JP2018029616A - Feed for cultured fish and breeding method of cultured fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide feed for cultured fish which can delay the discoloration of the red hue of dark muscle and ordinary muscle of cultured fish which have been processed by feeding the cultured fish, and to provide the cultured fish with delayed discoloration of the red hue of dark muscle and ordinary muscle after processing.SOLUTION: The invention relates to feed for cultured fish which can delay the discoloration of the red hue of dark muscle and ordinary muscle after processing by administering the same to the cultured fish and comprises a prescribed amount of citrus fruit and capsicum. Furthermore, the invention relates to a method of delaying the discoloration of the red hue of dark muscle and ordinary muscle after processing by administering a prescribed amount of citrus fruit and capsicum.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a feed given to cultured fish, particularly yellowtails, tuna and the like, which have a great influence on the commercial value of the red color of meat. The present invention also relates to a method for raising cultured fish such as yellowtails and tuna.

  When farmed fish is processed and distributed into fillets, fillets, sashimi, etc., the appearance of the processed product greatly affects consumers' willingness to purchase, but the color of the meat is particularly important. For example, the taste of meat is a big factor in determining the commercial value of fish because the taste of blood is great for the yellowtail and the red for the tuna and bonito, where the blood and ordinary muscle are bright red. It becomes a factor.

  The colors of blood and normal muscles change to sashimi, sushi, green onion, etc., and then gradually lose their redness and fade to brown. Therefore, even if the processed product is fresh, the economic value is significantly reduced when the red color is faded. This change is known to be a color change involving the methation of myoglobin, a chromoprotein contained in blood and normal muscles. In order to prevent the blood and normal muscles from turning brown, it is important to suppress the methation of myoglobin.

  Metoglobinization of myoglobin is caused by an oxidation-reduction reaction of iron atoms contained in heme coordinated with myoglobin. That is, when the cut surface comes into contact with air when preparing fillets etc., myoglobin changes from a reduced form to an oxygen form and temporarily shows a bright red color. Will come to present. The phenomenon that changes to meth-type myoglobin by this auto-oxidation is methation, and it delays the progress of methionization by administering components with antioxidant activity to cultured fish or applying them to processed fish meat Can do.

Patent Documents 1 and 2 describe that continuous feeding of yellowtail with vitamin C and vitamin E, which are vitamins having antioxidant activity, can suppress discoloration of blood muscle after processing and cooking. Has been. Patent Documents 3 and 4 describe that administration of a feed containing pepper makes it possible to prevent changes in the color tone of the blood muscles of yellowtail and common muscles of tuna. In Non-Patent Document 1, by feeding feed mixed with citrus squeezed rice cake to hamachi before shipment for about 20 days, aroma components derived from citrus were accumulated in the fish body, and the browning suppression effect of the fillet was recognized It is described. Patent Document 5 describes a method for suppressing color change of bloody meat obtained from a cultivated edible fish, characterized by feeding and culturing a cultured fish feed to which a spice is added.
There has been a need for further development of a more effective technique that can prevent the color change of farmed fish.

JP2002-233316 JP2005-278593 JP-A-11-266779 JP2005-27664 JP2004-254712

News from Ehime Prefectural Agriculture, Forestry and Fisheries Research Institute Issue 3 Page 1 (issued July 2010)

  This invention makes it a subject to provide the feed for cultured fish which can delay the discoloration of the red color tone of the blood muscle of a processed cultured fish and / or a normal muscle by feeding with respect to cultured fish. Moreover, this invention makes it a subject to provide the cultured fish which delayed the discoloration of the red color tone of the processed muscle and / or normal muscle.

The inventor of the present application, as a result of earnest research to solve the above-mentioned problem, delays the discoloration of the red color tone of the processed cultured fish by feeding to the cultured fish. The present invention has been completed by obtaining knowledge about the feed and method for cultured fish that can be used. The gist of the present invention is the following (1) to (14).
(1) The cultured fish feed comprising at least one kind of citrus fruit and at least one kind of pepper, wherein the weight ratio of the citrus fruit to pepper is 0.02 to 500.
(2) Feed for cultured fish containing 0.1 to 5.0% by weight of citrus fruits and 0.01 to 5.0% by weight of pepper.
(3) A feed for cultured fish containing 20 to 4000 ppm by weight of flavanones and 0.01 to 5.0% by weight of red pepper.
(4) A cultured fish feed comprising 0.1 to 5.0% by weight of citrus fruits and 0.3 to 200 ppm by weight of capsaicins and / or capsiates.
(5) Cultured fish feed containing flavanones of 20 to 400 weight 0 ppm and capsaicins and / or capsiates 0.3 to 200 weight ppm.
(6) The feed for cultured fish according to any of (3) and (5), wherein the flavanones are selected from the group consisting of hesperetin, naringenin, hesperidin and naringin.
(7) The feed for cultured fish according to any one of (4) to (6), wherein the capsaicins and / or capsiates are capsaicin.
(8) A method for raising cultured fish, wherein citrus fruits having a weight of 10 to 500 mg / kg body weight per day and chili pepper having a weight of 1 to 500 mg / kg body weight are administered for 3 to 30 days as the actual administration days.
(9) A method for raising cultured fish, characterized in that flavanones of 0.5 to 50.0 mg / kg body weight and capsicum of 1 to 500 mg / kg body weight are administered for 3 to 30 days as the actual administration days per day.
(10) A citrus fruit having a body weight of 10 to 500 mg / kg and a capsaicin and / or capsiate having a body weight of 5 to 10,000 μg / kg per day are administered for 3 to 30 days as the actual administration days. How to raise cultured fish.
(11) A flavanone of 0.5 to 50.0 mg / kg body weight per day and a capsaicin and / or capsiate of 5 to 10,000 μg / kg body weight are administered for 3 to 30 days as the actual administration days. How to raise cultured fish.
(12) The method according to any one of (9) and (11), wherein the flavanones are selected from the group consisting of hesperetin, naringenin, hesperidin and naringin.
(13) The method according to any one of (10) to (12), wherein the capsaicins and / or capsiates are capsaicin.
(14) A cultured fish bred by any one of the methods (8) to (13).

  By feeding the feed according to the present invention to the cultured fish, it is possible to effectively delay the red tone of the blood and / or normal muscle of the processed cultured fish from fading. Moreover, by the method according to the present invention, it is possible to provide a cultured fish in which the red color tone of processed blood and / or normal muscle is delayed.

The malondialdehyde (MDA) content (nmol / g meat) of the blood muscle in Example 1 is shown. In Example 2, the change of the blood muscle a * value when the fillet is refrigerated and stored is shown. In Example 2, the RSD (%) of the blood muscle a * value when the fillet was stored refrigerated for 24 hours is shown. The relative value of the MDA content of the blood muscle in Example 2 is shown. The change of the a * value of the blood muscle when the fillet is refrigerated in Example 3 is shown. In Example 3, the change of the Δa * value of the blood muscle when the fillet is refrigerated and stored is shown. The change of the C * value of the blood muscle when the fillet is refrigerated and stored in Example 3 is shown. In Example 3, the change of the ΔC * value of the blood muscle when the fillet is refrigerated and stored is shown. The measurement result of antioxidant activity in Example 4 is shown. The a * value at the time when the minced constrictor muscle in Example 5 was stored refrigerated for 24 hours is shown.

  In the present invention, `` citrus fruit '' is a fruit of a plant classified into the genus Citrus mandarin, and is not particularly limited, for example, Wenzhou mandarin, Ponkan, Tachibana, Mandarin orange, Kishu mandarin, Yuzu, Sudachi, kabosu, daidai, lemon, lime, bushukan, shikwasa, kobimikan, valencia orange, navel orange, grapefruit, iyokan, dekopon, hinata summer, sweet summer, hassaku, sweetie, buntan fruit, preferably Unshu mandarin orange, Ponkan, Tachibana, Mandarin orange, Kishu mandarin orange, Yuzu, Sudachi, Kabosu, Daidai, Lemon, Lime, Bushkan, Sikhwasa, Kumikakan fruit. In the present invention, two or more citrus fruits can be used in combination. Citrus fruits are often rich in flavanones such as naringenin and flavanone glycosides such as hesperidin.

  In the present invention, the citrus fruit can be the citrus fruit itself, an extract from the citrus fruit, etc., but from the viewpoint of workability in feed production it is possible to use a dried and processed powder. preferable. Although the whole fruit can be used for the citrus fruit, it is preferable to use an outer skin (outer pericarp or inner pericarp) and / or a thin skin part (carrot membrane). For the outer skin and thin skin of citrus fruits, the residue after processing citrus fruits into foods and beverages such as juices, canned foods and jams (hereinafter referred to as “residues after processing into foods and beverages”) It is suitable to use "residue". Citrus fruits may be contained in the cultured fish feed in an amount of 0.1 to 5.0% by weight (in terms of dry weight), but preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight. If citrus fruits are included in cultured fish feed in excess of 5.0% by weight, the aroma components of citrus fruits such as limonene will accumulate in the cultured fish, and the cultivated fish will produce a citrus odor. .

  In the present invention, “flavanones” are flavanones and flavanone glycosides often contained in citrus fruits, such as hesperetin, naringenin, citronetin, liquiritigenin, and these glycosides hesperidin, naringin, citronin. Liquiritin, preferably selected from the group consisting of hesperetin, naringenin, hesperidin and naringin. In the present invention, two or more of these may be used in combination. The flavanones may be extracted from citrus fruits, regardless of whether they are synthetic products, natural products, refined products, or mixtures. In the present invention, flavanones are contained in 1 kg of cultured fish feed in an amount of 20 to 4000 mg (in terms of dry weight. The weight expressed in mg of a compound contained in 1 kg of cultured fish feed is “weight ppm”). However, it is preferably 30 to 3000 ppm by weight, more preferably 40 to 2000 ppm by weight.

  In the present invention, “capsicum” is a plant belonging to the genus Capsicum. Plants of the genus Capsicum include capsicum, paprika, peppers and the like. Pepper, called a pungent species, contains pungent components (capsaicins and capsiates) that are the most characteristic of it.

  In the present invention, as the pepper, the pepper itself, the pepper powder, the pepper extract and the like can be used. Pepper may be contained in the cultured fish feed in an amount of 0.01 to 5.0% by weight (in terms of dry weight), preferably 0.03 to 4.0% by weight, and more preferably 0.1 to 3.0% by weight.

  In the present invention, “capsaicins and / or capsiates” means, for example, capsaicins such as capsaicin, dihydrocapsaicin, nordihydrocapsaicin, homodihydrocapsaicin, homocapsaicin, and the acid amide bond of these capsaicins substituted with an ester bond. Capsaiates having a structure, but capsaicin is preferred. In the present invention, two or more of these may be used in combination. Capsaicins and capsiates may be extracted from red pepper, regardless of whether they are synthetic products, natural products, purified products, or mixtures. In the present invention, capsaicins and / or capsiates may be contained in the cultured fish feed in an amount of 0.3 to 200 ppm by weight (in terms of dry weight), preferably 0.5 to 100 ppm by weight, more preferably 1.0 to 50 ppm by weight.

  A cultured fish feed comprising at least one citrus fruit and at least one kind of pepper according to the present invention, wherein the weight ratio of the citrus fruit to pepper is 0.02 to 500. The feed may be mixed so that the weight ratio of the dry weight of at least one citrus fruit to the dry weight of at least one kind of pepper is 0.02 to 500. Compared to the case where a diet containing either citrus fruits or capsicum is administered to a cultured fish, a feed containing both is given to the cultured fish, so that the blood and muscles of the processed cultured fish The effect of delaying the red color from fading can be enhanced.

  In the present invention, it is preferable to use a feed in consideration of nutritional components and physical properties required for each fish species. Usually, fish meal, starch, minerals, vitamins, fish oil, etc. are mixed into pellets, or powdered feed (mash) mixed with fish meal, vitamins, etc. and frozen fish such as sardines, etc. Is used. Citrus fruits, flavanones, capsicum, capsaicins or capsiates according to the present invention can be arbitrarily adjusted in the content of cultured fish feed by mixing with other raw materials before forming the cultured fish feed. It is also possible to add the shaped feed by immersing it in the extract. In the case of fish sensitive to the taste and odor of the compound, a decrease in the palatability of the feed can be prevented by a method such as coating. The feed according to the present invention may be administered once or multiple times per day.

  In another embodiment of the present invention, citrus fruits having a weight of 10 to 500 mg / kg body weight and capsicin and / or capsiates having a weight of 1 to 500 mg / kg body weight or 5 to 10,000 μg / kg body weight per day are provided. The cultured fish breeding method is characterized by being administered to cultured fish for 3 to 30 days as the actual administration days. Citrus fruits may be administered in the range of 10 to 500 mg per 1 kg of fish weight per day, preferably in the range of 15 to 400 mg, more preferably in the range of 20 to 300 mg, particularly preferably 30. Administered in the range of ~ 200 mg.

  In another embodiment of the present invention, 0.5 to 50.0 mg / kg body weight flavanones per day and 1 to 500 mg / kg body weight capsicum or 5 to 10,000 μg / kg body weight capsaicins and / or capsiates are provided. This is a method for raising cultured fish, characterized in that it is administered to cultured fish for 3 to 30 days as the actual administration days. The flavanones may be administered in the range of 0.5 to 50.0 mg per 1 kg of fish weight per day, preferably in the range of 0.8 to 40.0 mg, more preferably in the range of 1.0 to 30.0 mg.

  In the method for raising cultured fish according to the present invention, the pepper may be administered in the range of 1 to 500 mg per 1 kg of fish weight per day, preferably in the range of 2 to 300 mg, more preferably 3 to 100 mg. Administered in a range. In addition to citrus fruits and flavanones, the effect of delaying the discoloration of the red color of processed cultured fish's blood and / or normal muscles can be obtained in a short breeding period by administration of pepper. Is possible.

  In the farmed fish breeding method according to the present invention, capsaicins and / or capsiates may be administered in a range of 5 to 10,000 μg per 1 kg of fish weight per day, preferably in the range of 10 to 3000 μg, more Preferably it is administered in the range of 20-1000 μg. In addition to citrus fruits and flavanones, capsaicins and / or capsiates are administered in addition to the effect of delaying the fade of red color of processed cultured fish blood and / or normal muscles. Can be obtained during the breeding period.

  In the present invention, “actual administration days” means the day when citrus fruits, flavanones, capsicum, capsaicins or capsiates are actually administered (hereinafter referred to as “citrus fruits, flavanones, peppers, capsaicins or capsiates). "The day when is actually administered" is also referred to as "actual administration day"). The actual administration days may be 3 to 30 days, preferably 4 to 15 days, more preferably 5 to 10 days. The actual administration date may be consecutive days or may be spaced apart. In the case of an interval, the interval between the actual administration date and the next actual administration date is preferably within 3 days. The interval between the actual administration date and the next actual administration date need not be equal as long as it is within 3 days.

  In the method for raising cultured fish according to the present invention, the actual administration date of citrus fruits and the actual administration date of capsicum or capsaicins and / or capsiates are preferably the same day, but different days. May be. In the method for raising cultured fish according to the present invention, the actual administration date of flavanones and the actual administration date of capsicum or capsaicins and / or capsiates are preferably the same day, but on different days. There may be.

  The daily food intake is almost determined by the type and size of the fish, so the amount of flavanones, capsicum, capsaicins and capsiates converted to the above doses are mixed or added to the feed to produce cultured fish. Administer. In the method according to the present invention, the daily dose may be administered once or divided into several times.

  The timing for starting the administration of the feed for cultured fish and the use of the breeding method according to the present invention is not particularly limited, but can be started, for example, several weeks before shipment.

In the present invention, the cultured fish includes both marine fish and freshwater fish, and is a perch-shaped cultured fish that has a great influence on the commercial value due to the red color of the meat. Buri such Specifically, tunas, bonito acids. In particular, yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), striped jack (Pseudocaranx dentex), bluefin tuna (Thunnus orientalis), SBT (Thunnus effective in maccoyii ).

  Examples of the present invention will be described below, but the present invention is not limited thereto.

(Flavanone administration test)
A method for producing feed for cultured fish containing antioxidant components including feed production flavanones was shown. The composition of the raw materials was prepared as shown in Table 1. These raw materials were stirred uniformly (Mighty 50, Aikosha Mfg. Co., Ltd.) with a mixer, and dry pellets (DP) were granulated using a disk pelleter (Disk Pelleter, Dalton Co., Ltd.). At the time of granulation, 30% amount of water of the powder was added and pellets having a diameter of 5 mm were granulated. The pellets were used after drying with a dryer.
Test substances include capsaicin (purity> 60.0%), naringenin (purity> 90.0%), trans-ferulic acid (purity> 98.0%), hesperidin (purity> 90.0%), resveratrol (purity> 98%), catechin (Purity> 95%) was used. The test substance was purchased from Tokyo Chemical Industry Co., Ltd. The test substance was added after being dispersed in fish oil to 10 mg / g fish oil. Since fish oil is contained at 6.6% by weight in the feed, the content of the test substance in the feed is 660 ppm by weight. A group to which a feed using fish oil to which the test substance was not added was administered was used as a control group.

Breeding test using yellowtail Yellowtail with a body weight of 100 to 200 g was housed in a water tank with 3 fish in each test area. A diet of 1.25% of body weight was administered to yellowtail. Administration was carried out once a day for a total of 3 times in total, and the test fish was landed 24 hours after the last administration. After landing, the cutlery and medulla were cut with a kitchen knife and allowed to exsanguinate with ice-cold seawater. After thorough bleeding, the cells were stored in refrigerated foam stuffed with crushed ice. The sample was subjected to analysis 24 hours after refrigerated storage.

MDA measurement
MDA is a lipid peroxide that promotes methation and causes discoloration of the clot muscles. If the occurrence of MDA can be suppressed by administration of an antioxidant component, it is expected that the discoloration of the blood muscles can be delayed.
The MDA content of the constricted muscle was measured using a commercially available MDA measurement kit (TBARS assay kit, Cayman). Specifically, according to the manual attached to the kit, 1 g of blood muscle was homogenized with 10 times the amount of extraction buffer, and the supernatant was collected by centrifugation (4 ° C., 15000 rpm, 10 minutes). This was measured according to the manual.
The measurement results are shown in FIG. Compared to the control group, the MDA content of blood muscle was decreased in the test group administered with capsaicin, naringenin, ferulic acid, hesperidin, and catechin, but the values differed depending on the type of antioxidant component. From these results, it was inferred that these test substances have an action of suppressing the generation of MDA in blood muscles, and the effect obtained depends on the type of antioxidant component.

Measurement of Metoization Rate In order to evaluate the ease of progress of methionization in the blood-blind muscles to which each test substance was administered, the ratio of meth-type myoglobin to the total myoglobin (methotation rate) was measured by the following method. That is, 1 g of blood muscle was homogenized with ice-cooled distilled water, centrifuged, and the supernatant was collected. Adjust the pH of this supernatant to 7 with 0.1N aqueous sodium hydroxide solution, and measure the absorbance at 540nm and 503nm (ABS ₅₄₀ , ABS ₅₀₃ ) with an absorptiometer (U-3010, Hitachi High-Technologies Corporation). The ratio of absorbance (ABS ₅₄₀ / ABS ₅₀₃ ) was measured as a metation rate. Table 2 shows the relative values of each test group when the control group metation rate is 100.
The methotrelation rate of blood-blind muscles administered with an antioxidant component was lower than that of the control group, but varied depending on the type of antioxidant component. From this result, it was inferred that the effect of delaying the progress of methonation varies depending on the type of antioxidant component to be administered.

(Dose test of citrus fruits)
Feed production A feed for cultured fish containing processing residues such as vegetables and fruits was produced. Test feeds containing 0.3% by weight of various test substances listed in Table 3 were prepared in the same manner as in Example 1. The increase due to the addition of the test substance was adjusted by subtracting the amount of starch in Table 1. As a citrus fruit, a dried product of juice processing residue of citrus mandarin fruit (hereinafter referred to as “citrus processing residue”) was used, and a dried pepper powder was used as a pepper. The mandarin orange processing residue mainly includes the outer skin, inner skin, and fungi of the mandarin fruit.

Breeding test using yellowtail A yellowtail with a body weight of about 500 g was placed in a water tank with 3 fish in each test area. A diet of 1.25% by weight of the body weight was administered to yellowtail. Administration was performed once a day for a total of 6 times in total, and the test fish was landed 24 hours after the last administration. After landing, the cutlery and medulla were cut with a kitchen knife and allowed to exsanguinate with ice-cold seawater. After thorough bleeding, the cells were stored in refrigerated foam stuffed with crushed ice. The sample was subjected to analysis 48 hours after refrigerated storage.

Evaluation of the color tone of the blood muscle A fillet containing the blood muscle was prepared from yellowtail 48 hours after refrigerated storage. This was refrigerated at 4 ° C. in a humidified and sealed container. The color tone values (L * value, a * value, b * value) of the constricted muscle during refrigerated storage were measured over time using a color difference meter (CR-300, manufactured by Konica Minolta Optics). The L ^* a ^* b ^* color system is a method for expressing colors standardized by the International Commission on Illumination. In the L ^* a ^* b ^* color system, lightness is represented by L * values, and chromaticity is represented by a * values and b * values. When the L * value is positive, the brightness is strong, and when it is negative, it is dark. For a * value, plus indicates red and minus indicates green. When the b * value is positive, the yellow direction is indicated, and when the b * value is negative, the blue direction is indicated.
The measurement time was 0, 3, 6, 9, 24, and 36 hours after the fillet was prepared. Based on the measured tone value, the a * value indicating the intensity of red was compared with the RSD of the a * value at 24 hours after storage. RSD is a value expressed by the following equation, which means the degree of data variation. When RSD is large, the data variation is large.
RSD (%) = (standard deviation within group / additive average within county) x 100

The measurement result of a * value is shown in FIG. The a * value of the blood muscle was high during the preservation period of 24 to 36 hours by administering the feed containing the mandarin orange processing residue. From this result, it was inferred that the mandarin orange processing residue has an action to suppress the decrease of the blood muscle a * value.
FIG. 3 shows the RSD calculation result of the a * value at 24 hours after storage. Since the RSD value of the group fed with the feed containing citrus processed residue was low, it was speculated that the processed mandarin orange residue has the effect of suppressing variation in a * value and maintaining a stable color tone.

MDA measurement The MDA content of the blood muscle was measured in the same manner as in Example 1. The results are shown in FIG. As shown in FIG. 4, the MDA content of the group fed with the mandarin orange processing residue was lower than that of the group fed with other feeds. From this, it was speculated that the processed mandarin orange residue has an action to suppress the generation of MDA in the blood muscle.

(Combination test of citrus fruit and red pepper)
Feed production A feed for cultured fish containing both citrus fruits and pepper was produced. A feed containing 0.3% by weight of mandarin orange processing residue and dried pepper powder in the cultured fish feed (test feed) was prepared in the same composition as in Example 1 (citrus fruit / pepper weight ratio = 1), The group to which this test feed was administered was called a test group. The increase due to the addition of the test substance was adjusted by subtracting the amount of starch in Table 1. A control feed containing 0.3% by weight of dry pepper powder was administered to the control group.
The mandarin orange processing residue used for the feed production contained 5.3% by weight of hesperidin, and the dried pepper powder contained 0.2% by weight of capsaicin. Therefore, the feed administered to the test group contains 159 wt ppm hesperidin and 6 wt ppm capsaicin, and the feed administered to the control plot contains 6 wt ppm capsaicin. The hesperidin content in mandarin orange processed residue and the capsaicin content in dried pepper powder were measured by the High Performance Liquid Chromatography method at the Japan Food Analysis Center.

Breeding test using yellowtail A yellowtail with a body weight of about 450 g was placed in a water tank with 3 fish in each test area. Other test conditions were the same as in Example 2.

Daily intake of active ingredients per kg of yellowtail body weight Daily intakes of citrus fruits and red pepper per kg of yellowtail body weight were calculated. In the test area, the daily intake of citrus fruits and capsicum per individual was 38 mg / kg body weight. In the control group, the daily intake of capsicum per individual is the same as that in the test group.
Since the tangerine processing residue contained 5.3% by weight of hesperidin, the daily intake of hesperidin per individual in the test area was 2.0 mg / kg body weight.
Further, since the dried pepper powder contained 0.2% by weight of capsaicin, the daily intake of capsaicin in the test group or the control group was 75 μg / kg body weight.

According to the method described in Example 2, the color tone values of the blood muscles were measured at 0 hours, 3 hours, 6 hours, 9 hours, and 24 hours after preparation of the fillets. Based on the measured tone value, a * value indicating the intensity of red, Δa * value as the color difference from the control group, saturation (C * value) indicating vividness, and ΔC * value as the color difference from the control group The four indicators were compared. The C * value was calculated by the following formula.

The color difference Δa * was determined by subtracting the average of the a * values of the three individuals in the control group from the average of the a * values of the three individuals in the test group. The color difference ΔC * value was determined by subtracting the average of the C * values of the three individuals in the control group from the average of the C * values of the three individuals in the test group.
FIG. 5 shows a comparison result of a * values, and FIG. 6 shows a comparison result of Δa * values. Compared with the control group, the test group had higher blood muscle a * values during refrigerated storage, and the Δa * value was always a positive value. These results indicate that the red color during refrigerated storage is stronger in the test area.
The comparison results of C * values are shown in FIG. 7, and the comparison results of ΔC * values are shown in FIG. Compared to the control group, the test group had a higher C * value during refrigerated storage, and the ΔC * value was always a positive value. These results indicate that the test area maintains a more vivid color during refrigerated storage.
As described above, the combined use of citrus fruits and pepper made it possible to obtain the effect of delaying the discoloration of the processed muscle of the cultured fish even during the short administration period of 6 days.

(Comparison of antioxidant activity of feed)
Production of feed As described above, the phenomenon in which blood and normal muscles turn brown by auto-oxidation of myoglobin is affected by the antioxidant activity of components administered to farmed fish. Patent Document 5 states that “the change in color tone due to the oxidation of myoglobin is suppressed by the antioxidative action of the spice and a fresh red state is maintained” (page 5, line 29).
Therefore, the antioxidant activity of the test feed or control feed of Example 3 or the feed based on Table 1 of Patent Document 5 (comparative feeds 1 to 3) was measured. Table 4 shows the composition of each feed produced.

Antioxidant activity measurement method Antioxidant activity was measured by a method based on the reduction reaction of copper ions. For the measurement, a commercially available total antioxidant capacity assay kit (Biovision) was used. Specifically, 100 ml of ice-cold phosphate buffered saline (PBS) was added to 10 g of feed and homogenized, and then centrifuged (15,000 rpm, 4 ° C., 10 minutes), and the supernatant was collected. The supernatant diluted 20-fold with PBS was used as a measurement sample and measured according to the measurement manual of the total antioxidant capacity measurement kit. The antioxidant activity was calculated as a relative value with the value of the control feed as 100.

  The measurement results of the antioxidant activity are shown in FIG. The antioxidant activity of Comparative Feed 1 and Comparative Feed 2 was equivalent to that of the control group, but Comparative Feed 3 was slightly higher. The test feed was the most active.

(Evaluation of efficacy in vitro for blood color tone)
Evaluation method The effectiveness of various antioxidant components on the color of the joint muscle was evaluated in vitro by the following method. That is, 10 g of dried pepper powder, citrus processing residue, a mixture of dried pepper powder and citrus processing residue (dry weight ratio, dried pepper powder: citrus processing residue = 1: 3), or spices (1) to (4) in Table 4 100 ml of ice-cold PBS was added to (3) and stirred, and the supernatant obtained by centrifugation (15,000 rpm, 4 ° C., 10 minutes) was collected as a PBS extract.
The above-mentioned PBS extract was added at 0.3% by weight to a blood-bream muscle prepared in a minced shape using a food processor (MK-K48P, manufactured by Panasonic). Then, it preserve | saved for 24 hours at 4 degreeC, and measured the a * value after a preservation | save. In the negative control group, 0.3% by weight of PBS was added to the blood muscle. Table 5 shows the names of each test group.

  The measurement result of the a * value is shown in FIG. When each dried pepper powder or citrus processed residue was used alone, the a * value was higher than that of the negative control group, and it was shown that each dried pepper powder and citrus processed residue also has an effect of suppressing fading. The mixture obtained by mixing dried pepper powder and citrus processed residue in a ratio of 1: 3 had higher a * values than the case where dried pepper powder or citrus processed residue was used alone, and a synergistic effect was observed.

Claims (5)

  Suppression of fading of processed cultured fish containing at least one citrus fruit and at least one kind of pepper, the weight ratio of citrus fruit to pepper being 0.02 to 500 Feed for cultured fish such as yellowtail, tuna or bonito.   The feed for cultured fish according to claim 1, comprising 0.1 to 5.0% by weight of citrus fruit and 0.01 to 5.0% by weight of red pepper.   The feed for cultured fish according to claim 1, comprising 20 to 4000 ppm by weight of flavanones and 0.3 to 200 ppm by weight of capsaicins and / or capsiates.   Citrus fruits with a dry weight of 10-500 mg / kg body weight per day and capsicum with a dry weight of 1-500 mg / kg body weight are administered for 3-30 days as the actual administration days before shipment A method for breeding cultured fish of yellowtail, tuna, or skipjack, in which the blood and / or common muscles of the processed cultured fish are inhibited from fading.   The method for raising cultured fish according to claim 4, wherein flavanones having a weight of 0.5 to 50.0 mg / kg and capsaicins and / or capsiates having a weight of 5 to 10,000 µg / kg are administered per day.

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