阅读说明：本技术 一种界面结晶稳定的油凝胶基乳液及其制备方法和应用 (Stable-interfacial-crystallization oil gel-based emulsion and preparation method and application thereof ) 是由 兰雅淇 廖紫莹 张静 胡冰洁 于 2021-08-03 设计创作，主要内容包括：本发明属于乳液加工技术领域,提供了一种由界面结晶稳定的油凝胶基乳液及其制备方法和应用。本发明油凝胶分散相由凝胶剂和液体油组成,水连续相由两亲性的功能性脂质和水组成,将油凝胶分散相与水连续相混合通过均质乳化制成油水界面附着凝胶剂晶体的水包油凝胶型乳液,具有两亲性的功能性脂质与凝胶剂相互作用从而诱导不具备界面活性的凝胶剂晶体锚定在油水界面,形成类固体的刚性界面膜,以界面结晶来稳定油凝胶基乳液,增强了油凝胶基乳液的储藏稳定性,拓宽了油凝胶基乳液在食品、化妆品等各领域的应用。(The invention belongs to the technical field of emulsion processing, and provides an oil gel-based emulsion with stable interfacial crystallization, and a preparation method and application thereof. The oil gel dispersed phase of the invention is composed of gelata and liquid oil, the water continuous phase is composed of amphipathic functional lipid and water, the oil gel dispersed phase and the water continuous phase are mixed and homogenized and emulsified to prepare the oil-in-water gel type emulsion with gel crystals attached to an oil-water interface, the amphipathic functional lipid and the gelata interact to induce the gel crystals without interfacial activity to be anchored at the oil-water interface to form a solid-like rigid interfacial film, and the interface crystallization is used for stabilizing the oil gel base emulsion, thereby enhancing the storage stability of the oil gel base emulsion and widening the application of the oil gel base emulsion in various fields of food, cosmetics and the like.)

1. An oleogel-based emulsion stabilized by interfacial crystallization, said oleogel-based emulsion comprising an oleogel dispersed phase and a water continuous phase; mixing the oil gel dispersion phase with the water continuous phase, and preparing an oil-in-water gel type emulsion with gel crystals attached to an oil-water interface through homogeneous emulsification;

wherein the oleogel dispersed phase is comprised of a gelling agent and a liquid oil;

the aqueous continuous phase is composed of amphiphilic functional lipid and water;

the gel is one or more of beeswax, rice bran wax, ceramide, sitosterol, oryzanol, palmitic acid and ethyl cellulose;

the amphiphilic functional lipid is one or more of monoglyceride, diglyceride, lecithin, sphingomyelin, ethylene glycol monostearate, cholesterol and glycosphingolipid;

the liquid oil is one or more of sunflower seed oil, soybean oil, rice bran oil, corn oil, fish oil, olive oil, glycerol, grape seed oil and peanut oil.

2. The oleogel-based emulsion stabilized by interfacial crystallization of claim 1, wherein the weight ratio of the oleogel dispersed phase to the aqueous continuous phase is 1: 9-6: 4.

3. the oil gel-based emulsion stabilized by interfacial crystallization of claim 1, wherein the concentration of the gel agent in the dispersed phase of the oil gel is 0.1% w/w to 10% w/w.

4. The oleogel-based emulsion stabilized by interfacial crystallization of claim 1, wherein the concentration of amphiphilic functional lipid in the aqueous continuous phase is 0.1% w/w to 8% w/w.

5. The method of claim 1, comprising the steps of:

s1, mixing the liquid oil and the gel, heating and stirring until the gel is dissolved to obtain an oleogel dispersion phase;

s2, adding the amphiphilic functional lipid into water, and uniformly stirring to obtain a water continuous phase;

s3, homogenizing and emulsifying the oil gel dispersed phase and the water continuous phase prepared in the steps S1 and S2 to prepare the oil-in-water gel type emulsion.

6. The method of claim 5, wherein the step S3 of homogenizing and emulsifying is high shear, ultrasonic, high pressure homogenizing.

7. The interfacially crystallization stable oil gel-based emulsion prepared by the process of claim 5.

8. Use of the oleogel-based emulsion of claim 7 in the preparation of an emulsion product.

9. Use according to claim 8, wherein said emulsion products include, but are not limited to, food products, cosmetics.

Technical Field

The invention belongs to the technical field of emulsion processing, and particularly relates to an oil gel-based emulsion with stable interfacial crystallization, and a preparation method and application thereof.

Background

The emulsion is widely applied to the fields of food, cosmetics, pharmacy, coating, agriculture and the like. In food systems, emulsions are used as carriers for nutrients, bioactives, and flavor compounds, and exhibit superior performance in terms of protection, controlled release, and site-specific targeted delivery of bioactive ingredients. Emulsions are also one of the most important dosage forms in cosmetics, especially in skin care and make-up products, for improving or enhancing product function, odor, skin feel, and other qualities such as shelf life, viscosity, etc. The emulsion is primarily characterized by the presence of a large interfacial area, which is also an important factor in its thermodynamic instability. In order to improve the stability of emulsions, many conventional surface-active compounds, such as surfactants and proteins, are used to cover the oil-water interface and stabilize the emulsion. However, the nonionic surfactant cannot prevent the occurrence of flocculation due to insufficient electrostatic repulsive force of the droplets; proteins are sensitive to environmental conditions such as temperature, pH, ionic concentration, etc. The instability problems of the traditional emulsion, such as coalescence, flocculation and the like, caused by the gravity action of liquid drops or collision among liquid drops in the storage process are not enough to meet the requirement of people on the emulsion which is stable for a long time.

Present studies indicate that oleogel technology can improve emulsion stability to some extent. For example, patent CN110215416A discloses a camellia oil gel emulsion and a preparation method thereof, which utilizes an oil gel technology to add a gel agent into a dispersed phase, under the condition of heating, shearing and homogenizing to uniformly mix liquid camellia oil gel with water and an emulsifier, and during the cooling process, camellia oil droplets are crystallized or self-assembled to obtain an emulsion with better stability. The crystallization can prevent the flow of lipophilic liquid and the consumption of bioactive substances in the storage process, and the oil gel technology is utilized to adjust and transform the traditional emulsion so as to adapt to the application requirements of different products and meet the requirements of people on low heat, new performance and new structure of the products.

Further studies have shown that rigid interfacial films with viscoelastic properties can improve the long-term stability of emulsions, however most gelling agents do not have interfacial activity and thus cannot adhere to the oil-water interface, which greatly limits the use of oil gel-based emulsions in improving emulsion stability. Therefore, it is desired to devise a method for forming a rigid interfacial film by attaching a gelling agent to an oil-water interface, thereby improving the long-term stability of an oil gel-based emulsion, and to apply the method to the fields of food, cosmetics, and the like.

Disclosure of Invention

The primary object of the present invention is to provide an oleogel-based emulsion with stable interfacial crystallization.

In order to achieve the purpose, the invention provides the following technical scheme:

the present invention provides an oleogel-based emulsion stabilized by interfacial crystallization, the oleogel-based emulsion comprising an oleogel dispersed phase and a water continuous phase; mixing the oil gel dispersion phase with the water continuous phase, and preparing an oil-in-water gel type emulsion with gel crystals attached to an oil-water interface through homogeneous emulsification;

wherein the oleogel dispersed phase is comprised of a gelling agent and a liquid oil;

the aqueous continuous phase is composed of amphiphilic functional lipids and water.

Preferably, the weight ratio of the oleogel dispersed phase to the aqueous continuous phase is 1: 9-6: 4.

more preferably, the weight ratio of the oleogel dispersed phase to the aqueous continuous phase is 1: 9-2: 8.

preferably, the gel is one or more of beeswax, rice bran wax, ceramide, sitosterol, oryzanol, palmitic acid and ethyl cellulose.

Preferably, the amphiphilic functional lipid is one or more of monoglyceride, diglyceride, lecithin, sphingomyelin, ethylene glycol monostearate, cholesterol and glycosphingolipid.

The liquid oil is not particularly limited, and can meet relevant requirements of various industries. The liquid oil is one or more of sunflower seed oil, soybean oil, rice bran oil, corn oil, fish oil, olive oil, glycerol, grape seed oil and peanut oil.

Preferably, the concentration of the gelling agent in the dispersed phase of the oleogel is between 0.1% w/w and 10% w/w.

More preferably, the concentration of the gelling agent in the dispersed phase of the oleogel is between 1% w/w and 5% w/w.

Preferably, the concentration of the amphiphilic functional lipid in the aqueous continuous phase is between 0.1% w/w and 8% w/w.

More preferably, the concentration of the amphiphilic functional lipid in the aqueous continuous phase is between 1% w/w and 5% w/w.

In the preparation process of the stable-interface-crystallization hydrogel-based emulsion, the amphiphilic functional lipid interacts with the gelling agent to induce the gelling agent crystals without interface activity to be anchored at an oil-water interface, and finally a rigid interface film is formed, so that the storage stability of the hydrogel-based emulsion is improved.

The invention also provides a preparation method of the oil gel-based emulsion with stable interfacial crystallization.

In order to achieve the purpose, the invention provides the following technical scheme:

a method of preparing an oleogel-based emulsion stabilized by interfacial crystallization comprising the steps of:

s1, mixing the liquid oil and the gel, heating and stirring until the gel is dissolved to obtain an oleogel dispersion phase;

s2, adding the amphiphilic functional lipid into water, and uniformly stirring to obtain a water continuous phase;

s3, homogenizing and emulsifying the oil gel dispersed phase and the water continuous phase prepared in the steps S1 and S2 to prepare the oil-in-water gel type emulsion.

Preferably, in step S3, the homogenizing and emulsifying method is high-speed shearing, ultrasonic, high-pressure homogenizing.

Preferably, the particle size of the oil gel-based emulsion stabilized by interfacial crystallization is 0.5-10 microns.

More preferably, the particle size of the oleogel-based emulsion stabilized by interfacial crystallization is 1 to 5 microns.

The rigid interface film formed by the oil gel-based emulsion with stable interface crystallization, which is prepared by the invention, solves the instability problem caused by the aggregation of liquid drops generated by the mutual collision of the liquid drops and the gravity action of the liquid drops in the storage process of the traditional emulsion, keeps the whole grain diameter unchanged in the storage process, and achieves the effect of improving the stability of the emulsion.

It is another object of the present invention to provide the use of the above-described oleogel-based emulsion stabilized by interfacial crystallization for the preparation of emulsion products.

Substances adopted in the prepared oil gel-based emulsion are all food-grade substances, can be used as a base material of cosmetics, and broadens the application of the oil gel-based emulsion in preparing emulsion products, including but not limited to the fields of foods and cosmetics.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention provides an oleogel-based emulsion system with stable interfacial crystallization, which is characterized in that amphiphilic functional lipid interacts with a gelling agent to induce the gelling agent crystal without interfacial activity to be anchored at an oil-water interface, and finally a rigid interfacial film is formed at the oil-water interface, so that liquid drops generated by the mutual collision of the liquid drops and the action of the gravity of the liquid drops in the storage process of the emulsion are prevented from being aggregated, the long-term physical stability of the oleogel-based emulsion is enhanced, and the coalescence and the austenite ripening are prevented.

(2) The oil-water interface in the oil gel-based emulsion system is stabilized by the crystal particles of the oil gel agent, and the oil gel-based emulsion system is different from the Pickering emulsion stabilized by macromolecules such as protein, polysaccharide and the like, and can reduce emulsion instability caused by environmental factors such as temperature, pH, ions and the like, thereby enhancing the stability of the oil gel-based emulsion in the storage or processing process.

(3) Substances adopted in the oil gel-based emulsion system prepared by the invention are all food grade, can be used as a base material of cosmetics, and broadens the application of the oil gel-based emulsion in the fields of food, cosmetics and the like.

Drawings

FIG. 1 is a graph showing the results of interfacial rheology in examples 1 to 3 and comparative examples 1 to 2.

FIG. 2 is a micrograph of emulsions prepared in example 2 and comparative examples 1 to 2 (the first line is a bright field diagram of the emulsion and the second line is a polarized diagram of the emulsion).

FIG. 3 is a graph showing the results of the particle size of the emulsions prepared in examples 1 to 3 and comparative examples 1 to 2 immediately after 14 days of preparation and storage.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The test methods used in the experimental examples of the present invention are all conventional methods unless otherwise specified; the materials, reagents and the like used are, unless otherwise specified, commercially available reagents and materials.

In the following experimental examples:

the lecithin is soybean lecithin, the molar mass is 758.1g/mol, and the purity is more than 70%;

the ceramide is C18 ceramide III, the molar mass is 584g/mol, and the purity is more than 92%;

monoglyceride refers to glyceryl monostearate; diglyceride refers to distearic acid glyceric acid.

Example 1

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 4g sunflower seed oil and 0.04g ceramide, magnetically stirring at 120 deg.C and 900rpm for 30min, and standing for a while to obtain condensed oleogel dispersed phase;

(2) adding 0.5g lecithin into 16g water, and magnetically stirring at 500rpm at 75 deg.C for 30min to form water continuous phase;

(3) and adding the oil gel dispersion phase into the water continuous phase, and performing ultrasonic treatment for 2 minutes under the ultrasonic power of 400W to obtain the oil gel-based emulsion.

Example 2

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 4g of sunflower seed oil and 0.08g of ceramide, magnetically stirring at 900rpm for 45min at 120 ℃, and standing for a period of time to obtain a condensed oil gel dispersed phase;

(2) adding 0.5g lecithin into 16g water, and magnetically stirring at 500rpm at 75 deg.C for 30min to form water continuous phase;

(3) and adding the oil gel dispersion phase into the water continuous phase, and performing ultrasonic treatment for 2 minutes under the ultrasonic power of 400W to obtain the oil gel-based emulsion.

Example 3

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 4g sunflower seed oil and 0.12g ceramide, magnetically stirring at 120 deg.C and 900rpm for 45min, and standing for a while to obtain oil gel dispersed phase in condensed state;

(2) adding 0.5g lecithin into 16g water, and magnetically stirring at 500rpm at 75 deg.C for 30min to form water continuous phase;

(3) and adding the oil gel dispersion phase into the water continuous phase, and performing ultrasonic treatment for 2 minutes under the ultrasonic power of 400W to obtain the oil gel-based emulsion.

Example 4

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 1g sunflower seed oil and 0.04g beeswax, magnetically stirring at 90 deg.C and 900rpm for 45min, and standing for a while to obtain condensed oleogel dispersed phase;

(2) adding 1g monoglyceride into 15g water, magnetically stirring at 500rpm at 70 deg.C for 30min to dissolve, and standing to room temperature to form water continuous phase;

(3) and adding the water continuous phase into the oil gel dispersed phase in a condensation state, and homogenizing and emulsifying for 3 minutes at a shear rate of 10000rpm to obtain the oil gel-based emulsion.

Example 5

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 4g sunflower seed oil and 0.04g beeswax, and magnetically stirring at 90 deg.C and 900rpm for 45min to obtain molten oleogel dispersed phase;

(2) adding 1g monoglyceride into 16g water, and magnetically stirring at 500rpm at 70 deg.C for 30min to form water continuous phase;

(3) adding the oleogel dispersed phase into the water continuous phase, and homogenizing and emulsifying for 3 minutes at a shear rate of 10000rpm to obtain the oleogel-based emulsion.

Example 6

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 2g sunflower seed oil and 0.2g beeswax, magnetically stirring at 135 deg.C and 900rpm for 45min, and standing to room temperature to obtain condensed oleogel dispersed phase;

(2) adding 0.45g monoglyceride into 18g water, and magnetically stirring at 500rpm at 90 deg.C for 30min to form water continuous phase;

(3) adding the oleogel dispersed phase into the water continuous phase, and homogenizing and emulsifying for 3 minutes at a shear rate of 10000rpm to obtain the oleogel-based emulsion.

Example 7

Preparation of an oleogel-based emulsion stabilized by interfacial crystallization:

(1) mixing 2g sunflower seed oil and 0.04g rice bran wax, and magnetically stirring at 85 deg.C and 900rpm for 45min to obtain molten oleogel dispersed phase;

(2) adding 0.45g of diglyceride into 18g of water, and magnetically stirring at 500rpm for 30min at 70 ℃ to form a water continuous phase;

(3) and adding the oil gel dispersion phase into the water continuous phase, and homogenizing at a high-pressure homogenizing pressure of 50MPa for 2 minutes to emulsify to obtain the oil gel-based emulsion.

Comparative example 1

The difference from the embodiment 1 is that: the amphiphilic functional lipid in the aqueous continuous phase was replaced with the conventional emulsifier tween 80 and used as the aqueous continuous phase.

Comparative example 2

Conventional emulsions

(1) No gelling agent is added in the oil phase, and 4g of sunflower seed oil is used as the oil phase;

(2) adding 0.5g lecithin into 16g water, and magnetically stirring at 500rpm at 90 deg.C for 30min to form water continuous phase;

(3) adding the oil phase into the water continuous phase, and carrying out ultrasonic treatment for 2 minutes at the ultrasonic power of 50% to obtain the conventional emulsion.

To further illustrate the technical effects of the present invention, the following tests and analyses were performed on the properties and microstructures of the emulsions prepared in some of the examples and comparative examples.

Test example 1, interfacial rheology test

The same composition of the oil gel dispersed phase and the water continuous phase of examples 1, 2, 3, 1 and 2 of the present invention was used for the interfacial rheology test, and the test results are shown in fig. 1.

As can be seen from the test results in FIG. 1, the elastic modulus G 'at the interface is larger than the loss modulus G' at the interface, which is formed only in examples 1-3, and thus it is demonstrated that only examples 1-3 can form a solid-like rigid film, i.e., ceramide crystals are adsorbed to the oil-water interface to form a solid-like rigid film, and the hydrogel-based emulsion is stabilized by interfacial crystallization. While for comparative examples 1, 2, the interfacial elastic modulus G' is always smaller than the interfacial loss modulus G ", indicating that comparative examples 1, 2 are emulsions stabilized with only amphiphilic functional lipids.

Test example 2 microstructure test

Microstructure observation was performed using the emulsions prepared in example 1, example 2, example 3, comparative example 1, and comparative example 2 as test samples, and the structures and crystal distributions of the oleogel-based emulsion and the conventional emulsion were observed under polarized light by an Olympus microscope, and the test results are shown in fig. 2.

As can be seen from the test results of FIG. 2, in the polarization diagrams of the resulting oil gel-based emulsions of examples 1-3, the droplets of the emulsions were all covered with crystals, and the coverage increased with the increase in the concentration of the gelling agent. In contrast, for comparative example 1, the crystals in the oleogel-based emulsion were distributed in the continuous phase, and there was no crystal coverage at the droplet interface. In contrast, for comparative example 2, the presence of crystals was not observed since the conventional emulsion was not added with a gelling agent.

Test example 3 storage stability test

Storage tests were conducted using the various oil gel-based emulsions prepared in examples 1 to 3 and comparative examples 1 to 2 and conventional emulsions as test samples, and the stability of the emulsions was characterized by measuring the difference in particle size between the samples of each emulsion after 14 days of storage and just after the preparation, and the test results are shown in FIG. 3.

As can be seen from the test results of fig. 3, the particle size difference between the emulsion of comparative examples 1-2 and the emulsion just prepared after 14 days of storage is significantly higher than that of examples 1-3, the conventional emulsifier tween is used in comparative example 1, no gel crystal is used in comparative example 2, the particle size of the emulsion just prepared is smaller, but the unstable phenomenon of the increase of the particle size of the emulsion still exists after 14 days of storage; while the particle size of the interfacial crystallization stable oil gel-based emulsion of examples 1-3 after 14 days of storage did not change much from the particle size of the emulsion just prepared, i.e., no coalescence, flocculation, etc. occurred, indicating that the oil gel-based emulsion prepared by the present invention has better storage stability than the comparative example, and the instability problem caused by the aggregation of droplets, which is very easy to occur during the storage and processing of the emulsion, is improved.

The above experimental examples are preferred experimental modes of the present invention, but the embodiments of the present invention are not limited to the above examples. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.