JPH09248135A - Vitamin c metabolism-improving agent for cultured fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject improving agent, composed of a tea (Camellia sinensis L.) component, free from giving ill effects on the growth of culturing fish and on feed efficiency, and capable of improving vitamin C metabolism, increasing collagen content in muscles, enhancing fat mobilization efficiency and contributing the improvement of meat quality. SOLUTION: This improving agent is composed of a tea component. As the tea component, commonly tea leaves, crushed bodies of tea leaves, an extract of tea leaves or a refined substance obtained from the extract can be used. Among the tea components, (-)epigallocatechin gallate is preferable. The compound is obtained e.g. by passing a tea-leaf extract, obtained with warm water or hot water, through a column filled with hydroxypropyl-modified dextran gel followed by eluting with a 40-85% methanol aqueous solution. Further, the objective improving agent is preferably used by adding to an existing feed for cultured fish in such a manner that the content of tea polyphenol in the feed becomes 0.2-1wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vitamin C metabolism-improving agent for cultured fish and a fish feed containing the same.
More specifically, the vitamins of cultured fish that improve vitamin C metabolism of the cultured fish and consequently increase collagen content in muscle and carnitine content in the body to improve fat mobilization ability and contribute to improvement of meat quality. The present invention relates to a C improver and a fish feed containing the same.

[0002]

2. Description of the Related Art In the production of farmed fish, there is a tendency for overfeeding, the accumulation of a large amount of lipids in the body, and the deterioration of taste in order to grow efficiently in a short period of time. Therefore, as an effective method for preventing excessive accumulation of lipids, there is known a method of feeding an oil and fat composition for fish feed comprising medium-chain fatty acid triglyceride and soybean lecithin (JP-A-4-2).
No. 52145). On the other hand, factors affecting the meat quality include muscle collagen content in addition to the existing form of lipids. Muscle collagen content contributes to meat texture. Natural red sea bream has more muscle collagen than cultured red sea bream. As a method of increasing the muscle collagen content of cultured fish, a method of adding Du Fuchu leaf powder to the feed has been reported (Biosci. Biotech. Biochem., 57, 205 (1993)). By the way, it is known that vitamin C is required for collagen synthesis. Vitamin C is also involved in lipid metabolism in fish, and vitamin C is required for carnitine biosynthesis involved in β-oxidation of fatty acids (Fisheries Sc
i., 61, 501 (1995)). Therefore, by improving the vitamin C metabolism of cultured fish, it is expected that excessive fat accumulation is prevented, the collagen content of muscle is increased, and the meat quality is improved. However, until now, feed additives that are expected to have such effects have not been provided.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to
It is intended to provide a vitamin C metabolism improving agent for cultured fish.
Another object of the present invention is to improve a vitamin C metabolism-improving agent for farmed fish, which enhances collagen content in muscle of fish and enhances mobilization capacity of fat by increasing carnitine content in the body, which contributes to improvement of meat quality. To provide. Still another object of the present invention is to provide a fish feed containing the above vitamin C metabolism improver of the present invention. Still other objects and advantages of the present invention will become apparent from the following description.

[0004]

The above objects and advantages of the present invention are first achieved by a vitamin C metabolism-improving agent for cultured fish comprising a tea component. The inventors have sought a vitamin C metabolism-improving agent for fish satisfying the above-mentioned object as a natural product, and as a result, found that leaf components of tea ( Camellia sinensis L.) have an action of improving vitamin C metabolism of cultured fish. They have found and completed the present invention. Examples of the tea component in the present invention include (+)-catechin, (+)-gallocatechin, (-)-gallocatechin gallate, (-)-epicatechin, (-)-epicatechin gallate, (-)- Epigallocatechin and (−)-epigallocatechin gallate are preferred targets. Of these, (-)-
Most preferred is epigallocatechin gallate.

The tea component can be used as it is or in the form of crushed tea leaves, or as an extract obtained by extracting components from tea leaves, or as a purified product thereof. As the extraction solvent, water, warm water, hot water, or an organic solvent such as methanol, ethanol, acetone, ethyl acetate or ether can be used. In particular, epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate can be prepared by the methods described in JP-A-1-175978 and JP-A-4-182479.

For example, tea leaves are extracted with warm or hot water, the extract containing the water-soluble compound is injected into a column packed with hydroxypropylated dextran gel or hydrophilic vinyl polymer gel, then with distilled water, then with methanol, The column was washed with an aqueous solution of ethanol or acetone, and then a fraction containing (−)-epicatechin, (−)-epigallocatechin was eluted through a 20% to 30% aqueous solution of methanol, ethanol or acetone to further elute 40 to 85%. %
These tea components can be prepared by eluting the fraction containing (−)-epicatechin gallate and (−)-epigallocatechin gallate through an aqueous solution of methanol, ethanol, or acetone in (1).
(See Japanese Patent No. 5978).

Alternatively, a water-soluble component is extracted from tea leaves in the same manner, and the extract containing the same is used as a synthetic adsorbent such as methacrylic acid ester-based or styrenedivinylbenzene-based or textran derivative or hydrophilic. It is passed through a chromatographic column packed with a gel filtration agent having a vinyl polymer as a matrix, and then the adsorbed component is eluted through an aqueous solution containing at least one selected from the group consisting of methanol, ethanol and acetone or an aqueous solution containing 40% or more thereof.
The eluate thus obtained is subjected to an extraction treatment with at least one solvent selected from the group consisting of ethyl acetate, methyl isobutyl ketone and diethyl ether, and the components transferred to the solvent are distilled off to recover the solvent. The same tea component can be prepared (Japanese Patent Laid-Open No. 4-182479).
Reference).

The vitamin C metabolism-improving agent for cultured fish of the present invention comprises a tea component alone or, for example, one of feed components for cultured fish.
It can be provided together with the department. The vitamin C metabolism-improving agent of the present invention is used by adding tea polyphenols to an existing fish feed such that the tea polyphenols are contained in an amount of 0.2 to 1% by weight, and a desired effect is produced. Next, examples of the present invention will be described.

[0009]

[Example] Red sea bream 0-year-old fish (body weight: about 18 g) 150 3
It was cultivated in a 0.5 ton indoor water tank made of FRP in 6 groups, and after 1 week of preliminary breeding, test breeding was carried out for 40 days. The feeding was twice a day, and about 2% of the body weight was administered. In the control, 63% brown meal, 10% wheat gluten, 10% alpha starch, 5% vitamin mixture, 4 mineral mixture.
%, Sardine oil 5%, and cellulose 3%, and the feed was prepared by molding. In the test section, 1% of 3% of the cellulose in the control group feed was used as a green tea extract and refined product (purified and dried product of hot water extract of green tea containing 60 to 70% of tea catechins, manufactured by ITO EN Co., Ltd .: The feed was replaced with the trade name Theafran 60). After the test was completed, blood was collected from the tail stalk, and the obtained serum was refrigerated for analysis.
Immediately after immediate killing, the back muscles and liver were removed, frozen in liquid nitrogen, and stored at -80 ° C until analysis.

Ascorbic acid in serum is 9% of 5%.
Extracted with metaphosphoric acid, Roseand Nahwol
Quantitation was performed by high performance liquid chromatography (HPLC) according to the method (d) (Anal. Biochem., 114, 140-145 (1981)). Ascorbic acid was detected at 254 nm and dehydroascorbic acid was detected at 210 nm. Ascorbic acid in the liver was extracted with 9 times the amount of 2% metaphosphoric acid and quantified in the same manner as above.

Free carnitine and acid-soluble carnitine in the liver were extracted by homogenizing the liver with 8 volumes of 6% perchloric acid and centrifuging at 500 G to obtain a supernatant. The amount of free carnitine was determined by adding 0.5M to the supernatant.
The mixture was neutralized by adding 3M potassium carbonate containing triethanolamine, ice-cooled for 30 minutes, treated with an enzyme, and subjected to HPLC analysis according to the method of Miyazaki et al. (Fisheries Sci., 62,225-227 (1994)). Acid-soluble carnitine
To the above supernatant, 1N-KOH was added to adjust the pH to 13, and the temperature was 25 ° C.
Incubate for 30 minutes at 4N-pH
Neutralize to 7.5 and treat with enzyme to produce H as described above.
It was quantified by PLC analysis. The long-chain acylcarnitine in the liver was obtained by adding 1N-KOH to the residue obtained by extracting free and acid-soluble carnitine, incubating at 55 ° C. for 2 hours, centrifuging to obtain a supernatant, and adding 0.5M triethanolamine-containing 3M carbonic acid. It was neutralized by adding potassium, treated with an enzyme, and quantified by HPLC analysis in the same manner as above.

The water content and ash content in the muscle were measured by a conventional method, the crude fat was measured by the Soxhlet method, and the crude protein was measured by the Kjeldahl method. The amount of collagen in the muscle was determined by degrading the muscle with 6N-hydrochloric acid at 116 ° C. for 16 hours, and measuring
First, hydroxyproline was quantified by the method of Y. (Anal. Chem., 38, 1961-1965 (1963)), and then calculated according to the method of Sato et al. (Nippon Suisan Gakkaishi, 55, 1467 (1989)). The results are shown in Table 1.

Growth and feed efficiency were not negatively affected by the addition of the green tea extract, and the accumulated fat in the abdominal cavity tended to decrease. The content of ascorbic acid in serum and liver increased to about twice as much as that in the control group by adding the green tea extract. The content of carnitine synthesized by ascorbic acid was significantly increased in the liver with a significant difference, suggesting that β-oxidation of fatty acids is promoted. Crude protein in the muscles of the back was higher with the addition of green tea extract, while crude fat tended to be lower. Furthermore, the amount of collagen synthesized by ascorbic acid tended to increase with the addition of green tea extract.

[0014]

[Table 1]

[0015]

By adding the fish feed additive of the present invention to feed, vitamin C metabolism can be improved without negatively affecting the growth and feed efficiency of cultured fish.
It can be expected to improve flesh quality by enhancing the ability to mobilize fat, preventing excessive accumulation, and increasing the amount of collagen in muscle to improve texture.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Heisuke Nakagawa 1-4-4 Higashihiroshima City, Hiroshima Prefecture Faculty of Bioproduction, Hiroshima University (72) Inventor Tetsuya Unno 1-4-4 Higashihiroshima City, Hiroshima Prefecture Hiroshima Prefecture University Faculty of Biological Production (72) Inventor Kenji Takii Wakayama Prefecture Higashimuro-gun Nachikatsuura-cho Urajin Kinki University Faculty of Fisheries Research (72) Inventor Ei Kumagai Wakayama Prefecture Higashimuro-gun Nachikatsuura-cho Urakami Kinki University Faculty of Fisheries Research (72) ) Inventor Yuko Hazaka 21 Goddess, Sagara-cho, Hara-gun, Shizuoka

Claims (4)

[Claims] 1. A vitamin C metabolism-improving agent for cultured fish comprising a tea component. 2. The main component of the tea component is (+)-catechin,
Selected from the group consisting of (+)-gallocatechin, (-)-gallocatechin gallate, (-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin and (-)-epigallocatechin gallate The vitamin C metabolism-improving agent according to claim 1, which is at least one polyphenol compound. 3. Use of a tea component as a vitamin C metabolism improving agent for cultured fish. 4. A fish feed containing the vitamin C metabolism improver according to claim 1 or 2.