阅读说明：本技术 一种荔枝低温等离子体无菌气调保鲜方法 (Litchi low-temperature plasma sterile air-conditioning preservation method ) 是由 钟楚杰 于 2020-07-31 设计创作，主要内容包括：本发明公开了一种荔枝低温等离子体无菌气调保鲜方法。该方法包括如下步骤：S1、清晨采摘新鲜荔枝,去掉病虫害果、损烂果、小果,干身装入气调保鲜袋,放入冷库中预冷；S2、经预冷后,将荔枝连同气调保鲜袋取出,密闭气调保鲜袋封口后,送入等离子体处理密闭室进行低温等离子体处理；S3、将经低温等离子体处理后的荔枝连同气调保鲜袋转移至冷库中贮藏,且定期再移入至等离子体处理密闭室作低温等离子体处理。该保鲜方法在荔枝保鲜上突破了长期以来主要靠化学药物处理的现状及其它物理处理效果欠佳的局面,基于低温等离子体结合无菌气调包装的物理保鲜技术,将荔枝低温保鲜期大幅延长,实现荔枝的有效保鲜。(The invention discloses a litchi low-temperature plasma sterile air-conditioning preservation method. The method comprises the following steps: s1, picking fresh litchis in the early morning, removing pest and disease damage fruits, rotten fruits and small fruits, drying, filling in an air-conditioning fresh-keeping bag, and pre-cooling in a refrigeration house; s2, after precooling, taking out the litchi and the air-conditioning fresh-keeping bag, sealing the air-conditioning fresh-keeping bag, and then sending the bag into a plasma processing closed chamber for low-temperature plasma processing; and S3, transferring the litchi subjected to the low-temperature plasma treatment and the air-conditioned fresh-keeping bag into a refrigeration house for storage, and periodically transferring the litchi into a plasma treatment closed chamber for low-temperature plasma treatment. The fresh-keeping method breaks through the current situation that litchi is mainly treated by chemical medicines for a long time and other situations that the physical treatment effect is not good enough, and based on the physical fresh-keeping technology of combining low-temperature plasma with aseptic modified atmosphere packaging, the low-temperature fresh-keeping period of the litchi is greatly prolonged, and the effective fresh-keeping of the litchi is realized.)

1. A litchi low-temperature plasma sterile modified atmosphere preservation method is characterized by comprising the following steps:

s1, picking 8-8.5 ripe litchis in the early morning, removing pest and disease damage fruits, rotten fruits and small fruits, filling air-conditioning fresh-keeping bags into the dried litchis, tightening bag openings to form small openings, and placing the litchis into a refrigeration house for precooling for 12-24 hours;

s2, after precooling, taking out the litchi and the air-conditioned fresh-keeping bag, sealing the air-conditioned fresh-keeping bag, and then sending the bag into a plasma processing closed chamber for low-temperature plasma processing for 1-10 hours;

s3, transferring the litchi after low-temperature plasma treatment and the air-conditioned fresh-keeping bag into a refrigeration house for storage, and transferring the litchi into a plasma treatment closed chamber for low-temperature plasma treatment for 1-10 hours every 3-7 days.

2. The litchi low-temperature plasma sterile air-conditioning preservation method according to claim 1, wherein the air-conditioning preservation bag is formed by blowing a resin material serving as a matrix and adding a functional material to the resin material and mixing; the resin material accounts for 60-95% of the total mass of the mixture, and the functional material accounts for 5-40% of the total mass of the mixture;

the resin material is polyethylene; the functional material is selected from more than one of biodegradable high polymer material, nucleating transparent agent, filling agent, bacteriostatic mildew inhibitor, dripping agent, coupling agent and coloring agent, and graphene and/or graphite powder.

3. The litchi low-temperature plasma sterile modified atmosphere preservation method according to claim 2, wherein the biodegradable polymer material is selected from one or more of modified starch and modified chitin, and accounts for 0-30% of the total mass of the mixture;

and/or the nucleating transparent agent is one of p-tolualdehyde sorbitol, di (benzylidene) sorbitol, di (p-methylbenzylidene) sorbitol and di (3.4-dimethylbenzylidene) sorbitol, and the nucleating transparent agent accounts for 0-3% of the total mass of the mixture;

and/or the filler is 1-4 of calcium carbonate, talcum powder, Dagu stone, zeolite, calcite, silicon dioxide, titanium dioxide, diatomite, red mud and ceramic powder, and the filler accounts for 1-15% of the total mass of the mixture;

and/or the bacteriostatic mildew inhibitor is 1-3 of silver ions, nano silver, nano titanium dioxide, nano zinc dioxide and cinnamaldehyde, and accounts for 0.5-5% of the total mass of the mixture;

and/or the dripping agent is 1-2 of sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and polyoxyethylene (5) glycerol monostearate, and accounts for 0-3% of the total mass of the mixture;

and/or the coupling agent is 1-2 of vinylmethyldimethoxysilane, vinyltriethoxysilane, polysiloxane and methyltriethoxysilane, and accounts for 0-15% of the total mass of the mixture;

and/or the colorant is one of iron oxide red, cobalt blue and titanium dioxide, and accounts for 0-3% of the total mass of the mixture.

4. The litchi low-temperature plasma sterile modified atmosphere preservation method according to claim 2 or 3, wherein the graphene and/or graphite powder accounts for 0.1-3% of the total mass of the mixture.

5. The litchi low-temperature plasma sterile modified atmosphere preservation method according to claim 1, wherein 1-2.5 kg of litchi is packaged in each modified atmosphere preservation bag; and tightening the bag opening and reserving a small opening for tightening the bag opening to reserve a small opening with the diameter of 2-3 cm.

6. The litchi chinensis Sonn low-temperature plasma sterile air-conditioning preservation method according to claim 1, wherein the precooling temperature is 0-5 ℃, and the air flow velocity is kept at 1-2 m/s.

7. the litchi chinensis Sonn low-temperature plasma sterile air-conditioning preservation method as claimed in claim 1, wherein the temperature of the low-temperature plasma treatment is 0-5 ℃, the humidity is 40-80%, the air velocity is kept at 1-8 m/s, and the concentration of positive and negative ions is kept at 2-2.5 × 10⁸Per cm³Within the range, the litchi is placed at a distance of 5-40 cm from the plasma generating source.

8. The litchi chinensis Sonn low-temperature plasma sterile modified atmosphere preservation method according to claim 1, wherein the plasma processing closed chamber is arranged in the refrigerator, and the volume of the plasma processing closed chamber is 1/10-2/15 of the volume of the refrigerator; and a plasma generator, a fan and a material loading platform are arranged in the plasma processing closed chamber.

9. The litchi chinensis Sonn low-temperature plasma sterile modified atmosphere preservation method according to claim 1, wherein the storage temperature is-2 to 7 ℃.

Technical Field

The invention belongs to the technical field of fruit and vegetable preservation, and particularly relates to a low-temperature storage and preservation method for litchi.

Background

Litchi is a fruit which is difficult to store, the picked fruit has the characteristics of color change in one day, fragrance change in two days, taste change in three days and removal of the color, fragrance and taste in four or five days, the litchi can be deteriorated and loses the commodity value generally for about 3 days under the normal temperature condition, and the storage period is only about 30 days under the low temperature condition at present. In production, the low-temperature fresh-keeping storage of the litchis is mainly carried out by using chemical medicines for sterilization, antisepsis and browning prevention, the common medicines comprise sulfur treatment, terbutol, imazalil, subaogong, citric acid, C-cysteine and the like, and the sulfur treatment is mostly used internationally. But the sulfur treatment can lose the natural fruit color, the fruit is soft, the residual peculiar smell exists, and the problems of environmental protection and safety exist. In addition, hot water and acid treatment, Chinese herbal medicine treatment, polyester film treatment, irradiation treatment and the like are also available, but the preservation period cannot be prolonged. At present, the litchi fruits in China are over 800 ten thousand mu, the annual output is about 300 ten thousand tons, the mature and marketing period of the litchi fruits is only about 7 days (measured by a single tree), only a small part is solved through deep processing, drying and juicing, the processing period can be prolonged only by depending on preservation of the juiced litchi fruits, and the preservation is the bottleneck of the industrialization of the litchi fruits at present.

The low-temperature plasma is an ionized gas having a density of charged particles to some extent, unlike a general neutral gas. Because the plasma space is enriched with ions, electrons, excited atoms, molecules, free radicals and the like, corresponding high-activity substances are generated, are easy to participate in various electrochemical reactions, and have physical, chemical and biological effects on acting substances. In addition, the plasma also has conductivity, electrical neutrality and magnetic field operability. Researches show that plasma sterilization is a novel broad-spectrum sterilization technology, has the characteristics of low temperature, high efficiency, no residue and the like, is a cold sterilization technology, and is widely applied to industries such as industry, medical treatment and the like at present. The plasma sterilization can thoroughly sterilize heat-sensitive foods such as fresh meat, fresh fruits and vegetables and fresh cut vegetables, has no secondary pollution, and can better keep sensory quality and nutrient components and original taste and flavor by being heated and sterilized.

The low-temperature plasma is applied to the fresh-keeping method of fruits and vegetables, basically, the fruits and vegetables are placed in a closed container (including a plastic bag), or the low-temperature plasma is introduced into a vacuum container to directly contact and act on the fruits and vegetables, so that the effects of sterilizing, decomposing harmful gases such as ethylene and the like, inhibiting respiration and degrading pesticides are achieved, and the aim of keeping the fruits and vegetables fresh is fulfilled. However, the vacuum container is also provided with a vacuum pump (split charging type low-temperature plasma reduced pressure preservation technical research, preservation and processing 2002.2), so that the investment is large, the operation is complicated, and if a reduced pressure warehouse is built, the investment is huge, and the operation is more difficult and complicated. A low-temperature plasma device is arranged on each plastic bag opening and connected with a plasma generator to be introduced (a method for detoxifying and preserving fruits and vegetables by using low-temperature plasma, patent application No. 001109863), fruits and vegetables are contained in a closed container, and the low-temperature plasma is introduced into the container at the same time every day (the method and the device for preserving the fruits and the vegetables by using the low-temperature plasma, patent application No. 001005006), so that the method is complex in actual operation and low in application value.

In addition, plastics are insulators that generate a large amount of static charge during application, interfering with processing and interfering with use. Antistatic agent is used in production to eliminate the influence of static electricity, but even if the conductive film is prepared for litchi preservation, tests prove that the conductive film cannot penetrate through plasma components and is ineffective in preservation.

Disclosure of Invention

The invention aims to provide a litchi low-temperature plasma sterile modified atmosphere preservation method aiming at the defects of the existing litchi preservation technology. The preservation method combines the low-temperature plasma treatment technology and the improved sterile modified atmosphere packaging technology, realizes effective preservation of the litchi, and prolongs the preservation period by more than 20 days compared with the existing preservation mode.

The above object of the present invention is achieved by the following means.

A litchi low-temperature plasma sterile modified atmosphere preservation method comprises the following steps:

s1, picking 8-8.5 ripe litchis in the early morning, removing pest and disease damage fruits, rotten fruits and small fruits, putting the litchis into an air-conditioning fresh-keeping bag after the litchis are dried, tightening the bag opening until a small opening is reserved, and putting the litchis into a refrigeration house for precooling;

s2, after precooling, taking out the litchi and the air-conditioning fresh-keeping bag, sealing the air-conditioning fresh-keeping bag, and then sending the bag into a plasma processing closed chamber for low-temperature plasma processing;

and S3, transferring the litchi subjected to the low-temperature plasma treatment and the air-conditioned fresh-keeping bag into a refrigeration house for storage, and transferring the litchi into a plasma treatment closed chamber for low-temperature plasma treatment every 3-7 days.

In a preferred embodiment, the air-conditioned fresh-keeping bag is prepared by blowing a resin material serving as a matrix and adding a functional material into the resin material to mix; the resin material is polyethylene; the functional material is selected from more than one of biodegradable high polymer material, nucleating transparent agent, filling agent, bacteriostatic mildew inhibitor, dripping agent, coupling agent and coloring agent, and graphene and/or graphite powder.

In a more preferred embodiment, the resin material accounts for 60-95% of the total mass of the mixture, and the functional material accounts for 5-40% of the total mass of the mixture.

In a more preferable embodiment, the biodegradable polymer material is selected from more than one of modified starch and modified chitin, and accounts for 0-30% of the total mass of the mixture.

In a more preferred embodiment, the nucleating transparent agent is one of p-tolualdehyde sorbitol, di (benzylidene) sorbitol, di (p-methylbenzylidene) sorbitol and di (3.4-dimethylbenzylidene) sorbitol, and the nucleating transparent agent accounts for 0-3% of the total mass of the mixture.

In a more preferable embodiment, the filler is 1-4 of calcium carbonate, talcum powder, large glutelin, zeolite, calcite, silicon dioxide, titanium dioxide, diatomite, red mud and ceramic powder, and the filler accounts for 1-15% of the total mass of the mixture.

In a more preferable embodiment, the bacteriostatic mildew inhibitor is 1-3 of silver ions, nano silver, nano titanium dioxide, nano zinc dioxide and cinnamaldehyde, and the bacteriostatic mildew inhibitor accounts for 0.5-5% of the total mass of the mixture.

In a more preferable embodiment, the dripping agent is 1-2 of sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and polyoxyethylene (5) glycerol monostearate, and the dripping agent accounts for 0-3% of the total mass of the mixture.

In a more preferable embodiment, the coupling agent is 1-2 of vinylmethyldimethoxysilane, vinyltriethoxysilane, polysiloxane and methyltriethoxysilane, and accounts for 0-15% of the total mass of the mixture.

In a more preferred embodiment, the colorant is one of red iron oxide, cobalt blue and titanium dioxide, and the colorant accounts for 0-3% of the total mass of the mixture.

In a more preferred embodiment, the graphene and/or graphite powder accounts for 0.1-3% of the total mass of the mixture.

In a preferred embodiment, 1-2.5 kg of litchis are packaged in each modified atmosphere freshness protection bag.

In a preferred embodiment, the bag opening is tightened and a small opening is reserved from the bag opening to the residual 2-3 cm in diameter.

In a preferred embodiment, the pre-cooling temperature is 0-5 ℃, and the air flow speed is kept at 1-2 m/s.

In a preferred embodiment, the pre-cooling time is 12-24 hours.

In a preferred embodiment, the time of the low-temperature plasma treatment is 1-10 hours, wherein the specific treatment time can be further determined according to varieties. In addition, the number of days between the low-temperature plasma treatments performed periodically during the storage in the refrigerator may be further determined for each specific type.

in a preferred embodiment, the temperature of the low-temperature plasma treatment is 0-5 ℃, the humidity is 40-80%, the air flow speed is kept at 1-8 m/s, and the concentration of positive and negative ions is kept at 2-2.5 × 10⁸Per cm³Within the range, the litchi is placed at a distance of 5-40 cm from the plasma generating source.

specifically, the ion concentration is kept at 2-2.5 × 10 from 5-40 cm of the plasma generator⁸Per cm³Within the range.

In a preferred embodiment, the plasma processing closed chamber is arranged in the refrigerator, and the volume of the plasma processing closed chamber is 1/10-2/15 of the volume of the refrigerator.

In a preferred embodiment, a plasma generator, a fan and a material loading platform are arranged in the plasma processing closed chamber; the plasma generator is used for generating plasma; the fan is used for blowing air to maintain the flow rate of the plasma air flow; the material carrying platform is a movable material carrying platform and can move in and out of the plasma processing closed chamber, and the air-conditioned fresh-keeping bag filled with litchis is placed on the material carrying platform.

In a preferred embodiment, the storage temperature is-2 to 7 ℃.

The litchi low-temperature plasma sterile modified atmosphere preservation method is suitable for preservation of other fruits and vegetables.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the litchi low-temperature plasma aseptic modified atmosphere preservation method of the invention is characterized in that litchi is stored in a special modified atmosphere preservation bag, precooled and then subjected to low-temperature plasma treatment, and then the litchi is stored in a refrigeration house, and periodically subjected to low-temperature plasma treatment during the low-temperature plasma treatment, thereby realizing litchi preservation. The fresh-keeping method breaks through the current situation that litchi is mainly treated by chemical medicines for a long time and other situations that the physical treatment effect is not good enough, the low-temperature fresh-keeping period of the litchi is greatly prolonged to more than 50 days from about 30 days on the basis of the low-temperature plasma combined with the improved sterile modified atmosphere packaging physical fresh-keeping technology, and the shelf life of the litchi after being unsealed is 2-3 days, so that the effective fresh keeping of the litchi is realized.

In addition, the litchi preservation method is low in cost and convenient to operate, and avoids the complex operations of low-pressure vacuum environment and direct contact fruit and vegetable treatment by directly introducing plasma into a single packaging plastic bag. Moreover, the preservation method of the invention is also suitable for the preservation of other fruits and vegetables.

Drawings

FIG. 1 is a flow chart of the operation of the litchi low-temperature plasma aseptic modified atmosphere preservation method of the present invention in the specific embodiment.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the following specific examples, but the scope and implementation of the present invention are not limited thereto. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Also, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The litchi low-temperature plasma sterile modified atmosphere preservation method disclosed by the invention is shown in figure 1 and comprises the following steps of:

s1, picking fresh litchis of 8-8.5 ripeness in the morning, removing pest and disease damage fruits, rotten fruits and small fruits, drying, filling air-conditioning fresh-keeping bags, tightening bag openings to form small openings, and placing the small openings in a refrigeration house for precooling;

s2, after precooling, taking out the litchi and the air-conditioning fresh-keeping bag, sealing the air-conditioning fresh-keeping bag, and then sending the bag into a plasma processing closed chamber for low-temperature plasma processing;

s3, transferring the litchi subjected to low-temperature plasma treatment and the air-conditioned fresh-keeping bag into a refrigeration house for storage, and transferring the litchi into a plasma treatment closed chamber for low-temperature plasma treatment every 3-7 days;

in the preservation method, the adopted air-conditioning preservation bag is formed by blowing the resin material serving as a matrix and adding the functional material to the resin material and mixing. Wherein the resin material accounts for 60-95% of the total mass of the mixture, and the functional material accounts for 5-40% of the total mass of the mixture.

Specifically, in an alternative embodiment, the resin material is polyethylene; the functional material is selected from more than one of biodegradable high polymer material, nucleating transparent agent, filling agent, bacteriostatic mildew-proof agent, dripping agent, coupling agent and coloring agent, and graphene and/or graphite powder.

In a preferred embodiment, the biodegradable polymer material is selected from more than one of modified starch and modified chitin, and accounts for 0-30% of the total mass of the mixture;

and/or the nucleating transparent agent is one of p-tolualdehyde sorbitol, di (benzylidene) sorbitol, di (p-methylbenzylidene) sorbitol and di (3.4-dimethylbenzylidene) sorbitol, and the nucleating transparent agent accounts for 0-3% of the total mass of the mixture;

and/or the filler is 1-4 of calcium carbonate, talcum powder, Dagu stone, zeolite, calcite, silicon dioxide, titanium dioxide, diatomite, red mud and ceramic powder, and the filler accounts for 1-15% of the total mass of the mixture;

and/or the bacteriostatic mildew inhibitor is 1-3 of silver ions, nano silver, nano titanium dioxide, nano zinc dioxide and cinnamaldehyde, and accounts for 0.5-5% of the total mass of the mixture;

and/or the dripping agent is 1-2 of sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and polyoxyethylene (5) glycerol monostearate, and accounts for 0-3% of the total mass of the mixture;

and/or the coupling agent is 1-2 of vinylmethyldimethoxysilane, vinyltriethoxysilane, polysiloxane and methyltriethoxysilane, and accounts for 0-15% of the total mass of the mixture;

and/or the colorant is one of iron oxide red, cobalt blue and titanium dioxide, and accounts for 0-3% of the total mass of the mixture.

In another preferred embodiment, the graphene and/or graphite powder accounts for 0.1-3% of the total mass of the mixture.

The air-conditioning fresh-keeping bag made of the material has the functions of permeating oxygen, carbon dioxide and ozone, and can realize air-conditioning fresh keeping. Moreover, after the graphene and/or graphite powder is added, the air-conditioning fresh-keeping bag has a corresponding plasma conduction effect, and the self-regulation control of the quantity of the conducted and permeated plasma can be realized based on the addition quantity of the graphene and/or graphite powder. When the air-conditioning fresh-keeping bag is in a low-temperature environment with plasma components emitted by the plasma generator, the plasma enters the air-conditioning fresh-keeping bag through the controlled conduction and penetration of the air-conditioning fresh-keeping bag, so that the effects of sterilizing, decomposing harmful gases, inhibiting respiration and the like are achieved, particularly, the air-conditioning fresh-keeping bag has an obvious inhibiting effect on the respiration of fruits and vegetables during fresh keeping, and the fresh-keeping effect is achieved.

In a preferred embodiment, when the air-conditioned fresh-keeping bag is used for bagging litchi, 1-2.5 kg of litchi in each bag can fully exert the fresh-keeping effect of the air-conditioned fresh-keeping bag and effectively keep all the bagged litchi fresh.

In a preferred embodiment, the bag opening is tightened and a small opening is reserved from the bag opening to the residual small opening with the diameter of 2-3 cm, so that air exchange is performed during precooling, and field heat is removed. After the precooling is finished, the gas environment in the bag is stable, and then sealing is carried out for controlled atmosphere preservation.

In a preferred embodiment, the pre-cooling temperature is 0-5 ℃; and a fan is arranged in the refrigeration house, and the air flow speed in the refrigeration house is kept to be 1-2 m/s by blowing air. In addition, the precooling time is 12-24 hours.

In a preferred embodiment, the time of the low-temperature plasma treatment is 1-10 hours, wherein the specific treatment time can be further determined according to varieties. In addition, the number of days between the low-temperature plasma treatments performed periodically during the storage in the refrigerator may be further determined for each specific type.

in the fresh-keeping method, the temperature of the low-temperature plasma treatment is preferably 0-5 ℃, the humidity is 40-80%, the air flow speed is kept at 1-8 m/s, and the concentration of positive and negative ions is kept at 2-2.5 × 10⁸Per cm³Range ofAnd (4) the following steps.

wherein the positive and negative ion concentration is maintained at 2-2.5 × 10⁸Per cm³the range of the ion wind is that the concentration of positive and negative ions of the ion wind blown to the air-conditioning fresh-keeping bag filled with the litchis is kept between 2 and 2.5 × 10⁸Per cm³Within the range.

In addition, specifically, the litchi is placed at a distance of 5-40 cm from the plasma generating source.

In a particularly preferred embodiment, the plasma processing closed chamber is a small-sized cold storage arranged in the cold storage, and the volume of the plasma processing closed chamber is 1/10-2/15 of the volume of the cold storage. The plasma processing closed chamber is arranged in the refrigerator, so that the low-temperature plasma processing and the cold storage mutual transfer process are carried out in the same refrigerator chamber during the preservation, the operation is convenient, the time and the labor are saved, the mutual transfer process is kept under the low-temperature environment, the litchi is prevented from being exposed under the normal-temperature or high-temperature environment in the transfer process, and the effective preservation of the litchi is more favorably realized.

In an alternative embodiment, a plasma generator, a fan and a material loading platform are arranged in the plasma processing closed chamber. Wherein the plasma generator is used as a plasma generating source and used for generating plasma. And the fan is used for blowing air to make the plasma generated by the plasma generator flow so as to maintain the flow rate of the plasma airflow. The material loading platform is a movable material loading platform and can move in and out of the plasma processing closed chamber; when low-temperature plasma treatment is carried out, the air-conditioning fresh-keeping bag filled with the litchis is placed on the material carrying table and pushed to a position 5-40 cm away from a plasma generating source in a plasma treatment closed chamber; and after the low-temperature plasma treatment is finished, the material carrying platform is directly pushed out, so that the air-conditioned fresh-keeping bags filled with the litchis are simultaneously sent out to the outside of the plasma treatment closed chamber.

In another preferred embodiment, the storage temperature is-2 to 7 ℃.

The technical solution of the present invention is described in detail below with reference to specific examples.

In the following specific examples, the air-conditioned freshness protection package used was prepared by blowing a mixture of polyethylene as a matrix, modified chitin, zeolite, diatomaceous earth, vinylmethyldimethoxysilane, nano zinc dioxide, silver ions, and graphene. Wherein, the total mass percentage of the mixture is that the polyethylene accounts for 89.13%, the modified chitin accounts for 1.0%, the zeolite accounts for 5.0%, the diatomite accounts for 2.0%, the vinylmethyldimethoxysilane accounts for 0.5%, the nano zinc oxide accounts for 1.2%, the silver ions account for 1.0%, and the graphene accounts for 0.17%.