CN115558659B - Lactobacillus plantarum embedding emulsion and preparation method and application thereof - Google Patents

Abstract

The invention discloses a plant lactobacillus embedding emulsion and its preparation method and application. The preparation method comprises: dry mixing casein (animal protein) and pea protein isolate (vegetable protein) to prepare a mixed protein solution; using protein and polysaccharide The electrostatic interaction between the mixed protein-gellan gum complex was prepared; the Lactobacillus plantarum powder was dispersed in palm oil; the oil phase containing the bacterial powder was mixed with the solution containing the mixed protein-gellan gum complex, using high Emulsified by a shear homogenizer to obtain a mixed protein-gellan gum emulsion. The emulsion prepared by the invention has good encapsulation effect, can be stored stably at 4 DEG C, and has excellent heat resistance and gastric digestion resistance.

Description

A kind of embedded lactobacillus plantarum emulsion and its preparation method and application

Technical Field

The invention relates to an embedded lactobacillus plantarum emulsion and a preparation method and application thereof, belonging to the technical field of microorganisms.

Background Art

Probiotics are beneficial live microorganisms that can protect gastrointestinal health and prevent/treat cancer by regulating the host's intestinal flora, thereby affecting metabolism and immunity. For probiotics to have a beneficial effect on health, the viable cells must reach at least 10 ⁷ CFU/mL before passing through the gastrointestinal tract to reach the colon. However, there are some challenges in the application of probiotics in food, including their ability to survive during processing and long-term storage, as well as their ability to survive in acidic conditions and digestive juices. Therefore, some methods must be used to improve the survival rate of probiotics in adverse environments.

Encapsulation of probiotics can improve the stability of probiotics. Suitable encapsulation wall materials can maintain the stability of probiotics in adverse environments and regulate the location and rate of probiotic release. Emulsification is widely used to encapsulate bioactive substances because it is easy to design and prepare. So far, the reported emulsions containing bioactive substances are mainly produced by synthetic surfactants. However, synthetic surfactants are slightly toxic, and it is of great significance to prepare emulsions with natural polymers (proteins, polysaccharides). Many food proteins (soy protein, whey protein, casein) are used as emulsifiers, but only protein-stabilized emulsifiers are sensitive to environmental factors such as temperature, pH value and salt, and are prone to aggregation, flocculation and Ostwald ripening. Therefore, there is an urgent need for an encapsulated Lactobacillus plantarum emulsion that better retains the activity of probiotics and improves the encapsulation effect, as well as its preparation method and application.

Summary of the invention

The purpose of the present invention is to provide a method for preparing an embedded Lactobacillus plantarum emulsion, which can better retain the activity of probiotics, improve the encapsulation effect, can be stably stored at 4°C, and has excellent heat resistance and gastric digestion resistance.

Meanwhile, the invention provides an embedded plant lactobacillus emulsion, which has good stability and high viable bacteria count.

At the same time, the present invention provides an application of an embedded Lactobacillus plantarum emulsion in food, and the food is used for regulating the intestinal flora of a host and protecting the health of the gastrointestinal tract.

Meanwhile, the invention provides a food comprising the embedded Lactobacillus plantarum emulsion.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

A method for preparing an embedded Lactobacillus plantarum emulsion comprises the following steps:

Step 1: Mix casein powder and pea protein isolate powder in a mass ratio of 2:1 and disperse them in 100 mL PBS. The concentration of the casein powder is 20-60 g/L. Stir at 400-700 r/min for 2-5 hours at 40-60° C. and then put them in a refrigerator for hydration for 8-16 hours to obtain a mixed protein solution.

Step 2, dispersing 0.4-2 g of gellan gum powder in 100 mL of deionized water, stirring at 400-700 r/min at 40-50° C. for 0.5-3 h to obtain a gellan gum solution;

Step 3, mixing the mixed protein solution and the gellan gum solution in a volume ratio of 1:1, stirring at 40-60° C. and 700-900 r/min for 2-4 hours to obtain a mixed protein-gellan gum complex solution;

Step 4: melt the palm oil for later use, add the plant lactobacillus powder into the palm oil at a ratio of 1:40, 1:20, 1:10, 1:5, or 1:2, and stir at a speed of 300-800 r/min until uniformly dispersed to obtain an oil phase;

Step 5, mixing the oil phase and the mixed protein-gellan gum complex solution at a volume ratio of 1:4 to obtain a mixed solution;

Step six, emulsifying the mixed solution at 8000-16000 rpm for 2-6 minutes to obtain a mixed protein-gellan gum emulsion.

The deposit number of Lactobacillus plantarum is CICC6002.

PBS is 0.01 M, pH is 7.0-7.2; the temperature of the refrigerator is 4°C.

The pH of deionized water is 6.8-7.2.

The melting point of palm oil is 40-60℃.

In the mixed protein-gellan gum complex solution, the concentrations of casein, pea protein isolate and gellan gum are 20 g/L, 10 g/L and 8 g/L, respectively.

The embedded Lactobacillus plantarum emulsion obtained by the preparation method of the invention.

Application of encapsulated Lactobacillus plantarum emulsion in food.

Food is used to regulate the host's intestinal flora and protect gastrointestinal health.

A food comprising the Lactobacillus plantarum emulsion of the present invention.

The present invention has the following beneficial effects:

The invention discloses an embedded Lactobacillus plantarum emulsion and a preparation method and application thereof, wherein casein (animal protein) and pea protein isolate (plant protein) are dry-mixed to prepare a mixed protein solution; a mixed protein-gellan gum complex is prepared by utilizing the electrostatic interaction between protein and polysaccharide; Lactobacillus plantarum powder is dispersed in palm oil; and an oil phase containing the powder and a solution containing the mixed protein-gellan gum complex are emulsified by using a high shear homogenizer. The composite emulsion prepared by the invention has a good encapsulation effect, can be stably stored at 4°C, and has excellent heat resistance and gastric digestion resistance.

The polysaccharide in the present invention can improve the stability of the protein emulsion under storage and simulated gastrointestinal conditions, as well as the bioavailability of the contained substances. Gellan gum can resist acidic environments, and also has the characteristics of being resistant to thermal stress and not easily hydrolyzed by enzymes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a diagram showing the appearance of the mixed protein-gellan gum emulsion of the present invention after being stored at 4° C. for 21 days;

FIG2 is a diagram showing the appearance of the mixed protein-gellan gum emulsion of the present invention after storage at 4° C. and 25° C. for 21 days;

FIG3 is a cryo-scanning electron micrograph of the Lactobacillus plantarum embedding emulsion.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the accompanying drawings.

The activated Lactobacillus plantarum was inoculated into 1L MRS medium and cultured at 37°C for 12h. The bacterial sludge was collected by centrifugation at 6000rpm for 10min, and the bacterial sludge was repeatedly washed three times with 14% skim milk powder and resuspended in 100mL skim milk powder. The resuspended sample was freeze-dried for 24h to obtain Lactobacillus plantarum powder; the Latin name of the Lactobacillus plantarum is Lactobacillus plantarum, the preservation unit is China Industrial Microorganism Culture Collection Management Center (CICC for short), the preservation number is CICC6002, and the inventor purchased it through the culture collection center.

The present invention includes the following reagents as shown in Table 1:

Table 1 Reagents

Example 1

Mix casein (animal protein) and pea protein isolate (plant protein) in a mass ratio of 1:1, 2:1, and 5:1, respectively, and dissolve in PBS (0.01M, pH 7.0), stir at 500r/min at 45°C for 3h, and then put it in a 4°C refrigerator for hydration for 12h to prepare a mixed protein (3%, w/v) stock solution. Add 0.5g of bacterial powder to 20mL of palm oil melted at 50°C and stir at 800r/min until evenly dispersed. Emulsify 20mL of oil phase (palm oil containing bacterial powder) and 80mL of mixed protein solution using a high shear homogenizer at 12000rpm for 4min.

Comparative Example 1

Dissolve casein or pea protein isolate in PBS (0.01M, pH 7.0), stir at 45°C for 3h at a speed of 500r/min, and then put into a 4°C refrigerator for hydration for 12h to prepare casein (3%, w/v) stock solution. Add 0.5g bacterial powder to 20mL palm oil melted at 50°C, stir at a speed of 800r/min until evenly dispersed. Emulsify 20mL oil phase (palm oil containing bacterial powder) and 80mL mixed protein solution using a high shear homogenizer at 12000rpm for 4min.

1. Particle size and potential determination of Lactobacillus plantarum embedding emulsion

The droplet size was measured using a Malvern 3000 laser particle size analyzer at 25 °C; the ζ-potential of the droplets was characterized using a NANO ZS90 particle size and potential analyzer. Before measurement, the sample was diluted 1:100 in deionized water to avoid multiple scattering effects.

The results in Table 2 show that compared with casein (animal protein) or pea protein isolate (plant protein) alone, the emulsion prepared by compounding casein and pea protein isolate at a ratio of 2:1 has a smaller particle size and a larger absolute value of potential. A casein and pea protein isolate mass ratio of 2:1 was selected for subsequent experiments.

Table 2 Particle size and potential of Lactobacillus plantarum embedding emulsion

Note: Different letters indicate significant differences among the groups (P＜0.05).

Example 2

Mix casein (animal protein) and pea protein isolate (plant protein) and dissolve them in PBS (0.01M, pH 7.0), stir at 500 r/min at 45°C for 3 hours, and then put them in a 4°C refrigerator for hydration for 12 hours to prepare a mixed protein (6%, w/v) stock solution; dissolve gellan gum powder in deionized water, stir at 500 r/min at 45°C for 1 hour to prepare a gellan gum (0.4-2%, w/v, 0.4%, 0.8%, 1.2%, 1.6%, and 2% respectively) stock solution, and prepare a stock solution without gellan gum at the same time; stir 50 mL of the mixed protein solution and 50 mL of the gellan gum solution at 50°C at 800 r/min for 2 hours to prepare a mixed protein-gellan gum complex solution.

0.5 g of bacterial powder was added to 20 mL of palm oil melted at 50°C and stirred at 800 r/min until uniformly dispersed. 20 mL of oil phase (palm oil containing bacterial powder) and 80 mL of water phase (mixed protein-gellan gum complex solution) were emulsified using a high shear homogenizer at 12,000 rpm for 4 min.

1. Particle size and potential determination of Lactobacillus plantarum embedding emulsion

The droplet size was measured using a Malvern 3000 laser particle size analyzer at 25 °C; the ζ-potential of the droplets was characterized using a NANO ZS90 particle size and potential analyzer. Before measurement, the samples were diluted 1:100 in deionized water to avoid multiple scattering effects.

Table 3 shows the effect of gellan gum concentration on the particle size and ζ-potential of the emulsion. As the concentration of gellan gum increases, the particle size of the emulsion increases first and then decreases. When the concentration of gellan gum is higher than 0.8%, the particle size of the emulsion continues to increase. When the concentration of gellan gum is too low, it is not enough to stabilize the emulsion. Multiple oil droplets contact each other to form larger oil droplets, causing the emulsion particle size to increase. When the emulsifier (mixed protein-gellan gum complex) is excessive, it is adsorbed at the oil-water interface, causing the particle size to increase again. When the concentration of gellan gum is 0.8%, the particle size of the emulsion is the smallest.

The concentration of gellan gum has a significant effect on the ζ-potential of the emulsion. The larger the absolute value of the ζ-potential, the more stable the emulsion. Compared with the single protein emulsion, the absolute value of the ζ-potential of the emulsion with the mixed protein-gellan gum complex as an emulsifier increased significantly (P<0.05). The spatial repulsion between the emulsion particles prepared by the complex formed by the mixed protein and high concentration of gellan gum as an emulsifier increased, which improved the stability of the emulsion. When the concentration of gellan gum is higher than 0.8%, the absolute value of the emulsion potential decreases and the emulsion tends to be unstable.

Table 3 Particle size and potential of Lactobacillus plantarum embedding emulsion

Gellan gum concentration (%) Particle size (μm) Potential (mV) 0 13.86±0.16 ^f -22.54±0.31 ^f 0.2 19.62±0.23 ^b -24.92±0.12 ^e 0.4 23.2±0.26 ^a -26.53±0.27 ^d 0.6 18.75±0.19 ^c -27.18±0.23 ^c 0.8 12.89±0.25 ^e -30.86±0.13 ^a 1 16.5±0.17 ^d -28.25±0.25 ^b

Note: Different letters indicate significant differences among the groups (P＜0.05).

2. Physical stability of Lactobacillus plantarum embedded emulsion

The newly prepared emulsions (gellan gum concentrations of 0, 0.2%, 0.4%, 0.6%, 0.8% and 1%) were filled into 20 mL sealed glass bottles and stored at 4°C for 21 days.

After storage at 4°C for 21 days, the degree of stratification of the sample is closely related to the concentration of gellan gum. As shown in Figure 1, there is no significant difference in the degree of stratification of the emulsion when the concentration of gellan gum is 0.8% and 1%, but when the concentration of gellan gum is 1%, the emulsion color is yellowish and has more pores.

As shown in FIG2 , it is a graph showing the effect of gellan gum concentration (0, 0.2%, 0.4%, 0.6% and 0.8%) on the storage stability of the emulsion (4° C. and 25° C.).

3. Encapsulation rate of Lactobacillus plantarum encapsulation emulsion

20并涡旋振荡30分钟，然后用稀释涂布平板法测定植物杆菌的活力，即用无菌生理盐水连续稀释样品至适当浓度，将其涂布于MRS固体培养基上，37℃孵育48h。Add 1% w/v of

The mixture was vortexed at 20 for 30 minutes, and then the activity of Bacillus was determined by the dilution plate method, that is, the sample was continuously diluted with sterile saline to an appropriate concentration, spread on MRS solid culture medium, and incubated at 37°C for 48 hours.

Embedding rate (%) = biomass in sample / total biomass

As shown in Table 4, the embedding rate of the emulsion prepared with the mixed protein-gellan gum complex was significantly higher than that of the mixed protein alone (P<0.05). The results showed that the emulsion prepared with the protein-polysaccharide complex could significantly improve the embedding rate of Lactobacillus plantarum, and gradually increased with the increase of gellan gum concentration, but when the gellan gum was excessive, the embedding rate showed a decreasing trend. When the gellan gum concentration was 0.8%, the embedding rate of Lactobacillus plantarum in the emulsion was the highest (88.67%), and compared with the emulsion prepared with the mixed protein alone, the encapsulation efficiency was significantly improved by 20.32%, so the gellan gum concentration of 0.8% was selected for subsequent experiments.

Table 4 Encapsulation efficiency of Lactobacillus plantarum encapsulation emulsions with different gellan gum concentrations

Polysaccharide concentration (%) Embedding rate (%) 0 68.35±0.13 ^f 0.2 72.06±0.15 ^e 0.4 76.53±0.27 ^d 0.6 84.89±0.19 ^c 0.8 88.67±0.22 ^a 1.0 86.43±0.26 ^b

Note: Different letters indicate significant differences among the groups (P＜0.05).

4. Storage stability of Lactobacillus plantarum embedded emulsion

The Lactobacillus plantarum embedding emulsion was stored at 4°C for 21 days, and the surviving cells were counted on days 0, 7, 14, and 21, respectively.

As shown in Table 5, the initial viability of free plant lactobacillus, mixed protein emulsion and mixed protein-0.8% gellan gum emulsion was 9.44, 9.32 and 9.36 Lg CFU/mL, respectively. After 7 days, 14 days and 21 days, the surviving cells in the free group were significantly lower than those in the mixed protein and mixed protein-0.8% gellan gum emulsion (P<0.05). After 21 days of storage at 4°C, the number of surviving cells in the mixed protein-0.8% gellan gum emulsion (8.96±0.03 Lg CFU/mL) was significantly higher than that in the protein emulsion (8.73±0.03 Lg CFU/mL), with only a decrease of 0.4 Lg CFU/mL. These results show that the mixed protein emulsion or the mixed protein-0.8% gellan gum emulsion can significantly improve the storage stability of plant lactobacillus, among which the mixed protein-0.8% gellan gum emulsion has the best effect.

Table 5 Storage stability of Lactobacillus plantarum embedded emulsion

Note: Different letters indicate significant differences among the groups (P＜0.05).

5. Heat resistance of Lactobacillus plantarum embedding emulsion

The Lactobacillus plantarum embedded samples were heated at 63°C for 30 min and 72°C for 2 min to simulate pasteurization, and then immediately cooled in a room temperature water bath, and the number of viable cells was determined.

As shown in Table 6, after 30 minutes of treatment at 63°C, the survival rate of the free Lactobacillus plantarum sample was less than 2 Lg CFU/mL, and the mixed protein emulsion (4.58 Lg CFU/mL) and the mixed protein-0.8% gellan gum emulsion (6.47 Lg CFU/mL) significantly enhanced the activity of Lactobacillus plantarum after pasteurization (P<0.05). Compared with long-term sterilization (heating at 63°C for 30 minutes), heating at 75°C for 2 minutes had little effect on the activity of Lactobacillus plantarum. After heating at 75°C for 2 minutes, the activity of Lactobacillus plantarum in the mixed protein emulsion and the mixed protein-0.8% gellan gum emulsion decreased by 3.17 and 2.13 Lg CFU/mL, respectively. During the heat treatment process, the addition of gellan gum improved the protective effect of the emulsion on Lactobacillus plantarum, which may be due to the ability of gellan gum to resist thermal stress, and the protein and gellan gum formed a tight network structure as shown in Figure 3, which can better protect the internal bacteria. FIG3 is a cryo-SEM image of the Lactobacillus plantarum embedded emulsion. The microstructure of the mixed protein-0.8% gellan gum emulsion was recorded by a field emission scanning electron microscope (SU8010, Hitachi, Ltd., Japan). The emulsion droplets were placed in a cryo-SEM tube on a stand and frozen in nitrogen. The samples were transferred to a cryo-transfer system and sublimated at -100°C for 10 minutes. After platinum sputter coating, the coated samples were inserted into an observation chamber equipped with a cold module of the SEM platform and kept at -140°C for observation.

Results: Figures 3A and 3B are cryo-scan images of the mixed protein-0.8% gellan gum emulsion, which show that the shape is spherical and the particle size ranges from 10 to 20 μm. Figures 3C and 3D are cryo-scan images of the mixed protein-0.8% gellan gum emulsion, which show that the oil droplets are wrapped in a network structure, which may be due to the casein-gellan gum complex formed by electrostatic interaction between the mixed protein and gellan gum molecules, which can stabilize the palm oil interface and embed the oil droplets into a dense polymer network.

Table 6 Heat resistance of Lactobacillus plantarum embedding emulsion

6. Lactobacillus plantarum embedded emulsion simulates gastrointestinal digestion

The samples were incubated in simulated gastric fluid at 37°C for 2 h and then in simulated intestinal fluid for 4 h to evaluate the activity of Lactobacillus plantarum in the samples.

Table 7 lists the viability of free and encapsulated Lactobacillus plantarum during simulated gastrointestinal fluid digestion. During the 2 hours of culture in simulated gastrointestinal fluid, the survival rate of free and encapsulated Lactobacillus plantarum continued to decline due to the effects of hydrogen ions and pepsin. The activity of free Lactobacillus plantarum decreased from 9.44Lg CFU/mL to 4.29Lg CFU/mL, the activity of Lactobacillus plantarum in the mixed protein emulsion decreased from 9.32Lg CFU/mL to 6.14Lg CFU/mL, and the mixed protein-0.8% gellan gum emulsion decreased from 9.32Lg CFU/mL to 7.18Lg CFU/mL. The loss of viable cells in the mixed protein-0.8% gellan gum emulsion was significantly lower than that in the protein emulsion (P<0.05), which was mainly due to the protective effect of gellan gum in the emulsion system, which effectively reduced the hydrolysis of the protein layer and the rupture of the emulsion droplets.

When the sample was further digested in simulated intestinal fluid for 4 hours, the number of viable cells of free Lactobacillus plantarum was below the detection limit; for the mixed protein emulsion and the mixed protein-0.8% gellan gum emulsion, the activity of the encapsulated Lactobacillus plantarum only decreased slightly. The results showed that the tolerance of Lactobacillus plantarum encapsulated in the mixed protein-0.8% gellan gum emulsion to simulated intestinal fluid was higher than that of the mixed protein emulsion.

Table 7 Lactobacillus plantarum embedded emulsion simulated gastrointestinal digestion

Note: Different letters indicate significant differences among the groups (P＜0.05).

The application of the embedded Lactobacillus plantarum emulsion obtained in this embodiment in food. Food is used to regulate the intestinal flora of the host and protect the health of the gastrointestinal tract. Food includes yogurt, milk beverages, milk tablets, etc., which will not be described one by one here.

Example 3

2g of casein (animal protein) and 1g of pea protein isolate (plant protein) were mixed and dissolved in 100mL PBS (0.01M, pH 7.2), the concentration of casein powder was 20g/L, and the mixture was stirred at 400r/min for 2h at 40°C, and then placed in a 4°C refrigerator for hydration for 8h to prepare a mixed protein (3%, w/v) stock solution; gellan gum powder was dissolved in 100mL deionized water with a pH of 6.8, and stirred at 400r/min for 0.5h at 40°C to prepare a gellan gum 0.4% w/v stock solution, and 50mL of the mixed protein solution and 50mL of the gellan gum solution were stirred at 40°C at 700r/min for 3h to prepare a mixed protein-gellan gum complex solution.

0.5 g of bacterial powder was added to 10 mL of palm oil melted at 40°C and stirred at 300 r/min until uniformly dispersed. 10 mL of oil phase (palm oil containing bacterial powder) and 40 mL of water phase (mixed protein-gellan gum complex solution) were emulsified using a high shear homogenizer at 8000 rpm for 6 min.

Example 4

6 g of casein (animal protein) and 3 g of pea protein isolate (plant protein) were mixed and dissolved in 100 mL of PBS (0.01 M, pH 7.1), the concentration of casein powder was 60 g/L, and the mixture was stirred at 700 r/min at 60° C. for 5 h, and then placed in a 4° C. refrigerator for hydration for 16 h to prepare a mixed protein (9%, w/v) stock solution; gellan gum powder was dissolved in 100 mL of deionized water with a pH of 7.2, and stirred at 700 r/min at 50° C. for 3 h to prepare a gellan gum 2% w/v stock solution, and 50 mL of the mixed protein solution and 50 mL of the gellan gum solution were stirred at 60° C. at 900 r/min for 4 h to prepare a mixed protein-gellan gum complex solution.

0.5 g of bacterial powder was added to 5 mL of palm oil melted at 60°C and stirred at 500 r/min until uniformly dispersed. 5 mL of oil phase (palm oil containing bacterial powder) and 20 mL of water phase (mixed protein-gellan gum complex solution) were emulsified using a high shear homogenizer at 16,000 rpm for 2 min.

Example 5

The difference between this example and example 4 is that 1 g of bacterial powder is added to 5 mL of palm oil melted at 45°C and stirred at 400 r/min until uniformly dispersed. 5 mL of oil phase (palm oil containing bacterial powder) and 20 mL of water phase (mixed protein-gellan gum complex solution) are emulsified using a high shear homogenizer at 10,000 rpm for 3 min.

Example 6

The difference between this example and example 4 is that 1 g of bacterial powder is added to 2 mL of palm oil melted at 50°C and stirred at 600 r/min until uniformly dispersed. 2 mL of oil phase (palm oil containing bacterial powder) and 8 mL of water phase (mixed protein-gellan gum complex solution) are emulsified using a high shear homogenizer at 14000 rpm for 5 min.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (9)

1. The preparation method of the embedded lactobacillus plantarum emulsion is characterized by comprising the following steps of:

step one, the mass ratio is 2:1 and pea protein isolate powder, uniformly mixing and dispersing the mixture in 100mL PBS, stirring the mixture at the speed of 400-700r/min for 2-5h at the temperature of 40-60 ℃ at the concentration of 20-60g/L, and then placing the mixture into a refrigerator for hydration for 8-16h to obtain a mixed protein solution; the pH of PBS is 7.0-7.2;

dispersing 0.4-2g of gellan gum powder in 100mL of deionized water, and stirring at the speed of 400-700r/min for 0.5-3h at the temperature of 40-50 ℃ to obtain gellan gum solution;

step three, mixing the protein mixture solution with gellan gum solution according to a ratio of 1:1, and stirring at the speed of 700-900r/min for 2-4h at the temperature of 40-60 ℃ to obtain a mixed protein-gellan gum compound solution; in the mixed protein-gellan gum compound solution, the concentration of casein, pea protein isolate and gellan gum are respectively 20g/L,10g/L and 8g/L;

melting palm oil for later use, and mixing lactobacillus plantarum powder in the ratio of 1:40, 1:20 and 1: 10. 1: 5. or 1:2, adding the mixture into palm oil, and stirring at a speed of 300-800r/min until the mixture is uniformly dispersed to obtain an oil phase;

fifthly, mixing the oil phase with the mixed protein-gellan gum compound solution according to a proportion of 1:4, mixing the materials in a volume ratio to obtain a mixed solution;

step six, emulsifying the mixed solution for 2-6min at 8000-16000rpm to obtain mixed protein-gellan gum emulsion.

2. The preparation method according to claim 1, wherein lactobacillus plantarum (Lactobacillus plantarum) has a deposit number of cic 6002.

3. The method of claim 1, wherein the PBS is 0.01M and the refrigerator is at a temperature of 4 ℃.

4. The method of claim 1, wherein the deionized water has a pH of 6.8 to 7.2.

5. The method of claim 1, wherein the palm oil has a melting temperature of 40-60 ℃.

6. The lactobacillus plantarum-embedded emulsion obtained by the preparation method according to any one of claims 1 to 5.

7. Use of the embedded lactobacillus plantarum emulsion according to claim 6 in food products.

8. The use according to claim 6, wherein the food product is for regulating the intestinal flora of a host, protecting the health of the gastrointestinal tract.

9. A food product comprising the embedded lactobacillus plantarum emulsion of claim 6.

Images