A low-stress bleeding processing method for channel catfish

Abstract

The invention discloses a low-stress bleeding processing method for channel catfish. The method comprises the following steps: an acid-base control step, in which the channel catfish is placed in water containing sodium citrate to control the acid-base in the body, thereby increasing the alkali reserve in the body of the fish; a combined light anesthesia step, in which the channel catfish is lightly anesthetized through the combined action of low temperature and a chemical anesthetic, so that the fish exhibits a state in which the gill cover of the fish opens and closes weakly and slowly, and the fish body rolls over and loses balance; a fish body puncture step, in which the blood circulation of the channel catfish is destroyed by a manual or mechanical method, thereby creating a bleeding wound on the fish body; a metabolic bleeding step, in which the fish body is placed in a bleeding tank that has been aerated and oxygenated in advance to saturated dissolved oxygen, for bleeding, while maintaining a certain dissolved oxygen concentration; and an ultrasonic blood purification step, in which the fish body is placed in a bleeding tank equipped with an ultrasonic device for bleeding, thereby accelerating 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] The channel catfish is one of my country's major freshwater commercial fish species, beloved by consumers for its lack of intramuscular spines and tender, plump flesh. In recent years, the domestic catfish market has evolved from solely focusing on fresh fish sales to a diversified offering of processed catfish products. Demand for frozen catfish, catfish fillets, catfish chunks, and seasoned catfish is increasing, demonstrating the broad prospects for the production and processing of channel catfish.

[0003] Compared to other freshwater fish, channel catfish have a stronger earthy odor, which to some extent restricts their processing and utilization. The production of this odor is primarily related to protein degradation, lipid oxidation, and enzymatic reactions. Hemoglobin in fish blood accelerates the production of odorous substances. Bitter amino acids in blood also contribute to the earthy odor of fish meat. Therefore, removing the blood from channel catfish can help reduce the source of odorous substances and improve the quality of the fish meat. Bleeding fish is typically done by gill cutting, cardiac puncture, tail docking, and spine breaking. When tissue is damaged, blood flows to the surface of the body and quickly coagulates, which is related to the presence of large amounts of lectins and thrombin in fish mucus. The spotted forktail catfish is a phosphorus-free fish with a lot of mucus on its body surface and gills. During the capture and transportation process, 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 some of the mucus, it is not very effective for spotted forktail 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 during bleeding can affect its quality. Bleeding fish that are not unconscious can cause stress reactions, such as pressure, which can alter the chemical composition of muscle tissue and result in inadequate bleeding and blood coagulation. Killing or stunning the fish before bleeding can render them unable to move and struggle, reducing the stress response. The common method of stunning or killing by striking the head is subject to subjective human factors, as the force of the blow is uncontrollable and excessive force can cause damage to the fish. Carbon dioxide anesthesia has a long recovery time and is limited in the number of subjects it can anesthetize. While electric shock anesthesia has a short duration and rapid onset, the parameters for electric anesthesia for aquatic products, such as voltage and current duration, are difficult to control and difficult to use, making it unsuitable for large-scale industrial production. Furthermore, there is no mature electric anesthesia equipment available on the market for aquatic product processing. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-stress bleeding processing method for channel catfish, so as 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 and increase the alkaline reserve in the fish;

[0008] Combined with a mild anesthesia step, the channel catfish is mildly anesthetized through the combined effects of hypothermia and chemical anesthetics, causing the fish to exhibit weak and slow gill cover opening and closing, and to flip over and lose balance.

[0009] The fish puncture step involves disrupting the channel catfish's blood circulation through manual or mechanical means, creating a bleeding wound on the fish's 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 oxygenated.

[0013] Furthermore, in the combined mild anesthesia step, a certain mass concentration of chemical anesthetic is added to the low-temperature water body, and the spotted catfish is mildly anesthetized through the combined action of low temperature and chemical anesthetic. 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 tank for the next processing.

[0014] Furthermore, in the combined light anesthesia step, a light anesthesia judgment link for channel catfish is set. In this link, the body state of the channel catfish after anesthesia is collected by machine vision, and the end time of light 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, 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 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 tank is equipped with an oxygenation system. When the fish has not completely stopped breathing, the fish's breathing rate 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 tank 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 tank is equipped with a circulating water system to keep the water in the tank flowing 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 present invention reduces the stress response of the fish by increasing the alkali reserve in the body of channel catfish before bleeding and combining low temperature and chemical anesthetics 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 slaughtered. At the same time, sodium citrate can react with Ca2+, which activates coagulation factors, to reduce the stress response of the fish body. 2+ The method forms a complex, hindering the formation of coagulation factors and facilitating blood flow. A combination of low temperature and chemical anesthetics is used to lightly anesthetize the channel catfish before bleeding. By creating a low temperature and adjusting the concentration of the anesthetic to control the fish's coma, body condition, and recovery time, the fish's pain and struggle during stabbing and bleeding are reduced, improving animal welfare and the convenience of the bleeding operation. Bleeding is performed in stages. The first stage is metabolic bleeding. Before the fish completely stops breathing, the fish's respiratory rate is accelerated by increasing the dissolved oxygen in the environment, metabolizing and expelling the anesthetic in the body while accelerating blood flow. The second stage is ultrasonic blood purification. Ultrasound is used to destroy the network structure of the mucus on the channel catfish's body surface, allowing unimpeded blood flow. This also accelerates the flow and diffusion of residual blood in the fish, ensuring sufficient bleeding and thus improving 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 clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0022] like Figure 1 As shown in FIG, 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 and increase the alkaline reserve in the fish;

[0024] Combined with a mild anesthesia step, the channel catfish is mildly anesthetized through the combined effects of hypothermia and chemical anesthetics, causing the fish to exhibit weak and slow gill cover opening and closing, and to flip over and lose balance.

[0025] The fish puncture step involves disrupting the channel catfish's blood circulation through manual or mechanical means, creating a bleeding wound on the fish's 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] During the acid-base control step, channel catfish are placed in a tank containing a certain concentration of sodium citrate. Sodium citrate is alkaline and can alleviate the acid-base imbalance caused by transportation stresses such as crowding, vibration, and water quality. This can increase the body's alkaline reserves and reduce the stress response caused by slaughter. The tank is equipped with a water circulation system and an oxygenation system to ensure clean water and sufficient oxygen. Environmental parameters are: density 50-100 kg / m 3 , the water temperature is controlled at 20-25℃, 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 combined mild anesthesia, a certain mass concentration of MS-222 anesthetic solution is added to the low-temperature water. Through the combined action of low temperature and chemical anesthetics, the channel catfish is mildly anesthetized. When the fish shows weak and slow gill cover opening and closing, slow swimming, slight loss of balance and flipping of the fish body, the fish is removed from the anesthesia tank for the next 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～ 10 minutes.

[0032] The steps for determining mild anesthesia in spotted catfish are as follows: the fish's body state after anesthesia is captured 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, showing the dorsal fin and head of the spotted catfish. After mild anesthesia, the fish loses balance and begins to flip sideways, exposing its milky white belly. The light-colored area in the image increases, while the dark-colored area decreases. The area change of the light-colored area of ​​the fish body after mild anesthesia is calculated through image processing, thereby determining the end time of mild anesthesia.

[0033] A machine vision camera was installed above the anesthesia tank. The captured images of channel catfish were converted into grayscale images and subjected to noise reduction. The light-colored feature areas of the fish body were extracted through edge detection. The area of ​​the feature areas was calculated based on the number of pixels in the feature areas. 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] By taking a large number of images, the area of ​​the light-colored area of ​​the channel catfish body in a completely flat position was obtained, and the average value S was calculated. n , assuming that the area of ​​the light-colored area of ​​the fish posture image captured during anesthesia is S', the anesthesia determination formula is:

[0037]

[0038] During 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] During the metabolic bleeding step, the bleeding tank is equipped with an oxygenation system. When the fish has not completely stopped breathing, the fish's breathing rate is increased by increasing the dissolved oxygen in the environment, which metabolizes and excretes the anesthetic in the body and accelerates the outflow of blood from the fish. 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 keep the water in the tank flowing to promote blood outflow and reduce the impact of long-term immersion of fish in high-concentration blood water on its quality. The water circulation volume is not less than 5 cubic meters per hour. The bleeding environment parameters are raw fish density of 50-100kg / m 3 , the water temperature is controlled at 20-25℃, and the bloodletting time is controlled at 10-20 minutes.

[0040] During the ultrasonic blood purification step, an ultrasonic device is installed in the bleeding tank. When the ultrasonic device is in operation, it generates ultrasonic waves, which destroy the network structure of the mucus on the surface of the channel catfish through the ultrasonic action, allowing blood to flow out unimpeded. On the other hand, it accelerates the flow and diffusion of blood in the fish body, ensuring sufficient bleeding and thus improving the quality of the fish meat. The parameters of the bleeding environment are: 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", etc. indicate orientations or positional relationships based on the orientations 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 orientation, be constructed and operated in a specific orientation, 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 will be apparent 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 invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be embraced herein, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0043] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method 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 can also be appropriately combined to form other implementation methods 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 and increase the alkaline reserve in the fish; Combined with a mild anesthesia step, the channel catfish is mildly anesthetized through the combined effects of hypothermia and chemical anesthetics, causing the fish to exhibit weak and slow gill cover opening and closing, and to flip over and lose balance. The fish puncture step involves disrupting the channel catfish's blood circulation through manual or mechanical means, creating a bleeding wound on the fish's 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 method for channel catfish according to claim 1, wherein: During the acid-base control step, the water circulation system and oxygenation system are used to keep the water clean and oxygenated.

3. The low-stress bleeding method for channel catfish according to claim 1, wherein: 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 tank for the next processing.

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

5. The low-stress bleeding method for 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 method for 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 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: 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 area of ​​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 area of ​​the light-colored area of ​​the fish posture image taken during anesthesia was set as S'. The anesthesia determination formula is:

7. The low-stress bleeding method for channel catfish according to claim 1, characterized in that: During the metabolic bleeding step, the bleeding tank is equipped with an oxygenation system. When the fish has not completely stopped breathing, the fish's breathing rate 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; before the fish is put in, the bleeding tank 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 tank is equipped with a circulating water system to keep the water in the tank flowing 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 / hour.

8. The low-stress bleeding method for 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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