Fermentation method for improving uniformity and dark color degree of cigar tobacco leaves and product and application thereof

Abstract

The invention provides a fermentation method for improving uniformity and dark color degree of cigar tobacco leaves and a product and application thereof. The fermentation method comprises the steps of inoculation with a complex microbial inoculant, tobacco leaf fermentation and fermentation ending, wherein the strains in the complex microbial inoculant comprise a combination of aspergillus niger, aspergillus oryzae and rhizopus strains. According to the method, mixed flora of aspergillus niger, aspergillus oryzae and rhizopus strains is adopted for inoculating the cigar tobacco leaves to promote fermentation, so that enzyme system complementation is achieved, generation of multi-target enzymes is covered, sufficient degradation of macromolecular substances is promoted, the fermentation effect is improved, and the fermented cigar tobacco leaf product with high uniformity and deep color degree is prepared.

Description

Technical Field

[0001] The present invention belongs to the technical field of tobacco leaf processing, and in particular relates to a fermentation method for improving the uniformity and darkening degree of cigar tobacco leaves, as well as a product and application thereof. Background Art

[0002] The color uniformity and darkening degree of cigar tobacco leaves are key indicators of their quality, closely related to the degree of fermentation, market value, and sensory experience. A higher degree of darkening indicates a more advanced fermentation process, resulting in a better taste and aroma. However, due to limitations in fermentation technology, cigar raw materials still exhibit color unevenness and pale hues after agricultural fermentation.

[0003] Conventional stack fermentation relies on the tobacco leaves' own heating or constant temperature and humidity, resulting in an imbalance between the enzymatic browning (polyphenol oxidase activity) and Maillard reaction (non-enzymatic browning) processes, leading to unstable pigment production. There are relatively few reports in the prior art on controlling the fermentation process by directional regulation of the microbial community in tobacco leaf fermentation. Therefore, it is difficult to maximize enzyme activity efficiency, which can easily lead to insufficient degradation efficiency of macromolecules such as starch, protein, and cellulose, a shortage of Maillard reaction substrates (reducing sugars, free amino acids), and limited melanoidin synthesis. Aspergillus niger, Aspergillus oryzae, and Rhizopus species play an important role in traditional brewing (such as soy sauce and alcohol) and modern bioengineering (such as enzyme preparations and organic acids) due to the specificity of their enzyme systems and the functionality and safety of their metabolites. In response to some existing problems in the processing of cigar raw materials, how to provide a composite fermentation agent that can efficiently promote fermentation and the degradation of related components in tobacco leaves for fermentation, so as to improve the fermentation effect through the synergistic enhancement of mixed bacterial communities, and dynamically regulate the fermentation process parameters in stages according to the metabolic characteristics of the bacterial communities and the requirements of biochemical reactions to ensure the maximization of enzyme activity and the stability of pigment production, and ultimately achieve the darkening, homogenization and quality upgrade of cigar raw materials, which has important application value. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a fermentation method and its products and applications for improving the uniformity and darkening degree of cigar tobacco leaves.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a fermentation method for improving the uniformity and darkening degree of cigar tobacco leaves, the fermentation method comprising inoculating a composite bacterial agent, fermenting the tobacco leaves, and ending the fermentation;

[0007] Among them, the strains in the composite bacterial agent include a combination of Aspergillus niger, Aspergillus oryzae and Rhizopus strains.

[0008] In the present invention, a mixed bacterial community of Aspergillus niger, Aspergillus oryzae and Rhizopus strains is used to inoculate cigar tobacco leaves to promote fermentation, so as to achieve enzyme complementarity, cover the generation of multi-target enzymes, promote the full degradation of macromolecular substances, and improve the fermentation effect; wherein, (1) α-amylase and saccharifying enzyme produced by Aspergillus niger metabolism can efficiently decompose starch in tobacco leaves into dextrin and glucose components; Aspergillus oryzae can efficiently liquefy starch, and Rhizopus strains can thoroughly decompose α-1,4 glycosidic bonds and α-1,6 glycosidic bonds in starch. The three can synergistically significantly improve the starch degradation efficiency and increase the degree of saccharification; (2) ) Aspergillus niger and Aspergillus oryzae also metabolize and produce acidic proteases and neutral proteases respectively. The combination of the two can meet the protein degradation needs under different pH conditions; and the organic acids such as lactic acid produced by Rhizopus strains can also regulate the pH of the fermentation environment, thereby further regulating the pH of the fermentation system and optimizing the activity of proteases; (3) The quinones produced by Aspergillus niger, the phenolic precursors released by Aspergillus oryzae when decomposing ester bonds, and the organic acids produced by Rhizopus can all improve the efficiency of the classified oxidation reaction mediated by polyphenol oxidase (PPO) contained in tobacco leaves to varying degrees, thereby improving the fermentation effect of cigar tobacco leaves. In addition, the application of the above-mentioned specific mixed bacterial agents can further promote the efficient utilization of carbon and nitrogen sources, enhance the production of flavor substances, enrich the flavor level of tobacco leaves, and effectively resist miscellaneous bacteria and improve the stability of fermentation.

[0009] Preferably, the ratio of the viable counts of the Aspergillus niger, Aspergillus oryzae and Rhizopus strains is (1-10):(1-10):(0.1-1);

[0010] The above “1-10” may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.;

[0011] The above-mentioned “0.1-1” can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.;

[0012] In the present invention, based on the synergistic effect of the above three types of strains in the tobacco leaf fermentation process, when they are used within the above specific dosage ratio range, the mixed fermentation treatment effect is better.

[0013] Preferably, the Rhizopus strain includes any one of Rhizopus stolonifer, Rhizopus chinensis or Rhizopus oryzae, or a combination of at least two thereof, preferably a combination of Rhizopus stolonifer, Rhizopus chinensis and Rhizopus oryzae.

[0014] In the present invention, it is further discovered that when the Rhizopus strain adopts a combination of three strains of Rhizopus stolonifer, Rhizopus chinensis and Rhizopus oryzae, there is also a synergistic relationship between these three specific Rhizopus species, and they have a synergistic enhancement relationship in regulating the fermentation conditions of the strains and improving the fermentation effect.

[0015] Preferably, the ratio of the number of live Rhizopus stolonifer, Rhizopus chinensis and Rhizopus oryzae is (1-10):(1-10):(1-10), wherein "1-10" can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0016] Preferably, the total viable bacteria content in the composite bacterial agent is not less than 1×10 5 CFU / mL or 1×10 5 CFU / g, for example, can be 1×10 5 CFU / mL (CFU / g), 3×10 5 CFU / mL (CFU / g), 4×10 5 CFU / mL (CFU / g), 5×10 5 CFU / mL (CFU / g), 8×10 5 CFU / mL (CFU / g), 1×10 6 CFU / mL (CFU / g), 5×10 6 CFU / mL (CFU / g), 1×10 7 CFU / mL (CFU / g), 1×10 8 CFU / mL (CFU / g), etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0017] Preferably, the content of live bacteria in the composite bacterial agent is 1×10 5 -1×10 6 CFU / mL (CFU / g).

[0018] In the present invention, when the live bacteria content of the composite bacterial agent is within the above-mentioned specific range, the fermentation effect on tobacco leaves is better.

[0019] Preferably, the dosage of the composite bacterial agent is 1%-5% of the mass of the cigar tobacco leaves, for example, it can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc. Other specific values ​​within this numerical range can be selected and will not be repeated here.

[0020] In the present invention, when the dosage of the composite bacterial agent is within the above-mentioned specific range, the fermentation effect on tobacco leaves is better.

[0021] Preferably, the fermentation in the tobacco leaf fermentation stage adopts stack fermentation.

[0022] Preferably, the height of the smoke stack in the stack is not higher than 60 cm, for example, it can be 60 cm, 58 cm, 56 cm, 55 cm, 54 cm, 53 cm, 52 cm, etc.; the smoke stack density is 80-100 kg / m 3, for example, it can be 80kg / m 3 , 82kg / m 3 、85kg / m 3 ,88kg / m 3 , 90kg / m 3 , 92kg / m 3 , 95kg / m 3 , 98kg / m 3 、100kg / m 3 wait.

[0023] In the present invention, the height and density of tobacco stacks are controlled during tobacco fermentation. Stacking that is too high or too dense will lead to heat accumulation in the central area (fermentation heat generation), causing local temperature to exceed the standard (such as >60°C), resulting in enzyme inactivation or bacterial death. The height limit of the tobacco stack ensures uniform heat distribution and avoids local overheating; density control can maintain moderate air permeability and promote the coordinated metabolism of strains.

[0024] Preferably, the tobacco leaf fermentation is carried out in stages, which specifically include the following stages in chronological order:

[0025] S1, bacterial growth stage: adjust the fermentation chamber temperature to 30-35°C (for example, 30°C, 31°C, 32°C, 33°C, 34°C, 34.5°C, 35°C, etc.), the humidity to 85%-90% (for example, 85%, 86%, 87%, 88%, 89%, 90%, etc.), and the fermentation period to 2-4 days (for example, 2 days, 2.5 days, 3 days, 3.5 days, 4 days, etc.);

[0026] S2, enzyme synthesis stage: adjust the fermentation chamber temperature to 28-30°C (e.g., 28°C, 28.5°C, 29°C, 29.5°C, 30°C, etc.), the humidity to 75%-80% (e.g., 75%, 76%, 77%, 78%, 79%, 80%, etc.), and the fermentation period to 3-5 days (e.g., 3 days, 3.5 days, 4 days, 4.5 days, 5 days, etc.);

[0027] S3, macromolecule decomposition stage: adjust the fermentation chamber temperature to 35-38°C (for example, 35°C, 36°C, 37°C, 37.5°C, 38°C, etc.), the humidity to 70%-75% (for example, 70%, 71%, 72%, 73%, 74%, 75%, etc.), and the fermentation period to 5-10 days (for example, 5 days, 5.5 days, 6 days, 6.5 days, 7 days, 7.5 days, 8 days, 9 days, 10 days, etc.);

[0028] S4, enzyme activity-driven degradation and flavor formation stage: adjust the fermentation chamber temperature to 40-45°C (for example, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, etc.), the humidity to 70%-75% (for example, 70%, 71%, 72%, 73%, 74%, 75%, etc.), and the fermentation period to 7-14 days (for example, 7 days, 7.5 days, 8 days, 9 days, 10 days, 12 days, 14 days, etc.);

[0029] S5, non-enzymatic reaction and flavor stabilization stage: adjust the temperature of the fermentation chamber to 50-55°C (for example, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, etc.), the humidity to 65%-70% (for example, 65%, 66%, 67%, 68%, 70%, etc.), and the fermentation cycle to 7-14 days (for example, 7 days, 7.5 days, 8 days, 9 days, 10 days, 12 days, 14 days, etc.).

[0030] The fermentation process is carried out in stages by controlling temperature and humidity, and by precisely matching the metabolic characteristics of the bacterial flora with the requirements of biochemical reactions, it promotes the improvement and stabilization of color and flavor.

[0031] Among them, in the first stage (bacteria growth stage), the dominant bacterial community is quickly established, the adaptation period is shortened, and contamination by competitive bacteria is avoided. The high temperature and high humidity parameters are set to simulate the natural growth environment of fungi to accelerate the spore germination of Aspergillus niger, Aspergillus oryzae and Rhizopus. High humidity can maintain moisture on the surface of tobacco leaves, promote the growth of target bacterial community and inhibit the reproduction of miscellaneous bacteria (such as Penicillium); in the second stage (enzyme synthesis stage), the temperature and relative humidity are appropriately lowered, the enzyme production cycle is extended, and the complementarity of the enzyme system is enhanced. The neutral protease of Aspergillus oryzae and the acid protease of Aspergillus niger are most active in this stage. Rhizopus strains secrete saccharifying enzymes to synergistically decompose starch and cellulose in tobacco leaves; in the third stage (macromolecule decomposition stage), medium and high temperatures are used to activate the cellulase and pectinase of Aspergillus niger, accelerating the degradation of lignin and pectin; at the same time, the protease of Aspergillus oryzae continues to decompose proteins into free amino acids, which are used for subsequent Maillard reaction. The substrate should be provided; in the fourth stage (enzyme-driven degradation and flavor formation stage), the color of tobacco leaves is promoted to deepen evenly, and the temperature is appropriately increased to promote the activity of polyphenol oxidase (PPO), catalyzing the oxidation of phenols such as chlorogenic acid into dark quinones. At the same time, the Maillard reaction is accelerated (sugar and amino acids produce caramelized sweet substances such as ethyl 2-phenylacetate), and the lactic acid produced by Rhizopus enhances enzyme stability; in the fifth stage (non-enzymatic reaction and flavor stabilization stage), high temperature inhibits the activity of polyphenol oxidase and other oxidases to prevent the excessive degradation or further oxidation of the generated melanin (such as chlorogenic acid and rutin oxidation products) into light-colored substances, reduce the side reactions of quinone intermediates, and avoid the formation of unstable transitional pigments. This mechanism can ensure the stability of pigment accumulation. High temperature can also promote caramelization reaction and stabilization of Maillard end products, while reducing moisture interference and avoiding the risk of mildew.

[0032] Preferably, the tobacco leaves are also subjected to stacking treatment during fermentation.

[0033] Preferably, the frequency of stacking is once every 3-5 days.

[0034] Preferably, the moisture content of the tobacco leaves is adjusted to 13%-16% at the end of the fermentation, for example, it can be 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0035] After the fermentation is completed, the moisture content of the tobacco leaves should be adjusted in time. By limiting the supply of free water and blocking the basis of microbial metabolism, the moisture content will decrease, the contact efficiency between the enzyme and the substrate will decrease, and the enzymatic reaction process will be slowed down, slowing down the excessive fermentation of the tobacco leaves. In addition, controlling the moisture content of the tobacco leaves within a specific range can also avoid the occurrence of tobacco leaves that are too low in moisture and break.

[0036] In a second aspect, the present invention provides a cigar tobacco leaf prepared according to the fermentation method of the first aspect.

[0037] In a third aspect, the present invention provides a use of the cigar tobacco leaves according to the second aspect in preparing cigar products.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] In the present invention, a mixed bacterial community of Aspergillus niger, Aspergillus oryzae and Rhizopus strains is used to inoculate cigar tobacco leaves to promote fermentation, so as to achieve enzyme complementarity, cover the production of multiple target enzymes, promote the full degradation of macromolecular substances, and improve the fermentation effect; in addition, the application of the above-mentioned specific mixed bacterial agent can further promote the efficient utilization of carbon and nitrogen sources, enhance the production of flavor substances, enrich the flavor layers of tobacco leaves, and effectively resist miscellaneous bacteria, improve the stability of fermentation, and improve the uniformity and darkening degree of the finally obtained cigar tobacco leaf material. DETAILED DESCRIPTION

[0040] In order to further illustrate the technical means and effects adopted by the present invention, the technical solutions of the present invention are further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0041] The cigar tobacco raw materials involved below are cigar wrapper tobacco leaves, produced in Indonesia, and of the Connecticut variety.

[0042] The preparation method of the bacterial agent involved below is: after activating the strain, inoculate it into the culture medium and culture it until abundant spores are produced, then rinse the surface of the culture medium with sterile saline, collect the spore suspension, filter it, and use a hemocytometer to determine the spore concentration, and mix it according to the corresponding viable cell count ratio (spore count ratio) to obtain the corresponding spore suspension.

[0043] Example 1

[0044] This embodiment provides a fermented cigar tobacco leaf, and the preparation method thereof is as follows:

[0045] (1) Inoculation of composite microbial agents

[0046] The composite bacterial agent (Aspergillus niger CICC 40048 + Aspergillus oryzae CICC 2180 + Rhizopus stolonifer CICC 40900) was sprayed in liquid form, with the ratio of viable bacteria count being 10:10:1, wherein the viable bacteria concentration of Aspergillus niger in the bacterial agent was 1×10 5 CFU / mL) is evenly applied on the surface of the cigar tobacco leaves to be fermented, and the amount of the bacterial agent used is 3% of the mass of the incoming cigars.

[0047] (2) Tobacco leaf fermentation

[0048] The tobacco leaves after application of the composite bacterial agent were piled to a height of 40 cm and a density of 80 kg / m 3 The small piles are placed in a fermentation room with adjustable temperature and humidity for stacking and fermentation. The fermentation includes the following stages in chronological order:

[0049] S1, bacterial growth stage: the fermentation chamber temperature was adjusted to 30°C, the humidity was 85%, and the fermentation period was 2 days;

[0050] S2, enzyme synthesis stage: the fermentation chamber temperature was adjusted to 28°C, the humidity was 75%, and the fermentation period was 3 days;

[0051] S3, macromolecule decomposition stage: the fermentation room temperature is adjusted to 35°C, the humidity is 70%, and the fermentation period is 5 days;

[0052] S4, enzyme activity-driven degradation and flavor formation stage: the fermentation chamber temperature was adjusted to 40°C, the humidity was 70%, and the fermentation period was 7 days;

[0053] S5, non-enzymatic reaction and flavor stabilization stage: the fermentation room temperature is adjusted to 50°C, the humidity is 65%, and the fermentation period is 7 days;

[0054] During the tobacco leaf fermentation process, the stacks are turned over once every 5 days.

[0055] (3) Fermentation ends

[0056] The moisture content of the tobacco leaves was adjusted to 13% to obtain fermented cigar tobacco leaves.

[0057] Example 2

[0058] This embodiment provides a fermented cigar tobacco leaf, and the preparation method thereof is as follows:

[0059] (1) Inoculation of composite microbial agents

[0060] The composite bacterial agent (Aspergillus niger CICC 41254 + Aspergillus oryzae CICC 2165 + Rhizopus chinensis CICC 3091) was sprayed in liquid form, with the ratio of viable bacteria being 1:1:1, wherein the concentration of viable bacteria of Aspergillus niger in the bacterial agent was 5×10 5 CFU / mL) is evenly applied on the surface of the cigar tobacco leaves to be fermented, and the amount of the bacterial agent used is 1% of the mass of the incoming cigars.

[0061] (2) Tobacco leaf fermentation

[0062] The tobacco leaves after application of the composite bacterial agent were piled to a height of 50 cm and a density of 90 kg / m 3 The small piles are placed in a fermentation room with adjustable temperature and humidity for stacking and fermentation. The fermentation includes the following stages in chronological order:

[0063] S1, bacterial growth stage: the fermentation chamber temperature was adjusted to 32°C, the humidity was 88%, and the fermentation period was 3 days;

[0064] S2, enzyme synthesis stage: the fermentation chamber temperature was adjusted to 29°C, the humidity was 78%, and the fermentation period was 4 days;

[0065] S3, macromolecular decomposition stage: the fermentation chamber temperature was adjusted to 36°C, the humidity was 72%, and the fermentation period was 7 days;

[0066] S4, enzyme activity-driven degradation and flavor formation stage: the fermentation chamber temperature was adjusted to 42°C, the humidity was 72%, and the fermentation period was 10 days;

[0067] S5, non-enzymatic reaction and flavor stabilization stage: the fermentation room temperature is adjusted to 52°C, the humidity is 68%, and the fermentation period is 10 days;

[0068] During the tobacco leaf fermentation process, the stacks are turned over once every four days.

[0069] (3) Fermentation ends

[0070] The moisture content of the tobacco leaves was adjusted to 14% to obtain fermented cigar tobacco leaves.

[0071] Example 3

[0072] This embodiment provides a fermented cigar tobacco leaf, and the preparation method thereof is as follows:

[0073] (1) Inoculation of composite microbial agents

[0074] The composite microbial agent (Aspergillus niger CICC 40273 + Aspergillus oryzae CICC 40214 + Rhizopus microsporus CICC 40290, the ratio of viable bacterial numbers is 3:5:0.8, wherein the viable bacterial concentration of Aspergillus niger in the microbial agent is 1×10 6 CFU / mL) is uniformly applied to the surface of the cigar tobacco leaves to be fermented, and the amount of the microbial agent is 5% of the mass of the incoming material.

[0075] (2) Tobacco fermentation

[0076] The tobacco leaves after applying the composite microbial agent are stacked into a small pile with a height of 60 cm and a density of 100 kg / m 3 The pile is placed in a fermentation room with adjustable temperature and humidity for pile fermentation, and the fermentation includes the following stages in chronological order:

[0077] S1, microbial growth stage: the temperature of the fermentation room is adjusted to 34℃, the humidity is adjusted to 90%, and the fermentation period is 4 days;

[0078] S2, enzyme synthesis stage: the temperature of the fermentation room is adjusted to 30℃, the humidity is adjusted to 80%, and the fermentation period is 5 days;

[0079] S3, macromolecular decomposition stage: the temperature of the fermentation room is adjusted to 38℃, the humidity is adjusted to 75%, and the fermentation period is 10 days;

[0080] S4, enzyme activity driven degradation and flavor substance formation stage: the temperature of the fermentation room is adjusted to 45℃, the humidity is adjusted to 74%, and the fermentation period is 12 days;

[0081] S5, non-enzymatic reaction and flavor stabilization stage: the temperature of the fermentation room is adjusted to 55℃, the humidity is adjusted to 69%, and the fermentation period is 10 days;

[0082] During the fermentation of the tobacco leaves, the pile is turned over once every 3 days.

[0083] (3) Fermentation end

[0084] Adjust the moisture content of the tobacco leaves to 15% to obtain fermented cigar tobacco leaves.

[0085] Example 4

[0086] This example provides a fermented cigar tobacco leaf, which is only different from example 1 in that Rhizopus stolonifer CICC 40900 is replaced by an equal amount of composite Rhizopus strains (Rhizopus stolonifer CICC 40900 + Rhizopus chinensis CICC 3091 + Rhizopus microsporus CICC 40290, the ratio of viable bacterial numbers is 1:1:1), and the rest of the process and related parameters are referred to example 1.

[0087] Example 5

[0088] This embodiment provides a fermented cigar tobacco leaf, which differs from Example 2 only in that Rhizopus chinensis CICC 3091 is replaced with an equal amount of a composite Rhizopus strain (Rhizopus stolonifer CICC 40900 + Rhizopus chinensis CICC 3091 + Rhizopus oryzae CICC 40290 with a viable cell count ratio of 5:1:1). The remaining processes and related parameters are the same as those in Example 2.

[0089] Example 6

[0090] This embodiment provides a fermented cigar tobacco leaf, which differs from Example 3 only in that Rhizopus oryzae CICC40290 is replaced with an equal amount of a composite Rhizopus strain (Rhizopus stolonifer CICC40900 + Rhizopus chinensis CICC3091 + Rhizopus oryzae CICC 40290 with a viable cell count ratio of 1:1:3). The remaining processes and related parameters are the same as those in Example 3.

[0091] Example 7

[0092] This embodiment provides a fermented cigar tobacco leaf, which uses the tobacco leaf inoculated with the composite bacterial agent in Example 1. The only difference between this embodiment and Example 1 is that the height of the tobacco pile is 100 cm. The rest of the process and related parameters are the same as those in Example 1.

[0093] Example 8

[0094] This embodiment provides a fermented cigar tobacco leaf, which is the tobacco leaf inoculated with the composite bacterial agent in Example 1. The difference between this embodiment and Example 1 is that the density of the tobacco pile is 150 kg / m 3 The rest of the process and related parameters are referenced to Example 1.

[0095] Example 9

[0096] This embodiment provides a fermented cigar tobacco leaf, which is the tobacco leaf inoculated with the composite bacterial agent in Example 1. The only difference from Example 1 is that the tobacco leaf fermentation adopts a natural fermentation mode, and the temperature and humidity of the fermentation chamber are not additionally regulated. During the fermentation process, the tobacco leaf is turned over once every 5 days. After 24 days of fermentation, the moisture content of the tobacco leaf is adjusted to 13%, thereby obtaining the fermented cigar tobacco leaf.

[0097] Comparative Example 1

[0098] This comparative example provides a fermented cigar tobacco leaf, which differs from Example 1 only in that the Aspergillus niger strain is not inoculated, and the reduced number of Aspergillus niger strains is proportionally distributed to Aspergillus oryzae and Rhizopus stolonifer strains. The remaining processes and related parameters are the same as those in Example 1.

[0099] Comparative Example 2

[0100] This comparative example provides a fermented cigar tobacco leaf, which differs from Example 1 only in that the Aspergillus oryzae strain is not inoculated, and the reduced number of Aspergillus oryzae strains is proportionally distributed to Aspergillus niger and Rhizopus stolonifer strains. The remaining processes and related parameters are the same as those in Example 1.

[0101] Comparative Example 3

[0102] This comparative example provides a fermented cigar tobacco leaf, which differs from Example 1 only in that the Rhizopus genus strain (Rhizopus stolonifer) is not inoculated, and the reduced number of Rhizopus stolonifer is proportionally distributed to Aspergillus niger and Aspergillus oryzae. The remaining processes and related parameters are the same as those in Example 1.

[0103] Test Example 1

[0104] Evaluation of tobacco leaf fermentation quality

[0105] Using a colorimeter (3nh, YS3060) with a D65 light source, the L*a*b* color space (CIE Lab) values ​​of the control group (unfermented cigar tobacco leaf material), fermented cigar tobacco leaf products obtained in Examples 1-9, and Comparative Examples 1-3 were measured. The instrument was calibrated with a standard white plate before each test. The tobacco leaf samples were cleaned and flattened before testing. The measurement points covered the key areas of the leaf (leaf tip, leaf center, leaf base, and both sides of the main vein). Ten measurement points were selected for each tobacco leaf. The coefficient of variation (CV) was (SD / average) × 100%. The results are shown in Table 1.

[0106] Table 1

[0107]

[0108]

[0109] According to the data in the table,

[0110] (1) It can be seen from Examples 1 to 3 that the fermented cigar tobacco leaves obtained by the treatment of the present invention have a high degree of darkening, uniform color, high maturity, and excellent appearance quality.

[0111] (2) By comparing Examples 4-6 with Examples 1-3, it can be seen that when the Rhizopus strains used for fermentation addition are a combination of Rhizopus stolonifer, Rhizopus chinensis, and Rhizopus oryzae, it is found that the fermentation effect can be further improved, and fermented cigar tobacco leaves with a higher degree of darkening can be prepared.

[0112] (3) By comparing Example 1 with Examples 7-8, it can be seen that when the stack height exceeds a certain height or the density of the tobacco stack is too high, the fermentation effect will be affected, and the quality of the fermented cigar tobacco leaves finally prepared will be worse than that of Example 1.

[0113] (4) By comparing Example 1 with Example 9, compared with the conventional natural fermentation method, the specific environmental conditions for different fermentation stages of tobacco fermentation in the present application are set, the temperature and humidity are controlled in stages, and the metabolic characteristics of the microbial population and the biochemical reaction requirements are precisely matched, which can effectively improve the decomposition and fermentation effect of starch, protein and cellulose and other components in tobacco, improve the fermentation efficiency, and prepare fermented tobacco products with excellent appearance quality.

[0114] (5) By comparing Example 1 with Comparative Examples 1-3, the present application uses a complex microbial inoculant including Aspergillus niger, Aspergillus oryzae and Rhizopus strain to inoculate the cigar tobacco, the mixed strains synergize to jointly improve the fermentation treatment effect of the tobacco, which can fully improve the quality of the tobacco material, and prepare high-maturity cigar tobacco products with high darkening degree and uniform color.

[0115] Test Example 2

[0116] In this test example, the cigar tobacco fermented by the process methods provided in Examples 1-9 and Comparative Examples 1-3 is evaluated, wherein each group of tobacco materials is balanced for 72h under the environmental conditions of temperature 25℃ and humidity 72%, and then the relevant evaluation test is carried out, the local circulation evaluation method is adopted, the participants for evaluation are composed of qualified evaluation members, a total of 10 people, the evaluation indexes and scores are shown in Table 2, the minimum score difference is 0.5, and the specific evaluation results are shown in Table 3.

[0117] Table 2

[0118]

[0119] Table 3

[0120] Group Fragrance Aroma volume Miscellaneous gases Irritation Aftertaste sweetness Flammability grey Total score Example 1 14.0 13.0 7.5 8.0 12.5 8.0 8.0 7.0 78.0 Example 2 14.0 13.0 7.5 8.0 12.5 8.0 8.0 7.0 78.0 Example 3 14.0 13.5 7.0 7.5 12.0 8.0 8.0 7.0 77.0 Example 4 14.0 13.5 7.5 8.5 13.0 8.5 8.0 7.0 80.0 Example 5 14.5 13.5 7.5 8.5 12.5 8.5 8.0 7.0 80.0 Example 6 14.0 14.0 8.0 8.5 13.0 8.0 8.0 7.0 80.5 Example 7 14.0 12.5 7.5 7.5 12.0 7.5 8.0 7.0 76.0 Example 8 13.5 12.5 7.0 8.0 12.0 7.5 8.0 7.0 75.5 Example 9 13.5 12.0 7.0 7.5 11.5 7.5 8.0 7.0 74.0 Comparative Example 1 13.0 11.5 6.0 7.5 11.5 7.0 8.0 7.0 71.5 Comparative Example 2 13.0 11.5 6.5 7.0 11.5 7.0 8.0 7.0 71.5 Comparative Example 3 13.0 11.5 6.5 7.5 11.0 7.5 8.0 7.0 72.0

[0121] According to the data in the table, the cigar tobacco material fermented by the treatment process provided in the present application has excellent appearance quality, and also has excellent taste and aroma richness. Among them, the sensory experience effect of the cigar tobacco product treated by Example 1 is better than that of Examples 7-9 and Comparative Examples 1-3, which indicates that the specific cigar tobacco fermentation treatment process conditions adopted in the present application have different degrees of influence on the quality of the finally prepared tobacco material.

[0122] The applicant declares that the technical solutions of the present application are illustrated by the above examples, but the present application is not limited to the above examples, that is, it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the protection scope and disclosure scope of the present application.

[0123] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0124] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A fermentation method for improving the uniformity and darkening of cigar tobacco leaves, characterized in that: The fermentation method includes inoculation of composite bacterial agent, tobacco leaf fermentation and fermentation completion; Among them, the strains in the composite bacterial agent include a combination of Aspergillus niger, Aspergillus oryzae and Rhizopus strains.

2. The fermentation method according to claim 1, characterized in that The ratio of the viable counts of the Aspergillus niger, Aspergillus oryzae and Rhizopus strains is (1-10):(1-10):(0.1-1); Preferably, the Rhizopus strain includes any one of Rhizopus stolonifer, Rhizopus chinensis or Rhizopus oryzae, or a combination of at least two thereof.

3. The fermentation method according to claim 1, characterized in that The total viable bacteria content in the composite bacterial agent is not less than 1×10 5 CFU / mL or 1×10 5 CFU / g.

4. The fermentation method according to claim 1, characterized in that The dosage of the composite bacterial agent is 1%-5% of the mass of the cigar tobacco leaves.

5. The fermentation method according to claim 1, characterized in that The fermentation in the tobacco leaf fermentation stage adopts stacking fermentation; Preferably, the height of the smoke stack in the stack is not higher than 60 cm, and the smoke stack density is 80-100 kg / m 3 .

6. The fermentation method according to claim 1, characterized in that The tobacco leaf fermentation is carried out in stages, which specifically include the following stages in chronological order: S1, bacterial growth stage: adjust the fermentation room temperature to 30-35°C, humidity to 85%-90%, and fermentation cycle to 2-4 days; S2, enzyme synthesis stage: adjust the fermentation room temperature to 28-30°C, humidity to 75%-80%, and fermentation cycle to 3-5 days; S3, macromolecule decomposition stage: adjust the fermentation room temperature to 35-38°C, humidity to 70%-75%, and the fermentation period to 5-10 days; S4, enzyme activity-driven degradation and flavor formation stage: the fermentation chamber temperature is adjusted to 40-45°C, the humidity is 70%-75%, and the fermentation cycle is 7-14 days; S5, non-enzymatic reaction and flavor stabilization stage: adjust the temperature of the fermentation room to 50-55°C, the humidity to 65%-70%, and the fermentation period to 7-14 days.

7. The fermentation method according to claim 1, characterized in that During the tobacco leaf fermentation, stacking is also performed; Preferably, the frequency of stacking is once every 3-5 days.

8. The fermentation method according to claim 1, characterized in that At the end of the fermentation, the moisture content of the tobacco leaves is adjusted to 13%-16%.

9. Cigar tobacco leaves prepared according to the fermentation method according to any one of claims 1 to 8.

10. Use of the cigar tobacco leaf according to claim 9 in preparing cigar products.

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