Antioxidant feed additive composition and application thereof in broiler chicken breeding

Abstract

The invention relates to the technical field of chemical feed additive manufacturing, and discloses an antioxidant feed additive composition and application thereof in broiler chicken breeding, the composition comprises a precipitated silica carrier and a ternary eutectic solvent active system adsorbed on the precipitated silica carrier; the active system is a homogeneous fluid formed by carrying out a thermally induced in-situ coordination reaction on anhydrous betaine, alpha-lipoic acid and organic zinc salt at 75-85 DEG C, and the molar ratio of the components forming the active system is (1.5-2.5): 1: (0.05-0.2). According to the preparation method, a metal coordination supramolecular network is constructed, and the catalytic oxidation activity of zinc ions is effectively passivated by utilizing dual effects of coordination bonds and hydrogen bonds, so that the processing thermal stability of alpha-lipoic acid and the moisture absorption resistance of anhydrous betaine are improved. The composition has a pH response type intelligent release characteristic, and can effectively relieve oxidative stress and improve meat quality when applied to broiler chicken breeding.

Description

Technical Field

[0001] This invention relates to the field of chemical feed additive manufacturing technology, specifically to antioxidant feed additive compositions and their application in broiler farming. Background Technology

[0002] With the widespread adoption of intensive livestock and poultry farming, oxidative stress has become a key factor affecting animal growth performance and meat quality. Therefore, adding highly effective antioxidants to feed has become an industry consensus. Among them, alpha-lipoic acid, due to its combination of fat and water solubility and its ability to regenerate other antioxidants (such as vitamins C and E), is hailed as a universal antioxidant. Anhydrous betaine, as an excellent methyl donor and osmotic pressure regulator, also plays an important role in alleviating heat stress in animals. Theoretically, combining these two can produce a significant synergistic effect.

[0003] However, in practical industrial applications, the inherent physicochemical defects of these two substances limit their compounding effects and processing stability. α-Lipoic acid contains a highly strained disulfide five-membered ring structure, resulting in a low melting point (approximately 60℃-62℃) and extreme sensitivity to light and heat. Under the high-temperature and high-humidity conditions of feed pelleting (typically above 80℃), α-lipoic acid readily undergoes ring-opening polymerization or oxidative decomposition, leading to loss of activity. Simultaneously, anhydrous betaine is highly hygroscopic, readily absorbing moisture and deliquescing upon exposure to air, causing clumping and reduced flowability in the finished feed additive, severely affecting the accuracy of measurement and storage stability. Furthermore, α-lipoic acid is lipid-soluble, while anhydrous betaine is strongly water-soluble; their polarity differences are significant, making simple physical mixing difficult to achieve uniform dispersion and failing to improve their respective stability defects.

[0004] A more challenging aspect is that, to meet the micronutrient requirements for animal growth, feed formulations typically require the addition of transition metal elements such as zinc. However, in traditional chemistry, transition metal ions are considered potent oxidation catalysts, readily inducing Fenton-like reactions and accelerating the oxidative degradation of antioxidants. Therefore, current technologies often avoid direct contact between metal salts and oxidation-sensitive organic components, or employ complex coating techniques to physically isolate them. This not only increases processing costs but also fails to address the fundamental issue of metal ion-induced oxidation at the molecular level, and further fails to utilize metal ions to achieve stable regulation of organic molecular structures.

[0005] Therefore, there is an urgent need to develop a novel technical solution that can simultaneously overcome the heat sensitivity of α-lipoic acid, the hygroscopicity of betaine, and the oxidative activity of metal ions. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an antioxidant feed additive composition and its application in broiler farming, solving the problems of poor thermal stability of α-lipoic acid, easy moisture absorption and clumping of anhydrous betaine, and easy catalysis of antioxidant oxidation and inactivation by transition metal ions in existing technologies.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides an antioxidant feed additive composition.

[0008] This composition is a supported ternary system constructed using supramolecular chemical assembly technology. Instead of employing traditional physical mixing or microencapsulation methods, it constructs a ternary eutectic solvent active system adsorbed within a porous structure of precipitated silica.

[0009] In the microstructure construction of this active system, this invention utilizes anhydrous betaine as a hydrogen bond acceptor (HBA), α-lipoic acid as a hydrogen bond donor (HBD), and introduces a specific ratio of organic zinc salts as coordination crosslinking centers. Unlike the simple dispersion of solute and solvent in conventional solutions, this ternary system achieves this by disrupting the original crystal lattice structure of each component and re-establishing hydrogen bond and coordination bond networks between molecules.

[0010] Specifically, this invention utilizes zinc ions (Zn 2+ The empty orbital of the metal forms a stable coordination structure with the carboxyl / quaternary ammonium group of anhydrous betaine and the carboxyl group of α-lipoic acid. This in-situ introduced metal coordination bond plays a dual role in the system: First, the lattice energy regulation effect: The intervention of zinc ions reduces the free energy of the eutectic point of the binary system, which allows the originally high-melting-point anhydrous betaine and low-melting-point lipoic acid to spontaneously transform into thermodynamically stable homogeneous fluids at a relatively mild temperature (75℃-85℃), realizing the transformation from crystalline to amorphous glassy material.

[0011] Second, electron cloud density locking effect: through the formation of the ligand field, the electron cloud density of the active disulfide bond in α-lipoic acid is restrained, thereby increasing its energy barrier against thermal decomposition and photo-oxidation; at the same time, zinc ions are tightly wrapped by organic ligands, and their own catalytic active sites are shielded, thereby achieving chemical passivation of metal ions and avoiding their pro-oxidation effect on organic components.

[0012] Regarding the component ratio, to ensure the integrity of the supramolecular network and avoid the precipitation of free crystals, the molar ratio of each component forming the ternary eutectic solvent active system is strictly limited to: anhydrous betaine: α-lipoic acid: zinc ions = (1.5-2.5):1:(0.05-0.2). This ratio range ensures the site matching degree between hydrogen bond acceptors and donors, as well as the coordination saturation of metal ions.

[0013] The active system was ultimately adsorbed onto the precipitated silica support at a mass ratio of 1:(0.8-1.5). The precipitated silica has a high specific surface area (150-200 m²). 2 The high oil absorption value (2.0-3.5 mL / g) provides physical support for the liquid supramolecular fluid, allowing it to exist in solid powder form. Furthermore, the pore confinement effect further restricts the thermal motion of molecules, enhancing stability.

[0014] The preparation method of the antioxidant feed additive composition is designed based on the principle of thermally induced phase transition coupled in-situ coordination, and the specific steps include: Solid-phase dispersion (physical mixing): Anhydrous betaine, α-lipoic acid and organozinc salt are premixed in the solid state to ensure uniform contact of the reaction precursors at the microscale, providing the maximum contact area for subsequent reactions.

[0015] Phase transition and coordination reaction (thermally induced eutectic): The system is heated to 75℃-85℃. This temperature range is precisely designed, higher than the melting point of α-lipoic acid but much lower than that of anhydrous betaine. Under these conditions, molten α-lipoic acid molecules, acting as solvent precursors, attack the anhydrous betaine lattice, while zinc ions participate in the reaction. Hydrogen bond recombination and coordination bonding are completed through continuous renewal of the solid-liquid interface. This process continues until all diffraction peaks in the system disappear, transforming it into a long-range disordered homogeneous fluid. This step must be carried out under an inert atmosphere (such as a nitrogen flow) to prevent oxidation risks during the phase transition.

[0016] Solidification and molding (fluidized bed adsorption): Using a fluidized bed process, a ternary fluid in a low-viscosity state (65℃-70℃) is atomized and dispersed onto the surface of a low-temperature carrier. Utilizing the rapid cooling effect of the temperature difference, the supramolecular fluid rapidly transforms from a liquid state to a high-viscosity glassy or semi-solid state within the carrier pores, thus locking in its physical form.

[0017] Structural relaxation (aging): Aging is carried out in a closed environment to eliminate the internal stress generated by rapid cooling, so that the supramolecular network structure reaches a thermodynamic equilibrium state.

[0018] A second aspect of the invention provides the application of the aforementioned antioxidant feed additive composition in broiler farming. This application is based on the composition's unique environmentally responsive dissociation mechanism. During feed processing, storage, and animal consumption (neutral or weakly acidic environments), the ternary coordination supramolecular structure remains intact, effectively isolating oxygen and moisture, protecting α-lipoic acid from degradation, and shielding the hygroscopic sites of betaine. When the composition enters the broiler gizzard (a strongly acidic environment with a pH of 2.0-3.0), a high concentration of protons (H+)... + The zinc-carboxyl group competitively binds to the alpha-lipoic acid, leading to the breakage of the zinc-carboxyl coordination bond and the disintegration of the hydrogen bond network. This dissociation triggers the release of the active ingredient, allowing alpha-lipoic acid to be released in a microemulsion form and absorbed by the body in synergistic with betaine and zinc ions. This application is mainly used to alleviate oxidative stress in broilers by enhancing the activity of endogenous antioxidant enzymes (such as GSH-Px) and protecting the integrity of cell membrane structures, thereby reducing muscle dripping loss and improving meat quality.

[0019] This invention provides an antioxidant feed additive composition and its application in broiler farming. It has the following beneficial effects: 1. This invention constructs a ternary supramolecular eutectic system of anhydrous betaine, α-lipoic acid, and zinc ions. By utilizing the dual cross-linking effect of metal coordination bonds and hydrogen bonds, the lattice energy and molecular motion state of the raw materials are changed, effectively restricting the thermal motion of α-lipoic acid molecules under high-temperature conditions and preventing thermal polymerization or oxidative decomposition during feed pelleting. On the other hand, zinc ions competitively occupy the nucleophilic sites in the anhydrous betaine molecules with lipoic acid, significantly reducing the surface energy and hygroscopicity of betaine, thus solving the process problem of traditional formulations being prone to deliquescence and clumping in humid environments.

[0020] 2. This invention overcomes the technical bias of avoiding the direct addition of transition metal ions in antioxidant formulations. By utilizing the unique dielectric environment and coordination field effect of eutectic solvents, in-situ passivation of metal ions is achieved. By coordinating and locking the empty orbitals of zinc ions with electron-rich groups (such as carboxyl groups) of organic components, the potential catalytic active sites of metal ions are shielded, effectively blocking Fenton-like pro-oxidation reactions induced by metal ions. This not only avoids the destruction of α-lipoic acid by metal ions, but also enhances the stability of the system by using metal ions as structural anchors, achieving a synergistic unity of trace element supplementation and antioxidant enhancement.

[0021] 3. The ternary coordination supramolecular complex prepared in this invention possesses a specific environmental response mechanism. Under feed storage and neutral conditions, the coordination structure remains thermodynamically stable, ensuring that the active ingredient is not oxidized by the external environment. When it enters the highly acidic environment (pH 2.0-3.0) of the broiler's gizzard, a high concentration of protons competitively displaces the metal ions in the coordination bonds, triggering rapid disintegration of the supramolecular network. Furthermore, the disintegrated α-lipoic acid is dispersed in the digestive fluid in a submicron-sized emulsion form. Utilizing the osmotic pressure regulation effect of betaine, it overcomes the shortcomings of low solubility and poor absorption of lipid-soluble antioxidants in aqueous environments, thereby improving the bioavailability of the active ingredient at the target site. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0023] raw material: Anhydrous betaine, CAS number 107-43-7, relative molecular mass 117.15; DL-α-lipoic acid, CAS number 1077-28-7, has a relative molecular mass of 206.33; Zinc citrate, CAS number 546-46-3, relative molecular mass 574.37; Anhydrous zinc acetate, CAS number 557-34-6, relative molecular mass 183.48; Betaine hydrochloride, CAS number 590-46-5, relative molecular mass 153.61; Zinc sulfate heptahydrate, CAS number 7446-20-0, has a relative molecular mass of 287.56.

[0024] Preparation Example 1: Unless otherwise stated, the antioxidant feed additive compositions in the subsequent examples and comparative examples were prepared according to the following general steps: Step S1: Accurately weigh anhydrous betaine, α-lipoic acid, and organozinc salt according to the molar ratios set in each embodiment. Place the above three solid powders in a high-speed mixer and dry mix for 5-10 minutes at room temperature (20℃-25℃) and a speed of 800-1000 rpm until a macroscopically uniform mixed powder with no color difference is obtained by visual inspection.

[0025] Step S2: Transfer the mixed powder obtained in Step S1 to a reactor equipped with mechanical stirring, temperature monitoring, and reflux devices. Pour a stream of dry nitrogen at a flow rate of 100-200 mL / min into the reactor to displace the air inside. Turn on the oil bath heating and heat the material to the specified reaction temperature (between 75℃ and 85℃, see specific examples) at a heating rate of 2-5℃ / min, while simultaneously turning on the mechanical stirring (150-300 rpm). Maintain the reaction under these temperature and stirring conditions for 40-60 minutes, until the solid powder in the reactor completely disappears and the material transforms into a clear, transparent, and homogeneous pale yellow to golden yellow viscous fluid. Stop heating at this point.

[0026] Step S3: Cool the fluid obtained in Step S2 and maintain it at 65℃-70℃, then transport it to a pressure atomizing nozzle via a thermal pump system. Simultaneously, add the precipitated silica carrier (calculated by mass ratio) to a fluidized bed granulator, turn on the fluidizing fan, and control the inlet air temperature between 25℃-35℃ to maintain the carrier in a stable fluidized suspension state. Start the atomizing nozzle and uniformly spray the ternary eutectic solvent active system onto the fluidized carrier surface. Control the spraying rate to prevent carrier collapse and agglomeration until all liquid is sprayed. After spraying, continue to maintain the fluidized state for 10-15 minutes to promote fluid penetration into the carrier pores and initial cooling.

[0027] Step S4: Discharge the powder adsorbed in step S3 from the fluidized bed and cool it to room temperature. Place the powder into a sealed container with a moisture-proof liner and allow it to stand and age at 20℃-25℃ for 12-24 hours to allow the supramolecular network structure to complete thermodynamic relaxation and rearrangement, thus obtaining the finished antioxidant feed additive composition.

[0028] Examples 1-6: Example 1: This embodiment provides an antioxidant feed additive composition in which the molar ratio of each component in the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 2:1:0.1, zinc citrate is selected as the organic zinc salt, and the mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:1. The composition includes the following preparation steps: Step S1: Accurately weigh anhydrous betaine, α-lipoic acid and zinc citrate according to the above molar ratio, and mix them evenly in a high-speed mixer to obtain a mixed powder.

[0029] Step S2: Place the mixed powder in a reaction vessel, and heat it to 80°C under nitrogen gas protection and stirring at 200 rpm; continue the reaction at this temperature for 45 minutes until the solid powder completely disappears and a clear, transparent, golden-yellow homogeneous fluid is formed.

[0030] Step S3: Cool the obtained fluid and maintain it at 68°C. Spray it evenly through an atomizing nozzle onto the precipitated silica carrier in a fluidized state with air inlet at 30°C. Control the spraying amount so that the final mass ratio of the active system to the carrier is 1:1. Continue fluidization for 10 minutes after spraying.

[0031] Step S4: Discharge the adsorbed powder, cool it to room temperature, and let it stand and age in a sealed container for 24 hours to obtain an antioxidant feed additive composition.

[0032] Example 2: This embodiment provides an antioxidant feed additive composition, wherein the molar ratio of each component in the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 2.5:1:0.05, zinc citrate is selected as the organic zinc salt, and the mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:1.2. The composition includes the following preparation steps: Step S1: Accurately weigh the raw materials according to the above molar ratio, and mix them evenly to obtain a mixed powder.

[0033] Step S2: Place the mixed powder in a reaction vessel, and heat it to 85°C under nitrogen gas protection and stirring at 300 rpm; continue the reaction at this temperature for 40 minutes until the system is completely converted into a clear homogeneous fluid.

[0034] Step S3: Maintain the obtained fluid at 70°C and spray it onto the precipitated silica carrier in a fluidized state at 35°C until the mass ratio of the active system to the carrier reaches 1:1.2.

[0035] Step S4: Cool the adsorbed powder and age it under sealed conditions for 12 hours to obtain an antioxidant feed additive composition.

[0036] Example 3: This embodiment provides an antioxidant feed additive composition in which the molar ratio of each component in the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 1.5:1:0.2, zinc citrate is selected as the organic zinc salt, and the mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:0.8. The composition includes the following preparation steps: Step S1: Accurately weigh the raw materials according to the above molar ratio, and mix them evenly to obtain a mixed powder.

[0037] Step S2: Place the mixed powder in a reaction vessel, and heat it to 75°C under nitrogen gas protection and stirring at 150 rpm; continue the reaction at this temperature for 60 minutes to ensure that the high proportion of metal ions fully complete the coordination reaction and form a homogeneous fluid.

[0038] Step S3: Maintain the obtained fluid at 65°C and spray it onto the precipitated silica carrier in a fluidized state at 25°C, controlling the mass ratio of the active system to the carrier to be 1:0.8.

[0039] Step S4: Cool the adsorbed powder and age it under sealed conditions for 18 hours to obtain an antioxidant feed additive composition.

[0040] Example 4: This embodiment provides an antioxidant feed additive composition in which the molar ratio of each component in the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 2:1:0.1, anhydrous zinc acetate is selected as the organic zinc salt, and the mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:1. The composition includes the following preparation steps: Step S1: Accurately weigh anhydrous betaine, α-lipoic acid and anhydrous zinc acetate according to the above molar ratio, and mix them evenly to obtain a mixed powder.

[0041] Step S2: Place the mixed powder in a reaction vessel and heat it to 80°C under nitrogen protection; stir the reaction for 50 minutes until a clear and transparent homogeneous fluid is formed.

[0042] Step S3: Maintain the obtained fluid at 68°C and spray it onto the precipitated silica carrier in a fluidized state at 30°C, so that the mass ratio of the active system to the carrier is 1:1.

[0043] Step S4: Cool the adsorbed powder and age it under sealed conditions for 24 hours to obtain an antioxidant feed additive composition.

[0044] Example 5: This embodiment provides an antioxidant feed additive composition, wherein the molar ratio of each component in the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 2:1:0.15, zinc citrate is selected as the organic zinc salt, and the mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:1.5. The composition includes the following preparation steps: Step S1: Accurately weigh the raw materials according to the above molar ratio, and mix them evenly to obtain a mixed powder.

[0045] Step S2: Heat the mixed powder to 82°C in the reactor; stir the reaction for 45 minutes until a homogeneous fluid is obtained.

[0046] Step S3: Maintain the obtained fluid at 70°C and spray it onto the precipitated silica carrier in a fluidized state at 32°C; increase the amount of carrier until the mass ratio of the active system to the carrier reaches 1:1.5.

[0047] Step S4: Cool the adsorbed powder and age it under sealed conditions for 20 hours to obtain an antioxidant feed additive composition.

[0048] Example 6: This embodiment provides an antioxidant feed additive composition, wherein the molar ratio of each component in the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 1.8:1:0.1, zinc citrate is selected as the organic zinc salt, and the mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:1.1. The composition includes the following preparation steps: Step S1: Accurately weigh the raw materials according to the above molar ratio, and mix them evenly to obtain a mixed powder.

[0049] Step S2: Heat the mixed powder to 78°C in the reactor; stir the reaction for 55 minutes until a homogeneous fluid is obtained.

[0050] Step S3: Maintain the obtained fluid at 66°C and spray it onto the precipitated silica carrier in a fluidized state at 28°C, so that the mass ratio of the active system to the carrier is 1:1.1.

[0051] Step S4: Cool the adsorbed powder and age it under sealed conditions for 24 hours to obtain an antioxidant feed additive composition.

[0052] Comparative Examples 1-5: Comparative Example 1: This comparative example provides a physical mixture. The difference from Example 1 is that the thermally induced eutectic reaction in step S2 is not performed. Specifically, the weighed anhydrous betaine, α-lipoic acid, and zinc citrate are physically mixed uniformly at room temperature, and then directly mixed with the precipitated silica support.

[0053] Comparative Example 2: This comparative example provides a binary eutectic solvent system. The difference from Example 1 is that zinc citrate was not added to the raw materials. In the preparation process, only anhydrous betaine and α-lipoic acid were mixed at a 2:1 molar ratio and reacted at 80°C to form a binary eutectic solvent; all other steps and parameters were the same.

[0054] Comparative Example 3: This comparative example provides a common mixture containing an inorganic zinc source (simulating a traditional feed formulation). The difference from Example 1 is that zinc sulfate heptahydrate is used instead of zinc citrate, and the preparation process employs room-temperature physical mixing (i.e., the thermal reaction in step S2 is omitted). Anhydrous betaine, α-lipoic acid, and zinc sulfate heptahydrate powder are mixed evenly and then directly adsorbed onto the carrier.

[0055] Comparative Example 4: This comparative example provides a composition prepared by solvent evaporation. The difference from Example 1 is that the preparation process is changed to solvent dissolution and spray drying. Specifically, anhydrous betaine, α-lipoic acid, and zinc citrate are dissolved in anhydrous ethanol to form a solution, which is then sprayed onto a carrier. Finally, the ethanol solvent is removed by hot air drying, while the remaining proportions remain the same.

[0056] Comparative Example 5: This comparative example provides a composition using different hydrogen bond acceptors. The difference from Example 1 is that betaine hydrochloride is used instead of anhydrous betaine. All other proportions and preparation steps (including the heating step) are the same.

[0057] Test Example 1-2: Test Example 1: Physicochemical Property Characterization and Process Feasibility Verification This test case aims to verify whether the compositions prepared in each example form the expected supramolecular eutectic structure and to evaluate their physical stability in industrial applications.

[0058] Experimental methods: Differential scanning calorimetry: The thermal phase state of the sample was analyzed using a differential scanning calorimeter (model: Mettler Toledo DSC3).

[0059] Procedure: Accurately weigh 5-10 mg of the powder sample to be tested, place it in an alumina crucible, and seal it with a pressure cap. Use an empty crucible as a reference. Under a protective atmosphere of high-purity nitrogen at a flow rate of 50 mL / min, Set the heating program: starting temperature -50℃, heating to 150℃ at a rate of 10℃ / min.

[0060] Observation indicators: Record the heat flow curves, focusing on whether the characteristic endothermic peaks of the raw materials α-lipoic acid (about 60-62℃) and anhydrous betaine (about 293℃; note: this test range mainly focuses on the melting zone and eutectic formation zone of lipoic acid, so the main characteristics can be observed up to 150℃) exist, and whether a new glass transition temperature (Tg) appears.

[0061] Angle of repose determination: The angle of repose of the powder sample was determined using the fixed funnel method to characterize the flowability of the powder.

[0062] Operating steps: Fix the funnel above the horizontally placed graph paper, with the lower opening of the funnel at a height of [height missing] from the graph paper. The initial diameter is set at 4.0 cm. Carefully and slowly add the sample to the funnel until the top of the resulting cone-shaped accumulation touches the bottom of the funnel. Measure the diameter of the cone's base. .

[0063] Calculation formula: The calculated angle This is the angle of repose. Each sample was measured in triplicate, and the average value was taken.

[0064] Moisture absorption and weight gain test: Simulate a high humidity environment to evaluate the moisture resistance of the sample.

[0065] Operating procedures: Accurately weigh m0 (approximately 2.0000g) of sample into a pre-weighed weighing bottle, and place it open in a constant temperature and humidity chamber. Set the environmental conditions as follows: temperature 30±1℃, relative humidity (RH) 75±2%. After 24 hours, remove the bottle, quickly tighten the cap, and weigh m1.

[0066] Calculation formula: Moisture absorption weight gain rate (%) = (m1-m0) / m0 × 100%.

[0067] Experimental results: Examples 1-3 (different ratios and zinc contents), Comparative Example 1 (physical mixing), Comparative Example 2 (zinc-free binary system), and Comparative Example 5 (betaine hydrochloride system) were selected for testing. The data are summarized in Table 1.

[0068] Table 1. Summary of test data on the thermal phase characteristics and physical stability of the composition

[0069] Conclusion Analysis: In Examples 1-3, the characteristic melting peak of the raw material α-lipoic acid completely disappeared, transforming into an amorphous state. This confirms that during the preparation process, the lattice energy barrier of the raw material was broken through thermal induction and zinc ion coordination, and anhydrous betaine, lipoic acid, and zinc ions formed a uniform ternary eutectic fluid (NADES) at the molecular scale. In contrast, Comparative Example 1 (physical mixing) and Comparative Example 5 (using betaine hydrochloride) both retained obvious crystalline melting peaks. This indicates that physical mixing alone cannot change the phase state of a substance; and because the carboxyl groups of betaine hydrochloride are protonated and blocked, it cannot act as a hydrogen bond acceptor to construct a eutectic network with lipoic acid, resulting in a phase-separated state of the system.

[0070] Anhydrous betaine raw material has extremely strong hygroscopic properties (typically a 24-hour weight gain >15%). The hygroscopic weight gain rates of Examples 1-3 (3.25-5.87%) were lower than those of Comparative Example 1 (18.93%). Comparing Example 1 (containing zinc) with Comparative Example 2 (without zinc, weight gain 9.41%), it can be seen that the introduction of zinc ions plays a crucial role in water retention. The mechanism lies in the coordination crosslinking between zinc ions and the carboxyl / quaternary ammonium groups of anhydrous betaine, occupying the binding sites of water molecules and increasing the intermolecular packing density, thereby preventing the intrusion of environmental moisture.

[0071] The angles of repose of the sample samples in the examples were all less than 35°, falling within the range of powders with excellent flowability. This is because the liquid NADES system was confined within the mesopores of precipitated silica, and the surface tension was suitable, preventing the formation of a viscous liquid film on the carrier surface. Comparative Examples 1 and 5, due to the presence of free hygroscopic betaine and low-melting-point lipoic acid, resulted in powder adhesion, with angles of repose exceeding 40°, poor flowability, and unfavorable conditions for accurate metering in feed processing.

[0072] Test Example 2: Chemical Stability Evaluation and Verification of Application Effects in Broiler Farming This test case aims to comprehensively evaluate the tolerance, release characteristics in the digestive tract environment, and actual biological efficacy of each embodiment and comparative sample under feed processing conditions through in vitro simulation experiments and in vivo animal experiments.

[0073] Experimental methods: Heat-resistant processing simulation experiment: Simulate the high-temperature environment during feed pelleting process to investigate the heat retention rate of the active ingredient α-lipoic acid.

[0074] Procedure: Weigh 1.0 g of the sample to be tested and spread it evenly in a petri dish. Place it in a precision forced-air drying oven and heat it open at 90±2℃ for 15 minutes (simulating granulation conditioning temperature and time). After cooling, extract the sample with methanol using ultrasound, filter it through a 0.45 μm filter membrane, and determine the content of α-lipoic acid in the sample using high performance liquid chromatography (HPLC).

[0075] Calculation formula: Heat retention rate (%) = (content after heating / initial content before heating) × 100%.

[0076] pH-responsive in vitro release experiment: to investigate the release behavior of the sample under different pH conditions and to verify its targeted release mechanism.

[0077] Operating procedures: Use an intelligent drug dissolution apparatus, set the rotation speed to 100 rpm, and the medium temperature to 37±0.5℃.

[0078] Medium A (simulating feed / oral environment): phosphate buffer solution at pH 6.8.

[0079] Medium B (simulating the gizzard environment): hydrochloric acid solution at pH 2.0. Equal volumes of sample were added, and 5 mL of sample was taken after 30 minutes. The sample was immediately filtered, and the concentration of α-lipoic acid in the released solution was determined by HPLC. The cumulative release rate was calculated.

[0080] Broiler feeding trial: Experimental design: 240 healthy 1-day-old white-feathered broilers with similar weights (45±2g) were randomly divided into 4 groups, with 6 replicates in each group and 10 birds in each replicate.

[0081] Blank control group: fed a corn-soybean meal basal diet.

[0082] Example 1 group: 500 mg / kg of Example 1 sample was added to the basal diet.

[0083] Comparative Example 1 (physical mixing): Add an equal amount of Comparative Example 1 sample.

[0084] Comparative Example 3 (physical mixture of inorganic zinc): An equal amount of Comparative Example 3 sample was added. Feeding and management: The experimental period was 42 days, with free access to feed and water. Measurement indicators: Serum antioxidant indicators: On day 42 of the experiment, blood was collected from the hearts of two broiler chickens in each replicate, serum was separated, and glutathione peroxidase (GSH-Px) activity was measured using a test kit.

[0085] Muscle drip loss: After slaughter, take a sample of the left pectoral muscle, trim it into a long strip, hang it in a sealed bag, and place it in a refrigerator at 4°C for 24 hours. Calculate the percentage of juice seepage.

[0086] Experimental results: The experimental data are summarized in Table 2 below. The data are the average values ​​of multiple measurements.

[0087] Table 2. Results of chemical stability and broiler biological indicators in different treatment groups

[0088] Conclusion Analysis: In the high-temperature test simulating granulation, the α-lipoic acid retention rates of Examples 1-3 were all above 92%, while that of Comparative Example 1 (physical mixing) was only 65.4%. This confirms that the coordination bonds in the ternary eutectic system effectively bind the α-lipoic acid molecules, inhibiting their thermal polymerization and volatilization after lattice collapse. Comparative Example 3 had the lowest retention rate (52.9%), indicating that free inorganic zinc ions do indeed accelerate the oxidative decomposition of lipoic acid at high temperatures (Fenton-like effect), while the examples passivated the zinc ions through organic coordination, eliminating this negative impact.

[0089] Release rate experiments showed that Example 1 had a release rate of only 12.5% ​​at pH 6.8, indicating that the supramolecular coordination network remained intact in a non-acidic environment, locking in the active ingredient. However, the release rate surged to 88.7% at pH 2.0, confirming the competitive disruptive effect of high-concentration hydrogen ions on the coordination bonds. This acid-opening, mid-locking characteristic ensures that the active ingredient can pass smoothly through the oral cavity and esophagus and be released concentratedly at the gizzard target site. In contrast, Comparative Examples 1 and 3 both exhibited rapid-release characteristics and failed to achieve targeted protection.

[0090] In animal experiments, the broiler serum GSH-Px activity in Example 1 group was the highest (184.2 U / mL), significantly superior to the blank group and all comparative groups. This was directly correlated with a reduction in muscle droplet water loss (2.15% vs. 4.67% in the blank group). Notably, the GSH-Px activity in Comparative Example 3 (containing inorganic zinc) (132.4 U / mL) was lower than that in Comparative Example 1 (145.7 U / mL), further confirming the potential pro-oxidative side effects of unpassivated metal ions in the digestive tract, which offset some of the antioxidant's efficacy. The present invention, through supramolecular assembly, successfully achieves a synergistic effect between zinc supplementation and antioxidant function.

Claims

1. An antioxidant feed additive composition, characterized in that, The system includes a ternary eutectic solvent active system adsorbed on a precipitated silica support. The ternary eutectic solvent active system is a homogeneous fluid formed by anhydrous betaine, α-lipoic acid and organozinc salt through a thermally induced in-situ coordination reaction at 75℃-85℃. The molar ratio of the components forming the ternary eutectic solvent active system is: anhydrous betaine : α-lipoic acid : zinc ions = (1.5) 2.5):1:(0.05 0.2); The mass ratio of the ternary eutectic solvent active system to the precipitated silica carrier is 1:(0.8). 1.5).

2. The antioxidant feed additive composition according to claim 1, characterized in that, The organic zinc salt is selected from one or both of zinc citrate or anhydrous zinc acetate.

3. The antioxidant feed additive composition according to claim 1, characterized in that, The molar ratio of the components forming the ternary eutectic solvent active system is: anhydrous betaine: α-lipoic acid: zinc ions = 2:1:0.

1.

4. The antioxidant feed additive composition according to claim 1, characterized in that, The precipitated silica carrier has an oil absorption value of 2.0-3.5 mL / g and a specific surface area of ​​150-200 m². 2 / g, with an average particle size of 10-20μm.

5. The antioxidant feed additive composition according to claim 1, characterized in that, The ternary eutectic solvent active system has an amorphous glass transition structure. In differential scanning calorimetry testing, the crystal melting peak of α-lipoic acid at 60°C disappears in the ternary eutectic solvent active system.

6. The antioxidant feed additive composition according to claim 1, characterized in that, The antioxidant feed additive composition is prepared by the following steps: Step S1: Mix the weighed anhydrous betaine, α-lipoic acid and organic zinc salt evenly to obtain a mixed powder; Step S2: The mixed powder is heated to 75°C-85°C under stirring and reacted at this temperature until the solid powder completely disappears, forming a clear and transparent ternary eutectic solvent fluid. Step S3: Maintain the temperature of the ternary eutectic solvent fluid at 65℃-70℃, and atomize and spray the ternary eutectic solvent fluid onto the fluidized precipitated silica carrier to obtain the adsorbed powder. Step S4: Cool the adsorbed powder to room temperature and allow it to stand and age for 12-24 hours under sealed conditions to obtain the antioxidant feed additive composition.

7. The antioxidant feed additive composition according to claim 6, characterized in that, The reaction time for step S2 is 40–60 minutes, and a nitrogen gas flow is introduced for protection during the reaction.

8. The antioxidant feed additive composition according to claim 6, characterized in that, In step S3, the inlet air temperature of the fluidized precipitated silica carrier is controlled at 25℃-35℃, so that the sprayed powder can be quickly cooled and cured.

9. The application of the antioxidant feed additive composition according to any one of claims 1-8 in broiler farming, characterized in that, Specifically, it is used in the preparation of feed to alleviate oxidative stress in broilers or improve the meat quality of broilers.

10. The application of the antioxidant feed additive composition according to claim 9 in broiler farming, characterized in that, The application includes mixing the antioxidant feed additive composition with a broiler basal diet and allowing the broilers to consume it freely.

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