Method for preventing mildewing during fermentation of cigar tobacco leaves

Abstract

The invention belongs to the technical field of tobacco leaf processing, and relates to a cigar tobacco leaf fermentation anti-mildew method which comprises the following steps: (1) preparing a beta-cyclodextrin-litsea cubeba oil inclusion compound; (2) dissolving the beta-cyclodextrin-litsea cubeba oil clathrate compound obtained in the step (1) in water, and uniformly spraying the dissolved beta-cyclodextrin-litsea cubeba oil clathrate compound on the surfaces of cigar tobacco leaves; and (3) fermenting the cigar tobacco leaves obtained in the step (2) in a constant-temperature and constant-humidity environment. According to the invention, the beta-cyclodextrin-litsea cubeba oil inclusion compound is used in the fermentation scene of the cigar tobacco leaves, so that the growth of mould in the fermentation process of the cigar tobacco leaves is effectively inhibited, the mould rate is reduced by 85% or more, meanwhile, the sensory quality of the cigar tobacco leaves is remarkably improved, the sweet and moist feeling and the body fluid engendering feeling are increased, and the irritation and offensive odor are reduced; the industrial availability and the economic value of the tobacco leaves are improved.

Description

Technical Field

[0001] This invention belongs to the field of tobacco processing technology and relates to a method for preventing mold growth during the fermentation of cigar tobacco leaves. Background Technology

[0002] Fermentation of cigar tobacco leaves is the core process that determines their quality. This process, through the metabolic activities of microorganisms (such as yeast, acetic acid bacteria, and lactic acid bacteria), breaks down large molecules in the tobacco leaves, such as starch, protein, and polyphenols, into smaller molecules like sugars, amino acids, and organic acids—flavor precursors. Simultaneously, it degrades irritating components like nicotine and tar precursors, ultimately forming the unique aroma, taste, and combustibility of cigars. However, the fermentation process has stringent environmental requirements, needing to maintain a temperature of 20-40℃ and a relative humidity of 70%-80%. This temperature and humidity range coincides with the optimal growth environment for molds (such as Aspergillus, Penicillium, and Candida), making it a "natural breeding ground" for tobacco leaf mold.

[0003] Mold contamination has multifaceted harmful effects on cigar tobacco leaves: in terms of appearance, mold mycelium can cause gray-green, dark brown, and other mold spots on the surface of the tobacco leaves, leading to a decline in the grade of the tobacco leaves; in terms of quality, mold metabolism produces off-flavor substances such as organic acids and alcohols, which destroy the original flavor system. At the same time, some molds (such as Aspergillus flavus) can secrete fungal toxins, which, if remaining in the finished cigars, will pose a potential threat to the health of consumers.

[0004] To address the problem of mold growth, the industry's current technology mainly relies on chemical preservatives, among which natamycin (such as CN101797071A) is widely used. However, this type of chemical antibacterial agent has significant technical drawbacks: First, it has a narrow antibacterial spectrum. Natamycin only has inhibitory activity against fungi and has no antibacterial effect on Gram-positive bacteria (such as Bacillus) and Gram-negative bacteria (such as excessive strains of acetic acid bacteria) that proliferate during fermentation. Although some tobacco leaves do not develop mold, they become sticky and have a rancid odor due to bacterial decay. Second, it has poor safety and flavor compatibility. Chemical preservatives are prone to leaving residues in tobacco leaves, which does not conform to the tobacco industry's development trend of "reducing harm and tar, and promoting green and safe products." Furthermore, some preservatives can react chemically with flavor substances in tobacco leaves, producing a chemical astringent taste, destroying the unique natural aroma of cigars, and reducing the product's market acceptance.

[0005] Natural plant essential oils, possessing both antibacterial activity and natural properties, have become a potential alternative to chemical preservatives, with Litsea cubeba oil showing outstanding advantages. Litsea cubeba oil is an essential oil extracted from the fruit of Litsea cubeba, and its main active components are citral and limonene. Citral can disrupt the phospholipid bilayer of microbial cell membranes, causing leakage of cell contents, thus achieving broad-spectrum antibacterial activity (inhibiting 14 types of Gram-positive / negative bacteria and 2 types of pathogenic fungi). Limonene, on the other hand, has antioxidant activity, scavenging free radicals generated during fermentation and delaying the oxidative deterioration of tobacco leaves. However, the physicochemical properties of Litsea cubeba oil make it difficult to directly apply to cigar tobacco fermentation: on the one hand, its molecular structure contains a large number of unsaturated double bonds and aldehyde groups, which are easily oxidized and decomposed under high temperature and humidity conditions, leading to a rapid loss of antibacterial activity; on the other hand, Litsea cubeba oil has a low boiling point (approximately 228℃) and high volatility, failing to provide sustained antibacterial protection for tobacco leaves, resulting in a risk of mold growth even in the later stages of fermentation.

[0006] Furthermore, cyclodextrin inclusion technology, a commonly used essential oil stabilization technique in the food and cosmetics industries, has been proven to reduce the volatility and oxidative properties of essential oil molecules by encapsulating them in a cavity structure with an internal hydrophobic and external hydrophilic properties. However, to date, no research has applied β-cyclodextrin inclusion of Litsea cubeba oil to cigar tobacco fermentation. How to optimize the inclusion process parameters to ensure that the inclusion compound is suitable for the fermentation environment of cigar tobacco while also achieving antibacterial effects and improved sensory quality is a key technical problem that this invention urgently needs to solve. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a method for preventing mold growth during cigar tobacco fermentation. This method involves encapsulating β-cyclodextrin with Litsea cubeba oil and applying it to the fermentation process of cigar tobacco leaves, effectively inhibiting mold growth during fermentation and improving the sensory quality of the cigar tobacco leaves.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] This invention provides a method for preventing mold growth during the fermentation of cigar tobacco leaves, comprising the following steps:

[0010] (1) Preparation of β-cyclodextrin-Litsea cubeba oil inclusion complex;

[0011] (2) Dissolve the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in step (1) in water and then spray it evenly on the surface of cigar tobacco leaves;

[0012] (3) Place the cigar tobacco leaves obtained in step (2) in a constant temperature and humidity environment for fermentation.

[0013] This invention utilizes a β-cyclodextrin-Litsea cubeba oil inclusion complex in cigar tobacco fermentation, effectively inhibiting mold growth during fermentation and reducing mold rates by over 85%. Furthermore, the cyclodextrin inclusion technology addresses the volatility and instability of Litsea cubeba oil, enabling its slow release and extending the duration of its antibacterial effect. Simultaneously, the addition of Litsea cubeba oil not only inhibits mold growth but also significantly improves the sensory quality of cigar tobacco, increasing sweetness and savory sensation, reducing irritation, and enhancing the overall quality and usability of the tobacco.

[0014] Furthermore, this invention uses natural plant essential oils to replace traditional chemical preservatives, eliminating the risk of chemical residues and making it safer and more reliable. It aligns with the green development strategy of the tobacco industry, and the preparation process requires only conventional equipment, resulting in low cost. The inclusion compound exhibits good stability, is easy to store and transport, and can be directly adapted to existing cigar tobacco fermentation production lines, making it suitable for large-scale promotion.

[0015] Preferably, the preparation method of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (1) includes the following steps:

[0016] (1.1) Mix β-cyclodextrin, hydroxypropyl-β-cyclodextrin and solvent to prepare a saturated cyclodextrin solution;

[0017] (1.2) Add Litsea cubeba oil dropwise to the saturated cyclodextrin solution obtained in step (1.1), and stir until homogeneous to obtain an intermediate solution;

[0018] (1.3) The intermediate solution obtained in step (1.2) is subjected to ultrasonic treatment, and a precipitate is formed after standing.

[0019] (1.4) Separate the precipitate obtained in step (1.3), and wash, dry and sieve it in sequence to obtain β-cyclodextrin-Litsea cubeba oil inclusion complex.

[0020] Preferably, the mass ratio of β-cyclodextrin and hydroxypropyl-β-cyclodextrin in step (1.1) is (1-8):1, and more preferably (3-4):1.

[0021] Preferably, the solvent in step (1.1) includes distilled water.

[0022] Preferably, the components of the Litsea cubeba oil in step (1.2) include limonene and citral.

[0023] Preferably, based on the total mass of Litsea cubeba oil, the content of limonene is 20-25 wt%, and the content of citral is 55-60 wt%.

[0024] Preferably, the mass ratio of Litsea cubeba oil to β-cyclodextrin is 1:(6-12), and more preferably 1:(7-9).

[0025] Preferably, the intermediate solution in step (1.2) comprises, by mass percentage: 5-15 wt% Litsea cubeba oil, 20-40 wt% β-cyclodextrin, 5-15 wt% hydroxypropyl-β-cyclodextrin, and 40-70 wt% distilled water.

[0026] Preferably, the temperature of the droplet addition in step (1.2) is 30-50°C.

[0027] Preferably, the stirring speed in step (1.2) is 800-1200 rpm.

[0028] Preferably, the stirring time in step (1.2) is 1-4 hours.

[0029] Preferably, the temperature of the ultrasonic treatment in step (1.3) is 45-60℃.

[0030] Preferably, the ultrasonic treatment time in step (1.3) is 15-30 min.

[0031] Preferably, the temperature for standing in step (1.3) is 20-25°C.

[0032] Preferably, the settling time in step (1.3) is 24-48 hours.

[0033] Preferably, the separation method in step (1.4) includes vacuum filtration.

[0034] Preferably, the detergent used in step (1.4) includes distilled water.

[0035] Preferably, the drying method in step (1.4) includes vacuum drying, with a drying temperature of 50-60°C and a drying time of 24-48 hours.

[0036] Preferably, the sieve used in step (1.4) has a mesh size of 20-40.

[0037] Preferably, the inclusion rate of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (1) is ≥82%.

[0038] Preferably, the amount of β-cyclodextrin-Litsea cubeba oil inclusion complex in step (2) is 0.5-5 mg / g, based on the mass of cigar tobacco leaves.

[0039] Preferably, the temperature of the constant temperature and humidity environment in step (3) is 32-35℃ and the relative humidity is 75%-80%.

[0040] Preferably, the fermentation cycle in step (3) is 10-20 days.

[0041] Preferably, the cigar tobacco leaves are removed and equilibrated in a constant temperature and humidity chamber, and the appearance and sensory quality of the cigar tobacco leaves are evaluated in turn.

[0042] Preferably, the temperature and humidity chamber is set to 20-25℃ and the relative humidity is 50%-70%.

[0043] Preferably, the balancing process takes 36-48 hours.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) This invention utilizes a β-cyclodextrin-Litsea cubeba oil inclusion complex in the fermentation process of cigar tobacco leaves, effectively inhibiting mold growth during fermentation and reducing the mold rate by more than 85%. Furthermore, the cyclodextrin inclusion complex technology solves the problems of volatility and instability of Litsea cubeba oil, enabling its slow release and extending the antibacterial effect. Simultaneously, the addition of Litsea cubeba oil not only inhibits mold growth but also significantly improves the sensory quality of cigar tobacco leaves, increasing sweetness and saliva production, reducing irritation, and enhancing the quality and usability of the tobacco.

[0046] (2) This invention uses natural plant essential oils to replace traditional chemical preservatives, which eliminates the risk of chemical residues, making it safer and more reliable. It is in line with the green development of the tobacco industry. Moreover, the preparation process only requires conventional equipment, which is inexpensive. The inclusion compound has good stability and is easy to store and transport. It can be directly adapted to existing cigar tobacco fermentation production lines and has the conditions for large-scale promotion. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0048] One embodiment of the present invention provides a method for preventing mold growth during the fermentation of cigar tobacco leaves, comprising the following steps:

[0049] (1) Preparation of β-cyclodextrin-Litsea cubeba oil inclusion complex;

[0050] (2) Dissolve the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in step (1) in water and then spray it evenly on the surface of cigar tobacco leaves;

[0051] (3) Place the cigar tobacco leaves obtained in step (2) in a constant temperature and humidity environment for fermentation.

[0052] This invention utilizes a β-cyclodextrin-Litsea cubeba oil inclusion complex in cigar tobacco fermentation, effectively inhibiting mold growth during fermentation and reducing mold rates by over 85%. Furthermore, the cyclodextrin inclusion technology addresses the volatility and instability of Litsea cubeba oil, enabling its slow release and extending the duration of its antibacterial effect. Simultaneously, the addition of Litsea cubeba oil not only inhibits mold growth but also significantly improves the sensory quality of cigar tobacco, increasing sweetness and savory sensation, reducing irritation, and enhancing the overall quality and usability of the tobacco.

[0053] Furthermore, this invention uses natural plant essential oils to replace traditional chemical preservatives, eliminating the risk of chemical residues and making it safer and more reliable. It aligns with the green development strategy of the tobacco industry, and the preparation process requires only conventional equipment, resulting in low cost. The inclusion compound exhibits good stability, is easy to store and transport, and can be directly adapted to existing cigar tobacco fermentation production lines, making it suitable for large-scale promotion.

[0054] In some embodiments, the preparation method of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (1) includes the following steps:

[0055] (1.1) Mix β-cyclodextrin, hydroxypropyl-β-cyclodextrin and solvent to prepare a saturated cyclodextrin solution;

[0056] (1.2) Add Litsea cubeba oil dropwise to the saturated cyclodextrin solution obtained in step (1.1), and stir until homogeneous to obtain an intermediate solution;

[0057] (1.3) The intermediate solution obtained in step (1.2) is subjected to ultrasonic treatment, and a precipitate is formed after standing.

[0058] (1.4) Separate the precipitate obtained in step (1.3), and wash, dry and sieve it in sequence to obtain β-cyclodextrin-Litsea cubeba oil inclusion complex.

[0059] In some embodiments, the mass ratio of β-cyclodextrin and hydroxypropyl-β-cyclodextrin in step (1.1) is (1-8):1, for example, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1, and is more preferably (3-4):1, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0060] In some embodiments, the solvent in step (1.1) includes distilled water.

[0061] In some embodiments, the components of the Litsea cubeba oil in step (1.2) include limonene and citral.

[0062] In some embodiments, the total mass of Litsea cubeba oil is used as the calculation basis, and the limonene content is 20-25 wt%, for example, it can be 20 wt%, 20.5 wt%, 21 wt%, 21.5 wt%, 22 wt%, 22.5 wt%, 23 wt%, 23.5 wt%, 24 wt%, 24.5 wt%, or 25 wt%, and the citral content is 55-60 wt%, for example, it can be 55 wt%, 55.5 wt%, 56 wt%, 56.5 wt%, 57 wt%, 57.5 wt%, 58 wt%, 58.5 wt%, 59 wt%, 59.5 wt%, or 60 wt%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0063] In some embodiments, the mass ratio of Litsea cubeba oil to β-cyclodextrin is 1:(6-12), for example, it can be 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, 1:10.5, 1:11, 1:11.5 or 1:12, and more preferably 1:(7-9), but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0064] In some embodiments, the intermediate solution in step (1.2) comprises, by mass percentage: 5-15 wt% of Litsea cubeba oil, for example, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt%; and 20-40 wt% of β-cyclodextrin, for example, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt%, or 36 wt%. 38 wt% or 40 wt%, hydroxypropyl-β-cyclodextrin 5-15 wt%, for example, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt% or 15 wt%, distilled water 40-70 wt%, for example, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt% or 70 wt%, but not limited to the listed values, other unlisted values ​​within this range also apply.

[0065] In some embodiments, the temperature of the droplet added in step (1.2) is 30-50°C, for example, it can be 30°C, 35°C, 40°C, 45°C or 50°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0066] In some embodiments, the stirring speed in step (1.2) is 800-1200 rpm, for example, it can be 800 rpm, 850 rpm, 900 rpm, 950 rpm, 1000 rpm, 1050 rpm, 1100 rpm, 1150 rpm or 1200 rpm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0067] In some embodiments, the stirring time in step (1.2) is 1-4 hours, for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0068] In some embodiments, the temperature of the ultrasonic treatment in step (1.3) is 45-60°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0069] In some embodiments, the ultrasonic treatment time in step (1.3) is 15-30 min, for example, it can be 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min or 30 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0070] In some embodiments, the settling temperature in step (1.3) is 20-25°C, for example, it can be 20°C, 21°C, 22°C, 23°C, 24°C or 25°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0071] In some embodiments, the settling time in step (1.3) is 24-48h, for example, it can be 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h or 48h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0072] In some embodiments, the separation method described in step (1.4) includes vacuum filtration.

[0073] In some embodiments, the detergent used in step (1.4) includes distilled water.

[0074] In some embodiments, the drying method described in step (1.4) includes vacuum drying, and the drying temperature is 50-60°C, for example, 50°C, 51°C, 52°C, 53°C, 54°C, 56°C, 57°C, 58°C, 59°C or 60°C, and the drying time is 24-48h, for example, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h or 48h, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0075] In some embodiments, the sieving specification in step (1.4) is 20-40 mesh, for example, it can be 20 mesh, 22 mesh, 24 mesh, 26 mesh, 28 mesh, 30 mesh, 32 mesh, 34 mesh, 36 mesh, 38 mesh or 40 mesh, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0076] In some embodiments, the inclusion rate of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (1) is ≥82%, for example, it can be 82%, 82.5%, 83%, 83.5%, 84%, 84.5% or 85%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0077] In some embodiments, the mass of cigar tobacco leaves is used as the calculation basis, and the spraying amount of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (2) is 0.5-5 mg / g, for example, it can be 0.5 mg / g, 1 mg / g, 1.5 mg / g, 2 mg / g, 2.5 mg / g, 3 mg / g, 3.5 mg / g, 4 mg / g, 4.5 mg / g or 5 mg / g, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0078] In some embodiments, the temperature of the constant temperature and humidity environment in step (3) is 32-35℃, for example, it can be 32℃, 32.5℃, 33℃, 33.5℃, 34℃, 34.5℃ or 35℃, and the relative humidity is 75%-80%, for example, it can be 75%, 76%, 77%, 78%, 79% or 80%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0079] In some embodiments, the fermentation cycle in step (3) is 10-20 days, for example, it can be 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days or 20 days, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0080] In some embodiments, the cigar tobacco leaves are removed and equilibrated in a constant temperature and humidity chamber, and the appearance and sensory quality of the cigar tobacco leaves are evaluated in turn.

[0081] In some embodiments, the set temperature of the constant temperature and humidity chamber is 20-25℃, for example, it can be 20℃, 20.5℃, 21℃, 21.5℃, 22℃, 22.5℃, 23℃, 23.5℃, 24℃, 24.5℃ or 25℃, and the relative humidity is 50%-70%, for example, it can be 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68% or 70%, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0082] In some embodiments, the balancing process takes 36-48 hours, for example, 36 hours, 38 hours, 40 hours, 42 hours, 44 hours, 46 hours, or 48 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0083] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0084] Preparation Example 1

[0085] This preparation example provides a method for preparing a β-cyclodextrin-Litsea cubeba oil inclusion complex, comprising the following steps:

[0086] (1) Take 30g of a mixture of β-cyclodextrin and hydroxypropyl-β-cyclodextrin in a mass ratio of 4:1 and dissolve it in 300g of distilled water to prepare a saturated cyclodextrin solution;

[0087] (2) At 40°C, 6g of Litsea cubeba oil (main components: limonene 23.74wt%, citral 57.98wt%) was added dropwise to the saturated cyclodextrin solution obtained in step (1), and stirred at 1000rpm for 3h to obtain an intermediate solution;

[0088] (3) The intermediate solution obtained in step (2) was ultrasonically treated at 50°C for 20 min, and then allowed to stand at 25°C for 24 h to precipitate.

[0089] (4) The precipitate obtained in step (3) was filtered, washed with 100 mL of distilled water, placed in a vacuum drying oven at 55 °C for 36 h, and then sieved through a 30 mesh to obtain the β-cyclodextrin-Litsea cubeba oil inclusion complex.

[0090] The encapsulation efficiency of the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in this preparation example was determined to be 82.3%.

[0091] Preparation Example 2

[0092] This preparation example provides a method for preparing a β-cyclodextrin-Litsea cubeba oil inclusion complex, comprising the following steps:

[0093] (1) Take 40g of a mixture of β-cyclodextrin and hydroxypropyl-β-cyclodextrin in a mass ratio of 3:1 and dissolve it in 400g of distilled water to prepare a saturated cyclodextrin solution;

[0094] (2) At 45°C, 8g of Litsea cubeba oil (main components: limonene 23.74wt%, citral 57.98wt%) was added dropwise to the saturated cyclodextrin solution obtained in step (1), and stirred at 1200rpm for 2h to obtain an intermediate solution;

[0095] (3) The intermediate solution obtained in step (2) was ultrasonically treated at 50°C for 20 min, and then allowed to stand at 25°C for 36 h to precipitate.

[0096] (4) The precipitate obtained in step (3) was filtered, washed with 120 mL of distilled water, placed in a vacuum drying oven at 50 °C for 48 h, and then sieved through a 40 mesh to obtain the β-cyclodextrin-Litsea cubeba oil inclusion complex.

[0097] The encapsulation efficiency of the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in this preparation example was determined to be 84.1%.

[0098] Application Example 1

[0099] In this application example, the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in Example 1 was used in the fermentation process of cigar tobacco leaves: the β-cyclodextrin-Litsea cubeba oil inclusion complex was dissolved in water and then sprayed evenly on the surface of the cigar tobacco leaves at an addition rate of 2 mg / g. The tobacco leaves were then placed in a fermentation chamber and fermented for 20 days at a temperature of 33±2℃ and a relative humidity of 78±2%.

[0100] Application Example 2

[0101] In this application example, the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in Preparation Example 2 was used in the fermentation process of cigar tobacco leaves: the β-cyclodextrin-Litsea cubeba oil inclusion complex was dissolved in water and then sprayed evenly on the surface of the cigar tobacco leaves at an addition rate of 2 mg / g. The tobacco leaves were then placed in a fermentation chamber and fermented for 20 days at a temperature of 33±2℃ and a relative humidity of 78±2%.

[0102] Comparative Example 1

[0103] This comparative example directly describes the cigar tobacco fermentation process: the cigar tobacco leaves are placed in a fermentation chamber and fermented for 20 days at a temperature of 33±2℃ and a relative humidity of 78±2%.

[0104] Comparative Example 2

[0105] In this comparative example, unencapsulated Litsea cubeba oil was directly used in the fermentation process of cigar tobacco leaves: the unencapsulated Litsea cubeba oil (main components: limonene 23.74wt%, citral 57.98wt%) was dissolved in water and then sprayed evenly on the surface of the cigar tobacco leaves at an addition rate of 2mg / g. The tobacco leaves were then placed in a fermentation chamber and fermented for 20 days at a temperature of 33±2℃ and a relative humidity of 78±2%.

[0106] Comparative Example 3

[0107] This comparative example uses commercially available chemical antifungal agent natamycin in the fermentation process of cigar tobacco leaves: Natamycin is dissolved in water and sprayed evenly on the surface of cigar tobacco leaves at an addition rate of 2 mg / g. The tobacco leaves are then placed in a fermentation chamber and fermented for 20 days at a temperature of 33±2℃ and a relative humidity of 78±2%.

[0108] Effect evaluation

[0109] (1) Evaluation of antibacterial effect: The formation of mold colonies on the surface of tobacco leaves was tested every 5 days, and the mold contamination rate was calculated.

[0110] (2) Sensory quality evaluation: Ten professional tasters were invited to conduct sensory evaluation of the fermented tobacco leaves.

[0111] (3) Stability test: After being placed at 40℃ for 30 days, the volatilization characteristics of each application example and comparative example during the fermentation process were compared by weighing and analysis, and the volatilization loss rate was calculated.

[0112] The relevant evaluation results are shown in Table 1 below.

[0113] Table 1

[0114]

[0115] Therefore, this invention, by applying the β-cyclodextrin-Litsea cubeba oil inclusion complex to cigar tobacco fermentation, effectively inhibits mold growth during the fermentation process, reducing the mold rate by more than 85%. Furthermore, the cyclodextrin inclusion technology solves the problems of volatility and instability of Litsea cubeba oil, enabling its slow release and extending the duration of its antibacterial effect. Simultaneously, the addition of Litsea cubeba oil not only inhibits mold growth but also significantly improves the sensory quality of cigar tobacco, increasing sweetness and savory sensation, reducing irritation, and enhancing the overall quality and usability of the tobacco.

[0116] Furthermore, this invention uses natural plant essential oils to replace traditional chemical preservatives, eliminating the risk of chemical residues and making it safer and more reliable. It aligns with the green development strategy of the tobacco industry, and the preparation process requires only conventional equipment, resulting in low cost. The inclusion compound exhibits good stability, is easy to store and transport, and can be directly adapted to existing cigar tobacco fermentation production lines, making it suitable for large-scale promotion.

[0117] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preventing mold growth during the fermentation of cigar tobacco leaves, characterized in that, Includes the following steps: (1) Preparation of β-cyclodextrin-Litsea cubeba oil inclusion complex; (2) Dissolve the β-cyclodextrin-Litsea cubeba oil inclusion complex obtained in step (1) in water and then spray it evenly on the surface of cigar tobacco leaves; (3) Place the cigar tobacco leaves obtained in step (2) in a constant temperature and humidity environment for fermentation.

2. The method for preventing mold growth during cigar tobacco fermentation according to claim 1, characterized in that, The preparation method of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (1) includes the following steps: (1.1) Mix β-cyclodextrin, hydroxypropyl-β-cyclodextrin and solvent to prepare a saturated cyclodextrin solution; (1.2) Add Litsea cubeba oil dropwise to the saturated cyclodextrin solution obtained in step (1.1), and stir until homogeneous to obtain an intermediate solution; (1.3) The intermediate solution obtained in step (1.2) is subjected to ultrasonic treatment, and a precipitate is formed after standing. (1.4) Separate the precipitate obtained in step (1.3), and wash, dry and sieve it in sequence to obtain β-cyclodextrin-Litsea cubeba oil inclusion complex.

3. The method for preventing mold growth during cigar tobacco fermentation according to claim 2, characterized in that, The mass ratio of β-cyclodextrin and hydroxypropyl-β-cyclodextrin in step (1.1) is (1-8):1, and more preferably (3-4):1; And / or, the solvent in step (1.1) includes distilled water.

4. The method for preventing mold growth during cigar tobacco fermentation according to claim 3, characterized in that, The components of the Litsea cubeba oil mentioned in step (1.2) include limonene and citral; And / or, based on the total mass of Litsea cubeba oil, the content of limonene is 20-25 wt%, and the content of citral is 55-60 wt%; And / or, the mass ratio of Litsea cubeba oil to β-cyclodextrin is 1:(6-12), more preferably 1:(7-9).

5. The method for preventing mold growth during cigar tobacco fermentation according to claim 4, characterized in that, The intermediate solution described in step (1.2) comprises, by mass percentage: 5-15 wt% Litsea cubeba oil, 20-40 wt% β-cyclodextrin, 5-15 wt% hydroxypropyl-β-cyclodextrin, and 40-70 wt% distilled water.

6. The method for preventing mold growth during cigar tobacco fermentation according to any one of claims 2-5, characterized in that, The temperature at which the drops are added in step (1.2) is 30-50℃; And / or, the stirring speed in step (1.2) is 800-1200 rpm; And / or, the stirring time in step (1.2) is 1-4 hours.

7. The method for preventing mold growth during cigar tobacco fermentation according to any one of claims 2-5, characterized in that, The temperature for ultrasonic treatment in step (1.3) is 45-60℃; And / or, the duration of the ultrasonic treatment in step (1.3) is 15-30 min; And / or, the settling temperature in step (1.3) is 20-25°C; And / or, the settling time described in step (1.3) is 24-48 hours.

8. The method for preventing mold growth during cigar tobacco fermentation according to any one of claims 2-5, characterized in that, The separation method described in step (1.4) includes vacuum filtration; And / or, the detergent used in step (1.4) includes distilled water; And / or, the drying method described in step (1.4) includes vacuum drying, with a drying temperature of 50-60°C and a drying time of 24-48h; And / or, the sieve used in step (1.4) is 20-40 mesh.

9. The method for preventing mold growth during cigar tobacco fermentation according to claim 1, characterized in that, The encapsulation efficiency of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (1) is ≥82%; And / or, based on the mass of cigar tobacco leaves, the application rate of the β-cyclodextrin-Litsea cubeba oil inclusion complex in step (2) is 0.5-5 mg / g; And / or, the temperature of the constant temperature and humidity environment in step (3) is 32-35℃, and the relative humidity is 75%-80%; And / or, the fermentation cycle described in step (3) is 10-20 days.

10. The method for preventing mold growth during cigar tobacco fermentation according to claim 1, characterized in that, After fermentation, the cigar tobacco leaves were removed and equilibrated in a constant temperature and humidity chamber. The appearance and sensory quality of the cigar tobacco leaves were evaluated in turn. The temperature and humidity chamber is set at 20-25℃ and relative humidity at 50%-70%. And / or, the balancing process takes 36-48 hours.

Images