Preparation method of low-concentration broad-spectrum antibacterial nano material and chicken preservation method
By preparing and solidifying the low-concentration ZIF-67 nanomaterial in polycaprolactone, the drug resistance problem and the short shelf life of cold fresh chicken were solved, and effective inhibition of MRSA and E.coli and the extension of the shelf life of chicken were achieved.
Patent Information
- Application Number
- CN202510260062.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-06
- Publication Date
- 2025-06-06
AI Technical Summary
The prior art has drug resistance problems in preventing and treating methicillin-resistant Staphylococcus aureus (MRSA) and E. coli (E.coli), which affects the bactericidal effect. At the same time, cold fresh chicken faces problems such as microbial contamination, oxidation and water loss during storage, transportation and sales, resulting in a short shelf life.
Low-concentration broad-spectrum antibacterial ZIF-67 nanomaterial was prepared, and antibacterial plastic wrap was prepared by solidifying it into polycaprolactone (PCL), which was used to inhibit the growth of MRSA and E.coli and prolong the shelf life of cold fresh chicken.
Effective inhibition of MRSA and E.coli was achieved, reducing the risk of bacterial resistance, and at the same time prolonging the shelf life of cold fresh chicken and maintaining its quality.
Smart Images
Figure CN120098277A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of food preservation, and relates to a preparation method of a low-concentration broad-spectrum antibacterial nanomaterial without loading any natural compounds and a chicken preservation method Background Art
[0002] Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) are two common Gram-spore bacteria and are common foodborne pathogens. Many foodborne diseases are caused by the ingestion of microorganisms and plant toxins. Infection can cause pneumonia, pseudomembranous colitis, pericarditis, etc. In severe cases, it can even cause fatal infections such as septicemia and sepsis.
[0003] At present, the main methods for the prevention and control of MRSA and E. coli in agriculture are physical control, biological control and chemical control, but all of them have certain disadvantages. Although chemical antimicrobial agents have the characteristics of rapid bactericidal effect, stable effect and relatively simple control operation, with the abuse of drugs, bacteria mutate frequently and gradually develop drug resistance, which will seriously affect the bactericidal effect of chemical antimicrobial agents. Therefore, it is urgent to develop a new safe and efficient means of bacterial control, which is of great significance to ensuring the health of the people and the high-quality development of the meat industry.
[0004] Nanomaterials have the characteristics of small size, large specific surface area, low toxicity, high stability and good biocompatibility, and are easier to penetrate biofilms and interact with bacteria, so they have broad research prospects. As an excellent MOFs material, ZIF-67 is usually used to load natural compounds or small molecule drugs for synergistic antibacterial effects. Although the dosage of drugs is reduced, it will inevitably cause bacterial resistance and reduce the antibacterial effect.
[0005] Fresh chicken has won the favor of consumers for its fresh taste and rich nutritional value. However, in the storage, transportation and sales of fresh chicken, it faces many challenges: microbial contamination, oxidation, water loss, etc. How to effectively maintain the freshness and quality of fresh chicken is an urgent problem to be solved in the industry.
[0006] Therefore, the present invention prepares a safe ZIF-67 nanomaterial with a broad-spectrum antibacterial effect at a low concentration, and does not need to load any other natural compounds, which reduces drug resistance and makes the material safer. It is immobilized in polycaprolactone (PCL) to prepare an antibacterial preservative film and applied to actual antibacterial preservation to extend the shelf life of cold fresh chicken. This preparation method has low energy consumption, simple operation, low equipment requirements, low cost, and can be mass-produced, which lays a theoretical foundation for the more efficient and safe application of nanomaterials in antibacterial research, and also provides new ideas for the development and application of nanomaterials in the field of meat preservation. Summary of the invention
[0007] In view of the shortcomings of the prior art, the present invention provides a method for preparing a low-concentration broad-spectrum antibacterial nanomaterial and preserving chicken meat, so as to solve the problems of weight loss and oxidation generated during the storage and preservation of chicken, and extend the shelf life of fresh chicken.
[0008] In order to achieve the above object, the technical solution adopted by the present invention is to use a low-concentration broad-spectrum antibacterial nanomaterial to inhibit the growth of MRSA and E.coli and prepare it into an antibacterial cling film to achieve the preservation of chicken. The present invention is achieved through the following technical solutions:
[0009] The invention provides a preparation method of a low-concentration broad-spectrum antibacterial nanomaterial and a chicken preservation method, wherein the bacteria are MRSA and E.coli; the nanomaterial is a ZIF-67 nanomaterial; the low concentration is MIC=20 μg / mL and 100 μg / mL; and the cold fresh chicken preservation method comprises preparing an antibacterial preservative film to inhibit bacteria and preserve the chicken.
[0010] Accordingly, a method for preparing a low-concentration broad-spectrum antibacterial nanomaterial and preserving chicken comprises the following steps:
[0011] (1) Preparation of ZIF-67 nanomaterials: Cobalt nitrate hexahydrate (Co(NO3)·6H2O) and cetyltrimethylammonium bromide (CTAB) in appropriate proportions were dissolved in distilled water containing 2-methylimidazole. After stirring for 1 h, the resulting solution was centrifuged to collect the product and washed alternately with deionized water and anhydrous ethanol several times. Finally, the product was collected by vacuum drying at 60°C for 12 h.
[0012] (2) Preparation of antibacterial cling film: The ZIF-67 nanomaterials prepared above were immobilized in PCL to prepare antibacterial cling film.
[0013] Preferably, the Co(NO 3 )·6H 2 The mass ratio of O and CTAB is 29:3.
[0014] Preferably, the immobilization amount of the ZIF-67 nanomaterial is 10 mg / mL.
[0015] The ZIF-67 nanomaterial prepared in the present invention has a cubic structure with an average diameter of 100±20nm, and has a significant inhibitory effect on MRSA and E.coli (MIC values are 20μg / mL and 100μg / mL, respectively). In addition, by constructing a bacterial infection chicken model and immobilizing the ZIF-67 nanomaterial into PCL to make an antibacterial cling film, the shelf life of chicken can be significantly extended. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:
[0017] Figure 1 Scanning electron microscope image of ZIF-67 nanomaterial
[0018] Figure 2 Infrared spectrum of ZIF-67 nanomaterials
[0019] Figure 3 X-ray diffraction pattern of ZIF-67 nanomaterials
[0020] Figure 4 Antibacterial MIC diagram of ZIF-67 nanomaterials
[0021] Figure 5 Scanning electron microscopy images of the antibacterial effects of ZIF-67 nanomaterials on MRSA and E.coli
[0022] Figure 6 EPR image of ZIF-67 nanomaterials
[0023] Figure 7 Fourier infrared spectrum of ZIF-67 plastic wrap
[0024] Figure 8 Comparison chart of keeping chicken fresh DETAILED DESCRIPTION
[0025] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose, the specific operation mode and effect results of the present invention are described in detail below in combination with the accompanying drawings and embodiments.
[0026] Embodiment 1:
[0027] Step 1: Preparation of ZIF-67 nanomaterials
[0028] First, weigh 4.54 g of 2-methylimidazole and dissolve it in 70 mL of deionized water (solution A) and stir evenly. Then weigh 290 mg of Co(NO 3 )·6H 2 O and 30 mg CTAB were dissolved in 10 mL deionized water (solution B) and stirred evenly. Finally, solution B was quickly poured into solution A while stirring, and stirring was continued at room temperature for 1 h. The obtained purple solution was washed alternately with deionized water and anhydrous ethanol for 3 times, centrifuged and dried in a vacuum drying oven at 60 ° C for 12 hours. When used, deionized water was used to prepare the required concentration gradient by the method of multiple dilution.
[0029] Step 2: Structural characterization of ZIF-67 nanomaterials
[0030] The morphology of ZIF-67 nanomaterials was observed by scanning electron microscopy; the functional groups of ZIF-67 nanomaterials were further determined by Fourier transform infrared spectrometer; and the crystal structure of ZIF-67 nanomaterials was further determined by X-ray diffractometer.
[0031] according to Figure 1 Scanning electron microscopy images show that the ZIF-67 nanomaterial is a cubic structure with an average diameter of 100±20nm. Figure 2 Fourier transform infrared spectroscopy results show that ZIF-67 nanomaterials have a wavelength of 600-1500 cm -1 、1580cm -1 、2927cm -1 and 3132cm -1 There is a vibration peak at , which is mainly attributed to the ligand 2-methylimidazole. Figure 3 X-ray diffraction results show that each group of materials exhibits strong diffraction peaks at 7.4°, 10.4°, 12.7°, 14.4°, 16.5° and 18.1°, corresponding to the crystal planes of (001), (002), (112), (022), (013) and (222), respectively. These results further indicate that the present invention successfully prepared the ZIF-67 nanomaterial.
[0032] Example 2
[0033] Step 1: Determination of the antibacterial MIC value of ZIF-67 nanomaterials. Dissolve different concentrations of ZIF-67 in deionized water using ultrasonic technology. Add 200 μL of 1×10 6 CFU / mL of MRSA and E.coli, then add different concentrations of nanomaterials, culture overnight at 37℃, add 10μL of 10mg / mL of resazurin solution, and place it in a 4℃ refrigerator for 4h before observing its color change (the well turns red, indicating the presence of MRSA or E.coli).
[0034] according to Figure 4 The results show that when the concentration of ZIF-67 nanomaterials is ≥20μg / mL, the growth of MRSA can be inhibited; when the concentration of ZIF-67 nanomaterials is ≥100μg / mL, the growth of E.coli can be inhibited.
[0035] Step 2: Microstructure observation of ZIF-67 nanomaterials after bacterial treatment
[0036] In 3mL, the concentration is 1×10 9ZIF-67 was added to MRSA or E. coli with CFU / mL, cultured at 37°C for 4 h, and then the morphology of the bacteria was photographed using a scanning electron microscope.
[0037] Figure 5 The results showed that the bacteria in the blank group did not show any signs of rupture; the two bacterial cells treated with ZIF-67 nanomaterials showed signs of rupture, which indicated that the bacteria died after being treated with ZIF-67 nanomaterials.
[0038] Example 3
[0039] Step 1: Construction of bacterial infection chicken model
[0040] The concentration was prepared to be 1×10 6 CFU / mL of MRSA and E. coli suspensions, the chickens were coated in the two suspensions in turn, and each piece of chicken was inoculated three times.
[0041] Step 2: Preparation of antibacterial cling film
[0042] ZIF-67 nanomaterials with a concentration of 10 mg / mL were immobilized in PCL to prepare antibacterial plastic wrap.
[0043] Step 3: Treat the chicken with antibacterial plastic wrap
[0044] The chicken was randomly divided into three groups, with 3 pieces of chicken in each group. They were: blank group: the chicken was directly stored without further treatment as a blank control; PCL group: the chicken was wrapped with PCL film; ZIF-67 nanomaterial group: the chicken was wrapped with antibacterial plastic wrap. The chicken in the three groups was stored at 4°C, and the quality changes of the chicken were observed and recorded.
[0045] Depend on Figure 7 It can be seen that the ZIF-67 antibacterial film prolongs the shelf life of chicken and maintains the quality of chicken.
Claims
1. A low-concentration broad-spectrum antibacterial nanomaterial, characterized by: The bacteria are methicillin-resistant Staphylococcus aureus and Escherichia coli; the nanomaterial is a cubic ZIF-67 nanomaterial with a size of 100±20 nm.
2. A low-concentration broad-spectrum antibacterial nanomaterial according to claim 1, characterized in that: The MIC values of the nanomaterials for inhibiting methicillin-resistant Staphylococcus aureus and Escherichia coli were 20 μg / mL and 100 μg / mL, respectively.
3. The method for preparing a low-concentration broad-spectrum antibacterial nanomaterial according to claim 1, characterized in that: The following steps are involved: Appropriate proportions of Co(NO3)·6H2O and CTAB were dissolved in distilled water containing 2-methylimidazole. After stirring for 1 h, the resulting solution was centrifuged to collect the product and washed alternately with deionized water and anhydrous ethanol several times; finally, the product was collected by vacuum drying at 60°C for 12 h.
4. The method for preparing a low-concentration broad-spectrum antibacterial nanomaterial according to claim 3, characterized in that: The mass ratio of Co(NO3)·6H2O and CTAB in the preparation of ZIF-67 nanomaterials is 29:
3.
5. A method for preserving chicken, characterized in that: The chicken preservation method is to prepare an antibacterial cling film to inhibit bacteria and preserve fresh cold chicken; the antibacterial cling film is prepared by immobilizing the low-concentration broad-spectrum antibacterial nanomaterial described in claim 1 or 2 or the low-concentration broad-spectrum antibacterial nanomaterial prepared by the preparation method of claim 3 into polycaprolactone to prepare the antibacterial cling film.
6. A chicken preservation method according to claim 5, characterized in that: The solid loading amount of ZIF-67 nanomaterials in the preparation of antibacterial cling film is 10 mg / mL.