Method for improving fish muscle quality by regulating intestinal microenvironment through neuroendocrine system

Abstract

The invention relates to the field of aquatic product muscle quality regulation and control. A method for improving muscle quality of fish by regulating intestinal microenvironment through a neuroendocrine system is characterized by comprising the following steps: 1) sterilizing a temporary rearing pond, injecting aerated water to 2 / 3 of the height of the temporary rearing pond, and regulating dissolved oxygen in the water to be 5.0-8.0 mg / L, water temperature to be 16-24 DEG C, pH to be 7.2-8.0 and ammonia nitrogen content to be lower than 0.5 mg / L by using an aerator; (2) adding a mixed input of 50-100 mg / L of lactobacillus brevis MN047 and 20-50 mg / L of lotus rhizome node extract into the water, and stirring to enable the mixed input to be uniformly dispersed; (3) putting fresh and alive freshwater fishes into the temporary rearing pond according to the rearing density of 20-30kg / m < 3 >, and fasting the fishes during temporary rearing; (4) temporary rearing; 5) waiting for detection in a refrigerator at-80 DEG C; (6) determining; and 7) analyzing the data. According to the method, the stress reaction can be relieved after fish stress, neurotransmitters are secreted, intestinal microbial flora is regulated, and then muscle quality deterioration caused by the stress reaction is relieved.

Description

Technical Field

[0001] The present invention relates to the field of aquatic product muscle quality regulation, and mainly relates to a method for improving muscle quality by regulating intestinal microenvironment through a neuroendocrine system. Background Art

[0002] In the fish industry chain, many important links may induce stress, such as breeding, fishing, transportation, slaughter, etc., which may cause physiological responses, oxidative damage, metabolic disorders in fish, and then cause muscle quality deterioration. The stress response comes from the activation of the central and fast-acting sympathetic-adrenal-medullary system, which releases norepinephrine from the sympathetic postganglionic nerves, epinephrine from the adrenal medulla, and the slower hypothalamus-pituitary-adrenal axis, and finally releases cortisol from the adrenal cortex. The release of cortisol hormone causes the sugar metabolism system in the blood to respond quickly, while activating the GR receptor body immune system response, affecting the homeostasis of intestinal microorganisms. There is a close connection between the communication between the central nervous system and the intestine and its microbiota mediated by the nervous, endocrine and immune systems, and this connection is bidirectional. The intestinal microbiota and bacterial metabolites are related to the activation of sympathetic and parasympathetic enteric neurons, immune cell activity, and the regulation of neurotransmitter and intestinal hormone production. The intestinal microbiota and skeletal muscle also affect each other. The imbalance of intestinal flora may increase oxidative inflammatory response, affect the homeostasis of energy synthesis and metabolism in mitochondria and muscles, and ultimately lead to changes in muscle quality. The hardness and water holding capacity of fish meat are important indicators for judging muscle quality. The shear force represents the good maintenance of fish meat hardness, and the pressurized water loss rate represents the water holding capacity of fish meat. The reduction of hardness and the decrease of water holding capacity will eventually cause the fish meat to be loose and have poor gloss, reducing its economic value. The fish itself has a weak ability to relieve stress. Stress caused by any link in the industrial chain process can easily cause the fish's neuroendocrine system to be imbalanced, the intestinal microbial homeostasis to be unbalanced, the muscle quality to deteriorate, and even cause the death of the fish. Therefore, from the perspective of neurotransmitters-intestinal microorganisms-muscle quality, the present invention provides a method for alleviating the deterioration of muscle quality caused by stress response by causing changes in intestinal microbial flora due to the rapid secretion of neurotransmitters. Summary of the invention

[0003] The purpose of the present invention is to provide a method for improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system, which can relieve stress response after fish stress, secrete neurotransmitters, regulate intestinal microbial flora, and thus alleviate the deterioration of muscle quality caused by stress response.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a method for improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system, characterized by comprising the following steps:

[0005] 1) After sterilizing the temporary holding pond, inject aerated water to 2 / 3 of the height of the temporary holding pond (the height of the temporary holding pond is 0.5-5m), use an aerator to adjust the dissolved oxygen in the water to 5.0-8.0 mg / L, the water temperature to 16-24°C, the pH to 7.2-8.0, and the ammonia nitrogen content to less than 0.5 mg / L;

[0006] 2) adding a mixture of 50-100 mg / L of Lactobacillus MN047 and 20-50 mg / L of lotus root node extract to water, and stirring to make it evenly dispersed;

[0007] 3) According to the breeding density of 20-30kg / m 3 Put fresh water fish into the temporary holding pond and fast the fish during the temporary holding period;

[0008] 4) The temporary culture period is 20-22 days (optimal is 21 days, which can be adjusted according to the condition of the fish). During the temporary culture period, 2 / 3 of the water volume should be replaced every day, and then the mixed inputs should be re-added, and the concentration of the mixed inputs should be adjusted to be consistent with step 2);

[0009] 5) After the temporary rearing is completed, the fresh-water fish is placed in a bucket containing 50 mg / L of anesthetic. After the fresh-water fish is completely anesthetized, the brain, midgut, muscle and other tissues are removed, and the fish are quickly packaged and quickly frozen in liquid nitrogen, and then placed in a -80°C refrigerator for testing;

[0010] 6) Using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to separate and determine neurotransmitters in brain tissue, using 16s bacterial diversity analysis to identify the microbial flora in the midgut, using a YYW-2 strain-controlled unconfined pressure instrument to determine the pressurized water loss rate of fish meat, and using a C-LM3B tenderizer to determine the shear force of fish meat;

[0011] 7) Analyze the data obtained in step 6) to determine the regulatory effect of the mixed input on the neurotransmitters, intestinal microorganisms and muscle quality of fresh freshwater fish; use correlation analysis to determine the correlation between neurotransmitters, intestinal microorganisms and muscle quality based on the correlation coefficient.

[0012] Furthermore, the temporary holding pond (or hanging water pond) in step 1) is a circular canvas pond with specifications of 8m in diameter, 1.5m in height and 1m in water level.

[0013] Furthermore, step 1) sterilizes the temporary holding pond by using 1 / 10000 volume of methylene blue to sterilize the temporary holding pond.

[0014] Furthermore, in step 1), the dissolved oxygen in the water is ensured to be 7.0-8.0 mg / L, the water temperature is 16-24° C., and the pH is 7.8-8.0.

[0015] Furthermore, in step 1), the ambient temperature is 17°C-24°C.

[0016] Furthermore, in step 2), a mixed input of 50-100 mg / L of Lactobacillus MN047 and 20-50 mg / L of lotus root node extract is added to the temporary holding pond and the mixture needs to be fully dissolved in water.

[0017] Furthermore, the bread lactobacillus MN047 in step 2) is a strain of bread lactobacillus MN047 that can produce multiple broad-spectrum bacteriocins and is screened from homemade mare's milk in Xinjiang, my country. The antibacterial metabolites of this strain can inhibit foodborne pathogens and regulate intestinal flora.

[0018] Furthermore, the lotus root node extract in step 2) is a mixture containing a certain amount of plant polyphenols extracted from lotus root nodes, and the extraction method is as follows: after the lotus root nodes are cut into pieces and ground into a paste, 0.15 mg / mL cellulase (50000 U / g) + pectinase (30000 U / g) (the mass ratio of cellulase to pectinase is 1:1) is used to extract at a temperature of 62°C and pH 4 for 90 minutes, and then centrifuged at 4000xg for 20 minutes, and the supernatant is collected as the crude extract; subsequently, preliminary alcohol precipitation is carried out with 60% ethanol and then purified with AB-8 macroporous resin. After freeze-drying, the total phenol concentration is measured to be 68.73 mg / 100 mg, thereby obtaining a lotus root node extract.

[0019] Furthermore, the fresh freshwater fish in step 3) is a special freshwater fish such as yellow catfish, rainbow trout, mandarin fish, largemouth sea bass, etc., which is healthy, in good shape, and has no damage on the body surface.

[0020] Furthermore, the fresh freshwater fish in step 3) are all edible adult fish, with the mass of yellow catfish being 300±10g, the mass of rainbow trout being 2000±115g, the mass of mandarin fish being 500±50g, and the mass of largemouth bass being 400±20g.

[0021] Furthermore, in step 3), each temporary holding pond is strictly in accordance with the breeding density of 20-30kg / m 3 Control the number of fish put in.

[0022] Furthermore, the concentration of the mixed input of Lactobacillus bread and polyphenol extract in step 4) is the same as that in step 2).

[0023] Furthermore, the molecular formula of the anesthetic in step 5) is ethyl m-aminobenzoate methanesulfonate (MS-222), molecular formula: C 10 H 15 NO5S.

[0024] Further, the specific method of determining the pressurized water loss rate in step 6) is as follows: cut a 4 cm × 4 cm gauze and weigh it (M0), weigh 2 ± 0.02 g of fresh freshwater fish meat (such as rainbow trout) sample and wrap it with gauze and weigh it (M1), place 8 filter papers of the same size on the top and bottom of the sample, place the fish meat wrapped sample in the middle position of the YYW-2 pressure plate, and adjust the pressure instrument to 145 Pa and keep it on the sample for 5 minutes; after the test, weigh the pressurized gauze and sample and record it as (M2); the pressurized water loss rate of the fish fillet is calculated using the following formula:

[0025]

[0026] Where: X——pressure water loss rate of the sample, %

[0027] M0——gauze mass, g;

[0028] M1——Total mass of gauze and sample before pressurization, g;

[0029] M2——Total mass of gauze and sample after pressurization, g.

[0030] Furthermore, in step 6), the specific method for measuring the shear force is: cutting the back muscles of the same part into long strips of similar shape and specification, clearing the instrument before measuring, and moving the blade downward at a uniform speed until the muscle is completely cut.

[0031] The beneficial effects of the present invention are:

[0032] (1) It effectively reduces the release of excitatory neurotransmitters in the brain caused by stress, while maintaining the homeostasis of the microbial flora in the midgut of fresh water fish, improving the proportion of beneficial microorganisms in the microbial flora, and alleviating the deterioration of muscle quality of fresh water fish caused by stress.

[0033] (2) The inlet water of the present invention uses aerated tap water to purify the physique of freshwater fish. Without feeding, the fish will excrete harmful substances such as feces in the body. A certain proportion of bread Lactobacillus MN047 and lotus root node extract are added to reduce the level of neurotransmitters in the brain, maintain the balance of intestinal microorganisms of freshwater fish, and improve the deterioration of muscle quality.

[0034] (3) The antibacterial metabolites of Lactobacillus MN047 can inhibit foodborne pathogens and regulate intestinal flora. Lotus root node extract has antioxidant and antibacterial effects. The combined use of the two can reduce the formation of oxygen free radicals in fish, improve the quality of freshwater fish meat, and reduce the loss of nutrients.

[0035] In summary, the combined use of Lactobacillus breadii MN047 and lotus root node extract provided in the present invention can reduce neurotransmitter secretion, maintain intestinal flora homeostasis, and alleviate muscle quality deterioration. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a graph of the relative levels of intestinal flora contained in the midgut of the fish of the present invention at the genus level.

[0037] Figure 2a This is a heat map of the correlation between fish neurotransmitters, intestinal flora and muscle quality at low addition levels (50 mg / L of Lactobacillus MN047 and 20 mg / L of lotus root node extract) in Example 2 of the present invention.

[0038] Figure 2b This is a heat map of the correlation between fish neurotransmitters, intestinal flora and muscle quality at high addition levels (100 mg / L of Lactobacillus MN047 and 50 mg / L of lotus root node extract) in Example 3 of the present invention.

[0039] Table 1 is a statistical table of neurotransmitters with significantly different expression levels in the fish brain of the present invention.

[0040] Table 2 is the fish muscle quality evaluation index of the present invention. DETAILED DESCRIPTION

[0041] In the following Examples 2-3, the lotus root node extract is a mixture containing a certain amount of plant polyphenols extracted from lotus root nodes, and the extraction method is as follows: the lotus root nodes are cut into pieces and ground into a paste, and then extracted with 0.15 mg / mL cellulase (50,000 U / g) + pectinase (30,000 U / g) (the mass ratio of cellulase to pectinase is 1:1) at 62°C and pH 4 for 90 minutes, and then centrifuged at 4000xg for 20 minutes, and the supernatant is collected as the crude extract; subsequently, preliminary alcohol precipitation is performed with 60% ethanol and then purified with AB-8 macroporous resin. After freeze-drying, the total phenol concentration is measured to be 68.73 mg / 100 mg, thereby obtaining a lotus root node extract.

[0042] In the following Examples 1-3, the molecular formula of the anesthetic is ethyl m-aminobenzoate methanesulfonate (MS-222), molecular formula: C 10 H 15 NO5S.

[0043] Example 1 (control group example)

[0044] A method for improving fish muscle quality by regulating the intestinal microenvironment through a neuroendocrine system comprises the following steps:

[0045] 1) Before use, sterilize the holding pond: sterilize the holding pond with 1 / 10000 volume of methylene blue;

[0046] After sterilizing the temporary holding pond, inject clean water into it (the temporary holding pond is 8m in diameter, 1.5m high, and the breeding density is about 30kg / m 3 The water depth is controlled at 1m. Before the live fish are put into the temporary holding pond, the water in the pond is aerated for one day, and the temporary holding pond is oxygenated with an aerator to ensure that the dissolved oxygen in the water is 7.0-8.0mg / L, the water temperature is 16-24℃, and the pH is 7.8-8.0;

[0047] 2) Randomly select 50 healthy, well-shaped, and undamaged largemouth bass weighing 400±20g and place them in a temporary holding pond. The stocking density is adjusted to 30kg / m 3 , no substance was added as the control group;

[0048] 3) The temporary rearing period is adjusted to 21 days, during which the water is changed once a day, and the amount of water changed is 2 / 3 of the original water;

[0049] 4) Fasting treatment is carried out during the entire holding period;

[0050] 5) After the temporary rearing is completed, the fresh largemouth bass is placed in a bucket containing 50 mg / L of anesthetic. After the fresh freshwater fish is completely anesthetized, professionals remove its brain, midgut, muscle and other tissues, quickly package them, and then quickly freeze them in liquid nitrogen, and then place them in a -80°C refrigerator for testing;

[0051] 6) Using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to separate and determine neurotransmitters in brain tissue, using 16s bacterial diversity analysis to identify the microbial flora in the midgut, using a YYW-2 strain-controlled unconfined pressure instrument to determine the pressurized water loss rate of fish meat, and using a C-LM3B tenderizer to determine the shear force of fish meat;

[0052] 7) Analyze the data obtained in 6) to determine the regulatory effect on neurotransmitters, intestinal microorganisms and muscle quality of fresh freshwater fish; use correlation analysis to determine the correlation between neurotransmitters, intestinal microorganisms and muscle quality based on the correlation coefficient.

[0053] Example 2

[0054] A method for improving fish muscle quality by regulating the intestinal microenvironment through a neuroendocrine system comprises the following steps:

[0055] 1) Before use, sterilize the holding pond: sterilize the holding pond with 1 / 10000 volume of methylene blue;

[0056] After sterilizing the temporary holding pond, inject aerated water into the temporary holding pond (the temporary holding pond is 8m in diameter, 1.5m in height, and the stocking density is about 30kg / m 3 The water depth is controlled at 1m. Before the live fish are put into the temporary holding pond, the water in the pond is aerated for one day, and the temporary holding pond is oxygenated with an aerator to ensure that the dissolved oxygen in the water is 7.0-8.0mg / L, the water temperature is 16-24℃, and the pH is 7.8-8.0;

[0057] 2) adding a mixture of 50 mg / L of Lactobacillus MN047 and 20 mg / L of lotus root node extract to water, and stirring to make it evenly dispersed;

[0058] 3) Randomly select 50 healthy, well-shaped, and undamaged largemouth bass weighing 400±20g and place them in a temporary holding pond. The stocking density is adjusted to 30kg / m 3 , the fish were fasted during temporary rearing; recorded as experimental group 1;

[0059] 4) The temporary rearing time is adjusted to 21 days, and the water is changed once a day during the temporary rearing period, and the amount of water changed is 2 / 3 of the original water volume; then the mixed inputs of step 2) are added again, and the concentration of the mixed inputs is adjusted to be consistent with that of step 2); fasting treatment is performed during the entire temporary rearing period;

[0060] 5) After the temporary rearing is completed, the fresh largemouth bass is placed in a bucket containing 50 mg / L of anesthetic. After the fresh freshwater fish is completely anesthetized, professionals remove its brain, midgut, muscle and other tissues, quickly package them, and then quickly freeze them in liquid nitrogen, and then place them in a -80°C refrigerator for testing;

[0061] 6) Using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to separate and determine neurotransmitters in brain tissue, using 16s bacterial diversity analysis to identify the microbial flora in the midgut, using a YYW-2 strain-controlled unconfined pressure instrument to determine the pressurized water loss rate of fish meat, and using a C-LM3B tenderizer to determine the shear force of fish meat;

[0062] 7) Analyze the data obtained in step 6) to determine the regulatory effect of the mixed input on the neurotransmitters, intestinal microorganisms and muscle quality of fresh freshwater fish; use correlation analysis to determine the correlation between neurotransmitters, intestinal microorganisms and muscle quality based on the correlation coefficient.

[0063] Example 3

[0064] A method for improving fish muscle quality by regulating the intestinal microenvironment through a neuroendocrine system comprises the following steps:

[0065] 1) Before use, sterilize the holding pond: sterilize the holding pond with 1 / 10000 volume of methylene blue;

[0066] After sterilizing the temporary holding pond, inject aerated water into the temporary holding pond (the temporary holding pond is 8m in diameter, 1.5m in height, and the stocking density is about 30kg / m 3 The water depth is controlled at 1m. Before the live fish are put into the temporary holding pond, the water in the pond is aerated for one day, and the temporary holding pond is oxygenated with an aerator to ensure that the dissolved oxygen in the water is 7.0-8.0mg / L, the water temperature is 16-24℃, and the pH is 7.8-8.0;

[0067] 2) adding a mixture of 100 mg / L of Lactobacillus MN047 and 50 mg / L of lotus root node extract to water, and stirring to make it evenly dispersed;

[0068] 3) Randomly select 50 healthy, well-shaped, and undamaged largemouth bass weighing 400±20g and place them in a temporary holding pond. The stocking density is adjusted to 30kg / m 3 , the fish were fasted during temporary rearing; recorded as experimental group 2;

[0069] 4) The temporary rearing time is adjusted to 21 days, and the water is changed once a day during the temporary rearing period, and the amount of water changed is 2 / 3 of the original water volume; then the mixed inputs of step 2) are added again, and the concentration of the mixed inputs is adjusted to be consistent with that of step 2); fasting treatment is performed during the entire temporary rearing period;

[0070] 5) After the temporary rearing is completed, the fresh largemouth bass is placed in a bucket containing 50 mg / L of anesthetic. After the fresh freshwater fish is completely anesthetized, professionals remove its brain, midgut, muscle and other tissues, quickly package them, and then quickly freeze them in liquid nitrogen, and then place them in a -80°C refrigerator for testing;

[0071] 6) Using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to separate and determine neurotransmitters in brain tissue, using 16s bacterial diversity analysis to identify the microbial flora in the midgut, using a YYW-2 strain-controlled unconfined pressure instrument to determine the pressurized water loss rate of fish meat, and using a C-LM3B tenderizer to determine the shear force of fish meat;

[0072] 7) Analyze the data obtained in step 6) to determine the regulatory effect of the mixed input on the neurotransmitters, intestinal microorganisms and muscle quality of fresh freshwater fish; use correlation analysis to determine the correlation between neurotransmitters, intestinal microorganisms and muscle quality based on the correlation coefficient.

[0073] In this embodiment, in the preliminary prediction of the muscle quality of fresh fish according to the breathing frequency, the user only needs to operate according to the steps 1)-4) without repeating the subsequent steps.

[0074] Referring to Table 1, the present invention can effectively reduce the secretion of excitatory neurotransmitters histamine and kynurenine by adding 50 mg / L of Lactobacillus MN047 and 20 mg / L of lotus root node extract or 100 mg / L of Lactobacillus MN047 and 50 mg / L of lotus root node extract, thereby reducing the stress response to the nervous, endocrine and immune systems of fish caused thereby.

[0075] Reference Figure 1 The present invention can effectively maintain intestinal microbial homeostasis by adding 50 mg / L of Lactobacillus MN047 and 20 mg / L of lotus root node extract or 100 mg / L of Lactobacillus MN047 and 50 mg / L of lotus root node extract, thereby reducing the number of intestinal pathogenic bacteria in largemouth seabass and increasing the abundance of beneficial intestinal bacteria.

[0076] Referring to Table 2, the present invention can effectively improve muscle quality by adding 50 mg / L of Lactobacillus MN047 and 20 mg / L of lotus root node extract or 100 mg / L of Lactobacillus MN047 and 50 mg / L of lotus root node extract.

[0077] Reference Figure 2a , Figure 2b The present invention can reduce neurotransmitter secretion, maintain intestinal flora homeostasis, and alleviate muscle quality deterioration by adding 50 mg / L of Lactobacillus MN047 and 20 mg / L of lotus root node extract or 100 mg / L of Lactobacillus MN047 and 50 mg / L of lotus root node extract.

[0078] Table 1 is a statistical table of neurotransmitters with significantly different expression levels in the fish brain of the present invention.

[0079]

[0080] Table 2 is the fish muscle quality evaluation index of the present invention

[0081]

[0082] The upper and lower limits of the amount of added Lactobacillus bread and lotus root node extract cited in the present invention can all achieve the present invention. The yellow catfish, rainbow trout, mandarin fish, etc. can all achieve the present invention. The upper and lower limits of dissolved oxygen, water temperature, and pH value can all achieve the present invention. The embodiments are not listed one by one here.

Claims

1. A method for improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system, characterized in that The steps include: 1) After sterilizing the temporary holding pond, inject aerated water to 2 / 3 of the height of the temporary holding pond, use an aerator to adjust the dissolved oxygen in the water to 5.0-8.0 mg / L, the water temperature to 16-24°C, the pH to 7.2-8.0, and the ammonia nitrogen content to less than 0.5 mg / L; 2) adding a mixture of 50-100 mg / L of Lactobacillus MN047 and 20-50 mg / L of lotus root node extract to water, and stirring to make it evenly dispersed; 3) According to the breeding density of 20-30kg / m 3 Put fresh water fish into the temporary holding pond and fast the fish during the temporary holding period; 4) The temporary culture period is 20-22 days, during which time the water needs to be replaced by 2 / 3 of the water volume every day, and then the mixed inputs are re-added, and the concentration of the mixed inputs is adjusted to be consistent with step 2); 5) After the temporary rearing is completed, the fresh-water fish is placed in a bucket containing 50 mg / L of anesthetic. After the fresh-water fish is completely anesthetized, the brain, midgut and muscle tissue are removed, and the fish are quickly packaged and quickly frozen in liquid nitrogen, and then placed in a -80°C refrigerator for testing; 6) Using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to separate and determine neurotransmitters in brain tissue, using 16s bacterial diversity analysis to identify the microbial flora in the midgut, using a YYW-2 strain-controlled unconfined pressure instrument to determine the pressurized water loss rate of fish meat, and using a C-LM3B tenderizer to determine the shear force of fish meat; 7) Analyze the data obtained in step 6) to determine the regulatory effect of the mixed input on the neurotransmitters, intestinal microorganisms and muscle quality of fresh freshwater fish; use correlation analysis to determine the correlation between neurotransmitters, intestinal microorganisms and muscle quality based on the correlation coefficient.

2. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: The temporary holding pond in step 1) is a circular canvas pond with a diameter of 8m, a height of 1.5m, and a water level of 1m; the temporary holding pond is sterilized in step 1) by using 1 / 10000 volume of methylene blue to sterilize the temporary holding pond.

3. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: In step 1), the dissolved oxygen in the water is ensured to be 7.0-8.0 mg / L, the water temperature is 16-24° C., and the pH is 7.8-8.

0.

4. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: Step 2) The bread lactobacillus MN047 is a strain of bread lactobacillus MN047 that can produce multiple broad-spectrum bacteriocins, which is screened from homemade mare's milk in Xinjiang, my country. The antibacterial metabolites of this strain can inhibit foodborne pathogens and regulate intestinal flora.

5. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: Step 2) The lotus root node extract is a mixture containing a certain amount of plant polyphenols extracted from lotus root nodes, and the extraction method is as follows: after the lotus root nodes are cut into pieces and ground into a paste, 0.15 mg / mL cellulase (50000 U / g) + pectinase (30000 U / g) is used, and the mass ratio of cellulase to pectinase is 1:

1. After extraction for 90 minutes at a temperature of 62°C and pH 4, the extract is centrifuged at 4000×g for 20 minutes, and the supernatant is collected as a crude extract; subsequently, a preliminary alcohol precipitation is performed with 60% ethanol and then purified with AB-8 macroporous resin. After freeze-drying, the total phenol concentration is measured to be 68.73 mg / 100 mg, thereby obtaining a lotus root node extract.

6. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: The fresh freshwater fish in step 3) are special freshwater fish such as yellow catfish, rainbow trout, mandarin fish, largemouth bass, etc., which are healthy, in good shape, and without damage on the body surface.

7. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: Step 3) The fresh freshwater fish are all edible adult fish, with the mass of yellow catfish being 300±10g, the mass of rainbow trout being 2000±115g, the mass of mandarin fish being 500±50g, and the mass of largemouth bass being 400±20g.

8. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: Step 5) The molecular formula of the anesthetic is ethyl m-aminobenzoate methanesulfonate (MS-222), molecular formula: C 10 H 15 NO5S.

9. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: Step 6) The specific method for determining the pressure water loss rate is as follows: cut a 4cm×4cm gauze and weigh it (M0), weigh 2±0.02g of fresh freshwater fish sample and wrap it with gauze and weigh it (M1), place 8 filter papers of the same size on the top and bottom of the sample, place the fish sample wrapped in the middle of the YYW-2 type pressure plate, and adjust the pressure instrument to 145pa and keep it on the sample for 5min; after the test, weigh the gauze and sample after pressurization and record it as (M2); the pressure water loss rate of the fish fillet is calculated using the following formula: Where: X——pressure water loss rate of the sample, % M0——gauze mass, g; M1——Total mass of gauze and sample before pressurization, g; M2——The total mass of gauze and sample after pressurization, g.

10. The method of improving fish muscle quality by regulating the intestinal microenvironment through the neuroendocrine system according to claim 1, characterized in that: Step 6) The specific method for measuring the shear force is: cut the back muscles of the same part into long strips of similar shape and specification, reset the instrument before measuring, and move the blade downward at a constant speed until the muscle is completely cut.

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