JPH0438385B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing instant dried rice that has hot water restoration properties, that is, quick hot water restoration, and has a taste after restoration that is close to the texture of commonly eaten cooked rice. Generally, instant dry rice is produced by soaking polished rice in water, followed by cooking and drying (for example,
JP-A No. 56-23857, JP-A-49-85258) and cases where immersion in water is followed by steaming and drying (e.g., JP-A-52-102453, JP-A-52-31944). I can do things. From the viewpoint of production cost and process simplicity, it is clearly preferable to use the steaming method to alpha-alize rice, and since it is also possible to produce rice continuously, the steaming method is currently used to produce instant dried rice on an industrial scale. . However, when steaming rice soaked in water to turn it into alpha, the water content of the steamed rice is 40% or less after 40 minutes of steaming, and 120%
Even when steamed, it only absorbs less than 50% of water, which is much less than regular cooked rice (60-65%). Therefore, sufficient alpha conversion is not carried out during steaming, and when this steamed rice is used to make ordinary instant dry rice,
The texture of the dried rice after being rehydrated in hot water is very powdery, with a feeling that the rice grains are broken, resulting in rice that does not have much elasticity or viscosity. The inventors of the present invention have conducted various studies aimed at resolving the shortcomings of instant drying rice using conventional methods. As a result, they have found that, after washing and immersing polished rice in water, sufficient extra hot water is sprinkled on it during steaming. By passing the steamed rice through hot water, the moisture in the steamed rice at the end of steaming is removed.
Add water to 60% or more and add enzyme to rice.
By soaking the above-mentioned steamed rice in an aqueous solution containing 0.01 to 0.5% by weight and having a pH of 4 to 8, washing the soaked rice with water and drying, it is possible to produce instant dried rice with a preferable texture. This discovery led to the completion of the present invention. The present invention will be explained in detail below. The rice used in the present invention is not particularly concerned with its origin, type, or quality; for example, domestic rice, foreign rice, soft rice, old rice, or old rice can be used. After washing these polished rice with water, they are pre-soaked in water. In this case, a seasoning liquid may be added. The amount of water or seasoning liquid may be 0.7 to 1.7 times the weight of rice, and usually 1.1 to 1.4 times. What is dissolved in this seasoning liquid is:
Seasonings such as salt, sugar, soybean oil, ajirin, vinegar, sake, surfactants and sugars other than sugar,
Alternatively, substances such as polyhydric alcohols such as propylene glycol are used. Next, it is steamed to form an alpha layer, and the process involves spreading it evenly on a net conveyor to a thickness of about 1 cm to 5 cm, and steaming it with saturated steam. There is a linear relationship between the steaming time and the moisture content of steamed rice, but if the moisture content of soaked rice is 30%, then
37% in minutes, 41% in 1 hour, 49% in 2 hours,
Even if it is steamed further, the moisture content cannot be increased by steaming, and the moisture content is very low compared to normal cooked rice. However, if you water the rice under the same conditions by sprinkling a large amount of warm water after 20 minutes and 30 minutes, the water absorption rate will be 61% after 40 minutes of steaming, which is the same level as cooked rice. A more preferable product can be obtained by immersing this hydrated steamed rice in an enzyme aqueous solution containing pectinase, cellulase, or protease.
The amount of enzyme solution used for soaking is preferably such that the rice grains are kept separated, and the amount is 2 to 5 times the weight of the rice grains. It is preferable to perform gentle stirring to keep the rice grains separated, since this will reduce variations in the texture of the dried instant rice when it is reconstituted with hot water. The pH of the soaking liquid must be selected within the range of 4 to 8.
Adjust the pH in advance with acid or alkali to the optimum pH for the enzyme. If the pH is below 4, the taste of the instant rice after pouring and restoring will be bad, and if the pH is above 8, the rice will elute into the enzyme aqueous solution, affecting the yield, and the time for pouring and restoring will become longer. There's a problem. The temperature of the immersion liquid should be set at 20 to 60℃, which is such that there is no loss of activity of each enzyme, and the immersion time should be set to 1 to 60℃.
The time is appropriate. The amount of enzyme is based on the weight ratio of raw rice.
An appropriate amount of enzyme is 0.01% to 0.5%, preferably 0.03 to 0.3%. If the enzyme amount is less than 0.01%, the immersion time will be long, resulting in a decrease in yield. Also, if the enzyme amount is 0.5% or more, the soaking time will be shortened, but
The texture of instant rice after pouring and restoring is too soft,
Further, there are problems such as significant manufacturing costs. The gelatinized rice grains with high water content obtained in this way are washed with water appropriately, and after draining, the water content is 2-15%.
Dry by heat drying, hot air drying, vacuum drying, etc. until . In the instant dried rice of the present invention obtained by the method described above, the entire rice grain has a uniform porous structure, so that hot water can easily penetrate into the center of the rice grain. Therefore, the instant dried rice of the present invention can be easily restored by placing it in a container, adding boiling water, covering it with a lid, and allowing it to stand for several minutes. The rice obtained by the restoration has a stickiness and elasticity that is very similar in taste to the texture of normally eaten cooked rice, and it does not have the biggest drawback of conventional instant rice, which is the image of a hard core. It is something to dispel. Steamed rice using the conventional method is dried with a moisture content of less than 60%, so compared to cooked rice, the texture is more brittle and less sticky, whereas in the production method of the present invention, the moisture content is less than 60%.
Since the rice is steamed and dried while maintaining the rice at a temperature of at least %, the degree of gelatinization increases and the texture after reconstitution becomes similar to that of cooked rice. Example 1 After washing 1 kg of polished rice, it was pre-soaked in water at 30°C for 2 hours. After draining, the pre-soaked rice was divided into two parts, and one half was placed in a steamer lined with a cloth and steamed for 20 minutes (moisture content 36.1%). Then 1.5Kg of warm water (50℃)
and immersed for 5 minutes. Subsequently, the water was drained and steamed again for 20 minutes in a steamer covered with a cloth (moisture content 61.0%). (Sample A) As a comparative example, the other sample was placed in a steamer covered with a cloth and steamed for 40 minutes (moisture content 40.3%). (Sample B) Each steamed rice was heated with warm water (40℃, PH) containing 0.5g of pectinase (Novo Industries, Ultrazyme 100).
4) It was dispersed in 1.5 and left to stand for 2 hours and immersed.
After draining and washing with water, the rice was dried with hot air at 80°C for 4 hours to obtain instant rice A and B. 50 g of instant rice A and B were placed in a styrofoam container, 250 ml of boiling water was added, the container was covered, and 3 minutes later, the container was evaluated by a sensory test. The results are shown in Table-2. 【table】

Claims (1)

[Claims] 1 Rice is steamed while adding water so that the moisture content at the end of steaming is 60% or more to turn it into alpha, and one of pectinase, cellulase, or protease is added to the rice.
A method for producing instant dried rice, which comprises soaking the rice in an aqueous solution containing 0.01 to 0.5% by weight of enzymes of seeds or higher and having a pH of 4 to 8, washing the soaked rice with water, and drying the rice.