Probiotic microcapsule as well as preparation method and application thereof

Abstract

The invention relates to the technical field of microbial preparations, and particularly discloses a probiotic microcapsule as well as a preparation method and application thereof. The probiotic microcapsule comprises a four-layer structure, the first layer is core material particles composed of probiotics and prebiotics, the second layer is a polysaccharide copolymer, the third layer is cationic polysaccharide, and the fourth layer is an oily substance. The mass ratio of the probiotics to the prebiotics to the polysaccharide copolymer to the cationic polysaccharide to the oily substance is (16-20): (64-80): (8-12): (13-15): 16. The survival rate of probiotics in the probiotic microcapsule prepared by the invention can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of microbial products, and more specifically, to a probiotic microcapsule, a preparation method thereof, and an application thereof. Background Art

[0002] According to the definition of FAO / WHO (2009), probiotics refer to live microorganisms that confer health benefits on the host when ingested in adequate amounts; when ingested in appropriate amounts, probiotics exert probiotic effects by regulating the intestinal flora and the metabolites of the flora; in addition to directly acting on the intestinal flora, probiotics can also exert probiotic effects by indirectly regulating the metabolites of the intestinal flora, such as short-chain fatty acids, bile acids, lipids, and neurotransmitters, etc., thereby improving the health of the body. For probiotics to exert their probiotic effects, they must maintain activity and metabolic stability in both the product and the host. Generally, it is required that the viable count in each gram or each milliliter of the product is not less than 1×10 6 CFU. However, during the production, transportation, sales, storage, etc. of probiotic products, the activity of probiotics is extremely susceptible to the influence of pH, temperature, oxygen, and the host digestive system (the pH value of the human stomach is approximately 1.8 - 3.0), and the viable count will drop significantly, resulting in the viable count finally colonized in the intestine being lower than the theoretical value.

[0003] The microcapsule embedding technology is a technology that can provide effective protection for probiotics, and can form a physical barrier between the bacterial cells and the external environment, thereby delaying the damage of the adverse environment to the bacterial cells. Currently, the common microcapsule embedding technologies mainly include the extrusion method, the emulsion cross-linking method, and the fluidized bed coating method.

[0004] In the extrusion method, the probiotics to be embedded are added to a pre-prepared colloidal solution, and then dropped into a curing solution (commonly acetate buffer solution and calcium chloride solution) in the form of droplets through a syringe needle or nozzle to form tiny particles. The most commonly used wall materials for this method include whey protein, sodium alginate, chitosan, xanthan gum, gelatin, carrageenan, pectin, cellulose acetate phthalate, and paraffin oil, etc. The advantages of this method are easy operation, simple equipment, low cost, mild process, and high embedding rate; the disadvantages are that the uniformity of the microcapsule particles is relatively poor, and the slow formation rate of the microspheres also restricts its large-scale production.

[0005] The emulsion cross-linking method involves mixing probiotics with a wall material solution, then further mixing a small amount of the mixture with a large amount of vegetable oil, homogenizing to form a W / O emulsion. A hardening agent is added to the oil phase, and the water-soluble polymer forms tiny insoluble colloidal bead particles in the oil phase due to cross-linking. Finally, microcapsules are collected using centrifugation or membrane filtration techniques. The most commonly used wall materials for this method include soy protein, inulin, etc. The advantages of this method are a mild process, simple equipment, easy operation, relatively high survival rate of the bacteria, and relatively small particle size of the microencapsulation, making it suitable for large-scale production. The disadvantages are that it is difficult to solve the non-recovery and loss of vegetable oil, and the increase in oil usage greatly raises the cost.

[0006] In the fluidized bed coating method, probiotic powder particles are suspended in an upward-flowing hot air stream and come into contact with the atomized coating solution to be coated. As the surface of the probiotics is encapsulated and becomes heavier, it descends. When approaching the hotter hot air outlet at the lower layer, the moisture of the particles quickly evaporates, and the mass becomes lighter and rises, coming into contact with the coating solution again. This cycle repeats until the microencapsulation is complete. However, in this method of encapsulating probiotics, there are situations where the fluidized bed has a small spray flow rate and needs to be dried after encapsulation. During the long-term heating process of the probiotics, the survival rate will be affected.

[0007] Currently, in the existing technologies, there are solutions to improve the effect of maintaining the viability of bacteria by studying the embedding layer materials, but the overall effect still needs to be improved. For example, in Chinese Patent CN115363217A, using bacterial powder, WPI powder, GA powder, and shortening, probiotics are encapsulated in the bacterial liquid, and probiotic microcapsule powder is prepared by freeze-drying. Without spray drying, the maximum initial survival rate of probiotics is 54.96%, and there is a large loss of the initial viable bacteria count. Therefore, it is necessary to further study the encapsulation method of probiotics. Summary of the Invention

[0008] One of the objectives of the present invention is to provide a microcapsule capable of improving the survival rate of probiotics in the microcapsule and its preparation method.

[0009] To achieve this objective, the technical solution of the present invention is as follows:

[0010] A probiotic microcapsule includes a four-layer structure. The first layer is a core material particle composed of probiotics and prebiotics, the second layer is a polysaccharide copolymer, the third layer is a cationic polysaccharide, and the fourth layer is an oily substance;

[0011] The mass ratio of the probiotics, prebiotics, polysaccharide copolymer, cationic polysaccharide, and oily substance is (16 - 20):(64 - 80):(8 - 12):(13 - 15):16.

[0012] The probiotic microcapsules obtained by sequentially encapsulating specific encapsulation layers in the present invention can ensure that the probiotics have stronger vitality and still have an ideal viable count after long-term storage, which is beneficial to improving the product effect.

[0013] In the probiotic microcapsules of the present invention, the prebiotic is one or more of isomaltooligosaccharide, fructooligosaccharide, galactooligosaccharide, polydextrose, inulin;

[0014] The polysaccharide copolymer is one or more of pullulan, sodium alginate, carrageenan;

[0015] The cationic polysaccharide is chitosan;

[0016] The oily substance is one or more of palm oil, soybean oil, cocoa butter, shortening;

[0017] The probiotics can be any probiotics approved for use in the art. For example, it includes one or more of Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus mucosae, Lactobacillus rhamnosus, Bifidobacterium animalis subsp. lactis, Bifidobacterium animalis subsp. animalis, Bifidobacterium longum subsp. longum, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis, Lactiplantibacillus plantarum, Limosilactobacillus fermentum.

[0018] Preferably, the probiotics of the present invention are freeze-dried powders.

[0019] The combination of the raw materials in the present invention can provide good protection for the encapsulated probiotics and improve the viable count rate during long-term storage.

[0020] The present invention also provides a method for preparing the above probiotic microcapsules, which includes:

[0021] (1) Mixing the probiotics and prebiotics with water to form core material particles;

[0022] (2) Coating the polysaccharide copolymer outside the core material particles to form double-layer particles;

[0023] (3) Coating the cationic polysaccharide outside the double-layer particles to form triple-layer particles;

[0024] (4) Coating the oily substance outside the triple-layer particles to form probiotic microcapsules.

[0025] The present invention has explored and studied the encapsulation method and found that when encapsulating probiotics and prebiotics, directly coating with a polysaccharide copolymer is not conducive to forming an effective particle morphology. Therefore, a method of first mixing the probiotics and prebiotics with water to prepare core material particles and then coating is adopted, thereby ensuring the obtaining of a high encapsulation rate.

[0026] In the preparation method of the probiotic microcapsules of the present invention, the core material particles, double-layer particles and triple-layer particles are prepared by a top-spray fluidized bed, and the encapsulation of the oily substance is completed by a bottom-spray fluidized bed.

[0027] In the present invention, after mixing probiotics (bacterial powder) and prebiotics, water is first used as a binder, and granulation is achieved by a top-spray fluidized bed; then, through the top-spray fluidized bed, the second-layer embedding is carried out after the aqueous solution of the polysaccharide copolymer is atomized at the top opening of the top-spray fluidized bed; again through the top-spray fluidized bed, the third-layer embedding is carried out after the aqueous solution of the cationic polysaccharide is atomized at the top opening of the top-spray fluidized bed; finally, through the bottom-spray fluidized bed, the oily substance is sprayed up by the bottom-spray fluidized bed to achieve the fourth-layer embedding, and probiotic microcapsules are obtained.

[0028] For the selection of substances in each layer in the present invention, a specific preparation and encapsulation method is adopted. If other combination methods of the material layer substances are used (such as changing the selection or encapsulation order of the material substances in each layer), or the spraying position of the liquid materials in each layer (top spray / bottom spray) is changed, the preparation method of the fluidized bed of the present invention cannot be effectively applied to achieve the preparation of large-scale and low-cost embedded microcapsules.

[0029] In step (1) of the preparation method of the probiotic microcapsules of the present invention, by top-spraying water, the mixture of water, probiotics and prebiotics is contacted in a top-spray fluidized bed to complete granulation, and the core material particles are obtained after drying;

[0030] Among them, the mass ratio of the total mass of the probiotics and prebiotics to the amount of water used is (80 - 100):(7 - 8); preferably 80:7.

[0031] And / or, in step (1), the inlet air temperature of the top-spray fluidized bed is 30 - 50°C, the flow rate of the mixture of probiotics and prebiotics in the top-spray fluidized bed is 120 - 130 radians per second, and the spraying rate of water is 1 - 3 g / min.

[0032] In step (2) of the preparation method of the probiotic microcapsules of the present invention, the core material particles are encapsulated in a top-spray fluidized bed by top-spraying an aqueous solution of a polysaccharide copolymer, and the double-layer particles are obtained after drying;

[0033] Among them, the concentration of the aqueous solution of the polysaccharide copolymer is 2 - 6%, preferably 2 - 5%;

[0034] And / or, in step (2), the inlet air temperature of the top-spray fluidized bed is 30 - 50°C, the flow rate of the core material particles in the top-spray fluidized bed is 120 - 130 radians per second, and the spraying rate of the aqueous solution of the polysaccharide copolymer is 1 - 3 g / min.

[0035] In step (3) of the preparation method of the probiotic microcapsules of the present invention, by top-spraying an aqueous solution of a cationic polysaccharide, the encapsulation of the double-layer particles is achieved in a top-spray fluidized bed, and the triple-layer particles are obtained after drying;

[0036] Among them, the concentration of the aqueous solution of the cationic polysaccharide is 1-2%, preferably 1.5-1.8%;

[0037] And / or, in step (3), the inlet air temperature of the top-spray fluidized bed is 30-50°C, the flow rate of the double-layer particles in the top-spray fluidized bed is 120-130 radians / second, and the spraying rate of the aqueous solution of the cationic polysaccharide is 3-5 g / min.

[0038] In step (4) of the preparation method of the probiotic microcapsules of the present invention, by bottom-spraying the oily substance, the encapsulation of the triple-layer particles is achieved in a bottom-spray fluidized bed; among them, the temperature of the oily substance is 30-60°C, preferably 55-58°C;

[0039] And / or, in step (4), the inlet air temperature of the bottom-spray fluidized bed is 30-50°C, the flow rate of the triple-layer particles in the bottom-spray fluidized bed is 185-190 radians / second, and the spraying rate of the oily substance is 20-25 g / min.

[0040] The parameter settings in each preparation step of the present invention can ensure the effective preparation of the embedded microcapsules, with a high embedding rate and good protection effect.

[0041] Those skilled in the art can select appropriate equipment parameters according to the settings of the mixing state parameters of the solid material and the liquid material (solid particle flow rate, liquid spraying rate) and common knowledge in the art and the fluidized bed equipment used. Preferably, in the preparation method of the probiotic microcapsules of the present invention, the air extraction frequency of the top-spray fluidized bed is 20-50 Hz, the rotation speed of the peristaltic pump for liquid spraying is 1-5 rpm / min, and the spray gun pressure is 0.1-1 Mpa;

[0042] And / or, the air extraction frequency of the bottom-spray fluidized bed is 20-50 Hz, the rotation speed of the peristaltic pump for liquid spraying is 5-20 rpm / min, and the spray gun pressure is 0.1-0.3 Mpa.

[0043] Further preferably, in the preparation method of the probiotic microcapsules of the present invention, the air extraction frequency of the top-spray fluidized bed is 20 Hz, the rotation speed of the peristaltic pump for liquid spraying is 1.2-1.5 rpm / min, and the spray gun pressure is 0.2 Mpa;

[0044] And / or, the air extraction frequency of the bottom-spray fluidized bed is 30 Hz, the rotation speed of the peristaltic pump for liquid spraying is 10 rpm / min, and the spray gun pressure is 0.2 Mpa.

[0045] The present invention also provides an application of the above-mentioned probiotic microcapsules or a preparation method of probiotic microcapsules in enhancing the survival rate of probiotics in probiotic microcapsules.

[0046] The beneficial effects of the present invention are at least as follows:

[0047] The present invention provides a microcapsule preparation method that can significantly improve the survival rate of probiotics in probiotic microcapsules. The obtained probiotic microcapsules have a high embedding rate and can ensure stronger vitality of probiotics after long-term storage. Specific Embodiments

[0048] The preferred embodiments of the present invention will be described in detail below in conjunction with the embodiments. It should be understood that the following embodiments are given only for the purpose of illustration and are not used to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0049] Unless otherwise specified, the experimental methods used in the following embodiments are all conventional methods. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels or prepared by conventional methods in the art unless otherwise specified.

[0050] The probiotic PC-01 used in the specific embodiments of the present invention, with the full name of Lactobacillus paracasei strain PC-01, is disclosed in Chinese Patent CN110257297B, and the viable count is 1×10 11 cfu / g.

[0051] Example 1 Preparation of Probiotic Microcapsules

[0052] This example provides a probiotic microcapsule and its preparation method, and the specific steps are as follows:

[0053] Raw materials: Probiotic PC-01, isomaltooligosaccharide, 4% pullulan polysaccharide solution, 1.5% chitosan solution, palm oil at 56°C.

[0054] Equipment: Top-spray fluidized bed, bottom-spray fluidized bed, sieve (40 - 80 mesh).

[0055] Preparation method:

[0056] Core material preparation: Mix probiotic PC-01 and isomaltooligosaccharide evenly and then add them into the top-spray fluidized bed to make them suspended in the upward-flowing hot air stream. The air intake frequency of the top-spray fluidized bed is 20 Hz, the air inlet temperature is 40°C, and the moving speed of the mixed powder of probiotic PC-01 and isomaltooligosaccharide in the top-spray fluidized bed is 125 radians / second.

[0057] The water is atomized and added into the top-spray fluidized bed in a top-spray manner, contacting with the mixed powder of probiotic PC-01 and isomaltooligosaccharide. The total mass ratio of probiotic PC-01 and isomaltooligosaccharide to the mass of water is 80:7. After mixing and granulating, it is dried for another 5 minutes to obtain the core particles. The rotation speed of the top-spray peristaltic pump is 1.5 rpm / min, and the spray gun pressure is 0.2 Mpa, so that the speed of water entering the top-spray fluidized bed is 2 g / min.

[0058] Second-layer coating: The core particles are added into the top-spray fluidized bed to make them suspended in the upward-flowing hot air stream. The air extraction frequency of the top-spray fluidized bed is 20 Hz and the inlet air temperature is 40 °C, so that the moving speed of the core particles in the top-spray fluidized bed is 125 radians per second.

[0059] The pullulan polysaccharide solution is atomized and added into the top-spray fluidized bed in a top-spray manner. After mixing with the core particles, it is dried for another 5 minutes to obtain the double-layer particles after coating. The rotation speed of the top-spray peristaltic pump is 1.5 rpm / min, and the spray gun pressure is 0.2 Mpa, so that the speed of the pullulan polysaccharide solution entering the top-spray fluidized bed is 2.7 g / min.

[0060] Third-layer coating: The double-layer particles are added into the top-spray fluidized bed to make them suspended in the upward-flowing hot air stream. The air extraction frequency of the top-spray fluidized bed is 20 Hz and the inlet air temperature is 40 °C, so that the moving speed of the double-layer particles in the top-spray fluidized bed is 125 radians per second.

[0061] The chitosan solution is atomized and added into the top-spray fluidized bed in a top-spray manner. After mixing with the double-layer particles, it is dried for another 5 minutes to obtain the triple-layer particles after re-coating. The rotation speed of the top-spray peristaltic pump is 1.2 rpm / min, and the spray gun pressure is 0.2 Mpa, so that the speed of the chitosan solution entering the top-spray fluidized bed is 4.3 g / min. After the triple-layer particle granulation is completed, it is first sieved with an 80-mesh sieve, and the upper large particles are discarded. Then it is sieved with a 40-mesh sieve, and the lower small particles are discarded.

[0062] Fourth-layer coating: The sieved triple-layer particles are added into the bottom-spray fluidized bed to make them suspended in the upward-flowing hot air stream. The air extraction frequency of the bottom-spray fluidized bed is 30 Hz and the inlet air temperature is 40 °C, so that the moving speed of the triple-layer particles in the bottom-spray fluidized bed is 188 radians per second.

[0063] The palm oil is atomized and added into the bottom-spray fluidized bed in a bottom-spray manner. After mixing with the triple-layer particles, it is dried for another 5 minutes to obtain the quadruple-layer particles after re-coating. The rotation speed of the bottom-spray peristaltic pump is 10 rpm / min, and the spray gun pressure is 0.2 Mpa, so that the speed of the palm oil entering the bottom-spray fluidized bed is 23 g / min.

[0064] Finally, in each particle, the mass ratio of probiotics, isomaltooligosaccharide, pullulan, chitosan, and palm oil is 16:64:11.5:14:16.

[0065] The encapsulation rate of probiotics in the four-layer microcapsules and the survival rate of probiotics under low-temperature storage at 4 °C were detected (the detection results are shown in Table 1). The blank control was the unencapsulated probiotics PC-01.

[0066] Table 1 Encapsulation rate and survival rate of probiotics in microcapsules

[0067] Group Entrapment efficiency (%) 1-month survival rate (%) 6-month survival rate (%) 1-year survival rate (%) Blank control 42 23 3 Microcapsule 75.3 87.7 73 25

[0068] Preparation of probiotic microcapsules in Example 2

[0069] This example provides a probiotic microcapsule and its preparation method. The specific steps are as follows:

[0070] On the basis of Example 1, isomaltooligosaccharide was replaced with fructooligosaccharide, the chitosan concentration was adjusted to 1.8%, the quality of the core particles was improved, and the remaining raw materials and preparation methods were the same as those in Example 1. In the finally obtained probiotic-fructooligosaccharide-pullulan-chitosan-palm oil microcapsules, the mass ratio of probiotics, fructooligosaccharide, pullulan, chitosan, and palm oil is 20:80:11.5:15:16.

[0071] The encapsulation rate of probiotics in the four-layer microcapsules and the survival rate of probiotics under low-temperature storage at 4 °C were detected (the detection results are shown in Table 2). The blank control was the same as that in Example 1.

[0072] Table 2 Encapsulation rate and survival rate of probiotics in microcapsules

[0073] Group Entrapment efficiency (%) 1-month survival rate (%) 6-month survival rate (%) 1-year survival rate (%) Blank control 42 23 3 Microcapsule 76.2 89.6 72.5 26.6

[0074] Preparation of probiotic microcapsules in Example 3

[0075] This example provides a probiotic microcapsule and its preparation method. The specific steps are as follows:

[0076] On the basis of Example 1, pullulan was replaced with sodium alginate, the concentration was adjusted to 5%, the addition amount of probiotics PC-01 was increased to change the mass ratio of probiotics and prebiotics, and the remaining raw materials and preparation methods were the same as those in Example 1. In the finally obtained probiotic-isomaltooligosaccharide-sodium alginate-chitosan-palm oil microcapsules, the mass ratio of probiotics, isomaltooligosaccharide, sodium alginate, chitosan, and palm oil is 20:64:8:14:16.

[0077] The encapsulation rate of probiotics in the four-layer microcapsules and the survival rate of probiotics under low-temperature storage at 4 °C were detected (the detection results are shown in Table 3). The blank control was the same as that in Example 1.

[0078] Table 3 Encapsulation rate and survival rate of probiotics in microcapsules

[0079] Group Entrapment efficiency (%) 1-month survival rate (%) 6-month survival rate (%) 1-year survival rate (%) Blank control 42 23 3 Microcapsule 80.3 88.3 74.2 26.7

[0080] Preparation of probiotic microcapsules in Example 4

[0081] This example provides a probiotic microcapsule and its preparation method, and the specific steps are as follows:

[0082] On the basis of Example 1, replace palm oil with soybean oil, adjust the temperature to 55 °C, increase the addition amount of probiotic PC-01 to change the mass ratio of probiotics and prebiotics, and the other raw materials and preparation methods are the same as those in Example 1. Finally, in the probiotic-isomaltooligosaccharide-pullulan-chitosan-soybean oil microcapsule, the mass ratio of probiotics, isomaltooligosaccharide, pullulan, chitosan, and soybean oil is 20:64:11.5:14:16.

[0083] Detect the encapsulation rate of probiotics in the four-layer microcapsule and the survival rate of probiotics under low-temperature storage at 4 °C (the test results are shown in Table 4). The blank control is the same as that in Example 1.

[0084] Table 4 Encapsulation rate and survival rate of probiotics in microcapsules

[0085] Group Entrapment efficiency (%) 1-month survival rate (%) 6-month survival rate (%) 1-year survival rate (%) Blank control 42 23 3 Microcapsule 79.4 86.6 73.5 24.6

[0086] Preparation of probiotic microcapsules in Example 5

[0087] This example provides two kinds of probiotic microcapsules and their preparation methods, and the specific steps are as follows:

[0088] On the basis of Example 1, replace probiotic PC-01 with Lactobacillus paracasei LC-37 (commercially available, viable cell count 5.0×10 10 cfu / g) and F-DVS L.casei 01 (commercially available, 2.0×10 10 cfu / g) respectively.

[0089] Detect the encapsulation rate of probiotics in the four-layer microcapsule after preparation and the survival rate of probiotics under low-temperature storage at 4 °C (the test results are shown in Table 5).

[0090] Table 5 Encapsulation rate and survival rate of probiotics in microcapsules

[0091] Group Entrapment efficiency (%) 1-month survival rate (%) 6-month survival rate (%) 1-year survival rate (%) LC-37 Blank control 50 22 5 LC-37 Microcapsule 76 79.2 65.3 21.9 LC-01 Blank control 51 26 2 LC-01 Microcapsule 78 81.7 63.3 22.6

[0092] Preparation of probiotic microcapsules in Example 6

[0093] This example provides a probiotic microcapsule and its preparation method, and the specific steps are as follows:

[0094] On the basis of Example 1, pullulan was replaced with carrageenan, the concentration was adjusted to 2%, the chitosan concentration was adjusted to 1%, and the addition amount of probiotic PC-01 was increased to change the mass ratio of probiotic to prebiotic. The remaining raw materials and preparation method were the same as those in Example 1. Finally, in the probiotic-isomaltooligosaccharide-carrageenan-chitosan-palm oil microcapsule, the mass ratio of probiotic, isomaltooligosaccharide, carrageenan, chitosan, and palm oil was 20:64:8.5:13:16.

[0095] The entrapment rate of probiotic in the four-layer microcapsule and the survival rate of probiotic under low-temperature storage at 4 °C were detected (the detection results are shown in Table 6). The blank control was the same as that in Example 1.

[0096] Table 6 Entrapment rate and survival rate of probiotic in microcapsule

[0097] Group Entrapment efficiency (%) 1-month survival rate (%) 6-month survival rate (%) 1-year survival rate (%) Blank control 42 23 3 Microcapsule 77.6 81.2 63.2 25.7

[0098] Preparation of probiotic microcapsule in Example 7

[0099] This example provides two kinds of probiotic microcapsules and their preparation methods. The specific steps are as follows:

[0100] On the basis of Example 1, palm oil was replaced with shortening and cocoa butter respectively, the temperature was adjusted to 55 °C, and the addition amount of probiotic PC-01 was increased to change the mass ratio of probiotic to prebiotic. The remaining raw materials and preparation method were the same as those in Example 1. Finally, in the probiotic-isomaltooligosaccharide-pullulan-chitosan-shortening / cocoa butter microcapsule, the mass ratio of probiotic, isomaltooligosaccharide, pullulan, chitosan, and shortening / cocoa butter was 20:64:11.5:14:16.

[0101] The entrapment rate of probiotic in the four-layer microcapsule and the survival rate of probiotic under low-temperature storage at 4 °C were detected (the detection results are shown in Table 7). The blank control was the same as that in Example 1.

[0102] Table 7 Entrapment rate and survival rate of probiotic in microcapsule

[0103]

[0104] Comparative Example 1

[0105] This comparative example provides a probiotic microcapsule and its preparation method. The specific steps are as follows:

[0106] On the basis of Example 1, in order not to add extra moisture, the step of preparing the core material by mixing the probiotic PC-01 and isomaltooligosaccharide mixed powder with water first in Example 1 was omitted, and a 4% pullulan polysaccharide solution was directly used, and the probiotic PC-01 and isomaltooligosaccharide mixed powder were embedded by the same method as the two-layer coating step in Example 1.

[0107] Finally, it was found that the probiotic PC-01 and isomaltooligosaccharide mixed powder agglomerated into large chunks and could not form a uniform particle morphology.

[0108] Comparative Example 2

[0109] This comparative example provides a probiotic microcapsule and a preparation method thereof, and the specific steps are as follows:

[0110] Raw materials: 50 g of probiotic PC-01, 450 g of isomaltooligosaccharide, 5 g of beeswax and 95 g of coconut oil.

[0111] Preparation method:

[0112] After mixing the probiotic PC-01 and isomaltooligosaccharide evenly, add them into a top-spray fluidized bed to make them suspended in an upward-flowing hot air stream, and the moving speed in the top-spray fluidized bed is 125 radians / second.

[0113] Heat and melt the coconut oil and beeswax, mix them evenly and use them as the embedding liquid. Add this embedding liquid into the bottom-spray fluidized bed at a speed of 23 g / min by the bottom-spray method to mix with the mixture of probiotic PC-01 and isomaltooligosaccharide.

[0114] Finally, it was found that particles could not be effectively formed.

[0115] Comparative Example 3

[0116] This comparative example provides a probiotic microcapsule and a preparation method thereof, and the specific steps are as follows:

[0117] Raw materials: 50 g of probiotic PC-01, 450 g of resistant dextrin, 4 g of corn starch and 96 g of water.

[0118] Preparation method:

[0119] After mixing the probiotic PC-01 and resistant dextrin evenly, add them into a bottom-spray fluidized bed to make them suspended in an upward-flowing hot air stream, and the moving speed in the bottom-spray fluidized bed is 125 radians / second.

[0120] Mix the corn starch with boiling water and continuously stir magnetically as the embedding liquid. Add this embedding liquid into the bottom-spray fluidized bed at a speed of 5 g / min by the bottom-spray method to mix with the mixture of probiotic PC-01 and resistant dextrin. After spraying the embedding liquid, continue to dry for 10 min and then check the material state.

[0121] It was found that the embedding material liquid could not be sprayed up. The equipment was stopped, and when the equipment was opened, it was found that large chunks had formed below, and it was impossible to effectively form embedding particles.

[0122] Comparative Example 4

[0123] This comparative example provides a probiotic microcapsule and a preparation method thereof. The specific steps are as follows:

[0124] Raw materials: 100 g of probiotic PC-01, 400 g of isomaltooligosaccharide, 4 g of starch, and 96 g of water.

[0125] Preparation method:

[0126] The probiotic PC-01 and isomaltooligosaccharide were mixed evenly and then added to a bottom-spray fluidized bed, making it suspended in an upward-flowing hot air stream. The moving speed in the bottom-spray fluidized bed was 125 radians per second.

[0127] The starch was mixed with boiling water and continuously magnetically stirred to serve as the embedding material liquid. This embedding material liquid was added to the bottom-spray fluidized bed at a speed of 5 g / min by bottom-spraying to be mixed with the mixture of probiotic PC-01 and isomaltooligosaccharide.

[0128] It was found that large chunks had formed and it was impossible to effectively form embedding particles.

[0129] Comparative Example 5

[0130] This comparative example provides a probiotic microcapsule and a preparation method thereof. The specific steps are as follows:

[0131] On the basis of Example 1, only the way of the fourth-layer coating was changed to:

[0132] The sieved three-layer particles were added to a top-spray fluidized bed, making it suspended in an upward-flowing hot air stream. The moving speed of the three-layer particles in the top-spray fluidized bed was 125 radians per second.

[0133] The palm oil was atomized and added to the top-spray fluidized bed by top-spraying to be mixed with the three-layer particles. The speed at which the palm oil entered the top-spray fluidized bed was 23 g / min.

[0134] Finally, it was found that the three-layer particles and the palm oil were unevenly embedded in the fluidized bed and aggregated at the top-spray position, resulting in stratification to form large lumps and unable to achieve effective embedding.

[0135] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made thereto based on the present invention, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection of the present invention.

Claims

1. A probiotic microcapsule, comprising a four-layer structure, characterized in that, The first layer is a core material particle composed of probiotics and prebiotics, the second layer is a polysaccharide copolymer, the third layer is a cationic polysaccharide, and the fourth layer is an oily substance; The mass ratio of the probiotics, prebiotics, polysaccharide copolymer, cationic polysaccharide and oily substance is (16 - 20):(64 - 80):(8 - 12):(13 - 15):

16.

2. The probiotic microcapsule according to claim 1, wherein The prebiotics are one or more of isomaltooligosaccharide, fructooligosaccharide, galactooligosaccharide, polydextrose, inulin; The polysaccharide copolymer is one or more of pullulan, sodium alginate, carrageenan; The cationic polysaccharide is chitosan; The oily substance is one or more of palm oil, soybean oil, cocoa butter, shortening; The probiotics include one or more of Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium animalis subsp. lactis, Bifidobacterium animalis subsp. animalis, Bifidobacterium longum subsp. longum, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis, Lactiplantibacillus plantarum, Limosilactobacillus fermentum.

3. The preparation method of the probiotic microcapsule according to claim 1 or 2, characterized in that, It includes: (1) Mix the probiotics and prebiotics with water to form core material particles; (2) Coating the polysaccharide copolymer outside the core material particles to form double-layer particles; (3) Coating the cationic polysaccharide outside the double-layer particles to form three-layer particles; (4) Coating the oily substance outside the three-layer particles to form probiotic microcapsules.

4. The preparation method of the probiotic microcapsule according to claim 3, wherein, The core material particles, double-layer particles and three-layer particles are prepared by a top-spray fluidized bed, and the coating of the oily substance is completed by a bottom-spray fluidized bed.

5. The preparation method of the probiotic microcapsule according to claim 4, wherein In step (1), by spraying water from the top, the mixture of water and probiotics and prebiotics is contacted in the top-spray fluidized bed to complete granulation, and the core material particles are obtained after drying; Among them, the ratio of the total mass of the probiotics and prebiotics to the amount of water used is (80 - 100):(7 - 8); And / or, in step (1), the inlet air temperature of the top-spray fluidized bed is 30 - 50 °C, the flow rate of the mixture of probiotics and prebiotics in the top-spray fluidized bed is 120 - 130 radians per second, and the spraying rate of water is 1 - 3 g / min.

6. The preparation method of the probiotic microcapsule according to claim 4, characterized in that, In step (2), by spraying an aqueous solution of the polysaccharide copolymer from the top, the coating of the core material particles is realized in the top-spray fluidized bed, and the double-layer particles are obtained after drying; Among them, the concentration of the aqueous solution of the polysaccharide copolymer is 2 - 6%, preferably 2 - 5%; And / or, in step (2), the inlet air temperature of the top-spray fluidized bed is 30 - 50 °C, the flow rate of the core material particles in the top-spray fluidized bed is 120 - 130 radians per second, and the spraying rate of the aqueous solution of the polysaccharide copolymer is 1 - 3 g / min.

7. The preparation method of the probiotic microcapsule according to claim 4, wherein In step (3), by spraying an aqueous solution of the cationic polysaccharide from the top, the coating of the double-layer particles is realized in the top-spray fluidized bed, and the three-layer particles are obtained after drying; Among them, the concentration of the aqueous solution of the cationic polysaccharide is 1 - 2%, preferably 1.5 - 1.8%; And / or, in step (3), the inlet air temperature of the top-spray fluidized bed is 30-50°C, the flow rate of the double-layer particles in the top-spray fluidized bed is 120-130 radians per second, and the spraying rate of the aqueous solution of the cationic polysaccharide is 3-5 g / min.

8. The preparation method of the probiotic microcapsule according to claim 4, wherein, In step (4), the three-layer particles are encapsulated in the bottom-spray fluidized bed by bottom-spraying the oily substance; wherein, the temperature of the oily substance is 30-60°C, preferably 55-58°C; And / or, in step (4), the inlet air temperature of the bottom-spray fluidized bed is 30-50°C, the flow rate of the three-layer particles in the bottom-spray fluidized bed is 185-190 radians per second, and the spraying rate of the oily substance is 20-25 g / min.

9. The preparation method of the probiotic microcapsule according to claim 4, characterized in that, The air extraction frequency of the top-spray fluidized bed is 20-50 Hz, the rotational speed of the peristaltic pump for liquid spraying is 1-5 rpm / min, and the spray gun pressure is 0.1-1 Mpa; And / or, the air extraction frequency of the bottom-spray fluidized bed is 20-50 Hz, the rotational speed of the peristaltic pump for liquid spraying is 5-20 rpm / min, and the spray gun pressure is 0.1-0.3 Mpa.

10. Use of the probiotic microcapsule according to claim 1 or 2 or the preparation method of the probiotic microcapsule according to any one of claims 3-9 in enhancing the survival rate of probiotics in the probiotic microcapsule.

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