JP6170331B2 - Production method of fine bran - Google Patents

Description

  The present invention relates to a method for producing fine powdered bran, which is a pulverized product of wheat bran, and in particular, relates to a method for producing finely powdered bran containing a high amount of alkylresorcinol which has recently attracted attention as a functional material.

  In recent years, the demand for wheat bran rich in nutrients such as dietary fiber, vitamins, and minerals has increased due to an increase in health consciousness, and various techniques relating to the effective use of wheat bran have been proposed accordingly. For example, in Patent Document 1, as a method for collecting a specific fraction rich in various nutrients (a fraction of paste cell particles and pericarp-seed coat particles) from wheat bran, a particle size of about 40 μm is obtained from a pulverized product of wheat bran. A method is described in which a fraction of small particles is removed, the remaining fraction (a fraction having a particle size of more than about 40 μm) is electrostatically charged, and the specific fraction is collected by the difference in charge. In Patent Document 2, wheat bran is pulverized to a particle size of 500 μm or less, fine particles having a particle size of 30 μm or less are removed from the pulverized product, and the remaining fraction (fraction having a particle size of more than 30 μm) is subjected to air classification. Unnecessary fractions are classified and removed, and the remaining fractions are divided into a high protein fraction (a fraction with a particle size of 95 ± 25 μm or less) and a high dietary fiber fraction (a fraction with a particle size greater than 95 ± 25 μm). And a method for separating them.

  In addition, it is well known that alkylresorcinol has an anti-obesity action, an antioxidant action, an anti-immunity action and the like. Non-Patent Document 1 describes that alkylresorcinol is widely contained in plants as a resorcinol lipid that is a natural non-isoterpenoid phenolic amphiphilic compound, and a plant that is a source of resorcinol lipid. As mentioned above, gramineous plants such as wheat are described. Non-Patent Document 2 describes that a large amount of alkylresorcinol is particularly contained in wheat and rye among plants. Patent Documents 1 and 2 do not describe alkylresorcinol.

JP 61-501829 A Japanese Patent Laid-Open No. 1-206962

Chemical Reviews (1999), Vol.99, No.1, pp.1-25, Arkadiusz Kozubek et al. Nutrition Reviews (2004), Vol.62, NO.3, pp.82-95, Alastair B. Ross et al.

  The present invention relates to a method for producing finely powdered bran, which contains a high content of alkylresorcinol and is useful as a food material.

As a result of intensive studies, the present inventors classified a particle fraction having a median diameter of 50 μm or more from a pulverized product of wheat bran (fine powder bran fraction having a median diameter of 200 μm or less) obtained through the following steps 1 to 5. It was found that alkylresorcinol was highly contained in the fine particle fraction having a median diameter of less than 50 μm.
Step 1: Rolling the raw material wheat to obtain a coarsely pulverized product.
Step 2: A step of collecting wheat bran from the coarsely pulverized product.
-Process 3: The process of wet-heat-treating the said wheat bran.
Step 4: A step of pulverizing the wet heat-treated wheat bran obtained by the wet heat treatment to obtain a finely pulverized product.
Step 5: A step of classifying the finely pulverized product into a fine powder bran fraction having a median diameter of 200 μm or less and other fractions, and collecting the fine powder bran fraction.

  The present invention has been made on the basis of the above-mentioned knowledge, and classifies the wheat bran pulverized product into a fine particle fraction having a median diameter of less than 50 μm and other fractions, and collects the fine particle fraction. The manufacturing method of the fine powder bran which has this.

  ADVANTAGE OF THE INVENTION According to this invention, the fine powder bran which contains alkyl resorcinol highly and is useful as a foodstuff material can be manufactured efficiently. Since this fine powder bran has a higher content of alkylresorcinol than conventional wheat bran, it is useful as a food material that can efficiently ingest alkylresorcinol useful for the human body.

  The method for producing fine powder bran of the present invention uses a pulverized product of wheat bran as a starting material, classifies the pulverized product into a plurality of fractions based on the particle size, and a specific fraction (of which the particle size is relatively small). A step of collecting a fraction). Hereinafter, first, wheat bran pulverized material, which is a starting material of the production method of the present invention, will be described.

  Wheat bran, which is a raw material for pulverized wheat bran, is mainly composed of the outer skin of wheat grains. As wheat bran, the remainder obtained by removing the endosperm from the wheat grains, which is produced during the production process of general wheat flour, or the one obtained by further removing the germ from the remainder can be used, regardless of the composition or the production process. Moreover, the kind of wheat used as the raw material of wheat bran is not particularly limited.

  Wheat bran can be collected from a coarsely pulverized product obtained by pulverizing raw wheat. The method for pulverizing wheat is not particularly limited, and a known pulverization method can be appropriately used. Examples thereof include roll pulverization, impact pulverization, and airflow pulverization. In the present invention, one of these can be used alone or in combination of two or more. For example, roll pulverization and impact pulverization can be combined, and both can be carried out in this order. Moreover, the wheat pulverization by roll-type pulverization or the like may be performed once or multiple times in multiple stages. The pulverizer used for impact pulverization is not particularly limited as long as pulverization is performed between the impact plate and the rotating rotor by mechanical impact, and for example, a turbo mill, a blade mill, or the like can be used.

  In the production of wheat bran, before pulverizing wheat, the wheat may be hydrated and conditioned, but the wheat is usually pulverized without hydration / humidification. The method for collecting wheat bran from the coarsely pulverized product obtained by pulverizing wheat is not particularly limited. For example, the coarsely pulverized product is classified into wheat bran and other components by a known classification method such as sieving. A method of separating and collecting the wheat bran can be used.

  The pulverized wheat bran used in the present invention is obtained by pulverizing wheat bran. A method for pulverizing wheat bran is not particularly limited, and a known pulverization method can be used as appropriate. Examples thereof include roll-type pulverization, impact-type pulverization, and air-flow-type pulverization. In the present invention, one of these can be used alone. Or two or more can be used in combination.

  In the production of pulverized wheat bran, it is preferable to heat-treat the wheat bran before pulverizing the wheat bran. By heat-treating the wheat bran, the wheat bran is easily pulverized in the next step. The heat treatment of wheat bran may be dry heat treatment or wet heat treatment, but wet heat treatment is particularly preferable. Dry heat heating is a heat treatment in which a raw material (wheat flour bran) is placed in a container and heated from outside the container without adding moisture. Wet heat heating is a heat treatment performed while maintaining or adding moisture in the raw material (wheat flour bran), more specifically, a method of heating the raw material in the presence of water vapor or water, At this time, the raw material may be heated with water vapor or water itself.

  The particle size of the pulverized product of wheat bran used in the present invention is not particularly limited, but if the median diameter (D50) of the pulverized product is 200 μm or less, a high content of alkylresorcinol is contained in the subsequent classification step of the pulverized product. The fraction to be collected can be collected more reliably. The median diameter of the pulverized wheat bran used in the present invention is preferably 150 μm or less to 180 μm or less, and more preferably less than 150 μm. Adjustment of the particle size of the wheat bran pulverized product can be performed according to a conventional method using a sieve, an air classifier or the like.

  In the present invention, the median diameter (D50) means a particle diameter (volume median diameter) at which the cumulative volume frequency calculated by the volume fraction is 50% calculated from the smaller particle diameter. For example, the median diameter of 200 μm or less means that the particle diameter when the cumulative frequency of particles (wheat bran pulverized product) reaches 50% is 200 μm or less. The median diameter is obtained as a volume-based median diameter measured with a laser diffraction / scattering particle size distribution meter (trade name “Microtrack”, manufactured by Nikkiso Co., Ltd.).

  The manufacturing method which has the said process 1-5 is mentioned as an example of the manufacturing method of the pulverized material of wheat bran used by this invention. Since Steps 1 and 2 are as described above for the production of wheat bran, the following description supplements the other steps.

  In the step 3, the wet heat treatment of the wheat bran is preferably performed so as to deactivate or reduce the activity of various enzymes such as amylase and protease contained in the wheat bran. When the activity of the enzyme in wheat bran is deactivated or reduced, the secondary processability of wheat bran is improved, and the flavor and texture of the secondary processed product using the wheat bran are improved. As an example of a wet heat treatment of wheat bran, a method of performing a wet heat treatment of wheat bran for 1 to 60 seconds at a heating temperature of 80 to 110 ° C. and a heating time (wheat bran residence time) in a closed container into which water vapor is introduced. Is mentioned. In such a wet heat treatment method, the heating temperature is preferably 85 to 98 ° C, more preferably 90 to 95 ° C, and the heating time is preferably 5 to 30 seconds. Such a wet heat treatment method can be carried out using an apparatus described in Japanese Patent No. 2784505.

  In the step 4, impact pulverization is preferred as a method for pulverizing the wet heat-treated wheat bran. The degree of pulverization of the wet heat-treated wheat bran is 80 to 100% by mass, particularly 90 to 100% by mass, in the classification of the next step (said step 5), the proportion of the fine powder bran fraction having a median diameter of less than 150 μm to less than 200 μm. It is preferable to do so. In addition, when impact type pulverization is performed in the step 4 and classification in the next step 5 is performed by an air classifier, by using an impact type fine pulverizer with a built-in air classifier, the steps 4 and 5 can be performed. Can be performed almost simultaneously, which is advantageous in terms of equipment and cost. Examples of the impact type fine pulverizer with built-in air classifier include ACM pulverizer (trade name) manufactured by Hosokawa Micron.

  In the step 5, the finely pulverized product of the wet heat-treated wheat bran obtained in the step 4 is classified into a fine powder bran fraction having a median diameter of 200 μm or less and other fractions by classification with a sieve or classification with an air classifier. Classification into a fraction (crude bran fraction) (first classification step). The former fine powder bran fraction is used in the present invention, and this fine powder bran fraction is collected and used in a further classification step (second classification step) described later. The latter coarse bran fraction (the fraction of particles having a median diameter of more than 200 μm) is basically unnecessary and may be discarded, but can be returned to the step 4 and pulverized again.

  As one of the main characteristics of the production method of the present invention, the wheat bran pulverized product produced as described above is divided into “fine particle fraction with a median diameter (D50) of less than 50 μm” and “other fractions”. And a fraction of particles having a median diameter of 50 μm or more and collecting the fine particle fraction. When using the above-mentioned “fine powder bran fraction having a median diameter (D50) of 200 μm or less” as a pulverized product of wheat bran, a classification step (first classification step) used to obtain the fine powder bran fraction, and the fine powder Two types of classification steps, ie, a step of classifying the bran fraction into a fine particle fraction having a median diameter of less than 50 μm and another fraction (second classification step) are performed. The median diameter (D50) is as described above.

Classification (second classification step) for selecting “a fine particle fraction having a median diameter of less than 50 μm” from pulverized wheat bran can be performed using a known classification means such as a sieve or an air classifier. However, it is preferable to use an air classifier from the viewpoint of classification efficiency. The air classifier is a classifying means for placing powder in a gas flow and making use of the difference between the particle size and true specific gravity of the powder particles using airflow and centrifugal force. Specifically, the classification (second classification step) is preferably performed using a rotary air classifier as described in JP-A-59-4477. When classifying a “fine particle fraction with a median diameter of less than 50 μm” using this rotary air classifier, the classification rotor is rotated at 2,500 to 6,000 rpm, and the air volume is 0.5 to 3.0 m. It is preferable to carry out under the condition of ³ / min.

  In the classification (second classification step) for selecting “fine particle fraction having a median diameter of less than 50 μm” from the pulverized wheat bran, the classification may be performed once or multiple times in multiple stages. . The final collection in the present invention is a fine particle fraction having a median diameter of less than 50 μm, and other fractions (fractions of particles having a median diameter of 50 μm or more) are basically unnecessary. Yes, it may be discarded, but it can be returned to the step 4 and pulverized again.

  The fine particle fraction with a median diameter of less than 50 μm selected from the pulverized wheat bran contains a high content of alkylresorcinol useful for the human body and is useful as a food material. According to the knowledge of the present inventors, among the fine particle fractions having a median diameter of less than 50 μm, the fine particle fraction having a median diameter of 30 μm or less, in particular, the fine particle fraction having a median diameter of 15 μm or less contains alkylresorcinol. Since the rate is high, it is meaningful to separate these fractions from other fractions. That is, in the present invention, the pulverized wheat bran is classified into “a fine particle fraction having a median diameter of 30 μm or less” and “other fraction” (a fraction of particles having a median diameter of more than 30 μm). Alternatively, it can be classified into “a fine particle fraction having a median diameter of 15 μm or less” and “another fraction” (a fraction of particles having a median diameter of more than 15 μm). In the present invention, the “fine particle fraction having a median diameter of less than 50 μm” selected from the pulverized wheat bran can be classified into two or more fractions, each of which can be collected. The fine particle fraction having a diameter of 15 μm or less ”and the“ fine particle fraction having a median diameter of more than 15 μm and less than 50 μm ”can be classified and sorted. Thus, in the present invention, the “fine particle fraction having a median diameter of 30 μm or less” contained in wheat bran is recognized as an important component, whereas in the inventions described in Patent Documents 1 and 2, the fine particle fraction is It is removed as an unnecessary component, and the difference between the technical ideas of both inventions is clear from this point.

  The content of alkylresorcinol in ordinary commercially available wheat bran is about 0.3% by mass, although it varies depending on the type of raw wheat. On the other hand, the content of alkylresorcinol in the “fine particle fraction having a median diameter of less than 50 μm” obtained by the production method of the present invention is preferably 0.35% by mass or more, more preferably 0.5% by mass or more. Can be expected. The alkylresorcinol content of the “fine particle fraction with a median diameter of 30 μm or less” obtained by the production method of the present invention is preferably 0.4% by mass or more, more preferably 0.5% by mass or more. it can. The alkylresorcinol content of the “fine particle fraction having a median diameter of 15 μm or less” obtained by the production method of the present invention is preferably 0.5% by mass or more, more preferably 0.52% by mass or more. it can. Here, the “content ratio of alkylresorcinol” means the total value of the contents of each of the plurality of types when the wheat bran (fine particle fraction) contains a plurality of types of alkylresorcinol.

  The alkylresorcinol contained in the product obtained by carrying out the production method of the present invention (fine particle fraction having a median diameter of less than 50 μm) will be described. The product is preferably represented by the following general formula (I). One or more alkylresorcinols.

Regarding R ₁ in the general formula (I), examples of the saturated alkyl group having 15 to 25 carbon atoms include n-pentadecyl, n-heptadecyl, n-nonadecyl, n-henicosyl, n-tricosyl, n- Examples include linear ones such as pentacosyl and n-heptacosyl, and besides these, branched or cyclic ones may be used. Among these, a saturated alkyl group having 15 to 23 carbon atoms is preferable.

Moreover, regarding R ₁ in the general formula (I), examples of the unsaturated alkyl group having 15 to 25 carbon atoms include those corresponding to the saturated alkyl group having 15 to 25 carbon atoms. There is no restriction | limiting in particular in the number and position of the unsaturated bond contained in an unsaturated alkyl group.

In the general formula (I), R ₂ is preferably a hydrogen atom, and R ₁ is preferably bonded to R ₂ at the para position.

Specific examples of the alkyl resorcinol that can be contained in the resulting product of the present invention (fine particle fraction having a median diameter of less than 50 μm) include the following.
1,3-dihydroxy-5-n-pentadecylbenzene (C15: 0)
1,3-dihydroxy-5-n-heptadecylbenzene (C17: 0)
1,3-dihydroxy-5-n-nonadecylbenzene (C19: 0)
1,3-dihydroxy-5-n-henicosylbenzene (C21: 0)
1,3-dihydroxy-5-n-tricosylbenzene (C23: 0)
1,3-dihydroxy-5-n-pentacosylbenzene (C25: 0)

  The resulting product of the present invention (fine particle fraction having a median diameter of less than 50 μm) can be used as a food material in the same manner as ordinary commercially available wheat bran. This food material includes not only food and drink for humans but also animal feed.

  EXAMPLES Hereinafter, although an Example manufacture example is given and this invention is demonstrated further in detail, this invention is not restrict | limited by this Example manufacture example.

[Example of production]
Commercially available wheat bran pulverized products were classified into “fraction with a median diameter of 15 μm” (fraction 1), “fraction with a median diameter of 50 μm” (fraction 2), “fraction with a median diameter of 117 μm” (fraction Fractions were classified into four fractions, ie, fraction 3) and “fraction having a median diameter of 220 μm” (fraction 4). The median diameter (D50) of the pulverized product of this commercially available wheat bran was 77 μm. Specifically, the classification of each pulverized product of wheat bran and the fractionation in the production examples were carried out as follows.

First, crushed wheat bran having a median diameter of 77 μm is supplied to a rotary air classifier (Turbo Classifier TC-15, manufactured by Nissin Engineering Co., Ltd.) at a rate of 2.0 kg / hour, and 3100 rpm. The classification rotor was rotated, and classification was performed under the condition of an air volume of 2.5 m ³ / min to obtain fine powder I and coarse powder I having a larger particle diameter than fine powder I. Fine powder I is fraction 1. Next, the coarse powder I is supplied to the rotary air classifier at a rate of 2.4 kg / hour, the classification rotor is rotated at 1600 rpm, and classification is performed under the condition of an air volume of 2.5 m ³ / min. Fine powder II and coarse powder II having a particle size larger than that of fine powder II were obtained. Fine powder II is the fraction 2. A mixture of fine powder I (fraction 1) and fine powder II (fraction 2) obtained in this way is a “fine particle fraction having a median diameter of less than 50 μm”. Next, coarse powder II is supplied to a classifier (low tap shaker, manufactured by Terraoka Co., Ltd., the interval between sieve meshes is set to 149 μm), and fine powder III and coarse powder III having a particle size larger than fine powder III are obtained. Obtained. Fine powder III is the fraction 3 and coarse powder III is the fraction 4.

〔Evaluation test〕
About each of the pulverized product and fractions 1 to 4 of the above-mentioned commercially available wheat bran, the alkylresorcinol represented by the general formula (I) and the contents of ash, protein and lipid were measured. The content of alkylresorcinol is measured by the following method, and the content of ash is measured according to the method disclosed in P86-89 of “5th edition, Japan Food Analysis Center / Editing” Was measured according to the method disclosed in P29 to 36 of the same description, and the lipid content was measured according to the method disclosed in P37 to 61 of the same description. The results are shown in Table 1 below.

<Measurement method of alkylresorcinol content>
Add 5 times the amount of ethanol to the object to be measured, extract under stirring at 600 rpm and room temperature for 16 hours, filter the extract to remove unnecessary substances, collect the ethanol extract, and then evaporate the ethanol. To obtain an ethanol extract. Methanol is added to the ethanol extract to prepare a methanol addition solution having a concentration of the ethanol extract of 200 ug / ml, and the methanol addition solution is passed through a filter having a pore size of 0.45 μm. A sample for liquid chromatography (HPLC) is used. HPLC conditions are as follows. A peak component appearing 31 to 36 minutes after the start of elution is collected and the solvent is distilled off to obtain alkylresorcinol. The target alkylresorcinol content is calculated from the total mass of the alkylresorcinol thus obtained and the total mass of the measurement object.
(HPLC conditions)
Column: silica gel (ODS-80A, 5 μm, 4.6 × 250 mm, manufactured by GL Sciences Inc.)
Guard column: ODS-80A, 5 μm, 4.6 × 50 mm,
-Column temperature: 30 ° C
-Mobile phase: 100% methanol
・ Detection wavelength: 215 nm

  As is clear from Table 1, fraction 1 (fraction with a median diameter of 15 μm) and fraction 2 (fraction with a median diameter of 50 μm) are equal to or higher than the ground wheat bran before classification. It has an alkylresorcinol content. Since the wheat bran pulverized product and the fractions 1 to 4 classified from now on have different compositions (contents of ash, protein and lipid), each fraction is simply finely pulverized. It is not the one that has been released (in terms of composition, the same substance as the pulverized product), but is another substance that is also different in composition. From the above, the fine particle fraction (mixture of fraction 1 and fraction 2) with a median diameter of less than 50 μm classified and collected from pulverized wheat bran contains a high content of alkylresorcinol useful for the human body. It turns out that it is useful as a food material.

Claims (3)

The finely divided bran fraction having a median diameter of 200 μm or less obtained through the following steps 1 to 5 is classified into a fine particle fraction having a median diameter of 15 μm or less and other fractions, and the fine particle fraction is classified into A method for producing fine powder bran, comprising a step of collecting.
Step 1: Rolling the raw material wheat to obtain a coarsely pulverized product.
Step 2: A step of collecting wheat bran from the coarsely pulverized product.
-Process 3: The process of wet-heat-treating the said wheat bran.
Step 4: A step of pulverizing the wet heat-treated wheat bran obtained by the wet heat treatment to obtain a finely pulverized product.
Step 5: A step of classifying the finely pulverized product into a fine powder bran fraction having a median diameter of 200 μm or less and other fractions, and collecting the fine powder bran fraction. In the wet heat treatment of the said process 3, the wheat bran obtained at the said process 2 is wet-heat-treated in the closed system container which introduce | transduces water vapor | steam with the heating temperature of 80-110 degreeC and the heating time of 1 to 60 seconds. Of fine powder bran. The method for producing fine powder bran according to claim 1 or 2 , wherein the content of the alkyl resorcinol in the fine particle fraction is 0.35 mass% or more.