JP2020191812A - Bread quality improving agent, method of improving quality of bread, and method of producing bread - Google Patents

Abstract

To provide a bread quality improving agent capable of improving stability of laminated dough, and making excellent appearance such as an internal phase of bread to be produced, and food texture such as a crunchy feeling and a melt-in-the-mouth feeling, a method of improving quality of bread, and a method of producing bread, the method of producing bread comprising a cooling step in a preparing step of bread dough, the bread obtained by using layered dough in which bread dough and oil and fat, and various types of cream are superposed, in particular, laminated bread dough.SOLUTION: There is provided a bread quality improving agent containing α-glucosyltransferase and branched cyclic dextrin, a method of improving quality of bread using the bread quality improving agent, and a method of producing bread.SELECTED DRAWING: None

Description

The present invention relates to a quality improver for breads suitable for breads using a laminated dough in which bread dough, oils and fats, various creams, etc. are layered, a method for improving the quality of breads using the quality improver for breads, and breads. Regarding the manufacturing method.

Among breads, for example, Danish pastry, croissants, pies, pastries, millefeuilles, etc. are produced using a laminated dough in which bread dough, fats and oils, various creams, and the like are laminated.

During manufacturing, it is unlikely to occur in small-scale manufacturing facilities such as retail bakeries, but in relatively large-scale manufacturing facilities such as bakeries, the amount of bread dough handled is large, so after the floor time ends, all of the bread dough There will be a time lag before it is divided. As a result, the bread dough shrinks, and breads manufactured using laminated dough cannot fold oils and fats neatly. As a result, the appearance and texture of the volume and internal phase vary. There is a problem that occurs. This problem is particularly likely to occur when the retard manufacturing method, which is a manufacturing method in which fermentation of dough is suppressed or delayed by placing it in a refrigerator after performing fermentation for a short time, is used.

So far, various techniques for improving the quality of breads and the like have been proposed. For example, as a quality improving agent for improving the volume and texture of breads, 6-α-glucanotransferase has been modified. Bread quality improver containing gluten (for example, see Patent Document 1) and bread quality improver containing at least one proteolytic enzyme selected from the group consisting of glutaminase and exopeptidase (for example, patent). (Refer to Reference 2), an effective amount of branching enzyme as a bread-modifying or do-modifying composition that increases the volume of baking products, improves freshness, improves structure and softness, and improves the quality of sensory stimulation. Bread-modified or do-modified compositions containing (see, for example, Patent Document 3) have been proposed.

Further, as a technique for improving the quality of food using an enzyme, for example, a technique for suppressing aging of rice cakes or noodles using maltotriosyltransferase (see, for example, Patent Document 4) has been proposed. ..

Further, the branched cyclic dextrin which can be produced by a method of allowing blanching enzyme and 4-α-glucanotransferase to act on the branched glucan which is a substrate (see, for example, Patent Document 5) is an energy material and powdered. It is used as a base material, quality improver, taste improver, etc.

However, in a method for producing breads that uses a laminated dough in which bread dough is laminated with oils and fats, various creams, etc., particularly a laminated bread dough that has a refrigerating process in the bread dough preparation process, the stability of the laminated dough is improved. As a technology that can improve the appearance of the internal phase of the bread to be manufactured and the texture such as crispness and melting in the mouth, no satisfactory one has been provided yet, and prompt provision is strongly required. The current situation is that it is being done.

JP-A-2017-143747 JP-A-2017-143746 Special Table 2000-513568 Gazette International Publication No. 2012/105532 Japanese Unexamined Patent Publication No. 2012-120471

An object of the present invention is to meet such a demand, break through the current situation, solve the above-mentioned problems in the past, and achieve the following objects. That is, the present invention uses a laminated dough in which bread dough, fats and oils, various creams, etc. are laminated, particularly in a method for producing breads using laminated bread dough and having a refrigeration step in the bread dough preparation process, the stability of the laminated dough. A quality improver for breads, a method for improving the quality of breads, and a method for manufacturing breads, which can improve the appearance of the internal phase of the breads to be manufactured and the texture such as crispness and melting in the mouth. The purpose is to provide.

As a result of diligent studies to achieve the above object, the present inventors improved the stability of the laminated dough by adding and blending α-glucosyltransferase and branched cyclic dextrin at the time of producing bread dough. It was found that the appearance of the internal phase of breads and the texture such as crispness and melting in the mouth can be improved.

The present invention is based on the above-mentioned findings of the present inventors, and the means for solving the above-mentioned problems are as follows. That is,
<1> A quality improver for breads, which comprises α-glucosyltransferase and branched cyclic dextrin.
<2> The quality improver for breads according to <1>, which is used in α-glucosyltransferase 3 to 100U with respect to 100 g of a flour raw material mainly composed of wheat flour.
<3> The quality improver for breads according to <1> or <2>, which is used in 0.03 to 1.5 g of branched cyclic dextrin with respect to 100 g of a flour raw material mainly composed of wheat flour.
<4> The breads according to any one of <1> to <3> above, which further contain α-amylase and the amount used thereof is 2 to 100 U with respect to 100 g of a flour raw material mainly composed of wheat flour. It is a quality improver.
<5> The quality improver for breads according to <4>, wherein the compounding ratio of α-glucosyltransferase and α-amylase is in the range of 1: 5 to 5: 1.
<6> The quality improver for breads according to any one of <1> to <5>, which further contains ascorbic acid or a salt thereof and / or cysteine or a salt thereof.
<7> A method for improving the quality of breads, which comprises using the quality improving agent for breads according to any one of <1> to <6>.
<8> A method for producing breads, which comprises using the quality improver for breads according to any one of <1> to <6>.

According to the present invention, the above-mentioned problems in the prior art can be solved, and bread having a refrigerating step in the bread dough preparation process using a laminated dough in which bread dough, fats and oils, various creams, etc. are laminated, particularly using laminated bread dough. Bread, a quality improver for bread, which can improve the stability of laminated dough and improve the appearance of the internal phase of the bread to be produced and the texture such as crispness and melting in the mouth. It is possible to provide a method for improving the quality of breads and a method for producing breads.

(Quality improver for breads)
The quality improver for breads of the present invention contains at least α-glucosyltransferase and branched cyclic dextrin, and further contains other components as necessary.

<Breads>
The breads (including confectionery) in the present invention are not particularly limited and may be appropriately selected, but breads produced by using a laminated dough in which bread dough, fats and oils, various creams and the like are laminated are preferable. In particular, breads that use laminated bread dough and have a refrigerating step in the bread dough preparation step are preferably mentioned. Specific examples of such breads include Danish pastry, croissants, pies, pastries, millefeuilles and the like.

<Α-Glucosyltransferase>
The α-glucosyl transferase is an enzyme that transfers a part of 1,4-α-glucan to another part of a hydrocarbon such as glucose or 1,4-α-D-glucan.
The α-glucosyltransferase is not particularly limited as long as it can be used for food and drink (grade), and can be appropriately selected. However, the α-glucosyltransferase described in International Publication No. 2012/105532 (1). Malttriosyltransferase) is preferred. As the α-glucosyltransferase, a commercially available product can be appropriately used.
The content of the α-glucosyltransferase in the quality improver for breads is not particularly limited and may be appropriately selected depending on the amount used, the activity and the like.

<Branched ring dextrin>
The branched cyclic dextrin (sometimes referred to as "highly branched cyclic dextrin") is a dextrin having a cyclic structure in which a large number of glucoses are branched and linked, and in detail, glucose is α-1,4 glycoside. It is a dextrin that is further branched by α-1,6 glycosidic bond to the amylopectin chain bound by binding and has one cyclic structure in the molecule. The branched cyclic dextrin is produced by allowing an enzyme to act on starch (amylopectin).
On the other hand, cyclodextrin is a cyclic oligosaccharide in which glucose is bound by an α-1,4 glycosidic bond to form a cyclic structure, and is a substance completely different from the branched cyclic dextrin in the present invention.
The branched cyclic dextrin is not particularly limited as long as it can be used for food and drink (grade), and can be appropriately selected. For example, a commercially available product such as cluster dextrin of Glico Foods Co., Ltd. is appropriately used. can do.
The content of the branched cyclic dextrin in the quality improver for breads is not particularly limited and may be appropriately selected depending on the amount used and the like.

<Other ingredients>
The other components are not particularly limited and may be appropriately selected as long as the effects of the present invention are not impaired. For example, α-amylase; ascorbic acid or a salt thereof and / or cysteine or a salt thereof; gluten or the like. Examples include food materials. These may be used alone or in combination of two or more.
Among these, it is preferable to contain α-amylase in order to further improve the appearance and texture of the internal phase of the bread to be produced.
Further, in order to further improve the stability of the bread dough and the appearance and texture of the internal phase of the bread to be produced, it is preferable to contain ascorbic acid or a salt thereof and / or cysteine or a salt thereof.
The content of the other components in the quality improver for breads is not particularly limited and may be appropriately selected.

<< α-Amylase >>
The α-amylase is not particularly limited as long as it can be used for food and drink (grade), and can be appropriately selected.
The type of the α-amylase is not particularly limited and may be appropriately selected. For example, the genus Aspergius such as Aspergillus oryzae, Bacillus subtilis, Bacillus amyloliquefaciens ( Examples include α-amylase derived from microorganisms such as Bacillus amyloliquefaciens, Bacillus licheniformis, and Streptomyces, and α-amylase derived from grains such as barley and wheat. These may be used alone or in combination of two or more.
As the α-amylase, commercially available products such as Biozyme A of Amano Enzyme Co., Ltd. and Sumiteam AS of Shin Nihon Kagaku Kogyo Co., Ltd. can be appropriately used.
The content of the α-amylase in the quality improver for breads is not particularly limited and may be appropriately selected depending on the amount used, the activity and the like.

<< Ascorbic acid or its salt and / or cysteine or its salt >>
The ascorbic acid or a salt thereof and cysteine or a salt thereof are not particularly limited as long as they can be used for food and drink (grade), and commercially available products can be appropriately selected.
As the ascorbic acid or a salt thereof and cysteine or a salt thereof, either one may be used, or both may be used.
The salt is not particularly limited and may be appropriately selected. For example, a salt with an alkali metal such as sodium or potassium, a salt with an alkaline earth metal such as calcium or magnesium, hydrochloric acid, sulfuric acid, phosphoric acid, etc. Examples thereof include salts with inorganic acids such as nitric acid and hydrobromic acid. As the salt, one kind of salt may be used, or two or more kinds of salts may be used in combination.
The content of the ascorbic acid or a salt thereof and / or cysteine or a salt thereof in the quality improver for breads is not particularly limited and may be appropriately selected depending on the amount used and the like.

<Aspect>
The quality improver for breads may contain the α-glucosyltransferase, the branched cyclic dextrin, and, if necessary, the other components in the same packaging material, or may contain the above-mentioned components. One or more of them may be put into separate packaging materials, and each component may be mixed and added to the flour raw material at the time of use, or each component may be added to the flour raw material.

<Usage>
The amount of the quality improver for breads used is not particularly limited, and can be appropriately selected according to the amount of each component to be used, which will be described later.

<< α-Glucosyltransferase >>
The amount of the α-glucosyltransferase used is not particularly limited and may be appropriately selected, but it may be selected as appropriate with respect to 100 g of a flour raw material mainly composed of wheat flour (hereinafter, may be simply referred to as “flour raw material”). , Usually 3 to 100 U (“U” represents an active unit (unit); the same applies hereinafter), preferably 5 to 90 U, and more preferably 15 to 60 U. If the amount of the α-glucosyltransferase used is less than 3U, it may not be possible to impart sufficient stability to the bread dough, and it may not be possible to sufficiently impart a good appearance and texture to the bread, 100U. Even if it is blended in excess of, the effect produced does not increase.

In the present invention, the definition of the active unit of α-glucosyltransferase is that the amount of enzyme that produces 1 μmol of glucose in 2.5 mL of the reaction solution per minute under the following conditions is 1 U.
-Conditions-
Add 0.5 mL of the enzyme solution to 2 mL of 10 mmol / L MES buffer (pH 6.5) containing 1% maltotetraose and leave at 40 ° C. for 60 minutes. After standing, it is heated in a boiling water bath for 5 minutes and then cooled in running water to quantify the glucose produced.

<< Branched ring dextrin >>
The amount of the branched cyclic dextrin to be used is not particularly limited and may be appropriately selected, but is usually 0.03 to 1.5 g with respect to 100 g of the flour raw material mainly composed of wheat flour, and is 0.05 to 0.05. It is preferably 1.0 g, more preferably 0.1 to 0.6 g. If the amount of the branched cyclic dextrin used is less than 0.03 g, it may not be possible to impart sufficient stability to the bread dough, and it may not be possible to sufficiently impart a good appearance and texture to the bread. If it exceeds 1.5 g, not only the effect to be played is not improved, but also the extensibility of the refrigerated laminated dough is lowered, and the flavor may be lowered.

<< α-Amylase >>
The amount of α-amylase used is not particularly limited and may be appropriately selected, but is preferably 2 to 100 U with respect to 100 g of a flour raw material mainly composed of wheat flour. It is more preferably 70 U, and particularly preferably 10 to 50 U. If the amount of α-amylase used is less than 2U, a sufficient addition effect may not be obtained, and if it exceeds 100U, the stability of the refrigerated laminated dough may be adversely affected.

In the present invention, the definition of the active unit of α-amylase is that starch is used as a substrate and reacted at pH 5.0 and 30 ° C. for 25 minutes and then colored with iodine, and the conversion rate of soluble starch at absorbance (620 nm). The amount of enzyme, which is 1.0 g per hour, is 1 U.

<< Combination ratio of α-glucosyltransferase and α-amylase >>
The compounding ratio of the α-glucosyltransferase and the α-amylase is not particularly limited and may be appropriately selected, but the ratio of active units is preferably in the range of 1: 5 to 5: 1. More preferably, it is in the range of 2: 2 to 3: 1. When the blending ratio is within a preferable range, it is advantageous in that the stability of the bread dough and the appearance and texture of the obtained bread are better.

<< Ascorbic acid or its salt and / or cysteine or its salt >>
The total amount of ascorbic acid or a salt thereof and / or cysteine or a salt thereof when used is not particularly limited and may be appropriately selected, but is 0 with respect to 100 g of a flour raw material mainly composed of wheat flour. .1 to 50 mg is preferable, and 1 to 5 mg is more preferable. When the total amount of ascorbic acid or a salt thereof and / or cysteine or a salt thereof is within a preferable range, it is advantageous in that the stability of the bread dough and the appearance and texture of the produced bread are further improved. ..

<Flour raw material mainly made of wheat flour>
The flour raw material mainly containing wheat flour mainly contains wheat flour such as strong flour, semi-strong flour, medium-strength flour, and durum wheat flour, and may be a combination of these various flours. Further, whole grain flour may be used as the wheat flour, but in this case, the wheat bran portion contained in the whole grain flour is converted as bran. In addition to wheat flour, the flour may contain barley flour, rye flour, rye flour, buckwheat flour, rice flour, and oat flour.

(Bread manufacturing method)
In the method for producing breads of the present invention, at least the quality improver for breads of the present invention is used in the process of producing breads, and other components are further used as necessary.

As a method for producing breads, a production method using a laminated dough in which bread dough, fats and oils, various creams and the like are laminated and folded is preferably mentioned, and a method in which a refrigerating (retard) step is provided in the bread dough preparation process is more preferable. Listed in.
The refrigerating process of bread dough may be set at any stage after the bread dough is produced by mixing and kneading flour raw materials mainly composed of flour with yeast, salt, water and other raw materials. For example, floor time. After, before, during, and after the folding process, after molding, and the like. Other than this, there are methods of fermentation, molding, and firing in a normal procedure.

The method for producing bread includes the steps of mixing and kneading water, yeast (raw yeast, dry yeast, etc.), fats and oils, and other bread-making raw materials as desired in the above-mentioned flour raw materials, but other bread-making raw materials. Usually used in the production of breads, for example, various fermented species such as sour and levin; yeast food; sugars such as sugar, glucose, fructose, converted sugar, water candy, malt sugar, lactose; eggs or egg flour. Dairy products such as defatted milk powder, whole fat powder, cheese powder, yogurt powder, whey powder; fats and oils such as shortening, butter, margarine and other animal and vegetable oils; emulsifiers; leavening agents; thickeners; sweeteners; fragrances; Colorants; ascorbic acid; inorganic salts such as salt; enzymes such as glucosidase, glucose oxidase, lipase, hemicellulase; dietary fiber can be appropriately used.

<Usage>
The amount of the quality improver for breads of the present invention used in the method for producing breads is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected. For example, the above-mentioned invention of the present invention. The amount can be the amount described in the <Usage amount> item of (Quality improver for breads).
The quality improver for breads is usually added and blended during the production of bread dough.

(How to improve the quality of bread)
In the bread quality improving method of the present invention, at least the bread quality improving agent of the present invention is used in the bread manufacturing process, and other components are further used as necessary.
The method for improving the quality of breads can be carried out in the same manner as the method for producing breads of the present invention described above.

According to the bread dough quality improving agent, the bread manufacturing method, and the bread quality improving method of the present invention, a laminated dough in which bread dough is laminated with oils and fats, various creams, etc. is used, and in particular, a laminated bread dough is used. In the method for producing breads having a refrigeration process in the preparation process, it is possible to improve the stability of the laminated dough and improve the appearance of the internal phase of the produced breads and the texture such as crispness and melting in the mouth. it can.

Hereinafter, the present invention will be described with reference to Production Examples, Comparative Production Examples, and Test Examples, but the present invention is not limited thereto.

(Production Example 1, Comparative Production Examples 1 to 4: Production of Quality Improver for Various Breads)
The quality improvers for breads of Production Examples 1 and Comparative Production Examples 1 to 4 were produced by the formulation shown in Table 1 below. The amount of the food material (gluten) was appropriately changed for each bread quality improver, and the total amount was adjusted to 1.0 g. In addition, a food material (gluten) was prepared as a control.
The details of the components used are as follows.
・ Α-Glucosyl transferase: product name “Amano L”, manufactured by Amano Enzyme Co., Ltd. ・ α-Amylase: product name “Biozyme A”, manufactured by Amano Enzyme Co., Ltd. ・ Branched cyclic dextrin: product name “cluster dextrin”, glyconutrient food Made by Co., Ltd.

(Test Example 1: Production of croissants)
Croissants were produced by the following formulation and process using the above-mentioned Production Examples 1 and Comparative Production Examples 1 to 4 or the control quality improver for breads.
<Mixing>
・ 100 parts by mass of strong flour ・ 5.0 parts by mass of raw yeast ・ 1.0 parts by mass of quality improver for bread ・ 10.0 parts by mass of sugar ・ 1.8 parts by mass of salt ・ 8.0 parts by mass of shortening ・ 50 parts of water. 0 parts by mass [* Roll-in fat (margarine) 25.0 parts by mass (against dough)]
<Process>
・ Mixing ↓ (oils and fats) Low speed 3 minutes Medium speed 2 minutes ・ Kneading temperature 21 ℃
・ Floor time 30 minutes ・ Retard condition 0 ℃ / 20 hours ・ Folding condition 3 folds / 3 times ・ Divided weight 60g
・ Molding Croissant molding ・ Hoiro time 70 minutes (32 ℃, humidity 85%)
-Baking conditions 200 ° C, 14 minutes

<Evaluation>
In the above step, the physical properties and conditions of the laminated fabric after folding were evaluated according to the following evaluation criteria "fabric stability (stretchability and physical property stability)". In addition, the appearance (internal phase of bread) and texture (crispness, melting in the mouth) of the produced croissants were also evaluated by 10 people according to the following evaluation criteria. The average score of the obtained results is shown in Table 2 below.

-Fabric stability (extensibleness and physical property stability)-
5 points: Excellent extensibility, no shrinkage of the fabric after folding.
4 points: It is extensible and there is almost no shrinkage of the fabric after folding.
3 points: There is some extensibility, there is little shrinkage of the fabric after folding, or the extensibility becomes a little excessive, and a slight stickiness occurs.
2 points: Slightly inferior in extensibility, some shrinkage of the dough after folding, or excessive extensibility of the dough, resulting in some stickiness.
1 point: Poor extensibility, the dough shrinks after folding, or the dough becomes excessively extensable, resulting in excessive stickiness.

-Appearance (internal phase of bread)-
5 points: It is a thin and uniform layer, and is an internal phase with a clear laminated structure.
4 points: The film is thin and slightly uniform, and it is the internal phase of the laminated structure.
3 points: The internal phase of the laminated structure is slightly non-uniform, although the film is slightly thin.
2 points: Internal phase in which the film thickness is non-uniform and the laminated structure is partially crushed.
1 point: The internal phase is uneven in film thickness and the laminated structure is totally crushed.

-Texture (crisp, melted in the mouth)-
5 points: Excellent for both crispness and melting in the mouth.
4 points: Crisp and melts in the mouth 3 points: Slightly crisp and melts in the mouth.
2 points: There is some play and there is some dryness.
1 point: There is play and there is dryness.

As shown in Table 2, when the preparation of Production Example 1, which is an example of the preparation of the present invention, is used, the dough is stable and the produced breads have a good appearance and texture. confirmed.

(Test Example 2)
<Manufacturing of quality improvers for various breads>
The amount of each component used when the amount of the quality improver for breads is added to 100 g of the flour raw material (strong flour in this test example) mainly composed of wheat flour is shown in Table 3 below. The amount of the food material (gluten) was appropriately changed so that the total amount was 1.0 g, and Test Examples 2-1 to 2-4 and the control quality improver for breads were produced. did.
In addition, the amount of each component used when the amount of the quality improver for breads shown in Table 3 below is added to 100 g of the flour raw material (strong flour in this test example) mainly composed of wheat flour is shown in Table 3 below. The amount of the food material (gluten) was appropriately changed so as to be the amount described in the above, and the total amount was 2.0 g (Test Example 2-5), 3.0 g (Test Example 2-6) or 4.0 g (Test). Various quality improvers for breads were prepared so as to be in Example 2-7).

<Manufacturing of croissants>
A croissant was produced by the formulation and process of Test Example 1 using Test Examples 2-1 to 2-7 or a control quality improver for breads produced above. However, the blending amount of the quality improver for breads was changed to the amount shown in Table 3 below.
In addition, the physical properties and condition of the laminated dough, the appearance (internal phase of bread) and texture (crispness, melting in the mouth) of the produced croissant were evaluated according to the same evaluation criteria as in Test Example 1. The results obtained are shown in Table 3 below.

As shown in Table 3, it was confirmed that the effect of the present invention can be obtained even when the amounts of α-glucosyltransferase and branched cyclic dextrin are changed.

(Test Example 3)
<Manufacturing of quality improvers for various breads>
Test Examples 3-1 to 3-5 and control quality improvers for breads were produced by the formulation shown in Table 4 below. The amount of the food material (gluten) of each bread quality improver was adjusted as appropriate so that the total amount was 1.0 g.

<Manufacturing of croissants>
A croissant was produced by the compounding and process of Test Example 1 using Test Examples 3-1 to 3-5 or a control quality improver for breads produced above.
In addition, the physical properties and condition of the laminated dough, the appearance (internal phase of bread) and texture (crispness, melting in the mouth) of the produced croissant were evaluated according to the same evaluation criteria as in Test Example 1. The results obtained are shown in Table 4 below.

As shown in Table 4, it was confirmed that the effect of the present invention can be obtained even when the compounding ratio of α-glucosyltransferase and α-amylase or the compounding amount of α-amylase is changed. It was also confirmed that an excellent effect can be obtained by using L-cysteine or a salt thereof.

According to the quality improver for breads of the present invention, in the method for producing breads using laminated dough, the stability of the laminated dough is improved, the appearance of the internal phase of the produced bread, and the food such as crispness and melting in the mouth. Since the feeling can be made good, the laminated bread dough can be used and can be suitably used for breads having a refrigerating step in the bread dough preparation step. Therefore, the quality improver for breads of the present invention is carried out as described above. Not limited to the breads described in the example items, it can also be suitably used for breads such as denish, pie, pastry, and millfille.

Claims (8)

A quality improver for breads, which comprises α-glucosyltransferase and branched cyclic dextrin. The quality improver for breads according to claim 1, which is used in α-glucosyltransferase 3 to 100U with respect to 100 g of a flour raw material mainly composed of wheat flour. The quality improver for breads according to claim 1 or 2, which is used in 0.03 to 1.5 g of branched cyclic dextrin with respect to 100 g of a flour raw material mainly composed of wheat flour. The quality improver for breads according to any one of claims 1 to 3, further containing α-amylase and using 2 to 100 U with respect to 100 g of a flour raw material mainly composed of wheat flour. The quality improver for breads according to claim 4, wherein the compounding ratio of α-glucosyltransferase and α-amylase is in the range of 1: 5 to 5: 1. The quality improver for breads according to any one of claims 1 to 5, further comprising ascorbic acid or a salt thereof and / or cysteine or a salt thereof. A method for improving the quality of breads, which comprises using the quality improving agent for breads according to any one of claims 1 to 6. A method for producing bread, which comprises using the quality improver for bread according to any one of claims 1 to 6.