JPH0678754A - Torulaspora delbrueckii h299-18 and production of frozen dough for bread using the same - Google Patents

Abstract

(57) [Summary] [Structure] The chromosomal DNA shows an electrophoretic pattern different from that of Torulaspora delbrutski (a reference culture strain of Saccharomyces rosei), and the optimum growth temperature is slightly on the low temperature side. A method for producing frozen dough for bread, characterized by using Delbrutki H299-18 and this Torulaspora delbrutki H299-18. [Effect] Torraspora delbrutski H29 of the present invention
9-18 has high freezing resistance, and even when it is used for the production of so-called lean frozen dough such as bread, the proofing time after thawing is hardly affected by the length of the pre-fermentation time. Therefore, a frozen dough baking method capable of being frozen and stored for a relatively long period even after sufficient pre-fermentation can be established, which is extremely useful in the baking industry.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to Torulaspora delbrueckii H299-1.
8) and a method for producing frozen bread dough using the same. More specifically, when used in the frozen dough baking method, even if the pre-fermentation time (floor time) is lengthened, there is almost no change in the proofing time after thawing, and the length of lean bread like bread is particularly long. The present invention relates to Torulaspora delbrutski H299-18, which is superior to commercially available freeze-tolerant yeasts in freezing storage for a long time, and a method for producing frozen dough for bread using the same.

[0002]

2. Description of the Related Art In a bakery factory, a lot of work is carried out late into the night and early in the morning, which makes it difficult to operate due to problems in working conditions and lack of labor, and there is also a growing consumer need for fresh bread. Therefore, there is a demand for bread making with frozen dough. In the production of frozen dough, it is ideal that the frozen dough is charged in a conventional manner, and the flavor before fermentation is sufficiently generated by sufficiently performing fermentation before freezing, and then frozen.

However, yeast, which is the most important yeast in the production of frozen dough, generally suffers from physiological damage due to freezing, and there is a problem that the fermenting power after thawing decreases. And, the decrease of this fermenting power is so remarkable that the dough is thoroughly fermented before freezing and the yeast cells are activated, so the pre-fermentation time must be suppressed as short as possible. It was difficult to manufacture a frozen dough that is traditional. Therefore, a freeze-tolerant yeast in which the degree of the decrease in fermentation power due to such a freezing disorder is small has been developed and put on the market.

[0004]

However, conventional freeze-tolerant yeasts are limited in their use to relatively rich breads containing fats and oils, skim milk powder, additives such as dough improving agents, high concentrations of sugar and eggs. This is the current situation, and it is not suitable for long-term frozen storage of relatively lean bread such as bread and French bread.

For example, when the conventional commercially available freeze-tolerant yeast is used for the production of lean bread dough, it is subjected to pre-fermentation for about 1 hour necessary for flavor production and then frozen for 1 month.
The fermentation power after thawing is considerably reduced. Therefore, when making bread using such bread dough, it will take a long time for the proofing, or even if the proofing is performed for a long time, it is no longer possible to produce bread with a quality that can be endured as a product. Disappear.

In view of such circumstances, the present inventors have searched for a freeze-resistant yeast suitable for long-term frozen storage of relatively lean bread. As a result, among yeasts isolated from apples harvested in Hirosaki, there is a fairly high proportion of freeze-tolerant yeasts, and among these freeze-tolerant yeasts, the freeze-tolerant yeasts effective for long-term storage of the lean bread are Was found to exist. Then, as described later, the present inventors isolated this freeze-tolerant yeast and investigated its mycological properties, and found that it was Torrulaspor.
a yeast, which has a mycological property similar to that of A. delbrueckii.
8 (Microtechnology Research Institute, No. 13128).

[0007]

The present invention provides chromosomal DNA
Shows an electrophoretic pattern different from that of Torluspora delbrutki (a reference culture strain of Saccharomyces rosei), the optimum growth temperature is on the slightly low temperature side, and Torraspora delbrutki H299-18 showing high freezing resistance, and A method for producing a frozen dough for bread, which comprises using this Torulaspora delbrutski H299-18.

Torulaspora delbrutski H2 of the present invention
99-18 is a yeast obtained from the surface of apples.
That is, water was sprayed from the top of the apple deposit, about 200 liters of water washed off the surface was collected in a tank and decanted overnight, the supernatant was discarded, and the residue was inoculated into a YEPD liquid medium, leaving the residue. Yeast contained in the test is grown and Y
The target yeast was selected from the single colonies formed on the EPD agar medium.

Next, Torlaspora del Brutski H299
18 shows the mycological properties of -18. (1) Growth status Creamy colonies are formed on YM agar and YEPD agar. The vegetative cells are sprouting and proliferating in a spherical or oval shape having a main diameter of 4.6 μ. (2) Spore formation Well formed in a spore formation medium (sodium acetate medium). One to three spores are found in the asci. Pseudozygote is formed and ascospores are formed, and the frequency of formation is relatively high. (3) No pseudohyphae were formed on the potato-extracted agar medium.

(4) Physiological properties a. Utilization of nitrate: None b. Viable pH and optimum pH It grows well in the range of pH 3.0 to 8.0, and the optimum pH is p
H is in the range of 4.0 to 6.0. c. Growing temperature and optimum temperature The temperature was examined using a shaking temperature gradient culture device manufactured by Toyo Kagaku Sangyo Co., Ltd. That is, the L-shaped tube containing 10 cc of YEPD medium was sterilized, the number of bacteria was adjusted to 1 × 10 ⁵ / ml, and the culture was started. The growth of the fungus was determined by counting the number of fungi. As a result, this strain was able to grow at 11 to 36 ° C and had an optimum growth temperature in the range of 23 to 29.5 ° C. Further, as a control, a reference culture strain of Torulaspora delbrutskii (Saccharomyces rosei: IFO (I
NSTITUTE FOR FERMENTATION OSAKA) No. 1129)
Similarly, when the optimum growth temperature was examined, it was in the range of 25 to 30 ° C. d. Vitamin Requirement: None

(5) Carbon source assimilation and fermentability The assimilation is judged by growth in SD medium (containing 0.15% casamino acid), and the fermentability is other than addition of sugar after sterilization by filtration. Was evaluated by examining the generation of gas by the Durham tube method using the same YEPD medium as usual. The results are shown in Table 1. Further, assimilation and fermentability of Torulaspora delbrutski (a reference culture strain of Saccharomyces rosei) examined under the same conditions as a control also showed almost the same results.

[0012]

[Table 1]

(6) Karyotype Analysis by Pulse Field Electrophoresis The electrophoretic pattern of chromosomal DNA was examined using CHEF-DRII (manufactured by BIO-RAD). The medium composition and the composition of the solution were in accordance with “Cell Engineering (Vol.6, No.2, 1987)”. Further, as a control, Torulaspora delbrutki (a reference culture strain of Saccharomyces rosei) was treated in the same manner, and the patterns of both were compared. This is shown in FIGS. 2 and 3. In FIG. 3, the first and sixth columns from the left are brewing yeasts (Saccharomyces cerevisiae (S
accharomyces cerevisiae)), columns 2, 3, 9 and 10 are Torraspora delbrutki H299-18, and columns 4, 5, 7 and 8 are Torraspora delbrutki (reference strain of Saccharomyces rosei) chromosome D.
The electrophoresis pattern of NA is shown. FIG. 2 shows these Torluspora delbrutskii (reference culture strain of Saccharomyces rosei) and Torluspora delbrutskii H2.
The difference in the electrophoretic pattern of the chromosomal DNA of 99-18 is shown in the drawings for easy understanding. As shown in FIGS. 2 and 3, the reference culture strain used as a control had one more band (the portion indicated by the arrow in FIG. 2), and these two strains showed completely different separation patterns.

The above-described mycological properties suggest that Torluspora delbrutki H299-18 is a species closely related to Torluspora delbrutki. That is, in many respects, the mycological properties of Torulaspora delbrutki H299-18 are the mycological properties of Torulaspora delbrutki (edited by NJWKreger-van Rij, The Yeasts, 3rd revised edition, p. 435, Elsevier Science Publishers, Amsterda).
m, 1984)), but the electrophoretic pattern of chromosomal DNA is significantly different from that of Torluspora delbrutski (a reference culture strain of Saccharomyces rosei), and the optimum growth temperature is also slightly different from that of the reference culture strain. The difference was that it was shifting to the low temperature side.

This bacterium was cultivated under the same conditions as commercially available baker's yeast (Tolulaspora delbrutki) and the culture characteristics were compared. As a result, there was a slight sedimentation property, but the growth and dough fermenting power were not inferior. The dough fermenting power was superior to the commercial baker's yeast after freezing. In addition, the strain is also good in terms of sensory preference, which indicates that Torluspora delbrutki H299-18 is a strain that can withstand practical use.

The method for producing frozen dough for bread according to the present invention is as follows.
Torula spora del Brutuki H299- as baker's yeast
The preparation can be performed in the same manner as in the conventional bread dough manufacturing method except that No. 18 is used. Then, as will be described later, even in the case of producing a so-called lean bread dough, it is possible to perform pre-fermentation for about 60 to 90 minutes, which is sufficient for flavor production, and at about -20 ° C for about 1 month. It can endure frozen storage of.

[0017]

EXAMPLES Hereinafter, the difference in properties between Torulaspora delbruecki H299-18 of the present invention and commercially available freeze-tolerant yeast will be described in detail based on examples.

Example 1 (Bread-making property) Using Torulaspora delbrutki H299-18, the bread-making property was compared with that of a commercially available freeze-resistant yeast. Bread was produced by the straight method and divided into a frozen section and a non-frozen section, and the proof time, bread volume and specific volume of each were examined. The results are shown in Table 4. The dough composition is as shown in Table 2, which is a general dough composition for so-called lean bread. The working process is as shown in Table 3. The yeast cells used were all prepared by squeezing the cells after culturing under the same conditions.
Commercially resistant yeast A is manufactured by Sankyo Foods Co., Ltd., Sankyo Yeast Y
(Brand name), B is Asahi Kasei Kogyo (former company name: Toyo Brewing Co., Ltd.), 45F yeast (Brand name), C is Oriental Yeast Co., Ltd., FD yeast (Brand name), D is Kyowa Hakko Kogyo KK, Diaeast FT-S (trade name), and E indicates Kaneka Green (trade name) manufactured by Kaneka Corporation.

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

As a result of Example 1, as shown in Table 4, when produced without freezing, Torluspora delbrutki H299-18 showed good results in all respects, and when compared with the commercially available freeze-tolerant yeast. But it was comparable. Also, in the case of conventional dough using baker's yeast, in the case of long-term frozen storage, it is necessary to keep the frozen dough at a temperature as low as possible and pre-fermentation time as short as possible, but in this case, 90 minutes Even though it took a long pre-fermentation time, this strain had a slight difference between the frozen and non-frozen regions, and was superior to the E strain, which is said to have the highest resistance among commercially available strains (compared to our company). It showed freeze resistance.

Example 2 (Pre-fermentation and Freezing Tolerance) It is said that commercially available general yeast for breads shows a marked decrease in the fermenting power after thawing as the pre-fermentation time increases.
It is considered that this is because one of the causes is that yeast is easily activated to be affected by the outside world. Therefore, in the present example, a pressed dough of the present bacterium was used to produce bread dough by the same composition and working process as in Example 1, and the dough obtained by changing the pre-fermentation from 0 to 90 minutes was -20 ° C. In 1
It was stored frozen for a week and the residual fermenting power after thawing was examined. The results are shown in Table 5. Also, the same composition and work as in Example 1 except that this fungus and a commercially available freeze-resistant yeast (Kaneka Corporation, trade name Kaneka Green) were used and the specific volume of the mold material was 4 (800 cc type / 200 g material). About the thing which manufactured bread dough in a process and pre-fermented for 30 minutes, 60 minutes, and 90 minutes, it cryopreserved at -20 degreeC for 1 week and 4 weeks, respectively, and the influence of the pre-fermentation time on the proofing time after thawing Examined. This is graphed and shown in FIG.

[0024]

[Table 5]

As a result of Example 2, as shown in Table 5, Torraspora delbrutski H299-18 had a higher fermenting power after thawing as it was subjected to sufficient pre-fermentation. Further, as shown in FIG.
With 0 minutes of pre-fermentation, it could not withstand frozen storage for 4 weeks (about 1 month) and the proof time increased sharply, whereas Torlaspora delbrutski H299-18 was frozen in 90 minutes of pre-fermentation. Even if it survives, it can withstand 4 weeks of long-term storage,
The proofing time was slightly increased as compared with the value when frozen for one week. Sensually, the bread flavor is also good,
In terms of specific volume, both the bulge and the internal phase were comparable.

[0026]

As described above, the Torulaspora delbrutski H299-18 of the present invention has high freezing resistance, and even when used in the production of so-called lean frozen dough such as bread, The proofing time after thawing is hardly affected by the length of fermentation time. Therefore, a frozen dough baking method capable of being frozen and stored for a relatively long period even after sufficient pre-fermentation can be established, which is extremely useful in the baking industry.

[Brief description of drawings]

FIG. 1 is a graph showing the influence of pre-fermentation time on the proof time after thawing.

FIG. 2 is a diagram showing a comparison of electrophoretic patterns of chromosomal DNAs of Torluspora delbrutki (a reference culture strain of Saccharomyces rosei) and Torraspora delbrutki H299-18.

FIG. 3 is an electrophoretic pattern photograph of the chromosomal DNAs of Torulaspora delbrutki (a reference culture strain of Saccharomyces rosei) and Torluspora delbrutki H299-18.

Claims (2)

[Claims] 1. A chromosomal DNA showing an electrophoretic pattern different from that of Torluspora delbrutskii (a reference culture strain of Saccharomyces rosei), an optimum growth temperature on the slightly low temperature side, and high freezing tolerance Torluspora delbrutki H299- 18. 2. Torlaspora delbrutski H299-
A method for producing frozen dough for bread, which comprises using 18.