Preparation process of animal protein product capable of improving texture uniformity

Abstract

The invention discloses a preparation technology of an animal protein product capable of improving texture uniformity, and belongs to the technical field of animal protein product processing. The process comprises the following steps: S1, putting animal meat paste into a chopping and mixing pot, keeping the temperature of the chopping and mixing pot to be less than or equal to 5 DEG C, mixing and chopping the animal meat paste with 60-70% of formula amount of ice water, and chopping and mixing at 1200rpm for 3-5 minutes to form a protein continuous phase so as to obtain a fine meat paste base; s2, cassava starch and ice water with the amount being 20%-30% of the formula amount are premixed into turbid liquid, the turbid liquid is added into the fine and smooth meat paste base to be chopped and mixed at the speed of 800 rpm for 2-3 minutes, the protein continuous phase is filled with the cassava starch, and a starch filling phase is obtained; and S3, premixing the soybean protein with the remaining formula amount of ice water, adding the mixture obtained in the step S2, and chopping at 500rpm for 1-2 minutes to obtain the meat paste with uniform texture. The method can improve the texture uniformity of the animal protein product.

Description

Technical Field

[0001] This invention relates to the field of animal protein product processing technology, and specifically to a preparation process for animal protein products that improves texture uniformity. Background Technology

[0002] In traditional processing, mixing fish paste with auxiliary materials such as tapioca starch and soy protein often results in problems such as stratification and a coarse texture. The reasons are as follows: 1. Narrow gelatinization window of tapioca starch: The gelatinization temperature of tapioca starch is 58-65℃, while the traditional pounding process generates heat through friction, causing large temperature fluctuations, often reaching 15-25℃, far below the gelatinization temperature. The starch cannot fully absorb water and swell, existing as hard granules, resulting in a coarse texture. Even with later heating for gelatinization, the amylose in tapioca starch easily ages and releases water upon cooling, squeezing out water from the gel network, leading to starch-protein phase separation. White starch granules are visible on the cut surface, resulting in a grainy texture. 2. Competition for water between tapioca starch gelatinization and animal protein: Fish paste contains salt-soluble proteins, mainly myosin. Myosin requires a large amount of free water for hydration. The amount of tapioca starch added is usually 5-15%. If the traditional process involves adding the materials all at once, it will absorb water instantly, causing a 20-30% decrease in animal protein extraction rate. The continuous phase network of animal protein cannot fully encapsulate the starch granules, resulting in starch sedimentation and stratification. 3. Incompatibility between soy protein and myosin, and difference in isoelectric point: The isoelectric point of soy protein is pH 4.5, while that of fish paste salt-soluble protein is pH 6.0-7.0. Traditional processes do not adjust the pH, resulting in less than 30% solubility of soy protein in the fish paste salt-soluble protein system. Undissolved protein particles create a "gritty" texture. 4. Gel mechanism conflict: Fish paste salt-soluble protein forms an elastic gel through thermally induced disulfide bond cross-linking, while soy protein forms a brittle gel through hydrogen bonds and hydrophobic interactions. If they are not fully co-soluble, they will separate and aggregate, macroscopically manifesting as uneven texture and stratification on the cut surface. 5. Insufficient chopping fineness in traditional processes: Fish meat particles must be <50μm. Fat is not sufficiently sheared and refined, resulting in excessively large fat globules. These large fat globules cannot be stably encapsulated by the continuous animal protein network, causing them to float and separate after standing. 6. Incorrect order of additive addition: If tapioca starch and oil are added simultaneously or in the wrong order, the oil will compete for water, hindering protein hydration and leading to solid-liquid-oil phase separation.

[0003] 6. pH deviation: The isoelectric point (pI) of myosin is approximately pH 5.0–5.5. Traditional processes do not adjust the pH. When pH < 6.0, the protein is close to its isoelectric point, has the lowest solubility, and the finished gel network is loose and inelastic. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, one of the objectives of the present invention is to provide a preparation process for animal protein products with improved texture uniformity, wherein the animal protein products prepared by the process have uniform texture.

[0005] The second objective of this invention is to provide a process for preparing protein products from salmon and cod skin.

[0006] The third objective of this invention is to provide an integrated production line for implementing the protein product preparation process of salmon and cod skin.

[0007] One of the objectives of this invention is achieved through the following technical solution: A process for preparing animal protein products with improved texture uniformity includes the following steps: S1. Place the animal meat paste in a chopping pot, keep the temperature of the chopping pot ≤5℃, and mix it with 60%-70% of the formula amount of ice water. Chop at 1200rpm for 3-5 minutes to form a continuous protein phase and obtain a fine meat paste base. S2. After premixing cassava starch with 20%-30% of the formula amount of ice water to form a suspension, add it to the fine minced meat base and chop it at 800 rpm for 2-3 minutes to fill the protein continuous phase with cassava starch and obtain the starch-filled phase. S3. After premixing the soy protein with the remaining amount of ice water, add it to the mixture from step S2 and chop at 500 rpm for 1-2 minutes to obtain a uniform meat paste.

[0008] Furthermore, after step S3, step S4 is also included: after the uniformly textured minced meat is extruded and shaped, it is quick-frozen at -35°C or below to obtain frozen minced meat blocks; the quick-freezing equipment adopts fluidized bed or spiral quick-freezing, freezing at -35°C to -45°C until the core temperature is ≤-18°C, and the freezing time is ≤30 minutes. S5. The frozen minced meat blocks are precisely sliced ​​and dried to complete dehydration, color fixation, and sterilization. S6. Perform final aseptic packaging in a clean environment to obtain the animal protein product with improved texture uniformity.

[0009] Furthermore, in step S1, the animal meat paste is salmon paste or chicken paste.

[0010] Furthermore, in step S5, the drying process employs a three-stage drying process, specifically, the drying is carried out sequentially at 50-60℃, 60-65℃, and 80-90℃.

[0011] Furthermore, the soybean protein is soaked in cold water at a ratio of 1:4-6 for 30-45 minutes before being premixed with ice water; the cassava starch is pregelatinized at 65-70°C for 10-15 minutes before being premixed with ice water.

[0012] Furthermore, in step S1, 0.2-0.3% by mass of polyphosphate is added to the chopping pot to adjust the pH of the system to 7.0-7.5.

[0013] Furthermore, between step S1 and step S2, the process includes: emulsifying the fat-soluble functional ingredients with ice water at high speed to form a stable emulsion, which is then added to the fine minced meat base for chopping; the high-speed emulsification is carried out at 8000–12000 rpm for 2–5 minutes, and the emulsification temperature is controlled at ≤10℃; the fat-soluble functional ingredients include vitamin E and rosemary extract.

[0014] The second objective of this invention is achieved by the following technical solution: The process for preparing protein products from salmon and cod skin involves the following steps: Cod skin, after being scaled, cleaned, and softened, is laid flat on the bottom of a food-grade mold with a thickness of 0.8–1.5 mm. The uniformly textured salmon paste obtained from this process is extruded and then spread onto the flatly laid cod skin, forming a layered structure. The uniformly textured salmon paste has a coverage thickness of 3–6 mm. The resulting salmon and cod skin protein products exhibit a clear layered structure. The salmon paste layer has a uniform texture, is free of granules, has a moisture content of 55–65%, and is sliced ​​to a thickness of 1.5–3.0 mm. Microbiological indicators comply with the GB10136 food safety standard.

[0015] Furthermore, The third objective of this invention is achieved by the following technical solution: The integrated production line for the preparation of protein products from salmon and cod skin includes: a low-temperature chopper, a high-speed emulsifying tank, an automatic extrusion molding machine, a cod skin laying robotic arm, a quick-freezing tunnel below -35℃, a high-precision freezing slicer, and a three-stage temperature-controlled intelligent drying room. Each unit is controlled in conjunction with a central PLC system.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention provides a preparation process for improving the texture uniformity of animal protein products, which involves group feeding and step-by-step chopping: by mixing and chopping the main ingredient animal meat paste, auxiliary ingredients cassava starch and soybean protein, as well as fat-soluble functional components (such as vitamin E and rosemary extract) at different stages, the uniform fusion of raw materials is ensured, and the problem of uneven texture of animal protein products is solved; ice water is used in steps S1, S2 and S3 to effectively suppress the temperature rise of the pounding, avoid thermal denaturation of myosin in the main ingredient animal meat paste, and increase the extraction rate of animal protein by 15-20%, and enhance the gel network strength of the protein continuous phase; by adding in a time-sequential gradient, the competitive hydration of myosin and auxiliary ingredients cassava starch and soybean protein is solved, and the synchronous water absorption is transformed into sequential hydration.

[0017] (2) The present invention provides a preparation process for animal protein products with improved texture uniformity, wherein fat-soluble functional components are pre-emulsified with ice water to form a stable microemulsion, avoiding direct addition that would disrupt the continuous protein phase and reducing the risk of stratification caused by oil precipitation.

[0018] Low-temperature chopping and rapid freezing combination: Utilizing low-temperature chopping combined with rapid freezing technology below -35℃ maximizes the preservation of the umami and nutrients of animal protein products, while minimizing flavor loss and nutrient degradation caused by high-temperature processing. The drying process employs a three-stage drying technique, ensuring effective dehydration while concentrating flavor and fixing color. Simultaneously, the final stage utilizes high-temperature instantaneous sterilization to ensure product safety and maintain a good taste. In step S1, 0.2-0.3% by weight of polyphosphate is added to the chopping pot to adjust the pH of the system to 7.0-7.5. This chelates divalent cations (Ca... 2+ Mg 2 + This process reduces protein aggregation and promotes myosin dissolution; it can gently raise the pH of the system from 6.0–6.8 to 7.0–7.5, avoiding the isoelectric point of myosin (pH 5.0–5.5) and improving myosin solubility; it also moves the system away from the isoelectric point of soy protein (pH 4.5–5.0), indirectly improving the solubility of soy protein, improving protein-protein compatibility, and reducing the risk of phase separation of soy protein; phosphorylation modification can destroy the globular structure and improve solubility.

[0019] (3) The integrated production line for the preparation process of salmon and cod skin protein products provided by the present invention is fully automated. From extrusion molding to packaging, the entire process is mechanized and automated, effectively avoiding the inconsistencies in specifications and hygiene problems caused by manual operation.

[0020] (4) Preparation process of protein products from salmon and cod skin: The protein products from salmon and cod skin have a clear layered structure. The salmon meat paste layer has a uniform texture and no grainy feel. The moisture content is 55-65%, the slice thickness is 1.5-3.0 mm, and the microbial indicators meet the GB10136 food safety standard. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. It should be noted that, without conflict, the embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0022] Example 1 This embodiment provides a preparation process for animal protein products with improved texture uniformity, including the following steps: S1. Place the salmon paste in a chopping bowl, keep the chopping bowl temperature at 5℃, mix and chop with 60% of the recipe amount of ice water, chop at 1200rpm for 3 minutes to form a continuous protein phase and obtain a fine salmon paste base. S2. After premixing the tapioca starch with 30% of the formula amount of ice water to form a suspension, add it to the fine salmon meat base and chop it at 800 rpm for 3 minutes to fill the continuous phase of the egg white with tapioca starch and obtain the starch-filled phase. S3. After premixing the soy protein with the remaining 10% of the formula amount of ice water, add it to the mixture in step S2 and chop it at 500 rpm for 1 minute to obtain a uniform salmon paste.

[0023] After step S3, step S4 is also included: after the uniform salmon meat paste is extruded into shape, it is quick-frozen at -35°C to obtain frozen salmon meat paste blocks; the quick-freezing equipment adopts fluidized bed quick-freezing, freezing at -35°C to -45°C until the core temperature reaches -18°C, and the freezing time is 30 minutes. S5. Precisely slice the frozen salmon meat paste blocks and dry them to complete the dehydration, color fixation and sterilization. S6. Perform final aseptic packaging in a clean environment to obtain salmon protein products with improved texture uniformity.

[0024] In this embodiment, the soybean protein was soaked in cold water at a ratio of 1:4 for 45 minutes before being premixed with ice water; the cassava starch was pregelatinized at 70°C for 15 minutes before being premixed with ice water.

[0025] This embodiment also provides a process for preparing protein products from salmon and cod skin. After descaling, cleaning, and softening, the cod skin is laid flat on the bottom of a food-grade mold with a thickness of 0.8–1.5 mm. A process for preparing animal protein products with improved texture uniformity yields uniformly textured salmon paste, which is extruded and then spread onto the flatly laid cod skin, forming a layered structure. The uniformly textured salmon paste has a coverage thickness of 3–6 mm. The salmon and cod skin protein products prepared in this embodiment have a clear layered structure. The salmon paste layer has a uniform texture, no graininess, a moisture content of 55–65%, and a slice thickness of 1.5–3.0 mm. Microbiological indicators meet the GB10136 food safety standard.

[0026] This embodiment also provides an integrated production line for the preparation of protein products from salmon and cod skin, including: a low-temperature chopper, a high-speed emulsifying tank, an automatic extrusion molding machine, a cod skin laying robotic arm, a quick-freezing tunnel below -35℃, a high-precision freezing slicer, and a three-stage temperature-controlled intelligent drying room. Each unit is controlled in conjunction with a central PLC system.

[0027] Example 2 This embodiment provides a preparation process for animal protein products with improved texture uniformity, including the following steps: S1. Place the chicken paste in a chopping pot, keep the chopping pot temperature at 5℃, mix and chop with 70% of the recipe amount of ice water at 1200rpm for 5 minutes to form a continuous protein phase and obtain a fine chicken paste base. S2. After premixing the tapioca starch with 20% of the formula amount of ice water to form a suspension, add it to the fine chicken mince base and chop it at 800 rpm for 2 minutes to fill the continuous phase of the egg white with tapioca starch and obtain the starch-filled phase. S3. After premixing the soy protein with the remaining 10% of the formula amount of ice water, add it to the mixture in step S2 and chop it at 500 rpm for 2 minutes to obtain a uniform meat paste.

[0028] In this embodiment, after step S3, step S4 is also included: after the uniform meat paste is extruded into shape, it is quick-frozen at -35°C or below to obtain frozen chicken meat paste blocks; the quick-freezing equipment adopts fluidized bed or spiral quick-freezing, and freezes at -35°C to -45°C until the core temperature reaches -18°C, and the freezing time is 20 minutes. S5. The frozen minced chicken pieces are precisely sliced ​​and dried to complete dehydration, color fixation and sterilization. S6. Perform final aseptic packaging in a clean environment to obtain chicken protein products with improved texture uniformity.

[0029] In this embodiment, the soybean protein was soaked in cold water at a ratio of 1:6 for 30 minutes before being premixed with ice water; the cassava starch was pregelatinized at 65°C for 10 minutes before being premixed with ice water.

[0030] Example 3 This embodiment provides a preparation process for animal protein products with improved texture uniformity, including the following steps: S1. Place the salmon paste in a chopping bowl, keep the chopping bowl temperature at 5℃, mix and chop with 60% of the recipe amount of ice water, chop at 1200rpm for 3 minutes to form a continuous protein phase and obtain a fine salmon paste base. S2. The fat-soluble functional ingredients vitamin E and rosemary extract are emulsified with ice water at high speed to form a stable emulsion, which is then added to the fine minced meat base and chopped. The high-speed emulsification is carried out at 8000 rpm for 2 minutes, and the emulsification temperature is controlled at 10℃. S3. After premixing the tapioca starch with 20% of the formula amount of ice water to form a suspension, add it to the fine salmon meat base and chop it at 800 rpm for 3 minutes to fill the continuous phase of the egg white with tapioca starch and obtain the starch-filled phase. S4. After premixing the soy protein with the remaining 10% of the formula amount of ice water, add it to the mixture in step S2 and chop it at 500 rpm for 1 minute to obtain a uniform salmon paste.

[0031] After step S4, step S5 is also included: after the uniform salmon meat paste is extruded into shape, it is quick-frozen at -35°C or below to obtain frozen salmon meat paste blocks; the quick-freezing equipment adopts fluidized bed quick-freezing, freezing at -35°C to -45°C until the core temperature reaches -18°C, and the freezing time is 30 minutes. S6. The frozen salmon meat paste is precisely sliced ​​and dried to complete dehydration, color fixation and sterilization. In step S5, the drying process adopts a three-stage drying process, which is to process at 50℃, 65℃ and 80℃ in sequence.

[0032] S7. Perform final aseptic packaging in a clean environment to obtain salmon protein products with improved texture uniformity.

[0033] In this embodiment, the soybean protein was soaked in cold water at a ratio of 1:4 for 45 minutes before being premixed with ice water; the cassava starch was pregelatinized at 70°C for 15 minutes before being premixed with ice water.

[0034] Example 4 This embodiment provides a preparation process for animal protein products with improved texture uniformity, including the following steps: S1. Place the salmon paste in a chopping pot, maintain the temperature of the chopping pot at 5℃, and mix it with 60% of the formula amount of ice water. Also add 0.2% by weight of polyphosphate to the chopping pot, adjust the pH of the system to 7.0, and chop at 1200rpm for 3 minutes to form a continuous protein phase and obtain a fine salmon paste base. S2. The fat-soluble functional ingredients vitamin E and rosemary extract are emulsified with ice water at high speed to form a stable emulsion, which is then added to the fine salmon paste base and chopped. High-speed emulsification is carried out at 12,000 rpm for 5 minutes, and the emulsification temperature is controlled at 10℃. S3. After premixing the tapioca starch with 20% of the formula amount of ice water to form a suspension, add it to the fine salmon meat base and chop it at 800 rpm for 3 minutes to fill the continuous phase of the egg white with tapioca starch and obtain the starch-filled phase. S4. After premixing the soy protein with the remaining 10% of the formula amount of ice water, add it to the mixture in step S2 and chop it at 500 rpm for 1 minute to obtain a uniform salmon paste.

[0035] After step S4, step S5 is also included: after the uniform salmon meat paste is extruded into shape, it is quick-frozen at -35°C or below to obtain frozen salmon meat paste blocks; the quick-freezing equipment adopts spiral quick-freezing, freezing at -35°C to -45°C until the core temperature reaches -18°C, and the freezing time is 30 minutes. S6. The frozen salmon meat paste is precisely sliced ​​and then dried to complete the dehydration, color fixation and sterilization. The drying process adopts a three-stage drying process, which is carried out at 60℃, 65℃ and 90℃ in sequence.

[0036] S7. Perform final aseptic packaging in a clean environment to obtain salmon protein products with improved texture uniformity.

[0037] In this embodiment, the soybean protein was soaked in cold water at a ratio of 1:4 for 45 minutes before being premixed with ice water; the cassava starch was pregelatinized at 70°C for 15 minutes before being premixed with ice water.

[0038] Comparative Example 1 Unlike Example 1, Comparative Example 1 uses a conventional process: one-time feeding + room temperature chopping (15°C) + slow freezing at -18°C + single-stage drying (70°C, 6h) to simulate existing technology.

[0039] This comparative example provides a preparation process for animal protein products with improved texture uniformity, comprising the following steps: S1. Place the salmon paste in a chopping pot, keep the chopping pot temperature at 15℃, then add tapioca starch and soy protein, add water and mix and chop at 1200rpm for 3 minutes to obtain salmon paste.

[0040] After step S1, step S2 is also included: after the uniform salmon meat paste is extruded into shape, it is quick-frozen at -35°C to obtain frozen salmon meat paste blocks; the quick-freezing equipment adopts fluidized bed quick-freezing, starting from room temperature 15°C and slowly freezing to the core temperature -18°C, with a freezing time of 30 minutes. S5. Precisely slice the frozen salmon meat paste blocks and dry them at 70℃ in a single stage to complete dehydration, color fixation and sterilization. S6. Perform final aseptic packaging in a clean environment to obtain salmon protein products with improved texture uniformity.

[0041] Experimental Example Test metrics Texture uniformity: Hardness, elasticity, and chewiness are measured using a texture analyzer; cross-sectional structure is observed under a microscope; Protein extraction rate: Salt-soluble protein content (%); Flavor retention: Headspace solid-phase microextraction-gas chromatography (HS-SPME-GC) was used to determine the retention of key volatile flavor compounds (such as hexanal and nonanal); Oxidative stability: Peroxide value (POV, g / 100g), TBARS value (malondialdehyde mg / kg); Microbiological safety: Total bacterial count (CFU / g) shall be tested in accordance with the method of GB / T13093; Sensory evaluation: blind review by a panel of 10 people (texture, flavor, color, out of 10).

[0042] To verify the effectiveness of the present invention, Comparative Example 1 (traditional one-time feeding, room temperature chopping, -18℃ freezing, and single-stage drying at 70℃) was set up for comparison with Examples 1 and 3. The results are shown in Table 1 below.

[0043] Table 1

[0044] As can be seen from Table 1, the texture is significantly improved: the hardness of Examples 1 and 3 is reduced by more than 30%, and the elasticity is increased by 60%, indicating that the protein continuous phase network is more dense and uniform; microscopic observation confirms that there is no starch particle precipitation or protein aggregation, solving the problems of "slagging and stratification" in traditional processes.

[0045] Improved protein extraction rate: Low-temperature chopping in Examples 1 and 3 moved myosin away from its isoelectric point, increasing the extraction rate by about 25%, which laid the foundation for gel strength.

[0046] Flavor and nutrition are highly preserved: In Example 3, the retention rate of hexanal (the key flavor compound of fish) reached 86.7%, which is much higher than the traditional 58.2%; POV and TBARS values ​​were reduced by 60% and 65% respectively, proving that lipid oxidation was effectively inhibited. This is attributed to: low-temperature processing to reduce heat-induced oxidation; and the uniform dispersion of vitamin E and rosemary extract after emulsification, which exerted a synergistic antioxidant effect.

[0047] Balancing safety and taste: In Examples 1 and 3, the final stage of the three-stage drying process involves instantaneous sterilization at 80°C for 1.5 hours, achieving commercial sterility (<1×10⁻⁶). 4 (CFU / g); at the same time, due to the mild dehydration in the early stage, the product does not harden or lose water excessively, and the sensory score of Example 3 reached 9.3 points.

[0048] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A preparation process for animal protein products with improved texture uniformity, characterized in that, Includes the following steps: S1. Place the animal meat paste in a chopping pot, keep the temperature of the chopping pot ≤5℃, and mix it with 60%-70% of the formula amount of ice water. Chop at 1200rpm for 3-5 minutes to form a continuous protein phase and obtain a fine meat paste base. S2. After premixing cassava starch with 20%-30% of the formula amount of ice water to form a suspension, add it to the fine minced meat base and chop it at 800 rpm for 2-3 minutes to fill the protein continuous phase with cassava starch and obtain the starch-filled phase. S3. After premixing the soy protein with the remaining amount of ice water, add it to the mixture from step S2 and chop at 500 rpm for 1-2 minutes to obtain a uniform meat paste.

2. The preparation process of an animal protein product with improved texture uniformity as described in claim 1, characterized in that, After step S3, step S4 is also included: after the uniformly textured minced meat is extruded and shaped, it is quick-frozen at -35°C or below to obtain frozen minced meat blocks; the quick-freezing equipment adopts fluidized bed or spiral quick-freezing, and freezes at -35°C to -45°C until the core temperature is ≤-18°C, and the freezing time is ≤30 minutes. S5. The frozen minced meat blocks are precisely sliced ​​and dried to complete dehydration, color fixation, and sterilization. S6. Perform final aseptic packaging in a clean environment to obtain the animal protein product with improved texture uniformity.

3. The preparation process of an animal protein product with improved texture uniformity as described in claim 1, characterized in that, In step S1, the animal meat paste is either salmon paste or chicken paste.

4. The preparation process of an animal protein product with improved texture uniformity as described in claim 2, characterized in that, In step S5, the drying process employs a three-stage drying process, specifically, the drying is carried out sequentially at 50-60℃, 60-65℃, and 80-90℃.

5. The preparation process of an animal protein product with improved texture uniformity as described in claim 1, characterized in that, Before being premixed with ice water, the soybean protein is soaked in cold water at a ratio of 1:4-6 for 30-45 minutes; before being premixed with ice water, the cassava starch is pregelatinized at 65-70℃ for 10-15 minutes.

6. The preparation process of an animal protein product with improved texture uniformity as described in claim 1, characterized in that, In step S1, 0.2-0.3% by mass of polyphosphate is added to the chopping pot to adjust the pH of the system to 7.0-7.

5.

7. The preparation process of an animal protein product with improved texture uniformity as described in claim 1, characterized in that, Between step S1 and step S2, the process further includes: emulsifying the fat-soluble functional ingredients with ice water at high speed to form a stable emulsion, which is then added to the fine minced meat base for chopping; the high-speed emulsification is carried out at 8000–12000 rpm for 2–5 minutes, and the emulsification temperature is controlled at ≤10℃; the fat-soluble functional ingredients include vitamin E and rosemary extract.

8. A process for preparing protein products from salmon and cod skin, characterized in that, After being descaled, cleaned, and softened, cod skin is laid flat on the bottom of a food-grade mold with a thickness of 0.8–1.5 mm. The salmon paste with uniform texture obtained by the preparation process of an animal protein product with improved texture uniformity as described in any one of claims 1–7 is extruded and then laid on the flat cod skin to form a layered structure, wherein the covering thickness of the salmon paste with uniform texture is 3–6 mm.

9. An integrated production line implementing the protein product preparation process of salmon and cod skin as described in claim 8, characterized in that, include: The system includes a low-temperature chopper, a high-speed emulsifying tank, an automatic extrusion molding machine, a cod skin laying robotic arm, a quick-freezing tunnel below -35℃, a high-precision freezing slicer, and a three-section temperature-controlled intelligent drying room. All units are linked and controlled by a central PLC system.

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