Extract of Tieguanyin withered green material and preparation method thereof, tobacco leaf composition and cigarette

Abstract

The present invention belongs to the field of tobacco products, and specifically relates to a method for preparing an extract of Tieguanyin cured product, comprising: performing monoclonal culture on yeast to obtain a culture with an OD600 of 0.1-3; applying the culture to Tieguanyin cured product, wherein the weight of the culture is 0.05%-2% of the weight of the Tieguanyin cured product, and fermenting at 25°C-55°C for 1-8 hours to obtain a fermentation product; performing steam distillation on the fermentation product, and collecting a distillate. The present invention also relates to an extract of Tieguanyin cured product, a tobacco leaf composition, and a cigarette. The content of various volatile aroma components in the extract of Tieguanyin cured product of the present invention is significantly increased, and the content of total volatile aroma components is significantly increased. Adding the extract of Tieguanyin cured product to cigarette shreds can significantly enhance the fragrance, floral, fruity, and sweet aroma characteristics of cigarettes, and improve the sensory quality of cigarettes when smoking.

Description

Technical Field

[0001] The invention belongs to the field of tobacco products, and in particular relates to a method for preparing an extract of a cured Tieguanyin tea, and also relates to the prepared extract of the cured Tieguanyin tea, a tobacco leaf composition and a cigarette. Background Art

[0002] Tieguanyin tea is a famous tea variety in Fujian, which includes the processing processes of picking, sun-drying, making green tea, killing green tea, wrapping and kneading, and drying. Killed Tieguanyin is a product made by picking fresh Tieguanyin tea through the processes of picking, sun-drying, making green tea and killing green tea. However, since the content of volatile aroma components in the killed Tieguanyin is very low, the existing method cannot fully extract and use the volatile aroma components in the killed Tieguanyin to make tobacco flavors. The content of volatile aroma components in the tobacco flavors made by extracting the killed Tieguanyin by the existing method is low, and the sensory quality of the tobacco flavors after adding the prepared tobacco flavors to cigarettes is poor.

[0003] Currently, there is an urgent need for a method for preparing tobacco flavor using Tieguanyin withered material, so as to increase the content of volatile aroma components in the tobacco flavor and improve the sensory quality of the tobacco flavor after being added to cigarettes. Summary of the invention

[0004] One of the purposes of the present invention is to provide a method for preparing an extract of Tieguanyin cured product, which increases the content of various volatile aroma components and the content of total volatile aroma components in the extract of Tieguanyin cured product, and adds the prepared Tieguanyin cured product extract to cigarette shreds, thereby improving the fragrance, fruity, floral, and sweet aroma characteristics and aroma quality of cigarettes, improving the aroma richness, delicate softness, and roundness of the smoke when the cigarette is smoked, increasing the smoke concentration, reducing the impurities in the smoke, and slightly improving the smoking power, thereby improving the overall sensory quality of the cigarette. Another purpose of the present invention is to provide a tobacco leaf composition comprising the extract of the above-mentioned Tieguanyin cured product, and a cigarette comprising the extract of the above-mentioned Tieguanyin cured product or the tobacco leaf composition.

[0005] To achieve the above object, the first aspect of the present invention provides a method for preparing an extract of Tieguanyin cured product, comprising the following steps:

[0006] (1) culturing the yeast as a single clone to obtain a culture having an OD600 of 0.1-3 (e.g., 1, 1.5, 2, 2.5);

[0007] (2) applying the culture to the cured Tieguanyin material, wherein the weight of the culture is 0.05%-2% (preferably 0.05%-1.5%, such as 0.1%, 0.2%, 0.5%, 1%) of the weight of the cured Tieguanyin material, and fermenting at 25° C.-55° C. (preferably 30° C.-55° C., such as 30° C., 35° C., 45° C., 50° C.) for 1-8 hours (preferably 1-6 hours, such as 2, 3, 4, 5, 6 hours) to obtain a fermentation product;

[0008] (3) subjecting the fermentation product to steam distillation and collecting the distillate.

[0009] In any embodiment of the first aspect of the present invention, in step (1), the monoclonal culture comprises the following steps:

[0010] 1) streaking the yeast on a solid culture medium, and inverting and culturing at 25°C-35°C (preferably 28°C-32°C, such as 29°C, 30°C, 31°C) for 20-30 hours (e.g., 22, 24, 26, 28 hours);

[0011] 2) Pick a single colony with a clear edge boundary and inoculate it into a liquid culture medium, and culture it at 25°C-35°C (preferably 28°C-32°C, such as 29°C, 30°C, 31°C) with shaking for 2-10 hours (e.g., 3, 4, 5, 6, 7, 8, 9 hours).

[0012] In any embodiment of the first aspect of the present invention, in step (1), it is characterized by one or more of the following:

[0013] (A) The yeast is Saccharomyces cerevisiae purchased from China Industrial Microbiological Culture Collection Center with strain collection number CICC 1946;

[0014] (B) the yeast is provided in the form of a bacterial suspension;

[0015] Optionally, the content of live yeast in the bacterial suspension is 10 7 -10 10 CFU / mL, for example 1×10 8 CFU / mL, 1×10 9 CFU / mL, 2×10 9 CFU / mL;

[0016] Optionally, the bacterial suspension is obtained by mixing yeast with purified water;

[0017] (C) the solid culture medium is selected from one or more of a yeast extract peptone glucose solid culture medium, a potato solid culture medium and a malt extract solid culture medium;

[0018] (D) the liquid culture medium is selected from one or more of a yeast extract peptone glucose liquid culture medium, a potato liquid culture medium and a malt extract liquid culture medium;

[0019] (E) performing shaking culture at a shaking speed of 100-200 r / min (e.g., 120, 150, 180, 190 r / min); optionally, performing shaking culture in a shaking incubator.

[0020] The culture media in items (C) and (D) above are commonly used culture media.

[0021] In any embodiment of the first aspect of the present invention, in step (3), the steam distillation is distillation in water.

[0022] In any embodiment of the first aspect of the present invention, in step (3), the weight of water used in the water distillation is 10-30 times the weight of the fermentation product, such as 15 times, 20 times, or 25 times.

[0023] In any embodiment of the first aspect of the present invention, the method further comprises:

[0024] (4) Concentrating the distillate to reduce the water content.

[0025] In any embodiment of the first aspect of the present invention, in step (4), concentration is performed by reverse osmosis treatment.

[0026] In any embodiment of the first aspect of the present invention, in step (4), the membrane outlet pressure of the reverse osmosis treatment is 0.5-2.5 MPa (preferably 0.7-2.0 MPa), and the operating temperature is 15°C-35°C (preferably 20°C-30°C).

[0027] In any embodiment of the first aspect of the present invention, the method comprises one or more of the following:

[0028] (a) In step (2), before applying, the cured Tieguanyin is crushed and sieved, and the sieved material is collected; optionally, the sieve is sieved with a 40-60 mesh sieve (for example, a 50 mesh sieve);

[0029] (b) in step (2), the culture is applied by spraying or coating the culture on the surface of the Tieguanyin cured product;

[0030] (c) in step (3), before steam distillation, the fermentation product is sterilized; optionally, sterilized at 90°C-130°C (preferably 100°C-121°C, such as 100°C, 110°C, 121°C) for 10-30 minutes (preferably 10-20 minutes, such as 20 minutes);

[0031] (d) in step (3), the temperature of steam distillation is 90°C-120°C, preferably 100°C-120°C, for example 100°C, 110°C;

[0032] (e) In step (3), the steam distillation time is 1-6 hours, preferably 1-4 hours, for example 2, 3, 4, 5 hours.

[0033] In the present invention, the volatile component is a volatile aroma component.

[0034] The second aspect of the present invention provides an extract of Tieguanyin cured product, which is prepared by the method of the first aspect of the present invention;

[0035] Optionally, the extract of the Tieguanyin finished product is tobacco flavoring;

[0036] Optionally, tobacco flavoring is applied to tobacco shreds or tobacco leaves.

[0037] In any embodiment of the second aspect of the present invention, the extract of the cured Tieguanyin tea comprises one or more of the following:

[0038] The mass content of volatile alcohol components in the extract of the fixed Tieguanyin is greater than 30 μg / g, preferably greater than 32 μg / g;

[0039] The mass content of volatile ester components in the extract of the Tieguanyin cured product is greater than 3 μg / g;

[0040] The mass content of aldehyde volatile components in the extract of the Tieguanyin cured product is greater than 4 μg / g;

[0041] The mass content of volatile ketone components in the extract of the Tieguanyin cured product is greater than 2 μg / g;

[0042] The mass content of terpene volatile components in the extract of the Tieguanyin cured product is greater than 1 μg / g;

[0043] The total mass content of volatile components in the extract of the fixed Tieguanyin is greater than 40 μg / g, preferably greater than 42 μg / g;

[0044] The mass content of indole in the extract of the Tieguanyin cured product is greater than 1.2 μg / g;

[0045] The mass content of linalool in the extract of the fixed Tieguanyin is greater than 6 μg / g, preferably greater than 6.5 μg / g;

[0046] The mass content of geraniol in the extract of the fixed Tieguanyin is greater than 0.95 μg / g, preferably greater than 1 μg / g.

[0047] The third aspect of the present invention provides a tobacco leaf composition comprising an extract of the withered Tieguanyin tea according to the second aspect of the present invention.

[0048] The fourth aspect of the present invention provides a cigarette comprising an extract of the withered Tieguanyin tea of ​​the second aspect of the present invention or a tobacco leaf composition of the third aspect of the present invention.

[0049] In the present invention, unless otherwise specified:

[0050] The term "Iron Guanyin Killed Green Product" refers to the product made from freshly picked Tieguanyin tea through the processes of picking, sun drying, making green and killing green.

[0051] The term "OD600" is the absorbance value measured when the wavelength is set to 600nm. It is a standard indicator for tracking the density of microorganisms in liquid culture and is usually used to indicate bacterial density.

[0052] The term "streak inoculation" is a commonly used inoculation method. Inoculation is achieved by moving the inoculated substance back and forth on the surface of the solid culture medium. Commonly used inoculation tools include inoculation loops, inoculation needles, etc.

[0053] The term "microbial suspension" refers to a suspension containing microorganisms.

[0054] Beneficial effects achieved by the present invention:

[0055] The method of the invention prepares an extract of the cured Tieguanyin tea, and increases the content of various volatile aroma components and the content of total volatile aroma components in the extract of the cured Tieguanyin tea.

[0056] The extract of the withered Tieguanyin prepared by the method of the present invention is added to cigarette shreds, which improves the fragrance characteristics and fragrance quality of the cigarette, such as fresh fragrance, fruity fragrance, floral fragrance, and sweet fragrance, and improves the fragrance richness, delicate softness, and roundness of the smoke when the cigarette is smoked, increases the smoke concentration, reduces the impurities in the smoke, slightly improves the suction strength, and improves the overall sensory quality of the cigarette. DETAILED DESCRIPTION

[0057] The embodiments of the present invention will be described clearly and completely below in conjunction with the examples. Obviously, the described examples are only some examples of the present invention, rather than all examples. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the examples in the present invention, all other examples obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0058] The materials and measurement procedures used in the embodiments and comparative examples are as follows:

[0059] Tieguanyin withered tea: purchased from Anxi Jizhe Tea Co., Ltd.

[0060] Saccharomyces cerevisiae: Latin name Saccharomyces cerevisiae, purchased from China Industrial Culture Collection Center (CICC), strain collection number is CICC 1946;

[0061] Yeast extract peptone dextrose (YPD) solid medium: purchased from Shenggong Biotechnology (Shanghai) Co., Ltd.;

[0062] Yeast extract peptone dextrose (YPD) liquid medium: purchased from Shenggong Biotechnology (Shanghai) Co., Ltd.;

[0063] The determination method of OD600: The first step is to set the wavelength to 600nm in the instrument photometer; the second step is to put the culture medium without bacterial solution as a blank sample and adjust it to zero; the third step is to put the sample in to display the A value (absorbance) of the sample, which is OD600.

[0064] Example 1

[0065] (1) crushing the finished Tieguanyin tea by a pulverizer, passing it through a 50-mesh sieve, and collecting the sieved material;

[0066] (2) Take the live bacteria content of 5×10 9 CFU / g of brewer's yeast was dissolved in pure water to prepare a viable bacterial content of 2×10 9 CFU / mL yeast liquid, pick the yeast liquid and streak it on yeast extract peptone dextrose (YPD) solid medium, invert and culture it in a 30℃ incubator for 24 hours, pick a single colony with clear edge boundaries and inoculate it on YPD liquid medium, and culture it in a 30℃ shaking incubator for 6 hours at a shaking speed of 180r / min to obtain a monoclonal culture with an OD600 of 2.0;

[0067] (3) spraying the culture obtained in step (2) onto the surface of the sieved material, the weight of the culture being 0.1% of the weight of the sieved material, and then fermenting in an incubator at 35° C. for 4 hours;

[0068] (4) sterilizing the fermentation product obtained in step (3) at 121° C. for 20 minutes, adding 20 times by weight of purified water to the sterilized fermentation product, and then heating it for steam distillation extraction at a distillation temperature of 100° C. for 2 hours, and condensing and collecting the distillate;

[0069] (5) The distillate is concentrated through a reverse osmosis membrane, the membrane pressure is 0.7-2.0 MPa, the operating temperature is 20°C-30°C, and the retentate is collected as the concentrate.

[0070] Example 2 to Example 4

[0071] In step (3), the weight of the culture was adjusted to 0.2%, 0.5% and 1.0% of the weight of the sieved material, respectively, and the rest was the same as in Example 1.

[0072] Example 5 to Example 8

[0073] In step (3), the incubator temperature was adjusted to 30° C., and the fermentation time was adjusted to 3 hours, 4 hours, 5 hours and 6 hours, respectively. The rest was the same as in Example 1.

[0074] Example 9 to Example 11

[0075] In step (3), the fermentation time was adjusted to 2 hours, and the temperature of the incubator was adjusted to 35° C., 45° C. and 50° C. respectively. The rest was the same as in Example 1.

[0076] Comparative Example 1 did not use monoclonal culture and fermentation

[0077] (1) crushing the finished Tieguanyin tea by a pulverizer, passing it through a 50-mesh sieve, and collecting the sieved material;

[0078] (2) sterilizing the sieved material at 121° C. for 20 minutes, adding 20 times by weight of purified water to the sterilized sieved material, and then heating to perform steam distillation extraction at a distillation temperature of 100° C. for 2 hours, and condensing and collecting the distillate;

[0079] (3) The distillate is concentrated and enriched through a reverse osmosis membrane, the membrane pressure is 0.7-2.0 MPa, the operating temperature is 20°C-30°C, and the retentate is collected as the concentrate.

[0080] Comparative Example 2 did not use monoclonal culture

[0081] (1) The same as step (1) of Example 5;

[0082] (2) Take the live bacteria content of 5×10 9 CFU / g of Saccharomyces cerevisiae was dissolved in pure water to prepare a yeast solution with an OD600 of 2.0;

[0083] (3) spraying the yeast solution obtained in step (2) onto the surface of the sieved material, wherein the weight of the yeast solution is 0.1% of the weight of the sieved material, and then fermenting in an incubator at 30° C. for 3 hours;

[0084] (4)-(5) are the same as steps (4)-(5) of Example 5.

[0085] Comparative Example 3 Fermentation time is different

[0086] In step (3), the fermentation time is adjusted to 3 days, and the rest is the same as Example 11.

[0087] Comparative Example 4: Different weights of culture added

[0088] In step (3), the weight of the culture was adjusted to 3% of the weight of the sieved material, and the rest was the same as in Example 1.

[0089] Test Example 1 Determination of the content of volatile aroma components

[0090] The volatile aroma components in the distillates of Examples 1 to 11 and Comparative Examples 1 to 4 were measured. The specific method is as follows: 6 mL of sample is put into a headspace bottle, 10 μL of 10 mg / L 2-octanol ethanol solution (ethanol as solvent) and 2.0 g of sodium chloride are added, the bottle is sealed, and the bottle is placed in a constant temperature heating magnetic stirrer for equilibration at 60° C. for 15 min, an extraction needle which has been aged at 270° C. for 1 hour is inserted for headspace adsorption for 45 min, and then the sample is injected into a gas chromatograph for GC-MS analysis, the injection port temperature is 250° C., the analysis is 5 min, and the sample is injected without split flow; the heating program is as follows: the initial column temperature is 40° C., maintained for 5 min, increased to 240° C. at 5° C. / min, maintained for 5 min, and the post-run time is 5 min; the carrier gas is He (purity>99.999%), and the column flow rate is 1.0 mL / min; the MS conditions are as follows: the ionization source is EI, the ionization energy is 70 eV, the ion source temperature is 230° C., the mass spectrometer quadrupole temperature is 150° C., and the mass scanning range (m / z) is 35-450. The GC-MS detection spectrum was matched with the NIST.11 library to qualitatively identify the volatile aroma components. The content of volatile aroma components in tea was calculated using the ratio of the peak area of ​​volatile aroma components to the internal standard (2-octanol).

[0091] The results are shown in Tables 1-3.

[0092] Table 1 Contents of different types of volatile aroma components in the distillates of Examples 1-11 and Comparative Examples 1-4 (μg / g)

[0093]

[0094]

[0095] Note: a, b, c and d respectively indicate that there are significant differences (p<0.05) compared with the content results of comparative examples 1, 2, 3 and 4.

[0096] Table 2 Contents of three main volatile aroma components in the distillates of Examples 1-11 and Comparative Examples 1-4 (μg / g)

[0097]

[0098]

[0099] Note: a, b, c and d respectively indicate that there are significant differences (p<0.05) compared with the content results of comparative examples 1, 2, 3 and 4.

[0100] Table 3 Specific volatile aroma component contents in the distillates of Example 4 and Comparative Example 1

[0101]

[0102]

[0103]

[0104] - indicates not detected.

[0105] According to Table 1-2:

[0106] Compared with the method of Comparative Example 1 which does not adopt monoclonal culture and fermentation, the contents of volatile aroma components of alcohols, esters, aldehydes, ketones and terpenes in the distillate prepared by the method of the present invention are significantly increased (p<0.05), the total amount of volatile aroma components is significantly increased (p<0.05), and the contents of three main volatile aroma components, indole, linalool and geraniol, are significantly increased (p<0.05).

[0107] Compared with the method in Comparative Example 2 which does not use monoclonal culture, the contents of volatile aroma components of alcohols, esters, aldehydes and terpenes in the distillate prepared by the method of the present invention are significantly increased (p<0.05), the total amount of volatile aroma components is significantly increased (p<0.05), and the contents of three main volatile aroma components, indole, linalool and geraniol, are significantly increased (p<0.05).

[0108] Compared with the method of Comparative Example 3 using an excessively long fermentation time, the contents of volatile aroma components of alcohols, esters, aldehydes, ketones, and terpenes in the distillate prepared by the method of the present invention are significantly increased (p<0.05), the total amount of volatile aroma components is significantly increased (p<0.05), and the contents of the three main volatile aroma components of indole, linalool and geraniol are significantly increased (p<0.05).

[0109] Compared with the method of comparative example 4 in which an excess of monoclonal culture was added, the contents of volatile aroma components of alcohols, esters and aldehydes in the distillate prepared by the method of the present invention were significantly increased (p<0.05), the total amount of volatile aroma components was significantly increased (p<0.05), and the content of the volatile aroma component of geraniol was significantly increased (p<0.05).

[0110] According to Table 3, compared with the method of Comparative Example 1 which does not adopt monoclonal culture and fermentation, the types and contents of specific volatile aroma components of alcohols, esters, aldehydes, ketones and terpenes detected in the distillate prepared by the method of Example 4 of the present invention are more and higher.

[0111] The above description shows that the distillate prepared by the method of the present invention has more types of main volatile aroma components, higher contents, and higher total content of volatile aroma components; and the total amount of volatile aroma components in the distillates of Examples 3-9 of the present invention is further increased.

[0112] Test Example 2 Sensory Quality Evaluation

[0113] Using the same blank cigarette, the concentrates of Examples 1 to 11 and Comparative Examples 1 to 4 were added to the tobacco of the blank cigarettes, respectively, with the added weight being 1% of the weight of the blank cigarettes, and the cigarettes were equilibrated for 48 hours in an environment of 22±1°C and RH 60±2%. Ten professional smoking reviewers were organized to perform sensory quality scoring on each cigarette according to the "YC / T 497-2014 Sensory Evaluation Method for Chinese Cigarette Style", and the average result was taken. The results are shown in Tables 4-5.

[0114] Table 4 Sensory quality evaluation results of cigarettes (a difference of 1 point indicates a significant difference)

[0115]

[0116]

[0117] Table 5 Ratings of various aromas of cigarettes (a difference of 0.5 points indicates a significant difference)

[0118]

[0119]

[0120] According to Table 4-5:

[0121] Compared with the method of comparative example 1 which does not adopt monoclonal culture and fermentation, the concentrate prepared by the method of the present invention is added to cigarette shreds, and the aroma quality, aroma richness, delicate softness, and roundness of the smoke when the cigarette is smoked are significantly improved, the impurities are significantly reduced, the smoke concentration is significantly increased, the sensory evaluation score is significantly improved, and the main characteristic aromas such as fresh fragrance, fruity fragrance, floral fragrance and sweet fragrance in the smoke are significantly more intense;

[0122] Compared with the method of comparative example 2 which does not adopt monoclonal culture, the concentrate prepared by the method of the present invention is added to cigarette shreds, and the aroma quality, aroma richness, delicate softness, and roundness of the smoke when the cigarette is smoked are significantly improved, the impurities are significantly reduced, the smoke concentration is significantly increased, the sensory evaluation score is significantly improved, and the main characteristic aromas such as fresh fragrance, fruity fragrance, floral fragrance and sweet fragrance in the smoke are significantly more intense;

[0123] Compared with the method of comparative example 3 using too long a fermentation time, the concentrate prepared by the method of the present invention is added to cigarette shreds, and the aroma quality, aroma richness, delicate softness, and roundness of the smoke when the cigarette is smoked are significantly improved, the impurities are significantly reduced, the smoke concentration is significantly increased, the sensory evaluation score is significantly improved, and the main characteristic aromas of the smoke, such as the fresh fragrance, fruity fragrance, floral fragrance, and sweet fragrance, are significantly more intense;

[0124] Compared with the method of comparative example 4 in which an excessive amount of monoclonal culture is added, the concentrate prepared in Examples 3-4 of the present invention is added to shredded cigarette tobacco, and the aroma quality, aroma richness, delicate and soft degree, and roundness of the smoke when the cigarette is smoked are significantly improved, the impurities are significantly reduced, the smoke concentration is significantly increased, the sensory evaluation score is significantly improved, and the main characteristic aromas of fruity and sweet aromas in the smoke are significantly more intense;

[0125] The above description shows that when the concentrate prepared by the method of the present invention is added to cigarette tobacco, the aroma quality, aroma richness, fineness and softness, and roundness of the smoke when the cigarette is smoked are significantly improved, the impurities are significantly reduced, the smoke concentration is significantly improved, and the sensory evaluation score is significantly improved; and, the main characteristic aromas are fresh fragrance, fruity fragrance, floral fragrance, and sweet fragrance. When the concentrate prepared by the method of the present invention is added to cigarette tobacco, the main characteristic aromas of fresh fragrance, fruity fragrance, floral fragrance, and sweet fragrance in the smoke are significantly more intense.

[0126] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing an extract of Tieguanyin cured product, comprising the following steps: (1) streak the yeast in a solid medium of yeast extract peptone glucose, invert and culture at 25°C-35°C for 20-30 hours, pick a single colony with a clear edge boundary and inoculate it in a liquid medium of yeast extract peptone glucose, shake and culture at 25°C-35°C for 2-10 hours to obtain a culture with an OD600 of 0.1-3; wherein, The yeast is Saccharomyces cerevisiae purchased from China Industrial Microbiological Culture Collection Center with a strain collection number of CICC 1946; (2) crushing and sieving the withered Tieguanyin, collecting the sieved material, spraying or coating the culture on the surface of the sieved material, wherein the weight of the culture is 0.05%-2% of the weight of the sieved material, and fermenting at 25° C.-55° C. for 1-8 hours to obtain a fermentation product; (3) sterilizing the fermentation product, performing steam distillation on the sterilized fermentation product, and collecting the distillate.

2. The method according to claim 1, wherein: Step (1) includes one or more of the following: (A) The yeast is provided in the form of a bacterial suspension; (B) The shaking culture is performed at a shaking speed of 100-200 r / min.

3. The method according to claim 2, wherein: In item (A), the content of live yeast in the bacterial suspension is 10 7 -10 10 CFU / mL.

4. The method according to claim 1, wherein: In step (3), the steam distillation is distillation in water.

5. The method according to claim 4, wherein: The water distillation uses water with a weight that is 10-30 times the weight of the fermentation product.

6. The method according to claim 1, further comprising: (4) Concentrating the distillate.

7. The method according to claim 6, wherein: In step (4), concentration is performed by reverse osmosis treatment.

8. The method according to claim 7, wherein: In step (4), the outlet pressure of the reverse osmosis treatment is 0.5-2.5 MPa, and the operating temperature is 15°C-35°C.

9. The method according to any one of claims 1 to 8, comprising one or more of the following: (a) In step (3), the temperature of steam distillation is 90°C-120°C; (b) In step (3), the steam distillation time is 1-6 hours.

10. The method according to claim 1, wherein: In step (2), pass through a 40-60 mesh sieve.

11. The method according to claim 1, wherein: In step (3), sterilize at 90°C-130°C for 10-30 minutes.

12. An extract of cured Tieguanyin tea, prepared by the method according to any one of claims 1 to 11.

13. The extract of the cured Tieguanyin tea according to claim 12, which is a tobacco flavoring.

14. The extract of the cured Tieguanyin according to claim 12 or 13, comprising one or more of the following: The mass content of alcohol volatile components in the extract of the Tieguanyin cured product is greater than 30 μg / g; The mass content of volatile ester components in the extract of the Tieguanyin cured product is greater than 3 μg / g; The mass content of aldehyde volatile components in the extract of the Tieguanyin cured product is greater than 4 μg / g; The mass content of volatile ketone components in the extract of the Tieguanyin cured product is greater than 2 μg / g; The mass content of terpene volatile components in the extract of the Tieguanyin cured product is greater than 1 μg / g; The total mass content of volatile components in the extract of the Tieguanyin cured product is greater than 40 μg / g; The mass content of indole in the extract of the Tieguanyin cured product is greater than 1.2 μg / g; The mass content of linalool in the extract of the Tieguanyin cured product is greater than 6 μg / g; The mass content of geraniol in the extract of the fixed Tieguanyin is greater than 0.95 μg / g.

15. A tobacco leaf composition comprising the extract of the cured Tieguanyin tea according to any one of claims 12 to 14.

16. A cigarette comprising the extract of the cured Tieguanyin tea according to any one of claims 12 to 14 or the tobacco leaf composition according to claim 15.

Images