Chitosan-zein composite nanoparticles based on low-temperature plasma modification as well as preparation method and application of chitosan-zein composite nanoparticles

Abstract

The invention discloses chitosan-zein composite nanoparticles based on low-temperature plasma modification, and a preparation method and application thereof, and belongs to the technical field of food processing. The preparation method comprises the following steps: dissolving CS in acetic acid to obtain a CS solution; the preparation method comprises the following steps: dispersing Zein in an ethanol water solution, evaporating to remove ethanol, adding water to obtain a Zein solution, and homogenizing the CS solution and the Zein solution respectively; the Zein solution and the CS solution are subjected to modification treatment through DBD-CP equipment, and a modified Zein solution and a modified CS solution are obtained respectively; and adding the modified CS solution into the modified Zein solution, uniformly mixing, and carrying out vacuum freeze drying to obtain the CSCP-ZeinCP composite nanoparticles. The DBD-CP treatment is adopted to induce CS and Zein to form hydrogen bonds and hydrophobic interaction, so that the particle size of the composite particles is reduced, the interface adsorption capacity is improved, the interface bonding force is enhanced, and the surface wettability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to chitosan-zein composite nanoparticles modified based on low-temperature plasma, a preparation method and application thereof. Background Art

[0002] In the food, pharmaceutical and cosmetic industries, Pickering emulsions are widely used in active ingredient encapsulation, functional food development and drug delivery systems because of their ability to stabilize the oil-water interface without the need for traditional emulsifiers.

[0003] In the prior art, the preparation methods of Pickering emulsion stabilizers include: 1) using chemical cross-linking to prepare stabilizers (such as patent CN202010131922.1, a method for preparing a high internal phase Pickering emulsion stabilized by egg white protein), but this method relies on organic solvents, and the residual toxicity affects safety. 2) Ultrasonic-assisted method (such as patent CN202211038717.6 uses ultrasound to assist in the preparation of lotus root starch for emulsion stabilization and functional food applications), but its process is complicated, requires multi-step processing, has high energy consumption and is difficult to scale. 3) Pickering emulsion stabilizers are prepared by high temperature or chemical treatment, but high temperature or chemical treatment causes protein denaturation and polysaccharide degradation, destroys the activity of functional ingredients, and thus limits its application in sensitive ingredients such as essential oils, probiotics, and enzyme preparations.

[0004] To this end, chitosan-zein composite nanoparticles modified by low-temperature plasma, a preparation method and an application thereof are proposed. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide chitosan-zein composite nanoparticles modified by low-temperature plasma, a preparation method and application, thereby solving the problems in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The preparation method of chitosan-zein composite nanoparticles based on low-temperature plasma modification comprises the following steps:

[0008] CS is dissolved in acetic acid to obtain a CS solution; Zein is dispersed in an ethanol aqueous solution, and then the ethanol is evaporated and removed, and water is added to obtain a Zein solution, and the CS solution and the Zein solution are homogenized respectively;

[0009] The Zein solution and the CS solution are modified by using DBD-CP equipment to obtain modified Zein solution and modified CS solution respectively;

[0010] The modified CS solution was added to the modified Zein solution, mixed evenly and then freeze-dried in vacuum to obtain CS CP -Zein CP Composite nanoparticles.

[0011] Furthermore, the pH values ​​of the CS solution and the Zein solution are both 4.

[0012] Furthermore, when preparing the Zein solution, after removing the ethanol by evaporation, the volume of water added is equal to the volume of the removed ethanol.

[0013] Furthermore, the concentrations of the CS solution and the Zein solution were both 1% w / v.

[0014] Furthermore, the concentration of the acetic acid is 1% v / v; the concentration of the ethanol aqueous solution is 80% v / v.

[0015] Furthermore, the modification treatment time of the DBD-CP device was 60 s, the treatment voltage was set to 90 kV, the frequency was 145 Hz, the electrode gap was 30 mm, the treatment medium was air, and the treatment temperature was 25 °C.

[0016] Furthermore, when preparing the composite nanoparticles, the volume ratio of the modified CS solution to the modified Zein solution is 1:8.

[0017] The chitosan-zein composite nanoparticles modified by low-temperature plasma are prepared by using the above-mentioned preparation method of the chitosan-zein composite nanoparticles modified by low-temperature plasma.

[0018] The application of the chitosan-zein composite nanoparticles modified by low-temperature plasma in the preparation of Pickering emulsion.

[0019] A Pickering emulsion, the raw materials of which include the above-mentioned chitosan-zein composite nanoparticles modified by low-temperature plasma.

[0020] Beneficial effects of the present invention:

[0021] 1. The present invention adopts DBD-CP physical modification, completely abandons chemical cross-linking agents and organic solvents, and the process is green and safe; at the same time, DBD-CP treatment completes the modification in one step, shortens the process time, and reduces energy consumption; and compared with traditional high temperature / chemical treatment that causes protein denaturation, the present invention adopts DBD-CP low-temperature modification (25°C) to retain protein activity.

[0022] 2. The present invention uses DBD-CP treatment to induce CS and Zein to form hydrogen bonds and hydrophobic interactions, the particle size of the composite particles is reduced, the interface adsorption capacity is improved, the interface bonding force is enhanced; and the surface wettability is improved (the contact angle is reduced from 117.53° to 88.20°).

[0023] 3. The encapsulation rate of the active ingredients (such as lemon essential oil) of the present invention is significantly improved, and the release rate is reduced, thereby extending the functionality of the product.

[0024] 4. The present invention enhances the interfacial binding force between polysaccharides and proteins through physical modification of DBD-CP. The stability of the Pickering emulsion stabilized by protein-polysaccharide composite nanoparticles prepared by this technology is significantly higher than that of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 The composite nanoparticles (CS CP -Zein CP ) is a flow chart of a preparation method;

[0027] Figure 2 It is a partial characterization analysis result diagram of composite nanoparticles;

[0028] Figure 3 This is another part of the characterization analysis results of the composite nanoparticles;

[0029] Figure 4 is the SEM image of the composite nanoparticles;

[0030] Figure 5 are the optical microscope images of LEO-PEs and the particle size distribution histograms at the 0th and 7th day of storage;

[0031] Figure 6 This is the result of the determination of the stability, Zeta potential and retention rate of LEO of LEO-PEs emulsion;

[0032] Figure 7 This is the dispersion and dilution stability analysis diagram of LEO-PEs emulsion. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, chitosan-zein composite nanoparticles (CS CP -Zein CP ), comprising the following steps:

[0036] S1, CS (chitosan nanoparticles) were dissolved in acetic acid (1%, v / v), and the pH value of the solution was adjusted to 4.0 using 1 mol / L NaOH or 1 mol / L HCl to prepare a CS solution with a concentration of 1% (w / v). Zein (zein granules) was dispersed in an ethanol aqueous solution (80%, v / v), and then the ethanol was removed using a rotary evaporator, and then an equal volume of water was added to the remaining Zein solution, and the pH value of the Zein solution was adjusted to 4.0 to prepare a Zein solution with a concentration of 1% (w / v). The CS solution and the Zein solution were then homogenized using a high-speed homogenizer.

[0037] S2, Zein solution and CS solution were placed separately in glass dishes and processed in DBD-CP equipment for 60 seconds; the processing voltage was set to 90 kV, the frequency was 145 Hz, the electrode gap was 30 mm, and the processing medium was air; all treatments were carried out in an environment of 25°C, and modified Zein solution and modified CS solution were obtained respectively.

[0038] S3, 5 ml of the modified CS solution (1%, w / v) was slowly added to 40 mL of the modified Zein solution (1.0%, w / v), and the mixture was uniformly mixed to obtain a composite solution, and the composite solution was vacuum freeze-dried for 48 h to obtain CS CP -Zein CP Composite nanoparticles.

[0039] Comparative Example 1

[0040] The preparation method of chitosan-zein composite nanoparticles (CS-Zein) comprises the following steps:

[0041] S1, CS (chitosan nanoparticles) were dissolved in acetic acid (1%, v / v), and the pH value of the solution was adjusted to 4.0 using 1 mol / L NaOH or 1 mol / L HCl to prepare a CS solution with a concentration of 1% (w / v). Zein (zein granules) was dispersed in an ethanol aqueous solution (80%, v / v), and then the ethanol was removed using a rotary evaporator, and then an equal volume of water was added to the remaining Zein solution, and the pH value of the Zein solution was adjusted to 4.0 to prepare a Zein solution with a concentration of 1% (w / v). The CS solution and the Zein solution were then homogenized using a high-speed homogenizer.

[0042] S2, 5 ml of CS solution (1%, w / v) was slowly added to 40 mL of Zein solution (1.0%, w / v), and the mixture was evenly mixed to obtain a composite solution. The composite solution was vacuum freeze-dried for 48 h to obtain CS-Zein composite nanoparticles.

[0043] Comparative Example 2

[0044] Chitosan-zein composite nanoparticles (CS CP -Zein) preparation method, comprising the following steps:

[0045] S1, CS (chitosan nanoparticles) were dissolved in acetic acid (1%, v / v), and the pH value of the solution was adjusted to 4.0 using 1 mol / L NaOH or 1 mol / L HCl to prepare a CS solution with a concentration of 1% (w / v). Zein (zein granules) was dispersed in an ethanol aqueous solution (80%, v / v), and then the ethanol was removed using a rotary evaporator, and then an equal volume of water was added to the remaining Zein solution, and the pH value of the Zein solution was adjusted to 4.0 to prepare a Zein solution with a concentration of 1% (w / v). The CS solution and the Zein solution were then homogenized using a high-speed homogenizer.

[0046] S2, put the CS solution into a glass dish and process it in the DBD-CP equipment for 60 seconds; the processing voltage is set to 90 kV, the frequency is 145 Hz, the electrode gap is 30 mm, and the processing medium is air; all treatments are carried out in an environment of 25°C to obtain a modified CS solution.

[0047] S3, 5 ml of the modified CS solution (1%, w / v) was slowly added to 40 mL of Zein solution (1.0%, w / v), and the mixture was uniformly mixed to obtain a composite solution, and the composite solution was vacuum freeze-dried for 48 h to obtain CS CP -Zein composite nanoparticles.

[0048] Comparative Example 3

[0049] Chitosan-zein composite nanoparticles (CS-Zein CP ), comprising the following steps:

[0050] S1, CS (chitosan nanoparticles) were dissolved in acetic acid (1%, v / v), and the pH value of the solution was adjusted to 4.0 using 1 mol / L NaOH or 1 mol / L HCl to prepare a CS solution with a concentration of 1% (w / v). Zein (zein granules) was dispersed in an ethanol aqueous solution (80%, v / v), and then the ethanol was removed using a rotary evaporator, and then an equal volume of water was added to the remaining Zein solution, and the pH value of the Zein solution was adjusted to 4.0 to prepare a Zein solution with a concentration of 1% (w / v). The CS solution and the Zein solution were then homogenized using a high-speed homogenizer.

[0051] S2, put the Zein solution into a glass dish and process it in the DBD-CP equipment for 60 seconds; the processing voltage is set to 90kV, the frequency is 145Hz, the electrode gap is 30mm, and the processing medium is air; all treatments are carried out in an environment of 25°C to obtain a modified Zein solution.

[0052] S3, 5 ml of CS solution (1%, w / v) was slowly added to 40 mL of modified Zein solution (1.0%, w / v), and the mixture was evenly mixed to obtain a composite solution. The composite solution was vacuum freeze-dried for 48 h to obtain CS-Zein CP Composite nanoparticles.

[0053] Comparative Example 4

[0054] Chitosan-zein composite nanoparticles (CS-Zein) CP The preparation method comprises the following steps:

[0055] S1, CS (chitosan nanoparticles) were dissolved in acetic acid (1%, v / v), and the pH value of the solution was adjusted to 4.0 using 1 mol / L NaOH or 1 mol / L HCl to prepare a CS solution with a concentration of 1% (w / v). Zein (zein granules) was dispersed in an ethanol aqueous solution (80%, v / v), and then the ethanol was removed using a rotary evaporator, and then an equal volume of water was added to the remaining Zein solution, and the pH value of the Zein solution was adjusted to 4.0 to prepare a Zein solution with a concentration of 1% (w / v). The CS solution and the Zein solution were then homogenized using a high-speed homogenizer.

[0056] S2, slowly add 5 ml of CS solution (1%, w / v) into 40 mL of Zein solution (1.0%, w / v), mix well and obtain a composite solution.

[0057] S3, the composite solution is put into a glass dish, and processed in a DBD-CP device for 60 seconds; the processing voltage is set to 90 kV, the frequency is 145 Hz, the electrode gap is 30 mm, and the processing medium is air; all treatments are carried out in an environment of 25° C. to obtain a modified composite solution; the modified composite solution is vacuum freeze-dried for 48 hours to obtain (CS-Zein) CP Composite nanoparticles.

[0058] Experimental testing

[0059] The composite nanoparticles prepared in Example 1 and Comparative Examples 1-4 are tested and verified below;

[0060] 1. Characterization and analysis of composite nanoparticles

[0061] 1.1. Particle size and potential analysis: The particle size and potential were measured using a Malvern nanoparticle size and Zeta potential analyzer at 25°C. All measurements were performed in at least three parallel experiments.

[0062] 1.2. TGA (thermogravimetric analysis): The thermogravimetric curve of the composite nanoparticles was analyzed using a thermogravimetric analyzer. The freeze-dried sample was placed in an aluminum crucible, maintaining a controlled mass of 5-6 mg, with a temperature range of 40-800°C and a heating rate of 20°C / min.

[0063] 1.3. Surface wettability: The surface wettability of the composite nanoparticles was determined using an optical contact angle measuring instrument. First, the composite nanoparticles were pressed into a uniform sheet using a hydraulic press, and then the sheet was placed on a glass dish, and a drop of ultrapure water (about 2 μL) was added to the surface of the sheet to achieve equilibrium before capturing the droplet image.

[0064] 1.4. FT-IR (Fourier transform infrared spectroscopy): After the composite nanoparticles were mixed with potassium bromide in a ratio of 1:11, they were ground into a fine and uniform powder using a mortar and pestle. Then, an infrared spectrometer was used to analyze the mixture at 4000-400 cm -1 The sample was scanned 32 times within the spectral range and potassium bromide pellets were used as blank control.

[0065] 1.5. XRD (X-ray diffraction): Use a combined multifunctional X-ray diffractometer at 5°min -1 The crystal structure of the composite nanoparticles was analyzed at a scanning rate of , and the XRD patterns in the range of 5°-35° were recorded.

[0066] 1.6. IFS (intrinsic fluorescence spectroscopy): Analyze using a spectrophotometer. The excitation wavelength is set to 280nm, the slit width is 5nm, and the emission wavelength range is 290nm-500nm. The measurement is performed at room temperature.

[0067] 1.7, 1 H-NMR (proton nuclear magnetic resonance): dissolve the composite nanoparticles in CD 3 In OD, a 600 MHz Avance-III nuclear magnetic resonance spectrometer was used to collect sample spectra.

[0068] The characterization results of the composite nanoparticles are shown in Figure 2 and Figure 3 As shown, Figure 2 (a)-(d) represent the particle size, Zeta potential, thermogravimetric analysis, and TGA mass loss rate of the composite nanoparticles, respectively; Figure 3 (a)-(e) represent the surface wettability, Fourier transform infrared spectroscopy, X-ray diffraction, intrinsic fluorescence spectroscopy, and proton nuclear magnetic resonance of the composite nanoparticles, respectively.

[0069] As can be seen from the figure, compared with the composite nanoparticles in other comparative examples, CS CP -Zein CP Composite nanoparticles show the following advantages;

[0070] ①Smallest particle size: CS CP -Zein CP The particle size was only 159.52±0.96nm, which was lower than that of other groups (such as CS-Zein CP The diameter of the nanostructured carbon foam (590.09nm) is significantly reduced, forming a denser interfacial adsorption layer and improving the stability of the emulsion.

[0071] ② Highest Zeta potential: The absolute value of Zeta potential reaches the highest value, the surface charge density is enhanced, the electrostatic repulsion is strong, and particle aggregation is effectively inhibited.

[0072] ③Thermal stability is significantly improved: the thermal decomposition temperature rises to 293.66℃ (CS-Zein is 292.57℃), and it can withstand high-temperature sterilization process. TGA verifies that its intermolecular cross-linking effect is enhanced.

[0073] ④ Improved surface wettability: The contact angle dropped to 88.20°, and the hydrophilicity was significantly improved, which promoted the uniform spreading of the oil-water interface and formed a stable adsorption layer.

[0074] ⑤ Enhanced interfacial bonding strength: FT-IR showed a red shift of the amide I band (from 1633 to 1631.99 cm-1), XRD revealed an increase in crystallinity (enhancement of the 11° and 18° peaks), and synergistic strengthening of hydrogen bonding and hydrophobic interactions.

[0075] ⑥ Structural integrity is preserved: IFS fluorescence red shift (λmax is 378.9nm) indicates protein structure stretching, 1 H-NMR confirmed the enhanced hydrogen bonding.

[0076] The scanning electron microscope (SEM) images of the composite nanoparticles are shown in Figure 2. Figure 4 As shown; Figure 4 A in 1 –A 3 : Corresponding to CS-Zein composite nanoparticles, Figure 4 B 1 –B 3 Corresponding to CS CP -Zein composite nanoparticles; Figure 4 C 1 –C 3 Corresponding to CS-Zein CP Composite nanoparticles; Figure 4 D 1 –D 3 Corresponding to CS CP -Zein CP Composite nanoparticles; Figure 4 E 1 –E 3 Correspondence (CS-Zein) CP Composite nanoparticles.

[0077] Figure 4 The morphology and binding state of the composite nanoparticles are shown in Figure 2. It can be seen that: CS CP -Zein CP The particles of the group have the smallest particle size, smooth surface and tight bonding, forming a dense, flat and ordered adsorption layer, which has the potential to significantly reduce the oil-water interfacial tension. This result also intuitively shows that: CS CP -Zein CP The formation of a dense interfacial structure through step-by-step modification is a key mechanism for improving the stability of Pickering emulsions.

[0078] 2. In this experiment, LEO-PEs (Pickering) emulsion samples were prepared using composite nanoparticles, and the properties of LEO-PEs were analyzed;

[0079] The preparation process of LEO-PEs (Pickering) emulsion is as follows: the composite nanoparticle solution and LEO are mixed in a ratio of 25:5 (v / v), and then homogenized at a speed of 15000 rpm for 3 min using a high-speed homogenizer to obtain a LEO-PEs emulsion sample.

[0080] 2.1 Scanning electron microscopy observation

[0081] 20 μL of the prepared emulsion sample was dripped onto a 5 mm × 5 mm polished silicon wafer, air-dried, and then fixed on a sample stage. Subsequently, it was observed using a scanning electron microscope at an accelerating voltage of 10.0 kV.

[0082] 2.2 Dispersion and dilution stability

[0083] After taking 3 mL of the prepared LEO-PEs emulsion sample and adding it into 40 mL of deionized water, the dispersibility and dilution stability of the emulsion were evaluated after standing at room temperature for 1 h.

[0084] 2.3. Emulsion centrifugal stability (ES)

[0085] After obtaining 15 mL of LEO-PEs emulsion, the emulsion was centrifuged at 1000 rpm for 5 min. After centrifugation, the emulsion was separated into two layers: an upper emulsion layer and a lower transparent liquid layer. The heights of the two layers were measured, and then the emulsion stability was calculated by the following equation:

[0086]

[0087] Where ES is the centrifugal stability of the emulsion, H S represents the height of the upper emulsion layer (cm), while H T Indicates the total height (cm).

[0088] 2.4 Zeta potential analysis

[0089] The zeta potential of the diluted LEO-PEs emulsions was measured using a Malvern Nano Particle Size and Zeta Potential Analyzer. All measurements were performed at 25 °C using at least three freshly prepared samples.

[0090] 2.5 Determination of LEO retention rate in LEO-PEs

[0091] The retention rate of LEO in LEO-PEs was measured every day during storage at 4°C for 14 days. Initially, LEO was dissolved in n-hexane and its absorbance at 253 nm was measured to construct a standard curve. Subsequently, 900 μL of n-hexane was added to 100 μL of the emulsion, followed by centrifugation at 10,000 rpm for 2 min. After emulsion stratification, the supernatant was taken and diluted tenfold with n-hexane. According to the standard curve, the absorbance of the diluted supernatant was converted to the concentration of LEO. The retention rate of LEO in LEO-PE was calculated by the following equation:

[0092]

[0093] Among them C 0 and C t They represent the concentration of LEO at 0th day and the concentration of LEO at td, respectively.

[0094] 2.6 Optical microscope images of LEO-PEs

[0095] The microstructure of LEO-PEs droplets was observed with an E100 optical microscope using a 40× objective lens.

[0096] The optical microscope images of LEO-PEs and the particle size distribution at the 0th and 7th day of storage are shown in Figure 2. Figure 5 As shown, Figure 5 A 1 –A 4 corresponding to CS-Zein composite nanoparticles; Figure 5 B 1 –B 4 Corresponding to CS CP -Zein composite nanoparticles; Figure 5 C 1 –C 4 Corresponding to CS-Zein CP Composite nanoparticles; Figure 5 D 1 –D 4 Corresponding to CS CP -Zein CP Composite nanoparticles; Figure 5 E 1 –E 4 Correspondence (CS-Zein) CP Composite nanoparticles. Figure 5 It can be seen that by CS CP -Zein CP The stable Pickering emulsions with uniform droplet distribution and regular morphology remained stable after low-temperature storage. This indicates that compared with other composite nanoparticles, CS CP -Zein CP As a new and efficient Pickering emulsion stabilizer, it has shown great potential, thus highlighting its superiority in maintaining emulsion stability.

[0097] The stability, Zeta potential and retention rate of LEO in LEO-PEs emulsion are shown in Figure 2. Figure 6 As shown in (a)-(c) in the figure, it can be seen that CS CP -Zein CP Stable Pickering emulsions exhibit multiple advantages, including the following:

[0098] ① Improved emulsion stability: centrifugal stability 80.50%, significantly higher than other groups, such as (CS-Zein) CP The rate in the same group was 45.16%.

[0099] ② High Zeta potential: The surface charge density is increased, the electrostatic repulsion is enhanced, the droplet aggregation is reduced, and the dispersion is optimized.

[0100] ③ Long-term encapsulation and retention ability: Initial encapsulation rate 91.57%: significantly improved compared to CS-Zein (79.71%), effectively protecting the active ingredients of LEO. 14d retention rate 53.68%: CS-Zein is only 28.18%, with excellent sustained release performance, slowing down volatilization and oxidation.

[0101] Dispersion and dilution stability of LEO-PEs emulsions Figure 7 As shown, Figure 7 AE in the figure corresponds to composite nanoparticles: CS-Zein, CS CP -Zein, CS-Zein CP , CS CP -Zein CP and (CS-Zein) CP As can be seen in the figure: CS CP -Zein CP It has shown significant advantages in dilution applications. Its emulsion can still form a highly uniform suspension system after dilution, and its stability at room temperature can be maintained for more than 12 hours, far exceeding the actual process requirements. This feature makes CS CP -Zein CP It is an ideal stabilizer for coating, dipping and other processing scenarios that require multiple times, providing a long-term and reliable solution for food industry applications.

[0102] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0103] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification, characterized in that: The following steps are involved: CS is dissolved in acetic acid to obtain a CS solution; Zein is dispersed in an ethanol aqueous solution, and then the ethanol is evaporated and removed, and water is added to obtain a Zein solution, and the CS solution and the Zein solution are homogenized respectively; The Zein solution and the CS solution are modified by using DBD-CP equipment to obtain modified Zein solution and modified CS solution respectively; The modified CS solution was added to the modified Zein solution, mixed evenly and then freeze-dried in vacuum to obtain CS CP -Zein CP Composite nanoparticles.

2. The method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to claim 1, characterized in that: The pH values ​​of the CS solution and the Zein solution are both 4.

3. The method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to claim 1, characterized in that: When preparing the Zein solution, after removing the ethanol by evaporation, the volume of water added is equal to the volume of the ethanol removed.

4. The method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to claim 1, characterized in that: The concentration of the CS solution and the Zein solution was 1% w / v.

5. The method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to claim 1, characterized in that: The concentration of the acetic acid is 1% v / v; the concentration of the ethanol aqueous solution is 80% v / v.

6. The method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to claim 1, characterized in that: The modification treatment time of the DBD-CP equipment is 60s, the treatment voltage is set to 90kV, the frequency is 145Hz, the electrode gap is 30mm, the treatment medium is air, and the treatment temperature is 25℃.

7. The method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to claim 1, characterized in that: When preparing the composite nanoparticles, the volume ratio of the modified CS solution to the modified Zein solution is 1:

8.

8. Chitosan-zein composite nanoparticles modified by low-temperature plasma, characterized in that: The nanoparticles are prepared by the method for preparing chitosan-zein composite nanoparticles based on low-temperature plasma modification according to any one of claims 1 to 7.

9. Use of the chitosan-zein composite nanoparticles modified by low-temperature plasma according to claim 8 in the preparation of Pickering emulsion.

10. A Pickering emulsion, characterized in that The raw materials include the chitosan-zein composite nanoparticles modified by low-temperature plasma as described in claim 8.

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