JP2005278593A - Feed for yellowtail and method for improving meat color of yellowtail - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inexpensive feed for yellowtail increased in effect of preventing discoloration with time of red muscle after fillet processing cooking, for yellowtail which causes remarkable discoloration of red muscle among cultured fish, and to provide a method for improving meat color of yellowtail using the feed. <P>SOLUTION: The feed for yellowtail contains ≥20 wt.% of oil and fat. The ratio of n-3 high unsaturated fatty acids occupying a fatty acid composition of oil and fat in the feed is <15% and ≥8%. The feed as a substance with antioxidative activity contains at least ≥300 ppm and <1,000 ppm of vitamin C and ≥300 ppm and <700 ppm of vitamin E. The method for improving meat color of yellowtail comprises feeding the feed for yellowtail for a period of ≥1 month and ≤3 months. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a yellowtail feed and a method for improving the meat color of yellowtail using the same.

  Among the marine fish, yellowtail and the like that are often eaten raw as sashimi are strongly demanded for their improvement because of their relatively fast flesh color reduction rate in the blood-skinned muscles after cooking.

For this reason, it has been proposed to suppress discoloration by adding vitamin C or vitamin E to the feed as an effect of improving meat color reduction in bloody muscles and the like.
For example, Patent Document 1 describes that discoloration of blood muscles in yellowtail and red sea bream can be prevented by setting the vitamin C content in the feed to 1,000 to 2,000 ppm and the vitamin E content to 600 to 1,200 ppm in the feed. Has been.
In addition, the basic mechanism of discoloration of blood muscles is caused by the irreversible formation of meteoglobin (Mb) in the blood muscles by oxidation (metmyoglobin: MMb), thus preventing the discoloration of blood muscles. The addition of antioxidants, for example polyphenols such as catechins, to the feed as an objective is sometimes done at the field level.

However, in the case of Patent Document 1, it is necessary to add vitamin C and vitamin E that are significantly larger than the amount normally added to the feed, which raises the feed cost and significantly reduces the economic efficiency.
In addition, when polyphenols are used, there is a problem that the weight gain rate and the increase in the coefficient of weight increase are also caused.

JP 2002-233316 A

  The present invention eliminates the disadvantages of the prior art, and discoloration of the blood muscles after fillet processing cooking over time in cultured fish, particularly in yellowtails that are markedly discolored after cooking. An object of the present invention is to provide an inexpensive feed having an enhanced effect of preventing the occurrence of meat and a meat color improvement method using the feed.

The inventors focused on n-3 highly unsaturated fatty acids (hereinafter abbreviated as n-3HUFA) as essential fatty acids in the course of intensive studies to solve the above problems.
Many marine fish, including yellowtail, are widely known to require n-3HUFA as an essential fatty acid, and the required amount is 15-25% of feed fats and oils in yellowtail. n-3HUFA is a generic term for fatty acids having a carbon number (C) of 20 or more and a double bond starting from the third C position counting from the carboxyl group terminal (COOH). This includes EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are widely known as human health foods. However, this is not an exception in the case of farmed fish feed. In general, n-3HUFA is an EPA and DHA The content accounts for 90% or more of the whole.
However, EPA and DHA are easily oxidized because they have double bonds.
Therefore, we considered reducing the n-3HUFA content in the feed to suppress oxidation.

  However, when the n-3HUFA content in the feed is reduced to the extent that the lipid composition in the feed shows the anti-discoloration effect of blood clots, the weight gain rate and the meat growth coefficient of yellowtail tend to decrease slightly in previous studies. It is considered that there is a little difficulty in terms of productivity because it is recognized, and above all, the effect is not seen unless it is dropped to a level that is significantly lower than the required amount of essential fatty acids required by yellowtails, In some cases, the risk of essential fatty acid deficiency was considered.

However, the essential fatty acid requirement that has been clarified so far has only been tested using 1 kg or less yellowtail fish, and the amount of essential fatty acids in 2 kg or 2 year old fish that are widely distributed in the market. It turned out that the required amount is not always clear.
Therefore, the present inventors have questioned common sense so far, and examined physiological effects on yellowtail using a feed whose essential fatty acid content in feed oil and fat is less than 15% for 2-year-old yellowtail. However, if the n-3HUFA content is above a certain level, the coefficient of increase in wall thickness will increase slightly, and although there will be a slight effect on the blood properties due to the increase in vegetable oils and fats, There was no influence at all, and it was found that all three breeding tests grew smoothly. In particular, for yellowtail 2-year-old fish, even if the n-3HUFA content in feed oils and fats is less than 15%, which has been known as a requirement so far, it should be a relatively short breeding period (1 to 3 months). It became clear that there was almost no physiological influence.

However, if the n-3HUFA content alone is used to prevent discoloration of the blood muscles after fillet cooking, the n-3HUFA content must be significantly reduced.
Therefore, it was found that when the n-3HUFA content in the feed was reduced and a substance having an antioxidant activity was contained in the feed, the meat color change over time in the red blood muscles was significantly suppressed. Moreover, unexpectedly, due to the reduction in the n-3HUFA content in the feed, it is possible to suppress the flesh color change sufficiently by adding a little more than the general requirement amount of these substances having antioxidant activity. It turns out that it is obtained.

  That is, the present inventors set the n-3HUFA content in the fats and oils contained in the feed to less than 15% and 8% or more, and substances having antioxidant activity such as polyphenol, ferulic acid, vitamin C and vitamin E By including at least vitamin C in the range of 300 ppm to less than 1000 ppm and vitamin E in the range of 300 ppm to less than 700 ppm, due to their synergistic effect, it is possible to remarkably suppress the meat color change over time of the blood clot muscles and solve the above problems. The present invention has been completed based on this finding.

The present invention according to claim 1 is a feed for yellowtail containing 20% or more of fats and oils, wherein the proportion of n-3 highly unsaturated fatty acids in the fatty acid composition of the fats and oils in the feed is less than 15%, 8 The feed for yellowtail containing at least 300 ppm and less than 1000 ppm and vitamin E from 300 ppm to less than 700 ppm as substances having an antioxidant activity of at least%.
The present invention according to claim 2 is a feed for yellowtail containing 20% or more of fats and oils, wherein the proportion of n-3 highly unsaturated fatty acids in the fatty acid composition of the fats and oils in the feed is less than 15%, 8 % Or more, and as a substance having antioxidant activity, feed for yellowtail containing at least 300 ppm to less than 1000 ppm and vitamin E from 300 ppm to less than 700 ppm for 1 month to 3 months A method for improving the meat color of yellowtails characterized by the above.

According to the first aspect of the present invention, in aquaculture fish, in particular, aquaculture fish, particularly bloody muscles that are particularly discolored, the cost-effectiveness of improving the effect of preventing the discoloration of the blood muscles after the fillet cooking is improved. Feed is provided. Therefore, it is useful as a meat quality improving feed.
According to the meat color improving method of the present invention according to claim 3 using the feed for cultured fish of the present invention according to claim 1 as described above, the discoloration over time of the blood clot muscles after the fillet processing cooking is effectively performed. Can be prevented.
Furthermore, according to the present invention, by supplying this for a relatively short period of 1 month or more and 3 months or less, there is no risk of damaging growth, etc. , Discoloration over time of the blood muscle after the fillet processing cooking can be prevented.

Hereinafter, the present invention will be described in detail.
The present invention according to claim 1 is a feed for yellowtail containing 20% or more of fats and oils, and the proportion of n-3 highly unsaturated fatty acids (n-3HUFA) in the fatty acid composition of the fats and oils in the feeds It is a feed for yellowtail that contains at least 300 ppm and less than 1000 ppm vitamin C and 300 ppm and less than 700 ppm vitamin E as substances having an antioxidant activity of less than 15% and 8% or more.

  The present invention according to claim 1 relates to a feed for yellowtails, and is particularly effectively applied to yellowtails (such as yellowtails and yellowtails) whose discolored muscles are particularly discolored among cultured fishes. It is possible to effectively prevent discoloration of the blood muscles over time.

The present invention according to claim 1 is a yellowtail feed containing 20% or more of fats and oils. Here, if it does not contain 20% or more of fats and oils, the total amount of energy required for yellow 2-year-old fish cannot be satisfied.
The present invention according to claim 1 is a feed for yellowtail containing 20% or more of such fats and oils, and the proportion of n-3HUFA in the fatty acid composition of the fats and oils in the feed is less than 15%, 8% It is necessary to be above, preferably 13.7% or less, 8.3 or more.

In addition, the essential fatty acid requirement amount of yellowtail is generally 15% to 25% in the feed fat and oil, and in the present invention, it will be lower than the requirement amount. Even if the n-3HUFA content in feed fats and oils is less than 15%, which has been known as a required amount so far, there is almost no physiological effect if it is a relatively short breeding period (about 1 to 3 months) I knew I would n’t.
Therefore, the present invention can be suitably applied to a yellow 2-year-old fish that is widely distributed in the market, preferably 3 kg or more.
The yellowtail feed of the present invention according to claim 1 can be fed throughout the breeding period of the yellowtail, but if possible, immediately before shipping to the market, for example, 1 month to 3 months immediately before shipping, In particular, it is desirable to pay within 2 to 3 months immediately before shipping. Therefore, the feed start date of feed should be determined by calculating backward from the shipment date of yellowtail.

  As a means for reducing the n-3HUFA content in the feed, vegetable oil or tallow can be used in place of the fish oil added to the feed. In all the examples of the present application, palm palm oil is used, but of course, the present invention is not limited to this, and any material can be used as long as the content of n-3HUFA in the feed can be adjusted as a result. That is, soybean oil, rapeseed oil, corn oil and the like can be used in addition to palm oil used in the present embodiment in the case of vegetable oil, and beef tallow, pork fat, chicken oil and the like can be used in the case of tallow.

Next, as substances having antioxidant activity, various polyphenols, organic acids (ferulic acid, etc.), carotenoids (β-carotene, astaxanthin, zeaxanthin, capsaicin, etc.), amino acids, peptides in addition to vitamin C and vitamin E , Nucleobases, sulfur-containing compounds (such as glutathione), citric acid, phospholipids, sugar alcohols, organic metals (such as selenium) can be used, but at least vitamin C and vitamin E are used in combination. It is desirable.
In the present invention, these necessary addition amounts can be significantly reduced as compared with the case where only a substance having antioxidant activity is used. For example, Patent Document 1 requires that the vitamin C content in the feed be 1,000 to 2,000 ppm and that the vitamin E content be 600 to 1,200 ppm in the feed. In the present invention, the vitamin C content is 300 ppm or more and 1000 ppm. The vitamin E content is 300 ppm or more and less than 700 ppm, more preferably the vitamin C content is 300 ppm or more and 500 ppm or less, and the vitamin E content is 500 ppm or more and less than 700 ppm.

  The present invention according to claim 1 is a yellowtail feed containing 20% or more of fats and oils as described above, wherein the proportion of n-3HUFA in the fatty acid composition of the fats and oils in the feed is less than 15%, 8 As long as it contains at least 300 ppm to less than 1000 ppm and vitamin E from 300 ppm to less than 700 ppm as a substance having an antioxidant activity of at least%, other than that, it is a normal aquaculture fish feed May be the same as, for example, EP feed.

  Next, the present invention according to claim 2 relates to a method for improving the meat color of yellowtails, which is a feed for yellowtails containing 20% or more of fats and oils, wherein n-3 is not high in the fatty acid composition of the fats and oils in the feeds. As a substance having a saturated fatty acid (n-3HUFA) content of less than 15%, 8% or more, and having an antioxidant activity, it contains at least vitamin C in a range of 300 ppm to less than 1000 ppm and vitamin E in a range of 300 ppm to less than 700 ppm. It is characterized by feeding the feed for foods for a period of not less than 1 month and not more than 3 months.

Here, the ratio of n-3HUFA in the fatty acid composition of the oil and fat in the feed for yellowtail and the substances having antioxidant activity are as described in the present invention according to claim 1.
In the present invention according to claim 2, the feed for yellowtail as described in claim 1 is fed for a period of 1 month to 3 months, preferably 2 months to 3 months. It is a feature. Since it is desirable that the feed of the feed is immediately before the shipment of the yellowtail, the feed start date of the feed may be determined by calculating backward from the shipment date of the yellowtail.
Here, when the salary is less than one month, it is impossible to effectively prevent discoloration over time of the blood-skinned muscles after the fillet processing cooking. On the other hand, when it is fed for more than 3 months, there is a risk that the weight gain rate, the wall thickness increase coefficient, etc. of the yellowtails may be lowered, which is not preferable.
As described above, as aquaculture fish, as described above, it is effectively applied to yellowtails (such as yellowtails and yellowtails) that are particularly noticeably discolored in the blood muscles. It can be effectively prevented. In particular, it can be suitably applied to 2 year old yellowtail fish that are widely distributed in the market, preferably 3 kg or more.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(1) Breeding test 1 of yellowtail using fish feed
An EP feed having a diameter of 12 mm was prepared at the mixing ratio shown in Table 1 and subjected to a breeding test. In the control group 1, only fish oil (Nice Feed Oil manufactured by Ueda Oil Co., Ltd.) was used as the fat to be added. The control group 2 is a group in which 70% of the fish oil was replaced with palm oil (palm olein, manufactured by Ueda Oil Co., Ltd.) in the control group 1, and the test group 1 is ferulic acid as an antioxidant against the control group 2. In addition, the amount of vitamin C (Hospitan C, Showa Denko Co., Ltd.) and vitamin E (Rovimix E-50, Roche Vitamin Japan Co., Ltd.) was increased from the usual addition amount. . Table 1 shows the contents of vitamin C and vitamin E in the test feed of each section. Table 1 also shows the n-3HUFA content in the feed fats and oils in each section. Breeding was carried out for 63 days by housing 50 yellowtails (2-year-old fish) each with an average fish weight of about 2,000 g in a 4 x 4 x 4 m synthetic fiber ginger (sea surface ginger). The water temperature during the breeding period was 20.4-25.0 ° C.

(2) Results of breeding tests (bred results)
The breeding results are shown in Table 2. All the wards grew steadily without any drowning during the breeding period.
That is, the average fish weight at the end was about 3000 g in all the sections, and the growth rate was almost equivalent to 140 to 144%.
On the other hand, the wall thickness coefficient of the test group 1 was 2.71, while the control group 1 was 2.33, which was slightly superior. This is because the daily feeding rate was 1.32% bw / day in the control group 1, but the test group 1 was slightly higher at 1.4% bw / day, while the growth rate was not different. I think that the. The reason why the daily feeding rate was high is presumably that the test group 1 was slightly inferior to the digestion and absorption rate compared with the fish oil because the mixing ratio of palm oil as an added fat was increased.
However, the difference in results was negligible, and there was no difference in obesity at the end of the breeding test depending on the interval.
Therefore, it can be judged that there is no problem with the feed used in Example 1 in the breeding period of 63 days.

(3) Evaluation of degree of discoloration Next, among these test fish, three fish of relatively uniform size from each ward were squeezed on the sea after the breeding test was completed, and the fish meat was made into a block shape by quickly reducing it to three. The sample was cut out, stored in a sealed container and stored in a dark place at 4.5 ° C., and the red color (a value) of the blood muscles was measured over time with a color difference meter (CR-200 manufactured by Minolta). The results are shown in FIG.
Further, using the same sample, the blood clot muscle surface was captured by a scanner, and the ratio of the discolored portion to the blood clot muscle surface area by image processing was calculated. The results are shown in FIG.
Furthermore, in accordance with the actual distribution conditions, three of these test fish, which are relatively uniform in size from each section, are squeezed on the sea after the breeding test is completed, and the fish are put into three blocks quickly and put into blocks. The sample was cut out, stored in a sealed container and stored at 10 ° C. under irradiation with a fluorescent lamp, and the red color (a value) of the blood muscle was measured with a color difference meter (CR-200 manufactured by Minolta Co., Ltd.) over time. The results are shown in FIG.

As shown in FIG. 1, in the measured value of the a value in the dark using a color difference meter, the value of the control group 1 gradually began to decrease after 72 hours, and then decreased significantly. On the other hand, in the control group 2 in which fish oil was replaced with palm oil, the a value was maintained until 96 hours, but thereafter gradually decreased. In test group 1 in which vitamin C and vitamin E were strengthened and ferulic acid was further added, the retention of a value clearly showed a higher tendency than in control groups 1 and 2. From these results, the replacement of part of the fish oil in the feed with palm oil can suppress a decrease in the a value of the blood muscle, but it also has antioxidant ability such as vitamin C, vitamin E, ferulic acid and the like. It has been found that by using the additive together, it is possible to remarkably suppress the decrease in the a value of the blood muscle.
Further, in the measurement of the blood-muscle discoloration site ratio, as shown in FIG. 2, a tendency similar to the change in the a value was observed. That is, in the control group 1, the discolored part started to increase gradually from 24 hours after storage, and about 90% discolored 192 hours after the end of the measurement. In the control group 2, since palm oil was replaced with fish oil, the progress of the discoloration was slightly suppressed as compared with the control group 1, but still 60% or more of the color was finally changed. On the other hand, in the test group 1 in which the amounts of vitamin C and vitamin E were respectively shown in Table 1, discoloration of bloody muscles was remarkably suppressed, and the discoloration site ratio after 192 hours was only about 25%.
FIG. 3 shows changes in the a-value of the blood muscles over time as in FIG. 1, but the storage condition in FIG. 1 is a low temperature of 4.5 ° C. and is a dark room. Unlike the conditions at retail stores, it took a considerable amount of time for the discoloration to proceed. On the other hand, as a more realistic condition setting, the storage temperature was set to 10 ° C. It was set as the conditions which irradiate light. As a result, in the control groups 1 and 2, the a value gradually began to decrease after 6 hours from the start of storage, and in particular, a rapid decrease in the a value was observed after 10 hours. On the other hand, almost no decrease in the a value was observed in the test group 1 until the 10th hour, only a decrease was observed from the 10th to the 11th hours, and the effect of the present invention was remarkable.

(1) Breeding test 2 of yellowtail using fish feed
An EP feed having a diameter of 12 mm was prepared at a blending ratio shown in Table 3 and subjected to a breeding test. In Control Group 3, a mixture of fish oil and palm oil in a ratio of 7: 3 was used as the fat to be added. Control group 4 is obtained by increasing vitamin C and vitamin E by 239 ppm and 405 ppm, respectively, compared to control group 3. In test group 2, the mixture ratio of palm oil was increased to 50% with respect to fish oil, and vitamin C and vitamin E were increased by 239 ppm and 405 ppm, respectively, compared to control group 3. Furthermore, in test group 3, the mixing ratio of palm oil was increased to 70% with respect to fish oil, and vitamin C and vitamin E were increased by 239 ppm and 405 ppm, respectively.
Table 3 shows the contents of vitamin C and vitamin E in the test feed of each section.
Table 3 also shows the n-3HUFA content in the feed fats and oils in each section. Breeding was carried out for 63 days by accommodating 50 fishes (2 year old fish) each with an average fish weight of about 2,500 g in a 4 x 4 x 4 m synthetic fiber ginger (sea surface small ginger). The water temperature during the breeding period was 17.6-23.6 ℃.

(2) Results of breeding tests (bred results)
The breeding results are shown in Table 4. All the wards grew steadily without any drowning during the breeding period. That is, the average fish weight at the end was 3.2 to 3.3 kg in all groups, and the growth rate was 129 to 135%, which was lower overall compared to Example 1, but the test group was equivalent to the control group. Somewhat good growth was shown. Although the wall-thickening factor generally shows a higher tendency than that of Example 1, there was no particular difference between the control group and the test group as in Example 1. The daily feeding rate showed almost the same tendency as in Example 1, which was 1.3% bw / day in the control group 3, whereas the test groups 2 and 3 were slightly higher at 1.4% bw / day.
From these results, in this Example 2, there was no adverse effect on the breeding performance by replacing fish oil with palm oil, but rather showed a good trend, but breeding for 63 days when the water temperature decreased Due to the time period and slight variation in the results in the test section, it seems that the results are substantially equivalent.

(3) Evaluation of degree of discoloration Next, among these test fish, three fish of relatively uniform size from each ward were squeezed on the sea after the breeding test was completed, and the fish meat was made into a block shape by quickly reducing it to three. It was cut out, housed in a sealed container and stored in a dark place at 4.5 ° C., and the red color (a value) of the blood muscle was measured with a color difference meter (CR-200 manufactured by Minolta Co., Ltd.) over time. The results are shown in FIG. Further, using the same sample, the blood clot muscle surface was captured by a scanner, and the ratio of the discolored portion to the blood clot muscle surface area by image processing was calculated. The results are shown in FIG.
In the measured value of the a value by the color difference meter shown in FIG. 4, the value of the control group 3 began to gradually decrease after 24 hours and thereafter decreased significantly. On the other hand, in the control group 4 in which vitamin C and vitamin E were strengthened relative to the control group 3, the a value tended to be maintained after 48 hours, and clearly changed to a higher value than the control group 3. However, also in the control group 4, the a value began to decrease rapidly after 72 hours, and after 144 hours, the value became equal to the control group 3. In Test Group 2 and Test Group 3 in which the replacement rates of fish oil and palm oil were 50% and 70%, respectively, the values clearly showed a tendency to be maintained higher than those in Control Groups 3 and 4.

  In addition, the measurement result of the blood muscle discoloration site ratio shown in FIG. 5 was almost the same as the time-dependent change of the a value, and the control group 3 was discolored earliest. In control group 4 enriched with vitamin C and vitamin E, discoloration of blood clots was observed to be suppressed. Furthermore, as in test groups 2 and 3, the substitution rate of fish oil and palm oil was set to 50% or more. It became clear that further discoloration was suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the cheap feed for yellowtail which improved the effect which prevents time-dependent discoloration of the blood muscle after fillet processing cooking especially in yellowtail which has remarkable discoloration of blood muscle among cultured fish. Therefore, it is useful as a feed for improving meat quality for yellowtail.

In Example 1, the measurement result of the a value of the blood muscle in each section in the dark is shown with time. In Example 1, the ratio which the discoloration site | part area of the blood muscle in each division occupies is shown with time. In Example 1, the measurement result of the blood muscle a value in each section under fluorescent lamp irradiation is shown with time. In Example 2, the measurement result of the a value of the blood muscle in each section is shown with time. In Example 2, the ratio which the discoloration site | part area of the blood-skinned muscle occupies in each section is shown with time.

Claims (2)

  A feed for yellowtail containing 20% or more of fats and oils, and the proportion of n-3 highly unsaturated fatty acids in the fatty acid composition of the fats and oils in the feed is less than 15%, 8% or more, and antioxidant Feed for yellowtail containing at least 300 ppm and less than 1000 ppm vitamin C and 300 ppm and less than 700 ppm vitamin E as active substances. A feed for yellowtail containing 20% or more of fats and oils, and the proportion of n-3 highly unsaturated fatty acids in the fatty acid composition of the fats and oils in the feed is less than 15%, 8% or more, and antioxidant Meat color improvement of yellowtail characterized by feeding a feed for yellowtail containing at least 300 ppm to less than 1000 ppm vitamin C and 300 ppm to less than 700 ppm vitamin E as active substances for a period of from 1 month to 3 months Method.

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