Method for producing rice dish, method for softening rice dish, and composition for cooking rice

Abstract

The present invention addresses the problem of providing a method for producing a rice dish, the method being capable of producing a rice dish having a favorable soft food texture even when cooked rice or a rice dish including cooked rice is stored. Moreover, provided is a method for softening a rice dish even when cooked rice or a rice dish including cooked rice is stored. Furthermore, provided is a composition for cooking rice, the composition being capable of softening a rice dish even when cooked rice or a rice dish including cooked rice is stored.　The present invention provides the following. This method for producing a rice dish comprises adding oil and fat and an enzyme to cook cooked rice or a rice dish including cooked rice. Moreover, it is preferable to add the oil and fat so that the amount of the oil and fat is 0.1-5 g per 100 g of raw grains before cooking rice, and to add the enzyme so that the enzyme activity is at least 0.50 U per 100 g of raw grains before cooking rice.

Description

Method for producing rice, method for softening rice, and composition for cooking rice

[0001] The present invention relates to a method for producing cooked rice, a method for softening cooked rice, and a composition for cooking rice.

[0002] Although rice dishes are eaten in various forms, such as white rice, fried rice, seasoned rice, and porridge, there is a demand for controlling the texture, and in recent years, some users prefer soft rice because it is easier to eat. Furthermore, from the perspective of food waste, there is a demand for maintaining the taste and texture of foods, and for example, a proposal has been made to improve the texture of cooked rice foods using an enzyme preparation containing a branching enzyme and α-glucosidase (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2018-139596

[0004] However, although Patent Document 1 discloses cooked rice with a soft texture, it is not sufficient.

[0005] Therefore, an object of the present invention is to provide a method for producing cooked rice that provides cooked rice or cooked rice-containing rice with a good soft texture even after storage.An object of the present invention is also to provide a method for softening cooked rice or cooked rice-containing rice even after storage.An object of the present invention is also to provide a rice-cooking composition that can soften cooked rice or cooked rice-containing rice even after storage.

[0006] As a result of extensive research, the present inventors discovered that the hardness of cooked rice can be controlled by using fats and oils and enzymes, and thus completed the present invention.

[0007] That is, the present invention provides the following [1] to [8]. [1] A method for producing cooked rice, comprising the step of adding oil and an enzyme and cooking cooked rice or a cooked rice-containing rice product. [2] A method for producing cooked rice according to [1] above, comprising adding the oil so that the amount of oil is 0.1 to 5 g per 100 g of raw grain before cooking, and adding the enzyme so that the enzyme activity is 0.50 U or more per 100 g of raw grain before cooking. [3] A method for producing cooked rice according to [1] above, further comprising adding an emulsifier and cooking the rice, the amount of emulsifier being 0.1 to 9 parts by mass per 100 parts by mass of oil and fat. [4] The method for producing cooked rice according to any of [1] to [3] above, wherein the enzyme is one or more selected from amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase, and pectinase, and the enzyme is added so that the enzyme activity is 0.50 to 50,000.00 U per 100 g of raw grain before cooking. [5] A method for softening cooked rice by adding an oil or fat and an enzyme in the step of cooking cooked rice or cooked rice-containing rice. [6] The method for softening cooked rice according to [5] above, wherein the oil or fat is added so that the amount of oil or fat is 0.1 to 5 g per 100 g of raw grain before cooking, and the enzyme is added so that the enzyme activity is 0.50 U or more per 100 g of raw grain before cooking. [7] The method for softening cooked rice according to [5] or [6], wherein in the step of cooking cooked rice or cooked rice-containing rice products, an emulsifier is further added in an amount of 0.1 to 9 parts by mass per 100 parts by mass of fat or oil, the enzyme is one or more selected from amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase, and pectinase, and the enzyme is added so that the enzyme activity is 0.50 to 50,000.00 U per 100 g of raw grain before cooking. [8] A rice-cooking composition used in the method for producing cooked rice according to any of [1] to [3], comprising fat or oil and an enzyme, and containing the enzyme so that the enzyme activity is 0.50 U or more per 0.1 to 5.0 g of fat or oil.[9] The rice cooking composition according to [8], which contains 0.1 to 9 parts by mass of an emulsifier per 100 parts by mass of fats and oils, wherein the enzyme is one or more selected from amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase, and pectinase, and the amount of the enzyme is an amount that results in an enzyme activity of 0.50 to 50,000.00 U per 100 g of raw grain before cooking.

[0008] According to the present invention, cooked rice can be stored with a sufficiently soft texture, and compared to cooked rice that does not use the oil and fat composition for rice cooking of the present invention, deterioration of the cooked rice after storage can be suppressed, allowing the period during which the cooked rice can be enjoyed or the expiration date to be set longer, thereby realizing a reduction in food waste.

[0009] The present invention will be described in detail below. In the embodiments of the present invention, A (numerical value) to B (numerical value) means A or more and B or less. The preferred and more preferred embodiments exemplified below can be used in appropriate combinations, regardless of expressions such as "for example," "preferred," and "more preferred." Numerical ranges are merely examples, and ranges obtained by appropriately combining the upper and lower limits of each range and the numerical values ​​of the examples can also be used (for example, when A to B or C to D is stated, the combinations A to D or C to B can be used). Furthermore, terms such as "contain" or "comprise" may be interpreted as "essentially consisting of" or "consisting only of."

[0010] [Method for Producing Cooked Rice] In the method for producing cooked rice of the present invention, oil and fat and an enzyme are added, and cooked rice or a cooked rice-containing rice is cooked. In the present invention, the texture of the cooked rice becomes soft due to the synergistic effect of the oil and fat and the enzyme described below.

[0011] <Raw Grains> In the present invention, raw grains are cooked to produce cooked rice or rice dishes containing cooked rice. Well-known raw grains such as rice, millet, barnyard millet, quinoa, and wheat can be used as raw grains. The type and origin of the raw rice are not particularly limited. For example, not only japonica rice, indica rice, and javanica rice, but also hybrid varieties thereof can be used. Furthermore, the degree of polishing of the raw rice is not particularly limited. In addition to white rice, brown rice, half-polished rice, germinated brown rice, and no-wash rice can also be used in this embodiment. In the present invention, "100 g of raw grains before cooking" refers to 100 g of raw grains before they absorb water during cooking.

[0012] <Rice Cooking> In the present invention, oils and enzymes are added and cooked rice or rice products containing cooked rice are cooked. The order of adding raw grains, water, oils and enzymes is not particularly limited. Stirring after addition is acceptable, but it is preferable not to stir because this may damage the raw grains. Note that the amount of water, heating temperature, heating time, etc. during cooking can be the same as for regular rice cooking.

[0013] <Oils and Fats> Conventional edible oils and fats can be used in the method for producing rice of the present invention. Examples of edible oils and fats that can be used include animal and vegetable oils, microbial oils, oils synthesized from glycerin and fatty acids, and their fractionated oils, interesterified oils, and hydrogenated oils, either alone or in combination. Examples of animal and vegetable oils and fats include soybean oil, rapeseed oil, sunflower oil, olive oil, safflower oil, corn oil, cottonseed oil, rice oil, sesame oil, perilla oil, linseed oil, peanut oil, grapeseed oil, beef tallow, milk fat, fish oil, coconut oil, palm oil, and palm kernel oil. Fractionated oils from these oils (e.g., fractionated palm oils such as palm olein, palm superolein, palm stearin, and palm midfraction) can also be used. The vegetable oil may be obtained from a plant variety having a high or low content of a specific fatty acid (e.g., canola oil, high oleic canola oil, high oleic soybean oil, vegetable oil rich in n-3 fatty acids, high oleic palm oil, etc.). Microbial oils include oils produced by microorganisms such as yeast and algae. Examples of oils synthesized from glycerin and fatty acids include oils containing linear saturated fatty acids having 6 to 12 carbon atoms, preferably 8 to 10 carbon atoms, such as medium-chain triglycerides (MCTs) having 8 to 10 carbon atoms. Interesterified oils are oils obtained by interesterification of oils and fats as raw materials. For example, interesterified oils of palm oil or fractionated palm oil with other liquid oils, or interesterified oils of MCT with vegetable oil, etc., can be used. Examples of hydrogenated oils and fats include hydrogenated animal and vegetable oils, fractionated animal and vegetable oils, and hydrogenated interesterified oils and fats.

[0014] The edible oils and fats may be unrefined or refined. The refined oils and fats may be those that have undergone one or more refining steps, such as a degumming step, a deacidification step, a bleaching step, a deodorization step, or a dewaxing step. Preferably, the deodorization step is followed by a degumming step, a deacidification step, or a bleaching step. Unrefined oils and fats are those that have not undergone the above-mentioned refining steps. Examples of unrefined oils and fats include virgin oils characterized by a flavor derived from raw materials such as olive oil and camellia oil, as well as roasted oils and fats characterized by a roasted flavor, such as roasted sesame oil, roasted rapeseed oil, and roasted peanut oil. The unrefined oil may also be virgin oil or roasted oil that has undergone one or more steps selected from a step of removing solids by filtration, settling separation, centrifugation, or the like, a water washing step, and a drying step.

[0015] In the present invention, it is preferable to add oil so that the amount of oil is 0.1 to 5 g per 100 g of raw grain before cooking. The oil can be added before or during cooking, but is preferably added before cooking. Furthermore, convection occurs during cooking, and a certain degree of dispersion can be expected, but it is also possible to mix the oil and fat, or to add an emulsifier as described below to improve dispersibility. The amount of oil and fat added is preferably 0.2 to 2 g, more preferably 0.5 to 1.5 g, per 1 g of raw grain before cooking.

[0016] <Emulsifier> In the present invention, the inclusion of an emulsifier together with the oil or fat further softens the texture of rice. The emulsifier can be one or more selected from polyglycerol fatty acid esters, polyglycerol condensed ricinoleate esters, sucrose fatty acid esters, monoglycerol fatty acid esters, organic acid monoglycerides, sorbitan fatty acid esters, propylene glycol fatty acid esters, polysorbates, lecithin, etc. Preferably, the emulsifier is one or more selected from polyglycerol fatty acid esters, polyglycerol condensed ricinoleate esters, and organic acid monoglycerides. Furthermore, the polyglycerol fatty acid esters and polyglycerol condensed ricinoleate esters used have an average degree of polymerization of the polyglycerol moiety of 2 to 12, preferably 4 to 10.

[0017] The addition of an emulsifier is preferred because it is expected to improve the solubility in oils and fats, dispersibility of oils and fats in water, and the like, in addition to the effect of softening the texture of rice. In this case, it is preferable to use an emulsifier with an HLB of 3 to 10. More preferably, it is an emulsifier with an HLB of 4 to 8. Furthermore, in order to prevent crystallization in oils and fats, it is preferable that the constituent fatty acids of the emulsifier contain a large amount of unsaturated fatty acids, and it is preferable that 50% by mass or more of the constituent fatty acids of the emulsifier are unsaturated fatty acids. It is particularly preferable that oleic acid accounts for 50% by mass or more of the constituent fatty acids of the emulsifier. Furthermore, polyglycerin fatty acid esters are more preferred.

[0018] HLB is an abbreviation for Hydrophile Lipophile Balance, and is an index used to determine whether an emulsifier is hydrophilic or lipophilic, taking on a value of 0 to 20. The smaller the HLB value, the stronger the lipophilicity. In the present invention, the HLB value is calculated using the Atlas method. The Atlas method is a method of calculating the HLB value from the following equation: HLB = 20 x (1 - S / A), where S is the saponification value and A is the neutralization value of the fatty acid in the ester. Hereinafter, the term HLB in this specification refers to the HLB calculated using the Atlas method.

[0019] In the present invention, the amount of emulsifier added is preferably 0.1 to 9 parts by mass per 100 parts by mass of oils and fats. Within this range, the texture of cooked rice becomes even softer due to the synergistic effect of the aforementioned oils and fats and the enzymes described below. The emulsifier can be added before or during cooking, but is preferably added before cooking. The amount of emulsifier added is more preferably 0.2 to 5 parts by mass, even more preferably 0.5 to 3 parts by mass, and most preferably 0.8 to 2 parts by mass per 100 parts by mass of oils and fats.

[0020] <Enzymes> The enzymes used in the method for producing rice of the present invention may be any enzymes that have been used as conventional means for preventing aging. For example, one or more of amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase, pectinase, etc. may be used. Preferably, one or more enzymes selected from amylase, glucanotransferase, and pectinase are used, and particularly preferably, one or more enzymes selected from α-amylase, 4-α-glucanotransferase, and pectinase are used. Preferably, the enzyme used in the method for producing rice of the present invention is an enzyme with α-amylase activity (an enzyme capable of hydrolyzing the α-1,4 glycosidic bond in polysaccharides).

[0021] The enzymes may be added to the soaking liquid in which the raw grain material is soaked to absorb water, or may be added after soaking and before cooking.

[0022] In the present invention, the coexistence of an enzyme with fats and oils softens the texture of rice. It is preferable to add the enzyme so that the enzyme activity per 100 g of raw grain before cooking is 0.50 U or more. The enzyme activity per 100 g of raw grain before cooking when the enzyme is added is preferably 0.50 to 50,000.00 U, more preferably 0.70 to 10,000.00 U, even more preferably 1.00 to 5,000.00 U, and most preferably 1.00 to 1,000.00 U. Here, the enzyme activity (U) refers to the enzyme titer (amount of enzyme) involved in the reaction of the enzyme with the substrate. In the present invention, one unit (U) is defined as the amount of enzyme that catalyzes the conversion of 1 μmol of substrate per minute under optimal conditions (30°C) according to the definition by the International Union of Biochemistry and Molecular Biology (IUBMB). The enzyme activity in the present invention is α-amylase activity. The α-amylase activity can be determined by a conventional method, but a commercially available assay kit may also be used, for example, the "α-amylase activity assay kit" manufactured by Kikkoman Biochemifa Corporation.

[0023] <Other Ingredients> In the method for producing cooked rice of the present invention, in addition to the ingredients described above, commonly used ingredients can be used during cooking. Specifically, for example, pH adjusters, seasonings, coloring agents, flavorings, antioxidants, sugars, sugar alcohols, stabilizers, water, alcohol, etc. can be used. The amounts of these ingredients can be any amount as long as they do not impair the effects of this embodiment.

[0024] [Method for softening cooked rice] In the method for softening cooked rice of the present invention, oils and fats and enzymes are added in the process of cooking cooked rice or cooked rice-containing rice. It is also preferable that an emulsifier is added. Details are as described in the above-mentioned [Method for producing cooked rice].

[0025] [Rice Cooking Composition] The rice cooking composition of the present invention is a rice cooking composition used in the aforementioned [Method for Producing Rice], and contains fats and oils and an enzyme, and the enzyme is contained so that the enzyme activity is 0.50 U or more per 0.1 to 5.0 g of fats and oils. It also preferably contains an emulsifier. Details are as described in the aforementioned [Method for Producing Rice].

[0026] Next, the present embodiment will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, "%" indicates % by mass unless otherwise specified.

[0027] <Production of Compositions> Compositions 1 to 11 were prepared by mixing according to the formulations shown in Tables 1 to 3. The raw materials used are as follows: Oil: rapeseed salad oil Enzyme preparation-1: Sensea Rice MA L (manufactured by Novozymes Japan Co., Ltd., maltose-producing α-amylase, titer (enzyme activity): 163 U / g) Enzyme preparation-2: Glycotransferase "Amano" (manufactured by Amano Enzyme Inc., 4-α-glucanotransferase, titer: 343 U / g) Enzyme preparation-3: Sucrase N (manufactured by Mitsubishi Chemical Corporation, pectinase, titer: 79 U / g) Emulsifier-1: Polyglycerol fatty acid ester: Poem DO-100V (manufactured by Riken Vitamin Co., Ltd., diglycerol monooleate, HLB 7) Emulsifier-2: Sunsoft No. 818JC (Taiyo Kagaku Co., Ltd., triglycerin condensed ricinoleic acid ester) Emulsifier-3: Polyglycerin fatty acid ester: Ryoto Polyglycerol O-50D (Mitsubishi Chemical Corporation, decaglycerin pentaoleic acid ester, HLB 7) The potency (enzyme activity) of enzyme preparations-1 to -3 is the potency as α-amylase, and was measured using an α-amylase activity measurement kit (Kikkoman Biochemifa Corporation).

[0028] <Production of Rice Dishes (Rice Cooking)> After 1.4 times the mass of water was added to polished rice and the rice was soaked for 1 hour, Compositions 1 to 11 were added at the blending amounts (g) shown in Tables 1 to 3 per 100 g of polished rice, and the mixture was thoroughly stirred. The rice was then cooked in an electric rice cooker (SR-FC107, manufactured by Panasonic Corporation). After cooking, the cooked rice was transferred to a tray, lightly loosened, and vacuum cooled at 30°C to produce the cooked rice of Comparative Examples 1 to 5 and Examples 1 to 6.

[0029] <Storage Test> Cooked rice cooled to 30°C was stored at 10°C for one day.

[0030] <Sensory evaluation> Cooked rice before storage and after one day of storage was left at room temperature for 15 minutes, and then evaluated by five expert panelists using the following evaluation criteria (discussion among the five panelists). The evaluation results are shown in Tables 1 to 3. 4: All panelists rated it as soft 3: 3-4 panelists rated it as soft 2: 1-2 panelists rated it as soft 1: All panelists rated it as hard

[0031] <Stickiness value, hardness value> Stickiness was measured using a Tensipressor Lite (manufactured by Taketomo Electric Co., Ltd.). 10 g of the resulting cooked rice was packed into the included petri dish (Φ: 42 mm) and molded using the included cooked rice molding tool. Measurements were performed using the included cylindrical probe (contact area 2.5 cm2) and the "Cooked Rice 2 x 3 Measurement Analysis" program. The "hardness" value was shown from the measurement results. The value is the average of four measurements. Note that the higher the hardness (hardness value) number, the harder the rice, and the lower the number, the softer the rice.

[0032]

[0033]

[0034]

[0035] As is clear from the results in Tables 1 to 3, Examples 1 to 6 have a soft texture and the hardness values ​​after storage are lower than those of Comparative Examples 1 to 5, which is good.

Claims

1. A method for producing cooked rice, comprising the step of adding oil and fat and enzymes and cooking cooked rice or cooked rice-containing rice.

2. The method for producing cooked rice according to claim 1, wherein the oil is added so that the amount of oil is 0.1 to 5 g per 100 g of raw grain before cooking, and the enzyme is added so that the enzyme activity is 0.50 U or more per 100 g of raw grain before cooking.

3. The method for producing cooked rice according to claim 1, further comprising adding an emulsifier and cooking the rice, the amount of the emulsifier being 0.1 to 9 parts by mass per 100 parts by mass of oil or fat.

4. The method for producing cooked rice according to any one of claims 1 to 3, wherein the enzyme is one or more selected from amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase, and pectinase, and the enzyme is added so that the enzyme activity is 0.50 to 50,000.00 U per 100 g of raw grain before cooking.

5. A method of softening cooked rice or other cooked rice-containing foods by adding fats and oils and enzymes during the cooking process.

6. The method for softening cooked rice according to claim 5, wherein the oil is added so that the amount of oil is 0.1 to 5 g per 100 g of raw grains before cooking, and the enzyme is added so that the enzyme activity is 0.50 U or more per 100 g of raw grains before cooking.

7. A method for softening cooked rice according to claim 5 or 6, wherein in the step of cooking cooked rice or cooked rice-containing rice, an emulsifier is further added, the amount of emulsifier being 0.1 to 9 parts by mass per 100 parts by mass of fats and oils, the enzyme is one or more selected from amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase and pectinase, and the enzyme is added so that the enzyme activity is 0.50 to 50,000.00 U per 100 g of raw grain before cooking.

8. A rice-cooking composition used in the method for producing rice according to any one of claims 1 to 3, comprising an oil and an enzyme, and containing the enzyme in an amount such that the enzyme activity is 0.50 U or more per 0.1 to 5.0 g of oil.

9. The rice cooking composition according to claim 8, comprising 0.1 to 9 parts by mass of an emulsifier per 100 parts by mass of fats and oils, the enzyme being one or more selected from amylase, cellulase, hemicellulase, cyclodextrin glucanotransferase, glucanotransferase, protease, lipase, glucosidase and pectinase, and the amount of the enzyme being an amount that results in an enzyme activity of 0.50 to 50,000.00 U per 100 g of raw grain before cooking.

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