JPH08332084A - New yeast and production of breads by utilizing the same yeast - Google Patents

Abstract

PURPOSE: To obtain a new yeast, hating the abilities to resist the freezing and suppress low-temperature fermentation, useful as a dough, etc., for producing breads freezable or preservable by refrigeration and capable of saving the labor in baking, rationalizing the baking and diversifying the kind of bread products. CONSTITUTION: A yeast strain, having the freezing resistance and providing a parent strain is inoculated from a slant of the yeast strain into a culture medium by one platinum loop, cultured at 30 deg.C for 24hr by shaking culture and then centrifuged to collect the fungal cell, which is washed with a 0.1M phosphoric acid buffer solution (pH7.0). The yeast fungal cell is then suspended in the same phosphoric acid buffer solution and ethyl methansulfonate as a mutation inducer is added thereto. The mutation treatment is carried out at 30 deg.C for 60min and the resultant suspension is centrifuged to collect the fungal cell, which is then washed and smeared on an agar plate. A colony in which the growth is more suppressed than that of the parent strain is selected as a low-temperature sensitive yeast at 10 deg.C to afford five species of new yeasts of P-626 (FERM P-14962) to P-630 (FERM P-14966) of Saccharomyces cerevisiae strains having the abilities to resist the freezing and suppress the low-temperature fermentation and further stabilized proofing fermentation times.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel yeast and a method for producing breads using the yeast. More specifically, the present invention relates to a novel yeast useful for frozen dough and refrigerated dough in all types of breads, bread dough containing the yeast, and a method for producing breads using the yeast.

[0002]

2. Description of the Related Art In recent years, in the bread making industry, studies have been made on a bread making method for the purpose of streamlining the bread making process and labor management by saving labor. On the other hand, in order to meet the diversification of consumer needs, to provide fresh bread in a more delicious state, and to achieve the variety of bread product varieties desired by consumers, the frozen dough baking method and As bread-making methods for refrigerated dough have been studied, these bread-making methods have become popular.

[0003] Conventional yeasts for frozen dough have a very high freezing resistance, and even after long-term frozen storage, it has become possible to produce fresh bread with the same quality as before freezing and stable quality. The temperature rise due to poor storage conditions of the dough causes the frozen dough to partially thaw, the yeast activity in the dough is restored, the dough expands, and the bread quality of the final product is significantly reduced. Therefore, the temperature control of the freezer during storage or distribution of bread dough must be very strict, and a huge amount of energy is required to maintain a constant temperature.
Also, once thawed at the time of use, the yeast activity has been restored, so if the remaining bread dough is frozen or refrigerated again and reused, blisters will occur on the surface of the bread and the bread will be boiled. The actual situation is that it has a problem that the quality of the product deteriorates significantly.

In connection with such a problem, Japanese Patent Laid-Open No. 6-2
45687 discloses baker's yeast derived from freezing-resistant yeast and having low temperature sensitivity, but low sugar dough (5-6
%), And the fermentative power after re-freezing after thawing (heating) is about 60% before freezing, which is practical for frozen dough of all types. There is a problem in terms of sex.

In the pastry production, a retard method in which the dough is preliminarily processed at a low temperature is adopted in order to fold the roll-in fat in layers. When ordinary baker's yeast is used, fermentation does not stop even at low temperature, the dough expands, roll-in fats and oils are not folded neatly, and the bread layer is often not clean. The reality is that the temperature is lowered to around 0 ° C. where it is easy to stop and low temperature treatment is performed.

In order to solve such a problem, Japanese Unexamined Patent Publication No.
76348, JP-A-5-284896, JP-A-5-33.
6872, JP-A-7-79767, and JP-A-7-50.
006 discloses a yeast that is not fermented at low temperature such as refrigeration, or fermentation is stopped and fermented at a certain temperature or higher, so-called low temperature sensitive yeast, but in any case, fermentation can be rapidly stopped at low temperature. This is a feature, and at the time of low-temperature treatment during roll-in fat / oil folding, fermentation is stopped, the dough does not expand, and a problem of forming a clean fat / oil layer has been solved. However, in the chilled dough making method,
When yeast that has the property of stopping fermentation at low temperatures is used, unless the dough is left unattended until the dough temperature rises to a certain extent, the amount of dough expansion is insufficient compared to when using normal baker's yeast. However, I can't make good quality bread with a lot of volume. Further, when fermentation is completely stopped at a low temperature, maturing of the dough by fermentation metabolites of yeast is also stopped, and there remains a problem that bread with good flavor and texture cannot be produced.

[0007]

The bread making method for refrigerated dough is a method for producing bread by immediately or after fermenting the kneaded dough and then refrigerating and storing it, followed by fermentation and / or heat treatment. In the bread dough of normal baker's yeast, the temperature range in which it is actively fermented is 25 to 35 ° C, and in the dough exposed to a refrigerating temperature of about 5 ° C, the fermentation transitions from an active state to a weak fermentation state. Go. Therefore, when the refrigeration period is long, the fermentation proceeds even in the refrigerated bread dough, and the dough becomes in an excessively fermented state, resulting in deterioration of the quality of the final bread product. In order to solve this, a method of lowering the refrigerating temperature to a temperature at which the bread dough does not freeze is also used, but there is a problem that the energy cost related to refrigerating rises.

[0008] On the other hand, although baker's yeast has been improved and various refrigerating yeasts having low temperature sensitivity are commercially available, the major feature is that fermentation at low temperature is completely stopped. Although the problems seen with the ordinary baker's yeast described in (1) have been largely solved, the fermentation has stopped too much, and the fermentation cannot be recovered unless the dough that has been refrigerated and stored is returned to the normal temperature range. Not compatible with the baking process. Alternatively, the fermentation actually stops too much, and the dough becomes unripe when it is stored in a refrigerator, which deteriorates the quality of bread.

Further, in the frozen dough baking method, there is a problem that the yeast is killed or the activity is lowered depending on the period during the frozen storage of the dough, but by using the commercially available yeast for frozen dough, It has become possible to solve some problems. However, this does not apply when the bread dough is stored in a frozen state, when it is distributed, and when the temperature control of the dough thawing is insufficient. That is,
Inappropriate temperature control, the dough temperature rises and partially thaws, or the yeast activation due to the temperature rise during dough thaw causes the yeast in the dough to die, the fermentation power and the dough expansion power to decrease,
The gas retaining capacity is reduced due to the cell contents leaked from the dead yeast, which causes deterioration of the internal phase and appearance of the final bread product, or deterioration of flavor and texture.

The present invention provides a yeast for producing low-cost and stable-quality bread that does not adversely affect bread dough by freezing and / or refrigeration without changing the conventional dough mixing and baking process. To do. That is, it has a strong freezing resistance capable of storing frozen dough for a long period of time, and although fermentation at low temperatures is suppressed as compared with ordinary baker's yeast, it does not stop, and further refrigerated dough manufacturing method and normal The object of the present invention is also to provide a yeast having a so-called low-temperature fermentation suppressing ability at low temperature that does not delay the proof fermentation time even in the frozen dough manufacturing method.

Further, the present invention also includes providing a method for producing fresh and delicious breads of various blends by utilizing the above yeast without thoroughly controlling the temperature when the bread dough is frozen. Is.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and, as in the prior art,
From the natural world, or from a preserved strain, by screening or mutation treatment, or by breeding operations such as crossing, we obtained a so-called cold-sensitive yeast that has freeze resistance and completely stops fermentation at low temperatures. ,
In the chilled dough baking method, the dough did not mature at low temperature and the proofing time was delayed, which was not satisfactory. Further, in the frozen dough baking method, since the dough is frozen, the temperature of the dough is as low as 10 ° C. or lower under normal thawing conditions, and since the yeast activity is stopped, like the refrigerated dough, Until the dough temperature increased, there was almost no expansion of the dough, and as a result, the proof fermentation time was significantly delayed, and the bread was not satisfactory.

Therefore, the present inventors have fundamentally changed their idea so that they have a strong resistance to frozen dough and fermentation at low temperatures becomes slower than that of conventional baker's yeast, but it does not stop. Focused on the ability to suppress low temperature fermentation.

The present inventors selected strains excellent in freezing resistance from a large number of preserved strains, and using these selected strains as parent strains, breeding operations such as mutation treatment and crossing were carried out to create strains. Regarding, as a result of performing a wide range of screening of the target yeast, it has a strong freezing resistance, and although the fermentation at low temperatures may be suppressed, it is intended to have the ability to suppress low temperature fermentation without stopping. Succeeded in obtaining yeast.

The present invention has been completed as a result of further research based on such useful new knowledge, and the details thereof are as described below.

The yeast used in the present invention may be any yeast that can be used as baker's yeast, but yeasts belonging to Saccharomyces cerevisiae are particularly preferable, and it is essential that they have freezing tolerance and low-temperature fermentation inhibiting ability. Is.
Freezing resistance here means that after the yeast in the bread dough freezes the dough, the expansion force of the dough after thawing
It is the ability to exert the same dough expansion force as bread dough without thawing. In other words, even if you freeze and thaw
It shows a property that the survival rate of yeast in the dough and the decrease in fermentation power are remarkably less than those of ordinary baker's yeast. Further, the low temperature fermentation inhibiting ability means that when the dough is refrigerated and stored at a low temperature, the dough expands more slowly than the dough using ordinary baker's yeast, but the dough expansion slightly continues. . In other words, it is a yeast that has low temperature sensitivity, but compared to normal baker's yeast, fermentation at low temperatures is suppressed, and although it may become slow, fermentation is stopped, missing, or inactive. It is a property that is fundamentally different from the one in which it becomes a natural state.

In the present invention, a strain excellent in freezing resistance was selected from the above-mentioned stored strains belonging to Saccharomyces cerevisiae having freezing resistance and used as a parent strain.
Regarding the selected parent strain, the fermentative power is equal to or higher than that of the parent strain in the normal temperature range at 20 to 35 ° C. from the constructed strain obtained by performing breeding operation by mutation treatment and crossing, and −20
The swelling power of the dough after storage for 2 weeks at ℃ is equal to or higher than that of the parent strain, and the fermentation power in the low temperature range of 0 to 10 ℃ or less is slow or suppressed as compared with the parent strain, but at low temperature. Only strains having the ability to suppress low-temperature fermentation, which did not stop fermentation regardless of the temperature, were selected.

Examples of yeast having such properties include yeasts represented by the following numbers. Saccharomyces cerevisiae P-626 (FERM P-1496
2), Saccharomyces cerevisiae P-627 (FER
MP-14963), Saccharomyces cerevisiae P
-628 (FERM P-14964), Saccharomyces cerevisiae P-629 (FERM P-1496)
5), Saccharomyces cerevisiae P-630 (FER
MP-14966).

Known mutation treatment methods include ethyl methane sulfonate treatment, nitrosoguanidine treatment, and ultraviolet irradiation, and these methods can be used. To select a strain whose fermentation is suppressed in the low temperature range from among the mutagenized strains, it is possible to ferment equally to the parent strain in the normal temperature range and isolate the strain that is suppressed in the low temperature range. Is.

Although it is not clear why the yeast of the present invention slows the expansion of bread dough in the low temperature range, the lipids constituting the cell membrane of the yeast of the present invention which has been mutated are changed, and It is presumed that the fluidity is changed and the sugar uptake is suppressed in the low temperature region, resulting in slowing. Biosci. Biotech. Bioche
m. , 59 (3) 482-486 (1995), describes new findings regarding yeasts whose fermentation and growth are suppressed at low temperatures. In other words, ergosterol, which is the main constituent lipid of the cell membrane, is associated with cold sensitivity of yeast,
At that time, the cold-sensitive yeast cannot take in aromatic amino acids (eg, tryptophan) at low temperatures and becomes auxotrophic for amino acids. However, the yeast of the present invention,
It is considered that this mechanism is different from the low temperature sensitivity of this yeast because it does not require amino acids even at low temperatures.

Generally, temperature sensitivity (Temperat)
It is a well-known fact that a gene involved in ure Sensitive (TS) exists in the genus Saccharomyces, but this low temperature sensitization causes the yeast protein synthesis system to stop and die at high or low temperatures. ,
The property is basically different from the ability to suppress low temperature fermentation according to the present invention.

The following is an example of obtaining the yeast of the present invention.

(1). Method for Mutation Treatment of Yeast Here, ethyl methane sulfonate (hereinafter referred to as EMS) is used.
Is described). From a slant of a yeast strain having freeze resistance as a parent strain, 1 platinum loop, YPD medium (yeast extract 1%, polypeptone 2%, glucose 2
%) Inoculated into 5 ml and cultured with shaking at 30 ° C. for 24 hours. After completion of the culture, the cells are collected by centrifugation at 3,000 rpm for 5 minutes, and washed once with 0.1 M phosphate buffer (pH 7.0). The washed cells were suspended in 5 ml of the same phosphate buffer solution, 0.2 ml of EMS was added, mutagenizing treatment was performed at 30 ° C. for 60 minutes, the cells were collected by centrifugation at 3,000 rpm for 5 minutes, and the phosphate buffer solution After washing with, neutralize by adding 6% sodium thiosulfate to decompose EMS. 5m saline solution
The cells are washed 3 times with 1 and the washed cells are suspended in 5 ml of physiological saline and appropriately diluted and spread on a YPD agar plate prepared by adding 2% agar to the above YPD medium.

(2) Screening method for low-temperature fermentation-suppressing yeast The mutagenized YPD agar plate was cultivated for 2 days at 30 ° C., and the emerged colonies were replicated by another two plates. Transfer to YPD agar plate,
Incubate at 10 ° C for 5 days and at 30 ° C for 2 days. At 30 ° C., a colony showing the same growth as that of the parent strain and at 10 ° C. more suppressed than that of the parent strain (but excluding those that have not grown) is selected as a cold-sensitive yeast.

Further, the isolated strain is subjected to several subcultures in YPD agar medium, and a strain having stable low temperature sensitivity is selected. Next, 1 platinum loop of the selected strain was inoculated in 5 ml of YPD medium, incubated at 30 ° C. for 16 hours, washed, and washed with 1 ×.
Three YPDs (p) containing 30 ppm of bromcresol purple (BCP) at 10 ⁷ cells / ml were prepared.
H6.5) Suspended in 5 ml of medium and kept at 5 ° C for 2 days at 10 ° C
Static culture for 24 hours at 30 ° C. for 3 hours. After culturing, centrifugation is performed at 3,000 rpm for 5 minutes, and the absorbance at 590 nm of the supernatant liquid from which the bacterial cells have been removed is measured by a spectrophotometer. BCP, which is used as a pH indicator, is bluish purple at pH 6.5, changes to yellow as the pH decreases, and the absorbance decreases. Therefore, a strain with a smaller change in absorbance in each temperature range than the parent strain is selected. At that time, although it is a cold-sensitive strain,
Strains that show little or no change in absorbance at 0 ° C compared to the initial one are excluded from the selection criteria because fermentation is stopped at low temperature. In this way,
It is possible to select a yeast strain having an ability to suppress low temperature fermentation.

As described above, an example of obtaining the desired yeast having a low temperature suppressing ability was shown. However, even if fermentation at a low temperature is suppressed by only one-step mutagenesis, the temperature in the room temperature range is suppressed. Since fermentability and freeze resistance tend to decrease, backcrossing is possible as an example of means for avoiding this. Backcrossing is the separation of mutant and wild spore strains, crossing spore strains with different mating types to each other to obtain a cross strain, and then taking a spore strain from the cross strain to obtain spores of the wild strain. This is a method in which the operation of crossing with the strain is performed once or more. By doing this, the genes involved in the ability to suppress low temperature fermentation,
It is possible to create a strain having a gene having excellent fermenting power and / or freezing tolerance of a wild strain.

However, the low temperature fermentation inhibiting ability which is a characteristic of the yeast of the present invention is a recessive inheritance, and even if a spore strain having a low temperature fermentation inhibiting ability and a wild type spore strain are simply crossed, the low temperature fermentation inhibiting ability is suppressed. No ability is expressed and the hybrid becomes wild type. Therefore, obtain a spore strain from a hybrid strain that has become a wild type, by the screening method described above, to select a spore strain having a low-temperature fermentation inhibiting ability, and cross with the original spore strain having a low-temperature fermentation inhibiting ability. is necessary.

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention.

[0029]

Example 1 1. Test strain: Saccharomyces cerevisiae P-626
(FERM P-14962), the same P-627 (FER
MP-14963), the same P-628 (FERM P-
14964) and the same P-629 (FERM P-1496).
5), and the same P-630 (FERM P-14966).
5 stocks.

2. Cultivation: One platinum loop from each slant of each yeast strain was inoculated into 5 ml of YPD medium and shake-cultured at 30 ° C. for 24 hours. Molasses medium (3% as sugar, nitrogen source: urea / ammonium sulfate = 3/1) , Phosphorus source: monosodium phosphate) were inoculated in 200 ml, and the mixture was shake-cultured at 30 ° C. for 48 hours. This was inoculated into a 30 L jar fermenter, and seed culture was carried out while feeding molasses and aerating and stirring at 30 ° C. for 14 hours. The yeast cells obtained by the seed culture were washed and used as seeds for the main culture, and molasses was fed in the same manner as in the seed culture, and the mixture was aerated and stirred at 30 ° C., and alcohol-controlled culture was performed. After the culture was completed, the culture broth was separated, washed with water, and filtered to obtain compressed raw yeast.

3. Dough test method: With respect to various formulations shown in Table 1, the low temperature fermentation inhibiting ability of each yeast was compared. FD for commercial regular yeast and frozen dough as target area
-1 yeast (all manufactured by Oriental Yeast Co., Ltd.) was used. The results are shown in Table 2. In addition, the time course of the dough expansion of the FD-1 yeast and P-626 strains at 5 ° C is shown in Fig. 1.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Figure 1]

As seen in Table 2, P-626, P-627, P-628 and P-62 having the ability to suppress low temperature fermentation.
9 and 5 strains of P-630 have fermentative power of the same level as the regular yeast and FD-1 yeast of the control section in the normal temperature range of 28 ° C in any kind of dough, but 5 ° C In the low temperature range, fermentation is obviously suppressed compared to the control section. If you compare the amount of fabric expansion after 5 hours at 24 hours, 30-40% of the amount of fabric expansion in the control area.
It is a degree.

Further, as shown in FIG. 1, the change in the dough expansion of the P-626 strain having the low temperature fermentation inhibiting ability at 5 ° C. was such that the dough kneaded at 24 ° C. was transferred to the fermentation chamber at 5 ° C. However, the fermentation weakens as the dough temperature decreases, but the fermentation does not stop, and the fermentation is continued at a dough expansion rate of 5 ml / 3 hours after 12 hours. On the other hand, in the case of FD-1 yeast, which has no ability to suppress low-temperature fermentation, the yeast activity decreases and fermentation is suppressed as the temperature decreases, but the expansion rate is 10 ml / 3 hours, which is not as high as that of the P-626 strain.

[0037]

[Example 2] Using the yeast cells obtained in Example 1, dough was prepared according to the formulation shown in Table 3, and the floor was heated to 30 at 28 ° C.
After collecting, the dough was stored at −20 ° C. for 4 weeks, and the change in freezing tolerance of each yeast with time was compared by observing the aptitude proofing time until reaching a predetermined volume at 35 ° C. after 1 hour of thawing at room temperature. did. The results for the butter roll dough (medium sugar dough) are shown in FIG. 2, and the results for the confectionery bread dough (high sugar dough) are shown in FIG.

[0038]

[Table 2]

[0039]

FIG. 2

[0040]

FIG. 3

As is clear from FIGS. 3 and 4, the regular yeast having no freezing tolerance tends to have a longer proofing time after thawing as the frozen storage period becomes longer. Similar to the yeast FD-1 yeast, P-626 to 63 having the ability to suppress low temperature fermentation
It can be seen that, for all 5 strains of No. 0, the proof fermentation time after thawing is extremely stable regardless of the length of the freezing period, and thus all 5 strains have strong freezing resistance. Further, since the fermentation at low temperature is suppressed, the proofing time after thawing the dough is expected to be delayed, but with all 5 strains of P-626 to 630, the proofing time for the dough before freezing and By utilizing the yeast having the ability to suppress low temperature fermentation with almost no change, delay of proof fermentation time, which is a disadvantage of the low temperature sensitive strain in frozen dough, does not occur at all.

[0042]

[Example 3] Of the yeast cells obtained in Example 1, P-6
26 and P-629 strains of two yeasts were used to prepare a dough with the butter roll composition shown in Table 2, and after taking a floor at 28 ° C for 30 minutes, the dough was frozen and stored at -20 ° C for 3 weeks. Thaw in the refrigerator overnight, re-freeze, 1
After 4 weeks, the product was thawed at room temperature for 2 hours, and the appropriate proofing time was measured. The results are shown in Table 4. At the same time, the proof time was set constant (50 minutes) and then baked to prepare bread, and the specific volume of the bread was measured. The specific volume was determined by the rapeseed substitution method.
The results are shown in Table 5.

Further, the dough that had been frozen and stored at −20 ° C. for 3 weeks was thawed in a refrigerator overnight, and the dough that had been refrigerated as it was was kept at a constant proof time (50 minutes).
Baking was performed to prepare bread, the specific volume of the bread was measured, and the quality of the bread was evaluated. Table 6 shows the results.

[0042]

[Table 4]

[0042]

[Table 5]

[0043]

[Table 6]

As is clear from Table 4, the proofing time after re-freezing and storage was delayed by about 10 minutes for FD-1 yeast having strong freezing resistance, but 1-2 for P-626 and P-629 strains. It is about a minute, and refreezing is possible in the case of this yeast. The results shown in Table 4 are obtained among the yeasts having the same freezing tolerance strength during thawing at low temperature.
1 Yeast is reactivated and re-frozen in an activated state, whereas fermentation is suppressed at low temperature P-
In the strains 626 and P-629, the yeast activation is extremely slow even after thawing, so that the effect of refreezing is less likely to occur.

In order to reflect this result, in Table 5, the state of bread after baking was compared, but the specific volume of bread of FD-1 yeast in an activated state at the time of refrigeration was the same as that of the other breads. However, many blisters were formed on the surface of the bread, and at the same time, freezing damage was also observed. Moreover, the fermentation had progressed at the time of thawing, and the flavor had an acid odor. However, in the P-626 and P-629 strains in which low temperature fermentation is suppressed,
Even in the case of re-frozen bread, no blistering was observed on the surface of the bread and the flavor was good with no change, as in the case of normal frozen dough storage.

Table 6 shows the results obtained when the thawed dough was stored as refrigerated. As is clear from Table 6, in FD-1, which has no ability to suppress low temperature fermentation, the dough is fermented during refrigerated storage and the maturing of the dough proceeds excessively. Therefore, as the storage period becomes longer, the gas retention of the dough becomes longer. The power is reduced, the specific volume is reduced, and at the same time the quality of the bread is degraded. On the other hand, P-6
In the 26 strains and the P-629 strains, the fermentation of the dough is slow in the low temperature range, so that the specific volume does not change and the bread quality is stable.

[0047]

INDUSTRIAL APPLICABILITY According to the present invention, a novel yeast having the ability to suppress low temperature fermentation without freezing tolerance and fermentation being suppressed at low temperature and slowing down, but without lack or termination of fermentation was created. . By utilizing a novel yeast having such properties, conventional conventional bread making method, refrigerating dough making method, and frozen dough making method can be performed without changing the composition and the process, and further, frozen dough making method. In the method, when the prepared dough is actually stored in a frozen state, the defrosted dough may be refrigerated as it is, in addition to the case of producing bread by heating after thawing as in the conventional usage method, or It becomes possible to re-freeze and use it after storage, and since it is possible to effectively utilize the remaining thawed dough that is generated at the time of build-to-order manufacturing without disposing, it is possible to contribute to improvement in productivity.

[Brief description of drawings]

FIG. 1 shows the change over time in the amount of dough expansion of refrigerated dough.

FIG. 2 shows the relationship between the frozen storage time of butter roll dough of various yeasts and the proofing time after thawing.

[Fig. 3] Fig. 3 shows the relationship between the frozen storage period of confectionery dough of various yeasts and the proofing time after thawing.

[Table 3]

Claims (6)

[Claims] 1. A yeast of the genus Saccharomyces having freezing resistance and ability to suppress low temperature fermentation. 2. The yeast is Saccharomyces cerevisiae P-626 (FERM P-14962), Saccharomyces cerevisiae P-627 (FERM P-1496).
3), Saccharomyces cerevisiae P-628 (FER
MP-14964), Saccharomyces cerevisiae P
-629 (FERM P-14965), Saccharomyces cerevisiae P-630 (FERM P-1496)
The yeast according to claim 1, which is 6). 3. Breads prepared by mixing raw materials used for bread, water and baker's yeast, and kneading and kneading bread dough, then returning to room temperature, fermenting and / or heat-treating, and baking. The method for producing bread, wherein a bread dough comprising the yeast according to claim 1 or 2 is used. 4. The bread dough according to claim 3, wherein the bread dough is frozen and / or refrigerated dough. 5. One or two yeasts according to claim 1 or 2.
Frozen bread dough containing more than one seed. 6. One or two yeasts according to claim 1 or 2.
Refrigerated bread dough containing more than one seed.