Tobacco stem extracting solution treatment process and reconstituted tobacco

Abstract

The invention relates to the technical field of tobacco stem treatment, in particular to a treatment process of a tobacco stem extracting solution and reconstituted tobacco, the treatment process comprises the following steps: S1, adding a composite biological enzyme into a first tobacco stem extracting solution, performing enzymolysis treatment at 45-55 DEG C, performing sterilization treatment at 75-85 DEG C for 25-35 minutes, and cooling to room temperature to obtain an enzymolysis solution; s2, propylene glycol and proline are added into the enzymatic hydrolysate in the step S1, the pH value of a reaction system is adjusted to be 8-10 through an alkaline compound, a reaction is conducted for 2-6 h at the temperature of 100-120 DEG C, then a reaction product is cooled, and a treated second tobacco stem extracting solution can be obtained. The tobacco stem extracting solution obtained by the treatment process provided by the invention has better taste quality, fragrance and coloring effect.

Description

Technical Field

[0001] This invention relates to the technical field of tobacco stem processing, specifically to a process for processing tobacco stem extract and reconstituted tobacco leaves. Background Technology

[0002] Tobacco stems are the coarse, stiff veins of tobacco leaves, accounting for about 25-30% of the leaf weight, and are a major byproduct of the tobacco industry. To reduce the waste of tobacco byproducts such as tobacco stems, an effective way to reuse them is to use them as raw materials in the production of reconstituted tobacco leaves.

[0003] Tobacco stems primarily provide fiber and some base material for coating in reconstituted tobacco. However, tobacco stems contain high levels of macromolecules such as pectin, starch, and protein, which are closely related to the physical structure of the base material, causing changes in the permeability of the base and affecting the combustion performance of reconstituted tobacco. Furthermore, they can lead to an increase in off-flavors in reconstituted tobacco. In addition, untreated tobacco stem extracts contain a significant amount of sugars. These sugars produce more tar during combustion, reducing the function of tobacco flakes in reducing tar release in cigarette formulations. Their high content also results in poor flavor quality and a strong off-flavor, affecting the effectiveness and dosage of tobacco flakes in cigarette manufacturing.

[0004] Therefore, tobacco stem extract should undergo quality improvement treatment before being used in reconstituted tobacco. Several processing techniques for tobacco stem extract have been reported. For example, invention patent CN102396775A provides a processing technique for tobacco stem extract, including: 1) pretreatment of tobacco stems: drying the raw tobacco stems and then pulverizing them into powder; 2) enzymatic treatment of tobacco stems: adding α-amylase and GA to the tobacco stem powder. II. Novozymes cellulase, citrate-sodium citrate buffer, sealed and shaken in a water bath, then add flavor protease, sealed and shaken in a water bath, then inactivated in a water bath, then centrifuged, and the supernatant was collected to obtain tobacco stem extract a; 3) Maillard reaction: the pH of tobacco stem extract a was adjusted to 6.5-8, and distilled. After distillation, heating was stopped first and then water was turned off to stop the reaction, thus obtaining Maillard reactant-tobacco stem extract b; 4) Microbial fermentation treatment: tobacco stem extract b was sterilized, and Angel Yeast and Lactobacillus plantarum LP were inoculated. After fermentation, it was inactivated in a water bath, then centrifuged, and the supernatant was collected to obtain tobacco stem extract c.

[0005] The above method uses enzymatic hydrolysis and compound enzyme treatment, microbial fermentation, and Maillard reaction to process tobacco stems. Enzymatic hydrolysis extracts the tobacco stems to maximize the extraction of carbohydrates such as starch and pectin, as well as macromolecules like proteins. The resulting extract is beneficial for improving the quality of reconstituted tobacco leaves. However, the Maillard reaction in this method is performed under neutral to slightly alkaline conditions (pH 6.5–8), and subsequent microbial fermentation may alter pigment stability, leading to poor coloring results. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a process for processing tobacco stem extract and reconstituted tobacco leaves. The tobacco stem extract processed by the aforementioned process has better taste, aroma, and coloring effects.

[0007] To achieve the above-mentioned objectives, the present invention is implemented through the following technical solution:

[0008] In a first aspect, the present invention provides a process for processing tobacco stem extract, comprising the following steps:

[0009] S1. Add compound biological enzyme to the first tobacco stem extract, perform enzymatic hydrolysis at 45~55℃, then sterilize at 75~85℃ for 25~35min, cool to room temperature to obtain enzymatic hydrolysate;

[0010] S2. Add propylene glycol and proline to the enzymatic hydrolysate in step S1, adjust the pH of the reaction system to 8-10 using an alkaline compound, react at 100-120℃ for 2-6 hours, and then cool the reaction product to obtain the processed second tobacco stem extract.

[0011] This invention treats tobacco stem extract with a complex bioenzyme, degrading macromolecules such as proteins, starches, and pectins to a certain extent, generating smaller reducing sugars and amino acids. The addition of a suitable amount of proline further induces a Maillard reaction in the extract, producing precursors of flavor compounds such as furans, pyrans, pyrroles, and pyrazines, resulting in a significantly improved second tobacco stem extract. Adding this extract in a specific ratio to tobacco sheets significantly enhances the flavor. Furthermore, by setting alkaline conditions, the later stages of the Maillard reaction primarily generate black-like substances, a class of natural products with a wider color range than caramel coloring, ranging from yellow to brownish-red. These substances give the second tobacco stem extract a better coloring effect; coating the tobacco sheets with this extract significantly improves the brightness and redness, making it closer to the color of natural tobacco leaves.

[0012] Preferably, in step S1, the density of the first tobacco stem extract is 1.17~1.20 g / cm³.3 .

[0013] Preferably, in step S1, the reducing sugar content in the first tobacco stem extract is 8-12%, so as to provide a rich sugar source for the Maillard reaction.

[0014] Preferably, in step S1, the complex bioenzyme includes at least one of pectinase, hemicellulase, fungal amylase, glucoamylase, laccase, and protease.

[0015] Preferably, in step S1, the compound bioenzyme comprises, by mass percentage, 0.03% pectinase, 0.01% hemicellulase, 0.05% fungal amylase, 0.02% glucoamylase, 0.05% laccase, and 0.02% protease.

[0016] Preferably, in step S1, the addition of a compound bio-enzyme to the first tobacco stem extract and the enzymatic hydrolysis treatment at 45-55°C includes:

[0017] Add pectinase, hemicellulase, fungal amylase, and glucoamylase and react for 1.5 to 2.5 hours, then add laccase and react for 25 to 35 minutes, and finally add protease and react for 0.5 to 1.5 hours.

[0018] Preferably, in step S2, the ratio of propylene glycol to the water content in the enzymatic hydrolysate is 3:7.

[0019] Preferably, in step S2, the ratio of proline to the total sugar content in the enzymatic hydrolysate is 1:1.

[0020] Preferably, in step S2, the alkaline compound includes at least one of NaOH and KOH.

[0021] In a second aspect, the present invention provides a reconstituted tobacco leaf, which is prepared by coating a second tobacco stem extract as described in any of the preceding claims onto a tobacco substrate.

[0022] Preferably, the second tobacco stem extract is prepared by adding 25% of the second tobacco stem extract to a 75% concentrate, mixing the mixture, and then coating it onto a tobacco substrate; the concentrate is obtained by solvent extraction and concentration of at least one of tobacco stems, tobacco dust, tobacco leaf fragments, and low-grade tobacco leaves.

[0023] The beneficial effects of this invention are as follows:

[0024] The processing technology provided by this invention can degrade macromolecules such as proteins, pectin, and starch in tobacco stems into smaller molecules such as reducing sugars and amino acids, thereby increasing aroma and improving taste. Furthermore, through the Maillard reaction, the processing technology provided by this invention effectively reduces the sugar content in the tobacco stem extract and produces heterocyclic compounds such as furans, pyrans, pyrroles, and pyrazines, significantly increasing the aroma and coloring effect of the tobacco stem extract, thus improving the color of the tobacco sheets and making them closer to the color of tobacco leaves. Detailed Implementation

[0025] The present invention will be further described below with reference to the specification and specific 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.

[0026] Example 1

[0027] Take 500g of untreated first tobacco stem extract as raw material and add it to a reaction flask. First, add 0.15g pectinase, 0.05g hemicellulase, 0.25g fungal amylase, and 0.10g glucoamylase. After mixing, place it in a sterile shaker and react at 50℃ for 2 h. Then add 0.25g laccase, mix, and react at 50℃ for 30 min. Finally, add 0.10g protease, mix, and react at 50℃ for 1 h. Remove and heat in an 80℃ water bath for 30 min to obtain the enzymatic hydrolysate.

[0028] Take 100g of the above enzymatic hydrolysate, add propylene glycol at a ratio of 3:7 (propylene glycol:water), add proline at a molar ratio of 1:1 (reducing sugar to proline), adjust the pH to 8 with NaOH, and react at 100℃ for 2h to obtain the second tobacco stem extract after treatment.

[0029] The volatile aroma components of the second tobacco stem extract were determined using SPME-GC / MS. The SPME used a 50 / 30 μm DVB / CAR / PDMS extraction head, and the GC / MS method employed an HP-5MS (30 m × 0.25 mm × 0.25 μm) capillary column. Specific parameter settings were as follows: injection port temperature: 250℃; carrier gas: high-purity He, flow rate: 1.0 mL / min; manual injection; temperature program: 40℃ for 5 min, then increased to 280℃ at a rate of 5℃ / min, and held for 5 min; transfer line temperature: 280℃; ion source temperature: 230℃, quadrupole temperature: 150℃; ionization mode: EI source; ionization energy: 70 eV; scan mode: full scan; mass scan range m / z: 35–450 amu. Quadrature analysis was performed using the NIST14.L and Wiley7n.L standard libraries.

[0030] Tests showed that the volatile aroma components in the second tobacco stem extract obtained after the processing were significantly increased, about three times that of the untreated tobacco stem concentrate. In addition, a large amount of pyrazine and pyridine substances were generated, such as 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-6-methyl-pyrazine, 2-ethyl-3-methyl-pyrazine, 2-acetylpyridine, and 2-acetyl-4-methylpyridine. Furthermore, the processed tobacco stem extract had a distinct sweet caramel aroma.

[0031] Preparation of reconstituted tobacco

[0032] The second tobacco stem extract after the above treatment was added to the 75% concentrate at a ratio of 25%, mixed and coated onto a tobacco substrate, and reconstituted tobacco leaf A was prepared according to conventional processing technology; the concentrate was obtained by solvent extraction and concentration of tobacco stems, tobacco dust, tobacco leaf fragments and low-grade tobacco leaves.

[0033] Untreated first tobacco stem extract was added at a ratio of 25% to 75% concentrate, mixed, and then coated onto tobacco substrate to prepare reconstituted tobacco leaf B. Comparing the smoking results of reconstituted tobacco leaf A and reconstituted tobacco leaf B, reconstituted tobacco leaf A showed reduced bitterness and astringency, increased aroma quality and aroma quantity, and an overall significantly better smoking experience than reconstituted tobacco leaf B.

[0034] The colors (Lab values) of reconstituted tobacco leaf A, reconstituted tobacco leaf B, and reconstituted tobacco leaf C prepared from 100% concentrate were compared. The results showed that the color of reconstituted tobacco leaf A was significantly different from that of reconstituted tobacco leaf B and reconstituted tobacco leaf C, especially in terms of brightness and redness, it was closer to the color of tobacco leaf, as shown in Table 1.

[0035] Example 2

[0036] The process is basically the same as in Example 1, except that the pH value is adjusted to 9 with NaOH and the reaction is carried out at 110°C for 4 hours to obtain the second tobacco stem extract after treatment.

[0037] The volatile aroma components increased significantly, approximately five times that of untreated tobacco stem concentrate.

[0038] Example 3

[0039] The process is basically the same as in Example 1, except that the pH value is adjusted to 10 with NaOH and the reaction is carried out at 120°C for 6 hours to obtain the second tobacco stem extract after treatment.

[0040] The volatile aroma components increased significantly, approximately six times that of untreated tobacco stem concentrate.

[0041] Table 1. Comparison of colors (Lab values) in different embodiments

[0042] .

Claims

1. A processing method for tobacco stem extract, characterized in that, Includes the following steps: S1. Add compound biological enzyme to the first tobacco stem extract, perform enzymatic hydrolysis at 45~55℃, then sterilize at 75~85℃ for 25~35min, cool to room temperature to obtain enzymatic hydrolysate; S2. Add propylene glycol and proline to the enzymatic hydrolysate in step S1, adjust the pH of the reaction system to 8-10 using an alkaline compound, react at 100-120℃ for 2-6 hours, and then cool the reaction product to obtain the processed second tobacco stem extract.

2. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S1, the density of the first tobacco stem extract is 1.17~1.20 g / cm³. 3 .

3. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S1, the reducing sugar content in the first tobacco stem extract is 8-12%.

4. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S1, the complex bioenzyme includes at least one of pectinase, hemicellulase, fungal amylase, glucoamylase, laccase, and protease.

5. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S1, the addition of a compound bio-enzyme to the first tobacco stem extract and the enzymatic hydrolysis treatment at 45-55°C includes: Add pectinase, hemicellulase, fungal amylase, and glucoamylase and react for 1.5 to 2.5 hours, then add laccase and react for 25 to 35 minutes, and finally add protease and react for 0.5 to 1.5 hours.

6. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S2, the ratio of propylene glycol to water content in the enzymatic hydrolysate is 3:

7.

7. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S2, the ratio of proline to the total sugar content in the enzymatic hydrolysate is 1:

1.

8. The processing method for tobacco stem extract according to claim 1, characterized in that, In step S2, the alkaline compound includes at least one of NaOH and KOH.

9. A reconstituted tobacco leaf, characterized in that, It is prepared by coating the second tobacco stem extract as described in any one of claims 1-8 onto a tobacco substrate.

10. The reconstituted tobacco leaf according to claim 9, characterized in that, The second tobacco stem extract was prepared by adding 25% of the second tobacco stem extract to a 75% concentrate, mixing the mixture, and then coating it onto tobacco sheets. The concentrate was obtained by solvent extraction and concentration of at least one of tobacco stems, tobacco dust, tobacco leaf fragments, and low-grade tobacco leaves.