HK1189772B - Fragrance-containing sheet and method producing thereof, and smoking article containing same - Google Patents

Description

Flavor-containing sheet, method for producing same, and smoking article comprising same

Technical Field

The present invention relates to a method for producing a sheet containing a flavorant and used for a smoking article, a flavorant-containing sheet for a smoking article produced by the method, and a smoking article comprising the sheet.

Background

When volatile flavor components such as menthol are added to tobacco shreds in the form of a solution, the flavor components dissipate when stored for a long time, and the flavor effect cannot be sustained. To solve this problem, various reports have been made so far.

Patent document 1 and patent document 2 disclose the following methods: the flavoring component is coated with natural polysaccharides and disposed on the filter part of cigarette, thereby inhibiting volatilization and dissipation of the flavoring component, and releasing the flavoring by crushing during smoking. Patent document 3 discloses that a flavor component is coated with a water-soluble matrix such as dextrin and disposed in a filter portion of a cigarette to suppress volatilization and dissipation of the flavor component, and that the water-soluble matrix is dissolved by moisture in mainstream smoke during smoking to release a flavorant. Therefore, when a flavor component is disposed in a filter section, which is a nonflammable section of a cigarette, it is necessary to perform an operation of pressing the filter section during smoking or to release a flavor by dissolving a water-soluble base material with moisture in mainstream smoke, and therefore, there is a time lag until the flavor is tasted.

On the other hand, patent documents 4 to 6 report examples in which a flavor component is disposed in a tobacco shred or a wrapping paper wrapping the tobacco shred as a combustion part.

Patent document 4 discloses a method of applying a flavor material obtained by incorporating a flavor component into the inside of a three-dimensional network structure of glucan molecules to wrapping paper of a filler for wrapped tobacco. The cigarette of patent document 4 has a good flavor retention property because the flavor component is fixed and retained in the three-dimensional network structure of the glucan molecule. However, since the flavor component is present in a small amount (20% by weight or less) in the glucan molecule, when a large amount of flavor component such as menthol is required, the amount of flavor material added to the cigarette increases.

Patent document 5 discloses the following method: a granular gel was prepared by mixing and dropwise adding a liquid flavor and a carrageenan sol to an ionic solution (a solution containing potassium ions), and dried in air, thereby preparing "a stabilized aromatic substance stable up to 180 ℃. However, in the method of patent document 5, since the granular gel is dried in the air, a long time and a large facility are required for preparing a large amount of raw materials. In this method, metal ions (gelation accelerator) are added to carry out gelation.

Patent document 6 reports the following method: drying a slurry containing a flavor component such as menthol and a polysaccharide to prepare a sheet in which the flavor component is coated with a polysaccharide gel, cutting the sheet, and adding the cut sheet to tobacco shreds. In this report, drying of the slurry requires a period of 1 week at 40 ℃.

Documents of the prior art

Patent document

Patent document 1 Japanese patent laid-open publication No. Sho 64-27461

Patent document 2 Japanese patent application laid-open No. 4-75578

Patent document 3 pamphlet of International publication No. 2009/157240

Patent document 4, Japanese patent laid-open No. 9-28366

Patent document 5 Japanese patent application laid-open No. Hei 11-509566

Patent document 6 pamphlet of International publication No. 2009/142159

Disclosure of Invention

Problems to be solved by the invention

The present inventors have attempted to simply increase the drying temperature in order to produce a menthol-containing sheet in a short time as a flavor-containing material used in smoking articles, particularly cigarettes, and as a result, have encountered the following problems: the obtained sheet has low menthol content and low preparation yield, and the menthol content is reduced after the sheet is stored.

Accordingly, an object of the present invention is to provide a method for producing a fragrance-containing sheet material for a smoking article, which has a large content of a fragrance material, a high production yield of the fragrance material, and a high storability when incorporated into a smoking article, in a short time, and a fragrance-containing sheet material for a smoking article, which has a high storability when incorporated into a smoking article, and can be produced in a short time.

Means for solving the problems

The present inventors have conducted studies to solve the problem and, as a result, have found that: even when a high-temperature drying temperature is used, at which drying of a sheet containing a perfume can be achieved in a short time, if the sheet is cooled and dried before heat drying (preferably, initial drying at a high temperature and post-drying at a lower temperature than the initial drying), a sheet having a high perfume content and a high perfume production yield can be produced, and the sheet can maintain a high perfume content even after storage, and the present invention has been completed.

That is, according to one aspect of the present invention, there is provided a method for producing a flavor-containing sheet for use in a smoking article, comprising the steps of: spreading a raw material slurry in a sol state at 60 to 90 ℃ on a base material, the raw material slurry containing polysaccharides and perfume and having a water content of 70 to 95 wt%; a step of cooling the spread raw material slurry to a sample temperature of 0 to 40 ℃ to cause gelation; and a heating and drying step which comprises heating the gelled raw material and drying the heated gelled raw material at a sample temperature of 70 to 100 ℃.

According to a preferred embodiment, the heat drying step is carried out so that the sample temperature is 100 ℃ or lower throughout the entire period of the step.

According to a preferred embodiment, the heat drying step is a step of heating the raw material to a sheet form having a moisture content of less than 10% for a total heat drying time of 20 minutes or less.

According to a preferred embodiment, the heat drying step is a step of: the gelled raw material is dried in a sheet form having a moisture content of less than 10% for a total heating and drying time of 20 minutes or less by initially drying the raw material by blowing hot air at a temperature of 100 ℃ or more for a time of 1/4 or more of the total heating and drying time, and then by blowing hot air at a temperature of less than 100 ℃ for a time of 1/4 or more of the total heating and drying time, and by performing post-drying.

Further, according to other aspects of the present invention, there may be provided a fragrance-containing sheet for a smoking article, characterized in that the fragrance-containing sheet for a smoking article is manufactured by the method.

Further, according to another aspect of the present invention, there is provided a smoking article comprising a cut tobacco into which the flavor-containing sheet for a smoking article is blended.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the method for producing a flavor-containing sheet for a smoking article of the present invention, a flavor-containing sheet for a smoking article having a high flavor content, a high flavor production yield, and a high flavor retention when incorporated in a smoking article can be produced in a short time. The flavor-containing sheet material for a smoking article of the present invention has high storability when incorporated in a cigarette, and can be produced in a short time.

Drawings

Fig. 1 is a graph showing the menthol content of a menthol-containing sheet after storage.

FIG. 2A is a graph showing the change in viscosity with a decrease in temperature of an aqueous gellan gum solution.

FIG. 2B is a graph showing the change in viscosity with an increase in temperature of the gellan gum aqueous solution.

Fig. 3A is a graph showing the temperature of the sample No. 1 during the heat drying step.

Fig. 3B is a graph showing the temperature of the sample No. 2 during the heat drying step.

Fig. 3C is a graph showing the temperature of the sample No. 3 during the heat drying step.

Fig. 3D is a graph showing the temperature of the sample No. 4 during the heat drying step.

Fig. 3E is a graph showing the temperature of the sample No. 5 during the heat-drying step.

Fig. 3F is a graph showing the temperature of the sample No. 6 during the heat-drying step.

Fig. 3G is a graph showing the temperature of the sample No. 7 during the heat drying step.

Fig. 4A is a graph showing the effect of cooling on the menthol content of a menthol-containing sheet (comparative example) after storage.

Fig. 4B is a graph showing the effect of cooling on the menthol content of a menthol-containing sheet (example of the present invention) after storage.

Fig. 5 is a graph showing the relationship between the cooling temperature and the menthol content of the menthol-containing sheet.

Fig. 6 is a graph showing the relationship between the moisture content of the menthol-containing sheet and the menthol fragrance retention rate.

Detailed Description

The present invention will be described below, but the purpose of the following description is to explain the present invention in detail and not to limit the present invention.

As the flavorant contained in the flavorant-containing sheet of the present invention, any flavorant may be used without limitation as long as it is a flavorant used in a smoking article. Examples of the main perfume include: menthol, tobacco extract, natural plant perfume (e.g., cinnamon, sage, vanilla, chamomile, kudzu, feverfew, clove, lavender, cardamom, clove (チョウジ), nutmeg, bergamot, geranium, honey essence, rose oil, lemon, orange, cinnamon, caraway, jasmine, ginger, coriander, vanilla extract, spearmint, mint, cinnamon, coffee, celery, caraway, sandalwood, cocoa, ylang, fennel, anise, licorice, carob pod, plum extract, peach extract, etc.), saccharides (e.g., glucose, fructose, isomerized sugar, caramel, etc.), cocoa (powder, extract, etc.), esters (e.g., isoamyl acetate, linalyl acetate, isoamyl propionate, linalyl butyrate, etc.), ketones (e.g., menthone, ionone, damascenone, ethyl maltitol, etc.), (e.g., menthol, rosemary, clove, lavender, caraway, clove, cardamomum, clove oil, alcohols (e.g., geraniol, linalool, anethole, eugenol, etc.), aldehydes (e.g., vanillin, benzaldehyde, anisic aldehyde, etc.), lactones (e.g., γ -undecalactone, γ -nonalactone, etc.), animal perfumes (e.g., musk, ambergris, civet, castoreum, etc.), hydrocarbons (e.g., limonene, pinene, etc.). It is preferable to use a perfume which is easily dispersed in a solvent by adding an emulsifier, for example, a hydrophobic perfume, an oil-soluble perfume, and the like. These perfumes may be used alone or in combination.

Hereinafter, the present invention will be described by taking a case of using menthol as a flavor as an example.

1. Menthol-containing sheet material for smoking articles

In one embodiment of the present invention, a menthol-containing sheet for a smoking article (hereinafter referred to as a menthol-containing sheet) is produced by a method including the steps of: spreading a raw material slurry in a sol state at 60 to 90 ℃ on a base material, the raw material slurry containing polysaccharides and perfume and having a water content of 70 to 95 wt%; a step of cooling the spread raw material slurry to a sample temperature of 0 to 40 ℃ to cause gelation; and a heating and drying step which comprises heating the gelled raw material and drying the heated gelled raw material at a sample temperature of 70 to 100 ℃.

In the present specification, "sample temperature" refers to the surface temperature of a sample (i.e., slurry or sheet).

According to a preferred embodiment, the heating and drying step is a step of: the gelled raw material is dried in a sheet form having a moisture content of less than 10% for a total heating and drying time of 20 minutes or less by initially drying the raw material by blowing hot air at a temperature of 100 ℃ or more for a time of 1/4 or more of the total heating and drying time, and then by blowing hot air at a temperature of less than 100 ℃ for a time of 1/4 or more of the total heating and drying time, and by performing post-drying.

(1) Preparation of raw slurry

In the present invention, the raw material slurry can be prepared by a method comprising the following steps: (i) mixing and heating a polysaccharide with water to prepare an aqueous solution of the polysaccharide; (ii) adding menthol and an emulsifier to the aqueous solution, and kneading and emulsifying the mixture.

The step (i) may be specifically performed as follows: the polysaccharide was added to water in small amounts at a time, and dissolved with stirring. The heating temperature in this case may be 60 to 90 ℃, preferably 75 to 85 ℃. The step (ii) can be carried out by a known emulsification technique using a homogenizer because the raw material slurry has a viscosity of about 10,000mPas (in a sol state) at the above heating temperature, which does not interfere with emulsification.

The raw material slurry may be, for example, 200 to 500g of polysaccharides, 1000 to 2500g of menthol, and 80 to 200ml of 2 to 10 wt% emulsifier solution, based on 10L of water. The moisture content of the raw material slurry is 70 to 95 wt%, preferably 80 to 90 wt%. The ratio (weight ratio) of the polysaccharides and the menthol in the raw material slurry may be set to 1: 1-1: 10.

in the present invention, the polysaccharide has a property of gelling when it is temporarily cooled after heating, and fixing and coating the micelle (micell) of menthol. The polysaccharide is preferably a natural thickening polysaccharide, such as a one-component system of carrageenan, agar, or gellan gum; or a composite system comprising 1 or more ingredients selected from locust bean gum, guar gum, tamarind gum, xanthan gum, tara gum, konjac glucomannan, cassia gum and plantain seed gum, and carrageenan, agar or gellan gum.

In the present invention, l-menthol can be used as menthol.

As the emulsifier in the present invention, a natural emulsifier such as lecithin, specifically SunLecithinA-1 (available from Sun chemical Co., Ltd.) can be used.

(2) Spreading of the raw material slurry on the base material

The raw material slurry of 60 to 90 ℃ prepared as described above is spread on a base material.

The spreading of the raw material slurry can be performed by the following method: the raw material slurry was extruded on the base material through a slit die using a casting nozzle (castinggate). As the base material, any substrate from which a menthol-containing sheet produced by drying and molding can be peeled can be used, and for example, a polyethylene terephthalate (PET) film (FE 2001, Futamura chemical) can be used. The raw material slurry may be spread so that the thickness of the raw material slurry when dried is about 0.1mm, which is the same thickness as that of ordinary cut tobacco.

(3) Cooling of the slurry before drying and shaping

In the preparation of the menthol-containing sheet of the present invention, the spread raw material slurry is temporarily cooled before drying at a temperature (0 ℃ or higher), that is, 0 to 40 ℃, preferably 0 to 30 ℃, and more preferably 15 to 25 ℃, at which the slurry is sufficiently gelled (40 ℃ or lower) and the emulsion is not generally frozen and broken. Here, the raw material slurry before cooling has a temperature of 60 to 90 ℃, preferably 75 to 85 ℃, and is in a sol state. This pre-cooling may be performed by blowing cold air (e.g., 10 ℃) generated only by an air blow or a local cooler (e.g., Sudden SS-25 DD-1) to the spread raw material slurry for 2 to 3 minutes. Alternatively, the pre-cooling may be performed by contacting the spread raw material slurry with a pipe through which a condensing medium (e.g., 10 ℃) generated by a cold and hot water generator (cooler, for example, ApistePCU-1600R) flows for 1 to 2 minutes. Alternatively, the pre-cooling may be performed by leaving the spread raw material slurry at room temperature.

As shown in example 4 described later, the aqueous solution of polysaccharides exemplified above, when once cooled and gelled, is less likely to gel even when the temperature is increased thereafter and the temperature is changed to a gel, and has a property of maintaining the gelled state. In the present invention, when the raw material slurry is precooled before being dried by utilizing such a property, the polysaccharide contained in the precooled raw material slurry is less likely to be gelated even if the temperature is increased during drying, and the menthol coated with the polysaccharide is less likely to be volatilized, which is confirmed in the present invention.

In addition, the following advantages are provided: when the raw material slurry is spread on a base material and temporarily cooled, the spread raw material slurry is less likely to be deformed (collapsed) even if exposed to a high temperature in a subsequent drying step.

The effect of this cooling on the storability of the fragrance-containing sheet is demonstrated in example 6 (fig. 4B) described later, and a lower cooling temperature is associated with a greater menthol content, which is demonstrated in example 7 (fig. 5) described later.

(4) Drying and shaping of the slurry

The raw material slurry spread and cooled can be heated and dried by any heating and drying method such as hot air drying and infrared heating and drying. Hereinafter, "heat drying" of the raw material slurry is also simply referred to as "drying".

The drying of the raw material slurry in the invention comprises the following steps: the cooled raw material slurry is heated and dried at a sample temperature of 70 to 100 ℃, preferably at a sample temperature of 100 ℃ or less in the total drying time.

Here, "sample temperature" refers to the surface temperature of a sample (i.e., slurry or sheet). Further, "total drying time" refers to the time of heating in the heating dryer. The total drying time is generally 20 minutes or less, preferably 7 to 20 minutes, and more preferably 10 to 18 minutes.

In the present invention, the sample temperature may be lower than 70 ℃ during the drying process, but in order to shorten the drying time, it is preferable that the period in which the sample temperature is lower than 70 ℃ is short. In the present invention, the sample temperature may exceed 100 ℃ during the drying step, but in order to stably retain the perfume, it is preferable that the period in which the sample temperature exceeds 100 ℃ is short. Therefore, in the drying of the raw material slurry, the cooled raw material slurry is preferably dried at a sample temperature of 70 to 100 ℃ over a time period of 1/2 or more of the total drying time, and the sample temperature is preferably 100 ℃ or less in the total drying time. More preferably, the cooled raw material slurry is dried at a sample temperature of 70 to 100 ℃ over the entire drying time, whereby the raw material slurry can be dried.

However, since the temperature of the sample in the heat dryer is increased from the pre-cooling temperature to the desired sample temperature (70 ℃) immediately after the start of the heat drying and the temperature of the sample does not reach the desired sample temperature, the "total drying time" expressed as "the sample temperature of 70 to 100 ℃ over the entire total drying time" means: the total drying time during the onset of the increase in sample temperature to the desired sample temperature is not included. For example, in example 5 (fig. 3A to 3G) described later, since the sample temperature rises to the desired sample temperature in a period of about 1 minute from the start of the heat drying, "total drying time" expressed as "sample temperature of 70 to 100 ℃ over the entire total drying time" does not include the start period.

The raw material slurry is preferably dried in a sheet form having a moisture content of less than 10% for a total drying time of 20 minutes or less, whereby the raw material slurry can be dried.

When the raw material slurry is dried at the above-mentioned sample temperature, the sheet obtained by drying can realize high storability, which is confirmed in example 5 (fig. 3D to 3G) described later.

Hereinafter, the hot air drying will be described. In the case of hot air drying, in order to maintain a sample temperature of 70 to 100 ℃, it is preferable to perform hot air drying at a temperature of 100 ℃ or higher at the time of first drying of the raw material slurry and then dry the slurry at the same temperature as or lower than the first hot air temperature (preferably 70 ℃ or higher and lower than 100 ℃). Thus, the rise of the sample temperature in the latter stage of drying can be suppressed, and the sample temperature can be kept at not more than 100 ℃ for the entire total drying time, for example.

In the present invention, by temporarily cooling the prepared raw material slurry, even if a drying operation (for example, high-temperature drying with hot air of 100 ℃ or higher) is included during the subsequent drying step, such that the sample temperature is 70 to 100 ℃, the menthol content of the produced menthol-containing sheet becomes large, the production yield of menthol is high, and the menthol content can be maintained at a high value even after storage.

In the case of hot air drying, the hot air temperature may be a constant temperature throughout the drying process, or may be changed during the drying process. When the hot air temperature is changed, the raw material slurry is preferably dried by an initial drying at a high temperature using hot air of 100 ℃ or higher and a subsequent post-drying at a low temperature using hot air of less than 100 ℃. In the present specification, "initial drying" refers to the first drying in a drying step using hot air having a high temperature of 100 ℃ or higher, and "post-drying" refers to the subsequent drying in the initial drying step using hot air having a low temperature of less than 100 ℃. As described above, if the initial drying with hot air at a high temperature and the post-drying with hot air at a low temperature are combined, there is an advantage that the sample temperature does not become excessively high. In the case of hot air drying, the temperature in the dryer is the same as the hot air temperature.

Further preferably, the drying of the raw material slurry may be performed by: the raw material slurry is dried to a sheet form having a moisture content of less than 10% in a total drying time of 20 minutes or less by performing initial drying at a hot air temperature of 100 ℃ or more for a time of 1/4 or more of the total drying time and then performing post-drying at a hot air temperature of less than 100 ℃ for a time of 1/4 or more of the total drying time.

By combining the initial drying with hot air at a high temperature and the post-drying with hot air at a low temperature as described above, the rise of the sample temperature during the post-drying can be suppressed, and the sample temperature can be maintained at not more than 100 ℃. Thus, the menthol-containing sheet of the present invention has a high menthol content after production, and can maintain the menthol content at a high value even after storage (see sample No. 4 of example 1, sample No. 5 of example 2, and sample No. 6 of example 3, which will be described later).

When the raw material slurry is dried by hot air drying, the initial drying may be performed at a hot air temperature of 100 ℃ or higher and 130 ℃ or lower for 4 to 6 minutes, and the post-drying may be performed at a hot air temperature of 70 ℃ or higher and lower than 100 ℃ for 4 to 6 minutes, for example. The amount of hot air can be set to 3 to 20 m/sec, for example. The total drying time is generally 20 minutes or less, preferably 7 to 20 minutes, and more preferably 10 to 18 minutes.

The conditions (temperature, time, and air volume) of the initial drying and the final drying can be appropriately set within the above ranges, for example. For example, the surface of the raw material slurry is evaporated, and the slurry is initially dried at a hot air temperature of 100 ℃ or higher and 130 ℃ or lower until a sufficient film is formed on the surface of the slurry, and then is rapidly switched to a hot air temperature of 70 ℃ or higher and lower than 100 ℃ to perform the post-drying.

The temperature of the hot air during the initial drying period may be constant or may be changed to decrease in order between 100 ℃ and 130 ℃. In addition, the temperature of the hot air during the post-drying may be constant or may be changed to be lower than 70 ℃ and lower than 100 ℃. For example, a hot air dryer used in the later-described examples has 3 drying chambers, and the sample is conveyed by a conveyor belt in the order of chamber 1 → chamber 2 → chamber 3, so that initial drying (100 ℃ or higher) can be performed at the same temperature or at different temperatures using chamber 1 and chamber 2, and post-drying (less than 100 ℃) can be performed using chamber 3; the initial drying (100 ℃ C. or higher) may be performed in the 1 st chamber, and the post-drying (less than 100 ℃ C.) may be performed in the 2 nd and 3 rd chambers at the same or different temperatures.

In the present invention, the drying is performed in a state where the menthol-containing sheet is sufficiently dried, and the drying is performed until the menthol-containing sheet can be easily peeled from the base material and the menthol-containing sheet can be cut in the subsequent cutting step. Specifically, the sheet containing menthol is dried until the moisture content is less than 10% by weight, preferably 3 to 9% by weight, and more preferably 3 to 6% by weight (see example 8 described later). The moisture content is a value measured by a measurement method described in examples described later.

The menthol content of the menthol-containing sheet of the present invention (immediately after production) is preferably 45% by weight or more, and more preferably 55 to 75% by weight. The menthol content of the menthol-containing sheet of the present invention after storage (at 50 ℃ for 30 days) is preferably 45% by weight or more, and more preferably 48 to 63% by weight. The menthol content herein refers to a value measured by a measurement method described in examples described later.

2. Smoking article

The menthol-containing sheet of the present invention can be cut into a size equivalent to that of ordinary cut tobacco, for example, and incorporated into cut tobacco of a smoking article. The cut matter of the sheet containing menthol may be blended in an amount of 2 to 10g relative to 100g of the cut tobacco. The cut material of the menthol-containing sheet is preferably dispersed and blended in the cut tobacco.

The menthol-containing sheet of the present invention can be incorporated into any smoking article, for example, a combustion type smoking article in which tobacco leaves are combusted to taste tobacco flavor, particularly, tobacco shreds of cigarettes. In particular, the menthol-containing sheet of the present invention can be incorporated into tobacco shreds of a cigarette provided with a tobacco rod containing tobacco shreds and cigarette wrapping paper wrapped around the tobacco shreds.

Examples

[ example 1]

(1) Preparation of stock slurry (10L Scale)

10L of water

Gellan gum (Kelcogel/Sanrongyuan F.F.I) 150g

Tamarind gum (VisTopD-2032/Sanrongyuan F. I) 150g

Lecithin (Sun Lecithin A-1/Sun chemical Co., Ltd.) 120mL (5% aqueous solution)

Menthol (high sand flavor industry Co., Ltd.) 1500g

While stirring with a MIXER (PRIMIX T.K. AUTO MIXER Model 40/mounting solution stirrer/2000 rpm) while maintaining water (10L) at 80 ℃ gellan gum (150 g) and tamarind gum (150 g) were dissolved in small portions without caking (required time about 20 minutes) and menthol (1500 g) was added.

The mixture was emulsified by replacing the stirrer with a homogenizer (PRIMIX T. K. AUTO MIXER Model 40/rotor head mounted/4000 rpm) for 10 minutes, and lecithin (120 mL (5% aqueous solution)) was added thereto to continue the emulsification for 10 minutes, thereby obtaining a raw material slurry.

(2) Drying and shaping

The obtained raw material slurry was extruded on a base material film by a slit die, and then, the raw material slurry was cooled to about 20 ℃ by blowing with cold air (10 ℃) generated by a local cooler (Suiden SS-25 DD-1) for 2 to 3 minutes, and then, hot air-dried by carrying out belt conveyance in a hot air dryer, thereby obtaining a film-like menthol-containing sheet. Details of the experiment are shown below.

And (3) slit die: vertical slit die (60 ℃ heating and heat preservation), thickness of 900 μm and width of 20cm

Base material film: PET film (surface Corona treatment) thickness 50 μm

A hot air dryer: hot air type drying and forming machine having the following structure

Drying and partitioning: 3 chambers (each zone length 2.5m, total length 7.5 m)

Hot air volume and form: a 1 st chamber: perforated plate, air quantity 5 m/s

: and a 2 nd chamber: perforated plate, air flow 10 m/s

: and a 3 rd chamber: floating jet, air quantity 20 m/s

In the 1 st and 2 nd chambers, hot air is blown to the menthol-containing sheet conveyed on the conveyor belt through perforated plates having holes and functioning as flow control plates. In the 3 rd chamber, hot air is blown by ventilation from the top and bottom direction to the menthol-containing sheet floating and conveyed together with the base material film.

Menthol-containing sheets of sample numbers 1 to 4 were prepared by changing the hot air drying conditions as described in table 1 below. The temperature is the temperature of hot air. The drying time is set so that the menthol-containing sheet is sufficiently dried and can be easily peeled from the base material film, and the menthol-containing sheet can be cut in a subsequent cutting process. The moisture content of the menthol-containing sheet obtained in this example was about 3%.

(3) Measurement of drying Condition of menthol-containing sheet

The moisture content of the menthol-containing sheet was measured by GC-TCD as described below.

First, 0.1g of a menthol-containing sheet (cut to 1X 10mm) was weighed, placed in a 50 mL-volume closed container (screw tube), 10mL of methanol (extra grade reagent or equal to or more than that, and a new product was dispensed so as not to be exposed to the atmosphere in order to exclude the influence of moisture absorption in the air) was added, and shaking (200rpm) was performed for 40 minutes. After standing overnight, shaking was carried out again for 40 minutes (200rpm), and the supernatant after standing (which was not diluted for GC measurement) was used as a measurement solution.

The measurement solution was quantified by a standard curve method based on the following GC-TCD.

GC-TCD: 6890 gas chromatograph manufactured by Hewlett Packard Co

Column: HP Polapack Q (packed column) fixed flow Rate mode 20.0mL/min

Sample introduction amount: 1.0 μ L

Feeding port: EPC flushing packed column feed port heater; 230 deg.C

Gas: total flow rate of He: 21.1mL/min

Oven: 160 ℃ (hold for 4.5 minutes) → (60 ℃/min) → 220 ℃ (hold for 4.0 minutes)

A detector: TCD detector standard gas (He) flow: 20mL/min

Make-up gas (He)3.0mL/min

Signal frequency: 5Hz

Standard curve solution concentration: 0.1, 3, 5, 10, 20[ mg-H2O/10mL ].

(4) Determination of menthol content of menthol-containing sheet

The menthol content of the menthol-containing sheet was measured by GC-FID as described below.

First, 0.1g of a menthol-containing sheet (cut to 1X 10mm) was weighed, placed in a 50 mL-volume closed container (screw tube), 10mL of methanol (extra grade reagent or equal to or more than that, and a new product was dispensed so as not to be exposed to the atmosphere in order to exclude the influence of moisture absorption in the air) was added, and shaking (200rpm) was performed for 40 minutes. After standing overnight, shaking was carried out again for 40 minutes (200rpm), and the supernatant after standing (here, diluted with × 10 methanol for GC measurement) was used as a measurement solution.

The measurement solution was quantified by the standard curve method based on the following GC-FID.

GC-FID: 6890N gas chromatograph manufactured by Agilent

Column: DB-WAX30m X530 μm X1 μm

Constant pressure mode 5.5psi (speed; 50cm/sec)

And (3) injection: 1.0 μ L

Feeding port: no-split mode 250 ℃ 5.5psi

Oven: 80 ℃→ (10 ℃/min) → 170 ℃ (hold 6.0 minutes) [ max 220 ℃ ]

A detector: FID Detector 250 deg.C (H2: 40mL/min, air: 450mL/min)

Signal frequency: 20Hz

Standard curve solution concentration: 0. 0.01, 0.05, 0.1, 0.3, 0.5, 0.7, 1.0[ mg-menthol/mL ], 8 points.

The menthol content (mg) of the prepared menthol-containing sheet and the menthol content (mg) of the menthol-containing sheet after storage in an accelerated environment were measured, and are shown in table 1 as "initial menthol content (%)" and "menthol content (%) after storage".

Initial menthol content (%) { measured value of menthol content (mg)/weight of menthol-containing sheet (mg) } × 100

Menthol content (%) after storage { (measured value of menthol content (mg)/weight of menthol-containing sheet (mg) } × 100

The acceleration environment is as follows.

A sheet containing menthol (cut to about 1X 10mm and 5g) was placed in an open container and stored in a thermostat (Drying Oven DX600, Yamato science) set at 50 ℃ for 30 days at the maximum.

The menthol fragrance retention rate was calculated from the value of the menthol content by the following formula and the fragrance retention function of the menthol-containing sheet was evaluated.

Menthol fragrance retention rate (%) { (menthol content after storage)/(initial menthol content) } × 100

(5) Results

Menthol-containing sheets of sample numbers 1 to 4 were produced by the hot air drying molding machine described above under the hot air drying conditions shown in table 1. The moisture content and initial menthol content of the menthol-containing sheet were measured by the above-described methods, and the results are shown in table 1. The menthol content after 30 days of storage is shown in table 1, and the menthol content after 7 days, 14 days, and 30 days of storage is shown in fig. 1. In FIG. 1, reference numerals 1 to 7 denote sample numbers 1 to 7.

[ Table 1]

Sample No. 1

When the raw material slurry is spread and dried by the hot air type drying and forming machine to be formed into a sheet shape, the following method is often employed: since no surface coating was formed during the first half of the drying, the drying was started from a low hot air temperature (about 70 ℃) and was carried out at a high hot air temperature (about 120 ℃) for complete drying during the second half of the drying. According to this method, when the menthol-containing sheet of sample No. 1 was prepared, a sufficiently dried sample (moisture content 3.1%) was prepared within 12 minutes of the total drying time. The "initial menthol content" after the sheet was prepared was 81.5%, which was very high, but the "menthol content after storage" after storage in an accelerated environment (20 days) was as low as 13.6%, which caused a problem in the aroma retention property when stored in the sheet of sample No. 1.

Sample No. 2

Sample No. 2 was dried at a high temperature because it took a shorter drying time than sample No. 1. Thus, sample No. 2 produced a sufficiently dried sample (moisture content 3.2%) within 6 minutes of the total drying time. The "initial menthol content" after the sheet was prepared was 62.4%, which was very high, but the "menthol content after storage" after storage in an accelerated environment (30 days) was as low as 29.2%, which caused a problem in the aroma retention property when stored in the sheet of sample No. 2.

Sample No. 3

In sample No. 3, the hot air temperature was set to 70 ℃ throughout the drying step. Thus, sample No. 3 produced a sufficiently dried sample (moisture content 3.1%) within 60 minutes of the total drying time. The "initial menthol content" after the sheet was prepared was 75.8%, which was very high, and the "menthol content after storage" after storage (30 days) in an accelerated environment was as high as 59.2%, which resulted in good fragrance retention after the sheet was prepared and good fragrance retention after storage. However, the time required for drying is as long as 60 minutes.

Sample No. 4

In contrast to sample nos. 1 and 2, which were shifted from low-temperature drying to high-temperature drying, sample No. 4 was subjected to initial drying with hot air at a high temperature (120 ℃) (chambers No. 1 and 2) and to post-drying with hot air at a low temperature (70 ℃) (chamber No. 3). Sample No. 4a sample was prepared which had a total drying time as short as 7.5 minutes, but was sufficiently dried (moisture content 3.4%). The "initial menthol content" after the sheet was prepared was 75.7% and very high, and the "menthol content after storage" after storage (30 days) in an accelerated environment was as high as 62.4%, and therefore, both the fragrance retention property after the sheet was prepared and the fragrance retention property after storage were good. As described above, if the initial drying at a high temperature and the post-drying at a low temperature are employed, a sheet having excellent aroma retention can be produced in a shorter drying time.

[ example 2]

A menthol-containing sheet of sample No. 5 was produced in the same manner as in example 1 except that the slurry was dried under the hot air drying conditions shown in table 2 below, and the moisture content and the menthol content were measured. The results are shown in Table 2.

[ Table 2]

The sample number 5 increases the amount of hot air compared with the sample numbers 1 to 4. In the 1 st chamber, hot air is blown from the up-down direction by ventilation to the menthol-containing sheet floating and being conveyed. In the 2 nd and 3 rd chambers, hot air is blown to the menthol-containing sheet conveyed on the conveyor belt by ventilation.

Sample No. 5 was initially dried with hot air at a high temperature (120 ℃ C.) for 4 minutes (chamber 1), and then later dried with hot air at a low temperature (70 ℃ C.) for 8 minutes (chambers 2 and 3). Sample No. 5 a sample (moisture content 3.1%) which was sufficiently dried within 12 minutes of the total drying time was prepared. The "initial menthol content" after the sheet was prepared was 72.7%, which was very high, and the "menthol content after storage" after storage (30 days) in an accelerated environment was also as high as 58.5%, which resulted in good fragrance retention after the sheet was prepared and fragrance retention after storage. As described above, if the initial drying at a high temperature and the post-drying at a low temperature are employed, a sheet having excellent aroma retention can be produced in a shorter drying time.

[ example 3]

Menthol-containing sheets of sample numbers 6 and 7 were prepared in the same manner as in example 1, except that the slurry was dried under the hot air drying conditions described in table 3 below using a hot air type dryer having a drying section of 4 chambers, and the moisture content and the menthol content were measured. The results are shown in Table 3.

[ Table 3]

Sample nos. 6 and 7 produced menthol-containing sheets using a hot air type drying and molding machine having a drying section of 4 chambers.

Sample No. 6 was initially dried with hot air at a high temperature (110 ℃→ 100 ℃) for 6.6 minutes (first chamber 1 to 3), and then later dried with hot air at a low temperature (80 ℃) for 2.2 minutes (second chamber 4). Sample No. 6 a sample (moisture content 5%) which was sufficiently dried within 8.8 minutes of the total drying time was prepared. The "initial menthol content" after the sheet was prepared was 63.5%, which was very high, and the "menthol content after storage" after storage (30 days) in an accelerated environment was as high as 59.9%, which resulted in good fragrance retention after the sheet was prepared and good fragrance retention after storage. Thus, even if the temperature of hot air during the initial drying is changed in such a manner that the temperature of hot air is sequentially lowered from 110 ℃ to 100 ℃, by employing the initial drying at a high temperature and the post-drying at a low temperature, a sheet having excellent aroma retention can be produced in a shorter time.

The sample No. 7 was dried with hot air at 100 ℃ in both the initial stage and the final stage. Sample No. 7 did not adopt the post-drying at low temperature, but it is assumed that the sample temperature did not become too high due to the presence of moisture in the sample in the process of drying the slurry, as in sample nos. 4 to 6. That is, sample No. 7 produced a sufficiently dried sample (moisture content: 4.9%) within 8.8 minutes of the total drying time. The "initial menthol content" after the sheet was prepared was 61.9%, which was very high, and the "menthol content after storage" after storage (30 days) in an accelerated environment was also as high as 60.8%, which resulted in good fragrance retention after the sheet was prepared and fragrance retention after storage. Thus, even when the same hot air temperature of 100 ℃ was used throughout the drying process, a sheet having excellent aroma-retaining properties could be produced in a shorter drying time as in sample nos. 4 to 6.

[ example 4]

In this example, the temperature-sensitive sol-gel transition characteristics of an aqueous polysaccharide solution (slurry) were examined.

0.1L of water

Gellan gum (Kelcogel/Sanrongyuan F.F.I) 5g

While stirring, gellan gum (5g) was dissolved in small portions in water (0.1L) at 70 ℃ in an Atec Japan high performance mixer DMM so as not to coagulate, to prepare an aqueous polysaccharide solution (slurry).

The slurry (70 ℃ C.) was cooled to 25 ℃ over about 900 seconds (0.05 ℃ C./second). Then, the temperature was raised to 70 ℃ over about 900 seconds. Fig. 2A and 2B show how the viscosity (fluidity) of the slurry changes due to such a temperature change.

As shown in fig. 2A, when the slurry is cooled (chilled) to 25 ℃, the viscosity is low (fluidity is high) until 50 ℃, but the viscosity rises sharply (gelation phenomenon) at 40 ℃ or lower. When the temperature of the gel is raised, the gel is not easily restored to the sol even if the temperature exceeds the gelation temperature (40 ℃) and the gel state can be maintained at a very high temperature as shown in fig. 2B.

From these results, it was found that when the polysaccharide-containing slurry was once cooled to gel, the slurry was not easily restored to a sol even when the temperature was increased thereafter, and the gel state was maintained. In the present invention, when the raw material slurry is precooled before drying by utilizing the properties of the polysaccharides, it is expected that the polysaccharides contained in the precooled raw material slurry are not easily gelatinized even when the temperature is increased during drying, and that the menthol coated with the polysaccharides is not easily volatilized.

[ example 5]

In this example, sheets of sample numbers 1 to 7 were prepared as described in examples 1 to 3, and the temperature of the sample during the drying step was measured. The hot air drying conditions for the samples of sample numbers 1 to 7 can be referred to tables 1 to 3.

The sample temperature can be measured by directly measuring the sample (slurry) during the drying step using a non-contact thermometer (PT-7 LD, manufactured by Optics Co., Ltd.).

The measurement results of sample numbers 1 to 7 are shown in FIGS. 3A to 3G, respectively. In fig. 3A to 3G, "cooled" means a sample blown with cold air (10 ℃) before the drying process and cooled to about 20 ℃, and "uncooled" means a sample dried rapidly after the slurry casting without such cooling. From the results of fig. 3A to 3G, it is understood that the cooling of the slurry does not affect the temperature of the sample during the drying process.

Sample No. 1 employs the following conditions as hot air drying conditions: drying at a hot air temperature of 70 ℃ for 4 minutes, then at a hot air temperature of 80 ℃ for 4 minutes, and then at a hot air temperature of 120 ℃ for 4 minutes. The temperature of the sample increased with the increase in the temperature of the hot air, and finally exceeded 100 ℃ to approach 120 ℃ (fig. 3A). The "menthol content after storage" of the sheet of sample No. 1 was shown to be a low value of 13.6% (table 1). It is believed that the internal structure of the sheet was destroyed by the higher sample temperature and the menthol content decreased after storage.

Sample No. 2 was dried with hot air under the following conditions: drying at a hot air temperature of 120 ℃ for 2 minutes, then at a hot air temperature of 130 ℃ for 2 minutes, and then at a hot air temperature of 176 ℃ for 2 minutes. The temperature of the sample increased with the increase in the temperature of the hot air, and finally reached approximately 140 ℃ beyond 100 ℃ (fig. 3B). The "menthol content after storage" of the sheet of sample No. 2 was a low value of 29.2% (table 1). It is believed that the internal structure of the sheet was destroyed by the higher sample temperature and the menthol content decreased after storage.

Sample No. 3 employs the following conditions as hot air drying conditions: drying at 70 deg.C hot air temperature for 60 min. Fig. 3C shows the sample temperature from the start of drying to 14 minutes, but the sample temperature did not exceed 70 ℃ throughout the total drying time. The "menthol content after storage" of the sheet of sample No. 3 showed a high value of 59.2% (table 1). It is considered that since the sheet of sample No. 3 did not reach a high temperature throughout the total drying time, a high menthol content was maintained after storage in an accelerated environment. However, since the sheet of sample No. 3 was dried at a sample temperature of less than 70 ℃, a drying time of 60 minutes was required.

Sample No. 4 employs the following conditions as hot air drying conditions: drying was carried out at a hot air temperature of 120 ℃ for 5 minutes and then at a hot air temperature of 70 ℃ for 2.5 minutes. The sample temperature reached up to 95 ℃ at a hot air temperature of 120 ℃ and was reduced to 72 ℃ at a hot air temperature of 70 ℃ (fig. 3D). The "menthol content after storage" of the sheet of sample No. 4 showed a high value of 62.4% (table 1). It is considered that the sheet of sample No. 4 was kept at a lower sample temperature than those of sample nos. 1 and 2 throughout the total drying time, and therefore, a higher menthol content was maintained after storage in an accelerated environment.

Sample No. 5 used the following conditions as hot air drying conditions: drying was carried out at a hot air temperature of 120 ℃ for 4 minutes and then at a hot air temperature of 70 ℃ for 8 minutes. The sample temperature reached up to 95 ℃ at a hot air temperature of 120 ℃ and was reduced to 70 ℃ at a hot air temperature of 70 ℃ (fig. 3E). The "menthol content after storage" of the sheet of sample No. 5 was shown to be a high value of 58.5% (table 2). It is considered that the sheet of sample No. 5 was kept at a lower sample temperature than those of sample nos. 1 and 2 throughout the total drying time, and therefore, a higher menthol content could be maintained after storage in an accelerated environment.

Sample No. 6 was dried with hot air under the following conditions: drying was carried out at a hot air temperature of 110 ℃ for 2.2 minutes, then at a hot air temperature of 100 ℃ for 4.4 minutes, and then at a hot air temperature of 80 ℃ for 2.2 minutes. The sample temperature was maintained in the range of about 80 to 90 deg.C (FIG. 3F). The "menthol content after storage" of the sheet of sample No. 6 was shown to be a high value of 59.9% (table 3). It is considered that the sheet of sample No. 6 was kept at a lower sample temperature than those of sample nos. 1 and 2 throughout the total drying time, and therefore, a higher menthol content was maintained after storage in an accelerated environment.

Sample No. 7 was dried with hot air under the following conditions: drying was carried out at 100 ℃ hot air temperature for 8.8 minutes. The sample temperature was maintained in the range of about 80-90 deg.C (FIG. 3G). The "menthol content after storage" of the sheet of sample No. 7 showed a high value of 60.8% (table 3). It is considered that the sheet of sample No. 7 was kept at a lower sample temperature than those of sample nos. 1 and 2 throughout the total drying time, and therefore, a higher menthol content could be maintained after storage in an accelerated environment.

From the above results, it was found that if the slurry was dried at a sample temperature of not more than 100 ℃ for the total drying time, a high "menthol content after storage" could be maintained. It is also found that when the slurry is dried at a sample temperature of 70 to 100 ℃ for the total drying time (about 1 minute excluding the initial drying time), a sheet containing menthol can be formed in a short time.

[ example 6]

In this example, the effect of cooling the slurry before the drying step on the "menthol content after storage" of the menthol-containing sheet was confirmed. Specifically, as described in examples 1 to 3, sheets of sample numbers 1 to 7 were prepared, and the "menthol content after storage" of the sheet prepared by cooling the slurry was compared with the "menthol content after storage" of the sheet prepared without cooling the slurry for each sheet. Storage was carried out by placing the sheets in a thermostat set at 50 ℃ for 7 days, 14 days and 30 days as described in example 1.

The measurement results of sample numbers 1 to 3 are shown in FIG. 4A, and the measurement results of sample numbers 4 to 7 are shown in FIG. 4B. In FIGS. 4A and 4B, "cooled" means a sample blown with cold air (10 ℃ C.) before the drying process and cooled to about 20 ℃ or so, and "uncooled" means a sample dried rapidly after the slurry casting without such cooling. The "uncooled" samples did not have the slurry temperature below 50 ℃ during the slurry casting to drying.

The "cooled" data of fig. 4A and 4B are the same as the data of fig. 1.

The menthol content of the sheets of sample nos. 1 and 2 after being stored for 30 days was a low value of not more than 30% regardless of cooling.

The menthol content of the sheet of sample No. 3 after being left for 30 days was a high value exceeding 50% regardless of whether the sheet was cooled or not, but the preparation of the sheet of sample No. 3 required a drying time of 60 minutes.

The menthol content of the sheet of sample No. 4 after 30 days of storage was reduced to 18% in the case of "uncooled" compared to 62% in the case of "cooled".

The menthol content of the sheet of sample No. 5 after 30 days of storage was reduced to 20% in the case of "uncooled" compared to 59% in the case of "cooled".

The menthol content of the sheet of sample No. 6 after 30 days of storage was reduced to 20% in the case of "not cooled", compared to 60% in the case of "cooled".

The menthol content of the sheet of sample No. 7 after 30 days of storage was reduced to 12% in the case of "not cooled", compared to 61% in the case of "cooled".

From the above results, it is understood that when a sheet containing menthol is prepared by cooling the raw material slurry once and then drying the slurry at a sample temperature of 70 to 100 ℃, the sheet can be formed in a short time and a high menthol content can be maintained even after storage.

[ example 7]

In this example, the relationship between the cooling temperature of the slurry and the "initial menthol content" of the menthol-containing sheet was examined. Specifically, various sheets were prepared by changing the cooling temperature of the slurry to 20 ℃, 30 ℃, 40 ℃, 50 ℃ and 60 ℃ with respect to the sheet of sample No. 6 described in example 3. The menthol content of the sheet immediately after the production, i.e., "initial menthol content", was measured.

The measurement results are shown in fig. 5. From the results of fig. 5, it was confirmed that the lower the cooling temperature, the more the menthol content of the sheet tended to increase. That is, the menthol crystal exhibited an initial menthol content of 64% at a cooling temperature of 20 ℃, an initial menthol content of 61% at a cooling temperature of 30 ℃, an initial menthol content of 57% at a cooling temperature of 40 ℃, an initial menthol content of 52% at a cooling temperature of 50 ℃ and an initial menthol content of 43% at a cooling temperature of 60 ℃.

In example 4, it was shown that gelation of the slurry occurred at a cooling temperature of 40 ℃ or lower, and that the slurry containing the polysaccharide gelled when it was once cooled, and thereafter the temperature did not easily return to the sol even when it increased. In addition, it is known that generally, if the emulsion is below 0 ℃, the emulsion is frozen and broken.

From these results, it is found that the cooling temperature is preferably 0 to 40 ℃ and more preferably 0 to 30 ℃.

[ example 8]

In this example, the relationship between the moisture content of the menthol-containing sheet and the menthol fragrance retention rate was examined. Specifically, sheets having various moisture contents were prepared by increasing the conveying speed of the conveyor in the hot air dryer so that the total drying time of the slurry became 8.16 minutes, 7.92 minutes, 7.64 minutes, 7.44 minutes, and 7.08 minutes with respect to the sheet of sample No. 6 described in example 3. The moisture content of the prepared sheet was measured. The preparation conditions and the water content of the sheet are shown in table 4 below.

[ Table 4]

Sample number	8-1	8-2	8-3	8-4	8-5
						Conveying speed of conveying belt	1.13m/min	1.07m/min	1.04m/min	1.01m/min	0.98m/min
Total drying time	7.08 minutes	7.44 minutes	7.64 minutes	7.92 minutes	8.16 minutes
						Moisture content after drying	22.6wt%	14.6wt%	11.2wt%	8.6wt%	6.1wt%

The prepared sheet was placed in a thermostat set at 50 ℃ for 30 days as described in example 1. The menthol content of the sheets immediately after the production and after the storage was measured, and the respective measurement results are shown in table 5 below as "initial menthol content" and "menthol content of the sheet stored immediately after the production". From these values of the menthol content, the menthol fragrance retention ratio was calculated by the following formula.

Menthol fragrance retention rate (%) { (menthol content after storage)/(initial menthol content) } × 100

The result is shown in fig. 6 as "accelerator apparatus immediately after manufacture".

In addition, the sheet after 2 months of preparation was placed in a thermostat set at 50 ℃ for 30 days as described in example 1. The menthol content of the sheet immediately after the preparation and after the storage was measured, and the respective measurement results are shown in table 5 below as "initial menthol content" and "menthol content of the sheet stored 2 months after the preparation". In addition, the menthol fragrance retention rate was calculated from the above formula. The results are shown in FIG. 6 as "Accelerator after 2 months of manufacture".

[ Table 5]

The menthol content of the sheet immediately after the preparation was about 50 to 60% in each of sample numbers 8-1 to 8-5.

In an experiment in which the sheet immediately after preparation was stored in an accelerated environment, the sheet having a moisture content of about 6% (sample No. 8-5) showed a menthol retention rate of 93%, the sheet having a moisture content of about 9% (sample No. 8-4) showed a menthol retention rate of 90%, the sheet having a moisture content of about 11% (sample No. 8-3) showed a menthol retention rate of 87%, the sheet having a moisture content of about 15% (sample No. 8-2) showed a menthol retention rate of 63%, and the sheet having a moisture content of about 23% (sample No. 8-1) showed a menthol retention rate of 6%.

In an experiment in which the sheet after 2 months of preparation was stored in an accelerated environment, the sheet having a moisture content of about 6% (sample No. 8-5) showed a menthol retention rate of 95%, the sheet having a moisture content of about 9% (sample No. 8-4) showed a menthol retention rate of 87%, the sheet having a moisture content of about 11% (sample No. 8-3) showed a menthol retention rate of 32%, the sheet having a moisture content of about 15% (sample No. 8-2) showed a menthol retention rate of 8%, and the sheet having a moisture content of about 23% (sample No. 8-1) showed a menthol retention rate of 8%.

From these results, it is understood that the menthol fragrance retention rate decreases rapidly as the moisture content of the sheet increases, and therefore, the sheet is preferably dried so that the moisture content of the sheet is less than 10%, preferably 9% or less. In particular, it was found that even when the sheet 2 months after the preparation was further stored in an accelerated environment, a high menthol-retaining rate could be maintained if the moisture content of the sheet was about 9% or less.

When the moisture content of the sheet is less than 3%, the menthol retention rate is good, but the sheet is preferably dried to a moisture content of 3% or more because "cracks" and "drops" occur in the sheet.

Claims (9)

1. A method for producing a flavor-containing sheet for a smoking article, comprising the steps of:

spreading a raw material slurry in a sol state at 60 to 90 ℃ on a base material, the raw material slurry containing polysaccharides and perfume and having a water content of 70 to 95 wt%;

a step of cooling the spread raw material slurry to a sample temperature of 0 to 30 ℃ to cause gelation; and

a heating and drying step of heating the gelled raw material and drying the heated gelled raw material at a sample temperature of 70 to 100 ℃ for a drying time of 20 minutes or less,

the polysaccharide is a single-component system of carrageenan, agar or gellan gum; or a composite system comprising 1 or more ingredients selected from locust bean gum, guar gum, tamarind gum, xanthan gum, tara gum, konjac glucomannan, cassia gum and plantain seed gum, and carrageenan, agar or gellan gum.

2. The method for producing a flavor-containing sheet for a smoking article according to claim 1, wherein the heat-drying step is performed so that the sample temperature is 100 ℃ or lower throughout the entire period of the step.

3. The method of producing a flavor-containing sheet for a smoking article according to claim 1 or 2, wherein the heat-drying step is a step of drying the raw material to a sheet form having a moisture content of less than 10% in a total heat-drying time of 20 minutes or less.

4. The method for producing a flavor-containing sheet for a smoking article according to claim 1 or 2, wherein the heat drying step is a step of: the gelled raw material is dried in a sheet form having a moisture content of less than 10% for a total heating and drying time of 20 minutes or less by initially drying the raw material by blowing hot air at a temperature of 100 ℃ or more for a time of 1/4 or more of the total heating and drying time, and then by blowing hot air at a temperature of less than 100 ℃ for a time of 1/4 or more of the total heating and drying time, and by performing post-drying.

5. A tablet-containing material for a smoking article, produced by the method of any one of claims 1 to 4.

6. A flavour-containing sheet for a smoking article according to claim 5, wherein the flavour is menthol.

7. The flavor-containing sheet for a smoking article according to claim 6, wherein the menthol content in the produced sheet is 45% by weight or more, and the menthol content in the sheet after storage at 50 ℃ for 30 days is 45% by weight or more.

8. A smoking article comprising a cut tobacco, wherein the cut tobacco is blended with the flavor-containing sheet for smoking articles according to any one of claims 5 to 7.

9. A cigarette, comprising: a tobacco rod comprising a tobacco shred and a cigarette wrapper wound around the tobacco shred, wherein a cut product of the flavor-containing sheet for smoking articles according to any one of claims 5 to 7 is blended in the tobacco shred.