Mildew-proof antibacterial edible packaging film as well as preparation method and application thereof

Abstract

The invention provides a mildewproof and antibacterial edible packaging film as well as a preparation method and application thereof. The mildewproof and antibacterial edible packaging film comprises soybean protein isolate, carrageenan, pullulan, modified cellulose, a plasticizer, a reinforcing agent and a preservative. According to the application, a six-element synergistic system of modified cellulose, soybean protein isolate, pullulan, carrageenan, lysine and calcium propionate is formed; the modified cellulose is used as a film forming main body, so that the water sensitivity is low and is not easily influenced by environmental temperature and humidity; the soybean protein isolate and the pullulan synergistically provide high barrier property; carrageenan improves the mechanical property and compactness of the film in a blending system; free calcium of calcium propionate provides a bridge effect for crosslinking of protein and carrageenan, and the mechanical property and compact structure of the film are improved; lysine and a blending system can form a'charge-hydrogen bond-hydrophobicity 'multi-synergistic network, so that the mechanical and barrier properties of the film are improved, and meanwhile, the mildew resistance of calcium propionate is coordinated. The film can meet the packaging of superfine powder materials, and is applied to the extreme temperature and humidity environment with the temperature ranging from-20 DEG C to 50 DEG C and the RH ranging from 30% to 95%.

Description

Technical Field

[0001] This application belongs to the field of packaging technology, and in particular relates to an anti-mildew and antibacterial edible packaging film, its preparation method and application. Background Technology

[0002] Edible films typically use proteins, polysaccharides, and lipids as their main materials. Protein and polysaccharide films offer high mechanical strength, while lipid-based films, due to their lower mechanical properties, cannot form films and are usually blended with other substances. Currently, most edible film materials are hydrophilic, leading to moisture migration issues. In extreme temperature and humidity conditions, such as very dry or very humid environments, the films are prone to cracking or becoming damp, hindering their widespread use. Besides environmental factors, edible films also have specific requirements for the packaged material. When packaging ultrafine powders, the large surface area of ​​these powders makes them highly susceptible to absorbing moisture. This can cause the film to crack and the powder to become deliquescent, further limiting the widespread use of edible film materials. Summary of the Invention

[0003] This application is made in view of the above-mentioned issues, and its purpose is to provide an edible packaging film with anti-mildew and antibacterial properties, a preparation method thereof, and an application thereof. The prepared film material can meet the requirements for packaging ultrafine powder materials and can be applied to extreme temperature and humidity conditions in daily environments, such as temperature -20~50℃ and humidity 30%~95%.

[0004] The first aspect of this application provides an edible packaging film that is mildew-proof and antibacterial, comprising the following components in parts by weight: 2-10 parts soy protein isolate, 0.5-5 parts carrageenan, 0.5-5 parts pullulan, 5-15 parts modified cellulose, 4-11 parts plasticizer, 0.001-0.1 parts reinforcing agent, and 0.002-0.1 parts preservative.

[0005] In any embodiment, the plasticizer is at least one of oleic acid, linoleic acid, and sorbitol; the reinforcing agent is lysine; and the preservative is calcium propionate.

[0006] In any embodiment, the modified cellulose is one or more of cellulose acetate, hydroxypropyl methylcellulose, microcrystalline cellulose, and carboxymethyl cellulose.

[0007] In any embodiment, the plasticizer is a blend of oleic acid, linoleic acid, and sorbitol in a weight ratio of 1~3:2~5:1~3.

[0008] In any embodiment, the soy protein isolate has a molecular weight distribution of 50-100D; the carrageenan is type I carrageenan with a mesh size of 80-200 mesh.

[0009] In any embodiment, the lysine is one or more of polylysine, ε-polylysine hydrochloride, and D-lysine.

[0010] The second aspect of this application also provides a method for preparing an anti-mildew and antibacterial edible packaging film, comprising the following steps: adding 0.5-5 parts of carrageenan to 100 parts of distilled water, boiling to dissolve, cooling to 55-65°C, and while stirring, successively adding 4-11 parts of plasticizer, 0.001-0.1 parts of lysine and 0.002-0.1 parts of calcium propionate to obtain a carrageenan system; taking 5-15 parts of modified cellulose powder, 2-10 parts of soy protein isolate powder, and 0.5-5 parts of pullulan powder and mixing them together, then adding them to the dissolved carrageenan system and stirring to dissolve, homogenizing at 2000-10000 rpm for 3-10 minutes to disperse evenly, and vacuum degassing at -0.1 MPa for 3-8 minutes; and casting to form a film.

[0011] In any embodiment, the film thickness is 50 μm ± 2.

[0012] The third aspect of this application provides an application of an anti-mildew and antibacterial edible packaging film, including the edible packaging film of the first aspect of this application or the edible packaging film prepared according to the method of the second aspect of this application for material packaging under extreme temperature and humidity conditions, with a temperature of -20~50℃ and a humidity of 30%~95%.

[0013] In any embodiment, the packaging material is an ultrafine powder material.

[0014] The beneficial effects of this application are as follows: This application uses a blend solution of soy protein isolate, carrageenan, pullulan, and modified cellulose, with sorbitol, oleic acid, and linoleic acid as plasticizers, lysine as a reinforcing agent, and calcium propionate as a preservative; forming a six-component synergistic system of modified cellulose + soy protein isolate + pullulan + carrageenan + lysine + calcium propionate; wherein, modified cellulose is used as the film-forming host, and the modified cellulose obtained by replacing some hydroxyl groups with hydrophobic groups such as methoxy and acetyl groups has low sensitivity to moisture and is not easily affected by environmental temperature and humidity; soy protein isolate and pullulan have high barrier properties, and pullulan is a linear polysaccharide that can be intercalated into macromolecules. The porous structure of the substructure system, in synergy with the other components, significantly enhances the high barrier properties of the film. Carrageenan, in the blend system, improves the mechanical properties and density of the film through hydrogen bonding, molecular entanglement, enhanced compatibility, and structural densification. The free calcium ions of the preservative calcium propionate provide a bridging effect for the cross-linking of protein and carrageenan, further improving the mechanical properties and dense structure of the film. The blend system of lysine with soy protein isolate, cellulose, carrageenan, and pullulan can form a multi-synergistic network of "charge-hydrogen bond-hydrophobicity," significantly improving the mechanical and barrier properties of the film. At the same time, lysine has excellent antibacterial properties, which, together with the antifungal properties of calcium propionate, provide antifungal and antibacterial protection for protein and polysaccharide films. Attached Figure Description

[0015] Figure 1 This is a product image of an edible packaging film that is mildew-proof and antibacterial according to this application.

[0016] Figure 2 This is a product image of an edible packaging film that is mildew-proof and antibacterial according to this application. Detailed Implementation

[0017] The following detailed description, with appropriate reference to the accompanying drawings, discloses an embodiment of an anti-mildew and antibacterial edible packaging film, its preparation method, and its application. However, unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of essentially identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of providing a full understanding of this application by those skilled in the art and are not intended to limit the subject matter of the claims.

[0018] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0019] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0020] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0021] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0022] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0023] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0024] In one embodiment of this application, an edible packaging film with anti-mildew and antibacterial properties is provided, comprising the following components in parts by weight: 2-10 parts soy protein isolate, 0.5-5 parts carrageenan, 0.5-5 parts pullulan, 5-15 parts modified cellulose, 4-11 parts plasticizer, 0.001-0.1 parts reinforcing agent, and 0.002-0.1 parts preservative.

[0025] This application uses a blend solution of soy protein isolate with carrageenan, pullulan, and modified cellulose, with sorbitol, oleic acid, and linoleic acid as plasticizers, lysine as a reinforcing agent, and calcium propionate as a preservative. The resulting film material can meet the requirements for packaging ultrafine powder materials and can be used in extreme temperature and humidity conditions in daily environments, such as temperatures of -20 to 50°C and humidity of 30% to 95%.

[0026] In this formulation, modified cellulose is used as the main film-forming component. The modified cellulose, obtained by replacing some hydroxyl groups with hydrophobic groups such as methoxy and acetyl groups, exhibits low sensitivity to moisture and is less affected by environmental temperature and humidity. Soy protein isolate and pullulan possess high barrier properties; pullulan, being a linear polysaccharide, can penetrate the pores of macromolecular structures, and the synergy between the two significantly enhances the film's high barrier properties. Carrageenan, in the blend system, improves the film's mechanical properties and density through hydrogen bonding, molecular entanglement, enhanced compatibility, and structural densification. The free calcium ions of the preservative calcium propionate act as a bridge for the cross-linking of protein and carrageenan, further improving the film's mechanical properties and dense structure. The blend system of lysine with soy protein isolate, cellulose, carrageenan, and pullulan forms a multi-synergistic network of "charge-hydrogen bond-hydrophobicity," significantly improving the film's mechanical and barrier properties. Simultaneously, lysine possesses excellent antibacterial properties, synergistically enhancing the antifungal properties of calcium propionate, providing antifungal and antibacterial protection for the protein and polysaccharide film.

[0027] In some embodiments, the plasticizer is at least one of oleic acid, linoleic acid, and sorbitol; the reinforcing agent is lysine; and the preservative is calcium propionate.

[0028] The dual effects of lysine (antibacterial + cross-linking) and calcium propionate (antifungal + calcium bridge cross-linking) resolve the contradiction of "inability to achieve both antibacterial and strength" in protein membranes by using lysine-calcium propionate as a dual-function additive for antibacterial and cross-linking.

[0029] Oleic acid, as a plasticizer, can significantly improve the flexibility and water vapor barrier properties of edible films. Compared with glycerol, oleic acid maintains good mechanical properties while significantly reducing water vapor permeability. Linoleic acid also has a good plasticizing effect, enhancing the flexibility and extensibility of edible films. Sorbitol is a commonly used plasticizer that effectively improves the flexibility and elongation at break of edible films. It reduces film brittleness by weakening the intermolecular forces between polymer chains. Sorbitol has strong hygroscopic properties, but significantly weaker than glycerol. This property helps maintain the continuity and flexibility of the film. Without the addition of sorbitol and glycerol, the weak hygroscopicity of oleic acid and linoleic acid is insufficient to provide enough moisture to maintain the continuity of the film, leading to brittleness. When oleic acid, linoleic acid, and sorbitol are prepared in a 1:1:1 ratio and homogenized, a more uniform distribution in the film is ensured, balancing flexibility and low moisture permeability.

[0030] According to standard 2760-2024, calcium propionate can be used in soy products, with a usage not exceeding 2.5g / kg.

[0031] In some embodiments, the modified cellulose is one or more of cellulose acetate, hydroxypropyl methylcellulose, microcrystalline cellulose, and carboxymethyl cellulose.

[0032] In some embodiments, the plasticizer is a blend of oleic acid, linoleic acid, and sorbitol in a weight ratio of 1~3:2~5:1~3.

[0033] In some embodiments, the soy protein isolate has a molecular weight distribution of 50-100D; the carrageenan is type I carrageenan with a mesh size of 80-200 mesh.

[0034] Within the molecular weight range of isolated proteins, better dispersibility and film-forming effects are observed; carrageenan exhibits the best solubility and film-forming effects within this range, while lower mesh sizes increase solubility difficulty, and higher mesh sizes increase upstream processing difficulty and cost. In some embodiments, the lysine is one or more of polylysine, ε-polylysine hydrochloride, and D-lysine.

[0035] According to standard 2760-2024, ε-polylysine hydrochloride can be used in soy products, with a usage not exceeding 0.3 g / kg.

[0036] A method for preparing an anti-mildew and antibacterial edible packaging film includes the following steps: adding 0.5-5 parts of carrageenan to 100 parts of distilled water, boiling to dissolve, cooling to 55-65℃, and while stirring, successively adding 4-11 parts of plasticizer, 0.001-0.1 parts of lysine and 0.002-0.1 parts of calcium propionate to obtain a carrageenan system; taking 5-15 parts of modified cellulose powder, 2-10 parts of soy protein isolate powder, and 0.5-5 parts of pullulan powder and mixing them together, then adding them to the dissolved carrageenan system and stirring to dissolve, homogenizing at 2000-10000 rpm for 3-10 minutes to disperse evenly, and vacuum degassing at -0.1 MPa for 3-8 minutes; casting to form a film.

[0037] Too low a rotation speed will result in uneven dispersion, while too high a speed will introduce more air bubbles, increasing the difficulty of degassing. Degassing is effective under this negative pressure, while degassing is insufficient at too low a speed.

[0038] By limiting the dosage of modified cellulose, soy protein isolate, pullulan, and carrageenan to a specific range, significant improvements can be achieved at the lowest dosage within this range. Within this range, the improvement effect is within the beneficial range; exceeding the range will reduce the proportion of other materials used. For example, if soy protein exceeds the range, the usage of other materials decreases, and properties such as mechanical toughness, barrier properties, and moisture sensitivity of the film will significantly decrease. If soy protein isolate is used below the range, mechanical toughness will significantly decrease, affecting continuous processing. If pullulan is used beyond the range, properties such as moisture sensitivity of the film will significantly decrease; below the range, barrier properties will be insufficient. If modified cellulose is used beyond the range, film-forming continuity, mechanical toughness, and barrier properties will be affected; below the range, moisture sensitivity will decrease. If carrageenan is used beyond the range, barrier properties and moisture sensitivity of the film will be affected; below the range, mechanical properties will be significantly affected.

[0039] A six-component synergistic system of modified cellulose, soy protein isolate, pullulan, carrageenan, lysine, and calcium propionate was developed to obtain an edible packaging film with good mechanical strength, good barrier properties, and significant anti-mildew and antibacterial effects.

[0040] Vacuum degassing + gradient cooling casting process (film formation at 60℃) avoids high temperature damage to lysine activity. In some embodiments, the film thickness is 50 μm ± 2.

[0041] The application of an anti-mildew and antibacterial edible packaging film includes the edible packaging film of the first aspect of this application or the edible packaging film prepared according to the method of the second aspect of this application for material packaging under extreme temperature and humidity conditions, with a temperature of -20~50℃ and a humidity of 30%~95%.

[0042] The packaging material is an ultrafine powder material.

[0043] The packaging material is stable across the entire range and is specifically designed for packaging ultrafine powders (such as freeze-dried probiotic powder and ultrafine powder of traditional Chinese medicine).

[0044] Example The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0045] A method for preparing an anti-mildew and antibacterial edible packaging film includes the following steps: Carrageenan is added to 100 parts of distilled water, boiled to dissolve, and then cooled to 60 degrees Celsius. While stirring, a plasticizer, lysine, and propionic acid are added sequentially. Cellulose powder, soy protein isolate powder, and pullulan powder are then mixed and added to the dissolved carrageenan system and stirred until dissolved. The mixture is homogenized at 2000-10000 rpm for 5 minutes to disperse evenly, and then degassed under vacuum at -0.1 MPa for 5 minutes. The film is then cast into a film.

[0046] The modified cellulose, soy protein isolate, pullulan, and carrageenan were mixed in the proportions shown in Table 1 to prepare a film with a thickness of 50 μm ± 2. The tensile strength, water vapor permeability (WVP), and oxygen barrier properties were then evaluated.

[0047] Table 1

[0048] (1) Tensile strength and elongation at break: According to GB / T13022-1991, the prepared membrane is cut into dumbbell-shaped strips using a cutting tool. The thickness and width of the membrane are measured using vernier calipers. The tensile strength and elongation at fracture are measured using a tensile testing machine at a test rate of 40 mm / min.

[0049] (2) Determination of moisture permeability coefficient: The moisture permeability coefficient was determined using the modified ASTM (American Society for Testing and Materials) method, and the unit is (g·mm) / (m·h·kPa).

[0050] (3) Method for determining the moisture absorption rate of thin films: Sample drying: Dry the film sample at 105℃±2℃ to constant weight and record the initial mass W0.

[0051] Humidity exposure: Place the sample in a constant temperature and humidity chamber (common conditions are 25°C, 85% RH, for 24 to 168 hours).

[0052] Weighing calculation: Weigh immediately after taking it out and record the mass W1 after moisture absorption.

[0053] The moisture absorption rate of the film is calculated as [(W1-W0) / W0]*100%.

[0054] Total bacterial count determination: Refer to GB 4789.2-2022, the unit of total bacterial count is CFU / g.

[0055] Mold determination: GB 4789.15-2016.

[0056] The evaluation results of the plasticizer ratio under the formulation in Table 2 are shown in Table 3: Table 2

[0057] Table 3

[0058] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. An edible packaging film with anti-mildew and antibacterial properties, characterized in that, It includes the following components by weight: 2-10 parts soy protein isolate, 0.5-5 parts carrageenan, 0.5-5 parts pullulan, 5-15 parts modified cellulose, 4-11 parts plasticizer, 0.001-0.1 parts reinforcing agent and 0.002-0.1 parts preservative.

2. The edible packaging film according to claim 1, characterized in that, The plasticizer is at least one of oleic acid, linoleic acid, and sorbitol; the reinforcing agent is lysine; and the preservative is calcium propionate.

3. The edible packaging film according to claim 1, characterized in that, The modified cellulose is one or more of cellulose acetate, hydroxypropyl methylcellulose, microcrystalline cellulose, and carboxymethyl cellulose.

4. The edible packaging film according to claim 1, characterized in that, The plasticizer is a blend of oleic acid, linoleic acid, and sorbitol in a weight ratio of 1~3:2~5:1~3.

5. The edible packaging film according to claim 1, characterized in that, The soy protein isolate has a molecular weight distribution of 50-100D; the carrageenan is type I carrageenan with a mesh size of 80-200 mesh.

6. The edible packaging film according to claim 2, characterized in that, The lysine is one or more of polylysine, ε-polylysine hydrochloride, and D-lysine.

7. A method for preparing an edible packaging film with anti-mildew and antibacterial properties, characterized in that, Includes the following steps: Add 0.5-5 parts of carrageenan to 100 parts of distilled water, boil to dissolve, cool to 55-65℃, and while stirring, add 4-11 parts of plasticizer, 0.001-0.1 parts of lysine and 0.002-0.1 parts of calcium propionate to obtain the carrageenan system. Take 5-15 parts of modified cellulose powder, 2-10 parts of soy protein isolate powder, and 0.5-5 parts of pullulan powder, mix them together, add them to the dissolved carrageenan system and stir to dissolve. Homogenize at 2000-10000 rpm for 3-10 minutes to disperse evenly, and degas under vacuum at -0.1 MPa for 3-8 minutes; then cast into a film.

8. The preparation method according to claim 7, characterized in that, The thickness of the film is 50 μm ± 2.

9. The application of an anti-mildew and antibacterial edible packaging film, characterized in that, The edible packaging film included in any one of claims 1 to 6 or the edible packaging film prepared by the method according to any one of claims 7 to 8 is used for material packaging under extreme temperature and humidity conditions, with a temperature of -20 to 50°C and a humidity of 30% to 95%.

10. The application of an anti-mildew and antibacterial edible packaging film, characterized in that, The edible packaging film according to any one of claims 1 to 6 or the edible packaging film prepared by the method according to any one of claims 7 to 8 is used in the packaging of ultrafine powder materials.

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