JPS5948607B2 - How to make frozen bread dough - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing frozen bread dough, and more particularly to a method for producing frozen bread dough using yeast that does not cause freezing damage even when frozen and can maintain high fermentation power.

That is, the present invention is a method for producing frozen bread dough in which bread dough is kneaded, fermented, and then frozen. This is a method for producing frozen bread dough, characterized by using Satscharomyces cerevisiae.

Frozen bread dough is made by mixing bread dough, fermenting it, dividing it into two parts as necessary, shaping it, freezing it at -20 to -40°C, and storing it frozen at around -20°C for several days to several weeks. .

When making bread, the required amount of frozen bread dough is thawed, fermented in an oven, and then baked.

Therefore, frozen dough bread making method i is an extremely advantageous method because it simultaneously solves the problems of eliminating night and holiday work, which are labor measures, and providing fresh bread, which have been difficult to achieve in the past.

However, if frozen bread dough using ordinary baker's yeast is fermented prior to freezing, freezing damage to the yeast increases as the fermentation time increases, and roasting fermentation after thawing is significantly delayed. However, it also has the disadvantage of deteriorating bread quality.

Therefore, when making frozen bread dough, the fermentation process, which is essential for the ripening of the dough and the production of flavor, is actually significantly shortened or omitted altogether, and the dough is shaped and frozen immediately after kneading. I have no choice but to do so.

This is because during fermentation before freezing (hereinafter referred to as pre-fermentation), the yeast changes from a dormant state to an activated state (early logarithmic growth phase), and in this state, baker's yeast is extremely susceptible to freezing damage. This is to make it easier to receive.

Therefore, in order to search for yeast that does not suffer from freezing damage even if it is frozen after sufficient pre-fermentation, the present inventors have repeatedly investigated various types of naturally fermented bread varieties. Ta.

As a result, they were able to isolate yeast with high freezing resistance from seeds made by wrapping wheat flour paste in plant leaves (banana leaves) and fermenting it.

That is, wrap wheat flour paste in plant leaves, ferment this to make a naturally fermented seed, dissolve 1 g of this seed in 100 ml of physiological saline, and add this to YM agar medium (3 g of malt extract, 3 g of yeast extract, 3 g of polypeptone, Grape seed Log was dissolved in 11, poured onto 1llf (20 g of agar added as 4 and 6), cultured at 30°C for 72 hours, and bacteria were collected from the resulting colonies, which were cultured in flat culture. The desired yeast can be isolated.

The mycological properties of the yeast thus isolated are as follows according to the test items in the general yeast identification method.

(1) Morphological properties Streaking culture on wort agar (Difco) slope, wort (D
ifco) culture and potato dextrose agar seal culture on slide culture, 4-7 days and 2
Observation after 0 days.

a Shape: round or oval b Size: 2.5-9 x 3-11 microns (2) Spore formation: Yes The test bacteria were pre-cultured for 3 days on a wort agar slant, and Mr. Gorodokova Agar and potato
The cells were cultured on dextrose agar slants, and the presence or absence of sporulation ability was observed for 7 to 30 days.

(3) Formation of pseudohyphae: None 4) Form of growth: Budding (5) Biochemical properties a Sugar fermentability 2% sugar was added to a 3% yeast extract (Difco) solution,
After dispensing into medium test tubes containing Durham tubes and performing intermittent sterilization for 3 days, a large amount of the test bacteria was inoculated and the presence or absence of gas generation was observed at 25° C. for 14 days.

Fermentability of glucose: Yes Galactose II: Yes Sucrose! 1: There is maltose! ! : Yes (very weak) Raffinose II: Yes 4 Melibiose Il
:None Lactose ll :None b Sugar assimilation Lodder's Auxanobluff (Aux
The assimilation of five types of sugars was tested using the anograph method.

The composition of the basal medium in this test was ammonium sulfate (
(NH4)2SO4)0.5%, acidic potassium phosphate (K
H2PO4) 0.1%, magnesium sulfate (MgSO4
・7H20) 0.05%, agar 2%.

If the results are unclear with this method, use Difco (Difco).
) using yeast nitrogen base,
The test was carried out according to the method of Wickerham.

Glucose anabolism: yes Galactose! ! :can be Sucrose II: Yes Maltose ll: Yes Lactose Il: None Assimilation of C nitrate: None It was conducted in the same manner as the assimilation of sugar.

Potassium nitrate (KNO3) is used as the nitrate, and the composition of the basal medium is 2% glucose, 0.1% potassium acid phosphate (KH2PO4), and magnesium sulfate (MgS).
04/7H20) 0.05% agar 2%.

The above results indicate that this yeast is Saccharomyces cerevisiae.
(Saccharomyces cerevisiae
).

This bacterium is common baker's yeast (Saccharomyces).
cerevisiae), (hereinafter referred to as "commercial yeast"
It is called.

) was cultured under the same conditions and compared in terms of yield, filtration, etc., it was found that the bacterial cells were white in color and had good solubility.

When used in bread making, this bacterium has the effect of improving the flavor of bread, and its resistance to wheat flour's anti-yeast protein (burothionin) is much higher than that of commercially available yeast.

These properties indicate that this bacterium is extremely easy to use and useful when producing and using it as baker's yeast.

However, the greatest characteristic of this bacterium is that it has extremely high freezing resistance, which is not found in general baker's yeast.

Next, we will discuss in detail the differences in properties between this bacterium and commercially available yeast.

(A) Maltose fermentation ability and adaptability The maltose fermentation ability of commercially available yeast cultured in molasses and this fungus was determined using the Mycel method (using a Mycel fermentation tube, 0.25 g each of acidic potassium phosphate and diammonium phosphate were added to the container). 10ml of solution containing and 20ml of distilled water containing 4g of maltose
, 20 ml of distilled water containing 1.5 g of yeast was added, fermented at 30° C. for 5 hours, and the amount of gas generated was measured gravimetrically.

) are shown in Table 1.

In addition, maltose was subjected to adaptation treatment (culture with shaking for 4 hours in a completely synthetic medium containing a large amount of nitrogen source and maltose and its 1710% amount of glucose).

) The ability to adapt to maltose is also shown in Table 1.

As is clear from the table, the maltose fermentation ability of this bacterium is extremely weak compared to that of commercially available yeast, and even when maltose adaptation treatment was applied, almost no adaptation occurred.

(B) Sensitivity to Bureauthionin Sensitivity to the anti-yeast protein Bureauthionin contained in wheat was investigated for its effect on fermentation (5% sucrose solution).

As a result, as shown in FIG. 1, commercially available yeast was severely inhibited in fermentation as the amount of burothionin added increased, whereas this fungus was not affected in any way.

In addition, suspend yeast in aqueous solution of Bureauthionin and
After 7 days of frozen storage at 0°C, the yeast was thawed, washed with water, and the separated yeast was examined for residual fermentation ability. The results are shown in Figure 2.

As is clear from Figure 2, activated cells of commercially available yeast (cells in the logarithmic growth phase) were strongly affected by burothionin, whereas this bacterium was hardly affected in this case either. .

(C) Freezing resistance (C-1) Leakage of glutathione due to freezing A distilled water suspension of molasses-cultured bacterial cells was stored frozen, and the amount of glutathione leaked and the amount remaining in the bacterial cells after thawing was measured, and the results were reported. It is shown in Figure 3.

At the same time, the bacterial cell survival rate was also illustrated.

As is clear from this result, in the case of commercially available yeast, more than half of the yeast die after 2 days and most of the glutathione leaks into the external fluid, whereas with this bacterium, there is little increase in the number of dead and sterilized cells. Despite the high glutathione content within the bacterial cells, there is almost no leakage into external fluids.

Glutathione leaking from yeast cells has the effect of weakening bread dough, so a small amount of leakage is a great practical advantage in bread making.

(C-2) Bread dough containing frozen dough-resistant bread was prepared, and 15
The dough fermented for 0 minutes was stored frozen at -20°C for 7 days, and the remaining fermentation ability after thawing was measured.

Figure 4 shows the results. It is known that if frozen dough is kneaded and immediately frozen, yeast will not suffer from freezing damage, but severe freezing damage will only occur when fermented dough is frozen.

The results of this experiment show that this is true for commercially available yeast, and a significant decrease in residual fermentation capacity was observed as the fermentation time increased.

In bread making, it generally takes 120 to 150 minutes to complete the fermentation process or finish the finishing process, but at this point the fermentation capacity of the frozen raw dough is 80 to 90 minutes.
0% is lost.

On the other hand, this bacterium exhibits a completely opposite tendency, showing a distinctive feature in that the more it is frozen after sufficient fermentation, the higher its fermentation ability after thawing becomes.

This result is directly reflected in the quality of bread.

That is, FIG. 5 shows a cross section of bread baked from these frozen doughs.

As is clear from the figure, when using commercially available yeast, 60
Even with partially fermented frozen dough, the bread crumbles and the inner layer becomes rough due to the reduced fermentation ability of the yeast and the damage caused by leaked glutathione, and this tendency becomes more pronounced as the fermentation time increases.

On the other hand, when using this bacteria, the bread rises well and is of good quality as the fermentation time increases.

As mentioned above, this bacterium has an extremely low ability to ferment and adapt to maltose, is almost insensitive to burothionin, and exhibits extremely high freezing tolerance as a bacterium in an activated state in the logarithmic growth phase. Therefore, it is inappropriate to attribute this bacterium as it is to S. cerevisiae, and it is considered that it should be a mutant strain.

Therefore, the present inventors named this bacterium Satucharomyces cerevisiae FTY (FRI-413).

This bacterium was submitted to FERN P by the Institute of Microbial Technology, Agency of Industrial Science and Technology.
-6363.

According to the present invention, it is possible to sufficiently pre-ferment the bread dough before freezing it, so that the roasting time after thawing the frozen bread dough is short, and the bread expands sufficiently and has excellent flavor. There is.

Another feature of the present invention is that the yeast used as yeast belongs to the same genus and species as Satucharomyces cerevisiae, which has been widely used as baker's yeast for many years, so it is easy to handle in terms of production and use, and has a good effect on the flavor of bread. However, it can even be seen to have positive effects without any negative effects.

Next, examples of the present invention will be shown.

Example 1 Bread dough at a ratio of 100 parts by weight of wheat flour to 2 parts of yeast (this bacteria or commercially available yeast), 1.5 parts of salt, 5 parts of sucrose, and 60 parts of water was kneaded at 30°C. .30
．． After pre-fermenting for 120 or 150 minutes, respectively, the mixture was degassed and stored frozen at -20°C for 7 days.

This frozen dough was thawed at 30°C, and the remaining fermentation ability after thawing was measured.

Figure 4 shows the results.

In the case of commercially available yeast, the longer the pre-fermentation time is allowed, the greater the residual fermentation ability after thawing will be reduced, whereas with frozen dough using this bacteria, the longer the pre-fermentation is allowed, the greater the fermentation after thawing. , it can be seen that it shows a completely opposite trend.

Furthermore, the quality of bread was also better when this bacteria was used.

Example 2 100g of wheat flour, 2g of yeast (this strain or commercially available yeast), 2g of salt, 5g of sucrose, 5g of shortening, and 64g of water
Prepare bread dough with a white bread composition consisting of m1, perform pre-fermentation at 30°C for 0.60.120.150 or 200 minutes, degas, freeze at -20°C, and store at -20°C for 7 days. did.

This frozen dough was thawed at 30°C for 2 hours, then transferred to a roasting furnace at 38°C, and when the dough reached a height of 8 cm, it was placed in an oven and roasted at 218°C for 20 minutes to produce bread.

The time required for roasting fermentation at this time was as shown in Table 2.

As is clear from the table, in the case of commercially available yeast, if the pre-fermentation was not sufficient, it could not reach the specified height even after a long period of time, whereas with the frozen dough using this bacteria, the pre-fermentation was not sufficient. The opposite trend has been shown, in which the roasting time is shortened.

The volume of the frozen dough bread made in this way, the internal phase state,
Figure 5 shows the quality scores.

Bread can only be made using commercially available yeast without fermentation; if pre-fermented for more than 60 minutes, the bread will crumble and quality cannot be graded (less than 50 points and there is no scoring list). The quality could not be called bread.

On the other hand, bread using this bacteria as yeast has a larger volume due to sufficient pre-fermentation.
A clear trend towards improved quality was also observed.

In addition, Table 3 shows the results of an aroma evaluation performed by a panel of 24 people on breads made normally with the same fermentation amount (dough expansion amount).

As is clear from the table, this bacterium has been evaluated as being more robust than commercially available yeast.

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing the burothionin sensitivity of yeast, Figure 3 is a graph showing glutathione leakage and survival rate during frozen storage of yeast suspension, and Figure 4 is the fermentation time of bread dough. Figure 5 shows the relationship between the fermentation time of bread dough and the quality of frozen dough bread. The case using this bacterium is shown. In addition, the numbers shown at the bottom of the figure are the volume of bread (cc) in the upper row.
, the lower row shows the quality score (based on a 100-point scoring system that scores 5 items for interior appearance and 5 items for appearance).

Claims (1)

[Claims] 1. A method for producing frozen bread dough in which bread dough is kneaded, fermented, and then frozen.
A method for producing frozen bread dough characterized by using Satucharomyces cerevisiae, which has a weak fermentation ability, is almost insensitive to burothionine, and exhibits high freezing tolerance as a logarithmic growth phase bacterium. 2 Satucharomyces cerevisiae is Satucharomyces cerevisiae FTY (FRI-413) (FERM
P-6363), the manufacturing method according to claim 1.