Method for predicting the equilibrium water activity and the equilibrium moisture content of cut tobacco after cigarette packaging

Abstract

The application discloses a method for predicting the equilibrium water activity and the equilibrium moisture content of cut tobacco after cigarette packaging. The cigarette raw material sample and the auxiliary material sample before packaging are dried in an oven, and the dry basis mass of each sample is measured; the original water activity of each sample before packaging is tested; the water activity and the moisture content of each sample under certain temperature and different humidity conditions are tested, and the isothermal moisture absorption curve of each sample is fitted; according to the principle that the total moisture content of each sample before and after packaging is unchanged and the principle that the water activity of each sample is consistent when the mixed system after packaging reaches the equilibrium state, a cigarette packaging moisture migration prediction model is established, the equilibrium water activity of cut tobacco after cigarette packaging is predicted, and according to the fitted isothermal moisture absorption curve of cut tobacco, the equilibrium moisture content of cut tobacco after cigarette packaging is predicted. The application can predict the equilibrium moisture content of cut tobacco after cigarette packaging before packaging, and can clearly determine the moisture migration change rule between cut tobacco and auxiliary materials after packaging.

Description

Technical Field

[0001] This invention belongs to the field of tobacco and cigarette packaging technology, and specifically relates to a method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging. Background Technology

[0002] The moisture content and water activity of tobacco are important factors affecting the smoking quality, style, and comfort of cigarettes. Generally, when the moisture content of the tobacco in a cigarette is low, the burning speed is faster, the amount of smoke per puff is larger, the flavor is strong but not mellow, the irritation and dryness are enhanced, and the comfort is poor. On the other hand, when the moisture content of the tobacco in a cigarette is high, the burning speed is slower, the amount of smoke per puff is smaller, the flavor is bland and dull, the aroma is not prominent, and the aftertaste is lingering on the tongue. Moreover, if the moisture content of the tobacco in a cigarette is too high, it is also more prone to mold growth during storage.

[0003] Studies have shown that the difference in water activity between cigarette raw materials and auxiliary materials is the driving force behind moisture migration in cigarettes. Compared to the water activity of tobacco, the water activity of various auxiliary materials is relatively low. Therefore, the difference in water activity leads to moisture migration between tobacco and auxiliary materials, thus affecting the sensory stability of cigarette products. Given the importance of tobacco moisture, cigarette product design requires, on the one hand, selecting appropriate cigarette raw materials and auxiliary materials to meet the required moisture content of tobacco in cigarette products; and on the other hand, minimizing moisture migration from tobacco in cigarette products to maintain long-term quality stability.

[0004] Currently, the methods for testing the water activity and moisture content of tobacco in packaged cigarettes are all conducted after opening the package. However, this method has a time lag. A large amount of material is input into the production line during the rolling process. Even if adjustments are made immediately after the test results are known, it will still result in a large waste of tobacco and auxiliary materials.

[0005] Therefore, establishing a method to predict the water activity and moisture content of tobacco in packaged cigarettes, so that the moisture content of tobacco in packaged cigarettes can be obtained before packaging, is of great significance and value for the moisture design of cigarette products, the selection of cigarette raw materials and auxiliary materials, and the maintenance of stable cigarette product quality. Summary of the Invention

[0006] In view of the above-mentioned deficiencies of the prior art, the present invention provides a method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging, so as to predict the equilibrium moisture content of tobacco shreds after cigarette packaging before packaging and clarify the moisture migration and change law between tobacco shreds and auxiliary materials after packaging.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] A method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging includes the following steps:

[0009] S1. Select cigarette raw material samples and auxiliary material samples before packaging. The cigarette raw material samples include tobacco shreds. Place the selected cigarette raw material samples and auxiliary material samples in an oven to dry. After cooling, measure the dry basis mass of each sample.

[0010] S2. Test the original water activity of each sample under certain temperature and humidity conditions before packaging;

[0011] S3. Test the water activity and moisture content of each sample under certain temperature and humidity conditions, and plot the isothermal moisture absorption curve of each sample. Then, use the model to fit the isothermal moisture absorption curve of each sample to obtain the relationship between water activity and moisture content of each sample at a specific temperature.

[0012] S4. Based on the principle that the total moisture content of each sample remains unchanged before and after packaging and the principle that the water activity of each sample is consistent when the mixed system reaches equilibrium after packaging, a prediction model for moisture migration in cigarette packaging is established. The water activity of the mixed system reaches equilibrium after cigarette packaging is calculated, and the equilibrium water activity of the tobacco shreds after cigarette packaging is predicted. Based on the fitted isothermal hygroscopic curve of the tobacco shreds, the equilibrium moisture content of the tobacco shreds after cigarette packaging is predicted.

[0013] Further, step S2 specifically involves testing the original water activity of each sample under certain temperature and humidity conditions before packaging using a water activity meter. Specifically, take 0.5-1.0g of the corresponding sample and place it in a sample cup, then cover the sample cup with the lid. Open the test chamber of the water activity meter and open the sample cup lid. Quickly place the sample cup into the test chamber and close the test chamber. After the reading of the water activity meter stabilizes, record the original water activity of the corresponding sample. In this way, complete the original water activity test of all samples.

[0014] Further, in step S3: the water activity and moisture content of each sample are tested under certain temperature and humidity conditions. Specifically, the water activity of each sample is tested using a water activity meter under certain temperature and humidity conditions, and the moisture content of each sample is tested using an oven method under certain temperature and humidity conditions, wherein the moisture content is the dry basis moisture content.

[0015] Further, in step S3: the water activity and moisture content of each sample are tested under certain temperature and humidity conditions. Specifically, the corresponding samples are placed in a constant temperature and humidity chamber, the temperature is set to 22℃, and the humidity is set to 20%, 35%, 50%, 65%, and 80%, respectively. The samples are then equilibrated for more than 48 hours under the corresponding humidity conditions. The water activity of the corresponding samples under each humidity condition is tested using a water activity meter. In this way, the water activity test of all samples under certain temperature and humidity conditions is completed. The moisture content of the corresponding samples under each humidity condition is tested using an oven drying method. In this way, the moisture content test of all samples under certain temperature and humidity conditions is completed.

[0016] Further, in step S3: the moisture content of each sample under certain temperature and humidity conditions is tested using the oven drying method. Specifically, the corresponding samples placed on numbered sample trays under certain temperature and humidity conditions are weighed and recorded as m. 湿+盘 After the corresponding samples reach equilibrium under various humidity levels, the corresponding sample trays are placed in an oven to dry, then covered and removed, and placed in a desiccator to cool to room temperature. The trays are then immediately weighed and recorded as m. 干+盘 Then, the moisture content x of the corresponding sample under certain temperature and humidity conditions is calculated according to formula (1). In this way, the moisture content test of all samples under certain temperature and different humidity conditions is completed.

[0017]

[0018] In equation (1), m 盘 This indicates the quality of the sample tray.

[0019] Furthermore,

[0020] In step S1: the drying temperature in the oven is controlled at 100±1℃, and the drying time is controlled at 2-3 hours. The dry weight of the corresponding sample is recorded as m. 干 ;

[0021] In step S3: When testing the moisture content of each sample under certain temperature and humidity conditions using the oven drying method, the drying temperature in the oven is controlled at 100±1℃, and the drying time is controlled at 2-3h.

[0022] Further, in step S3: the isothermal moisture absorption curves of each sample are fitted using a model, specifically by fitting the isothermal moisture absorption curves of each sample using the GAB equation, and obtaining the GAB equation for the isothermal moisture absorption curves:

[0023]

[0024] In equation (2), x represents the moisture content, and α w Let w represent water activity, k represent water content in the monolayer, k represent a constant related to water binding sites, and c represent a constant related to heat of adsorption. The w, k, and c in the GAB equation for the isothermal hygroscopic curve of each sample are different.

[0025] Furthermore, in step S4: the prediction model for moisture migration in cigarette packaging is expressed using formula (3).

[0026] m 1干 ·x(α w1 )+m 2干 ·x(αw2 )+…..+m n干 ·x(α wn )=m 1干 ·x1(α w )+m 2干 ·x2(α w )+…..+m n干 ·x n (α w ) (3)

[0028] In equation (3), m 1干 m represents the dry weight of sample 1. 2干 This represents the dry weight of sample number 2, m. n干 α represents the dry weight of sample n. w1 This represents the original water activity of sample 1 before it was dried and packaged, x(α). w1 α represents the original moisture content of sample 1 before packaging, calculated based on the isothermal moisture absorption curve of sample 1 fitted in step S3. w2 This represents the original water activity of sample No. 2 before it was dried and packaged, x(α) w2 α represents the original moisture content of sample 2 before packaging, calculated based on the isothermal moisture absorption curve of sample 2 fitted in step S3. wn This represents the original water activity of sample n before packaging, excluding drying. x(α) wn α represents the original moisture content of sample n before packaging, calculated based on the isothermal moisture absorption curve of sample n fitted in step S3. w Indicates the water activity of the mixed system when it reaches equilibrium after packaging, x1(α) w () represents the moisture content of sample 1 when the mixed system reaches equilibrium after packaging, x2(α) w () indicates the moisture content of sample 2 when the mixed system reaches equilibrium after packaging. n (α w The value represents the moisture content of sample n when the mixed system reaches equilibrium after packaging.

[0029] Furthermore, in step S1: the auxiliary material samples include filter rods and small box label paper.

[0030] Furthermore,

[0031] In step S2: the original water activity range of the tobacco shreds under certain temperature and humidity conditions before packaging is 0.5-0.7, and the original water activity range of the filter rod and the small box label paper under certain temperature and humidity conditions before packaging is 0.2-0.9.

[0032] In step S4: the water activity range of the mixed system after cigarette packaging when it reaches equilibrium is 0.5-0.7;

[0033] In step S5: the equilibrium moisture content of the tobacco shreds after cigarette packaging is in the range of 8-15%.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to the present invention includes the following steps: S1, selecting cigarette raw material samples and auxiliary material samples before packaging, wherein the cigarette raw material samples include tobacco shreds, and placing the selected cigarette raw material samples and auxiliary material samples in an oven to dry, and measuring the dry basis mass of each sample; S2, testing the original water activity of each sample under certain temperature and humidity conditions before packaging; S3, testing the water activity and moisture content of each sample under certain temperature and different humidity conditions, plotting the isothermal hygroscopic curves of each sample, and fitting each sample with a model. The isothermal hygroscopic curves were obtained to determine the relationship between water activity and moisture content of each sample at a specific temperature. S4. Based on the principle that the total moisture content of each sample remains constant before and after packaging, and the principle that the water activity of each sample is consistent when the mixed system reaches equilibrium after packaging, a cigarette packaging moisture migration prediction model was established. This model calculates the water activity of the mixed system when it reaches equilibrium after cigarette packaging and predicts the equilibrium water activity of the tobacco shreds after packaging. S5. Based on the predicted equilibrium water activity of the tobacco shreds after packaging and the fitted isothermal hygroscopic curves of the tobacco shreds, the equilibrium moisture content of the tobacco shreds after packaging was predicted. This allows for the prediction of the equilibrium moisture content of tobacco shreds after packaging, even before the cigarettes are rolled. It clarifies the moisture migration and change patterns between packaged tobacco shreds and auxiliary materials, providing a theoretical basis and methodological support for reducing moisture migration between packaged tobacco shreds and auxiliary materials and improving the moisture stability of finished cigarettes. It also provides important technical guidance for the moisture design of cigarette raw materials and auxiliary materials.

[0036] In this invention, the prediction model for moisture migration in cigarette packaging is expressed using formula (3), m 1干 ·x(α w1 )+m 2干 ·x(α w2 )+…..+m n干 ·x(α wn )=m 1干 ·x1(α w )+m 2干 ·x2(α w )+…..+m n干 ·x n (α wThus, this invention does not re-establish the sample model after mixing. Instead, it directly establishes a formula for predicting moisture migration in cigarette packaging based on the principle that the total moisture content of each sample remains unchanged before and after moisture migration (i.e., before and after packaging) and the principle that the water activity of each sample is consistent when the mixed system reaches equilibrium after packaging. This formula only involves the dry basis mass of each sample and the isothermal hygroscopic curve of each sample. It does not require re-establishing the sample model of the mixed system to achieve prediction. Therefore, the method of this invention is simpler. Attached Figure Description

[0037] Figure 1 The isothermal moisture absorption curve of tobacco shreds A in cigarette A;

[0038] Figure 2 The isothermal moisture absorption curve of filter rod A in cigarette A;

[0039] Figure 3 The isothermal moisture absorption curve of the label paper A in the small box of cigarette A;

[0040] Figure 4 The isothermal moisture absorption curve of tobacco shreds B in cigarette B;

[0041] Figure 5 The isothermal moisture absorption curve of filter rod B in cigarette B;

[0042] Figure 6 The isothermal moisture absorption curve is shown for the label paper B of the small box in cigarette B. Detailed Implementation

[0043] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0044] A method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging includes the following steps:

[0045] S1. Select cigarette raw material samples and auxiliary material samples before packaging. The cigarette raw material samples include tobacco shreds, and the auxiliary material samples include filter rods and small box label paper. Place the selected cigarette raw material samples and auxiliary material samples in an oven to dry. After cooling, use a balance to measure the dry basis mass m of each sample. 干 The drying temperature in the oven is controlled at 100±1℃, and the drying time is controlled at 2-3 hours.

[0046] S2. Use a water activity meter to test the original water activity of each sample under certain temperature and humidity conditions before packaging. Specifically, take 0.5-1.0g of the corresponding sample and place it in the sample cup, and cover the sample cup with the lid. Open the test chamber of the water activity meter and open the lid of the sample cup. Quickly put the sample cup into the test chamber and close the test chamber. After the reading of the water activity meter stabilizes, record the original water activity of the corresponding sample. In this way, complete the original water activity test of all samples.

[0047] The original water activity range of the tobacco shreds under certain temperature and humidity conditions before packaging is 0.5-0.7, and the original water activity range of the filter rod and the small box label paper under the same conditions is 0.2-0.9.

[0048] S3. Test the water activity and moisture content of each sample under certain temperature and humidity conditions, and plot the isothermal moisture absorption curve of each sample. Then, use the model to fit the isothermal moisture absorption curve of each sample to obtain the relationship between water activity and moisture content of each sample at a specific temperature.

[0049] The test involved measuring the water activity and moisture content of each sample under different temperature and humidity conditions. Specifically, a water activity meter was used to measure the water activity of each sample under different temperature and humidity conditions, and an oven drying method was used to measure the moisture content of each sample under different temperature and humidity conditions. The moisture content was measured on a dry basis. More specifically, the corresponding samples were placed in a constant temperature and humidity chamber with the temperature set at 22°C and the humidity set at 20%, 35%, 50%, 65%, and 80%, respectively. The samples were then equilibrated for at least 48 hours under the corresponding humidity conditions. The water activity of the corresponding samples under each humidity condition was measured using a water activity meter. This process was repeated to complete the water activity test of all samples under different temperature and humidity conditions. The moisture content of the corresponding samples under each humidity condition was measured using an oven drying method. This process was repeated to complete the moisture content test of all samples under different temperature and humidity conditions.

[0050] The oven drying method was used to test the moisture content of each sample under certain temperature and humidity conditions. Specifically, the corresponding samples placed on numbered sample trays under certain temperature and humidity conditions were weighed and recorded as m. 湿+盘 After the corresponding samples reach equilibrium under various humidity levels, the corresponding sample trays are placed in an oven to dry, then covered and removed, and placed in a desiccator to cool to room temperature. The trays are then immediately weighed and recorded as m. 干+盘 Then, the moisture content x of the corresponding sample under certain temperature and humidity conditions is calculated according to formula (1). In this way, the moisture content test of all samples under certain temperature and different humidity conditions is completed.

[0051]

[0052] In equation (1), m盘 Indicates the mass of the sample tray;

[0053] When the oven method was used to test the moisture content of each sample under certain temperature and humidity conditions, the drying temperature in the oven was controlled at 100±1℃ and the drying time was controlled at 2-3h.

[0054] The isothermal moisture absorption curves of each sample were fitted using a model, specifically using the GAB equation, where the GAB equation is:

[0055]

[0056] In equation (2), x represents the moisture content, and α w denoted by water activity, w represents monolayer water content, k represents a constant related to water binding sites, and c represents a constant related to heat of adsorption. The w, k, and c in the GAB equation for the isothermal hygroscopic curve of each sample are different.

[0057] S4. Based on the principle that the total moisture content of each sample remains unchanged before and after packaging and the principle that the water activity of each sample is consistent when the mixed system reaches equilibrium after packaging, establish a prediction model for moisture migration in cigarette packaging, calculate the water activity of the mixed system when it reaches equilibrium after cigarette packaging, and predict the equilibrium water activity of tobacco after cigarette packaging.

[0058] The prediction model for moisture migration in cigarette packaging is expressed using formula (3).

[0059] m 1干 ·x(α w1 )+m 2干 ·x(α w2 )+…..+m n干 ·x(α wn )=m 1干 ·x1(α w )+m 2干 ·x2(α w )+…..+m n干 ·x n (α w (3)

[0060] In equation (3), m 1干 m represents the dry weight of sample 1. 2干 This represents the dry weight of sample number 2, m. n干 α represents the dry weight of sample n. w1 This represents the original water activity of sample 1 under certain temperature and humidity conditions before packaging, x(α) w1α represents the original moisture content of sample 1 under certain temperature and humidity conditions before packaging, calculated based on the isothermal moisture absorption curve of sample 1 fitted in step S3. w2 This represents the original water activity of sample 2 under certain temperature and humidity conditions before packaging, x(α) w2 α represents the original moisture content of sample 2 under certain temperature and humidity conditions before packaging, calculated based on the isothermal moisture absorption curve of sample 2 fitted in step S3. wn x(α) represents the original water activity of sample n under certain temperature and humidity conditions before packaging. wn α represents the original moisture content of sample n under certain temperature and humidity conditions before packaging, calculated based on the isothermal moisture absorption curve of sample n fitted in step S3. w Indicates the water activity of the mixed system when it reaches equilibrium after packaging, x1(α) w () represents the moisture content of sample 1 when the mixed system reaches equilibrium after packaging, x2(α) w () indicates the moisture content of sample 2 when the mixed system reaches equilibrium after packaging. n (α w () indicates the moisture content of sample n when the mixed system reaches equilibrium after packaging;

[0061] The water activity range of the cigarette packaging mixture system when it reaches equilibrium is 0.5-0.7.

[0062] S5. Based on the predicted equilibrium water activity of the tobacco shreds after cigarette packaging, and based on the fitted isothermal hygroscopic curve of the tobacco shreds, predict the equilibrium moisture content of the tobacco shreds after cigarette packaging. The equilibrium moisture content of the tobacco shreds after cigarette packaging ranges from 8% to 15%. In addition, based on the calculated water activity of the mixed system after packaging when it reaches equilibrium, and based on the fitted isothermal hygroscopic curves of the filter rod and the label paper of the small box, predict the equilibrium moisture content of the filter rod and the label paper of the small box after cigarette packaging. The equilibrium moisture content of both the filter rod and the label paper of the small box after cigarette packaging ranges from 3% to 10%.

[0063] The temperature and humidity chamber is a KBF240 model from BINDER, Germany; the balance is a METTLER-TOLEDO analytical balance from Switzerland with a sensitivity of 0.0001g; the water activity meter is a DecagonAqualab 4TE water activity meter from the USA; the drying oven is a Venticell drying oven from Germany; and the cigarettes are produced by Shanghai Cigarette Factory.

[0064] Example 1

[0065] S1. Separate the label paper, tobacco, and filter rod from the small box of the fully open cigarette A, and separate the label paper, tobacco, and filter rod from the small box of the side-opening cigarette B. Place the two separate small boxes of label paper, two portions of tobacco, and two filter rods in an oven. The small box of label paper is dried at 100℃ for 3 hours, and the tobacco and filter rod are dried at 100℃ for 2 hours. After cooling, the dry basis mass m of each sample is measured using an analytical balance. 干 See Table 1;

[0066] Table 1

[0067]

[0068] S2. Place small box label paper A and small box label paper B in a constant temperature and humidity chamber at 22℃ and 40% humidity for 48 hours to equilibrate. Place tobacco A, filter rod A, tobacco B and filter rod B in a constant temperature and humidity chamber at 22℃ and 60% humidity for 48 hours to equilibrate. After equilibration, use a water activity meter to test the original water activity of each sample before packaging, and use an oven drying method to test the moisture content of each sample before packaging. See Table 2.

[0069] Table 2

[0070]

[0071] S3. Place tobacco shreds A, tobacco shreds B, filter rods A and B, and small box label paper A and B into a constant temperature and humidity chamber, respectively, and equilibrate them under different humidity conditions at a temperature of 22℃. Test the water activity and moisture content of each sample under certain temperature and humidity conditions. Specifically, based on the fluctuation range of moisture content of each sample, the humidity range is set to 20%-80%, and five humidity test points of 20%, 35%, 50%, 65%, and 80% are selected. The equilibration time for each humidity test point is 48 hours. Test the mass and water activity value of each sample under each humidity condition. After one round of testing, the dry basis mass of each sample is obtained by oven drying, and the moisture content under each humidity condition is calculated. Finally, obtain the water activity and moisture content of each sample under certain temperature and humidity conditions, and plot the isothermal moisture absorption curves of each sample. The isothermal moisture absorption curve of tobacco shreds A is shown below. Figure 1 The isothermal moisture absorption curve of filter rod A is shown in the figure. Figure 2 The isothermal moisture absorption curve of the small box label paper A is shown below. Figure 3 The isothermal moisture absorption curve of tobacco shreds A is shown in the figure. Figure 4 The isothermal moisture absorption curve of filter rod A is shown in the figure. Figure 5 The isothermal moisture absorption curve of the small box label paper A is shown below. Figure 6 ;

[0072] The isothermal moisture absorption curves of each sample were fitted using the GAB equation, and the GAB equations for the isothermal moisture absorption curves of each sample were obtained, as shown in Table 3.

[0073] Table 3

[0074]

[0075]

[0076] In Table 3, R represents the correlation coefficient between water activity and water content;

[0077] S4. Place the balanced tobacco shreds A and filter rod A from step S2 into the balanced small box label paper A, and place the balanced tobacco shreds B and filter rod B from step S2 into the balanced small box label paper B. Place the small box label paper A and small box label paper B into an aluminum foil bag, vent and seal it, and simulate the migration of tobacco moisture to the small box label paper. Seal for 14 days to ensure complete moisture migration. Use a water activity meter to test the equilibrium water activity of the tobacco shreds after packaging, and use an oven drying method to test the equilibrium moisture content of the tobacco shreds after packaging. Based on the principle that the total moisture content of each sample before and after packaging remains unchanged and the principle that the water activity of each sample is consistent when the mixed system reaches equilibrium after packaging, predict the equilibrium water activity of the tobacco shreds after cigarette packaging. Based on the GAB equation of the isothermal hygroscopic curve of the tobacco shreds fitted in step S3, predict the equilibrium moisture content of the tobacco shreds after cigarette packaging, as shown in Table 4.

[0078] Table 4

[0079]

[0080] As shown in Table 4, in Example 1, the measured value of the equilibrium water activity of tobacco shreds A after packaging cigarette A deviated from the predicted value by 1.34%, which is relatively small. The measured value of the equilibrium moisture content of tobacco shreds A after packaging cigarette A deviated from the predicted value by 2.63%, which is also relatively small. The measured value of the equilibrium water activity of tobacco shreds B after packaging cigarette B deviated from the predicted value by 1.01%, which is also relatively small. The measured value of the equilibrium moisture content of tobacco shreds B after packaging cigarette B deviated from the predicted value by 3.15%, which is also relatively small. This indicates that the method of the present invention has high accuracy in predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging.

[0081] Example 2

[0082] Step 1: Take tobacco A, filter rod A, and small box label A from the production line and seal them in aluminum foil bags with sealing strips for testing. Take tobacco B, filter rod B, and small box label B from the production line and seal them in aluminum foil bags with sealing strips for testing. For each sample, take two parallel control samples. At the same time, take the packaged cigarettes A and B and seal them in aluminum foil bags with sealing strips for 14 days to ensure complete moisture migration.

[0083] Step 2: Use a water activity meter to test the water activity values ​​of tobacco A, filter rod A, small box label A, tobacco B, filter rod B, and small box label B before packaging. Use an oven drying method to test the moisture content of tobacco A, filter rod A, small box label A, tobacco B, filter rod B, and small box label B before packaging. See Table 5.

[0084] Table 5

[0085]

[0086] Step 3: Based on the established formula for predicting moisture migration in cigarette packaging, predict the equilibrium water activity of the tobacco shreds after packaging, and based on the fitted GAB equation of the isothermal hygroscopic curve of the tobacco shreds, predict the equilibrium moisture content of the tobacco shreds after packaging; take cigarettes A and B that have been packaged in boxes and sealed in aluminum foil bags for 14 days, test the water activity and moisture content of the tobacco shreds, and compare them with the prediction results, as shown in Table 6.

[0087] Table 6

[0088]

[0089] As shown in Table 6, in Example 2, the measured value of the equilibrium water activity of tobacco shreds A after packaging cigarette A deviated from the predicted value by 0.69%, which is very small. The measured value of the equilibrium moisture content of tobacco shreds A after packaging cigarette A deviated from the predicted value by 0.41%, which is also very small. The measured value of the equilibrium water activity of tobacco shreds B after packaging cigarette B deviated from the predicted value by 0.74%, which is relatively small. The measured value of the equilibrium moisture content of tobacco shreds B after packaging cigarette B deviated from the predicted value by 1.60%, which is also relatively small. This indicates that the method of the present invention has high accuracy in predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging.

[0090] In summary, this invention can predict the equilibrium moisture content of tobacco shreds after cigarette packaging without rolling the cigarettes, clarify the moisture migration and change law between tobacco shreds and auxiliary materials after packaging, provide a theoretical basis and methodological support for reducing moisture migration between tobacco shreds and auxiliary materials after packaging and improving the moisture stability of finished cigarettes, and provide important technical guidance for the moisture design of cigarette raw materials and auxiliary materials.

[0091] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging, characterized in that, Includes the following steps: S1. Select cigarette raw material samples and auxiliary material samples before packaging. The cigarette raw material samples include tobacco shreds. Place the selected cigarette raw material samples and auxiliary material samples in an oven to dry. After cooling, measure the dry basis mass of each sample. S2. Test the original water activity of each sample under certain temperature and humidity conditions before packaging; S3. Test the water activity and moisture content of each sample under certain temperature and humidity conditions, and plot the isothermal moisture absorption curve of each sample. Then, use the model to fit the isothermal moisture absorption curve of each sample to obtain the relationship between water activity and moisture content of each sample at a specific temperature. S4. Based on the principle that the total moisture content of each sample remains unchanged before and after packaging and the principle that the water activity of each sample is consistent when the mixed system reaches equilibrium after packaging, a prediction model for moisture migration in cigarette packaging is established. The water activity of the mixed system reaches equilibrium after cigarette packaging is calculated, and the equilibrium water activity of the tobacco shreds after cigarette packaging is predicted. Based on the fitted isothermal hygroscopic curve of the tobacco shreds, the equilibrium moisture content of the tobacco shreds after cigarette packaging is predicted. In step S3: The isothermal moisture absorption curves of each sample are fitted using a model. Specifically, the isothermal moisture absorption curves of each sample are fitted using the GAB equation, and the GAB equation for the isothermal moisture absorption curves is obtained: （2） In equation (2), x represents the moisture content, and α w denoted by , w represents water activity, k represents water content in the monolayer, k represents a constant related to water binding sites, and c represents a constant related to heat of adsorption. The w, k, and c in the GAB equation for the isothermal hygroscopic curve of each sample are different. In step S4: the prediction model for moisture migration in cigarette packaging is expressed using formula (3). m 1干 ·x(a w1 )+m 2干 ·x(a w2 )+…..+m n干 ·x(a wn )=m 1干 ·x1(a w )+m 2干 ·x2(a w )+…..+m n干 ·x n (a w )(3) In equation (3), m 1干 m represents the dry weight of sample 1. 2干 This represents the dry weight of sample number 2, m. n干 α represents the dry weight of sample n. w1 This represents the original water activity of sample 1 before it was dried and packaged, x(α). w1 α represents the original moisture content of sample 1 before packaging, calculated based on the isothermal moisture absorption curve of sample 1 fitted in step S3. w2 This represents the original water activity of sample No. 2 before it was dried and packaged, x(α) w2 α represents the original moisture content of sample 2 before packaging, calculated based on the isothermal moisture absorption curve of sample 2 fitted in step S3. wn This represents the original water activity of sample n before packaging, excluding drying. x(α) wn α represents the original moisture content of sample n before packaging, calculated based on the isothermal moisture absorption curve of sample n fitted in step S3. w Indicates the water activity of the mixed system when it reaches equilibrium after packaging, x1(α) w () represents the moisture content of sample 1 when the mixed system reaches equilibrium after packaging, x2(α) w () indicates the moisture content of sample 2 when the mixed system reaches equilibrium after packaging. n (α w The value represents the moisture content of sample n when the mixed system reaches equilibrium after packaging.

2. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 1, characterized in that, Step S2 is as follows: Use a water activity meter to test the original water activity of each sample under certain temperature and humidity conditions before packaging. Specifically, take 0.5-1.0g of the corresponding sample and place it in the sample cup, and cover the sample cup with the lid. Open the test chamber of the water activity meter and open the lid of the sample cup. Quickly put the sample cup into the test chamber and close the test chamber. After the reading of the water activity meter stabilizes, record the original water activity of the corresponding sample. In this way, complete the original water activity test of all samples.

3. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 1, characterized in that, In step S3: the water activity and moisture content of each sample are tested under certain temperature and humidity conditions. Specifically, the water activity of each sample is tested using a water activity meter under certain temperature and humidity conditions, and the moisture content of each sample is tested using an oven method under certain temperature and humidity conditions, wherein the moisture content is the dry basis moisture content.

4. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 3, characterized in that, In step S3: the water activity and moisture content of each sample are tested under different temperature and humidity conditions. Specifically, the corresponding samples are placed in a constant temperature and humidity chamber, the temperature is set to 22℃, and the humidity is set to 20%, 35%, 50%, 65%, and 80%, respectively. The samples are then equilibrated for more than 48 hours under the corresponding humidity conditions. The water activity of the corresponding samples under each humidity condition is tested using a water activity meter. In this way, the water activity of all samples under different temperature and humidity conditions is tested. The moisture content of the corresponding samples under each humidity condition is tested using an oven drying method. In this way, the moisture content of all samples under different temperature and humidity conditions is tested.

5. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 3, characterized in that, In step S3: The moisture content of each sample under certain temperature and humidity conditions is tested using the oven drying method. Specifically, the corresponding samples placed on numbered sample trays under certain temperature and humidity conditions are weighed and recorded as m. 湿+盘 After the corresponding samples reach equilibrium under various humidity levels, the sample trays are dried in an oven, then covered, removed, and placed in a desiccator to cool to room temperature. The trays are then immediately weighed and recorded as m. 干+盘 Then, the moisture content x of the corresponding sample under certain temperature and humidity conditions is calculated according to formula (1). In this way, the moisture content test of all samples under certain temperature and different humidity conditions is completed. （1） In equation (1), m 盘 This indicates the quality of the sample tray.

6. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 5, characterized in that, In step S1: the drying temperature in the oven is controlled at 100±1℃, and the drying time is controlled at 2-3 hours. The dry weight of the corresponding sample is recorded as m. 干 ; In step S3: When testing the moisture content of each sample under certain temperature and humidity conditions using the oven drying method, the drying temperature in the oven is controlled at 100±1℃, and the drying time is controlled at 2-3h.

7. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 1, characterized in that, In step S1: the auxiliary material samples include filter rods and small box label paper.

8. The method for predicting the equilibrium water activity and equilibrium moisture content of tobacco shreds after cigarette packaging according to claim 7, characterized in that, In step S2: the original water activity range of the tobacco shreds under certain temperature and humidity conditions before packaging is 0.5-0.7, and the original water activity range of the filter rod and the small box label paper under certain temperature and humidity conditions before packaging is 0.2-0.

9. In step S4: the water activity range of the mixed system after cigarette packaging to reach equilibrium is 0.5-0.7; the equilibrium moisture content of the tobacco shreds after cigarette packaging is 8-15%.

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