Preparation method of vitamin B1 microcapsule and application of vitamin B1 microcapsule in cigarettes

Abstract

The invention belongs to the technical field of cigarette additives, and particularly relates to a preparation method of a vitamin B1 microcapsule and application of the vitamin B1 microcapsule in cigarettes, and the method mainly comprises the following steps: adding vitamin B1 into a chitosan aqueous solution in proportion; then adding the solution into liquid paraffin containing an emulsifier, and emulsifying under a constant temperature condition to form a stable water-oil emulsion; then, adding a glutaraldehyde aqueous solution into the emulsion, and reacting under high-speed stirring to form a primary microcapsule wall structure, so as to obtain a crude product; and finally, carrying out centrifugal separation, sequentially cleaning with petroleum ether, ethanol and water, and drying and precipitating to obtain the final vitamin B1 microcapsule. The method is easy and convenient to operate, the preparation process is mild, the microcapsule form is regular, the stability and the controlled release performance of the vitamin B1 can be improved, and the cigarette quality can be remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of cigarette additives, and in particular relates to a method for preparing vitamin B1 microcapsules and application thereof in cigarettes. Background Art

[0002] As consumer consumption habits change, consumers' demand for cigarette products has shifted from aroma satisfaction to smoking comfort and taste. Tobacco flavors and fragrances have made outstanding contributions in regulating smoke comfort and taste. How to develop and apply flavors and fragrances that can enhance product comfort and taste has become one of the key directions of tobacco flavors and fragrances development in recent years.

[0003] Vitamin B1, also known as thiamine, has a chemical name of 3-[(4-amino-2-methyl-5-pyrimidinyl)-methyl]-5-(2-hydroxyethyl)-4-methylthiazolium chloride hydrochloride, and is the earliest water-soluble vitamin purified by humans. Its unique chemical structure gives it multiple functions. For example, the thermal decomposition of vitamin B1 will generate a variety of small molecule compounds, most of which have a special aroma. In addition, the amino and hydroxyl groups in the vitamin B1 molecule can theoretically combine with the acidic components in the smoke through hydrogen bonding, thereby effectively reducing the acidic stimulation. In addition, the alkalinity displayed by the pyrimidine ring helps to neutralize excess acidic substances and alleviate the burning sensation of smoke in the oral mucosa. At the same time, the amino group of vitamin B1 can undergo a Maillard reaction with the reducing sugar in tobacco under heating conditions to generate flavor substances such as pyrazine and pyrrole, further enhancing the sweetness and layering of the smoke. In general, relying on the pyrimidine-thiazole bicyclic structure and its active functional groups, vitamin B1 can significantly improve the sensory quality of cigarettes through multiple mechanisms such as pyrolysis aroma production, acid-base balance regulation and anti-oxidation.

[0004] However, although vitamin B1 is relatively stable in an acidic environment, it is easy to decompose under neutral or alkaline conditions. When the pH value is greater than 7 or under heat conditions, most or even all of the vitamin B1 will decompose, resulting in serious loss of vitamin B1 before it participates in combustion and exerts its efficacy in tobacco flavoring formulas, thus greatly limiting its application range. Based on this, in theory, vitamin B1 can be protected by using microencapsulation technology, but due to its small molecular weight, it may be difficult to effectively prevent it from penetrating the microcapsule wall using conventional encapsulation technology. In addition, the high polarity, heat sensitivity and functional group reactivity of vitamin B1 also pose new challenges to the regularity of microcapsules.

[0005] In order to solve the above problems, the present invention is proposed. Summary of the invention

[0006] With respect to the existing microcapsule technology, there is no targeted research on the embedding of vitamin B1, and if conventional technology is used to embed vitamin B1, there are generally problems of low embedding rate and poor roundness. The present invention provides a method for preparing vitamin B1 microcapsules, which selects chitosan as a wall material and a specific content of glutaraldehyde as a cross-linking agent, and prepares vitamin B1 microcapsules through emulsification and cross-linking reactions under specific process conditions. The method of the present invention has the advantages of simple operation, mild preparation process, relatively regular microcapsule morphology, and helps to improve the stability and controlled release performance of vitamin B1.

[0007] The first aspect of the present invention provides a method for preparing vitamin B1 microcapsules, the preparation method comprising the following steps:

[0008] Step (1), adding vitamin B1 to a chitosan aqueous solution of a certain concentration in proportion, stirring evenly, to obtain a chitosan aqueous solution containing vitamin B1;

[0009] Step (2), adding the chitosan aqueous solution containing vitamin B1 prepared in step (1) to liquid paraffin containing an emulsifier in proportion, and performing emulsification treatment at a constant temperature for a period of time to form a stable water-oil emulsion;

[0010] Step (3), adding a certain amount of glutaraldehyde aqueous solution to the water-oil emulsion obtained in step (2), and reacting under high-speed stirring to form a preliminary microcapsule wall structure, thereby obtaining a crude product containing vitamin B1 microcapsules, wherein glutaraldehyde is used as a cross-linking agent to cross-link chitosan molecules to form a preliminary microcapsule wall structure;

[0011] Step (4), centrifuging the crude product obtained in step (3), collecting the precipitate, and then washing the precipitate with petroleum ether, ethanol and water in sequence to remove residual solvent, unreacted substances and oil phase, and drying the washed precipitate to obtain the vitamin B1 microcapsule.

[0012] Preferably, in step (1), the concentration of the chitosan aqueous solution is 2%; and the mass ratio of vitamin B1 to chitosan is 1:1-2:1.

[0013] Preferably, the content of the emulsifier in the liquid paraffin is 2.5%; the emulsifier is Span 80; and the volume ratio of the chitosan aqueous solution containing vitamin B1 to the liquid paraffin containing the emulsifier is 1:6-1:10.

[0014] Preferably, in step (2), the emulsification is carried out in a constant temperature water bath at 40-70° C. and under stirring conditions of 600-900 rpm for 20-60 min to form a stable water-oil emulsion.

[0015] Preferably, the water-oil emulsion and 25% glutaraldehyde aqueous solution are mixed in a volume ratio of 200:1-200:4, and stirred at a rate of 1000-1500 rpm for 2-6 hours to obtain a crude product containing vitamin B1 microcapsules.

[0016] Preferably, in step (4), the crude product is centrifuged at 2000-5000 rpm for 5-10 min and vacuum dried at room temperature.

[0017] The second invention of the present invention provides an application of the vitamin B1 microcapsules prepared by the preparation method of the first aspect in cigarettes, wherein the vitamin B1 microcapsules are dissolved in 50-degree sorghum wine to prepare a solution with a concentration of 0.2-2%, and the solution is evenly sprayed on the surface of the tobacco in the feeding process at a ratio of 0.005-0.02% of the weight of the tobacco;

[0018] The prepared cigarettes not only effectively reduce irritation during smoking, significantly improve the comfort and taste during smoking, but also show excellent effects in blending tobacco aroma, enhancing sweetness and reducing residual aftertaste.

[0019] The present invention has the following beneficial effects:

[0020] 1. The present invention selects chitosan as the wall material and strictly sets the mass ratio of vitamin B1 to chitosan. Ultimately, while achieving a significant increase in the embedding rate of the core material, chitosan and vitamin B1 have good compatibility and are more coordinated with the tobacco flavor.

[0021] 2. The present invention uses chitosan as the wall material and 2.5% glutaraldehyde aqueous solution as a cross-linking agent to significantly improve the embedding rate. The main reason may be that the free amino groups on the chitosan molecular chain react with the aldehyde groups of glutaraldehyde to form stable covalent bonds and construct a three-dimensional cross-linked network. The cross-linked network enhances the density of the chitosan film, reduces the pores of the microcapsule, and prevents the leakage of vitamin B1 during the emulsification or curing stage, thereby improving the embedding rate.

[0022] 3. The 2.5% glutaraldehyde aqueous solution of the present invention as a cross-linking agent significantly improves the roundness of vitamin B1. The main reason may be that glutaraldehyde cross-linking triggers the directional shrinkage of the chitosan molecular chain, eliminates the non-spherical droplets formed in the emulsification stage, and promotes the microcapsules to approach spherical shape. The energy released by the cross-linking reaction promotes the homogenization of the droplet surface tension and reduces morphological defects.

[0023] 4. The vitamin B1 microcapsules of the present invention are applied to cigarettes, which can improve the comfort of cigarettes and reduce the irritation of smoke without affecting the style characteristics of cigarettes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is a microscope magnified image of the vitamin B1 microcapsules prepared by the method of the present invention in Example 1. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the accompanying drawings and embodiments are not intended to limit the technical solutions of the present invention.

[0026] Example 1

[0027] This embodiment provides a method for preparing vitamin B1 microcapsules, comprising the following steps:

[0028] Step (1), adding 1 g of vitamin B1 to 50 mL of a 2% chitosan aqueous solution, stirring at room temperature to obtain a chitosan aqueous solution containing vitamin B1;

[0029] Step (2), adding the chitosan aqueous solution containing vitamin B1 prepared in step (1) to 400 g of liquid paraffin containing 2.5% Span 80, and emulsifying at a constant temperature of 60° C. in a water bath and a stirring rate of 900 rpm for 20 min to form a stable water-oil emulsion;

[0030] Step (3), adding 3.5 mL of 25% glutaraldehyde aqueous solution to the water-oil emulsion prepared in step (2), stirring at a rate of 1200 rpm for 2 hours for solidification, and obtaining a crude product containing vitamin B1 microcapsules;

[0031] Step (4), centrifuging the crude product obtained in step (3) at a speed of 5000 rpm, collecting the precipitate, and then washing the precipitate three times with petroleum ether, ethanol and water in an amount twice the mass of the precipitate to remove residual solvent, unreacted substances and oil phase, collecting the precipitate, and vacuum drying the washed precipitate at room temperature for 24 hours to obtain the vitamin B1 microcapsules with an embedding rate of 85%, numbered as sample #1.

[0032] Example 2

[0033] This embodiment provides a method for preparing vitamin B1 microcapsules, comprising the following steps:

[0034] Step (1), adding 2 g of vitamin B1 into 50 mL of a 2% chitosan aqueous solution, stirring at room temperature to obtain a chitosan aqueous solution containing vitamin B1;

[0035] Step (2), adding the chitosan aqueous solution containing vitamin B1 prepared in step (1) to 400 g of liquid paraffin containing 2.5% Span 80, and emulsifying at a constant temperature of 40° C. in a water bath and a stirring rate of 600 rpm for 20 min to form a stable water-oil emulsion;

[0036] Step (3), adding 2 mL of 25% glutaraldehyde aqueous solution to the water-oil emulsion prepared in step (2), stirring at a rate of 1000 rpm for 2 hours for solidification, and obtaining a crude product containing vitamin B1 microcapsules;

[0037] Step (4), centrifuging the crude product obtained in step (3) at a speed of 2000 rpm, collecting the precipitate, and then washing the precipitate three times with petroleum ether, ethanol and water in an amount twice the mass of the precipitate to remove residual solvent, unreacted substances and oil phase, collecting the precipitate, and vacuum drying the washed precipitate at room temperature for 24 hours to obtain the vitamin B1 microcapsules with an embedding rate of 87%, numbered as sample 2#.

[0038] Example 3

[0039] This embodiment provides a method for preparing vitamin B1 microcapsules, comprising the following steps:

[0040] Step (1), adding 1.5 g of vitamin B1 into 50 mL of a 2% chitosan aqueous solution, stirring at room temperature to obtain a chitosan aqueous solution containing vitamin B1;

[0041] Step (2), adding the chitosan aqueous solution containing vitamin B1 prepared in step (1) to 400 g of liquid paraffin containing 2.5% Span 80, and emulsifying at a constant temperature of 70° C. in a water bath and at a stirring rate of 900 rpm for 60 min to form a stable water-oil emulsion;

[0042] Step (3), adding 4 mL of 25% glutaraldehyde aqueous solution to the water-oil emulsion prepared in step (2), stirring at a rate of 1500 rpm for 6 hours for solidification, and obtaining a crude product containing vitamin B1 microcapsules;

[0043] Step (4), centrifuging the crude product obtained in step (3) at a speed of 3000 rpm, collecting the precipitate, and then washing the precipitate three times with petroleum ether, ethanol and water in an amount twice the mass of the precipitate to remove residual solvent, unreacted substances and oil phase, collecting the precipitate, and vacuum drying the washed precipitate at room temperature for 24 hours to obtain the vitamin B1 microcapsules with an embedding rate of 83%, numbered as sample #3.

[0044] Application Example 1

[0045] In this application example, pure vitamin B1 and the vitamin B1 microcapsule samples 1# to 3# prepared in Examples 1 to 3 were respectively dissolved in 50% kaoliang wine to a concentration of 2%, and then added to the surface of the tobacco by spraying at a concentration of 0.005-0.02% of the weight of the tobacco;

[0046] Then, it was further made into cigarette products according to conventional means for sensory quality evaluation (evaluated according to GB5606.4-2005), and the results are shown in Table 1:

[0047] Table 1 Sensory quality evaluation table

[0048]

[0049]

[0050] As can be seen from Table 1, compared with cigarettes directly added with pure vitamin B1, cigarettes added with vitamin B1 microcapsules have less odor, less irritation, better taste, and a clean and comfortable aftertaste.

[0051] Test Example 1

[0052] In order to further test the characteristics of the vitamin B1 microcapsules prepared by the method of the present invention and verify their long-term stability under high temperature and high humidity conditions, this test example conducted an accelerated test on sample 1# at 40°C ± 2°C and 75% ± 5% temperature and humidity conditions, and regularly sampled and tested at 0, 3, 6, and 12 months. The test items included: VB1 retention rate (%), embedding rate (%), particle size Span value, SEM observation of surface morphology, and the specific test results are shown in Table 2 below:

[0053] Table 2 Stability test results

[0054]

[0055] Among them, the VB1 retention rate (%) adopts HPLC method, and the test conditions are: chromatographic conditions: C18 column, mobile phase 0.05M potassium dihydrogen phosphate (pH 3.0)-methanol (95:5), detection wavelength 246nm. Calculation: retention rate (%) = (VB1 content after storage / initial VB1 content) × 100%;

[0056] The embedding rate (%) was determined by solvent extraction method: the microcapsules were destroyed with pH 7.4 PBS, and the free VB1 and total VB1 contents were determined. Embedding rate (%) = (total VB1 - free VB1) / total VB1 × 100%;

[0057] The particle size Span value is determined by laser diffraction method;

[0058] The surface morphology was observed by SEM.

[0059] Simultaneously, in addition to testing the stability of its physical indicators, this test example also dissolves 1# to 3# samples in 50% kaoliang wine to a concentration of 2%, and then adds 0.02% of the mass of tobacco to the surface of the tobacco by spraying in the feeding process according to the optimal addition amount corresponding to Table 1. Then, it is further made into cigarette products by conventional means for sensory quality evaluation to evaluate the changes in its sensory quality. The evaluation results are shown in Table 3 below:

[0060] Table 3 Sensory quality evaluation table

[0061]

[0062] Conclusion: It can be seen that the B1 microcapsules prepared by the method of the present invention can be stably stored for ≥12 months under high temperature and high humidity conditions, and from the test results of the storage time of 0 month, it can be concluded that the embedding rate of the B1 microcapsules of the present invention is not less than 80%, and the particle size Span value is less than 1.2.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing vitamin B1 microcapsules, characterized in that: The preparation method comprises the following steps: Step (1), adding vitamin B1 to a chitosan aqueous solution of a certain concentration in proportion, stirring evenly, to obtain a chitosan aqueous solution containing vitamin B1; Step (2), adding the chitosan aqueous solution containing vitamin B1 prepared in step (1) to liquid paraffin containing an emulsifier in proportion, and performing emulsification treatment at a constant temperature for a period of time to form a stable water-oil emulsion; Step (3), adding a certain amount of glutaraldehyde aqueous solution to the water-oil emulsion obtained in step (2), and reacting under high-speed stirring to form a preliminary microcapsule wall structure, thereby obtaining a crude product containing vitamin B1 microcapsules; Step (4), centrifuging the crude product obtained in step (3), collecting the precipitate, then washing the precipitate with petroleum ether, ethanol and water in sequence, and drying the washed precipitate to obtain the vitamin B1 microcapsules.

2. The method for preparing vitamin B1 microcapsules according to claim 1, characterized in that: In the step (1), the concentration of the chitosan aqueous solution is 2%; The mass ratio of the vitamin B1 to chitosan is 1:1-2:

1.

3. The method for preparing vitamin B1 microcapsules according to claim 1, characterized in that: In the step (2), the content of the emulsifier in the liquid paraffin is 2.5%; the emulsifier is Span 80; The volume ratio of the chitosan aqueous solution containing vitamin B1 to the liquid paraffin containing the emulsifier is 1:6-1:

10.

4. The method for preparing vitamin B1 microcapsules according to claim 1, characterized in that: In the step (2), emulsification is performed for 20 to 60 minutes in a constant temperature water bath at 40 to 70° C. and under stirring conditions of 600 to 900 rpm to form a stable water-oil emulsion.

5. The method for preparing vitamin B1 microcapsules according to claim 1, characterized in that: In step (3), the water-oil emulsion and 25% glutaraldehyde aqueous solution are mixed in a volume ratio of 200:1-200:4, and stirred at a rate of 1000-1500 rpm for 2-6 hours to obtain a crude product containing vitamin B1 microcapsules.

6. The method for preparing vitamin B1 microcapsules according to claim 1, characterized in that: In the step (4), the crude product is centrifuged at 2000-5000 rpm for 5-10 min and vacuum dried at room temperature.

7. Use of the vitamin B1 microcapsules prepared by the preparation method according to any one of claims 1 to 6 in cigarettes, characterized in that: Dissolve the vitamin B1 microcapsules in 50% kaoliang wine to prepare a solution with a concentration of 0.2-2%, and evenly spray it on the surface of the tobacco in the feeding process at a ratio of 0.005-0.02% of the weight of the tobacco; The prepared cigarettes not only effectively reduce irritation during smoking, significantly improve the comfort and taste during smoking, but also show excellent effects in blending tobacco aroma, enhancing sweetness and reducing residual aftertaste.

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