JP4324483B2 - Method and apparatus for processing fine foamed rice - Google Patents

Description

  The present invention relates to a processing method and apparatus for high-quality finely-foamed rice that is finely foamed by absorbing rice taste components contained in a paste layer of rice grains.

  In addition to the usual rice varieties provided in the general market such as brown rice and polished white rice, various types of rice such as non-washed rice, quick-cooked rice, pregelatinized processed rice, and processed instant cooked rice have been sold recently. Of these, pregelatinized rice is obtained by changing the starch of rice grains from β-type to α-type and fixing it, and restoring it by adding water or hot water, and is also called dry rice. This pregelatinized rice is preheated to a high degree of pregelatinization of 90% or more, cooled and dried by vacuum depressurization, and can be sharpened in just half the normal time by adding a certain amount of water. It has various advantages such as being able to cook rice easily and becoming delicious rice with a uniform taste and being able to be stored for a long time.

  As an example of a method and apparatus for obtaining such pregelatinized rice, one disclosed in Patent Document 1 is known. In the method and apparatus according to Patent Document 1, the washed raw rice is sufficiently immersed, the moisture on the peripheral surface of the rice grains is adjusted to a certain amount, and then heated by microwave irradiation in an airtight container, and the vacuum decompression container is used. The water content is adjusted to a range of 20 to 40% by reducing the pressure and cooling and drying.

  As another example, “a method for producing fast-cooked processed rice” according to Patent Document 2 is also known. This quick-cooked processed rice is not half-cooked fast-cooked rice but is a kind of so-called pregelatinized rice, and the pregelatinization is 90% or more. In this method, after primary processing to make moisture 20-25% by microwave heating and vacuum cooling, it is immersed and dehydrated in a solution containing starch degradation products, and then moisture is made 30-50% again by microwave heating. Secondary processing is performed, and the moisture contained by the secondary processing is used as inert moisture to enable long-term storage.

  By the way, compared to other processed rice, pre-treated rice does not need to be washed (water lab), soaked, and just by adding water, cooked rice with good taste and flavor can be made in half the normal time and can be stored for a long time. It has various advantages such as being possible. However, as in the above-mentioned Patent Document 1, the conventional pregelatinized rice is always washed in water and immersed in water at an early stage of processing. The reason is as follows. Refined milled rice is ground milled with 98% or more of the shell and paste layer (so-called milled portion) by milling to be polished rice with a milling degree of 38 to 41, but a part of the paste layer is extremely small. A small amount remains.

  When the fat and protein in the paste powder layer that remains in a small amount become old, an oxidative phenomenon that rots occurs, and the fat cannot be decomposed by cooking rice, so it cannot be cooked deliciously. For this reason, when cooking normal rice, it is thought that it is necessary to remove the paste-powder layer beforehand by water washing as much as possible. In the case of pregelatinized processing, the idea that the paste layer needs to be removed by washing with water is applied to the first stage of processing, and therefore washing and soaking are always required. It is.

  In general, polished rice generally has a good taste about 10 days after milling, but after that, the taste deteriorates greatly with the passage of 20 days and 30 days. In this way, if the fat and protein that are oxidized and spoiled remain attached, the taste deteriorates. However, even if the paste layer is cured after curing, if it can be decomposed by heating, the effect on the taste will be reduced, so it is not always necessary to remove the paste layer, but in general it is easy to remove the paste layer. Since it cannot be decomposed, it has always been removed by washing with water.

In addition, when the pregelatinization treatment is performed, it is common to immerse in water after washing in the initial stage of the treatment process. However, if the amount of rice to be pregelatinized increases, A large amount of water of several hundred tons per day is used, and there is a big problem that a large amount of water is consumed and the treatment cost is increased due to this, and the treated water is discharged to the outside as it is. Then, environmental pollution occurs, and therefore it becomes a problem how to purify and discharge it.
JP-A-5-56760 Japanese Patent Laid-Open No. 11-56267

  This invention pays attention to the various problems described above, washing with water in the processing step of obtaining the pregelatinized rice from the raw rice, performing the pregelatinization processing without immersing, and without water sharpening during cooking, It is an object of the present invention to provide a processing method and apparatus for finely foamed rice that can be obtained by simply adding water to produce delicious rice in less than half the normal time and can be stored for a long time.

  In consideration of the above-mentioned problems, the present invention polishes the surface of a predetermined amount of raw rice containing brown rice or milled white rice to remove white rice from the surface, and the brown rice removes surface cellulose to facilitate water absorption. After adding a predetermined amount of moisture corresponding to the amount lost by microwave irradiation, heating, and cooling drying in the subsequent process to the raw rice, and stirring in a vacuum reduced state so that the adsorbed water absorption of the moisture is uniform to the rice grains, Return to atmospheric pressure to absorb the predetermined amount of water, heat the raw rice by irradiating it with microwaves in an airtight heating chamber, finely foam the moisture vapor in the rice grains, and further heat the heated rice Is transferred to a vacuum vessel, subjected to a predetermined pressure reduction treatment, vacuum-cooled and dried, and adjusted to a moisture content within a predetermined range by this vacuum-cooled drying.

  Moreover, as an apparatus for carrying out this processing method, a rice polishing machine that polishes a predetermined amount of raw rice containing brown rice or polished white rice to remove cellulose on the surface of the brown rice or white rice surface, and polished raw rice and back Add a predetermined amount of water equivalent to the amount lost by microwave irradiation, heating and cooling drying in the process, stir in vacuum reduced pressure so that the water adsorbed water becomes uniform in the rice grains, then return to atmospheric pressure and return to atmospheric pressure A vacuum stirrer that absorbs water of water, put the raw rice in a heating chamber, irradiate with microwaves, steam with steam from the heated rice grains to make fine foamed rice, transfer it to a vacuum vessel The pregelatinized processing means for vacuum cooling and drying by this reduced pressure is provided in the post-process, and it is configured to absorb the residual rice bran component and water after the rice polishing into the rice grain and adjust the moisture content within a predetermined range. Adopt processing equipment for fine foamed rice It can be.

  In the processing method and apparatus for finely foamed rice of the present invention that performs the above-described treatment, the raw rice is washed and submerged without being soaked, and the raw rice is polished and absorbed, and microwave irradiation and cooling and drying by reduced pressure are used for α The pregelatinized processing is carried out. Therefore, this processing method is a dry processing method. In the pre-treatment water absorption action, the rice taste component (so-called rice bran component) and a predetermined amount of water remaining on the surface of the rice grain after the polishing process were absorbed into the rice grain and microfoamed by microwave irradiation. Later, when the rice grains are semi-solidified by cooling and drying under reduced pressure, the rice taste components are confined in the rice grains, so that delicious rice is obtained.

  Polishing in the pretreatment step is performed as a surface treatment for removing the paste powder layer by polishing as much as possible to facilitate water absorption. In general, rice contains 13.5 to 15% of moisture, and the moisture content varies depending on the dryness of brown rice, the treatment of rice such as old rice, old and old rice, mochi rice, and crushed rice, the progress and type, etc. Refined polished rice is generally shipped with a moisture content of 14.5-15%. Therefore, when water is evaporated in the subsequent process, the water evaporates by heating, and the water that is discharged and lost by cooling and drying by decompression may be added in an amount corresponding to this in the pretreatment process. It does not necessarily mean that it must be washed or dipped in the process.

  It is desirable that the moisture content in the predetermined range is set to a value similar to that of the original raw rice. This is because the moisture content of the harvested natural raw rice is the most reasonable and suitable for long-term storage. For example, if the moisture content is 40% or more, problems may occur in long-term storage. However, when it is desired to adjust the moisture content to be equal to or higher than that of the original raw rice, it may be adjusted to increase or decrease the amount of water absorbed during the stirring action. Moreover, when adjusting to the moisture content of the predetermined range with respect to the said fine foamed rice, the predetermined range is as follows. That is, milled white rice is shipped at a moisture content of 14.5 to 15%, so that the above processing step adds 6 to 8% water at the initial stage.

  This is because 4-5% of water is lost at the stage of microwave irradiation (including unevenness), and 2-3% of water is lost by cooling and drying, and the total amount of water lost is 6-8%. Because it becomes. Accordingly, the water corresponding to the lost water is adjusted to the same level as that of the raw rice by adding water in advance, but it is difficult to adjust the water content accurately as in the above-mentioned numerical value in actual processing. For this reason, it is desirable that the moisture content in the predetermined range is approximately the same as that of the original raw rice, but the allowable range is 13 to 16%, and the most desirable range is 13.5 to 15%, the same as the raw rice. Yes, such a range should be handled in each invention as the same level as the original raw rice.

  In the polishing treatment, the brown rice cellulose or the white rice paste powder layer is removed as much as possible with, for example, a screw type polishing machine. However, since there are many fine streaks on the surface of brown rice / white rice grains, some remain along the streaks and it is difficult to remove 100%. However, since rice components such as sugars and fats and oils contained in the paste powder layer remaining in a minute amount are absorbed into the rice grains by subsequent stirring and mixing and cooling and drying, some residue may remain. Rather, by leaving some residue and absorbing and confining it in the grain of rice, it is unexpected that the taste of rice becomes more tasty and more delicious than in the case of pure starch components only like conventional polished rice Quality rice is obtained.

  The processed rice obtained by the above processing is made by polishing the raw rice of brown rice or milled white rice and removing the cellulose or white rice surface wrinkles on the surface of the brown rice by adding a predetermined amount of water to absorb water, and the raw rice is airtight In a heat-sensitive heating chamber, which is microfoamed by heating with microwave irradiation, and the rice grains are α-ized by the steaming action of the steam at that time. It is a fine foamed rice that has been processed to contain moisture with a moisture content. The processed rice thus treated is handled in the same way as ordinary brown rice and polished white rice, but the surface of the rice grains is finely foamed, so that the normal white rice is transparent white, whereas the styrofoam colored It is such white.

  The processing method and apparatus according to the present invention sufficiently polishes and removes the unpolished cellulose or milled rice paste powder layer (rice bran) of raw rice, adds water to this, and stirs and mixes in a vacuum under reduced pressure to give a predetermined amount of moisture. Absorb and microwave irradiation in the heating chamber to give heat, steaming action, and then α process to finely foam the surface of the rice grain, then semi-solid by rapid vacuum cooling, a small amount of paste powder layer remaining in the rice grain Since it is trapped and solidified to obtain fine foamed rice, it is not necessary to wash and dip in the pretreatment stage generally required for pregelatinization treatment, and it is possible to obtain pregelatinized rice with a moisture content within a predetermined range. Therefore, this pre-gelatinized rice does not require water sharpening or soaking even when cooking rice, and by simply adding water, it becomes delicious rice in less than half the normal time and can be stored for a long time. Having the advantages of rice It has the advantage of providing innovative processed rice.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic configuration diagram of an apparatus for carrying out the method for processing fine foamed rice according to the present invention, and FIG. 2 is a plan view. As shown in the figure, raw rice such as brown rice or refined polished rice is temporarily stored in a rice storage silo 1 equipped with a cutting mechanism for appropriately mixing rice and cutting out a predetermined amount of raw rice. C ₁ and C ₂ are conveyors for carrying the raw rice from the rice storage silo 1. Unloading raw material rice is polished in Ken rice machine 2, the surface layer of cellulose if brown rice, the rice Norikoso (bran) is removed, a predetermined amount is contained in quantity container 3, following by a conveyor C ₃ To the next process. The details of the rice polishing machine 2 will be described later.

Rice quantification container 3 conveyed is conveyed by the conveyor C ₃ and transferred to a vacuum mixer 5 with a predetermined amount of water. The predetermined amount of water is an amount corresponding to the amount of water lost by microwave irradiation, heating, and cooling / drying by a microwave irradiator in the subsequent process, and details thereof will be described later. FIG. 4 shows a schematic configuration of the vacuum stirrer 5. 5a is a vacuum tank, 5b is a rotating drum, 5c are doors, connecting tube to the vacuum pump 5d is not illustrated, 5e vacuum meter, 5 _M denotes a motor.

  The raw rice and water are stirred in the vacuum stirrer 5 so that the water is evenly adhered to the peripheral surface of the rice grains and the water is partially absorbed. When the raw rice and water are agitated, the inside of the rotating drum 5b is depressurized by vacuum suction, the water in the rice grains partially flows out and mixed with the outside water, the agitation is stopped, and the inside of the drum is returned to atmospheric pressure. Moisture is absorbed and more water than the original raw rice is contained inside. Details will be described later.

The raw rice to which moisture has adhered and absorbed is taken out from the vacuum stirrer 5, heated in the heating container 6, and then sent to the electromagnetic heating chamber 7. In this electromagnetic heating chamber 7, microwaves are irradiated by the provided microwave irradiator, and water is evaporated from the raw rice while the raw rice is α-ized (finely foamed) by heating and steaming by this irradiation. The surface is made fine foam. The microwave irradiator used is composed of a plurality of microwave oscillators, for example, those having an oscillation frequency of 2450 MHz and an output of 1.2 kW. Thereafter, the raw rice is sent to the vacuum cooling chamber 8 by the conveyor C ₄ , where it is depressurized and vacuum-cooled to form a semi-solid processed rice.

C ₅ is a conveyor for sending processed rice to the next process, and the processed rice is sent to the loosening machine 9. In this loosening machine 9, since the starch that flows out when the processed rice is vacuum-cooled wraps around the surface of the processed rice, it is gelatinized and hardened, and the rice grains are partially adhered to each other. Done. C ₆ is a conveyor that sends processed rice to the next process. The processed rice that has been sent is weighed by the weighing machine 10, and then packed by the automatic packaging machine 11, and the automatically packed processed rice is boxed by the conveyor C _7. 12 and boxed. In addition, for long-term storage of 6 to 12 months, it is preferable that the deoxidized material is enclosed in an airtight package, packaged, and packaged.

Fig. 3 shows the schematic configuration of the Kenken machine. As shown in FIG. 2A, the rice grinder 2 has a motor 24 _M in which two sets of screw-type supply rolls 24 are arranged in parallel to each other in a raw material rice supply path 23 following an upper hopper 21 in a casing 20. The feed roll 24 is driven by the above-mentioned driving, the flow rate of the raw rice dropped from the hopper 21 by the flow rate adjusting roll 22 is adjusted, the raw rice is fed at a predetermined feed speed, and the motor is driven by the polishing rice screw 25 provided at the lower stage. It is configured so that the raw rice is polished by a large number of blade edges on the outer surface of the screw while feeding the raw rice in the direction opposite to the feed direction of the feed roll by driving 25 _M , and the polished raw rice is discharged from the discharge path 2 _L to the outside. ing.

Cellulose on the surface layer of brown rice that has been ground and dropped by the blade edge of the milling screw 25 or the rice bran on the surface of the white rice falls from the separation screen 26 under the milling screw 25 and is stored in the straw chamber 27. The separation screen 26 is set to have a mesh with a size that is small enough that the raw material rice does not fall and the removed and crushed pieces are dropped, and is provided for capturing the pieces. . The soot chamber 27 is formed as a negative pressure chamber for dropping soot, and a suction blower 29 is driven by a motor 29 _M through a filter (F) 28 to apply suction pressure. To do through. Reference numeral 31 denotes an adjustment dial for adjusting the load of the drive motor of the polishing screw 25.

  In the processing apparatus according to the embodiment configured as described above, the processing is performed as follows. In order to facilitate understanding of the following processing steps, FIG. 5 is a flowchart showing the flow of the steps. The raw rice includes both brown rice and polished white rice, but the following mainly describes the case of processing polished white rice. In the case of brown rice, it is processed in accordance with polished white rice. The raw material rice transferred from the rice storage silo 1 is immediately sent to the rice mill 2 without being washed or immersed in water, and the rice bran surface is removed here.

In the rice polishing machine 2, in the case of general unwashed rice and processed rice, the amount of soot corresponding to the soot component removed by washing with water is removed, and the surface is treated so that water easily adheres to the peripheral surface of the rice grain. . The moisture content of the raw rice milled white rice is 14-15% when it is milled and shipped, but the moisture content of the white rice does not change when it is polished by the rice mill 2. The amount discharged from Ken US machine 2 is accommodated in quantity container 3 in the set amount of about 5 to 10 kg (generally an amount which is treated as one hook component), it is sent to a vacuum mixer 5 by a conveyor C _3. Further, water is accommodated in a quantitative container (not shown) and simultaneously sent to the vacuum agitator 5.

  The predetermined amount of water contained in the water quantitative container is, for example, about 300 cc with respect to 5 kg of white rice, the total amount of which is absorbed by the rice grains after stirring with the vacuum stirrer 5, and the micro- It is the amount corresponding to the amount of water lost by evaporation to the extent that it returns to the moisture content of the original raw rice by wave irradiation and vacuum cooling. In the vacuum stirrer 5, the raw material rice and water are stirred in a vacuumed state. This vacuum suction is set to a state of 700 to 730 mmHg, for example, as a vacuum pressure. In the vacuum suction, the water in the rice grains partially comes out and is mixed with the water around the rice grains.

  Then, after completion of the stirring for a predetermined time, the lid of the vacuum stirrer 5 is opened, and the process waits for one hour. At that time, the inside is returned to the atmospheric pressure, and the predetermined amount of water described above is contained in the rice grains, and the whole amount of water is absorbed. After the total amount of water is sufficiently absorbed by the rice grains, the raw rice is taken out and placed in the heating vessel 6 where it is preheated and then irradiated with microwaves in the electromagnetic heating chamber 7.

  In the case of the above microwave irradiation, the effective heating distance of the microwave is within about 200 mm from the microwave oscillator in the example shown in the figure, and the raw rice is formed in a disk shape with a thickness of about 70 to 90 mm in advance for uniform heating. It is placed in the electromagnetic heating chamber 7 so as to be within the effective heating distance in the raised state. When microwaves are irradiated and heated, the moisture in the rice grains goes out as steam. This steam also has a steaming action. Accordingly, the product temperature of 110 ° C. or higher is obtained by heating and steaming action by microwave irradiation, and processing with an α degree of 90% or higher is performed.

  In addition, during the microwave heating, the rice grains swell with rapid and rapid heat, micropores are formed on the surface, and fine bubbles are generated inside, and the fat and protein of the paste layer decomposed with water vapor are of course other. In addition, the decomposed components are absorbed into the rice grains in place of the moisture released to the outside. Therefore, even if the raw rice is not washed or dipped in the first treatment step, there is no influence on the pregelatinization process, and the taste does not deteriorate due to the oxidation of fat and protein.

  Note that 4 to 5% of water is released by evaporation of water vapor. Microwave heating is performed in the range of 8 to 12 minutes, and when the temperature of the raw rice is kept at a temperature around 110 ° C. for 3 to 5 minutes and then cooked uniformly, the microwave heating is then stopped for 2 to 3 minutes. Steam it. The raw rice whose temperature has dropped to 100 ° C. in this steaming process is transferred to the vacuum cooling chamber 8. When the room air and water vapor are exhausted by the suction pump in the vacuum cooling chamber 8 and rapidly depressurized, it is cooled to the boiling point under ultra-low pressure and suddenly reaches the inside of the rice grain, and the moisture in the rice grain (2 to 3%) ) Is vaporized and released.

Also, most of the lipid oxidative aldehydes have a boiling point of 179 ° C. under atmospheric pressure (1 atm), but when the pressure is lowered to a low pressure of 1.3 × 10 ³ Pa (10 Torr), it boils at 62 ° C. . Therefore, moisture and aldehydes are vaporized and released, but other rice flavor components are further absorbed into the rice grains by this cooling, and the fine pores and fine bubbles contract and become semi-solid to obtain fine foamed rice. . In this case, since the rice taste component of the paste powder layer, which has been removed as much as possible by conventional water washing and immersion, is absorbed in a very small amount inside the rice grain, the resulting finely foamed rice greatly improves the rice taste ( The so-called excitement).

  And the aldehydes that cause rotting odor are almost completely removed, and the water is returned to the level of the raw rice in the natural state at the time of semen, so the rice taste is good, the nutritional value is high, without water polishing, Fine foamed rice having various advantages of being delicious rice in a short time and being able to be stored for a long time is obtained. The finely foamed rice obtained in the above embodiment dissolves and separates a small amount of paste powder layer remaining along the streaks on the surface of smoked white rice, and absorbs and impregnates this trace component in the rice grains in the alpha process. It has been made.

  Therefore, the paste powder layer to be impregnated has a small amount of particles scattered in the rice grains in a discrete manner and is not included in a layer form at a predetermined depth, and the depth is also different. Further, when brown rice is used as the raw rice, the surface cellulose of brown rice and the paste powder layer under the brown rice are also polished and removed by a grinding machine, so that the same fine foamed rice is obtained.

  The processing method and apparatus for fine foamed rice according to the present invention can cook brown rice or milled white rice in a short time without water polishing, and can provide delicious rice. It can be used widely for various purposes, such as for rice, for nursing homes, school meals, hospitals, restaurants, etc.

Overall schematic configuration diagram of the pregelatinization processing apparatus of the embodiment Same as above Diagram showing the schematic configuration of a Kenken machine Diagram showing schematic configuration of vacuum stirrer Flow chart showing the order of alpha processing process

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice storage silo 2 Rice polishing machine 3 Fixed container 5 Vacuum stirrer 6 Heating container 7 Electromagnetic heating chamber 8 Vacuum cooling chamber 9 Unraveling machine 10 Weighing machine 11 Automatic packaging machine 12 Box packing machine

Claims (4)

  Polishing the surface of a predetermined amount of raw rice containing brown rice or polished white rice, white rice removes surface koji, brown rice removes cellulose on the surface layer to facilitate water absorption, this raw rice is irradiated with microwaves in the subsequent process, heated, Then, a predetermined amount of water corresponding to the amount lost by cooling and drying is added and stirred in a vacuum under reduced pressure so that the adsorbed water of the water becomes uniform in the rice grains, and then returned to atmospheric pressure to absorb the predetermined amount of water. The raw rice is heated by irradiating microwaves in an airtight heating chamber, the steam of moisture in the rice grains is finely foamed by heating, and the heated rice is further transferred to a vacuum container and subjected to a predetermined decompression treatment. A method of processing finely foamed rice comprising: vacuum cooling and drying, and adjusting the moisture content within a predetermined range by vacuum cooling and drying.   A grinding machine that polishes a specified amount of raw rice containing brown rice or polished white rice to remove cellulose on the surface of the brown rice, or wrinkles on the surface of the white rice, and microwave irradiation, heating, and cooling drying of the polished raw rice and subsequent processes A vacuum stirrer that adds a predetermined amount of water corresponding to the amount lost in the above and stirs the water adsorbed water to be uniform in the rice grains and then returns to atmospheric pressure to absorb the predetermined amount of water. Is put into a heating chamber, irradiated with microwaves, steamed with steam from the heated rice grains to make fine foamed rice, transferred to a vacuum container and subjected to a predetermined pressure reduction, and then the alpha process to vacuum-cool and dry by this pressure reduction A processing apparatus for finely foamed rice, comprising means for a post-process, configured to absorb the residual rice bran component and water after polishing into the rice grains and adjust the moisture content within a predetermined range.   3. The polishing machine according to claim 2, wherein the raw rice dropped from the hopper is polished with a number of blade edges on the outer surface of the screw with a screw-type polishing screw to remove cellulose or cocoon components. The processing apparatus for fine foamed rice as described in 1.   By polishing the raw rice of brown rice or milled white rice and removing the cellulose or white rice surface wrinkles on the surface of the brown rice, a predetermined amount of water is added and absorbed, and the raw rice is heated by microwave irradiation in an airtight heating chamber. The rice grains are made into fine foam and steamed by steaming at that time, and this is vacuum-cooled and dried by vacuum treatment to absorb the residual rice cake components in the rice grains so that the moisture content in the specified range is included. Fine foamed rice.

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