A method for preparing an O / W / O type multi-component composite emulsion gel and its application.

Abstract

This invention belongs to the field of food science and engineering technology, specifically relating to a method for preparing an O / W / O type multi-component composite emulsion gel and its application. Using natural plant oil emulsions as a carrier, this invention employs a simple, green, and efficient method to encapsulate the fat-soluble component astaxanthin within the oil emulsion. Furthermore, water-soluble polyphenols are synergistically added to enhance system stability. The three-dimensional network structure of the oleogel further strengthens overall stability and protects the active ingredients. This successfully constructs an O / W / O type multi-component composite emulsion gel delivery system with high stability, good controlled-release performance, and a green and efficient preparation process, co-loaded with astaxanthin and proanthocyanidins. After 28 days of storage at 25°C or 5 days of UV irradiation, the astaxanthin retention rate remains above 80%. Even after 35 days of storage, the system maintains stable microstructure, providing a novel and feasible solution for the synergistic and efficient encapsulation and stable delivery of fat-soluble and water-soluble bioactive substances.

Description

Technical Field

[0001] This invention belongs to the field of food science and engineering technology, specifically relating to a method for preparing an O / W / O type multi-component composite emulsion gel, particularly a method for preparing an O / W / O type multi-component composite emulsion gel with high stability, good encapsulation efficiency, mild preparation process and suitable for large-scale production, and its application as an encapsulation system for encapsulating and delivering poorly stable fat-soluble components, photosensitive components and easily oxidized components. Background Technology

[0002] O / W / O type emulsion gel is an advanced bioactive substance delivery system that integrates multilayer structure and gel properties. This system features a unique "inner oil phase - intermediate aqueous phase - outer oleogel network" structure, enabling partitioned encapsulation and multiple protection of bioactive substances. Currently, this system has shown broad application prospects in the food, pharmaceutical, and cosmetic fields. Especially in the food industry, it can be used for the stable delivery of fat-soluble vitamins, polyphenols, and flavor substances, and has been applied to the development of 3D printed functional foods and low-fat meat products, as disclosed in patents CN119214302A, CN119700992A, CN118901811A, and CN110041459A.

[0003] The two-step emulsification-gelation method is currently the most commonly used method for preparing O / W / O type emulsion gels. Its basic process is as follows: First, the inner oil phase and aqueous phase are mixed, and an O / W primary emulsion is prepared by high-speed shearing or ultrasonic emulsification. Then, this primary emulsion is used as the dispersed phase and mixed with the outer oil phase for a second emulsification, forming an O / W / O multi-emulsion. Finally, gelation is induced by cooling, ionic crosslinking, pH adjustment, or enzymatic crosslinking to solidify the system. However, emulsion gel systems prepared by a single oil and aqueous phase have poor stability. Therefore, to further improve the stability of the emulsion system, existing technologies often employ strategies such as adding surfactants (patents CN104892716A, CN119700992A) or solid nanoparticles (patents CN110041459A, CN119279201A). However, most synthetic surfactants are potentially toxic to cells at high concentrations and are difficult to biodegrade, making them unsuitable for the food and pharmaceutical industries where biocompatibility is extremely important. Furthermore, surfactant adsorption at interfaces is a dynamic equilibrium, and desorption can easily occur during long-term storage or when subjected to environmental disturbances, leading to interfacial membrane failure. The method of preparing Pickering emulsions using solid nanoparticles also suffers from the following problems: the preparation process of functionalized nanoparticles is complex (usually involving multiple steps such as chemical modification, high-pressure homogenization, and freeze-drying), high equipment requirements, poor batch stability, and increased production costs. In addition, the dense packing of particles at the interface may affect the release rate of active ingredients.

[0004] Of course, there are also documents that disclose the strategy of mixing biological liposomes with gels, such as the one disclosed in patent US4708861A. However, since the biological liposomes disclosed therein are vesicles, and vesicles require relatively harsh conditions for preparation and preservation, otherwise the experiment is very likely to fail due to the rupture of the vesicle membrane, which undoubtedly further increases the production cost.

[0005] In summary, current technologies, whether relying on traditional surfactants, solid nanoparticles, or employing stabilization strategies based on biological vesicles, struggle to meet the comprehensive requirements of high biocompatibility, simple and low-cost processing, and controllable release of active ingredients. Therefore, developing a novel O / W / O composite emulsion gel preparation method that does not rely on synthetic surfactants or complex nanoparticles to achieve a green, stable, efficient, and controllable release behavior active ingredient delivery system has significant scientific and industrial value. Summary of the Invention

[0006] To address the technical problems of high preparation costs and complex processes caused by the poor stability of current O / W / O type emulsion gels, which require the addition of surfactants or solid nanoparticles as stabilizers during preparation, this invention proposes a method for preparing O / W / O type multi-composite emulsion gels and its application. It also provides an application of sesame oil bodies in the preparation of O / W / O type multi-composite emulsion gels.

[0007] This invention uses natural plant oil bodies as carriers and employs a simple, green, and efficient method to encapsulate poorly stable fat-soluble components within oil body emulsions. Furthermore, water-soluble polyphenols are synergistically added to enhance system stability and the encapsulation rate of fat-soluble active ingredients. The three-dimensional network structure of the oleogel further strengthens overall stability and the protection of active ingredients. This successfully constructs an O / W / O type multi-component composite emulsion gel with high stability, excellent controlled-release performance, and a green and efficient preparation process. This provides a novel and feasible solution for the synergistic and efficient encapsulation and stable delivery of fat-soluble and water-soluble bioactive substances.

[0008] The technical solution provided by this invention is as follows:

[0009] The first aspect of the present invention is to provide an application of sesame oil body in the preparation of O / W / O type multi-component composite emulsion gel, wherein the sesame oil body is obtained by the following method: sesame seeds are soaked in a NaHCO3 solution with a concentration of 0.1~0.2 mM and a pH of 9.0~10.0 to obtain a sesame solution, and then the sesame solution is crushed in a high-speed blender. The crushed slurry is filtered, centrifuged, and separated to obtain the upper sesame oil body.

[0010] Preferably, the O / W / O type multi-component emulsion gel is formed by mixing sesame oil and oil gel, dispersing at high speed, and then cooling and solidifying; the oil gel is prepared using monoglycerides and beeswax as gelling agents and vegetable oil as the oil phase, wherein the vegetable oil is selected from sunflower seed oil and corn oil.

[0011] A second aspect of the present invention is to provide a method for preparing an O / W / O type multi-component composite emulsion gel, comprising the following steps:

[0012] (1) Preparation of sesame oil body

[0013] Sesame seeds were soaked in a NaHCO3 solution with a concentration of 0.1~0.2 mM and a pH of 9.0~10.0 to obtain a sesame solution. The sesame solution was then crushed in a high-speed blender. The crushed pulp was filtered and centrifuged to separate the upper sesame oil body.

[0014] (2) Preparation of O / W / O type multi-component composite emulsion gel:

[0015] Monoglycerides and beeswax were added to sunflower seed oil, mixed, and heated and stirred until completely dissolved to obtain an oil gel.

[0016] The total mass of the monoglyceride and beeswax accounts for 5% to 8% of the mass of sunflower seed oil, and the mass ratio of the monoglyceride to beeswax is 1:1 to 3.

[0017] The sesame oil body obtained in step (1) was added dropwise to the above olegel while stirring continuously. The mass ratio of olegel to sesame oil body was 6~7:3~4. After high-speed dispersion, the mixture was immediately placed in an ice-water bath until it solidified, thus obtaining the O / W / O type multi-composite emulsion gel.

[0018] Preferably, the mass ratio of sesame seeds to NaHCO3 solution in (1) is 1:5~10.

[0019] As a further preferred embodiment, the mass ratio of sesame seeds to NaHCO3 solution in (1) is 1:6~8, and more preferably, the mass ratio of sesame seeds to NaHCO3 solution is 1:7.

[0020] Preferably, the mass of the fat-soluble component added in (2) accounts for 0.01% to 0.03% of the mass of the sesame oil body, and the mass ratio of the sesame oil body to water is 6 to 8: 2 to 4.

[0021] As a preferred option, the conditions for high-speed dispersion in (2) are: rotation speed of 5500~6500 rpm and processing time of 2~5 min.

[0022] A third aspect of the invention is the application of the composite emulsion gel, preferably wherein the composite emulsion gel is used to deliver a fat-soluble component, a photosensitive component, and an easily oxidized component, wherein the fat-soluble component is selected from any one of astaxanthin, carotene, lutein, and curcumin, and the photosensitive component is selected from any one of polyphenols, proanthocyanidins, and vitamins.

[0023] A fourth aspect of the present invention is to provide a method for preparing an O / W / O type multi-component composite emulsion gel encapsulation and delivery system co-loaded with astaxanthin and proanthocyanidins, which is prepared by the following steps:

[0024] Preparation of S1 sesame oil

[0025] Sesame seeds and NaHCO3 solution were mixed at a mass ratio of 1:6~8 to obtain a sesame solution. The concentration of NaHCO3 solution was 0.1~0.2 mM and the pH was 9.0~10.0. The sesame solution was then crushed in a high-speed blender. The crushed pulp was filtered and centrifuged to separate the upper sesame oil body.

[0026] Loading of S2 fat-soluble components

[0027] Add fat-soluble components to the sesame oil body obtained in S1, heat at 60~90℃ for 0.5~2 h, then add water to the sesame oil body, stir and mix at room temperature, adjust the pH of the system to 3.0~7.0, homogenize at 8000~12000 rpm for 2~3 min, and then adjust the pH of the system to neutral to obtain a sesame oil body emulsion loaded with fat-soluble components;

[0028] The fat-soluble component is selected from any one of astaxanthin, carotene, lutein, and curcumin;

[0029] S3 proanthocyanidin loading

[0030] Proanthocyanidins are added to the sesame oil emulsion loaded with fat-soluble components prepared in S2, and the mixture is stirred thoroughly at room temperature to obtain a sesame oil emulsion co-loaded with fat-soluble components and proanthocyanidins; the mass ratio of proanthocyanidins to fat-soluble components is 1~2:1.

[0031] Preparation of an O / W / O type multi-component composite emulsion gel delivery system co-loaded with S4 astaxanthin and proanthocyanidins

[0032] Monoglycerides and beeswax are added to sunflower seed oil, mixed, heated and stirred until completely dissolved to obtain an oil gel; the total mass of the monoglycerides and beeswax accounts for 5% to 8% of the mass of sunflower seed oil, and the mass ratio of the monoglycerides to beeswax is 1:1 to 3;

[0033] The sesame oil emulsion co-loaded with the fat-soluble component and proanthocyanidins prepared in S3 was added dropwise to the above oleogel while continuously stirring. The mass ratio of oleogel to sesame oil emulsion co-loaded with fat-soluble component and proanthocyanidins was 6~7:3~4. After high-speed dispersion, the mixture was immediately placed in an ice-water bath until solidified, thus obtaining the O / W / O type multi-composite emulsion gel delivery system co-loaded with astaxanthin and proanthocyanidins.

[0034] In the above preparation method, preferably, in step S2, the temperature is heated at 75~85℃ for 1~1.5 h, and the stirring speed at room temperature is 200~400 rpm.

[0035] Preferably, in step S2, the pH of the system is adjusted to 3.0, and homogenized at a speed of 9000~11000 rpm for 2~3 min.

[0036] The present invention has the following advantages and effects compared with the prior art:

[0037] (1) Based on the emulsion gel characteristics of plant oil bodies, especially sesame oil bodies, and the network structure characteristics of oleogels, this invention successfully constructs a highly stable O / W / O type multi-composite emulsion gel without relying on traditional emulsifier components such as amphiphilic composite emulsifiers, surfactants, and solid nanoparticles. Experimental results show that the O / W / O type multi-composite emulsion gel prepared by this invention can still maintain microstructure stability after 35 days of storage. This method not only simplifies the process steps and significantly reduces the preparation cost, but also improves the safety of the product, providing a new path for developing simple, economical, stable and efficient O / W / O type emulsion gels.

[0038] (2) By adjusting the pH and temperature conditions during the preparation of sesame oil emulsion, this invention significantly improves the encapsulation rate and storage stability of astaxanthin in the emulsion system. Experimental results show that when the pH is 3.0, the encapsulation rate is as high as 71%, which is 6.0% higher than that when the pH is 7.0 (encapsulation rate 67%), and effectively improves the stability of sesame oil emulsion with a low TSI value.

[0039] (3) This invention addresses the common application problems of astaxanthin as a fat-soluble active substance, such as low encapsulation rate, easy oxidation and degradation, and low bioavailability. By combining proanthocyanidins with the encapsulation characteristics of natural plant oils and the structural characteristics of oleogels, this invention achieves efficient encapsulation and stable protection of astaxanthin from multiple levels. In particular, the addition of proanthocyanidins improves the encapsulation rate of astaxanthin to a certain extent. The results show that after 28 days of storage at 25°C or 5 days of treatment under ultraviolet light, the astaxanthin retention rate can still reach more than 80%. At the same time, the system exhibits excellent in vitro digestion performance, so it can be used in various high-end technology fields such as functional foods, health products or pharmaceuticals. Attached Figure Description

[0040] Figure 1 This is a graph showing the effect of different pH values ​​on the encapsulation rate of astaxanthin in sesame oil emulsion in Example 1 of the present invention.

[0041] Figure 2 The TSI variation of the sesame oil emulsion prepared in Example 1 of this invention is shown.

[0042] Figure 3 These are laser confocal microscopy images and optical microscopy oil immersion images of the sesame oil emulsion prepared in Example 1 of the present invention.

[0043] Figure 4 These are confocal laser scanning microscope images and optical microscope oil immersion images of the multi-component emulsion gel prepared in Example 2 of the present invention;

[0044] Figure 5 This is a cryo-scanning electron microscope image (magnification 200x) of the multi-component emulsion gel prepared in Example 2 of the present invention.

[0045] Figure 6 This is a cryo-scanning electron microscope image (magnification 4000x) of the multi-component emulsion gel prepared in Example 2 of the present invention.

[0046] Figure 7 This is a visual diagram of the storage process of the multi-component emulsion gel prepared in Example 2 of the present invention;

[0047] Figure 8 The graph shows the photostability and storage stability of the O / W / O type multi-component composite emulsion gel encapsulation and delivery system co-loaded with astaxanthin and proanthocyanidins prepared in Example 3 of this invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the present invention will now be further described in conjunction with specific embodiments.

[0049] Example 1

[0050] This embodiment focuses on investigating the effect of pH adjustment on astaxanthin encapsulation efficiency in order to obtain the optimal pH value for astaxanthin encapsulation. This embodiment provides a sesame oil emulsion loaded with astaxanthin, and the preparation method is as follows:

[0051] Preparation of S1 sesame oil body: Sesame seeds were soaked in NaHCO3 solution (0.1 mM, pH 9.5) at a mass ratio of 1:7 at 4℃ for 18 h to obtain sesame solution. The sesame solution was then crushed and stirred in a high-speed blender for 4 min. The crushed slurry was filtered through three layers of coarse cotton cloth. The filtrate was centrifuged at 4℃ and 10000 r / min for 20 min to separate and obtain the upper sesame oil body (OBE).

[0052] Astaxanthin loading in S2: 0.02% (wt%) of astaxanthin was added to the sesame oil body prepared in S1 and heated at 80℃ for 1 h. Then, the sesame oil body and water were mixed at a mass ratio of 7:3 and stirred at 300 rpm for 30 min at room temperature using a magnetic stirrer. After the system was fully mixed, the pH value of the system was adjusted to 3.0, 7.0 and 11.0 respectively using 1 mol / L NaOH solution and 1 mol / L HCl solution. The system was homogenized at 10000 rpm for 3 min using a T18 high-speed disperser and then the pH of the system was adjusted to neutral. The sesame oil body emulsions loaded with astaxanthin were named A3, A7 and A11 respectively.

[0053] S3 Proanthocyanidin loading: 0.02% proanthocyanidin was added to the sesame oil emulsion loaded with astaxanthin prepared in S2, and stirred at 300 rpm for 1 h at room temperature using a magnetic stirrer. After the system was fully mixed, sesame oil emulsions co-loaded with astaxanthin and proanthocyanidins were obtained and named AP3, AP7 and AP11 respectively.

[0054] In this invention, the stability of the astaxanthin-loaded sesame oil emulsion was determined using a Turbiscan Tower stability analyzer. 20 mL of sample was placed in a sample vial of the stability analyzer, and the vial was placed in the sample cell of the analysis chamber. The scan time for each sample was set to 2 hours. The Turbiscan Stability Index (TSI) value reflects the instability of the emulsion; the higher the TSI value, the more unstable the emulsion. The formula for calculating the TSI value is as follows.

[0055] ;

[0056] Where, x i It is the average intensity of the scattered light from each test by the instrument, x BS It is x iThe average value is n, where n is the number of scans, the test temperature is set to 25℃, and the scan time for each sample is set to 2 h.

[0057] Determination of astaxanthin encapsulation efficiency in emulsion: The encapsulation efficiency was measured by ultraviolet spectrophotometry. 1 mL of emulsion was mixed with 6 mL of dichloromethane / methanol (2:1, v / v) solution. After vortexing, the mixture was centrifuged at 10000 rpm for 10 min. The organic phase of the dichloromethane layer (astaxanthin extract) was collected, and the absorbance was measured at 480 nm using a pre-established standard curve. Encapsulation efficiency (%) = C e / C t ×100%; where C e It refers to the content of encapsulated astaxanthin, C t It refers to the content of encapsulated astaxanthin.

[0058] The microstructure of sesame oil bodies was observed using a confocal laser scanning microscope (CLSM). Specifically, 0.1 wt% FITC (fluorescein isothiocyanate) and 0.1 wt% Nile red were prepared using anhydrous ethanol and used to stain the aqueous (green) and oil (red) phases, respectively. Then, 10 μL of the stained sample was spread onto a glass slide and observed and photographed using a 20x objective lens at laser wavelengths of 488 nm (FITC) and 543 nm (Nile red).

[0059] The freshly prepared sample was spread onto a glass slide, covered with a coverslip, and a drop of cedarwood oil was dropped onto the slide. The microstructure of the sample was then observed under an oil immersion (OM) optical microscope. All images were taken under a 100x oil immersion.

[0060] The encapsulation effect and emulsion stability of the sesame oil emulsion system obtained under different pH conditions in this embodiment are as follows: Figure 1 , Figure 2 As shown.

[0061] Figure 1 The results show that sesame oil bodies exhibit good encapsulation effects for astaxanthin, and the encapsulation effect gradually decreases with increasing pH, reaching its optimal value at pH 3.0. Furthermore, as shown in the figure, the encapsulation effect of astaxanthin is further improved by adding proanthocyanidins to the system under the same conditions. The figure shows that the encapsulation rate reaches 71% at pH 3.0, which is 6.0% higher than that at pH 7.0 (67% encapsulation rate). Therefore, pH 3.0 was selected as the pH value for subsequent experiments in this invention.

[0062] Figure 2As can be seen, the sesame oil emulsion sample (OBE) consistently exhibited the lowest TSI value within 3600 s, demonstrating good short-term stability. However, after 3600 s, the TSI values ​​of samples AP3 and A3 gradually leveled off and eventually fell below those of the sesame oil emulsion sample. This trend indicates that, at pH 3.0 and with the addition of proanthocyanidins, the constructed sesame oil emulsion system exhibited superior dynamic stability during long-term static standing, effectively inhibiting flocculation, aggregation, and phase separation.

[0063] Figure 3 The images show laser confocal microscopy (LCM) images of sesame oil particles loaded with astaxanthin. The images reveal that the phospholipid-protein interfacial membrane on the surface of the sesame oil particles provides excellent elasticity and protection, allowing the structurally intact sesame oil particles to maintain a regular spherical shape within the emulsion. Furthermore, significant bridging flocculation was observed in all samples (indicated by blue arrows). Comparative observation of samples A3, A7, and A11 revealed that sample A3 exhibited the smallest sesame oil particle size and the least bridging flocculation, consistent with the particle size results. In samples AP3, AP7, and AP11 with added astaxanthin, the degree of flocculation between sesame oil particles decreased, resulting in more uniform dispersion. This is because the phospholipid-protein interfacial membrane on the surface of the sesame oil particles has high interfacial activity. Astaxanthin adsorbs onto the sesame oil particle interface through hydrophobic interactions, increasing steric hindrance between the sesame oil particles, inhibiting bridging flocculation, and ultimately leading to more uniform dispersion and improved stability – consistent with TSI analysis results.

[0064] Example 2

[0065] An O / W / O type multi-component composite emulsion gel was prepared using the following method:

[0066] (1) Preparation of sesame oil body, the preparation method of sesame oil body is the same as in Example 1;

[0067] (2) Sunflower seed oil was mixed with a composite gelling agent (monoglyceride: beeswax mass ratio of 1:1) accounting for 8% of the mass of sunflower seed oil and then placed in a water bath at 70°C and stirred at 300 rpm for 1 h until completely dissolved to obtain an oil gel.

[0068] The sesame oil emulsion obtained in S1 was added dropwise to the oil gel and stirred continuously. After dispersing at 6000 rpm for 3 minutes in a high-speed disperser, the mixture was immediately placed in an ice water bath until it solidified, thus obtaining the O / W / O type multi-composite emulsion gel, which was then placed in a 4℃ refrigerator for later use.

[0069] The mass ratios of sesame oil body to oleogel were set as 7:3 (G:B-7:3), 6:4 (G:B-6:4), 5:5 (G:B-5:5), 4:6 (G:B-4:6), and 3:7 (G:B-3:7), respectively.

[0070] In this embodiment, the structure and properties of multiple composite emulsion gels prepared by three-dimensional sesame oil bodies and oil gels with different mass ratios were characterized.

[0071] 2.1 The network structure of each multi-layered composite emulsion gel sample was observed using a laser confocal microscope.

[0072] Laser confocal microscopy images of multiple repeatable emulsion gels prepared from sesame oil bodies and oil gels at different ratios are shown below. Figure 4 As shown.

[0073] Figure 4 The results show that in the G:B-7:3 and G:B-6:4 samples, the oil phase (red) is the continuous phase. However, in the G:B-5:5 sample, both the oil and water phases are distributed in strip-like forms, forming a complex bicontinuous phase structure. This state represents the critical point of phase transition. Furthermore, with the increase in the proportion of sesame oil, the continuous phase transforms into the water phase (green) in the G:B-4:6 and G:B-3:7 samples. Comparative analysis of CLSM images reveals that in the G:B-7:3 and G:B-3:7 samples, the dispersed phase is uniformly distributed within the continuous phase. However, in the G:B-6:4 and G:B-4:6 samples, the dispersed phase droplets exhibit localized aggregation, leading to increased particle size and irregular morphology.

[0074] Furthermore, optical microscopy observations revealed a large number of dispersed emulsion droplets in the G:B-7:3 sample (red arrows), with complete small droplets visible within each droplet. Based on previous experimental analysis, the average particle size of the sesame oil body emulsion was 3.11 ± 0.01 μm. Therefore, it was speculated that these small droplets were sesame oil bodies, and the oleogel could effectively encapsulate these sesame oil bodies to form an oil-in-water-in-oil (O / W / O) dual emulsion gel structure. However, in the G:B-6:4 sample, a small number of complete emulsion droplets were observed within the oleogel (red arrows). Simultaneously, some emulsion droplet structures were blurred, and significant droplet aggregation was observed (green arrows), leading to an increase in the sesame oil body droplet size. The same phenomenon was observed in the corresponding CLSM images. It is evident that with the increase in sesame oil body content, the system could no longer maintain the O / W / O structure. Therefore, the G:B-5:5 sample exhibited a typical bicontinuous phase structure, where the sesame oil bodies and oleogel were both separated and intercalated. In both G:B-4:6 and G:B-3:7 samples, tiny sesame oil droplets were observed distributed around the oil droplets in the oleogel. Furthermore, with increasing sesame oil content, significant tiny droplet adsorption was observed on the surface of the spherical droplets in the G:B-3:7 sample (indicated by the blue arrows). Based on the CLSM images, it is reasonable to infer that the G:B-4:6 and G:B-3:7 samples are oil-in-water (O / W) composite emulsion gels, in which the sesame oil droplets adsorb onto the oleogel surface via a similar picking mechanism, functioning as emulsifiers and thus maintaining the stability of the composite emulsion gel system.

[0075] 2.2 Cryo-bioelectron microscopy characterization and analysis of samples from each delivery system

[0076] Based on observations from CLSM and optical microscopy, the inventors selected three representative samples—G:B-7:3, G:B-5:5, and G:B-3:7—for cryo-bioelectron microscopy characterization. The samples were coated onto a sample chamber containing conductive carbon adhesive, rapidly frozen in liquid nitrogen for 30 seconds, and then transferred to a sample preparation chamber under cryogenic vacuum. After sublimation at -90°C for 10 minutes, gold sputtering was performed for 60 seconds, and finally, the samples were placed in a cryo-scanning electron microscope observation chamber at -140°C with an accelerating voltage of 5 kV for observation.

[0077] like Figure 5As shown, comparing the microstructures of samples G:B-7:3 and G:B-3:7 reveals that the continuous phase of the emulsion gel system in sample G:B-7:3 contains a large number of sesame oil droplets, further confirming the O / W / O structural characteristics of this system. In sample G:B-3:7, the sesame oil forms a dense and porous sponge-like gel network structure with numerous oleogel droplets distributed within it. This phenomenon also confirms that the sesame oil in the sample can form a certain network structure, thus forming a stable O / W type emulsion gel structure. Images of sample G:B-5:5 show that both oleogel and sesame oil are continuously distributed, confirming that this sample has a bicontinuous phase structure, consistent with the microstructure observed by CLSM.

[0078] To further elucidate the influence of oleogels and sesame oil bodies on the structure, the microstructures of the above samples were magnified and observed, and compared with the original sesame oil bodies for analysis. Figure 6 As shown, in the sesame oil body sample, the sesame oil droplets are uniformly dispersed within a sponge-like gel network structure, maintaining good spherical morphology and structural integrity. However, the morphology of some sesame oil droplets in the three composite emulsion gels shows significant changes. In the G:B-7:3 sample, the sesame oil body phase exhibits a disordered three-dimensional network structure, with spherical sesame oil droplets of different sizes observed inside. The larger sesame oil bodies show a wrinkled and uneven surface feature, and there is a clear separation between the oleogel and the sesame oil body at the interface. Based on this, it is inferred that the sesame oil body is dispersed in the oleogel as inactive filler particles. In the G:B-3:7 sample, the surface of the oleogel droplets exhibits irregular micromorphological features, and obvious sesame oil body rupture can be observed in the sesame oil bodies near the oleogel interface. This indicates that some sesame oil bodies ruptured within the composite emulsion gel system, accompanied by aggregation behavior between sesame oil droplets. Similar structural changes are also present in the G:B-5:5 sample.

[0079] 2.3 Storage stability of various multi-component composite emulsion gel samples

[0080] A 35-day observation experiment was conducted at 25 °C, and the phase separation of the system was recorded by photographs. The results are shown below. Figure 7 .

[0081] Figure 7The results showed that the G:B-5:5 sample exhibited the worst storage stability, with liquid precipitation occurring on day 17. The G:B-6:4 sample showed liquid precipitation on day 25, while the G:B-4:6 sample only showed precipitation on day 35. The G:B-7:3 sample remained stable throughout the 35-day storage period without any liquid precipitation. Raman spectroscopy analysis revealed that the lipid acyl chains in the G:B-5:5 sample exhibited high disorder and molecular mobility. This molecular characteristic accelerates the migration and phase separation of components within the system, ultimately leading to decreased storage stability. Furthermore, it was observed that when liquid precipitated from the G:B-6:4 sample, the emulsion gel flowed with the tilt of the sample vial, while the emulsion gel of the G:B-4:6 sample did not exhibit flow. This indicates a difference in the phase separation mechanism between the composite emulsion gels of the G:B-4:6 and G:B-6:4 systems. In conclusion, the O / W / O system formed by the oleogel and sesame oil in a 7:3 mass ratio exhibits excellent storage stability.

[0082] Example 3

[0083] An O / W / O type multi-component composite emulsion gel encapsulation and delivery system co-loaded with astaxanthin and proanthocyanidins was prepared by the following method:

[0084] The preparation of S1 sesame oil body is the same as in Example 1;

[0085] S2 astaxanthin loading

[0086] Astaxanthin was added to the sesame oil body obtained in S1 and heated at 80℃ for 1 h. Then, water was added to the sesame oil body at a mass ratio of sesame oil body:water = 7:3. The mixture was stirred at 300 rpm for 30 min at room temperature using a magnetic stirrer. After the system was fully mixed, the pH value of the system was adjusted to 3.0 using 1 mol / L NaOH solution and 1 mol / L HCl solution, respectively. The mixture was then homogenized at 10000 rpm for 3 min using a T18 high-speed disperser and the pH value of the system was adjusted to neutral to obtain the sesame oil body emulsion loaded with astaxanthin, which was named A3.

[0087] S3 proanthocyanidin loading

[0088] Add 0.02% (wt%) of proanthocyanidins to the sesame oil emulsion A3 loaded with astaxanthin prepared in S2, and stir at 300 rpm for 1 h at room temperature using a magnetic stirrer. After the system is fully mixed, a sesame oil emulsion co-loaded with astaxanthin and proanthocyanidins is obtained, named AP3.

[0089] S4. Sunflower seed oil was mixed with a composite gelling agent (monoglyceride: beeswax mass ratio of 1:1) at 8% of the mass of sunflower seed oil and then placed in a water bath at 70°C and stirred at 300 rpm for 1 h until completely dissolved to obtain an oil gel.

[0090] Finally, the sesame oil emulsions prepared in S2 and S3 were added dropwise to the oil gel and stirred continuously. After dispersing at 6000 rpm for 3 min in a high-speed disperser, the mixture was immediately placed in an ice-water bath until solidified, thus obtaining the O / W / O type multi-composite emulsion gel encapsulation and delivery system loaded with astaxanthin. It was then placed in a 4℃ refrigerator for later use.

[0091] The mass ratio of sesame oil body to oleogel was set to 7:3 (G:B-7:3 A3), 7:3 (G:B-7:3 AP3), 6:4 (G:B-6:4 A3), and 6:4 (G:B-6:4 AP3), respectively.

[0092] The photostability and storage stability of the active substances in the O / W / O type multi-component composite emulsion gel encapsulation and delivery system co-loaded with astaxanthin and proanthocyanidins prepared in this embodiment were determined. The specific procedures are as follows:

[0093] Photostability: Samples were placed in transparent sample vials and exposed to an 8 W UV lamp at a wavelength of 365 nm. Equal amounts of sample were taken after 1, 2, 3, 4, and 5 days of irradiation. The astaxanthin content in the samples after UV irradiation was determined by UV spectrophotometry. The absorbance was measured at 480 nm using a pre-established standard curve. The astaxanthin retention rate was calculated using the following formula: Retention rate (%) = C d / C0×100%; where C d C0 represents the astaxanthin content measured when the light exposure time is d. C0 indicates the astaxanthin content in the initial stage of the sample.

[0094] Storage stability: The samples were placed in transparent sample bottles and placed in an incubator at 25°C in the dark. Equal amounts of samples were taken at 7, 14, 21 and 28 days of storage, and the retention rate of astaxanthin in the samples after storage was determined by ultraviolet spectrophotometry.

[0095] Figure 8 Figures A and B in the middle show the photostability and storage stability of the O / W / O type multi-component emulsion gel delivery system co-loaded with astaxanthin and proanthocyanidins, respectively.

[0096] Depend on Figure 8As shown in Figure A, after five days of UV irradiation, the astaxanthin retention rate in the samples was still as low as 77.93±0.77%, indicating that the O / W / O composite emulsion gel has excellent UV protection for astaxanthin, effectively delaying its degradation under UV irradiation and improving its photostability. With the increase of the oil-gel ratio, the astaxanthin retention rate gradually increased, indicating that the O / W / O composite emulsion gel with high oil phase gel content has a denser network structure, which helps to more effectively fix and protect astaxanthin molecules, thereby reducing their degradation under UV irradiation. In addition, the addition of proanthocyanidins increased the astaxanthin retention rate in the short term, but its protective effect weakened and showed a downward trend with prolonged UV irradiation time. This also caused the line graphs of astaxanthin retention rates for samples G:B-7:3 A3 and G:B-7:3 AP3 to cross on the fifth day, and the retention rates for samples G:B-6:4 A3 and G:B-6:4 AP3 to cross on the fourth day. This indicates that the photoprotective effect of proanthocyanidins on astaxanthin has a time effect. In the early stage of ultraviolet irradiation, it can enhance the photostability of astaxanthin, but as the irradiation time increases, its protective effect is gradually lost, and it may even accelerate the ultraviolet degradation of astaxanthin.

[0097] The effect of different astaxanthin and proanthocyanidin co-loaded O / W / O composite emulsion gel delivery systems on astaxanthin retention rate during a 28-day storage period was investigated at 25℃ to evaluate the storage stability of the system. Figure 8 As shown in Figure B, the astaxanthin retention rate of all samples showed a slow decreasing trend with prolonged storage time. However, after 28 days of storage at 25℃, the lowest astaxanthin retention rate was still 82.22 ± 0.79%, indicating that the O / W / O composite emulsion gel has excellent storage protection ability for astaxanthin and can effectively delay its degradation during room temperature storage. With the increase of the oil gel ratio, the astaxanthin retention rate showed an increasing trend. This phenomenon is due to the fact that the higher the proportion of oil gel, the stronger the gel strength of the O / W / O composite emulsion gel, which can form a denser spatial barrier and enhance the physical protection of astaxanthin. The addition of proanthocyanidins further improved the astaxanthin retention rate of the system. This result is consistent with the conclusion of the UV oxidative stability experiment, indicating that the addition of proanthocyanidins has a protective effect on the storage stability of astaxanthin.

[0098] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. The application of sesame oil bodies in the preparation of O / W / O type multi-component composite emulsion gels, characterized in that, The sesame oil body is obtained by the following method: sesame seeds are soaked in a NaHCO3 solution with a concentration of 0.1~0.2 mM and a pH of 9.0~10.0 to obtain a sesame solution. The sesame solution is then crushed in a high-speed blender. The crushed slurry is filtered, centrifuged, and separated to obtain the upper sesame oil body.

2. The application as described in claim 1, characterized in that, The O / W / O type multi-component composite emulsion gel is formed by mixing sesame oil and oil gel, dispersing at high speed, and then cooling and solidifying. The oil gel is prepared using monoglycerides and beeswax as gelling agents and vegetable oil as the oil phase. The vegetable oil is selected from sunflower seed oil and corn oil.

3. A method for preparing an O / W / O type multi-component composite emulsion gel, characterized in that, The steps include the following: (1) Preparation of sesame oil body Sesame seeds were soaked in a NaHCO3 solution with a concentration of 0.1~0.2 mM and a pH of 9.0~10.0 to obtain a sesame solution. The sesame solution was then crushed in a high-speed blender. The crushed pulp was filtered and centrifuged to separate the upper sesame oil body. (2) Preparation of O / W / O type multi-layer composite emulsion gel Monoglycerides and beeswax are added to sunflower seed oil, mixed, heated and stirred until completely dissolved to obtain an oil gel; the total mass of the monoglycerides and beeswax accounts for 5% to 8% of the mass of sunflower seed oil, and the mass ratio of the monoglycerides to beeswax is 1:1 to 3; The sesame oil body obtained in (1) was added dropwise to the above oil gel and stirred continuously. The mass ratio of oil gel to sesame oil body was 6~7:3~4. After high-speed dispersion, the mixture was immediately placed in an ice water bath until solidified, thus obtaining the O / W / O type multi-composite emulsion gel.

4. The preparation method according to claim 3, characterized in that, The mass ratio of sesame seeds to NaHCO3 solution mentioned in (1) is 1:5~10.

5. The preparation method according to claim 3, characterized in that, (2) The added fat-soluble components account for 0.01% to 0.03% of the mass of sesame oil body, and the mass ratio of sesame oil body to water is 6 to 8: 2 to 4.

6. The preparation method according to claim 3, characterized in that, (2) The conditions for high-speed dispersion are: rotation speed 5500~6500rpm, processing time 2~5min.

7. The application of the O / W / O type multi-component composite emulsion gel prepared by the preparation method according to any one of claims 3 to 6 as a delivery system, characterized in that, The composite emulsion gel is used to deliver fat-soluble components, photosensitive components, and easily oxidized components. The fat-soluble components are selected from any one of astaxanthin, carotene, lutein, and curcumin, and the photosensitive components are selected from any one of polyphenols, proanthocyanidins, and vitamins.

8. A method for preparing an O / W / O type multi-component composite emulsion gel encapsulation and delivery system co-loaded with astaxanthin and proanthocyanidins, characterized in that, It is prepared by the following steps: Preparation of S1 sesame oil Sesame seeds and NaHCO3 solution were mixed at a mass ratio of 1:6~8 to obtain a sesame solution. The concentration of NaHCO3 solution was 0.1~0.2 mM and the pH was 9.0~10.

0. The sesame solution was then crushed in a high-speed blender. The crushed pulp was filtered and centrifuged to separate the upper sesame oil body. Loading of S2 fat-soluble components Add fat-soluble components to the sesame oil body obtained in S1, heat at 60~90℃ for 0.5~2 h, then add water to the sesame oil body, stir and mix at room temperature, adjust the pH of the system to 3.0~7.0, homogenize at 8000~12000 rpm for 2~3 min, and then adjust the pH of the system to neutral to obtain a sesame oil body emulsion loaded with fat-soluble components. The fat-soluble component is selected from any one of astaxanthin, carotene, lutein, and curcumin; S3 proanthocyanidin loading Proanthocyanidins are added to the sesame oil emulsion loaded with fat-soluble components prepared in S2, and the mixture is stirred thoroughly at room temperature to obtain a sesame oil emulsion co-loaded with fat-soluble components and proanthocyanidins; the mass ratio of proanthocyanidins to fat-soluble components is 1~2:

1. Preparation of an O / W / O type multi-component composite emulsion gel delivery system co-loaded with S4 astaxanthin and proanthocyanidins Monoglycerides and beeswax are added to sunflower seed oil, mixed, heated and stirred until completely dissolved to obtain an oil gel; the total mass of the monoglycerides and beeswax accounts for 5% to 8% of the mass of sunflower seed oil, and the mass ratio of the monoglycerides to beeswax is 1:1 to 3; The sesame oil emulsion co-loaded with the fat-soluble component and proanthocyanidins prepared in S3 was added dropwise to the above oleogel while continuously stirring. The mass ratio of oleogel to sesame oil emulsion co-loaded with fat-soluble component and proanthocyanidins was 6~7:3~4. After high-speed dispersion, the mixture was immediately placed in an ice-water bath until solidified, thus obtaining the O / W / O type multi-composite emulsion gel delivery system co-loaded with astaxanthin and proanthocyanidins.

9. The preparation method according to claim 8, characterized in that, S2 is heated at 75~85℃ for 1~1.5 h, and the stirring speed at room temperature is 200~400 rpm.

10. The preparation method according to claim 8, characterized in that, In S2, the pH of the system was adjusted to 3.0, and homogenized at 9000~11000 rpm for 2~3 min.

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