阅读说明：本技术 一种酱香型白酒中咸味的检测方法 (Method for detecting salty taste in Maotai-flavor liquor ) 是由 杨婧 胡光源 陈双 林琳 王和玉 王莉 徐岩 于 2020-05-19 设计创作，主要内容包括：本申请公开了一种酒中咸味的检测方法,包括检测所述酒中含呋喃环的硫化合物,并根据所述酒中的所述含呋喃环的硫化合物的含量,推定所述酒中是否具有咸味,或其具有的咸味的程度。本申请公开了含呋喃环的硫化合物的检测方法在酒中咸味的检测方法上的应用,还公开了一种构建鉴别酒中咸味的判别模型的方法,包括根据酒的咸味强度数据及含呋喃环的硫化合物的定量分析结果构建判别模型。本申请的检测方法有利于对企业酿造过程异味形成的控制提供靶向指导,且为酱香型白酒产品质量的评价提供客观科学的方法。(The application discloses a method for detecting salty taste in wine, which comprises the steps of detecting furan ring-containing sulfur compounds in the wine, and estimating whether the wine has salty taste or the degree of the salty taste according to the content of the furan ring-containing sulfur compounds in the wine. The application discloses an application of a detection method of sulfur compounds containing furan rings in a detection method of salty taste in wine, and also discloses a method for constructing a discrimination model for discriminating the salty taste in wine, which comprises the step of constructing the discrimination model according to the salty taste intensity data of the wine and the quantitative analysis result of the sulfur compounds containing furan rings. The detection method is beneficial to providing targeted guidance for controlling the formation of the peculiar smell in the brewing process of enterprises, and provides an objective and scientific method for evaluating the quality of the Maotai-flavor liquor product.)

1. A method for detecting the salty taste in wine is characterized by comprising the following steps:

detecting the sulfur compounds containing furan rings in the wine; and

and (c) estimating whether the wine has a salty taste or a salty taste degree based on the content of the furan ring-containing sulfur compound in the wine.

2. The application of the detection method of the sulfur compound containing furan ring in the detection method of salty taste in wine.

3. A method for constructing a discrimination model for discriminating salty taste in wine is characterized by comprising the following steps:

collecting saltiness intensity data of the wine;

carrying out quantitative analysis on the furan ring-containing sulfur compounds in the wine; and

constructing the discrimination model based on the salty taste intensity data of the wine and the quantitative analysis result;

preferably, the constructing the discriminant model is to construct the discriminant model by using a partial least squares discriminant analysis.

4. The method according to claim 1 or 3 or the use according to claim 2, wherein the wine is Maotai-flavor liquor.

5. The method of claim 1 or 3 or the use of claim 2, wherein the furan ring-containing sulfur compound comprises:

a 2-methylfuran group; and

mercapto or disulfide bonds.

6. The method or use of claim 5, wherein the thiol or disulfide linkage is:

carbon at position 3 of said 2-methylfuran group, or

The methyl group of the 2-methylfuran group.

7. The method according to claim 1 or 3 or the use according to claim 2,

the sulfur compound containing furan rings is selected from at least one, two, three or four of 2-methyl-3-furanthiol, furfurylthiol, methyl-2-methyl-3-furanyldisulfide and bis (2-methyl-3-furanyl) disulfide.

8. The method of claim 1 or 3 or the use of claim 2, wherein said detecting the content of furan ring-containing sulphur compounds in said wine comprises detecting by gas chromatography-mass spectrometry/aroma-smelling; and/or

Detecting by using a gas chromatography-pulse type flame photometric detector;

preferably, in the detection of the gas chromatography-pulsed flame photometric detector, the flow rate of the carrier gas is 1mL per minute, the temperature of the sample inlet and the detector is 230 ℃, the sulfur gate time at the detector end is 6 to 24.9 milliseconds, and the pulse frequency is 3 pulses per second.

9. The method or use according to claim 8 wherein said detecting the amount of furan ring-containing sulphur compounds in said wine comprises adding diisopropyldisulphide as an internal standard.

10. The method of claim 1, wherein the step of removing the metal oxide layer is performed in a batch process

The sulfur compound containing furan rings comprises 2-methyl-3-furanthiol, and the content of the sulfur compound is more than or equal to 5 mu g/L;

the furan ring-containing sulfur compound comprises furfuryl mercaptan, and the content of the furfuryl mercaptan is greater than or equal to 25 mu g/L;

the furan ring-containing sulfur compound comprises methyl-2-methyl-3-furyl disulfide, and the content of the disulfide is more than or equal to 8 mu g/L; and/or

The furan ring-containing sulfur compound comprises bis (2-methyl-3-furyl) disulfide, and the content of which is greater than or equal to 10 mu g/L, the wine is presumed to have a salty taste.

Technical Field

The application relates to the field of liquor taste detection, in particular to a method for detecting the salty taste in Maotai-flavor liquor.

Background

Maotai-flavor liquor is a typical representative of high-quality liquor in China, and with the development of socioeconomic performance and the improvement of the consumption level of consumers, the social demand for high-quality Maotai-flavor liquor is increasingly remarkable. The flavor components of Maotai-flavor liquor are quite complex, and researches show that the Maotai-flavor liquor contains more than 1000 kinds of volatile compounds. Due to the complexity of the flavor, the material components in the Maotai-flavor liquor which characterize the quality are not completely resolved, and great difficulty is brought to the evaluation and promotion of the product quality. The quality grade of the Maotai-flavor liquor is evaluated mainly by artificial sensory evaluation, and a relatively objective instrument discrimination and analysis method is lacked. Therefore, the fish and dragon products on the market are mixed, the judgment of consumers is difficult, and the phenomenon that the fish and dragon products are good in order often occurs.

Due to the fact that the brewing process of the Maotai-flavor liquor is complex, the control difficulty of production process links is high, control of a plurality of key parameters mainly depends on manual judgment, and flavor defects easily occur due to improper operation, so that the product quality is affected. Wherein, the salty taste is a flavor defect commonly occurring in the Maotai-flavor liquor, and the style and the characteristic of the salty taste are similar to the flavor of pickled foods. The salty taste perception of the Maotai-flavor liquor comprises the salty taste characteristics of aroma smelling perception and the salty taste characteristics of drinking perception. The high-intensity salty taste in the Maotai-flavor liquor can reduce the flavor quality of the Maotai-flavor liquor, and poor consumption experience is generated. Therefore, the quick determination of the salty taste defect can be used as an effective method for determining the quality of the Maotai-flavor liquor, and the analysis of the salty taste defect flavor chemical substance is also of great significance for controlling the salty taste intensity in the Maotai-flavor liquor and regulating and controlling the quality of the Maotai-flavor liquor.

Disclosure of Invention

In order to overcome the defects of the prior art, the application provides the detection method for the characteristic intensity of the salty taste in the Maotai-flavor liquor, which is beneficial to providing targeted guidance for controlling the formation of the peculiar smell in the brewing process of an enterprise and provides an objective and scientific method for evaluating the product quality of the Maotai-flavor liquor.

In order to solve the technical problems and achieve the technical effects, the technical scheme adopted by the application is as follows:

a method for detecting the salty taste of wine, which comprises detecting the furan ring-containing sulfur compound in the wine and estimating whether the wine has a salty taste or the degree of the salty taste according to the content of the furan ring-containing sulfur compound in the wine.

Also provides an application of the detection method of the sulfur compound containing the furan ring in the detection method of the salty taste in the wine.

Also provides a method for constructing a discrimination model for discriminating the salty taste in the wine, which comprises the following steps: collecting the salty taste intensity data of the wine, carrying out quantitative analysis on the sulfur compounds containing furan rings in the wine, and carrying out partial least square discriminant analysis based on the salty taste intensity data and the quantitative analysis result to obtain the discriminant model.

In some embodiments, the wine is Maotai-flavor liquor.

In some embodiments, the furan ring-containing sulfur compound comprises a 2-methylfuran group, and a mercapto or disulfide bond. In some embodiments, the thiol or disulfide bond connects the carbon at position 3 of the 2-methylfuran group, or a methyl group. In some embodiments, the furan ring-containing sulfur compound is selected from at least one, two, three, or four of 2-methyl-3-furanthiol, furfurylthiol, methyl-2-methyl-3-furanyldisulfide, and bis (2-methyl-3-furanyl) disulfide.

In some embodiments, the detecting the content of the furan ring-containing sulfur compound in the wine comprises detecting by gas chromatography-mass spectrometry/aroma smelling method, and/or detecting by gas chromatography-pulsed flame photometric detector.

In some embodiments, said detecting the amount of furan ring-containing sulfur compounds in said wine comprises detecting by adding diisopropyldisulfide as an internal standard.

In some embodiments, salty taste is presumed to be present in the wine when the content of 2-methyl-3-furanthiol is greater than or equal to 5 μ g/L, and/or the content of furfuryl thiol is greater than or equal to 25 μ g/L, and/or the content of methyl-2-methyl-3-furanyl disulfide is greater than or equal to 8 μ g/L, and/or the content of bis (2-methyl-3-furanyl) disulfide is greater than or equal to 10 μ g/L.

Drawings

FIG. 1 is a graph of sensory analysis results for normal samples, high intensity salty taste samples, and spiked normal samples.

FIG. 2 is a plot of PLS-DA t scores for the 2-methyl-3-furanthiol, furfurylthiol, methyl-2-methyl-3-furanyldisulfide and bis (2-methyl-3-furanyl) disulfide content in 30 Maotai-flavor liquor samples.

Fig. 3 is a substitution verification chart of the PLS-DA model obtained by performing a substitution test experiment on the salty taste discrimination model of the present application.

Detailed Description

To further clarify the technical solutions and effects adopted by the present application to achieve the intended purpose, the following detailed description of specific embodiments, structures, features and effects according to the present application will be made with reference to the accompanying drawings and preferred embodiments as follows:

compound identification

In some embodiments of the present application, the following methods are used to identify compounds in Maotai-flavor liquor that exhibit salty taste characteristics:

(1) separation and extraction of compounds

Two Maotai-flavor liquor samples, namely a normal sample A and a high-strength salty sample B, are prepared.

The white spirit sample is diluted to 10% vol alcoholic strength by volume fraction. Taking a certain amount of diluted Chinese liquor sample, adding 2-4 g, such as 3g, of sodium chloride per 10mL of Chinese liquor, stirring while allowing the solution to reach the temperature of extraction condition, and performing compound extraction.

In some embodiments, 10mL of white spirit may be added to a 20mL brown headspace bottle followed by 3g of sodium chloride. In some embodiments, the interior of the headspace bottle may be coated with an inert material to prevent oxidation of the sample during heating. However, the amounts of the added white spirit and sodium chloride are not limited thereto, and those skilled in the art will appreciate that the reaction conditions of the present application can be adjusted, or scaled up or down as desired.

In some embodiments, the extraction conditions may be 30-50 minutes, for example 40 minutes, at a temperature of 30 ℃. That is, in some embodiments, the solution may be allowed to reach 30 ℃ while stirring, for example, it may be stirred in a 30 ℃ water bath and stabilized for 15 minutes. Stirring can be carried out, for example, by adding a stirring bar. In some embodiments, the extraction may employ a model 50/30 μm, 2cm (divinylbenzene (DVB)/carbon fiber (CAR)/Polydimethylsiloxane (PDMS)) extraction head.

(2) Sample analysis and detection

And (3) analyzing the extracted sample obtained in the step (1) by adopting a gas chromatography-mass spectrometry/aroma smelling method (GC-MS/O) to identify the salty compounds in the Maotai-flavor liquor. The white wine sample is subjected to Aroma Extraction Dilution Analysis (AEDA) by adjusting the split-flow ratio of a gas chromatography sample inlet.

In some embodiments, the gas chromatography is performed at an inlet temperature of 250 ℃ for 5 minutes by thermal desorption. Adjustment of the split ratio may be in order from ratios as small as large as 5:1, 10:1, 25:1, 75:1, 150:1, 300:1 and 600: 1. However, the present application is not limited thereto, and it should be understood that the injection port temperature, the thermal desorption time, and the split ratio used can be adjusted by those skilled in the art according to the needs. In some embodiments, the gas chromatography is agilent 6890N gas chromatography.

After each sample injection, the fragrance smelling person smells at the port of an Olfactory Detector (ODP), and records the characteristics and retention time of each fragrance in the fragrance smelling process. In some embodiments, the sniffer temperature is 250 ℃, but the application is not limited thereto, and it is contemplated that one skilled in the art can adjust the temperature as desired.

Generally, the greater the odor intensity of a compound, indicating a greater aroma contribution to a sample of white wine, the greater the corresponding dilution Factor (FD) of the aroma.

(3) Characterization of the compound

From the recorded retention time of each aroma, its Retention Index (RI) is calculated, by which preliminary compound characterization of the aroma substance is performed. And finally determining the compound through further standard product verification.

According to the identification method of this example, at least 52 important aroma compounds can be identified in the normal sample a and the high-intensity salty taste sample B. As shown in table 1, compounds corresponding to 2-methyl-3-furanthiol (represented by the following formula (I)), furfurylthiol (represented by the following formula (II)), methyl-2-methyl-3-furanyldisulfide (represented by the following formula (III)), bis (2-methyl-3-furanyl) disulfide (represented by the following formula (IV)), and the like have correlation with salty taste characteristics.

TABLE 1 Retention index of Compounds having relevance to salty taste characteristics versus dilution factor for fragrance

It can be seen that the above compounds all have furan rings and also have sulphur, in particular mercapto or disulfide bonds. The carbon at the 2-position of the furan ring may have a substituent, for example, a hydrocarbon group having 1, 2, 3, 4 or 5 carbon atoms, for example, an alkyl group having 1, 2, 3, 4 or 5 carbon atoms, for example, a methyl group or an ethyl group, and specifically, a methyl group. And the mercapto or disulfide bond in the compound may be on the substituent, for example the methyl group; or on the carbon in the 3-position. On the other side of the double bond, a hydrocarbon group having 1, 2, 3, 4 or 5 carbon atoms, for example an alkyl group having 1, 2, 3, 4 or 5 carbon atoms, for example a methyl or ethyl group, and specifically a methyl group; or another furan ring, the 2-position of which may likewise have a substituent, for example a hydrocarbon group having 1, 2, 3, 4 or 5 carbon atoms, for example an alkyl group having 1, 2, 3, 4 or 5 carbon atoms, for example a methyl or ethyl group, and in particular a methyl group.

Quantitative analysis of compounds

In some embodiments of the present application, the compounds of the maotai-flavor liquor that exhibit off-flavor of salted vegetables are quantitatively analyzed by the following method.

(1) Separation and extraction of compounds

The white spirit sample is diluted to 10% vol alcoholic strength by volume fraction. Taking a certain amount of diluted Chinese liquor sample, adding 2-4 g, such as 3g, sodium chloride per 10mL Chinese liquor and 2 × 10 per 10mL Chinese liquor^-10–3×10^-10g, is, for example, 2.8X 10^{- 10}g diisopropyl disulfide as an internal standard, stirred while the solution was brought to the temperature of the extraction conditions, and then compound extraction was performed.

In some examples, 10mL of white spirit may be added to a 20mL brown headspace bottle followed by 3g of sodium chloride and 10 μ L of diisopropyl disulfide at 28 μ g/L. In some embodiments, the interior of the sample headspace bottle may be coated with an inert material to prevent oxidation of the sample during heating. However, the amounts of added white spirit, sodium chloride and diisopropyl disulfide are not limited thereto, and those skilled in the art will appreciate that the reaction conditions of the present application can be adjusted or scaled up or down as desired.

In some embodiments, the extraction conditions may be 30-50 minutes, for example 40 minutes, at a temperature of 30 ℃. That is, in some embodiments, the solution may be allowed to reach 30 ℃ while stirring, for example, it may be stirred in a 30 ℃ water bath and stabilized for 15 minutes. Stirring can be carried out, for example, by adding a stirring bar. In some embodiments, an extraction head model of 50/30 μm, 2cm (divinylbenzene/carbon fiber/polydimethylsiloxane) may be used for extraction.

(2) Compound quantification using gas chromatography-pulsed flame photometric detector (GC-PFPD)

Gas chromatography is adopted to connect a flame photometric detector in series, and a sample is separated by a chromatographic column.

In some embodiments, an Agilent 7890A gas chromatograph in series with a flame photometric detector may be employed. In some embodiments, the column may be a DB-FFAP column, which may have a column length of 30m, a diameter of 0.32mm, and a film thickness of 1 μm. In some embodiments, the gas chromatography ramp conditions may be 45 ℃ for 2 minutes, followed by 6 ℃ per minute ramp to 230 ℃ and 10 minutes hold. In some embodiments, the carrier gas flow rate may be 1mL per minute, and the sample inlet and detector temperatures may both be 230 ℃. The sulfur gate time at the detector end may be 6 to 24.9 milliseconds and the pulse frequency may be 3 pulses per second.

(3) Establishment of quantitative Standard Curve

In some embodiments, the identified compound of interest is subjected to quantitative analysis. Specifically, in some embodiments, a higher concentration of the target compound is added to a higher concentration, for example, 53% vol alcohol in water, diluted to a gradient of standard solution, and finally extracted and analyzed by an instrument in the same manner as a white spirit sample.

And establishing a standard curve according to the concentration and peak area ratio of the target compound with each known concentration to the internal standard, and then calculating the content of the compound in the sample to be detected.

Compound sensory function confirmation

In some embodiments of the present application, sensory function confirmation of the salty taste characterizing compounds in Maotai-flavor liquor is performed by the following method.

(1) Confirmation of salty taste

As shown in Table 2, 2-methyl-3-furanthiol, furfurylthiol, methyl-2-methyl-3-furanyldisulfide and bis (2-methyl-3-furanyl) disulfide (designated "spiked A") were added to the A sample at a concentration (shown in Table 2). Sensory evaluation panel sensory analysis was performed on the "spiked a" samples as well as the B samples.

TABLE 2 "spiked A" samples with added compounds and their concentrations

The results are shown in fig. 1, where the difference between the "spiked a" sample and the B sample was not significant at P <0.05, while the difference between the two samples was significant at P <0.05, respectively, from the a sample. After the 4 compounds are added into the Maotai-flavor liquor showing the normal style, the salty taste characteristics can be simulated and enhanced.

(2) Salty taste feature discrimination result

According to sensory evaluation result analysis of addition experiments, the Maotai-flavor liquor can show a remarkable salty taste characteristic when the 2-methyl-3-furanthiol content is higher than 5 mu g/L, the furfuryl thiol content is higher than 25 mu g/L, the methyl-2-methyl-3-furyl-disulfide content is higher than 8 mu g/L, and/or the bis (2-methyl-3-furyl) disulfide content is higher than 10 mu g/L.

Establishing a salty taste discrimination model

In some embodiments of the present application, the following method is used to construct a rapid discrimination model of salty taste intensity in Maotai-flavor liquor.

(1) 30 Maotai-flavor liquor samples with different strength and salty taste characteristics are selected, and the salty taste strength of the liquor samples is graded by a sensory evaluation group. 30 samples are collected and classified into three grades of G1 (weak or no salty taste intensity, high-quality wine), G2 (medium salty taste intensity, medium-quality wine) and G3 (high salty taste intensity, low-quality wine) according to the scoring result.

(2) Four compounds of 2-methyl-3-furanthiol, furfurylthiol, methyl-2-methyl-3-furanyl disulfide and bis (2-methyl-3-furanyl) disulfide were quantitatively analyzed in 30 Maotai-flavor liquor samples.

Principal Component Analysis (PCA) was performed based on the salty taste intensity scoring results and the results of quantitative Analysis, in which the cumulative contribution rate of the corresponding characteristic values of the first two Component variables, Principal components PC1 and PC2, was 70.108%.

In this example, supervised Partial least squares discriminant analysis (PLS-DA) was performed on these samples by SIMCA-P software. The partial least squares discriminant analysis is a method including principal component analysis, canonical correlation analysis, and multiple regression analysis. Specifically, the compound contents of 30 samples of the above three grades G1 (weak or no salty taste intensity, high quality wine), G2 (medium salty taste intensity, medium quality wine) and G3 (high salty taste intensity, low quality wine) are respectively recorded in SIMCA-P software, the corresponding principal components PC1 and PC2 are calculated, and the footfall point of the sample in a model (such as the PLS-DA score chart in fig. 2) is finally monitored.

FIG. 2 is a plot of PLS-DA t scores for the 2-methyl-3-furanthiol, furfurylthiol, methyl-2-methyl-3-furanyl disulfide and bis (2-methyl-3-furanyl) disulfide content in 30 Maotai-flavor liquor samples, where t 1, t 2 are scores for each sample point over two datasets X and Y spatial weeks of PLS analysis. It can be seen that three kinds of Maotai-flavor liquor samples G1, G2 and G3 with different degrees of salty taste are well separated. The distribution difference of the contents of the four compounds in the sample can cause the salty taste characteristics of the Maotai-flavor liquor with different strengths.

Analysis and verification of salty taste discrimination model

In some embodiments of the present application, the analysis and validation of the salty taste discrimination model is performed using the following methods:

(1) the model was subjected to 20 displacement tests, and the experimental results are shown in the PLS-DA model displacement verification chart of FIG. 3. The X coordinate is the correlation coefficient of the replaced data and the original data, and the Y coordinate is Q²Or R²Value of, wherein Q²To accumulate cross validation, the larger the model, the better the prediction, R²For accumulating variance values, it is indicated how much raw data is available for building a new PLS-DA model, the larger the model, the more powerful the interpretation of the model.

As can be seen from FIG. 3, all R's located on the left side of FIG. 3²And Q²The values (Y-axis data) are all lower than the rightmost R²And Q²Value (reference symbol A in the figure), and Q²RegressionThe Y intercept of the line (marked B in the figure) is a negative value, and the PLS-DA discriminant model has no overfitting phenomenon, so that the discriminant model has better prediction capability.

(2) The established salty taste discrimination model is used for predicting 22 samples tested externally, and the results are shown in table 3. As can be seen from table 3, the total number of samples used for modeling is 22; 7 samples with no or low intensity of salty taste; 7 samples with moderate salty taste intensity; 8 samples with high salty taste intensity. The judgment accuracy of the discrimination model on samples without salty taste or with low salty taste intensity is 6/7-85.71%, the judgment accuracy of samples with medium salty taste intensity is 6/7-85.71%, the judgment accuracy of samples with high salty taste intensity is 6/8-87.5%, and the comprehensive judgment accuracy is (6+6+7)/(7+7+8) -86.36%.

Table 3 discriminant analysis was performed on 22 external validation set samples based on the PLS-DA model of the examples of the present application.

Note: a: representing samples with no or low intensity of salty taste; b: represents samples with moderate salty taste intensity; c: representing samples with greater saltiness intensity.

The above embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited thereto, and any insubstantial changes and substitutions made by those skilled in the art based on the present application are intended to be covered by the present application.