Bread having high protein content and containing acetic acid

Abstract

The present disclosure addresses the problem of providing bread which contains 30 mass% or more of protein based on dry mass and acetic acid, and has less sourness and less acid smell.　The bread is obtained from dough containing: 30 mass% or more of protein per dry mass of the dough; acetic acid; and amylase.

Description

High protein bread containing acetic acid

[0001] The present disclosure relates to bread containing 30% by mass or more of protein and acetic acid on a dry mass basis and having reduced sourness and sour odor. The present disclosure also relates to a bread mix flour used to make the bread, and a method for making the bread.

[0002] In recent years, people have become more health conscious as the times progress, and protein is one of the nutrients that people are most consciously consuming. On the other hand, bread has become a staple food or snack in the diet, so increasing the protein content of bread is effective for efficient protein intake. Various techniques for producing bread with an increased protein content have been reported (Patent Documents 1 and 2, etc.).

[0003] On the other hand, while the shelf life of ordinary bread is about 3 to 5 days, demand for long-life bread, which has a longer shelf life of about 14 to 60 days, is increasing as a staple food, preserved food, emergency food, etc. Long-life bread is sometimes blended with organic acids such as acetic acid to impart bacteriostatic properties and improve shelf life.

[0004] JP 2023-42298 A JP 2020-103200 A

[0005] Bread containing 30% or more by weight of protein and acetic acid on a dry weight basis is beneficial in terms of nutritional value and shelf life, but has the disadvantage that it produces a sour taste and sour odor due to the acetic acid, and does not fully retain the original flavor of bread.

[0006] Therefore, an object of the present disclosure is to provide bread that contains 30% or more by mass of protein and acetic acid in terms of dry mass and has reduced sourness and sour odor.

[0007] The inventors conducted extensive research to solve the above-mentioned problems and found that bread made from dough containing 30% or more protein (on a dry weight basis), acetic acid, and amylase, which has a high protein content and improved shelf life, can suppress the sour taste and sour odor caused by acetic acid. Furthermore, while the addition of whole wheat flour to increase protein content and nutritional value has traditionally been associated with the drawback of producing a bran or soybean-like odor, the inventors found that the bran or soybean-like odor can be suppressed in the bread made from whole wheat flour. Furthermore, the addition of soy flour to increase protein content and nutritional value has traditionally been associated with the drawback of producing a bean-like odor. The inventors found that the bean-like odor can be suppressed in the bread made from dough by adjusting the amount of amylase added. Furthermore, the inventors have found that bread having the above-mentioned characteristics has a saccharide molecular weight distribution measured under specified conditions in which the ratio of saccharides with a molecular weight of 1,000 to 3,000 to the total amount of carbohydrates is 23% or less, and the ratio of saccharides with a molecular weight of less than 1,000 is 57% or more. The present disclosure has been completed through further investigation based on these findings.

[0008] That is, the present disclosure provides the following aspects of the invention. Item 1. Bread obtained from dough containing 30% by mass or more of protein per dry mass of the dough, acetic acid, and amylase. Item 2. The bread according to Item 1, wherein the dough contains whole wheat flour and / or soy flour. Item 3. The bread according to Item 1 or 2, wherein the amylase is α-amylase. Item 4. A bread mix containing 30% by mass or more of protein, acetic acid, and amylase. Item 5. A method for producing bread, comprising the steps of adding water to the bread mix according to Item 4 to prepare dough, and fermenting and baking the dough obtained in the step. Item 6. Bread made from dough containing 30% or more protein by weight per dry weight of the dough and acetic acid, wherein the sugar molecular weight distribution measured under the following conditions is such that the ratio of sugars with a molecular weight of 1,000 to less than 3,000 is 23% or less and the ratio of sugars with a molecular weight less than 1,000 is 57% or more relative to the total sugars. <Conditions for measuring sugar molecular weight distribution> (1) 0.05 g of bread is shredded, 10 mL of 0.1 mol / L sodium nitrate solution is added, and the mixture is left at room temperature overnight, after which it is filtered through a membrane filter. (2) The resulting filtrate is subjected to HPLC using a size exclusion column to obtain a chromatogram. The molecular weight of each peak is determined from a calibration curve prepared using pullulan and maltotriose of known molecular weights as standards. (3) The peak area of ​​the molecular weight of 1,000 to less than 3,000 relative to the total peak area is calculated as the ratio of sugars with a molecular weight of 1,000 to less than 3,000 relative to the total sugars. Furthermore, the peak area of ​​a molecule having a molecular weight of less than 1,000 relative to the total peak area is calculated as the ratio of the molecule having a molecular weight of less than 1,000 relative to the total amount of the molecule.

[0009] According to the bread of the present disclosure, the bread contains a high content of protein and acetic acid, and can suppress the sour taste and sour odor caused by acetic acid. Furthermore, according to one embodiment of the bread of the present disclosure, even though it contains whole wheat flour, the bran and soybean pulp odor caused by the whole wheat flour can be suppressed. Furthermore, according to another embodiment of the present disclosure, even though it contains soy flour, the beany odor caused by the whole wheat flour can be suppressed. In one embodiment of the bread of the present disclosure, the acetic acid not only improves shelf life but also makes it easier to use soybeans, making it possible to provide long-life bread containing soybeans, which can contribute to achieving the goals of SDG 2 "End hunger, achieve food security and improved nutrition, and promote sustainable agriculture" and SDG 9 "Build resilient infrastructure, promote industry, innovation and infrastructure."

[0010] 1. Definitions It should be understood that the terms used in this disclosure are used in the sense commonly used in the art unless otherwise specified. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0011] In the present disclosure, the content of each ingredient or raw material in bread is the content of each ingredient or raw material when the bread is converted to dry mass, and is the ratio of the content of each ingredient or raw material to the total amount of ingredients other than water contained in the bread. Also, in the present disclosure, the content of each ingredient or raw material in bread is calculated as the ratio of the dry mass of each ingredient or raw material contained in the dough to the dry mass of the dough used to make the bread (the total mass excluding water).

[0012] In the present disclosure, the content of each component or ingredient contained in the bread flour mix is ​​the content of each component or ingredient when the bread flour mix is ​​converted to dry mass, and is the ratio of the dry mass of each component or ingredient to the total amount of components other than water contained in the bread flour mix.

[0013] 2. Bread (Part 1) One embodiment of the bread of the present disclosure is bread obtained from dough containing 30% by mass or more of protein per dry mass of the dough, acetic acid, and amylase. The bread of the present disclosure is described in detail below.

[0014] [Protein] The bread of the present disclosure is obtained from dough containing 30% by mass or more of protein based on the dry mass of the dough. In the present disclosure, the protein content in the dough is the total amount of protein contained in the ingredients that serve as protein sources among the ingredients contained in the dough.

[0015] The type of protein used in the present disclosure is not particularly limited, but examples include wheat protein, soy protein, egg protein, milk protein, rice protein, pea protein, corn protein, barley protein, rye protein, etc. These proteins may be used alone or in combination of two or more.

[0016] In the bread of the present disclosure, ingredients that serve as a source of protein may be blended into the dough depending on the type of protein to be contained.

[0017] Examples of raw materials that serve as sources of wheat protein include wheat flour and wheat gluten. The wheat flour may be refined wheat flour or whole wheat flour. Either hard wheat or soft wheat may be used as the wheat flour, and any of weak flour, all-purpose flour, and strong flour may be used. A suitable example of these grain flours is wheat flour, more preferably whole wheat flour. Whole wheat flour typically contains approximately 10 to 18% by mass of protein. Wheat gluten is a substance in which glutenin and gliadin contained in wheat flour are connected in a network-like structure, and in the present disclosure, dried active gluten can be used as wheat gluten. Active gluten typically contains approximately 60 to 90% by mass of protein.

[0018] Examples of raw materials that serve as sources of soy protein include soy flour, concentrated soy protein, and isolated soy protein. Soy flour is a raw material made from powdered soybeans, and in the present disclosure, heat-treated devitalized soy flour can be used as the soy flour. Soy flour typically contains approximately 35 to 45% by mass of protein. Concentrated soy protein is a raw material made by concentrating and processing protein from soybeans. Isolated soy protein is a raw material made by extracting only protein from soybeans. Among the raw materials that serve as sources of soy protein, soy flour is a suitable example.

[0019] Examples of raw materials that can serve as egg protein sources include egg yolk powder, egg white powder, and proteins isolated from chicken eggs. Egg yolk powder is a powdered raw material obtained by drying the yolk of chicken eggs. Egg yolk powder typically contains 25 to 35% by mass of protein. Egg white powder is a raw material obtained by separating egg white from chicken eggs and powdering it. Among the raw materials that can serve as egg protein sources, egg yolk powder is a suitable example.

[0020] Examples of raw materials that can serve as a source of milk protein include skim milk powder, whey, and proteins isolated from milk.

[0021] Examples of raw materials that can serve as sources of rice protein include rice flour and proteins isolated from rice.

[0022] Source materials for pea protein include, for example, pea flour, protein isolated from peas, etc.

[0023] Examples of raw materials that can serve as a source of corn protein include corn flour and protein isolated from corn.

[0024] Examples of raw materials that can serve as a source of barley protein include barley flour and protein isolated from barley.

[0025] Examples of raw materials that can serve as sources of rye protein include rye flour and proteins isolated from rye.

[0026] In the bread of the present disclosure, the total protein content in the dough is not particularly limited, as long as it is 30% by mass or more based on the dry mass of the dough, but examples include 30 to 50% by mass, preferably 31 to 45% by mass, more preferably 32 to 40% by mass, and even more preferably 34 to 39% by mass.

[0027] Since the bread of the present disclosure preferably contains wheat flour, preferably whole wheat flour and wheat gluten, a suitable example of the bread of the present disclosure is one that contains at least wheat protein. In the bread of the present disclosure, the wheat protein content in the dough may be appropriately set in consideration of the contents of other proteins so that the total protein content in the dough is 30% by mass or more per dry mass of the dough, for example, 15 to 35% by mass, preferably 20 to 30% by mass, and more preferably 24 to 28% by mass.

[0028] Furthermore, the bread of the present disclosure more preferably contains soy protein and / or egg protein in addition to wheat protein, and even more preferably contains wheat protein, soy protein, and egg protein.

[0029] When soy protein is contained in the bread of the present disclosure, the content of soy protein in the dough may be appropriately set in consideration of the contents of other proteins so that the total content of proteins in the dough is 30% by mass or more per dry mass of the dough, for example, 1 to 20% by mass, preferably 3 to 15% by mass, and more preferably 5 to 9% by mass.

[0030] Furthermore, when egg protein is added to the bread of the present disclosure, the content of egg protein in the dough may be appropriately set in consideration of the contents of other proteins so that the total content of proteins in the dough is 30% by mass or more per dry mass of the dough, for example, 0.1 to 10% by mass, preferably 0.2 to 5% by mass, and more preferably 0.5 to 2% by mass.

[0031] In the bread of the present disclosure, the content of the raw material that serves as a protein source may be set so as to satisfy the above-mentioned protein content, taking into consideration the type of raw material that serves as the protein source, the protein content, etc.

[0032] For example, in the present disclosure, the content of wheat flour (including whole wheat flour) in the dough is, for example, 30 to 65% by mass, preferably 40 to 60% by mass, and more preferably 50 to 55% by mass, based on the dry mass of the dough.

[0033] Furthermore, when active gluten is contained in the bread of the present disclosure, the content of active gluten contained in the dough is, for example, 5 to 40% by mass, preferably 10 to 30% by mass, and more preferably 18 to 23% by mass, based on the dry mass of the dough.

[0034] Furthermore, when soy flour is contained in the bread of the present disclosure, the content of soy flour in the dough is, for example, 5 to 35% by mass, preferably 10 to 30% by mass, and more preferably 15 to 20% by mass, based on the dry mass of the dough.

[0035] Furthermore, when egg yolk powder is contained in the bread of the present disclosure, the content of egg yolk powder in the dough is, for example, 0.1 to 15% by mass, preferably 0.5 to 10% by mass, and more preferably 1 to 4% by mass, based on the dry mass of the dough.

[0036] [Acetic Acid] In the bread of the present disclosure, the dough used for production contains acetic acid. In the bread of the present disclosure, acetic acid plays a role in improving shelf life. In conventional techniques, bread containing acetic acid has a sour taste and sour odor, and is unable to fully exhibit the original flavor of the bread. However, in the bread of the present disclosure, by adding amylase to the dough, the sour taste and sour odor can be suppressed even though the bread contains acetic acid, and the original excellent flavor of the bread can be exhibited.

[0037] As the acetic acid, not only purified acetic acid but also raw materials containing acetic acid such as brewed vinegar may be used.

[0038] In the bread of the present disclosure, the content of acetic acid in the dough is, for example, 0.01 to 2% by mass, preferably 0.05 to 1% by mass, and more preferably 0.1 to 0.5% by mass, per dry mass of the dough.

[0039] [Amylase] The dough used to produce the bread of the present disclosure contains amylase. By incorporating amylase into dough containing 30% or more by weight of protein and acetic acid per dry weight of the dough, it is possible to suppress the sour taste and sour odor caused by acetic acid. Furthermore, when the bread of the present disclosure contains whole wheat flour, incorporating amylase into the dough can also suppress the bran and soybean odor caused by whole wheat flour. Furthermore, when the bread of the present disclosure contains soy flour, adjusting the amylase content in the dough can also suppress the bean odor caused by soy flour.

[0040] The type of amylase used in the present disclosure is not particularly limited, but examples thereof include α-amylase, β-amylase, and glucoamylase. These amylases may be used alone or in combination of two or more.

[0041] The origin of the amylase used in the present disclosure is not particularly limited, and examples thereof include Bacillus microorganisms such as Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, and Bacillus flexus; Aspergillus microorganisms such as Aspergillus niger and Aspergillus oryzae; etc. In the present disclosure, amylases from one origin may be used alone, or amylases from two or more origins may be used in combination.

[0042] The amylase is preferably an α-amylase or a β-amylase. The α-amylase is more preferably an α-amylase derived from a microorganism of the genus Bacillus, even more preferably an α-amylase derived from Bacillus subtilis or Bacillus amyloliquefaciens. The β-amylase is more preferably a β-amylase derived from a microorganism of the genus Bacillus, even more preferably a β-amylase derived from Bacillus flexus.

[0043] In the bread of the present disclosure, the content of amylase contained in the dough may be set appropriately taking into consideration the type of amylase used, the time the amylase acts during bread production, etc., and may include, for example, 0.01 to 300 U, 0.02 to 200 U, 0.1 to 200 U, or 0.1 to 100 U of amylase per 1 g of dry mass of dough. From the viewpoint of effectively suppressing sourness and acidic odor, and further, when whole wheat flour is included, effectively suppressing the bran and soybean pulp odor caused by whole wheat flour, the content of amylase per 1 g of dry mass of dough may be 0.03 to 200 U or 0.1 to 50 U, preferably 0.4 to 30 U, more preferably 1 to 30 U, even more preferably 2 to 25 U, particularly preferably 3 to 20 U, and even more preferably 3.5 to 10 U. Furthermore, when the amylase content in dough is 1 U or more, preferably 2 U or more, and more preferably 3 U or more per gram of dry weight dough, it is possible to effectively suppress the beany odor caused by soy flour, even when soy flour is included. Here, 1 U of activity unit for α-amylase is the activity that uses soluble starch as a substrate and decomposes 1 mL of a 1 w / v% starch solution to an iodine color intensity of 66% transmittance at a wavelength of 670 nm and an optical path length of 10 mm at 40°C and pH 5.0 in 30 minutes. Furthermore, 1 U of activity unit for β-amylase is the amount of enzyme that increases the reducing power equivalent to 1 mg of glucose per minute. Specifically, the "1 unit" of β-amylase is the value measured according to the starch saccharifying power measurement method described in the Voluntary Standards for Existing Food Additives, Fourth Edition (published by the Japan Food Additives Association on October 16, 2008).

[0044] [Sodium Chloride] In addition to the above-described components, the bread of the present disclosure may contain sodium chloride. When sodium chloride is contained in the bread of the present disclosure, the content of sodium chloride in the dough is, for example, 0.05 to 5% by mass, preferably 0.1 to 3% by mass, more preferably 0.2 to 1% by mass, based on the dry mass of the dough.

[0045] [Yeast] The bread of the present disclosure contains yeast required for fermentation. The yeast may be baker's yeast, but in addition to baker's yeast, brewer's yeast or the like may also be included as needed. The yeast may also be any of dry yeast, instant dry yeast, fresh yeast, etc. One type of yeast may be used alone, or two or more types may be used in combination.

[0046] In the bread of the present disclosure, the yeast content in the dough is, for example, 0.1 to 5% by mass, preferably 0.3 to 3% by mass, and more preferably 0.5 to 2% by mass, based on the dry mass of the dough.

[0047] [Other Ingredients] The bread of the present disclosure may contain ingredients other than those described above. The other ingredients that can be included in the bread of the present disclosure may be selected from food ingredients and additives commonly used in bread production, depending on the quality, flavor, texture, etc. to be imparted. Examples of such ingredients include sweeteners such as sugar, reduced starch syrup, white sugar, liquid sugar, powdered starch syrup, starch syrup, and artificial sweeteners; fats and oils such as shortening, margarine, butter, powdered oils and fats, fat spreads, lard, salad oil, olive oil, and emulsified oils and fats; chocolate, cheese, yogurt, baking powder, yeast food, bittern, gelatin, tea leaves, alcohol, emulsifiers, spices, Western liquors, dried fruit, nuts, flavorings, dietary fiber, leavening agents, dough improvers, antioxidants, pH adjusters, preservatives, acidulants, etc. These ingredients may be used alone or in combination of two or more.

[0048] [Bread Production] The bread of the present disclosure can be produced by preparing dough using the above-mentioned ingredients and an appropriate amount of water, and then going through processes such as fermentation (primary fermentation, floor time), dividing, shaping, proofing (secondary fermentation), baking, etc. Although no limiting interpretation is desired, it is believed that in the production of bread of the present disclosure, an enzymatic reaction caused by amylase proceeds in the dough during the process from dough preparation to before baking, thereby suppressing sourness and sour odor, as well as other odors such as bran and soybean pulp.

[0049] Furthermore, since the content of ingredients other than water hardly changes between the dough and the bread baked from that dough, in the bread of the present disclosure, the content of each ingredient per dry mass of the bread is approximately the same as the content of each ingredient per dry mass of the dough used to make the bread.

[0050] [Type of Bread] The type of bread of the present disclosure is not particularly limited, but examples include white bread, round bread, bun, croissant, butter roll, one loaf bread, muffin, French bread, other sweet bread, and the like.

[0051] 3. Bread Mix The present disclosure further provides a bread mix containing 30% by mass or more of protein per dry mass, acetic acid, and amylase. The bread mix of the present disclosure is a mix containing the ingredients of the bread, and by using the bread mix of the present disclosure, the bread can be easily produced.

[0052] The types and contents of ingredients contained in the bread mix flour of the present disclosure are as described in the section "2. Bread (Part 1)" above.

[0053] The bread can be obtained by adding an appropriate amount of water to the bread mix flour of the present disclosure to prepare dough, and subjecting it to processes such as fermentation (primary fermentation), dividing, shaping, proofing (secondary fermentation), and baking.

[0054] 4. Bread (Part 2) Another embodiment of the bread of the present disclosure is a bread obtained from a dough containing acetic acid and 30% by mass or more of protein per dry mass of the dough, and in which the molecular weight distribution of sugars measured under the measurement conditions described below satisfies the following: the ratio of sugars having a molecular weight of 1,000 or more but less than 3,000 is 23% or less, and the ratio of sugars having a molecular weight less than 1,000 is 57% or more, relative to the total amount of sugars. The bread of this embodiment is described in detail below.

[0055] The bread of this embodiment is obtained from a dough containing 30% by mass or more of protein per dry mass of the dough and acetic acid. The types of protein and acetic acid used in the bread of this embodiment are as described in the above section "2. Bread (Part 1)." The contents of protein and acetic acid contained in the dough of the bread of this embodiment are as described in the above section "2. Bread (Part 1)."

[0056] In the bread of this embodiment, the molecular weight distribution of sugars measured under the following conditions is such that the ratio of sugars with a molecular weight of 1,000 to 3,000 is 23% or less, and the ratio of sugars with a molecular weight of less than 1,000 is 57% or more, relative to the total amount of sugars. By satisfying this molecular weight distribution, it is possible to suppress the sour taste and sour odor in bread made from dough containing acetic acid and 30% or more protein per dry mass of the dough. Furthermore, by satisfying this molecular weight distribution, it is possible to suppress the bran and soybean pulp odors caused by whole wheat flour, even when whole wheat flour is included. <Conditions for Measuring the Molecular Weight Distribution of Sugars> (1) 0.05 g of bread is shredded, 10 mL of 0.1 mol / L sodium nitrate solution is added, and the bread is left to stand overnight at room temperature, after which it is filtered through a membrane filter. (2) The resulting filtrate is subjected to HPLC using a size exclusion column to obtain a chromatogram. The molecular weight of each peak is determined from a calibration curve prepared using pullulan and maltotriose of known molecular weights as standards. (3) The peak area of ​​a sugar having a molecular weight of 1,000 or more and less than 3,000 relative to the total peak area is calculated as the ratio of sugars having a molecular weight of 1,000 or more and less than 3,000 relative to the total amount of sugars. Also, the peak area of ​​a sugar having a molecular weight less than 1,000 relative to the total peak area is calculated as the ratio of sugars having a molecular weight less than 1,000 relative to the total amount of sugars.

[0057] The ratio of sugars having a molecular weight of 1,000 or more and less than 3,000 to the total amount of sugars may be 23% or less, preferably 5 to 23%, and more preferably 8 to 23%. In particular, from the viewpoints of further improving the effect of suppressing sourness and sour odor, effectively suppressing bran and soybean odor when whole wheat flour is included, and suppressing bean odor when soy flour is included, the ratio of sugars having a molecular weight of 1,000 or more and less than 3,000 to the total amount of sugars is more preferably 10 to 20%, even more preferably 12 to 18%, and particularly preferably 12 to 16%.

[0058] The ratio of sugars having a molecular weight of less than 1,000 to the total amount of sugars may be 57% or more, preferably 57 to 70%. In particular, from the viewpoints of further improving the effect of suppressing sourness and sour odor, effectively suppressing bran and soybean odor when whole wheat flour is included, and suppressing bean odor when soy flour is included, the ratio of sugars having a molecular weight of less than 1,000 to the total amount of sugars is more preferably 60 to 70%, even more preferably 63 to 69%, and particularly preferably 65 to 68%.

[0059] In the bread of this embodiment, the ratio of sugars having a molecular weight of 3,000 or more and less than 10,000 to the total amount of sugars is not particularly limited, but may be, for example, 3 to 30%, preferably 5 to 11%, and more preferably 8 to 11%. The ratio of sugars having a molecular weight of 3,000 or more and less than 10,000 to the total amount of sugars is a value determined under the measurement conditions for the molecular weight distribution of sugars described above.

[0060] In the bread of this embodiment, the ratio of sugars having a molecular weight of 10,000 or more and less than 30,000 to the total amount of sugars is not particularly limited, but may be, for example, 1 to 15%, preferably 3 to 10%, and more preferably 3 to 7% or 5 to 7%. The ratio of sugars having a molecular weight of 10,000 or more and less than 30,000 to the total amount of sugars is a value determined by the measurement conditions for the molecular weight distribution of sugars described above.

[0061] In the bread of this embodiment, the ratio of sugars having a molecular weight of 30,000 or more and less than 100,000 to the total amount of sugars is not particularly limited, but may be, for example, 1 to 10%, preferably 1 to 5% or 2 to 5%, and more preferably 1 to 3%. The ratio of sugars having a molecular weight of 30,000 or more and less than 100,000 to the total amount of sugars is a value determined by the measurement conditions for the molecular weight distribution of sugars described above.

[0062] In the bread of this embodiment, the ratio of sugars having a molecular weight of 100,000 or more to the total amount of sugars is not particularly limited, but may be, for example, 5% or less, preferably 3% or less, and more preferably 2% or less. The ratio of sugars having a molecular weight of 100,000 or more to the total amount of sugars is a value determined by the measurement conditions for the molecular weight distribution of sugars described above.

[0063] In order to satisfy the molecular weight distribution of the sugars, the types and contents of the ingredients to be blended may be adjusted as appropriate. For example, as described in "2. Bread (Part 1)" above, the molecular weight distribution of the sugars can be suitably satisfied by making bread using dough containing amylase in addition to 30% by mass or more of protein and acetic acid per dry mass.

[0064] The starch content of the bread of this embodiment is not particularly limited, but may be, for example, 20 to 40% by weight, preferably 20 to 35% by weight, more preferably 20 to 30% by weight, and even more preferably 24 to 28% by weight, based on the dry weight of the bread. The starch content of bread is determined under the following measurement conditions. <Conditions for measuring starch content> (1) 0.05 g of bread is shredded and placed in 40 mL of 50% by volume ethanol aqueous solution, stirred, and allowed to stand. The supernatant is then removed, and the above procedure is repeated until the low-molecular-weight sugars are completely removed. (2) 20 mL of ion-exchanged water and 2 mL of 10% by weight sodium hydroxide aqueous solution are added to the residue from which the low-molecular-weight sugars have been completely removed, and the mixture is heated to gelatinize the residue (starch). The mixture is then neutralized to a pH of 7. (3) Next, amyloglucosidase is added to decompose the starch into glucose, and the amount of glucose in the solution after the reaction is measured. (4) Calculate the amount of starch from the amount of glucose according to the formula below, and determine the amount of starch per 1 g of dry mass of bread, taking into account the calculated amount of starch, the mass of the measurement sample, the dilution ratio at the time of measurement, etc.

[0065] In the bread of this embodiment, the free maltose content is not particularly limited, but may be, for example, 0.5 to 10% by weight, preferably 1.5 to 10% by weight, more preferably 3 to 8% by weight, and even more preferably 4 to 8% by weight per dry weight of the bread. Furthermore, the free glucose content is not particularly limited, but may be, for example, 0.01 to 5% by weight, preferably 0.1 to 2% by weight, more preferably 0.3 to 0.8% by weight, and even more preferably 0.4 to 0.7% by weight per dry weight of the bread. Here, the free maltose and free glucose contents in bread are values ​​determined under the following measurement conditions. <Measurement conditions for free maltose and free glucose> (1) 2.5 g of bread was shredded and placed in 30 mL of 50% ethanol aqueous solution, and ultrasonicated to elute the free maltose and free glucose. Next, 50% ethanol aqueous solution was added to the resulting solution to a total volume of 50 mL, and the resulting solution was filtered to remove any residue. (2) The obtained filtrate is concentrated and then subjected to HPLC to measure the glucose and maltose amounts. (3) Taking into consideration the measured glucose and maltose amounts, the mass of the measurement sample, the dilution ratio at the time of measurement, etc., the free glucose content and the free maltose amount per 1 g of dry mass of bread are calculated.

[0066] The bread of this embodiment contains various ingredients other than protein and acetic acid. The types and contents of the ingredients other than protein and acetic acid contained in the bread of this embodiment may be appropriately set so as to satisfy the molecular weight distribution, but suitable ingredients and contents are as described in the section "2. Bread (Part 1)" above.

[0067] The bread of this embodiment can be produced by preparing dough containing predetermined ingredients and then going through processes such as fermentation (primary fermentation), dividing, shaping, proofing (secondary fermentation), and baking. The type of bread of this embodiment is not particularly limited, but examples include those described in the section "2. Bread (Part 1)" above.

[0068] The present disclosure will be specifically described below using examples, but the present invention is not limited to these examples.

[0069] Test Example 11. Bread Production The ingredients shown in Table 1, except for butter, were added to a mixer and mixed at low speed for 2 minutes and at high speed for 7 minutes. Then, butter was added and mixed at low speed for 1 minute and at high speed for 7 minutes to obtain a dough. Then, a 40-minute floor time was allowed at a temperature of 28°C and a humidity of 75% RH. Next, 70 g of the dough was cut out, divided, rounded, and shaped. The shaped dough was fermented for 60 minutes at a temperature of 38°C and a humidity of 85% RH. Then, the dough was baked in an oven at 210°C for 12 minutes with an upper heat of 210°C and a lower heat of 210°C, and then allowed to cool at room temperature for 40 minutes to obtain a round loaf. The cooled round loaf was packaged with a quality preservative and stored at 30°C.

[0070]

[0071] 2. Evaluation Method Bread stored at 30°C for 3 days after completion of production was subjected to a sensory evaluation. First, bread of Reference Example 1 (not containing whole wheat flour and devitalized soy flour) and bread of Comparative Example 1-1 (containing whole wheat flour and devitalized soy flour) were tasted to understand the characteristics of the bran / okara odor (smell like bran or okara) and bean odor (gray bean odor), and also evaluated for sourness and acidity. Next, bread of Comparative Example 1-2 (containing whole wheat flour, devitalized soy flour, and acetic acid) was tasted to understand the characteristics of the sourness and acidity (smell of acetic acid) due to the presence of acetic acid, and also evaluated for the bran / okara odor and bean odor. Next, bread of Examples 1-1 and 1-2 (containing whole wheat flour, devitalized soy flour, acetic acid, and α-amylase) were tasted to evaluate the flavors of sourness, sourness, bran / okara odor, and bean odor. Seven evaluators, who are skilled in sensory evaluation of bread, scored the breads on a nine-point scale according to the following criteria, and the average score was calculated. Furthermore, the seven evaluators jointly evaluated the effects of improving the sourness, sour smell, bran / soybean pulp smell, and bean smell of the breads of Examples 1-1 and 1-2 according to the following criteria.

[0072] (Flavor evaluation criteria) 1: No aroma detected. 2: Almost no aroma detected. 3: Slight aroma detected. 4: Slight aroma detected. 5: Aroma detected. 6: Slightly strong aroma detected. 7: Strong aroma detected. 8: Quite strong aroma detected. 9: Intense aroma detected.

[0073] (Criteria for evaluation of flavor improvement effect) A: Effective. B: Somewhat effective. C: No effect. D: Excessive effect, detracting from flavor value.

[0074] 3. Evaluation Results The results of the flavor evaluation of each bread are shown in Table 2. Bread containing whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more (Comparative Example 1-1) had increased bran / okara odor and bean odor. Furthermore, bread containing whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more and acetic acid (Comparative Example 1-2) had increased sourness and acidic odor in addition to the bran / okara odor and bean odor. In contrast, bread containing whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more and acetic acid and α-amylase (Examples 1-1 and 1-2) had reduced sourness and acidic odor, and the bran / okara odor was also reduced. In particular, bread containing 3.94 U / g of α-amylase (Example 1-2) showed improved effects on improving sourness, sour odor, and bran / okara odor, and also showed a suppression effect on bean odor.

[0075]

[0076] Test Example 21. Bread Production Round bread was produced under the same conditions as in Test Example 1, except that the raw material composition shown in Table 3 was used.

[0077]

[0078] 2. Evaluation Method Bread stored at 30°C for three days after production was eaten, and the sour taste and sour odor (smell of acetic acid) were scored according to the following criteria. The sour taste and sour odor were evaluated using a score of 0.0 to 5.0 points in increments of 0.5 points based on the following criteria (0.0 points for the weakest sour taste or sour odor, and 5.0 points for the strongest sour taste or sour odor). Evaluation was performed by five experts in sensory taste evaluation, and the average score was calculated. (Sour taste or sour odor criteria) 0.0 points: No sour taste or sour odor detected. 1.0 points: The strength of the sour taste or sour odor detected when eating bread of Reference Example 2-1 (no acetic acid added). The sour taste or sour odor was barely detected. 2.0 points: The strength of the sour taste or sour odor detected when eating bread of Reference Example 2-2 (containing 0.2% by mass of acetic acid per dry weight of dough). A slight sour taste or sour smell is perceived. 3.0 points: The strength of the sour taste or sour smell felt when eating the bread of Comparative Example 2 (containing 0.3% by mass of acetic acid per dry weight of dough). The sour taste or sour smell is perceived as being somewhat strong. 4.0 points: The strength of the sour taste or sour smell felt when eating the bread of Reference Example 2-3 (containing 0.4% by mass of acetic acid per dry weight of dough). The sour taste or sour smell is perceived as being clearly strong. 5.0 points: The sour taste or sour smell is perceived as being very strong.

[0079] 3. Evaluation Results The results of the flavor evaluation of each bread are shown in Table 4. In breads containing whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more (Reference Examples 2-1 to 2-3, Comparative Example 2), the sourness and sour odor increased depending on the amount of acetic acid added. In contrast, in breads containing whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more, and containing acetic acid and α-amylase or β-amylase (Examples 2-1 and 2-2), the sourness and sour odor were suppressed. Furthermore, although the α-amylase used in Example 2-1 was derived from a different source than the α-amylase used in Examples 1-1 and 1-2, it was able to suppress the sourness and sour odor caused by acetic acid, demonstrating that it can be used regardless of the source of the α-amylase.

[0080]

[0081] Test Example 31. Bread Production Round bread was produced under the same conditions as in Test Example 1, except that the raw material composition shown in Table 5 was used.

[0082]

[0083] 2. Evaluation Method Bread stored at 30°C for three days after production was eaten, and the bran / okara odor (smell like bran or okara) and bean odor (gray bean odor) were scored according to the following criteria. The bran / okara odor and bean odor were evaluated using a score in increments of 0.5 points within a range of 1.0 to 5.0 points based on the following criteria (1.0 points for the weakest bran / okara odor or bean odor, and 5.0 points for the strongest bran / okara odor or bean odor). The evaluation was carried out by five experts in sensory taste evaluation, and the average score was calculated. (Baseline score for sourness or sour odor) 1.0 points: The strength of the bran / okara odor or bean odor perceived when eating bread of Reference Example 3-1 (not containing devitalized soy flour). The bran / okara odor or bean odor was barely perceived. 2.0 points: The strength of the bran / okara or bean smell felt when eating the bread of Reference Example 3-2 (containing 8.9% by mass of devitalized soy flour per dry weight of dough). The bran / okara or bean smell is slightly noticeable. 3.0 points: The strength of the bran / okara or bean smell felt when eating the bread of Comparative Example 3 (containing 17.5% by mass of devitalized soy flour per dry weight of dough). The bran / okara or bean smell is slightly strong. 4.0 points: The strength of the bran / okara or bean smell felt when eating the bread of Reference Example 3-3 (containing 26.1% by mass of devitalized soy flour per dry weight of dough). The bran / okara or bean smell is clearly strong. 5.0 points: The bran / okara or bean smell is very strong.

[0084] 3. Evaluation Results The results of the flavor evaluation of each bread are shown in Table 6. In breads blended with whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more (Reference Examples 3-2, 3-3, Comparative Example 3), the bran / okara odor and bean odor increased depending on the amount of devitalized soy flour blended. In contrast, in breads blended with whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more and blended with acetic acid and α-amylase (Examples 3-1 to 3-3), the bran / okara odor and bean odor were suppressed.

[0085]

[0086] Test Example 41. Bread Production Round bread was produced under the same conditions as in Test Example 1, except that the raw material composition shown in Table 7 was used.

[0087]

[0088] 2. Evaluation method Bread stored at 30°C for 3 days after production was eaten, and the sour taste, sour odor (smell of acetic acid), bran / okara odor (smell like bran or soy pulp), and bean odor (gray bean odor) were evaluated. The sour taste and sour odor were evaluated under the same conditions as in Test Example 2. The bread used as the reference point when scoring the sour taste and sour odor was also the same as in Test Example 2. The bran / okara odor and bean odor were evaluated under the same conditions as in Test Example 3. The bread used as the reference point when scoring the bran / okara odor and bean odor was also the same as in Test Example 3.

[0089] 3. Evaluation Results The results of the evaluation of the flavor of each bread are shown in Table 8. As a result, it was confirmed that even when the types of whole wheat flour and devitalized soy flour were changed, in breads that contained whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more, the sour taste, sour odor, bran / okara odor, and bean odor were suppressed in the breads (Examples 4-1 and 4-2) that contained acetic acid and α-amylase.

[0090]

[0091] Test Example 51. Bread Production Round bread was produced under the same conditions as in Test Example 1, except that the raw material composition shown in Table 9 was used.

[0092]

[0093] 2. Evaluation method Bread stored at 30°C for 3 days after production was eaten, and the sour taste and sour odor (smell of acetic acid) were evaluated. The sour taste and sour odor were evaluated under the same conditions as in Test Example 2. The bread used as the reference point when scoring the sour taste and sour odor was also the same as in Test Example 2.

[0094] 3. Evaluation Results The results of the evaluation of the flavor of each bread are shown in Table 10. As a result, in breads containing whole wheat flour and devitalized soy flour to increase the protein content to 30% by mass or more, the sour taste and sour odor could not be suppressed even when acetic acid and maltose or galactooligosaccharide were added.

[0095]

[0096] Test Example 61. Evaluation Method For each of the breads of Examples 1-1 to 1-2 and Comparative Example 1-1, the contents of free glucose, free maltose, total glucose (glucose after hydrolysis), and starch were measured by the following method. In addition, for each of the breads of Comparative Examples 1-2, 3, 4-1, 4-2, 5-1, and 5-2, Reference Examples 3-1 to 3-3, and Examples 1-1, 1-2, 2-1, 3-2, 3-3, 4-1, and 4-2, the molecular weight distribution of the sugars contained in the bread was measured by the following method.

[0097] 1-1. Method for Measuring Free Glucose and Free Maltose Contents: 2.5 g of shredded bread was placed in a beaker, 30 mL of 50% ethanol solution was added, and the mixture was sonicated in an ultrasonic cleaner for 30 minutes. Next, 50% ethanol solution was added to bring the total volume to 50 mL, followed by filtration using filter paper (No. 5B). A portion of the filtrate was measured and placed in an eggplant flask. The pressure was reduced to dryness using an evaporator, and water was added to prepare a 5x concentrated solution (1 / 5 the volume of the filtrate placed in the eggplant flask). The resulting concentrated solution was filtered using a 0.45 μm membrane filter. The resulting filtrate was subjected to HPLC under the following conditions to measure the glucose and maltose contents. The free glucose and maltose contents per 1 g of dry mass of bread were calculated taking into account the measured glucose and maltose amounts, the mass of the measurement sample, and the dilution ratio during measurement. (HPLC conditions) Analytical device: LC-20AD (Shimadzu Corporation) Detector: Electrical conductivity meter RF-20A XS (Shimadzu Corporation) Column: Wakosil 5NH2, φ4.6 mm × 150 mm (Fujifilm Wako Pure Chemical Industries, Ltd.) Column temperature: 25°C Mobile phase: Solution containing 75 parts by mass of acetonitrile and 25 parts by mass of water Flow rate: Mobile phase 1 mL / min Injection amount: 2 μL Excitation wavelength: 320 nm Measurement wavelength: 430 nm Post-column conditions: The reaction solution was a 3% by mass aqueous boric acid solution containing 1% by mass of L-arginine, the reaction solution flow rate was 0.7 mL / min, and the reaction temperature was 150°C

[0098] 1-2. Measurement method for total glucose content (amount of glucose after hydrolysis): 4 mL of 72 wt% aqueous sulfuric acid solution was added to 0.6 g of shredded bread and stirred at 20°C for 1 hour. Ion-exchanged water was then added to adjust the sulfuric acid concentration to 4 wt% and the mixture was heated at 121°C for 1 hour using an autoclave. After cooling, the mixture was neutralized to pH 7 using sodium hydroxide. 200 mL of the neutralized solution was measured and filtered through filter paper. The filtrate was diluted 25-fold with ion-exchanged water and then filtered through a 0.45 μm membrane filter. The resulting filtrate was subjected to high-performance liquid chromatography (HPLC) under the following conditions to measure the glucose content. The total glucose content per 1 g of dry mass of bread was calculated taking into account the measured glucose content, the mass of the measurement sample, the dilution ratio during measurement, etc. (HPLC conditions) Analytical device: LC-20AD (Shimadzu Corporation) Detector: Electrical conductivity meter RF-20A XS (Shimadzu Corporation) Column: TSKgel Sugar AXI, φ4.6 mm × 150 mm (Tosoh Corporation) Column temperature: 60°C Mobile phase: 0.5 mol / L borate buffer solution, pH 8.7 Flow rate: Mobile phase 0.4 mL / min Injection amount: 20 μL Excitation wavelength: 320 nm Measurement wavelength: 430 nm Post-column conditions: Reaction solution was an aqueous solution containing 1% by mass of L-arginine, reaction solution flow rate was 0.7 mL / min, and reaction temperature was 150°C

[0099] 1-3. Method for Measuring Starch Content 0.3 g of bread was collected as a measurement sample and placed in a 250 mL glass centrifuge tube. 40 mL of 50% by volume ethanol aqueous solution was added, stirred, and then allowed to stand (low molecular weight sugar extraction procedure). The supernatant was then filtered and removed using glass fiber filter paper (ADVANTEC GS-25, Toyo Roshi Kaisha, Ltd.) (low molecular weight sugar removal procedure). This low molecular weight sugar extraction and removal procedure was repeated until the low molecular weight sugars were completely removed. Complete removal of the low molecular weight sugars was confirmed by the phenol-sulfuric acid method. In the phenol-sulfuric acid method, 1 mL of the filtrate, 1 mL of 5 w / v% phenol aqueous solution, and 5 mL of concentrated sulfuric acid were added to a test tube and mixed, and the presence or absence of low molecular weight sugars was confirmed by checking for color development.

[0100] Next, the residue after extraction of low molecular weight sugars was transferred to a 250 mL glass centrifuge tube, and 20 mL of ion-exchanged water and 2 mL of 10 wt% aqueous sodium hydroxide were added and heated for 5 minutes to gelatinize the residue. The mixture was then neutralized to pH 7 using hydrochloric acid and sodium hydroxide. Next, 10 mL of glucoamylase solution (1.5 g of amyloglucosidase derived from Aspergillus niger (Megazyme) dissolved in 100 mL of 0.1 mol / L acetate buffer (pH 4.8)) was added and reacted at 37 °C for 2 hours. The reaction solution was filtered using filter paper (ADVANTEC No. 5B, Toyo Roshi Kaisha, Ltd.). The resulting filtrate was diluted 10-fold with ion-exchanged water, and the glucose level was measured using a glucose measurement kit (Glucose CII-Test Wako, Fujifilm Wako Pure Chemical Industries, Ltd.). The amount of starch was calculated from the amount of glucose according to the formula below, and the amount of starch per 1 g of dry mass of bread was determined taking into consideration the calculated amount of starch, the mass of the measurement sample, the dilution ratio at the time of measurement, etc.

[0101] 1-4. Method for Measuring the Molecular Weight Distribution of Sugars Contained in Bread 10 mL of 0.1 mol / L sodium nitrate solution was added to 0.05 g of shredded bread, allowed to stand overnight at room temperature, and then filtered through a 0.45 μm membrane filter. The resulting filtrate was subjected to HPLC using a size exclusion column under the following conditions. The results were analyzed using the 480II Data Station GPC program from System Instruments Co., Ltd. The molecular weight of each peak was estimated using a calibration curve created based on the elution time and molecular weight of the molecular standards. Pullulan standards with known molecular weights (Shodex Standard P-82 P-800, P-400, P-200, P-50, P-20, and P-5; Showa Denko K.K.) and maltotriose were used as molecular standards. (HPLC conditions) Analytical device: Shodex GPC-101 (Showa Denko K.K.) Detector: Differential refractometer RI-71S (Showa Denko K.K.) Column: Two connected TSKgel GMPW XL, φ7.8 mm × 300 mm (Tosoh Corporation) Column temperature: 40°C Mobile phase: 0.1 mol / L sodium nitrate solution Flow rate: Mobile phase 1 mL / min Injection volume: 100 μL

[0102] 2. Evaluation Results The measurement results of the contents of free glucose, free maltose, total glucose (glucose after hydrolysis), and starch are shown in Table 11. The breads of Examples 1-1 and 1-2 tended to have higher amounts of free maltose and free glucose and lower starch contents than the bread of Comparative Example 1-2.

[0103] The measurement results of the molecular weight distribution of sugars are shown in Tables 12 and 13. None of the breads of Comparative Examples 1-2, 3, 4-1, 4-2, 5-1, and 5-2 and Reference Examples 3-1 to 3-3 satisfied the conditions that the proportion of sugars with a molecular weight of 1,000 to 3,000 was 23% or less and the proportion of sugars with a molecular weight of less than 1,000 was 57% or more. In contrast, the breads of Examples 1-1, 1-2, 2-1, 3-2, 3-3, 4-1, and 4-2 satisfied the conditions that the proportion of sugars with a molecular weight of 1,000 to 3,000 was 23% or less and the proportion of sugars with a molecular weight of less than 1,000 was 57% or more. That is, in the breads of Examples 1-1, 1-2, 2-1, 3-2, 3-3, 4-1, and 4-2, the α-amylase incorporated into the dough breaks down sugars with a molecular weight of 1,000 to 3,000 into smaller molecules, increasing the proportion of sugars with a molecular weight of less than 1,000, which is presumably responsible for improving the sourness, sour odor, bran / okara odor, and bean odor. Therefore, it was revealed that bread containing acetic acid and a protein content of 30% or more by mass is effective in improving sourness and sour odor when the proportion of sugars with a molecular weight of 1,000 to 3,000 is 23% or less and the proportion of sugars with a molecular weight of less than 1,000 is 57% or more. Furthermore, it was revealed that satisfying this molecular weight distribution of sugars is also effective in improving bran / okara odor and bean odor.

[0104]

[0105]

[0106]

Claims

1. Bread obtained from dough containing 30% or more by weight of protein per dry weight of the dough, acetic acid, and amylase.

2. The bread of claim 1, wherein the dough contains whole wheat flour and / or soy flour.

3. The bread according to claim 1 or 2, wherein the amylase is α-amylase.

4. A bread mix flour containing 30% or more by mass of protein, acetic acid, and amylase.

5. A method for producing bread, comprising the steps of: adding water to the bread mix flour according to claim 4 to prepare dough; and fermenting and baking the dough obtained in said step.

6. Bread obtained from a dough containing 30% or more by weight of protein per dry weight of the dough and acetic acid, and in the molecular weight distribution of sugars obtained under the following measurement conditions, the ratio of sugars with a molecular weight of 1,000 or more and less than 3,000 to the total amount of sugars is 23% or less, and the ratio of sugars with a molecular weight of less than 1,000 is 57% or more. <Conditions for measuring the molecular weight distribution of sugars> (1) 0.05 g of bread is shredded, 10 mL of 0.1 mol / L sodium nitrate solution is added, and the mixture is left to stand at room temperature overnight, and then filtered using a membrane filter. (2) The obtained filtrate is subjected to HPLC using a size exclusion column to obtain a chromatograph. The molecular weight of each peak is determined from a calibration curve prepared using pullulan and maltotriose with known molecular weights as standards. (3) The peak area with a molecular weight of 1,000 or more and less than 3,000 relative to the total peak area is calculated as the ratio of saccharides with a molecular weight of 1,000 or more and less than 3,000 relative to the total amount of saccharides. In addition, the peak area with a molecular weight of less than 1,000 relative to the total peak area is calculated as the ratio of saccharides with a molecular weight of less than 1,000 relative to the total amount of saccharides.

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