HK1189773B - Method for producing flavoring-containing sheet for smoking article, flavoring-containing sheet for smoking article produced thereby, and smoking article comprising same - Google Patents

Description

Method for producing flavor-containing sheet for smoking article, flavor-containing sheet for smoking article produced by the method, and smoking article comprising the sheet

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 ℃.

As described above, various techniques for suppressing volatilization of perfume components have been reported, and it is desired to produce a perfume raw material having a higher storability by a simple method.

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 invention aims 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: when a perfume-containing sheet is produced by heat-drying a raw material slurry containing a polysaccharide, a perfume and an emulsifier, a sheet having a high perfume content and a high perfume production yield can be produced by using gellan gum and tamarind gum in combination as the polysaccharide and drying the sheet after cooling the sheet before heat-drying, and it has been found that the emulsion stability of the raw material slurry can be improved by using gellan gum and tamarind gum in combination as the polysaccharide, 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 60-90 ℃ on a base material, wherein the raw material slurry contains polysaccharides composed of gellan gum and tamarind gum, perfume, emulsifier, and 70-95 wt% of water, and the weight ratio of the gellan gum to the tamarind gum is in the range of 1: 1-3: 1; 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 for heating the gelled raw material and drying the heated raw material at a sample temperature of 70 to 100 ℃.

According to a preferred embodiment, the emulsifier is lecithin. Alternatively, according to a preferred embodiment, the emulsifier is an ester selected from the group consisting of a glycerin fatty acid ester, a polyglycerin fatty acid ester, a sorbitan fatty acid ester, a polyoxyethylene sorbitan fatty acid ester, a propylene glycol fatty acid ester, and a sucrose fatty acid ester.

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.

FIG. 7A is a graph showing the relationship between the compounding ratio of tamarind gum and the menthol content of a sheet containing gellan gum/tamarind gum.

Fig. 7B is a graph showing the relationship between the compounding ratio of locust bean gum and the menthol content of a sheet containing gellan gum/locust bean gum.

Fig. 7C is a graph showing the relationship between the blending ratio of starch and the menthol content of the sheet containing gellan gum/starch.

Fig. 8A is a graph showing the relationship between the amount of lecithin incorporated and the menthol content of the menthol-containing sheet (in the case of using gellan gum as the polysaccharide).

Fig. 8B is a graph showing the relationship between the amount of lecithin incorporated and the menthol content of the menthol-containing sheet (in the case of using gellan gum and tamarind gum in combination as the polysaccharide).

Fig. 9 is a graph showing the relationship between the compounding ratio of tamarind gum and the menthol content of a sheet containing gellan gum/tamarind gum when left standing after the raw material slurry is prepared.

FIG. 10 is a graph showing the effect of the type of emulsifier on the menthol content of a sheet containing gellan gum/tamarind gum.

Fig. 11A is a graph showing changes in viscosity with temperature drops of raw material slurries containing polysaccharides (mixtures of gellan gum and tamarind gum) at various concentrations.

Fig. 11B is a graph showing changes in viscosity with temperature increases of raw material slurries containing polysaccharides (a mixture of gellan gum and tamarind gum) at various concentrations.

Fig. 11C is a graph showing the content of menthol after storage of menthol-containing sheets prepared using raw material slurries of polysaccharides (a mixture of gellan gum and tamarind gum) at various concentrations.

Fig. 12A is a graph showing the menthol content after storage of menthol-containing sheets prepared using raw material slurries containing polysaccharides (a mixture of gellan gum and tamarind gum) and menthol at various ratios.

Fig. 12B is a graph showing the menthol fragrance retention of menthol-containing sheets prepared using raw material slurries containing a polysaccharide (a mixture of gellan gum and tamarind gum) and menthol at various ratios.

Fig. 12C is a graph showing the menthol yield of menthol-containing sheets prepared using raw material slurries containing a polysaccharide (a mixture of gellan gum and tamarind gum) and menthol at various ratios.

Fig. 12D is a graph showing the relationship between the blending ratio of menthol and the menthol content of the menthol-containing sheet (in the case of using gellan gum and tamarind gum in combination as polysaccharides).

Fig. 12E is a graph showing the relationship between the blending ratio of menthol and the menthol yield of the menthol-containing sheet (in the case of using gellan gum and tamarind gum in combination as polysaccharides).

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 and an oil-soluble perfume. 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) can be produced by a method including the steps of: spreading a raw material slurry in a sol state at 60-90 ℃ on a base material, wherein the raw material slurry contains polysaccharides composed of gellan gum and tamarind gum, menthol, an emulsifier, and 70-95 wt% of water, and the weight ratio of the gellan gum to the tamarind gum is in the range of 1: 1-3: 1; 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 for heating the gelled raw material and drying the heated 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).

(1) Preparation of raw slurry

The raw material slurry in the present invention can be prepared by a method comprising the following steps: (i) mixing and heating a polysaccharide consisting of a mixture of gellan gum and tamarind gum, wherein the weight ratio of gellan gum to tamarind gum is in the range of 1:1 to 3:1, with water to prepare an aqueous solution of the polysaccharide; and (ii) a step of adding menthol and an emulsifier to the aqueous solution, kneading the mixture, and emulsifying the kneaded 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 polysaccharide (i.e., a mixture of gellan gum and tamarind gum) is preferably contained in the raw material slurry at a concentration of 2 to 7 wt%. For example, when 10L of water is used as a solvent for the raw material slurry, the raw material slurry may contain 200 to 700g of polysaccharides. More preferably, the polysaccharide is contained in the raw material slurry at a concentration of 3 to 5 wt% (see example 13 described later).

The raw material slurry may be mixed with, for example, 500g of polysaccharides, 500 to 5000g of menthol, and 50 to 500ml of 5 wt% emulsifier solution, with respect to 10L of water. Wherein the polysaccharides comprise 250-375 g of gellan gum and 125-250 g of tamarind gum, and the total weight of the gellan gum and tamarind gum is 500 g.

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: 5, preferably 1: 2.5-1: 5. that is, the amount of menthol added may be 100 to 500 wt% with respect to the polysaccharide, and preferably 250 to 500 wt% with respect to the polysaccharide (see example 14 described later).

The polysaccharides in the raw material slurry are composed of gellan gum and tamarind gum, and the weight ratio of the gellan gum to the tamarind gum is in the range of 1:1 to 3:1 (see example 9 described later). Specifically, the polysaccharides in the raw material slurry are composed of gellan gum and tamarind gum, and the gellan gum is contained in a weight ratio of 50 to 75%.

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 present inventors have found that polysaccharides composed of gellan gum and tamarind gum exhibit particularly excellent sol-gel transition characteristics with respect to temperature in an aqueous solution (see example 13 described later). That is, an aqueous solution containing a gellan gum and a tamarind gum is once cooled to gel, and thereafter, is unlikely to return to a sol even if the temperature rises, and has a property of maintaining a gel state (see fig. 11B). By virtue of this characteristic, menthol coated with polysaccharides including gellan gum and tamarind gum is once cooled, and the coating film thereof does not return to a sol even when exposed to high temperatures in the heat drying step, and menthol in the coating film can be stably retained (see sample numbers 4 to 7 and fig. 11C in fig. 1). In the present invention, such a characteristic is referred to as "temperature-sensitive sol-gel transition characteristic".

Thus, polysaccharides having a temperature-sensitive sol-gel transition property have an advantage of coating menthol and realizing high storability, and have an advantage of gelation by utilizing the temperature-sensitive sol-gel transition property and also having an advantage of not requiring addition of a metal ion (gelation accelerator).

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

In the present invention, as the emulsifier, a natural emulsifier such as lecithin, specifically Sun LecithinA a-1 (Sun chemical Co., Ltd.) can be used.

When lecithin is used as the emulsifier, lecithin may be contained in the slurry in an amount of 1 to 10% by weight, preferably 1 to 5% by weight, based on the polysaccharide (see example 10 described later).

As the emulsifier, in addition to lecithin, an ester selected from the group consisting of glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, propylene glycol fatty acid ester and sucrose fatty acid ester can be used.

Glycerin fatty acid esters include, for example, fatty acid monoglycerides such as monoglyceride monostearate and monoglyceride succinate; the polyglycerin fatty acid ester contains, for example, pentaglycerol monostearate; sorbitan fatty acid esters include, for example, sorbitan monostearate; the polyoxyethylene sorbitan fatty acid ester includes, for example, polyoxyethylene sorbitan monostearate; propylene glycol fatty acid esters include, for example, propylene glycol monostearate; the sucrose fatty acid ester includes, for example, sucrose stearate (see example 12 described later). The amount of these emulsifiers contained in the slurry is 1 to 10% by weight based on the polysaccharides, preferably 1 to 5% by weight based on the polysaccharides.

These emulsifiers have a function of emulsifying and dispersing micelles of menthol coated with polysaccharides in water. The present inventors have newly found that when gellan gum is used alone as a polysaccharide and lecithin is blended as an emulsifier at a high concentration into a raw material, a stable emulsified state of the raw material cannot be produced, and that when gellan gum and tamarind gum are used in combination as a polysaccharide, the emulsified state of the raw material can be stably maintained even when the amount of the lecithin blended is high (see example 10 described later). In addition, the present inventors newly found that a raw material slurry containing only gellan gum as a polysaccharide causes a slightly unstable emulsified state of the raw material when left to stand after the production, whereas a raw material slurry containing gellan gum and tamarind gum as a polysaccharide can stably maintain the emulsified state of the raw material even when left to stand after the production (see example 11 described later).

As described above, since the raw material slurry containing gellan gum and tamarind gum has a property of stably maintaining the emulsified state of the raw materials (i.e., emulsion stability), the menthol content of the produced sheet can be stably maintained after storage by the emulsion stability.

(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 process for producing the menthol-containing sheet of the present invention, the spread raw material slurry is temporarily cooled to a temperature (0 ℃ or higher) at which the slurry is sufficiently gelled (40 ℃ or lower) and the emulsion is not frozen and broken, that is, a temperature of 0 to 40 ℃, preferably 0 to 30 ℃, and more preferably 15 to 25 ℃ before being dried. 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 can be carried out by: the spread raw material slurry is blown with cold air (e.g., 10 ℃) generated only by an air blower or a local cooler (e.g., Sudden SS-25DD-1) for 2 to 3 minutes, or 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, Apist PCU-1600R) flows for 1 to 2 minutes, or 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 at a temperature at which the solution is converted into a gel even when the temperature is increased thereafter, and has a property of maintaining the gelled state. In the present invention, when the raw material slurry is pre-cooled before being dried by utilizing such a property, it is confirmed that the polysaccharide contained in the pre-cooled raw material slurry is not easily gelled even if the temperature of the pre-cooled raw material slurry is increased during drying, and the menthol coated with the polysaccharide is not easily volatilized.

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 not deformed (collapsed) even if exposed to a high temperature in a subsequent drying process.

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

(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. By drying at such a sample temperature, volatilization of menthol can be prevented, and a menthol-containing sheet can be produced in a short 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 flavor such as menthol, it is preferable that the period during 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 to a form having a moisture content of less than 10% in 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 ℃). Thereby, the rise of the sample temperature in the later stage of drying can be suppressed, and the test temperature can be kept, for example, not more than 100 ℃ throughout the total drying time.

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 moisture on the surface of the raw material slurry is evaporated at a hot air temperature of 100 ℃ to 130 ℃ to perform initial drying until a sufficient film is formed on the surface of the slurry, and then the temperature is rapidly switched to a hot air temperature of 70 ℃ to less than 100 ℃ to perform 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 wind during the post-drying may be constant or may be changed to be decreased in order between 700 ℃ or more and less 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 cigarettes having tobacco rods each comprising tobacco shreds and a cigarette wrapper 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 (Vis Top D-2032/Sanrongyuan F.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 stirring rotor/2000 rpm) while maintaining water (10L) at 80 ℃ gellan gum (150g) and tamarind gum (150g) were dissolved in small portions without caking (required time about 20 minutes), and menthol (1500g) 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 (120mL (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 through a slit die, and then blown with cold air (10 ℃) generated by a local cooler (SuidenSS-25DD-1) for 2 to 3 minutes to cool the raw material slurry to about 20 ℃, and then hot-air dried by conveying the raw material slurry with a conveyor belt in a hot air dryer to obtain a film-shaped 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 7.5m)

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

: a second 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)

Sample introduction amount: 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 shown to be 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]

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.

[ example 9]

In this example, the effect of the polysaccharide composition (i.e., a mixture of gellan gum and tamarind gum, a mixture of gellan gum and locust bean gum, and a mixture of gellan gum and starch) on the menthol content of the menthol-containing sheet was examined.

9-1. method (preparation of sheet)

(1) Sheet material containing gellan gum/tamarind gum

The composition of the raw material slurry is as follows.

10L of water

Polysaccharide (mixture of gellan gum and tamarind gum) 300g

120mL of 5% aqueous Lecithin solution (Sun Lecithin A-1/Suchen Chemicals, Ltd.)

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

The mixing ratio (weight ratio) of gellan gum and tamarind gum was changed as follows.

Gellan gum: tamarind gum =100:0

Gellan gum: tamarind gum =75:25

Gellan gum: tamarind gum =50:50

Gellan gum: tamarind gum =33:67

Gellan gum: tamarind gum =17:83

As the gellan gum, Sanrong-derived F.F.I Kelcogel (deacylated type gellan gum) was used, and as the tamarind gum, Sanrong-derived F.I Vis Top D-2032 was used.

10L (100 parts by weight) of water (heated and held at 80 ℃ C.) was mixed with a mixer (PRIMIX T. K. AUTO MIXERModel 40/mounting solution stirring rotor/2000 rpm) to dissolve 300g (3 parts by weight) of both polysaccharides in the mixture ratio (weight ratio) in small portions without caking (required time of about 20 minutes). 1500g (15 parts by weight) of 1-menthol were added at this temperature. The mixture was emulsified for 10 minutes by changing the stirring dispersion to a homogenizer (PRIMIX T. K. AUTO MIXER Model 40/rotor head mounted/4000 rpm), and 120mL (1.2 parts by weight) of a 5% aqueous lecithin solution was added thereto and stirred. Menthol is dispersed in an aqueous solution of a mixed polysaccharide of gellan gum and tamarind gum.

The dispersed slurry was cast onto a base material (PET film, Futamura chemical Co., Ltd., FE2001) to a thickness of 1mm (wet state). Then, the resultant was cooled to about 20 ℃ by cold air of about 10 ℃ generated by a local cooler (Suiden SS-25 DD-1).

Then, the sheet was dried and molded by a hot air type dryer in the same manner as in example 1 until the moisture content was about 6%, to prepare a sheet (hereinafter, referred to as a sheet containing gellan gum/tamarind gum). The moisture content was measured by GC-TCD measurement (see example 1). The hot air drying conditions adopted were as follows: drying at a hot air temperature of 110 ℃ for 3 minutes, then at a hot air temperature of 100 ℃ for 6 minutes, and then at a hot air temperature of 80 ℃ for 3 minutes (total drying time 12 minutes).

(2) Sheet material containing gellan gum/locust bean gum

A raw material slurry containing gellan gum and locust bean gum (Wako pure chemical industries, Ltd.) at the following mixing ratio (weight ratio) was prepared in the same manner as in (1) sheet containing gellan gum/tamarind gum. The composition of the raw material slurry was the same as that of (1) the sheet containing gellan gum/tamarind gum, except for the polysaccharides.

Gellan gum: locust bean gum =100:0

Gellan gum: locust bean gum =83:17

Gellan gum: locust bean gum =67:33

Gellan gum: locust bean gum =50:50

Gellan gum: locust bean gum =33:67

Gellan gum: locust bean gum =17:83

Gellan gum: locust bean gum =0:100

A sheet (hereinafter, referred to as a sheet containing gellan gum/locust bean gum) was prepared in the same manner as in (1) above using each raw material slurry.

(3) Sheet material containing gellan gum/starch

Prepared according to the same method as (1) sheet containing gellan/tamarind gum in a ratio of 50: a mixing ratio (weight ratio) of 50 contained the raw material slurry of gellan gum and starch. The composition of the raw material slurry was the same as that of (1) the sheet containing gellan gum/tamarind gum, except for the polysaccharides.

As the starch, 2 types of "starch derived from corn (and Special grade reagent from Wako pure chemical industries, Ltd.)" and "starch (soluble) (and Wako pure chemical industries, Ltd., first grade)" as "soluble starch" were used. In the case of using either normal starch or soluble starch, the viscosity of the raw material slurry is low, and it is difficult to maintain the thickness of the sample during casting, and therefore, the mixing ratio of gellan gum and starch is set to only 50: 50.

a sheet (hereinafter, referred to as a sheet containing gellan gum/starch) was produced in the same manner as in (1) above using each raw material slurry.

Method 9-2 (determination of menthol content)

The menthol content of the sheet immediately after the production (initial menthol content) and the menthol content of the sheet stored in an accelerated environment (menthol content after the storage) were measured. Accelerated environment the menthol content was measured in the same manner as in example 1, as described in example 1. The results of the sheet containing gellan gum/tamarind gum are shown in fig. 7A, the results of the sheet containing gellan gum/locust bean gum are shown in fig. 7B, and the results of the sheet containing gellan gum/starch are shown in fig. 7C. In FIGS. 7A to 7C, "immediately after production" means immediately after the sheet is produced, and "after 1 month at 50 ℃" means after 30 days of storage at 50 ℃.

9-3. results

(1) Sheet material containing gellan gum/tamarind gum

As shown in fig. 7A, the initial menthol content showed a high value exceeding 60% in all sheets regardless of the mixing ratio of gellan gum and tamarind gum. The menthol content after storage is 100% in the mixing ratio of gellan gum to tamarind gum: 0. 75: 25. 50: in the case of 50, a high value (about 60% or more) can be maintained to the same extent as the initial menthol content, but the mixing ratio of gellan gum and tamarind gum is 33: 67. 17:83, to 33% and 18%, respectively.

(2) Sheet material containing gellan gum/locust bean gum

As shown in fig. 7B, when the blending ratio of locust bean gum was high, the menthol content tended to decrease both immediately after the sheet was produced and after storage. Specifically, in the case where the blend ratio of locust bean gum is 17%, the initial menthol content is about 70%, and the menthol content after storage is about 63%; in the case of the compounding ratio of 33%, the initial menthol content was about 68% and the menthol content after storage was about 54%; when the mixing ratio is 50%, the initial menthol content is about 63% and the menthol content after storage is about 45%; when the compounding ratio is 67%, the initial menthol content is about 59% and the menthol content after storage is about 31%; when the compounding ratio is 83%, the initial menthol content is about 53% and the menthol content after storage is about 15%.

(3) Sheet material containing gellan gum/starch

As shown in fig. 7C, when the common starch was blended at a blending ratio of 50%, the initial menthol content was about 26%, and the menthol content after storage was about 19%. When soluble starch was blended at a blending ratio of 50%, the initial menthol content was about 34% and the menthol content after storage was about 21%.

[ example 10]

In this example, the raw material slurry containing gellan gum alone as a polysaccharide was emulsified and mixed in a ratio of 1: the emulsion stability of the raw material slurry containing gellan gum and tamarind gum at a weight ratio of 1 as polysaccharides was compared. Regarding the emulsion stability, it was examined how the menthol content of the produced sheet changes with respect to the blending amount of the emulsifier.

Lecithin was used as an emulsifier, and the amount of lecithin added was varied from 0.001 to 0.4 times by weight based on the weight of the polysaccharide (gellan gum alone or a mixture of gellan gum and tamarind gum) in the raw material slurry. That is, the amount of lecithin added was 0.001 times, 0.005 times, 0.01 times, 0.02 times, 0.05 times, 0.1 times, 0.2 times, and 0.4 times the weight of the polysaccharide.

Method 10-1 (preparation of sheet)

(1) Production of sheet Using raw Material slurry containing Gellan Gum alone as polysaccharide

10L of water

Gellan gum (Kelcogel/Sanrongyuan F.F.I) 300g

5% Lecithin in water (Sun Lecithin A-1/Suchen Chemicals, Ltd.)

6mL (0.001-fold amount) to 300mL (0.05-fold amount)

Alternatively, Lecithin powder (Sun Lecithin A-1 (powder)/Sun chemical (strain))

30g (0.1-fold amount) to 120g (0.4-fold amount)

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

Using the composition of the raw material slurry, a sheet (hereinafter, referred to as a sheet containing gellan gum) was prepared in the same manner as in example 9.

(2) A method of using a mixture of 1:1 weight ratio of gellan gum and tamarind gum as raw material slurry for production of sheet

10L of water

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

Tamarind gum (Vis Top D-2032/Sanrongyuan F.F.I) 150g

5% Lecithin in water (Sun Lecithin A-1/Suchen Chemicals, Ltd.)

6mL (0.001-fold amount) to 300mL (0.05-fold amount)

Alternatively, Lecithin powder (Sun Lecithin A-1 (powder)/Sun chemical (strain))

30g (0.1-fold amount) to 120g (0.4-fold amount)

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

Using the composition of the raw material slurry described above, a sheet (hereinafter, referred to as a sheet containing gellan gum/tamarind gum) was prepared in the same manner as in example 9.

Method 10-2 (determination of menthol content)

The menthol content of the sheet immediately after the production (initial menthol content) and the menthol content of the sheet stored in an accelerated environment (menthol content after the storage) were measured. Accelerated environment the menthol content was measured in the same manner as in example 1, as described in example 1. The results of the sheet containing gellan gum are shown in fig. 8A, and the results of the sheet containing gellan gum/tamarind gum are shown in fig. 8B. In FIGS. 8A and 8B, "immediately after production" means immediately after production of the sheet, and "after 1 month at 50 ℃ means after 30 days of storage at 50 ℃.

10-3. results

Fig. 8A shows the relationship between the lecithin content (weight ratio to gellan gum) and the menthol content (%) of a sheet containing gellan gum. As shown in fig. 8A, the initial menthol content was not dependent on the lecithin content, and showed a high value exceeding 60% in all sheets. The menthol content after storage can be maintained at a high value (about 60% or more) to the same extent as the initial menthol content when the lecithin content is in the range of 0.005 to 0.05 times by weight relative to gellan gum, but can be reduced to 9%, 3%, and 2% when the lecithin content is in the range of 0.1, 0.2, and 0.4 times by weight relative to gellan gum. This indicates that if lecithin is present in a high concentration in the raw material, a stable emulsified state of the raw material cannot be produced.

Fig. 8B shows the relationship between the lecithin content (weight ratio to the mixture of gellan gum and tamarind gum) and the menthol content (%) of the sheet containing gellan gum/tamarind gum. As shown in fig. 8B, the initial menthol content showed a high value in the range of about 56 to 73% in the sheets having various lecithin incorporation amounts. The menthol content after storage can be a high value (about 47 to 61%) when the amount of lecithin added is in the range of 0.01 to 0.1 times by weight of the polysaccharide. This result shows that a higher menthol content can be maintained even after storage when the amount of lecithin blended is more than 0.05 times the weight of the polysaccharide, unlike the case of a sheet containing gellan gum. This indicates that the use of gellan gum and tamarind gum in combination as the polysaccharide makes it possible to stably maintain the emulsified state of the raw material even when the amount of lecithin is high.

[ example 11]

In this example, the effect of the composition of the polysaccharide (i.e., the mixing ratio of gellan gum and tamarind gum) on the emulsion stability of the raw material slurry was examined. Regarding the emulsion stability, it was examined how the menthol content of the produced sheet changes when the sheet was left for a predetermined time after the raw material slurry was prepared. Specifically, a sheet containing menthol was prepared by preparing a raw material slurry, leaving the slurry for a predetermined period of time, and then heating the slurry again to cause the sol, and the effect of the composition of the polysaccharide (i.e., the mixing ratio of gellan gum and tamarind gum) on the content of menthol was examined.

Method 11-1 (preparation of sheet)

A raw material slurry containing gellan gum and tamarind gum as polysaccharides in the following mixing ratio (weight ratio) was prepared in the same manner as in example 9. The composition of the raw material slurry was the same as that of example 9 (1) sheet containing gellan gum/tamarind gum.

Gellan gum: tamarind gum =100:0

Gellan gum: tamarind gum =75:25

Gellan gum: tamarind gum =50:50

Gellan gum: tamarind gum =25:75

The prepared raw material slurry was left to stand at room temperature for one night or more in a state of being stored in a polystyrene container. The raw material slurry was allowed to cool to gel. Then, the gelled raw material was heated to 80 ℃ or higher with a microwave heating cooker (output 500W. microwave oven) to be sol-ized. Using the obtained raw material slurry, a sheet (hereinafter referred to as a sheet containing gellan gum/tamarind gum) was prepared in the same manner as in example 9.

Method (determination of menthol content)

The menthol content of the sheet immediately after the production (initial menthol content) and the menthol content of the sheet stored in an accelerated environment (menthol content after the storage) were measured. The accelerated environment was the same as that described in example 1, and the menthol content was measured by the same method as in example 1. Fig. 9 shows the measurement results as the relationship between the blend ratio of tamarind gum and the menthol content. In FIG. 9, "immediately after production" means immediately after the sheet is produced, "after 1 month at 50 ℃ means after 30 days of storage at 50 ℃.

11-3. results

As shown in fig. 9, in the present example (that is, in the case of preparing a sheet after preparing a raw material slurry and leaving it for a predetermined time), the initial menthol content of the sheet (sheet containing gellan gum) having a tamarind gum blending ratio of 0% was about 50%, and the menthol content after storage was about 46%. In contrast, as shown in fig. 7A, in the case of rapidly preparing a sheet after preparing the raw material slurry, the initial menthol content of the sheet in which the compounding ratio of tamarind gum is 0% is about 67%, and the menthol content after storage is about 70%. As described above, when a raw material slurry containing only gellan gum as a polysaccharide is left to stand after preparation, the emulsified state of the raw material becomes slightly unstable, resulting in a decrease in the initial menthol content.

In this example, the initial menthol content of the sheet containing 25% tamarind gum was about 61%, and the menthol content after storage was about 58%. The sheet material containing tamarind gum at a compounding ratio of 50% had an initial menthol content of about 63% and a menthol content after storage of about 59%. As described above, when tamarind gum is blended in a predetermined ratio in the raw material slurry, the emulsified state of the raw materials can be stably maintained even when left to stand after the raw material slurry is prepared, and a high menthol content can be maintained even after the raw material slurry is stored.

In this example, the initial menthol content of the sheet with a tamarind gum blending ratio of 75% was about 66%, and the menthol content after storage was about 29%. This result is similar to the result obtained when a sheet was produced immediately after the production of the raw material slurry (see fig. 7A), and is considered to be caused by the high blending ratio of the tamarind gum.

From the above results, in order to stably maintain the emulsified state of the raw materials after the preparation of the raw material slurry, it is preferable to maintain the ratio of 50: 50-75: gellan gum and tamarind gum were used as polysaccharides at a mixing ratio (weight ratio) of 25. In other words, if the ratio of 50: 50-75: a mixing ratio (weight ratio) of 25 contains gellan gum and tamarind gum, and even in the case of preparing a sheet by preparing a raw material slurry in advance and then heating the raw material again as needed, the sheet can maintain a high menthol content after being stored. Thus, the raw material slurry can be prepared in advance.

In order to satisfy the high fragrance retention in storage and high emulsion stability, it is preferable to combine the results of examples 9 to 11 in a ratio of 50: 50-75: gellan gum and tamarind gum were used in a weight ratio of 25.

[ example 12]

In this example, the effect of the type of emulsifier on the menthol content of the menthol-containing sheet after storage was examined.

Method 12-1 (preparation of sheet and determination of menthol content)

Sheets containing gellan/tamarind gum were prepared using stock slurries containing various types of emulsifiers. Sheet preparation was carried out in the same manner as in example 9. The mixing ratio (weight ratio) of gellan gum to tamarind gum was set to 1: 1.

as the emulsifier, the following 8 kinds of emulsifiers were used. The numbers 1 to 8 attached to the emulsifiers correspond to those of FIG. 10.

1. Lecithin

(Sun chemical Co., Ltd Sun LecithinA-1)

2. Glycerin fatty acid ester (monoglyceride)

(EXCEL S-95, manufactured by Kao corporation)

Compound name: oleophilic glyceryl monostearate

3. Glycerin fatty acid ester (polyglycerol ester)

(A-181E manufactured by Suzuki chemical Co., Ltd.)

Compound name: pentaglycerol monostearate

4. Glycerin fatty acid ester (organic acid monoglyceride)

(Step SS manufactured by Kao corporation)

Compound name: succinic acid monoglyceride

5. Sorbitan fatty acid ester

(Emasol S-10V, product of Kao corporation)

Compound name: sorbitan monostearate

6. Sorbitan fatty acid ester (Polysorbate)

(Emasol S-120V, manufactured by Kao corporation)

Compound name: polyoxyethylene sorbitan monostearate

7. Propylene glycol fatty acid ester

(product of Suntai chemical Co., Ltd., No.25CD)

Compound name: propylene glycol monostearate

8. Sucrose fatty acid ester

(Ryoto Sugar Ester S-1570 manufactured by Mitsubishi chemical food Co., Ltd.)

Compound name: sucrose stearate

The menthol content of the sheet immediately after the production (initial menthol content) and the menthol content of the sheet stored in an accelerated environment (menthol content after the storage) were measured. The accelerated environment was the same as that described in example 1, and the menthol content was measured by the same method as in example 1. The measurement results of the menthol content are shown in fig. 10. In FIG. 10, "immediately after production" means immediately after the sheet is produced, "after 1 month at 50 ℃ means after 30 days of storage at 50 ℃.

12-2. results

From the results of fig. 10, it is understood that various emulsifiers other than lecithin can be used. In the production of a sheet containing gellan gum/tamarind gum, 1. lecithin, 3. glycerin fatty acid ester (polyglycerin ester), and 4. glycerin fatty acid ester (organic acid monoglyceride) are particularly preferably used as an emulsifier.

Example 13

In this example, the effect of the concentration of the polysaccharide on the menthol content of the menthol-containing sheet after storage was examined.

Method (temperature sensitive Sol-gel transition Properties)

In this experiment, temperature-sensitive sol-gel transition characteristics of raw material slurries (sheet preparation liquids) containing polysaccharides (mixtures of gellan gum and tamarind gum) at various concentrations were examined. As the polysaccharide, gellan gum and tamarind gum were used in a weight ratio of 1: 1.1 part by weight (1%), 2 parts by weight (2%), 3 parts by weight (3%), 5 parts by weight (5%) and 7 parts by weight (7%) were used with respect to the concentration of the polysaccharide (a mixture of gellan gum and tamarind gum) in water (100 parts by weight). In the following description and fig. 11A to 11C, the concentration of the polysaccharide is expressed as a weight percentage (%) with respect to water.

According to the description of example 9, a raw material slurry containing gellan gum and tamarind gum as polysaccharides was prepared. Menthol was added in an amount 5 times (by weight) the amount of the polysaccharide, and a 5% aqueous lecithin solution was added in an amount 2/5 times (by weight) the amount of the polysaccharide, depending on the concentration of the polysaccharide.

The raw material slurry containing polysaccharides at each concentration was brought to 25 ℃ from 70 ℃ over about 900 seconds. Then, the temperature was raised to 70 ℃ over about 900 seconds. The rheometer (manufactured by Thermo-Haake, RheoStress1) was used to determine how the viscosity (fluidity) of the slurry changed by lowering and raising the temperature. The results are shown in FIGS. 11A and 11B.

Results (temperature sensitive Sol-gel transition characteristics)

As shown in fig. 11A, in the case of a raw material slurry containing 1 wt% of polysaccharides, gelation was not sufficient even when cooled to 25 ℃, and it was difficult to maintain the gel state when the temperature of the raw material was raised. As shown in fig. 11B, particularly, when the raw material slurry containing 5 to 7 wt% of polysaccharides is once cooled and gelled, the raw material slurry does not easily return to the sol even when heated above the transition temperature, and can maintain the gel state.

As described above, the raw material slurry containing gellan gum and tamarind gum as polysaccharides has "temperature-sensitive sol-gel transition characteristics".

13-3. method (preparation of sheet and determination of menthol content)

Menthol-containing sheets were prepared using raw material slurries (see column 13-1) containing polysaccharides at various concentrations. Sheet preparation was carried out in the same manner as in example 9.

The menthol content of the sheet immediately after the production (initial menthol content) and the menthol content of the sheet stored in an accelerated environment (menthol content after the storage) were measured. The accelerated environment was the same as that described in example 1, and the menthol content was measured by the same method as in example 9. The results are shown in fig. 11C.

13-4. results (menthol content)

As shown in fig. 11C, when the polysaccharide concentration was 2 wt%, 3 wt%, 5 wt%, or 7 wt%, the initial menthol content was about 70 wt%, and the menthol content after 30 days of storage was 55 to 65 wt% (the menthol retention rate was 82 to 90%). Among them, when the polysaccharide concentration was 3% by weight and 5% by weight, the menthol content after 30 days of storage was particularly high, showing values of 65% by weight and 64% by weight, respectively.

These results show that the polysaccharide is preferably contained in the raw material slurry at a concentration of 2 to 7 wt%, more preferably 3 to 5 wt%.

[ example 14]

In this example, the effect of the blending ratio of menthol in the raw material slurry on the menthol content and the menthol yield of the menthol-containing sheet after storage was examined.

14-1. method (preparation of sheet and determination of menthol content)

Sheets containing gellan/tamarind gum were prepared using stock slurries having various menthol blend ratios. Sheet preparation was carried out in the same manner as in example 9. As the polysaccharide, gellan gum and tamarind gum were used in a weight ratio of 1: 1. The polysaccharide (a mixture of gellan gum and tamarind gum) was used in an amount of 3 parts by weight (3% by weight based on water) per 100 parts by weight of water. Menthol was added in an amount of 0.5 times, 1 time, 2.5 times, 5 times, 10 times, 15 times, or 20 times the weight of the polysaccharide in the raw material slurry, based on 3 parts by weight of the polysaccharide.

The menthol content of the sheet immediately after the production (initial menthol content) and the menthol content of the sheet stored in an accelerated environment (menthol content after the storage) were measured. The accelerated environment was the same as that described in example 1, and the menthol content was measured by the same method as in example 9. The results are shown in FIGS. 12A to 12E. In these figures, the ratio of [ 1: x ] denotes the weight ratio of polysaccharides and menthol in the raw material slurry, for example, [ 1: 5] represents that menthol is contained in the raw material slurry in an amount of 5 times by weight with respect to the polysaccharide. In these figures, "immediately after production" means immediately after production of the sheet, and "after 1 month at 50 ℃ means after 30 days of storage at 50 ℃.

14-2. results

As shown in fig. 12A, the "initial menthol content" was highest in the case of a sheet containing 5 times by weight of menthol and lowest in the case of a sheet containing 0.5 times by weight of menthol, depending on the amount of menthol added. The "menthol content after storage" is hardly reduced with respect to the initial menthol content in any menthol content. Therefore, as shown in FIG. 12B, the aroma retention rate of menthol after 30 days of storage showed a high value of 84 to 93% in any amount of the mixture. Among them, the sheet containing 2.5 times by weight of menthol showed the highest menthol fragrance retention rate.

As shown in fig. 12C, the "menthol yield" immediately after the sheet was produced showed a value of 65% at the maximum in the sheets containing 1-fold by weight and 2.5-fold by weight of menthol. The "menthol yield" after storage showed a value of 54% at the maximum in the sheets containing 1-fold and 2.5-fold weight of menthol. The "menthol yield" after storage was lower in the sheet containing 5 times by weight of menthol than in the sheet containing 2.5 times by weight of menthol, but the content (absolute amount) of menthol in the sheet was large (see fig. 12A).

Fig. 12D and 12E show the relationship between the menthol blending ratio (%) and the menthol content (%) and the relationship between the menthol blending ratio (%) and the menthol yield (%), respectively. In these figures, the menthol blending ratio (%) shows { menthol blending amount/(menthol blending amount + gellan gum blending amount) } × 100.

As shown in fig. 12D, the sheet having a menthol content of 2.5 to 5 times by weight (i.e., a menthol content of 71 to 83%) exhibited a high menthol content after storage. As shown in fig. 12E, the sheet containing 1 to 2.5 times the amount of menthol (i.e., 50 to 71% of menthol) showed a high menthol yield when stored.

From these results, it is found that the amount of menthol blended with the polysaccharide is preferably in the range of 1 to 5 times by weight, more preferably in the range of 2.5 to 5 times by weight.

Claims (10)

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 60-90 ℃ on a base material, wherein the raw material slurry contains a perfume, an emulsifier, 70-95 wt% of water, and a polysaccharide composed of gellan gum and tamarind gum, and the weight ratio of the gellan gum to the tamarind gum is in the range of 1: 1-3: 1;

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

the raw material slurry does not contain metal ions that function as a gelation promoter.

2. The method of making a flavor-containing sheet for a smoking article of claim 1, wherein the emulsifier is lecithin.

3. A tablet-containing material for a smoking article made by the method of claim 1 or 2.

4. The flavor-containing sheet for a smoking article according to claim 3, wherein the content of the flavor in the produced sheet is 45% by weight or more, and the content of the flavor in the sheet after storage at 50 ℃ for 30 days is 45% by weight or more.

5. A flavour-containing sheet for a smoking article according to claim 3, wherein the flavour is menthol.

6. The flavor-containing sheet for a smoking article according to claim 5, 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.

7. A smoking article comprising a cut tobacco, wherein the cut tobacco is incorporated with the flavor-containing sheet material for a smoking article according to claim 3 or 4.

8. A smoking article comprising a cut tobacco, wherein the cut tobacco is incorporated with the flavor-containing sheet for smoking articles according to claim 5 or 6.

9. A cigarette, comprising: a tobacco rod comprising a tobacco shred and a cigarette wrapper wrapped around the tobacco shred, wherein the cut product of the flavor-containing sheet for a smoking article according to claim 3 or 4 is blended in the tobacco shred.

10. A cigarette, comprising: a tobacco rod comprising a tobacco shred and a cigarette wrapper wrapped around the tobacco shred, wherein the tobacco shred is incorporated with a cut product of the flavor-containing sheet for smoking articles according to claim 5 or 6.