CN102221511B - Method for testing moisture adsorption-desorption performance of tobacco leaf - Google Patents

Abstract

The invention relates to the field of tobacco leaf detection, in particular to a method for testing and evaluating moisture adsorption-desorption performance of tobacco leaf and moisture retention performance of tobacco leaf humectant. In the invention, the moisture adsorption balance of the tobacco leaf under the condition of high humidity is researched by adopting a dynamic water adsorption analysis method; subsequently, according to the dynamics rule of water dissipation in dry environment, a linear fitting chart is drawn on t0.5 by the moisture content Mt of tobacco leaf at the time t, thus working out the water dissipation rate constant k according to the slope of the beeline; and the initial moisture content M0 of the cut tobacco and the water dissipation rate constant k are used as basis for evaluating the moisture adsorption-desorption performance and the moisture retention performance of tobacco leaf. The method can be used for testing the performance of the tobacco humectant and sieving the cigarette humectant, etc. Compared with the traditional method, the method has the advantages of short test time, high automation degree, high simpleness and practicability, good veracity and repeatability and the like.

Description

A kind of test method of moisture absorption and dehumidification performance of tobacco leaves

technical field

The invention relates to the field of tobacco leaf detection, in particular to a new method for testing and evaluating the moisture absorption and dehumidification characteristics of tobacco leaves and the moisturizing performance of tobacco leaf moisturizing agents.

Background technique

Tobacco leaf moisture, also known as tobacco leaf moisture content and tobacco leaf moisture content, plays an important role in tobacco production and processing, and is one of the important components of tobacco and its products. The moisture absorption and dehumidification process of tobacco runs through the whole process of cigarette production, storage and use. In this series of links, there are strict controls and requirements on the moisture of tobacco leaves, and different moisture contents are required to adapt to it. Among them, the temperature, humidity and moisture content and their changes have great impact on the loss of raw materials and the internal quality of products. have an extremely important impact. Therefore, it is of great significance for the production and use of cigarettes to study the hygroscopicity and dehydration properties of tobacco leaves (silk) and their moisture retention properties.

At present, the standard experimental method is to use a drier filled with saturated salt solution or a constant temperature and humidity box to control the temperature and humidity of the tobacco leaf sample environment. After the tobacco leaves reach the balance of moisture absorption and dehumidification, manually measure with an electronic balance, calculate the moisture content, and draw The adsorption isotherms of different tobacco leaf samples were obtained and compared. However, this static test method takes a very long time, usually 30-60 days, during which a lot of manual operations are required, resulting in inaccurate results, poor repeatability and even deterioration of tobacco leaves. It has seriously failed to meet the requirements of the development of tobacco science and technology.

Contents of the invention

The purpose of the present invention is to provide a test method suitable for the moisture absorption and dehumidification characteristics of tobacco leaves and the moisture retention performance of tobacco leaf humectant to solve the problems in the above-mentioned prior art.

Based on the actual situation of tobacco production and smoking, after the cut tobacco reaches moisture absorption equilibrium under relatively high humidity conditions, the initial moisture content and the early dehumidification rate in a dry environment are crucial to the research on the moisture absorption and dehumidification characteristics and moisture retention performance of tobacco leaves. important. The present invention utilizes the dynamic moisture adsorption analysis system to study the moisture loss characteristics of tobacco leaves in a dry environment after moisture absorption balance under relatively high humidity conditions. The results show that there is a good linearity between the dry basis moisture content of tobacco leaves in the early stage of moisture loss and the square root of time Relation: Mt=-k×t ^0.5 +M ₀ . In the formula, the initial moisture content M ₀ reflects the moisture absorption capacity of tobacco leaves, and the rate constant k value is related to its dehumidification characteristics, and it is used as the basis for evaluating the moisture absorption and dehydration characteristics and moisture retention performance of tobacco leaves. Compared with the traditional method, it has the advantages of short test time, high degree of automation, convenience and applicability, good accuracy and repeatability, etc.

The present invention adopts the following technical solutions to solve the above technical problems.

A method for testing moisture absorption and dehumidification properties of tobacco leaves, comprising the steps of:

1) Sample pretreatment: process the tobacco leaf sample into a uniform and regular shredded tobacco sample, and balance the shredded tobacco sample in a constant temperature and humidity box for later use;

2) Weigh a certain quality of cut tobacco sample to be tested, and measure the change of the quality of the cut tobacco sample with time t under a dry environment condition for the cut tobacco sample after moisture absorption equilibrium in a high-humidity environment under a certain temperature condition; When the water is out of balance, measure the dry basis weight of the shredded tobacco sample; from the curve of the weight of the shredded tobacco sample with time t and the measured dry basis weight, calculate the dry basis moisture content Mt of the shredded tobacco sample at time t, and draw the dry basis The change curve of moisture content Mt with the square root t ^0.5 of time;

3) In the change curve of Mt with t ^0.5 obtained in step 2), within the period of time when the moisture content on a dry basis satisfies 0.4<(Mt-Me)/(M ₀ -Me)<1.0, use Mt to make linearity with t ^0.5 In the fitting diagram, the slope of the obtained straight line is the water loss rate constant k; in the formula, M ₀ is the dry basis moisture content of the cut tobacco at the initial moment, Mt is the dry basis moisture content of the cut tobacco at time t, and Me is the cut tobacco when the water loss balance is reached. moisture content on a dry basis;

4) Judging the moisture absorption and dehumidification performance of tobacco leaves according to the initial moisture content M ₀ and the water loss rate constant k: the larger the M ₀ value, the better the moisture absorption performance of the tobacco leaves, and the smaller the k value, the better the moisture retention performance of the tobacco leaves .

In step 1), the equilibration time of the shredded tobacco sample is at least 48 hours.

In step 1), the temperature and humidity in the constant temperature and humidity box depends on the initial equilibrium conditions of the experiment. The temperature in the constant temperature and humidity box is 15-40°C and the relative humidity is 59%-71%; preferably, The temperature in the constant temperature and humidity box is 20-25°C.

In step 2), the weight of the shredded tobacco sample is 1.000g-3.000g.

In step 2), the temperature condition is 15-40°C; preferably, the temperature condition is 20-25°C.

In step 2), the relative humidity of the high-humidity environment is 60%-70%.

In step 2), the relative humidity of the dry environment is 20%-40%; preferably, the relative humidity of the dry environment is 30%-40%.

In step 2), the dry basis weight of the cut tobacco sample is determined using the oven method: put the sample basket in an oven, dry it at 100°C for 2 hours, put it in a desiccator to cool, and weigh it with an analytical balance to obtain the dry weight of the sample. basis weight.

In step 2), the quality of the shredded tobacco sample after the moisture absorption equilibrium in the high humidity environment is measured by the dynamic moisture adsorption analysis system as a function of time t under dry environmental conditions; the balance control mode of the dynamic moisture adsorption analysis system can be set as Time-controlled mode or rate-controlled mode.

In step 3), during the time period when the dry basis moisture content Mt satisfies 0.4<(Mt-Me)/(M ₀ -Me)<1.0, the correlation model between the dry basis moisture content Mt of shredded tobacco and time t is Mt= -k×t ^0.5 +M ₀ . In the formula, M ₀ is the dry basis moisture content of cut tobacco at the initial moment, Mt is the dry basis moisture content of cut tobacco at time t, and Me is the dry basis moisture content of cut tobacco when the water dispersion imbalance is reached.

The test method for the moisture absorption and dehumidification performance of tobacco leaves of the invention can also be used to investigate the performance of tobacco humectants and to screen cigarette humectants. By comparing the initial moisture content M ₀ and the water loss rate constant k of tobacco with humectant added and blank tobacco, the humectant performance of tobacco humectant is investigated, and suitable cigarette humectants are screened.

The test method of the moisturizing performance of the tobacco leaf humectant of the present invention comprises the following steps:

The shredded tobacco sample added with humectant and blank shredded tobacco sample were tested according to the test method for moisture absorption and dehumidification properties of tobacco leaves mentioned above, and the initial moisture content _M0 and water loss of shredded tobacco sample added with humectant and blank shredded tobacco sample were respectively obtained. The rate constant k is to compare the M ₀ and k values of the shredded tobacco sample with the humectant added and the blank shredded tobacco sample respectively, and judge the moisture retention performance of the tobacco leaf humectant: the larger the M ₀ value, the better the tobacco leaf humectant can improve the tobacco leaf humectant. The lower the k value, the lower the moisture absorption performance of tobacco leaves, indicating that the tobacco leaf humectant can enhance the moisture retention performance of tobacco leaves.

The beneficial effects of the present invention are:

1) by establishing the dry basis moisture content of shredded tobacco and the correlation model of time, it is proposed to use the initial dry basis moisture content _M of tobacco leaves and the rate constant k value as the basis for evaluating the moisture absorption and dehumidification characteristics of tobacco leaves;

2) Short test time: the test time is reduced from 30-60 days to 15-20 hours;

3) Simple and applicable, high degree of automation: after loading the sample, the computer automatically completes a series of operations such as weighing and recording under the set temperature and humidity conditions;

4) Good accuracy and repeatability: the relative standard deviation of the results of 5 parallel experiments is less than 1.5%; it can reflect the subtle changes of moisture content of tobacco leaf samples with time.

Description of drawings

Fig. 1 is the schematic diagram of the dynamic moisture adsorption analysis system used in the present invention;

In the figure: 1 balance controller, 2 flow controller, 3 incubator, 4 temperature generator, 5 ultramicro balance, 6 balance protective gas, 7 sample pan, 8 reference pan, 9DPA (dew point analyzer), 10 temperature Probe, 11N ₂ cylinders.

Figure 2 is the change curve of the dry basis moisture content of flue-cured tobacco B2F and C2F tobacco leaves from place A with time (t ^0.5 ) and the comparison of their linear fitting diagrams (0.4<(Mt-Me)/(M ₀ -Me)<1.0) .

Figure 3 is the change curve of the dry basis moisture content of flue-cured tobacco B2F in A and B with time (t ^0.5 ) and the comparison of its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0 ).

Figure 4 is the change curve of the square root (t ^0.5 ) of moisture content of flue-cured tobacco B2F and Burley tobacco leaves from place A with time (t 0.5 ) and the comparison of its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0 ).

Fig. 5 is the change curve of the dry basis moisture content with the square root of time (t ^0.5 ) and its linear fitting graph comparison after adding humectant a and b to the shredded tobacco of the blank control and its linear fitting (0.4<(Mt-Me)/(M ₀ -Me)<1.0).

Detailed ways

The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the protection scope of the present invention.

The frame diagram of the dynamic moisture adsorption analysis system used in the present invention is shown in Fig. 1 . The system consists of an ultra-micro electronic balance 5, a gas flow controller 2 and the like. The main part of the instrument is placed in a temperature-controllable incubator 3, and the electronic balance in the middle is placed in a separate isolation area; a water vapor generating device is installed at the rear of the instrument; the computer is connected through the data acquisition card and RS-232 respectively. The serial port connects the gas flow controller 2 and the balance controller 1. When the instrument is running, the gas flow controller 2 controls the flow of the dry carrier gas and the water vapor saturated carrier gas. The two carrier gases are mixed to obtain a series of airflows with a set humidity, which flow through the sample to be tested and the reference area at the same time to make the moisture The adsorption or desorption experiment can reach equilibrium as soon as possible, and the temperature and relative humidity of the gas flowing through the sample are controlled by the temperature probe 10 and DPA 9. The computer records the weight change of the sample at different humidity and at different times in real time through the electronic balance.

Sample pretreatment: the tobacco leaves required in the following examples 1-4 were processed into uniform cut tobacco and then mixed evenly. Equilibrate in a constant temperature and humidity chamber (22°C, relative humidity 60%±1%) for 48 hours before use.

Example 1

Use an analytical balance to weigh 1.000g of flue-cured tobacco B2F (or C2F) shredded tobacco from A origin, spread it flat in the microbalance sample basket of the dynamic moisture adsorption analysis system, and examine the higher relative humidity (60% relative humidity) at 22°C After equilibrium under the condition, the change of the quality of shredded tobacco over time in a dry environment with a relative humidity of 30%, the balance control mode is set to the rate control mode (dm/dtMode) dm/dt=0.0005 (%/min). The computer automatically records the sample weight every 1 minute, and the instrument ends weighing when the smoke sample reaches the water dispersion imbalance. Put the sample basket into the oven, refer to the oven method, dry at 100°C for 2 hours, and weigh it with an analytical balance to obtain the dry weight of the sample. From the data chart of the change curve of the detected sample weight with time and relative humidity, combined with the dry weight, calculate the dry basis moisture content value at the corresponding time and draw the data chart: the change of the square root of the dry basis moisture content of tobacco leaves with time (t ^0.5 ) Comparison of the curve and its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0), as shown in FIG. 2 . The number of repeated determinations was n=5, the fitting coefficient R ² >0.998, and the relative standard deviation RSD of the repeatability determination was <1.0%.

Flue-cured tobacco B2F from place A: initial moisture content M ₀ =15.85%, rate constant k=0.807%/min ^1/2 .

Flue-cured tobacco C2F from place A: initial moisture content M ₀ =16.04%, rate constant k=0.822%/min ^1/2 .

The initial moisture content M ₀ of flue-cured tobacco from A origin is slightly lower, indicating that its hygroscopicity is slightly worse than that of C2F, but its dehumidification rate constant k is also slightly smaller, indicating that its moisture retention ability is slightly stronger than that of C2F.

Example 2

Weigh 1.000g flue-cured tobacco B2F from A origin (or B2F flue-cured tobacco from B origin) cut tobacco with an analytical balance, spread it flat in the microbalance sample basket of the dynamic moisture adsorption analysis system, and investigate the higher relative humidity (relative humidity After balancing under the condition of 60%), the quality of shredded tobacco changes with time in a dry environment with a relative humidity of 30%, and the balance control mode is set to the rate control mode (dm/dt Mode) dm/dt=0.0005 (%/min). The computer automatically records the sample weight every 1 minute, and the instrument ends weighing when the smoke sample reaches the water dispersion imbalance. Put the sample basket into the oven, refer to the oven method, dry at 100°C for 2 hours, and weigh it with an analytical balance to obtain the dry weight of the sample. From the data chart of the change curve of the detected sample weight with time and relative humidity, combined with the dry weight, calculate the dry basis moisture content value at the corresponding time and draw the data chart: the change of the square root of the dry basis moisture content of tobacco leaves with time (t ^0.5 ) Comparison of the curve and its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0), as shown in FIG. 3 . The number of repeated measurements n=5, the fitting coefficient R ² >0.997, and the relative standard deviation RSD of repeatability determination <1.2%.

Flue-cured tobacco B2F from place A: initial moisture content M ₀ =15.85%, rate constant k=0.807%/min ^1/2 .

Flue-cured tobacco B2F from place B: initial moisture content M ₀ =14.76%, rate constant k=0.574%/min ^1/2 .

The initial moisture content of flue-cured tobacco B2F from A origin is significantly higher than that of B2F from B origin, indicating that it has stronger hygroscopicity, but its dehumidification rate constant k is also significantly higher than that of B2F from B origin, indicating that its moisture retention ability is worse than that of B origin flue-cured tobacco.

Example 3

Weigh 1.000g cut flue-cured tobacco B2F (or Burley tobacco) from B origin with an analytical balance, spread it flat in the microbalance sample basket of the dynamic moisture adsorption analysis system, and investigate the higher relative humidity (relative humidity 60°C) at 22°C %) condition, the change of the quality of shredded tobacco over time in a dry environment with a relative humidity of 30%, and the balance control mode is set to the rate control mode (dm/dt Mode) dm/dt=0.0005 (%/min). The computer automatically records the sample weight every 1 minute, and the instrument ends weighing when the smoke sample reaches the water dispersion imbalance. Put the sample basket into the oven, refer to the oven method, dry at 100°C for 2 hours, and weigh it with an analytical balance to obtain the dry weight of the sample. From the data chart of the change curve of the detected sample weight with time and relative humidity, combined with the dry weight, calculate the dry basis moisture content value at the corresponding time and draw the data chart: the change of the square root of the dry basis moisture content of tobacco leaves with time (t ^0.5 ) Comparison of the curve and its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0), as shown in FIG. 4 . The number of repeated measurements n=5, the fitting coefficient R ² >0.998, and the relative standard deviation RSD of repeatability determination <1.2%.

Flue-cured tobacco B2F from place B: initial moisture content M ₀ =14.76%, rate constant k=0.574%/min ^1/2 .

A Burley tobacco: initial moisture content M ₀ =13.98%, rate constant k=0.689%/min ^1/2 .

The initial moisture content of Burley tobacco was lower than that of B2F flue-cured tobacco from origin B, and its dehumidification rate constant k was also significantly higher, indicating that its hygroscopicity and moisture retention capacity were worse than flue-cured tobacco from origin B.

Example 4

Weigh a certain shredded tobacco and spray a certain amount of humectant a and b respectively, and spray the same amount of water for the control sample; then put the sample into a constant temperature and humidity box to balance for 48 hours; weigh 1.000g blank control shredded tobacco with an analytical balance (or spray humectant A and B shredded tobacco), spread it evenly in the microbalance sample basket of the dynamic moisture adsorption analysis system, at 22 ° C, investigate the condition of higher relative humidity (relative humidity 60%) after equilibrium , the quality of shredded tobacco changes with time in a dry environment with a relative humidity of 30%, and the balance control mode is set to the rate control mode (dm/dt Mode) dm/dt=0.0005 (%/min). The computer automatically records the sample weight every 1 minute, and the instrument ends weighing when the smoke sample reaches the water dispersion imbalance. Put the sample basket into the oven, refer to the oven method, dry at 100°C for 2 hours, and weigh it with an analytical balance to obtain the dry weight of the sample. From the data chart of the change curve of the detected sample weight with time and relative humidity, combined with the dry weight, calculate the dry basis moisture content value at the corresponding time and draw the data chart: the change of the square root of the dry basis moisture content of tobacco leaves with time (t ^0.5 ) Comparison of the curve and its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0), as shown in FIG. 5 . The number of repeated measurements n=5, the fitting coefficient R ² >0.997, and the relative standard deviation RSD of repeatability determination <1.5%.

Blank control: initial moisture content M ₀ =16.22%, rate constant k=0.724%/min ^1/2 .

Add humectant a: initial water content M ₀ =16.96%, rate constant k=0.762%/min ^1/2 .

Add humectant b: initial water content M ₀ =16.69%, rate constant k=0.683%/min ^1/2 .

After spraying humectant a, the initial moisture content of shredded tobacco increased significantly compared with the blank control, but the rate constant k did not change significantly, indicating that humectant a could improve the hygroscopic performance of shredded tobacco, but had little effect on its moisturizing performance.

After spraying humectant b, the initial moisture content of shredded tobacco slightly increased compared with the blank control, while the rate constant k decreased significantly, indicating that humectant b can affect the dehumidification performance of shredded tobacco and enhance its moisturizing performance.

Sample pre-treatment: the tobacco leaves required in Example 5 were processed into uniform cut tobacco and then mixed evenly. Equilibrate for 48 hours in a constant temperature and humidity chamber (25° C., relative humidity 70% ± 1%) before use.

Example 5

Use an analytical balance to weigh 2.000g of flue-cured tobacco B2F (or C2F) shredded tobacco from A origin, spread it flat in the microbalance sample basket of the dynamic moisture adsorption analysis system, and investigate the higher relative humidity (70% relative humidity) at 25°C After equilibrium under the condition, the mass change of shredded tobacco over time in a dry environment with a relative humidity of 40%, the balance control mode is set to the rate control mode (dm/dtMode) dm/dt=0.0005(%/min). The computer automatically records the sample weight every 1 minute, and the instrument ends weighing when the smoke sample reaches the water dispersion imbalance. Put the sample basket into the oven, refer to the oven method, dry at 100°C for 2 hours, and weigh it with an analytical balance to obtain the dry weight of the sample. From the data chart of the change curve of the detected sample weight with time and relative humidity, combined with the dry weight, calculate the dry basis moisture content value at the corresponding time and draw the data chart: the change of the square root of the dry basis moisture content of tobacco leaves with time (t ^0.5 ) Comparison of the curve and its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0). The number of repeated measurements n=5, the fitting coefficient R ² >0.998, and the relative standard deviation RSD of repeatability determination <1.2%.

From the initial moisture content M ₀ and the rate constant k value of flue-cured tobacco B2F from A origin and _{the initial moisture content M 0 and rate constant k value of flue-cured tobacco C2F from A origin obtained in this example: the initial moisture content M 0 of} flue-cured tobacco B2F from A origin is slightly lower , indicating that its hygroscopicity is slightly worse than that of C2F, but its dehumidification rate constant k is also slightly smaller, indicating that its moisturizing ability is slightly stronger than that of C2F.

Sample pre-treatment: the tobacco leaves required in Example 6 were processed into uniform cut tobacco and then mixed evenly. Equilibrate for 48 hours in a constant temperature and humidity chamber (20° C., relative humidity 65%±1%) for later use.

Example 6

Weigh 3.000g flue-cured tobacco B2F (or C2F) shredded tobacco from A origin with an analytical balance, spread it flat in the microbalance sample basket of the dynamic moisture adsorption analysis system, and investigate the relatively high relative humidity (relative humidity 65%) at 20°C After balancing under the same conditions, the quality of cut tobacco changes with time in a dry environment with a relative humidity of 35%, and the balance control mode is set as time control mode (Time=1200min). The computer automatically records the sample weight every 1 minute, and the instrument ends weighing when the smoke sample reaches the water dispersion imbalance. Put the sample basket into the oven, refer to the oven method, dry at 100°C for 2 hours, and weigh it with an analytical balance to obtain the dry weight of the sample. From the data chart of the change curve of the detected sample weight with time and relative humidity, combined with the dry weight, calculate the dry basis moisture content value at the corresponding time and draw the data chart: the change of the square root of the dry basis moisture content of tobacco leaves with time (t ^0.5 ) Comparison of the curve and its linear fitting diagram (0.4<(Mt-Me)/(M ₀ -Me)<1.0). The number of repeated measurements n=5, the fitting coefficient R ² >0.997, and the relative standard deviation RSD of repeatability determination <1.2%.

From the initial moisture content M ₀ and the rate constant k value of flue-cured tobacco B2F from A origin and _{the initial moisture content M 0 and rate constant k value of flue-cured tobacco C2F from A origin obtained in this example: the initial moisture content M 0 of} flue-cured tobacco B2F from A origin is slightly lower , indicating that its hygroscopicity is slightly worse than that of C2F, but its dehumidification rate constant k is also slightly smaller, indicating that its moisturizing ability is slightly stronger than that of C2F.

Claims (10)

1. the method for testing of a tobacco leaf moisture adsorption-desorption performance comprises the steps:

1) sample pre-treatments: tobacco sample is treated to tobacco sample, tobacco sample is for subsequent use after the balance in climatic chamber;

2) take by weighing the tobacco sample to be measured of certain mass, under the uniform temperature condition, measure the tobacco sample after the moisture equilibrium at dry side in the high humidity environment, the in time variation of t of its quality under the dry environment condition; When treating that tobacco sample reaches the moisture loss balance of setting, measure the butt weight of tobacco sample; By the weight of the tobacco sample in time change curve of t and measured butt weight, calculate tobacco sample t moisture content of drying base Mt constantly, and draw moisture content of drying base Mt square root t in time ^0.5Change curve;

3) Mt that step 2) obtains is with t ^0.5Change curve in, satisfy 0.4＜(Mt-Me)/(M at moisture content of drying base ₀In-Me)＜1.0 time period, with Mt to t ^0.5Make Linear Fit Chart, the absolute value of the slope of gained straight line is the moisture loss rate constants k; In the formula, M ₀Be the moisture content of drying base of initial time pipe tobacco, Mt is the constantly moisture content of drying base of pipe tobacco of t, and Me is the moisture content of drying base of pipe tobacco when reaching the moisture loss balance;

4) according to initial aqueous rate M ₀With the size of moisture loss rate constants k, judge the moisture adsorption-desorption performance of tobacco leaf: M ₀Be worth greatlyr, the moisture pick-up properties of tobacco leaf is better, and the k value is less, and the performance of keeping humidity of tobacco leaf is better.

2. the method for testing of tobacco leaf moisture adsorption-desorption performance as claimed in claim 1 is characterized in that, in the step 1), temperature is 15-40 ℃ in the described climatic chamber, and relative humidity is 59%-71%.

3. the method for testing of tobacco leaf moisture adsorption-desorption performance as claimed in claim 1 is characterized in that step 2) in, the described quality that takes by weighing tobacco sample is 1.000g-3.000g.

4. the method for testing of tobacco leaf moisture adsorption-desorption performance as claimed in claim 1 is characterized in that step 2) in, described temperature conditions is 15-40 ℃.

5. the method for testing of tobacco leaf moisture adsorption-desorption performance as claimed in claim 1 is characterized in that step 2) in, the relative humidity of described high humidity environment is 60%-70%; The relative humidity of described dry environment is 20%-40%.

6. the method for testing of tobacco leaf moisture adsorption-desorption performance as claimed in claim 1, it is characterized in that, step 2) in, adopts the tobacco sample in time variation of t of its quality under the dry environment condition after the moisture equilibrium at dry side in the dynamic water adsorption analysis system measurement high humidity environment.

7. the method for testing of tobacco leaf moisture adsorption-desorption performance as claimed in claim 6 is characterized in that step 2) in, the balance control model of described dynamic water adsorption analysis system is set as speed control model or time control model.

8. such as the method for testing of the arbitrary described tobacco leaf moisture adsorption-desorption performance of claim 1-7, it is characterized in that, in the step 3), satisfy 0.4＜(Mt-Me)/(M at moisture content of drying base Mt ₀In-Me)＜1.0 time period, the moisture content of drying base Mt of pipe tobacco and the correlation models of time t are Mt=-k * t ^0.5+ M ₀

9. such as the application in the humid keeping performance of estimating the tobacco leaf humectant of the method for testing of the arbitrary described tobacco leaf moisture adsorption-desorption performance of claim 1-8.

10. the method for testing of the humid keeping performance of a tobacco leaf humectant comprises the steps:

Respectively tobacco sample and the blank tobacco sample of adding humectant are tested according to the method for testing step of the arbitrary described tobacco leaf moisture adsorption-desorption performance of claim 1-8, and draw respectively the tobacco sample of interpolation humectant and the initial aqueous rate M of blank tobacco sample ₀With the moisture loss rate constants k, relatively add respectively the M of tobacco sample and the blank tobacco sample of humectant ₀With the size of k value, judge the humid keeping performance of tobacco leaf humectant.

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