JP5207408B2 - Method for producing silica-containing food - Google Patents

Description

The present invention relates to a method for producing a silica-containing food extracted from rice hulls grain.

Conventionally, silica (SiO ₂ ) has been widely used as an inorganic material such as semiconductors, optical fibers, solar cells, various fine ceramics, and concrete reinforcing materials. Since silica and its silicic acid are substances contained in large amounts in soil (minerals), silica has conventionally been purified and extracted from soil. However, in recent years, the soil containing silica with high purity is decreasing, and the cost of transporting and refining the soil is high, so various new silica sources are being studied.

As this silica source, plants that have absorbed and accumulated silica in soil are most expected. In particular, since rice husks of grains such as rice and wheat contain high-purity silica (SiO ₂ ), for example, silica is extracted from rice husks as disclosed in Patent Documents 1 and 2 below. Technology has been proposed.

  First, Patent Document 1 discloses a method for synthesizing zeolite using cereal rice husk ash. In this method, a hydrothermal synthesis reaction is performed using a silicon-containing alkaline solution obtained by reacting cereal rice husk ash with an aqueous alkaline solution as a silica source.

  Patent Document 2 discloses a method for producing high-purity amorphous silica from rice husks or straws. In this method, rice husk is immersed in an acetic acid-containing solution to elute potassium, which is an alkaline component contained in rice husk, and then pyrolyzed at a low temperature (350 to 650 ° C.) to produce rice husk ash. Is baked at 600 to 700 ° C. to produce rice husk ash containing amorphous silica in high purity. In this method, by separating the alkali components of rice husks before pyrolysis or firing, silica and alkali components are combined during combustion to capture unburned carbon, and unburned carbon (incombustible material) ) Can be solved (Claim 1, Paragraph [0003], [0008], etc. of Patent Document 2).

  On the other hand, silica is an essential element (component) contained in minute amounts in skin, bones, cartilage, tendons, blood vessels, teeth, nails and the like in the living body. Recent research is proving that silica has functions such as prevention of various adult diseases such as diabetes and hypertension, prevention of osteoporosis, anti-aging, and skin beautification. However, since silica cannot be produced in the body and 10 to 40 mg is consumed per adult day, it can only be replenished daily with vegetables such as spinach and cucumbers and supplements. In particular, the amount stored in the body (storage function) decreases with age, so it is necessary to actively replenish it with daily meals and supplements.

  In addition, plant-derived silica is known for its pharmacokinetics, unlike many other ingredients contained in dietary supplements (generic name for functional foods, health foods, supplements, etc.). Specifically, the silica concentration in the serum rises about 120 minutes after ingesting the food containing silica, and is excreted from the urine to the outside over 3 to 9 hours. That is, silica ingested from the outside is rapidly absorbed from the intestinal tract and fulfills various functions in the living body, and is then discharged from urine in a short time. Therefore, it is possible to accurately grasp the intake amount, the intake cycle, and the form (drug form, etc.) in consideration of the function and age in the body.

  Among plants, the above-described rice husks have the advantage that they contain high-quality silica in high purity and can be easily and inexpensively obtained in large quantities every year. In addition, it is preferable to effectively use a large amount of rice husk, which is agricultural waste, from the viewpoint of protecting the global environment. Therefore, in recent years, it has been proposed to use silica contained in grain chaff for food. For example, in the following Patent Documents 3 and 4, it is proposed to use silica extracted from rice husks for food (including beverages).

JP-A 64-037412 JP 2008-214158 A Japanese Patent Laid-Open No. 2005-232066 International Publication No. 07/026680 Pamphlet

By the way, since silica contained in rice husks is poor in water solubility as it is, it is difficult to be absorbed into the body even when used for food. From this point of view, it is conceivable that the rice husk is fired to modify the silica into a water-soluble form so as to be easily absorbed in the body.
In the above Patent Documents 1 and 2, the purpose is to use silica extracted from rice husks for industrial products such as semiconductors and concrete admixtures. It is not considered at all. For example, in Patent Document 1, in order to extract silica efficiently, the rice husk is baked at a high temperature of 1000 ° C. or higher so that impurities are surely lost. Therefore, most of the silica is crystallized, resulting in a decrease in water solubility and carcinogenicity.

  In Patent Document 2, rice husk from which potassium is eluted is fired in two stages by changing temperature conditions and the like. For this reason, setting and management of the firing temperature, transportation between processes, and the like are complicated, and the manufacturing cost may increase. This patent document 2 is intended not only for refining high-purity silica but also for obtaining by-products such as koji vinegar and tar during the production process, and for reusing the calcined exhaust gas (paragraph [0007], etc.). ). Since a special process is required for this purpose, there is a limit to simplifying the manufacturing method.

  Furthermore, Patent Documents 3 and 4 all point out that silica derived from rice husks can be used for foods, the efficacy of silica-containing foods, etc., and the shape and physical properties of silica including the firing temperature of grains. There is no disclosure of a specific manufacturing method that takes into account the above.

  The present invention has been made in view of the above circumstances, and can utilize plant-derived natural silica extracted and purified from cereal husks and natural alkaline spring water, and is easy to process and safe. It is an object to provide a cheap and inexpensive silica-containing food and a method for producing a silica-containing food.

  The inventors of the present invention have completed the present invention through repeated studies by paying attention to the presence of natural alkaline water in which silica is well dissolved.

  That is, this invention provides the manufacturing method of the silica containing foodstuff which has the following characteristics, and a silica containing foodstuff.

In the first aspect of the present invention, (a) a process of obtaining rice husk ash by burning grain husks at 500 to 800 ° C., and (b) adding and mixing alkaline natural mineral water to the obtained rice husk ash. And a process for producing a silica-containing food comprising the steps .
In the step (b), alkaline natural mineral water containing at least one of hydrogen carbonate ion, metasilicate ion, calcium ion, sodium ion, chloride ion, sulfate ion, magnesium ion and potassium ion is mixed with silica. May be.
The step (b) may further include a step of adjusting the natural mineral spring water to a weakly alkaline pH of 8.0 to 8.2.
The rice husk may be pulverized by a pulverizer (mill).
Furthermore, (c) You may provide the process of adjusting the pH of the liquid mixture produced | generated at the said (b) process, and / or the density | concentration of a silica.
Furthermore, (d) a step of adding a food additive derived from a natural product, at least any food additive of a food pigment, a nutritional supplement material, a taste control material, or a mineral component to the mixed solution generated in the step (b), May be provided.
The rice husk may be washed by a reflux method using dilute hydrochloric acid.
The rice husk may be dried with warm air and / or sunlight.

  According to the present invention, since a plant-derived natural silica extracted and purified from cereal husks and natural alkaline water are used, a silica-containing food can be produced safely and inexpensively.

It is the schematic process drawing which showed one Embodiment of the manufacturing method of the silica containing foodstuff which concerns on the 1st aspect of this invention.

First aspect
The method for producing a silica-containing food according to the first aspect of the present invention includes (a) a step of baking rice husks of grains to obtain rice husk ash, and (b) adding alkaline natural mineral water to the obtained rice husk ash. Mixing.
Hereinafter, each step will be described.

First, in the step (a), rice husks of grains are fired to obtain rice husk ash.
As the cereal, any cereal that accumulates silica in the tissue can be used. Specifically, rice, wheat, and sugarcane are preferable, and rice is particularly preferable because of its high silica content.
The method for collecting rice husks from grains is not particularly limited, and can be performed by a known method using a hulling machine or the like.
The rice husk is preferably washed in advance for the purpose of removing residual agricultural chemicals. The method for washing rice husk is not particularly limited, but is preferably washed by a reflux method using dilute hydrochloric acid.
The rice husk is preferably dried in advance. The method for drying rice husk is not particularly limited, but a method of drying with hot air and / or sunlight is preferable. When drying in the sun, it is preferable to apply it to the sun for about 1 to 3 days. The drying of the rice husk may be performed on the washed rice husk or may be performed on the unwashed rice husk.

Furthermore, the rice husk prepared as described above is preferably pulverized in advance. By crushing into a rice husk powder before firing, uniform firing is possible and the bulk density is increased, which is advantageous in terms of conveyance and downsizing of the manufacturing apparatus.
The pulverization method is not particularly limited, and can be performed by a known method using a pulverizer (mill) or the like. As the pulverizer, a jet mill is preferable.
The grain size of the chaff after pulverization is preferably 10 μm to 1 mm, more preferably 50 to 500 μm, and even more preferably 100 to 300 μm. Moreover, the water content, shape, etc. of the chaff after pulverization can be arbitrarily adjusted.
The rice husk or rice husk powder obtained as described above can be conveyed to a firing furnace or the like using a hopper or the like.

The method for baking rice husk is not particularly limited, and can be performed by a known method using a rotary electric furnace, a fluidized bed combustion furnace, a muffle furnace, or the like.
Since the melting point of silica is as high as about 1400 to 1600 ° C., by burning the rice husk below this temperature, components other than silica are almost lost, and rice husk ash containing silica with high purity is obtained. However, since the firing temperature has a great influence on the form of silica, it is preferably adjusted as follows.
Specifically, the firing temperature is preferably 500 to 800 ° C, more preferably 580 to 650 ° C, and particularly preferably about 600 ° C. This is because the shape and properties of silica and the combustion state of silica vary greatly depending on the combustion temperature, as is widely known.
That is, when calcined at a low temperature of less than 500 ° C., the calcining of components other than silica becomes insufficient, the components remain in a carbonized state, the silica purity of rice husk ash is lowered, and the production efficiency is lowered. .
On the other hand, when baked at a high temperature exceeding 800 ° C., impurities other than silica burn almost completely and the silica purity increases, but part or all of the silica is crystallized. Therefore, the water-solubility of silica is greatly reduced, and not only absorption in the body becomes difficult, but also a harmful substance to the human body, making it difficult to use as food.
As described above, since the form of silica contained in rice husk ash varies depending on the firing temperature, temperature control during firing is very important. In particular, when the rice husk reaches the ignition point (about 350 to 400 ° C.), the combustion proceeds rapidly, and the temperature in the furnace may increase rapidly. In that case, the temperature inside the furnace is constantly monitored, and when it reaches the vicinity of the ignition point, the output is reduced, the supply amount of oxygen is reduced, or a small amount of room temperature air or cooling air is supplied. It is preferable to suppress a rapid temperature rise.

  The burning time of rice husk is the particle size and water content of rice husk or rice husk powder, the type and content of impurities depending on whether or not the rice husk is washed, the type of baking equipment (continuous baking, intermittent baking, rotary type, stirring type) Etc.), the atmosphere during firing (whether oxygen gas, argon gas, etc. are supplied, etc.) can be appropriately adjusted, but it is preferably about 30 minutes to 4 hours.

  By burning rice husk or rice husk powder as described above, impurities other than silica disappear almost completely, and rice husk ash containing 99% or more of high-purity silica is obtained. The silica in the rice husk ash not only retains the same amorphous state as at room temperature, but also has a mesoporous structure unique to rice husk silica, so that the alkali water solubility is remarkably improved. Dispersion stability is improved because it is colloidally dispersed in natural mineral water.

By appropriately selecting the conditions, the rice husk ash obtained can be used as it is because it consists essentially of silica, but if necessary, impurities are separated. Here, the impurities refer to components other than silica, such as scum of other inorganic components, in the rice husk ash obtained in the step (a).
The method for separating rice husk ash is not particularly limited, and can be performed using a known method such as a centrifugal separation method, a precipitation method, or a filtration method. Also, silica and impurities in rice husk ash can be separated by washing rice husk ash by a reflux method using an acidic solution as washing water. Use of this method is preferable because impurities can be removed without losing silica that is hardly soluble in acid. Here, as an acidic solution, the solution containing dilute hydrochloric acid etc. may be sufficient and the natural water which shows acidity may be sufficient. Moreover, it is preferable that it can be used in a food manufacturing process.

Next, in step (b), alkaline natural mineral water is added to and mixed with rice husk ash containing silica obtained in step (a).
By the step (b), a mixed solution of rice husk ash containing silica and alkaline natural mineral water is obtained.
Here, the alkaline natural mineral water satisfies all the following requirements.
1) Naturally produced water.
2) The pH should be 8.0 or higher.
3) It must not contain any ingredients harmful to the human body, or it must contain very subtle details.
In addition, the mineral spring water in the present invention is a concept that includes all natural water that satisfies the above-mentioned requirements regardless of whether or not the conditions stipulated by the relevant laws and regulations of Japan and other countries are satisfied. The temperature of the water, the amount of spring water, etc. are not included in any of the necessary and preferred conditions.

As is well known, since silica easily dissolves in an alkaline solution, a silica solution can be easily obtained by mixing rice husk ash containing silica and alkaline mineral water.
The pH of the alkaline natural mineral water is preferably weakly alkaline with a pH of about 8.0 to 8.2. If the pH is less than 8.0, the silica is not sufficiently dissolved in the alkaline natural mineral water. If the pH exceeds 8.2, irritation to the mucous membrane is strong and unsuitable for food. Further, the alkaline natural mineral spring water may be adjusted to be weakly alkaline with a pH of 8.0 to 8.2 by pretreatment. The pretreatment method is not particularly limited, and can be carried out using a pH adjuster or the like usually used for adjusting the pH of foods or the like.

  Moreover, it is preferable that alkaline natural mineral water contains a mineral component useful for the human body. The mineral component preferably contains at least one of hydrogen carbonate ions, metasilicate ions, calcium ions, sodium ions, chloride ions, sulfate ions, magnesium ions, and potassium ions. Furthermore, it is preferable that the alkaline natural mineral water is colorless, tasteless and odorless considering that it is used as a food.

  For example, the mineral spring water that springs out in Kashihara, Kamakura City, Kanagawa Prefecture, is very preferable because it can be used without pretreatment such as pH adjustment because it satisfies almost all of the above-mentioned necessary and preferable conditions. Furthermore, since this mineral spring water contains abundant metasilicic acid which is a silica oxide (about 70 mg / L), it is useful as a functional water as it is. A food containing this mineral spring water and amorphous silica produced from rice husk can be a highly functional food containing silica at a very high concentration.

The mixing ratio of silica and natural mineral water can be appropriately determined depending on the type of food, etc., but generally a range of 10 to 30 mg of rice husk ash containing silica is preferable with respect to 1 liter of natural mineral water. .
The method for mixing the rice husk ash containing silica and the alkaline natural mineral spring water is not particularly limited, and can be performed by a known method such as using a stirrer. Moreover, when mixing, in order to accelerate | stimulate a hydrothermal reaction, it is preferable to heat the liquid mixture which consists of rice husk ash and alkaline natural mineral spring water to about 50-100 degreeC.

In this invention, the following (c) process can be performed after a (b) process.
(C) A step of adjusting pH and / or silica concentration of the mixed solution produced in the step (b).
The method for adjusting the pH is not particularly limited, and can be performed using a pH adjuster or the like usually used for adjusting the pH of food or the like.
The method for adjusting the concentration of silica is not particularly limited, and can be appropriately concentrated or diluted using a known method.

Moreover, the following (d) process can be performed after the (b) process.
(D) A step of adding a food additive derived from a natural product, at least one of a food colorant, a nutritional supplement material, a taste control material, and a mineral component, to the mixed solution generated in the step (b).
Here, food pigments, nutritional supplement materials, taste-adjusting materials, and mineral components are particularly limited as long as they are usually added to foods, etc., in order to improve flavor, functionality, form, preservability, etc. Is not to be done.

  In the step (c) and the step (d), only one of the steps may be performed, or both steps may be performed. Further, the order of performing the steps (c) and (d) is not particularly limited as long as it is after the step (b), and any step may be performed first, and both steps are performed simultaneously. May be. As an example, FIG. 1 shows a schematic process diagram when the steps (c) and (d) are performed.

<< Second aspect >>
The second aspect of the present invention is a silica-containing food containing alkaline natural mineral water and silica derived from cereal rice husks (SiO ₂ ).
The alkaline natural mineral water in the second aspect is the same as the alkaline natural mineral water in the first aspect, and preferably contains a mineral component beneficial to the human body. The mineral component preferably contains at least one of hydrogen carbonate ions, metasilicate ions, calcium ions, sodium ions, chloride ions, sulfate ions, magnesium ions, and potassium ions. The alkaline natural mineral water is preferably weakly alkaline having a pH of about 8.0 to 8.2.
The silica from the cereal rice husks in the second embodiment is silica produced from cereal rice husks similar to the cereal rice husks in the first embodiment. The method for producing silica is not particularly limited, but for example, the method described as the first aspect is preferable.

《Third embodiment》
A third aspect of the present invention is a silica-containing food containing an alkaline component and silica derived from cereal husks (SiO ₂ ), wherein the silica is dispersed in a colloidal form.
The alkaline component in the third aspect is a component having a pH of 8.0 or higher, may be solid or liquid, and is contained in food, so does not contain any harmful component to the human body, or It is preferable that only a very delicate thing is included. The alkaline component may be the alkaline natural mineral water in the first aspect.

The silica derived from cereal rice husks in the third embodiment is silica produced from cereal rice husks similar to the cereal rice husks in the first embodiment.
The method for producing silica from cereal rice husks is not particularly limited. For example, a production method including the steps (a) and (b) of the first aspect is preferable.

The silica-containing food of the third aspect is characterized in that silica is dispersed in a colloidal form.
When silica is brought into contact with the liquid component, it is dispersed in the liquid component and becomes colloidal. Here, when an alkaline component is not a liquid, the said silica containing foodstuff can have another liquid component other than an alkaline component and a silica. Here, the other liquid component is not particularly limited as long as it can be used for food, and for example, natural water or the like is preferable.
Dispersion of silica in a colloidal state improves the dispersion stability of silica in a silica-containing food.

  The silica-containing food produced by the method for producing a silica-containing food of the first aspect of the present invention and the silica-containing food of the second and third aspects are particularly limited as long as they can be enjoyed. Instead, it may be a liquid or a solid.

  The method for producing a silica-containing food and the silica-containing food of the present invention are very useful in the field of food production.

Claims (8)

(A) baked grain husk at 500 to 800 ° C. to obtain rice husk ash;
(B) adding and mixing alkaline natural mineral spring water to the obtained rice husk ash;
A method for producing a silica-containing food comprising: In the step (b), alkaline natural mineral water containing at least one of hydrogen carbonate ion, metasilicate ion, calcium ion, sodium ion, chloride ion, sulfate ion, magnesium ion and potassium ion is mixed with silica. The manufacturing method of the silica containing foodstuff of Claim 1 . The said (b) process is a manufacturing method of the silica containing foodstuff of Claim 1 or 2 further including the process of adjusting natural mineral spring water to weak alkalinity of pH 8.0-8.2. The method for producing a silica-containing food according to any one of claims 1 to 3 , wherein the rice husk is pulverized by a pulverizer (mill). further,
(C) adjusting the pH and / or silica concentration of the mixture produced in the step (b),
The manufacturing method of the silica containing foodstuff as described in any one of Claims 1-4 provided with these. further,
(D) a step of adding a food additive derived from a natural product, at least one food additive of a food pigment, a nutritional supplement material, a taste control material, or a mineral component, to the mixed solution generated in the step (b),
The manufacturing method of the silica containing foodstuff as described in any one of Claims 1-5 provided with these. The method for producing a silica-containing food according to any one of claims 1 to 6 , wherein the rice husk is washed by a reflux method using dilute hydrochloric acid. The method for producing a silica-containing food according to any one of claims 1 to 7 , wherein the rice husk is dried with warm air and / or sunlight.

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