Method for evaluating tobacco leaf moisture change capacity and application thereof

Abstract

The present application relates to a kind of evaluation methods of tobacco moisture change ability and its application, the evaluation method includes: (1) respectively establishing the dry basis moisture content y of tobacco at n temperature points with humidity x changes scatter diagram, equation y=d+m×exp (-kx) is used to carry out fitting, respectively constant m, d and k are added, the equilibrium moisture content a of tobacco at each temperature point under 0 humidity is obtained;Wherein n≥3;(2) establish the equilibrium moisture content a of tobacco under 0 humidity with temperature t scatter diagram, equation a=f×t+c is used to carry out fitting, obtain the theoretical moisture content c under absolute zero, absolute dry condition and constant f, and with c as characteristic value, the moisture change ability of tobacco is evaluated.The evaluation method used in the present application comprehensively considers the influence of thermodynamics and dynamics, realizes more scientific and comprehensive evaluation to the moisture change ability of tobacco, and the method is high in accuracy and high in precision, can be widely applied in the screening of tobacco raw material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tobacco, in particular to a method for evaluating the moisture change capacity of tobacco leaves and application thereof. BACKGROUND

[0002] Moisture is one of the important factors affecting the quality of cigarettes. During the processing and storage of cigarettes, moisture will undergo hygroscopic and dehumidification phenomena with the change of temperature and humidity. In order to study the change of tobacco moisture, dynamic water adsorption method and moisture isotherm adsorption model have been widely applied, and a series of evaluation methods have been developed. Lou Jia-ying et al. applied dynamic water adsorption method to analyze the moisture retention mechanism of tobacco raw materials such as cut tobacco and expanded tobacco. However, the sample amount required by the dynamic water adsorption instrument in the above-mentioned research is several tens of milligrams or several grams, which is quite different from the weight of the tobacco in conventional cigarettes, and thus errors may occur when analyzing the moisture change process of the tobacco in cigarettes. The sample amount required by SPSx dynamic water adsorption analyzer during testing has a wide range, which can cover the weight of a single cigarette. At present, SPSx dynamic water adsorption analysis method has been successfully applied to many related fields such as pharmaceuticals, food, and materials, but there are few reports on its application in tobacco.

[0003] In addition, there are still few methods for evaluating the moisture change capacity of tobacco and tobacco products. The main method is to place the tobacco sample into a dryer containing different concentrations of sulfuric acid (to adjust different humidity) or a constant temperature and humidity box (laboratory) under certain temperature and humidity conditions, take samples regularly and weigh them, convert the weight into moisture content, and draw a moisture content-time relationship curve for comparison.

[0004] CN201517986U developed a method for measuring the moisture content of tobacco using a glove box. This method avoids the influence of the sampling process on the stable temperature and humidity environment of the tobacco sample, and the obtained tobacco moisture content-time curve is more accurate. Compared with the above-mentioned method, this method has obvious improvement in the measurement method, but it still stays at the qualitative comparison level in the evaluation method. CN102128763A proposes a new method for evaluating the moisture retention performance: using DVS dynamic water adsorption analyzer to measure the change of moisture content of cut tobacco with time under constant temperature and humidity conditions, when the tobacco sample reaches equilibrium, measuring the dry basis weight of cut tobacco, calculating the dry basis moisture content M t of the tobacco sample at time t, and drawing the change curve of dry basis moisture content M t with time t; when 0.4 < M t -M e / M0-M e < 1.0, the dry basis moisture content M t of cut tobacco at time t is less than 1.0, and the dry basis moisture content M 0.5The linear relationship is met, and the slope of the obtained straight line is the rate constant k, and the k value can be used to evaluate the moisture retention performance of the tobacco shred. CN102636407A discloses a tobacco physical moisture retention performance test method, which comprises the steps of adding a tobacco moisture retention agent and water in a tobacco shred sample, weighing the sample tobacco shred bottle, calculating the instantaneous moisture content at different times, and comparing the water loss rate curves.

[0005] However, most of the above methods describe the moisture change ability in a certain temperature and humidity change range, cannot comprehensively consider the factors in different temperature and humidity ranges, and cannot represent the moisture change ability of tobacco leaves, which is not convenient for evaluating the moisture absorption and loss ability of different tobacco leaves. SUMMARY

[0006] To solve the above technical problems, the present application provides an evaluation method for the moisture change ability of tobacco leaves and its application. The evaluation method adopted by the present application comprehensively considers the influence of thermodynamics and kinetics, realizes more scientific and comprehensive evaluation of the moisture change ability of tobacco leaves, and has high accuracy and precision, and can be widely applied in the screening of tobacco raw materials.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides an evaluation method for the moisture change ability of tobacco leaves, which comprises:

[0009] (1) respectively establishing the scatter plot of the moisture content y of tobacco leaves on a dry basis changing with humidity x at n temperature points, applying the equation y=d+m*exp(-kx) for fitting, respectively obtaining constants m, d and k, adding m and d to obtain the equilibrium moisture content a of tobacco leaves at 0 humidity at each temperature point; wherein n≥3 (for example, it can be 3, 5, 8, 10, 15, etc.);

[0010] (2) establishing the scatter plot of the equilibrium moisture content a of tobacco leaves at 0 humidity and the temperature t, applying the equation a=f*t+c for fitting, obtaining the theoretical moisture content c under the absolute zero and absolute dry conditions and the constant f, and taking c as a characteristic value to evaluate the moisture change ability of tobacco leaves.

[0011] The moisture change ability of tobacco leaves according to the present application refers to the ability of tobacco leaves to lose or absorb water in a low-humidity or high-humidity environment. The greater the moisture change of tobacco leaves, the stronger the moisture change ability of tobacco leaves.

[0012] In the prior art, the equilibrium moisture content of tobacco leaves is usually tested at a specific temperature and humidity, and then the moisture change ability of tobacco leaves is evaluated. This method ignores the temperature influence factor and cannot comprehensively represent the moisture absorption and loss ability of tobacco leaves.

[0013] The present application establishes the scatter plot of the equilibrium moisture content of tobacco at different temperatures under the humidity change, applies the equation y=d+m*exp(-kx) to fitting, obtains the equilibrium moisture content a of tobacco under the condition of "0" humidity; then establishes the scatter plot of a and temperature t, applies the equation a=f*t+c to fitting, obtains the theoretical moisture content c under the condition of "absolute zero, absolute dryness". Because the water in tobacco only has potential energy under the condition of "absolute zero, absolute dryness", no kinetic energy, therefore the c value at this time can represent the motive power of water diffusion in tobacco, thereby representing the change ability of water in tobacco.

[0014] The evaluation method adopted by the present application comprehensively considers the influence of thermodynamics and dynamics, realizes more scientific and comprehensive evaluation of the change ability of tobacco moisture, and has high accuracy and precision, and can be widely applied to the screening of tobacco raw materials.

[0015] Preferably, the n temperature points in step (1) are each independently selected from 5-50℃ (for example, can be 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃), preferably 10-35℃.

[0016] Preferably, the humidity at the n temperature points in step (1) is each independently selected from 10-80% (for example, can be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%).

[0017] Preferably, the change step of the humidity at the n temperature points in step (1) is each independently selected from 1-10% (for example, can be 1%, 2%, 4%, 6%, 8%, 10%).

[0018] Preferably, in step (1), the tobacco at each humidity is dried, and the dry basis moisture content y is calculated according to the mass before and after drying, and the calculation formula is: y=(m0-m1) / m1, wherein m0 is the mass of tobacco before drying, and m1 is the mass of tobacco after drying.

[0019] Preferably, the greater the theoretical moisture content c value in step (2), the stronger the change ability of tobacco moisture.

[0020] Preferably, the evaluation method comprises:

[0021] (1) respectively establish the scatter plot of the dry basis moisture content y of tobacco at n temperature points under the change of humidity x, apply the equation y=d+m*exp(-kx) to fitting, respectively obtain the constants m, d and k, add m and d to obtain the equilibrium moisture content a of tobacco at 0 humidity at each temperature point; wherein the humidity at the n temperature points is each independently selected from 10-80%, and the change step of the humidity is each independently selected from 1-10%; n≥2;

[0022] (2) Establishing the scatter plot of the equilibrium moisture content a of tobacco at 0 humidity and the temperature t, applying the equation a = f x t + c to fitting, obtaining the theoretical moisture content c under the absolute zero degree and the absolute dry condition and the constant f, and taking c as the characteristic value to evaluate the moisture change capacity of tobacco.

[0023] In the second aspect, the application provides an application of the evaluation method of the moisture change capacity of tobacco according to the first aspect of the application in the screening of tobacco.

[0024] Compared with the prior art, the application has at least the following beneficial effects:

[0025] The application obtains the theoretical moisture content c under the absolute zero degree and the absolute dry condition by investigating the change trend of the equilibrium moisture content of tobacco at different temperatures and applying the equations y = d + m x exp (-kx) and a = f x t + c to fitting. The evaluation method comprehensively considers the influence of thermodynamics and dynamics, realizes more scientific and comprehensive evaluation of the moisture change capacity of tobacco, and has high accuracy and precision, and can be widely applied to the screening of tobacco raw materials. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the application, the application is listed as follows. It should be understood by those skilled in the art that the examples are only used to help understand the application and should not be regarded as a specific limitation on the application.

[0027] Example 1

[0028] The example provides an evaluation method of the moisture change capacity of tobacco, which specifically comprises the following steps:

[0029] (1) 0.7g of tobacco sample is weighed and placed in an SPSx dynamic moisture analyzer, the temperature of the SPSx dynamic moisture analyzer is adjusted to 10℃, and the relative humidity is adjusted to 60%; after reaching equilibrium, the environmental humidity is first increased from 60% to 80% at a step of 5%, and then decreased from 80% to 10% at a step of 5%; after the end, the dry basis weight of tobacco is measured by an oven method, the dry basis moisture content y of tobacco under each humidity condition is analyzed, and the calculation formula is: y = (m0-m1) / m1, wherein m0 is the mass of tobacco before drying, and m1 is the mass of tobacco after drying;

[0030] (2) The same amount of tobacco sample is weighed again, the temperature is adjusted to 12℃, 15℃, 18℃, 20℃, 22℃, 25℃, 28℃, 30℃, 32℃, 35℃, 38℃ and 40℃ respectively, and the operation in step (1) is repeated;

[0031] (3) using the equation y = d + m x exp(-kx) to fit the scatter plot of the dry basis moisture content y of the tobacco at each temperature point versus the humidity x, to obtain constants m, d and k respectively, and adding m and d to obtain the equilibrium moisture content a of the tobacco at 0 humidity at each temperature point;

[0032] (4) establishing a scatter plot of the equilibrium moisture content a of the tobacco at 0 humidity versus the temperature t, and using the equation a = f x t + c to fit, to obtain the theoretical moisture content c under absolute zero and absolute dry conditions and the constant f, and using c as a characteristic value to evaluate the moisture change capacity of the tobacco.

[0033] Example 2

[0034] The embodiment provides an evaluation method for the moisture change capacity of tobacco, specifically comprising the following steps:

[0035] (1) weighing 0.7 g of a tobacco sample, placing it in an SPSx dynamic moisture analyzer, adjusting the temperature of the SPSx dynamic moisture analyzer to 10°C and the relative humidity to 55%; after reaching equilibrium, increasing the environmental humidity to 79% by 6% steps, and then decreasing it to 13% by 6% steps; after ending, determining the dry basis weight of the tobacco by the oven method, analyzing the dry basis moisture content y of the tobacco under each humidity condition, and the calculation formula is: y = (m0-m1) / m1, wherein m0 is the mass of the tobacco before drying, and m1 is the mass of the tobacco after drying;

[0036] (2) weighing an equal amount of tobacco samples again, adjusting the temperature to 12°C, 15°C, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 38°C and 40°C respectively, and repeating the operation in step (1);

[0037] (3) using the equation y = d + m x exp(-kx) to fit the scatter plot of the dry basis moisture content y of the tobacco at each temperature point versus the humidity x obtained in steps (1)-(2), to obtain constants m, d and k respectively, and adding m and d to obtain the equilibrium moisture content a of the tobacco at 0 humidity at each temperature point;

[0038] (4) establishing a scatter plot of the equilibrium moisture content a of the tobacco at 0 humidity versus the temperature t, and using the equation a = f x t + c to fit, to obtain the theoretical moisture content c under absolute zero and absolute dry conditions and the constant f, and using c as a characteristic value to evaluate the moisture change capacity of the tobacco.

[0039] Example 3

[0040] The embodiment provides an evaluation method for the moisture change capacity of tobacco, specifically comprising the following steps:

[0041] (1) Weigh 0.7g of tobacco leaf sample and place it in the SPSx dynamic moisture analyzer. Adjust the temperature of the SPSx dynamic moisture adsorption analyzer to 10℃ and the relative humidity to 65%. After reaching equilibrium, the ambient humidity is increased to 77% in 4% increments and then decreased to 13% in 4% increments. After the end, the dry basis weight of the tobacco leaf is determined by the oven drying method. The dry basis moisture content y of the tobacco leaf under various humidity conditions is analyzed. The calculation formula is: y=(m0-m1) / m1, where m0 is the mass of the tobacco leaf before drying and m1 is the mass of the tobacco leaf after drying.

[0042] (2) Weigh an equal amount of tobacco leaf sample again, and adjust the temperature to 12℃, 15℃, 18℃, 20℃, 22℃, 25℃, 28℃, 30℃, 32℃, 35℃, 38℃, and 40℃ respectively, and repeat the operation in step (1).

[0043] (3) Apply the equation y=d+m×exp(-kx) to fit the scatter plot of the dry basis moisture content y of tobacco leaves at each temperature point obtained in steps (1)-(2) to obtain constants m, d and k respectively. Add m and d to obtain the equilibrium moisture content a of tobacco leaves at "0" humidity at each temperature point.

[0044] (4) Establish a scatter plot of equilibrium moisture content a versus temperature t when the tobacco leaves are at "0" humidity. Apply the equation a = f × t + c to fit the data and obtain the theoretical moisture content c and constant f under absolute zero and absolute dry conditions. Use c as the characteristic value to evaluate the ability of tobacco leaves to change moisture content.

[0045] Test Example 1

[0046] The tobacco leaf samples 1-10 were tested using the evaluation method for tobacco leaf moisture change capability provided in the above embodiments, with each sample being tested 20 times.

[0047] In addition, the above tobacco leaf samples were placed in an environment of 10℃ and 80% humidity. After reaching equilibrium, the dry basis weight of the tobacco leaves was measured by the oven drying method to obtain the dry basis moisture content 1. Then, the environment was adjusted to 35℃ and 10% humidity. After reaching equilibrium, the dry basis weight of the tobacco leaves was measured by the oven drying method to obtain the dry basis moisture content 2. The decrease in dry basis moisture content was calculated by combining the two dry basis moisture contents.

[0048] The test results are summarized in Table 1.

[0049] Table 1

[0050]

[0051]

[0052] Test results show that:

[0053] The evaluation method of the tobacco leaf moisture change ability has high precision for testing different tobacco leaf samples, and the moisture change ability of the tobacco leaf samples is consistent with the descending order of the dry basis moisture content, indicating that the evaluation method can accurately evaluate the moisture change ability of the tobacco leaf samples.

[0054] The applicant declares that the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any change or replacement within the technical scope disclosed by the present application can be easily thought of by any person skilled in the art, and falls within the protection scope and disclosure range of the present application.

Claims

1. A method for evaluating the water changeability of tobacco leaves, characterized by, The evaluation method comprises: (1) respectively establishing n temperature points of tobacco dry basis moisture content y with humidity x changes of scatter plot, application equation y = d + m × exp (-kx) fitting, respectively, constant m, d and k, m and d are added, get each temperature point under the equilibrium moisture content of tobacco 0 humidity a; wherein n≥3; (2) the establishment of tobacco 0 humidity when the equilibrium moisture content a and temperature t scatter plot, application equation a = f × t + c fitting, get the theoretical moisture content c and constant f under the condition of absolute zero, absolute dry, and take c as the characteristic value of tobacco moisture change ability evaluation.

2. The evaluation method according to claim 1, characterized by The n temperature points in step (1) are each independently selected from 5-50℃.

3. The evaluation method according to claim 2, characterized by, The n temperature points in step (1) are each independently selected from 10-35℃.

4. The evaluation method according to any one of claims 1 to 3, characterized by, The humidity under the n temperature points in step (1) is each independently selected from 10-80%.

5. The evaluation method according to any one of claims 1 to 3, characterized by, The humidity change step length under the n temperature points in step (1) is each independently selected from 1-10%.

6. The evaluation method according to any one of claims 1 to 3, characterized by, Step (1) dry tobacco under each humidity, according to the mass before and after drying to calculate the dry basis moisture content y, the calculation formula is: y = (m0-m1) / m1, wherein m0 is the mass of tobacco before drying, m1 is the mass of tobacco after drying.

7. The evaluation method according to any one of claims 1 to 3, characterized by, The greater the theoretical moisture content c value in step (2), the stronger the tobacco moisture change ability.

8. The evaluation method according to any one of claims 1 to 3, characterized by, The evaluation method comprises: (1) respectively in 5-50℃ under n temperature points of tobacco dry basis moisture content y with humidity x changes of scatter plot, application equation y = d + m × exp (-kx) fitting, respectively, constant m, d and k, m and d are added, get each temperature point under the equilibrium moisture content of tobacco 0 humidity a; wherein, n temperature points under the humidity is each independently selected from 10-80%, the humidity change step length is each independently selected from 1-10%; n≥3; (2) the establishment of tobacco 0 humidity when the equilibrium moisture content a and temperature t scatter plot, application equation a = f × t + c fitting, get the theoretical moisture content c and constant f under the condition of absolute zero, absolute dry, and take c as the characteristic value of tobacco moisture change ability evaluation.

9. The application of the tobacco moisture change ability evaluation method according to any one of claims 1-8 in tobacco screening.

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