Defatted rice bran and method for producing defatted rice bran

Abstract

To provide defatted rice bran improved in flowability.SOLUTION: The defatted rice bran has an oil content of 6 to 19 mass% and a ratio of 5% or less of particles having a particle diameter of 50 μm or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to defatted rice bran and a method for producing defatted rice bran.

Background Art

[0002] Generally, food compositions containing defatted rice bran are known. Patent Document 1 discloses rice bran defatted until the lipid content as oil becomes 5 to 15% by mass. A beverage composition containing micronized defatted rice bran obtained by pulverizing this rice bran until the average particle size becomes 30 μm or less, soy milk, and refined rice oil is disclosed.

[0003] Patent Document 2 discloses rice bran tablets produced by pulverizing defatted rice bran to a predetermined particle size, granulating, and tableting. The fat content as oil in the defatted rice bran is 4% or less, and it is disclosed that particles having a particle size of 50 μm or more are contained in 5% or less of the whole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, defatted rice bran containing about 6 to 19% by mass of oil has low fluidity, and thus, for example, when used as a raw material for food processing, which is a raw material of a food composition, the working efficiency tends to decrease. Specifically, when charging defatted rice bran into a mixing tank such as a tank, there are cases where even if the container containing the defatted rice bran is tilted, the defatted rice bran does not easily fall from the container, and there is a problem that it takes time to charge it into the mixing tank.

[0006] Generally, among powders with relatively large particle sizes and powders with relatively small particle sizes, the powders with relatively small particle sizes tend to have greater friction between particles, resulting in a tendency for reduced fluidity. The present invention was made by discovering that, contrary to the above tendency, in defatted rice bran containing a predetermined amount of oil, powders with relatively small particle sizes and a predetermined particle size distribution have better fluidity.

Means for Solving the Problems

[0007] The gist of the defatted rice bran for solving the above problems is that it contains 6 to 19% by mass of oil and the proportion of particles with a particle size of 50 μm or more is 5% or less. Regarding the above defatted rice bran, it is preferable that the oil content is 10 to 15% by mass.

[0008] Regarding the above defatted rice bran, it is preferable that the proportion of particles with a particle size of 50 μm or more is 2% or less. The gist of the method for producing defatted rice bran for solving the above problems is that it has a pressing step of pressing rice bran so that the oil content becomes 6 to 19% by mass, and a grinding step of grinding the rice bran that has undergone the pressing step so that the proportion of particles with a particle size of 50 μm or more becomes 5% or less.

[0009] Regarding the method for producing the above defatted rice bran, in the pressing step, it is preferable to press the rice bran so that the oil content becomes 10 to 15% by mass. Regarding the method for producing the above defatted rice bran, in the grinding step, it is preferable to grind the rice bran so that the proportion of particles with a particle size of 50 μm or more becomes 2% or less.

Effects of the Invention

[0010] According to the present invention, the fluidity of defatted rice bran is improved.

Modes for Carrying Out the Invention

[0011] An embodiment embodying the defatted rice bran according to the present invention will be described. The defatted rice bran of this embodiment contains 6 to 19% by mass of oil and the proportion of particles with a particle size of 50 μm or more is 5% or less.

[0012] When the proportion of particles with a particle size of 50 μm or more in defatted rice bran is 5% or less, even if it contains 6 to 19% by mass of oil, its fluidity can be made good. Therefore, when used as a raw material for food processing, a decrease in working efficiency can be suppressed.

[0013] In addition, since defatted rice bran contains 6 to 19% by mass of oil, the oil can be suitably used as a nutritional component of a food composition. As described later, the fluidity of defatted rice bran can be evaluated by measuring the angle of repose of defatted rice bran. In the evaluation of the fluidity of defatted rice bran, the angle of repose is preferably 90° or less.

[0014] The oil content of the above defatted rice bran is preferably 10 to 15% by mass. The above defatted rice bran preferably has a proportion of particles with a particle size of 50 μm or more of 2% or less. In addition, the above defatted rice bran preferably has 99.5% of the whole within the range of a particle size of 0.01 to 100 μm. By reducing the proportion of those with a particle size exceeding 100 μm, the fluidity can be made better.

[0015] The method for measuring the proportion of particles with a particle size of 50 μm or more and the proportion of particles within the range of a particle size of 0.01 to 100 μm is not particularly limited, and it can be measured using a known particle size distribution measuring device. Examples of known particle size distribution measuring devices include a laser diffraction / scattering type particle size distribution meter (manufactured by Seishin Enterprise Co., Ltd., LMS-3000).

[0016] The rice bran used for defatted rice bran is not particularly limited, and known rice bran can be used. Examples of known rice bran include those by-produced when brown rice is polished to produce white rice, such as the pericarp, seed coat, aleurone layer, and starch layer of brown rice.

[0017] Since the rice bran used for defatted rice bran generally contains about 20% by mass of oil, there is a risk that the oxidation of oil by lipase will proceed rapidly. Therefore, it is preferable to perform a lipase inactivation treatment at the earliest possible time after polishing. The lipase inactivation treatment is not particularly limited, but for example, it is performed by heat-treating the rice bran at 70 to 130 °C. For the heat treatment, for example, a cooking device, a dry extruder, a wet extruder, a steam treatment device, etc. can be used.

[0018] Instead of performing the lipase inactivation treatment, commercially available rice bran that has been previously subjected to the lipase inactivation treatment may be used. A method for producing defatted rice bran will be described.

[0019] The method for producing defatted rice bran of the present embodiment includes a pressing step of pressing rice bran so that the oil content becomes 6 to 19% by mass, and a grinding step of grinding the rice bran that has undergone the pressing step so that the ratio of particles having a particle size of 50 μm or more is 5% or less.

[0020] The pressing step will be described. The method for pressing rice bran in the pressing step is not particularly limited, and a known pressing method can be adopted. Examples of known pressing methods include a method of mechanically pressing rice bran heated to 100 to 120 °C with a low-temperature continuous press (for example, a Miracle Chamber sold by Technosigma Co., Ltd.). By adjusting the pressure and time in the pressing step, the amount of oil in the defatted rice bran can be controlled. In other words, the defatted state of the rice bran can be controlled.

[0021] Here, as methods for defatting rice bran, in addition to the pressing method, an organic solvent extraction method, a supercritical defatting method, etc. are known. However, it is difficult to control the amount of residual oil with the organic solvent extraction method and the supercritical defatting method. In addition, there is a risk that organic solvents will remain with the organic solvent extraction method. According to the above pressing method, it is easy to control the amount of oil and there is no risk of residual organic solvents. Therefore, it is suitable for the production of defatted rice bran as a food processing raw material.

[0022] The method for measuring the amount of oil in rice bran that has undergone the pressing process is not particularly limited. For example, it can be measured by an oil content measurement method based on the standard oil and fat analysis test method established by the Japan Oil Chemists' Society.

[0023] The grinding process will be described. The method for grinding rice bran in the grinding process is not particularly limited, and a known grinding method can be adopted. As a known grinding method, for example, it can be carried out using a known grinder. Examples of known grinders include a cyclone mill, a jet mill, a hammer mill, a pin mill, a roller mill, a stone mill, a disk mill, etc.

[0024] After grinding using the above grinder, classification may be carried out using a known classifier. Further, after classification, the particles may be blended so that the defatted rice bran has a predetermined particle size distribution. That is, the grinding process may include a classification process and a blending process.

[0025] Examples of known classifiers include a dry classifier. Further, examples of dry classifiers include a gravity classifier, an inertial classifier, a centrifugal classifier, etc. By going through the above respective steps, the defatted rice bran of the present embodiment can be produced.

[0026] The defatted rice bran of the present embodiment is in the form of particles having a plurality of corner portions. Specifically, the shape of the defatted rice bran is not spherical, but is formed into small flakes having a plurality of irregularities on the surface. The use of the defatted rice bran of the present embodiment is not particularly limited, and it is preferably used as a raw material for food processing, which is a raw material of a food composition. The classification of the food composition is not particularly limited, and it can be used in general foods, health functional foods, special purpose foods, etc. Further, as a health functional food, it can be used in foods for specified health use, nutritional functional foods, foods with functional claims, etc.

[0027] The form of the food composition is not particularly limited, and examples include liquid, powder, flake, granule, paste, tablet, etc. Examples of the above liquid include beverages, soups, curries, etc. Examples of the above powder include powdered beverages, powdered soups, etc.

[0028] More specifically, as the form of the food composition, there are seasonings (sweeteners, salt substitute compositions, soy sauce, vinegar, miso, sauce, ketchup, dressing, spices, herbs, etc., flakes (furikake, rice cooker additives, etc.), barbecue sauce, roux paste (curry roux paste, etc.)), food ingredient premixes, etc.

[0029] Furthermore, as the form of the food composition, there are also confectioneries such as tablet confectioneries, jellies, snacks, baked confectioneries, fried confectioneries, cakes, chocolates, gums, candies, gummies, etc., noodles, ham and sausage, ice cream, tofu, cheese, yogurt, etc.

[0030] Note that the above tablet form is generally manufactured using defatted rice bran with a low oil content, for example, about 4% by mass or less of oil. Therefore, as the form of the food composition using the defatted rice bran of the present embodiment, it is preferably not included in the tablet form.

[0031] In addition to the defatted rice bran of the present embodiment, the food composition may contain additives acceptable for foods. There is no particular limitation on the additives acceptable for foods, but examples include solvents, softeners, oils, emulsifiers, preservatives, acidulants, sweeteners, bitter agents, pH adjusters, stabilizers, colorants, ultraviolet absorbers, antioxidants, humectants, thickeners, fixing agents, dispersants, fluidity improvers, wetting agents, fragrances, seasonings, flavor modifiers, etc. The content of these additives is not particularly limited, and they can be contained within a range acceptable as an influence on the present embodiment.

[0032] The effects of the defatted rice bran of the present embodiment will be described. (1) It contains 6 to 19% by mass of oil, and the proportion of particles with a particle size of 50 μm or more is 5% or less. Even if it contains 6 to 19% by mass of oil, the fluidity of defatted rice bran can be improved. Therefore, when used as a raw material for food processing, a decrease in work efficiency can be suppressed.

[0033] (2) The oil content is 10 to 15% by mass. In using defatted rice bran as a raw material for food processing, the oil content is suitable. Therefore, in defatted rice bran suitable as a raw material for food processing, the fluidity can be improved.

[0034] (3) The proportion of particles with a particle size of 50 μm or more is 2% or less. Therefore, the fluidity of defatted rice bran can be made better. This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0035] · The use of the defatted rice bran in this embodiment is not limited to being a raw material for food processing. For example, it can also be used as pharmaceuticals, quasi - drugs, and cosmetics.

Examples

[0036] Hereinafter, in order to make the configuration and effects of the present invention more specific, examples and the like are given, but the present invention is not limited to these examples. The rice bran immediately after polishing was heated to 95°C for lipase deactivation treatment. Further, it was heated to 108°C and pressed using a low - temperature continuous press (Miracle Chamber sold by Technosigma Co., Ltd.). The oil content of the pressed rice bran was 13.1% by mass. Next, the rice bran was ground using a grinder (Cyclone Mill 400S) manufactured by Shizuoka Plant Co., Ltd.

[0037] By the above procedure, the defatted rice bran of Example 1 shown in Table 1 was produced. The defatted rice bran of Example 2 and Comparative Examples 1 - 3 was produced in the same manner as Example 1, except that the grinding conditions were changed, and appropriate classification treatment and blending treatment were carried out as appropriate.

[0038] [Table 1] (Evaluation Test) For the defatted rice bran of Examples 1 and 2 and Comparative Examples 1 to 3, the particle size distribution and fluidity were evaluated. The measurement method of the particle size distribution and the evaluation criteria of the fluidity are shown below.

[0039] (Particle Size Distribution) The particle size distribution of the defatted rice bran was measured by the laser diffraction / scattering method using a laser diffraction / scattering type particle size distribution analyzer (manufactured by Seishin Enterprise Co., Ltd., LMS-3000) with isopropyl alcohol as the dispersion medium. The measurement results are shown in Table 1. In Table 1, the average particle diameter is the median diameter. Also, for the defatted rice bran of Examples 1 and 2, 99.5% of the whole was in the range of particle diameters of 0.01 to 100 μm. In Comparative Examples 1 to 3, they were 100%, 91.9%, and 100% respectively.

[0040] (Fluidity) The fluidity was evaluated by the tilt method using a "bulk density and angle of repose meter" manufactured by Fluid Industry Co., Ltd. The defatted rice bran of each example was put into the main body of the bulk density and angle of repose meter up to about half and the lid was closed. At the position where the needle of the angle meter pointed to 0°, it was gently tapped or shaken to make the surface layer located at the upper end of the defatted rice bran as horizontal as possible.

[0041] The bulk density and angle of repose meter was slowly rolled by hand, and the angle (angle of repose) indicated by the angle meter was visually read when the particles on the surface layer of the defatted rice bran began to slide. The fluidity was evaluated according to the following criteria.

[0042] ·Evaluation Criteria for Fluidity ○: When the angle of repose is 90° or less ×: When the angle of repose exceeds 90° From the results in Table 1, according to the present invention, the fluidity of the defatted rice bran was good. Therefore, when used as a raw material for food processing, a decrease in work efficiency can be suppressed.

Claims

**Claim 1** Defatted rice bran containing 6 to 19% by mass of oil, with the proportion of particles having a particle size of 50 μm or more being 0.72% or less, and being in the form of small flakes that are not spherical and have a plurality of irregularities on the surface. **Claim 2** The defatted rice bran according to claim 1, wherein the oil content is 10 to 15% by mass. **Claim 3** A pressing step of pressing rice bran so that the oil content becomes 6 to 19% by mass, and a pulverizing step of pulverizing the rice bran that has undergone the pressing step so that the proportion of particles having a particle size of 50 μm or more is 0.72% or less and making it into small flakes that are not spherical and have a plurality of irregularities on the surface, characterized in that the method for producing defatted rice bran has these steps. **Claim 4** The method for producing defatted rice bran according to claim 3, wherein in the pressing step, the rice bran is pressed so that the oil content becomes 10 to 15% by mass.

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