Nanofiber preservative film prepared by solution blowing spinning and used for intelligently monitoring freshness of fish meat and application of nanofiber preservative film

Abstract

The embodiment of the invention relates to a nanofiber preservative film prepared through solution blowing and used for intelligently monitoring freshness of fish meat and application of the nanofiber preservative film, and belongs to the technical field of preservative films. The preparation method of the nanofiber preservative film in the embodiment of the invention comprises the following steps: dissolving yellow-fin tuna skin gelatin in an acetic acid solution, adding chitosan after the yellow-fin tuna skin gelatin is completely dissolved, and uniformly stirring to obtain a yellow-fin tuna skin gelatin / chitosan blended solution; adding anthocyanin and curcumin into the yellow fin tuna skin gelatin / chitosan blended solution, and uniformly stirring to obtain a spinning solution; blowing and spinning the spinning solution, and collecting by using release paper to obtain the nanofiber preservative film. According to the nanofiber preservative film disclosed by the invention, the instability of the anthocyanin is made up by utilizing the anti-oxidation characteristic of the curcumin, and the color change limitation range of the curcumin is supplemented by a wide color change interval of the anthocyanin.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of cling film, and in particular to a nanofiber cling film prepared by solution blowing and capable of intelligently monitoring the freshness of fish meat, and applications thereof. Background Art

[0002] Tuna is delicious and red in texture. It is rich in unsaturated fatty acids and trace elements. It lives in an environment with little pollution and is known as "undersea gold". The seven common types of tuna are skipjack tuna, yellowfin tuna, albacore tuna, bigeye tuna, Atlantic tuna, northern bluefin tuna, and bluefin tuna. Tuna meat contains high levels of myoglobin and is easily oxidized and browned. Therefore, its storage conditions are relatively harsh. During storage, if it is not properly handled, it often leads to the deterioration of tuna meat and a decline in quality.

[0003] Solution blow spinning (SBS) is more economical and has higher productivity in preparing nanofibers, and does not require high voltage power supply. Currently, solution blown chitosan nanofibers are mostly blended with other polymers, with low chitosan content; at the same time, they are loaded with antibiotics or antioxidants. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a nanofiber cling film prepared by solution blowing and capable of intelligently monitoring the freshness of fish meat, and its application. The nanofiber cling film can monitor the freshness of fish meat food in real time, and has excellent antioxidant and antibacterial properties. It can be widely used in the field of food preservation materials and can effectively overcome the defects of the above-mentioned prior art.

[0005] A first aspect of the present application provides a method for preparing a nanofiber cling film, comprising the following steps:

[0006] Firstly, yellowfin tuna skin gelatin is dissolved in acetic acid solution, and chitosan is added after the yellowfin tuna skin gelatin is completely dissolved, and the mixture is stirred evenly to obtain a yellowfin tuna skin gelatin / chitosan blended solution; anthocyanin and curcumin are then added to the yellowfin tuna skin gelatin / chitosan blended solution, and the mixture is stirred evenly to obtain a spinning solution; the spinning solution is blown and collected with release paper to obtain a nanofiber cling film.

[0007] Specifically, the preparation process of the yellowfin tuna skin gelatin / chitosan / curcumin / anthocyanidin spinning solution is as follows: in a 20mL beaker, first add 3mL of acetic acid solution, then add 7mL of deionized water, start stirring on a stirrer, then add 2g of gelatin, and after it is completely dissolved, add 0.15g of chitosan while stirring, and after it is completely mixed and dispersed, add 0.04g of a mixture of curcumin and anthocyanidins with a mass ratio of 8:2, and also add while stirring until it is completely dissolved, preferably stirring rapidly at room temperature for 10 minutes to achieve complete dissolution.

[0008] In some embodiments that may include the above embodiments, the yellowfin tuna skin gelatin is prepared in the following steps:

[0009] First, the cleaned yellowfin tuna skin was soaked in 0.1 mol / L sodium hydroxide solution (1:10, w / v) at room temperature to remove non-collagen and fat. The skin was stirred continuously during the soaking process for 2 hours, and the sodium hydroxide solution was replaced every 30 minutes. The fish skin after alkali treatment was washed with distilled water until neutral, and then soaked in 0.2 mol / L acetic acid (1:10, w / v) at room temperature and stirred for 12 hours to further remove impurities and fully swell the fish skin. After acid treatment, the skin was washed with distilled water until neutral. After the pH value was adjusted, the mixture was continuously stirred in distilled water (1:10, w / v) at 60°C for 12 hours to extract gelatin. After the extraction was completed, the mixture solution was filtered with two layers of clean gauze, and the filtrate was centrifuged at 10,000 r / min for 10 minutes to remove insoluble impurities. The supernatant was collected, and n-hexane solution was added to the supernatant and mixed to absorb the oil in the gelatin solution. After standing for ten minutes, the mixture was centrifuged at 10,000 r / min for ten minutes, and the lower layer of the supernatant was collected and freeze-dried to obtain the yellowfin tuna skin gelatin sample.

[0010] The nanofiber cling film of the embodiment of the present application, in which anthocyanin and curcumin are compounded, utilizes the antioxidant properties of curcumin to compensate for the instability of anthocyanin, and uses the wide color change range of anthocyanin to supplement the limited color change range of curcumin. Since fish meat is easily corrupted under the combined action of microorganisms and enzymatic reactions, the color change response of its components to the changes in pH value and TVB-N value inside the package can realize real-time monitoring of food freshness.

[0011] In some embodiments that may include the above-mentioned embodiments, the specific process of blow spinning is: transfer the spinning solution to the injection container, use a needle to bend its head to 90° and then install it on the injection pump, adjust the propulsion speed, turn on the air compressor for blowing, adjust the spinning air pressure and receiving distance, and stick a circle of release paper on the receiver for subsequent separation, adjust the receiver speed, control the humidity, and start spinning.

[0012] In some embodiments that may include the above embodiments, the specific conditions for blow spinning are: the injection container is a 5mL syringe, the needle model is 30G, the solution advancement speed is 2mL / h, the spinning gas pressure is 0.020MPa, the receiving distance is 30cm, the receiver speed is 120r / min and the humidity is 10-30%.

[0013] In some embodiments that may include the above embodiments, the mass ratio of yellowfin tuna skin gelatin, chitosan, curcumin, and anthocyanin is 2:0.15:0.032:0.008.

[0014] In some embodiments that may include the above embodiments, the concentration of the yellowfin tuna skin gelatin in the acetic acid solution is 0.2 g / mL; the concentration of the chitosan in the acetic acid solution is 0.015 g / mL; the concentration of the curcumin in the acetic acid solution is 0.0032 g / mL; and the concentration of the anthocyanin in the acetic acid solution is 0.0008 g / mL.

[0015] In some embodiments, which may include the above embodiments, the volume ratio of acetic acid to water in the acetic acid solution is 3:7.

[0016] The second aspect of the embodiment of the present application further provides a nanofiber cling film, which is prepared by the above method.

[0017] The third aspect of the embodiment of the present application further provides a product for preserving tuna meat, comprising the above-mentioned nanofiber preservative film.

[0018] A fourth aspect of the embodiments of the present application also provides the use of the above-mentioned product for preserving tuna meat in preserving tuna meat.

[0019] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0020] (1) The preparation method of the present application has mild reaction conditions, short preparation time, simple operation and easy control.

[0021] (2) The nanofiber cling film of the present application adopts a compounding method of anthocyanin and curcumin, and utilizes the antioxidant property of curcumin to compensate for the instability of anthocyanin, and the wide color change range of anthocyanin supplements the limited color change range of curcumin.

[0022] (3) In view of the fact that fish meat is easily corrupted by the combined effects of microorganisms and enzymatic reactions, the nanofiber cling film of the present application can realize real-time monitoring of food freshness by changing color in response to changes in pH value and TVB-N value inside the package through its components.

[0023] (4) The preparation method of the present application does not require high-pressure or high-temperature equipment and is easy to mass-produce. The prepared nanofiber cling film has excellent properties such as good hydrophobicity, antibacterial properties, environmental protection and biodegradability, and can be widely used in the field of food packaging materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 The figures are scanning electron microscope images of nanofiber cling film, wherein Figure (a) is a scanning electron microscope image of the yellowfin tuna skin gelatin / chitosan nanofiber film of Comparative Example 1, and Figure (b) is a scanning electron microscope image of the nanofiber cling film of Example 1;

[0026] Figure 2 : is the contact angle of the nanofiber cling film, wherein Figure (a) is the water contact angle of the yellowfin tuna skin gelatin / chitosan nanofiber film of Comparative Example 1; Figure (b) is the water contact angle of the nanofiber cling film of Example 1;

[0027] Figure 3 The yellowfin tuna skin gelatin / chitosan nanofiber membrane of comparative example 1 and the nanofiber cling film of example 1 are performance diagrams for inhibiting Escherichia coli (E.coil) and Staphylococcus aureus (S.aureus);

[0028] Figure 4 This is the color development diagram at different pH values ​​after curcumin and anthocyanin were mixed in a ratio of 8:2. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.

[0031] In the following examples and comparative examples, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods.

[0032] In the following examples and comparative examples, the preparation process of yellowfin tuna skin gelatin is as follows: first, the cleaned yellowfin tuna skin is immersed in a 0.1 mol / L sodium hydroxide solution (1:10, w / v) at room temperature to remove non-collagen and fat, and the skin is continuously stirred during the immersion process. The skin is immersed for 2 hours, and the sodium hydroxide solution is replaced every 30 minutes; the fish skin treated with alkali is washed with distilled water until neutral, and then immersed in 0.2 mol / L acetic acid (1:10, w / v) at room temperature and stirred for 12 hours to further remove impurities and allow the fish skin to fully dissolve. swelling; after acid treatment, washing with distilled water to neutral pH, stirring continuously for 12 hours in distilled water (1:10, w / v) at 60°C to extract gelatin; after the extraction is completed, the mixture solution is filtered with two layers of clean gauze, and the filtrate is centrifuged at 10000r / min for 10 minutes to remove insoluble impurities; the supernatant is collected, and n-hexane solution is added to the supernatant to mix well to absorb the oil in the gelatin solution, and after standing for ten minutes, the supernatant is centrifuged at 10000r / min for ten minutes, and the lower layer of the supernatant is collected and freeze-dried to obtain the yellowfin tuna skin gelatin sample.

[0033] Example 1

[0034] The method for preparing the nanofiber cling film in this embodiment comprises the following steps:

[0035] (1) Weigh 2 g of yellowfin tuna skin gelatin and dissolve it in 10 ml of acetic acid-water solution containing 30% (v / v) acetic acid, then add 0.15 g of chitosan, stir evenly, then add 0.032 g of curcumin and 0.008 g of anthocyanidin, stir until completely dissolved to obtain a spinning solution.

[0036] (2) The prepared spinning solution was transferred to a 5 mL syringe, and a 30G needle was used. The needle head was bent into 90° and installed on the syringe pump. The propulsion speed was adjusted to 2 mL / h. The air compressor was turned on for blowing, and the spinning pressure was adjusted to 0.020 MPa. The receiving distance was adjusted to 30 cm, and a release paper was pasted on the receiver for subsequent separation. The receiver speed was adjusted to 120 r / min. The humidity was controlled at 10-30%, and the temperature was 25°C. Spinning was started, and the solution was sprayed for 2.5 h. Then the air flow was adjusted to 0 MPa. The syringe pump was turned off and the spinning was stopped to obtain a nanofiber cling film.

[0037] Comparative Example 1

[0038] The method for preparing the nanofiber membrane in this comparative example comprises the following steps:

[0039] (1) Weigh 2 g of yellowfin tuna skin gelatin and dissolve it in 10 ml of acetic acid-water solution containing 30% (v / v) acetic acid, then add 0.15 g of chitosan and stir until it is completely dissolved to obtain the spinning solution.

[0040] (2) The prepared spinning solution was transferred to a 5 mL syringe, and a 30G needle was used. The needle head was bent into 90° and installed on the syringe pump. The propulsion speed was adjusted to 2 mL / h. The air compressor was turned on for blowing, and the spinning pressure was adjusted to 0.020 MPa. The receiving distance was adjusted to 30 cm, and a release paper was pasted on the receiver for a circle to facilitate subsequent separation. The receiver speed was adjusted to 120 r / min. At the same time, the humidity was controlled to 10-30%, and the temperature was 25°C. Spinning was started, and the solution was sprayed for 2.5 h. Then the air flow was adjusted to 0 MPa. The syringe pump was turned off and spinning was stopped to obtain a gelatin / chitosan nanofiber membrane.

[0041] Test Example 1

[0042] The surface morphology of the gelatin / chitosan nanofiber membrane of Comparative Example 1 and the nanofiber cling film of Example 1 were analyzed using a scanning electron microscope. Figure 1 As shown, (a) is a scanning electron microscope image of the yellowfin tuna skin gelatin / chitosan nanofiber membrane of comparative example 1, and (b) is a scanning electron microscope image of the nanofiber cling film of example 1. The results show that the fiber diameter of the nanofiber cling film of example 1 is larger than that of the yellowfin tuna skin gelatin / chitosan nanofiber membrane of comparative example 1 at the same magnification, and the fibers are continuous and evenly distributed.

[0043] Test Example 2

[0044] Water contact angle test: Three 1.0 cm × 1.0 cm samples of each of the yellowfin tuna skin gelatin / chitosan nanofiber film of Comparative Example 1 and the nanofiber cling film of Example 1 were placed on a test plate, and a contact angle test was performed using an interfacial tension analyzer. Subsequently, 0.005 volume parts of distilled water were gently dropped on the surface of the film, and the contact angle change within 2 seconds after the water was dropped was measured using a video monitor, and pictures with representative changes were selected to determine the wettability of the samples. The results are shown in FIG. Figure 2 As shown, (a) is the water contact angle of the yellowfin tuna skin gelatin / chitosan nanofiber membrane of Comparative Example 1, and (b) is the water contact angle of the nanofiber cling film of Example 1. The results show that the hydrophobicity of the gelatin / chitosan nanofiber membrane of Comparative Example 1 is significantly lower than that of the nanofiber cling film of Example 1, wherein the contact angle of the gelatin / chitosan nanofiber membrane of Comparative Example 1 is 87.5°, while the contact angle of the nanofiber cling film of Example 1 is 99°, and the contact angle has changed, so the nanofiber cling film of Example 1 has excellent hydrophobic properties.

[0045] Test Example 3

[0046] The gelatin / chitosan nanofiber membrane of comparative example 1 and the nanofiber cling film of example 1 were tested for their inhibition of Escherichia coli and Staphylococcus aureus: 10 mg of the yellowfin tuna skin gelatin / chitosan nanofiber membrane of comparative example 1 and the nanofiber cling film of example 1 were dissolved in 400 ul of saline solution and 100 ul of 108 CFU / ml bacterial solution, and the mixture was fully reacted for at least 30 minutes. After the reaction, 500 ul of saline solution was added, and the mixture was diluted to 103 CFU / ml in turn. After the dilution was completed, 500 ul was taken for coating. After the coating was completed, the antibacterial effect was analyzed by counting the number of colonies. The results are shown in Table 1. Figure 3 (The blank control in the figure is: no film is added, and other treatment conditions are the same.) The antibacterial results show that the colony counts of Escherichia coli and Staphylococcus aureus in the nanofiber cling film of Example 1 are significantly reduced compared with the yellowfin tuna skin gelatin / chitosan nanofiber membrane of Comparative Example 1. The results show that the nanofiber cling film of Example 1 has a good antibacterial effect.

[0047] Test Example 4

[0048] The color reaction of curcumin / anthocyanidin mixed in a ratio of 8:2 at different pH values ​​(pH 5-10). Figure 4 As shown, under different pH conditions, the solution color showed obvious differences, so loading curcumin / anthocyanidins onto gelatin / chitosan nanofiber membranes can monitor the freshness of fish meat at different stages.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a nanofiber cling film, characterized in that: The following steps are involved: Firstly, yellowfin tuna skin gelatin is dissolved in an acetic acid solution, and chitosan is added after the yellowfin tuna skin gelatin is completely dissolved, and the mixture is stirred evenly to obtain a yellowfin tuna skin gelatin / chitosan blended solution; then, anthocyanin and curcumin are added to the yellowfin tuna skin gelatin / chitosan blended solution, and the mixture is stirred evenly to obtain a spinning solution; The spinning solution is blown and spun, and the nanofiber cling film is obtained by collecting it with release paper.

2. The method for preparing the nanofiber cling film according to claim 1, characterized in that: The preparation process of the yellowfin tuna skin gelatin is as follows: First, the cleaned yellowfin tuna skin is soaked in a 0.1 mol / L sodium hydroxide solution at room temperature to remove non-collagen and fat. The skin needs to be stirred continuously during the soaking process for 2 hours, and the sodium hydroxide solution is replaced every 30 minutes. The fish skin treated with alkali is washed with distilled water until neutral, and then soaked with 0.2 mol / L acetic acid at room temperature and stirred for 12 hours to further remove impurities and fully swell the fish skin. After acid treatment, the skin is washed with distilled water to a neutral pH, and then continuously stirred in distilled water at 60°C for 12 hours to extract gelatin. After the extraction is completed, the mixture solution is filtered through two layers of clean gauze, and the filtrate is centrifuged at 10000r / min for 10 minutes to remove insoluble impurities; The supernatant was collected, and n-hexane solution was added to the supernatant and mixed to absorb the oil in the gelatin solution. After standing for ten minutes, the mixture was centrifuged at 10,000 r / min for ten minutes, and the lower clear liquid was collected and freeze-dried to obtain a yellowfin tuna skin gelatin sample.

3. The method for preparing the nanofiber cling film according to claim 1, characterized in that: The specific process of blow spinning is: transfer the spinning solution to the injection container, use a needle to bend its head to 90 degrees and then install it on the injection pump, adjust the propulsion speed, turn on the air compressor for blowing, adjust the spinning air pressure and receiving distance, and stick a circle of release paper on the receiver for subsequent separation, adjust the receiver speed, control the humidity, and start spinning.

4. The method for preparing the nanofiber cling film according to claim 3, characterized in that: The specific conditions of the blow spinning are: the injection container is a 5mL syringe, the needle model is 30G, the solution advancement speed is 2mL / h, the spinning air pressure is 0.020MPa, the receiving distance is 30cm, the receiver speed is 120r / min and the humidity is 10-30%.

5. The method for preparing the nanofiber cling film according to claim 1, characterized in that: The mass ratio of the yellowfin tuna skin gelatin, chitosan, curcumin and anthocyanin is 2:0.15:0.032:0.

008.

6. The method for preparing the nanofiber cling film according to claim 1, characterized in that: The concentration of the yellowfin tuna skin gelatin in the acetic acid solution is 0.2 g / mL; the concentration of the chitosan in the acetic acid solution is 0.015 g / mL; the concentration of the curcumin in the acetic acid solution is 0.0032 g / mL; and the concentration of the anthocyanin in the acetic acid solution is 0.0008 g / mL.

7. The method for preparing the nanofiber cling film according to claim 1, characterized in that: The volume ratio of acetic acid to water in the acetic acid solution is 3:

7.

8. A nanofiber cling film, characterized in that: The method according to any one of claims 1 to 7 is used to prepare the present invention.

9. A product for preserving tuna meat, characterized in that: Including the nanofiber cling film as described in claim 8.

10. Use of the product for preserving tuna meat according to claim 9 in preserving tuna meat.

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