Manufacturing method of dry-heat-treated whole wheat flour

Abstract

To provide a method for producing dry-heat treated whole-wheat flour capable of obtaining wheat processed foods such as noodles reduced in bran odor and excellent in elasticity.SOLUTION: The method for producing dry-heat treated whole-wheat flour includes a step of milling wheat grains to obtain whole-wheat flour and a step of subjecting the whole-wheat flour to dry-heat treatment at 90 to 130°C for 1 to 20 minutes to obtain dry-heat treated whole-wheat flour. The dry-heat treated whole-wheat flour is used to obtain wheat processed foods such as noodles reduced in bran odor and excellent in elasticity.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing dry-heat treated whole wheat flour. [Background technology]

[0002] Noodles are produced by kneading wheat flour-based ingredients with water to obtain noodle dough, which is then processed into noodle strands. Noodles produced in this manner are characterized by a smooth surface and moderate elasticity. In recent years, with growing health consciousness, there has been an increasing demand for noodles made using whole wheat flour containing wheat bran and germ, which are rich in nutrients such as dietary fiber, vitamins, and minerals. Whole wheat flour is obtained by optionally conditioning selected wheat grains and then grinding them whole using a grinder such as a pin mill, hammer mill, or jet mill to produce flour containing all of the wheat grains, including the epidermis, germ, and endosperm; alternatively, by optionally conditioning selected wheat grains and then grinding them multiple times using a roll mill to fractionate them into a fine fraction of the endosperm (wheat flour, hereinafter referred to as the "endosperm fraction"), a germ fraction, and a coarse fraction containing the outer layer of the endosperm (wheat bran), and then finely grinding the germ fraction and / or coarse fraction either directly or using a grinder such as a pin mill, hammer mill, jet mill, or grinder mill to obtain a germ fraction and a wheat bran fraction, which are then mixed in the composition ratio of the wheat grain. While whole wheat flour is rich in nutrients, it has a bran smell and a harsh taste, and when used to make noodles, it gives the noodles a brittle, inelastic texture, making them less tasty. Patent Document 1 (JP 2001-204411 A) discloses a method for producing a whole wheat flour composition in which raw wheat grains are ground and separated into three fractions: raw bran, raw germ, and wheat flour; the raw bran fraction and raw germ fraction are separately roasted and ground; and the resulting mixture is combined with wheat flour. It is described that spaghetti with excellent texture and flavor is obtained. Patent Document 2 (JP 2015-195759 A) discloses a method for producing noodles using whole wheat flour comprising a fine powder fraction and a coarse powder fraction of specific particle sizes. It is described that noodles with a smooth, elastic noodle strand surface and good loosening properties are obtained. While both methods are excellent technologies, they require complicated procedures, and further improvements are needed. Patent Document 3 (JP 2015-181463 A) discloses a method for producing heat-treated whole grain flour, which includes a step of heat-treating the entirety of whole grain flour obtained by grinding grains, and in the examples it is described that hotcakes made using heat-treated whole grain flour obtained by moist heat-treating whole wheat flour produced from soft wheat had reduced bitterness and a good texture. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2001-204411 [Patent Document 2] Patent Publication No. 2015-195759 [Patent Document 3] Patent Publication No. 2015-181463 Summary of the Invention [Problem to be solved by the invention]

[0004] To provide a method for producing dry-heat-treated whole wheat flour, which can produce wheat flour processed foods such as noodles with reduced bran odor and excellent elasticity. [Means for solving the problem]

[0005] The present inventors milled wheat kernels to obtain whole wheat flour, and then dry-heat-treated the dry-heat-treated whole wheat flour under specific conditions to produce wheat processed foods such as noodles. They found that not only was the bran odor reduced, but the wheat processed foods had excellent elasticity, and thus completed the present invention. That is, the present invention provides the following. [1] milling wheat kernels to obtain whole wheat flour; and A method for producing dry-heat-treated whole wheat flour, comprising the step of dry-heat-treating the whole wheat flour at an ambient temperature of 90 to 130°C for 1 to 20 minutes. [2] Obtaining dry-heat-treated whole wheat flour by the method described in [1]; and A method for producing a flour composition, comprising the step of adding wheat flour to the dry-heat-treated whole wheat flour and mixing them. [3] The method for producing a wheat flour composition according to [2], wherein the dry-heat-treated whole wheat flour is for noodles. [4] A method for producing noodles, comprising producing dry-heat-treated whole wheat flour by the method described in [1] or producing a wheat flour composition by the method described in [2], and producing noodles from the dry-heat-treated whole wheat flour or the wheat flour composition. [Effects of the Invention]

[0006] According to the present invention, dry heat treatment reduces the bran odor and inhibits gluten inactivation, thereby making it possible to provide wheat processed foods such as noodles that are excellent in flavor and elasticity. DETAILED DESCRIPTION OF THE INVENTION

[0007] (Method of manufacturing dry-heat-treated whole wheat flour) The present invention relates to a method for producing dry-heat-treated whole wheat flour, which comprises milling wheat kernels to obtain whole wheat flour and dry-heat treating the whole wheat flour for 1 to 20 minutes at an ambient temperature of 90 to 130°C. Preferably, the dry-heat-treated whole wheat flour is for use in noodles, and the present invention relates to a method for producing dry-heat-treated whole wheat flour for noodles.

[0008] The manufacturing method of the present invention includes a step of milling wheat kernels to obtain whole wheat flour. Wheat kernels generally consist of the endosperm, germ, and the outer layer covering the endosperm and germ. The outer layer refers to the portion extending from the aleurone layer in contact with the endosperm to the outermost layer, and is arranged in the following order from the endosperm side: aleurone layer, nucellus, testa, tubular cells, transverse cells, hypodermis, and epidermis (each layer may be referred to by a different name). The outer layer consists of six layers extending from the nucellus to the epidermis, and is called "bran." The pericarp consists of four layers extending from the tubular cells to the epidermis. The aleurone layer separates the endosperm from the outer layer. It is a special layer that does not contain starch but is rich in protein, lipids, and ash (minerals). In the case of wheat kernels, the outer layer, aleurone layer, and endosperm account for 6-8% by mass, 6-7% by mass, and 81-85% by mass, respectively. During the milling process, the aleurone layer is separated from the endosperm together with the husk (bran). In this invention, the outer layer consisting of the aleurone layer and the husk is referred to as "wheat bran" to distinguish it from "bran," which simply refers to the husk. Although this may vary slightly depending on growing conditions and varieties, the composition ratio of endosperm, wheat bran, and germ in wheat kernels is approximately 83:15:2 (by mass).

[0009] Whole wheat flour means flour containing the above-mentioned constituent components of wheat kernels in substantially the same constituent ratios as those mentioned above. Examples of methods for milling wheat grains to obtain whole wheat flour include a method in which the endosperm, wheat bran, and germ are all milled together without being separated during the milling process (Production Method 1), and a method in which the milled material is fractionated into three fractions, the endosperm fraction, the wheat bran fraction, and the germ fraction, and optionally the wheat bran fraction and / or the germ fraction is further finely milled and then the three fractions are mixed to obtain whole wheat flour (Production Method 2). Specifically, in Production Method 1, selected wheat grains are optionally tempered and milled in an impact mill such as a pin mill or jet mill to obtain whole wheat flour. In production method 2, selected wheat kernels are optionally conditioned and pulverized using a roll mill or similar. The pulverized material is then fractionated using a sifter or similar device into three fractions: an endosperm fraction (wheat flour), a wheat bran fraction containing large wheat bran fragments, and a germ fraction. The fractions are then optionally conditioned and re-pulverized using a pin mill, jet mill, grinder mill, or similar device to obtain fine particles. These three fractions are then mixed together in approximately the same proportions as the wheat kernels to obtain whole wheat flour. In production method 2, each fraction may be derived from the same variety or brand of raw grain (e.g., all fractions derived from GA-SX wheat), or each may be derived from a different variety or brand of raw grain (e.g., the three fractions are derived from ASW, DNS, and WW, respectively). The method for pulverizing the wheat kernels is not particularly limited, and known pulverization methods, such as roll milling, impact milling, and mortar milling, can be used.

[0010] In the present invention, the wheat grains used to obtain whole wheat flour may be any known type. Specifically, any wheat grain of a variety or brand used for food production can be suitably used, regardless of origin. Examples include Dark Northern Spring (DNS), Hard Red Winter (HRW), Hard Red Spring (HRS), No. 1 Canada Western Red Spring (1CW), Western White (WW), Prime Hard (PH), Australian Standard White (ASW), durum wheat, Kitahonami, Yumechikara, Minaminokaori, Shiroganekomugi, Bermude, Arlequin, and Apache. Preferably, the wheat grains used are hard wheat grains with a protein content of 12 to 15% by mass, which are used for noodle production. Alternatively, commercially available whole wheat flour may be used.

[0011] The production method of the present invention includes a step of dry-heat treating the whole wheat flour at an ambient temperature of 90 to 130°C for 1 to 20 minutes to obtain dry-heat-treated whole wheat flour. Here, dry-heat treatment refers to heating an object without supplying moisture or water vapor, and is a heat treatment that actively evaporates the moisture in the object. Examples of heat treatment methods include exposing whole wheat flour to gas- or solid-mediated conductive heat, radiant heat, reflected heat, hot air, electromagnetic waves (microwaves), or the like. Examples of devices and machines that perform dry heat treatment include confectionery and bakery ovens, reel ovens, roasting kilns, high-temperature dryers, hot air dryers, heating mixers, indirect heating dryers, microwave generators, etc. Dry-heat-treated whole wheat flour can be obtained by using such devices and machines to maintain whole wheat flour in a high-temperature, low-humidity environment. In this case, to ensure that the whole wheat flour is dry-heat-treated uniformly, it is preferable to mix and stir the flour at appropriate times using an air current or a mixer, or to spread the whole wheat flour thinly enough to prevent uneven heat conduction. The treatment temperature for dry heat treatment of whole wheat flour is an ambient temperature of 90 to 130°C, preferably 95 to 125°C, and more preferably 100 to 120°C. If the ambient temperature for dry heat treatment is less than 90°C, the whole wheat flour will not be modified effectively, while if it exceeds 130°C, the whole wheat flour will be in a roasted state, which will affect gluten denaturation and tend to weaken the elasticity of the resulting noodles. The treatment time for dry heat treatment can be adjusted as appropriate, but is usually 1 to 20 minutes, preferably 3 to 17 minutes, more preferably 5 to 15 minutes, and even more preferably 7 to 12 minutes. If the treatment temperature is less than 1 minute, the whole wheat flour will not be modified effectively, while if it exceeds 20 minutes, gluten denaturation will tend to weaken the elasticity of the resulting noodles. The cooling method after the dry-heat treatment is not particularly limited, and may be natural heat dissipation, forced rapid cooling by ventilation or indirect water flow, or the like. The cooling time may also be adjusted appropriately until the temperature of the dry-heat-treated whole wheat flour drops to about room temperature. By setting the dry-heat treatment temperature and time within the above ranges, it is possible to minimize denaturation of gluten contained in whole wheat flour, thereby maintaining elasticity and suppressing the bran odor. Such dry-heat-treated whole wheat flour can be suitably used for producing noodles, as well as any wheat flour processed food that utilizes the elasticity of gluten.

[0012] (Method of producing flour composition) The present invention also relates to a method for producing a wheat flour composition, comprising the steps of obtaining dry-heat-treated whole wheat flour by the aforementioned method and adding wheat flour to the dry-heat-treated whole wheat flour. Preferably, the present invention relates to a method for producing a wheat flour composition for noodles, comprising the steps of obtaining dry-heat-treated whole wheat flour for noodles by the aforementioned method and adding wheat flour to the dry-heat-treated whole wheat flour for noodles. Wheat flour refers to the pulverized endosperm fraction obtained by milling wheat kernels and fractionating the resulting pulverized material using a sifter, classifier, or the like. Generally, milling to obtain wheat flour involves a multi-stage pulverization process, with flour with high endosperm purity being obtained in the early stages and flour with low endosperm purity being obtained in the later stages, which is contaminated with the outer layer of the wheat kernel. Flours with increasing endosperm purity are referred to as first-grade flour, second-grade flour, third-grade flour, and final flour. There are no particular limitations on the type of wheat flour used in the wheat flour composition of the present invention, but first-grade flour is preferred. The wheat grains used to obtain the wheat flour used in the present invention may be any known type. Specifically, any wheat grain of a variety or brand used for food production can be suitably used, regardless of origin. Examples include Dark Northern Spring (DNS), Hard Red Winter (HRW), Hard Red Spring (HRS), No. 1 Canada Western Red Spring (1CW), Western White (WW), Prime Hard (PH), Australian Standard White (ASW), durum wheat, Kitahonami, Yumechikara, Minaminokaori, Shirogane Komugi, Bermude, Arlequin, and Apasche. Such wheat flour can be selected appropriately depending on the type of wheat-based processed food desired. In the case of noodles, wheat flour derived from hard wheat grains with a protein content of 12 to 15% by mass, which is used for noodle production, is preferred. Alternatively, commercially available whole wheat flour may be used. Also, commercially available weak flour, medium-strength flour, semi-strength flour, or strong flour, or a mixture of these, may be used. In the present invention, the flour composition comprises dry-heat-treated whole wheat flour and wheat flour. Preferably, the flour composition consists of dry-heat-treated whole wheat flour and wheat flour. The amount of dry-heat-treated whole wheat flour relative to the total amount of the flour composition can be appropriately changed depending on the type of wheat flour processed food desired. In the case of noodles, the lower limit of the amount of dry-heat-treated whole wheat flour relative to the total amount of the flour composition is generally preferably 5% by mass, more preferably 10% by mass, even more preferably 15% by mass, even more preferably 20% by mass, and most preferably 30% by mass, while the upper limit of the amount of dry-heat-treated whole wheat flour relative to the total amount of the flour composition is preferably 100% by mass, more preferably 80% by mass, even more preferably 60% by mass, even more preferably 50% by mass, and most preferably 40% by mass. For example, in the case of Chinese noodles, the amount is preferably 5% by mass or more, and more preferably 15% by mass or more.

[0013] (Noodle manufacturing method) The present invention further relates to a method for producing noodles, which comprises producing dry-heat-treated whole wheat flour by the above-mentioned method, or producing a wheat flour composition by the above-mentioned method, and producing noodles from the dry-heat-treated whole wheat flour or the wheat flour composition. The method for producing noodles in the present invention is not particularly limited, and noodles can be produced according to any known method, except that noodles are produced from the dry-heat-treated whole wheat flour obtained by the above-mentioned method or the wheat flour composition obtained by the above-mentioned method. For example, water and other ingredients can be added to a noodle-making powder ingredient primarily composed of the wheat flour composition, followed by kneading to prepare a dough; the resulting dough can then be aged, shaped, combined, and rolled using a noodle-making roll to produce a noodle sheet, which can then be cut out with cutting blades to produce noodle strands (raw noodles). Multilayer noodles can also be produced by layering the noodle sheet obtained by shaping and optionally combining using a noodle-making roll with a noodle sheet obtained in the same manner using other noodle-making powder ingredients with different constituents. Alternatively, noodle strands can be obtained by extrusion. The resulting noodle strands can also be dried to produce dried noodles. Examples of noodles obtainable by the production method of the present invention include Chinese noodles, udon, hiyamugi, somen, Japanese soba, pasta, and rice vermicelli.

[0014] In the present invention, when producing noodles, auxiliary raw materials and secondary materials that are usually used in the production of noodles can be used in addition to the wheat flour composition. Such secondary raw materials and secondary ingredients include flour derived from grains such as rice, rye, barley, corn, buckwheat, soybeans, mung beans, barnyard millet, foxtail millet, and amaranth; bran and other bran products such as wheat bran and rice bran; starches separated and refined from the above grains, tubers (potatoes, taro, cassava, etc.), tuberous roots (sweet potatoes, yams, etc.), and trunks (sago palm, etc.), as well as their waxy or high-amylose varieties; processed starches obtained by pregelatinizing, etherifying, esterifying, acetylating, cross-linking, etc., the above starches; water-insoluble dietary fiber such as resistant starch; water-soluble dietary fiber such as polydextrose, barley beta-glucan, and resistant dextrin; starch hydrolysates such as dextrin; sugars such as glucose, fructose, lactose, sugar, and isomaltose; egg yolks, egg whites, whole eggs, and their powdered forms, as well as other egg-derived starches. These include egg ingredients; dairy ingredients such as powdered milk, skim milk powder, and soy milk powder; fats and oils such as shortening, lard, margarine, butter, and liquid oil; protein materials such as soy protein, wheat protein, and mung bean protein; emulsifiers such as glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, propylene glycol fatty acid esters, sorbitan fatty acid esters, lecithin, saponin, sodium caseinate, organic acid monoglycerides, and organic acid diglycerides; thickening polysaccharides such as pectin, carrageenan, xanthan gum, guar gum, tara gum, locust bean gum, and inulin; cellulose derivatives such as methylcelluloses; inorganic salts such as alkaline water and salt; vitamins such as vitamin B and vitamin C; pH adjusters; preservatives; flavorings; and fortifiers such as calcium. These auxiliary ingredients and auxiliary materials can also be appropriately blended with the wheat flour composition for noodles of the present invention to prepare a noodle premix flour. [Example]

[0015] EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. Production Example 1: Production of dry-heat-treated whole wheat flour Whole wheat flour was obtained by feeding 1CW wheat kernels into a pin mill without adjusting the moisture content. The protein content of the whole wheat flour measured by the Kjeldahl method was 13% by mass. The whole wheat flour was placed in a paddle dryer (Nara Machinery Works, Ltd.) set at an internal temperature (ambient temperature) of 110°C and dry-heat treated for 10 minutes. After the dry-heat treatment, the flour was allowed to cool naturally in an open system to obtain dry-heat-treated whole wheat flour.

[0016] Production Example 2: Production of Chinese noodles 20 parts by mass of dry-heat-treated whole wheat flour, 80 parts by mass of wheat flour (Tokuju, Nippon Flour Mills Co., Ltd.), 1 part by mass of salt, 1 part by mass of alkaline mineral water, and 33 parts by mass of water were placed in a mixer (Tokyo Menki Co., Ltd.) and mixed for 13 minutes to obtain dough. The obtained dough was shaped once, combined once, and rolled three times using a noodle roll (Tokyo Menki Co., Ltd.) to form a noodle sheet with a thickness of 1.5 mm, which was then cut using a #20 square cutting blade to obtain fresh noodles 25 cm long.

[0017] Evaluation example 1: Sensory evaluation of boiled noodles Fresh noodles were boiled for 3 minutes in boiling water (pH 5.5-6.0) 15 times the mass of the fresh noodles, drained, and then served in a bowl containing soy sauce-based soup. Ten experienced panelists evaluated the bran odor and springiness using the following criteria, and the average score and standard deviation (SD) were calculated. The bran odor and springiness of Chinese noodles made from untreated whole wheat flour and wheat flour that had not been dry-heat treated were each given a score of 3 (Reference Example 1).

[0018] Bran odor TIFF0007721267000001.tif31140

[0019] elasticity TIFF0007721267000002.tif31140

[0020] Test Example 1: Examination of heat treatment time Dry-heat-treated whole wheat flour was obtained according to Production Example 1, except that the heat treatment temperature (temperature inside the oven) during dry-heat treatment was 110°C and the heat treatment time was as shown in Table 1. Chinese noodles were produced according to Production Example 2 and evaluated according to Evaluation Example 1. The results are shown in Table 1. As a result, the bran odor in Examples 1 to 4 was reduced as the heat treatment time increased. The springiness of the Chinese noodles in Examples 1 to 3 increased as the heat treatment time increased. In Example 4, the springiness was weaker than in Example 3, perhaps because the heat treatment time was too long, but it was stronger than in Reference Example 1. In Comparative Example 1, where the heat treatment time was 0.5 minutes, the results were equivalent to Reference Example 1, and no effect of the dry heat treatment was obtained. In Comparative Example 2, where the heat treatment time was 25 minutes, the dry heat treatment time was too long, resulting in a roasted state, and although the bran odor was satisfactorily reduced, the springiness of the Chinese noodles was weakened, making them unsuitable. From the above, it was found that the bran odor of whole wheat flour can be reduced by dry heat treatment, and that moderate dry heat treatment increases the elasticity of gluten, while excessive dry heat treatment denatures and inactivates the gluten, resulting in a loss of elasticity.

[0021] Table 1 TIFF0007721267000003.tif57144

[0022] Test Example 2: Examination of heat treatment temperature Dry-heat-treated whole wheat flour was obtained according to Production Example 1, except for the heat treatment temperature and time shown in Table 2. Chinese noodles were produced according to Production Example 2 and evaluated according to Evaluation Example 1. The results are shown in Table 2. As a result, in Examples 3 and 6 to 9, which had a heat treatment time of 10 minutes, the bran odor decreased as the heat treatment temperature increased, and the elasticity of the Chinese noodles increased, peaking at a heat treatment temperature of 110°C. In Example 5, where the heat treatment temperature was 90°C and the heat treatment time was 1 minute, both the bran odor and elasticity were slightly improved. In Example 10, where the heat treatment temperature was 130°C and the heat treatment time was 20 minutes, the Chinese noodles had the same elasticity as the Reference Example, but the bran odor was effectively weakened, resulting in a good overall result. In Comparative Example 3, where the heat treatment temperature was 80°C and the heat treatment time was 10 minutes, no effect was obtained due to insufficient dry heat treatment. In Comparative Example 4, where the heat treatment temperature was 140°C and the heat treatment time was 10 minutes, the dry heat treatment temperature was too high, resulting in a roasted state, and the elasticity was weakened, possibly due to gluten denaturation.

[0023] Table 2 TIFF0007721267000004.tif78155

[0024] Test Example 3: Evaluation of Chinese noodles made using only dry-heat-treated whole wheat flour When Chinese noodles produced using only the dry-heat-treated whole wheat flour obtained in Production Example 1 (heat treatment temperature: 110°C, heat treatment time: 10 minutes) were evaluated, the bran odor was reduced compared to Chinese noodles produced using only untreated whole wheat flour that had not been dry-heat-treated, and the noodles had good elasticity, which was a similar trend to that observed when Example 3 and Reference Example 1 were compared.

[0025] Test Example 4: Examination of types of heat treatment Dry-heat-treated whole wheat flour was obtained according to Production Example 1, except for the heat treatment temperature and time shown in Table 3 below. Moisture-heat-treated whole wheat flour was produced in accordance with JP 2014-050367 A. Specifically, the whole wheat flour obtained according to Production Example 1 was spread on a tray to a thickness of 1 cm so that the heated steam would reach the entire wheat flour evenly, and then placed in a steam oven (manufactured by RATIONAL) set to the temperature shown in the table below. Moisture-heat-treated whole wheat flour was obtained by moist-heat-treating the flour under normal pressure for the time shown in the table below. Chinese noodles were produced according to Production Example 2 and evaluated according to Evaluation Example 1. The results are shown in Table 3. As a result, in Example 11, which was dry-heat treated at 90°C, the bran odor was reduced depending on the heat treatment time, and the springiness of the Chinese noodles was increased. In Example 12, which was dry-heat treated at 130°C, the bran odor was reduced, and the springiness of the Chinese noodles was increased compared to Example 9. In Comparative Examples 5 to 8, which were wet-heat treated, the bran odor was reduced, but the springiness was lost under all of the wet-heat treatment conditions, possibly due to inactivation of gluten.

[0026] Table 3 TIFF0007721267000005.tif57133

Claims

1. milling the wheat kernels to obtain whole wheat flour; and A method for producing dry-heat-treated whole wheat flour, comprising the step of dry-heat-treating the whole wheat flour at an ambient temperature of 90 to 130°C for 5 to 17 minutes.

2. Obtaining dry-heat treated whole wheat flour by the method of claim 1; and A method for producing a flour composition, comprising the step of adding wheat flour to the dry-heat-treated whole wheat flour.

3. The method for producing a wheat flour composition according to claim 2, wherein the dry-heat-treated whole wheat flour is for use in noodles.

4. A method for producing noodles, comprising producing dry-heat-treated whole wheat flour by the method of claim 1 or producing a wheat flour composition by the method of claim 2, and producing noodles from the dry-heat-treated whole wheat flour or the wheat flour composition.

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