Method for regulating and controlling meat quality of weever by changing salinity of feeding environment

Abstract

The invention discloses a method for regulating and controlling meat quality of weever by changing feeding environment salinity, and relates to the technical field of fish culture, the method comprises the following steps: step 1, selecting feeding objects and feeding environment: selecting juvenile weever which is robust in physique and uniform in specification as experimental objects, and equally dividing the selected experimental objects into two groups, one group is an experimental group, and the other group is a control group; 2, measuring the water quality of the culture ponds: detecting the salinity and other parameters of the culture ponds by using a water quality testing tool, and ensuring that the initial parameters of the two groups of culture ponds are consistent; 3, selectively adding salt specially used for the culture pond or introducing high-salinity natural seawater in proportion; and 4, calculating the addition amount. According to the method, the salinity of the water body after the weever passes through the fry stage is larger than that of the water body in the fry stage, so that the muscle fiber density of the weever is reduced, the hardness and chewiness of fish meat are reduced, the fish meat is tender, juicy and good in taste, and the effect of regulating and controlling the meat quality of the weever is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fish breeding, and in particular to a method for regulating the meat quality of seven-star seabass by changing the salinity of a breeding environment. Background Art

[0002] The seven-star seabass, also known as the spotted seabass, is a euryhaline fish species that can grow in freshwater, brackish water and seawater aquaculture. During the aquaculture process, the suitable water salinity is usually below 5‰. This means that when aquaculture seven-star seabass, the salt concentration of the water body should be kept at 5 parts per thousand or less. When the salinity is higher than this level, the growth rate of the seven-star seabass may become slow. The muscle growth of the seven-star seabass is mainly concentrated in the middle and late stages of its growth. In the early development stage, the energy of the seven-star seabass is mainly used to support its life activities and organ development, while muscle growth is relatively slow. As the seven-star seabass grows, its energy distribution gradually shifts to muscle growth, and muscle tissue begins to develop rapidly.

[0003] It is known that the muscle fibers of fish have an important influence on its taste. The thickness, density, length and distribution of muscle fibers will affect the tenderness, juiciness, taste and other quality indicators of fish. Generally speaking, fish with fine muscle fibers, moderate density and appropriate length taste better and are more tender, while fish with thick muscle fibers and excessive density taste rougher and are less tender. In addition, changes in the microstructure of muscle fibers will also affect the texture of fish. For example, the smaller the diameter of the muscle fibers, the stronger the ability to scatter light, and the brighter the color of the meat.

[0004] At present, in order to promote the muscle growth of seven-star seabass in aquaculture management, a series of measures are usually taken, including providing high-protein feed, maintaining appropriate water temperature and water quality, and controlling the aquaculture density. These measures help optimize the growth environment of seven-star seabass and promote its muscle growth. However, the muscle fibers of seven-star seabass raised under this aquaculture model are thick and dense, resulting in high hardness, strong chewiness, and poor taste of the seven-star seabass meat. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment, so that the salinity of the water after the seven-star seabass passes the seedling stage is greater than the salinity of the water during the seedling stage, so as to reduce the muscle fiber density of the seven-star seabass, reduce the hardness and chewiness of the fish meat, make the fish meat tender, juicy and have a good taste, and achieve the effect of regulating the meat quality of the seven-star seabass.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment, comprising the following steps:

[0007] Step 1: Select the feeding subjects and feeding environment: Select the seven-star seabass juveniles with strong physique and uniform size as the experimental subjects, and divide the selected experimental subjects into two groups, one group is the experimental group and the other group is the control group;

[0008] Select a number of breeding ponds of the same size and divide them into two groups, named experimental pond group and control pond group, and put the selected experimental objects into the two groups of breeding ponds respectively;

[0009] Step 2: Measure the water quality of the breeding pond: Use water quality testing tools to detect the salinity and other parameters of the breeding pond to ensure that the initial parameters of the two groups of breeding ponds are consistent;

[0010] Step 3: Choose to add salt specially used for aquaculture ponds or introduce high-salinity natural seawater in proportion;

[0011] Step 4: Calculate the amount to be added: During the fry period of the seven-star seabass, the salinity of the experimental pond water is maintained at 4-5‰. After the fry pass the fry period, the salinity of the water is reduced to keep it between 1-2‰. Then, according to the volume of the breeding pond and the required salinity, calculate the amount of salt required to be added for the growth of the fry at each stage or the amount of high-salinity natural seawater that needs to be introduced;

[0012] Step 5, adding in batches: adding salt in batches to the breeding pond named experimental pond to ensure that the added salt is evenly dissolved in the pond water and avoid causing harm to the seven-star sea bass;

[0013] Step 6. After adding salt, perform routine maintenance work:

[0014] S1. Regularly monitor the salinity and other water quality parameters of the aquaculture pond, and adjust the amount of salt added in a timely manner according to the test results to maintain the appropriate salinity;

[0015] S2. Change the water in the two groups of breeding ponds regularly to keep the water clarity above 25cm;

[0016] S3. Start the aerators for the two groups of breeding ponds in a timely manner to ensure that the water in the ponds has sufficient dissolved oxygen;

[0017] Step 7. After the seven-star seabass in the two groups of breeding ponds grow to 1.5 kg, they are randomly salvaged and sampled for meat quality testing.

[0018] Preferably, in step 1, the length of the fry of seven-spotted sea bass is 8±3 cm and the weight is 3±1 g.

[0019] Preferably, the pool opening area of ​​the two groups of breeding ponds selected in step 1 is 15hm 2 The pond depth is 2.5-3m, and 5,000 fish fry are put into each breeding pond.

[0020] Preferably, the aquaculture pond parameters detected in step 2 include but are not limited to pH value, ammonia nitrogen content, and nitrate content.

[0021] Preferably, the frequency of changing the water in the culture pond in S2 of step six is ​​once every 2-3 days.

[0022] Preferably, the aerator in step 6 S3 is started at a frequency of 1-2 hours of oxygenation at noon on a sunny day, and is started at night or early morning on a rainy day or thunderstorm day.

[0023] Preferably, the detection items in step seven are to detect the texture comparison of seven-star seabass meat, the detection of fish flavor amino acids, the detection of fish pH value, the determination of fish freezing exudation rate, the determination of fish cooking loss rate, and the determination of basic nutritional components of fish.

[0024] Preferably, the texture comparison test item is used to test the shear force, resilience, hardness and chewiness of fish meat;

[0025] The determination of the basic nutritional components of fish meat includes the determination of crude protein, crude fat, moisture and crude ash of fish meat.

[0026] Compared with the prior art, the present invention provides a method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment, which has the following beneficial effects:

[0027] The invention adjusts the salinity of the water in which the seven-star seabass grows, and makes the salinity of the water after the seven-star seabass passes the seedling stage greater than the salinity of the water during the seedling stage, so as to reduce the muscle fiber density of the seven-star seabass, reduce the hardness and chewiness of the fish meat, make the fish meat tender, juicy and have a good taste, and achieve the effect of regulating the meat quality of the seven-star seabass. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with specific embodiments.

[0029] The present invention provides a method for regulating the meat quality of seven-star seabass by changing the salinity of a breeding environment, comprising the following steps:

[0030] Step 1, select the breeding subjects and breeding environment: select the seven-star seabass juveniles with strong physique and uniform size as the experimental subjects, the seven-star seabass juveniles are 8±3cm in length and 3±1g in weight, and divide the selected experimental subjects into two groups, one group is the experimental group and the other group is the control group;

[0031] Select several breeding ponds of the same size and divide them into two groups, named experimental pond group and control pond group. Put the selected experimental objects into the two groups of breeding ponds respectively. The pool area of ​​the two groups of breeding ponds is 15hm 2, the pond depth is 2.5-3m, the selected experimental subjects are put into two groups of breeding ponds, and 5000 fry are put into each breeding pond;

[0032] Step 2. Measure the water quality of the breeding pond: Use water quality testing tools to detect the salinity and other parameters of the breeding pond. Other parameters include but are not limited to pH value, ammonia nitrogen content, nitrate content, etc., to understand the water quality of the water in the two groups of breeding ponds. At the same time, it can also ensure that the initial parameters of the two groups of breeding ponds are consistent and control the experimental variables.

[0033] Step 3: Choose to add salt specially used for aquaculture ponds or introduce high-salinity natural seawater in proportion;

[0034] The salt used for fish farming is often obtained through natural evaporation or simple processing, retaining more minerals and impurities, while ordinary table salt is extracted from salt mines and is finely processed to remove most impurities and minerals. Ordinary table salt is mainly used for seasoning and food preservation, while the salt used for fish farming is mainly used to regulate water quality, provide necessary minerals, and serve as a disinfectant. In addition, some specific minerals may be added to the salt used for fish farming, such as magnesium, potassium, zinc, etc., to improve the prevention and treatment of fish diseases. These ingredients are also not found in ordinary table salt.

[0035] Step 4. Calculate the amount to be added: During the fry stage of the seven-star seabass, maintain the salinity of the experimental pond water at 4-5‰. After the fry have passed the fry stage, reduce the salinity of the water to keep it between 1-2‰. Then, based on the volume of the breeding pond and the required salinity, calculate the amount of salt needed to be added for the growth of the fry at each stage or the amount of high-salinity natural seawater that needs to be introduced.

[0036] Step 5, adding in batches: Add salt in batches to the breeding pond named experimental pond to ensure that the added salt is evenly dissolved in the pond water and avoid causing harm to the seven-star sea bass;

[0037] Step 6. After adding salt, perform routine maintenance work:

[0038] S1. Regularly monitor the salinity and other water quality parameters of the aquaculture pond, and adjust the amount of salt added in a timely manner according to the test results to maintain the appropriate salinity;

[0039] S2. Change the water in the two breeding ponds regularly, every 2-3 days, to keep the water clarity above 25cm;

[0040] S3. Start the aerator for the two groups of breeding ponds in time, add oxygen for 1-2 hours at noon on sunny days, and start it in the evening or early morning on rainy days or thunderstorms to ensure that the pool water has sufficient dissolved oxygen;

[0041] Step 7. After the seven-star seabass in the two groups of breeding ponds grow to 1.5 kg, they are randomly salvaged and sampled for meat quality testing.

[0042] Six ponds were randomly selected from the brackish and freshwater soil pond breeding base of Niutianyang Town Aquatic Industrial Park in Jinping District, Shantou City as the experimental group breeding ponds. Each pond has an average of about 15hm 2 , 50,000 / hm 2 According to the above steps, 5,000 fish fry were put into six ponds respectively. The weight of seven-star sea bass fry and striped sea bass fry was about 3g / fish. After they reached a weight of about 1.5kg, they were salvaged and sampled.

[0043] At the same time, six ponds in Raoping District of Chaozhou City were used as the control group breeding ponds, and the same number and weight of sea bass as those in the above experimental group were salvaged for testing.

[0044] 1) Determination of fish meat texture characteristics:

[0045] One fish was selected from each pond, and the dorsal fin meat of the sea bass was cut into 2cm×1cm×1cm pieces, placed in a sealed bag and placed on ice. After all the pieces that needed to be tested were packed, they were all put on the machine for testing. After the surface moisture was absorbed with filter paper, the hardness, elasticity, viscosity, brittleness, chewiness and shear force of the dorsal fin meat of the sea bass under different breeding environments were measured using the TPA mode of the texture analyzer. The test rate was 1mm / s and the compression percentage was 35%. The test results are shown in Tables 1 and 2 below:

[0046] Table 1

[0047]

[0048]

[0049] Table 2

[0050]

[0051] It can be directly seen from the data recorded in Table 1 and Table 2 that the shear force and resilience of the fish meat in the experimental group are smaller than those in the control group, and the muscle hardness and chewiness of the fish meat in the experimental group are lower than those in the control group, that is to say, the fish meat of the seven-star seabass cultured by the present invention is tender, juicy and delicious, and has a better taste.

[0052] 2) The flavor of fish meat mainly depends on the content of umami flavor amino acids in the free amino acids of the muscle, mainly including aspartic acid, threonine, alanine, cysteine, and leucine;

[0053] In addition, one fish was selected from each pond, and the contents of aspartic acid, threonine, alanine, cysteine, and leucine in the fish meat of the two groups were measured. The measurement results are shown in the following table:

[0054] Table 3

[0055]

[0056]

[0057] Table 4

[0058]

[0059] Table 5

[0060]

[0061] Table 6

[0062]

[0063] Table 7

[0064]

[0065]

[0066] It can be seen from the data in Tables 3 to 7 above that the contents of aspartic acid, threonine, alanine, cysteine ​​and leucine in the fish meat of the experimental group are higher than those in the control group, indicating that the fish meat of the experimental group is more delicious, that is to say, the method provided by the present invention is helpful to obtain seven-star seabass with more delicious meat.

[0067] 3) Determination of pH value of fish meat:

[0068] Catch one fish from each of the experimental and control group ponds, weigh 2 g of sea bass dorsal fin meat and put it into a meat grinder, add 18 mL of 0.85% saline into the meat grinder, homogenize and vortex appropriately, then centrifuge at 5000 r / min for 2 min, and use a pH meter to measure the pH value of the supernatant. Each sample needs to be measured 3 times, and the average of the three pH values ​​is taken as the final value.

[0069] Table 8

[0070]

[0071] Table 9

[0072]

[0073]

[0074] It can be seen from Table 7 and Table 8 above that the pH value of the fish meat in the experimental group is lower than the pH value of the fish meat in the control group.

[0075] 4) Determination of fish drip loss rate:

[0076] One fish was caught from each of the experimental and control group ponds. The dorsal fin meat of the sea bass was cut into 3cm×2cm×2cm strips and weighed. The weight m1 and time T1 were recorded. The strips were then placed in a sealed bag and placed on ice. After all the strips that needed to be tested for drip loss rate were packed, they were hung together. The specific method was to first use a bamboo stick to pass through the side wall of the paper cup → strips → the other side wall of the paper cup in sequence, prop up the strips in the paper cup, and ensure that the strips do not touch the bottom of the paper cup. Then, a sealed bag was placed over the paper cup and the sealing strip was tightened. Then, the strips were placed in a 4°C refrigerator and taken out after 24 hours. Finally, the moisture on the surface of the strips was absorbed with absorbent paper, and the strips were weighed again and the weight m2 was recorded. Drip loss rate (%) = (m1-m2) / m1×100%.

[0077] Table 9

[0078]

[0079] Table 10

[0080]

[0081]

[0082] It can be seen from the calculated data in Table 9 and Table 10 that the drip loss rate of the fish meat in the experimental group is greater than the drip loss rate of the fish meat in the control group.

[0083] 5) Determination of fish freezing exudation rate:

[0084] Select 5 breeding ponds from the experimental group pond and the control group pond respectively, catch 1 fish from each breeding pond, cut the dorsal fin meat of the sea bass into pieces of about 5g, record the weight m1 and time T1, put the pieces of meat in a sealed bag and place them on ice. After all the pieces of meat that need to be tested for freezing exudation rate are packaged, put them in a refrigerator at -20℃ for 24 hours, then take them out and thaw them at room temperature. When the center temperature of the meat pieces rises to 2-3℃, take the meat pieces out of the sealed bag, use absorbent paper to absorb the moisture on the surface of the meat pieces, and accurately weigh the mass m2. Freezing exudation rate (%) = (m1-m2) / m1×100%.

[0085] Table 11

[0086]

[0087] Table 12

[0088]

[0089]

[0090] From the data in Tables 11 and 12 above, it can be seen that the freezing exudation rate of the fish meat in the experimental group is greater than the freezing exudation rate of the fish meat in the control group.

[0091] 6) Determination of fish cooking loss rate:

[0092] Five breeding ponds were selected from the experimental group pond and the control group pond, and one fish was caught from each breeding pond. A 10g piece of sea bass dorsal fin meat was weighed, and the weight m1 was recorded and placed in a sealed bag on ice. Then, the meat was uniformly heated in a 75℃ water bath until the core temperature of the meat reached 75℃ and maintained for 10 minutes. The meat was taken out and cooled at room temperature for 30 minutes, and then weighed again and m2 was recorded. Cooking loss (%) = (m1-m2) / m1×100%.

[0093] Table 13

[0094]

[0095] Table 14

[0096]

[0097] It can be directly seen from Tables 13 and 14 above that the cooking loss rate of fish meat in the experimental group is greater than the cooking loss rate of fish meat in the control group.

[0098] 7) Determination of nutritional components of fish meat: including the determination of crude protein, crude fat, moisture and crude ash content of fish meat.

[0099] Five breeding ponds were selected from the experimental group ponds and the control group ponds, and one fish was caught from each breeding pond. Four fish pieces were taken from each fish and put into the following measurements.

[0100] 1. Referring to the determination of moisture in food in GB 5009.3-2016 national food safety standard, the moisture content in seabass dorsal fin meat was determined by direct drying method.

[0101] Table 15

[0102]

[0103] From the data in the above table, it can be concluded that the moisture content in the fish meat of the experimental group is higher than that in the fish meat of the control group.

[0104] 2. Referring to the determination of protein in food in GB 5009.5-2016 national food safety standard, the crude protein content in seabass dorsal fin meat was determined by sulfuric acid-catalyst digestion and Kjeldahl nitrogen determination method.

[0105] Table 16

[0106]

[0107]

[0108] From the data in the above table, it can be concluded that the crude protein content in the fish meat of the experimental group is lower than that in the fish meat of the control group.

[0109] 3. Refer to GB5009.6-2016 Determination of fat in food.2017. The Soxhlet extraction method was used to determine the crude fat content in the dorsal fin meat of sea bass.

[0110] Table 17

[0111]

[0112] From the data in the above table, it can be concluded that the crude fat content in the fish meat of the experimental group is lower than that in the fish meat of the control group.

[0113] 4. Referring to the determination of ash in food in the national food safety standard GB 5009.4-2016, the crude ash content in the dorsal fin meat of sea bass was determined by direct ashing method.

[0114] Table 18

[0115]

[0116]

[0117] From the data in the above table, it can be concluded that the crude ash content in the fish meat of the experimental group is lower than that in the fish meat of the control group.

[0118] 8) Select one fish from each pond, cut about 2g of meat sample from the same position of the dorsal fin meat on the same side of each fish, mark it and put it into liquid nitrogen for quick freezing, and then extract RNA from the fish meat sample and construct library for sequencing. The specific operation is as follows:

[0119] RNA from the total sample was isolated and purified using TRIzol (Invitrogen, CA, USA) according to the manufacturer's protocol.

[0120] NanoDrop ND-1000 (NanoDrop, Wilmington, DE, USA) was used to control the quantity and purity of total RNA. The integrity of RNA was then tested using Bioanalyzer 2100 (Agilent, CA, USA) and verified using agarose electrophoresis. Concentrations > 50 ng / μL, RIN values ​​> 7.0, OD260 / 280 > 1.8, and total RNA > 1 μg met the requirements for downstream experiments. Oligo (dT) magnetic beads (Dynabeads Oligo (dT), catalog number 25-61005, ThermoFisher, USA) were used to specifically capture mRNA containing Poly A (polyadenylic acid) through two rounds of purification. The captured mRNA was purified under high temperature using a magnesium ion fragmentation kit ( Magnesium RNA Fragmentation Module, Catalog No. E6150S, USA) for fragmentation at 94°C for 5-7 minutes. The fragmented RNA was reverse transcriptase (Invitrogen SuperScript TM cDNA was synthesized under the action of E. coli DNA polymerase I (NEB, product number m0209, USA) and RNase H (NEB, product number m0297, USA). The double-stranded DNA and RNA were converted into double-stranded DNA by using E. coli DNA polymerase I (NEB, product number m0209, USA) and RNase H (NEB, product number m0297, USA). At the same time, dUTP Solution (Thermo Fisher, product number R0133, CA, USA) was added to the double-stranded DNA to fill the ends of the double-stranded DNA into flat ends. Then an A base was added to each end to enable it to be connected to the adapter with a T base at the end, and then the size of the fragment was screened and purified using magnetic beads. The second strand was digested with UDG enzyme (NEB, catalog number m0280, MA, US), and then PCR was performed - pre-denaturation at 95°C for 3 minutes, denaturation at 98°C for a total of 8 cycles for 15 seconds each, annealing at 60°C for 15 seconds, extension at 72°C for 30 seconds, and finally extension at 72°C for 5 minutes to form a library with a fragment size of 300 bp ± 50 bp. Finally, we used the illumina Novaseq TM The double-end sequencing was performed by ELISA 6000 (LC BioTechnology CO., Ltd. Hangzhou, China) according to standard operation, and the sequencing mode was PE150. The data shown in Table 18 were obtained.

[0121] Table 18

[0122]

[0123]

[0124] Note: “up” indicates that the expression level of the differential gene in the experimental group is upregulated; “down” indicates that the expression level of the differential gene in the control group is downregulated.

[0125] The present invention integrates the transcriptome data of the sea bass back muscle of the experimental group and the control group, and identifies a total of 360 differentially expressed genes (DEGs), of which 137 DEGs are upregulated and 223 DEGs are downregulated. Table 18 above shows the top 10 genes with the highest up-down-regulation ratio, among which genes related to the cytoskeleton (TNNT2, Tnni1, des), genes related to amino acid transport and metabolism (CKM), and genes related to lipid transport and metabolism (ACSS2) are all significantly upregulated (P < 0.05), genes related to signal transduction mechanisms (Dyrk2, DUSP16, Sbk2, LMTK2), and genes related to intracellular transport, secretion and vesicle transport (PMP22, MPZ, GAL3ST1) are all significantly downregulated (P < 0.05).

[0126] Conclusion: The salinity of brackish water aquaculture environment significantly affected the pathways of signal transduction, material transport and nutrient metabolism of sea bass, up-regulated the expression of genes related to nutrient metabolism, and down-regulated the expression of genes related to transmembrane transport of substances.

[0127] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment, characterized in that: The following steps are involved: Step 1: Select the feeding subjects and feeding environment: Select the seven-star seabass juveniles with strong physique and uniform size as the experimental subjects, and divide the selected experimental subjects into two groups, one group is the experimental group and the other group is the control group; Select a number of breeding ponds of the same size and divide them into two groups, named experimental pond group and control pond group, and put the selected experimental objects into the two groups of breeding ponds respectively; Step 2: Measure the water quality of the breeding pond: Use water quality testing tools to detect the salinity and other parameters of the breeding pond to ensure that the initial parameters of the two groups of breeding ponds are consistent; Step 3: Choose to add salt specially used for aquaculture ponds or introduce high-salinity natural seawater in proportion; Step 4: Calculate the amount to be added: During the fry period of the seven-star seabass, the salinity of the experimental pond water is maintained at 4-5‰. After the fry pass the fry period, the salinity of the water is reduced to keep it between 1-2‰. Then, according to the volume of the breeding pond and the required salinity, calculate the amount of salt required to be added for the growth of the fry at each stage or the amount of high-salinity natural seawater that needs to be introduced; Step 5, adding in batches: adding salt in batches to the breeding pond named experimental pond to ensure that the added salt is evenly dissolved in the pond water and avoid causing harm to the seven-star sea bass; Step 6. After adding salt, perform routine maintenance work: S1. Regularly monitor the salinity and other water quality parameters of the aquaculture pond and adjust the amount of salt added to maintain the salinity based on the test results; S2. Change the water in the two groups of breeding ponds regularly to keep the water clarity above 25cm; S3, turn on the aerators for the two groups of breeding ponds to ensure that the water in the ponds has sufficient dissolved oxygen; Step 7. After the seven-star seabass in the two groups of breeding ponds grow to 1.5 kg, they are randomly salvaged and sampled for meat quality testing.

2. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 1, characterized in that: In step 1, the body length of the seven-star seabass fry is 8±3 cm and the weight is 3±1 g.

3. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 1, characterized in that: The two groups of breeding ponds selected in step 1 have an area of ​​15hm2. 2 The pond depth is 2.5-3m, and 5,000 fish fry are put into each breeding pond.

4. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 1, characterized in that: The aquaculture pond parameters detected in step 2 include but are not limited to pH value, ammonia nitrogen content, and nitrate content.

5. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 1, characterized in that: The frequency of changing water in the breeding pond in S2 of step six is ​​once every 2-3 days.

6. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 1, characterized in that: The start-up frequency of the aerator in S3 of step six is ​​1-2 hours of aeration at noon on a sunny day, and it is turned on at night or early morning on a rainy day or thunderstorm day.

7. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 1, characterized in that: The testing items in step seven are to compare the texture of seven-star seabass meat, to test the flavor amino acids of fish meat, to test the pH value of fish meat, to measure the freezing exudation rate of fish meat, to measure the cooking loss rate of fish meat, and to measure the basic nutritional components of fish meat.

8. The method for regulating the meat quality of seven-star seabass by changing the salinity of the breeding environment according to claim 7, characterized in that: The texture comparison test item is used to test the shear force, resilience, hardness and chewiness of fish meat; The determination of the basic nutritional components of fish meat includes the determination of crude protein, crude fat, moisture and crude ash of fish meat.

Images