CN115326944B

CN115326944B - Method for distinguishing different producing areas of radix aconiti kusnezoffii She Shancong

Info

Publication number: CN115326944B
Application number: CN202210648573.XA
Authority: CN
Inventors: 郑鹏; 刘少群; 孙彬妹; 李安生; 陈沛芬; 蔡嘉荣; 廖金梅
Original assignee: South China Agricultural University
Current assignee: South China Agricultural University
Priority date: 2022-06-09
Filing date: 2022-06-09
Publication date: 2023-09-26
Anticipated expiration: 2042-06-09
Also published as: CN115326944A

Abstract

The application relates to the technical field of tea quality evaluation, in particular to a distinguishing method of different producing areas of Wu She Shancong, wherein the distinguishing method is used for distinguishing Wu She Shancong in Fujia county from Wu She Shancong in Chaozhou, wu She Shancong in Chengzhou county is marked as MW, wu She Shancong in Chaozhou is marked as CW, MW and CW are distinguished by comparing the content of volatile aroma substances between MW and CW, wherein the volatile aroma substances comprise benzyl alcohol, the content of the benzyl alcohol of MW is higher than that of the benzyl alcohol of CW, the distinguishing method of the different producing areas of Wu She Shancong is used for screening out benzyl alcohol as distinguishing marks, and the distinguishing method can be used for distinguishing between Wu She Shancong in Chengjia county and Wu She Shancong in Chaozhou with physicochemical indexes, and has the advantage of high distinguishing accuracy.

Description

Method for distinguishing different producing areas of radix aconiti kusnezoffii She Shancong

Technical Field

The application relates to the technical field of tea quality evaluation, in particular to a method for distinguishing different places of origin of Wu She Shancong.

Background

Oolong tea from different producing areas often exhibits different tea leaf appearance and flavor characteristics due to differences in tea tree varieties, tea tree growth environments, processing and manufacturing processes and other factors. The phoenix single cluster, which originates in the town of the phoenix in the tidal region, is an excellent group of tea tree varieties in the oolong class, including more than 80 lines (strains). As the natural fragrance of different single plants is similar to various flower fragrances, at present, various varieties of phoenix single clusters are classified into ten large fragrance types according to fragrance types. Wherein Wu Sheshan is a sexual variety of the phoenix single tea, and has high yield, strong adaptability, good resistance, and natural fragrance of yellow cape jasmine and fresh taste after being brewed by the tea made of Wu Sheshan.

Currently, the black-bone She Shancong, originally produced from Chaozhou, has entered the county of ink-depletion and rooted and germinated in the county of ink-depletion. However, at present, the physical and chemical quality difference between the black-bone She Shancong planted in the ink county and the black-bone She Shancong planted in the Chaozhou city is only distinguished by artificial sense, so that the quality difference of Wu Sheshan clusters is larger. Therefore, there is a need to propose a black-bone She Shancong that objectively distinguishes the Chaozhou city from the Fu De county with physicochemical indexes.

Disclosure of Invention

The application aims to provide a distinguishing method of different producing areas of the black-bone She Shancong, wherein benzyl alcohol is screened out as a distinguishing mark by the distinguishing method of the different producing areas of the black-bone She Shancong, and black-bone She Shancong in Fujia county and black-bone She Shancong in Chaozhou city can be distinguished by physical and chemical indexes, so that the distinguishing method has the advantage of high distinguishing accuracy.

The application aims to provide a distinguishing method of different places of origin of Wu She Shancong.

In order to achieve the above purpose, the present application provides the following technical solutions:

a method for distinguishing between different producing areas of black She Shancong is provided, wherein black She Shancong in the county of ink depletion and black She Shancong in the city of hectorite are distinguished, black She Shancong in the county of ink depletion is marked as MW, black She Shancong in the city of hectorite is marked as CW, and MW and CW are distinguished by comparing the content of volatile aroma substances between MW and CW, wherein the volatile aroma substances comprise benzyl alcohol, and the content of benzyl alcohol of MW is higher than that of CW.

In some embodiments, the volatile aroma further comprises dehydrolinalool, nerol, and alpha-farnesene, the MW dehydrolinalool content is higher than the CW dehydrolinalool content, the MW nerolidol content is lower than the CW nerolidol content, and the MW alpha-farnesene content is lower than the CW alpha-farnesene content.

In some embodiments, the content of the volatile aroma is obtained by: the method comprises the steps of extracting volatile aroma substances in tea leaves by a headspace solid-phase microextraction technology HS-SPME, and analyzing the volatile aroma substances by using gas chromatography-mass spectrometry GC-MS to obtain the content of the volatile aroma substances.

In some embodiments, MW and CW are also distinguished by comparing the content of inclusion substances between MW and CW, wherein the inclusion substances include one or more of water extract, free amino acids, caffeine, tea polyphenols, or catechins;

wherein the water extract content of MW is higher than that of CW, the free amino acid content of MW is extremely higher than that of CW, the caffeine content of MW is lower than that of CW, the tea polyphenol content of MW is higher than that of CW, the catechin EGCG, catechin EGC, catechin ECG, catechin C content of MW are all higher than that of CW, catechin EGCG, catechin EGC, catechin ECG, catechin C content of MW are lower than that of CW.

In some embodiments, the aqueous extract content is determined according to national standard GB/T8305-2013.

In some embodiments, the content of free amino acids is determined according to national standard GB/T8314-2013.

In some embodiments, the amount of caffeine is determined according to national standard GB/T8312-2013.

In some embodiments, the catechin content is determined according to national standard GB/T8313-2018.

The distinguishing method of the different-origin black-bone She Shancong has the beneficial effects that:

according to the characteristic that the temperature difference of the different producing areas of the black-bone She Shancong is larger than that of the Chaozhou city, and the characteristic that the content of benzyl alcohol in tea trees is higher and the benzyl alcohol is the precursor of tea aroma substances in the form of glucoside is utilized, the method judges that the environmental conditions of the Chaozhou county are more favorable for accumulation of benzyl alcohol glucoside in tea trees through finding the characteristics, selects benzyl alcohol as a distinguishing mark, and distinguishes MW and CW through comparing the content of benzyl alcohol (CW) between the black-bone She Shancong (MW) of the Chaozhou county and the black-bone She Shancong of the Chaozhou city, namely, the benzyl alcohol content of MW is higher than that of the CW, so that MW and CW are distinguished, and MW and CW can be distinguished quickly, accurately and efficiently, and consumers can purchase MW more positively.

Drawings

Fig. 1 is a PCA analysis of MW and CW electronic nose data of the examples.

Figure 2 is a graph of 20 of the MW and CW of the examples with significant differences in the common volatile aroma.

Fig. 3 shows PCA principal component analysis of volatile aroma in the example.

Figure 4 is the corresponding water extract content for MW and CW for the examples.

Figure 5 is the free amino acid content corresponding to MW and CW for the examples.

Fig. 6 is the caffeine content corresponding to MW and CW of the examples.

Figure 7 is the corresponding tea polyphenol content for MW and CW for the examples.

Figure 8 shows the corresponding catechin contents for MW and CW of the examples.

Detailed Description

Preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present application are shown in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Plant material and agent

The following examples were produced using black She Shancong samples, respectively grown in Chaozhou city and Fujia, wherein Chaozhou city black She Shancong was marked CW, fujia Wu Sheshan was marked MW, wu Sheshan clumps, 3-4 years old, 2021 spring, fresh leaves were picked according to the standard of one bud and two leaves, and processed according to the same oolong production flow. The tea sample is prepared from fresh tea leaves obtained by picking tea-making master with abundant experiences from Chaozhou Tianxia tea industry Co., ltd, and by conventional preparation process including sun-drying, green-making, de-enzyming, rolling and drying. CW is produced in Fenghun village (116.70468738 degrees 23.93572818 degrees) in Fenghun Zhenfengxi, chaozhou, the altitude of the place is about 600m, and the place belongs to subtropical monsoon climate, the annual average temperature is 18 ℃, and annual precipitation is about 2200 mm; MW is produced in De-county Dexing county (95.30721715 degrees, 29.32655767 degrees) in Linzhi city, the altitude of the land is about 850m, cloud and fog are around, rainwater is abundant, the land belongs to a subtropical humid climate zone on the mountain side of Himalaya, the annual average temperature is 13 ℃, the annual average time is 340 days in the frost-free period, and the annual average precipitation is 1900-2100 mm.

The tea leaf samples were ground to a powder and passed through a 60 mesh screen, and the sample powder was stored in a cool dry place at room temperature for use. All experimental analyses were performed in 3 biological replicates to ensure accuracy and minimize error.

Example 1

Fig. 1 (83.99% on the abscissa PC1 and 13.05% on the ordinate PC 2) shows the result of PCA analysis of the experimental data of the electronic nose. The analysis results of the two axes were 83.99% of PC1 and 13.05% of PC2, respectively. In the PCA comprehensive analysis result of the experimental data of the electronic nose, the analysis results of MW and CW cannot be well separated, and certain cross overlap exists between samples. Therefore, the aroma similarity of the two tea samples is high, and the two tea samples cannot be well distinguished by the electronic nose. More experimental data, such as more comparative test data from tea samples from different venues, is required to support the detection of data via the electronic nose to distinguish between tea samples from different venues.

In view of the above problems, the present example obtains benzyl alcohol as a significant marker for distinguishing MW and CW by analyzing the common aroma of MW and CW, and the principal component analysis of the MW and CW aroma data. Thus, MW is distinguished from CW by comparing the benzyl alcohol content of volatile aroma between MW and CW, wherein the benzyl alcohol content of MW is higher than CW.

The following are the steps of screening out benzyl alcohol, having:

MW and CW Co-aroma analysis

Of the 45 fragrances screened, 40 were common to both MW and CW. Of the common components, 10 species of benzyl alcohol, 1,3,5, 7-cyclooctatetraene, α -farnesene, α -ionone, α -pinene, linalool, phenylacetaldehyde, caryophyllene, nerolidol, P-xylene were very different at P <0.01 level, while 10 species of β -myrcene, (E) - β -farnesene, (Z) -jasmone, indole, trans- β -ionone, styrene, D-limonene, β -ocimene, ethyl acetate, 2-acetylpyrrole were significantly different at P < 0.05 level, as shown in fig. 2 (relative amounts on the ordinate are expressed as peak area±sd, n=3, i.e. experiments were performed three biological replicates). Among the substances showing the difference in content, there are 3 kinds of alcohol substances, 9 kinds of olefin substances, 1 kind of aldehyde substances, 3 kinds of ketone substances, 1 kind of ester substances and 3 kinds of other compounds. The different substances of the black-bone She Shancong in different cultivation areas are mainly concentrated on the olefin substances. The MW was higher than CW in the content of 6 aroma substances. Among them, benzyl alcohol, phenylacetaldehyde and (Z) -jasmone provide sweet and floral odors, while α -pinene and β -caryophyllene are woody odors. In the oolong processing process, the contents of the alpha-farnesene, the nerolidol, the indole and the benzyl alcohol are obviously increased along with the increase of the rocking degree, and the contents of the alpha-farnesene, the nerolidol and the indole in the analysis show the same change trend. Benzyl alcohol is a precursor of tea aroma substances, exists in the form of glucoside, is hydrolyzed under the action of acidity or enzyme to generate aroma compounds, and therefore, the environment conditions of Fuji county are favorable for accumulation of benzyl alcohol glucoside in tea trees, and the benzyl alcohol is used as a distinguishing mark, so that the method has enough scientific basis and can be popularized and applied to distinguishing MW from CW.

PCA analysis of MW and CW fragrance data

FIG. 3 shows (each dot in the figure represents a volatile material, e.g., 1 dehydrolinalool, 2 benzyl alcohol, 3 nerolidol, 4 alpha-farnesene, 5 1,3,5,7 cyclooctatetraene, 6 linalool, 7 beta-ocimene, 8 myrcene, 9 indole, 10 linalool oxide III), and black She Shancong fragrance was not greatly different in the different implanted regions by PCA analysis of MW and CW fragrance data. The analysis results for the two axes were 91.99% for PC1 and 8.01% for PC2, respectively. In specific aroma results, the characteristic aroma substances of CW are terpenes such as nerolidol, alpha-farnesene, linalool, etc. The characteristic aroma of MW is dehydrolinalool and benzyl alcohol. The aroma provided by dehydrolinalool is one of the main sources of floral and fruity aroma in single-cluster tea and is also a key compound for distinguishing tea leaves with different aroma types. In the results of the analysis, dehydrolinalool is also considered a key compound to distinguish between tea samples in different areas. The benzyl alcohol content showed very significant differences in tea samples in different regions, so that MW and CW tea samples could be visually distinguished by differences in benzyl alcohol content. But involves distinguishing, identifying more black She Shancong tea samples planted in different areas, more experimental data support is required.

It follows that MW is distinguished from CW by comparing the levels of volatile aroma between MW and CW, wherein the volatile aroma comprises benzyl alcohol, the benzyl alcohol level of MW being higher than the benzyl alcohol level of CW; further preferably, the volatile aroma further comprises dehydrolinalool, nerol and alpha-farnesene, the MW dehydrolinalool content being higher than CW dehydrolinalool content, the MW nerolidol content being lower than CW nerolidol content, the MW alpha-farnesene content being lower than CW alpha-farnesene content.

Example 2

For ease of understanding, one example of determining the volatile aroma of example 1 is provided below for illustration.

In this example, volatile substances in tea were measured by an internal standard method. 10ul of the internal standard solution was added to 2g of tea leaves and subjected to headspace solid phase microextraction (headspace-solidphase micro extraction, HS-SPME). The preparation method of the internal standard solution comprises the steps of adding 1uL of ethyl decanoate into 999uL of dichloromethane to prepare a diluent, diluting 10uL of the diluent to 1mL of dichloromethane to obtain an internal standard solution with the concentration of 8.64ug/mL, and storing the internal standard solution at the temperature of 4 ℃ for later use. 2g of tea leaves and 10ul of internal standard solution were added to a 40mL headspace bottle (Agilent Technologies, inc., paloAlto, CA, USA), the mouth of the bottle was quickly wrapped with tinfoil and sealed with tape, placed in a constant temperature metal bath with a 50mL centrifuge tube module, DVB/CAR/PDMS fibers (50/30 μm,2cm long) (Supelco) were inserted, exposed to the headspace above the tea sample, and extracted at 80℃for 40min. And then feeding in a non-split mode, wherein the temperature of the feeding inlet is 250 ℃, and the fiber is left at the feeding inlet for 3min to ensure complete desorption.

Gas chromatography-mass spectrometry (GC-MS) analysis was performed using an Agilent 1890B gas chromatograph (Agilent, santa Clara, CA, USA) coupled with a 5977A mass spectrum. A HP-5MS capillary column (30 m multiplied by 0.25mm multiplied by 0.25 um) is used, the carrier gas is high purity helium gas, the flow rate is 1.0mL/min, and the mode is not split. The initial oven temperature was maintained at 50deg.C for 1min, then raised to 220deg.C at a ramp rate of 5deg.C/min for 5min. The mass spectrometry ion source temperature and electron energy were set to 230 ℃ and 70eV, respectively. The scanning range was 30-400 atomic mass units (amu) and the solvent delay time was 4min.

Example 3

It is to be understood that the following description is provided for another embodiment of the distinguishing method of different producing areas of the black-bone She Shancong, and in practical application, the content of the main content substances in the tea is measured and the difference significance analysis is performed on the content. The content of five catechin monomers, namely water extract content, caffeine content, total free amino acid content, tea polyphenol content, catechin EC, catechin ECG, catechin EGC, catechin EGCG and catechin C, in the tea sample is mainly measured.

The detection results show that caffeine, total free amino acids, tea polyphenols, catechin ECG, catechin EGC, catechin EGCG showed very significant differences at P <0.0001 level, water extract and C showed very significant differences at P <0.01 level, and catechin EC did not show significant differences. Overall, the content of other inclusion substances except EC were all different to very significant levels (P < 0.01).

The analysis of caffeine, total free amino acids, tea polyphenols, catechins between MW and CW is as follows:

1 Water extract difference

Aqueous extract refers to the total amount of soluble material that can be leached by hot water. The content of the water extract reflects the quantity of soluble substances in the tea, and marks the thickness degree and the intensity degree of the taste of the tea soup, thereby reflecting the quality of the tea to a certain extent.

The water content of MW was 5.8%, dry matter content 94.2% and water extract content 55.1% as measured in this example; the CW water content was 3.0%, the dry matter content was 97.0% and the water extract content was 50.8%. As shown in FIG. 4, the MW water extract content was very significant (P < 0.01) higher than CW.

2 free amino acid differences

The content of amino acid, which is an important precursor substance formed by aroma substances and taste substances in tea, has an important influence on the quality of the tea. As shown in fig. 3 (n=3, i.e. experiments were performed in triplicate), the total free amino acid content of MW was 4.2% and the total free amino acid content of CW was 3.3%. The total free amino acid content of MW is very significant (P < 0.01) above CW.

The high MW amino acid content in the experimental results probably means that the suitability of tea plants grown in ink-removed to make different tea classes provides more possibilities.

3 caffeine difference

Caffeine is one of the main contributors to tea bitter taste, and EGCG has a bitter taste characteristic, but the degree of bitter taste of EGCG is about one half that of caffeine. Thus, CW is more bitter than MW in the presentation of taste. As shown in fig. 6 (relative content on the ordinate is expressed as peak area±sd. N=3, i.e. experiments were performed in three biological replicates), the caffeine content of MW was 102.3mg/g and the caffeine content of CW was 143.5mg/g. The caffeine content of MW is very significantly (P < 0.01) lower than that of CW, about 2/3 of CW.

4 tea polyphenols and catechins differences

As shown in fig. 7 (n=3, i.e. three biological replicates of the experiment), in MW shown in fig. 8, the total amount of tea polyphenols and the catechin catechins EGCG, catechin EGC, catechin ECG, catechin C content were all significantly higher than CW, no significant differences were shown in EC content in the two-place tea samples.

Wherein the total amount of MW and CW tea polyphenol substances is 38.63% and 30.03%, respectively, and the total amount of MW tea polyphenol substances is extremely significantly higher than (P < 0.01) CW; the EGCG content of MW and CW are 101.8mg/g and 79.21mg/g respectively, and the EGCG content of MW is extremely higher than (P < 0.01) CW; the MW and CW EGC content are 19.38mg/g and 13.09 mg/g respectively, the MW EGC content is extremely higher than (P < 0.01) CW; ECG contents of MW and CW are 30.92mg/g and 17.27mg/g, respectively, and the ECG content of MW is extremely significantly higher than (P < 0.01) CW; the C content of MW and CW is 4.725mg/g and 1.799mg/g respectively, the C content of MW is extremely higher than (P < 0.01) CW; the EC content of MW and CW were 4.961mg/g and 5.337mg/g, respectively, with no significant difference in MW and CW EC content.

In summary, MW and CW can also be distinguished by comparing the content of inclusion substances between MW and CW, wherein the inclusion substances include one or more of water extract, free amino acids, caffeine, tea polyphenols or catechins; the water extract content of MW is extremely higher than that of CW, the free amino acid content of MW is extremely higher than that of CW, the caffeine content of MW is lower than that of CW, the tea polyphenol content of MW is higher than that of CW, the catechin EGCG, catechin EGC, catechin ECG, catechin C content of MW are all higher than that of CW catechin EGCG, catechin EGC, catechin ECG, catechin C content of MW are lower than that of CW.

Example 4

It will be appreciated that the following provides an example of determining the content of the main content of the tea leaves of example 3.

Standard and reagent

The standards used in this example were purchased from the following companies. Ethyl decanoate (DecanoicAcid Ethyl Ester), catechin (Catechin, C), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (Epicatechin gallate, ECG), epigallocatechin gallate (Epigallocatechin gallate, EGCG), formic acid (FormicAcid, FA), dichloromethane (DCM), and Gallic Acid (GA) were purchased from Shanghai source leaf biotechnology limited. Caffeine (Caffeine) was purchased from the Beijing northern Weiindustrial metering technology institute. HPLC grade Acetonitrile (Acetonitrile) and Methanol (Methanol) were purchased from siegbai chemical (shanghai) limited. Normal alkane standard solution C for calculating linear Retention Index (RI) ₈ -C ₄₀ Purchased from beijing altar ink quality inspection technologies. Internal standard (Internal standard, IS) ethyl decanoate and prior to useMethyl chloride was diluted to the appropriate concentration. Ultrapure water was used in all experiments requiring water and was prepared from zemoer feier Germany (Thermo Fisher Scientific, germany) Barnstead GenPure Pro.

1 determination of tea Water extract content

The content of the water extract of the tea is measured according to the national standard GB/T8305-2013.

2 determination of total free amino acid content of tea

The total free amino acid content of the tea is determined according to the national standard GB/T8314-2013.

3 determination of caffeine content in tea

The caffeine content of tea is determined by high performance liquid chromatography (High Performance Liquid Chromatography, HPLC) based on national standard GB/T8312-2013.

4 determination of tea polyphenols and catechin content

The content of tea polyphenols in tea is measured by ferrous tartrate method. The ferrous tartrate solution was prepared by weighing 1.0g of ferrous sulfate (FeSO ₄ ·7H ₂ O) and 5.0g of potassium sodium tartrate (C) ₁₄ H ₄ O ₆ KNa·4H ₂ O), dissolved with water and fixed to a volume of 1L. 3.0g (accurate to 0.001 g) of the ground tea sample was weighed into a 500mL Erlenmeyer flask, 450mL of boiling distilled water was added, immediately transferred into a boiling water bath, leached for 45min, and shaken every 10 min. Filtering under reduced pressure immediately after leaching, transferring the filtrate into a 500mL volumetric flask, washing the residue with a small amount of distilled water for 2-3 times, filtering the filtrate into the volumetric flask, cooling, and diluting with distilled water to scale. Accurately sucking 1mL of the test solution, injecting into a 25mL volumetric flask, adding 4mL of water and 5mL of ferrous tartrate solution, fully mixing, adding pH7.5 phosphate buffer solution to the scale, using a 10mm cuvette, taking a reagent blank solution as a reference at the wavelength of 540nm, and measuring the absorbance (A). The content of tea polyphenol in the tea leaves is expressed in terms of dry mass fraction and is calculated according to the formula (1):

wherein L is ₁ The total amount of the test solution is in units of mL; l (L) ₂ The unit of the liquid consumption is mL; m is M ₀ The mass of the sample is expressed in g; m is the dry matter content of the sample in units; a is the absorbance of the sample.

The content of catechin in tea is measured according to national standard GB/T8313-2018 by High Performance Liquid Chromatography (HPLC). Adding 0.2g tea powder and 8mL70% methanol into a 10mL centrifuge tube, shaking the centrifuge tube manually for 3min, mixing, extracting in an ultrasonic cleaner (Ningbo new Zhi Biotechnology Co., ltd.) for 30 min, transferring 2mL supernatant into a 2mL centrifuge tube, centrifuging at 10000rpm for 3min, sucking 1mL supernatant with a pipette, and filtering into a 2mL brown sample bottle via a 0.22um membrane filter (available from Tianjin laboratory equipment Co., ltd.) for use. High performance liquid chromatography was performed using Alliance E2695 coupled to a 2489UV/Visible detector (Waters, taunton, massachusetts, USA). SunFire C18 column was used in this test5 μm,4.6mm x 250mm, 1/pk), column temperature 25.+ -. 5 ℃. When detecting the sample, the UV wavelength was set to 280nm. In the mobile phase setup, 0.1% formic acid was used for phase a and 100% acetonitrile was used for phase B. The catechin monomers were separated by gradient elution method as shown in table 1. The quantitative method of each component was calculated using the ratio of the peak area of each compound to the peak area of the internal standard (ethyl decanoate).

TABLE 1 gradient elution procedure parameters

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present application, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present application; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present application.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A distinguishing method of different producing areas 'Wu Sheshan clusters' is characterized by comprising the following steps: distinguishing 'Wu Sheshan cluster' of the ink county of the Tibetan autonomous region of China from 'Wu Sheshan cluster' of the ink county of the tidal state of China, marking the Wu She Shancong of the ink county of the Tibetan autonomous region of China as MW, marking the Wu Sheshan cluster of the tidal state of China as CW, and distinguishing MW from CW by comparing the content of volatile aroma substances between MW and CW, wherein the volatile aroma substances comprise benzyl alcohol, and the benzyl alcohol content of MW is higher than that of CW;

the volatile substances in the tea are measured by adopting an internal standard method, 10uL of internal standard liquid is added into 2g of tea, headspace solid-phase microextraction is carried out, the internal standard liquid is prepared by adding 1uL of ethyl decanoate into 999uL of dichloromethane to prepare a diluent, then diluting 10uL of the diluent into 1mL by using dichloromethane to obtain an internal standard solution with the concentration of 8.64ug/mL, storing the internal standard solution at 4 ℃ for standby, adding 2g of tea and 10uL of internal standard liquid into a 40mL headspace bottle, rapidly wrapping a bottle mouth by tinfoil and sealing by using adhesive tape, putting the bottle mouth into a constant-temperature metal bath with a 50mL centrifuge tube module, inserting DVB/CAR/PDMS fibers, exposing the bottle mouth to the headspace above a tea sample, extracting the bottle at 80 ℃ for 40min, then sampling the sample at the sample inlet temperature of 250 ℃ in a non-split mode, and leaving the fibers at the sample inlet for 3min.

2. The method for distinguishing different producing areas 'Wu Sheshan clusters' according to claim 1, wherein: the volatile aroma further comprises dehydrolinalool, nerol and alpha-farnesene, the MW dehydrolinalool content is higher than CW dehydrolinalool content, the MW nerolidol content is lower than CW nerolidol content, and the MW alpha-farnesene content is lower than CW alpha-farnesene content.

3. The method for distinguishing different producing areas 'Wu Sheshan clusters' according to claim 2, wherein: the content of the volatile aroma is obtained by: the method comprises the steps of extracting volatile aroma substances in tea leaves by a headspace solid-phase microextraction technology HS-SPME, and analyzing the volatile aroma substances by using gas chromatography-mass spectrometry GC-MS to obtain the content of the volatile aroma substances.

4. The method for distinguishing different producing areas 'Wu Sheshan clusters' according to claim 1, wherein: distinguishing MW from CW by also comparing the content of inclusion substances between MW and CW, wherein the inclusion substances include one or more of water extract, free amino acids, caffeine, tea polyphenols or catechins;

5. The method for distinguishing between different producing areas 'Wu Sheshan clusters' according to claim 4, wherein: the content of the water extract is measured according to the national standard GB/T8305-2013.

6. The method for distinguishing between different producing areas 'Wu Sheshan clusters' according to claim 4, wherein: the content of the free amino acid is measured according to the national standard GB/T8314-2013 of China.

7. The method for distinguishing between different producing areas 'Wu Sheshan clusters' according to claim 4, wherein: the content of the caffeine is measured according to Chinese national standard GB/T8312-2013.

8. The method for distinguishing between different producing areas 'Wu Sheshan clusters' according to claim 4, wherein: the content of catechin is determined according to national standard GB/T8313-2018.