Konjak ceramic wine bottle opening sealing film and preparation method thereof

Abstract

The invention discloses a konjak ceramic wine bottle opening sealing film and a preparation method thereof, and belongs to the technical field of food contact materials. The invention provides a preparation method of a composite film with antibacterial performance, which comprises the following steps: dissolving gallic acid in water to obtain a film forming system, adding konjac glucomannan, corn starch and Tara gum into the system, stirring, adding glycerol, stirring to obtain a film coating solution, degassing the prepared film coating solution while the film coating solution is hot, and drying to obtain the composite film with antibacterial performance. Immediately and uniformly smearing the membrane liquid on the ceramic bottle opening; the method disclosed by the invention is particularly suitable for an environment-friendly sealing technology of a high-end ceramic wine container, and can be used for replacing a traditional plastic heat shrinkage film and paraffin sealing process.

Description

TECHNICAL FIELD

[0001] The present application relates to a konjac ceramic wine bottle mouth sealing film and a preparation method thereof, belonging to the technical field of food contact materials. BACKGROUND

[0002] With the improvement of global consumers' awareness of food safety and ecological protection, the wine packaging industry is undergoing a profound change from traditional materials to sustainable solutions. As the core component of the packaging system, the performance of the sealing material is directly related to the shelf life of the wine, transportation safety and brand environmental image. However, the current mainstream plastic heat-shrinkable film, metal tin foil and petroleum-based paraffin materials, although they can provide basic sealing function, but their non-degradable, high carbon footprint and potential health risks have formed a sharp contradiction with global circular economy policy and consumers' expectations for green packaging.

[0003] The traditional sealing material has multiple limitations in long-term application: petroleum-based plastics (such as polyethylene, polyvinyl chloride) rely on non-renewable fossil resources and produce a large amount of greenhouse gases during production. More seriously, its non-degradable nature leads to long-term retention in the environment after disposal, forming microplastics through photodegradation or mechanical wear, causing persistent pollution to soil, water and biological chains. In addition, the high temperature conditions required for plastic processing may cause harmful chemical substances to migrate, posing a risk of contaminating the wine.

[0004] The manufacture of tin foil requires a high-energy refining and rolling process, with a significant carbon footprint throughout its life cycle. Although its oxygen barrier performance is excellent, it may undergo electrochemical corrosion in acidic wine, releasing metal ions to interfere with the flavor stability of the wine. At the same time, the tin foil recycling system is not yet perfect, and a large amount of waste material eventually enters the landfill link, exacerbating resource waste.

[0005] Paraffin, as a byproduct of petroleum refining, may contain carcinogens such as polycyclic aromatic hydrocarbons in its composition, posing a migration risk when in contact with wine for a long time, making it difficult to meet modern food contact material safety standards.

[0006] Konjac glucomannan (KGM) molecular chains contain both hydrophobic acetyl groups and hydrophilic hydroxyl groups, which can be adjusted by deacetylation to balance the hydrophilic and hydrophobic levels, forming a film with mechanical strength and thermal stability. Its gel properties give the film self-adaptive sealing ability, which can fit the irregular surface of the ceramic bottle mouth. However, the hydrophilic nature of single KGM film easily absorbs moisture and softens in high humidity environments, significantly reducing its barrier performance.

[0007] Tara gum (TG) is a natural polysaccharide with a unique galactomannan structure, in which mannose and galactose form a stable three-dimensional network. This colloid is a white to slightly yellow powder with excellent cold water swelling and complete solubility above 45°C. The solution exhibits pseudoplastic fluid characteristics with low concentration and high viscosity. Tara gum demonstrates multiple functional advantages in the food industry: it can form an elastic gel network through hydrogen bonding and possesses excellent emulsification stability and water-holding capacity; its wide pH adaptability (4.5-11), heat resistance, and resistance to ionic interference allow it to be stably applied in various product systems such as frozen desserts, meat products, and baked goods, effectively improving texture and extending shelf life. In the daily chemical industry, the thickening and stabilizing properties of tara gum are also commonly used in emulsion and facial mask formulations.

[0008] Corn starch is widely available and inexpensive, but single-starch films have weak mechanical strength and poor water resistance. Furthermore, molecular chain retraction during film formation can lead to insufficient film uniformity. Although performance can be improved through plasticizing or cross-linking modification, traditional modifiers may introduce food safety risks.

[0009] The increasing demands for sustainability in packaging materials are forcing wineries to accelerate the adoption of green technologies. Consumer surveys show that over 70% of consumers are willing to pay a premium for environmentally friendly packaging, driving brands to use biodegradable sealing materials as a differentiating factor. Although bio-based plastics such as polylactic acid (PLA) have entered the market, their poor heat resistance and high cost remain unresolved. The KGM-based composite material developed in this patent, with its advantages of renewable raw materials, low processing energy consumption, and safety compliance, provides a solution for high-end ceramic wine packaging that combines performance and environmental value, and is expected to become a key technological carrier for the green transformation of wine packaging.

[0010] Sustainable innovation in wine packaging is not only a breakthrough in materials science, but also a systematic project of collaborative innovation across the industry chain. KGM-based natural polymer composite materials, through molecular design and process innovation, have successfully balanced the three objectives of sealing performance, environmental friendliness, and economic feasibility, providing the industry with a scalable green technology path. In the future, with continuous optimization of modification technologies and expansion of application scenarios, these materials are expected to lead the food packaging industry into a new era of "zero waste."

[0011] Currently, in the traditional process of sealing bottled or bottled liquids, many packaging methods use corks with plastic jackets. However, storing alcoholic beverages in this way still leads to evaporation, causing the wine to lose its proper flavor after many years of storage. This results in a significant depreciation of the stored alcoholic beverages, affecting the economic interests of collectors.

[0012] Existing technologies also use cork stoppers combined with sealing wax for packaging. This method adheres to the bottle opening, ensuring that the seal is not easily damaged and achieving a long-lasting seal. However, the preparation process of sealing wax is complicated and there is a risk of heavy metal contamination, which can affect the quality of alcoholic beverages. Summary of the Invention

[0013] To address the problems existing in the prior art, this invention provides a film material to replace sealing wax, which uses a bottle stopper / cap in conjunction with an outer film material for sealing, effectively improving the quality of alcoholic beverages.

[0014] To overcome the limitations of traditional materials, natural polymer materials, such as konjac glucomannan (KGM), tara gum, and corn starch, have become the focus of this invention due to their biodegradability, renewability, and biocompatibility. This invention has found that blending KGM, tara gum, and corn starch in a specific ratio significantly increases the viscosity of the film-forming solution, resulting in synergistic optimization of film performance. This allows for coating applications, enabling the film to adhere to the surface of ceramic wine bottles and form a dense film. Furthermore, the raw materials are completely natural and highly biodegradable.

[0015] This invention specifically relates to an edible, biodegradable bottle-sealing material and its preparation method. It is particularly suitable for environmentally friendly sealing technology of high-end ceramic wine containers, and can replace traditional plastic heat-shrink film and paraffin sealing processes.

[0016] To achieve the above objectives, the present invention adopts the following technical solution:

[0017] A method for preparing an environmentally friendly ceramic bottle sealing material includes the following steps:

[0018] (I) Film-forming substrate lamination:

[0019] Place a beaker containing 500ml of pure water in a 90℃ constant-temperature magnetic stirring bath and preheat for 30 minutes to ensure the water temperature reaches above 90℃. First, dissolve 2.5g of gallic acid in the water. Then, add 4.5±0.1g of food-grade purified konjac glucomannan (purity ≥90%), 10g±0.1g of corn starch (purity ≥99%), and 0.5±0.1g of tara gum (purity ≥99%) to the pure water. Maintain a 90℃ water bath environment and continuously stir using a magnetic stirrer (200rpm) for at least 0.5 hours until the coating solution is free of lumps and forms a homogeneous coating solution. Next, add 2.5g±0.1g of food-grade glycerin as a plasticizer and stir for at least 0.5 hours until homogeneous.

[0020] (II) Solution post-treatment:

[0021] The prepared coating solution was placed in an 80℃ ultrasonic cleaner and degassed at 100% power for 20 minutes to completely remove air bubbles from the system.

[0022] (III) Initial coating molding process:

[0023] Substrate pretreatment: Wipe the mouth of the ceramic wine bottle with 75% ethanol to remove dirt;

[0024] Initial coating: While the membrane solution is still warm, use a disposable syringe to draw 10ml and apply it to the cap of the ceramic bottle to be sealed. This involves squeezing the membrane solution from the top of the cap through the syringe, allowing it to flow evenly. Repeat this step twice. For any areas not covered by the membrane solution, use a coating stick to ensure even coating.

[0025] Gradient drying:

[0026] First stage: Curing at room temperature: Let stand in a ventilated environment at 25±1℃ for 1 hour.

[0027] Second stage: Oven curing: Dry in a forced-air oven at 25±1℃ for 24 hours.

[0028] (iv) Secondary coating molding process:

[0029] Based on the dried, initially coated bottle, follow the steps in (III) to coat and dry it again.

[0030] (V) Repair

[0031] Observe whether the film on the bottle is intact and undamaged, and trim away any excess. The final coating thickness should be 0.15mm.

[0032] This invention provides a method for preparing a ceramic bottle sealing film with antibacterial properties, the method comprising the following steps:

[0033] (1) After dissolving gallic acid in water, a film-forming system is obtained. Konjac glucomannan, corn starch, and tarara gum are added to the system and stirred. Then glycerol is added and stirred to prepare a coating solution.

[0034] The amount of gallic acid added is 0-1.0 g / 100 ml, the amount of konjac glucomannan added is 0.3-1.0 g / 100 ml, the amount of corn starch added is 1.0-2.0 g / 100 ml, the amount of tara gum added is 0-0.7 g / 100 ml, and the amount of glycerol added is 0.25-0.75 g / 100 ml. None of the above amounts are 0.

[0035] (2) After the prepared coating solution is degassed while hot, it is immediately poured into a mold to be uniformly cast into a mold. After drying, a ceramic bottle sealing film is prepared.

[0036] In one embodiment of the present invention, in step (1), gallic acid is dissolved in water at a temperature of at least 90°C.

[0037] In one embodiment of the present invention, in step (1), the stirring conditions are: stirring at 85-95°C and 100-300 rpm for 30-60 minutes.

[0038] In one embodiment of the present invention, in step (1), the stirring conditions are: stirring at 90°C and 200 rpm for 30 min.

[0039] In one embodiment of the present invention, in step (2), the degassing method is to use ultrasonic degassing under the following conditions: 75-150W for 10-30min.

[0040] In one embodiment of the present invention, the amount of gallic acid added is 0.5g / 100ml, the amount of konjac glucomannan added is 0.9g / 100ml, the amount of corn starch added is 2.0g / 100ml, the amount of tara gum added is 0.1g / 100ml, and the amount of glycerol added is 0.5g / 100ml.

[0041] In one embodiment of the present invention, the amount of gallic acid added is 0.25g / 100ml, the amount of konjac glucomannan added is 0.9g / 100ml, the amount of corn starch added is 2.0g / 100ml, the amount of tara gum added is 0.1g / 100ml, and the amount of glycerol added is 0.5g / 100ml.

[0042] In one embodiment of the present invention, the amount of gallic acid added is 0.75g / 100ml, the amount of konjac glucomannan added is 0.9g / 100ml, the amount of corn starch added is 2.0g / 100ml, the amount of tara gum added is 0.1g / 100ml, and the amount of glycerol added is 0.5g / 100ml.

[0043] In one embodiment of the present invention, the drying is hot air drying, and the drying conditions are: 20-30°C, 20-24h.

[0044] The present invention also provides a ceramic bottle sealing film prepared by the above preparation method.

[0045] Beneficial effects

[0046] The ceramic bottle sealing film prepared by this invention has the following properties:

[0047] (1) All-natural ingredients: Konjac glucomannan, tarara gum and corn starch are the core raw materials, supplemented with gallic acid and glycerin. All ingredients meet the safety standards for food contact materials, are non-toxic and harmless and can be completely biodegradable.

[0048] (2) Integrated functions: Through molecular design, the sealing, antibacterial and antioxidant functions are synergistic, without the need to add chemical preservatives, ensuring the sensory quality and safety of the wine during long-term storage.

[0049] (3) Process adaptability: The low-temperature coating and gradient drying process is adapted to the heat-sensitive characteristics of ceramic wine bottles, avoiding the potential impact of high-temperature processing on the glaze of the bottle or the flavor of the wine.

[0050] (4) Performance balance:

[0051] Sealing reliability: The high-efficiency adhesion between the membrane layer and the ceramic bottle neck can withstand transportation vibration and temperature fluctuations;

[0052] Barrier properties: The water vapor and oxygen permeability of the composite membrane is significantly lower than that of traditional paraffin sealing layers;

[0053] Degradation controllability: It can achieve rapid and harmless degradation under natural composting conditions, and the degradation cycle is highly matched with the alcohol consumption cycle. Detailed Implementation

[0054] This invention develops a composite sealing wax system, the composition of which includes: food-grade purified konjac glucomannan, corn starch, tara gum, glycerin, purified water, and gallic acid.

[0055] The materials used in the following examples were sourced as follows: Gallic acid, 99% purity, from Shanghai Maclean Biotechnology Co., Ltd.; Konjac glucomannan (KGM), (purity ≥90%), from Hubei Yizhi Konjac Biotechnology Co., Ltd.; Corn starch (purity ≥99%), reagent grade, from Shanghai Maclean Biotechnology Co., Ltd.; Tara gum (purity ≥99%), from Zhengzhou Yuxing Food Additives Co., Ltd.; Glycerol, analytical grade, from Sinopharm Chemical Reagent Co., Ltd.

[0056] The detection methods involved in the following embodiments are as follows:

[0057] Thin film mechanical testing

[0058] The maximum strength and elongation at break of the edible film were tested using a WDW-5 microcomputer-controlled electronic tensile testing machine. The edible film was cut into strips of 10mm × 50mm. The rectangular strips were clamped 10mm at the top and bottom, leaving a 30mm gap in the middle. Testing was performed using Texture Expert software with a movement speed set to 20mm / min.

[0059] Antibacterial test

[0060] First, cut the membrane sample into squares (2×2cm). 2 After irradiating the membrane sample with ultraviolet light for 30 minutes on a clean bench, add 10 mL of bacterial suspension (10 mL of ... 7 The experimental group consisted of test tubes containing CFU / mL of bacteria, while the control group consisted of bacterial suspensions without the membrane. The bacterial suspensions were then incubated at 37°C on a shaker at 60 rpm for 12 h. Subsequently, 100 μL of the treated bacterial suspension was inoculated onto LB agar plates and incubated at 37°C for 24 h. Finally, the bacterial count was performed on the plates to assess the antibacterial properties of the membrane, and the evaluation was performed using the following formula:

[0061]

[0062] Air tightness test of ceramic wine bottle after coating

[0063] While the film solution is still hot, 10 ml is drawn using a disposable syringe and applied to the cap area of ​​the ceramic bottle to be sealed. This involves squeezing the solution from the top of the cap through the syringe, allowing it to flow evenly. This step is repeated twice. For areas not covered with the film solution, a coating rod is used to ensure even coating. The bottle is then placed in a ventilated environment at 25±1℃ for 1 hour, followed by drying in a forced-air oven at 25±1℃ for 24 hours. This process is repeated twice to form a thin film at the bottle opening (the remaining control groups used commercially available packaging). Finally, the airtightness of the bottles covered with the film is tested. Following a modification of GB / T 17344-1998, a 10 mm circular hole is drilled in the bottom of the ceramic bottle. A flexible tube (10 mm outer diameter, 8 mm inner diameter) is inserted into the hole after the film has been applied, and air is introduced at 0.02 MPa. Then, a continuous, unbroken PE plastic wrap is wrapped around the bottle, and the presence or absence of bulging in the plastic wrap is observed to determine the bottle's airtightness.

[0064] Example 1: Preparation of Environmentally Friendly Ceramic Bottle Sealing Material

[0065] The specific steps are as follows:

[0066] (1) Film-forming substrate composite:

[0067] Place a beaker containing 500ml of pure water in a 90℃ constant temperature magnetic stirring bath and preheat for 30 minutes to ensure the pure water temperature reaches above 90℃. First, dissolve 2.5g of gallic acid in 500ml of water. Then, add 4.5g of konjac glucomannan, 10g of corn starch, and 0.5g of tara gum to the gallic acid aqueous solution. Maintain a 90℃ water bath environment and continuously stir with a magnetic stirrer (200rpm) for 0.5h until there are no lumps in the coating solution and a homogeneous coating solution is formed. Then, add 2.5g of glycerol as a plasticizer and stir for another 0.5h (90℃, 200rpm) to prepare the coating solution.

[0068] (2) Solution post-treatment:

[0069] The prepared coating solution was placed in an 80℃ ultrasonic cleaner and degassed at 150W for 20 minutes to completely remove air bubbles from the system.

[0070] (3) Initial coating molding process:

[0071] Substrate pretreatment: Wipe the mouth of the ceramic wine bottle with a 75% (v / v) ethanol aqueous solution to remove dirt;

[0072] Initial coating: While the degassed membrane solution is still warm, use a disposable syringe to draw 10 ml and apply it to the cap of the ceramic bottle to be sealed. This involves squeezing the membrane solution from the top of the cap through the syringe, allowing it to flow evenly. Repeat this step twice. For any areas not covered with membrane solution, use a coating stick to ensure even coating.

[0073] Gradient drying:

[0074] 1) First stage: Curing at room temperature: Let stand in a ventilated environment at 25±1℃ for 1 hour;

[0075] 2) Second stage oven curing: Dry in a forced-air oven at 25±1℃ for 24 hours.

[0076] (4) Secondary coating molding process:

[0077] Based on the dried, initially coated bottle, follow the steps in (3) to coat again and perform two-stage drying.

[0078] (5) Trimming

[0079] Inspect the bottle for the integrity and any damage to the film, and trim away any excess. Ensure the final coating thickness is 0.15 mm. This will be used for subsequent measurements of the bottle's airtightness.

[0080] (6) Membrane material treatment

[0081] After degassing in step (2), immediately use a 20ml syringe to draw 20ml of the degassed coating solution obtained in step (2) and inject it into a 90mm×90mm circular plastic mold, allowing it to be evenly cast to all parts. Dry it in a forced-air oven at 25±1℃ for 24 hours to form a thin film with a thickness of 0.15mm. This film will be used for subsequent measurements of the film's mechanical and antibacterial properties.

[0082] Example 2: Optimization of film-forming materials

[0083] The specific steps are as follows:

[0084] 1. Specifically, the method is the same as in Example 1, except that the amounts of gallic acid, konjac glucomannan, corn starch, and tarara gum added in step (1) are adjusted as follows:

[0085] Group A: Gallic acid 0g, konjac glucomannan 0g, corn starch 10g, tara gum 5g, glycerin 2.5g;

[0086] Group B: Gallic acid 0g, konjac glucomannan 0.5g, corn starch 10g, tara gum 4.5g, glycerin 2.5g;

[0087] Group C: Gallic acid 0g, konjac glucomannan 1.5g, corn starch 10g, tara gum 3.5g, glycerin 2.5g;

[0088] Group D: Gallic acid 0g, konjac glucomannan 2.5g, corn starch 10g, tara gum 2.5g, glycerin 2.5g;

[0089] Group E: Gallic acid 0g, konjac glucomannan 3.5g, corn starch 10g, tara gum 1.5g, glycerin 2.5g;

[0090] Group F: Gallic acid 0g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 2.5g;

[0091] Group G: Gallic acid 0g, konjac glucomannan 5g, corn starch 10g, tara gum 0g, glycerin 2.5g;

[0092] Group H: Gallic acid 0g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 0g;

[0093] Group I: Gallic acid 0g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 1.25g;

[0094] Group J: Gallic acid 0g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 3.75g;

[0095] Group K: Gallic acid 0g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 5g;

[0096] Group L: Gallic acid 1.25g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 2.5g;

[0097] Group M (Example 1): Gallic acid 2.5g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 2.5g;

[0098] Group N: Gallic acid 3.75g, konjac glucomannan 4.5g, corn starch 10g, tara gum 0.5g, glycerin 2.5g;

[0099] Following the method described in Example 1, film-forming gels A, B, C, D, E, F, G, H, I, J, K, L, M, and N were prepared, and then films A, B, C, D, E, F, G, H, I, J, K, L, M, and N were prepared.

[0100] 2. Results of each group's experiments:

[0101] (1) Air tightness test

[0102] The detection method is as follows:

[0103] While the film solution is still hot, 10ml is drawn into the top of the bottle cap using a disposable syringe and injected, allowing the solution to flow evenly. This step is repeated twice. For areas not covered with film solution, a coating rod is used to ensure even coating. The bottle is then placed in a ventilated environment at 25±1℃ for 1 hour, followed by drying in a forced-air oven at 25±1℃ for 24 hours. This process is repeated twice to form a thin film at the bottle opening (the remaining control groups used commercially available packaging). Finally, the airtightness of the bottles covered with the film is tested. Following a modification of GB / T 17344-1998, a 10mm circular hole is drilled in the bottom of the ceramic bottle. A flexible tube (10mm outer diameter, 8mm inner diameter) is inserted into the hole of the coated bottle, and air is introduced at 0.02MPa. Then, a continuous, unbroken PE plastic wrap is wrapped around the bottle, and the presence or absence of bulging in the plastic wrap is observed to determine the bottle's airtightness.

[0104] The optimized M group was used to conduct sealing experiments, and the results are shown in Table 1.

[0105] Table 1: Air tightness test results for different materials

[0106]

[0107] (2) Antibacterial test

[0108] The detection method is as follows:

[0109] (1) First, cut the membrane sample into squares (2×2cm). 2 After irradiating the membrane sample with ultraviolet light for 30 minutes on a clean bench, add 10 mL of bacterial suspension (10 mL of ... 7 The experimental group consisted of test tubes containing CFU / mL, while the control group consisted of bacterial suspensions without a membrane.

[0110] (2) The bacterial suspensions obtained in step (1) for the experimental group and the control group were incubated in a shaker at 37°C and 60 r / min for 12 h. Then, 100 μL of the treated bacterial suspension was inoculated onto LB agar plates and incubated in a 37°C incubator for 24 h. Finally, the number of bacteria on the plates was counted to assess the antibacterial properties of the membrane, and the evaluation was performed using the following formula:

[0111]

[0112] The results are shown in Table 2.

[0113] Table 2: Antibacterial experiments of different membrane materials

[0114]

[0115] (3) Thin film mechanical testing

[0116] The detection method is as follows:

[0117] The maximum strength and elongation at break of the edible film were tested using a WDW-5 microcomputer-controlled electronic tensile testing machine. The edible film was cut into strips of 10mm × 50mm. The rectangular strips were clamped 10mm at the top and bottom, leaving a 30mm gap in the middle. Testing was performed using Texture Expert software with a movement speed set to 20mm / min.

[0118] The maximum intensity results for each group are shown in Table 3 below:

[0119] Table 3: Mechanical tests of different membrane materials

[0120]

[0121]

[0122] The results show:

[0123] The M group material stands out as the only material to simultaneously meet all three core performance indicators due to its reliable airtightness (test results were "good," superior to leaky groups A, B, and C), excellent antibacterial properties (inhibition rates against both types of bacteria exceeding 97%, significantly higher than the 75%-80% of group L and most groups with zero antibacterial activity), and balanced mechanical properties (strength of 26.89 MPa, higher than groups J and K, and elongation of 33.99%, superior to the brittle group H). In contrast, other groups either suffer from air leakage defects (such as group H), lack antibacterial properties (such as group D), or have unbalanced mechanical properties (such as group G being too soft and group H being too brittle). Group M, with its comprehensive advantages, represents the optimal solution in terms of overall performance.

[0124] Comparative Example 1:

[0125] The specific implementation method is the same as group M in Example 2, except that the glycerol is adjusted to be sorbitol, xylitol, and polyethylene glycol respectively. The results show that:

[0126] 1. Sorbitol: Increased molecular chain rigidity leads to increased tensile strength of the film but a significant decrease in elongation at break, exhibiting a tendency for brittle fracture.

[0127] 2. Xylitol: Insufficient plasticizing efficiency, hindered molecular chain slippage, reduced elongation at break, and unstable tensile strength fluctuations.

[0128] 3. Polyethylene glycol: Excessive hydrophilicity causes the molecular chains to loosen, resulting in a significant deterioration in tensile strength, and the elongation at break is reduced due to the weakened plastic deformation capacity.

[0129] Conclusion: Glycerin's unique molecular structure can synergistically improve the toughness and strength of the film. The alternative components (sorbitol, xylitol, polyethylene glycol) all disrupt the mechanical balance and their mechanical properties are not as good as those of group M.

[0130] Comparative Example 2:

[0131] The specific implementation method is the same as group M in Example 2, except that the tarara gum is adjusted to k-carrageenan and λ-carrageenan respectively. The results show:

[0132] 1. k-carrageenan: Insufficient gel network strength, low molecular chain orientation, and significantly reduced film tensile strength; elongation at break shows an abnormal decrease due to loose structure;

[0133] 2. λ-Carrageenan: Its high water solubility weakens the intermolecular forces, resulting in a simultaneous deterioration of tensile strength and elongation at break.

[0134] Conclusion: The molecular orientation ability of tara gum is the key to maintaining the strength-elongation balance of the film, and the mechanical properties of the alternative components (k-carrageenan, λ-carrageenan) are not as good as those of group M.

[0135] Comparative Example 3:

[0136] Specifically, the method is the same as in Example M, except that the corn starch was adjusted to include potato starch, wheat starch, pea starch, tapioca starch, and rice starch. The results show that:

[0137] 1. Potato starch: High amylose content leads to an increase in crystalline regions, which improves tensile strength but causes a sharp drop in elongation at break, resulting in brittle film breakage.

[0138] 2. Wheat starch: The proportion of branched structure is too high, the molecular chain entanglement is insufficient, and the tensile strength and elongation at break are both lower than the threshold.

[0139] 3. Pea / cassava / rice starch: Differences in molecular weight distribution cause phase separation, and interfacial defects lead to uneven tensile strength and increased fluctuations in elongation at break.

[0140] Conclusion: The branching ratio of corn starch can optimize the molecular chain entanglement density and achieve the best match between strength and extensibility. The mechanical properties of the alternative components (potato starch, wheat starch, pea starch, cassava starch and rice starch) are not as good as those of group M.

[0141] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for preparing a ceramic bottle sealing film with antibacterial properties, characterized in that, The method includes the following steps: (1) After dissolving gallic acid in water, a film-forming system is obtained. Konjac glucomannan, corn starch, and tarara gum are added to the system and stirred. Then glycerol is added and stirred to prepare a coating solution. The amount of gallic acid added is 0-1.0 g / 100 ml, the amount of konjac glucomannan added is 0.3-1.0 g / 100 ml, the amount of corn starch added is 1.0-2.0 g / 100 ml, the amount of tara gum added is 0-0.7 g / 100 ml, and the amount of glycerol added is 0.25-0.75 g / 100 ml. None of the above amounts are 0. (2) After the prepared coating solution is degassed while hot, the coating solution is immediately applied evenly to the mouth of the ceramic bottle to be sealed; then it is placed to dry so that a thin film is formed at the mouth of the bottle, and the bottle mouth is sealed by using a bottle stopper / cap in conjunction with the outer coating material.

2. The preparation method according to claim 1, characterized in that, In step (1), gallic acid is dissolved in water at a temperature of at least 90°C.

3. The preparation method according to claim 2, characterized in that, In step (1), the stirring conditions are: stirring at 85-95°C and 100-300 rpm for 30-60 minutes.

4. The preparation method according to claim 3, characterized in that, In step (1), the stirring conditions are: stirring at 90°C and 200 rpm for 30 minutes.

5. The preparation method according to claim 4, characterized in that, In step (2), the degassing method is to use ultrasonic degassing with conditions of 75-150W and a time of 10-30min.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The amount of gallic acid added is 0.5g / 100ml, the amount of konjac glucomannan added is 0.9g / 100ml, the amount of corn starch added is 2.0g / 100ml, the amount of tara gum added is 0.1g / 100ml, and the amount of glycerol added is 0.5g / 100ml.

7. The preparation method according to any one of claims 1 to 5, characterized in that, The amount of gallic acid added is 0.25g / 100ml, the amount of konjac glucomannan added is 0.9g / 100ml, the amount of corn starch added is 2.0g / 100ml, the amount of tara gum added is 0.1g / 100ml, and the amount of glycerol added is 0.5g / 100ml.

8. The preparation method according to any one of claims 1 to 5, characterized in that, The amount of gallic acid added is 0.75g / 100ml, the amount of konjac glucomannan added is 0.9g / 100ml, the amount of corn starch added is 2.0g / 100ml, the amount of tara gum added is 0.1g / 100ml, and the amount of glycerol added is 0.5g / 100ml.

9. The preparation method according to any one of claims 1 to 5, characterized in that, The drying process is hot air drying, and the drying conditions are: 20-30℃, 20-24h.

10. The ceramic bottle sealing film prepared by any one of claims 1 to 9.

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