JPH06141796A - Production of frozen cooked rice - Google Patents

Abstract

PURPOSE:To solve problems such that the wet touch of cooked rice can not be regenerated when frozen cooked rice produced by a conventional method is thawed with a microwave oven and that the appearance, texture, etc., to the cooked rice are not excellent after thawed. CONSTITUTION:This method for producing frozen cooked rice is characterized by once aging cooked rice and subsequently freezing the aged cooked rice.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing frozen cooked rice, in which the fluffy texture and rice grain texture of freshly cooked rice are well reproduced and the appearance and texture after thawing are excellent.

[0002]

2. Description of the Related Art Frozen cooked rice has been conventionally manufactured by various methods. A conventional method for producing frozen cooked rice is to cook rice once and then freeze it by a method such as liquefied carbon dioxide, liquid nitrogen, or air blast. With conventional frozen cooked rice frozen using these methods, moisture evaporates during the manufacturing process, and the moist feeling and graininess of rice that cannot be reproduced as with freshly cooked rice at the time of thawing the microwave oven cannot be reproduced. I didn't want to say that it was excellent in terms of quality.
As means for solving these problems, a method of adding gums during rice cooking (JP-A-52-156948), immersing once frozen food in water, or spraying water to form an ice layer Method (JP-A-1-196264), a method of spraying water on a food filled in a container or a molded food and then freezing it (JP-A-3-2546).
No. 51) is known.

However, the method described in JP-A No. 52-156948 does not sufficiently reproduce the texture of freshly cooked cooked rice because the gelled film solidifies on the surface of cooked rice grains. Further, in the method described in JP-A-1-196264, the heat of coagulation of water is transferred to the frozen food during the production of the ice layer, so that the food is partially thawed and denatured. JP-A-1-196264, 3-
In any of the methods described in Japanese Patent No. 254651, since the ice is directly attached to the rice grains, there is a problem that the tissue is likely to be destroyed due to the growth of ice crystals with the temperature of the food.

In the production, the method of immersing in water as disclosed in JP-A-1-196264 has a drawback that the amount of attached water cannot be controlled.
In the method of spraying water as disclosed in JP-A-1-196264 and JP-A-3-254651, the object may be a molded product such as onigiri or a product in a container, but rose-shaped or compound-grained cooked rice When the target is small like in the above, if water is sprayed with water, unevenness may occur or rice grains may bind to each other. Due to these factors, good quality could not be obtained.

[0005]

The object of the present invention is to solve the problems of the above conventional manufacturing method, that is, when the frozen cooked rice manufactured by the conventional method is thawed in a microwave oven, the moist feeling of rice cannot be reproduced, In addition, it is difficult to say that the appearance and texture of rice after thawing is excellent, and it is to solve the problems.

[0006]

Means for Solving the Problems As a result of intensive studies aimed at solving the problems of the frozen cooked rice produced by such a conventional method, the present inventors have made rice aged and then frozen. As a result, it was found that the moist feeling and the rice grain feeling can be reproduced even after thawing in the microwave oven, and the present invention has been completed.

That is, the present invention is a frozen cooked rice characterized by aging cooked rice once. Further, the present invention is the above-mentioned frozen cooked rice, characterized in that starch having a gelatinization degree of 100% is converted into starch having a gelatinization degree of 50 to 98%.

The origin, type and quality of the rice used as the raw material of the frozen cooked rice of the present invention are not critical, and include glutinous rice, glutinous rice, intermediate glutinous rice, and indica seeds. To cook rice made from these ingredients,
A conventional method may be followed, and specifically, for example, there is a method in which water is added 1.4 times as much as the weight of rice to the raw rice and the rice is cooked in a rice cooker.

The method of freezing cooked rice may be a normal freezing method such as a liquefied carbon dioxide method, a liquid nitrogen method, an air blast method, a contact freeze method, or a combination of these methods.

The present invention is suitable not only for the rice that has been frozen in the past, but also for cooked rice that has been frozen by multiple grains, cooked rice that has been frozen in the form of a plate, and cooked rice produced by any freezing method. Have a significant effect.

When rice is cooked, starch such as rice flour, corn starch and wheat flour, sugars such as arabia gum, guar gum and tragacanth, and proteins such as gelatin and albumin may be mixed.

The temperature for aging the cooked rice is such that the cooked rice is sufficiently cooled and does not freeze, that is, -3 to.
It is carried out at + 30 ° C, preferably in the range of -3 to + 5 ° C. The time required for aging the cooked rice varies depending on the temperature at which aging is performed, but it is the time required for converting starch having a gelatinization degree of 100% into starch having a gelatinization degree of 50 to 98%. Since it is desirable that the aging of cooked rice progresses further, it is preferable that the aging treatment is performed at a lower temperature and for a longer time within a range where the gelatinization degree falls within the above range.

It is preferable that the time required to reach a predetermined refrigerating (aging) temperature is short, and cooked cooked rice is blown with a freezer or the like at -20 ° C at a predetermined temperature, that is, -3 to + 30 ° C, preferably -3 to +5. After cooling to ℃, the temperature is maintained and aging is performed. That is, rather than gradually cooling cooked cooked rice by cooling or the like to reach the refrigeration (aging) temperature, aging can be performed more efficiently in a short time by reaching the refrigeration (aging) temperature at once as described above.

[0014]

EXAMPLES The present invention will be described more specifically below with reference to examples.

(Example 1) 1.4% by weight of water was added to 100% non-glutinous rice, and the rice was cooked in an electric rice cooker. Then, the rice was spread on a tray to a thickness of about 3 cm and wrapped to -40.
The product temperature was lowered to 0 ° C. by rapidly cooling it for 10 minutes with an air blast type freezer at 0 ° C. After that, the rice was transferred to a refrigerator at 0 ° C. and refrigerated for 1 hour. Then, it was frozen again at -20 ° C with an air blast type freezer at -20 ° C. After freezing, 200 g of rice was taken out and heated in a 500 W microwave oven for 4 minutes. The moist feeling and rice grain feeling of this restored rice were immediately evaluated by a sensory test (n = 5).
For control of the sensory test, immediately after cooking rice, rice frozen at −20 ° C. and heated in a microwave oven of 500 W for 4 minutes was used. As shown in Table 1, the samples showed better results in hardness and rice grain feeling.

[0016]

[Table 1] The average of the results of a 5-point evaluation with a control of 3 points by a panel of 3 persons. (5 points: good ~ 3 points:
Normal to 1 point: bad)

(Example 2) Rice containing 80% glutinous rice and 20% glutinous rice was soaked for 1 hour, and then steamed for 1 hour while water was sprinkled three times on the way. The obtained rice flour was filled in a molding machine having a ball-shaped hole having a size corresponding to 5 g of rice, stored in an incubator at 20 ° C. for 24 hours, and then rapidly frozen in liquid nitrogen. A 200 g sample obtained by freezing in this manner was thawed for 4 minutes in a 500 W microwave oven, and then the rice was quickly taken out, and the texture after restoration was evaluated by a sensory test (n = 5). For the control of sensory test, immediately after the steamed rice was steamed, it was immediately frozen in liquid nitrogen.
As shown in Table 2, the samples showed better results in hardness and rice grain feeling.

[0018]

[Table 2] The average of the results of a 5-point evaluation with a control of 3 points by a panel of 3 persons. (5 points: good ~ 3 points:
Normal to 1 point: bad)

(Example 3) 1.4% by weight of water was added to 100% non-glutinous rice, and rice cooked in an electric rice cooker was thinly spread to a thickness of about 1 cm and then air-blasted in a freezer. It was refrigerated at 0 ° C. for 10 hours and then frozen in a contact freezer at −40 ° C. for about 1 hour to obtain plate-shaped frozen white rice. After 200 g of the frozen sample thus obtained was thawed in a microwave oven of 500 W for 4 minutes, the rice was immediately taken out, and the restorability was subjected to a sensory test (n =
It was evaluated according to 5). For the control of sensory test, frozen cooked rice which was just frozen in a contact freezer without aging treatment was used. As shown in Table 3, the sample showed better results in hardness and rice grain feeling.

[0020]

[Table 3] The average of the results of a 5-point evaluation with a control of 3 points by a panel of 3 persons. (5 points: good ~ 3 points:
Normal to 1 point: bad)

(Example 4) 100% of Indica rice was used to add 1.2 times water in a gas pot to cook rice. Salt when cooking rice,
Seasonings such as pepper and bouillon, carrots, peppers,
Beef was added and it was made into pilaf. The obtained pilaf has a temperature of -20 ° C.
30 minutes in the freezer where the cold air circulates, and the product temperature is 20 ℃
I chose After that, it was refrigerated in an incubator at 20 ° C. for 5 hours. Then, it was frozen in an air blast freezer at -40 ° C. The obtained sample was thawed in a microwave oven of 500 W for 4 minutes and evaluated by sensory evaluation. As a control, one that was frozen at -40 ° C without aging treatment was used. As a result, as shown in Table 4, the samples showed better results in hardness and rice grain feeling.

[0022]

[Table 4] The average of the results of a 5-point evaluation with a control of 3 points by a panel of 3 persons. (5 points: good ~ 3 points:
Normal to 1 point: bad)

(Embodiment 5) After adding 1.3 times the weight ratio of water to 100% non-glutinous rice and cooking with an electric rice cooker,
The sample was rapidly cooled to 5 ° C at once with a freezer at 20 ° C, and then stored in an incubator at 5 ° C to prepare samples having different aging (refrigeration) times. Then, each sample was frozen with an air blast freezer at -40 ° C. The obtained frozen cooked rice was heated in a microwave oven of 500 W and then taken out, and the texture of the restored rice was immediately evaluated by a sensory test (n = 4). As a control for the sensory test, the one frozen at −40 ° C. without aging treatment was used. As a result, as shown in Table 5, those having a long cooling time were shown to have a good texture after thawing in a microwave oven.
The reason why the long cooling time showed good results is considered to be that the aging proceeded more because it was stored at low temperature for a longer time. Further, it was also shown that those having a good texture after thawing in a microwave oven did not become hard even after 5 minutes and 10 minutes after thawing, and the good texture could be maintained for a long time. Further, it has been found that those aged for 5 hours or more are preferable to show particularly good texture.

[0024]

[Table 5] An average of the results of a 5-point evaluation with a control of 3 points by a panel of 4 people. (5 points: good ~ 3 points:
Normal to 1 point: bad)

(Example 6) 1.3% by weight of water was added to 100% non-glutinous rice and the rice was cooked in an electric rice cooker, and then the cooling temperature was set to 5 ° C or 20 ° C. The rice was stored for 5 hours. Then, it frozen with the air blast freezer of -40 degreeC, and obtained the sample of frozen cooked rice. The obtained frozen cooked rice was heated in a microwave oven of 500 W and then taken out, and the texture of the restored rice was immediately evaluated by a sensory test (n = 3). As a control for the sensory test, the one frozen at −40 ° C. without aging treatment was used. As a result, as shown in Table 6, it was found that the one having a lower cooling temperature had a better texture. The reason why the one with a low cooling temperature exhibited a good texture is considered to be that the aging proceeded more because it was stored at a lower temperature.

[0026]

[Table 6] The average of the results of a 5-point evaluation with a control of 3 points by a panel of 3 persons. (5 points: good ~ 3 points:
Normal to 1 point: bad)

[0027]

EFFECTS OF THE INVENTION According to the present invention, when frozen rice is thawed in a microwave oven, good moisturizing feeling and rice grain feeling can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenju Chiba 1222 Yoshida, Oizumi-cho, Ora-gun, Gunma Prefecture Inside Ajinomoto Frozen Foods Co., Inc. Frozen Foods Research Laboratory (72) Inventor, Yuji Arata Gunra Prefecture 1222 Yoshida, Izumi-machi, Ajinomoto Frozen Foods Co., Inc.

Claims (2)

[Claims] 1. A method for producing frozen cooked rice, which comprises aging cooked rice and then freezing it. 2. The frozen cooked rice according to claim 1, wherein the aging converts starch having a gelatinization degree of 100% into starch having a gelatinization degree of 50 to 98%.