JP2000060458A - Production of cooked rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a cooked rice capable of being preserved for long term, and excellent in texture, flavor and appearance. SOLUTION: This method for producing a cooked rice comprising a step for washing the rice, a step for dipping the rice, a step for cooking the rice, and a step for carrying out an aseptic packaging is carried out by washing the raw material rice with an organic acid or organic acid salt-containing aqueous solution, and immersing the washed rice in a hypochlorous acid-containing water having pH 4.1-6.5 and 50-80 ppm concentration of the hypochlorous acid.

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 cooked rice, and more particularly to a method for producing cooked rice which can be stored for a long period of time and is excellent in appearance, flavor and texture by washing and soaking in a specific aqueous solution.

[0002]

2. Description of the Related Art Due to recent changes in social life, cooked rice foods that can be eaten with a simple treatment and that can be stored for a long time have been developed. These are generally heat-treated (about 100 ° C.) when cooking rice. Separately, high temperatures such as retort treatment (12
The heat treatment of about 0 ° C) is performed, and the texture of cooked rice,
The flavor is significantly impaired. For this reason, studies have been made on a method for producing cooked rice that enables long-term storage without impairing the texture and flavor.

For example, a method for cooking aseptic cooked rice is characterized in that after washing the rice, it is immersed in super acidic water having a pH of 3 or less, and then neutralized with alkaline ionized water to cook the rice (JP-A-8-17).
No. 3066), a method for producing cooked rice foods characterized by adding a pH adjusting agent after water is absorbed in raw rice before cooking (Japanese Patent Laid-Open No. 7-170921), and at least used in the cooking step. PH of cooking water at room temperature is 4.
0 or less, oxidation-reduction potential of 820 mV or more, dissolved chlorine concentration of 1 to 200 ppm, dissolved oxygen concentration of 50 ppm or less sterilized water is used to cook rice (JP-A-8-
No. 131136), etc. are known.

[0004]

However, since the technique disclosed in Japanese Patent Laid-Open No. 8-173066 is soaked in super acidic water and neutralized with alkaline ionized water, a sufficient bactericidal effect is not always obtained and the super acidic water is not obtained. When the soaking time is prolonged, there is a problem that the sourness remains in the cooked rice and the flavor deteriorates. Further, in the technique disclosed in Japanese Patent Laid-Open No. 7-170921, the taste of the organic acid remains because it is immersed in the organic acid-containing water for 1 to 2 hours, and sufficient bactericidal effect cannot be obtained only by immersing it in the organic acid-containing water. . Further, the technique disclosed in Japanese Patent Application Laid-Open No. 8-131136 has a problem that sterilized water having a low pH is used as the cooking water, so that the cooked rice remains sour and the flavor is deteriorated.

Therefore, it is an object of the present invention to provide a method for producing cooked rice which can be stored for a long period of time and is excellent in texture, flavor and appearance.

[0006]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above object, the present inventors have found that in a method for producing cooked rice consisting of a rice washing process, a dipping process, a rice cooking process and an aseptic packaging process, raw rice is treated with an organic acid. Or organic acid salt (hereinafter “organic acid, etc.”)
If it is washed with water containing water and then immersed in water containing hypochlorous acid having a pH of 4.1 to 6.5, it has excellent heat resistance due to the excellent bactericidal action of water containing organic acids and water containing hypochlorous acid. It can be stored for a long period of time because it can completely kill the spore bacterium, and since it is immersed in immersion water having a relatively high pH, it is possible to obtain cooked rice excellent in flavor, texture and appearance, The present invention has been completed.

That is, the present invention provides a rice washing process, a dipping process,
In a method for producing cooked rice consisting of a rice cooking process and an aseptic packaging process, raw rice is washed with water containing organic acids, and then pH
It is intended to provide a method for producing cooked rice, which comprises immersing in the hypochlorous acid-containing water of 4.1 to 6.5.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the raw rice may be either sticky rice, sticky rice or a mixture thereof. Examples of the organic acid include monovalent organic acids such as acetic acid, lactic acid and gluconic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,
Examples thereof include divalent organic acids such as adipic acid and malic acid, and trivalent organic acids such as citric acid. Examples of salts of organic acids include sodium salts, potassium salts, calcium salts, magnesium salts and the like. Of these, gluconic acid, adipic acid, and lactic acid, which exhibit less sourness, are particularly preferable. In effectively sterilizing the raw rice without impairing the flavor of cooked rice, the content of organic acid or the like in the organic acid-containing water is 0.01 to 1% by weight, particularly 0.02 to 0.7% by weight. Preferably.

For washing rice, for example, 10 to 400 parts by weight, preferably 1 part by weight of water containing an organic acid, etc., relative to 100 parts by weight of raw rice.
It can be carried out by adding 0 to 300 parts by weight and stirring manually or with a screw type rice washer or the like. After stirring, the water containing the organic acid or the like may be discarded and the same operation may be repeated a plurality of times. The stirring time is not particularly limited, but is preferably 1 minute or longer, particularly preferably 2 minutes or longer.

After washing the rice, the water containing organic acids and the like is discarded and immersed in water containing hypochlorous acid. The pH of the water containing hypochlorous acid is 4.1 to 6.5, preferably 5 to 5.5. When the pH is 4.1 to 6.5, an excellent bactericidal effect is exhibited and the flavor of cooked rice is not deteriorated.
Effective chlorine concentration in water containing hypochlorous acid is 50-80ppm
Is preferred. The redox potential of water containing hypochlorous acid is 8
00-1000 mV is preferable. When the effective chlorine concentration and the redox potential are in the above ranges, the bactericidal effect is particularly remarkable.
As the hypochlorous acid-containing water, for example, soft oxidizing water manufactured by OMCO can be used.

The amount of hypochlorous acid-containing water used is 100 to 400 parts by weight, particularly 200 to 300 parts by weight, based on 100 parts by weight of rice.
Parts by weight are preferred. Further, the immersion time is preferably 15 minutes or longer, particularly preferably 30 minutes or longer. When the amount used and the immersion time are within the above ranges, it is possible to obtain a cooked rice that exhibits an excellent bactericidal effect and has a good texture.

After the completion of the immersion, rice is cooked using, for example, a rice cooker or a continuous atmospheric steaming device. In order to produce a cooked rice food that can be stored for a long period of time, it is preferable to use a continuous atmospheric steaming device. Since the hypochlorous acid-containing water has a relatively high pH and does not have sourness or unpleasant odor, it is possible to obtain cooked rice having excellent flavor even if the hypochlorous acid-containing water is cooked as it is. It is preferable to discard the hypochlorous acid-containing water and cook the cooked water by using, for example, ion-exchanged water or tap water. In the case of using a continuous atmospheric pressure cooking apparatus, for example, the rice and ion-exchanged water obtained above are filled in a heat-resistant container, and rice is cooked in the apparatus for about 15 to 60 minutes. The obtained cooked rice is completely sterilized, and by aseptically packaging it, cooked rice that can be stored for a long period of time can be obtained.

[0013]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

Examples 1 to 3 and Comparative Examples 1 to 5 Raw milled rice (Molecule rice with 90% yield and self-produced rice) 10
Water containing 0 parts by weight of each organic acid shown in Table 1 and Table 2
Rice was washed for 5 minutes with a screw type rice washer using a part by weight. After removing the water containing organic acid, each immersion water 30 shown in Table 1
0 part by weight was added and kept for 2 hours. Then heat resistant container 3
90 g of rice that had been soaked in dipping water and 110 g of ion-exchanged water were filled in 0 pieces each, and cooked and cooked for 30 minutes by a continuous atmospheric pressure steaming device. Next, the head space of each container was replaced with nitrogen gas in a sterile booth and sealed to obtain a cooked rice food.

[0015]

[Table 1]

[0016]

[Table 2]

Test Example 1 Each of the cooked rice foods obtained above was stored at 35 ° C. for 14 days, the number of putrefaction was measured, and the appearance, flavor and texture of the non-putry ones were evaluated according to the following evaluation criteria. did. The results are shown in Tables 1 and 2.

Evaluation criteria Appearance 5: The grain shape is uniform, the gloss and color are particularly good, and the surface is not rough at all. 4: Grain shape is uniform, gloss and color are good, and the surface is not rough. 3: Grain shape, gloss and color are generally good, and the surface is not so rough. 2: Grain is slightly broken, gloss and color are slightly inferior, and surface is slightly rough. 1: Grain is broken, gloss and color are inferior, and the surface is rough. Flavor 5: Aroma and sweetness peculiar to freshly cooked rice are particularly good,
There is no off taste such as sourness. 4: The scent and sweetness peculiar to freshly cooked cooked rice are good, and there is no off-taste such as acidity. 3: The aroma and sweetness peculiar to freshly cooked rice are generally good,
There is not much sourness. 2: Aroma peculiar to freshly cooked rice, slightly lacking in sweetness, and slightly off-taste. 1: There is a peculiar fragrance, lack of sweetness, and sourness peculiar to freshly cooked cooked rice. Texture 5: The stickiness and hardness peculiar to freshly cooked rice are particularly good. 4: Good stickiness and hardness peculiar to freshly cooked cooked rice. 3: The stickiness and hardness peculiar to freshly cooked cooked rice are generally good. 2: The stickiness and hardness peculiar to freshly cooked rice are slightly lacking. 1: Lack of stickiness and hardness peculiar to freshly cooked rice.

In Examples 1 to 3, spoilage did not occur at all, and the appearance, flavor and texture were very excellent. On the other hand, in Comparative Examples 1, 2 and 4, many rot. Comparative Examples 3 and 5
Was not spoiled, but the appearance, flavor and texture of Examples 1 to 1
It was inferior to 3. That is, it was confirmed that by using water containing an organic acid or the like for washing rice and using water containing a specific hypochlorous acid as immersion water, cooked rice that can be stored for a long period of time and has excellent appearance, flavor, etc. can be produced.

[0020]

EFFECTS OF THE INVENTION By the method of the present invention, heat-resistant spore-forming bacterium can be completely killed, so that long-term storage is possible, and cooked rice excellent in appearance, flavor and texture can be obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Shirai             5-3-1 Tsurugaoka, Oi-cho, Iruma-gun, Saitama Prefecture               Nisshin Seifun Co., Ltd. Food Research Institute (72) Inventor Takashi Masuda             1-25-25 Kandanishikicho, Chiyoda-ku, Tokyo Nisshin             Milling Co., Ltd. F-term (reference) 4B023 LC05 LE11 LK01 LK04 LP04                       LP05 LQ03

Claims (3)

[Claims] 1. A method for producing cooked rice comprising a rice washing step, a soaking step, a rice cooking step and an aseptic packaging step, in which raw rice is washed with an organic acid or organic acid salt-containing aqueous solution, and then pH is adjusted.
A method for producing cooked rice, which comprises immersing in the hypochlorous acid-containing water of 4.1 to 6.5. 2. The method for producing cooked rice according to claim 1, wherein the hypochlorous acid concentration in the hypochlorous acid-containing water is 50 to 80 ppm. 3. The redox potential of water containing hypochlorous acid is 80.
The method for producing cooked rice according to claim 1 or 2, which is 0 to 1000 mV.