JP2002218924A - Method for treating polished rice with ozone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treating polished rice with ozone, by which the taste of the polished rice can be improved without damaging environments on the treatment of the ozone. SOLUTION: This method for treating the polished rice with the ozone, comprising fluidizing the polished rice and then bringing the fluidized polished rice into contact with the ozone to subject the rice to the adsorption treatment, is characterized in that Q/P is 0.05 to 0.25 mg/kg, wherein P kg/s is the quantity of the fluidized polished rice; Q mg/s is the quantity of the supplied ozone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for ozone treatment of polished rice.

[0002]

2. Description of the Related Art It is known that ozone is brought into contact with old rice in order to remove a smell (old rice smell) peculiar to old rice. The contact with ozone is performed by blowing ozone gas into the outlet of a rice mill or a color sorter in the rice milling process, or by blowing ozone gas into a hopper of a bagging machine.

[0003]

However, since the polished rice easily absorbs ozone, the odor of old rice is removed by the absorption of ozone, but the odor of ozone remains in the polished rice. In the past, in the past, when bringing old rice into contact with ozone, it was not rationally known how much ozone should be contacted and how. In addition, in the conventional method as described above, since the supply part of ozone to the polished rice is not sealed, a part of the ozone blown into the part leaks out of the apparatus, and the polished rice and ozone In addition to the fact that it is not possible to carry out the reaction quantitatively at the optimal amount, the leaked ozone contaminates the working environment and corrodes peripheral equipment such as rice mills, identification and sorting machines, bucket elevators, etc. I was

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and reacts polished rice with ozone under an optimum condition to remove old rice odor from old rice. Needless to say, to provide an ozone treatment method for polished rice that improves the taste of polished rice having no old rice odor and that does not harm the environment due to excessive ozone during processing. It is intended for.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method of adsorbing rice by flowing milled rice and supplying and contacting ozone to the milled rice in flow. Is set to P kg / s, and the ozone supply amount is set to Q mg / s, which is achieved by Q / P = 0.05 to 0.25 mg / kg.

[0006] In order to improve the taste of the polished rice or remove the smell of old rice, it is extremely important that the value of Q / P is within the above range. The optimal value within this range varies depending on the type of rice and the condition of the whitening, but in the first place the taste depends on regional differences and individual differences, so the optimum amount is generally specified. Although it is not possible, in any case, if the value is within the range, the improvement is made even if the degree and the content are different. It goes without saying that if it is below this range, the effect of removing old rice odor and the improvement of taste in other senses will be insufficient, but if it is above this range, there will be a problem of adding an odor that induces aversion to ozone. Become like

[0007] In the present invention, the flow of the milled rice and the supply of ozone are preferably carried out in a substantially closed space at least in the ozone reaction zone. Here, the substantially closed space is provided by the ozone reaction zone, which has an opening for supplying and discharging the polished rice,
This is because it cannot be said that there is no air circulation with the outside. In the open state, even if ozone is supplied only at the optimal value, a part of it is dispersed around and the amount of ozone that reacts with the polished rice is insufficient, or slightly higher than the optimal value. When ozone is supplied, more ozone is radiated to the surroundings, causing problems such as harm to the environment, but by substantially closing the space,
This is prevented beforehand, and the optimal amount of ozone reacts stably with the polished rice.

The reason why the milled rice is made to flow is that the contacting force between the grains of the milled rice is weakened in the flowing state compared to the stationary state, and the milled rice becomes coarse and the contact with the ozone is facilitated. is there. Also, in relation to continuous processing, processing in a fluid state is more rational.

[0009] The flow of the above polished rice can be carried out, for example, on a slope. At this time, it is preferable that the polished rice flows down in a uniform thickness layer on the slope.

[0010] The slope may be a conical surface, for example, a conical surface. At that time, it is desirable that the supply of ozone is performed by blowing ozone toward the conical surface from an annular slit concentric with the conical surface. By doing so, the ozone comes into uniform contact with the flowing down milled rice.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 shows an overall view of an apparatus suitable for this embodiment.

The reactor (B) for performing the ozone reaction treatment is connected to a hopper (A) at an upper part and to a feeder tray (C) at a lower part. The feeder tray (C) is connected to the electromagnetic vibrator (D) at the lower part. As is well known, the processing speed (flow amount) of the polished rice can be adjusted by changing the discharge amount of the polished rice from the feeder tray by the electromagnetic vibrator (D). An ozone generator (E) is provided below the frame (G) of the apparatus, and the ozone gas generated by the ozone generator (E) is sent to the reactor (B) via the pipe (F). Supplied. The hopper (A), feeder tray (C), electromagnetic vibrator (D), and ozone generator (E) are assembled on a frame (G).

Next, FIG. 1 shows the details of the reactor (B).
In FIG. 1, a short pipe (1) is, for example, a 50A PVC pipe, and the upper part is connected to a hopper. For the reactor (B), for example, a reduced-diameter socket tube having a nominal diameter of 100 × 75 is used, and the lower portion is opened above the feeder tray (C). In the upper lid (2) of the reactor (B), for example, 100
A hole for inserting the short pipe (1) was formed in a PVC cylinder corresponding to the PVC pipe of A, and an annular groove (3) was formed on the inner surface of the hole, and was penetrated to communicate with the groove. An ozone gas introduction pipe (4) (a PVC pipe having an outer diameter of 8 mm) is inserted into the side hole. The inner diameter of the lower opening of the upper lid (2) is slightly larger than the inner diameter of the upper opening, for example, about 2 mm, and when the short pipe (1) is inserted into the upper lid (2), the outer diameter of the short pipe (1) and the lower opening of the upper lid. An annular slit (c) having a width of 1 mm is formed between the slit (c) and the inner diameter. Thus, the ozone gas blown from the ozone gas introduction pipe (4) is blown downward from the annular slit (c).

A conical block (5) is provided below the short pipe (1). This conical block (5)
For example, it is formed by cutting a PVC cylinder, and is hung by hanging metal fittings (6) attached to a plurality of circumferential locations at the lower edge of the upper lid (2). Conical block (5)
Is preferably 40 degrees or more. If it is smaller than this, the polished rice does not roll when flowing down the surface of the conical block. Rolling is preferable for more uniform ozone treatment.

It is desirable that the gap (a) is set to be 10 to 15 mm. If the gap (a) is larger than this, the thickness of the layer when the polished rice flows down the surface of the conical block (5) becomes large, making it difficult to sufficiently and uniformly contact the ozone. At this time, it is also important that the annular area (flowing cross-sectional area) formed by the gap (b) does not become smaller than the annular area (flowing cross-sectional area) formed by the gap (a). Otherwise, the movement amount of the polished rice is regulated by the gap (b), and the layer thickness of the polished rice falling on the surface of the conical block cannot be set to 10 to 15 mm.

In the apparatus of this embodiment, the polished rice is subjected to ozone treatment in the following manner.

According to the present invention, the milled rice moved downward from the hopper (A) spreads on the conical upper surface of the conical block (5) in the reactor (B) to form a thin layer having a thickness of 10 to 15 mm, and It flows downward while rolling on the conical surface. Ozone is blown downward from the annular slit (c) into the reactor (B), and the polished rice uniformly contacts the ozone during the tumbling flow.

Since the reactor (B) is substantially sealed, the amount of ozone supplied to the flowing polished rice is adjusted to an optimum amount so that ozone is not insufficient or excessive. In addition, it becomes possible to adsorb a predetermined optimal amount of ozone to the polished rice, thereby preventing leakage of ozone gas out of the reactor.

The optimum amount of ozone is in the range of Q / P = 0.05 to 0.25 mg / kg when the flow rate of milled rice is P kg / s and the supply amount of ozone gas is Q mg / s. Is the value of

This value is calculated by filling a cylindrical column having a diameter of 20 mm with 50 g of polished rice, feeding in ozone gas from below, and calculating the amount of addition from the difference between the ozone concentration of the supply gas and the exhaust gas and the gas addition time. Then, make various amounts of polished rice, and conduct a taste test on the cooked rice obtained by cooking these,
It was determined from the results.

More specifically, 20 kinds of polished rice with different brands and harvesting years are randomly selected, and a sample is prepared by adding ozone in seven different amounts to these, and there is also a sample in which ozone is not added. Eight kinds of samples, including rice, were cooked and taste tested, and the results were obtained depending on the difference from those without addition.

The test was performed on 20 types of polished rice by 20 panelists for 8 samples as described above, but the test results are average values, and not all persons evaluated the same. Needless to say.
Also, due to the sample size, the dates of the tests are not the same. Some of the results of the panel test are shown in Table 1. However, since the test method and its meaning are generally well known, the description thereof is omitted here.

For the total evaluation value of the panel test, the test results are plotted by plotting the point difference between the sample to which ozone gas is not added and the sample to which ozone gas is added on the vertical axis and the amount of ozone gas added on the horizontal axis. A graph as shown in FIG. 3 was obtained.

In the overall evaluation value, if there is no significant difference below 1 point, the ozone addition amount is 0.05 to 0.25 mg /
It is judged that there is a superior difference around kg. Thus, in the present invention, this range is set as the optimum amount of ozone addition. In other words, the meaning of the optimum amount of the present invention means that, in relation to the purpose of ozone addition and the rice to be added, the optimum amount of ozone to be obtained is within the range of the optimum amount of the present invention, It is determined appropriately within this range. In addition, when the amount is small, the effect is only small, but when the amount is excessive, it is obvious that the effect is adverse, and it is needless to say that this is necessary.

Table 1 shows an example of a taste test of cooked rice to which the optimum amount of ozone was added according to the above-described procedure and to which ozone was added.

[0027]

[Table 1] Here, Table 1 will be described.

Table 1 shows the results of a panel test generally known as a taste test of cooked rice.

A1 and A2 are made of the same old rice as the raw material,
For rice cooked without ozone treatment, A2
Is a test conducted on rice cooked and cooked by adding 0.2 mg / kg of ozone according to the present invention. A
Comparing 1 with A2, it was found that the ozone treatment removed much of the bad scent (in this case, especially the smell called old rice odor), and also included other evaluation items for taste, namely, the appearance of cooked rice, It can be seen that the gloss, the taste, etc. were also improved, and the overall evaluation was improved by 5 points.

B1 and B2 are made of the same new rice as raw material,
For rice cooked without ozone treatment, and B2
Is a test conducted on rice cooked and treated by adding 0.1 mg / kg of ozone according to the present invention. Comparing B1 and B2, the ozone treatment reduced the fresh rice aroma due to the deodorizing effect of ozone, but improved in other items and improved the overall evaluation by 2 points. I understand.

In the case of A2, the supply amount of ozone is set mainly for the purpose of removing old rice odor, and in the case of B2, the other taste evaluation items are improved while leaving the fragrance of new rice. , The supply amount of ozone is not the same.

[0032]

As described above, the flow rate of milled rice is Pkg,
When the supply amount of ozone is Q mg / s, Q / P = 0.0
The polished rice is treated with ozone in the optimum value range of 5 to 0.25 mg / kg, so that the amount of ozone is not excessive or insufficient, so that the taste of polished rice is improved and the amount of ozone radiated to the surroundings is extremely small. This has the effect of not harming. At this time, if the ozone reaction treatment is performed in a reactor substantially closed at least in the reaction zone, the effects on both the taste of the polished rice and the emission of ozone are further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a reactor of an apparatus according to an embodiment of the present invention.

FIG. 2 is an overall view of a milled rice ozone treatment apparatus as an embodiment of the present invention.

FIG. 3 is a graph showing the results of a taste test of polished rice subjected to ozone treatment according to the present invention in relation to the amount of ozone added.

[Explanation of symbols]

 5 Conical block (slope, conical surface) c Annular slit

Claims (6)

[Claims] 1. A method for adsorbing rice by flowing milled rice and supplying and contacting ozone to the milled rice in flow.
The flow rate of milled rice is Pkg / s, and the ozone supply rate is Qmg /
The ozone treatment method for polished rice, wherein Q / P is 0.05 to 0.25 mg / kg, where s. 2. The ozone treatment method for polished rice according to claim 1, wherein the flow of the polished rice and the supply of ozone are performed in a substantially closed space at least in an ozone reaction zone. 3. The method according to claim 1, wherein the flow of the polished rice is performed on a slope. 4. The ozone treatment method for polished rice according to claim 1, wherein the flow of the polished rice is performed in a layer having a uniform thickness on the slope. 5. The slope according to claim 3, wherein the slope is a conical surface.
Or the ozone treatment method of the polished rice according to claim 4. 6. The ozone treatment method for polished rice according to claim 5, wherein ozone is supplied by blowing ozone toward the conical surface from an annular slit concentric with the conical surface.