Method for improving stability of reconstituted tobacco concentrated solution and application

Abstract

The invention belongs to the technical field of reconstituted tobacco production and processing, and particularly relates to a method for improving stability of a reconstituted tobacco concentrated solution and application. According to the method, the extracting solution obtained from the tobacco raw materials is subjected to multi-stage purification and concentration, the high-concentration concentrated solution and the second-stage condensate water are obtained, the stability of the concentrated solution is improved by adding the stabilizing medium, the concentration of the concentrated solution can be improved, the dispersion stability of macromolecular substances in the refrigeration process can be improved, sedimentation is avoided, and the quality of the macromolecular substances is improved. Meanwhile, high concentration is beneficial to improving the osmotic pressure of the concentrated solution and reducing the activity of microorganisms, compared with a conventional low-temperature preservation mode of the reconstituted tobacco concentrated solution, the method can achieve high-temperature concentrated solution preservation, and the storage time of the concentrated solution can be prolonged to 2 years or above. According to the method, the concentrated high-concentration concentrated solution is compounded with the condensed water containing the aromatic substances, and the compound can be used for preparing reconstituted tobacco cigarette products or adding the cigarette products, so that the quality of the cigarette products is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of reconstituted tobacco production, and in particular relates to a method for improving the stability of reconstituted tobacco concentrate and an application thereof. Background Art

[0002] Reconstituted tobacco, also known as tobacco flakes, is a homogenized tobacco leaf made from tobacco materials such as tobacco dust, tobacco stems, and broken tobacco flakes through processes such as extraction, concentration, pulping, papermaking, coating, and drying.

[0003] As an important means of reducing tar and reducing harm, reconstituted tobacco has been applied more and more widely in cigarettes, and its application ratio is increasing. The product categories of reconstituted tobacco have gradually expanded from the previous three- and four-category cigarettes to the second- and first-category cigarette formulas, and the blending ratio is gradually increasing. The production processes of reconstituted tobacco include roller pressing, thick pulping, and papermaking. Among them, papermaking reconstituted tobacco has low density, low tar, high filling, high quality, and the formula can be manually intervened, which are different from other reconstituted tobacco. It is the most commonly used method at home and abroad. The mainstream papermaking reconstituted tobacco is produced by a two-step method, which can be summarized as separation-recombination. Separation is to use hot water to separate the soluble and insoluble parts of the tobacco raw materials into solid and liquid, the solid part is pulped and made into a base sheet on the paper machine, and the liquid part is concentrated and modulated; recombining is to apply the modulated concentrate on the base sheet, and then dry and slice to complete the preparation of reconstituted tobacco.

[0004] The raw materials of reconstituted tobacco are complex, with many grades and large differences in chemical composition. In order to ensure the quality stability of the product, a certain amount of concentrate is usually required before subsequent production can begin. Affected by the evaporation efficiency of the concentration equipment and in order to ensure the timeliness of the slurry, frozen concentrate is required to maintain the continuity of production operation when the production starts. The frozen concentrate comes from the surplus concentrate in the previous production cycle, and the stability of the effective ingredients is maintained by refrigeration. However, affected by microorganisms and the storage environment, some concentrates will deteriorate during the freezing process and cannot be used. The deterioration and discharge of the concentrate will not only cause the loss of tobacco raw materials, but also increase the wastewater treatment load. In the production process of reconstituted tobacco, the concentration of the concentrate is generally controlled at about 40%. When directly refrigerated, macromolecular substances such as polysaccharides are easy to precipitate, and the precipitated substances are difficult to transfer when used again, resulting in large fluctuations in the chemical composition of the concentrate before and after refrigeration. In addition, in order to improve the combustion performance of reconstituted tobacco leaves, it is usually necessary to add potassium salts of organic acids during the extraction, concentration or modulation process to regulate the combustion behavior of the product. When potassium salts are added before concentration, the concentration evaporator is prone to scaling during the concentration process, affecting the evaporation efficiency; and directly adding potassium salts of organic acids during the modulation of the concentrate is prone to precipitation, which increases the viscosity of the modulated concentrate, thereby affecting the substrate coating effect.

[0005] Therefore, based on the above-mentioned problems existing in the concentrate during the production of reconstituted tobacco by the papermaking method, it is crucial to improve the storage stability of the concentrate and find a process method to provide a concentrate with stable viscosity for the coating process to reduce the waste of tobacco resources and improve the quality stability of reconstituted tobacco products. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the present invention provides a method for improving the stability of reconstituted tobacco concentrate and its application. The extract obtained from tobacco raw materials is subjected to multi-stage purification and concentration to obtain a high-concentration concentrate and secondary condensed water, and then the stability of the concentrate is improved by adding a stabilizing medium. The present invention can increase the concentration of the concentrate. In addition to improving the dispersion stability of macromolecular substances during the cold storage process and avoiding sedimentation, the high concentration is also beneficial to increasing the osmotic pressure of the concentrate and reducing the activity of microorganisms. The concentrate can be preserved at a higher temperature. The concentrated high-concentration concentrate is compounded with condensed water containing flavor substances, which can be used to prepare reconstituted tobacco cigarette products or added to cigarette products, thereby improving the quality of cigarette products.

[0007] Based on the above purpose, the present invention adopts the following technical solutions:

[0008] A method for improving the stability of reconstituted tobacco concentrate, comprising the following steps:

[0009] (1) Obtaining a concentrated solution: extracting soluble matter from tobacco raw materials with an extractant to obtain an extract, and the extract is purified and concentrated to obtain a primary concentrated solution and a primary condensed water;

[0010] (2) Concentration: The concentration (mass fraction) of the primary concentrated solution in step (1) is increased by 10% to 30% by re-concentrating to obtain a high-concentration concentrated solution, and secondary condensed water is collected during the concentration process;

[0011] (3) Adding a stabilizing medium: adding an organic acid to the high-concentration concentrate, and mixing it evenly by ultrasonication to obtain a high-concentration concentrate of reconstituted tobacco leaves, which is then stored in a cold storage for future use;

[0012] (4) Preserving the aroma of aroma components: treating the secondary condensate in step (2) by membrane concentration to obtain a high-concentration condensate containing aroma components;

[0013] (5) Refrigeration: The prepared high-concentration condensate is stored in a cold storage for future use.

[0014] Furthermore, the tobacco raw material in step (1) refers to semi-processed products of flue-cured tobacco leaves, including fragments, scraps, stems, and tobacco stems generated during the redrying or rolling process of flue-cured tobacco leaves.

[0015] Furthermore, the extractant in step (1) is one or more of water, anhydrous ethanol and methanol.

[0016] Furthermore, in step (1), during extraction, a three-stage countercurrent method is used for extraction; during extraction, the solid-liquid mass ratio is 1:(4-8), the extraction temperature is 50-70°C, and the extraction time is 20-60min; other process parameters of the three-stage countercurrent during extraction in step (1) can be conventionally set in the prior art, and are not the inventive point of the present invention, so they are not described in detail.

[0017] Furthermore, in step (1), during the purification treatment, a combination of one or more methods such as filtration, flocculation sedimentation, centrifugation, membrane purification, etc. is adopted; preferably, the purification process of centrifugation + membrane purification is used to remove impurities and macromolecular substances in the extract to avoid precipitation when potassium salt is used for subsequent adjustment.

[0018] Further preferably, in step (1), the pressure during membrane purification is 0.8-1.5 MPa; other process parameters during membrane purification in step (1) can be conventionally set in the prior art, and are not the inventive point of the present invention, so they will not be described in detail.

[0019] Furthermore, in step (1), the concentration (mass fraction) of the primary concentrated solution is 40-45%.

[0020] Furthermore, in step (1) and step (2), the concentration method is preferably evaporation concentration, the concentration temperature is 55-85°C, and the vacuum degree during concentration is (0.03-0.1) MPa; the effect of concentration and enrichment is: increasing the concentration of the concentrated liquid is beneficial to increasing the viscosity of the liquid, enhancing the interaction between solute molecules, and reducing the possibility of precipitation of substances such as sugars during refrigeration. At the same time, high-temperature concentration is beneficial to sterilization of the concentrated liquid; other process parameters of double-effect evaporation concentration in step (1) and step (2) can adopt conventional settings in the prior art, and are not the inventive point of the present invention, so they are not repeated here.

[0021] Furthermore, the organic acid in step (3) is one or more of succinic acid, malic acid, citric acid, etc.; the added mass of the organic acid is 2 to 5 wt % of the high-concentration concentrate.

[0022] Furthermore, in step (3), the frequency of ultrasonic treatment is 20-30 kHz, the power is 100-200 W, the treatment time is 10-20 min, and the treatment temperature is room temperature (25±5° C.).

[0023] Furthermore, in step (3), the storage temperature is -10 to 4°C, preferably -8 to -2°C; before refrigeration, the refrigerated tank body must undergo deep cleaning, sterilization and other treatments to prevent the container microorganisms from contaminating the concentrate; function: to lower the pH of the concentrate, create an environment that is not conducive to the growth of microorganisms, and at the same time, ultrasonically destroy the activity of microorganisms and enzymes.

[0024] Furthermore, in step (4), the concentration multiple is 10-30 times, and the concentration can be carried out by reverse osmosis concentration or adsorption filler enrichment-elution, and the reverse osmosis concentration method is preferred; function: to recover the aroma components transferred to the condensed water during the concentration of the concentrate, so as to maintain the aroma integrity of the concentrate.

[0025] Furthermore, in step (4), during reverse osmosis concentration, the pressure is 2 to 5 MPa.

[0026] Furthermore, in step (5), the storage temperature is -10 to -4°C, preferably -8 to -4°C; Effect: Storing at low temperature can reduce the activity of microorganisms and enzymes.

[0027] Furthermore, based on a general inventive concept, the present invention also provides a reconstituted tobacco leaf high-concentration concentrate prepared by the above method and a corresponding high-concentration condensate.

[0028] Furthermore, based on a general inventive concept, the present invention also provides the use of the reconstituted tobacco high-concentration concentrate in the production of reconstituted tobacco cigarette products.

[0029] Further, based on a general inventive concept, the present invention also provides a method for producing a reconstituted tobacco cigarette product using the reconstituted tobacco high-concentration concentrate, comprising the following steps:

[0030] Step a: compounding: thawing the refrigerated high-concentration condensate, diluting it 2-10 times with clean water, and mixing it with the thawed high-concentration concentrate to obtain a compound concentrate with complete fragrance;

[0031] Step b: adjusting pH with potassium salt or potash: adjusting pH of the composite concentrate to 4.5-5.5 with potassium hydroxide solution or potassium bicarbonate solution;

[0032] Step c: concentration adjustment: according to the production process requirements, the concentration of the compound concentrate is adjusted with clean water; then, the compound concentrate is coated on the substrate, and the reconstituted tobacco cigarette product is prepared through drying, cutting and other processes.

[0033] Specifically, in step a, the mass ratio of the diluted high-concentration condensate to the high-concentration concentrate is 1:(10-20).

[0034] Specifically, in step a, the function of compounding is to obtain a concentrated liquid with complete fragrance.

[0035] Specifically, in step b, the concentration of potassium hydroxide solution or potassium bicarbonate solution is 2-5% (mass fraction); the function of step b is to improve the combustion-supporting property.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention provides a method for improving the stability of reconstituted tobacco concentrate that is simple to operate and easy to run. The present invention improves the concentration of the concentrate by performing multi-stage purification and concentration treatment on the extract obtained from tobacco. In addition to improving the dispersion stability of macromolecular substances during cold storage and avoiding sedimentation, the high concentration is also beneficial to increasing the osmotic pressure of the concentrate and reducing the activity of microorganisms. Compared with the conventional low-temperature storage method of reconstituted tobacco concentrate, the method of the present invention can achieve the preservation of the concentrate at a higher temperature, and the storage time of the concentrate can be increased to more than 2 years. DETAILED DESCRIPTION

[0038] In order to facilitate the understanding of the present invention, the present invention will be described in more comprehensive and detailed manner in combination with the following embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0039] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0040] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0041] Example 1

[0042] A method for improving the stability of reconstituted tobacco concentrate, comprising the following specific steps:

[0043] (1) Obtaining a concentrated solution: using water as an extractant, extracting soluble matter from tobacco raw materials (crushed flue-cured tobacco leaves (2022 Luoyang DB3F fragments)) by a three-stage countercurrent method, the solid-liquid mass ratio during extraction is 1:6, the extraction temperature is 60°C, and the extraction time is 30 min, to obtain a tobacco extract, the extract contains water-soluble substances such as pigments, polysaccharides, nitrogen-containing compounds, organic acids, aldehydes, ketones, phenols, volatile oils, etc., the extract is filtered and separated by a horizontal centrifuge and purified by a 100nm SIC ceramic membrane (the purification pressure is 1.2MPa), the content of suspended matter in the extract is less than 0.05%, the extract is then concentrated by double-effect evaporation, the concentration temperature is 80°C, the vacuum degree during concentration is 0.07MPa, to obtain a primary concentrated solution and a primary condensed water, the concentration (mass fraction) of the primary concentrated solution is 40%;

[0044] The other process parameters of the three-stage countercurrent during extraction in step (1) can be conventionally set in the prior art;

[0045] The other process parameters during the purification process in step (1) can be conventionally set in the prior art;

[0046] (2) Concentration: The concentrated solution in step (1) is concentrated to a concentration (mass fraction) of 55% by double-effect evaporation concentration again at a temperature of 75° C. and a negative pressure of 0.08 MPa. At this time, a high-concentration concentrated solution and secondary condensed water are obtained (the concentrated solution will produce new condensed water during the concentration process, and the condensed water contains tobacco aroma components that escaped during the concentration process); the higher the concentration of the concentrated solution, the more weakly polar tobacco aroma substances will reach saturation in the solution during the concentration process and escape into the condensed water. Therefore, the condensed water after the concentration needs to be collected for subsequent use to ensure the integrity of the aroma;

[0047] The other process parameters of the double-effect evaporation concentration in step (1) and step (2) can be conventionally set in the prior art;

[0048] (3) Treatment of adding a stabilizing medium and a concentrated solution to be refrigerated: adding citric acid to the high-concentration concentrated solution of step (2); the added mass of citric acid is 3 wt % of the high-concentration concentrated solution;

[0049] Then, the product is ultrasonically treated at a frequency of 20kHz, a power of 200W, and a room temperature (25±5°C) for 20 minutes to obtain a high-concentration concentrate of reconstituted tobacco leaves, which is then stored in a cold storage at a temperature of -8 to -2°C.

[0050] (4) Preserving aroma components: The secondary condensed water in step (2) is subjected to reverse osmosis concentration treatment at a pressure of 4 MPa using a reverse osmosis membrane, and the secondary condensed water is concentrated to 20 times to obtain a high-concentration condensate containing aroma components; after testing, the high-concentration condensate can retain about 92% of the aroma components in the secondary condensed water (mainly including: furfural, 2-acetylfuran, benzyl alcohol, phenylethyl alcohol, 2-acetylpyridine, 3-hydroxy-α-damascenone, dihydroactin, pinene alcohol and other low-boiling point tobacco aroma components) compared with the high-concentration condensate before reverse osmosis concentration;

[0051] (5) Refrigeration: The prepared high-concentration condensate is placed in a cold storage at -8°C for storage.

[0052] In this embodiment, the reconstituted tobacco high-concentration concentrate and the corresponding high-concentration condensate are obtained by the above method.

[0053] The prepared high-concentration concentrate of reconstituted tobacco was stored for one year, and then coated, dried, and shredded. After sensory evaluation according to the method in "YC / T497-2014 Sensory Evaluation Method for Chinese Cigarette Style", it was found that the aroma style of the high-concentration concentrate was consistent with that before storage, and the overall smoke characteristics were similar.

[0054] When using, thaw the high-concentration condensate, dilute it 5 times with clean water, and mix it with the high-concentration concentrate in a mass ratio of 8:100 to obtain a compound concentrate with a complete fragrance.

[0055] The volatile components of the compounded concentrated solution after compounding were analyzed by solid phase microextraction-gas chromatography-mass spectrometry. The results showed that the content of volatile components per unit absolute dry mass of the concentrated solution was 98.5% of the unit absolute dry mass before concentration.

[0056] A 2% (mass fraction) potassium hydroxide aqueous solution is used to adjust the pH of the compound concentrate to 4.9. At this time, the amount of the potassium hydroxide aqueous solution used is 6‰ (mass fraction) of the compound concentrate. Clean water is then used to adjust the Baume degree of the compound concentrate after the pH is adjusted to 25°Be, and the concentrate can be used for the preparation of reconstituted tobacco leaf cigarette products or for adding to cigarette tobacco leaves, tobacco shreds and other products.

[0057] Application Examples

[0058] The application method of the compound concentrated solution prepared in Example 1 comprises the following specific steps:

[0059] The three concentrates of sample 1, sample 2 and sample 3 were sniffed and coated on the substrate at the same coating rate of 39%, and then dried, cut and rolled, and then sensory evaluation was performed according to the method in "YC / T 498-2014 Sensory Evaluation Method for Reconstituted Tobacco (Papermaking Method)", and the contents of conventional chemical components in the three concentrates were determined according to "YCT 159-2002 Determination of Water-soluble Sugar in Tobacco and Tobacco Products", "YC_T 468-2013 Determination of Total Alkaloids in Tobacco and Tobacco Products", "YCT 153-2017 Determination of Chlorine Content in Tobacco and Tobacco Products", and "YC / T217-2007 Determination of Potassium in Tobacco and Tobacco Products Continuous Flow Method". The sensory evaluation results are shown in Table 1.

[0060] Among them, sample 1 is a control sample, specifically a concentrated solution produced by adding 2.4wt% potassium citrate to a fresh concentrated solution; sample 2 is a high-concentration condensate obtained by the method of Example 1 and a high-concentration concentrated solution refrigerated and stored for one year, and then compounded to obtain a target compounded concentrated solution for use; sample 3 is a concentrated solution produced by adding 2.4wt% potassium citrate to a fresh concentrated solution after being stored in a cold storage at -8°C for one year.

[0061] Table 1

[0062] sample Sensory description Sample 1 The aroma is good, with obvious natural smoke aroma, medium concentration, moderate strength, and low irritation Sample 2 The natural aroma of tobacco increases, the smell of impurities decreases, the increase in strength is not obvious, and the aftertaste changes little Sample 3 The aroma is rough, the natural smoke aroma is weak, the smoke is thin and soft, and the oral comfort is poor

[0063] It can be found from Table 1 that after applying the method of the present invention, the sensory evaluation result of the product is closer to that of the fresh sample, and it is also helpful to improve the impurity smell. After the conventional method is applied, the aroma of the product is rough, the natural tobacco aroma is weakened, and the oral comfort is poor.

[0064] The changes in chemical composition are shown in Table 2.

[0065] Table 2

[0066]

[0067] As can be seen from Table 2, the water-soluble total sugar content of the concentrate (Sample 3) treated by the conventional method decreased significantly. Although it was stored at low temperature, microorganisms can still degrade the polysaccharide substances. The use of the concentrate will cause the product's oral comfort to deteriorate and the tobacco flavor to weaken. The method of the present invention (Sample 2) can still maintain a relatively stable chemical composition of the concentrate.

[0068] Finally, it should be noted that the above are only preferred embodiments of the present invention and the principles of the application technology. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the specific embodiments described herein, and may include more other effective embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for improving the stability of reconstituted tobacco concentrate, characterized in that: The steps include: (1) Obtaining concentrated liquid: extracting soluble matter from tobacco raw materials with an extractant to obtain an extract, which is then purified and concentrated to obtain a primary concentrated liquid and a primary condensed water; (2) Concentration: The mass fraction of the primary concentrated liquid in step (1) is increased by 10% to 30% by re-concentrating to obtain a high-concentration concentrated liquid, and the secondary condensate is collected during the concentration process; (3) Adding a stabilizing medium: adding an organic acid to the high-concentration concentrate and mixing it evenly by ultrasonication to obtain a high-concentration concentrate of reconstituted tobacco leaves, which is then refrigerated for later use; (4) Preserving aroma components: The secondary condensate in step (2) is treated by membrane concentration to obtain a high-concentration condensate containing aroma components; (5) Refrigeration: Refrigerate the prepared high-concentration condensate for future use.

2. The method for improving the stability of reconstituted tobacco concentrate according to claim 1, characterized in that: The extractant in step (1) is one or more of water, anhydrous ethanol, and methanol; in step (1), the extraction is performed by a three-stage countercurrent method; during the extraction, the solid-liquid mass ratio is 1:(4-8), the extraction temperature is 50-70°C, and the extraction time is 20-60 min.

3. The method for improving the stability of reconstituted tobacco concentrate according to claim 1, characterized in that: In step (1), during the purification treatment, a combination of one or more methods selected from filtration, flocculation sedimentation, centrifugation, and membrane purification is used.

4. The method for improving the stability of reconstituted tobacco concentrate according to claim 1, characterized in that: In step (1) and step (2), the concentration method is evaporation concentration, the concentration temperature is 55-85°C, and the vacuum degree during concentration is (0.03-0.1) MPa.

5. The method for improving the stability of reconstituted tobacco concentrate according to claim 1, characterized in that: The organic acid in step (3) is one or more of succinic acid, malic acid, and citric acid; the added mass of the organic acid is 2-5 wt % of the high-concentration concentrate.

6. The method for improving the stability of reconstituted tobacco concentrate according to claim 1, characterized in that: In step (3), the frequency of ultrasonic treatment is 20-30 kHz, the power is 100-200 W, the treatment time is 10-20 min, and the treatment temperature is room temperature.

7. The method for improving the stability of reconstituted tobacco concentrate according to claim 1, characterized in that: In step (4), the concentration multiple is 10-30 times, and the concentration is carried out by reverse osmosis concentration or adsorption filler enrichment-elution.

8. The reconstituted tobacco high-concentration concentrate prepared by the method according to claims 1-7.

9. Use of the high-concentration concentrated reconstituted tobacco liquid as claimed in claim 8 in the production of reconstituted tobacco cigarette products.

10. A method for producing reconstituted tobacco cigarette products using the reconstituted tobacco high-concentration concentrated liquid according to claim 8, characterized in that: The steps include: Step a: compounding: thawing the refrigerated high-concentration condensate, diluting it 2-10 times with water, and mixing it with the thawed high-concentration concentrate to obtain a compound concentrate with complete fragrance; Step b: adjusting pH with potassium salt or potash: adjusting pH of the composite concentrate to 4.5-5.5 with potassium hydroxide solution or potassium bicarbonate solution; Step c: concentration adjustment: according to the production process requirements, the concentration of the compound concentrated solution is adjusted with water; then, the compound concentrated solution is coated on the substrate, and the reconstituted tobacco cigarette product is prepared through the processes of drying and cutting.

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