Meat flavor substance detection method and application

Abstract

The invention belongs to the field of flavor substance detection and analysis, and particularly relates to a meat flavor substance identification method which comprises the following steps: (1) HS-SPME and condition design; (2) sample testing; and (3) data analysis. The identification method disclosed by the invention can be used for identifying and analyzing the volatile flavor substances in the meat, extracting the volatile substances in the meat and quickly separating, identifying and analyzing the volatile substances.

Description

Technical Field

[0001] The present invention belongs to the field of detection and analysis of flavor substances, and particularly relates to a method for identifying meat flavor substances and its application. Background Art

[0002] Flavor is a key factor affecting the choice of meat consumers and determines whether consumers will buy again. Flavor substances are mainly composed of aldehydes, ketones, and alcohols. There are many types of volatile substances, with complex structures and rich molecules, resulting in difficulties in their analysis and identification. In addition, the identification of meat flavor substances is not only related to the content, but also closely related to its extraction and analysis methods. Currently, commonly used flavor detection instruments on the market include Electronic Nose (EN), Gas Chromatography - Mass Spectrometry (GC - MS), Headspace Solid Phase Microextraction Gas Chromatography Mass Spectrometry (HS - SPME - GC - MS), Gas Chromatography Olfactometry Mass Spectrometry (GC - O - MS), and Gas Chromatography Ion Mobility Spectrometry (GC - IMS). Among them, EN is simple to operate, convenient and fast, but affected by the environment and does not have the ability of separation and identification. GC - MS performs chemical and objective determinations, identifies individual substances and comprehensive volatile information, but the identification and quantification of co - distilled substances are inaccurate. HS - SPME - GC - MS has simple sample preparation, avoids high - boiling - point matrices, reduces mass spectrometry contamination, and reduces the accumulation of pretreatment errors; however, its detection range is narrow and the detection cycle is long. GC - O - MS provides comprehensive aroma composition information and identifies individual compounds; it relies on human senses and cannot be automated. GC - IMS requires no sample pretreatment, has simple operation, stable results, fast response, and high sensitivity, but the detected substances are limited and are low - molecular - mass volatile substances. Therefore, there is a need in the art for a detection method for meat flavor substances with low detection limit, good separation effect, high - speed data acquisition ability, and high sensitivity to ensure high - density and high - throughput analysis information. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for detecting meat flavor substances and its application, which can identify and analyze meat volatile flavor substances, extract meat volatile substances, and quickly separate, identify, and analyze volatile substances.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows: Design a method for identifying meat flavor substances, including the following steps: (1) HS-SPME conditions: Take 2 g of the sample, place it in a 20 mL headspace vial, add 3 g of saturated NaCl solution, and start extraction after equilibration for 10 min at 80 °C and 500 r / min. The extraction time is 40 min; after extraction, desorb at the inlet of the injector at 250 °C for 5 min.

[0005] (2) Sample testing: Analyze the gas sample obtained in step (1) by using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF-MS) in series;

[0006] The gas chromatography conditions are as follows: The first-dimensional chromatographic column is DB-WAX, 30 m, 250 μm I.D, 0.5 μm; The second-dimensional chromatographic column is Rx-17 Si, 2.0 m, 150 μm I.D, 0.15 μm; High-purity helium (He) is used as the carrier gas (purity ≥ 99.999%), and the constant flow rate is 1.0 mL / min; The injection temperature is 250 °C; The conditions of the first-dimensional chromatographic column are: The initial temperature is 50 °C, lasting for 2 minutes, rising to 220 °C at a rate of 4 °C / min, and holding for 13 minutes; The temperature programming of the second-dimensional chromatographic column is 5 °C higher than that of the first-dimensional chromatographic column, the modulator temperature is always 15 °C higher than the column temperature of the second-dimensional chromatographic column, and the modulation period is 5.0 s.

[0007] The mass spectrometry conditions are: The temperature and voltage of the ion source are 70 eV and 250 °C respectively; The transfer line temperature is 250 °C; The detector voltage is 2020 V; The ion scanning range is 35 - 550 amu; The scanning frequency is 100 spectra / s.

[0008] (3) Data analysis: The TOF / MS data collected from the experiment was processed by the Chroma TOF workstation of LECO Corporation in the United States. Chromatographic peaks with a signal-to-noise ratio greater than 50 were automatically identified, and the mass spectrometry library was automatically compared. After deconvolution, it was compared with NIST 2020 and Wiley 9, and compounds with a mass spectrometry similarity less than 800 were excluded. Some compounds such as amines, nitriles, and alkanes in the blank control background were excluded as the preliminary identification results. Compounds without flavor contribution such as alkanes were removed, and compounds with a similarity and reverse similarity both > 700 and a probability > 4000 were selected. Excel 2010 and GraphPad Prism 10 software were used for data processing and graphing.

[0009] The present invention has the following positive and beneficial effects: The present invention provides a method for identifying meat flavor substances and its application. This method is based on the GC×GC-TOM-MS technology, which combines two-dimensional gas chromatography-mass spectrometry with time-of-flight mass spectrometry. It has a low detection limit, good separation effect, high-speed data acquisition ability and high sensitivity, ensuring high density and high throughput of analysis information. This method can be used in the fields of meat food flavor analysis, quality identification, origin traceability, grade differentiation, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 For the volatile substance maps and sensory flavors in donkey meat and horse meat; Figure 2 For the differential volatile substances and flavor characteristics in donkey meat and horse meat. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be further described below in conjunction with the drawings and embodiments, but the embodiments of the present invention are not limited thereto. Embodiment

[0012] A method for identifying meat flavor substances includes the following steps: (1) HS-SPME conditions: Take 2 g of the sample, place it in a 20 mL headspace vial, add 3 g of saturated NaCl solution, and start extraction after equilibration at 80 °C and 500 r / min for 10 min. The extraction time is 40 min; after extraction, desorb at the inlet of the injector at 250 °C for 5 min.

[0013] (2) Sample testing: Analyze the gas sample obtained in step (1) by using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF-MS) in series;

[0014] The gas chromatography conditions are as follows: the first-dimensional chromatographic column is DB-WAX, 30 m, 250 μm I.D, 0.5 μm; The second-dimensional chromatographic column is Rx-17 Si, 2.0 m, 150 μm I.D, 0.15 μm; High-purity helium (He) is used as the carrier gas (purity ≥ 99.999%), and the constant flow rate is 1.0 mL / min; The injection temperature is 250 °C; The conditions of the first-dimensional chromatographic column are: the initial temperature is 50 °C, lasting for 2 minutes, rising to 220 °C at a rate of 4 °C / min, and holding for 13 minutes; The temperature programming of the second-dimensional chromatographic column is 5 °C higher than that of the first-dimensional chromatographic column. The modulator temperature is always 15 °C higher than the column temperature of the second-dimensional chromatographic column, and the modulation period is 5.0 s.

[0015] The mass spectrometry conditions are: the ion source temperature voltage is 70 eV, and the temperature is 250 °C; The transfer line temperature is 250 °C; The detector voltage is 2020 V; The ion scanning range is 35 - 550 amu; The scanning frequency is 100 spectra / s.

[0016] (3) Data analysis: The TOF / MS data collected in the experiment are processed by the Chroma TOF workstation of LECO Corporation in the United States. Chromatographic peaks with a signal-to-noise ratio greater than 50 are automatically identified, and the mass spectrometry library is automatically compared. After deconvolution, it is compared with NIST 2020 and Wiley 9, and compounds with a mass spectrometry similarity less than 800 are excluded. Some compounds such as amines, nitriles, and alkanes in the blank control background are excluded as the preliminary identification results. Compounds without flavor contribution such as alkanes are removed, and compounds with a similarity and reverse similarity both > 700 and a possibility > 4000 are selected. Excel 2010 and GraphPad Prism10 software are used for data processing and graphing.

[0017] The above-mentioned embodiments merely illustrate several specific implementation manners of the present invention, rather than limiting the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without creative efforts, different improvements can be made based on these drawings to obtain other drawings, and all of these fall within the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. A method for identifying meat flavor substances, characterized in that: The following steps are involved: (1) HS-SPME and condition design; (2) Sample testing; (3) Data analysis.

2. The authentication method according to claim 1, wherein: The HS-SPME conditions were as follows: 2 g of sample was placed in a 20 mL headspace vial, 3 g of saturated NaCl solution was added, and the sample was equilibrated at 80 °C and 500 r / min for 10 min before extraction, with an extraction time of 40 min. After extraction, the sample was analyzed at the front inlet at 250 °C for 5 min.

3. The identification method according to claim 1, characterized in that: The sample testing conditions are as follows: the gas sample obtained in step (1) is analyzed by using a comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry coupled in series.

4. The authentication method according to claim 3, wherein: Gas chromatography conditions are: The first-dimension column was DB-WAX, 30 m, 250 μm ID, 0.5 μm; The second-dimension column was Rx-17 Si, 2.0 m, 150 μm ID, 0.15 μm; High-purity helium (He) was used as the carrier gas (purity ≥99.999%) at a constant flow rate of 1.0 mL / min; The injection temperature was 250°C; The first-dimensional column conditions were as follows: initial temperature of 50 °C for 2 min, increased to 220 °C at a rate of 4 °C / min, and held for 13 min; The temperature program of the 2D column was 5 °C higher than that of the 1D column, the modulator temperature was always 15 °C higher than that of the 2D column, and the modulation period was 5.0 s.

5. The authentication method according to claim 3, wherein: Mass spectrometry conditions are: The ion source temperature voltage was 70 eV and the temperature was 250 °C; The transmission line temperature is 250 °C; The detector voltage is 2020 V; The ion scan range was 35–550 amu; The scanning frequency is 100 spectra / s.

6. The authentication method according to claim 1, wherein: Step (3) The TOF / MS data collected in the experiment were processed by a Chroma TOF workstation from LECO, USA. Chromatographic peaks with a signal-to-noise ratio greater than 50 were automatically identified and compared with the mass spectral library. After deconvolution, the data were compared with NIST 2020 and Wiley 9, and compounds with mass spectral similarity less than 800 were eliminated. Some compounds in the blank control background, such as amines, nitriles, and alkanes, were eliminated as preliminary identification results. Compounds that did not contribute to flavor, such as alkanes, were removed, and compounds with similarity and anti-similarity greater than 700 and probability greater than 4,000 were selected. Excel 2010 and GraphPad Prism 10 software were used for data processing and plotting.

7. Use of the identification method according to any one of claims 1 to 6 in the rapid identification or analysis of volatile substances in meat.

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