Environment-friendly polysaccharide preservative film and preparation method thereof
By using an alkaline-thermal induction technique combining sodium carboxymethyl cellulose and enoki mushroom polysaccharides, a polysaccharide preservation film that is easy to decompose and has good mechanical and hydrophobic properties was prepared. This solved the problems of petroleum-based plastic preservation films being difficult to decompose and having insufficient performance, and achieved an environmentally friendly food preservation effect.
Patent Information
- Application Number
- CN202511945729.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-02-27
AI Technical Summary
Existing petroleum-based plastic cling film is difficult to decompose, leading to environmental pollution. At the same time, sodium carboxymethyl cellulose-based cling film has poor mechanical properties, low hydrophobicity, and no biological activity, making it difficult to meet the actual needs of food preservation.
Using sodium carboxymethyl cellulose and enoki mushroom polysaccharide as base film materials, the degree of cross-linking and entanglement between polysaccharide molecules was improved by alkaline heat induction technology, and glycerol was used as a cross-linking agent to prepare a polysaccharide preservation film with good mechanical and hydrophobic properties.
The prepared polysaccharide preservation film is easy to decompose, has gas regulation function, excellent mechanical properties and hydrophobic properties, and is suitable for food preservation, thus improving the level of food safety management.
Smart Images
Figure CN121574431A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of biological macromolecule composite film, in particular to an environment-friendly polysaccharide preservative film and a preparation method thereof. BACKGROUND
[0002] With the improvement of people's living standards and the enhancement of food safety awareness, consumers have higher and higher requirements for food safety and environmental protection. As a necessity in life, preservative film is widely used in food preservation. However, the commonly used petroleum-based plastic preservative film on the market has problems such as difficult to decompose and environmental pollution, and how to prepare a substitute for petroleum-based plastic preservative film for food preservation has become a problem to be solved.
[0003] In recent years, the related research of polysaccharide-based preservative film has attracted more and more attention of scientific researchers. Sodium carboxymethyl cellulose is a polysaccharide material widely used in the food industry. However, the current sodium carboxymethyl cellulose-based preservative film has problems such as poor mechanical properties, low hydrophobicity, and no biological activity. This makes the existing sodium carboxymethyl cellulose preservative film difficult to meet the actual application requirements in production and life. SUMMARY
[0004] The first purpose of the present application is to provide an environment-friendly polysaccharide preservative film which is safe, green and has high mechanical properties. The second purpose of the present application is to provide a preparation method of the environment-friendly polysaccharide preservative film.
[0005] Technical scheme: The environment-friendly polysaccharide preservative film provided by the present application comprises a base film and a crosslinking agent, the base film is synthesized from sodium carboxymethyl cellulose and flammulina velutipes polysaccharide, and the crosslinking agent is glycerol. The surface of the indicator film is smooth, the whole is transparent, and the color has a slight yellow color.
[0006] By alkali heat induction on the polysaccharide film liquid, the mechanical properties and hydrophobic properties of the composite film can be improved. Alkali heat induction can improve the crosslinking and winding degree between polysaccharide molecules, so as to improve the binding strength between polysaccharides. The polysaccharide preservative film prepared by this method has the functions of easy decomposition and gas regulation, and has good effect in preservation application.
[0007] Preferably, the mass ratio of sodium carboxymethyl cellulose to flammulina velutipes polysaccharide is 47:3.
[0008] The preparation method of the environment-friendly polysaccharide preservative film provided by the present application comprises the following steps: (1) mixing and dissolving sodium carboxymethyl cellulose and flammulina velutipes polysaccharide with deionized water, and adding glycerol to obtain a polysaccharide film liquid; (2) adding sodium hydroxide solution to the composite film liquid obtained in step (1) to adjust pH, and heating and stirring for 90 min; (3) After the film-forming solution is mixed uniformly, ultrasonic defoaming is performed, the solution is poured into a mold, and drying is performed in an oven at 50 DEG C to obtain the polysaccharide preservative film.
[0009] Preferably, in step (1), the deionized water is 150 ml, the sodium carboxymethyl cellulose is 2.82 g, the Flammulina velutipes polysaccharide is 0.18 g, and the glycerol is added in an amount of 1.5 ml. Different proportions of the base material can result in different mechanical strengths of the composite film, and too much or too little Flammulina velutipes polysaccharide can cause the mechanical properties of the polysaccharide preservative film to decrease.
[0010] Preferably, in step (1), the preparation method of the Flammulina velutipes polysaccharide comprises the following steps: (1) Fresh Flammulina velutipes is washed and dried in a hot air drying oven at 50-60 DEG C until the weight is constant, is crushed, and is passed through a 60-mesh sieve to obtain a powder; (2) The Flammulina velutipes powder is added to deionized water, and the solid-liquid ratio is 1:25 (g / mL); (3) Water bath stirring is performed at 80 DEG C for 4 h, centrifugation is performed at a speed of 4000 r / min for 10 min, the supernatant is collected and rotary evaporation is performed to obtain a Flammulina velutipes polysaccharide solution, 4 volumes of anhydrous ethanol are added, the precipitate is collected, and freeze-drying is performed to obtain the Flammulina velutipes polysaccharide.
[0011] Preferably, in step (1), the pH is adjusted to 7-10, and the heating temperature is 85 DEG C. Too high a pH and temperature can cause the polysaccharide chain to hydrolyze, thereby causing the mechanical properties of the polysaccharide preservative film to decrease.
[0012] Preferably, in step (3), the ultrasonic defoaming time is 10 min, and the drying time is 10 h. Too long an ultrasonic time can cause the polysaccharide chain to break, the viscosity of the film solution to decrease, and the strength of the polysaccharide preservative film to decrease.
[0013] Advantages: Compared with the prior art, the present application has the following remarkable advantages: (1) The use of sodium carboxymethyl cellulose combined with Flammulina velutipes polysaccharide and the alkali heat induction technology improve the mechanical properties and hydrophobic properties of the preservative film; (2) The raw materials are safe and environmentally friendly, there are no food safety hazards, the preservative film has a short decomposition period; (3) The preparation method is simple and easy to implement, is convenient for large-scale production and popularization and application, provides a new material for food preservation, and helps to improve the food safety management level; (4) The preservative film has water and gas regulation functions, and has good application effects on food preservation. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 The mechanical property diagram of Examples 1-2 and Comparative Examples 1-2; Figure 2 The water contact angle diagram of Examples 1-2 and Comparative Examples 1-2; Figure 3 Figure 1 is a soil burial decomposition rate graph for Examples 1-2 and Comparative Examples 1-2; Figure 4 Figure 2 is an antioxidant performance graph for Examples 1-2 and Comparative Examples 1-2; Figure 5 is an abstract drawing. DETAILED DESCRIPTION
[0015] The technical solutions of the present application are further described below in conjunction with examples. Examples
[0016] The preparation method of the environment-friendly polysaccharide preservative film comprises the following steps: (1) 2.82 g of sodium carboxymethyl cellulose and 0.18 g of flammulina velutipes polysaccharide are added to 150 ml of deionized water, and 1.5 ml of glycerol is added to obtain a polysaccharide film solution; (2) Sodium hydroxide solution is added to the composite film solution obtained in step (1) to adjust the pH to 7, and heated and stirred at 85°C for 90 min; (3) After the film-forming solution is uniformly mixed, ultrasonic defoaming is performed for 10 min, and then poured into a mold, dried in an oven at 50°C for 10 h to obtain the polysaccharide preservative film, which is named FVP-CMC pH7 .
[0017] The preparation method of the flammulina velutipes polysaccharide comprises the following steps: (1) Fresh flammulina velutipes is washed and dried in a hot air drying oven at 50-60°C until the weight is constant, crushed, and passed through a 60-mesh sieve to obtain a powder; (2) The flammulina velutipes powder is added to deionized water, and the solid-liquid ratio is 1:25 (g / mL); (3) Stir in a water bath at 80°C for 4 h, centrifuge at a speed of 4000 r / min for 10 min, collect the supernatant and rotary evaporate to obtain a flammulina velutipes polysaccharide solution, add 4 times the volume of anhydrous ethanol, collect the precipitate, and freeze-dry to obtain flammulina velutipes polysaccharide. Examples
[0018] On the basis of Example 1, in the preparation process of the film, step (2) is adjusted to pH 10, and the remaining conditions are unchanged, to obtain a polysaccharide preservative film, which is named FVP-CMC pH10 .
[0019] On the basis of Example 1, in the preparation process of the film, step (1) is changed from adding 0.18 g of flammulina velutipes polysaccharide to adding 0.18 g of sodium carboxymethyl cellulose, and the remaining conditions are unchanged, to obtain a polysaccharide preservative film, which is named CMC pH7 .
[0020] On the basis of Example 2, 0.18 g of sodium carboxymethyl cellulose was added in step (1) in the preparation process of the film instead of 0.18 g of Flammulina velutipes polysaccharide, and the remaining conditions were unchanged to obtain the indicated film, which was named as CMC pH10 .
[0021] 1. Mechanical property test of the preservative film The mechanical property test was performed on Examples 1-2 and Comparative Examples 1-2. The thickness of the film was measured at six random points using a micrometer, and the average value was taken as the thickness of the film, in mm. The tensile strength (TS) and elongation at break (EB) of the film were measured using a texture analyzer. The initial clamping distance was 50 mm, and the tensile rate was 0.5 mm / s. The tensile strength and elongation at break were calculated according to the following formulas, respectively: TS = (F x d) / w EB (%) = 100 x (L - L0) / L0 wherein TS is the tensile strength, MPa; F is the maximum tensile force borne by the sample at break, N; m is the width of the film, mm; d is the thickness of the label, mm; EB is the elongation at break, %; L0 is the initial length of the film, mm; and L is the final length of the film at break, mm.
[0022] The test results are shown in Table 1. Figure 1 Mechanical property is the most important indicator in the application of the film, and a good film is easy to stretch and difficult to break under stress. As can be seen from the figure, alkali heat treatment at different pH has little effect on the elongation at break of the composite film, but the addition of Flammulina velutipes polysaccharide helps to significantly improve the elongation at break of the composite film. At the same time, the addition of Flammulina velutipes polysaccharide significantly increases the tensile strength of the composite film. The tensile strength of the composite film also increases when the pH is adjusted to 10. As can be seen from the figure, the polysaccharide film of the example group has good mechanical properties.
[0023] 2. Water contact angle test of the preservative film The water contact angle test was performed on Examples 1-2 and Comparative Examples 1-2. The film (10 mm x 20 mm) was attached to the surface of a glass slide, 10 μL of deionized water was dropped onto it, and the water contact angle of the film was measured using an optical contact angle meter.
[0024] The test results are shown in Table 2. Figure 2 The water contact angle represents the hydrophobic property of the film, and the greater the water contact angle, the better the hydrophobicity of the film, which can avoid the dissolution of the film in water during application. It can be seen that the combination of sodium carboxymethyl cellulose and Flammulina velutipes polysaccharide helps to improve the hydrophobicity of the composite film. The water contact angles of the CMC group and the FVP-CMC group both increase when the pH is adjusted to 10, which may be due to the increase in pH, which enhances the interaction between polysaccharide molecules, making the overall structure of the composite film more compact, and ultimately leading to an increase in hydrophobicity. The water contact angles from small to large are CMC pH7(77.59°), FVP-CMC pH7 (85.44°), CMC pH10 (88.26°), FVP-CMC pH10 (94.98°).
[0025] 3. Soil burial decomposition rate test of cling film The soil burial degradation rate test was carried out on Examples 1-2 and Comparative Examples 1-2. The samples of 100 mm x 100 mm were buried in a 50 mm deep plastic tray. The soil was sprayed with water once a day to control humidity. PE cling film purchased from the market was selected as a control group. Samples were taken every 4 days and photographed.
[0026] It can be seen from Figure 3 that after 64 days of soil burial degradation experiment, the degradation of the four groups of polysaccharide films was completed in turn, while the commonly used PE film on the market changed little during the experiment, which indicated that Examples 1-2 and Comparative Examples 1-2 all had good degradability and environmental friendliness. It can be found from the figure that the decomposition rate of the examples is faster than that of the comparative examples, which indicates that the addition of Pleurotus eryngii polysaccharide accelerates the degradation rate, which is related to the fact that Pleurotus eryngii polysaccharide is more conducive to the decomposition of soil microorganisms. pH7 , CMC pH7 , FVP-CMC pH10 and CMC pH10 films were decomposed in about 20 days, 24 days, 56 days and 64 days, respectively.
[0027] 4. Antioxidant performance test of cling film The DPPH radical scavenging ability test was carried out on Examples 1-2 and Comparative Examples 1-2. The DPPH radical scavenging ability was mixed with 5 ml film solution and 15 ml 0.05 mmol / L DPPH ethanol solution, and the absorbance of the sample was measured at a wavelength of 517 nm after 30 min of reaction under light shielding and oscillation. The absorbance of the sample was A1, and the absorbance of the sample with DPPH ethanol instead of the sample was A2, and the absorbance of the sample with water instead of the sample was A0. The DPPH radical scavenging rate was calculated by the formula: DPPH scavenging rate (%) = [1-(A1-A2) / A0]x100 Example 1~2 and Comparative Example 1~2 were tested for ABTS radical scavenging ability. A 7 mmol / L ABTS solution and a 2.45 mmol / L potassium persulfate solution were prepared, mixed in a 1:1 volume ratio, and allowed to stand overnight in the dark to obtain liquid A. Then, an appropriate amount of liquid A was mixed with PBS (0.1 mol / L) to adjust the proportion according to its absorbance value at a wavelength of 734 nm (between 0.70±0.02) to prepare the ABTS working solution required subsequently. 2 mL of the film solution and 4 mL of the ABTS working solution were mixed and reacted in the dark for 6 minutes. The absorbance of the sample was measured at a wavelength of 734 nm A1. Water was used instead of the ABTS working solution as the control absorbance A2. Water was used instead of the sample as the blank absorbance A0. The formula for calculating the ABTS radical scavenging rate is as follows: ABTS scavenging rate (%) = [1-(A1-A2) / A0]x100 ABTS radicals and DPPH radicals are widely used to evaluate the total antioxidant capacity of compounds. From Figure 4 It can be seen that the addition of golden needle mushroom polysaccharide can significantly improve the antioxidant capacity of the composite film. Among them, the DPPH and ABTS radical scavenging capacity of Example 1 compared with Comparative Example 1 increased by 124.81% and 779.52% respectively. The DPPH and ABTS radical scavenging capacity of Example 2 compared with Comparative Example 2 increased by 94.37% and 563.36% respectively. Therefore, the polysaccharide preservative film of the example has good antioxidant performance, which improves the preservation effect of the polysaccharide preservative film.
Claims
1. An environmentally friendly polysaccharide food preservation film, characterized in that, It is easily degradable and has antioxidant properties. The base membrane is synthesized from sodium carboxymethyl cellulose and enoki mushroom polysaccharide. The crosslinking agent is glycerol. The indicator membrane has a smooth surface, is transparent overall, and has a slight yellow tint.
2. The environmentally friendly polysaccharide preservation film according to claim 1, characterized in that, The mass ratio of sodium carboxymethyl cellulose to enoki mushroom polysaccharide is 47:
3.
3. A method for preparing the environmentally friendly polysaccharide preservation film according to claim 1, characterized in that, Includes the following steps: (1) Dissolve sodium carboxymethyl cellulose and enoki mushroom polysaccharide in deionized water, and add glycerol to obtain polysaccharide membrane solution; (2) Add sodium hydroxide solution to the composite membrane solution obtained in step (1) to adjust the pH, and heat and stir for 90 min; (3) After the film-forming solution is mixed evenly, it is degassed by ultrasonication, poured into a mold, and dried in an oven at 50 °C to obtain the polysaccharide preservation film.
4. The method for preparing the polysaccharide preservation film according to claim 3, characterized in that, In step (1), the method for preparing the enoki mushroom polysaccharide includes the following steps: (1) Clean the fresh enoki mushrooms, dry them in a hot air drying oven at 50-60 ℃ until constant weight, crush them, and pass them through a 60-mesh sieve to obtain powder; (2) Add the enoki mushroom powder to deionized water at a ratio of 1:25 (g / mL); (3) Stir in a water bath at 80 ℃ for 4 h, centrifuge at 4000 r / min for 10 min, collect the supernatant and evaporate it to obtain the enoki mushroom polysaccharide solution, add 4 times the volume of anhydrous ethanol, collect the precipitate, freeze dry it to obtain enoki mushroom polysaccharide.
5. The method for preparing the polysaccharide preservation film according to claim 3, characterized in that, In step (1), the amount of deionized water is 150 ml, sodium carboxymethyl cellulose is 2.82 g, and enoki mushroom polysaccharide is 0.18 g.
6. The method for preparing the polysaccharide preservation film according to claim 3, characterized in that, In step (1), the amount of glycerol added is 1.5 ml.
7. The method for preparing the polysaccharide preservation film according to claim 3, characterized in that, In step (1), the pH is adjusted to 7-10 and the heating temperature is 85 ℃.
8. The method for preparing the polysaccharide preservation film according to claim 3, characterized in that, In step (3), the ultrasonic debubbling time is 10 min.
9. The method for preparing the polysaccharide preservation film according to claim 3, characterized in that, In step (3), the drying time is 10 h.