Bactericidal treatment method, method for producing brewed liquor, and brewed liquor production system

Abstract

To provide a bactericidal method that can apply sufficient bactericidal treatment in the process of producing brewed liquor like sake.SOLUTION: A bactericidal treatment method applies pressure to the liquid under treatment, including brewed liquor, to form a pressurized fluid. This method then applies collision force to the pressurized fluid, thereby subjecting the liquid under treatment to bactericidal treatment.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a sterilization method, a brewed alcohol production method, and a brewed alcohol production system. [Background technology]

[0002] Sake, a type of brewed alcoholic beverage, is produced through various steps, including raw material processing, koji making, yeast starter, mash, refining, storage, and bottling. For example, in the raw material processing process, brown rice is polished, washed, soaked, and then steamed in a rice steamer. Next, in the koji making process, the steamed rice and seed koji are used to make koji in a koji room. This koji is then mixed with steamed rice, water, and purely cultured yeast to create the starter yeast that will become the basis of sake. This starter yeast is then transferred to a fermentation tank, where koji, steamed rice, and water are added and fermented to create mash, which is then matured. Once the mash has fully matured, it is pressed in a pressurizing machine, and separated into lees and new sake, which is then produced. After the new sake has gone through the above processes, it is filtered to remove impurities, and pasteurized in a pasteurization machine to sterilize the yeast and hiochi bacteria and inactivate any remaining enzymes, stabilizing the quality of the sake, before moving on to the storage and bottling processes to produce sake.

[0003] Among the above processes, pasteurization is performed when the quality of the new sake that has been filtered through the pressurized tank has settled. This pasteurization sterilizes the microorganisms in the new sake and inactivates the enzymes remaining in the new sake, stabilizing the sake. At this time, the aroma and mouthfeel unique to new sake are lost due to pasteurization. The pasteurization time must be set appropriately, taking into consideration the set quality of the sake and the degree of maturation of the sake. Furthermore, the pasteurization temperature must be set at 60°C or higher to completely sterilize the hiochi bacteria, and the pasteurization process must be performed for at least a few minutes. The pasteurization method also requires complicated procedures, such as keeping the sake from coming into contact with air as much as possible to prevent oxidation of the sake by oxygen, and any mistakes in these procedures can have a significant impact on the quality of the sake.

[0004] Therefore, as an alternative sterilization method to complicated heat sterilization treatments such as pasteurization, Patent Document 1 proposes an ultra-high pressure treatment method in which brewed alcohol is treated at a temperature of 60°C or less and at an ultra-high pressure of 300 MPa or more to sterilize microorganisms contained in the brewed alcohol and inactivate enzymes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-217758 Summary of the Invention [Problem to be solved by the invention]

[0006] However, even the ultra-high pressure treatment method of Patent Document 1 has limitations in its sterilization ability and has not yet been put to practical use.

[0007] In view of the above, the present invention has been made in consideration of the above, and aims to provide a sterilization method capable of performing sufficient sterilization treatment in the process of producing brewed alcoholic beverages such as sake. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and have found that sufficient sterilization can be achieved by applying additional shear force to a fluid under pressure during sterilization, thereby completing the present invention.

[0009] [1] A sterilization method comprising applying pressure to a liquid body to be treated, which contains brewed alcohol, to turn it into a pressurized fluid, and applying a collision force to the pressurized fluid to sterilize the liquid body to be treated. [2] The sterilization method described in [1], wherein the collision force is generated by colliding the pressurized fluid with a hard material, or by each of the pressurized fluids sprayed from at least a pair of nozzles colliding with each other. [3] The sterilization method according to [1], wherein the collision force is applied within a slit chamber. [4] The sterilization method according to any one of [1] to [3], which is carried out in a closed circuit in a circulatory manner. [5] The sterilization method according to any one of [1] to [4], wherein the pressure is 100 to 300 MPa. [6] The sterilization method according to [4] or [5], wherein the number of circulations is two or more. [7] The sterilization method according to any one of [1] to [6], which is carried out at a temperature of less than 60°C. [8] A method for producing brewed alcohol, comprising: a brewing process in which a brewed alcohol raw material is fermented to produce brewed alcohol; and a sterilization process in which pressure is applied to a liquid body to be treated that contains the brewed alcohol to produce a pressurized fluid, and a collision force is applied to the pressurized fluid to sterilize the liquid body to be treated. [9] A method for producing brewed alcohol described in [8], which is carried out at less than 60°C.

[10] A brewing means for fermenting a brewed alcoholic beverage raw material to produce a brewed alcoholic beverage; a sterilization means for applying pressure to the liquid body to be treated that contains the brewed alcohol to turn it into a pressurized fluid, and applying a collision force to the pressurized fluid to sterilize the liquid body to be treated.

[11] The brewed beverage production system described in

[10] , wherein the sterilization means has a chamber for applying a collision force to the pressurized fluid and an injection nozzle for injecting the pressurized fluid into the chamber.

[12] The brewed beverage production system according to

[11] , wherein at least the contact surface of the injection nozzle with the pressurized fluid is made of a diamond-based material. Effect of the Invention

[0010] According to the present invention, a sterilization method capable of carrying out a sufficient sterilization treatment in the process of producing brewed alcoholic beverages such as sake can be provided. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram showing an example of a ball collision chamber. [Diagram 2]FIG. 2 is a schematic diagram showing an example of a collision chamber in which pressurized fluids collide with each other. [Diagram 3] FIG. 2 is a side view showing an example of a slit chamber of the present embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing an example of an upstream nozzle 4 and a downstream nozzle 5 of a slit chamber. [Diagram 5] FIG. 13 is a cross-sectional view showing (a) a first modified example of the slit chamber, (b) a second modified example of the slit chamber, and (c) a third modified example of the slit chamber. [Figure 6] FIG. 1 is an explanatory diagram illustrating sterilization in a closed circuit. [Figure 7] 1 is a photograph showing a treated medium. [Figure 8] 1 is a photograph showing a treated medium. [Figure 9] FIG. 13 is a diagram showing the results of qualitative analysis of the treated product by gas chromatography. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention relates to a sterilization method, a brewed alcohol production method, and a brewed alcohol production system. In this specification, sterilization refers to the sterilization of various microorganisms that naturally exist in the raw materials for brewed alcohol (water, rice koji, etc.), or the sterilization of various microorganisms that are used or mixed into the brewed alcohol production process, and refers to killing the microorganisms or rendering them unable to grow.

[0013] In the present invention, examples of the microorganisms to be sterilized include at least one of yeast, bacteria, and mold.

[0014] Specifically, examples of yeasts that can be used for sake include a group of strains of Saccharomyces cerevisiae known as sake yeasts, which have excellent brewing characteristics, and wild yeasts (Saccharomyces cerevisiae) that are mixed into the product during the brewing process, such as Saccharomyces cerevisiae K701, Saccharomyces cerevisiae K901, Saccharomyces cerevisiae K1401, and Saccharomyces cerevisiae K1801.

[0015] Examples of bacteria include lactic acid bacteria known as "hiochi bacteria," such as Lactobacillus fructivorans S-14, Lactobacillus homohiochii S-24, Lactobacillus kasei H-7, and Lactobacillus hilgardii H-34.

[0016] Examples of mold include Aspergillus oryzae (Ahlburg) Cohn, and Rhizopus stronifer (Ehrenberg: Fr.) Vuillemin, which is used in East Asia other than Japan.

[0017] In the present invention, it is preferable to sterilize at least one type of hiochi bacteria.

[0018] Hereinafter, one embodiment of the present invention (the present embodiment) will be described. [Sterilization method] The sterilization method according to this embodiment applies pressure to a liquid body to be treated that contains brewed alcohol to produce a pressurized fluid, and applies a collision force to this pressurized fluid to sterilize the liquid body to be treated.

[0019] In this embodiment, a collision force is applied to the liquid material to be treated, which has become a pressurized fluid, and a shear force due to the collision is generated in addition to the pressure applied to the fluid. In other words, it is presumed that the liquid material to be treated is subjected to a sufficient sterilization treatment that cannot be obtained by pressurization alone, as a result of the pressure and shear force acting on the liquid material. In addition, since heating such as pasteurization is not required, the true flavor of the brewed sake is not lost and good sake quality can be maintained. Therefore, the sterilization method according to this embodiment is expected to be an effective sterilization method that can replace pasteurization.

[0020] Furthermore, for example, problems have been pointed out regarding the pasteurization process (sterilization process) of sake, such as the production of the carcinogenic substance ethyl carbamate and the loss of the flavor unique to unpasteurized sake.

[0021] Ethyl carbamate is a carcinogen classified as Group 2A (probably carcinogenic to humans) by the International Agency for Research on Cancer (IARC) in 2007, and is found at an average of 47 ppb in regular commercially available sake products, and an average of 183 ppb in aged sake or long-aged sake.

[0022] Currently, the National Tax Agency and the National Research Institute of Brewing are working together to implement measures in Japan, but the content of ethyl carbamate has already been regulated in Canada and the Czech Republic, making this a cause for concern when exporting sake overseas.

[0023] Ethyl carbamate is presumably produced by a chemical reaction between urea and ethyl alcohol contained in sake during the aging period and pasteurization process (for example, heating for 10 minutes at 60-65°C), and it is said that the amount produced can be reduced by lowering the pasteurization temperature or shortening the time. However, lowering the heating temperature or shortening the heating time naturally raises concerns that sterilization may not be sufficient. In contrast, in the sterilization method according to the present embodiment, sterilization is performed using pressure and shear force, so that the production of ethyl carbamate caused by heating can be suppressed.

[0024] Furthermore, sake that has not been pasteurized is called "namazake" and is characterized by its fresh taste, but the aroma and flavor are easily affected by residual enzymes and microorganisms and are therefore prone to change, making it difficult to store for long periods of time or to export overseas.

[0025] As mentioned above, residual enzymes and microorganisms are inactivated and killed by pasteurization, making it possible to store the sake for a long time, but the pasteurization process causes the sake to lose its characteristic flavor. Generally, sake sold on the market is pasteurized twice during production before being shipped.

[0026] In contrast, the sterilization method according to the present embodiment can sterilize well without the pasteurization process, so that the characteristic fresh flavor of various types of unpasteurized sake, such as unpasteurized sake, unpasteurized sake, and unpasteurized sake, is not lost. In addition, it can be stored for a long time.

[0027] There are various methods for applying a collision force to the pressurized fluid. For example, it is preferable to use a chamber having a configuration for applying a collision force to the pressurized fluid, such as a collision chamber for causing the pressurized fluid to collide with a hard material (e.g., a hard ball), a collision chamber for causing pressurized fluids to collide with each other, or a slit chamber for subjecting the liquid to sterilization treatment by compression, shear, turbulence, etc. while passing through a narrowed flow path (slit), as the chamber to be loaded into the high-pressure injection treatment device.

[0028] Here, the various chambers will be described. First, the chamber shown in Fig. 1 is a schematic configuration of an impact chamber 10 (also called a ball impact chamber) that impacts a pressurized fluid against a hard material (e.g., a hard ball). In the impact chamber 10, pressurized fluid A, which is applied with pressure to a liquid material to be treated that contains brewed alcohol, is accelerated from one nozzle 12 and impacted against a hard ball 14, applying a collision force to the pressurized fluid and sterilizing the liquid material to be treated. After the sterilization process, the liquid material to be treated is discharged from an outlet 16.

[0029] The hard ball 14 is preferably a ceramic ball made of silicon nitride or the like. The contact surface of the nozzle 12 with the pressurized fluid is preferably made of a diamond-based material. Examples of diamond-based materials include single crystal diamond, sintered diamond, industrial diamond, and DLC film. By using a diamond-based material, corrosion and deterioration of the device can be suppressed, and durability can be improved.

[0030] It is presumed that the high sterilization ability is exerted by the shear force when the pressurized fluid A passes through the nozzle 12, the cavitation impact force due to submerged injection, and the impact force when the pressurized fluid collides with the hard ball 14.

[0031] 2 is a schematic diagram of a collision chamber 20 (also called an opposed collision chamber) in which pressurized fluids collide with each other. In the collision chamber 20, the pressurized fluid A, which is accelerated and sprayed from a pair of opposed nozzles 22, 23, is collided with each other (oblique collision) to apply a collision force to the pressurized fluids A, thereby sterilizing the liquid to be treated. After the sterilization, the liquid to be treated is discharged from an outlet 26.

[0032] The collision angle θ during the collision may be an acute angle as shown in FIG. 2, but may also be a 180° head-on collision. In the case of the collision chamber 20, the contact surfaces of the nozzles 22 and 23 with the pressurized fluid A are preferably made of a diamond-based material. Examples of diamond-based materials include single crystal diamond, sintered diamond, industrial diamond, DLC film, etc. By using a diamond-based material, corrosion and deterioration of the device can be suppressed, and durability can be improved.

[0033] It is presumed that the high sterilization ability is exerted by the shear force when the pressurized fluid A passes through the nozzles 22, 23, the cavitation impact force due to submerged injection, the impact force when the pressurized fluids A collide with each other, and the shear force due to the increase in relative velocity of the opposing jets.

[0034] Alternatively, a slit chamber may be used in which the direction of travel (trajectory) of the pressurized fluid is changed at a right angle within the nozzle flow path to apply a collision force, and the flow path thereafter is narrowed in diameter, and the liquid to be treated is subjected to sterilization treatment by compression, shear, turbulence, etc. while passing through the narrowed flow path (slit). The slit chamber generates stronger shear forces than the impingement chamber, and can perform sterilization more reliably. The slit chamber may have a configuration as described in, for example, JP-A-2022-63686.

[0035] Specifically, as shown in FIG. 3, the slit chamber 30 receives pressurized fluid from the inlet side (IN) to the outlet side (OUT), and comprises a chamber flow path 32, a chamber body 33 connected to the chamber flow path 32, and an upstream nozzle 34, a downstream nozzle 35, a load-receiving nozzle 37, and an injection port 38 arranged within a fixed groove 33a of the chamber body 33.

[0036] As shown in FIG. 4(a), the upstream nozzle 34 is a member having a shape of a partially cut-out disk, and has first and second upstream water guide holes 49a, 49b on the left and right in a cross-sectional view. As shown in FIG. 4(b), the downstream nozzle 35 is a member having a shape of a partially cut-out disk, and has first and second downstream water guide holes 50a, 50b on the top and bottom in a cross-sectional view. As shown in FIG. 4(c), the load-receiving nozzle 37 has two holes that are slightly larger than the first and second downstream water guide holes 50a, 50b at the same positions as the first and second downstream water guide holes 50a, 50b. The first and second downstream water guide holes 50a, 50b are not limited to being circular, and may be various combinations such as elliptical or straight shapes. It is preferable to use a material with high hardness, such as superhard or the diamond-based material described above, for the upstream nozzle 34, downstream nozzle 35, and load-receiving nozzle 37.

[0037] The downstream nozzle 35 has an auxiliary flow passage 51a connecting the first and second downstream water guide holes 40a, 40b, and a flow passage 52a that is perpendicular to the auxiliary flow passage 51a and communicates with the first and second upstream water guide holes 49a, 49b. The flow passage 52a can be set according to the shapes of the first and second upstream water guide holes 49a, 49b, and can be adjusted according to the purpose of the material treatment. The pressurized fluid supplied to the chamber flow passage 32 passes through the first and second upstream water guide holes 49a, 49b and collides with the inlet end face of the downstream nozzle 35. The pressurized fluid then passes through the flow passage 52a, the auxiliary flow passage 51a, and the first and second downstream water guide holes 50a, 50b, and is sprayed from the spray port 38.

[0038] In addition, the width in the left-right direction in a cross-sectional view of auxiliary flow path 51a can be set to be smaller than the width in the up-down direction in a cross-sectional view of flow path 52a. After the pressurized fluid passes through first and second upstream water guide holes 49a, 49b and collides with the inlet end face of downstream nozzle 35, it moves at a right angle and passes through flow path 52a whose diameter has been reduced.

[0039] When the sterilizer is started up, the flow of pressurized fluid filling the internal space near the first and second upstream water guide holes 49a, 49b may be temporarily disturbed, but as the pressurized fluid continues to be sprayed from the nozzle 38, the turbulence in the internal space disappears and the flow is adjusted.

[0040] In addition, the depth of the flow path 52a can be set to be smaller than the depth of the auxiliary flow path 51a, which can promote the improvement of the sterilization performance when the diameter is reduced or expanded as described above.

[0041] The width in the vertical direction in a cross-sectional view of the flow path 52a can be set smaller than the diameters of the first and second upstream water guide holes 49a, 49b, which can promote the improvement of the sterilization performance when the diameter is reduced or expanded as described above.

[0042] In addition, it is also conceivable to perform a surface treatment on the inside of the auxiliary flow path 51a or the flow path 52a, or to make the flow paths uneven.

[0043] A modified example of the slit chamber 30 will be described below with reference to FIG.

[0044] In the optimal embodiment, similar to the configuration described above, the downstream nozzle 35 is provided with an auxiliary flow path 51a, a flow path 52a, a first downstream water guide hole 50a, and a second downstream water guide hole 50b, which are connected to the first and second upstream water guide holes 49a, 49b in the upstream nozzle 34.

[0045] As a first modified example, as shown in FIG. 5(a), the configuration in which flow path 52a of downstream nozzle 35 is arranged so as to communicate with first and second upstream water guide holes 49a, 49b in upstream nozzle 34 in the optimal embodiment is changed to a configuration in which a second flow path 52b is formed in downstream nozzle 35.

[0046] According to this configuration, the presence of two flow paths 52a, 52b that most effectively sterilize the pressurized fluid allows twice as much pressurized fluid to be treated.

[0047] As a second modified example, as shown in Figure 5(b), the configuration in the optimal embodiment in which flow path 52a of downstream nozzle 35 is arranged so as to communicate with first and second upstream water guide holes 49a, 49b in upstream nozzle 34 is changed to a configuration in which a second flow path 52b and further third and fourth upstream water guide holes 49c, 49d are formed in downstream nozzle 5.

[0048] According to this configuration, the presence of two flow paths 52a, 52b that most effectively sterilize the pressurized fluid allows twice as much pressurized fluid to be treated. In the first modified example, the pressurized fluid passing through the upstream water guide holes 49a, 49b is branched for sterilization, but in the second modified example, the addition of the third and fourth upstream water guide holes 49c, 49d makes it possible to supply an equal amount of pressurized fluid to each of the flow paths 52a and the second flow path 52b.

[0049] As a third modified example, as shown in Figure 5(c), the configuration in the optimal embodiment in which a flow path 52a of the downstream nozzle 35 is arranged so as to communicate with the first and second upstream water guide holes 49a, 49b of the upstream nozzle 34, and further in which an auxiliary flow path 51a is formed in the downstream water guide holes 50a, 50b of the upstream nozzle 34, is changed to a configuration in which third and fourth downstream water guide holes 50c, 50d and a second auxiliary flow path 51b are formed in the downstream nozzle 35, and an upstream water guide hole 49c is formed in the upstream water guide holes 49a, 49b of the upstream nozzle 34.

[0050] According to this configuration, by forming the third and fourth downstream water guide holes 50c, 50d and the second auxiliary flow path 51b, the pressurized fluid passes through more smoothly, making it possible to adjust the processing flow rate of the pressurized fluid and also preventing unnecessary clogging, etc.

[0051] Although the best mode embodiment and the first to third modified examples have been illustrated, it goes without saying that in addition to these configurations, by changing the number of upstream water holes and downstream water holes, or the number of auxiliary flow paths and flow paths, it is possible to increase the throughput of finished products and improve work efficiency.

[0052] In this embodiment, as a method that is expected to have a higher sterilizing power, a method of applying a collision force in a chamber is preferred. Among them, a ball collision chamber in which the collision force is generated by colliding a pressurized fluid with a hard material, or an opposing collision chamber in which the pressurized fluids sprayed from at least a pair of nozzles collide with each other, or a slit chamber in which the collision force is applied in a slit chamber are more preferred. Among them, a method using a slit chamber is even more preferred.

[0053] Examples of such a chamber include various chambers of a wet type pulverization device named "Star Burst" manufactured by Sugino Machine Ltd.

[0054] The pressure (jetting pressure) for making the fluid into a pressurized fluid is preferably 100 to 300 MPa, more preferably 100 to 245 MPa, from the viewpoint of ensuring impact force and sterilizing ability, and the jetting speed is preferably 400 to 700 m / s.

[0055] The sterilization method according to this embodiment is preferably carried out in a closed circuit that allows circulation, thereby making it possible to circulate the liquid material to be sterilized multiple times (two or more passes). For example, as shown in Fig. 6, it is preferable to have a closed circuit that can circulate, which is composed of a raw material tank 80 that stores the liquid to be treated including brewed alcohol, a liquid supply pump 82 that pressure-feeds the liquid to be treated from the raw material tank 80, a pressure booster 84 that pressurizes the liquid to be treated pressure-fed from the liquid supply pump 82, an ultra-high pressure filter 86, a chamber 87 that sterilizes the pressurized liquid to be treated (pressurized fluid A), a heat exchanger 88, etc., and in which the liquid to be treated after sterilization is taken out of the system by switching a valve 89, etc., or is supplied to the raw material tank and sterilized again. By making it a closed circuit, it is possible to prevent bacteria from being mixed in from the outside. Furthermore, such an effect can be obtained when the final liquid to be treated is filled into a container. In addition, a highly sealed environment can be realized by disposing an elastic member at the connection between each element in the closed circuit. Also, by disposing multiple sensors in the closed circuit, it is possible to detect the condition of the liquid to be treated (for example, temperature, viscosity, amount of bacteria, etc.), thereby creating an environment that is less likely to cause quality deterioration.

[0056] From the viewpoint of further improving the sterilization effect, the circulation is preferably performed twice or more, and more preferably from 2 to 10 times.

[0057] In the above sterilization treatment, in this embodiment, it is preferable to carry out the sterilization method according to this embodiment using a wet type atomization device (including a laboratory machine) using a water jet manufactured by Sugino Machine Co., Ltd. The wet type atomization device is configured so that the chamber can be appropriately replaced, and also forms a closed circuit.

[0058] Moreover, the sterilization method according to this embodiment is preferably carried out at less than 60°C, and more preferably at 40 to 55°C. Good sake quality can be maintained by avoiding high temperatures as much as possible and treating for a short period of time. The temperature can be kept below 60°C by using a water jet manufactured by Sugino Machine Ltd. using the above-mentioned chamber. The temperature referred to here refers to at least the temperature of the liquid being treated that is being sterilized.

[0059] [How brewed alcohol is produced] The method for producing brewed alcohol in this embodiment includes a brewing process in which a brewed alcohol raw material is fermented to produce brewed alcohol, and a sterilization process in which pressure is applied to a liquid body to be treated that contains the brewed alcohol to produce a pressurized fluid, and a collision force is applied to this pressurized fluid to sterilize the liquid body to be treated.

[0060] (Brewing process) The brewing process is a process in which raw materials for brewed alcohol are fermented to produce brewed alcohol. The various treatments and conditions in the brewing process can be appropriately selected from the various treatments and conditions applied to the production of brewed alcohol such as sake.

[0061] (sterilization process) The sterilization step is a step in which pressure is applied to the liquid material to be treated, which contains brewed alcohol, to produce a pressurized fluid, and a collision force is applied to the pressurized fluid to sterilize the liquid material to be treated. The sterilization method in this step is the same as that in the embodiment described above. A plurality of sterilization steps may be provided.

[0062] The method for producing brewed alcohol according to this embodiment is preferably carried out at less than 60°C, and more preferably at 40 to 55°C. By keeping the temperature below 60°C, an operation such as pasteurization is not necessary. Furthermore, good quality of the alcohol close to that of unpasteurized sake can be maintained. For this reason, it is preferable that the method for producing brewed alcohol according to this embodiment does not include a step of pasteurization.

[0063] The method for producing brewed alcohol according to this embodiment preferably includes appropriate known general steps that are applied to the production of sake.

[0064] [Brewing and Alcohol Production System] The brewed alcohol production system of this embodiment includes a brewing means for fermenting brewed alcohol raw materials to produce brewed alcohol, and a sterilization means for applying pressure to a liquid body to be treated that contains the brewed alcohol to produce a pressurized fluid, and for applying a collision force to this pressurized fluid to sterilize the liquid body to be treated.

[0065] In the brewed alcohol production system according to this embodiment, the sterilization means preferably comprises a chamber for applying a collision force to the pressurized fluid, and a nozzle for injecting the pressurized fluid into the chamber.

[0066] An example of the above-mentioned sterilization means is a wet type atomization device using a water jet manufactured by Sugino Machine Ltd., suitably incorporating a chamber manufactured by Sugino Machine Ltd.

[0067] At least the surface of the nozzle that comes into contact with the pressurized fluid is preferably made of a diamond-based material. Examples of diamond-based materials include the materials described above. By using a diamond-based material, corrosion and deterioration of the device can be suppressed and durability can be improved.

[0068] As the brewing means for fermenting the brewed alcohol raw material to produce the brewed alcohol, any known brewing means that is used in the production of brewed alcohol such as sake can be appropriately adopted. EXAMPLES

[0069] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these. All treatments were carried out at room temperature (approximately 25° C.) unless otherwise specified.

[0070] [Example 1] (Confirmation test of bactericidal effect) The liquid material to be treated (raw material) was sterilized under the following conditions using a wet atomization device (Starburst Lab) manufactured by Sugino Machine Co., Ltd., and the treated product was cultured after sterilization to confirm the presence or absence of a sterilizing effect. The results are shown in the table below. The temperature of the liquid material to be treated in the sterilization treatment using the wet-type atomization device was 55° C. or lower.

[0071] Ingredients: Sake made by adding yeast or hiochi bacteria to sake (commercially available unpasteurized sake) Processing volume: 700mL / 1 condition Injection pressure: 200MPa Number of passes: 1 to 3 passes Chamber: Ball impact chamber or slit chamber (both manufactured by Sugino Machine Co., Ltd.) Yeast (Kyokai yeast): The following four types Saccharomyces cerevisiae K701 Saccharomyces cerevisiae K901 Saccharomyces cerevisiae K1401 Saccharomyces cerevisiae K1801 Hiochi bacteria: the following four types Lactobacillus fructivorans S-14 Lactobacillus homohiochii S-24 Lactobacillus kasei H-7 Lactobacillus hilgardii H-34

[0072] [Table 1]

[0073] A photograph of the treated medium (S-24) is shown in Figure 7. From the photograph and Table 1, it was found that sterilization was achieved in two passes using the ball impact chamber and in one pass using the slit chamber.

[0074] [Table 2]

[0075] A photograph of the treated medium (K901) is shown in Figure 8. From the photograph and Table 2, it can be seen that sterilization was achieved in one pass in both chambers.

[0076] (Test to confirm the effect of reducing the amount of ethyl carbamate produced) The liquid to be treated (raw material) was sterilized under the conditions below using a wet atomization device (Starburst Lab) manufactured by Sugino Machine Ltd., and the treated product after sterilization was cultured to confirm whether or not ethyl carbamate was produced. For comparison, the raw material was also heated twice in a water bath at 63℃ for 10 minutes to check for the generation of ethyl carbamate. The presence or absence of ethyl carbamate was confirmed by mass spectrometry using gas chromatography for the treated product. The results are shown in Figure 9.

[0077] Ingredients: Sake made by adding urea to sake (commercially available unpasteurized sake) Processing volume: 700mL / 1 condition Injection pressure: 200MPa Number of passes: 4 Chamber: Ball impact chamber or slit chamber (both manufactured by Sugino Machine Co., Ltd.)

[0078] [Example 2] Except for changing the pressure of the pressurized fluid and using a slit chamber, the sterilization treatment was carried out in the same manner as in the confirmation test of the sterilization effect of Example 1 to confirm the presence or absence of the sterilization effect on hiochi bacteria. The results are shown in the table below. The temperature of the liquid material to be treated in the sterilization treatment using the wet-type atomization device was 55° C. or lower.

[0079] [Table 3]

[0080] It was confirmed that when the injection pressure was 100 MPa or more, the hiochi bacteria could be sterilized with one pass.

[0081] [Example 3] Except for changing the pressure of the pressurized fluid and using a slit chamber, the sterilization treatment was carried out in the same manner as in the confirmation test of the sterilization effect of Example 1 to confirm the presence or absence of the sterilization effect on yeast. The results are shown in the table below. The temperature of the liquid material to be treated in the sterilization treatment using the wet-type atomization device was 55° C. or lower.

[0082] [Table 4]

[0083] It was confirmed that when the injection pressure was 100 MPa or more, the yeast could be sterilized with one pass.

[0084] [Example 4] The sterilization treatment was carried out in the same manner as in the confirmation test of the sterilization effect in Example 1 to confirm the sterilization effect, and various measurements related to sake were carried out on the treated products sterilized with the number of passes shown in the table below (spray pressure: 200 MPa). The results are shown in the table below. The temperature of the liquid material to be treated in the sterilization treatment using the wet-type atomization device was 55° C. or lower. General analysis and analysis of aroma components were performed according to the standard analysis method annotations of the National Research Institute of Brewing. Analysis of glucose and organic acids was performed using liquid chromatography.

[0085] [Table 5]

[0086] From Table 5, it can be seen that there was almost no change in sake meter value, acidity, amino acid content, alcohol concentration, or glucose concentration, and that there was no adverse effect on sake quality. Organic acids and aroma components decreased slightly in the high-pressure treated sake, but the decrease was only about 10%, so it was found that this did not have a significant effect on sake quality. This makes it clear that the treatment according to the present invention does not cause significant deterioration in the quality of sake. [Explanation of symbols]

[0087] 12 Nozzles 14 Hard Ball 16,26 Exit 22,23 Nozzle 30 Slit Chamber 32 Chamber flow path 33 Chamber body 34 Upstream nozzle 35 Downstream nozzle 37 Load-receiving nozzle 38 Nozzle 80 Raw Material Tank 82 Supply pump 84 Booster 86 Ultra High Pressure Filter 88 Heat exchanger 89 Valve

Claims

1. A sterilization treatment method in which pressure is applied to a liquid to be treated containing brewed liquor to obtain a pressurized fluid, and an impact force is applied to the pressurized fluid to perform a sterilization treatment on the liquid to be treated.

2. The sterilization treatment method according to claim 1, wherein the impact force is generated by causing the pressurized fluid to collide with a hard material or by causing the pressurized fluids ejected from at least a pair of nozzles to collide with each other.

3. The sterilization treatment method according to claim 1, wherein the impact force is applied within a slit chamber.

4. The sterilization treatment method according to claim 1, which is performed in a closed circuit so as to be circulable.

5. The sterilization treatment method according to claim 1, wherein the pressure is 100 to 300 MPa.

6. The sterilization treatment method according to claim 4, wherein the number of times of circulation is 2 or more.

7. The sterilization treatment method according to claim 4 or 5, which is performed at a temperature lower than 60°C.

8. A brewing step of fermenting a raw material for brewed liquor to obtain brewed liquor, A method for producing brewed liquor, comprising: a sterilization step of applying pressure to a liquid to be treated containing the brewed liquor to obtain a pressurized fluid, and applying an impact force to the pressurized fluid to perform a sterilization treatment on the liquid to be treated.

9. The method for producing brewed liquor according to claim 8, which is performed at a temperature lower than 60°C.

10. Brewing means for fermenting a raw material for brewed liquor to obtain brewed liquor, A brewed liquor production system, comprising: sterilization means for applying pressure to a liquid to be treated containing the brewed liquor to obtain a pressurized fluid, and applying an impact force to the pressurized fluid to perform a sterilization treatment on the liquid to be treated.

11. The brewed liquor production system according to claim 10, wherein the sterilization means includes a chamber for applying an impact force to the pressurized fluid, and an injection nozzle for injecting the pressurized fluid into the chamber.

12. The brewed liquor production system according to claim 11, wherein at least the contact surface of the injection nozzle with the pressurized fluid is made of a diamond-based material.

Images