Heat-treated wheat flour production method and heat-treated wheat flour

Abstract

The present invention provides a heat-treated wheat flour production method in which 100 parts by mass of wheat flour, at least one substance selected from among (1) pH adjusting materials, (2) sugars and / or sugar alcohols, and (3) enzymes, and more than 30 parts by mass but not more than 40 parts by mass of water having a temperature of 70-100°C are combined to obtain a mixture, and said mixture is heated. The (3) enzyme is preferably at least one enzyme selected from among amylolytic enzymes and lipolytic enzymes. It is preferable for the mixture to be heated for 3-60 seconds at an ambient temperature of not less than 100°C but less than 120°C.

Description

Method for producing heat-treated wheat flour and heat-treated wheat flour

[0001] The present invention relates to a method for producing heat-treated wheat flour and heat-treated wheat flour.

[0002] Various methods have been known for producing heat-treated flour for use in bakery foods, etc. For example, Patent Document 1 describes a method for producing heat-treated wheat flour in which wheat flour is added with 20 to 55% water and heated for 83 to 60 seconds at an ambient temperature of 80 to 120°C to reach a temperature of 80 to 100°C, and then pulverized. This document also describes heat-treated wheat flour with a gluten vitality of 50 to 90, where the gluten vitality of the untreated base flour is taken as 100.

[0003] Patent Document 2 describes a method for producing a food material, which comprises mixing flour or starch with fats and oils, reacting lipase with the flour or starch in a pseudo-powder state with a predetermined moisture content and fat and oil content, and hydrolyzing the fat and oil to produce a food material composed of the reaction mixture.

[0004] Patent Document 3 describes a method for producing heat-treated wheat flour, which includes a step of mixing wheat flour with one or more carbohydrates selected from the group consisting of oligosaccharides and sugar alcohols, and subjecting the mixture to a moist heat treatment, wherein the oligosaccharides are trehalose and maltotriose, and the sugar alcohol is sorbitol, and the moist heat treatment is a treatment in which the mixture, to which water has been added, is placed in a sealed container at an ambient temperature of 100 to 120°C for 3 to 60 seconds, and the amount of water added is 5 to 20% by mass of the mixture.

[0005] WO2021 / 095827A1 JP 2015-107097 A Patent Publication No. 2017-175954

[0006] However, in the prior art, including Patent Documents 1 to 3, sufficient consideration has not been given to the composition of heat-treated wheat flour that can provide a moist and chewy texture (hereinafter simply referred to as "moist and chewy") when bakery foods are prepared, while suppressing deterioration in texture due to long-term freezing depending on the type of bakery food.

[0007] The present invention relates to the following: [1] A method for producing heat-treated wheat flour, comprising combining 100 parts by mass of wheat flour, at least one secondary ingredient selected from the following (1), (2), and (3), and more than 30 parts by mass and not more than 40 parts by mass of water at 70°C or higher and 100°C or lower, and heating the mixture. (1) pH-adjusting ingredient (2) sugar and / or sugar alcohol (3) enzyme

[0008] [2] A method for producing heat-treated wheat flour, comprising combining 100 parts by mass of wheat flour, a pH adjusting material, and more than 30 parts by mass and not more than 40 parts by mass of water at 70°C or higher and 100°C or lower to obtain a mixture, and heating the mixture.

[0009] [3] A method for producing heat-treated wheat flour, comprising: combining 100 parts by mass of wheat flour, sugar and / or sugar alcohol, and more than 30 parts by mass and 40 parts by mass or less of water at 70°C or higher and 100°C or lower to obtain a mixture; and heating the mixture.

[0010] [4] A method for producing heat-treated wheat flour, comprising combining 100 parts by mass of wheat flour, an enzyme, and more than 30 parts by mass and not more than 40 parts by mass of water at 70°C or higher and 100°C or lower to obtain a mixture, and heating the mixture.

[0011] [5] A method for producing heat-treated wheat flour, comprising combining 100 parts by mass of wheat flour, a pH adjusting material, sugar and / or sugar alcohol, an enzyme, and more than 30 parts by mass and not more than 40 parts by mass of water at 70°C or higher and 100°C or lower to obtain a mixture, and then heating the mixture.

[0012] [6] A method for producing heat-treated wheat flour according to any one of [1] to [5], wherein the mixture is heated at an ambient temperature of 100°C or higher but lower than 120°C for 3 seconds or longer and 60 seconds or shorter.

[0013] [7] Heat-treated wheat flour that is (i), (ii), (iii), or (iv) below: (i) The amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 66 mg or more and 76 mg or less, and the gluten vitality is 22 or more and 50 or less, where the gluten vitality of the untreated wheat flour is 100.

[0014] (ii) Heat-treated wheat flour in which the amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 79 mg or more and 193 mg or less, and when the amount of eluted sugar (mg) is (A), and the amount of eluted sugar (mg) per 1 g of heat-treated wheat flour after heat-treating the wheat flour and adding secondary ingredients is (B), (A) / (B) x 100(%) is 63% or more and 83% or less.

[0015] (iii) Heat-treated wheat flour in which the amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 77 mg or more and 145 mg or less, and the ratio (A) / (C) is 5 or more and 18 or less, where (A) is the amount of eluted sugar (mg) and (C) is the amount of reducing ends as glucose per 1 g of heat-treated wheat flour.

[0016] (iv) Heat-treated wheat flour having an amount of dissolved sugar (mg) per 1 g of heat-treated wheat flour of 58 mg or more and 69 mg or less, and a degree of complex formation by iodine colorimetry of 27% or more and 81% or less.

[0017] (v) The heat-treated wheat flour according to (i), having a pH of 5 or more and 6 or less.

[0018] [8] Heat-treated wheat flour obtained by combining 100 parts by mass of wheat flour, a secondary ingredient selected from the following (1), (2), and (3), and water at a temperature of 70°C to 100°C, and then heating the mixture: (1) pH-adjusting ingredient (2) sugar and / or sugar alcohol (3) enzyme

[0019] The present invention will be described below based on preferred embodiments. In this specification, heat-treated wheat flour refers to wheat flour that has been subjected to heat treatment.

[0020] First, we will explain the method for producing heat-treated wheat flour of the present invention. This method for producing heat-treated wheat flour involves combining 100 parts by mass of the wheat flour of the present invention with at least one secondary ingredient selected from the following (1), (2), and (3), and more than 30 parts by mass and up to 40 parts by mass of water at 70°C or higher and 100°C or lower to obtain a mixture, and then heating the mixture. (1) pH-adjusting ingredient (2) sugar and / or sugar alcohol (3) enzyme The present invention also encompasses the use of any of the above (1), (2), and (3) as essential ingredients. Hereinafter, when simply referring to a secondary ingredient, it refers to any of (1), (2), and (3).

[0021] One of the features of the method for producing heat-treated wheat flour of the present invention is that it involves combining water heated to a predetermined temperature or higher with wheat flour and the aforementioned specific auxiliary ingredients to obtain a mixture, and then subjecting the mixture to heat treatment. Hereinafter, the process of combining water, wheat flour, and the auxiliary ingredients to obtain a mixture is also referred to as a mixing process. In the present invention, heat-treating a mixture of wheat flour and the auxiliary ingredients with water heated to a predetermined temperature or higher is believed to have the following advantages over mixing unheated water with wheat flour and the auxiliary ingredients. (1) When a pH-adjusting ingredient is used, as described below, the acidic ingredient promotes hydrolysis of starch sugar chains, and the alkaline ingredient promotes gelatinization by dissociating hydrogen bonds between starch sugar chains. These promotion effects are further enhanced by increasing the temperature of the treated object. (2) When a sugar or sugar alcohol is used, as described below, the sugar or sugar alcohol enters the starch sugar chains and forms a complex, forming a steric hindrance, which is thought to inhibit recrystallization and syneresis in the starch sugar chains. The formation of this complex is promoted by increasing the temperature of the treated object. (3) When an amylolytic enzyme is used, the amylolytic reaction is accelerated by increasing the temperature of the treatment target, whereas when a lipolytic enzyme is used, the formation of a complex between lipid hydrolysates and starch is accelerated by increasing the temperature of the treatment target.

[0022] The temperature of the water is 70° C. or higher, preferably 75° C. or higher, and more preferably 80° C. or higher. By mixing the water with wheat flour at a temperature of 70° C. or higher, the starch in the wheat flour is sufficiently gelatinized, resulting in a bakery food with an excellent moist and chewy texture and suppressing changes in the texture over time. The water temperature referred to in this specification is the water temperature under normal pressure, and the upper limit is usually 100° C.

[0023] In the method for producing heat-treated wheat flour of the present invention, a predetermined amount of water is mixed with wheat flour during the mixing process. The amount of water mixed with wheat flour must be more than 30 parts by mass and not more than 40 parts by mass per 100 parts by mass of wheat flour. For example, Patent Document 3 states that it is preferable to add 20% by mass or less of water to a mixture of wheat flour and sugar alcohols, etc. In contrast, in the present invention, by increasing the amount of water to more than 30 parts by mass per 100 parts by mass of wheat flour, the degree of starch gelatinization is increased, thereby improving freeze resistance. On the other hand, by setting the amount of water to 40 parts by mass or less, the efficiency of drying and grinding during production is improved, thereby ensuring productivity. From these perspectives, it is particularly preferable that the amount of water mixed with wheat flour be more than 30 parts by mass and not more than 37.5 parts by mass per 100 parts by mass of wheat flour.

[0024] Next, the secondary ingredients used in the present invention will be described. The present inventors have surprisingly found that by heat-treating a mixture of water in the above-mentioned specific amounts at the specific temperatures, wheat flour, and the specific secondary ingredients, the moist and chewy texture of bakery foods is improved compared to when no secondary ingredients are added, and that deterioration in texture due to freezing can be effectively suppressed even in bakery foods such as pancakes that tend to become brittle when frozen for long periods of time.

[0025] The following describes the case where the secondary ingredient used in the present invention is (1) a pH-adjusting ingredient. Examples of pH-adjusting ingredients include organic acids and alkalis. Examples of organic acids include organic carboxylic acids (particularly divalent or higher organic carboxylic acids) having a hydroxyl group, such as citric acid, malic acid, tartaric acid, and lactic acid, ascorbic acid, acetic acid, succinic acid, and fumaric acid, as well as food ingredients containing these. Examples of alkalis include carbonates such as sodium carbonate and potassium carbonate, and food ingredients containing these as main components, such as brine and calcined calcium. Among these, organic acids, particularly citric acid, malic acid, and ascorbic acid, and food ingredients containing these, are preferred, with citric acid being the most preferred, due to their excellent effect of improving the texture of bakery foods and imparting freeze resistance.

[0026] When a food material containing an organic acid or alkali, rather than an organic acid or alkali itself, is used as the pH-adjusting material, the amount of organic acid or alkali in the food material is preferably 0.9% by mass or more, and more preferably 1% by mass or more.

[0027] In the present invention, by mixing a predetermined amount of water at a predetermined temperature and a pH-adjusting material with wheat flour and then heat-treating the mixture, the moist and chewy texture is improved and the freezing resistance is increased compared to heat-treating without the addition of any secondary material. Furthermore, in this embodiment, as shown in a comparison between Reference Example 1 and Example 4 described below, the moist and chewy texture and freezing resistance are superior to those obtained when the pH-adjusting material is not added during heat-treatment but is added to and mixed with wheat flour after heat-treatment. The reasons for this are unclear, but from the perspective of the decomposition and gelatinization of starch sugar chains, one possible reason is that the high temperature and high hydration conditions during heat-treatment of wheat flour and the pH-adjusting material promote hydrolysis of starch sugar chains by the acidic material and gelatinization due to the dissociation of hydrogen bonds between starch sugar chains by the alkaline material.

[0028] (1) The amount of pH-adjusting material used is preferably 0.01 parts by mass or more per 100 parts by mass of wheat flour, as this makes it easier to achieve the above-mentioned effects of using the pH-adjusting material, and more preferably 0.025 parts by mass or more. Furthermore, from the perspective of the degree of protein denaturation, it is preferable to set the blending amount to a specific amount or less, as this prevents the acidity or alkalinity of the pH-adjusting material from denaturing the protein and causing a brittle texture. From this perspective, the amount of pH-adjusting material used is preferably 1.0 part by mass or less per 100 parts by mass of wheat flour, and more preferably 0.1 part by mass or less. The preferred amount of secondary material used here is the preferred amount of dry mass of the secondary material if the secondary material is not in a solid form such as a powder (the same applies to the preferred amounts of secondary materials used in (2) and (3) described below).

[0029] (1) The amount of the pH-adjusting material used is preferably 0.00025 parts by mass or more, more preferably 0.0007 parts by mass or more, and particularly preferably 0.025 parts by mass or more, based on the amount of organic acid or alkali per 100 parts by mass of wheat flour, in order to facilitate the achievement of the above-mentioned effects of using the pH-adjusting material. On the other hand, the upper limit of the amount of the pH-adjusting material used is preferably 1.0 part by mass or less, and more preferably 0.1 part by mass or less, based on the amount of organic acid or alkali per 100 parts by mass of wheat flour, in order to prevent excessive denaturation of proteins.

[0030] The following describes the case where the secondary ingredient used in the present invention is (2) a sugar or sugar alcohol. Examples of sugars in (2) a sugar or sugar alcohol include monosaccharides such as glucose, xylose, ribose, and arabinose, and disaccharides and oligosaccharides such as maltose, sucrose, trehalose, and palatinose. Examples of sugar alcohols include sorbitol, mannitol, maltitol, erythritol, and xylitol. Among these, at least one selected from monosaccharides, disaccharides, and sugar alcohols is preferred, with monosaccharides and disaccharides being particularly preferred, due to their excellent effects of improving the texture of bakery foods and imparting freeze resistance. Specifically, at least one selected from glucose, xylose, maltose, and maltitol is preferred, with maltose being most preferred, due to their excellent effects of improving the texture of foods and imparting freeze resistance.

[0031] In this embodiment, by mixing a predetermined amount of water at a predetermined temperature and a sugar or sugar alcohol with wheat flour and heat-treating the mixture, the moist and chewy texture is improved and the freezing resistance is increased compared to heat-treating without adding any secondary ingredients. Furthermore, in this embodiment, as compared to when sugar or sugar alcohol is not added during heat-treatment but is added to wheat flour after heat-treatment, as shown in a comparison between Reference Example 2 and Example 13 described below, the moist and chewy texture and freezing resistance are superior to when sugar or sugar alcohol is added to wheat flour after heat-treatment without being added during heat-treatment. The reasons for this are not clear, but the inventors speculate that this may be because the addition of a large amount of water at a predetermined high temperature during heat-treatment causes sugar or sugar alcohol to enter and complex with the sugar chains of gelatinized starch, forming steric hindrance, which leads to recrystallization of the starch sugar chains and suppression of syneresis.

[0032] (2) The amount of sugar or sugar alcohol used is preferably 1.0 part by mass or more, more preferably 3.0 parts by mass or more, per 100 parts by mass of wheat flour, since the above-mentioned effects of using sugar or sugar alcohol are easily obtained. On the other hand, the upper limit of the amount of sugar or sugar alcohol used is preferably 20.0 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass of wheat flour, since this suppresses the brittle texture of wheat flour products resulting from a high sugar content.

[0033] The following describes the case where the secondary ingredient is (3) an enzyme. Examples of enzymes include amylase, a starch-degrading enzyme, and phospholipase and lipase, which are lipid-degrading enzymes. Known starch-degrading enzymes include α-amylase, β-amylase, amyloglucosidase, G4 amylase, glucosyltransferase, pullulanase, maltotriohydrolase, cyclodextrin glucanotransferase, transglucosidase, and 4-α-glucanotransferase, and these amylase-containing food materials can also be used. For example, malt-derived food materials have α-amylase activity and β-amylase activity. Examples of malt-derived food materials include malt powder and malt syrup. While any of these may be used in the present invention, the use of α-amylase, G4 amylase, or a food material containing these is preferred due to their excellent texture-improving effect, and the use of α-amylase or a food material containing it is even more preferred.

[0034] For example, amyloglucosidases include those available under the trade name "GoldCrust 3300BG" manufactured by Novozymes, which are also known as glucoamylases or glucan 1,4-α-glucosidases (EC 3.2.1.3), and which catalyze the hydrolysis of terminal (1,4)-linked α-D-glucose residues consecutively from the non-reducing end. The G4 amylase may be an enzyme (EC 3.2.1.60, also known as Glucan 1,4-alpha-maltotetraohydrolase) that has the activity of hydrolyzing the α(1→4)-glucan structure of a polysaccharide such as amylose to generate maltotetraose units from the non-reducing end. Examples of the G4 amylase include "POWERFresh 3050 GF" (manufactured by Danisco Japan Co., Ltd.), trade name "POWERFresh 3150" (manufactured by Danisco Japan Co., Ltd.), trade name "POWERFresh 4150" (manufactured by Danisco Japan Co., Ltd.), trade name "POWERSoft 7033" (manufactured by Danisco Japan Co., Ltd.), and the like, as well as "Denabake (registered trademark) EXTRA" (manufactured by Nagase ChemteX Corporation). α-Amylase (enzyme code: EC 3.2.1.1) is a general term for endo-type enzymes that randomly cleave α-1,4 bonds in starch, glycogen, etc. Examples include Spitase CP3 and Spitase L (both manufactured by Nagase ChemteX Japan Corporation), Coclase (manufactured by Mitsubishi-Kagaku Foods Corporation), Biozyme A, Clystase L1, Amylase AD "Amano" 1 (manufactured by Amano Enzyme Inc.), Fungamyl (registered trademark) 4000 SG, and Fungamyl 800L (manufactured by Novozymes). β-Amylase is an exo-type enzyme that cleaves α-1,4 bonds from the non-reducing end of starch, glycogen, etc., into maltose units. Known β-amylases include β-amylase F "Amano" (manufactured by Amano Enzyme Inc.), β-amylase #1500S (trade name; manufactured by Nagase ChemteX Corporation), and Hi-Maltosin G (trade name; manufactured by HIV Corporation). The optimum temperature of the starch-degrading enzyme is preferably 27°C or higher, more preferably 50°C or higher, and even more preferably 60°C or higher.

[0035] Among lipolytic enzymes, known phospholipases include enzymes that hydrolyze the ester bonds of phospholipids, such as phospholipase A1, phospholipase A2, and phospholipase B, and phosphodiesterases, such as phospholipase C and phospholipase D. Known lipases include various enzymes that hydrolyze the ester bonds of triglycerides. Regarding position specificity for fats and oils, lipases are known to include those that specifically hydrolyze the ester bonds at the 1- and 3-positions of triglycerides, those that specifically hydrolyze the ester bond at the 2-position of triglycerides, and those that do not have position specificity for fats and oils. Furthermore, both phospholipases and lipases are known to include those that have chain length specificity for the fatty acids to be hydrolyzed and those that do not. In the present invention, lipase is preferably used as the lipolytic enzyme because it has excellent texture-improving effects and freezing resistance when used in bakery foods, and in particular, lipases having position specificity for the 1,3 positions of triglycerides or chain length specificity for short- or medium-chain fatty acids are preferred, and those having position specificity for the 1,3 positions of triglycerides and chain length specificity for short- or medium-chain fatty acids are particularly preferred. Note that chain length specificity for short- or medium-chain fatty acids refers to the property of easily hydrolyzing fatty acids having 12 or fewer carbon atoms, for example, compared to fatty acids having 18 or more carbon atoms.

[0036] Lipases that can be suitably used include those produced by microorganisms of the genus Rhizopus, Aspergillus, and Mucor. For example, among commercially available lipolytic enzyme preparations, lipases that are considered to have position specificity for the 1,3-positions of triglycerides include Lipase A5 (manufactured by Nagase ChemteX Corporation), Lipase AS "Amano" (Amano Enzyme Inc.), and Lipase M "Amano" 10 (Amano Enzyme Inc.), and lipases that have position specificity for the 1,3-positions of triglycerides and chain length specificity for short- or medium-chain fatty acids include Lipase A5 (manufactured by Nagase ChemteX Corporation) and Lipase AS "Amano" (Amano Enzyme Inc.). Lipases that have no specificity for fat or oil positions or chain length can also be used, such as Lipase AY "Amano" 30SD manufactured by Amano Enzyme Co., Ltd. Known phospholipases include Denabake RICH (manufactured by Nagase ChemteX Corporation) and PLA2 Nagase 10P / R (manufactured by Nagase ChemteX Corporation). The optimum temperature for the lipolytic enzyme is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher.

[0037] In the present invention, by mixing a predetermined amount of water at a predetermined temperature with an amylolytic enzyme or lipolytic enzyme and wheat flour and then heat-treating the mixture, the moist and chewy texture is improved and freezing resistance is increased compared to heat-treating without adding any secondary ingredients. Furthermore, as shown in the comparison between Reference Example 3 and Example 20, and between Reference Example 4 and Example 25, the moist and chewy texture and freezing resistance are superior to those when the amylolytic enzyme or lipolytic enzyme is not added during heat-treatment but is added to wheat flour after heat-treatment. The reasons for this are unclear, but the inventors speculate that this is because, for the amylolytic enzyme, gelatinized starch, which is susceptible to enzymatic degradation, coexists with the amylolytic enzyme, resulting in appropriate starch degradation, during the period from mixing wheat flour with the enzyme to enzyme inactivation due to temperature rise. For the lipolytic enzyme, the gelatinized starch, which is susceptible to forming a complex with the lipid degradation products of wheat flour, coexists, facilitating the formation of the complex.

[0038] (3) The amount of enzyme used is preferably 0.01 parts by mass or more per 100 parts by mass of wheat flour, since the above-mentioned effects of using the enzyme are easily obtained. On the other hand, the upper limit of the amount of enzyme used is preferably 1.00 parts by mass or less per 100 parts by mass of wheat flour, from the viewpoint of cost-effectiveness with respect to the blending amount.

[0039] In particular, when the enzyme is a starch-degrading enzyme, in order to obtain a particularly excellent texture improving effect, the amount is more preferably 0.01 parts by mass or more and 1.00 parts by mass or less, and even more preferably 0.05 parts by mass or more and 0.50 parts by mass or less, per 100 parts by mass of wheat flour.

[0040] Furthermore, when the enzyme is a lipolytic enzyme, in order to obtain a particularly excellent effect of improving texture, it is more preferable that the amount be 0.01 parts by mass or more and 1.0 parts by mass or less, and even more preferable that the amount be 0.05 parts by mass or more and 0.5 parts by mass or less, per 100 parts by mass of wheat flour.

[0041] In addition, even when the present invention uses a material containing an enzyme as the enzyme, the dry mass of the material is more preferably 0.01 parts by mass or more and 1.0 parts by mass or less, and even more preferably 0.05 parts by mass or more and 0.5 parts by mass or less, per 100 parts by mass of wheat flour.

[0042] When using starch-degrading enzymes or food ingredients containing them, the preferred amount of activity of α-amylase to be added is, for example, 70 U to 7000 U per 100 g of flour, preferably 350 U to 3500 U. The preferred amount of activity of β-amylase to be added is, for example, 6.5 U to 650 U per 100 g of flour, preferably 32.5 U to 325 U. The preferred amount of activity of G4 amylase to be added is, for example, 65 U to 6500 U per 100 g of flour, preferably 325 U to 3250 U. The preferred amount of activity of amyloglucosidase to be added is, for example, 3.3 to 3300 U per 100 g of flour, preferably 16.5 to 1650 U. The enzyme activity of α-amylase is based on the titer of 7000 U / g of Amano Enzyme's product, Biozyme A. The enzymatic activity of α-amylase is based on the product "β-Amylase F 'Amano'" (trade name, manufactured by Amano Enzyme Co., Ltd.) with a titer of 650 U / g. The enzymatic activity of G4 amylase is based on the product "Denabake® EXTRA" (trade name, manufactured by Nagase ChemteX Corporation) with a titer of 6500 U / g. The enzymatic activity of amyloglucosidase is based on the product "GoldCrust 3300BG" (trade name, manufactured by Novozymes) with a titer of 3300 U / g. The activity can be measured using a standard method commonly used in the art. For example, the activity of α-amylase can be measured based on the amount of sugar produced using starch as a substrate at pH 5.0 and 40°C for 20 minutes, which is then colored with an iodine solution. For example, the enzymatic activity of β-amylase can be measured based on the amount of maltose produced using starch as a substrate at pH 5.0 and 40°C for 20 minutes. For example, the enzymatic activity of G4 amylase can be determined based on the reducing power equivalent to the glucose produced in 1 minute using soluble starch as a substrate at pH 7.0 and 40° C. For example, the enzymatic activity of amyloglucosidase can be determined based on the amount of glucose produced in 20 minutes using starch as a substrate at pH 5.0 and 40° C.

[0043] The preferred amount of activity of a lipolytic enzyme to be added is preferably 25 U to 2,500 U, more preferably 125 U to 1,250 U, per 100 g of flour for non-position-specific lipases. For position-specific lipases, the preferred amount is 1,000 U to 120,000 U, more preferably 5,000 U to 60,000 U, per 100 g of flour. For example, the activity of a non-position-specific lipase can be defined as 2,500 U per 1 g of Lipase AY "Amano" 30SD manufactured by Amano Enzyme Inc. The activity of a position-specific lipase can be defined as 100,000 to 120,000 U per 1 g of Lipase A5 (manufactured by Nagase ChemteX Corporation) described in the Examples below. A common method used in the art can be used to measure activity. For example, when the substrate is a triglyceride having palmitic acid, eicosapentaenoic acid, or docosahexaenoic acid as a side chain, the amount of palmitic acid, eicosapentaenoic acid, or docosahexaenoic acid produced by substrate decomposition at a temperature of 37°C and pH 7.0 within a predetermined time (e.g., 20 minutes for a non-position-specific lipase, or 60 minutes for a position-specific lipase) can be used.

[0044] In the mixing process, the mixture of flour, water, and auxiliary ingredients does not need to be a homogeneous mixture, as long as it is in a mixed state. Furthermore, in this specification, the mixing process of flour, water, and auxiliary ingredients to obtain a mixture of flour, water, and auxiliary ingredients does not require a homogenization operation such as stirring. However, homogenization operations such as stirring when obtaining a mixture of flour, water, and auxiliary ingredients are not excluded from the present invention, and can be performed as appropriate depending on the intended use, quality, etc. of the heat-treated flour desired.

[0045] Methods for obtaining a mixture of wheat flour, water, and auxiliary ingredients include mixing wheat flour with the auxiliary ingredients and then mixing water, adding the auxiliary ingredients to water and then mixing wheat flour, mixing wheat flour with water and then mixing the auxiliary ingredients, and simultaneously mixing wheat flour, water, and auxiliary ingredients. Any of these methods may be used in the present invention, but when the auxiliary ingredient is (3) an enzyme, it is preferable to mix it with wheat flour before heat treatment and then mix the water and the enzyme-mixed wheat flour, rather than dissolving it directly in water (70 to 100°C), from the viewpoint of maintaining the enzyme activity as long as possible during heat treatment.

[0046] In the production method of the present invention, at least one secondary ingredient selected from (1) a pH-adjusting ingredient, (2) a sugar or sugar alcohol, and (3) an enzyme may be used, but a combination of multiple ingredients is preferred. In particular, from the viewpoint of obtaining a significant effect of improving texture, it is preferred to use all of (1) a pH-adjusting ingredient, (2) a sugar or sugar alcohol, and (3) an enzyme, and it is even more preferred to use all of (1) a pH-adjusting ingredient, (2) a sugar or sugar alcohol, and (3) an enzyme, and to use a starch-degrading enzyme and a lipolytic enzyme in combination as the (3) enzyme.

[0047] For example, when components (1) and (2) are used in combination, a suitable mass ratio is (1) pH adjusting material:(2) sugar or sugar alcohol, which is 1:20 to 1000. When components (1) and (3) are used in combination, a suitable mass ratio is (1) pH adjusting material:(3) enzyme, which is 1:0.01 to 50. When components (2) sugar or sugar alcohol and component (3) are used in combination, a suitable mass ratio is (2):(3), which is 1:0.01 to 5. When a starch-degrading enzyme and a lipolytic enzyme are used in combination as enzymes, a suitable mass ratio of the former to the latter is 1:0.01 to 10.

[0048] In the present invention, it is not necessary to use emulsifiers, oils, etc. during the heat treatment of wheat flour, and if added, the emulsifiers and oils are preferably used in very small amounts of less than 0.05% by mass, more preferably less than 0.01% by mass, and even more preferably less than 0.005% by mass, based on the wheat flour. In the mixture, the total amount of ingredients other than wheat flour, water, and the above-mentioned secondary ingredients is preferably 10% by mass or less, more preferably 5% by mass or less, based on the wheat flour.

[0049] The heat treatment of a mixture of water at a predetermined temperature, wheat flour, and auxiliary ingredients is preferably performed by heating the mixture at an ambient temperature of 100°C or higher but lower than 120°C for 3 to 60 seconds. The "ambient temperature" referred to here refers to the air temperature of the space surrounding the mixture (wheat flour) to be heated, not the temperature of the heated object itself (the temperature of the mixture). An ambient temperature of 100°C or higher and a heating time of 3 seconds or longer has the advantage of ensuring sufficient starch gelatinization. Furthermore, an ambient temperature of less than 120°C and a heating time of 60 seconds or shorter has the advantage of suppressing excessive stickiness due to starch gelatinization and maintaining productivity. From these perspectives, a heating time of 4 to 30 seconds is more preferable. Therefore, the ambient temperature is preferably 100°C or higher but lower than 120°C. In the present invention, the wheat flour, water, and auxiliary ingredients may be mixed and heated simultaneously, or the heating may be performed after mixing. For example, by adding flour, water, and a secondary ingredient to a container whose internal atmosphere has been heated in advance, the flour, secondary ingredient, and water can be mixed together while heating. Whether mixing flour, water, and a secondary ingredient and heating are performed simultaneously or heating is performed after mixing, the heating time starts when the flour is added to the container.

[0050] In the method for producing heat-treated wheat flour of the present invention, it is also preferable to set the temperature of the mixture during the heat treatment to between 90°C and 120°C. A mixture temperature of 90°C or higher has the advantage of ensuring sufficient gelatinization. Furthermore, a temperature of 120°C or lower has the advantage of suppressing excessive protein denaturation and maintaining the processability of bakery foods and the like. From these perspectives, the temperature of the mixture is preferably between 90°C and 120°C, and more preferably between 95°C and 110°C. In the method for producing heat-treated wheat flour of the present invention, the temperature of the mixture only needs to reach between 90°C and 120°C at least once during the heat treatment. For example, the temperature of the mixture can be measured at the completion of the heat treatment. However, as described above, the temperature of the mixture at the completion of the heat treatment may be outside the range of between 90°C and 120°C, as long as the temperature of the mixture reaches between 90°C and 120°C at least once during the heat treatment. To achieve the temperature of the mixture within the above range, the temperature and amount of water added to the wheat flour during the mixing process may be adjusted within the above range, the time from when the wheat flour and water are mixed to when the heat treatment begins may be adjusted, and the atmospheric temperature and heating time during the heat treatment may be adjusted to within the above range. Mixing the wheat flour, water at a predetermined temperature, and auxiliary ingredients and heating the mixture are preferably performed continuously, in order to achieve a temperature within the range described below when the heat treatment is completed. "Continuously" refers to, for example, mixing the wheat flour, water at a predetermined temperature, and auxiliary ingredients and starting heating within a few seconds, including the case where the wheat flour, water, and auxiliary ingredients are each introduced into a container whose internal atmosphere has been preheated. When measuring the temperature of the mixture in the heat treatment device, for example, when using a device that heats the contents of a container while transporting them from an inlet to an outlet using an internal extruder, the temperature of the mixture can be the temperature of the mixture at the outlet.

[0051] The heat treatment according to the present invention can be carried out using any known heating device, but preferably, a device that adds water to gelatinize the starch in the wheat flour and performs the heat treatment can be used. The heat treatment can be carried out using known heating devices such as an autoclave or a steam oven. One example of the heat treatment according to the present invention is a process in which wheat flour, water, and auxiliary ingredients are sealed in a sealed container that can be heated using an aluminum pouch or a heat jacket, and then heated under pressure. The atmosphere inside the sealed container may be preheated to a desired temperature before the introduction of the wheat flour and water. A suitable stirring mechanism may also be provided inside the sealed container. The pressurization may be achieved by heated steam in the sealed container. Another example of the heat treatment according to the present invention is a process in which wheat flour, water, and auxiliary ingredients are introduced into a sealed container, and the mixture is stirred as needed. At the same time, before, or after (preferably before) the introduction of saturated steam, the mixture is heated under pressure (in this case, the amount of saturated steam is not included in the amount of water added to the wheat flour). These processes can be carried out using, for example, a single-screw or twin-screw extruder. The term "under pressure" here refers primarily to a pressurized state created by steam filling the container, and does not refer to a pressurized state created by contacting the raw material wheat with an object such as a pusher (a component equivalent to the screw in an extruder). The steam flow rate is preferably adjusted so that the pressure inside the container is within the range of 10 to 100 kPa gauge pressure.

[0052] Examples of wheat flours used as raw materials for the heat-treated wheat flour of the present invention include strong wheat flour, semi-strong wheat flour, medium-strength wheat flour, weak wheat flour, and durum wheat flour, and these can be used alone or in combination of two or more. Wheat flour milled from domestically grown (Japanese) wheat (hereinafter also referred to as "domestic wheat flour") is particularly preferred as a raw material for the heat-treated wheat flour of the present invention. Examples of currently existing domestic wheat varieties include the following wheat varieties that have been registered in Japan to date: Aoba no Koi, Akitakko, Abukumawase, Ayahikari, Iwainodaichi, Kitakamikomugi, Kitasachiho, Kitanokaori, Kitahonami, Kitamoe, Kinuakari, Kinuazuma, Kinuiroha, Kinu no Nami, Kinuhime, Koyukikomugi, Sato no Sora, Sanuki no Yume 2000, Sanuki no Yume 2009, Shunyou, Shirasagikomugi, Shiranekomugi, Shiroganekomugi, Seto Kirara, Taisetsukomugi, Takunekomugi, Double 8, Tamaizumi, Chikugoizumi, Chikushi W2, Chihokukomugi, Tsurukichi, Tsurupikari, Nanbukomugi, Nishinokaori, Nishihonami, Ne Norigoshi, Nebarigoshi, Hanamante, Haruib, Harukirari, Haruhinode, Haruyutaka, Harebuki, Hareyutaka, Bandowase, Fusetsu, Fukuakari, Fukusayaka, Fukuharuka, Fukuhonoka, Hokushin, Holosirikomugi, Mochihime, Yukichikara, Yukiharuka, Yumeakari, Yumeasahi, Yumekaori, Yumekirari, Yumeshihou, Yumeseiki, Yumechikara, Ginga no Chikara, Koiku 21, Haru no Kagayaki, Haruyokoi, Nagasaki W2, Tokai 103, Tokai 104, Higashiyama 42, Norin 61, Fukui Prefectural University 3, Tone 3, Double 8, Minami no Kaori. The present invention aims to improve texture using heat-treated wheat flour, without being limited by the amylose content in the starch of the wheat flour. However, it is preferable that the wheat flour used as raw material has an amylose content in the starch of 25% or less, as this is because the effect of improving the chewy and moist texture is particularly significant.

[0053] In the method for producing heat-treated wheat flour of the present invention, a mixture containing wheat flour and heated water may be heat-treated as described above, and the resulting heat-treated wheat flour may be pulverized. In the present invention, if pulverization is performed after heat treatment, it is preferable to pulverize the heated mixture without a granulation step. The granulation step refers to a step of granulating the heated mixture into dough particles. Examples of granulation steps include a granulation step using an extrusion granulator, a mixer granulator, or the like. Other examples include a step of stretching the heated mixture between two rolls and then cutting the stretched dough into granules, or a step of cutting the mixture extruded from a kneader into small pieces and granulating the mixture when the kneader is used for the heat treatment. The particle diameter of the dough particles can be 1 mm to 50 mm, preferably 5 mm to 20 mm.

[0054] When the heat-treated wheat flour obtained by the heat treatment is pulverized, the pulverization method is not particularly limited and any known method can be used, for example, roll pulverization, impact pulverization, airflow pulverization, pin mill pulverization, etc., among which pin mill pulverization and airflow pulverization are preferably used.

[0055] When grinding heat-treated wheat flour, the heat-treated wheat flour may be dried prior to grinding. As mentioned above, heat-treated wheat flour is usually in a wet state, so drying before grinding allows for more appropriate grinding. Drying can be carried out by known methods such as shelf drying, hot air drying, and fluidized bed drying. The drying temperature during drying is preferably low-temperature drying at 30°C to 70°C for 6 hours to 24 hours, high-temperature drying at 100°C to 180°C for 5 seconds to 120 seconds, low-temperature drying more preferably 40°C to 60°C, and high-temperature drying more preferably 120°C to 160°C. Drying may also be carried out simultaneously with grinding.

[0056] Next, preferred forms of the heat-treated wheat flour of the present invention will be described. Preferred examples of the heat-treated wheat flour of the present invention include the following four forms (i), (ii), (iii), and (iv).

[0057] (i) The amount of eluted sugars (mg) per 1 g of heat-treated wheat flour is 66 mg to 76 mg, and the gluten vitality is 22 to 50, where the gluten vitality when untreated is 100. In the following examples, the gluten vitality when the gluten vitality when untreated is 100 may be referred to as "GV." (ii) The amount of eluted sugars (mg) per 1 g of heat-treated wheat flour is 79 mg to 193 mg, and when the eluted equivalent (mg) is (A), and the amount of eluted sugars (mg) per 1 g of heat-treated wheat flour after heat-treating the wheat flour and adding the secondary ingredients is (B), (A) / (B) x 100(%) is 63% to 83%. (iii) The amount of sugar (mg) extracted per 1 g of heat-treated wheat flour is 77 mg or more and 145 mg or less, and when the amount of sugar (mg) extracted is (A) and the amount of reducing ends (mg) as glucose per 1 g of heat-treated wheat flour is (C), the ratio (A) / (C) is 5 or more and 18 or less. (iv) The amount of sugar (mg) extracted per 1 g of heat-treated wheat flour is 58 mg or more and 69 mg or less, and the degree of complex formation by iodine colorimetry is 27% or more and 81% or less.

[0058] The first embodiment of the present invention is defined as a case where the above condition (i) is satisfied. The heat-treated wheat flour of the first embodiment has an eluted sugar amount (mg) of 66 to 76 mg per gram of heat-treated wheat flour, and a gluten vitality of 22 to 50, where the gluten vitality of the untreated wheat flour is 100. A higher eluted sugar amount compared to conventional heat treatment without the addition of secondary ingredients indicates a high degree of starch swelling and a high amount of sugar chain degradation products in the production of breads and cakes. A high eluted sugar amount leads to suppression of texture deterioration during frozen storage. Furthermore, low gluten vitality indicates protein denaturation, and a low eluted sugar amount leads to brittle texture and reduced processability. On the other hand, in this embodiment, since the eluted sugar amount is within a specified range, even if the gluten vitality is lower than that of Patent Document 1, such disadvantages do not occur. Rather, the lower gluten vitality compared to Patent Document 1 simultaneously promotes starch swelling and degradation, which is thought to have the advantage of improving freeze resistance. In particular, from the viewpoint of improving texture, the amount of eluted sugar (mg) is more preferably 66 mg or more and 76 mg or less, and the gluten vitality is more preferably 40 or more and 50 or less, where the gluten vitality in the untreated state is set to 100. Methods for measuring the amount of eluted sugar (mg) and gluten vitality will be described later.

[0059] The heat-treated wheat flour of the first embodiment preferably has (v) a pH of 5 or more and 6 or less. (v) Having a pH of 5 or more and 6 or less, i.e., a slightly acidic to neutral pH, the heat-treated wheat flour of this embodiment is particularly excellent in improving texture. In this specification, the pH of the heat-treated wheat flour refers to the pH of a suspension at 25°C in which 1 g of heat-treated wheat flour is suspended in 10 mL of purified water.

[0060] The heat-treated wheat flour of the first embodiment can be obtained by adjusting the heat treatment conditions and the conditions for adding the auxiliary ingredients in the above-mentioned method for producing heat-treated wheat flour using (1) a pH-adjusting material. The heat-treated wheat flour of this embodiment preferably contains a pH-adjusting material. In this specification, the term "per 1 g" used in reference to heat-treated wheat flour containing an auxiliary ingredient refers to the amount per 1 g of wheat flour containing the auxiliary ingredient.

[0061] The second embodiment of the present invention satisfies the above condition (ii). The heat-treated wheat flour of the second embodiment has an eluted sugar amount (mg) per gram of wheat flour of 79 mg to 193 mg, and the eluted equivalent (mg) is (A). The eluted sugar amount (mg) per gram of heat-treated wheat flour obtained by heat-treating wheat flour and then adding a secondary ingredient is (B). (A) / (B) x 100 (%) is 63% to 83%. In this embodiment, the eluted sugar amount (mg) per gram of heat-treated wheat flour (A) is large, at 79 mg to 193 mg, but the eluted sugar amount (mg) (A) is significantly smaller than the eluted sugar amount (mg) (B) obtained when heat-treating wheat flour without adding a secondary ingredient and then mixing the secondary ingredient after heat-treatment. This type of structure is believed to be excellent in improving texture when bakery foods are prepared, because the starch and auxiliary ingredients in the wheat flour are compounded by heat treatment, forming steric hindrance within the starch sugar chains or exhibiting water retention within the sugar chains. In fact, the present inventors have found that this structure has a particularly good texture-improving effect. For example, the amount of sugar extracted from (B) is exemplified as 98 to 259 mg. The value of (A) / (B) x 100(%) is preferably 63% or more and 82.1% or less.

[0062] Here, when measuring the amount of extracted sugars (mg) per gram of heat-treated flour after heat-treating and adding auxiliary ingredients (B), the manufacturing method of the heat-treated flour to which the auxiliary ingredients are added later is preferably the same as that of the heat-treated flour for which (A) / (B) is measured, except that the auxiliary ingredients are not added during the heat treatment. Alternatively, as a convenient standard, the manufacturing method of the heat-treated flour of the present invention, such as the manufacturing method of heat-treated flour in Comparative Example 5 herein, can be adopted. The wheat brand and variety of the raw wheat flour should be the same as that of the heat-treated flour for which (A) / (B) is measured. When measuring the amount of extracted sugars (B), the heat-treated flour and auxiliary ingredients can be mixed, for example, by placing 100 g of flour in a container such as a bowl, adding the auxiliary ingredients, and stirring for 10 minutes at approximately 60 rpm using a Hobart mixer or bread mixer. The heat-treated flour of the second type can be obtained by using (2) sugar or sugar alcohol in the manufacturing method of heat-treated flour described above, and adjusting the heat treatment conditions and auxiliary ingredient addition conditions, etc. The heat-treated wheat flour of this embodiment preferably contains sugar or sugar alcohol.

[0063] The case where the above condition (iii) is satisfied is also referred to as the third embodiment of the present invention. In this embodiment, the amount of eluted sugar (mg) per gram of heat-treated wheat flour is 77 mg to 145 mg, and the ratio (A) / (C) is 5 to 18, where (A) is the amount of eluted sugar (mg) and (C) is the amount of reducing ends (mg) of glucose per gram of heat-treated wheat flour. As described above, a high amount of eluted sugar (mg) indicates the progress of starch gelatinization and swelling due to heat treatment and the progress of enzymatic degradation of starch sugar chains during heat treatment. This contributes to the texture effect when bakery foods are prepared through starch gelatinization, swelling, and enzymatic degradation. Furthermore, the ratio (A) / (C) of the amount of reducing ends (mg) to the amount of eluted sugar (mg) represents the average glycan length of the eluted sugar, which is the average glycan length obtained by dividing the amount of sugar constituting the glycan dissolved from the flour sample in deionized water by the number of glycan ends. In this embodiment, by having this average sugar chain length within a predetermined range, sugar chains of this chain length interact with the starch in the wheat flour, suppressing starch recrystallization and syneresis, thereby providing retrogradation resistance and freezing resistance, which can contribute to texture effects when bakery foods are prepared. In this embodiment, it is thought that the excellent balance of these factors results in an excellent texture improvement effect.

[0064] In view of the excellent texture improving effect in this embodiment, the amount of eluted sugar (mg) (A) is preferably 77 mg to 145 mg, more preferably 103 mg to 145 mg. Furthermore, (A) / (C) is preferably 5 to 18, more preferably 5 to 8. Furthermore, the amount of reducing end (mg) (C) is preferably 5 mg to 26 mg, more preferably 10 mg to 26 mg.

[0065] The heat-treated wheat flour of the third embodiment can be obtained by using a starch-degrading enzyme as the enzyme (3) in the method for producing heat-treated wheat flour described above, and adjusting the heat treatment conditions, the conditions for adding the auxiliary material, etc. The heat-treated wheat flour of this embodiment preferably contains a starch-degrading enzyme.

[0066] The case where the above (iv) is satisfied is also referred to as the fourth embodiment of the present invention. In this embodiment, (iv) the amount of soluble sugar (mg) per gram of heat-treated wheat flour is 58 mg to 69 mg, and the degree of complex formation by iodine colorimetry is 27% to 81%. This configuration indicates that the heat-treated wheat flour of this embodiment contributes to a moist and chewy texture with a certain amount of soluble sugar, while forming a lipid-starch complex, thereby suppressing the recrystallization of starch sugar chains and syneresis, and this effect also enhances the moist and chewy texture. The lipid here is preferably derived from wheat flour. From the viewpoint of obtaining a more excellent texture improvement effect, in this embodiment, the amount of soluble sugar (mg) per gram of heat-treated wheat flour is preferably 58 mg to 69 mg. Furthermore, the degree of complex formation by iodine colorimetry is more preferably 58% to 81%. The heat-treated wheat flour of the fourth embodiment can be obtained by using a lipolytic enzyme as the enzyme (3) in the method for producing heat-treated wheat flour described above, and adjusting the heat treatment conditions, the conditions for adding the secondary ingredients, etc. The heat-treated wheat flour of this embodiment preferably contains a lipolytic enzyme.

[0067] The methods for measuring the amount of eluted sugar (mg), gluten vitality, the amount of reducing ends (mg), and the degree of complex formation by iodine colorimetry will be described below.

[0068] <Amount of eluted sugar (mg / 1 g of flour sample)> The amount of eluted sugar refers to the amount of sugar constituting the glycan dissolved from the flour sample into deionized water. The measurement method is the phenol-sulfuric acid method, as follows. 1 g of flour sample is combined with 20 ml of deionized water at room temperature and shaken at 125 rpm for 30 minutes, and then centrifuged at 4700 rpm for 10 minutes to recover the supernatant. 0.5 ml of the supernatant appropriately diluted with deionized water is mixed with 0.5 ml of a 5% by weight aqueous phenol solution, and 3 ml of sulfuric acid is added dropwise. The mixture is then left to stand at room temperature for 30 minutes. The absorbance of the solution is then measured using a spectrophotometer (490 nm). The amount of eluted sugar is calculated based on a calibration curve drawn using an aqueous glucose solution. The dilution is preferably performed so that the absorbance is in the range of 0.1 to 2.0.

[0069] <Reducing end amount (mg / 1 g of flour sample)> The reducing end amount (mg) refers to the amount of reducing sugars present at the ends of the glycans dissolved from the flour sample in deionized water. The measurement method is the Somogyi-Nelson method, as follows. 1 g of flour sample is shaken with 20 ml of deionized water at room temperature for 30 minutes at 125 rpm, and then centrifuged at 4700 rpm for 10 minutes to recover the supernatant. 0.5 ml of the supernatant appropriately diluted with deionized water is mixed with 0.5 ml of Somogyi copper solution, sealed, heated in an oil bath at 100°C for exactly 10 minutes, cooled on ice, and 1.0 ml of Nelson's reagent is added, stirred, and allowed to stand for 30 minutes. The solution is diluted with deionized water, and the absorbance is measured using a spectrophotometer (520 nm). The reducing sugar amount is calculated based on a calibration curve plotted using an aqueous glucose solution. The dilution is preferably performed so that the absorbance is in the range of 0.1 to 2.0.

[0070] <Complex Formation Degree (%)> The complex formation degree can be calculated by the following formula, where α is the absorbance of flour that has not formed a complex with lipid, and β is the absorbance of flour that has formed a complex with lipid: Complex formation degree (%) = (α - β) / α × 100

[0071] The method for measuring the degree of complex formation (%) is called the iodine colorimetric method and is as follows. 1 g of flour sample is shaken with 20 ml of deionized water at room temperature at 125 rpm for 30 minutes, and then centrifuged at 4700 rpm for 10 minutes to recover the supernatant. 40 μl of iodine solution is added to 1.0 ml of the appropriately diluted supernatant, and after stirring, the absorbance (690 nm) is measured. The measured value is introduced into the defined formula to calculate the degree of complex formation. Note that the above dilution is preferably performed so that the absorbance is in the range of 0.1 to 2.0. Here, "flour that has formed a complex with lipids" refers to heat-treated wheat flour, and "flour that has not formed a complex with lipids" refers to untreated flour. Untreated flour is unheat-treated wheat flour of the same variety and brand as the heat-treated flour.

[0072] <Measurement of gluten vitality> (1) Measurement of soluble crude protein content of wheat flour: (a) Accurately weigh out 2 g of sample (heat-treated wheat flour / untreated wheat flour) into a 100 mL beaker. (b) Add 40 mL of 0.05 N acetic acid to the beaker and stir at room temperature for 60 minutes to prepare a suspension. (c) Transfer the suspension obtained in (b) to a centrifuge tube and centrifuge at 5000 rpm for 5 minutes, then filter using filter paper to recover the filtrate. (d) Wash the beaker used above with 40 mL of 0.05 N acetic acid, transfer the washings to a centrifuge tube, centrifuge at 5000 rpm for 5 minutes, then filter using filter paper to recover the filtrate. (e) Combine the filtrates recovered in (c) and (d) and measure up to 100 mL. (f) 25 mL of the liquid obtained in (e) was placed in a Kjeldahl tube of a Kjeltek Autosystem (Ticator, Sweden) using a volumetric pipette, and one tablet of decomposition accelerator ("Keltab C" manufactured by Nippon General Co., Ltd.; potassium sulfate: copper sulfate = 9:1 (mass ratio)) and 15 mL of concentrated sulfuric acid were added. (g) Using a Kjeltek decomposition furnace (DIGESTION SYSTEM 20 1015 type) incorporated in the Kjeltek Autosystem, decomposition treatment was carried out for 1 hour at dial 4, and then automatically decomposition treatment was carried out for 1 hour at dial 9 or 10. After this decomposition treatment, the Kjeltek distillation titration system (KJELTEC AUTO 1030 type) incorporated in the same Kjeltek Autosystem was used to continuously and automatically distill and titrate the decomposed liquid (using 0.1 N sulfuric acid for titration), and the soluble crude protein content of the sample (heat-treated wheat flour / untreated wheat flour) was calculated using the following formula: (Equation 1) Soluble crude protein content (%) = 0.14 x (T - B) x F x N x (100 / S) x (1 / 25) In the formula, T = amount of 0.1 N sulfuric acid required for titration (mL) B = amount of 0.1 N sulfuric acid required for titration of blank (mL) F = titer of 0.1 N sulfuric acid used for titration (measure immediately before use or use a commercially available product with a titer indicated) N = nitrogen protein conversion factor (5.70) S = weighed amount of sample (g)

[0073] (2) Measurement of total crude protein content of wheat flour: (a) 0.5 g of sample (heat-treated wheat flour / untreated wheat flour) is weighed and placed in the Kjeldahl tube of the Keltec Auto System of the same company as used in (1) above, and one tablet of the same decomposition accelerator and 5 mL of concentrated sulfuric acid are added thereto. (b) Using the Keltec decomposition furnace of the same Keltec Auto System as used in (1) above, decomposition treatment is carried out for 1 hour at dial 9 or 10, and then, following this decomposition treatment, the liquid subjected to the decomposition treatment is continuously and automatically distilled and titrated (using 0.1 N sulfuric acid for titration) using the same Keltec distillation titration system as used in (1) above, which is incorporated into the same Keltec Auto System, and the total crude protein content of the sample (heat-treated wheat flour / untreated wheat flour) is calculated using the following formula. (Equation 2) Total crude protein content (%) = (0.14 x T x F x N) / S In the formula, T = amount of 0.1 N sulfuric acid required for titration (mL) F = titer of 0.1 N sulfuric acid used for titration (measured before use) N = nitrogen protein conversion factor (5.70) S = weight of sample (g)

[0074] (3) Calculation of gluten vitality: The gluten vitality of the sample is calculated from the soluble crude protein content of the sample calculated in (1) above and the total crude protein content of the sample calculated in (2) above using the following formula: (Equation 3) Gluten vitality (%) = (soluble crude protein content / total crude protein content) × 100 The gluten vitality value thus obtained for untreated flour is set to 100, and the relative value is taken as the gluten vitality of the heat-treated wheat flour.

[0075] The present invention also encompasses heat-treated flour obtained by the heat-treated flour manufacturing method of the present invention. The inventors have discovered that the use of heat-treated flour obtained by the heat-treated flour manufacturing method of the present invention effectively improves the moist and chewy texture of bread and effectively suppresses the deterioration of bakery foods, such as pancakes, which tend to become brittle over time when frozen. However, the heat-treated flour obtained by the heat-treated flour manufacturing method of the present invention has a variety of physical properties and characteristics. Therefore, clarifying all of these properties and characteristics in an application would require long-term research, as it would require the development of methods to identify the physical properties, and is practically impossible in the field of food, which has a short product shelf life. Therefore, in this application, the heat-treated flour obtained by the heat-treated flour manufacturing method of the present invention is also defined in the claims as a constituent of the heat-treated flour. As described above, at the time of filing, circumstances existed in which it was impossible or practical to directly identify the product by its structure or properties other than those described in this specification.

[0076] The heat-treated wheat flour of the present invention can be used in various food applications after secondary processing, with bakery foods being a typical example. Bakery foods, as used herein, refer to foods obtained by subjecting fermented or unfermented dough, primarily made from cereal flour, to which, as needed, secondary ingredients such as yeast, leavening agents, water, salt, and sugar are added, to heat treatments such as baking, steaming, and frying. Examples of bakery foods to which the present invention can be applied include breads and confectioneries. Examples of breads include white bread, French bread, rolls, buns, croissants, and pizza. Examples of confectioneries include donuts, dorayaki, sponge cakes, butter cakes, hotcakes, pancakes, muffins, and cookies. Examples of bakery foods that tend to become brittle when frozen include breads such as white bread, French bread, rolls, buns, and pizza, and confectioneries such as hotcakes, dorayaki, sponge cakes, butter cakes, hotcakes, pancakes, and muffins.

[0077] The heat-treated wheat flour of the present invention can also be used as a bakery food mix, and in addition to the heat-treated wheat flour obtained by the heat-treated wheat flour manufacturing method of the present invention or the heat-treated wheat flour of the present invention, non-heat-treated wheat flour may be contained. As the non-heat-treated wheat flour, untreated wheat flour that has not been heat-treated can be used, for example, hard wheat flour, semi-hard wheat flour, medium-strength wheat flour, soft wheat flour, durum wheat flour, etc., and one of these can be used alone or two or more can be used in combination. When the bakery food mix contains non-heat-treated wheat flour, the amount of heat-treated wheat flour is preferably 1 to 40 parts by mass per 100 parts by mass of the total of the heat-treated wheat flour and non-heat-treated wheat flour.

[0078] The present invention has been described above based on its preferred embodiments, but the preferred configurations described in the above or below examples can be combined with any other preferred configurations described above or below. Note that the preferred configurations referred to here are not limited to more preferred, particularly preferred, etc., and can be combined with any other configurations at any stage.

[0079] The present invention will be described below using examples, but the present invention is not limited to these examples. In the examples below in which an enzyme was used as a secondary ingredient, the enzyme was mixed with wheat flour and then mixed with a predetermined amount of water at a predetermined temperature. In the examples and comparative examples in which heat treatment was performed below, saturated steam was introduced into a container during heat treatment to heat the mixture under pressure. The temperature of the steam circulating in the container was 98 to 110°C, and the pressure inside the container was within the above-mentioned range.

[0080] Comparative Examples 1 and 2 Ground wheat products of the brands shown in Table 1 were used as wheat flour in the comparative examples.

[0081] (Comparative Examples 3 to 5, Examples 1 to 7) (Preparation of Heat-Treated Wheat Flour) A sealed container equipped with a heat jacket and a single-screw extruder was heated to an ambient temperature of 103°C in advance. Specifically, the sealed container was heated from the outside using a heat jacket using steam as a heat source, and the ambient temperature inside the container was heated to 103°C. Wheat flour was then prepared by milling the varieties and brands of wheat listed in Table 1. Water heated to 80°C was prepared in the amount listed in Table 1 relative to the wheat flour. In Comparative Examples 3 to 5, no auxiliary ingredients were added to the wheat flour. The wheat flour and the heated water were mixed, heated for 5 seconds in the sealed container set at the predetermined ambient temperature, and then discharged from the sealed container. In Examples 1 to 7, the wheat flour and the heated water were mixed with the pH-adjusting ingredients listed in Table 1 in the amounts listed in Table 1 to obtain a mixture of wheat flour, the heated water, and the pH-adjusting ingredients. The mixture was then heated for 5 seconds in a sealed container set at an ambient temperature of 103°C and discharged from the sealed container. The temperature of the mixture at the completion of heating (the temperature of the mixture at the outlet of the sealed container) was the temperature shown in Table 1. During the heat treatment, saturated steam was introduced into the container to heat the mixture. The flow rate of steam in the container was adjusted to achieve the temperature shown in Table 1. The heat-treated mixture was dried in a thermostatic chamber at 50°C for 12-24 hours and then ground using a pin mill (Hosokawa Micron Corporation, Colloplex 160Z). The heat-treated wheat flour was passed through a 200 μm sieve, and the undersieve was collected as the heat-treated wheat flour. The kansui (water sachet) used in Table 1 was "Powdered Kansui Red" manufactured by Oriental Yeast Co., Ltd. The umeboshi (pickled plum) powder (citric acid content: 3.4% by mass) manufactured by Natural Kitchen Co., Ltd. The acerola powder used was "Acerola Powder VC20" manufactured by Nichirei Corporation (citric acid content: 1.1% by mass). As the lemon powder, "Lemon Powder NV-31" (citric acid content 6.5% by mass) manufactured by Nikken Foods Co., Ltd. was used.

[0082] As Reference Example 1, a mixture was prepared by mixing the heat-treated wheat flour of Comparative Example 5 with citric acid in an amount of 0.025 parts by mass per 100 parts by mass of wheat flour in the same manner as in Example 4.

[0083] [Evaluation and Measurement] The amount of soluble sugar, GV (gluten vitality when the gluten vitality in the untreated sample is taken as 100, and is shown as "(%)" in each table) and pH were measured by the above-mentioned methods for the non-heat-treated wheat flours of Comparative Examples 1 and 2 and the heat-treated wheat flours of Comparative Examples 3 to 5 and Examples 1 to 7. The amount of soluble sugar and GV were measured by the above-mentioned methods for the heat-treated wheat flour of Reference Example 1. The results are shown in Table 1.

[0084] (Evaluation Test Example 1) Using the non-heat-treated wheat flour of Comparative Examples 1 and 2, the heat-treated wheat flour of Comparative Examples 3 to 5 and Examples 1 to 7, and the separately heat-treated wheat flour of Reference Example 1 as the evaluation subjects, pancakes, a type of bakery food, were produced by the following method. 40 g of non-heat-treated wheat flour (brand: Flour manufactured by Nisshin Flour Milling Co., Ltd.) was mixed in a bowl as powder ingredients, 10 g of the wheat flour to be evaluated, 12.5 g of white sugar, and 2.5 g of baking powder. Then, 5 g of salad oil, 15 g of whole egg liquid, 40 g of milk, and 30 g of water were added to the bowl as liquid ingredients. The mixture was hand-mixed using a whisk at 120 rpm for 1 minute and then baked at 180°C for 3 minutes on the front side and 2 minutes on the back side. The baked product was allowed to cool at 27°C for 30 minutes, packaged, and stored at -5°C for 30 days and used for texture evaluation. The frozen pancakes were thawed at 27°C for 2 hours. Next, the texture of the pancakes was evaluated by 10 expert panelists based on the following evaluation criteria. The average evaluation scores of the 10 panelists are shown in Table 1.

[0085] (Evaluation criteria for pancake texture: moist) 5 points: Very moist, very good texture. 4 points: Moist, good texture. 3 points: Slightly moist, somewhat good texture. 2 points: Slightly dry, somewhat unfavorable texture. 1 point: Very dry, very unfavorable texture.

[0086] (Evaluation criteria for pancake texture: chewy) 5 points: Very chewy, very good texture. 4 points: Chewy, good texture. 3 points: Slightly chewy, somewhat good texture. 2 points: Slightly brittle, somewhat unfavorable texture. 1 point: Very brittle, very unfavorable texture.

[0087]

[0088] As shown in Table 1, heat-treated wheat flour, which is prepared by mixing a pH-adjusting material with a predetermined amount of water and wheat flour at a predetermined temperature and then heating the mixture, provides bakery foods with superior freeze resistance compared to wheat flour without the pH-adjusting material. Heat-treated wheat flour with a predetermined amount of eluted sugar and a predetermined gluten vitality also provides bakery foods with superior freeze resistance compared to the heat-treated wheat flours of Comparative Examples 1 to 5, which do not satisfy the aforementioned criteria.

[0089] (Examples 8 to 15) (Preparation of heat-treated wheat flour) Heat-treated wheat flour was obtained in the same manner as in Example 1, except that the pH-adjusting material listed in Table 1 was replaced with the sugar or sugar alcohol listed in Table 2 in the amount listed in Table 2.

[0090] [Evaluation and Measurement] The amount of soluble sugar (A) was measured for the heat-treated wheat flour of Examples 8 to 15. The heat-treated wheat flour of Comparative Example 5 was mixed with the same amount of sugar or sugar alcohol as used in that Example under the post-addition conditions described above, and the amount of soluble sugar (B) was measured using the method described above to determine the value of (A) / (B) x 100 (%). The results are shown in Table 2. The heat-treated wheat flour of Examples 8 to 15 was also evaluated (Evaluation Test Example 1). The results are shown in Table 2. Furthermore, when determining (B) above, the heat-treated wheat flour obtained by post-adding the same amount of sugar alcohol as in Example 13 to the heat-treated wheat flour of Comparative Example 5 was also evaluated (Evaluation Test Example 1). The results are also shown in Table 2 as Reference Example 2. Table 2 also shows the treatment details and evaluation results for Comparative Examples 1 to 5.

[0091]

[0092] As shown in Table 2, heat-treated wheat flour, which is prepared by mixing wheat flour with sugar or sugar alcohol and water at a predetermined temperature and in a predetermined amount, and then heating the mixture, yields bakery foods with superior freeze resistance compared to those without added sugar or sugar alcohol. Heat-treated wheat flour with a predetermined amount of eluted sugar and a predetermined (A) / (B) ratio also yields bakery foods with superior freeze resistance compared to the heat-treated wheat flours of Comparative Examples 1 to 5, which do not satisfy the aforementioned criteria. Furthermore, a comparison between Reference Example 2 and Example 13 reveals that adding a secondary ingredient to wheat flour during heat treatment improves the freeze resistance of bakery foods compared to adding the secondary ingredient after heat treatment.

[0093] (Examples 16 to 22) (Preparation of Heat-Treated Wheat Flour) Heat-treated wheat flour was obtained in the same manner as in Example 1, except that the pH-adjusting material listed in Table 1 was replaced with the amylolytic enzyme listed in Table 3 (including starch-containing enzyme-containing material) in the amount listed in Table 3. The enzymes listed in Table 3 used were as follows: Amyloglucosidase: Novozymes' trade name "GoldCrust 3300BG", titer 3300 U / g β-amylase: Amano Enzyme's trade name "β-amylase F "Amano"", titer 650 U / g, optimum temperature 55 ° C. G4 amylase: Nagase ChemteX's trade name "Denabake (registered trademark) EXTRA", titer 6500 U / g, optimum temperature 50 ° C. Malt powder: Oriental Yeast Co., Ltd.'s trade name "Malt Powder" α-amylase: Amano Enzyme's trade name "Biozyme A", titer 7000 U / g, optimum temperature 50 ° C.

[0094] As Reference Example 3, a mixture was prepared by mixing the heat-treated wheat flour of Comparative Example 5 with 0.1 part by mass of α-amylase per 100 parts by mass of wheat flour in the same manner as in Example 20.

[0095] [Evaluation and Measurement] The amount of soluble sugar (A) was measured for the heat-treated wheat flours of Examples 16 to 22. The amount of reducing ends (mg) as glucose per 1 g of heat-treated wheat flour (C) was also determined, and the average sugar chain length ((A) / (C) x 100(%)) was calculated. The results are shown in Table 3. The heat-treated wheat flours of Examples 16 to 22 and the attached heat-treated wheat flour of Reference Example 3 were also evaluated in the same manner as in Evaluation Test Example 1. The results are shown in Table 3. Table 3 also shows the treatment details and evaluation results of Comparative Examples 1 to 5.

[0096]

[0097] As shown in Table 3, heat-treated wheat flour, which is prepared by mixing wheat flour with a predetermined amount of water and a starch-degrading enzyme at a predetermined temperature and heating the mixture, provides bakery foods with superior freeze resistance compared to wheat flour without the addition of a starch-degrading enzyme. Furthermore, heat-treated wheat flour having a predetermined amount of eluted sugar and a predetermined (A) / (C) ratio also provides bakery foods with superior freeze resistance compared to the heat-treated wheat flours of Comparative Examples 1 to 5, which do not satisfy the aforementioned composition.

[0098] (Examples 23 to 27) (Preparation of Heat-Treated Wheat Flour) Heat-treated wheat flour was obtained in the same manner as in Example 1, except that the lipolytic enzymes listed in Table 4 were used in the amounts listed in Table 4 instead of the pH-adjusting ingredients listed in Table 1. PLA2 Nagase 10P / R manufactured by Nagase ChemteX Corporation was used as the phospholipase. Lipase 1 was Lipase AY "Amano" 30SD manufactured by Amano Enzyme Inc. (potency 2500 U / g, optimum temperature 40°C). Lipase 2 was Lipase A5 manufactured by Nagase ChemteX Corporation (potency 100,000-120,000 U / g, optimum temperature 50°C).

[0099] As Reference Example 4, the heat-treated wheat flour of Comparative Example 5 was mixed in the same amount as in Example 25 with 100 parts by mass of wheat flour to prepare a mixture.

[0100] [Evaluation and Measurement] The amount of soluble sugar (A) was measured for the heat-treated wheat flours of Examples 23 to 27. The degree of complex formation was calculated by iodine colorimetry using the method described above. The results are shown in Table 4. The heat-treated wheat flours of Examples 23 to 27 were also evaluated in the same manner as in Evaluation Test Example 1. The results are shown in Table 4. Table 4 also shows the treatment details and evaluation results of Comparative Examples 1 to 5.

[0101]

[0102] (Examples 28 and 29) (Preparation of heat-treated wheat flour) Heat-treated wheat flour was obtained in the same manner as in Example 1, except that the pH-adjusting material listed in Table 1 was replaced with the pH-adjusting material, sugar or sugar alcohol, starch-degrading enzyme, and lipolytic enzyme listed in Table 5 in the amounts listed in Table 5, respectively.

[0103] [Evaluation] The heat-treated wheat flours of Examples 28 and 29 were evaluated in the same manner as in Evaluation Test Example 1. The results are shown in Table 5.

[0104]

[0105] As shown in Table 5, the use of a pH adjusting material, sugar or sugar alcohol, and enzymes significantly improves the freeze resistance of bakery foods.

[0106] (Bread Evaluation) Using the wheat flours of Comparative Examples 1 and 2 and the heat-treated wheat flours obtained in Comparative Example 4 and Examples 4, 13, 20, 25, and 28 as the evaluation subjects, bread, a type of bakery food, was produced by the following method. 320 g of wheat flour milled from Million wheat, 80 g of the evaluation subject wheat flour, 8 g of salt, 32 g of sugar, 9.2 g of fresh yeast ("Oriental Yeast" manufactured by Oriental Yeast Co., Ltd.), 0.4 g of yeast food ("C Yeast Food" manufactured by Oriental Yeast Co., Ltd.), and an appropriate amount of water were placed in the mixing bowl of a commercially available bread mixer (Dalton Co., Ltd., universal mixer model 5DM-03-r), and a mixing process was carried out to prepare bread dough. Specifically, the dough was mixed at low speed for 4 minutes, then at high speed for 2 minutes, and then 16 g of oil was added and mixed at low speed for 4 minutes, followed by kneading at high speed for 1 minute (kneading temperature: 27°C). The resulting dough was fermented for 1 hour at 27°C and 75% relative humidity, then divided into 450 g portions and rolled into balls. After 30 minutes of bench time, the dough was rolled into a loaf of bread and packed into a loaf of bread. The resulting bread was then proofed for 60 minutes (at 38°C and 85% relative humidity) and baked for 30 minutes at 200°C to obtain bread. The resulting bread was left to stand at 4°C for 1 day, and the texture of the resulting bread was evaluated by 10 expert panelists based on the following evaluation criteria. The average evaluation scores of the 10 panelists are shown in Table 6.

[0107] (Evaluation criteria for bread texture: moist) 5 points: The whole bread has a sufficiently moist texture, and the taste and texture are good. 4 points: Although it may lack moistness or softness in some areas, the whole bread has a moist texture, and there are no problems with the taste and texture. 3 points: The bread is slightly moist. 2 points: The whole bread is not very moist, and is dry in some areas. 1 point: The whole bread has a dry texture, and the taste and texture are poor.

[0108] (Evaluation criteria for bread texture: chewy) 5 points: The whole bread has a sufficiently chewy texture, and the taste and texture are good. 4 points: Although it may lack chewy or softness in some areas, the whole bread has a chewy texture, and there are no problems with the taste and texture. 3 points: A slight chewy texture is felt. 2 points: The whole bread has little chewy texture. 1 point: The whole bread is too soft, and the texture is inferior in chewiness, and the taste and texture are poor.

[0109]

[0110] As shown in Table 6, the heat-treated wheat flour of each example also exhibits a good texture improving effect on bread.

[0111] To provide a method for producing heat-treated wheat flour, which can produce bakery foods having a moist and chewy texture and which can maintain the moist and chewy texture even when relatively fragile bakery foods such as hotcakes are frozen and stored for a long period of time, and to provide heat-treated wheat flour.

Claims

1. 100 parts by mass of wheat flour, and at least one auxiliary material selected from the following (1), (2), and (3), and more than 30 parts by mass and 40 parts by mass or less of water at 70°C or higher and 100°C or lower are combined to obtain a mixture, and the mixture is heated. A method for producing heat-treated wheat flour. (1) pH adjusting material (2) Sugar and / or sugar alcohol (3) Enzyme

2. The method for producing heat-treated wheat flour according to claim 1, wherein the auxiliary material uses the (1) pH adjusting material.

3. The method for producing heat-treated wheat flour according to claim 1, wherein the auxiliary material uses the (2) sugar and / or sugar alcohol.

4. The method for producing heat-treated wheat flour according to claim 1, wherein the auxiliary material uses the (3) enzyme.

5. The method for producing heat-treated wheat flour according to claim 1, wherein the auxiliary material uses the (1) pH adjusting material, the (2) sugar and / or sugar alcohol, and the (3) enzyme.

6. The method for producing heat-treated wheat flour according to claim 4, wherein the (3) enzyme is at least one selected from amylase and lipase.

7. The method for producing heat-treated wheat flour according to any one of claims 1 to 6, wherein the mixture is heated at an ambient temperature of 100°C or higher and less than 120°C for 3 seconds or more and 60 seconds or less.

8. The amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 66 mg or more and 76 mg or less, and the gluten vitality is 22 or more and 50 or less when the gluten vitality before treatment is set to 100. Heat-treated wheat flour.

9. The heat-treated wheat flour according to claim 8, having a pH of 5 or more and 6 or less.

10. The amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 79 mg or more and 193 mg or less. Taking the amount of eluted sugar (mg) as (A), After heat-treating wheat flour, when taking the amount of eluted sugar (mg) per 1 g of the heat-treated wheat flour after adding auxiliary materials as (B), The heat-treated wheat flour for which (A) / (B)×100(%) is 63% or more and 83% or less.

11. The amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 77 mg or more and 145 mg or less. Taking the amount of eluted sugar (mg) as (A), When taking the amount of reducing end as glucose (mg) per 1 g of heat-treated wheat flour as (C), The heat-treated wheat flour for which (A) / (C) is 5 or more and 18 or less.

12. The amount of eluted sugar (mg) per 1 g of heat-treated wheat flour is 58 mg or more and 69 mg or less, The heat-treated wheat flour for which the degree of complex formation by iodine colorimetry is 27% or more and 81% or less.

13. 100 parts by mass of wheat flour, At least one auxiliary material selected from the following (1), (2), and (3), More than 30 parts by mass and 40 parts by mass or less of water at 70°C or more and 100°C or less are combined to obtain a mixture, and the heat-treated wheat flour obtained by heating the mixture. (1) pH adjustment material (2) Sugar and / or sugar alcohol (3) Enzyme