Core-shell microcapsule containing high-activity plant lactobacillus as well as preparation method and application of core-shell microcapsule

Abstract

The invention discloses a core-shell microcapsule containing high-activity plant lactobacillus as well as a preparation method and application of the core-shell microcapsule, and belongs to the technical field of microcapsules. According to the preparation method, the plant lactobacillus KLDS 1.0328-EGCG microcapsule is prepared through an electrostatic spraying technology, WPC and beta-CD are used as packaging carriers, EGCG is added, lac is used as a shell layer, and the plant lactobacillus KLDS 1.0328-EGCG coaxial electrostatic spraying microcapsule with a core-shell structure is prepared. Simulated gastrointestinal digestion experiments prove that the coaxial electrostatic spraying capsule disclosed by the invention efficiently protects the biological activity of the probiotics. The invention provides a new thought for improving the biological activity of the probiotics, establishes a new method for improving the physiological characteristics and probiotic functions of the probiotics under environmental stress, has potential to play a probiotic role on human health through a synergistic effect in vivo, and provides a new thought for developing a novel probiotic protective agent.

Description

Technical Field

[0001] The invention relates to the technical field of microcapsules, in particular to a core-shell microcapsule containing highly active Lactobacillus plantarum and a preparation method and application thereof. Background Art

[0002] Probiotics are usually provided to consumers as fermentable or non-fermentable foods or dietary supplements. Studies have found that the functional properties of probiotics mainly include promoting the production of organic acids in the body, regulating the composition of intestinal flora, repairing epithelial tissue, enhancing immunity, inhibiting the adhesion of pathogens to the intestinal mucosa, lowering serum cholesterol and preventing gastrointestinal cancer. However, in food processing and the gastrointestinal tract, probiotics will encounter high temperature, low temperature, acidic conditions, oxidative conditions, osmotic pressure and water activity. These environmental pressures will have a significant impact on the biological functions of probiotics and limit the application of probiotics. Microencapsulation can be used as a probiotic encapsulation technology to embed probiotics into sealing materials, reduce cell loss during processing and storage, and effectively improve the survival rate, storage stability and bioavailability of probiotics in gastrointestinal digestion. Currently, the commonly used probiotic microencapsulation technologies include spray drying, emulsification, extrusion, complex coacervation, freeze drying, electrostatic spraying, etc.

[0003] Compared with other encapsulation methods, the microcapsules obtained by electrostatic spraying technology are smaller in size, which can be below 1μm, with a narrow size distribution, even close to monodisperse, and the charged droplets repel each other without agglomeration. The size and shape of the final product are relatively easy to control, and the activity of bioactive compounds can be effectively maintained without changing the chemical structure and physical properties. Thus, probiotics can be protected from extreme environments such as light, heat and oxygen. Electrostatic spraying technology is divided into uniaxial electrostatic spraying and coaxial electrostatic spraying. Coaxial electrostatic spraying uses a composite needle with two concentric needles to pump the encapsulated compound together with the biopolymer solution. Under the action of the electric field, the two solutions are ejected from the spinneret together, and solidify due to the evaporation of the solvent to form particles with a core-shell structure.

[0004] Prebiotics are substrates that are selectively utilized by human microorganisms and can improve the composition and / or activity of intestinal microorganisms, thereby benefiting human health. They are bioactive compounds. Existing literature reports that co-encapsulation of bioactive compounds and probiotics can improve biological activity and function, but for specific types of probiotics, it is still difficult to determine which bioactive compound to select for encapsulation has the best effect. Therefore, it is urgent to develop a microcapsule preparation method for Lactobacillus plantarum KLDS1.0328, select specific bioactive compounds for co-encapsulation, and protect the activity and function of probiotics to the greatest extent. Summary of the invention

[0005] The purpose of the present invention is to provide a core-shell microcapsule containing highly active Lactobacillus plantarum and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art. The coaxial electrostatic spray microcapsule preparation method provided by the present invention has both a high encapsulation rate and a strong ability to tolerate simulated gastrointestinal digestive fluid, and effectively protects the biological activity of probiotics.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a method for preparing Lactobacillus plantarum microcapsules, comprising the following steps:

[0008] Cultivating the Lactobacillus plantarum to obtain a bacterial suspension;

[0009] The β-cyclodextrin solution and the whey protein concentrate solution are mixed, Tween 80 and epigallocatechin gallate solution are added, and the mixture is mixed until the epigallocatechin gallate is completely dissolved, and the mixture is mixed with the bacterial suspension to obtain a nuclear layer solution;

[0010] Dissolve shellac in absolute ethanol to obtain a shell solution;

[0011] The core layer solution and the shell layer solution are respectively loaded with samples by using a coaxial electrostatic spray system, and electrostatic spraying is performed to obtain the Lactobacillus plantarum microcapsules.

[0012] Preferably, in the core layer solution, the mass fraction of epigallocatechin gallate in the epigallocatechin gallate solution is 0.06%-0.24%; the mass volume ratio of whey concentrate protein to water in the whey concentrate protein solution is 35g:100mL; the mass volume ratio of β-cyclodextrin to water in the β-cyclodextrin solution is 4g:100mL; and the mass ratio of the β-cyclodextrin solution to the whey concentrate protein solution is 4:1.

[0013] Preferably, the mass fraction of epigallocatechin gallate is 0.18%.

[0014] Preferably, the mass volume ratio of the shellac to the anhydrous ethanol is 1 g:10 mL.

[0015] Preferably, the plant lactobacillus is plant lactobacillus KLDS1.0328; the concentration of the plant lactobacillus in the bacterial suspension is 10 10 CFU / mL.

[0016] Preferably, in the coaxial electrostatic spray system, the core layer solution uses a stainless steel needle with a spinning needle inner diameter of 0.34 mm, and the shell layer uses a stainless steel needle with a spinning needle inner diameter of 1.01 mm;

[0017] The electrostatic spray spinning is carried out under the conditions of spinning voltage 17 kV, spinning distance 12 cm, shell solution injection flow rate 0.6 mL / h, core solution injection flow rate 0.4 mL / h, temperature 20° C., and humidity 30-40%.

[0018] The invention also provides a Lactobacillus plantarum microcapsule prepared according to the preparation method.

[0019] The present invention also provides a use of the Lactobacillus plantarum microcapsule in preparing a health food and / or a medicine for regulating intestinal flora.

[0020] The invention also provides a health food that helps to regulate intestinal flora, comprising the Lactobacillus plantarum microcapsules.

[0021] The present invention also provides a medicine for regulating intestinal flora, comprising the Lactobacillus plantarum microcapsule.

[0022] The present invention discloses the following technical effects:

[0023] The present invention prepares plant lactobacillus KLDS1.0328-EGCG microcapsules by electrostatic spraying technology, uses whey protein concentrate (WPC) and β-cyclodextrin (β-CD) as encapsulation carriers, adds epigallocatechin gallate (EGCG), and jointly constructs WPC / β-CD / Lp KLDS1.0328 / EGCG as a core layer, and uses shellac as a shell layer to prepare plant lactobacillus KLDS1.0328 / EGCG coaxial electrostatic spray microcapsules with a core-shell structure. Experiments have shown that the coaxial electrostatic spray capsules of the present invention efficiently protect the biological activity of probiotics. The present invention provides a new idea for improving the biological activity of probiotics, establishes a new idea and method for improving the physiological characteristics and probiotic functions of probiotics under environmental stress, which conforms to the concept of synbiotic preparations, has the potential to play a probiotic role in human health through synergistic effects in vivo, and provides a new idea for developing new probiotic protective agents and second-generation synbiotic preparations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Transmission electron microscopy (A) and fluorescence microscopy (B) images of coaxial electrospray ionization microcapsules. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0027] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0029] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0030] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0031] Whey protein concentrate (WPC) is a whey protein isolate and is currently the most commonly used protein encapsulation material. It plays an important role in protecting probiotics from drying, protecting the digestive tract, and extending storage time.

[0032] β-cyclodextrin is composed of 7 α-D-pyranose glucoses connected by α-(1-4) bonds, with a hydrophobic inner cavity and a hydrophilic outer surface, and is widely used to form inclusion complexes in the encapsulation process. β-cyclodextrin forms inclusion complexes using weak forces such as van der Waals forces, dipole-dipole interactions, and hydrogen bonds to clamp bioactive substances in its cavity.

[0033] Shellac is a natural polymer extracted from the resin excreted by insects and is recognized by the Food and Drug Administration as a safe food-grade material. Shellac is a low molecular weight resin, mainly composed of oxyacidic polyesters, and the oxyacids are divided into lipid acids and cyclic terpene acids connected by ester bonds, which constitute the hydrophobic and hydrophilic components of shellac respectively.

[0034] Epigallocatechin gallate (EGCG) is a typical flavan-3-ol phenolic compound and the catechin with the highest content among green polyphenols. Its polyhydroxy structure constitutes the structural basis of its physiological activity.

[0035] The Lactobacillus plantarum KLDS1.0328 used in the present invention has been disclosed in the paper "Ma Jiage, Jiang Zhanmei, Jiang Rui, et al. Physiological characteristics of Lactobacillus plantarum KLDS1.0328 under nutritional stress and storage stability analysis of its freeze-dried bacterial powder [J]. Food Science, 2021, 42(22): 155-161." published by the inventor team based on previous research. Lactobacillus plantarum was renamed Lactobacillus plantarum in 2022 with the release of the new international classification name; Lactobacillus plantarum is the new name for Lactobacillus plantarum. The applicant promises to distribute the above-mentioned biological materials to the public within 20 years from the date of application of the present invention.

[0036] The information of raw materials and reagents used in the present invention is shown in Table 1.

[0037] Table 1 Experimental materials and reagents

[0038]

[0039] Example 1 Preparation of Lactobacillus plantarum KLDS1.0328 uniaxial electrostatic spray capsules

[0040] 1. Cultivation of Lactobacillus plantarum KLDS1.0328

[0041] Fresh cultures were prepared by inoculating 2% (v / v) Lactobacillus plantarum KLDS1.0328 into MRS broth and cultured in an incubator at 37°C for two generations. The cultures were collected at the logarithmic growth phase, centrifuged at 8000×g for 15 min at 4°C, washed three times with sterile PBS buffer, and the concentration of the bacterial solution was adjusted to obtain a concentration of about 10 10 CFU / mL of bacterial cells.

[0042] 2. Preparation of Uniaxial Electrostatic Spray Solution

[0043] Dissolve whey protein concentrate (WPC) powder in sterile deionized water to prepare a 35% WPC solution (w / v). Weigh a certain amount of β-cyclodextrin and dissolve it in deionized water. Stir it at 500 rpm at 55 ° C for 2 h to prepare a 4% β-cyclodextrin solution (w / v). Mix the prepared WPC solution and β-cyclodextrin solution in a weight ratio of 8:2, and add the surfactant Tween 80 (5% w / w) to the mixed solution. Then add 0.12% (w / w) EGCG and mix and stir until EGCG is completely dissolved. Finally, resuspend the prepared bacterial suspension in the above solution.

[0044] 3. Electrostatic spray device and process

[0045] The electrostatic spray device of the present invention is composed of four parts: a high-voltage power supply, a propulsion pump, a syringe and a receiver (aluminum foil). The electrospray solution is inserted into a 10 mL syringe, equipped with an 18G steel needle, an electrode is clamped on the metal needle, and the aluminum foil is covered on a collection plate, and the electrospray microcapsules are collected on the aluminum foil.

[0046] Electrospray process: flow rate (0.4 mL / h), voltage of 17 kV and receiving distance of 12 cm, relative humidity controlled at 30% to 40%, spinning temperature of 20°C.

[0047] Example 2 Preparation of coaxial electrostatic spray microcapsules of Lactobacillus plantarum KLDS1.0328

[0048] 1. Cultivation of Lactobacillus plantarum KLDS1.0328

[0049] Fresh cultures were prepared by inoculating 2% (v / v) Lactobacillus plantarum KLDS1.0328 into MRS broth and cultured in an incubator at 37°C for two generations. The cultures were collected at the logarithmic growth phase, centrifuged at 8000×g for 15 min at 4°C, washed three times with sterile PBS buffer, and the concentration of the bacterial solution was adjusted to obtain a concentration of about 10 10 CFU / mL of bacterial cells.

[0050] 2. Preparation of Coaxial Electrostatic Spray Solution

[0051] Preparation of nuclear layer solution: Dissolve whey protein concentrate (WPC) powder in sterile deionized water to prepare 35% WPC solution (w / v). Weigh a certain amount of β-cyclodextrin and dissolve it in deionized water. Stir it at 500rpm at 55°C for 2h to prepare a 4% β-cyclodextrin solution (w / v). Mix the prepared WPC solution and β-cyclodextrin solution in a weight ratio of 8:2, and add the surfactant Tween 80 (5% w / w) to the mixed solution. Then add different concentrations (0%, 0.06%, 0.12%, 0.18%, 0.24%, w / w) of EGCG to the above electrospray solution and mix and stir until EGCG is completely dissolved. Finally, resuspend the prepared bacterial suspension in the above solution.

[0052] Preparation of shell solution: 10% (w / v) shellac was dissolved in anhydrous ethanol to obtain a shell solution.

[0053] 3. Electrostatic spray device and process

[0054] Coaxial electrostatic spraying was performed using a homemade electrostatic spraying system. WPC / β-CD / Lp KLDS1.0328 / EGCG and shellac solutions were loaded into 10 mL syringes, respectively, and then placed on a propulsion pump.

[0055] The core layer used a stainless steel needle (23G) with an inner diameter of 0.34 mm, and the shell layer used a stainless steel needle (17G) with an inner diameter of 1.01 mm. Electrostatic spraying was carried out under the conditions of spinning voltage 17 kV, spinning distance 12 cm, shell layer injection flow rate 0.6 mL / h, core layer injection flow rate 0.4 mL / h, spinning temperature 20°C, and humidity 30-40%.

[0056] Example 3 Microscopic observation of electrospray ionization microcapsules

[0057] The internal structure of the coaxial electrospray ionization microcapsules was observed using a H-800 transmission electron microscope (Hitachi, Japan).

[0058] The distribution of Lactobacillus plantarum KLDS1.0328 in the coaxial electrospray ionization microcapsules was observed using an inverted fluorescence microscope. The specific method is as follows:

[0059] Rhodamine 123 fluorescent dye was dissolved in dimethyl sulfoxide to prepare 1mmol / L of Rhodamine 123 fluorescent staining solution. When used, it was diluted to 5μg / mL with sterile PBS solution, added to the suspension of Lactobacillus plantarum KLDS1.0328, mixed evenly and incubated at room temperature in the dark for 30min. Then centrifuged at 8000×g for 10min, and the above steps were repeated three times with PBS buffer solution. The bacterial precipitate was collected and added to the above coaxial electrostatic spray solution. A glass slide was pasted on tin foil, electrostatic spraying was performed, and the distribution of the stained Lactobacillus plantarum KLDS1.0328 in the coaxial electrostatic spray microcapsules was observed using a fluorescence microscope.

[0060] Figure 1 TEM image of the internal structure of shellac-WPC / β-CD / Lp KLDS1.0328 / EGCG after coaxial electrostatic spraying and the distribution of Lactobacillus plantarum KLDS1.0328 encapsulated in coaxial electrospray microcapsules under fluorescence microscope.

[0061] Depend on Figure 1 In Figure A, it can be observed that the microcapsules have an obvious core-shell structure. The color of the shell layer is relatively light, the color of the core layer is darker, and there is a clear boundary between the core layer and the shell layer. The shell layer has a lower grayscale, which may be due to the density of the core hydrophilic composite material being greater than that of the shell shellac. Figure 1 In the middle B, bright green fluorescence was observed in the coaxial electrospray microcapsules, further indicating that Lactobacillus plantarum KLDS1.0328 was encapsulated in the microcapsules. Coaxial electrospray can better encapsulate Lactobacillus plantarum KLDS1.0328 in the microcapsules, because the shell layer of shellac is added on the basis of the original uniaxial microcapsules. Even if Lactobacillus plantarum KLDS1.0328 is distributed on the surface of the core layer WPC / β-CD / Lp KLDS1.0328 / EGCG microcapsules, it can be encapsulated inside by the shell layer shellac.

[0062] Example 4 Effect verification experiment of electrospray microcapsules

[0063] 1. Experimental Methods

[0064] 1.1 Determination of viable count of Lactobacillus plantarum KLDS1.0328

[0065] The number of viable bacteria was detected according to the gradient dilution and pouring method in the national standard GB 4789.2-2016. The Lactobacillus plantarum KLDS 1.0328 was fully mixed with the carrier solution, and the number of viable bacteria of Lactobacillus plantarum KLDS1.0328 was determined before the encapsulation process. After obtaining the probiotic microcapsules, 10 mg of microcapsule sample was taken, added to the PBS buffer solution, and homogenized in a magnetic stirrer for 10 minutes. Then, the PBS buffer solution was used for continuous dilution, and the appropriate dilution was selected and poured into a plate, and the number of viable bacteria was detected after incubation at 37°C for 48 hours in an incubator. The survival rate was calculated as follows:

[0066]

[0067] Where: N represents the number of viable bacteria in the microcapsule after encapsulation (lg CFU / g), N o Represents the number of viable bacteria in the solution before packaging (lg CFU / g).

[0068] 1.2 In vitro digestion simulation

[0069] The tolerance of Lactobacillus plantarum KLDS1.0328 with different encapsulation methods and without encapsulation in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was tested.

[0070] Take 0.08 mL of 0.5 mol / L magnesium chloride hexahydrate solution, 2.5 mL of 1 mol / L sodium bicarbonate solution, 1.38 mL of 0.5 mol / L potassium chloride solution, 0.18 mL of 0.5 mol / L potassium dihydrogen phosphate solution, and 2.36 mL of 2 mol / L sodium chloride solution in a 100 mL volumetric flask, add distilled water to make the volume to 100 mL, adjust the pH to pH = 3.0, add 1 g of pepsin, filter and sterilize with a 0.45 μm water filter membrane to prepare simulated gastric fluid.

[0071] Weigh 0.068 g of potassium dihydrogen phosphate and dissolve it in 10 mL of water. Use 1 mol / L sodium hydroxide solution to adjust the pH of the solution to 6.8. Then add 0.1 g of trypsin and filter with a 0.45 μm water filter to sterilize and prepare a simulated intestinal digestive fluid.

[0072] Weigh 100 mg of electrospray capsules, place in 4.5 mL of sterile SGF, and digest in a shaking incubator (100 rpm) at 37°C for 2 h. Centrifuge at 8000×g for 15 min at 4°C, remove the supernatant, resuspend in 10 mL of sterile SIF, and shake and digest in a shaking incubator at 37°C for 2 h. Determine the number of viable bacteria of Lactobacillus plantarum KLDS1.0328 in SGF and electrospray microcapsules after SIF by the gradient dilution and pour plate method described in "1.1 Determination of the number of viable bacteria of Lactobacillus plantarum KLDS1.0328". Use free Lactobacillus plantarum KLDS1.0328 under the same conditions as a control.

[0073] 1.3 Data Analysis

[0074] The experiment was repeated three times, and the results were expressed as mean ± standard deviation. SPSS26.0 software was used for one-way analysis of variance, and Duncan test was used to compare the differences between variables. P < 0.05 indicated that there was a significant difference between different samples. Statistical graphs were drawn using Origin 2021.

[0075] 2. Experimental results

[0076] 2.1 Experimental results of viable count of Lactobacillus plantarum KLDS1.0328

[0077] Table 2 shows the changes in the number of live bacteria before and after encapsulating Lactobacillus plantarum KLDS1.0328 using different electrostatic spray microcapsules.

[0078] After coaxial electrostatic spray encapsulation, the number of viable bacteria of Lactobacillus plantarum KLDS1.0328 co-encapsulated with different concentrations of EGCG decreased to varying degrees (P < 0.05). This was due to the rapid evaporation of water and the change in osmotic pressure during the coaxial electrospray process, which led to a decrease in the number of viable bacteria. However, compared with the coaxial electrostatic spray microcapsules of shellac-WPC / β-CD / Lp KLDS1.0328, the encapsulation efficiency of Lactobacillus plantarum KLDS1.0328 in the coaxial electrostatic spray microcapsules with EGCG was significantly increased (P < 0.05). The encapsulation efficiency of the coaxial electrostatic spray microcapsules of shellac-WPC / β-CD / Lp KLDS1.0328 / 0.18% EGCG was significantly higher than that of other coaxial electrostatic spray microcapsules (P < 0.05), which was (95.05 ± 0.71)%. It can be concluded that an appropriate amount of EGCG can significantly increase the number of viable bacteria of Lactobacillus plantarum KLDS1.0328.

[0079] Table 2 Statistics of viable bacteria count and encapsulation rate of each sample before and after encapsulation

[0080]

[0081] Note: Different lowercase letters in the same column represent significant differences (P<0.05)

[0082] 2.2 Results of in vitro digestion simulation experiment

[0083] Table 3 shows the changes in the number of viable probiotic bacteria after simulated gastrointestinal digestion of free Lactobacillus plantarum KLDS1.0328, WPC-β-CD / Lp KLDS1.0328 / EGCG microcapsules prepared by uniaxial electrostatic spraying, and shellac-WPC / β-CD / Lp KLDS1.0328 / EGCG microcapsules prepared by coaxial electrostatic spraying. After passing through gastric juice and intestinal juice, the number of viable bacteria of Lactobacillus plantarum KLDS 1.0328 decreased to varying degrees. Compared with free Lactobacillus plantarum KLDS1.0328 and Lactobacillus plantarum KLDS1.0328 encapsulated by uniaxial electrostatic spraying technology, the number of viable bacteria of Lactobacillus plantarum KLDS 1.0328 encapsulated by coaxial electrostatic spraying was significantly increased after simulated gastrointestinal digestion (P<0.05). This indicates that the coaxial electrospray microcapsules with core-shell structure greatly increase the tolerance of Lactobacillus plantarum KLDS1.0328 to gastric juice and small intestinal juice.

[0084] Table 3 The number of viable cells of Lactobacillus plantarum KLDS1.0328 encapsulated or not encapsulated in microcapsules after treatment with simulated intestinal fluid

[0085]

[0086] Note: Different lowercase letters in the superscripts of the data in the same column represent significant differences among different samples (P<0.05); different uppercase letters in the superscripts of the data in the same row represent significant differences among different treatments of the same sample (P<0.05).

[0087] It can be seen from the results of Table 2 and Table 3 that, compared with the single-axis electrostatic spray microcapsules prepared with 0.12% EGCG solution in Example 1, in Example 2, the encapsulation rate of the microcapsules prepared by coaxial electrostatic spraying with shellac as the shell solution is reduced to a certain extent, but the present invention further narrows the gap in the encapsulation rate between the two by optimizing and adjusting the concentration of the EGCG solution; and the simulated gastrointestinal digestion experiment shows that the digestion resistance of the coaxial electrostatic spray microcapsules is significantly improved compared with the single-axis electrostatic spray microcapsules. In short, the plant lactobacillus microcapsules provided by the present invention have both a high encapsulation rate and a strong ability to tolerate gastrointestinal digestion, efficiently protect the biological activity of probiotics, and can effectively deliver live plant lactobacillus bacteria to the intestine.

[0088] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing Lactobacillus plantarum microcapsules, characterized in that: The following steps are involved: Cultivating the Lactobacillus plantarum to obtain a bacterial suspension; The β-cyclodextrin solution and the whey protein concentrate solution are mixed, Tween 80 and epigallocatechin gallate solution are added, and the mixture is mixed until the epigallocatechin gallate is completely dissolved, and the mixture is mixed with the bacterial suspension to obtain a nuclear layer solution; Dissolve shellac in absolute ethanol to obtain a shell solution; The core layer solution and the shell layer solution are respectively loaded with samples by using a coaxial electrostatic spray system, and electrostatic spraying is performed to obtain the Lactobacillus plantarum microcapsules.

2. The preparation method according to claim 1, characterized in that In the nuclear layer solution, the mass fraction of epigallocatechin gallate in the epigallocatechin gallate solution is 0.06%-0.24%; the mass volume ratio of whey concentrated protein to water in the whey concentrated protein solution is 35g:100mL; the mass volume ratio of β-cyclodextrin to water in the β-cyclodextrin solution is 4g:100mL; the mass ratio of the β-cyclodextrin solution to the whey concentrated protein solution is 4:

1.

3. The preparation method according to claim 2, characterized in that: The mass fraction of epigallocatechin gallate is 0.18%.

4. The preparation method according to claim 1, characterized in that: The mass volume ratio of the shellac to the anhydrous ethanol is 1 g:10 mL.

5. The preparation method according to claim 1, characterized in that: The plant lactobacillus is plant lactobacillus KLDS1.0328; the concentration of the plant lactobacillus in the bacterial suspension is 10 10 CFU / mL.

6. The preparation method according to claim 1, characterized in that: In the coaxial electrostatic spray system, the core layer solution uses a stainless steel needle with an inner diameter of 0.34 mm, and the shell layer uses a stainless steel needle with an inner diameter of 1.01 mm; The electrostatic spray spinning is carried out under the conditions of spinning voltage 17 kV, spinning distance 12 cm, shell solution injection flow rate 0.6 mL / h, core solution injection flow rate 0.4 mL / h, temperature 20° C., and humidity 30-40%.

7. A Lactobacillus plantarum microcapsule prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the Lactobacillus plantarum microcapsules as claimed in claim 7 in the preparation of health foods and / or medicines for regulating intestinal flora.

9. A health food that helps regulate intestinal flora, characterized in that: The invention comprises the Lactobacillus plantarum microcapsules according to claim 7.

10. A drug for regulating intestinal flora, characterized in that: The invention comprises the Lactobacillus plantarum microcapsules according to claim 7.

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