JP2000041599A - Production of quickly cookable rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain a quickly cookable rice having an eating quality comparable to that of normal rice for cooking without degrading the commercial value by steaming soaked rice with hot steam passed through a ceramic ball layer and quickly cooling the steamed rice. SOLUTION: Soaked rice is steamed with hot steam passed through a ceramic ball layer 5 and the steamed rice is sucked with air in open atmosphere to cool the rice to 0-40 deg.C in 5-90 sec to obtain the objective quickly cookable rice. Preferably, soaked rice is put into an inner space 3 of an inclined nearly cylindrical steamer 1 having a rice-feeding port 2 at the top and a closeable discharging hole 9 at the bottom and steamed by ejecting hot steam from prescribed parts distributed over the whole area of the inner space 3 of the steamer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing fast-cooked rice.

[0002]

2. Description of the Related Art Pretreatment such as washing and immersion in water for making rice and rice is not required, and the rice is cooked faster than the time required for normal rice or steaming (steaming is also possible). Fast-cooked rice is known as a processed rice that can be cooked, and in recent years the demand has been growing because of such simple cooking. As a conventional method for producing fast-cooked rice, for example, as described in JP-A-1-304856, steamed immersion-treated rice is treated with live steam, and then rapidly cooled to about 25 ° C. by vacuum cooling. Aged for 2 days, loosened into single grains, packed in a bag, and as described in JP-A-7-31540, immersed rice is steamed with live steam using a steamer equipped with a fixed-quantity feeder. A method is known in which a fixed amount of steamed rice is put in a bag, rapidly cooled and sealed in a vacuum cooling packaging device, then aged for 1 to 2 days, and then loosened to form a single grain.

However, the above-mentioned conventional manufacturing method is
All of them require an aging process for 1 to 2 days, and have a problem in production efficiency. It is also conceivable to loosen the ripening step without performing the ripening step, but the state of the cooked rice before the ripening step is because the rice grain surface is wet and sticky because of steaming treatment with live steam, and the rice grains are easily bound together Condition. In addition, due to the forced discharge by the quantitative feeder and the subsequent instantaneous cooling by vacuum cooling, the sticky rice grains were more firmly bound together to form a lump. For this reason, it is difficult to break down the cooked rice before the ripening process into single grains easily, and even if the rice is loosened, the resulting fast-cooked rice contains a large amount of broken rice derived from the loosening process and tends to degrade its commercial value Was in Furthermore, in the above-mentioned conventional method, it is hard to say that the fast-cooked rice obtained because of cooling in a vacuum state has the same taste as cooked rice when cooked. Was something.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing fast-cooked rice efficiently without deteriorating its commercial value, and at the same time, the taste when cooked is the same as that of ordinary cooked rice. It is an object of the present invention to provide a method for producing fast-cooked rice having a good taste.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, completed the present invention. That is, the present invention relates to (1) a method for producing fast-cooked rice in which immersion-treated rice is steamed by heating steam passed through a ceramic ball layer, and the steamed rice thus obtained is air-opened and rapidly cooled. (2) The immersion-processed rice is accommodated in the bore of a substantially tubular steaming device having a rice supply port at the top and an openable / closable discharge port at the bottom, and being inclined. (1) a method for producing fast-cooked rice, wherein steaming treatment is performed by injecting heated steam from a predetermined location over the entire cavity;
(3) The method for producing fast-cooked rice according to (1) or (2), wherein the steamed rice is transferred onto an air-permeable conveyor, and air is suctioned from below the conveyor to rapidly cool the rice. ) The temperature of the steamed rice is reduced to 0 in 5 to 90 seconds.
(1) to (3) a method of producing fast-cooked rice, wherein the rice is cooled to -40 ° C.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the present invention, all percentages are by weight unless otherwise specified. In the present invention, fast-cooked rice is not required to be washed or soaked in water when making normal cooked rice or rice, and cooks faster than the time required for normal cooking or steaming (also steaming). (Including processed rice). It should be noted that fast-cooked rice obtained by a method of adding water during the cooking process is not included in the fast-cooked rice according to the present invention.

In the present invention, the soaked rice refers to glutinous rice, glutinous rice, and a mixture thereof washed with water, and then subjected to water soaking and draining. The water content of the soaked rice of the present invention thus obtained is as follows:
Usually, it is about 28 to 40%, for example, when the water content is 15%.
% Of glutinous rice, when immersed in water for about 30 minutes to 3 hours, the water content becomes about 28 to 36%, and when glutinous rice having the same water content is used, 1-1 to 1% in water.
When immersed for about 0 hours, the water content becomes about 30 to 40%. The water temperature at the time of water immersion is not particularly limited, but is preferably 50 ° C. or lower, more preferably 40 ° C.
The following water may be used. Perhaps because the starch on the surface of the rice grains elutes when immersion treatment is performed with water having a water temperature higher than 50 ° C., the treated rice obtained by the subsequent steaming treatment has stickiness, and easily becomes single grains in the subsequent loosening step. It is difficult and not preferable.

In the present invention, first, the above-mentioned immersion-treated rice is subjected to a steaming treatment with heated steam passed through a ceramic ball layer. More specifically, the immersion-treated rice is accommodated in a bore of a substantially cylindrical steaming device which has a rice supply port at the top and an openable and closable discharge port at the bottom, and is inclined. Steaming treatment is performed by injecting heated steam that has passed through the ceramic ball layer from a predetermined location over the entire cavity. The steaming treatment conditions may be ordinary treatment conditions, for example, a vapor pressure of 0.2.
It is preferable to perform the steaming treatment at 5 to 1.5 kg / cm ² for ² to 15 minutes. Thereby, the degree of pregelatinization is 80% or more, and the water content is 30 to 4%.
About 4% of steamed rice is obtained.

In the present invention, the ceramic ball layer is
A state in which substantially spherical balls made of ceramic are stacked when viewed from the side. In the present invention, at least two ceramic ball layers are required. If the ceramic ball layer is a single layer, the rice grain surface of the steamed rice is wet and sticky because it contains coarse water vapor fine particles, and it is difficult to easily form a single grain in the subsequent loosening process Not preferred. The size of the ceramic ball used in the present invention is not particularly limited, but has a diameter of 5 to 30 mm.
It is good to use the one of the degree.

The heating steam is steam having a temperature of 100 ° C. or higher produced by a boiler or the like generally used in the industry. In the present invention, when the steam is injected through the ceramic ball layer into the inner cavity of the steaming apparatus. The temperature immediately after the injection is 100-1
Heated steam is used at a temperature of 10C, preferably 100 to 105C. If the temperature of the heating steam is lower than 100 ° C., the surface of the rice grain of the steamed rice is wet and sticky, and it is difficult to easily form a single grain in the subsequent loosening step, which is not preferable. On the other hand, if the temperature is higher than 110 ° C., the surface of the rice grain will be burnt, and the commercial value will be impaired.

In the present invention, the inclined bore of the substantially tubular steaming apparatus is defined as a square tube, a cylinder, or the like provided with a tilt angle of 30 to 80 °, preferably about 45 to 70 °. Refers to the inner cavity of the steaming device having a shape. When the inclination angle is less than 30 °, the steamed rice is not discharged from the discharge opening of the lumen by its own weight, and therefore, it is necessary to provide a separate forced discharge device. On the other hand, if it is larger than 80 °, the rice grains tend to bind together due to the own weight of the steamed rice and form a lump, which is not preferable. The length of the substantially cylindrical lumen may be appropriately selected depending on the time and amount of the steaming treatment, and the thickness of the substantially cylindrical lumen is the shortest distance between the rice grains and the injection hole for injecting the steamed cooking. Should be within 30 cm. If the distance is more than 30 cm, a portion not sufficiently exposed to the heated steam is formed, and uneven steaming may occur, which is not preferable.

Injecting the heating steam from a predetermined location over the entire cylindrical lumen means that an injection hole is provided so that the heating steam can be uniformly injected over the entire lumen.
This refers to steam injection. For example, an injection hole for heating and steaming may be provided on the entire wall surface of the lumen or on a specific wall surface as described in Examples below. As a result, uniform steamed rice without uneven cooking can be obtained.

In the present invention, the steamed rice obtained as described above is then cooled rapidly by suctioning air under open condition. In the present invention, the cooling of the steamed rice by air suction while open is not performed in a closed state as in vacuum cooling, but in a state where air can freely enter and exit, and the surroundings of each grain of the steamed rice are cooled. Means to cool the steamed rice by the flow of air by the suction method of sucking air, preferably, transfer the steamed rice to an air permeable conveyor such as a net conveyor. At the same time, air is sucked from below the conveyor and cooled. When air is sucked from above the conveyor,
In the cooling process, the water evaporated from the steamed rice falls as water drops on the treated rice, and the rice grains in that portion tend to bind together to form a strong mass, which is not preferable.

In the present invention, rapidly cooling the steamed rice means that the temperature of the steamed rice is 0 to 4 within about 90 seconds.
Cooling to 0 ° C, specifically 5 to 9
It is good to cool so that the product temperature may be 0 to 40 ° C. in 0 seconds, preferably 0 to 30 ° C. in 5 to 60 seconds. Such rapid cooling by air suction requires suction at an air volume of at least 20 m ³ / min. This cooling evaporates some of the water in the rice grains. It is about 40%. If the cooling time is longer than 90 seconds or the product temperature is higher than 40 ° C., the rice grains bind to each other to form a solid mass, while the product temperature is 0 ° C.
In the following cases, rice grains freeze and are not preferable. The reason why the cooling time is set to 5 seconds or more is that production on an industrial scale is difficult.

In the present invention, a similar or another conveyor may be provided in front of the conveyor, as long as the quality of the obtained rice is not deteriorated. Further, after cooling the product temperature to be 0 to 40 ° C. by the above-described method, air may be further suctioned in the range of the product temperature or cooled by another method.

The treated rice obtained by the above-mentioned method is then loosened to obtain single-grained rice of the present invention. The fast-cooked rice obtained according to the present invention may be filled and sealed in a bag made of polyethylene or nylon as necessary. The treated rice before or after singulation may be further dried by a conventional method to prepare, for example, fast-cooked rice having a water content of 20% or less.

[0017]

The cooked rice obtained according to the present invention can be easily broken into single grains without any aging process for about one day, and without impairing the commercial value, for any reason. It is not known whether (2) the taste when cooked has the same level of taste as ordinary cooked rice, but as for the above (1), the heating steam produced by a boiler or the like cannot be used. It is said that there are many small droplets of drain (condensed water) generated by heat radiation from piping when air is sent from the boiler, in addition to saturated steam and superheated steam. When used, the surface of the rice grain is wet by the droplets of the drain, and the starch in the rice grain precipitates in the wet portion of the rice grain surface in the process of turning the rice grain into alpha, whereas the rice grain surface has stickiness, The present invention is a boiler It is speculated that by passing the heating steam produced in the above through the ceramic ball layer, the small droplets of the drain are removed from the heating steam, so that it is possible to obtain a steamed rice that is hard to loosen the rice grain surface and is easy to loosen. Is done. In addition, as shown in the explanatory views of the cooling method in FIGS. 3 and 4 described below, in the conventional air blowing method, the flow of air between the rice grains is obstructed, so that cooling unevenness occurs in the cooling process and the rice grains are connected. While it is easy to wear, by using the air suction method of the present invention, air can flow between the rice grains, and it can be cooled evenly,
It is presumed that this is because the rice grains are easily loosened and the rice grains are cooled in an open state without the rice grains being tightened.

Regarding the above (2), in the conventional vacuum cooling, the umami component in the rice grains is also sucked, probably because the vacuum is rapidly sucked so as to be in a state close to the vacuum, whereas the present invention is open-ended. From what is done below, it is speculated that this may not be the case.

Hereinafter, the present invention will be described in more detail with reference to the drawings of one embodiment of the present invention, with reference to the embodiments and test examples. FIG. 1 is a front view for explaining a quick-cooked rice production apparatus embodying the present invention, FIG. 2 is a schematic explanatory view of an air suction portion of a cooling device, and FIG. 3 is an explanatory view of a cooling method using an air suction method of the present invention. FIG. 4 is an explanatory view of a cooling method using a conventional air blowing method.

[0020]

Example 1 After washing polished glutinous rice, it was immersed in clear water at a water temperature of about 25 ° C. for 1.5 hours, and then drained to remove water content of about 32.
% Soaked rice was obtained.

Next, the soaked rice was steamed by the steaming apparatus 1. That is, the immersion-treated rice was continuously supplied from the rice supply port 2 of the steaming apparatus 1 to a rectangular tube-shaped lumen 3 having a length of 130 cm, a width of 60 cm and a thickness of 20 cm and a tilt angle of 60 °. On the other hand, heated steam (a, a,...) Injected from sparge pipes 4 and 4 and passed through a ceramic ball (diameter of about 20 mm) layer 5 composed of 9 to 10 layers is supplied from a steam chamber 6 to a lumen 3.
0.8kg / c vapor pressure through the injection holes (7, 7, ...)
It injected m ^2, and the dipped rice supplied to the lumen 3 to 8 minutes steaming, the steaming rice cut from the discharge port 9 by clipping device 8. In addition, the steaming process at the start is performed by steaming for 8 minutes with the damper 10 located at the discharge port 9 closed, and then using the cutting device 8 so that the steaming process time is 8 minutes while the damper 10 is open. The steamed rice was continuously steamed at a rate of about 1 t / hr while cutting out the rice. The water content of the steamed rice obtained was about 36%, and the degree of pregelatinization was about 95%.

Next, the steamed rice was cooled by the cooling device 11. In other words, the steamed rice is transferred to a net conveyor 12 which is an air-permeable conveyor, and is sucked at a flow rate of about 120 m ³ / min from the intake ducts 13, 13, 13 located below the net conveyor 12. Thus, the air filtered by the air filter 14 is sucked, and the net conveyor 1 is sucked by the sucked air.
2. Cool the cooked rice on top to about 25 ° C in about 30 seconds,
The water content is about 32%. After being conveyed, the net conveyor 12 is washed in the net washing tank 15 and the draining slit 1
Drain at 6 In addition, suction air (b, b, ...)
As shown in FIG. 2, fresh water 18 is separately stored in a water tank 17.
Is transferred to the injection nozzle 20 by the pump 19 and the injection nozzle 2
By injecting fresh water 18 from zero, the atmosphere in the injection chamber 25 can be set to a negative pressure state. In addition, this injection chamber 2
5 communicates with the intake ducts 13, 13, 13, whereby external air is converted into suction air (b, b,...) Via the air filter 14, the net conveyor 12, and the intake duct 13. You.

Next, the rice which has been subjected to the cooling treatment is loosened
In order to make it into one grain, the net conveyor for loosening 22
The cooled rice is transferred and clamped in the gap between the stainless steel mesh plate 23 of about 5 mm disposed below the chilled rice. By cooling the unraveling net conveyor 22, the cooled rice is mashed in the gap and passed through the mesh of the mesh plate 23 to obtain single-grain fast-cooked rice of the present invention. In addition,
In this embodiment, the net conveyor 22 for loosening and the net plate 2
The above-mentioned loosening was performed by setting the minimum gap of No. 3 to about 5 mm.

Obtained fast-cooked rice (raw rice: rice) 5
The same amount of fresh water was added to 00 g, and cooked rice was prepared using a rice cooker (cooking time: about 20 minutes). On the other hand, cooked rice was produced in the same manner using 500 g of the immersion-treated rice obtained in the above-mentioned intermediate step (cooking time: about 30 minutes). As a result, assuming that the time required for the immersion treatment is 1.5 hours, the use of fast-cooked rice shortens the immersion treatment time and the cooked rice time by about 1.7 hours, compared to the case of making cooked rice from polished rice. Can, and
The obtained cooked rice had a similar taste.

Example 2 After washing the polished glutinous rice, it was immersed in clear water at a water temperature of about 25 ° C. for 4 hours, and then drained to obtain a immersion-treated rice having a water content of about 36%. This immersion-treated rice was used to produce a pre-cooked rice of the present invention in the same manner as in Example 1. The steamed rice has a water content of about 40% and a degree of pregelatinization of about 95%.
The water content of the cooled rice was about 36%.

The obtained quick-cooked rice (raw rice: sticky rice) 60
0 g was steamed for 5 minutes, 200 g of clear water was sprinkled and made uniform, and further steamed for 10 minutes to produce steamed rice (steaming time: about 15 minutes). On the other hand, 600 g of the immersion-treated rice obtained in the above-mentioned intermediate step was subjected to steaming for 20 minutes, and 200 g of clear water was sprinkled and made uniform. 40 minutes). As a result, assuming that the time required for the immersion treatment is 4 hours, the use of fast-cooked rice can shorten the immersion treatment time and the steaming time by about 4.4 hours, compared to the production of brown rice from polished glutinous rice. The obtained rice had a similar taste.

[0027]

[Test Example] In Example 1, when the steaming treatment was performed with the heated steam passed through the ceramic ball layer as in Example 1 or not, or the cooling time shown in Table 1 was changed by variously changing the suction air volume. The ease of loosening with a loosening machine and the occurrence of rice breakage in the resulting quick-cooked rice were visually observed.

[0028]

[Table 1]

From Table 1, it was found that those subjected to steaming treatment with heated steam that does not pass through the ceramic ball layer or those having a cooling time of more than 90 seconds were difficult to loosen, and many broken rice were observed. From this, to obtain quick-cooked rice that is relatively easy to loosen and has less broken rice, it is steamed by heating steam that has passed through the ceramic ball layer, and the resulting steamed treated rice is rapidly air-opened and opened. That is, it is understood that cooling is required within 90 seconds. In particular, among the products of the present invention, those having a cooling time of 60 seconds or less were easily loosened and no rupture of rice was observed.

[0030]

As described above, according to the present invention, it is possible to loosen the rice without premature aging for about one day without deteriorating the commercial value. Since it is possible to provide fast-cooked rice that can be manufactured efficiently and has a taste similar to that of ordinary cooked rice when cooked, further productivity and demand for fast-cooked rice are expected. .

[0031]

[Brief description of the drawings]

FIG. 1 is a front view for explaining a fast-cooked rice production apparatus.

FIG. 2 is a schematic explanatory view of an air suction portion of the cooling device.

FIG. 3 is an explanatory diagram of a cooling system using an air suction system according to the present invention.

FIG. 4 is an explanatory diagram of a cooling method using a conventional air blowing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steaming apparatus 2 Rice supply port 3 Lumen 4 Sparge pipe 5 Ceramic ball layer 6 Steam room 7 Injection hole 8 Cutout device 9 Outlet 10 Damper 11 Cooling device 12 Net conveyor 13 Intake duct 14 Air filtration filter 15 Net washing tank 16 Drain slit 17 water tank 18 fresh water 19 pump 20 injection nozzle 21 loosening machine 22 net conveyor for loosening 23 net plate 24 rice grains 25 spraying chamber a heated steam b suction air c blowing air

Claims (4)

[Claims] 1. Cooked rice obtained by steaming immersion-treated rice with heated steam passed through a ceramic ball layer, and rapidly cooling the obtained steamed rice by sucking air in an open state. Production method. 2. An immersion-processed rice is accommodated in a bore of a substantially tubular steaming device having a rice supply port at an upper part and a discharge port which can be freely opened and closed at a bottom part, and the immersion-treated rice is accommodated in the steamer. 2. The method for producing fast-cooked rice according to claim 1, wherein the steaming treatment is performed by injecting heated steam from a predetermined location over the entire inner cavity. 3. The method for producing fast-cooked rice according to claim 1, wherein the steamed rice is transferred onto an air-permeable conveyor, and the air is suctioned from below the conveyor to rapidly cool the rice. 4. The temperature of the steamed rice is reduced from 0 to 4 in 5 to 90 seconds.
The method for producing fast-cooked rice according to any one of claims 1 to 3, wherein the rice is cooled to 0 ° C.