JP2021042290A - Aqueous solution for aroma diffuser - Google Patents

Abstract

To provide a method for producing an aqueous solution for aroma diffusers that contain a flavor component derived from black tea leaves, while having the same flavor as that felt when drinking black tea but having no discomfort flavors.SOLUTION: A method for producing an aqueous solution for aroma diffusers includes the steps of: conducting extraction of black tea leaves with water; subjecting the resultant extract to decompression distillation and collecting the evaporation matter as flavor water; and adjusting the pH of the collected flavor water to 5.0-6.5.SELECTED DRAWING: None

Description

The present invention relates to a method for stabilizing the aroma quality of an aqueous solution for an aroma diffuser derived from black tea leaves, and the present invention relates to the aqueous solution and a method for producing the same.

Aromatherapy using essential oils derived from plants has spread under the initiative of essential oil companies and the beauty industry. It is a kind of relaxation method as well as a sensory therapy that heals the body and mind by smelling the scent of essential oils, a hobby and beauty method that purely enjoys the scent. , Is gaining popularity mainly among women.
Recently, it is known that using scents at hotels and event venues has the effect of improving the impression of customers and extending the length of stay, and the business of space production using such scents will be in the future. Is also expected to grow.
As the scent component, essential oils derived from plants and fragrances obtained by chemical synthesis are used, but from the viewpoint of safety and health, naturally derived compositions having eating experience are attracting attention.

Linalool, geraniol, cis jasmon, linalool oxide, etc. contained in tea leaves have autonomic nerves such as anti-stress action (Patent Document 1, Non-Patent Document 1) and action to improve deterioration of blood circulation (Patent Document 2). It is known to have a regulating effect. In fact, tea time when drinking black tea is said to have a calming and soothing effect. It is considered that the aroma component contained in black tea contributes to a part of such action, but the action is temporary and black tea is to effectively enjoy such action for a long period of time. It is practically difficult to continue drinking. In addition, caffeine contained in black tea is known to have an excitatory effect and a wakefulness effect, and it is also regarded as a problem that it causes insomnia (Non-Patent Document 2). On the other hand, it is not realistic in terms of efficiency and hygiene to diffuse the black tea extract itself into the living environment for the purpose of diffusing the aroma of black tea.

Therefore, in order to effectively contact the aroma derived from black tea leaves, it is effective to use an aroma diffuser capable of diffusing only the aroma component into the living space. Therefore, an aqueous solution containing an aroma component derived from black tea leaves, which is suitable for use in an aroma diffuser, is required.

Generally, steam distillation, squeezing, and solvent extraction methods are used as methods for recovering aroma components from plant materials. Especially in the field of food flavors, the steam distillation method is used because of its superiority in terms of efficiency. Often adopted. For example, a method has been proposed in which an aroma component obtained by steam-distilling tea leaves in the process of producing instant tea is mixed with a tea leaf extract (Patent Document 3). In addition, the steam distillation method has a drawback of heat distillation odor, and as a countermeasure, the distillate obtained by steam distillation of teas is brought into contact with tea leaves, and the distillate generated during steam distillation is unpleasant. A method for improving aroma for removing a heat-distilled odor has been proposed (Patent Document 4). In addition, as a means for enhancing the long-term storage stability of the aroma component, for example, as an agent for suppressing the production of a deteriorated odor derived from citral and a method for suppressing the same, epigallocatechin gallate and / or epicatechin in combination with epigallocatechin or epigallocatechin. Is disclosed (Patent Document 5).

Japanese Unexamined Patent Publication No. 2005-206596 International Publication 2011/152006 Tokukousho 48-18834 Japanese Unexamined Patent Publication No. 8-116882 JP-A-2002-338990

Journal of physiological Anthropology (2018) 37: 3 Safety / Effectiveness Information of "Health Foods"-Material Information Database of Health Foods Cha (Tea) Updated: September 3, 2019 (National Institute of Health and Nutrition)

As a means for recovering the aroma component of black tea, a method by steam distillation is effective in terms of recovery efficiency of the aroma component. However, in this method, since it is necessary to bring high-temperature steam into contact with the tea leaves, there is a problem that an unpleasant heat-distilled odor is generated. Especially when it is applied to an aroma diffuser, it is required to solve this problem, but in the conventional technique of contacting the distillate obtained by steam distillation of tea with tea leaves, the tea leaf extract itself is included. Not applicable to aroma diffusers. Further, the method of adding an organic non-volatile substance having an antioxidant property such as catechins cannot be applied because it causes pollution in the aroma diffuser and the room. Therefore, an object of the present invention is to provide an aqueous solution for an aroma diffuser derived from black tea leaves, which maintains the same aroma tone as when drinking black tea and suppresses the generation of unpleasant odors.

The present inventors investigated a method for recovering the aroma component for the purpose of diffusing the aroma component obtained from the black tea leaf into the living space with an aroma diffuser, and compared it with the method of directly steam-distilling the black tea leaf. It has been found that aroma water having preferable aroma quality can be obtained by distilling the extract obtained by once extracting black tea leaves with water under reduced pressure. In addition, depending on the lot of tea leaves, storage conditions, manufacturing conditions, etc., this aroma water has a problem that an unpleasant scent accompanied by a sense of discomfort occurs and the aroma quality deteriorates. As a result, it was found that the cause of the unpleasant scent was identified, and as a countermeasure, when the pH was adjusted within a specific range during the manufacturing process of aroma water, the deterioration of the aroma quality due to the unpleasant scent could be effectively suppressed. , The present invention has been completed. It has not been known so far that the quality of such aroma derived from black tea leaves changes depending on pH and can be improved by adjusting pH.

That is, the present invention is as follows.
[1] A method for producing an aqueous solution for an aroma diffuser containing an aroma component derived from tea leaves, which is the first step of extracting tea leaves with water, and the obtained extract is distilled under reduced pressure to recover the evaporated portion as aroma water. A method for producing an aqueous solution for an aroma diffuser, which comprises a second step of adjusting the pH of the recovered aroma water to 5.0 to 6.5.
[2] The method for producing an aqueous solution for an aroma diffuser according to [1], wherein a step of concentrating aroma water with an RO membrane is provided between the second step and the third step.
[3] The method for producing an aqueous solution for an aroma diffuser according to [1] or [2], wherein in the second step, the pH of the extract is adjusted to 5.0 to 6.5 and then distillation under reduced pressure is performed.
[4] An aqueous solution for an aroma diffuser containing an aroma component derived from black tea leaves and satisfying the following (I) to (III).
(I) Linalool among the aroma components is 10 ppb to 100 ppm
(II) pH 5.0-6.5
(III) Substantially free of polyphenols
[5] The aqueous solution for an aroma diffuser according to [4], which further satisfies the following (IV).
(IV) The peak area ratio of caproic acid to linalool (caproic acid / linalool) when analyzed by SPME-GC / MS is 0.040 or less.
[6] The peak area ratio ("fresh" / "heated") of the "fresh" aroma component and the "heated" aroma component when analyzed by SPME-GC / MS is 5.0 or more. The aqueous solution for an aroma diffuser according to [4] or [5], which satisfies the above requirements.
[7] A method for improving the aroma quality of black tea leaf-derived aroma water, which comprises adjusting the pH of an aqueous solution containing black tea leaf-derived volatile components and substantially free of polyphenols to 5.0 to 6.5.
[8] The method for improving the aroma quality of aroma water derived from black tea leaves, which is characterized in that the improvement of aroma quality suppresses the volatilization of caproic acid.

According to the present invention, it is possible to provide an aqueous solution derived from black tea leaves that has the same scent as when drinking black tea but does not have an unpleasant scent, and can be suitably used for aroma diffusion with an aroma diffuser. it can.

Hereinafter, the present invention will be described in detail. The aqueous solution for an aroma diffuser of the present invention is a recovery solution containing an aroma component obtained by vacuum distillation from an extract of black tea leaves, and has an unpleasant odor because the pH is adjusted within a specific range. It is characterized in that the occurrence is suppressed.

The aroma diffuser in the present invention means a device for diffusing aroma contained in aroma water, aroma oil, etc. For example, a super-mist that diffuses water containing an aroma component into air by vibration of ultrasonic waves. In addition to the sonic aroma diffuser and the heated aroma diffuser that evaporates water containing aroma components by a heat source and diffuses it into the air, a vaporization type aroma diffuser that naturally vaporizes the aroma components using pottery, non-woven fabrics, reeds, etc. and so on. The aqueous solution for an aroma diffuser is an aqueous solution for diffusing an aroma component with an aroma diffuser, and is an aroma water in which the aroma component is dissolved in a solvent mainly composed of water. In the present invention, it means a state in which the aroma component derived from black tea leaves is dissolved, that is, black tea aroma water.

The aqueous solution for an aroma diffuser of the present invention contains a fraction in which aroma components are recovered from black tea leaves as a raw material. The black tea leaves used as raw materials are from the leaves and stems of Camellia sinensis, which is an evergreen tree of the genus Camellia of the Theaceae family, from the Chinese (var. Sinensis) and Assam (var. Assamica) species or their hybrids. Examples include those made from tea through a fermentation process. The tea leaves may be, for example, from India, Sri Lanka, Indonesia, Kenya, China, or any other origin, and they may be leaf grade, broken grade, or other tea leaf grade. .. In addition, semi-fermented tea with a rich fragrance like Dongfang meiren from Taiwan, flower tea like jasmine tea, green tea, etc. can be treated as raw materials in the same way as black tea. These tea leaves may be used alone or in combination of two or more. Further, these may be crushed, broken or cut in advance in order to improve the extraction efficiency.

The present invention is characterized in that black tea leaves are once extracted with water to obtain an extract, as in the case of serving black tea for drinking (first step in the production method of the present invention).
The temperature of the water at the time of extraction may be set according to the desired balance of aroma and the characteristics of the tea leaves used as the raw material, and may be appropriately selected at a temperature of 0 to 100 ° C. For example, when the purpose is to have a gorgeous light scent such as flowers and fruits, 0 to 60 ° C is preferable, 5 to 60 ° C is more preferable, and 10 to 30 ° C is even more preferable. On the other hand, when the purpose is to have a strong and heavy scent, 60 to 100 ° C is preferable, 70 to 100 ° C is more preferable, and 80 to 100 ° C is even more preferable. In addition, it can be extracted at a temperature of 100 ° C. or higher using a pressure vessel.

The time for extraction is not particularly limited, and it may be appropriately set in balance with the extraction temperature according to the purpose. When the extraction temperature is low, the extraction rate of the fragrance component becomes slow, so a long time is set, and when the extraction temperature is high, the fragrance component is quickly extracted, so that the extraction can be performed in a short time. For example, the extraction time is 30 minutes to 4 hours when extracting at a low temperature of 10 to 30 ° C, and 5 minutes to 30 minutes when extracting at a high temperature of 70 to 100 ° C. By using tannase or glycoside degrading enzymes (various glycosidases, etc.) in the extract during or after extraction, the extraction efficiency is improved and the aroma component is released from the aroma precursor. It is also possible to enhance the aroma component.

Examples of the tea leaf extraction method include known methods such as a batch type extraction method using a kneader or an extraction tank, and a column type extraction method using an extraction tower (column type extractor). The ratio of tea leaves to extracted water at the time of extraction is appropriately selected depending on the type of raw tea leaves, the type of extraction machine, flavor, etc. For example, 4 to 30 parts by weight of the extraction solvent is selected with respect to 1 part by weight of the raw tea leaves. , And 8 to 20 parts by weight is preferable in terms of extraction efficiency, manufacturing cost and quality.

In the present invention, the extract containing the aroma component, which is a volatile component, is recovered by distilling the extract from the tea leaves and condensing the evaporated component by cooling (second in the production method of the present invention). Process). Generally, when recovering an aroma component from a plant material, a means for directly recovering the aroma component by steam distillation is used, but in the present invention, the steam distillation method is adopted in terms of fragrance quality. It is not preferable, and in order to maintain the aroma of black tea when drinking, it is preferable to distill the extract obtained by extracting from the tea leaves under reduced pressure.
As the apparatus used for vacuum distillation, for example, a centrifugal thin film concentrator (distillation) apparatus, an ascending or flowing thin film concentrator, a rotary evaporator, a gas-liquid countercurrent catalytic distillation apparatus such as a spinning cone column, or the like can be applied. Among these, a centrifugal thin film concentrating (distillation) device is suitable because it can efficiently distill at a low temperature in a short time, so that the aroma component composition is not disturbed and the component loss is small. Examples of commercially available devices include "Sentrisarm Evaporator" manufactured by Alfa Laval and "Evapol" manufactured by Okawara Seisakusho.

Condensed water (fragrant water) containing an aroma component obtained by distillation may be appropriately concentrated as needed. Since the aroma component has a low boiling point, concentration using an RO membrane (reverse osmosis membrane: Reverse Osmosis Membrane), which has little loss due to evaporation, is suitable. When the salt blocking rate, which represents the properties of the membrane, is 90% or more, preferably 95% or more, more preferably 99% or more, the loss of aroma components is small, and therefore, it is suitably used for producing the aqueous solution for an aroma diffuser of the present invention. be able to. The concentration operation using the RO membrane is not particularly limited, but the conditions may be appropriately set in the temperature range of about 5 to 50 ° C. under a pressure of 0.1 to 50 MPa. By this concentration treatment, the concentration of aroma components in the aqueous solution can be significantly increased.

The aqueous solution for an aroma diffuser of the present invention contains one or more of the following aroma components. Due to the sensual characteristics of the aroma, these are (A) citrus flower-like, (B) sweet flower-like, (C) mellow flower-like, (D) Woody-like, (E) green-like, and (F) cool-like. It was classified into 6 groups. (A) Citrus flowers are linalool (linalool), linalool oxide (cis-franoid type) (linalool oxide (cis-franoid)), linalool oxide (trans flanoid type) (linalool oxide (trans-franoid)), linalool oxide (trans-franoid). cis pyranoid type) (linalool oxide (cis-pyranoid)), linalool oxide (trans-pyranoid type) (linalool oxide (trans-pyranoid)), phototrienol, citral, nerol, geraniol And α-terpineol, (B) sweet flowers are benzaldehyde, phenylacetaldehyde, β-damascenone, benzylalcohol, 2-phenyl A group consisting of ethyl alcohol (2-phenylethylalcohol) and cis-jasmone, (C) mellow flower-like, 6-methyl-5-hepten-2-one (6-methyl-5-hepten-2-one). one), β-cyclocitral, α-ionone, β-ionone, and 5,6-epoxy-β- The group consisting of ionone, (D) Woody-sama, is β-myrcene, α-terpinene, γ-terpinene, D-limonene, α. -From ferlandrene (α-phellandrene), cis-β-ocimene (cis-β-ocimene), trans-β-ocimene (trans-β-ocimene), p-cymene (p-cymene) and terpinolene (terpinolene) Group, (E) Green-like, is hexanal, trans-2-hexen-1-al, cis-3-hexenyl acetate. -1-ol-acetate), hexanol (h exanol), cis-3-hexen-1-ol (cis-3-hexen-1-ol), trans-2-hexen-1-ol (trans-2-hexen-1-ol) and butyric acid trans-3-3 The group consisting of trans-3-hexenyl butyrate and (F) Cool-like group consist of methyl salicylate. In addition, hexanoic acid may be contained as a component exhibiting an unpleasant scent. These balances can be analyzed by measuring the ratio (IS ratio) to the internal standard by solid-phase microextraction gas chromatograph mass spectrometry (SPME-GC / MS spectrometry).

The aqueous solution for an aroma diffuser of the present invention contains one or more of the aroma components derived from black tea leaves, and among these, the content of linalool, which is a typical aroma component of black tea, is 10 ppb ~. It is 100 ppm. If the linalool content in the aqueous solution is less than 10 ppb, it is difficult to sensually recognize the aroma of black tea when diffused with an aroma diffuser. On the other hand, the upper limit does not need to be particularly limited, but if the concentration exceeds 100 ppm, the intensity of the fragrance is too strong and may cause discomfort. In addition, it is preferable to maintain the balance of the black tea leaves used for aroma components other than linalool. The content of linalol can be quantified by solid-phase microextraction gas chromatograph mass spectrometry (SPME-GC / MS spectrometry).

The aqueous solution for an aroma diffuser of the present invention includes linalool, linalool oxide (cis flanoid type), linalool oxide (trans flanoid type), phototrienol, geraniol, hexanol, cis-3-hexene-1-ol, and trans-2-hexen-1. -Fresh "fresh" scent component consisting of 8 types of oar, and 5 types of phenylacetaldehyde, β-damasenone, α-yonone, β-yonone, and 5,6-epoxy-β-yonone The sum of each peak area (IS ratio) measured by solid-phase microextraction gas chromatograph mass spectrometry (SPME-GC / MS spectrometry) for the scent component of the heavy "heating system" of the heated image. The value ratio (“fresh” / “heating”) is 3.0 or higher. The above-mentioned aroma components have a high degree of contribution to the aroma quality of black tea, and it is preferable that the ratio thereof is a certain level or more. If this ratio is less than 3.0, there is a large deviation from the aroma balance originally possessed by the black tea extract, and a sense of discomfort accompanied by an unpleasant impression is recognized. Further, this ratio is more preferably 5.0 or more, and further preferably 10.0 or more.

In the aqueous solution for an aroma diffuser of the present invention, the generation of an unpleasant odor due to caproic acid is suppressed by adjusting the pH. Caproic acid is a linearly saturated carboxylic acid, also called capronic acid, and is a causative component of characteristic unpleasant odors reminiscent of human and animal sweat and body odor. The tea extract contains an acidic odorous component such as caproic acid, but it is neutralized by other components in normal drinking, and it is considered that there is little problem. However, since the neutralizing action does not work in the solution from which only the volatile components are extracted by distillation or the like, it is presumed that it causes an unpleasant odor when the aroma diffuser is used. In the present invention, caproic acid is suppressed as compared with a useful aroma component by adjusting the pH, and for linalool, which is a typical aroma component, the peak area (IS ratio) in SPME-GC / MS analysis. The ratio (caproic acid / linalool) is 0.040 or less. If this ratio (caproic acid / linalool) exceeds 0.040, an unpleasant scent is conspicuous, and the divergence from the scent of the original black tea becomes large, which is not preferable. The peak area ratio of caproic acid / linalool is preferably 0.031 or less, more preferably 0.025 or less.

The aqueous solution for an aroma diffuser of the present invention is characterized in that the pH is finally adjusted to 5.0 to 6.5 (third step in the production method of the present invention). When the pH is in this range, the same aroma tone as when drinking black tea can be maintained. In the region where the pH is lower than 5.0, an unpleasant acidic odor derived from caproic acid or the like becomes conspicuous, and in the region where the pH exceeds 6.5, an unpleasant alkaline odor becomes conspicuous, which is not preferable. The pH is more preferably 5.3 to 6.5, and even more preferably 5.3 to 6.3. The pH may be adjusted either for the recovered liquid (fragrant water) by vacuum distillation or for the concentrated liquid concentrated with the RO membrane. If the same pH adjustment is performed on the tea leaf extract and then distilled under reduced pressure, the transfer of offensive odor components such as caproic acid from the extract to the aroma recovery solution can be suppressed. By doing so, the aroma quality can be further improved. However, a method of adding sodium hydrogen carbonate or the like to the extraction water at the time of extraction to raise the pH at the time of extraction is not preferable because it causes an increase in an alkaline-like unpleasant odor.

Examples of the pH adjuster that can be used for adjusting the pH include sodium citrate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium hydroxide, potassium hydroxide, ammonium hydrogen carbonate, ammonium carbonate, ammonium hydroxide, and tripotassium phosphate. Potassium, dipotassium hydrogen phosphate, trisodium phosphate, disodium hydrogen phosphate, sodium gluconate, potassium gluconate, phosphate, tartrate acid, sodium tartrate, citrate, sodium citrate, lactic acid, sodium lactate, acetic acid, acetic acid Examples include sodium and the like. These pH adjusters may be used alone or in combination of two or more. The aroma recovery solution obtained by vacuum distillation of tea leaves tends to tilt toward the acidic side near pH 4, and sodium hydrogen carbonate and sodium carbonate, which are generally used in food production, are often used to adjust these to a predetermined pH. , Sodium hydroxide and potassium carbonate can be preferably used. Of these, sodium hydrogen carbonate, which can adjust the pH gently, is particularly preferable.

The aqueous solution for an aroma diffuser of the present invention is obtained by recovering a volatile fraction containing an aroma component from a black tea extract by distillation under reduced pressure. Therefore, since the polyphenol content, which is the main component of black tea, is non-volatile, it is not substantially contained in the aqueous solution for the aroma diffuser of the present invention. Here, the fact that the polyphenol content is substantially not contained means that the polyphenol content is 1000 ppb or less in terms of 1 ppb of linalool, that is, the ratio of polyphenol / linalool is 1000 or less. When diffusing aroma components, if an ultrasonic or spray type aroma diffuser device is used, non-volatile components such as polyphenols will also be diffused at the same time, but when they adhere to the floor or wall, they will be diffused at the same time. It is not preferable to contain more than a certain amount of polyphenols because it causes coloring, causes the growth of microorganisms, and also causes contamination of the aroma diffuser itself. The polyphenol content is preferably a ratio of linalool to 200 or less, more preferably 50 or less. The content of polyphenol (tannin) can be quantified by the iron tartrate absorptiometry described in "7th Edition Standard Tables of Food Composition Analysis Manual / Explanation".

The aqueous solution for an aroma diffuser of the present invention may contain an aroma component other than the aroma component derived from black tea, if necessary. Aroma oils recovered from herbs, flowers, trees, spices, fruits, etc. and their preparations include bergamot oil, chamomile oil, cinnamon oil, geranium oil, ginger oil, grapefruit oil, jasmine absolute, etc. Examples thereof include jasmine concrete, lavender oil, lemon oil, lime oil, orange oil, orange flower absolute, peppermint oil, rose oil, sandalwood oil, sparemint oil, and ylang ylang oil. Further, an aroma component obtained by chemical synthesis or a mixture thereof may be blended. In addition, solvents such as ethanol, ethylene glycol, propylene glycol, dipropylene glycol, glycerin, hexyl glycol, benzylbenzoate, triethylcitrate, polysorbate and diethylphthalate may be blended. In addition to these, if necessary, a preservative, a shelf life improver, an antioxidant, an antibacterial agent, an insecticide, an insect repellent, a repellent, a deodorant and the like may be blended.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples.

<< Aroma component analysis and quantification method by SPME-GC / MS >>
10 mL of an appropriately diluted sample solution and 3 g of sodium chloride were placed in a 20 mL SPME vial, and cycloheptanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as an internal standard substance to a final concentration of 500 ppb. did. The aroma component was recovered by solid phase microextraction (SPME) and subjected to gas chromatograph mass spectrometry (GC / MS analysis). The GC / MS analysis conditions are as follows. The ratio of the peak area of each aroma component to the internal standard substance (IS ratio) was defined as the peak area value.
Quantification is performed as standard substances such as linalool (manufactured by Tokyo Chemical Industry Co., Ltd.), hotorienol (synthesized by a known synthetic method), methyl salicylate (manufactured by Tokyo Chemical Industry Co., Ltd.), trans-2-hexene. -1-R (trans-2-hexen-1-al: manufactured by Tokyo Chemical Industry Co., Ltd.), cis-3-hexen-1-ol (cis-3-hexen-1-ol: manufactured by Tokyo Chemical Industry Co., Ltd.), geraniol (Geraniol: manufactured by Tokyo Chemical Industry Co., Ltd.) and 2-phenylethyl alcohol (2-phenylethylalcohol: manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in ultrapure water, diluted stepwise, and used as a standard solution. 10 mL of each standard solution and 3 g of sodium chloride were placed in a 20 mL SPME vial, and cycloheptanol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added as an internal standard substance to a final concentration of 500 ppb. The aroma components were recovered by solid phase microextraction and subjected to GC / MS analysis for linalool, phototrienol, methyl salicylate, trans-2-hexen-1-ar, cis-3-hexen-1-ol, geraniol and 2-. Phenylethyl alcohol was quantified.

<SPME-GC / MS conditions>
・ GC: TRACE GC ULTRA (Thermo Fisher Scientific)
・ MS: TSQ QUANTUM XLS (Thermo Fisher Scientific)
・ SPME fiber: 50/30 μm Divinylbenzene / Carboxen / Polydimethylsiloxane Stableflex (Sigma-Aldrich)
・ Extraction: 60 ℃, 30 minutes ・ Column: SUPELCO WAX10 0.25mm I.D. × 60m × 0.25μm (Sigma-Aldrich)
・ Oven program: After holding at 40 ℃ for 2 minutes, raise the temperature to 160 ℃ at 3 ℃ / min, and then raise the temperature to 280 ℃ at 10 ℃ / min. ・ Carrier gas: Helium (100 kPa, constant pressure)
・ Injector temperature: splitless, 240 ℃
・ Ion source temperature: 200 ℃
・ Ionization: Electron ionization ・ Ionization voltage: 70eV
・ Measurement mode: Scan

<Monitoring ion>
Hexanal; m / z = 56, trans-2-hexen-1-al; m / z = 69, cis-3-hexenyl acetate (cis-3) -hexen-1-ol-acetate); m / z = 67, hexanol; m / z = 56, cis-3-hexen-1-ol (cis-3-hexen-1-ol); m / z = 67, trans-2-hexen-1-ol; m / z = 57, trans-3-hexenyl butyrate; m / z = 67, β-myrcene; m / z = 93, α-terpinene; m / z = 121, γ-terpinene; m / z = 93, D-limonen (D-limonene); m / z = 68, α-ferandrene; m / z = 93, cis-β-ocimene; m / z = 93, trans-β -Osimen (trans-β-ocimene); m / z = 93, p-cymene (p-cymene); m / z = 93, terpineolene; m / z = 119, linalool; m / z = 93, linalool oxide (cis-franoid); m / z = 93, linalool oxide (trans-franoid); m / z = 93, linalol Oxide (cis-pyranoid type) (linalool oxide (cis-pyranoid)); m / z = 94, linalool oxide (trans-pyranoid type) (linalool oxide (trans-pyranoid)); m / z = 94, hotrienol; m / z = 71, citral; m / z = 94, nerol; m / z = 69, geraniol; m / z = 69, α-terpineol; m / z = 93, benzaldehyde; m / z = 109, phenylacetaldehyde; m / z = 91, β-damaseno (Β-damascenone); m / z = 121, benzyl alcohol (benzylalcohol); m / z = 91, 2-phenylethylalcohol; m / z = 91, cis-jasmone M / z = 122, 6-methyl-5-hepten-2-one; m / z = 108, β-cyclocitral; m / z = 152, α-ionone (α-ionone); m / z = 121, β-yonone (β-ionone); m / z = 177, 5,6-epoxy-β-yonone (5,6-epoxy-) β-ionone); m / z = 123, methyl salicylate; m / z = 120, hexanoic acid; m / z = 60, cycloheptanol; m / z = 57

The quantification of polyphenols (tannins) is supervised by the Resources Office, Policy Division, Science and Technology Policy Bureau, Ministry of Education, Culture, Sports, Science and Technology, Akemi Yasui, Tomoko Watanabe, Takashi Nakazato, edited by Kenichi Fuchigami, "Seventh Edition Japanese Food Standard Ingredients Analysis Manual / Explanation", Kenjosha, 2016 On February 25, 2014, the method was performed according to the iron tartrate absorptiometry described on pages 242-243. Ethyl gallate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the standard substance for quantification.

<Reference example>
While 180 Kg of raw material tea leaf A (black tea leaf from Darjeeling, India) was dispersed in warm water at 65 ° C., a 150 mesh filter was filled in a column extractor installed at the outlet and held for 15 minutes. Then, warm water at 65 ° C. was passed through to obtain 1600 L of an extract of Brix 2.81 (extract A of Reference Example 1). 1600 L of this extract is evaporated under reduced pressure at 75 ° C using a vacuum distiller (manufactured by Nichinan Machinery Co., Ltd., a continuous double-effect four-can type liquid film flow-down concentrator), and condensed water containing aroma components (reference example). 2 Aroma recovery solution A) 74 L was recovered. Further, this aroma recovery liquid A was concentrated by an RO membrane. The RO membrane was treated with NTR-759HG (manufactured by Nitto Denko, salt blocking rate: 99%) at a pressure of 1.08 MPa and a flow velocity of 1300 L / H, and 110 L of aroma recovery liquid A to 7 L of concentrated liquid (Reference Example 3). Aroma concentrate A) was obtained.

280 g of raw material tea leaf A (black tea leaf from Darjeeling, India) was steam distilled at about 94 ° C. using a vacuum steam distillation apparatus to obtain 224 g of the aroma recovery liquid B of Reference Example 4 as a distillation fraction.

Regarding these extracts A (reference example 1), aroma recovery solution A (reference example 2), aroma concentrate A (reference example 3), and aroma recovery solution B (reference example 4), the aroma components and polyphenols obtained by GC / MS Analysis was carried out. Further, the scent of the extract A (Reference Example 1) in a state of being transferred to a cup after being heated to 90 ° C. was confirmed. Using this as a control, an aroma diffuser was used for a solution in which the linarol concentration of each of the aroma recovery solution A (Reference Example 2), the aroma concentrate A (Reference Example 3), and the aroma recovery solution B (Reference Example 4) was adjusted to 400 ppb. Diffused using (Ultrasonic Aroma Diffuser 11SS manufactured by Ryohin Keikaku Co., Ltd.), and sensory evaluation by 6 panelists based on the following criteria for "freshly brewed tea feeling" and "unpleasant odor" as fragrance quality. The evaluation points obtained were averaged, and a comprehensive evaluation was made based on these results. These results are shown in Table 1.

<< Evaluation criteria for "freshly brewed black tea">>
1: I don't feel the feeling of freshly brewed black tea
2: Feel the feeling of freshly brewed black tea
3: Feel a little freshly brewed black tea
4: Feel the feeling of freshly brewed black tea
5: I strongly feel the feeling of freshly brewed black tea

<< Evaluation criteria for "unpleasant odor">>
1: I feel a strong unpleasant odor
2: I feel an unpleasant odor
3: I feel a little unpleasant odor
4: Slightly unpleasant odor
5: Do not feel unpleasant odor

<< Comprehensive evaluation criteria >>
◎: Very good (a strong feeling of freshly brewed black tea and no unpleasant odor)
〇: Good (feels like freshly brewed black tea and hardly feels unpleasant odor)
△: Neither can be said (a feeling of unpleasant odor is felt along with the feeling of freshly brewed black tea)
×: Bad (unpleasant odor is more noticeable than freshly brewed black tea)

From the results in Table 1, the aroma recovery liquid (Aroma recovery liquid A of Reference Example 2) and the aroma concentrate (Aroma concentrate A of Reference Example 3) obtained by distilling the tea leaf extract under reduced pressure are the extracts from tea leaves. It was confirmed that the aroma component balance was similar to that of (Extract A of Reference Example 1). On the other hand, in the aroma recovery solution recovered by steam distillation (aroma recovery solution B in Reference Example 4), unlike the aroma balance of the tea leaf extract (extraction A in Reference Example 1), fresh like linalool or phototrienol. The ratio of heavy scents of heating system such as β-damascenone and β-ionone is increasing to the light scent of the system, and it is evaluated that the roasting feeling is strong sensually, so I do not feel a good impression. It was. Further, in the composition prepared by vacuum distillation, the ratio of the fresh aroma component to the heated aroma component (fresh aroma / heated aroma) roughly maintained the ratio of the hot water extract, but by steam distillation. It was confirmed that the ratio of the fresh aroma to the heated aroma was low in the prepared aroma recovery solution (aroma recovery solution B of Reference Example 4). The polyphenol content in the aroma aqueous solutions of Reference Examples 2 to 4 (Aroma recovery solution A of Reference Example 2, Aroma concentrate A of Reference Example 3, and Aroma recovery solution B of Reference Example 4) may be extremely small. confirmed. On the other hand, the aroma recovery solution (Aroma recovery solution A of Reference Example 2) and the aroma concentrate (Aroma concentrate A of Reference Example 3) obtained by distilling the tea leaf extract under reduced pressure have an unpleasant acid such as sweat odor. It became clear that the problem was that the odor was felt.

<Example>
Using the aroma concentrate prepared in Reference Example (Aroma concentrate A in Reference Example 3), the effect of pH adjustment on aroma quality was investigated. Aroma concentrate A was diluted with ultra-pure water so that the linarol concentration was about 600 ppb, and this diluted solution (pH 4.50) was adjusted to an arbitrary pH. McIlvaine buffer solution (McIlvaine buffer solution) The pH was adjusted by adding 1% of buffer) to the concentrate A. The prepared aqueous solution was diffused using an aroma diffuser (Ultrasonic Aroma Diffuser 11SS manufactured by Ryohin Keikaku Co., Ltd.), and the fragrance quality of "freshly brewed tea feeling" and "unpleasant odor" was used as the standard described in the reference example. Based on this, sensory evaluation was performed by 6 panelists, the evaluation points were averaged, and a comprehensive evaluation was made based on these results. In addition, each composition was analyzed for each aroma component by SPME-GC / MS and polyphenol by the iron tartrate absorptiometry. These results are shown in Table 2.

From the results in Table 2, it was confirmed that when the pH was changed, there was a difference in the feeling of freshly brewed black tea and the feeling of an unpleasant odor. On the acidic side with a pH of 4 or less, an unpleasant acidic odor such as sweat odor is felt, and on the contrary, on the alkaline side with a pH of 7 or more, an unpleasant alkaline odor such as ash odor is felt, both of which cause a decrease in the score in the sensory evaluation. It was. On the other hand, from the analysis results by SPME-GC / MS, there was no significant difference in the whole pH range tested for linalool, which is the main aroma component of black tea, but caproic acid had a high quantitative value on the acidic side and the pH was high. It decreased as it became higher. Therefore, it was considered that the unpleasant acidic odor on the acidic side was caused by an acidic volatile component such as caproic acid. On the other hand, the components involved in the decrease in the sensory evaluation score on the alkaline side are unknown, but it is considered that the evaluation was low due to the promotion of volatilization of some components and the generation of odorous components. That is, it was confirmed that the unpleasant odor can be suppressed by adjusting the pH to 5.0 to 6.5. In the range of pH 5.0 to 6.5, the feeling of freshly brewed black tea was at a high level, and it was recognized as a preferable scent. In particular, the composition adjusted to pH 5.79 had a particularly strong feeling of freshly brewed black tea, and the score of unpleasant odor was also low.

According to the present invention, it can be suitably used for aroma diffusion with an aroma diffuser as an aqueous solution derived from black tea leaves that has the same scent as when drinking black tea but does not have an unpleasant scent. Can be usefully used as an aqueous solution of black tea.

Claims (6)

A method for producing an aqueous solution for an aroma diffuser containing an aroma component derived from tea leaves, the first step of extracting tea leaves with water, the second step of distilling the obtained extract under reduced pressure and recovering the evaporated portion as aroma water. A method for producing an aqueous solution for an aroma diffuser, which comprises the above step and a third step of adjusting the pH of the recovered aroma water to 5.0 to 6.5. The method for producing an aqueous solution for an aroma diffuser according to claim 1, further comprising a step of concentrating aroma water with an RO membrane between the second step and the third step. An aqueous solution for an aroma diffuser containing an aroma component derived from black tea leaves and satisfying the following (I) to (III).
(I) Linalool among the aroma components is 10ppb to 100ppm
(II) pH 5.0-6.5
(III) Substantially free of polyphenols The aqueous solution for an aroma diffuser according to claim 3, which further satisfies the following (IV).
(IV) The peak area ratio of caproic acid to linalool (caproic acid / linalool) when analyzed by SPME-GC / MS is 0.040 or less. A method for improving the aroma quality of black tea leaf-derived aroma water, which comprises adjusting the pH of an aqueous solution containing black tea leaf-derived volatile components and substantially free of polyphenols from 5.0 to 6.5. The method for improving the aroma quality of black tea leaf-derived aroma water according to claim 5, wherein the improvement of the aroma quality suppresses the volatilization of caproic acid.