A kind of acetate starch based antibacterial film and preparation method thereof

Abstract

The present invention provides an acetate starch-based antibacterial film and a preparation method thereof, comprising the following steps: (1) uniformly mixing starch with a modified solvent choline acetate aqueous solution to obtain a starch suspension, heating and stirring the starch suspension, adding acetic anhydride thereto for esterification reaction, filtering after the reaction is completed to obtain a precipitate, washing and drying the precipitate to obtain an acetate starch sample; (2) uniformly mixing the acetate starch sample with a plasticizer and antibacterial agent choline acetate aqueous solution, standing for hot pressing to form a film, and obtaining the acetate starch-based antibacterial film. The preparation method of the acetate starch-based antibacterial film of the present invention is simple in process operation and green and environmentally friendly. The prepared acetate starch-based antibacterial film has excellent water-blocking performance, high transparency, good flexibility, and good inhibitory effect on typical food spoilage bacteria (Staphylococcus aureus and Escherichia coli).

Description

Technical Field

[0001] The invention belongs to the field of biodegradable bio-based packaging materials, and in particular relates to an acetate starch-based antibacterial film and a preparation method thereof. Background Art

[0002] With the rapid development of my country's economy and the continuous improvement of living standards, people's requirements for food safety are getting higher and higher. Food microbiological safety, especially the food corruption caused by microorganisms and the safety hazards caused to the human body, has become the focus of the food industry in recent years.

[0003] Traditional food antibacterial films are mainly prepared with synthetic polymer materials as raw materials, and are currently facing problems such as resource depletion, environmental pollution, and threats to human health. In recent years, starch-based antibacterial films prepared with natural starch, which is widely available, low-priced, and renewable, have become one of the most promising bio-based food antibacterial films due to their advantages of being green, environmentally friendly, safe, non-toxic, and biodegradable. However, traditional starch-based antibacterial films have defects such as high hydrophilicity, poor mechanical properties, and the need to add additional antibacterial agents, which greatly limits their application. Therefore, the development of starch-based antibacterial films with good hydrophobicity, mechanical properties, and antibacterial activity has become the focus of scientists.

[0004] The water barrier and mechanical properties of starch-based materials can be improved by chemical hydrophobic modification (esterification, cross-linking and grafting) of natural starch. For example, starch esterification with fatty acids can improve the water barrier and material flexibility of starch-based films. Among these chemical modifications, acetic acid hydrophobic modification is considered to be a simple and effective strategy to improve the water barrier and mechanical properties of starch-based materials. However, the reaction media used in the modification process, such as water, strong acid / base and dimethyl sulfoxide, have disadvantages such as low efficiency, poor safety and single function. In order to overcome these disadvantages, ionic liquids with high safety, green environmental protection and excellent functions have become the focus of attention. Ionic liquids have the advantages of non-volatility, non-flammability, high stability, recyclability and effective dissolution of polysaccharides, so they have been widely used in the synthesis of catalytic modified starch. For example, a variety of highly substituted esterified starches and etherified starches were synthesized using 1-butyl-3-methylimidazolium chloride as the modification solvent, which improved the functional properties of starch such as hydrophobicity, gelatinization properties and thermal stability, and expanded the application range of starch. The hydrophobic modification of starch by acetate can reduce the hydrophilicity of antibacterial materials, prevent the antibacterial agent from being released too quickly and unable to inhibit bacteria for a long time; reduce the regeneration of antibacterial materials, prevent the mechanical properties of materials from decreasing, and thus affect the service life. The development of acetate starch-based antibacterial films has important social significance and economic benefits for ensuring food microbial safety and human health, but the technical methods of preparing acetate starch-based antibacterial films in traditional solvents still have many defects such as low modification efficiency, poor performance, complex preparation methods, more added ingredients, and harm to the environment and human body. Summary of the invention

[0005] In view of this, the present invention aims to overcome the defects in the prior art and proposes an acetate starch-based antibacterial film and a preparation method thereof.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] Choline acetate ([HOCH2CH2N(CH2)2][CH2COO]) is a bio-friendly ionic liquid whose cation is derived from choline chloride, a component of vitamin B4, and whose anion is derived from acetic acid, which can be used as a food additive. Compared with traditional solvents, plasticizers and antibacterial agents, choline acetate can effectively dissolve and plasticize starch, and also has good antibacterial activity.

[0008] We found that mixing ionic liquids with water in a certain ratio can promote the modification of starch while reducing costs. Therefore, we proposed a new idea of ​​using choline acetate aqueous solution to simultaneously play a catalytic modification (dissolution), plasticization and antibacterial role in the preparation of acetate starch-based antibacterial films, thereby regulating the water barrier properties, mechanical properties and antibacterial activity of the antibacterial film.

[0009] The present invention provides a method for preparing an acetate starch-based antibacterial film, comprising the following steps:

[0010] (1) mixing starch and a modified solvent choline acetate aqueous solution to obtain a starch suspension, heating and stirring the starch suspension, adding acetic anhydride thereto to carry out an esterification reaction, filtering after the reaction is completed to obtain a precipitate, washing and drying the precipitate to obtain an acetate starch sample;

[0011] (2) The acetate starch sample is mixed evenly with the plasticizer and antibacterial agent choline acetate aqueous solution, and then hot-pressed to form a film after standing to obtain the acetate starch-based antibacterial film.

[0012] The preparation method is green and simple, and does not require the addition of additional antibacterial agents. The prepared acetate starch-based antibacterial film has the advantages of good water barrier properties, mechanical properties and antibacterial activity, and has good application potential in the field of antibacterial packaging.

[0013] Furthermore, the modified solvent choline acetate aqueous solution in step (1) is prepared by a method comprising the following steps: mixing choline acetate and water in a mass ratio of 7-9:1-3 to obtain the modified solvent choline acetate aqueous solution; preferably, the mass ratio of choline acetate to water is 8:2.

[0014] Furthermore, the solid-to-liquid ratio of the starch in step (1) to the modified solvent choline acetate aqueous solution is 1:5-20; the mass ratio of the starch in step (1) to acetic anhydride is 1-2:1-3; and the starch in step (1) is corn starch.

[0015] Furthermore, the temperature of the heating and stirring step in step (1) is 50-70°C and the time is 1-2 hours; the reaction temperature of the esterification reaction in step (1) is 50-70°C and the reaction time is 1-2 hours.

[0016] Furthermore, the washing step in step (1) is performed 2-4 times; the drying step in step (1) is performed at a temperature of 35-45° C. for 12-24 hours.

[0017] Furthermore, the plasticizer and antibacterial agent choline acetate aqueous solution in step (2) is prepared by a method comprising the following steps: mixing choline acetate and water in a mass ratio of 1-10:1-10 to obtain the plasticizer and antibacterial agent choline acetate aqueous solution; preferably, the mass ratio of choline acetate to water is 4-8:2-6.

[0018] Furthermore, the mass ratio of the acetate starch sample to the plasticizer and antibacterial agent choline acetate aqueous solution in step (2) is 7:3.

[0019] Furthermore, the hot pressing film forming step in step (2) is specifically as follows: first hot pressing at 100-160° C. for 15-30 minutes, then cold pressing at 10-30° C. for 5-10 minutes, and then placing at 10-30° C. and relative humidity of 60-80% for 48-72 hours.

[0020] An acetate starch-based antibacterial film is prepared by the method.

[0021] An application of the starch acetate-based antibacterial film, application of the antibacterial film in the field of food packaging; application of the antibacterial film in the preparation of food antibacterial packaging.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The preparation method of the acetate starch-based antibacterial film of the present invention integrates the characteristics of choline acetate aqueous solution, which has catalytic modification, plasticization and antibacterial effects, and applies it to the preparation of the acetate starch-based antibacterial film, and simultaneously improves the water barrier performance, mechanical properties and antibacterial activity of the antibacterial film with only one solvent: firstly, the acetate starch is synthesized under mild conditions (without the addition of toxic or corrosive catalysts) using the choline acetate aqueous solution as a modification solvent, and the reaction system is green and environmentally friendly; then, the acetate starch-based antibacterial film is prepared using the choline acetate aqueous solution as a plasticizer and an antibacterial agent, which can effectively plasticize the starch and improve the mechanical properties of the film, and can also give the film antibacterial ability, which reduces the use cost and provides a method for synchronously adjusting the material properties and antibacterial activity.

[0024] The raw and auxiliary materials used in the acetate starch-based antibacterial film of the present invention are all biodegradable materials, and the starch used as the raw material is widely available, cheap and easy to obtain. Compared with the starch solvent / plasticizer / antibacterial agent used in the prior art, the choline acetate used in the preparation of the starch-based antibacterial film for the first time in this method has the advantages of being non-volatile, non-flammable, highly stable, and recyclable, as well as multiple capabilities such as dissolving polysaccharides, plasticizing starch, and broad-spectrum antibacterial, and is green, safe, and multifunctional.

[0025] The preparation method of the acetate starch-based antibacterial film of the present invention has simple process operation and is green and environmentally friendly. The prepared acetate starch-based antibacterial film has excellent water barrier performance, high transparency, good flexibility, and has a good inhibitory effect on typical food spoilage bacteria (Staphylococcus aureus and Escherichia coli). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the starch acetate-based antibacterial film according to Example 1 of the present invention;

[0027] Figure 2This is a scanning electron microscope image of the acetate starch-based antibacterial film described in Example 1 of the present invention;

[0028] Figure 3 This is a scanning electron microscope image of the starch-based antibacterial film described in Comparative Example 1 of the present invention;

[0029] FIG4 is a comparison diagram of the contact angles of the antibacterial films of Examples 1-3 of the present invention and Comparative Examples 1-3: 4-A is Example 1, 4-B is Example 2, 4-C is Example 3, 4-D is Comparative Example 1, 4-E is Comparative Example 2, and 4-F is Comparative Example 3;

[0030] Figure 5 A comparison chart of the tensile strength of the antibacterial films described in Examples 1-3 of the present invention and Comparative Examples 1-3;

[0031] Figure 6 A comparison chart of the elongation at break of the antibacterial films described in Examples 1-3 of the present invention and Comparative Examples 1-3;

[0032] Figure 7 The figure is a comparison chart of the antibacterial activity of the antibacterial films described in Examples 1-3 of the present invention and Comparative Examples 1-3. DETAILED DESCRIPTION

[0033] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0034] The corn starch used in the embodiment of the present invention has an amylose content of 22.4% and a water content of 10.1%.

[0035] The present invention will be described in detail below with reference to the embodiments.

[0036] Example 1

[0037] A method for preparing an acetate starch-based antibacterial film comprises the following steps:

[0038] (1) adding choline acetate to water, mixing them evenly at room temperature, and preparing a plasticizer and antibacterial agent choline acetate aqueous solution with a mass ratio of choline acetate to water of 4:6 and a modified solvent choline acetate aqueous solution with a mass ratio of 8:2;

[0039] (2) Add corn starch to the modified solvent choline acetate aqueous solution, stir evenly, prepare a starch suspension with a mass percentage concentration of 10%, stir at 50° C. for 1 hour, then add acetic anhydride twice the mass of the starch, keep stirring at 50° C. for 2 hours, cool and centrifuge at 5000 r / min for 15 minutes, remove the supernatant, wash the precipitate with 50 ml of water and filter, repeat 3 times, dry at 40° C. for 24 hours, crush and pass through an 80-mesh sieve to obtain an acetate starch sample;

[0040] (3) the obtained acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution were mixed uniformly at room temperature in a mass ratio of 7:3, and then allowed to stand for 4 hours to allow the acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution to fully react;

[0041] (4) The product obtained in step (3) is hot-pressed at 100° C. for 20 min, then cold-pressed at 25° C. for 5 min, and then placed at 25° C. and 75% relative humidity for 72 h to obtain an acetate starch-based antibacterial film, such as Figure 1 shown.

[0042] Example 2

[0043] A method for preparing an acetate starch-based antibacterial film comprises the following steps:

[0044] (1) adding choline acetate to water, mixing them evenly at room temperature, and preparing a plasticizer and antibacterial agent choline acetate aqueous solution with a mass ratio of choline acetate to water of 6:4 and a modified solvent choline acetate aqueous solution with a mass ratio of 8:2;

[0045] (2) Add corn starch to the modified solvent choline acetate aqueous solution, stir evenly, prepare a starch suspension with a mass percentage concentration of 10%, stir at 50° C. for 1 hour, then add acetic anhydride twice the mass of the starch, keep stirring at 50° C. for 2 hours, cool and centrifuge at 5000 r / min for 15 minutes, remove the supernatant, wash the precipitate with 50 ml of water and filter, repeat 3 times, dry at 40° C. for 24 hours, crush and pass through an 80-mesh sieve to obtain an acetate starch sample;

[0046] (3) the obtained acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution were mixed uniformly at room temperature in a mass ratio of 7:3, and then allowed to stand for 4 hours to allow the acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution to fully react;

[0047] (4) The product obtained in step (3) was hot-pressed at 100° C. for 20 min, then cold-pressed at 25° C. for 5 min, and then placed at 25° C. and 75% relative humidity for 72 h to obtain an acetate starch-based antibacterial film.

[0048] Example 3

[0049] A method for preparing an acetate starch-based antibacterial film comprises the following steps:

[0050] (1) adding choline acetate to water, mixing them evenly at room temperature, and preparing a plasticizer and antibacterial agent choline acetate aqueous solution with a mass ratio of choline acetate to water of 8:2 and a modified solvent choline acetate aqueous solution with a mass ratio of 8:2;

[0051] (2) Add corn starch to the modified solvent choline acetate aqueous solution, stir evenly, prepare a starch suspension with a mass percentage concentration of 10%, stir at 50° C. for 1 hour, then add acetic anhydride twice the mass of the starch, keep stirring at 50° C. for 2 hours, cool and centrifuge at 5000 r / min for 15 minutes, remove the supernatant, wash the precipitate with 50 ml of water and filter, repeat 3 times, dry at 40° C. for 24 hours, crush and pass through an 80-mesh sieve to obtain an acetate starch sample;

[0052] (3) The obtained acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution were mixed evenly at room temperature in a mass ratio of 7:3, and then allowed to stand for 4 hours to allow the acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution to fully react;

[0053] (4) The product obtained in step (3) was hot-pressed at 100° C. for 20 min, then cold-pressed at 25° C. for 5 min, and then placed at 25° C. and 75% relative humidity for 72 h to obtain an acetate starch-based antibacterial film.

[0054] Comparative Example 1

[0055] A method for preparing a starch-based antibacterial film comprises the following steps:

[0056] (1) adding choline acetate to water, mixing evenly at room temperature, and preparing a plasticizer and antibacterial agent choline acetate aqueous solution with a mass ratio of choline acetate to water of 4:6;

[0057] (2) adding corn starch to the obtained choline acetate aqueous solution, mixing them evenly at room temperature in a mass ratio of 7:3 between the corn starch and the plasticizer and antibacterial agent choline acetate aqueous solution, and then leaving them for 4 hours to allow the corn starch and the plasticizer and antibacterial agent choline acetate aqueous solution to fully react;

[0058] (3) The mixture obtained in step (2) was hot-pressed at 100° C. for 20 min, then cold-pressed at 25° C. for 5 min, and then placed at 25° C. and 75% relative humidity for 72 h to obtain a natural starch-based antibacterial film.

[0059] Comparative Example 2

[0060] A method for preparing an acetate starch-based antibacterial film comprises the following steps:

[0061] (1) adding choline acetate to water, mixing them evenly at room temperature, and preparing a plasticizer and antibacterial agent choline acetate aqueous solution with a mass ratio of choline acetate to water of 4:6 and a modified solvent choline acetate aqueous solution with a mass ratio of 4:6;

[0062] (2) Add corn starch to the modified solvent choline acetate aqueous solution, stir evenly, prepare a starch suspension with a mass percentage concentration of 10%, stir at 50° C. for 1 hour, then add acetic anhydride twice the mass of the starch, keep stirring at 50° C. for 2 hours, cool and centrifuge at 5000 r / min for 15 minutes, remove the supernatant, wash the precipitate with 50 ml of water and filter, repeat 3 times, dry at 40° C. for 24 hours, crush and pass through an 80-mesh sieve to obtain an acetate starch sample;

[0063] (3) the obtained acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution were mixed uniformly at room temperature in a mass ratio of 7:3, and then allowed to stand for 4 hours to allow the acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution to fully react;

[0064] (4) The product obtained in step (3) was hot-pressed at 100° C. for 20 min, then cold-pressed at 25° C. for 5 min, and then placed at 25° C. and 75% relative humidity for 72 h to obtain an acetate starch-based antibacterial film.

[0065] Comparative Example 3

[0066] A method for preparing an acetate starch-based antibacterial film comprises the following steps:

[0067] (1) adding choline glycinate to water, mixing them evenly at room temperature, and preparing a plasticizer and antibacterial agent choline glycinate aqueous solution with a mass ratio of choline glycinate to water of 4:6 and a modified solvent choline glycinate aqueous solution with a mass ratio of 8:2;

[0068] (2) Add corn starch to the modified solvent choline glycine salt aqueous solution, stir evenly, prepare a starch suspension with a mass percentage concentration of 10%, stir at 50° C. for 1 hour, then add acetic anhydride twice the mass of the starch, keep stirring at 50° C. for 2 hours, cool and centrifuge at 5000 r / min for 15 minutes, remove the supernatant, wash the precipitate with 50 ml of water and filter, repeat 3 times, dry at 40° C. for 24 hours, crush and pass through an 80-mesh sieve to obtain an acetate starch sample;

[0069] (3) the obtained acetate starch sample and the plasticizer and antibacterial agent choline glycinate aqueous solution were mixed evenly at room temperature in a mass ratio of 7:3, and then allowed to stand for 4 hours to allow the acetate starch sample and the plasticizer and antibacterial agent choline glycinate aqueous solution to fully react;

[0070] (4) The product obtained in step (3) was hot-pressed at 100° C. for 20 min, then cold-pressed at 25° C. for 5 min, and then placed at 25° C. and 75% relative humidity for 72 h to obtain an acetate starch-based antibacterial film.

[0071] Performance testing method:

[0072] Determination of microstructure: The microstructure of the film samples was observed using a SU1510 scanning electron microscope (SEM) from Hitachi, Japan.

[0073] Contact angle test: The contact angle of the film to the water droplet was measured using the PGX-50757 dynamic contact angle tester produced by Swedish FIBRO Company to characterize the affinity and repellency of the film to water.

[0074] Mechanical properties test: The film samples were placed in an environment with a temperature of 23±1°C and a relative humidity of 75±2% for 12 hours. The tensile strength (MPa) and elongation at break (%) of the film were measured using a universal material testing machine (QJ211S) from Shanghai Qingji Company, with a tensile rate of 10 mm / min.

[0075] Determination of antibacterial properties: The antibacterial properties of the film against Staphylococcus aureus and Escherichia coli were tested by colony formation counting method. The film sample (10 mg) was immersed in 5 mL of bacterial suspension, and the suspension was cultured in a shaker at 37 ° C for 5 h. Subsequently, 100 μL of bacterial suspension was dispersed on an agar plate three times and cultured at 37 ° C for 24 h. The colonies were counted and the bacterial activity was calculated as follows:

[0076] Bacterial activity (%) = Number of colonies formed by adding film / Number of colonies formed by not adding film × 100%

[0077] The relevant test results of the antibacterial films prepared in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0078] Table 1 Performance test results

[0079]

[0080]

[0081] Depend on Figure 1 It can be seen that the acetate starch-based antibacterial film prepared in the example is a transparent film.

[0082] Depend on Figure 2 and Figure 3 It can be seen that compared with the comparative example, the surface of the acetate starch-based antibacterial film prepared in the example is smoother and flatter.

[0083] It can be seen from Table 1 that compared with Comparative Examples 1-3, the contact angle of the acetate starch-based antibacterial film prepared in Examples 1-3 is larger, and therefore has better water-blocking properties; the contact angle comparison results of Example 3 and Example 1-2 show that a higher choline acetate concentration increases the hydrophobicity of the acetate starch-based antibacterial film.

[0084] Compared with Comparative Examples 1-3, the acetate starch-based antibacterial film prepared in Examples 1-3 has greater tensile strength and elongation at break, and therefore has better mechanical properties; the comparison results of the mechanical properties of Example 3 and Example 1-2 show that a higher choline acetate concentration increases the elongation at break of the acetate starch-based antibacterial film and reduces the tensile strength of the film, and therefore the flexibility of the film is better.

[0085] Compared with Comparative Examples 1-3, the acetate starch-based antibacterial film prepared in Examples 1-3 has a stronger inhibitory effect on Staphylococcus aureus and Escherichia coli, and therefore has better antibacterial performance; the mechanical properties comparison results between Example 3 and Example 1-2 show that the higher choline acetate concentration in the acetate starch-based antibacterial film significantly reduces bacterial activity, and therefore the film has a stronger antibacterial ability.

[0086] In summary, we found that the process of preparing antibacterial film in choline acetate aqueous solution is simple and green, without the need to add additional antibacterial agents, and the prepared acetate starch-based antibacterial film has good water barrier properties, mechanical properties and antibacterial activity, and has great application potential in fresh food preservation packaging, food antibacterial packaging, food storage, etc.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an acetate starch-based antibacterial film, characterized in that: The steps include: (1) Mixing starch and a modified solvent choline acetate aqueous solution uniformly to obtain a starch suspension, heating and stirring the starch suspension, adding acetic anhydride thereto to carry out an esterification reaction, filtering after the reaction is completed to obtain a precipitate, washing and drying the precipitate to obtain an acetate starch sample; (2) mixing the acetate starch sample and the plasticizer and antibacterial agent choline acetate aqueous solution evenly, allowing to stand for a while and then hot pressing to form a film, thereby obtaining the acetate starch-based antibacterial film; The modified solvent choline acetate aqueous solution in step (1) is prepared by a method comprising the following steps: mixing choline acetate and water in a mass ratio of 8:2 to obtain the modified solvent choline acetate aqueous solution.

2. The method for preparing the starch acetate-based antibacterial film according to claim 1, characterized in that: The solid-to-liquid ratio of the starch in the step (1) to the modified solvent choline acetate aqueous solution is 1:5-20; the mass ratio of the starch in the step (1) to acetic anhydride is 1-2:1-3; the starch in the step (1) is corn starch.

3. The method for preparing the starch acetate-based antibacterial film according to claim 1, characterized in that: The temperature of the heating and stirring step in step (1) is 50-70°C and the time is 1-2 hours; the reaction temperature of the esterification reaction in step (1) is 50-70°C and the reaction time is 1-2 hours.

4. The method for preparing the starch acetate-based antibacterial film according to claim 1, characterized in that: The washing step in step (1) is performed 2-4 times; the drying step in step (1) is performed at a temperature of 35-45° C. and for a time of 12-24 hours.

5. The method for preparing the starch acetate-based antibacterial film according to claim 1, characterized in that: The plasticizer and antibacterial agent choline acetate aqueous solution in step (2) is prepared by a method comprising the following steps: mixing choline acetate and water in a mass ratio of 1-10:1-10 to obtain the plasticizer and antibacterial agent choline acetate aqueous solution.

6. The method for preparing the starch acetate-based antibacterial film according to claim 5, characterized in that: The mass ratio of choline acetate to water is 4-8: 2-6.

7. The method for preparing the starch acetate-based antibacterial film according to claim 1, characterized in that: The mass ratio of the acetate starch sample to the plasticizer and antibacterial agent choline acetate aqueous solution in step (2) is 7:

3.

8. The method for preparing the starch acetate-based antibacterial film according to claim 1, characterized in that: The hot pressing film forming step in step (2) is specifically as follows: first hot pressing at 100-160°C for 15-30 minutes, then cold pressing at 10-30°C for 5-10 minutes, and then placing at 10-30°C and relative humidity of 60-80% for 48-72 hours.

9. An acetate starch-based antibacterial film, characterized in that: The antibacterial film is prepared by the method described in any one of claims 1 to 8.

10. An application of the starch acetate-based antibacterial film according to claim 9, characterized in that: Application of the antibacterial film in the field of food packaging.

11. The use according to claim 10, characterized in that: The antibacterial film is used in preparing food antibacterial packaging.

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