JP5466372B2 - Method for producing cooked rice food and enzyme preparation for modifying cooked rice food - Google Patents

Description

  The present invention relates to an enzyme having transglycosylation activity for converting an α-1,4 bond of a sugar chain into an α-1,6 bond, a method for producing cooked rice food using transglutaminase, and an enzyme preparation for modifying cooked rice food Is.

  If the pregelatinized starch is allowed to stand at room temperature or low temperature, moisture is separated and hardened. This phenomenon is called aging, and many studies have been conducted on the aging phenomenon of starch. Generally, in order to prevent aging, it is necessary to keep the temperature at 80 ° C. or higher, or to dry quickly to bring the moisture to 15% or less, and to keep the pH at 13 or higher. In addition, as a method for preventing aging, a method of adding saccharides (dextrose, fructose, liquid sugar, etc.), soy protein, wheat gluten, fatty acid esters, polysaccharides (eg yam, konjac) to starch-containing foods is generally known. Patent Document 1 describes a method of adding a thickener, a surfactant or the like. However, these methods greatly change the taste, and the effects are unstable, and are not sufficient solutions.

  A method of adding an enzyme as a means for preventing aging is also known. For example, Patent Document 2 describes a method for improving cooked rice in which polished rice is mixed with an enzyme such as amylase, protease, or lipase, and salt and cyclodextrin. Patent Document 3 describes a method for preventing aging of cooked rice by spraying and adding an aqueous solution of saccharified amylase (β-amylase, glucoamylase) to cooked rice. However, various enzyme preparations have been added to rice to try to improve the quality of cooked rice, but none of these have achieved remarkable effects.

According to Patent Document 4, cooked rice that is soft, sticky, and hardly deteriorates over time can be obtained by adding transglucosidase, which is α-glucosidase, to rice during cooking as a physical property improving agent for starch-containing foods. . Although a considerable effect was seen, there was still room for improvement in the loosening properties and physical properties improving effect between rice grains. As described above, it is difficult to achieve both of the above-described methods of improving the texture immediately after cooking and maintaining the excellent texture over a long period of time, and it has not yet been achieved completely. Is the current situation. What is important in determining the physical properties of foods is the state of protein and sugar (starch), but transglutaminase is known as an enzyme effective for improving the physical properties of proteins. In Patent Document 5, when rice is cooked, transglutaminase, protein partial hydrolyzate, oligosaccharide, and sugar alcohol are added to the rice cooking water and cooked. A method for producing cooked rice with a particularly sticky taste is disclosed without any loss, but only the addition of transglutaminase produced a crunchy texture, but with the addition of transglutaminase and wheat protein partial hydrolysate, In comparison, it is described that lack of stickiness and inferior throat. Patent Document 6 describes a method for preventing deterioration of starch that occurs during low-temperature storage or low-temperature circulation of polyhydrated rice by adding transglutaminase. The texture of rice grains is completely different. In addition, an example in which transglutaminase and α-glucosidase are combined to improve physical properties has not been reported yet.
JP 59-2664 JP 58-86050 A JP-A-60-199355 WO2005 / 096839 JP-A-9-206006 Patent 3310081

  An object of the present invention is to provide a method for producing cooked rice food having improved physical properties and taste, and an enzyme preparation for modifying cooked rice food. In particular, the present invention is to provide a method for improving quality (taste and physical properties) immediately after the production of cooked rice food and suppressing quality deterioration due to the passage of time in the production process and the distribution process after production.

As a result of intensive studies, the present inventors have produced the above-mentioned cooked rice food by using an enzyme having transglycosylation activity that converts α-1,4 bonds into α-1,6 bonds and transglutaminase. The inventors have found that the object can be achieved and have completed the present invention. That is, the present invention is as follows.
(1) A method for producing cooked rice food, characterized by using an enzyme having transglycosylation activity for converting an α-1,4 bond of a sugar chain to an α-1,6 bond and transglutaminase.
(2) The method according to (1), wherein the enzyme having transglycosylation activity for converting an α-1,4 bond of a sugar chain into an α-1,6 bond is α-glucosidase.
(3) The method according to (2), wherein the amount of α-glucosidase added is 1.5 to 300,000 U per gram of raw raw rice, and the amount of transglutaminase added is 0.0001 to 100 U per gram of raw raw rice. .
(4) The method according to (2), wherein the addition amount of α-glucosidase is 15 to 150,000 U per gram of raw raw rice and 0.05 to 10 U of transglutaminase is added per gram of raw raw rice.
(5) The method according to (3) or (4), wherein the added amount of α-glucosidase is 0.15 U to 200,000 U per 1 U of transglutaminase.
(6) The method according to (3) or (4), wherein the added amount of α-glucosidase is 90 U to 50,000 U per 1 U of transglutaminase.
(7) An enzyme preparation for improving cooked rice food containing α-glucosidase and transglutaminase.
(8) The enzyme preparation according to (7), wherein the content of α-glucosidase is 0.15 U to 200,000 U per 1 U of transglutaminase.
(9) The enzyme preparation according to (7), wherein the content of α-glucosidase is 90 U to 50,000 U per 1 U of transglutaminase.

  According to the present invention, quality (physical properties such as taste, elasticity, stickiness, graininess, looseness, etc.) immediately after the production of cooked rice food can be improved, and deterioration of the quality of the food over time can be suppressed.

  In the method for producing cooked rice food according to the present invention, an enzyme having transglycosylation activity for converting an α-1,4 bond into an α-1,6 bond and transglutaminase are used. Examples of enzymes with transglycosylation activity that convert α-1,4 bonds to α-1,6 bonds include α-glucosidase (transglucosidase), 1,4-α-glucan branching enzyme, 1,4-α Examples include glucan 6-α-D-glucosyltransferase. The α-glucosidase preferably has a glycosyl transfer ability for converting an α-1,4 bond into an α-1,6 bond, and such α-glucosidase is called a transglucosidase. That is, transglucosidase is α-glucosidase having sugar transfer ability. α-Glucosidase is an enzyme that hydrolyzes the non-reducing terminal α-1,4-glucoside bond to produce α-glucose. Glucoamylase causes a reaction similar to α-glucosidase, but the glucose produced is not α-glucose but β-glucose. Further, the enzyme used in the present invention not only has a degrading activity but also has a suitable acceptor having a hydroxyl group, it transfers glucose from an α-1,4 bond to an α-1,6 bond, thereby branching sugar. It is particularly important that it has glycosyltransferase activity to produce Enzymes contained in conventional physical property improving agents are amylolytic enzymes, not glycosyltransferases. An enzyme commercially available from Amano Enzyme Co., Ltd. under the trade name transglucosidase L “Amano” is an example of an enzyme having transglycosylation activity that converts an α-1,4 bond into an α-1,6 bond. It is.

  Transglutaminase refers to an enzyme having an activity of catalyzing an acyl transfer reaction using a glutamine residue in a protein or peptide as a donor and a lysine residue as an acceptor, and is derived from mammals, fish, microorganisms Those of various origins, such as those of origin, are known. The enzyme used in the present invention may be any enzyme having this activity, and any origin may be used. Moreover, it may be a recombinant enzyme. One example is a transglutaminase derived from a microorganism marketed by Ajinomoto Co., Inc. under the trade name “Activa” TG.

  Examples of the cooked rice food of the present invention include cooked rice (white rice), vinegared rice (sushi rice), red rice, pilaf, cooked rice, rice cake, risotto, rice ball, sushi, bento and rice noodles. These frozen products are also included. When the enzyme having transglycosylation activity for converting α-1,4 bond to α-1,6 bond and transglutaminase are allowed to act on rice, it may be allowed to act at any stage until rice cooking. That is, an enzyme may be added to the immersion liquid in which rice is immersed for water absorption, or the enzyme may be added after cooking and before cooking rice. Moreover, you may make an enzyme sprinkle and act on cooked rice after cooking. In addition, the order in which the enzyme having transglycosylation activity for converting α-1,4 bonds to α-1,6 bonds and transglutaminase are allowed to act on rice is not limited, and after any enzyme is acted first The other enzyme may be allowed to act, but it is preferred to act simultaneously. Furthermore, these enzymes may be used in combination with other enzymes and substances. As the raw material rice, any kind of rice may be used, whether it is soft rice or hard rice, or new rice, old rice or old rice. Moreover, low taste rice or good taste rice may be used. In addition, processed rice treated with acids and enzymes, such as low protein rice (protein adjusted rice), may be used.

  When an enzyme having transglycosylation activity such as α-glucosidase or transglutaminase that transforms α-1,4 bonds into α-1,6 bonds, such as α-glucosidase, is allowed to act on rice, An enzyme activity of 1.5 U or more, preferably 1.5 to 300,000 U, more preferably 15 to 150,000 U, and still more preferably 38 to 1,080 U with respect to 1 g of rice is appropriate. As for enzyme activity, 1 ml of 1 mM α-methyl-D-glucoside was added with 1 ml of 0.02 M acetic acid buffer (pH 5.0), 0.5 ml of enzyme solution was added and allowed to act at 40 ° C. for 60 minutes. The amount of enzyme that produces 1 μg of glucose in 2.5 ml of the reaction solution was defined as 1 U (unit).

  When an enzyme having transglycosylation activity such as α-glucosidase to convert α-1,4 bonds to α-1,6 bonds and transglutaminase are allowed to act on rice, the amount of transglutaminase added is 1 g of raw raw rice The enzyme activity is 0.0001 U or more, preferably 0.0001 to 100 U, more preferably 0.05 to 10 U, and still more preferably 0.05 to 1.35 U. Regarding enzyme activity, benzyloxycarbonyl-L-glutaminylglycine and hydroxylamine were used as substrates, and the hydroxamic acid produced was formed into an iron complex in the presence of trichloroacetic acid, and then the absorbance at 525 nm was measured. The amount of acid is obtained from a calibration curve and the activity is calculated. The amount of enzyme that produces 1 μmol of hydroxamic acid per minute at 37 ° C and pH 6.0 was defined as 1U (unit).

  When producing cooked rice food by acting an enzyme having transglycosylation activity that converts α-1,4 bond to α-1,6 bond and transglutaminase such as α-glucosidase, for example, α-glucosidase is used as raw rice 1.5 g or more per gram, preferably 1.5 to 300,000 U, more preferably 15 to 150,000 U, even more preferably 38 to 1,080 U, and transglutaminase to 1 g of raw raw rice 0.0001 U or more, preferably 0.0001 to 100 U, more preferably 0.05 to 10 U, and even more preferably 0.05 to 1.35 U, may be included in the manufacturing process. In addition, as mentioned above, the order in which each enzyme acts on rice is not particularly limited.

  The ratio of the amount of both enzymes added to the rice food when the enzyme having transglycosylation activity such as α-glucosidase that converts α-1,4 bonds to α-1,6 bonds and transglutaminase is used is as follows: The number of units of an enzyme having transglycosylation activity that converts α-1,4 bonds into α-1,6 bonds is preferably 0.15 U to 200,000 U, and 0.5 U to 50, 000U is more preferable, 90U to 7,500U is further preferable, and 250 to 3,333U is particularly preferable.

  The reaction time of each enzyme is not particularly limited as long as the enzyme can act on the substrate substance, and may be allowed to act for a very short time or conversely for a long time. 5 minutes to 24 hours are preferred. Further, the reaction temperature may be any temperature as long as the enzyme maintains activity, but it is preferable that the reaction temperature be 0 to 80 ° C. as a practical temperature. That is, sufficient reaction time is obtained by passing through a normal rice cooking process.

  α-glucosidase and transglutaminase, excipients such as dextrin, starch, processed starch, seasonings such as animal meat extract, proteins such as plant protein, gluten, egg white, gelatin, casein, protein hydrolysates, protein partial degradation products, Rice food modification by mixing emulsifiers, chelating agents such as citrate and polymerized phosphate, reducing agents such as glutathione and cysteine, and other food additives such as alginic acid, citrus, pigment, acidulant, and flavor. Enzyme preparations can be obtained. The enzyme preparation of the present invention may be in any form of liquid, paste, granule or powder. The amount of each enzyme in the enzyme preparation is more than 0% and less than 100%, but the amount of α-glucosidase is preferably 0.15 U to 200,000 U per 1 U of transglutaminase, and 0.5 U to 50,000 U. Is more preferable, 90U to 7,500U is further preferable, and 250 to 3,333 units are particularly preferable.

  The following examples further illustrate the present invention. The present invention is not limited in any way by these examples.

“Transglucosidase L”, an α-glucosidase that has a transglycosylation ability that converts α-1,4 bonds into α-1,6 bonds, is added to 400 g of fresh rice “Nippon Seiraku Washed Rice”. Amano Enzyme Co., Ltd. (hereinafter TGL) and “Activa” TG (Ajinomoto Co., Inc.) (hereinafter TG), which is a transglutaminase preparation, were added and dissolved, and immersed at room temperature for 1 hour. The amount of each enzyme is as shown in Table 1. After that, the rice cooker "IH Jar Rice Cooker NJ-HS06-S" (Mitsubishi Electric Co., Ltd.) cooked rice, and the cooked rice in the vacuum cooler "Food Cooler CMJ-40" (Miura Protech Co., Ltd.) And cooled to 25 ° C. or lower. About the obtained cooked rice (white rice), after storing for 24 hours immediately after cooling and at 5 degreeC, the range-up was performed and the result of having performed sensory evaluation is shown in Table 1. The sensory evaluation is based on a scoring system from -2 to 2 points, with 0 as the control category prepared without adding TG or TGL, regarding elasticity, stickiness, grain feel, and overall evaluation (preference). The evaluation was performed by 3 people.
Comprehensive evaluation is that the effect of modification by enzyme is large, the balance of texture of white rice such as graininess, hardness, stickiness, looseness, etc. is good and the deterioration with time is suppressed ◎, there is a modification effect ◯, the balance of white rice texture is slightly good ○, there is a modification effect but is not large, △ is a problem with the balance of white rice texture △, the modification effect is insufficient, white rice food The case where there was a problem with the balance of feeling or the case where there was no effect of suppressing deterioration over time was rated as x.

  Although the elasticity, graininess, and looseness were imparted by the TG treatment, the stickiness of the material that was given elasticity and tenacity was lowered by the TGL treatment. On the other hand, when both enzymes were used in combination, a favorable texture with elasticity, stickiness and graininess was obtained, and the looseness was also good. In particular, when the amount of TG added is 0.045 to 0.15 U / raw rice 1 g, and the amount of TGL added 37.5 to 125 U / raw rice 1 g, 250 to 3,333 U / TG 1 U, graininess and elasticity are imparted, It has been clarified that white rice having a preferable texture with moderate stickiness and looseness and suppressed deterioration over time can be obtained.

  640 g of city water is added to 400 g of raw rice “Nippon Seiraku Washed Rice”, and “Transglucosidase L” (manufactured by Amano Enzyme) (hereinafter “TGL”), “Activa” TG (manufactured by Ajinomoto Co., Inc.) which is a transglutaminase preparation (hereinafter “TG”) ) Was added and dissolved, and immersed for 1 hour at room temperature. There were four test sections: a control section where no enzyme was added, a section where only TG was added, a section where only TGL was added, and a group where both TG and TGL were added. The amount of TG added in the category with only TG added was 2.70 U per 1 g of raw rice, the amount of TGL added in the category added only with TGL was 2,160 U per 1 g of fresh rice, The amount of TG added was 1.35 U, and the amount of TGL added was 1,080 U. At this time, the amount of TGL per TG1U is 800U. After that, the rice cooker "IH Jar Rice Cooker NJ-HS06-S" (Mitsubishi Electric Co., Ltd.) cooked rice, and the cooked rice in the vacuum cooler "Food Rapid Cooler CMJ-40" (Miura Protech Co., Ltd.) And cooled to 25 ° C. or lower. About the obtained cooked rice (white rice), after storing at 5 degreeC for 24 hours, range-up was performed and sensory evaluation was performed. The sensory evaluation is from -2 to 2 points, with 0 as the control category prepared without adding TG or TGL, regarding elasticity, stickiness, graininess, looseness, and overall evaluation (preference). The evaluation was performed by 3 people using the rating method. The results are shown in FIG. In addition, based on the results of the category to which only TG was added and the category to which only TGL was added, the theoretical score of the combined addition category was calculated. For example, in the case of the theoretical value of elasticity, only TG has a elasticity score of “1.5” when 2.70 U / g is added, and 1.35 U / g of TG is used in the combined addition zone, “1. 5 × 1.35 / 2.70 = 0.75 ”, while TGL only has a elasticity rating of“ 0.75 ”when 2,160 U / g is added, and 1,080 U / g is used in the combined addition zone Therefore, “0.75 × 1080/2160 = 0.375” is added, and the total is calculated as “0.75 + 0.375 = 1.125”. Therefore, “1.125” is the theoretical value of the elasticity of the combined use group. Using the value calculated in this way, the difference between the theoretical value and the actual score was obtained (FIG. 2). If this value is zero, it means an effect as the theoretical value, that is, an additive effect, and if it is larger than zero, it means that an effect larger than the theoretical value, that is, a synergistic effect is produced.

  As shown in FIG. 1, when only TG is added, elasticity, grain feel and looseness are imparted by TG treatment, but the viscosity decreases. When only TGL is added, elasticity and tenacity are imparted by TGL treatment. The looseness of things decreased. On the other hand, by using both enzymes in combination, it became a preferable texture with elasticity, stickiness, graininess, and looseness. Moreover, as shown in FIG. 2, it was found that all the evaluation items had a synergistic effect. From the above, it was shown that a synergistic effect on the texture can be obtained by using both enzymes in combination with rice food, not TG or TGL alone.

  640 g of city water is added to 400 g of raw rice “Nippon Seiraku Washed Rice”, and “Transglucosidase L” (manufactured by Amano Enzyme) (hereinafter “TGL”), “Activa” TG (manufactured by Ajinomoto Co., Inc.) which is a transglutaminase preparation (hereinafter “TG”) ) Was added and dissolved, and immersed for 1 hour at room temperature. The test categories are as shown in Table 2. After that, the rice cooker "IH Jar Rice Cooker NJ-HS06-S" (Mitsubishi Electric Co., Ltd.) cooked rice, and the cooked rice in the vacuum cooler "Food Rapid Cooler CMJ-40" (Miura Protech Co., Ltd.) And cooled to 25 ° C. or lower. About the obtained cooked rice (white rice), after storing at 5 degreeC for 24 hours, range-up was performed and sensory evaluation was performed. The sensory evaluation is from -2 to 2 points, with 0 as the control category prepared without adding TG or TGL, regarding elasticity, stickiness, graininess, looseness, and overall evaluation (preference). The evaluation was performed by 3 people using the rating method. The added results are shown in FIG. 3 (graph numbers are sample numbers in Table 2). Further, based on the results of the category to which only TG was added and the category to which only TGL was added, the theoretical score of the combined addition category was calculated in the same manner as described in Example 2. For example, in the case of the theoretical value of elasticity in the combined addition zone 6, only TG has a elasticity score of “1.5” when adding 10.00 U / g of fresh rice, and 6 uses TG of 0.60 U / g of fresh rice. Therefore, “1.5 × 0.60 / 10.00 = 0.09”. On the other hand, only TGL has an elasticity rating of “0.5” when 15000U / g of fresh rice is added. Since it is used, “0.5 × 15000/15000 = 0.5” is added, and when these are added, “0.09 + 0.5 = 0.59” is calculated. Therefore, this value is the elasticity theory value of 6. Using the values calculated in this manner, the difference between the theoretical value and the actual score was obtained (FIG. 4, the graph number is the sample number in Table 2). If this value is zero, it means an effect as the theoretical value, that is, an additive effect, and if it is larger than zero, it means that an effect larger than the theoretical value, that is, a synergistic effect is produced.

  As shown in FIG. 3, when only TG is added, elasticity, graininess, and looseness are imparted by TG treatment, but the viscosity decreases. When only TGL is added, elasticity and tenacity are imparted by TGL treatment. The looseness of things decreased. On the other hand, by using both enzymes in combination, it became a preferable texture with elasticity, stickiness, graininess, and looseness. Moreover, as shown in FIG. 4, it was found that all evaluation items have a synergistic effect. From the above, when the addition amount of TGL is 1.5 to 15,000 U / gray rice, the addition amount of TG is 0.0001 to 10 U / gray rice, and the addition ratio of TGL 90 U to 50,000 U per TG 1 U, TGL It was shown that a synergistic effect can be obtained by the combined use of / TG.

560 g of city water is added to 400 g of fresh rice “Hitomebore unwashed rice”, and “Transglucosidase L” (manufactured by Amano Enzyme) (hereinafter “TGL”), “Activa” TG (manufactured by Ajinomoto Co., Inc.) which is a transglutaminase preparation (hereinafter “TG”) ) Was dissolved and soaked at room temperature for 1 hour, and then 2 g of kombu dashi ("Dashi boast" thick kombu dashi made by Ajinomoto Co.) and 2 g of salad oil were added. The amount of each enzyme is as shown in Table 3. Then, it cooked with the rice cooker "IH jar rice cooker NJ-HS06-S" (made by Mitsubishi Electric Corp.), and after cooking, 130g of combined vinegar was added and mixed uniformly. The obtained vinegared rice was cooled to 20 ° C. or less with a vacuum cooler “food quick cooler CMJ-40” (manufactured by Miura Protec Co., Ltd.). Table 3 shows the results of sensory evaluation of the obtained vinegared rice immediately after cooling and after storage at 20 ° C. for 24 hours. The sensory evaluation is from -2 to 2 points with respect to elasticity, stickiness, grain feel, and overall evaluation (preferability), with 0 being the score of the control product prepared without adding TG or TGL. The evaluation was performed by 3 people. Comprehensive evaluation is that the improvement effect by enzyme is large, the texture of vinegared rice such as graininess, hardness, stickiness, looseness, etc. is well balanced, and the deterioration effect is suppressed ◎ Yes, the vinegared rice has a slightly good texture, ○ the improvement effect is not large, the vinegared rice has a slightly problematic balance △, the modification effect is insufficient, Those having problems with the balance of the texture of vinegared rice or those having no effect of suppressing deterioration with time were rated as x.

  Although the elasticity, graininess, and looseness were imparted by the TG treatment, the stickiness of the material that was given elasticity and tenacity was lowered by the TGL treatment. On the other hand, by using both enzymes in combination, a favorable texture with elasticity, stickiness, and graininess was obtained, and the looseness was also good. In particular, when the amount of TG added is 0.045 to 0.15 U / raw rice 1 g, and the amount of TGL added 37.5 to 125 U / raw rice 1 g, 250 to 3,333 U / TG 1 U, graininess and elasticity are imparted, It was revealed that vinegared rice having a preferable texture with moderate stickiness and looseness and suppressed deterioration over time was obtained.

  560 g of city water is added to 400 g of fresh rice “Hitomebore unwashed rice”, and “Transglucosidase L” (manufactured by Amano Enzyme) (hereinafter “TGL”), “Activa” TG (manufactured by Ajinomoto Co., Inc.) which is a transglutaminase preparation (hereinafter “TG”) ) Was added and dissolved, and immersed for 1 hour at room temperature. The test categories are as shown in Table 4. Then, it cooked with the rice cooker "IH jar rice cooker NJ-HS06-S" (made by Mitsubishi Electric Corp.), and after cooking, 130g of combined vinegar was added and mixed uniformly. Thereafter, the cooked rice was cooled to 25 ° C. or less with a vacuum cooler “food rapid cooler CMJ-40” (manufactured by Miura Protech Co., Ltd.). The obtained vinegared rice was subjected to sensory evaluation after being stored at 20 ° C. for 24 hours. The sensory evaluation is from -2 to 2 points, with 0 as the control category prepared without adding TG or TGL, regarding elasticity, stickiness, graininess, looseness, and overall evaluation (preference). The evaluation was performed by 3 people using the rating method. The results are shown in FIG. 5 (graph numbers are sample numbers in Table 4). In addition, based on the results of the category to which only TG was added and the category to which only TGL was added, the theoretical score of the combined addition category was calculated. For example, in the case of the theoretical value of elasticity in the combination addition group 2, the elasticity score when adding 0.104 U / g of fresh rice is “1” for TG only, and 0.080 U / g of raw rice is used in the combination addition group 2 Therefore, “1 × 0.080 / 0.104 = 0.769”, while TGL only has 114U / g of fresh rice and the elasticity score is “0.5”. Since rice g is used, “0.5 × 38/114 = 0.167” is added, and when these are added, “0.769 + 0.167 = 0.936” is calculated. Therefore, this value is the theoretical value of elasticity in the combined use section 2. Using the value calculated in this way, the difference between the theoretical value and the actual score was obtained (FIG. 6, the graph number is the sample number in Table 4). If this value is zero, it means an effect as the theoretical value, that is, an additive effect, and if it is larger than zero, it means that an effect larger than the theoretical value, that is, a synergistic effect is produced.

  As shown in FIG. 5, the elasticity, graininess, and looseness were imparted by TG, but the tenacity of TGL was reduced. On the other hand, by using both enzymes in combination, it became a preferable texture with elasticity, stickiness, graininess, and looseness. Moreover, as shown in FIG. 6, it was found that there is a synergistic effect in the items of elasticity, stickiness, graininess, looseness, and comprehensive evaluation. From the above, it was shown that a synergistic effect on the texture can be obtained for vinegared rice by using both enzymes together, not TG or TGL alone.

  According to the present invention, the quality of cooked rice food can be improved, which is extremely useful in the food field.

It is a sensory evaluation result of white rice. (Example 2) It is a result about the synergistic effect in the sensory evaluation of white rice. (Example 2) It is a sensory evaluation result of white rice. (Example 3) It is a result about the synergistic effect in the sensory evaluation of white rice. (Example 3) It is a sensory evaluation result of vinegared rice. (Example 5) It is a result about the synergistic effect in the sensory evaluation of vinegared rice. (Example 5)

Claims (7)

A method for producing cooked rice food, comprising using 1.5 to 300,000 U of transglucosidase per 1 g of raw raw rice and 0.0001 to 100 U of transglutaminase per 1 g of raw raw rice . Amount of transglucosidase, a raw material raw rice 1g per 15～150,000U, method of claim 1, wherein the addition amount of the transglutaminase is a raw material raw rice 1g per 0.05～10U. The method according to claim 2, wherein the amount of transglucosidase added is 15 to 1,080 U per gram of raw raw rice, and the amount of transglutaminase is 0.05 to 1.35 U per gram of raw raw rice. 4. The method according to claim 1, wherein the amount of transglucosidase added is 0.15 U to 200,000 U per 1 U of transglutaminase. The method according to any one of claims 1 to 3, wherein the amount of transglucosidase added is 90 U to 50,000 U per 1 U of transglutaminase . An enzyme preparation for improving cooked rice food containing transglucosidase and transglutaminase, wherein the transglucosidase content is 0.15 U to 200,000 U per 1 U of transglutaminase . The enzyme preparation according to claim 6, wherein the content of transglucosidase is 90 U to 50,000 U per 1 U of transglutaminase.