JPS5851749B2 - How to make instant rice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing instant rice that can be restored to cooked rice having the same taste and texture as cooked rice in a very short time by simply adding boiling water.

Recently, as people's eating habits have become more instant, many foods have become instant and are now available on the market.

On the other hand, research and development has been carried out on cooked rice, which is the staple food of the Japanese people, but it has not been possible to obtain a satisfactory product due to many difficulties in cooking methods, quality, storage stability, etc.

The biggest reason for this is that Japanese people have had rice as their staple food since ancient times, and although they have a better sense of the quality of rice than other foods, they are restoring traditional instant rice. The taste and texture of the resulting rice is clearly inferior to that of normally cooked rice.

In other words, the products obtained by restoring conventional instant rice are either too hard or too soft, lacking the desirable elasticity characteristic of cooked rice, or too elastic, giving it a rubber-like texture. The taste and texture are significantly different from cooked rice.

The biggest reason for this can be said to be that in conventional instant rice, only the instantization process was emphasized, and the gelatinization process was neglected.

In view of these points, the present inventors conducted various studies and realized that the conventional gelatinization process alone was insufficient as a gelatinization method for producing instant rice, and conducted further research. As a result, the present invention was completed.

That is, the present invention is a method for producing instant rice, which is characterized by steaming rice until it is barely cooked, rolling it, adding water, steaming it again to fully gelatinize it, and further drying it and then puffing it up.

Each step of the method of the present invention will be explained below.

゛Any rice can be used as raw material, regardless of its type or quality.

For example, any rice may be used, such as domestically produced rice, overseas produced rice, old rice, new rice, etc.

During gelatinization, it is preferable that the raw rice is first soaked in water.

The dipping may be performed by a method known per se.

For example, the immersion water may be water that has been heated to about the same temperature as hot water,
Cold water is also fine.

The immersion time is 1 hour or more, and the content of immersion water is 30-35
Preferably it is w/w%.

During the soaking process, appropriate natural products, additives, seasonings, various amino acids (e.g. cysteine, cystine, lysine, threonine, methionine), chemical seasonings (e.g. monosodium glutamate, 5'-ribonucleotide), Natural seasonings (e.g. beef extract, bokeh extract), sweeteners such as salt, sugar, glucose, fructose, phosphates (e.g. sodium phosphate, disodium phosphate), polymerized or condensed phosphates (e.g., sodium polyphosphate, sodium pyrophosphate, sodium metaphosphate), sorbitol,
Enzymes (eg, amylase, protease), dilute acids or their salts (eg, dilute hydrochloric acid, citric acid, sodium citrate), etc. may be added to the immersion water.

To steam rice to the point of raw boiling, for example, soak rice in water for about 15 hours, drain the water, and then add 0-0.8 kg/crA.
Steam for about 10 to 30 minutes using steam.

The water content of rice steamed under such conditions is about 30 to 35% by weight, and the core of the rice has not yet been highly gelatinized and is still in a raw state.

The rice that has been steamed to the point of being barely cooked is then rolled.

In this case, it is desirable to cool the steamed rice to about room temperature by blowing cold air for about 10 to 40 seconds for about 5 minutes, and at the same time roll the rice grains so that they are separated one by one.

Examples of the rolling method include passing through a gap between rolls, rolling with a metal plate, and the like.

For industrial production, it is advantageous to use a method in which the material is passed through a roll gap of 0.1 to 0.6 mm.

Other rolling conditions are in accordance with conventional methods.

After the rolling process is completed, water is added to the resulting rice.

This addition of water is carried out by, for example, adding a predetermined amount of water and mixing the rice grains so that the moisture content of each rice grain is equal, so that the added water is completely absorbed into the rice grains.

The amount of water to be added is 0.1 to 0.0 times the amount of raw rice.
About 4 times is preferable from the viewpoint of product quality and yield.

After adding water and allowing the rice grains to completely absorb water, it is again 0 to 0.8.
Steam for about 15 to 30 minutes with steam of kg/lyA.

Steamed rice has a water content of about 35 to 50% by weight and has been sufficiently gelatinized.

Sufficiently gelatinized refers to a state in which the core of the rice is highly gelatinized, the starch is highly digestible, and the rice grains are extremely soft.

The gelatinization of rice is performed in the above manner.

Preferably, a surfactant or/and oil is present at any stage of this gelatinization process.

The amount thereof is preferably about 0.1 to 1.0% by weight based on the raw rice.

The surfactant is preferably a nonionic surfactant used in foods, such as glycerin fatty acid esters (e.g., Emulgy (manufactured by Narita Pharmaceutical Co., Ltd.)), sucrose fatty acid esters (e.g., DK esters (Narita Pharmaceutical Co., Ltd.)), etc. Ichi Kogyo Pharmaceutical■
sorbitan fatty acid esters [e.g., Span 60 (
Manufactured by Kao Atlas ■, etc.

The oils include animal oils and vegetable oils,
The animal fats and oils are preferably auxiliary animal fats and oils, such as beef tallow and pork fat.

The vegetable oil is preferably a semi-drying vegetable oil, such as cottonseed oil or soybean oil.

The thus gelatinized rice is further dried and then expanded.

This drying may be carried out by hot air drying at about 60 to 100° C. so that the water content of the rice can be about 8 to 20% by weight.

However, in this case, it should be noted that if the water content is less than or more than about 8 to 20% by weight, it will be difficult to effectively achieve the purpose of the present invention.

As shown in Experimental Example 2, the above-mentioned highly pregelatinized process, main drying process, and next high-temperature hot air treatment process are closely related to each other. If the moisture content during treatment is outside the above range, the quality of the finished product is likely to deteriorate, making it difficult to achieve the object of the present invention.

The swelling operation is carried out by bringing the rice grains into contact with high-temperature hot air.

The temperature of the high temperature hot air is about 150 to 300°C, more preferably about 180 to 250°C.

The contact time with the high-temperature hot air is preferably short, for example about 10 to 40 seconds.

Preferably, the swelling results in a moisture content of 4 to 7 (w/w)%.

For this high-temperature hot air treatment, any appropriate method may be adopted as long as the object of the present invention can be achieved.

On the other hand, rice is swollen by high-temperature hot air treatment and has a lighter specific gravity, so if the processing equipment, for example, introduces high-temperature hot air from the bottom of a cylinder, the swollen rice will fly out due to its lower specific gravity.

Continuous production is possible if this is mechanically separated.

Next, the expanded rice is cooled to about room temperature.

This operation can be carried out in a conventional manner, that is, by sending cold air (for example, cold air of 40° C. or lower).

The present invention rolls rice grains during the gelatinization process for the purpose of sufficient and high gelatinization, and the products made by the method of the present invention are sufficiently and highly gelatinized, and as a result,
The resulting instant rice not only has good reconstitution properties, but the reconstituted rice has almost the same taste and texture as normally cooked rice.

The instant rice obtained according to the present invention can be easily reconstituted into boiled rice by adding boiling water and leaving it for a very short time (for example, about 10 to 30 seconds), then removing the hot water, sealing it tightly, and using Domura Sudage for about 5 minutes. .

If you compare rice restored in this way with rice that has been cooked normally, there is almost no difference in taste or texture.

Furthermore, the instant rice obtained by the method of the present invention does not deteriorate in quality due to oxidation or the like even if stored for a long period of time.

In addition, it is possible to prevent defective products such as sticky rice and broken rice during production and achieve high yields.

Experimental examples and examples are listed below.

Note that all percentages in the present invention represent weight percentages.

Experimental example 1 Regarding the influence of each gelatinization method on product quality 1. Test method 1 kg of polished rice was washed with water, soaked in water at 20°C overnight, and gelatinized under various conditions until its water content was 15%. Each instant rice sample was prepared by drying with hot air at 80° C. until the temperature reached 200° C., and then expanding it by contacting it with hot air at 200° C. for 20 seconds.

250ml of hot water was added to each of the obtained 100S' samples, held for 15 seconds, the hot water was removed, and the samples were left for 5 minutes in a sealed state. I did it.

In this case, a score of less than 7 points indicates that the core is stiff and the taste is poor.

In addition, 100ml of boiling water was added to each instant rice sample 152 and kept for 30 seconds, then the hot water was removed and the rice was sealed for 5 minutes.
After standing for a minute, the hardness of each sample was measured using a texturometer.

The measurement conditions of the texturometer are as follows.

Plunger: Diameter 20mm Platform: Flat plate Voltage: IV Clearance: 2mm Bite speed: Low speed (12 bites/min) Differences between each gelatinization method (1) Normal pressure one-degree steaming method (control method) Polished rice ( 1kg) - Soak overnight (20°C) - Drain - Add 1 g of sucrose fatty acid ester [Daiichi Kogyo Seiyaku DK Ester] and mix the powder uniformly - Steam at normal pressure (60 minutes) (2) Pressure 1 Degree steaming method (control method) Polished rice (1 kg) - Soaked overnight (20°C) - Drained Monosucrose fatty acid ester [Daiichi Kogyo Seiyaku ■DK Ester] If
Add and mix the powder uniformly - Pressure steaming (1.5kg 10A
, 20 minutes) (3) Normal pressure double steaming method (control method) Polished rice (1 kg) - overnight soaking (20°C) - draining - normal pressure steaming (15 minutes) - re-soaking [Lard 19.52, Sugar fatty acid ester [Daiichi Kogyo Seiyaku ■DK ester, 16.5
The heated rice is immersed in 1.3 J (50° C.) of an emulsion containing P for 5 minutes.

In this case, about 500 ml of water is absorbed by the rice] - Re-normal pressure steaming (60 minutes) (4) Double steaming method of normal pressure and pressurization (control method) Polished rice (1
kg) - Soaked overnight (20℃) - Drained - Steamed at normal pressure (15
minutes) - Re-soaking [conditions are the same as (3)] - Pressure steaming (0,
3kg/crA, 30 minutes) (5) Steaming-rolling-steaming method (method of the present invention) Polished rice (1kg) - overnight soaking (20℃
) - Drainer - Sucrose fatty acid ester [Daiichi Kogyo Seiyaku ■D
Add K ester] 1y and mix the powder uniformly - pressure steaming (
0.3 kg/cvl, 15 minutes) - Cooling (cooled to room temperature by applying cold air at 20°C for 5 minutes) - Rolling (rolls with a roll gap of 0.8 mm) Added water [Lard 2,51, sucrose fatty acid ester] [Daiichi Kogyo Seiyaku DK Ester) 0.5
Add 200 mA' of emulsion containing P, mix, and completely absorb water] - Re-pressurized steaming (0.3 kg/lA, 30 minutes) 2. Test results The test results are shown in the following table, α It was clearly recognized that the gelatinization method of the present invention, in which rolling treatment is performed during the gelatinization step, is superior.

Experimental Example 2 Regarding the influence of water content during drying before swelling treatment 1. Test method 1 kg of polished rice was washed with water, soaked in water overnight (20°C), drained, and then treated with sucrose fatty acid varnish 7-L [ Add Daiichi Kogyo Seiyaku ■DK Ester) IP and mix the powder uniformly.
It was steamed for 15 minutes with 0.6 kg/crtH steam.

This steamed rice is exposed to cold air at 30℃ for 5 minutes※※ to cool to room temperature, and then passed through rolls with a roll gap of 0.3mm, followed by 2 grams of lard and sucrose fatty acid ester [Daiichi Kogyo Seiyaku ■DK Ester] After adding 250 m of emulsion containing 0.52 and mixing to completely absorb water, 0.6 kg/
It was steamed for 20 minutes with ca steam.

Next, the rice was dried with hot air at 80° C. to each moisture content shown in the table below, and then exposed to high-temperature hot air at each temperature for 10 to 40 seconds (the optimum swelling time for each dried rice moisture content and hot air temperature was selected and applied).

) to prepare each instant rice sample.

A sensory test was conducted using the method described in Experiment 1, and the degree of expansion after swelling was also examined.

2. Test results The results of the test are shown in the following table, and it was clearly recognized that the moisture content conditions during drying in the present invention were excellent.

In other words, it was found that the food to which the processing conditions of the present invention were applied had excellent taste upon reconstitution and after restoration.

Experimental Example 3 Regarding the influence of hot air temperature during expansion 1. Test method After washing 1 kg of polished rice, soak it in water overnight (25°C), drain it, and then apply sucrose fatty acid ester [Daiichi Kogyo Seiyaku DK]
Add ester) IP, mix the powder uniformly, and mix at normal pressure for 30 minutes.
After steaming for a minute, the product was cooled by exposing it to cold air at 20° C. for 5 minutes, and then rolled through rolls with a roll gap of 0.2.

This rice grain contains sucrose fatty acid ester [Daiichi Kogyo Seiyaku DK]
Add a solution 400a containing 2-5P (ester), mix to completely absorb water, then steam again at normal pressure for 30 minutes to perform a sufficient and advanced gelatinization treatment, and then heat the mixture with hot air at 80°C to reduce the water content to 15%. After drying until dry, hot air at the temperatures shown in the following table was applied for 10 to 40 seconds (optimum swelling time ★★ at each temperature was selected).

) to prepare each instant rice sample.

Then, a sensory test was conducted using the method described in Experimental Example 1.
The degree of expansion after swelling was also tested.

In the sensory test, a score of less than 7 indicates that the texture is insufficient and the core is chewy or has a burnt odor, resulting in poor taste.

2. Test results The test results are shown in the following table, and it was clearly recognized that the temperature conditions during swelling in the method of the present invention were excellent.

Example 1 1 kg of domestic polished rice (new rice) was washed with 60°C hot water 21
The powder was soaked for about 1 hour (water content approx. 30%), drained, and then 0.5P of glycerin fatty acid ester (Narita Pharmaceutical ■, Emulgy MS) was added to the powder, mixed uniformly, and then steamed at room temperature for 30 minutes (water content approx. 33%). %).

This steamed rice was cooled to room temperature by blowing cold air at 10°C for about 5 minutes, then rolled through rolls with a roll gap of 0.3 mm, and then mixed with sucrose fatty acid ester [Daiichi Kogyo Seiyaku ■, DK Ester] 1y. Add 100ml of aqueous solution, mix, and completely absorb the water, then 0.4kg/crA
Steam for 15 minutes with steam to achieve a high degree of gelatinization (approximately 38% moisture), then dry with hot air at 60°C until the moisture content is 20%, and then expose to high-temperature hot air at approximately 180°C for 40 seconds to expand. The expanded rice was cooled to about room temperature by blowing cold air at about 40° C. to prepare instant rice according to the method of the present invention.

The obtained instant rice has no change in quality even if it is stored at room temperature for one year after being sealed, and when reconstituted, it is delicious and has excellent texture.

In addition, add 250ml of boiling water to 1 ooff of the obtained instant rice, leave it for about 10 seconds, remove the hot water, and boil it in a sealed state for 5 minutes to easily restore it to cooked rice.
Moreover, the taste and texture of the rice is almost the same as that of normally cooked rice.

In addition, delicious boiled rice, pilaf, etc. can be obtained by adding appropriate ingredients (dried products) to instant rice in advance and seasoning it when reconstituted.

Example 2 After washing 1 kg of domestically produced polished rice (old rice) with water, citric acid 500
rv, sodium citrate 500η, polymerized phosphate [Narita Pharmaceutical ■, Polyrinsan "Takeda" 2-B,: 14
After soaking in aqueous solution 21 containing P at a water temperature of about 20°C for 15 hours (water content about 31%) and draining, sucrose fatty acid ester [Daiichi Kogyo Seiyaku ■, DK Ester, :] 0.5 P
After adding and uniformly mixing the powder, it was steamed for 20 minutes with 0.3 kg/lyA steam.

(About 34% moisture) This steamed rice was exposed to cold air at 20°C for 5 minutes to cool it to room temperature, and then the rice was heated with a roll gap of 0.6 t.
Rolled through a roll of 100 nm, and then rolled with glycerin fatty acid ester [Narita Pharmaceutical ■, Emulgy Y-61] 0
．． 1f, add 400Ttl of emulsion containing 3t of lard,
After mixing and completely absorbing water, 0.8 kg/lsl
The rice is steamed for 30 minutes to highly gelatinize the rice to its core (with a moisture content of approximately 49%), then dried with hot air at 80°C until the moisture content is 8%, and then exposed to high-temperature hot air at approximately 250°C for 10 seconds. The rice was then expanded, and the expanded rice was cooled to about room temperature by blowing cold air at about 30° C. to prepare instant rice according to the method of the present invention.

The obtained instant rice does not change in quality even if it is stored at room temperature for one year after being sealed, and when reconstituted, it has excellent taste and texture.

Note that when the instant rice obtained is reconstituted by the method described in Example 1, it is possible to obtain rice of delicious quality that is almost the same as that of normally cooked high-quality cooked rice.

Moreover, by adding appropriate ingredients (dried products) to the instant rice in advance and seasoning it when reconstituted, delicious boiled rice and pilaf can be easily obtained.

Example 3 After washing 1 kg of polished rice with water, it was immersed in an aqueous solution 21 containing protease (Kaken Kagaku ■, Pronase) 11n9 at a water temperature of about 10°C for about 15 hours (water content about 29%), and then drained and treated with sucrose fatty acid ester. [Daiichi Kogyo Seiyaku ■, DK ester, IO, 5P were added and the powder was mixed uniformly,
It was steamed for 10 minutes with 0.8 kg/crA steam (water content approximately 32%).

After cooling the steamed rice to room temperature by blowing air at 40°C for about 5 minutes, the roll gap was 0. ], rolled through a mm roll, and then an aqueous solution 3 containing glycerin fatty acid ester [Narita Pharmaceutical ■, Emulgy MS] 2P.
After adding 00ml of rice and mixing to completely absorb water, the rice was steamed for 20 minutes at normal pressure to completely gelatinize the rice to the core (approximately 45% moisture).

This steamed rice is dried with hot air at 100°C until the moisture content is 14%, then brought into contact with high-temperature hot air at about 210°C for 20 seconds to swell it, and the swollen rice is cooled to about room temperature by blowing cold air at about 20°C. , instant rice was prepared by the method of the present invention.

The obtained instant rice remains a product even if stored at room temperature for one year after being sealed.
There is no change in quality, and when reconstituted, it is delicious and has an excellent texture.

Add 300ml of boiling water to the obtained 70'iI' of instant rice, add powdered soup, seaweed, and gravy as appropriate and mix, seal and hold for about 5 minutes to obtain Ochazuke with a texture similar to cooked rice. .

Claims (1)

[Scope of Claims] 1. A method for producing instant rice, which comprises steaming rice until it is raw, rolling it, adding water, steaming it again to fully gelatinize it, and further drying it and then swelling it. 2. The method for producing instant rice according to claim 1, wherein rice is gelatinized in the presence of a surfactant and/or oil or fat.