阅读说明：本技术 铜/碳纳米复合材料在食品保鲜中的应用 (Application of copper/carbon nano composite material in food preservation ) 是由 连崑 于 2021-08-18 设计创作，主要内容包括：本发明公开了铜/碳纳米复合材料在食品保鲜中的应用,所述铜/碳纳米复合材料包括具有多孔结构的碳壳以及包裹于所述碳壳中的铜纳米粒子。本发明提供的铜/碳纳米复合材料,具有抑菌和抗病毒的功效,可将食品上的细菌、真菌、病毒和其它微生物总量控制在一定范围内,降低了这些微生物对食品的影响,从而延长了食品保鲜的时间。这种铜/碳纳米复合材料可以对包括肉类、蔬菜、水果、鲜活水产品等多种类的食品进行保鲜,并且能够通过多种形式对食品进行保鲜,适用范围广,且保鲜效果优于同类产品。(The invention discloses an application of a copper/carbon nano composite material in food preservation, wherein the copper/carbon nano composite material comprises a carbon shell with a porous structure and copper nanoparticles wrapped in the carbon shell. The copper/carbon nano composite material provided by the invention has antibacterial and antiviral effects, can control the total amount of bacteria, fungi, viruses and other microorganisms on food within a certain range, and reduces the influence of the microorganisms on the food, thereby prolonging the time for keeping the food fresh. The copper/carbon nano composite material can keep freshness of various foods including meat, vegetables, fruits, fresh and live aquatic products and the like, can keep freshness of the foods in various forms, has a wide application range, and has a fresh-keeping effect superior to that of similar products.)

1. The application of the copper/carbon nano composite material in food preservation comprises a carbon shell with a porous structure and copper nanoparticles wrapped in the carbon shell.

2. The use according to claim 1, wherein the copper/carbon nanocomposite isA copper/carbon composite material.

3. Use according to claim 2, wherein the copper/carbon nanocomposite is added directly to a food product.

4. Use according to claim 3, wherein the copper/carbon nanocomposite is added in an amount of 0.1-5 wt% in the food product.

5. The use of claim 2, wherein the copper/carbon nanocomposite is formulated into a preservation soak solution, and the preservation soak solution is used to soak food to achieve preservation; in the fresh-keeping soak solution, the addition amount of the copper/carbon nano composite material is 0.1-50 wt%.

6. The application of the copper/carbon nano composite material in the fresh keeping of fresh and alive aquatic products.

7. The use according to claim 6, wherein the copper/carbon nanocomposite is added directly to the body of water of transportation of the fresh and live aquatic products.

8. The use according to claim 7, wherein the copper/carbon nanocomposite is added in an amount of 0.1-5 wt% in the body of transport water.

9. The preservation container is characterized in that 0.3-10 wt% of copper/carbon nano composite material is added in the production process of the preservation container.

10. The preservative film is characterized in that 0.3-10 wt% of copper/carbon nano composite material is added into the preservative film.

Technical Field

The invention relates to the technical field of food preservation, in particular to application of a copper/carbon nano composite material in food preservation.

Background

Microorganisms do not exist everywhere in the environment, and food is easily polluted by the microorganisms in the processes of production, processing, transportation, storage and sale, so that the food is decayed. Therefore, the pollution-free preservation of fresh meat, fresh and live aquatic products, fruits and foods is a great problem which needs to be solved urgently at present. At present, the traditional preservation method is divided into a physical preservation method and a chemical preservation method. Physical preservation methods, such as low-temperature freezing preservation, salting preservation and the like, can only be used for short-term preservation, and inevitably change the original flavor of the aquatic products. However, the commonly used chemical fresh-keeping method, such as adding chemical antistaling agent and antibiotic, is more and more rejected by consumers because of adding chemical components to different degrees. In contrast, the biological preservative is not only harmless to the health of human bodies, but also does not change the flavor of food. The effect of some biological antistaling agents even exceeds that of chemical antistaling agents. Therefore, the development of a novel, safe and efficient biological preservative is a key point of attention of food researchers. However, the biological preservative has the defects of poor preservation effect, narrow application range and the like. Compared with a liquid preservative, the coating preservative has longer retention time on the surface of food, can prolong the shelf life of food to a greater extent, and is mainly applied to the preservation and freshness preservation of fresh food such as fruits and vegetables, meat products, eggs and the like. However, the coating preservative has a weak inhibition effect on anaerobic bacteria, so that the preservation effect is limited.

Disclosure of Invention

The invention aims to solve the technical problem of providing the application of the copper/carbon nano composite material in food preservation.

In order to solve the technical problems, the invention provides the following technical scheme:

the invention provides an application of a copper/carbon nano composite material in food preservation, wherein the copper/carbon nano composite material comprises a carbon shell with a porous structure and copper nanoparticles wrapped in the carbon shell.

Further, the mass ratio of the copper element to the carbon element in the copper/carbon nano composite material is about 1: 2-20. Wherein the carbon shell is preferably porous carbon black.

In the inventionThe copper/carbon nanocomposite is preferablyCopper/carbon nanocomposites. Such asThe copper/CARBON nano composite material is disclosed in patent application documents with the application date OF 2007.2.8, the international application number OF PCT/US2007/061862, the international publication number OF WO/2007/095454, the invention name OF CARBON-ENCASED METAL NANOPROARTICLES AND SPONGES, METHODS OF SYNTHESIS, AND METHODS OF USE (CARBON-coated metal nano particles AND SPONGES AND preparation METHODS AND USE METHODS thereof), which is prepared by taking plant fibers as templates AND metal copper ions as raw materials AND adopting a heating carbonization reduction method. In the copper/carbon nano composite material, nano copper is uniformly embedded in porous carbon black, and the surface of the copper/carbon nano composite material has a balance system of copper and cuprous oxide, so that the copper/carbon nano composite material has a unique renewable function. The additive has low copper ion leaching rate and low biological toxicity, and even if the additive is metabolized and discharged out of the body, the additive causes less pollution to the environment than other copper source additives.

In addition, the first and second substrates are,the copper/carbon nanocomposite also has good safety. Experiments prove that the composite material has the advantages of high strength,the copper/carbon nano composite material meets the Chinese food safety standard, and can achieve excellent performances of bacteria control, mildew prevention, virus inhibition, organic substance adsorption, photocatalysis and the like within the dosage of human body trace elements recommended by FDA. And has no acute toxicity and no irritation to skin and vaginal mucosa tissue, and the dissolved amount of copper ions meets the national drinking water standard. The biological toxicity is low, and the pollution to the environment is less than that of other copper source additives even after the copper source additives are metabolized and discharged out of the body, thereby meeting the Chinese food safety standard.

The copper/carbon nano composite material has the effects of bacteriostasis and antivirus, can control the total amount of bacteria, fungi, viruses and other microorganisms on food within a certain range, reduces the influence of the microorganisms on the food, and prolongs the time for keeping the food fresh.

The copper/carbon nano composite material can be used for keeping food fresh in various forms, for example, the copper/carbon nano composite material is directly added into food to serve as a food preservative to keep the food fresh; meanwhile, the copper/carbon nano composite material can also be used as a supplement of copper trace elements necessary for human bodies. Preferably, the copper/carbon nanocomposite is added in an amount of 0.1 wt% to 5 wt% in the food product.

The copper/carbon nano composite material can also be prepared into a fresh-keeping soak solution, and the fresh-keeping soak solution is adopted to soak food to realize fresh keeping. Preferably, the addition amount of the copper/carbon nano composite material in the fresh-keeping soak solution is 0.1 wt% -50 wt%. Experiments prove that the method adoptsThe strawberry treated by the copper/carbon nano composite material has no mould growth after 5 days at the room temperature of 10-15 ℃, but the time for the strawberry of the control group to have the mould plaque is two days.

The copper/carbon nano composite material can also be used for keeping fresh of fresh and live aquatic products, and specifically, the copper/carbon nano composite material can be directly added into a transportation water body of the fresh and live aquatic products, so that various aquatic pathogenic bacteria and viruses (better than malachite green effect) in the water body can be removed, the content of ammonia nitrogen and phosphorus in the water body is reduced, the oxygen content is increased, and the survival rate of the fresh and live aquatic products in the long-distance transportation process can be improved. Preferably, the addition amount of the copper/carbon nanocomposite in the transportation water body is 0.1 wt% -5 wt%.

In addition, the copper/carbon nano composite material can also be added into plastics such as PC, PE and the like to prepare a preservative film, and the preservative film can also play a role in sterilizing and prolonging the preservation time when being covered on food. Preferably, in the plastic wrapThe addition amount of the copper/carbon nano composite material is 0.3 to 10 weight percent. Experimental data show that the preservative film has good preservation capability. According to the national fresh meat evaluation standard (GB-ffff), the content of the active ingredients isThe fresh meat preserved by the preservative film of the copper/carbon nano composite material is kept at the first-grade fresh meat for at least 7 days at the temperature of 4 ℃ than the fresh meat coated by the conventional preservative film. By containingThe preservative film made of the copper/carbon nano composite material coats and preserves the juicy peaches, and the preservative effect of the juicy peaches is the best effect among preservative films with similar functions in the current market.

In addition, the copper/carbon nano composite material can also be added into a plastic box and a paperboard box to prepare a fresh-keeping container, and can also play a role in keeping food fresh. Preferably, the amount of the copper/carbon nano composite material added in the manufacturing process of the fresh-keeping container is 0.3 wt% -10 wt%.

Compared with the prior art, the invention has the beneficial effects that:

1. the copper/carbon nano composite material contains about 80 percent of biological carbon and has relatively large specific surface area (1000-3000 m)²/g) that can effectively adsorb organic molecules that are decomposed and released during storage of fruits and fresh meat (these decomposition products generally accelerate the spoilage process of the product); meanwhile, a Cu-CuO system generated by the unique material structure of the copper/carbon nano composite material is a composite system of visible light photocatalysis and electrochemical catalysis, so that organic molecules generated in the putrefaction process of the objects can be timely and effectively decomposed, and the autocatalysis process in the putrefaction process is reduced and blocked. Therefore, the copper/carbon nanocomposite material of the present invention has a significant advantage in terms of freshness preservation as compared with other freshness-retaining materials.

2. The copper/carbon nano composite material provided by the invention can be used for preserving various foods such as meat, vegetables, fruits, fresh and live aquatic products and the like, can be used for preserving the foods in various forms, has a wide application range, and has a preservation effect superior to that of similar products.

3. The copper/carbon nano composite material provided by the invention is non-toxic and non-irritant to human bodies, the residue on articles is very little when the copper/carbon nano composite material is used for fresh keeping, and the copper element content of the residual material is in the range of trace elements necessary for human bodies.

Drawings

FIG. 1 is a state diagram of strawberries in example 1 at days 0, 3 and 5, wherein the upper part is a test group of strawberries and the lower part is a control group of strawberries;

fig. 2 shows the results of pH test of the chilled fresh meat of example 3 in the packing of polyethylene films of the experimental group and the control group, respectively.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

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 experimental methods used in the following examples are conventional methods unless otherwise specified, and materials, reagents and the like used therein are commercially available without otherwise specified.

In the following examples of the present invention, the copper/carbon nanocomposite used included a carbon shell having a plurality of pores and copper nanoparticles wrapped in the carbon shell, and the mass ratio of copper element to carbon element was 1: 3. Specifically, the material is prepared by taking plant fibers as templates AND metal copper ions as raw materials in a heating carbonization reduction method in the invention with the application date OF 2007.2.8, the international application number OF PCT/US2007/061862, the international publication number OF WO/2007/095454, the invention name OF CARBON-ENCASED METAL nanopowderes AND SPONGES, AND the metal OF SYNTHESIS, AND METHODS OF USEs (CARBON-coated metal NANOPARTICLES AND SPONGES AND the preparation method AND the USE method thereof), wherein the preparation method is also the method disclosed in the patent.

Example 1:application of copper/carbon nano composite material in preservation of strawberries

1. Individual fresh strawberries packed in foam grid bags were purchased from the market, from which 8 were randomly selected for the experiment without significant damage and mold spots in appearance.

2. From 8 strawberries, 4 were randomly selected as experimental groups, and the remaining 4 were used as control groups. The strawberry of the experimental group is in food grade of 5 ‰Soaking the copper/carbon nano composite material solution for 5 minutes, and soaking the strawberries in clear water for 5 minutes.

3. And (3) respectively putting the two groups of strawberries into a transparent plastic box, covering the transparent plastic box, and placing and observing the strawberries at the temperature of between 10 and 15 ℃.

Fig. 1 is a state diagram of strawberries in example 1 at days 0, 3 and 5. As can be seen from the figure, on day 0, the strawberries of the experimental group and the control group were in good condition, fresh and full, had no surface damage and no mildew spots. On day 3, the strawberries of the experimental group remained in good condition, while some of the strawberries of the control group had developed enzyme spots on their surfaces. On day 5, the freshness of the strawberries of the experimental group was still good and no mildew spots appeared, while some of the strawberries of the control group had completely mildewed. This indicates thatThe copper/carbon nano composite material has a good fresh-keeping effect on the strawberries, and can prolong the storage time of the strawberries.

Example 2:copper/carbon nano-meterPhotocatalytic performance study of composite materials

TABLE 1Photocatalytic decomposition of rhodamine B in water body by copper/carbon nano composite material

Table 1 shows the results of the natural light conditions,the copper/carbon nano composite material has the effect of decomposing rhodamine B in water body in a photocatalysis way. The results in the table show that under the natural light condition, 10ppm of rhodamine can be catalytically decomposed to 40% of the original concentration within 3 days by adding 1000ppn of nano copper-carbon composite material, and the strong photocatalytic performance is shown.

Cuprous oxide is also a photosensitive semiconductor material, has the forbidden band width of 2.2eV, can be excited by light with the wavelength of less than 580 nanometers, and has higher light utilization efficiency than titanium oxide. Photocatalysis based on cuprous oxide has been difficult to engineer because of the previous difficulty in obtaining stable cuprous oxide (which can easily continue to oxidize to cupric oxide and lose photocatalytic properties). The unique nano copper/carbon composite material can form a stable copper-cuprous oxide balance system, and the material can obtain stable cuprous oxide, so that the material has higher photocatalytic performance.

The nano copper/carbon composite material contains about 78% of carbon black, has a high specific surface area, can effectively adsorb organic molecules decomposed and released by fruits and fresh meat during storage, and decomposes the organic molecules through photocatalysis, so that the nano copper/carbon composite material has a good fresh-keeping effect.

Example 3:application of copper/carbon nano composite preservative film in preservation of chilled meat

During the storage and transportation process of the chilled meat, the meat gradually deteriorates due to contact and invasion of microorganisms, and the pH value of the meat is changed, so that visual judgment can be made on the deterioration and the decay of the meat by detecting the change of the pH value of the meat.

In this example, 0.5 wt%, 3.5 wt%, 5.0 wt% of polyethylene was addedThe copper/carbon nano composite material is prepared into a polyethylene preservative film as an experimental group (3 groups), and a common polyethylene packaging film is used as a control group. The same amount of fresh meat with consistent freshness is taken, vacuum-packed in the polyethylene film, and placed at 4 ℃. The pH values of the fresh meat in the packaging films are tested at 0d, 2d, 5d, 6d, 7d, 10d, 17d, 21d, 27d, 35d, 42d, 47d and 51d respectively, and the test standard is GB/T9695.5-2008, and the obtained results are shown in Table 2. The evaluation criteria were: grade 1 freshness of 5.8-6.2, grade 2 freshness of 6.3-6.6, and deteriorated meat more than 6.7.

TABLE 2 results of pH value test of experimental group and control group

As can be seen from the results of Table 2 and FIG. 2, the chilled fresh meat packed with the conventional polyethylene packaging film can maintain the freshness of grade 1 within 17 days, the freshness of grade 2 within 21 days, and the deterioration occurs after the freshness exceeds 21 days. And the fresh meat packaged by the polyethylene preservative film added with 0.5 wt% of Cu/C composite material keeps 1-grade freshness within 21 days and keeps 2-grade freshness within 27 days. The fresh meat packaged by the polyethylene preservative film added with 3.5 wt% of Cu/C composite material can keep 1-grade freshness within 42d and 2-grade freshness within 47 d. The fresh meat packaged by the polyethylene preservative film added with 5.0 wt% of Cu/C composite material can keep 1-grade freshness within 42d and 2-grade freshness within 47 d.

Therefore, the preservative film added with the Cu/C composite material can remarkably prolong the preservation time of the chilled fresh meat and prevent the chilled fresh meat from deteriorating. Wherein the addition amount of the Cu/C composite material is more than or equal to 3.5 wt%.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.