Method for manufacturing alcoholic beverages

Abstract

To provide a method for producing alcoholic beverage in which, even while reducing dissolved oxygen, the aroma of alcoholic beverage, especially the "ginjo (selected brewing) aroma" which is considered to be a preferable aroma for brewed sake such as sake, can be maintained.SOLUTION: The present invention is a method for producing alcoholic beverage, which is a method for producing alcoholic beverage having a step in which, using a degassing device including a hollow fiber membrane module, an alcoholic beverage is flowed in the liquid phase part of the hollow fiber membrane module and an inert gas-containing gas is flowed in the gas phase part at a pressure of atmospheric pressure or higher, where the gas in the gas phase part has a ratio of an oxygen partial-pressure of 120 mmHg or less and an inert gas partial-pressure of 640 mmHg or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing alcoholic beverages.

Background Art

[0002] Conventionally, it has been known that the generation and coloring of old fragrance, which is an unfavorable fragrance in alcoholic beverages, particularly fermented liquors, are derived from the oxidation of liquor components. Furthermore, in so-called raw liquor etc. where pasteurization treatment is not performed during filling, it contains about twice as much dissolved oxygen as ordinary pasteurized liquor, and it is known that the quality deterioration is faster than that of pasteurized liquor. Therefore, by reducing the dissolved oxygen concentration in alcoholic beverages to a reduced pressure state using a hollow fiber or film type degassing device, the oxidation of liquor components is suppressed, and it is known that the preferable quality during production can be maintained for a long time (see, for example, Patent Document 1). In addition, in order to obtain such an effect, it is desirable that the dissolved oxygen concentration in alcoholic beverages be as low as possible, for example, about 0.5 ppm or less. However, no specific comparative study data has been shown regarding the correlation between the dissolved oxygen concentration in alcoholic beverages and the preservability of preferable quality. Therefore, a method for manufacturing fermented liquors is provided, in which dissolved oxygen is depressurized and degassed using a membrane degassing device, or an inert gas is mixed in a continuous flow using an in-line mixer to reduce the dissolved oxygen, and the dissolved oxygen is suppressed within a specific concentration range, and the activities of enzymes in raw liquor are suppressed, thereby suppressing the deterioration of the taste and color of alcoholic beverages during long-term storage (see, for example, Patent Document 2).

Prior Art Documents

Non-Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when reducing the dissolved oxygen in alcoholic beverages while performing vacuum degassing or using an in-line mixer to reduce it, there was a problem that the aroma of the alcoholic beverages, particularly the "ginjo aroma" which is considered a favorable aroma in brewed alcoholic beverages such as sake, would disappear.

[0005] Therefore, the problem to be solved by the present invention is to provide a method for manufacturing alcoholic beverages that can retain the aroma of alcoholic beverages, particularly the "ginjo aroma" which is considered a favorable aroma in brewed alcoholic beverages such as sake, while reducing the dissolved oxygen.

Means for Solving the Problem

[0006] As a result of various studies, the inventors of the present application have found that the above problems can be solved by flowing an inert gas at a pressure equal to or higher than atmospheric pressure while reducing the dissolved oxygen in alcoholic beverages using a hollow fiber membrane module, and have thus arrived at the solution of the present invention.

[0007] That is, the present invention is a method for manufacturing alcoholic beverages having a step of flowing alcoholic beverages through the liquid phase portion of a hollow fiber membrane module and flowing a gas containing an inert gas at a pressure equal to or higher than atmospheric pressure through the gas phase portion using a degassing device equipped with a hollow fiber membrane module, characterized in that the gas in the gas phase portion has an oxygen partial pressure of 120 mmHg or less and an inert gas partial pressure of 640 mmHg or more.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a method for manufacturing alcoholic beverages that can retain the aroma of alcoholic beverages, particularly the "ginjo aroma" which is considered a favorable aroma in brewed alcoholic beverages such as sake, while reducing the dissolved oxygen in alcoholic beverages that would otherwise disappear when the dissolved oxygen in the alcoholic beverages is reduced.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail, but the present invention is not limited to only these embodiment examples. Also, in the method for manufacturing alcoholic beverages of the present invention, the steps until the production of raw liquor (new liquor) by brewing are well-known, and thus will be omitted. The raw liquor obtained through the brewing process preferably has a step of passing through a filtration device to remove microorganisms, fine particles, etc. remaining in the raw liquor (filtration step). The method for manufacturing alcoholic beverages of the present invention then has a step (deoxygenation step) of flowing the alcoholic beverage through the liquid phase part using a deaeration device equipped with a hollow fiber membrane module and flowing a gas containing an inert gas at a pressure equal to or higher than atmospheric pressure through the gas phase part. At that time, the gas in the gas phase part is treated at a ratio such that the oxygen partial pressure is 120 mmHg or less and the inert gas partial pressure is 640 mmHg or more. Thereafter, the alcoholic beverage, particularly the raw liquor, is transferred to a storage container and stored.

[0011] The filtration step is generally configured by two steps: filtration with activated carbon and filtration with a filter using a filtration device. First, by performing filtration with activated carbon, the aroma, taste, and color of the alcoholic beverage, particularly the raw liquor, in the subsequent steps are corrected, and subsequent deterioration is suppressed. Next, by performing filtration with a filter, microorganisms, fine particles, etc. that were not adsorbed by the activated carbon are removed. The filter used at this time preferably has a fineness such that it does not deteriorate the quality of the liquor and can remove microorganisms that cause contamination by miscellaneous bacteria, although it also depends on the balance with the filtration rate.

[0012] Next, the deoxygenation step is a step of sending the liquor obtained through the filtration step, preferably raw liquor, to a deaerator equipped with a hollow fiber membrane module and flowing it to the liquid phase side of the hollow fiber membrane module. At this time, while flowing a gas containing an inert gas at a pressure equal to or higher than atmospheric pressure at room temperature through the gas phase portion, the ratio of the gas in the gas phase portion is adjusted to an oxygen partial pressure of 120 mmHg or less and an inert gas partial pressure of 640 mmHg or more.

[0013] As the deaerator equipped with the hollow fiber membrane module that can be used in the present invention, a known one can be used. Examples of such a hollow fiber membrane module include an internal circulation type hollow fiber membrane module and an external circulation type hollow fiber membrane module. By using the module to flow the liquor through the liquid phase portion and flowing a gas containing an inert gas at a pressure equal to or higher than atmospheric pressure through the gas phase portion at the ratio of the gas, dissolved oxygen is deoxygenated from the liquor to the gas phase portion through the membrane. Among these, the external circulation type hollow fiber membrane module is superior in treatment efficiency to the internal circulation type hollow fiber membrane module and can suppress the liquid flow pressure loss to an extremely low level. It is particularly preferable when treating a large amount of liquor.

[0014] The hollow fiber membrane used in the hollow fiber membrane module used in the present invention is not particularly limited. For example, as long as the membrane structure has at least a skin layer (dense layer) and a layer having pores (porous layer) laminated thereon, those usually used as deaeration modules or intake modules can be used without limitation, and the following are more preferably used.

[0015] The material of the hollow fiber membrane used in the present invention is preferably a membrane made of a highly hydrophobic material. For example, polyolefin resins such as poly(4-methylpentene-1) resin are preferred. The membrane structure is not particularly limited as long as at least a skin layer (dense layer) and a layer having pores (porous layer) are laminated. Preferably, it is a heterogeneous membrane in which a skin layer (dense layer) and a support layer having pores (porous layer) are laminated. More preferably, it is a heterogeneous membrane in which a skin layer (dense layer) is laminated on the outside and a support layer having pores (porous layer) is laminated on the inside. The pore diameter of the pores is not particularly limited, but is preferably more than 0 nm, more preferably in the range of 0.1 nm or more, and preferably 100 nm or less, more preferably 50 nm or less.

[0016] When using such a heterogeneous membrane in which a skin layer and a support layer having pores are laminated, it is preferable because the resin odor can be reduced by contacting the liquid with the skin layer.

[0017] The hollow fiber membrane used in the hollow fiber membrane module of the present invention preferably has an oxygen permeation rate of the membrane of 0.1×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or more, more preferably 0.5×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or more, still more preferably 0.9×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or more, and preferably 5000×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or less, more preferably 500×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or less, still more preferably 100×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg].

[0018] The hollow fiber membrane used in the hollow fiber membrane module of the present invention preferably has a nitrogen permeation rate of the membrane of 1.0×10 -6 [cm 3 (STP) / cm 2 ·sec·cmHg] or more, more preferably 2.0×10 -6 [cm 3 (STP) / cm 2 ·sec·cmHg] or more, and preferably 200×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or less, more preferably 100×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or less, even more preferably 10×10 -5 [cm 3 (STP) / cm 2 ·sec·cmHg] or less. Selecting those within the above range is preferable because it is possible to improve the air supply performance of the module while suppressing the leakage of beverages.

[0019] Also, the hollow fiber membrane used in the hollow fiber membrane module of the present invention preferably has an oxygen-nitrogen separation coefficient α=(QO2: oxygen permeation amount) / (QN2: nitrogen permeation amount) in the range of 1 to 5, more preferably in the range of 1 to 4.5, and even more preferably in the range of 3.0 to 4.2. Within this range, it is preferable because it is possible to substantially prevent the permeation of alcoholic beverages and easily deaerate the dissolved oxygen amount to a predetermined range or fill the dissolved nitrogen amount to a predetermined range.

[0020] Note that the deaeration performance and nitrogen gas filling performance of the module generally improve as the oxygen permeation rate and nitrogen permeation rate of the diaphragm of the hollow fiber membrane increase. However, along with this, the liquid permeation rate also becomes large. Therefore, it is desirable to select a diaphragm with excellent balance between both characteristics.

[0021] In addition, the measurement of the oxygen permeation rate, nitrogen permeation rate, and the gas separation coefficient α can be easily carried out in accordance with ASTM-D1434.

[0022] In particular, a hollow fiber asymmetric membrane made of poly(4-methylpentene-1) resin is preferable because it has excellent gas permeability such as oxygen, nitrogen, and carbon dioxide gas, and high water vapor barrier properties. Regarding this asymmetric membrane, for example, it is described in detail in Japanese Patent Publication No. Sho 62-38250, Japanese Patent Publication No. Sho 62-54377, Japanese Patent Publication No. Hei 4-15014, Japanese Patent Publication No. Hei 4-50053, and Japanese Patent Application Laid-Open No. Hei 5-6656.

[0023] The structure of the module and the method of filling the hollow fiber membrane only need to be configured so that no uneven flow occurs in the water to be deaerated. For example, several suitable module structures are disclosed in Japanese Patent Application Laid-Open No. Hei 2-102714.

[0024] Regarding the dimensions of the hollow fiber membrane applied to the hollow fiber membrane module used in the present invention, the smaller the outer diameter of the hollow fiber membrane, the smaller the diameter of the wound body, and a larger membrane area can be obtained. Therefore, the outer diameter may preferably be in the range of 70 μm or more, more preferably 150 μm or more, and preferably 370 μm or less, more preferably 280 μm or less. On the other hand, the inner diameter of the hollow fiber membrane may preferably be 30 μm or more, more preferably 80 μm or more, and preferably 310 μm or less, more preferably 220 μm or less. The membrane area is not particularly limited, but preferably 0.018 m 2 or more, more preferably 0.18 m 2 or more, still more preferably 1.8 m 2 or more, particularly preferably 7.0 m 2 or more, and may preferably be in the range of 400 m 2 or less, more preferably 120 m 2 or less, still more preferably 40 m 2 or less, particularly preferably 20 m 2 or less.

[0025] The hollow fiber membrane module used in the present invention has the characteristics that it can easily suppress the cross-flow of liquors flowing through the liquid phase part, has excellent pressure resistance, a simple structure, and is easy to manufacture. There is no limitation on the form of the hollow fiber curtain-like sheet, and there is no particular limitation such as a non-woven fabric body, knitted fabric, woven fabric, etc., but preferably, it is a knitted fabric or a woven fabric formed by using a hollow fiber membrane as a weft or warp and using other yarns such as monofilament yarns or multifilament yarns made of polyester as the warp or weft. The sheet-like object organized in a curtain shape can be incorporated into the housing in a state of a laminate, a wound body, or a converged body. Also, an appropriate shape such as incorporating a three-dimensional structure in which the hollow fibers are spirally wound around a cylindrical core can be adopted.

[0026] In the deoxygenation step, from the viewpoint of being able to deoxygenate dissolved oxygen in a short time and having excellent productivity during liquor production, the treatment flow rate of liquor (liquid phase side) per hollow fiber membrane module is preferably in the range of 0.1 [L / min] or more, more preferably in the range of 1 [L / min] or more. On the other hand, from the viewpoint of the handleability of the module, the range of 100 [L / min] or less is preferable, and the range of 10 [L / min] or less is more preferable.

[0027] In the deoxygenation step, the liquor flowing through the liquid phase side in the hollow fiber membrane module is pressurized with a pump or the like, or placed in a storage container such as a tank, and pressurized with a gas containing an inert gas, preferably nitrogen gas, and then extruded from the storage container and introduced into the hollow fiber membrane module. The pressure when pressurizing the liquor is not particularly limited as long as it is in the range that gives the above-mentioned treatment flow rate. However, since deaeration can be performed in a short time, it is preferably pressurized in the range of 0.001 [MPa] or more as the lower limit value, and more preferably pressurized in the range of 0.01 [MPa] or more. On the other hand, from the viewpoint of excellent pressure resistance of the module, it is preferably pressurized in the range of 1.0 [MPa] or less as the upper limit value, more preferably pressurized in the range of 0.8 [MPa] or less, and even more preferably pressurized in the range of 0.3 [MPa] or less.

[0028] When the hollow fiber membrane module used in the deoxygenation process is of the internal circulation type, while maintaining the pressure outside the hollow fiber membrane (gas phase side) of the internal circulation type hollow fiber membrane module under reduced pressure, liquid is passed through the inside of the hollow fiber membrane (liquid phase side) for degassing. On the other hand, when the hollow fiber membrane module used in the degassing process is of the external circulation type, while maintaining the pressure inside the hollow fiber membrane (gas phase side) of the external circulation type hollow fiber membrane module under reduced pressure, liquid is passed through the outside of the hollow fiber membrane (liquid phase side) for degassing. In either case, it is preferable that the liquid phase side is the skin layer (dense layer) and the gas phase side is the layer with pores (porous layer).

[0029] There is no particular limitation on the temperature of the liquor during deoxygenation, but it is preferably 10°C or higher, more preferably 20°C or higher, and preferably 50°C or lower, more preferably 40°C or lower.

[0030] In the deoxygenation process, a gas containing an inert gas may be passed through the gas phase portion inside the hollow fiber membrane of the hollow fiber membrane module at a pressure equal to or higher than atmospheric pressure. Note that it is not necessary to dissolve (dissolve) the inert gas in the liquor, that is, the amount of dissolved nitrogen in the liquor may be 0.002 gas volumes or less.

[0031] The total pressure of the gas in the gas phase portion only needs to be equal to or higher than atmospheric pressure, and the upper limit value is not limited, but it is preferably 3 atm or lower, more preferably 2 atm or lower, and even more preferably 1.5 atm or lower. Note that in the present invention, when necessary, 1 atm (1 atm) 760 mmHg is used in terms of standard atmosphere conversion.

[0032] Among the gases in the gas phase portion, the proportion of oxygen (molecules) is 120 mmHg or less, preferably 80 mmHg or less, more preferably 40 mmHg or less, and the lower limit value is not defined, but may be substantially 0 mmHg or more. Note that "substantially 0 mmHg" means that except for the case where a small amount of oxygen remains due to the influence of the air remaining at the start-up and does not completely reach 0 mmHg, it means a state where oxygen is completely removed.

[0033] On one hand, among the gases in the gas phase, the proportion of the inert gas is 640 mmHg or more, preferably 700 mmHg or more, more preferably 760 mmHg or more in terms of the partial pressure of the inert gas, and although the upper limit is not defined, it may be substantially only the inert gas. Note that "only the inert gas" means that the total pressure and the partial pressure of the inert gas are equal, and "substantially only the inert gas" means that although there may be a case where the air remaining at the start-up remains and it does not become completely only the inert gas, excluding that case, it means a state where other gases (air) other than the inert gas are completely removed.

[0034] Here, examples of the inert gas include gases (molecules) composed of noble gas elements such as nitrogen gas (nitrogen molecules), helium, neon, and argon, and nitrogen gas is preferred.

[0035] In this way, by reducing the proportion (partial pressure of oxygen) of oxygen (molecules) among the gases in the gas phase and transferring the dissolved oxygen on the liquid phase side (in the liquor, preferably in the raw liquor) to the gas phase side, the reaction of oxidizing enzymes can be suppressed and the reaction with oxidizable substances can be inhibited. At that time, by setting the pressure of the gas phase part of the hollow fiber membrane module to a pressure of atmospheric pressure or higher, the aroma of the liquor (aroma), especially the "ginjo aroma" which is a preferred aroma in brewed liquors such as sake, can be retained.

[0036] The amount of dissolved oxygen in the liquor after the treatment in the deoxygenation step, preferably in the raw liquor, is not particularly limited, but is preferably in the range of 10 ppm or less, more preferably 4 ppm or less. Since a lower value is more preferable, the lower limit is not particularly limited, but it may be preferably in the range of 0.01 ppm or more, more preferably 0.5 ppm or more.

[0037] In the deoxygenation step, the flow rate of the gas on the gas side per hollow fiber membrane module may be appropriately adjusted within the range of 0.1 times to 10 times the flow rate of the liquid flowing through the set module, but it is preferably appropriately adjusted within the range of equal times to 3 times.

[0038] The pressure on the gas phase side may be adjusted by appropriately pressurizing with a pump or the like, but when the gas containing the inert gas is provided in a pressure vessel such as a cylinder, it is preferable to use the gas by reducing the pressure from the cylinder pressure via a pressure regulating valve and adjusting it to the required pressure as appropriate. In this case, it is sufficient that the outlet of the gas phase side of the hollow fiber membrane module is open to the atmosphere. On the other hand, the inlet is sufficient as long as it is at atmospheric pressure or higher, and although there is no upper limit, it is preferably 3 atm or lower, more preferably 2 atm or lower, and even more preferably 1.5 atm or lower. It is also preferable to flow the gas on the gas phase side (inside the hollow fibers) of the degassing module in the opposite direction to the flow on the liquid phase side.

[0039] FIG. 1 shows an example of an apparatus that can be used in the present invention, which is equipped with a hollow fiber membrane module, in which alcoholic beverages flow through the liquid phase and only nitrogen gas flows at atmospheric pressure through the gas phase.

[0040] First, the alcoholic beverage is supplied to a pressure-resistant tank 9 and stored while the temperature is appropriately adjusted. With the two-way valve 12 closed, nitrogen gas is supplied from the nitrogen tank 1 to the tank 9 through the gas piping 8 while the pressure is adjusted by the pressure regulating valve 7, thereby pushing out the alcoholic beverage stored in the tank 9. The alcoholic beverage is then guided to the liquid phase side of the deoxygenating hollow fiber membrane module 11 through the liquid passing piping 10a.

[0041] Next, while maintaining the state where the two-way valve 12 is closed, while adjusting the pressure of the pressure regulating valve 2 from the nitrogen tank 1 to atmospheric pressure, nitrogen gas is supplied to the gas phase side in the hollow fiber membrane module 11 through the nitrogen gas pipe 3 and the supply port 4, and the dissolved oxygen in the liquor passed through the liquid phase side of the hollow fiber membrane module 11 is deoxygenated. Note that it is not necessary to dissolve (dissolve) nitrogen gas in the liquor. For this reason, although the exhaust port 5 is normally open, the exhaust port 5 can also be closed to dissolve nitrogen gas. Furthermore, when a liquid component of the liquor condenses on the surface of the hollow fiber membrane, etc., by appropriately performing an opening / closing operation, the dew condensation can also be removed through the pipe 6. Note that a cooling device can also be provided for a part or all of each of the liquid passing pipes 10a and 10b. After a predetermined time has elapsed, the two-way valve 12 is opened, and the deoxygenated liquor can be stored in the storage container from the supply port 13.

[0042] The type of liquor in the present invention is not particularly limited. For example, it may be a beverage with an alcohol content of 1% or more, which can be diluted to a beverage with an alcohol content of 1% or more, or a powdery substance that can be dissolved to form a beverage with an alcohol content of 1% or more. It includes foaming liquors typified by beer and sparkling sake, fermented liquors typified by sake such as Japanese sake and fruit wines such as wine, distilled liquors typified by whiskey and shochu, and blended liquors. Among these, it is particularly preferable to apply it to "namazake" (liquors that have never been heat-treated at around 60°C called "hiire", especially a general term for Japanese sake) which is said to have a strong "ginjoshu (fruity-like)" aroma.

[0043] As described above, according to the production method of the present invention, not only can the amount of dissolved oxygen in the liquor be suppressed by the hollow fiber membrane module, but also the gas phase side is deoxygenated under the flow of a gas containing an inert gas at atmospheric pressure, so that the removal of the aroma can be suppressed. As a result, it is possible to make it difficult for the aroma, taste, and color to deteriorate. More preferably, the liquor (raw liquor) can retain the "ginjoshu" aroma, which is a preferable aroma, especially in fermented liquors such as sake.

Example

[0044] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples only.

[0045] (Measurement of Dissolved Gas) The amount of dissolved oxygen was measured using "B-506" manufactured by Iijima Electronics Co., Ltd.

[0046] (Method and Criteria for Sensory Evaluation) In this example, unless otherwise specified, the evaluation method was as follows. Regarding sensory evaluation, the aroma of fermentation (fruity-like) was evaluated. Note that the aroma of fermentation is defined as an evaluation that feels the same as that described by Hitoshi Utsunomiya, et al., "Quality Evaluation Terms and Standard Samples for Aroma in Sensory Evaluation Analysis of Sake", [online], 2006, National Research Institute of Brewing, page 3, Table 1 "Aroma of Fermentation, Fruity-like", search date July 7, 2020, http: / / www.nrib.go.jp / data / pdf / seikoumihou.pdf).

[0047] The results of the sensory evaluation were tabulated as the evaluation results of 5 panelists trained using standard samples (centrifuge tubes made of 50 ml polypropylene, each containing 3 g / liter of isoamyl acetate and 1.2 g / liter of ethyl caproate).

[0048] The intensity when perceiving the "aroma of fermentation, fruity-like" was evaluated in 6 levels: 1 (not felt), 2 (hardly felt), 3 (slightly felt), 4 (felt), 5 (strongly felt), 6 (very strongly felt). When the averaged value was 1 or more and less than 2, it was marked as ◎; when it was 2 or more and less than 3, it was marked as ○; when it was 3 or more and less than 4, it was marked as △; when it was 4 or more, it was marked as ×.

[0049] (Example 1) All of the hollow fiber membrane modules used were "EF-020G-A30" manufactured by DIC Corporation (hollow fiber membrane made of poly-4-methylpentene-1 resin having an asymmetric membrane with a skin layer (outer layer) and a porous layer (inner layer) with a hollow fiber pore diameter of 5 to 20 nm). Before the test, they were washed with ultrapure water for 72 hours and then dried with sterile air inside the modules. Furthermore, they were washed with raw water (23°C) for 3 minutes.

[0050] Using the manufacturing apparatus described in FIG. 1, deoxygenation treatment was carried out under a nitrogen gas flow. Prior to that, sake (manufactured by Gekkeikan Co., Ltd., "Junmai Daiginjo Nama Sake", dissolved oxygen gas concentration (DO value) before deaeration treatment: 8.5 ppm) was charged into tank 9. With the two-way valve 12 opened and the pressure valve 7 opened, sake was flowed from tank 9 at a flow rate of 4 L / min. Furthermore, on the gas phase side, while releasing the atmospheric pressure at the discharge port 5 side, nitrogen gas (purity 100%) was supplied from the air supply port 4 at a gas flow rate of 4 L / min to deoxygenate the sake inside the hollow fiber membrane module 15. Sensory evaluation of the obtained sake (DO value 0.8 ppm after deaeration treatment and nitrogen gas filling) was carried out. The sensory evaluation results are shown in Table 1.

[0051] (Comparative Example 1) Using the manufacturing apparatus described in FIG. 2, deoxygenation treatment was carried out under vacuum deaeration. Sake (manufactured by Gekkeikan Co., Ltd., "Junmai Daiginjo Nama Sake", dissolved oxygen gas concentration (DO value) before deaeration treatment: 8.5 ppm) was charged into tank 9. With the two-way valve 12 opened and the pressure valve 7 opened, sake was flowed from tank 9 at a flow rate of 4 L / min to the liquid phase side inside the hollow fiber membrane module 11. While operating the vacuum pump 16, the gas phase side inside the hollow fiber membrane module 11 was vacuum deaerated through the gas pipe 15 and the exhaust port 14 to perform deaeration treatment (absolute pressure 2.4 kPa) on the sake. Subsequently, the sake deoxygenated by the deaeration treatment was transferred to a container from the supply port 13 through the liquid flow pipe 10b. Sensory evaluation of the obtained sake (DO value 0.8 ppm after deaeration treatment and nitrogen gas filling) was carried out. The sensory evaluation results are shown in Table 1.

[0052] (Comparative Example 2) Using the manufacturing apparatus described in FIG. 3, liquor and an inert gas were flowed into the in-line mixer for stirring and mixing to deoxygenate the dissolved oxygen in the liquor. The sake (the dissolved oxygen gas concentration (DO value) before deaeration treatment was 8.5 ppm for "Junmai Daiginjo Nama Sake" manufactured by Gekkeikan Co., Ltd.) was charged into the tank 9 and extruded from the liquid feed pump 17 to the in-line mixer (manufactured by Noritake Company Limited) 18 at a flow rate of 430 liters per minute through the liquid feed pipe 10a. On the other hand, while adjusting the pressure with the pressure regulating valve 2 from the nitrogen tank 1, nitrogen gas was supplied to the in-line mixer 18 at 100 liters per minute through the gas pipe 3, and the sake and nitrogen gas were stirred and mixed. Thereafter, the liquor was extruded from the in-line mixer 18 to the receiving tank 19 through the liquid feed pipe 10b. After volatilizing nitrogen gas and oxygen gas (molecules) in the receiving tank, the deoxygenated sake was sent out by the liquid feed pump 17 from the receiving tank 19 through the liquid feed pipe 10c and transferred to the container from the supply port 13. The sensory evaluation of the obtained sake (DO value 0.8 ppm after deaeration treatment and nitrogen gas filling) was carried out. The sensory evaluation results are shown in Table 1.

[0053]

Table 1

[0054] From the above sensory evaluation analysis, in Comparative Example 1, deoxygenation was carried out by vacuum deaeration treatment using a hollow fiber membrane module, and as a result of reducing the dissolved oxygen, "brewing aroma, fruit-like" decreased. Also, in Comparative Example 2, deoxygenation was carried out by stirring and mixing with nitrogen gas using an in-line mixer, and as a result of reducing the dissolved oxygen, "brewing aroma, fruit-like" decreased. In contrast, in Example 1, the deoxygenation of sake was carried out by flowing only nitrogen gas (with a low oxygen partial pressure) on the gas phase side of the hollow fiber membrane module under atmospheric pressure. As a result, while reducing the dissolved oxygen, it was possible to suppress the decrease in "brewing aroma, fruit-like".

Explanation of reference numerals

[0055] 1 Nitrogen tank (high-pressure container) 2 Pressure regulating valve 3 Nitrogen gas supply port side pipe 4 Nitrogen gas supply port 5 Nitrogen gas discharge port 6 Nitrogen gas outlet side piping 7 Pressure regulating valve 8 Nitrogen gas piping 9 Tank (pressure-resistant storage container) 10a Liquid supply piping 10b Liquid supply piping 11 Hollow fiber membrane module 12 Two-way valve 13 Supply port P1 Pressure gauge P2 Pressure gauge F1 Flow meter 14 Exhaust port 15 Gas phase side piping 16 Vacuum pump P3 Pressure gauge 10c Liquid supply piping 17 Liquid transfer pump 18 In-line mixer 19 Receiving tank

Claims

1. Using a degassing device equipped with a hollow fiber membrane module, flowing liquor through the liquid phase part of the hollow fiber membrane module and flowing a gas containing an inert gas at a pressure equal to or higher than atmospheric pressure through the gas phase part, a method for producing liquor comprising the steps of: wherein the gas in the gas phase part in the above step has a ratio of an oxygen partial pressure of 120 mmHg or less and an inert gas partial pressure of 640 mmHg or more, wherein the liquor is a brewed liquor, wherein the inert gas is nitrogen gas, wherein the total pressure of the gas in the gas phase part is equal to or higher than atmospheric pressure and 1.5 atmospheres or less, and a method for producing liquor, characterized in that the amount of dissolved nitrogen in the liquor obtained through the above step is 0.002 gas volume or less.

2. The method for producing liquor according to claim 1, wherein the amount of dissolved oxygen in the liquor obtained through the above step is in the range of 10 ppm or less.

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