Manufacturing method of brown rice, brown rice molded food, and manufacturing method of frozen brown rice

Abstract

To provide a method for producing brown rice having excellent texture and suppressed unique odor of the brown rice, and brown rice molded food, as well as a method for producing frozen brown rice.SOLUTION: A method for producing brown rice comprising the steps of (1) roasting brown rice, (2) bringing the roasted brown rice into contact with hot water, and (3) cooking the brown rice after contact with hot water to obtain cooked brown rice. If a mixture of non-glutinous brown rice and colored (e.g., black rice, etc.) brown rice is used as the brown rice, brown rice containing not only nutrients derived from non-glutinous rice but also nutrients derived from colored rice can be obtained. By roasting the raw brown rice and bringing the roasted brown rice into contact with hot water, the brown rice can be cooked without soaking for a long time, and the obtained cooked brown rice has an excellent texture and suppresses the odor unique to brown rice. The produced brown rice can also be frozen to obtain frozen brown rice.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for producing brown rice having an excellent texture and suppressing the odor peculiar to brown rice, a formed brown rice food product, and a method for producing frozen brown rice. [Background technology]

[0002] It is generally known that brown rice is more nutritious than polished rice. However, brown rice has a white rice layer (endosperm) that is covered from the outside with a wax layer and then a bran layer (pericarp, seed coat, and aleurone layer). Because brown rice has these wax and bran layers, cooked brown rice has the disadvantages of having a distinctive brown rice odor and dryness, and a poor texture and taste.

[0003] Methods of cooking brown rice to obtain brown rice with a good texture have been reported, for example, by soaking brown rice with a scratched surface (three-minute brown rice) in water, fermenting it with bacteria attached to the brown rice, and cooking it after it has been covered with mycelium (Patent Document 1), and by adding water to brown rice that has been coarsely ground to a size of 1 to 3 mm in major axis and 0.5 to 2 mm in minor axis (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-220060 A [Patent Document 2] JP 2010-200631 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the method of Patent Document 1, brown rice is soaked in water for a long time (8 to 15 hours) to ferment bacteria attached to the brown rice, which can cause the brown rice to have an acidic odor and make it difficult to eat. In addition, in the method of Patent Document 2, coarsely ground brown rice is cooked, which causes the grains of the resulting brown rice to become small and the texture to become poor.

[0006] Under these circumstances, an object of the present invention is to provide a method for producing brown rice having an excellent texture and suppressing the odor peculiar to brown rice, a brown rice molded food product, and a method for producing frozen brown rice. [Means for solving the problem]

[0007] As a result of intensive research aimed at solving the above problems, the present inventors discovered that the following invention meets the above object, and thus completed the present invention.

[0008] That is, the present invention relates to the following inventions. <1> A step (1) of roasting brown rice; A step (2) of contacting the roasted brown rice with hot water; (3) cooking the brown rice after contact with the hot water to obtain brown rice; A method for producing brown rice having the above structure. <2> The brown rice is a mixture of non-glutinous brown rice and colored brown rice. <1> The method for producing brown rice described in the above. <3> The colored rice is at least one selected from black rice, red rice, and green rice. <2> The method for producing brown rice described in the above. <4> <1> from <3> 2. A molded brown rice food product obtained by molding brown rice produced by the manufacturing method described in any one of the above. <5> It is a rice ball <4> The formed brown rice food product according to claim 1.

[0009] <1a> A process (1) of roasting brown rice; A step (2) of contacting the roasted brown rice with hot water; (3) cooking the brown rice after contact with hot water; A step (4) of freezing the obtained brown rice to obtain frozen brown rice; A method for producing frozen brown rice having the above structure. <2a> The method for producing frozen brown rice according to <1a>, wherein the brown rice is a mixture of non-glutinous brown rice and colored brown rice. <3a> The method for producing frozen brown rice according to <2a>, wherein the colored rice is at least one type selected from black rice, red rice, and green rice. <4a> The method for producing frozen brown rice according to any one of <1a> to <3a>, wherein in step (4), freezing is performed by applying a uniform magnetic flux and electromagnetic waves. <5a> The method for producing frozen brown rice according to any one of <1a> to <4a>, wherein in step (4), the brown rice is formed into a predetermined shape and then frozen. <6a> <5a> A frozen brown rice shaped food produced by the production method described in <6a>. <7a> A frozen brown rice shaped food product according to <6a>, which is a rice ball. Effect of the Invention

[0010] According to the present invention, there are provided a method for producing brown rice having an excellent texture and suppressing the odor peculiar to brown rice, a formed brown rice food product, and a method for producing frozen brown rice. [Brief description of the drawings]

[0011] [Figure 1] 1 is a flowchart showing the manufacturing process for brown rice of the present invention. [Diagram 2] FIG. 1 is a schematic diagram showing the structure of brown rice. [Diagram 3] 1 is a flowchart showing the manufacturing process of frozen brown rice of the present invention. [Figure 4] Photographs of the appearance of brown rice (brown rice before roasting, brown rice after roasting, and brown rice after contact with hot water). [Diagram 5] This is a summary of the sensory test questionnaire. [Figure 6] These are photographs of the appearance of frozen brown rice after freezing and frozen brown rice after thawing (microwaved and naturally thawed). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples, and can be modified as desired without departing from the gist of the present invention. In this specification, the word "to" is used as an expression including the numerical values ​​or physical quantities before and after it.

[0013] [1. Method for manufacturing brown rice] The present invention relates to a method for producing brown rice, which includes a step (1) of roasting brown rice, a step (2) of contacting the roasted brown rice with hot water, and a step (3) of cooking the brown rice after contact with the hot water to obtain brown rice (hereinafter referred to as the "method for producing brown rice of the present invention").

[0014] In addition, according to the method for producing brown rice of the present invention, the brown rice is roasted, which dries the surface of the brown rice and creates fine cracks in the surface. When the brown rice in this state is brought into contact with hot water, the inside of the brown rice (white rice layer) is more likely to absorb water, so the rice can be cooked without soaking for a long time.

[0015] Furthermore, according to the method for producing brown rice of the present invention, the roasting treatment in step (1) imparts a roasted aroma to the brown rice. Then, in step (2), the roasted brown rice is brought into contact with hot water and then cooked, thereby producing brown rice that has a suppressed odor specific to brown rice. One of the features of the method for producing brown rice of the present invention is in step (2), where the roasted brown rice is brought into contact with hot water, thereby producing brown rice with a suppressed odor specific to brown rice, compared to the case where no treatment of contacting with hot water is performed. Note that, as shown in the examples, when room temperature water is used instead of hot water in step (2), the brown rice odor is not suppressed as compared to the case where hot water is used.

[0016] Hereinafter, each step of the method for producing brown rice of the present invention will be described with reference to the flowchart shown in FIG.

[0017] As shown in Fig. 1, the method for producing brown rice of the present invention is carried out in the order of steps (1) to (3). If necessary, other steps such as a step of adding other ingredients, a molding step, etc. can be added.

[0018] <Process (1)> Step (1) is a step of roasting brown rice. By roasting brown rice, the surface of the brown rice is dried, a roasted aroma is imparted, and fine cracks are generated in the surface of the brown rice.

[0019] (brown rice) The brown rice used as the raw material for the brown rice of the present invention (hereinafter, may be referred to as "raw brown rice") is rice seed from which only the husk has been removed, and the white rice layer (endosperm) is covered from the outside with a wax layer and a bran layer (pericarp, seed coat, and aleurone layer), in that order, as shown in Figure 2. In the present invention, the epidermis of brown rice includes the wax layer and the bran layer.

[0020] The raw brown rice includes non-glutinous rice (Japonica rice, Indica rice, Javanica rice, etc.). The raw brown rice may further include other brown rice. Other examples of brown rice include colored rice (black rice, red rice, green rice, etc.), fragrant rice, etc. There are no particular limitations on the place of origin or variety of the raw brown rice.

[0021] The content of other brown rice is not particularly limited as long as it does not impair the effects of the present invention. When the raw brown rice is a mixture of non-glutinous brown rice and colored brown rice, the content of the colored brown rice is, for example, 0.5 to 1.0 parts by weight when the content of the non-glutinous brown rice is 100 parts by weight.

[0022] Furthermore, when the raw material brown rice is a mixture of non-glutinous brown rice and colored brown rice, the colored rice contained is preferably at least one type selected from black rice, red rice, and green rice. By using at least one type of colored rice selected from black rice, red rice, and green rice, brown rice containing nutrients derived from colored rice can be obtained. Examples of nutrients include anthocyanins derived from black rice, tannins derived from red rice, and chlorophyll derived from green rice. In particular, when black rice is used as the colored rice, a uniform purple color can be imparted to the brown rice after cooking.

[0023] The roasting process is a process in which the object to be roasted is heated in a dry state without using oil or water as a heat medium. The roasting process in step (1) involves placing the raw material, brown rice, in a heating container and heating it until it emits an aroma (roasted aroma). There are no limitations on the method of roasting as long as it does not impair the effects of the present invention, and a roasting method in which brown rice is placed in a heating container (frying pan, pot, etc.) and heated to a degree that does not cause the brown rice to burn is preferred.

[0024] The roasting conditions in step (1) are appropriately determined depending on the type and amount of raw brown rice, etc. The roasting is sufficient if it produces fine cracks in the brown rice epidermis so that the water absorption of the brown rice is improved, and is preferably carried out until wrinkles appear in the epidermis. Typically, the roasting temperature is 80° C. or higher and 200° C. or lower, and the roasting time is 3 to 10 minutes.

[0025] <Process (2)> Step (2) is a step of contacting the roasted brown rice with hot water. After roasting the brown rice, the brown rice is brought into contact with hot water, which allows the water to be absorbed into the inside of the brown rice (white rice layer). As a result, the brown rice can be cooked without being soaked in water for a long period of time during the subsequent cooking process (step (3)).

[0026] There are no limitations on the method for contacting brown rice with hot water as long as it does not impair the effects of the present invention, but it is preferable to contact the brown rice with hot water after roasting the brown rice and before the temperature of the heated brown rice drops (preferably immediately after roasting).

[0027] As described above, the roasting process dries the brown rice skin, causing fine cracks to form on the surface of the brown rice. By contacting the brown rice with cracks on the skin with hot water, water is more easily absorbed into the inside of the brown rice (white rice layer). The brown rice may be brought into contact with hot water by adding hot water to the brown rice, or the brown rice may be added to hot water. Alternatively, the brown rice and hot water may be stirred after contacting the brown rice with hot water.

[0028] In the present invention, "hot water" means water at 60°C or higher. By contacting roasted brown rice with hot water, brown rice can be produced with reduced odor peculiar to brown rice, as compared to the case where no treatment of contacting with hot water is performed. The upper limit of the temperature of the hot water is not particularly limited, but is usually less than 100°C under normal pressure.

[0029] In particular, when the raw brown rice is a mixture of non-glutinous brown rice and colored brown rice, in order to elute the components contained in the colored rice, the temperature of the hot water is preferably high, for example, 70°C or higher, more preferably 80°C or higher, and more preferably 90°C or higher.

[0030] The water used for the hot water is not particularly limited, and tap water, distilled water, mineral water, alkaline ionized water, etc. In addition, other additives such as salt may be added to the hot water as long as they do not impair the effects of the present invention.

[0031] The conditions in step (2) are appropriately set according to the amount and type of brown rice, the degree of roasting, etc., within a range that does not impair the effects of the present invention. It is preferable to contact the brown rice with hot water until the brown rice expands after the roasting treatment.

[0032] The amount of hot water used may be any amount that allows the brown rice to come into contact with the water in the container, and may be appropriately determined taking into consideration the amount of brown rice to be contacted.

[0033] In step (2), the contact time between the brown rice and hot water is not limited as long as the effects of the present invention are achieved, and is appropriately determined depending on the amount and type of brown rice, the temperature of the hot water, etc. For example, when the brown rice is contacted with boiling hot water, the contact time is 1 minute or more, and preferably 3 minutes or more. There is no limit to the contact time with hot water, but since too long a contact time may affect the texture and taste of the brown rice, the contact time is, for example, 20 minutes or less.

[0034] <Process (3)> Step (3) is a step of cooking the brown rice after contact with hot water to obtain brown rice. In the method for producing brown rice of the present invention, step (3) is not particularly limited as long as it does not impair the effects of the present invention. In step (3), the brown rice may be cooked by adding new water without removing the hot water that has been in contact with the brown rice, or the hot water that has been in contact with the brown rice may be removed and the brown rice may be cooked with new water.

[0035] In particular, when the raw brown rice is a mixture of non-glutinous brown rice and colored brown rice, it is preferable to cook the brown rice without removing the hot water that has come into contact with the brown rice, since the nutritional components of the non-glutinous rice and colored rice extracted with hot water can be absorbed into the brown rice and the nutritional components can be trapped inside the brown rice during cooking.

[0036] The rice cooking method in the present invention can be a conventionally known method as long as the effects of the present invention are not impaired and the brown rice is cooked to the desired hardness.

[0037] Brown rice is usually covered with an outer layer (wax and bran layers), which makes it difficult for water to penetrate into the inside of the rice (the white rice layer), making cooking brown rice difficult. In order to allow water to penetrate into the inside of the brown rice (white rice layer), the usual method of cooking brown rice requires that the brown rice be soaked in water for a long period of time and cooked using a pressure cooker or the like. However, the method for producing brown rice of the present invention has the advantage that, by carrying out steps (1) and (2), the brown rice after hot water treatment can be cooked immediately without soaking, and can be cooked under the same conditions as regular white rice.

[0038] In step (3), the brown rice after the hot water treatment may be cooked immediately without soaking in water, or may be soaked in water separately. Even if soaking is performed, it is preferable to soak the raw brown rice for a shorter period of time than usual (for example, about 1 to 3 hours) because the raw brown rice has already absorbed water by performing steps (1) and (2). Furthermore, the rice cooking in step (3) is usually carried out under normal pressure, but can be carried out under pressurized conditions (for example, using a pressure cooker) as necessary, provided that the effects of the present invention are not impaired.

[0039] (Other processes) Furthermore, the method for producing brown rice of the present invention may include other steps, as necessary, in addition to the above-mentioned steps (steps (1) to (3)) as long as the object of the present invention is not impaired. Examples of other steps include a step of forming the brown rice into a predetermined shape, a step of adding other ingredients, etc.

[0040] In addition, a step of adding other ingredients can be carried out as long as it does not impair the effects of the present invention. The timing of adding other ingredients is not particularly limited, and they may be added during each step (step (1) to step (3)) or to brown rice after cooking. The other ingredients are not particularly limited as long as they are raw materials normally used in the manufacture of processed foods, but for example, grains other than brown rice, other food ingredients, optional additive ingredients, etc. may be added. Optional additive ingredients include seasonings, flavorings, emulsifiers, preservatives, antioxidants, thickeners, colorants, etc.

[0041] The other materials may be used alone or in combination of two or more. The content of the other materials is not particularly limited as long as it does not impair the effects of the present invention, and is appropriately set depending on the type of material to be used.

[0042] The brown rice of the present invention is brown rice produced by the above-mentioned method for producing brown rice of the present invention. The produced brown rice leaves no fibrous residue after eating, has an excellent texture, and has a suppressed odor peculiar to brown rice.

[0043] The produced brown rice may be molded into a predetermined shape to produce a molded brown rice food. Normally, when brown rice is cooked in the same way as white rice, it becomes floppy and difficult to shape, but according to the method for producing brown rice of the present invention, the brown rice after cooking is sticky and does not become floppy, making it easy to shape.

[0044] The produced brown rice can be molded into a predetermined shape to produce the brown rice molded food product of the present invention. The shape to be molded is not particularly limited, and examples thereof include a triangular prism, a cylinder, a rectangular parallelepiped, a sphere, an oval sphere, a bale, etc. The molding of the brown rice can be carried out using a mold having a desired shape.

[0045] The brown rice molded food product can be made by molding the brown rice produced by the brown rice manufacturing method of the present invention into a predetermined shape, and examples of the molded food include rice balls, rolled sushi, inari sushi, etc. Among these, rice balls are preferable. In addition, by filling the brown rice molded food into a container, a brown rice pack can be made.

[0046] [2. Method for producing frozen brown rice] The present invention relates to a method for producing frozen brown rice, which includes a step (1) of roasting brown rice, a step (2) of contacting the roasted brown rice with hot water, a step (3) of cooking the brown rice after contact with the hot water to obtain brown rice, and a step (4) of freezing the obtained brown rice to obtain frozen brown rice (hereinafter referred to as the "method for producing frozen brown rice of the present invention"). The steps (1) to (3) in the method for producing frozen brown rice of the present invention are the same as the method for producing brown rice of the present invention described above.

[0047] Hereinafter, each step of the method for producing frozen brown rice of the present invention will be described with reference to the flowchart shown in FIG.

[0048] As shown in FIG. 3, the method for producing frozen brown rice of the present invention further includes a freezing step (step (4)) in addition to the above-mentioned steps (1) to (3). In the method for producing frozen brown rice of the present invention, the raw material brown rice, steps (1) to (3), and other steps are as described above, so description thereof will be omitted.

[0049] Step (4) is a step of freezing the brown rice obtained after the rice cooking step. When producing shaped frozen brown rice, it is preferable to freeze the brown rice obtained in step (3) after forming it into a predetermined shape in step (4).

[0050] Even when the frozen brown rice obtained in step (4) is thawed, no fibrous material remains after eating, similar to brown rice immediately after cooking, and the texture is excellent and the odor peculiar to brown rice is suppressed.

[0051] The freezing temperature in step (4) may be 0° C. or lower, preferably −10° C. or lower, and more preferably −15° C. or lower. There is no particular lower limit to the freezing temperature, but since thawing requires extra energy and time, it is usually −25° C. or higher. The freezing time may be any length as long as it does not impair the object of the present invention.

[0052] In step (4), the method for freezing the brown rice is not particularly limited, and any freezing method commonly used for food products can be used. As a means for freezing, any suitable means can be selected as long as it is possible to adjust the freezing temperature, and for example, a commercially available freezer can be used. A large, equipped freezing facility can also be used.

[0053] The freezing in step (4) may be rapid freezing or slow freezing as long as it does not impair the effects of the present invention, but rapid freezing is preferred. In this specification, slow freezing refers to freezing at a slow cooling rate using commercially available freezing equipment, and is a freezing method in which the material passes gently through the temperature range of maximum ice crystal formation (-1°C to -5°C). In this specification, quick freezing means a freezing process at a rapid cooling rate, and is a freezing method in which the material passes quickly through the temperature range of maximum ice crystal formation (-1°C to -5°C). Quick freezing is performed to cool the material to the desired temperature within at least 30 minutes (preferably within 10 minutes), depending on the amount of material to be cooled.

[0054] In step (4), by quickly freezing the brown rice, it is possible to quickly pass through the temperature range of -1°C to -5°C and suppress the formation of ice crystals in the frozen object (brown rice), so that the rapid-frozen frozen brown rice can suppress deterioration in texture after thawing. When rapid freezing is performed, the brown rice may be once frozen by rapid freezing and then stored under normal freezing conditions.

[0055] The device for performing the quick freezing is not particularly limited, but it is preferable to freeze the brown rice using a quick freezing machine, since this has good productivity and can perform quick freezing in a short time. Examples of quick freezers include the 3D freezer method, which uses high-humidity cold air produced by non-throughflow heat exchange, and the method of quickly freezing an object to be cooled by immersing it in a tank containing a refrigerant liquid (including liquid nitrogen freezing).

[0056] Alternatively, in step (4), freezing may be performed by applying a uniform magnetic flux and electromagnetic waves. By applying a uniform magnetic flux (static magnetic field) to the frozen brown rice, which is the object to be frozen, and applying electromagnetic waves to freeze the rice while irradiating the rice with electromagnetic waves in a predetermined direction, it is possible to more effectively suppress the coarsening of ice crystals during freezing, the destruction of the cells of the brown rice containing moisture, and dripping due to thawing, even at about -18°C (the same temperature as that of a normal commercially available freezer), and it is possible to more reliably maintain the taste and texture of the frozen object (brown rice) after thawing.

[0057] As a freezing device that applies uniform magnetic flux and electromagnetic waves to freeze, a proton freezer commercially available from Ryoho Freeze Systems Co., Ltd. can be suitably used. The details of this refrigeration device are as described in Japanese Patent No. 4424693, but briefly, the refrigeration device is characterized by comprising a refrigeration device core unit comprising: a substantially rectangular first plate-shaped member and a substantially rectangular second plate-shaped member arranged parallel to each other and facing each other with a gap; a radio wave transmission antenna provided between a first side of the first plate-shaped member and a first side of the second plate-shaped member so as to transmit radio waves to the first plate-shaped member and the second plate-shaped member; a first magnet body provided on the second plate-shaped member side of the first plate-shaped member, and a second magnet body provided on the first plate-shaped member side of the second plate-shaped member; and a unidirectional and substantially uniform static magnetic field is formed between the first plate-shaped member and the second plate-shaped member in a substantially normal direction to the main surface of the first plate-shaped member and the main surface of the second plate-shaped member, and a freezer that houses the core unit. In this refrigeration device, a target can be frozen while irradiating a static magnetic field and radio waves in a predetermined direction.

[0058] The frozen brown rice of the present invention is the frozen brown rice produced by the above-mentioned method for producing frozen brown rice of the present invention. By freezing the brown rice, it is possible to store the brown rice for a long period of time.

[0059] The frozen brown rice produced by the method for producing frozen brown rice of the present invention can be thawed and eaten. The thawing method is not particularly limited as long as it does not impair the effects of the present invention, and examples of the thawing method include natural thawing at room temperature (25°C), thawing at refrigeration temperature, and microwave heating.

[0060] The frozen brown rice of the present invention is excellent in taste, texture, etc. after thawing. In particular, the quick-frozen frozen brown rice is prevented from losing texture after thawing, and has the same taste and texture as unfrozen brown rice. EXAMPLES

[0061] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0062] [1. Brown rice] [1-1. Method for producing brown rice] The brown rice of Example 1, Comparative Example 1, Comparative Example 2, and Reference Example was produced by the following method.

[0063] <Example 1> (Process (1)) The raw brown rice (a mixture of non-glutinous brown rice and black rice) was placed in a pot and roasted over low heat with stirring until the roasted aroma of brown rice was released. (Process (2)) Then, 80 parts by weight of boiling hot water was added per 100 parts by weight of the roasted brown rice to the pot containing the roasted brown rice, and the roasted brown rice was allowed to come into contact with the hot water for 5 minutes. (Step (3)) After step (2), the brown rice after contact with hot water and the hot water were transferred to a pressure cooker, and then 107 parts by weight of room temperature water (about 25°C) per 100 parts by weight of brown rice (brown rice after roasting treatment) was added to the pressure cooker containing the brown rice after contact with hot water and the hot water, and the brown rice of Example 1 was obtained by cooking for 25 minutes without soaking.

[0064] <Comparative Example 1> Unroasted raw brown rice (a mixture of non-glutinous brown rice and black brown rice) was placed in a pressure cooker, and 187 parts by weight of room temperature water was added per 100 parts by weight of the brown rice. The brown rice of Comparative Example 1 was obtained by cooking for 25 minutes without soaking.

[0065] <Comparative Example 2> Brown rice of Comparative Example 2 was obtained by the same production method as in Example 1, except that in step (2) of Example 1, room temperature water was used instead of hot water.

[0066] <Reference example> The raw brown rice (a mixture of non-glutinous brown rice and black rice brown rice) was placed in a pressure cooker, and 187 parts by weight of room temperature water was added for every 100 parts by weight of the brown rice.The brown rice was soaked for 6 hours, and then cooked for 25 minutes to obtain the reference brown rice.

[0067] [1-2. Evaluation of brown rice (appearance observation and sensory evaluation of brown rice)] In Example 1, several pieces of brown rice were taken out after step (1) and step (2) and the state of the brown rice was observed. Figure 4 shows an external photograph of the state of the brown rice. As shown in Figure 4, compared with the brown rice before the roasting treatment (left side of Figure 4), it was confirmed that wrinkles were generated on the surface of the brown rice after the roasting treatment (center of Figure 4). Furthermore, after coming into contact with hot water (right side of Figure 4), no wrinkles were observed on the surface of the brown rice, and the brown rice was confirmed to have expanded.

[0068] Furthermore, when the lid of the pressure cooker was opened after step (3), the brown rice of Example 1 had almost no odor characteristic of brown rice. However, the brown rice of Comparative Example 1, Comparative Example 2, and Reference Example had an odor characteristic of brown rice.

[0069] Furthermore, when the brown rice of Example 1, Comparative Example 1, Comparative Example 2, and Reference Example were eaten, the brown rice of Comparative Example 1, Comparative Example 2, and Reference Example had an odor unique to brown rice, whereas the brown rice of Example 1 had almost no odor unique to brown rice. In terms of texture, the brown rice of Example 1 was particularly excellent, with no fibrous material remaining on the tongue and a good texture. Moreover, the taste of the brown rice of Example 1, Comparative Example 1, and Comparative Example 2 was approximately the same as that of the brown rice of the Reference Example.

[0070] [2. Frozen brown rice] [2-1. Method for producing frozen brown rice 1] Brown rice molded foods were produced from the brown rice of Example 1 (roasted brown rice brought into contact with hot water and then cooked), Comparative Example 1 (unroasted brown rice cooked without soaking), and Reference Example (unroasted brown rice soaked for 6 hours and then cooked) produced in the above [1-1. Manufacturing method for brown rice], and frozen brown rice was produced by slow-freezing in the following manner.

[0071] <Freezing method A: Slow freezing> The produced brown rice was formed into a triangular shape (rice ball shape), and the formed brown rice food product was then slowly frozen in a commercially available freezer (approximately -18°C) for 10 hours to obtain frozen brown rice.

[0072] The frozen brown rice produced by the above method was thawed by the following thawing method.

[0073] (Defrosting method 1: Microwave) The obtained frozen brown rice was thawed by heating for 1 minute and 30 seconds in a 600 watt household microwave oven. (Thaw method 2: Natural thaw) The obtained frozen brown rice was left to stand at room temperature (25°C) for 3 hours and thawed by natural thawing.

[0074] [2-2. Evaluation of thawed frozen brown rice (sensory test)] Panelists (four men and women in their 30s to 40s) ate the thawed frozen brown rice and conducted a sensory test on the smell and texture. For the evaluation, frozen brown rice produced by freezing method A was thawed by thawing method 1 (microwave-reheating) (hereinafter referred to as "Example 1A", "Comparative Example 1A", and "Reference Example A", respectively). The thawed frozen brown rice was subjected to a sensory test (smell, texture) and evaluated according to the following evaluation criteria. The summary of the evaluation test questionnaire on which Table 1 was based is shown in Figure 5.

[0075] (Evaluation criteria: Smell (the distinctive smell of brown rice)) 1 point: Almost no odor characteristic of brown rice. 0 points: Has a distinctive brown rice smell. -1 point: Strong smell unique to brown rice.

[0076] (Evaluation criteria: texture) 1 point: Better texture than reference example A. 0 points: The texture is the same as that of Reference Example A. -1 point: The texture is slightly inferior to that of Reference Example A.

[0077] Table 1 shows the evaluation results, which show the average scores of the panelists.

[0078] [Table 1]

[0079] As shown in Table 1, when thawed frozen brown rice (Example 1A, Comparative Example 1A, and Reference Example A) was eaten, the brown rice had almost no odor characteristic of brown rice in Example 1A, but the Reference Example A had an odor characteristic of brown rice, and the Comparative Example 1A had a strong odor characteristic of brown rice. Furthermore, the texture of Comparative Example 1A was equal to or better than that of Reference Example A. In contrast, Example 1A had a superior texture to that of Reference Example A.

[0080] In addition, brown rice molded foods were produced by molding the brown rice of Example 1 and Comparative Example 1, and the frozen brown rice that had been slowly frozen and thawed using thawing method 2 (natural thawing) was eaten.The results were similar to those of the brown rice molded foods thawed by reheating in the microwave as described above.

[0081] [2-3. Method for producing frozen brown rice 2] The brown rice produced in Example 1 (roasted brown rice brought into contact with hot water and then cooked) as described in [1-1. Method for producing brown rice] above was molded into a brown rice molded food product, and frozen brown rice was produced by irradiating it with a static magnetic field and radio waves in a specified direction and freezing it using the following method.

[0082] <Freezing method B: Static magnetic field and radio wave irradiation freezing> The produced brown rice was formed into a triangular shape (rice ball shape), and the formed brown rice food product was then frozen to -18°C using a proton freezer (Rishitoyo Freeze Systems Co., Ltd.) while irradiating it with a static magnetic field and radio waves in a specified direction, and then kept in that state to obtain frozen brown rice (total freezing time: 30 minutes).

[0083] The frozen brown rice produced by the above method was thawed by the following thawing method.

[0084] (Defrosting method 1: Microwave) The obtained frozen brown rice was thawed by heating for 1 minute and 30 seconds in a 600 watt household microwave oven. (Thaw method 2: Natural thaw) The obtained frozen brown rice was left to stand at room temperature (25°C) for 3 hours and thawed by natural thawing.

[0085] [2-4. Evaluation of frozen brown rice after thawing (visual observation and sensory evaluation)] FIG. 6 shows photographs of the appearance of frozen brown rice produced by freezing the brown rice food product produced by molding the brown rice of Example 1 using freezing method B, and the frozen brown rice after thawing (microwaved and naturally thawed). As shown in Figure 6, no frost or ice crystals were observed on the surface of the frozen brown rice after freezing using freezing method B (top of Figure 6), and no change in appearance due to the difference in thawing method was observed (center and bottom of Figure 6). In addition, when frozen brown rice thawed using each of the thawing methods was eaten, the texture and flavor were not compromised by any of the thawing methods, and the odor peculiar to brown rice was hardly noticeable. [Industrial Applicability]

[0086] According to the present invention, it is possible to provide a method for producing brown rice having an excellent texture and suppressing the odor peculiar to brown rice, a formed brown rice food product, and a method for producing frozen brown rice.

Claims

1. A step (1) of heating and roasting brown rice until fine cracks are formed on the surface of the rice; (2) contacting the roasted brown rice with hot water of 60°C or higher; (3) cooking the brown rice after contact with hot water to obtain brown rice; having A method for producing brown rice, characterized in that the brown rice is a mixture of non-glutinous brown rice and colored brown rice (excluding the case where, in step (3), white rice or glutinous rice is cooked together with the brown rice after contact with hot water).

2. A method for producing brown rice as described in claim 1, wherein in step (3), the brown rice is cooked without removing the hot water that has come into contact with the brown rice.

3. 2. The method for producing brown rice according to claim 1, wherein the colored rice is at least one type selected from black rice, red rice, and green rice.

4. A shaped brown rice food product obtained by shaping brown rice obtained by the manufacturing method according to any one of claims 1 to 3.

5. A step (1) of heating and roasting brown rice until fine cracks are formed on the surface of the rice; (2) contacting the roasted brown rice with hot water of 60°C or higher; (3) cooking the brown rice after contact with hot water to obtain brown rice; A step (4) of freezing the obtained brown rice to obtain frozen brown rice; having A method for producing frozen brown rice, wherein the brown rice is a mixture of non-glutinous brown rice and colored brown rice (excluding the case where, in step (3), white rice or glutinous rice is cooked together with the brown rice after contact with hot water).

6. A method for producing brown rice as described in claim 5, wherein in step (3), the brown rice is cooked without removing the hot water that has come into contact with the brown rice.

7. The method for producing frozen brown rice according to claim 5, wherein the colored rice is at least one type selected from black rice, red rice, and green rice.

8. The method for producing frozen brown rice according to any one of claims 5 to 7, wherein in step (4), the brown rice is formed into a predetermined shape and then frozen.

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