JPH0793857B2 - Method for producing bread using lactic acid bacteria - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing breads using lactic acid bacteria. More specifically, it relates to a method for producing breads, which comprises selecting an alcohol-resistant strain from lactic acid bacteria, allowing the lactic acid bacteria to be present in the dough, and aging the dough.

(Problems to be solved by conventional techniques and inventions) Breads are obtained by kneading wheat flour as a main component and kneading fats, yeasts, sugars, salt, dairy products such as skim milk powder, and auxiliary materials such as water. It is produced by baking after aging, but the mechanical resistance of the dough for factory production, the internal and external phases (crust) related to the texture, the flavor unique to bread, and the retention of freshness of the product ( Complex functions such as anti-aging) are required.

Regarding these characteristics, various studies have been added, such as the quality of the main and auxiliary materials, the influence of mechanical operations such as kneading of the dough (mixing), the difference in the aging process, etc., and the improvement method has been found. Due to subtle changes in raw material quality and subtle changes in ripening conditions, there are changes in the bread dough condition and product quality, and it is necessary to take measures based on the experience of skilled experts. It was Industrially, various bread improvers have been developed, and for example, there is a situation in which the physical properties required for machine production have to be imparted, at the expense of some flavor characteristics.
There is a need for new technological means to meet the diversifying and consuming needs for more delicious breads. That is, there has been a demand for a method for industrially stably producing breads having a rich flavor that has been sufficiently ripened originally.

2 belonging to the genus Satsucaromyces, such as sourdough bread
More than one species of wild yeast, for example, Saccharomyces equinogus, Saccharomyces culvertus, Saccharomyces
Lactobacillus, such as Chrysalieri and Torula yeast, and lactic acid bacteria belonging to the genus Lactobacillus, such as Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus farmentii, Lactobacillus casei, Lactobacillus pastorianus, etc. Although it has been used for a long time mainly in Europe and the United States as a method of utilizing the unique flavor of the synergistic action of, there is a large fluctuation and a technology based on many years of experience is required. Although there is a report suggesting the relation of lactic acid bacteria normally contained in yeast as a factor affecting the flavor of bread, it has not been established as a technique for improving or controlling the flavor. Also, the flavor of bread differs slightly depending on the manufacturer of baker's yeast,
It has been empirically known that even the same type of baker's yeast has a slight variation in flavor, but the cause of the difference is not clear and no effective improvement method has been found.

(Means and Actions for Solving Problems) The present inventors selected a lactic acid bacterium that metabolizes malic acid derived from flour and increases lactic acid livestock production in a yeast-containing dough, and selected the lactic acid bacterium from breads. By using for dough preparation,
It was discovered that breads with excellent flavor can be obtained with the effect of improving the dough, and a patent application has already been filed. After that, a detailed study was conducted on these lactic acid bacteria that have an active metabolic ability in the dough, and as a common property, the property of "alcohol tolerance" that grows in the presence of high concentration of ethanol and exerts metabolic ability is shown. Found to have. Based on this knowledge, we selected strains that can grow in high-concentration ethanol from many lactic acid bacteria, and examined the effect on aging in dough containing yeast.
The strains that do not have alcohol tolerance die in the dough or show almost no metabolic ability, while exhibiting the original metabolic ability and improving the bread-making effect. It was confirmed that the effect on the characteristics was small.
That is, it was made possible to select a lactic acid bacterium having a bread-making improving effect extremely efficiently using “alcohol tolerance” as an index, and it was found that such a lactic acid bacterium can be used as an improving method for the production of breads. Was completed.

Although a method of using an alcohol-resistant strain of baker's yeast (Saccharomyces cerevisiae) for the production of breads is known,
No method is known for selecting alcohol-resistant strains of lactic acid bacteria and using them for the production of breads.

Although the details of the mechanism of the present invention are not clear,
It is known that a relatively high concentration of ethanol accumulates in the yeast-containing dough, and the metabolism of normal lactic acid bacteria is suppressed by the presence of ethanol, whereas that of alcohol-resistant strains is weakly suppressed. , It seems that it exerts its original metabolic ability. However, it is generally reported that lactic acid bacteria have stronger alcohol tolerance than other bacteria, and the amount of ethanol accumulated in the dough is about 1.0 to 2.0%, so the presence of alcohol does not have much effect. It seems that the general view was that it was. By analogy with the findings of the present inventors, the aging (fermentation) of semi-solid dough may partially reach a high alcohol concentration, and other ingredients in the dough It is considered possible that a stronger inhibitory effect is obtained at a low concentration due to the synergistic action of.

Hereinafter, the content of the present invention will be described in detail.

First, the alcohol-resistant lactic acid bacterium (alcohol-resistant strain) referred to in the present invention can be selected by the following method. Lactic acid bacteria are defined as bacteria that produce lactic acid in a yield of 50% or more from sugar.

Examples of the lactic acid bacterium include strains belonging to the genus Lactobacillus, the genus Leuconostok, the genus Streptococcus, and the genus Pediococcus. It can also be separated from natural products such as dairy products, fruits, brewed foods, baker's yeast products, cereals such as flour, and foods. Breeding strains such as mutation-treated strains of lactic acid bacteria and cell fusion strains can also be used. Typical examples are Lactobacillus bulgaricus and Lactobacillus
Casei, Lactobacillus brevis, Lactobacillus
Fermentum, Leuconostok Oyanos, Streptococcus thermofilus, Pedeiococcus
Halofilas and the like.

As a method for selecting an alcohol-resistant strain from a sample containing a large number of these lactic acid bacteria or a breeding strain such as a mutant-treated strain of lactic acid bacteria, for example, the following method is adopted.

(I) Concentration of alcohol-resistant strains Lactic acid bacteria were previously grown in a nutrient medium and ethanol was added to 5-12
Inoculate 10 ³ to 10 ⁶ cells / ml into a medium containing 10% by weight and perform static culture at 30 to 40 ° C. When bacteria are generated, further inoculate in a medium containing ethanol and repeat this operation, accumulation culture (Enrichment culture) can be used. It is preferable that the ethanol concentration be gradually increased. In this process, the alcohol-resistant strains are concentrated, and finally, the diluted solution is spread and cultured in a solid medium (plate) containing 8% or more of alcohol, and the grown colonies are picked to obtain the alcohol-resistant strains. To be The productivity of lactic acid can be simultaneously checked by adding calcium carbonate or a pH indicator to the plate medium. That is, organic acids (mainly lactic acid) accumulate around colonies of lactic acid bacteria and form halos according to the acid-producing ability.

(Ii) Judgment of resistant alcohol concentration Regarding the isolated and identified strains, the following method can be mentioned as a method for judging alcohol resistance (although ethanol was adopted, propanol, butanol, isopropanol, isobutyl alcohol, etc. were used. It can also be used. In this case, the judgment criteria differ depending on the type of alcohol).

As usual, pre-cultured in lactic acid bacteria nutrient medium, to the test medium with ethanol added to a predetermined concentration, with the initial number of bacteria 10 ⁶ / ml, add the pre-cultured solution, 24-72 hours at 25 ~ 37 ℃ Incubate. The turbidity of the medium at 660 nm for 24 and 72 hours is measured, and a growth curve is obtained for each concentration of ethanol. The determination of alcohol tolerance is a measure of alcohol tolerance when the OD value after 72 hours is 5 times or more of the initial value and the amount of lactic acid produced is 0.5 mg / ml or more in the medium.

Examples of the alcohol-resistant lactic acid bacterium that can be used in the present invention include a resistant strain having a resistant alcohol concentration of 8% or more, preferably 11% or more, such as Lactobacillus casei.
sei) 6B1, Lactobacillus
brevis) IFO 13110, Lactobacillus casei K-3 (L
actobacillus casei K-3) (deposited to the Institute of Microtechnology as Microtechnical Institute Article No. 1628) and Leuconostoc oenos ATCC 23279.

As a method of allowing the lactic acid bacteria selected by the method of the present invention to be present in the bread dough, a method of adding the lactic acid bacteria as a starter when kneading the dough, a method of adding as a liquid species,
A method of mixing with yeast products such as baker's yeast, a method of using as an oil and fat composition mixed and emulsified in the water phase part of oil and fat, and an old noodle method used by refrigerating and storing a part of the finished dough. can give.

As a method of mixing with baker's yeast, commercially available baker's yeast (65 ~
Wet microbial cells containing 75% water) are dissolved in water to give a milky yeast suspension, or yeast milk in which yeast cells have been separated and washed after the culturing step in the yeast manufacturing process is added with a culture solution of lactic acid bacteria, and vacuumed. There is a way to have.

The cake-like or granular wet cells obtained are stored refrigerated,
Although it is used for the production of breads, it can also be used as dried yeast by fluidized drying or the like.

As a method of using as an oil and fat composition, 10 ⁶ ~ 1 in the aqueous phase part
0 to 50 parts of lactic acid bacteria added at ⁹ cells / ml, oil and fat part 95
.About.50 parts, and an emulsifier 0.1 to 5 parts emulsified oil and fat composition. It is also possible to use a liquid obtained by adding lactic acid bacteria to a liquid obtained by treating wheat flour or active gluten with a yeast self-digesting liquid as an aqueous phase part. It is effective as a method for preparing an oil / fat composition at a low temperature of 30 to 40 ° C by utilizing the emulsifying power of a processed product of wheat flour or active gluten. It is also possible to emulsify the oil and fat composition with a liquid obtained by inoculating a 5 to 30% flour suspension with lactic acid bacteria and growing the lactic acid bacteria at pH 4 to 7.

The concentration of lactic acid bacteria in the dough is 10 ⁴ to 10 ⁹ pieces / g (fabric)
However, when the dough aging time is within 4 to 6 hours, it is preferably in the range of 10 ⁵ to 10 ⁹ pieces / g (dough), 8 hours or more such as low temperature long-time fermentation and aging of the cracker dough. When the aging time of is taken, the effect can be exhibited even at a low concentration of 10 ⁴ to 10 ⁶ pieces / g (dough).

The characteristics of the dough aging of the method of the present invention, as compared with the usual case,
The pH of the dough drops rapidly and the aging process proceeds in a shorter time. Regarding the accumulation of organic acids in the dough, lactic acid bacteria actively utilize the substrate derived from wheat flour or an auxiliary material, and the accumulation of lactic acid progresses from the early stage of ripening. As a typical phenomenon, malic acid derived from wheat flour is consumed, and a higher concentration of lactic acid than usual is accumulated in the dough. Therefore, the organic acid analysis of the product after baking shows a low malic acid content and a high lactic acid content. According to the present invention, when alcohol-resistant lactic acid bacteria are used, the content of malic acid in bread products is 25 mg%.
Hereinafter, 50 mg% or more of lactic acid is shown. That is, according to the method of the present invention, previously found by the present inventors, metabolizing malic acid derived from wheat flour in a yeast-containing dough, it is possible to efficiently select cells that increase the accumulation of lactic acid. Admitted.

The alcohol-resistant lactic acid bacterium selected according to the present invention has not only a characteristic of consuming malic acid and increasing lactic acid accumulation, but also an active characteristic in the dough depending on the inherent metabolic ability of the lactic acid bacterium used. Shows the course of metabolism.

The breads referred to in the present invention include bread, French bread,
Examples include English bread, bread such as sweet bread, biscuits, and crackers.

(Effect of the invention) Conventionally, attempts have been made to use lactic acid bacteria as a method for accelerating dough ripening of breads or for the purpose of improving the flavor, but most lactic acid bacteria cannot exert their functions in the dough, The reason that could not be established as an effective technical means for controlling or improving the breadiness is considered to be a lack of a view point on the influence of lactic acid bacteria on the alcohol produced by yeast. According to the present invention, it was possible to control the accumulation of organic acids in the aging of the dough, which was difficult to control by the conventional method, and thereby, the physical properties of the dough, the flavor, etc. What can be improved is the greatest progress. Further, it is an important use that it is possible to efficiently select, from many lactic acid bacteria, a strain having an effect of improving bread-making property by an index of "alcohol tolerance". For example, from a large number of strains obtained by breeding means such as mutation treatment, a large amount of labor and time are required in the conventional method to select a strain exhibiting an effect of improving bread, but the method of the present invention is simple. An excellent strain can be selected in a short period of time by various operations.

In addition to the above, the effects of the present invention include not only the improvement of the flavor of breads but also the high effect of stabilizing and improving the physical properties of dough such as mechanical resistance. It is also possible to shorten the dough aging time. For example, when applied to straight bread, the lactic acid bacteria work to accumulate lactic acid in the dough and lower the pH in a shorter time, and the middle seed method with excellent mechanical resistance (longer fermentation is required). Since the dough physical properties comparable to those of the dough can be obtained, the characteristics of the straight method, which is excellent in flavor and texture, can be applied to production in a factory.

(Example) Hereinafter, the present invention will be described with reference to Examples.

Example 1 Among lactic acid bacteria, strain 2 which consumes malic acid derived from wheat flour and accumulates a considerable amount of lactic acid in a bread-making dough containing yeast.
Strains: Lb. casei 6B1 ^* , Lactobacillus brevis IFO 13110, and 2 strains that do not exhibit such properties: Lb. acidophilus K-35. ^** , alcohol for Streptococcus lactis K-40 ^** (* is sold by the Faculty of Agriculture, Okayama University, ** is purchased from Kristian Hansen, and the inventor has given the strain name) We compared the resistance. Each lactic acid bacterium was cultivated in a nutrient medium for lactic acid bacteria, and each strain was subjected to static culture at 30 ° C. for 72 hours in a nutrient medium containing 5 to 11% of ethanol, and the growth rate of lactic acid bacteria was compared at a turbidity of 660 nm. . The amount of lactic acid produced after the completion of the culture was measured by high performance liquid chromatography (LC-6A manufactured by Shimadzu Corp.).

(Nutrient medium for lactic acid bacteria) Glucose 10 g Peptone 10 g Yeast extract 5 g Tween 80 1 g L-cystine hydrochloride 0.1 g Water 1 pH 6.8 to 7.0 The obtained results are shown in FIG. 1 and Table 1.

As shown in FIG. 1 and Table 1, two strains showing characteristic metabolic activity in bread dough grow in the presence of 8% or more alcohol, whereas general lactic acid bacteria grow in the presence of 8% or more ethanol. You can see that it can be suppressed. Since there is a difference in the degree of growth even with 5% ethanol, it is suggested that the activity expression may be suppressed even in the range of 5 to 7% when other components or metabolites are present in the dough. The degree of lactic acid production corresponds to the degree of growth of bacteria, and it is shown that the alcohol resistance of lactic acid bacteria can be compared by the degree of lactic acid production in the presence of alcohol.

Example 2 An attempt was made to isolate lactic acid bacteria in yeast (commercial baker's yeast).
That is, yeast is dissolved in water and diluted with sterilized physiological saline, lactic acid bacterium selective medium (in order to suppress yeast dough, 100 ppm of cycloheximide is added, and 0.2% calcium carbonate is added for the purpose of checking the production capacity of lactic acid. Was used to perform flat plate culture, and a strain producing a ring (halo) dissolved around the colony was collected and stab culture was performed. Twenty strains were collected, inoculated into the nutrient medium for lactic acid bacteria shown in Example 1, and statically cultured at 30 ° C. for 2 days, and 0.1 ml was inoculated into 10 ml of the nutrient medium for lactic acid bacteria containing 11% ethanol. Static culture was performed at 30 ° C. for 3 days. 1 out of 20 shares
The growth of the strain was shown. The obtained strain is plated on an agar medium containing 8% ethanol, and the growing strain is strained to a test tube medium (0.5 g of calcium carbonate on the agar medium).
Content). The mycological properties of the strains are shown in Table 2. As a result, Lactobacillus casei K-3
1628) was identified.

As a result of examining the alcohol tolerance based on Example 1, 11
The change in turbidity at 72 hours at 660 nm in the medium containing% ethanol was 0.370, and the accumulation of lactic acid (72 hours) was 1.92 mg / ml, confirming alcohol tolerance.

Example 3 Using the alcohol-tolerant lactic acid bacterium Lactobacillus casei K-3 obtained in Example 2 (Microtechnical Research Institute No. 1628), a bread-making test of medium-type bread was attempted.

When the amount of lactic acid bacteria mixed in the baker's yeast used was measured, it was found to be about 10 ⁸ cells / g (wet yeast cells). When the alcohol tolerance of lactic acid bacteria was examined in the same manner as in Example 2, no lactic acid bacteria capable of growing in the presence of 8% or more alcohol were found. This baker's yeast was used in the next bread making test.

Alcohol-resistant lactic acid bacteria were added by concentrating them by centrifugation and culturing them in a nutrient medium for lactic acid bacteria (per 1 g of dough).
Equivalent to 10 ⁶ pieces).

(Dough mix) Medium mix Wheat flour (strong flour) 70 parts Yeast food 0.1 part Yeast (commercial baker's yeast) 2.0 parts Water 40 parts Lactic acid bacteria liquid 2 parts Main kneading mix Wheat flour (strong powder) 30 parts Oil (shyotoning) 5 parts Sugar 5 Part Salt 2 parts Skim milk powder 2 parts Water 25 parts (Operation) 1) Kneading conditions (medium type) low speed 3 minutes, high speed 1 minute (main kneading) low speed 2 minutes, medium speed 1 minute, high speed 5 minutes Oil input low speed 1 minute , Medium speed 1 minute, high speed 5 minutes 2) Kneading temperature 27-29 ℃ 3) Fermentation time 4 hours and a half bench time 20 minutes Proofing time 40-60 minutes (indicated by the time to reach a certain volume) 4) Firing temperature, Figure 2 shows the results of high-performance liquid chromatography measuring changes in organic acids during the baking process at 180 ° C for 35 minutes. The bread-making results are shown in Table 3.

As shown in FIG. 2, it is noted that when alcohol-resistant lactic acid bacteria are used, malic acid is consumed from the early stage of intermediate-type fermentation, and lactic acid accumulation increases. Although the lactic acid bacteria contained in the baker's yeast used were at a level of 10 ⁶ cells / g (dough) in the dough, lactic acid accumulation was small and malic acid was hardly changed.

As shown in Table 3, the characteristics of the bread were excellent in viscoelasticity of the dough and in good condition in the moulder. It was evaluated that the proofing time was shortened and the flavor was excellent.

Example 4 The lactic acid bacterium Lactobacillus casei K-3 obtained in Example 2
(Microtechnology Research Article No. 1628) and the strain Lactobacillus casei 6B1 shown in Example 1 were cultivated in a nutrient medium and concentrated by centrifugation to obtain commercially available baker's yeast in water. A cake-like yeast cell containing 10 ⁸ lactic acid bacteria per 1 g of wet yeast of baker's yeast containing about 70% of water was prepared by adding to the suspended liquid (concentration of wet cell of 60%) and applying a vacuum. . Using the obtained yeast cells, a bread-making test of straight bread was attempted.

(Dough mix) Wheat flour (strong flour) 100 parts Sugar 5 parts Salt 2 parts Cyotoning 5 parts Yeast 2.5 parts Yeast food 0.1 parts Nonfat dry milk 2 parts Water 69 parts (Operation) Mix the raw materials excluding the chyotoning, low speed 2 minutes, medium speed 1
Min, high speed for 5 minutes, add shyo toning, low speed for 1 minute, medium speed for 1 minute, high speed for 5 minutes, knead to 28 ℃, ferment at 30 ℃ for 1 hour, punch and ferment for another 30 minutes Continued. Then, splitting, rounding, molding, and molding with a moulder were performed, and proof fermentation was performed at 30 ° C and 80% humidity.
After proofing (until the case reaches the level of 1.5 cm)
It was fired. The results of bread making are shown in Table 4.

Example 5 In order to examine the difference between the bread produced by the method of the present invention and the commercially available bread, the internal phase (crumb) of 10 kinds of bread was examined.
An attempt was made to analyze the organic acids in the solution. That is, 10 g of the internal phase of bread was added, 30 ml of water was added, and after homogenization, the supernatant obtained by centrifugation was filtered and the liquid was subjected to high performance liquid chromatography to determine the content of organic acid. Examined. The results obtained are shown in Table 5.

As shown in Table 5, examples of characteristics of the present invention include low malic acid content and very high lactic acid content. Since lactic acid increases more than the amount of malic acid consumed, lactic acid accumulates using, for example, metabolites provided by yeast and ingredients derived from the main and secondary ingredients of dough, such as flour and skim milk powder, as substrates. It is possible that you are doing it.

[Brief description of drawings]

FIG. 1 is a graph showing the alcohol tolerance of lactic acid bacteria tested in a medium supplemented with 5%, 8% and 11% ethanol, FIG.
FIG. 4 is a graph showing changes in major organic acids during a bread making process using the alcohol-resistant lactic acid bacterium obtained in Example 2.

Claims (6)

[Claims] 1. A method for producing bread, wherein an alcohol-resistant strain is selected from lactic acid bacteria in the production of bread, and dough ripening is performed using one or more of the lactic acid bacteria. 2. The method according to claim 1, wherein the lactic acid bacterium is an alcohol-resistant lactic acid bacterium capable of growing and producing lactic acid in the presence of 11% or more of ethanol. 3. The production method according to claim 1, wherein the lactic acid bacterium is a strain selected from strains belonging to the genus Lactobacillus and the genus Leuconostoc. 4. 10 lactic acid bacteria having alcohol tolerance per 1 g
^{The process according} to claim 1, wherein the pressed baker's yeast containing ⁴ to 10 ⁹ baker's yeast, dried yeast, or these baker's yeast products is used for bread dough. 5. Breads characterized in that the contents of malic acid and lactic acid in bread products are 25 mg% or less and 50 mg% or more, respectively. 6. A lactic acid bacterium having alcohol resistance per 1 g
Bread for bread containing 10 ⁴ to 10 ⁹ pieces / g.