CN118266628A - Method for producing aroma by homogenizing and fermenting cigar tobacco leaves and application - Google Patents

Abstract

The invention discloses a method for producing aroma by homogenizing and fermenting cigar tobacco leaves and an application thereof. The method comprises the following steps: S1. performing initial rehumidification on air-dried cigar tobacco leaves, spraying malic acid solution with a pH value of 7-7.5 on the initially rehumidified cigar tobacco leaves, and allowing the rehumidified tobacco leaves to stand for equilibrium to obtain rehumidified tobacco leaves; S2. wrapping the rehumidified tobacco leaves with gauze, and then fermenting the rehumidified tobacco leaves to obtain aroma-producing cigar tobacco leaves; by adding malic acid to rehumidify and ferment the cigar tobacco leaves, not only the aroma content of the fermented cigar tobacco leaves is increased, but also the homogenization degree of the chromaticity and aroma content of the fermented tobacco leaves is increased, and the amount of carotenoid conversion products, cypermethrin degradation products, phenylalanine conversion products and sclareol aroma substances is significantly increased.

Description

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves and its application

Technical Field

The invention relates to the technical field of tobacco agriculture, and in particular to a method for producing aroma by homogenizing and fermenting cigar tobacco leaves and an application thereof.

Background technique

The fermentation preparation process of cigar tobacco is essentially a process that, under certain temperature and humidity conditions, causes profound changes in the physical and chemical properties of tobacco leaves, coordinates the proportions of the main chemical components of tobacco leaves, such as sugar, nitrogen, and alkali, promotes the degradation of internal organic matter, and decomposes it into aroma substances, such as carotenoid degradation products, chlorophyll degradation products, Maillard reaction products, cedarwood degradation products, phenylalanine conversion products, etc., thereby significantly improving the aroma and smoking quality of tobacco leaves.

The use of nutrients in the fermentation process of cigar tobacco leaves can promote the aroma of tobacco leaves. Existing nutrients include ammonium fragrate or ammonium benzoate, ammonium acetate, ammonium tartrate, ammonium cinnamate, ammonium fumarate, ammonium isooctanoate, citric acid, etc., but the effect of increasing the content of specific aroma substances in cigar tobacco leaves is not obvious, and the specific aroma substances include carotenoid conversion products, ceramsite degradation products, phenylalanine conversion products, and clary alcohol.

Therefore, it is necessary to provide a solution to increase the content of specific aroma substances in cigar tobacco leaves after fermentation.

Summary of the invention

In view of this, the present application provides a method and application for producing aroma by homogenizing and fermenting cigar tobacco leaves, which is used to solve the problem of how to increase the content of specific aroma substances in cigar tobacco leaves.

In order to achieve the above technical objectives, this application adopts the following technical solutions:

In a first aspect, a method for producing aroma by homogenizing and fermenting cigar tobacco leaves comprises the following steps:

S1. The cigar leaves after airing were initially moistened, and a malic acid solution having a pH value of 7-7.5 was sprayed on the cigar leaves after the initial moistening, and allowed to stand for equilibrium to obtain moistened tobacco leaves;

S2. Wrap the moistened tobacco leaves with gauze and then ferment them to obtain cigar tobacco leaves.

Preferably, the moisture content of the cigar tobacco leaves after initial moisture conditioning is 20-22%.

Preferably, the moisture content in the moistened tobacco leaves is 30-35%.

Preferably, the fermentation conditions are: relative humidity 75-85%, fermentation temperature 37-39° C., and fermentation time 3-14 days.

Preferably, the mass concentration of malic acid in the tempered tobacco leaves is 1-5 g/kg.

Preferably, the preparation method of the malic acid solution is: adding ammonia water to malic acid and adjusting the pH value to 7-7.5.

Preferably, the number of gauze layers is 8-10 layers.

In a second aspect, the present application provides a method for producing aroma by homogenizing and fermenting cigar tobacco leaves for use in increasing the content of aroma substances in cigar tobacco leaves.

Preferably, the aroma substances include one or more of carotenoid transformation products, ceramsite degradation products, phenylalanine transformation products, and sclareol.

Preferably, the carotenoid conversion product comprises one or more of farnesyl acetone, damascenone, megastigmatrienone, geranyl linalool and β-ionone.

The beneficial effects of this application are as follows:

The present application adds malic acid to cigar tobacco leaves for moisture conditioning and fermentation, thereby significantly increasing the amount of carotenoid conversion products, cypermethrin degradation products, phenylalanine conversion products, and sclareol aroma substances;

The invention has the advantages of simpler and clearer feed ingredients, easy purchase of raw materials, low cost, high controllability of operation, and applicability to cigar tobacco leaf fermentation production;

The present invention improves the homogenization degree of the chromaticity and aroma content of the fermented tobacco leaves. The homogenization refers to the uniformity of the quality of the cigar tobacco leaves, and the uniformity of the quality of the cigar tobacco leaves includes the uniformity of the chromaticity and the total aroma content.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

The present solution is further described below through specific embodiments.

Description of raw materials: The cigar tobacco leaves used in the examples and comparative examples of the present application are tobacco leaves from the middle part of cigar plants grown in the Enshi cigar planting base in Hubei Province, and the variety is Chuxue 14.

Example 1

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, comprising the following steps:

S1. The air-dried cigar tobacco leaves are initially moistened to a moisture content of 20%, and a malic acid solution having a pH value of 7 adjusted with ammonia water is sprayed on the cigar tobacco leaves after the initial moistening, and the solution is allowed to stand for equilibrium to obtain moistened tobacco leaves, wherein the mass concentration of malic acid in the moistened tobacco leaves is 1 g/kg, and the moisture content of the moistened tobacco leaves is 34%;

S2. Wrap the rehydrated tobacco leaves with 8 layers of gauze and place them in unsealed ziplock bags, each containing 2 kg of rehydrated tobacco leaves. Then place them in a constant temperature and humidity incubator at a relative humidity of 80% and 37°C for 6 days to obtain cigar-producing tobacco leaves.

Example 2

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, comprising the following steps:

S1. The air-dried cigar tobacco leaves are initially moistened to a moisture content of 20%, and a malic acid solution having a pH value of 7 adjusted with ammonia water is sprayed on the cigar tobacco leaves after the initial moistening, and the solution is allowed to stand for equilibrium to obtain moistened tobacco leaves, wherein the mass concentration of malic acid in the moistened tobacco leaves is 2 g/kg, and the moisture content of the moistened tobacco leaves is 34%;

S2. Wrap the rehydrated tobacco leaves with 8 layers of gauze and place them in unsealed ziplock bags, each containing 2 kg of rehydrated tobacco leaves. Then place them in a constant temperature and humidity incubator at a relative humidity of 80% and 37°C for 6 days to obtain cigar-producing tobacco leaves.

Example 3

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, comprising the following steps:

S1. The air-dried cigar tobacco leaves are initially moistened to a moisture content of 20%, and a malic acid solution having a pH value of 7 adjusted with ammonia water is sprayed on the cigar tobacco leaves after the initial moistening, and the solution is allowed to stand for equilibrium to obtain moistened tobacco leaves, wherein the mass concentration of malic acid in the moistened tobacco leaves is 3 g/kg, and the moisture content of the moistened tobacco leaves is 34%;

S2. Wrap the rehydrated tobacco leaves with 8 layers of gauze and place them in unsealed ziplock bags, each containing 2 kg of rehydrated tobacco leaves. Then place them in a constant temperature and humidity incubator at a relative humidity of 80% and 37°C for 6 days to obtain cigar-producing tobacco leaves.

Example 4

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, comprising the following steps:

S1. The air-dried cigar tobacco leaves are initially moistened to a moisture content of 20%, and a malic acid solution having a pH value of 7 adjusted with ammonia water is sprayed on the cigar tobacco leaves after the initial moistening, and the solution is allowed to stand for equilibrium to obtain moistened tobacco leaves, wherein the mass concentration of malic acid in the moistened tobacco leaves is 4 g/kg, and the moisture content of the moistened tobacco leaves is 34%;

S2. Wrap the rehydrated tobacco leaves with 8 layers of gauze and place them in unsealed ziplock bags, each containing 2 kg of rehydrated tobacco leaves. Then place them in a constant temperature and humidity incubator at a relative humidity of 80% and 37°C for 6 days to obtain cigar-producing tobacco leaves.

Example 5

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, the other contents of which are the same as those of Example 1, except that the mass concentration of malic acid in the conditioned tobacco leaves is 5 g/kg.

Example 6

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves:

(1) Tobacco leaf moisture recovery

After the air-dried cigar tobacco leaves are re-humidified to a moisture content of 20-22%, a certain amount of water is weighed as re-humidification water, sprayed with the re-humidification water and turned over the tobacco leaves. Let them stand to balance the moisture in the tobacco leaves (moisture content is 34%).

(2) Tobacco leaf fermentation

Cigar tobacco leaves are fermented in 100 kg box fermentation rooms with a temperature of 30°C and a humidity of 80%.

Box-type fermented tobacco stacking method: The fermentation box is 120 cm long, 80 cm wide, 80 cm high, and the bottom of the box is 10 cm from the ground. The tobacco leaves are stacked layer by layer with their petioles facing outwards, and cotton cloth and box cover are placed on the top of the stacked tobacco leaves.

Box fermentation cycle: Place a temperature sensor in the core of the tobacco pile to observe temperature changes during the fermentation process. When the pile temperature rises to the maximum value and then slowly drops to a certain temperature and maintains for about 1 day, the pile is turned over. One fermentation cycle is about 8 days. Preliminary studies have determined that the aroma content of cigar tobacco samples is the highest after the third turning of the pile, so it is determined that fermentation ends after the third turning of the pile.

Sampling during the fermentation process: Sampling is taken before and after tobacco fermentation (during the third turning of the pile).

Sampling method: The pile body is divided into three layers at a distance of 1/3, and four sampling points are set at the cross of 1/3 of the plane diameter on each layer. The core is one sampling point, and there are five sampling points in total. 1 kg of cigar tobacco leaves are randomly selected from each of them. They are the samples before fermentation and the third turning samples of the natural fermentation group. Each sample is composed of tobacco leaves taken from 15 sampling points (three layers, top, middle and bottom, 5 sampling points in each layer).

(3) Sample chromaticity value detection

The samples were tested using a colorimeter. The colorimetric indicators measured mainly include lightness value (L*), red-green value (a*, positive value represents redness, negative value represents greenness), and yellow-blue value (b*, positive value represents yellowness, negative value represents blueness). Three representative leaves without damage or spots were selected from each sampling point (three layers of upper, middle and lower, 5 sampling points in each layer, 3 tobacco leaves were taken from each sampling point, a total of 45 leaves) as test objects for measurement. Five points were selected symmetrically at the tip, middle and base of each tobacco leaf, avoiding the veins when selecting points, and the measurement was performed. The chromaticity value is expressed as the average value ± standard deviation of the measurement data of the above 225 tobacco leaf measurement points.

(4) Sample processing and aroma substance content detection

Each sample consists of tobacco leaves taken from 15 sampling points. 100 g of the samples from these 15 sampling points were evenly sampled, dried and crushed with a pulverizer. The samples after passing through a 40-mesh sieve were sealed and stored at 4°C. 10 g of ground tobacco powder was accurately weighed and the aroma substance content of tobacco leaves was determined by simultaneous distillation extraction (SDE)-gas chromatography-mass spectrometry (GC-MS). The specific operation is as follows: 10 grams of tobacco foam sample was placed in a 1000 mL round-bottom flask of the simultaneous distillation extraction device (SDE), NaCl was added to form saturated salt water, and 60 mL of dichloromethane was placed in another 100 mL round-bottom flask, and then the two round-bottom flasks were connected to both sides of the SDE device; the organic phase (dichloromethane) was heated in a 55°C water bath, and the aqueous phase was heated in a 160°C oil bath. When the liquid in the distillation extraction tube refluxed to the flasks on both sides, the timing was started. After 2 h, the test solution after simultaneous distillation extraction was collected, anhydrous sodium sulfate was added to remove water, and then it was concentrated to 1~2 mL on a rotary evaporator under reduced pressure to obtain a concentrated solution. After filtering the concentrated solution, the content of aroma substances was determined by gas chromatography-mass spectrometry (GC-MS). The content of aroma substances in the sample was expressed as the average value ± standard deviation of the measured data of the samples at the above 15 sampling points.

GC-MS conditions: chromatographic column: HP-5MS capillary column (30 m×0.25 mm, 0.25 μm); the chromatographic column temperature program was 40℃ for 2 min, 2℃/min to 200℃, 5 min, and then 10℃/min to 280℃; carrier gas (He) flow rate: 1 mL/min; injection volume: 1 μL; split ratio: 10:1. Electron bombardment ion source; electron energy 70 eV; transfer line temperature: 250℃; ion source temperature: 230℃; mass scan range m/z 35~550. Peak identification of target compounds was based on the National Institute of Standards and Technology database (NIST14). After the main veins were removed and dried, the tobacco leaves were crushed and passed through a 40-mesh sieve. The aroma components were extracted using a simultaneous distillation extraction device, and the aroma components were analyzed using GC-MS.

At the end of the pilot fermentation, the brightness value of the tobacco leaves of Example 6 (natural fermentation, control) was 34±1.9; the red-green value of the tobacco leaves of Example 6 (natural fermentation, control) was 12±0.85; and the yellow-blue value of the tobacco leaves of Example 6 (natural fermentation, control) was 18±1.6.

After the samples were treated, the content of aroma substances was determined by simultaneous distillation-gas chromatography. The content of aroma substances before fermentation was 256.84 μg/g, and the content of aroma substances in Example 6 (natural fermentation, control) was 762 μg/g±128.67.

Example 7

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves:

(1) Tobacco leaf moisture recovery

Dissolve malic acid in warm water and use ammonia water to adjust the pH value to 7-7.5 to make rehumidification water. Rehumidify the air-dried cigar tobacco leaves to a moisture content of 20-22% and a malic acid content of 3 g/kg. Weigh a certain amount of water to use as rehumidification water, spray the rehumidification water and turn the tobacco leaves. Let it stand to balance the moisture in the tobacco leaves (moisture content is 34%).

(2) Tobacco leaf fermentation

Cigar tobacco leaves are fermented in 100 kg box fermentation rooms with a temperature of 30°C and a humidity of 80%.

Box-type fermented tobacco stacking method: The fermentation box is 120 cm long, 80 cm wide, 80 cm high, and the bottom of the box is 10 cm from the ground. The tobacco leaves are stacked layer by layer with their petioles facing outwards, and cotton cloth and box cover are placed on the top of the stacked tobacco leaves.

Box fermentation cycle: Place a temperature sensor in the core of the tobacco pile to observe temperature changes during the fermentation process. When the pile temperature rises to the maximum value and then slowly drops to a certain temperature and maintains for about 1 day, the pile is turned over. One fermentation cycle is about 8 days. Preliminary studies have determined that the aroma content of cigar tobacco samples is the highest after the third turning of the pile, so it is determined that fermentation ends after the third turning of the pile.

Sampling during the fermentation process: Sampling is taken before and after tobacco fermentation (during the third turning of the pile).

Sampling method: The pile body is divided into three layers at a distance of 1/3, and four sampling points are set at the cross of 1/3 of the plane diameter on each layer. The core is one sampling point, and there are five sampling points in total. 1 kg of cigar tobacco leaves are randomly selected from each of them. They are the samples before fermentation and the third turning samples of the malic acid group. Each sample is composed of tobacco leaves taken from 15 sampling points (three layers, top, middle and bottom, 5 sampling points in each layer).

(3) Sample chromaticity value detection

The samples were tested using a colorimeter. The colorimetric indicators measured mainly include lightness value (L*), red-green value (a*, positive value represents redness, negative value represents greenness), and yellow-blue value (b*, positive value represents yellowness, negative value represents blueness). Three representative leaves without damage or spots were selected from each sampling point (3 layers, upper, middle and lower, 5 sampling points in each layer, 3 tobacco leaves from each sampling point, a total of 45 leaves) as test objects for measurement. Five points were selected symmetrically at the tip, middle and base of each tobacco leaf, avoiding the veins when selecting points, and the measurement was performed. The chromaticity value is expressed as the average value ± standard deviation of the measurement data of the above 225 tobacco leaf measurement points.

(4) Sample processing and aroma substance content detection

Each sample consists of tobacco leaves taken from 15 sampling points. 100 g of the samples from these 15 sampling points were evenly sampled, dried and crushed with a pulverizer. The samples after passing through a 40-mesh sieve were sealed and stored at 4°C. 10 g of ground tobacco powder was accurately weighed and the aroma substance content of tobacco leaves was determined by simultaneous distillation extraction (SDE)-gas chromatography-mass spectrometry (GC-MS). The specific operation is as follows: 10 grams of tobacco foam sample was placed in a 1000 mL round-bottom flask of the simultaneous distillation extraction device (SDE), NaCl was added to form saturated salt water, and 60 mL of dichloromethane was placed in another 100 mL round-bottom flask, and then the two round-bottom flasks were connected to both sides of the SDE device; the organic phase (dichloromethane) was heated in a 55°C water bath, and the aqueous phase was heated in a 160°C oil bath. When the liquid in the distillation extraction tube refluxed to the flasks on both sides, the timing was started. After 2 h, the test solution after simultaneous distillation extraction was collected, anhydrous sodium sulfate was added to remove water, and then it was concentrated to 1~2 mL on a rotary evaporator under reduced pressure to obtain a concentrated solution. After filtering the concentrated solution, the content of aroma substances was determined by gas chromatography-mass spectrometry (GC-MS). The content of aroma substances in the sample was expressed as the average value ± standard deviation of the measured data of the samples at the above 15 sampling points.

GC-MS conditions: chromatographic column: HP-5MS capillary column (30 m×0.25 mm, 0.25 μm); the chromatographic column temperature program was 40℃ for 2 min, 2℃/min to 200℃, 5 min, and then 10℃/min to 280℃; carrier gas (He) flow rate: 1 mL/min; injection volume: 1 μL; split ratio: 10:1. Electron bombardment ion source; electron energy 70 eV; transfer line temperature: 250℃; ion source temperature: 230℃; mass scan range m/z 35~550. Peak identification of target compounds was based on the National Institute of Standards and Technology database (NIST14). After the main veins were removed and dried, the tobacco leaves were crushed and passed through a 40-mesh sieve. The aroma components were extracted using a simultaneous distillation extraction device, and the aroma components were analyzed using GC-MS.

At the end of the pilot fermentation, the brightness value of the tobacco leaves in the malic acid group was 36±1.5, while that in Example 6 was 34±1.9. This indicates that malic acid promotes the brightness of the tobacco leaves after fermentation, and the standard deviation of the tobacco leaves in the whole box is reduced by 21%. That is, the uniformity of the brightness of the tobacco leaves in Example 7 after fermentation is improved by 21%.

The red-green value of the tobacco leaves in the malic acid group was 12±0.81, while that of Example 6 (natural fermentation, control) was 12±0.85. Explanation: The redness of the tobacco leaves after fermentation was close, and the standard deviation of the tobacco leaves in the whole box was reduced by 5%. That is, the uniformity of the redness of the tobacco leaves in Example 7 after fermentation was improved by 5%.

The yellow-blue value of tobacco leaves in the malic acid group was 20±1.1, while that in Example 6 (natural fermentation, control) was 18±1.6. Explanation: Malic acid promoted the yellowness of tobacco leaves after fermentation, and the standard deviation of the whole box of tobacco leaves was reduced by 31%. That is, the uniformity of the yellowness of tobacco leaves in Example 7 after fermentation was improved by 31%.

At the end of the pilot fermentation, the sample was treated and the content of aroma substances was measured by simultaneous distillation-gas chromatography. The total aroma of the malic acid group (excluding neophytadiene) was 1488 μg/g±52.47, while that of Example 6 (natural fermentation, control) was 762 μg/g±128.67. Malic acid promoted the total aroma of the fermented tobacco leaves, significantly increasing it by 95%, and the standard deviation of the total aroma content of the tobacco leaves was reduced by 59%. That is, the uniformity of the total aroma of the tobacco leaves after fermentation in Example 7 was increased by 59%.

Malic acid not only increases the aroma content of fermented cigar tobacco leaves, but surprisingly, it also increases the homogeneity of color and aroma content, achieving excellent technical results and providing a technical solution for the homogenization processing of cigar tobacco leaves in my country.

Comparative Example 1

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, comprising the following steps:

S1. The air-dried cigar tobacco leaves were initially moistened to a moisture content of 20%, and pure water was added to the cigar tobacco leaves after the initial moistening, and the moistened tobacco leaves were allowed to stand for equilibrium to obtain moistened tobacco leaves, wherein the moisture content of the moistened tobacco leaves was 34%;

S2. Wrap the rehydrated tobacco leaves with 8 layers of gauze and place them in unsealed ziplock bags, each containing 2 kg of rehydrated tobacco leaves. Then place them in a constant temperature and humidity incubator at a relative humidity of 80% and 37°C for 6 days to obtain cigar-producing tobacco leaves.

Comparative Example 2

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, the other contents of which are the same as those of Example 2, except that malic acid is replaced by citric acid.

Comparative Example 3

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, the other contents of which are the same as those of Example 3, except that malic acid is replaced by citric acid.

Comparative Example 4

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, the other contents of which are the same as those of Example 5, except that malic acid is replaced by citric acid.

Comparative Example 5

A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, comprising the following steps:

S1. The air-dried cigar tobacco leaves are initially conditioned to a moisture content of 20%, and the same mass of ammonia water in Example 1 is weighed and dissolved in the conditioned water, and the pH value is adjusted to 7 with dilute hydrochloric acid, and the conditioned leaves are allowed to stand for equilibrium to obtain conditioned tobacco leaves, wherein the moisture content of the conditioned tobacco leaves is 34%;

S2. Wrap the rehydrated tobacco leaves with 8 layers of gauze and place them in unsealed ziplock bags, each containing 2 kg of rehydrated tobacco leaves. Then place them in a constant temperature and humidity incubator at a relative humidity of 80% and 37°C for 6 days to obtain cigar-producing tobacco leaves.

Test and Evaluation

The cigar tobacco leaves obtained in Examples 1-4 and Comparative Example 1 were processed and the sclareol content was detected, and the steps were as follows:

100 g of sample was uniformly taken, dried and crushed with a pulverizer, and the sample after passing through a 40-mesh sieve was sealed and stored at 4°C. 10 g of ground tobacco powder was accurately weighed and the concentration of sclareol in tobacco leaves was determined by simultaneous distillation extraction (SDE)-gas chromatography-mass spectrometry (GC-MS). The specific operation was as follows: 10 g of tobacco foam sample was placed in a 1000 mL round-bottom flask of the simultaneous distillation extraction device (SDE), NaCl was added to form saturated salt water, and 60 mL of dichloromethane was placed in another 100 mL round-bottom flask, and then the two round-bottom flasks were connected to both sides of the SDE device; the organic phase (dichloromethane) was heated in a 55°C water bath, and the aqueous phase was heated in a 160°C oil bath. When the liquid in the distillation extraction tube refluxed to the flasks on both sides, the timing was started. After 2 h, the distillate after simultaneous distillation extraction was collected, anhydrous sodium sulfate was added to remove water, and then it was concentrated to 1~2 mL on a rotary evaporator under reduced pressure to obtain a concentrated solution. The concentrated solution was filtered and the content of sclareol was determined by gas chromatography-mass spectrometry (GC-MS).

GC-MS conditions: chromatographic column: HP-5MS capillary column (30 m×0.25 mm, 0.25 μm); the chromatographic column temperature program was 40°C for 2 min, then increased to 200°C at 2°C/min, maintained for 5 min, and then increased to 280°C at 10°C/min; carrier gas (He) flow rate: 1 mL/min; injection volume: 1 μL; split ratio: 10:1. Electron bombardment ion source; electron energy 70 eV; transfer line temperature: 250°C; ion source temperature: 230°C; mass scan range m/z 35-550. Peak identification of target compounds was based on the National Institute of Standards and Technology database (NIST14).

The results of testing the sclareol content of the samples of Examples 1-4 and Comparative Example 1 after treatment by simultaneous distillation-gas chromatography are shown in Table 1.

Table 1 Test results of sclareol content in cigar tobacco leaves in Examples 1-4 and Comparative Example 1

The cigar tobacco leaves produced in Examples 1-5 and Comparative Examples 1-4 were treated and the contents of carotenoid conversion products, ceborane degradation products, and phenylalanine conversion products were detected. The method steps are as follows:

100 g of sample was uniformly taken, dried and crushed with a pulverizer, and the sample after passing through a 40-mesh sieve was sealed and stored at 4°C. 10 g of ground tobacco powder was accurately weighed and the concentration of sclareol in tobacco leaves was determined by simultaneous distillation extraction (SDE)-gas chromatography-mass spectrometry (GC-MS). The specific operation was as follows: 10 g of tobacco foam sample was placed in a 1000 mL round-bottom flask of the simultaneous distillation extraction device (SDE), NaCl was added to form saturated salt water, and 60 mL of dichloromethane was placed in another 100 mL round-bottom flask, and then the two round-bottom flasks were connected to both sides of the SDE device; the organic phase (dichloromethane) was heated in a 55°C water bath, and the aqueous phase was heated in a 160°C oil bath. When the liquid in the distillation extraction tube refluxed to the flasks on both sides, the timing was started. After 2 h, the distillate after simultaneous distillation extraction was collected, anhydrous sodium sulfate was added to remove water, and then it was concentrated to 1~2 mL on a rotary evaporator under reduced pressure to obtain a concentrated solution. The concentrate was filtered and the aroma content was determined by gas chromatography-mass spectrometry (GC-MS).

GC-MS conditions: chromatographic column: HP-5MS capillary column (30 m×0.25 mm, 0.25 μm); the chromatographic column temperature program was 40°C for 2 min, then increased to 200°C at 2°C/min, maintained for 5 min, and then increased to 280°C at 10°C/min; carrier gas (He) flow rate: 1 mL/min; injection volume: 1 μL; split ratio: 10:1. Electron bombardment ion source; electron energy 70 eV; transfer line temperature: 250°C; ion source temperature: 230°C; mass scan range m/z 35-550. Peak identification of target compounds was based on the National Institute of Standards and Technology database (NIST14).

The test results are shown in Table 2.

Table 2 Results of the content detection of carotenoid transformation products, ceramidine degradation products, and phenylalanine transformation products

The content distribution of carotenoids in the cigar tobacco leaves obtained in Examples 1-4 and Comparative Example 1 is shown in Table 3. Carotenoids include nysyl acetone, damascenone, megastigmatrienone, geranyl linalool, and β-ionone.

Table 3 Distribution of carotenoid content

The above results indicate that the present application can achieve a better aroma production increment effect by using a certain amount of malic acid, while the use of citric acid or excessive malic acid cannot achieve a better aroma production increment effect. At the same time, Table 2 also indicates that the promoting effect of malic acid on the aroma production of cigar tobacco fermentation in the embodiment is not caused by ammonia water after adjusting the pH to neutral.

The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims (10)

1. A method for producing aroma by homogenizing and fermenting cigar tobacco leaves, characterized in that it comprises the following steps: S1. The cigar leaves after airing were initially moistened, and a malic acid solution having a pH value of 7-7.5 was sprayed on the cigar leaves after the initial moistening, and allowed to stand for equilibrium to obtain moistened tobacco leaves; S2. Wrapping the tempered tobacco leaves with gauze and then fermenting them to obtain cigar tobacco leaves. 2. The method for producing aroma by homogenizing and fermenting cigar tobacco leaves according to claim 1, characterized in that the moisture content of the cigar tobacco leaves after initial moisture conditioning is 20-22%. 3. The method for producing aroma by homogenizing and fermenting cigar tobacco leaves according to claim 1, characterized in that the moisture content of the tempered tobacco leaves is 30-35%. 4. The method for producing aroma by homogenizing and fermenting cigar tobacco leaves according to claim 1, characterized in that the fermentation conditions are: relative humidity 75-85%, fermentation temperature 37-39° C., and fermentation time 3-14 days. 5. The method for producing aroma by homogenizing and fermenting cigar tobacco leaves according to claim 1, characterized in that the mass concentration of malic acid in the tempered tobacco leaves is 1-5 g/kg. 6. The method for producing aroma by homogenizing and fermenting cigar tobacco leaves according to claim 1, characterized in that the malic acid solution is prepared by adding ammonia water to malic acid and adjusting the pH value to 7-7.5. 7. The method for producing aroma by homogenizing and fermenting cigar tobacco leaves according to claim 1, characterized in that the number of layers of the gauze is 8-10. 8. Application of the method according to any one of claims 1 to 7 in the content of aroma substances in cigar tobacco leaves. 9. The use according to claim 8, characterized in that the aroma substances include one or more of carotenoid transformation products, ceramsite degradation products, phenylalanine transformation products, and sclareol. 10. The use according to claim 9, characterized in that the carotenoid conversion product comprises one or more of farnesyl acetone, damascenone, megastigmatrienone, geranyl linalool, and β-ionone.