JPH0321141B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for treating grain husks by producing a large number of cracks, fissures, etc. in the husks of grains to make them easier to eat. Here, grains refer to edible grains such as rice, wheat, barley, pigeon oats, and corn. These grains can be roughly divided into three parts: hull, germ, and endosperm.
The outer skin has the physiological function of a semi-permeable septum and strongly protects the endosperm. Therefore, compared to the endosperm, the outer skin has a tougher fibrous tissue, has poor water absorption, and is extremely difficult to digest. Therefore, in the past, grains were eaten by removing the outer skin and milling the endosperm, or by boiling it as is.However, nutritional knowledge suggests that the outer skin of grains contains many vitamins and can be eaten as rice. In addition, as it has recently become clear that the fibrous material that makes up the husk is extremely useful for the human body, research is being conducted in various fields to process the husk of grains along with the endosperm to make them easier to eat. Among grains, brown rice has a structure consisting of an ectosperm, an inner layer of the pericarp called the bran layer,
Continuing with the aleurone layer, the inside of the aleurone layer is composed of endosperm and germ made of starch grains, and the outer skin, especially the seed coat, has the physiological function of a semi-permeable diaphragm and strongly protects the endosperm. ing. In other words, the outer skin has poor water absorbency compared to the endosperm, and for this reason, brown rice has been soaked in water for a long time and then cooked using a pressure cooker or by twice-cooking. However, even when rice is cooked using this method, there are disadvantages such as the taste is poor, the outer skin part is difficult to digest in the body, and necessary nutrients are not digested and absorbed, so that the rice cannot be cooked to a satisfactory degree. For this reason, although brown rice is nutritionally superior to polished rice, until now it has only been widely used by some enthusiasts. However, as the trend toward natural foods has increased in recent years, there has been an increasing demand for easy-to-cook brown rice, and research on this topic is being conducted in various fields. One of these is to increase the water absorption of brown rice.
For example, in order to cause cracks in the outer skin,
151354, a method of pressing brown rice with a roller as seen in JP-A-52-94442, JP-A-54-32643
There is a method of drying with hot air at 105 to 130°C followed by rapid cooling, as in JP-A-54-119043, and a method of storing brown rice in a rotating mesh basket while stirring the basket to prevent the brown rice from burning. Method of heating or JP-A-56-
As in No. 99757, a method in which brown rice is heated with superheated steam and expanded to an apparent specific gravity of 0.50 to 0.75, causing cracks in the outer skin of brown rice and making the inner germ part porous to increase water absorption. etc. have been proposed. All of the above methods make brown rice easier to eat by creating cracks in the outer skin of the brown rice, but these methods are not necessarily satisfactory.For example, pressing the brown rice with a roller Regarding the method, it tends to cause broken rice, and the temperature is 105-130℃.
Methods in which brown rice is rapidly cooled after drying with hot air or methods in which brown rice is heated in a rotating mesh basket oxidize the oil and fat in the brown rice, giving the cooked rice a strange odor. Regarding the heating method, the outer skin and endosperm of brown rice become porous or swollen, and the nutrients such as vitamins B ₁ , B ₂ , minerals, etc. that should be naturally present in that part, especially the outer skin, are
There are disadvantages such as release and reduction of taste sensation. In addition to the above-mentioned drawbacks, in conventional brown rice, the difference in ease of cooking between the outer skin and the endosperm is difficult to reduce no matter what rice cooking technology is used, which is a major drawback. That is, since the outer skin is difficult to digest, if rice is cooked for a long time in a high-pressure cooker or the like, the endosperm becomes softer than the outer skin becomes soft, resulting in a gruel-like texture that lacks texture and tastes extremely bad.
In order to solve this problem, it is necessary to reduce the difference in ease of cooking between the outer skin and the endosperm. In view of the following, this invention was developed as a result of intensive research in order to make the outer shell of grains easier to eat.The present invention was developed by soaking grains before germination in water, warm water, or humidified air to absorb moisture, and increasing the expansion rate to 17. After expanding to ~50%, this expanded grain is frozen at a low temperature of -20°C or lower, and then compressed to the extent that cracks and cracks occur in the outer skin while maintaining the frozen state. The intended purpose was achieved. In particular, according to this invention, brown rice is frozen in an expanded state due to moisture impregnated inside, and then compressed while maintaining the frozen state. At the same time, the fibers of the outer skin are cut and the water absorbency of the outer skin area is improved. On the other hand, the endosperm does not become porous,
Therefore, the difference in ease of cooking between the outer skin and the endosperm can be reduced, and the ease of eating can be increased. Furthermore, according to this invention, the outer skin does not swell and the endosperm does not become porous, so the nutrients and taste contained in the outer skin and endosperm are not lost, and the oils and fats contained in the endosperm are not lost. Since it does not oxidize, there is no need to worry about the rice getting a strange odor. The brown rice of this invention will be specifically explained below. The brown rice is left as is or after being lightly washed with water, and the brown rice is expanded in volume at an appropriate temperature in the presence of moisture. In this case, the expansion is performed at an expansion rate of 17 to 50%, preferably 35% or more, and the volume expansion treatment is preferably 18%.
This is done by soaking brown rice in water or hot water at a temperature of about ~40°C, but it may also be done by soaking brown rice in warm, humidified air at a temperature of about 18 to 50°C, or by soaking the brown rice as appropriate. A combination may be used. When the brown rice used here is sown, it is in a pre-germinated state, and if it absorbs moisture at the appropriate temperature, it will expand due to its physiological effects. Note that the expansion rate is expressed as a percentage of brown rice capacity expanded by water - brown rice capacity/brown rice capacity,
The reason why the expansion rate is set to 17 to 50% is that if it is less than 17%, sufficient compression effect cannot be obtained, and if the rice is compressed forcibly, broken rice will result. Moreover, if it is more than 50%, the rice will germinate and the texture and aroma will be lost when the rice is cooked. After volumetric expansion, it is dehydrated and the expanded brown rice is immediately stored in a freezer or the like for freezing treatment. The above dehydration can be carried out efficiently by using a centrifugal separator. The freezing temperature is -20°C or less, the lower the temperature, the more effective it is, but a temperature of about -20 to -70°C is appropriate. This freezing process allows the brown rice to be completely frozen down to the center. In order to make the completely frozen brown rice into pieces as described above, a light impact or stirring is performed. Next, the brown rice is stored in a compressor while being kept in a frozen state, and compressed at -5°C or lower, preferably -20°C or lower. Specifically, brown rice that has been frozen in a freezer is broken into pieces, then stored in a compressor in the same freezer, and compressed at a temperature similar to the above-mentioned freezing temperature. Compression processing is performed within a compression ratio of 3 to 20%. Here, the compression ratio is expressed as a percentage of expanded brown rice capacity - compressed brown rice capacity / expanded brown rice capacity. No cracks or cracks occur,
Moreover, when it is 20% or more, a lot of broken rice occurs, and the brown rice becomes powdery. If the compression ratio is within the range of 3 to 20%, rather than performing compression once or twice at a high compression ratio, compressing force is applied to the brown rice grains from multiple directions and the compression ratio is relatively low (7 to 12%). %) multiple times (e.g. 2
~10 times) can more effectively cause cracks, cracks, etc. in the outer skin of brown rice. A specific method of compressing the brown rice grains multiple times so that compressive force is applied from multiple directions is to apply an impact to the brown rice compressed in the compressor, break it into pieces, take it out from the container, and then compress it again. The brown rice that has been compressed in the presser is subjected to compression processing by being fed into the presser, and without being taken out of the pressurizer, the compressor is subjected to an impact to break it up into pieces and the inside of the container is stirred. Examples of methods include compression processing. In addition, when compression is performed multiple times as described above, the pressing force of the compressor becomes smaller as the compression is repeated even if the compression rate is the same. The above compression operation is carried out at -5℃ or below, as mentioned above.
Preferably it is carried out at -20°C or lower. If the temperature is -5°C or higher, it will not be possible to process the brown rice without causing cracks or fissures in the outer skin of the brown rice. Furthermore, the lower the temperature of the compression operation by -20%, the more effectively cracks and fissures occur in the brown rice, and as a result, the taste of the cooked brown rice becomes better. However, on the other hand, the lower the temperature, the more pressure is required to obtain the above compression ratio, so in reality it is -20 to -
Ideally, the compression process is carried out at a temperature of 40° C. using a compressor with a pressurizing capacity of 80 to 100 kg/cm ³ . Although the above explanation is about brown rice, it can also be applied to grains that have the same hull and endosperm as brown rice, such as wheat, barley, pigeon oats, and corn, and in this case, both the expansion rate and compression rate are different from brown rice. It can be done within a similar range. In addition, if wheat, etc. is treated according to the present invention before the flour milling process, fine fibers such as the outer skin and nutrients will be included in the flour in addition to the germ, and the nutritional balance can be improved. . Examples of this invention will be shown below. Examples 1 to 15 were expanded and compressed under the following conditions, and the results are shown in the table below. In the table below, 1 compression process has a pressurizing capacity of 100Kg/cm ²
The compression process was carried out at a temperature similar to the freezing temperature. 2. Regarding the incidence of bran and broken rice, less than 1% was rated A, 1 to 2% was rated B, and 3% or more was rated C. 3. Rice cooker SR-3F manufactured by N Company was used for cooking the rice, and the amount of water added was 1.8 times that of the treated brown rice. The texture and aroma were judged by a panel of 5 tasters: A was good for the texture, B was good, and C was better than regular cooked brown rice, but the hardness of the outer skin stuck to the mouth. , Unfit to eat was rated D. 4 Furthermore, as processed brown rice, 176cc,
156 g was used, and the humidity was brought to a saturated state during the expansion treatment by heating and humidification.

【table】

[Table] According to the results shown in the table above, -25%
The following compression process is preferred. Furthermore, in the expansion treatment, it is clear that the expansion rate is preferably 35% or more, and at the same time, the water absorption rate of brown rice during the expansion treatment is in the range of 13.8% to 26.4% (by weight) in Examples 1 to 15. It was hot inside. In addition, when the above Examples are arranged in descending order of results, Examples 7, 5, 8, 12, 6, 3, 13, etc. are obtained. Example 14 Brown rice obtained in Example 13 and JP-A-56-99757
The brown rice obtained by the easy-to-cook brown rice production method (trade name: Neo brown rice) was cooked in the same manner as in the above example with the same amount of water added, and the texture, aroma, ease of cooking, shape retention, etc. were compared. The texture and aroma were evaluated in the same manner as in the above examples. The results are shown below.

[Table] As is clear from the above results, Honhanmei brown rice (Example 13) is slightly inferior in ease of cooking compared to brown rice B, but it is superior in terms of texture, aroma, etc. Ta. Example 15 Two sets of brown rice (156g, 176cc) were added to 18℃ water for 2.5 minutes.
Expanded brown rice (177.5g, 216cc) was obtained by soaking for a period of time.
The water absorption rate is 13.8% (weight) and the expansion rate is 22.7%.
It was hot at capacity. These two sets of expanded brown rice are completely frozen at -27℃ and -12℃, respectively, and then each brown rice is placed in a compressor at the above freezing temperature and compressed at a compression ratio of 12%. After compression, the brown rice is compressed. It was taken out from the container, fed back in, and compressed at the same compression ratio as above, and this operation was repeated four times. In this case, the average value of the final pressing force of the compressor required for compression, the generation rate of bran on a 1.5 mm mesh sieve,
The table below shows the results of comparing the texture of cooked rice at freezing temperatures of -27°C and -12°C. The cooked rice was obtained by increasing the water content to 1.6 times the volume of brown rice and cooking the rice in the same manner as in the above example.

【table】

[Table] As is clear from the above results, A had better texture than B, and no particularly noticeable broken rice was observed. Therefore, the lower the temperature during compression treatment, the better.
-20% or less is ideal. This is presumed to be because the lower the temperature, the harder the expanded brown rice becomes, effectively causing cracks and cracks. However, on the other hand, it is clear from the above results that the lower the temperature becomes, the more the pressure applied by the compressor increases to compress brown rice (in the case of -27℃,
The average value of the final pressing force is 75.7Kg/cm ² , 41Kg/cm ² at -12°C). Therefore, a compressor having a pressurizing capacity of about 80 Kg/cm ² or more, preferably about 100 Kg/cm ² is used. Example 16 Wheat grains were immersed in water at 18°C for 6 hours to expand their volume by 45%, and after draining, they were completely frozen in a -25°C freezer, and then the frozen wheat grains were broken up and placed in a compressor. The compression operation was repeated 10 times at a compression ratio of 10%. As a result, wheat grains with appropriate cracks and cracks in the outer skin were obtained. When the wheat grains were milled using a conventional flour milling process and sectioned, it was possible to obtain flour in which finely ground husk was mixed into the flour. This finely ground husk has cracks according to the present invention, so when it is processed into bread, noodles, etc., cooked, and eaten, it is further divided by the cracks and can be digested without any trouble.

Claims (1)

[Claims] 1. Cereals in which the germ is surrounded by a husk are immersed in water, hot water, or humidified air before germination to absorb water and expand to an expansion rate of 17 to 50%. After that, the expanded grain is frozen at a low temperature of -5°C or lower, and then compressed to the extent that cracks, cracks, etc. occur in the outer skin while maintaining the frozen state. Hull treatment method. 2. So that compressive force is applied to the grain from multiple directions,
2. A method for treating grain hulls according to claim 1, which comprises performing compression treatment multiple times.