak areas of the nine characteristic components in the classification function; Figure 4 The LDA discriminant function yields a scatter plot. Detailed Implementation

[0015] To better understand the method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with chemometrics, the following examples further illustrate the invention. However, the application of the invention is not limited to the specific examples below. Example 1:

[0016] (1) Collect representative tea samples from different varieties in Anxi County: According to the administrative area specified in the national standard GB / T 19598-2025 "Quality Requirements for Geographical Indication Products: Anxi Tieguanyin", a total of 87 representative Anxi Tieguanyin samples were collected from the geographical indication protection areas of Xiping Town, Longjuan Township, Xianghua Town, Gande Town, Taozhou Town, Jiandou Town, Huqiu Town, Daping Town, Changkeng Town, Jingu Town, and Guanqiao Town in Anxi County; in addition, 10 samples of oolong tea prepared from Benshan variety and 5 samples of oolong tea prepared from Maoxie variety were collected in Anxi County.

[0017] (2) Pretreatment of tea samples: Grind the sample collected in (1) into a uniform powder, accurately weigh 0.5000g of the sample into a 50 mL centrifuge tube, add 20 mL of 70% methanol extract, soak overnight, sonicate for 20 min, centrifuge to obtain the supernatant, and filter it for later use.

[0018] (3) Ultra-high performance liquid chromatography (UHPLC) conditions: Agilent Eclipse Plus C18 column (100 mm × 2.1 mm, 1.8 μm); mobile phase A was methanol containing 0.1% formic acid and 1 mM ammonium formate, and mobile phase B was 0.1% formic acid aqueous solution containing 1 mM ammonium formate. Gradient elution was performed with the following gradient elution program: 0–9 min, 5–45% A; 9–14 min, 45–95% A; 14–16 min, 95% A; 16–16.1 min, 95–5% A; 16.1–20 min, 5% A; column temperature 45℃; flow rate 0.3 mL / min; injection volume 1 μL.

[0019] (4) High-resolution mass spectrometry conditions: flow rate of 0.4 mL·min -1 Electrospray positive and negative ion modes were used respectively, with spray voltages of 3.5 kV(+) and 3.1 kV(-), and atomizing gas pressure of 40 arb; the drying gas was N2 with a pressure of 12 arb and a drying gas temperature of 350℃; the capillary temperature was 320 ℃, the RF frequency was 50, and the full scan mass-to-charge ratio range was 100~1200.

[0020] (5) The tea supernatant obtained in (2) was analyzed by high-resolution mass spectrometry in both positive and negative modes. The results are as follows: Figure 1 and Figure 2 As shown in the figure. Mass spectrometry data were analyzed using Compound Discoverer 3.1 software, and the precursor ions, fragment ions, and retention times were compared with those in the literature, with reference to the mzCloud, PubChem, and HMDB databases. 87 compounds were identified.

[0021] (6) Using one-way ANOVA, the contents of 87 compounds in different varieties (Tieguanyin, Benshan, and Maoxie) of oolong tea were compared, and 65 components with significant differences were screened out (p<0.05), as shown in Table 1. It can be seen that the contents of proline, tryptophan, theobromine, 1-caffeoylquinic acid, 4-caffeoylquinic acid, 5-caffeoylquinic acid, dihydromyricetin, kaempferol-3-dicoumarin glucoside, myricetin-3-O-glucoside, myricetin-3-O-glucorhamnoside, catechin, epicatechin-3-O-gallate, epicatechin gallate, epigallocatechin 3-O-gallate, epigallocatechin gallate, 2-O-β-D-arabinose-D-glucose, raffinose, and glucose in Tieguanyin tea were significantly higher than those in Benshan and Maoxie tea.

[0022] Table 1. Content (normalized) and p-values ​​of compounds showing significant differences in different varieties of oolong tea.

[0023] (7) Linear discriminant analysis Linear discriminant analysis was performed using SPSS software, and cross-validation (leave-one-out method) was used for validation. This method involves repeatedly selecting one distinct sample from the training set as the validation set, with the remaining samples used as the training set, until all samples are used as the validation set. Leave-one-out cross-validation assesses the model's generalization ability, avoids overfitting on the training data, and allows evaluation of the model's performance on unknown data using test data. Using 65 significantly different components as input, linear discriminant analysis was performed, yielding the Fisher linear discriminant function as follows: Tieguanyin = -62285.077 γ-aminobutyric acid + 1234.400 valine + 3275.189 benzyl alcohol-β-primrose glycoside + 3060.612 vitexin 2′-rhamnoside - 17439.883 kaempferol-3-dicoumarin glucoside - 1187.922 kaempferol-3-O-β-D-glucoside + 7543.663 kaempferol-3-O-galactoside + 9446.689 kaempferol-7-O-rhamnoside + 339.626 epicatechin - 253.700 epigallocatechin 3-O gallate + 18.726 fructose + 1018.166 sucrose - 177.515; Benshan = -8867.948 γ-aminobutyric acid + 2023.051 valine + 9164.133 benzyl alcohol-β-primrose glycoside + 1370.938 vitexin 2′-rhamnoside - 46923.519 kaempferol-3-dicoumarin glucoside - 2623.532 kaempferol-3-O-β-D-glucoside + 11395.565 kaempferol-3-O-galactoside + 18466.385 kaempferol-7-O-rhamnoside + 536.822 epicatechin - 755.270 epigallocatechin 3-O gallate ester - 2597.838 fructose + 1340.679 sucrose - 253.747; Hairy crab = -67117.098 γ-aminobutyric acid + 2153.499 valine + 7557.356 benzyl alcohol-β-primrose glycoside + 2852.163 vitexin 2′-rhamnoside - 66485.166 kaempferol-3-dicoumarin glucoside - 2838.843 kaempferol-3-O-β-D-glucoside + 12611.440 kaempferol-3-O-galactoside + 16852.677 kaempferol-7-O-rhamnoside + 424.640 epicatechin - 661.920 epigallocatechin 3-O gallate - 959.595 fructose + 1367.327 sucrose - 261.891.

[0024] The peak areas of the 12 compounds specified in the function are compared across the three varieties, as shown below. Figure 3As shown, the highest contents of kaempferol-3-dicoumarin glucoside and epigallocatechin 3-O-gallate were found in the Tieguanyin variety, while the highest contents of kaempferol-3-O-glucoside, kaempferol-3-O-galactoside, and epigallocatechin were found in the Benshan variety. The highest contents of γ-aminobutyric acid, fructose, and sucrose were found in the Maoxie variety. Significant differences were observed among the marker compounds of different varieties, indicating that these compounds can serve as characteristic markers for identifying Anxi Tieguanyin varieties.

[0025] The scores for function 1 and function 2 obtained from the discriminant analysis are plotted as follows: Figure 4 As shown, Tieguanyin, Benshan, and Maoxie varieties cluster into three categories, which can be easily distinguished. The discriminant function was used to classify the varieties of oolong tea samples, and the results are shown in Table 2. The table shows that the overall accuracy of the original prediction was 99.0%. Cross-validation results showed that 5 out of 102 samples were misclassified, resulting in an overall accurate discrimination rate of 97.1%.

[0026] Table 2. Classification results of linear discriminant analysis

[0027] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis, characterized in that, Sixty-five organic components in the extract of Anxi Tieguanyin tea samples were analyzed using UPLC-HRMS. One-way ANOVA was then used to screen characteristic components of the Tieguanyin variety, including 13 amino acids, 7 organic acids, 26 glycosides, 7 polyphenols, 8 sugars, 2 anthocyanins, 1 alkaloid, and 1 tea pigment. A Tieguanyin variety discrimination model was then established using linear discriminant analysis. Finally, the Tieguanyin variety was identified using this discrimination model.

2. The method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis as described in claim 1, characterized in that, The Anxi Tieguanyin tea samples were specifically collected from representative Anxi Tieguanyin samples within the geographical indication protection area of ​​Anxi County, according to the administrative region specified in the national standard GB / T 19598-2025 "Quality Requirements for Geographical Indication Products: Anxi Tieguanyin". Also, samples of oolong tea prepared from Benshan and Maoxie varieties in Anxi County were collected.

3. The method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis as described in claim 1, characterized in that, The UPLC-HRMS analysis conditions are as follows: Ultra-high performance liquid chromatography (UHPLC) conditions: Agilent Eclipse Plus C18 column, 100 mm × 2.1 mm, 1.8 μm; mobile phase A: methanol containing 0.1% formic acid and 1 mM ammonium formate; mobile phase B: 0.1% formic acid aqueous solution containing 1 mM ammonium formate; gradient elution program: 0–9 min, 5–45% A; 9–14 min, 45–95% A; 14–16 min, 95% A; 16–16.1 min, 95–5% A; 16.1–20 min, 5% A; column temperature: 45 °C; flow rate: 0.3 mL / min; injection volume: 1 μL; high-resolution mass spectrometry conditions: flow rate: 0.4 mL / min. -1 Electrospray positive and negative ion modes were used respectively, with spray voltages of 3.5 kV(+) and 3.1 kV(-), atomizing gas pressure of 40 arb; drying gas was N2, pressure of 12 arb, drying gas temperature of 350℃; capillary temperature of 320℃, RF frequency of 50, and full scan mass-to-charge ratio range of 100~1200.

4. The method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis as described in claim 1, characterized in that, The specific characteristic components include: leucine, γ-aminobutyric acid, serine, aspartic acid, asparagine, valine, proline, tryptophan, threonine, theanine, glutamine, folate (D-piperidin-2-carboxylic acid), lysine, theobromine, 1-caffeoylquinic acid, 1-p-coumarylquinic acid, 4-caffeoylquinic acid, 4-p-coumarylquinic acid, 5-caffeoylquinic acid, protocatechuic acid, gallic acid, delphinidin-3-O-glucoside, delphinidin-3-galactoside, delphinidin-3-rutinoside, and benzoic acid. Alcohol-β-primrose glycoside, vitexin 2′-rhamnoside, isovitexin 2′-rhamnoside, isovitexin 2′-glucoside, dihydromyricetin, kaempferol-3-dicoumarin glucoside, kaempferol-3-O-[β-D-galactose-(1→4)][α-L-rhamnosyl-(1→6)]-β-D-glucoside, kaempferol-3-O-[β-D-glucoside-(1→4)][α-L-rhamnosyl-(1→6)]-β-D-glucoside, kaempferol-3-O-[β-D-glucoside-(1→4)][α-L-rhamnosyl-(1→6)]-β-D-glucoside, kaempferol-3-O-α-L-rhamnoside, kaempferol- 3-O-galactoside, kaempferol-3-O-rutinoside, kaempferol-3-O-glucoside, kaempferol-3-O-arabinoside, kaempferol-7-O-rhamnoside, kaempferol-3-O-glucorhamnoside, myricetin-3-O-glucorhamnoside, myricetin-3-O-glucorhamnoside, myricetin-3-O-glucorhamnoside, myricetin-3-O-glucorhamnoside, quercetin-3-O-β-D-galactoside, quercetin-3-O-β-D-glucoside, quercetin Epigallocatechin-3-O-glucuronide-rhamnogalactoside, rutin, theaflavins, catechins, epicatechin, epicatechin-3-O-(3''-O-methyl)gallate, epicatechin gallate, epigallocatechin 3-O-(3-O-methyl)gallate, epigallocatechin gallate, epigallocatechin gallate, SUGAR-2-O-β-D-arabinose-D-glucose, raffinose, mannitol, fructose, glucose, sucrose, arabinose, rhamnoose, proanthocyanidins B1 and proanthocyanidins B2.

5. The method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis as described in claim 1, characterized in that, The Tieguanyin variety discrimination model is as follows: Tieguanyin = -62285.077 γ-aminobutyric acid + 1234.400 valine + 3275.189 benzyl alcohol-β-primrose glycoside + 3060.612 vitexin 2′-rhamnoside - 17439.883 kaempferol-3-dicoumarin glucoside - 1187.922 kaempferol-3-O-β-D-glucoside + 7543.663 kaempferol-3-O-galactoside + 9446.689 kaempferol-7-O-rhamnoside + 339.626 epicatechin - 253.700 epigallocatechin 3-O gallate + 18.726 fructose + 1018.166 sucrose - 177.515; Benshan = -8867.948 γ-aminobutyric acid + 2023.051 valine + 9164.133 benzyl alcohol-β-primrose glycoside + 1370.938 vitexin 2′-rhamnoside - 46923.519 kaempferol-3-dicoumarin glucoside - 2623.532 kaempferol-3-O-β-D-glucoside + 11395.565 kaempferol-3-O-galactoside + 18466.385 kaempferol-7-O-rhamnoside + 536.822 epicatechin - 755.270 epigallocatechin 3-O gallate ester - 2597.838 fructose + 1340.679 sucrose - 253.747; Hairy crab = -67117.098 γ-aminobutyric acid + 2153.499 valine + 7557.356 benzyl alcohol-β-primrose glycoside + 2852.163 vitexin 2′-rhamnoside - 66485.166 kaempferol-3-dicoumarin glucoside - 2838.843 kaempferol-3-O-β-D-glucoside + 12611.440 kaempferol-3-O-galactoside + 16852.677 kaempferol-7-O-rhamnoside + 424.640 epicatechin - 661.920 epigallocatechin 3-O gallate - 959.595 fructose + 1367.327 sucrose - 261.

891.

6. A method for identifying Tieguanyin tea varieties using high-resolution mass spectrometry combined with linear discriminant analysis as described in claim 1 or 5, characterized in that, The Tieguanyin variety discrimination model for identifying Tieguanyin varieties specifically involves: after high-resolution mass spectrometry analysis of an unknown variety of oolong tea sample, the peak area of ​​the characteristic peak is normalized and then input into the Tieguanyin variety discrimination model. The values ​​of the function equations for different varieties are compared, and the sample with the largest value belongs to the source variety represented by the equation.

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