Starch-lysozyme nanogel-stabilized Pickering emulsion as well as preparation method and application thereof

Abstract

The invention provides a starch-lysozyme nanogel-stabilized Pickering emulsion and a preparation method and application thereof, and relates to the technical field of biological material encapsulation, the preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion comprises the following steps: S10, mixing starch and lysozyme, and heating to obtain starch-lysozyme nanogel; and S20, mixing the starch-lysozyme nanogel with an oil phase, so as to obtain the Pickering emulsion with the stable starch-lysozyme nanogel. According to the technical scheme, starch and lysozyme are mixed under specific conditions and heated to form nanogel, the nanogel can be effectively adsorbed on an oil-water interface to form a stable Pickering emulsion, and compared with a traditional emulsifier, the starch-lysozyme nanogel has higher interfacial activity and stability, and the stability of the starch-lysozyme nanogel is improved. The long-term stability and the anti-shearing capability of the emulsion can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsion preparation, and particularly relates to a Pickering emulsion stabilized by starch-lysozyme nanogel, a preparation method thereof, and an application thereof. Background Art

[0002] In the fields of food and medicine, the application range of fat-soluble bioactive substances such as β-carotene is limited due to the limitations of its low water solubility and bioavailability. In order to improve its stability and bioavailability, traditional methods usually adopt technologies such as microencapsulation, emulsion, gel, and nanoparticles. However, these methods still have deficiencies in terms of stability, loading capacity, and release control. In particular, emulsion systems are prone to problems such as droplet aggregation, gravitational separation, and rupture during storage.

[0003] In recent years, Pickering emulsion, as an emulsion system stabilized by solid particles, has attracted extensive attention due to its good interfacial adsorption and anti-aggregation characteristics. Traditional Pickering emulsion systems mainly use inorganic nanoparticles (such as silica, iron oxide, etc.) as stabilizers. These inorganic particles have good stability, but have limitations in terms of biocompatibility and safety. Summary of the Invention

[0004] The main object of the present invention is to propose a Pickering emulsion stabilized by starch-lysozyme nanogel, a preparation method thereof, and an application thereof, aiming to improve the stability of the Pickering emulsion system for loading bioactive substances.

[0005] To achieve the above object, the present invention proposes a preparation method of a Pickering emulsion stabilized by starch-lysozyme nanogel, comprising the following steps:

[0006] S10. Mix starch and lysozyme and heat to obtain starch-lysozyme nanogel;

[0007] S20. Mix the starch-lysozyme nanogel with an oil phase to obtain a Pickering emulsion stabilized by starch-lysozyme nanogel.

[0008] In one embodiment, the starch includes at least one of carboxymethyl starch, cationic starch, soluble starch, and OSA starch.

[0009] In one embodiment, the mass ratio of starch to lysozyme is (1-10):1; and / or,

[0010] In the Pickering emulsion stabilized by starch-lysozyme nanogel, the mass proportion of the starch-lysozyme nanogel is 0.1% - 0.5%.

[0011] In one embodiment, step S10 includes the following steps:

[0012] S11. Mix starch with water to obtain an aqueous starch solution, and mix lysozyme with water to obtain a lysozyme solution;

[0013] S12. Mix the aqueous starch solution and the lysozyme solution and then heat to obtain starch-lysozyme nanogel.

[0014] In one embodiment, in step S11, the mixing method is magnetic stirring;

[0015] wherein, the rotation speed of the magnetic stirring is 600-1000 rpm; and / or,

[0016] the duration of the magnetic stirring is 270-330 min.

[0017] In one embodiment, in step S12, the mixing method is magnetic stirring, the rotation speed of the magnetic stirring is 600-1000 rpm, and the duration of the magnetic stirring is 20-40 min; and / or,

[0018] the heating temperature is 80 °C, and the heating duration is 30-60 min.

[0019] In one embodiment, in step S20, the mixing method is high-speed dispersion mixing, the rotation speed of the high-speed dispersion mixing is 12000-15000 rpm, and the duration of the high-speed dispersion mixing is 1-5 min.

[0020] The present invention also provides a Pickering emulsion stabilized by starch-lysozyme nanogel, and the Pickering emulsion stabilized by starch-lysozyme nanogel is prepared by the preparation method of the Pickering emulsion stabilized by starch-lysozyme nanogel as described above.

[0021] The present invention also provides an application of a Pickering emulsion stabilized by starch-lysozyme nanogel in coating bioactive substances, and the Pickering emulsion stabilized by starch-lysozyme nanogel is the Pickering emulsion stabilized by starch-lysozyme nanogel as described above.

[0022] In one embodiment, the bioactive substance is coated in the oil phase; or,

[0023] the bioactive substance is coated in the starch-lysozyme nanogel.

[0024] The technical solution of the present invention forms a nano-gel by mixing starch and lysozyme under specific conditions and heating. This nano-gel can effectively adsorb on the oil-water interface to form a stable Pickering emulsion. Compared with traditional emulsifiers, the starch-lysozyme nano-gel has higher interfacial activity and stability, and can significantly improve the long-term stability and shear resistance of the emulsion. By using starch and lysozyme as emulsifiers to replace traditional chemically synthesized emulsifiers, the risk of chemical residues in the product is reduced, and the safety and environmental friendliness of the product are improved. The Pickering emulsion stabilized by the starch-lysozyme nano-gel has good stability and functionality, and its application scope can be extended from traditional food and daily chemical fields to multiple fields such as medicine and biotechnology, showing broad application prospects. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a graph of the experimental results of the stability detection of the Pickering emulsion in Examples 1 to 6 provided by the present invention;

[0027] Figure 2 It is a graph of the detection results of particle size and potential in the stability detection experiment of the Pickering emulsion in Examples 1 to 6 provided by the present invention;

[0028] Figure 3 It is a graph of the experimental results of the heat resistance detection of the Pickering emulsion in Examples 12 and 13 provided by the present invention;

[0029] Figure 4 It is a graph of the detection results of particle size in the heat resistance detection experiment of the Pickering emulsion in Examples 12 and 13 provided by the present invention;

[0030] Figure 5 It is a graph of the detection results of potential in the heat resistance detection experiment of the Pickering emulsion in Examples 12 and 13 provided by the present invention;

[0031] Figure 6 It is a graph of the experimental results of the encapsulation rate detection of the Pickering emulsion in Examples 12 and 13 provided by the present invention;

[0032] Figure 7 It is a graph of the experimental results of the 3D printing of the Pickering emulsion in Example 13 provided by the present invention.

[0033] The implementation, functional features and advantages of the present invention will be further described with reference to the accompanying drawings in combination with embodiments. Detailed implementation manners

[0034] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention.

[0035] It should be noted that for those conditions not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0036] At present, as an emulsion system stabilized by solid particles, Pickering emulsion has attracted wide attention due to its good interfacial adsorption and anti-aggregation characteristics. Traditional Pickering emulsion systems mainly use inorganic nanoparticles (such as silica, iron oxide, etc.) as stabilizers. These inorganic particles have good stability, but there are limitations in biocompatibility and safety.

[0037] In view of this, the present invention proposes a preparation method of a Pickering emulsion stabilized by starch-lysozyme nanogel, including the following steps: S10. Mix starch and lysozyme and then heat to obtain starch-lysozyme nanogel; S20. Mix the starch-lysozyme nanogel with an oil phase to obtain a Pickering emulsion stabilized by starch-lysozyme nanogel.

[0038] The technical solution of the present invention forms a nanogel by mixing starch and lysozyme under specific conditions and heating. This nanogel can effectively adsorb on the oil-water interface to form a stable Pickering emulsion. Compared with traditional emulsifiers, the starch-lysozyme nanogel has higher interfacial activity and stability, and can significantly improve the long-term stability and shear resistance of the emulsion; by using starch and lysozyme as emulsifiers to replace traditional chemically synthesized emulsifiers, the risk of chemical residues in the product is reduced, and the safety and environmental friendliness of the product are improved. The Pickering emulsion stabilized by the starch-lysozyme nanogel has good stability and functionality, and its application scope can be extended from traditional food and daily chemical fields to multiple fields such as medicine and biotechnology, showing broad application prospects.

[0039] In one embodiment, the starch includes at least one of carboxymethyl starch, cationic starch, soluble starch, and OSA starch.

[0040] The technical solution of the present invention by adopting carboxymethyl starch, due to the carboxymethyl groups on its molecular chain, has good water solubility and hydrophilicity, can more effectively combine with lysozyme to form a nanogel, further enhancing its adsorption ability and stability at the oil-water interface, thereby preparing a more stable and uniformly dispersed Pickering emulsion; by adopting cationic starch, it can adsorb on the oil-water interface and prevent droplet coalescence through electrostatic interaction and steric hindrance effect. Since it is positively charged, it can provide electrostatic repulsion force, which helps to maintain the stability of the emulsion; by adopting soluble starch, it can form a solution in water, increasing the viscosity of the aqueous phase. This thickening effect can help control the fluidity of the emulsion and prevent droplet sedimentation, thereby indirectly improving the stability of the emulsion; by adopting OSA starch (octenyl succinic anhydride starch), the starch modified by OSA has a hydrophobic part that can combine with oil, while the hydrophilic part contacts the aqueous phase, thus forming a physical barrier at the interface to prevent the droplets in the emulsion from aggregating and merging, and further improving the stability of the emulsion.

[0041] In one embodiment, the mass ratio of starch to lysozyme is (1-10):1; and / or, in the Pickering emulsion stabilized by the starch-lysozyme nanogel, the mass fraction of the starch-lysozyme nanogel is 0.1%-0.5%.

[0042] The technical solution of the present invention can achieve the optimal nano-gel formation conditions by adjusting the mass ratio of starch to lysozyme to (1-10):1, so that lysozyme can fully bind to starch molecules to form nano-gel particles with complete structure and uniform distribution. These particles form a dense particle layer at the oil-water interface, significantly improving the stability of the emulsion and preventing the aggregation and stratification of emulsion droplets. By adjusting the mass ratio of starch-lysozyme nano-gel to be 0.1%-0.5%, it can not only ensure that the emulsion has excellent physical stability, but also avoid the problems of increased cost and possible over-performance caused by excessive addition. Reasonably controlling the addition amount of nano-gel helps to find the best balance between emulsion performance and economy.

[0043] In one embodiment, step S10 includes the following steps: S11. Mix starch with water to obtain a starch aqueous solution, and mix lysozyme with water to obtain a lysozyme solution; S12. Mix the starch aqueous solution and the lysozyme solution and then heat to obtain a starch-lysozyme nano-gel.

[0044] The technical solution of the present invention can independently control the concentration and temperature of the two components by separately preparing the starch aqueous solution and the lysozyme solution, ensuring that they are in the most suitable state before mixing. In this way, during the mixing and heating process, starch and lysozyme can interact more fully to form nano-gels with more uniform structure and better performance.

[0045] In one embodiment, in step S11, the mixing method uses magnetic stirring; wherein, the rotation speed of the magnetic stirring is 600-1000 rpm; and / or, the duration of the magnetic stirring is 270-330 min.

[0046] The technical solution of the present invention can ensure a highly uniform dispersion state of starch and water, lysozyme and water in the mixing stage by adjusting the rotation speed and duration of magnetic stirring, thereby promoting their complete dissolution.

[0047] In one embodiment, in step S12, the mixing method uses magnetic stirring, the rotation speed of the magnetic stirring is 600-1000 rpm, the duration of the magnetic stirring is 20-40 min; and / or, the heating temperature is 80 °C, and the heating duration is 30-60 min.

[0048] The technical solution of the present invention adjusts the rotation speed and duration of magnetic stirring, which can effectively promote the rapid and uniform mixing of the starch aqueous solution and the lysozyme solution, ensure the full contact and reaction of the two during the heating process, and is beneficial to the formation of starch-lysozyme nano-gels with complete structure and stable performance; by adjusting the heating temperature and duration, it can effectively promote the rapid and uniform mixing of the starch aqueous solution and the lysozyme solution, ensure the full contact and reaction of the two during the heating process, and is beneficial to the formation of starch-lysozyme nano-gels with complete structure and stable performance.

[0049] In one embodiment, in step S20, the mixing method uses high-speed dispersion mixing. The rotation speed of the high-speed dispersion mixing is 12,000 - 15,000 rpm, and the duration of the high-speed dispersion mixing is 1 - 5 min.

[0050] The technical solution of the present invention can generate strong shear force by adjusting the rotation speed and duration of high-speed dispersion mixing, prompting the oil phase to mix rapidly and uniformly with the water phase containing starch-lysozyme nanogel, forming tiny and uniformly distributed emulsion droplets, significantly improving the dispersion uniformity of the emulsion and the consistency of the microstructure; the instant high-intensity shear during high-speed dispersion helps the starch-lysozyme nanogel to form a dense particle film at the oil-water interface, enhancing the interfacial stability of the emulsion, preventing the aggregation and stratification of emulsion droplets, and enabling the emulsion to maintain good stability even under long-term storage or changes in the external environment.

[0051] The present invention also proposes a Pickering emulsion stabilized by starch-lysozyme nanogel, and the Pickering emulsion stabilized by starch-lysozyme nanogel is prepared according to the preparation method of the Pickering emulsion stabilized by starch-lysozyme nanogel as described above.

[0052] Since the Pickering emulsion stabilized by this starch-lysozyme nanogel adopts all the technical solutions of the above all embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0053] The present invention also proposes an application of a Pickering emulsion stabilized by starch-lysozyme nanogel in coating bioactive substances, and the Pickering emulsion stabilized by starch-lysozyme nanogel is the Pickering emulsion stabilized by starch-lysozyme nanogel as described above.

[0054] Since this application method adopts all the technical solutions of the above all embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0055] In one embodiment, the bioactive substance is coated in the oil phase; or, the bioactive substance is coated in the starch-lysozyme nanogel.

[0056] The following further elaborates the technical solution of the present invention in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0057] Example 1

[0058] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel, and its preparation method includes the following steps:

[0059] 1. Weigh 1 g of carboxymethyl starch (CMS) and dissolve it in 20 mL of deionized water to make its concentration 5% (w / v), and stir it on a magnetic stirrer at a speed of 800 rpm for 5 hours. Weigh 1 g of lysozyme (Ly) and dissolve it in 10 mL of deionized water to make its concentration 10% (w / v), and stir it on a magnetic stirrer at a speed of 800 rpm for 5 hours.

[0060] 2. Mix the dissolved CMS and Ly in a ratio of 1:1, and stir it on a magnetic stirrer at a speed of 800 rpm for 30 minutes to prepare carboxymethyl starch-lysozyme complex (CMS-Ly COAs) with a concentration of 5%. Heat the prepared CMS-Ly COAs in a water bath at 80 °C for 45 minutes to obtain carboxymethyl starch-lysozyme nanogel (CMS-LyNGs) with a concentration of 5%.

[0061] 3. Mix CMS-Ly NGs and soybean oil in a ratio of 2:8 (v / v), and shear it on a high-speed disperser at a speed of 13000 rpm for 3 minutes to obtain a Pickering emulsion (CL-NGs-HIPEs) stabilized by CMS-Ly NGs.

[0062] Example 2

[0063] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel, and its preparation method is similar to that in Example 1, except that the mass ratio of CMS and Ly is 2:1.

[0064] Example 3

[0065] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel, and its preparation method is similar to that in Example 1, except that the mass ratio of CMS and Ly is 3:2.

[0066] Example 4

[0067] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel, and its preparation method is similar to that in Example 1, except that the mass ratio of CMS and Ly is 3:1.

[0068] Example 5

[0069] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel, and its preparation method is similar to that in Example 1, except that the mass ratio of CMS and Ly is 4:1.

[0070] Example 6

[0071] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel. Its preparation method is similar to that in Example 1, except that the mass ratio of CMS to Ly is 5:1.

[0072] Example 7

[0073] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel. Its preparation method is similar to that in Example 1, except that Step 1 includes the following steps:

[0074] Weigh 0.5 g of carboxymethyl starch (CMS) and dissolve it in 10 mL of deionized water to make its concentration 5% (w / v), and stir it on a magnetic stirrer at a speed of 800 rpm for 5 hours. Weigh 0.5 g of lysozyme (Ly) and dissolve it in 5 mL of deionized water to make its concentration 10% (w / v), and stir it on a magnetic stirrer at a speed of 800 rpm for 5 hours.

[0075] Example 8

[0076] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel. Its preparation method is similar to that in Example 6, except that the mass ratio of CMS to Ly is 2:1.

[0077] Example 9

[0078] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel. Its preparation method is similar to that in Example 6, except that the mass ratio of CMS to Ly is 3:1.

[0079] Example 10

[0080] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel. Its preparation method is similar to that in Example 6, except that the mass ratio of CMS to Ly is 4:1.

[0081] Example 11

[0082] This example provides a Pickering emulsion stabilized by starch-lysozyme nanogel. Its preparation method is similar to that in Example 6, except that the mass ratio of CMS to Ly is 5:1.

[0083] Example 12

[0084] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the CMS-Ly NGs with a concentration of 3% and soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CL-NGs-HIPEs@β-CE) with β-carotene embedded in CMS-Ly NGs-stabilized.

[0085] Example 13

[0086] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the CMS-Ly NGs (CMS-Ly-EGCG NGs) embedded with 0.2% (w / v) EGCG and soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CLE0.2-NGs-HIPEs@β-CE) with β-carotene embedded in EGCG-enhanced stable CMS-Ly NGs. Ensure its stability under various storage conditions by measuring the particle size, zeta potential, antioxidant property, and centrifugal stability of the emulsion.

[0087] Example 14

[0088] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the CMS-Ly NGs (CMS-Ly-EGCG NGs) embedded with 0.3% (w / v) EGCG and soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CLE0.3-NGs-HIPEs@β-CE) with β-carotene embedded in EGCG-enhanced stable CMS-Ly NGs. Ensure its stability under various storage conditions by measuring the particle size, zeta potential, antioxidant property, and centrifugal stability of the emulsion.

[0089] Example 15

[0090] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the CMS-LyNGs (CMS-Ly-EGCG NGs) entrapping 0.4% (w / v) EGCG with soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CLE0.4-NGs-HIPEs@β-CE) in which β-carotene is entrapped in EGCG-enhanced and stabilized CMS-Ly NGs. Ensure its stability under various storage conditions by measuring the particle size, zeta potential, antioxidant property, and centrifugal stability of the emulsion.

[0091] Example 16

[0092] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the CMS-LyNGs (CMS-Ly-EGCG NGs) entrapping 0.5% (w / v) EGCG with soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CLE0.5-NGs-HIPEs@β-CE) in which β-carotene is entrapped in EGCG-enhanced and stabilized CMS-Ly NGs. Ensure its stability under various storage conditions by measuring the particle size, zeta potential, antioxidant property, and centrifugal stability of the emulsion.

[0093] Example 17

[0094] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the CMS-Ly NGs with an optimal concentration of 2.5% with soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CL-NGs-HIPEs@β-CE) in which β-carotene is entrapped in CMS-Ly NGs-stabilized. Measure the particle size, zeta potential, and centrifugal stability of the emulsion to ensure its stability and encapsulation efficiency.

[0095] Example 18

[0096] Weigh 0.1 g of β-carotene (β-CE) and dissolve it in 100 mL of soybean oil. Continuously stir it overnight in the dark on a magnetic stirrer to obtain a β-carotene dispersion with a concentration of 0.1% (w / v). Mix the optimal concentration of 2.5% CMS-Ly NGs encapsulating 0.2% (w / v) EGCG with soybean oil at a ratio of 2:8 (v / v), and shear it at a speed of 13,000 rpm for 3 minutes on a high-speed disperser to obtain a Pickering emulsion (CLE0.2-NGs-HIPEs@β-CE) in which β-carotene is encapsulated in EGCG-enhanced stable CMS-Ly NGs. By measuring the particle size, zeta potential, antioxidant property, and centrifugal stability of the emulsion, ensure its stability under various storage conditions.

[0097] Stability detection experiment

[0098] The stability of Pickering emulsion is closely related to its emulsification efficiency and the ability of interfacial active solid particles to cover the oil-water interface. As Figure 1 and Figure 2 shown, the appearance diagrams ( Figure 1 ), particle sizes, and zeta potentials ( Figure 2 ) of Pickering emulsions stabilized by different concentrations of CMS-Ly NGs under fixed oil phase conditions. As can be seen from Figure 1 , after inverting different concentrations of CL-NGs-HIPEs, only the concentrations of CMS-Ly NGs of 1.5%, 2.0%, 3.0%, and 4.0% (v / v) can maintain a stable state. By measuring their particle sizes and zeta potentials, the particle size of CL-NGs-HIPEs first decreases and then increases with the increase of the concentration of CMS-Ly NGs, and reaches the minimum value of 16.7 ± 0.95 μm when the concentration of CMS-Ly NGs is 3.0%. The ζ-potential is a parameter for evaluating the stability of the emulsion. Generally, when the absolute value of the potential is less than 25 mV, the electrostatic repulsion weakens, and particles or molecules are prone to coagulation or aggregation due to Brownian motion, destroying the dispersion system; on the contrary, when the potential is greater than 25 mV, it helps to increase the electrostatic repulsion between particles or molecules, reduce the coagulation or aggregation phenomenon, and improve the stability of the dispersion system. Figure 2 In

[0099] Thermal stability detection experiment

[0100] Evaluate the thermal stability of CL-NGs-HIPEs and CLE0.2-NGs-HIPEs by heating them at different temperature conditions (37 °C, 60 °C, and 90 °C) for 30 min. AsFigures 3 to 5 Represent the appearance, particle size, and potential after heating, respectively. Figure 3 After heat treatment at different temperatures, the appearance diagrams of CL-NGs-HIPEs and CLE0.2-NGs-HIPEs remained stable after being placed upside down for a period of time; from Figure 4 and Figure 5 it can be seen that there was no significant difference in the particle size and potential of CL-NGs-HIPEs after heating at different temperatures (P>0.05). However, after heating at different temperatures, the particle size of CLE0.2-NGs-HIPEs increased from 18.6±0.24μm to 25.5±0.29μm, showing a significant difference (P<0.05), and the absolute value of the potential was around 50mV, with no significant difference (P>0.05). This is because polyphenols can intensify the movement of emulsion droplets during heat treatment, and the emulsion droplets collide with each other, resulting in an increase in their particle size. In summary, both CLE0.2-NGs-HIPEs and CL-NGs-HIPEs have good heat resistance.

[0101] Entrapment efficiency detection experiment

[0102] The entrapment efficiencies of β-CE in CL-NGs-HIPEs and CLE0.2-NGs-HIPEs are as Figure 6 shown. The entrapment efficiencies of CL-NGs-HIPEs and CLE0.2-NGs-HIPEs for β-CE are 87.39% and 88.25%, respectively, proving that both CL-NGs-HIPEs and CLE0.2-NGs-HIPEs have good entrapment efficiencies for β-CE.

[0103] 3D printing experiment

[0104] The parameter settings of the 3D printer (Biomarker 2i, Shangpu Biotech, China) are as follows: the inner diameter of the nozzle is 1.2mm, the nozzle height is 2.5mm, the filling density is 100%, and the nozzle movement speed is set to 20mm 3 / s when moving forward and 30mm 3 / s when retracting. The extrusion speed is set to 10mm 3 / s. Input the model into the printer and capture and record the shape of the printed 3D model.

[0105] The 3D printing experiment was carried out using the Pickering emulsion provided in Example 13. The experimental results are as Figure 7 shown. It can be seen that the model structure printed by the Pickering emulsion 3D printing is complete and does not show obvious collapse or other adverse phenomena, and can maintain a stable shape. This indicates that the Pickering emulsion can be directly used as a printing material to print three-dimensional structured products.

[0106] The above are only the preferred embodiments of the present invention, and do not thereby limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, is included within the patent protection scope of the present invention.

Claims

1. A preparation method of a starch-lysozyme nanogel-stabilized Pickering emulsion, characterized in that, It includes the following steps: S10. Mix starch and lysozyme and then heat to obtain starch-lysozyme nanogel; S20. Mix the starch-lysozyme nanogel with the oil phase to obtain a Pickering emulsion stabilized by the starch-lysozyme nanogel.

2. The preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion according to claim 1, wherein, The starch includes at least one of carboxymethyl starch, cationic starch, soluble starch, and OSA starch.

3. The preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion according to claim 1, wherein The mass ratio of starch to lysozyme is (1-10):1; and / or, In the Pickering emulsion stabilized by the starch-lysozyme nanogel, the mass proportion of the starch-lysozyme nanogel is 0.1% - 0.5%.

4. The preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion according to claim 1, characterized in that, Step S10 includes the following steps: S11. Mix starch with water to obtain a starch aqueous solution, and mix lysozyme with water to obtain a lysozyme solution; S12. Mix the starch aqueous solution and the lysozyme solution and then heat to obtain starch-lysozyme nanogel.

5. The preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion according to claim 4, characterized in that, In step S11, the mixing method is magnetic stirring; wherein, the rotation speed of the magnetic stirring is 600 - 1000 rpm; and / or, the duration of the magnetic stirring is 270 - 330 min.

6. The preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion according to claim 4, characterized in that, In step S12, the mixing method is magnetic stirring, the rotation speed of the magnetic stirring is 600 - 1000 rpm, and the duration of the magnetic stirring is 20 - 40 min; and / or, the heating temperature is 80 °C, and the heating duration is 30 - 60 min.

7. The preparation method of the starch-lysozyme nanogel-stabilized Pickering emulsion according to claim 1, characterized in that, In step S20, the mixing method is high-speed dispersion mixing, the rotation speed of the high-speed dispersion mixing is 12000 - 15000 rpm, and the duration of the high-speed dispersion mixing is 1 - 5 min.

8. A starch-lysozyme nanogel-stabilized Pickering emulsion, characterized in that, The Pickering emulsion stabilized by the starch-lysozyme nanogel is prepared by the preparation method of the Pickering emulsion stabilized by the starch-lysozyme nanogel according to any one of claims 1 to 7.

9. Application of a starch-lysozyme nanogel-stabilized Pickering emulsion in coating bioactive substances, characterized in that, The Pickering emulsion stabilized by the starch-lysozyme nanogel is the Pickering emulsion stabilized by the starch-lysozyme nanogel according to claim 8.

10. The application according to claim 8, characterized in that, The bioactive substance is coated in the oil phase; or, The bioactive substance is coated in the starch-lysozyme nanogel.

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