JPH07203952A - Novel baker's yeast - Google Patents

Abstract

PURPOSE:To obtain bread, requiring a short proofing time, having a large volume, a moderate baking color and a gloss on the skin and good in springiness durability even in bread made of a frozen high-sugar dough by using a new baker's yeast having the freezing resistance and a low invertase activity. CONSTITUTION:This novel baker's yeast is obtained by adding a baker's yeast having the freezing resistance and <=200U/g (live microbial cell), preferably about 50-140U/g (live microbial cell) invertase activity of a microbial cell before the freezing which is an activity value capable of at least manifesting the minimum sugar hydrolyzing ability to enable the utilization of sugar for fermentation to a dough raw material, mixing them and providing a bread dough. The baker's yeast is prepared by a strain breeding technique such as cell fusion or variation treatment in addition to a syngenetic crossing method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel baker's yeast which is freeze-tolerant and has a low invertase activity or a high sugar resistance, and a frozen dough using the same.

[0002]

2. Description of the Related Art Frozen dough baking technology in recent years has great advantages such as providing fresh bread, saving the bread making process (saving labor), solving labor problems such as eliminating night and early morning work. Has attracted attention in the field of bread making. Frozen dough is prepared by mixing bread raw materials such as wheat flour, sugar, salt, fats and oils, water, etc., fermenting and molding, frozen and stored at around −20 ° C., thawed if necessary, and proof fermentation to be baked.

When bread dough prepared by using ordinary baker's yeast is frozen, it is often killed due to a freezing damage during fermentation and storage, resulting in a decrease in fermentation ability and a delay in proof fermentation time.
It is known to cause a decrease in pan volume.

[0004] Therefore, in the production of frozen dough, there has been a need for baker's yeast which is not easily damaged even when it is frozen, and which is excellent in so-called freezing resistance. For example, Saccharomyces rosei (JP-B-59-25586), Saccharomyces cerevisiae FTY (FRY-413) (JP-B-59)
-48607), Saccharomyces cerevisiae IAM4
274 (JP-A-59-203442), Saccharomyces cerevisiae KYF110 (JP-A-62-20827)
3), Saccharomyces cerevisiae FTY-3 (Japanese Patent Publication No. 4-20595) and the like are known.

[0005]

Particularly in Japan, confectionery bread prepared from bread dough containing a very high sugar content is preferred, but bread yeast of a bread dough containing a high sugar content has a reduced fermenting power. It is known that it causes a delay in proof fermentation time and a decrease in bread volume.

As described above, the known freeze-tolerant baker's yeast is
It had little or no sugar resistance, or at best it was used only up to medium sugar dough, and was quite difficult to use in high sugar dough. Therefore, an object of the present invention is to develop a novel baker's yeast that has freeze resistance and can be used in high sugar dough.

[0007]

[Means for Solving the Problems] The inventors of the present invention have made various studies to improve the strains in order to solve the above-mentioned problems, and as a result, have found that the conventional baker's yeast has favorable freezing resistance and sugar in a high sugar dough. Succeeded in obtaining a resistant strain,
Moreover, it was confirmed that the invertase activity of this strain is extremely lower than that of conventional baker's yeast, and the present invention has been completed.

That is, the present invention has an activity value of 200 U / g (raw), which has freezing resistance, and the invertase activity of pre-freezing cells shows at least the minimum sugar decomposing ability that can utilize sugar for fermentation. The yeast is a baker's yeast characterized by the following: Further, the present invention has a freezing resistance and an amount of carbon dioxide gas generated in fermentation at 38 ° C. for 1 hour in an extremely high sugar dough having a sugar content of 35% is at least 45 m.
It is baker's yeast characterized by being 1 or more.

[0009] Freezing resistance means that it is not damaged or hardly damaged by freezing. The prepared dough is pre-fermented at 30 ° C. for 60 minutes before freezing, and the dough is further cooled to −20 ° C.
It is frozen for 14 days, thawed at 38 ° C. for 20 minutes, and the amount of carbon dioxide gas generated at 38 ° C. for 60 minutes is measured to obtain the fermentation power after freezing. On the other hand, the same dough is pre-fermented at 30 ° C. for 60 minutes, and the amount of carbon dioxide gas generated at 38 ° C. for 60 minutes is measured without freezing, and the fermentation capacity after freezing is compared with that after freezing (for non-freezing). It is calculated as the fermentative power residual rate with the fermentative power as 100). Freezing resistance is exemplified by the case where the residual rate of fermentation power is 80% or more in medium sugar dough with 15% sugar. Further, in the case of high sugar dough with 25% sugar, the fermentation rate residual rate is 85% or more.

The above-mentioned amount of added sugar is indicated by weight% with respect to 100 parts of wheat flour, but in the dough described later, the sugar-free dough is usually a sugar-free dough. The low sugar dough usually refers to a dough containing less than 10% sugar, but in the present invention, a dough with 5% added is representative. The medium sugar dough usually refers to a dough with an added amount of sugar of 10% or more and less than 20%, but in the present invention, a dough with 15% added is representative. High-sugar dough usually refers to dough of 20% or more and less than 35%, but in the present invention, dough to which 25% is added is representative. High sugar content is usually the amount of sugar added,
The term "dough" means 35% or more, but in the present invention, the dough to which 35% is added is representative.

[0011] Invertase is an enzyme that decomposes sugar into glucose and fructose, and baker's yeast secretes this enzyme outside the cells to decompose sugar and then absorbs it.
Used for growth and fermentation. Fermentation in baker's yeast means to generate carbon dioxide gas mainly for inflating bread and the like. In the present invention, if there is no invertase activity, baker's yeast cannot grow in a medium in which there are no assimilable sugars other than starch and added sugar. Ordinary baker's yeast has almost no amylase activity, and normally does not utilize starch as a carbon source required for growth.

[0012] Usually, a small amount of other sugars derived from wheat flour etc. is present in the dough, but it is insufficient to generate and maintain sufficient carbon dioxide gas, and the invertase activity of pre-freezing cells is not sufficient. It is necessary that the activity value is at least equal to or higher than the minimum sugar decomposing ability with which sugar can be used for fermentation. Usually, this activity is exemplified by about 50 U / g (viable cells). Further, when the invertase activity is too high, there are problems as described below, and usually about 200 U / g (viable cells) or less is exemplified, and preferably 1
50 U / g (viable cells) or less, particularly preferably 140 U / g
g (viable cells) or less.

When it has a high invertase activity,
The added sugar is decomposed into a monosaccharide, the osmotic pressure becomes extremely high, the growth environment of the cells is disrupted, and the fermentation is disturbed. As a result, the high sugar resistance targeted by the present invention cannot be achieved. In addition, high sugar (sugar) prepared from conventional baker's yeast with high invertase activity
In the dough, sugar is decomposed to produce monosaccharides,
It was confirmed that the composition ratio of monosaccharides was increasing.

On the other hand, in the high sugar (sugar) bread dough prepared from the baker's yeast of the present invention having a low invertase activity,
There was little decomposition of sugar and the composition ratio of monosaccharides was low. Comparing the bread color intensity of the bread when the two doughs were baked, it was found that the bread yeast dough of the present invention had a lighter color and was baked beautifully. The bread color of the dough breads obtained by adding the same amount of glucose and fructose instead of sugar and using each baker's yeast were too dark. It has been conventionally known that glucose and fructose, which are reducing sugars, are more likely to have a color than sugar, and this is considered to be consistent with this finding.

Bread baked from frozen dough generally tends to have a darker baking color than bread made from non-frozen dough. Therefore, baking temperature and baking time must be controlled sufficiently. However, if the baker's yeast of the present invention having a low invertase activity is used, the baking color can be easily controlled even in a high sugar (sugar) dough.

According to the same experiment, when the baker's yeast of the present invention is used, not only the proof time is short, the bread volume is large, the dough does not sag easily, but the pear skin and epidermis gloss are preferably improved. Was done. In the above-mentioned invertase activity, a living cell means a living cell having a water content of 67% and a solid content of 33%, which is obtained by immediately centrifuging a culture solution cultivated in an ordinary medium, washing and dehydrating. To do. However,
It is also possible to measure the water content and solid content of the actually collected live cells and convert them into the live cells having the above ratio.

In the present invention, the amount of carbon dioxide gas generated during fermentation at 38 ° C. for 1 hour in an extremely high sugar dough having a freeze resistance and a sugar content of 35% is at least 45 ml or more, preferably 50 ml. It is the baker's yeast characterized by the above. In other fabrics, for example,
For low sugar dough with 5% sugar, 160ml or more, 1 sugar
It is preferable that the medium sugar content of 5% has a fermenting power of 150 ml or more, and the high sugar content of 25% sugar has a fermenting power of 85 ml or more. In addition, sugar-free dough without added sugar is 70 ml-9
It is 0 ml.

Furthermore, the present invention provides these baker's yeasts,
This is a method for producing a dough, which is characterized by adding to a dough raw material and mixing. The dough mentioned here mainly includes bread dough, bun dough, pizza dough, and the like. The dough raw materials have different compositions depending on the intended dough, but for example, in bread dough, additives such as flour, sugar, fats and oils, eggs, dairy products, water, and yeast food, emulsifiers are used, and the baker's yeast is added. To be done. Sugar is usually used as sugar, but glucose or fructose syrup may also be used.

When the above dough raw materials and baker's yeast are added and mixed, a dough is prepared by using a mixer or the like. Dough may be added any step of division, primary fermentation, freezing, molding, final fermentation, etc., in particular, in the production of dough using the baker's yeast of the present invention having freezing resistance and sugar resistance, frozen This is a particularly great advantage when performing the process or using a large amount of sugar.

As a method for producing dough or bread,
There are the straight method and the middle seed method. The straight method is a method in which the dough is adjusted and then divided, primary fermentation, molding, and final fermentation are performed. In addition, the intermediate seed method is to adjust the dough using a part of the dough raw materials such as baker's yeast, flour, and water, and after performing the intermediate seed fermentation,
This is a method of adding the remaining dough raw material, adjusting the dough, dividing, molding, and finally fermenting. This dough should be baked into bread. Various materials have been known for a long time regarding the manufacture of the above-mentioned dough and bread, and these can be appropriately referred to.

The invertase activity of the pre-freezing bacterium having freezing resistance is an activity value which shows at least the minimum sugar decomposing ability at which sugar can be utilized for fermentation, and is 200 U / g.
(A viable cell) or less, or the amount of carbon dioxide gas generated during fermentation at 38 ° C. for 1 hour in an extremely high sugar dough having a sugar content of 35% is at least 45 ml or more of the present invention Baker's yeast usually has strong high sugar dough fermenting power, or haploid yeast strain obtained by germination of spores of diploid strain of baker's yeast with low invertase activity, and baker's yeast having freeze resistance. Sexually mated with a haploid yeast strain obtained by germination of spores of a diploid strain, and by the screening method described below, select a strain having freezing resistance, and the invertase activity of pre-freezing cells is low. For example, a strain of 50 to 200 U / g (viable cells) is selected, or the amount of carbon dioxide gas generated by fermentation at 38 ° C. for 1 hour in an extremely high sugar dough having a sugar content of 35% is at least 45 ml. More fungus It can be obtained by selecting a strain. It is more preferable to combine both of the screening for invertase activity and the screening for extremely high sugar resistance.

In the present invention, the baker's yeast is preferably Saccharomyces cerevisiae, but in addition, Saccharomyces rosei, Saccharomyces ubalm, Saccharomyces schivarieri, Torulaspora del Bruky, and in some cases, Cerveromyces thermotolerance. , Saccharomyces spaces, etc. can also be mentioned.

The preferred Saccharomyces cerevisiae of the present invention is Saccharomyces cerevisiae (Sacc
haromyces cerevisiae) 3-2-
The C-7 strain is an example of the most effectively used strain, and
The mycological properties of this strain are as follows. In addition,
This strain has been deposited at the Institute of Biotechnology, Institute of Industrial Science and Technology (FERM P-14013). The deposit date is December 10, 1993.

Bacteriological Properties of Saccharomyces cerevisiae 3-2-C-7 Strain a. Shape circular to egg-shaped b. Size 2-10 × 4-15 μm c. With sporulation d. Assimilation and fermentation of carbon source Assimilability Fermentability D-glucose ++ D-galactose ++ Maltose ++ Saccharose ++ Lactose-galactose ++ Raffinose + ± Starch ---

[0025]

The spore-forming ability in the above-mentioned test was obtained by pre-culturing the cells in a YPD agar medium having the following composition at 30 ° C. for 24 hours.
The herman agar medium was inoculated and cultured at 25 ° C. for 3 to 10 days, and the presence or absence of sporulation was observed.

The YPD agar medium composition (pH 5.5) yeast extract 5g peptone 10g glucose _{40g KH 2 PO 4 5g MgSO 4} · 7H 2 O 2g Agar 20g Distilled water 1000ml

Sherman agar medium composition (pH 7.2) potassium acetate 1 g yeast extract 0.1 g glucose 0.05 g agar 2 g distilled water 100 ml This strain was a diploid strain.

As a method for producing baker's yeast that can be used in the present invention, as described above, in addition to the sexual reproductive mating method, strain breeding techniques such as cell fusion method and mutation treatment method can also be used.

[0030]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 Saccharomyc
es cerevisiae) 3-2-C-7 strain breeding and screening spores of diploid yeast strains belonging to Saccharomyces cerevisiae (our conserved strain) having at least strong high sugar dough fermentation ability and lower invertase activity Obtained by germinating haploid yeast strains obtained by germination and spores of diploid yeast strains belonging to Saccharomyces cerevisiae (preserved strains of our company) that have a strong high dough fermentation ability but a high frozen dough fermentation ability A large number of hybrid diploid strains obtained by sexual reproductive mating with haploid yeast strains were obtained.

Next, from these strains, the residual rate of fermentation power after freezing in medium sugar dough (15% sugar dough shown in Example 3) (after fermenting the medium sugar dough for 30 minutes, -20,
Frozen for 14 days at ℃, thaw at 38 ℃ for 20 minutes, then 38 ℃
The amount of carbon dioxide gas generated during fermentation for 60 minutes at 80 ° C is 80 compared to the amount of carbon dioxide gas generated during fermentation before non-freezing.
Strains with freezing resistance of more than 100% are categorized as
O) and the like, and the high high sugar dough fermenting power is 45
Strains having a volume of ml or more were selected using a thermograph or the like, and further strains having an invertase activity of 50 to 200 U / g were selected.

Three strains satisfying the above conditions and having a good bread-making test result were selected, and one of them was selected as Saccharomyces.
cerevisiae) 3-2-C-7 strain (hereinafter 3-
2-C-7 strain).

Example 2 Comparison of Invertase Activity The invertase activity was measured using live cells of the 3-2-C-7 strain cultured under the following conditions. (A) Cultivation of 3-2-C-7 strain (1) Seed yeast culture One platinum loop of the strain was inoculated into 200 ml of YPD liquid medium in a 500 ml Erlenmeyer flask, and the culture solution was shake-cultured at 30 ° C. for 24 hours. 30l molasses medium in a jar fermenter 15l
Then, the mixture was inoculated into 30 ml of aerated agitated culture at 30 ° C. for 16 hours to prepare a seed yeast for 300 liter jar fermenter culture.

The YPD liquid medium composition (pH 5.5) yeast extract 5g peptone 10g glucose _{40g KH 2 PO 4 5g MgSO 4} · 7H 2 O 2g Distilled water 1000ml

Molasses medium (pH 5.5) Molasses (adjusted to 40% sugar, produced in Philippines) 3.5 l Urea 35 g Ammonium phosphate 30 g Ammonium sulfate 30 g Water 15 l

(2) Culturing in 300 l jar fermenter A 300 l jar fermenter was inoculated with 150 l of the main culture medium and the whole amount of seed yeast cultivated in the 30 l jar fermenter was inoculated and cultured under the following conditions.

Culture conditions Culture temperature 30 ° C. to 32 ° C., Aeration 300 to 400 l / min Stirring 450 rpm pH 5.0 to 6.0 Culture time 16 hours

Main culture medium Molasses molasses (adjusted to 40% sugar, produced in the Philippines) 30 liters (molasses fed into the culture during feeding) Urea 800 g Ammonium phosphate 350 g Water 15 liters The culture broth was immediately centrifuged after the cultivation. After separating the bacterial cells, they were squeezed and dehydrated using a filter cloth to obtain viable bacterial cells having a water content of 65 to 70%.

(B) Measurement of invertase activity 200 mg of live yeast cells was added to 2 ml of 50 mM sugar solution (0.1 M acetic acid-sodium acetate buffer, pH 4.7) to prepare 25
After reacting at 5 ° C for 5 minutes, boiling at 100 ° C for 1 minute and cooling, the glucose concentration produced was measured using a biosensor BF-2 (manufactured by KS Systems), and an invertase contained in 1 g of the bacterial cell was obtained using a calibration curve prepared from an invertase standard product. Converted to activity. The activity value was corrected so that the water content of the viable cells was 67%.

The results of the measurement are shown in Table 1. The invertase activity of the strain of the present invention was 1/2 or less of that of the baker's yeast compared.

[0042]

[Table 1]

The yeasts used for comparison are as follows, and the yeasts used in the following examples were used accordingly. Yeast for ordinary dough ... Saccharomyces cerevisiae 2
37NG (Asahi Kasei Co., Ltd., trade name "45 yeast") Yeast for frozen dough-1 Saccharomyces cerevisiae commercially available frozen dough yeast (Asahi Kasei Co., Ltd., trade name "F yeast") Yeast-2 ... Saccharomyces cerevisiae commercially available yeast for sugar-free frozen dough (manufactured by Asahi Kasei Co., Ltd., trade name)
FC East ”)

Yeast for frozen dough-3 .. Saccharomyces cerevisiae commercially available yeast for frozen dough (manufactured by Kanegafuchi Chemical Co., Ltd.) Yeast for frozen dough-4 .. Torulaspora del Brukey yeast for frozen dough (Sankyo (strains) )) Frozen dough yeast-5 ... Saccharomyces cerevisiae commercially available frozen dough yeast (Oriental Yeast Co., Ltd.) Frozen dough yeast-6 ... Saccharomyces cerevisiae commercial frozen dough yeast (Kyowa Hakko Co., Ltd.) )

Example 3 Fermentability of non-frozen dough The viable cells shown in Table 3 were used to measure the amount of carbon dioxide gas generated during non-freezing in the dough composition shown in Table 2. That is, the raw materials are mixed for 2 minutes with a small complete mixer (National USA), the dough is adjusted to 30 g, and fermented with a thermograph (ATTO) at 38 ° C. for 1 hour. The amount of carbon dioxide gas generated was measured. The results are shown in Table 3.

[0046]

[Table 2]

[0047]

[Table 3]

The strain of the present invention showed a favorable fermenting power in a dough having a sugar content higher than that of a medium sugar dough, and was particularly prominent in a high sugar dough or an extremely high sugar dough.

Example 4 Freezing resistance (medium sugar dough) The medium sugar dough shown in Example 3 was fermented at 30 ° C. for 60 minutes, frozen at −20 ° C. for 14 days, thawed at 38 ° C. for 20 minutes, and then 38 The amount of carbon dioxide gas generated by fermentation at 60 ° C. for 60 minutes was compared and measured using a thermograph. The comparison results are shown in Table 4. As is clear from Table 4, the present invention 3-2-C-
It was confirmed that the 7 strains had strong freezing resistance with a residual fermenting power of 85% or more.

[0050]

[Table 4]

Example 5 Freezing Tolerance (High Sugar Dough) The high sugar dough shown in Example 3 was fermented at 30 ° C. for 60 minutes, frozen at −20 ° C. for 14 days, thawed at 38 ° C. for 20 minutes, and then 38 The amount of carbon dioxide gas generated during fermentation at 60 ° C. for 60 minutes was comparatively measured. The comparison results are shown in Table 5. As is clear from Table 5, the 3-2-C-7 strain of the present invention has a residual fermentation rate of 9
It was confirmed to have a strong freezing resistance of 0% or more.

[0052]

[Table 5]

Example 6 Bread Making Test A frozen dough bread making test was carried out using the above-mentioned viable cells. (1) Sweet bread (25% sugar to wheat flour) A frozen dough bread was made by the following formulation and operation for sweet bread with 25% sugar added (to flour). In this test, the shape of the bread was one loaf type to facilitate comparison of proof time. The amount of dough is as follows 180
g, and the mold is 12.5 cm × 7.5 cm (depth 6 c
m).

Composition Wheat flour 1000 g, skim milk powder 30 g, yeast 60 g, whole egg 100 g, sugar 250 g, yeast food 1 g, salt 8 g, oil and fat 80 g, emulsifier 5 g, water 450 ml

Operation Mixing time (min) L2M3 ↓ L3M2H7 ~
8 Dough kneading temperature (° C) 20 Fermentation time (min) 30 Divided (g) 180 Bench time (min) 15 Freezing temperature (° C) -20 (molded frozen)

Freezing period (days) 28 Thawing temperature (° C) 20 Thawing time (min) 150 Proof temperature (° C) 38 Proofing time (min) Top of mold (depth 6c)
m) until baking temperature (° C.) 200 baking time (min) 18 Bread making test results are shown in Table 6.

Baking using the strains of the present invention was of high quality with a short proof time, a large volume, an appropriate baking color, and a shiny, less pear skin.

[0058]

[Table 6]

In Table 6, the meanings of the proofing time, the volume, the intensity of the baked color, the gloss of the epidermis and the degree of pear skin are as follows. Proof time: The time during which the dough was fermented and swelled to reach the upper part of the mold when the dough was mold-molded and the final fermentation was performed. Volume measurement: The volume of bread immediately after baking was measured (bread volume).

Evaluation score for the intensity of baked color 3+: Moderate 2+: Slightly dark, +: Evaluation score for dark skin shine 3+: Fair, 2+: Slight, +: Not very much Pear skin degree Evaluation point 3+: Less preferred, 2+: Somewhat unfavorable, +: Significantly unfavorable

(2) Sweet bread (20% sugar to wheat flour) For sweet bread with an added amount of sugar of 20% (to flour), in order to confirm the softness of the dough, as follows, without mold filling A frozen dough bread test was performed by rounding.

Mixing 1000 g wheat flour, 30 g skim milk powder, 50 g yeast, 80 g whole egg, 250 g sugar, 1 g yeast food, 13 salt
g, oil 80g, emulsifier 5g, water 480ml

Operation Mixing time (min) L2M3 ↓ L3M2H7 ~
8 Dough kneading temperature (° C) 20 Fermentation time (min) 30 Divided (g) 50 Bench time (min) 15 Freezing temperature (° C) -20 (molded frozen)

Freezing period (days) 28 Thawing temperature (° C) 20 Thawing time (min) 150 Proof temperature (° C) 38 Proofing time (min) 50 Baking temperature (° C) 200 Baking time (min) 10 Baking test results The results are shown in Table 7.

The bread using the strains of the present invention was of high quality with good dough holding (low dough sagging), large volume, and moderate brown color with little pear skin.

[0066]

[Table 7]

In Table 7, the evaluation points for holding the waist are as follows, and the other points have the same meanings as described in Table 6. 3+: Good, 2+: Slightly sagging, +: A lot of sagging

Example 7 Sugar composition in the internal tissue of bread The sugar composition in the internal tissue of the bread prepared in Example 6 (1) was examined. Distilled water (45 g) was added to the internal tissue (5 g) of the bread, and the mixture was sufficiently stirred and mixed, and then centrifuged, and the sugar composition contained in the centrifuged supernatant was measured by high performance liquid chromatography under the following conditions.

Conditions for sugar analysis Column: Asahipak NH2P-50 (manufactured by Asahi Kasei) 4.6 mm I.D. D × 250 L Mobile phase: CH ₃ CN: H ₂ O = 75: 25 Flow rate: 0.8 ml / min Detector: RI Column temperature: 30 ° C.

Table 8 shows the contents and composition ratios of sugar, glucose, fructose and maltose contained in the centrifuged supernatant. Although there is no big difference in the total weight of the above saccharides, when the composition ratios were compared, the strain of the present invention had an extremely high proportion of sugar and a lower proportion of glucose and fructose than the yeast-1 for frozen dough. . Since the strain of the present invention has lower invertase activity than yeast-1 for frozen dough, it is presumed that the rate of sugar decomposition in the dough is slow and the amount of residual sugar is large. The Maillard reaction between sugars and amino acids, which is the main cause of browning (baking color) of the bread surface during baking, easily occurs with reducing sugars (glucose, fructose) and is less likely to occur with non-reducing sugars (sugar). Therefore, it was presumed that the baking color of the bread using the strain of the present invention containing a large amount of sugar and a small amount of glucose and fructose was the cause of the light brown color.

[0071]

[Table 8]

Example 8 Baking test in which the type of sugar used was changed In order to confirm whether or not the difference in the baking color of bread was due to the difference in the sugar composition in the dough, the type of sugar used in the dough was set to 1 A) Breadmaking trial was attempted as an) mixture of sugar, 2) glucose and fructose.

The test was carried out according to the method for producing confectionery bread of Example 6 (1), and the sugar added at that time was 1) sugar, 2) an equal mixture of glucose and fructose as described above.
The sugar composition of the baked bread was measured according to the method of Example 7. The results of the bread making test and the sugar composition ratio of the bread are shown in Table 9.

[0074]

[Table 9]

In Table 9, G + F mixture ... Means glucose and fructose mixture. The bread using the strain of the present invention in combination with sugar had the shortest proof time, the largest volume, the lightest baked color, glossy epidermis, and high quality with less pear skin. Bread in which the strain of the present invention was used in combination with glucose and fructose was inferior to the use of sugar in terms of proof time, volume, baking color, gloss of epidermis and pear skin.

In comparison of sugar composition ratio and baking color, glucose
Bread with a high fructose ratio tends to have a darker baking color and bread with a lower fructose ratio tends to have a lighter color. The difference in baking color in the bread making test of Example 6 (1) is due to the difference in the constituent sugars in the dough. I think that the.

[0077]

Industrial Applicability As described above, the strain of the present invention which has strong freezing resistance and low invertase activity or has a strong fermentative power from medium sugar dough to highly high sugar dough is frozen. Even when used in bread made from high sugar dough, it is possible to obtain bread of good quality with a short proof time, a large volume of bread, a moderate baking color, a shiny epidermis with little pear skin, and good luster. I can.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Daihachi Hirose, 632-1, Mifuku, Oni-cho, Takata-gun, Shizuoka Prefecture Asahi Kasei Kogyo Co., Ltd. No. 1 Asahi Kasei Kogyo Co., Ltd.

Claims (4)

[Claims] 1. A freeze-tolerant and invertase activity of pre-freezing cells is an activity value showing at least a minimum sugar decomposing ability that can utilize sugar for fermentation, and is 200 U /
baker's yeast characterized by being less than or equal to g (viable cells). 2. A baker's yeast having a freezing resistance and an amount of carbon dioxide gas generated by fermentation at 38 ° C. for 1 hour in an extremely high sugar dough having a sugar content of 35% is at least 45 ml or more. . 3. The activity value of freezing resistance and the invertase activity of pre-freezing cells is an activity value showing at least the minimum sugar decomposing ability that can utilize sugar for fermentation, and is 200 U /
Add baker's yeast of less than g (viable cells) to the dough material,
A method for producing a dough, which is characterized by mixing. 4. A baker's yeast having a freezing resistance and a carbon dioxide gas generation amount of at least 45 ml or more generated by fermentation at 38 ° C. for 1 hour in an extremely high sugar dough having a sugar content of 35% is used as a dough raw material. A method for producing a dough, which comprises adding and mixing.