JP3568520B2 - Cold water restoring instant cooked rice and method for producing the same - Google Patents

Description

【００３１】
【表２】

【００３２】
表１及び表２の復元テストの結果より分かるように、実施例１〜３に係る乾燥米飯は、水を加えて２５分、お湯を加えて５分以内で柔らかく、粘りが強い良好な食感に復元した。他方、比較例１の日本晴を用いたものは、復元までに水では６０分、お湯でも１５分かかり、粘り無くぼそぼそしたやや硬い食感であった。比較例２のコシヒカリについても、復元までに水では４０分、お湯でも８分かかり、日本晴より粘りはあるが、硬い食感であった。
【００３３】
【発明の効果】
本発明によれば、低アミロース米を使用することで、冷水復元性を有すると共に、復元時に粘りが強く、柔らかく復元し、食味が向上する乾燥米飯を得ることができる。精米を炊飯乾燥した、乾燥米飯を焙煎するだけでは復元時の粘りが無いやや硬いものであったが、低アミロースを使用することにより、復元時の吸水性も促進され、焙煎品に見られるパサツキの無い粘りのある、食感が良い米飯となる。
【図面の簡単な説明】
【図１】
実施例１〜３並びに比較例１及び２に係る乾燥米飯についての、給水温度と復元時間の関係を示した図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to instant rice with a white color and good taste, which can be easily eaten in a short time even with cold water, and a method for producing the rice.
[0002]
[Prior art]
Instant rice is rice that has been pregelatinized, such as by cooking non-glutinous rice, and then dried by means of hot air or the like. When hot water or water is added, the rice returns to rice and can be eaten without the need for boiling. However, conventional instant cooked rice has a texture similar to that of ordinary cooked rice, but the time required for restoration is about 20 minutes using hot water, and it takes a considerable amount of time to be able to eat.
[0003]
In order to solve such a problem, various improvements have been proposed in recent years. For example, Japanese Patent Application Laid-Open No. Sho 51-148051 proposes a technique in which rice is pregelatinized, washed with lukewarm water, completely dried, and expanded with a heated metal plate. By washing after cooking, the rice has an inferior taste (poor taste, rough texture) as rice at the time of restoration, and is of a level that is difficult to commercialize. Further, Japanese Patent Publication No. 52-46298 proposes a technique in which rice after pregelatinization is pressed and then expanded after pressing, but the apparent specific gravity after expansion is reduced by pressing and becomes faster, but after restoration. The elasticity of rice, so-called stiffness, is lost, and the texture becomes inferior.
[0004]
[Problems to be solved by the invention]
As described above, the conventional instant cooked rice has a drawback that it takes a long time to restore or has a bad texture. Therefore, the present invention does not require time for restoration, and particularly, restoration time is short even with cold water instead of hot water (within 5 minutes with hot water and within 25 minutes with cold water), and the color tone is as white as that of ordinary rice. It is an object of the present invention to provide an instant cooked rice having a good texture and a method for producing the same.
[0005]
[Means for Solving the Problems]
The present invention (1) is a process for producing an instant cooked rice comprising a step of pregelatinizing non-glutinous rice as a raw material to obtain pregelatinized rice and a step of drying the pregelatinized rice to obtain dried pregelatinized rice. And low amylose rice having an amylose content of 15% by weight or less.
[0006]
Further, the present invention (2) is the method according to the above-mentioned invention (1), wherein the polishing accuracy of low amylose rice is 80 to 90%.
[0007]
Further, the present invention (3) is the method according to the above invention (1) or (2), wherein the pregelatinizing step is to cook rice so that the water content of the pregelatinized rice is 60 to 70% by weight.
[0008]
Further, the present invention (4) further comprises a step of roasting the dried pregelatinized rice to obtain puffed dried pregelatinized rice after the drying step, wherein the method according to any one of the above inventions (1) to (3). It is.
[0009]
Further, the present invention (5) is the method according to the above invention (4), wherein the roasting temperature is 120 to 250 ° C.
[0010]
Further, the present invention (6) is the method according to the invention (4) or (5), wherein the specific volume of the puffed dried pregelatinized rice after the roasting step is 2 to 5 (ml / g).
[0011]
Further, the present invention (7) is the method according to any one of the above inventions (4) to (6), further comprising a humidity control step of adjusting the water content of the dried pregelatinized rice before the roasting step. .
[0012]
The invention (8) is the method according to the invention (7), wherein the moisture content is 7 to 15% by weight.
[0013]
Further, the present invention (9) provides the method according to any one of the above inventions (1) to (8), wherein in any one of the steps, a seasoning such as salt, oil and fat, amino acid, and an additive such as a flavor are used. is there.
[0014]
Further, the present invention (10) is an instant cooked rice produced by the method according to any one of the inventions (1) to (9).
[0015]
Further, the present invention (12) is the instant cooked rice of the invention (11), which has cold water restoring property.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The most important feature of the present invention is that low-amylose rice having an amylose content of 15% by weight or less (preferably 5 to 15% by weight, more preferably 5 to 13% by weight) is used as the non-glutinous rice as a raw material. That is. The amylose content referred to in the present specification is a weight percentage of the amount of amylose to the total amount of starch (amylose + amylopectin) and refers to a value measured by an iodine colorimetric colorimetric method (for example, Food Analysis Handbook, 2nd edition) See T. Ohara et al.). As such low amylose rice, as long as the polished rice has an amylose content of 15% by weight or less, irrespective of its varieties and production areas, for example, Aya, Hanabusa, Ayahime, Snow Pearl, Silky Pearl, Freshly Brewed, Asatsuyu , Soft 158, Milky Queen, and Yukomachi. Further, various types of milled rice having different milling degrees, such as low-protein rice, germ-milled rice, etc., and non-washed rice with higher milling accuracy may be used, and preferably, milled rice having a milling accuracy of 80 to 90%.
[0017]
Hereinafter, a method for producing instant cooked rice according to the present invention will be described. The method includes a step of pregelatinizing low-amylose rice as a raw material to obtain pregelatinized rice. Here, as a suitable means for pregelatinizing rice, rice is put into a container, and rice and water are put into a container to cook rice by heat such as electricity or gas (batch type), or the above treatment or steaming (rice is put into a wire mesh). Cooked on rice by arranging them uniformly in a layer on a belt conveyor and continuously flowing in the vapor phase). The term “pregelatinized rice” as used herein means rice in which starch is pregelatinized (for example, freshly cooked rice), and is a concept that does not include dried rice.
[0018]
The moisture content of the pregelatinized rice obtained here is adjusted according to the eating condition at the time of restoration from the rice cooking state of the offending degree to the cooking moisture of the porridge, preferably 55 to 75% by weight, more preferably. Is adjusted to 60-70% by weight. In addition, the water content (including the moisture control moisture content) in this specification refers to a value measured by an infrared moisture meter.
[0019]
The method further includes drying the pregelatinized rice to obtain a dry pregelatinized rice. The drying step is not particularly limited, and hot air drying, vacuum drying, freeze drying, high frequency drying, solar drying and the like can be employed. However, it is preferably hot-air drying, and more specifically, drying at a temperature of 60 to 100 ° C. for about 1 to 2 hours. In addition, examples of the drying means include band drying and shelf drying. Although the degree of drying is low, from the viewpoint of stability of alpha starch, thermal denaturation of protein, deterioration of resilience due to drying deformation, and sizing of individual grains, the moisture content of dried pregelatinized rice is 6%. It is preferable to dry to about 15%.
[0020]
Further, the method preferably comprises, after the drying step, roasting the dried pregelatinized rice to obtain puffed dry pregelatinized rice. Here, "puffing" refers to an operation of forming cavities inside dried pregelatinized rice in order to increase water absorption. In this step, roasting is preferably performed at 120 to 250 ° C, more preferably 140 to 220 ° C, for 30 to 120 seconds. From the viewpoints of restoration time, prevention of destruction of rice grain structure, prevention of collapse due to excessive swelling, and the like, the specific volume after roasting (ml / g) is preferably 2 to 5. The “specific volume” in the present specification refers to a value measured by a Brawell grain meter.
[0021]
In addition, before the roasting step, if necessary, a moisture conditioning step (tempering step) for adjusting the moisture content of the dried pregelatinized rice to be uniform may be further included. In particular, from the viewpoint of handling, the moisture content of the dried pregelatinized rice is adjusted by taking a method of adjusting the humidity (for example, about 2% by weight) after once drying it (for example, about 2% by weight lower). This is preferable because it is easy to equalize. Here, as the humidity control means, for example, dry pregelatinized rice is put in a tank, and air having a constant high humidity and temperature is circulated by air (convection) to gradually reduce the water content of the dry pregelatinized rice. There is a method of raising. The moisture content varies depending on the type and capacity of the roaster, but is preferably 7 to 15% by weight.
[0022]
In addition, in the step of obtaining pregelatinized rice, in the step of obtaining dried pregelatinized rice and puffed pregelatinized rice, additives such as salt, oils and fats, amino acids and other seasonings, flavors and the like may be added.
[0023]
The instant cooked rice thus obtained has cold water restoring properties. Here, the term “cold water restoring property” refers to a property of being restored within 30 minutes (preferably 25 minutes, more preferably 20 minutes) with cold water (temperature: 20 ° C.). Instant cooked rice can be eaten by returning it with twice the weight of water.
[0024]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to these examples.
[0025]
Example 1 and Comparative Example 1
Milky queen milled rice of low amylose rice (88% milled, 12% amylose content) was washed with rice and immersed for 2 hours. This was cooked in a conventional manner to obtain cooked rice with a cooked water content of 65%. Next, it was spread on a mesh of a pand-type dryer and dried to a water content of 10% with hot air at 80 ° C. This was sized to adjust the particle size one by one, and then moisture was adjusted so that the water content before roasting became uniform, and the water content was reduced to 13%. Thereafter, heating was performed at 180 ° C. for 60 seconds by a fluidized roaster to obtain instant cooked rice having a specific volume of 3.5. Nipponbare (88% milled product, amylose content 20%) was treated under the same conditions to obtain a sample having a specific volume of 2.5.
[0026]
Example 2
Milky Queen old rice (85% milled product, amylose content 14%) was washed with rice, immersed for 2 hours and cooked to obtain cooked rice having a cooked water content of 60%. This was spread on a net of a drier and dried with hot air at 80 ° C. to a moisture content of 11%. These were sieved one by one and conditioned to 14% moisture before roasting. Thereafter, the sample was heated and roasted at 200 ° C. for 50 seconds by a roasting machine to obtain a sample having a specific volume of 3.2.
[0027]
Example 3
After washing the low-amylose rice snow pearl milled rice (88% milled product, amylose content 8%), the rice was immersed for 2 hours and cooked to obtain cooked rice having a cooked water content of 60%. This was dried with hot air at 80 ° C. to a moisture content of 12%. These were sieved one by one and conditioned to 14% moisture before roasting. Thereafter, the sample was heated and roasted at 200 ° C. for 50 seconds by a roasting machine to obtain a sample having a specific volume of 3.3.
[0028]
Comparative Example 2
Koshihikari (85% milled product, amylose content 17%) was washed with rice, immersed for 2 hours, and cooked to obtain cooked rice having a cooked water content of 70%. This was spread on a net of a dryer and dried with hot air at 85 ° C. to a water content of 10%. This was sieved one by one, and the humidity was adjusted to 13% before roasting. Thereafter, the sample was heated at 200 ° C. for 50 seconds by a roasting machine and roasting was performed to obtain a sample having a specific volume of 2.7.
[0029]
A restoration test was performed by adding 100 ml of boiling water and 20 ° C. water to 40 g of the instant cooked rice obtained in the examples and comparative examples. The results are shown in Tables 1 and 2 and FIG.
[0030]
[Table 1]

[0031]
[Table 2]

[0032]
As can be seen from the results of the restoration tests in Tables 1 and 2, the dried cooked rice according to Examples 1 to 3 had a soft, sticky and good texture within 25 minutes after adding water and within 5 minutes after adding hot water. Restored. On the other hand, in the case of using Nipponbare of Comparative Example 1, it took 60 minutes with water and 15 minutes with hot water until restoration, and it had a sticky and slightly hard texture. The Koshihikari of Comparative Example 2 also took 40 minutes with water and 8 minutes with hot water until restoration, and although it was more sticky than Nipponbare, it had a hard texture.
[0033]
【The invention's effect】
According to the present invention, by using low amylose rice, it is possible to obtain dry cooked rice which has cold water restoring property, has strong stickiness upon restoration, is softly restored, and has improved taste. The rice was cooked and dried, and the dried rice was only roasted, which did not have the stickiness at the time of restoration. It is a sticky rice with good texture and no pasagi.
[Brief description of the drawings]
FIG.
It is the figure which showed the relationship between the supply water temperature and the restoring time about the dry cooked rice concerning Examples 1-3 and Comparative Examples 1 and 2.

Claims (11)

In a method of producing an instant cooked rice including a step of pregelatinizing non-glutinous rice as a raw material to obtain a pregelatinized rice, and a step of drying the pregelatinized rice to obtain a dried pregelatinized rice,
(1) Low-amylose rice having an amylose content of 15% by weight or less is used as non-glutinous rice as a raw material,
(2) The milling accuracy of low amylose rice is 80-90%, and
(3) the pregelatinizing step is to adjust the water content of the pregelatinized rice to be 55 to 75% by weight ;
Method. The method according to claim 1, wherein the milling accuracy of the low amylose rice is 80 to 88% . The method according to claim 1 or 2, wherein the pregelatinizing step adjusts the water content of the pregelatinized rice to be 60 to 70% by weight. The method according to any one of claims 1 to 3, further comprising, after the drying step, roasting the dried pregelatinized rice to obtain puffed dried pregelatinized rice. The method according to claim 4, wherein the roasting temperature is 120-250C. The method according to claim 4 or 5, wherein the specific volume of the puffed dried pregelatinized rice after the roasting step is 2 to 5 (ml / g). The method according to any one of claims 4 to 6, further comprising, before the roasting step, a humidity control step of adjusting the water content of the dried pregelatinized rice. The method according to claim 7, wherein the moisture conditioning moisture is 7 to 15% by weight. The method according to any one of claims 1 to 8, wherein in any one of the steps, a seasoning such as salt, oil and fat, an amino acid, and an additive such as a flavor are used. Instant rice cooked by the method according to any one of claims 1 to 9. The instant cooked rice according to claim 10, which is cold water restorable.

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