CN113368052B

CN113368052B - Multiple emulsion of soyasaponin and preparation method thereof

Info

Publication number: CN113368052B
Application number: CN202110595995.0A
Authority: CN
Inventors: 朱力杰; 许杨杨; 刘悦; 宁淼; 赵国秀; 李赛楠; 刘秀英; 杨立娜; 王胜男; 刘贺
Original assignee: Bohai University
Current assignee: Bohai University
Priority date: 2021-05-29
Filing date: 2021-05-29
Publication date: 2022-12-30
Anticipated expiration: 2041-05-29
Also published as: CN113368052A

Abstract

A multiple emulsion of soyasaponin and its preparation method, said multiple emulsion is water-in-oil-in-water structure, contain isolated soy protein and phosphate buffer solution in its external water phase; the oil phase comprises polyglycerol polyricinoleate and corn oil; the inner water phase contains soyasaponin and phosphate buffer solution; the mass concentration of the soybean protein isolate in the external water phase is 1-3%; the mass concentration of polyglycerol polyricinoleate in the oil phase is 3%; the mass concentration of the soyasaponin in the internal water phase is 1%. Mixing the oil phase and the internal water phase, and homogenizing to obtain W/O emulsion; and mixing the external water phase with the W/O emulsion, and homogenizing to obtain the multiple soybean saponin emulsion with the slow release function. The advantages are that: the modified soybean saponin tablet has the advantages of good stability, uniform dispersion, effective embedding of the soybean saponin, controlled release of the soybean saponin, avoidance of loss of activity due to structural damage of the soybean saponin under the action of gastric acid and the like after being ingested, capability of shielding bad flavor of the soybean saponin, and good palatability.

Description

Soybean saponin multiple emulsion and preparation method thereof

Technical Field

The invention relates to a soyasaponin multiple emulsion and a preparation method thereof.

Background

The soyasaponin belongs to pentacyclic triterpenoid oleanane type saponin, is the most important micromolecule functional component in soybean, and is rich in soybean meal which is a byproduct of soybean oil extraction. The soyasaponin can activate an Nrf2/HO-1 signal path in a body, so that various antioxidant mechanisms of the body are excited to generate, and various physiological functions of the body are realized; it has an enhancing effect on T cells, especially T cell function enhancement, and can increase IL-2 secretion for protecting survival and reproduction of T cells; and T cells are promoted to generate lymphokines, the differentiation of trap-killing cells NK is enhanced, the activity of LAK is improved, and therefore organisms show stronger immune functions. However, soyasaponin has certain irritation and bitter taste, and is not suitable for large-amount ingestion at one time; meanwhile, as a glycoside compound, the glycoside compound may be degraded by gastric acid and the like after being ingested, thereby affecting the exertion of the physiological activity.

Common saponin emulsions are mostly oil-in-water (O/W) and water-in-oil (W/O) types. Because the saponin has an amphiphilic structure and is relatively hydrophilic, the oil-in-water type saponin emulsion cannot effectively embed the saponin and is difficult to shield the bad flavor of the saponin; and the stability and the dispersibility of the water-in-oil saponin emulsion are poor.

Disclosure of Invention

The invention aims to provide the multiple emulsion of the soyasaponin with good stability and uniform dispersion and the preparation method thereof, which can effectively embed the soyasaponin, have a controlled release effect on the soyasaponin, avoid the loss of activity of the soyasaponin due to the damage of the structure under the action of gastric acid and the like after being ingested, can shield the bad flavor of the soyasaponin and have good palatability.

The technical scheme of the invention is that

A soyasaponin multiple emulsion is characterized in that: the multiple emulsion is of a water-in-oil-in-water structure, and the external water phase of the multiple emulsion contains isolated soy protein and phosphate buffer solution; the intermediate oil phase contains polyglycerol polyricinoleate and corn oil; the inner water phase contains soyasaponin and phosphate buffer solution; the mass concentration of the soybean protein isolate in the external water phase is 1-3%; the mass concentration of the polyglycerol polyricinoleate in the intermediate oil phase is 3%; the mass concentration of the soyasaponin in the internal water phase is 1%.

Further, the mass ratio of the intermediate oil phase to the inner water phase is 7; the mass ratio of the external aqueous phase to the total mass of the intermediate oil phase and the internal aqueous phase is 6 or 5.

Furthermore, the purity of the soyasaponin is more than 90%, and the mass content of the protein in the isolated soy protein is more than 80%.

Further, the phosphate buffer solution is a sodium dihydrogen phosphate buffer solution with a pH of 7.0.

Preparing a phosphate buffer solution: 1.1098g of disodium hydrogen phosphate dodecahydrate and 0.2964g of sodium dihydrogen phosphate dihydrate were dissolved in a 500ml volumetric flask, and the pH was 7.0.

The preparation method of the soybean saponin multiple emulsion comprises the following steps:

1) Dissolving soyasaponin in phosphate buffer solution to obtain 1% inner water phase;

2) Dissolving polyglycerol polyricinoleate in corn oil to prepare an oil phase with the polyglycerol polyricinoleate concentration of 3%;

3) Mixing and homogenizing according to the mass ratio of the oil phase to the internal water phase of 7;

4) Dissolving the isolated soy protein in phosphate buffer solution to prepare an external water phase with the mass fraction of the isolated soy protein being 2%;

5) Mixing and homogenizing the external water phase and the W/O emulsion obtained in the step 3) according to the mass ratio of 6.

Further, the polyglycerol polyricinoleate is dissolved in the corn oil, and is heated and stirred for 30min at 50 ℃.

Further, when the oil phase and the internal aqueous phase were mixed, homogenization was carried out at 18000r/min for 4min by a high-speed homogenizer, and then high-pressure homogenization was carried out at 60MPa by a high-pressure homogenizer.

Further, when the external aqueous phase and the W/O emulsion were mixed, they were homogenized at 7000r/min for 2min in a high-speed homogenizer, and then homogenized at 10MPa in a high-pressure homogenizer, followed by high-pressure homogenization.

The invention has the beneficial effects that:

the water-in-oil-in-water multiple emulsion prepared by the method has controllable conditions, stable structure, proper particle size and good dispersibility, is stable when placed for 15 days at room temperature, has no layering phenomenon, is moderate in viscosity and good in palatability; the soybean saponin in the soybean saponin multiple emulsion is only released by 65.32% in 24h, and the release rate reaches 87.11% in 48h and is basically not changed any more, and the release rate is in a constant slow trend. The emulsion realizes the uniform release of soyasaponin within 24h, and has sustained release function within 24h to 48 h. After the soyasaponin is coated, the release of the soyasaponin functional substances is obviously slowed down, which shows that the soyasaponin multiple emulsion prepared by the invention has a slow release effect; and the damage of the soybean saponin to the in-vivo environment such as gastric acid and the like is avoided, and the bad flavor of the soybean saponin is shielded.

Drawings

The invention is further described with reference to the following figures and examples:

fig. 1 is a flow chart of the preparation of the soyasaponin multiple emulsion with a slow release function of the invention;

fig. 2 is a graph showing stability power index values of multiple emulsions of soyasaponin with sustained release function, which are composed of soyasaponin with different concentrations in example 1 and comparative examples 1 to 3 of the present invention;

FIG. 3 is a viscosity number curve diagram of multiple aqueous emulsions of soyasaponin with sustained release function, which are composed of different concentrations of soyasaponin in example 1 and comparative examples 1 to 3 of the present invention;

FIG. 4 is a diagram of multiple aqueous emulsions of soyasaponin with sustained release function, which are composed of different soyasaponin concentrations in example 1 and comparative examples 1-3 of the present invention (A is fresh emulsion; B is 15 days after emulsion);

FIG. 5 is a graph plotting the in vitro release rates of an aqueous solution of soyasaponin 1%;

FIG. 6 is a graph of stability power index values for water-in-oil-in-water emulsions of examples 2-4, comparative example 4 at different concentrations of soy protein isolate;

FIG. 7 is a graph of viscosity values for water-in-oil-in-water emulsions formed with different concentrations of soy protein isolate of examples 2-4 and comparative example 4;

FIG. 8 is a schematic representation of water-in-oil-in-water emulsions formed from different concentrations of soy protein isolate in examples 2-4 and comparative example 4 (A is fresh emulsion; B is 15 days post-emulsion).

Detailed Description

The invention discloses a soyasaponin multiple emulsion with a slow release function and a preparation method thereof, wherein the mass concentration of soyasaponin in an internal water phase is 1%, and a solvent is a phosphate buffer solution with pH = 7; the mass concentration of the polyglycerol polyricinoleate in the intermediate oil phase is 3 percent, and the solvent is corn oil; the mass concentration of the isolated soy protein in the external water phase is 1-3%, and the solvent is phosphate buffer solution with pH =7. Wherein, phosphate buffer solution preparation: 1.1098g of disodium hydrogen phosphate dodecahydrate and 0.2964g of sodium dihydrogen phosphate dihydrate were dissolved in a 500ml volumetric flask, and the pH was 7.0. The specific operation steps are as follows: 1) Dissolving 1g of soyasaponin in 99g of phosphate buffer solution (pH = 7.0) as an inner aqueous phase; 2) Dissolving 3g of polyglycerol polyricinoleate in 97g of corn oil, heating and stirring at 50 ℃ for 30min to prepare an oil phase; 3) According to the mass ratio of the oil phase to the internal water phase of 7:3, mixing, homogenizing for 4min at 18000r/min by a high-speed homogenizer, and then homogenizing at 60Mpa by a high-pressure homogenizer to obtain W/O emulsion; 4) Then dissolving 1g-3g of soy protein isolate in 97g-99g of phosphate buffer solution as an external water phase with the mass of 100 g; 5) The mass ratio of the external aqueous phase to the W/O emulsion obtained in the step 3) is 6:4 or 5:5, mixing, homogenizing at 7000r/min for 2min with a high-speed homogenizer, homogenizing at 10Mpa with a high-pressure homogenizer, and homogenizing at high pressure to obtain the soyasaponin multiple emulsion with slow release function.

The present invention will be further explained with reference to specific examples, but is not limited to the scope of the present invention.

The phosphate buffer solution referred to in the following examples and comparative examples is sodium dihydrogen phosphate buffer solution with pH 7.0, which is specifically formulated as follows: 1.1098g of disodium hydrogen phosphate dodecahydrate and 0.2964g of sodium dihydrogen phosphate dihydrate are dissolved in a 500mL volumetric flask and added with water to a constant volume to prepare the sodium phosphate dihydrate solution with a pH of 7.0. The purity of the used raw material soyasaponin is more than 90%, the mass content of the protein in the soybean protein isolate is more than 80%, and the same batch of products are used for ensuring the accuracy of the parallel test result.

Example 1

Table 1 shows the formula of the main composition of example 1, and the mass fractions of the substances are as follows:

	emulsion composition	Mass concentration of each substance
			Internal aqueous phase	Soyasaponin-phosphate buffer solution	1％
Oil phase	Polyglycerol polyricinoleate-corn oil	3％
			External water phase	Isolated soy protein-phosphate buffer solution	2％

TABLE 1 EXAMPLE 1 composition formulation for water-in-oil-in-water emulsion

The procedure of this example, as shown in FIG. 1, was as follows:

(1) 1g of soybean saponin was dissolved in 99g of phosphate buffer solution (pH = 7.0) as an inner aqueous phase.

(2) Dissolving 3g of polyglycerol polyricinoleate in 97g of corn oil, and heating and stirring at 50 ℃ for 30min to prepare an oil phase.

(3) Mixing the oil phase and the inner water phase according to the mass ratio of 7, homogenizing for 4min at 18000r/min by a high-speed homogenizer, and then homogenizing the homogenized crude emulsion at high pressure under the pressure of 60MPa to obtain the final W/O emulsion.

(4) 2g of soy protein isolate was dissolved in 98g of phosphate buffer solution (pH = 7.0) as an external aqueous phase.

(5) Mixing the external water phase with the W/O emulsion at a mass ratio of 6. The particle size and width of the multiple emulsion were measured using a laser particle size distribution analyzer, and the results are shown in table 2.

TABLE 2

	Sample name	D ₄₃ (μm)	D ₃₂ (μm)	Span
					Example 1	1% Soyasaponin	10.500±0.300 ^c	3.347±0.053 ^c	2.836±0.201 ^b

Comparative example 1, the mass fraction of soyasaponin in the internal aqueous phase was 0.5%, and the remaining composition and preparation method were the same as in example 1.

(1) 0.5g of soyasaponin was dissolved in 99.5g of phosphate buffer solution (pH = 7.0) as an inner aqueous phase.

(2) An oil phase was prepared by dissolving 3g of polyglycerol polyricinoleate in 97g of corn oil and heating and stirring at 50 ℃ for 30min.

(3) Mixing the oil phase and the inner water phase according to the mass ratio of 7.

(5) Mixing the external water phase with the W/O emulsion at a mass ratio of 6, homogenizing at 7000r/min for 2min with a high-speed homogenizer, and homogenizing at 10MPa with a high-pressure homogenizer to obtain the soyasaponin multiple emulsion with slow release function.

Comparative example 2, the mass fraction of soyasaponin in the inner aqueous phase was 2%, and the remaining composition and preparation method thereof were the same as in example 1.

(1) 5g of soybean saponin was dissolved in 98g of phosphate buffer solution (pH = 7.0) as an inner aqueous phase.

Comparative example 3, the mass fraction of soyasaponin in the inner water phase was 3%, and the remaining composition and the preparation method thereof were the same as in example 1.

(1) 3g of soybean saponin was dissolved in 97g of phosphate buffer solution (pH = 7.0) as an inner aqueous phase.

1. Stability power index and stability comparison of soyasaponin multiple emulsions with different concentrations

Fig. 2 shows stability power index values of multiple emulsions of water-in-oil-in-water soybean saponins composed of soybean saponins at different concentrations in example 1 and comparative examples 1 to 3 of the present invention. And (3) adopting a multiple light scattering instrument to carry out standing vertical scanning on the sample, and automatically calculating to obtain the stability dynamic index. The larger the numerical value of the stability kinetic index is, the worse the stability of the multiple emulsion of the soyasaponin is. As can be seen from fig. 2, the stability dynamic index of the multiple soybean saponin emulsion shows a trend of increasing with the time, and the stability dynamic index of the multiple soybean saponin emulsion increases with the increase of the concentration of the soybean saponin under the same standing time, which indicates that the stability of the emulsion is slightly reduced with the time of standing.

FIG. 4 is a graph of different concentrations of soyasaponin to form a water-in-oil-in-water emulsion. From fig. 4 (a), it can be seen that the fresh emulsions prepared in example 1 and comparative examples 1,2 and 3 all exhibited milky white color, good stability and no saponin was precipitated; FIG. 4 (B) shows that after 15d, no delamination was observed between the two emulsions of example 1 and comparative example 1; the results of the two emulsions of comparative examples 2 and 3, in which significant demixing occurred and a little precipitation was observed at the bottom of the bottle, indicate that the emulsions of comparative examples 2 and 3 had poor stability.

Combining the stability kinetics index of fig. 2 and the visual observation result of fig. 4, the emulsion prepared in example 1 of the present invention, i.e., at a soyasaponin concentration of 1%, has good stability.

2. Viscosity variation of multiple emulsions of soyasaponin at different concentrations

The viscosity of each set of water-in-oil-in-water emulsions was measured using a rheometer and the results are shown in table 3 and figure 3.

TABLE 3 viscosity number of emulsions made up of different soyasaponin concentrations

	Concentration of Soyasaponin	K*10 ^-3 (Pa·s)	n	R ²
					Comparative example 1	0.5％	9.627±0.414 ^c	0.885±0.007 ^a	0.999±0.001 ^b
Example 1	1％	6.110±0.853 ^b	0.926±0.024 ^b	0.997±0.001 ^a
					Comparative example 2	2％	4.080±0.340 ^a	0.967±0.012 ^c	1.000±0.000 ^b
Comparative example 3	3％	4.050±0.000 ^a	0.973±0.003 ^c	1.000±0.000 ^b

Table 3 and fig. 3 show the viscosity change of the emulsions of example 1 and comparative examples 1 to 3 for different concentrations of soyasaponin. As can be seen from Table 3 and FIG. 3, the viscosity of the emulsion is moderate in the case of example 1, and poor in the taste in the case of comparative example 1; the viscosities of comparative examples 2 and 3 were slightly lower. The soybean saponin multiple emulsion system has shear thinning behavior.

Example 2

(4) 1g of soy protein isolate was dissolved in 99g of phosphate buffer solution (pH = 7.0) as an external aqueous phase.

(5) Mixing the external water phase with W/O emulsion at a mass ratio of 5, homogenizing at 7000r/min for 2min with a high-speed homogenizer, and homogenizing at 10MPa with a high-pressure homogenizer to obtain the soyasaponin multiple emulsion with slow release function. The particle size and width of the multiple emulsion of soyasaponin were measured using a laser particle size distribution analyzer, and the results are shown in table 4.

Example 3

Example 4

(4) 3g of soy protein isolate was dissolved in 97g of phosphate buffer solution (pH = 7.0) as an external aqueous phase.

(5) Mixing the external water phase with W/O emulsion at a mass ratio of 5, homogenizing at 7000r/min for 2min with a high-speed homogenizer, and homogenizing at 10MPa with a high-pressure homogenizer to obtain the soyasaponin multiple emulsion with slow release function. The particle size and width of the soyasaponin multiple emulsion were measured using a laser particle size distribution analyzer, and the results are shown in table 4.

Table 4 examples 2-4 multiple aqueous emulsion particle size table

	Concentration of isolated soy protein	D ₄₃ (μm)	D ₃₂ (μm)	Span
					Example 2	1% isolated soy protein	6.493±0.136 ^b	3.012±0.070 ^b	1.798±0.027 ^c
Example 3	2% isolated soy protein	5.834±0.002 ^a	2.900±0.008 ^a	1.650±0.002 ^a
					Example 4	3% isolated soy protein	5.755±0.036 ^a	2.905±0.033 ^a	1.655±0.017 ^a

As can be seen from Table 4, the soybean saponin multiple emulsions of examples 2-4 of the present invention have very small and moderate particle size, and the particle size ranges from 5.755 μm to 6.493 μm.

Comparative example 4

(4) 0.5g of soy protein isolate was dissolved in 99.5g of phosphate buffer solution (pH = 7.0) as an external aqueous phase.

(5) Mixing the external water phase with W/O emulsion at a mass ratio of 5, homogenizing at 7000r/min for 2min with a high-speed homogenizer, and homogenizing at 10MPa with a high-pressure homogenizer to obtain the soyasaponin multiple emulsion with slow release function.

FIG. 6 is a graph of the stability power index values of multiple emulsions of soybean saponins composed of different concentrations of isolated soybean proteins in examples 2-4 and comparative example 4. As can be seen from fig. 6, as the concentration of the soy protein isolate increases, the stability dynamic index of the emulsion tends to decrease, and the stability of the emulsion increases, while comparative example 4 is less stable than examples 2, 3 and 4.

Table 5 and fig. 7 the results of the multiple emulsion assay for soyasaponin were constructed with different concentrations of soy protein isolate in examples 2-4 and comparative example 4.

TABLE 5 Effect of different soy protein isolate concentrations on the viscosity of water-in-oil-in-water emulsions

	Concentration of isolated soy protein	K(Pa·s)	n	R ²
					Comparative example 4	0.5% isolated soy protein	0.011±0.001 ^a	0.843±0.012 ^c	0.998±0.000 ^a
Example 2	1% isolated soy protein	0.029±0.005 ^b	0.731±0.025 ^b	0.999±0.001 ^b
					Example 3	2% isolated soy protein	0.032±0.004 ^b	0.723±0.018 ^ab	0.999±0.000 ^b
Example 4	3% isolated soy protein	0.043±0.003 ^c	0.696±0.010 ^a	0.999±0.000 ^b

The results in table 5 and figure 7 show that as the concentration of soy protein isolate increases, the viscosity of the emulsion increases accordingly. Where the viscosity of comparative example 4 is too low, the viscosities of examples 2, 3 are relatively close, and the viscosity of example 4 is slightly greater than examples 2, 3, but still acceptable.

FIG. 8 is a visual photograph of different soy protein isolate concentrations making up a water-in-oil-in-water emulsion. As can be seen from fig. 8 (a), the freshly prepared emulsion appeared uniformly milky white, and no precipitation of precipitate was observed; and FIG. 8 (B) shows that comparative example 4 shows a severe destabilization stratification after standing for 15d, indicating that 0.5% of the soy protein isolate does not meet the requirements for stable emulsion. The results of examples 2, 3 and 4 show that when the mass fraction of the isolated soy protein is 1-3%, a stable water-in-oil-in-water emulsion of the soyasaponin can be prepared, and the effect of example 3 is optimal.

3. Example 1 sustained Release function of Soyasaponin

The results of comparing the in vitro release rates of the aqueous solution of soyasaponin and the soyasaponin multiple emulsion having a sustained-release function of example 1 of the present invention are shown in fig. 5. The soyasaponin multiple emulsion with sustained release function prepared in this example 1 was selected to perform in vitro release experiments. Placing 5mL of soybean saponin multiple emulsion with slow release function and 1% soybean saponin aqueous solution in dialysis bag, placing into a conical flask containing 100mL of release medium (ultrapure water), shaking at 37 deg.C in constant temperature shaking table at low speed, and taking 1mL of sample at certain time intervals (0.5, 1,2,4,8, 12, 24, 36, 48 h) to supplement the same volume of release medium. The content of the soyasaponin in the sample is analyzed by adopting a vanillin-glacial acetic acid method. The results in fig. 5 show that the release of the soyasaponin in the ultrapure water is completed within about 5 hours, while the release rate of the soyasaponin in the water-in-oil-in-water emulsion is only 65.32% within 24 hours, and reaches 87.11% within 48 hours, and basically does not change any more, and the release rate is in a uniform and slow trend compared with the release rate of the control group. The results show that the emulsion realizes the uniform release of the soyasaponin within 24 hours and has the slow release function within the range of 24 hours to 48 hours.

The present invention is not limited to the above embodiments, but various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A soyasaponin multiple emulsion is characterized in that: the multiple emulsion is of a water-in-oil-in-water structure, and the external water phase of the multiple emulsion contains isolated soy protein and phosphate buffer solution; the intermediate oil phase contains polyglycerol polyricinoleate and corn oil; the inner water phase contains soyasaponin and phosphate buffer solution; the multiple emulsion has a slow release function on the soyasaponin, and the mass concentration of the soybean protein isolate in a water phase is 1-3%; the mass concentration of the polyglycerol polyricinoleate in the intermediate oil phase is 3%; the mass concentration of the soyasaponin in the internal water phase is 1%;

the mass ratio of the intermediate oil phase to the inner water phase is 7; the mass ratio of the external aqueous phase to the total mass of the intermediate oil phase and the internal aqueous phase is 6 or 5.

2. A multiple emulsion of soyasaponin according to claim 1, which is characterized in that: the purity of the soyasaponin is more than 90%, and the mass content of the protein in the soybean protein isolate is more than 80%.

3. A multiple emulsion of soyasaponin according to claim 1 characterized in that: the phosphate buffer solution is a sodium dihydrogen phosphate buffer solution with the pH value of 7.0.

4. A method for preparing a multiple emulsion of soyasaponin as claimed in claim 1, which is characterized by:

the method comprises the following steps:

1) Dissolving soyasaponin in phosphate buffer solution to obtain an internal water phase with soyasaponin mass fraction of 1%;

5. A method for preparing a multiple emulsion of soybean saponin as defined in claim 4, which comprises: dissolving polyglycerol polyricinoleate in corn oil, and heating and stirring at 50 deg.C for 30min.

6. A method for preparing a multiple emulsion of soybean saponin as defined in claim 4, which comprises: mixing the oil phase and the internal water phase, homogenizing at 18000r/min for 4min with a high-speed homogenizer, and homogenizing at 60MPa with a high-pressure homogenizer.

7. A method for preparing a multiple emulsion of soybean saponin as defined in claim 4, which comprises: mixing the external water phase with W/O emulsion, homogenizing at 7000r/min for 2min with high speed homogenizer, homogenizing with high pressure homogenizer at 10MPa, and homogenizing under high pressure.