JPH01174321A - Preparation of breads using lactobacillus - Google Patents

Abstract

PURPOSE:To prepare the above bread having excellent taste and flavor while controlling the accumulation of organic acid during aging process, by selecting an alcohol-resistant strain from lactobacilli, adding and mixing the resistant lactobacillus to bread dough and aging the dough. CONSTITUTION:An alcohol-resistant strain is selected from lactobacilli, the resistant lactobacillus is added to a yeast product such as bread yeast, added to bread dough, mixed and aged to obtain the objective bread. The above lactobacillus is preferably an alcohol-resistant strain which can be grown and produce lactic acid in the presence of >=11% of ethanol.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing bread using lactic acid bacteria. More specifically, the present invention relates to a method for producing bread, which comprises selecting an alcohol-resistant strain from among lactic acid bacteria, allowing such lactic acid bacteria to exist in the dough, and ripening the dough.

(Problems to be solved by conventional technology and the invention) Bread is a dough made by kneading wheat flour as its main ingredient and auxiliary ingredients such as fats and oils, yeast, sugars, salt, dairy products such as skim milk powder, and water. It is produced by baking after going through a process of aging, but for factory production, there are many important factors such as the mechanical resistance of the dough, the internal and external texture (crust), the unique flavor of bread, and the preservation of the freshness of the product ( complex functions such as anti-aging) are required.

Various studies have been conducted regarding these characteristics, including the quality of the main and sub-ingredients, the influence of mechanical operations such as dough mixing, and differences in the aging process, and improvement methods have been found. Subtle changes in the quality of raw materials and aging conditions can lead to changes in the dough condition of bread products and variations in product quality, and the situation requires responses based on the experience of seasoned professionals. Industrially, various bread-making improvers have been developed, and for example, it is necessary to give physical properties necessary for mechanical production at the expense of some flavor characteristics.
New technological means are desired to meet the diversified consumer needs for more delicious breads. That is, there has been a desire for a method for industrially stably producing breads that have undergone the proper aging process and have a rich flavor.

2 belonging to the genus Satucharomyces, such as sour dough bread
More than one species of wild yeast, such as Satucharomyces equinugus, Satucharomyces curbacus, Satucharomyces chevalieri, etc., and Torula yeast, and lactic acid bacteria belonging to the Lactobacillus department, such as Lactobacillus plantarum, Lactobacillus plebis, and Lactobacillus spp. Fermentii, Lactobacillus casei, Lactobacillus bastrianus, etc., have been used for a long time mainly in Europe and the United States as a method to utilize the unique flavor produced by the collaboration with a group of bacteria (fine microorganisms). Technology based on experience is needed. Although there are reports suggesting that lactic acid bacteria normally contained in yeast are involved as a factor that affects the flavor of bread, no technology has been established to improve or control the flavor. Additionally, it has been known from experience that the flavor of breads differs slightly depending on the baker's yeast manufacturer, and that there are subtle variations in flavor even with the same type of baker's yeast, but the cause of these differences is clear. However, no effective improvement method has been found.

(Means and effects for solving the problem) The present inventors selected lactic acid bacteria that metabolize malic acid derived from wheat flour and increase the accumulation of lactic acid in yeast-containing dough, and used this lactic acid bacteria in breads. It was discovered that by using it in dough preparation, breads with excellent flavor as well as dough improvement effects can be obtained.
A patent application has already been filed. After that, we conducted a detailed study of these lactic acid bacteria, which have active metabolic ability in dough, and found that a common property of these lactic acid bacteria is ``alcohol tolerance,'' which allows them to grow in the presence of high concentrations of ethanol and exhibit their metabolic ability. I discovered that it has. Based on this knowledge, we selected strains that can grow in high concentrations of ethanol from among many lactic acid bacteria, and investigated the effect on the ripening of yeast-containing dough. On the other hand, strains that are not tolerant to alcohol may die in the dough or
It was found that it exerts almost no metabolic ability and has little effect on bread-making characteristics such as dough physical properties and flavor. That is, it has become possible to extremely efficiently select lactic acid bacteria that have the effect of improving bread production using "alcohol tolerance" as an index, and it has been discovered that such lactic acid bacteria can be used as a method for improving bread production, and the present invention completed.

Although it is known that alcohol-tolerant strains of baker's yeast (Saccharomyces cerevisiae) are used for bread production,
There is no known method for selecting alcohol-resistant strains of lactic acid bacteria and using them for bread production.

Although the details of the mechanism of the present invention are not clear,
It is known that relatively high concentrations of ethanol accumulate in yeast-containing dough, and while normal lactic acid bacteria's metabolism is suppressed by the presence of ethanol, alcohol-tolerant strains have weaker inhibition and are naturally unable to do so. It is thought that they are exerting their metabolic ability. However, it has been reported that lactic acid bacteria generally have stronger alcohol tolerance than other bacteria, and the amount of ethanol accumulated in dough is 1.0 to 2.
Since it is said to be about 0%, it seems that the general view was that the presence of alcohol did not have much of an effect. By analogy with the knowledge discovered by the present inventors, it is possible that during aging (fermentation) in a semi-solid dough, a high alcohol concentration may be partially reached, and that there is a possibility that the concentration of alcohol may be high in some parts of the dough. It is possible that the synergistic effect of the two causes a stronger inhibitory effect at low concentrations.

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

First, the alcohol-resistant lactic acid bacteria (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 at a yield of 50 times higher than that of carbohydrates.

Examples of lactic acid bacteria include strains belonging to the genus Lactobacillus, Leuconostoc, Streptococcus, and Pedeiococcus. It can also be isolated from natural products and foods such as dairy products, fruits, brewed foods, baker's yeast products, and cereals such as flour. Breeding strains of these lactic acid bacteria, such as mutation-treated strains and cell fusion strains, can also be used. Representative examples include Lactobacillus bulgaricus and Lactobacillus bulgaricus.
casei, Lactobacillus plebis, Lactobacillus casei
Fermentum, Leuconostoc oyanus, Streptococcus thermophilus, Pedeiococcus
Examples include Halophilus.

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

(1) Concentration of alcohol-resistant strains Grow lactic acid bacteria in a nutrient medium in advance, add ethanol to 5-1
10 to 10 cells/mI in a medium containing 2% by weight! Inoculate, 3
Enrichment culture is performed by statically culturing at 0 to 40°C, and when the bacteria grow, they are further planted in a medium containing ethanol and this operation is repeated.
Here are some ways to do it. It is preferable to gradually increase the ethanol concentration. In this process, the alcohol-resistant strain is concentrated, and finally, the diluted solution is spread on a solid medium (plate) containing 8 or more alcohols, cultured, and the grown colonies are harvested to obtain the alcohol-resistant strain. By adding calcium carbonate or a pH indicator to the plate medium, the lactic acid production ability can be checked at the same time. That is, around the lactic acid bacteria colony,
Organic acids (mainly lactic acid) accumulate and form a halo depending on the acid production capacity.

(11) Determination of alcohol tolerance concentration The following methods can be used to determine the alcohol tolerance of isolated and identified bacterial strains (ethanol was used as the alcohol, but propatool, butanol, isopropatool, isobutyl Alcohol etc. can also be used.

In this case, the criteria differ depending on the type of alcohol)
.

As usual, pre-culture was carried out in lactic acid bacteria nutrient medium, and the initial number of bacteria was 106 /
mI! Close, add preculture solution, and incubate at 25-37°C for 24 hours.
Cultivate for ~72 hours. 660 nm for 24.72 hours
Measure the turbidity of the medium and determine the growth curve at each concentration of ethanol.

Alcohol tolerance is determined when the OD value after 72 hours is 5 times or more than the initial value and the amount of lactic acid produced is 0.5 my/me or more in the medium.

Alcohol-resistant lactic acid bacteria that can be used in the present invention include strains with a resistant alcohol concentration of 8π or higher, preferably 11% or higher, such as Lactobacillus casei (Lactobacillus casei).
Lactobacillus casei) 6 B 1, Lactobacillus brev
is), Leuconostoc oenos
s) ATOO28279.

Methods for making the lactic acid bacteria selected by the method of the present invention exist in bread dough include a method of adding the lactic acid bacteria as a starter during dough kneading, a method of adding the lactic acid bacteria as a liquid seed,
Methods include mixing it with yeast products such as baker's yeast, using it as an emulsified oil composition by mixing it with the aqueous phase of oil and fat, and the old noodle method using a part of the fermented dough that is kept refrigerated. can give.

As a method of mixing with baker's yeast, commercially available baker's yeast (65
A culture solution of lactic acid bacteria is added to a milky yeast suspension in which moist bacterial cells containing ~75π water are dissolved in water, or to yeast milk in which bacterial cells have been washed after the culture step in the yeast manufacturing process, One example is vacuum filtration.

The resulting cake-like or granular wet bacterial cells are stored under refrigeration,
Although it is used in the production of breads, it can also be used as dry yeast by fluidized drying.

As a method for using it as an oil and fat composition, 10 to
Examples include emulsified oil and fat compositions containing 5 to 50 parts of lactic acid bacteria added at 10/mf, 95 to 50 parts of oil and fat, and 0.1 to 5 parts of emulsifier. A solution obtained by adding lactic acid bacteria to a solution obtained by treating wheat flour or active gluten with a yeast autolysis solution can also be used as the aqueous phase. This method is effective as a method for preparing an oil and fat composition at a low temperature of 30 to 40°C by utilizing the emulsifying power of processed wheat flour or activated gluten. It is also possible to add lactic acid bacteria to a flour suspension of 5 to 3 oπ and grow the lactic acid bacteria at a pH of -4 to 7, and then emulsify the mixture into an oil or fat composition.

The concentration of lactic acid bacteria in the dough is 10' to 109 pieces/i.
However, if the dough aging time is within 4 to 6 hours, it is preferably in the range of 105 to 109 pieces/g (dough), and for 8 hours or more as in low temperature long fermentation or cracker dough aging. 104 to 106 pieces/
It can be effective even at low concentrations of 1 dough).

The characteristics of the dough aging method of the present invention are as follows:
Dough p I (decreases quickly, and the ripening process progresses in a shorter time. Looking at the accumulation of organic acids in the dough, lactic acid bacteria actively utilize the substrate derived from wheat flour or auxiliary raw materials, and lactic acid accumulates from the early stage of ripening. A typical phenomenon is that malic acid derived from wheat flour is consumed, and a higher than normal concentration of lactic acid accumulates in the dough. Therefore, in organic acid analysis of baked products, malic acid When alcohol-resistant lactic acid bacteria are used according to the present invention, the malic acid content in bread products is lower than 25 m, 9, and lactic acid is 50 m, higher than 9. In other words, the method of the present invention can efficiently select bacterial cells that metabolize malic acid derived from wheat flour and increase the accumulation of lactic acid in yeast-containing dough, as previously discovered by the present inventors. was recognized.

The alcohol-tolerant lactic acid bacteria selected by the present invention not only have the characteristics of consuming malic acid and increasing lactic acid accumulation, but also have a characteristic metabolic process that is active in the dough, depending on the inherent metabolic ability of the lactic acid bacteria used. shows.

The breads referred to in the present invention include white bread, French bread,
Examples include breads such as British bread and pastries, biscuits, and crackers.

(Effect of the invention) Previously, attempts have been made to use lactic acid bacteria as a method for accelerating the ripening of bread dough or for the purpose of improving flavor. The reason why it could not be established as an effective technical means to control or improve bread quality is thought to be due to a lack of perspective on the influence of lactic acid bacteria on the alcohol produced by yeast.

The present invention makes it possible to control the -W product of organic acids during dough ripening, which was difficult to control with conventional methods, thereby improving important bread-making properties such as dough physical properties and flavor. This is the biggest advancement. Furthermore, an important advantage is that it is possible to efficiently select strains that have the effect of improving bread-making properties from among many lactic acid bacteria based on the index of "alcohol tolerance." For example, conventional methods require a great deal of effort and time to select a strain that exhibits the effect of improving bread production from a large number of strains obtained through breeding methods such as mutation treatment, but the method of the present invention requires a simple operation. This makes it possible to select excellent bacterial strains in a short period of time.

In addition to the above-mentioned effects, the present invention is highly effective in improving the flavor of breads as well as stabilizing and improving physical properties of dough such as mechanical resistance. It is also possible to shorten the dough maturation time. For example, when applied to straight bread, due to the action of lactic acid bacteria, lactic acid accumulates in the dough in a shorter time and I Since the physical properties of the dough can be obtained comparable to those of the dough (required), the characteristics of the straight method, which has excellent flavor and texture, can be applied to factory production.

(Example) The present invention will be explained below using examples.

Example 1 Among lactic acid bacteria, malic acid derived from wheat flour is consumed in bread dough containing yeast, and a significant amount of lactic acid is produced! Two strains: Lactobacillus casei (Lb.

casei) 6 B1, Lactobacillus plebis (Lb.

Lactobacillus acidophilus (Lb, acidophilus) K-85-Streptococcus lactis (8t, 1actis)
Alcohol tolerance was compared for KaO**, (currently distributed by the Faculty of Agriculture, Okayama University, future purchased from Christian Hansen, and the strain name was given by the inventor). Each lactic acid bacteria was cultured in a nutrient medium for lactic acid bacteria, and each strain was incubated at 80°C in a nutrient medium containing 5 to 11 parts of ethanol.
, static culture was performed for 72 hours, and the growth rate of lactic acid bacteria was 660.
The turbidity was compared in nm. The amount of lactic acid produced after the completion of the culture was measured using high-performance liquid chromatography (Shimadzu Corporation, LO
-6A type).

(Nutritional medium for lactic acid bacteria) Glucose 1 (1) Peptone 10I Yeast extract 5I Tween 80 1g L-cystine hydrochloride 0°1g Water 11p H6,8
~7.0 The obtained results are shown in FIG. 1 and Table 1.

As shown in Figure 1 and Table 1, the two strains that exhibit characteristic metabolic activity in bread dough grow in the presence of 8% or more alcohol, whereas general lactic acid bacteria do not grow in the presence of 8% or more ethanol. I know it can be suppressed. Since there is a difference in the growth rate even with 5% ethanol, it is suggested that if other components or metabolites are present in the dough, the expression of activity may be suppressed even in the range of 5 to 7%. The degree of production of lactic acid corresponds to the degree of growth of the bacteria, indicating that the alcohol tolerance of lactic acid bacteria can also be compared based on the degree of production of lactic acid in the presence of alcohol.

Example 2 An attempt was made to isolate lactic acid bacteria in yeast (commercially available baker's yeast).

That is, yeast was dissolved in water, diluted with sterilized physiological saline, and a lactic acid bacteria selective medium (1,100 pp of cycloheximide was added to suppress yeast growth, and 0.2 pp of cycloheximide was added for the purpose of checking lactic acid production ability). % of calcium carbonate) to perform flat (plate) culture, and collect strains that produce a halo of lysis around the colony.
Puncture culture was performed. Twenty strains were collected and used in Example 1.
The cells were inoculated into the nutrient medium for lactic acid bacteria shown in Figure 1, and cultured for 2 days at 30°C to form nutrient medium 1 for lactic acid bacteria containing 11% ethanol.
0mj? The cells were inoculated with o, t J7 and statically cultured at 30°C for 3 days. One of the 20 plants showed growth.

The obtained bacterial strain was plate cultured on an agar medium containing 8 parts of ethanol, and the growing strains were harvested and stored in a test tube medium (an agar medium containing 0.5.9 parts of calcium carbonate).

The mycological properties of the strains are shown in Table 2. As a result, it was identified as Lactobacillus casee e Koken Joyori No. 76-2).

Based on Example 1, the alcohol stiffness was examined and found to be 1
The change in turbidity at 660 nm for 72 hours in the ethanol-containing medium was 0.870, and the N bond of lactic acid (72
hr) 92 rrV/ml was detected, confirming alcohol tolerance.

Example 3 Using this method, we attempted a bread-making test using the medium-dough method.

When the amount of lactic acid bacteria mixed in the baker's yeast used was measured, it was found to be about 10 lactic acid bacteria/g (wet yeast cells). As in Example 2, when the alcohol tolerance of lactic acid bacteria was examined, no lactic acid bacteria that could grow in the presence of 8% or more alcohol was found.

This baker's yeast was used in the next bread making test.

Alcohol-resistant lactic acid bacteria were cultured in a nutrient medium for lactic acid bacteria, concentrated by centrifugation, and added (Dough ISI
equivalent to 10 pieces).

(Dough composition) Medium flour (strong flour) 70 parts Yeast food 01 parts Yeast (commercially available baker's yeast) 2.0 parts Water 40 parts Lactic acid bacteria solution
2 parts Honkneaded flour (strong flour) aO parts oil (shortening) 5 parts sugar
5 parts salt 2 parts skim milk powder 2 parts water 25 parts (operation) 1) Kneading conditions (medium kneading) Low speed 3 minutes, high speed 1 minute minutes, medium speed 1 minute, high speed 5 minutes 2) Kneading temperature 27-29℃ 3) Fermentation time Seeds 4 and a half hours bench time 20 minutes Incubation time 40-60 minutes (indicates the time to reach a certain volume) 4) Firing temperature FIG. 2 shows the results of measuring changes in organic acids during the bread making process at 180° C. for 35 minutes using high performance liquid chromatography. The bread making results are shown in Table 3.

Table 3 The dough condition and sensory evaluation of bread were evaluated by experts (
5 points) 5 Good 2 Slightly Poor 4 Slightly Good 1 Poor 3 Average As shown in Figure 2, when alcohol-resistant lactic acid bacteria are used, malic acid is consumed from the early stage of medium seed fermentation, and the accumulation of lactic acid is reduced. It is noteworthy that the

The lactic acid bacteria contained in the baker's yeast used were 106 in the dough.
Despite being at the same level as 100%, the accumulation of lactic acid is small, and almost no change is observed in malic acid.

As shown in Table 3, the bread-making characteristics were that the dough had excellent viscoelasticity and the dough condition in the molder was good. It was evaluated that the roasting time was shortened and the flavor was excellent.

Example 4 The lactic acid bacterium Lactobacillus casei obtained in Example 2 was treated with -3 (
Lactobacillus casei strain 6B1 shown in Example 1 was cultured in a nutrient medium and concentrated by centrifugation, and commercially available baker's yeast was suspended in water. (concentration of wet bacterial cells 60%) and vacuum permeation to obtain baker's yeast wet bacterial cells Ig containing 70% water content.
Each time, a cake-like yeast cell containing 10 lactic acid bacteria was prepared. 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 Shortening 5 parts Yeast 2.5 parts Yeast food 0.1 part Skim milk powder
2 parts water 69 parts (Procedure) Mix all ingredients except shortening, mix on low speed for 2 minutes, then on medium speed for 1 minute.
minutes, knead on high speed for 5 minutes, add shortening, then knead on low speed for 1 minute, medium speed for 1 minute, and high speed for 5 minutes, raise the temperature to 28℃, ferment at 30℃ for 1 hour, punch, and ferment for another 30 minutes. continued. Subsequently, the mixture was divided, rounded, rolled, and molded using a molder, and then subjected to foil fermentation at 30° C. and 80% humidity.

After the proofing was completed (until the case reached a level of 1.5 cm), firing was performed. The bread making results are shown in Table 4.

Table 4 [- ■ [Example 5] In order to examine the differences between the bread produced by the method of the present invention and commercially available bread, analysis of organic acids in the internal phase (crumb) of 10 types of bread was attempted. In other words, the internal aspects of bread 10.
9 was taken, water aomz was added, and after homogenization, the supernatant obtained by centrifugation was filtered, and the F solution was subjected to high performance liquid chromatography to examine the organic acid content.

The results obtained are shown in Table 5.

Table 5 Rice Although it varies depending on the amount of alcohol-resistant lactic acid bacteria added to the dough, dough fermentation conditions, and split bread method (for example, straight method, dough method), typical examples are shown.

As shown in Table 5, examples of the characteristics of the present invention include low malic acid content and very high lactic acid content. Since the amount of lactic acid increases compared to the amount of malic acid consumed, lactic acid is accumulated using the metabolites provided by yeast and components derived from the main and sub-raw materials of dough, such as wheat flour and skim milk powder, as substrates. It is also possible that there are.

[Brief explanation of the drawing]

Figure 1 is a graph showing the alcohol tolerance of lactic acid bacteria tested in a medium containing 5% ethanol, 8 and 11, and Figure 2 is a graph showing the alcohol tolerance of lactic acid bacteria during the bread making process using the alcohol tolerant lactic acid bacteria obtained in Example 2. It is a graph showing changes in major organic acids. Patent applicant Makoto Asano, agent of Kanebuchi Chemical Industry Co., Ltd. −

Claims (6)

[Claims] (1) A method for producing bread, which comprises selecting an alcohol-resistant strain from among lactic acid bacteria and ripening the dough using one or more of the lactic acid bacteria. (2) The production method according to claim 1, wherein the lactic acid bacteria are alcohol-resistant lactic acid bacteria that can grow and produce lactic acid in the presence of 11% or more ethanol. (3) The production method according to claim 1, wherein the lactic acid bacteria is a strain selected from strains belonging to the genus Lactobacillus and the genus Leuconostoccus. (4) 10% of lactic acid bacteria resistant to real alcohol per gram
2. The manufacturing method according to claim 1, wherein compressed baker's yeast, dry yeast, or products of these baker's yeast containing 4 to 10^9 are used in bread dough. (5) The content of malic acid and lactic acid in bread products is
Breads characterized by containing 25 mg% or less and 50 mg% or more, respectively. (6) Contain alcohol-resistant lactic acid bacteria at 10% per 1g.
Bread dough containing ^4 to 10^9 pieces/g.