Cigar tobacco core tobacco circulation gradient fermentation method

Abstract

The application discloses a kind of cigar tobacco stem tobacco circulation gradient fermentation methods, first tobacco is rehydrated, then fermentation is carried out in three gradients, each gradient controls corresponding enzyme activity and enzyme solution dosage, and in page sprays enzyme solution and petiole is immersed in enzyme solution, and control temperature and humidity gradient rises, wherein the first gradient is carried out fermentation to tobacco using pectinase aqueous solution, the second gradient is carried out fermentation to tobacco using cellulase aqueous solution, the third gradient is carried out fermentation to tobacco using protease aqueous solution, after three gradient fermentation is completed, tobacco is carried out moisture balance, natural mellowing.After the tobacco fermented by the above method, the scores of aroma characteristics, smoke characteristics, combustion and ash color are all improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cigar tobacco production, and particularly relates to a fermentation method for a gradient cycle of cigar tobacco core. BACKGROUND

[0002] In the production of cigar tobacco, the quality of raw materials is not only affected by the techniques such as variety, cultivation and curing, but also by fermentation techniques. Fermentation is a more critical link for improving the quality of cigar tobacco. The use of appropriate fermentation processes can further degrade macromolecular substances such as sugars and proteins in tobacco to produce aroma precursor substances such as organic acids and volatile carbonyl compounds, thereby reducing the green and miscellaneous smell of tobacco, reducing the irritability, making the aroma more prominent, the smoke more mellow, and the oil more abundant. It is the technical core of cigar tobacco production.

[0003] The temperature and humidity of the environment are key factors affecting various biochemical reactions inside the tobacco during the fermentation process. The chemical composition of tobacco is very complex, and the optimal temperature for the degradation of various aroma precursors to small molecule aroma substances is not the same. For example, some sugars and nitrogen-containing compounds in tobacco are more obviously affected by temperature, while environmental humidity has a greater contribution to neutral flavor substances. However, in the current fermentation process of cigar tobacco, constant temperature fermentation is usually used, so the effect on improving the quality of tobacco is not obvious enough. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a fermentation method for cigar tobacco core, which uses different gradients of temperature and humidity to cycle ferment the tobacco according to its own characteristics, and applies different enzymes to assist fermentation, thereby degrading and converting macromolecular substances such as pectin, cellulose and protein in tobacco that are not conducive to smoking, reducing the smell and irritability of tobacco, improving the richness of aroma and smoking taste, and ultimately improving the quality and usability of tobacco.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] A gradient cycle fermentation method for cigar tobacco core, comprising the following steps:

[0007] (1) Tobacco moisture regain

[0008] The tobacco core to be fermented is placed in a temperature of 45℃ and a humidity of 85% for moisture regain;

[0009] (2) Gradient one fermentation

[0010] The pectinase is dissolved in water to obtain a pectinase aqueous solution, the activity of the pectinase in the aqueous solution is 1000-1500 U / mL, then the pectinase aqueous solution is uniformly sprayed on the tobacco leaves according to the weight ratio of the pectinase aqueous solution to the moisture-regulated tobacco leaves of 1:20-25, after that, the tobacco stems are immersed in the enzyme solution container prepared in step (2), and fermentation is carried out under the conditions of temperature 30℃ and humidity 75% for 1-2 days, and then the tobacco leaves are ready for use;

[0011] (3) Gradient secondary fermentation

[0012] The cellulase is dissolved in water to obtain a cellulase aqueous solution, the activity of the cellulase in the aqueous solution is 2000-2500 U / mL, then the cellulase aqueous solution is uniformly sprayed on the tobacco leaves prepared in step (2) according to the weight ratio of the cellulase aqueous solution to the moisture-regulated tobacco leaves of 1:15-20, after that, the tobacco stems are immersed in the enzyme solution container prepared in step (3), and fermentation is carried out under the conditions of temperature 40℃ and humidity 80% for 1-2 days, and then the tobacco leaves are ready for use;

[0013] (4) Gradient tertiary fermentation

[0014] The protease is dissolved in water to obtain a protease aqueous solution, the activity of the protease in the aqueous solution is 1500-2000 U / mL, then the protease aqueous solution is uniformly sprayed on the tobacco leaves prepared in step (3) according to the weight ratio of the protease aqueous solution to the moisture-regulated tobacco leaves of 1:25-30, after that, the tobacco stems are immersed in the enzyme solution container prepared in step (4), and fermentation is carried out under the conditions of temperature 55℃ and humidity 90% for 7-9 days, after the fermentation period, steps (2)-(4) are repeated for 1-3 times, and then the fermentation is ended;

[0015] (5) Natural mellowing

[0016] The tobacco leaves after the fermentation in step (4) are moisture-balanced, then stacked, and then placed under the conditions of temperature 25℃ and humidity 65% for natural mellowing for 60-90 days.

[0017] Specifically, in step (1), the moisture-regulation time of the tobacco leaves is 24 hours;

[0018] Specifically, in steps (2), (3) and (4), the water is sterile deionized water;

[0019] Specifically, in steps (2), (3) and (4), the depth of the tobacco stems immersed in the enzyme solution is limited to not touching the tobacco leaves;

[0020] Specifically, in steps (2), (3) and (4), after the enzyme solution is sprayed on the surface of the tobacco leaves and before the tobacco stems are immersed in the enzyme solution, the tobacco leaves are first placed at room temperature for 12 hours.

[0021] Specifically, in step (2), the activity of pectinase in the aqueous solution is 1000-1300 U / mL;

[0022] Specifically, in step (3), the activity of cellulase in the aqueous solution is 2000-2300 U / mL;

[0023] Specifically, in step (4), the activity of protease in the aqueous solution is 1500-1800 U / mL;

[0024] Specifically, in step (5), the moisture content of the tobacco leaves after moisture balance is 15-17%.

[0025] Specifically, in step (5), the weight of the pile is 100-150 kg, and the pile is turned over every 30 days.

[0026] Compared with the prior art, the present application has at least the following beneficial effects:

[0027] (1) The use of the temperature and humidity gradient rising method is more conducive to promoting various biochemical reactions in the tobacco leaves, and the use of different enzyme preparations in different temperature and humidity intervals can degrade and convert the macromolecular substances such as cellulose, pectin and protein in the tobacco leaves into small molecular aroma substances; (2) The use of the tobacco leaf surface spraying and tobacco leaf stem dipping methods is more conducive to transporting the enzymes to the cell interior through the vascular tissue in the main vein, which can effectively degrade the macromolecular substances in the tobacco leaf cells; (3) The use of the temperature gradient from low temperature to high temperature is more conducive to opening the stomata on the surface of the tobacco leaves in the early stage, and absorbing moisture, thereby laying a foundation for the next biochemical reaction; (4) The number of cycles of fermentation can be selected according to the differences in the quality of the incoming materials, so as to ensure that the loss of aroma of the tobacco leaves due to excessive fermentation or the presence of heavy odor or greater irritation in the tobacco leaves due to insufficient fermentation time. In summary, the scores of the tobacco leaves fermented by the above method in terms of aroma characteristics, smoke characteristics, combustibility and ash color are all improved. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0029] The pectinase, cellulase and protease mentioned in the following examples and comparative examples are commercially available, and the activity of pectinase is 30000 U / g, the activity of cellulase is 20000 U / g, and the activity of protease is 100000 U / g.

[0030] Example 1

[0031] (1) Tobacco leaf conditioning: prepare 150 kg of the upper leaves of the third grade of the De Xue series tobacco core, and place the tobacco leaves in a humidity and temperature condition of 45 °C and 85% for 24 h for conditioning;

[0032] (2) Gradient one fermentation: dissolve pectinase in sterile deionized water to prepare an enzyme solution of a certain weight, so that the activity of pectinase in the solution is 1500 U / mL, evenly spray 7.5 kg of the pectinase solution on the tobacco leaves, and then stand for 12 h. After standing, immerse the tobacco stems in a container containing the pectinase solution to a depth of 1 cm, and then place the container in a humidity and temperature condition of 30 °C and 75% for 2 d for fermentation;

[0033] (3) Gradient two fermentation: dissolve cellulase in sterile deionized water to prepare an enzyme solution of a certain amount, so that the activity of cellulase in the solution is 2500 U / mL, evenly spray 10 kg of the cellulase solution on the tobacco leaves, and then stand for 12 h. After standing, immerse the tobacco stems in a container containing the cellulase solution to a depth of 1 cm, and then place the container in a humidity and temperature condition of 40 °C and 80% for 2 d for fermentation;

[0034] (4) Gradient three fermentation: dissolve protease in sterile deionized water to prepare an enzyme solution of a certain amount, so that the activity of protease in the solution is 2000 U / mL, evenly spray 6 kg of the protease solution on the tobacco leaves, and then stand for 12 h. After standing, immerse the tobacco stems in a container containing the protease solution to a depth of 1 cm, and then place the container in a humidity and temperature condition of 55 °C and 90% for 9 d for fermentation. After the fermentation period, repeat steps (2)-(4) three times, and then end the fermentation;

[0035] (5) Natural aging: after the fermentation of step (4) is completed, balance the moisture content of the tobacco leaves to 17%, and then stack the tobacco leaves (the weight of the stack is 100 kg) and place the stack in a humidity and temperature condition of 25 °C and 65% for 90 d of natural aging. Flip the stack every 30 d.

[0036] Example 2

[0037] (1) Tobacco leaf conditioning: prepare 150 kg of the upper leaves of the third grade of the De Xue series tobacco core, and place the tobacco leaves in a humidity and temperature condition of 45 °C and 85% for 24 h for conditioning;

[0038] (2) Gradient one fermentation: dissolve pectinase in sterile deionized water to prepare an enzyme solution of a certain weight, so that the activity of pectinase in the solution is 1000 U / mL, evenly spray 6 kg of the pectinase solution on the tobacco leaves, and then stand for 12 h. After standing, immerse the tobacco stems in a container containing the pectinase solution to a depth of 0.5 cm, and then place the container in a humidity and temperature condition of 30 °C and 75% for 1 d for fermentation;

[0039] (3) Gradient two fermentation: cellulase is dissolved in sterile deionized water to make a certain amount of enzyme solution, the activity of cellulase in the solution is 2000 U / mL, 7.5 kg of cellulase solution is weighed and uniformly sprayed on the tobacco leaves, and then the tobacco leaves are placed for 12 h. After the end of the standing, the tobacco stems are immersed in a container containing the cellulase solution, the immersion depth is 0.5 cm, and then the fermentation is carried out at 40°C and 80% humidity, and the period is 1 d;

[0040] (4) Gradient three fermentation: protease is dissolved in sterile deionized water to make a certain amount of enzyme solution, the activity of protease in the solution is 1500 U / mL, 5 kg of protease solution is weighed and uniformly sprayed on the tobacco leaves, and then the tobacco leaves are placed for 12 h. After the end of the standing, the tobacco stems are immersed in a container containing the protease solution, the immersion depth is 0.5 cm, and then the fermentation is carried out at 55°C and 90% humidity, and the period is 7 d. After the fermentation period, the steps (2)-(4) are repeated once, and then the fermentation is ended;

[0041] (5) Natural aging: the tobacco leaves subjected to the fermentation in step (4) are subjected to moisture balance, the moisture content is controlled at 15%, and then the tobacco leaves are stacked (the weight of the stack is 100 kg) and subjected to natural aging at 25°C and 65% humidity for 60 d, and the stack is turned over every 30 d.

[0042] Example 3

[0043] (1) Tobacco moisture regain: 150 kg of the upper leaves of the third grade of the De Xue series tobacco core are prepared, and the tobacco leaves are subjected to moisture regain at 45°C and 85% humidity for 24 h;

[0044] (2) Gradient one fermentation: pectinase is dissolved in sterile deionized water to make a certain amount of enzyme solution, the activity of pectinase in the solution is 1200 U / mL, 6.48 kg of pectinase solution is weighed and uniformly sprayed on the tobacco leaves, and then the tobacco leaves are placed for 12 h. After the end of the standing, the tobacco stems are immersed in a container containing the pectinase solution, the immersion depth is 1.2 cm, and then the fermentation is carried out at 30°C and 75% humidity, and the period is 1.5 d;

[0045] (3) Gradient two fermentation: cellulase is dissolved in sterile deionized water to make a certain amount of enzyme solution, the activity of cellulase in the solution is 2200 U / mL, 8.3 kg of cellulase solution is weighed and uniformly sprayed on the tobacco leaves, and then the tobacco leaves are placed for 12 h. After the end of the standing, the tobacco stems are immersed in a container containing the cellulase solution, the immersion depth is 1.2 cm, and then the fermentation is carried out at 40°C and 80% humidity, and the period is 1.5 d;

[0046] (4) Gradient three fermentation: dissolve the protease in sterile deionized water to prepare a certain amount of enzyme solution, so that the activity of the protease in the solution is 1700 U / mL, weigh 5.4 kg of the protease solution and uniformly spray the solution on the tobacco leaves, and then stand for 12 h, after the standing is completed, immerse the tobacco stems in a container containing the protease solution, the immersion depth is 1.2 cm, then place the container in a 55℃, 90% temperature and humidity environment for fermentation, the period is 8 days, after the fermentation period is reached, repeat steps (2)-(4) twice, and then end the fermentation;

[0047] (5) Natural mellowing: balance the moisture content of the tobacco leaves after the fermentation in step (4) is completed, so that the moisture content is controlled at 16%, then stack the tobacco leaves (the weight of the stack is 100 kg), and place the stack in a 25℃, 65% temperature and humidity environment for 75 days of natural mellowing, and turn the stack over every 30 days.

[0048] Comparative Example 1 (Comparative Example 1-1, Comparative Example 1-2, Comparative Example 1-3)

[0049] The present comparative example provides a constant temperature fermentation method for cigar tobacco leaves, and the specific steps are as follows:

[0050] (1) Tobacco moisture regain: prepare three groups of 150 kg of upper leaves of cigar cores in the De Xue series, and place the tobacco leaves in a 45℃, 85% temperature and humidity environment for moisture regain, and the time is 24 h.

[0051] (2) Tobacco fermentation: place the three groups of tobacco leaves to be fermented in step (1) in a 30℃, 75%, 40℃, 80%, and 55℃, 90% temperature and humidity environment for constant temperature and humidity fermentation, and the fermentation time of each group is 30 days.

[0052] The tobacco leaf groups treated by different temperature and humidity are respectively named as Comparative Example 1-1, Comparative Example 1-2, and Comparative Example 1-3.

[0053] Comparative Example 2

[0054] The present comparative example provides a composite enzyme fermentation method for cigar tobacco, and the specific steps are as follows,

[0055] (1) Tobacco moisture regain: prepare three groups of 150 kg of upper leaves of cigar cores in the De Xue series, and place the tobacco leaves in a 45℃, 85% temperature and humidity environment for moisture regain, and the time is 24 h.

[0056] (2) Preparation of composite enzyme solution: weigh a certain amount of protease, pectinase, and cellulase, and dissolve them in sterile deionized water to prepare a composite enzyme solution, so that the activity of the protease in the solution is 1700 U / mL, the activity of the pectinase is 1200 U / mL, and the activity of the cellulase is 2200 U / mL, and the solution is ready for use;

[0057] (3) Tobacco fermentation: 6.73 kg of the composite enzyme solution prepared in step (2) was evenly sprayed on the tobacco leaves, and then the tobacco leaves were left to stand for 12 h. After the standing, the tobacco leaves were immersed in a container containing the composite enzyme solution to a depth of 1.2 cm. Then, the tobacco leaves were placed in a 30℃, 75% humidity environment for fermentation for 1.5 d. 6.73 kg of the composite enzyme solution prepared in step (2) was evenly sprayed on the tobacco leaves, and then the tobacco leaves were left to stand for 12 h. After the standing, the tobacco leaves were immersed in a container containing the composite enzyme solution to a depth of 1.2 cm. Then, the tobacco leaves were placed in a 40℃, 80% humidity environment for fermentation for 1.5 d. 6.73 kg of the composite enzyme solution prepared in step (2) was evenly sprayed on the tobacco leaves, and then the tobacco leaves were left to stand for 12 h. After the standing, the tobacco leaves were immersed in a container containing the composite enzyme solution to a depth of 1.2 cm. Then, the tobacco leaves were placed in a 55℃, 90% humidity environment for fermentation for 8 d. After the fermentation, the fermentation was ended by repeating step (3) twice.

[0058] (4) Natural mellowing: The tobacco leaves subjected to the fermentation in step (3) were subjected to moisture balancing to control the moisture content at 16%. Then, the tobacco leaves were stacked (the weight of the stack was 100 kg) and placed in a 25℃, 65% humidity environment for natural mellowing for 75 d. The stack was turned over every 30 d.

[0059] The tobacco leaves of Example 1 to Example 3, Comparative Example 1 to Comparative Example 2, and the tobacco leaves without any treatment (blank group) were respectively evaluated in terms of seven items including aroma quality, aroma amount, offensive odor, irritation, aftertaste, ash color, and combustibility. The sensory evaluation results and scoring standards are shown in Table 2. Each item was scored in units of 0.5.

[0060] The aroma substances were measured by gas chromatography-mass spectrometry. The analysis process was as follows: 30 g of the treated sample was crushed and sieved through a 60-mesh sieve, and then distilled and extracted for 2.5 h using CH2Cl2 as the extraction agent. After the distillation, 1 mL of an internal standard was added to the cooled extraction liquid, and then anhydrous sodium sulfate was added and left to stand overnight. Then, the extraction liquid was concentrated to 1 mL and transferred to a chromatographic bottle for GC / MS detection. The aroma substance content is shown in Table 3.

[0061] Table 1 GC / MS analysis conditions

[0062]

[0063]

[0064] Table 2 Sensory evaluation results and scoring standards

[0065]

[0066]

[0067] Table 3: Flavor substance content (unit: pg / g)

[0068]

[0069]

[0070] "-" represents not detected

[0071] It can be seen from the comparative example 1 that, compared with the blank group, the aroma, offensive odor and irritability of the tobacco leaves are improved with the increase of the fermentation temperature in the constant temperature fermentation process.

[0072] It can be seen from the comparative example 2 that, compared with the blank group, the tobacco leaves fermented by the composite enzyme have obvious effects on aroma quality and irritability, but the effect is not as obvious as that of the examples, which should be due to the decomposition of pectinase and cellulase by the protease in the composite enzyme, resulting in the insignificant effect of the enzyme on the tobacco leaves. Through the gradient fermentation (example 1 to example 3) of the tobacco leaves, supplemented by different enzymes under different temperature and humidity conditions, the fermented tobacco leaves have more rich aroma, increased content of aroma substances, greatly reduced offensive odor, reduced irritability, more comfortable aftertaste, more rich tobacco aroma, fine and full smoke and comfortable aftertaste. The tobacco leaves fermented by the circulation gradient fermentation of the present application have obvious improvement in the scores of aroma characteristics, smoke characteristics, combustion and ash color.

[0073] Although the present application has been described herein with reference to the explanatory embodiments thereof, it should be understood that many other modifications and embodiments will occur to those skilled in the art which will fall within the principles and spirit of the disclosure. More particularly, many modifications and variations of the present subject combination arrangement can be made in the components and / or the arrangement thereof in keeping with its scope. Other uses will also become apparent to those skilled in the art.

Claims

1. A cyclic gradient fermentation method for cigar filler tobacco leaves, characterized in that, Includes the following steps: (1) Tobacco leaves rehydrate Place the eggplant core tobacco leaves to be fermented in a condition of 45℃ and 85% humidity for rehydration; (2) Gradient fermentation After dissolving pectinase in water, an aqueous solution of pectinase is obtained, with the activity of pectinase in the aqueous solution being 1000-1500 U / mL. Then, the aqueous solution of pectinase is evenly sprayed onto the tobacco leaves according to the weight ratio of the aqueous solution of pectinase to the rehydrated tobacco leaves of 1:20-25. After that, the petioles of the tobacco leaves are immersed in a container containing the enzyme solution prepared in step (2) and fermented for 1-2 days at a temperature of 30℃ and a humidity of 75%. After the fermentation is completed, the leaves are ready for use. (3) Gradient secondary fermentation Cellulase was dissolved in water to obtain an aqueous solution of cellulase, and the activity of cellulase in the aqueous solution was 2000-2500 U / mL. Then, the aqueous solution of cellulase was evenly sprayed onto the tobacco leaves prepared in step (2) according to the weight ratio of the aqueous solution of cellulase to the rehydrated tobacco leaves of 1:15-20. After that, the petioles of the tobacco leaves were immersed in a container containing the enzyme solution prepared in step (3) and fermented for 1-2 days at a temperature of 40℃ and a humidity of 80%. After the fermentation was completed, the leaves were put into use. (4) Gradient three-stage fermentation After dissolving the protease in water, an aqueous solution of the protease is obtained, and the activity of the protease in the aqueous solution is 1500-2000 U / mL. Then, the aqueous solution of the protease is evenly sprayed onto the tobacco leaves prepared in step (3) according to the weight ratio of the aqueous solution of the protease to the rehydrated tobacco leaves of 1:25-30. After that, the petioles of the tobacco leaves are immersed in a container containing the enzyme solution prepared in step (4) and fermented under the conditions of 55℃ and 90% humidity for 7-9 days. After the fermentation cycle is reached, steps (2)-(4) are repeated 1-3 times, and then the fermentation is ended. (5) Natural aging The tobacco leaves that have finished fermentation in step (4) are moisture balanced, then stacked and placed under conditions of 25°C and 65% humidity for natural aging for 60-90 days.

2. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In step (1), the rehydration time of the tobacco leaves is 24 hours.

3. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In steps (2), (3), and (4), the water is sterile deionized water.

4. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In steps (2), (3), and (4), the depth to which the tobacco leaf petiole is immersed in the enzyme solution is limited to not touching the tobacco leaf blade.

5. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In steps (2), (3), and (4), after the enzyme solution is sprayed onto the surface of the tobacco leaves and before the leaf petioles are immersed in the enzyme solution, the tobacco leaves are left to stand at room temperature for 12 hours.

6. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In step (2), the activity of pectinase in the aqueous solution is 1000-1300 U / mL.

7. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In step (3), the activity of cellulase in the aqueous solution is 2000-2300 U / mL.

8. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In step (4), the activity of the protease in the aqueous solution is 1500-1800 U / mL.

9. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In step (5), the moisture content of the tobacco leaves after moisture balance is 15-17%.

10. The cyclic gradient fermentation method for cigar filler tobacco leaves according to claim 1, characterized in that, In step (5), the weight of the stack is 100-150 kg, and the stack is turned over every 30 days.

Images