Bread containing soybean flour and method for producing same

Abstract

The purpose of the present disclosure is to provide bread that contains soybean flour having a water-soluble nitrogen index of 70% or more and has good rise.　This bread is obtained from dough including a reducing agent and soybean flour having a water-soluble nitrogen index of 70% or more.

Description

Bread containing soy flour and method for producing the same

[0001] The present disclosure relates to a bread containing soy flour with a water-soluble nitrogen index of 70% or more and having good leavening. The present disclosure also relates to a bread mix flour and bread dough used to make the bread, and a method for making the bread.

[0002] Bread is a food that grows by forming a network using gluten (glutenin, gliadin), a protein contained in wheat, and retaining the carbon dioxide produced during fermentation by baker's yeast. However, wheat gluten has a low amino acid score because essential amino acids such as lysine are limiting amino acids, so it cannot be said to have sufficient nutritional value as a protein. On the other hand, soy protein has an amino acid score of 100, making the addition of soy flour effective in increasing the nutritional value of bread.

[0003] On the other hand, when bread is made from dough containing soy flour with a water-soluble nitrogen index of 70% or more, such as raw soy flour, the formation of a crosslinked network of wheat gluten is difficult, resulting in insufficient bread rise. Therefore, various techniques have been developed to improve the reduced rise of bread containing soy flour with a water-soluble nitrogen index of 70% or more. For example, Patent Document 1 describes that by incorporating whole soy flour, which is in powder form with an average particle size of 5 to 50 μm, has a neutral protease activity of 25 units / g or less, and has a water-soluble nitrogen index of 70% or more, into dough, a well-risen, moist, and delicious bread can be obtained. However, the technique of Patent Document 1 is limited by physical properties other than the water-soluble nitrogen index, and therefore is not applicable to all soy flours with a water-soluble nitrogen index of 70% or more.

[0004] JP 2014-197994 A

[0005] An object of the present disclosure is to provide bread containing soy flour with a water-soluble nitrogen index of 70% or more and having good rise.

[0006] It has been known that when an oxidizing agent is added to bread dough, the oxidizing agent acts on the thiol groups of gluten to form disulfide bonds, developing the gluten network and resulting in an increase in the specific volume of the baked bread. On the other hand, it has been known that when a reducing agent is added to bread dough, it breaks disulfide bonds, weakening the gluten network and reducing the specific volume of the baked bread. For this reason, it has been recognized that reducing agents should not be used for the purpose of increasing the specific volume of bread.

[0007] In light of this background of the prior art, the present inventors have conducted extensive research to solve the above-mentioned problems and have unexpectedly found that bread made from dough containing soy flour with a water-soluble nitrogen index of 70% or more and a reducing agent can be left to rise well and have sufficient leavening. The present disclosure has been completed through further research based on these findings.

[0008] That is, the present disclosure provides the following aspects of the invention. Item 1. Bread obtained from dough containing soy flour having a water soluble nitrogen index of 70% or more and a reducing agent. Item 2. The bread according to Item 1, wherein the reducing agent is at least one selected from the group consisting of vitamin E, catechins, flavonols, and phenolic acids. Item 3. The bread according to Item 1 or 2, wherein the soy flour having a water soluble nitrogen index of 70% or more is contained in an amount of 2% by mass or more, calculated as a dry mass, per dry mass of the dough. Item 4. The bread according to any one of Items 1 to 3, wherein the reducing agent is contained in an amount of 50 to 1150 ppm per dry mass of the dough. Item 5. A method for producing bread, comprising the steps of preparing dough containing soy flour having a water soluble nitrogen index of 70% or more and a reducing agent, and fermenting and baking the dough obtained in the step. Item 6. Bread dough containing soy flour having a water soluble nitrogen index of 70% or more and a reducing agent. Item 7. A bread mix flour containing soybean flour having a water-soluble nitrogen index of 70% or more and a reducing agent.

[0009] According to the present disclosure, bread containing soy flour with a water-soluble nitrogen index of 70% or more can be well-risen and have sufficient rise. Furthermore, one embodiment of the present disclosure can provide bread using soy flour with an amino acid score of 100, which can contribute to achieving SDG 3, "Ensure healthy lives and promote well-being for all at all ages."

[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 per dry mass of dough or bread is the ratio of the content of each ingredient (the content of the ingredient excluding moisture absorbed in or added to the ingredient) to the total amount (100% by mass) of ingredients other than moisture contained in the dough or bread.

[0012] In the present disclosure, the water-soluble nitrogen index (NSI) of soy flour is the ratio (wt%) of water-soluble nitrogen to the total nitrogen contained in soy flour, and is a value measured by the Kjeldahl method. The conditions for measuring the water-soluble nitrogen index of soy flour are as follows: First, 2.5 g of a sample is shaken with 100 mL of water at 40°C for 1.5 hours, and the resulting mixture is filtered to obtain a filtrate. The resulting filtrate is centrifuged (3000 g, 5 minutes) to separate the supernatant. 20 mL of the separated supernatant is transferred to a decomposition distillation tube, and the total nitrogen content in the supernatant is measured by the Kjeldahl method. Similarly, the total nitrogen in the sample is measured, and the water-soluble nitrogen index is calculated based on the following formula: Water-soluble nitrogen index = {total nitrogen amount in the supernatant / total nitrogen amount in the sample} x 100 (%)

[0013] 2. Bread The bread of the present disclosure is characterized in that it is obtained from dough containing soy flour having a water-soluble nitrogen index of 70% or more and a reducing agent. The bread of the present disclosure is described in detail below.

[0014] [Soy flour] The dough used to make the bread of the present disclosure contains soy flour with a water-soluble nitrogen index of 70% or more. In conventional techniques, when bread is made from dough containing soy flour with a water-soluble nitrogen index of 70% or more, there is a drawback that the bread does not rise sufficiently. However, in the bread of the present disclosure, by using dough containing soy flour with a water-soluble nitrogen index of 70% or more and a reducing agent described below, it is possible to make the bread rise well and provide sufficient rise.

[0015] Soy flour is a raw material made by powdering soybeans. The water-soluble nitrogen index of the soy flour used in the present disclosure may be 70% or higher, preferably 75% or higher, more preferably 80-97%, even more preferably 85-95%, and particularly preferably 85-90%. The water-soluble nitrogen index of soy flour varies depending on the type and condition of soybeans, the manufacturing conditions of defatted soybeans, etc., but soy flour obtained through a heat treatment process has a lower water-soluble nitrogen index. Therefore, raw soy flour that has not been subjected to a heat treatment process, or low-denatured soy flour that has been subjected to a mild heat treatment process, can have a water-soluble nitrogen index that meets the above range.

[0016] In addition, the soy flour used in the present disclosure may be either full-fat soy flour or defatted soy flour, as long as the water-soluble nitrogen index satisfies the above range.

[0017] The content of soy flour having a water-soluble nitrogen index of 70% or more in the dough used to produce the bread of the present disclosure is not particularly limited, but may be, for example, 2% by mass or more or 5% by mass or more, specifically 2 to 80% by mass, 2 to 60% by mass, 2 to 50% by mass, 5 to 80% by mass, 5 to 60% by mass, or 5 to 50% by mass. In conventional techniques, when the content of soy flour having a water-soluble nitrogen index of 70% or more in the dough is 10% by mass or more, particularly 35% by mass or more, the specific volume of the resulting bread tends to be even smaller, making it more difficult to leaven. In contrast, the bread of the present disclosure can be left to rise well even when the content of soy flour having a water-soluble nitrogen index of 70% or more in the dough is 10% by mass or more. In view of the characteristics of the bread of the present disclosure, the content of soy flour in the dough having a water-soluble nitrogen index of 70% or more, calculated on a dry mass basis, is preferably 10% by mass or more, more preferably 10 to 55% by mass, even more preferably 15 to 50% by mass, particularly preferably 25 to 50% by mass, even more preferably 35 to 50% by mass, and most preferably 35 to 45% by mass.

[0018] [Reducing Agent] The dough used to make the bread of the present disclosure contains a reducing agent in addition to soy flour with a water-soluble nitrogen index of 70% or more. It has been known that adding a reducing agent to bread dough breaks the disulfide bonds of gluten in the dough, weakening the gluten network and reducing the specific volume of the baked bread. However, in the bread of the present disclosure, the use of a soy flour with a water-soluble nitrogen index of 70% or more in combination with a reducing agent increases the specific volume of the baked bread and enables it to rise well.

[0019] The type of reducing agent used in the present disclosure is not particularly limited as long as it is acceptable for addition to food, and examples thereof include vitamin E such as tocopherol and tocotrienol; catechins such as catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate; vitamin C and derivatives thereof such as ascorbic acid and ascorbyl palmitate; sulfites such as sodium bisulfite; quercetin, quercetin, and the like. Examples of reducing agents include flavonols (flavonoids having a flavonol skeleton and glycosides thereof) such as citrine, rutin, and enzyme-treated rutin; phenolic acids such as chlorogenic acid and ferulic acid; gallic acid and esters thereof such as gallic acid and propyl gallate; plant extracts such as tea extract, enzymatically hydrolyzed apple extract, rosemary extract, bilberry extract, and pine bark extract; butylhydroxytoluene, butylhydroxyanisole, ethylenediaminetetraacetic acid, cysteine, glutathione, citric acid, phytic acid, and α-lipoic acid. These reducing agents may be used alone or in combination of two or more.

[0020] Suitable examples of reducing agents include vitamin E such as tocopherol and tocotrienol. Tocopherol and tocotrienol may be any of α-, β-, γ-, and δ-tocopherols and may be either d- or dl-isomers. Vitamin E does not need to be a purified product; for example, a vitamin premix containing vitamin E may be used.

[0021] Further, other examples of suitable reducing agents include catechins. In the present disclosure, catechins is a general term for catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. Catechins are abundantly contained in teas such as green tea, black tea, and oolong tea, and can therefore be used in the form of an extract extracted from tea leaves or the like.

[0022] Yet another example of a suitable reducing agent is a combination of vitamin E and catechins. When vitamin E and catechins are used in combination as a reducing agent, the ratio between them is not particularly limited, but may be, for example, 1 to 500 parts by mass, preferably 1 to 200 parts by mass, more preferably 10 to 120 parts by mass, and even more preferably 10 to 60 parts by mass of catechins per 100 parts by mass of vitamin E.

[0023] Other examples of suitable reducing agents include flavonols such as quercetin, quercesitrin, rutin, and enzyme-treated rutin. Among these, enzyme-treated rutin is preferred. Enzyme-treated rutin is a derivative of quercetin with increased water solubility due to the addition of glucose, and is a compound represented by the following general formula: In the following general formula, "Glc" represents a glucose residue.

[0024] Further examples of suitable reducing agents include phenolic acids such as chlorogenic acid and ferulic acid. Of these, ferulic acid is preferred.

[0025] The content of the reducing agent in the dough used to produce bread of the present disclosure may be appropriately set depending on the type of reducing agent used, but for example, the total amount of reducing agent per dry mass of the dough is 50 to 1150 ppm, preferably 100 to 1100 ppm, more preferably 200 to 1000 ppm, and even more preferably 280 to 950 ppm. More specifically, when vitamin E is used as the reducing agent, the vitamin E content per dry mass of the dough is preferably 100 to 1100 ppm, more preferably 280 to 1100 ppm, and even more preferably 600 to 1000 ppm. Furthermore, when catechins are used as the reducing agent, the catechins per dry mass of the dough are preferably 200 to 1000 ppm, more preferably 250 to 700 ppm, even more preferably 250 to 500 ppm, and particularly preferably 300 to 450 ppm. Furthermore, when vitamin E and catechins are used in combination as reducing agents, the total amount of vitamin E and catechins is preferably 200 to 700 ppm, more preferably 200 to 650 ppm, and even more preferably 300 to 500 ppm per dry mass of the dough. When flavonols are used as reducing agents, the flavonols are preferably 200 to 1000 ppm, more preferably 250 to 800 ppm, even more preferably 500 to 700 ppm, and particularly preferably 550 to 650 ppm per dry mass of the dough. When phenolic acid is used as a reducing agent, the phenolic acid is preferably 200 to 1000 ppm, more preferably 250 to 800 ppm, even more preferably 500 to 700 ppm, and particularly preferably 550 to 650 ppm per dry mass of the dough.

[0026] In the dough used to make bread of the present disclosure, the ratio of soy flour having a water-soluble nitrogen index of 70% or more to the reducing agent is not particularly limited, but for example, the total amount of reducing agent is 0.005 to 5.750 parts by mass, preferably 0.005 to 0.580 parts by mass, and more preferably 0.100 to 0.260 parts by mass per 100 parts by mass of soy flour having a water-soluble nitrogen index of 70% or more converted to dry mass. More specifically, when vitamin E is used as the reducing agent, the amount of vitamin E is preferably 0.005 to 5.75 parts by mass, more preferably 0.008 to 0.280 parts by mass, and even more preferably 0.015 to 0.250 parts by mass per 100 parts by mass of soy flour having a water-soluble nitrogen index of 70% or more converted to dry mass. Furthermore, when catechins are used as reducing agents, the amount of catechins is preferably 0.005 to 5.750 parts by mass, more preferably 0.050 to 0.250 parts by mass, and even more preferably 0.100 to 0.200 parts by mass per 100 parts by mass of soy flour having a water-soluble nitrogen index of 70% or more converted to dry weight. Furthermore, when vitamin E and catechins are used in combination as reducing agents, the total amount of vitamin E and catechins is preferably 0.005 to 4.000 parts by mass, more preferably 0.010 to 0.200 parts by mass, and even more preferably 0.090 to 0.160 parts by mass per 100 parts by mass of soy flour having a water-soluble nitrogen index of 70% or more converted to dry weight. Furthermore, when flavonols are used as the reducing agent, the amount of flavonols is preferably 0.005 to 5.750 parts by mass, more preferably 0.050 to 0.250 parts by mass, and even more preferably 0.100 to 0.200 parts by mass per 100 parts by mass of soy flour having a water-soluble nitrogen index of 70% or more, calculated on a dry basis. Furthermore, when phenolic acid is used as the reducing agent, the amount of phenolic acid is preferably 0.005 to 5.750 parts by mass, more preferably 0.050 to 0.250 parts by mass, and even more preferably 0.100 to 0.200 parts by mass per 100 parts by mass of soy flour having a water-soluble nitrogen index of 70% or more, calculated on a dry basis.

[0027] [Wheat Flour] The bread of the present disclosure may be gluten-free bread that does not contain wheat flour, but it is preferable that the dough contains wheat flour to provide a good texture.

[0028] The wheat flour may be refined wheat flour or whole wheat flour. The wheat flour may be either hard wheat or soft wheat, and may be any of weak flour, medium flour, and strong flour. Preferred examples of the wheat flour include strong flour and whole wheat flour.

[0029] When wheat flour is contained in the dough of the bread of the present disclosure, the content is not particularly limited, but may be, for example, 10 to 75% by mass, preferably 20 to 70% by mass, more preferably 35 to 60% by mass, and even more preferably 30 to 50% by mass, calculated as the dry mass.

[0030] [Protein Ingredient] To increase the protein content of the bread of the present disclosure, the dough used to make the bread of the present disclosure may contain a protein ingredient. In the present disclosure, a protein ingredient is a food ingredient containing protein as a main component. The type of protein ingredient is not particularly limited as long as it is edible, but examples include wheat gluten, soy protein (concentrated soy protein, isolated soy protein, etc.), egg protein, milk protein (skim milk powder, whey protein, etc.), etc. These protein ingredients may be used alone or in combination of two or more.

[0031] Among these protein materials, a suitable example is wheat gluten, which is a substance formed by glutenin and gliadin contained in wheat flour connecting in a network-like structure. In the present disclosure, dry active gluten can be used as wheat gluten.

[0032] In the case where a protein material is contained in the dough of the bread of the present disclosure, the content thereof is not particularly limited, but may be, for example, 0.1 to 20% by mass, preferably 1 to 18% by mass, more preferably 5 to 15% by mass, and even more preferably 8 to 13% by mass, calculated as the dry mass.

[0033] [Yeast] The dough used to produce 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.

[0034] In the bread of the present disclosure, the yeast content in the dough is, for example, 0.1 to 10% by mass, preferably 0.2 to 5% by mass, and more preferably 0.5 to 2% by mass, calculated on a dry mass basis.

[0035] [Other Ingredients] The dough used to produce the bread of the present disclosure may contain ingredients other than those described above. The other ingredients that can be contained in the bread of the present disclosure may be appropriately selected from food ingredients and additives generally used in bread production depending on the quality, flavor, texture, etc. to be imparted. Examples of such raw materials include edible flours such as rice flour, pea flour, corn flour, barley flour, and rye flour; sweeteners such as sugar, reduced starch syrup, white sugar, liquid sugar, powdered syrup, starch syrup, and artificial sweeteners; egg-derived materials such as egg yolk powder and egg white powder; dairy-derived materials such as skim milk powder and whey; oils and fats such as shortening, margarine, butter, powdered oils and fats, fat spreads, lard, salad oil, olive oil, and emulsified oils and fats; salt, 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, pH adjusters, preservatives, acidulants, etc. These raw materials may be used alone or in combination of two or more.

[0036] [Making of Bread] The bread of the present disclosure can be made by preparing dough using the ingredients described above and an appropriate amount of water, and then going through steps such as fermentation (primary fermentation), dividing, shaping, proofing (secondary fermentation), and baking.

[0037] 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.

[0038] [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.

[0039] [Specific Volume of Bread] The bread of the present disclosure has the characteristics of being well expanded and having a high specific volume, despite containing soy flour with a water-soluble nitrogen index of 70% or more. The specific volume of the bread of the present disclosure varies depending on the type of bread, the content of soy flour with a water-soluble nitrogen index of 70% or more, etc., but may be, for example, 2.00 to 5.50 mL / g, 2.40 to 5.00 mL / g, 2.40 to 4.80 mL / g, or 3.00 to 4.80 mL / g. In the present disclosure, the specific volume of bread is a value obtained by dividing the volume (mL) of bread measured by the rapeseed substitution method by the weight (g) of the bread.

[0040] 3. Bread Dough The present disclosure further provides a bread dough containing soy flour having a water-soluble nitrogen index of 70% or more and a reducing agent. The bread dough of the present disclosure is a dough used to produce the bread. The bread dough of the present disclosure may be in either a pre-fermentation state or a post-fermentation state.

[0041] The type and content of the soy flour with a water-soluble nitrogen index of 70% or more and the reducing agent contained in the bread dough of the present disclosure, as well as other ingredients, are as described in the section "2. Bread" above.

[0042] 4. Bread Mix The present disclosure further provides a bread mix containing soybean flour having a water-soluble nitrogen index of 70% or more and a reducing agent. 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.

[0043] The types and contents of soy flour and reducing agent having a water-soluble nitrogen index of 70% or more contained in the bread mix flour of the present disclosure, as well as other ingredients, are as described in the section "2. Bread" above.

[0044] 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.

[0045] The present disclosure will be specifically described below using examples, but the present invention is not limited to these examples.

[0046] Test Example 1 In this test example, tocopherol was added to dough containing 38% by mass, calculated as dry mass, of raw soybean flour with a water-soluble nitrogen index of 88%, and the degree of leavening of the bread was evaluated.

[0047] 1. Bread Production Dough was prepared using the specified amounts of ingredients shown in Table 1, and round bread was produced by floor time (primary fermentation), dividing and shaping (rounding), proofing (secondary fermentation), and baking. Specific production conditions are shown in Table 2.

[0048]

[0049]

[0050] 2. Evaluation method The volume, weight, and height of each piece of bread obtained were measured. The volume of the bread was measured using the rapeseed displacement method. The weight of the bread was measured using an electronic balance. The height of the bread was measured by placing the bread bottom side down and measuring the maximum height point with a ruler. The specific volume of the bread was calculated by dividing the weight (g) of the bread by the volume (mL) of the bread. The volume, weight, height, and specific volume of the bread were each measured for two samples, and the average value was calculated.

[0051] 3. Evaluation Results The results are shown in Table 3. When tocopherol was not added to dough containing raw soy flour with a water-soluble nitrogen index of 88%, the specific volume of the bread was small and the bread did not expand sufficiently upon baking (Comparative Example 1). In contrast, when tocopherol was added to dough containing raw soy flour with a water-soluble nitrogen index of 88%, the specific volume of the bread increased and sufficient expansion was observed (Examples 1 to 4). In particular, when the tocopherol content relative to the dry mass of the dough was 616 to 924 ppm, the specific volume of the bread was significantly larger and particularly excellent expansion was observed (Examples 2 and 3).

[0052]

[0053] Test Example 2 In this test example, the content of raw soybean flour (water-soluble nitrogen index: 88%) in the dough was changed to 0, 4.9, 10, or 19% by mass in dry mass equivalent, and the degree of leavening of the bread was evaluated. Specifically, round bread was produced and evaluated under the same conditions as in Test Example 1, except that the ingredients shown in Table 4 were used.

[0054] The results are shown in Table 5. In doughs that did not contain raw soy flour (water-soluble nitrogen index 88%), there was almost no difference in the specific volume of bread whether or not tocopherol was present (Comparative Examples 2 and 3). Furthermore, even when the raw soy flour (water-soluble nitrogen index 88%) content in the dough was 4.9, 10, or 19% by mass in dry mass terms, when tocopherol was added to the dough, an increase in the specific volume of bread was observed, and good leavening was observed (Examples 5 to 9). In particular, when the raw soy flour content in the dough was 10% by mass or more, the leavening-promoting effect of adding tocopherol was high.

[0055]

[0056]

[0057] Test Example 3 In this test example, catechins were added to dough containing raw soybean flour with a water-soluble nitrogen index of 88%, and the degree of leavening of the bread was evaluated. Specifically, round bread was produced and evaluated under the same conditions as in Test Example 1, except that the ingredients shown in Table 6 were used.

[0058] The results are shown in Table 7. Even when catechins were added to dough containing raw soy flour with a water-soluble nitrogen index of 88%, the specific volume of the bread increased, and good leavening was observed (Examples 10 and 11). Since the tocopherol used in Test Examples 1 and 2 and the catechins used in Test Example 3 are both components with reducing properties, the results of Test Examples 1 to 3 confirmed that adding a reducing agent to dough containing raw soy flour with a water-soluble nitrogen index of 88% resulted in good leavening of the bread.

[0059]

[0060]

[0061] Test Example 4 In this test example, flavonols (enzyme-treated rutin) or phenolic acid (ferulic acid) were added to dough containing raw soybean flour with a water-soluble nitrogen index of 88%, and the degree of leavening of the bread was evaluated. Specifically, round bread was produced and evaluated under the same conditions as in Test Example 1, except that the ingredients shown in Table 8 were used.

[0062] The results are shown in Table 9. Even when flavonols or phenolic acid were added to dough containing raw soy flour with a water-soluble nitrogen index of 88%, the specific volume of the bread increased, and good leavening was observed (Examples 12 and 13). Because the flavonols and phenolic acid used in Test Example 4 are components with reducing properties, the results of Test Examples 1 to 4 also confirmed that adding a reducing agent to dough containing raw soy flour with a water-soluble nitrogen index of 88% resulted in good leavening of the bread.

[0063]

[0064]

[0065] Test Example 5 In this test example, tocopherol and catechins were added to dough containing raw soybean flour with a water-soluble nitrogen index of 88%, and the degree of leavening of the bread was evaluated. Specifically, round bread was produced and evaluated under the same conditions as in Test Example 1, except that the ingredients shown in Table 10 were used.

[0066] The results are shown in Table 11. When a combination of tocopherol and catechins was added to dough containing raw soybean flour with a water-soluble nitrogen index of 88%, a further increase in the specific volume of the bread was observed.

[0067]

[0068]

[0069] Test Example 6 In this test example, tocopherol was added to dough containing soybean flour with a water-soluble nitrogen index of less than 70%, and the degree of leavening of the resulting bread was evaluated. Specifically, round bread was produced and evaluated under the same conditions as in Test Example 1, except that the ingredients shown in Table 12 were used.

[0070] The results are shown in Table 13. As a result, even when tocopherol was added to dough containing soy flour with a water-soluble nitrogen index of less than 70%, the specific volume of the bread could not be increased (Comparative Examples 8 to 11). In other words, these results show that the effect of adding a reducing agent such as tocopherol to increase the specific volume of bread is unique to the use of dough containing soy flour with a water-soluble nitrogen index of 70% or more.

[0071]

[0072]

Claims

1. Bread made from soy flour having a water-soluble nitrogen index of 70% or more and a dough containing a reducing agent.

2. The bread according to claim 1, wherein the reducing agent is at least one selected from the group consisting of vitamin E, catechins, flavonols, and phenolic acids.

3. The bread according to claim 1, wherein the soy flour having a water-soluble nitrogen index of 70% or more is contained in an amount of 2% by mass or more, calculated as a dry mass, per dry mass of the dough.

4. The bread according to claim 1 or 2, wherein the reducing agent is contained in an amount of 50 to 1150 ppm per dry mass of the dough.

5. The bread according to claim 3, wherein the reducing agent is contained in an amount of 50 to 1150 ppm per dry mass of the dough.

6. A method for producing bread, comprising the steps of: preparing dough containing soy flour having a water-soluble nitrogen index of 70% or more and a reducing agent; and fermenting and baking the dough obtained in the above step.

7. A bread dough comprising soy flour having a water-soluble nitrogen index of 70% or more and a reducing agent.

8. A bread mix containing soybean flour having a water-soluble nitrogen index of 70% or more and a reducing agent.

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