JP2936136B2 - Water absorption method for pigmented rice brown rice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a coloring method that can efficiently color cooked rice with a safe pigment derived from the rice itself, which is a foodstuff, and has a small unpleasant texture even when mixed and cooked with ordinary polished rice. Boiled rice can be obtained, which makes it possible to produce high-value-added cooked rice foods, which contributes to the revitalization of the food industry and the development of new uses for rice, which can also contribute to expanding demand for rice. Concerning the chemical method. In addition,
The facility / apparatus for manufacturing the product of the present invention can be handled by facilities / apparatus (refrigerator / freeze dryer) generally used in the food industry.

[0002]

2. Description of the Related Art Pigments of pigmented rice such as purple and black rice are unevenly distributed in a "bran layer". Therefore, the use of pigment is also a method of using brown rice or rice bran. Conventionally, when pigmented rice is used as a food coloring agent such as colored rice in a granular form, A method in which colored rice is produced by adding a small amount of pigmented rice brown rice to regular rice and cooking and steaming. . A method in which colored rice is produced by using the entire amount of pigmented rice brown rice, except for part of the bran, such as two-minute milling. . A method of transferring brown pigment to endosperm tissue by steaming brown rice, drying the brown rice, milling the brown rice, and turning it into colored rice (parboiled rice).

However, these conventional techniques have the following disadvantages. the above. In the case of brown rice, it is difficult to cook rice because it is difficult to absorb water during flooding and cooking. is there. Also, although the whole amount of brown rice pigment is used, the elution of the pigment is somewhat slow and the coloring efficiency of white rice is poor. . In the case of (1), only a part of the pigment can be used because it is used almost in a polished state. In addition, the color tone of the outer layer of the bran is lost due to the milling, so that the color tone is slightly inferior. . In this case, the cooked rice has good physical properties because it is polished rice. However, the steaming treatment of brown rice causes a loss of pigment decomposition and a reduction in the vividness of the color tone.

[0004]

Since brown rice has poor water absorbency, when cooked in the same manner as polished rice, brown rice has disadvantages such as a harder texture and less stickiness than polished rice. In order to eliminate the difference in the physical properties of cooked rice and rice, it is necessary to make brown rice easily absorb water. However, at this time, it is necessary that there is no loss of the target dye and no change in color tone, and the coloring efficiency must not be impaired. Furthermore, in order to maintain the safety image of "safe food-derived pigments", it is necessary to avoid using or contacting materials such as solvents that are regulated by the Food Sanitation Law in the treatment process.

The present invention has been made to solve these problems. As a method, pigmented brown rice is swelled by absorbing water at a low temperature without alteration, germination and loss of pigment. This is freeze-dried to make multi-hole expanded pulverized rice, which is excellent in coloring efficiency and makes it possible to obtain pigmented rice brown rice with less discomfort even when mixed and cooked with polished rice. Has not been developed so far.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for absorbing colored brown rice or red rice containing a useful pigment in a bran layer of rice grains into colored rice and processed foods thereof. In the method for absorbing pigmented rice brown rice used in the method of absorbing water, when the above pigmented rice brown rice is used as a coloring agent or colored rice for cooked rice, there is little discomfort in terms of texture and loss of useful pigments from ordinary rice cooked rice. When producing brown rice with high water absorbency and extremely little change in color tone, brown rice with pigmented rice is treated at a low temperature of 5 ° C. without brown rice alteration, germination and loss of pigment.
Water absorption for 3 days to swell by saturating the amount of water absorption and freeze-drying it to give a multi-porous expanded brown rice, whereby water absorption at the time of infiltration of rice grains is quick and excellent in coloring efficiency, and mixed rice with rice polishing It is characterized by obtaining easily absorbable pigmented rice brown rice with little discomfort.

[0007]

According to the above-mentioned method, the method for water absorption of pigmented rice brown rice according to the present invention comprises the steps of: absorbing brown rice at a low temperature of 5 ° C. for 2 to 3 days so as to saturate the amount of water absorbed; Absorbs water and swells. This is freeze-dried and dried while maintaining the swollen form, and the bran layer and endosperm tissue become polyporous. Since the tissue is multi-porous, the brown rice easily absorbs water when immersed and cooked. For this reason, the physical properties of cooked rice are improved, the dissolution of the pigment is facilitated, and the colorability is improved.

[0008] Since the process of producing the highly water-absorbent brown rice is all performed at a low temperature of 5 ° C, it is not affected by the thermal decomposition of the pigment or the action of the pigment-decomposing factor such as an enzyme possessed by itself, and the reduction or discoloration of the pigment is prevented. Absent. Also, since no chemicals are added, the safety image is not impaired.

[0009]

Embodiments of the present invention will be specifically described below with reference to the tables. The derivation of the present invention is based on the following grounds. 1) Brown rice and polished rice were immersed in water at 5 ° C, and as a result of examining the immersion time and water absorption, brown rice absorbed water slower than polished rice.
The water content was small after a short soak. But 2-3
When water was absorbed for a day, the water absorption reached saturation, and the water content between the tested cereals was almost equal. From this result, it is the grounds that when rice is cooked by the short-time immersion treatment, there is a significant difference in the physical properties of the brown rice and the polished rice.

[0010] Brown black rice, which is obtained by immersing brown rice in water at 5 ° C and absorbing water until saturation, and then freeze-drying, has remarkably improved water absorption (see Table 1).

[Table 1] Table 1 shows the results of immersing brown rice and polished rice in water at 5 ° C. and examining the immersion time and water absorption. Brown rice absorbs water more slowly than polished rice. On the other hand, the easily absorbed brown rice of the present invention (treated brown rice)
Has significantly improved water absorption. From these results, the effectiveness of the present invention is clear.

2) As a method for bringing the characteristics of cooked rice closer to that of polished rice while preserving the pigment of pigmented rice, there are conventional techniques such as partial milling and parboiling treatment in which the rice is dried and milled after preliminary steaming. As a result of examining the change in the pigment content and color tone of the treated rice according to the conventional technique, the amount of the pigment extracted by the solvent decreases as the milling yield decreases (closer to the milled rice). The color tone of the transmitted light of the extracted pigment of rice is L
(Brightness) and a (red) decrease, b (yellow) increases,
As a result, the visual red color is impaired (see Table 2).

[Table 2] Table 2 shows the milling ratio, pigment content and color tone of the pigmented rice of purple and black rice. As the fine yield decreases (becomes closer to rice polishing), the amount of pigment decreases. The color tone of the transmitted light of the extracted pigment of rice is L (brightness) and a
(Red) decreases and b (yellow) increases, resulting in a loss of visual red.

When brown rice is pre-steamed, the amount of pigment is remarkably reduced, L and a (red) of the color are reduced, and b (yellow) is increased. As a result, a vivid reddish purple color is lost. (See Table 3).

3) Comparison of pigment characteristics between unabsorbed brown rice and untreated brown rice by the water-absorbing freeze-drying treatment according to the present invention. Little change and no loss of dye on treatment. In addition, the L, a, and b values of the color tone hardly changed, and a vivid color tone was maintained, thus clearly showing the effectiveness of the method of the present invention (see Table 8).

[Table 3] Table 3 shows that brown rice, which is a conventional technique, was preliminarily cooked, and the amount of pigment was remarkably reduced, L and a (red) of color tone were reduced, and b
(Yellow), indicating that the vivid reddish-purple color tone was lost as a result.

4) A comparison was made of the coloring ability of polished black rice and brown rice, which had been easily water-absorbed by freeze-drying with water, when used as a coloring agent. That is, it is the result of mixing 25% of untreated brown rice and brown rice which is easily water-absorbed by a water-absorbing freeze-drying process with Himenomochi polished rice (white rice), and immersing the mixed rice to examine the degree of coloring of the polished rice.

[Table 8] Table 8 shows the results of examining the changes in the pigment content and color tone of the purple and black rice due to the water-absorbing freeze-drying. Changes in the pigment content and color tone due to the treatment are extremely small, indicating the effectiveness of the present invention.

As a result of examining the color tone of the polished rice portion only and examining the color tone by the reflected light, the color tone of the polished rice portion was found to be higher in the zone where the unabsorbed lyophilized brown rice was mixed than in the zone where the untreated brown rice was mixed. Have a lower L value and are more intensely stained.
The color component had a higher a value and a lower b value. That is,
It is clear that brown rice, which is easily absorbed by the water-absorbing freeze-drying treatment, is dyed deeper reddish purple than untreated brown rice (see Table 4).

[Table 4] Table 4 shows the results of a comparison of the coloring ability of polished black rice and brown rice, which has been easily water-absorbed by water-absorbing freeze-drying, when used as a coloring agent. That is, 25% of untreated brown rice having the same pigment amount as the solvent and brown rice easily absorbed by the water-absorbing freeze-drying process are mixed with Himenomochi rice (white rice),
This is the result of examining the degree of coloring of the polished rice by immersing it in water. It is clear that brown rice, which is easily water-absorbed by the water-absorbing freeze-drying treatment, is dyed deeper reddish purple than untreated brown rice.

5) Brown rice swells by absorbing water. By freeze-drying this, only water is removed while maintaining the swollen form, so that the bran layer and endosperm tissue become multi-hole brown rice. It is presumed that this contributes to the improvement of water absorption when brown rice is submerged, the softness of cooked rice properties and brown rice, and the improvement of coloring ability by promoting the dissolution of pigment.

As a result of measuring the bulk density of the brown rice which has been easily water-absorbed by the water-absorbing freeze-drying treatment, the bulk density is clearly lower than that of the untreated brown rice. This is the basis for the increase in the number of holes (see Table 5).

[Table 5] Table 5 shows that the bulk density of brown rice was measured, and as a result, brown rice which had been easily water-absorbed by the water-absorbing freeze-drying treatment had a clearly lower bulk density than untreated brown rice. This is the basis for the multi-hole quality.

6) The hardness of the brown rice easily absorbed by the water-absorbing freeze-drying process is compared with that of untreated brown rice by using "crush hardness" as an index.
It was possible to presume that it was in a polyporous and swollen state (see Table 6).

7) It is the result of examining the relationship between the water soaking time of brown rice and the hardness of freeze-dried brown rice. The hardness decreased as the immersion time became longer. It is apparent from this that the hardness of the treated brown rice can be adjusted by changing the water immersion time (water absorption rate) (see Table 7). Table 6 shows the results of a comparison between the brown rice which is easily water-absorbed by the water-absorbing freeze-drying process and the untreated brown rice, using the "crushing hardness" as an index for the hardness of brown rice. The hardness of the treated brown rice is significantly reduced,
It can be presumed that it is in a swollen state. Table 7 shows the results of examining the relationship between the time of water impregnation of brown rice and the hardness of freeze-dried brown rice. The hardness decreased as the immersion time became longer. It is clear from this that the hardness of the treated brown rice can be adjusted by changing the water immersion time (water absorption rate). Table 9 shows the physical properties of cooked brown rice (Okowa) of brown rice. Compared to untreated brown rice, the easily absorbable brown rice has a lower dynamic elastic modulus and a lower dynamic loss corresponding to texture hardness (softer if less), and a higher loss tangent corresponding to stickiness (higher). Sticky), which is remarkably close to the physical properties of rice bran. This indicates the effectiveness of the present invention.

8) Changes in pigment content and color tone due to water absorption and freeze drying of purple and black rice were examined. As a result, changes in pigment content and color tone due to the treatment were extremely small, indicating the effectiveness of the present invention (see Table 8). .

9) It shows the effect of improving the physical properties of steamed boiled rice (treated rice) of treated brown rice according to the present invention. The treated brown rice has a reduced dynamic elastic modulus and dynamic loss corresponding to texture hardness (softer) than untreated brown rice, and an increased loss tangent corresponding to stickiness (increased stickiness). However, the physical properties in the case of mochi rice are remarkably close. From this, the effectiveness of the present invention is clear (see Table 9).

[0022]

As described above, the method for absorbing brown rice of pigmented rice according to the present invention, by the above-mentioned means, can provide easily absorbed brown rice having no loss of useful pigments and no problems in the Food Sanitation Law. Can be manufactured. The following effects can be obtained by this manufacturing method.

[0023] Pigmented brown rice containing an anthocyan dye or tannin dye in the bran layer is partially mixed with ordinary polished rice and cooked or steamed to obtain colored rice. Rice brown rice is allowed to absorb water for 2-3 days at a low temperature of 5 ° C without deterioration, germination and loss of pigment of brown rice to swell by saturating the amount of absorbed water and freeze-drying it to produce multi-porous expanded brown rice. Use.

[0024] As a result, it is possible to obtain cooked rice that is quick to absorb water when immersed in rice grains, has excellent coloring efficiency, has no problems in the Food Sanitation Law, and has little uncomfortable feeling when mixed and cooked with ordinary rice.

[0025] This brown rice is highly convenient, and because it is a safe natural colorant derived from food, it enhances the image of colored foods and can contribute to the development of the food industry such as the confectionery industry. It can also contribute to expanding demand for rice.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Norio Ogawa 1-4-3 Inada, Joetsu-shi, Niigata Inada Housing No. 3 Building 201 (56) References JP-A-53-145943 (JP, A) 6-311859 (JP, A) JP-A-6-303927 (JP, A) JP-A-62-14752 (JP, A) JP-B-3-3420 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) A23L 1/10 A23L 1/275

Claims (1)

(57) [Claims] 1. A rice grains purple rice or red rice brown rice containing bran layer useful dye in water to colored rice and water absorption methods pigmented rice brown rice utilized to its processed foods, the pigmented rice When brown rice is used as a colorant for cooked rice or as cooked rice, the production of easily absorbable brown rice with little discomfort in terms of texture and extremely little loss of useful pigments and change in color tone from that of ordinary polished rice is effective. The pigmented rice brown rice is allowed to absorb water for 2-3 days at a low temperature of 5 ° C. without deterioration, germination, and loss of pigment of brown rice to swell by saturating the amount of absorbed water .
This is freeze-dried into multi-hole expanded puffed brown rice, which makes it easy to absorb water when the rice grains are soaked and has excellent coloring efficiency. A method for making pigmented rice brown rice water-absorbent, characterized in that it is obtained.