CN111286056B - Preparation method of nano antioxidant film - Google Patents

Abstract

The invention provides a preparation method of a nanometer anti-oxidation film. The technical scheme uses gelatin, glycerol, tocopherol, Tween and deionized water in specific proportions as raw materials to prepare gelatin-glycerol aqueous solution and oily solution respectively, and after mixing the two, first perform homogenization treatment to obtain a composite gelatin film liquid , and then combined high-pressure homogenization and ultrasound to process the composite gelatin membrane liquid, so that the membrane liquid is simultaneously subjected to the mechanical effect from high-pressure homogenization and the cavitation from ultrasound. The shear force generated by high-pressure homogenization and the bubbles generated by ultrasonic cavitation make the oil droplets in the composite gelatin solution form nanoparticles and evenly disperse in the solution. Tensile strength, elongation at break and light barrier properties, low film thickness and water vapor permeability, and high oxidation resistance, can be used as functional food packaging materials in the food industry.

Description

A kind of preparation method of nanometer anti-oxidation film

technical field

The invention relates to the technical field of gelatin films, in particular to a preparation method of a nanometer antioxidant film.

Background technique

In recent years, edible film has become a hot spot in the field of food packaging due to its edible safety and environmental degradability. Gelatin is a protein-derived biomaterial with good film-forming properties and biocompatibility. Pure gelatin films have poor physical properties, low biological activity, and are not ideal in terms of tensile strength, light barrier properties, film thickness, and water vapor permeability, and their oxidation resistance is poor. Modified to suit the process requirements in the food packaging field.

At present, the commonly used additive for preparing antioxidant gelatin film is essential oil, and the strong odor of essential oil affects the application of gelatin film in the food field; at the same time, due to the large particles of oily components (essential oils) dispersed in the gelatin film, it hinders the protein-protein interaction. The mechanical properties and biological activities of the composite membranes did not reach the optimum state due to the interaction.

SUMMARY OF THE INVENTION

The present invention aims to provide a method for preparing a nano-antioxidation film in view of the technical defects of the prior art, so as to solve the technical problem in the prior art that the physical properties of conventional gelatin films need to be improved.

Another technical problem to be solved by the present invention is that the conventional gelatin film has poor oxidation resistance.

Another technical problem to be solved by the present invention is how to avoid the introduction of the prominent odor of essential oils while achieving the anti-oxidation property of the gelatin film.

To achieve the above technical purpose, the present invention adopts the following technical solutions:

A preparation method of nano anti-oxidation film, comprising the following steps:

1) formula with the following composition by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, deionized water balance;

2) Mix the gelatin of the formula with water, dissolve at 60°C for 90min, and continue stirring during this period until the gelatin is completely dissolved;

3) cooling the gelatin solution obtained in step 2) to room temperature, adding the glycerol of the formula amount to it, and mixing evenly to obtain a gelatin-glycerol aqueous solution;

4) mix the tocopherol and Tween of the formula amount, and fully shake the oscillator to obtain an oily solution;

5) mixing the gelatin-glycerol aqueous solution obtained in step 3) with the oily solution obtained in step 4), and homogenizing for 3 min with a homogenizer under the condition of 13000 rpm to obtain a composite gelatin film liquid;

6) Mix the composite gelatin film liquid (also known as gelatin emulsion) obtained in step 5) under high pressure homogenization conditions of 80-100 MPa

7) ultrasonically treating the mixed product in step 6) for 10 minutes under the condition of 400-600w to obtain the film liquid before film formation;

8) Perform film formation with the film liquid before film formation obtained in step 7).

Preferably, the film formation described in step 8) includes: pouring the film liquid before film formation into a plate, drying at room temperature for 48 hours under ventilation conditions; placing the dried film in a relative humidity of 50% The airtight environment was equilibrated for 24h, and the nano-antioxidant film was obtained after peeling off.

Preferably, the plate is a plastic plate of 90mm×90mm, and the amount of the film liquid poured into the plate before film formation is 4mL.

Preferably, the Tween is Tween 80.

Preferably, the freezing force of the gelatin in steps 1) and 2) is 260-270.

Preferably, in step 2), during the dissolving process, the port of the container is continuously closed with a plastic wrap (to prevent the long-term heating process from volatilizing the water in the solution and affecting the concentration of gelatin in the solution).

Preferably, the number of high-pressure cycles in step 6) is 3 times.

Preferably, the ultrasonic treatment described in step 7) is realized by using an ultrasonic crusher, the frequency is 20 kHz, the horn of 6 mm is selected, and the ultrasonic treatment is stopped for 2 s every 2 s.

Preferably, the drying for 48 hours is carried out under the conditions of a temperature of 25±2° C. and a relative humidity of 50±5%.

The invention provides a preparation method of a nanometer anti-oxidation film. The technical scheme uses gelatin, glycerol, tocopherol, Tween, and deionized water in specific proportions as raw materials to prepare gelatin-glycerol aqueous solution and oily solution, respectively, after mixing the two, first perform homogenization treatment to obtain composite gelatin film liquid , and then combined high-pressure homogenization and ultrasound to process the composite gelatin membrane fluid, so that the membrane fluid is simultaneously subjected to mechanical effects from high-pressure homogenization and cavitation from ultrasound. The shear force generated by high-pressure homogenization and the bubbles generated by ultrasonic cavitation make the oil droplets in the composite gelatin solution form nanoparticles and evenly disperse in the solution. The nano-antioxidant gelatin film thus formed has high tensile strength Tensile strength, elongation at break and light barrier properties, low film thickness and water vapor permeability, and high oxidation resistance, can be used as functional food packaging materials in the food industry.

In order to improve the performance of pure gelatin film, adding oily tocopherol in the preparation process of gelatin film can enhance the elongation at break and light barrier property of the film, and the antioxidant property of the gelatin film is also enhanced by the addition of tocopherol; At the same time, the physical properties and biological activities of the composite membranes are affected by the size and distribution of oily particles (tocopherols). By preparing nano-scale composite membranes by high pressure homogenization and ultrasonic assistance, the physical properties and biological activities of the nanocomposite membranes are further improved. enhanced.

The nano-antioxidant film prepared by the method has no unpleasant and prominent odor, and has good mechanical properties, waterproof performance and light blocking performance, and the anti-oxidation property is also higher than that of the non-nano-level anti-oxidation film, which can be used as a kind of anti-oxidation film. Functional food packaging materials are used in the food industry.

The beneficial effects of the present invention are embodied in the following aspects: the present invention prepares the nano oil droplet particles through the combination of high pressure homogenization and ultrasound, thereby producing the following effects on the formation of the composite gelatin film: The inside is uniformly distributed, which is conducive to the formation of a lower film thickness; 2. The nano-scale oil droplets are small in size, which reduces the hindrance between gelatin protein and protein, and enhances the interaction between protein and protein. Increase the tensile strength and elongation at break of the gelatin film; 3. Nano-scale oil droplet particles enhance the dispersive ability of oil droplets, thereby enhancing the film's blocking ability to light; 4. Nano-scale oil droplet particles make The increase of the specific surface area of the oil droplets makes it more difficult for water vapor molecules to pass through the membrane, and the contact area between the tocopherol oil droplet particles and oxidizing substances increases, thereby reducing the water vapor permeability of the membrane and enhancing the oxidation resistance. The present invention can be used as a functional material in the field of food packaging.

Compared with the preparation method of the common composite film, the present invention can greatly reduce the amount of surface activity used, and the product safety factor is high; The adverse effect caused by the prominent odor of conventional antioxidants (essential oils) on the gelatin film; compared with the product properties of the traditional composite gelatin film, the nano-antioxidative gelatin film prepared by the method of the present invention has higher tensile strength and light blocking performance , lower film thickness and water vapor permeability, and higher oxidation resistance, which improves the functionality and application value of the composite gelatin film.

Description of drawings

FIG. 1 is a comparison diagram of the oxidation resistance of the composite gelatin films obtained by each example and a comparative example in the specific embodiment of the present invention.

Detailed ways

Specific embodiments of the present invention will be described in detail below. In order to avoid unnecessary details, well-known structures or functions will not be described in detail in the following embodiments. The language of approximation used in the following examples can be used for quantitative expressions, showing that some variation in quantity is permissible without changing the basic function. Unless defined otherwise, technical and scientific terms used in the following examples have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

A preparation method of nano anti-oxidation film, comprising the following steps:

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (5) is mixed under the high pressure homogenization condition of 80～100MPa;

(7) ultrasonicating the gelatin emulsion of step (6) under the condition of 400～600w for 10min to obtain the film liquid before film formation;

(8) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(9) The dried film is placed in a closed environment with a relative humidity of 50% for equilibrium for 24 hours, and the nano-antioxidant film is obtained after peeling off.

Wherein, the gelatin freezing power in step (1) is 260-270.

Step (2) When the gelatin is heated in an aqueous solution at 60° C., it should be sealed with a plastic wrap to prevent the water in the solution from volatilizing during the long-term heating process and affect the concentration of gelatin in the solution.

The number of high pressure cycles in step (6) is 3 times.

The ultrasonic device in step (7) is an ultrasonic crusher, the frequency is 20 kHz, the horn of 6 mm is selected, the ultrasonic wave is ultrasonic for 2 s, and the stop is 2 s.

The drying conditions in step (8) are carried out under the conditions of 25±2° C. and relative humidity of 50±5%.

The above method adopts a combination of high-pressure homogenization and ultrasound to process the composite gelatin film liquid to prepare a nano-level antioxidant gelatin film. The combination of high-pressure homogenization and ultrasonication makes the oil droplets in the gelatin film form nanoparticles, thereby preparing a nano-scale anti-oxidative gelatin film. On the one hand, the gelatin film added with tocopherol endows the gelatin film with good anti-oxidation properties, and at the same time increases the elongation at break of the gelatin film; The nanogelatin films prepared by the combination have higher oxidation resistance, tensile strength and elongation at break, and lower water vapor permeability. The nano-level antioxidant gelatin film prepared by the method has better physical properties and higher oxidation resistance, and can be used as a functional packaging material in the field of food packaging. The nano-antioxidative gelatin film prepared by the method has good mechanical properties, water vapor permeability and light barrier properties, and the film has high antioxidative properties, and can be used as a functional food packaging material.

Example 1

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (5) is mixed under the high pressure homogenization condition of 80MPa;

(7) the gelatin emulsion of step (6) is ultrasonicated 10min under the condition of 400w, obtains the film liquid before film formation;

(8) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(9) The dried film is placed in a closed environment with a relative humidity of 50% for equilibrium for 24 hours, and the nano-antioxidant film is obtained after peeling off.

Example 2

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (5) is mixed under the high pressure homogenization condition of 80MPa;

(7) the gelatin emulsion of step (6) is ultrasonicated 10min under the condition of 600w, obtains the film liquid before film-forming;

(8) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(9) The dried film is placed in a closed environment with a relative humidity of 50% for equilibrium for 24 hours, and the nano-antioxidant film is obtained after peeling off.

Example 3

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (5) is mixed under the high pressure homogenization condition of 100MPa;

(7) the gelatin emulsion of step (6) is ultrasonicated 10min under the condition of 400w, obtains the film liquid before film formation;

(8) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(9) The dried film is placed in a closed environment with a relative humidity of 50% for equilibrium for 24 hours, and the nano-antioxidant film is obtained after peeling off.

Example 4

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (5) is mixed under the high pressure homogenization condition of 100MPa;

(7) the gelatin emulsion of step (6) is ultrasonicated 10min under the condition of 600w, obtains the film liquid before film-forming;

(8) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(9) The dried film is placed in a closed environment with a relative humidity of 50% for equilibrium for 24 hours, and the nano-antioxidant film is obtained after peeling off.

Comparative Example 1

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(7) Put the dried film into a closed environment with a relative humidity of 50% to balance for 24 hours, and remove the film to obtain a composite gelatin film.

Comparative Example 2

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (5) is mixed under the high pressure homogenization condition of 100MPa;

(7) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(8) Put the dried film into a closed environment with a relative humidity of 50% to balance for 24 hours, and remove the film to obtain a composite gelatin film.

Comparative Example 3

(1) Select the following materials in parts by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, and the rest are deionized water, totaling 100%.

(2) Mix gelatin and water in parts by weight, dissolve in an aqueous solution at 60° C. for 90 minutes, and keep stirring until the gelatin is completely dissolved.

(3) cooling the aqueous gelatin solution of step (2) to room temperature, adding glycerol solution in parts by weight, and mixing uniformly to obtain gelatin-glycerol aqueous solution;

(4) tocopherol and Tween 80 are mixed by weight, and fully shaken with a vibrator to obtain an oily solution;

(5) mixing the aqueous solution of step (3) and the oily solution of step (4), and homogenizing for 3min under the condition of 13000rpm with a homogenizer to obtain a composite gelatin film liquid;

(6) the gelatin emulsion of step (6) is ultrasonicated 10min under the condition of 600w, obtains the film liquid before film-forming;

(7) Pour 4ml of the film liquid into a 90mm*90mm plastic dish, and dry it for 48h under room temperature ventilation;

(8) Put the dried film into a closed environment with a relative humidity of 50% to balance for 24 hours, and remove the film to obtain a composite gelatin film.

Example 5

Film thickness, water vapor transmission rate, tensile strength, elongation at break, water solubility and Transmittance detection.

The detection method is as follows:

1. Measurement of Nanogelatin Film Thickness

The thickness of the film was measured with an electronic helical micrometer, and the measurement results are shown in Table 1.

2. Testing of mechanical properties of nano-gelatin films

The composite gelatin films were tested for tensile strength (TS) and elongation at break (EAB) with a texture analyzer. Cut the film into strips with a width of 20mm and a length of 50mm, fix the film on both ends of the instrument handle, adjust the distance between the two ends of the handle to 30mm, the test speed is 1mm/s, and the activating force is 20.0g. The test structure is shown in Table 1.

TS(MPa)= _Fmax /A

EAB(%)=(L ₀ /ΔL)×100%

where _Fmax is the maximum load (N) required to separate the strip film sample, A is the cut surface area (m ² ) of the sample film, L ₀ is the initial stretch length of the film, and ΔL is the stretch length after film breakage , L ₀ =30mm.

3. Test of water vapor permeability of nano-gelatin film

Dry CaCl ₂ was placed in a glass with a diameter of 40 mm and a depth of 25 mm, and the glass was sealed with a membrane. Place the glass in an airtight container containing deionized water and adjust the ambient temperature to 30°C. Measure the weight of the glass every hour until the weight of the glass does not change significantly, stop measuring. The water vapor permeability of the membrane is calculated by the following formula:

WVP(gm ^-1 s ^-1 Pa ^-1 )=wlA ^-1 t ^-1 (P ₂ -P ₁ ) ^-1 ,

w represents the weight of the glass growing (g), l is the thickness of the film (m), A is the area of the film seal (m ² ), t is the time for the weight of the glass to change (s), P ₂ -P ₁ is the film Vapor pressure difference on both sides (4244.9Pa at 30°C). The test structure is shown in Table 1.

4. Test of light barrier properties of nano-gelatin film

The light-blocking properties of the films were measured with a spectrophotometer, with an azimuth of visible light between 200 nm and 800 nm. The test structure is shown in Table 2.

5. DPPH free radical scavenging ability

Prepare a 0.1 mmol/l DPPH solution with absolute ethanol and store in the dark. Add 2ml of the test sample solution and 2ml of DPPH solution into the same test tube, shake well, and stand in the dark for 30min at room temperature to measure the absorbance A ₁ , and simultaneously measure the absorbance A ₀ of 2ml of DPPH solution mixed with 2ml of solvent. The calculation formula of DPPH is: :

A ₀ is the absorbance of DPPH at 520 nm when no sample is added, and A ₁ is the absorbance of the sample and DPPH reagent at 520 nm. The test results are shown in Figure 1.

Table 1 Data of film thickness, tensile strength, elongation at break and water vapor permeability of composite gelatin films

Table 2 Light barrier data of composite gelatin film

The embodiments of the present invention have been described in detail above, but the above contents are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the scope of the application of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. a preparation method of nano anti-oxidation film is characterized in that comprising the following steps: 1) formula with the following composition by weight: gelatin 8%, glycerol 1%, tocopherol 4%, Tween 0.8%, deionized water balance; 2) Mix the gelatin of the formula with water, dissolve at 60°C for 90min, and continue stirring during this period until the gelatin is completely dissolved; 3) cooling the gelatin solution obtained in step 2) to room temperature, adding the glycerol of the formula amount to it, and mixing evenly to obtain a gelatin-glycerol aqueous solution; 4) mix the tocopherol and Tween of the formula amount, and fully shake the oscillator to obtain an oily solution; 5) mixing the gelatin-glycerol aqueous solution obtained in step 3) with the oily solution obtained in step 4), and homogenizing for 3 min with a homogenizer under the condition of 13000 rpm to obtain a composite gelatin film liquid; 6) mixing the composite gelatin film liquid obtained in step 5) under a high pressure homogenization condition of 80-100 MPa; 7) ultrasonically treating the mixed product in step 6) for 10 minutes under the condition of 400-600w to obtain the film liquid before film formation; 8) Perform film formation with the film liquid before film formation obtained in step 7). 2. the preparation method of a kind of nano anti-oxidation film according to claim 1, it is characterized in that carrying out film forming described in step 8), comprises: pouring the film liquid before described film forming into the plate, in Drying at room temperature for 48 hours under ventilation conditions; placing the dried film in a closed environment with a relative humidity of 50% to balance for 24 hours, and peeling it off to obtain the nano-antioxidant film. 3. The preparation method of a nano-antioxidant film according to claim 2, wherein the plate is a plastic plate of 90mm×90mm, and the pouring amount of the film liquid into the plate before film formation is 4mL. 4. the preparation method of a kind of nano anti-oxidation film according to claim 1, is characterized in that described Tween is Tween 80. 5 . The method for preparing a nano-antioxidant film according to claim 1 , wherein the gelatin has a freezing force of 260-270 in steps 1) and 2). 6 . 6 . The method for preparing a nano-antioxidant film according to claim 1 , wherein in step 2), during the dissolving process, the port of the container is continuously closed with a plastic wrap. 7 . 7. The preparation method of a nano-antioxidant film according to claim 1, wherein the number of high-pressure cycles in step 6) is 3 times. 8. the preparation method of a kind of nano anti-oxidation film according to claim 1, it is characterized in that the ultrasonic treatment described in step 7), is to utilize ultrasonic crusher to realize, frequency is 20kHz, selects the horn of 6mm, Every 2s of sonication, stop for 2s. 9 . The method for preparing a nano-antioxidant film according to claim 2 , wherein the drying for 48 hours is carried out under the conditions of a temperature of 25±2° C. and a relative humidity of 50±5%. 10 .

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