JP2015107069A - Method for producing sprouted brown rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing sprouted brown rice suppressed in proliferation of microorganisms, and enriched in GABA.SOLUTION: Brown rice is sprouted while pressurizing in a pH4-6 buffer solution so as to perform an enrichment enzyme reaction of GABA. It is preferable to previously reduce pressure followed by pressurizing. The enrichment enzyme reaction is performed preferably in an anaerobic condition like a carbonic acid gas atmosphere. It is further preferable to repeat application of pressure/normal pressure. The previous addition of glutamic acid increases GABA in a final product. The sprouted brown rice thus obtained is suppressed in proliferation of microorganisms in a sprouting process so as to have no putrid odor and be excellent in taste. Furthermore, since the enzyme reaction is promoted, GABA excellent in antioxidant activity and healthy function is richly contained.

Description

  The present invention relates to a method for producing germinated brown rice. More specifically, the present invention relates to a method for producing a good-tasting germinated brown rice enriched with GABA (γ-aminobutyric acid) necessary for antioxidant activity and health function.

  Regarding the health function of GABA, it is known as a neurotransmitter that prevents and treats hypertension and increases the amount of oxygen supply to the brain to calm cerebral nerve spasms and excitement. In addition, for the brain, headache, tinnitus, memory impairment, improvement of decreased consciousness, promotion of learning ability, prevention and improvement of Alzheimer-type dementia, suppression of blood cholesterol and blood lipid increase, arteriosclerosis Suppression, prevention and improvement of diabetes, liver improvement by improving blood flow, improvement of kidney function, alcohol metabolism promotion, prevention and suppression of colorectal cancer, body odor elimination, stiff shoulders, improvement of tinnitus, prevention of obesity, improvement of insomnia It is known to have an effect on neurological disorders.

  Thus, the necessary amount of GABA having many effects has been understood, and the necessary amount is as follows. 10-50 mg / day for health maintenance (increases with age), 200-500 mg / day for calming action, 300-600 mg / day for improvement of depression, stress relief; 100-300 mg / day required Has been.

  GABA, a kind of amino acid, was said to be very safe and not harmful to overdose, but in recent studies, it is not strong, but lip spasms, palpitation, shortness of breath, etc. when ingested over 1000 mg / day It has been reported that symptoms may occur. Although GABA is contained in a relatively wide variety of foods, there is no harm of overdose only by taking from foods without taking supplements or the like, and there is often no manifestation of effects due to lack. At present, the number of germinated brown rices on the market is 15 mg / 100 g, but the value actually measured by the inventor was 10 mg / 100 g or less. In the usage method, germinated brown rice is mixed with white rice for about 20% and is cooked. With this amount, the minimum daily requirement of GABA cannot be taken from rice.

Furthermore, commercially-sprouted brown rice has a bad smell and a different taste, and many buyers often stop using it. Although GABA's effects are recognized and used as medicines and supplements, it is very unfortunate that consumers do not like germinated brown rice that is most suitable for daily consumption as a food containing all nutrients. is there.
The unpleasant odor and taste of conventional germinated brown rice is understood to be caused by spoilage caused by microorganisms attached to the brown rice when germinated. The present inventor has so far studied to prevent the decay of the immersion liquid during the GABA enrichment operation, developed a method for removing microorganisms from the immersion liquid, and applied this to pigmented rice (Patent Literature). 1)

In order to prevent rot of brown rice, removal of microorganisms in the immersion liquid and prevention of growth can be mentioned. The removal of microorganisms adhering to brown rice is possible by thorough washing of the brown rice, and the removal of microorganisms can prevent the decay of brown rice, but if the GABA enrichment time is long, the number of microorganism removal operations of the immersion liquid during the GABA enrichment process This increases the amount of soaking liquid and the concentration of brown rice in the final process, affecting the price of GABA-enriched brown rice.
In addition, the germinated brown rice so far has literally been operated to germinate the brown rice, and the germ part is swollen and the germination ends when the bud ends up to 3 mm. I have not reached my eyes. For this reason, the GABA amount of the commercially germinated brown rice is 15 mg / 100 g of brown rice and the amount of GABA required for one day is not far. For example, Patent Document 2 discloses a method for producing sterile germinated brown rice in which brown rice is sterilized in advance and enclosed with carbon dioxide to germinate, but this method does not disclose anything regarding enrichment of GABA. Absent.

JP 2011-30482 A JP 2002-45135 A

  The glutamic acid decarboxylase (enzyme) contained in the germ of brown rice decarboxylates the glutamic acid in brown rice at the time of germination of brown rice to produce GABA. The energy at that time is used for germination, and after germination, Is known to disappear. That is, the production of GABA is an enzymatic reaction, and it is considered that the production of GABA can be maximized by strictly measuring and controlling the activity of the enzyme during germination.

  In germination of cultivated brown rice, the microorganisms of the outer skin are not related, but when using brown rice enriched with GABA for food, it is a big problem. Since the optimum temperature for enzyme activation is 37 to 40 ° C. and desirable temperature for microorganisms, brown rice is usually spoiled at the same time as GABA enrichment. In previous methods for producing germinated brown rice, it was also possible to wash away microorganisms by pouring immersion water, but pouring hot water at 40 ° C was difficult from the cost standpoint, and at the end of the process, it was difficult to do so. They simply discard the water and collect and dry only the brown rice.

  As a result of various studies, the present inventor has found that the water-soluble components of brown rice elute into the immersion liquid during the immersion of brown rice, and GABA produced by concentrating and drying the germinated brown rice and the immersion liquid together with others We thought that all useful components could be recovered. Therefore, if the GABA-enriched enzyme reaction can be speeded up, the soaking time of brown rice can be shortened and the growth of microorganisms can be suppressed. I thought about how to promote contact between the enzyme and glutamic acid.

As a result, the contact between glutamic acid and the enzyme can be promoted by changing the pressure of the brown rice containing the immersion liquid in order to promote the penetration of the immersion liquid into the brown rice and the flow of the immersion liquid in the brown rice. The GABA production time can be greatly shortened, it is possible to avoid spoilage by microorganisms, and germinated brown rice having no off-flavor can be produced.
Accordingly, an object of the present invention is to provide a method for producing germinated brown rice in which the growth of microorganisms is suppressed and GABA is enriched.

As a result of intensive studies, the present inventor has promoted contact between glutamic acid and the enzyme by pressurizing contact between the enzyme present in the germ and glutamic acid, preferably by pressurizing after decompression, and GABA from glutamic acid. The inventors have found that the production rate of can be increased, and have reached the present invention.
That is, the present invention is as follows.
1. A method for producing germinated brown rice, comprising a step of pressure-treating brown rice in a buffer solution having a pH of 4 to 6, wherein GABA is enriched and bacterial growth is suppressed.
2. A method for producing germinated brown rice in which GABA is enriched and bacterial growth is suppressed, comprising a step of subjecting brown rice to a pressure treatment in a pH 4-6 buffer solution followed by a pressure treatment.
3. The manufacturing method according to 1 or 2 above, wherein the pressing is performed in a carbon dioxide atmosphere.
4). 4. The method of 1, 2 or 3 above, wherein after pressurization, the pressure is returned to normal pressure and pressurized again.
5. 4. The production method as described in 4 above, wherein the pressure / normal pressure cycle is carried out twice or more.
6). 6. The method according to any one of 1 to 5, wherein the buffer solution is an acetate buffer solution, a citrate buffer solution, or a lactic acid buffer solution.
7). Glutamic acid is added and processed, The manufacturing method of any one of said 1-6 characterized by the above-mentioned.

The germinated brown rice obtained according to the present invention is excellent in taste because there is no rot odor because the growth of microorganisms in the germination process is suppressed. Moreover, since an enzyme reaction is accelerated | stimulated, it contains abundant GABA excellent in antioxidant activity and health function. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide germinated brown rice that can take GABA in an amount necessary for maintaining health by taking rice twice a day. Furthermore, the Maillard compound was produced by the reaction between the water-soluble sugar produced during the GABA production operation and the proteolysate, and germinated brown rice having an antioxidant ability far exceeding the antioxidant activity of conventional brown rice could be produced.
In addition, when brown rice is immersed in water, there is no elution of the enzyme in the germ, but it is understood that the brown rice hull swells and the water-soluble components of rice are eluted in the immersion liquid, and it is concentrated including brown rice and immersion liquid. It was possible to completely recover the GABA produced in the above and at the same time completely prevent the loss of nutrients contained in the rice.

The brown rice of the present invention may be normal brown rice or pigmented rice.
In the present invention, the germination of brown rice is carried out in a buffer solution with a controlled pH, but it is preferable to wash the raw brown rice in advance to remove microorganisms and dust adhering to the epithelium as much as possible. Washing may be performed with water or with 0.1 to 1N sodium hydroxide, sodium carbonate or sodium bicarbonate, followed by water. The cleaning may be performed by, for example, sharpening or an ultrasonic cleaner. Further, it is preferable to perform aseptic tap water cleaning. After washing, the brown rice is separated from water by filtration or the like. This operation is preferably performed once to several times. In this way, it is preferable to keep the amount of microorganisms in the raw brown rice at about 5 × 10 cfu.

A buffer solution is added to the sufficiently washed brown rice to adjust the pH to 4 to 6, preferably 4.5 to 5 at a temperature of 15 to 40 ° C, preferably 30 to 40 ° C. Preferably, the air contained in the brown rice is removed by reducing the pressure. Although there is no restriction | limiting in particular in the quantity of a buffer solution, It is 50-100 mass parts normally with respect to 100 mass parts of brown rice, Preferably it is 60-100 mass parts. Thereafter, pressurization is performed so that the immersion liquid sufficiently penetrates into the brown rice, and the glutamic acid dissolved in the immersion liquid is sufficiently brought into contact with the enzyme. Thereby, an enzyme reaction can be accelerated | stimulated and the enrichment of GABA can be aimed at. Next, the pressure is returned to normal pressure.
After GABA enrichment using a buffer solution, the pH of the solution is adjusted to about 6 if necessary, and then concentrated and dried, so that there is no acid odor or acidity of the buffer, and GABA is enriched. Germinated brown rice can be obtained.

  In the present invention, oxalic acid, citric acid or lactic acid buffer is preferably used as the buffer. In order to reduce the amount of immersion liquid used, it is important to reduce the number of operations for removing microorganisms during GABA enrichment. Therefore, it is conceivable to delay the growth of microorganisms during treatment by reducing the amount of immersion liquid used by imparting antibacterial properties to the immersion liquid. As a result of various studies, the present inventor decided to use an antibacterial buffer solution because it is food, has no inactivation of brown rice enzyme, and has an optimum pH of the immersion liquid of 4. Since it is 5-6, the said buffer solution was used as a buffering agent with preferable flavor. By using such a buffer solution, it is possible to eliminate the operation of removing microorganisms during GABA enrichment.

  The pressure for depressurization is not particularly limited and may be smaller than the atmospheric pressure, but the larger the degree of vacuum, the better. Usually, the mercury column is 750 mmHg or less, preferably 400 mmHg or less, and more preferably 200 mmHg or less. The pressurization is not particularly limited but is usually 0.1 to 5 MPa, preferably 0.1 to 1 MPa in terms of gauge pressure. The decompression is preferably performed for 10 to 30 minutes and the pressurization is performed for 1 to 5 hours.

  Next, the pressurization is released and the pressure is returned to normal pressure, so that the immersion liquid penetrates into the brown rice. Preferably, after a certain period of normal pressure, for example, 1 to 5 hours, GABA production is measured over time by repeating the pressurization and normal pressure operation once to several times, and the reaction is performed when the maximum amount is reached. finish. By such an operation, the GABA generation time can be greatly shortened. For example, what conventionally took 3-7 days would be 24-35 hours.

  In the present invention, the GABA enrichment reaction is preferably performed in a carbon dioxide atmosphere. GABA enrichment reactions using brown rice enzymes are always at risk of microbial growth. The reaction in the atmosphere shows the growth of mold, yeast and aerobic microorganisms. The present inventor has found that the growth of these microorganisms is suppressed by filling the reaction vessel with antibacterial carbon dioxide. That is, using a food material that is antibacterial as a buffer for the immersion liquid, removing the air in the reaction vessel by a depressurization operation, and pressurizing with carbon dioxide gas during the pressurization operation, Proliferation of microorganisms can be suppressed, and GABA-enriched brown rice with a delicious flavor that is not a germinated brown rice with a different taste and smell can be made.

  Moreover, in the manufacturing method of this invention, glutamic acid can also be added and enriched to brown rice. It is difficult to convert all glutamic acid materials in brown rice to GABA, and the amount of GABA produced is limited. When a glutamic acid is added to the immersion liquid and a GABA enrichment reaction is performed, the GABA amount increases corresponding to the amount of glutamic acid added. However, the amount of glutamic acid converted is limited by the enzyme activity, and when a large amount of glutamic acid is added, the taste of unreacted glutamic acid remaining in the produced germinated brown rice tastes. In order to produce delicious germinated brown rice, the amount of GABA enrichment is limited in relation to the enzyme activity of brown rice. Although the addition amount of glutamic acid depends on the enzyme activity of brown rice, it was possible to obtain germinated brown rice with no sense of incongruity in the addition range of 0.2 to 3% by mass of sodium glutamate relative to the amount of brown rice. However, the residual amount of glutamic acid can be freely changed depending on the use of germinated brown rice.

The following examples illustrate the invention.
Comparative Example 1
Put 400 g of brown rice in a 1 L eggplant flask, ultrasonically wash with an equal amount of tap water for 4 minutes, rinse with gauze to discard the wash water, and wash with tap water again. This operation was repeated 6 times. The microbial content of the washed brown rice was 4 × 10 ² cfu. The washed brown rice was put into a 1 L eggplant flask, 400 ml of 0.1M oxalate buffer solution having a pH of 5 was added, and reacted in a constant temperature bath at 40 ° C. The amount of GABA was measured periodically during the reaction, and the reaction was completed in 98 hours when the maximum amount was reached. The produced germinated brown rice and the buffer solution were concentrated and dried together. The amount of microorganisms in the buffer before concentration was 6 × 10 ³ cfu, and the GABA amount of germinated brown rice was 42 mg / 100 g brown rice.

Example 1
An equal amount of 0.1N NaOH water was added to 400 g of brown rice, washed with shaking, and then washed with an ultrasonic cleaner for 4 minutes. The washing water was filtered with gauze, and the same amount of washing water was added again for washing in the same manner. When this operation was repeated twice and washed four times with sterile tap water, the number of microorganisms was 2 × 10 cfu.
The washed brown rice is charged into a pressure vessel, deaerated with a vacuum pump for 20 minutes, and 400 ml of a pH 5 oxalate buffer solution is sucked and injected into the reduced pressure vessel. Further, carbon dioxide gas was injected so that air was not introduced, the pressure was increased to 0.3 MPa, and the reaction was started in a constant temperature bath at 40 ° C. When pressurization with carbon dioxide gas was continued for 1 hour, the valve was opened to release carbon dioxide gas. When the pressure inside the container reached normal pressure, the valve was closed and the enzyme reaction was continued in a carbon dioxide gas atmosphere for 36 hours. Germinated brown rice was concentrated and dried together with a buffer solution. The number of microorganisms in the buffer just before the completion was 3 × 10 ² cfu, and the GABA amount was 47 mg / 100 g brown rice.

Example 2
400 ml of 0.1N sodium bicarbonate (sodium bicarbonate) was added to 400 g of brown rice, and the brown rice was washed in the same manner as in Example 1. The microorganism of the washed brown rice was 3 × 10 cfu. The washed brown rice is put into a reaction vessel and the pressure is reduced, and a pH 5 succinate buffer is sucked and injected in the same manner as in Example 1, and the vessel is filled with carbon dioxide gas. The reaction is carried out in a carbon dioxide atmosphere at normal pressure for 3 hours and at a temperature of 40 ° C., and after 3 hours, carbon dioxide is injected and pressurized to 0.3 MPa for 3 hours. Thereafter, carbon dioxide gas is released and the pressure is returned to normal pressure. The reaction is continued at normal pressure for 3 hours, and carbon dioxide pressure is again applied after 3 hours. This operation was repeated and the reaction was completed in 36 hours. After the reaction, the pH of the buffer solution was adjusted to 6, and both the buffer solution and brown rice were concentrated and dried. The microbial content of the buffer before concentration was 3 × 10 ² cfu, and the GABA content of germinated brown rice was 64 mg / 100 g brown rice.

Example 3
Brown rice was filled into the reaction vessel in the same manner as in Example 2, and the pH 5 oxalate buffer was sucked and injected under reduced pressure. Subsequently, the pressure was increased to 0.3 MPa with carbon dioxide gas for 1 hour, and thereafter, pressurization and normal pressure were repeated every hour. The repetitive reaction was completed in 24 hours. The amount of microorganisms in the buffer at the end of the reaction was 2 × 10 ² cfu, and the GABA amount was 56 mg / 100 g brown rice.
The effect of greatly shortening the reaction time by performing the GABA enrichment reaction by combining pressure changes is great, but a special device is required when incorporating a vacuum, and the effect is not recognized at the weak vacuum and the first degassing. Use was most effective. Even if the interval between repeated reaction times of pressurization and normal pressure is too small, it does not differ so much, and it is considered that it is desirable to carry out at intervals of 1 to 5 hours.

Example 4
It carried out similarly to Example 3 using the citric acid for the buffer solution to be used. The amount of microorganisms in the buffer after completion of the reaction for 24 hours was 6 × 10 ² cfu, and the amount of GABA was 58 mg / 100 g brown rice.

Example 5
The enzyme reaction was performed in the same manner as in Example 3 using lactic acid as the buffer solution to be used. After a reaction time of 24 hours, it was concentrated and dried in the same manner as in Example 3. The amount of microorganisms contained in the buffer before concentration was 2 × 10 ² cfu, and the GABA amount of germinated brown rice was 62 mg / 100 g brown rice. Both buffers suppressed microbial growth during the reaction.

Example 6
The enzyme reaction was performed in the same manner as in Example 2 except that the amount of the buffer solution to be added was reduced to 60% of the amount of brown rice. The reaction was terminated after 84 hours. The amount of microorganisms at the end of the reaction was 2 × 10 ³ cfu, and the amount of GABA was 42 mg / 100 g brown rice.
If the brown rice can be sufficiently immersed and stirred, a small amount of immersion is desirable to facilitate the concentration operation. It was found that there is no need for the same amount as brown rice, and a buffer solution amount of about 60% may be used.

Example 7
In the enzyme reaction, it was found that water-soluble sugars and proteins were dissolved in the buffer solution, and in order to further increase the amount of GABA, 0.5% sodium glutamate was added to brown rice in the same manner as in Example 2. Tested. The amount of GABA in germinated brown rice at the end of the reaction after 24 hours was 182 mg / 100 g brown rice.
The amount of sodium glutamate was added at 1 to 3%, but the taste of sodium glutamate remaining in the germinated brown rice was so strong that it was not preferable for ingestion as it was, and it is desirable to keep it at 0.5% or less.

Example 8
In the same manner as in Example 4, 400 g of brown rice was dissolved in 250 ml of a buffer solution of 1% sodium glutamate with respect to brown rice and injected into a reaction vessel, and pressurization and normal pressure were repeated every 3 hours for 24 hours. The amount of microorganisms at the end of the reaction was 3 × 10 ² cfu, and the amount of GABA was 186 mg / 100 g brown rice.

Example 9
400 ml of a buffer solution was added to 400 g of brown rice, 0.5% sodium glutamate was added to the buffer solution, and the same treatment as in Example 3 was performed. The reaction time was extended to 36 hours. After completion of the reaction, the GABA content of the concentrated and dried product was 220 mg / 100 g brown rice. The amount of microorganisms in the buffer before concentration was 6 × 10 ² cfu.

Example 10
Sodium glutamate 5% was added, and germinated brown rice was obtained in the same manner as in Example 3 below. As a result, the amount of microorganisms in the buffer before concentration was 5 × 10 ² cfu, and the amount of GABA produced was 173 mg / 100 g brown rice. The taste of glutamic acid remaining in the germinated brown rice was strong.

In Japan, rice consumption is declining, but consumers are becoming more health conscious. The global brown rice market currently in circulation is about 400 million tons of rice, but it is the most excellent brown rice for human beings in the world because of its unit yield, adaptability to continuous cropping, and nutritional value of rice. Until now it was food in the Southeast Asian monsoon zone, but recently it has been cultivated in the African continent. The nutritional value of rice, which is the main food, is greatly reduced in white rice. However, although brown rice is hard even after cooking, it cannot be said that it has a good taste, but by performing the GABA enrichment operation, the nutritional value increases, the brown rice hull becomes soft, and the texture is greatly improved. The germinated brown rice of the present invention is expected to have a good flavor, a high nutritional value, and a good texture, so that it can be returned to rice. Furthermore, about 100 mg of GABA will be consumed by ingesting a bowl of rice, and once a healthy person contains an amount sufficient to satisfy the amount of GABA required for a day to maintain health. You can get enough GABA just by eating rice.

Claims (7)

  A method for producing germinated brown rice, comprising a step of pressure-treating brown rice in a buffer solution having a pH of 4 to 6, wherein GABA is enriched and bacterial growth is suppressed.   A method for producing germinated brown rice in which GABA is enriched and bacterial growth is suppressed, comprising a step of subjecting brown rice to a pressure treatment in a pH 4-6 buffer solution followed by a pressure treatment.   The method according to claim 1 or 2, wherein the pressurization is performed in a carbon dioxide atmosphere.   4. The process according to claim 1, wherein the pressure is returned to normal pressure after pressurization and then pressurized again.   The manufacturing method of Claim 4 which performs the cycle of pressurization and normal pressure twice or more.   The production method according to claim 1, wherein the buffer solution is an acetate buffer solution, a citrate buffer solution, or a lactic acid buffer solution. Glutamic acid is added and processed, The manufacturing method of any one of Claims 1-6 characterized by the above-mentioned.