High-stability curcumin microcapsule and preparation method thereof

Abstract

The application discloses a curcumin microcapsule, and a preparation method thereof. The curcumin microcapsule comprises the following components in a certain proportion: curcumin 1.1wt%-3.8wt%, glycerin monostearate 52wt%-57wt%, soybean lecithin 5wt%-10wt%, soybean protein isolate 27wt%-35wt%, and flaxseed gum 1.5wt%-5.82wt%. The glycerin monostearate and the soybean lecithin form the core material of the curcumin microcapsule, and the soybean protein isolate and the flaxseed gum form the wall material of the curcumin microcapsule. The preparation method of the curcumin microcapsule is simple and feasible, and no organic solvent is needed in the preparation process, so that no solvent residue exists. The raw materials are cheap and easy to obtain, and the whole method is highly feasible. The prepared curcumin microcapsule has high curcumin loading, slow release and excellent oxidation stability, is beneficial to the absorption of curcumin in the small intestine of human body, improves the bioavailability, and prolongs the shelf life of the curcumin microcapsule.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of medical and health care, and particularly relates to a curcumin microcapsule with high stability and a preparation method thereof. BACKGROUND

[0002] Curcumin, a polyphenolic compound extracted from natural product turmeric, has anti-inflammatory, antioxidant, antibacterial, antiviral, anticancer and other biological activities, and is a compound integrating medical treatment and nutrition and health care. Curcumin has great application potential in many fields such as medicine and food. In recent years, curcumin as a nutritional supplement has attracted more and more attention. At present, a large number of curcumin related products have appeared on the market, including powder capsules, concentrated liquids and tablets. However, the low water solubility, chemical stability and bioavailability of curcumin limit its application in the food industry.

[0003] Microcapsule is a kind of embedding technology, through which liquid droplets or solid particles are packaged into a continuous shell, and the shell is composed of protective packaging materials, which is used to protect the internal substances from the influence of external environmental factors. In the food industry, microcapsules are mainly used for the encapsulation of volatile substances and environmentally sensitive substances, and the selection of wall materials, core materials and preparation methods plays a crucial role in the stability and release characteristics of microcapsules.

[0004] The layer-by-layer self-assembly method is a very promising method for preparing microcapsules, which can accurately control the size, shape, composition, thickness and structure of microcapsules. The layer-by-layer self-assembly method refers to the method of alternately depositing oppositely charged wall materials on a charged template to form polyelectrolyte microcapsules. In recent years, more and more researchers have used microemulsion as a template, which has small particle size, uniform size and mild preparation conditions.

[0005] However, the traditional microcapsule with microemulsion as a template generally uses liquid oil as the core material, and has poor protection and release control ability for active substances. The release of active substances is usually controlled by the selection of wall materials, and a large amount of wall materials or additional fillers are often needed to maintain the solid form of the microcapsule, and the loading capacity of active substances is low. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a curcumin microcapsule with high stability and a preparation method thereof. The curcumin microcapsule provided by the present application has excellent oxidation stability, which prolongs the storage period of the curcumin microcapsule. The curcumin microcapsule provided by the present application also has obvious sustained release behavior, which is beneficial to the absorption of curcumin in the small intestine of human body and improves the bioavailability.

[0007] The technical scheme of the present application is as follows:

[0008] The application discloses a high-stability curcumin microcapsule, and components and contents of the curcumin microcapsule are as follows: 1.1wt%-3.8wt% of curcumin, 52wt%-57wt% of glyceryl monostearate, 5wt%-10wt% of soybean lecithin, 27wt%-35wt% of soybean protein isolate and 1.5wt%-5.82wt% of flaxseed gum; wherein the glyceryl monostearate and the soybean lecithin form core materials of the curcumin microcapsule, and the soybean protein isolate and the flaxseed gum form wall materials of the curcumin microcapsule.

[0009] The core materials of the microcapsule are composed of the glyceryl monostearate and the soybean lecithin in a certain proportion, and the core materials are in a solid state at room temperature, so that the contact between the curcumin and the external environment is reduced, and the oxidation stability is better; the soybean protein isolate and the flaxseed gum are in a certain proportion, so that the electrostatic adsorption effect is enhanced, and the wall materials are formed by adopting a layer-by-layer self-assembly principle, thereby increasing the stability.

[0010] The application further provides a preparation method of the curcumin microcapsule, and steps are as follows:

[0011] S1: glyceryl monostearate is melted into a liquid, and then the soybean lecithin is added and stirred until completely dissolved, so as to obtain a mixture A;

[0012] S2: curcumin is added into the mixture A obtained in the step S1 and stirred until completely dissolved, so as to obtain an oil phase;

[0013] S3: the soybean protein isolate is dispersed in water and uniformly dispersed, and then added into the oil phase obtained in the step S2 and continuously stirred, and then the pH value is immediately adjusted to 3.0-4.0, so as to obtain a curcumin primary emulsion;

[0014] S4: the flaxseed gum is stirred and dissolved in water, and the pH value is adjusted to 3.0-4.0, so as to obtain a flaxseed gum solution;

[0015] S5: the flaxseed gum solution obtained in the step S4 is added into the curcumin primary emulsion obtained in the step S3 and stirred, so as to obtain a curcumin multi-layer emulsion;

[0016] S6: the curcumin multi-layer emulsion obtained in the step S5 is freeze-dried, so as to obtain the curcumin microcapsule.

[0017] Preferably, the mass of the glyceryl monostearate and the soybean lecithin in the step S1 is composed of 6:1-9:1.

[0018] It is found through experiments that the dissolution capacity of curcumin is strong in the range.

[0019] Preferably, the mass of the curcumin and the mixture A (glyceryl monostearate and soybean lecithin) in the step S2 is composed of 1:15-1:50.

[0020] Preferably, the mass ratio of the mixture A (glyceryl monostearate and soy lecithin) and soy protein isolate in the oil phase in the step S3 is 1:0.42-1:0.6.

[0021] In the ratio range, the soy protein isolate can sufficiently emulsify the solid oil, and the curcumin primary emulsion has good stability.

[0022] Preferably, the mass ratio of the soy protein isolate and the flaxseed gum in the curcumin primary emulsion in the step S5 is 1:0.05-1:0.2.

[0023] In the ratio range, the electrostatic adsorption is strong, and the curcumin multi-layer emulsion has good stability.

[0024] Preferably, in the steps S1 and S2, the dissolving temperature is 65-75 DEG C, in the steps S3 and S4, the stirring temperature is 65-75 DEG C, and in the step S1, the melting temperature is 65-75 DEG C.

[0025] Preferably, in the step S3, the mass ratio of the soy protein isolate and water is 1:10, the stirring speed is 4000-8000 rpm, and the stirring time is 10-30 min; in the step S4, the mass ratio of the flaxseed gum and water is 1:100; and in the step S5, the stirring speed is 4000-8000 rpm, and the stirring time is 10-30 min.

[0026] Preferably, in the steps S3 and S4, 1 mol / L HCl solution is selected to adjust the pH value.

[0027] Preferably, in the step S6, the freeze-drying temperature is -80 DEG C, and the freeze-drying time is 48 hours.

[0028] Beneficial effects:

[0029] (1) The method for preparing the curcumin microcapsule is simple and easy to implement, no organic solvent is used in the preparation process, no solvent residue is left, the raw materials are cheap and easy to obtain, and the overall feasibility is high.

[0030] (2) The curcumin microcapsule has the curcumin encapsulated in the solid core material, reduces the contact between the curcumin and the external environment, has excellent oxidation stability, and prolongs the storage period of the curcumin microcapsule.

[0031] (3) The curcumin microcapsule provided by the application uses all powdery raw materials, has good formability after freeze-drying, and has a high curcumin loading capacity. For details, refer to Preparation and characterization of curcumin-loaded debranched starch / Mesona chinensis polysaccharide microcapsules: Loading levels and in vitro release published in the Food Hydrocolloids journal in 2023. The curcumin loading capacity in the article is 5.38 mg / g, which is converted into a percentage of 0.538%, far less than the curcumin loading capacity of the present application.

[0032] (4) The curcumin microcapsule provided by the application uses glyceryl monostearate and soy lecithin in a certain proportion to form a solid core material, and the crystal form of the core material is a disordered mixed crystal structure, which can improve the solubility of the solid core material to curcumin, increase the loading capacity of curcumin, and also reduce the leakage of curcumin during storage.

[0033] (5) The curcumin microcapsule provided by the application uses soy protein isolate and flaxseed gum in a certain proportion as a composite wall material, uses the principle of electrostatic self-assembly to improve the emulsifying capacity and stability of the wall material, further reduces the contact between curcumin in the core material and the external environment, and improves the chemical stability of the curcumin microcapsule.

[0034] (6) The curcumin microcapsule provided by the application uses a solid core material and a composite wall material to increase the difficulty of curcumin dissolution into gastrointestinal juice during the release process. By controlling the ratio of the solid core material and the wall material, the release of curcumin can be adjusted to achieve a sustained-release effect and improve the bioavailability.

[0035] (7) The curcumin microcapsule provided by the application can be uniformly dissolved and dispersed in an aqueous medium, has high safety, and is suitable for use in the fields of medicine, food, etc. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 DSC temperature rise curve diagram of a single solid lipid;

[0037] Figure 2 DSC temperature rise curve diagram of glyceryl monostearate of the present application;

[0038] Figure 3 Scanning electron microscope photograph of the microcapsule of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme of the present application is described clearly and completely below through embodiments. Example 1

[0040] Preparation of curcumin microcapsules:

[0041] S1 15 parts of glyceryl monostearate were weighed and melted into a transparent liquid at 70°C, then 2 parts of soybean lecithin were added and stirred until completely dissolved, to obtain mixture A;

[0042] S2 1 part of curcumin was added to mixture A, and stirred at 70°C until completely dissolved, to obtain an oil phase;

[0043] S3 8 parts of soybean protein isolate were weighed and dispersed in 80 parts of deionized water at 70°C, and then quickly added to the oil phase, and stirred at 5000 rpm for 15 min, and immediately adjusted to pH 3.5 with 1 mol / L HCl solution, to obtain a curcumin primary emulsion;

[0044] S4 0.4 parts of flaxseed gum were weighed and dissolved in 40 parts of deionized water at 70°C, and adjusted to pH 3.5 with 1 mol / L HCl solution, to obtain a flaxseed gum solution;

[0045] S5 The flaxseed gum solution was added to the curcumin primary emulsion, and stirred at 5000 rpm for 15 min, to obtain a curcumin multi-layer emulsion;

[0046] S6 The curcumin multi-layer emulsion was freeze-dried in a freeze dryer at -80°C for 48 hours, to obtain curcumin microcapsules.

[0047] Example 2

[0048] Preparation of curcumin microcapsules:

[0049] S1 60 parts of glyceryl monostearate were weighed and melted into a transparent liquid at 70°C, then 10 parts of soybean lecithin were added and stirred until completely dissolved, to obtain mixture A;

[0050] S2 1.5 parts of curcumin were added to mixture A, and stirred at 70°C until completely dissolved, to obtain an oil phase;

[0051] S3 30 parts of soybean protein isolate were weighed and dispersed in 300 parts of deionized water at 70°C, and then quickly added to the oil phase, and stirred at 5000 rpm for 15 min, and immediately adjusted to pH 3.5 with 1 mol / L HCl solution, to obtain a curcumin primary emulsion;

[0052] S4 6 parts of flaxseed gum were weighed and dissolved in 600 parts of deionized water at 70 °C, and the pH value was adjusted to 3.5 with 1 mol / L HCl solution to obtain a flaxseed gum solution;

[0053] S5 The curcumin primary emulsion was obtained by adding the flaxseed gum solution to the curcumin primary emulsion and stirring at 5000 rpm for 15 min;

[0054] S6 The curcumin microcapsules were obtained by freeze-drying the curcumin multi-layer emulsion in a freeze-dryer at -80 °C for 48 hours.

[0055] The DSC temperature rising curve of the glyceryl monostearate in the curcumin microcapsules of Example 2 and the scanning electron microscope photos of the microcapsules are shown in the accompanying Figure 2 and 3 .

[0056] Compared with the DSC temperature rising curve of the single solid lipid (the accompanying Figure 1 ), it can be seen that the initial melting temperature and the melting peak value of the glyceryl monostearate in the curcumin microcapsules prepared in the present application are reduced, and the width of the melting peak is widened, indicating that the crystallinity of the glyceryl monostearate in the microcapsules is reduced, and the crystal form of the solid core material composed of the glyceryl monostearate is a disordered mixed crystal structure.

[0057] It can be seen from the electron microscope photos that the microcapsules of the present application are irregular.

[0058] Example 3

[0059] Preparation of curcumin microcapsules:

[0060] S1 90 parts of glyceryl monostearate were weighed and melted into a transparent liquid at 70 °C, and then 10 parts of soybean lecithin were added and stirred until completely dissolved to obtain a mixture A;

[0061] S2 2 parts of curcumin were added to the mixture A, and stirred at 70 °C until completely dissolved to obtain an oil phase;

[0062] S3 60 parts of soybean protein isolate were weighed and dispersed in 600 parts of deionized water at 70 °C, and after uniform dispersion, they were quickly added to the oil phase, and stirred at 5000 rpm for 15 min, and then immediately adjusted to a pH value of 3.5 with 1 mol / L HCl solution to obtain a curcumin primary emulsion;

[0063] S4 10 parts of flaxseed gum were weighed and dissolved in 1000 parts of deionized water at 70 °C, and the pH value was adjusted to 3.5 with 1 mol / L HCl solution to obtain a flaxseed gum solution;

[0064] S5 The curcumin multi-layer emulsion was obtained by adding the flaxseed gum solution to the curcumin primary emulsion and stirring at 5000 rpm for 15 min;

[0065] S6 The curcumin multi-layer emulsion is freeze-dried in a freeze dryer at -80°C for 48 hours to obtain curcumin microcapsules. Example 4

[0066] Preparation of curcumin microcapsules:

[0067] S1 57 parts of glyceryl monostearate are weighed and melted into a transparent liquid at 70°C, and then 9 parts of soybean lecithin are added and stirred until completely dissolved to obtain mixture A;

[0068] S2 2.5 parts of curcumin are added to mixture A, and stirred at 70°C until completely dissolved to obtain an oil phase;

[0069] S3 28 parts of soybean protein isolate are weighed and dispersed in 280 parts of deionized water at 70°C, and then quickly added to the oil phase, stirred at 5000 rpm for 15 min, and immediately adjusted to pH 3.5 with 1 mol / L HCl solution to obtain a curcumin primary emulsion;

[0070] S4 3.6 parts of flaxseed gum are weighed and dissolved in 360 parts of deionized water at 70°C, and the pH value is adjusted to 3.5 with 1 mol / L HCl solution to obtain a flaxseed gum solution;

[0071] S5 The flaxseed gum solution is added to the curcumin primary emulsion, and stirred at 5000 rpm for 15 min to obtain a curcumin multi-layer emulsion;

[0072] S6 The curcumin multi-layer emulsion is freeze-dried in a freeze dryer at -80°C for 48 hours to obtain curcumin microcapsules.

[0073] Comparative Example 1

[0074] Preparation of curcumin microcapsules:

[0075] S1 1.5 parts of curcumin are added to 70 parts of caprylocaproyl glyceride, and stirred at 70°C until completely dissolved to obtain an oil phase;

[0076] S2 30 parts of soybean protein isolate are weighed and dispersed in 300 parts of deionized water at 70°C, and then quickly added to the oil phase, stirred at 5000 rpm for 15 min, and immediately adjusted to pH 3.5 with 1 mol / L HCl solution to obtain a curcumin primary emulsion;

[0077] S3 6 parts of flaxseed gum are weighed and dissolved in 600 parts of deionized water at 70°C, and the pH value is adjusted to 3.5 with 1 mol / L HCl solution to obtain a flaxseed gum solution;

[0078] S4 The flaxseed gum solution was added to the curcumin primary emulsion, stirred at 5000 rpm for 15 min, and a curcumin multi-layer emulsion was obtained;

[0079] S6 The curcumin multi-layer emulsion was freeze-dried in a freeze dryer at -80°C for 48 hours, and curcumin microcapsules were obtained.

[0080] Comparative Example 2

[0081] Preparation of curcumin microcapsules:

[0082] S1 70 parts of glycerol monostearate were weighed and melted into a transparent liquid at 70°C;

[0083] S2 1.5 parts of curcumin were added to the melted glycerol monostearate, and stirred at 70°C until completely dissolved to obtain an oil phase;

[0084] S3 30 parts of soybean protein isolate were weighed and dispersed in 300 parts of deionized water at 70°C, and then quickly added to the oil phase, stirred at 5000 rpm for 15 min, and immediately adjusted to a pH of 3.5 with 1 mol / L HCl solution to obtain a curcumin primary emulsion;

[0085] S4 6 parts of flaxseed gum were weighed and dissolved in 600 parts of deionized water at 70°C, and the pH was adjusted to 3.5 with 1 mol / L HCl solution to obtain a flaxseed gum solution;

[0086] S5 The flaxseed gum solution was added to the curcumin primary emulsion, stirred at 5000 rpm for 15 min, and a curcumin multi-layer emulsion was obtained;

[0087] S6 The curcumin multi-layer emulsion was freeze-dried in a freeze dryer at -80°C for 48 hours, and curcumin microcapsules were obtained.

[0088] Comparative Example 3

[0089] Preparation of curcumin microcapsules:

[0090] S1 60 parts of glycerol monostearate were weighed and melted into a transparent liquid at 70°C, and then 10 parts of soybean lecithin were added and stirred until completely dissolved to obtain a mixture A;

[0091] S2 1.5 parts of curcumin were added to the mixture A, and stirred at 70°C until completely dissolved to obtain an oil phase;

[0092] S3 30 parts of soybean protein isolate were weighed and dispersed in 300 parts of deionized water at 70°C, and then quickly added to the oil phase, stirred at 5000 rpm for 15 min, and immediately adjusted to a pH of 3.5 with 1 mol / L HCl solution to obtain a curcumin primary emulsion;

[0093] S4 Weigh 0.8 parts of flaxseed gum and dissolve it in 80 parts of deionized water at 70 ℃. Adjust the pH value to 3.5 with 1 mol / L HCl solution to obtain flaxseed gum solution.

[0094] S5 flaxseed gum solution was added to curcumin colostrum and stirred at 5000 rpm for 15 min to obtain curcumin multilayer emulsion.

[0095] S6 curcumin multilayer emulsion was freeze-dried at -80℃ for 48 hours in a freeze dryer to obtain curcumin microcapsules.

[0096] Experimental Example 1: Oxidative Stability of Curcumin Microcapsules

[0097] Experimental materials: Curcumin microcapsules prepared in Examples 1, 2, 3, 4, Comparative Examples 1, 2, and 3.

[0098] Experimental method: The sample was placed under natural light at room temperature for four weeks. 0.5g of sample was taken each week and the curcumin content was measured. The curcumin retention rate was calculated.

[0099] Experimental results: The experimental results are shown in Table 1.

[0100] Table 1. Results of oxidative stability test of curcumin

[0101]

[0102] As shown in Table 1, the curcumin microcapsules prepared in Examples 1, 2, 3 and 4 of this invention all exhibited relatively ideal oxidative stability.

[0103] The difference between Comparative Example 1 and Example 2 is that the same amount of liquid caprylic / capric glyceride was used instead of glyceryl monostearate and soybean lecithin in Example 2. As shown in Table 1, the oxidative stability of Example 2 is higher than that of Comparative Example 1, indicating that the solid core material of this invention can reduce the contact between curcumin and the external environment, thus protecting curcumin.

[0104] The difference between Comparative Example 2 and Example 2 is that Comparative Example 2 did not use soybean lecithin. As shown in Table 1, the oxidative stability of Example 2 is higher than that of Comparative Example 2, indicating that the combination of glyceryl monostearate and soybean lecithin in a certain ratio in this invention can better dissolve curcumin, reduce the leakage of curcumin during storage (the transfer of curcumin from the core material to the wall material), and improve the oxidative stability of curcumin.

[0105] The difference between Comparative Example 3 and Example 2 is that the mass ratio of soybean protein isolate and flaxseed gum in Comparative Example 3 is not within the range defined in the present application. As can be seen from Table 1, the oxidative stability of Example 2 is higher than that of Comparative Example 3, indicating that within the range of the mass ratio of soybean protein isolate and flaxseed gum defined in the present application, the two can better perform electrostatic self-assembly, playing a role in encapsulating and stabilizing curcumin.

[0106] Test Example Two, in-vitro release of curcumin microcapsules

[0107] Test materials: curcumin microcapsules prepared in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0108] Test method: The dialysis bag method was used to investigate the release characteristics of curcumin microcapsules. 0.5 g of sample was weighed into a dialysis bag, and 5 mL of release medium was injected, and the dialysis bag was sealed with two dialysis bag clamps to control that no air bubbles appeared in the dialysis bag and that there was no leakage at the sealing position. Then the dialysis bag was placed in 200 mL of release medium. To ensure the leakage condition, the release medium was a mixed solution of deionized water and anhydrous ethanol (7:3, v / v). During the experiment, the temperature of the release medium was maintained at 37°C, and the magnetic stirring speed was 150 rpm. After the start of the experiment, samples were taken at the pre-set time points using a syringe, with each sample being 3 mL. After sampling, 3 mL of fresh release medium was added to ensure that the total amount of release medium remained unchanged. Then the absorbance value at 426 nm was detected using a UV spectrophotometer, and the concentration C (g / mL) of curcumin in the sample was calculated by substituting it into the UV standard curve formula of curcumin. Finally, the cumulative release percentage of curcumin was calculated.

[0109] Cumulative release percentage (%) = (C x 200 / 0.5) x 100

[0110] Test results: The test results are shown in Table 2.

[0111] Table 2: Test data for in-vitro release of curcumin microcapsules

[0112]

[0113] As can be seen from Table 2, the curcumin microcapsules prepared in Example 1, Example 2, Example 3 and Example 4 of the present application release faster in the first 120 min, showing a burst release phenomenon, and the release becomes slow after 120 min.

[0114] Comparing Comparative Example 1 with Example 2, the release speed of Example 2 is slower, indicating that the use of solid lipids in the present application can increase the difficulty of the release of curcumin into the medium, playing a role in regulating the release of curcumin.

[0115] Compared with Comparative Example 2 and Example 2, the release speed of Example 2 is slower, indicating that the glycerin monostearate and soybean lecithin in the present application can better dissolve curcumin and reduce the leakage (curcumin transfer from the core material to the wall material) of curcumin, thereby achieving the slow release effect.

[0116] Compared with Comparative Example 3 and Example 2, the release speed of Example 2 is slower, indicating that the soybean protein isolate and flaxseed gum in the present application can better perform electrostatic self-assembly within the mass ratio range, thereby playing a role in regulating the release of curcumin.

[0117] The in vitro release results show that the curcumin microcapsules provided by the present application have obvious slow release effect, can further control the release of curcumin, and improve the bioavailability.

[0118] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements are also within the protection scope of the present application.

Claims

1. A highly stable curcumin microcapsule, characterized in that, The components and contents of the curcumin microcapsules are as follows: curcumin 1.1wt%-3.8wt%, glyceryl monostearate 52wt%-57wt%, soy lecithin 5wt%-10wt%, soy protein isolate 27wt%-35wt%, and flaxseed gum 1.5wt%-5.82wt%; wherein glyceryl monostearate and soy lecithin constitute the core material of the curcumin microcapsules, and soy protein isolate and flaxseed gum constitute the wall material of the curcumin microcapsules; The preparation method of the curcumin microcapsules includes the following steps: S1 melts glyceryl monostearate into a liquid, then adds soybean lecithin and stirs until completely dissolved to obtain mixture A; S2. Curcumin is added to mixture A obtained in step S1 and stirred until completely dissolved to obtain the oil phase; S3. Disperse soy protein isolate in water and add it to the oil phase obtained in step S2 after it is evenly dispersed. Continue stirring and then immediately adjust the pH value to 3.0-4.0 to obtain curcumin colostrum. S4. Dissolve flaxseed gum in water by stirring, and adjust the pH value to 3.0-4.0 to obtain flaxseed gum solution; S5 Add the flaxseed gum solution obtained in step S4 to the curcumin colostrum obtained in step S3 and stir to obtain a curcumin multilayer emulsion. S6 Freeze-dry the curcumin multilayer emulsion obtained in step S5 to obtain curcumin microcapsules; In step S1, the mass ratio of glyceryl monostearate to soybean lecithin is 6:1 to 9:1; In step S2, the mass ratio of curcumin to mixture A is 1:15 - 1:50; The mass ratio of mixture A to soy protein isolate is 1:0.42 - 1:0.6; The mass ratio of soy protein isolate to flaxseed gum is 1:0.05 - 1:0.2; The dissolution temperature in steps S1 and S2 is 65-75℃, the stirring temperature in steps S3 and S4 is 65-75℃, and the melting temperature in step S1 is 65-75℃. In step S3, the mass ratio of soy protein isolate to water is 1:10, the stirring speed is 4000-8000 rpm, and the stirring time is 10-30 min; in step S4, the mass ratio of flaxseed gum to water is 1:100; in step S5, the stirring speed is 4000-8000 rpm, and the stirring time is 10-30 min.

2. The curcumin microcapsules according to claim 1, characterized in that, In steps S3 and S4, a 1 mol / L HCl solution is used to adjust the pH value.

3. The curcumin microcapsules according to claim 1, characterized in that, In step S6, the freeze-drying temperature is -80°C and the freeze-drying time is 48 hours.

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