A protective digestive enzyme microcapsule for ruminants and its preparation method

Abstract

This invention discloses a protective digestive enzyme microcapsule for ruminants and its preparation method, belonging to the technical field of ruminant feed additives. The microcapsule has a double-layer structure, comprising an enzyme-containing inner microcapsule and an outer ester-based encapsulating material. The inner wall material is composed of a protective colloid and water-soluble dietary fiber. In preparation, the digestive enzyme and the inner wall material are first mixed at 30-40°C to form an enzyme-containing inner layer emulsion, which is then spray-dried at low temperature to obtain inner microcapsule particles. The ester-based encapsulating material is then melt-treated and kept at below 40°C, followed by fluidized bed coating to form a double-layer protective structure. No antioxidant treatment is required throughout the process. The resulting microcapsules are water-insoluble and effectively resist rumen microbial degradation. After passing through the rumen, they release digestive enzymes in the small intestine. The rumen degradation rate is as low as 10.4% after 12 hours, while the small intestine release rate is as high as 95.7%. This method is suitable for the protection of digestive enzymes and complex enzymes, providing a highly efficient and stable enzyme preparation for precise nutritional regulation in ruminants.

Description

Technical Field

[0001] This invention relates to the field of feed additives, and in particular to a protective digestive enzyme microcapsule for ruminants and its preparation method. Background Technology

[0002] Roughage is a crucial component of ruminant feed, accounting for approximately 30%-70% of their intake. Studies have found that grass meal, wheat by-products, corn by-products, and protein raw materials all contain varying amounts of anti-nutritional factors and crude fiber—nutrients that are difficult to digest and absorb—affecting ruminants' nutrient absorption and reducing feed utilization efficiency. In my country, the digestibility of roughage is low, often less than 50%, which not only impacts the production performance of ruminants but also results in significant resource waste.

[0003] Adding exogenous digestive enzymes to feed is one of the important measures to improve feed digestibility. However, due to the special digestive physiology of ruminants—multi-stomach structure, rumen microbial fermentation, and the near-neutral pH environment of the rumen (pH 5.5-7.0)—digestive enzyme preparations suitable for monogastric animals are usually difficult to apply directly to ruminants, lacking specificity and exhibiting poor efficacy. In the digestive tract of monogastric animals (such as chickens and pigs), due to their simple structure and distinct pH gradient (acidic in the stomach and near-neutral in the intestine), exogenous digestive enzymes can directly exert their effects in the stomach or small intestine; while the digestive enzymes of ruminants need to pass through the degradation test of rumen microorganisms before they can exert their effects in the abomasum and small intestine.

[0004] Microencapsulation technology is one of the effective ways to solve the above problems. Microencapsulation technology refers to encapsulating solid or liquid active substances into tiny capsules using natural or synthetic polymer materials, which can protect and control the release of active substances. Through rumen protection technology, especially enzyme coating technology, enzymes can remain stable in the rumen and be released to exert their effects after reaching the small intestine. However, existing microencapsulation technologies mostly use a single capsule wall structure, which has limited barrier effect against rumen microorganisms; at the same time, existing preparation processes often involve high-temperature treatment (such as heating and melting above 60°C, high-temperature spray drying, etc.), while enzymes, as heat-sensitive biomolecules, may undergo irreversible denaturation and inactivation above 40°C. Therefore, how to achieve effective microencapsulation and coating of digestive enzymes under low-temperature conditions while giving them good rumen protection performance is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In view of the above situation and in order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a protective digestive enzyme microcapsule for ruminants and its preparation method, which effectively solves the problem that heat-sensitive digestive enzymes are difficult to achieve complete insolubility in water and effective resistance to rumen microbial degradation under low temperature conditions, thus making them unsuitable for use in ruminants.

[0006] The technical solution is that the present invention includes an inner capsule and an outer ester capsule; by mass percentage, the microcapsule contains 5%-20% digestive enzymes, 30%-60% inner wall material and 10%-40% outer ester capsule.

[0007] Preferably, the digestive enzyme is selected from any one or more of protease, amylase, cellulase, xylanase, glucanase, mannanase, pectinase, phytase, and glucose oxidase, or a complex enzyme formed by combining two or more of the above enzymes.

[0008] Preferably, the inner wall material comprises a protective colloid and water-soluble dietary fiber; the protective colloid comprises any one or more of gum arabic, gelatin, sodium octenyl succinate starch, and sodium alginate; and the water-soluble dietary fiber comprises soluble soybean polysaccharide.

[0009] Preferably, the outer ester capsule material is selected from any one or more of glyceryl monolaurate, glyceryl triboriate, palmitic acid, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, stearic acid, calcium stearate, calcium palmitate, palm wax, and beeswax.

[0010] Preferably, the microcapsules contain less than 5% water by weight; and the microcapsules are insoluble in water, can remain stable in the rumen environment of ruminants, and release digestive enzymes in the intestine after passing through the rumen.

[0011] It also includes a method for preparing protective digestive enzyme microcapsules specifically for ruminants, characterized by comprising the following steps: S1: Mix the prescribed amount of digestive enzyme with the inner wall material in water, and dissolve it by shearing at a temperature of 30-40℃ to obtain an enzyme-containing inner emulsion; S2: Heat and melt the outer ester capsule material according to the formula, and keep it at a temperature of 30-40℃ to obtain the ester capsule material melt liquid; S3: The enzyme-containing inner layer emulsion is dried by spray drying or spray granulation at a low temperature of 30-40℃ to obtain inner layer microcapsule particles. S4: The inner layer microcapsule particles are added to a fluidized bed coating device, and the molten ester capsule material is used as the coating material. Fluidized bed coating is carried out at a temperature of 30-40°C to obtain double-layer protective digestive enzyme microcapsules.

[0012] Preferably, in step S1, the temperature of the shear dissolution is 35-40℃, the rate of shear dissolution is 4.7-7.9 m / s, and the time is 20-40 min; in step S2, the temperature of the heating and melting is 35-40℃.

[0013] Preferably, in step 3, the inlet air temperature of the spray dryer is 40-50℃ and the outlet air temperature is 30-40℃.

[0014] Preferably, in step 4, the temperature of the fluidized bed coating is 30-40℃, and the coating time is 30-120 min.

[0015] Compared with the prior art, the beneficial effects of the present invention are: addressing the problem of digestive enzyme degradation by rumen microorganisms due to the unique multi-stomach physiological structure of ruminants, by constructing a double-layer capsule structure with protective colloids and water-soluble dietary fiber as the inner wall material and a specific ester capsule material as the outer coating, efficient protection of digestive enzymes in the rumen environment and targeted release into the intestine are achieved. Compared with existing rumen-crossing technologies, the core advantages of this invention are as follows: Firstly, the outer ester-based encapsulating material in the double-layered encapsulation structure has strong hydrophobicity and resistance to rumen fluid penetration, making the microcapsules insoluble in water and able to pass completely through the rumen without being degraded by microorganisms, effectively solving the problem of insufficient protection reliability of a single coating layer; secondly, the ester-based encapsulating material is selected from materials such as glyceryl monolaurate, glyceryl triboriate, palmitic acid, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, stearic acid, calcium stearate, calcium palmitate, palm wax, and beeswax. Its low melting temperature allows the entire process of inner emulsion preparation, spray drying granulation, and fluidized bed coating to be completed under mild conditions of 30-40℃, avoiding irreversible damage to the activity of heat-sensitive digestive enzymes such as protease, amylase, cellulase, xylanase, glucanase, mannanase, pectinase, phytase, and glucose oxidase from the source, and the enzyme activity retention rate is significantly higher than that of traditional hot melt coating processes; Meanwhile, the synergistic effect of the protective colloids and soluble soybean polysaccharides in the inner wall material effectively encapsulates and stabilizes the enzyme protein conformation during low-temperature drying, further ensuring the enzyme activity of the product. Furthermore, the process of this invention requires no antioxidant treatment throughout, simplifying the production process, reducing formulation complexity and cost, and resulting in microencapsulated products with good flowability and high stability, which can be directly applied to ruminant feed or premixes, providing a novel, efficient, economical, and safe form of digestive enzyme preparation for precise nutritional regulation in ruminants. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the preparation method of the present invention. Detailed Implementation

[0017] The following describes embodiments of the present invention, but the present invention is not limited thereto. The present invention is not limited to the various configurations described below, and various modifications can be made within the scope of the claims. Embodiments and examples obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0018] To verify the rumen-passing effect and small intestinal release performance of the protective digestive enzyme microcapsules described in this invention, 10 examples with different formulations and process parameters were set up, taking protease as an example.

[0019] General method for preparing inner capsule: The formulated amount of protease and the inner wall material (80 parts by weight of protective colloid and 20 parts by weight of soluble soybean polysaccharide) were mixed in purified water and subjected to high-speed shearing (4.7-7.9 m / s) at 35-40℃ for 20-40 minutes to form a stable enzyme-containing inner layer emulsion. This emulsion was then spray-dried under low-temperature conditions of 45℃ inlet air temperature and 35℃ outlet air temperature to obtain enzyme-containing inner layer microcapsule particles. Example

[0020] Take 100g of the above-mentioned inner layer microcapsule particles (containing 15g of protease), place them in a fluidized bed, and at a fluidization temperature of 35℃, perform bottom spray coating with molten palm wax (the amount used is 20% of the mass of the inner layer microcapsules) for 60 minutes. After cooling, the product is obtained. Example

[0021] Take 100g of the above inner layer microcapsule particles (containing 15g of protease), place them in a fluidized bed, and coat them with molten glyceryl monostearate (25% of the mass of the inner layer microcapsules) at a fluidization temperature of 38℃ for 45 minutes. After cooling, the product is obtained. Example

[0022] The inner wall material was adjusted to be a mixture of gum arabic and soluble soybean polysaccharide in a ratio of 85:15. 100g of inner microcapsule particles (containing 18g of protease) were coated at 40℃ with a mixture of molten stearic acid and palm wax (at a 1:1 weight ratio, with the total amount being 30% of the inner microcapsule mass) for 90 minutes. Example

[0023] The inner wall material is sodium octenyl succinate starch and soluble soybean polysaccharide. 100g of inner microcapsule particles (containing 12g of protease) were coated with glyceryl tartrate (15% of the inner microcapsule mass) at 37℃ for 50 minutes. Example

[0024] The inner wall material is a complex of gelatin and sodium alginate. 100g of inner microcapsule particles (containing 10g of protease) were coated with glyceryl monolaurate (35% of the inner microcapsule mass) at 36℃ for 120 minutes. Example

[0025] The inner wall material is a blend of gum arabic and soluble soybean polysaccharide in a 90:10 ratio, with 5% sodium alginate added to the total solids. 100g of the inner microcapsule particles (containing 20g of protease) were taken and heated to a fluidized bed temperature of 32℃. The outer ester-based encapsulation material (composed of glyceryl monostearate, glyceryl distearate, and beeswax in a 60:25:15 weight ratio) was then completely melted, followed by cooling and precise temperature maintenance at 38℃. This molten liquid was then atomized and bottom-sprayed onto the boiling inner particles. The amount of encapsulation material used was 25% of the inner microcapsule mass, and the coating time was 90 minutes, with temperature fluctuations controlled within ±0.5℃ throughout the process. After solidification, a double-layered protective protease microcapsule was obtained. Example

[0026] Take 100g of inner layer microcapsule particles (containing 15g of protease) and rapidly coat them with calcium stearate (10% of the mass of the inner layer microcapsules) at 40℃ for 30 minutes. Example

[0027] Take 100g of inner layer microcapsule particles (containing 15g of protease) and coat them with a mixture of tristearate and palm wax (40% of the mass of the inner layer microcapsules) at 40℃ for 80 minutes. Example

[0028] The inner wall material uses only gum arabic and no soluble soybean polysaccharides are added. 100g of the inner microcapsule particles are coated with stearic acid at 40℃. Example

[0029] The inner wall material is sodium alginate. The inner microcapsule particles were coated with calcium palmitate (20%) at 35°C, but the uniformity was not precisely controlled during the coating process.

[0030] Experiments using protective digestive enzyme microcapsules, taking protective protease microcapsules as an example: For each trial, 5g of each of the protective protease microcapsules from Examples 1 to 10 were accurately weighed and placed into nylon bags (5cm x 8cm) of known weight. The bags were tied tightly with nylon thread. On the first day of the trial, after the morning feed, the bags were inserted into the rumen sac 50cm deep through a rumen fistula. Eight bags were placed in each cow. Four bags were removed at 12h and 24h. Two bags removed from the rumen of each cow were immediately rinsed with water until the water was completely clear and then dried at 40°C to constant weight. The dried sample was first pulverized, then sonicated for 15 minutes to dissolve the enzymes. The content of protease before and after degradation was determined using the method for determining protease in feed additives in Appendix B of GB / T23527.1. The other two bags were inserted into the small intestine of the cow through a duodenal fistula. The nylon bags were then collected from the cow feces and immediately rinsed with water until the water was completely clear and then dried at 50°C to constant weight. The content of protease in the residue was determined using the method in Appendix B of GB / T23527.1. The rumen degradation rate and small intestinal release rate were calculated separately. The results are shown in the table below.

[0031] Rumen degradation rate = (mass of protective protease before degradation x content of protective protease before degradation - content of protective protease after degradation) (Protein mass x Protective protease content after degradation) / (Protective protease mass before degradation x Protective protease content before degradation) content) x 100%; Small intestinal release rate = (mass of protective protease before degradation x content of protective protease before degradation - fecal collection) (Mass of protective protease residue in nylon bag x Protease content in residue) / (Mass of protective protease before degradation x Mass of protective protease before degradation) (Protein content) x100%;

[0032] As shown in the table above, the ordinary protease in the comparative example was degraded by more than 95% in the rumen within 12 hours, and could hardly reach the small intestine. In contrast, the protective protease microcapsules prepared in Examples 1-10 of this invention showed a significantly reduced rumen degradation rate of only 10.4%–16.1% after 12 hours and a degradation rate of only 12.9%–20.5% after 24 hours, while maintaining a high small intestinal release rate of 86.8%–95.7%. This demonstrates that the double-layered capsule structure successfully resisted degradation by rumen microorganisms.

[0033] In particular, for Example 6, by optimizing the synergistic ratio of gum arabic, soluble soybean polysaccharide, and sodium alginate in the inner wall material, and precisely controlling the combination ratio of the outer ester capsule material (glyceryl monostearate, glyceryl distearate, and beeswax) and the entire process of low-temperature (≤38℃) fluidized bed coating, the densest and most stable double-layer protection was achieved. Its rumen degradation rates at 12 hours and 24 hours were the lowest in all examples (10.4% and 12.9%), while the small intestinal release rate was as high as 95.7%, indicating that the microcapsules can deliver the active enzyme intact through the rumen at the highest proportion and release it efficiently in the intestine, resulting in the best enzyme activity protection effect and making it the optimal implementation method.

[0034] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A protective digestive enzyme microcapsule specifically for ruminants, characterized in that, The microcapsule has a double-layered structure, comprising an inner layer and an outer ester-based encapsulation material; by mass percentage, the microcapsule contains 5%-20% digestive enzymes, 30%-60% inner wall material, and 10%-40% outer ester-based encapsulation material.

2. The protective digestive enzyme microcapsule for ruminants according to claim 1, characterized in that, The digestive enzyme is selected from any one or more of the following: protease, amylase, cellulase, xylanase, glucanase, mannanase, pectinase, phytase, and glucose oxidase, or a complex enzyme formed by combining two or more of the above enzymes.

3. The protective digestive enzyme microcapsule for ruminants according to claim 1, characterized in that, The inner wall material comprises a protective colloid and water-soluble dietary fiber; the protective colloid comprises any one or more of gum arabic, gelatin, sodium octenyl succinate starch, and sodium alginate; the water-soluble dietary fiber comprises soluble soybean polysaccharides.

4. The protective digestive enzyme microcapsule for ruminants according to claim 1, characterized in that, The outer ester capsule material is selected from any one or more of glyceryl monolaurate, glyceryl triboriate, palmitic acid, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, stearic acid, calcium stearate, calcium palmitate, palm wax, and beeswax.

5. The protective digestive enzyme microcapsule for ruminants according to claim 1, characterized in that, The microcapsules also contain less than 5% water by weight; and the microcapsules are insoluble in water, can remain stable in the rumen environment of ruminants, and release digestive enzymes in the intestine after passing through the rumen.

6. A method for preparing the protective digestive enzyme microcapsules for ruminants according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Mix the prescribed amount of digestive enzyme with the inner wall material in water, and dissolve it by shearing at a temperature of 30-40℃ to obtain an enzyme-containing inner emulsion; S2: Heat and melt the outer ester capsule material according to the formula, and keep it at a temperature of 30-40℃ to obtain the ester capsule material melt liquid; S3: The enzyme-containing inner layer emulsion is dried by spray drying or spray granulation at a low temperature of 30-40℃ to obtain inner layer microcapsule particles; S4: The inner layer microcapsule particles are added to a fluidized bed coating device, and the molten ester capsule material is used as the coating material. Fluidized bed coating is carried out at a temperature of 30-40°C to obtain double-layer protective digestive enzyme microcapsules.

7. The preparation method according to claim 6, characterized in that, In step S1, the temperature for shear dissolution is 35-40℃, the rate of shear dissolution is 4.7-7.9 m / s, and the time is 20-40 min; in step S2, the temperature for heating and melting is 35-40℃.

8. The preparation method according to claim 6, characterized in that, In step 3, the inlet air temperature of the spray dryer is 40-50℃ and the outlet air temperature is 30-40℃.

9. The preparation method according to claim 6, characterized in that, In step 4, the temperature of the fluidized bed coating is 30-40℃, and the coating time is 30-120 min.

Images