JP2014079264A - Method for stopping fermentation of fermented food product by non-heat sterilization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stopping the fermentation of a fermented food product made using a low pressure-resistant yeast which can be easily sterilized by pressure treatment with a pressure value without impairing the advantage of non-heat sterilization.SOLUTION: A fermented food product is made by fermentation of food material using a low pressure-resistant yeast obtained by screening of wild yeast strain of saccharomyces or mutated yeast strain of saccharomyces with verification that the yeast can be easily sterilized by pressure treatment without heating under a hydrostatic pressure of 1 MPa or more and 200 MPa or less. A method for stopping the fermentation of a fermented food product includes sterilizing the low pressure-resistant yeast of the fermented food product by pressure treatment without heating under a hydrostatic pressure of 1 MPa or more and 200 MPa or less so as to stop the fermentation.

Description

  The present invention relates to a method for stopping fermentation by non-heat sterilization of fermented foods produced using low-pressure yeast that can be sterilized by pressure treatment at a pressure value that does not impair the advantages of non-heat sterilization.

  Fermented and brewed foods such as miso, soy sauce, and liquor are all manufactured using the fermenting action of yeast.

  In addition, these fermented and brewed foods are usually subjected to yeast separation and sterilization by filtration or heat treatment to prevent overfermentation after a certain period of fermentation and aging.

  For example, miso is heated at 50 to 70 ° C. for 60 minutes, and soy sauce is heated at 70 to 85 ° C. for 10 to 30 minutes. In addition, the sake that has been pulled and filtered with sake is heat-treated at 60 to 70 ° C. for 10 minutes to sterilize and deactivate the enzyme.

  However, such conventional separation / sterilization methods may change the flavor and color of food due to heat treatment, and require time-consuming cooling, such as quick cooling after heat treatment. Met.

  More uniform heat treatment is necessary, and if this heat treatment is insufficient, the product value is lost due to over-fermentation by remaining yeast and swelling of the packed product due to the generation of carbon dioxide gas. There is also a problem.

  Therefore, in order to solve such a problem, conventionally, as in JP-A-7-213277 (Patent Document 1), a method for suppressing fermentation in a low-temperature range of 0 to 15 ° C. after fermentation and ripening, As described in JP-A-73063 (Patent Document 2), a method for producing fermented foods using a combination of low-temperature sensitive yeast and lactic acid bacteria has been proposed.

  However, since yeast is not sterilized by these methods, temperature control after fermentation is newly required.

JP-A-7-213277 JP 2004-73063 A

  In fermented (brewed) foods, there is a demand for a method that can sterilize yeast without altering useful components of foods after fermentation and ripening, and without losing color.

  The applicant has so far conducted various studies and experiments on foods under the theme of pressure treatment (also referred to as high pressure treatment), and thought that the above problems could be solved by this pressure treatment.

  This pressure treatment is a technology that processes and sterilizes food by applying a pressure of about 100 MPa or more, and has traditionally been used to produce fermented foods such as miso and soy sauce in addition to jam, cooked rice, noodle soup, and processed brown rice. There is a track record of being used.

  In addition, this pressure treatment, which is a non-heat sterilization technique, can selectively sterilize only yeast without altering useful components of food. Furthermore, generally, 300 MPa, It has also been found that pressure treatment for 10 minutes or more may be performed.

  Therefore, the applicant has paid attention to this pressure treatment that yeast can be sterilized without deteriorating useful components of food after fermentation and ripening, and without losing color.

  However, when the experiment was repeated, even if pressure treatment was performed at 300 MPa for 10 minutes, there was a possibility of survival depending on the yeast, which was not a reliable result.

  If a pressure of 300 MPa or more is applied, a higher sterilization effect can be obtained, but the processing equipment becomes larger and more expensive, resulting in a higher processing cost. Therefore, a change in hue occurs, and the advantage as non-heat sterilization cannot be utilized. In addition, if the pressure value is too high, in the parallel complex fermented food of yeast and lactic acid bacteria represented by kefir yogurt, not only yeast but also useful lactic acid bacteria may be killed after fermentation.

  In light of the current situation, the applicant has been researching whether there is a method that can sterilize yeast without causing alteration or color change of food by using pressure treatment, which is a non-heat sterilization technique. The idea was changed, and if fermented foods were produced in advance using yeast having low resistance to pressure, it was noted that yeast could be reliably sterilized by subsequent pressure treatment.

  That is, the present invention provides a method for stopping fermentation by non-heat sterilization of fermented foods produced using a low pressure resistant yeast that can be easily sterilized by pressure treatment at a pressure value that does not impair the advantages of non-heat sterilization. With the goal.

  The gist of the present invention will be described with reference to the accompanying drawings.

  Ingredients using low-pressure-resistant yeast that was screened from wild yeast strains of Saccharomyces spp. Or yeast strains of Saccharomyces spp. Fermented food obtained by subjecting the fermented food obtained by fermenting the fermented food to non-heating pressure treatment at a hydrostatic pressure of 1 MPa to 200 MPa to sterilize the low pressure-resistant yeast of the fermented food and stop the fermentation. This relates to a method for stopping fermentation by non-heat sterilization.

  Since the present invention has been described above, when stopping fermentation of fermented foods, it is possible to perform non-heat sterilization by non-heating pressure treatment with a hydrostatic pressure of 1 MPa to 200 MPa which does not require a large and expensive pressure treatment facility. It is possible to easily sterilize fermented food yeast by stopping the fermentation of the fermented food by pressure treatment at a pressure value that does not impair the advantages, and the pressure treatment may change the useful components or damage the color. It becomes a fermentation stopping method by non-heat sterilization of an innovative fermented food excellent in practicality that can stop fermentation of fermented food without any problems.

It is the graph which verified the pressure resistance in each pressure conditions of the low pressure resistant yeast screened by the method shown in the specific example 1, and an untreated yeast. It is a comparative microscope picture which shows the low pressure-resistant yeast (yeast with a large average particle shape) screened with the method shown in the specific example 2, and a yeast with a small average particle shape. It is the graph which verified the pressure resistance in each pressure conditions of the low pressure resistant yeast screened by the method shown in the specific example 2, and an untreated yeast. It is the graph which verified the pressure resistance in each pressure conditions of the low pressure resistant yeast screened by the method shown in the specific example 3, and an untreated yeast. It is the graph which verified the pressure resistance in each pressure conditions of the low pressure resistant yeast screened by the method shown in the specific example 4, and an untreated yeast. It is the graph which verified the pressure resistance in each pressure conditions of the low pressure resistant yeast screened with the method shown in the specific example 5, and an untreated yeast.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  It was confirmed that the fermented food used in the present invention was sterilized by non-heating pressure treatment at a hydrostatic pressure of 1 MPa or more and 200 MPa or less screened from a wild yeast strain of the genus Saccharomyces or a yeast strain of the genus Saccharomyces subjected to mutation treatment. It is a fermented food made by fermenting ingredients using low-pressure yeast.

  For example, using this low-pressure resistant yeast, various fermented foods such as sake, beer, wine, bread, soy sauce, and miso can be produced by fermenting food materials according to a conventional method.

  In addition, the "fermented food" as used in the field of this invention is used in the meaning including the brewed food manufactured using the fermenting action by yeast.

  In the present invention, the fermented food obtained by fermenting food using this low pressure-resistant yeast is subjected to a non-heated pressure of hydrostatic pressure of 1 MPa or more and 200 MPa or less after a certain fermentation / ripening period. The low-pressure yeast used for fermentation of this fermented food is sterilized by processing, and fermentation of this fermented food is stopped.

  Such hydrostatic pressure treatment at a pressure value of 1 MPa or more and 200 MPa or less can be carried out without any problems with existing pressure treatment equipment, so no additional equipment investment is required, and the quality of food is altered or changed. And so on.

  That is, according to the present invention, yeast (low pressure-resistant yeast) of fermented food can be sterilized without damaging useful components and colors without requiring new large and expensive equipment, and fermentation of fermented food is stopped. be able to.

  Hereinafter, the specific example of the screening method of the low pressure resistant yeast used for fermentation of the fermented food used for this invention is demonstrated.

[Specific Example 1]
Specific example 1 is a low-pressure-resistant yeast characterized by screening a yeast capable of growing in a low temperature range of 20 ° C. or lower for a wild yeast strain of Saccharomyces or a yeast strain of Saccharomyces that has been subjected to mutation treatment. Screening method.

  Specifically, for example, by culturing a wild yeast strain of the genus Saccharomyces or a yeast strain of the genus Saccharomyces that has been subjected to a mutation treatment in a low temperature range from 0 ° C. to 20 ° C., by changing the temperature stepwise. Yeast that can grow in this low temperature range is screened.

  More specifically, for example, the number of colonies formed on a plate such as a YPD agar medium when a Saccharomyces wild strain (a strain not subjected to mutation treatment) or a mutant Saccharomyces yeast strain subjected to a mutation treatment is used. Inoculate so that there are about 200.

  The plate is cultured at 0 ° C. for about 7 days to confirm colony formation (proliferative quality). If there is a colony that is favorably formed at 0 ° C., the colony is caught with a platinum loop or the like and cultured again as a candidate for a low pressure resistant yeast.

  If colony formation is not observed at 0 ° C, or if there is no significant difference in the viability of each colony, increase the culture temperature by about 2 ° C and repeat the culture for about 7 days to confirm the formation of colonies. To do.

  In the case of culturing at 2 ° C., if a colony is formed well, the colony is picked and cultured as a candidate for a low pressure resistant yeast.

  In the same manner, the presence or absence of colonies was confirmed after culturing for about 3 to 7 days in an appropriately selected low temperature range from about 0 ° C. to about 20 ° C. If the colony formation is not observed, or if there is no significant difference in the growth ability of each colony, repeat the procedure of increasing the culture temperature step by step, and grow well at low temperature Select the colonies that are

  It has been confirmed by the applicant's experiment that the yeast thus selected is sterilized by applying non-heating pressure treatment at a hydrostatic pressure of 1 MPa to 200 MPa. That is, it is found that the optimum temperature for culturing yeast is around 30 ° C., whereas the low pressure resistant yeast has a characteristic that it grows well in a low temperature range of about 0 ° C. to 20 ° C. Using this property, we succeeded in screening low-pressure-resistant strains.

  This will be described in more detail below.

  As a target strain for screening, for example, a yeast strain belonging to Saccharomyces cerevisiae, which has not been subjected to mutation treatment, or a mutant treatment strain can be used. Mutation treatment is carried out by some method such as X-ray, UV irradiation, ethylmethanesulfonic acid (EMS), nitrosoguanidine (NTG) treatment. Usually, the treatment is performed so that the survival rate after the mutation treatment is 10% or less. If the survival rate is further reduced, an extra mutation occurs, which is not preferable. Although the diploid yeast may be used for the mutation treatment, it is more efficient to use a haploid spore strain.

  Moreover, as a culture medium to be used, the normal culture medium which contains a carbon source, a nitrogen source, an inorganic ion, and also an organic trace nutrient as needed can be used. For example, YPD agar medium (yeast extract, glucose, polypeptone, agar, distilled water), YM agar medium (yeast extract, malt extract, peptone, glucose, agar, distilled water, pH 5-6), etc. are used (in liquid medium) Except agar). As a culture method, for example, it is cultured at 30 ° C. for 3 days, collected by centrifugation (3000 rpm, 10 minutes), washed twice with physiological saline, and suspended in physiological saline to obtain an appropriate bacterial concentration. It becomes cloudy.

  The culture may be performed under general conditions, and the culture temperature is generally 20 to 30 ° C., preferably around 30 ° C., and the culture days are 1 to 7 days, preferably about 3 days.

When mutation treatment is performed, this suspension is treated with a mutation agent such as UV, NTG, EMS or the like so that the survival rate is about 10% or less. After centrifugation, the number of viable bacteria is about 4 ×. Suspend in a liquid medium to about 10 ⁷ and culture with shaking at 30 ° C. for 12 hours.

  In addition, the above point is the same also in the specific examples 2-5 mentioned later.

  A wild strain of Saccharomyces cerevisiae NBRC1136 (distributed strain of Biotechnology Research Institute) was initially cultured in a YM medium at 30 ° C. for 3 days.

  The cells were collected by centrifugation at 3000 rpm for 3 minutes, and then washed by adding 5 ml of sterilized water.

  This washing operation was repeated twice and then suspended in physiological saline so as to obtain an appropriate concentration.

  After the suspension was diluted, it was inoculated so that the number of colonies formed on the plate was about 200.

  Cultivation was performed at 0 ° C. for about 3 to 7 days, and the presence or absence of colony formation was confirmed every day.

  When colony formation was not observed, the cells were cultured in a low temperature range up to 20 ° C. while gradually increasing the temperature by 2 ° C. to form colonies capable of growing in the low temperature range.

  As a result, colonies of a degree that can be visually confirmed at 10 ° C. for 5 to 7 days are formed. Among them, a plurality (about 10 to 20) of particularly good growth are collected with platinum ears. Then, the culture was again carried out in YM medium at 30 ° C. for 3 days, and this was obtained as a low pressure-resistant strain.

  Thereafter, the obtained low pressure resistant strain was subjected to a pressure treatment of 200 MPa to evaluate the pressure resistance.

  FIG. 1 is a graph showing the pressure resistance of each of the yeast screened in Example 1 and the untreated yeast under pressure conditions.

  From this result, it was confirmed that untreated yeast requires a pressure treatment of about 300 MPa for sterilization, but the yeast screened in Example 1 can be sterilized by a pressure treatment of about 200 MPa.

  In addition, the pressure process here means the hydrostatic pressure process which used liquids, such as water, as a medium, and all the pressure processes of the specific examples 2-5 described below also mean this.

[Specific Example 2]
Specific Example 2 is a yeast having a vegetative cell size larger than the average size of the vegetative cells possessed by each yeast in the strain of a Saccharomyces genus wild yeast strain or a mutant Saccharomyces genus yeast strain. Is a screening method for low pressure-resistant yeast, characterized by screening.

  Specifically, for example, a wild yeast strain of Saccharomyces sp. Or a yeast strain of Saccharomyces sp. That has been subjected to mutation treatment is cultured and collected, and then suspended in physiological saline. A yeast having a large morphological size (a yeast having a large size of vegetative cells has a large morphological size) is screened by a separation method, density gradient centrifugation, or L-triator rotor separation.

  More specifically, for example, a wild yeast strain of Saccharomyces sp. Or a yeast strain of Saccharomyces sp. That has been subjected to mutation treatment is cultured, collected and washed, and then suspended in physiological saline so as to obtain an appropriate bacterial concentration. To do.

The bacterial concentration of the suspension is preferably about 10 ³ to 10 ⁴ / ml. In order to dissociate the aggregates of the bacterial cells, the suspension is subjected to an ultrasonic device for about 15 to 30 seconds under low output conditions. Good.

  From the suspension thus prepared, for example, yeast having a large morphological size is selected by a method such as natural sedimentation, centrifugation, density gradient centrifugation, or L-triator rotor.

  For example, as a natural sedimentation method, a bacterial solution is suspended in a sucrose solution or the like adjusted to an appropriate concentration and allowed to stand for a certain period of time to precipitate a cell having a high cell density. In microorganisms such as yeast, cells having larger vegetative cells generally have a higher cell density, and cells having a lower cell density have a smaller size.

  Therefore, it is possible to isolate yeast having a large size of vegetative cells by collecting the precipitate after standing for a certain period of time.

  In the density gradient centrifugation method, for example, a high-density liquid such as a 60% sucrose solution is placed at the bottom of the centrifuge tube, and a low-density liquid such as 15% sucrose is placed at the top, and the density is changed sequentially between them. Adjust to.

  As another method for creating a density gradient, there is a method in which a density gradient is naturally generated by centrifugal force when a strong centrifugation is performed like a cesium chloride solution.

  Gently overlay the appropriately diluted bacterial solution on the upper part of the density gradient solution formed by such a method, leave it for a certain period of time, and centrifuge it, and the yeast will have a density according to the density of each solution layer. Can be separated.

  In addition, the L triator rotor can be separated as each fraction according to various sizes according to the centrifugal force and the flow rate of flowing the suspension.

  Saccharomyces cerevisiae haploid cells, which are the budding yeast, have an oval shape with a major axis of about 5 μm, and the diploid cells are slightly larger than that and have a lemon shape with both ends slightly cut off. ing.

  When separating yeast according to the size of the vegetative cell by the method as described above, it is necessary to observe the size and form of the yeast mixed with an optical microscope, a micrometer, etc., preferably flow cytometry. It is desirable to measure the particle size distribution of the yeast in the suspension by a method or the like.

  The separation and fractionation of yeast is preferably in the range of about 1 μm. However, since it depends on the method and the device used, an appropriate method and device are used based on the confirmed yeast size and form in the suspension. Will be selected.

  Although there is no particular standard for the size of yeast to be selected, selection is generally made for a range of 10% or less from the larger size of the particle size distribution of the overall cell size.

  It has been confirmed by the applicant's experiment that the yeast thus selected is sterilized by non-heating pressure treatment at a hydrostatic pressure of 1 MPa to 200 MPa. That is, the low-pressure-resistant yeast has the characteristic that the size of the vegetative cells is larger than the average size of the vegetative cells of each yeast in the strain. Succeeded in screening.

  This will be described in more detail below.

The suspension prepared in the same manner as in Example 1 is an L-triator separation system consisting of CR22GII type high-speed cooling centrifuge (manufactured by Hitachi Koki Co., Ltd.) and R5E type L-triator rotor (manufactured by Hitachi Koki Co., Ltd.). Thus, fractionation was performed for each fraction depending on the size of vegetative cells, and yeast (low pressure resistant strain) was obtained in which the size of vegetative cells was larger than the average size of vegetative cells present in the strain ( (See FIG. 2). The processing conditions are a temperature of 4 ° C., a rotational speed of 3000 rpm, and a flow rate of 9 ml / min to 23 ml / min (see Table 1).

  FIG. 3 is a graph showing the pressure resistance of each of the yeast screened in Example 2 and untreated yeast under pressure conditions.

  From this result, it was confirmed that untreated yeast requires a pressure treatment of about 300 MPa for sterilization, but the yeast screened in Example 2 can be sterilized by a pressure treatment of about 200 MPa.

[Specific Example 3]
Specific Example 3 is a Saccharomyces genus yeast strain or a Saccharomyces genus yeast strain that has been subjected to a mutation treatment, yeast that is difficult to grow (grow) under low humidity conditions of 20% or less of humidity, or humidity of 80% or more. A method for screening low-pressure-resistant yeast, characterized by screening yeast capable of growing (growing) under high humidity conditions.

  Specifically, for example, a wild yeast strain of Saccharomyces or a yeast strain of Saccharomyces that has been subjected to a mutation treatment is cultured under a low humidity condition with a humidity of 20% or less and is difficult to grow under this low humidity condition. A yeast strain of Saccharomyces sp. Or a Saccharomyces spp. Yeast strain that has been screened or mutated can be cultured under high-humidity conditions with a humidity of 80% or more and can be grown under these high-humidity conditions. Screen for yeast.

  More specifically, for example, a Saccharomyces genus wild yeast strain or a mutant Saccharomyces genus yeast strain is inoculated so that the number of colonies formed on a plate such as a YPD medium is about 200.

  The plate is cultured for about 3 to 7 days under a suitable temperature such as 30 ° C. and a low humidity condition of 10% or less, and the strain has poor growth and poor growth, that is, a small colony is formed. To select.

  Alternatively, a strain that grows and grows well under a high humidity condition of 30 ° C. and a humidity of 90% or more, that is, a large colony formed is selected.

  By this method, it is possible to select yeasts that are difficult to grow under low humidity conditions, yeasts that grow well under high humidity conditions, that is, yeasts that have low resistance to drying.

  It has been confirmed by the applicant's experiment that the yeast thus selected is sterilized by non-heating pressure treatment at a hydrostatic pressure of 1 MPa to 200 MPa. That is, low pressure-resistant yeast is particularly difficult to grow under low humidity conditions with a humidity of 20% or less, and has good growth under high humidity conditions with a humidity of 80% or more. We found that it has the characteristic that resistance is weak, and succeeded in screening a low-pressure-resistant strain using this characteristic.

  This will be described in more detail below.

  The plate is inoculated so that the number of colonies forming the bacterial solution prepared in the same manner as in Example 1 is about 200. Cultivation was started at 30 ° C. and a humidity of 90%, and colony formation was confirmed over time.

  The formation of colonies can be confirmed visually by culturing for about 3 to 7 days. Among them, about 10 to 20 samples having particularly good growth are collected with platinum ears, and again in YM medium. Culturing was carried out at 3 ° C. for 3 days, and this was obtained as a low pressure-resistant strain.

  Thereafter, the bacterial solution containing the obtained low-pressure-resistant strain was subjected to pressure treatment up to 200 MPa, and pressure resistance was evaluated.

  FIG. 4 is a graph in which the pressure resistance of the yeast screened in specific example 3 and the untreated yeast under each pressure condition is verified.

  From this result, it was confirmed that the untreated yeast requires a pressure treatment of about 300 MPa for sterilization, but the yeast screened in Example 3 can be sterilized by a pressure treatment of about 200 MPa.

[Specific Example 4]
For the suspension prepared in the same manner as in Example 1, in order to break up aggregates and separate mature budding daughter cells from their mother cells, the diluted solution of the bacteria is gently sonicated (low 10 to 15 seconds at output), then transferred to a sterile petri dish and irradiated with ultraviolet light.

  For ultraviolet irradiation, 5 ml was collected in a sterilized petri dish and subjected to a germicidal lamp with an output of 15 W from a distance of 5 cm. As the germicidal lamp, a GL-15 germicidal lamp manufactured by Matsushita Electric Works was used.

  The treated bacterial solution was inoculated after serial dilution in YM agar medium and cultured at 30 ° C. for 3 days.

  A replica was prepared using the plate on which the colony was formed as a master plate.

  The replicated plate medium was aseptically sealed in a pouch and heat sealed while discharging air as much as possible.

  After the sealed flat plate medium was pressure treated at 200 MPa, it was opened aseptically, transferred again to a sterile petri dish, and cultured at 30 ° C. for about 3 days to form colonies.

  Compared with the untreated section, the one in which no colony was formed was obtained as a low pressure resistant yeast.

In Example 4, the number of viable bacteria after ultraviolet irradiation is 2.3 × 10 ² (6.3 × 10 ⁶ before treatment), and the sterilization rate by ultraviolet irradiation is 99.9%.

  In addition, 100 colonies formed after ultraviolet irradiation were replicated, and 2 colonies that died by pressure treatment of 200 MPa were obtained.

  In addition, two colonies obtained were proliferated, and 0 were killed by pressure treatment of 100 MPa.

  FIG. 5 is a graph in which the pressure resistance of each of the yeast screened in Example 4 and the untreated yeast under pressure conditions is verified.

  From this result, it was confirmed that the untreated yeast requires a pressure treatment of about 300 MPa for sterilization, but the yeast screened in Example 4 can be sterilized by a pressure treatment of about 200 MPa.

[Specific Example 5]
Specific Example 5 is a low-pressure-resistant yeast screening method characterized in that yeast is screened in combination with any two or more low-pressure-resistant yeast screening methods of Specific Examples 1-4.

  When yeast is screened by using any two or more of the low-pressure-resistant yeast screening methods described above, the low-pressure-resistant yeast can be screened more accurately and effectively.

  The number and order of these screening methods used are not particularly limited. Further, it is not necessary to perform the selected two or more screening methods in order, and for example, the two methods can be performed simultaneously.

  Specifically, the specific example 5 is a case where the specific example 1 and the specific example 4 are combined.

  The plate is inoculated so that the number of colonies forming the bacterial solution prepared in the same manner as in Example 1 is about 200.

  Cultivation was carried out at 10 ° C. for about 7 days, and about 300 colonies with particularly good growth among the formed colonies were collected and transferred to a plate to obtain a master plate.

  A replica was prepared from the master plate and subjected to pressure treatment in the same manner as in Example 4 to obtain a low pressure-resistant yeast.

  In Example 5, about 300 colonies were isolated by the method of Example 1 as a primary screening for low-pressure yeast.

  Thereafter, four low-pressure-resistant yeasts were obtained by the method of Example 4 as secondary screening.

  Compared with the screening method of Specific Example 1 or Specific Example 4 alone, low-pressure yeast could be screened with high probability.

  FIG. 6 is a graph in which the pressure resistance of the yeast screened in Example 5 and the untreated yeast under each pressure condition is verified.

  From this result, it was confirmed that untreated yeast requires a pressure treatment of about 300 MPa for sterilization, but the yeast screened in Example 5 can be sterilized by a pressure treatment of about 200 MPa.

  Specific embodiments of the present invention will be described with reference to the drawings.

  A present Example is the fermentation stop method by the non-heat sterilization of the fermented food using the low pressure resistant yeast.

  Specifically, for example, fermented food fermented using low-pressure-resistant yeast obtained by any one of the screening methods of Specific Examples 1 to 5 described above is used.

  For example, as fermented foods obtained by fermenting ingredients according to a conventional method using this low pressure resistant yeast, there are various fermented foods such as sake, beer, wine, bread, soy sauce and miso.

  In this example, the low-pressure-resistant yeast used for fermentation of this fermented food by performing non-heating pressure treatment with a hydrostatic pressure of 1 MPa to 200 MPa after the fermented food has passed a certain fermentation / ripening period. Is sterilized to stop fermentation.

  Such pressure treatment at a pressure value of 1 MPa or more and 200 MPa or less can be carried out without problems with existing pressure treatment equipment, so there is no need for additional equipment investment, and there is also a change in food quality and color. Absent.

  Therefore, the fermentation of the fermented food can be stopped without deteriorating useful components and without impairing the hue without requiring a new large and expensive facility.

  Note that the present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate.

Claims (1)

  Ingredients using low-pressure-resistant yeast that was screened from wild yeast strains of Saccharomyces spp. Or yeast strains of Saccharomyces spp. Fermented food obtained by subjecting the fermented food obtained by fermenting the fermented food to non-heating pressure treatment at a hydrostatic pressure of 1 MPa to 200 MPa to sterilize the low pressure-resistant yeast of the fermented food and stop the fermentation. Fermentation stop method by non-heat sterilization.