Multifunctional collagen-based edible food packaging film with pH responsiveness and preparation
By adding Ganoderma lucidum mycelium and grape skin red pigment to collagen-based films, a multifunctional food packaging material with pH responsiveness was prepared, solving the problems of food preservation and petroleum-based material processing, and achieving efficient preservation and dynamic monitoring effects.
Patent Information
- Application Number
- CN202411868704.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2026-02-03
AI Technical Summary
Existing food packaging materials are inadequate in terms of preservation and dynamic monitoring, and the processing issues of petroleum-based materials have not been effectively resolved.
A collagen-based film is used, with the addition of Ganoderma lucidum mycelium and grape skin red pigment to form a pH-responsive multifunctional film. Combining antioxidant and antibacterial properties, it enables the preservation and dynamic monitoring of food.
It achieves efficient food preservation, dynamic monitoring, and improves mechanical properties and antioxidant capacity, while reducing the environmental impact of petroleum-based materials.
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Figure CN121449934A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of biodegradable packaging materials, more particularly, relates to a multifunctional collagen-based edible food packaging film with pH responsiveness and preparation, especially to a biodegradable natural food packaging film with pH responsiveness and a preparation method. BACKGROUND
[0002] In the food packaging industry, biodegradable polymers will replace fossil-based polymers due to less harm to the environment. Collagen is a protein obtained from animal skin, tendons and various connective tissues, which has been widely used in the fields of environment, food, medicine and the like due to its biocompatibility, biodegradability and non-toxicity. At the same time, collagen can self-assemble to form a film with high surface uniformity and flexibility, but there are still limitations in food preservation packaging applications.
[0003] Existing packaging materials are mainly prepared from polyethylene, polypropylene and the like, which have moderate oxygen permeability and moisture permeability, as well as good tensile strength. However, in practical applications, the preservation of food is still affected by external factors such as air. At present, people's living conditions and quality are increasing, and there are still problems in the treatment of waste polymer packaging materials, such as degradation and recycling. Therefore, biodegradable natural materials have become a new research topic in the food field. SUMMARY
[0004] To solve the technical problems of food preservation and the inability of petroleum-based packaging materials to indicate the freshness of packaged food, the present application provides a multifunctional collagen-based food packaging material with pH responsiveness, which adds grape skin red pigment with pH responsiveness to the film formed by ganoderma lucidum mycelium and collagen. The food packaging film designed in the present application has pH responsiveness, antioxidant property, antibacterial property and high mechanical property. The film will change from pink to yellow with the change of environmental pH from acidic to alkaline, realizing the preservation and dynamic monitoring of food materials.
[0005] According to the first aspect of the present application, a preparation method of a multifunctional collagen-based edible food packaging film with pH responsiveness is provided, comprising the following steps:
[0006] (1) Swell the collagen to obtain a collagen suspension, then mix it with grape skin red pigment with pH responsiveness to obtain a collagen mixture;
[0007] (2) Add ganoderma lucidum mycelium liquid to the collagen mixture obtained in step (1), pour into a mold, and dry to obtain a multifunctional collagen-based edible food packaging film with pH responsiveness.
[0008] Preferably, the collagen is extracted from the tendon or connective tissue of an animal, or the collagen is extracted from the skin of an animal.
[0009] Preferably, the collagen is extracted from the tendon or connective tissue of an animal, or the collagen is extracted from the skin of an animal.
[0010] Preferably, in step (1), the concentration of the collagen suspension is 3 mg / mL-10 mg / mL.
[0011] Preferably, the solvent of the collagen suspension is water, an aqueous acetic acid solution, or an aqueous sodium hydroxide solution.
[0012] Preferably, the concentration of the grape skin red pigment in the collagen mixture is 0.5 mg / mL-2 mg / mL.
[0013] Preferably, in step (2), the concentration of the Ganoderma lucidum mycelium solution is 0.5 mg / mL-5 mg / mL.
[0014] Preferably, in step (2), the mass ratio of the Ganoderma lucidum mycelium in the Ganoderma lucidum mycelium solution, the grape skin red pigment, and the collagen in the collagen mixture is 1:(0.3-1):(7-25).
[0015] Preferably, in step (2), the Ganoderma lucidum mycelium solution is added to the collagen mixture, and then glycerol is added.
[0016] Preferably, the amount of glycerol added is 10%-20% of the total mass of the Ganoderma lucidum mycelium in the Ganoderma lucidum mycelium solution and the collagen in the collagen mixture.
[0017] According to another aspect of the present application, a prepared pH-responsive multifunctional collagen-based edible food packaging film is provided.
[0018] Preferably, the food packaging film has a form of a sheet film, a casing, or a tubular film.
[0019] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:
[0020] (1) The food film designed by the present application has pH responsiveness, antioxidant properties, antibacterial properties, and high mechanical properties. The film will change from pink to yellow with changes in the environmental pH from acidic to alkaline, achieving preservation and dynamic monitoring of food materials.
[0021] (2) Collagen is a natural polymer with a triple helix structure, with intermolecular and intramolecular hydrogen bonds. At the same time, because of its biocompatibility, biodegradability, non-toxicity and film-forming property, it becomes a new raw material to replace petroleum-based packaging materials. Ganoderma lucidum mycelium also has several effective components as a natural raw material. Mainly including the following categories, such as proteins, polysaccharides, nucleotides, alkaloids, furan derivatives, triterpenes and other compounds. It has a wide range of pharmacological effects and extremely low toxicity, such as anti-tumor, immunomodulation, sedation, strong heart and anti-myocardial ischemia, blood lipid regulation, asthma, liver protection, blood sugar reduction, anti-hypoxia and free radical clearance, antibacterial and anti-aging. The collagen protein composite film of the present application has high mechanical strength, its tensile strength is 1.5-2 times higher than that of pure collagen protein film; good thermal stability, the maximum thermal weight loss rate is 1.8-2.2 times lower than that of pure collagen protein film; high antibacterial activity, its antibacterial rate is 3.5-5 times higher than that of pure collagen protein film; antioxidant properties, ABTS free radical clearance rate is increased by 3.8-9.8 times, DPPH free radical clearance rate is increased by 3.55-8.73 times, water vapor barrier property is reduced by 1.2-2 times, surface uniformity and other advantages. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 The UV absorption spectrum of grape skin red pigment with pH responsiveness.
[0023] Figure 2 The actual picture of collagen protein-based film with pH responsiveness.
[0024] Figure 3 The color change schematic diagram of collagen protein-based film with pH responsiveness when the pH changes.
[0025] Figure 4 The scanning electron microscope test diagram of collagen protein film.
[0026] Figure 5 The mechanical strength result diagram of collagen protein-based film with pH responsiveness.
[0027] Figure 6 The water vapor permeability test diagram of collagen protein film.
[0028] Figure 7 The thermogravimetric test diagram of collagen protein film.
[0029] Figure 8 The antioxidant performance test diagram of collagen protein film.
[0030] Figure 9 The antibacterial performance test diagram of collagen protein film.
[0031] Figure 10 The strawberry preservation application diagram of collagen protein film.
[0032] Figure 11 Figure 1 shows the picture of the collagen film decay response diagram.
[0033] Figure 1 shows the picture of the collagen film decay response diagram. DETAILED DESCRIPTION
[0034] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.
[0035] The collagen-based composite film is a multifunctional packaging material. The addition of ganoderma lucidum mycelium mainly relies on the unique functional properties of ganoderma lucidum, such as antibacterial and antioxidant properties. Grape skin red pigment is used as a pH sensitive agent to prepare multifunctional packaging materials with antibacterial properties, antioxidant properties, high tensile strength and pH response.
[0036] The purpose of the present application is to provide a preparation method of a natural composite film with pH response, antibacterial properties, antioxidant properties and strong tensile strength. It includes the preparation of pH-responsive collagen stock solution and the mixing of ganoderma lucidum mycelium culture into film process. The steps are as follows:
[0037] (1) Preparation of collagen precursor solution: The collagen extracted from cowhide is dispersed in the solvent in proportion, and is placed in a magnetic stirrer after swelling. It is uniformly stirred at low temperature to obtain a collagen suspension, and is mixed with grape skin red pigment with pH response in a certain proportion, as shown in Figure 1 The grape skin red pigment has different ultraviolet absorption under different pH conditions and has shown different colors under different pH conditions. Finally, the collagen mixed solution is prepared and stored in a 4℃ refrigerator;
[0038] (2) Cultivation and preparation of ganoderma lucidum mycelium: The uniform ganoderma lucidum mycelium ball is prepared by adjusting the conditions of potato culture medium of ganoderma lucidum mycelium. The mycelium ball is centrifuged and washed with water, and is homogenized to obtain a mycelium solution with a certain concentration;
[0039] (3) Preparation of pH-responsive collagen-based composite film: the Ganoderma lucidum mycelium liquid in step (2) is added into the collagen mixture obtained in step (1) at a certain ratio, and stirred uniformly at low temperature, and then placed at 37°C for drying after standing for a period of time to form a gel, thereby preparing a collagen-based composite film with pH response.
[0040] In order to optimize the above technical solutions, the specific methods adopted include the following:
[0041] In step (1), the collagen concentration is selected to be 3 mg / mL-30 mg / mL, and most preferably 3 mg / mL-10 mg / mL; the solvent is selected to be one of ultrapure water, acetic acid solution, and sodium hydroxide solution; and the swelling time is selected to be 12 hours-72 hours. The low-temperature stirring is performed for 12 hours-36 hours, and then the grape skin red pigment with pH response in step (1) is added, and the content is selected to be 0.5 mg / mL-2 mg / mL, and most preferably 0.75 mg / mL, thereby obtaining a collagen suspension.
[0042] In step (2), the concentration of the mycelium liquid after the final homogenization is selected to be 0.5 mg / mL-5 mg / mL, and most preferably 2.6 mg / mL.
[0043] In step (3), the mass ratio of Ganoderma lucidum mycelium in the mycelium liquid to collagen in the collagen mixture is 1:(7-25), and most preferably 1:10.
[0044] The following are specific examples
[0045] Example 1
[0046] S1, accurately weigh 1.5 g of bovine skin extracted collagen, and dissolve it in 30 mL of ultrapure water to prepare a bovine skin extracted collagen precursor solution with a concentration of 6 mg / mL; dissolve 22 mg of grape skin red pigment in water, and uniformly mix it with the bovine skin extracted collagen at a mass ratio of 1:9 to obtain a final collagen and grape skin red pigment pre-gel solution, which is stored at low temperature.
[0047] S2, transfer the Ganoderma lucidum mycelium seed in the PDA solid culture medium to the PDA liquid culture medium at a certain ratio, and culture until the mycelium grows uniformly, then homogenize it in a homogenizer to prepare a 10 mg / mL Ganoderma lucidum mycelium liquid.
[0048] S3, add 10.4 mL of the Ganoderma lucidum mycelium liquid with a concentration of 10 mg / mL in S2 dropwise to the collagen pre-gel solution in S1, stir uniformly, then add 10% of the solid mass of the collagen and Ganoderma lucidum mycelium mixture glycerol, continue stirring for 3-5 minutes, stand for a period of time to self-assemble into a gel, and place at 37°C for drying, thereby obtaining different collagen composite films as shown in Figure 2 , wherein Figure 3As shown, the collagen composite film CRE4 exhibits different colors under different pH conditions. The collagen-based composite film presents a pink purple color, which eventually changes to magenta as the pH decreases or first changes to green and then to yellow as the pH increases, showing a color change visible to the naked eye, which facilitates naked-eye detection. Thus, the pH response characteristics are verified.
[0049] In Example 1, the collagen composite film is composed of 53.57% collagen, 6.55% grape skin red pigment, 30.95% ganoderma hyphae, and 8.93% glycerol by weight. The surface and cross-section of the prepared composite film were characterized by SEM scanning electron microscopy (as shown in Figure 4 ), the surface morphology of the composite film after adding ganoderma hyphae (C) is more uniform than that of the pure collagen film (A), and the cross-section is more compact. The performance of the composite film, such as mechanical properties Figure 5 ), water vapor barrier properties Figure 6 ), thermal stability Figure 7 ), antioxidant properties Figure 8 ), antibacterial properties Figure 9 ), preservation properties Figure 10 ), and pH response characteristics Figure 11 ) were characterized. From Figure 5 , the growth of E. coli was observed, and compared with the blank pure bacterial solution, the antibacterial effect of the collagen film was not obvious, the addition of hyphae (CE), grape skin red pigment (CR), and the composite film (CRE) all showed obvious inhibition effect on E. coli. From Figure 8 , the change of ABTS free radical scavenging rate was obvious, and compared with the antioxidant properties of the pure collagen film, the composite film added with ganoderma hyphae and grape skin red pigment had higher antioxidant properties. According to the research, ganoderma hyphae itself contains extracellular polysaccharides, triterpenoids, and other substances with good antioxidant properties. From Figure 5 , the change of mechanical properties was studied, and compared with the tensile strength (TS) and elongation at break (EAB) of the pure collagen film, the composite film added with ganoderma hyphae and grape skin red pigment was correspondingly improved. In addition, the water vapor barrier properties were improved by 1.68 times Figure 6 , the thermal decomposition rate was reduced by about 2 times Figure 7 , and the results in food preservation applications Figure 10 indicated that, compared with the pure collagen film, the preservation of strawberries was prolonged from 5 days to 13 days, and the film showed the pH response characteristics Figure 11 from red-brown to blue-violet color before and after the fish slices deteriorated.
[0050] Example 2
[0051] S1, accurately weigh 1.5 g of bovine skin extracted collagen, dissolve thoroughly in 30 mL of ultrapure water to prepare a collagen precursor solution with a concentration of 6 mg / mL; dissolve 22 mg of grape skin red pigment in water, uniformly mix with collagen in a mass ratio of 1:9 to obtain a final collagen and grape skin red pigment pre-gel solution, and store at low temperature.
[0052] S2, transfer the Ganoderma lucidum mycelium seed in the PDA solid culture medium to the PDA liquid culture medium at a certain ratio, and culture until the mycelium grows uniformly, then homogenize in a homogenizer to prepare a Ganoderma lucidum mycelium solution with a concentration of 10 mg / mL.
[0053] S3, add 5.6 mL of the Ganoderma lucidum mycelium solution with a concentration of 10 mg / mL in S2 dropwise to the collagen pre-gel solution in S1, add 10% of glycerol based on the solid mass of the collagen and Ganoderma lucidum mycelium mixture, stir uniformly, continue stirring for 3-5 minutes, stand for a period of time to self-assemble into a gel, place at 37°C for drying, and obtain a collagen-based composite film CRE2 with pH responsiveness.
[0054] In Example 2, the collagen composite film is composed of 64.94% collagen, 9.93% grape skin red pigment, 18.3% Ganoderma lucidum mycelium, and 9.1% glycerol by weight percentage. The performance of the composite film, including mechanical properties ( Figure 5 ), water vapor barrier properties ( Figure 6 ), thermal stability ( Figure 7 ), and antioxidant properties ( Figure 8 ), is characterized respectively. From the change in ABTS free radical scavenging rate in Figure 8 , it is obvious that the antioxidant properties of the composite film CRE2 with added Ganoderma lucidum mycelium and grape skin red pigment are higher than those of the pure collagen film C, and the antioxidant properties of the CRE film are 8.2 times higher than those of the pure collagen film C. From the study of the change in mechanical properties in Figure 5 , compared with the tensile strength (TS) and elongation at break (EAB) of the pure collagen film, the composite film with added Ganoderma lucidum mycelium and grape skin red pigment is correspondingly improved, and the tensile strength of the CRE2 film is 1.73 times higher than that of the pure collagen film C. In addition, the water vapor barrier properties are improved by 1.31 times ( Figure 6 ), and the thermal decomposition rate is reduced by about 1.57 times ( Figure 7 ).
[0055] Example 3
[0056] S1, accurately weigh 1.5 g of bovine skin extracted collagen, dissolve in 30 mL ultrapure water to prepare a collagen precursor solution with a concentration of 6 mg / mL; dissolve 22 mg of grape skin red pigment in water, uniformly mix with collagen in a mass ratio of 1:9 to obtain a final collagen and grape skin red pigment pre-gel solution, and store at low temperature.
[0057] S2, the Ganoderma lucidum mycelium seed in the PDA solid culture medium was transferred to the PDA liquid culture medium at a certain proportion, and then the mycelium was homogenized in a homogenizer after uniform growth to prepare a Ganoderma lucidum mycelium solution with a concentration of 10 mg / mL.
[0058] S3, 20 mL of the Ganoderma lucidum mycelium solution with a concentration of 10 mg / mL in S2 was added dropwise to the collagen pre-gel solution in S1, 10% of glycerol based on the solid mass of the collagen and Ganoderma lucidum mycelium mixture was added dropwise after uniform stirring, and the mixture was continuously stirred for 3-5 minutes, then left to stand for a period of time to self-assemble into a gel, and then placed at 37°C for drying to obtain a collagen-based composite film CRE5 with pH responsiveness.
[0059] In Example 3, the collagen composite film was composed of 40.7% collagen, 4.97% grape skin red pigment, 45.23% Ganoderma lucidum mycelium, and 9.1% glycerol. The performance of the composite film, including mechanical properties ( Figure 5 ), water vapor barrier properties ( Figure 6 ), thermal stability ( Figure 7 ), and antioxidant properties ( Figure 8 ), was characterized. From the change in ABTS free radical scavenging rate in Figure 8 , it can be seen that the antioxidant properties of the composite film CRE2 with added Ganoderma lucidum mycelium and grape skin red pigment are higher than those of the pure collagen film C, and the antioxidant properties of the CRE5 film are 9.6 times higher than those of the pure collagen film C. From the change in mechanical properties in Figure 5 , the tensile strength (TS) and elongation at break (EAB) of the pure collagen film were compared, and the composite film with added Ganoderma lucidum mycelium and grape skin red pigment correspondingly improved, and the tensile strength of the CRE5 film was about 1.96 times higher than that of the pure collagen film C. In addition, the water vapor barrier properties were improved by 1.83 times ( Figure 6 ), and the thermal decomposition rate was reduced by about 2.2 times ( Figure 7 ).
[0060] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing a pH-responsive multifunctional collagen-based edible food packaging film, characterized in that, Includes the following steps: (1) The collagen was swollen to obtain a collagen suspension, and then mixed with a grape skin red pigment that is pH responsive to obtain a collagen mixture. (2) Add Ganoderma lucidum mycelium liquid to the collagen mixture obtained in step (1), pour it into a mold, and after drying, you will get a pH-responsive multifunctional collagen-based edible food packaging film.
2. The method for preparing the pH-responsive multifunctional collagen-based edible food packaging film as described in claim 1, characterized in that, The collagen is extracted from animal tendons or connective tissue, or from animal skin.
3. The method for preparing the pH-responsive multifunctional collagen-based edible food packaging film as described in claim 1, characterized in that, In step (1), the concentration of the collagen suspension is 3 mg / mL-10 mg / mL; Preferably, the solvent for the collagen suspension is water, an aqueous acetic acid solution, or an aqueous sodium hydroxide solution.
4. The method for preparing the pH-responsive multifunctional collagen-based edible food packaging film as described in claim 1, characterized in that, The concentration of grape skin red pigment in the collagen mixture is 0.5 mg / mL to 2 mg / mL.
5. The method for preparing the pH-responsive multifunctional collagen-based edible food packaging film as described in claim 1, characterized in that, In step (2), the concentration of the Ganoderma lucidum mycelium solution is 0.5 mg / mL to 5 mg / mL.
6. The method for preparing the pH-responsive multifunctional collagen-based edible food packaging film as described in claim 1, characterized in that, In step (2), the mass ratio of Ganoderma lucidum mycelium in the Ganoderma lucidum mycelium solution, grape skin red pigment and collagen in the collagen mixture is 1:(0.3-1):(7-25).
7. The method for preparing the pH-responsive multifunctional collagen edible-based food packaging film as described in claim 1, characterized in that, In step (2), after adding Ganoderma lucidum mycelium liquid to collagen mixture, glycerin is added.
8. The method for preparing the pH-responsive multifunctional collagen-based edible food packaging film as described in claim 7, characterized in that, The amount of glycerol added is 10%-20% of the total mass of Ganoderma lucidum mycelium in the Ganoderma lucidum mycelium solution and collagen in the collagen mixture.
9. A pH-responsive multifunctional collagen-based edible food packaging film prepared by any one of claims 1-8.
10. The pH-responsive multifunctional collagen-based edible food packaging film as described in claim 9, characterized in that, The food packaging film is in the form of sheet film, casing, or tubular film.