Composite emulsion for improving insomnia and preparation method thereof

Abstract

The invention belongs to the technical field of functional preparations, and discloses a composite emulsion for improving insomnia and a preparation method thereof. The composite emulsion is prepared from the following components in percentage by volume: 70 to 95 percent of modified fucoidin solution with the concentration of 0.5 to 3 mg / mL, and the balance of melatonin-containing medium chain triglyceride, the content of the melatonin in the composite emulsion is 0.02 wt%. The compound emulsion is strong in stability and high in bioavailability, and can effectively resist an acid environment in a stomach and protect melatonin from being delivered to intestinal tracts. Through verification, the average core sleep duration of a subject taking the compound emulsion is increased by 21.05% compared with that of the subject taking melatonin only; the average waking time is shortened by 40% compared with that of melatonin, and the effect is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of functional preparations and relates to a composite emulsion for improving insomnia and a preparation method thereof. Background Art

[0002] Fucoidan (FUC) is non-toxic and highly biocompatible. It has antiviral, anti-inflammatory, anti-tumor, and immunomodulatory properties and is widely used in treatment, pharmacy, diagnosis, and drug delivery. FUC has great research potential in the delivery of nutrients and drugs by using it as a delivery carrier and preparing it with other bioactive ingredients. For example, Chen Xing et al. prepared whey protein isolate (WPI) and FUC into a binary composite system, explored the characteristics of the WPI-FUC complex under different conditions, and screened out the best process method.

[0003] The existing patent 202311498952.6 discloses a modified sulfated polysaccharide compound and a preparation method thereof. The patent uses concentrated sulfuric acid as a catalyst to carry out an esterification modification reaction to prepare a modified esterified polysaccharide compound, which has the ability to significantly improve the quality of fucoidan. However, the concentrated sulfuric acid used in the patent is highly corrosive and there are safety issues in the production of the reagent, which has a certain adverse effect on the medicinal safety of the modified polysaccharide.

[0004] The existing patent 201810861854.7 discloses an esterified modified soybean polysaccharide oil-in-water emulsion and its preparation method, introduces octenyl succinate starch ester, and utilizes the modified starch characteristics to improve the emulsification activity of polysaccharides. This invention effectively improves the emulsification stability of polysaccharides. However, the octenyl succinate starch ester introduced in this application is a chemical macromolecular particle, which has a certain impact on the safety of the production of nano-functional preparations.

[0005] Therefore, how to improve the emulsification properties of natural polysaccharides and increase the bioavailability of functional ingredients remains an urgent industrial problem to be solved. Summary of the invention

[0006] In order to improve the emulsification of natural polysaccharides and enhance the bioavailability of functional components, the present invention provides a composite emulsion for improving insomnia and a preparation method thereof.

[0007] First, the present invention provides a composite emulsion for improving insomnia, wherein the components of the composite emulsion are: in terms of volume percentage, 70-95% of a modified fucoidan solution with a concentration of 0.5-3 mg / mL, and the remainder is a medium-chain triglyceride containing melatonin; the content of melatonin in the composite emulsion is 0.02wt%.

[0008] Furthermore, for the above-mentioned composite emulsion, the preparation method of the modified fucoidan is: Disperse fucoidan in pure water to prepare a 20wt% fucoidan solution, and adjust the pH of the fucoidan solution system to 8.5 with a 0.5mol / L NaOH solution; Add 3-9% octenyl succinic anhydride dilution and continue stirring the reaction at 45°C for 1 hour, during which the pH of the reaction solution is maintained at 8.5 with 0.5 mol / L NaOH solution; The reaction was terminated by adjusting the pH to 6.0 with 0.1 mol / L HCl solution; The reaction solution was dialyzed for 48 hours using a dialysis bag with a molecular weight cutoff of 3500Da, evaporated and concentrated to remove water, and then freeze-dried to obtain modified fucoidan; The octenyl succinic anhydride dilution solution is prepared by diluting octenyl succinic anhydride (OSA) with 5 times the volume of anhydrous ethanol.

[0009] On the other hand, the present invention provides a method for preparing the composite emulsion, comprising: Dissolve the modified fucoidan in distilled water to prepare a modified fucoidan solution with a concentration of 0.5-3 mg / mL, heat to 85°C and maintain for 30 min, then cool to 50°C; Dissolving melatonin in medium-chain triglycerides so that the content of melatonin in the composite emulsion is 0.02 wt %, to obtain medium-chain triglycerides containing melatonin; The modified fucoidan solution is mixed with the medium chain triglyceride containing melatonin, and the mixing ratio is: in terms of volume percentage, the modified fucoidan solution is 70-95%, and the balance is the medium chain triglyceride containing melatonin; The mixture is homogenized in a shearing machine and then ultrasonically treated for 1 to 5 minutes to obtain the composite emulsion.

[0010] Furthermore, in the preparation method of the above composite emulsion, the homogenization treatment conditions are: 10000 rpm, 3 min.

[0011] Finally, the present invention provides an application of the composite emulsion. Specifically, the composite emulsion is used for improving insomnia.

[0012] Compared with the prior art, the present invention "a composite emulsion for improving insomnia and a preparation method thereof" has the following beneficial effects: The present invention uses octenyl succinic anhydride (OSA) to modify fucoidan, which effectively improves the emulsification ability of fucoidan, forms a composite emulsion system with strong stability and high bioavailability, helps to effectively resist the acidic environment in the stomach, and protects the delivery of melatonin to the intestine. It has been verified that the average core sleep time of the test group taking the composite emulsion increased by 40.8% compared with the control group and 21.05% compared with the melatonin group. For the average wakefulness time, the test group was 62.5% shorter than the control group and 40% shorter than the melatonin group. In addition, the number of effective and effective people in the test group were 6 and 10, respectively, which increased by 3 and 2, respectively, compared with the melatonin group, showing a significant improvement. The total effective rate was increased by 25% compared with the melatonin group, with significant effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The degree of substitution (DS) of fucoidan under different addition amounts of octenylsuccinic anhydride diluent.

[0014] Figure 2 Scanning electron micrographs of fucoidan (FUC) and modified fucoidan (OSA-FUC).

[0015] Figure 3 The particle size changes of the emulsion under different OSA-FUC concentration conditions.

[0016] Figure 4 The particle size changes of the emulsion under different MCT contents.

[0017] Figure 5 The particle size changes of the emulsion under different ultrasonic power conditions.

[0018] Figure 6 The particle size changes of the emulsion under different ultrasonic time conditions.

[0019] Figure 7 Turbidity and whiteness of the emulsion under different MCT contents.

[0020] Figure 8 Turbidity and whiteness of the emulsion under different OSA-FUC concentration conditions.

[0021] Fig. 9 The turbidity and whiteness of the emulsion under different ultrasonic power conditions.

[0022] Fig.10 The turbidity and whiteness of the emulsion under different ultrasonic time conditions.

[0023] Fig.11 The results of microstructure observation are shown in Figure 1. A is the result of optical microscope observation, B1 and B2 are the results of scanning electron microscope observation, and C1~C3 are the results of confocal laser scanning microscope (CLSM) observation.

[0024] Fig.12 The particle size distribution trend under different pH conditions.

[0025] Fig.13 is the average particle size under different pH conditions.

[0026] Fig.14 The droplet morphology under different pH conditions.

[0027] Fig.15 Figure 2 shows the particle size distribution trend under different NaCl concentrations.

[0028] Fig.16 is the average particle size under different NaCl concentration conditions.

[0029] Fig.17 The droplet morphology under different NaCl concentration conditions.

[0030] Fig.18 This is the cumulative release of melatonin from MCT and compound emulsions containing melatonin at different digestion stages.

[0031] Fig.19 Cumulative release of free fatty acids (FFA) from MCT and composite emulsions containing melatonin at different digestion stages.

[0032] Fig. 20 This is the fitting curve of the cumulative release of FFA from the composite emulsion during digestion.

[0033] Fig.21 This is the fitting curve of the cumulative release of FFA during the digestion of MCT containing melatonin. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1 This example describes the modification of fucoidan.

[0036] Disperse fucoidan in pure water to prepare a 20wt% fucoidan (FUC) solution, and adjust the pH of the fucoidan solution system to 8.5 with a 0.5mol / L NaOH solution; Add 3-9% octenyl succinic anhydride dilution and continue stirring the reaction at 45°C for 1 hour, during which the pH of the reaction solution is maintained at 8.5 with 0.5 mol / L NaOH solution; The reaction was terminated by adjusting the pH to 6.0 with 0.1 mol / L HCl solution; The reaction solution was dialyzed for 48 h using a dialysis bag with a molecular weight cutoff of 3500 Da, evaporated and concentrated to remove water, and freeze-dried to obtain powdered modified fucoidan (OSA-FUC); In the above steps, the octenyl succinic anhydride dilution solution is prepared by diluting octenyl succinic anhydride (OSA) with 5 times the volume of anhydrous ethanol.

[0037] Figure 1 The DS of fucoidan under different addition conditions of octenyl succinic anhydride diluent. DS is used to characterize the esterification degree of fucoidan and is determined by titration. Figure 1 It can be seen that when the OSA concentration is 3%, 6% and 9%, the DS values ​​are 0.020, 0.028 and 0.030, respectively, indicating that OSA-modified fucoidan (OSA-FUC) was prepared through the esterification reaction of FUC and OSA.

[0038] Figure 2 The following are scanning electron micrographs of fucoidan (FUC) and modified fucoidan (OSA-FUC). Figure 2 It can be seen that the surface morphology of fucoidan has changed significantly after being modified by OSA. The surface of the modified fucoidan has obvious wrinkles, a loose structure, and cavities, which effectively promotes the emulsification properties.

[0039] Example 2 This example describes the preparation of the composite emulsion.

[0040] OSA-FUC was dissolved in distilled water to prepare an OSA-FUC solution with a concentration of 0.5-3 mg / mL, heated to 85°C and maintained for 30 min, and then cooled to 50°C.

[0041] Take 0.004 g of melatonin (the density of the composite emulsion is regarded as 1 g / mL) and dissolve it in 1-6 mL of medium-chain triglycerides (MCT) to prepare MCT containing melatonin.

[0042] 14-19 mL of OSA-FUC solution and 1-6 mL of MCT containing melatonin were mixed to prepare a mixed solution with a total volume of 20 mL. At this time, the volume proportion of OSA-FUC solution in the mixed solution was 70-95%, the volume proportion of MCT containing melatonin in the mixed solution was 5-30%, and the content of melatonin in the mixed solution was 0.02 wt%.

[0043] The mixed solution was stirred at 10000 rpm for 3 min in a high-speed shearing machine (Shanghai Sample Model Factory, FJ200-SH) for homogenization, and then ultrasonically treated for 1 to 5 min at 0, 100, 200, 300, 400, and 500 W using an ultrasonic cell disruptor (Wuxi Xinyi, VOSHIN-1500C) to obtain composite emulsions of different concentrations.

[0044] Example 3 This example describes the effects of preparation parameters (OSA-FUC concentration, MCT content, ultrasound power, and ultrasound time) on the particle size, turbidity, and whiteness of the composite emulsion.

[0045] 1. Effect of preparation parameters on emulsion particle size The stability of the emulsion is affected by many factors. According to Stokes' law, the particle size can be used as one of the factors to determine whether the emulsion preparation is successful. The emulsion obtained above was measured and compared with the particle size using a Malvern laser particle size analyzer. Parameter settings: the refractive index of the dispersed phase is 1.5, the absorptivity is 0.001; the refractive index of the continuous phase is 1.333; the test temperature is 25°C.

[0046] 1) Effect of OSA-FUC concentration on the particle size of composite emulsion According to the composite emulsion preparation method described in Example 2, the effect of OSA-FUC concentration on the particle size of the composite emulsion was determined. In this test, the setting conditions of other parameters were: MCT content was 5% v / v, ultrasonic power was 400W, and ultrasonic time was 3min. The test results are shown in Figure 3 .

[0047] Figure 3 The particle size changes of the emulsion under different OSA-FUC concentrations (0.5, 1, 1.5, 2, 2.5, 3 mg / mL) are shown. Figure 3 As shown in the figure, with the increase of OSA-FUC concentration, the particle size first decreases and then increases. The initial particle size of the emulsion decreases from 5.15±0.14μm (0.5mg / mL) to 1.44±0.14μm (2.0mg / mL). When the OSA-FUC concentration is >2.0mg / mL, the particle size increases to 2.16±0.03μm (3.0mg / mL). This trend may be attributed to the increase in OSA-FUC concentration, which increases the coverage of the composite emulsion droplets, resulting in a decrease in particle size. As the interface layer of the unit composite emulsion droplet gradually thickens, the emulsion particle size gradually increases. Based on the test results, the preferred concentration of OSA-FUC is 2.0mg / mL.

[0048] 2) Effect of MCT content on particle size of composite emulsion According to the composite emulsion preparation method described in Example 2, the effect of MCT content on the particle size of the composite emulsion was determined. In this experiment, the setting conditions of other parameters were: OSA-FUC concentration was 2.0 mg / mL, ultrasonic power was 400 W, and ultrasonic time was 3 min. The test results are shown in Figure 4 .

[0049] Figure 4 The particle size changes of the emulsions with different MCT contents (5, 10, 15, 20, 25, 30% v / v) are shown. Figure 4 It can be seen that with the increase of MCT content, the emulsion particle size gradually increases from 5.25±0.13μm (5% v / v MCT) to 22.10±0.21μm (30% v / v MCT), and the emulsion particle size differences between the groups are significant. When the particle size is the smallest, the MCT content is 5% v / v. This may be because OSA-FUC can form a network structure through non-covalent bond interactions, restricting the movement of the composite emulsion, and under the condition of low MCT content, the distance between the emulsion droplets in the composite emulsion system is far, and it is not easy to produce a cross-linked network, so the particle size is small. Based on the test results, the preferred content of MCT is 5% v / v.

[0050] 3) Effect of ultrasonic power on particle size of composite emulsion According to the preparation method of the composite emulsion described in Example 2, the effect of ultrasonic power on the particle size of the composite emulsion was determined. In this experiment, the setting conditions of other parameters were: OSA-FUC concentration was 2.0 mg / mL, MCT content was 5% v / v, and ultrasonic time was 3 min. The experimental results are shown in Figure 5 .

[0051] Figure 5 The particle size changes of the emulsion under different ultrasonic powers (0W, 100W, 200W, 300W, 400W) are shown. Figure 5 As shown in the figure, when the ultrasonic power increases from 100W to 400W, the particle size decreases from 9.07±0.32μm to 2.84±0.06μm. This shows that the cavitation and shearing effects of ultrasound can break up and disperse the emulsified droplets, thus forming a uniform system. However, as the ultrasonic power increases, the heat energy generated will promote the mutual aggregation of droplets, and more severe cavitation will strongly squeeze the droplets to recombine, destroy the uniformity of the liquid, and cause more inhomogeneous agglomerates to appear. Based on the test results, the preferred power for ultrasonic treatment is 400W.

[0052] 4) Effect of ultrasonic time on particle size of composite emulsion According to the preparation method of the composite emulsion described in Example 2, the effect of ultrasonic time on the particle size of the composite emulsion was determined. In this experiment, the setting conditions of other parameters were: OSA-FUC concentration was 2.0 mg / mL, MCT content was 5% v / v, and ultrasonic power was 400 W. The test results are shown in Figure 6 .

[0053] Figure 6 The figure shows the change of particle size of the emulsion under different ultrasonic time conditions (0min, 1min, 2min, 3min, 4min, 5min). Figure 6 As shown in the figure, when there is no ultrasonic treatment (i.e. 0 min), the particle size of the emulsion is 9.41±0.69 μm, and when the ultrasonic treatment time is 4 min, the particle size reaches the minimum value of 1.34±0.03 μm. This shows that ultrasonic treatment for 4 min can significantly reduce the particle size. Based on the test results, the preferred time for ultrasonic treatment is 4 min.

[0054] 2. Effect of preparation parameters on turbidity and whiteness The composite emulsion was diluted 200 times in water, and the absorbance of the sample was measured at 600 nm. The turbidity and whiteness values ​​of the emulsion were measured using a colorimeter. The turbidity and whiteness were calculated using the following formula:

[0055]

[0056] Among them, A 600 is the absorbance at 600nm, 200 is the dilution factor, 0.01 is the optical path difference, L * For brightness, a * is redness / greenness, b * Yellowness / blueness.

[0057] Table 1 shows the brightness under different MCT contents, OSA-FUC concentrations, different ultrasound powers and ultrasound times ( L * )、Red and Green Value( a * )、Yellow-blue( b * )、Color Saturation( c * ), hue angle (H), and according to the calculation formula of turbidity and whiteness, the influence of the above four preparation parameters on turbidity and whiteness is plotted. When measuring the influence of the above parameters on turbidity and whiteness, the settings of the remaining parameters are the same as "1. Influence of preparation parameters on emulsion particle size".

[0058] Table 1. Effect of preparation parameters on turbidity and whiteness

[0059] Figure 7 The effect of different MCT contents on turbidity and whiteness, which are important parameters reflecting the stability and uniformity of the emulsion system. At the same time, the visual appearance of the emulsion is an important factor affecting consumer acceptance during product processing. The higher the turbidity and whiteness values ​​of the emulsion, the more it tends to be milky white. When the MCT content is 5-15% v / v, the turbidity of the composite emulsion increases significantly from 32734.44±18.42 to 81767.04±64.46 (p<0.05); when the MCT content is greater than 15% v / v, the turbidity of the composite emulsion decreases significantly (p<0.05), which is due to the excessive MCT content causing its own precipitation.

[0060] Figure 8 The effect of different OSA-FUC concentrations on turbidity and whiteness. As the OSA-FUC concentration increases, the turbidity of the emulsion increases significantly (p<0.05), and the whiteness does not change significantly. In addition, it can be seen from Table 1 that as the OSA-FUC concentration increases, the emulsion b * and c * It gradually increases and H gradually approaches 90°, indicating that the increase in OSA-FUC concentration makes the composite emulsion more inclined to dark yellow.

[0061] Fig. 9 , 10 are the effects of different ultrasonic powers and ultrasonic time on turbidity and whiteness, respectively. Fig. 9 , 10 It can be seen that compared with the emulsion without ultrasonic treatment, the whiteness and turbidity of the emulsion treated with ultrasonic treatment increased significantly (p<0.05), and the stability and uniformity were improved.

[0062] In summary, the composite emulsion has the best stability and uniformity when using an OSA-FUC concentration of 2.0 mg / mL, an MCT content of 5% v / v, and 400 W ultrasonic treatment for 4 min.

[0063] Example 4 This example describes the observation of the microstructure of the composite emulsion.

[0064] 10 μL of the composite emulsion (OSA-FUC concentration of 2.0 mg / mL, 5% v / v MCT) was dropped on a glass slide, covered with a cover glass, and observed under a 100x upright microscope to evaluate the droplet size and aggregation state. MCT and OSA-FUC were stained with Nile red and Nile blue dyes, respectively, and observed with a confocal laser scanning microscope (CLSM). 2 mL of the composite emulsion was stained with a mixture of Nile blue and Nile red fixed fluorescent dyes for 5 minutes, then stored in the dark for 2 hours to observe its morphology. The fluorescent dye was activated using a 488 nm argon laser or a 633 nm helium-neon laser.

[0065] Fig.11 The microstructure observation results are given by Fig.11 It can be seen that through optical microscopy observation (A), the composite emulsion system is uniform, and the droplets formed are dispersed with each other, which effectively prevents aggregation under long-term storage. Under the scanning electron microscope (B1, B2), the melatonin encapsulated in the composite emulsion is in the form of irregular small particles, while the formed emulsion is spherical, with a smooth surface and no irregular structures attached to the surface. CLSM can be used to gain a deeper understanding of how OSA-FUC stabilizes droplets, thereby understanding the emulsion stabilization mechanism. The green layer and red sphere in the CLSM results (C1~C3) represent OSA-FUC and MCT, respectively. It can be clearly observed that all MCTs are encapsulated by OSA-FUC, and the emulsion is stable.

[0066] Example 5 This example describes the resistance of the composite emulsion to different environmental stresses.

[0067] 1. Effect of pH on emulsion stability The pH of the emulsion was adjusted to 2.0, 4.0, 6.0, 8.0 and 10.0 using 1 mol / L HCl and 1 mol / L NaOH. After the test tube was wrapped with tin foil and placed in a dark place for 6 h, the particle size distribution trend and average particle size under different pH conditions were analyzed using a Malvern 3000 laser particle size analyzer, and the changes in droplet morphology were observed using a microscope.

[0068] Fig.12 is the particle size distribution trend under different pH conditions. Fig.12 It can be seen that under different pH conditions, the 10μm particle size distribution accounts for the highest proportion. Fig.13 , Fig.14 are the average particle size and droplet morphology under different pH conditions. Fig.13 , Fig.14It can be seen that under alkaline conditions, the emulsion particle size increases, the droplet morphology becomes larger, and the liquid aggregation state increases, but no segregation occurs; under neutral and acidic conditions, the emulsion droplets are dispersed, the particle size is small, and the particle size change is not obvious compared with the newly prepared emulsion. This shows that the composite emulsion is more stable under neutral and slightly acidic conditions, further indicating that the composite emulsion can effectively resist the acidic environment in the stomach and protect the delivery of melatonin to the intestine.

[0069] 2. Effect of NaCl concentration on emulsion stability After adjusting the NaCl concentration (0-0.5 M), wrapping the test tube with tin foil and placing it in the dark for 6 h, the particle size distribution trend and average particle size were analyzed using a Malvern 3000 laser particle size analyzer, and the droplet morphology changes were observed using a microscope.

[0070] Fig.15 is the particle size distribution trend under different NaCl concentration conditions. Fig.15 It can be seen that under different NaCl concentration conditions, the emulsion particle size distribution shows a bimodal morphology, with the particle size of 10 μm accounting for the highest proportion. Fig.16 , Fig.17 are the average particle size and droplet morphology under different NaCl concentration conditions, respectively. Fig.16 , Fig.17 It can be seen that the emulsion has good stability at low NaCl concentrations. As the NaCl concentration increases, the particle size tends to gradually increase and aggregate, but no segregation occurs, indicating that the composite emulsion can maintain system stability without being destroyed in a certain concentration of NaCl environment.

[0071] Example 6 This example describes the digestion of a composite emulsion, using MCT containing melatonin as a control.

[0072] 1. Experimental Design (1) Simulation of oral cavity stage Prepare simulated saliva fluid (SSF): the total volume is 100 mL, including Na 2 HPO 4 The concentration is 0.55 g / L, NaH 2 PO 4 is 0.27 g / L, α-amylase is 1500 U / mL, CaCl 2 0.3 mol / L, and 1 mol / L HCl was used to adjust the pH to 7.0. 5 mL of freshly prepared SSF was preheated in a 37°C water bath, then mixed with an equal volume of the composite emulsion, and shaken in a constant temperature water bath at 100 r / min and 37°C for 2 min to obtain a mixed solution a.

[0073] (2) Simulated gastric stage Prepare simulated gastric fluid (SGF): the total volume is 50 mL, the NaCl concentration is 0.342 M (2 g / L), the pepsin is 3.2 g / L, and the pH is adjusted to 1.2 with 1 mol / L HCl. Take 5 mL of the mixed solution a obtained in step (1) and 15 mL of freshly prepared SGF, mix them, adjust the pH to 1.2 with 1 mol / L HCl, and shake in a constant temperature water bath at 100 r / min and 37°C for 2 h to obtain a mixed solution b.

[0074] (3) Simulated small intestine stage Prepare simulated small intestinal fluid (SIF): total volume 50 mL, bile salt concentration 48.5 mg / mL, pancreatic lipase 12 mg / mL, CaCl 2 The pH value is 0.75 mol / L and the pH value is 7.0. Take 10 mL of the mixed solution b obtained in step (2), add the same volume of freshly prepared SIF, mix thoroughly, adjust the pH value to 7.0 with 0.1 mol / L NaOH, and oscillate in a constant temperature water bath at 100 r / min and 37°C for 2 h to simulate small intestinal digestion. During this period, 0.2 mol / L NaOH is used to maintain the pH value at 7.0. After the digestion, a mixed solution c is obtained. The volume of NaOH consumed during the small intestinal digestion is recorded and the free fatty acids (FFA) are calculated.

[0075]

[0076] In the above formula, C NaOH : The concentration of NaOH solution during titration (mol / L), V NaOH : The volume of NaOH solution consumed in 2 h of digestion (L), M oil : Average relative molecular weight of MCT (g / mol).

[0077] 2. Test results (1) Melatonin release The mixed solution c is used as the micelle component, and the release of melatonin is reflected by the change in the content of melatonin in the micelle component. Fig.18 The cumulative release of melatonin from MCT containing melatonin and the composite emulsion at different digestion stages. The figure shows that the cumulative release of melatonin from the composite emulsion (55.32±1.21%) is higher than that from MCT containing melatonin (24.20±1.11%), indicating that the in vitro bioaccessibility of melatonin in the composite emulsion is better than that of MCT containing melatonin.

[0078] In general, the bioaccessibility of melatonin is positively correlated with the release of FFA, and the presence of some FFA is believed to increase the solubility of melatonin in micelles. Fig.18The results presented may be due to the fact that the OSA-FUC binding layer of the composite emulsion effectively disperses the droplets to form smaller particles, with a larger surface area exposed to pancreatic lipase, and a higher degree of enzymatic hydrolysis of MCT into free fatty acids (FFA), thereby releasing more melatonin; while for MCT containing melatonin, the bile salts and pancreatic lipase attached to the surface of MCT cause them to form micelles, delaying the release of melatonin.

[0079] (2) Free fatty acid (FFA) release The release of FFA was determined by the pH-stat method; the amount of NaOH required to maintain a neutral pH during digestion was recorded to track the extent of MCT digestion. Fig.19 The cumulative release of free fatty acids (FFA) from MCT and composite emulsions containing melatonin at different digestion stages. Fig.19 As shown in the figure, from 0 to 20 minutes, the FFA release of MCT containing melatonin and the composite emulsion increased rapidly with time; from 20 to 180 minutes, the FFA release of the composite emulsion reached 40% of the total release, which was higher than that of MCT containing melatonin (25%), and it still maintained an upward trend after 180 minutes. This result shows that the composite emulsion system is more conducive to the sustained release of FFA.

[0080] Subsequently, five commonly used release kinetic models were used to evaluate the FFA release during the small intestinal digestion stage (see Table 2).

[0081] Table 2. FFA release kinetics model during small intestinal digestion

[0082] According to the release kinetics model in Table 2, the Fig. 20 , 21 The fitting curves of the cumulative release of FFA from the composite emulsion and MCT containing melatonin during small intestinal digestion are shown in Figure 2. From the linear value, for MCT containing melatonin, the first-order model (M t / M ∞ =e （k1×t） +C 1 ) has the highest fit (R 2 =0.98); for composite emulsions, the Peppas-Sahlin model has the highest degree of fit (R 2 =0.98, followed by the first-order model (R 2= 0.94). This result indicates that the main mechanism of MCT in small intestine digestion is direct diffusion. The rapid release of FFA within the first 20 min indicates that pancreatic lipase rapidly attaches to the surface of MCT and decomposes it. Subsequently, the release rate of FFA slows down, which may be due to the bile salts adsorbing layer by layer on the surface of MCT to form a new protective layer, blocking the contact between MCT and pancreatic lipase, and inhibiting the decomposition of MCT.

[0083] Both systems showed high goodness of fit and correlation in the Peppas - Sahlin model. The difference in the m value (0.49 ± 0.05) in the model indicates that the two systems have different FFA release mechanisms: 0.43 < m < 0.85 corresponds to the Fick diffusion mechanism, which is a synergistic mechanism of substance release diffusion and particle dissolution. The process is generally as follows: The composite emulsion droplets come into contact with the complex enzyme system in the small intestine, the OSA - FUC shell structure is damaged, and lipase rapidly enters the interior to decompose MCT, releasing free fatty acids. As the action time prolongs, MCT is gradually depleted. In addition, micelles are gradually formed, and the micelle layer prevents lipase from entering the interior of the droplets, and the release of FFA gradually slows down.

[0084] Example 7 This example describes the effect of the described composite emulsion on improving insomnia.

[0085] Test subjects: Select subjects with at least 2 of the following characteristics: long sleep onset time, frequent awakenings, restless sleep, inability to fall asleep again after waking up, early morning awakening, and多梦 (excessive dreaming). The subjects are aged 17 - 65 years old, including 30 females and 30 males. They are randomly divided into an experimental group, a melatonin group, and a control group, with 10 males and 10 females in each group. The subjects in the experimental group take 10 mL of the composite emulsion provided by the present invention (melatonin content 0.02 wt%) once in the morning and once in the evening, after meals; the melatonin group takes melatonin (MCT containing 0.02 wt% melatonin), with the same dosage and administration method as the experimental group; the control group does not take any medicine, and the usage effects of each group are evaluated (the results are shown in Table 3).

[0086] Evaluation method: Using the self - control design method, use a smart watch to detect various sleep data, record and collect through sensors, and accurately analyze each stage of sleep, including deep sleep, core sleep, rapid eye movement sleep, and wakefulness time, so as to judge the time and proportion of each sleep stage occurring, and thus depict the sleep structure. Evaluation criteria: If the core sleep time increases by more than 10% or the wakefulness time decreases by more than 10%, it is considered significantly effective; if the core sleep time increases by 5 - 10% or the wakefulness time decreases by 5 - 10%, it is considered effective; if the core sleep time fluctuates within 5% or the wakefulness time fluctuates within 5%, it is considered ineffective.

[0087] Table 3. Effect of improving insomnia

[0088] From the data in Table 3, we know that the average core sleep duration in the experimental group increased by 40.8% compared with the control group and 21.05% compared with the melatonin group. The average wakefulness duration in the experimental group was shortened by 62.5% compared with the control group and 40% compared with the melatonin group. In addition, the number of significant and effective patients in the experimental group was 6 and 10, respectively, which was 3 and 2 more than that in the melatonin group, respectively, showing a significant improvement. The total effective rate increased by 25% compared with the melatonin group, with significant results.

[0089] The embodiments described above are only some embodiments of the present invention, not all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the present invention are within the scope of protection of the present invention.

Claims

1. A composite emulsion for improving insomnia, characterized in that: The components of the composite emulsion are: in terms of volume percentage, 70-95% of a modified fucoidan solution with a concentration of 0.5-3 mg / mL, and the remainder is a medium-chain triglyceride containing melatonin; The content of melatonin in the composite emulsion is 0.02wt%.

2. The composite emulsion according to claim 1, characterized in that The preparation method of the modified fucoidan is: Disperse fucoidan in pure water to prepare a 20wt% fucoidan solution, and adjust the pH of the fucoidan solution system to 8.5 with a 0.5mol / L NaOH solution; Add 3-9% octenyl succinic anhydride dilution and continue stirring the reaction at 45°C for 1 hour, during which the pH of the reaction solution is maintained at 8.5 with 0.5 mol / L NaOH solution; The reaction was terminated by adjusting the pH to 6.0 with 0.1 mol / L HCl solution; The reaction solution was dialyzed for 48 hours using a dialysis bag with a molecular weight cutoff of 3500Da, evaporated and concentrated to remove water, and then freeze-dried to obtain modified fucoidan; The octenyl succinic anhydride dilution is prepared by diluting octenyl succinic anhydride with 5 times the volume of anhydrous ethanol.

3. The method for preparing the composite emulsion according to claim 1, characterized in that: include: Dissolve the modified fucoidan in distilled water to prepare a modified fucoidan solution with a concentration of 0.5-3 mg / mL, heat to 85°C and maintain for 30 min, then cool to 50°C; Dissolving melatonin in medium-chain triglycerides so that the content of melatonin in the composite emulsion is 0.02 wt %, to obtain medium-chain triglycerides containing melatonin; The modified fucoidan solution is mixed with the medium chain triglyceride containing melatonin, and the mixing ratio is: in terms of volume percentage, the modified fucoidan solution is 70-95%, and the balance is the medium chain triglyceride containing melatonin; The mixture is homogenized in a shearing machine and then ultrasonically treated for 1 to 5 minutes to obtain the composite emulsion.

4. The preparation method according to claim 3, characterized in that: Homogenization conditions: 10000 rpm, 3 min.

5. The use of the composite emulsion according to claim 1, characterized in that: The composite emulsion is used for improving insomnia.

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