A method for improving tobacco quality

Abstract

The present invention relates to a method for improving tobacco quality, and belongs to the technical field of tobacco processing. The method for improving tobacco quality of the present invention comprises the following steps: treating tobacco materials with a moisture content of more than 10% under a set temperature, gas environment and conditions higher than normal pressure, and restoring to normal pressure after treatment; the set gas is composed of oxygen and non-oxidizing gas, wherein the oxygen partial pressure accounts for 0% to 50% of the total pressure, and the non-oxidizing gas partial pressure accounts for 50% to 100% of the total pressure; the treatment temperature is 20 to 150°C. The method for improving tobacco quality of the present invention, on the basis of traditional tobacco treatment only involving temperature and moisture content, expands the production factors of pressure and oxidizing atmosphere, utilizes the adjustable pressure characteristics of the set gas and controls the oxygen content in the set gas, effectively improves the directional regulation ability of the endogenous browning reaction of tobacco, thereby achieving the purpose of improving the quality of medium and low quality tobacco.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco processing, and particularly relates to a method for improving tobacco quality. Background Art

[0002] Due to differences in varieties, soil, climate and cultivation measures, tobacco raw materials inevitably have quality differences, and even have obvious quality defects such as weak aroma, heavy smell and poor comfort. For cigarette industrial enterprises, these quality defective tobaccos squeeze out the raw material procurement quota, making it difficult to use them in cigarette products, and become a heavy burden. Improving the quality of medium and low-quality tobacco is of great value and significance.

[0003] The content of endogenous components and their relative proportions are the main factors that determine the quality of tobacco. Carotenoids, pyrocatechol-1-anes, lysines and browning reaction products are the four main flavor components of tobacco. Among them, the browning reaction products are not only affected by the content and proportion of endogenous sugars, nitrogen and other components in tobacco, but also by factors such as processing temperature and moisture content. By adjusting important processing parameters, the browning reaction products can be changed under the premise that the main endogenous components of tobacco do not change much, which in turn has a significant impact on the quality of tobacco. The degree of change of other flavor components during the processing is much smaller than that of browning reaction products. Therefore, based on the browning reaction regulation technology, there is huge potential and space to improve the quality of medium and low-quality tobacco.

[0004] In the production practices of tobacco blending, aging and processing, temperature and moisture content are the main controlling factors. The tobacco industry has formulated corresponding process specifications and clarified the temperature and moisture content ranges of the corresponding processes.

[0005] In order to process tobacco with quality defects or improve quality requirements, some researchers have made appropriate improvements and adjustments based on traditional processes. For example, the Chinese patent with invention announcement number CN103315375B discloses a redrying method for improving the quality of redrying tobacco leaves, which achieves quality improvement by reducing the redrying temperature and the speed of the mesh belt conveying the tobacco material, namely the so-called "low temperature slow baking". The Chinese patent with invention announcement number CN103300465B discloses a process for processing low-quality flue-cured tobacco leaves, specifically the processing time in the baking dryer is 10-12 minutes, which is higher than the 5 minutes required for conventional baking. This type of technology mainly achieves the purpose of improving tobacco quality by extending the wet heat treatment time of tobacco, but because the control factors do not exceed the traditional temperature and moisture content, the extension of the treatment time mainly amplifies the differences in the kinetics of the endogenous browning reaction of tobacco, and it is difficult to control the thermodynamic pathway of the browning reaction, and the degree of quality improvement is limited. The Chinese patent application with the invention publication number CN110786541A discloses a method for removing impurities and improving tobacco leaf quality by using a negative pressure regulation method. The tobacco leaves are treated under the conditions of a vacuum degree of 0.010-0.098MPa and a treatment time of 2-60 minutes, which can effectively remove impurities from the tobacco leaves. The patent application introduces a new regulation factor, pressure, but the negative pressure treatment inevitably causes the loss of volatile aroma components while removing impurities. Therefore, the development of a technical solution that meets the needs of large-scale and intensive production of the cigarette industry and comprehensively improves the quality of medium and low-quality tobacco has become a technical problem that needs to be solved in this field. Summary of the invention

[0006] The object of the present invention is to provide a method for improving tobacco quality, which can comprehensively improve the aroma index and sensory evaluation indexes such as comfort (irritation, dryness, aftertaste) of tobacco raw materials.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for improving tobacco quality comprises the following steps: treating tobacco materials with a moisture content of more than 10% under a set temperature, a gas environment and a condition higher than normal pressure, and restoring the tobacco materials to normal pressure after the treatment; the set gas is composed of oxygen and non-oxidizing gas, wherein the oxygen partial pressure accounts for 0% to 50% of the total pressure, and the non-oxidizing gas partial pressure accounts for 50% to 100% of the total pressure; and the treatment temperature is 20 to 150°C.

[0009] The method for improving tobacco quality of the present invention expands the factors of pressure and oxidative atmosphere on the basis of traditional tobacco processing which only involves temperature and moisture content, and utilizes the adjustable pressure characteristics of the set gas and controls the oxygen content in the set gas to effectively improve the directional regulation capability of the endogenous browning reaction of tobacco, thereby achieving the purpose of improving the quality of medium and low quality tobacco.

[0010] The method of the present invention can not only improve various qualities of tobacco after storage and aging, but also improve the sensory indexes of tobacco after redrying.

[0011] Furthermore, the partial pressure of the non-oxidizing gas accounts for 75% to 100% of the total pressure.

[0012] Furthermore, the set gas is air, or the non-oxidizing gas is one or any combination of nitrogen, carbon dioxide, hydrogen, and helium. The gas used in the present invention is not only easy to obtain, but also has a suitable price.

[0013] Furthermore, the non-oxidizing gas is nitrogen and / or carbon dioxide. Still further, the non-oxidizing gas is nitrogen.

[0014] Furthermore, the oxygen has no odor and a purity of not less than 90%.

[0015] Furthermore, the non-oxidizing gas has no odor and a purity of not less than 90%.

[0016] Furthermore, the setting gas is compressed air.

[0017] Furthermore, the compressed air refers to natural air compressed by external force and having a pressure higher than 0.1 MPa.

[0018] Furthermore, the compressed air is dehydrated and has no odor.

[0019] Further, the pressure higher than normal pressure is not more than 10.0 MPa. Further, the pressure higher than normal pressure is 0.2 to 6.0 MPa. Further, the pressure higher than normal pressure is 0.3 to 1.5 MPa.

[0020] Furthermore, the moisture content is 10% to 50%. Furthermore, the moisture content is 12% to 40%.

[0021] Furthermore, the treatment temperature is 40-100° C. The processing conditions such as pressure and temperature of the present invention are relatively mild and can be easily applied in the production of cigarette industry.

[0022] Furthermore, the treatment time is 1 to 120 minutes. Furthermore, the treatment time is 5 to 90 minutes.

[0023] Furthermore, the treatment is carried out in a closed container.

[0024] Furthermore, before the tobacco material with a moisture content of more than 10% is treated in a set gas environment and under conditions higher than normal pressure, the air in the sealed container is evacuated with the set gas.

[0025] Furthermore, before the tobacco material with a moisture content of more than 10% is treated in a set gas environment and under a condition of higher than normal pressure, the reactor is preheated.

[0026] Furthermore, the tobacco material is one or any combination of tobacco leaves, tobacco flakes, shredded tobacco, short stems, stem flakes, shredded stems, and reconstituted tobacco leaves.

[0027] Furthermore, for the light-flavor tobacco material, the moisture content is controlled to be no more than 20%, the non-oxidizing gas partial pressure in the set gas accounts for 80% to 100% of the total pressure, the total pressure is not less than 0.6 MPa, the treatment temperature is 30 to 60°C, and the treatment time is more than 30 minutes. The light-flavor tobacco material includes tobacco produced in Yunnan, western Sichuan, Fujian and other places.

[0028] Furthermore, for the strong-flavor tobacco material, the moisture content is controlled to be greater than 18%, the non-oxidizing gas partial pressure in the set gas accounts for 50% to 79% of the total pressure, the total pressure is not less than 0.2 MPa, the treatment temperature is 40 to 150°C, and the treatment time is 5 to 30 minutes. The strong-flavor tobacco material includes tobacco produced in the whole territory of Henan and some production areas in southern Hunan, Shandong, Anhui, Guangdong, Guangxi and other places.

[0029] Furthermore, for the intermediate-flavor tobacco material, the moisture content is controlled between 15% and 30%, the non-oxidizing gas partial pressure in the set gas accounts for 70% to 100% of the total pressure, the total pressure is not less than 0.4 MPa, the treatment temperature is 40 to 100° C., and the treatment time is 5 to 30 minutes. The intermediate-flavor tobacco material includes tobacco produced in other production areas in China except for the light-flavor and strong-flavor tobaccos.

[0030] Furthermore, for tobacco stems, the moisture content is controlled to be not less than 30%, the non-oxidizing gas partial pressure in the set gas accounts for 50% to 79% of the total pressure, the total pressure is not less than 0.8 MPa, the processing temperature is 60 to 150°C, and the processing time is 5 to 30 minutes.

[0031] Furthermore, after the tobacco material with a moisture content of more than 10% is treated under a set gas environment and a condition higher than normal pressure, the tobacco material is dried to obtain a tobacco sample with a moisture content of 11% to 13%.

[0032] A large number of browning reaction model tests show that factors such as temperature, moisture, pH, pressure, and oxidative atmosphere will have a significant impact on the reaction products. Based on the temperature and moisture content involved in traditional tobacco processing, the present invention increases the factors for regulating the endogenous browning reaction of tobacco to 4 in combination with the actual production situation, and the number of process control factors and level combinations is significantly increased, which effectively improves the directional control ability of the endogenous browning reaction of tobacco, and is feasible in the production of cigarette industry. The overall quality of tobacco materials treated by the present invention is significantly improved, including aroma quality, aroma quantity, impurities and comfort (irritation, dryness, aftertaste), etc. The sensory evaluation indexes of some low-quality tobacco quality can be improved by two levels. DETAILED DESCRIPTION

[0033] The processing method of pressurized gas treated tobacco comprises the following steps:

[0034] Step (1): adding tobacco materials with a certain moisture content into a reactor preheated to a certain temperature, sealing the reactor, introducing pressurized gas into the reactor, and exhausting the reactor three times;

[0035] Step (2): close the exhaust valve, open the air inlet valve, introduce pressurized gas into the reactor, and keep the air inlet valve open and the reactor temperature in step (1) for a certain period of time;

[0036] Step (3): close the air inlet valve, slowly open the exhaust valve, open the reactor after the pressure in the reactor drops to normal pressure, and take out the tobacco material;

[0037] Step (4): Perform subsequent processing such as shredding and drying according to the tobacco material morphology and moisture content requirements, and finally prepare sensory evaluation samples according to conventional methods.

[0038] The present invention is further described below in conjunction with the following examples: The oxygen and non-oxidizing gas used in the examples of the present invention are both odorless and have a purity of not less than 90%.

[0039] 1. Embodiment of the method for improving tobacco quality

[0040] Example 1

[0041] The method for improving tobacco quality of this embodiment comprises the following steps:

[0042] (1) Set the reactor heating temperature to 40°C and maintain it for 10 minutes after reaching the set temperature.

[0043] (2) Weigh 50 g of redried tobacco flakes (2019 Yunnan Yuxi C3F, moisture content 12%), spray 2.38 g of water (moisture content 16%) and place in a preheated reactor. Close the reactor, open the air inlet valve to introduce pressurized nitrogen, close the air inlet valve, open the exhaust valve to exhaust the gas, and repeat the above exhaust steps 3 times.

[0044] (3) Close the exhaust valve and introduce nitrogen into the reactor, maintain the nitrogen pressure at 1.0 MPa and the reactor temperature at 40°C, and treat the tobacco flakes for 80 minutes.

[0045] (4) Close the air inlet valve and slowly open the exhaust valve. After 15 seconds, when the pressure in the kettle drops to normal pressure, take out the tobacco slices, cut them into shreds, and adjust the moisture content of the shredded tobacco to about 12% in a 120° C. oven to obtain processed sample S1.

[0046] Example 2

[0047] The method for improving tobacco quality of this embodiment comprises the following steps:

[0048] (1) Set the reactor heating temperature to 60°C and maintain it for 10 minutes after reaching the set temperature.

[0049] (2) Oxygen and nitrogen are introduced into the gas premixing tank respectively to obtain pressurized gas with an oxygen partial pressure of 0.2MPa, a nitrogen partial pressure of 0.6MPa, and a total pressure of 0.8MPa. Weigh 50g of tobacco cut into pieces (2017 Henan Pingdingshan C4F, moisture content 12%) that has been naturally aged for 2 years after redrying, spray 7.89g of water (moisture content 24%) and put it into the preheated reactor. Close the reactor, open the air inlet valve to introduce the above-mentioned pressurized gas, close the air inlet valve, open the exhaust valve to exhaust the gas, and repeat the above-mentioned emptying step 3 times.

[0050] (3) Close the exhaust valve and introduce pressurized gas into the reactor, maintain the pressurized gas pressure at 0.8 MPa and the reactor temperature at 60°C, and treat the tobacco for 20 minutes.

[0051] (4) Close the air inlet valve and slowly open the exhaust valve. After 15 seconds, take out the tobacco after the pressure in the kettle drops to normal pressure, and adjust the moisture content of the tobacco to about 12% in a 120° C. oven to obtain treated sample S2.

[0052] Example 3

[0053] The method for improving tobacco quality of this embodiment comprises the following steps:

[0054] (1) Set the reactor heating temperature to 48°C and maintain it for 10 minutes after reaching the set temperature.

[0055] (2) Oxygen and nitrogen are introduced into the gas premixing tank respectively to obtain pressurized gas with an oxygen partial pressure of 0.1 MPa, a nitrogen partial pressure of 1.4 MPa, and a total pressure of 1.5 MPa. Weigh 50 g of redried tobacco flakes (2019 Guizhou Bijie C3F, moisture content 12%), spray 3.66 g of water (moisture content 18%) and put it into the preheated reactor. Close the reactor, open the air inlet valve to introduce pressurized gas, close the air inlet valve, open the exhaust valve to exhaust the gas, and repeat the above exhaust steps 3 times.

[0056] (3) Close the exhaust valve and introduce nitrogen into the reactor, maintain the above oxygen and nitrogen mixed gas pressure at 1.5 MPa and the reactor temperature at 48°C, and treat the tobacco leaves for 30 minutes.

[0057] (4) Close the air inlet valve and slowly open the exhaust valve. After 15 seconds, when the pressure in the kettle drops to normal pressure, take out the tobacco slices, cut them into shreds, and adjust the moisture content of the shredded tobacco to about 12% in a 120° C. oven to obtain processed sample S3.

[0058] Example 4

[0059] The method for improving tobacco quality of this embodiment comprises the following steps:

[0060] (1) Set the reactor heating temperature to 80°C and maintain it for 10 minutes after reaching the set temperature.

[0061] (2) Weigh 50 g of shredded stems (upper stems from Guizhou in 2017) with a moisture content of 33% and place them in a preheated reactor.

[0062] (3) Close the exhaust valve and introduce compressed air (dehydrated and odorless) into the reactor, maintain the compressed air pressure at 1.5 MPa and the reactor temperature at 80°C, and process the tobacco for 25 minutes.

[0063] (4) Close the air inlet valve and slowly open the exhaust valve. After 15 seconds, when the pressure in the kettle drops to normal pressure, take out the shredded tobacco and adjust the moisture content of the shredded tobacco to about 12% in a 120° C. oven to obtain processed sample S4.

[0064] 2. Comparison

[0065] Comparative Example 1

[0066] The method for improving the quality of tobacco in this comparative example comprises the following steps: weighing 50 g of tobacco leaves (2019 Yunnan Yuxi C3F, moisture content 12%), spraying 2.38 g of water (moisture content 16%), and sealing and storing at 25° C. for 1 hour. After shredding, the moisture content of the shredded tobacco is adjusted to about 12% in a 120° C. oven to obtain comparative sample R1 of Example 1.

[0067] Comparative Example 2

[0068] The method for improving the quality of tobacco in this comparative example comprises the following steps: weighing 50 g of tobacco shreds (C4F, Pingdingshan, Henan, 2017, moisture content 12%), spraying 7.89 g of water (moisture content 24%), and sealing and storing at 25° C. for 1 hour. Adjusting the moisture content of the tobacco shreds to about 12% in an oven at 120° C. to obtain comparative sample R2 of Example 2.

[0069] Comparative Example 3

[0070] The method for improving the quality of tobacco in this comparative example comprises the following steps: weighing 50 g of tobacco leaves (2019 Guizhou Bijie C3F, moisture content 12%), spraying 3.66 g of water (moisture content 18%), and sealing and storing at 25° C. for 1 hour. After shredding, the moisture content of the shredded tobacco is adjusted to about 12% in a 120° C. oven to obtain comparative sample R3 of Example 3.

[0071] Comparative Example 4

[0072] The method for improving the quality of tobacco in this comparative example comprises the following steps: weighing 50 g of cut stems (upper stems from Guizhou in 2017) with a moisture content of 33%, and sealing and storing them at 25° C. for 1 hour. Adjusting the moisture content of the cut stems to about 12% in an oven at 120° C. to obtain comparative sample R4 of Example 4.

[0073] 3. Experimental Examples

[0074] The samples in the embodiments and comparative examples were subjected to sensory evaluation according to the single-ingredient tobacco sensory evaluation method of the tobacco industry. The results are shown in Table 1.

[0075] Table 1 Sensory evaluation results (unit: points)

[0076]

[0077]

[0078] It can be seen from Table 1 that, compared with Comparative Examples 1 to 4, the aroma and comfort (irritation, dryness, aftertaste) indicators of the tobacco samples treated by Examples 1 to 4 are significantly improved, and the specific analysis is as follows:

[0079] The S1 sample is a light-fragrance tobacco product. Compared with the R1 sample, it has been treated with pressurized gas with lower moisture content, temperature, and lower oxygen content for a longer time. Without destroying the quality and flavor of the light-fragrance tobacco itself and maintaining its aroma and sweet aftertaste, it reduces the tobacco's odor and irritation, enhances the tobacco's permeability and aftertaste, and the overall sensory evaluation results are good.

[0080] The S2 sample is a strong-flavor tobacco product. Compared with the R2 sample, it has been treated at a higher temperature, a lower moisture content, a lower oxygen content, and a shorter time, and all evaluation indicators have been significantly improved. After tracking and evaluating the S2 sample, it was found that after one and a half years, the treated Henan Pingdingshan C4F-level tobacco material (i.e., the S2 sample) in Example 2 had a more obvious improvement in aroma indicators (aroma quality, impurities), and the sensory evaluation was improved by two levels.

[0081] The S3 sample is a tobacco product with an intermediate flavor. Compared with the R3 sample, it has been treated with pressurized gas with a certain moisture content, temperature, and oxygen content. Without destroying the quality and flavor of the intermediate flavor tobacco itself and maintaining its aroma and sweetness, it reduces the tobacco's odor and irritation, enhances the tobacco's permeability and aftertaste, and the overall sensory evaluation results are good.

[0082] The S4 sample is cut stems. In tobacco processing and production, cut stems are often mixed with tobacco leaves, which can not only reduce the consumption of tobacco leaves, but also reduce the tar content in tobacco products. The overall quality of cut stems is relatively poor. After being treated by the method of the present invention, the important indicators of the S4 sample, such as aroma quality and aroma quantity, are significantly improved compared with the R4 sample.

[0083] The above effects indicate that the present invention has a significant effect on regulating the endogenous browning reaction of tobacco, especially medium and low quality tobacco, and indicates that the present invention has good reliability and stability in improving the quality of tobacco; in addition, the present invention also designs appropriate processing schemes for tobacco materials of different qualities and different flavors, thereby realizing the classified processing technology of tobacco materials.

Claims

1. A method for improving tobacco quality, characterized in that: The following steps are involved: Treating tobacco materials with a moisture content of more than 10% under a set temperature, gas environment and higher than normal pressure, and returning to normal pressure after treatment; the set gas is composed of oxygen and non-oxidizing gas; For the light-flavor tobacco material, the moisture content is controlled to be no more than 20%, the non-oxidizing gas partial pressure in the set gas accounts for 80% to 100% of the total pressure, the total pressure is 0.6 to 1.0 MPa, the treatment temperature is 30 to 40°C, and the treatment time is 30 to 80 minutes; For strong-flavor tobacco materials, the moisture content is controlled to be greater than 18% and less than or equal to 24%, the non-oxidizing gas partial pressure in the set gas accounts for 75% to 79% of the total pressure, the total pressure is 0.2 to 0.8 MPa, the treatment temperature is 40 to 60°C, and the treatment time is 5 to 30 minutes; For the intermediate flavor tobacco material, the moisture content is controlled between 15% and 30%. In the set gas, the non-oxidizing gas partial pressure accounts for 70% to 93.3% of the total pressure, the total pressure is 0.4 to 1.5 MPa, the treatment temperature is 40 to 48° C., and the treatment time is 5 to 30 minutes.

2. The method for improving tobacco quality according to claim 1, characterized in that: The set gas is air, or the non-oxidizing gas is one or any combination of nitrogen, carbon dioxide, hydrogen, and helium.

3. The method for improving tobacco quality according to claim 1 or 2, characterized in that: The tobacco material is one or any combination of tobacco, sheet tobacco and shredded tobacco.

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