JP2004141009A - Method for producing frozen boiled rice, and the frozen boiled rice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide frozen boiled rice having voluminous feeling when served on a dish, uniformly heated, and having the same palate feeling as that of freshly boiled rice when thawed with microwaves. <P>SOLUTION: The frozen boiled rice is obtained by the following process: charging boiled rice prepared by a usual method into a boiled rice supply cylinder 1 functioning as a hopper; operating loosening net 3 having a wire diameter of 1.5-4 mm and a mesh size of 10-30 mm, in a direction orthogonal to the feeding direction of the boiled rice while continuously feeding the boiled rice to the loosening net 3; forming compound-grain massive boiled rice B via relative movements of the boiled rice supply cylinder 1 and the loosening net 3; and freezing the compound-grain massive boiled rice B in the usual manner. <P>COPYRIGHT: (C)2004,JPO

Description

実施例の凍結米飯は、図３に示されるように、皿５に盛ると、各複粒塊状米飯Ｂの間に空間Ｓが存在することから比容積が大きい。このため、マイクロウェーブ解凍時に、ボリューム感があり、通気性がよいことから水蒸気が米飯内にこもらず、各複粒塊状米飯Ｂも小さいことから均等に加熱されてべちゃつき感がなく、炊きたての米飯と同様の食感が得られた。
【００２８】
【発明の効果】
以上説明したように、本発明の凍結米飯の製造方法及び凍結米飯は、マイクロウェーブ解凍時に、皿に盛った際のボリューム感を有しつつ、均等に加熱されて炊きたてと同様の食感を有する。また、安定的に適正な粒数の米飯が得られるため製品のムラが少なく、大量生産ラインで製造可能なので、高い生産性を維持できる。さらに、凍結設備に撹拌機能がなくてもよいため、凍結機の洗浄が容易である。
【図面の簡単な説明】
【図１】本発明に係る複粒塊状米飯の製造装置の一例を示す概略図
【図２】図１のＩＩ−ＩＩ矢視図
【図３】本発明に係る複粒塊状米飯を皿に盛った状態の概略図
【符号の説明】
１…米飯供給筒、２…米飯投入コンベア、３…ほぐし網、４…冷却コンベア、５…皿、Ｂ…複粒塊状米飯、Ｓ…空間[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing frozen rice that freezes a plurality of rice grains in a lump and a frozen rice.
[0002]
[Prior art]
The method of producing frozen cooked rice is to cook rice and then quickly freeze using liquefied carbon dioxide, liquid nitrogen, low-temperature air, etc. while loosening the cooked rice grains, and freeze each grain of cooked rice in a rose shape. There is a method (for example, refer to Patent Documents 1 and 2).
[0003]
Frozen cooked rice is also known in which cooked rice is not in the shape of a rose, but a lump is frozen in the form of a single-grain mass of 1 g to 30 g. For this frozen cooked rice, a method of crushing a block of frozen cooked rice obtained by slow freezing into an appropriate size using a crusher or the like, or filling rice molds into a mold so that the size of each block becomes the target size. It is manufactured by a method of freezing (for example, see Patent Document 3).
[0004]
[Patent Document 1]
JP-A-50-89553 (pages 1 and 2)
[0005]
[Patent Document 2]
JP-A-63-279772 (page 2, page 5, FIG. 1, FIG. 5)
[0006]
[Patent Document 3]
JP-A-5-146264 (pages 2 to 4)
[0007]
[Problems to be solved by the invention]
However, the above-mentioned rose-shaped frozen cooked rice can be uniformly thawed in a stir-fry using a frying pan or the like because heat is uniformly applied to the cooked rice. In addition to the lack of volume when placed on a plate, because of poor air permeability, if no work such as stirring is performed during thawing, water vapor generated during thawing is likely to remain in the cooked rice, and the cooked rice will not stick. It has a ragged texture, and even if you eat it, you cannot get the same texture as freshly cooked rice.
[0008]
In addition, the above-mentioned double-grained cooked rice has a large number of crushed rice in the processing by the crusher, and the processing by the mold has a limit in the size that can be formed, and only a relatively large block of cooked rice can be formed. In wave thawing, since the lump is large, it is difficult to heat it evenly, and a portion that is overheated occurs.
[0009]
Therefore, the present invention provides a method and a method for producing frozen cooked rice, which can have a voluminous feel when placed on a plate, and can have a texture similar to that of freshly cooked rice even when cooked in a microwave. It aims to provide cooked rice.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing frozen cooked rice of the present invention comprises feeding cooked cooked rice into a cooked rice supply cylinder having a self-weight dropping function, and placing the cooked rice in a loosening net disposed close to an outlet of the cooked rice supply cylinder. The rice is fed continuously through the mesh of the unraveling net while the one or both of the rice feeding cylinder and the unraveling net are operated in the direction crossing the feeding direction of the cooked rice. It is characterized in that it is formed into a granular mass and the cooked rice formed in the double-grain mass is frozen. Moreover, it is desirable that the loosening net used in this manufacturing method has a wire diameter of 1.5 to 4 mm and a mesh size of 10 to 30 mm.
[0011]
The above method will be described for each step as follows.
[0012]
1. Rice Washing / Immersion / Cooking Step This step is not particularly limited. For example, polished rice is washed with water, then immersed in water for a predetermined time, and a predetermined amount of cooked water is added to the immersed rice to cook rice. If necessary, add the seasonings, emulsified fats and oils, secondary ingredients, etc. and cook rice. In this case, if the ingredients are large, there is a possibility that the ingredients will be clogged in the loosening net in the subsequent process. Therefore, the large ingredients are separately cooked and mixed after the loosening step. Further, a steaming step may be introduced after washing and dipping the rice and before cooking the rice.
[0013]
2. Step of Continuously Supplying Cooked Rice Cooked cooked rice is put into a cooked rice supply cylinder in which a loosening net is arranged close to the outlet, and is lowered by its own weight to be sequentially supplied to the loosening net. The rice cooker has a length necessary for the rice cooked to fall by its own weight, and it is preferable to turn the axis in the vertical direction in order to maximize its own weight drop function, but since it descends by its own weight, If so, it may be inclined. The cross-sectional shape of the cooked rice supply cylinder is not particularly limited, such as a circle, an ellipse, and a polygon. However, in the case of a polygon, cooked rice is likely to stay at the corners of the cylinder, so it is preferable to round the corners. Furthermore, since it is preferable to arrange the loosening net close to the outlet of the cooked rice supply cylinder because it is possible to reliably supply cooked rice, the outlet of the cooked rice supply cylinder is formed by rounding the tip end outward and folding the cooked rice. The effect of preventing kneading between the exit and the loosening net can be expected. As the charging of the cooked rice into the cooked rice supply cylinder, a method of intermittently charging the rice, or a method of continuously charging the rice by a conveyor or the like can be adopted. However, it is not preferable to forcibly press the rice from above using a jig such as a plate because the rice is easily kneaded at the wall surface of the supply cylinder or at the boundary between the supply cylinder and the loosening net.
[0014]
3. Unwinding process The cooked rice supplied to the unraveling net exerts a shear force on the rice passing through the mesh of the refining net due to the scraping effect of the loosening net slowly operating in a direction crossing the supply direction of the rice, for example, orthogonally. Works, the cooked rice is separated at the portion where the bonding between the grains is weak, and falls from the loosening net in a lump in which a plurality of about 3 to 10 grains are bound. The operating direction of the loosening net includes one-way motion, reciprocating motion, circular motion, and the like. One that operates in one direction includes an endless belt-like net or a continuously turning net. Note that the loosening net may be fixed, and the cooked rice supply cylinder may be operated in a direction crossing the direction of supply of cooked rice, or both the cooked rice supply cylinder and the loosened net may be operated in the same direction.
[0015]
The unraveling net is made of metal, the wire diameter is preferably 1.5 to 4 mm, and the mesh size is desirably 10 to 30 mm. Can be obtained stably. When the wire diameter of the net is smaller than 1.5 mm, not only is the strength of the unraveling net itself problematic, but also the cooked rice is sheared during unraveling, causing broken rice. On the other hand, if the thickness is larger than 4 mm, the rice is kneaded. If the mesh size is smaller than 10 mm, the cooked rice is clogged in the mesh, and the cooked rice is kneaded or broken during the loosening process. On the other hand, if it is larger than 30 mm, the size of the resulting double-grained cooked rice is not stable, and dumpling-like lumps are easily generated. Furthermore, by making the metal wire forming the net corrugated, shearing, kneading and the like of cooked rice can be reliably prevented. It is preferable that the waveform in the case of loosening the cooked rice obtained by cooking the general glutinous rice has a wave height of about 2 to 6 mm and a wavelength of about 8 to 20 mm.
[0016]
4. Cooling / Freezing Step The rice cooked in the form of a double-grain mass obtained by the unraveling step is cooled and frozen. The method of cooling and freezing is not particularly limited, but it is preferable to cool and freeze in a state where the double-grained cooked rice is scattered one by one, and in a state where the double-grained cooked rice overlaps or adheres to each other. Cooling and freezing should be avoided. In addition, it is important to avoid excessive agitation that further breaks up the double-grained cooked rice obtained in the loosening step.
[0017]
For this reason, for example, the double-grained cooked rice is dropped on a conveyer of a freezing machine such as a contact freezer and frozen as it is, or the double-grained cooked rice is dropped on a cooling conveyor, and is cooled to about 20 to 60 ° C. by cold air or the like. Liquefied carbon dioxide, liquid nitrogen, low-temperature air, etc. in a state where the formed double-grained cooked rice was prevented from further disintegrating It is preferable to perform a freezing treatment using a conventionally known freezing device.
[0018]
Furthermore, the frozen cooked rice obtained by the above-mentioned manufacturing method is characterized in that about 3 to 10 uncrushed grains are formed per double-grain agglomerate. In this case, a small amount of grains crushed by shearing may be included. In addition, the weight of each of the double-grain masses is 0.2 to 0.5 g. Furthermore, the present invention is characterized in that the double-grained cooked rice obtained by the above-mentioned manufacturing method is commercialized in a state of being mixed with single-grain cooked rice in a weight ratio of 50% or more.
[0019]
That is, when examining the size, shape, and distribution per product of the double-grain frozen rice, the double-grain massive rice obtained by the above-described manufacturing method preferably has a size of about 3 to 10 lumps. . If it is less than 3 grains, it is meaningless to form a lump, and if it exceeds 10 grains, it becomes a dumpling and the texture after thawing is not good. In addition, the shape is not particularly limited, but the shape of the lump obtained by the above-described manufacturing method tends to be a bale shape. Furthermore, if the weight ratio of double-grained bulk rice to single-grain cooked rice per product is in the range of 5: 5 to 10: 0 by weight, it will have a voluminous feel when put on a plate during microwave thawing. And has a texture similar to freshly cooked evenly heated.
[0020]
【Example】
1 and 2 show an example of an apparatus for unraveling cooked rice for producing double-grained cooked rice according to the present invention. The apparatus comprises a cooked rice supply cylinder 1 arranged with its axis oriented vertically. And a rice feeding conveyor 2 for feeding the cooked rice into the rice feeding cylinder 1 from above, and a loosening net 3 installed near the outlet of the rice feeding cylinder 1 and reciprocating in the direction orthogonal to the axis of the rice feeding cylinder 1. , And a cooling conveyor 4 disposed below the loosening net 3. The cooked rice supply cylinder 1 has, for example, a circular cross section with a diameter of about 25 cm, and has a lower end rounded and turned outward. The unraveling net 3 has a mesh size of 25 mm, and is made by knitting a stainless steel wire having a wire diameter of 2.2 mm so as to cross over the course, and has a corrugated surface. The loosening net 3 reciprocates in a horizontal direction at a speed of about 30 cm / sec with a stroke of 50 cm.
[0021]
To explain an example of producing a double-grain agglomerated rice using such a device, rice polished rice is washed and immersed, then water, seasoning and the like are added and cooked. 2 put rice on top. The temperature of the cooked rice on the cooked rice feeding conveyor 2 was about 80 to 90 ° C. The cooked rice on the cooked rice conveyer 2 was successively charged into the cooked rice supply cylinder 1 in sequence. The introduced cooked rice was lowered in the cooked rice supply cylinder 1 by its own weight, and was continuously supplied to the loosening net 3 reciprocating in the direction indicated by the arrow in FIG. When the cooked rice supplied on the unraveling net 3 passed through the mesh of the unraveling net 3, approximately 3 to 10 double-grained agglomerated rice B dropped on the cooling conveyor 4.
[0022]
After cooling the double-grained cooked rice B on the cooling conveyor 4 to about 40 ° C. with low-temperature air, it was frozen at −30 ° C. by a conventionally known rotary drum type rose freezing machine. Snow-like dry ice was used as the refrigerant of the freezer, and the stirring function was not used. When the frozen cooked rice is confirmed, it becomes three to about ten double-grain clumps of rice B maintaining the shape formed by the loosening net 3, and a single rose-shaped frozen cooked rice. The weight ratio with the frozen cooked rice was 8: 2.
[0023]
Comparative Example 1
Rice washed, immersed, and cooked in the same manner as in the example was cooled to about 40 ° C. on a cooling conveyor, and frozen at −30 ° C. using the same rotary drum-type rose-shaped freezer as in the example. Snow-like dry ice was used as a refrigerant for the freezing machine, and sufficient stirring was performed to freeze while loosening. The cooked rice after the freezing treatment was generally in the form of single roses.
[0024]
Comparative Example 2
Rice washed, immersed, and cooked in the same manner as in the example was cooled to about 40 ° C. on a cooling conveyor, and frozen at −30 ° C. using the same rotary drum-type rose-shaped freezer as in the example. Snow-shaped dry ice was used as the refrigerant of the freezer, and in order to prevent the ice-shaped dry ice from becoming loose as in Comparative Example 1, the stirring was kept to the minimum necessary for freezing while avoiding excessive stirring. The size of the cooked rice after the freezing treatment varied from small single rose to large fist, but more than 90% of the total weight was about 20g (equivalent to 400 grains). Was occupied.
[0025]
The chunks of cooked rice obtained in Comparative Example 2 were crushed by a crusher. In addition to crushing machines, there are two types of crushing machines: a crusher that crushes lump with rollers with appropriate clearance and a crusher with high-speed rotating blades like a juicer mixer. Roller type was used in order to prevent as much as possible. When the frozen rice after the crushing treatment was confirmed, it was possible to obtain about 3 to 10 double-grained chunks of rice. About 3 to 10 grains accounted for about 50% of the total weight.
[0026]
200 g of the frozen cooked rice obtained in each of the above Examples and Comparative Examples was placed on a plate and thawed in a microwave oven at 500 W for 4 minutes, and the percentage of broken rice, volume, and texture after thawing were confirmed. Table 1 shows the results. In addition, the method of investigating the broken rice ratio is a value obtained by measuring the weight of broken rice per product and dividing by the total weight. The method of investigating the sense of volume was as follows: the apparent amount when placed on a plate was measured (for reference, measure the specific capacity in a frozen state → measure 100 cc of cooked rice in a measuring cylinder and measure the weight). The texture was evaluated by evaluating the difference in texture based on freshly cooked rice cooked with the same recipe.
[0027]
[Table 1]

As shown in FIG. 3, the frozen cooked rice of the example has a large specific volume when placed on the plate 5 because the space S exists between the double-grained cooked rice B. For this reason, at the time of microwave thawing, there is a sense of volume and good air permeability, so that water vapor does not stay in the cooked rice, and each double-grained cooked rice B is also small, so that it is evenly heated and has no sticky feeling, and is cooked freshly. The same texture as that of rice was obtained.
[0028]
【The invention's effect】
As described above, the method for producing frozen cooked rice and the frozen cooked rice of the present invention have the same texture as freshly cooked while being heated evenly, while having a voluminous feel when placed on a plate during microwave thawing. . In addition, since rice with an appropriate number of grains can be stably obtained, there is little unevenness in the product, and the product can be manufactured on a mass production line, so that high productivity can be maintained. Furthermore, since the freezing equipment does not need to have a stirring function, the freezer can be easily cleaned.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of an apparatus for producing a double-grained cooked rice according to the present invention. FIG. 2 is a view taken in the direction of arrows II-II in FIG. 1. FIG. Schematic diagram of the folded state [Explanation of reference numerals]
1 ... rice feeding cylinder, 2 ... rice feeding conveyor, 3 ... loosening net, 4 ... cooling conveyor, 5 ... plate, B ... double grain bulk rice, S ... space

Claims (5)

The cooked rice is thrown into a rice feeding cylinder having a self-weight dropping function, and the rice is continuously supplied to a loosening net arranged close to an outlet of the rice feeding cylinder, and either one of the rice feeding cylinder and the loosening net or While operating both of them in the direction crossing the supply direction of the cooked rice, the cooked rice passing through the mesh of the unraveling net is sheared by the unraveling net to form a multi-grain mass, and the formed rice is frozen. A method for producing frozen cooked rice. The method for producing frozen cooked rice according to claim 1, wherein the unraveling net has a wire diameter of 1.5 to 4 mm and a mesh size of 10 to 30 mm. The frozen cooked rice obtained by the method according to claim 1, wherein 3 to 10 uncrushed grains are formed per single multi-grain block. 2. The frozen cooked rice obtained by the method of claim 1, wherein the weight of the double-grained block is 0.2 to 0.5 g. 2. Frozen cooked rice, wherein the double-grained cooked rice obtained by the method of claim 1 is mixed with a single-grained cooked rice in a weight ratio of 50% or more.

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