JPS58116673A - Preparation of edible vinegar and apparatus therefor - Google Patents

Abstract

PURPOSE:To obtain an edible vinegar sanitarily in high yield in a short time in preparing the edible vinegar in a closed fermentation tank by the stationary fermentation method, by adjusting the oxygen concentration in the fermentation tank to keep the concentration always within a given range. CONSTITUTION:A raw material unrefined SAKE 2 is introduced into a closed fermentation tank 1 and inoculated with acetic acid bacteria to prepare an edible vinegar by the stationary fermentation method. In the process, at least two positions of the vapor phase part 3 formed in the top of the tank 1 are communicated with a recirculating pipe 4 having a temperature controlling apparatus 5 and a gas circulating apparatus 6, and an oxygen concentration sensor element 11 is inserted in the vapor phase circulating path 4 to measure the oxygen concentration in the vapor phase part 3. If the oxygen concentration is reduced below the specified value during the fermentation, an air supplying apparatus 10 is automatically operated to keep the oxygen concentration in the vapor phase part 3 at 5-19 (V/V)%. The temperature of the vapor phase part 3 is controlled by the temperature controlling apparatus 5 to keep the surface layer of the unrefined SAKE 2 within about 30+ or -2 deg.C range.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for producing vinegar by a static fermentation method or a fermentation method similar thereto. By supplying air to the upper space inside the tank (hereinafter referred to as the gas phase) and maintaining the gas phase at a predetermined oxygen concentration, and statically culturing, vinegar can be produced in a relatively short period of time, with good yield, and in a sanitary manner. Various methods have been known for producing table vinegar, including
One of these methods is the static fermentation method.

This method yields brewed vinegar of superior quality compared to other methods, and has the advantage of being extremely easy to manufacture using equipment. However, the disadvantage of this method is that it takes a long time to manufacture. During the manufacturing process, the raw material ingredients alcohol, acid (acetic acid), and water evaporate and are lost, resulting in poor yield of the vinegar product, or raw material utilization rate. When it is full of water, the working environment deteriorates significantly, and when it is released outside, it causes pollution problems such as corrosion of metals in nearby buildings, and furthermore, the moromi is easily contaminated by bacteria, insects, and other organisms during the manufacturing process. This means that there are some disadvantages. In order to prevent this contamination and the moromi from spoiling, there is a method in which the initial acidity of the moromi is set to λ and the final acidity is 4LS or more, or a method in which the initial acidity is set to 3 and the final acidity is 3% or more. Measures have been taken to increase the initial acidity of the moromi (vinegar concentration at the time of preparation), but this results in almost half of the produced vinegar being sent back to the preparation, and the acidity of the moromi is also high. As the rate of acetic acid production by acetic acid bacteria becomes slower, the amount of vinegar produced relative to the capacity of the fermentation tank has the disadvantage of being extremely small.

Therefore, in order to eliminate the above-mentioned drawbacks of the vinegar manufacturing method using the static method, the present inventors carefully overlapped the sides, and as a result, they charged the raw material acid to a closed fermentation tank and inoculated acetic acid bacteria, and added it to the gas phase in the tank. By statically culturing while supplying air and maintaining a constant oxygen concentration in the gas phase, it is possible to produce vinegar of excellent quality in a relatively short period of time, at a high yield, and with almost no influence from bacteria. They discovered that it is possible to manufacture the product in a good working environment without any problems, and based on this discovery, they completed the present invention.

- That is, the present invention measures the oxygen concentration in the gas phase in a closed fermentation tank, and when the oxygen concentration decreases, air is supplied to adjust the oxygen concentration in the gas phase from evening to evening.
(V/V) %, and the present invention is a method for producing table vinegar by a static fermentation method, which is characterized in that the vinegar is maintained at Measure the oxygen concentration, and when the oxygen concentration decreases, air is supplied to increase the gas phase oxygen concentration to /9 (V/V)%.
This is a method for producing vinegar by a static fermentation method, which is characterized in that the vinegar is maintained in such a manner that the vinegar is removed from the gas phase, the temperature is adjusted, and the vinegar is returned to the gas phase again. a closed fermentation tank; a return piping comprising a temperature control device and a gas circulation device that connects at least two points in the gas phase within the fermentation tank; the fermentation tank; and the return pipe; This is an apparatus for producing vinegar by a static fermentation method, which includes an air supply vibrator which opens into a gas phase circulation path consisting of <Eve≠, and a pressure regulating valve/3 provided in the circulation path.

The present invention will be explained in detail below.

In the present invention, the fermentation tank is a closed system, the oxygen concentration in the gas phase of the tank is measured, and when the oxygen concentration decreases, air is supplied to adjust the oxygen concentration in the gas phase to j~/q (v/V).
%.

This is extremely important; if the oxygen concentration is less than 1, the rate of acetic acid production will be extremely slow and the aroma will be bad.

On the other hand, if it exceeds 79 degrees, it becomes necessary to supply air almost continuously to maintain the concentration, and the amount of air supplied increases rapidly, resulting in the loss of components such as alcohol. suddenly becomes larger.

When the oxygen concentration in the gas phase is maintained at 9% (V/V), acetic acid is efficiently produced, reaching the theoretical yield! Good quality vinegar can be obtained with a yield of J% or higher, but especially at /3
When maintained at ~/♂% (V/V), high quality vinegar can be obtained in a short period of time with a high yield.

Then, as described in Examples below, the oxygen concentration is set at two points, an upper limit value and a lower limit value, within the above range, and when the oxygen concentration reaches the lower limit value, air is supplied to increase it all at once to the upper limit value. If the upper limit is set to one of 73 to /7q6 and the lower limit is set to less than that, the amount of air supplied may be small, and therefore there is almost no loss of alcohol, etc. However, the upper limit /? If the lower limit value is lower than 79%, the difference between the upper limit value and the lower limit value is 2% or more,
It is preferable to set the lower limit value at a constant interval, preferably 3% or more. In that case, if the interval is less than 296, it will be necessary to constantly supply air, which will increase the loss of alcohol, etc., and reduce the yield of vinegar.

Furthermore, in acetic acid fermentation, a huge amount of fermentation heat is generated in the liquid phase of the moromi during fermentation, so efficient removal of this fermentation heat is extremely important. Conventionally, a method is known in which the temperature of the moromi is adjusted by flowing cold water or hot water down the outside of the fermentation tank to cool or heat the outer peripheral wall of the fermentation tank, but this method does not provide effective temperature control. This is undesirable because it is difficult to clean the room, and sewage water scatters indoors, creating a humid environment. Fermentation tanks with a so-called internal heat exchange method are also known, in which a corrugated pipe heat exchanger is incorporated into the liquid phase within the fermentation tank, but this method is not effective in cooling the area near the liquid level and the structure of the tank deteriorates. It is complicated, difficult to repair and clean in the event of a breakdown, and has the disadvantage that the equipment cost is extremely high.

The above two methods involve heating or cooling the entire liquid layer (moromi), but heating the entire moromi will cause a warm odor to stick to the product and will also heat the acid. Therefore, the color becomes rich and the quality of the product deteriorates, which is not preferable.

As a result of various studies, the present inventors found that in acetic acid fermentation,
During fermentation, fermentation heat is not generated throughout the entire moromi, but only in the surface layer of the moromi.On the other hand, if the temperature of the moromi is low and it is heated to the optimum temperature for the growth of acetic acid bacteria, We discovered that it was only necessary to heat the surface layer of the moromi instead of heating the entire fermentation tank, and after further investigation, we extracted the gas phase from the fermentation tank to the outside of the tank and sent it to a heat exchanger to remove the heat. If the moromi is heated and then circulated back into the original tank, it is possible to effectively remove or heat only the surface layer of the moromi, resulting in a total loss of product quality. It was discovered that the fermentation of moromi can be completed in an extremely short period of time without causing any problems.

Hereinafter, the present invention will be explained in further detail by showing seven examples 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 the attached drawing, / is a closed type fermentation tank, and C is the raw acid (liquid phase) sealed in this tank. A gas phase part 3 is formed in the upper part of this tank. At least λ points (in this example, two points on the top wall of the fermentation tank) are controlled by a temperature control device! and a built-in vibrator equipped with a gas circulation device B, the fermentation tank and the built-in vibrator form a gas phase circulation path, and the end of the air supply pipe is communicated with the fermentation tank. The other end is connected to an air supply device such as an air supply pump IO. Further, an oxygen concentration detection element // is inserted into the gas phase circulation path to measure the oxygen concentration in the circulation path, and the oxygen concentration detection element // receives the measured value signal by an attached oxygen meter 7. A contact signal is obtained by the oxygen partial pressure control device/2, and this signal operates the air supply device IO, so that the oxygen concentration in the circulation path decreases to a predetermined value or When it rose,
The air supply device /θ is automatically operated via the oxygen partial pressure control device /2, so that the oxygen concentration in the gas phase is maintained within a certain range.

Also, /3 is a pressure regulating valve, so that when the gas pressure in the gas phase becomes higher than a certain value (for example, normal pressure), a part of the gas in the gas phase can be exhausted through the pressure regulating valve /3. The pressure regulating valve may be simply a long and narrow communication pipe inserted into the top wall of the fermentation tank as shown in the figure. Further, if necessary, a gas guide plate/plate may be provided opposite the gas discharge port of the embedded pipe so as not to damage the acetic acid bacteria membrane in the fermentation tank.

In the present invention, the air supplied to the gas phase may be natural air.

In addition, /≠ is a temperature measuring device such as a thermometer, which communicates with the temperature control device j installed in the middle of the embedded pipe≠ via the temperature control device /j, so that the temperature of the moromi is always at a specific temperature. It is composed of Also, /B is a circulation pump, /7 is a heating or cooling water holding tank, and / is a filter.

As is clear from the above explanation, the present invention measures the oxygen concentration in the gas phase in a closed fermentation tank, and when the oxygen concentration decreases, air is supplied to provide oxygen in the gas phase. Since the concentration is maintained at 5 to 9% (V/V), acetic acid fermentation is completed in a relatively short period of time, and the raw materials such as alcohol, acetic acid, and water are evaporated during the production process. Since losses can be significantly prevented, it is possible to produce a large amount of vinegar at a high yield relative to the size of the equipment, and there is almost no influence from bacteria or harmful organisms during the production process. It has the advantage of being able to produce vinegar hygienically and without significantly deteriorating the working environment.

In addition, the oxygen concentration in the gas phase of the fermentation tank was set to j~/9 (V/
In addition to the above-mentioned advantages, the following advantages are obtained when holding the sample at a temperature of V )%, extracting the gas from the vapor phase, adjusting the temperature, and then embedding it in the vapor phase again.

In other words, the huge amount of fermentation heat generated in the surface layer of the moromi during fermentation can be removed extremely efficiently, and only the surface layer of the moromi can be heated extremely efficiently, so heat is applied to the outer peripheral wall of the fermentation tank.・
There is no need to install a device for flowing cold water, to enclose a jacket that allows the flow of hot and cold water, or to incorporate a coiled pipe heat exchanger inside the fermentation tank, so the structure of the fermentation tank can be greatly simplified. It can be simplified.

In addition, since the method heats or cools only the surface layer of the moromi, rather than heating or cooling the entire moromi, the vinegar may have a warm brewed odor, or the vinegar may Coloring and staining defects are prevented, and vinegar of very high quality can be obtained. Furthermore, the condensate produced when the gas phase is heat removed can be buried in the mash in the fermentation tank, significantly increasing the yield.

Hereinafter, the present invention will be explained in more detail by showing examples.

In addition, in the present examples and comparative examples, acidity refers to
Accurately measure mA' in a large test tube, add a drop of /% phenolphthalene (alcoholic solution), and then
! r Titrate with N caustic soda to the point of discoloration, and the titration m
It is expressed as acidity @) by 0.3 times e.

Example The closed fermentation tank and attached equipment used in this example are shown in the figure/
It shows. Oxygen concentration detection element // is manufactured by Oriental Electric (
The oxygen partial pressure controller/2 is a RA type oxygen meter for both air and liquid use manufactured by the company, and the oxygen partial pressure controller/2 is a
~100 system", the temperature control device is a heat exchange device equipped with a heat exchange coil/9 that allows hot or cold water to flow inside [2. The gas circulation device is a small blower, and air is supplied The apparatus was set as shown in FIG. 1, using the device /θ as an air pump.

The composition of the moromi used for preparation is shown in Table 7 below.

The moromi shown in Table 1 was placed in the fermentation tank shown in the figure, and the surface layer of the moromi was maintained within the range of 3θ°C±2'C using a temperature side leg device.

When the oxygen concentration in the gas phase reached the lower limit in Table 2, the supply of air was started, and when the upper limit was reached, the supply was stopped to maintain the oxygen concentration within a predetermined range. There was no detectable change in the volume of moromi between the beginning and the end of brewing. Yield is expressed as a ratio of the theoretical value of acetic acid produced from alcohol. The final acidity was expressed as the value when the residual alcohol concentration in the acid became 0.2 coefficient or less. The number of days required from the loading point is indicated by the number of days until the final acidity is reached. The liquid depth 3θcm corresponds to the case where 9 t of moromi is prepared, and the liquid depth jOcm corresponds to the case where the mash/jt is prepared. The results are shown in Table 2.

Furthermore, as a comparative example, diameter/9. ! ; cm, height 1
．． Add sake IA (IS"t (alcohol/2j%), seed vinegar (acidity 1..2%)) 2.l/Lt1 water 711# = Ranal JJXIMiH to a normal open fermentation tank with 0cm1 charging volume/jt. Add alcohol /JOf/ (alcohol concentration: O, acidity: A/%) into the fermentation tank, then cover with a lid having two holes with a diameter of about 10 mm, and leave it at an outside temperature of 27 to 32 °C. Fermentation was carried out.The number of days required from preparation to completion of fermentation was 2 days, the acidity of the moromi liquid at the end of fermentation was 2%, and the surface layer of the moromi (3 crn below the liquid level)
) The product temperature was 27-3°C, the yield of vinegar was /≠t, and the yield was about Otsu θ.

Table 1. Moromi composition sake used in the examples: Alcohol /, 2. ,,! -chi lA and t
Seed vinegar: acidity A, 2q6 2.11 tt water (distilled water) 7 and t acetic acid bacteria: Institute of Microbial Technology, Agency of Industrial Science and Technology In this method, although the initial alcohol concentration is high, the acidity of the mortar at the end of fermentation is as low as 2%, so high concentration vinegar cannot be obtained, and the yield of acetic acid is low. It can be seen that the theoretical value of θ is very low, and that the temperature of the acid increases to an abnormally high 3°C with fermentation. In contrast, in the method of the present invention, although the initial alcohol concentration is low, high-concentration vinegar with an acidity J of 2% is obtained at the end of fermentation, and the acid temperature is
The temperature can be controlled within an extremely favorable range of 2♂~32°C, and the yield of acetic acid can be kept within the theoretical value! It can be seen that it can be significantly increased by more than j%.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing a specific example of the vinegar manufacturing apparatus of the present invention. /...Fermentation tank, Co...Raw acid, 3...Gas phase, ≠...Embedded pipe,! ...Temperature control device, g...
・Gas circulation device, 7...Oxygen meter, elementary partial pressure control device, /
3...Pressure regulating valve, /4'...Temperature measuring element. Patent applicant Kikkoman Corporation

Claims (3)

[Claims] (1) In a closed fermentation tank, measure the oxygen concentration in the gas phase in the fermentation tank, and when the oxygen concentration decreases, air is supplied to adjust the oxygen concentration in the gas phase to j~/9 (V/V )%
A method for producing vinegar by a static fermentation method, which is characterized by maintaining the vinegar in such a manner. (2) In a closed fermentation tank, measure the oxygen concentration in the gas phase in the fermentation tank, and when the oxygen concentration decreases, air is supplied to adjust the oxygen concentration in the gas phase to j~/9 (V/V )
A method for producing vinegar by a static fermentation method, which is characterized in that the vinegar is maintained at a constant temperature of 10%, and the gas is extracted from the gas phase, the temperature is adjusted, and then the vinegar is returned to the gas phase. (3) A temperature control device that connects at least two points: the closed fermentation tank and the gas phase section 3 in the fermentation tank! and an air supply pipe that opens into a gas phase circulation path consisting of a gas circulation pipe≠ equipped with a gas circulation device B, the fermentation tank/and the circulation pipe≠? and a pressure regulating valve/3 provided in the circulation path.