Estimation method of starch content in cigar tobacco leaf airing process

Abstract

The invention relates to a method for estimating starch content in a cigar tobacco leaf airing process. Comprising the following steps: detecting color parameters of the front side and the back side of the cigar tobacco in the airing process by using a portable colorimeter, determining the starch content of the cigar tobacco in different airing stages, performing correlation analysis on data obtained in the previous step, performing linear stepwise regression analysis on the color parameters and starch on the basis of the data obtained in the previous step, and determining the starch content of the cigar tobacco. Establishing a starch content estimation model based on color parameters, verifying the established prediction model, and determining the starch content of the cigar tobacco leaves by using the verified prediction model. According to the method disclosed by the invention, the correlation between the color change of the tobacco leaves and the starch in the cigar tobacco leaf airing process is determined, and the estimation model is established, so that the starch content of the tobacco leaves is quickly and nondestructively detected in real time, and reference can be provided for improving the cigar tobacco leaf airing quality and optimizing the tobacco leaf airing process research.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tobacco quality evaluation, in particular to a method for estimating starch content in the airing process of cigar tobacco leaves. BACKGROUND

[0002] With the airing of tobacco leaves, most of the starch in the tobacco leaves will be degraded into glucose, and a small amount will be decomposed into intermediate product dextrin. The free sugar produced by starch degradation can react with amino acids in the Maillard reaction to produce a series of aroma precursors, which is one of the main sources of tobacco aroma. If the starch degradation is not sufficient, the residual starch and dextrin in the tobacco leaves will not only be detrimental to the color, aroma and taste of the tobacco leaves, but also affect the burning speed and completeness of the cigarette. Therefore, whether the starch is sufficiently degraded is an important indicator for evaluating the quality of tobacco leaves. At present, common methods for analyzing the starch content of tobacco leaves include acid hydrolysis, enzymatic hydrolysis, iodine colorimetry, liquid chromatography and continuous flow method. These methods have limitations such as complex operation, high professional requirements, and delayed data acquisition, and are not suitable for real-time and rapid detection of starch content in the airing process of cigar tobacco leaves.

[0003] The CIE-L*a*b* color space system is currently the most complete color model for describing the colors visible to the naked eye, mainly including three parameters of brightness value L*, red-green value a* and yellow-blue value b*. It has been widely used in tobacco planting, curing, grading, etc. due to its advantages of easy-to-accept color expression and uniform color description. The airing process of cigar tobacco leaves is a starvation metabolism process, accompanied by the degradation of macromolecules such as proteins and starches. The degradation rate of starch in cigar tobacco leaves after airing can reach about 60%. Studies have shown that during the airing process of cigar tobacco leaves, the color change of the tobacco leaves has significant correlation with chemical components such as total sugar, reducing sugar and nicotine, which can reflect the intrinsic chemical quality of the tobacco leaves. At present, the correlation between the color change of the tobacco leaves and starch during the airing process of cigar tobacco leaves has not been clearly defined. The airing process is the main stage of starch degradation in cigar tobacco leaves. Defining the correlation between the color change of the tobacco leaves and starch during the airing process of cigar tobacco leaves and establishing an estimation model can realize real-time, rapid and non-destructive detection of the starch content of the tobacco leaves, which can provide a reference for improving the airing quality of cigar tobacco leaves and optimizing the airing process of the tobacco leaves. SUMMARY

[0004] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a real-time, rapid and non-destructive method for estimating the starch content in the airing process of cigar tobacco leaves.

[0005] To achieve the above-mentioned purpose, the present application is realized by the following scheme:

[0006] A method for estimating the starch content in the airing process of cigar tobacco leaves, characterized in that it comprises the following steps:

[0007] S1: detecting color parameters of the front and back of the cigar leaf during the airing process by using a portable color difference meter;

[0008] S2: measuring the starch content of the cigar leaf at different stages of the airing process;

[0009] S3: performing correlation analysis on the data obtained in S1 and S2;

[0010] S4: performing linear stepwise regression analysis of the color parameters and the starch based on the data obtained in S3, and establishing a starch content estimation model based on the color parameters;

[0011] S5: verifying the prediction model established in S4;

[0012] S6: measuring the starch content of the cigar leaf by using the verified prediction model.

[0013] In one of the embodiments, the color parameters in S1 are the brightness value L*, the red-green value a* and the yellow-blue value b*.

[0014] In one of the embodiments, the detection method in S1 is to measure the brightness value L*, the red-green value a* and the yellow-blue value b* at 6 sites on the front and back of each leaf, and the actually measured brightness value L*, the red-green value a* and the yellow-blue value b* of the front and back of the cigar leaf are the average values of the brightness value L*, the red-green value a* and the yellow-blue value b* of the corresponding 6 sites on the front and back of the cigar leaf.

[0015] In one of the embodiments, the determination method in S2 is the acid hydrolysis-DNS method.

[0016] In one of the embodiments, the correlation analysis in S3 is to calculate the Pearson correlation coefficient and significance of the starch content and the color parameters according to the sample set data.

[0017] In one of the embodiments, the verification method of S5 is to verify the reliability of the prediction model established in S4 by using the verification set data.

[0018] In one of the embodiments, the determination of the starch content of the cigar leaf by using the verified prediction model in S6 is to input the a* value of the front of the cigar leaf as the input value, output the corresponding starch content of the cigar leaf by the prediction model established in S4, and realize the determination of the starch content of the cigar leaf.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. The determination method of the present application is suitable for real-time and rapid detection of the starch content of the cigar leaf during the airing process.

[0021] 2, The determination method of the application determines the correlation between the color change of cigar leaf during the curing process and starch, and establishes an estimation model, so that the real-time, rapid and non-destructive detection of the starch content of the tobacco leaf is realized, which can provide a reference for improving the curing quality of the cigar leaf and optimizing the curing process of the tobacco leaf.

[0022] In order to better understand and implement, the application will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The step flow chart of the application;

[0024] Figure 2 The color parameter measurement schematic diagram of S1 of the application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0026] As Figure 1 The application provides a method for estimating the starch content of cigar leaf during the curing process. The color parameters of the cigar leaf are used as input values, the starch content corresponding to the cigar leaf is used as output values, a starch content estimation model based on the color parameters is established, so that the starch content of the cigar leaf is fitted and the accuracy of the model is verified. Under the premise of keeping the cigar leaf intact, the real-time and rapid detection of the starch content of the cigar leaf is realized, and good accuracy is ensured.

[0027] The estimation method of the application specifically includes the following steps:

[0028] S1: Detecting the color parameters of the front and back of the cigar leaf during the curing process by using a portable color difference meter.

[0029] The portable color difference meter is a CR-10Plus portable color difference meter (KONICA), and the color parameters are brightness value L*, red-green value a* and yellow-blue value b*. Specifically, the brightness value L*, the red-green value a* and the yellow-blue value b* of 6 sites on the front and back of each tobacco leaf are measured, and the actually measured brightness value L*, the red-green value a* and the yellow-blue value b* of the front and back of the cigar leaf are the average values of the brightness value L*, the red-green value a* and the yellow-blue value b* of the corresponding 6 sites on the front and back of the cigar leaf.

[0030] The selection of the measurement sites on the front and back of each tobacco leaf is as shown in the figure. Figure 2 ​

[0031] S2: The starch content of the air-cured cigar leaf at different stages was determined by acid hydrolysis-DNS method. The color parameters and starch content of the sample set are shown in Table 1.

[0032]

[0033] Table 1 Color parameters and starch content of air-cured cigar leaf at different stages

[0034] S3: Correlation analysis was performed on the data obtained in S1 and S2.

[0035] In this example, the Pearson correlation coefficient and significance of the starch content and color parameters were calculated according to the sample set data, and the results are shown in Table 2. It can be seen that the starch content is significantly negatively correlated with the a* value of the front / back of the tobacco leaf.

[0036]

[0037] Table 2 Correlation analysis results of tobacco starch content and color parameters

[0038] S4: Based on the data obtained in S3, linear stepwise regression analysis of color parameters and starch was performed to establish a starch content estimation model based on color parameters.

[0039] According to the results obtained in S3, linear stepwise regression analysis was performed with starch content as the dependent variable and the a* value of the front / back of the tobacco leaf as the independent variable. The analysis was performed twice with input or removal, and the front a* value was selected as the input variable to successfully construct the model. The adjusted R-square of the model was 0.738, with high goodness of fit. The goodness of fit data of the linear stepwise regression equation is shown in Table 3, and the coefficients and significance of the linear stepwise regression equation are shown in Table 4. According to the coefficient test results, the regression equation is Y 淀粉 = 4.622-0.129Xfront a*.

[0040] Model R R-squared Adjusted R-squared Standard error of estimate Durbin-Watson 1 .881a 0.776 0.738 0.86348 1.455

[0041] Table 3 Goodness of fit of linear stepwise regression equation

[0042]

[0043] Table 4 Coefficients and significance of linear stepwise regression equation

[0044] S5: The prediction model established in S4 was verified.

[0045] Specifically, the reliability of the prediction model established in S4 is verified by using the verification set data, and the prediction value of the prediction model and the measured value of the verification set data are shown in Table 5. The error between the measured value and the prediction value is controlled within 10% in total, and the prediction accuracy is relatively high.

[0046] Tobacco sample Front a* Predicted value Observed value Error (%) Stage 1 -8.66 5.74 6.38 10.03 Stage 2 .6.95 5.52 4.86 9.09 Stage 1 -1.58 4.83 4.15 8.54 Stage 2 5.76 3.88 3.52 7.18 Stage 1 9.68 3.37 2.94 7.32 Stage 2 14.63 2.73 3.17 8.33 Stage 1 17.83 2.32 2.4 9.43 Stage 2 19.05 2.16 2.3 4.85

[0047] Table 5 Verification of the prediction model

[0048] S6: The starch content of the cigar tobacco leaf is determined by using the verified prediction model. The a* value of the front surface of the cigar tobacco leaf is taken as the input value, and the prediction model established in S4 outputs the corresponding starch content of the cigar tobacco leaf, so as to realize the determination of the starch content of the cigar tobacco leaf.

[0049] The above-described embodiment only expresses one embodiment of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, and the present application also intends to include these modifications and improvements.

Claims

1. A method for estimating starch content in a cigar leaf curing process, characterized by, It comprises the following steps: S1: detecting the color parameters of the front and back of the cigar leaf during the curing process by using a portable color difference meter; S2: measuring the starch content of the cigar leaf at different stages of the curing process; S3: performing correlation analysis on the data obtained from S1 and S2; S4: performing linear stepwise regression analysis of the color parameters and starch content based on the data obtained from S3, and establishing a starch content estimation model based on the color parameters; S5: verifying the prediction model established in S4; S6: measuring the starch content of the cigar leaf by using the verified prediction model.

2. The method for estimating starch content in a cigar leaf curing process according to claim 1, characterized in that: The color parameters in S1 are the brightness value L*, the red-green value a*, and the yellow-blue value b*.

3. The method of claim 2, wherein: The detection method in S1 is to measure the brightness value L*, the red-green value a*, and the yellow-blue value b* at 6 sites on the front and back of each leaf, and the actual measured brightness value L*, the red-green value a*, and the yellow-blue value b* on the front and back of the cigar leaf are the average values of the brightness value L*, the red-green value a*, and the yellow-blue value b* at the corresponding 6 sites on the front and back of the cigar leaf.

4. The method of claim 1, wherein: The determination method in S2 is the acid hydrolysis-DNS method.

5. The method of claim 1, wherein: The correlation analysis in S3 is to calculate the Pearson correlation coefficient and significance of the starch content and the color parameters according to the sample set data.

6. The method of claim 1, wherein: The verification method of S5 is to verify the reliability of the prediction model established in S4 by using the verification set data.

7. The method of claim 1, wherein: In S6, the starch content of the cigar leaf is determined by using the verified prediction model, which takes the a* value of the front of the cigar leaf as the input value and outputs the corresponding starch content of the cigar leaf through the prediction model established in S4, thereby realizing the determination of the starch content of the cigar leaf.

8. The use of the method for estimating the starch content of the cigar leaf during the curing process according to any one of claims 1-7 in the determination of the starch content of the cigar leaf.

Images