A method for freezing pre-prepared grass carp fillets

Abstract

The present application relates to a kind of frozen pre-made grass carp fillets method, belong to food preservation technical field.The frozen pre-made grass carp fillets method disclosed in the present application, mainly using quality improvement liquid (including: 3~4% collagen gel liquid, 0.4~0.6% glutamine transaminase (TG enzyme), 2~4% salt according to weight percentage) is injected into fish meat to be pickled.Then subsequent processing can be done, the salt in the quality improvement liquid can promote the unfolding of myofibrillar protein structure in fish meat, collagen gel liquid can fill the intercellular pores left after myofibrillar protein structure changes, glutamine transaminase can regulate the crosslinking degree and thermal stability of collagen gel to make it have the characteristics of intermuscular matrix protein, the above effects can inhibit the damage of fish meat cells and protein structure caused by endogenous enzymes and ice crystals during freeze-thaw process.The method used in the present application can reduce the quality deterioration of fish meat during freeze-thaw process, so that the fish meat can maintain better taste after frozen storage.

Description

Technical Field

[0001] The invention belongs to the technical field of food preservation and relates to a method for freezing prefabricated grass carp fillets. Background Art

[0002] Grass carp is an important freshwater fish species in my country, accounting for one-fifth of my country's total freshwater aquaculture production. Due to its high moisture content, which favors microbial growth, and its high endogenous enzyme activity, the texture and quality of its flesh can easily deteriorate after slaughter.

[0003] Frozen storage is the most common method for preserving fish quality. It inhibits microbial growth and reproduction, reduces endogenous enzyme activity, and prolongs shelf life. However, factors such as freezing temperature, storage time, freezing rate, and repeated freeze-thaw cycles caused by temperature fluctuations can affect ice crystal growth and protein denaturation in the fish. Consequently, frozen grass carp loses its tenderness after cooking, becoming hard and tough, with a spongy texture and brittleness during cooking. Currently, methods such as polyphosphate water retention are commonly used to improve fish texture, but these have been unsatisfactory for major freshwater fish like grass carp.

[0004] In grass carp meat, myofibrillar proteins account for 60%-70%, sarcoplasmic proteins for 20%-35%, and matrix proteins for 2%-5%. Matrix proteins are primarily found in the extracellular connective tissues of the endomysium, perimysium, and epimysium, respectively, which encase myofibers, myofibril bundles, and muscle. Although their content is far lower than that of myofibrils, they play a crucial role in maintaining muscle integrity and mechanical properties. During storage, the separation of connective tissue and myofibers, as well as the degradation of matrix proteins, are key factors affecting the texture of grass carp fillets after steaming.

[0005] Collagen is the most important matrix protein in the connective tissue of grass carp meat, so it is necessary to provide a method for preparating high-quality grass carp. Summary of the Invention

[0006] In view of this, an object of the present invention is to provide a method for freezing prefabricated grass carp fillets.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] 1. A method for freezing prefabricated grass carp fillets, wherein a quality improvement liquid is injected into the grass carp meat for pickling, wherein the quality improvement liquid comprises, by weight percentage, 3-4% collagen gel liquid, 0.4-0.6% transglutaminase (TGase), and 2-4% salt.

[0009] Preferably, the quality improving liquid is prepared by the following method: heating and melting the collagen gel liquid with a mass fraction of 3-4%, adding a solution of transglutaminase (TGase) with a mass fraction of 0.4-0.6% and a salt water with a mass fraction of 2-4%, and stirring to obtain a uniform quality improving liquid.

[0010] The volume-mass ratio of the collagen gel liquid, transglutaminase (TGase) and salt is 1000:4:30, mL:g:g.

[0011] Further preferably, the collagen gel liquid is prepared by the following method:

[0012] (1) trimming: hot washing the fresh collagen-rich raw material to remove dirt, scraping the subcutaneous fat after scraping the hair roots to obtain a trimmed raw material;

[0013] (2) steaming pretreatment: heating the trimmed raw material to above 90°C after adding water to steam / boil until the structure is loose and soft;

[0014] (3) high-speed mechanical shear micronization: continuously shearing and refining the trimmed raw material to a diameter of 30-50 μm using a colloid mill to obtain a collagen protein aqueous solution, and continuously adding water during the grinding process to make the collagen protein content in the collagen protein aqueous solution 3-4% by weight;

[0015] (4) high-pressure jet homogenization: high-pressure homogenization pretreatment of the collagen protein aqueous solution, followed by micro-jet refinement homogenization to remove bubbles and impurities to obtain a collagen gel liquid with a collagen mass fraction of 3-4%.

[0016] Further preferably, the fresh collagen-rich raw material includes pigskin or cowhide.

[0017] Preferably, the method specifically includes the following steps:

[0018] (1) grass carp pretreatment: scaling, gutting, finning, decapitating, and removing bone spurs from the grass carp, and then washing to remove blood and internal membranes to obtain pretreated grass carp meat;

[0019] (2) injection curing: injecting the quality improving liquid into the pretreated grass carp meat to obtain cured fish meat, and the mass ratio of the quality improving liquid to the pretreated grass carp meat is 20-30%;

[0020] (3) vacuum tumbling: placing the cured fish meat in a vacuum tumbling machine, tumbling for 10-20 min under a vacuum degree of 60-80 kPa, and then vacuum sealing and packaging;

[0021] (4) water bath heating: heating in a water bath at 35-40°C for 30-40 min, and then cooling in ice water;

[0022] (5) Equilibration: Equilibrate in air at 4-6°C for 3-6 hours;

[0023] (6) Low-temperature quick freezing: the balanced fish meat is cut into fillets with a thickness of 2.5 to 3.5 mm and then promptly put into a -40°C quick freezer for freezing. During the freezing process, the center temperature of the product drops to below -25°C within 15 to 20 minutes. After freezing, the fillets are placed in clean cold water for instant immersion in ice coating;

[0024] (7) Vacuum packaging and low-temperature storage: The fish fillets that have been quick-frozen at low temperatures are placed in polyethylene film bags, vacuum-sealed, and stored in a -18°C refrigerator.

[0025] The beneficial effects of the present invention are as follows: the present invention discloses a method for freezing prefabricated grass carp fillets, which mainly adopts a quality improvement liquid (including 3-4% collagen gel liquid, 0.4-0.6% transglutaminase (TG enzyme), and 2-4% salt in terms of weight percentage) to be injected into the fish meat for pickling. Then subsequent treatment is sufficient. The salt in the quality improvement liquid can promote the unfolding of the myofibrillar protein structure in the fish meat, the collagen gel liquid can fill the intercellular pores left after the myofibrillar protein structure is changed, and the transglutaminase can improve the cross-linking degree and thermal stability of the collagen gel so that it has the characteristics of intermuscular matrix protein. The above effects can inhibit the protein structure damage caused by endogenous enzymes and ice crystals in the freeze-thaw process of the fish meat. Therefore, the method adopted by the present invention can reduce the quality deterioration of the fish meat during the freeze-thaw process, so that the fish meat can maintain a better taste after frozen storage.

[0026] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0028] Figure 1 The control group was fish fillets cooked in boiling water for 10 min;

[0029] Figure 2 For the experimental group, the fish fillets were steamed in boiling water for 10 min;

[0030] Figure 3 This is a comparison of fish cells in the control group and the experimental group before and after freezing. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] Example 1

[0033] A method for freezing prefabricated grass carp fillets comprises the following steps:

[0034] (1) Pretreatment of grass carp: Descaling, removing internal organs, fins, head, and bones of the grass carp, and then washing away bloody endothelium to obtain pretreated grass carp meat;

[0035] (2) Injection marinating: the quality improvement solution (prepared as follows) is added in a mass ratio of 1:5: 3% collagen gel solution (prepared as follows: a. trimming: the fresh collagen-rich raw material is blanched to remove dirt, and the hair roots and subcutaneous fat are scraped off to obtain the trimmed raw material; b. steaming pretreatment: the trimmed raw material is added with water and heated to above 90°C and steamed until the structure is loose and soft; c. high-speed mechanical shearing micronization: the colloid mill is continued to be used for high-speed shearing to obtain a collagen aqueous solution with a diameter of 30 to 50 μm. Water is added to make the weight percentage of collagen in the collagen aqueous solution be 3%; d. high-pressure jet homogenization: the collagen aqueous solution is pretreated by high-pressure homogenization, and then refined and homogenized by microjet to remove bubbles and impurities to obtain a collagen gel liquid with a collagen mass percentage of 3%), which is melted by heating in warm water, and a solution formed by 0.4% glutamine transaminase (TG enzyme) dissolved in water and 3% saline solution are added, and stirred to make it uniform to obtain a quality-improving liquid) which is injected into the pretreated grass carp meat to obtain marinated fish meat.

[0036] (3) Vacuum tumbling: placing the marinated fish meat in a vacuum tumbling machine, tumbling for 15 minutes under a vacuum degree of 60 kPa, and then vacuum sealing and packaging;

[0037] (4) Water bath heating: Heat in a 40°C water bath for 30 min and then cool in ice water;

[0038] (5) Equilibration: Equilibrate in air at 4°C for 3 h;

[0039] (6) Low temperature quick freezing: after cutting the balanced fish meat without parasites into fish slices with thickness of 2.5-3.5 mm, the fish slices are sent into a -40℃ quick freezer for freezing, and the center temperature of the product should be quickly reduced to below -25℃ within 20 min during the freezing process, and after the freezing is completed, the fish slices are instantaneously immersed in clean cold water for ice coating;

[0040] (7) Vacuum packaging and low temperature storage: the fish slices after low temperature quick freezing are packed into polyethylene film bags for vacuum sealing and packaging, and are stored in a -18℃ refrigerator.

[0041] Example 2

[0042] A method for freezing pre-prepared grass carp slices, specifically comprising the following steps:

[0043] (1) Grass carp pretreatment: after the grass carp is scaled, eviscerated, finned, headed and bone-sticked, the blood and inner membrane are washed to obtain pretreated grass carp meat;

[0044] (2) Injection pickling: according to a mass ratio of 1:4, the quality improvement liquid (prepared according to the following method: 3.5% collagen gel liquid (prepared according to the following method: a, trimming: after the fresh collagen-rich raw material is hot washed to remove dirt, the hair roots are scraped off, and the subcutaneous fat is scraped off to obtain the trimmed raw material; b, steaming pretreatment: after the trimmed raw material is added with water, it is heated to above 90℃ and steamed until the structure is loose and soft; c, high-speed mechanical shearing and micronization: the collagen protein water solution is obtained by continuously shearing and refining the collagen protein water solution to a diameter of 30-50 μm by using a colloid mill, and water is continuously added to make the weight percentage of collagen protein in the collagen protein water solution 3%; d, high-pressure jet homogenization: after the collagen protein water solution is pretreated by high-pressure homogenization, it is refined and homogenized by micro-jet to remove bubbles and impurities to obtain a collagen gel liquid with a mass percentage of 3.5% collagen; ) is heated and melted in warm water, 0.5% transglutaminase (TG enzyme) solution and 2% salt water are added, and stirring is performed to make them uniform to obtain the quality improvement liquid; and the pretreated grass carp meat is injected to obtain the pickled fish meat.

[0045] (3) Vacuum tumbling: the pickled fish meat is placed in a vacuum tumbling machine, tumbled for 15 min under a vacuum degree of 60 kpa, and then vacuum sealed and packaged;

[0046] (4) Water bath heating: heated in a 40℃ water bath for 30 min and then cooled in ice water;

[0047] (5) Balancing: balanced in 5℃ air for 5 h;

[0048] (6) Low-temperature quick freezing: Cut the parasite-free, balanced fish into fillets with a thickness of 2.5 to 3.5 mm and promptly place them in a -40°C quick freezer for freezing. During the freezing process, the core temperature of the product should drop rapidly to below -25°C within 15 minutes. After freezing, place the fillets in clean cold water for an instant immersion in ice.

[0049] (7) Vacuum packaging and low-temperature storage: The fish fillets that have been quick-frozen at low temperatures are placed in polyethylene film bags, vacuum-sealed, and stored in a -18°C refrigerator.

[0050] Example 3

[0051] A method for freezing prefabricated grass carp fillets comprises the following steps:

[0052] (1) Pretreatment of grass carp: Descaling, removing internal organs, fins, head, and bones of the grass carp, and then washing away bloody endothelium to obtain pretreated grass carp meat;

[0053] (2) Injection marinating: the quality improvement solution (prepared as follows) is added in a mass ratio of 3:10: 4% collagen gel solution (prepared as follows: a. trimming: the fresh collagen-rich raw material is blanched to remove dirt, and the hair roots and subcutaneous fat are scraped off to obtain the trimmed raw material; b. steaming pretreatment: the trimmed raw material is added with water and heated to above 90°C and cooked until the structure is loose and soft; c. high-speed mechanical shearing micronization: the colloid mill is continued to be used for high-speed shearing to obtain a collagen aqueous solution with a diameter of 30 to 50 μm. Water is added to make the weight percentage of collagen in the collagen aqueous solution be 3%; d. high-pressure jet homogenization: the collagen aqueous solution is pretreated by high-pressure homogenization, and then refined and homogenized by microjet to remove bubbles and impurities to obtain a collagen gel liquid with a collagen mass percentage of 3%), which is melted by heating in warm water, and a solution formed by 0.6% glutamine transaminase (TG enzyme) dissolved in water and 4% saline solution are added, and stirred to make it uniform to obtain a quality-improving liquid) which is injected into the pretreated grass carp meat to obtain marinated fish meat.

[0054] (3) Vacuum tumbling: placing the marinated fish meat in a vacuum tumbling machine, tumbling for 15 minutes under a vacuum degree of 60 kPa, and then vacuum sealing and packaging;

[0055] (4) Water bath heating: Heat in a 35°C water bath for 40 min and then cool in ice water;

[0056] (5) Equilibration: Equilibrate in air at 6°C for 6 h;

[0057] (6) Low-temperature quick freezing: Cut the parasite-free, balanced fish into fillets with a thickness of 2.5 to 3.5 mm and immediately place them in a -40°C quick freezer for freezing. During the freezing process, the center temperature of the product should drop rapidly to below -25°C within 18 minutes. After freezing, place the fillets in clean cold water for an instant immersion in ice.

[0058] (7) Vacuum packaging and low-temperature storage: The fish fillets that have been quick-frozen at low temperatures are placed in polyethylene film bags, vacuum-sealed, and stored in a -18°C refrigerator.

[0059] Performance testing

[0060] The following performance tests were performed using the grass carp slices treated with the method of Example 1 as the experimental group and fresh grass carp meat slices as the control group, as described below:

[0061] 1. Full Texture Measurement: Wrap 3.5mm thick grass carp fillets in a heat-resistant polyethylene retort bag and heat in a boiling steamer for 10 minutes. After heating, quickly cool the fillets with ice water and store at 4°C for testing. Wipe the surface of the fish dry with filter paper before testing. Cut the cooked grass carp fillets into 20 x 15mm rectangles. Use a 50mm TA25 cylindrical probe. Pre-test speed: 2mm / s, post-test speed: 5mm / s, test speed: 1mm / s, interval between compressions: 5s, compression ratio: 40%, return position: 10mm. Select five replicates for each group, discarding the maximum and minimum values.

[0062] 2. Shear force determination: Wrap grass carp fillets with a thickness of 3.5mm in a high-temperature resistant polyethylene cooking bag, place in a boiling steamer, and heat for 10 minutes. After heating, quickly cool the fillets with ice water and place at 4°C for testing. Before testing, wipe the surface moisture of the fish with filter paper. Cut the fillets into uniform sizes (40×30×3.5mm) and place them on the test table of the texture analyzer, with the direction of the muscle fibers perpendicular to the direction of the test blade (A-MORS). The test conditions are:

[0063] The shear force is defined as the maximum value when the fish meat compression ratio is 90%, and the unit is g. Five parallel samples are taken for each group, and the maximum and minimum values ​​are removed.

[0064] 3. Fiber Tensile Test: Wrap 3.5mm thick grass carp fillets in a heat-resistant polyethylene retort bag and place in a boiling steamer for 10 minutes. After heating, rapidly cool the fillets with ice water and store at 4°C for testing. Wipe the surface of the fish dry with filter paper before testing. Cut the grass carp fillets into 20mm x 15mm strips. On a texture analyzer platform, set the measurement mode to A-KIE, set the test conditions to: pre-test speed of 10mm / s, test speed of 5mm / s, post-test speed of 5mm / s, and trigger force of 10g. Select five replicates for each group, and discard the maximum and minimum values.

[0065] 4. Water Holding Capacity Determination: Wipe the surface moisture from the fish with filter paper and weigh it (W1). Wrap the treated fish with filter paper and place two layers of filter paper at the bottom of a centrifuge tube. Centrifuge at 2000g for 10 minutes at room temperature. After centrifugation, weigh the fish (W2). The water holding capacity of the fish is measured by the centrifugal loss rate. A higher centrifugal loss rate indicates a lower water holding capacity.

[0066] Centrifugal loss rate (%) = (W1-W2)W1×100%

[0067] 5. Determination of cooking loss rate: Weigh the fish to be heated before steaming (W1). After heating, quickly cool the fish fillets with ice water. Use filter paper to wipe the surface moisture of the fish fillets that have cooled to room temperature, and weigh the fish again (W2). The cooking loss rate is calculated as follows:

[0068] Cooking loss rate (%) = (W1-W2) / W1×100%

[0069] 6. Determination of moisture content: Determined in accordance with GB 5009.3-2016.

[0070] 7. Results Analysis

[0071] The control group used in the above test process was fresh grass carp slices. The fish fillets were divided into two groups: one group was directly tested for indicators, and the other group was frozen for 15 days before the indicators were tested. The experimental group was fish fillets prepared according to the method of Example 1. The fish fillets were divided into two groups: one group was directly tested for indicators, and the other group was frozen for 15 days before the indicators were tested. The specific test results are shown in Table 1:

[0072] Table 1 Performance test results of the control group and experimental group

[0073]

[0074]

[0075] Figure 1 The control group was fish fillets cooked in boiling water for 10 minutes, Figure 2fish fillets of the experimental group are boiled in boiling water for 10 minutes, Figure 3 The contrastive diagram of fish muscle cells before and after frozen storage for the control group and the experimental group is shown in Figure 2. Figures 1 to 3 It can be obviously seen that the filling effect of the experimental group on the simulated intercellular matrix protein of the fish muscle before frozen storage is better, and the fish muscle cells of the experimental group after frozen storage are more complete and compact. As shown in Table 1, the fish fillets of the control group and the experimental group are boiled in boiling water for 10 minutes, and then the indexes are measured. As shown in Table 1, because the pigskin gel modified by TG enzyme crosslinking can absorb water and swell and is heat irreversible, the thickness of the fish fillets of the experimental group after boiling is larger than that of the control group, and the chewiness, gumminess, elasticity and cohesiveness are significantly increased. The boiling loss rate is significantly reduced, the water holding capacity is significantly increased, the fish fillets are juicy and delicate. The tensile force and tensile distance are increased, and the toughness and ductility of the fish fillets are better.

[0076] However, these evaluation indexes are not the larger the better. The hardness, chewiness, gumminess, elasticity and cohesiveness of the fish muscle of the control group after frozen storage for 15 days are significantly increased, the water content is reduced, the taste is sponge-like, the shear force is significantly increased, the tenderness is reduced, and the taste is rough, dry and hard.

[0077] The boiling loss rate of the fish fillets of the experimental group after frozen storage is lower, the fish fillets are thicker, and the texture-related indexes such as chewiness, gumminess and cohesiveness have no significant difference compared with those before frozen storage, and the toughness, ductility index and tenderness have no significant difference compared with those before frozen storage, that is, the texture characteristics before frozen storage are better maintained. Although there is a certain loss of juice during frozen storage, the total water content is still higher than that of the control group without treatment, and the boiling loss rate is also lower. Therefore, the fish fillets of the experimental group after frozen storage also maintain a delicate and soft taste with rich juice. Therefore, it can be seen that the method adopted in the present application can reduce the quality deterioration of fish meat during the freezing and thawing process, so that the fish meat can maintain a better taste after frozen storage.

[0078] Similarly, the performance test of Example 2 and Example 3 is carried out, and the results are similar to those of Example 1, which proves that the treatment method under different conditions can also ensure the treatment effect.

[0079] In summary, the present invention discloses a method for freezing prefabricated grass carp fillets, which mainly adopts a quality improvement liquid (including 3% collagen gel liquid, 0.4% transglutaminase (TG enzyme), and 3% salt in terms of weight percentage) to be injected into the fish meat for pickling. Then subsequent treatment is required. The salt in the quality improvement liquid can promote the unfolding of the myofibrillar protein structure in the fish meat, the collagen gel liquid can fill the intercellular pores left after the myofibrillar protein structure is changed, and the transglutaminase can improve the cross-linking degree and thermal stability of the collagen gel so that it has the characteristics of intermuscular matrix protein. The above effects can inhibit the destruction of the protein structure caused by endogenous enzymes and ice crystals in the freeze-thaw process of the fish meat. Therefore, the method adopted by the present invention can reduce the quality deterioration of the fish meat during the freeze-thaw process, so that the fish meat can maintain a better taste after frozen storage.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for freezing pre-made grass carp fillets, characterized in that: In the method, a quality improvement liquid is injected into grass carp meat for pickling, wherein the quality improvement liquid comprises collagen gel liquid, glutamine transaminase, and salt in percentage by weight; The quality improvement solution is prepared as follows: a collagen gel solution having a mass fraction of 3-4% is heated in water to melt, a solution having a mass fraction of 0.4-0.6% transglutaminase dissolved in water and a solution having a mass percentage of 2-4% saline are added, and the mixture is stirred to obtain a uniform quality improvement solution. The method specifically comprises the following steps: (1) Pretreatment of grass carp: remove the scales, internal organs, fins, head, and bones of the grass carp, and then wash away the bloody inner membrane to obtain the pretreated grass carp meat; (2) Injection marinating: injecting the quality improvement liquid into the pretreated grass carp meat to obtain marinated fish meat, wherein the mass ratio of the quality improvement liquid to the pretreated grass carp meat is 20-30%; (3) Vacuum tumbling: placing the marinated fish meat in a vacuum tumbling machine, tumbling for 10 to 20 minutes under a vacuum degree of 60 to 80 kPa, and then vacuum sealing and packaging; (4) Water bath heating: Heat in a water bath at 35-40°C for 30-40 minutes and then cool in ice water; (5) Equilibration: Equilibrate in air at 4-6°C for 3-6 hours; (6) Low-temperature quick freezing: the balanced fish meat is cut into fillets with a thickness of 2.5-3.5 mm and then promptly put into a -40°C quick freezer for freezing. During the freezing process, the center temperature of the product drops below -25°C within 15-20 minutes. After freezing, the fillets are placed in clean cold water for instant immersion in ice coating. (7) Vacuum packaging and low-temperature storage: The fish fillets after low-temperature quick freezing are placed in polyethylene film bags, vacuum-sealed and stored in a -18°C refrigerator; The volume-to-mass ratio of the collagen gel solution, transglutaminase, and salt is 1000:4:30, mL:g:g.

2. The method according to claim 1, characterized in that The collagen gel solution was prepared as follows: (1) Trimming: The fresh collagen-rich raw material is blanched to remove dirt, and the hair roots and subcutaneous fat are scraped off to obtain the trimmed raw material; (2) Steaming pretreatment: adding water to the trimmed raw materials and heating to above 90° C. and steaming / cooking until the structure is loose and soft; (3) High-speed mechanical shearing and micronization: Continue to use colloid mill to shear and refine to a diameter of 30-50 μm to obtain a collagen aqueous solution. During the grinding process, water is continuously added to make the weight percentage of collagen in the collagen aqueous solution 3-4%; (4) High-pressure jet homogenization: The collagen aqueous solution is pre-treated by high-pressure homogenization, and then refined and homogenized by microjet to remove bubbles and impurities to obtain a collagen gel solution with a collagen mass percentage of 3-4%.

3. The method according to claim 2, characterized in that The fresh collagen-rich raw material includes pig skin or cow skin.

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