A preparation method of egg yolk lipopeptide-curcumin composite nanoparticles

Abstract

The invention discloses a method for preparing egg yolk lipopeptide-curcumin composite nanoparticles, comprising the steps of: hydrolyzing fresh egg yolk with protease, centrifuging and taking the supernatant for spray drying, and extracting egg yolk lipopeptide using supercritical carbon dioxide; then adding the egg yolk lipopeptide to deionized water and stirring to obtain an egg yolk lipopeptide solution, dissolving curcumin powder in a NaOH solution, mixing the alkaline curcumin solution with the egg yolk lipopeptide solution, stirring at room temperature in the dark, adjusting the pH value of the mixed solution using an HCl solution, centrifuging the sample solution, taking the supernatant and freeze-drying, and obtaining egg yolk lipopeptide-curcumin composite nanoparticles. The prepared egg yolk lipopeptide-curcumin composite nanoparticles are more stable and have higher bioavailability than free curcumin.

Description

Technical Field

[0001] The invention belongs to the fields of food science and nanotechnology, and particularly relates to a method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles. Background Art

[0002] Turmeric has attracted widespread attention due to its traditional use as a spice, dye, and anti-inflammatory agent in Southeast Asia, as well as the positive results of modern pharmacological research. Turmeric has a variety of health benefits, including antibacterial, anti-inflammatory, antioxidant, anti-cancer, anti-arthritis, hepatoprotective, and neuroprotective properties. This is primarily due to its primary active polyphenol component, curcumin (a yellow extract). Adding curcumin to foods can provide functional properties that promote health and wellness.

[0003] However, curcumin has poor water solubility and is difficult to be absorbed by the epithelial cells of the small intestine. Even if it reaches the epithelial cells, the strong hydrophobicity of curcumin will cause it to be flushed back into the lumen by the efflux system. Secondly, curcumin is also very sensitive to light and temperature, and it is easy to undergo chemical degradation under certain conditions. Therefore, it is difficult to directly apply it to medicine, functional foods and conventional food processing, and encapsulation technology is required to maintain its long-term stability. Nanoencapsulation provides a closed microenvironment that can effectively improve the solubility and stability of curcumin and prevent its degradation. Previous studies have found that proteins and lecithin can effectively form nanocomplexes with curcumin, but nanocomplexes formed by single components have problems such as low encapsulation efficiency and insufficient stability. Summary of the Invention

[0004] [Technical Issues]

[0005] Provided are egg yolk lipopeptide-loaded curcumin nanoparticles and a preparation method thereof. The process operation is simple, no organic reagents are introduced, the nanoparticles are safe and have no toxic side effects, and can effectively improve the stability and bioaccessibility of curcumin.

[0006] [Technical solution]

[0007] In one aspect, a method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles is provided, comprising the following steps:

[0008] (1) After filtering and preheating the egg yolk liquid, mix it with 2000-6000u / g neutral protease and perform enzymatic hydrolysis under stirring;

[0009] (2) centrifuging the egg yolk solution after enzymatic hydrolysis in step (1), taking the supernatant and spray drying it to obtain egg yolk powder;

[0010] (3) extracting the egg yolk powder obtained in step (2) using supercritical carbon dioxide to prepare egg yolk lipopeptides having a protein nitrogen content of 58-65% and a phospholipid content of 26-33%;

[0011] (4) mixing the egg yolk lipopeptide obtained in step (3) with water to obtain an egg yolk lipopeptide solution, adjusting the pH value of the egg yolk lipopeptide solution to neutral to obtain a neutral egg yolk lipopeptide solution; dissolving curcumin powder in a NaOH solution to obtain an alkaline curcumin solution; mixing the alkaline curcumin solution with the neutral egg yolk lipopeptide solution, and stirring at room temperature in the dark to obtain a mixed solution; wherein the mass ratio of curcumin to egg yolk lipopeptide in the mixed solution is (0.5-5):50;

[0012] (5) adjusting the pH value of the mixed solution obtained in step (4) to 6.0-8.0, stirring in the dark, and then centrifuging. The supernatant was freeze-dried to obtain egg yolk lipopeptide-loaded curcumin nanoparticles.

[0013] In some embodiments, the process parameters of the supercritical carbon dioxide extraction in step (3) are: pressure of 30-40 MPa, temperature of 40-50° C.; and extraction time of 2-5 h.

[0014] In some embodiments, in step (4), the concentration of the egg yolk lipopeptide solution is 45-55 mg / mL; the concentration of the alkaline curcumin solution is 4-6 mg / mL; and the alkaline curcumin solution and the neutral egg yolk lipopeptide solution are mixed in a volume ratio of 1:5.

[0015] In some embodiments, in step (1), the enzymatic hydrolysis temperature is 40-60° C., and the enzymatic hydrolysis time is 210-240 min.

[0016] In some embodiments, in step (1), the egg yolk liquid is prepared by separating the egg yolk liquid from fresh eggs using an egg beater.

[0017] In some embodiments, in step (5), the centrifugation condition is 6000-8000 rpm at room temperature for 12-18 minutes.

[0018] In some embodiments, HCl solution and NaOH solution are used to adjust the pH value in step (4) and / or step (5).

[0019] In some embodiments, curcumin is replaced with other plant polyphenols.

[0020] On the other hand, provided are egg yolk lipopeptide-loaded curcumin nanoparticles prepared by the aforementioned method.

[0021] In another aspect, the present invention provides the use of the aforementioned egg yolk lipopeptide-loaded curcumin nanoparticles in the preparation of health food.

[0022] [Beneficial Effects]

[0023] The egg yolk lipopeptide prepared by the present invention using enzyme modification and supercritical carbon dioxide extraction technology can form egg yolk lipopeptide-curcumin composite nanoparticles with curcumin. Compared with free curcumin, the water solubility and stability are significantly improved, and the composite nanoparticles have higher bioavailability, bringing higher economic benefits to the food industry and the biopharmaceutical industry.

[0024] The egg yolk lipopeptide prepared by the present invention can not only form a non-covalent nanocomplex with hydrophobic polyphenols, significantly improving their stability, but also utilize the membrane affinity of endogenous phospholipids to improve their biomembrane barrier permeability, thereby increasing the bioaccessibility of the loaded hydrophobic polyphenols and thus improving their bioavailability. This provides a new approach for overcoming the technical difficulty of low bioavailability of plant polyphenols and has important scientific significance and practical value.

[0025] The process of the present invention is simple to operate, does not require the introduction of toxic organic reagents, has a safe and non-toxic carrier, is easy to operate, and has low cost. This feature makes the technology have good economic benefits, environmental benefits and application prospects.

[0026] The present invention discovered and confirmed that egg yolk lipopeptide has a significant synergistic effect in improving the water solubility, stability (encapsulation rate and 14-day retention rate, thermal stability) and bioaccessibility of curcumin compared with single egg yolk protein peptide and egg yolk lecithin. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The infrared spectra of free curcumin, egg yolk lipopeptide and egg yolk lipopeptide-curcumin nanoparticles;

[0028] Figure 2 Scanning electron micrographs of free curcumin A, egg yolk lipopeptide B, and egg yolk lipopeptide-curcumin nanoparticles C;

[0029] Figure 3 The thermal stability test results of free curcumin, egg yolk protein peptide-curcumin nanoparticles and egg yolk lipopeptide-curcumin nanoparticles are shown;

[0030] Figure 4 The experimental results of simulated gastrointestinal bioaccessibility of free curcumin, egg yolk protein peptide-curcumin nanoparticles and egg yolk lipopeptide-curcumin nanoparticles are presented. DETAILED DESCRIPTION

[0031] Detection method:

[0032] Determination of protein nitrogen content: Refer to GB 5009.5-2016 National Food Safety Standard Determination of Protein in Food.

[0033] Phospholipid content determination: Refer to GB / T 5537-2008 Grain and oil inspection - Determination of phospholipid content.

[0034] Determination of embedding efficiency (EE) and retention rate (RT): The loaded curcumin nanoparticles were centrifuged at 8000 rpm for 20 min (embedding efficiency determination) or not centrifuged (retention rate determination) to remove the unencapsulated curcumin precipitate. The supernatant was aspirated and diluted with anhydrous ethanol at a volume ratio of 1:100. The curcumin was fully extracted by shaking and the absorbance was measured at 420 nm using a UV-visible spectrophotometer. The curcumin content was determined using the standard curve y = 0.1465x + 0.0017 (R 2 =0.9948), and the embedding efficiency and 14-day room temperature storage retention rate were calculated using the following formula:

[0035]

[0036]

[0037] Stability determination: Particle size and zeta potential are important indicators of nanoparticle stability. For nanoparticles, smaller particle size and higher zeta potential indicate better stability. The droplet size distribution and charge (zeta potential) of curcumin-loaded nanoparticle dispersions and emulsions were measured at 25°C using a nanoparticle size and zeta potential analyzer. Prior to measurement, the dispersions and emulsions were diluted with deionized water and equilibrated for 60 seconds. The z-average particle size calculated from the particle size distribution was used as the particle size. The Smoluchowsky mathematical model was selected as the measurement mode, and the electrophoretic mobility measurements were converted to zeta potential values.

[0038] Example 1

[0039] A method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles comprises the following steps:

[0040] (1) Separate the egg yolk liquid from fresh eggs using an egg beater, filter and preheat the egg yolk liquid, mix it with neutral protease (2000u / g), and perform enzymatic hydrolysis at 50°C with stirring for 240min;

[0041] (2) centrifuging the egg yolk solution after enzymatic hydrolysis in step (1), taking the supernatant and spray drying it to obtain egg yolk powder;

[0042] (3) extracting the egg yolk powder obtained in step (2) with supercritical carbon dioxide to prepare egg yolk lipopeptides (protein nitrogen content 58-61%, phospholipid content 30-33%); wherein the process parameters of the supercritical carbon dioxide extraction are: extraction pressure of 30-40 MPa, extraction temperature of 40-50° C., and extraction time of 2-5 h;

[0043] (4) mixing the egg yolk lipopeptide obtained in step (3) with deionized water in a certain proportion to obtain an egg yolk lipopeptide solution with a concentration of 50 mg / mL; adjusting the pH value of the egg yolk lipopeptide solution to neutral with a 1 mol / L NaOH solution to obtain a neutral egg yolk lipopeptide solution; dissolving curcumin powder in a 0.1 mol / L NaOH solution in a certain proportion to obtain a 5 mg / mL alkaline curcumin solution; mixing the alkaline curcumin solution with the neutral egg yolk lipopeptide solution in a volume ratio of 1:5, stirring at room temperature in the dark, and obtaining a mixed solution;

[0044] (5) The pH value of the mixture obtained in step (4) was adjusted to 6.5 using 1 mol / L HCl solution. After stirring in the dark, the mixture was centrifuged at 8000 rpm for 15 min at room temperature. The supernatant was freeze-dried to obtain egg yolk lipopeptide-loaded curcumin nanoparticles.

[0045] Example 2

[0046] A method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles is described with reference to Example 1, except that the amount of neutral protease added in step (1) is 4000 u / g, and the egg yolk lipopeptide prepared in step (3) has a protein nitrogen content of 60-64% and a phospholipid content of 28-32%.

[0047] Example 3

[0048] A method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles is described with reference to Example 1, except that the amount of neutral protease added in step (1) is 6000 u / g, and the egg yolk lipopeptide prepared in step (3) has a protein nitrogen content of 62-65% and a phospholipid content of 26-30%.

[0049] Comparative Example 1

[0050] A method for preparing egg yolk protein peptide-loaded curcumin nanoparticles is described with reference to Example 2, except that the egg yolk lipopeptide in step (4) is replaced with egg yolk protein peptide (protein nitrogen content 89-91%, phospholipids <1%); wherein the preparation method of the egg yolk protein peptide (protein nitrogen content 89-91%, phospholipids <1%) comprises: removing the phospholipid component from the egg yolk lipopeptide prepared in Example 2 using ethanol, wherein the volume ratio of the egg yolk lipopeptide to the ethanol is 1:10.

[0051] Comparative Example 2

[0052] A method for preparing egg yolk lecithin-loaded curcumin nanoparticles is described with reference to Example 2, except that the egg yolk lipopeptide in step (4) is replaced with commercially available pure egg yolk lecithin.

[0053] Comparative Example 3

[0054] A method for preparing partially dephospholipidified egg yolk lipopeptide-loaded curcumin nanoparticles is disclosed, with reference to Example 2, except that the egg yolk lipopeptide in step (4) is replaced with partially dephospholipidified egg yolk lipopeptide (protein nitrogen content 71%, phospholipid content 20%); wherein the method for preparing the partially dephospholipidified egg yolk lipopeptide (protein nitrogen content 71%, phospholipid content 20%) comprises: partially dephospholipidating the egg yolk lipopeptide prepared in Example 2 using ethanol, wherein the volume ratio of the egg yolk lipopeptide to the ethanol is 1:3, to obtain the partially dephospholipidified egg yolk lipopeptide (protein nitrogen content 71%, phospholipid content 20%).

[0055] Comparative Example 4

[0056] A method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles is described with reference to Example 2, except that the neutral protease in step (1) is replaced by papain with the same enzyme activity unit.

[0057] Effect comparison:

[0058] Table 1 Comparison of the embedding efficiency (EE) of the curcumin nanoparticles obtained in different embodiments and comparative examples

[0059]

[0060] As shown in Table 1, the embedding efficiency of the egg yolk lipopeptide-loaded curcumin nanoparticles obtained in Examples 1 to 3 reached 61.51% or more, and the 14-day retention rate reached 84.4% or more, confirming that the dispersion system of the egg yolk lipopeptide-loaded curcumin nanoparticles prepared using egg yolk lipopeptide as the embedding wall material is the most stable, which may be related to its unique composition and strong electronegativity (Zeta potential is about -30 mV).

[0061] From the results of Comparative Example 1, it can be seen that when curcumin is encapsulated using egg yolk protein peptide as a wall material, the encapsulation rate and 14-day retention rate are lower than those in Example 2, confirming that the egg yolk protein peptide without phospholipids has a poor loading capacity for curcumin. This may be due to the lack of lecithin in the egg yolk protein peptide and the insufficient ability to self-assemble to form micelles.

[0062] From the results of Comparative Example 2, it can be seen that when curcumin is encapsulated using egg yolk lecithin as the wall material, the encapsulation efficiency and 14-day stability are much lower than those of Example 2. This may be related to the fewer hydrophobic binding sites and lower Zeta potential of egg yolk lecithin (compared to egg yolk lipopeptide).

[0063] In combination with Examples 1 to 3, Comparative Example 1 and Comparative Example 2, it can be seen that the egg yolk lipopeptide (protein nitrogen content 58-65%, phospholipid content 26-33%) prepared by directly using egg yolk liquid as a wall material has an embedding efficiency of curcumin (≥61.51%)> the embedding efficiency of curcumin (42.25%) of the egg yolk protein peptide alone (phospholipid removed, protein nitrogen 89-91%, phospholipid <1%) of Comparative Example 1 + the embedding efficiency of curcumin (14.97%) of the egg yolk lecithin alone of Comparative Example 2 as a wall material (57.22%). It can be seen that the egg yolk lipopeptide (protein nitrogen content 58-65%, phospholipid content 26-33%) directly prepared from egg yolk liquid as the wall material has an unexpected improvement in the "quantity" of curcumin encapsulation efficiency, resulting in a synergistic effect; after combination, the 14-day retention rate is also significantly improved compared with Comparative Example 1 and Comparative Example 2, confirming the improvement in stability; after combination, the Zeta potential is basically equivalent to that of the egg yolk protein peptide-loaded curcumin nanoparticles in Comparative Example 1.

[0064] From the results of Comparative Example 3, it can be seen that when the protein nitrogen content in the egg yolk lipopeptide is too high and the phospholipid content is too low, for example (protein nitrogen content 71%, phospholipid content 20%), the curcumin embedding efficiency will be significantly reduced and the 14-day storage stability will be reduced.

[0065] From Comparative Example 4, it can be seen that when papain is used, the encapsulation performance and stability of the egg yolk lipopeptide obtained at the same enzyme activity addition amount are worse than those of neutral protease, which may be related to the difference in the enzyme cleavage sites between them.

[0066] Taking the egg yolk lipopeptide-loaded curcumin nanoparticles prepared in Example 2 as an example, infrared spectroscopy analysis and micromorphology observation were performed on the egg yolk lipopeptide-loaded curcumin nanoparticles of the present invention, and the stability of the egg yolk lipopeptide-loaded curcumin nanoparticles of the present invention during heat treatment and the bioaccessibility during simulated in vitro digestion were evaluated by experiments.

[0067] (1) Fourier transform infrared spectroscopy

[0068] The structures of free curcumin, egg yolk lipopeptide, and egg yolk lipopeptide-curcumin nanoparticles (egg yolk lipopeptide-loaded curcumin nanoparticles prepared in Example 2) as well as the interaction between egg yolk lipopeptide and curcumin were analyzed by Fourier transform infrared spectroscopy. Figure 1 shown.

[0069] The infrared spectrum of free curcumin is at 3507 cm -1 There is an obvious absorption peak at 1628cm, which is the characteristic peak caused by the stretching vibration of phenolic hydroxyl groups on the benzene ring; -1 is C=O stretching vibration, 1267cm -1It is the stretching vibration of aromatic hydrocarbon CO, 807.5cm -1 It is the vibration of the benzene ring substituted at the ortho and para positions.

[0070] From the spectra of egg yolk lipopeptide and composite curcumin nanoparticles, we can see that the 3100-3500 cm -1 The peak at 1643 cm is caused by the stretching vibration of NH, -NH2 and -OH, indicating the presence of nitrogen-containing components or polar hydroxyl groups. -1 It is the amide I band peak, which is the characteristic absorption peak of protein, 2800-3000cm -1 It is the CH stretching vibration of alkanes and is the characteristic absorption peak of phospholipids. The formed egg yolk lipopeptide-curcumin nanoparticles have an absorption peak at 3507 cm -1 The absorption peak at 140 nm completely disappears and is almost completely consistent with the peak shape of egg yolk lipopeptide, which confirms that curcumin and egg yolk lipopeptide in the egg yolk lipopeptide-loaded curcumin nanoparticles of the present invention are completely encapsulated after being combined with each other through non-covalent interaction.

[0071] (2) Scanning electron microscopy

[0072] The morphological characteristics of free curcumin, egg yolk lipopeptide, and egg yolk lipopeptide-curcumin nanoparticles (egg yolk lipopeptide-loaded curcumin nanoparticles prepared in Example 2) were observed using a scanning electron microscope. The sample powder was sprayed with gold to be covered with a layer of metal, and then the microstructure of the sample was observed at 3 kV.

[0073] like Figure 2 As shown in the figure, under an acceleration voltage of 3kV and a magnification of 1000 times, free curcumin appears as solid rod-shaped particles under a wide field of view; while egg yolk lipopeptide and egg yolk lipopeptide-curcumin composite nanoparticles appear as loose round particles or sheet-like structures after freeze-drying, and their shapes are more regular than those of free curcumin.

[0074] (3) Thermal stability

[0075] The thermal stability of curcumin in curcumin composite nanoparticles was evaluated by the degradation rate of curcumin at 80 ° C. 1 mL of curcumin ethanol solution with a concentration of 10 mg / mL was added to 9 mL of distilled water and mixed evenly as a free curcumin solution. 8 mL of free curcumin solution, egg yolk protein peptide-curcumin nanoparticle solution (the egg yolk protein peptide-loaded curcumin nanoparticles prepared in Comparative Example 1 were dissolved in deionized water at a concentration of 50 mg / mL) or egg yolk lipopeptide-curcumin nanoparticle solution (the egg yolk lipopeptide-loaded curcumin nanoparticles prepared in Example 2 were dissolved in deionized water at a concentration of 50 mg / mL) in an amber glass bottle and heated at 80 ° C for 180 min. During the process, samples were taken regularly every 30 min, and the absorbance of the sample at 420 nm was measured by ultraviolet-visible spectrophotometer to calculate the remaining curcumin content in the system.

[0076] Curcumin retention rate (%) = curcumin loading concentration after heat treatment ÷ curcumin loading concentration before heat treatment × 100%

[0077] like Figure 3 As shown, the retention rate of free curcumin dropped to 20.37% after only 30 minutes in an 80°C environment; the retention rate of egg yolk protein peptide-curcumin nanoparticles dropped to below 50% after 30 minutes in an 80°C environment; for egg yolk lipopeptide-curcumin nanoparticles (egg yolk lipopeptide-loaded curcumin nanoparticles prepared in Example 2), the retention rate was still greater than 86% after 30 minutes in an 80°C environment, and the retention rate decreased more slowly as the heating time increased. The above results show that egg yolk lipopeptide encapsulation still has excellent protection for curcumin, and the thermal stability of curcumin in aqueous solution can be significantly improved by forming a nanocomposite between curcumin and egg yolk lipopeptide.

[0078] (4) Bioaccessibility

[0079] Simulated gastric fluid (SGF) is prepared by dissolving sodium chloride (2 g / L) and concentrated hydrochloric acid (7 mL / L) in deionized water. Simulated intestinal fluid (SIF) consists of three components: small intestinal stock solution, bile salt solution, and trypsin. The small intestinal stock solution is prepared by mixing calcium chloride (36.7 g / L) and sodium chloride (218.7 g / L) in deionized water; the bile salt solution is prepared by mixing porcine bile salts (54 g / L) in deionized water.

[0080] In vitro simulated digestion experiment is first to mix 0.4g egg yolk protein peptide-curcumin nanoparticle solution (curcumin nanoparticles of egg yolk protein peptide load prepared in comparative example 1) or egg yolk lipopeptide-curcumin nanoparticle solution (curcumin nanoparticles of egg yolk lipopeptide load prepared in embodiment 2) with 16mL SGF and stir and preheat to 37 DEG C, adjust the pH value of the mixed solution to 2.0;20mg pepsin is subsequently added, and digested in the dark for 2h at 37 DEG C;After the end, the gastric digestive fluid pH value is adjusted to 7.0 and 1.2mL small intestine storage solution, 10mg trypsin and 2.8mL bile salt solution are added, and digestion in the dark for 2h;All digestion processes strictly control the pH value change of solution. As a control, 1mL of curcumin ethanol solution with a concentration of 10mg / mL is added to 16mSGF and mixed evenly as a free curcumin solution.

[0081] During the digestion process, 1 mL of the digestion solution was collected every 30 minutes and the curcumin concentration was determined. At the end of the simulated digestion, 1 mL of the digestion solution was centrifuged at 5000 rpm for 5 minutes, and the curcumin content in the supernatant was determined.

[0082] Curcumin bioaccessibility (%) = curcumin content in the supernatant after digestion / total mass of curcumin before digestion × 100%

[0083] Depend on Figure 4 It can be seen that after 240 minutes of simulated digestion, the bioaccessibility of free curcumin was only 3.3%; in curcumin nanoparticles loaded with egg yolk protein peptides, the bioaccessibility of curcumin could reach 20.5%; in curcumin nanoparticles loaded with egg yolk lipopeptides, the bioaccessibility of curcumin was as high as 34.3%, which was nearly 10 times higher than that of free curcumin.

[0084] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing egg yolk lipopeptide-loaded curcumin nanoparticles, characterized in that: The following steps are involved: (1) Filter and preheat the egg yolk liquid, mix it with 2000~6000 u / g neutral protease, and perform enzymatic hydrolysis under stirring; (2) centrifuging the egg yolk solution after enzymatic hydrolysis in step (1), taking the supernatant and spray drying it to obtain egg yolk powder; (3) extracting the egg yolk powder obtained in step (2) using supercritical carbon dioxide to prepare egg yolk lipopeptides having a protein nitrogen content of 58-65% and a phospholipid content of 26-33%; (4) mixing the egg yolk lipopeptide obtained in step (3) with water to obtain an egg yolk lipopeptide solution, adjusting the pH value of the egg yolk lipopeptide solution to neutral to obtain a neutral egg yolk lipopeptide solution; dissolving curcumin powder in a NaOH solution to obtain an alkaline curcumin solution; The alkaline curcumin solution and the neutral egg yolk lipopeptide solution are mixed and stirred at room temperature in the dark to obtain a mixed solution; wherein the mass ratio of curcumin to egg yolk lipopeptide in the mixed solution is (0.5-5):50; (5) The pH value of the mixed solution obtained in step (4) was adjusted to 6.0-8.0, stirred in the dark, and then centrifuged. The supernatant was freeze-dried to obtain egg yolk lipopeptide-loaded curcumin nanoparticles.

2. The method according to claim 1, wherein The process parameters of supercritical carbon dioxide extraction in step (3) are: pressure of 30-40 MPa, temperature of 40-50 °C; extraction time of 2-5 h.

3. The method according to claim 1, wherein In step (4), the concentration of the egg yolk lipopeptide solution is 45-55 mg / mL; the concentration of the alkaline curcumin solution is 4-6 mg / mL; and the alkaline curcumin solution and the neutral egg yolk lipopeptide solution are mixed in a volume ratio of 1:

5.

4. The method according to claim 1, wherein In step (1), the enzymatic hydrolysis temperature is 40-60°C, and the enzymatic hydrolysis time is 210-240 min.

5. The method according to claim 1, wherein In step (1), the egg yolk liquid is prepared by separating the egg yolk liquid from fresh eggs using an egg beater.

6. The method according to claim 1, wherein In step (5), the centrifugation condition is 6000-8000 rpm at room temperature for 12-18 min.

7. The method according to claim 1, characterized in that In step (4) and / or step (5), HCl solution and NaOH solution are used to adjust the pH value.

8. Egg yolk lipopeptide-loaded curcumin nanoparticles prepared by the method according to any one of claims 1 to 7.

9. Use of the egg yolk lipopeptide-loaded curcumin nanoparticles according to claim 8 in the preparation of health food.

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