Quality control method for characteristic flavor in Maotai wine brewing process

Abstract

The invention discloses a quality control method for characteristic flavor in a Maotai wine brewing process, and belongs to the field of analysis and detection. The quality control method for the characteristic flavor in the Maotai wine brewing process comprises the steps of characteristic flavor component detection and characteristic flavor data analysis, detection component detection and quantification are carried out by using high-sensitivity PTR-TOF-MS, and data analysis is carried out by combining Pirouette software. And determining the characteristic flavor substance components of the Maotai wine in each fermentation process through Wehn analysis. The method has the advantages of rapidness, high efficiency, multiple types of detected aromas and accurate quantification, can be applied to quality control in the Maotai wine brewing process, and has important guidance value for Maotai wine production.

Description

Technical Field

[0001] The present invention relates to the field of analysis and detection, and more specifically, to a method for controlling the quality of characteristic flavors in a sauce-flavored liquor brewing process. Background Art

[0002] Maotai-flavor liquor (Maotai-flavor liquor) is one of the five major flavor types of Chinese liquor. Maotai-flavor liquor represented by Guizhou Moutai, Lai Mao, Fujian Shuanglong Xizhu Liquor, etc. belongs to the Daqu liquor category. Its style characteristics are prominent Maotai aroma, elegant and delicate, mellow body, and long-lasting fragrance, and it is deeply loved by people.

[0003] The brewing process of Maotai-flavor liquor is unique and influenced by numerous factors, making the fermentation process extremely complex and crucial. Maotai-flavor liquor undergoes up to eight fermentation cycles, each with its own specific process and purpose. Taking Shuanglong Xizhu liquor as an example, the quality and style of the liquor produced in each of the seven extraction cycles differed. The quality of the liquor produced from mash collected from different locations in the cellar during the same cycle can also vary significantly. This is primarily due to the influence of temperature, humidity, and microorganisms on the transformation of the characteristic flavor during the fermentation process. Furthermore, due to the wide variety of aromas in Maotai-flavor liquor, many factors influence its quality. Existing liquor ratings rely primarily on manual evaluation, which is not only time-consuming and labor-intensive, but can also be influenced by subjective factors. Therefore, aroma detection and objective quality control during the brewing process are particularly important.

[0004] CN117805290A discloses a gas chromatography method for detecting the aroma components of liquor. By quantifying each aroma component, corresponding fingerprint detection methods and quality control standards are established. However, due to the complexity of aroma components, some aromas are unavailable as standard. Furthermore, some aromas have poor high-temperature stability or low concentrations, making them difficult to detect or calibrate in gas chromatography.

[0005] CN116773704A discloses a method for analyzing aroma components in empty liquor cups, using HS-SPME combined with GC-MS to analyze aroma components in empty liquor cups. GC-MS has high sensitivity and can detect even low levels of aroma, but it cannot address the high-temperature stability of some aromas. Due to the high bombardment energy of GC-MS, aroma fragmentation is complex, complicating the mass spectrum and potentially preventing the detection results of some aroma components from being matched against the database. Furthermore, due to the complexity of aroma components, standards for some aromas are unavailable, making it difficult to quantify aroma during the winemaking process. Summary of the Invention

[0006] To address these issues, the present invention discloses a method for quality control of characteristic flavors during the fermentation of sauce-flavored liquor. The method is rapid and efficient, detects a wide range of aromas, and accurately quantifies them. It can be applied to quality control during the fermentation of sauce-flavored liquor and provides valuable guidance for its production.

[0007] The method for quality control of characteristic flavor in the brewing process of sauce-flavored liquor described in the present invention includes characteristic flavor component detection and characteristic flavor data analysis; the method for detecting characteristic flavor components adopts PTR-TOF-MS, and selects an internal standard composition to perform auxiliary quantification on the mash, thereby obtaining the component data of the characteristic flavor in the mash; the characteristic flavor data analysis is to perform statistical analysis on the component data of the characteristic flavor in the mash, thereby analyzing the characteristic flavor of sauce-flavored liquor in different fermentation processes.

[0008] Furthermore, the method for detecting the components of the characteristic flavor specifically comprises the following steps:

[0009] Step 1, homogenizing the fermented grains: accurately weigh 10 g of the mixed fermented grains and add them to a 100 mL polytetrafluoroethylene centrifuge tube, add 40 mL of 5 wt% ethanol water and 40 g of salt, mix well, homogenize at a speed of 18000 rpm for 15 seconds, shake in an oscillator for 30 minutes, centrifuge at 4000 rpm for 15 minutes, and transfer the suspension to a 100 mL conical flask; continue to add 20 mL of 5 wt% ethanol water to the polytetrafluoroethylene centrifuge tube to wash the polytetrafluoroethylene centrifuge tube, homogenize at a speed of 18000 rpm for 15 seconds, shake in an oscillator for 30 minutes, centrifuge at 4000 rpm for 15 minutes, and transfer the supernatant to a 100 mL conical flask; repeat washing once, combine the supernatants, accurately add 0.1 g of the internal standard composition to the 100 mL conical flask, supplement 5 wt% ethanol water to 100 g, mix well, and obtain a fermented grains dilution;

[0010] Step 2: Accurately weigh 10 g of the fermented grains dilution into a 60 mL clean, dry headspace bottle, seal it, and set a constant temperature for a period of time to allow the volatile substances above the liquid surface of the headspace bottle to reach equilibrium;

[0011] Step 3: Connect the headspace bottle containing the fermented grains dilution to the inlet of the PTR-TOF-MS to allow the volatile substances to drift into the PTR-TOF-MS for detection. Scan each sample 5 times continuously, and take the average value of the mass spectrum data as the test value.

[0012] Step 4: Connect the empty headspace vial to the inlet of the PTR-TOF-MS, set the parameters consistent with step 3, scan the air 5 times, and take the average value of the mass spectrum data as the blank value. Subtract the blank value from the sample test value to obtain the average value of the sample mass spectrum data. Use the ratio of the internal standard response value and the content of the internal standard in the sample mass spectrum data as the quantitative basis to calculate the content of the characteristic flavor in the fermented grains.

[0013] Preferably, the fermented grains are fermented grains from the second, third, fourth, fifth, sixth, seventh or eighth fermentation in the process of brewing sauce-flavored liquor; about 200 g of each fermented grain is placed in the same fermentation tank, mixed evenly and then sealed for storage;

[0014] Preferably, the salt is sodium chloride;

[0015] Preferably, the internal standard composition is tert-butyl alcohol-d1 (CAS No.: 3972-25-6, molecular formula (CH3)3COD), ethyl acetoacetate-1,3-C2 (CAS No.: 77504-74-6, molecular formula 13 CH3CO 13 CH2COOCH2CH3), d5-ethyl hexanoate (CAS No. 1082581-90-5, molecular formula C8H 11 D5O2), diethyl malonate-d2 (CAS No. 4303-49-5, molecular formula C7H 10 D2O4), benzaldehyde-α-d1 (CAS No.: 3592-47-0, molecular formula C6H5CDO); the internal standard composition is calculated by weight, accounting for 96wt% of tert-butyl alcohol-d1, and the remaining internal standards each account for 1wt%, and the internal standard composition is obtained after uniform mixing;

[0016] Preferably, the constant temperature is 50°C;

[0017] Preferably, the volatiles equilibration time is 30 minutes;

[0018] Preferably, the instrument conditions of the PTR-TOF-MS are set as follows: drift tube voltage 500-600V, drift tube temperature 60-70°C, drift tube pressure 125-250Pa; electric field strength 120-150Td; gas flow in the drift tube 10-30mL / min; injection time 30 seconds; mass scan range m / z = 10-700; each sample is measured for 30 seconds at an acquisition rate of one TIC spectrum per second, scanned continuously 5 times, and the average value is taken.

[0019] Preferably, the method for analyzing characteristic flavor data is as follows:

[0020] The Pirouette statistical analysis software was used to perform statistical analysis on the component data of the sauce-flavored liquor detected by PTR-TOF, and to determine the components and concentration of the sauce-flavored liquor during each fermentation process. The Pirouette statistical analysis used the principal component analysis module (PCA) to perform statistics on the component data of the sauce-flavored liquor detected by PTR-TOF, and determined the characteristic flavor substance components of the sauce-flavored liquor during each fermentation process through Wayne analysis. The quantitative results were combined to evaluate the fermentation degree of the liquor.

[0021] The beneficial effects of the present invention are as follows: the present invention uses a highly sensitive PTR-TOF-MS, which can perform qualitative analysis without calibration, selects a mixed internal standard to be added to the system for auxiliary quantitative analysis, measures a large number of characteristic flavor substances, and combines the PCA module of the Pirouette statistical analysis software to perform statistical analysis on the component data of the characteristic flavor in the sauce-flavored liquor detected by PTR-TOF; and based on the analysis result of the PCA module, determines whether the content of the characteristic flavor substances in the tested mash reaches the expected standard through Wayne analysis, which is beneficial to the quality control of the brewing process of different batches of sauce-flavored liquor, and is beneficial to reducing the influence of subjective factors on the quality of sauce-flavored liquor during the brewing process, and has important guiding value for improving the quality of sauce-flavored liquor.

[0022] 1. The PTR-TOF-MS described in the present invention uses a soft ionization technology to make the positively charged protons of volatile organic compounds almost all molecular ion peaks in the time-of-flight mass spectrum. The molecular structure can be inferred through automatic comparison and analysis of the mass-to-charge ratio without the need for calibration and with high accuracy. The PTR-TOF-MS of the present invention has high sensitivity and can detect trace volatile substances. It can detect the aroma components in sauce-flavored liquor and explore the synergistic effects of various aroma components.

[0023] 2. While the PTR-TOF-MS method described in the present invention is highly sensitive and provides accurate qualitative analysis, it is difficult to accurately quantify trace substances. Based on the varying volatility of various characteristic flavor compounds in sauce-flavored liquor, the present invention selects an internal standard composition, calibrates the ionization efficiency, and achieves accurate quantitative analysis, facilitating subsequent data analysis.

[0024] 3. The present invention adds salt to the mash to enhance water penetration, allowing for faster and more complete extraction of volatile substances from the mash. Simultaneously, the mash extract dissolves salt, reducing the water vapor partial pressure, resulting in a lower water vapor ratio in the headspace vial, which helps increase the proportion of volatile substances in the mash and improves detection sensitivity. Furthermore, the addition of an appropriate amount of salt acts as a grinding agent during the homogenization process, grinding the mash finer and more evenly for easier extraction.

[0025] 4. The present invention uses Pirouette statistical analysis software to perform statistical analysis on the component data of sauce-flavored liquor detected by PTR-TOF, and determines the components and concentration of sauce-flavored liquor during each fermentation process. The Pirouette statistical analysis uses the principal component analysis module (PCA) to perform statistics on the component data of sauce-flavored liquor detected by PTR-TOF, and determines the characteristic flavor components of sauce-flavored liquor during each fermentation process through Wayne analysis. The quantitative results are combined to evaluate the fermentation degree of the fermented liquor. This is beneficial for quality control of different batches of sauce-flavored liquor brewing processes, and is beneficial for reducing the impact of subjective factors on the quality of sauce-flavored liquor during the brewing process, and has important guiding value for improving the quality of sauce-flavored liquor.

[0026] Figures in the specification

[0027] Figure 1 VIP diagram of characteristic flavor components and contents of the mash in Examples 1-7.

[0028] Figure 2 This is a PCA scatter plot of the characteristic flavor component data of the mash in Examples 1-7.

[0029] Figure 3 This is a Wayne analysis diagram of the characteristic flavor components of the fermented grains obtained in Examples 1-7. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0032] Example 1

[0033] A method for detecting the components of characteristic flavors during the brewing process of sauce-flavored liquor is described as follows:

[0034] Step 1: Homogenize the mash: Accurately weigh 10 g of mash after the second fermentation in the sauce wine brewing process and add it to a 100 mL polytetrafluoroethylene centrifuge tube, add 40 mL of 5 wt% ethanol water and 40 g of sodium chloride, mix well, homogenize at a speed of 18000 rpm for 15 seconds, shake for 30 minutes, centrifuge at 4000 rpm for 15 minutes, and transfer the suspension to a 100 mL conical flask; continue to add 20 mL of Wash a polytetrafluoroethylene centrifuge tube with 5wt% ethanol water, homogenize at a speed of 18000 rpm for 15 seconds, shake in an oscillator for 30 minutes, centrifuge at 4000 rpm for 15 minutes, and transfer the supernatant to a 100mL conical flask; repeat the washing once, combine the supernatants, accurately add 0.1g of an internal standard composition to the 100mL conical flask, add 5wt% ethanol water to 100g, mix well, and obtain a wine mash dilution; the internal standard composition is a composition of 96wt% tert-butanol-d1, 1wt% ethyl acetoacetate-1,3-C2, 1wt% hexanoic acid-d5-ethyl ester, 1wt% diethyl malonate-d2, and 1wt% benzaldehyde-α-d1;

[0035] Step 2: Accurately weigh 10 g of the fermented grains dilution into a 60 mL clean and dry headspace bottle, seal it, and set it to a constant temperature of 50°C for 30 minutes to allow the volatile substances above the liquid surface of the headspace bottle to reach equilibrium;

[0036] Step 3. Connect the headspace bottle to the injection port of the PTR-TOF-MS so that its volatile substances drift into the PTR-TOF-MS for detection. Each sample is scanned continuously for 5 times, and the average value of the mass spectrum data is taken as the test value. The instrument conditions of the PTR-TOF-MS are set as follows: drift tube voltage 500-600V, drift tube temperature 60-70°C, drift tube pressure 125-250Pa; electric field strength 120-150Td; gas flow rate in the drift tube 10-30mL / min; injection time 30 seconds; mass scanning range m / z = 10-700; each sample is measured for 30 seconds at an acquisition rate of one TIC spectrum per second, scanned 5 times continuously, and the average value is taken.

[0037] Step 4: Connect the empty headspace vial to the inlet of the PTR-TOF-MS, set the parameters consistent with step 3, scan the air 5 times, and take the average value of the mass spectrum data as the blank value. Subtract the blank value from the sample test value to obtain the average value of the sample mass spectrum data. Use the ratio of the internal standard response value and the content of the internal standard in the sample mass spectrum data as the quantitative basis to calculate the content of the characteristic flavor in the fermented grains.

[0038] Example 2

[0039] The steps and methods of Example 2 are the same as those of Example 1, except that the mash fermented for the second time in the sauce-flavored liquor brewing process in Example 1 is replaced by the mash fermented for the third time in the sauce-flavored liquor brewing process.

[0040] Example 3

[0041] The steps and methods of Example 3 are the same as those of Example 1, except that the mash fermented for the second time in the sauce-flavored liquor brewing process in Example 1 is replaced by the mash fermented for the fourth time in the sauce-flavored liquor brewing process.

[0042] Example 4

[0043] The steps and methods of Example 4 are the same as those of Example 1, except that the mash fermented for the second time in the sauce-flavored liquor brewing process in Example 1 is replaced by the mash fermented for the fifth time in the sauce-flavored liquor brewing process.

[0044] Example 5

[0045] The steps and methods of Example 5 are the same as those of Example 1, except that the mash fermented for the second time in the sauce-flavored liquor brewing process in Example 1 is replaced by the mash fermented for the sixth time in the sauce-flavored liquor brewing process.

[0046] Example 6

[0047] The steps and methods of Example 6 are the same as those of Example 1, except that the mash fermented for the second time in the sauce-flavored liquor brewing process in Example 1 is replaced by the mash fermented for the seventh time in the sauce-flavored liquor brewing process.

[0048] Example 7

[0049] The steps and methods of Example 7 are the same as those of Example 1, except that the mash fermented for the second time in the sauce-flavored liquor brewing process in Example 1 is replaced by the mash fermented for the eighth time in the sauce-flavored liquor brewing process.

[0050] Example 8

[0051] The data of characteristic flavor components of the fermented mash obtained in Examples 1-7 were statistically analyzed using Pirouette statistical analysis software. The PCA module was selected to perform statistical analysis on the components of the characteristic flavor of the sauce-flavored liquor during each fermentation process. The substances with VIP values greater than 1 were taken as the main characteristic flavor components in the fermented mash, which contained about 93 substances that contributed to the sauce-flavored liquor from different production areas. The types and contents of the characteristic flavor components of the fermented mash were shown in the VIP diagram. Figure 1 As shown. Figure 1 It can be clearly seen that the characteristic flavor components of the mash fermented in each time are quite different.

[0052] Figure 2 The PCA scatter plots of the characteristic flavor component data of the fermented mash after each fermentation in Examples 1-7 are shown. It can be clearly seen that the characteristic flavor components of the fermented mash after each fermentation are quite different. The mash from the second, third, and eighth fermentations are clearly distinguished from the mash from other rounds. The mash from the fourth, fifth, sixth, and seventh fermentations has a higher degree of aggregation, indicating that the mash from these rounds is highly similar. However, it can still be seen that the content is relatively concentrated. There are certain differences between the mash from each fermentation round, which is beneficial for product quality control.

[0053] Figure 3 This is a Wayne analysis diagram of the characteristic flavor components of the fermented grains obtained in Examples 1-7. Figure 3 It shows that the mash fermented in different rounds of Examples 1-7 has its own characteristic flavor, and the sauce-flavored liquor brewing process can be fine-tuned in a timely manner by the content and type of the characteristic flavor to achieve the purpose of controlling the stability of product quality.

[0054] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for controlling the quality of characteristic flavors during the brewing process of sauce-flavored liquor, characterized in that: The method includes characteristic flavor component detection and characteristic flavor data analysis; the characteristic flavor component detection method adopts PTR-TOF-MS, and selects an internal standard composition to assist in quantification of the mash, thereby obtaining the component data of the characteristic flavor in the mash; the characteristic flavor data analysis is to perform statistical analysis on the component data of the characteristic flavor in the mash, thereby analyzing the characteristic flavor of the sauce-flavored liquor in different fermentation processes.

2. The method for controlling the quality of characteristic flavors in the brewing process of sauce-flavored liquor according to claim 1, characterized in that: The method for detecting characteristic flavor components specifically comprises the following steps: Step 1, homogenizing the fermented grains: accurately weigh 10 g of the mixed fermented grains and add them to a 100 mL polytetrafluoroethylene centrifuge tube, add 40 mL of 5 wt% ethanol water and 40 g of salt, mix well, homogenize at a speed of 18000 rpm for 15 seconds, shake in an oscillator for 30 minutes, centrifuge at 4000 rpm for 15 minutes, and transfer the suspension to a 100 mL conical flask; continue to add 20 mL of 5 wt% ethanol water to the polytetrafluoroethylene centrifuge tube to wash the polytetrafluoroethylene centrifuge tube, homogenize at a speed of 18000 rpm for 15 seconds, shake in an oscillator for 30 minutes, centrifuge at 4000 rpm for 15 minutes, and transfer the supernatant to a 100 mL conical flask; Repeat washing once, combine the supernatants, accurately add 0.1 g of the internal standard composition to a 100 mL conical flask, add 5 wt% ethanol water to 100 g, mix well, and obtain a dilution of the fermented grains; Step 2: Accurately weigh 10 g of the fermented grains dilution into a 60 mL clean, dry headspace bottle, seal it, and set a constant temperature to allow the volatile substances above the liquid surface of the headspace bottle to reach equilibrium; Step 3: Connect the headspace bottle containing the fermented grains dilution to the inlet of the PTR-TOF-MS to allow the volatile substances to drift into the PTR-TOF-MS for detection. Scan each sample 5 times continuously, and take the average value of the mass spectrum data as the test value. Step 4: Connect the empty headspace bottle to the injection port of the PTR-TOF-MS, set the parameters consistent with step 3, scan the air 5 times, and take the average value of the mass spectrum data as the blank value; subtract the blank value from the sample test value to obtain the average value of the sample mass spectrum data; use the internal standard response value in the sample mass spectrum data and the ratio of the internal standard content as the quantitative basis to calculate the content of the characteristic flavor in the mash.

3. The method for controlling the quality of characteristic flavors in the brewing process of sauce-flavored liquor according to claim 1, characterized in that: The method for analyzing the characteristic flavor data is described as follows: Pirouette statistical analysis software is used to perform statistical analysis on the component data in the sauce-flavored liquor mash detected by PTR-TOF, and the components and concentration of the sauce-flavored liquor during each fermentation process are determined; the Pirouette statistical analysis uses the principal component analysis module PCA to perform statistics on the component data in the sauce-flavored liquor mash detected by PTR-TOF, and the characteristic flavor substance components of the sauce-flavored liquor during each fermentation process are determined by Wayne analysis; the quantitative results are combined to evaluate the fermentation degree of the mash.

4. The method for controlling the quality of characteristic flavor in the fermentation process of sauce-flavored liquor according to claim 1 or 2, characterized in that: The fermented grains are fermented grains after the second, third, fourth, fifth, sixth, seventh or eighth fermentation in the process of brewing sauce-flavored liquor.

5. The method for controlling the quality of characteristic flavors in the fermentation process of sauce-flavored liquor according to claim 2, characterized in that: The salt in step 1 is sodium chloride.

6. The method for controlling the quality of characteristic flavors in the fermentation process of sauce-flavored liquor according to claim 1 or 2, characterized in that: The internal standard composition is a composition of tert-butanol-d1, ethyl acetoacetate-1,3-C2, ethyl hexanoate-d5, diethyl malonate-d2 and benzaldehyde-α-d1; the internal standard composition is calculated by weight, tert-butanol-d1 accounts for 96wt%, the remaining internal standards each account for 1wt%, and all the internal standard substances are uniformly mixed to obtain the internal standard composition.

7. The method for controlling the quality of characteristic flavors in the fermentation process of sauce-flavored liquor according to claim 2, characterized in that: The constant temperature in step 2 is 50°C.

8. The method for controlling the quality of characteristic flavors in the fermentation process of sauce-flavored liquor according to claim 2, characterized in that: The equilibration time in step 2 is 30 minutes.

9. The method for controlling the quality of characteristic flavors in the fermentation process of sauce-flavored liquor according to claim 1 or 2, characterized in that: The instrument conditions of the PTR-TOF-MS were set as follows: drift tube voltage 500-600 V, drift tube temperature 60-70° C., drift tube pressure 125-250 Pa; electric field strength 120-150 Td; gas flow rate in the drift tube 10-30 mL / min; injection time 30 seconds; mass scan range m / z = 10-700; each sample was measured for 30 seconds at an acquisition rate of one TIC spectrum per second, scanned continuously five times, and the average value was taken.

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