Reconstituted tobacco preparation method and application thereof

Abstract

The invention relates to the technical field of tobacco sheets, and particularly discloses a reconstituted tobacco preparation method which comprises the following steps: 1) performing delignification treatment on tobacco powder, and drying to obtain absolutely dry delignified tobacco powder; 2) mixing the absolutely dry delignified tobacco powder with glycerol, and extruding to obtain a first mixed material; 3) adding citric acid into the first mixed material for soaking to obtain a second mixed material; 4) homogenizing the second mixed material to obtain a nanocellulose dispersion liquid; 5) carrying out hot water extraction treatment on the absolutely dry tobacco stems, filtering water, drying, defibrating and pulping to obtain tobacco stem pulp; and (6) adding the nanocellulose dispersion liquid into the tobacco stem pulp, mixing, and preparing the reconstituted tobacco through a sheet making machine.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco sheets, and in particular to a method for preparing reconstituted tobacco leaves. Background Art

[0002] Reconstituted tobacco is a tobacco product made from tobacco waste in cigarette production, processed and reorganized using papermaking technology. It has the characteristics of low density, high filling value, excellent processability, and strong plasticity of the product's intrinsic quality and style characteristics. Driven by the goal of improving the quality of Chinese cigarette products, the production technology and quality of reconstituted tobacco have developed rapidly. In recent years, it has developed into an important raw material for Chinese cigarettes.

[0003] At present, the reconstituted tobacco production industry adopts the "separation before combination" process, that is, the tobacco raw materials are first extracted with hot water to achieve solid-liquid separation, and then the liquid phase is removed from impurities, concentrated, and flavored to form a coating liquid, and the solid phase is pulped, fiberized, filled, and papered to form a sheet; then the coating liquid is applied to the sheet base through a coating process to achieve reorganization, and then dried and cut to form reconstituted tobacco.

[0004] Mechanical strength and bulk are important indicators of reconstituted tobacco leaves. Good mechanical strength can reduce the number of breaks of reconstituted tobacco leaves during the production process, improve production efficiency, and reduce the labor intensity of operators, while higher bulk can improve the combustion performance of reconstituted tobacco leaves. Reconstituted tobacco leaves prepared from pure tobacco fibers have low mechanical strength and bulk, and are prone to breakage and tearing during the production process, and are prone to incomplete combustion during the combustion process. Therefore, the industry often uses methods such as adding wood pulp fibers to improve the mechanical strength and bulk of reconstituted tobacco leaves. However, the addition of wood pulp fibers will increase woodiness and significantly damage the taste of reconstituted tobacco leaves. Nanocellulose has a higher specific surface area, a larger Young's mode, and a stronger surface activity. Therefore, the industry also uses nanocellulose to replace wood pulp and add it to reconstituted tobacco leaves to enhance the mechanical strength and bulk of reconstituted tobacco leaves. However, in the prior art, the process of preparing nanocellulose using the TEMPO oxidation method is more complicated, the diameter distribution range of nanocellulose prepared using the mechanical grinding process is larger, and the nanocellulose prepared using the concentrated acid hydrolysis method is often not used in the food industry. In addition, the nanocellulose currently added to reconstituted tobacco is mostly prepared from wood raw materials. After being added to reconstituted tobacco, it will still bring woody smell and thus destroy the taste.

[0005] Therefore, it is of great research significance to find a method for preparing reconstituted tobacco leaves with enhanced mechanical strength and bulk while not significantly damaging the taste. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of this application is to provide a method for preparing reconstituted tobacco leaves with enhanced mechanical properties and improved bulk by nanocellulose. A nanocellulose dispersion prepared from tobacco waste tobacco stems as raw materials is added to the slurry prepared from tobacco waste tobacco stalks as raw materials. The mechanical strength and bulk of the reconstituted tobacco leaves obtained by papermaking are effectively improved compared to when no nanocellulose dispersion is added, but the taste of the reconstituted tobacco leaves is not significantly damaged, and the reuse of tobacco waste is also achieved.

[0007] The present application provides a method for preparing reconstituted tobacco, comprising the following steps: 1) subjecting tobacco dust to delignification treatment, drying, and obtaining absolutely dry delignified tobacco dust; 2) mixing the absolutely dry delignified tobacco dust with glycerin, and extruding, to obtain a first mixed material; 3) soaking the first mixed material in citric acid to obtain a second mixed material; 4) homogenizing the second mixed material to obtain a nanocellulose dispersion; 5) subjecting absolutely dry tobacco stems to hot water extraction treatment, filtering water, drying, defibration, and pulping to obtain tobacco stem slurry; 6) adding the nanocellulose dispersion to the tobacco stem slurry, mixing, and obtaining reconstituted tobacco by a sheet making machine.

[0008] The present application also provides the application of the above-mentioned preparation method in enhancing the mechanical properties of reconstituted tobacco leaves and improving the bulk thickness of reconstituted tobacco leaves.

[0009] The beneficial effects brought by this specification include but are not limited to: (1) The raw materials used in the reconstituted tobacco leaves with enhanced mechanical properties and improved bulk provided by the present invention are tobacco stems and tobacco dust from tobacco waste, which can realize the recycling of tobacco resources; the tobacco dust is firstly extracted with potassium carbonate aqueous solution to remove part of the lignin, which is beneficial to improve the taste; the potassium carbonate used is a weak base and is food grade, which can reduce the irritation of delignification and is harmless to the human body; the tobacco stems are firstly extracted with hot water to remove part of the impurities, harmful components and non-tobacco components, which is beneficial to improve the taste; the food grade glycerol used can enhance the aroma components in the smoke and reduce the irritation, which is beneficial to improve the taste; the citric acid used is food grade, edible and harmless to the human body. (2) The preparation process of the reconstituted tobacco leaves with enhanced mechanical properties and improved bulk provided by the present invention is simple and is a commonly used process in the papermaking or reconstituted tobacco industry, and can be achieved using existing equipment. (3) The reconstituted tobacco leaves provided by the present invention have mechanical properties enhanced and bulk improved by nanocellulose, and their tensile strength and bulk are significantly improved compared to reconstituted tobacco leaves without the addition of additional fibers, thereby effectively reducing the amount of wood pulp fibers used, while having less wood odor and not significantly affecting the taste. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present application will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not restrictive, and include:

[0011] Figure 1 This is a process flow chart for preparing reconstituted tobacco leaves with enhanced mechanical properties and improved bulk through nanocellulose according to one embodiment of the present invention.

[0012] Figure 2 This is a SEM image of nanocellulose obtained in one embodiment of the present invention.

[0013] Figure 3 The SEM image of the nanocellulose obtained in Example 1 of the present invention and the image of the reconstituted tobacco product.

[0014] Figure 4 The SEM image of the nanocellulose obtained in Example 2 of the present invention and the image of the reconstituted tobacco product. DETAILED DESCRIPTION

[0015] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0016] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0017] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0018] The present application provides a method for preparing reconstituted tobacco, comprising the following steps: 1) subjecting tobacco dust to delignification treatment, drying, and obtaining absolutely dry delignified tobacco dust; 2) mixing the absolutely dry delignified tobacco dust with glycerin, and extruding, to obtain a first mixed material; 3) soaking the first mixed material in citric acid to obtain a second mixed material; 4) homogenizing the second mixed material to obtain a nanocellulose dispersion; 5) subjecting absolutely dry tobacco stems to hot water extraction treatment, filtering water, drying, defibration, and pulping to obtain tobacco stem slurry; 6) adding the nanocellulose dispersion to the tobacco stem slurry, mixing, and obtaining reconstituted tobacco by a sheet making machine.

[0019] In some embodiments, in step 1), the tobacco powder may be delignified using an aqueous solution of potassium carbonate. In some embodiments, preferably, the potassium carbonate may be food grade. In some embodiments, more preferably, the concentration of the aqueous solution of potassium carbonate may be 70 to 80 g / L. For example, the concentration of the aqueous solution of potassium carbonate may be about 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 or 80 g / L. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. In some embodiments, further preferably, the concentration of the aqueous solution of potassium carbonate may be 75.3 g / L.

[0020] In some embodiments, preferably, the absolute dry weight of tobacco dust: the weight of potassium carbonate aqueous solution can be 1: (1-3). In some embodiments, more preferably, the absolute dry weight of tobacco dust: the weight of potassium carbonate aqueous solution can be 1: 2.

[0021] In some embodiments, in the step 1), the treatment temperature of the delignification treatment can be 85 to 95°C, and the time can be 15 to 25 minutes. For example, the treatment temperature can be about 85, 86, 87, 88, 89, 90, 91, 92, 93, 94 or 95°C. It also includes any range characterized by a combination of the above end values, which will not be repeated here. For example, the treatment time can be about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 minutes. It also includes any range characterized by a combination of the above end values, which will not be repeated here. In some embodiments, in the step 1), preferably, the treatment temperature can be 90°C and the time can be 20 minutes.

[0022] In some embodiments, in step 1), before drying, lignin, remaining chemicals and impurities are washed to remove, and excess water is filtered out.

[0023] In some embodiments, in the step 1), the drying temperature may be 105-115°C, and the drying time may be 1.5-2.5h. For example, the drying temperature may be about 105, 106, 107, 108, 109, 110, 111, 112, 113, 114 or 115°C. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. For example, the drying time may be about 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5h. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. In some embodiments, in the step 1), preferably, the drying temperature may be 110°C, and the drying time may be 2h.

[0024] In some embodiments, in step 2), the glycerol may be food grade glycerol.

[0025] In some embodiments, the mass ratio of the absolute dry delignified tobacco dust to the glycerin can be 1:(1-2). In some embodiments, preferably, the mass ratio of the absolute dry delignified tobacco dust to the glycerin can be 1:2.

[0026] In some embodiments, an oil press can be used for mechanical extrusion. In some embodiments, preferably, a twin-screw oil press can be used for mechanical extrusion.

[0027] In some embodiments, the number of extrusions may be 1 to 3 times. In some embodiments, preferably, the number of extrusions may be 2 times.

[0028] In some embodiments, in step 3), the concentration of citric acid can be 90-130 g / L. For example, the concentration of citric acid can be about 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128 or 130 g / L. It also includes any range characterized by a combination of the above end values, which will not be repeated here. In some embodiments, preferably, the concentration of citric acid can be 111 g / L.

[0029] In some embodiments, the mass ratio of citric acid to absolute dry delignified tobacco dust can be 3% to 7%. In some embodiments, the mass ratio of citric acid to absolute dry delignified tobacco dust can be 4% to 6%. In some embodiments, preferably, the mass ratio of citric acid to absolute dry delignified tobacco dust can be 5%.

[0030] In some embodiments, in the step 3), the soaking temperature may be 80-100°C, and the soaking time may be 1.5-2.5h. For example, the soaking temperature may be about 80, 82, 84, 86, 88, 90, 92, 94, 96, 98 or 100°C. Any range characterized by a combination of the above-mentioned end values ​​is also included, which will not be repeated here. For example, the soaking time may be about 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5h. Any range characterized by a combination of the above-mentioned end values ​​is also included, which will not be repeated here. In some embodiments, preferably, in the step 3), the soaking temperature may be 90°C, and the soaking time may be 2h;

[0031] In some embodiments, in the step 3), the immersion is carried out under sealing and stirring conditions. In some embodiments, preferably, in the step 3), magnetic stirring is adopted, and the rotation speed can be 30-70 rpm. For example, the rotation speed can be about 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68 or 70 rpm. It also includes any range characterized by a combination of the above end values, which will not be repeated here. In some embodiments, more preferably, in the step 3), the rotation speed can be 50 rpm.

[0032] In some embodiments, in step 4), a high-pressure homogenizer is used for homogenization.

[0033] In some embodiments, in the step 4), the homogenization pressure can be 50 to 150 bar, the homogenization time can be 4 to 6 minutes, and the number of homogenizations can be 4 to 6 times. For example, the homogenization pressure can be about 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145 or 150 bar. It also includes any range characterized by a combination of the above end values, which will not be repeated here. For example, the homogenization time can be about 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8 or 6 minutes. It also includes any range characterized by a combination of the above end values, which will not be repeated here. In some embodiments, in the step 4), preferably, the homogenization pressure can be 100 bar, the homogenization time can be 5 minutes, and the number of homogenizations can be 5 times.

[0034] In some embodiments, in step 5), the mass ratio of absolute dry tobacco stems to water may be 1:(2-3). In some embodiments, preferably, the mass ratio of absolute dry tobacco stems to water may be 1:2.

[0035] In some embodiments, in the step 5), the extraction temperature may be 65-75°C, and the extraction time may be 25-35 min. For example, the extraction temperature may be about 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 or 75°C. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. For example, the extraction time may be about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 or 35 min. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. In some embodiments, in the step 5), preferably, the extraction temperature may be 70°C, and the extraction time may be 30 min.

[0036] In some embodiments, in step 5), the tobacco stems are rinsed with clean water after filtering the water and before drying.

[0037] In some embodiments, in step 5), the drying temperature may be 105-115°C, and the drying time may be 1.5-2.5h. For example, the drying temperature may be about 105, 106, 107, 108, 109, 110, 111, 112, 113, 114 or 115°C. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. For example, the drying time may be about 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5h. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. In some embodiments, preferably, the drying temperature may be 110°C and the drying time may be 2h.

[0038] In some embodiments, in step 5), a disc refiner can be used for defibration;

[0039] In some embodiments, in step 5), a mill is used for two-stage pulping treatment, and the pulp pressure can be 150-220 kPa, and the frequency can be 35-39 Hz. For example, the pulp pressure can be about 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215 or 220 kPa. It also includes any range characterized by a combination of the above end values, which will not be repeated here. For example, the frequency can be about 35, 36, 37, 38 or 39 Hz. It also includes any range characterized by a combination of the above end values, which will not be repeated here.

[0040] In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 2.5-10% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 3-9.5% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 3.5-9.0% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 4.0-8.5% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 4.5-8.0% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 5.0-7.5% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 5.5-7.0% of the mass of the absolute dry tobacco stem slurry. In some embodiments, in the step 6), the amount of nanocellulose dispersion added is 6.0-6.5% of the mass of the absolute dry tobacco stem slurry.

[0041] In some embodiments, in step 6), preferably, the amount of the nanocellulose dispersion added is 7.5% of the mass of the absolute dry tobacco stem slurry.

[0042] In some embodiments, in step 6), the nanocellulose dispersion is added while stirring at a speed of 25 to 75 rpm. For example, the speed may be about 25, 30, 35, 40, 45, 50, 55, 60, 65, 70 or 75 rpm. Any range characterized by a combination of the above end values ​​is also included, which will not be repeated here. In some embodiments, in step 6), preferably, the speed is 50 rpm.

[0043] The present application also provides the application of the above-mentioned preparation method in enhancing the mechanical properties of reconstituted tobacco leaves and improving the bulk thickness of reconstituted tobacco leaves.

[0044] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are purchased from conventional biochemical reagent companies unless otherwise specified. The quantitative tests in the following examples are repeated three times, and the results are averaged.

[0045] Example 1

[0046] A method for preparing reconstituted tobacco with enhanced mechanical properties and improved bulk by nanocellulose, comprising the following steps:

[0047] 1) The tobacco dust raw material is subjected to delignification treatment, and a food-grade potassium carbonate aqueous solution is used for extraction, the mass concentration of the food-grade potassium carbonate aqueous solution is 7% (75.3 g / L), the liquid ratio is the mass of the absolute dry tobacco dust: the mass of the food-grade potassium carbonate aqueous solution = 1:2, the temperature is 90° C., the time is 20 min, and after the delignification treatment, it is rinsed with clean water to remove lignin, residual drugs and impurities, and the excess water is removed after filtering. Then, it is placed in an oven for drying, the drying temperature is 110° C., and the drying time is 2 h, to obtain the absolute dry delignified tobacco dust;

[0048] 2) uniformly mixing the absolute dry delignified tobacco dust and food grade glycerin, with the mass of the absolute dry delignified tobacco dust: the mass of the food grade glycerin being 1:2, and mechanically extruding twice through a twin-screw oil press to obtain an extruded mixed material;

[0049] 3) adding citric acid to the extruded mixed material and heating and soaking it, wherein the amount of citric acid used is 5% of the mass of the absolutely dry delignified tobacco dust, the soaking temperature is 90° C., the soaking time is 2 h, and sealing and stirring are performed simultaneously during the soaking process, and a magnetic stirring method is used at a rotation speed of 50 rpm to obtain a mixed material;

[0050] 4) transferring the mixed material to a high-pressure homogenizer for homogenization at a processing pressure of 100 bar, a single processing time of 5 min, and a processing number of 5 times to obtain a nanocellulose dispersion;

[0051] 5) The dried tobacco stems are subjected to hot water extraction treatment, the liquid ratio of the hot water extraction is the mass of dried tobacco stems: the mass of water = 1:2, the extraction temperature is 70°C, the extraction time is 30 minutes, and the residue is removed by rinsing with clean water after filtering the water, and then placed in an oven for drying, the drying temperature is 110°C, and the drying time is 2 hours. The dried and extracted tobacco stems are subjected to a disc mill fiberizer for fiberization treatment, and then subjected to a two-stage pulping treatment in a mill, the pulp pressure is 150-220 kPa, and the frequency is 35-39 Hz, to obtain tobacco stem slurry;

[0052] 6) Add the nanocellulose dispersion obtained in 4) to the tobacco stem slurry, the addition ratio is 7.5% of the mass of the absolute dry tobacco stem slurry, stirring while adding the nanocellulose dispersion, the speed is 50 rpm, and after mixing evenly, the reconstituted tobacco leaves are obtained by a sheet making machine, such as Figure 3 (Left) shown.

[0053] The prepared glycerol medium nanocellulose dispersion was sampled and tested, and SEM characterization was performed. The results are as follows Figure 3 (right) Figure 3 (Right) It can be seen that the diameter of nanocellulose is evenly distributed, with a diameter of about 100nm and a length of several microns, and a high aspect ratio. The nanocellulose is evenly dispersed, without flocculation, accumulation, etc., and there are no obvious large impurities.

[0054] Take an appropriate amount of the slurry prepared in step 5) and evenly divide it into slurry 1, slurry 2, slurry 3, slurry 4, slurry 5, slurry 6, slurry 7, slurry 8, and slurry 9. Slurry 1, slurry 2, and slurry 3 are not added with the nanocellulose dispersion prepared in this embodiment, and reconstituted tobacco leaf sheets 1, reconstituted tobacco leaf sheets 2, and reconstituted tobacco leaf sheets 3 are prepared respectively after papermaking; slurry 4, slurry 5, and slurry 6 are added with the nanocellulose dispersion prepared in this embodiment, and the addition ratio is 5% of the absolute dry mass of the slurry, and reconstituted tobacco leaf sheets 4, reconstituted tobacco leaf sheets 5, and reconstituted tobacco leaf sheets 6 are prepared respectively after papermaking; slurry 7, slurry 8, and slurry 9 are added with commercially available wood pulp, and the addition ratio is 5% of the absolute dry mass of the slurry, and reconstituted tobacco leaf sheets 7, reconstituted tobacco leaf sheets 8, and reconstituted tobacco leaf sheets 9 are prepared respectively after papermaking.

[0055] The tensile strength and bulk of reconstituted tobacco leaf slices 1, reconstituted tobacco leaf slices 2, reconstituted tobacco leaf slices 3, reconstituted tobacco leaf slices 4, reconstituted tobacco leaf slices 5, reconstituted tobacco leaf slices 6, reconstituted tobacco leaf slices 7, reconstituted tobacco leaf slices 8 and reconstituted tobacco leaf slices 9 were measured respectively. The measurement results are shown in Tables 1 and 2:

[0056] Table 1

[0057]

[0058] Table 2

[0059]

[0060] As shown in Table 1, the tensile strength of the reconstituted tobacco prepared in this embodiment and added with 7.5% nanocellulose dispersion by absolute dry weight of pulp is significantly better than that of the reconstituted tobacco without adding nanocellulose dispersion, and is equivalent to that of the reconstituted tobacco with 5% commercial wood pulp by absolute dry weight of pulp. As shown in Table 2, the bulk thickness of the reconstituted tobacco prepared in this embodiment and added with nanocellulose dispersion is significantly better than that of the reconstituted tobacco without adding nanocellulose dispersion, and is equivalent to that of the reconstituted tobacco with 5% absolute dry weight of pulp.

[0061] Reconstituted tobacco leaf slices 1, reconstituted tobacco leaf slices 2, reconstituted tobacco leaf slices 3, reconstituted tobacco leaf slices 4, reconstituted tobacco leaf slices 5, reconstituted tobacco leaf slices 6, reconstituted tobacco leaf slices 7, reconstituted tobacco leaf slices 8, and reconstituted tobacco leaf slices 9 were respectively subjected to sensory evaluation of smoking taste. The results of the sensory evaluation of smoking taste showed that the cigarettes prepared from reconstituted tobacco leaf slices 4, reconstituted tobacco leaf slices 5, and reconstituted tobacco leaf slices 6 were superior to the cigarettes prepared from reconstituted tobacco leaf slices 1, reconstituted tobacco leaf slices 2, and reconstituted tobacco leaf slices 3 in terms of smoking taste, woodiness, and other indicators, and were significantly superior to the cigarettes prepared from reconstituted tobacco leaf slices 7, reconstituted tobacco leaf slices 8, and reconstituted tobacco leaf slices 9.

[0062] The reconstituted tobacco prepared in this embodiment is added with the nanocellulose prepared in this embodiment, and the tensile strength and bulk are improved. When preparing reconstituted tobacco, the nanocellulose prepared in this embodiment is added to reduce the use of additional fibers such as wood pulp, reduce woody smell, and improve the taste. Glycerin, as a common tobacco nanocellulose additive, can enhance the aroma components in the smoke, reduce irritation, and improve the taste.

[0063] Example 2

[0064] A method for preparing reconstituted tobacco with enhanced mechanical properties and improved bulk by nanocellulose, comprising the following steps:

[0065] 1) The tobacco dust raw material is subjected to delignification treatment, and a food-grade potassium carbonate aqueous solution is used for extraction, the mass concentration of the food-grade potassium carbonate aqueous solution is 7% (75.3 g / L), the liquid ratio is the mass of the absolute dry tobacco dust: the mass of the food-grade potassium carbonate aqueous solution = 1:2, the temperature is 90° C., the time is 20 min, and after the delignification treatment, it is rinsed with clean water to remove lignin, residual drugs and impurities, and the excess water is removed after filtering. Then, it is placed in an oven for drying, the drying temperature is 110° C., and the drying time is 2 h, to obtain the absolute dry delignified tobacco dust;

[0066] 2) uniformly mixing the absolute dry delignified tobacco dust and food grade glycerin, with the mass of the absolute dry delignified tobacco dust: the mass of the food grade glycerin being 1:2, and mechanically extruding twice through a twin-screw oil press to obtain an extruded mixed material;

[0067] 3) adding citric acid to the extruded mixed material and heating and soaking it, wherein the amount of citric acid used is 3% of the mass of the absolutely dry delignified tobacco dust, the soaking temperature is 90° C., the soaking time is 2.5 h, and sealing and stirring are performed simultaneously during the soaking process, and a magnetic stirring method is used at a rotation speed of 50 rpm to obtain a mixed material;

[0068] 4) transferring the mixed material to a high-pressure homogenizer for homogenization at a processing pressure of 100 bar, a single processing time of 5 min, and a processing number of 5 times to obtain a nanocellulose dispersion;

[0069] 5) The tobacco stem raw material is subjected to hot water extraction treatment, the liquid ratio of hot water extraction is absolute dry tobacco stem mass: water mass = 1:2, the extraction temperature is 70°C, the extraction time is 30min, and the residue is removed by rinsing with clean water after filtering. The tobacco stem is placed in an oven for drying at a drying temperature of 110°C and a drying time of 2h. The dried and extracted tobacco stem is subjected to a disc mill for defibration treatment, and then subjected to a two-stage pulping treatment in a mill, the pulping pressure is 150-220kPa, and the frequency is 35-39Hz, to obtain tobacco stem slurry;

[0070] 6) Add the nanocellulose dispersion obtained in 4) to the tobacco stem slurry, the addition ratio is 5% of the mass of the absolute dry tobacco stem slurry, stirring while adding the nanocellulose dispersion, the speed is 50 rpm, and after mixing evenly, the reconstituted tobacco leaves are obtained by a sheet making machine, such as Figure 4 (Left) shown.

[0071] The prepared glycerol medium nanocellulose dispersion was sampled and tested, and SEM characterization was performed. The results are as follows Figure 4 (right) Figure 4 (Right) It can be seen that the diameter of nanocellulose is evenly distributed, with a diameter of about 100nm and a length of several microns, and a high aspect ratio. The nanocellulose is evenly dispersed, without flocculation, accumulation, etc., and there are no obvious large impurities.

[0072] Take an appropriate amount of the slurry prepared in step 5) and evenly divide it into slurry 10, slurry 11, slurry 12, slurry 13, slurry 14, and slurry 15. Slurry 10, slurry 11, and slurry 12 are not added with the nanocellulose dispersion prepared in this embodiment, and are respectively made into reconstituted tobacco leaf sheets 10, reconstituted tobacco leaf sheets 11, and reconstituted tobacco leaf sheets 12 through papermaking; slurry 13, slurry 14, and slurry 15 are added with the nanocellulose dispersion prepared in this embodiment, and the addition ratio is 5% of the absolute dry mass of the slurry, and are respectively made into reconstituted tobacco leaf sheets 13, reconstituted tobacco leaf sheets 14, and reconstituted tobacco leaf sheets 15 through papermaking.

[0073] The tensile strength and bulk of reconstituted tobacco leaf slices 10, 11, 12, 13, 14 and 15 were measured respectively. The measurement results are shown in Table 3 and Table 4:

[0074] Table 3

[0075]

[0076] Table 4

[0077]

[0078] As shown in Table 3, the tensile strength of the reconstituted tobacco leaves prepared in this embodiment and added with 5% nanocellulose dispersion is significantly better than that of the reconstituted tobacco leaves without the nanocellulose dispersion. As shown in Table 4, the bulk thickness of the reconstituted tobacco leaves prepared in this embodiment and added with nanocellulose dispersion is significantly better than that of the reconstituted tobacco leaves without the nanocellulose dispersion.

[0079] Reconstituted tobacco leaf slices 10, reconstituted tobacco leaf slices 11, reconstituted tobacco leaf slices 12, reconstituted tobacco leaf slices 13, reconstituted tobacco leaf slices 14, and reconstituted tobacco leaf slices 15 were respectively subjected to sensory evaluation of smoking taste. The results of the sensory evaluation of smoking taste showed that the cigarettes prepared from reconstituted tobacco leaf slices 13, reconstituted tobacco leaf slices 14, and reconstituted tobacco leaf slices 15 were superior to the cigarettes prepared from reconstituted tobacco leaf slices 10, reconstituted tobacco leaf slices 11, and reconstituted tobacco leaf slices 12 in terms of smoking taste, woodiness, and other indicators.

[0080] The reconstituted tobacco prepared in this embodiment is added with the nanocellulose prepared in this embodiment, and the tensile strength and bulk are improved. When preparing reconstituted tobacco, the nanocellulose prepared in this embodiment is added to reduce the use of additional fibers such as wood pulp, reduce woody smell, and improve the taste. Glycerin, as a common tobacco nanocellulose additive, can enhance the aroma components in the smoke, reduce irritation, and improve the taste.

[0081] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0082] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

[0083] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0084] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A method for preparing reconstituted tobacco, comprising the following steps: 1) delignifying and drying the tobacco dust to obtain absolutely dry delignified tobacco dust; 2) mixing the absolute dried delignified tobacco dust with glycerin and extruding to obtain a first mixed material; 3) soaking the first mixed material in citric acid to obtain a second mixed material; 4) homogenizing the second mixed material to obtain a nanocellulose dispersion; 5) subjecting the absolutely dried tobacco stems to hot water extraction, water filtering, drying, fiberizing, and pulping to obtain tobacco stem slurry; 6) adding the nanocellulose dispersion into the tobacco stem slurry, mixing, and obtaining reconstituted tobacco leaves through a sheet making machine.

2. The preparation method according to claim 1, characterized in that In the step 1), The tobacco powder was delignified using an aqueous potassium carbonate solution. Preferably, the potassium carbonate is food grade, and more preferably, the concentration of the potassium carbonate aqueous solution is 70 to 80 g / L; And / or, preferably, the absolute dry mass of tobacco dust: the mass of potassium carbonate aqueous solution is 1: (1-3).

3. The preparation method according to claim 1, characterized in that: In the step 1), The treatment temperature of delignification treatment is 85-95°C and the time is 15-25min; and / or, before drying, washing to remove lignin, residual chemicals and impurities, and filtering out excess water; And / or, the drying temperature is 105-115° C. and the drying time is 1.5-2.5 h.

4. The preparation method according to claim 1, characterized in that: In the step 2), Glycerin is food grade glycerin; and / or, the mass ratio of the tobacco dust after absolute dry delignification to the glycerol is 1:(1-2); And / or, mechanical extrusion using an oil press, preferably, mechanical extrusion using a twin-screw oil press; And / or, the number of extrusions is 1 to 3 times.

5. The preparation method according to claim 1, characterized in that: In the step 3), The concentration of citric acid is 90-130 g / L; and / or, the mass ratio of citric acid to absolute dry delignified tobacco dust is 3% to 7%; and / or, the soaking temperature is 80-100° C. and the soaking time is 1.5-2.5 h; And / or, immersing under sealing and stirring conditions, preferably, using magnetic stirring at a rotation speed of 30 to 70 rpm.

6. The preparation method according to claim 1, characterized in that: In the step 4), Use a high pressure homogenizer for homogenization; And / or, the homogenization pressure is 50 to 150 bar, the single homogenization time is 4 to 6 minutes, and the number of homogenization times is 4 to 6 times.

7. The preparation method according to claim 1, characterized in that: In the step 5), The mass ratio of absolutely dry tobacco stems to water is 1:(2-3); and / or, the extraction temperature is 65-75° C., and the extraction time is 25-35 min; And / or, rinse the stems with clean water after draining and before drying.

8. The preparation method according to claim 1, characterized in that: In the step 5), The drying temperature is 105-115°C and the drying time is 1.5-2.5h; and / or, defibration using a disc defibrator; And / or, a mill is used for two-stage pulping treatment, with a pulp pressure of 150 to 220 kPa and a frequency of 35 to 39 Hz.

9. The preparation method according to claim 1, characterized in that: In the step 6), The amount of nanocellulose dispersion added is 2.5-10% of the mass of the absolute dry tobacco stem slurry; and / or, stirring while adding the nanocellulose dispersion at a rotation speed of 25 to 75 rpm.

10. Use of the preparation method according to any one of claims 1 to 9 in enhancing the mechanical properties of reconstituted tobacco leaves and improving the bulk thickness of reconstituted tobacco leaves.

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