JPH05244925A - Method of controlling continuous fermentation of fermented alcoholic beverage by using bioreactor - Google Patents

Abstract

PURPOSE:To readily, effectively and continuously produce the subject high- quality fermented alcoholic beverage by using a bioreactor in which a fermentation solution circulates and controlling the fermentation by a specified method. CONSTITUTION:In fermenting while continuously supplying a fermentation raw material. to a bioreactor composed of a raw material supply-opening 1, an outlet pipe discharging a fermented alcoholic beverage and a ceramic filter module 3 formed into a loop shape by a circulation passage and capable of cross flow-filtering a fermented solution, distributing the clarified fermented solution into the outlet pipe and distributing the residual microorganism- containing fermented solution into the circulation passage, a suitable dilution ratio is selected using the specific gravity of the objective fermented solution as an indication. Specifically, a correlation between the cell concentration, the specific gravity of the raw material, the dilution ratio and the specific gravity of the fermented alcoholic beverage is determined in advance. The actual specific gravity of the raw material and the actual cell concentration in the bioreactor are subsequently measured. The measured values are compared with the above-mentioned data so as to select a dilution ratio.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a control method for continuous fermentation of brewed liquor using a bioreactor having a ceramic filter module.

[0002]

2. Description of the Related Art Conventionally, brewed liquor has been produced by a batch fermentation method. That is, taking fruit liquor, which is a typical brewed sake, as an example, the raw material juice is charged into a fermentation tank, the mother of liquor is inoculated into the fermentation tank, the temperature is kept within a certain range, and the fermentation is completed for a certain number of days to complete fermentation Was.

By fermentation, yeast partially assimilates some of the sugars contained in the juice of grapes, apples, etc., which are the raw materials for the fruit wine, to produce alcohol, and at the same time, aroma components such as esters are secreted. A scent is added to fruit wine. To evaluate the quality of the fruit wine produced, in addition to quantitative ones such as the alcohol content and residual sugar concentration of the fruit wine, there are very sensory factors such as the aroma produced by fermentation, the taste and aroma of the ingredients. It is judged by comprehensive evaluation. Normal,
Various fruit liquors with different alcohol content, residual sugar concentration, aroma, etc. are produced depending on the difference in raw materials and the degree of fermentation.

Generally, a plurality of sugars such as glucose, fructose and sucrose are present in the raw material juice in different amounts. In the production of fruit wine, yeast utilizes these sugars for fermentation. In order to know the progress of fermentation by quantitative measurement, the method of measuring these sugar concentrations or alcohol concentrations has been conventionally used, but these concentration values do not always match the quality of fruit wine. Therefore, there is a problem in reliability when performing fermentation control only with these concentration values.

Further, as a method different from the conventional method of knowing the degree of progress of fermentation by quantitative measurement, in the batch fermentation method, the specific gravity value of the actual fermentation liquid is measured using the specific gravity value as an index. Fermentation was controlled by. That is, as the saccharides are consumed and alcohol is produced as the fermentation progresses, the decrease in the specific gravity is monitored, and the fermentation is stopped when the specific gravity is reached to obtain a product. For this reason, the operator had to monitor the specific gravity in order to control the variation of the fermentation period under various conditions.

[0006]

At the same time as the present invention, the present inventors have applied for a novel continuous fermentation method for brewing sake using a bioreactor. The invention of continuous fermentation is
A brewed liquor is produced by performing liquor culture and subsequent continuous fermentation using a bioreactor. By performing continuous fermentation using this bioreactor, it is possible to dramatically reduce the fermentation rate as compared with the conventional batch-type fermentation method.

More specifically, a bioreactor including a ceramic filter module, a heat exchanger, a deaerator, and a circulation pump is connected as a constituent device, and these constituent devices are connected in an arbitrary order to form a loop. In the bioreactor, the fermentation broth is cultivated by circulating the culture solution with the yeast suspended in the bioreactor, and then continuous fermentation is performed in the same bioreactor. Continuous fermentation is performed by collecting the filtrate as brewed sake while filtering a part.

By the way, in the above continuous fermentation method, the feed rate of the raw material to be fed into the bioreactor or the dilution rate calculated from this rate value must be controlled to an appropriate value. This parameter is an important operating parameter in the above continuous fermentation method. This point will be described more specifically. Here, when the dilution rate is D, the feed rate of the raw material is F, and the reactor effective volume is V, D = F / V. Since the reactor effective volume V is a value specific to the bioreactor, in order to control the raw material supply rate F,
The dilution ratio D may be controlled.

And, in order to obtain brewed sake of a predetermined quality,
Dilution rate D (or raw material feed rate F), yeast fermentation rate,
It is necessary to set an appropriate value based on the cell concentration, the raw material, and the type of brewed sake to be produced. The reason is that if the raw material dilution rate D (or the raw material supply rate F) is below an appropriate value, the supplied raw material will stay in the bioreactor for a long time, and therefore, fermentation will proceed excessively, This is because it adversely affects the product. On the contrary, if the raw material dilution rate D (or the raw material supply rate F) exceeds an appropriate value, the raw material is supplied in an amount exceeding the fermentation capacity of the yeast, and the product is filtered without being sufficiently fermented. Is.

Therefore, in the present invention, in a method for continuously producing brewed liquor of excellent quality using a bioreactor, continuous fermentation of brewed liquor by a simple and effective bioreactor for giving an appropriate value for the dilution rate D It aims at providing the control method of.

[0011]

Means for Solving the Problems In order to solve the above problems, the present invention provides a raw material supply port, an outlet pipe for discharging fermented brewed sake, a cross-flow filtration of the fermentation liquid, and a fermentation liquid. Part of the permeated liquid that permeates and is clarified is distributed to the outlet pipe, and a ceramic filter module having the function of distributing the fermentation liquid containing the remaining microorganisms to the circulation path Using a bioreactor in which the ceramic filter module is formed in a loop shape by a circulation path, while continuously supplying the fermentation raw material to the bioreactor, an appropriate dilution rate using the specific gravity of the target fermentation broth as an index A method for controlling continuous fermentation of brewed liquor by a bioreactor characterized in that brewed liquor of appropriately fermented quality is obtained by selecting and fermenting brewed liquor.

Further, according to the present invention, a raw material supply port for supplying a fermentation raw material, an outlet pipe for discharging a fermented brewed liquor, a cross-flow filtration of the fermentation liquid, and a part of the fermentation liquid A ceramic filter module having a function of distributing a permeated liquid that is permeated and clarified to an outlet pipe and a fermentation liquid containing the remaining microorganisms to a circulation path, and brewing to be discharged provided in the outlet pipe A flow rate control valve for controlling the flow rate of liquor, a flow meter for measuring the flow rate of brewed liquor provided downstream of the flow rate control valve, and the flow meter installed between the flow rate control valve and the flow meter. A flow rate controller capable of performing feedback control of the opening / closing degree of the flow rate control valve according to the value indicated by Using a bioreactor in which the module is formed in a loop by a circulation path, while continuously supplying fermentation raw materials to the bioreactor, select an appropriate dilution rate using the specific gravity of the target fermentation broth as an index. A method for controlling continuous fermentation of brewed liquor by a bioreactor, which is characterized by obtaining appropriately fermented brewed liquor by performing fermentation.

Further, in the present invention, in order to control continuous fermentation using the above bioreactor, the conditions of cell concentration, specific gravity and dilution rate of fermentation raw material, and specific gravity of the target fermentation broth are set. The correlation is investigated in advance, and based on this correlation, an appropriate dilution rate is selected from the values obtained by measuring the actual specific gravity of the fermentation raw material and the bacterial cell concentration. Further, the present invention, a raw material supply port for supplying the fermentation raw material, an outlet pipe for discharging the fermented brewed liquor, cross-flow filtration of the fermentation liquid, a part of the fermentation liquid is permeated. A ceramic filter module having a function of distributing the permeated liquid to be clarified to the outlet pipe and distributing the fermentation liquid containing the remaining microorganisms to the circulation path, and the flow rate of the brewed liquor discharged in the outlet pipe. A flow rate control valve for controlling the flow rate, a flow meter provided downstream of the flow rate control valve for measuring the flow rate of brewed sake, and a value indicated by the flow meter installed between the flow rate control valve and the flow meter. According to the flow rate control valve, the degree of opening and closing of the flow rate controller can be feedback-controlled, and the optimal dilution rate is automatically calculated and the dilution rate calculated by the flow rate controller is calculated. Using a bioreactor having the above-mentioned components consisting of a diluting rate controller that can be obtained, and a ceramic filter module formed in a loop shape by a circulation path, bacterial cell concentration, specific gravity of fermentation raw material, raw material supply The data of the correlation of the specific gravity of the brewed liquor with the desired quality and each speed (or dilution rate) data is input in advance to the dilution rate controller. The actual material specific gravity and the bacterial cell concentration in the bioreactor are input to the dilution rate controller. By inputting and calculating the optimal dilution rate for obtaining brewed sake having the desired quality in the dilution rate controller and performing fermentation by giving the obtained optimal dilution rate as a set value to the flow rate controller, the fermentation is appropriately performed. A method for controlling continuous fermentation of brewed liquor by a bioreactor characterized by obtaining brewed liquor of the specified quality.

An example of the structure of a bioreactor for carrying out continuous fermentation of brewed sake is shown in FIG. The bioreactor shown in FIG. 1 includes a raw material supply port 1, a circulation pump 2, a ceramic filter module 3, a heat exchanger 4, and a deaeration unit 5. Each of these components is connected in a loop in an arbitrary order so that the culture solution or the fermentation solution is circulated.
The culture or fermentation broth is present in the bioreactor and reacts and ferments with the yeast everywhere in the loop of the bioreactor.

The raw material is continuously supplied from the raw material supply port 1,
When the circulation pump 2 circulates in the bioreactor,
In this bioreactor, fermentation is carried out in contact with yeast,
Alcohol is produced. When the fermented liquid passes through the ceramic filter module 3, a part thereof is filtered and taken out as brewed sake. As the ceramic filter module 3 used in the bioreactor, a module is used in which one or more tubular membrane elements having a filter function are bundled, housed in a container, and integrated. This tubular membrane element is porous with a pore size that allows fermentation brewed sake to pass through without passing through microorganisms such as yeast, and the permeation flux as much as possible (permeate per unit membrane area per unit time) It is desirable that the value is large. Further, the membrane structure is an asymmetric structure, that is, a structure composed of a dense layer having a permeation performance and a porous support layer supporting the dense layer, which enhances the permeation performance and the strength of the membrane as a whole. is there. Further, as the material of the membrane element, a material such that the ceramic filter module 3 can withstand steam sterilization and chemical cleaning, for example, zirconia ceramic or alumina ceramic is preferably used.

The filtration using the ceramic filter module 3 is so-called cross-flow filtration in which the filtration is performed in a direction perpendicular to the flow direction of the liquid. FIG. 2 shows a conceptual diagram of cross-flow filtration. As shown in FIG. 2, the feed liquid supplied in the longitudinal direction of the membrane element is filtered in the direction perpendicular to the flow direction. In this cross-flow filtration, if the liquid flow velocity on the membrane surface of the membrane element is sufficient, for example, the flow velocity on the membrane surface is 2 to 4 m / sec, the circulation flow becomes a nearly completely mixed state and circulates inside the reactor.

The heat exchanger 4 serves to suppress heat accumulation due to the operation of the circulation pump 2 and adjust the temperature to a temperature suitable for culturing or fermentation of microorganisms. In addition, in the initial stage of culture or fermentation, the optimum temperature may not be reached, so at that time, the culture solution or fermentation solution is heated by the heat exchanger 4. The deaerator 5 is for removing bubbles as soon as carbon dioxide is generated and bubbles are generated in the fermentation liquid during operation of the device when fermenting brewed sake with yeast. is there.

The bioreactor used in the present invention has a flow rate adjusting valve 9 for adjusting the amount of brewed liquor discharged from the ceramic filter module 3. In this flow rate adjustment control, feedback control is performed using a flow rate controller 8 capable of controlling the degree of opening / closing of the flow rate adjustment valve 9 by the amount indicated by a flow meter 7 provided downstream of the flow rate adjustment valve 9.

Next, the control method of the present invention will be described. In the continuous fermentation using the bioreactor as described above, in order to obtain a brewed liquor of a predetermined quality, the raw material supply rate of the continuously supplied raw material or the dilution rate calculated from this raw material supply rate is set to an appropriate value. It is an indispensable condition to set to become. In order to set the dilution rate to an appropriate value, it is necessary to set it to an appropriate value based on the fermentation rate of yeast, the cell concentration, the type of raw material, and the type of brewed sake to be produced.

Here, the dilution rate is D, the raw material supply rate is F,
When the reactor effective volume is V, the dilution ratio D is D = F /
Indicated by V. In the present invention, the relationship between the specific gravity and the sugar content in the production process of brewed liquor is linear, and it has been empirically found that the relationship between the quality and specific gravity of brewed liquor is empirically correlated. The optimum control method of the dilution rate D, which is the operating parameter of the bioreactor used in the present invention, was found by utilizing the fact that the quality judgment can be determined to some extent and by using the specific gravity as an index.

In the present invention, the specific gravity of the fermentation raw material is measured,
Planning how much to reduce from that value to the specific gravity of the final fermented brew, that is, how much to ferment, and to determine the feed rate (or dilution rate D) of the raw material to the bioreactor Controls the operation of the bioreactor. One of the control methods of the present invention is to find out the correlation from these experimental data based on experimental data collected by trial and error, and determine the optimum raw material supply rate for producing the desired brewed liquor. Is the way to do it. This method is as follows. For example, in laboratory-level studies, experiments are conducted by changing conditions such as bacterial cell concentration, specific gravity of fermentation raw material, raw material supply rate (or dilution rate), and obtain correlation data with specific gravity of brewed sake. . Save those correlations as data. Next, the specific gravity of the raw material to be fed into the actual bioreactor and the bacterial cell concentration in the bioreactor are measured, and the correlation is investigated from the previously stored data, and the brewed liquor of the desired quality is measured. Select the optimal dilution rate to obtain Based on this data, for example, by measuring the bacterial cell concentration and the specific gravity of the raw fruit juice in a bioreactor for the purpose of actually producing fruit liquor, the optimal raw fruit juice supply to obtain the fruit liquor of the desired product is obtained. Speed (or dilution rate)
Example 1 shows in detail the control of continuous fermentation.

Next, for further automation, the correlation between each data of the bacterial cell concentration, the specific gravity of the raw material juice, the raw material supply rate (or the dilution rate) and the specific gravity of the fruit liquor having a preferable quality was investigated in advance. The actual specific gravity of the fermentation raw material and the bacterial cell concentration in the bioreactor are input to the dilution rate controller 10 in which the data obtained is input, and the optimum dilution rate for obtaining fruit wine having the desired quality is automatically calculated. Example 2 shows a method of automatically controlling fermentation by calculating the optimum dilution rate and giving the obtained optimum dilution rate to the flow rate controller 8 as a set value.

In the following examples, an example of fruit liquor using fruit juice as a fermentation raw material was shown, but the control method of the present invention can use any fermentation raw material as long as it can be applied to brewing liquor. is there. For example, fermentation can be carried out by the control method of the present invention using a saccharified liquid of rice or rice koji as a fermentation raw material.

[0024]

Example 1 FIG. 3 shows a control block diagram of a bioreactor used in the control method of this example. In the method of this example, experiments are conducted under various conditions in advance to understand the relationship between the bacterial cell concentration, the specific gravity of the raw fruit juice, the specific gravity of the fruit wine and the dilution rate. Of course, it is more effective to make a database of the data obtained by using the knowledge information processing technology.

Apple juice, which is a raw material, is charged into a bioreactor, and seed yeast is inoculated. While the yeast is suspended in the culture solution, the circulation pump 2 circulates the inside of the bioreactor to culture the mother liquor. The liquor culture is carried out in a batch state until the cell concentration reaches a predetermined level. That is, the batch culture is a culture in the first half of the liquor culture, which is performed without supplying the fermentation raw material to the bioreactor charged with the fermentation raw material at the time of culturing the liquor and without opening the flow rate adjusting valve 9. In other words, there is no substance in and out of the bioreactor, and the culture is performed while the culture solution is circulated in the bioreactor.
After the first half of the liquor culture, continuous culture, which is the second half of the liquor culture, is performed, and high-density culture is performed until a predetermined bacterial cell concentration is reached.

Next, environmental conditions such as temperature are adjusted to those suitable for fruit wine production, and continuous fermentation of fruit wine is started. At this time, the specific gravity of the raw fruit juice and the bacterial cell concentration in the fermentation broth were measured by manual analysis or an online sensor, and the bacterial cell concentration obtained by the above-mentioned experiment, the specific gravity of the raw juice, and the specific gravity and dilution of the fruit wine to be produced were diluted. The optimum dilution rate is selected based on the data of the rate correlation, and a predetermined value is input to the flow rate controller 8. The flow rate controller 8 controls the flow rate adjusting valve 9 so that the set flow rate is achieved, and feedback control is performed by the flow meter 7 provided further downstream. The bacterial cell concentration was determined from the correlation between the OD value (turbidity) and the number of bacteria determined in advance.

An example of the optimum dilution rate data is shown in Table 1 below.

[0028]

[Table 1]

The meaning of the data in Table 1 is that when the cell concentration of the fermentation broth is 5 × 10 ⁸ cells / ml and the specific gravity of the raw material to be supplied is 1.0505, fruit wine having the required specific gravity is obtained. It shows what kind of value should be selected for the dilution rate in order to obtain it. This means that, as described above, the specific gravity of the final product differs depending on the raw materials used and the type of brewed liquor to be produced. It can be known from the data shown.

Therefore, by measuring and monitoring the specific gravity of the product, the fruit wine having the desired quality, that is, the quality of the fruit wine and the specific gravity of the fruit wine are correlated, so that the fruit wine having the desired specific gravity is produced. In order to do so, the fermentation is performed by using the specific gravity of the target product as an index and selecting the dilution rate as described above so that the specific gravity can be obtained. FIG. 5 shows changes over time in the specific gravity of the fermented liquor and the number of yeast cells when the dilution ratio was set to 0.08 for the example in which fruit wine fermentation was actually performed using this correlation data.
Is shown in the graph. The experiment on the graph of FIG.
Using a volume bioreactor, set the specific gravity of the raw juice to 1.0
Fermentation was carried out at a cell concentration of 5 × 10 ⁸ cells / ml.

In the case of the present embodiment, the first examination
Is a bacterial cell concentration of 2 × 10⁸~ 7 × 10 ⁸cell / ml
However, the actual implementation conditions were
Judgment based on setting conditions (mainly membrane area) and product quality
And the cell concentration is 5 × 10⁸cell / ml. The above
The raw material specific gravity of the optimum dilution ratio data shown in Table 1 is 1.0505,
Cell concentration 5 × 10 ⁸Specific gravity 1.02 from cell / ml
To obtain a product around 4, the dilution rate should be 0.08
Therefore, it is actually continuous at a dilution rate of 0.08.
When fermented, specific gravity 1.0232-1.0239
The fruit wine was obtained.

From FIG. 5, when the fermentation of fruit liquor was carried out using the bioreactor under the above conditions, if the fermentation was carried out at a dilution ratio of 0.08, the specific gravity of the fruit liquor of the product was 1.0232-32.
It can be made almost constant at 1.0239, indicating that fruit wine of constant quality was obtained.

[0033]

[Embodiment 2] This embodiment takes automation into consideration, and shows a method for automatically obtaining the optimum dilution rate from the specific gravity of the raw fruit juice and the bacterial cell concentration. That is, in the present example, in the bioreactor of Example 1, the operator directly inputs an appropriate dilution rate to the flow rate controller, but an appropriate dilution rate is automatically selected by the dilution rate controller. It is something that can be done.

A block diagram of the bioreactor used in this example is shown in FIG. In addition to the block diagram of the first embodiment, the optimum dilution rate is automatically calculated, and the flow rate controller 8
The dilution rate controller 10 capable of giving the calculated dilution rate is used. The dilution rate controller 1
Although 0 may be any type of device, a computer (personal computer, minicomputer, etc.) is advantageous in view of program development, operability, flexibility, and expandability.

The dilution ratio controller 10 is preliminarily input with the data of the correlation between the cell density, the specific gravity of the fermentation raw material, the raw material supply rate (or the dilution rate) and the specific gravity of the brewed liquor having a preferable quality. , The specific gravity of the raw material juice actually used, the bacterial cell concentration in the bioreactor is input by the manual analysis result, or is automatically input from the online sensor,
Here, the optimum dilution rate is determined by comparing and calculating, and further the obtained dilution rate is instructed to the flow rate controller 8. There are various possible calculation methods, but an appropriate program should be developed each time. As an example, there is a method of expressing the active state of yeast by a specific consumption rate ν which is a biochemical engineering parameter, and obtaining an optimum value of the dilution rate D using a calculation formula derived from a mass balance formula. An example of producing sparkling cider liquor using the same is shown.

In general, the substance balance equation relating to the substrate concentration S in a continuous culture system is represented by the following equation (1). V (ds / dt) = - V (ds / dt) c + FS f -FS formula (1) V: Fermentation liquid amount F: medium feed rate S _f: substrate concentration in the feed medium S: substrate concentration in the culture tank (Ds / dt): Substrate concentration change in the fermenter (ds / dt) _c : Substrate consumption rate by microorganisms Both sides of (1) are divided by V to obtain the following formula (2).

(Ds / dt) = − (ds / dt) _c + D (S _f −S) Formula (2) D = F / V: Dilution rate On the other hand, the specific consumption rate ν is the substrate consumption rate and the bacterial cell concentration. It is defined as being divided by, and is expressed by the following equation (3). ν = (ds / dt) _c / X Equation (3) X: Cell concentration By substituting Equation (3) into Equation (2), the following Equation (4) is derived.

(Ds / dt) = − ν · X + D (S _f −S) Formula (4) A state in which the substrate input and the consumption by the microorganism are balanced, and in the steady state (ds / dt) = 0. Therefore, the equation (4) in this state is represented by the following equation (5). D = ν · X / (S _f −S) Formula (5) In the case of apple fermentation, the sugar contained in the apple juice, which is a substrate, is a mixture of multiple types of glucose, fructose, sucrose, etc. Is not a single sugar source and therefore cannot provide a substrate concentration S in the bioreactor. Therefore, since the relationship between the specific gravity and the sugar content is linear and the specific gravity changes with the consumption of sugar and the production of alcohol, in this example, the substrate concentration S of the formula (5) was replaced with the specific gravity ρ to obtain the dilution ratio. D was calculated. Therefore, the equation (5) can be rewritten as the following equation (6).

D = ν · X / (ρ _f −ρ) Formula (6) ρ _f : Specific gravity of raw fruit juice ρ: Specific gravity of target cider liquor Based on formula (6), a dilution rate controller using a personal computer The appropriate dilution rate was calculated at 10, and the obtained dilution rate D was automatically given to the flow rate controller 8 as a set value to perform apple sake fermentation.

Since ν takes various values depending on the culture environment at that time and the type of yeast, it is necessary to obtain it in advance by experiments. X is measured as an OD value, a dry cell concentration, and a viable cell count by a conventional method or sampling or online measurement. In the case of the present embodiment, O by a laser turbidimeter
The D value was used as is. The software of the personal computer made it possible to measure the OD value online, and the operator could directly input the specific consumption rate ν and the specific gravity value. In addition, since the specific consumption rate ν may change depending on the sugar concentration level, data for which the correlation with the specific gravity is investigated is prepared in advance.

The graph of FIG. 6 shows the result of continuous fermentation by actually performing a predetermined calculation with a personal computer, transferring the set value to the flow rate control device. The method of this continuous fermentation will be described below. After carrying out liquor culture using a bioreactor with a volume of 6 liters, continuous fermentation was carried out at a dilution rate of 0.04. During this period, the specific gravity of the produced apple liquor was 1.012.
Here, the operator was instructed to produce apple wine having a specific gravity of 1.015. In the flow rate controller 8, the calculation for obtaining the dilution rate D based on this instruction was performed as follows. Based on the data of the specific consumption rate ν obtained experimentally, ν = 1.85 × 10 ⁻⁵ , the measured value of the bacterial cell concentration X 9
4.8, 1.050 of the measured specific gravity of the raw material juice was substituted into the above formula (6) to calculate a dilution ratio D = 0.05. In the flow rate controller 8, the dilution rate 0.05 is further converted into a raw material supply rate, and the obtained raw material supply rate of 300 ml / h is given to the flow rate controller 8 as a set value. In this way, fermentation was performed by controlling the raw material supply rate. As a result, the specific gravity finally becomes 1.0152.
We got apple cider in the vicinity.

Further, the operator has a specific gravity of 1.02.
Instructions were given to produce 3 products. At this time, in the flow rate controller 8, the measured value of the bacterial cell concentration X is 94.3, the value of the specific substrate consumption rate ν is 2.27 × 10 ⁻⁵ , and the specific gravity value of the raw material juice is 1.050. To obtain a value of dilution rate D = 0.08. The flow rate controller 8 further converted the dilution rate of 0.08 into the raw material supply rate, and the obtained raw material supply rate of 480 ml / h was given to the flow rate controller 8 as a set value. In this way, fermentation was performed by controlling the raw material supply rate. As a result, apple cider having a specific gravity of around 1.0235 was finally obtained.

As described above, according to the control method of the present embodiment, it is possible to derive a simple characteristic formula and obtain the optimum dilution rate using the specific gravity value. In addition, online measurement items can be enhanced to allow fully automatic optimum operation. Further, in the case of the present embodiment, a simple characteristic expression is used, but by using a knowledge information processing means, fuzzy control, a neural network, etc., more flexible optimum control is possible.

[0044]

Since the present invention is configured as described above, it has the following effects. (1) It is possible to control the dilution rate using the specific gravity as an index. (2) The optimum value of the dilution rate can be set by using the specific gravity of the target fermentation broth as an index by conducting an experimental study in advance and ascertaining the relationship between the specific gravity of the raw material, the bacterial cell concentration, and the specific gravity of the product.

(3) By selecting initial conditions such as selection of raw materials, selection of yeast, fermentation temperature, and cell concentration and controlling the dilution rate, brewed liquors of various qualities can be continuously and at high speed. Can be produced. (4) It is possible to automatically control the dilution rate by creating a control characteristic formula based on the fermentation characteristics obtained in the preliminary examination and by performing knowledge information processing such as database, fuzzy, and neural network.

(5) By performing on-line measurement of the specific gravity of the fermentation broth and the bacterial cell concentration, automatic control becomes easy.

[Brief description of drawings]

FIG. 1 shows the configuration of a bioreactor for continuous fermentation of brewed sake.

FIG. 2 shows a conceptual diagram of cross-flow filtration.

FIG. 3 shows a control block diagram of a bioreactor used in an example.

FIG. 4 shows a control block diagram of a bioreactor used in another embodiment.

FIG. 5: Specific gravity of the fermentation broth when the dilution rate is 0.08,
The time-dependent change of the number of yeast cells is shown.

FIG. 6 is a graph of FIG. 6 showing a result of continuous fermentation by performing a predetermined calculation by a personal computer, transferring a set value to a flow rate control device.

[Explanation of symbols]

 1 Raw Material Supply Port 2 Circulation Pump 3 Ceramic Filter Module 4 Heat Exchanger 5 Degassing Section 6 Brewing Sake 7 Flow Meter 8 Flow Controller 9 Flow Control Valve 10 Dilution Ratio Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiko Seike 63-30 Yuhigaoka, Hiratsuka-shi, Kanagawa Sumitomo Heavy Industries, Ltd. Hiratsuka Laboratory (72) Inventor Kunio Yuki 4-1-5 Shinjuku, Higashi-chu, Kashiwa, Chiba ( 72) Inventor Masayuki Tanabe 146-401, Kosokudai, Matsudo City, Chiba Prefecture

Claims (4)

[Claims] (1) Raw material supply port, outlet pipe for discharging fermented brewed sake, cross-flow filtration of fermentation broth, and a part of the fermentation broth permeates to be clarified The liquid is distributed to the outlet pipe, and the ceramic filter module having the function of distributing the fermentation liquid containing the remaining microorganisms to the circulation path is provided, and the ceramic filter module is provided with a loop shape by the circulation path. By using the formed bioreactor, (2) by performing fermentation while continuously supplying the fermentation raw material to the bioreactor, selecting an appropriate dilution rate using the specific gravity of the target fermentation solution as an index , A method for controlling continuous fermentation of brewed liquor by a bioreactor, which comprises obtaining brewed liquor of appropriately fermented quality. 2. A raw material supply port for supplying a fermentation raw material, an outlet pipe for discharging a fermented brewed liquor, and a cross-flow filtration of the fermentation liquid to partially permeate the fermentation liquid. And a clarified permeate to be distributed to the outlet pipe, and a ceramic filter module having a function of distributing the fermentation liquid containing the remaining microorganisms to the circulation path, and the brewed liquor discharged from the outlet pipe. A flow rate control valve for controlling the flow rate of the brewery, a flow meter provided downstream of the flow rate control valve for measuring the flow rate of the brewed liquor, and a flow meter installed between the flow rate control valve and the flow meter. A flow rate controller capable of performing feedback control of the opening / closing degree of the flow rate control valve according to the indicated value. Using a bioreactor in which the loop is formed in a loop by a circulation path, (2) while continuously supplying the fermentation raw material to the bioreactor, an appropriate dilution rate using the specific gravity of the target fermentation broth as an index. A method for controlling continuous fermentation of brewed liquor by a bioreactor, wherein brewed liquor of appropriately fermented quality is obtained by selecting and fermenting. 3. A method for selecting an appropriate dilution rate using the specific gravity of the target fermentation broth as an index is such that the conditions such as the bacterial cell concentration, the specific gravity and the dilution rate of the fermentation raw material, and the specific gravity of the target fermentation broth are preliminarily set. The method for controlling continuous fermentation of brewed liquor by a bioreactor according to claim 1 or 2, characterized in that an appropriate dilution rate is selected based on this correlation. 4. A raw material supply port for supplying a fermentation raw material, an outlet pipe for discharging fermented brewed liquor, and a cross-flow filtration of the fermentation liquid to partially permeate the fermentation liquid. And a clarified permeate to be distributed to the outlet pipe, and a ceramic filter module having a function of distributing the fermentation liquid containing the remaining microorganisms to the circulation path, and the brewed liquor discharged from the outlet pipe. A flow rate control valve for controlling the flow rate of the brewery, a flow meter provided downstream of the flow rate control valve for measuring the flow rate of the brewed liquor, and a flow meter installed between the flow rate control valve and the flow meter. A flow controller that can feedback-control the opening / closing degree of the flow control valve according to the indicated value, and an optimal dilution ratio that is automatically calculated and calculated by the flow controller. Dilution factor controller that can provide the rate,
A bioreactor having the above-mentioned components and having a ceramic filter module formed in a loop by a circulation path, and (2) bacterial cell concentration, specific gravity of fermentation raw material, raw material supply rate (or dilution rate) ) And the data of the correlation of the specific gravity of the brewed liquor having a preferable quality are input in advance, the actual material specific gravity and the bacterial cell concentration in the bioreactor are input to the dilution rate controller, and (3) the dilution is performed. The rate controller automatically calculates the optimum dilution rate for obtaining fruit wine with the desired quality, and (4) the fermentation is performed by giving the obtained optimum dilution rate to the flow rate controller as a set value for fermentation. A method for controlling continuous fermentation of brewed liquor by a bioreactor, which is characterized by obtaining fermented brewed liquor of fermented quality.