Probiotics adopting composite gel system and preparation method thereof

Abstract

The invention relates to the technical field of probiotics, in particular to probiotics adopting a composite gel system and a preparation method of the probiotics, and the probiotics comprise the following components in percentage by mass: 2-6% of an HMPC solution, 8-20% of fructo-oligosaccharide, 5-15% of inulin, 0.2-1.5% of an ionic cross-linking agent, 0.5-1% of silicon dioxide and the balance of probiotic freeze-dried powder. According to the invention, HPMC (hydroxypropyl methyl cellulose), fructo-oligosaccharide, inulin and an ionic cross-linking agent are cooperatively constructed, and HPMC is compounded with fructo-oligosaccharide and inulin, so that a molecular network with different hydrogen bond densities and hydrophilicity can be formed, and a three-dimensional matrix structure of a cellulose-based skeleton, oligosaccharide branched chains and calcium ion cross-linking points is constructed; the compactness and the stability of a gel system in gastric acid are remarkably improved through the dual effects of intramolecular hydrogen bonds and Ca < 2 + > ion bridges in the ionic cross-linking agent.

Description

Technical Field

[0001] This invention relates to the field of probiotics technology, specifically to a probiotic using a composite gel system and its preparation method. Background Technology

[0002] Probiotics, as live microorganisms, can provide definite health benefits to the host when ingested in sufficient quantities. Their efficacy depends on a sufficient number of live bacteria being able to safely reach the intestines, colonize, and multiply, traversing the harsh environment of the upper digestive tract. However, most probiotic products currently face two key technical bottlenecks in practical applications: First, the stomach acid barrier results in extremely low survival rates of live bacteria: The human stomach is a highly acidic environment, with a pH as low as 1.5 on an empty stomach, and even after eating, the pH is usually only around 3.0. Most probiotic strains, such as common lactobacilli and bifidobacteria, are extremely sensitive to acidic environments and will be largely inactivated under such low pH conditions. Studies have shown that the survival rate of unprotected probiotics after exposure to gastric juices is generally less than 10%, or even lower, seriously affecting the efficacy and reliability of the product.

[0003] Second, the release site in the intestine is unstable, resulting in poor colonization efficiency: Some probiotics survive through the stomach, and their release behavior after entering the intestine is random and uncontrollable. They may be released prematurely at non-optimal sites of action, such as the duodenum or jejunum, failing to be effectively transported to the main sites of action, such as the colon. This randomness of release leads to a decrease in the colonization efficiency of probiotics, preventing them from forming a dominant flora in the target area, thus restricting the stable performance of their physiological functions. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a probiotic using a composite gel system and its preparation method, thereby improving the efficacy and reliability of probiotic products.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a probiotic using a composite gel system, comprising by mass 2-6% HMPC solution, 8-20% fructooligosaccharides, 5-15% inulin, 0.2-1.5% ionic crosslinking agent, 0.5-1% silica, and the balance being lyophilized probiotic powder.

[0006] Furthermore, the HPMC concentration in the HPMC solution is 2%, and the viscosity range at 20°C is 100-4000 mPa·s.

[0007] Furthermore, the fructooligosaccharide has a DE value of 20-40 and an average degree of polymerization of 4-6.

[0008] Furthermore, the inulin has a molecular weight of 3-5 kDa and a moisture content of ≤5%.

[0009] Furthermore, the ionic crosslinking agent is a 0.05-0.5 mol / L CaCl2 solution.

[0010] A method for preparing probiotics using a composite gel system, comprising the following steps: Preparation of S1 and HMPC solutions HPMC was dispersed in deionized water at 80-90℃, stirred evenly, and cooled to room temperature to form a transparent viscous solution, thus preparing a 2% HMPC solution. The solution was then allowed to stand for 1 hour to remove bubbles. S2, blending HPMC, fructooligosaccharides and inulin were mixed in the specified mass ratio and stirred and dispersed at room temperature for 20 minutes to form a homogeneous solution. S3, calcium ion crosslinking Add CaCl2 solution dropwise to the homogeneous solution after blending, so that Ca... 2+ The concentration of the solution was 10-50 mol / L, and the mixture was stirred continuously for 30 min. The pH was then adjusted to 6.5-7.0 to obtain the precursor of the composite gel system. S4. Drying and pulverizing The precursor of the composite gel system was frozen at -20℃ for 6 hours, and then vacuum dried at -50℃ for 24 hours in a freeze dryer. The freeze-dried product was pulverized and collected to obtain the composite gel system. S5, Hybrid The composite gel system obtained in S4 is mixed evenly with probiotic freeze-dried powder to obtain probiotics using the composite gel system.

[0011] Furthermore, prior to step S1, the HPMC is dried at 40-45°C for 2 hours to eliminate the moisture absorption effect of the HPMC.

[0012] Furthermore, before step S2, inulin and fructooligosaccharides are mixed evenly and then dried in a vacuum dryer for 20 minutes.

[0013] Furthermore, in step S4, the freeze-dried product is pulverized to a fineness of 100-200 mesh, sieved, and then collected.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention utilizes HPMC (hydroxypropyl methylcellulose), fructooligosaccharides, inulin, and an ionic crosslinking agent for synergistic construction. HPMC, combined with fructooligosaccharides and inulin, forms molecular networks with different hydrogen bond densities and hydrophilicity, constructing a three-dimensional matrix structure of "cellulose-based backbone + oligosaccharide branch chains + calcium ion crosslinking points." Through intramolecular hydrogen bonds and the calcium ions in the ionic crosslinking agent... 2+The dual effect of ion bridging significantly improves the density and stability of the gel system in gastric acid; 2. This invention utilizes a composite gel system composed of HPMC (hydroxypropyl methylcellulose), fructooligosaccharides, inulin, and an ionic crosslinking agent. Under acidic conditions, hydroxyl groups are protonated, sugar chains coil, and Ca... 2+ - Enhanced sugar complexation leads to the formation of closed structures; Under neutral and weakly alkaline conditions, the hydroxyl groups dissociate, the HPMC chain segments extend, and Ca... 2+ Partial detachment from the complex and opening of the network pores form a reversible swelling / contraction dynamic response system, which can control the release location and rate of probiotics, thereby improving the efficacy and reliability of probiotic products. 3. The composite gel system of this invention not only exhibits physical entanglement of HPMC molecular chains, but also through Ca... 2+ Ion-induced formation of sugar carboxyl complexes; the double cross-linked structure endows the composite gel system with excellent mechanical stability and anti-swelling properties. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1: This invention discloses a probiotic using a composite gel system, comprising by weight 2% HMPC solution, 8% fructooligosaccharides, 5% inulin, 0.2% ionic crosslinking agent (0.05 mol / L CaCl2 solution), 0.5% silica, and the balance being lyophilized probiotic powder.

[0017] It should be noted that the concentration of HPMC in the HPMC solution is 2%, and the viscosity range at 20°C is 100-4000 mPa·s.

[0018] It should be noted that the DE value of the oligofructose is 20-40, and the average degree of polymerization is 4-6.

[0019] It should be noted that the molecular weight of the inulin is 3-5 kDa and the moisture content is ≤5%.

[0020] A method for preparing probiotics using a composite gel system, comprising the following steps: Preparation of S1 and HMPC solutions HPMC was dried at 40-45℃ for 2 hours to eliminate the hygroscopic effect of HPMC. HPMC was then dispersed in deionized water at 80-90℃. After stirring evenly and cooling to room temperature, a transparent viscous solution was formed, and a 2% HMPC solution was prepared. The solution was then allowed to stand for 1 hour to remove bubbles. S2, blending First, mix inulin and fructooligosaccharides evenly and then dry them in a vacuum desiccator for 20 minutes. Then, mix HPMC, fructooligosaccharides and inulin according to the mass ratio and stir and disperse at room temperature for 20 minutes to form a homogeneous solution. S3, calcium ion crosslinking Add CaCl2 solution dropwise to the homogeneous solution after blending, so that Ca... 2+ The concentration of the solution was 10-50 mol / L, and the mixture was stirred continuously for 30 min. The pH was then adjusted to 6.5-7.0 to obtain the precursor of the composite gel system. S4. Drying and pulverizing The precursor of the composite gel system was frozen at -20℃ for 6 hours, and then vacuum dried at -50℃ for 24 hours in a freeze dryer. The freeze-dried product was pulverized to a fineness of 100-200 mesh, and collected after sieving to obtain the composite gel system. S5, Hybrid The composite gel system obtained in S4 is mixed evenly with probiotic freeze-dried powder to obtain probiotics using the composite gel system.

[0021] Example 2: The difference between this embodiment and Embodiment 1 is that the probiotic using a composite gel system comprises, by mass, 4% HMPC solution, 14% fructooligosaccharides, 10% inulin, 0.8% ionic crosslinking agent (0.3 mol / L CaCl2 solution), 0.8% silica, and the remainder is lyophilized probiotic powder.

[0022] Example 3: The difference between this embodiment and Embodiment 1 is that the probiotic using a composite gel system comprises, by mass, 6% HMPC solution, 20% fructooligosaccharides, 15% inulin, 1.5% ionic crosslinking agent (0.5 mol / L CaCl2 solution), 1% silica, and the remainder is lyophilized probiotic powder.

[0023] Comparative Example 1: The difference between this comparative example and Example 2 is that no gel encapsulation system is used; only the same mass of probiotic lyophilized powder as in Example 2 is used, and HPMC, fructooligosaccharides, inulin, CaCl2, or other protective excipients are not added. This comparative example is used to simulate the survival of commercially available ordinary lyophilized probiotics after exposure to gastric acid in an unprotected state, and to directly compare the protective effect with that of the composite gel system of the present invention.

[0024] Comparative Example 2: The difference between this comparative example and Example 2 is that a single encapsulation system containing only HPMC is used instead of a composite gel system, without the addition of fructooligosaccharides, inulin, and CaCl2 ion crosslinking agents. Specifically, the HPMC solution is mixed evenly with an equal amount of lyophilized probiotic powder, followed by direct lyophilization and pulverization, but without forming a three-dimensional composite gel network. This system relies solely on the physical encapsulation effect of HPMC and lacks oligosaccharide chain structures and CaCl2 ion crosslinking agents. 2+ The cross-linking points prevent the construction of stable acid-stable gel structures, thus serving as a control for single HPMC embedding.

[0025] Experimental verification and data: 1. A simulated pH response experiment was conducted on the composite gel systems prepared in Examples 1-3, and the results are shown in the table below:

[0026] As shown in the table above, the composite gel system prepared using the method described in this application can achieve stable gelation at pH 2.0. This is because, under strongly acidic conditions, the H+ in the solution... + At high concentrations, the equilibrium between the solvation layer and the polymer surface changes. High H + The activity decreases the effect of certain solvated ions (such as phosphate and carbonate) on Ca. 2+ The tendency of complexation makes free Ca 2+ The concentration is relatively high; Ca 2+ It can simultaneously form weak coordination or bridging with oxygen atoms from both HPMC (hydroxyl) and inulin / FOS (hydroxyl), although the hydroxyl group has a strong affinity for Ca. 2+ While the complexing ability of the group is not as strong as that of the carboxyl group, under conditions of high ionic strength and high local concentration, the cumulative effect of this multi-point weak coordination is sufficient to form a stable "ion bridge" network.

[0027] Multiple polymer chains pass through the same Ca 2+ or similar Ca 2+ The aggregates are "bridged" and "bound", forming localized high-density cross-linked regions; Strong acid environments also promote hydrogen bond rearrangement between polymer chains (HPMC–HPMC, HPMC–FOS, HPMC–Inulin), increase chain entanglement, and limit the overall swelling of the system, which manifests as gel volume shrinkage or densification. After the formation of dense cross-links, partial desolvation occurs locally in the gel (water is bound or expelled), resulting in smaller network pores and a denser texture, which effectively prevents gastric acid and proteases from eroding the encapsulated probiotics.

[0028] In summary, Ca in an acidic environment 2+The bridging, hydrogen bonding between polymer chains, and entanglement together improve the crosslinking density and mechanical strength of the gel, forming an acid-stable barrier.

[0029] It rapidly swells and releases in simulated intestinal fluid (pH 6.8), hydroxyl groups dissociate, HPMC segments unfold, and Ca... 2+ Partial detachment from the complex opens the network pores, forming a dynamic response system of "reversible swelling / contraction" to precisely control the release location and rate of probiotics.

[0030] 2. Animal experiments were conducted on the probiotics prepared in Examples 1-3 and Comparative Examples 1-3. The results are shown in the table below:

[0031] As shown in the table above, the probiotics prepared using the composite gel system of this application exhibit significantly higher gastric survival rate and intestinal viable bacteria rate in animal experiments compared to comparative examples 1 and 2, which did not use the composite gel system. The principle behind this is: This application, by compounding HPMC with fructooligosaccharides and inulin, can form molecular networks with different hydrogen bond densities and hydrophilicities, constructing a three-dimensional matrix structure of "cellulose-based backbone + oligosaccharide branched chains + calcium ion crosslinking points"; through intramolecular hydrogen bonds and Ca in the ionic crosslinking agent... 2+ The dual effect of ion bridging significantly improves the density and stability of the gel system in gastric acid. Therefore, under the action of gastric acid at pH 2.0, an ion barrier layer is formed on the gel surface, which can inhibit H+ ions. + Diffusion; and in the gut at pH 6.8, it can rapidly expand and release probiotics; Furthermore, fructooligosaccharides and inulin can be utilized by target bacteria in the gut; providing energy substrates and promoting colonization and proliferation; achieving a dual probiotic effect of "protection + promotion"; and regulating calcium... 2+ Concentration, sugar ratio, and HPMC viscosity grade can be customized to produce different release curves; it has the potential to be expanded into a variety of intestinal-targeted release products.

[0032] In addition, this application uses a freeze-drying process to process the precursor of the composite gel system. The freeze-drying process can retain the interconnected pores inside the composite gel, thereby improving the adsorption stability and redispersibility of probiotics during the mixing process, resulting in good flowability of the prepared probiotic powder.

[0033] This system represents a leap from traditional "physical encapsulation protection" to "intelligent responsive protection," enabling probiotics to maintain a high survival rate in a highly acidic environment and achieve precise release in the gut.

[0034] Compared with existing technologies that encapsulate single HPMC, sodium alginate, or monosaccharides, this system is not only multi-layered in structure and dual-responsive in function (pH + ions), but also has a synergistic effect on nutrition. It is an innovative system that combines functionality and foodability.

[0035] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A probiotic using a composite gel system, characterized in that, The product comprises, by weight, 2-6% HMPC solution, 8-20% fructooligosaccharides, 5-15% inulin, 0.2-1.5% ionic crosslinking agent, 0.5-1% silica, and the balance being lyophilized probiotic powder.

2. The probiotic using a composite gel system according to claim 1, characterized in that, The HPMC concentration in the HPMC solution is 2%, and the viscosity range at 20°C is 100-4000 mPa·s.

3. The probiotic using a composite gel system according to claim 1, characterized in that, The fructooligosaccharide has a DE value of 20-40 and an average degree of polymerization of 4-6.

4. The probiotic using a composite gel system according to claim 1, characterized in that, The inulin has a molecular weight of 3-5 kDa and a moisture content of ≤5%.

5. The probiotic using a composite gel system according to claim 1, characterized in that, The ionic crosslinking agent is a 0.05-0.5 mol / L CaCl2 solution.

6. A method for preparing probiotics using a composite gel system, characterized in that, The preparation of probiotics using a composite gel system according to any one of claims 1-5 comprises the following steps: Preparation of S1 and HMPC solutions HPMC was dispersed in deionized water at 80-90℃, stirred evenly, and cooled to room temperature to form a transparent viscous solution, thus preparing a 2% HMPC solution. The solution was then allowed to stand for 1 hour to remove bubbles. S2, blending HPMC, fructooligosaccharides and inulin were mixed in the specified mass ratio and stirred and dispersed at room temperature for 20 minutes to form a homogeneous solution. S3, calcium ion crosslinking Add CaCl2 solution dropwise to the homogeneous solution after blending, so that Ca... 2+ The concentration of the solution was 10-50 mol / L, and the mixture was stirred continuously for 30 min. The pH was then adjusted to 6.5-7.0 to obtain the precursor of the composite gel system. S4. Drying and pulverizing The precursor of the composite gel system was frozen at -20℃ for 6 hours, and then vacuum dried at -50℃ for 24 hours in a freeze dryer. The freeze-dried product was pulverized and collected to obtain the composite gel system. S5, Hybrid The composite gel system obtained in S4 is mixed evenly with probiotic freeze-dried powder to obtain probiotics using the composite gel system.

7. The method for preparing probiotics using a composite gel system according to claim 6, characterized in that, Before step S1, HPMC is dried at 40-45°C for 2 hours to eliminate the moisture absorption effect of HPMC.

8. The method for preparing probiotics using a composite gel system according to claim 6, characterized in that, Before step S2, inulin and fructooligosaccharides are mixed evenly and then dried in a vacuum dryer for 20 minutes.

9. The method for preparing probiotics using a composite gel system according to claim 6, characterized in that, In step S4, the freeze-dried product is pulverized to a fineness of 100-200 mesh, sieved, and then collected.

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