Functional paper dyed with ampelopsis grossedentata and its preparation method and application

Abstract

The application provides a functional paper dyed by Ampelopsis grossedentata and a preparation method and application thereof, and belongs to the technical field of dyeing. The raw material of the functional paper dyed by Ampelopsis grossedentata is composed of wood pulp, Ampelopsis grossedentata dye and mordant, wherein the Ampelopsis grossedentata dye is an ethanol aqueous solution extract of Ampelopsis grossedentata. The preparation method of the functional paper comprises the following steps: mixing Ampelopsis grossedentata powder and an ethanol aqueous solution, reflux extraction, combining filtrates, concentration, drying, grinding, and obtaining Ampelopsis grossedentata dye; mixing wood pulp and water, defibrating, separating and squeezing, dyeing by using the Ampelopsis grossedentata dye, and obtaining dyed pulp; sheeting the obtained dyed pulp, drying, and obtaining the functional paper dyed by Ampelopsis grossedentata. The functional paper dyed by Ampelopsis grossedentata provided by the application has good antibacterial effect and antioxidant effect, and has a certain color itself, and has a wide application prospect in product packaging and ancient book protection.

Description

Technical Field

[0001] This invention belongs to the field of dyeing technology, and relates to a functional paper dyed with vine tea, its preparation method and application. Background Technology

[0002] Paper, glass, metal, and plastic are the four pillar materials of modern society. Among them, paper is favored by the public due to its advantages such as low raw material cost, customizable processing, and stable quality. People have increasingly higher requirements for the color and uses of paper, prompting paper production to move towards green, environmentally friendly, functional, and high-quality directions. Faced with the increasingly deteriorating environment and dwindling natural resources, people are paying more and more attention to ecological dyeing. Therefore, plant dyes have gained widespread attention due to their natural origin, non-toxicity, biodegradability, and bioactivity. On the other hand, colored paper is a very important paper product. However, the large-scale use of synthetic dyes in the production of colored paper not only poses greater challenges to resources and the environment but also threatens human health. Therefore, the use of natural substances for paper dyeing has significant research value.

[0003] Vine tea is made from the naturally sun-dried stems and leaves of *Ampelopsis grossedentata*, a plant belonging to the genus *Ampelopsis* of the family Vitaceae. Studies have confirmed that *Ampelopsis grossedentata* mainly contains flavonoids, polysaccharides, and polyphenols, with flavonoids accounting for up to 40%. It possesses antioxidant, anti-cancer, anti-inflammatory, blood sugar-lowering, and blood lipid-lowering effects, making it a medicinal herb. However, currently only a portion of the tender stems and leaves of *Ampelopsis grossedentata* can be commercially exported. The large amount of aged stems and leaves produced annually due to pruning and shaping are simply discarded, severely reducing the plant's utilization value.

[0004] Patent CN110863386A discloses a fruit-growing bag paper and its manufacturing method. The raw materials include 30-50% bleached softwood pulp, 20-30% bleached hardwood pulp, 4-6% rosin, 5-7% aluminum sulfate, 8-10% emulsified paraffin solution, 4-8% acrylate copolymer, 12-16% water-soluble organic fluoride resin, 6-10% citric acid, 1-3% sodium chloride, 7-9% wet strength agent, 2-4% whitening agent, 5-9% water-resistant agent, 8-10% preservative, and 4-10% mildew-proof and bactericidal agent. The antifungal and bactericidal agent comprises the following components in parts by weight: piperine 22-26 parts, carbendazim 24-28 parts, Litsea cubeba oil 20-24 parts, total saponins of Panax notoginseng 20-24 parts, eugenol 24-28 parts, potassium sorbate 24-28 parts, dill seed volatile oil 20-24 parts, and vine tea extract 24-28 parts. The disclosed technical effects include high water resistance, high wet strength, good surface smoothness, high antibacterial and antifungal properties, and good preservation properties. However, this disclosure does not provide a better functional paper dyed with vine tea or its preparation method.

[0005] Patent CN108070039B discloses a method for simultaneously extracting polysaccharides and flavonoids from *Ampelopsis grossedentata*. The method involves adding *Ampelopsis grossedentata* stems and leaves to deionized water, first extracting with ultrasound, then extracting with enzymatic hydrolysis, followed by centrifugation; concentrating the separated liquid to a solid content greater than or equal to 20-30%; adding ethanol with a concentration ≥95% to the concentrated liquid, adjusting the ethanol concentration to 75-80%, stirring for 10-20 minutes, allowing to stand for 2-3 hours, centrifuging, and drying the separated material to obtain *Ampelopsis grossedentata* polysaccharides; recovering the ethanol from the centrifuged liquid and drying to obtain *Ampelopsis grossedentata* flavonoid extract. This invention can simultaneously extract *Ampelopsis grossedentata* polysaccharides and flavonoids, with an extraction rate of over 95% for *Ampelopsis grossedentata* polysaccharides and over 96% for flavonoids. However, this disclosure does not provide a better method for preparing functional paper dyed with *Ampelopsis grossedentata*.

[0006] Patent CN114960277A discloses a vine tea extract, its preparation method, and its application in a waterproof and oil-repellent agent. The method involves ultra-finely pulverizing dried vine tea leaves to fully release the vine tea flavonoids. Microwave-assisted heating is then used to further break down cell walls, releasing even more vine tea flavonoids. The extraction process fully utilizes the solubility of vine tea flavonoids at different temperatures, their dissolution curve in boiling water, and their rapid thermal dissolution and slow precipitation properties to obtain a vine tea extract with an extraction rate of 80% and a purity of 95%. The extraction method uses pure water extraction without any additives, making it safe, healthy, and environmentally friendly, and yielding a food-grade natural antibacterial agent. This invention also discloses the vine tea extract prepared using the described extraction method and a waterproof and oil-repellent agent containing the vine tea extract. Because the waterproof and oil-repellent agent contains the vine tea extract as an antibacterial agent, it not only prevents microbial contamination but also poses no health risks. However, this disclosure does not provide a better method for preparing functional paper dyed with vine tea.

[0007] In summary, existing technologies still struggle to provide a better functional paper dyed with vine tea and a method for preparing such paper. Summary of the Invention

[0008] In view of this, the present invention utilizes vine tea and waste materials as plant dyes for dyeing wood pulp fibers, satisfying the appearance and color requirements of paper while also endowing the paper with unique bioactive functions, expanding the application fields of paper, further enhancing its commercial value, and realizing the transformation of "waste into treasure" from *Ampelopsis grossedentata*, especially its dried stems. Addressing the problem that existing technologies cannot provide a functional paper dyed using vine tea, the purpose of this invention is to provide a functional paper dyed with vine tea, its preparation method, and its applications.

[0009] To achieve the above-mentioned objectives, on the one hand, the present invention provides a functional paper dyed with vine tea, the raw materials of which consist of wood pulp, vine tea dye, and mordant, wherein the vine tea dye is an ethanol aqueous solution extract of vine tea.

[0010] Preferably, the wood pulp is at least one of ordinary wood pulp and poplar chemimechanical pulp.

[0011] The types of ordinary wood pulp include, but are not limited to, Southern Bleached Softwood Sulfate Pulp (SBSK), Northern Bleached Softwood Sulfate Pulp (NBSK), Bleached Hardwood Sulfate Pulp (LBKP), Bleached Eucalyptus Pulp (BEKP), and Bleached Softwood Kraft Pulp (BSKP).

[0012] More preferably, the beating degree of the ordinary wood pulp is 42-45°SR.

[0013] More preferably, and as an example of the present invention, the wood pulp is poplar chemimechanical pulp.

[0014] Preferably, the raw material for the vine tea is selected from at least one of Guangdong snake grape, three-lobed snake grape, fang tooth snake grape, and large-leaf snake grape.

[0015] More preferably, the raw material for the vine tea is selected from one of the following: Guangdong snake grape, three-lobed snake grape, fang tooth snake grape, and large-leaf snake grape.

[0016] More preferably, the raw material for the vine tea is Ampelopsis thunbergii.

[0017] More preferably, and as an example of the present invention, the vine tea is vine tea obtained by drying the stems and leaves of *Alopecurus aequalis*.

[0018] Furthermore, the vine tea is made from discarded stems and leaves of the Ampelopsis thunbergii.

[0019] Preferably, the mordant is an aluminum-containing salt.

[0020] More preferably, the aluminum-containing salt is selected from at least one of aluminum chloride, aluminum sulfate, aluminum nitrate, and alum.

[0021] More preferably, the aluminum-containing salt is selected from one of aluminum chloride, aluminum sulfate, aluminum nitrate, and alum.

[0022] More preferably, and as an example of the present invention, the aluminum-containing salt is alum.

[0023] Preferably, the ethanol aqueous solution is a 70%-80% ethanol aqueous solution.

[0024] On the other hand, the present invention provides a method for preparing the above-mentioned functional paper, comprising the following steps:

[0025] S1. Preparation of vine tea dye: Mix vine tea powder with ethanol aqueous solution, reflux extract, combine filtrates, concentrate, dry, grind to obtain vine tea dye;

[0026] S2. Preparation of dyeing paste: Mix wood pulp with water, loosen, separate and squeeze dry, and use the rattan tea dye obtained in step S1 for dyeing to obtain dyeing paste;

[0027] S3. Preparation of dyed paper: The dyeing pulp obtained in step S2 is made into sheets and dried to obtain functional paper dyed with vine tea.

[0028] Preferably, in step S1, the method for preparing the vine tea powder includes the following steps:

[0029] The vine tea is dried, pulverized, and sieved to obtain vine tea powder with a particle size of 40-60 mesh.

[0030] More preferably, the drying is oven drying.

[0031] More preferably, the pulverization is performed by placing the plant into a plant pulverizer.

[0032] Preferably, in step S1, the mixing of vine tea powder and ethanol aqueous solution specifically involves mixing vine tea powder with 70%-80% ethanol aqueous solution at a solid-liquid mass ratio of 1:15-20.

[0033] As an example of the present invention, vine tea powder is mixed with a 75% aqueous ethanol solution at a solid-liquid mass ratio of 1:18.

[0034] As an example of the present invention, vine tea powder is mixed with 70% ethanol aqueous solution at a solid-liquid mass ratio of 1:15.

[0035] As an example of the present invention, vine tea powder is mixed with 80% ethanol aqueous solution at a solid-liquid mass ratio of 1:20.

[0036] Preferably, in step S1, the reflux extraction is performed 2-4 times.

[0037] More preferably, and as an example of the present invention, the reflux extraction is performed twice.

[0038] Preferably, in step S1, the reflux extraction temperature is 60-70℃.

[0039] As an example of the present invention, the reflux extraction temperature is 60°C.

[0040] As an example of the present invention, the reflux extraction temperature is 65°C.

[0041] As an example of the present invention, the reflux extraction temperature is 70°C.

[0042] Preferably, in step S1, the extraction time for each reflux extraction is 50-60 minutes.

[0043] As an example of the present invention, the extraction time is 50 minutes each time.

[0044] As an example of the present invention, the extraction time is 55 minutes each time.

[0045] As an example of the present invention, the extraction time is 60 minutes each time.

[0046] Preferably, in step S1, the reflux extraction is followed by filtration to obtain the filtrate.

[0047] More preferably, the filtration is performed using a filter cloth.

[0048] Preferably, in step S1, the concentration is a rotary evaporation concentration.

[0049] More preferably, the conditions for the rotary evaporation concentration are as follows:

[0050] Rotary evaporation concentration was carried out at a temperature of 45-60℃ and a rotation speed of 90-110 rpm.

[0051] The purpose of rotary evaporation concentration here is to reduce the volume of the reflux extract and evaporate the ethanol in the solution to facilitate the next step of freeze-drying.

[0052] Preferably, in step S1, the drying is freeze drying.

[0053] More preferably, the freeze-drying conditions are as follows:

[0054] At -80℃, the vacuum pressure is 0.5-2 Pa, and the cold drying time is 36-48 h.

[0055] Preferably, in step S1, the grinding specifically refers to grinding into powder of 100-150 mesh.

[0056] Preferably, in step S2, the wood pulp is at least one of ordinary wood pulp and poplar chemimechanical pulp.

[0057] The types of ordinary wood pulp include, but are not limited to, Southern Bleached Softwood Sulfate Pulp (SBSK), Northern Bleached Softwood Sulfate Pulp (NBSK), Bleached Hardwood Sulfate Pulp (LBKP), Bleached Eucalyptus Pulp (BEKP), and Bleached Softwood Kraft Pulp (BSKP).

[0058] More preferably, in step S2, the beating degree of the ordinary wood pulp is 42-45°SR.

[0059] More preferably, in step S2, the wood pulp is poplar wood pulp.

[0060] Furthermore, as an example of the present invention, the poplar pulp is poplar chemimechanical pulp.

[0061] Preferably, in step S2, the dissolution specifically involves dissolution at 10,000 rpm for 2 minutes.

[0062] Preferably, in step S2, the dyeing process using the vine tea dye obtained in step S1 specifically involves:

[0063] Place the squeezed slurry into the dyeing solution containing the vine tea dye obtained in step S1, heat to 40-50℃, stir evenly at a stirring speed of 300-350 rpm, and dye for 40-60 minutes.

[0064] More preferably, the method for preparing the dye solution includes the following steps:

[0065] Add mordant and vine tea dye obtained in step S1 to distilled water at 80-85℃, and adjust the pH of the solution to 5.8-7. The amount of vine tea dye added is 8%-12% of the dry matter mass of the wood pulp in step S2, and the amount of alum added is 3%-4% of the dry matter mass of the wood pulp in step S2.

[0066] As an example of the present invention, the amount of vine tea dye added is 8% of the dry matter mass of the wood pulp in step S2.

[0067] As an example of the present invention, the amount of vine tea dye added is 10% of the dry matter mass of the wood pulp in step S2.

[0068] As an example of the present invention, the amount of vine tea dye added is 12% of the dry matter mass of the wood pulp in step S2.

[0069] Preferably, in step S3, the paper transfer is performed using a paper transfer device.

[0070] Preferably, the drying is vacuum drying.

[0071] More preferably, the vacuum drying is vacuum heating drying.

[0072] More preferably, the vacuum heating drying temperature is 90-95℃ and the drying time is 10-15 min.

[0073] In another aspect, the present invention provides the application of the above-mentioned functional paper and / or the functional paper prepared by the above-mentioned preparation method in product packaging.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] (1) A functional paper dyed with vine tea is provided, which uses waste plant stems and leaves as the source of natural plant dyes, realizing the transformation of waste into treasure, which is conducive to the recycling of resources and environmental protection.

[0076] (2) Using vine tea dye to dye paper results in a natural yellow color that is very close to the yellow of ancient paper books. Applying this functional paper to the restoration of ancient books will result in a more natural and uniform effect.

[0077] (3) Compared with existing packaging materials, the functional paper provided by the present invention has good antibacterial and antioxidant properties and has broad application prospects in the packaging of food, cosmetics and other products.

[0078] (4) The preparation method of this functional paper is simple and conducive to industrial production and promotion. Attached Figure Description

[0079] Figure 1 These are colony photographs of the functional paper prepared in Example 2, and the papers prepared in Comparative Examples 2 and 3, in experiments against E. coli and Staphylococcus aureus.

[0080] Figure 2 The bar chart shows the antibacterial effect of the functional paper prepared in Examples 1-5 and the paper prepared in Comparative Examples 1-3. The antibacterial test includes the anti-Escherichia coli test and the anti-Staphylococcus aureus test. * indicates a significant difference compared with the same bacteria in Comparative Example 1 and p < 0.05, and ** indicates a significant difference compared with the same bacteria in Comparative Example 1 and p < 0.01.

[0081] Figure 3 The graph shows the peroxide value of the functional paper prepared in Example 2 and the paper prepared in Comparative Example 3 during a 35-day antioxidant test of packaged cheese. Detailed Implementation

[0082] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following description is merely an exemplary illustration of the scope of protection of the present invention, and those skilled in the art can make various changes and modifications to the invention based on the disclosed content, which should also fall within the scope of protection of the present invention.

[0083] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention were obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process was carried out at room temperature.

[0084] In the following examples and comparative examples, the poplar chemimechanical pulp used was produced by Shandong Heze Yuncheng Haisen Wood Industry Co., Ltd., batch number 111361. The strains of *Escherichia coli* (ATCC 8739) and *Staphylococcus aureus* (ATCC 6538) were provided by the Engineering Center of Nanjing Forestry University. LB broth was purchased from Qingdao High-Tech Industrial Park Haibo Biotechnology Co., Ltd.

[0085] Example 1

[0086] Preparation of functional paper dyed with vine tea.

[0087] S1: Preparation of vine tea dye.

[0088] The dried, waste stems and leaves of *Ampelopsis grossedentata* were pulverized in a plant pulverizer, and then sieved to obtain vine tea powder with a particle size of 40-60 mesh. The vine tea powder was added to a 75% ethanol aqueous solution at a solid-liquid mass ratio of 1:18, and extracted using a reflux condenser at 65℃ for 55 minutes each time, filtered through a 300-mesh filter cloth. The extraction was repeated twice, and the two extracts were combined and placed in a dark brown glass bottle. The extract was concentrated by rotary evaporation at 45-60℃ and 90-110 r / min. The concentrated extract was then frozen at -20℃ for 48-60 hours, and then quickly placed in a vacuum freeze dryer at -80℃ and a vacuum pressure of 0.5-2 Pa for 36-48 hours. After drying, the powder was ground to 100-150 mesh, which is the vine tea dye.

[0089] S2: Prepare dyeing paste.

[0090] Poplar chemimechanical pulp with a dry matter content of 2.041 g ± 0.002 g (paper basis weight: 65 g / m³) 2 Place the slurry in water and decompose it at 10,000 rpm for 2 minutes. After filtration, remove the slurry and squeeze it dry. Place the squeezed slurry into the dyeing solution and heat it to 40-50℃ using a water bath. At the same time, use an electric stirrer to stir it evenly at a speed of 300-350 rpm. Dye for 40-60 minutes to obtain the dyeing slurry.

[0091] The preparation method of the above dye solution is as follows:

[0092] Add alum and the vine tea dye obtained in step S1 to 130-140 mL of distilled water at 80-85℃, and adjust the pH of the solution to 7 using sodium hydroxide solution to obtain the dye solution. The amount of vine tea dye added is 8% of the dry mass of poplar chemimechanical pulp used, and the amount of alum added is 3%-4% of the dry mass of poplar chemimechanical pulp used.

[0093] S3: Prepare dyed paper.

[0094] The dyeing slurry obtained in step S2 is formed into sheets using a paper sheeter, and then vacuum dried at a temperature of 90-95℃ for 10-15 minutes to obtain functional paper dyed with vine tea.

[0095] Example 2

[0096] Compared with Example 1, in step S2, the amount of vine tea dye added is 10% of the dry matter mass of the poplar chemimechanical pulp used, and the rest are the same.

[0097] Example 3

[0098] Compared with Example 1, in step S2, the amount of vine tea dye added is 12% of the dry matter mass of the poplar chemimechanical pulp used, and the rest are the same.

[0099] Example 4

[0100] Compared with Example 2, in step S1, the vine tea powder was added to an 80% ethanol aqueous solution at a solid-liquid mass ratio of 1:20, the extraction temperature was changed to 60℃, and the extraction time was changed to 60 min each time, with the rest remaining the same.

[0101] Example 5

[0102] Compared with Example 2, in step S1, the vine tea powder was added to a 70% ethanol aqueous solution at a mass ratio of 1:15, the extraction temperature was changed to 70℃, and the extraction time was changed to 50 min each time, with the rest remaining the same.

[0103] Comparative Example 1

[0104] Compared with Example 1, step S1 is changed as follows:

[0105] S1: The dried waste stems and leaves of Ampelopsis lanceolata are crushed in a plant pulverizer, and then the crushed plant material is sieved through a sieve to obtain vine tea powder of 40-60 mesh. The vine tea powder is added to pure water at a solid-liquid mass ratio of 1:18. A reflux condenser is used to extract the tea at 65°C for 55 minutes each time. The tea is filtered through a 300-mesh filter cloth and extracted twice. The two extracts are combined and placed in a dark brown glass bottle. The extract is concentrated by rotary evaporation at 45-60°C and 90-110 r / min. The concentrated extract is frozen at -20°C for 48-60 hours and then quickly placed in a vacuum freeze dryer at -80°C and 0.5-2 Pa for 36-48 hours. After drying, the tea is ground into powder of 100-150 mesh, which is the vine tea dye.

[0106] The remaining steps are the same.

[0107] Comparative Example 2

[0108] Method for preparing undyed paper.

[0109] The poplar chemimechanical pulp used in step S2 of Example 1 was decomposed according to the method of Example 1, formed into sheets by a paper sheeter, and vacuum dried at a temperature of 90-95°C for 10-15 minutes to obtain undyed paper.

[0110] Comparative Example 3

[0111] A method for preparing undyed paper with added mordant.

[0112] Compared with Comparative Example 2, after slurrying, 3% alum was added to the wood pulp, and the remaining steps were the same, finally resulting in undyed paper with added mordant.

[0113] Example 1: Colorimetric evaluation of functional paper dyed with vine tea.

[0114] 1. Evaluation Method:

[0115] The absorbance values ​​of the dye solution were measured before and after staining.

[0116]

[0117] Among them, the absorbance of A0 dye solution at the maximum absorption wavelength before staining; the dilution factor of n0 dye solution before staining; the absorbance of A1 dye solution at the maximum absorption wavelength after staining; and the dilution factor of n1 dye solution after staining.

[0118] 2. The L*, a*, and b* values ​​of the paper were measured using an X-rite spectrophotometer (Grand Rapids, Michigan, USA) under a D65 / 10° light source viewing angle. Three parallel experiments were conducted, with five test points selected on each sample, and the average value was taken.

[0119] Where L represents brightness, ranging from 0 to 100. A value of 0 indicates the darkest brightness, and a value of 100 indicates the brightest brightness.

[0120] a and b are two different colorimetric scales. a represents the color change from green to red, with a value range of -128 to 127, where -128 represents the greenest and 127 represents the reddest. b represents the color change from blue to yellow, with a value range of -128 to 127, where -128 represents the bluest and 127 represents the yellowest.

[0121] ΔE* represents the physical depth of color. It is calculated based on undyed paper. The larger the value, the deeper the color.

[0122]

[0123] Among them, Δa*=a1*-a0*, Δa*=a1*-a0*, Δa*=a1*-a0*;

[0124] a1* represents the a* value of the functional paper prepared in any one of Examples 1-5, Comparative Example 1, and Comparative Example 3, and a0* represents the a* value of the undyed paper in Comparative Example 2.

[0125] b1* represents the b* value of the functional paper prepared in any one of Examples 1-5, Comparative Example 1, and Comparative Example 3, and b0* represents the b* value of the undyed paper in Comparative Example 2.

[0126] L1* represents the L* value of the functional paper prepared in any one of Examples 1-5, Comparative Example 1, and Comparative Example 3, and L0* represents the L* value of the undyed paper in Comparative Example 2.

[0127] Using the above method, the functional paper and undyed paper prepared in Examples 1-5, Comparative Example 1, and Comparative Example 3 were evaluated respectively. The test results are shown in the table below:

[0128] Serial Number L* * b* △E* Dye uptake rate (%) Example 1 75.88±0.28 -0.9±0.13 42.05±0.25 34.92 73.78±0.11 Example 2 78.54±0.36 -2.15±0.16 45.47±0.17 36.82 86.02±0.28 Example 3 75.4±0.89 -0.61±0.33 47.01±0.37 39.56 90.84±0.17 Example 4 79.76±0.21 -1.93±0.47 46.35±0.02 37.21 87.45±0.14 Example 5 79.16±0.27 -1.88±0.19 44.18±0.25 35.40 84.71±0.33 Comparative Example 1 82.26±0.35 -1.22±0.18 32.29±0.61 23.32 52.38±0.26 Comparative Example 3 91.18±0.42 0.24±0.12 21.07±0.64 10.27 22.16±0.37

[0129] According to existing records, the ΔE* of paper-based ancient books is most similar to that of Example 1.

[0130] As can be seen from Examples 1-5 above, the method for preparing functional paper provided by the present invention has good dyeing effect. In Comparative Example 1, the ΔE* of the functional paper obtained by extracting vine tea dye using water extraction was only 23.32, and the dye uptake rate was only 52.38% ± 0.26%. It is evident that the dyeing effect of the functional paper provided by Examples 1-5 of the present invention is superior to that of Comparative Example 1. Furthermore, in Comparative Example 3, the dyeing effect of adding only alum without adding vine tea dye was far inferior to that of the other examples.

[0131] Example 2: Evaluation of the antibacterial effect of functional paper dyed with vine tea.

[0132] 1. Evaluation Method:

[0133] (1) Bacterial resuscitation

[0134] Transfer 100 μL of the bacterial stock solution to sterilized LB broth and place it in a shaker (37℃, 200 rpm / min) for resuscitation. Remove the solution after 24 hours.

[0135] (2) Antibacterial test

[0136] The revived bacterial culture was diluted with LB broth to a concentration of 1×10⁻⁶. 3 CFU / mL, transfer 100 μL of bacterial suspension onto a 2×2 cm sample paper, incubate at 37℃ for 4 h, remove and dilute with 900 μL of LB broth, mix well, then transfer 100 μL of bacterial suspension evenly onto a plate, incubate at 37℃ for 24 h, and record observations.

[0137] 2. Results of antibacterial effect test:

[0138] Photographs of bacterial colonies in culture dishes for antibacterial tests against Escherichia coli and Staphylococcus aureus are shown below. Figure 1 As shown, the number of Escherichia coli and Staphylococcus aureus colonies in Example 2 was significantly lower than that in Comparative Examples 2 and 3, proving that the functional paper provided in Example 2 has superior antibacterial function compared to Comparative Examples 2 and 3.

[0139] Furthermore, antibacterial tests were conducted on the functional papers prepared in Examples 1-5 and the papers prepared in Comparative Examples 1-3. The average number of colonies and the standard deviation of each antibacterial test group were recorded. The test results are as follows: Figure 2 As shown.

[0140] Figure 2In the figures, * indicates a significant difference compared to the same strain of Comparative Example 1 with p < 0.05, and ** indicates a significant difference compared to the same strain of Comparative Example 1 with p < 0.01. It is evident that the antibacterial effect of the vine tea-dyed functional paper prepared in Examples 1-5 of this invention against Escherichia coli and Staphylococcus aureus is significantly higher than that of the paper prepared in Comparative Example 1.

[0141] 3. Evaluation of the antioxidant effect of functional paper dyed with vine tea.

[0142] Evaluation method: The antioxidant effect of dyed paper was evaluated according to GB5009.227-2016 "Determination of peroxide value in food". Cheese with a specification of 2×2cm was packaged with undyed paper and dyed paper, stored at 4℃, and the peroxide value was recorded every seven days.

[0143] Evaluation results:

[0144] Cheese was packaged using the functional paper dyed with vine tea provided in Example 2 and the undyed paper provided in Comparative Example 3, respectively. The peroxide value of the cheese was characterized within 0-35 days. The test results are as follows: Figure 3 As shown, the peroxide value of the cheese packaged with the dyed paper provided in Example 2 increases more slowly than that of the undyed paper provided in Comparative Example 3, demonstrating that the dyed paper has good antioxidant properties.

[0145] Furthermore, the peroxide values ​​of the functional papers prepared in Examples 1-5 and the paper prepared in Comparative Examples 1-3 for packaging cheese were measured after 14 days. Before the start of the experiment (day 0), the peroxide value of cheese in all groups was 0.016 ± 0.002 mg / 100g. The peroxide value results after 14 days are shown in the table below:

[0146]

[0147]

[0148] Among them, there were no significant differences among groups labeled with the same letter (p>0.05); there were significant differences among groups labeled with different letters (p<0.05).

[0149] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A functional paper dyed with vine tea, characterized in that, The raw materials consist of wood pulp, vine tea dye and mordant, wherein the vine tea dye is an ethanol aqueous solution extract of vine tea; The mordant is an aluminum-containing salt; The method for preparing the functional paper includes the following steps: S1. Preparation of vine tea dye: Mix vine tea powder with ethanol aqueous solution, reflux extract, combine filtrates, concentrate, dry, grind to obtain vine tea dye; S2. Preparation of dyeing paste: Mix wood pulp with water, loosen, separate and squeeze dry, and use the rattan tea dye obtained in step S1 for dyeing to obtain dyeing paste; S3. Preparation of dyed paper: The dyeing pulp obtained in step S2 is made into sheets and dried to obtain functional paper dyed with vine tea. The aluminum-containing salt is selected from at least one of aluminum chloride, aluminum sulfate, aluminum nitrate, and alum; In step S1: the vine tea powder and the ethanol aqueous solution are mixed by mixing the vine tea powder with a 70%-80% ethanol aqueous solution at a solid-liquid mass ratio of 1:15-20; the reflux extraction temperature is 60-70℃; the extraction time for each reflux extraction is 50-60 min; and the filtrate is collected after reflux extraction. In step S2: the amount of vine tea dye added is 8%-12% of the dry matter mass of the wood pulp mentioned in step S2.

2. The functional paper according to claim 1, characterized in that, In step S1: The preparation method of the vine tea powder includes the following steps: drying, pulverizing, and sieving the vine tea to obtain vine tea powder with a particle size of 40-60 mesh; the reflux extraction is performed 2-4 times; the concentration is performed by rotary evaporation; the drying is performed by freeze drying; and the grinding is specifically performed by grinding into powder of 100-150 mesh.

3. The functional paper according to claim 1, characterized in that, In step S2: The wood pulp is ordinary wood pulp; the dissolution is specifically dissolution at 10,000 rpm for 2 minutes; The dyeing process using the vine tea dye obtained in step S1 specifically involves placing the squeezed slurry into a dyeing solution containing the vine tea dye obtained in step S1, heating it to 40-50°C, stirring it evenly at a stirring speed of 300-350 rpm, and dyeing it for 40-60 minutes.

4. The functional paper according to claim 3, characterized in that, The method for preparing the dye solution includes the following steps: Add mordant and vine tea dye obtained in step S1 to distilled water at 80-85℃, and adjust the pH of the solution to 5.8-7. The mordant is alum, and the amount of alum added is 3%-4% of the dry matter mass of the wood pulp in step S2.

5. The functional paper according to claim 1, characterized in that, In step S3, the sheet is formed by using a paper sheet forming machine; the drying is vacuum drying at a temperature of 90-95℃ for 10-15 minutes.

6. The application of the functional paper according to any one of claims 1-5 in product packaging.

Images