JPH0425792B2 - - Google Patents

Abstract

PURPOSE:To provide an apparatus enabling continuous anaerobic fermentation without necessitating immobilization of microorganisms, by dividing a closed vessel with a porous alumina fiber partition wall adsorbed with suspension or microorganisms, supplying a substrate to one of the divided section and taking out the fermentation liquid out of the other section. CONSTITUTION:An alumina fiber wall 2 composed mainly of aluminum oxide and silicon oxide and having a number of pores of 30-300mu diameter and a prescribe thickness is adsorbed with a suspension of microorganisms and placed in a closable fermentation vessel 1 to divide the vessel into sections. A substrate supplying port 5 is opened in one section and a discharging port 6 of fermentation liquid is opened in the other section.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing fermented foods and an apparatus therefor. (Conventional technology) Conventional fermented food manufacturing equipment uses alginic acid.
The immobilized microbial cells are immobilized on bead-shaped carriers using polysaccharides such as Na, K, carrageenan, or agar, and synthetic polymers such as photocrosslinkable resins by entrapment method, and then transferred to a sealed fermenter. Put the required amount inside,
In some fermenters, a substrate is injected into the fermenter, and the immobilized bacterial cells are brought into contact with the substrate in an anaerobic manner for fermentation, whereby the fermented liquid is continuously taken out. (Problems to be Solved by the Invention) However, it is a very difficult task to prepare a large amount of carriers in the form of beads on which bacterial cells are immobilized by the entrapment method, and the carriers mentioned above are made of organic substances. Therefore, the mechanical strength of the carrier itself is relatively low and it is likely to be crushed if reacted for a long time, so it could not be used for a long time. Furthermore, these immobilized microbial cells have the problem of low mass transfer efficiency and poor reaction efficiency due to the microbial cells being surrounded by a carrier. In addition, since the invasion of various bacteria is unavoidable while the immobilized bacterial cells are placed in the fermenter,
There were problems with product quality deterioration, spoilage, etc., or with the safety of immobilized bacterial cells. The present invention was developed as a result of intensive research in view of the above points, and it can easily immobilize bacterial cells, withstand long-term use, and increase reaction efficiency. It is an object of the present invention to provide a method for producing fermented foods and an apparatus therefor, in which sterilization is possible and continuous anaerobic fermentation can be carried out without invasion of germs from the outside. (Means for Solving the Problems) That is, the inventor brought a hydrolyzed solution of a fermentation raw material into contact with immobilized microbial cells obtained by adsorbing and immobilizing fermentation microbial cells on an alumina fiber wall under anaerobic conditions. Knowing that fermentation can dramatically increase the fermentation efficiency of bacterial cells and efficiently obtain fermented liquid for a long period of time in a short period of time, we have developed the method and apparatus for producing fermented foods and brewed foods of the present invention. completed. The first invention of this application is made by bonding alumina fibers mainly composed of aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) to form pores of 30 to 300 microns. After the bacterial cell suspension is absorbed into the alumina fiber wall and the bacterial cells are adsorbed and fixed in the pores of the alumina fiber wall, the substrate is passed through the pores of the alumina fiber wall under anaerobic conditions. A method for producing a fermented food, which is characterized in that the fermented food is brought into contact with bacterial cells and fermented. An alumina fiber wall formed by bonding alumina fibers mainly composed of aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) that have absorbed liquid so as to form pores of 30 to 300 microns; Under anaerobic conditions, the substrate passes through an injection chamber formed in the fermentation vessel by the alumina fiber wall, into which the substrate is injected, and a hole in the alumina fiber wall, which is also formed in the fermentation vessel by the alumina fiber wall. This is a fermented food manufacturing device characterized by comprising a recovery chamber for recovering the fermented liquid that passes through the device. These inventions will be described in detail below. First, the method for producing a fermented food according to the first invention of this application will be explained. Fermented raw materials used in the present invention include those commonly used in the production of fermented foods such as soy sauce, alcohol, beer, wine, citric acid, or lactic acid. These raw materials are subjected to conventional raw material processing, including softening of the raw material structure, denaturation of proteins, gelatinization of starch, and sterilization. Next, the fermentation raw material may be hydrolyzed by an enzyme using either an enzyme agent or a method in which the fermentation raw material is hydrolyzed using koji, but the former is particularly preferred from the viewpoint of the hydrolysis operation. Next, the above fermentation raw materials are enzymatically or chemically hydrolyzed, and if the pH is not around 3 to 7, either lactic acid fermentation is performed, or acid is added to raise the pH to 3.
Adjust to about 7. In addition, lactic acid fermentation is carried out using the above-mentioned hydrolyzate, for example, Pedeiococcus soae IAM1673.
(ATCC13621), Pedeiocoticus soae
IAM1681 (ATCC13622), Pedeiococcus soae IAM1685 (ATC13623), Pedeiococcus halovirus IAN1693, etc., or their culture solution is added and kept at 25-35℃ under anaerobic conditions with occasional or continuous mechanical stirring. and undergo lactic acid fermentation. In this case, the lactic acid bacteria cells may be prepared using a conventional method or by using immobilized lactic acid bacteria cells immobilized on fibrous ceramics or spherical ceramic packing bodies, and bringing this into contact with the hydrolyzate to perform lactic acid fermentation. . Alternatively, instead of the lactic acid fermentation described above, organic acids such as lactic acid and acetic acid or inorganic acids such as hydrochloric acid and sulfuric acid are added to the hydrolyzed fermentation raw material, and the pH of the hydrolyzed product is adjusted to about 3 to 7. Good too. If the hydrolyzed product is in a liquid state containing little or no decomposition residue (solid content), use it as is; if not, use the above-mentioned lactic acid fermentation or add acid and press in a conventional manner.
Solid-liquid separation is performed by operations such as filtration and centrifugation to obtain a liquid substrate. Next, the liquid state obtained by hydrolyzing the above-mentioned fermentation raw material is made into immobilized bacteria by adsorbing and immobilizing the bacteria by absorbing the suspension into the alumina fiber wall using a conventional method. Yeast fermentation is carried out under anaerobic conditions at an appropriate temperature, for example, about 20 to 35°C. The alumina fiber wall is made by forming pores of 30 to 300 microns between alumina fibers whose main components are aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) using a colloidal silica or sulfuric acid binder. Combined with wall shape, 700~
It is made by firing at 1400℃, and its main components are aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ).
The reason for this is that it is easy to mold into a fiber shape,
It has good affinity with yeast, etc. In addition, the pore diameter was set in the range of 30 to 300 microns because yeast cells of approximately 5 microns can easily pass through and be immobilized. The above-mentioned alumina fiber was used as a carrier for immobilization, and
Since the alumina fiber wall is bonded to form a pore of 300 microns in the form of a wall, it is possible to obtain the effect of easily adsorbing yeast. For example, in the case of soy sauce production, the soy sauce yeast to be immobilized is, for example, Satucharomyces.
Ruxi ATCC13356, Satscharomyces ruxi ATCC14679, Satscharomyces ruxi
ATCC14680, Torulopsis nodaensis
ATCC20189, Torulopsis Magnolia
ATCC13782, Torulopsis ethiersii
ATCC20190, Torulopsis spheerica
ATCC13193, Torulopsis fuersatilis
ATCC20191, Torulopsis salmon, Torulopsis halophyllus, Torulopsis anorama
One or more types of yeast such as ATCC20222 are preferably used. Next, a method for obtaining immobilized microbial cells by absorbing the suspension of microbial cells into the alumina fiber wall and adsorbing and immobilizing the microbial cells will be described. First, a suspension obtained by adding, for example, a solution of glucose, yeast extract, etc. to the above-mentioned bacterial cells is sent by an appropriate means such as a peristaltic pump, and the bacterial cells are adsorbed and immobilized by being absorbed into the alumina fiber wall. to obtain the above-mentioned immobilized bacterial cells. Next, the immobilized bacterial cells obtained by the above operation are placed in a fermentation container, and the hydrolyzed fermentation raw material is poured into the container, and fermentation is carried out under anaerobic conditions while contacting with the immobilized bacterial cells. to obtain the fermentation liquid. The fermentation vessel may be of any type, such as a film reaction vessel, a stirring vessel, a cylindrical vessel, a vessel partitioned with ceramic adsorption plates, a vessel filled with small spherical ceramics, and the like. In addition, the above-mentioned anaerobic conditions refer to conditions where no aeration is performed or where the space of the fermentation vessel is exposed to carbon dioxide gas,
This means a state in which the gas has been replaced with nitrogen gas, etc. The fermentation time under the above anaerobic conditions is 5 hours or more, preferably about 20 to 120 hours.
Contact and fermentation are preferable. The above-mentioned fermentation type can be suitably selected from batch type, continuous type, etc. In addition, if the number of bacteria is insufficient at the time of adsorption of the bacteria, the bacteria can be pre-cultured for an appropriate period of time under conditions suitable for the growth of the bacteria. After that, the fermentation raw material may be brought into contact with a hydrolyzed product for fermentation. Next, the fermented food manufacturing apparatus according to the second invention of this application will be explained. As shown in FIG. 1, a cylindrical alumina fiber wall 2 is attached to a cylindrical fermentation vessel 1, and the fermentation vessel 1 is partitioned by this. An injection chamber 15 is formed into which the substrate is injected, and a recovery chamber 16 is formed in the fermentation vessel 1 by the alumina fiber wall 2 in which the substrate passes through the alumina fiber wall 2 and recovers the fermented liquid. Further, a draft tube 3 is provided inside the alumina fiber wall 2, and a rotating blade 4 driven by an electric motor 9 provided on the upper part of the fermentation container 1 is installed inside the draft tube 3.
is provided. The injection chamber 15 is provided with a substrate supply port 5, and the recovery chamber 16 is provided with a fermentation liquid discharge port 6. Furthermore, a steam intake port 12 and a drain valve 7 are provided below the steam intake port 12 at the bottom of the fermentation vessel 1. The alumina fiber wall 2 is made of alumina fibers whose main components are aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) with colloidal silica or sulfuric acid binder to form pores of 30 to 300 microns. Combined to form a wall and heated to 700-1400℃
The main ingredients are aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) because they are easy to mold into fibers and have good affinity with yeast. be. Further, the pore diameter was set in the range of 30 to 300 microns because it could be appropriately selected depending on the size of the bacterial cells to be used. The alumina fiber wall 2 is supported by a mesh-like metal material 8 around its outer periphery in order to increase its mechanical strength and ease of insertion and removal. This alumina fiber wall 2 is fixed to the fermentation vessel 1 with a mounting bracket 11. Incidentally, in order to increase the strength of the alumina fiber wall 2 itself, glass fiber or the like may be added. Also, if the bacterial cells used for fermentation are small,
By mixing diatomaceous earth or SiO ₂ , an alumina fiber wall 2 having pores with a pore diameter of 30 microns or less can be obtained. Next, a case will be described in which, for example, alcohol is continuously fermented in the fermentation vessel 1 described above. First, before supplying the substrate to the fermentation vessel 1, steam is supplied from the steam intake port 12 at the bottom of the fermentation vessel 1,
The inside of the fermentation container 1 is completely sterilized. Next, the drain valve 7 is opened and the residue inside the fermentation container 1 is discharged. Next, from the supply port 5, the bacterial cells cultured in a separate device, Saccharomyces cerevisiae ellipsoi (S: cerevisiae
varellipsoideus) with glucose added to suspend the cells. This suspension of bacterial cells is absorbed into the alumina fiber wall 2. Next, the substrate (5% glucose solution) is injected into the injection chamber 15 from the supply port 5. Injection chamber 15 of fermentation vessel 1
The substrate injected into the alumina fiber wall 2 passes through the alumina fiber wall 2 and leaches into the recovery chamber 16 formed by the alumina fiber wall 2. At this time, the substrate comes into contact with the bacterial cells immobilized within the alumina fiber wall 2. Alcohol fermentation takes place and the bacterial cells proliferate. The sugar concentration of the fermented liquid overflowing from the discharge port 6 is measured by a biosensor, and is returned to the supply port 5 until the sugar concentration becomes lower than a predetermined value. When the sugar concentration reaches the target value, the fermented liquid is not returned to the supply port 5 but is transferred to the alcohol storage tank. Then, the substrate is continuously supplied from the supply port 5. This supply amount is adjusted according to the measured value of the biosensor. During fermentation,
The bacterial cells inside the alumina fiber wall 2 flow out in proportion to their multiplication, but the amount always required is
It has come to exist within. The outer periphery of the fermentation vessel 1 is covered with a jacket containing a heat transfer heater to control the temperature to be optimal for fermentation. In this embodiment, the alumina fiber wall 2 has been described as having a cylindrical shape, but a plate-like wall may be used as a vertical wall to partition the container, and it is also possible to partition the inside of the container into upper and lower sections. (Effects of the Invention) As detailed above, according to the method for producing fermented foods of the first invention of this application, the number of bacterial cells activated during the fermentation process is always high and can be maintained for a long time. Therefore, the efficiency of the fermentation reaction can be significantly improved, and the fermentation liquid can always be obtained efficiently and in a short time, so the present invention is extremely significant industrially. In addition, according to the fermented food manufacturing apparatus of the second invention of this application, there is no need to comprehensively immobilize bacterial cells on a carrier and make them into beads as in the past, and it is possible to completely sterilize the inside of the fermentation container. Since there is no invasion of bacteria, a high-quality fermented liquid can be obtained. Furthermore, since all the raw materials for this carrier are inorganic, there is no problem in terms of food safety. Furthermore, the alumina fiber wall can be used repeatedly by sintering it again, making it extremely economical. (Examples) Hereinafter, these inventions will be described in more detail with reference to Examples. Example 1 Add 9.6 kg of water to a mixture of 6 kg of defatted soybeans and 1.3 kg of wheat.
and put it in a 60 volume airtight container to make 1kg/
After heating with cm ² ·g of steam for 30 minutes, it was thoroughly loosened, further heat treated with 1 kg/cm ² ·g of steam for 45 minutes, and then cooled. On the other hand, 3 kg of Aspergillus oryzae on the epidermis.
Inoculate ATCC20386 and make koji at 30 to 35°C for 42 hours to obtain solid koji, extract the solid koji with 5 times the amount of cold water, pre-filter the obtained enzyme solution with a filter press,
In addition, SA-451 type sterile filter [Nippon Roshiki Kogyo Co., Ltd.]
A sterile enzyme solution was obtained. 9.6 of this sterile enzyme solution was added to the total amount of the above-mentioned cooled raw material, and enzymatically decomposed at 40° C. for 64 hours while shaking. After adding 2 kg of salt to the obtained hydrolyzate (salt concentration 9% w/v), it was squeezed to obtain enzymatically decomposed juice 20.1 kg.
was collected and adjusted to pH 6.0 with caustic soda, and added to the soy sauce lactic acid bacterium Bedeiococcus halophyllus IAM1693 in a lactic acid bacteria medium (dark raw soy sauce).
10% v/v, glucose 1% w/v, salt 8%
Add 100 lactic acid bacteria culture solution (number of viable cells 1.1 x 10 ⁸ /ml) that was cultured at 30°C for 4 days in w/v, sodium acetate 3.5% w/v, yeast extract 0.3% w/v, PH 7.0). (Number of viable lactic acid bacteria was 5.9×10 ⁵ /ml), and lactic acid fermentation was carried out at 30° C. for 120 hours under anaerobic conditions. Next, this lactic acid fermentation liquid was heated at 80°C for 20 minutes to stop lactic acid fermentation, and the produced lactic acid bacteria cells were filtered through diatomaceous earth in a conventional manner to obtain an enzymatically decomposed filtrate (liquid component value: TN2.05% w/v). , RS8.83%w/v,
NaCl 9.00% w/v, PH 5.06, TA 2.15) 19.4 was obtained. On the other hand, soy sauce yeast Satsukaromyces luxii No.
IFO1877 (saccharomyces rouxii) and Candida versatilus No.FRZ451 (Candida
versatilis) respectively in yeast culture liquid medium (koikuchi raw soy sauce 5-10% v/v, glucose, 5-7%
w/v, salt 0-8% w/v, monopotassium phosphate
0.1%w/v, magnesium sulfate 0.05%w/v,
Yeast extract 0.1-0.5% w/v, calcium chloride
0.01% w/v, polypeptone 0-0.5% w/v,
After shaking culture at 30℃ for 48 to 72 hours (PH5.0 to 5.5), each yeast cell obtained by centrifugation at 8000 x G for 10 minutes was washed once with sterilized water and then cultured again. After separating the cells by centrifugation, each yeast cell was added to the above-mentioned yeast culture liquid medium and mixed well.
It was made into a yeast suspension of Versatilus. Next, each of the yeast suspensions described above was absorbed into an immobilization carrier in the anaerobic fermentation apparatus shown in FIG. The anaerobic fermentation device consists of two devices connected in series, the first
The fermentation equipment has immobilized Saccharomyces luxii and is mainly used for ethanol fermentation, which is necessary for flavoring soy sauce. The second fermentation device is a fermentation device in which Candida versatilus, which produces the unique aroma of soy sauce such as 2-ethyl guaiacol, is immobilized.
The immobilization carrier material is alumina made by bonding alumina fibers mainly composed of aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) to form pores of 30 to 300 microns. Fiber walls are applied. In addition, the shape of the immobilization carrier includes cylindrical, cylindrical, plate-shaped,
It also includes those formed into granules and prepared for filling. Next, for the reaction, the lactic acid fermentation finished liquid is injected into the first fermentation device, that is, the carrier on which Saccharomyces luxii is immobilized. The reaction can be carried out either batchwise or continuously; in the former case, the lactic acid fermentation liquid is circulated through the carrier at a rate of 10 to 100 ml/hr using a pellicle pump to promote the reaction. Fermentation temperature is 20-30℃. In the batch method, the desired product solution can be obtained in 48 to 72 hours. After pasteurizing the product liquid, centrifugation is performed if necessary to obtain a supernatant liquid. The supernatant liquid is then transferred to a second fermenter. In other words,
As in the case of the first fermenter, in a batch method, the fermented liquid of the first fermenter is circulated using a peristaltic pump at a rate of 10 to 100 ml/hr on carriers on which Versatilus has been immobilized in advance. The reaction temperature is
The temperature is 25-30℃. Regarding the second fermentation, the desired product liquid can be obtained in 48 to 72 hours. The fermented liquid that has completed the second fermentation is subjected to pasteurization treatment in a conventional manner to produce a product. The continuous method is not much different from the batch method, but the first and second fermenters are connected in series and the lactic acid fermentation liquid is continuously injected into the first fermenter at a rate of 5 to 20 ml/hr using a peristaltic pump. After pasteurizing the resulting eluate, it is subsequently injected into the second fermentation device at a rate of 5 to 20 ml/hr using a peristaltic pump.
For elution, as in the case of the batch method, the product is made by pasteurization using the conventional method. In addition, when using the cell fusion yeast of Satucharomyces ruxii and Candida persacillus, the product can be obtained with a single first fermentation device. Example 2 A beer manufacturing method using the manufacturing method of the first invention of this application will be described. In this example, the carrier for adsorbing and immobilizing bacterial cells includes alumina fiber, which is the same as in the case of soy sauce production in Example 1, as well as silica, alumina, etc., singly or in combination, calcined with a binder such as colloidal silica, sulfuric acid band, etc. A porous support made of alumina fibers bonded together was also used. The immobilization carrier may have a cylindrical shape, a plate shape, etc., or a combination thereof. The beer production method in this example involves immobilizing brewer's yeast on this carrier, installing the immobilized brewer's yeast in a fermentation vessel, and then adding hops to the wort under anaerobic conditions either batchwise or continuously. The process consists of the following steps: injection, ethanol fermentation at low temperature through a yeast solidification layer, and beer production. The hop-added wort is prepared by a generally known method. for example,
After coarsely crushing 1 kg of germinated and dried barley with a crusher,
of water was added and saccharified at 70℃ for 4 hours, then boiled, cooled, and filtered with suction by adding celite to obtain clear liquid 3.
(sugar concentration 10%) was obtained. In the resulting wort, add 0.4
% of hops were added and boiled for 1 hour, then cooled and filtered to obtain hops-added wort. On the other hand, regarding the culture of yeast for immobilization, 5% glucose, 0.5% yeast extract, 0.5% polypeptone, 0.25%
% malto extract 500ml of culture solution adjusted to pH5.5
Add 100 ml to a shaking flask, and after sterilization, brewer's yeast or Satucharomyces calbergiasis
No.AHU3062 (Saccharomyces Carlsbergensis)
Add 500 ml of the same culture solution to the sterilized culture solution by shaking or static culture at 30℃ for 48 to 72 hours, add to the sterilized culture solution, and shake again at 30℃. Alternatively, after performing static culture, the yeast cells were separated by centrifugation, washed with sterilized water, and then added to the above-mentioned wort 1.5 to prepare a yeast suspension. The same suspension was circulated through the carrier at a rate of 20 ml for 1 minute using a peristaltic pump for 10 minutes.
Brewer's yeast was adsorbed onto the carrier over a period of time. Then,
After removing the circulating clarified liquid from the reactor, the hop-added wort was circulated with a peristal pump into a fermentation vessel equipped with a carrier, and beer fermentation was carried out under anaerobic conditions at a low temperature. Main fermentation using this fermentation container,
Post-fermentation was carried out in the same fermentation vessel, and beer with an ethanol concentration of over 5% was completed in about 15 days. Note that similar results were obtained even when only the main fermentation or post-fermentation was performed in the fermentation vessel. In addition to the alumina fibers used in the production of soy sauce, the carriers are alumina fibers with pores of 30 to 300 microns in pore diameter obtained by firing with silica and alumina as the main components, colloidal silica and sulfuric acid band system as binders. walls are used. As an example of the shape, a cylindrical carrier with an outer diameter of 75 mm, an inner diameter of 55 mm, and a height of 150 mm was attached to a cylindrical reactor with a diameter of 100 mm and a height of 250 mm. Others, horizontal 125
mm, length 125mm, thickness 35mm plate ceramic plate set in the center, width 130mm, height 130mm,
Similar results were obtained using a fermentation vessel shaped like a rectangular parallelepiped with a length of 250 mm. FIG. 4 shows the progress of beer components when beer was produced using the above-mentioned fermentation vessel. From FIG. 4, it can be seen that the progress of the beer components produced by this method is characterized by the same results as those obtained by conventional beer production in a short period of only 15 days. Figure 5 shows the progress of diacetyl and total aldehyde, which are disliked as bitter-odor components of beer. As a result, the same process as normal beer production was achieved in just 15 days, which is another major feature of this production method. Example 3 Next, a sake manufacturing method using the manufacturing method of the first invention of this application will be described. First, carrier preparation is important. In addition to the alumina fibers used in the production of soy sauce, the carriers used in this example were porous carriers made by firing silica and alumina alone or in combination with binders such as colloidal silica and sulfuric acid to bond the alumina fibers together. be. Regarding the shape, the immobilization carrier is either cylindrical or plate-shaped. The method for producing sake in this example includes immobilizing sake yeast on this carrier;
After installing this immobilized sake yeast in the fermentation container,
The process consists of injecting a fermentation stock solution under anaerobic conditions using a batch method or a continuous method, and then passing through a sake yeast immobilization layer to perform ethanol fermentation at low temperatures to produce sake. The saccharification liquid (fermentation stock solution) used in the present invention is a mixture of liquids saccharified with rice malt and a saccharifying enzyme. That is, the saccharified rice malt solution was obtained by adding 600 ml of water to 300 g of rice malt prepared using Aspergillus oryzae in a conventional manner and saccharifying the mixture at 50° C. for 12 hours, followed by centrifugation to obtain the saccharified solution. On the other hand, for the enzymatic saccharification solution, wash 700g of white rice, soak it in water, drain it, steam it for 40 minutes, add 1400ml of water,
0.7 g of saccharifying enzyme (Gluc-100) was added and the mixture was saccharified at 50°C for 24 hours, followed by centrifugation to obtain an enzyme saccharified solution. Each of the saccharified solutions thus obtained was prepared as a fermentation stock solution (sugar concentration 23%). On the other hand, regarding the preparation of sake yeast for immobilization, 5% glucose, 0.5% yeast extract,
0.5% polypeptone, 0.25% malt extract, PH5.5
After sterilizing 100ml of the culture medium in a 500ml shaking flask,
Add sake yeast (Saccharomyces cervisiae, No. 7, Saccharomyces cervisiae) and heat to 48°C at 30°C.
After culturing with shaking for an hour, yeast cells were separated by centrifugation. Pour 500 ml of the same medium as in the case of shaking culture of the obtained yeast cells into an Erlenmeyer flask, and incubate for 30
After 48 hours of static or shaking culture at ℃, yeast cells were collected by centrifugation, washed with sterile water,
After suspending the yeast in the fermentation stock solution of 1.5, for 1 hour.
It took 10 hours to immobilize on the ceramic carrier installed in the fermentation vessel using a peristaltic pump at a rate of 20 ml. Next, after removing the circulating fluid, the newly prepared fermentation stock solution is pumped into the peristaltic pump.
Ethanol fermentation was performed at low speed with circulation at a rate of 20-60 ml/hr or injection only. In the continuous method, the injection rate was lowered. As a carrier, in addition to the above-mentioned carriers, an effective alumina fiber with a pore size of 30 to 300 microns is obtained by baking a mixture of materials mainly composed of silica, alumina, etc., and using colloidal silica, sulfuric acid bandate, etc. as a binder. It's a wall. Regarding its shape, for example, a cylindrical carrier with an outer diameter of 75 mm, an inner diameter of 55 mm, and a height of 150 mm was attached to a cylindrical fermentation container with a diameter of 100 mm and a height of 250 mm. Others: width 125mm, height 125
mm, 35mm thick plate-shaped ceramics set in the center, or multiple ceramics set in width 130mm and length
A cuboid-shaped fermentation vessel measuring 130 mm and 250 mm in length was also used. The relationship between the decrease in sugar concentration, the production of ethanol, acidity, and formol nitrogen over time during the sake production conducted using the method described above is summarized as the initial sugar concentration.
The results of quantifying both 24% and 30% are shown in the sixth section.
7, 8 and 9. From the drawing, it can be seen that good results were obtained in a short period of time for both initial sugar concentrations of 24% and 30%. In other words, initial sugar concentration
For 24%, it took just 10 days, and for 30%, it took just 20 days. Next, Table 1 shows the results of quantifying the general components, organic acids, and aromatic components of the sake produced by this method. As shown in Table 1, there was no difference between the sake produced by this method and that by the conventional method.

[Table] Example 4 Next, the manufacturing apparatus of the second invention of this application will be explained in more detail using FIGS. 2 and 3. The fermentation vessel 1 is made of stainless steel and has an inner diameter of 90 mm, and an alumina fiber wall 2 of 30 to 300 microns is disposed in the center of the fermentation vessel 1. The dimensions of the alumina fiber wall 2 are an outer diameter of 75 mm, an inner diameter of 55 mm, and a length of 150 mm.
Industries) was used. First, 100 ml of glucose is placed in a 500 ml sugar shaking flask, one platinum loop of bacterial cells (Saccharomyces cerevisiae ellipsoideuse) is inoculated, and cultured with shaking for 24 to 48 hours. The thus-suspended bacterial cell suspension is injected into the inside of the alumina fiber wall 2 of the fermentation container 1, which has been completely sterilized in advance, using the pump 21. 2
The bacterial cells are adsorbed and immobilized. Next, (substrate 5% glucose solution) is injected into the injection chamber 15 inside the alumina fiber wall 2 using the pump 21. The substrate passes through the alumina fiber wall 2 and leaches into a collection chamber 16 outside the alumina fiber wall 2 and is discharged through the outlet 6.
When it gets close, valve 22 is closed and valve 23 is opened at the same time. This allows the substrate to be transferred to fermentation vessel 1.
circulate within. When the sugar concentration of the substrate becomes approximately zero, the valve 23 is closed, the valve 22 is opened, and the substrate is injected into the injection chamber 15. The liquid leached into the recovery chamber 16 is taken out from the outlet 6 to the receiver 24. FIG. 3 shows the results of measuring the state of alcohol fermentation by varying the amount of substrate injected. After 4 hours of initial circulation in the fermentation vessel, the sugar concentration of the substrate becomes zero and the alcohol concentration is approximately 2%.
It became. Adjust the substrate injection volume to 55ml/hr, 80ml/hr, or 100ml/hr.
hr, I tried changing it to 120ml/hr, but as you can see from the figure, complete alcoholic fermentation was achieved even at 100ml/hr. It can also be seen that the substrate injection rate is too high in the case of 120ml/hr. Note that after that, leave the liquid in the fermentation container as it is.
After leaving it for about 10 days, I tried supplying the substrate again, but the bacteria were sufficiently viable and fermentation started immediately.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing an embodiment of the fermented food manufacturing apparatus of the present invention, Figure 2 is a schematic diagram showing an experimental example using the apparatus shown in Figure 1, and Figure 3 is a diagram showing varying the amount of substrate supplied. Figure 4 is a graph showing the progress of beer components over time, and Figure 5 is a graph showing the progress of total aldehyde and diacetyl components over time. Graphs 6 to 9 are graphs showing the relationship between components and time in the immobilized sake yeast reactor, and Figure 6 shows the relationship between acidity and formol nitrogen at an initial fermentation concentration of 24% and the passage of time. Figure 7 is a graph showing the relationship between sugar concentration and ethanol over time at an initial fermentation concentration of 24%, and Figure 8 is a graph showing the relationship between acidity and formol nitrogen over time at an initial fermentation concentration of 30%. The graph shown in FIG. 9 is a graph showing the relationship between sugar concentration and ethanol over time at an initial fermentation concentration of 30%. Explanation of symbols, 1...Fermentation vessel, 2...Alumina fiber wall, 3...Draft tube, 4...Rotary vane, 5...Supply port, 6...Discharge port, 12...
Steam intake.

Claims (1)

[Claims] 1. An alumina fiber made by bonding alumina fibers mainly composed of aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) to form pores of 30 to 300 microns. After the bacterial cell suspension is absorbed into the wall and the bacterial cells are adsorbed and immobilized within the pores of the alumina fiber wall, the substrate is passed through the pores of the alumina fiber wall under anaerobic conditions. A method for producing a fermented food, characterized in that it is brought into contact with the body and fermented. 2. The method for producing a fermented food according to claim 1, wherein the fermentation time under anaerobic conditions is 20 to 120 hours. 3 Alumina fibers containing aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) as main components that have absorbed a bacterial cell suspension, which are installed so as to separate the inside of a sealed fermentation container, are An alumina fiber wall bonded to form ~300 micron pores, an injection chamber formed within the fermentation vessel by the alumina fiber wall into which the substrate is injected, and an injection chamber formed within the fermentation vessel by the alumina fiber wall. An apparatus for producing a fermented food, comprising a recovery chamber in which a substrate passes through the holes in the alumina fiber wall under anaerobic conditions and recovers a fermented liquid.