JPH036779B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a fish and shellfish farming method using glutathione and a fish and shellfish feed containing glutathione. In recent years, the types and quantities of fish and shellfish targeted for aquaculture have been increasing every year. However, although the technology for improving productivity in these aquaculture operations has been established, the quality of the fish and shellfish produced remains
In particular, the body color differs from that of wild fish and shellfish, which is a cause of a significant decrease in the commercial value of farmed fish and shellfish. Regarding the body color of farmed fish and shellfish, it has been pointed out that there is a lack or weakness of red or yellow body color, and the phenomenon of blackening of the entire fish body. It has been clarified that the former is caused by a lack of carotenoid substances in the feed, and in fact, synthetic β-carotene and canthaxanthin, or krill, spirulina, chlorella, etc. that contain natural carotenoid substances are The color of the body has improved. On the other hand, the latter is said to be caused by the effects of sunlight due to feeding in shallow water and stress caused by the breeding environment such as high stocking density. ,
A certain degree of suppressive effect on body darkening has been obtained. However, the above measures are still insufficient, as even when carotenoid pigments are administered, the body turns red-black, parts of the body that are originally white turn black, and black streaks become noticeable when cooked as sashimi. do not have. Furthermore, sun cover and bottom cages require additional material costs and are fraught with problems, such as requiring complicated work in daily aquaculture management. The present inventors focused on the fact that the main causes of darkening of the body color of these farmed fish and shellfishes are the increase in melanin pigment and the diffusion of melanin pigment within melanophores, and found that As a result of investigating various breeding tests to find effective means for preventing darkening of the body color of cultured fish and shellfish using substances, it was discovered that the administration of glutathione showed a remarkable effect, and the present invention was completed. That is, the first aspect of the present invention is a method for cultivating fish and shellfish characterized by using glutathione, and the second aspect of the present invention is a fish feed containing 0.025% by weight or more of glutathione. Glutathione used in the present invention is a tripeptide represented by the following formula, and is synthesized by fermentation. In the present invention, any of crystalline glutathione, crudely purified glutathione, yeast containing glutathione, etc. can be suitably used. Crudely purified glutathione includes an aqueous extract of glutathione-containing yeast and dried products of glutathione-containing liquids at various stages before crystallization. Possible ways to use it include adding it to compound feed in advance, scattering, spreading, or adsorbing it on raw feed or compound feed during feeding, and dissolving glutathione in the water used to prepare the feed. Conveniently, it is fed as a feed containing 0.025% or more of glutathione. Furthermore, apart from feed, for example, medicated baths, injections, etc.
Similar effects can be obtained when administered in the form of tablets. Examples of target farmed seafood include fish such as yellowtail, sea bream, eel, striped horse mackerel, tiger puffer fish, flounder, sweetfish, carp, and trout; crustaceans such as sea bass and prawn; and shellfish such as abalone, scallop, and oyster. Ru. The dosage is preferably 20 mg to 1000 mg per kg of cultured fish and shellfish body weight per day, and the administration period is preferably 1 week to 6 months before shipping from both an effective and economical standpoint. If the amount is less than 20 mg, the effect of improving body color is insufficient, and on the other hand, if the amount exceeds 1000 mg, no more significant effect will be seen and the economic burden will become heavy, which is not practical. When using glutathione-containing yeast, yeast with a content of approximately 1% or more (based on dry bacterial weight) should be used, and the dosage may be determined by taking into account the glutathione content in the yeast used. Conventionally, torula yeast and brewer's yeast have been used as feeding materials, but these are used to supply trace nutrients such as protein sources, and there are no examples that suggest the effects of glutathione. There are no examples where the content was clearly specified. As far as the present inventors have measured, the glutathione content of these feed and feed yeasts was 0.1% or less. Normally, these yeasts are added at most 10% to feed, and in order to achieve the effects of the present invention, it is necessary to add 25% or more, which cannot be used as feed from the standpoint of palatability and nutritional balance. According to the present invention, not only the prevention of darkening of the body color but also the improvement effect on deterioration of cultured fish, specifically a decrease in liver function, a decrease in appetite, etc. are observed. That is, by carrying out the present invention, it is expected that at the same time as improving body color, debility caused by decreased liver function in cultured fish will be improved, and in healthy cultured fish, disease and debility will be prevented by enhancing liver function. be done. Next, the present invention will be further explained with reference to Examples.
Of course, the present invention is not limited in any way by these. Example 1 A red sea bream rearing test was conducted as follows. The feed for sea bream aquaculture having the composition shown in Table 1 was formed into pellets and used as a control feed. Krill meal was added as a carotenoid pigment source. For red sea bream, 80 1-year-old fish weighing over 200 g were used in each group.

【table】

[Table] The test feed was prepared by uniformly spraying and adsorbing 60 ml of a 10% aqueous solution of glutathione to the above control feed, and then adsorbing the same amount of glutathione per day in the control feed.
It was prepared so that 6.00g was contained in 426g. Using control feed and test feed, 2m (length) x 2m
Red sea bream were raised in a cage measuring (width) x 2 m (depth) for 30 days. Sunshades were installed in the fish preserves in all wards. The breeding results are summarized in Table 2. As a result of this test, it was confirmed that the administration of glutathione prevented blackening, brightened the body color, and produced healthy red sea bream similar to those found in nature.

【table】

[Table]
Example 2 A red sea bream rearing test was conducted as follows. Mixed feed mash for live bait exhibition was prepared according to the formulation shown in Table 3. At the time of feeding, mix the feed ingredients shown in Table 4,
It was ground into mince and fed. The size of the fish tank is 3m (length) x 3m (width) x 3.2
In each case, shade was installed at m (depth), and red sea bream were reared for 30 days. A total of 105 one-year-old red sea bream fish weighing just over 300 grams were used in each group. After the test, the fish flesh was observed, paying attention to the body color and the body color 12 hours after being killed immediately, and the fish flesh was cut into three pieces, paying attention to the black streaks seen on the cut surfaces.

[Table] The content is 4.0% by weight, and the glutathione content in brewer's yeast is less than 0.1% by weight (detection limit).

[Table] Table 5 summarizes the breeding results and test results. As a result of this study, administration of glutathione
It was confirmed that body color, post-mortem body color, and fish meat color were all improved.

【table】

[Table] *1 Calculated based on the fish weight at the start of the test.
Example 3 Using the feed shown in Tables 3 and 4 of Example 2, a red sea bream breeding test was conducted under the same conditions except that no shade was provided. The breeding results and test results are shown in Table 6. As a result of this test, it was confirmed that glutathione administration has the same effect on preventing darkening as when installing a sunshade, even without a sunshade.

【table】

[Table] *1 Calculated based on the fish weight at the start of the test.
Example 4 A breeding test using eels was conducted as follows. Prepare eel aquaculture feed with the composition shown in Table 7,
This was used as a control feed. The test feed was prepared by dissolving 3.0 g of glutathione in 1.2 g of water added at the time of formulating the feed, so that the amount of glutathione per day was determined.
It was prepared so that 3.0g was contained in 1000g. Eels weighing approximately 100 g each were used, and the number of eels (approximately 500 eels) was used so that the total fish weight in each area was 50 kg.
The results after rearing for 90 days are summarized in Table 8.

【table】

[Table] *1 Calculated based on the fish weight at the start of the test *2 Compound feed content The results of this test showed that administration of glutathione improved the overall darkened body color that is characteristic of farmed eels. was confirmed.

Claims (1)

[Claims] 1. A method for cultivating seafood, characterized by using glutathione. 2. Glutathione from 1kg of seafood per day
The method according to claim 1, wherein 20 to 1000 mg is administered. 3. The method according to claim 1 or 2, in which glutathione is mixed into a compounded feed. 4. The method according to claim 1 or 2, in which the aqueous glutathione solution is sprinkled, spread, or adsorbed on feed. 5. The method according to claim 1 or 2, wherein the glutathione aqueous solution is used as water for making a paste. 6. The method according to claim 1 or 2, wherein glutathione is administered separately from feed. 7. The method according to claim 1, wherein the glutathione is crystalline glutathione, crudely purified glutathione, or glutathione-containing yeast containing 1% or more (based on dry bacterial weight) of glutathione. 8 Seafood feed containing 0.025% by weight or more of glutathione. 9. The feed according to claim 8, wherein the glutathione is crystalline glutathione, crudely purified glutathione, or glutathione-containing yeast containing 1% or more (based on dry bacterial weight) of glutathione.