Cooked rice modifier, rice treatment method, preparation method of processed cooked rice

Abstract

To provide a modifier that has a remarkable effect on improving physical properties of cooked rice.SOLUTION: Provided is a cooked rice modifier that includes as active principle a first component being highly branched cyclic dextrin and a second component being at least one kind selected from a group consisting of maltose, glucose, and maltotriose. The second component is preferably maltose. The modifier preferably further includes a third component being at least one kind selected from a group consisting of 4-α-glucanotransferase and amylase. Also provided are: a rice treatment method for treating rice by contacting the cooked rice modifier with the rice; and a preparation method for a processed cooked rice including processing the rice treated by the rice treatment method to obtain a processed cooked rice.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an improving agent for cooked rice, a method for treating rice, and a method for producing processed cooked rice. The improving agent for cooked rice of the present invention significantly improves the physical properties of cooked rice. [Background technology]

[0002] Technologies for improving the flavor of cooked rice during cooking have been studied for some time. For example, physical methods that devise conditions such as soaking time, temperature, and pressure during cooking, and methods that add enzyme preparations, polysaccharides, oils and fats, pH adjusters, etc. have been reported (e.g., Patent Documents 1 to 3). In particular, various types of polysaccharides have been studied, and at the same time, development and analysis of novel polysaccharides are also progressing. Among them, highly branched cyclic dextrins are known to exhibit various excellent functions, and for example, a case has been reported in which this was applied to improve the physical properties of bread (Patent Document 4).

[0003] Incidentally, products containing processed rice (chilled rice), which is stored and served in a refrigerated state and is intended to be heated in a microwave oven (microwave heating device) before eating, such as boxed lunches sold at convenience stores and the like, are becoming widespread. Boxed lunches sold at convenience stores and the like are generally stored and displayed at a temperature of 3 to 8°C. When the user is ready to eat the product, the container is heated in a microwave oven. This makes the chilled rice in a refrigerated state warm to the same temperature as rice immediately after cooking.

[0004] In addition, there are also processed rice products, such as onigiri rice balls sold at convenience stores, that are stored and served at room temperature (below 17°C) rather than refrigerated, and are heated in a microwave oven or other device as needed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-147917 [Patent Document 2] International Publication No. 2006 / 129691 [Patent Document 3] JP 2008-245582 A [Patent Document 4] JP 2017-195815 A [Patent Document 5] Special Publication No. 61-33537 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional chilled rice becomes hard and loses its stickiness as the time passes during refrigeration. When such chilled rice is heated in a microwave oven, it becomes warm, but is hard and not sticky, and has a poor texture. Therefore, there has been a demand for chilled rice after heating to have a texture as close as possible to that of freshly cooked rice. There has also been a similar demand for processed rice that is stored and served at room temperature, such as the above-mentioned rice balls. Note that the technology described in Patent Document 5 is related to improving the flavor of cooked rice immediately after cooking, and is not intended to be applied to processed rice such as chilled rice that is heated in a microwave oven.

[0007] Therefore, an object of the present invention is to provide an improving agent that is significantly effective in improving the physical properties of cooked rice. [Means for solving the problem]

[0008] The present inventors have developed an agent capable of improving the physical properties of cooked rice. As a result, they have succeeded in developing an excellent cooked rice improving agent by combining highly branched cyclic dextrin with maltose, glucose, or maltotriose.

[0009] One aspect of the present invention is a cooked rice improving agent comprising, as active ingredients, a first component which is a highly branched cyclic dextrin and a second component which is at least one selected from the group consisting of maltose, glucose, and maltotriose.

[0010] This aspect relates to a cooked rice improving agent, which is characterized by containing as active ingredients a first component which is a highly branched cyclic dextrin and a second component which is at least one selected from the group consisting of maltose, glucose, and maltotriose. The cooked rice improving agent of this aspect is highly effective in improving the physical properties of cooked rice. In addition, the cooked rice improving agent of this aspect can exhibit an effect of suppressing aging of cooked rice.

[0011] The "physical properties" of cooked rice referred to here mainly refer to the softness, stickiness, and elasticity of cooked rice. Also, the "aging" of cooked rice refers to the deterioration of the physical properties of cooked rice over time. Inhibiting the aging of cooked rice can be said to be one aspect of improving the physical properties of cooked rice.

[0012] Preferably, the second component is maltose.

[0013] Preferably, the concentration of the highly branched cyclic dextrin is 4 ppm or more and 300,000 ppm or less, and the concentration of the maltose is 40 ppm or more and 900,000 ppm or less.

[0014] Preferably, the second component is at least one selected from the group consisting of glucose and maltotriose.

[0015] Preferably, the concentration of the highly branched cyclic dextrin is 4 ppm or more and 300,000 ppm or less, and the concentration of the second component is 40 ppm or more and 900,000 ppm or less.

[0016] Preferably, it further contains a third component which is at least one selected from the group consisting of 4-α-glucanotransferase and amylase.

[0017] In addition to the first and second components, the cooked rice improving agent of this preferred aspect further contains a third component, which is at least one selected from the group consisting of 4-α-glucanotransferase and amylase. With this composition, it is possible to obtain an even more excellent effect of improving the physical properties of cooked rice.

[0018] Another aspect of the present invention is a method for treating rice, comprising contacting rice with the cooked rice improving agent described above to treat said rice.

[0019] This aspect relates to a method for treating rice, which is characterized in that the rice is treated by contacting the above-mentioned cooked rice improving agent with the rice. With this configuration, it is possible to provide rice suitable for producing processed cooked rice with improved physical properties and excellent texture.

[0020] Another aspect of the present invention is a method for producing processed cooked rice, which comprises processing rice treated by the above method to obtain processed cooked rice.

[0021] This aspect relates to a method for producing processed cooked rice, and is characterized in that the rice treated by the above method is processed to obtain processed cooked rice. According to this aspect, it is possible to provide processed cooked rice with improved physical properties. Effect of the Invention

[0022] The cooked rice improving agent of the present invention is highly effective in improving the physical properties of processed cooked rice, and as a result, it is possible to provide processed cooked rice with excellent texture.

[0023] According to the rice processing method of the present invention, it is possible to provide rice which has significantly improved physical properties and is suitable for producing processed cooked rice with excellent texture.

[0024] According to the method for producing processed cooked rice of the present invention, it is possible to provide processed cooked rice having significantly improved physical properties and excellent texture. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, the embodiment of the present invention will be specifically described.

[0026] The cooked rice improving agent of the present invention contains, as active ingredients, a first component which is a highly branched cyclic dextrin, and a second component which is at least one selected from the group consisting of maltose, glucose, and maltotriose.

[0027] <Highly branched cyclic dextrin> Highly branched cyclic dextrin is a type of glucan that is composed of a main chain and numerous branch chains and has a cyclic structure. The main chain is a glycan in which numerous sugars are linked by α-1,4-glucosidic bonds, just like amylose, and one end is connected to one of the branch chains by an α-1,6 bond, forming the main part of the cyclic structure. The branch chain is a glycan in which one end is connected to the main chain or another branch chain by an α-1,6 bond, and some of them form part of the cyclic structure, while others do not.

[0028] One method for producing highly branched cyclic dextrin is, for example, to apply a branching enzyme (EC2.4.1.18) to starch. Starch consists of amylose, in which glucose is linearly linked via α-1,4-glucosidic bonds, and amylopectin, which has a complex branched structure via α-1,6-glucosidic bonds. Amylopectin is a macromolecule in which many cluster structures are linked together. Branching enzymes are glucan chain transferases that are widely present in various organisms and act on the joints of the amylopectin cluster structure, catalyzing the reaction that cyclizes it.

[0029] The highly cyclic dextrin contained in the cooked rice improving agent of the present invention may be derived from any raw material, and may be refined or not and by any method. For example, starch refined by artificially treating it with a branching enzyme may be used. In addition, similar enzymes may be added to the improving agent to cause a reaction to produce highly cyclic dextrin therein.

[0030] The concentration of the highly branched cyclic dextrin in the cooked rice improving agent of the present invention, i.e., the ratio (mass ratio) of the highly branched cyclic dextrin to the entire cooked rice improving agent, is not particularly limited, but is preferably 4 ppm or more and 300,000 ppm or less (4 mg / kg or more and 300,000 mg / kg or less), preferably 40 ppm or more and 200,000 ppm or less (40 mg / kg or more and 200,000 mg / kg or less). If the highly branched cyclic dextrin concentration is less than 4 ppm, even if the amount of the improving agent used for cooked rice is extremely increased, the desired physical property improvement effect may not be obtained. On the other hand, if the highly branched cyclic dextrin concentration is more than 300,000 ppm, even if the amount of the improving agent used is extremely reduced, the rice grains may lose their cohesion and the taste may deteriorate.

[0031] <Second component> The cooked rice improving agent of the present invention contains at least one selected from the group consisting of maltose, glucose, and maltotriose as the second component. Maltose, glucose, and maltotriose may be contained alone or in combination of two or more. In one preferred embodiment, at least maltose is contained as the second component. In one preferred embodiment, at least one selected from the group consisting of glucose and maltotriose is contained as the second component.

[0032] <Maltose> Maltose (malt sugar) is a reducing disaccharide consisting of two glucose molecules linked by an α-1,4-glycosidic bond.

[0033] When maltose is used as the second component, the maltose may be derived from any raw material, and may be refined or not refined by any method. For example, maltose contained in malt such as barley may be used. In addition, maltose refined by artificially treating starch with an enzyme may be used. In addition, similar enzymes may be added to the improver to cause a maltose-producing reaction in the improver.

[0034] The concentration of maltose in the cooked rice improving agent of the present invention, i.e., the ratio (mass ratio) of highly branched cyclic maltose to the entire cooked rice improving agent, is not particularly limited, but is preferably 40 ppm or more and 900000 ppm or less (40 mg / kg or more and 900000 mg / kg or less), preferably 400 ppm or more and 600000 ppm or less (400 mg / kg or more and 600000 mg / kg or less). If the maltose concentration is less than 40 ppm, even if the amount of the improving agent used for cooked rice is extremely increased, the desired physical property improvement effect may not be obtained. On the other hand, if the maltose concentration is more than 900000 ppm, even if the amount of the improving agent used is extremely reduced, the sweetness of maltose may adversely affect the flavor of cooked rice and the rice may become sticky.

[0035] <Glucose> When glucose (grape sugar) is used as the second component, the glucose may be derived from any raw material, and may be refined or not refined, and the method of refinement is not important. For example, glucose contained in starch syrup may be used. Also, glucose refined by artificially hydrolyzing starch or treating it with an enzyme may be used. In addition, similar enzymes may be added to the improver to cause a glucose-producing reaction in the improver.

[0036] The glucose concentration in the cooked rice improving agent of the present invention, i.e., the ratio (mass ratio) of highly branched cyclic glucose to the entire cooked rice improving agent, is not particularly limited, but is preferably 40 ppm or more and 900000 ppm or less (40 mg / kg or more and 900000 mg / kg or less), preferably 400 ppm or more and 600000 ppm or less (400 mg / kg or more and 600000 mg / kg or less). If the glucose concentration is less than 40 ppm, even if the amount of the improving agent used for cooked rice is extremely increased, the desired physical property improvement effect may not be obtained. On the other hand, if the glucose concentration is more than 900000 ppm, even if the amount of the improving agent used is extremely reduced, the sweetness of glucose may adversely affect the flavor of cooked rice and may become sticky.

[0037] <Maltotriose> Maltotriose is a trisaccharide formed by the α-1,4-glycosidic bond of three glucose molecules.

[0038] When maltotriose is used as the second component, the maltotriose may be derived from any raw material, and may be purified or not purified by any method. For example, maltotriose purified by artificially treating starch with an enzyme may be used. In addition, a similar enzyme may be added to the improving agent to cause a reaction to produce maltotriose in the improving agent.

[0039] The concentration of maltotriose in the cooked rice improving agent of the present invention, i.e., the ratio (mass ratio) of highly branched cyclic maltotriose to the entire cooked rice improving agent, is not particularly limited, but is preferably 40 ppm or more and 900000 ppm or less (40 mg / kg or more and 900000 mg / kg or less), preferably 400 ppm or more and 600000 ppm or less (400 mg / kg or more and 600000 mg / kg or less). If the maltotriose concentration is less than 40 ppm, even if the amount of the improving agent used for cooked rice is extremely increased, the desired physical property improvement effect may not be obtained. On the other hand, if the maltotriose concentration is more than 900000 ppm, even if the amount of the improving agent used is extremely reduced, the sweetness of maltotriose may adversely affect the flavor of cooked rice and may become sticky.

[0040] <Other ingredients> The cooked rice improving agent of the present invention may contain other components as long as the performance is not impaired. For example, an enzyme may be further contained. The enzyme may be of any type as long as it is applicable to food, and may be derived from any raw material. Examples of the enzymes used in the present invention include amylase, protease, lipase, cellulase, nuclease, glycosidase, glycosyltransferase, etc. These enzymes may be used alone or in combination of two or more. The enzymes may be used, for example, in the form of food raw materials or enzyme preparations having the activity. Examples of food raw materials having the enzyme activity include yellow koji, white koji, etc.

[0041] <Third component> In one preferred embodiment, the third component contains at least one enzyme selected from the group consisting of 4-α-glucanotransferase and amylase. These enzymes can also be used, for example, in the form of a food ingredient or enzyme preparation having the activity. These enzymes may be used alone or in combination. 4-α-glucanotransferase is a type of glycosyltransferase that acts on the glycosidic bond of starch to catalyze the reaction of transferring sugars. An example of 4-α-glucanotransferase is maltotriosyltransferase, which transfers sugars in three sugar units. Amylase is the name of a group of enzymes that convert amylose and amylopectin in starch into monosaccharides, disaccharides, and oligosaccharides by hydrolyzing glycosidic bonds. Examples of amylase include α-amylase, glucoamylase, β-amylase, pullulanase, and maltotriohydrolase. α-amylase is preferably used.

[0042] The content of the third component in the cooked rice improving agent of the present invention is not particularly limited, but for example, 800 to 7500 units of 4-α-glucanotransferase can be contained in 100 g of the cooked rice improving agent, and 1 to 730000 units of amylase can be contained in 100 g of the cooked rice improving agent. The activity of 4-α-glucanotransferase, for example, maltotriosyltransferase, can be measured by the method described in WO 2011 / 001722. The activity of amylase (α-amylase) is defined as the amount (mL) of 1% soluble starch decomposed at 40° C. in 30 minutes, and can be measured, for example, by the method described in JP 2011-162491 A.

[0043] <Form of cooked rice improver> The form of the cooked rice improving agent of the present invention is not particularly limited, and may be, for example, in the form of a powder, liquid, etc. In addition, it may be in the form of a granule, tablet, emulsion, paste, etc.

[0044] <Method of manufacturing the cooked rice improving agent> The cooked rice improving agent of the present invention can be produced, for example, as follows. First, highly branched cyclic dextrin (first component) and maltose, glucose, or maltotriose (second component) are prepared. If necessary, 4-α-glucanotransferase or amylase (third component) is prepared. For example, highly branched cyclic dextrin produced by acting a branching enzyme on starch as a raw material can be used. For example, maltose produced by acting α-amylase on starch can be used. For example, glucose produced by hydrolyzing starch can be used. For example, maltotriose produced by acting amylase on starch can be used. For example, enzyme preparations can be used as 4-α-glucanotransferase and amylase. If necessary, other raw materials such as other enzymes, salt, alcohol, and seasoning liquid are prepared. Each raw material is mixed, and then a required amount of water is added and mixed so that the final concentration of each raw material is a predetermined value, particularly so that the final concentrations of the highly branched cyclic dextrin and maltose, glucose, or maltotriose are a predetermined value. This makes it possible to obtain a liquid cooked rice improving agent that contains the first and second components as active ingredients and, if necessary, the third component. When making the product into a powder or granule form, known formulation techniques such as granulation and drying can be appropriately used.

[0045] <How to use rice improver> The cooked rice improving agent of the present invention can be added to rice during cooking. The amount of the cooked rice improving agent of the present invention used is not particularly limited, and can be appropriately set depending on the highly branched cyclic dextrin concentration, maltose concentration, glucose concentration, maltotriose concentration, etc. of the cooked rice improving agent, and further depending on the type of cooked rice, cooking method, etc. As an example, the cooked rice improving agent can be used in an amount of 0.05 to 10 parts by mass, 0.1 to 5 parts by mass, 0.15 to 3 parts by mass, etc., per 100 parts by mass of rice.

[0046] <Rice processing method, manufacturing method of processed cooked rice> The present invention includes a method for treating rice, in which rice is brought into contact with the above-mentioned cooked rice improving agent to treat the rice. The present invention also includes a method for producing processed cooked rice, in which rice treated by the above-mentioned method is processed to obtain processed cooked rice. There is no particular limitation on the type of rice to be treated by contacting with the cooked rice improving agent of the present invention, and for example, both non-glutinous rice and glutinous rice can be the target. Furthermore, the type of cooked rice (processed cooked rice) obtained by processing rice treated with the cooked rice improving agent of the present invention is typically white rice, but also includes cooked rice with seasonings or ingredients such as vinegared rice, red rice, steamed rice, and cooked rice with ingredients (kayaku rice).

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. EXAMPLES

[0048] 150 g of unwashed Koshihikari rice was weighed into a 500 mL beaker, 225 mL of ion-exchanged water was added, and the rice was soaked at room temperature (20°C) for 2 hours, and then cooked in a pressure IH rice cooker (manufactured by Zojirushi Corporation) to obtain warm rice (Experimental Example 1-1). Meanwhile, 10 mg of highly branched cyclic dextrin (Glico Nutrition Foods Co., Ltd.'s "Cluster Dextrin") and 100 mg of maltose were added during cooking, and warm rice was obtained in the same manner as in Experimental Example 1-1 (Experimental Example 1-2). The obtained warm rice was subjected to a sensory evaluation test by 10 experienced panelists for softness, stickiness, and elasticity. The following evaluation criteria were adopted for the sensory evaluation test. The results are shown in Table 1.

[0049] (1) Softness For example 1-1, if the softness rating is low: 1 point - For Experimental Example 1-1, if the softness rating is slightly lower: 2 points - If the softness rating is the same as that of Experimental Example 1-1: 3 points - For example 1-1, if the softness rating is slightly higher: 4 points For example 1-1, if the softness is high: 5 points (2) Tenacity For Experimental Example 1-1, if the stickiness rating is low: 1 point - If the stickiness rating is slightly lower than in Experimental Example 1-1: 2 points - If the stickiness rating is the same as that of Experimental Example 1-1: 3 points - If the stickiness rating is slightly higher than in Experimental Example 1-1: 4 points For Example 1-1, if the stickiness is high: 5 points (3) Elasticity For Experimental Example 1-1, if the elasticity is low: 1 point - If the elasticity rating is slightly lower than that of Experimental Example 1-1: 2 points - If the elasticity rating is the same as that of Experimental Example 1-1: 3 points - If the elasticity rating is slightly higher than that of Experimental Example 1-1: 4 points For example 1-1, if the elasticity is high: 5 points

[0050] [Table 1] EXAMPLES

[0051] 150 g of unwashed Koshihikari rice was weighed into a 500 mL beaker, 225 mL of ion-exchanged water was added, and the rice was soaked at room temperature (20°C) for 2 hours, and then cooked in a pressure IH rice cooker (manufactured by Zojirushi Corporation) to obtain warm cooked rice. This cooked rice was refrigerated at a temperature of 3 to 8°C. The refrigerated cooked rice was stored at 10°C for 30 hours to obtain chilled cooked rice (Experimental Example 2-1).

[0052] 10 mg of highly branched cyclic dextrin ("Cluster Dextrin" manufactured by Glico Nutrition Foods Co., Ltd.) and 100 mg of maltose were added during cooking, and chilled cooked rice was obtained in the same manner as in Experimental Example 2-1 (Experimental Example 2-2).

[0053] A sensory evaluation test was conducted by 10 experienced panelists on the softness, stickiness, and elasticity of the cooked rice of Experimental Example 2-1 and Experimental Example 2-2. The following evaluation criteria were adopted for the sensory evaluation test. The results are shown in Table 2.

[0054] (1) Softness For Experimental Example 2-1, if the softness rating is low: 1 point - If the softness rating is slightly lower than in Experimental Example 2-1: 2 points - If the softness rating is the same as that of Experimental Example 2-1: 3 points - If the softness rating is slightly higher than in Experimental Example 2-1: 4 points For example 2-1, if the softness is high: 5 points (2) Tenacity For Experimental Example 2-1, if the stickiness is poor: 1 point - If the stickiness rating is slightly lower than in Experimental Example 2-1: 2 points - If the stickiness rating is the same as that of Experimental Example 2-1: 3 points - If the stickiness rating is slightly higher than in Experimental Example 2-1: 4 points For Experimental Example 2-1, if the stickiness is high: 5 points (3) Elasticity - For Experimental Example 2-1, if the elasticity is low: 1 point - If the elasticity rating is slightly lower than that of Experimental Example 2-1: 2 points - If the elasticity rating is the same as that of Experimental Example 2-1: 3 points - If the elasticity rating is slightly higher than that of Experimental Example 2-1: 4 points For Experimental Example 2-1, if the elasticity is high: 5 points

[0055] [Table 2]

[0056] As a result, the rice in Experimental Example 2-1, which had been stored refrigerated, was evaluated as not tasty and hard and solidified, and it was found that the taste of the cooked rice deteriorated due to storage in the refrigerator. In contrast, the cooked rice in Experimental Example 2-2, despite being stored in the refrigerator, was tasty and had a proper sense of softness, stickiness, and elasticity. This shows that the softness, stickiness, and elasticity of chilled cooked rice can be improved by adding highly branched cyclic dextrin and maltose during cooking. EXAMPLES

[0057] The chilled cooked rice of Experimental Example 2-1 and the chilled cooked rice of Experimental Example 2-2 were each heated in a microwave oven (model number NE-JW20, manufactured by Panasonic Corporation) at 600 W for 1 minute (microwave up) to obtain warm cooked rice (Experimental Example 3-1, Experimental Example 3-2).

[0058] A sensory evaluation test was conducted by 10 experienced panelists on the softness, stickiness, and elasticity of the cooked rice of Experimental Example 3-1 and Experimental Example 3-2. The following evaluation criteria were adopted for the sensory evaluation test. The results are shown in Table 3.

[0059] (1) Softness For Experimental Example 3-1, if the softness rating is low: 1 point - If the softness rating is slightly lower than in Experimental Example 3-1: 2 points - If the softness rating is the same as that of Experimental Example 3-1: 3 points - For example 3-1, if the softness rating is slightly higher: 4 points For example 3-1, if the softness rating is high: 5 points (2) Tenacity For Experimental Example 3-1, if the stickiness is poor: 1 point - If the stickiness rating is slightly lower than in Experimental Example 3-1: 2 points - If the stickiness rating is the same as that of Experimental Example 3-1: 3 points - If the stickiness rating is slightly higher than in Experimental Example 3-1: 4 points For Experimental Example 3-1, if the stickiness is high: 5 points (3) Elasticity - For Experimental Example 3-1, if the elasticity is low: 1 point - If the elasticity rating is slightly lower than in Experimental Example 3-1: 2 points - If the elasticity rating is the same as that of Experimental Example 3-1: 3 points - If the elasticity rating is slightly higher than in Experimental Example 3-1: 4 points For example 3-1, if the elasticity is high: 5 points

[0060] [Table 3]

[0061] As a result, it was found that the rice in Experimental Example 3-1, which was refrigerated and then reheated in the microwave, tasted similar to normal rice, and that the rice tasted closer to that of freshly cooked rice when reheated in the microwave. In contrast, the rice in Experimental Example 3-2 was superior in terms of softness, stickiness, and elasticity. This shows that the addition of highly branched cyclic dextrin and maltose during cooking improves the softness, stickiness, and elasticity of chilled rice that was refrigerated and then reheated. EXAMPLES

[0062] The fermented seasoning liquid, ordinary salt, 95% alcohol, highly branched cyclic dextrin, maltose (malt sugar), and ion-exchanged water were mixed in the proportions shown in Table 4 to obtain the seasonings of Experimental Example 4-1 to Experimental Example 4-4.

[0063] [Table 4]

[0064] 150g of no-rinse rice was weighed, an appropriate amount of ion-exchanged water was added, and the rice was soaked at room temperature (20°C) for 1 hour. The ion-exchanged water was then replaced and water was added until the amount of water reached 240g. Four test sections were prepared. 1.8g of rice cooking oil and 2.2g of any of the seasonings from Experimental Examples 4-1 to 4-4 were added to the rice and cooked in a pressure induction rice cooker. After removing the heat from the cooked rice, 58g of combined vinegar was added and mixed well to make vinegared rice. This vinegared rice was refrigerated at 5°C for 48 hours to obtain chilled vinegared rice.

[0065] A sensory evaluation test was conducted by 10 experienced panelists to determine the degree of aging for chilled vinegared rice prepared using the seasonings of Experimental Examples 4-1 to 4-4. The following evaluation criteria were used for the sensory evaluation test. As mentioned above, aging refers to the deterioration of the physical properties of cooked rice over time. The results are shown in Table 5.

[0066] - For Experimental Example 4-1, if aging is advanced: 1 point - In Experimental Example 4-1, if aging is somewhat advanced: 2 points - If the aging process is the same as in Experimental Example 4-1: 3 points - For Experimental Example 4-1, if aging is not progressing well: 4 points - For Experimental Example 4-1, if aging is not progressing: 5 points

[0067] [Table 5]

[0068] As a result, the cooked rice of Experimental Examples 4-2 and 4-3 had the same or slightly faster aging as Experimental Example 4-1. In contrast, the cooked rice of Experimental Example 4-4 had a slower aging than any of Experimental Examples 4-1 to 4-3. This shows that the addition of a seasoning (rice improver) containing both highly branched cyclic dextrin and maltose during cooking suppresses the aging of chilled cooked rice, which was not observed when a seasoning containing only one of the respective ingredients was used. EXAMPLES

[0069] The fermented seasoning liquid, ordinary salt, 95% alcohol, highly branched cyclic dextrin, maltose (malt sugar), and 4-α-glucanotransferase (Amano Enzyme Co., Ltd.'s "Glycotransferase 'Amano' L"; maltotriosyltransferase; enzyme titer 3,000,000 U / g), and ion-exchanged water were mixed in the proportions shown in Table 6 to obtain the seasonings of Experimental Example 5-1 to Experimental Example 5-3.

[0070] [Table 6]

[0071] Each of the seasonings from Experimental Example 5-1 to Experimental Example 5-3 was added in an amount of 1 mg during rice cooking, and chilled vinegared rice was obtained in the same manner as in Example 4.

[0072] A sensory evaluation test was conducted by 10 experienced panelists to determine the degree of aging for chilled vinegared rice prepared using the seasonings of Experimental Examples 5-1 to 5-3. The sensory evaluation test was conducted using the following evaluation criteria. The results are shown in Table 7.

[0073] (1) Aging - For Experimental Example 5-1, if aging is advanced: 1 point - For example 5-1, if aging is slightly advanced: 2 points - If the aging process is the same as in Experimental Example 5-1: 3 points - For Experimental Example 5-1, if aging is not progressing well: 4 points - For Experimental Example 5-1, if aging is not progressing: 5 points

[0074] [Table 7]

[0075] As a result, the aging of the cooked rice of Experimental Example 5-3 was more significantly inhibited than that of the cooked rice of Experimental Example 5-2, which had already been shown to have an anti-aging effect. This shows that the anti-aging effect of the cooked rice improver containing highly branched cyclic dextrin and maltose can be further enhanced by adding 4-α-glucanotransferase. EXAMPLES

[0076] The fermented seasoning liquid, ordinary salt, 95% alcohol, highly branched cyclic dextrin, maltose (malt sugar), α-amylase (enzyme activity 3,000-U / g), and ion-exchanged water were mixed in the proportions shown in Table 8 to obtain the seasonings of Experimental Example 6-1 and Experimental Example 6-2.

[0077] [Table 8]

[0078] The seasoning of Experimental Example 6-1 or Experimental Example 6-2 was added in an amount of 1 mg during rice cooking, and chilled vinegared rice was obtained in the same manner as in Example 4.

[0079] A sensory evaluation test was conducted by 10 experienced panelists to determine the degree of retrogradation of the chilled vinegared rice of Experimental Example 6-1 and Experimental Example 6-2. The sensory evaluation test adopted the following evaluation criteria. The results are shown in Table 9.

[0080] (1) Aging - For Experimental Example 6-1, if aging is advanced: 1 point - For example 6-1, if aging is slightly advanced: 2 points - If the aging process is the same as in Experimental Example 6-1: 3 points - For Experimental Example 6-1, if aging is not progressing well: 4 points - For Experimental Example 6-1, if aging is not progressing: 5 points

[0081] [Table 9]

[0082] As a result, the aging of the cooked rice of Experimental Example 6-2 was more significantly inhibited than that of the cooked rice of Experimental Example 6-1, which had already been shown to have an anti-aging effect. This shows that the anti-aging effect of the cooked rice improver containing highly branched cyclic dextrin and maltose, when further containing α-amylase, is further enhanced. EXAMPLES

[0083] The fermented seasoning liquid, ordinary salt, 95% alcohol, highly branched cyclic dextrin, glucose (dextrose), and ion-exchanged water were mixed in the proportions shown in Table 10 to obtain the seasonings of Experimental Example 7-1 to Experimental Example 7-4.

[0084] [Table 10]

[0085] Each of the seasonings from Experimental Examples 7-1 to 7-4 was added in an amount of 1 mg during rice cooking, and chilled vinegared rice was obtained in the same manner as in Example 4.

[0086] A sensory evaluation test was conducted by 10 experienced panelists to determine the degree of aging for chilled vinegared rice prepared using the seasonings of Experimental Examples 7-1 to 7-4. The sensory evaluation test was conducted using the following evaluation criteria. The results are shown in Table 11.

[0087] - For Experimental Example 7-1, if aging is advanced: 1 point - For Experimental Example 7-1, if aging is slightly advanced: 2 points - If the aging process is the same as in Experimental Example 7-1: 3 points - For Experimental Example 7-1, if aging is not progressing well: 4 points - For Experimental Example 7-1, if aging is not progressing: 5 points

[0088] [Table 11]

[0089] As a result, the cooked rice of Experimental Examples 7-2 and 7-3 had the same or slightly faster aging as Experimental Example 7-1. In contrast, the cooked rice of Experimental Example 7-4 had a slower aging than any of Experimental Examples 7-1 to 7-3. This shows that the addition of a seasoning (rice improving agent) containing both highly branched cyclic dextrin and glucose during cooking of rice exerts a function of suppressing the aging of chilled cooked rice, which was not observed when a seasoning containing only one of the respective components was used. EXAMPLES

[0090] The fermented seasoning liquid, regular salt, 95% alcohol, highly branched cyclic dextrin, malto-oligosaccharide ("Fujioligo #360" manufactured by Nippon Shokuhin Kako Co., Ltd.; maltotriose content 60%), and ion-exchanged water were mixed in the proportions shown in Table 11 to obtain the seasonings of Experimental Example 8-1 to Experimental Example 8-4.

[0091] [Table 12]

[0092] Each of the seasonings from Experimental Example 8-1 to Experimental Example 8-4 was added in an amount of 1 mg during rice cooking, and chilled vinegared rice was obtained in the same manner as in Example 4.

[0093] A sensory evaluation test was conducted by 10 experienced panelists to determine the degree of aging for chilled vinegared rice prepared using the seasonings of Experimental Examples 8-1 to 8-4. The sensory evaluation test was conducted using the following evaluation criteria. The results are shown in Table 13.

[0094] - For Experimental Example 8-1, if aging is advanced: 1 point - For Experimental Example 8-1, if aging is somewhat advanced: 2 points - If the aging process is the same as in Experimental Example 8-1: 3 points - For Experimental Example 8-1, if aging is not progressing well: 4 points - For Experimental Example 8-1, if aging is not progressing: 5 points

[0095] [Table 13]

[0096] As a result, the cooked rice of Experimental Examples 8-2 and 8-3 had the same or slightly faster aging as Experimental Example 8-1. In contrast, the cooked rice of Experimental Example 8-4 had a slower aging than any of Experimental Examples 8-1 to 8-3. This shows that the addition of a seasoning (rice improver) containing both highly branched cyclic dextrin and maltotriose during cooking of rice exerts a function of suppressing the aging of chilled cooked rice, which was not observed when a seasoning containing only one of the respective components was used.

Claims

1. The agent for improving cooked rice contains as active ingredients a first component which is a highly branched cyclic dextrin, and a second component which is at least one selected from the group consisting of maltose, glucose, and maltotriose.

2. The rice improving agent according to claim 1, wherein the second component is maltose.

3. The concentration of the highly branched cyclic dextrin is 4 ppm or more and 300,000 ppm or less, The cooked rice improving agent according to claim 2, wherein the concentration of maltose is 40 ppm or more and 900,000 ppm or less.

4. 2. The rice improving agent according to claim 1, wherein the second component is at least one selected from the group consisting of glucose and maltotriose.

5. The concentration of the highly branched cyclic dextrin is 4 ppm or more and 300,000 ppm or less, The cooked rice improving agent according to claim 4, wherein the concentration of the second component is 40 ppm or more and 900,000 ppm or less.

6. The cooked rice improving agent according to any one of claims 1 to 5, further comprising a third component which is at least one selected from the group consisting of 4-α-glucanotransferase and amylase.

7. A method for treating rice, comprising contacting rice with the cooked rice improving agent according to any one of claims 1 to 5 to treat the rice.

8. A method for treating rice, comprising contacting rice with the improving agent for cooked rice according to claim 6 to treat said rice.

9. A method for producing processed cooked rice, comprising processing rice treated by the method according to claim 7 to obtain processed cooked rice.

10. A method for producing processed cooked rice, comprising processing rice treated by the method according to claim 8 to obtain processed cooked rice.

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