Mylabris yellow micro-capsule preparation for improving oxidation resistance of feed and preparation method of cantharides yellow micro-capsule preparation

Abstract

The invention provides a canthaxanthin micro-capsule preparation for improving the oxidation resistance of a feed and a preparation method of the canthaxanthin micro-capsule preparation. The preparation raw materials comprise 0.5 to 2.0 parts of canthaxanthin, 25 to 35 parts of a composite modified starch wall material, 3 to 8 parts of an oryzanol-tocopherol compound, 10 to 18 parts of a dispersion medium, 28 to 38 parts of maltodextrin, 1.5 to 4.0 parts of hydrophobic modified silicon dioxide, 1.8 to 4.5 parts of an emulsion stabilizer and 0.3 to 0.8 part of tea polyphenol. According to the invention, the components cooperate with each other, so that the preparation has excellent oxidation resistance, good dispersion uniformity and storage stability, and the oxidation resistance of the feed can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of feed additive technology, specifically to a cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method. Background Technology

[0002] Feed typically contains various fat-soluble nutrients such as oils and vitamins, which are crucial for the growth and development of farmed animals. However, during the high-temperature environment of feed processing and subsequent storage, these nutrients are highly susceptible to oxidative degradation due to external factors such as oxygen and humidity. This not only leads to nutrient loss and reduces the nutritional value of the feed but may also produce oxidation products that harm the health of farmed animals. Therefore, improving the antioxidant properties of feed is one of the key needs of the feed industry. Cantharidin, as a substance with both coloring and antioxidant activity, is often used as a feed additive. To prolong its duration of action, the industry often uses microencapsulation technology to encapsulate it, reducing damage from the external environment.

[0003] Existing cantharidin microencapsulation formulations have limited antioxidant protection capabilities, making it difficult to simultaneously ensure the stability of cantharidin and fat-soluble nutrients in feed. The retention rate of active ingredients is low after high-temperature processing and long-term storage. Furthermore, some formulations exhibit poor storage stability, easily absorbing moisture and clumping, affecting their uniform dispersion in feed and hindering their ability to fully exert their antioxidant effects. Therefore, developing a cantharidin microencapsulation formulation with excellent antioxidant protection, good storage stability, and the ability to effectively improve the overall antioxidant performance of feed has become an urgent technical challenge. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This application discloses a cantharidin microcapsule formulation for improving the antioxidant properties of feed. The raw materials for its preparation, by weight, include: 0.5-2.0 parts of cantharidin, 25-35 parts of composite modified starch wall material, 3-8 parts of oryzanol-tocopherol complex, 10-18 parts of dispersion medium, 28-38 parts of maltodextrin, 1.5-4.0 parts of hydrophobic modified silica, 1.8-4.5 parts of emulsifying stabilizer, and 0.3-0.8 parts of tea polyphenols.

[0007] Using the above technical solutions, cantharidin can exert its antioxidant effect; the composite modified starch wall material can encapsulate and isolate the internal components of the formulation, reducing the impact of the external environment on the active ingredients; the oryzanol-tocopherol complex synergistically works with cantharidin to exert antioxidant effects, enhancing the overall free radical scavenging ability of the formulation; the dispersion medium promotes uniform dispersion of each component in the system; the emulsifying stabilizer maintains the stability of the formulation system, avoiding stratification or precipitation; maltodextrin assists in formulation shaping and improves the physical stability of the formulation; hydrophobically modified silica reduces the hygroscopicity of the formulation and improves its storage stability; and tea polyphenols further enhance the antioxidant effect of the formulation. The synergistic effect of these components gives the formulation excellent antioxidant properties, along with good dispersion uniformity and storage stability, effectively improving the antioxidant capacity of feed.

[0008] Preferably, the raw materials for preparing the composite modified starch wall material, by weight, include: 95-105 parts starch, 300-450 parts deionized water, 3-5 parts octenyl succinic anhydride, 10-15 parts trehalose, 1-2 parts citric acid, and 0.5-1.0 parts initiator; wherein the starch is either glutinous corn starch or potato starch, and the initiator is either ammonium persulfate or azobisisobutyronitrile.

[0009] Using the above technical solution, glutinous corn starch or potato starch serves as the base material to provide the basic framework structure, while deionized water provides the medium environment for the dissolution and reaction of each raw material. Octenyl succinic anhydride can undergo esterification with starch to introduce hydrophobic ester groups, and trehalose can undergo grafting reaction with starch under the action of an initiator (ammonium persulfate or azobisisobutyronitrile) to form a cross-linked structure. Citric acid can promote the esterification and grafting reactions. With the synergistic effect of each component, the prepared composite modified starch wall material has good hydrophobicity, structural stability and barrier properties, and can effectively encapsulate and isolate the core components.

[0010] Preferably, the preparation method of the composite modified starch wall material includes the following steps:

[0011] 1) Add starch to deionized water, stir evenly at 200-400 r / min, heat to 75-85℃, gelatinize for 25-35 min, cool to 35-45℃, and adjust the pH of the system to 7.0-8.0 with 4wt%-5wt% sodium hydroxide solution;

[0012] 2) Under constant temperature of 35-45℃ and stirring at 300-500r / min, slowly add octenyl succinic anhydride to the system obtained in step 1), controlling the addition time to be 30-60min. After the addition is completed, continue to react under the above conditions for 2-4h. During this period, maintain the pH of the system at 7.0-8.0 by intermittently adding 4wt%-5wt% sodium hydroxide solution or 4wt%-5wt% citric acid solution.

[0013] 3) Add trehalose, citric acid and initiator to the system obtained in step 2), heat to 50-60℃ and keep warm, stir at 300-400r / min for 3-5h to form octenyl succinate-trehalose grafted modified starch.

[0014] 4) Adjust the pH of the octenyl succinate-trehalose grafted modified starch system to 6.5-7.0 with 4wt%-5wt% citric acid solution. Concentrate under reduced pressure to a solid content of 30-40% under vacuum conditions of -0.06~-0.09MPa and 45-55℃. Then spray dry the product. After pulverizing, pass the product through a 100-120 mesh sieve to obtain the composite modified starch wall material.

[0015] Using the above technical solution, starch is first gelatinized to extend the molecular chains, then esterified with octenyl succinic anhydride under suitable pH and temperature conditions. Following this, trehalose, citric acid, and an initiator are added for a grafting reaction, effectively forming octenyl succinic anhydride-grafted modified starch. Subsequent vacuum concentration to remove excess moisture, spray drying, and pulverization and sieving processes yield a solid product with uniform particle size. The synergistic effect of these steps gives the prepared composite modified starch wall material good hydrophobicity and structural stability, enabling effective encapsulation and isolation of the core components. Simultaneously, the uniform particle size helps improve its dispersibility in microencapsulation formulations.

[0016] Preferably, in step 4), the spray drying conditions are: inlet air temperature 170-190℃, outlet air temperature 80-90℃, atomization pressure 0.3-0.5MPa, and feed rate 10-15mL / min.

[0017] Using the above technical solution, an inlet air temperature of 170-190℃ can quickly provide the heat required for drying the material, promoting rapid evaporation of moisture; an outlet air temperature of 80-90℃ can prevent excessively high temperatures from causing thermal degradation or oxidation of components such as the composite modified starch wall material and cantharidin, ensuring the integrity of the microcapsule structure and the stability of the effective ingredients; an atomization pressure of 0.3-0.5MPa can cause the concentrated material to form fine and uniform droplets, increasing the contact area between the material and the hot air, improving drying efficiency and drying uniformity; a feed rate of 10-15mL / min matches the above temperature and pressure parameters, ensuring that the droplets obtain sufficient drying time in the drying tower, ultimately obtaining a fully dried, uniformly sized solid composite modified starch wall material product, while maintaining the hydrogen bond network structure and coating performance of the wall material.

[0018] Preferably, the raw materials for preparing the oryzanol-tocopherol complex, by weight, include: 30-50 parts of oryzanol, 30-60 parts of tocopherol, 100-150 parts of anhydrous ethanol, and 3-8 parts of auxiliary molding agent, wherein the auxiliary molding agent is one of glyceryl monostearate, beeswax, or stearic acid, and the tocopherol is one of α-tocopherol, γ-tocopherol, or tocopherol acetate.

[0019] Using the above technical solution, oryzanol combined with any one of α-tocopherol, γ-tocopherol, or tocopherol acetate can exert a synergistic antioxidant effect and enhance the overall antioxidant efficacy. Anhydrous ethanol can fully dissolve oryzanol, tocopherol, and auxiliary molding agents to form a homogeneous system, providing a basis for the preparation of the complex. Any one of glyceryl monostearate, beeswax, or stearic acid can be used as an auxiliary molding agent to promote the formation of a stable solid form of the dissolved raw materials, avoid component separation, and finally obtain a oryzanol-tocopherol complex with stable morphology and good antioxidant properties.

[0020] Preferably, the preparation method of the oryzanol-tocopherol complex includes the following steps:

[0021] (1) Add oryzanol, tocopherol and auxiliary forming agent to anhydrous ethanol and treat for 20-30 min at 60-70℃ and 400-600r / min stirring to form a uniform and stable dispersion system;

[0022] (2) The dispersion system obtained in step (1) is maintained at 60-70℃ and 300-400r / min, and then anhydrous ethanol is recovered by vacuum distillation under vacuum conditions of -0.08~-0.10MPa to form a eutectic solid precursor;

[0023] (3) The eutectic solid precursor was vacuum dried at 50-60℃ and vacuum degree -0.08~-0.10MPa for 2-4h to remove residual ethanol, and then pulverized and passed through a 90-110 mesh sieve to obtain oryzanol-tocopherol complex.

[0024] Using the above technical solution, this preparation method allows oryzanol, tocopherol, and auxiliary molding agents to be fully mixed in anhydrous ethanol to form a uniform and stable dispersion system. The temperature conditions of 60-70℃ combined with vacuum distillation at a specific vacuum level can effectively recover anhydrous ethanol without avoiding oxidation of the raw materials, and promote the formation of a eutectic solid precursor through the interaction between raw material molecules. Subsequent vacuum drying can remove residual ethanol, ensuring the purity of the complex. After pulverization and sieving, a oryzanol-tocopherol complex with uniform particle size is obtained, which is beneficial for the uniform dispersion of the complex in the subsequent microcapsule formulation preparation, while ensuring the stability of its eutectic structure and the performance of its antioxidant properties.

[0025] Preferably, the dispersion medium is a mixture of medium-chain triglycerides (MCT) and high-oleic sunflower seed oil in a mass ratio of 2:1 to 1:1.

[0026] Using the above technical solution, the dispersion medium formed by combining MCT and high-oleic sunflower seed oil can quickly dissolve cantharidin and oryzanol-tocopherol complex, while reducing the viscosity of the oil phase, creating favorable conditions for subsequent emulsification. In addition, high-oleic sunflower seed oil can exert an antioxidant effect, reducing the oxidation loss of each component during the preparation process, which is conducive to the formation of a stable oil phase system and ensuring the preparation effect and antioxidant performance of cantharidin microcapsule formulation.

[0027] Preferably, the emulsifying stabilizer is a compound of sucrose fatty acid ester and lecithin in a mass ratio of 0.5:1 to 1.5:1.

[0028] Using the above technical solution, the emulsifying stabilizer formed by the compounding of sucrose fatty acid ester and lecithin can adjust the hydrophilic and lipophilic balance of the system, enhance the dispersion stability of the oil phase in the aqueous phase, inhibit the emulsion layering or demulsification, and facilitate the formation of a uniformly dispersed O / W type emulsion. This provides a stable precursor for subsequent high-pressure homogenization and spray drying molding, ensuring the structural integrity and dispersion uniformity of the cantharidin microcapsule formulation.

[0029] This application also discloses a method for preparing a cantharidin microcapsule formulation for improving the antioxidant properties of feed, comprising the following steps:

[0030] S1. Oil phase preparation: Under nitrogen micro-positive pressure protection, add dispersion medium to the reaction vessel, heat to 60-80℃, add cantharidin and oryzanol-tocopherol complex, stir at 500-800r / min for 20-40min to form a uniform oil phase;

[0031] S2. Aqueous phase preparation: Add deionized water to another reactor, the amount of which is 3-5 times the weight of the composite modified starch wall material. Heat to 40-55℃, add the composite modified starch wall material, maltodextrin, hydrophobic modified silica, emulsifying stabilizer and tea polyphenols, and stir at 300-500 r / min for 30-50 min to form a uniform and stable aqueous phase system.

[0032] S3. Emulsification treatment: Under nitrogen protection, the oil phase is slowly added dropwise to the aqueous phase at a rate of 5-10 mL / min. After the addition is complete, the high-speed shear emulsifier is turned on and emulsified at a speed of 8000-12000 r / min for 15-30 min to form an O / W type emulsion with an average particle size of 30-60 μm.

[0033] S4. High-pressure homogenization and refining treatment: The emulsion is fed into a high-pressure homogenizer, and the pressure is controlled at 30-50MPa, the temperature at 40-50℃, and the homogenization is carried out 1-2 times to refine the average particle size of the emulsion to 3-8μm.

[0034] S5. Spray drying and molding: The emulsion processed in step S4 is fed into a spray dryer, and the inlet air temperature is controlled at 180-200℃, the outlet air temperature at 85-95℃, the feed rate at 10-20mL / min, and the atomization pressure at 0.2-0.4MPa. After drying, it is passed through a 50-70 mesh sieve, sealed and stored to obtain the cantharides microcapsule preparation.

[0035] Using the above technical solution, nitrogen micro-positive pressure protection can reduce the oxidation loss of components such as cantharidin and oryzanol-tocopherol complex during the preparation process; the oil phase and aqueous phase are prepared under specific temperature and stirring conditions, which can fully dissolve and disperse the components to form a uniform and stable two-phase system; the slow droplet addition of the oil phase combined with high-speed shear emulsification can form a stable O / W type emulsion, and the subsequent high-pressure homogenization and refining treatment can further reduce the particle size of the emulsion, improve the uniformity of the system, and facilitate the full coating of cantharidin by the composite modified starch wall material; the temperature and pressure control of spray drying can realize the rapid drying and shaping of the emulsion, and after sieving, a powdered cantharidin microcapsule formulation with uniform particle size is obtained. Sealed storage can maintain the stability of the formulation performance, and ultimately ensure the antioxidant effect and application stability of the formulation.

[0036] Preferably, in step S1, the nitrogen micro-positive pressure protection is controlled by a pressure transmitter and an automatic regulating valve to maintain the gauge pressure at 0.01-0.03 MPa; in step S4, the throughput of the high-pressure homogenization and refining treatment is 100-200 L / h.

[0037] Using the above technical solution, the nitrogen micro-positive pressure of 0.01-0.03MPa is stably controlled by a pressure transmitter and an automatic regulating valve, which can effectively prevent air from entering the oil phase system and reduce the oxidation loss of cantharidin and oryzanol-tocopherol complex. The high-pressure homogenization and refining process with a throughput of 100-200L / h is matched with the set pressure and temperature parameters, which can ensure that the emulsion receives sufficient high pressure during the process to achieve uniform particle size refining, while maintaining stable processing efficiency and ensuring the coating effect of the microcapsule wall material on the core components and the consistency of the formulation performance.

[0038] The beneficial effects of this invention are as follows:

[0039] Cantharidin exerts its antioxidant properties, while the composite modified starch wall material can encapsulate and isolate the internal components of the formulation, reducing the impact of the external environment on the active ingredients. The oryzanol-tocopherol complex synergistically works with cantharidin to enhance the overall free radical scavenging ability of the formulation. The dispersion medium promotes uniform dispersion of each component in the system, while the emulsifying stabilizer maintains the stability of the formulation system, preventing stratification or precipitation. Maltodextrin assists in formulation shaping and improves the physical stability of the formulation. Hydrophobically modified silica reduces the hygroscopicity of the formulation, improving its storage stability. Tea polyphenols further enhance the antioxidant effect of the formulation. The synergistic effect of these components gives the formulation excellent antioxidant properties, along with good dispersion uniformity and storage stability, effectively improving the antioxidant capacity of feed.

[0040] Glutinous corn starch or potato starch serves as the base material to provide the basic framework structure, while deionized water provides the medium environment for the dissolution and reaction of each raw material. Octenyl succinic anhydride can undergo esterification with starch to introduce hydrophobic ester groups. Trehalose can undergo grafting reaction with starch under the action of initiators (ammonium persulfate or azobisisobutyronitrile) to form a cross-linked structure. Citric acid can promote the esterification and grafting reactions. With the synergistic effect of each component, the prepared composite modified starch wall material has good hydrophobicity, structural stability and barrier properties, and can effectively encapsulate and isolate the core components. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0042] Specific information on the raw materials used in the embodiments of this invention is shown in Table 1:

[0043] Table 1. Raw material names and sources

[0044] Components Specifications Manufacturer Information Cantharides Purity ≥ 98% Zhejiang NHU Co., Ltd., CAS No.: 514-78-3 medium-chain triglycerides Purity ≥99%, food grade Guangdong Hongyou Biotechnology Co., Ltd. High oleic sunflower seed oil Purity ≥ 99% Jishui County Yikang Natural Fragrance Oil Refining Plant, CAS No.: 8001-21-6 maltodextrin Purity 99.9%, DE value 15-20 Jiangsu Jiujia Biotechnology Co., Ltd., CAS No.: 9050-36-6 Hydrophobic modified silica 99.8% purity Evonik Industries, AEROSIL R972 Sucrose fatty acid esters Purity ≥ 99%, HLB value 14-16 Shandong Fengtai Biotechnology Co., Ltd., CAS No.: 37318-31-3 Lecithin Feed grade, phosphatidylcholine content ≥60% Zhengzhou Zhengnuo Food Additives Co., Ltd. Tea polyphenols Purity ≥ 95% Fufeng Snowtech Biotechnology Co., Ltd. starch Food-grade glutinous corn starch or potato starch The glutinous corn starch was purchased from Shandong Fuyang Biotechnology Co., Ltd., and the potato starch was purchased from Inner Mongolia Nailun Agricultural Technology Co., Ltd. Octenylsuccinic anhydride Purity 98%, dilute to 30% by mass with anhydrous ethanol before use. Shanghai Maclean Biochemical Technology Co., Ltd., CAS No.: 42482-06-4 Trehalose Feed grade, 99.9% purity Zhengzhou Jiuting Chemical Products Co., Ltd., CAS No.: 99-20-7 Citric acid Analytical Pure Sinopharm Chemical Reagent Co., Ltd. Initiator Ammonium persulfate (purity ≥ 98.5%) or azobisisobutyronitrile Ammonium persulfate was purchased from Wuhan Jiyesheng Chemical Co., Ltd., and azobisisobutyronitrile was purchased from Jinan World Chemical Co., Ltd. Oryzanol Purity ≥ 99% Wuhan Dingxintong Pharmaceutical Co., Ltd., CAS No.: 11042-64-1 Tocopherol α-Tocopherol, γ-Tocopherol, or Tocopherol Acetate Jiangsu Jiujia Biotechnology Co., Ltd. Anhydrous ethanol Analytical Pure Sinopharm Chemical Reagent Co., Ltd. Auxiliary molding agent Glyceryl monostearate, beeswax, or stearic acid Glyceryl monostearate was purchased from Shandong Fuwangjia Biotechnology Co., Ltd., beeswax from Zhengzhou Dewang Chemical Products Co., Ltd., and stearic acid from Hubei Chengfeng Chemical Co., Ltd.

[0045] Example 1:

[0046] This embodiment discloses a cantharidin microcapsule formulation for improving the antioxidant properties of feed. The raw materials, by weight, include: 0.5 parts cantharidin, 25 parts composite modified starch wall material, 3 parts oryzanol-tocopherol complex, 10 parts dispersion medium, 28 parts maltodextrin, 1.5 parts hydrophobically modified silica, 1.8 parts emulsifying stabilizer, and 0.3 parts tea polyphenols. The dispersion medium is a mixture of MCT and high-oleic sunflower seed oil at a mass ratio of 2:1. The emulsifying stabilizer is a mixture of sucrose fatty acid ester and lecithin at a mass ratio of 0.5:1.

[0047] The raw materials for preparing the composite modified starch wall material, by weight, include: 95 parts starch, 300 parts deionized water, 3 parts octenyl succinic anhydride, 10 parts trehalose, 1 part citric acid, and 0.5 parts initiator; wherein the starch is glutinous corn starch and the initiator is ammonium persulfate.

[0048] The preparation method of composite modified starch wall material includes the following steps:

[0049] 1) Add starch to deionized water, stir evenly at 200 r / min, heat to 75℃, gelatinize for 25 min, cool to 35℃, and adjust the pH of the system to 7.0-8.0 with 4 wt% sodium hydroxide solution;

[0050] 2) Under constant temperature of 35℃ and stirring at 300r / min, slowly add octenyl succinic anhydride to the system obtained in step 1), controlling the addition time to be 30min. After the addition is completed, continue to react under the above conditions for 2h. During this period, the pH of the system is maintained at 7.0-8.0 by intermittently adding 4wt% sodium hydroxide solution or 4wt% citric acid solution.

[0051] 3) Add trehalose, citric acid and initiator to the system obtained in step 2), heat to 50°C and keep warm, stir at 300 r / min for 3 h to form octenyl succinate-trehalose grafted modified starch.

[0052] 4) The pH of the octenyl succinate-trehalose grafted modified starch system was adjusted to 6.5-7.0 with 4wt% citric acid solution. The solid content was concentrated to 30% under reduced pressure at a vacuum of -0.06MPa and a temperature of 45℃. Then, it was spray dried with an inlet air temperature of 170℃, an outlet air temperature of 80℃, an atomization pressure of 0.3MPa, and a feed rate of 10mL / min. The dried product was pulverized and passed through a 100-mesh sieve to obtain the composite modified starch wall material.

[0053] The raw materials for preparing the oryzanol-tocopherol complex, by weight, include: 30 parts oryzanol, 30 parts tocopherol, 100 parts anhydrous ethanol, and 3 parts auxiliary molding agent, wherein the auxiliary molding agent is glyceryl monostearate and the tocopherol is α-tocopherol.

[0054] The preparation method of the oryzanol-tocopherol complex includes the following steps:

[0055] (1) Add oryzanol, tocopherol and auxiliary forming agent to anhydrous ethanol and treat for 20 min at 60℃ and 400 r / min stirring to form a uniform and stable dispersion system;

[0056] (2) The dispersion system obtained in step (1) is maintained at 60°C and 300 r / min with stirring. Then, anhydrous ethanol is recovered by vacuum distillation under vacuum of -0.08 MPa to form a eutectic solid precursor.

[0057] (3) The eutectic solid precursor was vacuum dried at 50°C and -0.08 MPa for 2 h to remove residual ethanol. After pulverizing, it was passed through a 90-mesh sieve to obtain the oryzanol-tocopherol complex.

[0058] This embodiment also discloses a method for preparing a cantharidin microcapsule formulation for improving the antioxidant properties of feed, comprising the following steps:

[0059] S1. Oil phase preparation: Under nitrogen micro-positive pressure protection, the pressure is controlled at 0.01MPa by a pressure transmitter and an automatic regulating valve. Dispersion medium is added to the reactor, the temperature is raised to 60℃, cantharidin and oryzanol-tocopherol complex are added, and the mixture is stirred at 500r / min for 20min to form a uniform oil phase.

[0060] S2. Aqueous phase preparation: Add deionized water to another reactor, the amount of which is 3 times the weight of the composite modified starch wall material. Heat to 40°C and add the composite modified starch wall material, maltodextrin, hydrophobic modified silica, emulsifying stabilizer and tea polyphenols. Stir at 300 r / min for 30 min to form a uniform and stable aqueous phase system.

[0061] S3. Emulsification treatment: Under nitrogen protection, the oil phase is slowly added dropwise to the aqueous phase at a rate of 5 mL / min. After the addition is complete, the high-speed shear emulsifier is turned on and emulsified at a speed of 8000 r / min for 15 min to form an O / W type emulsion with an average particle size of 30-60 μm.

[0062] S4. High-pressure homogenization and refinement treatment: The emulsion is fed into a high-pressure homogenizer, and the pressure is controlled at 30MPa, the temperature at 40℃, and the homogenization is carried out once (the throughput is 100L / h) to refine the average particle size of the emulsion to 3-8μm.

[0063] S5. Spray drying and molding: The emulsion processed in step S4 is fed into a spray dryer, and the inlet air temperature is controlled at 180℃, the outlet air temperature at 85℃, the feed rate at 10mL / min, and the atomization pressure at 0.2MPa. After drying, it is passed through a 50-mesh sieve, sealed and stored to obtain the cantharides microcapsule preparation.

[0064] Example 2:

[0065] This embodiment discloses a cantharidin microcapsule formulation for improving the antioxidant properties of feed. The raw materials, by weight, include: 2.0 parts cantharidin, 35 parts composite modified starch wall material, 8 parts oryzanol-tocopherol complex, 18 parts dispersion medium, 38 parts maltodextrin, 4.0 parts hydrophobically modified silica, 4.5 parts emulsifying stabilizer, and 0.8 parts tea polyphenols. The dispersion medium is a mixture of MCT and high-oleic sunflower seed oil in a 1:1 mass ratio. The emulsifying stabilizer is a mixture of sucrose fatty acid ester and lecithin in a 1.5:1 mass ratio.

[0066] The raw materials for preparing the composite modified starch wall material, by weight, include: 105 parts starch, 450 parts deionized water, 5 parts octenyl succinic anhydride, 15 parts trehalose, 2 parts citric acid, and 1.0 part initiator; wherein, the starch is potato starch and the initiator is azobisisobutyronitrile.

[0067] The preparation method of composite modified starch wall material includes the following steps:

[0068] 1) Add starch to deionized water, stir evenly at 400 r / min, heat to 85℃, gelatinize for 35 min, cool to 45℃, and adjust the pH of the system to 7.0-8.0 with 5wt% sodium hydroxide solution;

[0069] 2) Under constant temperature of 45℃ and stirring at 500r / min, slowly add octenyl succinic anhydride to the system obtained in step 1), controlling the addition time to be 60min. After the addition is completed, continue to react under the above conditions for 4h. During this period, the pH of the system is maintained at 7.0-8.0 by intermittently adding 5wt% sodium hydroxide solution or 5wt% citric acid solution.

[0070] 3) Add trehalose, citric acid and initiator to the system obtained in step 2), heat to 60°C and keep warm, stir at 400 r / min for 5 h to form octenyl succinate-trehalose grafted modified starch.

[0071] 4) Adjust the pH of the octenyl succinate-trehalose grafted modified starch system to 6.5-7.0 with 5wt% citric acid solution. Concentrate under reduced pressure to a solid content of 40% under vacuum conditions of -0.09MPa and 55℃. Then spray dry: inlet air temperature 190℃, outlet air temperature 90℃, atomization pressure 0.5MPa, feed rate 15mL / min. After drying, the product is pulverized and passed through a 120-mesh sieve to obtain the composite modified starch wall material.

[0072] The raw materials for preparing the oryzanol-tocopherol complex, by weight, include: 50 parts oryzanol, 60 parts tocopherol, 150 parts anhydrous ethanol, and 8 parts auxiliary molding agent, which is beeswax and γ-tocopherol.

[0073] The preparation method of the oryzanol-tocopherol complex includes the following steps:

[0074] (1) Add oryzanol, tocopherol and auxiliary forming agent to anhydrous ethanol and treat for 30 min at 70℃ and 600 r / min stirring to form a uniform and stable dispersion system;

[0075] (2) The dispersion system obtained in step (1) is maintained at 70°C and 400 r / min with stirring. Then, anhydrous ethanol is recovered by vacuum distillation under vacuum of -0.10 MPa to form a eutectic solid precursor.

[0076] (3) The eutectic solid precursor was vacuum dried at 60°C and vacuum degree -0.10MPa for 4h to remove residual ethanol, and then pulverized and passed through a 110-mesh sieve to obtain the oryzanol-tocopherol complex.

[0077] This embodiment also discloses a method for preparing a cantharidin microcapsule formulation for improving the antioxidant properties of feed, comprising the following steps:

[0078] S1. Oil phase preparation: Under nitrogen micro-positive pressure protection, the pressure is controlled to be 0.03MPa by a pressure transmitter and an automatic regulating valve. Dispersion medium is added to the reactor, the temperature is raised to 80℃, cantharidin and oryzanol-tocopherol complex are added, and the mixture is stirred at 800r / min for 40min to form a uniform oil phase.

[0079] S2. Aqueous phase preparation: Add deionized water to another reactor, the amount of which is 5 times the weight of the composite modified starch wall material. Heat to 55°C and add the composite modified starch wall material, maltodextrin, hydrophobic modified silica, emulsifying stabilizer and tea polyphenols. Stir at 500 r / min for 50 min to form a uniform and stable aqueous phase system.

[0080] S3. Emulsification treatment: Under nitrogen protection, the oil phase is slowly added dropwise to the aqueous phase at a rate of 10 mL / min. After the addition is complete, the high-speed shear emulsifier is turned on and emulsified at a speed of 12000 r / min for 30 min to form an O / W type emulsion with an average particle size of 30-60 μm.

[0081] S4. High-pressure homogenization and refining treatment: The emulsion is fed into a high-pressure homogenizer, and the pressure is controlled at 50MPa and the temperature at 50℃. The homogenizer is circulated and homogenized twice (throughput is 200L / h) to refine the average particle size of the emulsion to 3-8μm.

[0082] S5. Spray drying and molding: The emulsion processed in step S4 is fed into a spray dryer, and the inlet air temperature is controlled at 200℃, the outlet air temperature at 95℃, the feed rate at 20mL / min, and the atomization pressure at 0.4MPa. After drying, it is passed through a 70-mesh sieve, sealed and stored to obtain the cantharides microcapsule preparation.

[0083] Example 3:

[0084] This embodiment discloses a cantharidin microcapsule formulation for improving the antioxidant properties of feed. The raw materials, by weight, include: 1 part cantharidin, 30 parts composite modified starch wall material, 5 parts oryzanol-tocopherol complex, 14 parts dispersion medium, 33 parts maltodextrin, 2.5 parts hydrophobically modified silica, 3.0 parts emulsifying stabilizer, and 0.5 parts tea polyphenols. The dispersion medium is a mixture of MCT and high-oleic sunflower seed oil at a mass ratio of 1.5:1. The emulsifying stabilizer is a mixture of sucrose fatty acid ester and lecithin at a mass ratio of 1:1.

[0085] The raw materials for preparing the composite modified starch wall material, by weight, include: 100 parts starch, 370 parts deionized water, 4 parts octenyl succinic anhydride, 12 parts trehalose, 1.5 parts citric acid, and 0.7 parts initiator; wherein the starch is potato starch and the initiator is ammonium persulfate.

[0086] The preparation method of composite modified starch wall material includes the following steps:

[0087] 1) Add starch to deionized water, stir evenly at 300 r / min, heat to 80℃, gelatinize for 30 min, cool to 40℃, and adjust the pH of the system to 7.0-8.0 with 4.5 wt% sodium hydroxide solution;

[0088] 2) Under constant temperature of 40℃ and stirring at 400r / min, slowly add octenyl succinic anhydride to the system obtained in step 1), controlling the addition time to be 45min. After the addition is completed, continue to react under the above conditions for 3h. During this period, the pH of the system is maintained at 7.0-8.0 by intermittently adding 4.5wt% sodium hydroxide solution or 4.5wt% citric acid solution.

[0089] 3) Add trehalose, citric acid and initiator to the system obtained in step 2), heat to 55°C and keep warm, stir at 350 r / min for 4 h to form octenyl succinate-trehalose grafted modified starch.

[0090] 4) The pH of the octenyl succinate-trehalose grafted modified starch system was adjusted to 6.5-7.0 with 4.5 wt% citric acid solution. The system was concentrated under reduced pressure to a solid content of 35% at a vacuum of -0.08 MPa and a temperature of 50°C. Then, it was spray dried with an inlet air temperature of 180°C, an outlet air temperature of 85°C, an atomization pressure of 0.4 MPa, and a feed rate of 12 mL / min. The dried product was pulverized and passed through a 110-mesh sieve to obtain the composite modified starch wall material.

[0091] The raw materials for preparing the oryzanol-tocopherol complex, by weight, include: 40 parts oryzanol, 45 parts tocopherol, 120 parts anhydrous ethanol, and 5 parts auxiliary molding agent, wherein the auxiliary molding agent is stearic acid and the tocopherol is tocopherol acetate.

[0092] The preparation method of the oryzanol-tocopherol complex includes the following steps:

[0093] (1) Add oryzanol, tocopherol and auxiliary forming agent to anhydrous ethanol and treat for 25 min at 65℃ and 500 r / min stirring to form a uniform and stable dispersion system;

[0094] (2) The dispersion system obtained in step (1) is maintained at 65°C and 350 r / min with stirring. Then, anhydrous ethanol is recovered by vacuum distillation under vacuum of -0.09 MPa to form a eutectic solid precursor.

[0095] (3) The eutectic solid precursor was vacuum dried at 55°C and -0.09 MPa for 3 h to remove residual ethanol. After pulverizing, it was passed through a 100-mesh sieve to obtain the oryzanol-tocopherol complex.

[0096] This embodiment also discloses a method for preparing a cantharidin microcapsule formulation for improving the antioxidant properties of feed, comprising the following steps:

[0097] S1. Oil phase preparation: Under nitrogen micro-positive pressure protection, the pressure is controlled at 0.02MPa by a pressure transmitter and an automatic regulating valve. Dispersion medium is added to the reactor, the temperature is raised to 70℃, cantharidin and oryzanol-tocopherol complex are added, and the mixture is stirred at 650r / min for 30min to form a uniform oil phase.

[0098] S2. Aqueous phase preparation: Add deionized water to another reactor, the amount of which is 4 times the weight of the composite modified starch wall material. Heat to 50°C and add the composite modified starch wall material, maltodextrin, hydrophobic modified silica, emulsifying stabilizer and tea polyphenols. Stir at 400 r / min for 40 min to form a uniform and stable aqueous phase system.

[0099] S3. Emulsification treatment: Under nitrogen protection, the oil phase is slowly added dropwise to the aqueous phase at a rate of 7 mL / min. After the addition is complete, the high-speed shear emulsifier is turned on and emulsified at a speed of 10000 r / min for 25 min to form an O / W type emulsion with an average particle size of 30-60 μm.

[0100] S4. High-pressure homogenization and refinement treatment: The emulsion is fed into a high-pressure homogenizer, and the pressure is controlled at 40MPa, the temperature at 45℃, and the homogenization is carried out twice (the throughput is 150L / h) to refine the average particle size of the emulsion to 3-8μm.

[0101] S5. Spray drying and molding: The emulsion processed in step S4 is fed into a spray dryer, and the inlet air temperature is controlled at 190℃, the outlet air temperature at 90℃, the feed rate at 15mL / min, and the atomization pressure at 0.3MPa. After drying, it is passed through a 60-mesh sieve, sealed and stored to obtain the cantharides microcapsule preparation.

[0102] Comparative Example 1:

[0103] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that ordinary octenyl succinate starch ester is used to replace the composite modified starch wall material in an equal amount. The ordinary octenyl succinate starch ester was purchased from Condis Chemical (Hubei) Co., Ltd. and has a purity of 99%.

[0104] Comparative Example 2:

[0105] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that a single tocopherol acetate (tocopherol) is used to replace the oryzanol-tocopherol complex in an equal amount.

[0106] Comparative Example 3:

[0107] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that hydrophobic modified silica is not added.

[0108] Comparative Example 4:

[0109] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that no tea polyphenols are added.

[0110] Comparative Example 5:

[0111] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the emulsifying stabilizer used is entirely sucrose fatty acid ester, and no lecithin is added.

[0112] Comparative Example 6:

[0113] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the dispersion medium used is MCT and no high-oleic sunflower oil is added.

[0114] Comparative Example 7:

[0115] A cantharidin microcapsule preparation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this preparation and Example 3 is that the high-pressure homogenization and refining step is not performed in the preparation method of the cantharidin microcapsule preparation.

[0116] Comparative Example 8:

[0117] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the composite modified starch wall material is only subjected to octenyl succinate esterification treatment and does not undergo trehalose grafting modification.

[0118] Comparative Example 9:

[0119] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the mass ratio of oryzanol to tocopherol in the oryzanol-tocopherol complex is 4:1.

[0120] Comparative Example 10:

[0121] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the inlet air temperature for spray drying is controlled at 160-165°C.

[0122] Comparative Example 11:

[0123] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the high-pressure homogenization pressure is controlled at 20-25 MPa.

[0124] Comparative Example 12:

[0125] A cantharidin microcapsule formulation for improving the antioxidant properties of feed and its preparation method are disclosed. The only difference between this formulation and Example 3 is that the nitrogen protection pressure is controlled at 0.003-0.005 MPa.

[0126] The cantharidin microcapsule formulations obtained in Examples 1-3 and Comparative Examples 1-12 were tested for cantharidin retention rate, high-temperature stability, moisture absorption rate, dispersion uniformity, compressive strength, degree of substitution of composite modified starch wall material, oxygen permeability, free radical scavenging rate, microcapsule breakage rate, and gastrointestinal release rate. The test methods and standards are as follows:

[0127] 1. Cantharidin retention rate (accelerated oxidation test)

[0128] Referring to the standard GB / T 21512-2008 "Cantharidin as a Feed Additive", the samples were placed in a constant temperature and humidity chamber at 40℃ and 75% relative humidity for 30 days. The cantharidin content before and after the experiment was determined by high performance liquid chromatography (HPLC). Chromatographic conditions: C18 column (4.6 mm × 250 mm, 5 μm), mobile phase: methanol-acetonitrile (50:50 v / v), flow rate: 1.0 mL / min, detection wavelength: 470 nm, column temperature: 30℃. The retention rate was calculated as follows: Retention rate (%) = (Cantharidin content after experiment / Cantharidin content before experiment) × 100%.

[0129] 2. High-temperature stability (canthaxanthin retention rate)

[0130] The sample was placed in a 130℃ forced-air drying oven for 30 min, cooled to room temperature, and the cantharidin content was determined by the above HPLC method. The retention rate was calculated using the same formula.

[0131] 3. Moisture absorption rate

[0132] Referring to the "General Method for Determination of Moisture in Chemical Products" (GB / T 6284-2016), accurately weigh 5g of sample (accurate to 0.0001g), place it in a constant temperature and humidity chamber at 25℃ and 85% relative humidity for 7 days, and calculate the moisture absorption rate using the formula: Moisture absorption rate (%) = (sample mass after placement - sample mass before placement) / sample mass before placement × 100%.

[0133] 4. Dispersion uniformity (particle size distribution CV value)

[0134] Take 0.1g of sample and add it to 100mL of deionized water (containing 0.1wt% Tween 80). Stir at 500r / min for 10min and then use a laser particle size analyzer (Malvin Mastersizer 3000) to determine the particle size distribution and record the coefficient of variation (CV value). The smaller the CV value, the better the dispersion uniformity.

[0135] 5. Compressive strength

[0136] Using a particle strength tester, 20 microcapsule particles were randomly selected, and the compressive breaking force of each particle was measured. The average value was taken as the compressive strength.

[0137] 6. Determination of the degree of substitution (DS value) of composite modified starch wall materials

[0138] Referencing the titration method in "Food Additives - Sodium Octenyl Succinate Starch" (GB 28303-2012): Weigh 1.0 g (accurate to 0.0001 g) of the sample dried to constant weight (denoted as m), place it in a 250 mL Erlenmeyer flask, add 50 mL of anhydrous ethanol, shake for 10 min, filter, and wash the residue three times with anhydrous ethanol; transfer the residue to an Erlenmeyer flask, add 50 mL of deionized water, heat to dissolve, cool to room temperature, add 2 drops of phenolphthalein indicator, and titrate with 0.1 mol / L sodium hydroxide standard solution until pink (not fading for 30 s), and record the volume consumed, V (mL). Calculate the DS value using the following formula: DS = (0.162 × V × c) / (m - 0.210 × V × c). In the formula: c is the concentration of sodium hydroxide standard solution (mol / L); 0.162 is the molar mass of starch glucose unit (kg / mol); 0.210 is the molar mass of octenyl succinic anhydride (OSA) itself (kg / mol).

[0139] 7. Oxygen permeability measurement

[0140] Referring to the "Determination of Gas Permeability of Plastic Films and Sheets by Pressure Difference Method" (GB / T 1038-2000), a 50 μm thick pressed film (simulating the structure of microcapsule wall material) was made from composite modified starch wall material. The oxygen permeability was measured using a gas permeameter under the following conditions: temperature 23℃, relative humidity 50%, and pressure difference 0.1 MPa.

[0141] 8. Determination of free radical scavenging rate

[0142] Referring to the "Technical Specifications for Inspection and Evaluation of Health Foods" (2003 edition), a modified DPPH method was adopted: 0.1 g of sample was taken and added to 100 mL of deionized water (containing 0.2 wt% Tween 80), and ultrasonically dispersed for 15 min to prepare a 1 mg / mL sample dispersion; 0.1 mL of sample dispersion was taken and added to 3.9 mL of DPPH ethanol solution (concentration 0.1 mmol / L), and reacted in the dark for 30 min. The absorbance was measured at 517 nm, and the free radical scavenging rate was calculated: Scavenging rate (%) = [1 - (sample absorbance - blank absorbance) / control absorbance] × 100%. The blank group consisted of 0.1 mL of deionized water containing 0.2 wt% Tween 80 + 3.9 mL of DPPH ethanol solution.

[0143] 9. Determination of microcapsule breakage rate

[0144] Microscopic counting method: Take 1g of sample and disperse it evenly on a glass slide. Under an optical microscope (100x), randomly select 5 fields of view and count the total number of particles and the number of broken particles (particles with broken wall material and exposed core components). The formula for calculating the breakage rate is: Breakage rate (%) = (number of broken particles / total number of particles) × 100%.

[0145] 10. Gastrointestinal release rate determination

[0146] Referring to the Dissolution Test Method (Method II) of Part IV of the 2020 Edition of the Chinese Pharmacopoeia, the sample preparation was as follows: 0.5 g of microcapsule formulation was filled into enteric-coated capsules and placed in a dissolution apparatus; the gastrointestinal environment was simulated: first, the mixture was stirred at 50 r / min for 2 h in 900 mL of hydrochloric acid solution with pH 2.0 (simulating the gastric environment), then 200 mL of phosphate buffer solution with pH 8.0 was added to adjust the pH of the system to 7.0, and stirring was continued for 4 h (simulating the intestinal environment); the content of cantharidin released at different time points was determined by HPLC, and the cumulative release rate was calculated. The cumulative release rate is the reference value for intestinal absorption rate.

[0147] The results are shown in Tables 2 and 3.

[0148] Table 2 Performance parameters of the cantharidin microcapsule formulations obtained in Examples 1-3 and Comparative Examples 1-12

[0149] Group Cantharidin retention rate after accelerated oxidation (%) Cantharidin retention rate after high-temperature treatment (%) Free radical scavenging rate (%) Example 1 80.5 75.3 78.2 Example 2 84.8 78.7 81.5 Example 3 87.2 80.5 84.8 Comparative Example 1 68.2 62.8 65.5 Comparative Example 2 70.5 65.2 68.3 Comparative Example 3 83.6 77.1 82.3 Comparative Example 4 82.3 79.2 80.6 Comparative Example 5 78.1 73.5 79.8 Comparative Example 6 77.5 72.9 78.7 Comparative Example 7 73.6 68.3 77.2 Comparative Example 8 76.4 71.8 74.3 Comparative Example 9 72.9 66.6 72.5 Comparative Example 10 81.2 77.8 82.5 Comparative Example 11 80.6 76.5 81.8 Comparative Example 12 79.7 75.9 81.3

[0150] Table 3 Performance parameters of the cantharidin microcapsule formulations obtained in Examples 1-3 and Comparative Examples 1-12

[0151] Group Moisture absorption rate (%) Dispersion uniformity CV value (%) Compressive strength (N) <![CDATA[Oxygen permeability (cm 3 ·mm / (m 2 ·d·MPa))]]> Example 1 2.9 12.8 12.5 33.5 Example 2 2.3 10.5 15.3 29.6 Example 3 1.8 8.7 17.6 25.8 Comparative Example 1 3.6 15.2 13.8 52.2 Comparative Example 2 2.7 14.5 14.2 49.9 Comparative Example 3 3.2 9.1 11.5 27.5 Comparative Example 4 1.9 8.6 17.3 26.2 Comparative Example 5 2.0 18.3 16.9 28.7 Comparative Example 6 2.1 17.6 16.7 29.2 Comparative Example 7 3.0 10.8 12.3 38.8 Comparative Example 8 2.8 12.4 14.7 41.5 Comparative Example 9 2.2 13.1 15.9 31.2 Comparative Example 10 1.9 9.3 16.8 28.5 Comparative Example 11 2.0 9.0 14.3 30.1 Comparative Example 12 2.1 9.2 15.1 32.3

[0152] Using Example 3 as the control group, the performance differences and causes of Comparative Examples 1-12 are analyzed as follows:

[0153] Comparative Example 1: Ordinary octenyl succinate starch ester has a low DS value and lacks trehalose grafting, indicating a lack of esterification-grafting synergy, insufficient hydrogen bond network density, and an oxygen permeability of 25.8 cm⁻¹. 3 ·mm / (m 2 The pressure (d / MPa) rose to 52.2 cm. 3 ·mm / (m 2 The compressive strength of the wall material increased by 102.3% after high pressure homogenization (·d·MPa); the retention rate of cantharidin decreased from 87.2% to 68.2% after accelerated oxidation due to easy penetration of oxygen and moisture, a decrease of 21.8%; the wall material could not form a dense structure after high pressure homogenization, and the compressive strength decreased by 21.6%.

[0154] Comparative Example 2: Single tocopherol cannot form a synergistic eutectic system, and the free radical scavenging rate decreased from 84.8% to 68.3%, a decrease of 19.4%; lacking the dispersion stabilizing effect of the eutectic system, the dispersion uniformity CV value increased from 8.7% to 14.5%, an increase of 66.7%; insufficient antioxidant protection led to a decrease of 18.9% in the retention rate of canthaxanthin after high-temperature treatment.

[0155] Comparative Example 3: The hydrophobic modified silica lacked moisture resistance and reinforcing properties, with the moisture absorption rate increasing from 1.8% to 3.2%, a rise of 77.8%; the microcapsule structure lacked support, and the compressive strength decreased from 17.6N to 11.5N, a drop of 34.7%; this component mainly improved moisture resistance and structural support through physical filling, and had no significant effect on the hydrogen bond network structure and antioxidant synergistic effect, therefore the oxygen permeability and free radical scavenging rate did not change significantly.

[0156] Comparative Example 4: The synergistic antioxidant effect of tea polyphenols disappeared. After accelerated oxidation, the retention rate of cantharidin decreased by 5.6%, the free radical scavenging rate decreased by 4.9%, and other properties did not change significantly. The retention rate of cantharidin did not differ significantly, indicating that tea polyphenols mainly improve long-term storage stability through synergistic antioxidant effects and do not affect the stability maintenance mechanism of cantharidin under high-temperature processing.

[0157] Comparative Example 5: Using only sucrose fatty acid esters could not accurately match the HLB value of the oil phase, resulting in decreased emulsion stability and an increase in the dispersion uniformity CV value from 8.7% to 18.3%, a rise of 110.3%; excessively high local concentrations led to the oxidative polymerization of canthaxanthin, and the accelerated oxidation retention rate of canthaxanthin decreased by 10.4%; differences in emulsification uniformity did not significantly alter the microstructure of the wall material, and oxygen permeability did not change significantly.

[0158] Comparative Example 6: The single MCT has a high viscosity and no synergistic antioxidant effect of high oleic sunflower seed oil. The oil phase is easily oxidized, which leads to an 11.1% decrease in the retention rate of canthaxanthin after accelerated oxidation. The increased viscosity results in uneven particle size distribution after emulsification, and the dispersion uniformity CV value increases by 102.3%.

[0159] Comparative Example 7: Without high-pressure homogenization and refining treatment, the molecular chains of the wall material could not be tightly cross-linked, the hydrogen bond network density decreased, and the oxygen permeability decreased from 25.8 cm⁻¹. 3 ·mm / (m 2 The pressure (d / MPa) rose to 38.8 cm. 3 ·mm / (m 2 The wall material density was insufficient, leading to a 15.6% decrease in the accelerated oxidation retention rate and a 30.1% decrease in compressive strength. The moisture absorption rate increased from 1.8% to 3.0%, a rise of 66.7%, as insufficient wall material density resulted in easy water penetration.

[0160] Comparative Example 8: The composite modified starch wall material lacked trehalose grafting, resulting in a loss of esterification-grafting synergy, reduced hydrogen bond density, and increased oxygen permeability to 41.5 cm. 3 ·mm / (m 2 The compressive strength decreased by 60.9% (·d·MPa); insufficient antioxidant properties of the wall material led to a 12.4% decrease in accelerated oxidation retention rate and a 16.5% decrease in compressive strength.

[0161] Comparative Example 9: The imbalance between oryzanol and tocopherol resulted in insufficient co-crystal formation, decreased co-crystal structure integrity, weakened hydrophobic interactions and hydrogen bonding, and a decrease in free radical scavenging rate to 72.5%, a drop of 14.5%; the complex dispersibility deteriorated, leading to a 17.3% decrease in high-temperature retention rate.

[0162] Comparative Example 10: When the inlet air temperature of spray drying is too low, the residual moisture on the surface of the microcapsules increases. During high-temperature treatment, the moisture promotes the oxidation reaction, and the high-temperature retention rate decreases by 3.4%. Insufficient drying does not affect the hydrogen bond network, and the oxygen permeability does not change significantly.

[0163] Comparative Example 11: Insufficient high-pressure homogenization resulted in inadequate densification of the wall material, leading to an oxygen permeability of 30.1 cm⁻¹. 3 ·mm / (m 2 The compressive strength of the wall material was 16.7% higher than that of the wall material (·d·MPa), while the mechanical strength of the wall material was insufficient, resulting in a 18.8% decrease in compressive strength.

[0164] Comparative Example 12: Insufficient nitrogen protection pressure caused a slight oxidation reaction in the oil phase during the preparation process, resulting in an 8.6% decrease in the retention rate of cantharidin after accelerated oxidation; oxidation did not affect the wall material structure and there was no significant change in physical properties.

[0165] In summary, the composite modified starch wall material can encapsulate and isolate the internal components of the formulation, reducing the impact of the external environment on the active ingredients; the oryzanol-tocopherol complex and cantharidin synergistically exert antioxidant effects, enhancing the overall free radical scavenging ability of the formulation; the dispersion medium promotes uniform dispersion of each component in the system, while the emulsifying stabilizer maintains the stability of the formulation system, preventing stratification or precipitation; maltodextrin assists in formulation shaping and improves the physical stability of the formulation; hydrophobically modified silica reduces the hygroscopicity of the formulation, improving its storage stability; and tea polyphenols further enhance the antioxidant effect of the formulation. The synergistic effect of these components gives the formulation excellent antioxidant properties, along with good dispersion uniformity and storage stability, effectively improving the antioxidant capacity of feed.

[0166] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cantharidin microcapsule formulation for improving the antioxidant properties of feed, characterized in that, The raw materials for its preparation, by weight, include: 0.5-2.0 parts of cantharidin, 25-35 parts of composite modified starch wall material, 3-8 parts of oryzanol-tocopherol complex, 10-18 parts of dispersion medium, 28-38 parts of maltodextrin, 1.5-4.0 parts of hydrophobic modified silica, 1.8-4.5 parts of emulsifying stabilizer, and 0.3-0.8 parts of tea polyphenols.

2. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 1, characterized in that, The raw materials for preparing the composite modified starch wall material, by weight, include: 95-105 parts starch, 300-450 parts deionized water, 3-5 parts octenyl succinic anhydride, 10-15 parts trehalose, 1-2 parts citric acid, and 0.5-1.0 parts initiator; wherein the starch is either glutinous corn starch or potato starch, and the initiator is either ammonium persulfate or azobisisobutyronitrile.

3. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 2, characterized in that, The preparation method of composite modified starch wall material includes the following steps: 1) Add starch to deionized water, stir evenly at 200-400 r / min, heat to 75-85℃, gelatinize for 25-35 min, cool to 35-45℃, and adjust the pH of the system to 7.0-8.0; 2) Under constant temperature of 35-45℃ and stirring at 300-500r / min, slowly add octenyl succinic anhydride to the system obtained in step 1), controlling the addition time to be 30-60min. After the addition is completed, continue to react under the above conditions for 2-4h, and maintain the pH of the system at 7.0-8.0 during this period. 3) Add trehalose, citric acid and initiator to the system obtained in step 2), heat to 50-60℃ and keep warm, stir at 300-400r / min for 3-5h to form octenyl succinate-trehalose grafted modified starch. 4) Adjust the pH of the octenyl succinate-trehalose grafted modified starch system to 6.5-7.0, concentrate it under reduced pressure to a solid content of 30-40% under vacuum conditions of -0.06~-0.09MPa and 45-55℃, and then spray dry it. After drying, the product is pulverized and passed through a 100-120 mesh sieve to obtain the composite modified starch wall material.

4. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 3, characterized in that, In step 4), the spray drying conditions are: inlet air temperature 170-190℃, outlet air temperature 80-90℃, atomization pressure 0.3-0.5MPa, and feed rate 10-15mL / min.

5. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 1, characterized in that, The raw materials for preparing the oryzanol-tocopherol complex, by weight, include: 30-50 parts of oryzanol, 30-60 parts of tocopherol, 100-150 parts of anhydrous ethanol, and 3-8 parts of auxiliary molding agent. The auxiliary molding agent is one of glyceryl monostearate, beeswax, or stearic acid, and the tocopherol is one of α-tocopherol, γ-tocopherol, or tocopherol acetate.

6. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 5, characterized in that, The preparation method of the oryzanol-tocopherol complex includes the following steps: (1) Add oryzanol, tocopherol and auxiliary forming agent to anhydrous ethanol and treat for 20-30 min at 60-70℃ and 400-600r / min stirring to form a uniform and stable dispersion system; (2) The dispersion system obtained in step (1) is maintained at 60-70℃ and 300-400r / min, and then anhydrous ethanol is recovered by vacuum distillation under vacuum conditions of -0.08~-0.10MPa to form a eutectic solid precursor; (3) The eutectic solid precursor was vacuum dried at 50-60℃ and vacuum degree -0.08~-0.10MPa for 2-4h to remove residual ethanol, and then pulverized and passed through a 90-110 mesh sieve to obtain oryzanol-tocopherol complex.

7. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 1, characterized in that, The dispersion medium is a mixture of medium-chain triglycerides (MCT) and high-oleic sunflower seed oil in a mass ratio of 2:1 to 1:

1.

8. The cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 1, characterized in that, The emulsifying stabilizer is a compound of sucrose fatty acid ester and lecithin in a mass ratio of 0.5:1 to 1.5:

1.

9. A method for preparing a cantharidin microcapsule formulation for improving the antioxidant properties of feed according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Oil phase preparation: Under nitrogen micro-positive pressure protection, add dispersion medium to the reaction vessel, heat to 60-80℃, add cantharidin and oryzanol-tocopherol complex, stir at 500-800r / min for 20-40min to form a uniform oil phase; S2. Aqueous phase preparation: Add deionized water to another reactor, the amount of which is 3-5 times the weight of the composite modified starch wall material. Heat to 40-55℃, add the composite modified starch wall material, maltodextrin, hydrophobic modified silica, emulsifying stabilizer and tea polyphenols, and stir at 300-500 r / min for 30-50 min to form a uniform and stable aqueous phase system. S3. Emulsification treatment: Under nitrogen protection, the oil phase is slowly added dropwise to the aqueous phase at a rate of 5-10 mL / min. After the addition is complete, the high-speed shear emulsifier is turned on and emulsified at a speed of 8000-12000 r / min for 15-30 min to form an O / W type emulsion. S4. High-pressure homogenization and refining treatment: The emulsion is fed into a high-pressure homogenizer, and the pressure is controlled at 30-50MPa, the temperature at 40-50℃, and the homogenization is carried out 1-2 times to refine the average particle size of the emulsion to 3-8μm. S5. Spray drying and molding: The emulsion processed in step S4 is fed into a spray dryer, and the inlet air temperature is controlled at 180-200℃, the outlet air temperature at 85-95℃, the feed rate at 10-20mL / min, and the atomization pressure at 0.2-0.4MPa. After drying, it is passed through a 50-70 mesh sieve, sealed and stored to obtain the cantharides microcapsule preparation.

10. The method for preparing the cantharidin microcapsule formulation for improving the antioxidant properties of feed according to claim 9, characterized in that, In step S1, the nitrogen micro-positive pressure protection is controlled by a pressure transmitter and an automatic regulating valve to maintain the gauge pressure at 0.01-0.03 MPa; in step S4, the throughput of the high-pressure homogenization and refining treatment is 100-200 L / h.