CN115918714A - Fresh-keeping cold catalyst material and preparation method and application thereof - Google Patents
Fresh-keeping cold catalyst material and preparation method and application thereof Download PDFInfo
- Publication number
- CN115918714A CN115918714A CN202211460159.2A CN202211460159A CN115918714A CN 115918714 A CN115918714 A CN 115918714A CN 202211460159 A CN202211460159 A CN 202211460159A CN 115918714 A CN115918714 A CN 115918714A
- Authority
- CN
- China
- Prior art keywords
- fresh
- catalyst material
- keeping
- source
- cold catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Landscapes
- Catalysts (AREA)
Abstract
The invention discloses a fresh-keeping cold catalyst material and a preparation method thereof, wherein a clay mineral is used as a template carrier, a cryptomelane type crystal structure zinc-titanium composite oxide with silver doped in a loading pore channel is used as a matrix, and a copper ion antibacterial agent is loaded as an active component. The dispersion with the particle size of 30-200 nm is obtained by utilizing the energy provided by high temperature, high pressure and ultrasonic waves, the obtained substance has remarkable bacteriostatic effect on staphylococcus aureus, escherichia coli, aspergillus niger, bacillus subtilis and the like, the adsorption and decomposition rate on ethylene is increased from 20% to about 80% within 5 min-12 h, and most harmful gases of ethylene can be removed. The invention also discloses the fresh-keeping cold catalyst material and the application thereof in fresh-keeping packaging materials of fruits, vegetables and cold fresh meat products. The fresh-keeping cold catalyst material can be prepared into fresh-keeping coating paper, or can be added into a packaging film or a tray as functional particles, and is used for fresh-keeping packaging of fruits, vegetables and cold fresh meat products.
Description
Technical Field
The invention belongs to the technical field of food fresh-keeping materials, and particularly relates to a fresh-keeping cold catalyst material and a preparation method and application thereof.
Background
With the development of social economy, the improvement of the living standard of people and the acceleration of the pace of urban life, the improvement of the attention degree of people to self health and diet quality, and various pure natural fresh fruits and vegetables with low processing degree are more and more favored by people.
The fresh fruits and vegetables are different from common industrial products and have the following characteristics: (1) the pH of the product is >4.6; (2) water activity aw >0.85; (3) without heat treatment or other treatment: (4) There are no other hurdles such as preservatives, acidulants, etc. These characteristics make it extremely vulnerable or toxic in the absence of hypothermia. The food is difficult to store at normal temperature, the original freshness and quality are not easy to maintain, the nutrition and edible value are easy to lose after the food is placed for a short time, and the food is easy to decay and pollute, so that huge waste is caused, and hidden dangers of food safety exist. The main causes of the deterioration of the fresh fruits and vegetables are ethylene gas, microorganisms (including pathogenic bacteria and putrefying bacteria) and other factors.
The packaging, storage and transportation technology in the circulation process of the products is particularly important and becomes one of the most basic factors for ensuring the quality and safety of the products. Until now, the related research of the fresh-keeping packaging new material technology at home and abroad is still in the process of fire heating, for example, CN202010402771.9 discloses a preparation method of a photocatalyst fresh-keeping plastic film and a method thereof, which realize coordination removal of ethylene and sterilization of cells by using functional components such as photocatalyst, potassium permanganate and the like. The disadvantages of this type of method are mainly: one is easily limited by insufficient light source, so that the protective effect of the functional material on fruits and vegetables is lost in a dark environment, and the potassium permanganate exposed on the surface of the film possibly influences some organoleptic properties and safety of the product. However, in the art, better incorporation of functional ingredients into materials by supported forms and incorporation into polymer films has been the direction of development of new functional packaging, and currently, many of these products have gained market acceptance. The development of a fresh-keeping functional material which has broad-spectrum antibacterial property, can adsorb and decompose harmful gases such as ethylene and the like, is safe and nontoxic, and can regulate and control a packaging microenvironment is important from the aspect of materials science, particularly under the environment of refrigeration and electricity commercial storage and transportation.
Disclosure of Invention
The invention aims to provide a preparation method of a fresh-keeping cold catalyst material, the cold catalyst material prepared by the method is not influenced by environmental factors such as illumination, temperature and the like, has the effects of adsorbing and removing harmful gases such as ethylene and the like and a better antibacterial effect, and is safe and environment-friendly.
The invention also aims to provide the fresh-keeping cold catalyst material prepared by the method.
The last purpose of the invention is to provide the application of the fresh-keeping cold catalyst material in fresh-keeping packaging materials of fruits, vegetables and cold fresh meat products.
The first object of the present invention can be achieved by the following technical solutions: a preparation method of a fresh-keeping cold catalyst material comprises the following steps:
(1) Dispersing clay minerals in an organic solvent, and uniformly stirring to obtain clay mineral dispersion liquid;
(2) Adding a silver source, a potassium source, a manganese source, a zinc source, a titanium source and a dispersing agent into the clay mineral dispersion liquid, uniformly stirring, and calcining at 475-485 ℃ for 8-24 hours under 183-207 kPa to obtain a silver-doped cryptomelane type zinc-titanium composite oxide with a pore passage taking a clay mineral as a carrier;
(3) And (3) uniformly mixing the copper ion antibacterial agent and the dispersing agent to obtain a copper ion antibacterial agent dispersion liquid, adding the copper ion antibacterial agent dispersion liquid into the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with the clay mineral as the carrier prepared in the step (2), mixing and stirring for 6-24 hours in an ultrasonic device at 15-65 ℃, and drying to obtain a dispersion, namely the fresh-keeping cold catalyst material.
In the preparation method of the fresh-keeping cold catalyst material, the steps of:
preferably, in the step (1), the clay mineral is one or more of kaolin, vermiculite, silica and diatomite, and the organic solvent is absolute ethyl alcohol and glacial acetic acid.
The clay mineral used as the carrier in the invention has active cation exchange and gas adsorption functions, and self-assembly, porosity, good biocompatibility and physical properties of the clay mineral provide good guarantee for the construction of the nano-scaffold. The interlayer bonding force of the clay mineral is weak due to the laminated structure of the clay mineral, the layering of the internal structure of the material is easy to occur when the clay is dispersed in a solvent, interlayer gaps are generated, the laminated particles are newly bonded and reconstructed to form a 'cabin' structure, different materials are favorably compounded, and therefore a new structure and a new function are obtained. And the clay mineral can form more fiber net structures after being compounded with the nano material, so that larger specific surface area is obtained, the water dispersibility of the material is improved, and the casting film forming of the material is facilitated. After being combined with silver-doped cryptomelane type zinc-titanium composite oxide (ZnTi), the composite oxide can realize the continuous synergistic effect of the adsorption of the former and the decomposition of the latter.
Preferably, the rotation speed during stirring in steps (1) to (2) is 2000 to 4500r/min.
Preferably, in the step (2), the silver source is silver-loaded titanium dioxide, the potassium source is potassium permanganate or potassium chloride, the manganese source is potassium permanganate, the zinc is zinc oxide, the titanium source is titanate, rare earth aluminate titanium dioxide, titanium dioxide powder or silver-loaded titanium dioxide, and the dispersing agent is phthalimide and/or vinyl acetate resin.
Preferably, in the step (2), the mass parts of the clay mineral, the silver source, the potassium source, the manganese source, the zinc source and the titanium source are as follows: 45 to 80 percent of clay mineral, 2 to 5 percent of silver source, 2 to 5 percent of potassium source, 2 to 5 percent of manganese source, 4 to 15 percent of zinc source and 10 to 25 percent of titanium source.
Preferably, the chemical general formula of the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide in the pore channel in the step (2) is as follows: ag x (A) y [M z Ti 8-z ]O 16 Wherein M = Mn 2+ 、Zn 2+ ，A＝K + 、H + (H + The clay mineral contains abundant hydroxyl groups and a large amount of hydrogen elements); x is less than or equal to 2; y is less than or equal to 2; z is less than or equal to 3, [ M ] z Ti 8-z ]O 16 Represents the framework composition of a cryptomelane type crystal structure zinc-titanium composite oxide with silver doped pore channels, and Ag x (A) y Showing the composition of the pore canal of the cryptomelane type crystal structure zinc-titanium composite oxide with the pore canal doped with silver.
After the cryptomelane type crystal structure zinc-titanium composite oxide (ZnTi) with silver doped in a pore channel is loaded on a clay carrier, the zinc-titanium composite oxide is not influenced by environmental factors such as illumination, temperature and the like, metal molecules such as molecular titanium, molecular silver and the like in the zinc-titanium composite oxide continuously and unstably excite a trace of fluid molecules, and simultaneously can generate impurities with energy levels between a conduction band and a valence band, so that after electrons in the valence band are transferred to the conduction band, the electrons loaded in the conduction band and positive holes in the valence band are difficult to recombine to generate electron-hole pairs, and oxidation-reduction reactions are respectively carried out, and the effects of adsorbing and removing ethylene and other harmful gases are achieved.
Preferably, the copper ion antibacterial agent in step (3) is selected from copper sulfate, copper acetylacetonate, nano copper oxide, copper hydroxide, cuprous oxide, copper chloride, copper acetate, copper amino acid, copper humate, copper rosinate, copper succinate or copper ammine complex.
Preferably, the dispersant in the step (3) is phthalimide and/or vinyl acetate resin; the mass part ratio of the copper ion antibacterial agent to the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with the duct taking the clay mineral as the carrier is 2-4: 20 to 55.
The clay mineral has rich positive and negative charges, contains rich amino, hydroxyl, carboxyl and other groups, is beneficial to regular arrangement of copper ions, and plays a better antibacterial and antibacterial effect. The antibacterial synergistic effect can be obtained by combining the active components of the copper ion antibacterial agent, so that a better antibacterial effect is obtained. It is worth noting that the clay mineral and the cryptomelane type crystal structure zinc-titanium composite oxide (ZnTi) with the silver-doped pore channel do not migrate after reaction, and can be used in the packaging industry of food preservation.
Preferably, the frequency of the ultrasonic equipment in the step (3) is 15-25 kHz.
Preferably, the particle size of the dispersion in step (3) is in the range of 30 to 200nm.
Preferably, the fresh-keeping cold catalyst material in the step (3) is a combination of a cryptomelane type crystal structure zinc-titanium composite oxide with a pore channel doped with silver and a copper ion antibacterial agent, wherein the clay mineral is used as a carrier.
The combination of the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with the pore channel taking the clay mineral as the carrier and the copper ion antibacterial agent has both surface activity characteristic and antibacterial property, and utilizes the energy provided by heating and ultrasonic wave to accelerate the intermolecular thermal motion and enlarge the interlayer spacing of the clay carrier, so that the structure is more loose, and the specific surface area is increased; the copper ion antibacterial functional components are embedded in the interlayer inside and outside the clay carrier more conveniently; meanwhile, the larger surface area in the clay mineral layer is sufficient space for adsorbing and decomposing free ethylene in the air and inhibiting the growth and release of bacteria.
The second objective of the present invention can be achieved by the following technical solutions: a fresh-keeping cold catalyst material is prepared by the method.
The invention provides a fresh-keeping cold catalyst material for packaging, which is green, efficient and environment-friendly, can ensure the safety and freshness of fruits, vegetables and cold fresh meat products and prolong the shelf life of the fruits, vegetables and cold fresh meat products.
The third object of the present invention can be achieved by the following technical solutions: the application of the fresh-keeping cold catalyst material in fresh-keeping packaging materials for fruits, vegetables and cold fresh meat products.
Preferably, the cold catalyst material is applied to paper by coating or coating and used as a freshness protection package material.
Preferably, the cold catalyst material is added into a plastic product as an effective particle to be used as a fresh-keeping packaging material.
Preferably, the plastic product is a packaging film or a tray.
The fresh-keeping cold catalyst material suitable for packaging has broad-spectrum antibacterial property and the functions of dynamically adsorbing and decomposing organic gases such as ethylene, histamine and the like. The method adopts clay minerals as a template carrier, adopts cryptomelane type crystal structure zinc-titanium composite oxides (ZnTi) with silver-doped loading pore channels as a matrix, and then loads a copper ion antibacterial agent as an active component. The high temperature, high pressure and ultrasonic energy are utilized to obtain the dispersion with the particle size of 30-200 nm, the obtained substance has obvious bacteriostatic effect on staphylococcus aureus, escherichia coli, aspergillus niger, bacillus subtilis and the like, and the adsorption and decomposition rate of ethylene and histamine is 20-80%. The fresh-keeping cold catalyst material can be prepared into fresh-keeping coating paper, or can be added into a packaging film or a tray as an effect particle for fresh-keeping packaging of fruits, vegetables and cold fresh meat products.
Compared with the prior art, the invention has the following advantages:
(1) The invention combines the characteristics of multiple loaded antibacterial ions, has the characteristics of high efficiency, broad spectrum, stability and the like, has obvious bacteriostatic effect on putrefying bacteria such as staphylococcus aureus, escherichia coli, aspergillus niger, bacillus subtilis and the like, has the characteristics of good heat resistance, wide antibacterial spectrum, long effective antibacterial period, low toxicity, no generation of drug resistance and high safety by loading a plurality of metal ions on the surface of clay, and causes the death or the loss of the division and proliferation capacity of microorganisms mainly by destroying the protein active center of the bacteria; the antibacterial agent has the characteristics of an organic antibacterial agent, can enter cells by combining with anions on the surface of a microbial cell membrane or react with groups such as sulfydryl on the surface of the cells to destroy structures such as protein and nucleic acid of the microbes, and destructively damage physiological systems such as an enzyme system and the like, thereby realizing the high-efficiency antibacterial effect.
(2) The zinc-titanium compound cold catalyst can also play a good catalytic activity under the conditions of weak light and even darkness, and continuously forms free electrons and holes on the surface of clay and O adsorbed on the surface of the clay 2 And H 2 O function, form superoxide free radical, free radical will stop producing continuously after reaching coordination saturation, and because decompose ethylene and kill bacterium and lead to the free radical to reduce, will stimulate the zinc-titanium complex to continue producing the free radical, the hydroxide radical has powerful oxidative decomposition ability, it can decompose nearly all organic compounds and a part of inorganic substance, decompose them into non-toxic carbon dioxide and water; the negative electrons and oxygen are combined into active oxygen, namely super oxide ions, which have strong oxidative decomposition capability, can destroy cell membranes of bacteria, solidify proteins of the bacteria, and decompose harmful compounds released from bacterial corpses while killing the bacteria.
(3) The zinc-titanium compound cold catalyst can excite free electrons to generate free radicals under the normal temperature environment, further induce redox reaction, realize the adsorption and decomposition of harmful gases such as ethylene generated by food, increase the adsorption and decomposition rate of the harmful gases such as ethylene from 20% to about 80% within 5 min-12 h, and remove most of the harmful gases such as ethylene, thereby ensuring the freshness of the food.
(4) The clay mineral is used as a gas adsorption carrier, so that the humidity and the concentrations of carbon dioxide and oxygen in the surrounding environment can be adjusted in the fruit and vegetable fresh-keeping process, and the respiration of the fruits and vegetables is further reduced; meanwhile, the fruit and vegetable preservative can adsorb ethylene and other harmful gases, reduce the ethylene concentration and the bad smell in the surrounding environment and ensure the freshness of fruits and vegetables.
(5) The preparation method of the fresh-keeping cold catalyst material has simple process and low raw material price, and the application of the fresh-keeping cold catalyst material can ensure the safety and freshness of fruits and vegetables to the maximum extent and prolong the shelf life of foods.
(6) The application of the fresh-keeping cold catalyst material in the invention accords with the leading direction of chemical preservative reduction and harm control, cost saving and efficiency improvement, and food safety and healthy agriculture development, also provides a new method for upgrading food fresh-keeping technology, and has great economic benefit and social benefit.
Drawings
FIG. 1 is a scanning electron microscope image of kaolin and a fresh-keeping cold catalyst material in example 1, wherein the left image is a scanning electron microscope structural diagram of kaolin; the right picture is the electron microscope scanning structure picture of the prepared fresh-keeping cold catalyst material;
FIG. 2 shows the bacteriostatic effects of Escherichia coli of the conventional food preservative material and the cold-catalyst material prepared according to the present invention in example 4, wherein the left graph shows the bacteriostatic effect of a common copper ion antibacterial agent in Escherichia coli, and the right graph shows the bacteriostatic effect of the cold-catalyst material according to the present invention in Escherichia coli;
fig. 3 shows the bacteriostatic effect of staphylococcus aureus of the traditional food preservation material and the cold catalyst material prepared by the invention in example 4, wherein the left graph shows the bacteriostatic effect of a common copper ion antibacterial agent in staphylococcus aureus, and the right graph shows the bacteriostatic effect of the cold catalyst material prepared by the invention in staphylococcus aureus;
fig. 4 is the aspergillus niger bacteriostatic effect of the traditional food fresh-keeping material and the cold-catalyst material prepared by the present invention in example 4, wherein the left graph is the bacteriostatic effect of a common copper ion antibacterial agent in aspergillus niger, and the right graph is the bacteriostatic effect of the cold-catalyst material of the present invention in aspergillus niger;
FIG. 5 shows the bacteriostatic effects of Bacillus subtilis in the conventional food fresh-keeping material and the cold-catalyst material prepared according to the present invention in example 4, wherein the left graph shows the bacteriostatic effect of a common copper ion antibacterial agent in Bacillus subtilis, and the right graph shows the bacteriostatic effect of the cold-catalyst material according to the present invention in Bacillus subtilis;
FIG. 6 shows the results of the ethylene removal performance test of the fresh keeping material of example 4 using the fresh keeping cold catalyst material of example 1;
FIG. 7 shows the photocatalytic performance of the fresh keeping material of example 4, which is made of the fresh keeping cold catalyst material of example 1;
FIG. 8 is a test of the preservation effect of the plastic film made of the preservation cold catalyst material in example 1 on waxberries in example 4.
Detailed Description
The technical solutions of the present invention are described in detail by the following examples, which are merely exemplary and can be used to explain and illustrate the technical solutions of the present invention, but should not be construed as limiting the technical solutions of the present invention. The following raw materials are all commercially available products or prepared by conventional methods in the art, unless otherwise specified.
Example 1
The preparation method of the fresh-keeping cold catalyst material provided by the embodiment comprises the following steps:
(1) Dispersing 65g of kaolin into 164mL of 95% (v/v) absolute ethanol and 2mL of glacial acetic acid, and uniformly stirring at 2000r/min to obtain a kaolin dispersion liquid;
(2) Then adding 2g of silver-loaded titanium dioxide (or silver-loaded titanium dioxide), 2g of potassium permanganate, 4g of nano zinc oxide, 5g of titanate, 2g of rare earth aluminate titanium dioxide, 2g of titanium dioxide powder, 1mL of vinyl acetate resin and the like into kaolin dispersion liquid, fully stirring at the rotating speed of 2000r/min, and then calcining at 480 ℃ and 198kPa for 24 hours to obtain a silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with a pore passage taking clay minerals as a carrier, wherein the mixture is called A for short;
(3) At normal temperature, 2g of copper sulfate, 5mL of vinyl acetate resin and 10mL of phthalimide are mixed to obtain copper sulfate dispersion liquid, called mixed liquid B for short, the mixed liquid B is mixed into the prepared mixture A in a drop manner of about 5s and 1 drop, energy is provided by ultrasonic oscillation and heating of 20kHz in an ultrasonic instrument (with the frequency of 20 kHz) at 45 ℃ for mixing and stirring for 6h, and after drying for 24h at 65 ℃, dispersion with the average particle size of about 100nm is obtained, namely the fresh-keeping cold catalyst material.
The scanning electron microscope image of the fresh-keeping cold catalyst material prepared in example 1 is shown in fig. 1, and it can be seen from the result of the electron microscope scanning of fig. 1 that: the novel material prepared by the invention is in a spherical multilayer structure, compared with the original kaolin multilayer plane structure, the novel material structure is more loose, more compact spherical structures are born, and the molecular thermal motion between the original composite oxide and the clay is accelerated under the action of heating and ultrasonic energy, so that molecular pore channels with more surface areas are generated.
Example 2
The preparation method of the fresh-keeping cold catalyst material provided by the embodiment comprises the following steps:
(1) Dispersing 75g of vermiculite in 164mL of 50% (v/v) absolute ethanol and 2mL of glacial acetic acid, and uniformly stirring to obtain a vermiculite dispersion liquid;
(2) Then adding 4g of silver-loaded titanium dioxide, 4g of potassium permanganate, 4g of nano zinc oxide, 4g of rare earth aluminate titanium dioxide, 10g of titanate, 4g of titanium dioxide powder, 2mL of vinyl acetate resin and the like into the vermiculite dispersion liquid, fully stirring at the rotating speed of 2000r/min, and then calcining at 480 ℃ and 198kPa for 24 hours to obtain a silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with a pore passage taking clay minerals as a carrier, wherein the mixture is called A for short;
(3) Mixing 4g of copper acetylacetonate, 5mL of vinyl acetate resin and 10mL of phthalimide at normal temperature to obtain copper acetylacetonate dispersion liquid, called mixed liquid B for short, mixing the mixed liquid B into the prepared mixture A by about 5s of 1 drop, providing energy by 20kHz ultrasonic vibration and heating in 20kHz ultrasonic equipment at 45 ℃ for mixing and stirring for 6h, and drying at 65 ℃ for 24h to obtain dispersion with the average particle size of about 150nm, namely the fresh-keeping cold catalyst material.
Example 3
The preparation method of the fresh-keeping cold catalyst material provided by the embodiment comprises the following steps:
(1) Dispersing 50g of a mixture of silicon dioxide and diatomite in 164mL of 50% (v/v) absolute ethanol and 2mL of glacial acetic acid, and uniformly stirring at the rotating speed of 2000r/min to obtain a dispersion liquid of the mixture of silicon dioxide and diatomite;
(2) Adding 4g of silver-loaded titanium dioxide, 4g of potassium permanganate, 4g of nano zinc oxide, 8g of titanate, 4g of rare earth aluminate titanium dioxide, 4g of titanium dioxide powder, 2mL of vinyl acetate resin and the like into a dispersion liquid of a mixture of silicon dioxide and diatomite, fully stirring at the rotating speed of 2000r/min, and then calcining at 480 ℃ and 198kPa for 24 hours to obtain a silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with a pore passage taking clay minerals as a carrier, wherein the mixture is called A for short;
(3) Mixing 2g of nano copper oxide, 4mL of vinyl acetate resin and 8mL of phthalimide at normal temperature to obtain a nano copper oxide dispersion liquid, namely a mixed liquid B for short, mixing the mixed liquid B into the prepared mixture A by about 5s of 1 drop, mixing and stirring for 6 hours at 45 ℃ in 20kHz ultrasonic equipment by using energy provided by heating and ultrasonic waves, and drying for 24 hours at 65 ℃ to obtain a dispersion with the average particle size of about 50nm, namely the fresh-keeping cold catalyst material.
Example 4
The fresh-keeping cold catalyst material of example 1 was used in the antibacterial and ethylene scavenging tests as follows:
(1) Antibacterial experiments
(1) Firstly, preparing a solid culture medium, inoculating, preparing a liquid culture medium, and preparing a bacterial suspension.
(2) Taking the test tube and marking, putting the test tube, the rubber stopper, the gun head and the like into an autoclave, and sterilizing for 20-30 minutes at 121 ℃.
(3) On a clean bench, the fresh-keeping cold catalyst material of example 1 (copper ion antibacterial agent copper sulfate of example 1 is used as a reference) is weighed in beakers, mixed with absolute ethyl alcohol of the same mass, stirred fully, 4 pieces of drug sensitive paper are put in each beaker, covered with tin foil paper, and soaked for 30 minutes for full absorption. After soaking, the mixture needs to be taken out and kept stand until the ethanol is completely volatilized, so that the experiment is not influenced.
(4) Taking out the strain from the refrigerator, and activating and awakening for 30 minutes at normal temperature.
(5) Taking out the strain beside the alcohol lamp, sterilizing the bottle mouth, and shaking the liquid culture medium. And (3) taking off the tinfoil paper wrapped at the bottle mouth, transferring 10mL of bacteria liquid into a test tube by using a pipette, wrapping the liquid culture medium and placing the liquid culture medium aside, roasting the opening of the test tube for a moment by using an alcohol lamp, plugging a rubber plug, and vibrating for 10s.
(6) Opening a rubber plug of the test tube beside the alcohol lamp, sucking the bacteria liquid by using a liquid transfer gun, dripping the bacteria liquid into the prepared solid culture medium, coating, and standing for 10 minutes. And then, putting the drug sensitive paper soaked with the intelligent food fresh-keeping material into the center of a culture dish by using tweezers to ensure that only one piece of drug sensitive paper exists in one culture dish to prevent interference, then putting the culture dish into a constant-temperature constant-humidity incubator, and observing the size of a bacteriostatic zone after culturing for 24-48 hours according to experimental requirements. The fungi were cultured at 27 deg.C, the bacteria were cultured at 37 deg.C, and the control group was made of conventional food fresh-keeping material (drug sensitive paper with copper sulfate).
(7) After 48h, it was found that: the bacteriostatic circle of the traditional food fresh-keeping material is far smaller than that of the food fresh-keeping material prepared by the invention. The experimental results show that: the fresh-keeping cold catalyst material has obvious bacteriostatic effect on staphylococcus aureus, escherichia coli, aspergillus niger, bacillus subtilis and the like, as shown in figures 2 to 5.
(2) Ethylene determination experiment
The photocatalytic test for ethylene measurement needs to be performed in a closed space made of an acrylic plate material (50 cm. Times.50 cm). Because normal fresh fruits and vegetables cannot release ethylene continuously and uniformly, in consideration of the problem of ethylene gas source, a tank of pure ethylene with the concentration of 99.99 percent is purchased as a gas source for testing, and the testing condition is a dark and dark environment without illumination.
The method comprises the following specific steps: a certain amount of ethylene gas is filled in a closed space, paper (obtained by arranging the cold catalyst material coating in the embodiment 1 on the paper) coated with an intelligent food fresh-keeping material to be measured is placed in the closed space, the internal ethylene concentration in an initial state is measured by an ethylene measuring instrument under the condition of no illumination, and the subsequent internal ethylene concentration condition is measured at regular time. The experimental results show that: the adsorption and decomposition rate of the fruit and vegetable fresh-keeping cold catalyst material on ethylene harmful gas is increased from 20% to about 80% within 5 min-12 h, and most of ethylene harmful gas can be removed, as shown in figure 6; as can be seen from the catalytic performance curve of the cold catalytic material in FIG. 7, the peak value of the optical wavelength of the catalytic performance of the cold catalytic material of the present invention is mainly below 350nm, which is the normal illumination in the dark, therefore, the catalytic performance of the fresh-keeping material made of the fresh-keeping cold catalytic material in the present application can be performed in the weak light or dark.
(3) Waxberry preservation test
The cold catalyst material of example 1 was mixed with PE particles in an amount of 5% and blown into a plastic film at 180 ℃. The film product was used in a representative test for keeping red bayberry fresh, which is easily rotten, in an environment of 25 deg.C and 85 deg.C, and the results are shown in FIG. 8.
As can be seen from fig. 8: the time for producing the mold of the antibacterial bag sample using the cold-contact enzyme material is prolonged by more than 24 hours compared with the time for producing the mold of a common PE bag and is prolonged by more than 48 hours compared with the time for producing the mold without using a plastic bag.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be made by those skilled in the art without inventive work within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.
Claims (10)
1. A preparation method of a fresh-keeping cold catalyst material is characterized by comprising the following steps:
(1) Dispersing clay minerals in an organic solvent, and uniformly stirring to obtain clay mineral dispersion liquid;
(2) Adding a silver source, a potassium source, a manganese source, a zinc source, a titanium source and a dispersing agent into the clay mineral dispersion liquid, uniformly stirring, and calcining at 475-485 ℃ for 8-24 hours under 183-207 kPa to obtain a silver-doped cryptomelane type zinc-titanium composite oxide with a pore passage taking a clay mineral as a carrier;
(3) And (3) uniformly mixing the copper ion antibacterial agent and the dispersing agent to obtain a copper ion antibacterial agent dispersion liquid, adding the copper ion antibacterial agent dispersion liquid into the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with the clay mineral as the carrier prepared in the step (2), mixing and stirring for 6-24 hours in an ultrasonic device at 15-65 ℃, and drying to obtain a dispersion, namely the fresh-keeping cold catalyst material.
2. The method for preparing a fresh-keeping cold catalyst material as set forth in claim 1, wherein: in the step (1), the clay mineral is one or more of kaolin, vermiculite, silicon dioxide and diatomite, and the organic solvent is absolute ethyl alcohol and glacial acetic acid; the rotation speed during stirring in the steps (1) to (2) is 2000 to 4500r/min.
3. The method for preparing a fresh-keeping cold catalyst material as set forth in claim 1, wherein: in the step (2), the silver source is silver-loaded titanium dioxide, the potassium source is potassium permanganate or potassium chloride, the manganese source is potassium permanganate, the zinc is zinc oxide, the titanium source is titanate, rare earth aluminate titanium dioxide, titanium dioxide powder or silver-loaded titanium dioxide, and the dispersing agent is phthalimide and/or vinyl acetate resin.
4. The method for preparing a fresh-keeping cold catalyst material as set forth in claim 1, wherein: the mass parts of the clay mineral, the silver source, the potassium source, the manganese source, the zinc source and the titanium source in the step (2) are as follows: 45 to 80 percent of clay mineral, 2 to 5 percent of silver source, 2 to 5 percent of potassium source, 2 to 5 percent of manganese source, 4 to 15 percent of zinc source and 10 to 25 percent of titanium source.
5. The method for preparing a fresh-keeping cold catalyst material as set forth in claim 1, wherein: the chemical general formula of the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide in the pore channel in the step (2) is as follows: ag x (A) y [M z Ti 8-z ]O 16 Wherein M = Mn 2+ 、Zn 2+ ，A＝K + 、H + ；x≤2；y≤2；z≤3，[M z Ti 8-z ]O 16 Represents the framework composition of a cryptomelane type crystal structure zinc-titanium composite oxide with silver doped pore channels, and Ag x (A) y Showing the channel composition of the cryptomelane type crystal structure zinc-titanium composite oxide with the channel doped with silver.
6. The method for preparing a fresh-keeping cold catalyst material as set forth in claim 1, wherein: the copper ion antibacterial agent in the step (3) is selected from copper sulfate, copper acetylacetonate, nano copper oxide, copper hydroxide, cuprous oxide, copper chloride, copper acetate, copper amino acid, copper humate, copper abietate, copper succinate or copper ammine; in the step (3), the dispersant is phthalimide and/or vinyl acetate resin; the mass ratio of the copper ion antibacterial agent to the silver-doped cryptomelane type crystal structure zinc-titanium composite oxide with the pore channel taking the clay mineral as the carrier is 2-4: 20 to 55.
7. The method for preparing fresh-keeping cold catalyst material according to claim 1, wherein the method comprises the following steps: the frequency of the ultrasonic equipment in the step (3) is 15-25 kHz; the particle size of the dispersoid in the step (3) is 30-200 nm; the fresh-keeping cold catalyst material in the step (3) is a combination of zinc-titanium composite oxide with a pore canal doped with silver and having a cryptomelane type crystal structure and a copper ion antibacterial agent, wherein the clay mineral is used as a carrier.
8. A fresh-keeping cold catalyst material is characterized in that: prepared by the process of any one of claims 1 to 7.
9. The use of the fresh-keeping cold catalyst material of claim 8 in fresh-keeping packaging materials for fruits, vegetables and chilled meat products.
10. Use according to claim 9, characterized in that: the fresh-keeping cold catalyst material is applied to paper in a coating mode and is used as a fresh-keeping packaging material; or the fresh-keeping cold catalyst material is used as an effect particle to be added into a plastic product to be used as a fresh-keeping packaging material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211460159.2A CN115918714A (en) | 2022-11-17 | 2022-11-17 | Fresh-keeping cold catalyst material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211460159.2A CN115918714A (en) | 2022-11-17 | 2022-11-17 | Fresh-keeping cold catalyst material and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115918714A true CN115918714A (en) | 2023-04-07 |
Family
ID=86655048
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211460159.2A Withdrawn CN115918714A (en) | 2022-11-17 | 2022-11-17 | Fresh-keeping cold catalyst material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115918714A (en) |
-
2022
- 2022-11-17 CN CN202211460159.2A patent/CN115918714A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108283178B (en) | ZnO/Ag/graphene nano composite material, and preparation method and application thereof | |
| CN108246046B (en) | Sterilizing air purifying agent and preparation method and application thereof | |
| CN112056379B (en) | Plant essential oil slow-release fresh-keeping tablet and preparation method and application thereof | |
| WO2009049450A1 (en) | An associated sterilization method comprising ozone, ultraviolet and nano-silver coating for quality maintenance of freeze-dried food | |
| CN103084062B (en) | Device for purifying air and keeping freshness | |
| CN109516570A (en) | The complex micro organism fungicide of purifying sea water breeding wastewater | |
| CN203123826U (en) | Device for purifying air and retaining freshness | |
| CN108607483B (en) | Traditional Chinese medicinal material curing agent with oxygen slow release function and preparation method and use method thereof | |
| CN108576192A (en) | Intelligent photocatalysis antibacterial preservation device and its preservation method for fruits and vegetables storeroom | |
| CN106344948A (en) | Composite material with sterilization and odor-removal functions as well as preparation method and use method thereof | |
| CN115918714A (en) | Fresh-keeping cold catalyst material and preparation method and application thereof | |
| CN115260682B (en) | Preparation method of recyclable and renewable photocatalytic preservative film | |
| CN115532229A (en) | Preparation of magnetic adsorbent material and application of bacterium carrier construction in removing aflatoxin | |
| CN107619839A (en) | One kind reduces vomitoxin fermentation wheat bran and its production method and application | |
| CN114957748A (en) | Antibacterial food packaging film and preparation method thereof | |
| CN211091639U (en) | Fresh-keeping processing system reaches fresh-keeping freezer including it | |
| KR101850629B1 (en) | Composition comprising nanostructure layered double hydroxide with antimicrobial agent for shelf-life extension of fresh-cut produce | |
| CN1037847A (en) | Dual-sucking seal-storage agent for fresh-keeping, its preparation method and use thereof | |
| Teymourlouei et al. | Covalent immobilization of Saccharomyces cerevisiae and Candida albicans cell walls for aflatoxin M1 bio‐detoxification | |
| CN113150517B (en) | Biodegradable plastic film material and preparation method thereof | |
| Liu et al. | Nanomaterials for fresh-keeping and sterilization in food preservation | |
| JP3061287U (en) | Sheet material with antimicrobial properties | |
| JP2003286120A (en) | Method for preserving live fungus preparation of genus fusarium fungus | |
| JPH11388A (en) | Deodorand and antibacterial powder material | |
| CN114573825B (en) | Ligand-exchanged hollow MIL-101 metal organic framework material and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20230407 |