JP2012214452A - Method for producing antioxidant composition and health food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for effectively producing an extremely high effective antioxidant composition from rice bran, and to provide a health hood containing the antioxidant composition obtained by the method.SOLUTION: The method for producing the antioxidant composition includes a step of treating an aqueous dispersion of rice bran by heating at over 100°C and a step of treating the heat-treated rice bran by enzymatic treatment with pectinase and mannanase.

Description

  The present invention relates to a method for producing a composition having an antioxidant action, and a health food containing an antioxidant composition obtained by the method.

  Rice has long been used as a staple food in Japan, and since the Edo period, polished rice has been established to improve flavor. Rice bran produced in large quantities by milled rice is difficult to preserve for a long time due to its oil component, and in the old days it was only used slightly as a pickle bed or feed. Even now, they are also used as dredging beds, feeds, shimeji mushrooms, etc., mainly as a raw material for rice oil, but their use value is not high and they are discarded. There are many cases.

However, rice bran mainly consists of ectosperm that stores nutrients, a paste layer containing stored proteins, and germ to be sprouted, and contains very useful ingredients. For example, it is well known that beriberi, once said to be a national illness, is caused by a deficiency in vitamin B ₁ (thiamine), and that vitamin B ₁ , a specific medicine for beriberi, is contained in rice bran.

  In recent years, research on rice bran has further progressed, and rice bran contains useful substances such as γ-aminobutyric acid, which is a neurotransmitter, and ferulic acid and its ester, γ-oryzanol, which exhibit antioxidant activity. It has been revealed. Then, the utilization as a supplement or a health food is examined (patent document 1).

  Furthermore, methods for obtaining useful compounds and compositions using rice bran as a raw material have been studied. For example, Patent Documents 2 to 3 disclose methods for obtaining an antioxidant composition from rice bran using subcritical water or subcritical ethanol.

  Patent Document 4 describes an oil containing oryzanol at a high concentration obtained by extraction and purification from rice oil produced from rice bran. In Patent Document 5, after pressurizing rice bran, etc., it is treated with cellulase, hemicellulase, etc., ferulic acid is extracted with ethyl acetate, and arabinoxylan, which is said to have anticancer activity, is obtained from the remaining liquid. A method is disclosed.

  In recent years, attention has been focused on antioxidant substances derived from rice bran, such as ferulic acid and oryzanol, as health-consciousness has increased. Antioxidants neutralize peroxides, which are said to cause aging, arteriosclerosis, etc., and alleviate the progression of aging and lifestyle-related diseases. There are various kinds of antioxidants, and some of them are harmful to living organisms, but if they are derived from rice bran used for food and food production, they are safe and can be used as health foods. I can expect.

JP 2007-68523 A JP 2006-160825 A JP 2007-223990 A JP 2007-124917 A Special Table 2003-526355

  As described above, rice bran contains various active ingredients. As such active ingredients, compounds exhibiting an antioxidative action such as ferulic acid and oryzanol are known. Moreover, an unknown active ingredient may be contained. However, the antioxidant action of antioxidant substances and antioxidant compositions obtained from rice bran by conventional methods is not always satisfactory.

  Then, this invention aims at providing the health food containing the antioxidant composition obtained by the method which can manufacture an extremely effective antioxidant composition from rice bran efficiently, and the said method.

  The present inventors have intensively studied to solve the above problems. As a result, if the rice bran aqueous dispersion was heat-treated above 100 ° C. and then treated with a specific enzyme combination, it was extremely excellent that could not be explained only by the antioxidant effect of ferulic acid contained in the treated composition. The present invention was completed by finding that a composition exhibiting an antioxidant action can be easily produced.

  The method for producing an antioxidant composition according to the present invention includes a step of heat-treating an aqueous dispersion of rice bran above 100 ° C., and a step of enzymatically treating the heat-treated rice bran with pectinase and mannanase. And

  In the method of the present invention, it is preferable that the rice bran after the heat treatment step is further subjected to an enzyme treatment with cellulase. Probably, it is considered that cellulose, which is the main structure of the cell wall, is decomposed to release an antioxidant substance in the cell wall, but the antioxidant treatment of the resulting composition is further improved by the enzyme treatment.

  The heating temperature of the rice bran aqueous dispersion is preferably 115 ° C. or higher. It has been confirmed by the experimental findings of the present inventors that a composition exhibiting an excellent antioxidant action in such a temperature range can be produced more efficiently.

  In the method of the present invention, it is preferable to carry out a step of obtaining a solution by solid-liquid separation after the enzyme treatment. Since the said solution shows the outstanding antioxidant effect, it is thought that the antioxidant substance is contained.

  In the method of the present invention, it is preferable to carry out a step of degreasing rice bran before the heat treatment step. The rice bran component contains a relatively large amount of oil component, and such an oil component may possibly inhibit the enzyme reaction. Moreover, since the antioxidant substance which concerns on this invention is water-soluble, it can be said that an oil component is an impurity. Therefore, it is for reducing the content of the oil component in advance.

  As a degreasing method, pressure degreasing is preferable. Extraction using an organic solvent such as hexane can be adopted as a method for degreasing rice bran, but pressure degreasing is more preferable because of the possibility of harm caused by residual organic solvent.

  The health food according to the present invention includes an antioxidant composition produced by the method of the present invention.

  In recent years, with an increase in health consciousness, there is a demand for antioxidant substances and antioxidant compositions that are suitable for safe and constant consumption. In this respect, the antioxidant composition produced by the method of the present invention is safe because it uses rice bran as a raw material, and can be ingested daily, and exhibits an excellent antioxidant effect. Moreover, according to the method of the present invention, such an antioxidant composition can be easily produced. Therefore, the present invention is very excellent in the industry as enabling the provision of safe and highly effective antioxidant compositions and health foods.

  Hereinafter, the method of the present invention will be described in the order of execution.

(1) Degreasing step In the method of the present invention, it is preferable to first degrease rice bran. The rice bran component contains about 18 to 19% of an oil component, and this oil component may possibly inhibit the enzyme reaction. Moreover, since the antioxidant substance which concerns on this invention is water-soluble, it can be said that an oil component is an impurity. Therefore, it is preferable to reduce the content of the oil component in advance by carrying out this step. However, the implementation of this step is optional, and this step may be omitted, and the rice bran obtained in the rice milling step may be directly applied to the subsequent steps.

  The raw material of the method of the present invention is rice bran.

  Rice bran is produced in the rice milling process of brown rice, and can be obtained by red rice bran obtained up to about 90% of the milled rice, medium rice bran obtained up to about 85%, white rice bran obtained up to about 75%, and further polished rice. It is classified as special or special white. Rice bran is mainly composed of brown endosperm, paste layer, and germ. The higher the milling ratio, the greater the percentage of endosperm and the whiteness. In the present invention, the type of rice bran used as a raw material is not particularly limited, and any type of rice bran or a mixture thereof can be used, but red rice bran is preferably used. Red cocoon has a small proportion of endosperm but a relatively large proportion of ectosperm, paste layer, and germ, and the antioxidant substance, which is an important component for the present invention, is more in ectoderm, not in endosperm. It is thought that it is included.

  The degreasing method is not particularly limited and may be appropriately selected. Examples of the degreasing method include extraction with an organic solvent, heating and subsequent cooling, and pressurization. Of these methods, the degreasing method by pressurization is most preferable.

  In extraction with an organic solvent, rice bran is immersed in an organic solvent to extract oil, and then solid-liquid separation is performed, and the rice bran is dried. As the organic solvent used here, hexane, acetone, or the like can be used. The amount of the organic solvent used may be such that the rice bran is sufficiently immersed, and the extraction time is not particularly limited and may be such that the oil in the rice bran is sufficiently extracted. The time can be set to about 5 hours or less. Further, during extraction, a mixture of rice bran and an organic solvent may be stirred or shaken. Then, after solid-liquid separation by filtration or centrifugation, the defatted rice bran may be dried. In drying, the pressure may be reduced.

  The rice bran can be degreased by heating the rice bran and then cooling it if necessary to separate the exuded oil. A conventional method can be used as a means for separating the exuded oil, but since the oil is viscous and the amount thereof is not so large that normal filtration can be applied, it is preferable to use centrifugal separation or vacuum filtration. Centrifugation is more preferred.

  Degreasing by pressurization is preferable because it can be easily carried out using a pressing machine, and there is no fear of residual harmful organic solvent, and the degreasing efficiency is higher than other methods.

  Before performing the pressure degreasing, it is preferable to heat the rice bran at about 90 ° C. or higher and about 120 ° C. or lower in order to further improve the degreasing efficiency. Moreover, as a pressing machine which should perform pressure degreasing, the general thing according to the implementation scale etc. can be used.

  It is preferable that the oil content (lipid) in the resulting rice bran is about 5% by mass or more and 15% by mass or less by this process. If the said ratio is 15 mass% or less, it can be said that oil content was fully removed to such an extent that implementation and efficiency of a subsequent process are not impaired. On the other hand, if the oil content is excessively removed, the efficiency of the entire method of the present invention may be lowered. Therefore, the proportion is preferably 5% by mass or more. As the said ratio, 14 mass% or less is more preferable, and 12 mass% or less is further more preferable.

(2) Powdering process It is preferable that rice bran is powdered in advance. By making it into powder, the efficiency of the subsequent steps can be further increased. However, rice bran is originally sufficiently fine, and normally, the active ingredient can be separated without going through the step, so the step is optional and not necessarily performed.

  For pulverization, a normal grinding machine such as a ball mill, a bead mill, a roll mill, a hammer mill, or a cyclone mill can be used. The degree of pulverization is not particularly limited. For example, the volume average particle diameter determined from the particle size distribution measured by a general particle size distribution meter may be about 1 μm or more and 200 μm or less. If the volume average particle size is 200 μm or less, the subsequent steps can be carried out sufficiently efficiently. On the other hand, since the efficiency of the entire method of the present invention may be lowered if it is attempted to be excessively fine, the volume average particle diameter is preferably 1 μm or more. The average particle diameter is more preferably 5 μm or more, further preferably 10 μm or more, more preferably 100 μm or less, further preferably 80 μm or less, and further preferably 50 μm or less.

  This step is optional and may be performed before or after the degreasing step. However, since oil may ooze out depending on the powdering means, the powdering step is preferably performed after the degreasing step is performed first. Furthermore, the powdering step can be performed after the heating step described below.

(3) Heating process In the said process, it heats, after disperse | distributing the rice bran which passed through the said degreasing process and / or powdering process, or an untreated rice bran in water. According to the experimental findings by the present inventors, a composition having an extremely excellent antioxidation effect can be efficiently produced by going through this step and a specific enzyme treatment step described later. The reason for this is not always clear, but it is likely that the process physically destroys at least a part of the cellular tissue to increase the efficiency of the subsequent enzymatic reaction, or to facilitate the release of useful antioxidants. It is thought that there is.

  In this step, the purpose is to physically decompose at least a part of the cellular tissue. According to the experimental findings by the present inventors, when the rice bran is not only heated but also dispersed in water to form a dispersion and heated, an effective antioxidant composition can be produced efficiently. Can do.

  The rice bran used here can be a rice bran that has undergone a degreasing process and / or a powdering process, or an untreated rice bran. The water used for the preparation of the dispersion is not particularly limited, and purified water, distilled water, RO water, pure water, ultrapure water, tap water, well water, and the like can be used. Water or well water may be used.

  The rice bran concentration in the dispersion may be adjusted as appropriate, and can be, for example, about 0.5% by mass or more and 40% by mass or less with respect to the obtained dispersion (total of rice bran and water). If the proportion is 40% by mass or less, the amount of water can be said to be sufficient, but if the amount of water is too large, the concentration of the finally obtained antioxidant may be excessively lowered. The proportion is preferably 0.5% by mass or more. As the said ratio, 1 mass% or more is more preferable, and 30 mass% or less is more preferable.

  The heating temperature is over 100 ° C. so that the cell tissue is sufficiently decomposed. Below 100 ° C., the cell tissue is not sufficiently decomposed, the production efficiency of the antioxidant composition is lowered, and a composition having a sufficiently satisfactory antioxidant power cannot be obtained. The heating temperature is preferably 105 ° C. or higher, more preferably 115 ° C. or higher, and further preferably 120 ° C. or higher. On the other hand, if the temperature is excessively increased, large-scale implementation may be difficult, and the flavor may be lowered or useful components may be decomposed. Therefore, the temperature is preferably 200 ° C. or lower. More preferably, it is 150 degrees C or less, More preferably, it is 140 degrees C or less. In order to prevent the evaporation of moisture during heating, it is necessary to heat in a closed system. Furthermore, in order to set the heating temperature to over 100 ° C., it is preferable to heat under pressure.

  The heating time is not particularly limited and may be appropriately adjusted. For example, the heating time may be 30 seconds or longer and 10 hours or shorter. If it is 30 seconds or more, the cell wall can be more reliably decomposed. On the other hand, if the heating time is too long, the active ingredient may be decomposed. Therefore, the heating time is preferably 10 hours or less. The heating time is preferably 5 minutes or more, more preferably 10 minutes or more, further preferably 30 minutes or more, particularly preferably 1 hour or more, more preferably 8 hours or less, still more preferably 6 hours or less, 4 The time is further preferably 3 hours or less.

  After heating, it is preferable that the dispersion is allowed to cool and then cooled to room temperature. After this step, the dispersion can be used as it is in the next step.

  Although it does not restrict | limit especially as a heating means, For example, as a device which can be heated more than 100 degreeC, a retort sterilizer, a super-high temperature instant sterilizer, a plate type heater, a scraping type heater, a tube type heater, micro Examples thereof include a wave heater and a Joule heater.

(4) Enzyme treatment step Next, the heat-treated rice bran dispersion is subjected to an enzyme treatment with pectinase and mannanase.

  In the present invention, a cellulase for decomposing cellulose may be further used.

  In the said process, since the active ingredient may have melt | dissolved in water at the heat processing process, it is preferable to use the dispersion liquid which passed through the heat processing process as it is.

  What is necessary is just to adjust the usage-amount of said each enzyme, pH, reaction temperature, reaction time, etc. suitably. Each enzyme reaction may be performed sequentially or at a time. That is, after adding one of the enzymes and reacting under the optimal reaction conditions according to the enzyme, repeat the operation of adding the next enzyme and performing the reaction under the optimal reaction conditions according to the enzyme. Alternatively, the reaction may be performed by adding all the enzymes and adjusting the conditions so that all the enzymes are active. Note that the embodiment in which the enzyme reaction is performed at a time may reduce the enzyme reaction efficiency to some extent, but is suitable for industrial mass production because the total reaction time can be shortened.

(5) Solid-liquid separation process Since the obtained enzyme treatment liquid shows an antioxidant action, it can be drunk as it is. However, since the antioxidant substance according to the present invention is water-soluble and is considered to be dissolved in the enzyme treatment solution, it is preferable to perform solid-liquid separation. However, this step is optional.

  The solid-liquid separation means is not particularly limited, and for example, filtration, centrifugation, decantation after standing, etc. can be used.

(6) Purification step After the enzyme treatment step, after further solid-liquid separation, or without solid-liquid separation, purification may be further advanced for commercialization.

  For example, the antioxidant substance may be purified by appropriately selecting or combining purification means such as water removal, extraction, salting out, chromatography, recrystallization and the like.

  Since the antioxidant composition obtained by the above-described method of the present invention is derived from rice bran that can be edible, it is safe and can be ingested constantly, and exhibits an excellent antioxidant effect. Cardiovascular diseases such as dyslipidemia and arteriosclerosis; aging; cancer; neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease; diabetes and diabetic complications; can be used as a health food that can be expected to prevent rheumatoid arthritis is there.

  The antioxidant composition according to the present invention contains ferulic acid, which is known as an antioxidant substance, and exhibits a much higher antioxidant effect than that considered to be due to ferulic acid alone. Therefore, it is considered that some excellent antioxidant substance is included in addition to ferulic acid.

  The antioxidant composition according to the present invention can be made into oral compositions such as health foods by adding general additive components. Examples of dosage forms of such oral compositions include liquids, syrups, beverages, tablets, capsules, powders, granules, bars, jelly, etc. Beverages, tablets, powders, and granules are preferred. Examples of the additive component include a base, an excipient, a colorant, a lubricant, a corrigent, an emulsifier, a thickener, a wetting agent, a stabilizer, a preservative, a solvent, a solubilizing agent, and a suspending agent. Agents, antioxidants, adjuvants, buffers, pH adjusters, sweeteners, flavors and the like. The blending amount of these additives can be appropriately set as necessary as long as it does not interfere with the antioxidant action of the present invention.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

Example 1
Red rice cake obtained by refining brown rice (produced in Japan) at a polishing rate of 90% was heated to 103 to 110 ° C., and then defatted by pressing with a continuous press (Techno Sigma, Miracle Chamber). It was 13.5 mass% when the lipid content contained in the obtained defatted rice bran was measured by the diethyl ether extraction method. The defatted rice bran was pulverized and classified by an airflow pulverizer (manufactured by Masuno Seisakusho Co., Ltd., New Microcyclomat), so that the volume average particle size determined from the particle size distribution was 50 μm.

  The defatted rice bran particles were dispersed in tap water to give a 5% by mass dispersion. The dispersion was heat-treated at 121 ° C. for 15 minutes using an autoclave. After cooling to room temperature, the pH of the dispersion was adjusted to 5.0 using a 25% by mass aqueous citric acid solution.

  0.1 mass% of each enzyme shown in Table 1 was added to the dispersion (30 mL), the temperature of the reaction apparatus was set to 50 ° C., and the mixture was stirred at a dispersion temperature of 43 ° C. for 20 hours. Next, each dispersion was centrifuged to obtain a supernatant.

Test Example 1 Measurement of Ferulic Acid Content Each enzyme-treated solution of Example 1 was put in a small amount of a Falcon tube before centrifugation and sufficiently stirred using a vortex mixer. Next, 1 g of the stirred sample was weighed and placed in a 20 mL volumetric flask, and a mixed solution of water: methanol = 50: 50 was added to make up to 20 mL. The obtained diluted sample was centrifuged at 12000 rpm for 10 minutes to obtain a supernatant. The concentration of ferulic acid contained in the obtained supernatant was measured by HPLC under the following conditions. The results are shown in Table 2.
Column: Cosmosil 5C18 MS-II 4.6 mm × 150 mm
Apparatus: Agilent HP1100 apparatus 3 system Mobile phase: 0.5% acetic acid: acetonitrile = 88: 12
Flow rate: 1.0 mL / min
Measurement wavelength: UV320nm
Sample injection volume: 20 μL
Column temperature: 40 ° C

Test Example 2 Antioxidant Test Antioxidant activity of each enzyme-treated solution was tested using an antioxidant activity measurement kit (OxiSelect ^™ Oxygen Radical Antioxidant Activity Assay manufactured by CELL BIOLABS). Specifically, the supernatant obtained in Example 1 was heated at 65 ° C. for about 30 minutes, and then diluted 1000-fold with Assay Diluent included in the kit. The diluted solution and a 0-50 μM solution of antioxidant standard (Trolox, vitamin E-like substance) attached to the kit were added to separate wells of the microplate at 25 μL / well. Moreover, the dye (fluorescein) attached to the kit was diluted 1: 100 with Assay Diluent, and added to the microplate at 150 μL / well. After mixing well, it was incubated at 37 ° C. for 30 minutes. Next, Free Radial Initiator included in the kit was dissolved in PBS to make an 80 mg / mL solution, and added to the microplate at 25 μL / well. Fluorescence is measured with a fluorescence plate reader (Ex .: 480 nm, Em .: 520 nm) every 3 minutes for 1 hour immediately after mixing using the tip of the micropipette. Curve of the measured fluorescence amount graph The bottom area (AUC) was calculated. A calibration curve was prepared from each concentration of the antioxidant standard product (Trolox, vitamin E-like substance) and the area under the curve, and the antioxidant activity (ORAC value) of each enzyme treatment solution was determined from the calibration curve.

  In addition, in order to investigate the effect of ferulic acid, which is conventionally known as an antioxidant, after adding ferulic acid at the concentration measured in Test Example 1 to the sample before enzyme treatment in Example 1 above. Similarly, the antioxidant activity (ORAC value) was determined. The results are shown in Table 2.

  As shown above, cellulase that decomposes cellulose, pectinase that cleaves 1,4-bond of polygalacturonic acid that constitutes pectin, and rice bran that has been heat-treated with mannanase that decomposes glucomannan, a kind of hemicellulose, are enzymatically treated. Even in this case, an antioxidant effect is observed (Experimental Examples 2 to 4). Antioxidant action can be seen even without enzyme treatment (Experimental Example 1). This is due to the antioxidant substance originally contained in rice bran in a free state and the cell wall by heat treatment above 100 ° C. It is thought to be due to antioxidant substances released from the cytoplasm.

  On the other hand, in addition to the heat treatment above 100 ° C., when the enzyme treatment is performed by combining pectinase and mannanase, the antioxidant effect far superior to the case where each of the above enzymes is used alone is exhibited. (Experimental example 5). When cellulase was used in addition to pectinase and mannanase, the antioxidant effect was further improved (Experimental Example 6).

  The antioxidant activity was measured even when ferulic acid at a concentration contained in the enzyme treatment solution was added to the non-enzyme treatment solution, but compared to the ORAC value of the non-enzyme treatment solution (Experimental Example 1) to which ferulic acid was not added. There is no such improvement effect. More specifically, in Experimental Examples 2 to 4, when the ORAC value when ferulic acid is added to the non-enzyme-treated solution is reduced from the ORAC value after the enzyme treatment, approximately Experimental Example 1 (in the case of only heat treatment and no enzyme treatment) ) Or less than or equal to the ORAC value. Therefore, it can be seen that in Experimental Examples 2 to 4, the effect of antioxidant substances other than ferulic acid is hardly obtained. On the other hand, in Experimental Examples 5 to 6, the value obtained by subtracting the ORAC value when ferulic acid is added to the non-enzymatic treatment solution from the ORAC value after the enzyme treatment is clearly larger than the ORAC value in Experimental Example 1. Therefore, it is concluded that the antioxidant effect of the enzyme treatment solution obtained when pectinase and mannanase are used in combination is not derived solely from ferulic acid but mainly due to the antioxidant activity of other substances. It was.

Test Example 3 Confirmation Test of Enzymatic Reaction First, after 5 mass% rice bran dispersion was heat-treated at 121 ° C. for 15 minutes as in Example 1, the concentration of monosaccharide to pentasaccharide contained in the solution portion was measured by HPLC. It was measured. Further, after the same heat treatment, the enzyme treatment was carried out under the same conditions as in Example 1 except that 0.1% by mass of pectinase, mannanase, cellulase and chlorogenic acid esterase was used. Subsequently, the density | concentration of the monosaccharide-pentasaccharide contained in a solution part was measured on the same conditions. The results are shown in Table 3. In addition, “-” in Table 3 indicates that measurement was not performed.

  As described above, the monosaccharide concentration is relatively low when the rice bran dispersion is only heat-treated. In addition, it is thought that the detected fructose and glucose were produced when sucrose was hydrolyzed. On the other hand, when enzyme treatment was performed in addition to heat treatment, not only fructose and glucose, but also monosaccharides, particularly arabinose and xylose, which were not detected by heat treatment alone, were detected. The reason is considered that the decomposition of the polysaccharide contained in the cell tissue was promoted by the combination of the heat treatment and the enzyme treatment, and the composition of the composition was obtained by the combination of the heat treatment and the enzyme treatment as in Test Example 2 above. The reason why the antioxidant ability was remarkably improved is considered to be that the antioxidant contained therein was released by the decomposition of the cell tissue.

Example 2
A commercially available semi-defatted rice bran powder (manufactured by Sanwa Oil & Fats Co., Ltd., product name “Hybref”) was dispersed in tap water to obtain a 5 mass% dispersion. The dispersion (about 500 g) was heated at 121 ° C. or 130 ° C. using an autoclave (manufactured by Tommy Seiko). Or after boiling at 100 degreeC, the water for the transpiration was added.

  To the dispersion (30 mL), pectinase, mannanase, cellulase and chlorogenic acid esterase were added in an amount of 0.1% by mass and stirred at pH 5.0 and 50 ° C. for 20 hours. Next, each dispersion was centrifuged to obtain a supernatant.

  The concentration of ferulic acid contained in the obtained supernatant was measured under the same conditions as in Test Example 1 except that the centrifugation conditions were changed to 13000 rpm for 3 minutes. The results are shown in Table 4. In addition, F value in Table 4 shows the standard of the sterilization conditions corresponding to each heating condition.

  As described above, when the heating temperature of the rice bran dispersion was 100 ° C., the release rate of ferulic acid, which is one of the antioxidant indexes, was about 50%, which was not sufficient. On the other hand, when the heating temperature exceeds 100 ° C., the ferulic acid liberation rate can be clearly improved.

Example 3
In actual mass production, the heating temperature is limited. Therefore, further experiments were conducted on the heating temperature and heating time of the rice bran dispersion. Specifically, a 300-liter culture tank (manufactured by Maruhishi Bioengine, maximum allowable temperature: 130 ° C.) or a 600-liter culture tank (manufactured by ITOCHU FUDEC Co., Ltd., maximum allowable temperature: 130 ° C.) used for lactic acid fermentation or the like is used. 250-270 L or 550-570 L of 5% by mass rice bran dispersion was treated under the conditions shown in Table 5, and then the enzyme reaction and ferulic acid concentration were measured under the same conditions as in Example 2 above. Moreover, the p-coumaric acid density | concentration which becomes an antioxidant parameter | index similarly on the same conditions was measured. The results are shown in Table 5.

  As described above, by raising the heating temperature to 125 ° C., it became possible to achieve a ferulic acid liberation rate of 75% or more that is sufficiently suitable for mass production.

Claims (7)

A method for producing a composition having an antioxidant action,
A process comprising the steps of: heat-treating an aqueous dispersion of rice bran at a temperature exceeding 100 ° C .; and subjecting the heat-treated rice bran to an enzyme treatment with pectinase and mannanase.   Furthermore, the manufacturing method of Claim 1 which enzyme-processes with a cellulase.   The manufacturing method of Claim 1 or 2 which heat-processes the aqueous dispersion of rice bran at 115 degreeC or more.   Furthermore, the manufacturing method in any one of Claims 1-3 including the process of solid-liquid separating and obtaining a solution after an enzyme treatment.   The manufacturing method in any one of Claims 1-4 including the process of degreasing rice bran before a heat processing process.   The manufacturing method of Claim 5 which degreases rice bran by pressurization.   A health food comprising the antioxidant composition produced by the method according to claim 1.