Emulsifier, emulsification method, emulsification composition, oral cleansing agent, oral cleansing composition, and oral cleansing method

Abstract

The present invention relates to an emulsifier, an emulsification composition, an oral cleansing agent, and an oral cleansing composition, each comprising at least one of theaflavin and thearubigin. The present invention also relates to an emulsification method and an oral cleansing method, each using at least one of theaflavin and thearubigin.

Description

Emulsifier, Emulsification Method, Emulsification Composition, Oral Cleanser, Oral Cleansing Composition, and Oral Cleansing Method

[0001] The present invention relates to an emulsifier, an emulsification method, an emulsification composition, an oral cleanser, an oral cleansing composition, and an oral cleansing method.

[0002] An emulsifier is used when uniformly mixing water and an oily component during food production, uniformly mixing an oily component and an aqueous component during cosmetic production, uniformly dispersing an active ingredient during pharmaceutical production, or uniformly dispersing contained components during industrial product production. In addition, an emulsifier may also be used to float dirt such as oil during cleaning.

[0003] Since emulsifiers are used in various situations in this way, it is necessary to use an appropriate emulsifier according to the situation. For example, emulsifiers used in the production of foods, cosmetics, pharmaceuticals, etc., or emulsifiers used for cleaning the body of humans, etc., especially emulsifiers used for oral cavity cleaning, are required to be safe even when ingested or touched on the skin.

[0004] In addition, research on the "reset effect of greasiness" by beverages has been conducted. So far, it has been clarified that gallate-type catechins and thearubigins among tea polyphenols have the "reset effect of greasiness" through pretreatment (Non-Patent Document 1), and as a result of analyzing the strength of the emulsifying action of beverages, it has been found that astringent polyphenols in tea-based beverages may be involved in the "reset effect of greasiness" (Non-Patent Document 2).

[0005] Grants-in-Aid for Scientific Research 2021 Achievement Report, "Molecular Scientific Verification of Food Compatibility between Astringent Beverages and Dishes," National Institute of Informatics, [Accessed December 3, 2024], Internet <URL: https: / / kaken.nii.ac.jp / report / KAKENHI-PROJECT-23K20669 / 23K206692021jisseki / > Grants-in-Aid for Scientific Research 2022 Achievement Report, "Molecular Scientific Verification of Food Compatibility between Astringent Beverages and Dishes," National Institute of Informatics, [Accessed December 3, 2024], Internet <URL: https: / / kaken.nii.ac.jp / report / KAKENHI-PROJECT-23K20669 / 23K206692022jisseki / >

[0006] As mentioned above, emulsifiers and other substances that are safe to ingest or come into contact with the skin are required.

[0007] The object of this invention is to provide a novel emulsifier, emulsification method, emulsification composition, oral rinse agent, oral rinse composition, and oral rinse method.

[0008] As a result of diligent research, the inventors discovered that tea components, particularly at least one of theaflavin and thearubigin, exhibit emulsifying and oral cleansing effects, thus completing the present invention.

[0009] In other words, the present invention is as follows: [1] An emulsifier containing at least one of theaflavin and thearubigin. [2] The emulsifier according to [1], comprising a tea extract. [3] The emulsifier according to [2], wherein the tea extract is a fermented tea extract. [4] The emulsifier according to [3], wherein the fermented tea extract is at least one selected from the group consisting of black tea extract, yellow tea extract, white tea extract, oolong tea extract and dark tea extract. [5] The emulsifier according to any one of [1] to [4], wherein the sugar content is 5% by mass or less. [6] The emulsifier according to any one of [1] to [5], further comprising a salivary component. [7] The emulsifier according to [6], wherein the salivary component is at least one selected from the group consisting of mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, carboxymethylcellulose sodium, disodium phosphate and methyl 4-hydroxybenzoate. [8] An emulsifying composition containing at least one of theaflavin and thearubigin. [9] An emulsifying method comprising forming emulsion particles using the emulsifier described in any one of [1] to [7] above or the emulsifying composition described in [8] above.

[10] An emulsifying method according to [9] above, wherein forming emulsion particles using the emulsifier described in any one of [1] to [7] above or the emulsifying composition described in [8] above comprises mixing the emulsifier described in any one of [1] to [7] above or the emulsifying composition described in [8] above with salivary components.

[11] An emulsifying method comprising mixing at least one of theaflavin and thearubigin with salivary components.

[12] The emulsification method according to

[11] , wherein the salivary component is at least one selected from the group consisting of mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, sodium carboxymethylcellulose, disodium phosphate, and methyl 4-hydroxybenzoate.

[13] The emulsification method according to [9] or

[10] , wherein the emulsified particles are fine particles.

[14] The emulsification method according to any one of [9],

[10] , and

[13] , wherein the volume average diameter of the emulsified particles is 1.10 mm or less.

[15] The emulsification method according to any one of [9],

[10] ,

[13] and

[14] above, wherein the plurality of emulsified particles consist of independent emulsified particles that are not coalesced with each other and continuous emulsified particles that are coalesced, and the ratio of independent emulsified particles is greater than the ratio of continuous emulsified particles in terms of cross-sectional area ratio.

[16] An emulsification method comprising putting either theaflavin or thearubigin into the mouth and emulsifying in the oral cavity.

[17] An emulsification method comprising putting an emulsifier containing either theaflavin or thearubigin into the mouth and emulsifying in the oral cavity.

[18] An oral rinse containing at least one of theaflavin or thearubigin.

[19] The oral rinse according to

[18] above, comprising a tea extract.

[20] The oral rinse according to

[19] above, wherein the tea extract is a fermented tea extract.

[21] The mouthwash according to

[20] , wherein the fermented tea extract is at least one selected from the group consisting of black tea extract, yellow tea extract, white tea extract, oolong tea extract, and dark tea extract.

[22] The mouthwash according to any one of

[18] to

[21] , wherein the sugar content is 5% by mass or less.

[23] The mouthwash according to any one of

[18] to

[22] , for washing oily components in the oral cavity.

[24] The mouthwash according to any one of

[18] to

[23] , wherein the washing time is less than 1 minute.

[25] A mouthwash composition containing at least one of theaflavin and thearubigin.

[26] A method of mouthwash comprising putting at least one of theaflavin and thearubigin into the mouth.

[27] A method of mouthwash comprising mixing at least one of theaflavin and thearubigin with salivary components.

[28] The oral washing method according to

[27] , wherein the salivary component is at least one selected from the group consisting of mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, sodium carboxymethylcellulose, disodium phosphate, and methyl 4-hydroxybenzoate.

[29] The oral washing method according to any one of

[26] to

[28] , for washing oily components in the oral cavity.

[30] The oral rinsing method according to any one of

[26] to

[28] above, wherein the rinsing time is less than one minute.

[0010] By mixing the emulsifier, emulsifying composition, oral rinse agent, or oral rinse composition of the present invention with water and oil, fine emulsion particles that remain stable over time are formed. The smaller the emulsion particles, the more easily they tend to flow along with the flow of the solution. Furthermore, the emulsion particles generated by mixing the emulsifier or oral rinse agent of the present invention with water and oil are less likely to adhere to surrounding solids, such as the walls of a container.

[0011] Figure 1 shows the composition of the artificial saliva used in Test Examples 0 to 5. Figure 2 is a photograph of the emulsion particles in the cuvette in Test Example 1. Figure 3 is a photograph of the emulsion particles on a glass slide in Test Example 2. Figure 4 is a photograph taken over time in Test Example 3 after introducing black tea into a cell count chamber slide containing the emulsion particles. Figure 5 is a photograph taken in Test Example 4 after resuspending the emulsion particles in the cuvette. Figure 6 shows the design of the microfluidic device used in Test Example 5. Figure 7 is a photograph of the oil droplet formation in the droplet-forming section in Evaluation 1 of Test Example 5. Figure 8 is a photograph of the oil droplet formation in the meandering section and the flow of the oil droplets through the microfluidic device in Evaluation 1 of Test Example 5. Figure 9 is a box plot graph showing the projected area of ​​the oil droplets formed in the meandering section in Evaluation 1 of Test Example 5. Figure 10 is a photograph taken in the rapidly expanding section of Test Example 5, Evaluation 2, showing the adhesion of oil droplets. Figure 11 is a bar graph showing the oil droplet adhesion rate, which is the sum of the projected areas of the attached oil droplets relative to the projected area of ​​the flow path in the observation field, based on the measurement of the projected area of ​​the attached oil droplets in Test Example 5, Evaluation 2.

[0012] The present invention will be described in detail below, but these are merely examples of preferred embodiments and are not limiting to these. The "~" in numerical ranges indicates a range that includes the numbers before and after it; for example, "0 mass% to 100 mass%" means a range that is 0 mass% or more and 100 mass% or less.

[0013] Theaflavins and thearubigins are known to be substances produced when catechins are oxidized and polymerized during the fermentation process of tea leaves (Tadashi Nakagawa; "The Color and Quality of Black Tea and the Content of Theaflavins and Thearubigins"; Journal of the Japan Society for Food Science and Technology; June 1969; Vol. 16, No. 6; pp. 266-271). The above-mentioned tea leaves include harvested leaves or stems of the tea plant (scientific name: Camellia sinensis).

[0014] The origin of at least one of the theaflavin and thearubigin used in this embodiment is not particularly limited, but may be derived from a tea extract, preferably from a fermented tea extract, or may not be derived from a tea extract. In this specification, examples of the fermented tea extract include, preferably, black tea extract, yellow tea extract, white tea extract, oolong tea extract, and dark tea extract, with black tea extract being particularly preferred. Furthermore, the origin of at least one of the theaflavin and thearubigin may be derived from natural products other than tea, or obtained by known methods such as chemical synthesis or microbial production.

[0015] In this specification, salivary components are not particularly limited as long as they are components contained in the saliva of mammals, but components contained in human saliva are particularly preferred. Any components contained in saliva may be salivary components such as components extracted from saliva, or non-salivary components that have not been extracted from saliva. Specific examples of salivary components in this specification include mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, sodium carboxymethylcellulose, disodium phosphate, and methyl 4-hydroxybenzoate.

[0016] [Emulsifier and Emulsifying Composition] The emulsifier or emulsifying composition of this embodiment contains at least one of theaflavin and thearubigin.

[0017] The emulsion particles obtained by mixing the emulsifier or emulsifying composition of this embodiment with water and oil are preferably of the oil-in-water droplet type. When the emulsion particles are of the oil-in-water droplet type, it is believed that at least one of the theaflavin and thearubigin contained in the emulsifier or emulsifying composition of this embodiment adheres to the oil droplet interface in the aqueous solution to form emulsion particles, and that emulsification occurs when these emulsion particles exist stably in the aqueous solution.

[0018] In the emulsifier or emulsifying composition of this embodiment, the total amount of at least one of theaflavin and thearubigin is preferably 0.1% to 10% by mass, and more preferably 0.2% to 5% by mass.

[0019] The emulsifier or emulsifying composition of this embodiment preferably contains a tea extract, and more preferably the tea extract is a fermented tea extract. In the emulsifier or emulsifying composition of this embodiment, the amount of tea extract is preferably 10% to 99% by mass, and more preferably 20% to 95% by mass.

[0020] In addition, the emulsifier or emulsifying composition of this embodiment preferably contains 5% by mass or less of sugars, more preferably 1% by mass or less, and is particularly preferably sugar-free.

[0021] Furthermore, the emulsifier or emulsifying composition of this embodiment may contain salivary components. When the emulsified particles obtained by mixing the emulsifier or emulsifying composition of this embodiment with water and oil are of the oil-in-water droplet type, it is believed that at least one of the theaflavin and thearubigin contained in the emulsifier or emulsifying composition of this embodiment and the salivary components adhere to the oil interface in the aqueous solution, thereby forming finer and more stable emulsified particles over time.

[0022] In the emulsifier or emulsifying composition of this embodiment, the saliva component consists of one or more components, preferably 0.01% to 20% by mass, and more preferably 0.1% to 10% by mass.

[0023] The emulsifier or emulsifying composition of this embodiment preferably contains water. In the emulsifier or emulsifying composition of this embodiment, the amount of water is preferably 1% to 90% by mass, and more preferably 5% to 80% by mass.

[0024] The emulsifier or emulsifying composition of this embodiment may contain, in addition to the above-mentioned components, stabilizers, preservatives, antioxidants, thickeners, pH adjusters, fragrances, or colorants, for example, ascorbic acid.

[0025] Examples of the emulsifier or emulsifying composition in this embodiment include liquid, powder, paste, solid, aerosol, or gel.

[0026] The emulsifier or emulsifying composition of this embodiment can be used for cleaning. In this specification, examples of cleaning include the removal of oil stains, the removal of cosmetic residues, the cleaning of industrial machinery, the cleaning of food processing equipment, the cleaning of automobiles, or the cleaning of medical devices.

[0027] The emulsifier or emulsifying composition of this embodiment can also be used to uniformly mix substances that are difficult to mix. Examples of such uses described herein include, for example, uniformly mixing water and oily components in the manufacture of foods such as ice cream, mayonnaise, chocolate, or bread; uniformly mixing oily components and aqueous components in the manufacture of cosmetics such as creams, lotions, makeup products, or shampoos; uniformly dispersing active ingredients in the manufacture of pharmaceuticals such as ointments or oral suspensions; and uniformly dispersing contained components in the manufacture of industrial products such as paints, inks, pesticides, or detergents.

[0028] In this specification, there are no particular limitations on oily components, as long as they are naturally derived or non-naturally derived oily components, and they may be a single component or a mixture of two or more components. Examples of oily components include vegetable oils such as salad oil, canola oil, rapeseed oil, corn oil, rice oil, sesame oil, perilla oil, linseed oil, coconut oil, almond oil, moringa oil, peanut oil, camellia oil, coconut oil, olive oil, or margarine; animal oils such as beef tallow, chicken tallow, pork tallow, horse tallow, bone tallow, sebum, butter, tallow, or lard; fish oils such as fish oil, liver oil, and whale tallow; processed oils such as squalane oil; mineral oils such as petrolatum; and synthetic oils.

[0029] There are no particular limitations on the method used for emulsification with the emulsifier or emulsifying composition of this embodiment, but examples include methods for forming droplets mechanically or by shearing. For mechanical methods, for example, a propeller mixer or homogenizer can be used, and for shearing methods, for example, a homogenizer or a microchannel (microfluidic device) can be used.

[0030] Furthermore, the state of the droplets formed by emulsification can be evaluated using methods such as observation, light transmittance, and light scattering. Temperature control and centrifugation can also be appropriately combined during the evaluation process.

[0031] Furthermore, the emulsifier or emulsifying composition of this embodiment has the effect of reducing or eliminating discomfort, such as removing oily components from the mouth and leaving a refreshing feeling, when ingested orally during or after a meal containing a lot of oily components. The emulsifier of this embodiment may be ingested directly or used as an additive to impart emulsifying properties to the emulsifying composition. After ingesting the emulsifier or emulsifying composition of this embodiment, it may be spat out or swallowed. As mentioned above, since theaflavins and thearubigins are components also found in black tea, theaflavins and thearubigins are safe to swallow.

[0032] When ingesting the emulsifier or emulsifying composition of this embodiment, the route of ingestion is not particularly limited, but oral ingestion, such as in the mouth, is preferred.

[0033] Examples of the emulsifier or emulsifying composition of this embodiment for oral administration include liquid forms such as aqueous solutions, extracts, suspensions, syrups, elixirs, emulsions, or dispersions; semi-liquid forms such as creams or pastes; and solid forms such as powders, granules, capsules, sachets, tablets, boluses, or lozenges.

[0034] When the emulsifier or emulsifying composition of this embodiment is taken orally during or after a meal, specific examples of the emulsifier's form include mouthwash or oral spray. Examples of the emulsifying composition include food and beverages, toothpaste, toothpaste gel, toothpaste paste, gum, tablets, throat lozenges, oral gel, oral moisturizer, oral disinfectant, or oral rinse.

[0035] The emulsifier of this embodiment may be manufactured using only at least one of theaflavin and thearubigin. Alternatively, the emulsifier and emulsifying composition of this embodiment may be manufactured by mixing at least one of theaflavin and thearubigin with the above-mentioned components using known methods.

[0036] [Emulsification Method] The emulsification method of this embodiment includes forming emulsion particles using the emulsifier or emulsifying composition of this embodiment described above. In the emulsification method of this embodiment, it is preferable to form emulsion particles by mixing the emulsifier or emulsifying composition of this embodiment with water and oil.

[0037] The emulsification method of this embodiment preferably includes mixing the emulsifier or emulsifying composition of this embodiment with salivary components. When emulsifying in the oral cavity, the salivary components may be salivary components already contained in the emulsifier or emulsifying composition of this embodiment, or salivary components contained in saliva in the oral cavity. Furthermore, the emulsification method of this embodiment may also include mixing at least one of theaflavin and thearubigin with salivary components.

[0038] In this specification, the emulsion particles are preferably fine particles, and more specifically, they are preferably 1.10 mm or less in volume average diameter. When the generated emulsion particles are fine particles, they tend to be easily carried away along with the flow of the solution. The volume average diameter of the emulsion particles can be measured by known methods, but for example, it can be determined by sampling a portion of the emulsion particles and observing them under a microscope on a glass slide. Specifically, the volume average diameter is a value calculated by measuring at least 40 emulsion particles with diameters in the range of 100 μm to 2000 μm.

[0039] Furthermore, the plurality of emulsion particles consist of independent emulsion particles that are not coalesced with each other and continuous emulsion particles that are coalesced with each other, and it is preferable that the ratio of independent emulsion particles is greater than the ratio of continuous emulsion particles in terms of cross-sectional area ratio. More preferably, the cross-sectional area ratio of independent emulsion particles:continuous emulsion particles = 99:1 to 90:10. Moreover, the emulsion particles obtained by the emulsification method of this embodiment are less likely to coalesce with each other and can maintain a fine particle state for a long time compared to emulsion particles obtained without using the emulsifier or emulsifying composition of this embodiment. In other words, the emulsion particles obtained by the emulsification method of this embodiment can maintain the above-mentioned cross-sectional area ratio within a certain range for a long time. The range of the cross-sectional area ratio that can be maintained is preferably independent emulsion particles:continuous emulsion particles = 99:1 to 90:10. The time for which the cross-sectional area ratio can be maintained is preferably 5 seconds to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 1 minute. The above cross-sectional area can also be measured in the same way as the projected area in the embodiment described later.

[0040] The emulsification method of this embodiment can be used during washing or when uniformly mixing substances that are difficult to mix. Specific examples of such uses are as described above.

[0041] The emulsification method of this embodiment may include putting the emulsifier or emulsifying composition of this embodiment into the mouth and emulsifying it in the oral cavity. Alternatively, the emulsification method of this embodiment may include putting either theaflavin or thearubigin into the mouth and emulsifying it in the oral cavity.

[0042] As one aspect of the emulsification method of the present embodiment, during or after a meal with a large amount of oily components, by putting the emulsifier or emulsifying composition of the present embodiment in the mouth, or by putting either one of theaflavin and thearubigin in the mouth, it is possible to reduce or eliminate discomfort such as removing the oily components in the oral cavity and making it refreshing. After putting either one of theaflavin and thearubigin in the mouth, actions such as rinsing, gargling, or mouthwashing the oral cavity may be performed. After the emulsification method of the present embodiment, a mixture containing either one of theaflavin and thearubigin, an oily component, etc. may be spat out or swallowed from the mouth.

[0043] [Oral Cleanser and Oral Cleansing Composition] The oral cleanser or oral cleansing composition of the present embodiment contains at least one of theaflavin and thearubigin. As described above, due to the action of at least one of theaflavin and thearubigin, the oily components or fat present in the oral cavity after a meal, etc., are dispersed in a solution such as water by putting the oral cleanser or oral cleansing composition of the present embodiment in the mouth. Also, at least one of theaflavin and thearubigin suppresses the reattachment of the oily components or fat dispersed in a solution such as water to the surface of tissues in the oral cavity such as teeth or tongue. Further, since the emulsified particles obtained by at least one of theaflavin and thearubigin are small, they are considered to be easily washed away in the solution and easily discharged outside the oral cavity.

[0044] The oral cleanser and oral cleansing composition of the present embodiment are preferably for cleaning oily components.

[0045] In the oral cleanser or oral cleansing composition of the present embodiment, the total amount of at least one of theaflavin and thearubigin is preferably 0.1% by mass to 10% by mass, more preferably 0.2% by mass to 5% by mass.

[0046] The oral cleansing agent or oral cleansing composition of the present embodiment preferably contains a tea extract, and more preferably the tea extract is a fermented tea extract. In the oral cleansing agent or oral cleansing composition of the present embodiment, the tea extract is preferably 1% by mass to 20% by mass, and more preferably 5% by mass to 15% by mass.

[0047] In addition, the oral cleansing agent or oral cleansing composition of the present embodiment preferably has a sugar content of 5% by mass or less, more preferably 1% by mass or less, and particularly preferably contains no sugar at all.

[0048] The oral cleansing agent or oral cleansing composition of the present embodiment may contain a saliva component. In the oral cleansing agent or oral cleansing composition of the present embodiment, the saliva component is preferably 0.01% by mass to 20% by mass, and more preferably 0.1% by mass to 10% by mass.

[0049] The oral cleansing agent or oral cleansing composition of the present embodiment preferably contains water. In the oral cleansing agent or oral cleansing composition of the present embodiment, the water is preferably 1% by mass to 90% by mass, and more preferably 5% by mass to 80% by mass.

[0050] In addition to the above-mentioned components, the oral cleansing agent or oral cleansing composition of the present embodiment may contain a thickening agent, an abrasive, a preservative, a bactericide, an antibacterial agent, an anti-inflammatory agent, a glucosyltransferase (GTase) inhibitor, a plaque inhibitor, a hypersensitivity inhibitor, a dental calculus preventive, a dentin strengthening / remineralizing agent, an antihistamine, a local anesthetic, a blood circulation promoter, a humectant, an excipient, a fragrance, a sweetening agent, a pigment, a deodorant, a surfactant, a solvent, a pH adjuster, a stabilizer, an antioxidant, or a coloring agent, etc.

[0051] The oral cleansing agent or oral cleansing composition of the present embodiment preferably has a viscosity at 25°C of 1 to 5 mPa·s.

[0052] The oral cleansing agent or oral cleansing composition of the present embodiment preferably has a pH at 25°C of 3 to 7.

[0053] The mouthwash of this embodiment may be ingested directly into the mouth, or it may be used as an additive to impart emulsifying properties to a mouthwash composition. After ingesting the mouthwash or mouthwash composition of this embodiment into the mouth, it may be spat out or swallowed.

[0054] The oral rinse agent or oral rinse composition of this embodiment is not particularly limited in terms of the route of intake, as long as the desired effects of the present invention are obtained, but oral intake, such as in the oral cavity, is preferred.

[0055] Examples of the oral rinse agent or oral rinse composition of this embodiment for oral intake include liquid forms such as aqueous solutions, extracts, suspensions, syrups, elixirs, emulsions, or dispersions; semi-liquid forms such as creams or pastes; and solid forms such as powders, granules, capsules, sachets, tablets, boluses, or lozenges.

[0056] Examples of oral cleansing agents include mouthwash or oral spray. Examples of oral cleansing compositions include food and beverages, toothpaste, toothpaste gel, toothpaste paste, gum, tablets, or throat lozenges.

[0057] The timing for ingesting the oral rinse agent or oral rinse composition of this embodiment is not particularly limited, but it is preferable to ingest it into the mouth during or after a meal that contains a lot of oily components.

[0058] When using the oral rinse agent or oral rinse composition of this embodiment, the washing time is preferably less than 1 minute, more preferably within 30 seconds.

[0059] The oral rinse according to this embodiment may be manufactured using at least one of theaflavin and thearubigin. Alternatively, the oral rinse or oral rinse composition according to this embodiment may be manufactured by mixing at least one of theaflavin and thearubigin with the above-mentioned components.

[0060] [Oral Cleansing Method] The oral cleansing method of this embodiment includes putting at least one of theaflavin and thearubigin into the mouth. The oral cleansing method of this embodiment preferably involves putting the oral cleansing agent or oral cleansing composition of this embodiment described above into the mouth.

[0061] In the oral rinsing method of this embodiment, it is preferable to mix at least one of theaflavin and thearubigin with a salivary component. Furthermore, in the oral rinsing method of this embodiment, it is preferable to mix the oral rinsing agent or oral rinsing composition of this embodiment described above with a salivary component. These mixing is preferably performed in the oral cavity. In the oral rinsing method of this embodiment, the salivary component may be a salivary component already contained in the emulsifier or emulsifying composition of this embodiment, or it may be a salivary component contained in saliva in the oral cavity.

[0062] The oral cleaning method of this embodiment is preferably a method for cleaning oily components in the oral cavity.

[0063] The timing of performing the oral rinsing method of this embodiment is not particularly limited, but for example, the mouth can be rinsed by holding at least one of theaflavin and thearubigin in the mouth during or after a meal containing a lot of oily components. After holding either theaflavin or thearubigin in the mouth, the mouth may be rinsed, gargled, or otherwise used. After the oral rinsing method of this embodiment, either theaflavin or thearubigin, or a mixture containing oily components, may be spat out of the mouth or swallowed.

[0064] In the oral rinsing method of this embodiment, the rinsing time is preferably less than 1 minute, and more preferably within 30 seconds.

[0065] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention.

[0066] [Test Example 0: Observation of Emulsification with and without Artificial Saliva] Since the emulsifier, emulsifying composition, oral rinse, and oral rinse composition of this embodiment may be used in the oral cavity, the inventors considered it necessary to observe the emulsifying action in an environment that simulates the oral cavity. Therefore, they prepared a solution containing theaflavin and thearubigin, water, and oil, with and without the addition of artificial saliva, and observed the emulsification process according to the following procedure.

[0067] As samples, commercially available drinking water, black tea, and green tea were prepared. As oil, edible olive oil (manufactured by J-Oil Mills Co., Ltd.) was prepared. As artificial saliva, Artificial Human Saliva (manufactured by BIOCHEMAZONE Inc.) was prepared. The composition of Artificial Human Saliva is shown in Figure 1.

[0068] 1.6 mL of sample and 0.2 mL of oil were placed in a container. For the sample, one of the commercially available beverages mentioned above (water, black tea, or green tea) was used. In the case where artificial saliva was included, 0.2 mL of artificial saliva was added to the container; in the case where artificial saliva was not included, 0.2 mL of water was added to the container and stirred. After stirring and emulsification, the mixture was left to stand for 10 minutes before being visually observed.

[0069] When water was used as the sample, the amount of emulsified particles was clearly higher in the sample containing artificial saliva than in the sample without artificial saliva. However, in the samples using black tea or green tea, it was not possible to clearly determine the difference in the amount of emulsified particles or the emulsification process with or without artificial saliva based on visual observation. Since it was observed that the presence of artificial saliva affected the emulsification process when water was used as the sample, subsequent experiments included the use of artificial saliva.

[0070] Green tea contains polyphenols such as (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), as well as their thermal isomers (+)-catechin (C), (-)-gallocatechin (GC), (-)-catechin gallate (CG), and (-)-gallocatechin gallate (GCG). However, unlike black tea, it is known to contain almost no theaflavins and thearubigins (Journal of Food Science, 2006, Vol. 70, No. 9, C550-C559).

[0071] [Test Example 1: Mixing of Various Beverages and Oils] Various beverages and oils were mixed according to the following procedure, and the results after mixing were observed. The same samples, oils, and artificial saliva were used as in Test Example 0. In the following experiments, black tea was used as the sample in the example, green tea in the comparative example, and drinking water in the reference example.

[0072] The above sample, artificial saliva, and oil were added to a polymethyl methacrylate (PMMA) cuvette (12.5 mm x 12.5 mm x 45 mm) in a ratio of sample:saliva:oil = 7:1:2 (v / v) to a total volume of 1 mL. A unit NS-310E3 (Microtech Nichion Co., Ltd.) equipped with a shaft (NS-7A, dimensions: 7.0φ x 100 mm) was used for stirring. The unit's dial was set to 30 and stirred for 1 minute. After stirring, it was allowed to stand for 5 minutes to allow the emulsion particles to float. After 5 minutes, the cuvette was photographed with an iPhone® to observe the appearance of the floating emulsion particles inside the cuvette. The photograph is shown in Figure 2.

[0073] Before stirring, the sample and artificial saliva were in the lower layer, and the oil was in the upper layer, resulting in a two-layer separation. Stirring generated emulsified particles, and most of these particles floated to the surface within about one minute. Five minutes after the end of stirring, the floating emulsified particles were in a state before they had coalesced.

[0074] As shown in Figure 2, focusing on the interface between the emulsified particles and the continuous phase, it can be seen that the emulsified particles were small in the example using black tea, while they were large in the comparative example using green tea. Furthermore, in the reference example using drinking water, it can be seen that many of the emulsified particles were coalesced.

[0075] [Test Example 2: Measurement of the Volume-Average Diameter of Emulsified Particles] A portion of the emulsion particles that floated in the examples, comparative examples, and reference examples prepared in Test Example 1 were sampled and observed under a microscope on a glass slide. During observation, at least 40 emulsion particles with diameters in the range of 100 μm to 2000 μm were measured, and the volume-average diameter was calculated.

[0076] Figure 3 shows a photograph of the emulsion particles on a glass slide. Table 1 shows the calculated volume-average diameter of the emulsion particles.

[0077]

[0078] Figure 3 shows that the number of emulsified particles per unit area on the slide glass was higher in the example using black tea than in the comparative example using green tea. This suggests that when using black tea, the emulsified particles are less likely to coalesce on the slide glass than when using green tea. Furthermore, as shown in Table 1, the volume-average diameter of the emulsified particles in the example using black tea was smaller than in the comparative example using green tea. In the reference example using drinking water, the emulsified particles coalesced quickly and could not be observed as floating emulsified particles. Therefore, the volume-average diameter of the emulsified particles could not be measured.

[0079] Based on the results shown in Test Examples 1 and 2, the stability of emulsified particles produced using black tea is considered to be relatively higher than that of emulsified particles produced using drinking water or green tea.

[0080] [Test Example 3: Observation of the Behavior of Emulsified Particles] A 2.5 μL sample was taken from the floating emulsion particles prepared using the same procedure as in Test Example 1, and sealed in a cell count chamber slide (Countess, Invitrogen) that had been pre-filled with 10 μL of black tea. Then, 50 μL of black tea was introduced into the cell count chamber slide by capillary effect (t=0 ms), and the behavior of the emulsion particles was observed over time. An OLYMPUS SZX10 (manufactured by Olympus Corporation) was used for observation. The time when the black tea was introduced into the cell count chamber slide was defined as t=0 ms, and photographs taken at t=0 ms, 96 ms, 510 ms, and 1211 ms are shown in Figure 4.

[0081] Figure 4 shows that smaller emulsion particles are carried away faster along the solution flow, while larger particles are carried away more slowly. As shown in Test Example 2, the volume-average diameter was smaller in the example using black tea than in the comparative example using green tea, suggesting that emulsion particles produced using black tea, which have a smaller particle size, are more easily carried away along the water flow.

[0082] [Test Example 4: Observation of Adhesion of Emulsified Particles to the Surrounding Solid] After generating emulsion particles using the same procedure as in the example, comparative example, and reference example of Test Example 1, the mixture was allowed to stand for 5 minutes after stirring was complete. 1 mL of the continuous phase, excluding the floating emulsion particles, was collected by pipetting and removed from the cuvette. Then, 1 mL of pure water was added to the cuvette. This collection and resuspension operation was performed slowly using a Pipetman P1000 (Gilson) set to 1 mL, with the tip of the Pipetman placed in the center of the bottom of the cuvette. The appearance after resuspension was photographed with an iPhone®. The photograph is shown in Figure 5.

[0083] Figure 5 shows that in the example using black tea, adhesion of emulsion particles to the container wall was suppressed, whereas in the reference example using drinking water and the comparative example using green tea, emulsion particles adhered to the container wall. Generally, the presence of large emulsion particles promotes coalescence among them. Therefore, in the comparative example using green tea, it is thought that the larger size of the emulsion particles led to increased coalescence among them, resulting in the formation of coarser particles that adhered to the container wall. In the example, it is thought that the theaflavins and thearubigins contained in black tea adsorbed to the interface of the emulsion particles and adhered to the container, thereby suppressing adhesion of emulsion particles to the container wall.

[0084] [Test Example 5: Evaluation of Emulsified Particle Formation and Adhesion using a Microfluidic Device] In order to observe in more detail the emulsifying action of the emulsifier, emulsifying composition, oral rinse agent, and oral rinse composition of this embodiment, the formation and adhesion of emulsion particles were evaluated using a microfluidic device.

[0085] In this study, a microfluidic device made of polydimethylsiloxane (PDMS) with a two-stage depth channel structure was fabricated and used for evaluation. The PDMS-based microdevice channel device was fabricated based on the content of a previously published paper (Microsystems & nanoengineering, Vol. 3, No. 1, pp. 1-9 (2017)).

[0086] Furthermore, the microfluidic device used was designed based on a previously published study (Food Hydrocoloids, Vol. 70, pp. 96-104 (2017)) evaluating the stability of oil droplets within the device. The design diagram is shown in Figure 6. In the design diagram, the depth of the parts indicated by thick lines was approximately 120 μm, and the depth of the parts indicated by solid lines was approximately 45 μm. The width of the channel indicated by thick lines was approximately 500 μm, and the width of the parts indicated by solid lines was approximately 100 μm.

[0087] The microfluidic device consists of the following five elements: (1) Inlet (corresponding to the two black circles located on the left in Figure 6): The inlet is an inlet for introducing the continuous phase (corresponding to aqueous samples) and the dispersed phase (corresponding to oil-based samples). (2) Droplet formation section: In the droplet formation section, the continuous phase and the dispersed phase merge within a flow-focusing structure to promote oil droplet formation. (3) Meaning section: The meandering section is a curved channel where the formed oil droplets move and are stabilized. Here, phenomena such as the adsorption of components that stabilize the oil droplet interface and the delayed formation of oil droplets can be observed. However, it is not always necessary to observe oil droplets in the curved channel section; oil droplets flowing in the straight channels that make up the meandering section may also be the target of observation. (4) Rapid expansion section: The rapid expansion section has a wide expansion structure and is used to observe and photograph the adhesion state of oil droplets to each other, or between oil droplets and the inside of the tube. The upper part of the rapid expansion section has markings at 5 mm intervals from the beginning of the rapid expansion section. Note that the rapidly expanding section is the part indicated by the thick line in Figure 6, and the width of the flow path within the rapidly expanding section is constant. (5) Outlet section (corresponding to the single black circle located on the right in Figure 6): The outlet section is the outlet for discharging the treated liquid.

[0088] The formation, flow, and adhesion states of oil droplets were evaluated using the fabricated microfluidic devices. Oleic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., purity 65.0% or higher) was used as the oil-based sample. For the aqueous sample, a mixture of polyphenols, ascorbic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and artificial saliva (Artificial Human Saliva, manufactured by BIOCHEMAZONE) was used. The polyphenols used were Catechin Mixture from Green Tea (purity 80% or higher, manufactured by Fujifilm Wako Pure Chemical Industries, hereinafter abbreviated as: green tea polyphenols) or Tea extract from Camellia sinensis analytical standard, purity 80% or higher (theaflavins (theaflavin and theaflavin gallates) base, manufactured by Sigma Aldrich, hereinafter abbreviated as: black tea polyphenols). Green tea polyphenols were crude catechin extracts contained in green tea, and were a mixture of epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (Wako Reagents Bulletin, Vol. 68 No. 4, p. 16 (2000)). Black tea polyphenols were a mixture of theaflavins (theaflavins and theaflavins with galloyl groups).

[0089] The aqueous mixed samples were prepared as follows. First, each polyphenol and ascorbic acid were dissolved in ultrapure water (resistivity 18.2 MΩ·cm) to final concentrations of 300 and 100 ppm, respectively. If the polyphenols were difficult to dissolve, they were treated with an ultrasonic generator (US-1, SND Corporation). The dissolved samples were stored at 4°C until immediately before use. The samples were also subjected to the following evaluations within 24 hours of preparation. Next, immediately before evaluation with a microfluidic device, samples 1 to 3 shown in Table 2 below were prepared. Then, one of samples 1 to 3 was mixed with artificial saliva in a ratio of 7:1 (v / v). In this specification, ppm means mg / L.

[0090]

[0091] The dispersed and continuous phases were introduced into the fluid pathway using a syringe pump and a 2.5 mL syringe (Terumo Corporation). The flow rates were set to 2 μL / min for the dispersed phase and 50 μL / min for the continuous phase. The syringe and device were connected by a tube during introduction. At the time of introduction, the temperature of each sample was approximately 25°C. A microscope (IX71, Olympus Corporation) and a digital microscope camera (DP80, Olympus Corporation) were used for observation, and both video and still images were acquired. The formation and adhesion of emulsion particles were evaluated by observing and analyzing the droplet-forming, meandering, and rapidly expanding sections of the microfluidic device. ImageJ (v1.54g, National Institutes of Health) was used for image analysis.

[0092] (Evaluation 1) Oil droplet formation Evaluation 1 confirmed the formation of oil droplets in the droplet-forming section (Figure 7). Furthermore, oil droplet formation in the meandering section was confirmed (Figure 8), and the projected area of ​​the oil droplets was calculated (Figure 9). Figure 7 is a photograph showing the oil droplet formation in the droplet-forming section. Figure 8 is a photograph showing the oil droplet formation in the meandering section and the flow of the oil droplets through the microfluidic device. As shown in Figure 7, samples 2 and 3 formed oil droplets in the droplet-forming section. On the other hand, sample 1 did not form oil droplets in the droplet-forming section as shown in Figure 7, but formed oil droplets in the meandering section as shown in Figure 8. Note that in Figure 7, the liquid was flowed from left to right.

[0093] The projected area of ​​the oil droplets formed by each sample was evaluated. In the droplet-forming area, no oil droplet formation was observed for sample 1. Therefore, the median projected area of ​​the oil droplets in the meandering section where oil droplet formation was observed for all samples was calculated, and multiple comparisons were performed using the Mann-Whitney U test (Holm corrected). Box plots were created using ChatGTP 5 Pro (OpenAI). Figure 9 shows a graph of the projected area of ​​oil droplets formed in the meandering section, represented by a box plot.

[0094] In Figure 9, the bottom of the box represents the 25th percentile data point, the horizontal line inside the box represents the 50th percentile data point (median), and the top of the box represents the 75th percentile data point. The upper and lower whiskers represent the maximum and minimum values ​​of the sample, respectively. Points outside the upper or lower whisker indicate outliers. Compared to sample 1, the projected area of ​​oil droplets formed by sample 2 or sample 3 was significantly smaller. Furthermore, the projected area of ​​oil droplets formed by sample 2 was significantly smaller than that of sample 3 (p < 0.0001 ****).

[0095] These results, as shown in samples 2 and 3, indicate that tea-derived polyphenols have the ability to form oil droplets under conditions involving strong shear forces, and these droplets maintained their spherical shape and dispersed and flowed in the continuous phase. Furthermore, as can be seen by comparing samples 2 and 3, the size of the oil droplets changed when the type of polyphenol changed.

[0096] (Evaluation 2) In Evaluation 2 of the suppression of oil droplet adhesion, the adhesion status of oil droplets was evaluated at a point 25 mm from the starting point of the rapidly expanding section. Figure 10 is a photograph taken of the oil droplet adhesion in the rapidly expanding section, showing the state immediately after the start of observation and around 5 seconds after the start of observation for each sample. After comparing the state immediately after the start and 5 seconds later, oil droplets that did not flow are indicated by arrows. In Figure 10, the liquid was made to flow from left to right. It was confirmed that there were many oil droplets that did not flow in Sample 1 and Sample 2, indicating that oil droplets adhered to the entire observation field, but in Sample 3 there were few oil droplets that did not flow, indicating that the adhesion of oil droplets was relatively low. Figure 11 is a bar graph in which the projected area of ​​the attached oil droplets was measured using ImageJ, and the total projected area of ​​the attached oil droplets relative to the projected area of ​​the flow path in the observation field is expressed as the oil droplet adhesion rate. The oil droplet adhesion rates to the flow path wall surface were 35.2%, 24.8%, and 3.5% for Sample 1, Sample 2, and Sample 3, respectively. These results indicate that the low rate of oil droplet adhesion to the channel wall in Sample 3 demonstrates that black tea polyphenols suppress the adhesion of oil droplets to the channel wall.

[0097] (Overall Evaluation) From the results obtained in Evaluation 1 and Evaluation 2, it was found that when a sample containing polyphenols derived from black tea was used as the continuous phase and oleic acid as the dispersed phase, oleic acid oil droplets formed and flowed, and it was shown to be particularly excellent in its ability to suppress the adhesion of oil droplets. Specifically, in the evaluation using a microfluidic device that mimicked the continuous phase formed in the oral cavity containing artificial saliva, it was shown that the components contained in Sample 3 formed stable and fine emulsion particles over time. Subsequently, it was shown that the smaller the emulsion particles, the more easily they tended to flow along with the flow of the solution. Furthermore, it was shown that the adhesion of oil droplets to the container wall and other surfaces was suppressed with Sample 3.

[0098] It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0099] This application is based on the U.S. provisional application filed on November 6, 2024 (Application No.: 63 / 717,040) and the U.S. provisional application filed on December 10, 2024 (Application No.: 63 / 730,184), the contents of which are incorporated herein by reference.

Claims

1. An emulsifier containing at least one of theaflavin and thearubigin.

2. The emulsifier according to claim 1, comprising a tea extract.

3. The emulsifier according to claim 2, wherein the tea extract is a fermented tea extract.

4. The emulsifier according to claim 3, wherein the fermented tea extract is at least one selected from the group consisting of black tea extract, yellow tea extract, white tea extract, oolong tea extract, and dark tea extract.

5. An emulsifier according to any one of claims 1 to 4, wherein the sugar content is 5% by mass or less.

6. The emulsifier according to any one of claims 1 to 5, further containing saliva components.

7. The emulsifier according to claim 6, wherein the salivary component is at least one selected from the group consisting of mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, sodium carboxymethylcellulose, disodium phosphate, and methyl 4-hydroxybenzoate.

8. An emulsifying composition containing at least one of theaflavin and thearubigin.

9. An emulsifying method comprising forming emulsified particles using an emulsifier according to any one of claims 1 to 7 or an emulsifying composition according to claim 8.

10. The emulsification method according to claim 9, wherein forming emulsified particles using the emulsifier according to any one of claims 1 to 7 or the emulsifying composition according to claim 8 comprises mixing the emulsifier according to any one of claims 1 to 7 or the emulsifying composition according to claim 8 with saliva components.

11. An emulsification method comprising mixing at least one of theaflavin and thearubigin with a salivary component.

12. The emulsification method according to claim 11, wherein the salivary component is at least one selected from the group consisting of mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, sodium carboxymethylcellulose, disodium phosphate, and methyl 4-hydroxybenzoate.

13. The emulsification method according to claim 9 or 10, wherein the emulsified particles are fine particles.

14. The emulsification method according to any one of claims 9, 10, and 13, wherein the volume average diameter of the emulsified particles is 1.10 mm or less.

15. The emulsification method according to any one of claims 9, 10, 13, and 14, wherein the plurality of emulsified particles consist of independent emulsified particles that are not coalesced with each other and continuous emulsified particles that are coalesced with each other, and the ratio of independent emulsified particles is greater than the ratio of continuous emulsified particles in terms of cross-sectional area.

16. An emulsification method comprising placing either theaflavin or thearubigin in the mouth and emulsifying it in the oral cavity.

17. An emulsification method comprising putting an emulsifier containing either theaflavin or thearubigin into the mouth and emulsifying it in the oral cavity.

18. An oral rinse containing at least one of theaflavin and thearubigin.

19. The oral rinse according to claim 18, comprising a tea extract.

20. The oral rinse according to claim 19, wherein the tea extract is a fermented tea extract.

21. The oral rinse according to claim 20, wherein the fermented tea extract is at least one selected from the group consisting of black tea extract, yellow tea extract, white tea extract, oolong tea extract, and dark tea extract.

22. The oral rinse according to any one of claims 18 to 21, wherein the sugar content is 5% by mass or less.

23. An oral cleanser according to any one of claims 18 to 22, for cleaning oily components in the oral cavity.

24. An oral rinse according to any one of claims 18 to 23, wherein the washing time is less than one minute.

25. A composition for oral rinsing containing at least one of theaflavin and thearubigin.

26. A method for oral rinsing, comprising placing at least one of theaflavin and thearubigin in the mouth.

27. A method for oral rinsing, comprising mixing at least one of theaflavin and thearubigin with a salivary component.

28. The oral rinsing method according to claim 27, wherein the salivary component is at least one selected from the group consisting of mucin, amylase, lysozyme, potassium chloride, potassium phosphate, sodium chloride, calcium chloride, magnesium chloride, sodium carboxymethylcellulose, disodium phosphate, and methyl 4-hydroxybenzoate.

29. A method for cleaning the oral cavity according to any one of claims 26 to 28, for cleaning oily components in the oral cavity.

30. The oral cleaning method according to any one of claims 26 to 28, wherein the cleaning time is less than one minute.

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