JPS6016556A - Preparation of processed rice by gelatinizing only surface layer of rice grain - Google Patents

Abstract

PURPOSE:To provide processed rice gelatinized only the surface layer while keeping the core part of the rice grain from gelatinization, by drying the treated rice obtained by immersing the rice in water and steaming for a specific period or immersing the rice in hot water for a specific period. CONSTITUTION:Polished rice is washed with water, immersed in water for 5- 15min, drained, and steamed for >=6min, or polished rice is immersed in hot water for 5-8min. The treated rice is dried with hot air to obtain the objective processed rice.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing processed rice in which only the surface layer of rice grains is gelatinized without gelatinizing the inner layer.

Alpha rice, which has traditionally been famous as a processed rice, has many advantages, but its disadvantage is that it has poor taste when cooked. Therefore, it has been desired to develop a processed rice that retains the advantages of alpha rice and has a taste equal to the natural flavor of the rice itself.

The present invention satisfies this expectation. In other words, we found that the flaw in the taste of Alpha rice was due to the fact that the inner layer of the rice grain was gelatinized, and we investigated a method of gelatinizing only the surface layer of the rice grain without gelatinizing the inner layer. , the present invention has been achieved.

The structural feature of the present invention is that rice is soaked in water for 5 to 15 minutes,
Then, by drying the rice that has been steamed for at least 6 minutes or soaked in boiling water for 5 to 8 minutes, only the surface layer of the rice grain can be gelatinized without gelatinizing the inner layer of the rice grain.

The present invention will be explained in detail below.

In general, rice has a moisture content of 14% to 16%, so no matter how much steaming and heating it does, it will not gelatinize, and it will become hard and crumbly into fine powder. With M, the water content of the rice grains increases, and when heated, gelatinization occurs from the surface layer of the rice grains, and gelatinization occurs to the inside over time, and when rice is soaked in boiling water, the same gelatinization as described above occurs. We obtained the knowledge that this process was carried out.

When rice is soaked in water, there are some differences in the water absorption rate depending on the temperature of the water, but when rice is first soaked, it absorbs at a high rate, and after about 2 hours it stops at 20% to 22%, with no change observed. I can't. That is, by adjusting the soaking time, it is possible to absorb water only in the surface layer of the rice grains, and therefore, it is also possible to gelatinize only the surface layer of the rice grains by heating.

Looking at the relationship between soaking time and moisture absorption rate, it is 5 minutes---
1. Approximately 5% for 10 minutes-- Approximately 9% for 15 minutes--
It was found that ... - about 11% of moisture was absorbed, and for 30 minutes - about 15%, respectively.

Note that for rice grains with an absorption rate of 5% or less, rice grains that have been gelatinized by steaming and then dried will be completely crumbly and have extremely poor taste even if the heating time during cooking is prolonged.

Next, Table 1 shows the results of examining the taste of cooked rice obtained by cooking processed rice in which the surface layer of the rice grains was gelatinized by changing the soaking time of the rice in water and the steaming time after soaking.

Table 1 Judging from the results shown in Table 1, in order to obtain cooked rice with good taste, the soaking time must be at least 5 minutes, and the steaming time must also be 6 minutes.
It turns out that a time of at least 1 minute is preferable.

Therefore, in order to produce dry rice in which only the surface layer of rice grains is gelatinized, it is necessary to soak the rice in water for at least 5 minutes and to steam it for at least 6 minutes after soaking. If the soaking time and the subsequent steaming time are increased, the inside of the rice grains will be gelatinized, so the soaking time should be 5 to 15 minutes, and the steaming time should be 6 minutes.
It is appropriate to set the time within a range of 15 minutes to 15 minutes.

In addition, the rice grains soaked and steamed as described above swell and become highly absorbent, so after soaking and adhering a solution containing starch-degrading enzymes for rice cooking, seasonings, nutrients, fragrances, etc. It can also be dried.Drying is preferably carried out to a moisture content of 5 to 15%, but from the viewpoint of storage it is preferable to reduce the moisture content to 10% or less.

Further, in order to gelatinize only the surface layer of the rice grains by soaking them in hot water, it is usually necessary to soak the rice in hot water of 90° C. or higher for 5 to 8 minutes. The regulation of this immersion time is based on the test results shown in Table 2 below.

Table 2 As is clear from Table 2, 5 minutes of immersion is required to gelatinize the surface layer of rice grains by immersion in boiling water, while gelatinization progresses to the inside of the rice grains after 8 minutes of immersion. becomes unfit for purpose. In this way, the rice grains are soaked in boiling water to gelatinize only the surface layer, and then soaked with solutions of enzymes, seasonings, nutrients, etc. as necessary, and then dried to have a moisture content of 5 to 50%.
Obtain 15% processed rice.

The processed rice according to the present invention obtained as described above has less water content than conventional alpha rice, so the drying time is 1/1/1.
It can be completed in 4 hours and has a long shelf life. In addition, when cooking this processed rice, not only is the heating time shortened, but operations such as washing and soaking the rice in water are omitted;
As mentioned above, there is an advantage that the taste can be easily improved by adding enzymes, seasonings, nutrients, etc. For example, for food for sick people, a powder-digesting enzyme is added to increase its digestibility, for pregnant women food, calcium is added to fortify it, and for commercial food (
Seasonings can be added to sushi rice, etc.). Therefore, the processed rice according to the present invention has a much wider range of uses than conventional alpha rice.

Examples are shown below.

Example 1 30 kg of polished rice was washed and immersed in water for 6 minutes, then drained and boiled at a temperature of 100° C. for 8 minutes. The surface layer of the rice grain of the obtained steamed rice was gelatinized, but the inner layer was in a state of uncooked rice. The steamed rice was then dried with hot air at 80° C. or higher for about 45 minutes to obtain processed rice with a moisture content of 10%. The yield of processed rice is 86%.

When the processed rice obtained as described above was cooked for 15 minutes without being soaked in water, cooked rice having the same texture and taste as the cooked rice for a connoisseur was obtained.

The steamed rice mentioned above, in which only the surface layer of the rice grain is gelatinized, is about 10
% of moisture, so add an aqueous solution containing calcium to 1 kg of the steamed rice to absorb approximately 100 c of the aqueous solution.
Processed rice to which calcium has been added can be easily prepared by absorbing c, and flavored processed rice can also be prepared by adding a seasoning liquid (e.g., salt water or vinegar) instead of the above aqueous solution. be able to.

Example 2 30 kg of polished rice was washed with boiling water at 95 to 100°C, immersed in the boiling water for 6 minutes, and then taken out and drained.

The surface layer of the rice grains of the obtained soaked rice was gelatinized, but the inner layer was in a state of uncooked rice. Next, this soaked rice was heated to 80°C.
The rice was dried with the above hot air for about 45 minutes to obtain processed rice with a moisture content of 10%. The yield of processed rice is 86%.

When the obtained processed rice was cooked as it was, it became cooked rice with good texture and taste.

Further, this processed rice can be flavored or added with calcium in the same manner as described in Example 1.

Applicant Hyozo Konno Agent Miya 1) Yutaka Hiro

Claims (1)

[Claims] Gelatinization of only the surface layer of rice grains, characterized by soaking rice in water for 5 to 15 minutes and then steaming for at least 6 minutes, or soaking rice in boiling water for 5 to 8 minutes and then drying it. A method for producing processed rice.