A method for judging the processing degree of carbon-fried gardenia based on headspace-GC-IMS differential volatile components

Abstract

The present invention discloses a method for judging the processing degree of carbonized gardenia fruit based on headspace-GC-IMS differential volatile components, belonging to the technical field of analysis and identification of traditional Chinese medicine decoction pieces. The method comprises the following steps: powder the carbonized gardenia fruit to be tested, place it in a headspace sampling bottle, incubate, inject the sample, and obtain a fingerprint spectrum through GC-IMS detection; analyze the fingerprint spectrum to determine the characteristic volatile components and non-characteristic volatile components of the carbonized gardenia fruit to be tested; judge the processing degree of the carbonized gardenia fruit to be tested according to the peak intensity ratio of the characteristic volatile components and non-characteristic volatile components. The method provided by the present invention can be judged quickly and non-destructively, without complex sample pretreatment, the method is simple and environmentally friendly, the detection cost is low, the result is intuitive, and it is suitable for batch rapid, objective and accurate judgment of the processing degree of carbonized gardenia fruit, and can provide key data support for quality control in the production process.

Description

Technical Field

[0001] The present invention relates to the technical field of analysis and identification of traditional Chinese medicine decoction pieces, and particularly to a method for judging the processing degree of carbonized Gardenia jasminoides based on headspace-GC-IMS differential volatile components. Background Art

[0002] Gardenia jasminoides is the dried ripe fruit of the plant Gardenia jasminoides Ellis of the Rubiaceae family. It is cold in nature and bitter in taste, and belongs to the heart, lung, and triple energizer meridians. It has the effects of purging fire and relieving restlessness, clearing away heat and promoting diuresis, cooling blood and detoxifying, and is widely used clinically. Carbonized Gardenia jasminoides is a processed variety of Gardenia jasminoides, which was first recorded in "Emergency Prescriptions Kept Up One's Sleeve" in the Jin Dynasty: roasted into powder; in modern times, it has been recorded in the national processing specifications and the processing specifications of many provinces and cities. The main processing method is to take the clean Gardenia jasminoides and place it in a frying container, stir-fry it over high heat until the surface is dark brown or charred black, and the inside is charred yellow or charred brown, then take it out and let it cool. After carbonizing Gardenia jasminoides, the hemostatic effect is enhanced and it is often used to treat gastrointestinal bleeding.

[0003] During the carbonization process of Gardenia jasminoides, due to the high temperature effect, the volatile components inside Gardenia jasminoides are gradually released. These volatile components undergo chemical reactions during the frying process to form new compounds, giving carbonized Gardenia jasminoides a unique charred aroma. Compared with raw Gardenia jasminoides, carbonized Gardenia jasminoides has a strong charred aroma and has a certain degree of recognition. This change may be related to the enhanced hemostatic effect of Gardenia jasminoides to a certain extent.

[0004] The research group of the inventor of the present invention previously analyzed the volatile oil components of different processed products of Gardenia jasminoides by gas chromatography-mass spectrometry (GC-MS) and found that the volatile components of carbonized Gardenia jasminoides changed greatly. A total of 43 compounds were identified from carbonized Gardenia jasminoides, among which 29 components such as 2,6-dimethylpyrazine were new components produced by processing, and the content of 4-methylene-α-isophorone increased sharply, which may be directly related to the enhanced hemostatic effect of carbonized Gardenia jasminoides. This finding suggests that the volatile components of carbonized Gardenia jasminoides may also be one of the material bases for hemostasis. However, GC-MS has certain limitations in the characterization of charred aroma, the detection of high-boiling point, low-volatility, and thermally unstable compounds, and the identification of isomers.

[0005] Gas chromatography-ion mobility spectrometry (GC-IMS) is a new type of gas separation and detection technology developed in recent years. It combines the high separation performance of gas chromatography and the advantages of rapid response and high sensitivity of ion mobility spectrometry, and is widely used in food safety detection, disease detection, food flavor analysis, traditional Chinese medicine resources, processing, etc. Because of its high sensitivity, it can detect trace amounts of volatile organic compounds, which is particularly important for the trace components that may exist in the charcoal aroma. At the same time, GC-IMS has a fast analysis speed and can complete the detection of a large number of samples in a short time, which can improve the efficiency of the characterization of the charcoal aroma. Therefore, GC-IMS has good application prospects in the identification and visualization of volatile components during the carbonization process of traditional Chinese medicine, and can be further applied to the judgment of the processing degree of Gardenia jasminoides Ellis charcoal. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for judging the processing degree of Gardenia jasminoides Ellis charcoal based on headspace-GC-IMS differential volatile components to solve the problems existing in the above-mentioned prior art. The method provided by the present invention can quickly and non-destructively judge, without complex sample pretreatment, the method is simple, environmentally friendly, has a low detection cost, the result is intuitive, and is suitable for batch, rapid, objective and accurate judgment of the processing degree of Gardenia jasminoides Ellis charcoal, and can provide key data support for the quality control of the production process.

[0007] To achieve the above purpose, the present invention provides the following scheme:

[0008] The present invention provides a method for judging the processing degree of Gardenia jasminoides Ellis charcoal based on headspace-GC-IMS differential volatile components, including the following steps:

[0009] Take the Gardenia jasminoides Ellis charcoal to be tested, powder it, place it in a headspace injection bottle, incubate, inject the sample, and obtain a fingerprint spectrum through GC-IMS detection;

[0010] Analyze the fingerprint spectrum to determine the characteristic volatile components and non-characteristic volatile components of the Gardenia jasminoides Ellis charcoal to be tested;

[0011] Judge the processing degree of the Gardenia jasminoides Ellis charcoal to be tested according to the peak intensity ratio of the characteristic volatile components and non-characteristic volatile components;

[0012] The non-characteristic volatile components are: 2-isopropyl-4-methylthiazole, (E)-2-pentenal - monomer and ethyl acetate;

[0013] The characteristic volatile components are: octanoic acid, 3-methylthiopropionaldehyde - monomer, 2-methyltetrahydrofuran-3-one - dimer, furfuryl propionate, 2-acetyl-2-thiazoline - monomer, butyl butyrate - monomer, pyrrolidine, ethyl acrylate and 1-octen-3-one.

[0014] Further, among the characteristic volatile components, it is determined whether the processing degree of the to-be-detected stir-fried Gardenia carbon is insufficient based on the peak intensity ratios of octanoic acid, 3-methylthiopropionaldehyde monomer, and 2-methyltetrahydrofuran-3-one dimer to the non-characteristic volatile components;

[0015] It is determined whether the processing degree of the to-be-detected stir-fried Gardenia carbon is existent based on the peak intensity ratios of furfuryl propionate, 2-acetyl-2-thiazoline monomer, and butyl butyrate monomer to the non-characteristic volatile components;

[0016] It is determined whether the processing degree of the to-be-detected stir-fried Gardenia carbon is excessive based on the peak intensity ratios of pyrrolidine, ethyl acrylate, and 1-octen-3-one to the non-characteristic volatile components.

[0017] Further, when the following conditions are simultaneously met, it is determined that the processing degree of the to-be-detected stir-fried Gardenia carbon is insufficient:

[0018] ① 2-isopropyl-4-methylthiazole: octanoic acid: 3-methylthiopropionaldehyde monomer: 2-methyltetrahydrofuran-3-one dimer = 1: (3 - 5): (0.5 - 2): (0.5 - 3);

[0019] ② (E)-2-pentenal monomer: octanoic acid: 3-methylthiopropionaldehyde monomer: 2-methyltetrahydrofuran-3-one dimer = 1: (2 - 5): (0.5 - 2): (0.5 - 3);

[0020] ③ ethyl acetate: octanoic acid: 3-methylthiopropionaldehyde monomer: 2-methyltetrahydrofuran-3-one dimer = 1: (1 - 2): (0.2 - 0.5): (0.2 - 1)

[0021] When the following conditions are simultaneously met, it is determined that the processing degree of the to-be-detected stir-fried Gardenia carbon is existent:

[0022] ① 2-isopropyl-4-methylthiazole: furfuryl propionate: 2-acetyl-2-thiazoline monomer: butyl butyrate monomer = 1: (1.5 - 4): (1 - 2): (4 - 6);

[0023] ② (E)-2-pentenal monomer: furfuryl propionate: 2-acetyl-2-thiazoline monomer: butyl butyrate monomer = 1: (1 - 2): (0.5 - 2): (2.5 - 4);

[0024] ③ ethyl acetate: furfuryl propionate: 2-acetyl-2-thiazoline monomer: butyl butyrate monomer = 1: (0.5 - 2): (0.5 - 1): (1.5 - 3);

[0025] When the following conditions are simultaneously met, it is determined that the processing degree of the to-be-detected stir-fried Gardenia carbon is excessive:

[0026] ①2-Isopropyl-4-methylthiazole: pyrrolidine: ethyl acrylate: 1-octen-3-one = 1: (1.5 - 4): (2 - 5): (3 - 8);

[0027] ②(E)-2-Pentenal - monomer: pyrrolidine: ethyl acrylate: 1-octen-3-one = 1: (1 - 5): (1 - 6): (2 - 10);

[0028] ③Ethyl acetate: pyrrolidine: ethyl acrylate: 1-octen-3-one = 1: (0.5 - 2): (1 - 2): (1 - 3).

[0029] Further, the incubation condition is incubation at 80 °C for 15 min.

[0030] Further, the sample injection condition is injecting 200 μL, incubation rotation speed: 500 r / min, sample injection needle temperature: 85 °C.

[0031] Further, MXT-WAX chromatographic column, 15 m × 0.53 mm, 1.0 μm; column temperature: 60 °C; carrier gas: high-purity nitrogen, purity ≥ 99.999%; flow rate: 0 - 2 min, 2 mL / min; 2 - 30 min, 2 - 30 mL / min; 30 - 35 min, 30 - 150 mL / min; 35 - 45 min, 150 mL / min.

[0032] Further, the IMS condition is: IMS temperature: 45 °C; drift gas: high-purity nitrogen, purity ≥ 99.999%, flow rate: 150 mL / min.

[0033] The present invention discloses the following technical effects:

[0034] Gardenia carbon, as a representative variety of stir-frying to keep the nature in traditional Chinese medicine processing, has significantly changed in its appearance traits and efficacy compared with raw Gardenia jasminoides Ellis. The burnt aroma generated after stir-frying is the main characteristic of its odor change. By using GC-IMS detection and analysis on Gardenia carbon samples with different processing degrees in the present invention, 172 volatile components are detected in Gardenia carbon, and 124 compounds are identified with the help of NIST database and IMS database, including 11 categories of compounds such as alcohols, ketones, aldehydes, organic acids, esters, ethers, benzenes, terpenes, alkenes, alkanes and heterocyclic compounds. Three characteristic volatile components are respectively screened out in the under-processed, nature-kept and over-processed samples, and at the same time, three non-characteristic volatile components are obtained; combined with cluster analysis, the processing degrees of Gardenia carbon samples with different processing degrees can be effectively discriminated; the result has high accuracy, realizing the rapid judgment of the processing degree of Gardenia carbon from volatile odor substances, and providing a new idea for judging the processing degree of Gardenia carbon.

[0035] The method provided by the present invention can make judgments quickly and without damage, without complex sample pretreatment. The method is simple, environmentally friendly, has low detection costs, and the results are intuitive. It is suitable for batch, rapid, objective, and accurate judgment of the processing degree of gardenia carbon, and can provide key data support for quality control in the production process. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0037] Figure 1 It is the gas chromatography-ion mobility spectrometry diagram of gardenia carbon samples at different times;

[0038] Figure 2 It is Figure 1 The two-dimensional top view of

[0039] Figure 3 It is the classification of volatile components in gardenia carbon samples with different processing degrees; A: Classification diagram of volatile components with different processing degrees; B: Peak intensity diagram of various volatile components with different processing degrees;

[0040] Figure 4 It is the fingerprint spectrum of a part of the volatile components of gardenia carbon samples with different processing degrees;

[0041] Figure 5 It is the fingerprint spectrum of another part of the volatile components of gardenia carbon samples with different processing degrees;

[0042] Figure 6 It is the PCA analysis diagram of gardenia carbon samples with different processing degrees;

[0043] Figure 7 It is the GC-IMS three-dimensional spectrum diagram of under-verification, existence verification, and over-verification;

[0044] Figure 8 It is Figure 7 The two-dimensional top view of

[0045] Figure 9 It is the PCA analysis diagram of under-verification, existence verification, and over-verification. Detailed Embodiments

[0046] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0047] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0048] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0049] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the present invention specification are obvious to those skilled in the art. The present invention specification and examples are merely exemplary.

[0050] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0051] Example 1

[0052] 1. Materials

[0053] 1.1 Main Instruments

[0054] XS105DU one-ten-thousandth analytical balance (Mettler-Toledo), DFT-100 type portable high-speed traditional Chinese medicine grinder (Wenling Dade Traditional Chinese Medicine Machinery Co., Ltd.), CY small electric heating traditional Chinese medicine frying machine (Jiangyin Zhutang Mingke Machinery Factory, power 6KW, power supply 220 / 380V), Flavor analyzer (GAS Company, Germany).

[0055] 1.2 Samples

[0056] Raw gardenia fruits were purchased from Anguo City, Hebei Province (batch number 20200812), and were identified by Researcher Zhang Cun of the Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences as the dried mature fruits of Gardenia jasminoides Ellis, a plant of the genus Gardenia in the Rubiaceae family.

[0057] 2. Methods

[0058] 2.1 Preparation of Gardenia Carbon Decoction Pieces

[0059] The preparation of Gardenia carbon was referred to the "National Chinese Medicine Processing Specification" in 1988: Set the temperature of the medicine frying machine to 300 °C. After the temperature is stable, put 500 g of raw Gardenia jasminoides Ellis into it. Set the rotation speed of the medicine frying machine to medium speed and keep stir-frying until the surface is dark brown, and the inner surface of the pericarp and the surface of the seeds are yellowish brown or dark brown. Take out and let it cool.

[0060] Sampling of samples during the processing: Operate according to the above processing technological process. After putting in the Gardenia jasminoides Ellis decoction pieces, start timing. Samples are taken at the 0th min, 2nd min, 4th min, 6th min, 8th min, 9th min, 10th min, 11th min, 12th min, 13th min, 14th min, 15th min, 16th min, and 17th min respectively, with a total of 14 samples, which are respectively recorded as ZZT0-ZZT13 (where ZZT0 is raw Gardenia jasminoides Ellis). The frying time of Gardenia carbon is 17 min.

[0061] Among them, the processing degree of Gardenia carbon with a frying time of 6-10 min is insufficient, the processing degree of Gardenia carbon with a frying time of 11-13 min is keeping the nature, and the processing degree of Gardenia carbon with a frying time of 14-17 min is excessive.

[0062] 2.2 Headspace Sampling Method

[0063] Take an appropriate amount of Gardenia carbon decoction pieces and powder them. Pass through a No. 4 sieve. Take 1.0 g of the sample powder, weigh it accurately, put it into a 20 mL stoppered headspace vial, incubate at 80 °C for 15 min and then inject 200 μL. The incubation rotation speed is 500 r / min, and the injection needle temperature is 85 °C. Each sample is measured in parallel 3 times.

[0064] 2.3 Gas Chromatography-Ion Mobility Spectrometry Conditions

[0065] MXT-WAX chromatographic column (15 m × 0.53 mm, 1.0 μm), the column temperature is 60 °C, the carrier gas is high-purity nitrogen (purity ≥ 99.999%), flow rate: 0-2 min, 2 mL / min; 2-30 min, 2-30 mL / min; 30-35 min, 30-150 mL / min; 35-45 min, 150 mL / min, and the running time is 45 min.

[0066] The drift tube is 9.8 cm long, the linear voltage in the tube is 400 V / cm, the drift tube temperature is 45 °C, the drift gas is high-purity nitrogen (purity ≥ 99.999%), the flow rate is 150 mL / min, and the ion mobility detector temperature is 45 °C; the external standard is n-ketone C4-C9, and the retention index (RI) of each compound is calculated.

[0067] 2.3 Data Analysis

[0068] The GC×IMS Library Search V 2.2.1 analysis software was used to qualitatively analyze the volatile flavor substances in the samples by using the built-in databases of the National Institute of Standards and Technology of the United States (NIST) and the IMS database. Each point in the spectrogram represents one kind of volatile organic compound. After establishing a standard curve for it, quantitative analysis can be carried out; the Reporter plug-in can directly compare the spectrogram differences between samples (three-dimensional spectrogram, two-dimensional top view, and difference spectrogram); the Gallery Plot plug-in can conduct fingerprint spectrogram comparison to intuitively and quantitatively compare the differences in volatile organic compounds between different samples; the SIMCA-14.0 software was used for principal component analysis (PCA) to screen out the differential volatile components of Gardeniae Carbonis with different processing degrees.

[0069] 3 Results

[0070] 3.1 Gas Chromatography-Ion Mobility Spectrometry Analysis

[0071] The gas chromatography-ion mobility spectrometry of Gardeniae Carbonis samples at different times is shown in Figure 1 , it can be seen that a large number of characteristic volatile organic compound components can be detected in the samples at each time during the frying process of Gardeniae Carbonis.

[0072] Directly compare the differences in volatile components of Gardeniae Carbonis at different sampling times. Use the Reporter plug-in to analyze the GC-IMS spectrograms of Gardeniae Carbonis samples at different sampling times. It can be directly seen from the three-dimensional spectrogram that there are obvious differences in the volatile components of Gardeniae Carbonis samples with different processing degrees. In order to better compare and analyze the changes in volatile organic compounds during the frying process of Gardeniae Carbonis, the spectrogram was dimension-reduced by adopting the difference comparison mode. Figure 2 For Figure 1The two-dimensional top view, with the vertical coordinate representing the retention time of gas chromatography and the horizontal coordinate representing the ion migration time. To more clearly compare the differences between samples, the raw gardenia jasminoides Ellis sample was used as a reference, and the other samples were successively subtracted from the reference. After subtraction, the background became white. If the content of volatile organic compounds in other samples was higher than that of the reference, the substance appeared red; if the content of volatile organic compounds in other samples was lower than that of the reference, the substance appeared blue. The red vertical line at the horizontal coordinate of 1.0 was the reaction ion peak (RIP) after normalization. Each point on both sides of the RIP peak represented a volatile component, and the depth of the color of the point intuitively reflected the change in the concentration of the volatile component. There were differences in the volatile components in the gardenia jasminoides Ellis charcoal samples at different sampling times. Taking the retention time of 1000 s as the dividing line, the content of volatile components increased before 1000 s (the color of the spots deepened), and new volatile components gradually appeared after 1000 s (new spots appeared), and the color of the spots gradually deepened with the increase in the degree of processing. It indicated that the types and contents of volatile components in gardenia jasminoides Ellis charcoal increased during frying compared with raw gardenia jasminoides Ellis.

[0073] 3.2 Qualitative identification and analysis

[0074] A total of 172 volatile components were identified by GC-IMS analysis, but only 124 were identified due to limitations in the NIST and IMS databases, and the information of 48 components remained to be confirmed. Among the 124 volatile components, there were 11 categories of compounds including esters, alcohols, ketones, aldehydes, organic acids, ethers, benzenes, terpenes, alkenes, alkanes, and heterocyclic compounds. The detailed results of the retention index, relative migration time, and odor description information of all components are shown in Table 1. Since the dimer masses of 13 compounds such as acetaldehyde, pentanal, propyl propionate, (E)-2-pentenal, 3-penten-2-one, 2-hexanone, heptanal, (-)-carvone, butyl butyrate, (E)-2-heptenal, 5-methylfurfural, propionic acid, and 3-(methylthio)propanal were relatively high, two peaks appeared for some compounds, corresponding to the monomer and dimer respectively.

[0075] Among the partially detected volatile components in the gardenia jasminoides Ellis charcoal samples with different degrees of processing, there were 35 esters, accounting for 28.23%; 27 aldehydes, accounting for 21.77%; 19 ketones, accounting for 15.32%; 12 heterocyclic compounds, accounting for 9.68%; 11 alcohols, accounting for 8.87%; 10 organic acids, accounting for 8.06%; 4 ethers, accounting for 3.23%; and 6 others, accounting for 4.84%. Esters, aldehydes, and ketones were the main volatile components in gardenia jasminoides Ellis charcoal, and the caramel-like odor mainly originated from the above three categories of components, as shown in Figure 3 A in

[0076] 3.3 Relative quantitative analysis

[0077] From Figure 3As can be seen from Figure B, the total contents of esters, aldehydes, ketones, organic acids, and ether compounds show a trend of first increasing and then decreasing. The total contents of heterocyclic and alcohol compounds first decrease and then increase, and the contents of other compounds generally decrease. Among them, the content of ester compounds is the highest in the samples at 10 and 11 minutes, the content of aldehyde compounds is the highest in the samples at 6 and 8 minutes, the content of ketone compounds is the highest in the samples at 11 and 12 minutes, the content of heterocyclic compounds is the highest in the samples at 14 and 16 minutes, the content of alcohol compounds is the highest in the samples at 16 and 17 minutes, the content of organic acid compounds is the highest in the samples at 9 and 10 minutes, the content of ether compounds is the highest in the samples at 11, 12, and 13 minutes, and the content of other compounds is the highest in raw gardenia jasminoides Ellis.

[0078] 3.4 Fingerprint analysis

[0079] To clarify which specific volatile components are different in the gardenia jasminoides Ellis charcoal samples with different processing degrees, the GalleryPlot plug-in was used to select all peaks for fingerprint comparison. The fingerprint diagrams were automatically generated for all the peaks to be analyzed in the obtained GC-IMS two-dimensional diagrams, as shown in Figure 4 and Figure 5 . Each row in the figure represents all the signal peaks selected in a sample, and each column represents the signal peaks of the same volatile component in the gardenia jasminoides Ellis charcoal slices with different processing degrees. It can be seen from the figure the complete volatile component information and the differential component information of the gardenia jasminoides Ellis charcoal samples with different processing degrees.

[0080] Through Figure 4 and Figure 5 's fingerprint diagrams, it can be seen that there are significant differences in the gardenia jasminoides Ellis charcoal samples with different processing degrees. The volatile components they contain have both common regions and their own characteristic peak regions. In terms of content, some show a trend of gradually decreasing or increasing, and there are also characteristic components that only appear during the processing. Figure 4 The volatile components shown in regions A and B in Figure show a trend of gradually decreasing or disappearing in content as the processing time prolongs. Figure 4 In Figure, regions C, Figure 5 regions F and G in Figure are the characteristic components of the gardenia jasminoides Ellis charcoal samples with different processing degrees. Figure 4 Region E in Figure is the newly added volatile component that increases with the deepening of the processing degree. Figure 4The volatile components in region D of Zhizi are those with insignificant changes during the entire processing. By screening characteristic volatile components, it was found that the peak intensities of octanoic acid, 3-methylthiopropionaldehyde - monomer, and 2-methyltetrahydrofuran - 3-one - dimer were relatively high in the under-processed samples; the peak intensities of furfuryl propionate, 2-acetyl-2-thiazoline - monomer, and butyl butyrate - monomer were relatively high in the samples with proper processing; the peak intensities of pyrrolidine, ethyl acrylate, and 1-octen-3-one were relatively high in the over-processed samples. These can be used as the characteristic volatile components of under-processed, properly processed, and over-processed samples respectively. At the same time, it was found that the peak intensity values of 2-isopropyl-4-methylthiazole, (E)-2-pentenal - monomer, and ethyl acetate were close in all samples, and their peak intensities were less affected by temperature and time, being relatively stable. These can be used as non-characteristic volatile components of Zhizi charcoal with different processing degrees. Based on this, the processing degree of Zhizi charcoal was judged by the ratio range of the peak intensities of the characteristic volatile components with relatively high peak intensities and the non-characteristic volatile components with relatively small changes in peak intensities in Zhizi charcoal with different processing degrees. The peak intensities of the characteristic and non-characteristic volatile components in Zhizi charcoal samples are shown in Tables 1 - 4 below.

[0081] Table 1 Peak Intensities of Non-characteristic Volatile Components

[0082]

[0083] Table 2 Peak Intensities of Characteristic Volatile Components in Under-processed Samples

[0084]

[0085] Table 3 Peak Intensities of Characteristic Volatile Components in Samples with Proper Processing

[0086]

[0087]

[0088] Table 4 Peak Intensities of Characteristic Volatile Components in Over-processed Samples

[0089]

[0090] The method for judging the processing degree of Zhizi charcoal based on the ratio range of the peak intensities of the characteristic and non-characteristic volatile components in Zhizi charcoal samples is as follows:

[0091] If the following conditions are simultaneously met: ① 2-isopropyl-4-methylthiazole: octanoic acid: 3-(methylthio)propanal - monomer: 2-methyltetrahydrofuran-3-one - dimer = 1:(3 - 5):(0.5 - 2):(0.5 - 3); ② (E)-2-pentenal - monomer: octanoic acid: 3-(methylthio)propanal - monomer: 2-methyltetrahydrofuran-3-one - dimer = 1:(2 - 5):(0.5 - 2):(0.5 - 3); ③ ethyl acetate: octanoic acid: 3-(methylthio)propanal - monomer: 2-methyltetrahydrofuran-3-one - dimer = 1:(1 - 2):(0.2 - 0.5):(0.2 - 1); it is judged that the processing degree of the tested carbonized gardenia is insufficient.

[0092] If the following conditions are simultaneously met: ① 2-isopropyl-4-methylthiazole: furfuryl propionate: 2-acetyl-2-thiazoline - monomer: butyl butyrate - monomer = 1:(1.5 - 4):(1 - 2):(4 - 6); ② (E)-2-pentenal - monomer: furfuryl propionate: 2-acetyl-2-thiazoline - monomer: butyl butyrate - monomer = 1:1 - 2:(0.5 - 2):(2.5 - 4); ③ ethyl acetate: furfuryl propionate: 2-acetyl-2-thiazoline - monomer: butyl butyrate - monomer = 1:(0.5 - 2):(0.5 - 1):(1.5 - 3); it is judged that the processing degree of the tested carbonized gardenia is existent.

[0093] If the following conditions are simultaneously met: ① 2-isopropyl-4-methylthiazole: pyrrolidine: ethyl acrylate: 1-octen-3-one = 1:(1.5 - 4):(2 - 5):(3 - 8); ② (E)-2-pentenal - monomer: pyrrolidine: ethyl acrylate: 1-octen-3-one = 1:(1 - 5):(1 - 6):(2 - 10); ③ ethyl acetate: pyrrolidine: ethyl acrylate: 1-octen-3-one = 1:(0.5 - 2):(1 - 2):(1 - 3); it is judged that the processing degree of the tested carbonized gardenia is excessive.

[0094] 3.5 Stoichiometric analysis

[0095] Using the Dynamic PCA plug-in to perform dynamic principal component analysis on all peaks of carbonized gardenia samples with different processing degrees, taking the peak intensities of each volatile component as variables and importing them into the SMICA 14.1 software for PCA analysis, the differences between carbonized gardenia samples with different processing degrees can be intuitively displayed. A short distance between samples represents small differences, while a long distance represents obvious differences. The results are shown in Figure 6 , it can be seen that carbonized gardenia samples with different processing degrees are clustered separately and are clearly distinguishable (R 2 X = 0.961, Q 2 = 0.856), indicating that the discrimination effect of carbonized gardenia with different processing degrees is good, and there are obvious differences in their volatile components.

[0096] Verification example

[0097] Take Gardenia carbonis with different processing degrees of insufficient, carbonized and excessive, and detect them according to the method described in Example 1. Each sample is measured in parallel 3 times.

[0098] Results

[0099] 1. Visual analysis

[0100] The three-dimensional GC-IMS spectra of insufficient processing (insufficient verification), carbonized (carbonized verification), and excessive processing (excessive verification) are as shown in Figure 7 shown, and the two-dimensional top-down difference map of volatile components is as shown in Figure 8 shown. From left to right are raw Gardenia jasminoides, insufficient processing (insufficient verification), carbonized processing (carbonized verification), and excessive processing (excessive verification). It can be seen from Figure 7 - Figure 8 that the volatile components in Gardenia carbonis samples with different processing degrees are significantly different, and there are obvious differences in the color and quantity of spots in the spectra.

[0101] 2. Peak intensity analysis

[0102] The peak intensities of characteristic and non-characteristic volatile components in the samples of insufficient processing (insufficient verification), carbonized (carbonized verification), and excessive processing (excessive verification) are shown in Tables 5 - 8. The processing degree of Gardenia carbonis is judged according to the ratio range of the peak intensities of characteristic volatile components to non-characteristic volatile components:

[0103] Verification results of insufficient processing of Gardenia carbonis: ① 2-Isopropyl-4-methylthiazole: Octanoic acid: 3-Methylthiopropionaldehyde - monomer: 2-Methyltetrahydrofuran-3-one - dimer = 1: 3.40: 0.85: 1.77; ② (E)-2-Pentenal - monomer: Octanoic acid: 3-Methylthiopropionaldehyde - monomer: 2-Methyltetrahydrofuran-3-one - dimer = 1: 4: 1.01: 2.08; ③ Ethyl acetate: Octanoic acid: 3-Methylthiopropionaldehyde - monomer: 2-Methyltetrahydrofuran-3-one - dimer = 1: 1.50: 0.38: 0.78;

[0104] Verification results of carbonized Gardenia carbonis: ① 2-Isopropyl-4-methylthiazole: Furyl propionate: 2-Acetyl-2-thiazoline - monomer: Butyl butyrate - monomer = 1: 1.67: 1.39: 4.54; ② (E)-2-Pentenal - monomer: Furyl propionate: 2-Acetyl-2-thiazoline - monomer: Butyl butyrate - monomer = 1: 1.44: 1.20: 3.93; ③ Ethyl acetate: Furyl propionate: 2-Acetyl-2-thiazoline - monomer: Butyl butyrate - monomer = 1: 0.76: 0.64: 2.08;

[0105] Verification results for the overprocessed Zhizi charcoal: ① 2-Isopropyl-4-methylthiazole: Pyrrolidine: Ethyl acrylate: 1-Octen-3-one = 1: 3.40: 4.41: 7.62; ② (E)-2-Pentenal - monomer: Pyrrolidine: Ethyl acrylate: 1-Octen-3-one = 1: 4.13: 5.36: 9.25; ③ Ethyl acetate: Pyrrolidine: Ethyl acrylate: 1-Octen-3-one = 1: 1.28: 1.65: 2.85.

[0106] It can be seen that the peak intensity ratios of the characteristic volatile components to the non-characteristic volatile components in the verification samples of Zhizi charcoal with different processing degrees all meet the standards for the processing degree of Zhizi charcoal established in Example 1. The sample verification shows that the method for judging the processing degree of Zhizi charcoal by the peak intensity ratio range of the characteristic volatile components to the non-characteristic volatile components in the present invention is accurate and feasible.

[0107] Table 5 Peak intensities of non-characteristic volatile components in each group

[0108]

[0109] Table 6 Peak intensities of characteristic volatile components in the underprocessed samples of each group

[0110]

[0111] Table 7 Peak intensities of characteristic volatile components in the samples with proper processing of each group

[0112]

[0113] Table 8 Peak intensities of characteristic volatile components in the overprocessed samples of each group

[0114]

[0115] 3. PCA statistical analysis

[0116] Using the Dynamic PCA plugin to perform dynamic principal component analysis on all peaks of each group of Zhizi charcoal samples, taking the peak intensities of each volatile component as variables, and importing them into the SMICA 14.1 software for PCA statistical analysis. The PCA results of Zhizi charcoal samples with different processing degrees (ZZT0-ZZT13, underprocessed verification, proper processing verification, overprocessed verification) are as Figure 9 shown. It can be seen that the underprocessed verification samples added are grouped with the underprocessed samples of ZZT3-ZZT6, the proper processing verification samples are grouped with the properly processed samples of ZZT7-ZZT9, and the overprocessed verification samples are grouped with the overprocessed samples of ZZT10-ZZT13, indicating that the method provided by the present invention for judging the processing degree of Zhizi charcoal by the peak intensity ratio of the characteristic volatile components to the non-characteristic volatile components is accurate and feasible.

[0117] In summary, in the present invention, 172 volatile components in the prepared Gardenia carbon samples with different processing degrees are detected by GC-IMS analysis, and 124 compounds are identified with the help of the NIST database and the IMS database, including 11 categories of compounds such as alcohols, ketones, aldehydes, organic acids, esters, ethers, benzenes, terpenes, alkenes, alkanes, and heterocyclic compounds. Three characteristic volatile components are respectively screened out from the under-processed, carbonized, and over-processed samples, and at the same time, three non-characteristic volatile components are obtained; combined with cluster analysis, the processing degrees of the prepared Gardenia carbon samples with different processing degrees can be effectively discriminated; the result has high accuracy, realizing the rapid judgment of the processing degree of the prepared Gardenia carbon from volatile odor substances, and providing a new idea for judging the processing degree of the prepared Gardenia carbon.

[0118] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for judging the degree of processing of Gardenia charcoal based on headspace-GC-IMS differential volatile components, characterized in that: The following steps are involved: Take the Gardenia charcoal to be tested, grind it into powder, put it in a headspace injection bottle, incubate it, inject it, and obtain the fingerprint spectrum by GC-IMS detection; The fingerprint was analyzed to determine the characteristic volatile components and non-characteristic volatile components of the tested gardenia charcoal. The processing degree of the tested Gardenia charcoal is judged according to the peak intensity ratio of the characteristic volatile components to the non-characteristic volatile components; The non-characteristic volatile components are: 2-isopropyl-4-methylthiazole, (E)-2-pentenal-monomer and ethyl acetate; The characteristic volatile components are: octanoic acid, 3-methylthiopropionaldehyde-monomer, 2-methyltetrahydrofuran-3-one-dimer, furfuryl propionate, 2-acetyl-2-thiazoline-monomer, butyl butyrate-monomer, tetrahydropyrrole, ethyl acrylate and 1-octen-3-one; In the characteristic volatile components, judging whether the processing degree of the tested Gardenia charcoal is insufficient according to the peak intensity ratio of octanoic acid, 3-methylthiopropionaldehyde-monomer and 2-methyltetrahydrofuran-3-one-dimer to the non-characteristic volatile components; Judging whether the processing degree of the tested Gardenia charcoal is in good condition according to the peak intensity ratio of furfuryl propionate, 2-acetyl-2-thiazoline-monomer, butyl butyrate-monomer and the non-characteristic volatile components; Judging whether the degree of processing of the Gardenia charcoal to be tested is excessive according to the peak intensity ratio of tetrahydropyrrole, ethyl acrylate, 1-octen-3-one and the non-characteristic volatile component; The GC conditions were: MXT-WAX column, 15 m × 0.53 mm, 1.0 µm; Column temperature: 60°C; Carrier gas: high-purity nitrogen, purity ≥99.999%; flow rate: 0~2 min, 2 mL / min; 2~30 min, 2~30 mL / min; 30~35 min, 30~150 mL / min; 35~45 min, 150 mL / min.

2. The method according to claim 1, characterized in that When the following conditions are met at the same time, the degree of processing of the tested Gardenia charcoal is judged to be insufficient: ①2-isopropyl-4-methylthiazole:octanoic acid:3-methylthiopropionaldehyde-monomer:2-methyltetrahydrofuran-3-one-dimer=1:(3~5):(0.5~2):(0.5~3); ②(E)-2-pentenal-monomer: octanoic acid: 3-methylthiopropionaldehyde-monomer: 2-methyltetrahydrofuran-3-one-dimer=1: (2~5): (0.5~2): (0.5~3); ③ Ethyl acetate: octanoic acid: 3-methylthiopropionaldehyde-monomer: 2-methyltetrahydrofuran-3-one-dimer=1: (1~2): (0.2~0.5): (0.2~1); When the following conditions are met at the same time, the degree of processing of the tested Gardenia charcoal is judged to be intact: ①2-isopropyl-4-methylthiazole: furfuryl propionate: 2-acetyl-2-thiazoline-monomer: butyl butyrate-monomer=1:(1.5~4):(1~2):(4~6); ②(E)-2-pentenal-monomer: furfuryl propionate: 2-acetyl-2-thiazoline-monomer: butyl butyrate-monomer=1:(1~2):(0.5~2):(2.5~4); ③ Ethyl acetate: furfuryl propionate: 2-acetyl-2-thiazoline-monomer: butyl butyrate-monomer = 1: (0.5~2): (0.5~1): (1.5~3); When the following conditions are met at the same time, the degree of processing of the Gardenia charcoal to be tested is judged to be too high: ①2-isopropyl-4-methylthiazole: tetrahydropyrrole: ethyl acrylate: 1-octen-3-one = 1: (1.5~4): (2~5): (3~8); ②(E)-2-pentenal-monomer: tetrahydropyrrole: ethyl acrylate: 1-octen-3-one = 1: (1~5): (1~6): (2~10); ③Ethyl acetate: tetrahydropyrrole: ethyl acrylate: 1-octen-3-one = 1: (0.5~2): (1~2): (1~3).

3. The method according to claim 1, characterized in that The incubation condition is 80° C. for 15 min.

4. The method according to claim 1, characterized in that The injection conditions are as follows: 200 μL injection, incubation speed: 500 r / min, injection needle temperature: 85°C.

5. The method according to claim 1, characterized in that The conditions of the IMS are: IMS temperature: 45°C; drift gas: high-purity nitrogen, purity ≥ 99.999%; Flow rate: 150 mL / min.

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