Preparation of curcumin microcapsule powder based on pickering emulsion for intestinal targeting delivery and its preparation method and application

Abstract

The application discloses an intestinal targeted delivery curcumin microcapsule powder prepared based on a Pickering emulsion, a preparation method and application thereof, and belongs to the technical field of intestinal targeted delivery microcapsule powder. The curcumin oil solution, the whey protein isolate solution and the sodium alginate solution are prepared first, the latter two are mixed at a specific pH and temperature to obtain a composite stabilizer solution; then the curcumin oil solution is mixed with the composite stabilizer solution at a certain proportion, and a high-speed dispersion and high-pressure homogenization are performed to obtain a fine Pickering emulsion of curcumin, auxiliary materials are added for adjustment, and then spray drying is performed to obtain the curcumin microcapsule powder. The whey protein isolate-sodium alginate composite stabilizer is used to construct a stable fine Pickering emulsion system of curcumin, can effectively improve the stability of curcumin, realize precise intestinal targeted delivery, and significantly improve the bioavailability; meanwhile, the preparation process can effectively shield the bad smell of curcumin and improve the taste. The preparation process of the intestinal targeted delivery curcumin microcapsule powder is simple and easy to implement, the cost is controllable, and the process is easy to scale up, so the intestinal targeted delivery curcumin microcapsule powder can be widely applied to the fields of functional food, nutritional supplements and the like, and has significant practical value and industrialization potential.

Description

Technical Field

[0001] This invention belongs to the field of intestinal targeted delivery microcapsule technology, and mainly relates to an intestinal targeted delivery curcumin microcapsule powder prepared based on Pickering emulsion, its preparation method and application. Background Technology

[0002] With the rapid iteration of the food industry, the continuous upgrading of consumption concepts, and the steady improvement of residents' quality of life, functional foods have become the core development direction of the food industry. Consumers' demand for food has gradually shifted from basic satiety to nutritional fortification and health enhancement. Against this backdrop, functional food factors, due to their clear physiological activities and health-regulating effects, have become the core carriers for the research and development of functional foods. Among them, curcumin, a natural polyphenolic functional factor widely found in the rhizomes of turmeric (a plant in the ginger family), is known as the "golden nutrient." With its excellent anti-inflammatory, antioxidant, hypoglycemic, antiviral, and antitumor physiological activities, it has shown broad application prospects in functional foods and nutritional supplements. It has been successfully used for coloring products such as bread, biscuits, and cheese. It has also been found that beverages rich in curcumin can effectively regulate postprandial blood sugar levels.

[0003] However, curcumin is easily affected by external factors and loses its original color. Especially under outdoor sunlight, curcumin aqueous solutions are extremely unstable, undergoing degradation reactions and losing their original pharmacological effects and color. In the highly acidic environment of the stomach, curcumin is also easily decomposed and loses its physiological functions, which limits its industrial application in functional foods. Furthermore, curcumin has a strong odor and taste that is difficult to satisfy consumer demands.

[0004] Constructing efficient delivery systems is a research hotspot for addressing the aforementioned problems. Existing carriers include liposomes and nanoparticles. Pickering emulsions rely on the adsorption and self-assembly of solid particles at the oil-water interface for stability. Compared to traditional emulsions stabilized by surfactants, they offer advantages such as good stability, low biotoxicity, and excellent biocompatibility. Furthermore, the properties of the solid particles can be tuned to optimize encapsulation and release performance, making them excellent delivery carriers for functional factors. They can reduce curcumin degradation and improve water solubility, laying the foundation for enhancing bioavailability.

[0005] Constructing microcapsules based on Pickering emulsions enables secondary encapsulation, and modifying the wall material can impart intestinal targeting properties, allowing the microcapsules to pass smoothly through the gastric environment and release curcumin in response to the intestinal tract. However, current related preparation technologies suffer from problems such as insufficient interfacial membrane stability, low encapsulation efficiency, and poor targeting response sensitivity, and are mostly still in the laboratory stage, making industrialization difficult.

[0006] Spray drying is a mature, large-scale microcapsule preparation process with advantages such as ease of operation and controllable cost. Combined with Pickering emulsions, it can be industrialized. However, the high temperature, rapid dehydration, and shear force of spray drying can damage the emulsion interfacial membrane, leading to curcumin leakage and degradation, thus affecting microcapsule performance. Currently, related spray drying technologies are still imperfect, and optimizing process parameters and formulations to balance scalability and product performance is a pressing challenge. Therefore, screening and constructing Pickering emulsion stabilizers with targeted delivery capabilities is crucial for the large-scale, high-value application of curcumin. Summary of the Invention

[0007] To address the aforementioned technical shortcomings, the present invention aims to provide an intestinal-targeted curcumin microcapsule powder prepared based on Pickering emulsion, along with its preparation method and applications. This invention optimizes the preparation of fine Pickering emulsions of curcumin, adds excipients, and spray-dries the emulsion to obtain curcumin microcapsule powder with good encapsulation properties and strong intestinal-targeted delivery function. The provided preparation process effectively masks the unpleasant odor of curcumin and improves its stability, achieving targeted delivery in the intestine and enhancing its bioavailability. This process has significant potential for widespread application. Furthermore, the preparation process provided by this invention is simple and easy to implement, promoting the large-scale production of curcumin microcapsule powder and showing broad application prospects.

[0008] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0009] This invention provides a method for preparing curcumin microcapsule powder based on Pickering emulsion, the method comprising the following steps:

[0010] (1) Dissolve curcumin powder in edible oil and heat to form a uniformly dispersed curcumin oil solution;

[0011] (2) Using protein and polysaccharide as wall materials, dissolve them in water to form protein solution and polysaccharide solution respectively, adjust the pH of the two solutions, mix the protein solution and polysaccharide solution and heat and stir to obtain polysaccharide-protein complex dispersion;

[0012] (3) The polysaccharide-protein complex dispersion was mixed with curcumin oil solution to obtain curcumin-complex solution. The curcumin-complex solution was dispersed at a speed of 10000~18000 r / min to obtain crude curcumin Pickering emulsion. The crude curcumin Pickering emulsion was homogenized at a pressure of 100~600 bar to prepare fine curcumin Pickering emulsion.

[0013] (4) Stir the curcumin fine Pickering emulsion and spray dry it after stirring to prepare curcumin microcapsule powder.

[0014] Furthermore, the edible oil includes at least one of soybean oil, peanut oil, and palm oil.

[0015] Furthermore, the heating temperature is 80 °C, and the mixture is stirred until completely dissolved.

[0016] Furthermore, the polysaccharide includes at least one of sodium alginate, chitosan, and pectin; the protein includes one of whey protein isolate and egg white protein; and the mass ratio of the polysaccharide to the protein is 5~1:1~5.

[0017] Furthermore, in step (2), the pH range is 2.0 to 7.0, and the heating and stirring temperature is 30 to 80 °C.

[0018] Furthermore, when the polysaccharide-protein complex dispersion is mixed with the curcumin oil solution, the mass ratio of curcumin to polysaccharide-protein complex is 7~3:3~7; and the total solids concentration in the polysaccharide-protein complex dispersion is 1~5%.

[0019] Furthermore, the mass ratio of curcumin to the polysaccharide-protein complex is 7~3:3~7, so that the theoretical oil loading of the final spray-dried microcapsule powder reaches 30%~70%.

[0020] Furthermore, the dispersion time is 4 to 7 minutes; the homogenization is performed 1 to 5 times.

[0021] Furthermore, step (3) also includes adding excipient A to improve the emulsion quality, specifically including the following steps: mixing the polysaccharide-protein complex dispersion with curcumin oil solution to obtain a curcumin-complex solution; mixing the curcumin-complex solution with the excipient solution to obtain a mixed solution; dispersing the mixed solution at a rotation speed of 10000~18000 r / min to obtain a crude curcumin Pickering emulsion; homogenizing the crude curcumin Pickering emulsion at a pressure of 100~600 bar to prepare a fine curcumin Pickering emulsion; the excipient A includes at least one of inulin, chitosan, low-methoxyl pectin and microcrystalline cellulose powder.

[0022] Furthermore, the mass-volume concentration of the excipient A is 0.1~0.5%.

[0023] Furthermore, step (4) also includes adding excipient B to improve the quality of curcumin microcapsule powder, specifically including the following steps: adding excipient B solution to the curcumin fine Pickering emulsion, mixing and stirring, and spray drying it after stirring to prepare curcumin microcapsule powder; the excipient B includes at least one of TG enzyme powder, genipin powder, fructose and glucose.

[0024] Furthermore, the mass-volume concentration of the excipient B is 0.1~0.5%.

[0025] Furthermore, the spray drying conditions include: an inlet air temperature of 120~180 ℃ and a feed rate of 3~7 mL / min.

[0026] Furthermore, the optimized preparation method of the curcumin microcapsule powder includes: the wall material is whey protein isolate and sodium alginate in a mass ratio of 1:5, the pH is adjusted to 3.0, the mixing temperature of the wall material solution is 30 ℃, the mass ratio of curcumin to polysaccharide-protein complex is 1:1, the total solids concentration in the polysaccharide-protein complex dispersion is 3.5%, and the spray drying conditions include an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min.

[0027] The present invention also provides curcumin microcapsule powder prepared by the preparation method described above.

[0028] Furthermore, the curcumin microcapsule powder has intestinal-targeted delivery and encapsulation properties.

[0029] The present invention also provides the application of the curcumin microcapsule powder in the preparation of intestinal-targeted delivery formulations.

[0030] Compared with the prior art, the advantages and positive effects of the present invention are:

[0031] 1. This invention provides a method for preparing curcumin microcapsule powder based on Pickering emulsion. By using a protein-polysaccharide complex with intestinal-targeted delivery performance as a stabilizer for curcumin fine Pickering emulsion, this invention can efficiently encapsulate curcumin, effectively block light and gastric acid damage, avoid its degradation and loss, and improve water solubility, thus successfully breaking through the bottleneck of curcumin application in functional foods.

[0032] 2. This invention also modifies the composite wall material and adds the excipient TG enzyme to enable microcapsules to tolerate the gastric environment and precisely release drugs in the intestine, reducing gastric loss to improve intestinal absorption efficiency and bioavailability, fully exerting the physiological activity of curcumin, improving curcumin stability, achieving precise targeted delivery to the intestine, and significantly improving its bioavailability; at the same time, the preparation process provided can effectively mask the unpleasant odor of curcumin and improve its taste.

[0033] 3. This invention also optimizes the process and formulation parameter connection between spray drying and emulsion preparation, giving full play to the advantages of spray drying in terms of simplicity, low cost and scalability, providing a feasible path for the large-scale high-value application of curcumin, which has important technological breakthrough significance and industrial value. Attached Figure Description

[0034] Figure 1 The appearance of microcapsule powders prepared from different protein-polysaccharide complexes and the changes in curcumin release rate in simulated gastrointestinal fluid are shown. Among them, A is ovalbumin-pectin complex (OVA-PE), B is whey protein isolate-chitosan complex (WPI-CS), C is ovalbumin-chitosan complex (OVA-CS), and D is sodium alginate-whey protein isolate complex (SA-WPI).

[0035] Figure 2 The effect of pH on the SA-WPI complex is shown, where A represents appearance, B represents turbidity, C represents particle size, and D represents electrical potential.

[0036] Figure 3 The effect of ionic strength on the SA-WPI complex is shown, where A represents appearance, B represents turbidity, C represents particle size, and D represents potential.

[0037] Figure 4 The effect of temperature on the SA-WPI composite is shown, where A represents appearance, B represents turbidity, C represents particle size, and D represents electrical potential.

[0038] Figure 5 The effect of different mass ratios of SA and WPI on the obtained curcumin fine Pickering emulsion and corresponding microcapsule powder is shown. A represents the appearance of the curcumin fine Pickering emulsion, B represents the appearance of the microcapsule powder, C represents the microstructure of the emulsion, and D represents the release rate of the corresponding curcumin.

[0039] Figure 6 The effect of the ratio of SA to WPI on the complex is shown, where A represents the proportion of free polyelectrolytes and B represents the yield.

[0040] Figure 7 The effect of different mass ratios of SA and WPI on the composite material is shown, where A is viscoelasticity and B is shear viscosity.

[0041] Figure 8 The effect of different mass ratios of SA and WPI on the CD spectrum of their composite.

[0042] Figure 9 The effect of different mass ratios of SA and WPI on the FTIR spectra of their complex;

[0043] Figure 10Thermogravimetric analysis of the complex of SA and WPI at different mass ratios, where A is TGA and B is DTG;

[0044] Figure 11 The effect of different mass ratios of SA and WPI on the three-phase contact angle of their composite.

[0045] Figure 12 The effect of oil loading on crude pickering emulsion of curcumin is given by: A represents the emulsion microstructure, B represents the emulsion particle size, C represents the electrical potential, and D represents the viscosity.

[0046] Figure 13 The effect of total solids concentration on crude Pickering emulsion of curcumin is given by: A = emulsion microstructure, B = emulsion particle size, C = potential, and D = viscosity.

[0047] Figure 14 The effect of dispersion rotation speed on crude pickering emulsion of curcumin is shown, where A is the emulsion microstructure, B is the emulsion particle size, C is the electrical potential, and D is the viscosity.

[0048] Figure 15 The effect of dispersion time on crude Pickering emulsion of curcumin is shown, where A represents the emulsion microstructure, B represents the emulsion particle size, C represents the electrical potential, and D represents the viscosity.

[0049] Figure 16 The effect of homogenization pressure on curcumin fine Pickering emulsion is given, where A is the emulsion particle size, B is the potential, and C is the viscosity.

[0050] Figure 17 The effect of homogenization times on curcumin fine Pickering emulsions is shown, where A is the emulsion particle size, B is the electrical potential, and C is the viscosity.

[0051] Figure 18 The effect of the mass ratio of SA to WPI in the SA-WPI complex on the microstructure of the obtained curcumin microcapsule powder;

[0052] Figure 19 The image shows the FTIR spectrum of curcumin microcapsule powder.

[0053] Figure 20 The effect of the mass ratio of SA to WPI in the complex on the appearance of the resulting curcumin microcapsule powder rehydrated emulsion;

[0054] Figure 21 The stability of curcumin microencapsulated powder at 4 ℃, 30 ℃, 60 ℃ and 90 ℃ was measured.

[0055] Figure 22 The UV irradiation stability of curcumin microcapsule powder;

[0056] Figure 23To assess the storage stability of curcumin microencapsulated powder;

[0057] Figure 24 The intestinal-targeted delivery performance of curcumin microcapsule powder;

[0058] Figure 25 The effect of adding different excipients on the appearance of curcumin fine Pickering emulsion (A) and spray-dried microcapsule powder (B);

[0059] Figure 26 The effect of excipient type on curcumin release in simulated gastric and intestinal fluids from curcumin-pickering emulsions was investigated, where A represents gastric fluid and B represents small intestinal fluid.

[0060] Figure 27 The effect of excipient type on the intestinal targeted delivery performance of curcumin microcapsule powder. Detailed Implementation

[0061] To make the above-mentioned objectives, features and advantages of the present invention clearer and easier to understand, the specific embodiments of the present invention will be described in detail below with reference to the embodiments of this specification.

[0062] It should be noted that many specific details are set forth in the following description to ensure a full understanding of the present invention; however, the present invention is not limited to the embodiments described herein, and those skilled in the art can implement it in other equivalent or alternative ways without departing from the core spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0063] The mass-volume concentrations of sodium alginate (SA), whey protein isolate (WPI), ovalbumin (OVA), pectin (PE), and chitosan (CS) involved in this invention are specifically the ratio of the mass of the corresponding substance to the volume of its solution, wherein the mass is measured in g and the volume in mL.

[0064] The excipients involved in this invention are the mass-volume concentration of an excipient solution containing TG enzyme powder, genipin powder, fructose, and glucose. Specifically, it refers to the percentage of the mass of the excipients relative to the volume of the curcumin fine Pickering emulsion. The unit of mass is g, and the unit of volume is mL.

[0065] The excipients involved in this invention are chitosan, low-methoxyl pectin, or microcrystalline cellulose powder. The mass-volume concentration of the excipient solution is the ratio of the mass of the excipient to the volume of its corresponding solution, where the mass is in g and the volume is in mL.

[0066] The total solids concentration described in this invention is specifically the mass-to-volume ratio of the SA-WPI complex to its solution. The mass of the SA-WPI complex is the sum of the mass of SA and the mass of WPI. The mass of the SA-WPI complex is expressed in g, and the volume of the solution is expressed in mL.

[0067] Example 1

[0068] This embodiment provides curcumin microcapsule powder prepared with different wall materials and the determination of its properties. The specific preparation method and performance test include the following:

[0069] I. Preparation of Curcumin Microcapsule Powder

[0070] 1. Preparation of curcumin oil solution

[0071] A certain amount of curcumin powder was dissolved in soybean oil to form a curcumin oil solution with a concentration of 4.5 mg / ml. The solution was stirred at 80°C until it was completely dissolved in the oil.

[0072] 2. Preparation of Curcumin Pickering Emulsion

[0073] (1) Take a certain amount of OVA (ovalbumin) powder, WPI (whey protein isolate) powder, SA (sodium alginate) powder, PE (pectin) powder and CS (chitosan) powder and dissolve them in water to form corresponding solutions with a mass-volume concentration of 1% (w / v). Then mix them evenly at a volume ratio of 1:1 to form four different complexes: OVA-PE, WPI-CS, OVA-CS and WPI-SA complex solutions;

[0074] (2) The composites of the different types of wall materials were mixed with curcumin oil solution at a mass ratio of 2:1. After mixing, the mixture was dispersed at 12000 r / min for 5 min to obtain crude curcumin Pickering emulsion. The crude emulsion was homogenized twice under a homogenization pressure of 400 bar to obtain fine curcumin Pickering emulsion.

[0075] 3. Preparation of curcumin spray-dried microcapsule powder: The curcumin fine Pickering emulsion prepared in step 2 was spray-dried at an inlet air temperature of 160 ℃ and a feed flow rate of 5 mL / min. The microcapsule powder in the cyclone separator and collector was collected, which is the curcumin microcapsule powder.

[0076] II. Performance Testing of Microencapsulated Powder

[0077] 1. Determination of intestinal targeted delivery performance

[0078] (1) Plotting the standard curve of curcumin

[0079] Accurately weigh 10 mg of curcumin standard, dissolve it in ethanol, and dilute to 100 mL. Accurately measure 0.25 mL, 0.5 mL, 0.75 mL, 1 mL, 1.25 mL, and 1.75 mL of the above solution into 25 mL amber volumetric flasks and dilute to volume with ethanol to obtain curcumin standard solutions with concentrations of 1 μg / mL, 2 μg / mL, 3 μg / mL, 4 μg / mL, 5 μg / mL, and 6 μg / mL, respectively. Measure the absorbance of the prepared solutions at 419 nm using a UV-Vis spectrophotometer and plot a curcumin standard curve. All procedures should be performed in the dark.

[0080] (2) Evaluation of in vitro enteric delivery performance

[0081] Preparation of simulated gastric juice: Take 6 mL of concentrated hydrochloric acid and dilute to 1 L with deionized water. Adjust the pH to 1.2 and add pepsin to achieve a concentration of 32 mg / mL. Filter and set aside.

[0082] Preparation of simulated small intestinal fluid: Take 49 mL and 51 mL of 0.2 mol / L disodium hydrogen phosphate and sodium dihydrogen phosphate solutions, respectively, add appropriate amounts of CaCl2 and bile salts, stir until dissolved, and then use deionized water to make up to 1 L, so that the final concentrations of CaCl2 and bile salts are 0.2442 mg / mL and 10 mg / mL, respectively. Adjust the pH to 6.8, add trypsin to make its content reach 2.2 mg / mL, filter and set aside.

[0083] Preparation of simulated colonic fluid: Mix 81 mL of 0.2 mol / L disodium hydrogen phosphate and 19 mL of sodium dihydrogen phosphate, then bring the volume to 1 L with deionized water. Adjust the pH to 7.4, add β-mannanase to achieve a concentration of 4 mg / mL, filter, and set aside.

[0084] Release media were prepared by premixing an equal volume of ethanol with simulated gastric or intestinal fluid to generate conditions for curcumin determination. The gastrointestinal digestive environment was simulated using a dialysis bag method. 0.5 g of microcapsule powder and 6 mL of simulated gastric fluid were mixed and placed in a dialysis bag (with a molecular weight cutoff of 1 kDa). The dialysis bag was then placed in 80 mL of simulated gastric fluid release media. The mixture was shaken for 2 h at 37 ℃ and 100 r / min in a water bath. After simulated gastric digestion, 6 mL of simulated small intestinal fluid was added to the dialysis bag and transferred to 80 mL of simulated small intestinal fluid release media, followed by shaking for 4 h. After simulated small intestinal digestion, 6 mL of simulated colonic fluid was added to the dialysis bag and transferred to 80 mL of simulated colonic fluid release media. The mixture was placed in a 37 ℃ water bath for 2 h, with an equal volume of release media added as needed. Every 1 h, 3 mL of digestive fluid was collected and an equal volume of release media was added.

[0085] Centrifuge the dialysate at 5000 g for 10 min, dilute the supernatant appropriately with anhydrous ethanol, filter the supernatant through a membrane, and measure the absorbance of the dialysate at 419 nm using a UV-Vis spectrophotometer. Calculate the concentration based on the curcumin (Cur) standard curve plotted in the same release medium, and calculate the release rate using the following formula:

[0086]

[0087] Where: m 初始 The total content of Cur in powder, in g; m 释放 The value represents the mass of Cur released during digestion, expressed in grams.

[0088] The prepared curcumin microcapsule powder was subjected to visual observation and its release performance in a simulated gastrointestinal tract was determined. Figure 1 .Depend on Figure 1 It was found that curcumin microcapsule powders prepared based on curcumin fine Pickering emulsions and spray drying on different wall materials exhibited a ginger-yellow color, a loose structure, slight agglomeration, and no obvious oil leakage. Figure 1 Based on the data on curcumin release rate, from the perspective of intestinal targeted delivery, the WPI-SA complex encapsulating curcumin has higher bioavailability.

[0089] Example 2

[0090] This embodiment investigates the effect of pH changes on the SA-WPI complex dispersion, specifically including the following operations:

[0091] Eleven portions of SA and WPI solutions, each with a mass-to-volume concentration of 0.1%, were taken and their pH values ​​were adjusted to 2.0–7.0 (intervals of 0.5). After adjustment, SA and WPI solutions at the same pH were mixed at a volume ratio of 1:10 and magnetically stirred for 30 min to obtain SA-WPI complex dispersions at different pH values. Figure 2 Observe and analyze the appearance of the SA-WPI complex dispersion. Figure 2 (as shown in A) and turbidity ( Figure 2 As shown in Figure B), particle size ( Figure 2 (as shown in C) and electric potential ( Figure 2 (As shown in D).

[0092] from Figure 2 It can be concluded that the turbidity is highest and the particle size is smaller at pH 3.0, reaching 241 nm. Therefore, pH 3.0 is selected as the optimal condition.

[0093] Example 3

[0094] This embodiment investigates the effect of ionic strength on the dispersion of SA-WPI composites, specifically including the following operations:

[0095] Five portions of SA and WPI solutions, each with a mass-volume concentration of 0.1%, were taken. Different masses of NaCl powder were added to the SA and WPI solutions and dissolved thoroughly to achieve NaCl concentrations of 0 mmol / L, 25 mmol / L, 50 mmol / L, 75 mmol / L, and 100 mmol / L. After thorough dissolution, SA and WPI solutions with the same NaCl concentration were mixed at volume ratios of 1:1 and 5:1 to obtain the appearance of SA-WPI complex dispersions under different ionic strengths. Figure 3 (as shown in A) and turbidity ( Figure 3 As shown in Figure B), particle size ( Figure 3 (as shown in C) and electric potential ( Figure 3 (As shown in D).

[0096] from Figure 3 As can be seen from A and B, the turbidity of the composite solution reaches its maximum when the NaCl concentration is 0 mmol / L. Figure 3 As shown in Figure C, the particle sizes of the SA-WPI complexes with mass ratios of 5:1 and 1:1 are 659.3 nm and 729 nm, respectively, in the absence of salt ions. Figure 3 The results from the D-test show that the absolute value of the Zeta potential of the SA-WPI complex changes in the opposite direction to the salt concentration in the solution; high salt concentration leads to decreased system stability. Therefore, a salt ion concentration of 0 was chosen as the optimal reaction condition.

[0097] Example 4

[0098] This embodiment investigates the effect of water bath temperature on the SA-WPI complex solution, specifically including the following operations:

[0099] Six portions of SA and WPI solutions, each with a mass-volume concentration of 0.1%, were taken and their pH adjusted to 3.5. These solutions were then mixed at volume ratios of 5:1 and 1:1, respectively. Using a constant-temperature water bath, the SA-WPI composite dispersions prepared at different ratios were heated for 20 min at 30℃, 40℃, 50℃, 60℃, 70℃, and 80℃. The appearance of the SA-WPI composite dispersions at different temperatures was obtained. Figure 4 (A) and turbidity ( Figure 4 (B) Particle size ( Figure 4 (C) and electric potential ( Figure 4 (D).

[0100] from Figure 4 From this, we can see that at a temperature of 30 ℃, the turbidity of the SA-WPI complex dispersion ( Figure 4As shown in A and B, the particle size reaches its maximum value. Figure 4 The C value is at a decreasing level, and the potential ( Figure 4 The temperature at which SA was found to be significantly higher than other temperatures (C) indicates that SA and WPI have the strongest binding strength. Therefore, 30 °C was selected as the optimal reaction condition.

[0101] Example 5

[0102] This embodiment investigates the effect of the mass ratio of SA to WPI on the SA-WPI complex solution and microcapsule powder, specifically including the following operations:

[0103] Nine portions of 1% (v / v) SA and WPI solutions were taken separately, and their pH was adjusted to 3.5. The SA and WPI solutions were then mixed at volume ratios of 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, and 1:5. A 1% (v / w) curcumin oil solution was added, and the mixture was dispersed at 12000 r / min for 5 min using a high-speed disperser to obtain a crude curcumin Pickering emulsion. This emulsion was homogenized twice at 400 bar to obtain a fine curcumin Pickering emulsion. The emulsion was then passed through a spray dryer and spray-dried at an inlet air temperature of 160℃ and a feed rate of 5 mL / min. The microcapsule powder collected from the cyclone separator and collector was used as the research object.

[0104] Combination Figure 5 As shown, the appearance of curcumin fine Pickering emulsions prepared at different mass ratios is obtained. Figure 5 (A), the appearance of the corresponding microcapsule powder ( Figure 5 (B), microstructure of emulsion ( Figure 5 (C) and the release rate of the obtained curcumin microcapsule powder in simulated gastrointestinal fluid ( Figure 5 (D).

[0105] from Figure 5 As can be seen from Figure A, no oil leakage occurred in any of the emulsions. From... Figure 5 As shown in Figure B, the microcapsule powder is ginger-yellow in color, has a loose texture, and exhibits slight agglomeration. Figure 5 As shown in Figure C, when the mass ratio of SA to WPI is 5:1, the SA-WPI complex-stabilized emulsion droplets exhibit a tightly interwoven network structure. Compared with emulsions stabilized by complexes of other mass ratios, the emulsion with a mass ratio of 5:1 demonstrates superior emulsifying properties.

[0106] Table 1 below shows the surface oil content, oil loading, encapsulation rate, and yield of the curcumin microcapsule powder prepared above.

[0107] Table 1. Effect of SA to WPI mass ratio on surface oil content, oil loading, encapsulation efficiency, and yield of curcumin microcapsule powder.

[0108]

[0109] Table 1 shows that when the mass ratio of SA to WPI is 5:1, the prepared microcapsule powder exhibits a high yield. Table 1 also shows that the higher the proportion of sodium alginate in the wall material, the better the elasticity of the droplet surface, thus improving the encapsulation efficiency.

[0110] Example 6

[0111] The SA-WPI complex dispersions prepared by mixing SA and WPI solutions in Example 5 at volume ratios of 5:1, 1:1, and 1:5 were centrifuged at 6000 r / min for 10 min at 25 °C. The precipitate was then freeze-dried, and the yield, composition, rheological properties, protein secondary structure, FTIR, thermogravimetric analysis, and three-phase contact angle were determined.

[0112] 1. Yield and composition of SA-WPI complex.

[0113] After the interaction between SA and WPI is complete, the suspension is centrifuged at 6000 r / min for 10 min at 25 ℃, the resulting precipitate is collected, and dried in an oven at 105 ℃. After reaching constant weight, the complex is cooled to room temperature in a desiccator and weighed. The yield of the complex is calculated using the following formula:

[0114]

[0115] In the formula: W is the dry weight of the complex, g; W0 is the total weight of SA and WPI in the reaction system, g.

[0116] The composition of the complex is evaluated by the proportion of free polyelectrolytes in the supernatant after centrifugation to the total amount of the same polyelectrolytes in the system. The calculation formula is as follows:

[0117]

[0118] In the formula: C is the concentration of free polyelectrolyte, g / mL; C0 is the total concentration of the same polyelectrolyte in the system, g / mL; the determination method of free WPI is the Coomassie Brilliant Blue-G250 method.

[0119] Construction of the bovine serum albumin standard curve: Take 6 test tubes and add 0 mL, 0.2 mL, 0.4 mL, 0.6 mL, 0.8 mL, and 1.0 mL of 1000 μg / mL bovine serum albumin solution, respectively, and then add deionized water to 1 mL to obtain bovine serum albumin dilutions ranging from 0 to 1000 μg / mL. Take 0.1 mL of each dilution and add 5 mL of 100 μg / mL Coomassie Brilliant Blue G250 solution, shake well, and let stand for 2 min. Use Coomassie Brilliant Blue G250 solution as a control and measure the absorbance at 595 nm to construct the bovine serum albumin standard curve.

[0120] Determination of free WPI: Centrifuge the SA-WPI dispersion at 6000 r / min for 10 min, take the supernatant, dilute it appropriately, take 0.1 mL, add 5 mL of 100 μg / mL Coomassie Brilliant Blue G250 solution, measure the absorbance at 595 nm, and calculate the content of free WPI according to the bovine serum albumin standard curve.

[0121] Determination of free SA: Centrifuge the SA-WPI dispersion at 6000 r / min for 10 min, take the supernatant, dilute it appropriately, and take 0.1 mL. Calculate the content of free SA using the phenol-sulfuric acid method.

[0122] from Figure 6 It can be seen that when the mass ratio of SA to WPI is 5:1, the yield of the SA-WPI complex is the lowest compared to ratios of 1:1 and 1:5, and the yield gradually increases as the mass of SA decreases. Simultaneously, the proportion of free SA reaches its maximum at a mass ratio of 5:1. Specifically, when the mass ratio of SA to WPI is 5:1, the proportions of both free SA and WPI are relatively high.

[0123] 2. Rheological properties of the SA-WPI complex

[0124] After centrifuging the SA-WPI dispersion at 6000 r / min for 10 min, the precipitate was collected. The complex was placed on the sample stage of an interfacial rheometer using PP50 plates with a plate spacing of 0.2 mm. The shear viscosity of the complex was measured (shear rate set from 0.1 to 100 s⁻¹). -1 (Measure the shear viscosity curve of the composite) and frequency scanning (set the scanning range to 1~100 Hz, strain value to 0.1%, and measure the modulus change of the composite).

[0125] like Figure 7As shown in Figure A, within the frequency scanning range, the G' and G" of all emulsions increased with increasing frequency. It was clearly observed that the storage modulus (G') of the three complexes was higher than their loss modulus (G''), which revealed that the complex condensed phase exhibited elastic deformation and mainly displayed a weak gel solid state dominated by elastic behavior.

[0126] Depend on Figure 7 As shown in Figure B, the shear viscosity of all three composites decreases with increasing shear rate, exhibiting the shear-thinning characteristics of pseudoplastic fluids. The composite viscosity reaches its highest point at a SA to WPI mass ratio of 5:1, followed by ratios of 1:1 and 1:5.

[0127] 3. Protein secondary structure analysis

[0128] The WPI and SA-WPI complex dispersions were diluted with deionized water to achieve a protein concentration of 1 mg / mL for all samples. Circular dichroism (CD) spectra from 180 nm to 260 nm were recorded at 25 °C with a response time of 0.05 s and a path length of 1 mm.

[0129] like Figure 8 As shown, compared to WPI itself, the SA-WPI composite exhibits lower ellipticity values ​​at wavelengths of 190 nm, 208 nm, and 220 nm, and in the wavelength ranges of 195–198 nm and 217–218 nm. Furthermore, Figure 8 It also revealed an important piece of information: the ellipticity of the complexes with the three different mass ratios did not change significantly, which further indicates that the secondary structure of WPI changed relatively little in the complexes with different mass ratios.

[0130] 4. Fourier Transform Infrared Spectroscopy (FTIR) Analysis

[0131] The WPI, SA, and WPI-SA complex samples were lyophilized and subjected to wavenumbers of 4000–4000 cm⁻¹. -1 Infrared spectral scanning was performed within the specified range, using Smart iTR diamond ART mode, with 32 scans and a resolution of 4 cm⁻¹. -1 .

[0132] The FTIR spectrum of the SA-WPI complex is shown below. Figure 9 WPI has four characteristic absorption peaks, located at 2917 cm⁻¹. -1 1032cm -1 1509 cm -1 and 1629 cm -1These peaks correspond to the stretching vibrations of the free hydroxyl group and the CO bond, the C=O stretching vibration of amide I, and the NH bending vibration of amide II, respectively. On the other hand, SA at 3300 cm⁻¹... -1 The characteristic peak is related to the stretching vibration of -OH, while at 1601 cm⁻¹... -1 and 1526 cm -1 The characteristic peaks are attributed to the absorption bands of the carboxylic acid ester group and the carboxylic acid group, respectively, at 1025 cm⁻¹. -1 The characteristic peaks reflect the stretching vibrations of the COC bond. From... Figure 9 As can be seen, the amide band in WPI and the -COOH absorption band in SA both shifted. This experimental result indicates that electrostatic interaction occurred between -NH2 in WPI and -COOH in SA, leading to a change in the secondary structure of WPI.

[0133] 5. Thermogravimetric analysis

[0134] 3 mg of each of the lyophilized samples of WPI, SA, and SA-WPI complex were weighed and placed in ceramic crucibles. Their thermal properties were analyzed using a thermogravimetric analyzer (TGA). Nitrogen was used as the protective gas, and the heating rate was 10 °C / min, with a heating range of 30–500 °C. The DTG curves were obtained by first-order differentiation of the TGA curves.

[0135] analyze Figure 10 The TGA curves for sample A show that all samples underwent a two-stage thermal decomposition process. The first stage occurred between 25 °C and 200 °C, during which the mass loss rate of all samples except SA did not exceed 10%. The subsequent second stage, between 200 °C and 500 °C, saw a significant increase in the mass loss rate. Notably, the mass retention rate of the complex formed by SA and WPI was lower than that of SA and WPI alone.

[0136] observe Figure 10 In the DTG curves of component B, the maximum thermogravimetric rate temperatures for free WPI and SA are 306 °C and 243 °C, respectively. In contrast, the maximum thermogravimetric rate temperatures for the composite are 308 °C (corresponding to the WPI component) and 214 °C (corresponding to the SA component), with the decomposition temperature of SA shifting towards lower temperatures. This indicates that the thermal stability of the composite decreases after the interaction between WPI and SA.

[0137] 6. Measurement of three-phase contact angle

[0138] Lyophilized samples of WPI, SA, and SA-WPI complexes were compressed into smooth sheets with a thickness of 1 mm and a diameter of 10 mm. The sheets were then immersed in a square container filled with edible oil. Using a high-precision syringe, 2 μL of deionized water was gently placed on the surface of the tablets. After equilibration, the droplets were photographed at high speed using an optical contact angle meter, and the profile of the imaged droplets was simulated using the LaPlace-Young equation to obtain the three-phase contact angles.

[0139] Figure 11 The results showed that the contact angle θ of SA was 85.1°, significantly higher than that of WPI (56.0°). The contact angle reached its maximum value of 83.6° when the mass ratio of SA to WPI was 5:1, while the contact angles at ratios of 1:1 and 1:5 were 78.1° and 79.5°, respectively. Notably, the contact angle θ values ​​of all three complexes were below 90°, indicating that they all favored the formation of stable oil-in-water emulsions.

[0140] In conclusion, a 5:1 ratio of SA to WPI (by mass) for composite wall materials is the optimal choice.

[0141] Example 7

[0142] This embodiment investigates the effect of the mass ratio of SA-WPI complex to curcumin on crude curcumin Pickering emulsion, specifically including the following operations:

[0143] SA and WPI solutions with a mass-to-volume concentration of 3% (w / v) were taken separately, and the pH was adjusted to 3.0. They were then mixed thoroughly at a mass ratio of 5:1 to obtain an SA-WPI complex solution. Curcumin oil solution was added to the SA-WPI complex at mass ratios of 3:7, 3.5:6.5, 4:6, 4.5:5.5, 5:5, 5.5:4.5, 6:4, 6.5:3.5, and 7:3, respectively, to achieve theoretical oil loadings of 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, and 70% for the final spray-dried microcapsule powder. A crude pickering emulsion of curcumin was prepared by dispersion at 12000 r / min for 5 min using a high-speed disperser, and its microstructure was obtained. Figure 12 (A) Particle size ( Figure 12 (B) Potential ( Figure 12 (C) and viscosity ( Figure 12 (D).

[0144] from Figure 6 As can be seen, the particle size reaches a minimum of 2363 nm when the oil loading is 70% (i.e., the mass ratio of the SA-WPI complex to curcumin is 7:3). Therefore, 70% is selected as the oil loading.

[0145] Example 8

[0146] This embodiment investigates the effect of the total solids concentration of the SA-WPI complex solution on the crude Pickering emulsion of curcumin, specifically including the following operations:

[0147] SA and WPI solutions with mass-volume concentrations of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0% (w / v) were taken respectively, and the pH was adjusted to 3.0. Then, SA and WPI solutions of the same concentration were mixed uniformly at a volume ratio of 5:1 and allowed to react completely to obtain SA-WPI complex solutions with total solids concentrations of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0%. The SA-WPI complex was mixed with curcumin oil solution at a mass ratio of 7:3 (to achieve a theoretical oil loading of 70% for the final spray-dried microcapsule powder). The above mixture was dispersed in a high-speed disperser at 12000 r / min for 5 min to prepare a crude curcumin Pickering emulsion, and its microstructure was obtained. Figure 13 As shown in Figure A), particle size ( Figure 13 As shown in B), electric potential ( Figure 13 (as shown in C) and viscosity ( Figure 13 (As shown in D).

[0148] from Figure 13 As can be seen, when the total solids concentration is 3.5% (w / v), the viscosity of the resulting complex solution is the highest viscosity obtained by preparing curcumin fine Pickering emulsion using a homogenizer. Furthermore, its microstructure, particle size, and potential all indicate that it can be used to prepare stable curcumin fine Pickering emulsion. Therefore, 3.5% (w / v) was selected as the optimal total solids concentration.

[0149] Example 9

[0150] This embodiment investigates the effect of changes in high-speed dispersion conditions on crude pickering emulsion of curcumin, specifically including the following operations:

[0151] SA and WPI solutions with a mass-to-volume concentration of 3.5% (w / v) were taken separately, and the pH was adjusted to 3.0. They were mixed thoroughly at a mass ratio of 5:1 and allowed to react completely to obtain the SA-WPI complex. Curcumin oil solution was added to achieve an oil loading of 70%, and the mixture was dispersed at rotation speeds of 6000, 8000, 10000, 12000, 14000, 16000, 18000, 20000, and 22000 r / min for 5 min to prepare crude curcumin Pickering emulsions. The microstructure of the emulsion was obtained. Figure 14 (A) Particle size ( Figure 14 (B) Potential ( Figure 14(C) and viscosity ( Figure 14 (D).

[0152] from Figure 14 It can be seen from this that at 14000 r / min, the particle size of the emulsion ( Figure 14 When the viscosity of the emulsion reaches its minimum (B), the emulsion exhibits the most complete emulsification effect on the oil phase, and at 14000 r / min, the viscosity of the emulsion (B) is also at its minimum. Figure 14 The C) reached a relatively low 2166 mPa·s. In summary, the emulsion exhibited the best stability at 14000 r / min, therefore this condition was chosen as the benchmark for subsequent studies.

[0153] Example 10

[0154] This embodiment investigates the effect of changes in high-speed dispersion conditions on crude pickering emulsion of curcumin, specifically including the following operations:

[0155] SA and WPI solutions with a mass-to-volume concentration of 3.5% (w / v) were taken separately, and the pH was adjusted to 5.0. They were then mixed thoroughly at a mass ratio of 5:1 to obtain an SA-WPI complex. The SA-WPI complex was then mixed with a curcumin oil solution at a mass ratio of 7:3 (to achieve a theoretical oil loading of 70% for the final spray-dried microcapsule powder). The mixture was then dispersed at 14000 r / min for 1, 2, 3, 4, 5, 6, and 7 min using a high-speed disperser to prepare a crude curcumin Pickering emulsion. Its microstructure was then obtained. Figure 15 (A) Particle size ( Figure 15 (B) Potential ( Figure 15 (C) and viscosity ( Figure 15 (D).

[0156] from Figure 15 It can be seen from the data that after 6 minutes of high-speed dispersion treatment, the microstructure of the crude curcumin Pickering emulsion ( Figure 15 Particle A exhibits a more uniform particle size distribution, with the particle size significantly decreasing to 1278 nm within the range of 5 to 7 minutes. Figure 15 (B). Meanwhile, the potential of the emulsion did not fluctuate significantly during the dispersion time, ranging from -65.4 mV to -57.5 mV. Figure 15 Between (A) and (B). The emulsion viscosity reached its lowest value, 1770 mPa·s, after 6 minutes of dispersion. Figure 15 (D). In conclusion, a dispersion time of 6 minutes was chosen as the optimal condition for subsequent research.

[0157] Example 11

[0158] This embodiment investigates the effect of changes in homogenization conditions on curcumin fine Pickering emulsions, specifically including the following operations:

[0159] SA and WPI solutions with a mass-volume concentration of 3.5% (w / v) were taken separately, and the pH was adjusted to 5.0. They were then mixed evenly at a mass ratio of 5:1 and allowed to react completely to obtain the SA-WPI complex. The SA-WPI complex was then mixed with a curcumin oil solution at a mass ratio of 7:3 (to achieve a theoretical oil loading of 70% for the final spray-dried microcapsule powder). The mixture was then dispersed at 14000 r / min for 6 min using a high-speed disperser to prepare a crude curcumin Pickering emulsion. This emulsion was then homogenized twice using a high-pressure homogenizer at 0, 200, 400, 600, and 800 bar to obtain a fine curcumin Pickering emulsion. The appearance and particle size were observed. Figure 16 (A) Potential ( Figure 16 (B) and viscosity ( Figure 16 (C)

[0160] from Figure 16 As can be seen from the data, when the homogenization pressure is 600 bar, the particle size of the emulsion is 1276 nm, the absolute value of the potential is -60.3 mV, and the viscosity is 1170 mPa·s, all of which are at a relatively good level. Considering all factors, a homogenization pressure of 600 bar was selected.

[0161] Example 12

[0162] This embodiment investigates the effect of changes in homogenization conditions on curcumin fine Pickering emulsions, specifically including the following operations: SA and WPI solutions with a mass-to-volume concentration of 3.5% (w / v) were taken separately, the pH was adjusted to 5.0, and they were mixed evenly at a mass ratio of 5:1. After sufficient reaction, an SA-WPI complex was obtained. The SA-WPI complex was mixed with a curcumin oil solution at a mass ratio of 7:3 to obtain a mixture (so that the theoretical oil loading of the final spray-dried microcapsule powder reaches 70%). The above mixture was dispersed at 14000 r / min for 6 min using a high-speed disperser to prepare a crude curcumin Pickering emulsion. This emulsion was then homogenized 1, 2, 3, 4, and 5 times using a high-pressure homogenizer at 600 bar to obtain a fine curcumin Pickering emulsion, and its particle size was determined. Figure 17 (A) Potential ( Figure 17 (B) and viscosity ( Figure 17 (C)

[0163] like Figure 17As shown in Figure B, the number of homogenization cycles has no significant effect on the potential, fluctuating within the range of -60.2 mV to -55.1 mV. It is noteworthy that the emulsion viscosity reaches its minimum value of 1007 mPa·s when the number of homogenization cycles is 2. Figure 17 (C) In summary, homogeneous quadratic morphology is chosen as the optimal condition.

[0164] Example 13

[0165] SA-WPI complex with a mass ratio of SA to WPI of 5:1 and a total solids concentration of 3.5% was prepared, and then curcumin oil solution was added to achieve a theoretical oil content of 70% in the final microcapsule powder. The mixture was dispersed at 14,000 r / min for 6 min using a high-speed disperser, and then homogenized twice at 600 bar using a high-pressure homogenizer to obtain a curcumin fine Pickering emulsion, which was then spray-dried.

[0166] The inlet air temperature was set to 120, 140, 160, and 180 ℃, and the emulsion was spray-dried at a feed rate of 5 mL / min to obtain curcumin microcapsule powder prepared at different temperatures.

[0167] Table 2 below shows the data on the oil loading, surface oil content and yield of the above curcumin microcapsule powder.

[0168] Table 2. Effects of inlet air temperature on oil loading, surface oil content, and yield of curcumin microcapsule powder

[0169]

[0170] As the inlet air temperature gradually increased, the oil loading and yield of the obtained microcapsule powder showed a trend of first increasing and then decreasing, both reaching their peaks at 140 ℃, specifically 65.40% and 39.86%, respectively. Notably, the surface oil content of the microcapsule powder was lowest at 37.68% when the inlet air temperature was 140 ℃. The experimental results indicate that the encapsulation efficiency of the microcapsule powder reached its optimum at 140 ℃. Therefore, 140 ℃ was selected as the inlet air temperature benchmark for subsequent studies.

[0171] Example 14

[0172] An SA-WPI complex with a mass ratio of SA to WPI of 5:1 and a total solids concentration of 3.5% was prepared and then a curcumin oil solution was added to achieve a theoretical oil content of 70% in the final microcapsule powder. The mixture was dispersed at 14,000 r / min for 6 min using a high-speed disperser, and then homogenized twice at 600 bar using a high-pressure homogenizer to obtain a curcumin fine Pickering emulsion, which was then spray-dried.

[0173] The inlet air temperature was set to 140 ℃, and the emulsion was spray-dried at feed rates of 4, 5, 6, 7, and 8 to obtain curcumin microcapsule powders prepared at different feed rates. Table 3 below shows the data on oil loading, surface oil content, and yield of the above curcumin microcapsule powders.

[0174] Table 3 Effects of feed rate on oil loading, surface oil content and yield of curcumin microcapsule powder

[0175]

[0176] When the feed rate is 6 mL / min, the surface oil content of the microcapsule powder is significantly lower than other levels, at 14.31%, while the oil loading is significantly higher than other levels, at 40.28%, resulting in the highest final yield of 35.09%. Therefore, 6 mL / min is selected as the optimal feed rate.

[0177] Example 15

[0178] This embodiment investigates the effect of the core-to-wall ratio (mass ratio of curcumin oil solution to SA-WPI complex) on curcumin microcapsule powder.

[0179] SA-WPI complex with a mass ratio of SA to WPI of 5:1 and a total solids concentration of 3.5% was prepared by adding curcumin oil solution and mixing at core-to-wall ratios of 1:1, 2:1, 3:1, 4:1, and 5:1. The mixture was then dispersed at 14000 r / min for 6 min using a high-speed disperser to prepare a crude curcumin Pickering emulsion. This crude curcumin Pickering emulsion was homogenized twice at 600 bar using a high-pressure homogenizer to obtain a fine curcumin Pickering emulsion. The fine curcumin Pickering emulsion was spray-dried at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to obtain curcumin microcapsule powders prepared at different mass ratios. Table 4 below shows the data on oil loading, surface oil content, yield, and encapsulation efficiency of the curcumin microcapsule powders.

[0180] Table 4. Effects of core-to-wall ratio on oil loading, surface oil content, yield, and encapsulation efficiency of curcumin microcapsule powder.

[0181]

[0182] When the core-to-wall ratio is 1:1, the surface oil content of the microcapsule powder reaches its lowest value, at only 15.06%. At this core-to-wall ratio, the encapsulation efficiency of the microcapsule powder is as high as 63.7%, indicating that its encapsulation effect is most ideal. Therefore, selecting microcapsule powder with a core-to-wall ratio of 1:1 for subsequent research is a more reasonable choice.

[0183] Example 16

[0184] Complex solutions with a total solids concentration of 3.5% and SA to WPI mass ratios of 1:5, 1:1, and 5:1 were prepared and curcumin oil solution was added at a core-to-wall ratio of 1:1. The mixture was dispersed at 14000 r / min for 6 min using a high-speed disperser, and then homogenized twice at 600 bar using a high-pressure homogenizer to obtain a fine pickering emulsion of curcumin. This emulsion was then spray-dried at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to obtain curcumin microcapsule powder. A control group (WPI group) was prepared using a WPI solution with a total solids concentration of 3.5% (without SA) prepared by a conventional emulsion method.

[0185] Curcumin microcapsule powders prepared by different mass ratios of SA and WPI were subjected to determination of microstructure, FTIR, oil loading, surface oil content, encapsulation efficiency, moisture content, solubility, rehydration, dispersibility, flowability, stability (temperature, ultraviolet light, storage time) and targeted delivery performance.

[0186] 1. Microstructure of curcumin microcapsule powder

[0187] Figure 18 The differences in surface morphology of microcapsules composed of different wall materials were depicted. Microcapsules prepared by the conventional emulsion method exhibited obvious wrinkles and depressions on their surface (WPI group). In contrast, the emulsion prepared by the SA-WPI composite showed superior protective effect, with relatively mild surface depressions and wrinkles, and no hollow microcapsules were observed.

[0188] 2. FTIR spectrum of curcumin microcapsule powder

[0189] The FTIR spectrum of curcumin microcapsule powder is as follows: Figure 19 As shown. Between 3012 and 2853 cm. -1 The strong triple bands observed within the range are due to the CH stretching vibrations of the methyl and methylene groups of the lipids in the encapsulated MCT oil. (1738, 1604 cm⁻¹) -1 These are characteristic peaks of fatty acids and can be used as an indicator of lipid content in microcapsules. The WPI microcapsule powder has the strongest peak intensity, indicating a high fatty acid content. Compared with WPI microcapsule powder, microcapsules prepared from SA-WPI complexes with SA to WPI mass ratios of 5:1, 1:1, and 1:5 have even higher peak values, indicating better encapsulation of MCT oil, thereby increasing the curcumin encapsulation rate.

[0190] 3. Appearance of curcumin microcapsule powder rehydrated emulsion

[0191] Figure 20The appearance characteristics of these emulsions after rehydration are visually demonstrated. It can be seen that the curcumin microcapsule powder obtained by using WPI as an emulsifier can be uniformly dispersed in water, exhibiting a consistent pale yellow hue. However, when the mass ratio of SA-WPI is adjusted to 1:5, the prepared curcumin microcapsule powder shows obvious pale yellow insoluble particles in the rehydrated emulsion, with most of the powder deposited at the bottom of the container. This reflects the poor water dispersibility of the curcumin fine Pickering emulsion stabilized by the complex at this ratio. In contrast, when the mass ratio of SA-WPI is adjusted to 5:1 or 1:1, the corresponding curcumin microcapsule powder exhibits excellent water dispersibility.

[0192] 4. Particle size, PDI, potential and wettability of curcumin microcapsule powder rehydrated emulsion

[0193] Table 5. Effects of SA to WPI mass ratio in the complex on particle size, PDI, potential, and wettability of curcumin microcapsule rehydrated emulsion.

[0194]

[0195] Table 5 shows the dispersion properties of curcumin microcapsule powder in water, specifically including the particle size, polydispersity index (PDI), potential, and wettability of the rehydrated emulsion. Compared with the original emulsion, no significant change was observed in the particle size of the rehydrated emulsion obtained using WPI as an emulsifier, while the particle size of the SA-WPI rehydrated emulsion showed a significant increasing trend. Experimental analysis shows that the particle size of the SA-WPI complex rehydrated emulsion increased compared to the WPI rehydrated emulsion, reaching a maximum of 3946.67 nm, especially at a SA to WPI mass ratio of 1:5. This result indicates that the microcapsule powder cannot be completely dispersed in water. The PDI value is an important indicator for measuring the degree of particle dispersion in a system; a smaller value indicates a more uniform particle distribution within the system. As can be seen from the data in Table 5, the PDI value of the rehydrated emulsion increased, and the SA-WPI complex rehydrated emulsion had a higher PDI value than the WPI rehydrated emulsion, while the zeta potential remained basically stable. In the wettability study, WPI-encapsulated microcapsules exhibited the shortest wetting time, at only 61.33 s. However, the introduction of SA led to a decrease in the wettability of the microcapsules. Furthermore, with the increase of the SA to WPI mass ratio, the wetting time of the SA-WPI complex-stabilized microcapsules also increased.

[0196] 5. The flowability of curcumin microcapsule powder

[0197] Table 6. Effects of the SA to WPI mass ratio in the complex on the bulk density, tap density, Karl Fischer index, and angle of repose of curcumin microcapsule powder.

[0198]

[0199] Table 6 lists the measured values ​​of bulk density, tap density, Karl Fischer index, and angle of repose for curcumin microcapsule powders. Compared to microcapsule powders prepared from WPI emulsions, microcapsule powders based on the SA-WPI complex exhibited a lower Karl Fischer index, particularly at SA:WPI mass ratios of 5:1 and 1:1, reaching minimum values ​​of 29.11% and 25.51%, respectively. Furthermore, the spray-dried SA-WPI complex-stabilized curcumin fine Pickering emulsion exhibited a relatively large angle of repose. Notably, the angle of repose for all curcumin microcapsule powders did not exceed 50°, indicating good flowability.

[0200] 6. Stability of curcumin microcapsule powder

[0201] (1) Effect of temperature on curcumin retention rate

[0202] Curcumin microcapsule powder was treated for 30 min at temperatures of 4 ℃, 30 ℃, 60 ℃ and 90 ℃, and the curcumin retention rate was determined.

[0203] observe Figure 21 It was found that the curcumin retention rate in all microcapsules decreased with increasing storage temperature, reaching its lowest level after treatment at 90 °C. Compared to conventional emulsions, the microcapsule powder prepared using curcumin fine Pickering emulsion exhibited the highest curcumin retention rate after treatment at the same temperature. This result further indicates that the SA-WPI complex, as a wall material, helps to improve the retention rate of the core material.

[0204] (2) Effect of ultraviolet irradiation on curcumin retention rate

[0205] The microcapsule powder was irradiated under a 20 W UV lamp (25 cm distance) for 80 h, and the retention rate of curcumin in the sample was measured periodically during the period.

[0206] Figure 22 This study reflects the trend of UV irradiation's effect on the curcumin retention rate in microcapsule powder. With increasing UV irradiation duration, the curcumin retention rate in all types of emulsions showed a decreasing trend. Specifically, the change was most significant in the conventional emulsion, where the curcumin retention rate dropped sharply to 28% after 80 hours of UV irradiation. In contrast, the curcumin retention rates in fine pickering emulsions with SA to WPI mass ratios of 5:1, 1:1, and 1:5 were 63.43%, 57.03%, and 42.62%, respectively. When the SA to WPI mass ratio was set to 5:1, the emulsion exhibited a higher curcumin retention rate.

[0207] (3) Effect of storage time on curcumin retention rate

[0208] The microcapsule powder was aliquoted into opaque sealed bags and stored in a desiccator for 30 days, during which the retention rate of curcumin in the samples was measured periodically.

[0209] Figure 23 This study demonstrates the specific impact of storage time on curcumin retention in multilayer emulsions. Observing the image data, it is clear that the curcumin retention rate in all types of emulsions decreases with increasing storage time. After a 30-day storage period, the curcumin retention rate in the conventional emulsion remained at only 46.06%, while the curcumin fine-picking emulsions with SA to WPI mass ratios of 5:1, 1:1, and 1:5 showed relatively higher retention rates of 69.71%, 65.28%, and 54.02%, respectively. This result strongly demonstrates the positive effect of the above emulsion systems in improving the retention rate of the curcumin core material, especially under the condition of an SA to WPI mass ratio of 5:1, where the curcumin retention effect is most significant. Furthermore, under the same treatment environment, compared to emulsions stabilized solely by whey protein isolate, the SA-WPI interfacial layer exhibited superior performance in stabilizing emulsion droplets. Therefore, the curcumin fine pickering emulsion system prepared using this SA-WPI interface layer can more effectively maintain the curcumin retention rate during storage.

[0210] 7. Targeted delivery performance of curcumin microcapsule powder

[0211] Figure 24 This study demonstrates the release characteristics of microcapsules of SA-WPI complexes prepared at different mass ratios after spray drying in a simulated gastrointestinal environment. The simulated process included 2 hours of digestion in the stomach, 4 hours in the small intestine, and 2 hours in the colon. Data from the figures show that the release of curcumin from the four microcapsule powders continuously increased during the 2-hour gastric digestion period. Specifically, the curcumin retention rates in SA to WPI mass ratios of 5:1, 1:1, and 1:5, as well as in conventional emulsions, were 17.38%, 23.75%, 25.38%, and 53.44%, respectively. This result indicates that optimizing the preparation conditions of the microcapsules enhanced their stability in gastric juice. During the 6-hour simulated small and colonic digestion stage, the curcumin release rates of the four microcapsule powders were 53.98%, 46.21%, 48.91%, and 44.81%, respectively. From the perspective of intestinal targeted delivery, encapsulating curcumin with an SA to WPI mass ratio of 5:1 significantly improved its bioavailability.

[0212] Example 17

[0213] This embodiment provides curcumin microcapsule powders prepared by adding excipients TG enzyme powder, genipin powder, fructose, and glucose, respectively. The preparation methods of curcumin microcapsule powders corresponding to different excipients include the following steps:

[0214] A SA-WPI complex solution with a total solids concentration of 3.5% was taken. Curcumin oil solution was added to the SA-WPI complex solution at a mass ratio of 1:1 based on the mass of the SA-WPI complex and mixed. Then, the mixture was dispersed at 14000 r / min for 6 min using a high-speed disperser to obtain a crude curcumin Pickering emulsion. The emulsion was then homogenized twice at 600 bar using a high-pressure homogenizer to obtain a fine curcumin Pickering emulsion.

[0215] 1. The excipient is curcumin microcapsule powder prepared by TG enzyme.

[0216] Take 5 portions of curcumin fine Pickering emulsion, adjust the pH to 5.5, and add 0.5% (w / v) TG enzyme powder based on the volume of the curcumin fine Pickering emulsion. Stir on a magnetic stirrer for 1 h. Spray dry the curcumin fine Pickering emulsion at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to prepare curcumin microcapsule powder.

[0217] 2. The excipient is curcumin microcapsule powder prepared from genipin powder.

[0218] Five portions of curcumin fine Pickering emulsion were taken, and the pH was adjusted to 9.0. 0.5% (w / v) genipin powder was added based on the volume of the curcumin fine Pickering emulsion, and the mixture was stirred on a magnetic stirrer for 1 h. The curcumin fine Pickering emulsion was then spray-dried at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to prepare curcumin microcapsule powder.

[0219] 3. The excipient is curcumin microcapsule powder prepared from fructose and glucose.

[0220] Five portions of curcumin fine Pickering emulsion were taken, and fructose and glucose with a mass-volume concentration of 0.5% (w / v) were added to each portion, respectively, based on the volume of the curcumin fine Pickering emulsion. The mixture was magnetically stirred for 1 h to ensure complete dissolution. The curcumin fine Pickering emulsion was then spray-dried at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to prepare curcumin microcapsule powder.

[0221] Example 18

[0222] This embodiment provides curcumin microcapsule powder prepared by adding excipients inulin, chitosan, low-methoxyl pectin, and microcrystalline cellulose powder. The preparation method of curcumin microcapsule powder with different excipients includes the following steps:

[0223] 1. Preparation of excipient solutions: Take appropriate amounts of chitosan, low-methoxyl pectin or microcrystalline cellulose powder and dissolve them in deionized water to achieve a concentration of 0.5% (w / v) excipient solution. After magnetic stirring for 8 h, adjust the pH to 3.0 with 1 mol / L HCl solution to obtain different solutions.

[0224] 2. Take an appropriate amount of SA-WPI complex dispersion with a total solids concentration of 3.5%. Add curcumin oil solution to the SA-WPI complex solution at a mass ratio of 1:1 and mix. Disperse at 14000 r / min for 6 min. Then, add an equal volume of excipient solution to the SA-WPI complex dispersion and stir magnetically for 20 min to obtain a primary emulsion. Homogenize twice under high pressure at 600 bar to obtain a secondary emulsion. Spray dry the curcumin fine Pickering emulsion at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to prepare curcumin microcapsule powders with different excipients.

[0225] Example 19

[0226] This example compares the appearance of the curcumin fine Pickering emulsion prepared in Examples 17-18 with that of curcumin.

[0227] The appearance, oil loading, surface oil, encapsulation rate, yield, water content, solubility, wettability and flowability of the microcapsule powder were determined, with curcumin microcapsule powder prepared without the addition of excipients as the control group.

[0228] 1. Curcumin Pickering Emulsion ( Figure 25 (A) and its spray-dried powder ( Figure 25 Appearance of (B)

[0229] Depend on Figure 25 As shown in Figure A, the addition of chitosan resulted in the formation of a large amount of flocculent matter and solid particles in the emulsion, while low-methoxyl pectin significantly increased the emulsion's viscosity, leading to a substantial decrease in flowability and making spray drying impossible. In contrast, the addition of microcrystalline cellulose did not cause oil leakage. Although the emulsion showed stratification after standing for 24 hours, its initial stability was good and did not affect the spray drying process; the resulting microcapsule powder did not exhibit oil leakage. Figure 25 As shown in Figures A and B, the addition of TG enzyme, glucose, and fructose did not affect the stability of the emulsion and successfully achieved spray drying.

[0230] 2. Quality of Curcumin Microcapsule Powder

[0231] Table 7. Effects of different excipients on the quality of curcumin microcapsule powder

[0232]

[0233] Table 7 describes the effects of adding different excipients on the quality of curcumin microcapsule powder. When the theoretically set oil loading capacity was 50%, the actual oil loading capacity was slightly increased by adding fructose and TG enzyme to the wall material, reaching 41.07% and 41.15%, respectively. On the other hand, the microcapsule powder prepared using TG enzyme and microcrystalline cellulose as wall material components had relatively low surface oil content, specifically 11.98% and 13.17%. Further observation of the encapsulation efficiency data showed that the encapsulation efficiency of the microcapsule powder prepared using TG enzyme and microcrystalline cellulose was as high as 71.09% and 71.12%, respectively, which is significantly better than other microcapsule powder samples. The moderate increase in oil loading capacity, the effective reduction in surface oil content, and the significant increase in encapsulation efficiency all strongly demonstrate the superiority of TG enzyme and microcrystalline cellulose in the preparation of high-quality microcapsule powder. In addition, the moisture content of all microcapsule powders was less than 6%. This result indicates that the moisture was fully evaporated during the spray drying process, and the microcapsule powder reached an ideal dry state, which is beneficial for the long-term storage and market promotion of the product.

[0234] 3. Solubility and wettability of curcumin microcapsule powder

[0235] Table 8. Effects of adding different excipients on the solubility and wettability of curcumin microcapsule powder

[0236]

[0237] Table 8 presents the data demonstrating the solubility and wetting time of the microencapsulated powder. The microencapsulated powder prepared using TG enzyme as a wall material additive exhibited the highest solubility (67.47%), accompanied by the longest wetting time. In particular, the introduction of TG enzyme not only improved the powder's solubility but also prolonged its wetting time. This characteristic may provide favorable conditions for the powder's resistance to digestion in gastric juice; therefore, using it as a wall material to encapsulate curcumin in the preparation of microencapsulated powder is especially suitable.

[0238] 4. The flowability of curcumin microcapsule powder

[0239] Table 9. Effects of different excipients on the flowability of curcumin microcapsule powder

[0240]

[0241] Table 9 illustrates the effect of added excipients on the flowability of curcumin microcapsule powder. Microcapsules containing microcrystalline cellulose, glucose, fructose, and TG enzyme all exhibited Karl Fischer indexes ranging from 32% to 37%, indicating good flowability. Furthermore, the angle of repose also reflects differences in microcapsule flowability. Microcapsules containing glucose showed the smallest angle of repose at only 40.95°, a result consistent with the good flowability indicated by the Karl Fischer index; a smaller angle of repose suggests superior flowability.

[0242] 5. Intestinal-targeted delivery performance of curcumin fine Pickering emulsion

[0243] Figure 26 The study depicted the trend of curcumin release rate in different curcumin-containing Pickering emulsions in simulated gastric and intestinal fluids over digestion time. In the control group emulsion, the curcumin release rate rapidly reached 19.25% within the first hour in simulated gastric fluid, and then continued to rise over the next 5 hours, eventually reaching a maximum release rate of 53.94%. The release rate of curcumin in the stomach was optimized after the addition of glucose, microcrystalline cellulose, and TG enzyme.

[0244] Table 10. Effects of excipient type on the cumulative release rate of curcumin from Pickering emulsion in simulated gastric and small intestinal fluids.

[0245]

[0246] Table 10 reflects the effect of excipient type on the cumulative release rate of curcumin from curcumin fine pickering emulsions in simulated gastric and small intestinal fluids. After 6 hours of gastric digestion, the release rates of curcumin fine pickering emulsions supplemented with glucose, microcrystalline cellulose, and TG enzyme were 46.53%, 43.6%, and 40.90%, respectively. The results show that TG enzyme significantly improved the encapsulation efficiency and controlled release capability of curcumin in curcumin fine pickering emulsions.

[0247] 6. Intestinal-targeted delivery performance of curcumin microcapsule powder

[0248] Table 11 Effect of excipient type on the cumulative release rate of curcumin in microencapsulated powder in simulated gastric and intestinal fluids

[0249]

[0250] Table 11 reflects the effect of excipient type on the cumulative release rate of curcumin in microencapsulated powder in simulated gastric and intestinal fluids. Figure 27This study reflects the influence of excipient type on the intestinal-targeted delivery performance of curcumin microcapsule powder. As shown in the figures, within 2 hours of gastric release, the cumulative release rate of the original control group was 17.38%. Similar to the digestibility of the emulsion, the microcapsule powder with added TG enzyme and microcrystalline cellulose exhibited significantly enhanced resistance in gastric juice, with release rates of 14.50% and 15.81%, respectively, after 2 hours of gastric digestion. Within 6 hours of intestinal digestion, the cumulative release rates of curcumin were 59.21% and 55.91%, respectively, demonstrating significantly enhanced intestinal-targeting performance.

[0251] 7. Particle size variation during the digestion of curcumin microcapsule powder

[0252] Table 12. Effects of excipient type on particle size variation of curcumin microcapsule powder during simulated gastrointestinal digestion.

[0253]

[0254] Table 12 presents the particle size evolution of different microencapsulated powders under simulated in vitro digestion conditions. Compared to the rehydrated emulsion, the particle size of the microencapsulated powders after gastrointestinal digestion showed an increasing trend. In particular, the particle size of the microencapsulated powder cross-linked with TG enzyme increased only slightly from 1959 nm to 2182 nm after 120 min of gastric digestion, indicating a significant improvement in its stability.

[0255] Example 20

[0256] Based on the optimization of the preparation method provided in the previous embodiments, this embodiment provides an optimized preparation method for curcumin microcapsule powder (curcumin oil powder), which specifically includes the following operations:

[0257] 1. Dissolve curcumin powder in edible oil and heat it to form a uniformly dispersed curcumin oil solution;

[0258] 2. Whey protein isolate and sodium alginate are used as wall materials. The mass ratio of sodium alginate to whey protein isolate is 5:1. They are dissolved in water to form whey protein isolate solution and sodium alginate solution, respectively. The pH is adjusted to 3.0. After adjustment, the whey protein isolate solution and sodium alginate solution are mixed and heated and stirred at 30°C to obtain a complex dispersion.

[0259] 3. A curcumin-complex solution is prepared by mixing the complex dispersion with a curcumin oil solution at a total mass ratio of whey protein isolate and sodium alginate to curcumin of 1:1. The curcumin-complex solution or the mixed solution is dispersed at 14000 r / min for 6 min to obtain a crude curcumin Pickering emulsion. The crude curcumin Pickering emulsion is homogenized twice at a pressure of 600 bar to prepare a fine curcumin Pickering emulsion.

[0260] 4. Add the excipient TG enzyme to the curcumin fine Pickering emulsion, with a mass-volume concentration of 0.5% based on the volume of the curcumin fine Pickering emulsion. Stir thoroughly, and after stirring, spray dry it. The spray drying operation includes spray drying at an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min to prepare curcumin microcapsule powder.

[0261] In summary, this invention provides a method for preparing curcumin intestinal-targeted microcapsule powder based on Pickering emulsion and its spray-drying process. This method involves steps such as curcumin oil solution preparation, polysaccharide-protein complex solution preparation, Pickering emulsion preparation, spray drying, and excipient addition. The process parameters for each step are clearly defined. By adding excipients such as TG enzyme, the encapsulation properties and intestinal targeting performance of the microcapsules are significantly improved. The process is controllable, suitable for large-scale promotion, and has broad application prospects.

[0262] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A method for preparing intestinal-targeted curcumin microcapsule powder based on Pickering emulsion, characterized in that, The preparation method includes the following steps: (1) Dissolve curcumin powder in edible oil and heat to form a uniformly dispersed curcumin oil solution; (2) Using protein and polysaccharide as wall materials, dissolve them in water to form protein solution and polysaccharide solution respectively, adjust the pH of the two solutions, mix the protein solution and polysaccharide solution and heat and stir to obtain polysaccharide-protein complex dispersion; (3) The polysaccharide-protein complex dispersion is mixed with the curcumin oil solution to obtain a curcumin-complex solution. The curcumin-complex solution is dispersed at a speed of 10,000 to 18,000 r / min to obtain a crude curcumin Pickering emulsion. The crude curcumin Pickering emulsion is homogenized at a pressure of 100 to 600 bar to prepare a fine curcumin Pickering emulsion. (4) Stir the curcumin fine Pickering emulsion and spray dry it after stirring to prepare curcumin microcapsule powder.

2. The preparation method according to claim 1, characterized in that, In step (2), the polysaccharide includes at least one of sodium alginate, chitosan and pectin; the protein includes one of whey protein isolate and egg white protein; the mass ratio of the polysaccharide to the protein is 5~1:1~5; and the total solids concentration in the polysaccharide-protein complex dispersion is 1~5%.

3. The preparation method according to claim 1, characterized in that, In step (2), the pH range is 2.0 to 7.0, and the heating and stirring temperature is 30 to 80 °C.

4. The preparation method according to claim 1, characterized in that, In step (3), when the polysaccharide-protein complex dispersion is mixed with the curcumin oil solution, the mass ratio of curcumin to polysaccharide-protein complex is 7~3:3~7.

5. The preparation method according to claim 1, characterized in that, Step (3) further includes adding excipient A to improve emulsion quality, specifically including the following steps: mixing a polysaccharide-protein complex dispersion with a curcumin oil solution to obtain a curcumin-complex solution; mixing the curcumin-complex solution with an excipient solution to obtain a mixed solution; dispersing the mixed solution at a rotation speed of 10000~18000 r / min to obtain a crude curcumin Pickering emulsion; homogenizing the crude curcumin Pickering emulsion at a pressure of 100~600 bar to prepare a fine curcumin Pickering emulsion; excipient A includes at least one of inulin, chitosan, low-methoxyl pectin, and microcrystalline cellulose powder.

6. The preparation method according to claim 1, characterized in that, Step (4) further includes adding excipient B to improve the quality of curcumin microcapsule powder, specifically including the following steps: adding excipient B solution to the curcumin fine Pickering emulsion, mixing and stirring, and spray drying it after stirring to prepare curcumin microcapsule powder; the excipient B includes at least one of TG enzyme powder, genipin powder, fructose and glucose.

7. The preparation method according to claim 1, characterized in that, The conditions for spray drying include: an inlet air temperature of 120~180 ℃ and a feed rate of 3~7 mL / min.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The optimized preparation method of the curcumin microcapsule powder includes: the wall material is whey protein isolate and sodium alginate in a mass ratio of 1:5, the pH is adjusted to 3.0, the mixing temperature of the wall material solution is 30 ℃, the mass ratio of curcumin to polysaccharide-protein complex is 1:1, the total solids concentration in the polysaccharide-protein complex dispersion is 3.5%, and the spray drying conditions include an inlet air temperature of 140 ℃ and a feed rate of 6 mL / min.

9. Curcumin microcapsule powder prepared by any one of the preparation methods according to claims 1 to 7.

10. The use of the curcumin microcapsule powder according to claim 9 in the preparation of intestinal-targeted delivery formulations.

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