A method for rapid analysis of the quality stability of tobacco liquid preparation

Abstract

The present invention discloses a method for rapidly analyzing the stability of the preparation quality of tobacco liquids, comprising collecting near-infrared spectra of multiple qualified liquid samples of different brands and measuring their total water-soluble sugar content; constructing a near-infrared quantitative analysis model between the near-infrared spectrum and the total water-soluble sugar content based on the total water-soluble sugar content and near-infrared spectrum of each qualified liquid sample; determining the total water-soluble sugar threshold corresponding to each qualified liquid brand based on the total water-soluble sugar content of each qualified liquid sample; measuring the near-infrared spectrum of the liquid sample to be tested, and determining the total water-soluble sugar content of the liquid sample to be tested based on the near-infrared spectrum of the liquid sample to be tested and the near-infrared quantitative analysis model; and comparing the total water-soluble sugar content of the liquid sample to be tested with the total water-soluble sugar threshold corresponding to a qualified liquid of the same brand to determine the stability of the preparation quality of the liquid to be tested. This method can quickly and easily evaluate the stability of the preparation quality of the liquid.

Description

Technical Field

[0001] The invention relates to the application field of near-infrared spectral analysis technology, and in particular to a method for rapidly analyzing the quality stability of tobacco liquid preparation. Background Art

[0002] Tobacco liquid can regulate the pH of smoke, improve the flavor and comfort of cigarettes, enhance the aroma of cigarettes, and mask and remove unpleasant odors and irritation from the tobacco leaves. Its quality stability directly impacts the quality of cigarette products. Water-soluble sugars are the most important component of tobacco liquid. Therefore, to achieve stable tobacco liquid quality, it is crucial to ensure a stable water-soluble sugar content during the preparation process. Accurately measuring the water-soluble sugar content in tobacco liquid samples is crucial for evaluating liquid quality and guiding accurate tobacco addition.

[0003] In the current existing technology, the sugar content in the feed liquid is generally measured by chemical analysis method, which is a cumbersome and time-consuming measurement process. Summary of the Invention

[0004] The main purpose of the present invention is to solve the problem in the prior art that the measurement process of the water-soluble sugar content in the feed liquid is cumbersome and time-consuming.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for rapidly analyzing the quality stability of a tobacco liquid preparation, which can rapidly and efficiently measure and evaluate the water-soluble sugar content in the liquid. The method comprises:

[0006] Collect near-infrared spectra of multiple qualified liquid samples of different brands, and determine the total water-soluble sugar content in each qualified liquid sample;

[0007] According to the water-soluble total sugar content and near-infrared spectrum of each qualified liquid sample, a near-infrared quantitative analysis model between the near-infrared spectrum and the water-soluble total sugar content was constructed;

[0008] According to the total water-soluble sugar content of each qualified liquid sample, the total water-soluble sugar threshold corresponding to each brand of qualified liquid is determined respectively;

[0009] Collecting a near-infrared spectrum of the liquid sample to be tested, and determining the total water-soluble sugar content of the liquid sample to be tested based on the near-infrared spectrum of the liquid sample to be tested and a near-infrared quantitative analysis model;

[0010] The total water-soluble sugar content of the liquid sample to be tested is compared with the total water-soluble sugar threshold corresponding to the qualified liquid of the same brand to determine the stability of the preparation quality of the liquid to be tested.

[0011] Optionally, based on the total water-soluble sugar content and near-infrared spectrum of each qualified liquid sample, constructing a near-infrared quantitative analysis model between the near-infrared spectrum and the total water-soluble sugar content includes:

[0012] Preprocessing the near infrared spectra of each qualified liquid sample collected, and selecting the band representing the sugar content in the preprocessed near infrared spectra;

[0013] According to the total water-soluble sugar content of each qualified liquid sample and the band characterizing the sugar content, a near-infrared quantitative analysis model was constructed using the partial least squares method.

[0014] Optionally, the preprocessing includes at least one of multivariate scatter correction processing, first-order derivative processing, and second-order derivative processing.

[0015] Optionally, the wavelength range for characterizing sugar content is 5500-7500 cm -1 and 4100~4600cm -1 near-infrared spectral range.

[0016] Alternatively, the total water-soluble sugar content of the liquid sample is determined using a continuous flow analysis method.

[0017] Optionally, a near infrared spectrometer is used to collect the near infrared spectra of each liquid sample. The wavelength scanning range of the near infrared spectrometer is 4000-10000 cm -1 , with a resolution of 8cm -1 , the number of scans is 64 times.

[0018] Optionally, determining the water-soluble total sugar threshold corresponding to each brand of qualified liquid sample based on the water-soluble total sugar content of each qualified liquid sample includes:

[0019] Classify the total water-soluble sugar content of all qualified liquid samples collected according to the brand;

[0020] According to the total water-soluble sugar content of each qualified liquid sample of the same brand, calculate the average value and standard deviation of the total sugar content corresponding to the brand of liquid;

[0021] The water-soluble total sugar threshold corresponding to each brand of feed liquid is determined based on the average value and standard deviation of the total sugar content corresponding to each brand of qualified feed liquid samples.

[0022] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0023] The method provided in the embodiment of the present invention for rapidly analyzing the quality stability of liquid preparations is characterized by being rapid, efficient, and simple by collecting finished tobacco liquid preparations of different brands and batches, calculating the standard content of total water-soluble sugars of different brands, and then evaluating the quality stability of the liquid preparations based on the fluctuation range of the sugar content of the sample liquids to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of the method for rapidly analyzing the quality stability of liquid preparation provided by the present invention;

[0025] Figure 2 It is the original near infrared spectra of different brands of liquid provided by the present invention;

[0026] Figure 3 This is the near infrared spectra of different brands of liquid after pretreatment provided by the present invention;

[0027] Figure 4 It is the predicted result of the total water-soluble sugar of the A-grade liquid sample to be tested provided by the present invention;

[0028] Figure 5 It is the predicted result of the total water-soluble sugar of the B-brand liquid sample to be tested provided by the present invention;

[0029] Figure 6 It is the predicted result of the total water-soluble sugar of the C-grade liquid sample to be tested provided by the present invention;

[0030] Figure 7 This is the predicted result of the total water-soluble sugar of the D-brand liquid sample to be tested provided by the present invention. DETAILED DESCRIPTION

[0031] The following is an explanation of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0032] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0033] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0034] like Figure 1 As shown, an embodiment of the present invention provides a method for rapidly analyzing the quality stability of a tobacco liquid preparation. Specifically, the method can be applied to analyzing and detecting the quality stability of a tobacco liquid preparation. The rapid analysis of the quality stability of a tobacco liquid preparation may include:

[0035] Step S1: collecting the water-soluble total sugar content and near-infrared spectra of a plurality of qualified liquid samples of different brands.

[0036] Specifically, qualified tobacco liquid samples of different brands and batches were collected as modeling samples, wherein qualified liquid samples refer to samples that have passed the physical and chemical indicators of relative density and refractive index. In one embodiment of the present invention, a total of 87 samples were selected as modeling samples.

[0037] Furthermore, the total water-soluble sugar content of the modeling sample can be determined using a continuous flow analysis method in accordance with the industry standard YC / T159-2002 "Determination of water-soluble sugars in tobacco and tobacco products - continuous flow analysis method".

[0038] Furthermore, a near-infrared spectrometer can be used to collect near-infrared spectra of modeling samples. Specifically, the relative humidity of the laboratory is controlled between 20% and 80%, and the temperature is controlled between 18°C and 26°C. The near-infrared spectrometer should be preheated for at least 1 hour, and then calibrated with the self-test program of the instrument before use. Take an appropriate amount of liquid sample and put it into a cuvette to collect the near-infrared transmission spectrum of the liquid sample. Specifically, the wavelength scanning range of the near-infrared spectrometer is 4000 to 10000 cm -1 , with a resolution of 8cm -1 The number of scans was 64. The software used in the instrument was the instrument's own RESULT-Integration workflow design software, RESULT-Operation software, and TQ Analyst spectral analysis software.

[0039] Step S2: constructing a near-infrared quantitative analysis model between the near-infrared spectrum and the water-soluble total sugar content based on the water-soluble total sugar content and the near-infrared spectrum of each qualified liquid sample.

[0040] Furthermore, to improve the accuracy of the near-infrared quantitative analysis model, before establishing the near-infrared quantitative analysis model, the method may further include: preprocessing the near-infrared spectrum of the liquid sample after collecting the near-infrared spectrum. The preprocessing process may include at least one of multivariate scattering correction processing, first-order derivative processing, and second-order derivative processing.

[0041] For example, smoothing and baseline correction of the spectrum can effectively reduce baseline drift and noise interference in the near-infrared spectrum, thereby facilitating the full extraction of effective characteristic information contained in the spectrum and improving the accuracy and predictive ability of the near-infrared quantitative analysis model. Figure 2 It can be seen from the near-infrared spectra of different brands that the OH groups in the liquid are large, which causes the wavelength to be 4800-5400 cm -1 The absorption peak in the range of 5500-7500 cm is saturated, so the data in this band cannot be used to establish a quantitative model. -1 and 4100~4600cm -1 There are significant spectral differences during this period, so the spectra of these two wavenumber bands can be used to characterize the changes in sugar content and then used to establish a near-infrared quantitative analysis model.

[0042] In addition, due to the complex and non-uniform composition of the prepared liquid, the NIR spectrum baseline will inevitably drift. Therefore, the original spectrum needs to be preprocessed during the model construction process. Here, the spectrum preprocessing method of multivariate scattering correction and first-order derivative is used. The results after spectrum processing are as follows Figure 3 shown.

[0043] In specific implementation, the effectiveness of the established near-infrared quantitative analysis model can be evaluated using three indicators: the root mean square error of calibration (RMSEC), the root mean square error of prediction (RMSEP), and the relative prediction deviation (RPD). RPD, the ratio of the standard deviation of the modeled data distribution to the root mean square error of prediction, comprehensively considers the standard deviation of the predicted sample chemical value and the standard deviation of the prediction of the established model, and is an important parameter for evaluating the model's resolution. Generally speaking, if RPD>3.0, it means that the calibration effect is good and the established model can be used for the detection of actual samples; if 2.5≤RPD≤3.0, it means that the established model can perform quantitative analysis, but the accuracy needs to be improved; if RPD<2.5, it means that quantitative analysis of the component is difficult.

[0044] Specifically, taking 87 qualified liquid samples as modeling samples, the establishment and verification process of the near-infrared quantitative analysis model is described, which can include the following steps:

[0045] 87 qualified liquid samples were collected as modeling samples and randomly divided into 75 calibration samples and 12 validation samples according to brand. A near-infrared quantitative analysis model for total water-soluble sugars in tobacco liquids was established using the partial least squares (PLS) method based on the near-infrared spectra and total water-soluble sugar content of each sample. The optimal number of factors for the calibration model established using the 75 calibration samples was 6, with a root mean square error (RMSEC) of 0.274 and a correlation coefficient of 0.9989 for the calibration set. The root mean square error of prediction (RMSEP) of 0.315 and a correlation coefficient of 0.9989 for the validation set was 18.769, indicating that the model is well suited for the determination of total water-soluble sugars in the liquid samples under test. Furthermore, the RMSEP / RMSEC values, a parameter evaluating model robustness, were all less than 1.2, indicating that the global model is robust to the test samples.

[0046] Step S3: Determine the total water-soluble sugar threshold corresponding to each brand of qualified liquid according to the total water-soluble sugar content of each qualified liquid sample.

[0047] Specifically, step S3 may include:

[0048] Step S31: Classify the total water-soluble sugar content of all collected qualified liquid samples according to the brand;

[0049] Step S32: Calculate the average and standard deviation of the total sugar content of the same grade of liquid according to the total water-soluble sugar content of each qualified liquid sample;

[0050] Step S33: Determine the water-soluble total sugar threshold corresponding to each brand of feed liquid based on the average value and standard deviation of the total sugar content corresponding to each brand of qualified feed liquid samples.

[0051] Qualified liquid samples of the same brand were grouped together. The average and standard deviation of the total water-soluble sugars (TSS) content of all qualified samples of the same brand were calculated. This led to the establishment of a TSS threshold corresponding to the TSS content of that qualified brand. Specifically, the TSS threshold = TSS average ± 3 × standard deviation. The same procedure was repeated for qualified samples of each brand until the TSS threshold corresponding to all qualified brands was determined.

[0052] Furthermore, a total sugar content database can be constructed based on the water-soluble total sugar thresholds corresponding to each brand of qualified feed liquid obtained above, in which each feed liquid brand and the water-soluble total sugar threshold corresponding to each feed liquid brand can be included.

[0053] Step S4: measuring the near infrared spectrum of the liquid sample to be tested, and determining the total water-soluble sugar content of the liquid sample to be tested based on the near infrared spectrum of the liquid sample to be tested and the near infrared quantitative analysis model.

[0054] Specifically, the same method as the method for collecting the near infrared spectrum of the modeling liquid sample can be used to collect the near infrared spectrum of the liquid sample to be tested, and the near infrared spectrum of the liquid sample to be tested is selected in the band of 5500-7500 cm -1 and 4100~4600cm -1 The spectral band of the near-infrared spectrum band is substituted into the previously established near-infrared quantitative analysis model to calculate the total water-soluble sugar content of the liquid sample to be tested.

[0055] Step S5: comparing the total water-soluble sugar content of the liquid sample to be tested with the total water-soluble sugar threshold corresponding to the qualified liquid of the same brand to determine the stability of the preparation quality of the liquid to be tested.

[0056] Specifically, the brand of the liquid to be tested is first determined, and then the total water-soluble sugar content of the liquid to be tested is compared with the total water-soluble sugar threshold corresponding to the same brand of liquid to determine the stability of the preparation quality of the liquid to be tested. As mentioned above, the total water-soluble sugar threshold corresponding to each brand of liquid can fluctuate within the range of (average water-soluble sugar content - 3 × standard deviation) to (average water-soluble sugar content + 3 × standard deviation). Therefore, if the total water-soluble sugar content of the liquid sample to be tested is within this range, then it means that the liquid to be tested is qualified. Otherwise, the quality of the liquid to be tested is unstable and it is unqualified.

[0057] The method provided by the present invention for rapidly analyzing the quality stability of liquid preparations is to collect a certain number of finished tobacco liquid preparations of different brands and batches, determine the content of total water-soluble sugars in the samples according to tobacco industry standards using a continuous flow method, and measure the near-infrared spectrum of the samples using a transmission method of near-infrared spectroscopy to establish a near-infrared quantitative analysis model for total water-soluble sugars. Furthermore, the standard content of total water-soluble sugars of different brands is calculated, that is, a quality fluctuation range is provided. The quality stability of the liquid preparation can then be evaluated based on the fluctuation range of the sugar content of the sample liquid to be tested. Furthermore, since the total sugar content of different brands of liquid is different, the type of the liquid to be tested (i.e., the brand of the liquid to be tested) can also be identified based on the calculated total sugar content of the liquid sample to be tested. This method is rapid, efficient, and simple.

[0058] Example

[0059] Using this method, a near-infrared quantitative analysis model was established, and the corresponding water-soluble total sugar thresholds for each grade of qualified liquid were determined. Table 1 shows the total sugar content thresholds and actual measured values for four different grades of qualified samples (A, B, C, and D) obtained using this method. As can be seen from the table, the mean and standard deviation of the total sugar content obtained using the method provided by the present invention are relatively close to the mean and standard deviation of the actual measured total sugar content, demonstrating the effectiveness of the method provided by the present invention.

[0060] Table 1

[0061]

[0062] A total of 107 representative liquid preparation samples of different brands and batches in normal production were collected (the number of samples of brands A, B, C, and D were 33, 31, 22, and 21 respectively). The relative humidity in the laboratory was controlled between 20% and 80%, and the temperature was controlled between 18°C and 26°C. The near-infrared spectrometer was preheated for at least 1 hour, and then calibrated with the self-test program of the instrument before use. An appropriate amount of liquid sample was placed in a cuvette, and the near-infrared transmission spectrum of the liquid sample was collected. 5500-7500cm -1 and 4100~4600cm -1 The spectrum of the wavelength range is substituted into the established near-infrared quantitative analysis model to calculate the total water-soluble sugar content. Specifically, the wavelength scanning range of the near-infrared spectrometer is 4000-10000 cm -1 , with a resolution of 8cm -1 The number of scans was 64. The software used in the instrument was the instrument's own RESULT-Integration workflow design software, RESULT-Operation software, and TQ Analyst spectral analysis software.

[0063] The established near infrared quantitative analysis model is used to predict the total water-soluble sugar content of the liquid sample to be tested (such as Figures 4 to 7The predicted value was calculated and observed to determine if it was within the quality control range. The median value of the total water-soluble sugar content of the qualified liquid samples was used as the median, and the control limits for qualified samples were defined as the mean ± 3 × standard deviation. For Brand A, the total sugar contents of samples from batches 8 and 13 were 9.51% and 20.22%, respectively, significantly lower than the average total sugar content of 22.37% for qualified samples of this brand. Therefore, these two batches of samples were considered unqualified. To verify the accuracy of the results, the relative density of the samples from this batch was tested. The average relative density of qualified samples was 1.134, but the relative densities of samples from batches 8 and 13 were 1.054 and 1.120, respectively, significantly different from those of qualified samples. These experimental results further demonstrate the accuracy and rapidity of this method. Of the tested liquid samples from brands B and C, two and one failed the test, respectively. The prepared liquid samples from brand D showed good stability, with the total sugar content fluctuating within the quality control range.

[0064] The method for rapidly analyzing the quality stability of liquid preparation provided by the present invention can rapidly detect the total water-soluble sugar content of the liquid preparation product and, by monitoring the total sugar content, determine whether the sample is qualified. Furthermore, this method can also be used to monitor changes in the total water-soluble sugar content during the online preparation of the liquid to determine whether the preparation and stirring time has been met. Furthermore, this method can also identify the type of the liquid to be tested based on the calculated total sugar content of the liquid sample to be tested.

[0065] Although the present invention has been illustrated and described with reference to its embodiments, it should be understood by those skilled in the art that the above description is provided as a further detailed description of the present invention in conjunction with specific embodiments, and that the specific implementation of the present invention is not limited to these descriptions. Those skilled in the art may make various changes in form and details, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A method for rapidly analyzing the quality stability of a tobacco liquid preparation, characterized in that: include: Collecting near-infrared spectra of a plurality of qualified liquid samples of different brands, and determining the total water-soluble sugar content in each of the qualified liquid samples; Constructing a near-infrared quantitative analysis model between the near-infrared spectrum and the water-soluble total sugar content according to the water-soluble total sugar content and the near-infrared spectrum of each qualified liquid sample; Determine the water-soluble total sugar threshold corresponding to each brand of qualified liquid according to the water-soluble total sugar content of each qualified liquid sample; Collecting a near-infrared spectrum of the liquid sample to be tested, and determining the total water-soluble sugar content of the liquid sample to be tested based on the near-infrared spectrum of the liquid sample to be tested and the near-infrared quantitative analysis model; Comparing the total water-soluble sugar content of the test liquid sample with the total water-soluble sugar threshold corresponding to the qualified liquid of the same brand to determine the stability of the preparation quality of the test liquid; Wherein, determining the water-soluble total sugar threshold corresponding to each brand of qualified liquid according to the water-soluble total sugar content of each qualified liquid sample includes: Classify the total water-soluble sugar content of all qualified liquid samples collected according to the brand; According to the total water-soluble sugar content of each qualified liquid sample of the same brand, calculate the average value and standard deviation of the total sugar content corresponding to the brand of liquid; The water-soluble total sugar threshold corresponding to each brand of feed liquid is determined based on the average value and standard deviation of the total sugar content corresponding to each brand of qualified feed liquid samples.

2. The method according to claim 1, wherein The step of constructing a near infrared quantitative analysis model between the near infrared spectrum and the water-soluble total sugar content based on the water-soluble total sugar content and the near infrared spectrum of each qualified liquid sample comprises: Preprocessing the near infrared spectrum of each of the collected qualified liquid samples, and selecting a band representing the sugar content in the preprocessed near infrared spectrum; The near-infrared quantitative analysis model is constructed using the partial least squares method based on the total water-soluble sugar content of each qualified liquid sample and the wavelength band characterizing the sugar content.

3. The method according to claim 2, wherein The preprocessing includes at least one of multivariate scatter correction processing, first-order derivative processing, and second-order derivative processing.

4. The method according to claim 2, wherein The wavelength band for characterizing sugar content is 5500-7500 cm -1 and 4100~4600cm -1 near-infrared spectral range.

5. The method according to claim 1, wherein The total water-soluble sugar content of the liquid samples was determined using continuous flow analysis.

6. The method according to claim 1, wherein The near infrared spectra of each liquid sample were collected using a near infrared spectrometer with a wavelength scanning range of 4000 to 10000 cm -1 , with a resolution of 8cm -1 , the number of scans is 64 times.

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