Preparation method of skin jelly capable of prolonging shelf life through compound technology

Abstract

The invention discloses a skin jelly preparation method capable of prolonging the shelf life through a compound technology, and relates to the technical field of food processing technologies. The method comprises the following steps: cutting an animal skin raw material, treating with a sodium carbonate solution, cleaning with a citric acid solution, boiling to extract a collagen solution, adding ascorbic acid and nisin, freezing and forming, drying in vacuum, performing irradiation sterilization and the like. According to the method, fat and impurities in the raw materials can be effectively removed, oxidation reaction and microbial reproduction can be inhibited, the moisture content can be reduced to 5% or below, and residual microorganisms can be thoroughly killed, so that the shelf life of the skin jelly can be remarkably prolonged to 12 months or above, meanwhile, good taste and nutritional value are kept, market requirements are met, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a method for preparing aspic that extends shelf life through a composite process. Background Technology

[0002] With the continuous development of food processing technology, extending the shelf life of food has become an important means to enhance the market competitiveness of products. As a traditional food, aspic is loved by consumers for its unique taste and nutritional value, but it is susceptible to microbial contamination and oxidation during storage, resulting in a short shelf life, which limits its market promotion and industrial production.

[0003] Patent CN108917832B discloses an integrated online food processing and testing device. This patent relates to a food processing apparatus that integrates filling, mixing, testing, and sealing, achieving hygiene control and quality testing during food processing through devices such as a sterilization robotic arm. However, this technical solution primarily focuses on automation and hygiene assurance during processing, without addressing improvements in the food's formula optimization or subsequent storage stability. Therefore, it struggles to effectively address the potential microbial growth and oxidation issues that may arise during long-term storage of aspic. Furthermore, the equipment's high complexity increases production costs, making it less suitable for small and medium-sized production enterprises.

[0004] In existing technologies, a food processing separation device reduces the amount of chicken feet meat removed through oblique cutting, while utilizing structures such as guide frames and oscillating plates to achieve precise positioning and efficient separation. Although this technical solution represents a breakthrough in food processing efficiency and precision, it targets the separation of specific food raw materials and does not address processes related to extending food shelf life. For foods like aspic, which are primarily composed of collagen, this solution lacks specificity and fails to address the issue of aspic's susceptibility to external environmental influences during storage. The aforementioned existing technologies indicate that in the field of aspic preparation, current processing equipment and technical solutions focus more on automation and efficiency improvement, while research on the synergistic effects of composite processes, formula optimization, and storage stability remains insufficient. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing aspic that extends shelf life through a composite process, in order to solve the problems of short shelf life and easy spoilage caused by incomplete removal of impurities, insufficient microbial control, and excessive moisture content in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing aspic that extends shelf life through a composite process includes the following steps: Step S10: Cut the animal hide raw material into strips with a thickness of 2 mm to 5 mm and a length of 3 cm to 8 cm, and soak them in a sodium carbonate solution with a mass fraction of 0.5% to 1.5% at 60 degrees Celsius to 70 degrees Celsius for 3 to 5 hours to remove surface impurities and some fat components. Step S20: Place the strip-shaped material treated in S10 into a citric acid solution with a mass fraction of 2% to 4%, and stir and wash it at a temperature of 50 degrees Celsius to 60 degrees Celsius for 1 to 2 hours, and then rinse it with deionized water until neutral. Step S30: Add the washed strips to water with a mass ratio of 1:3 to 1:5 and boil for 2 to 3 hours. Then filter to obtain collagen liquid. Step S40: Add 0.05% to 0.15% by mass of ascorbic acid and 0.02% to 0.05% by mass of nisin to the collagen solution, stir evenly, and then cool to 40°C to 50°C. Step S50: Inject the cooled collagen liquid into the mold and freeze it at a temperature of -18 degrees Celsius to -25 degrees Celsius for 4 to 6 hours; Step S60: After the frozen aspic is taken out, it is placed in a vacuum drying device and vacuum dried for 2 to 3 hours at a pressure of 10 Pa to 50 Pa and a temperature of 30 degrees Celsius to 40 degrees Celsius. Step S70: Package the vacuum-dried aspic and subject it to irradiation sterilization treatment with an irradiation dose of 4 to 6 kGy.

[0007] According to this invention, treatment with sodium carbonate solution removes fat and impurities from animal skin raw materials, and washing with citric acid solution further improves the purity of the raw materials, reducing the possibility of microbial growth. Collagen extract is obtained during boiling, and the addition of ascorbic acid and nisin inhibits oxidation and microbial reproduction, thereby improving the storage stability of the aspic. The combination of freeze-forming and vacuum drying reduces the internal moisture content of the aspic to below 5%, further inhibiting microbial activity. Irradiation sterilization completely kills residual microorganisms, ensuring the aspic maintains high quality during long-term storage.

[0008] In step S10, the sodium carbonate solution has a mass fraction of 0.8% to 1.2%, and the treatment time is 3.5 to 4.5 hours. Under these conditions, the sodium carbonate solution can more effectively remove fat and impurities from the surface of animal skin, while avoiding damage to the collagen structure.

[0009] In step S20, the citric acid solution has a mass fraction of 2.5% to 3.5%, and the stirring and washing time is 1.2 hours to 1.8 hours. The use of citric acid solution not only neutralizes sodium carbonate residue but also further cleans the surface of the raw materials, improving the purity of the subsequent collagen solution.

[0010] In step S40, the mass fraction of ascorbic acid is 0.08% to 0.12%, and the mass fraction of nisin is 0.03% to 0.04%. Ascorbic acid, as an antioxidant, can effectively inhibit the oxidation reaction in collagen solution, while nisin further enhances the microbial stability of the jelly by inhibiting the growth of Gram-positive bacteria.

[0011] In step S50, the freezing temperature is -20°C to -22°C, and the freezing time is 4.5 hours to 5.5 hours. Under these conditions, the collagen liquid can quickly form a stable solid structure, avoiding ice crystal damage caused by slow freezing.

[0012] In step S60, the vacuum drying pressure is 20 Pa to 40 Pa, the temperature is 32 degrees Celsius to 38 degrees Celsius, and the drying time is 2.2 hours to 2.8 hours. Optimizing the vacuum drying conditions can ensure that the internal moisture content of the aspic is below 5% while avoiding the loss of nutrients caused by high temperature or excessively long drying time.

[0013] In step S70, the irradiation sterilization dose is between 4.5 kGy and 5.5 kGy. This dose range can thoroughly kill microorganisms while avoiding adverse effects on the sensory quality and nutritional components of the aspic.

[0014] Secondly, the present invention provides a skin jelly product prepared by the above method. Because this skin jelly product is prepared using a composite process, its shelf life is significantly extended to more than 12 months, while maintaining good taste and nutritional value.

[0015] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention optimizes the pretreatment process of animal skin raw materials by using a specific concentration of sodium carbonate and citric acid solution for stepwise cleaning, which effectively removes surface impurities and fat components, while neutralizing residual alkaline substances, significantly improving the purity of collagen solution.

[0016] This invention, by adding ascorbic acid and nisin to collagen solution, synergistically inhibits oxidation and microbial growth, enhances the chemical and microbial stability of the aspic, and thus effectively delays quality deterioration.

[0017] This invention employs a process combining rapid freezing and vacuum drying to reduce the internal moisture content of the aspic to below 5%, avoiding damage from ice crystals and loss of nutrients. Simultaneously, combined with irradiation sterilization, it thoroughly kills microorganisms and significantly extends the product's shelf life.

[0018] This invention, through the integrated application of composite processes, achieves comprehensive control over moisture content, total microbial count, and oxidation level while maintaining the texture and nutritional value of the aspic, thus extending the product's shelf life to more than 12 months. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for preparing aspic that extends shelf life through a composite process, as provided in an embodiment of the present invention. Detailed Implementation

[0020] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present invention and not to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present invention by illustrating examples of the invention.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0022] In the embodiments of the present invention, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of the present invention shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on the present invention; the term "multiple" in the present invention refers to two or more (including two).

[0023] In a first aspect, this application provides a method for preparing aspic that extends shelf life through a composite process, comprising the following steps: Step S10: Cut the animal hide raw material into strips with a thickness of 2 mm to 5 mm and a length of 3 cm to 8 cm, and soak them in a sodium carbonate solution with a mass fraction of 0.5% to 1.5% at 60 degrees Celsius to 70 degrees Celsius for 3 to 5 hours to remove surface impurities and some fat components. Step S20: Place the strip-shaped material treated in step S10 into a citric acid solution with a mass fraction of 2% to 4%, and stir and wash it at a temperature of 50 degrees Celsius to 60 degrees Celsius for 1 to 2 hours, and then rinse it with deionized water until neutral. Step S30: Add the washed strips to water with a mass ratio of 1:3 to 1:5 and boil for 2 to 3 hours. Then filter to obtain collagen liquid. Step S40: Add 0.05% to 0.15% by mass of ascorbic acid and 0.02% to 0.05% by mass of nisin to the collagen solution, stir evenly, and then cool to 40°C to 50°C. Step S50: Inject the cooled collagen liquid into the mold and freeze it at a temperature of -18 degrees Celsius to -25 degrees Celsius for 4 to 6 hours; Step S60: After the frozen aspic is taken out, it is placed in a vacuum drying device and vacuum dried for 2 to 3 hours at a pressure of 10 Pa to 50 Pa and a temperature of 30 degrees Celsius to 40 degrees Celsius. Step S70: Package the vacuum-dried aspic and subject it to irradiation sterilization treatment with an irradiation dose of 4 to 6 kGy.

[0024] In step S10, the animal hide raw material is cut into strips with a thickness of 2 mm to 5 mm and a length of 3 cm to 8 cm. This is to facilitate sufficient contact with the solution during subsequent processing and improve processing efficiency. The strips are soaked in a sodium carbonate solution with a mass fraction of 0.5% to 1.5% for 3 to 5 hours, which effectively removes surface impurities and some fat components. The preferred mass fraction of the sodium carbonate solution is 0.8% to 1.2%, and the preferred processing time is 3.5 to 4.5 hours. Under these conditions, the sodium carbonate solution can more effectively remove fat and impurities from the surface of the animal hide while avoiding damage to the collagen structure.

[0025] In step S20, the strip-shaped material treated in S10 is placed in a citric acid solution with a mass fraction of 2% to 4%, and stirred and washed at a temperature of 50°C to 60°C for 1 to 2 hours, followed by rinsing with deionized water until neutral. The preferred mass fraction of the citric acid solution is 2.5% to 3.5%, and the preferred stirring and washing time is 1.2 to 1.8 hours. The use of citric acid solution not only neutralizes sodium carbonate residue but also further cleans the surface of the raw material, improving the purity of the subsequent collagen solution.

[0026] In step S30, the washed strips are added to water at a mass ratio of 1:3 to 1:5 and boiled for 2 to 3 hours, then filtered to obtain a collagen solution. The purpose of boiling in this step is to extract collagen from the animal skin while removing insoluble impurities. The preferred mass ratio is 1:4, and the preferred boiling time is 2.5 hours. Under these conditions, a high concentration of collagen solution can be obtained while avoiding nutrient loss due to over-boiling.

[0027] In step S40, ascorbic acid at a mass fraction of 0.05% to 0.15% and nisin at a mass fraction of 0.02% to 0.05% are added to the collagen solution, stirred evenly, and then cooled to 40°C to 50°C. The preferred mass fraction of ascorbic acid is 0.08% to 0.12%, and the preferred mass fraction of nisin is 0.03% to 0.04%. The addition of ascorbic acid inhibits the oxidation reaction in the collagen solution, while nisin further enhances the microbial stability of the gelatin by inhibiting the growth of Gram-positive bacteria.

[0028] In step S50, the cooled collagen liquid is injected into a mold and frozen at a temperature of -18°C to -25°C for 4 to 6 hours. The preferred freezing temperature is -20°C to -22°C, and the preferred freezing time is 4.5 to 5.5 hours. Under these conditions, the collagen liquid can quickly form a stable solid structure, avoiding damage from ice crystals caused by slow freezing.

[0029] In step S60, the frozen aspic is removed and placed in a vacuum drying device for vacuum drying at a pressure of 10 Pa to 50 Pa and a temperature of 30°C to 40°C for 2 to 3 hours. The preferred vacuum drying pressure is 20 Pa to 40 Pa, the preferred temperature is 32°C to 38°C, and the preferred drying time is 2.2 to 2.8 hours. Optimizing the vacuum drying conditions ensures that the internal moisture content of the aspic is below 5% while avoiding nutrient loss due to high temperature or prolonged drying.

[0030] In step S70, the vacuum-dried aspic is packaged and subjected to irradiation sterilization at a dose of 4,000 to 6,000 Gy. The preferred irradiation dose is 4.5,000 to 5.5,000 Gy. Within this dose range, microorganisms can be completely killed while avoiding adverse effects on the sensory quality and nutritional components of the aspic.

[0031] The technical solution of this application will be described in detail below with reference to specific embodiments.

[0032] Example 1: Pigskin was cut into strips 3 mm thick and 5 cm long, and soaked in a 1% sodium carbonate solution at 65°C for 4 hours. The strips were then placed in a 3% citric acid solution and washed at 55°C with stirring for 1.5 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a 1:4 ratio and boiled for 2.5 hours, then filtered to obtain a collagen solution. 0.1% ascorbic acid and 0.03% nisin were added to the collagen solution, stirred thoroughly, and cooled to 45°C. The cooled collagen solution was poured into molds and frozen at -20°C for 5 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 35°C and 30 Pa for 2.5 hours. Finally, the vacuum-dried aspic was packaged and subjected to irradiation sterilization at a dose of 5 kGy.

[0033] Example 2: The cowhide was cut into strips 4 mm thick and 6 cm long, and soaked in a 1.2% sodium carbonate solution at 68°C for 4.5 hours. The strips were then placed in a 3.5% citric acid solution and washed at 58°C with stirring for 1.8 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a ratio of 1:4.5 and boiled for 2.8 hours, then filtered to obtain a collagen solution. 0.12% ascorbic acid and 0.04% nisin were added to the collagen solution, stirred thoroughly, and then cooled to 48°C. The cooled collagen solution was poured into molds and frozen at -22°C for 5.5 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 37°C and 35 Pa for 2.8 hours. Finally, the vacuum-dried aspic is packaged and subjected to irradiation sterilization at a dose of 5.5 kGy.

[0034] Example 3: Sheepskin was cut into strips 2.5 mm thick and 4 cm long, and soaked in a 0.8% sodium carbonate solution at 62°C for 3.5 hours. The strips were then placed in a 2.5% citric acid solution and washed at 52°C with stirring for 1.3 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a ratio of 1:3.5 and boiled for 2.3 hours, then filtered to obtain a collagen solution. 0.08% ascorbic acid and 0.035% nisin were added to the collagen solution, stirred thoroughly, and then cooled to 42°C. The cooled collagen solution was poured into molds and frozen at -21°C for 5 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 33°C and a pressure of 25 Pa for 2.3 hours. Finally, the vacuum-dried aspic was packaged and subjected to irradiation sterilization treatment with an irradiation dose of 4.8 kGy.

[0035] Example 4: Chicken skin was cut into strips 3.5 mm thick and 7 cm long, and soaked in a 1.5% sodium carbonate solution at 67°C for 5 hours. The strips were then placed in a 4% citric acid solution and washed at 60°C with stirring for 2 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a 1:5 ratio and boiled for 3 hours, after which the solution was filtered to obtain collagen. 0.15% ascorbic acid and 0.05% nisin were added to the collagen solution, stirred thoroughly, and then cooled to 50°C. The cooled collagen solution was poured into molds and frozen at -23°C for 6 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 38°C and a pressure of 40 Pa for 3 hours. Finally, the vacuum-dried aspic was packaged and subjected to irradiation sterilization at a dose of 6 kGy.

[0036] Comparative Example 1: Pigskin was cut into strips 3 mm thick and 5 cm long, and soaked in water at 65°C for 4 hours. The strips were then placed in a 3% citric acid solution and washed at 55°C with stirring for 1.5 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a 1:4 ratio and boiled for 2.5 hours, then filtered to obtain a collagen solution. 0.1% ascorbic acid and 0.03% nisin were added to the collagen solution, stirred thoroughly, and cooled to 45°C. The cooled collagen solution was poured into molds and frozen at -20°C for 5 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 30 Pa and 35°C for 2.5 hours. Finally, the vacuum-dried aspic was packaged and subjected to irradiation sterilization at a dose of 5 kGy.

[0037] Comparative Example 2: The cowhide was cut into strips 4 mm thick and 6 cm long, and soaked in a 1.2% sodium carbonate solution at 68°C for 4.5 hours. The strips were then placed in clean water and washed at 58°C with stirring for 1.8 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a ratio of 1:4.5 and boiled for 2.8 hours, then filtered to obtain a collagen solution. 0.12% ascorbic acid and 0.04% nisin were added to the collagen solution, stirred thoroughly, and then cooled to 48°C. The cooled collagen solution was poured into molds and frozen at -22°C for 5.5 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 35 Pa and 37°C for 2.8 hours. Finally, the vacuum-dried aspic is packaged and subjected to irradiation sterilization at a dose of 5.5 kGy.

[0038] Comparative Example 3: Sheepskin was cut into strips 2.5 mm thick and 4 cm long, and soaked in a 0.8% sodium carbonate solution at 62°C for 3.5 hours. The strips were then placed in a 2.5% citric acid solution and washed at 52°C with stirring for 1.3 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a ratio of 1:3.5 and boiled for 2.3 hours, followed by filtration to obtain a collagen solution. No ascorbic acid or nisin was added to the collagen solution. After thorough stirring, the solution was cooled to 42°C. The cooled collagen solution was poured into molds and frozen at -21°C for 5 hours. The frozen aspic was then placed in a vacuum drying apparatus and vacuum dried at 33°C and a pressure of 25 Pa for 2.3 hours. Finally, the vacuum-dried aspic was packaged and subjected to irradiation sterilization at a dose of 4.8 kGy.

[0039] Comparative Example 4: Chicken skin was cut into strips 3.5 mm thick and 7 cm long, and soaked in a 1.5% sodium carbonate solution at 67°C for 5 hours. The strips were then placed in a 4% citric acid solution and washed at 60°C with stirring for 2 hours, followed by rinsing with deionized water until neutral. The washed strips were then added to water at a 1:5 ratio and boiled for 3 hours, after which the solution was filtered to obtain a collagen liquid. 0.15% ascorbic acid and 0.05% nisin were added to the collagen liquid, stirred thoroughly, and then cooled to 50°C. The cooled collagen liquid was poured into molds and frozen at -23°C for 6 hours. The frozen aspic was directly packaged without vacuum drying or irradiation sterilization.

[0040] The experimental data are shown in the table below: project Moisture content (%) Total microbial count (CFU / g) Degree of oxidation (absorbance value) Shelf life (months) Example 1 4.2 <10 0.12 12 Example 2 4.5 <10 0.13 12 Example 3 4 <10 0.11 13 Example 4 4.8 <10 0.14 12 Comparative Example 1 5.2 200 0.25 8 Comparative Example 2 5.5 300 0.28 7 Comparative Example 3 6 500 0.3 6 Comparative Example 4 8.5 1000 0.4 4 According to the experimental data, the aspic prepared in this application is superior to the comparative examples in terms of moisture content, total microbial count, oxidation level, and shelf life. Comparative Examples 1 and 2 did not use sodium carbonate or citric acid solution treatment, resulting in a significant increase in the total microbial count and a shortened shelf life. Comparative Example 3 did not add ascorbic acid and nisin, leading to an increased oxidation level and a higher total microbial count. Comparative Example 4 did not undergo vacuum drying and irradiation sterilization, resulting in excessively high moisture content, a significant increase in the total microbial count, and a significantly shortened shelf life.

[0041] In summary, the method for preparing aspic that extends shelf life through a composite process provided in this application can effectively extend the shelf life of aspic while maintaining good taste and nutritional value.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing aspic with extended shelf life through a composite process, characterized in that, Includes the following steps: step S10: Cut animal hide raw materials into strips with a thickness of 2 mm to 5 mm and a length of 3 cm to 8 cm, and immerse them in a sodium carbonate solution with a mass fraction of 0.5% to 1.5% at 60 degrees Celsius to 70 degrees Celsius for 3 to 5 hours; Step S20: Place the strip-shaped material treated in S10 into a citric acid solution with a mass fraction of 2% to 4%, and stir and wash it at a temperature of 50 degrees Celsius to 60 degrees Celsius for 1 to 2 hours, and then rinse it with deionized water until neutral. Step S30: Add the washed strips to water with a mass ratio of 1:3 to 1:5 and boil for 2 to 3 hours. Then filter to obtain collagen liquid. Step S40: Add 0.05% to 0.15% by mass of ascorbic acid and 0.02% to 0.05% by mass of nisin to the collagen solution, stir evenly, and then cool to 40°C to 50°C. Step S50: Inject the cooled collagen liquid into the mold and freeze it at a temperature of -18 degrees Celsius to -25 degrees Celsius for 4 to 6 hours; Step S60: After the frozen aspic is taken out, it is placed in a vacuum drying device and vacuum dried for 2 to 3 hours at a pressure of 10 Pa to 50 Pa and a temperature of 30 degrees Celsius to 40 degrees Celsius. Step S70: Package the vacuum-dried aspic and subject it to irradiation sterilization treatment with an irradiation dose of 4 to 6 kGy.

2. The method according to claim 1, characterized in that, In step S10, the mass fraction of the sodium carbonate solution is 0.8% to 1.2%, and the processing time is 3.5 hours to 4.5 hours.

3. The method according to claim 1, characterized in that, In step S20, the citric acid solution has a mass fraction of 2.5% to 3.5%, and the stirring and washing time is 1.2 hours to 1.8 hours.

4. The method according to claim 1, characterized in that, In step S40, the mass fraction of ascorbic acid is 0.08% to 0.12%, and the mass fraction of nisin is 0.03% to 0.04%.

5. The method according to claim 1, characterized in that, In step S50, the freezing temperature is -20 degrees Celsius to -22 degrees Celsius, and the freezing time is 4.5 hours to 5.5 hours.

6. The method according to claim 1, characterized in that, In step S60, the vacuum drying pressure is 20 Pa to 40 Pa, the temperature is 32 degrees Celsius to 38 degrees Celsius, and the drying time is 2.2 hours to 2.8 hours.

7. The method according to claim 1, characterized in that, In step S70, the irradiation sterilization dose is 4.5 kGy to 5.5 kGy.

8. The method according to claim 1, characterized in that, The animal hide material is selected from one or more of pigskin, cowhide, sheepskin, or chicken skin.

9. The method according to claim 1, characterized in that, In step S30, the boiling state is maintained for 2.5 to 3 hours.

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