A pretreatment method for the molecular distillation process of tobacco extract

Abstract

This invention discloses a pretreatment method for the molecular distillation process of tobacco extract. The pretreatment method includes: diluting the tobacco extract to be treated with deionized water at a mass ratio of 1:(2~5) and maintaining the temperature; adding cellulase, pectinase, and protease to the solution for complex enzymatic hydrolysis to directionally degrade pectin, cellulose, and protein macromolecules in the extract; adding 1~5 times the volume of 95% ethanol according to the characteristics of different tobacco extract varieties for enzyme inactivation and alcohol precipitation, followed by freezing; filtering to remove precipitated impurities and then concentrating under reduced pressure to obtain the pretreated product. This invention, through the synergistic effect of complex enzymatic hydrolysis and differentiated alcohol precipitation, thoroughly removes macromolecular impurity precursors that cause scorching during molecular distillation, enabling the pretreated extract to maintain excellent fluidity and thermal stability during molecular distillation, completely avoiding scorching and wall adhesion, and significantly improving process stability and equipment adaptability.

Description

Technical Field

[0001] This invention relates to the field of tobacco flavoring raw material processing technology, specifically to a treatment method for tobacco extract before the molecular distillation process. Background Technology

[0002] Tobacco flavoring ingredients are essential raw materials in cigarette flavoring. Adding them to tobacco flavoring liquids can effectively enrich cigarette smoke, enhance the characteristic aroma of tobacco, and improve the smoking quality of cigarettes. Currently, tobacco manufacturers mostly purchase tobacco flavoring ingredients for direct use, and there is a lack of technical research on obtaining tobacco flavoring ingredients from tobacco extracts.

[0003] Commercially available tobacco extracts produce irritating substances such as methanol, formaldehyde, and lower aldehydes during cigarette combustion, resulting in significant oral residue, strong irritation, and a decline in aroma and comfort. To address these issues, manufacturers typically perform molecular distillation to refine the extracts, further developing tobacco flavoring ingredients and avoiding the drawbacks of direct use.

[0004] However, the inventors' preliminary research revealed that commercially available tobacco extracts of different varieties and sources all exhibited a phenomenon of raw material condensation and coking in the main evaporator of the molecular distillation apparatus during molecular distillation, hindering the smooth progress of subsequent molecular distillation processes. In view of this, this invention addresses this issue and provides a customized, efficient treatment method to resolve this phenomenon. Summary of the Invention

[0005] The inventors discovered in their preliminary research that commercially available tobacco extracts of different varieties and sources exhibit varying degrees of condensation and coking in the main evaporator of the molecular distillation apparatus during molecular distillation, hindering subsequent molecular distillation processes. To address this problem of condensation and coking of commercially available extracts in the molecular distillation apparatus, this invention proposes a pretreatment method for the molecular distillation process of tobacco extracts.

[0006] The specific technical solution of this invention is as follows:

[0007] This invention provides a pretreatment method for the molecular distillation process of tobacco extract, comprising the following steps:

[0008] Step S1: Mix the tobacco extract to be molecularly distilled with deionized water, heat and keep warm;

[0009] Step S2: Add cellulase, pectinase and protease to the liquid obtained in step S1, mix well, and stir for a period of time.

[0010] Step S3: Add different amounts of ethanol to the liquid obtained in step S2 according to different varieties of tobacco extract, stir evenly, and freeze the liquid.

[0011] Step S4: Filtration. Take the filtrate and concentrate it under reduced pressure. Pretreatment is complete.

[0012] For different varieties of tobacco extracts from Yunnan, Henan, and Zimbabwean tobacco, the molecular distillation process following the pretreatment method described above effectively avoids scorching and stagnation during molecular distillation, preventing residue buildup on the evaporator walls and significantly improving the stability and equipment adaptability of the molecular distillation process for tobacco extracts. Furthermore, this customized pretreatment process, while removing impurities and resolving scorching issues, effectively preserves and enhances the inherent aroma characteristics of various tobacco raw materials, such as the sweet aroma of Yunnan tobacco, the rich aroma of Henan tobacco, and the mellow sweet aroma of Zimbabwean tobacco, achieving a synergistic improvement in the sensory quality of the tobacco extracts.

[0013] Preferably, in step S1, the tobacco extract to be molecularly distilled includes the following different varieties of tobacco extract:

[0014] Commercially available crude extracts of Yunnan tobacco, crude extracts of Henan tobacco, and imported Zimbabwean tobacco extract.

[0015] Preferably, in step S1, the mass ratio of tobacco extract to deionized water is 1:(2~5).

[0016] Further preferred, in step S1, the specific operation of heating and holding the temperature is as follows: heating to 45℃~55℃ and maintaining the temperature within this range for 5~20 minutes.

[0017] Preferably, in step S2, the amount of cellulase, pectinase and protease added to each 100kg of the liquid obtained in step S1 is 100~500g.

[0018] Preferably, in step S2, the stirring temperature is 40~55℃ and the time is 4~6 hours.

[0019] Preferably, in step S2, the amount of ethanol added to the liquid obtained in step S2 varies depending on the type of tobacco extract, including:

[0020] For crude extraction of tobacco extract, the amount of ethanol added is 3 to 4 times the volume of the liquid obtained in step S2;

[0021] For crude extraction of tobacco extract, the amount of ethanol added is 1 to 3 times the volume of the liquid obtained in step S2;

[0022] For imported Zimbabwean tobacco extract, the amount of ethanol added is 2 to 5 times the volume of the liquid obtained in step S2.

[0023] Preferably, in step S3, the freezing temperature is -25℃ to -10℃, and the freezing time is 8 to 24 hours.

[0024] Preferably, in step S4, the conditions for vacuum concentration include: a vacuum degree of -0.08MPa to -0.095MPa, a feed liquid temperature of below 60℃, and a specific gravity of the concentrated feed liquid of 1.13 to 1.17.

[0025] Based on the above, this invention provides an application of a pretreatment method in the molecular distillation process of tobacco extract. By performing the pretreatment method described above before the molecular distillation of the tobacco extract, the phenomena of liquid condensation and coking in the main evaporator of the molecular distillation apparatus can be avoided during the process.

[0026] Compared with the prior art, the present invention has the following technical effects:

[0027] 1. This invention eliminates the slagging and condensation phenomena in the molecular distillation process of commercially available tobacco extracts, preventing them from sticking to the evaporator walls and slagging, and significantly improving the stability of the molecular distillation process and the adaptability of the equipment for tobacco extracts.

[0028] 2. This invention utilizes a customized processing technology for extracts from different varieties of tobacco, including Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco. This process removes impurities and solves the problem of charring while effectively preserving and highlighting the inherent aroma characteristics of various tobacco raw materials, such as the sweet aroma of Yunnan tobacco, the rich aroma of Henan tobacco, and the mellow sweet aroma of Zimbabwean tobacco. This achieves a synergistic improvement in the sensory quality of tobacco extracts.

[0029] 3. This invention expands the development prospects of high-end tobacco flavoring raw materials based on customized processing technology for extracts of different varieties of tobacco such as Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco, while taking into account both purification effect and industrial feasibility. Attached Figure Description

[0030] Figure 1 This invention provides an exemplary pretreatment method for the molecular distillation process of tobacco extract.

[0031] Figure 2 This is an illustration of a molecular distillation apparatus after the tobacco extract processed by the present invention has undergone molecular distillation, as an example of an embodiment of the present invention.

[0032] Figure 3 The illustration shows the coking phenomenon in a molecular distillation apparatus used for molecular distillation of tobacco extract that has not been treated by the present invention, as an example of an embodiment of the present invention. Detailed Implementation

[0033] The present invention will be further described below with reference to embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0034] The inventors' preliminary research revealed that commercially available tobacco extracts from different varieties and sources, especially extracts from Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco, exhibit varying degrees of raw material stagnation and coking in the main evaporator of the molecular distillation apparatus during molecular distillation, hindering subsequent molecular distillation processes. Therefore, to address this issue, this embodiment provides a pretreatment method for the molecular distillation process of tobacco extracts.

[0035] Combination Figure 1 As shown in this embodiment, a pretreatment method for the molecular distillation process of tobacco extract is provided, which includes the following steps:

[0036] Step S1: Mix the tobacco extract to be molecularly distilled with deionized water, heat and keep warm;

[0037] Step S2: Add cellulase, pectinase and protease to the liquid obtained in step S1, mix well, and stir for a period of time.

[0038] Step S3: Add different amounts of ethanol to the liquid obtained in step S2 according to different varieties of tobacco extract, stir evenly, and freeze the liquid.

[0039] Step S4: Filtration. Take the filtrate and concentrate it under reduced pressure. Pretreatment is complete.

[0040] For different types of extracts, the molecular distillation process following the pretreatment method described above effectively avoids scorching and stagnation during molecular distillation, preventing residue buildup and scorching on the evaporator walls. This significantly improves the stability and equipment adaptability of the molecular distillation process for tobacco extracts. Furthermore, this customized pretreatment process, while removing impurities and addressing scorching, effectively preserves and enhances the inherent aroma characteristics of various tobacco raw materials, such as the sweet aroma of Yunnan tobacco, the rich aroma of Henan tobacco, and the mellow sweet aroma of Zimbabwean tobacco, achieving a synergistic improvement in the sensory quality of tobacco extracts. The various steps described above are inextricably linked and work synergistically to address the scorching problem and improve the quality of the distilled product.

[0041] First, step S1 involves mixing the tobacco extract to be treated with deionized water at a ratio of 1:(2~5) to reduce the initial viscosity of the extract, thereby facilitating subsequent enzymatic hydrolysis. During the enzymatic hydrolysis stage, the macromolecular substances in the extract are degraded through the synergistic action of three complex enzymes, and the addition of deionized water facilitates this process. A key aspect of the pretreatment method demonstrated in this embodiment is the differentiated adjustment of alcohol precipitation parameters based on the raw materials. Different amounts of ethanol are added depending on the type of tobacco extract. This step effectively and completely removes soluble coking precursors, thus effectively preventing coking and stagnation during molecular distillation. After adding ethanol and freezing, the mixture is filtered, and the filtrate is concentrated under reduced pressure to obtain the pretreated product for molecular distillation. Concentrating the filtrate before molecular distillation increases the distillation rate and improves process feasibility.

[0042] In one embodiment, in step S2, different amounts of ethanol are added to the liquid obtained in step S2 according to different varieties of tobacco extract, including:

[0043] For crude extraction of tobacco extract, the amount of ethanol added is 3 to 4 times the volume of the liquid obtained in step S2;

[0044] For crude extraction of tobacco extract, the amount of ethanol added is 1 to 3 times the volume of the liquid obtained in step S2;

[0045] For imported Zimbabwean tobacco extract, the amount of ethanol added is 2 to 5 times the volume of the liquid obtained in step S2.

[0046] In this embodiment of the invention, the ethanol used is food-grade 95% ethanol, where 95% is a volume percentage concentration; the deionized water used is industrial-grade deionized water.

[0047] In one embodiment, the different types of tobacco extracts include Yunnan tobacco extract, Henan tobacco extract, and imported Zimbabwean tobacco extract. That is, in step S1, the tobacco extracts to be molecularly distilled include the following different types of tobacco extracts: commercially available crude Yunnan tobacco extract, crude Henan tobacco extract, and imported Zimbabwean tobacco extract.

[0048] In some embodiments of the present invention, crude extracts of Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco from different manufacturers were tested. All of these extracts exhibited varying degrees of scorching during molecular distillation, which may be related to the raw material characteristics of different tobacco varieties. In one specific embodiment, the crude extracts of Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco were purchased from Shanghai Daofan Biotechnology Co., Ltd., with product models DF6030, DF6031, and DF68094, respectively. After undergoing the aforementioned pretreatment methods, molecular distillation was performed on these crude extracts of Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco, and no scorching occurred. Figure 2 As shown. Tobacco extracts that do not conform to the method of this invention exhibit coking in the molecular distillation apparatus after molecular distillation, such as... Figure 3 As shown.

[0049] Furthermore, different varieties of extracts can be mixed or not mixed, and then used as tobacco extracts for molecular distillation to undergo the above-mentioned pretreatment. In one embodiment, crude Yunnan tobacco extract DF6030 and crude Henan tobacco extract DF6031 are mixed and used as tobacco extracts for molecular distillation to undergo the above-mentioned pretreatment. The aroma of the pretreated product and the distilled product are effectively improved. This is because the obvious roasted and sweet aroma of Henan tobacco and the fresh herbal sweet aroma of Yunnan tobacco are well-matched. Moreover, after being treated by the pretreatment method of the present invention, the inherent characteristic aromas of the two tobacco raw materials can be highlighted, forming a synergistic quality improvement effect where Yunnan tobacco provides a sweet and characteristic aroma base and Henan tobacco enhances the concentration and thickness. The preferred mass ratio of the two raw materials is 1.2:1.

[0050] Optimizing the amount of deionized water added can effectively improve the quality of pretreated and distilled products, especially in preventing scorching. Appropriate dilution can significantly reduce the initial viscosity of the extract system, improve the mass transfer environment, and allow cellulase, pectinase, and protease to fully diffuse in the feed solution and contact the substrate, thus ensuring the uniformity and thoroughness of the degradation reaction of macromolecular impurities. If the dilution factor is insufficient, the system viscosity will be too high, resulting not only in low enzymatic hydrolysis efficiency but also in excessively high viscosity of the concentrated product. Under the high temperature and high vacuum conditions of molecular distillation, this can easily lead to flow hindrance and localized overheating, thereby inducing scorching. Furthermore, for the above-mentioned extract raw materials, the dilution factor should be controlled within 5 times to avoid excessive dilution and loss of aroma components, balancing impurity removal efficiency and sensory quality preservation. If the amount of deionized water added is less than twice that of the tobacco extract, scorching is significant. In some embodiments, in step S1, the mass ratio of tobacco extract to deionized water is 1:(2~5).

[0051] In some embodiments, the preferred specific operation of heating and holding the temperature in step S1 is to heat the sample to 45°C~55°C and maintain the temperature within this range for 5~20 minutes. Preheating the extract solution to this temperature can make the internal temperature and viscosity distribution of the solution uniform, which is beneficial to improving the effect of preventing molecular distillation coking.

[0052] In some embodiments, in step S2, the amount of cellulase, pectinase, and protease added to each 100 kg of the liquid obtained in step S1 is 100-500 g. Within this range, the targeted and complete degradation of the three macromolecules—pectin, cellulose, and protein—can be achieved. In this embodiment of the invention, the three enzymes are all commercially available enzymes, wherein: cellulase (enzyme activity ≥ 100,000 U / g), pectinase (enzyme activity 55,000 U / g), and protease are neutral proteases (enzyme activity ≥ 200,000 U / g). Specifically, the cellulase and neutral protease were purchased from Xiasheng Biotechnology Co., Ltd., with cellulase model Cellulase C100 and neutral protease model NeuPro 200; the pectinase was purchased from Amano Enzyme Products Co., Ltd., with production batch number CPV0352201LK and CAS number 9032-75-1.

[0053] In some preferred embodiments, the amount of enzyme preparation added is adjusted according to the different varieties of extract raw materials. Specifically, in every 100 kg of the liquid obtained in step S1, the crude extract of Yunnan tobacco contains 100-300 g of cellulase, 100-300 g of pectinase, and 200-500 g of protease; the crude extract of Henan tobacco contains 200-500 g of cellulase, 100-400 g of pectinase, and 100-400 g of protease; and the Zimbabwean tobacco extract contains 100-400 g of cellulase, 100-400 g of pectinase, and 100-400 g of protease.

[0054] In one embodiment, experiments showed that the temperature range of 45℃ to 55℃ is the optimal catalytic temperature range for the synergistic effect of the three enzymes. This ensures that the enzyme molecules are in a highly active conformation, avoiding incomplete enzymatic hydrolysis and impurity residue due to excessively low temperatures, or thermal denaturation and inactivation of the enzyme protein due to excessively high temperatures. Therefore, in some embodiments, the stirring temperature in step S2 is 40℃ to 55℃, and the time is 4 to 6 hours. Under the synergistic effect of this temperature and time, the enzymatic hydrolysis reaction can achieve a high impurity degradation rate, while avoiding aroma loss due to excessive stirring. In the method of this invention, 4 hours of enzymatic hydrolysis is sufficient for impurity removal. Extending the hydrolysis time can improve the hydrolysis effect. However, a comparative experiment showed that as the hydrolysis time is extended, energy consumption and aroma component loss increase. Selecting a hydrolysis window of 4 to 6 hours ensures that no charring occurs during molecular distillation while maximizing the preservation of the tobacco's natural aroma.

[0055] In some embodiments, in step S3, the freezing temperature is -25°C to -10°C, and the freezing time is 8 to 24 hours. This freezing condition promotes the full crystallization and aggregation of polysaccharides, peptides, and denatured proteins precipitated from alcohol, forming larger particles, thereby significantly improving impurity separation efficiency. If the temperature is above -10°C, impurity crystallization is incomplete, the purification effect decreases, and residual soluble impurities will become coke nuclei during molecular distillation. If the temperature is below -25°C, the feed solution will excessively solidify, significantly increasing filtration difficulty and unnecessarily increasing production energy consumption. A freezing time of 8 to 24 hours ensures that the center temperature of the feed solution uniformly reaches the set value, optimizing impurity precipitation and separation, improving impurity separation efficiency, and helping to remove the causes of coking.

[0056] Concentrating the filtrate before molecular distillation improves the distillation rate and enhances process feasibility. In some embodiments, the vacuum concentration conditions in step S4 include: a vacuum degree of -0.08 MPa to -0.095 MPa, a feed temperature below 60°C, and a specific gravity of 1.13 to 1.17 for the concentrated feed. Specific gravity is the ratio of the mass of the same volume of tobacco extract to the mass of the same volume of pure water at 25°C.

[0057] In one embodiment, after the pretreatment described in the above embodiment, the obtained pretreated product is purified by molecular distillation to collect the light components and obtain the purified product. The molecular distillation process is performed using a molecular distillation apparatus, specifically a scraped-film distillation. Exemplarily, during molecular distillation, the sample injection rate of the molecular distillation apparatus is 20-30 mL / min, the temperature of the main evaporator of the molecular distillation apparatus is set to 120-150°C, and the vacuum degree is -0.002 mbar to -0.005 mbar. After distillation, the light components are collected and condensed at a temperature of -10 to 10°C.

[0058] The present invention will be illustrated below with reference to more specific embodiments to demonstrate the invention more clearly. In the following embodiments, the crude extracts of Yunnan tobacco, Henan tobacco, and Zimbabwean tobacco extract were purchased from Shanghai Daofan Biotechnology Co., Ltd., with product models DF6030, DF6031, and DF68094, respectively.

[0059] Example 1: Pretreatment of crude tobacco extract

[0060] A pretreatment method for crude tobacco extract before molecular distillation, comprising the following steps:

[0061] S1. Take 750g of crude tobacco extract, add 250g of deionized water, stir evenly to dilute, heat to 50℃ and keep at that temperature for 10 minutes.

[0062] S2. Add 3g of cellulase, 3g of pectinase and 3g of protease to the liquid obtained in step S1 (1000g), and stir for 5 hours at a constant temperature of 50℃.

[0063] S3. Add 95% ethanol to the enzymatic hydrolysis product. The mass of 95% ethanol added should be 4 times the total mass of the material. Stir for 10 minutes until homogeneous.

[0064] S4. Place the liquid obtained in S3 in a -18℃ cold storage. Start timing when the temperature at the center point of the liquid reaches -18℃. The freezing time is 12 hours. After freezing, use vacuum filtration to collect the filtrate.

[0065] S5. Place the filtrate in a vacuum concentration tank, adjust the vacuum degree to -0.09MPa, control the material temperature to 50℃, and concentrate under reduced pressure until the product specific gravity is 1.152 to obtain the pretreated product.

[0066] Evaluation of the pretreated product: The aroma quality is significantly improved, the characteristic aroma is more pronounced, the aroma is full, there is no residue in the mouth, the irritation of the smoke is greatly reduced, the comfort is good, and the sweet aroma of Yunnan tobacco extract is preserved.

[0067] Example 2: Pretreatment of crude tobacco extract

[0068] A pretreatment method for crude tobacco extract before molecular distillation, comprising the following steps:

[0069] S1. Take 750g of crude tobacco extract, add 250g of deionized water, stir evenly to dilute, heat to 51℃ and keep at that temperature for 10min.

[0070] S2. Add 2g of cellulase, 2g of pectinase and 2g of protease to the liquid obtained in step S1 (1000g), and stir at a constant temperature of 51℃ for 5 hours for enzymatic hydrolysis.

[0071] S3. Add 95% ethanol to the enzymatic hydrolysis product. The mass of 95% ethanol added should be twice the total mass of the material. Stir for 10 minutes until homogeneous.

[0072] S4. Place the liquid obtained in S3 in a -18℃ cold storage. Start timing when the temperature at the center point of the liquid reaches -18℃. The freezing time is 12 hours. After freezing, use vacuum filtration to collect the filtrate.

[0073] S5. Place the filtrate in a vacuum concentration tank, adjust the vacuum degree to -0.085MPa, control the material temperature to 52℃, and concentrate under reduced pressure until the product specific gravity is 1.150 to obtain the pretreated product.

[0074] Evaluation of the pretreated product: The aroma quality is improved, the characteristic aroma is significantly enhanced, the aroma is full and well-formed, there is no residue in the mouth, the irritation of the smoke is reduced, the comfort is good, and the strong aroma characteristics of Henan tobacco extract are preserved.

[0075] Example 3: Pretreatment of imported Zimbabwean tobacco extract

[0076] A pretreatment method for imported Zimbabwean tobacco extract before molecular distillation, comprising the following steps:

[0077] S1. Take 750g of imported Zimbabwean tobacco extract, add 250g of deionized water, stir evenly to dilute, heat to 49℃ and keep at that temperature for 10min.

[0078] S2. Add 2g of cellulase, 2g of pectinase, and 2g of protease to the liquid obtained in step S1 (1000g). The amount of each enzyme added is 2‰ of the total amount of 1000g after dilution. Stir and hydrolyze at a constant temperature of 49℃ for 5 hours.

[0079] S3. Add 95% ethanol to the enzymatic hydrolysis product. The mass of 95% ethanol added should be 4 times the total mass of the material. Stir for 10 minutes until homogeneous.

[0080] S4. Place the liquid obtained in S3 in a -18℃ cold storage. Start timing when the temperature at the center point of the liquid reaches -18℃. The freezing time is 12 hours. After freezing, use vacuum filtration to collect the filtrate.

[0081] S5. Place the filtrate in a vacuum concentration tank, adjust the vacuum degree to -0.095MPa, control the material temperature to 48℃, and concentrate under reduced pressure until the product specific gravity is 1.151 to obtain the pretreated product.

[0082] Evaluation of the pretreated product: The aroma is enhanced, the sweet tobacco flavor is stronger, the aroma quantity and fullness are significantly improved, there is no residue in the mouth, the comfort is good, and the unique aroma of Zimbabwean tobacco extract is preserved.

[0083] Example 4: Pretreatment of crude extracts of Yunnan tobacco and Henan tobacco

[0084] A pretreatment method for crude extracts of Yunnan tobacco and Henan tobacco before molecular distillation, comprising the following steps:

[0085] S1. Take 375g of crude extracted Yunnan tobacco extract and 375g of crude extracted Henan tobacco extract, add 250g of deionized water, stir evenly to dilute, and heat to 50℃ for 10 minutes.

[0086] S2. Add 2g of cellulase, 2g of pectinase, and 2g of protease to the liquid obtained in step S1 (1000g). The amount of each enzyme added is 2‰ of the total amount of 1000g after dilution. Stir and hydrolyze at a constant temperature of 50℃ for 5 hours.

[0087] S3. Add 95% ethanol to the enzymatic hydrolysis product. The mass of 95% ethanol added should be 3 times the total mass of the product. Stir for 10 minutes until homogeneous.

[0088] S4. Place the liquid obtained in S3 in a -18℃ cold storage. Start timing when the temperature at the center point of the liquid reaches -18℃. The freezing time is 12 hours. After freezing, use vacuum filtration to collect the filtrate.

[0089] S5. Place the filtrate in a vacuum concentration tank, adjust the vacuum degree to -0.085MPa, control the material temperature to 52℃, and concentrate under reduced pressure until the product specific gravity is 1.150 to obtain the pretreated product.

[0090] Evaluation of the pretreated product: The aroma quality is significantly improved, the characteristic aroma is significantly enhanced, the aroma is sweet and refreshing, the aroma is full and cohesive, there is no residue in the mouth, the irritation of the smoke is reduced, and the comfort is good.

[0091] Example 5: Pretreatment of imported Zimbabwean tobacco extract

[0092] A pretreatment method for molecular distillation of imported Zimbabwean tobacco extract is disclosed. The specific steps differ from those in Example 3 in that, in step S3, the amount of 95% ethanol added is twice the total material mass (using an ethanol precipitation ratio suitable for Henan tobacco). Other steps are the same as in Example 3.

[0093] Evaluation of the pretreated product: The aroma is enhanced, the sweet tobacco flavor is stronger, the aroma quantity and fullness are significantly improved, there is no residue in the mouth, the comfort is good, and the unique aroma of Zimbabwean tobacco extract is preserved.

[0094] Comparative Example 1

[0095] The difference compared to Example 1 is that no pretreatment is performed.

[0096] The crude extract of tobacco used in Example 1 (Shanghai Daofan, DF6030) was directly subjected to molecular distillation for further extraction. The results showed that the liquid rapidly condensed and coked on the surface of the evaporator during the molecular distillation process, resulting in poor sample feeding and inability to operate continuously. The product had a strong burnt taste and could not be used for flavoring cigarettes.

[0097] Comparative Example 2

[0098] The difference from Example 1 is that the alcohol precipitation in step S3 is not performed. The other steps are the same as in Example 1.

[0099] The specific steps are as follows:

[0100] Steps S1 and S2 are performed in the same manner as steps S1 and S2 in Example 1. Then, the liquid obtained from enzymatic hydrolysis is placed in a -18°C cold storage. After the temperature at the center point of the liquid reaches -18°C, the freezing time is timed and is 12 hours. After freezing, the liquid is collected by vacuum filtration. Finally, the liquid is processed according to step S5 of Example 1 to obtain the pretreated product.

[0101] Comparative Example 3

[0102] Compared with Example 1, the difference is that only enzymatic hydrolysis is performed, without alcohol precipitation in step S3, and without freezing in step S4.

[0103] The specific steps are as follows:

[0104] Steps S1 and S2 are performed in the same manner as steps S1 and S2 in Example 1. Then, the liquid obtained by enzymatic hydrolysis is dehydrated and concentrated to a specific gravity of 1.152.

[0105] During molecular distillation, the following occurs: Figure 3 The coking phenomenon shown is evident. This demonstrates that without alcohol precipitation and freezing, coking impurities cannot be completely removed, and coking easily occurs during molecular distillation.

[0106] Comparative Example 4

[0107] Compared with Example 1, the difference is that in step S3, the amount of 95% ethanol added is twice the total amount (mass) of the material (using the ethanol precipitation ratio suitable for Henan tobacco). The other steps are the same as in Example 1.

[0108] Comparative Example 5

[0109] The difference from Example 1 is that no complex enzyme is added. All other steps are the same as in Example 1.

[0110] The specific steps are as follows: Step S1 is carried out in the same manner as Step S1 in Example 1, then in S2 the liquid is taken and kept at a constant temperature for 5 hours, and Steps S3, S4 and S5 are carried out in the same manner as Steps S3, S4 and S5 in Example 1 to obtain the pretreated product.

[0111] Comparative Example 6

[0112] Compared with Example 1, the difference is that in step S5, the concentration is reduced to a specific gravity of 1.20. The other steps are the same as in Example 1.

[0113] Performance evaluation and characterization

[0114] (1) The products of each example and comparative example were subjected to molecular distillation. The smoothness of the distillation process and whether coking occurred were observed. The results are shown in Table 1. Among them, the sample injection rate of the molecular distillation apparatus was 20~30mL / min, the temperature of the main evaporator of the molecular distillation apparatus was set to 120~150℃, and the vacuum degree was -0.002mbar~-0.005mbar; after distillation, the light components were collected and condensed at a temperature of -10~10℃.

[0115] Table 1

[0116] Example 1 Smooth No coagulation Example 2 Smooth No coagulation Example 3 Smooth No coagulation Example 4 Smooth No coagulation Example 5 Smooth No coagulation Comparative Example 1 Not smooth Severe Anxiety Comparative Example 2 Basically smooth Mild coagulation Comparative Example 3 Slightly smooth Slightly noticeable charring Comparative Example 4 Basically smooth Mild coagulation Comparative Example 5 Not smooth obvious scorching Comparative Example 6 Not smooth obvious scorching

[0117] As shown in Table 1, the present invention employs a synergistic approach, which involves diluting the product with water, performing enzymatic hydrolysis to degrade char-causing macromolecules, differential alcohol precipitation and freezing to remove impurities that easily cause charring, and gravity-controlled concentration. This allows the pretreated product to undergo molecular distillation, which completely avoids charring and stagnation during the molecular distillation process, resulting in a smooth distillation process.

[0118] A comparison of Example 1 and Comparative Example 1 shows that molecular distillation of commercially available crude tobacco extract DF6030 resulted in rapid stagnation and severe coking of the liquid on the evaporator surface, hindering sample feeding and preventing continuous operation. Comparisons with Comparative Examples 2-4 demonstrate that differentiated alcohol precipitation and subsequent freezing for different extract varieties effectively eliminate easily coking impurities. This indicates that enzymatic hydrolysis alone cannot completely remove coking-causing substances. While combined enzymatic hydrolysis degrades macromolecules such as pectin, cellulose, and protein, other coking-causing substances may remain in the liquid. These substances can be removed through differentiated alcohol precipitation and subsequent freezing. Comparative Example 5, without enzymatic hydrolysis, exhibited significant coking problems, highlighting the crucial role of pre-enzymatic hydrolysis in removing coking-causing substances in the pretreatment method of this invention. This further underscores the necessity of synergistic avoidance of coking during molecular distillation in each step of this invention. A comparison of Example 1 and Comparative Example 6 highlights the importance of controlling appropriate specific gravity.

[0119] (2) The distillation products collected in each example and comparative example were injected into blank Double Happiness cigarettes at an addition amount of 0.05% wt. After soaking at room temperature for 6 hours, a blind taste test was conducted by 10 professional smokers, and the average was taken. The evaluation focused on aroma, characteristic aroma, comfort, smoke irritation, and oral residue. The evaluation results are shown in Table 2. The distillation products collected in each example and comparative example were injected into blank Double Happiness cigarettes at a dosage of 0.05% wt. After soaking at room temperature for 6 hours, a blind taste test was conducted by 10 professional smokers, and the average was taken. The evaluation focused on aroma, characteristic aroma, comfort, smoke irritation, and oral residue. The evaluation results are shown in Table 2.

[0120] Table 2

[0121] Example 1 excellent powerful excellent weak none Example 2 excellent powerful excellent weak none Example 3 excellent Strong excellent weak none Example 4 excellent Strong excellent weak none Example 5 excellent Strong excellent weak none Comparative Example 1 Difference Weak (distinct burnt smell) Difference powerful have Comparative Example 2 generally generally generally Slightly stronger Slightly Comparative Example 3 generally generally generally Slightly stronger Slightly Comparative Example 4 better generally better Slightly stronger Slightly Comparative Example 5 Poor weak Poor Slightly stronger have Comparative Example 6 generally Weak generally Slightly stronger none

[0122] As shown in Table 2, the pretreatment method of this invention not only effectively prevents scorching but also retains and highlights the characteristic aromas of different tobacco varieties to the greatest extent while removing impurities. For example, the distillation products obtained after processing the extracts of Yunnan tobacco in Example 1 and Henan tobacco in Example 2 show significantly enhanced characteristic aromas, aroma quality, and comfort. In Example 4, the mixed treatment of Yunnan and Henan tobaccos reveals a clear synergistic effect, with Yunnan tobacco providing a sweet base aroma and Henan tobacco enhancing the richness and intensity, resulting in a sensory experience superior to that of a single raw material. Furthermore, it is evident that the pretreatment method of this invention facilitates smooth molecular distillation, further expanding the development prospects of high-end aroma raw materials in tobacco puree.

[0123] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0124] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A pretreatment method for the molecular distillation process of tobacco extract, characterized in that: Includes the following steps: Step S1: Mix the tobacco extract to be molecularly distilled with deionized water, heat and keep warm; Step S2: Add cellulase, pectinase and protease to the liquid obtained in step S1, mix well, and stir for a period of time. Step S3: Add different amounts of ethanol to the liquid obtained in step S2 according to different varieties of tobacco extract, stir evenly, and freeze the liquid. Step S4: Filtration. Take the filtrate and concentrate it under reduced pressure. Pretreatment is complete.

2. The preprocessing method as described in claim 1, characterized in that: In step S1, the tobacco extract to be molecularly distilled includes the following different varieties of tobacco extract: Commercially available crude extracts of Yunnan tobacco, crude extracts of Henan tobacco, and imported Zimbabwean tobacco extract.

3. The preprocessing method as described in claim 1, characterized in that: In step S1, the mass ratio of tobacco extract to deionized water is 1:(2~5).

4. The preprocessing method as described in claim 1, characterized in that: In step S1, the specific operation of heating and holding the temperature is as follows: heating to 45℃~55℃ and maintaining the temperature within this range for 5~20 minutes.

5. The preprocessing method as described in claim 1, characterized in that: In step S2, the amount of cellulase, pectinase and protease added to each 100kg of the liquid obtained in step S1 is 100~500g.

6. The preprocessing method as described in claim 1, characterized in that: In step S2, the stirring temperature is 40~55℃ and the time is 4~6 hours.

7. The preprocessing method as described in claim 1, characterized in that: In step S2, different amounts of ethanol are added to the liquid obtained in step S2 according to different varieties of tobacco extract, including: For crude extraction of tobacco extract, the amount of ethanol added is 3 to 4 times the volume of the liquid obtained in step S2; For crude extraction of tobacco extract, the amount of ethanol added is 1 to 3 times the volume of the liquid obtained in step S2; For imported Zimbabwean tobacco extract, the amount of ethanol added is 2 to 5 times the volume of the liquid obtained in step S2.

8. The preprocessing method as described in claim 1, characterized in that: In step S3, the freezing temperature is -25℃ to -10℃, and the freezing time is 8 to 24 hours.

9. The preprocessing method as described in claim 1, characterized in that: In step S4, the conditions for vacuum concentration include: a vacuum degree of -0.08MPa to -0.095MPa, a feed liquid temperature of below 60℃, and a specific gravity of 1.13 to 1.17 for the concentrated feed liquid.

10. The application of the pretreatment method according to any one of claims 1 to 9 in the molecular distillation process of tobacco extract, characterized in that: Before the molecular distillation process of the tobacco extract, the pretreatment method described in any one of claims 1 to 9 is performed.

Images