JP2001299246A - Method for producing pregelatinized unpolished rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing pregelatinized unpolished rice, in which the pregelatinized unpolished rice keeping the nutritive ingredients of unpolishd rice and having an excellent taste and excellent digestive absorbability even by the usual cooking method for polished rice is efficiently produced. SOLUTION: This method for producing the pregelatinized unpolished rice, characterized by comprising a water-absorbing process for allowing unpolished rice to absorb water, a drainage process for removing water adhered to the surface of the water-absorbed unpolished rice, a steaming process for directly bringing the drained unpolished rice into contact with high temperature steam, a high frequency wave heating process for irradiating the steamed unpolished rice with microwaves, and a drying process for drying the high frequency wave- heated unpolished rice. In the steaming process, the absorptive supply of the water to the unpolished rice and the rough pregelatinization of raw starch are carried out. In the high frequency wave heating process, the thermal denaturation of proteins, the perfect gelatinization of the starch, the scattering of fatty acids mainly causing the bad smell, and the evaporation of excessive water are performed. Consequently, the pregelatinized unpolished rice can be boiled by the same boiling method as that for polished rice to give the boiled unpolished rice having excellent taste and excellent absorbability without deteriorating the nutritive ingredients of the unpolished rice. Further, since the excessive water evaporates in the high frequency wave heating process, the drying time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for pregelatinizing brown rice, and more particularly, to a method for preserving many nutrients of brown rice without requiring special cooking utensils and cooking methods. The present invention relates to a method for producing processed rice that can be cooked in a normal rice cooker or a rice cooker, is soft and digestible, and can be eaten as delicious as white rice.

[0002]

2. Description of the Related Art In recent years, the diet has changed drastically, but the staple food of the Japanese is still rice, and the ratio of rice protein to the protein intake in Japan is 18%.
This is supported by the fact that it is expensive. And
The rice we usually eat is white rice obtained by milling brown rice to remove bran, that is, polished rice. Although this milled rice has good taste and digestion, milling removes many nutrients of brown rice, such as various vitamins, minerals, and dietary fiber. As a result, it has long been known that brown rice is far superior in terms of nutritional balance in terms of nutritional balance, because carbohydrates, proteins, and water, excluding fiber, are the main components. Have been.

[0003] However, except for those who are in special circumstances that require some dietary treatments, brown rice has a poor water absorbency and can be cooked softly with rice cooked like white rice, even if it is known to be healthy. Unfortunately, the spread of brown rice is unfortunately low due to the poor digestibility and the smell peculiar to bran when eaten, and the texture is not as good as white rice.

[0004] As a conventional technique for solving the above problems of brown rice, for example, in order to cook brown rice relatively softly, the cooking temperature is slightly increased by using a pressure cooker (about 110).
℃), it is known that cooked food is softened and α-formation is promoted. Recently, as one example of a method for producing pre-gelatinized brown rice, a technique of irradiating soaked brown rice with microwaves in an airtight heating container to pregelatinize the brown rice and then vacuum-drying the same has been disclosed (patented). No. 2632612).

[0005]

However, the method of raising the cooking temperature by increasing the vapor pressure of water using a pressure cooker requires a pressure cooker, which is less familiar to other general cooking methods, and white rice. There is also an annoying problem such as the need to change the cooking conditions when mixing rice with brown rice.

[0006] Further, in the method for producing pregelatinized brown rice, which is preliminarily pregelatinized by heat treatment using only a microwave and then vacuum dried, brown rice itself has a poor water absorption rate, so that microwave absorbency is reduced (loss of microwave). The larger the value of the coefficient tan δ · ε _r, the better the microwave absorption and the easier it is to heat uniformly.
nδ: dielectric loss angle of the object to be heated, ε _r : equivalent dielectric constant. ), Heat exchange inside brown rice due to irradiation is poor. As a result, for example, gelatinization and swelling of the protein are caused, and the heat treatment and the effect of the gelatinization of the starch are incomplete.

The problem to be solved by the present invention is that brown rice is heat-treated uniformly and sufficiently so that, for example, the gelatinization of starch, the thermal denaturation of proteins, and the generation of fatty acids, which are the main cause of odor, are caused. Completely splash and keep the nutrients of brown rice even in the same way of cooking as normal white rice,
Moreover, it is to efficiently produce gelatinized brown rice having excellent taste and digestive absorption.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a water absorption step of absorbing brown rice, a water removal step of removing water adhering to the surface of the brown rice grains, and a steaming step of bringing high-temperature steam into direct contact with the brown rice after the water removal step. And a high-frequency heating step of uniformly irradiating the rice grains from the inside by irradiating microwaves to the brown rice after the steaming step, and a drying step of drying the brown rice after the high-frequency heating step.

In the water absorption step, brown rice is immersed in water until the water absorption reaches a saturated state. The primary heating steaming step, which is performed after the draining step, aims at capturing water absorption of brown rice and coarsely pregelatinizing raw starch. In addition, the high-frequency heating step of the secondary heating involves thermal denaturation of proteins such as albumin, globulin, and prolamin, which are present in the outer layer of brown rice and have a good amino acid composition in the inner layer, and complete gelatinization of starches. Done. Further, in this high-frequency heating step, fatty acids, which are the main cause of the smell that deteriorates the taste when cooked, are scattered, and unnecessary excess moisture is evaporated. The steamed brown rice that has passed through the high-frequency heating step is dried in a drying step within a moisture content range of 11 to 15% to be a product, that is, pregelatinized brown rice.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION First, the raw material is brown rice such as glutinous rice or glutinous rice. However, it is also possible to use semi-milled rice as a raw material, which leaves the nutritional components of brown rice.

[0011] For the purpose of absorbing water into the rice grains, the rice is easily washed with water, and then brown rice is immersed in a water tank filled with water at 10 to 30 ° C or a special immersion tank to perform an immersion treatment.
In addition, unlike polished rice, brown rice is wrapped in the skin, seed coat, and even the aleurone layer, so it has poor water absorption, and although there is a difference in the water absorption time depending on the temperature of the immersion water, general brown rice is Under immersion conditions, the water content is 25-28%, at most 30
% Can be said to be the saturation limit.

After the immersion, water is removed from the water and left for a short time, or if necessary, for example, using a centrifugal dehydrator or the like, to remove water adhering to the surface of the immersed brown rice, ie, water adhering to the surface. Perform

Next, 100 to 1 pieces of brown rice are soaked and drained.
A so-called steaming treatment is performed in which live steam at 04 ° C. is brought into direct contact for about 25 to 30 minutes. As described above, this step is a preliminary pre-step for the next high-frequency heating, and aims at supplementing water absorption and roughening α. In addition, the moisture content of the brown rice becomes 35% or more by the steaming treatment, and the moisture reaches the central part of the rice grains sufficiently.

The steamed brown rice which has been subjected to the steaming process and has been subjected to the primary heating is spread to a thickness of about 5 to 10 cm, and then subjected to a high frequency heating treatment as a secondary heating. The frequency of the microwave to be irradiated is 2450 MHz, and the irradiation time is constant even if the irradiation power is constant, but the permeability of the electromagnetic wave that can be uniformly heated varies depending on the thickness and moisture content of steamed rice as the object to be heated, so there is some difference. Although it occurs, a range of about 5 to 10 minutes is appropriate. In this high frequency heating by microwaves, brown rice (dielectric) is uniformly heated from the inside (heated by internal friction generated by a high-frequency electric field of polarization phenomenon), so that brown rice is not sufficiently gelatinized. The starch in the central part, which has poor water absorption, is also pregelatinized to almost complete, thereby improving the pregelatinization rate of the whole brown rice.

[0015] The improvement in the thermal denaturation of the protein together with the increase in the pregelatinization rate improves the softness, the gelatinization and the swelling as well as the taste, the texture is greatly improved, and the digestion and absorption are also excellent. In addition, high-frequency heating has an effect of preliminary drying for evaporating excess water, in addition to the effect of scattering fatty acids, which are the main cause of the smell, and the thermal denaturation of proteins containing a substance (allergen) causing cereal allergy.

The brown rice heat-treated in this manner is supplied with dehumidified air at a temperature of 30 ° C. or less, and has a moisture content of 11 to 15%.
%, And the product as pregelatinized brown rice is completed. In addition, the drying method does not have any problem with hot air drying or vacuum drying, and is appropriately selected depending on the production scale. Further, the series of manufacturing steps of the present invention may be not only continuous processing using a conveyor or the like but also batch processing for each step. Furthermore, the method for producing pregelatinized brown rice according to the present invention can be sufficiently applied to not only brown rice but also koji rice used for brewing sake and miso, and it is possible to produce high-quality steamed rice. .

Finally, the case where the pre-gelatinized brown rice of the present invention is mixed with an equal amount of white rice and cooked will be described. After 1.5g of pregelatinized brown rice and 1.5g of washed white rice are absorbed for about 1 hour with slightly more water than 3g of white rice, cook for about 25-30 minutes, steam for about 5 minutes It ’s done,
It is almost the same as the case of ordinary white rice cooking. Of course, the rice cooked with only the pre-gelatinized brown rice of the present invention can be made longer in the water absorption time and the rice cook time than in the rice cooked with white rice. In addition,
This pre-gelatinized brown rice can be used for porridge and other cooking.

[0018]

According to the present invention, brown rice, which has a lower water absorption than polished rice, is subjected to high-frequency heating after steaming, which is the primary heating, so that starch is completely gelatinized and proteins are thermally denatured.
Disperses fatty acids, tastes good and has excellent digestive absorption α
The processed brown rice is obtained. In addition, since the high-frequency heating as the secondary heat treatment is performed as a pre-treatment before the drying treatment, the drying time can be shortened by the evaporating action of excess water due to the internal heating, so that the manufacturing cost can be reduced. Furthermore, since the pre-gelatinized brown rice does not need to be washed in advance, cooking can be performed easily.

Claims (1)

[Claims] 1. A water absorbing step of absorbing brown rice, a draining step of removing water adhering to the surface of the absorbed brown rice grains, a steaming step of directly contacting high-temperature steam with the brown rice that has undergone the draining step; A method for producing pregelatinized brown rice, comprising: a high-frequency heating step of uniformly heating rice grains from the inside by irradiating microwaves; and a drying step of drying brown rice that has passed through the high-frequency heating step.