Processing method for scaling and opening back of fish

Abstract

The invention relates to the technical field of fish processing, provides a fish scaling and back-opening processing method, and overcomes the defects that a fish scaling and back-opening processing method in the prior art is low in production efficiency and causes mechanical damage to a fish body. Comprising the following treatment steps: (1) thoroughly flushing fish; (2) feeding the fish into a scaling solution for soaking treatment: preparing the scaling solution containing a compound enzyme, feeding the fish into the scaling solution for soaking treatment for 20-30 minutes, controlling the temperature of the scaling solution to be 35-39 DEG C, controlling the pH value of the scaling solution to be 6.5-8.0, and controlling the concentration of the compound enzyme to be 1-3 mg / ml, (3) water washing: spraying and washing the fish body soaked in the step (2) with high-pressure water to remove fish scales; and (4) back opening treatment.

Description

Technical Field

[0001] The invention relates to the technical field of fish processing, in particular to a fish descaling and back-opening processing method. Background Art

[0002] At present, most fish descaling operations are done manually, which mainly involves descaling fish one by one with the help of knives or fish scalers. This method has low work efficiency, high labor intensity, requires a large amount of manpower, and has high production and processing costs, and cannot adapt to the development needs of the food processing industry.

[0003] In order to improve production efficiency, people use descaling devices for assembly line production. For example, Chinese Patent No. 202110388391.9 discloses an intelligent fish descaling device and method based on a horizontal multi-stage drum shaft propeller, the device includes an equipment frame, a raw fish feeding hopper, a descaling multi-stage drum assembly, a descaling multi-stage drum assembly driving device, a central tube shaft system, a central tube shaft system driving device, a spray water pipeline system, and a descaling fish discharging device; the descaling multi-stage drum assembly is composed of at least 3 levels of descaling drum monomers spliced ​​together concentrically and coaxially, and the descaling multi-stage drum assembly includes a first-stage descaling drum, a second-stage descaling drum, and a third-stage descaling drum. The inner wall of the first-stage descaling drum is radially provided with a plurality of long strip blades, and the third-stage descaling drum is provided with a plurality of long strip blades. A diamond mesh of a certain area is arranged on the inner wall of the secondary descaling drum, a cylindrical wall composed of a circular hole punching plate is arranged on the third descaling drum, a long spiral belt is arranged on the cylindrical wall, and a plurality of axially arranged threaded steel bars are arranged on the empty wall of each spiral belt lead, a layer of convex abrasive sand skin is laid on the cylindrical inner wall of the cylindrical flange connection A, and a pushing blade is arranged along the circumference of the cylindrical inner wall of the cylindrical flange connection B; the axial pusher A and the axial pusher B each include an arc-shaped connecting piece arranged at the outermost edge of the outer edge large spiral blade, a connecting rod type supporting structure assembly and a sleeve; the sleeve is connected to the outer edge large spiral blade through the supporting structure assembly; the gap between the arc-shaped connecting piece and the inner wall of the descaling multi-stage drum assembly is much smaller than the outer size of the fish body. The invention can optimally select and intelligently adjust the technical parameters such as the rotation speed of the shaft propeller and the rotation speed of the descaling drum according to the different species and sizes of the processed fish, so as to achieve the optimal matching effect of the pushing speed, processing time and descaling intensity of the processed fish, and realize the convenience and intelligence of the operation and control of the descaling equipment, so that the descaling of the processed fish is higher in cleanliness, better in uniformity, lower in damage rate and better in quality of the finished product. However, this mechanical descaling method will damage the fish, reduce the quality and yield of the fish fillets, and reduce the production rate of the fish fillets. Summary of the invention

[0004] Therefore, in view of the above-mentioned problems, the present invention provides a method for descaling and back-opening fish, which solves the defects of the prior art method for descaling and back-opening fish, such as low production efficiency and mechanical damage to the fish body.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for descaling and back-opening fish comprises the following steps:

[0007] (1) Rinse the fish thoroughly;

[0008] (2) Soaking in a descaling solution: Prepare a descaling solution containing a composite enzyme, and soak the fish in the descaling solution for 20-30 minutes. The composite enzyme is composed of collagenase and pepsin in a weight ratio of 1:1-3. The temperature of the descaling solution is controlled at 35-39° C., the pH of the descaling solution is 6.5-8.0, and the concentration of the composite enzyme is 1-3 mg / ml.

[0009] (3) Washing: The fish body that has been soaked in step (2) is washed with high-pressure water to remove fish scales;

[0010] (4) Open back treatment.

[0011] Further: The enzymatic activity of collagenase is 50-200 U / mg.

[0012] Furthermore: the enzymatic activity of the pepsin is 100-200 U / mg.

[0013] Furthermore, the back-opening process of step (4) is as follows: the fish body is sent into a back-opening machine for back-opening, the back-opening machine comprises a frame, a conveyor belt arranged on the frame, a tray for holding the fish is arranged on the conveyor belt, a cutter is arranged above the frame, the cutter forms an angle of 20-45° with the horizontal position of the fish body, and a driving device for controlling the cutter to move up and down in the longitudinal direction is also arranged on the side of the frame. After the fish body is placed in the tray, it is transmitted online via the conveyor belt, and the cutter on the frame cuts the fish body for back-opening, and the cutting frequency and cutting depth of the cutter are pre-set by an external control system.

[0014] Furthermore: a pretreatment is performed before step (2), wherein the pretreatment is performed by soaking in vinegar for 5-10 minutes.

[0015] Furthermore, the descaling liquid also contains 0.1-0.5wt% of tea polyphenols.

[0016] Furthermore: the tea polyphenols are in powder form.

[0017] By adopting the above technical solution, the beneficial effects of the present invention are:

[0018] 1. Compared with mechanical descaling, the descaling method of the present invention has more advantages, such as more thorough descaling, less damage to the fish body, and the ability to maintain the original luster and muscle tissue structure of the fish body. The present invention uses a combination of collagenase and pepsin, which can degrade the connecting tissue between fish scales and fish skin, making the fish scales easier to fall off, and then the high-pressure water gun is used to spray and wash the fish scales to further fall off.

[0019] 2. The temperature of the descaling solution used in the present invention is controlled at 35-39°C, and the pH of the descaling solution is 6.5-8.0. Within this range, the enzyme can exhibit optimal activity. At this temperature, the molecular structure of the enzyme is most stable and can more effectively bind to the substrate and catalyze the reaction.

[0020] 3. The cutting knife used for back opening is at an angle of 20-45° to the horizontal position of the fish body, which can better fit the curve of the fish's back during cutting, making the cutting smoother and improving production efficiency.

[0021] 4. Furthermore, soaking the fish in vinegar before descaling can facilitate the removal of scales and also have a certain degree of deodorizing effect.

[0022] 5. Adding a small amount of tea polyphenols to the descaling liquid can reduce the oxidative damage to the fish body during the descaling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a back opening machine in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] Embodiment 1

[0025] refer to Figure 1 The method for descaling and back-opening of breeding fish comprises the following processing steps:

[0026] (1) Rinse the fish thoroughly;

[0027] (2) Soaking in descaling liquid: Prepare a descaling liquid containing a composite enzyme, and soak the fish in the descaling liquid for 20 minutes. The composite enzyme is composed of collagenase and pepsin in a weight ratio of 1:1. The temperature of the descaling liquid is controlled at 35°C, the pH of the descaling liquid is 6.5, the concentration of the composite enzyme is 1 mg / ml, the enzyme activity of the collagenase is 50 U / mg, and the enzyme activity of the pepsin is 100 U / mg;

[0028] (3) Washing: The fish body that has been soaked in step (2) is washed with high-pressure water to remove fish scales;

[0029] (4) Back-opening: The fish body is sent into a back-opening machine for back-opening. The back-opening machine includes a frame 1, a conveyor belt 2 arranged on the frame 1, a tray 3 for holding fish is arranged on the conveyor belt 2, a cutter 4 is arranged above the frame 1, and the cutter 4 forms an angle of 20° with the horizontal position of the fish body. The side of the frame 1 is also provided with a driving device 5 for controlling the cutter to move up and down in the longitudinal direction. After the fish body is placed in the tray 3, it is transmitted online via the conveyor belt 2, and the cutter 4 on the frame 1 cuts the fish body for back-opening. The cutting frequency and cutting depth of the cutter are pre-set by an external control system and are specifically set according to the species and size of the fish. The driving device is a known device such as an air cylinder or an oil cylinder, which will not be described here.

[0030] Embodiment 2

[0031] A method for descaling and back-opening fish comprises the following steps:

[0032] (1) Rinse the fish thoroughly;

[0033] (2) pretreatment, wherein the pretreatment is performed by soaking in vinegar for 7 minutes;

[0034] (3) Soaking in descaling liquid: Prepare a descaling liquid containing a composite enzyme, and soak the fish in the descaling liquid for 25 minutes. The composite enzyme is composed of collagenase and pepsin in a weight ratio of 1:2. The temperature of the descaling liquid is controlled at 37°C, the pH of the descaling liquid is 6.8, the concentration of the composite enzyme is 2 mg / ml, the enzyme activity of the collagenase is 100 U / mg, and the enzyme activity of the pepsin is 150 U / mg.

[0035] (4) Washing: The fish body that has been soaked in step (3) is washed with high-pressure water to remove fish scales;

[0036] (5) Back opening treatment: The specific treatment method is the same as that in the first embodiment.

[0037] Embodiment 3

[0038] A method for descaling and back-opening fish comprises the following steps:

[0039] (1) Rinse the fish thoroughly;

[0040] (2) pretreatment, wherein the pretreatment is performed by soaking in vinegar for 10 minutes;

[0041] (3) Soaking in descaling liquid: Prepare a descaling liquid containing a composite enzyme, and soak the fish in the descaling liquid for 30 minutes. The composite enzyme is composed of collagenase and pepsin in a weight ratio of 1:3. The temperature of the descaling liquid is controlled at 39°C, the pH of the descaling liquid is 8.0, and the concentration of the composite enzyme is 3mg / ml; the enzyme activity of collagenase is 200U / mg. The enzyme activity of pepsin is 200U / mg. The descaling liquid also contains 0.5wt% of tea polyphenols. The tea polyphenols are in powder form;

[0042] (4) Washing: The fish body that has been soaked in step (2) is washed with high-pressure water to remove fish scales;

[0043] (5) Back opening process: Referring to Example 1, except for the different horizontal angles between the cutting knife and the fish body, other processing methods are the same as those in Example 1. In this embodiment, the horizontal angle between the cutting knife and the fish body is 40°.

[0044] Five assessors were invited to evaluate the fish bodies processed by the embodiments of the present invention. The fish body tissue morphology of embodiments 1 to 3 were: no wounds, no missing meat, firm and elastic muscles, and no fish scales.

[0045] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A method for descaling and back-opening a fish, characterized in that: The processing steps include: (1) Rinse the fish thoroughly; (2) Soaking in a descaling solution: Prepare a descaling solution containing a composite enzyme, and soak the fish in the descaling solution for 20-30 minutes. The composite enzyme is composed of collagenase and pepsin in a weight ratio of 1:1-3. The temperature of the descaling solution is controlled at 35-39° C., the pH of the descaling solution is 6.5-8.0, and the concentration of the composite enzyme is 1-3 mg / ml. (3) Washing: The fish body that has been soaked in step (2) is washed with high-pressure water to remove fish scales; (4) Open back treatment.

2. A fish descaling and back-opening processing method according to claim 1, characterized in that: The enzymatic activity of collagenase is 50-200 U / mg.

3. A fish descaling and back-opening processing method according to claim 1, characterized in that: The enzymatic activity of the pepsin is 100-200 U / mg.

4. A fish descaling and back-opening processing method according to claim 1, characterized in that: The back-opening process of step (4) is as follows: the fish body is sent into a back-opening machine for back-opening processing, the back-opening machine comprises a frame, a conveyor belt arranged on the frame, a tray for holding the fish is arranged on the conveyor belt, a cutter is arranged above the frame, the cutter and the horizontal position of the fish body form an angle of 20-45°, and the side of the frame is also provided with a driving device for controlling the cutter to move up and down in the longitudinal direction. After the fish body is placed in the tray, it is transmitted online via the conveyor belt, and the cutter on the frame cuts the fish body for back-opening processing, and the cutting frequency and cutting depth of the cutter are pre-set by an external control system.

5. The method for descaling and back-opening a fish according to claim 1, characterized in that: Before step (2), a pretreatment is performed, wherein the pretreatment is performed by soaking in vinegar for 5-10 minutes.

6. The method for descaling and back-opening a fish according to claim 1, characterized in that: The descaling liquid also contains 0.1-0.5wt% of tea polyphenols.

7. A fish descaling and back opening processing method according to claim 6, characterized in that: The tea polyphenols are in powder form.

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