A method for screening and identifying characteristic flavor substances of Pingliang red cattle

Abstract

The application discloses a kind of screening and identification method of Pingliang red cattle characteristic flavor substance, belong to Pingliang red cattle detection technical field.A kind of screening and identification method of Pingliang red cattle characteristic flavor substance, comprising: Pingliang red cattle muscle sample is sterile pretreatment;Extract volatile flavor substance and obtain stock solution;Eliminate general interfering substance, preliminary screen candidate flavor substance;Complete flavor quality grading.The application solves the problem that prior art cannot eliminate general flavor interference, lacks flavor substance content threshold determination system, the application accurately locks the core flavor substance of Pingliang red cattle by database comparison and multiple batches specificity verification, solves the problem of poor pertinence, many interference of traditional screening, relies on sample detection data to establish flavor quantification threshold and proportion grading system, breaks through only qualitative and not quantitative short board, divides quality grade, can distinguish inferior products, fills the blank of flavor quantification identification, improves practical and industrial value.

Description

Technical Field

[0001] This invention relates to the field of Pingliang Red Bull detection technology, specifically a method for screening and identifying characteristic flavor substances of Pingliang Red Bull. Background Technology

[0002] Pingliang Red Cattle is a unique and superior local breed of beef cattle in Pingliang, Gansu Province, my country. It is a national geographical indication agricultural product and has become one of the core representatives of high-end beef products in China due to its tender meat, rich aroma, unique flavor, and balanced nutrition.

[0003] Chinese Patent Publication No. CN109696501A discloses a method for identifying characteristic volatile flavor substances in meat or meat products, comprising the following steps: Step 1, extracting volatile flavor substances from meat or meat products and detecting the concentration of each component; Step 2, calculating the odor activity value and contribution rate of each component; Step 3, selecting N components with a cumulative contribution rate greater than a preset value a and an odor activity value greater than a preset value b; Step 4, preparing a recombinant model 1 by taking standard samples of the N components and mixing them with a meat or meat product matrix, deleting one of the N components and then preparing a recombinant model 2 by mixing it with the meat or meat product matrix, comparing the flavors of recombinant model 1 and recombinant model 2, and identifying the component that causes the flavor difference as the characteristic volatile flavor substance of meat or meat products.

[0004] The aforementioned patents have poor flavor screening targeting in actual use, cannot eliminate interference from general flavors, are difficult to identify the unique flavor substances of Pingliang Red Bull, lack a flavor substance content threshold determination system, and cannot achieve quantitative grading of the flavor quality of Pingliang Red Bull; therefore, they do not meet the existing needs. In response, we propose a screening and identification method for the characteristic flavor substances of Pingliang Red Bull. Summary of the Invention

[0005] The purpose of this invention is to provide a method for screening and identifying characteristic flavor substances of Pingliang Red Beef. By comparing data with a database to eliminate common interfering substances and then conducting multiple batches of specific verification to eliminate occasional interference, the method accurately identifies its core flavor substances, including terpenes, unsaturated alcohols, and characteristic esters. This solves the problems of weak targeting and mixed interference in existing screening methods, significantly improving screening accuracy. Simultaneously, based on standardized sample testing data, a quantitative threshold and ratio grading system for characteristic flavor substances is established, determining the effective threshold, optimal content range, and component ratio standards for core flavor substances. This overcomes the limitation of existing technologies that can only qualitatively identify but not quantitatively grade flavor substances. Furthermore, the method classifies flavor quality grades, accurately identifying different breeding qualities and counterfeit or inferior Pingliang Red Beef products, filling the technical gap in the quantitative identification of flavor quality, enhancing the practicality and industrial value of the technology, and solving the problems mentioned in the background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for screening and identifying characteristic flavor substances of Pingliang Red Bull, comprising the following steps:

[0007] S1: Collect standardized Pingliang Red Beef muscle samples, perform aseptic pretreatment on the Pingliang Red Beef muscle samples to remove surface fat, fascia and blood clots, and obtain pure muscle test samples.

[0008] S2: Extract flavor substances from the pure muscle test sample to enrich all volatile flavor substances in the sample and obtain the flavor extract stock solution.

[0009] S3: Construct a Pingliang Red Cattle exclusive flavor screening database, and eliminate common meat flavor interfering substances by comparing and eliminating the Pingliang Red Cattle exclusive flavor screening database to initially screen out candidate characteristic flavor substances of Pingliang Red Cattle.

[0010] S4: Conduct specific verification and screening of candidate characteristic flavor substances, eliminate occasional flavor substances that are not exclusive to Pingliang Red Bull, and determine the list of core characteristic flavor substances of Pingliang Red Bull.

[0011] S5: Based on the preset threshold and ratio standards for the content of characteristic flavor substances of Pingliang Red Bull, quantitative identification and flavor quality grading of core characteristic flavor substances are carried out to complete the screening and identification of characteristic flavor substances of Pingliang Red Bull.

[0012] Preferably, the aseptic pretreatment specifically includes: rinsing the original sample surface with sterile physiological saline to remove residual impurities, rinsing 2-3 times; after rinsing, absorbing the moisture from the sample surface with sterile filter paper; removing the white fat layer, dense fascia, and dark congested tissue from the sample surface in a sterile ultra-clean workbench, retaining only the fresh red muscle main body tissue; chopping the muscle into meat particles with a particle size of 3-5 mm to obtain a pure muscle test sample; the pretreatment temperature is controlled at 0-4℃ throughout the process, and the pretreatment time does not exceed 15 minutes.

[0013] Preferably, the flavor substance extraction process employs headspace solid-phase microextraction (HS-SPME). The specific operation includes: weighing 5-8g of pure muscle test sample and placing it in a headspace extraction bottle, sealing the extraction bottle, and placing it in a constant temperature water bath environment for equilibration for 15-20 minutes. Then, inserting the solid-phase microextraction head and performing headspace adsorption extraction for 30-40 minutes, with the extraction temperature stabilized at 55-60℃. After extraction, removing the extraction head and thermally desorbing the sample to obtain the flavor extract stock solution, which contains all volatile and semi-volatile flavor substances in the sample.

[0014] Preferably, the construction method of the Pingliang Red Cattle exclusive flavor screening database is as follows: collect flavor test data of multiple batches of standardized Pingliang Red Cattle, ordinary yellow cattle, crossbred beef cattle and other types of livestock and poultry meat, summarize the common flavor substances common to various types of meat and the flavor substances unique to Pingliang Red Cattle, classify and enter them to form the Pingliang Red Cattle exclusive flavor screening database, which includes a general flavor substance library and a Pingliang Red Cattle exclusive flavor substance library. The general flavor substance library includes basic flavor substances such as alkanes and conventional aldehydes commonly found in various types of meat, and the Pingliang Red Cattle exclusive flavor library includes flavor substances such as terpenes, unsaturated alcohols and characteristic esters unique to Pingliang Red Cattle.

[0015] Preferably, the step of removing common flavor interfering substances in meat by comparing with the database specifically involves: importing the substance detection data of the flavor extract into a dedicated flavor screening database, comparing the detected flavor substances one by one, marking the components that match the common flavor substance library as interfering substances and removing them directly, and retaining the components that only match the Pingliang Red Bull dedicated flavor substance library as candidate characteristic flavor substances for Pingliang Red Bull, thus completing the preliminary screening.

[0016] Preferably, the specificity verification screening specifically includes: selecting standardized Pingliang Red Cattle samples from different breeding cycles and different breeding batches for repeated testing, while selecting ordinary beef cattle and other livestock and poultry meat samples for control testing, and statistically analyzing the detection rate and specificity of each candidate characteristic flavor substance.

[0017] Preferably, the criteria for the specificity verification screening are as follows: candidate substances with a detection rate of not less than 95% in multiple batches of Pingliang Red Cattle samples and a detection rate of less than 5% in ordinary beef and other livestock and poultry meat samples are identified as core characteristic flavor substances exclusive to Pingliang Red Cattle; candidate substances with a detection rate of less than 90% in Pingliang Red Cattle samples or frequently detected in other meats are identified as occasional interfering substances and removed, and finally a list of core characteristic flavor substances of Pingliang Red Cattle is obtained.

[0018] Preferably, the preset threshold and ratio standard for the content of characteristic flavor substances of Pingliang Red Bull are obtained by statistical fitting of flavor test data from multiple batches of high-quality Pingliang Red Bull, specifically including the minimum effective content threshold, optimal content range and multi-component synergistic ratio of each core characteristic flavor substance.

[0019] Preferably, the quantitative identification specifically involves: using gas chromatography-mass spectrometry to quantitatively detect the core characteristic flavor substances, obtaining the actual content and component ratio data of each core characteristic flavor substance, and comparing the actual detection data with preset content thresholds and ratio standards one by one.

[0020] Preferably, the flavor quality grading specifically includes three levels: excellent, qualified, and unqualified. When the actual content of all core characteristic flavor substances is within the optimal content range and the composition ratio meets the standard ratio, the sample is judged to be of excellent Pingliang Red Bull flavor grade. When the actual content of all core characteristic flavor substances is higher than the minimum effective content threshold, but not all reach the optimal range, and the composition ratio deviation is within the allowable range, the sample is judged to be of qualified Pingliang Red Bull flavor grade. When the actual content of any core characteristic flavor substance is lower than the minimum effective content threshold, or the composition ratio deviation exceeds the allowable range, the sample is judged to be of unqualified Pingliang Red Bull flavor grade.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. This invention constructs a Pingliang Red Cattle-specific flavor screening database to accurately distinguish between general meat flavor substances and Pingliang Red Cattle-specific flavor substances. This completely solves the shortcomings of existing general screening technologies, such as poor targeting and mixed interfering substances. By building the Pingliang Red Cattle-specific flavor screening database and dividing it into a general flavor library and a Pingliang Red Cattle-specific flavor library, invalid general interfering substances are directly eliminated through database comparison. Combined with multiple batches of specific verification screening, occasional interfering substances are completely eliminated, and the core flavor substances of Pingliang Red Cattle, such as terpenes, unsaturated alcohols, and characteristic esters, are accurately identified, greatly improving the screening accuracy.

[0023] 2. This invention establishes a comprehensive quantitative threshold and ratio grading system for characteristic flavor substances, overcoming the shortcomings of existing technologies that can only qualitatively identify but not quantitatively grade them. This significantly improves the practicality and industrialization value of the technology. Based on a large amount of standardized Pingliang Red Cattle sample testing data, this application establishes the minimum effective threshold, optimal content range, and component ratio standards for core characteristic flavor substances, achieving accurate quantitative identification of flavor substances. At the same time, it divides the flavor quality into three grades: high-quality, qualified, and unqualified, which can accurately distinguish Pingliang Red Cattle products of different breeding qualities and flavor grades, effectively identifying counterfeit and inferior Pingliang Red Cattle beef products, and filling the technical gap in the quantitative identification of Pingliang Red Cattle flavor quality. Attached Figure Description

[0024] Figure 1 This is a flowchart of a method for screening and identifying characteristic flavor substances of Pingliang Red Bull according to the present invention.

[0025] Figure 2 Flowchart for determining the list of core characteristic flavor substances of Pingliang Red Bull according to the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To address the shortcomings of existing technologies in practical application, such as poor flavor screening targeting, inability to eliminate common flavor interference, difficulty in identifying the unique flavor compounds specific to Pingliang Red Bull, lack of a flavor compound content threshold determination system, and inability to quantify and grade the flavor quality of Pingliang Red Bull, please refer to [link to relevant documentation]. Figures 1-2 This embodiment provides the following technical solution:

[0028] A method for screening and identifying characteristic flavor compounds of Pingliang Red Beef, comprising the following steps:

[0029] S1: Collect standardized Pingliang Red Cattle muscle samples and complete aseptic pretreatment to obtain pure muscle test samples; specifically, select Pingliang Red Cattle that are 18-24 months old, healthy and disease-free, and fed according to uniform standards in the core breeding area of ​​Pingliang, select the core meat parts of the longissimus dorsi and gluteus maximus muscles, collect fresh muscle tissue that is free from blood stasis, spoilage, and uniform color, and control the weight of each sample to 80-120g. After sampling, immediately seal and store at low temperature to prevent the volatilization and oxidation of flavor substances. Then, in a sterile ultra-clean environment at 0-4℃, rinse the sample 2-3 times with sterile physiological saline, absorb the surface moisture with sterile filter paper, thoroughly remove fat, fascia, blood stasis and impurities, and cut into uniform meat particles of 3-5mm. The entire pretreatment time is controlled within 15 minutes to obtain pure muscle test samples;

[0030] S2: Extract flavor substances from the pure muscle test sample to prepare flavor extract stock solution; specifically, weigh 5~8g of pure muscle test sample, place it in a headspace extraction bottle and seal it, place it in a constant temperature water bath environment of 55~60℃ for equilibration for 15~20min to allow the flavor substances to be fully released, and then use solid phase microextraction head headspace adsorption extraction for 30~40min. After extraction, thermal desorption enriches all volatile and semi-volatile flavor substances to obtain a flavor extract stock solution with complete components.

[0031] S3: Construct a flavor screening database specific to Pingliang Red Cattle. Through database comparison, common meat flavor interfering substances are eliminated, and candidate characteristic flavor substances are screened. Specifically, this involves collecting flavor testing data from multiple batches of standardized Pingliang Red Cattle, ordinary yellow cattle, hybrid beef cattle, pork, chicken, and mutton, etc., and constructing a common flavor substance library and a Pingliang Red Cattle-specific flavor substance library. The common flavor substance library includes basic flavor substances such as alkanes and conventional aldehydes common to various meats, while the specific flavor substance library includes terpenes, unsaturated alcohols, and characteristic esters unique to Pingliang Red Cattle. The full-component detection data of the flavor extract is imported into the database, and each component is compared. Interfering substances matching the common flavor library are eliminated, and the specific flavor components are retained to obtain a set of candidate characteristic flavor substances.

[0032] S4: Conduct specific multi-level verification and screening of candidate characteristic flavor substances, eliminate non-specific incidental substances, and determine the list of core characteristic flavor substances; through repeated testing of multiple batches of Pingliang Red Cattle samples and comparative testing of multiple types of livestock and poultry meat, calculate the detection rate and breed specificity of each candidate substance, and screen the core characteristic flavor substances of Pingliang Red Cattle according to the preset specific judgment criteria.

[0033] S5: Based on the preset flavor substance content thresholds and proportion standards, the core characteristic flavor substances are quantitatively identified and their flavor quality is graded. Quantitative detection is completed using gas chromatography-mass spectrometry to obtain the actual content and composition ratio data of each substance. The data are then compared with the preset minimum effective content threshold, optimal content range, and standard proportion to complete the three-level flavor quality grading.

[0034] In a preferred embodiment, the S4 candidate characteristic flavor substance specificity verification and screening adopts a multi-level threshold verification mechanism to eliminate unqualified candidate substances step by step and accurately lock the variety-specific flavor substances. Specifically, it includes interference elimination verification, Pingliang Red Bull sample stability verification, cross-category specificity verification, and optimal core substance screening verification, screening step by step until the final core characteristic flavor substances are locked.

[0035] The interference removal verification includes: verifying whether each candidate flavor substance belongs to the category of the general flavor substance library for meat. If the candidate substance matches the general alkanes or conventional aldehydes as basic flavor substances, it is directly identified as an interference substance and removed. Only terpenes, unsaturated alcohols, and characteristic esters belonging to the Pingliang Red Bull exclusive flavor substance library are retained.

[0036] If the number of candidate substances verified through interference elimination is still more than one, then the stability verification of Pingliang Red Bull samples will be performed. The stability verification of Pingliang Red Bull samples includes: calculating the detection rate of each candidate substance in multiple batches of standardized Pingliang Red Bull samples aged 18-24 months, and verifying whether the sample detection rate of each candidate substance is not less than 95%; eliminating candidate substances with a detection rate of less than 95%, sporadic detection, or poor stability.

[0037] If the number of candidate substances that pass the stability verification of Pingliang Red Cattle samples is still more than one, cross-category specificity verification will be performed. Cross-category specificity verification includes: calculating the detection rate of each candidate substance in control livestock and poultry meat samples such as ordinary yellow cattle, pork, chicken, and mutton, and verifying whether the cross-category detection rate of each candidate substance is less than 5%; and removing candidate substances that are frequently detected across categories and have no breed-specific characteristics.

[0038] If the number of candidate substances that pass the cross-category specificity verification is still more than one, then the optimal core substance screening verification is performed. The optimal core substance screening verification includes: calculating the flavor contribution of the remaining candidate substances, identifying the substance with the highest flavor contribution and that plays a key role in the formation of the characteristic flavor of Pingliang Red Bull as the final core characteristic flavor substance, and summarizing them to form a standardized core characteristic flavor substance list.

[0039] To clearly illustrate the multi-level verification and screening process of this invention, two sets of specific comparative examples are provided, corresponding to different screening scenarios:

[0040] Example 1: In this embodiment, a single detection initially screened 12 candidate flavor substances. Interference elimination verification removed 7 common alkanes and conventional aldehydes, leaving 5 specific candidate substances. Pingliang Red Bull sample stability verification removed 2 unstable substances with detection rates of only 82% and 88%, leaving 3 candidate substances. Cross-category specificity verification removed 1 non-specific substance with a cross-category detection rate of 12%, leaving 2 specific candidate substances. In the fourth level of flavor contribution screening, the 2 substances with higher flavor contribution were finally determined as core characteristic flavor substances, completing the screening.

[0041] Example 2: Initial screening of batch testing yielded 15 candidate flavor substances. Interference elimination verification removed 9 common flavor interference substances, leaving 6 exclusive candidate substances. After stability verification of Pingliang Red Bull samples, the detection rate of all 6 substances was ≥95%, and all passed. After cross-category specificity verification, the cross-category detection rate of all 6 substances was <5%, and all passed. In the fourth level, based on the flavor contribution, 9 core flavor substances were selected to form the core characteristic flavor substance list of Pingliang Red Bull.

[0042] In a preferred embodiment, the specific criteria for S5 quantitative identification and quality grading are as follows: the preset core characteristic flavor substance detection standard includes the minimum effective content threshold, the optimal content range, and the multi-component synergistic standard ratio; gas chromatography-mass spectrometry is used to accurately detect the actual content and component ratio of each core substance, and the measured data are compared with the preset standard one by one to classify the quality into three levels: high quality, qualified, and unqualified.

[0043] Excellent grade judgment: The actual content of all core characteristic flavor substances falls within the optimal content range, and the deviation of multiple group distribution ratios is ≤3%, indicating the best flavor synergy effect; Qualified grade judgment: The actual content of all core characteristic flavor substances is higher than the minimum effective content threshold, but not all reach the optimal range, and the distribution ratio deviation is ≤8%, indicating that the flavor quality meets the standard; Unqualified grade judgment: The content of any core characteristic flavor substance is lower than the minimum effective content threshold, or the distribution ratio deviation is >8%, indicating that the flavor quality does not meet the standard, there are flavor defects, or it is a counterfeit sample.

[0044] To verify the superiority of the present invention over the prior art, a control experiment was set up, using the same Pingliang Red Bull sample, and the existing patented methods and the method of the present invention were tested and compared respectively.

[0045] Control group 1: Using a general meat flavor detection scheme based on existing technology, without a dedicated database for screening, multi-level specificity verification, or quantitative grading standards, samples of the same batch of Pingliang Red Beef were tested. The results showed that the method detected a total of 33 flavor substances, including 22 common meat interfering substances. It could not distinguish between general flavors and Pingliang Red Beef-specific flavors, exhibiting extremely poor screening specificity. It could only qualitatively determine the presence or absence of flavor substances, but could not identify specific characteristic substances or determine the quality of flavors. It was completely unsuitable for the identification and quality grading requirements of Pingliang Red Beef-specific flavors.

[0046] Control group 2: The entire screening, verification, quantitative grading process of this invention was fully implemented, all 22 common interfering substances were accurately eliminated, and 9 core characteristic flavor substances exclusive to Pingliang Red Bull were screened out through multi-level verification. The quantitative detection of the content of each substance and the component ratio analysis were accurately completed, and the sample was finally determined to be of high quality flavor grade.

[0047] Multiple batch repeatability tests show that the method of this invention is standardized throughout the process, with controllable parameters. The consistency error of test results among different batches and operators is less than 5%, and the screening specificity, detection accuracy, and grading accuracy are far superior to existing patented technologies. This invention solves the shortcomings of existing technologies in terms of poor screening specificity by eliminating interference from the Pingliang Red Bull exclusive flavor screening database and verifying multi-level specificity. It also solves the shortcomings of existing technologies in terms of quality quantification and grading by establishing a quantitative threshold and ratio grading system. The test results are accurate, stable, and quantifiable, suitable for precise laboratory scientific research testing, and can also meet the batch testing needs of meat product industrial quality control, market authenticity identification, and variety resource protection.

[0048] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for screening and identifying characteristic flavor compounds of Pingliang Red Bull, characterized in that, Includes the following steps: S1: Collect standardized Pingliang Red Beef muscle samples, perform aseptic pretreatment on the Pingliang Red Beef muscle samples to remove surface fat, fascia and blood clots, and obtain pure muscle test samples. S2: Extract flavor substances from the pure muscle test sample to enrich all volatile flavor substances in the sample and obtain the flavor extract stock solution. S3: Construct a Pingliang Red Cattle exclusive flavor screening database, and eliminate common meat flavor interfering substances by comparing and eliminating the Pingliang Red Cattle exclusive flavor screening database to initially screen out candidate characteristic flavor substances of Pingliang Red Cattle. S4: Conduct specific verification and screening of candidate characteristic flavor substances, eliminate occasional flavor substances that are not exclusive to Pingliang Red Bull, and determine the list of core characteristic flavor substances of Pingliang Red Bull. S5: Based on the preset threshold and ratio standards for the content of characteristic flavor substances of Pingliang Red Bull, quantitative identification and flavor quality grading of core characteristic flavor substances are carried out to complete the screening and identification of characteristic flavor substances of Pingliang Red Bull.

2. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The aseptic pretreatment specifically includes: rinsing the original sample surface with sterile physiological saline to remove residual impurities, rinsing 2-3 times; after rinsing, using sterile filter paper to absorb the moisture from the sample surface; removing the white fat layer, dense fascia, and dark congested tissue from the sample surface in a sterile ultra-clean workbench, retaining only the fresh red muscle body tissue; chopping the muscle into particles with a diameter of 3-5 mm to obtain a pure muscle test sample; the pretreatment temperature is controlled at 0-4℃ throughout the process, and the pretreatment time does not exceed 15 minutes.

3. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The flavor substance extraction process employs headspace solid-phase microextraction (HS-SPME). The specific operation includes: weighing 5-8g of pure muscle test sample and placing it in a headspace extraction bottle, sealing the extraction bottle, and placing it in a constant temperature water bath environment for equilibration for 15-20 minutes. Then, inserting the solid-phase microextraction head and performing headspace adsorption extraction for 30-40 minutes, with the extraction temperature stabilized at 55-60℃. After extraction, removing the extraction head and thermally desorbing the sample to obtain the flavor extract stock solution, which contains all volatile and semi-volatile flavor substances in the sample.

4. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The Pingliang Red Cattle exclusive flavor screening database is constructed as follows: Flavor testing data from multiple batches of standardized Pingliang Red Cattle, ordinary yellow cattle, hybrid beef cattle, and other types of livestock and poultry meat are collected. Common flavor substances shared by various types of meat and flavor substances unique to Pingliang Red Cattle are summarized and categorized to form the Pingliang Red Cattle exclusive flavor screening database, which includes a database of common flavor substances and a database of Pingliang Red Cattle exclusive flavor substances. The database of common flavor substances includes basic flavor substances such as alkanes and conventional aldehydes commonly found in various types of meat, while the database of Pingliang Red Cattle exclusive flavor substances includes terpenes, unsaturated alcohols, and characteristic esters unique to Pingliang Red Cattle.

5. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The process of eliminating common flavor interference substances in meat through database comparison involves importing the substance detection data of the flavor extract into a dedicated flavor screening database, comparing each detected flavor substance component with the database, marking components that match the common flavor substance library as interference substances and eliminating them directly, and retaining components that only match the Pingliang Red Bull's dedicated flavor substance library as candidate characteristic flavor substances for Pingliang Red Bull, thus completing the initial screening.

6. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The specificity verification screening specifically includes: selecting standardized Pingliang Red Cattle samples from different breeding cycles and different breeding batches for repeated testing, while selecting ordinary beef cattle and other livestock and poultry meat samples for control testing, and statistically analyzing the detection rate and specificity of each candidate characteristic flavor substance.

7. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The criteria for the specificity verification screening are as follows: candidate substances with a detection rate of not less than 95% in multiple batches of Pingliang Red Cattle samples and a detection rate of less than 5% in ordinary beef cattle and other livestock and poultry meat samples are identified as the core characteristic flavor substances of Pingliang Red Cattle. Candidate substances with a detection rate of less than 90% in Pingliang Red Beef samples or those frequently detected in other meats were identified as occasional interfering substances and removed. Finally, a list of core characteristic flavor substances of Pingliang Red Beef was compiled.

8. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The preset threshold and ratio standards for the characteristic flavor substances of Pingliang Red Bull were obtained by statistical fitting of flavor test data from multiple batches of high-quality Pingliang Red Bull. Specifically, they include the minimum effective content threshold, optimal content range, and synergistic ratio of each core characteristic flavor substance.

9. The method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The quantitative identification specifically involves: using gas chromatography-mass spectrometry to quantitatively detect the core characteristic flavor substances, obtaining the actual content and component ratio data of each core characteristic flavor substance, and comparing the actual detection data with preset content thresholds and ratio standards one by one.

10. A method for screening and identifying characteristic flavor compounds of Pingliang Red Bull according to claim 1, characterized in that, The flavor quality grading specifically includes three levels: excellent, qualified, and unqualified. When the actual content of all core characteristic flavor substances is within the optimal content range and the composition ratio meets the standard ratio, the sample is judged to be of excellent Pingliang Red Bull flavor grade. When the actual content of all core characteristic flavor substances is higher than the minimum effective content threshold, but not all reach the optimal range, and the composition ratio deviation is within the allowable range, the sample is judged to be of qualified Pingliang Red Bull flavor grade. When the actual content of any core characteristic flavor substance is lower than the minimum effective content threshold, or the composition ratio deviation exceeds the allowable range, the sample is judged to be of unqualified Pingliang Red Bull flavor grade.

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