A meat product preservative film and a method of preparing the same

Abstract

The application belongs to the technical field of meat product preservation, and discloses a meat product preservation film and a preparation method thereof. A base film is obtained by electrospinning of a composite material of chitosan and polylactic acid, then a sodium alginate solution of a natural antibacterial agent is coated on the upper and lower surfaces of the base film, and the antibacterial layer is firmly combined with the base film through crosslinking of calcium chloride. The preservation film of the application combines the base film with the antibacterial layer, and forms a dense network structure on the surface of the base film through crosslinking, which can significantly improve the oxygen barrier property, and the mechanical property of the preservation film can also be improved. The application also adds a moisture absorbent in the base film, which can remove the water vapor generated during the storage of the meat product, and the chitosan in the base film and the natural antibacterial agent in the antibacterial layer make the base film and the antibacterial layer both have good antibacterial property, combined with high oxygen barrier property, which can significantly prolong the shelf life of the meat product.

Description

Technical Field

[0001] This invention relates to the field of meat product preservation technology, and in particular to a meat product preservation film and its preparation method. Background Technology

[0002] Meat is an essential ingredient in daily life, and preservation is an indispensable step in the process of fresh meat from slaughter to secondary processing or sale. Preservation can prevent bacterial growth, ensure food safety, extend shelf life, and improve the appearance of meat products. As people's living standards improve, higher requirements are being placed on the preservation of meat.

[0003] Currently, traditional methods for preserving meat include freezing, refrigeration, and specialized preservation materials. Among these, specialized preservation materials are widely used due to their convenience, practicality, and low cost. Existing specialized preservation materials include preservatives and plastic wrap. For example, patent 202010460122.4 discloses an antibacterial and preservative-preserving film for meat, which has a five-layer structure: a first polyethylene layer, a first vinyl acetate copolymer layer, a polyvinylidene chloride layer, a second vinyl acetate copolymer layer, and a second polyethylene layer. The first polyethylene layer includes nano-silver polyethylene antibacterial masterbatch, which can effectively improve antibacterial and preservative properties. This type of plastic wrap is polymerized using ethylene as a masterbatch. Polyethylene plastic wrap is a common type on the market; however, polyethylene has poor biodegradability, easily causing white pollution, and the added plasticizers and other functional additives have poor safety. Furthermore, the nano-silver antibacterial agent used in this technology is costly and easily detaches from the film, becoming ineffective. Regarding the issues of food preservation film materials and antibacterial agents, patent 201611105239.0 discloses a method of mixing chitosan solution and starch solution in a certain proportion, adding a certain volume of glycerol, drying to form a film, and then covalently crosslinking the carboxyl groups of antimicrobial peptide molecules with the amino groups of chitosan molecules on the film using a crosslinking agent to obtain a biodegradable antimicrobial food preservation film. This food preservation film combines the excellent antimicrobial properties of antimicrobial peptides and chitosan, but its mechanical properties are poor, its flexibility is low, and its oxygen barrier properties are poor, which cannot meet the needs of food preservation applications in various scenarios.

[0004] Therefore, how to provide a biodegradable and low-cost meat preservation film that balances antibacterial and mechanical properties is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a meat product preservation film and its preparation method, which solves the problems of poor mechanical properties, low flexibility, and poor oxygen barrier properties of existing preservation films.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing a meat product preservation film, comprising the following steps:

[0008] Chitosan, polylactic acid, hygroscopic agent, acetic acid, and water are mixed to obtain a spinning solution;

[0009] The spinning solution was electrospun to obtain the base film;

[0010] An antibacterial agent solution is coated on the upper and lower surfaces of the base film, and then cross-linked in a calcium chloride solution to form an antibacterial layer on the upper and lower surfaces of the base film, thus obtaining the meat product preservation film.

[0011] The antibacterial solution includes an antibacterial agent and sodium alginate.

[0012] Preferably, in the above-mentioned method for preparing a meat product preservation film, the mass ratio of chitosan, polylactic acid, and desiccant is 10-20:15-30:1-6.

[0013] Preferably, in the above-mentioned method for preparing a meat product preservation film, the electrospinning conditions include: a voltage of 10-20 kV; a receiving distance of 15-20 cm; and an injection speed of 0.3-1 mL / h.

[0014] Preferably, in the above-mentioned method for preparing a meat product preservation film, the thickness of the base film is 20-60 μm.

[0015] Preferably, in the above-mentioned method for preparing a meat product preservation film, the antibacterial agent solution has a mass concentration of 5-10% and a sodium alginate mass concentration of 3-10%.

[0016] Preferably, in the above-mentioned method for preparing a meat product preservation film, the coating amount on the upper and lower surfaces is independently 1-5 mL / cm². 2 .

[0017] Preferably, in the above-mentioned method for preparing a meat product preservation film, the antibacterial agent is one or more of tea polyphenols, cinnamaldehyde, and orange peel extract.

[0018] Preferably, in the above-mentioned method for preparing a meat product preservation film, the cross-linking time is 30-120 min; the cross-linking temperature is 25-50°C; and the mass concentration of the calcium chloride solution is 1-10%.

[0019] Preferably, in the above-mentioned method for preparing a meat product preservation film, the thickness of the antibacterial layer on the upper and lower surfaces is independently 5 to 30 μm.

[0020] The present invention also provides a method for preparing a meat product preservation film.

[0021] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention uses a composite material of chitosan and polylactic acid to obtain a base film via electrospinning. Then, a sodium alginate solution containing natural antibacterial agents is coated onto the upper and lower surfaces of the base film. Following cross-linking with calcium chloride, the antibacterial layer is firmly bonded to the base film. The preservation film of this invention, through the composite base film and antibacterial layer, and the cross-linking process, forms a dense network structure on the surface of the base film, significantly improving oxygen barrier properties and enhancing the mechanical properties of the preservation film. This invention also adds a desiccant to the base film to remove moisture generated during meat product storage. Furthermore, the chitosan in the base film and the natural antibacterial agents in the antibacterial layer give both the base film and the antibacterial layer excellent antibacterial properties. Combined with high oxygen barrier properties, this significantly extends the shelf life of meat products. In addition, the raw materials used in this invention are all natural extracts or biodegradable materials, making it green and environmentally friendly. It degrades after a period of use and will not cause white pollution. Detailed Implementation

[0023] This invention provides a method for preparing a meat product preservation film, comprising the following steps:

[0024] Chitosan, polylactic acid, hygroscopic agent, acetic acid, and water are mixed to obtain a spinning solution;

[0025] The spinning solution was electrospun to obtain the base film;

[0026] An antibacterial agent solution is coated on the upper and lower surfaces of the base film, and then cross-linked in a calcium chloride solution to form an antibacterial layer on the upper and lower surfaces of the base film, thus obtaining the meat product preservation film.

[0027] In this invention, the mass ratio of chitosan, polylactic acid, and hygroscopic agent is preferably 10-20:15-30:1-6, more preferably 12-18:20-27:3-5, and even more preferably 14:25:5.

[0028] In this invention, the preferred ratio of chitosan, acetic acid, and water is 10-20g:10-50mL:100-200mL, more preferably 12-18g:20-40mL:120-160mL, and even more preferably 14g:30mL:150mL.

[0029] In this invention, the molecular weight of the polylactic acid is preferably 10,000 to 100,000, more preferably 40,000 to 80,000, and even more preferably 60,000.

[0030] In this invention, the hygroscopic agent is preferably calcium carbonate or montmorillonite, and more preferably calcium carbonate.

[0031] In this invention, the conditions for electrospinning include: a voltage preferably of 10-20 kV, more preferably 15-18 kV, and even more preferably 16 kV; a receiving distance preferably of 15-20 cm, more preferably 15-17 cm, and even more preferably 16 cm; and an injection speed preferably of 0.3-1 mL / h, more preferably 0.5-1 mL / h, and even more preferably 1 mL / h.

[0032] In this invention, the thickness of the base film is preferably 20-60 μm, more preferably 30-50 μm, and even more preferably 48 μm.

[0033] In this invention, the antibacterial agent solution includes an antibacterial agent and sodium alginate.

[0034] In this invention, the antibacterial agent solution also includes water.

[0035] In this invention, the mass concentration of the antibacterial agent in the antibacterial agent solution is preferably 5-10%, more preferably 7-10%, and even more preferably 9%; the mass concentration of sodium alginate is preferably 3-10%, more preferably 4-6%, and even more preferably 5%.

[0036] In this invention, the coating amount on the upper and lower surfaces is preferably 1 to 5 mL / cm². 2 More preferably 2-4 mL / cm 2 More preferably 3 mL / cm 2 .

[0037] In this invention, the antibacterial agent is preferably one or more of tea polyphenols, cinnamaldehyde, and orange peel extract, more preferably one or two of tea polyphenols and orange peel extract, and even more preferably tea polyphenols and orange peel extract.

[0038] In this invention, the orange peel extract is prepared by: extracting dried orange peel with ethanol at a ratio of 1g:10mL at 40℃ for 24h, followed by distillation to remove the ethanol, thereby obtaining the orange peel extract. All orange peel extracts used in the embodiments of this invention were prepared using this method.

[0039] In this invention, the crosslinking time is preferably 30-120 min, more preferably 50-90 min, and even more preferably 60 min; the crosslinking temperature is preferably 25-50°C, more preferably 27-40°C, and even more preferably 30°C.

[0040] In this invention, the mass concentration of the calcium chloride solution is preferably 1-10%, more preferably 5-8%, and even more preferably 7%.

[0041] In this invention, the thickness of the antibacterial layer on the upper and lower surfaces is preferably 5 to 30 μm, more preferably 15 to 28 μm, and even more preferably 25 μm.

[0042] The present invention also provides a method for preparing a meat product preservation film.

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] This embodiment provides a meat product preservation film, the preparation method of which includes the following steps:

[0046] (1) Chitosan, polylactic acid (molecular weight 60,000), calcium carbonate, acetic acid and water are mixed evenly in a ratio of 14g:25g:5g:30mL:150mL to obtain a spinning solution.

[0047] (2) Electrospinning was performed on the spinning solution under the following conditions: voltage of 16kV, receiving distance of 16cm, injection speed of 1mL / h, to obtain a base film with a thickness of 48μm.

[0048] (3) Using an aqueous solution of 5% (w / w) tea polyphenols, 4% (w / w) orange peel extract, and 5% (w / w) sodium alginate as an antibacterial agent, the antibacterial agent solution was coated on both the upper and lower surfaces of the base film, with a coating amount of 3 mL / cm². 2 Then, crosslinking was performed in a 7% calcium chloride solution at 30°C for 60 minutes. After washing and drying, a 25μm thick antibacterial layer was formed on both the upper and lower surfaces of the base film, resulting in a meat product preservation film.

[0049] Example 2

[0050] This embodiment provides a meat product preservation film, the preparation method of which includes the following steps:

[0051] (1) Chitosan, polylactic acid (molecular weight 60,000), montmorillonite, acetic acid and water are mixed evenly in a ratio of 10g:20g:2g:10mL:100mL to obtain a spinning solution.

[0052] (2) The spinning solution was electrospun under the following conditions: voltage of 12kV, receiving distance of 15cm, and injection speed of 0.5mL / h, to obtain a base film with a thickness of 32μm.

[0053] (3) Using an aqueous solution of 5% cinnamaldehyde and 3% sodium alginate as the antibacterial agent, the antibacterial agent solution was coated on both the upper and lower surfaces of the base film, with a coating amount of 1 mL / cm². 2 Then, crosslinking was performed in a 3% calcium chloride solution at 25°C for 40 minutes. After washing and drying, an antibacterial layer of 17 μm thickness was formed on both the upper and lower surfaces of the base film, resulting in a meat product preservation film.

[0054] Example 3

[0055] This embodiment provides a meat product preservation film, the preparation method of which includes the following steps:

[0056] (1) Chitosan, polylactic acid (molecular weight 60,000), calcium carbonate, acetic acid and water are mixed evenly in a ratio of 17g:27g:3g:20mL:180mL to obtain a spinning solution.

[0057] (2) The spinning solution was electrospun under the following conditions: voltage of 18kV, receiving distance of 16cm, injection speed of 0.8mL / h, to obtain a base film with a thickness of 38μm.

[0058] (3) Using an aqueous solution of 8% (w / w) orange peel extract and 7% (w / w) sodium alginate as the antibacterial agent solution, the antibacterial agent solution was coated on both the upper and lower surfaces of the base film, with a coating amount of 2 mL / cm². 2 Then, crosslinking was performed in a 3% calcium chloride solution at 40°C for 80 minutes. After washing and drying, an antibacterial layer of 21 μm thickness was formed on both the upper and lower surfaces of the base film, resulting in a meat product preservation film.

[0059] Example 4

[0060] This embodiment provides a meat product preservation film, the preparation method of which includes the following steps:

[0061] (1) Chitosan, polylactic acid (molecular weight 60,000), calcium carbonate, acetic acid and water are mixed evenly in a ratio of 10g:30g:6g:50mL:200mL to obtain a spinning solution.

[0062] (2) Electrospinning was performed on the spinning solution under the following conditions: voltage of 20kV, receiving distance of 15cm, injection speed of 1mL / h, to obtain a base film with a thickness of 54μm.

[0063] (3) Using an aqueous solution of 8% (w / w) tea polyphenols and 8% (w / w) sodium alginate as the antibacterial agent, the antibacterial agent solution was coated on both the upper and lower surfaces of the base film, with a coating amount of 4 mL / cm². 2Then, crosslinking was performed in a 5% calcium chloride solution at 25°C for 90 minutes. After washing and drying, an antibacterial layer of 27 μm thickness was formed on both the upper and lower surfaces of the base film, resulting in a meat product preservation film.

[0064] Comparative Example 1

[0065] This comparative example provides a meat product preservation film, specifically referring to Example 1. The difference is that the upper and lower surfaces of the base film do not have an antibacterial layer, that is, step (3) is not performed in the preparation method.

[0066] Comparative Example 2

[0067] This comparative example provides a meat product preservation film, specifically referring to Example 1. The difference is that in the preparation method, after coating with an antibacterial agent solution in step (3), the meat product preservation film is obtained by drying, without cross-linking with calcium chloride solution.

[0068] Comparative Example 3

[0069] This comparative example provides a meat product preservation film, specifically referring to Example 1. The difference is that the antibacterial agent solution in step (3) of the preparation method does not contain sodium alginate and does not undergo cross-linking with calcium chloride solution.

[0070] Comparative Example 4

[0071] This comparative example provides a meat product preservation film, specifically referring to Example 1. The difference is that the antibacterial agent solution in step (3) of the preparation method does not contain natural antibacterial agents such as tea polyphenols and orange peel extract.

[0072] The meat product preservation films prepared in Examples 1-4 and Comparative Examples 1-4 were tested for mechanical properties, antibacterial properties, and oxygen permeability. The results are shown in Table 1.

[0073] Table 1 Performance test results of meat product preservation film

[0074]

[0075]

[0076] As shown in Table 1, the tensile strength of the food preservation film of the present invention can reach 10 MPa, the elongation at break can reach over 100%, the antibacterial performance can reach over 99%, and the oxygen permeability is as low as 17.7 mL / cm². 2 The film possesses excellent oxygen barrier properties, antibacterial properties, and mechanical properties, meeting the requirements for meat product preservation and extending shelf life. Comparative Examples 1 to 3 show that the antibacterial layer on the base film surface affects mechanical properties, antibacterial properties, and oxygen permeability. Furthermore, Comparative Example 4 demonstrates that the natural antibacterial agent used in this invention further enhances the antibacterial properties.

[0077] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a meat product preservation film, characterized in that, Includes the following steps: Chitosan, polylactic acid, hygroscopic agent, acetic acid, and water are mixed to obtain a spinning solution; The spinning solution was electrospun to obtain the base film; An antibacterial agent solution is coated on the upper and lower surfaces of the base film, and then cross-linked in a calcium chloride solution to form an antibacterial layer on the upper and lower surfaces of the base film, thus obtaining the meat product preservation film. The mass ratio of chitosan, polylactic acid, and hygroscopic agent is 10~20:15~30:1~6; The antibacterial agent solution includes an antibacterial agent and sodium alginate; the mass concentration of the antibacterial agent in the antibacterial agent solution is 5-10%; the mass concentration of sodium alginate is 3-10%; the antibacterial agent is one or more of tea polyphenols, cinnamaldehyde, and orange peel extract; The crosslinking time is 30-120 min; the crosslinking temperature is 25-50℃; and the mass concentration of the calcium chloride solution is 1-10%. The thickness of the base film is 20~60µm; The thickness of the antibacterial layer on the upper and lower surfaces is independently 5~30µm.

2. The method for preparing a meat product preservation film according to claim 1, characterized in that, The conditions for electrospinning include: voltage of 10~20kV; receiving distance of 15~20cm; and injection speed of 0.3~1mL / h.

3. The method for preparing a meat product preservation film according to claim 1, characterized in that, The coating amount on the upper and lower surfaces is independently 1~5 mL / cm. 2 .

4. A meat product preservation film prepared by the method of any one of claims 1 to 3.

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