JP2005176799A - Body color improving agent for cultured fish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide body color improving properties of cultured fish excellent in solving dinginess of the body color caused by melanin production of cultured fish such as red sea bream, improving use efficiency of carotenoid such as astaxanthin to be used for coloring finish, improving body color clearing effect with carotenoid, and also living body safety. <P>SOLUTION: A body color improving agent for cultured fish to be used together with compound feed for cultured fish has as the essential components ferulic acid and γ-oryzanol. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention particularly relates to a body color improving agent for cultured fish used together with a mixed feed for cultured fish containing carotenoids or not containing carotenoids.
More specifically, the present invention relates to a cultured fish body color improving agent comprising ferulic acid and γ-oryzanol as essential components, particularly used together with a mixed feed for cultured fish containing or not containing carotenoids, or the ferulic acid described above. And γ-oryzanol for improving the body color of farmed fish prepared by defatted rice bran.

  In recent years, as fish farming has flourished, not only body weight, freshness, and meat quality, but also body color has become an important factor in evaluating the quality of farmed fish.

  The body color of red sea bream is expressed by pigments such as red carotenoid astaxanthin and yellow carotenoid tunaxanthin and black melanin. For example, the body side of natural red sea bream has a bright red color and the abdomen is white and has a beautiful contrast.

On the other hand, cultured red sea bream has a drawback that the body color is darkened as a whole compared to natural red sea bream. This is because cultivated red sea bream is bred at a shallower depth than the natural red sea bream's reproductive site, and tannin is generated and deposited on the body surface by sunburn.
For this reason, it is not sufficient to administer the carotenoid, which is a red-yellow pigment, to produce vivid red and abdominal white color found in natural red sea bream with cultured fish. The generation must be suppressed.

Conventionally, as a technique for improving the body color by administration of the carotenoid, ascorbic acid or a salt thereof is added as a stabilizer for carotenoids having low antioxidant properties (Japanese Patent Publication No. 37-8532), and in combination with “licorice” (specialty) No. 63-145367), a combination of a carotenoid pigment with a hydrolyzed product of defatted egg yolk and a water-soluble antioxidant (Japanese Patent Laid-Open No. 2000-106848), a combination of glutathione to increase the absorption efficiency of astaxanthin (specialty) Kaihei 7-231755) has been proposed, but has not been sufficiently effective.
In addition, as a method for improving meat color, that is, as a method for reducing the color of livestock meat (increasing product value by reducing the color of livestock meat), a method of adding ferulic acid to feed is known (Japanese Patent Laid-Open No. 6-133). -153814), which is not relevant to the invention described below.

Further, as a method for suppressing the production of melanin, conventionally, for example, a method of blocking sunlight with a shading net or the like has been adopted. However, simply covering the sun with a light-shielding net does not provide a satisfactory effect for preventing black body color blackening.
In addition, a method using cysteine, γ-oryzanol (Japanese Patent Laid-Open No. 63-258541), and protoanthocyanidin (Japanese Patent Laid-Open No. 10-225226, Japanese Patent Laid-Open No. 2001-299232) has also been proposed. It ’s hard to say that you ’re giving it.
Furthermore, a method of adding kojic acid (Japanese Patent Laid-Open No. 3-30637), which is a melanin production inhibitor, has also been proposed. Recently, kojic acid has been pointed out to be carcinogenic, and its addition to feed is considered from the viewpoint of safety. Its use is reconsidered.

  The object of the present invention is to provide an improved body color of cultured fish such as red sea bream, which has an excellent effect in preventing body color blackening, in particular, blackening of the body color, and is excellent in safety and economy. is there.

The inventor has studied various natural products in order to achieve the above object. As a result, a preparation comprising ferulic acid and γ-oryzanol contained in rice bran as essential ingredients, or a preparation prepared by further blending defatted rice bran with the ferulic acid and γ-oryzanol, a mixed feed for cultured fish, particularly When added to cultured feed containing carotenoids and given to cultured fish, it significantly suppresses melanin production of cultured fish compared to ferulic acid or γ-oryzanol alone, and accumulates carotenoids on the body surface I also found a remarkable knowledge that
The present invention has been completed based on the above findings.

  Briefly describing the present invention, the present invention relates to a body color improving agent for cultured fish used together with a mixed feed for cultured fish, wherein the body color improving agent for cultured fish is composed of ferulic acid and γ-oryzanol as essential components. The present invention relates to a body color improving agent for cultured fish.

  In the present invention, the body color improving agent for cultured fish containing ferulic acid and γ-oryzanol as essential components is formulated by blending a desired amount of defatted rice bran, or a mixed feed for cultured fish, particularly color. It is not added to the mixed feed for cultured fish containing carotenoids for fried food, and the form of use is not particularly restricted.

  The body color improving agent for cultured fish containing ferulic acid and γ-oryzanol as essential components of the present invention has a remarkable effect on improving the body color of cultured fish when used together with the mixed feed for cultured fish.

In particular, the body color improving agent for cultured fish comprising ferulic acid and γ-oryzanol as essential components of the present invention can significantly suppress melanin production in cultured fish, and the conventional darkness of body color based on melanin production. Difficulties can be solved effectively.
And the above-mentioned inhibitory effect of melanin production is equal to or more than that when the amount of use is 1/10 to 1/20, which is very small compared to the case of using ferulic acid or γ-oryzanol alone. Therefore, the body color improving agent of the present invention is excellent in economic efficiency.

Further, the body color improving agent for cultured fish comprising ferulic acid and γ-oryzanol as essential components of the present invention, especially when added to a mixed feed for cultured fish containing carotenoids such as astaxanthin for coloring purposes, Increases oxidative stability and promotes the accumulation of carotenoids in the body.
And, the above-described body color sharpening effect through the carotenoid has an extremely small use amount of 1/10 to 1/20 compared to the case of using ferulic acid or γ-oryzanol alone. Thus, the body color improving agent of the present invention is excellent in economic efficiency.

  The body color improving agent for cultured fish comprising ferulic acid and γ-oryzanol as essential components of the present invention, in addition to the above-mentioned melanin production inhibitory effect and body color sharpening effect, Exhibits an excellent effect on oxidative stress, and further improves carotenoid oxidative stability when producing extruder pellets (EP) from mixed feed for cultured fish with carotenoids added, thus increasing the residual rate of carotenoids, etc. It exhibits various excellent effects.

  As can be seen from the above, the body color improving agent for cultured fish containing ferulic acid and γ-oryzanol as essential components according to the present invention is synergistic in improving body color by using ferulic acid and γ-oryzanol together. Both ingredients can be expressed, and both components are extremely effective because they are contained in many foods including rice bran and are always ingested by humans and are highly safe.

  The technical configuration and embodiments of the present invention will be described in detail below.

In the body color improving agent for cultured fish of the present invention, the first essential component ferulic acid is shown in the following chemical formula 1, and the second essential component γ-oryzanol is shown in the chemical formula 2 below. It is shown.
In γ-oryzanol represented by the following chemical formula 2, R represents a residue of sterol, triterpene alcohol, or higher alcohol. More specifically, R is a residue of a sterol such as β-sitosterol (C ₂₉ H ₅₀ O), stagmasterol (C ₂₉ H ₅₂ O), campesterol (C ₂₈ H ₄₈ O), C ₃₀ H ₅₀ 3 shows residues of triterpene alcohols having the composition O or C ₃₁ H ₅₂ O.

Since the ferulic acid and γ-oryzanol are contained in many foods including rice bran and are always consumed by humans, their safety has been established.
To be precise, the ferulic acid does not exist in its natural form, but is prepared by hydrolyzing γ-oryzanol.
As the γ-oryzanol, for example, an extract obtained by extracting rice bran with an organic solvent or an extract concentrate (extract extract) may be used. Ferulic acid may be prepared by hydrolyzing the γ-oryzanol.
Rice bran is a component that is often used as a component of mixed feed for cultured fish, as will be described later.As can be seen from the above, just adding rice bran to cultured fish, ferulic acid of the present invention and It does not give a body color improver composed of γ-oryzanol. In other words, the action of rice bran administration has nothing to do with the present invention.

In the body color improving agent for cultured fish of the present invention, the blending ratio and blending amount of ferulic acid and γ-oryzanol may be appropriately set.
The blending ratio of both may generally be blended with ferulic acid in a weight ratio of 0.1 to 10 times with respect to γ-oryzanol from the viewpoints of administration effect, economy and the like. Generally speaking, the amount of ferulic acid is preferably less than that of γ-oryzanol.
In the present invention, as demonstrated in Examples described later, when the blending ratio of ferulic acid and γ-oryzanol is 1: 2, an excellent synergistic body color improving effect (melanin suppressing effect, carotenoid accumulating effect) Etc.) are expressed.
The specific blending amount of both is based on the weight of the mixed feed for cultured fish applied, for example, based on the weight of the mixed feed for cultured fish, ferulic acid 1 to 5000 ppm, γ-oryzanol 1 to 5000 ppm. Preferably, the ferulic acid may be set in the range of 10 to 100 ppm and γ-oryzanol in the range of 50 to 500 ppm.

In the present invention, the body color improving agent comprising ferulic acid and γ-oryzanol can be used by directly adding to a mixed feed for cultured fish containing or not containing carotenoids.
In addition, in order to facilitate the work of adding and blending both the components of ferulic acid and γ-oryzanol into the mixed feed for cultured fish, defatted rice bran previously mixed with ferulic acid and γ-oryzanol at a certain blending ratio is used. The product prepared by diluting 10 times to 100 times may be used directly, or the product prepared as described above may be used by adding about 1 to 5% to the mixed feed for cultured fish. It should be noted that defatted rice bran is one of the typical blended components of this kind of mixed feed for cultured fish.
Furthermore, the combination preparation consisting of the ferulic acid and γ-oryzanol, or the combination preparation consisting of the ferulic acid, γ-oryzanol and defatted rice bran, in any form such as dry pellets, moist pellets and home-made feeds. You may add and use for the mixed feed for cultured fish with or without a carotenoid.

  In the body color improving agent for cultured fish according to the present invention, in the preparation prepared from the ferulic acid, γ-oryzanol and defatted rice bran, the mixing ratio of each component is Ferra based on the weight of the mixed feed for cultured fish to be applied. What is necessary is just to set suitably in consideration of the compounding quantity of an acid and (gamma)-oryzanol. For example, ferulic acid 0.01 to 10%, γ-oryzanol 0.01 to 10%, defatted rice bran 80 to 99.8%, preferably ferulic acid 0.5% to 1.0%, γ-oryzanol 1 What is necessary is just to set in -2% and defatted rice bran 97-99%.

The body color improving agent for cultured fish according to the present invention is used together with a mixed feed for cultured fish, and effectively suppresses the production of melanin in the cultured fish and contributes to improvement in body color (particularly prevention of blackening by melanin).
Further, the body color improving agent for cultured fish of the present invention is used together with a mixed feed for cultured fish containing carotenoids, and the body color is improved (especially when carotenoids are colored by carotenoid stabilization (oxidation resistance) and accumulation in the body). Increase).
In the present invention, the administration period of the body color improving agent for cultured fish of the present invention is not particularly limited, but continuous administration for 3 months or more is preferable together with a carotenoid-containing mixed feed for cultured fish in order to develop a beautiful body color.

The body color improving agent for cultured fish according to the present invention is used together with a mixed feed for cultured fish with or without carotenoids. Examples of this mixed feed for cultured fish include known red sea bream, yellowtail, Japanese flounder, salmon and the like. Marine fish; freshwater fish such as trout, amago, yamame, and ayu; shellfish such as shrimp and crab; ornamental fish such as goldfish and nishikigoi;
In the present invention, the mixed feed for cultured fish to which the body color improving agent for cultured fish of the present invention is applied should be interpreted in a broad sense so as to include the mixed feed for crustaceans as described above. .

The above described mixed feed for cultured fish will be specifically described below.
(1). Formula feed for marine fish red sea bream and yellowtail:
The general composition is animal feed (fish meal) 50-65%, cereals (wheat flour etc.)-15%, vegetable oil cake (soybean cake) -10%, alga (rice bran, bran) -5% , Other (animal fats and oils, beer yeast, calcium carbonate, calcium phosphate, etc.) to 10%. The component composition of this is 45 to 55% crude protein, 10 to 16% or more crude fat, 15 to 20% crude sugar, and 11% crude ash.

For example, the general composition of the feed for raising red sea bream (Kaidai EP4.5) manufactured by Kirin Feed Co., Ltd. is 60% animal feed, 15% cereal, 10% vegetable oil cake, and alga (rice bran, bran) ) 5% and other (animal fats and oils, beer yeast, calcium carbonate, calcium phosphate, etc.) 10%. The composition of this product is 48% crude protein, 12% crude fat, 1.8% crude fiber, 15% crude ash, 1.8% calcium, and 1.4% phosphorus.
In addition to the above-mentioned Kirin Feed Co., Ltd., the mixed feed for marine fish such as red sea bream and yellowtail, Higashimaru Co., Ltd., Nissin Feed Co., Ltd., Oriental Yeast Co., Ltd. Manufacturers such as Marubeni Feed Co., Ltd. provide mixed feeds with almost the same composition.

(2). Formula feed for freshwater fish ayu:
Nippon Agricultural Industry Co., Ltd. has a general composition of 55% animal feed (fish meal), 21% cereal (wheat flour), 10% gypsum (rice bran, bran), and vegetable oil meal. (Soybean oil lees) 7%, others (feed yeast, alfalfa meal, wheat germ, salt) 6%. The component composition of this is 45.0% crude protein, 3.0% or more crude fat, 4.0% or less crude fiber, and 15.0% crude ash.
In addition to the Nippon Agricultural Industry Co., Ltd., manufacturers such as Oriental Yeast Co., Ltd., Nippon Formula Feed Co., Ltd., and Marubeni Feed Co., Ltd. provide blended feeds having almost the same composition as the mixed feed for raising sweetfish.

In the present invention, carotenoid mixed with the cultured fish mixed feed for the purpose of deep-fried is a yellow to red fat-soluble pigment widely distributed in the animal and plant kingdoms, and has many conjugated double bonds. Including aliphatic or cycloaliphatic polyenes.
In addition, it is said that there are about 600 kinds of compounds in nature.

A typical example of the carotenoid is astaxanthin (molecular formula C ₄₀ H ₅₂ O ₄ ).
Astaxanthin is a kind of carotenoid that exhibits red color, and is distributed in microorganisms, plants, and animals. The body color of red sea bream and goldfish, the red color of salmon muscles, the color of shrimp and crab shells, etc. are due to astaxanthin.
As a physiological action of astaxanthin, a protective color, a marriage color, a UV protection action, an egg quality improvement action and an antioxidant action are known in fish. Further, in recent years, it has been found that it has a strong active enzyme scavenging action, and has attracted attention because it has been known to have a carcinogenesis preventing effect, a cancer cell growth inhibitory effect, an immune enhancing effect, etc.

  In the present invention, astaxanthin sources to be added to the cultured fish mixed feed include extracts of yeast (Pharfia rhodozima), green algae (Haematococcus pluviaris), and crustaceans such as krill and shrimp. In addition, there is also a synthetic product (Roche's product name, Carofir Pink). The latter is limited and used as a mixed feed for red sea bream, salmon, and trout.

In the present invention, as carotenoid, in addition to the above-mentioned astaxanthin, β-carotene (C ₄₀ H ₅₆ ), lutein (C ₄₀ H ₅₆ O ₂ ), zeaxanthin (C ₄₀ H ₅₆ O ₂ ), capsanthin (C ₄₀ H) ₅₆ O ₃ ) and the like.
The amount of the carotenoid added to the mixed feed for cultured fish varies depending on the type of cultured fish, the duration of the cultured fish, the shipping time of the cultured fish, and the like. For example, 1 ppm to 100 ppm may be added.

  Hereinafter, the present invention will be described in more detail with reference to examples. Needless to say, the present invention is not limited to the examples.

(1). Test feed adjustment method:
Compound feed consisting of 60% fish meal, 15% cereals, 10% vegetable oil cake, 5% alga (rice bran, bran), and 10% other (animal fats, beer yeast, calcium carbonate, calcium phosphate) The test feed was prepared by adding 60 ppm of astaxanthin to 200 kg of “feed madai EP45” (manufactured by Kirin Feed) and adding a predetermined amount of ferulic acid or γ-oryzanol as shown in Table 1 below (control group) Is not added).

(2). Breeding conditions:
Red sea bream with an average weight of around 280 g was housed in a 2 × 2 × 2.5 m net cage of 30 fish per group, 6 test zones were provided, and a breeding test was conducted at sea level for 98 days. All test plots were covered with sunshade nets. Each test group was fed a predetermined test feed twice a day for 6 days a week.

1. About breeding results:
On the 98th day of breeding, 10 fish were taken from each test group, and immediately after anesthetizing with phenoxyethanol, the body weight was measured to determine the breeding results (growth effect, feed efficiency). The breeding results are shown in Table 2 below.

  As shown in Table 2, in the test group to which ferulic acid and γ-oryzanol were administered, an increase in body weight was observed as compared to the control group, and the feed efficiency was also increased. In particular, in the second section administered with 50 ppm ferulic acid mixed with 100 ppm γ-oryzanol, it was superior to any test section (fourth or sixth section) administered with ferulic acid and γ-oryzanol alone and in a large amount (1000 ppm). There is an increase in feed efficiency.

2. About the body color sharpening effect:
In the red sea bream used for the measurement of the breeding results, the body color of the head, sides, and abdomen was measured with a color difference meter (chromameter CR-300, manufactured by Minolta). The results are shown in Table 3 below.

As shown in Table 3, the ferritic acid and γ-oryzanol administration groups (2 to 6 groups) increased in the L value indicating brightness compared to the control group (1 group) in any part of the head, side and abdomen. ing. This indicates that melanin production was suppressed by administering ferulic acid and γ-oryzanol.
Furthermore, in the 2nd section administered with 50 ppm ferulic acid mixed with 100 ppm γ-oryzanol, the L value was higher than the 4th section administered with 1000 ppm ferulic acid alone and the 6th section administered with 1000 ppm γ-oryzanol alone. Yes. This means that when ferulic acid and γ-oryzanol are mixed and administered at a ratio of 1: 2, the dose is equivalent to 1/10 to 1/20 of the single dose of ferulic acid or γ-oryzanol, or It shows that there is a body color sharpening effect that exceeds that. That is, when ferulic acid and γ-oryzanol are used in combination, it has the effect of synergistically suppressing red sea bream melanin production.

On the other hand, as shown in Table 3, the a value indicating redness is also observed in the ferulic acid and γ-oryzanol administration groups (2 to 6 groups) higher than the control group (1 group). This indicates that ferulic acid and γ-oryzanol also worked effectively for astaxanthin accumulation.
Furthermore, also in the a value, in the 2nd group administered with 50 ppm ferulic acid mixed with 100 ppm γ-oryzanol, it was higher than the 4th group administered with 1000 ppm ferulic acid alone and the 6th group administered with 1000 ppm γ-oryzanol alone. Is shown. That is, it shows that when ferulic acid and γ-oryzanol are used in combination, there is an effect of synergistically improving the carotenoid accumulation of red sea bream.

3. About carotenoid content in epidermis:
The results of examining the carotenoid content (mg / solid) in the epidermis are shown in Table 4 below.
As shown in Table 4, it is recognized that the ferulic acid and γ-oryzanol administration groups (2 to 6 groups) are higher than the control group (1 group). In particular, a high value is shown in the second section, which is a combined section of ferulic acid and γ-oryzanol.
From these results, it is possible to cultivate vivid red sea bream with a contrast of red and white close to that of natural fish by administering ferulic acid and γ-oryzanol, and also mixed ferulic acid and γ-oryzanol in a ratio of 1: 2. When using, it turns out that the effect can be reinforce | strengthened with the usage-amount of both components by the very small usage-amount of 1/10-1/20 of each single usage-amount.

4). About inhibitory effect on lipid peroxide production:
Five fish were taken from each test section (1-6), each plasma was collected, and lipid peroxide was determined by the thiobarbituric acid method. In addition, the production of this lipid peroxide (peroxide) is related to the peroxide stress of the fish being bred, and the fact that the amount of peroxide is small means that the peroxide stress is reduced, the breeding efficiency, It can be said that good results are obtained for effective use of the body color improving agent.
The results are shown in Table 5 below. Table 5 shows the amount of peroxide contained in the plasma of the fish in each test group in terms of malondialdehyde (MDA) content.
Compared to the control group (1 group), malondialdehyde (MDA) decreased in the ferulic acid and γ-oryzanol administration groups (2-6 groups). Furthermore, the MDA content of the second section administered by mixing 50 ppm of ferulic acid and 100 ppm of γ-oryzanol is the lowest compared with the other single groups. In particular, even when compared with the 4th and 6th groups administered alone as a large amount of 1000 ppm, the MDA content is even lower.
These results indicate that administration of ferulic acid and γ-oryzanol alleviated fish peroxidative stress. Furthermore, when ferulic acid and γ-oryzanol are mixed and used at a ratio of 1: 2, the effect of both components is enhanced by using a very small amount of 1/10 to 1/20 of each individual amount used. I understand that I can do it.

Cultured fish are exposed to various stress because they are cultured overcrowded in shallower water than natural fish. In particular, peroxidative stress caused by sunlight ultraviolet rays or peroxides based on oxidation of feeds (for example, peroxides generated by oxidative degradation of carotenoids with poor oxidative stability in feeds containing carotenoids) Not only does it cause darkening of the color and accumulation of carotenoids, it also causes growth disorders, deterioration of meat quality and various diseases.
As described above, the reduction of peroxidative stress by the administration of ferulic acid and γ-oryzanol according to the present invention not only has the effect of suppressing melanin production and further improving the accumulation of astaxanthin, but also promotes growth and increases feed efficiency. These points are supported by the above-mentioned various data. In the present invention, these effects are obtained when ferulic acid and γ-oryzanol are mixed and used in a ratio of 1: 2, each of which is used in an extremely small amount compared to the case where each is used alone and in a large amount. Can be strengthened.

As described above, the body color improving agent for cultured fish containing ferulic acid and γ-oryzanol of the present invention as essential components has a ratio of ferulic acid to γ-oryzanol of about 1: 2 (50 ppm: 100 ppm). Furthermore, it has the specificity of exhibiting an excellent synergistic body color improvement effect (such as melanin production inhibition, carotenoid accumulation effect, peroxide production inhibition effect).
The present inventor infers the above-described specific remark mechanism as follows.
1). In view of both ferulic acid and γ-oryzanol from the viewpoint of hydrophilicity and fat solubility (lipophilicity), ferulic acid is relatively excellent in hydrophilicity and γ-oryzanol is excellent in fat solubility.
2). In view of the chemical formula 1 (ferulic acid) and chemical formula 2 (γ-oryzanol), the part that exhibits the effect of suppressing the generation of active oxygen and the effect of suppressing melanin is this part because both share the ferulic acid part. .
By the way, R, which is a substituent of γ-oryzanol, has a high molecular weight such as a steroid, and the molecular weight ratio between the ferulic acid moiety and the R group can be approximately 1: 2.
3). Since carotenoids such as astaxanthin are fat-soluble, fat-soluble antioxidants are effective. On the other hand, it is considered that a certain amount of water-soluble one is preferable for suppressing the formation of melanin.
In addition, water-soluble and fat-soluble antioxidants are considered effective against active oxygen species.
Four). For this reason, the body color improver containing hydrophilic ferulic acid and the fat-soluble (hydrophilic) γ-oryzanol, particularly the body color improver containing both in a mixing ratio of 1: 2 is more than in other cases. Expresses an excellent synergistic body color improvement effect.

  Next, as another effect (merit) of the present invention, the merit at the time of feed preparation will be described based on test data.

5). About the astaxanthin degradation preventing effect during the preparation of extruder pellets (EP):
In the industry, pellet-type feeds are commercially available from the viewpoint of handleability and the like as cultured fish-containing feeds. As the pellet type feed, an extruder pet (EP) manufactured by an extruder is widely used.
Table 6 below shows the residual ratio of astaxanthin at the time of EP molding of the mixed feed containing astaxanthin as a carotenoid.
As shown in Table 6, in the ferulic acid and γ-oryzanol administration groups (2 to 6 groups), the residual ratio of astaxanthin is improved as compared to the control group (1 group). Furthermore, the residual rate of the second section where 50 ppm ferulic acid and 100 ppm γ-oryzanol were mixed and administered was most improved. This is because synthesizing the degradation of astaxanthin synergistically by mixing both components in a very small amount compared to the case where ferulic acid or γ-oryzanol is administered alone and in a large amount (4 and 6). It can be prevented.

Claims (6)

  A body color improving agent for cultured fish used together with a mixed feed for cultured fish, wherein the body color improving agent for cultured fish is composed of ferulic acid and γ-oryzanol as essential components. .   The body color improving agent for cultured fish according to claim 1, wherein ferulic acid is contained at a blending ratio of 0.1 to 10 times that of γ-oryzanol.   The body color improving agent for cultured fish according to claim 2, wherein the blending ratio of ferulic acid and γ-oryzanol is 1: 2.   The body color of cultured fish according to claim 1, wherein the contents of ferulic acid and γ-oryzanol are 1 to 5000 ppm for ferulic acid and 1 to 5000 ppm for γ-oryzanol, based on the weight of the mixed feed for cultured fish. Improver.   The body color improving agent for cultured fish according to claim 4, wherein ferulic acid is contained in an amount of 50 ppm and γ-oryzanol is contained in an amount of 100 ppm. The body color-improving agent for cultured fish according to claim 1, wherein the body color-improving agent is formulated with ferulic acid and γ-oryzanol by defatted rice bran.