Quality improver for cooked rice

Abstract

To provide a quality improving agent for rice which can retain a texture of the rice during low-temperature preservation.SOLUTION: The present invention relates to a liquid quality improving agent for rice which contains (a) gum arabic, (b) xanthan gum or pectin, and (c) a starch decomposed product having a DE value of 20 to 40. The quality improving agent for rice of the present invention can be added in rice cooking. The rice obtained with addition of the quality improving agent for rice of the present invention has a good texture which is retained not only immediately after the rice cooking but also when the rice is preserved at low temperature as chilled rice.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a quality improver for cooked rice. [Background technology]

[0002] In recent years, demand for cooked rice (chilled or frozen cooked rice) distributed in chilled or frozen states and sold in supermarkets, convenience stores, etc. has been increasing. However, cooked rice generally becomes hard over time when stored at low temperatures after cooking, and its texture deteriorates. Therefore, many quality improvers for cooked rice have been proposed, including thickening stabilizers such as gum arabic and pectin, organic acids such as lactic acid and citric acid and their salts, and enzymes such as proteases as active ingredients.

[0003] For example, disclosed products include a cooked rice food product containing 0.12 to 3.00 parts by weight of pectin per 100 parts by weight of cooked rice solids and having a moisture content of 64 to 68% by weight (Patent Document 1), a quality improver for chilled or frozen cooked rice characterized by containing (a) protease, (b) pectin and / or tamarind seed gum, and (c) a glycerin fatty acid ester (Patent Document 2), a quality improver for chilled or frozen cooked rice characterized by containing (a) protease and (b) pectin or tamarind seed gum (Patent Document 3), and a taste improver for cooked rice characterized by containing a non-volatile organic acid such as citric acid, a cold-water-soluble polymeric polysaccharide such as pectin, reduced starch syrup and / or dextrin (Patent Document 4).

[0004] However, the reality is that the above techniques are not necessarily sufficient to maintain the texture (for example, graininess, moistness, and softness) of cooked rice stored in a chilled state. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-252773 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-034611 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-245582 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-159629 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a quality improver for cooked rice that can maintain the texture of cooked rice even when stored at low temperatures. [Means for solving the problem]

[0007] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a liquid preparation that combines two specific types of thickening polysaccharides with a starch hydrolysate having a specific DE value, and have developed the present invention based on this finding.

[0008] That is, the present invention provides a liquid quality improver for cooked rice, characterized by containing the following (a) to (c): (a) gum arabic, (b) xanthan gum or pectin; (c) Starch hydrolysates with a DE value of 20 to 40. [Effects of the Invention]

[0009] Cooked rice obtained by adding the quality improver for cooked rice of the present invention has an excellent texture even after storage at low temperatures. DETAILED DESCRIPTION OF THE INVENTION

[0010] The quality improver for cooked rice of the present invention contains gum arabic as component (a), xanthan gum or pectin as component (b), and a starch hydrolysate having a DE value of 20 to 40 as component (c).

[0011] Gum arabic, which is component (a) of the cooked rice quality improver of the present invention, is obtained by drying or desalting the secretions of Acacia Senegal Willdenow or other plants of the same genus, and is composed primarily of polysaccharides. Commercially available gum arabic can be used.

[0012] Xanthan gum, which is the component (b) of the cooked rice quality improver of the present invention, is a polysaccharide produced extracellularly by Xanthomonas campestris and is composed of D-mannose, D-glucose, and D-glucuronic acid. Commercially available xanthan gum can be used.

[0013] Pectin, which is component (b) of the quality improver for cooked rice of the present invention, is a polysaccharide such as methylated polygalacturonic acid obtained from citrus fruits, apples, etc., and examples thereof include high methoxyl pectin (HM) and low methoxyl pectin (LM), with high methoxyl pectin being preferred. Commercially available pectins can be used.

[0014] The starch hydrolysates, which are component (c) of the quality improver for cooked rice of the present invention, are various intermediates obtained by hydrolyzing a paste prepared by heating starch together with water with an acid or enzyme, and have a DE (Dextrose Equivalent) value of 20 to 40, preferably 27 to 38.

[0015] DE value is generally an index of the degree of starch decomposition, and indicates the proportion of dextrin and reducing sugars such as glucose and maltose produced when starch is hydrolyzed. DE value is calculated by measuring reducing sugars as glucose using the Willstätter-Schudel method and calculating the ratio of reducing sugars to 100% solids. The higher the DE value, the higher the reducing sugar content and the lower the dextrin content; conversely, the lower the DE value, the lower the reducing sugar content and the higher the dextrin content. In other words, DE value is calculated using the following formula: DE value = direct reducing sugars (expressed as glucose) / solids x 100

[0016] The quality improver for cooked rice of the present invention is preferably in the form of a preparation containing the above-mentioned components (a) to (c) and being liquid at room temperature (0 to 30° C.) The method for producing such a quality improver for cooked rice is not particularly limited, and any method known per se can be used, but it can be produced, for example, by the following steps (1) and (2). Step (1): Components (a) to (c) are added to water and stirred at room temperature (15°C or higher but lower than 25°C) or while heating to 25 to 90°C, preferably about 50 to 80°C, to obtain a solution. Step (2): If necessary, the solution obtained in step (1) is cooled to 40°C or below to obtain a quality improver for cooked rice that is liquid at room temperature.

[0017] For the stirring in the step (1), a stirrer such as a propeller stirrer, a TK mixer (manufactured by Primix Corporation), or a Clearmix (manufactured by M Technique Co., Ltd.) can be used. When a TK mixer is used for stirring, the rotation speed is preferably 3,000 to 10,000 rpm, and the stirring time in the step (1) is preferably about 1 to 60 minutes.

[0018] In 100% by mass of the quality improver for cooked rice of the present invention, it is preferable to adjust the amount of component (a) to be 3.0 to 10.0% by mass, preferably 4.0 to 8.0% by mass, component (b) to be 0.05 to 1.0% by mass, preferably 0.1 to 0.7% by mass, component (c) to be 20 to 70% by mass, preferably 25 to 60% by mass, and the remainder to be water.

[0019] In addition to the above components (a) to (c), the cooked rice quality improver of the present invention can contain components used for preparing liquid preparations or improving the quality of cooked rice, etc. Examples of such components include monosaccharides such as glucose and fructose, oligosaccharides such as sucrose, lactose, and maltose, maltooligosaccharides such as maltotriose, maltotetraose, maltopentaose, and maltohexaose, sugar alcohols such as sorbitol, mannitol, maltitol, reduced starch syrup, and glycerin, alcohols such as ethanol and propylene glycol, brewed vinegar, acetic acid, and acetate salts.

[0020] The cooked rice quality improver of the present invention can be added during cooking of cooked rice. Specific examples include a method of placing raw rice or washed rice and the cooked rice quality improver of the present invention in a rice cooker, adding water, and cooking the rice, and a method of placing raw rice or washed rice in a rice cooker, adding a water dispersion of the cooked rice quality improver of the present invention, and cooking the rice. There are no particular restrictions on the amount of water used for cooking rice; for example, rice can be cooked with an amount of water added that is 1.5 to 1.7 times the mass of raw rice.

[0021] In the present invention, there is no particular limitation on the amount of the improving agent for cooked rice added, but it is usually 0.5 to 10.0% by mass, and preferably 1.0 to 5.0% by mass, relative to 100% by mass of raw rice.

[0022] There are no particular limitations on the type of rice cooker that can be used in the present invention, and examples include electric rice cookers, gas rice cookers, electromagnetic heating rice cookers, steam rice cookers, pressure cooker rice cookers, and other batch or continuous rice cookers and rice cooking equipment.

[0023] Examples of cooked rice according to the present invention include cooked rice obtained by cooking polished rice, as well as brown rice, red rice, steamed rice, seasoned rice, pilaf, fried rice, dry curry, sushi, rice balls, and the like.

[0024] The cooked rice can be produced as chilled cooked rice by storing the cooked rice in a chilled temperature range (e.g., 1 to 15°C) in a conventional manner, or as frozen cooked rice by freezing and storing the cooked rice at -5°C or below in a conventional manner.

[0025] The chilled cooked rice and frozen cooked rice can be eaten as is, for example, in the case of chilled sushi, but can usually be cooked and eaten by a conventional method. The cooking method is not particularly limited, but examples include a method of returning the cooked rice to room temperature, such as natural thawing, or a method of cooking the cooked rice by heating in a microwave oven.

[0026] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. [Example]

[0027] [Production of quality improver for cooked rice] (1) Raw materials 1) Gum arabic (product name: Arabic Coal SS; manufactured by Sanei Pharmaceutical Trading Co., Ltd.) 2) Xanthan gum (trade name: Grindsted Xanthan Clear 80; manufactured by Danisco Japan Co., Ltd.) 3) HM pectin (trade name: UNIPECTINE AYD 5110SB; manufactured by Unitech Foods) 4) Guar gum (trade name: SUPERGEL CSA 200 / 50; Pakistan Gum and Chemical Company) 5) Glucomannan (product name: Reolex One; manufactured by Shimizu Chemical Co., Ltd.) 6) Starch hydrolysate A (trade name: Maldeck PH400P; DE value: 33; manufactured by Showa Sangyo Co., Ltd.) 7) Starch Hydrolysate B (trade name: SPD; DE value: 30; manufactured by Showa Sangyo Co., Ltd.) 8) Starch Hydrolysate C (trade name: Pine Index #3; DE value: 25; manufactured by Matsutani Chemical Co., Ltd.) 9) Starch Hydrolysate D (trade name: TK-16; DE value: 18; manufactured by Matsutani Chemical Co., Ltd.) 10) Starch Hydrolysate E (trade name: Pine Index #2; DE value: 11; manufactured by Matsutani Chemical Co., Ltd.) 11) Starch Hydrolysate F (trade name: Pine Index #100; DE value: 4; manufactured by Matsutani Chemical Co., Ltd.) 12) Sodium acetate (trade name: sodium acetate anhydride; manufactured by Daito Chemical Co., Ltd.) 13) Glacial acetic acid (product name: 80% pure acetic acid; manufactured by Daicel Corporation) 14)Water

[0028] (2) Formulated with quality improvers for cooked rice The blending compositions of quality improvers for cooked rice 1 to 19 prepared using the above raw materials are shown in Tables 1 and 2. Of these, quality improvers for cooked rice 1 to 11 are examples according to the present invention, and quality improvers for cooked rice 12 to 19 are comparative examples.

[0029] [Table 1]

[0030] [Table 2]

[0031] (3) Manufacturing method of quality improver for cooked rice Each raw material was added to water according to the blending ratios in Tables 1 and 2, and the mixture was stirred and dissolved at 5,000 rpm for 5 minutes at approximately 70°C using a TK mixer (model: TK HOMOMIXER MARK II, manufactured by Primix Corporation) to obtain a solution. The solution was then cooled to room temperature below 40°C to obtain cooked rice quality improvers 1 to 19, which are liquid at room temperature. The amount of each improver was 500 g.

[0032] [Test example] (1) Preparation of cooked rice 450 g of water was added to 300 g of raw rice (product name: Wash-free Koshihikari; Senda Mizuho Co., Ltd.), and the mixture was left to stand at room temperature for 30 minutes. 3 g of each of cooked rice quality improvers 1 to 19 was then added and the rice was cooked in an electric rice cooker (model: JAI-R551; Tiger Corporation). The cooked rice was then packed into 100 g containers (lid size: 110 mm × 130 mm × 18 mm; lid material: 0.15 mm thick polystyrene sheet; body size: 110 mm × 130 mm × 15 mm; body material: 0.35 mm thick polystyrene and polypropylene sheet) and allowed to cool.

[0033] (2) Evaluation test of cooked rice immediately after preparation Immediately after preparing the cooked rice by method (1), a sensory test was conducted. In the sensory test, 10 panelists evaluated the rice according to the evaluation criteria shown in Table 3 below, and the average score was calculated and coded according to the following criteria. The results are shown in Table 5. ◎: Average value 3.5 or higher ○: Average value 2.5 or more and less than 3.5 △: Average value 1.5 or more and less than 2.5 ×: Average value less than 1.5

[0034] [Table 3]

[0035] (3) Evaluation test of chilled cooked rice The cooked rice prepared by method (1) was packed in a container and stored in a refrigerator (model: 503D; Hitachi Refrigeration) at approximately 5°C for 48 hours, after which it was heated in a microwave oven (model: NE-SS30; National) at 700W for 40 seconds and subjected to a sensory evaluation. In the sensory test, 10 panelists evaluated the rice according to the evaluation criteria shown in Table 4 below, and the average score was calculated and coded according to the following criteria. The results are shown in Table 5. ◎: Average value 3.5 or higher ○: Average value 2.5 or more and less than 3.5 △: Average value 1.5 or more and less than 2.5 ×: Average value less than 1.5

[0036] [Table 4]

[0037] [Table 5]

[0038] The results in Table 5 show that cooked rice to which the quality improvers for cooked rice 1 to 11 of the present invention were added maintained a good texture not only immediately after cooking but also when stored at low temperatures as chilled cooked rice. In contrast, cooked rice to which the comparative quality improvers for cooked rice 12 to 19 were added was evaluated as "△" or lower in all evaluation categories, and was inferior to cooked rice to which the quality improvers for cooked rice of the present invention were added.

Claims

[Claim 1] A method for preserving the texture of chilled cooked rice, which comprises adding a liquid quality improver for cooked rice to the water used for cooking the rice, wherein the blending ratios of the following (a) to (c) are adjusted as follows in 100% by mass of the quality improver for cooked rice: (a) Gum arabic 3.0 to 10.0% by mass (b) 0.05 to 1.0% by mass of xanthan gum or pectin (c) 20 to 70% by mass of starch hydrolysate having a DE value of 20 to 40

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