Diglyceride-based smearing water-out type emulsion gel as well as preparation method and application of diglyceride-based smearing water-out type emulsion gel

Abstract

The invention belongs to the field of cosmetics and food, and discloses a diglyceride-based smearing water-out type emulsion gel as well as a preparation method and application of the diglyceride-based smearing water-out type emulsion gel. According to the invention, the diglyceride-based solid micro-capsules are prepared firstly, and then the diglyceride-based solid micro-capsules, the vegetable oil and the water are dispersed, mixed and sheared to obtain the emulsion with a good water outlet effect, and the emulsion is small in particle size, and has good storage stability, a soft cream form and a plastic structure. In the smearing process of the emulsion, the cream is quickly melted, fine and dense water drops are released, no greasy and heavy skin feeling exists, quick moisturizing can be achieved, the cool skin feeling and the unique experience feeling are brought, and the multifunctional skin care cream or ointment can be prepared by adding other active substances, essence and the like.

Description

Technical Field

[0001] The invention belongs to the field of cosmetics and food, and particularly relates to a smearable water-dispensing emulsion gel based on diglyceride, and a preparation method and application thereof. Background Art

[0002] Oil-in-water emulsions are common in cosmetic creams and can easily form a protective film on the skin surface, exerting excellent moisturizing, water-resistant and repairing effects. Commonly used emulsifiers include Span 80, diisostearyl polyglyceryl-3 dimer linoleate, polyglyceryl-6 polyricinoleate, polyglyceryl-2 dipolyhydroxystearate, polydimethylsiloxane, etc. However, synthetic emulsifiers can cause adverse reactions such as skin sensitivity, hemolysis and cytotoxicity, and have poor biocompatibility and degradation ability, which can easily cause adverse effects on the environment. Therefore, in order to meet consumers' demand for safer and healthier products, the development of green, safe and highly biocompatible cosmetic emulsion systems has attracted much attention.

[0003] Water-forming emulsions are a type of emulsion that quickly dissolves and oozes water droplets when applied to the skin, also known as "bursting beads". They have a unique user experience and a refreshing skin feel. The internal phase usually contains more than 60% water by volume, which requires storage stability. When used, the emulsion membrane is destroyed and demulsification occurs. This type of product often requires a large amount of silicone oil synthetic emulsifiers and co-emulsifiers, or the addition of titanium dioxide, etc., to achieve the effect of emulsification stability and rapid water release when applied. A good balance between stability and demulsification is required. However, water-forming cream formulas generally have the problem of insufficient stability and easy demulsification during low-temperature storage.

[0004] The Chinese invention patent application publication (CN111346021A) discloses an oil-in-water emulsion water cream stabilized by neopentyl glycol diester and silicone liquid crystal silicon. Although it has strong anti-freezing and stabilizing effects, it requires the addition of a high content of synthetic emulsifier.

[0005] The Chinese invention patent application publication (CN114632031A) discloses a water-based cream with a milky texture, comprising titanium dioxide, an alcohol component and an oil phase component, wherein the oil phase component comprises polydimethylsiloxane, cyclopentasiloxane, etc., and the cream is in a liquid flow form.

[0006] The Chinese invention patent application publication (CN114259427A) discloses a water cream that melts and releases water as soon as it is applied and a preparation method thereof. The formula uses silicone oil components such as cyclopentasiloxane and polydimethylsiloxane.

[0007] Diacylceride is a natural component in oils and fats. It is a structural lipid formed by replacing a fatty acid residue in triglyceride with a hydroxyl group. Its unique crystallization characteristics and emulsification properties make the crystal particles have good stability in water-in-oil Pickering emulsions. However, there are no reports on water-injectable creams prepared with diacylglycerol. Summary of the invention

[0008] In order to overcome the shortcomings and deficiencies of the above-mentioned prior art and develop a greener and more environmentally friendly product with excellent water-discharging performance, the primary purpose of the present invention is to provide a method for preparing a diglycerol-based water-discharging emulsion gel. The diglycerol-based water-discharging emulsion gel provided by the present invention has good stability during storage, and the interface crystallization and network crystallization characteristics of the diglycerol solid microcapsules simultaneously play a role in stabilizing the water phase, and no additional surfactants and organic reagents are required during the preparation process.

[0009] Another object of the present invention is to provide a stable water-dispensable emulsion gel based on diglyceride solid microcapsules prepared by the above method.

[0010] Another object of the present invention is to provide an application of the above-mentioned diglyceride-based water-dispersible emulsion gel. The emulsion gel of the present invention has strong stability at room temperature, presents a semi-solid state, has good plasticity and spreadability, and quickly releases water after being spread on the skin without a greasy feeling. It is green and safe, and has a good skin feel.

[0011] The purpose of the present invention is achieved through the following solutions:

[0012] A method for preparing a diglyceride-based water-dispensable emulsion gel comprises the following steps:

[0013] (1) Preparation of diglyceride-based solid microcapsules: adding a macromolecular stabilizer to water, heating and stirring to fully dissolve it, and obtaining an aqueous phase; heating and melting diglyceride to form an oil phase; adding the oil phase to the aqueous phase and mixing to obtain a crude emulsion, and then subjecting the mixture to high-speed shearing to obtain a homogeneous emulsion; cooling and stratifying the mixture, collecting the upper suspended matter, and drying to obtain diglyceride-based solid microcapsules;

[0014] (2) Preparation of water-dispersed emulsion: adding solid microcapsules to vegetable oil and stirring to mix evenly to form an oil phase; adding water to the oil phase to obtain a crude emulsion, and high-speed shearing to obtain a water-dispersed emulsion stabilized by diglyceride-based solid microcapsules.

[0015] The macromolecular stabilizer described in step (1) is at least one of methylcellulose, gelatin, and hydroxypropyl methylcellulose; the mass fraction of the macromolecular stabilizer in the aqueous phase of step (1) is 0.1% to 1.5%; the heating and stirring in the process of obtaining the aqueous phase in step (1) is preferably stirred at 50-85° C. to ensure that the macromolecular stabilizer is fully dissolved in water and mixed evenly.

[0016] The diglyceride in step (1) has a melting point range of 40-70° C. and a purity of not less than 60%; the carbon atoms of the fatty acids contained in the diglyceride are relatively independent and are 12-18, and the corresponding two fatty acids in the diglyceride are one or two of lauric acid, myristic acid, palmitic acid or stearic acid.

[0017] Preferably, the diglyceride described in step (1) can be prepared by esterification reaction of fatty acids containing 12-18 carbon atoms and glycerol under the catalytic action of lipase, or by esterification of monoglycerides of fatty acids containing 12-18 carbon atoms and fatty acids containing 12-18 carbon atoms, or by esterification or transesterification of monoglycerides of fatty acids containing 12-18 carbon atoms and triglycerides containing 12-18 carbon atoms; wherein the fatty acid containing 12-18 carbon atoms is one or more of lauric acid, myristic acid, palmitic acid or stearic acid. The fatty acids and monoglycerides are removed by molecular distillation to obtain a crude product, and a diglyceride with a purity of not less than 60% is obtained.

[0018] Preferably, in step (1), the mass ratio of the oil phase to the water phase is 5:95-40:60.

[0019] Preferably, the step (1) of adding the oil phase to the water phase to obtain a crude emulsion means preheating the water phase to 50-85° C., adding the oil phase to the water phase, and mixing uniformly to obtain a crude emulsion, and the preparation process is maintained at 50-85° C. The addition is preferably dropwise addition, and the dropwise addition speed is preferably 5-10 mL / min.

[0020] Preferably, the high-speed shearing in step (1) refers to high-speed shearing the crude emulsion at 8000-12000 rpm for 3-6 min, with the shearing temperature maintained at 50-85° C. to obtain an oil-in-water emulsion.

[0021] Preferably, the cooling and stratification in step (1) refers to cooling at 0-4°C, preferably immediately placing the emulsion in an ice water bath for cooling, while using a stirrer to stir at a speed of 500-1000 rpm for 3-10 min, collecting the upper layer of the suspension and drying it in an oven to obtain diglyceride-based solid microcapsules.

[0022] According to the needs of producing products with different functions, the vegetable oil in step (2) is one or more vegetable oils well known to those skilled in the art, including at least one of olive oil, avocado oil, corn oil, wheat germ oil, shea butter, grape seed oil, jojoba seed oil, sunflower seed oil, etc.

[0023] The amounts of the solid microcapsules and the vegetable oil in step (2) satisfy: the mass fraction of the solid microcapsules in the oil phase of step (2) is 3-10%;

[0024] The mixing to form the oil phase in step (2) refers to mixing evenly at 25-65° C.; in order to fully disperse the solid microcapsules in the vegetable oil, the solid microcapsules are preferably ground before being added to the oil phase in step (2).

[0025] The water described in step (2) is preferably deionized water;

[0026] The mass ratio of the oil phase to water in step (2) is 75:25 to 40:60;

[0027] Preferably, when water is added to the oil phase in step (2), the oil phase needs to be preheated to 25-65° C., and the water is added to the stirred oil phase, and stirred and mixed to obtain a crude emulsion, and the temperature of the preparation process is maintained at about 25-65° C. The water is preferably added dropwise to the oil phase, and the dropping speed is 5-10 mL / min; the stirring and mixing is preferably stirred at 500-1000 rpm for 3-10 min to obtain the crude emulsion.

[0028] Preferably, the high-speed shearing in step (2) refers to high-speed shearing of the crude emulsion at 8000-12000 rpm for 3-6 min, with the shearing temperature maintained at about 25-65° C., to obtain the final water-in-oil type emulsion gel, which is then stored at 4 or 25° C.

[0029] A diglyceride-based water-dispensable emulsion gel prepared by the above method. Different types of preservatives, stabilizers, antioxidants, chelating agents, pH regulators, functional ingredients, flavors, essential oils, etc. can be added to the water-dispensable emulsion according to the product efficacy. The addition can be selected in step (1) or (2) of the present invention, and the added amount is not included in the water phase or the oil phase.

[0030] Water-in-oil emulsion is based on traditional water-in-oil skin care creams and is in a metastable state. The emulsified particles desorb during the shearing (i.e., smearing) process and demulsification occurs, thereby achieving the effect of rapid seepage of fine water droplets, creating a strong sense of water and hydrating the skin. The oil phase can form an oil film on the skin surface. At the same time, the water-in-oil emulsion also has the ability to encapsulate and protect water-soluble active ingredients, allowing the active ingredients to be quickly absorbed during hydration.

[0031] The smearable water-dispersible emulsion of the present invention is in a gel state, wherein the inner phase is a water phase and the outer phase is an oil phase. The diglycerol-based solid microcapsules are used as stabilizers, and the diglycerol microcapsules are prepared by utilizing safe macromolecular stabilizers. The preparation of the water-in-oil type water-dispersible emulsion with high storage stability is achieved through interface and network crystallization stabilization, and the limitations of using polydimethylsiloxane copolymer raw materials (silicone oil) and its derivatives, titanium dioxide and other synthetic substances are avoided. The smearable water-dispersible emulsion has a good water-dispersible effect, and fine and dense small water droplets are evenly exuded after being applied on the skin and spread.

[0032] Application of the above-mentioned diglyceride-based water-dispensable emulsion gel in cosmetics.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0034] (1) The raw materials used in the present invention are natural and safe, with strong physiological activity, and no need to add synthetic silicone oil, thickener and co-emulsifier. Glycerol diglyceride has excellent biological activity and skin permeability. The use of diglycerol microcapsules as stabilizers for oil-in-water emulsion gels solves the irritation and allergy problems caused by the use of a large amount of synthetic emulsifiers in the past oil-in-water emulsion gels.

[0035] (2) The present invention prepares diglyceride-based solid microcapsules first, and then disperses, mixes and shears with vegetable oil and water to obtain an emulsion with good water-release effect. The emulsion has a small particle size, good storage stability, soft cream form and plastic texture. The emulsion can quickly penetrate water during application, without a greasy and heavy skin feel. After being applied to the skin and pushed open, fine and dense small water droplets are evenly exuded, which can achieve rapid hydration and bring a unique experience. Other active substances, flavors, etc. can be added to prepare multifunctional skin care creams or ointments.

[0036] (3) The preparation process of the emulsion gel of the present invention is simple, does not require large-scale equipment, is low-cost, environmentally friendly and pollution-free, and does not require overly complicated processes, making it easy to expand production; it can not only serve as an excellent carrier to achieve rapid hydration of the skin, but also serve as a carrier of water-soluble active substances to achieve moisturizing while exerting the efficacy of the active substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the process of the present invention.

[0038] Figure 2 This is an optical microscope image of the diglyceride-based solid microcapsules prepared in Example 1.

[0039] Figure 3 The appearance, microstructure and particle size distribution of the water-spreading emulsion gel prepared in Example 1.

[0040] Figure 4 This is a diagram showing the appearance changes of the emulsion gel of Example 1 after being placed at different temperatures for one month.

[0041] Figure 5 This is the rheological property of the emulsion gel in Example 1.

[0042] Figure 6 This is a picture showing the water-release effect of applying the water-release emulsion gel of Example 1 on the skin surface.

[0043] Figure 7This is the appearance, microstructure and particle size distribution of the emulsion gel prepared in Example 2.

[0044] Figure 8 This is a picture showing the water-release effect of applying the water-release emulsion gel of Example 2 on the skin surface.

[0045] Fig. 9 This is the appearance, microstructure and particle size distribution of the emulsion gel prepared in Example 3.

[0046] Fig.10 This is a picture showing the water-release effect of applying the water-release emulsion gel of Example 3 on the skin surface.

[0047] Fig.11 This is the appearance, microstructure and particle size distribution of the emulsion gel prepared in Example 4.

[0048] Fig.12 This is a picture showing the water-release effect of applying the water-release emulsion gel of Example 4 on the skin surface.

[0049] Fig.13 This is the appearance, microstructure and particle size distribution of the emulsion gel prepared in Comparative Example 1.

[0050] Fig.14 This is a picture showing the effect of applying the water-release emulsion gel of Comparative Example 1 on the skin surface.

[0051] Fig.15 Appearance of the emulsion gel prepared in Comparative Example 2

[0052] Fig.16 This is a picture showing the effect of applying the water-release emulsion gel of Comparative Example 2 on the skin surface.

[0053] Fig.17 This is the appearance of the emulsion gel prepared in Comparative Example 3.

[0054] Fig.18 This is a picture showing the effect of applying the water-release emulsion gel of Comparative Example 3 on the skin surface.

[0055] Fig.19 This is the appearance of the emulsion gel prepared in Comparative Example 4.

[0056] Fig. 20 This is a picture of the effect of the emulsion gel prepared in Comparative Example 4 after being applied on the skin surface.

[0057] Fig.21 This is the appearance of the emulsion prepared in Comparative Example 5.

[0058] Fig. 22 This is a picture showing the effect of applying the water-release emulsion of Comparative Example 5 on the skin surface. DETAILED DESCRIPTION

[0059] The present invention is further described in detail below in conjunction with the examples and drawings, but the embodiments of the present invention are not limited thereto. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0060] The diglycerides in the embodiments of the present invention can be prepared by existing technical methods, such as the method of esterification of fatty acids with glycerol or monoglycerides (Enzymatic preparation and facile purification of medium-chain, and medium-and long-chain fatty acid diacylglycerols [J]. LWT-Food Science and Technology, 2018, 92, 227-233), or prepared by the method of ester exchange between monoglycerides and triglycerides, and purified by molecular distillation to obtain diglycerides with a purity of 60 to 80%, but the preparation of diglycerides is not limited to the above methods.

[0061] Example 1

[0062] (1) Stearic acid diglyceride with a purity of 60% was placed in a beaker and fully dissolved at 75°C to form an oil phase. Methyl cellulose (viscosity 1500 mPa·s) was dissolved in water to form an aqueous phase, wherein the methyl cellulose accounted for 0.1% of the aqueous phase by mass. The oil phase preheated to 75°C was mixed with the aqueous phase (the mass ratio of the oil phase to the aqueous phase was 10:90), and high-speed shearing was performed at 10,000 rpm for 3 minutes, and then immediately placed in an ice water bath at 4°C, stirred and cooled at 800 rpm for 30 minutes, and the upper suspended matter was collected and dried to obtain diglyceride-based solid microcapsules.

[0063] (2) The diglyceride-based solid microcapsules obtained in step (1) are dispersed in olive oil at 45°C to form an oil phase (the mass ratio of the solid microcapsules to the olive oil is 5:95), and water preheated to the same temperature is added to the oil phase and stirred to obtain a crude emulsion, wherein the mass ratio of the oil phase to water is 40:60, and a water-in-oil emulsion gel is formed by high-speed shearing at 10,000 rpm for 3 min, which is then stored at 25°C.

[0064] Through optical microscope observation, the diglyceride-based solid microcapsules were successfully prepared in step (1), and further through staining and optical microscope observation, the emulsion gel prepared by further mixing the solid microcapsules of Example 1 with oil and water was an oil-in-water type. Figure 2 As shown in Figure 2, the appearance and microstructure of the emulsion gel are as follows: Figure 3 shown.

[0065] The emulsion gel in the embodiment has a white cream texture and does not delaminate when placed in a temperature range of 4°C to 45°C for one month ( Figure 4 ), no water or oil seepage, the particle size distribution of the emulsion was analyzed by Nano Measure 2.1, and the average particle size was 7 μm. The elastic modulus and viscous modulus of the emulsion gel during amplitude scanning were measured using a rheometer, and the results showed that the elastic modulus (G') of the emulsion gel was 1.24×10 4 Pa. G' is greater than the viscous modulus (G") ( Figure 5 ), indicating that the emulsion gel exhibits the characteristics of an elastic semi-solid gel, has good plasticity, and can quickly and evenly exude fine and uniform water droplets after being applied on the skin surface ( Figure 6 ).

[0066] Example 2

[0067] (1) Referring to the steps and conditions in Example 1, the difference is that the fatty acid composition of the diglyceride in step (1) is palmitic acid with a purity of 65%, methylcellulose (viscosity 1500 mPa·s) is dissolved in water to form an aqueous phase, wherein the mass ratio of methylcellulose in the aqueous phase is 0.1%. Then, the oil phase preheated to 75° C. is mixed with the aqueous phase (the mass ratio of the oil phase to the aqueous phase is 40:60), and high-speed shearing is performed at 10000 rpm for 3 min to form an emulsion, which is then immediately placed in an ice-water bath at 4° C., stirred and cooled at 800 rpm for 30 min, and the upper suspended matter is collected and dried to obtain diglyceride-based solid microcapsules.

[0068] (2) The prepared solid microcapsules were dispersed in sunflower oil at 45°C to form an oil phase (the mass ratio of the solid microcapsules to the sunflower oil was 5:95), water preheated to 45°C was dripped into the oil phase at a dripping speed of 5-10 mL / min (the mass ratio of the oil phase to water was 40:60), and the mixture was stirred to obtain a crude emulsion, which was then sheared at 12000 rpm for 3 min to form an oil-in-water emulsion, and the prepared emulsion was stored at 25°C.

[0069] The appearance, microstructure and particle size distribution of the aqueous emulsion gel smeared in Example 2 are as follows: Figure 7 As shown, the average particle size of the emulsion is 25 μm and the elastic modulus G' is 2.43×10 3 Pa. Stable at room temperature, no obvious change in appearance after 2 months. Good water release effect, fine and uniform water droplets can be quickly and evenly exuded after application ( Figure 8 ).

[0070] Example 3

[0071] (1) Referring to the steps and conditions in Example 1, the difference is that in step (1), the oil phase is a medium-chain diglyceride containing long-chain stearic acid and medium-chain lauric acid, and the diglyceride purity is 70%; methylcellulose (viscosity 1500 mPa·s) is dissolved in water to form an aqueous phase, and the mass ratio of methylcellulose to the aqueous phase is 0.1%; the oil phase preheated to 75° C. is mixed with the aqueous phase (the mass ratio of the oil phase to the aqueous phase is 10:90), and high-speed shearing is performed at 10,000 rpm for 3 min to form an emulsion, and then the emulsion is immediately placed in an ice water bath at 4° C., stirred and cooled at 800 rpm for 30 min, and the upper suspended matter is collected, dried and ground to obtain diglyceride-based solid microcapsules.

[0072] (2) The solid microcapsules were dispersed in corn oil at 45°C to form an oil phase (the mass ratio of the solid microcapsules to the corn oil was 5:95), and water, which was also preheated to 45°C, was dripped into the oil phase at a dripping speed of 5-10 mL / min (the mass ratio of the oil phase to the water phase was 40:60), and the mixture was stirred to obtain a crude emulsion, which was then sheared at 10,000 rpm on a high-speed shearing machine for 3 min to prepare an oil-in-water emulsion gel.

[0073] (3) The appearance, microstructure and particle size distribution of the emulsion gel prepared in Example 3 are as follows: Fig. 9 As shown in Figure 2, the emulsion has good standing performance and the elastic modulus G' is 1.96×10 3 Pa. After being placed at room temperature for 2 months, the appearance and particle size have no obvious changes. It has good plasticity and gel properties, and has a good water-release effect when applied. After application, fine and uniform water droplets can be quickly and evenly exuded ( Fig.10 ).

[0074] Example 4

[0075] (1) Referring to the steps and conditions in Example 1, the difference is that the stabilizer in step (1) is gelatin (Shanghai Yuanye Biotechnology Co., Ltd., product number: S30952), wherein the content of gelatin accounts for 1.2 wt% of the content of the aqueous phase; the gelatin is fully dissolved in water at 75°C to form an aqueous phase, stearic acid diglycerol is melted at 75°C to form an oil phase, the aqueous phase and the oil phase (the mass ratio of the oil phase to the aqueous phase is 10:90) are mixed and sheared at 12000 rpm for 3 min, and then quickly placed in an ice water bath at 4°C, stirred and cooled at 800 rpm for 30 min, and the upper suspended matter is collected, dried and ground to obtain diglyceride-based solid microcapsules.

[0076] (2) The solid microcapsules were dispersed in sunflower oil at 45°C to form an oil phase (the mass ratio of the solid microcapsules to the sunflower oil was 5:95), and water, which was also preheated to 45°C, was slowly dripped into the oil phase at a dripping rate of 5-10 mL / min (the mass ratio of the oil phase to the water phase was 40:60), and the mixture was stirred to obtain a crude emulsion, which was then sheared at 10,000 rpm on a high-speed shearing machine for 3 min to prepare an emulsion gel.

[0077] The appearance, microstructure and particle size distribution of the emulsion gel prepared in Example 4 are shown in FIG. Fig.11 As shown in Figure 4, the water-in-oil emulsion prepared in Example 4 has good standing performance, and the elastic modulus G' is 9.44×10 2 Pa. The emulsion has no obvious change in appearance after being placed at room temperature for 2 months, and the water-release effect is good ( Fig.12 ).

[0078] Comparative Example 1

[0079] The steps and conditions of Example 1 are similar, except that no methylcellulose is added to the aqueous phase during the preparation of the solid microcapsules in step (1), but methylcellulose is added to the aqueous phase in step (2).

[0080] (1) Stearic acid diglyceride with a purity of 60% was placed in a beaker and fully melted at 75°C to form an oil phase. The oil phase preheated to 75°C was mixed with deionized water (the mass ratio of the oil phase to the water phase was 10:90), and high-speed shearing was performed at 10,000 rpm for 3 min. The mixture was then immediately placed in an ice water bath at 4°C, stirred and cooled at 800 rpm for 30 min, and the upper suspended matter was collected, dried and ground to obtain diglyceride-based solid microcapsules.

[0081] (2) The diglyceride-based solid microcapsules obtained in step (1) are dispersed in olive oil at 45° C. to form an oil phase (wherein the mass ratio of microcapsules to oil is 5:95), and an aqueous phase preheated to the same temperature and containing 0.3 wt % methyl cellulose is dripped into the oil phase at a dripping speed of 5-10 mL / min and mixed evenly to form a crude emulsion, wherein the mass ratio of the oil phase to the aqueous phase is 40:60, and an emulsion is formed by high-speed shearing at 10,000 rpm for 3 min. The appearance of the emulsion is as follows: Fig.13 As shown, the emulsion has poor plasticity and cannot stand up well. There is no water discharge when the emulsion is applied ( Fig.14 ).

[0082] Comparative Example 2

[0083] The steps and conditions of Example 1 are as follows, except that no methyl cellulose is added to the aqueous phase during the preparation of the solid microcapsules in step (1) and no methyl cellulose is added to the aqueous phase in step (2).

[0084] (1) Stearic acid diglyceride with a purity of 60% was placed in a beaker and fully melted at 75°C to form an oil phase. The oil phase preheated to 75°C was mixed with deionized water (the mass ratio of the oil phase to the water phase was 10:90), and high-speed shearing was performed at 10,000 rpm for 3 min. The mixture was then immediately placed in an ice water bath at 4°C, stirred and cooled at 800 rpm for 30 min, and the upper suspended matter was collected, dried and ground to obtain diglyceride-based solid microcapsules.

[0085] (2) dispersing the particles in step (1) in sunflower oil to form an oil phase, wherein the particle content accounts for 5% of the mass ratio of the oil phase; preheating water to 45° C. to form an aqueous phase, adding the aqueous phase to the oil phase at a mass ratio of the oil phase to the aqueous phase of 40:60, and shearing with a high-speed shearing machine at 10,000 rpm for 3 minutes to form an oil-in-water emulsion.

[0086] The appearance of the emulsion prepared in Comparative Example 2 is as follows Fig.15 As shown in the figure, water precipitation occurs after shearing by the high-speed shearing machine. This shows that the particles prepared by shearing with stearic acid diglycerol solid microcapsules alone cannot stabilize the oil-in-water emulsion with a moisture content of 60%. The emulsion is unstable and has water precipitation, and no uniform water droplets appear when applied ( Fig.16 ).

[0087] Comparative Example 3

[0088] (1) Stearic acid diglycerol with a purity of 60% is directly mixed with a certain mass of rapeseed oil at 85° C. to obtain an oil phase, wherein the mass ratio of diglycerol to the total oil phase is 8%, and the mass ratio of the oil phase to deionized water is 40:60. The deionized water and the oil phase are fully mixed at 1000 rpm for 8 minutes to obtain a crude emulsion with a water phase mass percentage of 60%.

[0089] (2) The crude emulsion obtained in step (1) was sheared and homogenized at a high-speed shearing machine at a speed of 15000 rpm for 5 minutes, and the system temperature was maintained at about 85° C. during the shearing process. The obtained emulsion was then stirred and cooled at 800 rpm for 30 minutes in an ice water bath at 4° C. to obtain a W / O emulsion, and the emulsion was stored at 4° C.

[0090] The diglyceride crystal-stabilized water-in-oil emulsion obtained in Comparative Example 3 has good standing performance ( Fig.17 ), after being placed at 4°C for 90 days, the appearance and particle size did not change significantly, indicating that the emulsion system is highly stable. However, it can only be spread evenly on the skin surface, with the texture of ordinary cream, and no water leakage ( Fig.18 ).

[0091] Comparative Example 4

[0092] (1) Medium-chain diglycerides containing lauric acid and stearic acid are heated to 80° C. until completely melted to obtain an oil phase; water preheated to the same temperature is added to the oil phase, heated and stirred to obtain a diglyceride mixed solution, the mixed solution is high-speed sheared at 10,000 rpm for 3 min, and then ultrasonicated at 80° C. and 480 W for 5 min to obtain a diglyceride dispersion, and stirred and cooled in an ice-water bath at 4° C. to obtain a diglyceride solid lipid nanoparticle dispersion (wherein the diglyceride content is 3.33%).

[0093] (2) The diglyceride solid lipid nanoparticle dispersion obtained in step (1) is added to soybean oil as an aqueous phase, and high-speed shearing is performed at 10,000 rpm for 3 minutes to obtain an oil-in-water emulsion gel with a mass ratio of oil phase to aqueous phase of 40:60.

[0094] Comparative Example 4: Solid lipid nanoparticles prepared by medium- and long-chain diglycerides, and the water-in-oil emulsion gel prepared thereafter has good plasticity and stability ( Fig.19 ), but the lotion has a normal gel texture and does not produce water when applied ( Fig. 20 ).

[0095] Comparative Example 5

[0096] Accurately weigh polyglycerol polyricinoleate (PGPR) and dissolve it in sunflower oil to form an oil phase. The final concentration of polyglycerol polyricinoleate is adjusted to 1wt% of the oil phase. Deionized water is used as the water phase. The water phase is dropped into the oil phase at a drop rate of 5-10mL / min at 45°C (the mass ratio of the oil phase to the water phase is 40:60), and sheared at 10000rpm for 3min by a high-speed shearing machine to obtain an oil-in-water emulsion.

[0097] In Comparative Example 5, a conventional nonionic emulsifier, polyglycerol ricinoleate, was used to prepare a water-in-oil emulsion. The emulsion formed was not gel-like but fluid ( Fig.21 ), the lotion cannot be applied without water ( Fig. 22 ).

[0098] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a diglyceride-based water-dispensing emulsion gel, characterized in that The following steps are involved: (1) Preparation of diglyceride-based solid microcapsules: adding a macromolecular stabilizer to water, heating and stirring to fully dissolve it, and obtaining an aqueous phase; heating and melting diglyceride to form an oil phase; adding the oil phase to the aqueous phase and mixing to obtain a crude emulsion, and then high-speed shearing to obtain a mixed emulsion; Cool and separate the mixture, collect the upper suspended matter, and dry it to obtain diglyceride-based solid microcapsules; (2) Preparation of water-dispersed emulsion: adding solid microcapsules to vegetable oil and stirring to mix evenly to form an oil phase; adding water to the oil phase to obtain a crude emulsion, and high-speed shearing to obtain a water-dispersed emulsion stabilized by diglyceride-based solid microcapsules.

2. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: The macromolecular stabilizer described in step (1) is at least one of methyl cellulose, gelatin, and hydroxypropyl methyl cellulose.

3. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: The melting point of the diglyceride in step (1) is in the range of 40-70° C., and the purity is not less than 60%; the carbon atoms of the fatty acids contained in the diglyceride are relatively independent and are 12-18.

4. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: The mass fraction of the macromolecular stabilizer in the aqueous phase of step (1) is 0.1% to 1.5%; the heating and stirring in the process of obtaining the aqueous phase in step (1) refers to stirring at 50-85°C; In step (1), the mass ratio of the oil phase to the water phase is 5:95-40:60; The step (1) of adding the oil phase to the water phase and mixing to obtain a crude emulsion means preheating the water phase to 50-85° C., adding the oil phase to the water phase, and mixing uniformly to obtain a crude emulsion, and maintaining the temperature at 50-85° C. during the preparation process; The high-speed shearing in step (1) refers to high-speed shearing the crude emulsion at 8000-12000 rpm for 3-6 minutes, with the shearing temperature maintained at 50-85° C. to obtain an oil-in-water emulsion; The cooling and stratification described in step (1) refers to cooling at 0-4°C.

5. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: The vegetable oil in step (2) is at least one of olive oil, avocado oil, corn oil, wheat germ oil, shea butter, grape seed oil, jojoba seed oil and sunflower seed oil.

6. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: The amounts of the solid microcapsules and the vegetable oil in step (2) satisfy: the mass fraction of the solid microcapsules in the oil phase of step (2) is 3-10%; The mass ratio of the oil phase to water in step (2) is 75:25 to 40:

60.

7. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: When adding water to the oil phase in step (2), the oil phase needs to be preheated to 25-65° C., and the water is added to the stirred oil phase, and stirred to obtain a crude emulsion. The temperature during the preparation process is maintained at about 25-65° C.; The high-speed shearing described in step (2) refers to the high-speed shearing of the crude emulsion at 8000-12000 rpm for 3-6 minutes, with the shearing temperature maintained at 25-65° C., to obtain the final water-in-oil type emulsion gel.

8. The method for preparing the diglyceride-based water-dispensable emulsion gel according to claim 1, characterized in that: The obtained spreadable water-type emulsion gel also contains at least one of a preservative, a stabilizer, an antioxidant, a chelating agent, a pH regulator, an effective ingredient, a flavor, and an essential oil, which is added in step (1) or step (2).

9. A diglyceride-based water-dispensable emulsion gel prepared according to the method of any one of claims 1 to 8.

10. Use of the diglyceride-based water-dispensable emulsion gel according to claim 9 in cosmetics.

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