Method for producing protein-enhanced bread

Abstract

The present invention aims to provide breads that can maintain sufficient expansion and mouthfeel of the dough even when a large amount of powdered soy protein is added, and the gluten network of the breads is not inhibited. A method for producing protein-enhanced breads, the breads containing 5 to 20% by weight of vegetable protein relative to flour, the method comprising adding a powdered vegetable protein raw material that meets specific requirements to the bread dough as a source of vegetable protein.

Description

Technical Field

[0001] The present invention relates to a method for producing protein-enhanced bread. Background Art

[0002] Protein is a macromolecule with amphiphilic properties, so it has gelling, thickening and water retention properties. Powdered plant protein products such as soy protein isolate (SPI) containing high concentrations of protein do not contain water, so they are easier to circulate and store than liquid products. In addition, this product can be added to processed foods at high concentrations, so it is also widely used as a material for improving the physical properties of various processed foods.

[0003] For example, soybean protein has a balanced amino acid composition and has physiological functions such as lowering serum cholesterol. Therefore, soybean protein is used in nutritional and health foods that are expected to have nutritional and physiological functions.

[0004] According to the "White Paper on Aging Society 2014" published by the Cabinet Office of Japan, the population of people aged 65 and over has reached 29.58 million, a record high. One in five people is elderly, and a super-aged society (a society where the proportion of people aged 65 and over in the total population exceeds 21%) is approaching. Under such circumstances, the goal proposed in "Healthy Japan 21" promoted by the Ministry of Health, Labor and Welfare of Japan is to extend the healthy life span. The "healthy life span" mentioned here refers to the time spent in a lifetime without illness or disability, and is expressed by healthy life span (average independent time) = average life span - non-time time (time when health is impaired and cannot live independently).

[0005] In order to extend the healthy life span, it is essential to take in the necessary amount of nutrients. In particular, protein is an indispensable substance for maintaining life. It also plays various functions while building tissues. According to the "Japanese Nutrition Intake Standards" (2010 edition) presented by the Ministry of Health, Labor and Welfare, the recommended protein intake for elderly people over 70 years old is the same as that for ordinary adults, which is 60g per day. However, the elderly usually do not have many daily activities. Therefore, the appetite of the elderly decreases, and the dietary intake is reduced. Therefore, the elderly need to efficiently take in protein in a small amount.

[0006] Under such circumstances, food manufacturers make full use of the excellent nutritional and physiological functions of plant protein and strive to develop processed foods for the purpose of supplementing plant protein. As one type of such processed food, protein-enhanced bread has been developed.

[0007] Here, powdered vegetable protein raw materials such as soy protein isolate have a high protein content and are therefore suitable for increasing the protein content of breads. In addition, since the raw material is in a powdered form, it has the advantage of being able to be handled in the same manner as wheat flour. In addition, since the raw material does not contain a large amount of water like soy milk, the amount added to breads to increase the protein content is not limited to the amount of water allowed by the bread dough, which is also advantageous in this regard.

[0008] However, if a large amount of vegetable protein such as soy protein is added to bread dough in order to increase protein, the vegetable protein will rob the moisture in the bread dough due to its water retention and inhibit the gluten network of wheat flour. Therefore, breads with a large amount of vegetable protein tend to have a smaller specific volume and a worse taste. Therefore, it is difficult to obtain high-protein breads with sufficient specific volume and a soft taste.

[0009] Therefore, there is a need to provide a technology that does not reduce the specific volume of bread or deteriorate the texture even if a large amount of vegetable protein is added to bread.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 11-243844

[0013] Patent Document 2: International Publication No. WO2007 / 114129

[0014] Patent Document 3: Japanese Patent Application Publication No. 2009-142200

[0015] Patent Document 4: Japanese Patent Application Publication No. 2016-2059

[0016] Patent Document 1 describes a method for producing protein-enriched breads, characterized in that powdered soybean protein and xylanase are added to bread dough, and describes that this technique contributes to preventing a decrease in the specific volume of protein-enriched breads.

[0017] Patent Document 2 describes a powdered soybean protein raw material that contains magnesium salts such as magnesium oxide and is partially hydrolyzed by protease. As the powdered soybean protein raw material, the examples describe: a raw material with an NSI of 32 and a 0.22M TCA solubility of 11%, a raw material with an NSI of 17 and a TCA solubility of 10%, a raw material with an NSI of 45 and a TCA solubility of 10%, or a raw material with an NSI of 30 and a TCA solubility of 22%. It is described that this technology is effective for the production of baked goods such as protein-enhanced biscuits.

[0018] Patent Document 3 describes the mixing of soybean puffs (protein content 78% by weight) and a powdered soybean protein raw material into baked snack dough. The soybean puffs are texturized by an extruder, and the present technology is characterized by the use of soybean puffs.

[0019] Patent Document 4 describes a soybean protein raw material for protein enhancement of breads, wherein the soybean protein raw material is prepared by preparing a powdered soybean protein raw material into a paste containing 10 to 50% by weight, drying the paste by hot air at 100 to 250° C. until the moisture content is 15% by weight or less, and then powdering the paste again. It is also described that breads produced using the raw material contribute to preventing a decrease in the specific volume of the protein-enhanced breads. Summary of the invention

[0020] If one attempts to enhance the protein content and reduce the sugar content of bread by adding powdered vegetable protein raw materials to bread, it is still difficult to obtain the expansion and texture suitable for bread.

[0021] Therefore, an object of the present invention is to provide breads which can maintain sufficient expansion and texture of the dough even when a relatively large amount of powdered soybean protein is added, and which do not suppress the gluten network of the breads.

[0022] The present inventors have conducted intensive research and, as a result, have discovered a powdered vegetable protein raw material having specific characteristics. They have learned that the above-mentioned problems can be solved by adding the powdered vegetable protein raw material as a raw material for bread, and have completed the present invention.

[0023] That is, the present invention includes the following configurations.

[0024] (1) A method for producing protein-enriched bread, wherein the bread contains 5 to 20% by weight of vegetable protein based on flour, characterized in that:

[0025] Add a powdered vegetable protein raw material that at least meets the following requirements A) to C) to the bread dough as a source of vegetable protein:

[0026] A) the protein content in the solid component is 80% by weight or more;

[0027] B) the pH of the 10 wt% solution is pH 6 to 8;

[0028] C) Nitrogen solubility index (NSI) is below 30;

[0029] D) the solubility in 0.22M trichloroacetic acid is less than 10%; and

[0030] E) contains water-soluble legume polysaccharides, or alginic acid or a salt thereof.

[0031] (2) The method for producing bread according to (1) above, wherein the powdered vegetable protein raw material is selected from soybeans, peas and mung beans.

[0032] (3) The method for producing bread according to (1) or (2) above, wherein the protein content in the solid content of the powdered vegetable protein raw material is 85% by weight or more.

[0033] (4) The method for producing bread according to any one of (1) to (3) above, wherein the pH of a 10 wt % solution of the powdered vegetable protein raw material is 6.7 to 7.3.

[0034] (5) The method for producing bread according to any one of (1) to (4) above, wherein the nitrogen solubility index (NSI) of the powdered vegetable protein raw material is 25 or less.

[0035] (6) The bread according to any one of (1) to (5) above, wherein the powdered vegetable protein raw material has a calcium content of 0.5% by weight or less and a magnesium content of 0.25% or less in the solid content.

[0036] (7) The bread according to any one of (1) to (6) above, wherein the powdered vegetable protein raw material has a solubility in 0.22 M trichloroacetic acid of 5% or less.

[0037] (8) The bread according to any one of (1) to (7) above, wherein the polysaccharide contained in the powdered vegetable protein raw material is a water-soluble bean polysaccharide.

[0038] (9) The bread according to (8) above, wherein the water-soluble bean polysaccharide is water-soluble soybean polysaccharide or water-soluble pea polysaccharide.

[0039] According to the present invention, it is possible to obtain bread having the same texture and shape as conventional bread even if a relatively large amount of powdered vegetable protein raw material is added to form a high-protein bread. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present invention will be described in detail.

[0041] (Bread)

[0042] The "breads" in the present invention refer to, for example, flour bread, hot dog buns, Danish pastry, French bread, ciabatta, focaccia bread, Indian flatbread, pizza, bagels, English muffins, pies, pastry bread, yeast donuts, etc., but are not limited to this name, and include all types that are generally regarded as bread and its analogs.

[0043] Bread can be made according to conventional methods. Usually, raw materials mainly composed of flour such as wheat flour, whole wheat flour, rice flour, water, yeast, sugar, salt, oil, etc. are kneaded into dough, which is then formed into a desired shape and then baked in an oven or fried.

[0044] The order of adding the above ingredients when making bread dough can be a direct kneading method (direct method) in which all the ingredients are mixed together to make the dough, or a method such as the middle seed method or the soup seed method in which a part of the ingredients are first made into a seed dough and then the remaining ingredients are added to make the main dough.

[0045] The present invention shows a remarkable effect particularly in breads in which a gluten network is generated in the dough and then subjected to a fermentation step using yeast.

[0046] In addition, in this specification, the bread obtained by the production method of the present invention may be referred to as "the present bread".

[0047] (Plant Protein)

[0048] The bread contains at least 5 to 20% by weight of vegetable protein as a nutritional component relative to flour. Moreover, the higher the protein content, the more effectively the effect of the present invention can be exerted, so it is preferred, preferably 10% by weight or more. Vegetable protein has a tendency to inhibit the gluten network in bread dough, resulting in a decrease in specific volume and a deterioration in taste. This phenomenon greatly damages the commercial value of bread. On the other hand, in the present invention, even if a high amount of vegetable protein is contained, these problems can be solved.

[0049] Examples of the vegetable protein include proteins derived from beans such as soybeans, peas, mung beans, chickpeas, and cowpeas, and rapeseed seeds.

[0050] (Powdered vegetable protein raw material)

[0051] As the protein in the present bread, the present bread contains all or part of the above-mentioned protein raw material containing vegetable protein by adding it to the present bread. Here, in the manufacturing method of the present bread, the specific "powdered vegetable protein raw material" which will be described in detail below is an essential and important protein raw material.

[0052] Here, the term "powdered vegetable protein raw material" used in this specification refers to a food raw material that has a powdered product form and mainly contains protein derived from plants.

[0053] As a typical example, when the plant is soybean, defatted soybean flakes are used as soybean raw materials, which are dispersed in an appropriate amount of water for water extraction, and the insoluble part mainly composed of fiber is removed to obtain extracted soybean protein (defatted soybean milk). When the extracted soybean protein is made into a product, the powdered soybean protein raw material contains the extracted soybean protein. In addition, the extracted soybean protein is adjusted to about pH 4.5 with an acid such as hydrochloric acid, the protein isoelectric point precipitated to remove the acid soluble part (whey), and the acid insoluble part (curd) is dispersed again in an appropriate amount of water to obtain a curd slurry, which is neutralized with an alkali such as sodium hydroxide to obtain a neutralized slurry. If the soy protein isolate obtained from the neutralized slurry is made into a product, the powdered soy protein raw material will also contain the soy protein isolate.

[0054] After the solutions of the extracted soy protein and the soy protein isolate are sterilized by heating in a high temperature heating treatment device, the sterilized solution is spray dried by a spray dryer, etc., thereby making the powdered soy protein raw material into a final product. That is, the most typical powdered vegetable protein raw material is a powder of the spray-dried extracted protein or isolated protein.

[0055] However, the method is not limited to the above-mentioned production method, as long as it is a method for improving the purity of soybean protein from soybean raw materials. In addition, concentrated soybean protein obtained by removing whey from defatted soybeans using ethanol or acid is also included in the powdered soybean protein raw material. Among them, the protein content of soybean protein isolate is usually as high as about 90% by weight in the solid content. In this regard, soybean protein isolate is more commonly used than extracted soybean protein.

[0056] (Characteristics of powdered vegetable protein)

[0057] The specific powdered protein raw material used in the present bread must at least meet the requirements A) to E) below. It should be noted that in this specification, the powdered vegetable protein raw material added to the present bread is sometimes referred to as "the present powdered vegetable protein raw material". By kneading the present powdered vegetable protein raw material into bread dough, high-quality bread can be obtained that suppresses the decrease in volume and the deterioration in taste compared to ordinary breads despite being high in protein.

[0058] These requirements are described in more detail below.

[0059] A) Protein content in solid ingredients

[0060] The protein content in the solid content of the powdered vegetable protein raw material is at least 80% by weight, preferably 85% by weight or 90% by weight. The higher the protein content, the more low-sugar bread can be produced by adding a smaller amount, so it is preferred.

[0061] On the other hand, as the powdered vegetable protein raw material, in order to increase the protein content, the content of insoluble dietary fiber is preferably as low as possible, more preferably below 2% by weight, below 1% by weight, or below 0.5% by weight per unit dry matter. It should be noted that the content of insoluble dietary fiber is measured by the modified Prosky method according to the "Japanese Food Standard Composition Table Analysis Manual 5th Edition" (Food Composition Department of the Science and Technology Agency Resources Survey (Heisei 9)).

[0062] B) pH of 10 wt% solution

[0063] It is important that the pH of the powdered vegetable protein raw material is in the range of 6 to 8, preferably in the range of 6.5 to 7.5, and more preferably in the range of 6.7 to 7.3. If the pH of the powdered vegetable protein raw material is too high, it will be difficult to adjust the NSI of the requirement C) below to 30 or less. On the other hand, if the pH of the powdered vegetable protein raw material is too low, the flavor of bread tends to deteriorate, which is not preferred.

[0064] C) Nitrogen Solubility Index (NSI)

[0065] As an indicator of the solubility of the powdered vegetable protein raw material in water, it is important that the NSI (Nitrogen Solubility Index) is 30 or less. That is, low solubility in water is crucial. In a further preferred embodiment, the NSI may be 25 or less, 22 or less, or 20 or less. It should be noted that the NSI is expressed as the ratio (weight %) of water-soluble nitrogen (crude protein) to the total nitrogen content based on a prescribed method, and in the present invention, it adopts the value measured according to the following method.

[0066] If the NSI is too high, the water retention of the powdered vegetable protein raw material increases, thereby impairing the stretchability and expansion of the dough when added to bread dough.

[0067] It should be noted that when manufacturing the present powdered vegetable protein raw material, divalent metal salts such as calcium salts or magnesium salts can be added to react the protein with the divalent metal to reduce NSI. However, adding a large amount of calcium salts or magnesium salts to the present powdered vegetable protein raw material will make it difficult to obtain a powdered vegetable protein raw material that does not affect the formation of gluten in bread dough, and therefore, it may be difficult to obtain the desired quality when making bread dough.

[0068] Therefore, as a preferred embodiment, the calcium content in the solid component of the powdered vegetable protein raw material can be less than 0.5% by weight, and the magnesium content can be less than 0.25% by weight. The calcium content can further be less than 0.4% by weight, less than 0.3% by weight, or less than 0.2% by weight. The magnesium content can further be less than 0.2% by weight, less than 0.15% by weight, or less than 0.1% by weight. In addition, the powdered vegetable protein raw material can be a material to which no calcium salt or / and magnesium salt is added during manufacturing. It should be noted that the contents of calcium and magnesium are determined by formal atomic absorption spectrometry.

[0069] D) 0.22M trichloroacetic acid solubility

[0070] The present powdered vegetable protein raw material is characterized in that it is not hydrolyzed by protease. As an indicator of the lack of such hydrolysis, the 0.22M trichloroacetic acid soluble rate (hereinafter referred to as "TCA soluble rate") can be used. This value is obtained as follows: the powdered vegetable protein raw material is dispersed in water in a manner such that the protein content reaches 1.0% by weight and is fully stirred to obtain a dispersion, and the ratio of protein dissolved in 0.22M trichloroacetic acid to total protein is determined by the Kjeldahl method for the dispersion. The value of the TCA soluble rate increases as the protein hydrolysis proceeds.

[0071] The present powdered vegetable protein raw material is characterized in that its TCA solubility is less than 10%. In a certain embodiment, the upper limit of the TCA solubility may be less than 7%, less than 6%, or less than 5%. Breads manufactured using the present powdered vegetable protein raw material having a TCA solubility within this range can be given a preferred specific volume and mouthfeel. Powdered vegetable protein raw materials having a high TCA solubility, i.e., enzymatically hydrolyzed, are the main reason for the adverse effect on the specific volume of breads to which the raw material is added, which is not preferred in the manufacture of the present breads.

[0072] E) Water-soluble polysaccharides

[0073] The present powdered vegetable protein raw material is characterized in that it contains specific water-soluble polysaccharides. Here, “containing water-soluble polysaccharides” means that the water-soluble polysaccharides are contained in the present powdered vegetable protein raw material in a state where they are integrated with other components such as protein and cannot be physically separated, that is, in a complex state. In this regard, a substance formed by mixing powders of the powdered vegetable protein raw material and powdered water-soluble polysaccharides does not belong to the present powdered vegetable protein raw material. It should be noted that in the present specification, the specific water-soluble polysaccharides contained in the present powdered vegetable protein raw material are sometimes referred to as “the present water-soluble polysaccharides”.

[0074] The water-soluble polysaccharide is a water-soluble bean polysaccharide, or alginic acid or a salt thereof. As the water-soluble bean polysaccharide, water-soluble soybean polysaccharides or water-soluble pea polysaccharides are preferred. As alginic acid or a salt thereof, sodium alginate and potassium alginate can be cited.

[0075] By including the present water-soluble polysaccharide in the present powdered vegetable protein raw material, the present water-soluble polysaccharide may inhibit the three-dimensional structure of the vegetable protein, thereby having the effect of preventing the influence of the vegetable protein on the gluten formation of the bread dough.

[0076] Water-soluble soybean polysaccharides and water-soluble pea polysaccharides are water-soluble polysaccharides composed of sugars such as rhamnose, fucose, arabinose, xylose, galactose, glucose and uronic acid. The average molecular weight is 1 million or less according to the gel filtration HPLC method analyzed under the following conditions. These can be extracted from the raw materials containing insoluble dietary fiber (okara) of soybeans or peas with water by a known method, and the substances prepared by refining as needed. Water-soluble soybean polysaccharides can use commercial products, for example, "SOYAFIVE (R)" series (made by Fuji Oil (Co., Ltd.) and "SM" series (made by Sanrongyuan FMI (Co., Ltd.) can be used. In addition, water-soluble pea polysaccharides can also use commercial products, and in addition, substances obtained by methods described in, for example, International Publication WO2012 / 176852 and International Publication WO2014 / 103833 can also be used.

[0077] Gel filtration HPLC uses standard pullulan (Showa Denko K.K.) as a standard substance and uses an analytical column "TSKgel G5000PWXL" (manufactured by Tosoh Corporation, column size: 7.8 mm I.D. × 30 cm, filler base material: methacrylate polymer, filler particle size: 10 μm, exclusion limit molecular weight: 2.5 million). The average absolute molecular weight (MM) is obtained by passing the liquid through the column and then using a multi-angle laser scattering instrument (MALLS) calibrated with toluene. The eluent is, for example, a 50 mM sodium acetate aqueous solution (pH 5.0), the flow rate of the column is set to 1.0 mL / min, and the detectors are RI detectors and MALLS detectors. However, each analysis condition can be appropriately changed within a range that does not cause a large error in the analysis value.

[0078] Alginic acid or its salt is a water-soluble polysaccharide derived from seaweed, and a commercially available product can be used. As the salt, an alkali metal salt such as sodium or potassium is preferred.

[0079] In the solid content of the powdered vegetable protein raw material, the content of the water-soluble polysaccharide is preferably 0.5% by weight or more. In a further preferred embodiment, the content may be 0.5% by weight or more or 1% by weight or more. In a certain embodiment, the upper limit of the content may be 5% by weight or less, 4% by weight or less, or 3% by weight or less.

[0080] (Manufacture of powdered vegetable protein raw materials)

[0081] Below, soybeans are used as an example to illustrate a reference scheme for producing a powdered vegetable protein raw material that meets all of the requirements A) to E) of the present invention. However, the essence of the technical concept of the present invention is to use the present powdered vegetable protein raw material that meets the requirements A) to E) for the production of bread. Therefore, the method for producing the present powdered vegetable protein raw material is of course not limited to a specific plant type or a specific production scheme.

[0082] In order to produce the powdered soybean protein raw material, the process of producing the existing soybean protein isolate can be used as the basis. However, the method of concentrating the protein can be a method using ordinary acid precipitation, a concentration method using membrane filtration, or a method of extracting water from the concentrated soybean protein.

[0083] As a soybean raw material for extracting protein, defatted soybeans are generally used, but full-fat soybeans or partially defatted soybeans may also be used. When full-fat soybeans or partially defatted soybeans are used, high-speed centrifugation may be performed after the extraction step to remove the oil separated to the upper layer, thereby reducing the oil content.

[0084] Next, the soybean raw material is mixed with water and dispersed into a slurry state, and the protein is extracted while stirring as necessary.

[0085] Next, insoluble dietary fiber (okara) is removed from the slurry by separation means such as centrifugal filtration to obtain an extracted soybean protein solution (soy milk).

[0086] Next, the acid-soluble portion (whey) such as oligosaccharides and acid-soluble proteins is removed from the extracted soy protein solution to obtain a concentrated solution of soy protein. As a typical method, an acid precipitation method can be used, and the pH of the extracted soy protein solution is adjusted to near the isoelectric point of 4 to 5 with an acid such as hydrochloric acid or citric acid to insolubilize and precipitate the protein. Next, the acid-soluble portion is removed by separation methods such as centrifugation or filtration, and the "curd" as the acid-insoluble portion is recovered and dispersed again in an appropriate amount of water to obtain a curd slurry. It should be noted that as a method of concentrating soy protein other than the acid precipitation method, ultrafiltration and the like can be cited.

[0087] Next, the obtained curd slurry is finally adjusted to pH 7 to obtain a neutralized slurry. Next, heat sterilization is performed by at least one high-temperature heating treatment during all the steps. As the heating treatment, direct steam blowing high-temperature instantaneous heating treatment is preferred. The heating treatment is a UHT sterilization method, that is, high-temperature and high-pressure steam is directly blown into the soybean protein solution, heated and maintained, and then the pressure is quickly released in the vacuum flash tray. The heating treatment conditions are: 100-170°C, preferably in the range of 110-165°C; the heating time is 0.5 seconds to 5 minutes, preferably 1 second to 120 seconds. At this time, according to the pH adjusted to each stage of the manufacturing process, the solution or slurry containing the soybean protein to be heated is heated in the range of 3 to 12. A commercially available heating sterilization device using this heating treatment method can be used, and a VTIS sterilizer (made by Alfa Laval) and a jet cooking device can also be used. And finally, the sterilized solution is spray-dried with a spray dryer to obtain a powdered soybean protein raw material. As a method of drying with a spray dryer, a disk-type atomizer method or spray drying using a single-fluid or two-fluid nozzle can be used.

[0088] Here, in order to obtain a powdered soybean protein raw material that satisfies all of the requirements A) to E) of the present invention, the following steps may be optionally or necessarily employed.

[0089] As an optional embodiment, in the process of removing insoluble dietary fiber from the slurry after the extraction process to obtain the extracted soybean protein solution, in order to reduce the mixing of insoluble dietary fiber as much as possible, centrifugation can be performed for a long time or multiple times to remove the insoluble dietary fiber, so that the content of insoluble dietary fiber in the powdered soybean protein raw material of the final product is 1% by weight or less, preferably 0.5% by weight or less, and more preferably 0.2% by weight or less. As another scheme, it is also possible to choose not to add the above-mentioned process.

[0090] Adding the water-soluble polysaccharide is one of the necessary steps in the manufacturing process of the powdered vegetable protein raw material. In the manufacturing process of the powdered vegetable protein raw material, the water-soluble polysaccharide is added to the solution containing vegetable protein in the process before the spray drying process and mixed thoroughly, thereby achieving the addition of the water-soluble polysaccharide. As a result, the water-soluble polysaccharide is integrated with the powdered vegetable protein raw material and cannot be physically separated, thereby achieving compounding.

[0091] The present powdered vegetable protein raw material that satisfies all of the above requirements A) to E) can be obtained by purchasing from a manufacturer of the vegetable protein raw material, such as Fuji Oil Co., Ltd., or by entrusting the manufacturer to produce the powdered vegetable protein raw material.

[0092] In addition, Fuji Oil Co., Ltd. has tested and produced a new type of powdered plant protein raw material "Prolina CP01" (tentative name) series that possesses all of the above characteristics A) to E). Therefore, those skilled in the art can easily obtain the product or test samples if they specify this product. It should be noted that commercially available powdered soy protein raw materials such as the "Fuji pro" series, "New Fuji pro" series, and "Prolina" series do not meet all of the above characteristics A) to E). Therefore, even if these are used, they cannot be applied to the manufacturing method of this bread product.

[0093] (Measurement method)

[0094] The analytical values in the present invention follow the following measurement methods.

[0095] <pH measurement method>

[0096] Add 360 ml of ion-exchanged water at 25°C to 40 g of the sample, and stir with a homogenizing mixer for 5 minutes to completely dissolve it. Measure the resulting solution using an optional pH meter.

[0097] <NSI measurement method>

[0098] Add 60 ml of water to 3 g of the sample, stir with a paddle at 37°C for 1 hour, then centrifuge at 1400×g for 10 minutes to obtain the supernatant (I). Next, add 100 ml of water to the remaining precipitate again, stir with a paddle at 37°C for 1 hour, and then centrifuge to obtain the supernatant (II). Combine the (I) liquid and the (II) liquid, and add water to this mixture to make it reach 250 ml. After filtering it through a filter paper (NO. 5), measure the nitrogen content in the filtrate by the Kjeldahl method. At the same time, measure the nitrogen amount in the sample by the Kjeldahl method, and express the ratio of the nitrogen amount recovered as the filtrate (water-soluble nitrogen) to the total nitrogen amount in the sample as a percentage by weight, and use it as NSI.

[0099] Examples

[0100] Hereinafter, the embodiments of the present invention will be described in more detail by way of examples, etc. It should be noted that unless otherwise specified, "%" and "parts" in the examples represent "% by weight" and "parts by weight". In addition, all kinds of powdered protein raw materials used in the examples, etc. are all commercially available products and test-manufactured products made by Fuji Oil Co., Ltd.

[0101] ■Test materials

[0102] As samples of powdered soy protein raw materials, commercial product A of the normal undecomposed type without protease enzymolysis, commercial product B that has been enzymolyzed, and commercial products C and D that have been enzymolyzed and added with divalent metal salts were prepared. Next, a new trial product E "Prolina CP01" (tentative name) manufactured as a powdered soy protein raw material was prepared. All of these are powdered soy protein isolates obtained by extracting protein with water using defatted soybeans as raw materials and finally spray-drying them. They can be obtained by consulting Fuji Oil Co., Ltd.

[0103] The protein content in the solid content of these powdered soybean protein raw materials, the pH of a 10% solution, NSI, TCA solubility, calcium content, and magnesium content were analyzed. The analysis values ​​are shown in Table 1 below.

[0104] (Table 1)

[0105]

[0106] ■Test Example 2 (Tests T10 to T15)

[0107] As a control group, hot dog buns (C1) were prepared by the seed method without adding the test materials in Table 1 under the formulations in Table 2 and the production conditions in Table 3. Next, as test groups, hot dog buns (T1 to T5) were prepared using the powdered soybean protein raw materials of commercial products A to D and the trial product E under the formulations in Table 2 and the production conditions in Table 3.

[0108] (Table 2)

[0109] (Unit: copy)

[0110]

[0111] (Table 3)

[0112] <Zhongzhong> Trial production conditions

[0113]

[0114] <Formal dough kneading> Trial production conditions

[0115]

[0116] Measure the specific volume (cm) of each hot dog bun 3 / g), and then evaluate the operability during bread making.

[0117] In addition, 10 panelists who are experts in sensory evaluation of bread were asked to taste the hot dog buns from each test area to conduct sensory evaluations on the "texture of the bread" and "flavor of the bread."

[0118] The sensory method uses the following method: compare each test area with the control area, and give 1 point to the test area with the greatest difference in quality from the control area C1, 5 points to the test area with the closest quality to the control area C1, and give 1 to 5 points to the test areas with quality levels between the two through discussion by the judges based on the difference between 1 point and 5 points. In addition, for operability, the trial producers also evaluate with 1 to 5 points.

[0119] The results are shown in Table 4, and based on these results, it was comprehensively judged whether each powdered protein raw material was qualified as a raw material for bread making.

[0120] (Table 4)

[0121]

[0122] (Table 5)

[0123]

[0124] (Inspection)

[0125] As shown in Tables 4 and 5, the test area T5, which only added the trial product E as the powdered soybean protein raw material, had bread quality that was not inferior to that of the control area C1 in terms of operability, specific volume, taste after baking, and flavor, even when a large amount of protein was added.

[0126] The breads containing commercially available products A to D as powdered soy protein raw materials had significant differences from those of the control area C1 in terms of the extensibility and specific volume of the bread dough during the mixing stage, the texture and flavor of the bread after baking, and were of poor quality.

Claims

1. A method for producing protein-enriched bread, wherein the bread comprises 5 to 20% by weight of vegetable protein relative to flour, characterized in that: Add a powdered vegetable protein raw material that meets at least the following requirements A) to E) to the bread dough as a source of vegetable protein: A) the protein content in the solid component is 80% by weight or more; B) pH of 10 wt% solution is pH 6.7-7.3; C) Nitrogen solubility index NSI is below 30; D) The solubility in 0.22M trichloroacetic acid is less than 5%; and E) contains water-soluble legume polysaccharides, or alginic acid or a salt thereof, The powdered vegetable protein raw material has not been enzymatically hydrolyzed by proteases.

2. The method for producing bread according to claim 1, wherein: The powdered vegetable protein raw material is selected from soybeans, peas and mung beans.

3. The method for producing bread according to claim 1 or 2, wherein: The protein content of the powdered vegetable protein raw material in the solid content is 85% by weight or more.

4. The method for producing bread according to claim 1 or 2, wherein: The powdered vegetable protein raw material has a nitrogen solubility index (NSI) of 25 or less.

5. The method for producing bread according to claim 3, wherein: The powdered vegetable protein raw material has a nitrogen solubility index (NSI) of 25 or less.

6. The method for producing bread according to any one of claims 1, 2 or 5, wherein: The powdered vegetable protein raw material has a calcium content of 0.5% by weight or less and a magnesium content of 0.25% or less in the solid content.

7. The method for producing bread according to claim 3, wherein: The powdered vegetable protein raw material has a calcium content of 0.5% by weight or less and a magnesium content of 0.25% or less in the solid content.

8. The method for producing bread according to claim 4, wherein: The powdered vegetable protein raw material has a calcium content of 0.5% by weight or less and a magnesium content of 0.25% or less in the solid content.

9. The method for producing bread according to claim 1, wherein: The water-soluble bean polysaccharide is water-soluble soybean polysaccharide or water-soluble pea polysaccharide.

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