Method for preparing Pickering emulsion with β-cyclodextrin / sodium alginate blend

Abstract

The present invention discloses a method for preparing Pickering emulsions using a β-cyclodextrin / sodium alginate blend. First, an aqueous solution of β-cyclodextrin is mixed with an aqueous solution of sodium alginate, and then added to MCT. Pickering is prepared by high-speed shearing at room temperature. The obtained Pickering emulsion is allowed to stand for 1 day and then observed. Modifying β-cyclodextrin can effectively improve its inclusion efficiency, and for the first time, microscopic particle size analysis of β-cyclodextrin-sodium alginate Pickering emulsions is carried out.

Description

Technical Field

[0001] The invention relates to a method for preparing a Pickering emulsion by using a beta-cyclodextrin / sodium alginate blend. Background Art

[0002] Pickering emulsion gel is an emulsion gel formed by replacing surfactants with solid particles. Compared with traditional emulsion gel, Pickering emulsion gel has low cost, is green and environmentally friendly, is not easily affected by external factors (such as pH value, salt ion concentration and temperature, etc.), and has good stability. In recent years, there have been a large number of studies on the construction of Pickering emulsion gel using inorganic particles or organic polymers as particulate emulsifiers, but these particles have disadvantages such as poor degradability and low biocompatibility, which limits their application in the food field. Therefore, the development of food-grade natural solid particle emulsifiers has gradually become a research hotspot.

[0003] Cyclodextrin has been highly valued and widely used in the fields of food, medicine and cosmetics due to its good biocompatibility, strong embedding effect and easy degradation. Sodium alginate, as a thickener for beverages and dairy products, has unique advantages in thickening: the good fluidity of sodium alginate makes the beverage taste smooth after addition; and it can prevent the viscosity from decreasing during the product disinfection process. However, there are very few studies on Pickering emulsion gel based on cyclodextrin / sodium alginate. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a Pickering emulsion from a β-cyclodextrin / sodium alginate copolymer blend in view of the research gap in the Pickering emulsion, so as to obtain a Pickering emulsion with better performance.

[0005] The method for preparing Pickering emulsion by using a beta-cyclodextrin / sodium alginate blend of the present invention comprises the following steps: firstly, beta-cyclodextrin is fully dissolved in a solvent, and then sodium alginate is added and fully mixed with the solvent. Sodium alginate can combine with the hydroxyl group of beta-cyclodextrin to improve its encapsulation efficiency, and can also increase the viscosity of the emulsion to enhance its taste.

[0006] The β-cyclodextrin / sodium alginate copolymer in the present invention is abbreviated as β-CD / SA.

[0007] The method for preparing Pickering emulsion from a β-cyclodextrin / sodium alginate blend of the present invention comprises the following steps:

[0008] Step 1: Take 0.1 g of β-cyclodextrin and add it to the solvent. After it is fully dissolved, add sodium alginate powder and mix thoroughly to obtain β-CD / SA.

[0009] Step 2: Immerse the probe of the high-speed shearing machine (10G) into the β-CD / SA mixed solution, slowly add 10 ml of medium-chain triglyceride (MCT), perform high-speed shearing, and then let it stand at room temperature for 24 h to obtain β-CD / SAPickering emulsion.

[0010] Take out a small amount of the obtained β-CD / SAPickering emulsion and place it on a glass slide. Observe the distribution of oil droplets under a microscope, select the oil droplets with uniform distribution for photography, and finally analyze the particle size of the oil droplets through ImageJ software to draw a conclusion.

[0011] In Step 1, the purity of β-cyclodextrin is 98%, the relative molecular weight is 1134.984, and the density is 1.6 g / cm 3 ; the purity of sodium alginate is 90%.

[0012] In Step 1, the mass concentration of β-cyclodextrin in the β-CD / SA mixed solution is 1%, and the solvent is deionized water.

[0013] In Step 1, the mass ratio of β-cyclodextrin to sodium alginate is 4:0 to 0:4. Specifically, five groups of mixed solutions are prepared by β-cyclodextrin and sodium alginate according to the mass concentration ratios of 4:0, 3:1, 2:2, 1:3, and 0:4 respectively.

[0014] In Step 1, the oil phase ratio of medium-chain triglyceride (MCT) is 50%, and the volume ratio to deionized water is 1:1.

[0015] In Step 2, the specifications of the rotor used for high-speed shearing are 10G, the rotation speed is 16000 rmp, and the shearing duration is 3 min.

[0016] The advantages of the β-CD / SAPickering emulsion prepared by the present invention compared with the pure β-cyclodextrin Pickering emulsion are mainly reflected in:

[0017] 1. The present invention can prepare Pickering emulsion by combining the hydroxyl groups of sodium alginate and β-cyclodextrin.

[0018] 2. The present invention adds sodium alginate, and uses the lubricity of sodium alginate to increase the viscosity of the emulsion to enhance its taste. Description of the Drawings

[0019] Figure 1Microscopic observation diagrams of Examples 1, 2, 3, and 4 of the present invention: β-cyclodextrin:sodium alginate = 4:0 (A); β-cyclodextrin:sodium alginate = 3:1 (B); β-cyclodextrin:sodium alginate = 2:2 (C); β-cyclodextrin:sodium alginate = 1:3 (D); β-cyclodextrin:sodium alginate = 0:4 (E). From Figure 1 It can be seen that as the addition amount of sodium alginate increases, the oil droplets become smaller and the distribution becomes sparser. Thus, it can be seen that the encapsulation efficiency of the mixture for MCT becomes lower. However, when β-cyclodextrin:sodium alginate = 3:1, the distribution of the emulsion is almost the same as that of the pure β-cyclodextrin emulsion, indicating that the emulsion with this ratio has a relatively good encapsulation effect.

[0020] Figure 2 Particle size distribution curves of the mixtures of Examples 1, 2, 3, 4, and 5 of the present invention. From Figure 2 it can be seen that as the addition amount of sodium alginate increases, the particle size of the mixture particles becomes larger, and relatively ideal particle size is obtained when β-cyclodextrin:sodium alginate = 3:1.

[0021] Figure 3 Zeta potentials of the emulsions of Examples 1, 2, 3, 4, and 5 of the present invention. From Figure 3 it can be seen that the Zeta potential of pure β-cyclodextrin is in a relatively unstable range, and the Zeta potentials of β-cyclodextrin:sodium alginate = 2:2, 1:3, and 0:4 are in a relatively stable range, indicating that the fluidity of the emulsion is poor at this time. When β-cyclodextrin:sodium alginate = 3:1, the Zeta potential of the emulsion is between the two, having good fluidity on the basis of stability. Detailed implementation manners

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0023] Example 1:

[0024] The β-CD / SAPickering emulsion was prepared in the following steps in this example:

[0025] 1. Take 0.1 g of β-cyclodextrin and add it to 10 ml of deionized water. After sufficient stirring, a mixed solution with β-CD:SA of 4:0 was prepared;

[0026] 2: Add 10 ml (50% wt) of medium-chain triglyceride (MCT) to a beaker. Under a high-speed shearer, shear at 16,000 rpm for 3 min and let it stand for 24 h to obtain the final Pickering emulsion;

[0027] 3: Take out a small amount of the emulsion obtained in step 2 and put it on a glass slide, observe the distribution of oil droplets under a microscope, select evenly distributed oil droplets to take pictures, and analyze the particle size of the oil droplets using ImageJ software; then measure the Zeta potential of the obtained emulsion and finally draw a conclusion.

[0028] The β-CD / SA Pickering emulsion prepared in this example was tested under a microscope. Figure 1 As shown in Figure 1, it can be seen that the oil droplets are evenly distributed on the glass slide; the particle size distribution of the emulsion is as follows Figure 2 The Zeta potential variation trend is shown in Figure 3 shown.

[0029] Embodiment 2:

[0030] This example prepares β-CD / SA Pickering emulsion according to the following steps:

[0031] 1. Take 0.075g of β-cyclodextrin and 0.025g of sodium alginate and add them into 10ml of deionized water. After stirring thoroughly, a mixed solution of β-CD:SA is prepared in a ratio of 3:1.

[0032] 2: Add 10 ml (50% wt) of medium chain triglyceride (MCT) into a beaker, shear at 16000 rpm for 3 min under a high-speed shearing machine, and let stand for 24 h to obtain the final Pickering emulsion;

[0033] 3: Take out a small amount of the emulsion obtained in step 2 and put it on a glass slide, observe the distribution of oil droplets under a microscope, select evenly distributed oil droplets to take pictures, and analyze the particle size of the oil droplets using ImageJ software; then measure the Zeta potential of the obtained emulsion to draw a conclusion.

[0034] The β-CD / SA Pickering emulsion prepared in this example was tested under a microscope. Figure 1 As shown in Figure 1, it can be seen that the oil droplets are evenly distributed on the glass slide; the particle size distribution of the emulsion is as follows Figure 2 The Zeta potential variation trend is shown in Figure 3 shown.

[0035] Embodiment 3:

[0036] This example prepares β-CD / SA Pickering emulsion according to the following steps:

[0037] 1. Take 0.05g of β-cyclodextrin and 0.05g of sodium alginate and add them into 10ml of deionized water. After stirring thoroughly, a mixed solution of β-CD:SA is prepared with a ratio of 2:2.

[0038] 2: Add 10 ml (50% wt) of medium-chain triglyceride (MCT) into a beaker. Under a high-speed shear mixer, shear it at 16,000 rpm for 3 min and let it stand for 24 h to obtain the final Pickering emulsion;

[0039] 3: Take a small amount of the emulsion obtained in step 2 and place it on a glass slide. Observe the oil droplet distribution under a microscope, select the oil droplets with uniform distribution for taking pictures, and analyze the oil droplet particle size through ImageJ software; then measure the Zeta potential of the obtained emulsion to draw a conclusion.

[0040] Perform a microscope test on the β-CD / SA Pickering emulsion prepared in this example as Figure 1 shown. It can be seen that the oil droplets are evenly distributed on the glass slide; the particle size distribution of the emulsion is as Figure 2 shown; the changing trend of the Zeta potential is as Figure 3 shown.

[0041] Example 4:

[0042] Prepare the β-CD / SA Pickering emulsion in this example according to the following steps:

[0043] 1. Take 0.025 g of β-cyclodextrin and 0.075 g of sodium alginate and add them into 10 ml of deionized water. After stirring thoroughly, prepare a mixed solution with a β-CD:SA ratio of 1:3;

[0044] 2: Add 10 ml (50% wt) of medium-chain triglyceride (MCT) into a beaker. Under a high-speed shear mixer, shear it at 16,000 rpm for 3 min and let it stand for 24 h to obtain the final Pickering emulsion;

[0045] 3: Take a small amount of the emulsion obtained in step 2 and place it on a glass slide. Observe the oil droplet distribution under a microscope, select the oil droplets with uniform distribution for taking pictures, and analyze the oil droplet particle size through ImageJ software; then measure the Zeta potential of the obtained emulsion to draw a conclusion.

[0046] Perform a microscope test on the β-CD / SA Pickering emulsion prepared in this example as Figure 1 shown. It can be seen that the oil droplets are evenly distributed on the glass slide; the particle size distribution of the emulsion is as Figure 2 shown; the changing trend of the Zeta potential is as Figure 3 shown.

[0047] Example 5:

[0048] Prepare the β-CD / SA Pickering emulsion in this example according to the following steps:

[0049] 1. Take 0.1 g of sodium alginate and add it to 10 ml of deionized water. After stirring thoroughly, a mixed solution with a β-CD:SA ratio of 0:4 is prepared.

[0050] 2. Add 10 ml (50% wt) of medium-chain triglyceride (MCT) to a beaker. Under a high-speed shearer, shear it at 16,000 rpm for 3 min and let it stand for 24 h to obtain the final Pickering emulsion.

[0051] 3. Take a small amount of the emulsion obtained in step 2 and place it on a glass slide. Observe the oil droplet distribution under a microscope. Select oil droplets with uniform distribution for taking pictures. Analyze the oil droplet diameter through ImageJ software, and then measure the Zeta potential of the obtained emulsion to draw a conclusion.

[0052] The β-CD / SA Pickering emulsion prepared in this example was subjected to a microscope test as Figure 1 shown. It can be seen that the oil droplets are evenly distributed on the glass slide; the particle size distribution of the emulsion is as Figure 2 shown; the changing trend of the Zeta potential is as Figure 3 shown.

Claims

1. A method for preparing Pickering emulsion with β-cyclodextrin / sodium alginate blend, characterized in that: First, β-cyclodextrin is fully dissolved in a solvent, and then sodium alginate is added and mixed well with it. Sodium alginate can combine with the hydroxyl groups of β-cyclodextrin to improve its encapsulation efficiency, and can also increase the viscosity of the emulsion to enhance its taste, including the following steps: Step 1: Take β-cyclodextrin and add it to a solvent. After it is fully dissolved, add sodium alginate powder. After mixing well, obtain a β-CD / SA mixed solution; Step 2: Immerse the probe of a high-speed shearer into the β-CD / SA mixed solution, slowly add medium-chain triglyceride, perform high-speed shearing, and then let it stand at room temperature for 24 h to obtain a β-CD / SA Pickering emulsion; In Step 1, the mass concentration of β-cyclodextrin in the β-CD / SA mixed solution is 1%, and the solvent is deionized water; In Step 1, the volume ratio of medium-chain triglyceride to the solvent is 1:1; In Step 1, the mass ratio of β-cyclodextrin to sodium alginate is 3:1; In Step 2, the specifications of the rotor used for high-speed shearing are 10G, the rotation speed is 16000 rpm, and the shearing duration is 3 min.

2. According to the method described in claim 1, characterized in that: In Step 1, the purity of β-cyclodextrin is 98%, the relative molecular weight is 1134.984, and the density is 1.6 g / cm 3 ; the purity of sodium alginate is 90%.

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