Method for producing pregelatinized grain flours

Abstract

To provide pregelatinized grain flours capable of improving the taste and texture of foods and imparting aging resistance to the foods.SOLUTION: A method for producing pregelatinized grain flours comprises: a slurry heating step of heating a slurry containing 100 pts.mass of raw grain flours, 0.1 to 3 pts.mass of polysaccharides, and 500 pts.mass or more of water under conditions where the product temperature of the slurry becomes 90°C or higher; and a step of drying the slurry that has been through the slurry heating step to obtain a solid matter, wherein in the slurry heating step, the slurry is stirred while being heated.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing gelatinized flour suitable for food applications. [Background technology]

[0002] Pregelatinized starch is obtained by heating raw starch in the presence of moisture to gelatinize it (gelatinize it). Pregelatinization causes the molecular arrangement inside the starch granules to collapse, resulting in irreversible changes in properties such as swelling of the starch granules, loss of birefringence, melting of natural microcrystals, and solubilization of starch. For this reason, pregelatinized starch exhibits unique properties different from those of raw starch, and is widely used in food applications and industrial applications. As a method for producing pregelatinized starch, a method of drying starch slurry using a spray dryer, drum dryer, etc. is known. Other known methods include a method of adding water to starch and heating it while kneading it in an extruder, and a method of heating and humidifying it by passing superheated steam through a container containing starch.

[0003] Patent Document 1 describes a method for producing noodles, which comprises a process for producing gelatinized grain flour and a process for preparing noodle dough using grain flour containing a specific amount of gelatinized grain flour produced in the process. The process for producing gelatinized grain flour comprises a slurry heating process in which a slurry containing 100 parts by mass of raw grain flour and 500 parts by mass or more of water is heated under conditions such that the product temperature of the slurry is 90°C or higher, and a process in which the slurry that has undergone the slurry heating process is dried to obtain a solid product.

[0004] Patent Document 2 describes a method for producing gelatinized grain flour, which includes a gelatinization step in which a slurry containing 100 parts by mass of grain flour and 500 parts by mass or more of water is heated under conditions such that the product temperature of the slurry is 90°C or higher to gelatinize the starch contained in the grain flour, and a step in which the slurry that has undergone the gelatinization step is dried to obtain a solid, and in the gelatinization step, the slurry is stirred while being heated. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2022 / 230840 [Patent Document 2] International Publication No. 2021 / 084663 Summary of the Invention [Problem to be solved by the invention]

[0006] Starch retrogradation is a problem for foods that contain starch. For example, raw or cooked noodles are often transported, sold, or stored in a frozen, refrigerated, or chilled state, and in such cases, there is a problem that the original taste and texture of the noodles, which have excellent viscoelasticity, is lost over time. Starch retrogradation is a phenomenon in which pregelatinized starch releases the moisture it has contained and changes into beta crystals. There is a demand for technology that can improve the taste and texture of foods to a high level and suppress deterioration over time, such as retrogradation.

[0007] An object of the present invention is to provide a pregelatinized starch which can improve the taste and texture of foods and also impart resistance to retrogradation to foods. [Means for solving the problem]

[0008] The present invention relates to a slurry heating process in which a slurry containing 100 parts by mass of raw grain flour, 0.1 to 3 parts by mass of polysaccharides, and 500 parts by mass or more of water is heated under conditions such that the product temperature of the slurry is 90 ° C. or higher; and drying the slurry that has been subjected to the slurry heating step to obtain a solid matter. In the method for producing gelatinized flour, the slurry is stirred during heating in the slurry heating step.

[0009] The present invention also relates to a method for producing processed foods, which uses the gelatinized grain flour produced by the above-mentioned production method. Effect of the Invention

[0010] According to the present invention, it is possible to provide a pregelatinized starch that can improve the taste and texture of foods and impart aging resistance to foods, and the pregelatinized starch is particularly suitable for use in noodles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The method for producing gelatinized flour of the present invention includes a step of heating a slurry containing raw flour, polysaccharides, and water (slurry heating step), and a step of drying the slurry that has been through the slurry heating step to obtain a solid (slurry drying step). The slurry heating step causes the starch contained in the raw flour in the slurry to be gelatinized, and the raw flour becomes gelatinized flour. Therefore, the slurry heating step can also be called a gelatinization step.

[0012] The method for producing gelatinized flour of the present invention typically comprises a step of preparing a slurry to be heated in the slurry heating step (slurry preparation step). That is, the method for producing gelatinized flour of the present invention typically comprises a slurry preparation step, a slurry heating step (gelatinization step), and a slurry drying step, each step being carried out in this order.

[0013] As the raw flour used in the slurry preparation step, basically, any flour that can be used for food production can be used without any particular restrictions. In this specification, "flour" refers to a powdery substance derived from grains at room temperature and normal pressure, and is a concept that includes flour and starch. "Starch" as used here refers to "pure starch" isolated from plants such as wheat, and is distinguished from starch that is inherently present in flour or whole grain flour. In addition, the grain from which "flour" is derived may be not only cereals (seeds of grass plants), but also pseudocereals (seeds of dicotyledonous plants), pulses (seeds of legume plants), potatoes (edible tuberous roots or tubers), etc., as long as they contain starch as an ingredient.

[0014] The raw material flour (flour, starch) used in the slurry preparation step may be any flour containing starch, regardless of the amount of amylose, and may be either non-glutinous or glutinous in the case of a grass plant. The raw material flour used in the slurry preparation step may be one type or two or more types. Specific examples of flour include flours mainly composed of endosperm, such as wheat flour (specifically, for example, strong flour, medium flour, weak flour, durum wheat flour, and durum semolina), rice flour, buckwheat flour, rye flour, soy flour, barley flour, and corn flour, as well as flours containing at least the outer skin and / or germ, such as "bran" mainly composed of the outer skin, and "whole wheat flour" containing the three main components of the endosperm, outer skin, and germ. Specific examples of bran and whole wheat flour include wheat bran and whole wheat flour, which are derived from wheat. However, bran has a relatively low starch content and is somewhat inferior in suitability as a raw material for the gelatinized flours targeted in the present invention, so it is preferable to use grain flours other than bran as the raw material flours used in this process. Specific examples of starch include unmodified starches such as potato starch, wheat starch, corn starch, waxy corn starch, rice starch, and tapioca starch; and modified starches obtained by subjecting unmodified starch to one or more of the following treatments: oil / fat processing, etherification, esterification, acetylation, cross-linking, oxidation, and the like.

[0015] The raw flour used in the slurry preparation step is typically unprocessed flour that has not been subjected to pretreatment such as heating, but raw flour that has been pretreated can also be used. Examples of the pretreatment include a process in which various flour modifiers are added to the raw flour. The flour modifier is an agent that can modify the flour to desired properties, and examples of the flour modifier include enzymes, acid or alkali agents, emulsifiers, catalysts, sugars, amino acids, peptides, thickening agents such as thickening polysaccharides, and the like. Examples of the enzyme include amylase, protease that breaks down proteins contained in flour, and the like.

[0016] The raw flour used in the slurry preparation step preferably contains starch. As mentioned above, "starch" refers to "pure starch" isolated from plants such as wheat. The use of starch as a raw material for gelatinized flour is advantageous in that the slurry does not foam and is therefore easy to handle, especially compared to the use of flour such as wheat flour.

[0017] In the slurry preparation step, 500 parts by mass or more of water is added to 100 parts by mass of raw flour to prepare a slurry. By adding such a relatively large amount of water to the flour-containing slurry, the side chains of the starch contained in the flour are likely to open in the subsequent drying step of the slurry, and as a result, it is presumed that a superior effect is achieved in terms of improving the aging resistance of the starch compared to conventional manufacturing methods. If the amount of water added is less than 500 parts by mass to 100 parts by mass of flour, the desired effect of the present invention is not achieved.

[0018] In the slurry preparation step, the amount of water added per 100 parts by mass of the raw grain flour is preferably 600 to 2500 parts by mass, more preferably 700 to 2000 parts by mass, and even more preferably 800 to 1500 parts by mass. If the amount of water added is too much, a lot of time and energy will be required to obtain a solid in the subsequent drying step of the slurry, which may lead to an increase in production costs and a decrease in production efficiency.

[0019] In the slurry preparation step, a specific amount of polysaccharides is also added to the flour-containing slurry. When the flour-containing slurry contains a specific amount of polysaccharides, it is believed that when the starch in the flour is gelatinized by heating, the polysaccharides interact with the amylose and amylopectin in the starch, and as a result, it is presumed that a superior effect is achieved in terms of improving the aging resistance of the starch compared to when the flour-containing slurry does not contain polysaccharides. Even if gelatinized flour is obtained from a flour-containing slurry that does not contain polysaccharides and the gelatinized flour is used in combination with polysaccharides in the production of processed foods, the remarkable effect cannot be obtained as when gelatinized flour obtained from a flour-containing slurry that contains polysaccharides is used.

[0020] In the slurry preparation step, the amount of polysaccharide added is 0.1 to 3 parts by mass, preferably 0.1 to 2 parts by mass, per 100 parts by mass of the raw grain flour. If the amount of polysaccharide added is too small, the intended effect of the present invention may not be sufficiently obtained, whereas if the amount of polysaccharide added is too large, the food may feel sticky or slimy when eaten.

[0021] Examples of polysaccharides include xanthan gum, guar gum, mannan, propylene glycol alginate, tamarind seed gum, gum arabic, locust bean gum, tragacanth gum, karaya gum, gellan gum, pectin, pullulan, carrageenan, agar, crystalline cellulose, methylcellulose, carboxymethylcellulose, hydroxypropylated methylcellulose, etc., and these can be used alone or in combination of two or more. Among these, it is preferable to use one or more selected from the group consisting of xanthan gum, guar gum, mannan, and propylene glycol alginate. Xanthan gum and guar gum are preferred because they are highly cost-effective. Mannan and propylene glycol alginate are preferred because they can achieve high usage effects even in small amounts. In the present invention, the above-mentioned starch does not fall under the category of polysaccharides.

[0022] The slurry prepared in the slurry preparation step typically contains only the raw flour, polysaccharides, and water as a solvent, but may contain other components, such as a flour modifier that can be used in the pretreatment of the raw flour, as necessary. In this case, 1) a flour modifier that is the same as or different from the flour modifier may be contained in a slurry containing flour pretreated with the flour modifier, or 2) a flour modifier may be contained in a slurry containing raw flour. In addition, in a slurry containing a flour modifier, a reaction involving the flour modifier, such as an enzyme reaction, occurs, and this reaction may be completed before the slurry is subjected to the next drying step, or may occur during the drying step.

[0023] In the slurry heating step, the slurry prepared in the slurry preparation step is heated, and in order to achieve the desired effects of the present invention, the slurry needs to be heated under conditions that bring the product temperature of the slurry to 90° C. or higher. As described above, in the present invention, a highly hydrated slurry is prepared by adding 500 parts by mass or more of water to 100 parts by mass of raw material flour, which is presumed to contribute in no small way to making the side chains of the starch contained in the raw material flour more easily open and ultimately to improving the retrogradation resistance of the starch, and by heating this highly hydrated slurry under the above conditions, it is possible to produce high quality gelatinized flour while suppressing heat damage to the open starch side chains.

[0024] The higher the heating temperature of the slurry, the more the starch is modified and the more easily the desired effects of the present invention are achieved, but if the heating temperature is too high, the pressure inside the container containing the slurry must be controlled and the amount of heat required for steam, etc. must be increased, which may lead to an increase in production costs and a decrease in productivity. In consideration of this, the product temperature of the slurry during heating in the slurry heating step is preferably 100° C. or higher, more preferably 105° C. or higher, even more preferably 110 to 140° C., even more preferably 115 to 135° C., and even more preferably 120 to 130° C. Heating under conditions where the product temperature of the slurry exceeds 100° C. can be performed, for example, by heating the slurry in a pressurized atmosphere.

[0025] In the slurry heating step, the heating time of the slurry (the time for maintaining the product temperature) is preferably 1 minute or more, more preferably 3 minutes or more, from the viewpoint of more reliably achieving the desired effects of the present invention. On the other hand, the upper limit of the heating time in the gelatinization step is preferably 180 minutes or less, more preferably 120 minutes or less, from the viewpoint of production efficiency.

[0026] The method of heating the slurry in the slurry heating step is not particularly limited as long as it can handle the conditions of high water content and high temperature. A typical method of heating the slurry is to place a slurry containing flour and polysaccharides in a container and heat the container. The slurry may be heated in a batch or continuous manner. Examples of the container in which the slurry is heated include a pressure cooker in the case of adopting a batch method and a line mixer such as a static mixer in the case of adopting a continuous method. The heating means is also not particularly limited, and examples include electric, gas, and steam types, and one or more of these can be used alone or in combination. Examples of the method of heating the slurry using a steam heating means include a method of directly introducing saturated steam or superheated steam into a container in which the material to be dried (flour) is placed.

[0027] In the slurry heating step, the slurry is stirred while being heated. If the slurry is heated without stirring and left to stand, the cereal flours contained in the slurry may become lumpy, and the gelatinization of starch may be insufficient and non-uniform. However, by stirring the slurry during heating, such inconveniences can be prevented and the gelatinization of starch can be promoted. The method of stirring the slurry is not particularly limited as long as it can disperse the cereal flours contained in the slurry throughout the entire slurry. Typically, the method can be carried out according to a conventional method using a known vessel with a stirrer, which is equipped with a vessel and a stirrer for stirring the contents of the vessel. For example, when the slurry is heated in a batch manner, a device having a stirring blade can be exemplified, and when the slurry is heated in a continuous manner, a static mixer can be exemplified. In addition, a known ultrasonic vibration generating means can be used as the slurry stirring means, and in this case, the slurry is stirred by generating fine bubbles in the slurry by the vibration of ultrasonic waves generated from the ultrasonic vibration generating means. Alternatively, instead of using an agitator such as an agitating blade, the slurry may be agitated during heating by blowing a gas such as steam into the slurry.

[0028] The slurry heating step is preferably completed when the slurry to be heated contains 500 parts by mass or more of water per 100 parts by mass of raw grain flour. The reason for this is that if the water content of the slurry after the slurry heating step (the slurry to be subjected to the subsequent slurry drying step) is so small as to be less than 500 parts by mass per 100 parts by mass of raw grain flour, the gelatinization of starch in the raw grain flour is suppressed in the slurry heating step, and the intended effect of the present invention may not be achieved.

[0029] As described above, one example of a method for completing the slurry heating step when the slurry to be heated contains 500 parts by mass or more of water per 100 parts by mass of raw flour is a method for heating the slurry in a pressurized atmosphere, i.e., under an atmospheric pressure of more than 1 atmosphere. In this case, the container for containing the slurry is preferably pressure-resistant. The pressure of the pressurized atmosphere is not particularly limited and may be appropriately adjusted depending on the amount of solvent contained in the slurry and the heating temperature (product temperature of the slurry). Since the upper limit temperature of the slurry during heating depends on the pressure, it is preferable to set the pressure corresponding to the desired heating temperature.

[0030] In the slurry drying step, the slurry heated in the slurry heating step is dried to obtain a solid material containing gelatinized cereal flours. The method for drying the slurry is not particularly limited, and known drying methods can be used, such as freeze drying, spray drying using a spray dryer, and heat drying using a drum dryer. The degree of drying of the slurry is not particularly limited, but typically, the slurry is dried until the moisture content of the solid material obtained by drying the slurry is approximately the same as the moisture content of the raw cereal flour used in the slurry preparation step, more specifically, until it is approximately 15% by mass.

[0031] The solid matter of the slurry obtained through the slurry drying step may be used as it is as gelatinized grain flour, or may be pulverized into powder. The pulverization of the solid matter can be carried out in a conventional manner using a household pulverizer such as a coffee mill or a juicer, or an industrial pulverizer such as a hammer mill, a pin mill, or a jet mill, and the solid matter may be pulverized to the desired particle size.

[0032] The degree of gelatinization (gelatinization degree) of the obtained gelatinized flours can be preferably 90% or more, more preferably 95% or more. By incorporating such gelatinized flours with a high degree of gelatinization into food, the taste and texture of the food are significantly improved, and further, excellent aging resistance is imparted to the food. In this specification, the degree of gelatinization refers to the degree of gelatinization measured by the BAP method (β-amylase-pullulanase method). The measurement of the degree of gelatinization by the BAP method can be carried out as follows, in accordance with a previous report (Kasei Gaku Zasshi 32(9), 653-659, 1981).

[0033] [Method for measuring degree of gelatinization using the β-amylase-pullulanase method] (A) Reagents The reagents used are as follows: 1) 0.8M acetic acid-Na acetate buffer 2) 10N sodium hydroxide solution 3) 2N acetic acid solution 4) Enzyme solution: 0.017 g of β-amylase (Nagase Chemtex Corporation, #1500S) and 0.17 g of pullulanase (Hayashibara Biochemical Laboratories, No. 31001) were dissolved in the 0.8 M acetic acid-Na acetate buffer to make 100 mL. 5) Inactivated enzyme solution: Prepared by boiling the enzyme solution for 10 minutes. 6) Somogyi and Nelson reagents (reagents for measuring reducing sugars)

[0034] (B)Measurement method B-1) The sample (gelatinized flour) is pulverized with a homogenizer to a mesh size of 100 or less. 0.08 to 0.10 g of this pulverized sample flour is placed in a glass homogenizer. B-2) 8.0 mL of demineralized water is added to the contents of the glass homogenizer, and the glass homogenizer is moved up and down 10 to 20 times to disperse the contents, thereby obtaining a dispersion. B-3) Place 2 mL of the dispersion liquid from B-2) into each of two 25 mL graduated test tubes, and dilute one of the tubes to volume with 0.8 M acetic acid-Na acetate buffer to use as the test group. B-4) Add 0.2 mL of 10N sodium hydroxide solution to the other of the two tubes, and react at 50°C for 3 to 5 minutes to completely gelatinize the dispersion of B-2). After that, add 1.0 mL of 2N acetic acid solution to the other tube to adjust the pH to around 6.0, and then make the volume constant with 0.8M acetic acid-Na acetate buffer to make the gelatinized section. B-5) Take 0.4 mL of each of the test liquids prepared in B-3) and B-4) above for the test and gelatinized sections, add 0.1 mL of enzyme solution to each, and perform the enzyme reaction at 40°C for 30 minutes to obtain a reacted liquid. At the same time, prepare a blank by adding 0.1 mL of inactivated enzyme solution instead of the enzyme solution. The enzyme reaction is performed while occasionally stirring the reaction liquid during the reaction. B-6) Add 0.5 mL of Somogyi's reagent to 0.5 mL of the reaction solution and the blank, and boil in a boiling bath for 15 minutes. After boiling, cool in running water for 5 minutes, add 1.0 mL of Nelson's reagent, stir, and leave for 15 minutes. B-7) Then, add 8.00 mL of demineralized water to each of the reacted liquid and the blank, stir, and measure the absorbance at 500 nm.

[0035] (C) Calculation of degree of gelatinization The degree of gelatinization is calculated according to the following formula. Degree of gelatinization (%) = {(decomposition rate of test liquid) / (decomposition rate of fully gelatinized test liquid)} x 100 ={(Aa) / (A'-a')}×100 In the above formula, A, A', a, and a' are as follows. A = absorbance of the test area A' = absorbance of gelatinized area a = blank absorbance of the test area a' = blank absorbance of gelatinized area

[0036] The gelatinized flours produced by the production method of the present invention (hereinafter also referred to as "specific gelatinized flours") can be used in place of known gelatinized flours and gelatinized starches, and can typically be used in the production of processed foods in the food industry. The processed foods referred to here are those produced using grain flours as raw materials, and examples thereof include noodles such as udon, somen, hiyamugi, Chinese noodles, pasta, and instant noodles (including non-fried noodles); bakery foods; fried foods such as tempura, fried chicken, tatsuta-age, and fritters; and powdered foods such as instant soups. The processed foods may be frozen foods. The gelatinized flours obtained by the production method of the present invention are particularly suitable for noodles, and can provide noodles with excellent viscoelasticity and good taste and texture, and can also be imparted with aging resistance. The production of processed foods can be carried out according to conventional methods depending on the type of processed food.

[0037] The method for producing noodles using the gelatinized flour produced by the production method of the present invention (hereinafter also referred to as the "method for producing noodles of the present invention") will be described below. The method for producing noodles of the present invention includes a step of preparing noodle dough using specific gelatinized grain flours (noodle dough preparation step). The noodle dough can be prepared according to a conventional method. Typically, the noodle dough is prepared by adding a liquid ingredient to raw material flour containing specific gelatinized grain flours and kneading using a mixer or the like. The "raw material flour" referred to here refers to a powdered ingredient at room temperature and normal pressure, and typically includes grain flours (including specific gelatinized grain flours) and vegetable proteins such as wheat protein, but does not include auxiliary ingredients such as salt, sugar, oils and fats. The liquid ingredient is typically mainly composed of water, but may further contain other water-soluble ingredients such as salt, eggs, etc. in addition to water. The amount of the liquid ingredient added to the raw material flour is not particularly limited and may be appropriately adjusted depending on the type of noodles to be produced, etc.

[0038] The raw material flour used in the noodle dough preparation step contains at least cereal flours, and the content of specific gelatinized cereal flours in the cereal flours is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 2 to 20% by mass, relative to the total mass of the cereal flours. This makes it possible to obtain noodles that have excellent viscoelasticity, good taste and texture, and excellent resistance to deterioration over time. If the content is less than 0.5% by mass, there is little point in using specific gelatinized cereal flours, and if the content exceeds 40% by mass, there is a risk that it will have an adverse effect on secondary processability and the quality of the noodles.

[0039] The raw material flour used in the noodle dough preparation step typically contains, in addition to specific pregelatinized grain flours, other grain flours other than the specific pregelatinized grain flours. The type and content of the other grain flours other than the specific pregelatinized grain flours are not particularly limited and can be selected as appropriate depending on the type of noodles to be produced. As the other grain flours other than the specific pregelatinized grain flours, one or more types can be selected from the specific examples of raw material grain flours used in the slurry preparation step. As mentioned above, it is preferable to use grain flours other than bran as such raw material grain flours, but there are no such limitations on the raw material flour used in the noodle dough preparation step, and bran may be used.

[0040] The raw material flour used in the noodle dough preparation step may contain other ingredients besides cereal flours. The other ingredients can be any ingredient that can be used in the production of noodles, without any particular restrictions, and examples of such ingredients include protein materials such as gluten, soy protein, soy polysaccharides, egg yolk powder, egg white powder, whole egg powder, egg protein enzymatic hydrolysates, and skim milk powder; oils and fats such as animal and vegetable oils and fats and powdered oils and fats; thickeners such as thickening polysaccharides; kansui, calcined calcium, dietary fiber other than resistant starch, leavening agents, salt, sweeteners, spices, seasonings, vitamins, minerals, colorants, flavorings, dextrin, alcohol, preservatives, pH adjusters, enzymes, malt, and the like. These can be used alone or in combination of two or more depending on the type of noodles to be produced.

[0041] The method for producing noodles of the present invention typically comprises, after the noodle dough preparation step, a step of shaping the noodle dough into a predetermined shape such as a noodle string shape (shaping step). The shaping step can be carried out according to a conventional method, and can be selected from known noodle-making methods such as mechanical methods, hand-stretching methods, hand-made methods, and extrusion methods depending on the type of noodles to be produced, the shape of the noodles, and the like. One example of a method for forming noodle dough that can be used in the method for producing noodles of the present invention is a method in which pressure is applied to the noodle dough to stretch it to obtain a noodle band by various noodle-making methods such as rolling and roll-making, and then the noodle band is cut out to obtain noodle strands. Another example of a method for forming noodle dough that can be used in the method for producing noodles of the present invention is a method in which pressure is applied to the noodle dough to produce extrusion noodles. Extrusion noodle making can be carried out in the usual manner using a single-screw extrusion noodle making machine or a twin-screw extrusion noodle making machine used for producing pasta, and in this case, a die with holes of the desired shape is placed in the noodle strand extrusion section of the extrusion noodle making machine, and noodle strands of a shape corresponding to the holes are obtained by extruding the noodle strands. There are no particular limitations on the cross-sectional shape of the noodle strands, and they may be any shape such as circular, rectangular, elliptical, or triangular.

[0042] When the object of production is dried noodles, the method for producing noodles of the present invention comprises a step of drying the shaped dough (raw noodles) after the above-mentioned shaping step. Alternatively, when the object of production is instant noodles, the method comprises a step of cooking the raw noodles with heat and then drying the cooked noodles. There are no particular limitations on the method for drying the raw noodles or cooked noodles, and it may be a non-oil-added drying method in which the noodles are dried without being added with oil, such as natural drying, temperature and humidity controlled drying, or hot air drying, or an oil-added drying method in which the noodles are dried with being added with oil, and can be selected appropriately depending on the type of object of production, etc.

[0043] The noodles to which the present invention can be applied are not particularly limited, and examples thereof include noodle strings such as udon, somen, hiyamugi, Chinese noodles, and pasta (including short pasta, long pasta, flat pasta, etc.); and noodle skins such as gyoza, shumai, and wonton. The present invention is particularly useful for udon among noodle strings, and for gyoza among noodle skins. The present invention is also applicable to raw noodles, cooked noodles (boiled noodles, steamed noodles, etc.), raw or cooked frozen noodles, refrigerated or chilled noodles, non-fried instant noodles, fried instant noodles, dried noodles, etc.

[0044] Other examples of uses for pregelatinized flours in the food industry include: 1) thickening and shape retention for applications that eliminate the need for thermal cooking (such as instant soups), 2) modifying the dough of cake mixes and stabilizing the structure of frozen foods, 3) in the case of pregelatinized flours produced using cornstarch as the flour, as a substitute for soup or rice flour, and 4) in the case of pregelatinized flours produced using waxy cornstarch as the flour, as a coating for bean confectioneries.

[0045] Furthermore, the gelatinized cereal flour produced by the production method of the present invention can also be used in fields other than the food industry. Examples of uses of gelatinized cereal flour produced using potato starch as the cereal flour include caking of feed, caking of foundry sand molds, incense sticks, grinding stones, etc., household laundry glue, paper strength enhancer, etc. EXAMPLES

[0046] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0047] [Examples 1 to 9, Comparative Examples 1 to 3] Processed tapioca starch was used as the raw flour, and polysaccharides and water were added to the raw flour in the proportions shown in Tables 1 and 2 to prepare an aqueous slurry (slurry preparation step). This slurry was placed in a pressure vessel equipped with an agitator (a rotatably installed paddle) and heated at 120°C (the product temperature of the slurry) for 20 minutes (the product temperature was maintained) while being stirred with the agitator (slurry heating step). Next, the slurry (gelatinized liquid) that had undergone the slurry heating step was freeze-dried using a commercially available freeze dryer (product name "Genesis SQ", manufactured by SP Industries) to obtain a solid (slurry drying step). Next, the obtained solid was pulverized using a commercially available coffee mill to produce pregelatinized flour (more specifically, pregelatinized starch). Details of the raw materials used in the production of the pregelatinized flour are as follows.

[0048] Processed tapioca starch (etherified phosphate cross-linked tapioca starch): "Yuri 8" manufactured by Matsutani Chemical Industry Co., Ltd. Xanthan gum: "SATIAXANE CX 90" manufactured by Cargill France SAS Guar gum: HABGEN GUARGUMS "PROCO S-1" Mannan: "Ultramannan G5" manufactured by Ina Food Industry Co., Ltd. Propylene glycol alginate (hereinafter referred to as "PG alginate"): "Neosoft AL-31" manufactured by Taiyo Kagaku Co., Ltd.

[0049] [Table 1]

[0050] [Test Example 1] Noodle dough was prepared using the gelatinized flour produced above. Specifically, raw material flour A was prepared by adding 5 parts by mass of wheat protein ("A-Glu G" manufactured by Glico Nutrition Foods Co., Ltd.) to 100 parts by mass of grain flour containing 5% by mass of the test object (gelatinized grain flour of the Example or Comparative Example, or the mixture of gelatinized grain flour and polysaccharide of Comparative Example 1) shown in Tables 2 and 3, 70% by mass of medium strength flour ("Houn" manufactured by Nisshin Flour Milling Co., Ltd.) and 25% by mass of etherified phosphate cross-linked tapioca starch ("Morning G" manufactured by Matsutani Chemical Industry Co., Ltd.). An appropriate amount of water in which 3 parts by mass of salt had been dissolved was added to 100 parts by mass of raw material flour A, and the mixture was kneaded under a reduced pressure of -90 kPa to prepare a noodle dough. The noodle dough was then rolled and cut into noodle strands 3 mm thick using a cutting blade (#10 square). The noodle strands were then boiled in boiling water, washed with water, and cooled to produce boiled udon, a type of cooked noodle.

[0051] The boiled udon noodles were eaten by 10 expert panelists immediately after production, and the texture (viscoelasticity) was rated according to the following evaluation criteria. In addition, a part of the boiled udon was used to produce cold boiled udon, and the texture (viscoelasticity) of the cold boiled udon was evaluated in the same manner as for the boiled udon. Specifically, 3 parts by mass of a loosening agent ("SOYAUP M3000" manufactured by Fuji Oil Co., Ltd.) was uniformly applied to 100 parts by mass of the boiled udon by spraying, and then the udon was cooled in a refrigerator at an internal temperature of 4°C to produce cold boiled udon, which was then stored in the refrigerator for 3 days. The udon was then taken out of the refrigerator and eaten as is by a panel of experts, who evaluated the texture (viscoelasticity) according to the following evaluation criteria.

[0052] The "control example" in the evaluation criteria below is boiled udon noodles produced in the same manner as described above, using processed tapioca starch "Yuri 8" (manufactured by Matsutani Chemical Industry Co., Ltd.; the same as the raw grain flour used in the examples and comparative examples) as the test object. The scoring results (arithmetic mean of scores from 10 expert panelists) are shown in Tables 2 and 3. In Tables 2 and 3, the test examples that used pregelatinized grain flour of the Examples as the test object are compared to the test example to the left of the relevant test example (which used a mixture of pregelatinized grain flour and polysaccharides of the Comparative Example as the test object). For example, the comparison object of Test Example 1-3 is Test Example 1-2, and the comparison object of Test Example 1-5 is 1-4. In Tables 2 and 3, "immediately after production" refers to boiled udon, and "after refrigerated storage" refers to cold boiled udon.

[0053] <Evaluation criteria for texture (viscoelasticity)> 5 points: The viscoelasticity is much better than that of the control example. 4 points: Superior viscoelasticity compared to the control example. 3 points: Slightly better viscoelasticity than the control example. 2 points: equivalent to the control. 1 point: Viscoelasticity is inferior to the control.

[0054] [Table 2]

[0055] [Table 3]

Claims

1. A slurry heating step of heating a slurry containing 100 parts by mass of raw material flour, 0.1 to 3 parts by mass of polysaccharides, and 500 parts by mass or more of water under conditions such that the product temperature of the slurry is 90 ° C. or higher; and a step of drying the slurry that has been subjected to the slurry heating step to obtain a solid product. A method for producing gelatinized flour, wherein the slurry is stirred during heating in the slurry heating step.

2. 2. The method for producing gelatinized grain flour according to claim 1, wherein the polysaccharide is at least one selected from the group consisting of xanthan gum, guar gum, mannan, and propylene glycol alginate.

3. The method for producing gelatinized grain flour according to claim 1 , wherein the raw grain flour contains starch.

4. The method for producing gelatinized grain flour according to claim 1, wherein in the slurry heating step, the slurry is heated under conditions such that the product temperature is 100°C or higher.

5. The method for producing gelatinized grain flour according to claim 1, wherein in the slurry heating step, the slurry is heated under conditions such that the product temperature is 110 to 140°C.

6. 2. The method for producing gelatinized grain flour according to claim 1, wherein the slurry is heated in a pressurized atmosphere in the slurry heating step.

7. A method for producing processed foods, which uses gelatinized grain flour produced by the method according to any one of claims 1 to 6.

8. The method for producing a processed food according to claim 7, wherein the processed food is noodles.