JPH0159865B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinegar brewing method and apparatus that can produce high quality vinegar in a short period of time and with good yield. Various methods are conventionally known for brewing vinegar, one of which is a static fermentation method. This method has the advantage of producing brewed vinegar of superior quality compared to other methods such as the submerged aeration stirring fermentation method, but it requires a long period of time for fermentation and is difficult to carry out on a large flat surface. Because of this, the yield of acetic acid per unit area is low, and since the fermentation is carried out in an open system, there is a large amount of evaporation and loss of alcohol, acetic acid, etc. in the moromi, making it impossible to obtain acetic acid, that is, vinegar, in a good yield. have. Therefore, the inventors of the present invention have conducted intensive studies to eliminate the above disadvantages while retaining the advantages of the static fermentation method for vinegar brewing. As a result, we have found that a number of disks with a large surface area are skewered into a closed fermentation tank. A rotary shaft supported in a shape is horizontally suspended, the lower end of the disc is immersed in the raw material mash of vinegar, acetic acid bacteria are grown on the disc, and the disc is rotated at a low speed to form a disc in the raw material mash layer. The raw material moromi is adhered and held in the buried part of the disc, and then in the gas phase part, the raw material mortar adhered and held on the disc is supplied by gravity onto the acetic acid bacteria that have grown on the disc, and the oxygen in the gas phase is Concentration 5-60% (V/V)
(Hereinafter, the oxygen concentration is expressed as V/V.) By carrying out acetic acid fermentation while maintaining the oxygen concentration at , based on this knowledge, completed the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in more detail below by showing one example of the apparatus of the present invention with reference to the accompanying drawings, and further showing a method for producing vinegar using the apparatus. In FIG. 1, reference numeral 1 denotes a closed fermentation tank, which is composed of a box-shaped tank body 1a in which raw material mash is stored and a semicylindrical lid 1b that seals the tank body. Reference numeral 2 denotes a bearing provided on the periphery of the fermentation tank, a rotating shaft 3 is constructed on this bearing, a plurality of plates 4 are supported in a skewed manner on the rotating shaft, and the rotating shaft is driven by a motor or the like (not shown). Constructed so that it can be rotated. Then, a part of the plate 4, in this case the lower end thereof, is installed in the vinegar raw material layer. Reference numeral 8 denotes an air supply pipe, one end of which communicates with the gas phase section 5 of the fermentation tank, and the other end of which communicates with an oxygen supply source 7 such as an air supply pump or an oxygen cylinder via an on-off valve 6 such as a solenoid valve. Reference numeral 9 denotes a pressure regulator, which allows part of the gas in the gas phase to be exhausted through the pressure regulator 9 when the gas pressure in the gas phase becomes higher than a certain value (for example, normal pressure). Usually, a check valve or, as shown in the figure, a long and narrow communication pipe inserted into the top wall of the fermentation tank 1 is used. Further, a jacket through which cold water flows may be provided along the outer circumferential wall of the main body of the pressure regulating device to cool the device. In this way, useful components such as ethyl alcohol vapor (hereinafter simply referred to as alcohol) and acetic acid vapor contained in the gas phase are condensed and reduced to the raw mash, improving the yield of vinegar. Reference numeral 10 denotes an oxygen concentration detection element provided in the gas phase portion of the fermentation tank. The device 11 is configured so that the oxygen concentration in the gas phase is always within a specific range. That is, the oxygen concentration in the gas phase measured by the oxygen concentration detection element 10 is determined by the oxygen concentration control device 11.
This output is used to open and close the on-off valve 6, thereby automatically adjusting the oxygen concentration in the gas phase section 5. Reference numeral 13 denotes a circulation pipe for circulating and cooling the gas phase, which communicates at least two arbitrary locations in the gas phase 5 of the fermentation tank (in this example, two locations at the top wall end of the lid 1b of the fermentation tank). However, a gas circulation device 12 and a temperature control device 22 are provided in the middle. Reference numeral 18 denotes a temperature measuring device such as a thermometer, which may be integrated with the temperature measuring device, or the temperature of the temperature adjusting device 22 can be adjusted via a temperature control device 17 provided separately as shown in FIG. Control unit 20 such as a cold water flow opening/closing valve
By controlling the temperature of the gas phase, the temperature of the moromi is always kept at a specific temperature. Reference numeral 14 denotes a temperature measuring body such as a thermometer inserted into the raw material mash, which is connected via the temperature control device 16 to the control unit 21 of the temperature control device 15 provided in the raw material mash layer.
(in this example, the hot/cold water flow on/off valve),
It is configured so that the temperature of the moromi is always at a specific temperature. The above two temperature control devices 15 and 22 may be used when temperature control of the gas phase portion or the raw material moromi is required. A huge amount of fermentation heat is generated on the surfaces of the many plates 4 during acetic acid fermentation, but since the plates have a large surface area, the fermentation heat is effectively released into the gas phase. The fermentation heat is conducted through the outer wall of the fermentation tank and released into the atmosphere. Therefore, the outer peripheral wall of the fermentation tank should be made of a metal with good thermal conductivity and strong corrosion resistance, such as stainless steel, or a jacket or the like should be installed along the outer peripheral wall of the fermentation tank to allow hot and cold water to flow through it. In this case, the temperature control device described above becomes unnecessary. Examples of the plate supported on the rotating shaft in the form of a skewer include rectangular plates, polygonal plates, disks, helical disks, and plates with large surface areas such as blades. In particular, disks and helical disks are preferred in order to uniformly supply the material to the raw plate. It is important that the surface of the plate is made of a material that allows acetic acid bacteria to easily adhere to it. Such materials include cloth and water-insoluble paper, with thick cloth and lipophilic (hydrophobic) nonwoven fabric being particularly preferred. Specific examples of thick nonwoven fabrics include WOSEP (manufactured by Toyo Rayon Co., Ltd.), Toughnel Oil (manufactured by Mitsui Petrochemicals), and TEIJIN-OLSORB (manufactured by Teijin Co., Ltd.). Examples include cotton flannel etc. The method of growing acetic acid bacteria on a plate is to immerse the plate in the raw material moromi inoculated with acetic acid bacteria for 10 to 20 seconds, and then withdraw it into the gas phase for several seconds to several minutes. You can repeat this for several days at an appropriate temperature. The simplest method is to immerse the lower end of a plate such as a disc or a spiral disc in raw material mortar inoculated with acetic acid bacteria.
With the upper part in the gas phase, heat the plate for 1 to 4 r.
If the plate is rotated at a slow rotational speed of pm for 1 to 5 days at a temperature suitable for the growth of acetic acid bacteria, acetic acid bacteria will fully attach to the parts of the plate that are not submerged in the raw material mash. The acetic acid bacteria that have grown on the plate can be used repeatedly. In the case of batch fermentation, the lag phase is hardly observed from the second fermentation, and even if the plate rotation stops due to equipment failure, the acetic acid involved in acetic acid fermentation is Since the bacteria grow on the parts of the plate that are exposed to the gas phase and are not submerged in the raw material mortar, they do not die due to oxygen starvation. The acetylation rate of a plate with acetic acid bacteria, that is, the rate of oxidation of ethyl alcohol to acetic acid, is not much different from the acetylation rate of a bacterial film in the conventional static fermentation method when calculated per unit area. By arranging a large number of plates at appropriate intervals in the tank, the bacterial membrane area can be significantly increased and the fermentation period can be significantly shortened compared to the static fermentation method. As mentioned above, the method of bringing the raw moromi into contact with a part of the plate is to immerse the lower end of the plate in the raw material moromi for a short time, for example, 20 seconds, and the other method is to bring the raw mash into contact with a part of the plate. Examples include spraying methods. In this way, the raw material moromi adhering to the lower end or a part of the plate will move toward the center of the plate as it rotates in the gas phase, and if the moromi is sprayed at the center of the plate, it will spread to the surrounding area. The acetic acid bacteria flow down by gravity, are supplied to the acetic acid bacteria growing there, and come into sufficient contact with the acetic acid bacteria to undergo acetic acid fermentation. The raw material mash used in the present invention may be of any type as long as it is prepared according to the usual vinegar brewing method, such as alcoholic beverages such as Japanese sake and grape wine, as well as potatoes and grains. Examples include alcohol-containing brews obtained by saccharification and alcoholic fermentation, or alcohol-containing aqueous solutions to which nutrients for acetic acid bacteria are added. Since fermentation is carried out in a closed system, it is possible to prevent as much as possible the evaporation loss of acids such as alcohol, acetic acid, and water, which are components of the raw moromi, during acetic acid fermentation, thereby improving the yield of acetic acid from alcohol, that is, the yield of vinegar. rate increases significantly. However, since it is carried out in a closed system, the oxygen concentration in the gas phase of the fermentation tank is measured, and when the oxygen concentration drops, oxygen is supplied to maintain the oxygen concentration at 5 to 60%. This is extremely important; if the oxygen concentration is too high or too low, the acetylation rate will be slow and the flavor will deteriorate. Examples of oxygen used here include air, a highly concentrated oxygen-containing gas with an oxygen concentration of 21% or more, and pure oxygen. When using air or a high-concentration oxygen-containing gas as oxygen, gases other than oxygen (e.g. nitrogen gas) remain in the gas phase without being used as the fermentation occurs, so the oxygen concentration in the gas phase is supplied. In order to maintain a single point concentration close to that of the oxygen-containing gas produced in the fermentation tank, this nitrogen gas must be discharged from the fermentation tank using a pressure regulator. Since it is almost impossible to discharge oxygen from the pressure regulator to the outside of the tank, in order to maintain the oxygen concentration in the gas phase at a constant concentration for a long time, the amount of air supplied must increase, and a huge amount of oxygen is discharged from the pressure regulator. As a result, there is a risk that useful components of the moromi will escape. Therefore, in this case, the oxygen concentration should be set at two points, the upper limit and the lower limit, within the above range, and when the oxygen concentration reaches the lower limit, air is supplied to increase the oxygen concentration to the upper limit in a short time. , only a small amount of air is needed,
As a result, the amount of exhaust gas is also reduced, thereby preventing useful components such as alcohol from escaping. In other words, when air is used as oxygen, the oxygen concentration in the gas phase is set at an arbitrary upper and lower limit within the range of 5 to 19%, and when the oxygen concentration reaches the lower limit, air is supplied to remove the oxygen. The concentration is increased to the upper limit value in a short period of time, air supply is stopped, and this operation is repeated intermittently thereafter. In particular, when the upper limit is in the range of 13 to 17% and the lower limit is less than that, the amount of air supplied may be even smaller, and therefore, the escape of alcohol, etc. is almost eliminated. However, if the upper limit is set to 18% or 19% and the lower limit is less than 18% or 19%, if the gap between the upper and lower limits is less than 2%, it will be necessary to constantly supply air. increases, and the yield of vinegar decreases. Therefore, it is preferable to set the lower limit value with an interval such that the upper limit value and the lower limit value are 2% or more, preferably 3% or more. Next, when using a high-concentration oxygen-containing gas of 21% or more as oxygen, set arbitrary upper and lower limits for the oxygen concentration in the gas phase in the fermentation tank within the range of 5 to 60%. When the concentration reaches the lower limit, a high concentration oxygen-containing gas is supplied to increase the oxygen concentration in a short time. At this time, the higher the oxygen concentration or purity is, the smaller the amount of air to be fed is required, and the amount of exhaust gas is also reduced, making it possible to prevent useful components from escaping with the exhaust gas. In addition, when using pure oxygen as oxygen, all of it is used for acetic acid fermentation, so there is almost no exhaust gas discharged outside the fermentation tank via the pressure regulator, and the escape of alcohol etc. can be prevented, so the vinegar The yield is significantly improved. Next, the fermented mash obtained as above is
The entire amount is discharged from the fermentation tank, and then the vinegar is aged, filtered, and adjusted to specifications according to the usual vinegar brewing method, and then sterilized to produce a product. As is clear from the above explanation, the present invention involves vertically arranging a large number of plates with a large surface area at appropriate intervals in a closed fermentation tank, and bringing a portion of each plate into contact with the vinegar raw material. Since it is a rotating device, the bacterial membrane area can be significantly increased compared to conventional static fermentation methods, and the fermentation period can be significantly shortened. Furthermore, unlike conventional submerged aeration and stirring fermentation methods, the present invention does not vigorously aerate and stir the vinegar raw material moromi, but rather performs acetic acid fermentation without moving the vinegar raw material. Because of this, the quality of the vinegar is superior in flavor to that obtained using the liquid stirring fermentation method, and is of a high quality that is comparable to that obtained using the conventional static fermentation method. of vinegar is obtained. Furthermore, since the fermentation is carried out in a closed system, the evaporation and dissipation of alcohol, acid, water, etc., which are useful components in the raw moromi, can be prevented as much as possible during the acetic acid fermentation, and vinegar can be obtained with a high yield. Can be done. The present invention will be explained in more detail below with reference to Examples. Example 1 The fermentation tank 1 is composed of a box-shaped tank body 1a (length 37 cm, width 20 cm, depth 30 cm) with a preparation capacity of 20 cm and a semi-cylindrical lid body 1b that seals this, and the plate body 4 is chlorinated. 15 discs with a diameter of 18 cm were obtained by coating both sides of vinyl discs with a thick cloth "Toughnel Oil" (manufactured by Mitsui Petrochemicals) [Plate area: 226 cm ² × 30 = 6782
cm ² ], supported on the rotating shaft 3 in a skewer shape at intervals of 15 mm, and the rotation speed of the rotating shaft was 2 r.pm,
The oxygen concentration detection element 10 is an RA oxygen meter manufactured by Oriental Electric Co., Ltd. for both air and liquid use, and the oxygen concentration control device 11 is a Yamatake Honeywell controller.
0-100% system, the temperature control device 22 was a Dimroth type cooling pipe, and the gas circulation device 12 was a small air pump as shown in FIG. In the fermentation tank shown in Figure 1, put sake (alcohol 13
%) 6.15, seed vinegar (acidity 6.1%) 3.28 and alcohol (purity 99%). The raw material moromi mixed with acetic acid bacteria, obtained by adjusting the volume of 100 g with water to 20, is charged so that the lower end of the plate is submerged by 2 cm, and is detected by the oxygen concentration detection element 10 and the oxygen concentration control device 11. The control valve 6 of the air supply pipe 8 is automatically opened and closed to start supplying air when the oxygen concentration in the gas phase reaches the lower limit of 12%, and when it reaches the upper limit of 15%. was stopped and the oxygen concentration was maintained in the range of 12-15%.
The rotational speed of the rotating shaft 3 is maintained at 2 rpm, and when the temperature of the mash exceeds 30°C, the gas phase is continuously extracted and the heat is removed through the heat exchange section in the temperature control device 22.
Furthermore, the mixture was returned to the fermentation tank via the gas circulation device 12, and fermentation was carried out while controlling the surface layer of the moromi at 29 to 31° C., and changes in acidity over time were examined. Next, all of the moromi that has undergone acetic acid fermentation is pumped out from the fermentation tank, and the plates on which acetic acid bacteria have grown remain as they are, and the same amount of new raw material moromi with the same composition as above is charged again, and acetic acid fermentation is carried out in the same manner. The changes in acidity over time were investigated. Figure 2 shows a summary of the changes in acidity over time in the two acetic acid fermentation methods, including the first time and the transfer. From this result, the lag of about 2 days for the first time.
Faisu is recognized but handed over (2nd time)
This was not observed in the case of , and it can be seen that the acetylation rate was also somewhat fast. Example 2 In acetic acid fermentation carried over from Example 1,
Using ``WOSEP'' (manufactured by Toyo Rayon Co., Ltd.) instead of the thick cloth ``Toughnel Oil'',
The process was carried out in exactly the same manner as the acetic acid fermentation carried over from Example 1, except that the rotational speed of the rotating shaft was changed to 1/2, 1, 2, and 4 rpm. For comparison, the plates on which acetic acid bacteria had grown in the fermentation tank shown in Figure 1 were removed to create a closed fermentation tank, and the same amount of raw mash having the same composition as in the example was charged and static fermentation was performed. . Furthermore, for comparison, in the fermentation tank shown in Figure 1, the plates on which acetic acid bacteria have grown and the lid that seals the fermentation tank are removed to create an open fermentation tank and alcohol (99% purity) is added to it. The same amount of raw mash as in Example 1 was prepared, except that the amount was changed to 200 g, and static fermentation was performed. As a result, no loss of moromi was observed in the closed fermentation tank, but in the open system.
A decrease of 0.5 was observed. When the changes in acidity over time in each method were investigated, the results shown in FIG. 3 were obtained. Furthermore, in each method, the period required to complete the fermentation and the yield of acetic acid from alcohol were investigated, and the results shown in Table 1 were obtained.

[Table] From the results in Table 1 and Figure 3, the open standing method of Comparative Example 2 required a long period of 20 days to complete fermentation, and the evaporation of alcohol etc. during the acetic acid fermentation was large. Therefore, it can be seen that the acidity of the mortar juice at the end of fermentation is low, and the yield of acetic acid from alcohol is extremely low at 60% of the theoretical value. On the other hand, in the category of the present invention, the period required to complete fermentation is 6 to 13 days, which is extremely short at about 1/2 to 1/4 compared to the 24 days of the closed standing method of Comparative Example 1.
It was found that by further increasing the number of plates, the period required to complete the fermentation could be further shortened, and it was also found that the yield of acetic acid was extremely high at 94%. Next, the vinegar obtained in the three categories of the present invention shown in Table 1,
Vinegar obtained in Comparative Example 2 category [both acidity
4.5% (W/V)] was conducted by a trained panel of 20 people, and the results shown in Table 2 were obtained.

[Table] From the results in Table 2, the vinegar obtained by the present invention has a lower aroma and aroma than that obtained by the comparative example.
There was no statistically significant difference between the two in terms of taste and overall quality, and it can be seen that the present invention yields high-quality vinegar that is completely comparable to vinegar obtained by the static fermentation method.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing one specific example of the apparatus of the present invention, and FIGS. 2 and 3 are diagrams each showing changes in acidity over time. DESCRIPTION OF SYMBOLS 1... Fermentation tank, 3... Rotating shaft, 4... Plate, 5... Gas phase section, 8... Air supply pipe, 9... Pressure regulator, 10... Oxygen concentration detection element, 11... Oxygen Concentration control device.

Claims (1)

[Scope of Claims] 1. In a closed fermentation tank, a plate on which acetic acid bacteria have been preliminarily grown is vertically rotated, and parts of the plate are successively brought into contact with the raw material mash of vinegar, and the fermentation tank is A method for brewing vinegar characterized by carrying out acetic acid fermentation while maintaining the oxygen concentration in the gas phase at 5 to 60% (V/V). 2. Adjust the oxygen concentration in the gas phase in the fermentation tank to 5-19%.
(V/V) A patent that holds an arbitrary upper and lower limit value set within the range, and when the oxygen concentration reaches the lower limit value, air is supplied to quickly raise the oxygen concentration to the upper limit value repeatedly. A method for brewing vinegar according to claim 1. 3. Reduce the oxygen concentration in the gas phase in the fermentation tank to 5-60%.
(V/V) When the oxygen concentration reaches the lower limit value, the oxygen concentration 21
% (V/V) or more of a highly concentrated oxygen-containing gas to rapidly raise the oxygen concentration to the upper limit value. 4. The vinegar brewing method according to claim 1, in which acetic acid fermentation is carried out while supplying pure oxygen to maintain the oxygen concentration in the gas phase in the fermentation tank at 5 to 60% (V/V). . 5 A closed fermentation tank 1, a bearing 2 provided at the periphery of the tank, and a rotating shaft 3 horizontally suspended on the bearing.
, a plate body 4 supported in a skewer shape on a rotating shaft, an air supply pipe 8 whose one end communicates with the gas phase section 5 in the tank and the other end communicates with an oxygen supply source 7 via an on-off valve 6; A pressure regulating device 9 provided through the outer peripheral wall of the phase part,
an oxygen concentration detection element 10 provided in the gas phase section;
A vinegar brewing apparatus comprising the detection element 10 and an oxygen concentration control device 11 that connects the on-off valve 6 of the air supply pipe 8. 6. The device according to claim 5, wherein the plate body is covered with one selected from cloth and lipophilic nonwoven fabric. 7. The device according to claim 5 or 6, wherein the plate is one selected from a disk and a helical disk.