A natural emulsifier, a preparation method and application thereof in high internal phase emulsion

Abstract

The application discloses a natural emulsifier, a preparation method and application of the natural emulsifier in high internal phase emulsion, and belongs to the technical field of emulsion. As a hydrophobic protein, the zein has poor emulsion stability, and a hydrophilic component is usually introduced to enhance the hydrophilicity. In the application, the internal hydrophobic cavity of a natural small molecule cyclodextrin is used to have a hydrophobic interaction with the zein to prepare a composite particle. The hydrophilic shell of the cyclodextrin can improve the problem of the zein having too strong hydrophobicity. The prepared composite particle can be used to prepare a high internal phase emulsion with various oil phases. By controlling the addition amount of the zein and the cyclodextrin, the interfacial affinity of the particle can be regulated. Furthermore, by adjusting the pH of a dispersion liquid, the viscosity of the emulsion can be regulated.

Description

Technical Field

[0001] This invention belongs to the field of emulsion technology, and particularly relates to a natural emulsifier applicable to the preparation of high internal phase emulsions in various oil phases and its preparation method. Background Technology

[0002] Traditional emulsions use surfactants for stability, but recent reports have indicated that surfactants have negative environmental and human health effects, and the low stability of surfactant-based emulsions limits their application. Emulsions, due to their higher stability and lower harm to humans, have become a research hotspot. Common emulsions include inorganic particles, but inorganic particles have poor biocompatibility. Therefore, emulsions prepared from biomacromolecules have come into focus. Among these, plant proteins and polysaccharides have received widespread attention due to their high yield and low carbon footprint.

[0003] Zeatin is a hydrophobic plant protein with a high content and abundant reserves of nonpolar amino acids. This protein is a good raw material for preparing natural emulsions, but some of its inherent drawbacks, such as pH sensitivity and strong hydrophobicity preventing dispersion in water, limit its application in emulsions. Researchers often modify it by adding hydrophilic substances through electrostatic interactions, but the resulting zeatin composite particles produce emulsions with low stability, and typically only one oil phase can be stabilized for emulsion preparation. Summary of the Invention

[0004] To address the problem that zein is difficult to form relatively stable natural emulsions and often can only stabilize one oil phase in emulsion preparation, this invention provides a natural emulsifier, a preparation method, and its application in high internal phase emulsions.

[0005] The technical solution of this invention:

[0006] A method for preparing a natural emulsifier, wherein the natural emulsifier is a composite particle formed by zein and β-cyclodextrin through hydrophobic interaction.

[0007] A method for preparing a natural emulsifier, the specific steps of which are as follows:

[0008] (1) Prepare a β-cyclodextrin solution by dissolving β-cyclodextrin in water;

[0009] (2) Add ethanol to the β-cyclodextrin solution to prepare an alcohol-water solution, add zein and dissolve by ultrasonication and magnetic stirring;

[0010] (3) Pour the solution obtained in step (2) into the same volume of water, stir magnetically and then evaporate by rotary evaporation to obtain a dispersion;

[0011] (4) Dialyze the dispersion obtained in step (3) using a dialysis bag, and then freeze-dry it to obtain zein cyclodextrin complex particles, i.e., natural emulsifier.

[0012] Furthermore, in step (1), the concentration of the β-cyclodextrin solution is 2-10 mg / mL;

[0013] Furthermore, in step (2), ethanol is added to adjust the ethanol content to 54-70 (v / v)%; the amount of zein added is 0.5-10 times the mass of β-cyclodextrin; and the magnetic stirring conditions are 500-1000 rpm for 1-5 h (preferably 500 rpm for 5 h).

[0014] Furthermore, in step (3), the magnetic stirring conditions are 500-1000 rpm for 0.5-3 h (preferably 500 rpm for 0.5 h), the rotary evaporation temperature is 45-65℃, and the rotary evaporation time is 5-40 min.

[0015] Furthermore, in step (4), the molecular weight cutoff of the dialysis bag is 0.2-12 kDa, the dialysis time is 36-48 h, the freeze-drying temperature is -20 to -80℃ (preferably -60℃), and the freeze-drying time is 48 h-72 h.

[0016] The above-mentioned preparation method is used to prepare a natural emulsifier in the preparation of a high internal phase emulsion. The high internal phase emulsion is composed of three components: natural emulsifier, oil phase, and water. The concentration of the natural emulsifier is 10-30 mg / mL, and the volume ratio of the oil phase to the water phase is 7.5:2.5-9:1.

[0017] Furthermore, a method for preparing a high internal phase emulsion involves initially mixing and homogenizing a natural emulsifier with an oil phase and water.

[0018] Furthermore, the oil phase Log P range is 1.14-9.26 (e.g., corn oil, soybean oil, hexadecane, etc.); the homogenizer speed is 8000-15000 r / min, and the homogenization time is 100-300 s.

[0019] Furthermore, high internal phase emulsion delivery systems are applied in the fields of food, cosmetics, and bio-inks.

[0020] The beneficial effects of this invention are:

[0021] This invention provides a natural emulsifier suitable for preparing high internal phase emulsions in various oil phases. It is based on zein and utilizes the hydrophobic cavities within the amphiphilic cyclodextrin to interact with zein, creating composite particles. The hydrophilic outer portion of the cyclodextrin mitigates the excessive hydrophobicity of zein. This emulsifier exhibits excellent emulsifying properties and can prepare high internal phase emulsions with various oil phases over a wide pH range (pH 3-10). Furthermore, both the raw materials and the preparation process of this emulsion demonstrate excellent biocompatibility, making it a natural emulsion. Its primary applications are in the food and cosmetics industries, and the prepared high internal phase emulsion can be used in fields such as bio-inks. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the principle of the present invention. Anisotropic non-spherical composite particles were prepared by thoroughly mixing zein and β-cyclodextrin in solution and then combining the hydrophobic amino acid segments of zein with the hydrophobic cavities inside cyclodextrin.

[0023] Figure 2 HIPE images showing the stability of zein-cyclodextrin complex particles in different oil phases at different particle concentrations.

[0024] Figure 3 Microscopic images (B) showing the stability of zein-cyclodextrin complex particles in different oil phases at different particle concentrations.

[0025] Figure 4 Three-phase contact angles on thin films (substrates) made of different particles. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to the embodiments, but it should not be limited thereto. Equivalent substitutions to the technical solution of the present invention should also be within the scope of protection. Unless otherwise specified, the devices and equipment used in the following embodiments are all conventional devices and equipment in the art. Unless otherwise specified, the raw materials used in the following embodiments can be obtained commercially. Unless otherwise specified, the technical means used in the following embodiments are all well known in the art.

[0027] Example 1

[0028] Preparation of emulsifiers:

[0029] A β-cyclodextrin solution was prepared by dissolving 1 g of β-cyclodextrin in 100 mL of water at 25 °C. An alcohol-water solution was prepared by adding 120 mL of ethanol to the cyclodextrin solution, followed by ultrasonic dissolution of 1 g of zein, and magnetic stirring at 500 rpm for 5 h. The zein-cyclodextrin mixture was then poured into an equal volume of water, magnetically stirred at 500 rpm for 0.5 h, and rotary evaporated at 55 °C for 20 min. The evaporated dispersion was dialyzed through a dialysis bag (molecular weight cutoff 12 kDa) for 48 h and freeze-dried to obtain zein-cyclodextrin complex 1.

[0030] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 1 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified in a homogenizer at 12000 r / min for 300 s to obtain high internal phase emulsion 1a.

[0031] The prepared emulsifier, zein-cyclodextrin complex 1, was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with soybean oil at a volume ratio of 2.5:7.5. The mixture was then emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 1b.

[0032] The prepared emulsifier, zein-cyclodextrin complex 1, was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with hexadecane at a volume ratio of 2.5:7.5. The mixture was then emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 1c.

[0033] The prepared emulsifier, zein-cyclodextrin complex 1, was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 10 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was then emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 1d.

[0034] The prepared emulsifier, zein-cyclodextrin complex 1, was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 30 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was then emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 1e.

[0035] The prepared emulsifier, zein-cyclodextrin complex 1, was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 1:9. The mixture was then emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 1f.

[0036] Example 2

[0037] Preparation of emulsifier: 0.5 g of β-cyclodextrin was dissolved in 100 ml of water at 25 °C to prepare a β-cyclodextrin solution; 120 mL of ethanol was added to the cyclodextrin solution to prepare an alcohol-water solution, and 1 g of zein was added and dissolved by ultrasonication, followed by magnetic stirring at 500 rpm for 5 h. The zein-cyclodextrin mixture was poured into an equal volume of water, magnetically stirred at 500 rpm for 0.5 h, and then rotary evaporated at 55 °C for 20 min; the dispersion after rotary evaporation was dialyzed using a dialysis bag (molecular weight cutoff 12 kDa) for 48 h, and then freeze-dried to obtain zein-cyclodextrin complex 2.

[0038] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 2 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified in a homogenizer at 12000 r / min for 300 s to obtain high internal phase emulsion 2.

[0039] Example 3

[0040] Preparation of emulsifier: 0.3 g of β-cyclodextrin was dissolved in 100 ml of water at 25 °C to prepare a β-cyclodextrin solution; 120 mL of ethanol was added to the cyclodextrin solution to prepare an alcohol-water solution, and 1 g of zein was added and dissolved by ultrasonication, followed by magnetic stirring at 500 rpm for 5 h. The zein-cyclodextrin mixture was poured into an equal volume of water, magnetically stirred at 500 rpm for 0.5 h, and then rotary evaporated at 55 °C for 20 min; the dispersion after rotary evaporation was dialyzed using a dialysis bag (molecular weight cutoff 12 kDa) for 48 h, and then freeze-dried to obtain zein-cyclodextrin complex 3.

[0041] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 3 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified using a homogenizer at 12000 r / min for 300 s to obtain high internal phase emulsion 3.

[0042] Example 4

[0043] Preparation of emulsifier: 0.2 g β-cyclodextrin was dissolved in 100 ml of water at 25 °C to prepare a β-cyclodextrin solution; 120 mL of ethanol was added to the cyclodextrin solution to prepare an alcohol-water solution, and 2 g zein was added and dissolved by ultrasonication, followed by magnetic stirring at 500 rpm for 5 h. The zein-cyclodextrin mixture was poured into an equal volume of water, magnetically stirred at 500 rpm for 0.5 h, and then rotary evaporated at 55 °C for 20 min; the dispersion after rotary evaporation was dialyzed using a dialysis bag (molecular weight cutoff 12 kDa) for 48 h, and then freeze-dried to obtain zein-cyclodextrin complex 4.

[0044] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 4 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified using a homogenizer at 12000 r / min for 300 s to obtain high internal phase emulsion 4.

[0045] Example 5

[0046] Preparation of emulsifier: 1 g of β-cyclodextrin was dissolved in 100 ml of water at 25 °C to prepare a β-cyclodextrin solution; 230 mL of ethanol was added to the cyclodextrin solution to prepare an alcohol-water solution, and 1 g of zein was added and dissolved by ultrasonication, followed by magnetic stirring at 500 rpm for 5 h. The zein-cyclodextrin mixture was poured into an equal volume of water, magnetically stirred at 500 rpm for 0.5 h, and then rotary evaporated at 55 °C for 20 min; the dispersion after rotary evaporation was dialyzed using a dialysis bag (molecular weight cutoff 12 kDa) for 48 h, and then freeze-dried to obtain zein-cyclodextrin complex 5.

[0047] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 5 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified using a homogenizer at 12000 r / min for 300 s to obtain high internal phase emulsion 5.

[0048] Example 6

[0049] Preparation of emulsifier: 1 g of β-cyclodextrin was dissolved in 100 ml of water at 25 °C to prepare a β-cyclodextrin solution; 230 mL of ethanol was added to the cyclodextrin solution to prepare an alcohol-water solution, and 1 g of zein was added and dissolved by ultrasonication, followed by magnetic stirring at 1000 rpm for 5 h. The zein-cyclodextrin mixture was poured into an equal volume of water, magnetically stirred at 100 rpm for 0.5 h, and then rotary evaporated at 55 °C for 20 min; the dispersion after rotary evaporation was dialyzed using a dialysis bag (molecular weight cutoff 12 kDa) for 48 h, and then freeze-dried to obtain zein-cyclodextrin complex 6.

[0050] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 5 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 6.

[0051] Example 7

[0052] Preparation of emulsifier: 1 g of β-cyclodextrin was dissolved in 100 ml of water at 25 °C to prepare a β-cyclodextrin solution; 230 mL of ethanol was added to the cyclodextrin solution to prepare an alcohol-water solution, and 1 g of zein was added and dissolved by ultrasonication, followed by magnetic stirring at 500 rpm for 1 h. The zein-cyclodextrin mixture was poured into an equal volume of water, magnetically stirred at 500 rpm for 3 h, and then rotary evaporated at 55 °C for 20 min; the dispersion after rotary evaporation was dialyzed using a dialysis bag (molecular weight cutoff 12 kDa) for 48 h, and then freeze-dried to obtain zein-cyclodextrin complex 7.

[0053] Preparation of natural emulsion: The prepared emulsifier zein-cyclodextrin complex 5 was added to deionized water to form a suspension. The concentration of the emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified using a homogenizer at 12000 r / min for 300 s to obtain a high internal phase emulsion 7.

[0054] Comparative Example 1

[0055] Preparation of emulsifier: Dissolve 1g of zein in a mixture of 100mL water and 120mL ethanol, and stir magnetically at 500rpm for 5h. Pour the zein-cyclodextrin mixture into an equal volume of water, stir magnetically at 500rpm for 0.5h, and then rotary evaporate at 55℃ for 20min. Dialyze the evaporated dispersion using a dialysis bag (molecular weight cutoff 12kDa) for 48h, and freeze-dry to obtain 1 zein particle.

[0056] Preparation of natural emulsion: The prepared corn glycerin particles 1 were added to deionized water to form a suspension. The concentration of emulsifier in the suspension was 20 mg / mL. The suspension was mixed with corn oil at a volume ratio of 2.5:7.5. The mixture was emulsified using a homogenizer at 12000 r / min for 300 s to obtain high internal phase emulsion Comparative Example 1.

[0057] Depend on Figure 2 The zein-cyclodextrin complex particles shown can be used to prepare high internal phase emulsions with multiple oil phases at low particle concentrations. Figure 3 Verifiable Figure 2The results indicate that the complex can be used with different oil phases to prepare high internal phase emulsions. Figure 4 The three-phase contact angle test indicates that the composite particles (zein:cyclodextrin = 1:1) can stabilize different oil phases because their three-phase contact angles are similar in different oil phases.

[0058] Table 1

[0059] High internal phase emulsion 1a yes High internal phase emulsion 1b yes High internal phase emulsion 1c yes High internal phase emulsion 1d yes High internal phase emulsion 1e yes High internal phase emulsion 1f yes High internal phase emulsion 2 yes High internal phase emulsion 3 yes High internal phase emulsion 4 yes High internal phase emulsion 5 yes High internal phase emulsion 6 yes High internal phase emulsion 7 yes High internal phase emulsion comparative example 1 no

Claims

1. A method for preparing a natural emulsifier, characterized in that, The natural emulsifier mentioned is a composite particle formed by zein and β-cyclodextrin through hydrophobic interaction; (1) Prepare a β-cyclodextrin solution by dissolving β-cyclodextrin in water; (2) Add ethanol to the β-cyclodextrin solution to prepare an alcohol-water solution, add zein and dissolve by sonication and magnetic stirring; (3) Pour the solution obtained in step (2) into the same volume of water, stir magnetically and then evaporate by rotary evaporation to obtain a dispersion; (4) Dialyze the dispersion obtained in step (3) using a dialysis bag, and then freeze-dry it to obtain zein cyclodextrin complex particles, i.e., natural emulsifier.

2. The method for preparing a natural emulsifier according to claim 1, characterized in that, In step (1), the concentration of the β-cyclodextrin solution is 2-10 mg / mL; in step (2), ethanol is added to adjust the ethanol content to 54-70 (v / v)%; the amount of zein added is 0.5-10 times the mass of β-cyclodextrin; the magnetic stirring conditions are 500-1000 rpm for 1-5 h.

3. The method for preparing a natural emulsifier according to claim 1, characterized in that, In step (3), the magnetic stirring conditions are 500-1000 rpm, 0.5-3 h, rotary evaporation temperature is 45-65℃, and rotary evaporation time is 5-40 min.

4. The method for preparing a natural emulsifier according to claim 1, characterized in that, In step (4), the molecular weight cutoff of the dialysis bag is 0.2-12 kDa, the dialysis time is 36-48h, the freeze-drying temperature is -20 to -80℃, and the freeze-drying time is 48h-72h.

5. A natural emulsifier prepared by any one of the preparation methods described in claims 1-4.

6. The application of a natural emulsifier prepared by any one of claims 1-4 in the preparation of high internal phase emulsions, characterized in that, The high internal phase emulsion consists of three components: natural emulsifier, oil phase, and water. The concentration of the natural emulsifier is 10-30 mg / mL, and the volume ratio of the oil phase to the water phase is 7.5:2.5-9:

1.

7. The application according to claim 6, characterized in that, Method for preparing high internal phase emulsion: Natural emulsifier is initially mixed with oil phase and water and homogenized to obtain the emulsion.

8. The application according to claim 7, characterized in that, The oil phase Log P range is 1.14-9.26; the homogenizer speed is 8000-15000 r / min, and the homogenization time is 100-300 s.

9. The application according to claim 6, characterized in that, High internal phase emulsion delivery systems are applied in the fields of food, cosmetics, and bio-inks.

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