Preparation method of tobacco essence flavor rich in flavonoids and chlorogenic acid and application thereof in cigarettes

Abstract

This invention belongs to the field of tobacco flavoring and fragrance production technology, specifically relating to a method for preparing tobacco flavoring and fragrance rich in flavonoids and chlorogenic acid, and its application in cigarettes. The main preparation method involves first preparing tobacco flavoring and fragrance from waste tobacco raw materials, and then using an emulsion membrane separation method to obtain tobacco flavoring and fragrance rich in flavonoids and chlorogenic acid. The method for preparing tobacco flavoring and fragrance rich in flavonoids and chlorogenic acid provided by this invention is the first to employ emulsion membrane technology to separate and enrich flavonoids and chlorogenic acid substances in tobacco raw materials such as waste tobacco leaves, tobacco dust, tobacco leaf fragments, and tobacco stems. This overcomes the problems of complex and low yields in traditional processes, and the inapplicability of traditional emulsion membrane separation methods to tobacco due to the use of toxic organic solvents.

Description

Technical Field

[0001] This invention belongs to the field of tobacco flavoring and fragrance production technology, specifically relating to a method for preparing tobacco flavoring and fragrance rich in flavonoids and chlorogenic acid and its application in cigarettes. Background Technology

[0002] The chemical components and their content in tobacco are the main factors determining the intrinsic sensory quality of tobacco. Flavonoids and chlorogenic acid not only play an important role in the physiological and biochemical activities of tobacco, but are also closely related to the aroma, color, and quality of tobacco leaves. They are important latent aroma substances that affect the quality of flue-cured tobacco. They are a crucial factor in evaluating the sensory quality characteristics of tobacco and determine the aroma style of flue-cured tobacco.

[0003] Flavonoids are important precursors of tobacco aroma, with rutin being the most abundant. During tobacco ripening, conditioning, aging, and combustion, rutin can be transformed into aroma compounds through enzymatic reactions, oxidation under high temperature and humidity conditions, rearrangement, and cleavage. The accumulation, transformation, and degradation of these latent aroma compounds during tobacco growth, ripening, conditioning, aging, and combustion generate diphenols and furfural derivatives, directly affecting the aroma of the smoke. These derivatives can impart a sweet and roasted aroma, directly influencing the aroma style, quality, and quantity of tobacco. Chlorogenic acid, a phenylpropanoid compound, is the most abundant polyphenol in tobacco leaves, accounting for 75-90% of the total polyphenol content. Chlorogenic acid shows a significant positive correlation with the aroma quality, quantity, irritation, aftertaste, sweetness, and permeability of cigarettes. Increasing the chlorogenic acid content in tobacco can improve its aroma and permeability, enhance taste, and reduce irritation. It plays a crucial role in improving the quality of tobacco products. Therefore, the content of flavonoids and chlorogenic acid is related to the grade of tobacco leaves, with high-quality tobacco leaves containing higher levels of flavonoids and chlorogenic acid.

[0004] Tobacco flavorings and fragrances are mostly extracted and prepared from tobacco waste. However, the content of effective chemical components such as flavonoids and chlorogenic acid in waste tobacco leaves, tobacco dust, tobacco fragments, and tobacco stems is much lower than that in high-quality tobacco leaves. Therefore, it is quite difficult to enrich these components to obtain higher purity flavonoids and chlorogenic acid. Currently, methods for separating and enriching flavonoids and chlorogenic acid mainly include ultrasonic extraction, organic solvent extraction, supercritical fluid extraction, column chromatography, preparative chromatography, macroporous resin adsorption, and enzymatic methods. However, these methods are often complex, difficult to process, have low extraction rates, high energy consumption, low economic efficiency, and significant environmental pollution, ultimately yielding low levels of effective components, making them unsuitable for large-scale production.

[0005] Liquid membrane separation technology uses a very thin liquid that mimics the structure of a biological membrane. It utilizes the principle of selective permeability and the concentration difference of solutes on both sides of the membrane as the mass transfer driving force, so that the substances to be separated in the external phase of the feed liquid are enriched and concentrated in the internal phase of the membrane, thereby separating the substances to be separated. However, because the organic solvents currently used in emulsion liquid membrane separation are toxic, they are not suitable for use in tobacco additives, which limits the application of this method in cigarette flavorings and fragrances.

[0006] To address the above problems, this invention is proposed. Summary of the Invention

[0007] The first aspect of this invention provides a method for preparing tobacco flavoring rich in flavonoids and chlorogenic acid, comprising the following steps:

[0008] (1) Add 20-95% ethanol solution to tobacco raw material, perform hot reflux extraction at 50-80℃, and filter to obtain tobacco extract;

[0009] (2) The tobacco extract obtained in step (1) is concentrated under vacuum at 60-70℃ to a density of 1.2-1.3 g / cm³. 3 Tobacco concentrate was obtained;

[0010] (3) Add an appropriate amount of acid to the tobacco concentrate obtained in step (2), adjust the pH value to 4-5, filter, and the resulting filtrate is the external aqueous phase solution. The filtration can be done by means of filter cloth, etc.

[0011] (4) Mix the surfactant, carrier and oil phase, add the internal aqueous phase solution, place in an emulsification container and stir at a speed of 3000-10000 r / min to obtain a stable W / O / W type emulsion.

[0012] (5) Mix the external aqueous solution from step (3) with the W / O / W emulsion obtained in step (4) until homogeneous, stir at 100-400 r / min for 10-40 min, let stand for 10-60 min until the emulsion separates into layers and the emulsion phase and aqueous phase.

[0013] (6) The emulsion obtained in step (5) is microfiltered at room temperature and under the condition of 0.08-0.12 MPa through a microfiltration membrane module. After the filtrate is allowed to stand and separate into layers, the oil phase can be recovered and reused, and the aqueous phase filtrate is collected for later use.

[0014] (7) Add acid to the aqueous filtrate obtained in step (6) to adjust the pH to 7-7.5, add 10% propylene glycol by mass, and concentrate under vacuum at 60-70℃ to a density of 1.0-1.3 g / cm³. 3 This yields tobacco flavorings rich in flavonoids and chlorogenic acid.

[0015] Preferably, the tobacco raw material in step (1) is selected from one or more of waste tobacco leaves, tobacco dust, tobacco leaf fragments, and tobacco stems; the mass ratio of the extracted tobacco raw material to ethanol is 1:5-1:25, and the process can be repeated multiple times, preferably twice, with each extraction lasting 1-4 hours.

[0016] Preferably, the acid solution mentioned in steps (3) and (7) is selected from one or more of hydrochloric acid, lactic acid, malic acid, citric acid and benzoic acid.

[0017] The volume ratio of the oil phase:surfactant:carrier:internal aqueous phase solution is (30-40):(1-5):(1-5):(30-40);

[0018] The surfactant is sucrose ester and / or caprylic / capric triglyceride; the carrier is pentanedione; the oil phase is selected from one or more of triacetin, corn oil, peanut oil, almond oil, coconut oil, and olive oil; the internal aqueous phase solution has a pH of 8-9 and is specifically selected from one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium carbonate, potassium bicarbonate, and potassium hydroxide solutions.

[0019] Preferably, the microfiltration membrane module used in step (6) has a molecular weight cutoff of 200-300 nm and is used for microfiltration at room temperature under conditions of 0.08-0.12 MPa.

[0020] The second aspect of the present invention provides the use of a tobacco flavoring rich in flavonoids and chlorogenic acid, which involves diluting the tobacco flavoring rich in flavonoids and chlorogenic acid by half with ethanol at a mass ratio of 75-100% and then adding it to cigarette tobacco.

[0021] Preferably, the mass ratio of the diluted tobacco flavoring rich in flavonoids and chlorogenic acid to the cigarette tobacco is 1:1000-10:1000.

[0022] The above technical solutions can be freely combined, provided they do not contradict each other.

[0023] The present invention has the following beneficial effects:

[0024] 1. Traditional processes for extracting flavonoids and chlorogenic acid from tobacco raw materials often employ methods such as column chromatography, preparative chromatography, ultrasonic extraction, organic solvent extraction, supercritical fluid extraction, and macroporous resin adsorption. These methods suffer from complex processes, high processing difficulty, low extraction rates, poor selectivity, and high energy consumption, limiting their industrial application. The present invention provides a method for preparing tobacco flavorings rich in flavonoids and chlorogenic acid. For the first time, it utilizes emulsion membrane technology. At room temperature, an inner aqueous phase, an outer aqueous phase, an oil phase, a surfactant, and a carrier are combined to form an emulsion membrane system. The resulting water-in-oil-in-water emulsion contains numerous emulsion droplets with a diameter of 0.05-0.20 cm, enabling selective separation of effective components from waste tobacco raw materials such as waste tobacco leaves, tobacco dust, tobacco fragments, and tobacco stems, yielding tobacco flavorings rich in flavonoids and chlorogenic acid. The separation and enrichment of the inner aqueous phase, membrane phase, and outer aqueous phase of an emulsion membrane combines extraction and back-extraction into one process. The extraction of the oil phase from the outer aqueous phase and the back-extraction of the inner aqueous phase from the oil phase occur simultaneously. Therefore, it offers unparalleled advantages over conventional extraction methods when separating and enriching flavonoids and chlorogenic acid at relatively low concentrations. The entire process approaches complete extraction, achieving high yield, fast rate, and high selectivity, overcoming the problems associated with traditional enrichment processes. The oil phase can be recycled for reuse in the next emulsion preparation, requiring less reagent and resulting in lower product costs. Furthermore, separation is performed at room temperature with a short time, avoiding the problem of flavonoids and chlorogenic acid being easily oxidized by heat, leading to loss of their biological activity. This method achieves environmental safety, refined processing, room-temperature separation, reduced energy consumption and costs, and easy industrialization of equipment, making it a green and environmentally friendly approach with high economic benefits.

[0025] 2. The reagents used in the emulsion system selected in this invention—oil phase, surfactant, carrier, and internal aqueous phase solution—not only exhibit high selectivity and high extraction yield for flavonoids and chlorogenic acid, but are also all additives listed in the "YQ 52—2015 List of Additives Permitted for Use in Tobacco Products," thus contributing to the aroma of cigarettes. Therefore, using the emulsion system of this invention not only enriches the flavonoid and chlorogenic acid components in tobacco but also helps improve the smoking quality of cigarettes.

[0026] 3. Currently, commonly used emulsion membrane systems are mainly used for chemical wastewater treatment, amino acid separation, and antibiotic separation. They are not very selective for flavonoids and chlorogenic acid, and the reagents used are kerosene, sulfurized kerosene, Span 80, Tween 80, and liquid paraffin. Adding them to cigarettes will cause obvious oral, nasal, and throat irritation, obvious off-flavors, and residual aftertaste. There are also safety risks, making it difficult to apply them to cigarettes.

[0027] 4. The tobacco flavorings obtained by this invention through a unique extraction method are rich in flavonoids and chlorogenic acid. When added to cigarettes, they significantly increase the sweet aroma, improve the fineness and smoothness of the smoke, enhance the aroma quality and quantity, improve permeability, significantly improve the aftertaste and off-flavors, mellow the taste, reduce the irritation of smoking, and improve the smoking quality. These effects are beyond the expectations of those skilled in the art. Detailed Implementation

[0028] The invention will be further described below with reference to the embodiments.

[0029] Example 1

[0030] A method for preparing a tobacco flavoring rich in flavonoids and chlorogenic acid includes the following steps:

[0031] (1) Take 1 kg of a mixture of tobacco dust and tobacco stems and add 8 kg of 65% ethanol. Perform two hot reflux extractions at 70℃. The first extraction time is 3 h and the second extraction time is 2 h. After combining the two extracts, filter them with 400 mesh gauze to obtain tobacco extract.

[0032] (2) The tobacco extract obtained in step (1) is concentrated under vacuum at 60°C until the density reaches 1.1 g / cm³. 3 Tobacco concentrate was obtained;

[0033] (3) Add an appropriate amount of hydrochloric acid aqueous solution to the tobacco concentrate obtained in step (2), adjust the pH value to 5, filter with filter cloth, and obtain an external aqueous phase solution.

[0034] (4) Triacetin, sucrose ester and pentanedione were mixed and added to a sodium carbonate solution with a pH of 9. The mixture was then placed in an emulsification container with a volume ratio of 30:1:1:30. The mixture was stirred at 10000 r / min for 30 min to obtain a stable W / O / W type emulsion.

[0035] (5) Mix the filtrate obtained in step (3) with the W / O / W emulsion obtained in step (4) evenly, stir at 300 r / min for 30 min, let stand for 30 min, and then separate the emulsion phase and the aqueous phase.

[0036] (6) The emulsion obtained in step (5) is separated at room temperature and under 0.08 MPa by a microfiltration membrane with a molecular weight cutoff of 200 nm. After the filtrate is allowed to stand and separate into layers, the oil phase is recovered and used to prepare the emulsion again. The aqueous phase filtrate is collected for later use.

[0037] (7) Add hydrochloric acid to the aqueous filtrate obtained in step (6) to adjust the pH to 7, add 10% propylene glycol by mass, and concentrate under vacuum at 60°C until the density reaches 1.15 g / cm³. 3 This yields tobacco flavorings rich in flavonoids and chlorogenic acid.

[0038] Example 2

[0039] A method for preparing a tobacco flavoring rich in flavonoids and chlorogenic acid includes the following steps:

[0040] (1) Take 1 kg of waste tobacco leaves and add 10 kg of 80% ethanol. Perform two hot reflux extractions at 80℃. The first extraction time is 4 h and the second extraction time is 1 h. After combining the two extracts, filter with 400 mesh gauze to obtain tobacco extract.

[0041] (2) The tobacco extract obtained in step (1) is concentrated under vacuum at 60°C until the density reaches 1.2 g / cm³. 3 Tobacco concentrate was obtained;

[0042] (3) Add an appropriate amount of lactic acid aqueous solution to the tobacco concentrate obtained in step (2), adjust the pH value to 4.5, filter with filter cloth, and obtain an external aqueous phase solution.

[0043] (4) Mix peanut oil, caprylic acid glyceride and pentylene glycol, add sodium hydroxide solution with pH 8 and place in an emulsification container. The volume ratio of peanut oil, caprylic acid glyceride and pentylene glycol to sodium hydroxide solution is 8:1:1:8. Stir at high speed for 40 min at 10000 r / min to obtain a stable W / O / W type emulsion.

[0044] (5) Mix the filtrate obtained in step (3) with the W / O / W emulsion obtained in step (4) evenly, stir at 300 r / min for 20 min, let stand for 40 min, and then separate the emulsion phase and the aqueous phase.

[0045] (6) The emulsion obtained in step (5) is separated at room temperature and under 0.08 MPa by a microfiltration membrane with a molecular weight cutoff of 200 nm. After the filtrate is allowed to stand and separate into layers, the oil phase is recovered and used to prepare the emulsion again. The aqueous phase filtrate is collected for later use.

[0046] (7) Add lactic acid to the aqueous filtrate obtained in step (6) to adjust the pH to 7, add 10% propylene glycol by mass, and concentrate under vacuum at 60°C until the density reaches 1.1 g / cm³. 3 This yields tobacco flavorings rich in flavonoids and chlorogenic acid.

[0047] Comparative Example 1

[0048] A method for extracting tobacco flavorings involves adding 9 times the volume of 85% methanol to tobacco fragments and performing two hot reflux extractions at 60°C. The extract is then evaporated and concentrated to 1.2 g / cm³ at 65°C and 80 kPa. 3 Tobacco flavorings and fragrances are obtained.

[0049] Comparative Example 2

[0050] A method for extracting tobacco flavorings involves adding 10 times the volume of 75% methanol to tobacco fragments, performing two ultrasonic extractions at 45°C, and then evaporating and concentrating the extract to 1.2 g / cm³ at 50°C and 80 kPa. 3 Tobacco flavorings and fragrances are obtained.

[0051] Comparative Example 3

[0052] A method for extracting tobacco flavoring, compared with Example 1, wherein step 4 is modified as follows: kerosene, Span 80 and liquid paraffin are mixed, and an aqueous sodium hydroxide solution with pH 9 is added as the inner aqueous phase solution and placed in an emulsification container. The volume ratio of oil phase:surfactant:carrier:inner aqueous phase solution is 95:3:2:95. Tobacco flavoring is then obtained.

[0053] Example 3

[0054] To compare the effects of different processes on the accumulation of flavonoids and chlorogenic acid, the tobacco flavorings prepared in Examples 1, 2, Comparative Example 1, and Comparative Example 2 of this invention were statistically analyzed according to the standard "Determination of Polyphenolic Compounds, Chlorogenic Acid, Hyoscyamine and Rutin in Tobacco and Tobacco Products (YC / T 202—2006)". The results are shown in Table 1.

[0055] Table 1 Statistical results of component content in different samples

[0056]

[0057] The results showed that the tobacco flavorings prepared using the methods of this invention (Examples 1 and 2) had the highest contents of chlorogenic acid and flavonoids (mainly rutin) compared to those prepared by organic solvent extraction (Comparative Example 1) and ultrasonic extraction (Comparative Example 2). The contents were also slightly higher than those prepared by the existing emulsion membrane method (Comparative Example 3). This indicates that the method of this invention can effectively enrich the chlorogenic acid and flavonoid components in tobacco with a high yield, achieving full utilization of tobacco raw materials.

[0058] Example 4

[0059] Sensory evaluation of cigarettes: The tobacco flavorings obtained in Examples 1, 2, 1, 2, and 3 of this invention were diluted with 75% alcohol by half and injected into cigarettes at a rate of 1% per cigarette using an injection molding machine, resulting in cigarettes of Example 1 (50 cigarettes), Example 2 (50 cigarettes), Comparative Example 1 (50 cigarettes), Comparative Example 2 (50 cigarettes), and Comparative Example 3 (50 cigarettes). 50 blank cigarettes without added flavorings were used as a control. All the cigarettes were placed in a constant temperature and humidity chamber (temperature 22±1℃, humidity 60±2%) for 48 hours to equilibrate. The cigarettes were then evaluated by qualified experts according to GB5606.4-2005 "Sensory Technical Requirements for Cigarettes Part 4" and YC / T 497-2014 "Sensory Evaluation Method for Chinese Style Cigarettes". The evaluation results are shown in Tables 2, 3, and 4.

[0060] Table 2. Results of Cigarette Smoking Evaluation

[0061]

[0062] Table 3 Evaluation Results of Cigarette Comfort Characteristics

[0063]

[0064] Table 4 Evaluation Results of Cigarette Smoke Characteristics

[0065]

[0066]

[0067] The results show that the tobacco flavoring obtained by the present invention has the effects of significantly increasing the sweet aroma, improving the fineness and smoothness of the smoke, enhancing the aroma quality and aroma quantity, enhancing permeability, significantly improving the aftertaste and off-flavors, mellowing the taste, reducing the irritation of smoking, and improving the smoking quality.

[0068] As shown in Tables 2, 3, and 4, cigarettes with the tobacco flavoring and fragrance obtained in this invention exhibit a prominent sweet aroma when smoked, significantly improving permeability and demonstrating a clear effect on enhancing aroma quality and quantity. This effect stems from the volatile substances produced during the thermal decomposition of chlorogenic acid and flavonoids, which enhance aroma quality and quantity. Furthermore, the cigarette has a pleasant aftertaste, significantly reduced off-flavors, and greatly improved irritation. This is because during combustion, chlorogenic acid and flavonoids undergo an acidic reaction, neutralizing some of the alkalinity, thus resulting in a mellow taste, reduced irritation, and increased smoke harmony. In contrast, the tobacco flavoring and fragrance in Comparative Examples 1-3 did not show significant effects.

[0069] This is because Comparative Examples 1 and 2 use methanol, an organic solvent that is highly volatile, flammable, and explosive, making processing difficult, unsafe, and highly polluting. Furthermore, methanol has a distinctive odor that can introduce irritation and off-flavors into the extracted tobacco flavorings. Comparative Example 3 uses the existing emulsion membrane method, which can separate chlorogenic acid and flavonoids from tobacco, but the solvents used are kerosene, Span 80, and liquid paraffin. These solvents are toxic and irritating, making them unsuitable for addition to cigarettes and causing significant oral, nasal, and throat irritation, as well as lingering aftertaste on the tongue.

[0070] Therefore, the preparation method proposed in this invention can not only enrich chlorogenic acid and flavonoids in tobacco raw materials, but also increase the added value of tobacco waste raw materials.

[0071] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing tobacco flavoring rich in flavonoids and chlorogenic acid, characterized in that, Includes the following steps: (1) Add an ethanol solution with a mass percentage concentration of 20-95% to the tobacco raw material, perform hot reflux extraction at 50-80℃, and filter to obtain tobacco extract; (2) The tobacco extract obtained in step (1) is concentrated under vacuum at 60-70℃ to a density of 1.2-1.3 g / cm³. 3 Tobacco concentrate was obtained; (3) Add an appropriate amount of acid to the tobacco concentrate obtained in step (2) to adjust the pH value to 4-5, filter, and the resulting filtrate is the external aqueous phase solution; (4) Mix the surfactant, carrier and oil phase, add the internal aqueous phase solution and place it in an emulsification container and stir at a speed of 3000-10000 r / min to obtain a stable W / O / W type emulsion; (5) Mix the external aqueous solution from step (3) with the W / O / W emulsion obtained from step (4) until homogeneous, stir at 100-400 r / min for 10-40 min, let stand and separate the emulsion phase and aqueous phase; (6) The emulsion obtained in step (5) is microfiltered at room temperature under a pressure of 0.08-0.12 MPa through a microfiltration membrane module. After the filtrate is allowed to stand and separate into layers, the oil phase is recovered for reuse, and the aqueous phase filtrate is collected for later use. (7) Add acid to the aqueous filtrate obtained in step (6) to adjust the pH to 7-7.5, add 10% propylene glycol by mass, and concentrate under vacuum at 60-70℃ to a density of 1.0-1.3 g / cm³. 3 This yields tobacco flavorings rich in flavonoids and chlorogenic acid; The volume ratio of the oil phase:surfactant:carrier:internal aqueous phase solution is (30-40):(1-5):(1-5):(30-40). The surfactant is sucrose ester and / or caprylic / capric triglyceride; the carrier is pentanedione; the oil phase is selected from one or more of triacetin, corn oil, peanut oil, almond oil, coconut oil, and olive oil; the internal aqueous phase solution has a pH of 8-9 and is selected from one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium carbonate, potassium bicarbonate, and potassium hydroxide solutions. The microfiltration membrane module has a molecular weight cutoff of 200-300 nm.

2. The preparation method according to claim 1, characterized in that, The tobacco raw material is selected from one or more of waste tobacco leaves, tobacco dust, tobacco leaf fragments, and tobacco stems; the mass ratio of the tobacco raw material to ethanol is 1:5-1:

25.

3. The preparation method according to claim 1, characterized in that, The acid solution mentioned in steps (3) and (7) is selected from one or more of hydrochloric acid, lactic acid, malic acid, citric acid and benzoic acid.

4. The use of a tobacco flavoring rich in flavonoids and chlorogenic acid prepared by the method for preparing tobacco flavoring rich in flavonoids and chlorogenic acid as described in claim 1, characterized in that, The tobacco flavorings rich in flavonoids and chlorogenic acid are diluted with ethanol at a ratio of 75-100% by mass and then added to cigarette tobacco for application.

5. The use as described in claim 4, characterized in that, The mass ratio of the diluted tobacco flavoring rich in flavonoids and chlorogenic acid to the cigarette tobacco is 1:1000-10:1000.

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