Method for producing food and drink with green aroma, and food and drink

Abstract

To provide a simple method for producing a drink or food having a green aroma.SOLUTION: The present invention discloses a method for producing a drink or food having a green aroma, the method comprising: step A of subjecting a lipid containing a fatty acid having 10-18 carbon atoms to a photocatalyst treatment; and step B of heating the product having undergone the photocatalyst treatment in the step A. Preferably the lipid is derived from yeast and the food and drink are distilled liquor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a food or drink having a green aroma, and more particularly to a method for producing a distilled liquor having a green aroma. [Background technology]

[0002] Leaf aldehyde (i.e., the unsaturated aldehyde (2E)-hexenal) is known to be a component that produces the aroma commonly referred to as the green scent (Non-Patent Documents 1 and 2). Leaf aldehyde is found in vegetables and fruits as a component that contributes to the "grass-like" and "leaf-like" aromas of food.

[0003] Among the characteristic aromas recognized in high-quality Scotch whisky is a "green" aroma, and in the flavor wheel used to specifically describe the aroma of whisky, "Green / Grassy" is listed as the major aroma classification (innermost ring), and "Herbal, Leafy" are listed as the medium classification (middle ring) (Non-Patent Document 3).

[0004] Non-Patent Document 4 describes that, as a result of analyzing malt whiskey using multidimensional gas chromatography-mass spectrometry / olfactometry (MDGC-MS-O), E,Z-2,6-nonenal, E-2-nonenal, 1-octen-3-ol, 4-hepten-1-ol, and nonan-2-ol contribute to the green aroma.

[0005] Whisky does not contain leaf aldehyde. Nevertheless, there are products that feature a green aroma. Leaf aldehyde is characterized by a refreshing, grassy aroma, but the "green aroma" exhibited by the sensory sense of whiskey is a fresh or dry grass-like aroma. The mechanism by which the green aroma is produced in whiskey has not been elucidated.

[0006] Patent Document 1 relates to a product with a green aroma, a method for obtaining the product, and an alcoholic beverage containing the product. Patent Document 1 describes a method for obtaining a product with a green aroma, characterized by the action of lipoxygenase on unsaturated fatty acids in a culture medium, as well as the product and an alcoholic beverage containing the product. In Patent Document 1, a solution with a green aroma was actually added to whiskey and shochu, and a sensory test was conducted. The results showed that the aroma changes the taste of the distilled spirit, and that when a green aroma is detected, the taste becomes sweeter and more pleasant, which is an advantage. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-21055 [Non-patent literature]

[0008] [Non-Patent Document 1] Akikazu Hatanaka, "Fragrances of Plant Origin," FFI Journal, No. 168, 1996, pp. 5-22 [Non-patent document 2] Akikazu Hatanaka, "After the 5th Commemorative Symposium 'Why are humans refreshed by the scent of greenery?'", FFI Journal, No. 198, 2002, pp. 45-55 [Non-patent document 3] Charles W. Bamforth and Robert E. Ward (eds.), "The Oxford Handbook of Food Fermentations", Oxford University Press, 2014, pp. 238-241 [Non-patent document 4] Akira Wanikawa et al., "Identification of green note compounds in malt whisky using multidimensional gas chromatography," Flavor Fragr. J., 2002, No. 17, pp. 207-211 [Non-Patent Document 5] Hiroshi Kaneko et al., "Lipids of Yeast," Journal of the Japan Oil Chemists' Society, Vol. 20, No. 10, 1971, pp. 687-694 [Non-patent document 6] Yoko Murakami et al., "Lipid Composition of Commercial Baker's Yeasts Having Different Freeze-tolerance in Frozen Dough," Biosci. Biotech. Biochem, 1996, Vol. 60, No. 11, pp. 1874-1876 Summary of the Invention [Problem to be solved by the invention]

[0009] The method for producing a product with a green aroma described in Patent Document 1 requires complicated procedures such as preparing an appropriate culture medium, preparing koji mold as an enzyme source, pre-culturing it, and carrying out an enzyme reaction, etc. Therefore, the efficiency of producing a product with a green aroma is very low and the cost of implementation is high.

[0010] In Patent Document 1, the resulting green-aroma distillate is added to commercially available shochu or whiskey to produce whiskey or shochu with a green aroma. In other words, the product with a green aroma in Patent Document 1 is used as a flavoring. On the other hand, the use of additives such as flavorings is often prohibited during the production of distilled spirits such as whiskey (Non-Patent Document 3). As such, the product with a green aroma in Patent Document 1 has a narrow range of applications and is of low practical use.

[0011] Furthermore, it has not yet been clarified how to enhance the green aroma of food and beverages such as distilled alcoholic beverages.

[0012] The present invention solves the above-mentioned problems of the prior art, and its object is to provide a method for producing food and drink having a green aroma, which is simple to operate and highly practical. [Means for solving the problem]

[0013] The present inventors have discovered that straight-chain saturated aliphatic aldehydes, particularly straight-chain saturated aliphatic aldehydes having 6 to 10 carbon atoms, contribute to the green aroma of whiskey, and have devised a simple method for imparting a green aroma that is particularly practical in the production of distilled spirits.

[0014] The present invention provides a method for producing a food or beverage having a green aroma, which includes step A of photocatalytically treating a lipid containing a fatty acid having 10 to 18 carbon atoms, and step B of heating the photocatalytically treated product obtained in step A.

[0015] In one embodiment, the lipid is derived from yeast cells.

[0016] In one embodiment, the lipid includes a phospholipid of a fatty acid having 10 to 18 carbon atoms.

[0017] In one embodiment, the photocatalyst includes titanium oxide.

[0018] In one embodiment, lipid peroxides are produced in the step A.

[0019] In one embodiment, in the step B, a linear saturated aliphatic aldehyde having 6 to 10 carbon atoms is produced.

[0020] In one embodiment, step B is carried out in a substantially oxygen-free environment.

[0021] In one embodiment, the step B is carried out by distilling the mash containing the photocatalyst-treated product.

[0022] In one embodiment, the food or drink is a distilled alcoholic beverage.

[0023] The present invention also provides a method for producing a food or drink having a green aroma, which includes a step of incorporating a lipid that has been photocatalyst-treated and heated and that contains a fatty acid having 10 to 18 carbon atoms.

[0024] The present invention also provides a method for producing a food or beverage having a green aroma, which includes a step of heating a reaction target, The reaction object is a photocatalytically treated product of a lipid containing a fatty acid having 10 to 18 carbon atoms.

[0025] The present invention also provides a flavoring for food and drink that has been photocatalyst-treated and heated, and that contains a lipid containing a fatty acid having 10 to 18 carbon atoms, and that has a green odor.

[0026] The present invention also provides a food or drink having a green aroma, which contains a lipid containing a fatty acid having 10 to 18 carbon atoms that has been photocatalyst-treated and heated. [Effects of the Invention]

[0027] The method for producing a food or drink having a green aroma of the present invention can be incorporated into the production process of a general distilled alcoholic beverage, and the operation is simple. Furthermore, the method of the present invention can produce a food or drink having a green aroma as both a flavoring and a distilled alcoholic beverage. Therefore, the present invention has a wide range of applications and is highly practical. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a process diagram showing an example of a method for producing distilled spirits using the present invention. [Figure 2] FIG. 1 is a process diagram showing another example of a method for producing distilled spirits using the present invention. [Figure 3]FIG. 1 is a process diagram showing another example of a method for producing distilled spirits using the present invention. [Figure 4] FIG. 1 is a cross-sectional view showing an example of the structure of a reaction device used in photocatalytic treatment. DETAILED DESCRIPTION OF THE INVENTION

[0029] In the method of the present invention, a fatty acid having 10 to 18 carbon atoms is photocatalytically treated in an aqueous liquid, and the fatty acid after the photocatalytic treatment is thermally decomposed to produce a linear saturated aliphatic aldehyde having 6 to 10 carbon atoms. It is sufficient to produce any one type of linear saturated aliphatic aldehyde having 6 to 10 carbon atoms. In a preferred embodiment, linear saturated aliphatic aldehydes having 6, 7, and 9 carbon atoms are all produced. In a more preferred embodiment, linear saturated aliphatic aldehydes having 6 to 9 carbon atoms are all produced. In an even more preferred embodiment, linear saturated aliphatic aldehydes having 6 to 10 carbon atoms are all produced.

[0030] The linear saturated aliphatic aldehydes having 6 to 10 carbon atoms are preferably 1-hexanal, 1-heptanal, 1-octanal, 1-nonanal, and 1-decanal. At least one aldehyde selected from the group consisting of 1-hexanal, 1-heptanal, 1-octanal, 1-nonanal, and 1-decanal may be referred to as a "green aldehyde" hereinafter.

[0031] Lipids containing fatty acids having 10 to 18 carbon atoms can be used as raw materials for photocatalytic treatment. Lipids containing fatty acids having 10 to 18 carbon atoms include free fatty acids having 10 to 18 carbon atoms, esters of fatty acids having 10 to 18 carbon atoms and glycerol (i.e., neutral lipids), monovalent esters of fatty acids having 10 to 18 carbon atoms and higher alcohols (i.e., waxes), complex esters of fatty acids having 10 to 18 carbon atoms, alcohols, phosphoric acid, and nitrogen compounds (i.e., phospholipids), and complex esters of fatty acids having 10 to 18 carbon atoms, alcohols, sugars, and nitrogen compounds (i.e., glycolipids).

[0032] Preferable raw materials for photocatalytic treatment include fatty acids having 10 to 18 carbon atoms, esters of fatty acids having 10 to 18 carbon atoms, and phospholipids of fatty acids having 10 to 18 carbon atoms.

[0033] For example, yeast, regardless of the type, contains phospholipids within its cells. The phospholipids within the yeast cells contain unsaturated fatty acids as constituent components. Non-Patent Document 5, Table 1 on page 689, lists the fatty acid composition of yeast membrane lipids. A portion of the composition is shown below.

[0034] Capric acid (C10): <1% Lauric acid (C12): <1% Myristic acid (C14): 3±0.6% Palmitic acid (C16:0): 7±0.5% Palmitoleic acid (C16:1): 53±1% Stearic acid (C18:0): 2±0.5% Oleic acid (C18:1): 35±1%

[0035] The lipid composition of baker's yeast is described in Table II on page 1875 of Non-Patent Document 6. The lipid components of yeast strains are listed, including neutral lipids, free fatty acids, sterols, and phospholipids, along with their contents.

[0036] Therefore, yeast can be used as a raw material for photocatalytic treatment. Yeast decomposition products obtained by decomposing yeast cells can also be used as raw materials for photocatalytic treatment. Specific examples of yeast decomposition products include the residue obtained by extracting extract components from yeast cells and the dried yeast cell walls.

[0037] The yeast that can be used in the method of the present invention is not particularly limited as long as it is a type that has lipids containing fatty acids having 10 to 18 carbon atoms in its cells. Examples of such yeast include yeasts of the genus Candida, yeasts of the genus Pichia, and yeasts of the genus Kluyveromyces. Among these yeasts, those used as beer yeast, whiskey yeast, and wine yeast are preferred, and ale beer yeast and whiskey yeast, which have a high content of unsaturated fatty acids, are particularly preferred.

[0038] Preferably, the yeast used as the raw material for photocatalytic treatment is in the form of pressed or dried yeast. The yeast cells are recovered from a cell suspension using a filter such as a rotary vacuum dehydrator or a filter press and dehydrated to prepare pressed yeast cells with a moisture content of 60 to 75% (hereinafter referred to as pressed yeast), or the pressed yeast is further dried using a dryer to prepare dried yeast cells with a moisture content of 2 to 12%.

[0039] Photocatalytic treatment is carried out by adding the raw material to be photocatalytically treated to an aqueous liquid, bringing it into contact with the photocatalyst, and irradiating it with light that excites the photocatalyst. An aqueous liquid is a substance that contains water and exhibits fluidity. The aqueous liquid shields the reactants from oxygen and functions as a medium for transferring heat to the reactants. The aqueous liquid may be water, an aqueous solution, or a heterogeneous mixture containing solids. The aqueous liquid may also contain alcohol.

[0040] In photocatalytic treatment, the photocatalytic function is exerted by irradiation with excitation light such as ultraviolet light. Therefore, preferably, no reaction reagents other than the photocatalyst are added to the aqueous liquid. Titanium dioxide is preferably used as the photocatalyst. Titanium dioxide has excellent chemical stability and does not cause problems such as decomposition or elution.

[0041] This section briefly explains the basic principles of photochemical reactions using titanium dioxide as a catalyst. When light of the excitation wavelength is irradiated onto the solid surface of titanium dioxide, electrons are excited from the ground state to the excited state. In the excited state, holes are generated near the upper limit of the valence band within the solid titanium dioxide, and excited electrons are generated near the lower limit of the conduction band. These excited electrons and holes migrate from within the solid titanium dioxide to its surface, where they react with foreign molecules. The raw materials to be photocatalytically treated, such as fatty acids with 10 to 18 carbon atoms, are oxidized by the photocatalytic reaction and converted into lipid peroxides.

[0042] The photocatalyst can be brought into contact with the raw material to be photocatalytically treated in either a suspended state or an immobilized state. In the suspended contact state, a powdered photocatalyst is mixed into an aqueous liquid containing the raw material to be photocatalytically treated. In the immobilized contact state, a powdered photocatalyst is immobilized as a photocatalytic film on the surface of a reaction vessel, and the reaction vessel is filled with an aqueous liquid containing the raw material to be photocatalytically treated.

[0043] The amount of photocatalyst used is an amount that corresponds to a concentration of 0.01 to 5% by weight in the aqueous liquid. If the amount of photocatalyst is less than 0.05% by weight of the aqueous liquid, the photocatalytic reaction does not proceed sufficiently, and if it exceeds 5% by weight, unintended side reactions increase. The amount of photocatalyst used is preferably 0.05 to 3% by weight, more preferably 0.1 to 1% by weight of the aqueous liquid.

[0044] The excitation light irradiated onto the photocatalyst is, for example, light having a wavelength between 254 nm and 365 nm when the photocatalyst is titanium dioxide. The irradiation time of the excitation light is appropriately adjusted taking into consideration the wavelength and light intensity of the light source. This prevents excessive oxidation of the raw material to be treated with the photocatalyst.

[0045] The amount of linear saturated aliphatic aldehyde produced and the sensory evaluation results of the food can be used as evaluation indicators for adjusting the reaction time. In addition, to prevent unintended side reactions of the raw materials to be photocatalytically treated, it is preferable to carry out the photocatalytic treatment while maintaining the aqueous solution at a temperature lower than 25°C.

[0046] Next, the photocatalytically treated raw material, i.e., the photocatalytically treated product, is used as the reaction target and heated. By heating the photocatalytically treated product, the lipid peroxides produced by the photocatalytic treatment are decomposed to produce green aldehyde. The photocatalytically treated product is heated in an aqueous liquid. In this case, the photocatalytically treated product may be heated in the aqueous liquid in which it was photocatalytically treated, or may be heated in a state where it has been transferred to another aqueous liquid.

[0047] The heating temperature of the photocatalyst-treated product is sufficient as long as it is a temperature at which the generated lipid peroxides are decomposed. From the viewpoint of decomposition efficiency, the heating temperature is preferably 70°C or higher, more preferably 80 to 110°C, and even more preferably 90 to 100°C, when heating at normal pressure. Furthermore, when heating under reduced pressure, it is desirable to heat at 40 to 70°C. The photocatalyst-treated product may be heated by distilling the aqueous liquid.

[0048] For example, when the food or beverage is a distilled alcoholic beverage, the photocatalytically treated product can be heated by distilling moromi (fermented mash) as an aqueous liquid containing the photocatalytically treated product. Moromi refers to an intermediate raw material for an alcoholic beverage, which is produced by fermenting a starch raw material, koji, water, and yeast. The amount of the photocatalytically treated product contained in the moromi to be distilled is appropriately determined taking into consideration the level of green aroma to be generated. Generally, the photocatalytically treated product is contained in the moromi in an amount of 0.01 to 10% (w / v), preferably 0.05 to 3% (w / v), and more preferably 0.1 to 1.5% (w / v).

[0049] Figure 1 is a process diagram showing an example of a method for producing distilled spirits using the present invention. First, raw materials containing grains and saccharifying enzymes are blended and appropriately pulverized (malting). The prepared raw materials are mixed with water and heated to saccharify the starch (saccharification). Yeast is added to the resulting saccharified liquid, and the resulting mash is fermented (fermentation). A photocatalyst-treated product is added to the fermented mash.

[0050] The mash containing the photocatalyst-treated product is distilled to obtain a distillate containing an ethanol fraction (distillation), and the obtained distillate is stored (storage).

[0051] In this method, the raw material to be photocatalytically treated is photocatalytically treated in a process separate from the distilled spirits production process. In the photocatalytic treatment, the raw material is contained in an aqueous liquid in an amount of 0.1 to 50% (w / v), preferably 0.5 to 20% (w / v), and more preferably 1 to 10% (w / v).

[0052] Figure 2 is a process diagram showing another example of a method for producing distilled spirits using the present invention. As shown here, the mash containing the aqueous liquid can be prepared by withdrawing a portion of the mash during fermentation, subjecting it to photocatalytic treatment, and then returning it to the mash just before distillation. The other steps are the same as those in the method of Figure 1.

[0053] Figure 3 is a process diagram showing another example of a method for producing distilled spirits using the present invention. As shown here, mash containing the above-mentioned aqueous liquid can be prepared by subjecting mash in the middle of fermentation to photocatalytic treatment. The other steps are the same as those in the method of Figure 1.

[0054] Figure 4 is a cross-sectional view showing an example of the structure of a reaction device used in photocatalytic treatment. This reaction device has a reaction vessel 1 filled with an aqueous liquid, a cooling unit 2 attached to the reaction vessel, an agitator 3 for agitating the aqueous liquid, and a light source 4 for irradiating the aqueous liquid. The reaction vessel 1 is filled with an aqueous liquid 5, and photocatalyst particles 6 are dispersed in the aqueous liquid 5. The light source 4 irradiates the catalytic reaction unit 7 with excitation light 8.

[0055] Specific examples of distilled alcoholic beverages include whiskey, shochu, brandy, and spirits such as gin, vodka, and rum. The distilled alcoholic beverage is particularly preferably whiskey. Among the characteristic aromas recognized in high-quality Scotch whiskey, there is a "green" aroma, and the green aroma is useful for producing whiskey with excellent palatability.

[0056] The mash containing the aqueous liquid containing the photocatalyst-treated product is preferably in a state where fermentation has been completed. If dried yeast is added to mash that has not yet been fermented, the amount of lipid peroxides may be reduced due to the metabolic action of the yeast.

[0057] The distillation of the mash containing the aqueous liquid may be carried out under the conditions normally used for distilling mash when producing distilled spirits. When the distilled spirit is malt whiskey, the distillation of the mash, i.e., the initial distillation, is usually carried out by maintaining the mash at the distillation temperature for 5 to 8 hours, depending on the capacity of the vessel. The distillation temperature of the mash is generally 70 to 100°C.

[0058] In the distillation process, the air inside the distiller is expelled from the system by heated steam, creating a substantially oxygen-free state.

[0059] The thermal decomposition of lipid peroxides produces linear saturated aliphatic aldehydes having 6 to 10 carbon atoms, and the production of linear saturated aliphatic aldehydes is accelerated by further heating in an oxygen-free environment. The produced linear saturated aliphatic aldehydes having 6 to 10 carbon atoms are volatile and may be released from the aqueous liquid. In such cases, the released linear saturated aliphatic aldehydes having 6 to 10 carbon atoms are dissolved and recovered by contacting them with a medium that dissolves them. Examples of the medium that dissolves the linear saturated aliphatic aldehydes having 6 to 10 carbon atoms include water and aqueous alcohol solutions. When the aqueous liquid is distilled, the linear saturated aliphatic aldehydes having 6 to 10 carbon atoms are recovered in the reflux liquid.

[0060] The recovered solution containing the linear saturated aliphatic aldehydes having 6 to 10 carbon atoms is an aromatic liquid having a green aroma. The aromatic liquid can be used as is or adjusted to a concentration that exhibits a more appropriate green aroma, for example, as a distilled liquor or flavoring. The distilled liquor of the present invention can be used alone or appropriately mixed with alcoholic beverages to produce distilled liquors and alcoholic beverages having a green aroma. The distilled liquor of the present invention has an enhanced green aroma. The flavoring of the present invention can be appropriately mixed with predetermined ingredients such as drinking water, sweeteners, alcohol, coloring, and carbon dioxide to produce soft drinks and alcoholic beverages having a green aroma. [Example]

[0061] Example 1 (Photocatalytic treatment of yeast) Dehydrated yeast (pressed yeast) for whiskey production and titanium oxide powder were suspended in distilled water. This mixture was adjusted to a predetermined temperature. The adjusted mixture was irradiated with excitation light while stirring at 10,000 rpm. After light irradiation, the mixture was centrifuged at 3,000 rpm for 10 minutes, and the solid contents were obtained as samples 1 to 4.

[0062] [Table 1]

[0063] Titanium oxide powder: "P25" (product name) manufactured by Nippon Aerosil Co., Ltd. Low-pressure mercury lamp: Heraeus GPH436T5 (trade name), 100 V, 21 W, central wavelength λ = 254 nm, light intensity I on sample surface = 20 mW / cm 2 Black light: Toshiba "FL40SBLB" (product name), 100 V, 40 W, central wavelength λ = 365 nm, light intensity I on the sample surface = 1.5 mW / cm 2

[0064] (whisky production) Ten grams of whiskey-making yeast (press yeast) was added to 4 L of wort with a specific gravity of 1.060, and fermentation was initiated at 23°C. The maximum temperature was controlled at 32°C and fermented for three days. After fermentation, the entire amount of solids was added to the mash. The entire mash, including the solids, was then distilled twice in a 5 L still to obtain whiskey. The resulting whiskey was analyzed for its green aldehyde concentrations (1-hexanal, 1-heptanal, 1-octanal, 1-nonanal, and 1-decanal). The analytical results are shown in Table 2.

[0065] [Table 2]

[0066] (1-hexanal analysis method) (1) Sampling 2.5 ml of ultrapure water and 0.5 ml of distilled liquid were placed in a headspace vial, and 75 μL of 63% EtOH water and 50 μL of internal standard solution (1-pentanal 2 ppm) were added, followed by measurement. The standard solution (STD) (1-hexanal 1.64 ppm) is mixed with 2.5 ml of ultrapure water and 0.5 ml of 63% EtOH water before use, but three types of additions of 25 μl, 50 μl, and 75 μl were prepared to create a calibration curve.

[0067] (2)Analysis conditions Equipment: Agilent HS7697A, GC6890N, MS5973 Headspace conditions: Loop size 3 ml Temperature (oven 60℃, loop 80℃, transfer line 120℃) Vial equilibration time: 10 min Loop equilibration time: 0.01 min Injection time 1min Injection conditions: Pulsed split (20:1), 250 kPa, gas saver 30 ml / min (2 min) Inlet temperature: 150℃ Column: VF-WAXms (Varian) 1 μm x 0.25 mm I.D. x 30 m Column flow rate: 1.2 ml / min (He, constant flow mode) Temperature rise conditions: 40℃ (10 min) → 10℃ / min → 240℃ (1 min) MS conditions: Temperature (transfer line 230°C, ion source 230°C, quadrupole 150°C)

[0068] [Table 3]

[0069] (1-heptanal, 1-octanal, 1-nonanal, 1-decanal analysis method) (1) Pretreatment 5 ml of the distillate is taken into a 50 ml centrifuge tube, 20 μl of IS (Octanal-d16 100 ppm) is added, and 20 ml of ultrapure water is added to dilute. The standard solution (STD) (50 ppm of each component) is mixed with 20 ml of ultrapure water, 5 ml of 63% EtOH water, and 20 μl of IS before use, but in order to create a calibration curve, three types of additions of 10 μl, 20 μl, and 30 μl were prepared. These test solutions are loaded onto a solid-phase column (Waters Oasis HLB 3cc, 60mg) that has been conditioned with ethyl acetate, methanol, and ultrapure water, and allowed to pass through at approximately 1 drop / sec. After passing the test solution, the column is washed with 10ml of ultrapure water and dried by suction for approximately 5 minutes. After drying, the solid phase is removed, the flow path is washed with acetone, dried, a dehydration cartridge (GL Science Inertsep Slim-J DRY) is set, the adsorbed solid phase is attached to it, and elution is performed into a quantitative test tube with 6ml of ethyl acetate. The eluate is concentrated to less than 0.5ml using nitrogen purging, and the volume is adjusted to 1ml with ethyl acetate, which is then subjected to GC / MS.

[0070] (2)Analysis conditions Equipment: Agilent GC6890N, MS5973 Injection conditions: Pulsed split (20:1), 250 kPa, gas saver 20 ml / min (2 min) Temperature 210℃, injection volume 1μl Column: Inert Pure WAX ​​(GL Science) 0.25 μm x 0.25 mm I.D. x 30 m Column flow rate: 1.2 ml / min (He, constant flow mode) Temperature rise conditions: 40°C (3 min) → 8°C / min → 120°C (2 min) → 12°C / min → 230°C (10 min) MS conditions: Temperature (transfer line 230°C, ion source 230°C, quadrupole 150°C)

[0071] [Table 4]

[0072] In principle, the higher the light intensity of a photocatalytic reaction, the faster the reaction rate. In the results in Table 2, comparing Test Area 1, which was irradiated with a mercury lamp with a short wavelength and high light intensity, with Test Area 3, which was irradiated with a black light with a long wavelength and low light intensity, the amounts of linear saturated aldehyde produced in both cases were about the same, and in fact Test Area 3 produced slightly more, which is not consistent with the principle of photocatalytic reaction.

[0073] The reason for this result is thought to be that although the catalytic reaction proceeded faster in Test Area 1 than in Test Area 3, the photodecomposition of fatty acids with 10 to 18 carbon atoms or lipid peroxides also proceeded more quickly, and the rate of this photodecomposition was much faster than the catalytic reaction.

[0074] <Example 2> (Photocatalytic treatment of yeast) 30 g of whiskey-making yeast (press yeast) and 1.08 g of titanium oxide powder were suspended in 270 ml of distilled water. This mixture was placed in a refrigerator and adjusted to 5°C. The adjusted mixture was irradiated with excitation light from a low-pressure mercury lamp (Heraeus GPH436T5, 100 V, 21 W) at 5°C for 120 hours while stirring at 10,000 rpm. After irradiation, the mixture was centrifuged at 3,000 rpm for 10 minutes to obtain a solid fraction.

[0075] (whisky production) Ten grams of whiskey-making yeast (press yeast) was added to 4 L of wort with a specific gravity of 1.060. Fermentation was initiated at 23°C, and the maximum temperature was controlled to 32°C for three days. After fermentation, the solids were added to the mash in an amount that resulted in the concentration (% (w / v)) shown in Table 5. The entire mash, including the solids, was then distilled twice in a 5 L still to obtain whiskey. The resulting whiskey was analyzed for its green aldehyde concentrations (1-hexanal, 1-heptanal, 1-octanal, 1-nonanal, and 1-decanal). The analytical results are shown in Table 5.

[0076] [Table 5]

[0077] <Sensory evaluation of whiskey> A panel of seven experts in distilled spirits conducted a sensory evaluation of the whiskeys produced in Examples 1 and 2. The evaluation scores were calculated as the average of the scores of five of the seven panelists, excluding one person from each of the top and bottom.

[0078] [Table 6]

[0079] [Table 7]

[0080] [Table 8] [Explanation of symbols]

[0081] 1...Reaction vessel, 2...Cooling section, 3...Agitator, 4...Light source, 5...aqueous liquid, 6...Photocatalyst particles, 7...catalytic reaction section, 8...Excitation light.

Claims

1. The method for producing a food or drink having a green aroma includes step A of photocatalytically treating a lipid containing a fatty acid having 10 to 18 carbon atoms to produce lipid peroxides, and step B of heating the photocatalytically treated product obtained in step A to produce a linear saturated aliphatic aldehyde having 6 to 10 carbon atoms.

2. 2. The method for producing a food or drink having a green aroma according to claim 1, wherein the lipid is derived from yeast cells.

3. 3. The method for producing a food or drink having a green aroma according to claim 1, wherein the lipid comprises a phospholipid of a fatty acid having 10 to 18 carbon atoms.

4. The method for producing a food or drink having a green aroma according to any one of claims 1 to 3, wherein the photocatalyst contains titanium oxide.

5. The method for producing a food or drink having a green aroma according to any one of claims 1 to 4, wherein step B is carried out in a substantially oxygen-free environment.

6. The method for producing a food or beverage having a green aroma according to any one of claims 1 to 5, wherein step B is carried out by distilling mash containing the photocatalyst-treated product.

7. The method for producing a food or drink having a green aroma according to any one of claims 1 to 6, wherein the food or drink is a distilled alcoholic beverage.

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