Method for producing heat-treated cereal flour

Abstract

The present invention relates to a method for producing a heat-treated cereal powder, the method comprising a step for producing a heat-treated cereal powder by mixing water in a cereal powder using an extruder having a cooling die attached to an outlet of an object to be heat-treated in the extruder. In the cooling die, preferably, the opening area of an outlet opening part which opens towards the extrusion direction of the extruder is more than 20 mm2, and the overall length of the cooling die in the extrusion direction of the extruder is more than 60 mm. Preferably, the extruder is a double-screw extruder.

Description

Technical Field

[0001] This invention relates to a method for manufacturing heat-treated cereal flours, heat-treated cereal flours, foods using heat-treated cereal flours, and a method for improving the aging resistance of foods using heat-treated cereal flours. Background Technology

[0002] Patent Document 1 describes a method for manufacturing a mixture for baking products or for leather products, in which only 40-45% by weight of water is added to the raw wheat flour, and a single-screw extruder is used to perform a hydrothermal treatment based on pressure heating to obtain hydrothermally treated wheat flour with an α degree of 85% or more and a viscosity of 500 B.U. or less. The hydrothermally treated wheat flour is added at 1-30% by weight relative to the wheat flour used in the mixture.

[0003] Patent document 2 describes a method for manufacturing meat sample food using a cooling mold.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2003-061600 Patent Document 2: US 2019 / 0364925 A1 Summary of the Invention

[0005] However, the prior art described in Patent Document 1 is not sufficient in manufacturing heat-treated cereal flours that can impart good taste to food and resistance to deterioration over time.

[0006] In addition, Patent Document 2 relates to meat-based food products, but it does not conduct any research on the effects of heat-treated cereal flour products on improving the texture of the food and its resistance to degradation over time.

[0007] The inventors have conducted in-depth research on a method for manufacturing novel cereal flour raw materials that, when using an extruder, impart excellent taste and resistance to taste deterioration over time. The results show that by installing a cooling die on an extruder, heat-treated cereal flours that impart good taste to food and exhibit good resistance to taste deterioration over time can be obtained.

[0008] Based on the above insights, the present invention provides a method for manufacturing heat-treated cereal flour, comprising the steps of mixing water in cereal flour using an extruder and heating and pressurizing it to manufacture heat-treated cereal flour, wherein a cooling die is installed at the outlet of the extruder.

[0009] In addition, the present invention provides heat-treated cereal flour manufactured by the above-described manufacturing method, food products using the heat-treated cereal flour, food compositions, and a method for improving the aging resistance of food. Detailed Implementation

[0010] The present invention will now be described based on its preferred embodiments. The upper and lower limits described in this specification may be combined in any way without particular limitation. Furthermore, in this specification, "texture" includes a moist texture.

[0011] The inventors have discovered the following problems when adding water during the heating and pressurizing process of an extruder to obtain heat-treated cereal flours. To form heat-treated cereal flours that produce food with good texture and excellent resistance to degradation over time, it is preferable to add a large amount of water during heat treatment using an extruder. However, it is known that if a large amount of water is added during heating and pressurizing using an extruder, the viscosity of the cereal flour dispersion (a mixture of water and cereal flour) at the extruder outlet decreases, and the pressure inside the extruder decreases.

[0012] In addition, it is known that if a large amount of water is added when heating and pressurizing the extruder, the viscosity of the mixture of water and grain powder will decrease, and the grain powder dispersion will spray out from the extruder outlet, making it impossible to stably produce heat-treated grain powder.

[0013] Therefore, the inventors installed a cooling die at the outlet of the extruder to increase the pressure inside the extruder. As a result, cereal flour can be stably discharged from the outlet of the extruder, successfully producing heat-treated cereal flour that ensures manufacturing stability, imparts excellent taste to food, and exhibits resistance to taste deterioration over time. Furthermore, the inventors discovered that even with a relatively low water content (e.g., less than 46% by mass relative to the cereal flour), installing the cooling die can further improve excellent taste and aging resistance.

[0014] As described above, the present invention increases the pressure inside the extruder by installing a cooling die at the extruder outlet. This facilitates the opening of the side chains of starch in cereal flours, resulting in excellent mouthfeel while maintaining manufacturing stability and improving resistance to mouthfeel degradation over time.

[0015] In this specification, a cooling die refers to a die that functions as a heat exchanger capable of removing at least a portion of the heat from the contents passing through it. The function of this heat exchanger does not necessarily manifest as a temperature difference between the heat-treated material ejected from the cooling die and the internal temperature of the extruder. Cooling dies are typically tubular or cylindrical, and by removing heat from the outer layer of the contents through the wall of the tube, the viscosity of the outer layer can be increased, thereby increasing the pressure inside the extruder. Furthermore, when "cylindrical" is mentioned in this specification, it refers to a cylindrical or square shape with internal cavities forming flow paths.

[0016] In addition, cooling dies typically have a certain length and a certain opening area relative to the extruder barrel. By installing a die with this shape at the extruder outlet, the pressure inside the extruder can be increased.

[0017] The extruder disclosed herein typically comprises: a hollow cylindrical barrel (also called a feed barrel) containing a raw material composition (in this disclosure, a mixture of grain flours (e.g., a mixture containing grain flours and water)), a screw disposed inside the barrel and driven to rotate by a drive source such as a motor, a feeder for supplying the raw material composition into the barrel, and the aforementioned cooling die installed at the outlet of the barrel. The raw material composition fed into the barrel via the feeder is compressed by the screw and moves toward the die, and is extruded from the die.

[0018] It should be noted that sometimes heating mechanisms such as tubular heaters are attached around the barrel to heat the raw material composition inside the barrel.

[0019] The extruder used in this invention can be either a single-screw extruder or a twin-screw extruder, preferably a twin-screw extruder. A twin-screw extruder is preferred. In a twin-screw extruder, the two screws are arranged parallel to each other. When the extruder used in this invention is a twin-screw extruder, the use of two screws results in high mixing power and excellent processing capacity, as well as high propulsion force. Therefore, it is preferred from the viewpoint of easily increasing the pressure on the heat-treated material (cereal mixture) near the barrel outlet.

[0020] A cooling die is installed at the outlet end (outlet end of the barrel) of the extruder for heat-treated material. The cooling die is hermetically connected to the extruder barrel, and their interiors are in communication. The cooling die has an inlet opening facing in the opposite direction to the extrusion direction of the extruder, an outlet opening facing the extrusion direction of the extruder, and a flow path for the heat-treated material connecting the two openings. In the flow path, the heat-treated material flows along the extrusion direction of the extruder. The heat-treated material that has passed through the outlet of the extruder barrel is introduced into the flow path through the inlet opening of the cooling die and extruded from the outlet opening to the outside of the cooling die.

[0021] From the viewpoint of reducing the flowability of the contents, the length of the cooling die in the extrusion direction (hereinafter also referred to as "total length L" or "total length of the cooling die") is preferably 60 mm or more. With such a length, the effect of increasing the internal extruder pressure due to the use of the cooling die is enhanced, resulting in improved mouthfeel, improved resistance to mouthfeel deterioration over time, and superior manufacturing stability. From this perspective, the length of the cooling die in the extrusion direction is preferably 100 mm or more, more preferably 200 mm or more. Furthermore, from the viewpoint of ensuring stable discharge of heat-treated cereal flour, the length of the cooling die in the extrusion direction is preferably 1200 mm or less.

[0022] The opening area of ​​the outlet opening of the aforementioned cooling die head (hereinafter also referred to as "the opening area of ​​the cooling die head" or "area S2") is 20 mm. 2 In the above aspects, the manufacturing stability of heat-treated grain flour, the resistance to clogging at the outlet, and the stable discharge of contents are preferred. Furthermore, the manufacturing stability of ensuring stable discharge of heat-treated grain flour from the cooling die head without clogging is also preferred. From this perspective, the opening area of ​​the outlet opening of the cooling die head is more preferably 23 mm. 2 The above is particularly preferred, with 25mm being the most suitable. 2 The opening area of ​​the cooling die head's outlet is 550 mm². 2 In the following cases, by sufficiently increasing the pressure on the heat-treated material (cereal flour mixture) in the barrel and cooling die of the extruder, the aforementioned effects of improving mouthfeel and improving mouthfeel durability over time are highly effective; therefore, 350 mm is preferred, and more preferably preferred. 2 The following is particularly preferred: 280mm 2 the following.

[0023] In addition, the ratio of the area of ​​the cooling die's outlet opening to the screw diameter of the twin-screw extruder (die opening area in mm) 2 When the ratio (screw diameter of the extruder in mm) is below a specified value, increasing the internal pressure of the extruder makes it easier to open the side chains of starch in cereal flours, which can further improve the taste and its resistance to deterioration over time, and is therefore preferred. From this perspective, the above ratio (unit: die opening area in mm) is... 2 The screw diameter of the extruder (in mm) is preferably 11.8 or less, more preferably 8.0 or less, and even more preferably 6.0 or less.

[0024] Furthermore, from the viewpoint of the manufacturing stability of the heat-treated material that has been stably extruded and thickened, the aforementioned ratio (unit: mm : (die opening area mm)) 2The screw diameter of the extruder (in mm) is preferably 0.11 or more, more preferably 0.3 or more, and particularly preferably 0.5 or more.

[0025] The area of ​​the outlet opening of the cooling die is the area when viewed from the opposite side of the extrusion direction of the extruder. In the case of multiple outlet openings of the cooling die that are connected to the outlet of the extruder, it is the sum of the areas of the multiple openings.

[0026] Furthermore, the screw diameter of the extruder is the diameter when the projected image of the screw viewed from its axial direction is circular; otherwise, it is the length of the longest line segment that crosses the projected image. In a twin-screw extruder, if the two screws have different diameters, the diameter of the larger screw is used.

[0027] The cross-sectional shape of the cooling die along the extrusion direction of the extruder is not particularly limited. Furthermore, the area of ​​the cross-section of the cooling die orthogonal to the extrusion direction along the extrusion direction may or may not be constant. For example, the ratio (S1:S2) of the maximum area (maximum area of ​​the flow path) S1 of the cross-section orthogonal to the extrusion direction of the heat-treated material, formed by the interior of the extruder barrel and the cooling die, to the area S2 of the outlet opening of the cooling die is preferably in the range of 1:0.01 to 1.80. The maximum area of ​​the flow path is the maximum value along the entire length of the flow path in the extrusion direction of the extruder; in the case where the flow path is divided into multiple sections in the aforementioned cross-section, it is the sum of the areas of the multiple flow paths.

[0028] The cooling head used in this invention functions as a heat exchanger. One example of a heat exchanger is a partitioned heat exchanger. For instance, a double-tube structure can be described, having an outer tube and an inner tube disposed inside the outer tube and functioning as a flow path for the contents of the cooling head. A refrigerant is disposed between the outer tube and the inner tube, and the contents of the inner tube are cooled through heat exchange with the refrigerant. Preferably, the refrigerant is a fluid (liquid or gas) that flows through the flow path between the outer tube and the inner tube.

[0029] In addition to indirect contact heat exchangers, other examples of heat exchangers include direct contact heat exchangers. For example, a heat exchanger that cools the contents by allowing cold air to flow into the interior of a cooling head.

[0030] There are no particular limitations on the cooling method used for heat-treated objects using a cooling die; it can be either forced cooling or natural cooling. Forced cooling uses one or more refrigerants selected from liquids and gases, employing a drive source that uses the refrigerant as a fluid to cool the object. Natural cooling does not use the aforementioned refrigerant or drive source; it simply involves guiding the object through the flow path of the cooling die to release heat.

[0031] For example, in a double-tube structure, even without refrigerant flow (natural cooling), the ambient air exchanges heat with the workpiece in the same way as the refrigerant. Specifically, heat exchange occurs between the air existing between the double-tube structure and the contents of the inner tube, and heat is removed from the contents of the inner tube. This allows heat to be removed from the workpiece, resulting in a certain increase in pressure on the workpiece. In Examples 22, 24-27 described later, even without refrigerant flow in the double-tube structure, the heated workpiece can be cooled and its temperature reduced. Furthermore, Examples 13-15 described later show that even without refrigerant flow in the double-tube structure, the pressure inside the extruder can be sufficiently increased.

[0032] On the other hand, when circulating the refrigerant, considering the superior effects of improving taste and resistance to deterioration over time brought about by using the aforementioned cooling die, the refrigerant temperature at the position (hereinafter referred to as "position E1") closest to the outlet (hereinafter also referred to as "outlet Ex") of the heat-treated material in the refrigerant circulation section of the cooling die, according to the function of the heat exchanger, is preferably 50°C or less, more preferably 40°C or less, and particularly preferably 35°C or less. Furthermore, considering the ease of preventing blockages at the outlet of the extruder and ensuring stable discharge of the contents, the refrigerant temperature at position E1 in the refrigerant circulation section of the cooling die is preferably 5°C or more. It should be noted that when there are multiple separate refrigerant circulation sections in the cooling die, position E1 refers to the position closest to outlet Ex in the extruder extrusion direction among all the refrigerant circulation sections. It should also be noted that when outlet Ex has a certain length in the extruder extrusion direction, position E1 refers to the position closest to the end opposite to outlet Ex on the extruder side.

[0033] In this specification, the refrigerant temperature at position E1 will be referred to as the "exit-side cooling temperature of the cooling die".

[0034] Furthermore, considering the superior effects of using the aforementioned cooling die on improving taste and resistance to deterioration over time, the refrigerant temperature at the position (hereinafter referred to as "position E2") closest to the inlet (hereinafter also referred to as "inlet In") of the heat-treated material in the refrigerant flow section of the cooling die, according to the function of the heat exchanger, is preferably 40°C or less, more preferably 35°C or less, and particularly preferably 30°C or less. Additionally, from the viewpoint of minimizing blockage at the extruder outlet and ensuring stable discharge of the contents, the refrigerant temperature at position E2 in the refrigerant flow section of the cooling die is preferably 10°C or more. It should be noted that when there are multiple separate refrigerant flow sections in the cooling die, position E2 refers to the position closest to inlet In in the extruder extrusion direction among all the refrigerant flow sections. Furthermore, when inlet In has a certain length in the extruder extrusion direction, position E2 refers to the position closest to the extruder-side end of inlet In.

[0035] In this specification, the refrigerant temperature at position E2 will be referred to as the "inlet-side cooling temperature of the cooling die".

[0036] In the extrusion direction of the cooling die head in the extrusion press, the ratio (Lx / L) of the length Lx of the refrigerant flow portion in the same direction of the cooling die head to the total length L of the cooling die head in the same direction is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more. When there are multiple refrigerant flow portions separated in the same direction, the aforementioned length Lx is their total length.

[0037] From the perspective of superior cooling performance, the cooling die head preferably has a double-tube structure as a heat exchanger, with refrigerant disposed between the outer tube and the inner tube, and the contents are cooled through heat exchange with the refrigerant. The refrigerant preferably flows at least on the inlet side of the extrusion direction of the cooling die head, but it can also flow substantially throughout the entire extrusion direction of the cooling die head.

[0038] From the perspective of heat exchange efficiency, it is preferable that the refrigerant flows in the cooling die in the opposite direction to the extrusion direction of the extruder.

[0039] The inner tube of the cooling die head with a dual-tube structure is preferably made of metal, and more preferably stainless steel. SUS304 stainless steel is used as the material for the inner tube of the cooling die head in the embodiments described later.

[0040] The refrigerant flow rate is preferably 0.01 to 1 m / s, more preferably 0.01 to 0.1 m / s. In the embodiments described later, in which the refrigerant flows through the cooling die head, the refrigerant flow rate is in the range of 0.01 to 0.1 m / s.

[0041] From the viewpoint of reliably achieving the intended effects of the present invention, the pressure applied by the extruder is preferably 0.2 MPa or more, more preferably 0.2 to 10 MPa, even more preferably 0.2 to 9 MPa, and particularly preferably 0.3 to 9 MPa. By setting the above-mentioned pressure below a certain level, the ejection from the extruder is more stable, and it is easier to prevent a decrease in productivity, therefore this is preferred.

[0042] The “pressure” refers to the pressure at the barrel outlet of the extruder.

[0043] From the same point of view, the heating temperature of the extruder is preferably above 80°C, more preferably 80~200°C, even more preferably 80~180°C, and particularly preferably 80~165°C. Setting the above heating temperature below a certain level makes the ejection from the extruder more stable and makes it easier to prevent a decrease in productivity, and is therefore preferred.

[0044] The "heating temperature" refers to the barrel heating temperature of the extruder.

[0045] From the viewpoint of further reliably achieving the intended effects of the present invention, in the pressurized heating treatment of a cereal flour mixture using an extruder, the time (processing time) for maintaining the aforementioned pressure and heating temperature is preferably 5 seconds or more. Furthermore, from the same viewpoint, the upper limit of the time (processing time) for maintaining the aforementioned pressure and heating temperature is preferably 90 seconds or less, more preferably 60 seconds or less.

[0046] From the viewpoint of further reliably improving manufacturing stability and taste, the temperature of the heat-treated material at the outlet of the cooling die head is preferably below 180°C, more preferably below 160°C. There is no limitation on the lower limit of the temperature of the heat-treated material at the outlet of the cooling die head; for example, it can be above 80°C, above 100°C, above 115°C, or above 120°C.

[0047] By using an extruder to add water to cereal flour and then heating and pressurizing it, the side chains of starch are opened, resulting in improved texture and resistance to long-term degradation of the food. To enhance this effect, the amount of water added relative to 100 parts by weight of cereal flour is preferably 40 parts by weight or more, more preferably 42 parts by weight or more, and particularly preferably 46 parts by weight or more.

[0048] Furthermore, from the viewpoint of manufacturing stability, when using the extruder for pressurized heating, the amount of water added to the grain flour is more preferably 80 parts by weight or less, and more preferably 70 parts by weight or less, relative to 100 parts by weight of the grain flour. Here, the amount of water added is the total amount of moisture used from the raw grain flour to the heat-treated grain flour, and can be based on saturated steam or water. Alternatively, water can be added to the grain flour in advance during a pre-conditioning process before the extrusion process.

[0049] The raw material composition containing cereal flour and moisture is pressurized and heated using an extruder and extruded from a cooling die to obtain the target heat-treated cereal flour.

[0050] In the manufacturing method of this invention, it is preferable to pulverize the heat-treated grain flour obtained by pressurizing and heating an extruder. This pulverization process can be performed using a household grinder such as a coffee grinder or juicer, or an industrial grinder such as a hammer mill, pin mill, or jet mill, following conventional methods, pulverizing the solid material to the desired particle size. Alternatively, the heat-treated grain flour extruded by pressurizing and heating can be dried before pulverization. Drying is a process to reduce the moisture content of the heat-treated grain flour, and can be performed using known drying methods such as air drying or hot air drying.

[0051] For example, the average particle size of heat-treated grain flour is preferably 0.4 to 700.0 μm. The average particle size of the heat-treated grain flour in the embodiments described later is within the above range. It should be noted that, in this specification, "average particle size" refers to the volumetric cumulative particle size D50 at 50% of the cumulative volume when measured dry using a laser diffraction scattering particle size distribution measuring device (e.g., Microtrac S3500 manufactured by Microtrac BEL Co., Ltd.).

[0052] (Raw materials: cereal flour) In this instruction manual, "cereal flour" refers to both starch and cereal flour with starch as its main component, which are powdery or granular substances at room temperature and pressure. The "starch" used here refers to "pure starch" isolated from plants such as wheat, distinct from the starch inherent in cereal flour or whole grain flour. It should be noted that when "starch" is used in this instruction manual, the context should be considered to determine whether it refers to pure starch or the starch inherent in cereal flour or whole grain flour.

[0053] The grains mentioned above that serve as sources of "cereals" include cereals (seeds of grasses), pseudo-grasses (seeds of dicotyledons), legumes (seeds of legumes), and tubers (roots or tubers that are eaten), all of which contain starch as a component.

[0054] Specific examples of cereal flours include wheat flour (specifically, such as strong flour, medium flour, light flour, durum wheat flour, and durum semolina), rice flour, buckwheat flour, rye flour, soybean flour, barley flour, and corn flour, which are primarily composed of the endosperm. Other cereal flours that include at least the bran and germ can also be cited, such as "whole grain flour," which comprises the three main components of the bran and germ. A specific example of whole grain flour is whole wheat flour.

[0055] Specific examples of starch include potato starch, wheat starch, corn starch, waxy corn starch, rice starch, and tapioca starch.

[0056] The starch may be chemically modified starch. Chemical modification is the treatment of starch by introducing modifying groups through chemical agents. Examples of chemically modified starch include acetylated adipic acid cross-linked starch, acetylated phosphoric acid cross-linked starch, acetylated oxidized starch, sodium octenyl succinate starch, acetic acid starch, oxidized starch, hydroxypropyl starch, hydroxypropylated phosphoric acid cross-linked starch, phosphorylated monoesterified phosphoric acid cross-linked starch, phosphorylated starch, and phosphoric acid cross-linked starch.

[0057] When wheat flour is used as the cereal flour in this invention, the resulting heat-treated cereal flour exhibits excellent taste and resistance to degradation over time when used in food. Therefore, low amylose wheat flour is preferred, and particularly preferred. Here, low amylose wheat flour refers to wheat flour derived from wheat lacking one or more genes selected from the Wx-A1, Wx-B1, and Wx-D1 genes. This includes wheat flour derived from wheat lacking the Wx-A1, Wx-B1, or Wx-D1 genes (Haruyokoi, Sachikaori, Setokirara, Kitahonami, etc.); wheat flour derived from wheat lacking two genes selected from the Wx-A1, Wx-B1, and Wx-D1 genes (Ayahikari, Chikugoizumi, Tsurupikari, etc.); and wheat flour derived from wheat lacking all three genes (Mochihime, Urararamoch, etc.).

[0058] (Heat-treated cereal flour products) The heat-treated cereal flours (hereinafter also referred to as "specific heat-treated cereal flours") manufactured by the method of the present invention can be used in place of known α-based cereal flours and α-based starches, and are typically used in the food industry for the manufacture of processed foods. Processed foods, as described herein, are manufactured using cereal flours as raw materials, and examples include noodles such as udon noodles, dried noodles, cold noodles, Chinese noodles, pasta, and instant udon noodles (including non-fried noodles); baked goods; fried foods such as tempura, fried chicken nuggets, tatsuta fritters, and fried pies; and powdered foods such as instant soups. Processed foods can also be frozen foods. The heat-treated cereal flours obtained by the method of the present invention are particularly suitable for baked goods, producing baked goods with good texture and imparting resistance to aging. The manufacture of processed foods can be carried out according to conventional methods depending on the type of processed food.

[0059] Next, a food composition containing the heat-treated cereal flour of the present invention will be described. Examples of the food composition of the present invention include cereal flours containing the heat-treated cereal flour of the present invention, preferably containing both heat-treated and untreated cereal flours, and particularly preferably containing both heat-treated and untreated cereal flours. As untreated cereal flours that can be used in conjunction with the heat-treated cereal flour of the present invention, unprocessed cereal flours (unprocessed cereal flour, unprocessed starch) that have not undergone any heat treatment or other processing can be used, or processed cereal flours that have undergone one or more processing treatments other than heat treatment (e.g., etherification, esterification, acetylation, cross-linking treatment, oxidation treatment, oil processing, etc.) can be used. Specific examples of unprocessed cereal flours are described above.

[0060] In the above-mentioned food composition, one type of cereal flour other than the heat-treated cereal flour of the present invention may be used alone, or two or more types may be used in combination.

[0061] The proportion of heat-treated cereal flour in the above-mentioned food composition is preferably 0.1 to 20% by mass, more preferably 5 to 10% by mass. Examples of such compositions include dough mixtures. Examples of components used in the dough mixtures, i.e., the compositions of the present invention, include, for example, leavening agents or yeast such as sodium bicarbonate (baking soda), baking powder, ammonium carbonate, ammonium bicarbonate, and ammonium chloride; oils such as salad oil; sugars such as sugar; eggs such as whole eggs, egg whites, and egg yolks; dairy products such as milk, skim milk powder, and butter; salts such as salt; and additives such as emulsifiers, thickeners, acidulants, flavorings, spices, colorings, fruit juices, and vitamins. One or more of these can be used alone or in combination.

[0062] The heat-treated cereal flour and food composition of the present invention can be used in the manufacture of dough-heated foods. In this invention, "dough-heated foods" refers to foods made by mixing cereal flour and / or starch with other ingredients to prepare an unheated dough, and then heating the dough using methods such as baking, boiling, frying, or steaming. Examples of dough-heated foods suitable for application of the present invention include baked goods, takoyaki, and Japanese assorted pancakes.

[0063] In this invention, "baked food" refers to food made from grain flour as the main raw material, with yeast or leavening agent (baking powder, etc.), water, salt, sugar and other auxiliary materials added as needed to obtain a batter dough, which is then subjected to heating treatments such as baking, steaming, and frying.

[0064] Examples of baked goods to which this invention is applicable include: bread; pizza; cakes; Western-style baked goods such as waffles, cream puffs, biscuits, cookies, and crepes; Japanese-style sweets including taiyaki, imakawa-yaki, dorayaki, and ningyo-yaki; fried sweets including cakes, donuts, and potte donuts; and flour-based foods including Japanese assorted pancakes and takoyaki. Examples of bread include: staple bread, bread rolls, white bread, black bread, French bread, dry bread, French olive bread, croissants, tortillas, flavored bread, pastry bread, and steamed buns. Examples of cakes include: sponge cake, cream cake, cake rolls, hot scones, pies, Baumkuchen, pound cake, cheesecake, snack cakes, muffins, stick cakes, and thin pancakes. The baked goods of the present invention can be baked goods obtained without yeast-based fermentation, i.e., baked goods obtained by heating yeast-free dough, or baked goods obtained by yeast fermentation, i.e., baked goods obtained by heating yeast-fermented dough. Specific examples of baked goods particularly suitable for demonstrating the effects of the present invention, especially on improving texture and resistance to deterioration over time, include, for example, cakes (especially muffins, hot scones, steamed cakes, pancakes, Swiss rolls, etc.); Japanese confectionery; fried confectionery; and flour products.

[0065] Furthermore, the heat-treated grain flour of the present invention can also be used in fields other than the food industry. Examples of its use in fields other than the food industry include, when using heat-treated grain flour made from potato starch, applications include: binding feed; binding casting molds, incense sticks, grinding stones, etc.; household detergent paste; and paper strength enhancers.

[0066] Next, a method for improving the aging resistance of food products using the heat-treated cereal flours of the present invention will be described. This method uses heat-treated cereal flours obtained by the manufacturing method of the present invention described above. The description of food products or food compositions using the aforementioned heat-treated cereal flours can be appropriately applied as a method of use.

[0067] This invention includes heat-treated cereal flours manufactured by the manufacturing method of this invention described above. As shown in the embodiments described later, food products made from the heat-treated cereal flours of this invention exhibit excellent aging resistance. However, determining the composition of this heat-treated wheat flour as an article that can distinguish it from heat-treated cereal flours manufactured using prior art methods requires developing new evaluation methods for the characteristics of the cereal flours, which takes a very large amount of time. Under the fast-track application requirement of first-to-file doctrine, this is practically impossible or impractical. Therefore, in this invention, a heat-treated cereal flour as an article is specified by a manufacturing method.

[0068] Example The present invention will now be described in more detail through embodiments. However, the scope of the present invention is not limited to these embodiments.

[0069] [Examples 1-12] Wheat flour was used as the raw material for the cereal flour. Water was added in the amounts shown in Table 1, and the mixture was heated and pressurized under the heat treatment conditions shown in Table 1. The mixture was then extruded. A cooling die was installed at the extruder outlet. The cereal flour exiting the cooling die outlet was cut into appropriate lengths by a cutting device. The cut cereal flour was dried by either a plate dryer at 90°C for 8 hours or a fluidized bed dryer at 135°C for 8 minutes. It was then coarsely pulverized using a roller mill and further pulverized using a pin mill until approximately 20% by mass of the component remained on a 100μm mesh sieve. Through these processes, heat-treated cereal flour was obtained.

[0070] In addition, the applicant confirmed that the difference in the aforementioned drying method did not affect the manufacturing stability or the taste of the resulting heat-treated cereal flour.

[0071] In the extruder, the time (processing time) for maintaining the pressure and heating temperature in Table 1 is in the range of 15 to 60 seconds.

[0072] The cooling die has a cylindrical shape and is installed at the extruder outlet with its cylindrical shaft oriented in the same direction as the extrusion direction. The cooling die has a double-tube structure, consisting of an outer tube and an inner tube located inside it. The cooling die allows refrigerant (fluid) to flow between the double tubes, thereby cooling the contents. The cooling temperature at the outlet side of the cooling die is 27°C. The cooling temperature at the inlet side of the cooling die is 30°C. The total length of the cooling die in the extrusion direction of the extruder is 257 mm. Furthermore, the ratio (S1:S2) of the maximum area (maximum cross-sectional area of ​​the flow path, in this example, the cross-sectional area of ​​the barrel) of the heat-treated material, formed by the extruder barrel and the interior of the cooling die, to the area S2 of the outlet opening, is in the range of 1:0.01 to 1.80. The ratio (Lx / L) of the length of the refrigerant flow section in the same direction of the cooling die to the total length L of the extrusion direction of the extruder is 30% or more. The temperature of the heat-treated material discharged from the cooling die is the temperature shown in Table 1.

[0073] Wheat flour: Chikugomugibatake (Nisshin Flour Milling Co., Ltd., wheat flour from Chikugoizumi) was used.

[0074] The twin-screw extruder used is a TEX-47FSS-25BW-V model manufactured by Nippon Steel Corporation. The screw diameter of this twin-screw extruder is 47 mm, and the opening area (mm²) is... 2 The ratio of the screw diameter (mm) of the extruder to the screw diameter of the extruder is 1.67. It should be noted that the screw diameters of the two shafts of a twin-screw extruder are the same.

[0075] [Comparative Examples 2-8] Without installing a cooling die at the extruder outlet, the mixture is discharged directly from the extruder outlet and cut. Except for these points, the process is the same as in Examples 1-12 to obtain heat-treated grain flour.

[0076] (Evaluation of manufacturing stability) The manufacturing stability of heat-treated cereal flours is evaluated according to the following criteria.

[0077] A: The processes of blocking, blowing, cutting, and drying at the outlet are all in good condition and functioning perfectly.

[0078] B: A blockage or blowout is visible at the outlet, or a small block is observed after cutting, but it is fine.

[0079] C: Blockage or blowout was observed at the outlet, and blocks were observed after cutting, making it difficult to manufacture.

[0080] As mentioned above, observed blowout at the outlet refers to the ejection of a liquid with relatively low viscosity at the outlet. For stability, it is preferable to have little or no such blowout.

[0081] Furthermore, the lumps observed after cutting at the outlet refer to the lumps formed by the cross-sections from the cutting process sticking together, thus creating lumps of heat-treated grain flour near the outlet again. Having fewer or no such lumps prevents poor drying caused by lumps and blockages caused by residual lumps near the cutting outlet, making it preferable from a continuous manufacturing perspective.

[0082] (Preparation of the mixture for making pancakes) Using any of the heat-treated grain flours from the Examples and Comparative Examples, a pancake mixture was prepared as a type of processed food mixture. The prepared pancake mixture consisted of 77.0% by mass wheat flour, 19.2% by mass sugar, and 3.8% by mass baking powder (total 100% by mass). Of the wheat flour used in the pancake mixture, 90% by mass was unprocessed wheat flour (thin flour, manufactured by Nisshin Flour Co., Ltd. as "Flower"), and the remaining 10% by mass was heat-treated grain flour.

[0083] In addition, except that the above-mentioned unprocessed wheat flour is used as the wheat flour, the mixture for making pancakes in the control example is made in the same way as above.

[0084] [Evaluation Test] Using the above-mentioned pancake mixture, pancakes were manufactured by the following method. After cooling in an environment with an atmosphere temperature of 27°C for 30 minutes, the manufactured pancakes were wrapped in packaging film and stored in a refrigerator at an internal temperature of 4°C for 1 day and 3 days, respectively.

[0085] The pancakes, which had been stored in the refrigerator for 1 day and 3 days respectively, were immediately removed from the refrigerator and tasted by 10 professional judges. The judges scored the pancakes based on the following evaluation criteria. The average scores are shown in Table 1.

[0086] (Making pancakes) In a bowl, combine 65g of pancake mix, 5g of salad oil (as liquid), 15g of whole egg liquid, 25g of milk, and an appropriate amount of water. Using a mixer, manually stir at 120 rpm to prepare a pancake dough with a viscosity of 5-10 Pa·s based on a Type B viscometer at a product temperature of 25°C. Adjust the amount of water added to achieve the desired viscosity. After the pancake dough has been prepared, allow it to rest for 10 minutes. Then, pour 55g of the dough into a shallow pan and bake one side of the dough at 180°C for 3 minutes. Flip the dough over and bake the other side for 2 minutes to create the pancakes.

[0087] <Evaluation Criteria for Moisture Sensitivity> 5 points: Quite moist, very good.

[0088] 4 points: Moist, good.

[0089] 3 points: Slightly moist, good.

[0090] 2 points: Not moist, slightly undesirable.

[0091] 1 point: Not moist at all, poor.

[0092] As shown in Table 1, in the extrusion process, in each embodiment where a cooling die was installed at the extruder outlet, compared to the comparative examples where it was not installed, the internal pressure of the extruder was increased, and the feeling of moisture persisted even after 3 days of refrigerated storage. In contrast, in Comparative Examples 1-8 where a cooling die was not used, the feeling of moisture after refrigerated storage was poor. Furthermore, in Comparative Examples 7 and 8, it was observed that the heat-treated material was blown out at the extruder outlet.

[0093] [Examples 13-27] In Example 10, as shown in Table 2, the total length (mm) of the extrusion direction of the cooling die, the screw diameter (mm) of the extruder, and the pressure (barrel front pressure, MPa) were changed to produce heat-treated grain flour. The amount of water added (parts by mass) in the extrusion process was also changed. Otherwise, the evaluation was conducted in the same manner as in Example 10. In Examples 13 and 14, where the screw diameter (mm) of the extruder was 65mm (different from Example 10), a twin-screw extruder (Bühler Corporation, model BCTG-62 / 20D) was used. It should be noted that in the following tables, "none" in the die exit side cooling temperature and inlet side cooling temperature indicates that no refrigerant flowed in the cooling die.

[0094] The evaluation results are shown in Table 2. The results of Example 10 are also shown in Table 2.

[0095] According to Table 2, a comparison between Example 15 and Example 10 shows that when the refrigerant flows in the cooling die, the pressure inside the extruder increases, and there is a tendency to obtain effects such as improved taste. On the other hand, a comparison between Examples 13 and 14 and Example 15 shows that in a cooling die with a double-tube structure, by adjusting the length and opening area, the internal pressure can be increased, and the effect of improved taste can be obtained even when the refrigerant is not flowing.

[0096] Furthermore, according to Table 2, the opening area (mm) of the outlet opening of the aforementioned cooling die head is... 2 Within the specified range indicated by () / (extruder screw diameter mm), the moistness persists even after 3 days of refrigerated storage, and the manufacturing stability is also good.

[0097] [Examples 28 and 29] In Example 10, the cooling temperature in the cooling head and the presence or absence of cooling by refrigerant flow were changed, as shown in Table 3. Everything else was the same as in Example 10. The results are shown in Table 3. The results of Example 10 are also shown in Table 3.

[0098] As shown in Table 3, by allowing the refrigerant to flow in the cooling die with a double-tube structure, the cooling effect is improved, which can increase the pressure inside the extruder and achieve excellent taste and other improvements.

[0099] Industrial availability According to the present invention, heat-treated cereal flours that can impart a good taste to food and resistance to degradation over time can be manufactured.

Claims

1. A method for manufacturing heat-treated cereal flour, comprising the steps of mixing water in cereal flour using an extruder and subjecting it to heating and pressurization to manufacture heat-treated cereal flour. A cooling die is installed at the outlet of the heat-treated material in the extruder.

2. The method for manufacturing heat-treated cereal flour according to claim 1, wherein, In the cooling die, the opening area of ​​the outlet opening facing the extrusion direction of the extruder is 20 mm. 2 The cooling die head described above has a total length of 60 mm or more in the extrusion direction of the extruder.

3. The method for manufacturing heat-treated cereal flour according to claim 1, wherein, The cooling die head has an outlet opening area of ​​(mm). 2 The ratio expressed as () / (screw diameter of the extruder in mm) is greater than or equal to 0.11 and less than or equal to 11.

8.

4. The method for manufacturing heat-treated cereal flour according to claim 1, wherein, The extruder is a twin-screw extruder.

5. The method for manufacturing heat-treated cereal flour according to claim 1, wherein, The cooling head has a double-tube structure, which has an outer tube and an inner tube located inside the outer tube, allowing refrigerant to flow between the outer tube and the inner tube, and cooling the contents through heat exchange with the refrigerant.

6. The method for manufacturing heat-treated cereal flour according to claim 1, wherein, In the extruder, the amount of water mixed into the cereal flour is 40 parts by mass or more per 100 parts by mass of the cereal flour.

7. A heat-treated cereal flour product, manufactured by the manufacturing method according to any one of claims 1 to 6.

8. A food product that uses the heat-treated cereal flour as described in claim 7.

9. A food composition comprising the use of the heat-treated cereal flour as described in claim 7.

10. A method for improving the aging resistance of a food product, wherein the heat-treated cereal flour as described in claim 7 is used.

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