Method for rapidly identifying mixing of Chinese wolfberry primary pulp and dried Chinese wolfberry pulp

Abstract

The invention belongs to the technical field of Chinese wolfberry identification, and particularly relates to a method for quickly identifying the doping of Chinese wolfberry primary pulp with dried Chinese wolfberry pulp, which comprises the following steps: detecting the response value of the odor of inorganic sulfide in the Chinese wolfberry primary pulp, and judging whether the Chinese wolfberry primary pulp is doped with the dried Chinese wolfberry pulp or not by utilizing the response value of the odor of the inorganic sulfide; if the response value is 9.0-13.0, the sample is doped with the dried wolfberry fruit pulp, if the response value is 9.0-13.0, the sample is not doped with the dried wolfberry fruit pulp, and if the smell of the inorganic sulfide is greater, the proportion of the doped dried wolfberry fruit is greater or the dried wolfberry fruit is placed for a longer year, and the quality of the original wolfberry fruit pulp is poorer. The method can quickly and accurately identify whether the dried wolfberry fruits are mixed in the wolfberry primary pulp so as to ensure the quality of the wolfberry primary pulp, directly and quickly identify the adulterated wolfberry primary pulp, and promote the healthy development of the industry.

Description

Technical Field

[0001] The invention belongs to the technical field of wolfberry identification, and particularly relates to a method for quickly identifying wolfberry puree mixed with wolfberry dry fruit puree. Background Art

[0002] Wolfberry puree is a form of processed product that has rapidly emerged in recent years. It uses fresh wolfberry as the only raw material and is made through processes such as pulping, coarse filtration, homogenization, pasteurization, and filling. It is not compounded or blended, so as to preserve the nutritional components and flavor of fresh wolfberry to the greatest extent. It is different from related products on the market, such as wolfberry juice, wolfberry concentrated juice, wolfberry compound fruit puree, etc., and has currently become the main product in the new wolfberry consumer market.

[0003] Ningxia is the origin and main production area of ​​wolfberry puree. In 2020, the production capacity of wolfberry puree in Ningxia reached more than 10,000 tons. From 2021 to 2023, 26 new wolfberry puree / fresh juice production lines will be built in our region, consuming a large amount of seasonal fresh fruit and alleviating the pressure of drying fresh fruit in summer. It has become the fastest-growing area of ​​the wolfberry industry.

[0004] Although wolfberry puree has a good development trend in recent years, the industry is in chaos, the quality is uneven, and the price difference is large. Some companies mix wolfberry dried fruit and complex fruit puree into wolfberry puree to pass off inferior products as good ones, and use their low price advantage to disrupt the market order, affecting the healthy and sustainable development of the wolfberry puree industry. Therefore, it is urgently necessary to invent a method that can identify the dry fruit puree mixed in wolfberry puree to promote the healthy development of the industry. Summary of the invention

[0005] In view of this, the present invention provides a method for quickly identifying whether wolfberry puree is mixed with wolfberry dried fruit puree, so as to solve the technical problems in the prior art that wolfberry puree is mixed with wolfberry dried fruit puree, inferior products are passed off as good ones, and the market order is disrupted by the low price advantage, thus affecting the healthy and sustainable development of the wolfberry puree industry.

[0006] To achieve the above objectives, this application adopts the following scheme:

[0007] A method for rapidly identifying wolfberry puree mixed with wolfberry dried fruit puree comprises the following steps:

[0008] S10. Obtaining a wolfberry puree sample to be tested;

[0009] S20. Detecting the response value of the inorganic sulfide odor of the wolfberry puree sample;

[0010] S30. Use the response value to determine whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp: if the response value is greater than 13.0, the wolfberry puree sample is mixed with wolfberry dry fruit pulp; if the response value is between 9.0 and 13.0, the wolfberry puree sample is not mixed with wolfberry dry fruit pulp.

[0011] Preferably, the inorganic sulfide odor response value of the sample is detected by an electronic nose detection instrument, and the following steps are included:

[0012] S21. The sample to be tested is allowed to stand for a first period of time to make the sample uniform and stable;

[0013] S22. Equilibrate the sample in a water bath at 25±1°C for a second period of time to keep the sample measurement temperature consistent;

[0014] S23. Use an electronic nose detection instrument to detect the odor of the sample and obtain a response value based on the W1W: inorganic sulfide sensor, wherein the detection time is 150s to 180s, the carrier gas is clean air, and the flow rate of the air is 150mL / min to 200mL / min.

[0015] Preferably, the first duration is 30 minutes to 60 minutes.

[0016] Preferably, the second duration is 30 minutes to 35 minutes.

[0017] Preferably, the detection delay time is 960s to 1200s.

[0018] Preferably, judging whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp according to the response value of the inorganic sulfide odor is obtained by the following method:

[0019] S311. Collect the odor data of W1C: toluene aroma components, W5S: nitrogen oxides, W3C: benzene aroma components, W6S: hydrogen, W5C: alkane aromas, W1S: methane, W1W: inorganic sulfides, W2S: ethanol, W2W: organic sulfides, W3S: alkanes of fresh wolfberry puree, wolfberry puree mixed with dried wolfberry puree, and wolfberry puree mixed with other fruit purees;

[0020] S312. A discriminant function is established based on the odor data using the Fisher discriminant method. The discriminant function has the following relational expression:

[0021] Y1=-7429.731X1-32.415X2+4942.350X3+8880.050X4+8628.733X5+129.945X6+68.354X7+71.853X8-526.713X9+466.56X10-8138.591

[0022] Y2=-7364.7X1-29.85X2+4912.279X3+8792.634X4+8201.375X5+109.975X6+62.298X7+71.051X8-481.870X9+457.032X10-7770.401

[0023] Y3=-7812.491X1-29.488X2+4920.438X3+8642.012X4+9045.416X5+129.279X6+79.158X7+72.927X8-529.981X9+373.019X10-8092.290

[0024] Among them, Y1 represents fresh wolfberry pulp, Y2 represents wolfberry pulp mixed with dried wolfberry pulp, Y3 represents wolfberry pulp mixed with other fruit pulps, X1 is W1C: toluene aromatic components, X2 is W5S: nitrogen oxides, X3 is W3C: benzene aromatic components, X4 is W6S: hydrogen, X5 is W5C: alkane aromatics, X6 is W1S: methane, X7 is W1W: inorganic sulfide, X8 is W2S: ethanol, X9 is W2W: organic sulfide, X10 is W3S: alkane.

[0025] S313. Wilks' Lambda was used to test the discriminant function. The results showed that the significance level of the function was less than 0.01, indicating that the discriminant function was extremely significant. The inorganic sulfide odor index could be used to discriminate the samples of wolfberry puree mixed with dry fruit puree.

[0026] Preferably, the method of using the response value of the inorganic sulfide odor to judge whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp is obtained by the following method:

[0027] S31. Collecting wolfberry puree sample data: including wolfberry puree sample odor data (X matrix) and wolfberry puree sample classification information (Y matrix), and performing standardization or normalization preprocessing on the data to eliminate dimensional effects and data heterogeneity;

[0028] S32. Use X matrix and Y matrix to establish OPLS-DA model;

[0029] S33. Calculation of model parameters: The influence of each index on the classification of dried wolfberries was qualitatively evaluated using the loading diagram. The closer the variable (X) was to the classification (Y), the more important the variable was in determining the classification. The difference in odor response promoted the good classification of wolfberry puree prepared with fresh wolfberry and wolfberry puree mixed with dried wolfberry (Y).

[0030] S34. Variable projection importance (VIP) is an indicator that quantitatively measures the degree of influence of variables on classification. It is judged that the VIP value of W1W (inorganic sulfide) is greater than 1.0, indicating that this indicator has a greater impact on the classification of different raw wolfberry purees;

[0031] S34. Model validation: To further verify the reliability of the model, a permutation test was performed at least 200 times. The results showed that the model was not overfitted, indicating that the model was effective.

[0032] S35. Product verification: The wolfberry puree prepared with fresh wolfberry and the wolfberry puree mixed with dried wolfberry are used for verification. The W1W (inorganic sulfide) odor index can be used to distinguish the wolfberry puree samples mixed with dried fruit puree.

[0033] The technical solution adopted in this application can achieve the following beneficial effects:

[0034] The invention provides a method for quickly identifying whether wolfberry raw pulp is mixed with wolfberry dried fruit pulp. The method comprises the following steps: by detecting the response value of the inorganic sulfide odor in the wolfberry raw pulp, and using the response value of the inorganic sulfide odor to judge whether the wolfberry raw pulp is mixed with the wolfberry dried fruit pulp: if the response value is greater than 13.0, the wolfberry dried fruit pulp is mixed with the sample; if the response value is between 9.0 and 13.0, the wolfberry dried fruit pulp is not mixed with the sample; and if the inorganic sulfide odor response value is larger, it indicates that the proportion of the mixed wolfberry dried fruit is larger or the wolfberry dried fruit has been stored for a longer time, and the quality of the wolfberry raw pulp is worse. The method can quickly and accurately identify whether the wolfberry raw pulp is mixed with the wolfberry dried fruit, so as to ensure the quality of the wolfberry raw pulp, directly and quickly identify the inferior wolfberry raw pulp, and promote the healthy development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the odor profile of fresh wolfberry fruit in this application.

[0036] Figure 2 This is the odor profile of the fresh wolfberry fruit puree in this application.

[0037] Figure 3 This is the odor profile of wolfberry fresh fruit puree mixed with wolfberry dried fruit puree in different volume ratios in this application.

[0038] Figure 4 Place the scent profiles of different years for wolfberry dried fruit in this application.

[0039] Figure 5 This is the OPLS-DA score graph in this application.

[0040] Figure 6 This is the OPLS-DA loading diagram in this application.

[0041] Figure 7 This is the distribution diagram of OPLS-DAVIP values ​​in this application.

[0042] Figure 8 This is the OPLS-DAVIP permutation test diagram in this application.

[0043] Fig. 9 Add a score map of unknown samples to OPLS-DAVIP in this application.

[0044] Fig.10 This is the classification function coefficient table in this application. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the accompanying drawings. And the preferred implementation of the present application is given. However, the present application can be implemented in many different forms and is not limited to the implementation described herein. On the contrary, the purpose of providing these implementations is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0047] A method for rapidly identifying wolfberry puree mixed with wolfberry dried fruit puree comprises the following steps:

[0048] S10. Obtaining a wolfberry puree sample to be tested;

[0049] S20. Detecting the response value of the inorganic sulfide odor of the wolfberry puree sample;

[0050] S30. Use the response value to determine whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp: if the response value is greater than 13.0, the wolfberry puree sample is mixed with wolfberry dry fruit pulp; if the response value is between 9.0 and 13.0, the wolfberry puree sample is not mixed with wolfberry dry fruit pulp.

[0051] Specifically, the inorganic sulfide odor response value of the sample is detected by using an electronic nose detection instrument, and the following steps are included:

[0052] S21. The sample to be tested is allowed to stand for a first period of time to make the sample uniform and stable;

[0053] S22. Equilibrate the sample in a water bath at 25±1°C for a second period of time to keep the sample measurement temperature consistent;

[0054] S23. Use an electronic nose detection instrument to detect the odor of the sample and obtain a response value based on the W1W: inorganic sulfide sensor, wherein the detection time is 150s to 180s, the carrier gas is clean air, and the flow rate of the air is 150mL / min to 200mL / min.

[0055] Among them, the first time length is 30 minutes to 60 minutes, the second time length is 30 minutes to 35 minutes, and the detection delay time length is 960 seconds to 1200 seconds.

[0056] In this example, 9 indicators including main nutritional ingredients, viscosity, color, flavor, etc. of 46 wolfberry puree products produced by 16 companies on the market were measured. The results showed that the wolfberry puree samples generally showed good wolfberry nutrition and flavor characteristics, but the quality of different products varied greatly, with pH ranging from 4.04 to 4.62, viscosity ranging from 6.63 to 16.60 cP, soluble solids ranging from 12.77% to 30.63%, total sugar content ranging from 93.19 to 220.26 mg / g, flavonoid content ranging from 23.43 to 87.27 μg / g, and total carotenoid content ranging from 3. The samples were between 23 and 1579.47 μg / g, and the overall color was bright orange-red. The samples were similar in flavor, but had large differences in odor. The main differences were that the odor response values ​​of the sensors W1W (inorganic sulfide), W1S (methane), W2S (ethanol), and W5S (nitrogen oxides) were large. However, when the wolfberry pulp was mixed with wolfberry dried fruit pulp of different proportions and different years, the differences in W1S (methane) and W2S (ethanol) fluctuated (either If the odor response value is used to judge whether wolfberry and wolfberry pulp is mixed with wolfberry dried fruit, it is too complicated and the accuracy is not high; when wolfberry pulp is mixed with wolfberry dried fruit pulp of different years, the odor response value of the W5S (nitrogen oxide compound) sensor is slightly different. If the odor response value is used to judge whether wolfberry and wolfberry pulp is mixed with wolfberry dried fruit, it is considered that there will be errors during the detection due to other factors such as detection conditions, which will also affect the identification result; the difference between the response value of the W1W (inorganic sulfide) sensor and the response value of the W1W (inorganic sulfide) sensor of the fresh wolfberry pulp is the largest, and with the increase of the proportion of the mixed wolfberry dried fruit pulp and the longer the placement time of the mixed wolfberry dried fruit pulp, the response value tends to increase, and the difference is obvious, which is convenient for identification and has higher accuracy.

[0057] In this embodiment, if the inorganic sulfide response value is greater than 13.0, the sample is adulterated with wolfberry dry fruit pulp; if the inorganic sulfide response value is between 9.0 and 13.0, the sample is not adulterated with wolfberry dry fruit pulp. This method can quickly and accurately identify whether wolfberry dry fruit is adulterated in wolfberry puree, so as to ensure the quality of wolfberry puree, directly and quickly identify inferior wolfberry puree, and promote the healthy development of the industry.

[0058] The following specific experimental examples are used to further illustrate the technical solutions and technical effects of the present invention. It should be noted that the following experimental examples are only for further explaining the present invention and do not limit the technical solutions of the present invention.

[0059] Experimental Materials and Methods

[0060] Experimental Materials

[0061] 6 different varieties of fresh wolfberry: Ningqi No. 1, Ningqi No. 5, Ningqi No. 7, Ningqi No. 10, 7-8, 14-02;

[0062] Dried wolfberry fruits of different years: 1 year, 2 years, and 3 years.

[0063] Experimental methods

[0064] The experiment was divided into 7 treatment groups, namely blank example, test example 1, comparative example 1, test example 2, comparative example 2, test example 3, comparative example 3. Different wolfberry purees were prepared through the 7 treatment groups, and the odor response values ​​of the prepared different wolfberry purees were tested.

[0065] Blank example

[0066] In this blank case, AIRSENSE PEN3 electronic nose instrument was used to detect the odor profiles of the above-mentioned Ningqi No. 1, Ningqi No. 5, Ningqi No. 7, Ningqi No. 10, 7-8, 14-02, and the wolfberry fresh fruits of the six varieties mixed in the ratio of 1:1:1:1:1:1. The test results are as follows Figure 1 shown.

[0067] Experimental Example 1

[0068] Preparing samples to be tested: using the above 6 different varieties of wolfberry fresh fruits to prepare 6 kinds of wolfberry puree samples according to a unified process, and mixing the 6 different varieties of wolfberry fresh fruit purees in a ratio of 1:1:1:1:1:1 to prepare wolfberry puree, to obtain mixed variety wolfberry fresh fruit puree samples, and a total of 7 kinds of wolfberry puree samples were obtained;

[0069] 20 mL was accurately measured from the above 7 wolfberry puree samples, respectively, and transferred to 50 mL standard headspace bottles, and allowed to stand for 30 min to make the samples uniform and stable; the samples were balanced in a water bath at 25±1°C for 30 min to keep the sample measurement temperature consistent to avoid errors caused by temperature fluctuations in the measurement. The inorganic sulfide odor response values ​​of the 7 samples were detected using the AIRSENSE PEN3 electronic nose instrument, with a measurement time of 180 s, a delay time of 960 s, a carrier gas of clean air, and a flow rate of 200 mL / min. The test results are as follows: Figure 2 shown.

[0070] Depend on Figure 2 It can be seen that the odor profiles of wolfberry purees prepared from fresh fruits of 7 different wolfberry varieties are consistent, but the W1W (inorganic sulfide) are significantly different. Among them, the response values ​​of W1W (inorganic sulfide) of the 7 samples are all between 9.0 and 13.0.

[0071] Comparative Example 1

[0072] The difference between this comparative example 1 and the above-mentioned test example 1 is that the odor response values ​​of the W1C, W5S, W3C, W6S, W5C, W1S, W2S, W2W and W3S sensors of the seven samples are respectively detected by using the AIRSENSE PEN3 electronic nose instrument. The results are as follows: Figure 2 As shown;

[0073] The maximum values ​​of the odor response values ​​on the W1C, W5S, W3C, W6S, W5C, W1S, W2S, W2W and W3S sensors of the above 7 samples were counted, and the difference between the maximum value of the response value on each sensor and the maximum value of each odor response value in the blank case was calculated. The results are shown in Table 1:

[0074] Table 1 Statistics of odor response values ​​in Comparative Example 1

[0075] project W1C W5S W3C W6S W5C W1S W2S W2W W3S Maximum 0.4 6.3 0.6 1.3 0.7 9.5 11.0 5.5 1.8 Difference 0 -1.9 0 -0.2 0 1.3 -1.5 0.3 -0.3

[0076] Depend on Figure 2 As can be seen from Table 1, the odor profiles of wolfberry pulp prepared from the fresh fruits of 6 different wolfberry varieties are consistent, but the differences in W1S (methane), W2S (ethanol), and W5S (nitrogen oxides) are also quite obvious. It can be preliminarily judged whether the fresh wolfberry pulp is adulterated with the dried wolfberry pulp based on the response values ​​of W1S (methane), W2S (ethanol), and W5S (nitrogen oxides);

[0077] Depend on Figure 2 It also reflects that the sum of the odor response values ​​of Ningqi No. 7 variety on each sensor is the largest compared with the sum of the odor response values ​​of other varieties on each sensor.

[0078] Experimental Example 2

[0079] The difference between Experimental Example 2 and Experimental Example 1 is that: the wolfberry dried fruit (stored for two years) of the Ningqi No. 7 wolfberry variety is rehydrated to prepare wolfberry dried fruit pulp, and the wolfberry fresh fruit pulp is prepared using the Ningqi No. 7 wolfberry variety, and the wolfberry dried fruit pulp and the wolfberry fresh fruit pulp are evenly mixed according to different volume ratios, and the volume ratios of the wolfberry dried fruit pulp and the wolfberry fresh fruit pulp are respectively: 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, and 9 kinds of wolfberry original pulp samples mixed with different proportions are obtained respectively;

[0080] The inorganic sulfide odors of the nine samples were detected by using the AIRSENSE PEN3 electronic nose instrument. The determination steps and conditions were the same as those in the above-mentioned Experimental Example 1. The detection results are shown in FIG. Figure 3 As shown, the difference between the inorganic sulfide odor response values ​​of the 9 samples and the inorganic sulfide odor response values ​​of the Ningqi No. 7 wolfberry variety in the above Example 1 was statistically analyzed, and the statistical results are shown in Table 2.

[0081] Table 2 Statistical table of odor response values ​​of inorganic sulfide in Test Example 2

[0082]

[0083] Depend on Figure 3 As can be seen from the data in Table 2, after the wolfberry dried fruit (stored for two years) of the Ningqi No. 7 wolfberry variety was rehydrated to obtain wolfberry dried fruit pulp, and the wolfberry dried fruit pulp was mixed with the wolfberry fresh fruit pulp according to different volume ratios, the inorganic sulfide odor response values ​​of the 9 samples were all greater than 13.0;

[0084] And as the proportion of dried wolfberry added increases, the corresponding inorganic sulfide odor response value also becomes larger and larger.

[0085] Comparative Example 2

[0086] The difference between this comparative example 2 and the above experimental example 2 is that: the response values ​​of the W1S (methane), W2S (ethanol), and W5S (nitrogen oxides) sensors are detected, and the other methods and steps are the same as those in the above experimental example 2. The detection results are as follows: Figure 3 As shown, the maximum values ​​of the odor response values ​​of the W1S (methane), W2S (ethanol), and W5S (nitrogen oxide) sensors and the difference values ​​between the corresponding odor response values ​​in the above-mentioned test example 1 are respectively counted, and the results are shown in Table 3:

[0087] Table 3 Statistics of odor response values ​​in Comparative Example 2

[0088]

[0089] Depend on Figure 3 From the data in Table 3, it can be seen that although the maximum response values ​​of the W5S, W1S and W2S sensors are significantly different from the maximum response values ​​of the corresponding sensors in Comparative Example 1, when the volume ratio of wolfberry dry fruit pulp to wolfberry fresh fruit pulp is 8:2, the response value of the W5S sensor is the largest compared with the response values ​​of the W5S sensor at other volume ratios; when the volume ratio of wolfberry dry fruit pulp to wolfberry fresh fruit pulp is 3:7, the response value of the W1S sensor is the largest compared with the response values ​​of the W2S sensor at other volume ratios. The response value on the 1S sensor is the largest. When the volume ratio of wolfberry dry fruit pulp to wolfberry fresh fruit pulp is 8:2, the response value on the W2S sensor is the largest compared with the response values ​​on the W2S sensor at other volume ratios. There is no regular pattern to follow. This shows that when the volume of wolfberry dry fruit pulp mixed with wolfberry pulp changes, when the response values ​​on the W5S, W1S and W2S sensors are used to identify whether wolfberry dry fruit pulp is mixed into the wolfberry pulp, the identification process is more complicated and the error is larger, resulting in inaccurate test results.

[0090] Experimental Example 3

[0091] The difference between Experimental Example 3 and Experimental Example 2 is that the storage years of the wolfberry dried fruit in the mixed wolfberry dried fruit pulp are changed, wherein the volume ratio of the wolfberry dried fruit pulp to the wolfberry fresh fruit pulp is 9:1, and the storage years are 1 year and 3 years respectively. The other steps and methods are the same as those in Experimental Example 2. The detection results of the inorganic sulfide odor response value are as follows: Figure 4 As shown:

[0092] Depend on Figure 4 It can be seen that the W1W sulfide odor response value of the wolfberry puree mixed with wolfberry dried fruit paste prepared when the wolfberry dried fruit is stored for 1 year and 3 years is greater than 13.0, and as the storage year of the wolfberry dried fruit is longer, the response value is larger. The W1W sulfide odor response value of the wolfberry dried fruit paste stored for 3 years is 25.3, which is 12.6 different from the W1W sulfide odor response value of the wolfberry fresh fruit paste in Example 1.

[0093] Comparative Example 3

[0094] The difference between this comparative example 3 and the above experimental example 3 is that: the response values ​​of the W5S, W1S and W2S sensors are detected, and the other methods and steps are the same as those in the above experimental example 3. The detection results are as follows: Figure 4 As shown, the maximum values ​​of the odor response values ​​of different sensors and the difference values ​​between each maximum value and the corresponding odor response value in the above-mentioned test example 1 are respectively counted, and the results are shown in Table 4:

[0095] Table 4 Statistics of odor response values ​​in Comparative Example 3

[0096] project W5S W1S W2S Maximum 7.1 7.6 11.2 Difference 0.8 -1.9 0.2

[0097] Depend on Figure 4 It can be seen from the data in Table 3 that when the adulterated wolfberry dried fruit is stored for 3 years, the response value of the W1S sensor is reduced compared with the response value of the W1S sensor of the wolfberry fresh fruit paste, indicating that the response value of the W1S sensor changes with the years of storage of the wolfberry dried fruit, and there is no regularity to follow. Therefore, if the response value of the W1S sensor is used, it is impossible to accurately identify whether the wolfberry fresh fruit is adulterated with the wolfberry dried fruit;

[0098] Although the response value of the W2S sensor is different from that of the W2S sensor for fresh wolfberry pulp, Figure 4 It can be seen that the response value of the sensor of the wolfberry puree mixed with wolfberry dried fruit that has been stored for 1 year is larger than the response value of the sensor of the wolfberry puree mixed with wolfberry dried fruit that has been stored for 2 years. This shows that the response value of the W2S sensor changes with the years of storage of wolfberry dried fruit, and there is no regular pattern. Therefore, if the response value of the W2S sensor is not accurate, it is impossible to identify whether the wolfberry fresh fruit is mixed with wolfberry dried fruit.

[0099] However, the difference between the response value of the W5S sensor and the response value of the W5S sensor for fresh wolfberry pulp is small. Considering that there will be errors during the detection due to other factors such as the detection conditions, it will also affect the identification results.

[0100] In summary, the difference between the response value of the W1W sensor and the response value of the W1W sensor of fresh wolfberry pulp is the largest, and with the increase of the proportion of the mixed wolfberry dry fruit pulp and the longer the storage time of the dried wolfberries used to prepare the mixed wolfberry dry fruit pulp, the response value tends to increase, and the difference is obvious, which is convenient for identification and has higher accuracy.

[0101] Please see Fig.10 Based on the odor data detected by the electronic nose odor detector, the Fisher discriminant method was used to establish the discriminant function. The first typical discriminant was used in the analysis, with a variance explanation of 100% and a canonical correlation of 0.994. The canonical correlation coefficient represents the correlation between different groups and the first discriminant function. The stronger the correlation, the greater the difference between the groups in this dimension; conversely, the smaller the difference between the groups in this dimension. The above results show that the function can effectively discriminate and group samples, as shown in Table 5:

[0102] Table 5 Function eigenvalues ​​of typical discriminants based on odor

[0103] function Eigenvalue variance% accumulation% Regular correlation 1 <![CDATA[83.960 a ]]> 100.0 100.0 0.994

[0104] The established discriminant function was used to identify the results in the above embodiments and comparative examples, and the discrimination accuracy was 100%. The Wilks' Lambda test was used for the above unique discriminant function, and the results showed that the significance level of function 1 was 0.000 (<0.01). As shown in Table 6, it is believed that discriminant function 1 is extremely significant. Therefore, function 1 is effective and can be used to discriminate different raw pulp sample groups. The analysis results based on the stepwise discriminant method show that the odor index can be used as a key indicator for discriminating adulterated dry fruit pulp, and the accuracy rate is 100%.

[0105] Table 6 Lambda test based on Wilks

[0106] Function Test Wilks' Lambda Chi-square df Sig. 1 0.012 46.643 100.0 0.000

[0107] The Fisher discriminant method is used to project the multiple sensor response values ​​of wolfberry puree odor into one-dimensional space, and classification and judgment are performed based on the projection values, thereby establishing a typical discriminant formula to determine whether the sample is mixed with dry fruit pulp. The following is the discriminant function of different types of wolfberry puree:

[0108] Y1=-7429.731X1-32.415X2+4942.350X3+8880.050X4+8628.733X5+129.945X6+68.354X7+71.853X8-526.713X9+466.56X10-8138.591

[0109] Y2=-7364.7X1-29.85X2+4912.279X3+8792.634X4+8201.375X5+109.975X6+62.298X7+71.051X8-481.870X9+457.032X10-7770.401

[0110] Y3=-7812.491X1-29.488X2+4920.438X3+8642.012X4+9045.416X5+129.279X6+79.158X7+72.927X8-529.981X9+373.019X10-8092.290

[0111] Among them, Y1 represents fresh wolfberry pulp, Y2 represents wolfberry pulp mixed with dried wolfberry pulp, Y3 represents wolfberry pulp mixed with other fruit pulps, X1 is W1C: toluene aromatic components, X2 is W5S: nitrogen oxides, X3 is W3C: benzene aromatic components, X4 is W6S: hydrogen, X5 is W5C: alkane aromatics, X6 is W1S: methane, X7 is W1W: inorganic sulfide, X8 is W2S: ethanol, X9 is W2W: organic sulfide, X10 is W3S: alkane.

[0112] The orthogonal partial least squares discriminant analysis (OPLSDA) method was used to establish the model, and the OPLS-DA method was used to qualitatively evaluate the quality of wolfberry. The modeling process included the following steps:

[0113] (1) Collect sample data

[0114] Including sample odor data (X matrix) and sample classification information (Y matrix), the data is standardized or normalized preprocessed to eliminate dimension effects and data heterogeneity.

[0115] (2) Use X matrix and Y matrix to establish OPLS-DA model

[0116] See also Figure 5 and Figure 6 The results show that R 2 Y and Q 2 The values ​​were 0.952 and 0.876 respectively, and the model had good explanatory power and good fit. The three groups of wolfberry fresh pulp, wolfberry fresh-dry pulp and other pulp were well separated, showing clustering within the group and alienation between the groups.

[0117] (3) Model parameter calculation

[0118] The loading diagram can qualitatively evaluate the influence of each index on the classification of stems. The closer the variable (X) is to the classification (Y), the more important the variable is in determining the classification. Figure 6 As shown, the difference in odor response led to the good classification of wolfberry paste and other fruit paste samples with different raw materials (Y). W5S was sensitive to distinguish other fruit pastes, and W1W was sensitive to distinguish samples mixed with wolfberry dried fruit paste.

[0119] Variable projection importance (VIP) is an indicator that quantitatively measures the influence of variables on classification. The larger the VIP value, the greater the influence of the variable on sample classification. Figure 7 As shown, the VIP values ​​from large to small are: W5S>W6S>W1W>W1C>W5C>W2S>W3C>W2W>W1S>W3S, among which, the VIP values ​​of W5S, W6S, W1W and W1C are all greater than 1.0, indicating that these four indicators have a greater influence on the classification of wolfberry paste with different raw materials.

[0120] (4) Model verification

[0121] In order to further verify the reliability of the model, a permutation test was used for verification. The results of the permutation test (200 times) are as follows Figure 8 As shown, Q 2 The intercept on the y-axis is a negative value, indicating that the model is not overfitting and is effective.

[0122] (5) Product Verification

[0123] The samples in the above test examples and comparative examples were verified, and the results are as follows Fig. 9 ( Fig. 9 The results of the above-mentioned test examples and comparative examples are consistent with those of the above-mentioned test examples and comparative examples.

[0124] This fully demonstrates that the samples of wolfberry puree mixed with dry fruit puree can be identified based on the odor index, and W1W is sensitive in identifying the samples mixed with wolfberry dry fruit puree.

[0125] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree, characterized in that: The following steps are involved: S10. Obtaining a wolfberry puree sample to be tested; S20. Detecting the response value of the inorganic sulfide odor of the wolfberry puree sample; S30. Use the response value to determine whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp: if the response value is greater than 13.0, the wolfberry puree sample is mixed with wolfberry dry fruit pulp; if the response value is between 9.0 and 13.0, the wolfberry puree sample is not mixed with wolfberry dry fruit pulp.

2. The method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree according to claim 1, characterized in that: The electronic nose detection instrument is used to detect the response value of the inorganic sulfide odor of the sample, and the steps include: S21. The sample to be tested is allowed to stand for a first period of time to make the sample uniform and stable; S22. Equilibrate the sample in a water bath at 25±1°C for a second period of time to keep the sample measurement temperature consistent; S23. Use an electronic nose detection instrument to detect the odor of the sample and obtain a response value based on the W1W: inorganic sulfide sensor, wherein the detection time is 150s to 180s, the carrier gas is clean air, and the flow rate of the air is 150 mL / min to 200 mL / min.

3. The method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree according to claim 2, characterized in that: The first duration is 30 min to 60 min.

4. The method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree according to claim 2, characterized in that: The second duration is 30 min to 35 min.

5. The method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree according to claim 2, characterized in that: The delay time during detection ranges from 960 s to 1200 s.

6. The method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree according to claim 1, characterized in that: Judging whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp according to the response value of the inorganic sulfide odor is obtained by the following method: S311. Collect the odor data of W1C: toluene aroma components, W5S: nitrogen oxides, W3C: benzene aroma components, W6S: hydrogen, W5C: alkane aromas, W1S: methane, W1W: inorganic sulfides, W2S: ethanol, W2W: organic sulfides, W3S: alkanes of fresh wolfberry puree, wolfberry puree mixed with dried wolfberry puree, and wolfberry puree mixed with other fruit purees; S312. A discriminant function is established based on the odor data using the Fisher discriminant method. The discriminant function has the following relational expression: Y1=-7429.731X1-32.415X2+4942.350X3+8880.050X4+8628.733X5+129.945X6+68.354X7+71.853X8-526.713X9+466.56X10-8138.591 Y2=-7364.7X1-29.85X2+4912.279X3+8792.634X4+8201.375X5+109.975X6+62.298X7+71.051X8-481.870X9+457.032X10-7770.401 Y3=-7812.491X1-29.488X2+4920.438X3+8642.012X4+9045.416X5+129.279X6+79.158X7+72.927X8-529.981X9+373.019X10-8092.290 Among them, Y1 represents fresh wolfberry pulp, Y2 represents wolfberry pulp mixed with dried wolfberry pulp, Y3 represents wolfberry pulp mixed with other pulps, X1 is W1C: toluene aromatic components, X2 is W5S: nitrogen oxides, X3 is W3C: benzene aromatic components, X4 is W6S: hydrogen, X5 is W5C: alkane aromatics, X6 is W1S: methane, X7 is W1W: inorganic sulfide, X8 is W2S: ethanol, X9 is W2W: organic sulfide, X10 is W3S: alkane; S313. Wilks' Lambda was used to test the discriminant function. The results showed that the significance level of the function was less than 0.01, indicating that the discriminant function was extremely significant. The inorganic sulfide odor index could be used to discriminate the samples of wolfberry puree mixed with dry fruit puree.

7. The method for rapidly identifying wolfberry puree mixed with wolfberry dry fruit puree according to claim 1, characterized in that: Judging whether the wolfberry puree sample is mixed with wolfberry dry fruit pulp according to the response value of the inorganic sulfide odor can also be obtained by the following method: S321. Collecting wolfberry puree sample data: including wolfberry puree sample odor data (X matrix) and wolfberry puree sample classification information (Y matrix), and performing standardization or normalization preprocessing on the data to eliminate dimension effects and data heterogeneity; S322. Establish an OPLS-DA model using X matrix and Y matrix; S323. Calculation of model parameters: Use the loading diagram to qualitatively evaluate the influence of each index on the classification of dried wolfberries. The closer the variable (X) is to the classification (Y), the more important the variable is in determining the classification. The difference in odor response promotes the good classification of wolfberry puree prepared with fresh wolfberry and wolfberry puree mixed with dried wolfberry (Y). S324. Variable projection importance (VIP) is an indicator that quantitatively measures the degree of influence of variables on classification. The VIP value of inorganic sulfide is greater than 1.0, indicating that this indicator has a greater impact on the classification of different raw materials of wolfberry puree; S325. Model validation: To further verify the reliability of the model, the permutation test was performed at least 200 times. The results showed that the model was not overfitted, indicating that the model was effective. S326. Product verification: Verification is carried out using wolfberry puree prepared from fresh wolfberry fruits and wolfberry puree mixed with dried wolfberry fruits. The inorganic sulfide odor index can be used to identify wolfberry puree samples mixed with dried fruit puree.

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