CN113083173B

CN113083173B - Water-in-oil Pickering emulsion gel and preparation method thereof

Info

Publication number: CN113083173B
Application number: CN202110412880.3A
Authority: CN
Inventors: 毛立科; 刘楠; 柯翔宇; 张若宁; 高彦祥
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2021-04-16
Filing date: 2021-04-16
Publication date: 2022-04-22
Anticipated expiration: 2041-04-16
Also published as: CN113083173A

Abstract

The invention relates to the field of gel, and discloses a water-in-oil Pickering emulsion gel and a preparation method thereof, wherein the method comprises the following steps: (1) carrying out first contact mixing on an oil material and ethyl cellulose I to dissolve the ethyl cellulose I to obtain a solution I, and cooling the solution I to obtain an oleogel I; carrying out second contact mixing on ethyl cellulose II and monohydric alcohol to obtain a solution II, mixing the solution II with water to obtain a solution III, and carrying out alcohol removal treatment on the solution III to obtain a water dispersion I; (2) carrying out third contact mixing on the oil gel I and the water dispersion I to obtain a solution III; (3) and homogenizing the solution III. The method provided by the invention obtains the Pickering particles and the oil gel network from a single component, and can realize the bistable state of the emulsion.

Description

Water-in-oil Pickering emulsion gel and preparation method thereof

Technical Field

The invention relates to the field of gel, and particularly relates to a water-in-oil Pickering emulsion gel and a preparation method thereof.

Background

Water-in-oil emulsions are used in a wide variety of food, cosmetic and pharmaceutical applications, such as margarine, which is a common type of water-in-oil system in daily life. Meanwhile, most cream products in cosmetics and skin care products are water-in-oil type emulsions.

The water-in-oil emulsion has good skin-friendly property, water retention property and active ingredient loading property, but has poor stability, and is easy to generate demulsification and stratification under the conditions of heating, cooling, freezing-thawing, drying and the like, so that the application of the water-in-oil emulsion is limited to a certain extent. The conventional process for preparing water-in-oil emulsions requires the use of large amounts of surfactants to ensure the stability of the emulsions, but excessive amounts of surfactants may cause environmental and safety problems.

The Pickering emulsion based on particle stability has the advantages of high emulsion stability, no surfactant and the like, but most of particles used at present are inorganic and organic synthetic particles, so that the application in the industries of food, medicine and the like is very limited, and meanwhile, the food-grade particles which can be used for the water-in-oil type Pickering emulsion are very few, are mostly fat crystals, polyphenol crystals and the like, and have the adverse conditions of poor stability, complex process and the like.

CN109199921A discloses a gel-like water-in-oil emulsion composition, a preparation method and application thereof. The gel water-in-oil emulsion composition provided by the invention has excellent stability and has the effects of moistening and moisturizing and the like. However, the method needs 1-10% of emulsifier, including one or more of fatty acid monoglyceride, polyglycerol fatty acid ester, lecithin, alkyl glycoside, sorbitan fatty acid ester and the like, so that the application of the emulsifier in food is limited, a certain load is caused on skin after long-term use, and the requirement related to the current cleaning label is not met.

CN110946285A discloses a water-in-oil Pickering emulsion based on phytosterol stabilization, and a preparation method and application thereof. Compared with the traditional preparation method of the water-in-oil type particle stabilizer, the method can produce the water-in-oil type Pickering emulsion with good stability without adding a surfactant or chemical modification, but the pictures provided by the prior art can show that the sample has unstable phenomena such as oil-water stratification and the like with different degrees.

Oleogels are a thermally reversible viscoelastic, semi-solid lipid mixture. During the preparation process, the gelata is heated and dissolved in the grease, self-assembly is realized among gelata molecules through non-covalent bond effects such as hydrogen bonds, van der waals force and the like during cooling, and the gelata further aggregates to form a three-dimensional network structure to limit the flow of liquid oil, so that oleogel is formed. The gelling agent is compounded or other components are added, so that the oil gelation process and the structural characteristics of the oil gel can be regulated and controlled. Oleogels can mimic the rheological and textural properties of fats, but at the same time retain the health attributes of vegetable oils. The Pickering emulsion stabilized by the nanoparticles adsorbed on the oil-water interface is free of surfactant, and the Pickering mechanism can also obviously inhibit unstable phenomena such as liquid drop aggregation, flocculation and the like in the water-in-oil emulsion.

The water drops containing the nano particles are uniformly dispersed into the oil gel in a homogenizing emulsification mode, so that the water-in-oil Pickering emulsion gel can be formed. On one hand, the oil phase is structured, so that the water-in-oil emulsion has stronger stability and better plasticity, and on the other hand, the nanoparticles on the interface of the water drops and the oil gel have good emulsification effect, so that the water drops are uniformly distributed and are not easy to gather together, and the stability of the emulsion is enhanced.

Disclosure of Invention

The invention aims to overcome the defects of poor stability and easy phase separation of the traditional water-in-oil emulsion.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing a water-in-oil type Pickering emulsion gel, characterized in that the method comprises:

(1) carrying out first contact mixing on an oil material and ethyl cellulose I to dissolve the ethyl cellulose I to obtain a solution I, and cooling the solution I to obtain an oleogel I; and

carrying out second contact mixing on ethyl cellulose II and monohydric alcohol to obtain a solution II, mixing the solution II with water to obtain a solution III, and carrying out alcohol removal treatment on the solution III to obtain a water dispersion I;

(2) carrying out third contact mixing on the oil gel I and the water dispersion I to obtain a solution III;

(3) homogenizing the solution III to obtain the water-in-oil Pickering emulsion gel;

wherein the viscosity values of the ethyl cellulose I and the ethyl cellulose II are the same or different.

A second aspect of the present invention provides a water-in-oil Pickering emulsion gel prepared by the method described in the aforementioned first aspect.

The stable and biocompatible water-in-oil Pickering emulsion gel can be obtained by adopting ethyl cellulose, alcohol solvent and water solvent in a specific dosage proportion relationship.

The water-in-oil type Pickering emulsion gel provided by the invention has the advantage of good stability.

Further, the water-in-oil type Pickering emulsion gel provided by the invention also has the advantages of protecting and efficiently delivering functional factors.

In addition, the method for preparing the water-in-oil type Pickering emulsion gel provided by the invention obtains the Pickering particles and the oil gel network from a single component, and can realize the bistable state of the emulsion.

The water-in-oil type Pickering emulsion gel can be used as a fat substitute, can be used as a nutritional food preparation, can embed a hydrophobic functional factor and a hydrophilic functional factor, and is widely applied to development of functional (health-care) foods, medicines, cosmetics and the like. For example, the method provided by the invention can be used for producing water-in-oil Pickering emulsion gel containing curcumin so as to improve the loading capacity and stability of the active substance.

Additional features and advantages of the invention will be described in detail in the detailed description which follows.

Drawings

FIG. 1 is a projection electron microscope observation image of nanoparticles in an aqueous dispersion I prepared in example 1;

FIG. 2 is an appearance diagram of a sample after leaving the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3 and comparative example 1 at room temperature for 1 day (24h) without sealing;

FIG. 3 is an optical micrograph of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3, and comparative example 1 after being left unsealed at room temperature for 1 day (24 h);

FIG. 4 is a graph showing the mass-structure characteristics of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3, and comparative example 1 after being left unsealed at room temperature for 1 day (24 hours);

FIG. 5 is a graph showing the rheological characteristics of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3, and comparative example 1 after being left unsealed at room temperature for 1 day (24 hours);

FIG. 6 is a graph showing the effect of water retention of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3, and comparative example 1 after being left unsealed at room temperature for 1 day (24 hours).

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

Unless otherwise specified, the rotation speed of stirring is not particularly limited, and stirring may be carried out to a uniform state as understood by those skilled in the art.

According to the first aspect of the present invention, the present invention provides the following preferred embodiments.

The ethyl cellulose I and the ethyl cellulose II are the same or different in type and are both a derivative of cellulose.

Preferably, the viscosity values of the ethylcellulose I and the ethylcellulose II are each independently selected from the range of 9 to 150 mpa.s.

According to a particularly preferred embodiment, the viscosity of the ethylcellulose I is less than the viscosity of the ethylcellulose II. Further preferably, the viscosity of the ethylcellulose I is selected from 9 to 30mpa.s, and the viscosity of the ethylcellulose II is selected from 90 to 150 mpa.s. The inventor finds that the gel hardness of the water-in-oil type Pickering emulsion obtained under the further preferable condition is moderate, and the water-in-oil type Pickering emulsion is suitable for being widely applied in the food, cosmetic and pharmaceutical industries.

Preferably, the oil is selected from at least one of corn oil and peanut oil.

Preferably, in step (1), the first contact mixing is carried out in the presence of stirring, and the conditions of the first contact mixing at least satisfy: the temperature is 140-160 ℃, and the time is 15-30 min.

Preferably, in step (1), the amount of the ethyl cellulose I is such that the content of the ethyl cellulose I in the solution I is from 7wt% to 16wt%, more preferably from 10wt% to 12 wt%.

According to a preferred embodiment, the method further comprises: in step (1), the oil is subjected to the first contacting mixing with the ethylcellulose I and a surfactant.

Preferably, in step (1), the surfactant is used in an amount such that the content of the surfactant in the solution I is 0.01 to 6wt%, more preferably 4 to 6 wt%.

Preferably, the surfactant is at least one selected from span 40, span 60, fatty acid monoglyceride and polyglyceryl fatty acid ester.

Preferably, the cooling conditions include: naturally cooling to room temperature.

Preferably, in step (1), the second contact mixing is performed in the presence of stirring, and the conditions of the second contact mixing at least satisfy: the temperature is 40-50 deg.C, and the time is 10-20 min.

Preferably, in step (1), the amount of the ethylcellulose II and the monohydric alcohol is such that the content of the ethylcellulose II in the solution II is 0.8-2 wt%.

Preferably, in step (1), the monohydric alcohol is ethanol.

Preferably, in the step (1), the volume ratio of the solution II to the water in the preparation of the solution III is 1:9 to 8: 2.

preferably, in step (1), during the preparation of the solution III, the mixing is performed in the presence of stirring, and the mixing conditions at least satisfy: the stirring speed is 1000-20000 rpm, and the stirring time is 1-4 min.

Preferably, in the step (1), the condition of the alcohol removal treatment is controlled so that the content of the ethyl cellulose II in the prepared water dispersion I is 8-20 g of ethyl cellulose II/1L of water. The present invention does not require any particular step for the alcohol removal treatment as long as the aforementioned criteria can be met, and the following description of the present invention exemplifies a particular operation for the alcohol removal treatment, and those skilled in the art should not be construed as limiting the present invention.

Preferably, in the step (2), the weight ratio of the oil gel I to the water dispersion I is 6:4 to 9: 1.

in the step (2), the third contact reaction may be carried out in the presence of stirring, but there is no particular requirement for a specific speed of stirring. Also, it is preferable that the third contact reaction is carried out at 10 to 40 ℃.

Preferably, in step (3), the condition of the homogenization treatment at least satisfies: the stirring speed is 1000-13000 rpm, and the homogenizing time is 1-3 min.

The process described in the first aspect of the invention, and the water-in-oil Pickering emulsion gel described in the second aspect of the invention obtained by the aforementioned process of the invention, also have the following specific advantages:

1) the invention adopts a new production process, does not need additional stabilizer, and can produce and obtain the water-in-oil Pickering emulsion gel with good stability, thereby obviously overcoming the defects of poor stability or large amount of emulsifier of the existing water-in-oil emulsion.

2) Compared with the traditional Pickering emulsion, the water-in-oil Pickering emulsion gel produced by the invention has higher stability and stronger plasticity, and can be adjusted by adjusting the strength of the oil gel, the particle size and the concentration of the ethyl cellulose nano particles and the oil-water phase ratio, thereby producing a series of different water-in-oil Pickering emulsion gels.

3) The water-in-oil type Pickering emulsion gel produced by the invention can be used as a fat substitute (based on liquid vegetable oil) and a nutritional food preparation, and the oleogel, the nanoparticles and the water phase can simultaneously load a hydrophobic functional factor and a hydrophilic functional factor, so that the water-in-oil type Pickering emulsion gel is widely used for development of functional (health-care) foods, medicines, cosmetics and the like. For example, the method of the invention can be used for producing water-in-oil Pickering emulsion gel containing curcumin, and can remarkably improve the loading capacity and stability of the active substance.

The present invention will be described in detail below by way of examples.

In the following examples, room temperature means 25. + -. 2 ℃ unless otherwise specified.

In the following examples, the raw materials used are all common commercial products unless otherwise specified.

The following conditions of room temperature standing were: and (5) storing the mixture in a shady and dry place in an open way.

Ethyl cellulose I-1, CAS No. 9004-57-3, product No. E110670, viscosity value 9-11 mPa.s, purchased from Shanghai Aladdin Biotechnology Ltd;

ethyl cellulose II-1, CAS No. 9004-57-3, product No. E110673, viscosity value of 90-110 mPa.s, purchased from Shanghai Aladdin Biotechnology Ltd;

ethyl cellulose II-2, CAS No. 9004-57-3, product No. E110672, viscosity value of 45-55 mPa.s, purchased from Shanghai Aladdin Biotechnology Ltd;

edible corn oil, purchased from Shandong Sanxing corn industries, science and technology Co., Ltd;

edible peanut oil, purchased from Shandong Sanxing corn industries, science and technology Co., Ltd;

span 40, CAS number 26266-57-9, available from Shanghai Maxin Biotechnology Ltd.

Preparation example 1

Ethyl cellulose II-1 was dispersed in absolute ethanol at room temperature, followed by heating at 45 ℃ for 15 minutes to obtain 1000g of a 0.8 wt% ethyl cellulose ethanol solution A1 for use.

Preparation example 2

Ethyl cellulose II-1 was dispersed in absolute ethanol at room temperature, followed by heating at 45 ℃ for 15 minutes to obtain 1000g of an ethanol solution A2 of ethyl cellulose having a concentration of 1.5% by weight, for use.

Preparation example 3

Ethyl cellulose II-1 was dispersed in absolute ethanol at room temperature, followed by heating at 45 ℃ for 15 minutes to obtain 1000g of an ethanol solution A3 of ethyl cellulose having a concentration of 2.0% by weight, for use.

Preparation example 4

Ethyl cellulose II-2 was dispersed in absolute ethanol at room temperature, followed by heating at 45 ℃ for 15 minutes to obtain 1000g of a 0.8 wt% ethyl cellulose ethanol solution A4 for use.

Example 1

(1) Under stirring, performing first contact mixing on corn oil, ethyl cellulose I-1 and span 40 (the first contact mixing condition is that the temperature is 150 ℃ and the time is 20min) to obtain a solution I, and standing and cooling the solution I (the cooling operation condition is that natural cooling is performed at room temperature) to obtain oleogel I, wherein the concentration of ethyl cellulose in the oleogel I is 12wt%, the concentration of span 40 is 6wt%, the balance is corn oil, and the total amount of the oleogel I is 1000 g;

mixing A1 obtained in preparation example 1 and water in a volume ratio of 5: 5 (the mixing condition is that shearing homogenization is carried out for 3min at 13000 rpm) to obtain 500ml of solution III, and the solution III is subjected to dealcoholization treatment by rotary evaporation to remove ethanol (the dealcoholization treatment condition is that the temperature is 42 ℃, the pressure is 0.1Mpa and the time is 20min) to obtain an aqueous dispersion I, and the content of the ethyl cellulose in the aqueous dispersion I is 8g of ethyl cellulose/1L of water;

(2) under stirring, mixing the oil gel I and the water dispersion I in a weight ratio of 6:4 carrying out third contact mixing (the temperature of the third contact mixing is room temperature) to obtain 500ml of solution III;

(3) and (3) homogenizing the solution III (the homogenizing condition is that shearing homogenization is carried out for 3min at 11000 rpm), so as to obtain the water-in-oil Pickering emulsion gel.

Example 2

(1) Under stirring, performing first contact mixing on corn oil, ethyl cellulose I-1 and span 40 (the first contact mixing condition is that the temperature is 160 ℃ and the time is 15min) to obtain a solution I, and standing and cooling the solution I (the cooling operation condition is that natural cooling is performed at room temperature) to obtain oleogel I, wherein the concentration of ethyl cellulose in the oleogel I is 16wt%, the concentration of span 40 is 5 wt%, the balance is corn oil, and the total amount of the oleogel I is 1000 g;

mixing A2 obtained in preparation example 2 and water in a volume ratio of 5: 5 (the mixing condition is that shearing homogenization is carried out for 3min at 13000 rpm) to obtain 500ml of solution III, and the solution III is subjected to dealcoholization treatment by rotary evaporation to remove ethanol (the dealcoholization treatment condition is that the temperature is 42 ℃, the pressure is 0.1Mpa and the time is 20min) to obtain an aqueous dispersion I, and the content of the ethyl cellulose in the aqueous dispersion I is 15g of ethyl cellulose/1L of water;

Example 3

This example was carried out in a similar manner to example 1, except that:

in this example, in the step of preparing the aqueous dispersion I, a1 was replaced with A3 obtained in preparation example 3 in the same amount, and the content of ethylcellulose in the aqueous dispersion I obtained in this example was 20g of ethylcellulose per 1L of water.

The rest is the same as in example 1.

This example gives a water-in-oil Pickering emulsion gel.

Example 4

This example was carried out in a similar manner to example 1, except that:

in this example, the oil used in the preparation of oil gel I was peanut oil, of the same weight.

The rest is the same as in example 1.

This example gives a water-in-oil Pickering emulsion gel.

Example 5

This example was carried out in a similar manner to example 1, except that:

in this example, in the step of preparing the aqueous dispersion I, a1 was replaced with a4 obtained in preparation example 4 in the same amount, and the content of ethylcellulose in the aqueous dispersion I obtained in this example was 20g of ethylcellulose per 1L of water.

The rest is the same as in example 1.

This example gives a water-in-oil Pickering emulsion gel.

Comparative example 1

(1) The same oleogel I as in example 1 was prepared in the same manner as in step (1) of example 1;

(2) under stirring, mixing the oleogel I and distilled water in a weight ratio of 6:4 carrying out third contact mixing (the temperature of the third contact mixing is room temperature) to obtain 500ml of solution III;

(3) and (3) homogenizing the solution III (the homogenizing condition is that shearing homogenization is carried out for 3min at 11000 rpm) to obtain the water-in-oil emulsion gel.

Comparative example 2

This comparative example prepared oleogel I and aqueous dispersion I in the same manner as example 1, except that:

the same mass of methyl cellulose is used to replace ethyl cellulose I-1 and ethyl cellulose II-1, respectively.

As a result, the same oil gel I and aqueous dispersion I as in example 1 could not be formed, and thus a water-in-oil emulsion could not be formed.

Comparative example 3

the same mass of sodium carboxymethyl cellulose is adopted to replace the ethyl cellulose I-1 and the ethyl cellulose II-1 respectively.

Test example

The properties of the gels obtained in the foregoing examples were respectively tested, and specific test methods and test results are as follows.

The test method comprises the following steps:

observation of gel appearance and microstructure: the appearance of the gel was observed by naked eye, the microstructure was observed by microscope;

gel rheological and texture characteristics: analyzed by AR1500 rheometer and CT3 Brookfield texture analyzer;

and (3) measuring the water and oil holding capacity of the gel: centrifuging the sample at 4200rpm for 15min, and testing the water and oil holding capacity of the sample, wherein specifically, the water holding capacity is judged by observing the aggregation condition of water drops at the bottom of the emulsion gel by naked eyes; the oil holding capacity is calculated by calculating the percentage of the mass of the residual oil in the emulsion gel to the total mass of the oil before centrifugation;

creep-recovery test: the recovery of the sample within 400s was measured by applying a stress of 1Pa using an AR1500 rheometer, maintaining for 200s, and then removing the stress, the creep compliance being defined as the change in strain at constant unit stress, and the creep recovery (δ J) being calculated as follows:

wherein the compliance (unit is 1/Pa) when J (200s) is 200s, and the compliance (unit is 1/Pa) when J (600s) is 600 s.

And (3) testing results:

TABLE 1

Example 1

Example 2

Example 3

Example 4

Example 5

Comparative example 1

Droplet diameter

<200μm

＞200μm

Oil retention

51.25％

50.10％

48.51％

51.13％

46.89％

44.88％

Creep-recovery ratio

64.96％

56.15％

54.86％

62.78％

42.92％

35.78％

In addition, the present invention exemplarily provides a projection electron microscope observation view of the nanoparticles in the aqueous dispersion I prepared in example 1, as shown in fig. 1. As can be seen from fig. 1, the average particle size of the nanoparticles was around 110nm, and the nanoparticles in the dispersion I were left unsealed at room temperature for 1 month, and were found to have no significant change in appearance and particle size again by the projection electron microscope.

The invention exemplarily provides appearance images and optical microscope pictures of samples of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in the examples 1, 2 and 3 and the comparative example 1 after being left for 1 day (24h) at room temperature without sealing, as shown in FIGS. 2 and 3, respectively.

As can be seen from fig. 2, the emulsion gels provided in examples 1, 2, and 3 have better plasticity than comparative example 1.

As can be seen from fig. 3, compared with comparative example 1, the emulsion gels provided in examples 1, 2, and 3 have smaller water droplet particle size, more uniform distribution, and better emulsion stability, and the water droplet shapes in examples 1, 2, and 3 are more irregular, which proves that nanoparticles exist at the water droplet interface, the whole water droplet has certain rigidity, can maintain a certain shape in the oil gel medium, and the water droplets are not easy to aggregate with each other, and have stronger water holding capacity.

The present invention exemplarily provides graphs of the texture characteristics and the rheological characteristics of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3, comparative example 1 after being left for 1 day (24h) at room temperature without sealing, as shown in fig. 4 and fig. 5, respectively.

As can be seen from fig. 4, the W/O type Pickering emulsion gels obtained in examples 1, 2 and 3 have a slightly higher hardness and a higher viscosity than those of comparative example 1.

As can be seen from fig. 5, the W/O type Pickering emulsion gels (EC NPs) obtained in examples 1, 2 and 3 have higher complex modulus, higher viscoelasticity, higher shear viscosity, higher elasticity, and higher resistance to deformation under the same stress, and the W/O type Pickering emulsion gels have higher viscoelasticity and higher shear viscosity as the concentration of ethylcellulose II increases.

The present invention exemplarily provides a graph showing the results of water holding capacity test of the water-in-oil Pickering emulsion gel or the water-in-oil emulsion gel prepared in example 1, example 2, example 3, and comparative example 1 after being left for 1 day (24h) at room temperature without sealing, as shown in fig. 6.

As is clear from fig. 6, the W/O type Pickering emulsion gels obtained in examples 1, 2 and 3 have better water-holding effects than comparative example 1.

According to the results of the invention, the W/O type Pickering emulsion gel provided by the invention is moderate in hardness, uniform and stable, good in plasticity and good in oil holding effect.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for preparing a water-in-oil Pickering emulsion gel, the process comprising:

(1) performing first contact mixing on an oil material and ethyl cellulose I to dissolve the ethyl cellulose to obtain a solution I, and cooling the solution I to obtain an oleogel I, wherein the content of the ethyl cellulose I is 7-16 wt%; and

carrying out second contact mixing on ethyl cellulose II and monohydric alcohol to obtain a solution II; mixing the solution II with water to obtain a solution III, and carrying out dealcoholization treatment on the solution III to obtain an aqueous dispersion I containing nanoparticles, wherein the content of the ethyl cellulose II is 0.8-2 wt%;

(2) carrying out third contact mixing on the oil gel I and the water dispersion solution I containing the nano particles to obtain a solution IV;

(3) homogenizing the solution IV to obtain the water-in-oil Pickering emulsion gel;

2. The process according to claim 1, the ethylcellulose I having a viscosity value selected from the range of 9-30mpa.s and the ethylcellulose II having a viscosity value selected from the range of 90-150 mpa.s.

3. The method according to claim 1, wherein, in step (1), the first contact mixing is carried out in the presence of stirring, and the conditions of the first contact mixing are at least satisfied: the temperature is 140-160 ℃, and the time is 15-30 min.

4. The process according to any one of claims 1 to 3, the amount of ethylcellulose I used is such that the content of said ethylcellulose I in said solution I is from 10% to 12% by weight.

5. The method of any of claims 1-3, wherein the method further comprises: in step (1), subjecting the oil to said first contacting mixing with said ethylcellulose I and a surfactant;

in the step (1), the surfactant is used in an amount such that the content of the surfactant in the solution I is 0.01wt% to 6 wt%.

6. The method of claim 5, wherein the surfactant is present in an amount of 4wt% to 6 wt%.

7. The process according to any one of claims 1 to 3, wherein in step (1), the second contact mixing is carried out in the presence of stirring, and the conditions of the second contact mixing are at least satisfied: the temperature is 40-50 deg.C, and the time is 10-20 min.

8. The process of any one of claims 1-3, wherein, in step (1), the monohydric alcohol is ethanol.

9. The method according to any one of claims 1 to 3, wherein in step (1), the volume ratio of the solution II to the water used in the preparation of the solution III is 1:9 to 8: 2; in the step (1), in the process of preparing the solution III, the mixing is carried out in the presence of stirring, and the conditions of the mixing are at least satisfied: the stirring speed is 1000-20000 rpm, and the stirring time is 1-4 min.

10. The method according to any one of claims 1 to 3, wherein in the step (1), the alcohol removal treatment is carried out under such conditions that the content of ethylcellulose II in the prepared aqueous dispersion I is 8 to 20g of ethylcellulose per 1L of water.

11. The process according to any one of claims 1 to 3, wherein in step (2) the weight ratio of the oleogel I to the aqueous dispersion I is from 6:4 to 9: 1.

12. The method according to any one of claims 1 to 3, wherein in step (3), the condition of the homogenization treatment at least satisfies: the shearing speed is 1000-13000 rpm, and the homogenizing time is 1-3 min.

13. A water-in-oil Pickering emulsion gel prepared by the method of any one of claims 1 to 12.