JPS62102835A - Germ remaining rice refining method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This research relates to a rice polishing method for polishing rice so that the germ and root parts remain.

[Problems to be solved by the prior art and the invention] The structure of rice grains can be roughly divided into the following: Figure 1.

The inner endosperm (1), the outer skin layer (2), and the germ (3)
). Rice polishing is the removal of the bran layer (2), but depending on whether or not the germ remains, the rice after polishing is divided into 2 layers.
Divided into species. That is, there are two types of rice: germinated rice, in which the germ remains in most of the rice grains, and normally polished rice, in which the germ has been removed from most of the rice grains. In the case of regular rice grains, the germ is easily separated from the rice grain itself. Although it is difficult for certain rice varieties, such as Kiyo-Nishiki, to break away, in general, it is easy to break away, and Nipponbare is a typical example. For this reason, it is prohibited to apply pressure when feeding rice with germ.
A grinding type rice mill is usually used to mill germ rice.

This grinding type rice polishing machine uses a grinder such as diamond sand,
It uses low pressure to remove only the bran layer on the surface of the rice grains. Figure 2 shows germ powder with almost completely remaining germ. It is stipulated that polished rice in which 80% or more of such grains have residual germ is called germinated rice. When calculating the germ survival rate, a rice grain with almost completely remaining germ is counted as 1, as shown in Figure 2. In Figure 3, about half of the germ has been removed, but the rest remains attached to the main body of the rice grain.

This is also recognized as germ flour. However, in the case of the one shown in Fig. 3, the germ survival rate is calculated as 05. Although this type of germ rice is nutritionally superior, it is generally disliked because it tastes bad, has an unpleasant yellow germ, and has a strong taste. On the other hand, conventionally polished rice is generally milled using a friction rice mill. In normal polished rice, the germ survival rate is less than 20% and still less than 15%. Normally, the germ of refined grains is completely removed, as shown in Figure 4.

The depth of this hole reaches about 1/4 to 1/3 of the grain of rice. The reason why such a deep hole was created is that although the germ served as a lid for the endosperm, the extremely fragile tissue in the center of the endosperm was eroded during milling because the germ was removed. It is assumed that it became cave-like. As a result, the running rate during rice milling becomes poor, and bran powder and the like enters the holes and remains unremoved, making it impossible to improve the accuracy of bran removal.

That is, in the usual rice milling method, the germ is completely separated from the rice grain body, including the colon, and is then eroded to form a deep hole. Since the rice grains and other particles are trapped in this area, no matter how much you polish the surface of the rice grains, you cannot remove this bran powder.
Washing the rice before cooking is essential.

As mentioned above, there are two conventional rice polishing methods: the grinding method and the friction method, but the grinding method is inefficient, so it is only used in some cases, such as for germ rice and sake-brewing rice. , the friction type is generally used.

However, some rice milling machines use a grinding method for the first stage of polishing.
A combination type that uses a friction type in the latter stage has also been developed,
This is an extremely rare case. In these two methods, the grinding type grinds by the rotation of the grinder, so the circumferential speed of the grinder becomes an issue, while the friction type removes the grain by particle friction, so the angular speed of the polishing roll becomes an issue. The angular velocity of a typical friction type rice mill is 500 to 800 lPM, and even the faster ones are less than lo o o & PM. In the friction type, the circumferential speed is not the same, but in reality, this circumferential speed is also slow, at most about 350 m/min. However, when using a rice milling machine with such a slow circumferential speed, the germ survival rate is high during milling with a low finish milling level, but if you try to increase the milling level, you will inevitably have to increase the milling pressure.
As a result, the germ survival rate decreases to the end of the chain, and when finished to a commercially available self-scoring angle of 40° (kerato whiteness meter), almost no germ remains, and the germ is completely removed from the root part.
A cave-like hole is formed in the ruins.

In view of the above-mentioned points, the present invention aims to improve the yield and bran removal precision by using a friction method to remove the germ leaving the root part, and improves the taste and nutritional value of polished rice. The purpose of the present invention is to provide a method of polishing rice that simultaneously increases

[Failure to solve the problem]

The technical means of the rice milling method of the present invention is that in the rice milling method in which milling rolls are rotated in a milling room and milled while blowing air into the milling room, the number of rotations of the milling rolls is set to 100 OR.
The objective is to increase the amount of water to a level above PM and to add water in an amount close to the upper limit of the range in which cracks do not occur.

In the present invention, water may be added from the time of brown rice, but it is preferable to add water after milling has progressed to a certain extent from the viewpoint of exfoliating other bran layers. The rice milling method is a friction type, and the milling rolls are rotated at high speed. The rotation speed of the polishing roll in a conventional friction rice mill is usually 500 to 800 K.
Even the fastest PM is less than lo o o KPM. In fact, it was impossible to increase the speed any higher than this due to negative effects such as broken rice and caking. In the present invention, this is 100
0 and PM or more. The smaller the diameter of the polishing roll, the better the speed. This kind of high-speed polishing was made possible by the interaction with water.As a result of adding water and high-speed polishing, the rice bran layer, which had absorbed water and softened, became appropriately viscous due to the sufficient pine surge action between grains, and the rice bran was polished. This is because when the layers are removed, they peel off little by little. Further, the amount of water added in the present invention is preferably as large as possible without causing any adverse effects. That is, if the amount of water added is increased, the surface of the polished rice will first have the adverse effect of cracking, so it is preferable to set the value to the upper limit or close to the upper limit of the range in which such cracks do not occur. However, the optimal value for the amount of water added varies greatly depending on the conditions of the rice to be processed, such as the rice variety and harvesting time, and the milling conditions, such as the rotation speed of the milling roll, so it is generally not possible to determine the range of the appropriate amount of water to be added. However, it is generally about 0.4 to 1.2% by weight. Since rice is milled at high speed in the present invention, it is possible to increase the amount of water added without causing any adverse effects than in the case of conventional low speed milling. However, in the final stage of pumping, no water is added, only a jet of air is used. Adding water at the final stage causes adverse effects such as cracking and broken rice. Further, the residual rate of germ roots can be adjusted by changing the timing of water addition.

In reality, this is done based on the strength of the pounding in the previous stage. That is, if you want to increase the retention rate, reduce the amount of pre-milling, and if you want to lower the residue rate, increase the amount of pre-milling to remove the germ to a certain extent, and then mill it using the method of the present invention. .

[Effect]

In the rice polishing method of the present invention, since water is added, the germ absorbs water and becomes soft. The germ has very good water absorption, and when added to water, it absorbs water in a short time and becomes moist and soft. In addition, in the present invention, since the whitening roll rotates at high speed, the rice grains receive sufficient pine surge action between the grains, and together with the hydration action, the germ is softened appropriately. Since the germ is subjected to high-speed milling in this state, the germ is not peeled off as a whole, but gradually peeled off in layers from the surface. The reason why this peeling phenomenon occurs is that in addition to the softening described above, the polishing roll rotates at high speed, so the frictional force that the rice grains receive per roll rotation is smaller than in the conventional case. Conceivable. In this way, the germ is gradually peeled off in layers from the surface, but since the final root is located deep inside,
It is not affected by the ejaculation effect and remains as it is. Also, as a result of the germ roots remaining, M in the center of the endosperm! Destruction and erosion of the fragile parts of the L weave are eliminated, and a decrease in yield can be prevented. Moreover, since no cave-like holes are formed, bran powder does not accumulate, and the accuracy of bran removal is improved.

Furthermore, since the polished rice according to the present invention retains a portion of the germ, it has higher nutritional value than ordinary polished rice.

In addition, since the residual roots of the germ are located deep in the area where the germ has been peeled off, the presence of the germ roots is not noticeable from the appearance after cooking the rice. Furthermore, the surface layer of the germ has a strong taste and is often disliked by consumers, but the root portion of the germ has a unique taste and aroma that is different from the taste of the surface layer, making it delicious and appealing to consumers. It is also preferred by

〔Example〕

The results of practical tests using the rice polishing method of the present invention are as follows.

Rice polishing machine used: Toyo rice polishing machine CN3-30 type (Note)
In the test, the rice was passed through this rice mill twice, and water was added at the 24th time.

Test rice: Nipponbare 1st prize, produced in Wakayama in 1981 (Note) Nipponbare is a rice whose germ is relatively easy to lose its roots.

Brown rice moisture (measured value) 714.8% Amount of water added: In each test, it was set to the value immediately before cracking (upper 1 Nozosu or a value close to the upper limit).

Polishing degree - In each test, the polishing conditions were adjusted so that the whiteness was 40' (kerato whiteness meter).

The results of the test conducted by changing the number of rotations of the polishing roll are shown in Table -■. Moreover, FIG. 5 shows a cross section of a rice grain with residual germ roots (5).

Table 1: Test results with added water For comparison with the rice milling test with added water, Table 2 shows the results of tests conducted without adding water.

Note that the other test conditions were the same as in the case of f+il Table-1.

Table 2 Test results without adding water In the test shown in Table 2, the number of rotations of the whitening roll was increased to 1.
When the amount exceeded 1,000 liters of PM, the rice milling machine became overloaded and became unable to mill rice.

From the above test results, it can be seen that when the number of oral traditions of refined rolls in a water-added state is set to 1 OOORPM or more, especially 1 106 RP, the germ root residual rate increases significantly. Also, under these conditions, good results were obtained in terms of rice milling yield, washed rice contamination level, and taste sensation.

Effects of the Invention] According to the rice polishing method of the present invention, rice can be polished while leaving the root part of the germ in the rice grain after milling. As a result, the nutritional value of the slightly white rice increases and its taste improves. In addition, since only the root portion of the germ remains, the presence of the germ is not visually noticeable and is not disliked by consumers. Furthermore, as the germ roots remain, erosion of the central part of the endosperm does not occur, which prevents a drop in rice milling yield.In addition, grain flour does not stay in the holes of the eroded area as in the past.
It is possible to increase the degree of bran removal.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of brown rice, Figure 2 is a cross-sectional view of almost complete germ flour, and Figure 3 is a cross-sectional view of germ flour with part of the germ exfoliated.
FIG. 4 is a cross-sectional view of normal milled grains, and FIG. 5 is a cross-sectional view of germ root residual grains obtained by the rice polishing method of the present invention. (1)...Endosperm, (2)...Upward, (3)...Embrium, (4)...Hole, (5)...Embryo root Fig. 5 Fig. 2 Fig. 1 Figure 4 (Figure 3 Procedural Amendments) November 29, 1985 Director-General of the Patent Office Kadobe Fuyu 1. Indication of the Case 1985 Special Application No. 241813 21 Name of Invention Germ-like Remaining Rice polishing method 6, relationship with the case of the person making the amendment Patent applicant address: 7-2-8 Juban-cho, Wakayama City, Wakayama Prefecture
Keiji Sasaga, Representative of the Miscellaneous Goods Technology Research Institute, 8, Details of the Agent, 8, The contents of the amendment (1), and the scope of the claims are revised as shown in the attached document. (2), "Can be done" in the fourth line from the bottom of the second page of the specification is corrected to "add". (3), ``Rice is confusing'' on page 3, line 11 of the same book is corrected to ``When the rice is cooked, the surface of the rice grains becomes dark and it has a bad taste.'' (4), ``About r350m/min'' on page 5, line 9 of the same book is corrected to ``About r350m/min or less''. (5) In the 11th line of page 1 of the same book, ``the force of pounding must be increased, and this result'' is deleted. (6), "Rice polishing method" on page 6, line 6 of the same book is corrected to "friction rice polishing method." (7) In the fourth line from the bottom of the same page of the same book, ``broken rice and caking'' is corrected to ``fever.'' (8), in the second line of page 9 of the same book, the phrase ``exfoliation effect'' is corrected to ``strong exfoliation effect.'' Claims: In a friction-type rice milling method in which milling rolls are rotated in a milling room and milled while blowing air into the milling room, the number of rotations of the milling rolls is set to 11,000 KP or more, and the number of rotations is set to a range that does not cause cracks. A germ root residual rice milling method characterized by adding water at or near the upper limit.

Claims (1)

[Claims] In a rice milling method in which milling rolls are rotated in a milling room and milled while blowing air into the milling room, the number of rotations of the milling rolls is set to 1000 RPM or more, and the amount is at or near the upper limit of the range in which no cracks occur. A method for polishing rice with germ root residue, characterized by adding water.