Alpha-starch and method for producing same

Abstract

The present invention provides a gelatinized starch having a gelation degree of 13.0 or more and a travel distance of 3.30 cm or less. Wherein the gelatinization degree is the ratio (Wf / Ws) of the amount (Wf) of the gelatinized starch generated when the gelatinized starch is mixed with 100 times by mass of water to the amount (Ws) of the gelatinized starch before mixing, and the travel distance is the travel distance of 10 g of the gel obtained by mixing water with the gelatinized starch so that the moisture content of the obtained gel is 90.9 mass%. The present invention also provides a dough heated food product using the gelatinized starch, and a baked food product obtained by heating a batter dough containing the gelatinized starch.

Description

Technical Field

[0001] This invention relates to α-starches suitable for food applications. Background Technology

[0002] Alpha-treated starch is starch that has been gelatinized (α-adapted) by heating raw starch in the presence of moisture. Due to α-adaptation, the molecular arrangement within the starch granules collapses, resulting in irreversible changes such as swelling of the starch granules, loss of birefringence, melting of natural microcrystals, and soluble starch. Therefore, α-treated starch exhibits unique properties different from the raw starch and is widely used in food and industrial applications.

[0003] On the other hand, due to changes in consumer preferences and lifestyles in recent years, there is a growing demand for food products that offer a moist texture and resistance to changes in texture over time.

[0004] To suppress dryness caused by aging, a method is known to replace a portion of wheat flour, the main ingredient in bread, with α-starch (e.g., Patent Document 1). However, the conventional α-starch described in Patent Document 1 does not impart sufficient aging resistance.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 59-175845 Summary of the Invention

[0006] Therefore, the objective of this invention is to provide an α-starch that imparts superior aging resistance and a superior, moist texture to food compared to conventional methods.

[0007] The present invention provides α-starch with a gelation degree of 13.0 or higher and a travel distance of 3.30 cm or less.

[0008] The degree of gelation is the ratio of the amount of gel formed (Wf) when α-starch is mixed with 100 times the mass of water to the amount of α-starch before mixing (Wf / Ws). The travel distance is the distance that 10g of gel formed by mixing water and α-starch in such a way that the water content of the resulting gel is 90.9% by mass is moved.

[0009] Furthermore, the present invention provides a method for manufacturing α-starch, which is the aforementioned method for manufacturing α-starch, and includes steps of adding water and heating the raw starch. The amount of water added in the above process is 150 parts by weight or more relative to 100 parts by weight of the starch raw material, and the heating temperature is 90°C or higher and 165°C or lower. Detailed Implementation

[0010] The α-starch derivative of the present invention has a gelation degree of 13.0 or higher and a travel distance of 3.30 cm or less.

[0011] In this specification, "starch" refers to both starch and cereal flours with starch as the main component, which are powdery substances at room temperature and pressure. The "starch" used here refers to "pure starch" isolated from plants such as wheat, distinguished from the starch inherent in cereal flour or whole grain flour. It should be noted that, in the following instances, when "starch" is used in this specification, the context will determine whether it refers to pure starch or the starch inherent in cereal flour or whole grain flour.

[0012] The grains mentioned above that are sources of "starch" include cereals (seeds of grasses), pseudo-cereals (seeds of dicotyledons), legumes (seeds of legumes), and tubers (roots or tubers that are eaten), all of which contain starch as a component.

[0013] 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.

[0014] Specific examples of starch include potato starch, wheat starch, corn starch, waxy corn starch, rice starch, and tapioca starch.

[0015] In this invention, from the perspective of smoothly obtaining the above-mentioned degree of gelation and the above-mentioned travel distance, and from the perspective of easy handling due to the absence of foaming in the slurry, starch is preferably used as the raw material starch for α-starch. Among starch and grain flour, starch is preferred.

[0016] In particular, in this invention, from the viewpoint that foods using the α-starch of this invention have excellent moist texture (hereinafter also referred to as "moisture") and aging resistance, starches with an amylose content of less than 5% are preferred as the raw material for α-starches. Starches with an amylose content of less than 5% are typically starches with an amylopectin content of more than 95%. A higher amylopectin content allows for the retention of a large amount of water, easily increasing the degree of gelation. By using such a water-retaining starch, α-starches with a certain degree of gelation and a certain distance of travel are produced, resulting in particularly excellent moist texture and aging resistance. Glutinous starches with an amylose content of less than 5% are an example of starches. Glutinous starches can be derived from corn, rice, potatoes, etc. In particular, from the viewpoint that foods using α-starches have particularly excellent moist texture and aging resistance through a water addition and heating process under specific conditions, waxy corn starch is preferred.

[0017] The α-starch derivatives and their raw starches of the present invention are preferably unmodified. Conventionally, processed starches for aging resistance have been known to be chemically modified, such as phosphate-crosslinked starch and hydroxypropyl etherified phosphate-crosslinked starch. However, these are food additives, and due to increased awareness of clean labeling in recent years, they tend to be disliked by consumers. In contrast, the α-starch derivatives of the present invention, being unmodified, exhibit excellent aging resistance and are not food additives, thus making them more readily accepted by consumers who dislike food additives, and are therefore preferred. Furthermore, the method for manufacturing the α-starch derivatives of the present invention, described later, has the advantage of imparting excellent aging resistance to starches even without using chemically modified starches.

[0018] Chemical modification refers to the treatment of starch by introducing modifying groups through chemical agents. Examples of chemically modified starches include acetylated adipic acid crosslinked starch, acetylated phosphoric acid crosslinked starch, acetylated oxidized starch, sodium octenyl succinate starch, acetic acid starch, oxidized starch, hydroxypropyl starch, hydroxypropylated phosphoric acid crosslinked starch, phosphorylated monoesterified phosphoric acid crosslinked starch, phosphorylated starch, and phosphoric acid crosslinked starch, all of which are designated as food additives. It should be noted that α-modified starches are preferably not oil-processed starches.

[0019] The α-starch derivative of the present invention has a gelation degree of 13.0 or higher and a travel distance of 3.30 cm or less. The inventors conducted in-depth research on the composition of α-starch derivatives that can impart superior aging resistance and moisture retention to food compared to previous methods. The results showed that the aforementioned problems can be solved by combining specific parameters related to the water retention and flowability of α-starch derivatives.

[0020] The degree of gelation is defined as the ratio (Wf / Ws) of the amount of gel formed when α-starch is mixed with 100 times its mass of water to the amount of α-starch before mixing. The α-starch of the present invention exhibits excellent gelation properties by retaining a large amount of water. The inventors have discovered that α-starch with a gelation degree of 13.0 or higher effectively imparts a moist texture to foods using it, even after heating. From the viewpoint of further enhancing the moist texture, the degree of gelation of the α-starch of the present invention is preferably 13.2 or higher, particularly preferably 13.5 or higher. Furthermore, a gelation degree of, for example, 30.0 or lower is preferred in terms of a smooth and soft texture. The degree of gelation is measured using the following method.

[0021] <Method for determining the degree of gelation> The weight (Ws) of a 2 ml eppendorf tube was determined. After weighing, 1.5 ml of deionized water (25°C) was added to the tube, followed by 0.015 g (Ws) of α-starch (calculated as dry weight). After adding the α-starch, the tube cap was closed, and vortexing was immediately applied to prevent clumping. The vortexed tube was centrifuged at 10°C and 15000 rcf for 30 minutes. After centrifugation, the tube was removed from the centrifuge, the cap was removed, and only the supernatant was discarded. The weight (Wg) of the tube was then determined. The centrifuged tube was handled carefully without vibration. The degree of gelation was calculated using the following formula. The degree of gelation is defined as the average of at least six measurements for each sample.

[0022] (Degree of gelation) = (Wg - We) / Ws The above formula Wg-We corresponds to the amount of gel formed, Wf.

[0023] Dry weight refers to the weight of, for example, 3.0 g of α-starch dried at 135°C for 1 hour.

[0024] As a method for discarding the supernatant, it can be tilted by moving the tube with the cap on vertically upright by 60°, and then aspirated by a pipette in this state. The pipette tip preferably has a capacity of 100 μl or less.

[0025] Additionally, the vortex lasts for 10 seconds.

[0026] Furthermore, the α-starch of the present invention has a travel distance of 3.30 cm or less. Here, travel distance refers to the distance traveled by 10 g of gel obtained by mixing water and α-starch in such a way that the moisture content of the resulting gel is 90.9% by mass. Although the degree of gelation is high, a travel distance of less than a certain amount indicates that the gel retains a certain amount of water with low fluidity, that is, high water retention capacity and excellent gelation performance (gel shape retention). Therefore, it is believed that α-starch with a certain degree of gelation and a certain travel distance can retain more water and has excellent water retention performance. The inventors have found that when α-starch with a certain degree of gelation and a certain travel distance is used in food, it imparts excellent aging resistance in addition to excellent moisture content after heating. In the present invention, the travel distance of the α-starch is 3.30 cm or less, preferably 3.27 cm or less, and more preferably 3.24 cm or less. In addition, the travel distance of the α-starch is particularly preferably 0.3 cm or more.

[0027] Specifically, the distance traveled was determined using the following methods.

[0028] <Methods for measuring distance traveled> Add water (25°C) and α-starch to a container to make the total weight of the resulting gel 55g, with a water content of 90.9% by mass. Stir 50 times with a hand mixer.

[0029] After stirring, let stand at room temperature (25°C) for 10 minutes, then fill 10g of the gel into a 15ml centrifuge tube (inner diameter: 15mm) and place it in a centrifuge (30min, 10°C, 3500rpm). After centrifugation, handle the gel carefully without vibration. Remove the cap from the centrifuge tube and measure the distance the gel travels when placed flat (set the vertical graduation to 0). Specifically, measure the distance the gel travels from the bottom to the top of the centrifuge tube when it is placed horizontally.

[0030] The travel distance for each sample was measured at least four times, and the average value was recorded.

[0031] Remove the cap from the centrifuge tube and place it flat. Tilt the vertical centrifuge tube 90° to lay it horizontally. The tilting operation is preferably performed at a speed of 10° / second to 30° / second, and the tube should be quietly placed on a horizontal surface. The movement distance is measured 30 seconds after the centrifuge tube is laid horizontally. Furthermore, the movement distance is measured at room temperature (25°C).

[0032] Furthermore, the hand mixer was used at a speed of 150 rpm for 50 cycles, with each cycle lasting 0.4 seconds. The hand mixer can be manufactured by Jugo Kosei Corporation, but is not limited to this type.

[0033] In addition, the centrifuge tubes used are specifically IWAKI's trade name "15mL 2325-015-MYP" (made of polypropylene), but centrifuge tubes of the same shape and material can also be used.

[0034] In this invention, the average particle size of the α-starch is preferably 15.0 μm or more, more preferably 20.0 μm or more. Furthermore, the average particle size of the α-starch is preferably 700.0 μm or less, more preferably 65.00 μm or less. The average particle size of the α-starch in the embodiments described later is in the range of 20.0 μm or more and 65.00 μm or less. 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.).

[0035] Next, a preferred manufacturing method for the α-starch of the present invention will be described.

[0036] This manufacturing method includes steps of adding water to a starchy raw material and heating it. The amount of water added in this step is 150 parts by weight or more relative to 100 parts by weight of the starchy raw material, and the heating temperature is 90°C or higher and 165°C or lower. The description of the starchy raw material is as described above. As mentioned above, the starchy raw material is preferably starch with an amylose content of 5% or less, and waxy corn starch is particularly preferred. Regarding the average particle size of the starchy raw material, from the perspective of more easily obtaining suitable gelation degree and travel distance through water addition and heating treatment, it is preferably 5.0 μm or more, and even more preferably 250 μm or less. The average particle size of the starchy raw material in the embodiments described later is in the range of 5.0 μm or more and 250 μm or less.

[0037] The process of adding water and heating the raw starch refers to a process in which the raw starch is simultaneously treated with water and heated, or a process in which the raw starch is treated with water and then the resulting hydrated product is heated. Through this heating treatment, the starch contained in the raw starch is α-treated, and the raw starch becomes α-treated starch. Therefore, the heating treatment is also called α-treatment. From the viewpoint of simplicity in the manufacturing process, the preferred process for adding water and heating the raw starch is the process of adding water to the raw starch and then heating the resulting hydrated product.

[0038] In the above-described water addition process, the raw starch and water are mixed at a ratio of 150 parts by mass or more per 100 parts by mass of the raw starch. By including such a large amount of water in the raw starch, which is the heated element, the side chains of the starch contained in the starch become easier to open after heating at a specified temperature. Furthermore, the side chains of the starch become less susceptible to damage caused by heating. As a result, the gelation properties and water retention properties of the starch are improved, and α-formed starch with a gelation degree of ≥ the aforementioned specific value and a travel distance of ≤ the aforementioned specific value is easily obtained. When the amount of water added is less than 150 parts by mass per 100 parts by mass of the raw starch, such effects of the present invention cannot be achieved.

[0039] In the above-described water addition process, the amount of water added relative to 100 parts by weight of the raw starch is preferably 150 to 1500 parts by weight, more preferably 150 to 1200 parts by weight, and even more preferably 150 to 1000 parts by weight. If too much water is added, more time and energy will be required to obtain a solid product in the drying process after the water addition and heating steps, which may lead to increased production costs and reduced production efficiency. Furthermore, the temperature of the water used for adding water is not particularly limited; for example, a range of 0°C to 100°C can be cited. In this invention, typically, the above-described amount of water is added as a liquid.

[0040] The aforementioned heat treatment needs to be carried out at a product temperature of 90°C or higher and 165°C or lower for the added water-containing starch. In this invention, as described above, more than 150 parts by weight of water are added to 100 parts by weight of the raw starch to prepare a more hydrated raw starch. This is presumably more likely to open the side chains of the starch contained in the raw starch, suppress starch damage during heating, improve the degree of gelation, and reduce the travel distance. By heating the more hydrated raw starch under the above conditions, the gelation and water retention properties of the obtained α-starch can be significantly improved, producing an α-starch with a certain degree of gelation and a certain travel distance.

[0041] When raw starch with added water to a certain amount is heated to a certain temperature or above, starch modification occurs, easily yielding the α-modified starch of this invention with a certain degree of gelation. From this perspective, the product temperature of the raw starch during the heating process of the added-water raw starch is preferably 90°C or higher, more preferably 95°C or higher, and even more preferably 100°C or higher. Heating the raw starch at a product temperature exceeding 100°C can be achieved, for example, by heating the added-water raw starch under a pressurized atmosphere, or by heating the surface of a heated iron plate or roller.

[0042] Furthermore, if the heating temperature of the raw starch with added water is too high, the shape-preserving function of the resulting α-starch gel will be damaged, and the gelation performance will actually decrease. Therefore, it does not belong to the α-starch of this invention, which has a certain degree of gelation and a certain distance of travel. Based on this, the heating temperature for heating the raw starch is preferably below 165°C, and more preferably below 150°C.

[0043] In this specification, heating at the specified temperature refers to heating after the starchy raw material has gelatinized. Gelatinization of the starchy raw material can be determined by the transparency of the paste.

[0044] In the above heat treatment, the heating time (the time for maintaining the product temperature) of the α-starch with added water is not particularly limited; for example, it can be less than 50 minutes, less than 40 minutes, or less than 30 minutes. Gelatinization is preferably carried out in the range of 90°C to 165°C. In the heat treatment, the time for maintaining the product temperature can be 0 minutes, more than 1 minute, or more than 10 minutes. The above time can be set as the time for gelatinizing the raw starch.

[0045] In the above-described water treatment, the slurry containing raw starch and water typically contains only raw starch and water as a solvent. However, it may also contain other components as needed, such as starch modifiers that can be used in the pretreatment of the raw starch. The starch modifier is a preparation capable of modifying starch to desired properties; examples include enzymes, acids or alkalis, sugars, amino acids, peptides, thickeners such as viscous polysaccharides, etc. Examples of enzymes include amylase and proteases that decompose proteins contained in starch. When the slurry contains components other than raw starch and water, the amount of these other components relative to 100 parts by weight of raw starch is preferably 10 parts by weight or less, more preferably 3 parts by weight or less, further preferably 1 part by weight or less, even more preferably 0.5 parts by weight or less, and particularly preferably 0.1 parts by weight or less.

[0046] Preferably, the process of adding water and heating the raw starch includes a slurry preparation process of mixing water and raw starch to prepare a slurry, and a slurry heating process (α-treatment) of heating the obtained slurry. Since it is easy to obtain α-treated starch with the above-mentioned gelation degree and the above-mentioned travel distance, it is preferable to perform each treatment process in sequence.

[0047] In cases where the above-mentioned water addition and heating processes include slurry preparation and slurry heating, 1) in slurries containing starch pretreated with a starch modifier, a starch modifier that is the same as or different from that starch modifier may be contained; or 2) in slurries containing starch that has not been pretreated with a starch modifier, a starch modifier may be contained. It should be noted that in slurries containing starch modifiers, reactions related to the starch modifier, such as enzymatic reactions, may occur. These reactions may be completed before the slurry is supplied to the subsequent drying process, or they may occur during the drying process.

[0048] The heating method described above is not particularly limited as long as it can withstand the conditions of high water content and high temperature. A typical heating method is to contain a starch-based slurry in a container and heat the container. The heating of the slurry can be carried out in batches or continuously. As a container for holding the slurry during heating, a pressure vessel can be used in the case of batch heating, and a pipeline mixer such as a static mixer can be used in the case of continuous heating. There are no particular limitations on the heating mechanism; for example, electric, gas, and steam types can be used, and one of them can be used alone or in combination of two or more. As a heating method for slurry using a steam heating mechanism, for example, a method of directly introducing saturated steam or superheated steam into a container containing the substance to be dried (starch) can be cited.

[0049] In the heat treatment of the slurry, it is preferable to stir the slurry during heating. If the slurry is heated in a static state without stirring, the starch contained in the slurry will clump together, potentially leading to insufficient and uneven α-oxidation of the starch. However, by stirring the slurry during heating, such undesirable conditions can be prevented, and α-oxidation of the starch can be promoted. The stirring method for the slurry is not particularly limited as long as it can disperse the contained starch throughout the slurry. Typically, a known container with a stirrer, which has a container and a stirrer for stirring the contents of the container, can be used, following conventional methods. For example, in the case of batch heating of the slurry, a device with stirring blades can be illustrated; in the case of continuous heating, a static mixer can be illustrated. Alternatively, a known ultrasonic vibration generating mechanism can be used as the slurry stirring mechanism, in which the slurry is stirred by generating fine bubbles in the slurry through the vibration of ultrasonic waves generated from the ultrasonic vibration generating mechanism. Alternatively, instead of using a stirring tool like a stirring blade, the heated slurry can be stirred by blowing steam or other gases into it.

[0050] The aforementioned slurry heat treatment is preferably completed when the slurry to be heated contains at least 150 parts by mass of water relative to 100 parts by mass of the raw starch. This is because if the water content of the slurry after the aforementioned heat treatment (e.g., the slurry supplied to the subsequent slurry drying process) is less than 150 parts by mass relative to 100 parts by mass of the raw starch, the α-oxidation of starch in the raw starch is suppressed during this heat treatment, potentially preventing the achievement of the effects specified in this invention.

[0051] As described above, one example of a method for ending the slurry heating process when the slurry contains at least 150 parts by mass of water relative to 100 parts by mass of the raw starch is a method of heating the slurry under a pressurized atmosphere, i.e., an atmosphere pressure exceeding 1 atmosphere. In this case, the container holding the slurry preferably has pressure resistance. The pressure of the pressurized atmosphere can be appropriately adjusted according to the amount of solvent contained in the slurry and the heating temperature (the product temperature of the slurry), without particular limitations. Since the upper limit temperature of the slurry accompanied by heating depends on the pressure, it is preferable to set the pressure to correspond to the required heating temperature.

[0052] Another example of a method that ends when the slurry to be heated contains 150 or more parts by mass of water relative to 100 parts by mass of the raw starch can be a case where heating is performed at atmospheric pressure and a gas such as steam is blown into the slurry using a linear heating device.

[0053] Next, the heated slurry is preferably dried. In this drying process, the slurry heated in the above-described heat treatment is dried to obtain a solid containing α-glycosidic starch. There are no particular limitations on the drying method of the slurry; known drying methods can be used, such as freeze drying, spray drying using a spray dryer, and heat drying using a drum dryer. There are no particular limitations on the degree of drying of the slurry, but typically, the moisture content of the solid obtained by drying the slurry is dried to the same level as the moisture content of the raw starch used in the above-described slurry preparation process, more specifically, to about 15% by mass.

[0054] The solid material obtained from the above-mentioned slurry drying process can be used directly as α-starch or pulverized into powder. Pulverization of the solid material can be performed using household grinders such as coffee grinders and juicers; or using industrial grinders such as hammer mills, pin mills, and jet mills, following conventional methods, until the solid material reaches the desired particle size.

[0055] The α-starch produced by the manufacturing method of this invention (hereinafter also referred to as "specific α-starch") can be used in place of known α-cereal flour and α-starch, and is typically used in the food industry for the manufacture of processed foods. Processed foods, as described herein, are manufactured using starch as a raw material, 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 be frozen foods. The α-starch obtained by the manufacturing method of this invention is particularly suitable for baked goods, producing baked goods with excellent moisture content and good taste, 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.

[0056] Next, compositions containing the α-starch of the present invention will be described. Examples of compositions of the present invention include those containing starches containing the α-starch of the present invention, preferably compositions containing both the α-starch and non-α-starch of the present invention, and particularly preferably compositions containing both the α-starch and non-α-starch of the present invention. Dough mixtures are an example of such compositions. Examples of components used in dough mixtures, i.e., 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.

[0057] The α-starch compounds and compositions 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 (octopus balls), and Japanese assorted pancakes.

[0058] 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.

[0059] 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, savory 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 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 that particularly utilize the effects of the present invention, especially its moist texture and resistance to aging, include cakes (especially muffins, hot scones, steamed cakes, pancakes, Swiss rolls, etc.); pastries; fried pastries; and flour-based foods.

[0060] Furthermore, the α-starch derivative of the present invention can also be used in fields other than the food industry. Examples of its use outside the food industry include, when using potato starch to manufacture α-starch derivatives as a starch, applications such as feed binders; binders for casting molds, incense sticks, grinding stones, etc.; household detergent pastes; and paper strength enhancers.

[0061] Example The present invention will now be described in more detail by way of examples, but the present invention is not limited to these examples. It should be noted that in the following examples, the slurry was freeze-dried, but the same result was obtained when the solid was obtained by heating and drying using a drum dryer (D-0303 double drum type, manufactured by Katsuragi Kogyo Co., Ltd.).

[0062] [Examples 1-18, Comparative Examples 1-5] Using waxy corn starch as a raw material, water was added at the ratio shown in Table 2 to prepare an aqueous slurry (slurry preparation process). The slurry was gelatinized in a hot water bath at 100°C (except for Examples 13, Comparative Examples 3 and 5) while being stirred, and then further heated at the heating temperatures shown in Table 2 for the following heating times. Table 2 shows the heating time from reaching the target temperature. In Example 13, gelatinization was performed in a hot water bath at 90°C, and in Comparative Examples 3 and 5, gelatinization was performed in a hot water bath at 80°C.

[0063] Heating time: 30 minutes for Examples 1-14 and Comparative Examples 1-5.

[0064] Examples 15-18 are the times shown in Table 2.

[0065] It should be noted that when the heating temperature is below 100°C, a hot water bath is used for heating; when the temperature exceeds 100°C, an autoclave or a Cooker static mixer (manufactured by Noritake) is used for heating. The slurry (gelatinized liquid) after the above-mentioned slurry heating treatment is freeze-dried using a commercially available freeze dryer (trade name "Virtis Wizard 2.0 Lyophilizar Controller", manufactured by SP INDUSTRES, Inc.) to obtain a solid (slurry drying process). The obtained solid is pulverized using an ultracentrifuge to produce α-starch. For the obtained α-starch, the degree of gelation and travel distance are measured using the above method. The degree of gelation is measured in 6 steps, and the travel distance is measured in 4 steps.

[0066] As a waxy corn starch, "Japanese-style Waxy Starch IPY" manufactured by Nippon Food Chemical Co., Ltd. is used.

[0067] Using the obtained α-starch, bake foods are prepared according to the proportions shown in Table 1 below and the following steps.

[0068] <Steps for manufacturing baked goods> Combine salad oil, eggs, milk, and water in a bowl and mix. Add baking powder, alpha starch, and leavening agent, and mix with a hand mixer for 60 seconds (120 rpm). After a 10-minute delayed fermentation time, place a 50g piece of dough in a skillet and bake at 180°C for 3 minutes on the surface, then flip and bake the other side for 3 minutes to obtain 4 hot pancakes.

[0069] In addition, as a thin powder, it uses "Flower" manufactured by Nisshin Flour Milling Co., Ltd.

[0070] Additionally, "Baking Powder MeisterAll" manufactured by Oriental Yeast Co., Ltd. is used as an expanding agent.

[0071] <Recipe> After storing the hot baked biscuits at 4°C for 3 days, their moisture and melt-in-your-mouth properties were evaluated according to the following criteria. The evaluation was conducted by 8 professional evaluators. The average values ​​are shown in Table 2 below. To facilitate the perception of aging, the test was conducted by tasting the hot baked biscuits at chilled temperatures.

[0072] <Evaluation Criteria for Moisture Sensitivity> 5 points: Quite moist, very good.

[0073] 4 points: Moist, good.

[0074] 3 points: Slightly moist, good.

[0075] 2 points: Not moist, slightly undesirable.

[0076] 1 point: Not moist at all, poor.

[0077] <Evaluation Criteria for Mouth-Dissolving Texture> 5 points: It dissolves very well in the mouth, which is excellent.

[0078] 4 points: Good oral solubility.

[0079] 3 points: Slightly good oral solubility, good.

[0080] 2 points: Slightly sticky, slightly poor mouth solubility.

[0081] 1 point: Feels sticky, poor mouth solubility.

[0082] As shown in Table 2, it can be seen that by using α-starch with a gelation degree of 13.0 or higher and a travel distance of 3.30 cm or less, the moisture and mouth-melting properties of baked goods are improved.

[0083] Industrial availability According to the present invention, α-starches can be provided that impart excellent aging resistance and excellent and moist mouthfeel when used in food.

Claims

1. An α-starch derivative having a gelation degree of 13.0 or higher and a travel distance of 3.30 cm or less. in, The degree of gelation is the ratio of the amount of gel formed (Wf) when α-starch is mixed with 100 times its mass of water to the amount of α-starch before mixing (Wf / Ws). The travel distance is the distance 10g of a gel formed by mixing water and α-starch in such a way that the water content of the resulting gel is 90.9% by mass is moved.

2. A method for manufacturing α-starch, which is the method for manufacturing α-starch as described in claim 1, wherein, It includes processes for adding water and heating raw starch. The amount of water added in the process is more than 150 parts by weight relative to 100 parts by weight of the raw starch, and the heating temperature is above 90°C and below 165°C.

3. The method for manufacturing α-starch according to claim 2, wherein, The amount of water added in the process is less than 1500 parts by weight relative to 100 parts by weight of the raw starch.

4. The method for manufacturing α-starch according to claim 2, wherein, The average particle size of the raw starch is above 5.0 μm and below 250 μm.

5. The method for manufacturing α-starch according to claim 2, wherein, The starch used as the raw material is a starch with an amylose content of less than 5%.

6. The method for manufacturing α-starch according to claim 5, wherein, Waxy corn starch is used as the starch with a linear starch content of less than 5%.

7. The method for manufacturing α-starch according to claim 2, wherein, The raw starch is α-modified starch that has not undergone chemical modification.

8. A composition comprising the α-starch of claim 1 or the α-starch produced by any one of claims 2 to 7.

9. A dough-heated food product, which uses the α-starch as described in claim 1 or the α-starch manufactured by any one of claims 2 to 7.

10. The dough-heated food product according to claim 9, which is a baked food product made by heating a dough containing the α-starch.

Images