A whey protein-curcumin-chitosan ternary nanocomposite and a preparation method and application thereof

Abstract

The application discloses a whey protein-curcumin-chitosan ternary nanocomposite and a preparation method and application thereof, and belongs to the technical field of nanomaterials. The preparation method of the ternary nanocomposite comprises the following steps: mixing a solution of whey protein and a solution of curcumin to obtain a first reaction system, performing a first reaction, and obtaining a whey protein-curcumin composite; then adding a solution of chitosan to obtain a second reaction system, performing a second reaction, and obtaining the whey protein-curcumin-chitosan ternary nanocomposite. The ternary nanocomposite takes whey protein and cationic polysaccharide chitosan as carrier materials, and takes curcumin as an active ingredient. Based on hydrophobic interaction, hydrogen bonding and electrostatic interaction, the nanocomposite with a core-shell structure is formed by one-step self-assembly. The nanocomposite has high encapsulation efficiency, good physicochemical stability, and a pH-responsive release mechanism, and thus has digestion stability.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, and particularly relates to a whey protein-curcumin-chitosan ternary nanocomposite, its preparation method, and its application. Background Technology

[0002] Curcumin ( Curcumin Curcumin (abbreviated as Cur) is a natural polyphenolic compound extracted from the rhizome of turmeric, possessing various biological activities such as antioxidant, anti-inflammatory, and anti-tumor effects. However, curcumin has poor water solubility and is highly sensitive to environmental factors such as temperature, pH, light, and oxygen. It is easily degraded during processing, storage, and gastrointestinal transit, especially in the neutral to slightly alkaline environment of the intestine, where its stability decreases significantly, resulting in extremely low oral bioavailability and severely limiting its efficacy in vivo.

[0003] To address the issues of poor solubility and insufficient stability of curcumin, current research primarily focuses on improving delivery systems, commonly including nanocomposites, microcapsules, liposomes, and Pickering emulsions. Among these, protein- and polysaccharide-based nanocomposites have attracted significant attention for curcumin delivery due to their readily available materials, mild preparation conditions, and ability to spontaneously assemble through non-covalent interactions. However, existing protein- and polysaccharide-based curcumin nanocomposites struggle to effectively balance loading efficiency and protective efficacy.

[0004] Therefore, how to obtain a curcumin nanocomposite that balances load efficiency and protective effect is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To overcome the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a one-step self-assembly method for preparing a whey protein-curcumin-chitosan ternary nanocomposite. This method uses whey protein and cationic polysaccharide chitosan as carrier materials, and curcumin as the active ingredient. Based on hydrophobic interactions, hydrogen bonds, and electrostatic interactions, a core-shell structured nanocomposite is formed through one-step self-assembly. Whey protein (WPI) efficiently loads curcumin through hydrophobic interactions and hydrogen bonds to form the core; chitosan (CS) protonates and becomes positively charged under acidic conditions, forming a protective shell on the surface of the composite through electrostatic attraction. In gastric juice, the chitosan shell weakens the enzymatic hydrolysis of the protein carrier by pepsin through steric hindrance and electrostatic repulsion. After entering the intestine, as the pH increases, the amino groups of chitosan undergo deprotonation, enhancing the hydrophobic interactions between molecular chains and forming a more compact aggregate state. Simultaneously, the overall structure of the composite gradually loosens, allowing curcumin to be slowly released as the core gradually disintegrates. This pH-responsive release mechanism enables the composite to possess both high encapsulation efficiency and good physicochemical and digestive stability.

[0006] Another objective of this invention is to provide a whey protein-curcumin-chitosan ternary nanocomposite prepared by the above method.

[0007] Another objective of this invention is to provide an application of a whey protein-curcumin-chitosan ternary nanocomposite. Based on the synergistic effect of the high loading capacity of whey protein and the protective function of the outer layer of chitosan, this invention improves the sustained release and bioavailability of curcumin in the gastrointestinal environment. At the same time, the good colloidal stability and digestive stability of this nanocomposite enable the application of curcumin in drug delivery, health products or functional foods.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A method for preparing a whey protein-curcumin-chitosan ternary nanocomposite includes the following steps: mixing a whey protein solution with a curcumin solution to obtain a first reaction system, performing a first reaction to obtain a whey protein-curcumin composite; then adding a chitosan solution to obtain a second reaction system, performing a second reaction to obtain the whey protein-curcumin-chitosan ternary nanocomposite (abbreviated as WPI-Cur-CS); The whey protein in the first reaction system has a concentration of 0.025% to 0.175% (w / v), the curcumin in the first reaction system has a concentration of 0.02% to 0.07% (w / v), and the chitosan in the second reaction system has a concentration of 0.02% to 0.07% (w / v).

[0010] In some embodiments of the present invention, the whey protein is selected from at least one of whey protein isolate and whey protein concentrate.

[0011] In some embodiments of the present invention, the concentration of whey protein in the first reaction system is preferably 0.125% to 0.15% (w / v), more preferably 0.125% (w / v).

[0012] In some embodiments of the present invention, the concentration of curcumin in the first reaction system is preferably 0.02% to 0.05% (w / v), more preferably 0.03% (w / v).

[0013] In some embodiments of the present invention, the concentration of chitosan in the second reaction system is preferably 0.02% to 0.04% (w / v), more preferably 0.04% (w / v).

[0014] In some embodiments of the present invention, the first and second reactions are carried out under conditions of pH 5.0 to 7.5.

[0015] In some embodiments of the present invention, the reaction temperatures of the first reaction and the second reaction are independently between 20°C and 75°C, and / or the reaction times are independently between 0.25 h and 5 h.

[0016] In some embodiments of the present invention, after the second reaction is completed, the steps of ice-water bath, centrifugation, and collection of supernatant are further included in sequence.

[0017] In some embodiments of the present invention, the ice-water bath time is 1 to 10 minutes.

[0018] In some embodiments of the present invention, the centrifugation temperature is 4~25 °C.

[0019] In some embodiments of the present invention, the centrifugation speed is 6000~8000 g.

[0020] In some embodiments of the present invention, the centrifugation time is 2 to 40 minutes.

[0021] A whey protein-curcumin-chitosan ternary nanocomposite was prepared by the above-described preparation method.

[0022] Applications of the above whey protein-curcumin-chitosan ternary nanocomposite in drug delivery carriers, health products, or functional foods.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses whey protein and cationic polysaccharide chitosan as carrier materials and curcumin as active ingredient. Through the hydrophobic interaction and hydrogen bond between whey protein and curcumin, and the electrostatic interaction between chitosan and whey protein, a nanocomposite with a core-shell structure is synthesized in one step. This method is time-saving, simple to operate, does not require organic crosslinking agents, and has the characteristics of being green, safe and efficient. (2) The whey protein-curcumin-chitosan ternary nanocomposite prepared in this invention has a high encapsulation rate of curcumin, uniform particle size, and good colloidal stability. The chitosan shell gives the composite excellent digestive stability. In simulated gastric juice, it can weaken the enzymatic hydrolysis of protein carrier by pepsin by means of steric hindrance, delay protein degradation. After entering the intestine, the shell densifies and delays the degradation of whey protein core by trypsin, thereby achieving the intestinal slow release of curcumin and significantly improving the bioaccessibility of curcumin. (3) The whey protein-curcumin-chitosan ternary nanocomposite prepared by the present invention can be applied to drug delivery carriers, health products or functional foods, etc., further broadening the application scope of curcumin and improving its application value. Attached Figure Description

[0024] Figure 1The hydration kinetic diameter D of whey protein-curcumin-chitosan ternary nanocomposites prepared at different whey protein mass fractions H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 2 The hydration kinetic diameter D of whey protein-curcumin-chitosan ternary nanocomposites prepared at different curcumin mass fractions H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 3 The hydration kinetic diameter D of whey protein-curcumin-chitosan ternary nanocomposites prepared with different chitosan mass fractions. H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 4 The hydration kinetic diameter D of whey protein-curcumin-chitosan ternary nanocomposites prepared under different pH conditions H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 5 The hydration kinetic diameter D of whey protein-curcumin-chitosan ternary nanocomposites prepared at different reaction temperatures. H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 6 The hydration kinetics diameter D of the whey protein-curcumin-chitosan ternary nanocomposite was determined by heating at different temperatures for 30 min. H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 7 The hydration kinetics diameter D of the whey protein-curcumin-chitosan ternary nanocomposite was determined by heating at different temperatures for 60 min. H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), ultraviolet-visible absorption spectrum (E) and turbidity (F); Figure 8 The hydration kinetic diameter D of the whey protein-curcumin-chitosan ternary nanocomposite under different UV lamp irradiation times. H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), and ultraviolet-visible absorption spectrum (E); Figure 9 The hydration kinetics diameter D of the whey protein-curcumin-chitosan ternary nanocomposite under different storage conditions. H Total light intensity (A), polydispersity index (PDI) and zeta potential (B), fluorescence emission spectrum (C), fluorescence intensity value (D), and ultraviolet-visible absorption spectrum (E); Figure 10 The hydration kinetic diameter D of whey protein-curcumin-chitosan complex and soybean protein-curcumin-chitosan complex. H Total light intensity (A), polydispersity index (PDI), and zeta potential (B). Detailed Implementation

[0025] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. To make the objectives and technical solutions of the present invention clearer, the present invention will be further described in detail below using whey protein isolate, curcumin, and chitosan as raw materials, and preparing an edible ternary nanocomposite based on whey protein-chitosan synergistic stabilization of curcumin under one-step self-assembly conditions. The raw materials and equipment used in the present invention are all commonly used in the art. It should be understood that the embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0026] Unless otherwise specified, all raw materials used in this invention are commercially available.

[0027] Example 1: A whey protein-curcumin-chitosan ternary nanocomposite and its one-step self-assembly preparation method: Different mass fractions of whey protein concentrate (0.025%, 0.05%, 0.075%, 0.1%, 0.125%, 0.15%, and 0.175% (w / v) in the reaction system) were dissolved in ultrapure water at pH 7.0. Curcumin solution (0.05% (w / v) in the reaction system) was added, mixed, and reacted with magnetic stirring at 25°C for 1.5 h. Chitosan solution (0.05% (w / v) in the reaction system) was added, mixed, and reacted with magnetic stirring at 25°C for 1.5 h. The mixture was cooled in an ice-water bath for 2 min and centrifuged at 25°C and 6790 g for 10 min to obtain a whey protein-curcumin-chitosan ternary nanocomposite (supernatant).

[0028] The hydration kinetic diameter D of the obtained whey protein-curcumin-chitosan ternary nanocomposite was determined. H Light intensity, Zeta potential, polydispersity index (PDI), turbidity, fluorescence spectrum, and UV-Vis absorption spectrum were measured. The results are as follows: Figure 1 As shown, when the mass fraction of whey protein (WPI) is 0.125%, the D of the whey protein-curcumin-chitosan ternary nanocomposite is... H Small size, large number of particles, concentrated particle size distribution, and high electrostatic stability.

[0029] Example 2: A whey protein-curcumin-chitosan ternary nanocomposite and its one-step self-assembly preparation method: The only difference between this embodiment and Example 1 is that the whey protein concentrate mass fraction is controlled at 0.125%, and the curcumin mass fraction is changed to 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, and 0.07% to prepare a whey protein-curcumin-chitosan ternary nanocomposite.

[0030] The hydration kinetic diameter D of the obtained whey protein-curcumin-chitosan ternary nanocomposite was determined. H Light intensity, Zeta potential, polydispersity index (PDI), turbidity, fluorescence spectrum, and UV-Vis absorption spectrum were measured. The results are as follows: Figure 3 As shown, when the mass fraction of curcumin is 0.03%, the D of the whey protein-curcumin-chitosan ternary nanocomposite is... H Smaller size, large number of particles, concentrated particle size distribution, and high electrostatic stability.

[0031] Example 3: A whey protein-curcumin-chitosan ternary nanocomposite and its one-step self-assembly preparation method: The only difference between this embodiment and Example 1 is that the whey protein concentrate mass fraction is controlled at 0.125%, the curcumin mass fraction is 0.03%, and the chitosan mass fraction is changed to 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, and 0.07% respectively to prepare a whey protein-curcumin-chitosan ternary nanocomposite.

[0032] The hydration kinetic diameter D of the obtained whey protein-curcumin-chitosan ternary nanocomposite was determined. H Light intensity, Zeta potential, polydispersity index (PDI), turbidity, fluorescence spectrum, and UV-Vis absorption spectrum, such as Figure 3 As shown, when the chitosan mass fraction is 0.04%, the D of the whey protein-curcumin-chitosan ternary nanocomposite is... H It has smaller particle size, a larger number of particles, a concentrated particle size distribution, and high stability.

[0033] Example 4: A whey protein-curcumin-chitosan ternary nanocomposite and its one-step self-assembly preparation method: The only difference between this embodiment and Example 1 is that the whey protein concentrate mass fraction is controlled at 0.125%, the curcumin mass fraction at 0.03%, and the chitosan mass fraction at 0.04%, and the whey protein concentrate is dissolved in PBS buffer with pH values ​​of 5.0, 5.5, 6.0, 6.5, 7.0, and 7.5 to prepare a whey protein-curcumin-chitosan ternary nanocomposite.

[0034] The hydration kinetic diameter D of the obtained whey protein-curcumin-chitosan ternary nanocomposite was determined. H Light intensity, Zeta potential, polydispersity index (PDI), turbidity, fluorescence spectrum, and UV-Vis absorption spectrum, such as Figure 4 As shown, when the pH of the reaction system is 6.5, the D of the whey protein-curcumin-chitosan ternary nanocomposite is... H Small size, large number of particles, concentrated particle size distribution, and high electrostatic stability.

[0035] Example 5: A whey protein-curcumin-chitosan ternary nanocomposite and its one-step self-assembly preparation method: The only difference between this embodiment and Example 4 is that the whey protein concentrate mass fraction is controlled at 0.125%, the curcumin mass fraction at 0.03%, the chitosan mass fraction at 0.04%, the pH of the reaction system is 6.5, and the reaction temperature is changed to 25, 35, 45, 55, 65, and 75°C to prepare a whey protein-curcumin-chitosan ternary nanocomposite.

[0036] The hydration kinetic diameter D of the obtained whey protein-curcumin-chitosan ternary nanocomposite was determined. H Light intensity, Zeta potential, polydispersity index (PDI), turbidity, fluorescence spectrum, and UV-Vis absorption spectrum, such as Figure 5 As shown, when the reaction temperature is 55 °C, the D of the whey protein-curcumin-chitosan ternary nanocomposite... H It has the smallest particle size distribution and the most concentrated particle size distribution, resulting in high electrostatic stability.

[0037] Specifically, by controlling the whey protein concentrate concentration at 0.125%, the curcumin concentration at 0.03%, the chitosan concentration at 0.04%, the pH of the reaction system at 6.5, and the reaction temperature at 55 ℃, a whey protein-curcumin-chitosan ternary nanocomposite was prepared. H The wavelength was 141.0 ± 2.1 nm, the light intensity was 20.6 kcps, the PDI was 0.2, the Zeta potential was -10.8 mV, and the particles were stably dispersed.

[0038] Stability analysis: A whey protein-curcumin-chitosan ternary nanocomposite was prepared by controlling the whey protein concentration at 0.125%, the curcumin concentration at 0.03%, the chitosan concentration at 0.04%, the pH of the reaction system at 6.5, and the reaction temperature at 55 ℃. Its thermal stability was investigated by heating in a water bath at 30, 60, and 90 ℃ for 30 and 60 min, respectively. Its photostability was investigated by irradiating it under ultraviolet light for 0, 30, 60, 90, 120, 150, 180, 210, and 240 min, respectively. Its storage stability was investigated by storing it in tin foil at 25 ℃ in the dark for 0, 7, 14, 21, 28, 60, 90, 120, 150, and 180 days.

[0039] Thermal stability analysis results are as follows Figure 6 (30min) Figure 7 As shown in (60 min), the hydration kinetic diameter D of the whey protein-curcumin-chitosan ternary nanocomposite was determined by heating at 30–90 °C for 30–60 min. H There were no significant differences in colloidal chemical properties such as light intensity, polydispersity index (PDI), and zeta potential, indicating that it has high thermal stability.

[0040] The results of the light stability analysis are as follows: Figure 8 As shown, the hydration kinetics diameter D of the whey protein-curcumin-chitosan ternary nanocomposite under ultraviolet light irradiation for 0–240 min ranged from 0 to 240 min. H There were no significant differences in colloidal chemical properties such as light intensity, polydispersity index (PDI), and zeta potential, indicating that it has photothermal stability.

[0041] Storage stability analysis results are as follows Figure 9 As shown, after 120 days of storage in the dark at 25℃, the colloidal chemical properties of the whey protein-curcumin-chitosan ternary nanocomposite showed no significant difference, indicating that it has high stability within 120 days.

[0042] Comparative Example 1 A soybean protein-curcumin-chitosan ternary nanocomposite and its one-step self-assembly preparation method: The only difference between this embodiment and Example 1 is that the whey protein concentrate is replaced with soy protein isolate with a mass fraction of 0.125%, the curcumin mass concentration is 0.03%, the chitosan mass concentration is 0.04%, the pH of the reaction system is 6.5, and the reaction temperature is 55 °C, to prepare a soy protein-curcumin-chitosan ternary nanocomposite (abbreviated as SPI-Cur-CS).

[0043] The hydration kinetic diameter D of the obtained soybean protein-curcumin-chitosan ternary nanocomposite (SPI-Cur-CS) was determined. H The light intensity, zeta potential, and polydispersity index (PDI) were compared with the corresponding properties of the whey protein-curcumin-chitosan ternary nanocomposite (WPI-Cur-CS) obtained at a reaction temperature of 55℃ in Example 5. The results are as follows: Figure 10 As shown in the figure. The figure indicates that the D... H The significant increase in light intensity and the significant decrease in total light intensity indicate that the particles have aggregated, the number of particles has decreased, and the stability is poor.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this application specification, they can still modify or make equivalent substitutions to the specific implementation of the present invention, but these modifications or changes do not depart from the protection scope of the pending claims of the present invention.

Claims

1. A method for preparing a whey protein-curcumin-chitosan ternary nanocomposite, characterized in that, Includes the following steps: A whey protein solution and a curcumin solution were mixed to obtain a first reaction system, and a first reaction was carried out to obtain a whey protein-curcumin complex; then a chitosan solution was added to obtain a second reaction system, and a second reaction was carried out to obtain the whey protein-curcumin-chitosan ternary nanocomposite. The whey protein in the first reaction system has a concentration of 0.025% to 0.175% (w / v), the curcumin in the first reaction system has a concentration of 0.02% to 0.07% (w / v), and the chitosan in the second reaction system has a concentration of 0.02% to 0.07% (w / v).

2. The preparation method according to claim 1, characterized in that, The whey protein is selected from at least one of whey protein isolate and whey protein concentrate.

3. The preparation method according to claim 1, characterized in that, The concentration of whey protein in the first reaction system is 0.125%~0.15% (w / v); And / or, the concentration of curcumin in the first reaction system is 0.02%~0.05% (w / v).

4. The preparation method according to claim 1, characterized in that, The concentration of chitosan in the second reaction system is 0.02%~0.04% (w / v).

5. The preparation method according to claim 1, characterized in that, The first and second reactions were carried out under conditions of pH 5.0 to 7.

5.

6. The preparation method according to claim 1, characterized in that, The reaction temperatures of the first reaction and the second reaction are independently between 20°C and 75°C, and / or the reaction times are independently between 0.25 h and 5 h.

7. The preparation method according to claim 1, characterized in that, After the second reaction is completed, the process includes the steps of ice-water bath, centrifugation, and collection of supernatant.

8. The preparation method according to claim 7, characterized in that, The ice-water bath time is 1-10 min; and / or the centrifugation temperature is 4-25 ℃; and / or the centrifugation speed is 6000-8000 g; and / or the centrifugation time is 2-40 min.

9. A whey protein-curcumin-chitosan ternary nanocomposite, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

10. The use of the whey protein-curcumin-chitosan ternary nanocomposite according to claim 9 in drug delivery carriers, health products or functional foods.

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