A method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds

Abstract

This invention discloses a method for distinguishing *Mushroom arborescens* strains by detecting and identifying characteristic volatile aroma compounds. The method determines whether a sample is *Mushroom arborescens* by detecting and judging the characteristic volatile aroma substances in the edible fungus sample and measuring their content. This invention can rapidly distinguish between two *Mushroom arborescens* species, *Pleurotus ostreatus* and *Pleurotus eryngii*. This invention has the advantages of fast response, high sensitivity, simple operation, and low cost, and can quickly and efficiently detect and distinguish *Pleurotus ostreatus*, *Pleurotus eryngii*, and *Pleurotus ostreatus* granules.

Description

Technical Field

[0001] The invention belongs to the technical field of fungal volatile gas molecule detection, and in particular relates to a method for distinguishing Agaricus punctatus strains through volatile characteristic aroma compounds. Background Art

[0002] Edible fungi are loved by humans because of their high nutritional content, low fat content and unique taste and mouthfeel. In recent years, people have conducted in-depth research on the antioxidant, anti-inflammatory, immunomodulatory, anti-tumor and antibacterial functions of edible fungi. It is found that edible fungi have high content of recognized effective bioactive substances such as polysaccharides, proteoglycans, steroids, etc., so they show good antioxidant and cancer prevention activities, and have great potential in protecting human health and preventing diseases. In the past 30 years, the world's edible fungi production has increased by about 10%. After the 21st century, China's edible fungi production accounted for more than 70% of the world's total production, making it the world's largest producer and consumer of edible fungi.

[0003] Hypsizigus marmoreus has been commercially cultivated in my country since the 1980s and is an important edible mushroom variety that has been cultivated in factories. The fruiting body of this mushroom includes a long stalk and a closed cap with spots or marble patterns. The cap is dark brown, and the color changes to gray-brown when mature, and then to milky brown. It has rich nutritional value and certain medicinal value. The protein of Hypsizigus marmoreus contains a full range of amino acids, including 8 essential amino acids for the human body. Among them, the content of lysine and arginine is higher than that of general mushrooms, which plays an important role in the physiological development of the human body. Hypsizigus marmoreus is also rich in polysaccharide compounds β-1,3-D glucan, which has good anti-tumor activity (dose-dependent inhibition of human liver cancer and colon cancer). In addition, Hypsizigus marmoreus also has antifungal and free radical scavenging activities. Agaricus oleraceus products have a long shelf life, rich aroma, and a very distinctive taste and flavor. Oyster mushroom and Pleurotus ostreatus are two Agaricus oleraceus strains that have been factory-cultivated. They are good low-calorie, low-fat health foods. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] As one aspect of the present invention, the present invention provides a method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds, characterized in that the method comprises the following steps:

[0006] Headspace solid phase microextraction: Weigh the edible fungus fruiting body block sample, place it in a headspace bottle, add o-dichlorobenzene and water, insert the extraction head for headspace adsorption, and insert it into the GC-MS injection port;

[0007] GC-MS detection: The detection was carried out at 250°C in splitless mode to obtain the total ion current spectrum of the edible mushroom block sample;

[0008] GC-MS data analysis: The obtained spectral data were retrieved in series and manually analyzed using the standard mass spectra of the NIST 11 standard spectral library of the Agilent MassHunter workstation. The aroma information was searched in combination with ChemicalBooks. The matching degree greater than 80% was selected as the basis for substance identification. The base peak, m / z and relative abundance were analyzed. The volatile components in the sample were qualitatively and quantitatively analyzed in combination with retention time and MS. The peak area normalization method was used for quantification to obtain the content of each component.

[0009] Evaluation of main volatile flavor substances: OAV is used to evaluate the contribution of each volatile component to the overall flavor of the sample, and the multiple volatile compounds detected are analyzed and compared to identify the characteristic odor molecules that have a significant contribution to the aroma of specific edible fungi;

[0010] Principal component analysis: Principal component analysis is performed based on the content and OAV value of characteristic odor molecules;

[0011] The agaricus strains are Pleurotus eryngii and Pleurotus ostreatus.

[0012] As a preferred embodiment of the method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds described in the present invention: the chromatographic separation procedure of the GC-MS detection is as follows: the initial temperature of the program is 40°C, maintained for 3 minutes; increased to 70°C at a rate of 5°C / min, maintained for 0 minutes; then increased to 90°C at a rate of 2°C / min, maintained for 0 minutes; then increased to 210°C at a rate of 5°C / min, maintained for 0 minutes, and the carrier gas is high-purity helium with a flow rate of 1.0 mL / min.

[0013] As a preferred embodiment of the method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds described in the present invention: the headspace solid phase microextraction is to weigh 1 g of the crushed edible fungus block sample, place it in a headspace bottle, add 10 μL of o-dichlorobenzene and 1 mL of distilled water, mix them evenly, cover the bottle cap and place it in a 55°C water bath for equilibration for 5 minutes, insert the extraction head for headspace adsorption for 30 minutes, then insert it into the GC-MS injection port, and analyze it at 250°C for 5 minutes.

[0014] As a preferred embodiment of the method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds of the present invention: the peak area normalization method is used for quantification, and the calculation formula is:

[0015] mi=f×Ai / (As / ms)

[0016] Wherein, Ai and As are the peak areas or peak heights of the sample to be tested and the internal standard, respectively; ms is the mass of the added internal standard; and mi is the mass of the sample to be tested.

[0017] As a preferred embodiment of the method for distinguishing Agaricus spp. strains by volatile characteristic aroma compounds of the present invention: OAV is used to evaluate the contribution of each volatile component to the overall flavor of the sample, and the OAV calculation formula is:

[0018] OAV=C / T

[0019] Among them, C is the absolute concentration of the olfactory substance, T is its sensory threshold; OAV < 1 indicates that the component has no significant effect on the overall odor; OAV ≥ 1 indicates that the component has an effect on the overall odor.

[0020] As a preferred embodiment of the method for distinguishing Agaricus spp. strains by volatile characteristic aroma compounds described in the present invention: the volatile characteristic aroma compounds are composed of three compounds, namely: 1-octen-3-ol, 3-octanone, and 1-octen-3-one, and the OAV values ​​of the three compounds in the Agaricus spp. strains are all greater than 500.

[0021] As a preferred embodiment of the method for distinguishing Agaricus spp. strains by volatile characteristic aroma compounds described in the present invention: the volatile characteristic aroma compounds are composed of 12 compounds, namely: 1-octen-3-ol, 3-octanone, benzaldehyde, trans-2-octenal, 3-octanol, 1-octen-3-one, n-octanal, 1-nonanol, nonanal, n-heptanol, trans-2-nonenal, (2E, 4E)-2,4-octadienal, and the OAV values ​​of the 12 compounds in the Agaricus spp. strains are all greater than 1.

[0022] As a preferred embodiment of the method for distinguishing Agaricus odoratus strains by volatile characteristic aroma compounds described in the present invention: the OAV ratio of trans-2-nonenal between Oyster mushroom and Pleurotus eryngii is greater than 5; the content of 3-methylbutanal in Oyster mushroom is less than 0.002 μg / g, and OAV is less than 0.1; the OAV of 3-methylbutanal in Pleurotus eryngii is greater than 1.

[0023] As a preferred embodiment of the method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds of the present invention: the gas chromatograph uses an Agilent HP-5ms column.

[0024] As a preferred embodiment of the method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds described in the present invention: the GC-MS mass spectrometer operating conditions are: the transmission line temperature is 220°C, the ion source is 200°C, the electron impact ionization is tuned to 70eV, the mass range is 45 to 500m / z, and the total ion flow spectrum of the edible mushroom block sample is obtained.

[0025] As a preferred embodiment of the method for distinguishing Agaricus sphaerocephala strains by volatile characteristic aroma compounds of the present invention: the retention time of GC-MS, 1-octen-3-ol is 28.0879 min, the retention time of 3-octanone is 20.5767 min, the retention time of benzaldehyde is 30.8171 min, the retention time of trans-2-octenal is 27.6575 min, the retention time of 3-octanol is 26.0821 min, and the retention time of 1-octen-3-ol is 28.0879 min. The retention time of octen-3-one was 22.6821 min, the retention time of n-octanal was 22.1278 min, the retention time of 1-nonanol was 34.142 min, the retention time of nonanal was 26.3158 min, the retention time of n-heptanol was 28.2175 min, the retention time of trans-2-nonenal was 31.0582 min, and the retention time of (2E, 4E)-2,4-octadienal was 31.8206 min.

[0026] Beneficial effects of the present invention: The present invention can detect and judge the characteristic volatile aroma substances in the edible fungus sample, and determine whether the sample is Agaricus eryngii by detecting its content. The present invention can quickly distinguish the two strains of Agaricus eryngii strains, Agaricus leucophylla and Agaricus cyprinus. The present invention has the advantages of fast response speed, high sensitivity, simple operation, low cost, etc., and can quickly and high-throughput detect and distinguish Agaricus leucophylla, Agaricus cyprinus and Pleurotus eryngii spawn. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0028] Figure 1 This is the total ion current chromatogram of volatile components of Pleurotus eryngii, Pleurotus eryngii and Pleurotus ostreatus samples.

[0029] Figure 2 The principal component analysis diagram of 12 characteristic compounds in 12 samples of Pleurotus eryngii, Pleurotus eryngii and Pleurotus ostreatus strains. Δ is Pleurotus eryngii sample, ○ is Pleurotus eryngii sample, and □ is Pleurotus ostreatus sample.

[0030] Figure 3The principal component analysis diagram of three characteristic compounds in 12 samples of Pleurotus eryngii, Pleurotus eryngii and Pleurotus ostreatus strains. Δ is Pleurotus eryngii sample, ○ is Pleurotus eryngii sample, and □ is Pleurotus ostreatus sample. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0032] Prepare samples of Agaricus edulis and other edible mushrooms: Multiple freshly picked samples of Agaricus oleraceus, Agaricus rubrum, and Pleurotus eryngii were packaged and transported to the laboratory under refrigerated conditions to keep the samples fresh.

[0033] Headspace solid phase microextraction: Solid phase microextraction conditions: weigh 1 g of the crushed edible fungus sample into a 15 mL headspace bottle, add 10 μL of o-dichlorobenzene and 1 mL of distilled water and mix well, cover the bottle cap and place it in a 55 °C water bath for equilibration for 5 min, insert a 75 μm CAR23 / PDMS (carbon / polydimethyl siloxane) extraction head for headspace adsorption for 30 min, insert it into the GC-MS injection port after adsorption is completed, and analyze at 250 °C for 5 min.

[0034] GC-MS detection: A gas chromatography and time-of-flight mass spectrometry system was used, which consisted of an Agilent 7890B-5975C system and an HP-5ms nonpolar capillary column (60m×250μm×0.25μm; Agilent, USA). The detection was carried out at 250°C in splitless mode. The chromatographic separation program was as follows: the initial temperature of the program was 40°C, maintained for 3min; the temperature was increased to 70°C at a rate of 5°C / min and maintained for 0min; then the temperature was increased to 90°C at a rate of 2°C / min and maintained for 0min; then the temperature was increased to 210°C at a rate of 5°C / min and maintained for 0min. The carrier gas was high-purity helium (He) with a flow rate of 1.0mL / min. The mass spectrometer was operated under the conditions of a transfer line temperature of 220°C and an ion source of 200°C. The electron impact ionization was tuned to 70eV and the mass range was 45 to 500m / z. The total ion current spectrum of the edible fungus sample was obtained.

[0035] GC-MS data analysis: Qualitative analysis of volatile compounds: The standard mass spectra of the NIST11 standard spectral library of the Agilent MassHunter workstation were used to perform serial retrieval and manual analysis on the obtained spectral data. The aroma information was searched in combination with ChemicalBooks, and the matching degree greater than 80% was selected as the basis for substance identification. The relevant mass spectrometry data were compared, and the base peak, m / z and relative abundance were analyzed. The retention time and MS were combined to perform qualitative and quantitative analysis on the volatile components in the sample.

[0036] Quantitative analysis of volatile compounds: The peak area normalization method (internal standard method) was used for quantification to obtain the content of each component.

[0037] mi=f×Ai / (As / ms)

[0038] Ai and As are the peak areas or peak heights of the test sample and internal standard, respectively; ms is the amount of internal standard o-dichlorobenzene added; and mi is the amount of the test sample.

[0039] Evaluation of main volatile flavor substances. OAV is used to evaluate the contribution of each volatile component to the overall flavor of the sample. Under given conditions: OAV < 1, indicating that the component has no significant effect on the overall odor; OAV ≥ 1, indicating that the component may have a direct impact on the overall odor; and within a certain range, the larger the OAV value, the greater the contribution of the component to the overall odor. Calculate the OAV of each volatile component according to the following formula:

[0040] OAV=C / T

[0041] The relative concentration of each compound was calculated by peak area normalization method, C was defined as the absolute concentration of the olfactory substance, and T was its sensory threshold.

[0042] The main odor active compounds in a specific strain that have an important influence on the overall aroma are determined. The content of volatile compounds in a specific strain determined by GC-MS and their OAV values ​​are comprehensively analyzed and compared for the detected multiple volatile compounds to identify the characteristic odor molecules that significantly contribute to the aroma of a specific edible fungus. The present invention sets the absolute content value and OAV value of this group of compounds as the evaluation criteria for a specific edible fungus species.

[0043] Principal component analysis: Statistical analysis was performed by one-way analysis of variance (ANOVA) using Origin version 9.0 software (OriginLab Co., Northampton, MA) to determine significant differences between different samples. The present invention performed principal component analysis (PCA) based on the determined contents and OAV values ​​of multiple specific Agrocybe aegypti characteristic compounds to highlight the differences between Agrocybe aegypti strains and other edible fungi.

[0044] Embodiment 1:

[0045] Preparation of edible fungi samples for GC-MS detection: Fresh fruiting body fragments of Pleurotus eryngii, Pleurotus eryngii, and Pleurotus ostreatus were taken and labeled as Pleurotus eryngii strain (Pleurotus eryngii), Pleurotus eryngii strain (Pleurotus eryngii), and Pleurotus ostreatus strain (Pleurotus ostreatus), respectively. The volatile compounds of the fruiting bodies were detected three times in parallel using headspace solid-phase microextraction (HS-SPME) enrichment method and gas chromatography-mass spectrometry (GC-MS) coupling method, using Agilent 7890B-5975C system and HP-5ms non-polar capillary column (60m×250μm×0.25μm; Agilent, USA) as detection equipment. The total ion spectra of the three strains including Pleurotus eryngii and Pleurotus ostreatus samples are shown in Figure 1. Figure 1 As shown. The chromatographic separation program was set as follows: the initial temperature of the program was 40°C, maintained for 3 min; the temperature was increased to 70°C at a rate of 5°C / min, maintained for 0 min; the temperature was increased to 90°C at a rate of 2°C / min, maintained for 0 min; the temperature was then increased to 210°C at a rate of 5°C / min, maintained for 0 min. The carrier gas was high-purity helium (He) with a flow rate of 1.0 mL / min. The mass spectrometer was operated at a transfer line temperature of 220°C and an ion source of 200°C. The electron impact ionization was tuned to 70 eV, and the mass range was 45 to 500 m / z.

[0046] The volatile compounds in the three edible fungi samples were quantified by GC-MS detection and the internal standard method with o-dichlorobenzene standard as the reference. The average content of the compounds in each edible fungi sample is shown in Table 1. There are 43 aroma compounds in Pleurotus eryngii strain (Pleurotus eryngii), accounting for 80.62% of the total volatile components. The contents of 29 aroma compounds in Pleurotus eryngii strain (Pleurotus eryngii) and Pleurotus ostreatus strain (Pleurotus ostreatus) are significantly higher than those in Pleurotus eryngii strain (Pleurotus eryngii). The volatile compounds in the three edible fungi samples were quantified by the peak area normalization method (internal standard method) with o-dichlorobenzene standard as the reference. The contents of volatile aroma compounds in three different species of edible fungi samples (average values ​​in three samples) are shown in Table 1.

[0047] Calculate the OAV value to determine the type of characteristic volatile aroma compounds. Determine the main volatile flavor substances by calculating the OAV value. The number of volatile aroma substances detected by GC-MS is relatively large, including some volatile compounds that do not have a significant effect on the flavor of edible fungi. Among them, the content and OAV value of 12 characteristic aroma components in the No. 2 (white jade mushroom) and No. 3 (shimeji mushroom) strain samples (4 different parallel samples of each edible fungus were taken for detection) are relatively high, and the OAV values ​​are all greater than 1, which are considered to be characteristic odor molecules that contribute significantly to the aroma of this edible fungus. The types of edible fungi are distinguished by principal component analysis of characteristic aroma compounds. Principal component analysis: SPSS 19.0 data processing software was used to prepare the principal component analysis graph of 12 samples of three strains. The present invention excludes non-main volatile flavor substances when performing principal component analysis, and only performs orthogonal transformation and dimensionality reduction on the OAV values ​​of the 12 characteristic aroma substances determined in step three in each sample to form a PCA graph of the three edible fungi samples ( Figure 2 ). The principal component analysis method was used to analyze the data of characteristic aroma substances to achieve rapid differentiation of edible fungus samples.

[0048] Through OAV value calculation, 12 compounds were found to be characteristic volatile aroma compounds that have important contributions to the aroma of Agaricus sphaerocephala, namely: 1-octen-3-ol (1), 3-octanone (2), benzaldehyde (3), trans-2-octenal (4), 3-octanol (5), 1-octen-3-one (6), n-octanal (7), 1-nonanol (8), nonanal (11), n-heptanol (20), trans-2-nonenal (21), and (2E, 4E)-2,4-octadienal (22).

[0049] Table 1 Contents and OAV values ​​of volatile aroma compounds in samples of three different species of edible fungi

[0050]

[0051]

[0052]

[0053]

[0054]

[0055] According to the above method, more fresh Pleurotus eryngii, Pleurotus eryngii and Pleurotus ostreatus were collected to repeat the above experiment. The content of characteristic volatile aroma compounds in Pleurotus eryngii and Pleurotus ostreatus was significantly different. According to GC-MS determination, the total content of 12 characteristic aroma compounds in Pleurotus eryngii strains was 0.27-0.5μg / g, the total content of 12 characteristic compounds in Pleurotus eryngii strains was 2.5-3.7μg / g, and the total content of 16 characteristic compounds in Pleurotus ostreatus strains was 5.3-6.7μg / g.

[0056] According to Table 1, we further selected compounds with significantly different contents in Pleurotus eryngii and Pleurotus ostreatus. The criteria for selecting compounds were that the OAV values ​​of the compounds in Pleurotus eryngii and Pleurotus ostreatus were both greater than 500, and the content of the compounds in Pleurotus ostreatus was greater than that in Pleurotus eryngii. Based on this principle, we selected three compounds: 1-octen-3-ol, 3-octanone, and 1-octen-3-one, which had significantly different contents in the three strains. The OAV values ​​of the above three characteristic aroma substances in each sample were orthogonally transformed and dimensionally reduced to form a PCA graph of the three edible fungi samples, which can further distinguish Pleurotus ostreatus samples from Pleurotus eryngii samples ( Figure 3 ). The average ratio of 1-octen-3-ol in Pleurotus eryngii and Pleurotus ostreatus is 1:2.14 (Pleurotus eryngii strain: Pleurotus ostreatus strain); the average ratio of 3-octanone in Pleurotus eryngii and Pleurotus ostreatus is 1:1.88 (Pleurotus eryngii strain: Pleurotus ostreatus strain); the average ratio of 1-octen-3-one in Pleurotus eryngii and Pleurotus ostreatus is 1:2.77 (Pleurotus eryngii strain: Pleurotus ostreatus strain). The contents of these three compounds in Pleurotus eryngii and Pleurotus ostreatus are more than 6 times that of Pleurotus eryngii.

[0057] 1-Octen-3-ol, 3-octanone, trans-2-octenal, and 1-octen-3-one were retained as the identity characteristic flavor components of Pleurotus eryngii and Pleurotus ostreatus. Different batches of commercially available and self-cultivated Pleurotus eryngii, Pleurotus eryngii, and Pleurotus ostreatus were collected to repeat the above experiment. The experimental results were consistent with Table 1.

[0058] According to Table 1, it was found that trans-2-nonenal (21) had a high degree of differentiation in Pleurotus eryngii, Pleurotus eryngii and Pleurotus ostreatus. The compound was difficult to detect in Pleurotus eryngii. The OAV values ​​in Pleurotus eryngii and Pleurotus ostreatus were both greater than 1, which was a characteristic compound. The average OAV ratio of Pleurotus eryngii to Pleurotus ostreatus was 7.5. According to statistics, the OAV ratio of trans-2-nonenal (21) in Pleurotus eryngii to Pleurotus ostreatus was greater than 5.

[0059] In addition, the content and OAV of compound 3-methylbutanal (24) in Oyster mushroom were very low and difficult to detect, but it could be detected in Pleurotus eryngii and Pleurotus eryngii, and the OAV was greater than 1.

[0060] The invention can distinguish the mushroom blocks of Pleurotus eryngii, Pleurotus eryngii and Pleurotus ostreatus through volatile characteristic aroma compounds.

[0061] The chromatographic and mass spectrometric conditions of the above 12 characteristic aroma compounds are:

[0062] Gas chromatography conditions:

[0063] Chromatographic column: Agilent HP-5ms column, 60m×250μm×0.25μm

[0064] Flow rate: 1.0mL / min

[0065] Chromatographic separation procedure:

[0066]

[0067] Mass spectrometry conditions:

[0068]

[0069]

[0070] GC-MS qualitative analysis results of characteristic aroma compounds of Agaricus sphaerocephala:

[0071]

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for distinguishing Agaricus spp. strains by volatile characteristic aroma compounds, characterized in that: It consists of the following steps: Headspace solid phase microextraction: Weigh the edible fungus fruiting body block sample, place it in a headspace bottle, add o-dichlorobenzene and water, insert the extraction head for headspace adsorption, and insert it into the GC-MS injection port; GC-MS detection: The detection was carried out at 250°C in splitless mode to obtain the total ion current spectrum of the edible mushroom block sample; GC-MS data analysis: The obtained spectral data were retrieved in series and manually analyzed using the standard mass spectra of the NIST 11 standard spectral library of the Agilent MassHunter workstation. The aroma information was searched in combination with ChemicalBooks. The base peak, m / z and relative abundance were analyzed. The volatile components in the sample were qualitatively and quantitatively analyzed in combination with retention time and MS. The peak area normalization method was used for quantification to obtain the content of each component. Evaluation of main volatile flavor substances: OAV is used to evaluate the contribution of each volatile component to the overall flavor of the sample, and the multiple volatile compounds detected are analyzed and compared to identify the characteristic odor molecules that have a significant contribution to the aroma of specific edible fungi; Principal component analysis: Principal component analysis is performed based on the content and OAV value of characteristic odor molecules; The agaricus strains are Pleurotus eryngii and Pleurotus ostreatus; The GC-MS detection was performed using an Agilent HP-5ms column, and the chromatographic separation procedure was as follows: the initial temperature of the program was 40°C, maintained for 3 min; the temperature was increased to 70°C at a rate of 5°C / min, maintained for 0 min; the temperature was then increased to 90°C at a rate of 2°C / min, maintained for 0 min; the temperature was then increased to 210°C at a rate of 5°C / min, maintained for 0 min, and the carrier gas was high-purity helium at a flow rate of 1.0 mL / min; The GC-MS has a retention time of 28.0879 min for 1-octen-3-ol, 20.5767 min for 3-octanone, 30.8171 min for benzaldehyde, 27.6575 min for trans-2-octenal, 26.0821 min for 3-octanol, 22.6821 min for 1-octen-3-one, 22.1278 min for n-octanal, 34.142 min for 1-nonanol, 26.3158 min for nonanal, 28.2175 min for n-heptanol, 31.0582 min for trans-2-nonenal, and 31.8206 min for (2E,4E)-2,4-octadienal. The GC-MS mass spectrometer operating conditions are: the transmission line temperature is 220°C, the ion source is 200°C, the electron impact ionization is tuned to 70 eV, the mass range is 45 to 500 m / z, and the total ion current spectrum of the edible mushroom block sample is obtained; The volatile characteristic aroma compounds are composed of 12 compounds, namely: 1-octen-3-ol, 3-octanone, benzaldehyde, trans-2-octenal, 3-octanol, 1-octen-3-one, n-octanal, 1-nonanol, nonanal, n-heptanol, trans-2-nonenal, (2E, 4E)-2,4-octadienal, and the OAV values ​​of the 12 compounds in the Agrocybe spp. strain are all greater than 1; among them, the OAV values ​​of 1-octen-3-ol, 3-octanone and 1-octen-3-one are all greater than 500; The OAV ratio of trans-2-nonenal in Oyster mushroom and Pleurotus eryngii was greater than 5; the content of 3-methylbutyraldehyde in Oyster mushroom was <0.002 μg / g, OAV<0.1; the OAV of 3-methylbutyraldehyde in Pleurotus eryngii was >1; The headspace solid phase microextraction is to weigh 1g of the crushed edible fungus block sample, place it in a headspace bottle, add 10μL of o-dichlorobenzene and 1mL of distilled water, mix them evenly, cover the bottle cap and place it in a 55°C water bath for equilibration for 5min, insert the extraction head for headspace adsorption for 30min, then insert it into the GC-MS injection port and analyze it at 250°C for 5min.

2. The method for distinguishing Agaricus spp. strains by volatile characteristic aroma compounds according to claim 1, characterized in that: The peak area normalization method is used for quantification, and the calculation formula is: mi=f×Ai / (As / ms) Wherein, Ai and As are the peak areas or peak heights of the sample to be tested and the internal standard, respectively; ms is the mass of the added internal standard; and mi is the mass of the sample to be tested.

3. The method for distinguishing Agaricus spp. strains by volatile characteristic aroma compounds according to claim 1 or 2, characterized in that: The OAV is used to evaluate the contribution of each volatile component to the overall flavor of the sample. The OAV calculation formula is: OAV=C / T Among them, C is the absolute concentration of the olfactory substance, T is its sensory threshold; OAV < 1 indicates that the component has no significant effect on the overall odor; OAV ≥ 1 indicates that the component has an effect on the overall odor.

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