Low-stress bloodletting processing method for channel catfish

Abstract

The invention discloses a low-stress bloodletting processing method for channel catfish, which comprises the following steps: an acid-base regulation and control step: putting channel catfish into water containing sodium citrate to carry out in-vivo acid-base regulation and control so as to improve the in-vivo alkali reserve of the channel catfish; a combined slight anesthesia step: performing slight anesthesia on the channel catfish under the combined action of low temperature and a chemical anesthetic, so that the channel catfish is in a state that gill cover opening and closing are weak, the frequency is slow, and the rollover balance of a fish body is lost; a fish body puncturing step: destroying blood circulation of the channel catfish body through a manual or mechanical method, and making a bleeding wound on the channel catfish body; a metabolism bloodletting step: putting the fish body into a bloodletting tank which is aerated and oxygenated in advance until the fish body is saturated with dissolved oxygen for bloodletting, and keeping a certain dissolved oxygen concentration; and an ultrasonic blood purification step: enabling the fish body to enter a bloodletting groove with an ultrasonic device for bloodletting so as to accelerate the discharge of residual blood in the body.

Description

Technical Field

[0001] The invention relates to the technical field of fish processing, in particular to a bleeding processing method for channel catfish. Background Art

[0002] Channel catfish is one of the main freshwater economic fish in my country. It is deeply loved by consumers because of its lack of intramuscular spines and tender and plump meat. In recent years, the domestic catfish market has developed from the single sale of fresh fish to diversified catfish processed products. The demand for frozen catfish, catfish fillets, catfish chunks, seasoned catfish and other products has been increasing, indicating that the production and processing of channel catfish has broad industry prospects.

[0003] Compared with other freshwater fish, channel catfish has a stronger earthy smell, which restricts its processing and utilization to a certain extent. The production of fishy smell is mainly related to protein degradation, lipid oxidation, enzymatic reaction, etc., and the heme in fish blood accelerates the production of fishy substances. At the same time, the bitter amino acids in the blood are also one of the reasons for the earthy smell of fish meat. Therefore, by removing the blood in the channel catfish, it helps to reduce the source of fishy substances, thereby improving the quality of fish meat. The main methods of bleeding and slaughtering fish are cutting the gills, puncturing the heart, breaking the tail and breaking the spine. When the tissue is damaged, the blood flows on the body surface and coagulates quickly, which is related to the presence of a large amount of lectins and thrombin in the fish mucus. Channel catfish is a phosphorus-free fish with a lot of mucus on its body surface and gills. During the process of catching and transporting, it is stressed by factors such as crowding, transportation, and lack of oxygen. The fish skin will secrete mucus to defend against stress. Before bleeding, the amount of mucus secreted on the fish body surface increases. Although the current dynamic flow bleeding method can clean and remove part of the mucus, it is not very effective for channel catfish with a large amount of mucus secretion. A lot of mucus remains on the fish body surface, which ultimately affects the effect and efficiency of bleeding.

[0004] Studies have shown that the state of the fish itself during bleeding will affect the quality of the fish meat. Bleeding fish that are not unconscious will produce stress reactions such as pressure, which will change the chemical composition of muscle tissue and cause insufficient bleeding and blood coagulation. Killing or stunning the fish before bleeding can make the fish lose their ability to move and struggle, reducing the occurrence of stress reactions. The common method of stunning or killing by knocking on the head is affected by human subjective factors. The force of the knock is uncontrollable, and excessive force can cause damage to the fish body. Carbon dioxide anesthesia has the problem of long recovery time and limited anesthesia objects. Although electric shock anesthesia has a short action time and fast onset, the electric anesthesia parameters of aquatic products, such as voltage and current duration, are difficult to master and difficult to use. It is not suitable for large-scale industrial production. At the same time, there is no mature electric anesthesia equipment for aquatic product processing on the market. Summary of the invention

[0005] The purpose of the invention is to provide a low-stress bleeding processing method for channel catfish to overcome the defects in the prior art.

[0006] The object of the present invention is achieved by: a low-stress bleeding processing method for channel catfish, comprising the following steps:

[0007] an acid-base regulation step, placing the channel catfish in water containing sodium citrate to regulate the acid-base in the body, thereby increasing the alkali reserve in the fish body;

[0008] Combined with the mild anesthesia step, the channel catfish is mildly anesthetized through the combined effects of low temperature and chemical anesthetics, so that the fish exhibits a state in which the gill cover opens and closes weakly and slowly, and the fish body rolls over and loses balance;

[0009] The fish puncture step involves disrupting the blood circulation of the channel catfish by artificial or mechanical means, thereby creating a bleeding wound on the fish body;

[0010] Metabolic bleeding step: the fish body is placed in a bleeding tank that has been aerated and oxygenated to saturated dissolved oxygen in advance for bleeding, and a certain dissolved oxygen concentration is maintained;

[0011] In the ultrasonic blood purification step, the fish body enters a bleeding tank equipped with an ultrasonic device for bleeding, which accelerates the discharge of residual blood in the body.

[0012] Furthermore, in the acid-base control step, a water circulation system and an oxygenation system are used to keep the water clean and oxygen-sufficient.

[0013] Furthermore, in the combined mild anesthesia step, a certain mass concentration of chemical anesthetics is added to the low-temperature water body, and the spotted catfish is mildly anesthetized through the combined action of low temperature and chemical anesthetics. When the fish body shows weak opening and closing of the gill cover and slow frequency, slow swimming, slight loss of balance and flipping of the fish body, the fish is taken out of the anesthesia pool for the next processing.

[0014] Furthermore, in the combined mild anesthesia step, a judgment link of mild anesthesia of channel catfish is set. In this link, the state of the fish body of the channel catfish after anesthesia is collected by machine vision, and the end time of mild anesthesia is determined according to the color change of the image.

[0015] Furthermore, in the combined light anesthesia step, the fish swam normally before anesthesia, and the color of the fish image taken by the camera from top to bottom was mainly gray-brown, which is the dorsal fin and head of the spotted catfish. After light anesthesia, the fish lost balance and began to roll over, exposing its milky white belly. The light-colored area in the image increased and the dark-colored area decreased. The area change of the light-colored area of ​​the fish body after light anesthesia was calculated through image processing, thereby determining the end time of light anesthesia.

[0016] Furthermore, in the metabolic bleeding step, the bleeding trough is equipped with an oxygenation system. When the fish has not completely stopped breathing, the breathing rate of the fish is increased by increasing the dissolved oxygen content in the water environment, thereby metabolizing and excreting the anesthetic in the body and accelerating the outflow of blood from the fish; the bleeding trough is aerated and oxygenated to saturated dissolved oxygen before the fish is put in, and the dissolved oxygen content of the water is maintained at not less than 8 mg / L during this stage; the bleeding trough is equipped with a circulating water system, so that the water in the trough is in a flowing state to promote blood outflow, while reducing the impact of long-term immersion of fish in high-concentration blood water on quality, and the water circulation volume is not less than 5 cubic meters / hour.

[0017] Furthermore, in the ultrasonic blood purification step, when the ultrasonic device is in operation, ultrasonic waves are generated to destroy the network structure of mucus on the body surface of the channel catfish.

[0018] The beneficial effects of the present invention are:

[0019] The invention reduces the stress response of the fish body by increasing the alkali reserve in the channel catfish body before bleeding and combining low temperature-chemical anesthetic with mild anesthesia; the acid-base regulation of the fish body in water containing sodium citrate can increase the alkali reserve in the fish body and slow down the stress response of the fish body when slaughtering; at the same time, sodium citrate can react with Ca2+, which activates the coagulation factor, to reduce the stress response of the fish body when slaughtering. 2+ The formation of complexes hinders the formation of coagulation factors and is more conducive to the outflow of blood; the channel catfish is lightly anesthetized before bleeding by the combined action of low temperature and chemical anesthetics, and the coma degree, body state, recovery time, etc. of the fish are controlled by creating a low temperature environment and adjusting the concentration of anesthetics, thereby reducing the pain and struggle of the fish during stabbing and bleeding, improving animal welfare and the convenience of bleeding operations; the fish is bled in stages, the first stage is metabolic bleeding, when the fish has not completely stopped breathing, the breathing rate of the fish is accelerated by increasing the dissolved oxygen in the environment, the anesthetic in the body is metabolized and discharged, and the blood outflow of the fish is accelerated; the second stage is the ultrasonic blood purification stage, the grid structure of the mucus on the surface of the channel catfish is destroyed by ultrasound, so that the blood outflow is not hindered, and on the other hand, the flow and diffusion of the residual blood in the fish can be accelerated to ensure sufficient bleeding and thus improve the quality of the channel catfish meat. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the main steps of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, a low-stress bleeding processing method for channel catfish is proposed, which mainly includes the following steps:

[0023] an acid-base regulation step, placing the channel catfish in water containing sodium citrate to regulate the acid-base in the body, thereby increasing the alkali reserve in the fish body;

[0024] Combined with the mild anesthesia step, the channel catfish is mildly anesthetized through the combined effects of low temperature and chemical anesthetics, so that the fish exhibits a state in which the gill cover opens and closes weakly and slowly, and the fish body rolls over and loses balance;

[0025] The fish puncture step involves disrupting the blood circulation of the channel catfish by artificial or mechanical means, thereby creating a bleeding wound on the fish body;

[0026] Metabolic bleeding step: the fish body is placed in a bleeding tank that has been aerated and oxygenated to saturated dissolved oxygen in advance for bleeding, and a certain dissolved oxygen concentration is maintained;

[0027] In the ultrasonic blood purification step, the fish body enters a bleeding tank equipped with an ultrasonic device for bleeding, which accelerates the discharge of residual blood in the body.

[0028] Among them, the above steps interact with each other and are indispensable, ultimately achieving the purpose of clean bleeding of live fish under a low-stress state.

[0029] The specific method is as follows.

[0030] In the acid-base regulation step, channel catfish are placed in a water tank containing a certain concentration of sodium citrate. Sodium citrate is alkaline and can relieve the acid-base imbalance of fish caused by transportation stress such as crowding, vibration, and water quality, increase the alkali reserve in the fish, and reduce the stress response caused by slaughtering the fish. The water tank is equipped with a water circulation system and an oxygenation system to ensure clean water and sufficient oxygen. The environmental parameters are: density 50-100kg / m 3 , the water temperature is controlled at 20-25°C, the amount of sodium citrate added is 0.2%-0.5%, the time is 60-120min, and the dissolved oxygen concentration is not less than 8mg / L.

[0031] In the combined mild anesthesia, a certain mass concentration of MS-222 anesthetic solution is added to the low-temperature water, and the channel catfish is mildly anesthetized through the combined action of low temperature and chemical anesthetics. When the fish body shows that the gill cover is weak and the frequency is slow, the fish body is slowly swimming, and the balance is slightly lost and the fish body flips, the fish is taken out of the anesthesia tank for the next step of processing. The parameters of mild anesthesia are: MS-222 anesthetic solution concentration 40 ～ 100mg / L, anesthesia temperature 5 ～ 10℃, anesthesia fish water ratio 1:8 ～ 1:12, time 5～ 10min.

[0032] The steps for determining mild anesthesia of spotted catfish are as follows: the state of the fish after anesthesia is collected through machine vision, and the end time of mild anesthesia is determined based on the color change of the image; before anesthesia, the fish swims normally, and the color of the fish image taken from top to bottom by the camera is mainly gray-brown in color of the dorsal fin and head of the spotted catfish. After mild anesthesia, the fish loses balance and begins to flip over, exposing its milky white belly. The light-colored area in the image increases and the dark-colored area decreases. The area change of the light-colored area of ​​the fish after mild anesthesia is calculated through image processing to determine the end time of mild anesthesia.

[0033] A machine vision camera was installed above the anesthesia pool. The captured channel catfish image was converted into a grayscale image and subjected to noise reduction. The light-colored feature area of ​​the fish body was extracted through edge detection. The area of ​​the area was calculated based on the number of pixels in the feature area. The calculation formula is:

[0034] S=m×f 2 (1)

[0035] Where: S is the area of ​​the light-colored area; m is the number of pixels in the light-colored area; f is the pixel scale transformation parameter;

[0036] A large number of images were taken to obtain the light-colored area of ​​the channel catfish in a completely flat position, and the average value S was calculated. n , assuming that the light-colored area of ​​the fish posture image captured during anesthesia is S', the anesthesia determination formula is:

[0037]

[0038] In the fish puncture step, the blood circulation of the channel catfish is disrupted by artificial or mechanical methods to create a bleeding wound on the fish body.

[0039] In the metabolic bleeding step, the bleeding tank is equipped with an oxygenation system. When the fish has not completely stopped breathing, the breathing rate of the fish is increased by increasing the dissolved oxygen in the environment, the anesthetic in the body is metabolized and discharged, and the blood outflow of the fish is accelerated; before the fish is put in, the bleeding tank is aerated and oxygenated to saturated dissolved oxygen, and the dissolved oxygen in the water is maintained at not less than 8mg / L during this stage; the bleeding tank is equipped with a circulating water system to make the water in the tank flow to promote blood outflow, while reducing the impact of long-term immersion of fish in high-concentration blood water on quality. The water circulation volume is not less than 5 cubic meters per hour. The bleeding environment parameters are raw fish density 50-100kg / m 3 , the water temperature is controlled at 20-25℃, and the bloodletting time is controlled at 10-20min.

[0040] In the ultrasonic blood purification step, an ultrasonic device is arranged in the bleeding tank. When the ultrasonic device is in operation, ultrasonic waves are generated, which destroy the grid structure of the mucus on the surface of the spotted catfish through the action of ultrasonic waves, so that the blood can flow out unhindered. On the other hand, the flow and diffusion of the fish blood are accelerated, so as to ensure sufficient bleeding and improve the quality of the fish meat. The parameters of the bleeding environment are as follows: the raw fish density is 50-100kg / m 3 , the water temperature is controlled at 10-15℃, the ultrasonic frequency is 20-100kHz, and the bloodletting time is controlled at 10-15min.

[0041] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention; in the present invention, it should also be noted that the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integrally formed connection, a mechanical connection, or an indirect connection through an intermediate connecting component, and the specific meaning of the terms in this utility model can be understood according to the specific circumstances.

[0042] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0043] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A low-stress bleeding method for channel catfish, characterized in that: The steps include: an acid-base regulation step, placing the channel catfish in water containing sodium citrate to regulate the acid-base in the body, thereby increasing the alkali reserve in the fish body; Combined with the mild anesthesia step, the channel catfish is mildly anesthetized through the combined effects of low temperature and chemical anesthetics, so that the fish exhibits a state in which the gill cover opens and closes weakly and slowly, and the fish body rolls over and loses balance; The fish puncture step involves disrupting the blood circulation of the channel catfish by artificial or mechanical means, thereby creating a bleeding wound on the fish body; Metabolic bleeding step: the fish body is placed in a bleeding tank that has been aerated and oxygenated to saturated dissolved oxygen in advance for bleeding, and a certain dissolved oxygen concentration is maintained; In the ultrasonic blood purification step, the fish body enters a bleeding tank equipped with an ultrasonic device for bleeding, which accelerates the discharge of residual blood in the body.

2. The low-stress bleeding processing method of channel catfish according to claim 1, characterized in that: In the acid-base control step, the water circulation system and oxygenation system are used to keep the water clean and oxygen-sufficient.

3. The low-stress bleeding processing method of channel catfish according to claim 1, characterized in that: In the combined mild anesthesia step, a certain mass concentration of chemical anesthetics is added to the low-temperature water body, and the spotted catfish is mildly anesthetized through the combined action of low temperature and chemical anesthetics. When the fish body shows weak opening and closing of the gill cover and slow frequency, slow swimming, slight loss of balance and flipping of the fish body, the fish is taken out of the anesthesia pool for the next processing.

4. The low-stress bleeding processing method of channel catfish according to claim 3, characterized in that: In the combined mild anesthesia step, a judgment link of mild anesthesia of channel catfish is set. In this link, the state of the fish body after anesthesia of channel catfish is collected by machine vision, and the end time of mild anesthesia is determined according to the color change of the image.

5. The low-stress bleeding processing method of channel catfish according to claim 4, characterized in that: In the combined light anesthesia step, the fish swam normally before anesthesia, and the color of the fish image taken by the camera from top to bottom was mainly gray-brown, the dorsal fin and head of the spotted catfish. After light anesthesia, the fish lost balance and began to flip sideways, exposing its milky white belly. The light-colored area in the image increased and the dark-colored area decreased. The area change of the light-colored area of ​​the fish body after light anesthesia was calculated through image processing, thereby determining the end time of light anesthesia.

6. The low-stress bleeding processing method of channel catfish according to claim 5, characterized in that: The captured channel catfish image was converted into a grayscale image and subjected to noise reduction. The light-colored characteristic area of ​​the fish body was extracted through edge detection. The area of ​​the area was calculated based on the number of pixels in the characteristic area. The calculation formula is: S=m=f 2 (1) Where: S is the area of ​​the light-colored area; m is the number of pixels in the light-colored area; f is the pixel scale transformation parameter; The light-colored area of ​​the channel catfish in a completely flat position was obtained by taking a large number of images, and the average value Sn was calculated. The light-colored area of ​​the fish posture image taken during anesthesia was set as S', and the anesthesia determination formula was:

7. The low-stress bleeding processing method of channel catfish according to claim 1, characterized in that: In the metabolic bleeding step, the bleeding trough is equipped with an oxygenation system. When the fish has not completely stopped breathing, the breathing rate of the fish is increased by increasing the dissolved oxygen content in the water environment, so that the anesthetic in the body is metabolized and discharged, and the outflow of blood from the fish is accelerated; before the fish is put in, the bleeding trough is aerated and oxygenated to saturated dissolved oxygen, and the dissolved oxygen content of the water is maintained at not less than 8mg / L during this stage; the bleeding trough is equipped with a circulating water system, so that the water in the trough is in a flowing state to promote blood outflow, while reducing the impact of long-term immersion of fish meat in high-concentration blood water on quality, and the water circulation volume is not less than 5 cubic meters / hour.

8. The low-stress bleeding processing method of channel catfish according to claim 1, characterized in that: In the ultrasonic blood purification step, when the ultrasonic device is in operation, ultrasonic waves are generated to destroy the network structure of mucus on the body surface of the channel catfish.

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