58 results about "Chitosan membrane" patented technology

The invention relates to the technical field of food packaging, and discloses a composite preservative film as well as a preparation method and application thereof. The composite preservative film comprises a pectin film layer and a chitosan film layer which are arranged up and down, the pectin film layer contains an additive, the chitosan film layer contains lignin, and the additive is anthocyanin and / or an anthocyanin silver ion compound. The method comprises the following steps that S1, under the condition that a solvent exists, pectin and an additive are mixed I, then a pectin film layer is prepared through a tape casting method, and the additive is anthocyanin and / or an anthocyanin silver ion compound; in the presence of a solvent, chitosan and lignin are mixed II, and a chitosan film layer is prepared through a tape casting method; and S2, compounding the pectin film layer and the chitosan film layer to prepare the composite preservative film. The composite preservative film has antibacterial activity on various food spoilage bacteria and is high in oxidation resistance.

The invention provides a method for preparing a chitosan fiber / membrane by dissolving chitosan with an ionic liquid, and belongs to the technical field of chitosan resource utilization. According to the invention, 1, 5-diazabicyclo [4.3. 0] nonyl-5-ene (DBN) or N-methylimidazole or N-ethylimidazole is used as a raw material to prepare a series of nitrogen heterocyclic ring ionic liquids, and the prepared ionic liquid-chitosan solution is subjected to defoaming, filtering and dry spraying-wet spinning process / tape casting to prepare the chitosan fiber / membrane. The operation method is simple and convenient, the solvent is easy to recover, and efficient dissolution of chitosan can be achieved. The tensile strength of the prepared chitosan fiber is 0.47 to 1.07 cN / dtex, and the elongation at break is 3.15 to 6.82 percent; the tensile strength of the chitosan film is 6.57 to 25.07 MPa, and the elongation at break of the chitosan film is 5.51 to 12.94 percent.

The invention discloses a degradable photo-thermal antibacterial composite film based on MXene loaded epsilon-polylysine as well as preparation and application of the degradable photo-thermal antibacterial composite film. The preparation method comprises the following steps: firstly, preparing an MX-PL composite nanomaterial from successfully etched MXene and epsilon-PL through an electrostatic self-assembly effect, then adding the MX-PL composite nanomaterial into a chitosan membrane solution containing a glycerin plasticizer, uniformly stirring, carrying out ultrasonic degassing, and then preparing the photo-thermal antibacterial and degradable packaging film through a solvent casting method. The defect that the antibacterial activity is hindered due to the fact that positive ions epsilon-PL easily interact with negative ion components of a food matrix is overcome, and the two-dimensional nanoparticles capable of achieving photo-thermal antibacterial performance are obtained.

The invention provides a modified oxygen-releasing nano peroxide for degrading organic pollutants, a composite oxygen-releasing material, a preparation method and an application. The modified oxygen-releasing nano peroxide comprises an oxygen-releasing nano peroxide, a pH regulator, a polyvinyl alcohol-poly (N-isopropylacrylamide) membrane layer and a cross-linked chitosan membrane layer, the polyvinyl alcohol-poly (N-isopropylacrylamide) membrane layer wraps the oxygen-releasing nano peroxide and the pH regulator, and the cross-linked chitosan membrane layer wraps the oxygen-releasing nano peroxide and the pH regulator. The polyvinyl alcohol-poly (N-isopropylacrylamide) film layer is coated with the cross-linked chitosan film layer. The modified oxygen-releasing nano peroxide is high in purity and good in dispersity, the content of dissolved oxygen in a water body can be kept stable for a long time, and the influence on the pH value of the environment is small.

The invention discloses a green preparation method for realizing a high-performance chitosan film through pH regulation and control of a citric acid buffering agent, and belongs to the field of food packaging and high polymer materials. According to the method, a water phase separation method is adopted, a citric acid buffering agent serves as a water phase environment, and a chitosan solution is induced to be subjected to phase separation and gelation by regulating and controlling the pH value (preferably 5.0-5.5) of the citric acid buffering agent. The preparation method comprises the following specific steps: dissolving chitosan powder in an alkali urea solvent (KOH: urea: water = 7: 12: 81), inducing gelation through a citric acid buffer agent, carrying out solvent replacement through an ethanol solution, and drying and curing. According to the method, a chemical cross-linking agent does not need to be used, and the core is that a buffer system is used for regulating and controlling the phase separation process to promote aggregation among chitosan molecular chains, so that a compact physical structure network is constructed. The prepared chitosan film has excellent mechanical strength, water resistance, gas barrier property, biocompatibility and degradability, and is suitable for the fields of food, medicine packaging and the like.

The invention discloses a method for extracting and preparing angelica keiskei exosomes. The method comprises the following steps: S1, selecting an angelica keiskei sample and selecting chitosan; s2, crushing and filtering the angelica keiskei sample to obtain an extracting solution; s3, dissolving chitosan through acetic acid, forming a film through a rotary coater, and carrying out drying and heat treatment; s4, mixing the extracting solution with the dried chitosan membrane, and adsorbing the exosome through the charge effect; s5, putting the chitosan membrane into a tangential flow filtration system, collecting effluent after tangential flow filtration, and purifying the effluent; and S6, pre-freezing the purified solution, and carrying out drying treatment. The invention also discloses application of the method. The method has the beneficial effects that the angelica keiskei sample is crushed and filtered to obtain the extracting solution, then the extracting solution and the dried chitosan film are mixed at room temperature, the exosome is adsorbed through the charge effect, and the exosome is purified after being filtered by the tangential flow filtering system, so that a large amount of high-purity exosome is obtained, and the method is simple, convenient and efficient.

The invention discloses a vanillin deep eutectic reagent / chitosan coating preservative as well as a preparation method and application thereof, and belongs to the technical field of food preservatives. The vanillin deep eutectic reagent / chitosan composite coating preservative is prepared from the following raw materials in parts by mass: 1 to 9 parts of vanillin deep eutectic reagent and 10 parts of chitosan. Or 2-6 parts by mass of a film-forming agent. The vanillin deep eutectic reagent / chitosan membrane liquid or the vanillin deep eutectic reagent / chitosan membrane prepared by the invention has the technical effects of resisting microorganisms and oxidation. The liquid film can play a fresh-keeping effect on the fresh fruits through an anti-oxidation and anti-microbial mechanism so as to prolong the shelf life. And the shelf life of the food is prolonged in a film-covering and vacuumizing mode on the fresh fruits. The raw materials are natural, safe, environment-friendly, low in price and easy to obtain, the preparation process is simple and convenient, and the potential value of large-scale production and market application is achieved.

The present invention provides a medical implant, comprising (a) a matrix layer comprising chitosan; and (b) a reinforcement structure comprising polymer filaments or polymer fibers, whereby the reinforcement structure is incorporated into the matrix layer. The invention further relates to the medical implant for use in the treatment of ophthalmological diseases or skin disorders. The invention finally relates to a method for producing the medical implant of the invention.

The application discloses a solid-phase preparation method of sulfonated chitosan membrane and application of the sulfonated chitosan membrane in catalytic biodiesel preparation, and the sulfonated chitosan membrane is prepared by the following steps: chitosan powder is suspended in a dispersant in which a sulfonating agent is dissolved to perform a sulfonating reaction, sulfonated chitosan powder is obtained through solid-liquid separation, the sulfonated chitosan powder is dissolved in a membrane solvent to prepare a casting membrane liquid, the casting membrane liquid is naturally cast on a glass surface to form a membrane, and the sulfonated chitosan membrane is obtained after drying and removing the membrane solvent. The sulfonated chitosan membrane is added into a mixed solution of fatty acid and methanol, and after stirring and heating for a period of time, the sulfonated chitosan membrane is taken out, and biodiesel is obtained after removing methanol from the solution. The sulfonated chitosan membrane prepared by the application has the advantages of fast mass transfer rate, high catalytic efficiency and easy separation, and under the conditions of an alcohol / oil ratio of 10:1, a reaction temperature of 65 DEG C, a catalyst dosage of 5wt%, and a reaction time of 3h, the esterification rate reaches 92.29%. Under the same conditions, the esterification rates of powdered chitosan and commercially available macroporous ion exchange resin are 57.73% and 33.0% respectively.

This invention discloses a method for preparing and applying a chitosan-nanofibrillar-based smart indicator membrane loaded with anthocyanins and alizarin. The method includes the following steps: mixing beet powder with hydrochloric acid, washing with water until neutral, and drying; adding sodium hydroxide solution, mixing and reacting, washing with water until neutral, and drying; adding sodium chlorite solution, mixing, adjusting the pH to 3-3.5, reacting, and washing with water until neutral to obtain beet fiber; adding water, homogenizing under ultra-high pressure to obtain a beet nano-suspension; adding the beet nano-suspension to a chitosan-acetic acid solution and stirring, then adding glycerol; adding pigments, mixing, and obtaining a membrane solution; ultrasonically degassing, and drying to form a membrane. This membrane, as a food preservation indicator membrane, possesses both the characteristics and functions of food preservation and indicating food freshness; using beet nanofibers as a supplementary material improves the mechanical properties of the chitosan membrane; the addition of alizarin and anthocyanin mixed pigments enriches the color changes of the indicator membrane and improves its stability.

According to the novel preparation method of the MOFs particle doped chitosan nanofiltration membrane, crystallization of MOFs particles is concentrated in the subsequent membrane preparation process, the MOFs particles doped on a support body are used as nucleation centers, and nutrients in a membrane casting solution are attracted to the surface of the support body to grow into the MOFs particles. The content of MOFs particles on the surface of the membrane is reduced, the loss probability of MOFs is reduced, the movement process of nutrition is also beneficial to formation of a loose pore channel structure, and application of the chitosan membrane in nanofiltration is facilitated.

The application belongs to the technical field of bio-based packaging materials, and particularly relates to a novel double-layer composite film and application thereof. The novel double-layer composite film comprises the following steps: reacting palmitic anhydride and carboxymethyl cellulose to obtain carboxymethyl cellulose palmitate; adding a pH-sensitive natural dye indicator to obtain carboxymethyl cellulose palmitate nanoemulsion containing a pH-sensitive substance; then loading a natural polymer material to prepare a film material; finally adding the film material to the carboxymethyl cellulose palmitate to prepare a composite film, thereby obtaining the novel double-layer composite film. The double-layer composite film can be self-emulsified without adding a surfactant, and has the ability to load functional indicator (pH-sensitive color indicator) substances; meanwhile, the barrier performance of the film material, such as a chitosan film, to water vapor and oxygen is improved, and the double-layer composite film has a very promising application in food or fruit preservation. The method provided by the application is not only green in raw materials, but also uses a flow casting method, which can be applied to industrial production and has a good application prospect.

The invention belongs to the technical field of food packaging materials and bacteriostatic packaging films, and discloses an active packaging film capable of generating singlet oxygen bacteriostasis based on light driving, a preparation method and application of the active packaging film in fresh keeping of fruits, vegetables and edible mushrooms, and the active packaging film comprises the following steps: S1, obtaining a chitosan film solution A for later use; s2, obtaining a polyvinyl alcohol membrane solution B for later use; s3, obtaining a polyvinyl alcohol / chitosan composite membrane solution D based on food-grade nano silicon dioxide loaded sodium copper chlorophyllin; s4, preparing the bacteriostatic active packaging film, and using the bacteriostatic active packaging film in combination with blue-violet light. The antibacterial film disclosed by the invention has the advantages of high barrier property, ultraviolet-resistant optical property, strong and flexible mechanical property, good thermal stability, biodegradability and antibacterial property of CD-ROM movable product singlet oxygen (1O2). The packaging film can be used as a bio-based active package, can reduce the environmental pollution of a traditional petroleum-based packaging film, can prolong the shelf life of fruits, vegetables and edible mushrooms, and has the dual effects of environmental protection, bacteriostasis and preservation.

The utility model relates to the technical field of band-aids, and discloses a band-aid containing dehydrated gel and a chitosan protective film, which comprises a non-woven fabric body, two viscose layers and a dehydrated gel layer are arranged at the top end of the non-woven fabric body, the two viscose layers are respectively positioned on two sides of the dehydrated gel layer, and the dehydrated gel layer is positioned on the bottom end of the non-woven fabric body. A chitosan film covers the top end of the dehydrated gel layer, an anti-sticking layer is stuck to the top end of the adhesive layer, and connecting paper is fixedly connected to the corner position of the side, close to the chitosan film, of the anti-sticking layer. According to the technical scheme, through the arrangement of the connecting paper, a user can directly tear down the anti-sticking layer from the adhesive layer under the condition that the user does not make contact with the chitosan film, the user can tear down the anti-sticking layer by means of force, meanwhile, the anti-skid protruding blocks can improve the anti-skid performance of the connecting paper, the use experience of the user is improved, and the use experience of the user is improved. The practicability is high.

The present invention relates to an optical fiber sensor for detecting lead ions in industrial wastewater from battery production, which is composed of a multimode optical fiber, a coreless optical fiber, a microsphere, a chromium film, a silver film, and a modified chitosan film. The end face of the coreless optical fiber is processed into a microsphere shape, and the surface of the coreless optical fiber is successively coated with a chromium film, a silver film, and a modified chitosan film to form an optical fiber cladding. The present invention utilizes the adsorption of lead ions in industrial wastewater from battery production by the modified chitosan film, which causes a change in the refractive index of the modified chitosan film layer, and further leads to a change in the wavelength of the SPR signal loss peak. By analyzing the wavelength of the SPR signal, the detection of lead ion concentration is realized, meeting the actual requirements for the detection of heavy metal ions. The preparation method of the present invention uses simple equipment, steps, and processes, can effectively excite the SPR signal, realize the high-sensitivity and high-precision detection of lead ions, and effectively evaluate the pollution situation of lead ions in industrial wastewater from battery production.

The invention discloses functional nano zinc oxide as well as a preparation method and application thereof, and belongs to the technical field of food packaging materials and functional nano composite materials. The preparation method comprises the following steps: dissolving dialdehyde cellulose in a hydrochloric acid solution, mixing with a procyanidine solution dissolved in DMSO (Dimethylsulfoxide), heating to react, dialyzing and drying to obtain a cellulose-polyphenol graft; and uniformly mixing the cellulose-polyphenol graft aqueous solution with a zinc nitrate aqueous solution, adjusting the pH value, carrying out a hydrothermal reaction, carrying out centrifugal separation, washing the precipitate, and drying to obtain the functional zinc oxide nanoparticles. Through an aldehyde cellulose-polyphenol grafting strategy, the particle size controllability and dispersity of ZnO nano particles are improved, the ZnO nano particles are endowed with higher specific surface area and functionality, and after the ZnO nano particles are loaded to a chitosan film, the oxidation resistance, antibacterial property and mechanical strength of the film are remarkably enhanced.

This invention discloses a topologically oriented cyclodextrin / chitosan composite membrane, its preparation method, and its applications, belonging to the field of bio-based nanomaterials technology. Using α-cyclodextrin and polyethylene glycol (PEG) as raw materials, this invention prepares topologically oriented cyclodextrin-PEG "ring-slippery" nanoparticles (TNPs). TNPs, as green and biodegradable nanoparticles, fill the chitosan network matrix, enhancing hydrogen bonding interactions with chitosan molecules and improving the mechanical properties of the chitosan membrane. This method not only uses simple raw materials and is easy to implement, but also effectively improves the mechanical strength of the chitosan composite membrane, effectively overcoming the problem of poor mechanical strength in existing chitosan composite membranes, and providing a simple and effective approach for practical production.

The invention discloses a highly efficient composite steel dust and mud washing solution treatment agent, belonging to the technical field of wastewater treatment. The treatment agent raw materials provided by the present invention include: 30-60 parts of sodium hydroxide, 30-60 parts of sodium carbonate, 0.45-0.9 parts of potassium ferrate and 12-16 parts of chitosan-coated loaded calcium peroxide tourmaline. The chitosan-coated loaded calcium peroxide tourmaline is based on tourmaline powder, loaded with calcium peroxide, and coated with a gel solution formed by chitosan to obtain a chitosan film coating layer, which is added to the washing solution. Chitosan can ensure the dispersibility of the loaded calcium peroxide tourmaline while adsorbing heavy metal ions. Calcium peroxide reacts with water, promotes the oxidation of heavy metals on the one hand, forms hydroxide precipitation, and locally releases heat on the other hand to produce a self-polarization effect of tourmaline, further improving adsorption performance. The purification treatment of the washing solution is realized under the synergistic effect of the multiple components of the treatment agent, simplifying the process flow.

The invention provides chitosan-coated zeolite with liquid blocking and ventilating functions as well as a preparation method and application thereof, and relates to the technical field of enhanced mass transfer of equipment for adsorption heat exchange. According to the invention, a film coating technology and an adsorption technology are combined, the surface of 13X zeolite is coated with a layer of liquid-resistant breathable film-chitosan film, and vinyl trimethoxy silane is adopted to carry out chemical crosslinking on the chitosan film, so that the pore size and distribution of the chitosan film are regulated and controlled, and liquid free water in a system is regulated and controlled. The coated zeolite prepared by the invention has excellent liquid resistance, reduces the content of free water in a bed layer so as to enhance the overall performance and efficiency of a system, and is more suitable for being applied to a direct contact type adsorption heat pump system.

The invention discloses a chitosan / diatomite coated biochar-based slow release fertilizer and a preparation method and application thereof, and the preparation method comprises the following steps: firstly, mixing biochar, urea and corn starch according to a specific ratio, granulating to prepare a fertilizer core, and then carrying out coating treatment on the fertilizer core by taking a chitosan solution / diatomite as a coating liquid. By adding the diatomite, the mechanical property and swelling property of the chitosan film are improved, and the chitosan film, the diatomite and the biochar have a synergistic effect to delay nutrient release. The fertilizer is simple in preparation process, low in cost and environment-friendly, can remarkably improve the nutrient utilization rate and the crop yield, has the effect of improving saline-alkali soil, and is suitable for green development of agriculture.

The preparation method comprises the following steps: S1, adding a certain amount of tin-doped indium oxide and carbon nanotubes into an aqueous solution containing aniline and hydrochloric acid, carrying out ultrasonic dispersion for 1-2 hours, then adding ammonium persulfate, and carrying out a reaction for a certain time, so as to obtain a solution A; centrifuging, washing and drying to obtain polyaniline modified carbon nanotubes and tin-doped indium oxide particles; s2, mixing polyaniline modified tin-doped indium oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water, mechanically stirring and uniformly dispersing, then performing ultrasonic treatment to remove bubbles, pouring a film forming solution into a polytetrafluoroethylene mold for tape casting, and then putting the film forming solution into a drying oven for treatment to obtain the antibacterial flame-retardant infrared stealth functional chitosan film. According to the invention, by means of the synergistic effect among the carbon nanotubes, the tin-doped indium oxide, the polyaniline and the chitosan, the chitosan film has extremely low infrared emissivity, and a good infrared stealth effect is achieved.

The present application discloses a chitosan porous membrane and its preparation method and application. The present application utilizes the processes of electrospinning, urushiol cross-linking, and swelling to prepare a porous chitosan membrane with a nanoscale pore structure. By introducing oligomeric urushiol, a structure is constructed with chitosan molecules that are easily soluble in a swelling agent solution as the main chain and acid-resistant and hydrophobic polymeric urushiol as the cross-linking bridge. This allows for slow and controllable swelling of chitosan nanofibers, solving the problem of precise and effective control of the pore size and structure of the chitosan membrane. Furthermore, the nanofiber swelling process is utilized to transform the disordered stacked nanofiber precursors formed by electrospinning into a cross-fused continuous network, thereby forming a continuous porous membrane with high strength.

The invention belongs to the technical field of fruit and vegetable fresh-keeping, and particularly relates to a fruit and vegetable fresh-keeping agent and a preparation method and application thereof. The invention provides a fruit and vegetable fresh-keeping agent. The fruit and vegetable fresh-keeping agent comprises the following components in percentage by volume of a solvent: 1%-4% of chitosan, 1%-5% of acetic acid, 0.5%-1.2% of glycerol and 0.2%-0.5% of bacteriostatic plant hydrolat. Wherein the chitosan can form a layer of colorless and transparent protective film on the surfaces of fruits and vegetables to prolong the after-ripening period of the fruits and vegetables, the chitosan has a good effect of inhibiting and killing bacteria, and the acetic acid can promote dissolution of the chitosan, so that the chitosan is easy to form a film on the surfaces of the fruits and vegetables after being dissolved; glycerol can maintain the stability of the chitosan film; the bacteriostatic plant hydrolat has a bacteriostatic effect and can kill microorganisms on fruits and vegetables. Results of the embodiment show that the fruit and vegetable fresh-keeping agent can effectively reduce the rotting rate of fruits and vegetables in the fresh-keeping process.

The invention relates to the technical field of plastics, and particularly discloses a modified PP composite material for a wear-resistant cosmetic packaging bottle and a preparation method of the modified PP composite material. According to the modified PP composite material for the wear-resistant cosmetic packaging bottle, 3-(2-aminoethylamino) propyltrimethoxysilane is adopted to modify nano aluminum oxide and nano silicon dioxide, then the modified nano aluminum oxide and nano silicon dioxide, a lubricant and polypropylene are subjected to extrusion and injection molding through an extensional rheology extruder, then the inner surface of the PP bottle is modified through caffeic acid, and the modified PP composite material for the wear-resistant cosmetic packaging bottle is obtained. And then alternately assembling the sodium alginate film and the chitosan film. Finally, the modified PP composite material for the wear-resistant cosmetic packaging bottle is obtained. The prepared modified PP composite material for the wear-resistant cosmetic packaging bottle has the characteristics of high bending strength, high tensile strength, excellent impact strength, good wear resistance and scratch resistance and strong oxidation resistance, and is suitable for cosmetic packaging.

The invention discloses an efficient composite steel dust mud water washing solution treatment agent, and belongs to the technical field of wastewater treatment. The treatment agent provided by the invention is prepared from the following raw materials: 30 to 60 parts of sodium hydroxide, 30 to 60 parts of sodium carbonate, 0.45 to 0.9 part of potassium ferrate and 12 to 16 parts of chitosan-coated calcium peroxide-loaded tourmaline. According to the chitosan-coated calcium peroxide-loaded tourmaline, tourmaline powder serves as a base material, calcium peroxide is loaded, a chitosan film coating layer is obtained after coating is conducted through gel liquid formed by chitosan, the chitosan film coating layer is added into a washing solution, the chitosan can adsorb heavy metal ions, meanwhile, the dispersity of the calcium peroxide-loaded tourmaline is guaranteed, calcium peroxide reacts when meeting water, and therefore the heavy metal ions can be effectively adsorbed. On one hand, oxidation of heavy metals is promoted to form hydroxide precipitates, on the other hand, local heat release enables tourmaline to generate a self-polarization effect, and the adsorption performance is further improved. Under the synergistic effect of various components of the treatment agent, purification treatment of the washing solution is achieved, and the technological process is simplified.

This invention provides a method for preparing a chitosan membrane, the chitosan membrane prepared by this method, and its applications. The method includes the following steps: S1: mixing chitosan, acid, C1-C6 monohydric alcohol, pore-forming agent, metal salt, and water to obtain a casting solution; S2: placing the casting solution on a carrier to obtain a carrier loaded with the chitosan membrane; S3: immersing the carrier loaded with the chitosan membrane sequentially in an alkaline solution and water to separate the chitosan membrane from the carrier. The chitosan membrane of this invention has a strong resistance to strong alkalis. When used as an anion exchange membrane material in fuel cells, it has advantages such as high specific power, rapid start-up, non-corrosiveness, low reaction temperature, and low oxidant requirement.

The invention relates to the technical field of biological catalysis, in particular to a preparation method and application of a co-immobilized enzyme based on macroporous resin adsorption-chitosan membrane coating, and the preparation method mainly comprises the following steps: pretreating resin, adding glucose oxidase and catalase, fully adsorbing, and coating with a chitosan membrane to obtain the co-immobilized enzyme, the method can be used for producing gluconic acid. The co-immobilized enzyme prepared by the invention has the characteristics of adaptation to low-pH production, high enzyme activity retention rate and the like.

The present invention discloses a polyethylene filter membrane for homogenizing bags and a preparation method thereof, relating to the field of new materials technology. The polyethylene filter membrane for homogenizing bags produced in the present invention is made by attaching a modified phospholipid to a composite polyethylene filter membrane. The composite polyethylene filter membrane is formed by laminating an irradiated polyethylene filter membrane with a thiol chitosan membrane, thereby enhancing the mechanical properties of the filter membrane. The modified phospholipid is obtained by first epoxidizing soybean phospholipid and then reacting it with a terpolymer through a ring-opening reaction. The terpolymer is obtained by introducing hydroxyl-terminated polybutadiene to both ends of polyvinyl alcohol. The epoxy rings on the epoxidized soybean phospholipid can undergo a ring-opening reaction with the terpolymer, introducing both hydroxyl groups and amphiphilic long chains of the terpolymer, thereby improving the hydrophilicity of the filter membrane and enhancing its stability.

This invention relates to the field of fruit preservation technology and discloses a method for preserving mangoes containing chitosan, a eutectic solvent, and EGC. The method includes the following steps: adding chitosan to an acetic acid solution and heating and stirring in a water bath to obtain a chitosan film solution; pre-dispersing and wetting epigallocatechin in a eutectic solvent, then adding it to the aforementioned chitosan film solution and stirring at room temperature to obtain a modified chitosan composite film solution; selecting undamaged mangoes, washing and air-drying their surface moisture, immersing them in the modified chitosan composite film solution to evenly coat the surface with the film solution, removing them and air-drying them naturally, repeating the aforementioned immersion and air-drying process, and finally storing the dried mangoes in an indoor environment for preservation. This invention utilizes a eutectic solvent to solve the problem of easy aggregation of polyphenolic active substances, forming a uniform and continuous semi-permeable membrane on the mango peel, limiting moisture loss, achieving slow release of antioxidant components, and significantly extending the mango's shelf life.

The application discloses a preservative film liquid, a preservative film and a preparation method and application thereof in berry preservation, and relates to the technical field of food preservation. The preservative film liquid comprises a self-assembled nanoparticle with a melatonin core and a PEG-40 hydrogenated castor oil shell and a chitosan dispersion liquid, wherein the mass ratio of the PEG-40 hydrogenated castor oil to the melatonin is 0.25:1.2-1.6. The application also provides a preparation method of the preservative film liquid, a preservative film prepared by the preservative film liquid and application thereof in berry preservation. The application loads the melatonin in the chitosan film and overcomes the negative influence of the melatonin on the performance of the chitosan film material, so that the preservative film has good mechanical performance, barrier performance and continuous preservation function, and has important significance for the preservation of perishable foods such as berries.