JP6614436B2 - Fast-return instant rice and manufacturing method thereof - Google Patents

Description

  The present invention relates to a quick-return instant rice that can be restored in a short time even with water, has a good taste and texture, and has an excellent appearance, and a method for producing the same.

  This type of instant rice is a fast-dried version of cooked rice that can be cooked back in hot water or water without cooking in a microwave oven, etc. It is used as food. Currently, the restoration time of instant rice on the market requires 15 minutes or more with hot water and 60 minutes or more with cold water.

For example, in the instant rice in Patent Document 1, the rice grains are swelled by the expansion drying in the final process and the appearance is good, and the water absorption at the time of restoration is also excellent, but the so-called “pon confectionery” feeling remains and the texture There was a slight difficulty.
Patent Document 2 discloses a method for producing an instant tea product obtained by dissolving an enzyme such as a protease in cooked rice and cooking the rice, cooling the cooked rice to absorb water, and then freeze-drying. The purpose of the present invention is to restore “chazuke”, not “rice”, which places importance on the appearance and texture, and the processing time is longer than that of hot air drying, resulting in high freezing. It is necessary to dry.

JP 2013-51889 A JP-A-9-271332

As described above, the conventional instant rice has problems such as that it takes time to restore, the restoration is relatively quick, the appearance is crushed, and the texture is crumbly and gummy.
Therefore, the present invention provides a quick-return instant rice that can be restored within 5 minutes with hot water and within 20 minutes with cold water, and has a taste, texture and appearance comparable to those of ordinary “rice”, and a method for producing the same. For the purpose.

In order to solve the above problems, the present invention provides:
Pressurized steaming treatment is performed on unimmersed raw rice to form a pregelatinized layer on the surface of the rice grain, and at least one enzyme of amylase and protease is added to the pressurized steamed rice grain Rice is cooked with cooked rice water and the rice grains are completely alphalated, and the rice grains after the rice cooking process are immersed in warm water of 60 to 70 ° C. so that the water content of the rice grains is 70 to 80%. A swelling step for swelling, a primary drying step for drying the swollen rice grains at a relatively high temperature of 115 to 130 ° C. for 20 to 30 minutes to make the moisture content 20 to 25%, and the primary drying step It is a method for producing an instant rice characterized by sequentially providing a secondary drying step of drying the subsequent rice grains at a relatively low temperature of 60 to 90 ° C. for 50 to 60 minutes so that the water content is 10% or less.

  In the method for producing instant rice of the present invention, it is preferable to add an emulsifier together with the enzyme into the cooked rice water.

  In the method for producing instant rice according to the present invention, the swelling step is performed by charging the rice grains cooked in the rice cooking step into a dipping container containing warm water without cooling and transporting the rice grains to the primary drying step while dipping. Good.

According to the method for producing fast-return instant rice of the present invention, by performing pressure steaming on unimmersed raw rice and forming an alpha layer on the surface of the rice grain, the appearance shape is less likely to collapse in the subsequent steps. On the other hand, water absorption into the rice grain is promoted by weakening the binding of the rice grain tissue by amylase and / or protease, which is an enzyme added to the rice cooking water, and alphaization is sufficiently performed in the rice cooking process, making it plump It becomes rice.
Immediately without cooling the cooked rice, a large amount of water is contained in the rice grain by immersing it in an immersion container filled with warm water and swelling it. Since it is weakened, it can be performed more effectively. Moreover, the hot water in a container is hard to cool by throwing the cooked rice immediately after cooking into the said immersion container.
The swollen rice grains rapidly evaporate due to drying with relatively hot hot air in the primary drying process, and a large number of cavities are formed inside the rice grains. This makes it possible to obtain an instant return rice that can be restored within 5 minutes with hot water and within 20 minutes with cold water. In the secondary drying process, the rice grains are gently expanded and dried at a relatively low temperature without actively expanding the rice grains, so that the taste, texture and appearance of the rice are not reduced when restored. , A quick return instant rice having a predetermined water activity or less can be obtained.

  In addition, according to the method for producing fast-return instant rice of the present invention, by adding an emulsifier together with the enzyme in the cooked water, the binding of the rice grains of cooked rice is weakened and handling in the subsequent process is facilitated. , The grain texture of each grain of rice increases, and the texture at the time of restoration improves.

  Furthermore, according to the manufacturing method of the quick return instant rice of this invention, the rice grain cooked in the said rice cooking process is thrown into the immersion container containing warm water, without cooling, and it conveys to the said primary drying process, immersing. So it is efficient.

The manufacturing flow in the manufacturing method of the quick return instant rice of this invention is shown.

Hereinafter, an embodiment of the present invention will be described with reference to a flow of manufacturing a quick return instant rice according to the present invention shown in FIG.
The quick-return instant rice in the carrying of the present invention includes a pressure steaming step (S1), a rice cooking step (S2), a swelling soaking step (S3), a temporary drying step (S4), a secondary drying step (S5) and Manufactured through the core process of single grain / selection process (S6).

(1) Raw material rice In the present invention, polished rice of japonica rice (short grain type) is used as raw material rice. The whiteness of the polished rice is 38% or more, the water content is preferably 11 to 14%, and washing-free rice is preferred.
Here, the non-washed rice refers to rice obtained by adding 15% or less of water or a debonding adhesive to the polished rice, polishing the surface of the polished rice, and removing wrinkles remaining on the polished rice surface. The whiteness is a value measured by receiving reflected light from rice grains, assuming that the dark state is 0 and the whiteness of barium sulfate is 100.

(2) Pressure steaming process (S1)
Next, the raw rice is treated for 0.5 to 2 minutes under pressure and heating steam at a pressure of 0.01 to 0.1 MPa (gauge pressure) and a temperature of 101 to 110 ° C. using a pressure heating kettle. The raw rice is transported by a conveyor or the like, and transported into the pressurizing and heating pot pressurized with saturated steam, thereby forming a pregelatinized film on the surface of the raw rice 0.1 to 0.2 mm, It is possible to prevent boiling when cooking with high moisture in the subsequent process.

(3) Rice cooking process (S2)
The present invention uses raw rice having a relatively low water content and is not washed and soaked, and the increase in water content due to the pressure steaming process is only 4 to 6%. Wearing is difficult to occur.
The raw rice that has been subjected to the pre-cooking process in the pressurized steaming step is sequentially put into a rice cooking container in a rice cooker, and a predetermined amount of rice cooking water is supplied. At least one enzyme of amylase and protease is added to the cooked rice water. The enzyme is added in an amount of 0.07 to 0.6% based on the weight of the raw rice. The cooked water may have an initial temperature of 35 to 40 ° C. For example, if the rice cooker is a rice cooker that cooks every pot, the raw rice can be effectively immersed in the enzyme water in a rice cooker. The soaking treatment weakens the binding of starch and protein cell tissues of the raw rice and promotes water absorption. In the rice cooking process, the raw rice is completely and uniformly pregelatinized, and the moisture content is 62 to 65%. Cook it up.

(4) Swelling dipping process (S3)
The raw rice cooked in the rice cooking step is immediately put into a dipping container containing warm water of 60 to 70 ° C., absorbed by immersing for 30 to 60 minutes and swollen to a moisture content of 70 to 80%, The volume ratio is about 3.5 times that of the raw white rice before the pressure cooking step (S1).
In addition, in the swelling step, the rice cooked rice for each pot of the rice cooker is put into the soaking container, and is swollen while sequentially transporting the soaking container for the primary drying step (S4) in the subsequent process. It is efficient to configure so as to perform immersion.

(5) Primary drying step (S4)
When the swelling soaking step is completed, the soaking container is inverted to discharge the soaked raw material rice onto a net conveyor, the hot water for soaking and the raw rice are separated, and the raw material rice is conveyed into a drying device. The drying method may be hot air drying, superheated steam drying, or microwave drying, but the moisture of the raw rice is rapidly evaporated for 20 to 30 minutes at a relatively high temperature of 115 to 130 ° C. Although the pre-gelatinization of the raw rice has been completed in the swelling soaking step, re-alpha-izing occurs in the primary drying step and the surface is slightly swollen, so that the moisture content of the raw rice becomes 20-25%.

(6) Secondary drying step (S5)
In the secondary drying step that follows the primary drying step, it is slowly finished and dried at a relatively low temperature of 60 to 90 ° C. for 50 to 60 minutes so as not to lower the taste, and the moisture content of the raw rice is reduced to 10% or less. Thus, the water activity AW is 0.45 or less to improve the storage stability.

(6) Single grain / selection process (S6)
After the secondary drying process, the instant rice is processed into a single grain machine where the binding of rice grains is eliminated, and finally, foreign substances and crushed rice are removed by a shifter, optical sorter, etc. Is done.

<Example 1>
As raw material polished rice, 300 g of “Haenuki” produced in Yamagata Prefecture in 2014 with a moisture content of 14% and a whiteness of 40% was prepared. The temperature in the test room was 25 ° C.

  After lightly washing the rice, steam at 105 ° C. was supplied for 30 seconds under a pressure of 0.02 Mpa in a pressure heating kettle. The moisture content of the raw rice was 16%.

  The raw rice after the pressure cooking was stored in a pot of an IH rice cooker, and 600 g of cooked water was supplied and immersed. In the cooked rice water, 2 g (0.7%) of a liquid enzyme containing mirase and protease (Otsuka Pharmaceutical OS-60L) and 1 g (0.3%) of an emulsifier made of soybean-derived lecithin (Otsuka Pharmaceutical OS-77L) Each was added and immersed for 20 minutes at a water temperature of 35 ° C. The moisture content of the raw rice after immersion for 20 minutes was 35%.

  Next, the temperature of the rice cooker was heated and cooked at a water temperature of 100 ° C. The time required for cooking rice was 35 minutes, and then steamed for 20 minutes. The moisture content of the raw rice after steaming was 66%.

  The cooked raw rice was taken out of the kettle and stored in a dipping container, and 65 ° C. dipping water was added until the raw rice was completely submerged, soaking and swelling for 30 minutes. The raw rice after soaking had a moisture content of 75% and the weight was 785 g, which was 2.6 times that of the raw rice before pressure steaming.

The said immersion container was inverted, the raw material rice in this immersion container was discharge | released on the net conveyor, after separating raw material rice and immersion water, the raw material rice was mounted in the net conveyor and conveyed in the drying apparatus. In the drying apparatus, first, primary drying was performed at a hot air temperature of 115 ° C. for 20 minutes, and then secondary drying was performed with hot air of 80 ° C. for 60 minutes to obtain instant rice. The water content of the instant rice was 7%.
The instant rice had a weak binding state between rice grains, and could be easily crushed by hand.

  When 85 cc of hot water at 95 ° C. was added to 50 g of the instant rice, it was restored to rice in 4 to 5 minutes. Moreover, when 85 cc of water at 20 ° C. was added to 50 g of the instant rice, it was restored to rice in 20 minutes. In all cases, the appearance was not disturbed and the taste and texture were both good.

<Example 2>
As raw material rice, 300 g of “Milky Queen” (low amylose rice) produced in Hiroshima Prefecture with a moisture content of 13% and a whiteness of 41% was prepared in 2014. The temperature in the test room was 20 ° C.

  The raw material rice was supplied with steam at 105 ° C. for 60 seconds under a pressure of 0.02 MPa in a pressure heating kettle. The water content of the raw rice after 60 seconds was 16%.

  The pressure-cooked raw rice was stored in a pot of an IH rice cooker, and 435 g of cooked water was supplied and immersed (hydration rate 1.45 times). 2 g of a liquid enzyme containing mirase and protease (Otsuka Pharmaceutical OS-60L) and 2.1 g of an emulsifier consisting of sucrose fatty acid ester (Mitsubishi Chemical Foods S-1170) are added to the cooked rice water, respectively, at a water temperature of 35 ° C. Soaked for 20 minutes. The moisture content of the raw rice after immersion for 20 minutes was 34%.

  20 minutes after immersing the raw rice in the kettle, the temperature of the rice cooker was heated and cooked at a water temperature of 100 ° C. The time required for cooking rice was 35 minutes, and then steamed for 20 minutes. The moisture content of the raw rice after steaming was 62%.

  The cooked raw rice was taken out of the kettle and stored in a dipping container, and 70 ° C. dipping water was added until the raw rice was completely immersed, soaking and swelling for 40 minutes. The raw rice after immersion had a moisture content of 70%, and the weight was 670 g, which was about 2.3 times that of the raw rice before pressure cooking.

The said immersion container was inverted, the raw material rice in this immersion container was discharge | released on the net conveyor, after separating raw material rice and immersion water, the raw material rice was mounted in the net conveyor and conveyed in the drying apparatus. In the drying apparatus, first, primary drying was performed at a hot air temperature of 120 ° C. for 20 minutes, and then secondary drying was performed with hot air of 80 ° C. for 50 minutes to obtain instant rice. The water content of the instant rice was 7%.
The instant rice was weak in the binding state between the rice grains, and could be easily spread by hand.

  When 85 cc of hot water at 95 ° C. was added to 50 g of the instant rice, it was restored to rice in 3 to 3.5 minutes. Moreover, when 85 cc of water at 20 ° C. was added to 50 g of the instant rice, it was restored to rice in 15 minutes. In all cases, the appearance was not disturbed and the taste and texture were both good.

The method for producing quick return instant rice of the present invention can be restored to rice in a shorter time than conventional, and is very useful as an emergency food in a disaster, mountain climbing, camping, etc. .

Claims (3)

  Pressurized steaming treatment is performed on unimmersed raw rice to form a pregelatinized layer on the surface of the rice grain, and at least one enzyme of amylase and protease is added to the pressurized steamed rice grain Rice is cooked with cooked rice water and the rice grains are completely alphalated, and the rice grains after the rice cooking process are immersed in warm water of 60 to 70 ° C. so that the water content of the rice grains is 70 to 80%. A swelling step for swelling, a primary drying step for drying the swollen rice grains at a relatively high temperature of 115 to 130 ° C. for 20 to 30 minutes to make the moisture content 20 to 25%, and the primary drying step A secondary drying step of drying the subsequent rice grains at a relatively low temperature of 60 to 90 ° C. for 50 to 60 minutes to obtain a moisture content of 10% or less.   The said rice cooking process WHEREIN: The manufacturing method of the quick return instant rice of Claim 1 formed by adding an emulsifier to the said rice cooking water with the said at least 1 type of enzyme.   The quick-return instant rice according to claim 1 or 2, wherein the swelling step is performed by sequentially putting the cooked rice cooked in the rice cooking step into a dipping container containing warm water and transporting it to the primary drying step while dipping. Manufacturing method.

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